Partial purification of parathyrin from the corpuscles of Stannius (PCS) of the eel (Anguilla anguilla, L.)

It has been previously shown that the eel corpuscles of Stannius (CS) synthesize and secrete a substance (PCS) which is functionally and immunologically related to the mammalian parathyrin family. Purification of PCS, including anion-exchange chromatography, ODS C-18 reverse-phase HPLC, and affinity chromatography, showed that a biologically active peak, eluted in 32% acetonitrile, contains a 32- to 34-kDa protein which is 600-fold more potent than the crude extract is a test involving the hypocalcemic response in the CS-deprived eel. Specific immunoprecipitation of protein encoded by mRNA extracted from eel CS indicates that a 45-kDa precursor is involved in PCS synthesis. The hypothetical significance of a "large" parathyrin-like molecule in fish is suggested in relation to what is known about mammalian parathyrin gene expression.     

Immune activation and oxidative damage in HIV-positive and HIV-negative adolescents

In a cross-sectional study involving subjects from the Reaching for Excellence in Adolescent Health cohort, we examined the associations between HIV status, disease severity, immune activation, and oxidative damage. Subjects (265 HIV-positive and 127 HIV-negative) were young (range: 14-23 years of age) and primarily female (75%) and black (67%). Many subjects, particularly female subjects, were overweight or obese. Relatively few HIV-positive subjects had advanced HIV disease (13%), and 54% were taking antiretroviral therapy (ART). The 2 markers of oxidative damage used in this study (plasma malondialdehyde and protein carbonyl concentrations) did not correlate with each other, and neither was higher in HIV-positive subjects than in HIV-negative controls. Increased oxidative damage was seen in association with male gender, cigarette smoking, marijuana use, immune activation (as indicated by activated CD8 T-cell counts and plasma C-reactive protein concentration), and use of ART, however. Plasma ceruloplasmin was associated with decreased oxidative damage in HIV-positive subjects, although this association was not seen in those taking ART.     

Characteristics of the 19S and 7S response to bacteriophage ΦX174 in the fowl

After intravenous injection of 10¹⁰ plaque forming particles of ØX174 bacteriophage into White Rock fowls, immune elimination began at 30 hours and viable phage was cleared from the circulation by 50–52 hours, the approximate time at which detectable antibody appeared. Little change was noted in the serum neutralizing activity in the interval from 44 to 217 days after injection, at which time the birds were reinjected with ØX174.

Sephadex Peak I (19S globulin) accounted for most of the early activity of the primary response. By Day 9 most of the activity had shifted to Peak II (7S globulin). In the secondary response, the shift had occurred by Day 4. Both 19S and 7S globulin fractions showed an increase in activity when compared to the same days of the primary response, but the 7S increase was proportionately greater.

All sera and serum fractions (whether 19S or 7S) were sensitive to reduction with 2-mercaptoethanol, but became, less sensitive during the course of immunization.

With regard to the production of 19S antibody, White Rock fowls showed a different response to the particulate antigen ØX174 compared with the response to injection of the soluble antigen, bovine serum albumin. There is evidence of immunological memory in the 19S response to ØX174.

     

Randomised controlled trial of pelvic floor muscle exercises and manometric biofeedback for erectile dysfunction.

BACKGROUND: The pelvic floor muscles are active in normal erectile function. Therefore, it was hypothesised that weak pelvic floor muscles could be a cause of erectile dysfunction.AIMS: To compare the efficacy of pelvic floor muscle exercises and manometric biofeedback with lifestyle changes for men with erectile dysfunction.Design of study: Randomised controlled trial.SETTING: The Somerset Nuffield Hospital, Taunton, United Kingdom.METHOD: Fifty-five men with erectile dysfunction (median age 59.2 years; range 22-78 years) were enrolled from a local urology clinic. Of these, 28 participants were randomised to an intervention group and engaged in pelvic floor exercises, as well as receiving biofeedback and suggestions for lifestyle changes. Twenty-seven controls were solely advised on lifestyle changes. Baseline, 3- and 6-month assessments were: erectile function domain of International Index of Erectile Function (IIEF), Partner's International Index of Erectile Function (PIIEF), Erectile Dysfunction-Effect on Quality of Life (ED-EQoL), anal manometry, digital anal measurements, and clinical assessment by an assessor blind to treatment allocation. After 3 months, the control group were transferred to the active arm.RESULTS: At 3 months, compared with controls, men in the intervention group showed significant mean increases in the erectile function domain of the IIEF (6.74 points, P = 0.004); anal pressure (44.16 cmH(2)O, P <0.001); and digital anal grades (1.5 grades, P <0.001). All showed further improvement in these outcomes at 6 months. Similar benefits were seen in men of the control arm after transfer to active treatment. A total of 22 (40.0%) participants attained normal function, 19 (34.5%) participants had improved erectile function, and 14 (25.5%) participants failed to improve.CONCLUSION: Pelvic floor muscle exercises and biofeedback are an effective treatment for men with erectile dysfunction.     

