A canine model for reaginic hypersensitivity and allergic bronchoconstriction.

Immunization of neonatal dogs with a conjugate of 2,4-dinitrobenzene and ovalbumin (DNP2-OA), using aluminum hydroxide as the adjuvant, elicited long-lasting (over 30 wk) anti-DNP and anti-OA IgE antibody responses of high titers as determined by homologous passive cutaneous anaphylaxis. Low antigen doses of 10 or 50 mug were more effective than the higher doses of 250 or 1,250 mug in inducing high IgE antibody levels. However, this method of immunization failed to elicity any detectable IgE antibody response in adult dogs. Bronchoprovocation with antigen of sensitized animals having IgE antibody titers in excess of 64 resulted in a marked increase in airflow resistance, which could be corrected by the administration of nebulized isoproterenol. On the other hand, sensitized animals with IgE antibody titers in the order of 64 did not manifest significant bronchoconstriction on inhalation challenge but developed anaphylaxis following intravenous injection of the antigen.


Lymphocyte responses to purified ragweed allergens in vitro. I. Proliferative responses in normal, newborn, agammaglobulinemic, and atopic subjects.

To evaluate cell-mediated immune responsiveness to pollen allergens in atopic subjects, we studied the deoxyribonucleic acid (DNA) synthetic responses of their cultured lymphocytes to purified ragweek antigens E, K, and Ra-3. Since lymphocytes from some highly ragweed-sensitive subjects gave poor proliferative responses when harvested on day 6, we undertook a series of dose-response and time-course studies in atopic and control subjects. Surprisingly, vigorous DNA synthetic responses to antigen E occurred with lymphocytes from all 45 subjects, including 19 highly ragweed-sensitive atopic and control subjects. Surprisingly, vigorous DNA synthetic responses to antigen E occurred with lymphocytes from all 45 subjects, including 19 highly ragweed-sensitive atop adults (8 immunotherapy treated, 11 untreated); 13 nonatopic controls; 4 newborns, and 9 agammaglobulinemic patients. The geometric mean of peak response counts per minute in all 45 subjects was 21,163 and in unstimulated cultures was 2,416 (p = less than 0.0001). The mean day on which the maximal responses occurred was 8.7, and the mean dose eliciting the maximum responses was 59 mug/ml. Statistical comparisons of the stimulated culture data revealed no significant intergroup differences. The finding of vigorous responsiveness to these purified pollen allergens by lymphocytes from nonatopic normal, newborn, and agammaglobulinemic subjects suggests that ragweed pollen antigens are either ubiquitous and lead to cell-mediated responsiveness in all subjects with intact cell-mediated inmunity, or that they may have miogenic properties in addition to their known antigenic properties.


Effects of histamine-sensitizing factor and cortisol on lymphocyte adenyl cyclase responses.

Levels of cyclic adenosime monophosphate (cAMP) in lymphocytes are regulated by beta-adrenergic agonists and PGE1. The effect of these agonists is potentiated by cortisol. Incubation of lymphocytes with histamine-sensitizing factor (HSF) leads to loss of response to epinephrine and PGE1. The response can be partially restored by cortisol. Incubation of lymphocytes with beta-adrenergic antagonists such as propranolol leads to the loss of beta-adrenergic agents but not PGE1. The inhibition by propranolol is not reversed by cortisol. These results suggest that the action of HSF and Bordetella pertussis vaccine is not mediated through the inhibition of beta-adrenergic receptors alone.


Platelet thrombopathy in asthmatic patients with elevated immunoglobulin e.

Abnormalities of second-wave platelet aggregation were demonstrated in 17 of 33 asthmatic patients in whom drug and diet intake were controlled in the hospital. Mean abnormal responses were significantly greater after epinephrine- (p less than 0.001), adenosine diphosphate-(less than 0.001), collagen- (p = 0.01), and thrombin- (p less than 0.001) induced platelet aggregation in patients with immunologically mediated asthma and serum IgE levels greater than 250 U/ml as compared to patients without immunologic factors and/or normal controls. Mean pollen-specific radioallergosorbent (RAST) binding was also significantly higher in patients with abnormal aggregation as compared to normal platelet responders (p = 0.02). Release of serotonin generally reflected abnormal aggregation patterns in asthmatic patients. Platelet factor 4 release was significantly decreased in the same groups of patients. These results suggest that the allergic state may affect platelet membrane responsiveness to multiple aggregating agents.


Effect of multiple injections of antigen on prolonged IgE antibody production in hypersensitive mice.

Multiple injections of ovomucoid were given to mice with ongoing prolonged IgE antibody production to that antigen. Two inbred strains and antigen doses ranging from 0.05 to 5 mug each injection, given intradermally and subcutaneously, were used. Mice treated in this manner showed a marked diminution of the Ig E antibody booster response as compared to controls. This decrease in booster response was antigen-specific. In addition, a protective effect from anaphylaxis was indicated. The mouse model continues to be a valuable tool for studies of certain IgE-mediated diseases.


Effect of histamine and methacholine on nasal airway resistance in atopic and nonatopic subjects. Comparison with bronchial challenge and skin test responses.

Serial nasal, intracutaneous, or bronchial challenges were carried out with solutions containing 2- or 3-fold increments in histamine (H) or methacholine (Meth) concentration until nasal airway resistance (NAR) increased by more than 100%, a large intracutaneous reaction was elicited, or FEV1 decreased by 20% or more. Thirty nonatopic and 48 asymptomatic atopic subjects were studied, the latter group divided into rhinitic patients with and without asthma. Several types of data analysis demonstrated there was no significant difference in the nasal or cutaneous effects of H or Meth between the atopic and nonatopic groups. Comparable results were obtained in a subgroup of 39 subjects (13 normal, 13 atopic, and 13 atopic with asthma) who underwent all six test sequences (i.e., nasal, cutaneous, and bronchial with both drugs). As expected, the asthmatics showed significantly increased bronchial reactivity to both agents. In comparison with Meth, H had a much greater effect on the nasal mucosa and skin than on the bronchi. It is concluded that, contrary to bronchial responses, but in accord with cutaneous reactivity, the nasal responses of nonatopic subjects, atopic persons with allergic rhinitis alone, and subjects with both allergic rhinitis and asthma show no intergroup differences on testing with H or Meth.


Study of possible mechanisms of basophil accumulation in experimental cutaneous candidiasis in guinea pigs.

It is known that certain lymphokine preparations, bacterial growth products, and factors released through complement activation have in vitro chemotactic activity for basophils. We have developed a model for acute cutaneous candidiasis in guinea pigs in which the lesions are characterized by infecting organisms in the keratin layer, early accumulation of polymorphonuclear leukocytes in the upper epidermis, and subsequent accumulation of basophils along the dermal basement membrane. The present study was undertaken to determine if any of the known chemotactic factors were operating in vivo to attract basophils. Both nonimmune guinea pigs and animals with established delayed hypersensitivity to candida had basophils in the infected skin. While immune animals showed more basophils than did nonimmune animals, the difference was not significant. Intradermal injections of a sonicate of candida or a candida growth filtrate did not cause significant accumulation of basophils. Decomplementation of the animals with cobra venom factor (CVF) did not significantly reduce the basophil numbers. Moreover, basophil accumulation occurred in animals with only minimal serum antibody to candida. These studies indicate that the basophil accumulation is due to a mechanism that is not dependent on cellular immunity, direct chemotactic activity in the candida extract, antibodies, or complement. Therefore, there may exist a previously unrecognized, nonimmunologic mechanism of chemotaxis for basophils which could possibly operate in other types of lesions and could even be involved with attraction of other types of cells.


Arthritis in older persons: recent advances in diagnosis and medical and surgical treatment. Section I. The interpretation and use of newer diagnostic studies. Introduction.

The diagnosis and the treatment of rheumatic diseases in older people pose special problems. Degenerative joint disease, almost universally present in the elderly, may not be the basis for the newly developing rheumatic symptoms. Systemic inflammatory disease may be confused with malignancy or it may be an initial manifestation of malignancy. Some drugs used to control central-nervous-system or cardiovascular disease may produce painful rheumatic syndromes. Results of laboratory tests used in the diagnosis of rheumatic diseases may be altered by other nonrheumatic disorders in older people. Papers in this symposium will explore these concepts in greater detail.


Symposium on arthritis in older persons. Section II. Drugs and intrasynovial steroid therapy. Intrasynovial steroid therapy: uses and abuses. (Summary of presentation).

The indications and contraindications for use of intrasynovial steroid therapy are discussed. When properly used, the intrasynovial injection of steroids is a valuable method of treatment.


Symposium on arthritis in older persons. Section IV. Surgery and rehabilitation. Total joint replacement: lower extremities (Summary of presentation).

In experience with total joint replacement in the lower extremity, to date, total hip arthroplasty has been the most successful. Total arthroplasty operations as applied to the knee and ankle are giving promising results. These methods offer new avenues for relief of pain and deformity and stabilization of arthritic joints in the lower extremity.


Current status of total joint replacement in the upper extremity.

The principles ot total joint arthroplasty recently have been expanded to the upper extremity, following the dramatic success with total hip and total knee replacement procedures. New problems have been encountered with the rebalancing of the soft tissues and the technical nature of joint mechanics in the upper extremities. Work on shoulder joint replacement is in the very early stages and of unknown success. Several prostheses are being used and tested. For elbow and wrist replacement, early and predictable success has been accomplished, enabling relief of pain and satisfactory motion. Total joint replacement in the fingers and thumb has provided excellent relief of pain but has been hindered by difficulties in rebalancing the soft tissues in patients with rheumatoid arthritis. It appears that total reconstruction of arthritic upper-extremity joints will be commonplace in the not-too-distant future. Clinical trials are being expanded, with increasing success.


Physical medicine and rehabilitation in the elderly arthritic patient.

The basic conservative therapy programs for elderly patients with arthritis include adequate physical rest and mental relaxation, analgesics, aspirin, and physical rehabilitation consisting of occupational and physical therapy with a good home therapy program providing appropriate balance between rest and activity. Proper protection from trauma and overuse of the involved joints, and appropriate nutrition can afford optimal improvement in health status and general resistance. Proper orientation of the patient regarding the nature of his disease and treatment program usually is required to obtain his full cooperation. A kind, encouraging, and understanding approach is most helpful in the elderly patient. Physical rehabilitation can help to relieve pain, decrease edema and deformities, improve muscle weakness and incoordination, and increase stamina. Difficulties with gait, transfers, and self-care can be solved or improved. Physical medicine and rehabilitation measures are important components of the challenging treatment of patients of all age groups who are afflicted with severe arthritis. It is most important to tailor these components of the treatment program to the problem presented by geriatric arthritic patients.


