Trialwise tracking method for measuring drug-affected sensory threshold changes in animals. Rats and rhesus monkeys were trained under a multiple schedule, the components of which were random ratio schedules for food presentation and for shock presentation. The discriminative stimulus for the shock presentation component was a pure tone for the rats and a light for the rhesus monkeys. In the test session under the extinction condition for the shock presentation component, the intensity of the discriminative stimulus was successively either decreased by fixed units when the conditioned suppression was observed or increased when the conditioned suppression was not observed. The levels finally oscillated within a narrow range around the threshold. The auditory thresholds of rats were increased by intramuscular administration of quinidine at 20 mg/kg and also by repeated intramuscular administration of kanamycin at 250 and 500 mg/kg/day. In rhesus monkeys, visual thresholds were raised by application of pilocarpine at 0.02-0.16 mg/kg to the eyes and also by subcutaneous administration of LSD-25 at 4-8 micrograms/kg in one monkey and at 20-30 micrograms/kg in another. The method used for tracking the animals' sensory thresholds was sensitive enough to test the selective effect of the drugs and was also a relatively easy way to obtain a stable behavioral baseline for experimental purposes.


Behavioral assessment of risk-taking and psychophysical functions in the baboon. Laboratory procedures have been developed for the experimental analysis of risk-taking and psychophysical functions in dog-faced baboons (Papio anubis). In a procedure analogous to the traffic light situation, animals are rewarded with food pellets for completing a fixed ratio of 100 responses in the presence of a green light. Superimposed upon this baseline performance are 5-second presentations of a yellow warning light terminated by a red light in the presence of which all responses are punished with electric shock. When the yellow light is introduced late in the sequence (e.g., after 93 responses have been completed), response rates increase and the 100-response ratio is completed before the 5-second yellow light times out. When the yellow light appears early in the sequence (e.g., after 73 responses) a marked decrease in response rate is observed with cessation of responding before onset of the red light. The sensitivity of components of this risk-taking performance to pharmacological toxicants is reported and psychophysical assessment of relevant sensory-motor effects described.


Operant conditioning of infant monkeys (Macaca fascicularis) for toxicity testing. A technique has been developed that allows infant monkeys to perform on an operant schedule as soon as they are able to self-feed. Behavior is shaped in small increments through a series of operants; sensory and motor systems as well as performance on schedules using intermittent reinforcement may be tested as early as 3-4 weeks of age. This is accomplished by exposing the infant to the operant situation almost continuously, and allowing the infant to feed only by operantly responding. Infants exposed to lead post-natally differed from controls in pattern of fixed ratio responding, "activity" as measured by pattern of responding over the course of the session, and on a two-choice form discrimination reversal learning set paradigm. This technique allows rapid accumulation of large amounts of data without experimenter intervention.


Effects of pre- and post-natal lead on affective behavior and learning in the rat. Literature relevant to the relationship between early ingestion of inorganic lead and subsequent hyperactivity in rodents is discussed. Original research in the area is presented. Rats so exposed were not hyperactive in any of the situations investigated or under any of the dosage regimens employed. They did show hypoactivity in the open field when dosed over a prolonged period. Using a new behavior measure, lead-treated rats were found to be less active than controls in the passive avoidance situation. The possible utility of this new measure for behavioral and developmental toxicology is discussed. It is concluded that the available evidence does not support the contention that a meaningful relationship exists between early lead ingestion and hyperactive behavior. It is suggested that future research may more profitably be directed to assessing the effects of lead ingestion on behavior in stressful or fear provoking situations.


Alcohol and the acoustic reflex: effects of stimulus spectrum, subject variability, and sex. Acoustic reflex thresholds were measured for eighteen young adults (9 men and 9 women) at four different blood alcohol levels: 0.00%, ascending 0.10%, 0.15% (peak level), and descending 0.10%. Reflex-eliciting stimuli consisted of three narrow-band noises (300 to 600, 600 to 1200, and 1200 to 2400 Hz) and three broad band noises (white noise, recorded rock music, and recorded factory noise). Prealcohol reflex thresholds were found to be significantly more sensitive than all postalcohol reflex thresholds for all stimuli, and broad-band stimuli demonstrated greater threshold shifts than did narrow-band stimuli. Significant sex differences were not observed for any blood alcohol level. Between subject variability was high, with 10 subjects showing little or no reflex threshold change and the other 8 subjects showing dramatic threshold changes.


Understanding continuity effects with complex stimuli. When a low-intensity stimulus A is alternated in time with a high-intensity stimulus B of relatively short duration, stimulus A is heard as continuous. This "continuity" effect is shown to occur even when the B stimulus is a series of sharp pulses at one rate and the A stimulus is a series of pulses at another rate which must produce a very different neural temporal pattern. Simple substitution models of the continuity effect are thus shown to be inadequate. A model is presented to make various types of continuity effects more understandable.


Consonant perception by normals in conditions of filtering. Consonant perception was investigated for 120 normal-hearing adults who listened to 16 consonants in a phrase context and made similarity judgements of 256 diadic stimulus pairs on a 9-point equal-appearing interval scale. Stimuli were presented at subjects' most comfortable listening levels in 3 low-pass filtered and one nonfiltered conditions. Subjects' ratings were converted to 16 X 16 full symmetric similarity matrices and submitted to INDSCAL analyses. Results revealed perceptual features common to all groups, as well as group-specific features (i.e., sibilancy, stop/continuancy, and place for nonfiltered; plosive and place for 4000-Hz low-pass; stop/continuancy and place for 2000-Hz low-pass; and voicing and stop/continuancy for 500-Hz low-pass). These results were similar to those found earlier for hearing-impaired subjects having sensorineural losses compatible with these frequency cut-offs.


Users' satisfaction with hearing aids.

Users' satisfaction with hearing aids. Seventy-one hearing aid users were surveyed two years after their initial fitting to determine whether they (1) wore the hearing aid(s) prescribed, (2) were satisfied with their aid(s), (3) had specific complaints about their aid(s), and (4) would recommend that a hearing-impaired friend or relative go through the same hearing aid selection process. Ninety-six percent of the respondents obtained that aid that we recommended. Eighty-eight percent were "very satisfied" or "satisfied" with the help that their aid(s) provided. Eighty-two percent would recommend that a hearing-impaired friend or relative go directly to a "hearing specialist" for assistance when selecting a hearing aid.


The influence of the guess factor on the speech reception threshold. Thirty normal hearing subjects were utilized in an investigation designed to determine the extent to which guessing on the part of the listener may influence the speech reception threshold. Results suggest that the magnitude of the speech reception threshold may be significantly altered as a result of the degree of guessing which occurs during the administration of the test. Clinical implications of this finding are discussed.


High-frequency consonant word discrimination lists in hearing aid evaluation. A summary of the results shows that with 5 of the 9 subjects the high-frequency consonant scores indicated the same aid for the patient that the NU-6 scores indicated. In 2 cases the NU-6 indicated amplification was appropriate whereas the high-frequency consonant scores indicated amplification was not appropriate. Obviously, the high-frequency consonant scores should be considered supplemental to the NU-6 scores and not as a replacement for the NU-6. The combination of the NU-6 and the high-frequency consonant results for Subject 1 may indicate that the patient should have received further counseling and should have been taught how to communicate more effectively without an aid. The high-frequency consonant scores obtained by 2 of the subjects indicated different aids than the ones indicated by the NU-6 test and the patient preference. Perhaps the reason the patient chose an aid other than the one that would most benefit him was that he was most comfortable with the aid that allowed him to hear in the manner to which he was accustomed, even if he did not do as well with it. If a person had become accustomed to not hearing the high-frequency sounds, an aid that suddenly allowed him to hear those sounds might disturb him. The addition of high-frequency amplification might have made speech sound foreign to him. It would have been much easier for him to choose the aid that he was most comfortable with.(ABSTRACT TRUNCATED AT 250 WORDS)


Developing service-based teaching in health education for medical students. In the expanding concern about the social-behavioral aspects of health care in medical education, health education has opportunities for making itself an important part of basic medical training. The need is to actually define a physician's appropriate educational tasks and competencies as a basis for curriculum development in health education which would ideally be integrated into the whole educational program. This case study presents efforts to develop an educational service component at a rural health center which, connected to a major teaching hospital, serves as a learning base for medical students. Through trial and student feedback a program has been developed which includes patient counseling, evaluative home visits, group education sessions, exit interviews, medication counseling, community needs assessment and educational consultation with local school teachers. With this program as a foundation, the goal is to integrate health education learning throughout the rest of the medical curriculum.


Progressive health education through community organization: a case study. Successful health education programs should be based on well-integrated community systems and networks. A health educator encountering community disintegration assumes a responsibility for taking a community organization effort. A case study of such an effort, based on Rothman's locality development model, is described. Community diagnosis and program development stages are detailed. Community health projects were among the outcomes attributed to this project.


Shaping the future of health education: from behavior change to social change. The view that individual behavior change is the primary goal of health education presents several serious problems. Although individual behavior does contribute to health and disease, social organization is perhaps a more powerful influence. The use of behavior change as the primary tool for health education raises grave ethical issues. Health education which seeks to change individual behavior has also failed to have a significant impact on public health. An alternative strategy is health education for social change. The goal of this approach is to involve people in collective action to create health promoting environments and life-styles. Several contemporary models for and principles characteristic of health education for social change are described.


Determinants of consumer influence in a health systems agency. An 18-month study of consumer participation and influence in a Health Systems Agency (HSA) found consumer board members to be less influential than provider board members in agency decision-making. In an effort to investigate causes of the influence deficit experienced by consumer HSA board members three issues were studied: staff attitudes toward consumer participation; board member degree of representative accountability; and board member attitudes concerning commitment to consumer participation, commitment to health planning, health services attitude, and feelings of social powerlessness. Results indicated that staff members were favorable toward the concept of consumer participation. They recognized a lack of low-income minority participation, but they did not provide support or allocate resources to enhance consumers' ability to participate. Providers were less committed to consumer participation, felt more socially powerful, and had greater representative accountability than did consumers. Several strategies for increasing consumer influence in HSA decision-making processes are proposed.


