Dopaminergic agents differentially alter β-endorphin processing patterns in the rat pituitary neurointermediate lobe

We have established the content and molecular species of immunoreactive β-endorphin (ir-β-END) and immunoreactive N-acetyl-endorphin (ir-Nac-END) in rat neurointermediate lobe by specific radioimmunoassay (RIA) and high-performance liquid chromatography after chronic administration of dopamine (DA) agonists and antagonists. The DA agonist, bromocriptine, reduces tissue levels of all major immunoreactive species, in particular the C-terminally shortened N-acetylated forms. The DA antagonist, haloperidol, proportionally increases all immunoreactive forms, except Nac-β-END_1–27, thus altering the relative abundance of this species. These data indicate that DA is involved in the control of both tissue levels and processing of β-END-like peptides in the rat neurointermediate lobe.     

Effects of Local Immunization with Glucosyltransferase Fractions from Streptococcus mutans on Dental Caries in Hamsters Caused by Homologous and Heterologous Serotypes of Streptococcus mutans

Seven serotypes of Streptococcus mutans have been identified. The biochemical, genetic, and serological characteristics of these serotypes have indicated that certain serotypes are quite similar, whereas others are quite distinct. The effect of local immunization with glucosyltransferase (GTF) enzymes from serotypes a, c, or g on infection and disease caused by homologous or heterologous cariogenic S. mutans is reported. Organisms with either similar (a and g) or different (c and g) biochemical and serological characteristics were selected for heterologous challenge. NIH white hamsters were injected four times at weekly intervals with GTF prepared by 6 M guanidine-hydrochloride elution from water-insoluble glucan of serotypes a, c, or g, which resulted in enzyme (homologous) inhibitory activity in sera and salivas. After infection of GTF-immunized and sham-immunized groups of hamsters with cariogenic S. mutans of the same serotype as the injected antigen (homologous infection) or with S. mutans of a different serotype from the injected antigen (heterologous infection), the numbers of streptomycin-labeled S. mutans, caries, and lesions were determined. Immunization with GTF preparations from each of the three serotypes resulted in statistically significant reductions in the extent of infection and disease and number of lesions caused by infections with homologous cariogenic S. mutans. Statistically significant reductions in these three parameters were also observed in groups immunized with enzyme from serotype a (strain E49) and challenged with cariogenic serotype g (strain 6715) organisms; or immunized with enzyme from serotype c (strain Ingbritt) and challenged with cariogenic serotype g (strain 6715) organisms; or immunized with enzyme from serotype g (strain 6715) and challenged with cariogenic serotype c (strain Ingbritt) organisms. These studies suggest that soluble antigen preparations containing GTF from one serotype may elicit a protective immune response against infection with cariogenic S. mutans from many or possibly all serotypes.     

Regional quality control.

Methods of quality control of some major haematological techniques are described. These methods have been applied in haematology laboratories serving a population of 2 million using existing facilities for preparation and transport of the necessary materials.     

Evaluation of a clostridial alpha-toxin disk test for rapid presumptive identification of group B streptococci.

An alpha-toxin disk test is described in which group B streptococci completed the hemolysis of sheep erythrocytes partially lysed by the alpha-toxin of Clostridium perfringens. The test was performed satisfactorily on the sheep blood agar primary isolation plate, as well as on pure cultures. A total of 95% of strains of pure group B streptococci tested produced positive reactions within 5 h, and all were positive after overnight incubation, with patterns of synergistic hemolysis readily distinguishable from those seen with group A streptococci. The preparation of disks is well within the scope of most clinical laboratories.     

Energy Balance,Eating Disorder Risk,and Pathogenic Behaviors Among Athletic Trainers