Medication procedures in a nursing home: abuse of PRN orders.

Nursing home patients often receive more drugs than needed. Drug incompatibilities frequently are found, and PRN orders are apt to be overused. Regulatory agencies require periodic physician review in the hope of eliminating these loose prescribing habits. A study was made of the drugs prescribed for 98 patients in a proprietary nursing home. The principal findings were that PRN orders can indeed be inappropriate and indiscriminately followed, and that the multiplicity of drugs often prescribed can lead to drug incompatibilities and to additional illness of the patient. Concern is expressed about the medication review process currently in vogue in nursing homes.


The use of mechanical and chemical restraints in nursing homes.

The use of mechanical and chemical restraints in nursing homes is a common practice, fraught with potential abuse. The patient's freedom of movement and right to an adequate medical and psychiatric evaluation are of the utmost importance. Restraints should be used only as a last resort and should not be a substitute for inadequate staffing or incomplete medical appraisal. Guidelines are offered that maximize the patients' freedom, maintain medical responsibility, and assure safety. Alternatives to the use of restraints are discussed.


Acquired hemophilia: a case report.

A case of acquired hemophilia is presented. Widespread blisters and then ecchymoses developed in a 79-year-old woman who was severely demented. Laboratory studies revealed specific complete inhibition of factor VIII in the blood. In any elderly patient with a bleeding diathesis and an abnormality in intrinsic coagulation, the presence of inhibitors to factor VIII should be suspected.


Procaine hydrochloride as a monoamine oxidase inhibitor: implications for Geriatric therapy.

The results of in vitro experiments showed that inhibition by procaine hydrochloride of monoamine oxidase (MAO) from either rat brain or liver was substrate-dependent. Procaine was more effective in inhibiting serotonin oxidation than phenylethylamine oxidation and had an intermediate effect on tryptamine oxidation. MAO activity in tissue homogenates from rats treated with procaine (150 mg/kg intraperitoneally) was inhibited most in liver, less in heart, and only very slightly brain for a duration of up to 8 hours. Procaine injected in that dose did not alter brain norepinephrine levels and elevated only slightly the brain serotonin levels. It did not protect against the degradation of exogenous radioactive tryptamine in brain. These data confirm and extend prior observations on in vitro inhibition of MAO by procaine and suggest that in high doses procaine may inhibit MAO weakly in vivo. If the reported usefulness of procaine preparations in treating geriatric patients indeed depends upon MAO inhibition, more effective inhibitors would seem to be available.


Immunoelectronmicroscopic localization of alpha-actinin in skeletal muscle cells.

The ultrastructural distribution of alpha-actinin in skeletal myocytes was studied by a sensitive method that permits localization of antigenic proteins in intact fixed cells rather than in glycerol estracted tissues or isolated cell fractions. Binding to the Z line of specific antiserum produced in rabbits immunized with highly purified alpha-actinin was demonstrated by deposition at this site of a reaction product of horseradish peroxidase that had been coupled to antigen-binding fragments of sheep anti-rabbit gamma globulin.


The relationship between innervation and the cholinesterases of the rat atrioventricular node.

During the first 4 postnatal days, the atrioventricular specialized tissue of the rat contains butyrylcholinesterase alone. The next 7 days are associated with a mixture of both acetyl and butyryl activity, but after the 12th day, acetylcholinesterase is found to predominate largely. It is suggested that this change in activity is related to the growth of adrenergic nerves into the heart on the 4th day. Administration of antinerve growth factor prevents the development of these nerves and is found to delay the onset of the change in cholinesterase activity from butyryl to acetyl from the 5th day until the 21st. Only after the 31st day is acetylcholinesterase the most prominent enzyme in treated animals.


Radioimmunoassay for murine lactoferrin, a protein marker of myeloid and mammary epithelial secretory cell differentiation.

A radioimmunoassay was developed for murine lactoferrin (LF), a non-heme, iron-binding glycoprotein which appears to be a specific biochemical marker of differentiation in several cell types. Lactoferrin was labeled with 125I by the chloramine-T method to yield a product having 20 muCi/mug protein and an isotope incorporation of 0.6 atoms of 125I per molecule. Separation of bound and free lactoferrin was accomplished by either of two procedures, a double-antibody technique or precipitation in the presence of 50% saturated ammonium sulfate. The entire assay, including counting, was accomplished in less than 2 days and had a lower limit of sensitivity and a range of 1 ng/ml and 1-32 ng/ml, respectively, using rabbit antiserum in a dilution of about 1:10,000. The binding between LF and rabbit antiserum exhibited two association constants having values of 1.8 x 10(11) and 1 x 10(9) l/mole. The assay was specific for lactoferrin and no cross-reactivity was observed with transferrin, a similar non-heme, iron-binding glycoprotein. Human lactoferrin specifically reacted with anti-mouse lactoferrin, but the binding was approximately 8000 times weaker than observed with mouse lactoferrin. Values for lactoferrin in milk and bone marrow granulocytes were obtained which agreed with levels obtained using other methods.


Isolation of human peripheral blood lymphocytes: modification of a double discontinuous density gradient of Ficoll-Hypaque.

Incubation of whole blood with adenosine diphosphate (ADP) and carbonyl iron prior to layering on a double discontinuous gradient of Ficoll-Hypaque selectively reduced the number of platelets and monocytes found at the upper lymphocyte interface after centrifugation. This modification in combination with a double discontinuous gradient results in a lymphocyte isolation method that is simple, rapid and reproducible.


Serological precipitation method for studying biosynthesis and secretion of immunoglobulins by human peripheral blood lymphocytes.

A reproducible, serological method to quantify radiolabeled immunoglobulin (Ig) synthesized and secreted by human peripheral blood lymphocytes is described. In contrast to indirect precipitation (rabbit antihuman Ig and goat antirabbit Ig), the direct coprecipitation method using human IgG and rabbit antihuman IgG F (ab)2 showed much smaller, non-specifically precipitable radioactivity (i.e., 2 approximately 14%) without affecting Ig radioactivity.


Purification and characterization of a peripheral protein from the sheep erythrocyte membrane.

A peripheral protein of the sheep red blood cell membrane has been purified to homogeneity. This protein is completely released from the membrane by osmotic shock. Its amino acid composition, molecular weight and subunit structure have been determined. Antibodies against this protein have been obtained in rabbits.


A comparison of various agarose preparations in a counter--immunoelectrophoresis (CIE) system for assaying urinary myoglobin.

Twenty-two samples of commercial agarose were utilized as the gel matrix in a counter-immunoelectrophoresis (CIE) for detection of urinary myoglobin. When different samples were tested under identical conditions, significant differences in the detectable levels of myoglobin by CIE could be traced to the quality of the agarose used. The quality of agarose preparation could be improved by repurification using polyethylene glycol precipitation. The necessity of using purified agarose when assaying for urinary myoglobin by CIE is stressed. This is particularly important when the test is used in the early detection of myocardial infarcts.


Improved assay for monocyte chemotaxis using frozen stored responder cells.

Frozen stored human mononuclear cells were compared with non-frozen cells as responder cells in the monocyte chemotaxis assay. Frozen stored cells were found to inhibit lower background migration, resulting in greater experimental-to-control ratios. The use of frozen cells also greatly improved the speed, standardization of conditions and day-to-day reproducibility of the assay procedure. Frozen cells were at least as sensitive as fresh cells for detecting low chemotactic factor concentrations and were superior for detecting differences in concentration.


Solid phase radioimmunoassay using labelled antibodies: a conceptual framework for designing assays.

A simple theoretical model for the antigen-antibody reaction is presented ans used to evaluate the optimum conditions for designing solid phase radioimmunoassay (RIA) using labelled antibodies. Both theoretical and experimental data are presented, using a wide variety of antigens and their corresponding antibodies. The types of RIA is described include the direct, the indirect, sandwich assays for detecting either antigen or antibody. The experimental results confirm in a semiquantitative manner that the greatest sensitivity of the RIA is achieved when the smallest amount of labelled antibody is used, that whenever possible the antigen/antibody ratio should be greater than unity (greater than 1), and that the formation of the antigen-antibody comples is dependent on the mass action effect.


Effects of methotrexate on proliferation of human keratinocytes in vitro.

Normal human keratinocytes, propagated as epithelial outgrowths in vitro, were exposed to different concentrations of methotrexate (MTX) for different periods of time. After a 1-hr exposure, DNA synthesis was inhibited in a reversible manner. No change in the mitotic index was observed. After a 6-hr exposure, both DNA synthesis and mitosis were inhibited, again in a reversible fashion. Prolonged exposure (24 hr) resulted in irreversible mitotic inhibition even when followed by recovery periods of 168 hr. The effective concentrations of MTX in vitro were similar to those described previously in vivo.


Stereologic baseline data of normal human epidermis.

Stereologic techniques for electron microscopic morphometry have been applied to normal human interfollicular epidermis of the submammary and iliac crest regions. The aim was to obtain objective baseline data for the study of epidermal morphometric pathology. The results, expressed mainly in surface, volume, and numerical densities of epidermal components and keratinocyte organelles, revealed ascending or descending gradients throughout the epithelial strata. The cytoplasmic ground substance remained almost constant in the four studied layers. No important regional differences were found between the epidermal morphometric parameters at either site. The epidermis showed striking volumetric composition similarities with other keratinizing epithelia.


Griseofulvin causing hyperhemopexinemia and hepatic proliferation in mice: an in vivo and in vitro study.

Concentrations of hemopexin, a porphyrin-binding serum protein synthesized exclusively in the liver, increased significantly and concomitantly with levels of erythrocyte and liver protoporphyrin and coproporphyrin in mice made porphyric with 1% griseofulvin in the feed. Liver weights of porphyric mice increased remarkably. In comparison with controls, the ratio of the weight of normal to porphyric livers was at 10 days 1:2.1, at 21 days 1:2.8, and at 46 days 1:3.8. This increase in liver size was accompanied by increased cell division. The hepatic hyperplastic tissue fragments survived in vitro for several weeks and could be subcultured. The cultured cells, like those of the original liver, showed intense protoporphyrin fluorescence in the cytoplasm.


Granulocyte function in patients with chronic renal failure: surface adherence, phagocytosis, and bactericidal activity in vitro.