Construct validation of the health belief model. A multitrait-multimethod design was employed to assess the construct validity of the Health Belief Model. The data were obtained from a nonrepresentative sample of 85 graduate students at The University of Michigan's School of Public Health. The traits consisted of the respondents' perceptions of: health interest, locus of control, susceptibility to influenza, severity of influenza, benefits provided by a flu shot, and the barriers or costs associated with getting a flu shot. Each trait was measured by three methods: a seven-point Likert scale, a fixed-alternative multiple choice scale, and a vignette. The results indicate that the Health Belief Model variables can be measured with a substantial amount of convergent validity using Likert or multiple choice questionnaire items. With regard to discriminant validity, evidence suggests that subjects' perceptions of barriers and benefits are quite different from their perceptions of susceptibility and severity. Perceptions of susceptibility and severity are substantially but not entirely independent. Perceived benefits and barriers demonstrate a strong negative relationship which suggests the possibility that these two variables represent opposite ends of a single continuum and not separate health beliefs. These preliminary results provide the basis for developing brief health belief scales that may be administered to samples of consumers and providers to assess educational needs. Such needs assessment, in turn, could then be used to tailor messages and programs to meet the particular needs of a client group.


Reconstitution of cells by fusion of cell fragments. I. Myogenic expression after fusion of minicells from rat myoblasts (L6) with mouse fibroblast (A9) cytoplasm. Rat L6 myoblasts and mouse A9 fibroblasts (HGPRT-) were enucleated by centrifugation of monolayers in the presence of cytochalasin B. Intact cells were reconstituted by Sendai virus mediated fusion of nuclei (minicells) from enucleated rat myoblasts and cytoplasms from enucleated mouse fibroblasts. Colonies arising from proliferating reconstituted cells were distinguished from intact parental cell types on the basis of nuclear and cytoplasmic markers. In five replicate experiments, approx. 70% of all colonies found after fusion were derived from reconstituted cells, 30% arose from intact rat myoblasts contaminating the minicell preparations, and two colonies were identified as hybrids between the parental cell types. Clones derived from reconstituted cells formed myotubes which produced myosin and developed the cross-striated pattern typical of skeletal muscle. The myogenic program of the rat myoblast thus can persist through the enucleation and reconstitution procedures, and is not obviously altered by a period of exposure to mouse fibroblast cytoplasm.


DNA content of microcells prepared from rat kangaroo and mouse cells. Enucleation of animal cells in which nuclear fragmentation (micronucleation) has been induced by treatment with mitotic inhibitors results in the formation of subdiploid microcells consisting of one or several micronuclei, some cytoplasm and surrounded by a plasma membrane. Microcells were prepared from rat kangaroo cells (12 chromosomes) and a polyoma virus transformed mouse cell line (61 chromosomes) and analysed for DNA content. Microspectrophotometric DNA measurements and the appearance of micronuclei at mitosis show that small micronuclei contain genetic information equivalent to single chromosomes. A large proportion of the micronuclei and the microcells, however, contains DNA corresponding to several chromosomes. Heterogeneous mixtures of microcells can be fractionated by a unit gravity sedimentation procedure so as to isolate the small microcells. These can afterwards be fused with intact normal or mutant cells.


Cycloheximide-induced mitotic delay in Physarum polycephalum. Cycloheximide pulses applied to Physarum polycephalum surface plasmodia delay mitosis. Pulses applied in G2 cause a delay of mitosis which is linearly dependent on the phase in the cell cycle at which the pulse is applied. A 30 min pulse of 10 micrograms/ml cycloheximide starting in G2 at time t after mitosis induces an excess delay (delay in excess of pulse duration) of the next mitosis of (0.55) t-1.3 h. The excess delays induced by 7 h pulses during G2 are at most 1 h larger. Pulses applied less than 30 min before mitosis induce only small delays.


Acquisition of synchronous beating between embryonic heart cell aggregates and layers. Synchronous beating between chick embryonic heart cell aggregates and heart cell layers was used to study the relationship between intercellular adhesion and ionic coupling. Adhesion was measured by counting the proportion of aggregates which were not to be removed from cell layers by gentle washing after a 30 min incubation. Synchrony between bound aggregates and contiguous layers was assessed by phase microscopy. The first evidence of synchrony was seen 1.5 h after addition of aggregates to layers, following which there was an increase in the percentage of aggregates beating synchronously, reaching over 50% at 7 h and slowly increasing to a maximum of 65% by 24 h. Scanning electron microscopy and autoradiography of thymidine-labeled cells suggest that synchrony does not depend on cell movement at the interface between aggregate and layer. Acquisition of synchrony can be prevented completely by inhibiting protein synthesis, although pulsation of aggregates and layers continues in proportions unchanged from controls. After reversal of protein synthesis inhibition, synchrony is acquired at a rate and to an extent closely resembling that of newly adherent controls. These data indicate that ionic coupling is neither an inevitable nor an immediate consequence of adhesion. Since ionic coupling has been shown to correlate with the presence of gap junctions, the findings suggest that gap junctions are not involved in the initial events responsible for intercellular adhesion in vitro and that their formation following adhesion in this system may depend upon protein synthesis.


Morphological and functional correlates of synchronous beating between embryonic heart cell aggregates and layers. We have examined correlations between morphological and functional evidence of cell coupling between aggregates of beating embryonic heart cells and underlying layers. Synchronously beating aggregate-layer pairs were compared with asynchronous pairs. Intracellular microelectrode studies demonstrated that asynchronously beating aggregate-layers could not be induced to beat synchronously by electrical stimulation of the aggregate, whereas 86% of synchronous instances showed propagation of stimulating current pulses from aggregate to layer. By freeze fracture we have found significant differences both in the number and in the total area of gap junctions between the aggregate-layer interfaces of synchronous and asynchronous preparations. The data suggest that synchronous beating is a reliable functional indication of effective ionic coupling, and requires a certain area and number of gap junction/cell.


Specific modifications of hepatoma cell-surface glycoproteins with enzymes. Effects on in vitro growth as investigated by the use of lectins. The effects of enzymic treatment on the interactions between Zajdela's tumor cells and various lectins. Concanavalin A (ConA); Wheat Germ Agglutinin (WGA); Robinia lectin; have been studied. (1) The number of lectin-binding sites and the affinity constants were investigated. (2) The effects of the lectins on cell growth and [3H]thymidine incorporation were studied on untreated and enzyme-treated cells. It was observed that treatment of tumor cells with neuraminidase resulted in a change in the binding characteristics of each lectin. However, additional treatment of the cells with galactose oxidase had no further effect on lectin binding. ConA and Robinia lectin induced a decrease of the untreated tumor cell growth and a stimulation of the [3H]thymidine incorporation. This paradoxal result may be explained as a consequence of the stimulation of the [3H]thymidine uptake observed in the presence of lectins. The enzymatic treatments themselves did not change the cell growth although they did induce a change in the effect of ConA and Robinia lectin on cell growth and [3H]thymidine incorporation. As a result of neuraminidase treatment, the effects of ConA were totally suppressed but those of Robinia lectin only partially. Although WGA interacted with untreated and enzyme-treated cell surfaces, it had no effect on tumor cell growth nor [3H]thymidine incorporation. The results are discussed in terms of lectin transport.


The involvement of calcium in the activation of mammalian oocytes. Mouse oocytes with cumulus cells intact were parthenogenetically activated following release from the oviduct into calcium-free medium. The proportion of activated oocytes increased with post ovulatory age both for oocytes initially exposed to calcium-free and calcium-containing medium (control). Apart from oocytes released shortly after ovulation (approximately 1 h) when less than 1% of the oocytes from treated and control were activated, activation was always higher in oocytes incubated in calcium-free medium (p less than 0.001). The omission of magnesium from the medium had no effect on the activation response of oocytes obtained approximately 3 h after ovulation but its absence did increase the activation rate of oocytes of later post ovulatory age (approximately 9 h after ovulation) although it was still lower than that obtained with media devoid of calcium. When the extracellular calcium was replaced by other divalent cations (strontium, barium and manganese) high rates of activation were obtained even at post ovulatory times which produced relatively low rates of activation in calcium-free medium alone. Similar results were obtained when hamster oocytes were exposed to all the aforementioned treatments. It is concluded that calcium plays an essential role in the activation of the mammalian oocyte but the mechanism of its action remains obscure. Further development of oocytes activated by calcium-free treatment was limited and was similar to that of oocytes activated in other ways.


The effect of bromodeoxyuridine on the segregation of the chicken-specific HPRT gene from Chinese hamster-chick red blood cell somatic hybrids. The segregation of the chick-specific HPRT gene was studied in three Chinese hamster-chick red blood cell hybrid lines. The three lines showed individual segregation kinetics, the segregation taking place in an exponential-like fashion. Bromodeoxyuridine becomes incorporated into the nuclear DNA and increases the spontaneous segregation rate.


Quantitative initiation of microtubule assembly by chromosomes from Chinese hamster ovary cells. The microtubule nucleating capacity of chromosomes was tested in vitro in lysates of Chinese hamster ovary cells. Colcemid-blocked mitotic cells were lysed with the detergent Triton X-100, incubated with exogenous porcine brain tubulin, attached to electron microscope grids and observed as whole-mounts. Under suitable conditions, greater than 98% of the chromosomes gave rise to microtubules at their kinetochore regions, thus unequivocally demonstrating that chromosomes are competent to initiate specifically microtubule formation. The average number of microtubules that polymerized onto a chromosome was 8 +/- 5, and greater than 36% of the chromosomes had between 10 and 19 microtubules per kinetochore region. We conclude that under the lysis conditions employed, virtually all the chromosomes retain their kinetochores, and that the kinetochores retain a substantial fraction of their microtubule nucleating capacity.


DNA repair in UV-irradiated heteroploid cells at different phases of the cell cycle. The variation of DNA repair activity during the cell cycle was studied by analysing the UV-stimulated DNA synthesis in cells synchronized in mitosis. This activity was detected both by autoradiography and by directly measuring the incorporation of tritiated thymidine in cells irradiated and incubated in the presence of hydroxyurea. Cells in all phases were found to be able to perform repair. However the activity appeared to be considerably lower in mitotic cells than in cell in other phases. Increasing values of repair capacity were observed in G1 cells, in mixed G2, S and M cells and in asynchronous cells. The relationship between these findings and data on survival rates in the same synchronized cells is discussed.


