Correlation of circulating betatrophin concentrations with insulin secretion capacity, evaluated by glucagon stimulation tests.

AIM: To investigate the relationship between plasma betatrophin concentrations and insulin secretion capacity in people with Type 2 diabetes. METHODS: Glucagon stimulation tests (1 mg) were performed in 70 people with Type 2 diabetes after an overnight fast. Plasma betatrophin concentrations were measured using an enzyme-linked immunosorbent assay. Insulin secretion capacity was evaluated by measuring increments of C-peptide concentration in response to glucagon stimulation, and creatinine clearance was determined by comparing creatinine concentrations in serum and 24-h urine samples. RESULTS: Plasma betatrophin concentrations were positively correlated with duration of Type 2 diabetes (r = 0.34, P = 0.003), and negatively correlated with increments of C-peptide concentration (r = 0.37, P = 0.001) and creatinine clearance (r = 0.37, P = 0.001). The correlation with increments of C-peptide concentration remained significant after adjustment for age and duration of Type 2 diabetes (r = 0.25, P = 0.037). Multivariate analysis identified age and increments of C-peptide concentration as independent factors associated with plasma betatrophin levels. CONCLUSION: Plasma betatrophin levels inversely correlate with insulin secretion capacity, suggesting that betatrophin levels are regulated by insulin secretion capacity in humans.

[Seroepidemiological study on the horizontal infection of HBV in healthy students].

In a seroepidemiological study of hepatitis B virus (HBV) over 7 years from 1982 to 1988, in a fixed population of 633 healthy students (15-20 years old), it was found that one HBV carrier who had adw subtype of HBV had also become sero-positive to r subtype, suggesting the superinfection with r subtype of HBV to the carrier. Then, some serological markers of HBV were further examined in the other 10 HBsAg positive carriers in the same population, and discussed the possibility of horizontal transmission of r subtype of HBV in the population. Of the 10 HBsAg positive carriers, 5 possessed adr subtype, 2 adwr, 2 adw, respectively, and the remaining one was not tested. Four of seven r subtype of HBsAg positive carriers exhibited pre-S2Ag and HBeAg activities which were considered as infectious markers. Epidemiological survey was carried on the four carriers with special reference to the possibility of the superinfection. As a result, it is still unclear the source of the superinfection, but at least, iatrogenically accidental transmission at the time of vaccination and contact infection in everyday life in school may be unlikely to attribute to the horizontal transmission.

[Isolation and analysis of amino acid sequence of V3 region of HIV-1 from patients with HIV-infection in Hiroshima].

Isolation of HIV-1 was tried in PBMCs separated from 27 blood samples which were sent to Hiroshima Prefectural Institute for Health & Environment Science for anti-HIV antibody-test. 18 samples were positive for HIV-isolation (4 samples were Rapid/High type, 12 samples were Slow/Low type and 2 samples were intermediate). Compared with clinical stages of patients, samples from patients in CDC-II were 64% (14/22) positive and those in CDC-IV were 100% (3/ 3) positive in HIV-isolation. Improvement of the methods is to be required to isolate HIV from the samples of patient in the latent phase. Removal of CD8 positive cells from PBMCs of patients did not affect the efficiency of HIV-isolation by our methods. Three parts in amino acid sequence of V3 region in proviruses were different between Rapid/High type isolated and Slow/Low type isolates. The difference of amino acid may be related to the different phenotypes of the two viruses.

Effect of heparin on hemagglutinin of herpes simplex virus type 1.

Heparin inhibited the hemagglutinin activity of herpes simplex virus (HSV) type 1. The minimal inhibitory concentration of heparin required to inhibit 8 hemagglutination (HA) U of HSV ranged from 0.005 to 0.01 U/ml. Mouse erythrocytes failed to combine with the HA inhibitory factor of heparin. On the other hand, mouse erythrocytes treated with heparinase had greatly reduced agglutinability by HSV. Virus-heparin complex formation was observed by sedimenting heparin with the virus particles.

Characteristics of IgA anti-HIV antibodies in plasma from patients with HIV infection.

The concentration of total IgA and the specificity and molecular size of IgA anti-human immunodeficiency virus (HIV) type-1 antibodies in plasma obtained from individuals at different stages of HIV infection were analyzed. The concentration of total IgA in the plasma was not decreased even in the late stage of HIV infection, in contrast with those of total IgG and IgM. The IgA anti-HIV antibodies differed to the IgG anti-HIV antibodies in their specificity as determined by Western blotting. The IgA antibodies mainly bind to Env glycoproteins. The IgA anti-HIV antibodies in plasma were detected between IgG and IgM by gel filtration, suggesting the presence of polymeric IgA anti-HIV antibodies. These results indicate that the production of non-specific IgA in plasma is enhanced by unknown mechanisms in every stages of HIV infection, and suggest that IgA anti-HIV antibodies in plasma which are possibly polymeric and have unique specificity may play an important role in HIV infection.

Installation of new damped cavities at the Photon Factory storage ring.

New damped cavities have been installed in the Photon Factory (PF) storage ring and successfully operated in the last scheduled user run of 1996. The new damped cavity is a simple single-cell cavity with somewhat large beam-duct holes. The part of the beam duct that is attached to the cavity is made of SiC, which works as a microwave absorber and damps the higher-order modes excited in the cavity. Because of its simple structure, the operation of the cavity is very stable and also a high power input of more than 150 kW is possible. No coupled-bunch instabilities due to the new cavity were observed during operation.

Reconstruction for the brilliance-upgrading project of the Photon Factory storage ring.

Reconstruction of the Photon Factory storage ring (PF ring; 2.5 GeV) is now in progress to provide very brilliant synchrotron radiation to users, i.e. the emittance is being reduced by a factor of five. Components, such as the quadrupole and sextupole magnets, vacuum chambers, beamlines and beam-position monitors, are being replaced by new ones in 16 normal-cell sections of the PF ring. The accelerating cavities, injection systems and control systems are also being replaced. Operation will commence when the improvements are completed on 1 October 1997.