The defects in host defense mechanisms that explain the enhanced susceptibility to infection of patients with chronic renal failure are not understood, and previous studies concerning function of polymorphonuclear leukocytes (PMNL), the major antibacterial defense, conflict. Therefore, the antimicrobial functions of PMNL obtained from chronically uremic patients and serum factors essential for PMNL activity were evaluated. The potential modifying effect of high concentrations of serum from uremic patients on PMNL of uremic patients was determined, and granulocyte adherence, an activity related to recruitment of cells to inflammatory sites, was measured. Phagocytosis of 14C-labeled Staphylococcus aureus and bactericidal activity were normal and unaffected by high concentrations of uremic serum. Serum from uremic patients opsonized staphylococci and yeast normally. Oxidative metabolism of PMNL [14C-1]glucose oxidation, O2 consumption, and quantitative protein iodination) was normal, as was PMNL adherence. If the uremic patient has an increased risk of infection, this risk cannot be ascribed to defects of PMNL responses that have been studied in these patients.


Wound infection by an indigenous Pseudomonas pseudomallei-like organism isolated from the soil: case report and epidemiologic study.

A 27-year-old farmer in the Oklahoma panhandle was pinned under his overturned tractor for 2 hr and received superficial and deep lacerations. He contracted an infection of a pelvic wound with an organism that had cultural and biochemical characteristics identical to those of Pseudomonas pseudomallei. Identical organisms were recovered from soil taken from the site of the accident. The organism isolated from the wound proved to be less virulent in guinea pigs than usual laboratory strains of P. pseudomallei; fatty acid analysis showed a distinctly different pattern from that of laboratory strains of P. pseudomallei. The infecting organism may be a variant of P. pseudomallei or a new species of Pseudomonas.


Depressed neutrophil motility in patients with recurrent herpes simplex virus infections: in vitro restoration with levamisole.

The random migration and chemotaxis of neutrophils from 10 patients with recurrent infections with herpes simplex virus were assessed. Chemotaxis to endotoxin-activated serum was markedly diminished in this group, but random migration was only mildly reduced, and chemotaxis to hydrolyzed casein was normal. The effects of the immunostimulant drug levamisole on the chemotaxis of neutrophils were assessed both in vitro and in patients after 150 mg of the drug was taken daily for three days. The defective chemotactic response could be corrected in vitro by treatment of the neutrophils with 10(-3) M levamisole. Of 10 patients treated with levamisole, five showed improved chemotaxis after three days, but no improvement in neutrophil function was observed in the other patients.


Reproducible method for induction of pulmonary coccidioidomycosis in mice.

Intranasal instillation of an inoculum has been suggested as a method for establishment of experimental pulmonary infections. Because we encountered untoward variation in rates and times of death with use of this method for inducing coccidioidomycosis in mice, a simple method for direct intratracheal infection was devised. With doses of 50 or 100 arthrospores of Coccidioides immitis, mortality rates were 80%-90% from 14 to 25 days after infection by the intratracheal route and 20%-60% from 12 to 24 days after infection by the intranasal route. The procedure for intratracheal infection caused only slight morbidity, and the method resulted in consistent rates of disease.


Clinical and serologic study of four smallpox vaccines comparing variations of dose and route of administration. Primary subcutaneous vaccination.

As part of a large study designed to develop schedules for smallpox immunization with reduced morbidity, 799 children received primary immunization with subcutaneous vaccine. Four vaccines (New York City Board of Health calf lymph, New York City chorioallantoic membrane, CV-1 and Lister) at three dosages (l0(3), 10(4), 10(5) pock-forming units) were administered. Eighty-two percent responded with hemagglutination-inhibiting antibody at one month, and only 22% with neutralizing antibody. There was no correlation between concentration of vaccine and antibody response. The CV-1 strain was slightly but significantly less likely to induce antibody than the other three vaccines. Subcutaneous vaccination was not associated with significant temperature elevation in general. However, some children developed erythema at the vaccination site or a swollen arm, and fever did tend to occur in this small group. Four children developed nonspecific vaccinia-related rashes, and one had generalized vaccinia.


Immunization against tularemia: analysis of the effectiveness of live Francisella tularensis vaccine in prevention of laboratory-acquired tularemia.

A retrospective analysis was made of cases of laboratory-acquired infections with Francisella tularensis among civilian employees at Fort Detrick, Maryland. The incidence and clinical presentation of tularemia during the decade 1950-1959, when the phenol-killed Foshay vaccine was used routinely for immunization of employees, were compared with similar data from the first decade (1960-1969) after the live tularemia vaccine had come into use. The incidence of typhoidal tularemia fell (from 5.70 to 0.27 cases per 1,000 at-risk employee-years; P less than 0.001), whereas the incidence of ulceroglandular tularemia remained unchanged (from 0.76 to 0.54 cases per 1,000 at-risk employee-years). Ulceroglandular tularemia in employees immunized with live vaccine was characterized by clinical signs and symptoms that were milder than those in employees vaccinated with the Foshay vaccine.


Transmission of hepatitis B virus to gibbons by exposure to human saliva containing hepatitis B surface antigen.

A pool of whole-mouth saliva collected from five human carriers of hepatitis B surface antigen, subtype adr, was found to contain antigen particles with mean diameters of 23.3 and 41.8 nm as seen by immune electron microscopy. Two gibbons received subcutaneous injections of the pooled saliva and developed serological and, in at least one animal, biochemical evidence of hepatitis B virus infection at 12 and 22 weeks, respectively. Although none of eight other gibbons that were exposed by the nasal or oral routes were infected, the experiment demonstrated that human saliva can serve as a vehicle for the transmission of hepatitis B virus.


Differential distribution of ciliated epithelial cells in the trachea of hamsters: implications for studies of pathogenesis.

The morphology of the inner aspect of the adult hamster trachea was examined by scanning electron microscopy. Relatively large patches of unciliated cells were observed in the epithelial layer. The patches, which covered several hundreds to thousands of square microns, were most conspicuous on the ventral surface of the trachea, especially in the middle third. The frequency of these areas of unciliated cells, both isolated and in patches, was much greater in hamsters than in mice, rats, or cats. Greatest ciliation in the hamster trachea was observed over the strip of trachealis muscle between the open ends of the cartilaginous rings. Areas with the heaviest ciliation also had the greatest activity of cellular metabolism, as measured by the tetrazolium reduction assay. The attachment of tritium-labeled cells of Mycoplasma pneumoniae was inversely correlated with extensive ciliation, since the greatest numbers of counts were found on the middle third and ventral regions of the tracheal surface. The results of this study suggest that the regional differences in ciliation of respiratory epithelium in hamsters may influence studies of pathogenesis and isolation of M. pneumoniae and that these differences should therefore be considered and controlled in the experimental design.


Glomerular protein synthesis in proteinuric rats.

Intraperitoneal injection of bovine albumin in rats readily induces proteinuria. It is already known that this proteinuria is accompanied by ultrastructural and enzyme changes in the glomeruli. The purpose of the present study is to investigate whether these phenomena were associated with an increased glomerular protein synthesis or, more specifically, with an increased glomerular basement membrane (GBM) synthesis. Young rats were made proteinuric by the injection of bovine albumin. Their glomeruli were isolated by the sieve technique and incubater either with [U-14C]proline or with [U-14C]leucine and [U-14C]tyrosine. Control incubations were run with normal glomeruli. Glomerular proteins were hydrolyzed and analyzed for amino acid composition and radioactivity. Specific activities of all three amino acids were always higher in proteinuric glomeruli, but there was no difference in the ratio 14C-hydroxyproline/14C-proline. The similar increase in incorporation of the three amino acids must result from an increased synthesis of different cellular proteins and cannot be considered as a preferential increase in GBM synthesis.


In vivo and in vitro effect of bacterial endotoxin on erythroid precursors (CFU-E and ERC) in the bone marrow of mice.

Erythropoietin injection raised within 24 hr. the number of CFU-E in the femoral marrow of polycythemic mice by 837 percent. Endotoxin given at 0 to 24 hr. before erythropoietin nearly abolished this CFU-E increase. Endotoxin in the culture medium did not inhibit erythroid colony formation, but in vivo endotoxin suppressed erythropoietin-induced differentiation of proerythroblasts from their precursors. Endotoxin thus suppresses marrow erythropoiesis either by inhibiting transformation of erythroid precursors into CFU-E or by causing the disappearance, perhaps by emigration, of CFU-E from the marrow.


Estimation of glucose turnover with stable tracer glucose-1-13C.

Glucose turnover was measured in normal and disbetic dogs by the dilution of glucose-1-13C and glucose-1-14C tracers infused simultaneously at constant rates. In order to quantify the stable isotope, an enzymatic assay for the analysis of glucose-1-13C was developed and evaluated. CO2 from C-1 glucose was evolved by coupling hexokinase, glucose-6-phosphate dehydrogenase, and 6-phosphogluconic dehydrogenase activities. The 13C/12C ratio of the CO2 was measured with a high-precision magnetic-deflection double-collector mass spectrometer, and the radioactivity of 14CO2 was quantified by liquid scintillation. The ratio of 13C/12C was reproducible in assays of CO2 evolved from either naturally occurring or 13C-enriched glucose. Furthermore, systemic glucose production rates measured with 13C- and 14C-labeled tracers were similar over a wide range from 2 to 12 mg./kg.-min. Thus, glucose-1-13C may be employed as a tracer for glucose metabolism in human subjects without incurring the risk of radiation.


The influence of fatty acids on the binding of bilirubin to albumin.

The influence of free fatty acids (FFA's) on the albumin binding of bilirubin was studied in vitro in the plasma of infants with neonatal hyperbilirubineamia and in solutions employing crystalline albumin to which bilirubin and FFA (oleic acid) were added. The bilirubin saturation index (SI) was utilized to distinguish between that fraction of bilirubin bound at the primary (high-affinity) site of albumin and bilirubin bound at secondary sites from which it is easily dissociated by salicylate. The relative saturation of albumin with bilirubin was also measured by addition of salicylate to whole blood samples where bilirubin was also measured by addition of salicylate to whole blood samples where bilirubin dissociated from the albumin could be sequestered by the red cells. The present studies indicate that FFA's influence the binding of bilirubin in two ways. At molar ratios of FFA to albumin (2:1 to 4:1), the FFA's compete with bilirubin for binding at the high-affinity site so that a significant portion of the bilirubin is transported at secondary sites, making it susceptible to displacement by water-soluble organic anions. At high molar ratios (greater than 5:1) FFA's compete with bilirubin for albumin binding at the secondary sites as well. In contrast to crystalline albumin where the first two molar equivalents of FFA do not influence the binding of bilirubin to albumin, all FFA concentrations in hyperbilirubinemic plasma reduce the affinity of albumin for bilirubin at its high-affinity site even though there is a molar excess of albumin over bilirubin.