Normal level of unscheduled DNA synthesis in Werner's syndrome fibroblasts in culture. We investigated UV-induced unscheduled DNA synthesis (UDS) in skin fibroblasts from seven unrelated patients with clinically apparent Werner's syndrome (WS). WS cells exhibited greatly abbreviated in vitro lifespans, the extents of which ranged from about 20 to 50% of the normal. However, WS cells in early and senescent phases of growth showed the same quantity of DNA repair following UV exposure as did normal fibroblasts.


Increased phosphorylation of a specific protein in mitogen-stimulated lymphocytes. The phosphorylation of proteins from murine splenic lymphocytes was studied. When the phosphorylation of proteins in extracts from Concanavalin A (ConA)-treated lymphocytes was compared with that of resting lymphocytes, there was only one detectable difference between them. A protein of 135,000 mol. wt was highly phosphorylatable in extracts from ConA-treated cells while phosphate incorporation into this protein was slight in extracts from untreated cells. This effect could be observed 12 h after ConA treatment and was maximal during S phase. This soluble protein was also phosphorylated in intact lymphocytes.


Alterations in iodinated cell surface proteins during myogenesis. Lactoperoxidase catalysed iodination was used to label surface proteins of chick embryo muscle cells during myogenesis. Both quantitative and qualitative changes were observed between 125I-labelled surface proteins of pre-fusion, mid-fusion, and post-fusion cells. Significantly, two bands at 245,000 molecular weight were present at pre-fusion but were observed as a single band at mid- and post-fusion. Radioactivity in this band increased selectively at post-fusion with a concomitant increase in lower molecular weight labelled proteins.


Are double minutes chromosomes?

Are double minutes chromosomes? Double minutes of a human breast cancer cell line revealed no centromeres by Cd banding. They cluster at the periphery of metaphase plates, usually encased in a matrix material. They move in anaphase passively with the chromosomes by attaching to the sides or ends of the chromosomes. The two "sister minutes" move to the same pole without separation. Such anomalous mitotic behavior suggests that double minutes are not chromosomes.


Premature fusion of facial sutures with free periosteal grafts. An experimental study with special reference to bone formation with free periosteal grafts from the tibia, the scapula and the calvarium. The present study was undertaken to obtain more information on the bone forming mechanisms with free periosteal grafts and to study premature synostosis of facial sutures achieved with free periosteal grafts. The results are based on a material of 196 rabbits operated on at the age of two weeks. It was found that the bone forming mechanism with free periosteal grafts from the tibia, the scapula and the calvarium is essentially the same. When implanted in the tibialis anterior muscle of the leg of the same animal they all produced bone. The mechanism of bone formation is reminiscent of the enchondral bone formation seen in fracture healing. There is no difference in the bone forming mechanism with the periosteum from an enchondrally ossifying bone when compared with the periosteum of an intramembranously ossifying bone. In all the three different periosteal grafts studied, there was a cartilage stage before bone formation. In the muscle, all these three periosteal grafts, in spite of their tubular or membranous bone origin, produced bones tubular in shape. When the transplants were overlying the membranaceous facial bones, membrane shaped bone developed via intramembraneceous type of ossification in the recipient area. It can be concluded from these experiments that the shape and type of bone developed with free periosteal grafts depends mainly on the environmental conditions in the recipient area. Fusion of the premaxillo-maxillary and fronto-nasal sutures was achieved with free periosteal grafts from the tibia. Free periosteal grafts from the scapula and the calvarium failed to develop premature fusion of the sutures. The fusion developed due to increased bone formation in the suture area. The fusion of the premaxillo-maxillary suture stopped the growth in this area and caused a severe growth disturbance of the whole snout. The fusion of the fronto-nasal suture by the bone bridge retarded the growth of the nasal bone on the fused side and led to deviation of the snout to the operated side. Compensatory changes developed in other sites of the cranio-facial skeleton in order to minimize the effects of the growth disturbance. The fused fronto-nasal suture was used as a model to study the treatment of premature synostosis of facial bones. Resection of the fused area led to correction of the developed growth disturbance and to subsequent normal growth of the snout.


Technique of cervical myelography with metrizamide. A technically simple modification of the prone posture technique for cervical myelography with use of metrizamide (Amipaque) after lumbar puncture is described. The procedure is well tolerated by the patients.


Cervical myelography with metrizamide.

Cervical myelography with metrizamide. In 177 patients 190 cervical myelographies were performed, 52 after cervical and 138 after lumbar puncture. While the last-mentioned technique may be considered as the safest, the first-mentioned appears to cause less adverse reactions and also offers films of higher quality. The cooperative ability of the patient as well as the shape of the spine must be considered for selecting the site of puncture. Films are obtained permitting high diagnostic accuracy with regard to lesions involving root sleeves and to the presence of intramedullary or extramedullary lesions, in particular protrusions and disc herniations.


Cervical myelography with metrizamide by suboccipital puncture. Cervical myelography with metrizamide (Amipaque) by suboccipital puncture was performed in 125 patients. Side effects were insignificant and there was no discomfort for the patient. The maximum amount to be injected is 3.75 g metrizamide (1.5 g iodine), and care must be taken in order to keep the contrast medium out of the basal cisterns. No premedication was used and no signs of irritation of the central nervous system were observed. With this technique the spinal cord and the nerve-roots are well demonstrated.


Metrizamide in selective cervical myelography. The various techniques of cervical myelography are discussed and a technique is described to examine the cervical region after lumbar injection of the contrast medium. This technique is considered less hazardous than other techniques including application of the contrast medium by direct puncture in the cervical region and is advocated for use in patients who have free circulation of CSF and who do not have marked deformity or marked rigidity of the spine.


Myelography with metrizamide in intraspinal and spinal abnormalities. Myelography with gas or iophendylate is difficult in patients with spinal anomalies. Metrizamide (Amipaque) has been used to evaluate 20 patients with Chiari malformations, achondroplasia, and conditions related to scoliosis. Lateral cervical puncture was uncomplicated in 10 patients with Chiari malformations. Definition of spinal subarachnoid space was adequate to demonstrate or exclude associated intraspinal tumors or diastematomyelia.


Cervical myelography with metrizamide using lumbar injection. The technique, the quality of the films and the frequency of side effects are evaluated in 100 consecutive cervical myelographies with lumbar injection of metrizamide (Amipaque). The most frequent adverse effects were headache (47%) and nausea and vomiting (27%). EEG disturbances were recorded in 20 per cent. Due to special circumstances grand mal seizures and mental confusion occurred in one patient; this was the only major complication in altogether 260 cervical myelographies with lumbar injection.


Cervical myelography by lateral cervical and lumbar injection of metrizamide. A comparison. Two methods of cervical myelography, C1-C2 and lumbar injection of the contrast medium, respectively, were carried out in 2 series of patients. The C1-C2 injection resulted in films of higher quality than the lumbar injection but is probably more risky. It was unsuccessful in approximately 5 per cent of the patients. If only patients suited for the lumbar approach are examined with lumbar injection and the others with C1-C2 injection, films of high quality are obtained in almost all patients and a low frequency of adverse effects is encountered.


Cervical myelography using metrizamide and lateral C1-C2 approach. Excellent results in cervical myelography are obtained using metrizamide (Amipaque) introduced at lateral C1-C2 approach. With this technique, intraspinal anatomic structures are clearly outlined and small lesions easily detected.


Lumbar myelography.

Lumbar myelography. The total material of lumbar myelographies performed with metrizamide (Amipaque) up to November 1976 (48,000 examinations) has been reviewed to assess the incidence of side-effects. A detailed analysis of 2,457 examinations from Ullevål Sykehus has been performed in order to assess adverse effects and diagnostic reliability. Three epileptic seizures were recorded, two of these in known epileptics. The rate of minor side-effects was low and the diagnostic accuracy high.


Myelography with metrizamide in infants and children. Myelography with metrizamide (Amipaque) was performed in 46 infants and children. The contrast medium was rated as excellent. The examinations demonstrated more anatomic detail than is available from either myelography with oily contrast media or gas alone. The adverse reactions were at acceptable clinical levels.


Pediatric myelography with metrizamide.

Pediatric myelography with metrizamide. Ninety-four children were examined with metrizamide (Amipaque). Overall, the quality of the examinations in the lumbar-low thoracic region was generally equivalent to that obtained with iophendylate. Supine myelography is unfortunately still a necessity in a large number of cases. The side effects, especially nausea and vomiting, slight temperature elevation and fever, are considerably higher with metrizamide and also higher than previously reported in adults. Advantages of metrizamide over oily media are the absorption of the medium which eliminates the need for post-procedure removal and the higher rate of conus demonstration in the prone position; both facilitate the examination. The ability to follow myelography with computer scanning is also beneficial.


Myelography with metrizamide in infants and children. Technical aspects on myelography in pediatric patients with the water-soluble contrast medium metrizamide (Amipaque) are reviewed. Special interest is paid to site of puncture, positioning of the patients and concentration and dosage of the medium.


Myelography with metrizamide in children. Thirty myelographies with metrizamide (Amipaque) were carried out in 25 children with only few and minor adverse effects. The doses of the contrast medium used were considerably higher than adult doses if compared to body weight, but smaller in comparison to brain weight. Concentrations of 170 to 250 mg I/ml were used.


Cisternography with metrizamide of the posterior fossa following lateral C1-C2 puncture. A report is given of a series of 23 consecutive cisternographies with metrizamide (Amipaque) of the posterior fossa using the lateral puncture at the C1-C2 level. Two to 4 ml metrizamide 300 mg I/ml were injected. The good clinical tolerance with regard to short as well as long-term effects of the contrast medium may be attributed to the low dose used and rendered possible by the selective distribution. No clinical epileptogenic seizures were observed.


Computer cisternography for evaluation of CSF flow dynamics. Further experiences. Technical aspects of computer cisternography are discussed and the clinical results obtained are reported. The physiologic and morphologic information gained with computer cisternography is superior to that obtained with isotope cisternography. Some recent observations concerning the penetration of the medium into the central nervous system are also discussed.


Metrizamide brain penetrance.