Increased seminal plasma lead levels adversely affect the fertility potential of sperm in IVF

BACKGROUND: Lead remains in high levels in the environment and is known to reduce fertility in animal models, but a direct link between lead exposures and human infertility has not yet been established. METHODS: In a prospective, double-blind study of the metal ion levels and sperm function, semen was obtained from partners of 140 consecutive women undergoing their first IVF cycle. Lead in seminal plasma was determined by atomic absorption spectroscopy. Motile sperm populations were assessed for surface receptors for mannose binding, and the ability to undergo premature ('spontaneous'), and free mannose-induced acrosome reactions. Fertile donor (n = 9) sperm were exposed to exogenous lead during capacitating incubations and then assessed for mannose receptor expression and acrosome loss. RESULTS: Lead levels were negatively correlated with IVF rates. Lead levels were negatively correlated to two of the three sperm function biomarkers (mannose receptors, mannose-induced acrosome reactions). Lead levels positively correlated with the spontaneous acrosome reaction. These findings were mimicked by in-vitro exposure of fertile donor sperm to lead. CONCLUSIONS: Multiple sperm parameters are affected as lead levels rise. Increased lead levels may contribute to the production of unexplained male infertility.     

Reproducibility of Immunological Tests Used To Assess Multiple Chemical Sensitivity Syndrome

Whether persons with multiple chemical sensitivity syndrome (MCS) have immunological abnormalities is unknown. To assess the reliability of selected immunological tests that have been hypothesized to be associated with MCS, replicate blood samples from 19 healthy volunteers, 15 persons diagnosed with MCS, and 11 persons diagnosed with autoimmune disease were analyzed in five laboratories for expression of four T-cell surface activation markers (CD25, CD26, CD38, and HLA-DR) and in four laboratories for autoantibodies (to smooth muscle, thyroid antigens, and myelin). For T-cell activation markers, the intralaboratory reproducibility was very good, with 90% of the replicates analyzed in the same laboratory differing by ≤3%. Interlaboratory differences were statistically significant for all T-cell subsets except CD4⁺ cells, ranging from minor to eightfold for CD25⁺ subsets. Within laboratories, the date of analysis was significantly associated with the values for all cellular activation markers. Although reproducibility of autoantibodies could not be precisely assessed due to the rarity of abnormal results, there were inconsistencies across laboratories. The effect of shipping on all measurements, while sometimes statistically significant, was very small. These results support the reliability of fresh and shipped samples for detecting large (but perhaps not small) differences between groups of donors in the T-cell subsets tested. When comparing markers that are not well standardized, it may be important to distribute samples from different study groups evenly over time.     

Comparison of Ashdown's medium, Burkholderia cepacia medium, and Burkholderia pseudomallei selective agar for clinical isolation of Burkholderia pseudomallei

Ashdown's medium, Burkholderia pseudomallei selective agar (BPSA), and a commercial Burkholderia cepacia medium were compared for their abilities to grow B. pseudomallei from 155 clinical specimens that proved positive for this organism. The sensitivity of each was equivalent; the selectivity of BPSA was lower than that of Ashdown's or B. cepacia medium.     

Effects of a Single Hit from the Alpha Hemolysin Produced by Escherichia coli on the Morphology of Sheep Erythrocytes

Scanning electron micrographs of sheep erythrocytes showed that attachment of the alpha hemolysin produced by Escherichia coli resulted in the formation of spherocytes, with 10 to 20 small projections spaced relatively evenly over the surface of the erythrocyte membrane. This shape change was induced within 5 min after treatment. If the hemolysin concentration was reduced to a level which would lyse only a fraction of the total erythrocytes, the affected cells were easily identified against a background of normal, unaffected cells. Unlike sodium lauryl sulfate and other amphipathic agents which enter cell membranes and increase their flexibility, low concentrations of hemolysin did not provide protection against hypotonic hemolysis. These findings indicate that the surface projections were not the result of membrane expansion caused by incorporation of hemolysin into the outer portion of the lipid bilayer. The ability of a given amount of hemolysin to release a constant amount of hemoglobin in the presence of increasing concentrations of red cells confirmed that a single hit is sufficient for lysis. These results suggest that a single hemolysin molecule can bind to a sheep erythrocyte and trigger internal reactions which result in the derangement of membrane integrity at multiple sites on the surface. Confirmation of one-hit kinetics indicates that measurement of E. coli hemolysin activity should be carried out at low ratios of hemolysin to erythrocyte to decrease the possibility of multiple hits on a single cell.