Human monocyte glucose metabolism in lymphoma.

Glycolysis (GU), hexose monophosphate shunt (HMPS) activity, and Krebs cycle activity were determined in monocytes from 32 normal subjects and 22 untreated patients with lymphoma. All of these parameters of glucose metabolism were significantly elevated in the lymphoma patients as a group when compared to normal subjects, suggesting monocyte activation by lymphoma. When the results were evaluated on the basis of sex and age, significant enhancement of glucose metabolism by lymphoma was evident in the 13 male patients compared to 18 normal men but not in monocytes from nine women with lymphoma compared to 14 normal subjects. Male patients over and under 40 years of age had significantly enhanced HMPS activity compared to normal subjects (p less than 0.05 and p less than 0.01, respectively), and GU was significantly increased in patients over 40 years (p less than 0.01). In contrast, no significant differences were noted in any of the values of women with lymphoma compared to normal subjects matched according to menstrual status. This discrepancy is apparently due to the high values for HMPS noted in healthy women, especially menstruating women. Although lymphoma may activate monocyte glucose metabolism, this effect can be masked by the normally high values seen in healthy women. The sex of the subject must be considered in evaluating human monocyte function and metabolism.


Muscle water and electrolytes in uremia and the effects of hemodialysis.

The effects of acute uremia and hemodialysis on water and electrolyte distribution and intracellular pH (pHi) of skeletal muscle were studied in dogs. Acute uremia resulted in an increase in intracellular muscle water and Ca++ content, and a fall in both intracellular Na+ concentration and the calculated muscle membrane potential (EM). Muscle pHi did not change. The increase in muscle Ca++ content was prevented by previous parathyroidectony. The administration of parathyroid extract to previously parathyroidectomized uremic animals resulted in a rise in muscle Ca++ content to levels similar to those observed in intact uremic animals. Hemodialysis with standard dialysate resulted in a normalization of both muscle Em and Ca++ content but did not affect either muscle intracellular water, Na+ concentration, or pHi. Hemodialysis with hypertonic dialysate (glycerol or mannitol) resulted in a slight fall in intracellular muscle water content toward normal but did not change muscle intracellular Na+ concentration or pHi. The muscle membrand permeability of Na+ relative to K+ (PNa/PK) was not changed by hemodialysis with either standard dialysate or dialysate with mannitol added. Glycerol, however, appeared to increase PNa/PK to about 10 times the normal value. The observed changes in muscle water and solute content may be related to the increased muscle irritability seen in acute uremic patients. These changes, however, are only partially corrected by hemodialysis with standard or hypertonic dialysate.


Monocyte IgG receptor activity, dynamics, and modulation-normal individuals and patients with granulomatous diseases.

Studies of monocyte IgG receptor activity by tritration of rabbit Forssman antibody and fluid phase inhibition with human IgG1 and IgG3 indicate increased activity for cells from patients with sarcoidosis in comparison to normal individuals. IgG receptor activity was also increased for cells from patients with tuberculosis and, to some degree, for Crohn's disease patients. Monocyte C3 receptor activity is increased in sarcoidosis and Crohn's disease. Following phagocytosis of latex particles, IgG receptor activity remains for monocytes from sarcoidosis patients, whereas activity transiently disappears for monocytes from normal individuals. Incubation with multistranded polynucleotides increases IgG receptor activity for normal subjects and has no significant effect on cells from patients with sarcoidosis or Crohn's disease. The findings suggest that circulating monocytes from patients with sarcoidosis, Crohn's disease, and tuberculosis are activated in vivo as reflected by increased IgG and C3 receptor activity.


Colestipol, clofibrate, and phytosterols in combined therapy of hyperlipidemia.

Studies were carried out to determine effects of combined chemotherapy in patients with hyperlipidemia. In one study, 14 patients were treated first with colestipol and then with the combination of colestipol and clofibrate. In a second study, six patients were given clofibrate followed by addition of phytosterols. The following measurements were made in most patients: (1) plasma lipid concentrations, (2) fecal excretions of neutral steroids and bile acids, and (3) lipid composition of gallbladder bile. In six patients of the first study, hepatic secretion rates of biliary lipids and pool sizes of bile acids were also estimated. In the first study, colestipol alone caused a marked increase in fecal bile acids that resulted in a sizable decrease in plasma cholesterol concentrations (average 21 percent). In several patients, however, triglycerides were increased somewhat by colestipol. Despite interruption of the enterohepatic circulation of bile acids, the bile acid pool was not reduced, since a compensatory increase took place in bile acid synthesis. Also, except in one patient who developed gallstones following institution of colestipol, saturation of gallbladder bile with cholesterol was not markedly increased by this drug alone. Addition of clofibrate frequently produced a further decrement in plasma cholesterol, and the mild hypertriglyceridemia induced by colestipol was reversed. However, colestipol plus clofibrate usually caused a striking increase in saturation of gallbladder bile. Previous studies have shown that clofibrate causes a flux of cholesterol from tissue pools by simultaneously decreasing cholesterol synthesis and increasing its excretion. To further increase cholesterol excretion, phytosterols, which block cholesterol absorption, were added to clofibrate in the second study. Although phytosterols did not cause a further reduction in plasma cholesterol in these particular patients, they nevertheless greatly enhanced cholesterol excretion.


Functional and metabolic properties of human asialofibrinogen.

The role of sialic acid in the functional and metabolic properties of purified human fibrinogen was investigated. Fibrinogen treated with Vibrio cholerae neuraminidase released 90 percent of its sialic acid without evidence of proteolysis, as indicated by the presence of intace A alpha, B beta, and gamma chains on sodium dodecylsulfate (SDS)-polyacrylamide gels of the reduced asialoprotein. The thrombin and Reptilase clotting times of human asialofibrinogen were shortened compared to those of normal fibrinogen. Fibrinopeptide release was normal in rate and amount, but asialofibrin monomer aggregation was increased at both low and high ionic strength. Similarly, the asialo-derivative of fibrinogen Philadelphia (functionally characterized by impairment of fibrin monomer aggregation) demonstrated shortening of its thrombin and Reptilase times and improvement in its monomer aggregation especially at high ionic strength. Asialofibrin showed a normal capacity to form cross-linked fibrin as demonstrated by normal gamma-chain dimerization and alpha-chain polymerization. Simultaneous metabolic studies of human normal fibrinogen and asialofibrinogen in rabbits revealed only a modest decrease in the half-life of the asialoprotein compared to the intact protein, with no preferential uptake of the asialo-derivative by the liver. Control studies with rabbit normal fibrinogen and asialofibrinogen in rabbits revealed the same modest difference in half-life. Thus, asialofibrinogen clots faster due to enhancement of its monomer aggregation, has a normal capacity to form cross-linked fibrin, and does not differ significantly in its metabolic properties from normal fibrinogen. The possible influence of sialic acid in the functional abnormality of some congenital dysfibrinogenemias is discussed.


Computer densitometry for angiographic assessment of arterial cholesterol content and gross pathology in human atherosclerosis.

Sequential change studies in human atherosclerosis are desirable in disease regression trials but are now limited by dependence on the occurrence of epidemiologic end-points. Prior radiographic studies have pertained to advanced obstructive atherosclerosis. This is a study of measures applied by computer-generated densitometry of angiograms to assess early to advanced nonobstructive atherosclerosis. Measures are based on pathologic and angiographic appearance of all stages of atherosclerosis and include image edge roughness, local width, and local contrast density changes. Femoral angiograms were made in 21 cadavers under simulated clinical conditions, with a pressurized radiopaque casting material. Full-size color photographs were made of 10 cm. segments of opened artery, with matching cast and arterial specimens analyzed for cholesterol content. Four graders, on two occasions, sequenced the photographs in increasing order of disease on the basis of the International Atherosclerosis Grading scheme. The correlation between the two sessions was 0.93. Thirteen computer indices correlated significantly with visual grade and cholesterol and were allowed to compete in a step-wise regression for best indices of prediction. Computer index correlation coefficient for visual grade prediction was 0.86, and for cholesterol content, 0.84. Computer densitometry measurement appears useful in the evaluation of all stages of atherosclerosis as recorded angiographically and obviates the necessity for exacting visual comparisons of large numbers of films.


The assessment of the bile salt-nondependent fraction of canalicular bile water in the rat.

The bile salt-nondependent fraction of canalicular bile water has been measured by the extrapolation to zero of the regression line representing the relationship between bile flow and bile salt secretion. This extrapolation assumes that the secretion of bile salts whatever their concentration, carries the same amount of water per molecule. The purpose of this study was to test this assumption. Rats were depleted of bile salts by a bile fistula and infused with sodium taurocholate at rates varying from 30 to 500 mmumol/min. Bile salt secretion was linear with bile salt infusion at any concentration. Values of bile flow and bile salt secretion were grouped according to bile salt concentration, and regression lines calculated. The slopes of the regression lines changed from 0.090 at bile salt concentrations below 10 mM to 0.012 at bile salt concentrations between 30 and 45 mM, (p less than 0.001). These results indicate that the relationship between bile flow and bile salt secretion in the rat cannot be represented by only one regression line. Consequently, the rate of secretion of the bile salt-nondependent fraction of canalicular bile water cannot be measured by the extrapolation of this single regression line.


Quantitative osmotic fragility and disease states: a preliminary study.

The Kalmedic D-3 Fragiligraph was used to obtain both cumulative and derivative osmotic fragility data. Several instrumental modifications and several procedural changes combined to make the data more reproducible and more easily obtained. An analytical expression employing but two parameters was found to give excellent fits for the cumulative data, and when differentiated, reproduced the experimental derivative data equally well. The curve fitting procedure used is given in detail. Data obtained on a limited number of subjects with beta-thalassemia or multiple sclerosis are presented. The interpretation of these data by techniques common to the literature is compared with the procedure developed in this paper.


Human serum protein binding of cephalosporin antibiotics in vitro.