Metrizamide brain penetrance. The normal cerebrospinal fluid flow as monitored by serial CT cisternography with metrizamide (Amipaque) is described in 25 individuals. Preliminary gross autoradiography using 131I-labelled metrizamide concur with these CT cisternographic findings indicating that intrathecally introduced metrizamide penetrates the brain substance. Adverse reactions are most prominent during the periods of maximum brain penetration and include headache, nausea, perceptual aberrations, and EEG alterations. The value and diagnostic applications of cerebral and cerebellar penetration of metrizamide are also discussed.


Computer tomography in cisternography with metrizamide. The preliminary results with computer tomography in cisternography with metrizamide (Amipaque) indicates that both normal and abnormal cerebrospinal fluid dynamics can be accurately displayed with the advantage of spatial and quantitative detail. The pharmacokinetics of metrizamide clearance from cerebrospinal fluid to blood are similar to those of nuclides. Hence, similar problems in predicting response to ventricular shunting may arise. However, the quantitative features of this method have yet to be fully exploited.


Computer tomography of the spinal canal using metrizamide. Eleven patients have been examined by whole body CT employing the EMI CT 5000 following lumbar injection of 10 ml of metrizamide (Amipaque) 170 mg I/ml. The distribution, flow and dilution of the contrast medium have been investigated. The results suggest that whilst metrizamide is necessary in the spinal canal to demonstrate the neural axis and pathologic processes affecting it, it appears to enter the extracellular space of the spinal cord during the first hour and achieves an equilibrium in the subarachnoid space and spinal cord from 3 to 6 hours. The medium may concentrate in a second compartment, possibly intracellular, from 3 to 6 hours. The effect of spectral filtering by metrizamide on the attenuation values of the spinal cord has been modelled and shown not to be significant at the anticipated dilution of the medium in the cerebrospinal fluid space and the spinal canal.


Metrizamide enhancement of cerebrospinal fluid for computer tomography. Enhancement of CT attenuation values of the CSF cisterns by the lumbar injection of metrizamide has been shown to be of value in demonstrating the anatomy of the cisterns. Tumors involving the cisterns, such as acoustic neurinomas and pituitary adenomas, are clearly defined. Coronal scanning was superior to horizontal views in many cases.


Technique of lumbar myelography with metrizamide. It is not possible to change from oily to aqueous contrast media for myelography without modifying the entire technique. The advantages of myelography with metrizamide (Amipaque) are so great in terms of improved diagnostic accuracy, no withdrawal of contrast medium and reduced incidence of arachnoiditis that it is firmly believed that this technique will soon replace oily myelography as standard practice, at least for the lumbar and thoracic regions.


Cisternography with metrizamide and hypocycloidal tomography. Cisternography with metrizamide (Amipaque) and hypocycloidal tomography was found to depict cisternal anatomy with detail and precision not obtainable with any other technique. Clinical tolerance is comparable to that of encephalography if suitable precautions are followed. All side effects observed had disappeared 36 hours after injection, and no delayed noxious effects were recorded. This method offers a simple, rapid and precise technique for depicting cisternal anatomy and requires no equipment other than a tilting multidirectional tomographic unit.


CT cisternography with metrizamide.

CT cisternography with metrizamide. Intrathecally enhanced CT scans were performed in 103 patients with potential morphologic or physiologic (CSF) abnormalities. This examination called CT cisternography with metrizamide (Amipaque) proved of high value in demonstrating and characterizing basal mass lesions and CSF related physiologic disorders using low dose techniques. This examination merits inclusion in the standard neuro-diagnostic armamentarium when information is required beyond that of intravenously enhanced CT for localizing and characterizing subarachnoid related morphologic or physiologic processes.


Computer tomography and subarachnoid metrizamide for evaluation of cerebrospinal fluid flow. Twenty-one patients were examined with computer tomography following subarachnoid injection of metrizamide (Amipaque). Five were evaluated because of dementia or possible obstructive hydrocephalus. The remainder were referred for lumbar or cervical myelography and served as controls. Concentration and distribution of the contrast medium within the cranial subarachnoid space and ventricular system depend upon a composite of the physical properties of the contrast medium, patient positioning and activity and CSF physiology.


Transient areflexia following thoraco-lumbar myelography with metrizamide. Report of a case. In a 32-year-old female areflexia occurred after thoraco-lumbar myelography with metrizamide (Amipaque), instead of the hyperreflexia usually found as a side effect of subarachnoid water-soluble contrast media. A direct neurotoxic effect on the cauda equina seems to have been the cause.


Arachnoiditis following myelography with metrizamide in monkeys. Effect of blood in the cerebrospinal fluid. Monkeys were injected intrathecally with blood, metrizamide (Amipaque) or a mixture of blood and metrizamide. Twelve weeks later the animals were examined for evidence of arachnoiditis. Either blood or metrizamide alone in sufficient amounts resulted in arachnoiditis. The addition of blood to metrizamide did not alter the severity or risk of arachnoiditis from experimental myelography with metrizamide.


Lumbar myelography with metrizamide.

Lumbar myelography with metrizamide. Experiences with lumbar myelography with metrizamide (Amipaque) are reported. A less strict post-examination routine is presented. The subjective side effects do not seem to differ from those reported after lumbar puncture alone.


Possible causes of complications of myelography with water-soluble contrast medium. The mechanisms of CSF formation and absorption have been reviewed. The conditions that alter the rate of CSF formation and absorption may change the concentration of contrast in the cranial cisterns and the rate of passage through the cisterns. The significance of these alterations in relation to the complications of myelography with water-soluble contrast media is discussed.


Mental confusion and epileptic seizures following cervical myelography with metrizamide. Report of a case. A case of alarming, but transient clinical and EEG disturbances following cervical myelography with metrizamide (Amipaque) is reported. Clinically, mental disturbances and epileptic seizures were prominent, while bilateral rhythmic slow waves and spikes occurred in the EEG recordings.


Functional myelography with metrizamide in the diagnosis of lumbar spinal stenosis. Metrizamide (Amipaque) as a contrast medium for functional lumbar myelography was evaluated in 63 patients. It was found well suited, the adverse effects being insignificant. Good correlation was found between the clinical and the myelographic diagnosis. An a.p. diameter in extension of less than 8 to 10 mm (true value 5.5-7.0 mm) was found only in patients with considerable complaints and in whom operation was indicated.


Thoracic myelography with metrizamide. Technical and diagnostic aspects. A series of 161 thoracic myelographies with metrizamide (Amipaque) in 154 patients is reported. The examinations were easy to carry out with an ordinary general fluoroscopic tilting table. The dose most frequently used was 12 to 14 ml with an iodine concentration of 200 mg I/ml. Intraspinal neoplasms were found in 42 and other expanding lesions in 10 patients. No serious complications occurred.


Thoracic myelography with metrizamide.

Thoracic myelography with metrizamide. In 124 patients 141 thoracic myelographies were performed with metrizamide (Amipaque). This contrast medium penetrates narrow spaces more easily than gas and oily media. The technique and the positioning of the patient should be adapted to the region clinically suggested in order to obtain best results.


Thoracic myelography with metrizamide.

Thoracic myelography with metrizamide. A description is given of the technique used in thoracic myelography with metrizamide (Amipaque). Analysis of 60 cases demonstrates the results that were obtained.


Myelography with metrizamide in the cervical region. Cervical myelography with metrizamide (Amipaque) was performed in 72 instances by lateral cervical puncture between C1 and C2, and in 21 instances by lumbar injection. A slight but significant difference in adverse reactions following the two methods was found. On comparing lumbar and cervical myelography using the lumbar approach a significantly higher incidence of nausea and vomiting following the cervical examination was demonstrated. No serious reactions occurred after either the lumbar or the cervical approach.


The neuroanatomy of eating and drinking behavior. For a number of years, the hypothalamus has been assigned the central and virtually exclusive role in regulating eating and drinking behavior. Now this concept is being challenged by new experimental evidence showing that ingestive as well as other behaviors are profoundly influenced by several neural tracts, particularly the neuroamine pathways, that may pass through the hypothalamus.


Coordinate transcription within families of related DNA sequences in human colon and rat liver. An assay has been developed to determine the fraction of members of active families of related base sequences which are being transcribed into RNA. In normal human colon mucosa and in normal rat liver, essentially all members of the active families are being transcribed.


Histone synthesis by cleavage arrested sea urchin eggs. A change in Hl histone synthesis occurs in blastulae, from Hlm to a faster moving Hlg in acrylamide gel electrophoresis. The experiments below indicate that this shift occurs in the absence of normal cleavage. Hybrid embryos containing paternal Hl histone markers along with homospermic embryos were studied. Both were labeled with L-[3H]lysine. Some cultures were kept at 11 degrees C to inhibit cleavage. It was found that Hlm and Hlg are synthesized sequentially in time by embryos grown at 20 degreet C as well as by those grown at 11 degrees C. The hybrid data establish that Hlm is translated at least in part from mRNA newly transcribed from paternal DNA. This observation also holds for cleavage inhibited hybrid embryos. Hlg is made by both hybrid and homospermic embryos during the later phases of development at both 11 and 20 degrees C. These results confirm and extend those of Seale et al. (1973), Ruderman et al. (1974) and Easton et al. (1974).


Reactivation of nuclei containing lens fiber cells to mitotic growth biochemical and immunochemical analysis. Nuclei containing lens fiber cells can be reactivated to mitotic growth by transplantation into a suitable culture medium. Reactivated epithelium-like fiber cells are morphologically indistinguishable from cultivated epithelial cells. During reactivation the enzyme pattern of the differentiated fiber cells changes to a pattern closely related to that of cultivated epithelial cells. Moreover dedifferentiation was correlated with an appreciable loss of specific lens proteins (alpha-crystallin). Cytoplasmic shedding and attachment of fiber cells to the substratum are discussed with regard to their role in the reactivation process.


Isolation and properties of DMSO resistant variant clones of Friend leukemia cells. DMSO resistant clones have been isolated from the inducible Friend leukemia cell line 5-86 both from unmutagenized cultures and following EMS mutagenesis. All the clones can grow in the presence of 1.8% DMSO and are non-inducible or poorly inducible for hemoglobin synthesis by DMSO as well as by other known inducers of Friend leukemia (FL) cells differentiation like hemin, hypoxanthine, hexamethylene bisacetamide. The clones are also defective for the expression of other properties of differentiating Friend cells like agglutinability by plant lectins and expression of the surface protein glycophorin. Some of the clones show an impaired ability to form tumors in vivo. These resistant clones might be useful for a genetic analysis of the differentiation process of Friend leukemia cells.