ContextResearch exists on energy balances (EBs) and eating disorder (ED) risks in physically active populations and occupations by settings, but the EB and ED risk in athletic trainers (ATs) have not been investigated.ObjectiveTo assess ATs'' energy needs, including the macronutrient profile, and examine ED risk and pathogenic behavioral differences between sexes (men, women) and job statuses (part time or full time) and among settings (college or university, high school, nontraditional).DesignCross-sectional study.SettingFree living in job settings.Patients or Other ParticipantsAthletic trainers (n = 46; male part-time graduate assistant ATs = 12, male full-time ATs = 11, female part-time graduate assistant ATs = 11, female full-time ATs = 12) in the southeastern United States.Main Outcome Measure(s)Anthropometric measures (sex, age, height, weight, body composition), demographic characteristics (job status [full- or part-time AT], job setting [college/university, high school, nontraditional], years of AT experience, exercise background, alcohol use), resting metabolic rate, energy intake (EI), total daily energy expenditure (TDEE), EB, exercise energy expenditure, macronutrients (carbohydrates, protein, fats), the Eating Disorder Inventory-3, and the Eating Disorder Inventory-3 Symptom Checklist.ResultsThe majority of participants (84.8%, n = 39) had an ED risk, with 26.1% (n = 12) engaging in at least 1 pathogenic behavior, 50% (n = 23) in 2 pathogenic behaviors, and 10.8% (n = 5) in >2 pathogenic behaviors. Also, 82.6% of ATs (n = 38) presented in negative EB (EI < TDEE). Differences were found in resting metabolic rate for sex and job status (F_1,45 = 16.48, P = .001), EI (F_1,45 = 12.01, P = .001), TDEE (F_1,45 = 40.36, P < .001), and exercise energy expenditure (F_1,38 = 5.353, P = .026). No differences were present in EB for sex and job status (F_1,45 = 1.751, P = .193); χ² analysis revealed no significant relationship between ATs'' sex and EB (= 0.0, P = 1.00) and job status and EB ( = 2.42, P = .120). No significant relationship existed between Daily Reference Intakes recommendations for all macronutrients and sex or job status.ConclusionsThese athletic trainers experienced negative EB, similar to other professionals in high-demand occupations. Regardless of sex or job status, ATs had a high ED risk and participated in unhealthy pathogenic behaviors. The physical and mental concerns associated with these findings indicate a need for interventions targeted at ATs'' health behaviors.     

Cytokines, thyroid autoantibody synthesis and thyroid cell survival in culture

In autoimmune thyroid disease lymphoid cells infiltrating the thyroid gland occur in conspicuous aggregates or as a diffusely distributed population invading the thyroid follicles. Consequently cytokines secreted by activated T cells or macrophages could influence neighbouring thyroid cells as well as other lymphocytes. We have investigated this possibility using recombinant cytokines. Thyroid cell survival was assessed in terms of mitochondrial dehydrogenase activity in monolayers exposed to tumour necrosis factor-alpha (TNF-alpha), interferon-gamma (IFN-gamma), interleukin-1 (IL-1 alpha and beta) and interleukin-2 (IL-2) in the presence or absence of thyroid-stimulating hormone (TSH). Neither TNF-alpha nor IL-2 affected thyroid cell survival, IFN-gamma was usually inhibitory and IL-1 alpha slightly enhanced cell survival in some experiments. However, the effects were small and variable and were not enhanced by potentially synergistic combinations of cytokines, longer periods of exposure, or different culture conditions. In contrast, IFN-gamma, IL-2 and TNF-alpha inhibited the ability of thyroid lymphocytes from patients with Graves' disease and Hashimoto's thyroiditis to synthesize autoantibodies to thyroid peroxidase (TPO) and thyroglobulin (Tg). Comparison of lymphoid populations isolated by digestion and/or mechanical disaggregation indicated that a population of activated B cells, plasma cells and T cells, intimately associated with thyroid cells since they could only be extracted by digestion, was influenced by cytokines. Our studies suggest that in addition to its well-recognized ability to induce MHC class II antigens on thyroid cells, IFN-gamma may inhibit thyroid cell proliferation and TNF-alpha, IFN-gamma and IL-2 may down-regulate thyroid autoantibody synthesis.     

Influence of lectins, hexoses, and neuraminidase on the association of purified elementary bodies of Chlamydia trachomatis UW-31 with HeLa cells.

Using highly purified elementary bodies of Chlamydia trachomatis UW-31 (serotype K), we found that HeLa 229 monolayer cultures bound more 32P-labeled chlamydiae after pretreatment with the lectin wheat germ agglutinin. The lectin, on the other hand, inhibited competitively when chlamydial association was assayed in the presence of polycations. The two effects of wheat germ agglutinin were abolished when N-acetylneuraminic acid (NeuNAc)- or N-acetylglucosamine (GlcNAc)-preincubated wheat germ agglutinin was used. Brief exposure of HeLa cells to neuraminidase abolished the ability to bind the elementary bodies, whether or not polycations were present. Furthermore, at 5 degrees C but not at 37 degrees C, NeuNAc, GlcNAc and N-acetylgalactosamine inhibited chlamydial association only in the absence of the polycation DEAE-dextran. The results suggest that NeuNAc residues on the plasma membrane are the principal, but not the only, receptors for this strain of C. trachomatis.     

Finite element solution of steady state temperature distribution in the human torso

A finite element model of the steady state temperature distribution in the human torso is developed. The torso is approximated by a circular cylinder of core surrounded by a layer of muscle and insulating layers of fat and skin. The model is simplified by neglecting longitudinal heat flow. The region occupied by a circular cross-section of the torso is discretized into a mesh of triangles and the boundary of the torso, that is, the skin surface, is consequently approximated by a polygon. The elliptic partial differential equation governing the steady state temperature distribution, together with the associated boundary conditions, are expressed in equivalent variational form. Linear basis functions are used and the resulting integral is minimized over the region bounded by the approximating polygon. Results for two numerical experiments are determined by solving systems of linear equations.