The published values for serum protein binding of antibiotics vary considerably depending upon the method and experimental conditions used. A rapid, simple, and standardized ultrafiltration procedure for determination of the serum protein binding of antibiotics has been developed and used to compare the binding characteristics of four marketed cephalosporins. The human serum protein binding of cephradine, cephalexin, cephalothin, and cefazolin at 37 degrees C. and physiological pH (7.4) was found to be 13.8, 12.4, 71.2, and 89.2 per cent, respectively. These values fall within the range of published values for these antibiotics.


Plasma catecholamines via an improved fluorimetric assay: comparison with an enzymatic method.

The fluorimetric method of Renzini and Valori, utilizing alumina and ion exchange chromatography, was modified to include dl-3H norepinephrine (3H-NE) for individual plasma NE recoveries and mercaptoethanol as a stabilizing agent for the fluorescent lutines. Plasma NE and epinephrine (E) were measured in hypertensive patients, and results were compared with those of the enzymatic method of Engelman in duplicate plasma specimens. The correlations of the NE and the total plasma catecholamine concentrations determined by the two methods were both r = 0.98 (p less than 0.001) and that of the E concentrations was r = 0.79 (p less than 0.01). The reproducibility of the method for measuring 10 ml. aliquots of pooled plasma yielded a standard deviation of less than 10 per cent of the mean. The fluorimetric method was more economical, less time-consuming, and as reliable as the enzymatic method for quantitating plasma catecholamines.


A simplified micromethod for assay of reserve bilirubin binding capacity.

The Sephadex gel elution method for assay of the reserve bilirubin binding capacity (RBBC) of the serum of jaundiced newborns has been modified to permit its application on a routine basis in the clinical chemistry laboratory. The volume of sample required has been reduced to 0.2 ml. of serum or less, the time required to perform the assay decreased to 30 to 45 minutes, and the reliability of the results enhanced by unidormly higher absorbance readings. The RBBC as determined by this modified micromethod agrees within 1 mg./dl. with that obtained from the original method. The results are not affected by flow rates through the columns, which vary by as much as a factor of 5, but are interfered with by sample hemolysis, lipemia, and a high proportion of direct-reacting bilirubin. The RBBC assay is a useful tool in the management of neonatal hyperbilirubinemia, and the simplification of the method should permit its greater use on a routine basis.


Nonspecific test reaction for antibodies to hepatitis B surface antigen in chronic HBAg carriers.

Anti-HBs was undetectable in the plasma of 303 HBsAg-positive blood donors. The apparent reactivity of anti-HBs in the chromatographically isolated IgG fractions of these antigen-positive donors was shown to be nonneutralizable by HBsAg. The false-positive antiHBs reactions were apparently due to the isolation and concentration of IgG from the plasma which was initially nonreactive for anti-HBs.


Problems of indirect immunologic assay of specific enzyme activity.

The estimation of specific activity of variant enzymes is important for understanding the mechanism of inherited enzyme deficiency. Direct determination of specific enzyme activity is often difficult. Indirect immunologic methods, i.e., the quantitative neutralization method and the electroimmunoassay method using specific antiserum, have been used for estimating the specific activity of variant enzymes. The validity of these indirect methods was examined with the use of normal and variant human glucose 6-phosphate dehydrogenase (G6PD), and three different anti-G6PD sera. The specific activities of purified normal, partially denatured normal, partially purified normal, and partially purified preparations of four different G6PD variants were estimated by the indirect methods. The values estimated by the neutralization method and that obtained by the electroimmunoassay method were substantially different, and different antisera gave different values for the given G6PD preparations. The values estimated by the indirect methods do not reconcile with the specific enzyme activity determined by the direct determination. Therefore, care should be taken in deducing the specific enzyme activity from the immunologic assay.


Screening of hearing in babies.

96 babies (aged 7-9 months) were tested both by conventional screening of hearing procedures and by pure tones. 12 of these babies or just over 12% failed the screening test of hearing by conventional procedures (5 of them were subsequently found to suffer from varying degrees of hearing loss) as compared to 29 babies or just over 30% who failed in pure tone testing (including the 5 babies with confirmed hearing losses). It is concluded that provided conventional procedures are followed carefully their applicability, flexibility and validity are superior to pure tone testing procedures.


Acute spreading osteomyelitis of the skull complicating frontal sinusitis.

Three patients with acute spreading osteomyelitis of the skull complicating a frontal sinusitis are presented. The pathology and clinical features of this complication are discussed. Early rigorous antibiotic treatment accompanied by surgical intervention to drain purulent collections in the sinuses and scalp has been effective in controlling the disease. One patient required a craniectomy for removal of an area of chronic ostemoyelitis. The other two patients maintained on antibiotics for three months have shown no evidence of progression to chronic osteomyelitis and have remained free from relapse.


The effect of anaesthesia on middle ear function (a preliminary report).

The preliminary findings of an investigation into the effects of anaesthesia on middle ear function have shown a transient worsening lasting about 6 days. It is suggested that results of hearing tests carried out within a week of general anaesthesia should be treated with caution.


Black hairy tongue. A scanning electron microscopic study.

A patient with tongue malignancy associated with a black hairy tongue is presented. Specimens from e area fo the black hairy tongue and from a normally appearing part were studied with the scanning electron microscope. The "hairs" consisted of elongated filiform papillae due to accumulated keratinized layers. In-between these layers, fungi and bacteria were found. The aetiology of the blck hairy tongue in this patient is discussed.


Surface phase separation and collapse of the stearate anion--alkaline earth cation complex.

The surface properties of fatty acid and fatty acid-alcohol mixtures were examined at 22-24 degrees C. At pH 12, sodium stearate forms a rigid surface film that generates an equilibrium spreading pressure of 16.5 dynes/cm. At pH 12, stearate-alkaline earth cation films collapse at the air-water interface and do not generate significant equilibrium spreading pressures. The rate of film collapse depends on the counterion decreasing in the sequence Ba2+ greater than Sr2+ greater than Ca2+. Stearate-stearyl alcohol mixtures form solid (condensed) films that are relatively stable and behave initially as homogeneous surfaces in their selectivities for counterions. Stearate-oleyl alcohol mixtures form fluid (expanded) films that are unstable. Lateral phase separations occur rapidly in fluid films and the stearate-alkaline earth cation phase collapses. The rate of film collapse in the fluid mixtures also depends on the counterion decreasing in the sequence Ba2+ greater than Ca2+. These surface properties suggest how a lipid anion may function as an ionophore in the translocation of alkaline earth cations.


Plasmalogenase activities in neuronal perikarya, astroglia, and oligodendroglia isolated from bovine brain.

Plasmalogenase (EC 3.3.2.-, 1-alk-1'-enyl-2-acyl-sn-glycero-3-phosphorylethanolamine aldehydrogendrolase) activities were assayed with the plasmalogens in dispersed myelin as the substrate. The activities were 6,7-mumoles/mg protein per hr in oligodendroglia from white matter, and 1.1 and 0.6 for astroglia and neuronal perikarya from gray matter. Myelin had no plasmalogenase activity. Thus, both the normal catabolism of myelin plasmalogens and the accelerated hydrolysis of plasmalogens in demyelination is probably carried out by oligodendroglial plasmalogenase.


A facile hydrolysis-solvolysis procedure for conjugated bile acid sulfates.

Methods for hydrolyzing and solvolyzing conjugated bile acid sulfates were compared on reference mixtures of conjugated and unconjugated bile acid sulfates gas-liquid chromatography to assess recovery, and thin-layer chromatography and zonal scanning to define the products occurring after hydrolysis. Conventional methods in which solvolysis preceded vigorous alkaline saponification gave incomplete recoveries. However, essentially complete recovery of primary and secondary bile acid sulfates was obtained with a mild alkaline saponification procedure followed by acidification and extraction into ether, in shich complete solvolysis was shown to occur within 12 hours. Based on these findings, we developed and validated a simple hydrolysis-solvolysis procedure; the method features mild alkaline hydrolysis, acidification to pH 1, and extraction with ether followed by a 1-hour incubation.


A novel spray reagent for phospholipid detection.

Ammonium pentachlorooxomolybdate in a solution of 7-9 N H2SO4 was found to be an excellent spray reagent for the specific detection of phospholipids on thin-layer chromatograms. It is better than the usual molybdenum blue reagent due to its greater sensitivity and its ability to eliminate the problem of the development of background blue color on prolonged exposure.


Composition-structure-function correlations in the binding of an apolipoprotein to phosphatidylcholine bilayer mixtures.

We have studied the lipid binding of apoC-III with two types of mixed vesicles of DMPC (dimyristoyl phosphatidylcholine) and DPPC (dipalmitoyl phosphatidyl-choline). DMPC vesicles mixed with those of DPPC produce a macroscopic mixture in which the DMPC and DPPC vesicles remain intact. The circular dichroism and fluorescence spectra of apoC-III in the presence of this macroscopic mixture exhibit major changes near the transition temperature of each of the pure lipids, confirming the independent existence of the two PC's. Combining DMPC:DPPC macroscopic mixtures with apoC-III above the transition temperature, Tc 23 degrees C, of DMPC produces an isolatable complex consisting of 4:1 DMPC:DPPC. If the DMPC and DPPC are within the same vesicle, this microscopic lipid mixture has properties that are functions of the temperature and lipid composition. Spectral analysis of apoC-III in the presence of the micromixtures reveals a single transition, which occurs between the respective thermal transitions of DMPC (23 degrees C) and DPPC (41 degrees C). The lipid: protein complexes isolated from the microscopic mixtures have a DMPC: DPPC ratio identical to that of the vesicle with which the apoprotein was mixed; the formation of these complexes is most efficient above the temperature range where these microscopic mixtures induce major structural changes in the apoprotein. The absence of the preferential binding to DMPC observed in the macroscopic mixtures suggests that apoC-III interacts with large lipid domains within a vesicle and does not selectively bind the low melting DMPC. The temperature dependence of the binding of apoC-III to the microscopic mixtures may be due to phase separation or to cocrystallization; our data support the latter process.


Induction of HMG CoA reductase by the administration of 20,25-diazacholesterol.

This paper describes the direct examination of HMG CoA reductase activity in rats treated with 20,25-diazacholesterol. Conversion of acetyl CoA and HMG CoA to mevalonate increased to over 200% of control values in the microsomes and in the 12,000 g supernatant of liver homogenates after 5 days of treatment. The time course of induction coincided with the development of hypocholesterolemia. Animal weights, liver weights, and microsomal protein content did not vary significantly between animal groups. Incubations to which the compound was introduced in vitro in concentrations as great as 0.5 mM produced no significant difference from control incubations. Similar treatment of the animals with 7-ketocholesterol, a cholesterol derivative reported to repress HMG CoA reductase activity in tissue cultures, produced no appreciable difference in reductase activity or serum steroid levels in vivo.