Exogastrulation induced by heavy water in sea urchin larvae. Replacement of H2O with D2O in seawater causes exogastrulation in larvae of the sea urchins, Hemicentrotus pulcherrimus, Strongylocentrotus intermedius and S. nudus. When larvae at any stages before mesenchymal blastula stage are transferred to 40% D2O-seawater all of them develop gradually to exogastrulae and finally up to plutei with evaginated archenterons. Effects of D2O are partly reversible at limited steps of the way to exogastrulation. Fertilisation and cleavage are not affected appreciably by D2O (50% or less) except for the delay of cleavage.


Lateral roentgenography in the diagnosis and treatment of dysplasia/dislocation of the hip. The author emphasizes the importance of true lateral and multiple-position roentgenograms in providing a more comprehensive demonstration of the pathology, the attainment of reduction and the surgical alterations which are necessary to maintain a congruous reduction. A simple convenient technique for lateral roentgenography of the hip in children is presented. A series of cases with roentgenograms is also presented to demonstrate the value of the lateral roentgenograms. The horizontal lateral roentgenogram simulates the position of the upright human stance, and thus, depicts malocclusion, which may be seen when anteversion is present. Even though the anterior view depicts sphericity and apparent coverage, the lateral roentgenogram may show malocclusion which may lead to degenerative changes later in life. It is the author's belief that the treatment of children's hip conditions will show improved long-term results if predicated on the comprehensive x-ray examination outlined in this article.


Dihydroretinoic acids and their derivatives. Synthesis and biological activity. The syntheses of the ring and four side-chain dihydroretinoic acids and/or their esters, 3-7, are described. The syntheses of several other retinoids containing a substituted aromatic ring are also included. The biological activity of the compounds was evaluated in vivo in a chemically induced mouse skin papilloma test and in vitro in two vitamin A deficient assays. The activity observed for 1a, 1c, and 2a in the former test was partially retained in the dihydro derivatives 4b, 4c, and 6b. Similar results were found in the in vitro assays.


Dose-dependent cytokinetic changes following 1-beta-D-arabinofuranosylcytosine and hydroxyurea in L1210 and S-180 in vivo. DNA synthesis inhibition and recovery in L1210 and S-180 ascites tumors following 1-beta-D-arabinofuranosylcytosine (Ara-C) and hydroxyurea (HU) were measured autoradiographically as a basis for optimizing drug schedules. Tumor bearing mice, 10(6) cells day 0, were treated on day 4 with 20, 200 or 2000 mg/kg Ara-C or 50, 300 or 1800 mg/kg HU. At various intervals following drug, [3H]thymidine was administered i.p. and mice were killed 1 hr later. Tumor cells were analyzed for labeling index (LI) and grain count (GC) to determine the percentage of cells in S phase and the distribution of DNA synthesis rates among the labeled cells, respectively. Following each dose of HU, DNA synthesis was inhibited completely. Recovery of LI was rapid and approached control values by 6 hr. Following each dose of Ara-C, DNA synthesis was inhibited completely for at least 6 hr. Recovery of LI was first noted 6 hr following 20 mg/kg Ara-C and 9 hr following 200 mg/kg. Following both doses the LI reached 100% of the control value by 26 hr. GC analysis indicated that following Ara-C treatment, DNA synthesis was reinitiated first with cells with low GC from 6 to 12 hr followed by cells with increasing GC from 12 to 20 hr. The labeling intensity reached control values by 20 hr and an 'overshoot' occurred by 26 hr. These data suggest that the recovery of DNA synthesis rate is a gradual process. Survival data for mice receiving two doses of Ara-C indicated that the optimal interval for retreatment following the lower dose of Ara-C occurred by 6 hr as compared to 12--16 hr for the higher dose. These times coincided in both instances with recovery of LI to 33--50% of control values. Early recovery of LI may be the best method currently available for estimating the optimal time for retreatment with an S phase specific drug.


Inhalative provocation test. When is it positive? A range for the airway resistance (R), reference resistance (Rref), quotient (R/Rref) measured by whole body plethysmography is given for unspecific inhalative provocation in asthmatic patients. 1. In patients with an initial R/Rref value less than 2 (R about 0,6 kPa/l/s) the non allergic reaction did not exceed an R/Rref quotient of 2,7. 2. Those patients with an initial R/Rref quotient greater than 2 but less than 5 reached an R/Rref value of 8.5 after non allergic provocation, which equals an R of about 1,75 kPa/l/s. It is recommended to provoke only those patients in whom the initial R/Rref quotient is in the beginning smaller than 2; because it is otherwise difficult to separate allergic from non allergic reactions and the necessary allergen induced bronchospasm might be harmful. Reference values for specific airway resistance have the advantage that we do not need a panting manouvre against a closed shutter which is often difficult to achieve especially with children during an asthmatic attack.


The relationship of patient selection to prognosis following aortocoronary bypass. Operative mortality for the first 787 patients who underwent aortocoronary bypass at Duke University Medical Center was 9.7%. Within 699 patients who underwent elective bypass only, operative mortality was 8.8% before January 1, 1972, and 5.4% subsequently. This apparent variation in operative mortality over time was largely a consequence of changing patterns of patient selection, i.e., a two- to three-fold decrease in the prevalence of ventricular dysfunction. Since January 1, 1972, operative mortality for 444 patients with mild or no heart failure who underwent elective bypass only was 5.0%. The 55 patients with left main disease had 12.7% operative mortality. In the 192 patients without left main disease who had one- or two-vessel disease, operative mortality was 1.0%, whereas, 197 patients with three-vessel disease had a 6.6% operative mortality. The 103 patients with three-vessel disease less than 50 years of age underwent operation with a 2.9% mortality. Although these results demonstrate that selected patients may undergo operation with a mortality approaching 1%, it is not clear that only such low risk patients should be offered surgery. Accurate estimates of benefits and risks of aortocoronary bypass surgery are necessary in the management of specific patients.


Accelerated "atherosclerosis". A morphologic study of 97 saphenous vein coronary artery bypass grafts. Intimal thickening of uncertain cause has been noted in saphenous vein bypass grafts. To study the development of these changes, 97 vein grafts in 55 autopsied patients were examined by angiography and histology. Significant alterations in the grafts were confined to the intima and included thin layers of circumferential thrombus, concentric fibrous plaque and occlusive thrombus with organization. Circumferential nonocclusive intimal thrombus was present in 36 (73%) postoperative patent grafts. Concentric fibrous plaque, found in all twelve patent late grafts, showed changes characteristic of atheromata, including smooth muscle and foam cells. Intimal fibroelastosis was absent in the grafts, indicating that concentric plaque is not a simple response to increased pressure, or an "arterialization" of the vein. The findings suggest that early appearing concentric intimal thrombus is converted into fibrous plaque, and that this early thrombus is a factor in the development of acclereated "atherosclerosis" in saphenous vein bypass grafts.


Aortic valve replacement combined with myocardial revascularization. Late clinical results and survival of surgically-treated aortic valve patients with and without coronary artery disease. From 1967 through 1973, 80 consecutive patients underwent simultaneous aortic valve replacement (AVR) and coronary bypass grafting. Fourteen (18%) experienced no angina pectoris and had no history or electrocardiographic evidence of coronary atherosclerosis. Seven of these 14 had severe multiple vessel disease. All operations were performed under normothermic conditions without coronary perfusion. Seven patients (9%) died during operation. Intra-operative myocardial infarction was documented in eight (10%). After a mean follow-up of 35 months, overall mortality was highest in aortic regurgitation patients [seven of 13 (54%)] compared to aortic stenosis [17 of 54 (31%)] (P less than 0.07), and mixed pathology [1 of 13 (8%)]. Thirty-one of 34 (91%) grafts in 25 patients were patent an average of 12 months postoperatively. After 42 months a 65% actuarial survival was found in the combined AVR and graft(s) series versus a 76% survival in 300 AVR patients proven by angiography not to have severe coronary atherosclerosis.


Histocompatibility antigens in chronic liver disease. The frequencies of histocompatibility antigens (HL-A) have been determined in patients with chronic active hepatitis, cryptogenic cirrhosis, and alcoholic cirrhosis, and were compared with those in a control group of 900 healthy subjects. No significant differences were found and the previously reported increased frequency of HL-A8 in chronic active hepatitis has not been confirmed. The discrepancy from some previous reports could not be explained by different histological, immunological, or biochemical features. However, in view of the variation in incidence of a number of features of the disease from series to series, it seems possible that our findings may reflect differences in the selection of patients or real differences in the disease entity seen by different workers.


Intestinal absorption of 47Ca in elderly patients with osteoporosis, Paget's disease and osteomalacia. Effects of calcitonin, oestrogen and vitamin D2. The intestinal absorption of 47Ca was studied in elderly patients. A standard dose of 10 muCi of 47Ca was given orally. The radioactivity was measured in the plasma, and expressed as percentage of the administered dose per litre plasma. As a control group served 12 patients aged 60-80 years, hospitalized for observation for various reasons, receiving no medical treatment and not suffering from any known metabolic bone diseases or other metabolic pathological conditions. Results of kinetic curves demonstrate in elderly patients a decreased absorption with maximum specific activity in plasma reached at 120 min, when compared to data from the literature referring to a group of young people with a mean age of 35 years. Oestrogen treatment, given as ethinyl oestradiol 10 mug once daily per os for 10 days proved to increase 47Ca absorption as was demonstrated in 2 patients with osteoporosis. The effect of calcitonin (160 MRC units given 45 min before the test) on calcium absorption, in 5 patients with Paget's disease or osteoporosis appears as biphasic: in the first hour depressing calcium absorption and then in the second and third hours increasing the absorption, suggesting a hyperparathyroid state secondary to the calcitonin effect. The vitamin D2 treatment proved to increase calcium absorption.


