Gonadotrophin-releasing hormone agonist dose-dependency of pituitary desensitization during controlled ovarian hyperstimulation in IVF

The aim of this study was to find the minimal effective daily s.c. dose of the gonadotrophin-releasing hormone (GnRH) agonist, triptorelin acetate, that suppresses the GnRH-induced release of luteinizing hormone (LH) at time of human chorionic gonadotrophin (HCG) injection and thereby prevents spontaneous LH surges during in-vitro fertilization (IVF) stimulation cycles. Therefore, a double-blind, prospective and randomized titration study was performed. A total of 48 IVF patients were divided into four groups of 12 patients. Each group received a different dose of triptorelin acetate, namely 5, 15, 50 or 100 microg s.c. daily. Standard ovarian stimulation was carried out using urinary follicle stimulating hormone (FSH) preparations. A 500 microg GnRH test was performed 90 min before the HCG injection in order to measure the degree of pituitary desensitization. Spontaneous LH surges were not detected in any of the groups, although three patients in the 5 microg group had ovulated at the time of ovum retrieval. The pituitary LH response to the GnRH test at time of HCG, expressed as area under the curve (AUC), appeared to be dose-dependent. Thus, a daily s.c. dose of 100 microg triptorelin acetate appears to be too high, since adequate desensitization of the pituitary (i.e. no spontaneous LH surge) can be achieved with doses as low as 15 and 50 microg.      

Recombinant Helicobacter bilis Protein P167 for Mouse Serodiagnosis in a Multiplex Microbead Assay

Infection of mice with Helicobacter bilis is widespread in research and commercial mouse colonies. Therefore, sensitive, specific, and high-throughput assays are needed for rapid and accurate testing of mice in large numbers. This report describes a novel multiplex assay, based on fluorescent microbeads, for serodetection of H. bilis infection. The assay requires only a few microliters of serum to perform and is amenable to a high-throughput format. Individual microbead sets were conjugated to purified, H. bilis-specific, recombinant proteins P167C and P167D and bacterial membrane extracts from H. bilis and Helicobacter hepaticus. For detecting H. bilis infection in the microbead multiplex assay, P167C and P167D provided significantly higher sensitivities (94 and 100%, respectively) and specificities (100 and 95%, respectively) than membrane extract (78% sensitivity and 65% specificity). Microbead multiplex assay results were validated by enzyme-linked immunosorbent assay. Purified recombinant proteins showed low batch-to-batch variation; this feature allows for ease of quality control, assay robustness, and affordability. Thus, recombinant antigens are highly suitable in the multiplex microbead assay format for serodetection of H. bilis infection.     

Scanning electron microscopic examination of human pulonary capillaries using a latex replication method

The human pulmonary microvasculature from the apical bronchopulomanary segment was studied by scanning electron microscopy using latex relpicas. The latex replica was composed of a blend of vinyl chloride latexes using a plasticized vinyl chloride copolymer with a vinyl chloride copolymer. The polymerized latex produced a cast of the pulmonary arterial vascular tree, including the capillary patterns, which freely anastomose, thereby draining blood into pulmonary veinules and veins. The latex was injected via a gravity flow system modified from its earlier application in Guinea pig lungs. The apparently normal lungs from two recently deceased humans (dead for 5-6 hours and held in refrigeration) were perfused with heparinized Ringer's solution and subsequently injected with latex. The resulting latex casts of the capillaries revealed a three-dimensional network arranged in irregular vascular rings or ovals. This patterns was most conspicuous in deep and intermediate bronchopulmonary segmental areas. However, the subpleural capillaries produced casts that often terminated blindly, as observed with stereo SEM, suggesting that these vessels may tend to form thrombi more easily as compared with capillaries from other regions of the lung alveoli. The pulmonary arteriolar replicas contained indentations representing endothelial cell nuclei, and the capillary replicas projected oval evaginations that may represent discrete loci or capillary mural attenuations.     

Durability of sodium sulfate-treated polylysine-alginate microcapsules

Chelated hollow microcapsules are unstable under in vitro conditions because of their hygroscopic nature. Nongel inducing cations, such as Na+, stabilize the outer membrane of the alginate-polylysine-alginate microcapsules leading to more stable beads. We made different batches of empty capsules with a mean +/- SEM diameter of 607+/-11 microns, and found that within 1 week of incubating these capsules in normal saline at 37 degrees C, they increased to 718+/-10 microns (p < 0.05, n = 5). In initial experiments, we made different batches of capsules and divided them into two groups. One group was left untreated (control) whereas the other was treated with 6 mM Na2SO4 for 30 min, before incubation in saline at 37 degrees C. Control capsules increased in weight and size, before beginning to melt in less than 1 week. In contrast, treated capsules rapidly lost weight and remained intact during 1 month of follow-up. In perifusion experiments, we found no deleterious effect of sodium sulfate treatment on the function of islets enclosed in the capsules.     