Growth and acyltransferase activity of rabbit mammary gland during pregnancy and lactation.

A bimodal change in yield and microsomal protein content of rabbit mammary gland was observed with the progress of pregnancy and lactation. The initial stimulus took place on day 22 of pregnancy and the second during early lactation. Palmitoyl-CoA:monopalmitoyl-sn-glycerol 3-phosphate palmitoyltransferase activity was monitored concurrently. This enzyme in rabbit mammary microsomes is composed of two isoenzymic species that differ with respect to the physical nature of the substrates with which each interacts. The activities of the two isoenzymes were recorded at progressive stages of pregnancy, lactation, and involution to determine if a regulatory role could be assigned to either or both species. Although the patterns were indefinite, total transacylase activity did increase over this period, i.e., the specific activity of LPAT-alpha was 12 and 24 nmoles/mg protein per min in pregnancy and lactation, respectively, while that of LPAT-beta rose from zero to 90 nmoles/mg protein per min over the same period. The time of harvesting in relation to the interval between nursing periods is discussed in the light of these results.


Analogs of natural lipids. III. Nonequivalence of methyl groups in methylated phospholipids.

The dimethyl esters of a series of diastereoisomeric cyclopentanoid analogs of phosphatidic acid (A.J. Hancock, M.H. Stokes, and H.Z. Sable. 1977. J. Lipid Res. 18: 81-92.) have been studied by proton NMR spectroscopy at 60, 100, and 300 MHz. The signals of the P-O-CH3 protons near delta 3.80 show the expected doubling due to the 31P-1H coupling. In addition, the spectra of three of the isomers show additional multiplicity the line separation (in Hz) being proportional to the frequency of the spectrometer. This multiplicity is due to the nonequivalence of the two methoxyl groups on phosphorus, predictable from their diastereotopic nature. The same explanation is proposed for similar observations on other compounds made by other authors. The practical utility of symmetry considerations in lipid chemistry is discussed briefly.


Analogs of natural lipids. IV. Synthesis and properties of cyclopentanoid analogs of phosphatidic acid.

A new series of phosphatidic acid analogs has been synthesized in which the glycerol moiety of diacylglycerophosphoric acid is replaced by each of the three isomeric cyclopentane-1,2,3-triols (1,3/2, DL-1,2/3, and 1,2,3/0). Of the seven possible configurational and positional phosphatidic acid analogs of this series, five isomers have been obtained and characterized by spectroscopic methods and microanalysis. Four of the five isomers are 1-(or 3-)phosphoryl derivatives, while the fifth is a 2-phosphate. The analogs were prepared in configurationally pure form by unequivocal synthetic procedures involving selectively blocked intermediates: acyl migration was avoided by the use of mild deblocking procedures. The anhydrous lipid products, all of which are dipalmitoyl esters, are solids indefinitely stable at room temperature in the free acid or potassium salt form; they have chromographic mobility and melting points similar to dipalmitoyl glycerophosphoric acid the dipotassium salts bind water of hydration tenaciously, remaining hydrated after drying in vacuo at 100 degrees C. NMR spectra of dimethyl esters of some of the analogs show nonequivalence of the two methyl groups, consistent with the diastereotopic nature of those groups. In addition to their intrinsic interest as conformationally restricted acidic lipids, the analogs are now available as starting materials for the synthesis of the more complex acidic and amphoteric lipids required for our exploitation of these cyclopentanoid analogs as unique probes for the study of lipid-lipid and protein-lipid interactions.


Stimulatory action of cycloheximide on glucose metabolism in the rat epididymal fat pad.

The action of cycloheximide on some parameters of glucose and lipid metabolism was studied in vitro in epidiymal fat pads from fasted rats. Incubation of fat pads with cycloheximide (1 mug/ml) for 2 hours resulted in a two-fold increase in glucose uptake, glucose oxidation, incorporation of glucose into lipids, and reesterification of free fatty acid. The increase in glucose oxidation was evident in experiments in which [U-14C], [1-14C], or [6-14C]glucose was added to the media, but it was absent when the media were supplemented with pyruvate. Incorporation of glucose into glycogen and accumulation of lactate in the medium were not seriously modified by the presence of cycloheximide. The stimulatory effect of cycloheximide on incorporation of glucose into lipids was absent when insulin or cortisol was added to the medium. A cycloheximide-mediated increase in glucose uptake seems to be responsible for the subsequent changes in glucose metabolism, and would seem to be independent of an inhibition in protein synthesis; puromycin and actinomycin D did not mimic the cycloheximide action on glucose incorporation into lipids.


Measurement of cholesterol synthesis in kinetically defined pools using fecal steroid analysis and double labeling technique in man.

The purpose of the study was to develop a kinetic method for measurement of different parameters of cholesterol metabolism in man using labeled cholesterol precursors that could initially be incorporated even into the slowly exchangeable cholesterol pool. For this purpose, tritiated water and [2-14C]mevalonate were given to five normocholesterolemic subjects and the activities for serum cholesterol and body water were measured serially for up to eight weeks. Elimination of cholesterol was measured by fecal analysis of neutral and acidic steroids. For comparison, two subjects received a mixture of [4-14C]cholesterol and [2-3H]mevalonate. The data were subjected to multicompartmental analysis by computer, with the assumption that synthesis occurred in two compartments. The rapidly exchangeable cholesterol (pool 1) and the fractional hydrogon transport constant from body water to cholesterol could not be measured directly; therefore, the influence of two different mass transport values was tested. The best fit was obtained with the smaller mass of cholesterol in pool 1 associated with a hydrogen transport constant of 0.700 (32 out of 46 hydrogens originate from water). Kinetic analysis of the data allows estimates of the exchangeable cholesterol mass, flux rates of cholesterol between pools 1 and 2, and synthesis of cholesterol separately in the two pools. The results of computer analysis suggested that, in contrast to what has been assumed earlier on the basis of studies with radiolabelled cholesterol, 22-53% of endogenous cholesterol synthesis took place in pool 2 from body water and that this synthesis tended to correlate with the total body fat mass. The study with [2-3H]mevalonate and [4-14C]cholesterol indicated synthesis in pool 2 to be 20-22% of the total. Up to 50% of the DL[2-14C]mevalonate dose was incorporated into cholesterol. The fractional incorporation of DL-mevalonate into pool 2 was correlated with that of tritiated water, indicating that both precursors studied yielded essentially the same kinetic result.


The extent of supernormal ventricular excitability in man.

The supernormal period is an interval of increased excitability found in Purkinje fibers and thought to discretely neighbor T wave termination. Thereafter, excitability is thought to be constant. We examined the extent of the supernormal period in normokalemic patients at normal heart rates, determining excitability in terms of threshold voltages required for right ventricular bipolar excitation at 10-30 sec msec intervals of diastole. In sinus rhythm (ten patients), thresholds during maximal excitability (Emax) following the relative refractory period were only 5.2% +/- 0.1 less than late diastolic thresholds (P less than 0.05). However, a discrete change from supernormal to normal period was never demarcated. Instead, in each patient all thresholds fell within 95% confidence limits of the linear relation: Threshold = a volts/second + ThresholdEmax. In fact, five of ten patients showed constant or diminished excitability as diastole progressed. In ventricular drive (six patients), threshold was constant throughout diastole. A supernormal period was never seen. Thus, excitability changes were progressive throughout diastole after sinus beats, and diastolic excitability was constant after ventricular beats. T wave termination did not signal a discrete period of increased excitability analogous to the supernormal period of Purkinje fibers.


Computer analysis of changes in frank vectorcardiograms of 666 normal infants in the first 72 hours of life.

Frank vectorcardiograms (VCGs) were collected on magnetic tape for 666 normal newborn infants at 1, 6, 12, 24, 36, 48, 60, and 72 hours after birth and analyzed by computers. The final total included 1,337 VCGs for white babies and 413 for blacks. No previous report has been made for the normal neonate with such a large sample, and no previous substantiation exists of possible age or sex differences at this early age. This study establishes a statistically significant change in vectorcardiographic patterns over the first three days, specifically in the measurements P duration, QRS duration, maximal spatial QRS amplitude, S in lead x, and T in lead z, as well as for several time-normalized QRS vectors. (P less than or equal to .005.) Racial differences were significant for T waves in lead z. This study supports the use of vectorcardiographic standards sensitive to the age of the newborn as well as to race.


A dipole plus quadrupole lead system for human electrocardiography.

A lead system was constructed to extract dipole and quadrupole components of cardiac sources from surface electrocardiograms (ECGs) recorded at 16 sites. The lead system was based on an analysis of a computerized model of a multipole equivalent cardiac generator in a homogeneous torso. The model was previously determined from extensive geometric and electrocardiographic data obtained from one subject. Dipole components estimated with the lead system were 89% accurate for the original subject. Evaluation of the lead system on this subject and in 59 other subjects included calculation of the effect of non-dipolar sources on the values of the estimated dipole components, comparison of the consistency of equivalent sources found independently at two origins in the heart region, and reconstruction of ECGs from lead system components. Dipole consistency at the origins was maintained over the wide range of age, weight, and body shape which characterized the subject population. Whereas quadrupole terms did not agree as well as the dipole terms, inclusion of the quadrupole reduced ECG reconstruction errors by a factor of about three compared to errors for the dipole alone. Together, the dipole and quadrupole accounted for almost 90% of the electrocardiographic information measured on the body surface with the D/Q lead system.


Interaction of oscillators: effect of sinusoidal stretching of the sinoatrial node on nodal rhythm.

In this study of factors affecting and integrating activity of cardiac tissues, isolated strips of rabbit atria containing the sinoatrial node were subject to sinusoidal stretch. Effects on electrical discharge rates and rhythm of this pacemaker were observed. Repetitive stretch of a few millimeters (20-40% increase in length) caused acceleration and produced oscillations in rate which were roughly proportional to frequency of stretching. At fast frequencies of stretching, the sinus rates oscillated faster but not synchronously. When rate of stretching approached the "resting" rate of the sinus, a "lock'in" occurred, in that sinus rate accelerated but oscillations disappeared. During stretching rates approximately twice resting rate, the oscillations again disappeared. At rates of stretching during which oscillations were synchronous, the time of pacemaker firing changed to coincide with the peak phase of the applied sinusoidal stretch, although several seconds were required for this adjustment. Interval histograms also showed that application of sinusoidal stretch imposed a greater regularity on pacemaker action. It was thus demonstrated that oscillatory processes of the cardiac pacemaker and an interaction of oscillators conceivably can occur in the heart. (Preliminary Publication, The Physiologist, 16 "3, 1973.)