Hairy cell leukemia: B-lymphocyte and phagocytic properties. The diagnosis of hairy cell leukemia was made in three patients by phase-contrast microscopy and histochemistry of the abnormal peripheral blood cells. Both IgM and IgD surface immunoglobulins were resynthesized after these cells were trypsinized and cultured. Aggregate or Fc receptors were demonstrated on hairy cells. The ability to phagocytose latex was also a property of hairy cells; however, these cells did not demonstrate nonspecific esterase activity. Stimulation by phytohemagglutinin resulted in very low incorporation of tritiated thymidine. Cytofluorographic analysis of the phytohemagglutinin-stimulated cell population revealed less than 9% of the cells in an interploid or tetraploid state. The abnormal mitogen response was largely restored when purified T lymphocytes obtained from the peripheral blood of the patients were cultured with phytohemagglutinin. Hairy cells cultured with normal allogeneic mononuclear cells did not undergo blast transformation. These data strongly suggest that the cells of at least some patients with hairy cell leukemia are B lymphocytes with phagocytic capabilities.


Cytofluorometric analysis of the kinetics of lymphocyte transformation after phytohemagglutinin stimulation: comparison with the kinetics of thymidine incorporation. The technique of flow cytofluorometry has been employed to assess the response of unfractionated and highly purified human lymphocyte subpopulations to phytohemagglutinin (PHA) and pokeweed mitogen. Normal values for cytofluorometric responses were established and compared to the uptake of tritiated thymidine in simultaneous experiments. Cytofluorometric analysis offered the advantages of increased sensitivity and direct measurement of DNA content per cell, and provided percentages and absolute numbers of responding cells. B-cell responses to pokeweed mitogen were absent, but brisk T-cell responses were noted. Between 4% and 8% of highly purified human B cells were found to respond to PHA by increasing their DNA content; modest but significant uptake of tritiated thymidine by B cells following PHA stimulation was also observed.


Changes in hemopoiesis during the course of acute LCM virus infection in mice. Although severe hematologic and immunologic disorders occur in several viral infections, insight into the mechanisms by which viruses may affect hemopoietic tissues is poor. The previous demonstration of distinct immunohemopoietic lesions in mice with acute lymphocytic choriomeningitis (LCM) virus infection has led us to investigate the function of hemopoietic precursor cells in the course of this experimental infection. During the first week of infection, there was profound suppression of pluripotential stem cell (CFU) and in vitro colony-forming cell (CFU) compartments, and of 59Fe uptake into hemopoietic tissues. During the same period, we found enhanced activity of colony-stimulating factor, lack of responsiveness to erythropoietin, and appreciable titers of interferon in blood and spleen. After day 10 post infection, there was a striking increase in CFU and 59Fe uptake confined to spleen and blood. Restoration of bone marrow, however, was markedly delayed. With reference to recent studies on interferon, and the findings in mice with persistent LCM virus infection, we suggest that interferon may be the comprehensive suppressor of the hemopoietic precursor cells in the first stage of acute LCM virus infection, and that these cells in the recovery period are directed preferentially into erythropoiesis.


Successful correction of all mechanical complications of ischemic heart disease in the same patient. Extensive surgery for all of the mechanical complications of ischemic heart disease is feasible with early diagnosis, catheterization, and aggressive medical and surgical therapy. A patient is report who, after recovering from cardiogenic shock, required a coronary bypass, closure of ventricular septal defects, mitral valve replacement, aneurysmectomy, and temporary pacemaker wires. The outcome was successful.


Preferential binding of tri-substituted thyronine analogs by bullfrog tadpole tail fin cytosol. The relative strength of binding of several triiodothyronine (T3) analogs by cytosol prepared from the tail fin of the bullfrog tadpole has been tested and compared with their thyromimetic activity in tail tissue. In competitive binding experiments, four tri-substituted analogs were bound much more strongly than two tetra-derivatives. Correlation between binding and relative thyromimetic activity was observed only for three triiodo-substituted compounds, triiodothyronine, its methylene bridge analog and the acetic acid analog. The affinity for T3 was 250 times that of T4, making it unlikely that the T3 binding sites in tadpole tail fin cytosol bind T4 under physiological conditions. The difference in binding by tadpole tail fin cytosol constitutes one of the largest differences observed between T3 and T4 in a potentially significant biological system.


Angiodysplasia of the colon: diagnosis and treatment. Gastrointestinal hemorrhage of obscure origin remains a difficult clinical problem, but newer methods of study, particularly endoscopy and angiography, have made inroads into this morass of diagnostic dilemmas. Vascular malformations represent entities that are relatively infrequent of occurrence and also difficult of detection. These characteristics render them particularly refractory to recognition. Once diagnosed, however, they are quite readily treated surgically, without resort to "blind" resections or multiple bowel entries. This report deals with three instances of obscure but important persistent blood loss into the gastrointestinal tract. In each instance, identification by customary diagnostic methods was unsuccessful, but was finally made through endoscopy and promptly cured through surgery. The bleeding in all 3 cases proved pathologically to have been caused by vascular malformations, which we have subsumed under the term "angiodysplasia."


Combined immunodeficiency in foals in Arabian breeding: evaluation of mode of inheritance and estimation of prevalence of affected foals and carrier mares and stallions. Combined immunodeficiency (CID), a defect in both B- and T-lymphocytes, was found to occur in 2.3% of 257 foals of Arabian breeding. All affected foals died by 5 months of age. The belief that CID is transmitted as an autosomal recessive genetic defect was supported by results from matings of dams and sires that had previously produced affected foals. Based on a prevalence of 2.3%, the proportion of carriers of the CID trait among the adult population surveyed was estimated to be 25.7%. Recent descriptions of other immunologic defects in foals emphasized the need for careful differential diagnosis. Disorders that could be confused with CID include failure in passive transfer of immunoglobulins from dam to foal, via colostrum; transient hypogammaglobulinemia; agammaglobulinemia (associated with B-lymphocyte deficiency and normal T-lymphocytes), and selective IgM deficiency.


Inhibition of transformation and transfection in Haemophilus influenzae Rd9 by lysogeny. Haemophilus influenzae Rd9 lysogenic for temperate bacteriophage N3 was found to be virtually nontransformable and nontransfectable. This inhibition of transformation and transfection was due partly to the decreased capacity of competent lysogenic cells for irreversible binding of deoxyribonucleic acid (DNA) and partly to some events taking place after adsorption of the DNA. The unadsorbed DNA was not degraded by the competent lysogenic cells.


Immunoinhibition of ristocetin-induced platelet aggregation. Human platelets washed and fixed in paraformaldehyde aggregate in the presence of the antibiotic ristocetin and normal plasma. This aggregation response is abolished after digestion of the fixed platelets with chymotrypsin. Antisera to fixed washed platelets were produced in rabbits and absorbed with chymotrypsin-treated, fixed washed platelets. Monovalent Fab fragments obtained from the isolated gamma-globulin fractions of the antisera blocked ristocetin-induced aggregation of fixed washed platelets in buffer and normal platelets in platelet-rich plasma. By double-antibody immunoprecipitation, it was shown that the antibody which blocked the ristocetin reaction interacted with a platelet membrane surface protein of mol wt 155,000. The results suggest that the glycoprotein I complex on the surface of the human platelet mediates ristocetin-induced von Willebrand factor-dependent platelet aggregation.


Avidity of anti-DNA antibodies in serum and IgG glomerular eluates from patients with systemic lupus erythematosus. Association of high avidity antinative DNA antibody with glomerulonephritis. Significant differences in both specificity and avidity of anti-DNA antibodies were observed in the sera of groups of patients with active systemic lupus erythematosus glomerulonephritis, active systemic lupus erythematosus without nephritis, and in IgG eluates obtained by DNAase digestion of isolated glomeruli from glomerulonephritic kidneys. With methylated albumin-kieselguhr fractionated 3H-HeLa DNA as a source of native or single-strand DNA antigen in a modified Farr assay, an increased level of antibody to native DNA was associated with active systemic lupus erythematosus, particularly active nephritis. The avidity of antinative DNA estimated from plots of the reciprocals of bound and free antigen according to the Sips distribution formula was significanly lower in active glomerulonephritis sera than in sera from patients with active systemic lupus erythematosus without nephritis. However, antinative DNA of uniformly high avidity was found in the glomerular eluates. Avidity of single-strand DNA antibodies did not differ in the various patient groups. The data stronly supprot a major role for high avidity antinative-DNA in DNA/antiDNA immune complex-induced glomerular injury in systemic lupus erythematosus.


Malignancy in rheumatic disease: interrelationships. Patients with inflammatory arthritis and malignancy comprise two distinct populations. One group represents the chance occurrence of malignancy and rheumatic disease. These patients have symmetric polyarthritis, chiefly classic rheumatoid arthritis, and react positively to the rheumatoid factor test. There is no temporal relationship between tumor onset and rheumatic disease onset. In the second group, there may be a causal relationship between the malignancy and the rheumatic disease. These patients have asymmetric rather than symmetric arthritis and test results are negative for rheumatoid factor. There is a close temporal relationship between the onset of the tumor and the onset of the rheumatic disease. The mortality rate is significantly higher than in patients with symmetric polyarthritis. In 80 percent of women with asymmetric arthritis and malignancy, the tumor is mammary carcinoma. This indicates the advisability of a careful breast examination in this group of women.


The active E-rosette test: a sensitive in vitro correlate for human delayed-type hypersensitivity. The "active" rosette test was adapted as an in vitro assay and correlated with human delayed cutaneous hypersensitivity (DCH) to two microbial antigens. Peripheral lymphocytes were purified from donors known to be responders or nonresponders to PPD-tuberculin or tularemia on the basis of prior DCH reactions. Skin test antigen, incubated with lymphocytes from antigen-sensitive donors, produced a significant increase (+2 S.D.) in the ability of the lymphocytes to form active rosette-forming cells (A-RFC) when compared to lymphocytes cultured without antigen. Skin test antigen incubated with lymphocytes from nonsensitive donors produced no increase in their A-RFC. The optimal dose of each antigen was approximately 100 ng/ml. The percentage of A-RFC rose to maximum levels between 3 and 4 hr after the addition of antigen to the lymphocytes incubated at 37 degrees C. The assay appears to be specific for the antigen to which the individual demonstrates DCH. This assay may provide a new in vitro method for investigating mechanisms of cell-mediated immunity and a rapid diagnostic test for sensitization to microbial antigens.