Antibody and cytokine responses to the cilium-associated respiratory bacillus in BALB/c and C57BL/6 mice

The cilium-associated respiratory (CAR) bacillus is a gram-negative, gliding bacterium that causes persistent respiratory tract infections in rodents despite histologic and serologic evidence of a marked immune response. To assess humoral immunity and cytokine responses in CAR bacillus disease, 6-week-old female BALB/c and C57BL/6 mice were inoculated intratracheally with 10(5) CAR bacillus organisms. CAR bacillus-specific serum immunoglobulins (immunoglobulin M [IgM], IgG1, IgG2a, IgG2b, IgG3, and IgA) and local pulmonary cytokines (tumor necrosis factor alpha [TNF-alpha], gamma interferon [IFN-gamma], and interleukin-4 [IL-4]) were evaluated by enzyme-linked immunosorbent assay every 7 days for 49 days. BALB/c mice developed CAR bacillus-induced lesions early in the course of disease that became more severe with time. Correlating with increasing disease severity, BALB/c mice had elevations in all antibody isotypes tested, and elevations in pulmonary TNF-alpha, IFN-gamma, and IL-4. C57BL/6 mice developed mild lesions with mild increases in serum IgM, IgG1, IgG2b, and IgG3 levels and minimally detectable IgG2a and IgA. Cytokine perturbations were not detected in C57BL/6 mice. The persistence of infection in BALB/c mice with vigorous serum antibody responses and increased IFN-gamma and IL-4 responses suggests that humoral immunity and T-cell responses are ineffective at preventing CAR bacillus disease. Furthermore, the lackluster antibody responses and undetectable cytokine responses in C57BL/6 mice suggest that humoral immunity and T-cell responses are not critical in resistance to CAR bacillus-induced disease.     

Effects of hemipancreatectomy on insulin secretion and glucose tolerance in healthy humans

Pancreatic tissue obtained by hemipancreatectomy from healthy living related donors has been transplanted into recipients with Type I diabetes mellitus. To determine the metabolic consequences of this procedure for the donors, we carried out oral glucose-tolerance testing and 24-hour monitoring of serum glucose levels and urinary C-peptide excretion as a measure of insulin secretion in 28 donors, both before and one year after hemipancreatectomy. The mean fasting serum glucose level was significantly higher one year after the procedure (mean +/- SD, 5.4 +/- 0.9 vs. 4.9 +/- 0.5 mmol per liter; P less than 0.003), as was the serum glucose value two hours after the administration of glucose (8.7 +/- 2.9 vs. 6.5 +/- 1.0 mmol per liter; P less than 0.001). The fasting serum insulin level was significantly lower one year after hemipancreatectomy (33.0 +/- 21.6 vs. 38.4 +/- 21.6 pmol per liter; P less than 0.05), as was the area under the insulin curves during the oral glucose-tolerance test (52,554 +/- 22,320 vs. 76,230 +/- 33,354 pmol per liter per minute; P less than 0.04). The mean 24-hour serum glucose-profile value was higher at one year, and the 24-hour urinary C-peptide excretion was lower in the 17 donors who underwent these studies. Seven of the 28 donors had abnormal glucose tolerance one year after hemipancreatectomy; however, insulin secretion in these 7 donors was indistinguishable from that in the 21 donors who had normal glucose tolerance. All 28 donors had fasting serum glucose concentrations lower than 7.8 mmol per liter, and their mean 24-hour plasma glucose levels remained within the normal range. We conclude that in healthy donors hemipancreatectomy results in a deterioration of insulin secretion and glucose tolerance, as measured one year later. Further study is required to ascertain whether the development of clinical diabetes mellitus is a risk inherent in hemipancreatectomy.     

Testing the Habituation-Based Model of Exposures for Child and Adolescent Anxiety

Exposure has been identified as key to effective treatment of youth anxiety. However, the precise theoretical mechanisms of exposure are a matter of debate. Emotional processing theory emphasizes the need for fear activation during exposure and its habituation both within and across exposures. Despite the popularity of the theory to explain exposure, it has not been tested with anxious youth. To determine whether emotional processing theory parameters predict anxiety severity, coping abilities, and global functioning after cognitive-behavioral treatment. The present study examined 72 youth (M_age = 10.50 years; 45% female; 87.5% non-Hispanic Caucasian) diagnosed with an anxiety disorder and who received family or individual CBT. Three exposure habituation variables—initial fear activation (peak anxiety), within-session habituation, and between-session habituation—were assessed using Subjective Units of Distress and examined as predictors of outcome at posttreatment and at 1-year follow-up. Outcomes were measured using the Coping Questionnaire, Multidimensional Anxiety Scale for Children, Revised Children’s Manifest Anxiety Scale, Children’s Global Assessment Scale, and clinician severity ratings on the Anxiety Disorder Interview Schedule. Emotional processing theory variables did not predict any anxiety outcomes at posttreatment or follow-up with one exception: Initial fear activation predicted less anxiety at follow-up among youth without GAD. In addition, within- and between-session habituation were not associated with one another. Between-session habituation was not associated with initial fear activation. These findings suggest a limited role of habituation within cognitive-behavioral therapy for anxiety in youth. An alternative to emotional processing theory, inhibitory learning theory, is discussed.     

The brain and thymus have much in common: a functional analysis of their microenvironments

Research into the neural and immune systems has begun to converge. Since the first reports that interleukins play important roles in both systems and that lymphocytes secrete neuronal factors, scientists have been surprised by the ever-increasing list of interactions. Here, Rolf Mentlein and Marion Kendall examine the major supporting cells of the brain and thymus - astrocytes and thymic epithelial cells - the similar neuroectodermal origin of which could explain such fundamental analogies.