Effects of prindolol on impulse formation and conduction in man.

Electrophysiologic changes produced by intravenous administration of 0.6 mg Prindolol were studied in 16 subjects with normal impulse formation and conduction. The most important changes were: sinus bradycardia, prolongation of atrial refractory periods, depression of intranodal conduction and prolongation of A-V node refractory periods. Sinus node recovery time was unchanged, and sinoatrial conduction time was only slightly increased. Intraventricular conduction time and the refractory period of the His-Purkinje system and of the bundle branches were unchanged.


Mechanism of atrioventricular conduction: study on an analogue.

A simple analogue of the heart, consisting of neon relaxation oscillators, is presented. The analogue may display several disturbances of the A-V conduction, like normal atrioventricular (A-V) conduction, first-degree heart block, Wenckebach periods, Mobitz II type block, supernormal conduction, complete A-V block, the phenomenon of accrochage in complete A-V block and the absolutely arrhythmic response of the ventricles to a very high atrial rate. The analogue was constructed in the simplest possible way, i.e., using the least possible number of variables. The striking similarities between the properties of relaxation oscillators and cardiac pacemakers on the one hand and between the behavior of the analogue and manifestations of the A-V conduction abnormalities on the other might possibly permit a hypothesis about the mechanism of A-V conduction abnormalities based on the analogue. This mechanism is discussed in detail.


Case studies: Simultaneous intermittent intraatrial and intraventricular conduction defects mimicking trifascicular conduction delay.

Both intermittent rate related left bundle branch block and intermittent rate related trifascicular conduction delay (left bundle branch block with marked H-V interval prolongation) have been previously described. However intermittent rate related intraatrial block with left bundle branch block has not. No only does the case presented herein reveal intermittent rate related intraatrial block with left bundle branch block, but also PR prolongation secondary to the intraatrial block. This combination mimicked intermittent trifascicular conduction delay. Electrophysiological testing allowed differentiation of this pseudotrifascicular defect from true trifascicular conduction delay.


Bradycardia-related (phase 4) left anterior hemiblock.

A case is presented in which left anterior hemiblock (LAH) appeared transiently after the pause terminating atrial pacing, after atrial premature beats and during the slowing of sinus rhythm induced by carotid sinus massage. The transient LAH is attributed to phase-4 block, and is reported in order to add weight to the hypothesis that phase-4 block is a significant factor in the genesis of discrete conduction blocks in the human heart.


Evolutionary changes in the electrocardiogram of severe progressive hypothermia.

A patient is reported who developed progressive hypothermia during therapy for adult respiratory distress syndrome. Electrocardiographic changes (sinus bradycardia, prolonged PR interval, prolonged QTc interval, "Osborn waves") were documented and correlated with body temperature. The significance of these changes is discussed and the relationship between the degree of hypothermia and the presence of "Osborn waves" is noted.


Demonstration of bidirectional dual A-V nodal pathways in the same patient.

In a patient with documented paroxysmal junctional tachycardia (PJT) electrophysiologic studies were performed using an extrastimulus technique. At an A1-A2 interval of 360 msec, atrial extrastimulus revealed sudden prolongation of an A2-H2 interval from 370 to 540 msec and PJT ensued. This finding was consistent with antegrade dual A-V nodal pathways. On the other hand, at a V1-V2 interval of 540 msec, ventricular estrastimulus showed a jump in ventriculo-atrial (V-A) conduction time with evidence of delay in the A-V node from 285 to 565 msec and a ventricular echo followed. This finding was consistent with retrograde dual A-V nodal pathways. Mechanisms of bidirectional dual A-V nodal pathways are discussed.


Annotation: Numerical calculation of the mean electrical axis of electrocardiographic deflections.

Formulas are presented for numerical calculation of magnitude and direction of the mean electrical axis of electrocardiographic deflections suitable for use with hand calculators and electronic digital computers.


The electrocardiographic image surface revisited.

An image torso may be viewed as a one-to-one transform of a physical volume conductor to a geometric form which defines both the axis and sensitivity of any electrocardiographic connection. In this report, the image surfaces of laminar, spherical, rectangular and humanoid physical torsos are explored theoretically and experimentally. All proved to be rounded or spherical in form despite the marked differences in the configuration of the physical conductor. Moderate degrees of dipole eccentricity induced only small departures from this basic circular pattern. Introduction of phase inhomogeneity, however, resulted in more striking deviations from roundness.


Physiopathological and diagnostic hypotheses in peripheral block.

Delays and conduction blocks may occur in Purkinje fibers, junctions and muscular cells. Since such blocks may take place everywhere in the ventricles and not only in the free walls, we prefer to use the term peripheral instead of parietal block. The electrophysiologic problems connected with such blocks are discussed. The localization of the ventricle affected by the block is usually simple using VCG recording and is based on the orientation of terminal vectors. It is more difficult to recognize the ventricular walls affected by the block, the intraparietal localization and the source of the block: Purkinje fibers, junctions or muscular fibers. We maintain the concept that peripheral blocks alter not only the terminal phases of ventricular depolarization, but sometimes also the initial ones, in that the Purkinje-junction-muscular fibers system can be damaged in the septum with the major conduction pathways remaining intact. Several discrepancies found between the prescence of electric patterns of septal necrosis and autopsy data may be explained by peripheral blocks localized in the left septum.


The clinical significance of atrial pacing-induced Mobitz I atrioventricular block in patients with coronary artery disease.

Two hundred consecutive patients with a history of chest pain undergoing cardiac catheterization, coronary angiography and atrial pacing have been analyzed to assess the clinical significance of Mobitz I atrioventricular (A-V) block developing with the stress of atrial pacing. Of 160 patients with coronary artery disease, 26 (16%) developed Mobitz I A-V block at rates below 140 beats/min. Eighteen of these 26 patients (69%) had electrocardiographic evidence of old inferior wall myocardial infarction, compared to only 34 of the remaining 134 patients (29%) (P = less than 0.01). During the mean follow-up of 29.5 months (range 18-50 months) none of the 26 patients has developed spontaneous second or third degree A-V block. Twenty-three of the 26 patients had an exercise test within one week of the pacing study. No A-V block was noticed during or immediately following exercise, although the mean heart rate attained during exercise was higher than the mean pacing rate at which the A-V block occurred (136 +/- 5 vs 122 +/- 3, P = less than 0.01). Eighteen of these 23 achieved heart rates equal to or higher than the pacing rate at which A-V block developed. Nineteen (83%) shortened their P-R interval during exercise and 4 (17%) did not change the P-R length. Although atrial pacing-induced Mobitz I A-V block may indicate a latent A-V nodal conduction abnormality in some cases, its demonstration does not necessarily predict the occurrence of spontaneous advanced A-V block. Exercise should not be restricted in these patients on the basis of such a finding during a pacing study.


Studies on ovine placental lactogen secretion by homologous radioimmunoassay.

The concentrations of ovine placental lactogen (oPL) have been determined in maternal plasma, umbilical cord plasma, and allantoic fluid by an homologous radioimmunoassay for oPL which is sensitive to 0-1 ng hormone. Ovine placental lactogen was first detected in maternal plasma at 41-50 days of gestation and reached a peak concentration of 2547 +/- 226 (S.E.M.) ng/ml at 121-130 days in ewes with singleton gestations. The oPL concentration in cord plasma was 336-4 +/- 60-3 ng/ml and in allantoic fluid was 29-6 +/- 6-4 ng/ml. After surgical removal of the placenta, oPL disappeared from maternal plasma with a half-life of 29-1 +/- 1-3 min.


Onset of oestrogen-induced prolactin secretion and DNA synthesis by the rat pituitary gland.

The times of onset of oestrogen-induced prolactin secretion and DNA synthesis were studied in the pituitary gland of the male rat. At intervals from 3 to 96 h after injection of 10 mg diethylstilboestrol dipropionate, serum and pituitary prolactin concentrations were measured by radioimmunoassay and pituitary DNA synthesis by incorporation of [3H]-thymidine in vitro. Serum prolactin was raised significantly from 6 h onwards and DNA synthesis was increased from 30 h onwards. Pituitary prolactin concentration began to increase at 30 h. Significant correlations were obtained between serum prolactin and DNA synthesis from 24 to 72 h but not during the period of prolactin secretion from 6 to 24 h.


Role of vasopressin in the mitotic response of rat bone marrow cells to haemorrhage.

Two days after a severe haemorrhage plasma calcium concentrations and bone marrow mitotic activity in rats were significantly increased and so remained for a further 5-6 days until the haematocrit had returned to normal. The first 48 h after bleeding were characterized by hypocalcaemia. During this phase two significant peaks in mitotic activity were observed at 4 and 18 h after haemorrhage. The mitotic surge 4 h after bleeding was still present in adrenalectomized and parathyroidectomized animals but in rats which were either hypophysectomized or had congenital diabetes insipidus this mitotic response was absent. Vasopressin was shown to stimulate bone marrow mitotic activity both in vivo and in vitro whereas angiotensin, aldosterone and erythropoietin had no rapid, direct mitogenic action on these cells. This novel hypophysial-bone marrow system suggests that vasopressin may assist in post-haemorrhagic recovery in blood cell numbers in the circulation.


States of activation of chick kidney adenylate cyclase induced by parathyroid hormone and guanyl nucleotides.