Ionophorous activity and murine B lymphocyte mitogens. The relationship between ionophorous and B cell mitogen activity has been investigated. Most known ionophores were nonmitogenic for mouse spleen cells. In addition, when tested in a bilayer lipid membrane (BLM) apparatus, most types of B cell mitogens were nonionophorous. However, excitability-inducing material (EIM), a high m.w. polymeric protein, which is a channel-forming ionophore, was a potent mitogen for mouse B lymphocytes. Similarly, keyhole limpet hemocyanin (KLH), a high m.w. polymeric protein, which is a B cell mitogen, is a channelforming ionophore. The mitogenic activities of these two compounds were not due to contamination with endotoxin since they produced weak or absent responses in the limulus lysate clotting and rabbit pyrogenicity assays, and were also mitogenic for spleen cells of endotoxin-low responder C3H/HeJ mice. Both the mitogenic and ionophorous activities of EIM and KLH were dependent on their polymeric structure since dissociation of these compounds into monomeric subunits markedly decreased both activities. However, heat denaturation destroyed their ionophorous ability but preserved their mitogenicity, thereby demonstrating that ionophorous activity was not essential for B cell activation. These data suggest that B cell mitogens do not necessarily act as primary ionophores. However, we propose that these molecules intercalate into the lipid portion of the cell membrane, and that this interaction initiates the process of B cell activation.


Reaginic antibody formation in the mouse. IX. Enhancement of suppressor and helper cell activities of primed spleen cells. Attempts were made to increase the activity of suppressor cells in vitro. Antigen-specific suppressor cells were induced by i.v. injections of urea-denatured ovalbumin (UD-OA) into OA-primed mice. Nonadherent splenic lymphocytes from the UD-OA-treated mice were incubated at 37 degrees C for 24 hr with either OA or OA-bearing macrophages and lymphocytes harvested from the culture were examined for the ability to suppress primary anti-hapten antibody response on nonirradiated mice to DNP-OA. The results showed that the suppressive activity of the lymphocytes increased after culture of the cells with OA or OA-bearing macrophages. Similar results were obtained when nylon column-purified T cell-rich fraction of the lymphocytes were similarly cultured. The suppressive activity was associated with theta-bearing lymphocytes and was specific for OA. Suppressor cells were not induced by the culture of OA-primed lymphocytes with OA. The helper function of splenic lymphocytes from both UD-OA-treated mice and OA-primed mice was enhanced by the culture of the cells with OA-bearing macrophages but not by culture with OA in the absence of macrophages.


Requirement for non T-cells in the generation of cytotoxic T lymphocytes (CTL) in vitro. II. Characterization of the active cells in the spleen of nude mice. Small numbers of LN cells will produce many more cytotoxic lymphocytes on in vitro culture with allogeneic stimulator cells if spleen cells from nu/nu mice are also present throughout the culture period. All cytotoxic cells produced are T cells and arise from precursors in the LN component. The nude spleen component appears to be providing a required non-T cell which has been lost from the LN component through dilution. At least two active subpopulations of cells, differing in sedimentation velocity, adherence properties, radiation sensitivity, and antigen recognition properties can be identified in the nu/nu spleen. The first, the dominant activity in normal nu/nu spleen, is nonadherent, radiation sensitive, and can synergize with either syngeneic or allogeneic LN cells provided both are different from the same alloantigens in the stimulator population. The second, found in nu/nu spleen cells precultured with alloantigen, sediments more rapidly, is adherent, and radiation resistant, and need not be allogeneic to the stimulator cells to synergize with LN cells. The first subpopulation may give rise to the second.


Anti-thymocyte autoimmunity in BALB/C mice accompanying immunization to a syngeneic lymphoma. As immunization of BALB/c mice to the syngeneic P1798 lymphoma is effected by administration of iodoacetamide-modified P1798 cells, serum antibodies appear which are reactive with P1798 and normal BALB/c thymocytes, splenocytes, and peripheral blood lymphocytes. Anti-P1798 serum also cross-reacted with thymocytes from AKR, DBA/2, and C3H mice as well as the allogeneic lymphoma 6C3HED. Anti-P1798 serum was unreactive with the Thy-1 deficient L1210 lymphoma. Multiple absorptions of anti-P1798 serum with normal BALB/c thymocytes or brain or P1798 removed antibodies to P1798 and thymocytes commensurately. Normal BALB/c liver and kidney did not absorb antibody activity. Treatment of a BALB/c splenocyte suspension with anti-Thy 1.2 serum and complement removed the population of spleen cells which were capable of reaction with anti-P1798 serum. The data suggest that antibodies to P1798 and thymocytes are the same and that specificity may be directed toward a Thy-1 related structure but without distinguishing Thy-1.1 and Thy-1.2.


Studies on the mechanism of lymphocyte- mediated cytolysis. VIII. The use of con A to delineate a distinctive killer T cell subpopulation. Alloimmune spleen cells (C57BL/6 anti P815), but not normal spleen cells, lyse syngeneic (EL4) target cells in the presence of Con A. Con A dependent cytotoxicity was mediated by T cells and required the continued presence of lectin. Cytolysis in the presence of a succinylated derivative was equivalent to that seen with the parent Con A molecule. In contrast to previous reports of Con A dependent cytolysis, however, we conclude that lysis is not primarily caused by directly cytotoxic T cells. The reasons for this conclusion are: 1. Removal of directly cytotoxic cells by adsorption on P815 monolayers did not alter the Con A dependent cytolysis of EL4 cells; 2. Populations in which no direct T killers were demonstrable (e.g., spleen cells harvested 5 days after alloimmunization) lysed both P815 and EL4 cells in the presence of Con A; and 3. Con A dependent cytolysis, but not direct cytotoxicity, could be induced by culturing normal C57BL/6 spleen cells for 4 days with a sonicated extract of P815 cells. We hypothesize that the cell "activated" to lyse targets in the presence of Con A is a T cell which has differentiated lytic potential following alloantigenic stimulation, but has either insufficient density or affinity of antigen receptors to serve as a directly cytotoxic cell. The role of Con A is viewed as 2-fold: i) to "bridge" killer and target cell, and ii) to "activate" the effector.


Mitogenic responsiveness and monocyte-lymphocyte interaction of early and late rosette-forming cell populations of human peripheral blood lymphocytes. Adherent cells in human peripheral blood mononuclear cells were removed by the attachment to the plastic surface of tissue culture dishes. After removal of adherent cells, early rosette-forming cells (early RFC), which were characterized by early (5 min) rosette formation with sheep blood cells (SRBC) at an SRBC to lymphocyte ratio of 8:1, were separated from nonrosetting cells by sedimentation on Ficoll-Hypaque gradient. Total (60 min) rosette formation was carried out with the early RFC-depleted cell population on the gradient interface by the use of neuraminidase-treated SRBC at an SRBC to lymphocyte ratio of 20:1 and the resulting rosette-forming cells (late RFC) were sedimented by gradient centrifugation. These T cell subpopulations, early RFC-enriched and late RFC-enriched, were reasonably pure with respect to the ability to bind SRBC and contained less than 0.5% monocytes. Monocyte preparations, which were obtained after vigorous washing of the adherent cell layers on tissue culture dishes, responded to phytohemagglutinin P (PHA-P) or concanavalin A (Con A) with negligible incorporation of 3H-thymidine. There was no significance difference in the responsiveness to PHA-P between early RFC-enriched and late RFC-enriched populations either in the absence or in the presence of graded numbers of additional autologous monocytes. However, the response of early RFC-enriched population to Con A was significantly poor as compared with that of late RFC-enriched one unless additional monocytes were added. In the presence of 20% autologous monocytes in the culture, the Con A-induced response of early RFC-enriched population was markedly enhanced to reach close to that of late RFC-enriched population. These results suggest that early RFC and late RFC might be different from each other in their responsiveness and in their need for monocytes on the stimulation with Con A.


Immunosuppression of T lymphocyte function by fractionated serum from tumor-bearing mice. Sera from mice with transplanted 3-methylcholantrene-induced tumors have been shown previously to inhibit the function of normal lymphoid cells. When chromatographed on Sephadex G-150, the fraction eluting with immunoglobulin has been shown to inhibit the proliferative response of normal spleen cells to concanavalin A and to inhibit the in vitro antibody response to a T-dependent antigen, but has a lesser effect on the antibody response to a T-independent antigen. This paper deals with studies on the mode of action of the serum factor. The immunoglobulin containing fraction of serum from tumor-bearing mice inhibited the in vitro generation of both allogeneic and syngeneic cytotoxic lymphocytes. Time course studies demonstrate that the serum fraction inhibits the generation of antibody-producing and cytotoxic lymphocytes if added during the first 2 days of a 5-day culture. Serum fractions added after day 2 had no effect on the in vitro response. The serum factor appears to inhibit the generation of specific T cell function during the proliferative stage of development but has no effect on the differentiation stage which leads to either antibody-producing cells or cytotoxic lymphocytes.


Lack of interaction of circulating T cells with phytohemagglutinin in bacillary positive untreated lepromatous leprosy patients--identification of subpopulation of lymphocytes by shifts in electrophoretic mobility. Incubation of human peripheral blood lymphocytes from normal healthy subjects with phytohamagglutinin (PHA), causes the reduction of the surface charge of a subpopulation of T cells by 1363 +/- 242 e.s.u./cm2. The affected subpopulation was predominantly the high charge-bearing cells identifiable with early (10 min) rosette-forming cells with sheep erythrocytes. Purified lymphocytes obtained from untreated bacillary-positive, lepromatous leprosy patients contained high charge-bearing T lymphocyte subpopulation. However, incubation with PHA did not result in the shift of electrophoretic mobility of these cells, suggesting the absence of interacting sites for the mitogen on the surface of these cells. The absence of mitogen-interacting sites is not an inherent trait of leprosy patients; the surface charge of lymphocytes from Dapsone-treated bacillary-negative subjects was reduced upon incubation with PHA. A close correlation was found between the number of cells whose charge alters on incubation with PHA and the transformation index obtained with this mitogen.