Several aspects of the activation of adenylate cyclase by guanosine 5'-triphosphate (GTP), 5'-guanylylimidodiphosphate (Gpp(NH)p) and bovine parathyroid hormone (bPTH) have been studied in chick kidney plasma membrane preparations. GTP (10(-4) mol/l), Gpp(NH)p (10(-4) mol/l) and bPTH (10 i.u./ml) activated adenylate cyclase without any significant time lag. However a 2 min delay was observed before the activity of the enzyme increased after the addition of bPTH (-6 leads to +34) to incubations. The early (0-3 min) effects of GTP and Gpp(NH)p upon chick kidney adenylate cyclase activity were antagonized by the addition of the alternative guanyl nucleotide. After 5 min of incubation with kidney plasma membranes, Gpp(NH)p induced a stable state of activation of adenylate cyclase which was not reversible by subsequent addition of GTP. GTP did not induce an irreversible state of enzyme activation. In pre-incubation studies, GTP did not produce a persistent enzyme activation and did not modify the effect of Gpp(NH)p added subsequently at the incubation stage. Gpp(NH)p produced a stable state of activation of adenylate cyclase which was not inhibited by addition of GTP at the incubation stage. Bovine PTH (2-34) inhibited the effect of bPTH upon adenylate cyclase activity when the native hormone (10 i.u./ml) had been incubated with plasma membranes for up to 8 min before addition of the analogue (5 mug/ml). Incubation of plasma membranes with bPTH (2-34) for as little as 10 s prevented activation of adenylate cyclase by subsequent addition of bPTH. This pattern was confirmed in pre-incubation studies. After pre-incubation of kidney membranes with bPTH and bPTH (2-34), followed by washing, an acid extract of the membranes contained immunoreactive bPTH. Gpp(NH)p produced a greater increase in adenylate cyclase activity in membranes pre-incubated with bPTH or bPTH (2-34) than in membranes pre-incubated with buffer alone, suggesting that the hormone and analogue facilitated the interaction of Gpp(NH)p with adenylate cyclase.


Appearance of peroxidase reactivity within the rough endoplasmic reticulum of blood monocytes after surface adherence.

Rabbit blood monocytes, which contain no cytochemically demonstrable peroxidase, develop peroxidatic activity in the RER and perinuclear cisternae within 2 h after adherence to serum- or fibrin-coated surfaces. A similar reactivity appears in surface-adherent human and rat blood monocytes. In both localization and characteristics, this enzyme reactivity in monocytes resembles that normally seen in the resident peritoneal macrophages of the rabbit, as well as in several types of tissue macrophages in other species. Thus this observation supports the concept, presently based on the kinetic data of other investigators, that blood monocytes are the precursors of such cells. Moreover, the appearance of new enzyme activity after adherence may reflect alterations in cellular metabolism resulting from plasma membrane:surface interactions.


Antibody-dependent cell-mediated cytotoxicity in the Moloney sarcoma virus system: differential activity of IgG and IgM with different subpopulations of lymphocytes.

Antibody-dependent cell-mediated cytotoxicity in the Moloney sarcoma virus (MSV) system was evaluated in terms of the differential ability of IgG and IgM from MSV regressor animals to induce cytotoxicity by lymphocytes from lymph node, spleen, and thymus. The cell-mediated cytotoxicity induced by both IgM and IgG was specific for target possessing the appropriate virally determined cell surface antigen(s). IgM induced cytotoxicity by lymphocytes from all the organs tested. However, differences in magnitude and efficiency were revealed. Lymph node cells and thymocytes were most efficient against IgM-coated target cells. Against IgG-sensitized target cells, spleen and lymph node cells were about equally active, but thymocytes were inactive. Cortisone treatment of the donors of effector cells revealed that the cortisone resistant subpopulation of thymocytes, 2 days after cortisone injection, exhibited an increased cytotoxicity against target cells treated with unfractionated antiserum and its IgM fraction. This subpopulation of thymocytes was also cytotoxic against IgG-coated target cells. At 12 days after cortisone injection, the repopulated thymus showed little change in activity, compared to control thymus, against antibody-coated target cells.


A comparative study of the effects of certain halogenated benzimidazole ribosides on RNA synthesis, cell proliferation, and interferon production.

5-(or 6-)Bromo-4,5-(or 5,7-)dichloro-1-beta-D-ribofuranosylbenzimidazole, 5,6-dibromo-1-beta-D-ribofuranosylbenzimidazole, and 5,6-dichloro-1-beta-D-ribofuranosylbenzimidazole show closely similar structure-activity relationships with respect to inhibition of cellular RNA synthesis, cellular proliferation, and influenza virus multiplication, and also with respect to enhancement of interferon production. The activities ofth ese compounds are ranked 20:2.5:1. The log dose-response curves constructed for inhibiton of FS-4 cell RNA synthesis show similar slopes and a leveling off at 60-70% inhibition of RNA synthesis at the highest concentrations of each compound tested. This evidence suggests that these three derivatives act through the same mechanism. It has been shown previously that the dichloro compound selectively inhibits nuclear heterogenous RNA and messenger RNA synthesis. The concentrations of the benzimidazole ribosides at which the rate of proliferation of human fibroblasts (FS-4) is reduced by 50% are as follows: monobromodichloro: 1.7 muM (0.68 mug/ml); dibromo: 12 muM (4.9 mug/ml); dichloro: 38 muM (12 mug/ml). All compounds reduce the exponential rate of cell proliferation in a dose-dependent manner. The inhibition of cell growth is reversible upon removal of the compounds from the medium. Protocols based on any one of the three halobenzimidazole ribosides give interferon yields from poly(I)-poly(C)-induced FS-4 cells which are comparable to the high yields obtained with the conventional cycloheximide-actinomycin D protocol. The enhancement of interferon yield depends on blocking of the synthesis of RNA which is involved in the shutoff of interferon production.


The role of membrane receptors for C3b and C3d in phagocytosis.

In this paper we re-examine the roles of particle-bound IgG and C3 in phagocytosis of sheep erythrocytes (E) by monolayers of purified human monocytes and polymorphonuclear leukocytes (PMN). We conclude that two fragments of the C3 molecule, that is, C3b and C3d, can function as opsonins if the phagocyte has the appropriate membrane receptors. Monocytes, that bind both C3b and C3d, respond to both as opsonins. PMN, which do not bind C3d, respond only to particles opsonized with C3b. C3 and IgG have separate roles in phagocytosis. IgG, through its Fc fragment, directly stimulates particle ingestion, but is relatively inefficient at inducing particle binding. On the other hand, C3 primarily mediates the binding of the particle via complement receptors. A marked synergy exists between C3 and IgG in inducing phagocytosis. Thus, opsonization of the particle with C3 can be a necessary condition for particle ingestion, although by itself C3 does not trigger phagocytosis. The opsonic effect of C3 can be mimicked by a variety of nonimmunologic agents which enhance binding of the particle to the phagocyte without directly stimulating ingestion. The contact-inducing agents used include centrifugation of particle and phagocyte, high molecular weight dextran, protamine, and treatment of E with neuraminidase. These results suggest that the role of C3 in opsonization is mainly or exclusively one of establishing contact between particle and phagocyte.


Macrophage plasminogen activator: induction by products of activated lymphoid cells.

Macrophages obtained from the peritoneal cavity of untreated mice do not ordinarily synthesize plasminogen activator. However, induction of enzyme synthesis and secretion occurs when such macrophages are cultured in presence of conditioned medium from Con A-stimulated spleen cells. Plasminogen activator production by macrophages from endotoxin or thioglycollate medium-injected mice, which spontaneously secrete substantial amounts of the enzyme, is also markedly increased in presence of such conditioned medium. These results suggest that macrophage plasminogen activatory production may be regulated in part by lymphocytes. They provide further evidence to link macrophage plasminogen activator with cell migration and inflammation, and also support the view that in macrophages, as in certain other cell types, synthesis and secretion of this enzyme are under hormonal control.


Isolation by cell-column chromatography of immunoglobulins specific for cell surface carbohydrates.

A new method of affinity chromatography using glutaraldehyde-fixed cells immobilized on Sephadex beads has been used to isolate immunoglobulins (Ig's) specific for cell surface glycoproteins. Ig's that specifically bound and agglutinated the same cells as those originally fixed on the columns were isolated from nonimmune sera of various species. Periodate treatment of the cell-columns and the free cells destroyed their ability to bind the Ig's, and the binding of the Ig's to untreated cells was inhibited by monosaccharides such as D-galactose and sialic acid. The binding of antibodies directed against cell surfaces obtained by immunizing animals with the same mouse tumor cell lines used on the columns (P388 and EL4) was not inhibited by various saccharides. Surface glycoproteins obtained from the mouse tumor cells by immunoprecipitation with the column-isolated Ig's yielded specific electrophoretic patterns that differed from those obtained using Ig's from the sera of rabbits immunized with the tumor cells. The data suggest that the Ig's isolated by cell-column chromatography were directed against carbohydrates, probably those in terminal positions of the polysaccharide portions of the tumor cell surface glycoproteins. Column-isolated Ig's specific for carbohydrates were also useful in studies of cell interactions in nonmammalian systems including Dictyostelium discoideum and Saccharomyces cerevisiae. The cell-column method appears to be adaptable to the isolation of a variety of molecules in addition to antibodies.


Histocompatibility antigens controlled by the I region of the murine H-2 complex. II. K/D region compatibility is not required for I-region cell-mediated lymphocytotoxicity.

In the cell-mediated lymphocytotoxicity assay, A.TH effector cells sensitized to A.TL lymphocytes lyse not only A.B10.AQR effector cells lyse B10.BR and B10.BYR target cells in addition to B10.AQR cells. These findings indicate that for CML to occur across the IA region barrier, compatibility at K or D regions is not required.


Developing an objective based curriculum for a family practice residency.

Although there is a preponderance of articles on behavioral objectives in education, few address the process by which objectives are developed and agreed upon in a residency training program. The process by which objectives are developed is critical to their eventual implementation. The development and implementation of objectives are particular concerns in family practice residencies which, because of their broad based content, are uniquely dependent on other departments for portions of the residency training program. This paper describes an approach for developing curriculum objectives in a Family Practice Residency Program which emphasized the personal involvement of individuals who would be instrumental in implementing the curriculum, such as program directors, coordinators of "other" specialty rotations,and resident representatives. This approach, although time-consuming, resulted in well-formulated objectives that could be implemented. Further, this approach allowed for intensive interaction among various faculty members representing many fields, resulting in increased mutual understanding and appreciation.


Profile of full-time family practice educators.

This paper presents the first study of characteristics of full-time family practice educators in the United States. The majority of family practice educators entered the teaching field within the 1972 to 1975 time period, having done so after a period of ten to 20 years in the private practice of family medicine. Group practice (124) marginally outnumbered solo practice (102) with internal medicine and pediatrics representing the greatest percentage of patient care in all previous practice settings. A large majority of family practice educators have had two years of graduate training and are diplomates of the American Board of Family Practice. The respondents expressed a high degree of personal and professional satisfaction in their present positions, but many desired continuation of personal patient contact.