Tolerizing effect of DNP-ficoll on IgE antibody production. A/J and DBA/1 mice were infected with 750 third-stage larvae of Nippostrongylus brasiliensis and immunized with 1 mug dinitrophenylated N. brasiliensis extract (DNP-Nb) with 1 mg Al(OH)3 to produce high titers of anti-hapten IgG1 and IgE antibody. Partial tolerance to the production of anti-hapten IgG1 and IgE antibody could be induced by DNP-Ficoll from 5 weeks before to 1 week after the DNP-Nb immunization. The tolerized state persisted through the duration of the experiments. However, no tolerizing effect could be demonstrated on secondary antihapten IgE antibody production induced by DNP-Nb. Moreover, DNP-Ficoll failed to evoke anti-hapten IgG1 or IgE antibody production.


Immunologic properties of bacterial lipopolysaccharide (LPS). IV. Cellular basis of the unresponsiveness of C3H/HeJ mouse spleen cells to LPS-induced mitogenesis. Lymphoid cells obtained from the C3H/HeJ mouse strain respond abnormally to LPS in vitro, as shown by the fact that they are unable to make a mitogenic response to some LPS preparations and make only a low mitogenic response to other LPS preparations. In contrast, cells from a closely related C3H substrain, the C3H/St, are highly responsive to both types of LPS preparations. Experiments were carried out to determine the cellular basis of these genetically determined LPS response differences. This question was approached by studying the mitogenic response to LPS in cultures containing mixtures of various combinations of B cells, T cells, and macrophages from C3H/HeJ and C3H/St mice. Experiments utilizing an LPS preparation to which the C3H/HeJ is totally unresponsive (negative LPS) revealed, first, that either spleen cells, or partially purified T cells and/or macrophages obtained from C3H/St, could not restore the ability of C3H/HeJ spleen cells to respond to LPS, indicating that the C3H/HeJ is not deficient in an LPS-specific helper cell population which may be required for mitogenesis. Secondly, the addition of either spleen cells or partially purified T cells or macrophages from the C3H/HeJ to spleen cells from the C3H/St did not inhibit the mitogenic response to LPS, suggesting that the presence of suppressor cell activity is also not involved. Experiments analogous to those described, except utilizing another LPS preparation to which the C3H/HeJ is partially responsive (positive LPS), also failed to demonstrate reconstitutive or suppressive effects when C3H/HeJ and C3H/St spleen cells were admixed. The results obtained indicate that the defect in the C3H/HeJ mouse strain that limits its responsiveness to positive LPS and which renders it totally unresponsive to negative LPS appears to be an intrinsic defect in the capacity of B cells to react to the mitogenic stimulus of LPS.


Natural cytotoxic reactivity of human lymphocytes against a myeloid cell line: characterization of effector cells. Using a series of techniques to identify and deplete various peripheral blood lymphocyte subpopulations, we studied the cytotoxic reactivity of normal individuals against the myeloid cell line K-562 in a 4-hr 51chromium-release assay. Depletion of lymphocytes bearing complement receptors had a variable, usually negligible effect on cytotoxicity. In contrast, depletion of lymphocytes bearing Fc receptors abrogated target cell lysis. Separation of lymphocytes with high-affinity binding of sheep red blood cells (SRBC) evidenced by rosette formation at 29 degrees C yielded a population of rosette-forming cells containing few cytotoxic cells, whereas separation of total E-RFC under optimal rosetting conditions produced a rosette fraction containing a major proportion of the effector cells. These data indicate that the cytotoxic lymphocyte in this system is Fc receptor positive, largely complement receptor negative, and may possess low density or low affinity receptors for SRBC.


Hapten-specific IgE antibody responses in mice. VII. Conversion of IgE "non-responder" strains to IgE "responders" by elimination of suppressor T cell activity. Mice of the inbred strains SJL (H-2s) and AKR (H-2k) are "non-responders" and "low-responders," respectively, in terms of their capacity to develop antibody responses of the IgE class when immunized with conventional proteins and hapten-protein conjugates under conditions optimal for eliciting IgE responses in "high-responder" mice, such as BALB/c (H-2d), to these same antigens. For example, BALB/c mice preimmunized with ASC and then challenged 7 days later with DNP-ASC develop peak augmented primary IgE anti-DNP antibody responses of 320 PCA units, whereas SJL and AKR mice develop responses which are 16-fold and 4-fold lower, respectively. However, pretreatment of the latter two strains with appropriate doses of either x-irradiation (150 R), cyclophosphamide (100 mg/kg) or ALS (150 mul) before carrier-preimmunization strikingly enhances the magnitude of IgE antibody responses in such mice to levels as high as 64-fold above those of untreated control mice of the same strains. Evidence obtained in these experiments indicates that the capacity of such maneuvers to to convert poor IgE responders to high responder status reflects elimination of nonantigen-specific suppressor T lymphocytes which are naturally present and normally function to suppress or "dampen" the IgE antibody response in a relatively selective manner. It appears that these cells modulate IgE responses by acting at least at two distinct points: 1) The most effective activity seems to be at the level of induction of carrier-specific helper T cells; 2) A second locus of inhibitory activity is more distal in the response, either impeding helper T cell-B cell cooperative interactions or suppressing B cell differentiation and/or function directly. Taken collectively, these observations demonstrate that the state of poor responsiveness of the SJL and AKR strains for the IgE antibody class is not a reflection of a genetic inability to develop IgE responses but rather a manifestation of a genetic capability to actively inhibit IgE antibody synthesis.


Studies on the mechanism of lymphocyte-mediated cytolysis. IX. Relationships between antigen recognition and lytic expression in killer T cells. The relationship between antigen recognition and lytic expression by killer T cells was studied by co-culturing two effector cell populations. When antigen recognition was bidirectional (e.g., b anti-d cells cultured with d anti-b) there was a loss of lytic activity in both populations. In contrast, when antigen recognition was unidirectional (e.g., a anti-d co-cultured with d anti-b) then the loss of lytic activity only occurred in that direction; i.e., there was a marked decline in the d anti-b activity but no change in the a anti-d population. These studies suggest: i) that mere proximity to a killer cell does not lead to target cell death; ii) that accommodation of the T cell's antigen receptor is necessary for the cell to express its lytic potential; and iii) there is direct linkage between the T cell's antigen receptor site and its killing mechanism.


Regulatory factors produced by lymphocytes. II. Inhibition of cellular DNA synthesis associated with a factor inhibiting DNA polymerase alpha activity. Supernatants of phytohemagglutinin-stimulated human tonsil cells contain two growth inhibitory factors. These factors, called inhibitors of DNA synthesis (IDS), reduce (3)H-thymidine incorporation into mitogen-stimulated lymphocytes and into growing HeLa cells. By Sephadex chromatography, these factors have volumes of distribution corresponding to about 80,000 and 40,000 daltons. Both factors inhibit the activity of calf thymus DNA polymerase alpha in cell-free assays (termed inhibitor of DNA polymerase, IDP). The larger factor, which is chromatographically separable from alpha-lymphotoxin (alpha-LT), is completely inactivated by heating at 70 degrees C for 15 min. This treatment does not destroy alpha-LT. Using supernatants from PHA-stimulated tonsil cells cultured for 5 days in serum-free medium, we attained a 150-fold purification with a succession of molecular sieving, ion exchange, and adsorption chromatographic procedures. Although not purified to homogeneity, the extensive copurification of IDS and IDP activities and their identical heat inactivation profiles suggest that they are the same entity. IDP separated free of alpha-LT inhibits thymidine incorporation into HeLa cells without causing cell death. alpha-LT purified free of IDS does not inhibit thymidine incorporation into HeLa cells, not even at concentrations 7000 times that necessary to kill 50% of growth-inhibited L cell cultures.


Kinetic studies of a tumor-induced leukemoid reaction in mice. A transplantable murine breast carcinoma in mice was associated with marked leukemoid reaction. Within 1 week of subcutaneous implantation of tumor the leukocyte count began to increase and reached average levels of 165,000 leukocytes per cubic millimeter within 18 days. This represented an increase in mature neutrophils primarily, although other blood leukocytes were modestly increased as well. The total number of neutrophils per humerus was increased but no increase was detected in the number of myloblasts, promyelocytes, or myelocytes. The tritiated thymidine-labeling index of the latter three cells was not significantly changed during tumor growth. The number of progenitor cells forming granulocytic and mononuclear cells in vitro was decreased in the marrow during tumor growth. Colony-stimulating activity in plasma was slightly increased during the early phase of tumor growth and decreased during later phases. Emergence time of blood neutrophils was normal, as measured by labeling with tritiated thymidine, but decline in labeled cells was abnormally slow in tumor-bearing mice. There was a shift of erythropoiesis to the spleen, but total erythropoiesis appeared to be normal in most mice. Surgical excision of the tumor resulted in prompt reversal of the leukemoid reaction. In the aggregate these results are consistent with a hypothesis that the leukemoid reaction was the result of increased blood transit time of neutrophils primarily, rather than increased neutrophil production.


Identification of a B-cell surface structure involved in antigen-dependent triggering: absence of this structure on B cells from CBA/N mutant mice. CBA/N mice have an X-linked B-cell maturation defect which is reflected in part in an absence or dysfunction of a subclass of mature B cells. We have immunized the defective male offspring of the mating (CBA/N female X BALB/c male) with BALB/c spleen cells. The resulting antiserum (alphaLyb3) selectively reacts with a component on the surface of a portion of B cells from a panel of H-2 different mouse strains. Binding of alphaLyb3 serum to this B-cell subclass results in substantial (10- to 20-fold) enhancement of the antibody response to low doses of SRBC. Both binding and enhancing activity are removed by absorption with B cells from B6 and BALB/c, but not CBA/N mice. Absorption of the serum with bone marrow cells, T cells, or thymocytes from Lyb3+ strains does not remove activity. Since the enhanced plaque-forming cell (PFC) responses are specific for the immunizing antigen, and since no PFC response is produced by injection of the antiserum alone, this enhancement probably reflects a second signal produced by specific interaction between antibody and the surface Lyb3 component. Moreover, this signal can partially replace the requirement for T cells in the production of antibody to a "thymus-dependent" antigen. These findings (taken in conjunction with the previously described immune defects in CBA/N mice and other studies of B-cell maturation) suggest to us that Lyb3 is a cell surface component expressed selectively on a mature B-cell subclass. This component is important in B-cell triggering by antigen and fails to develop in CBA/N mice, due to a dysfunction of a regulatory gene on the CBA/N X chromosome.