Hydrogen-fluorine exchange in NaBH4-NaBF4.

Hydrogen-fluorine exchange in the NaBH4-NaBF4 system is investigated using a range of experimental methods combined with DFT calculations and a possible mechanism for the reactions is proposed. Fluorine substitution is observed using in situ synchrotron radiation powder X-ray diffraction (SR-PXD) as a new Rock salt type compound with idealized composition NaBF2H2 in the temperature range T = 200 to 215 °C. Combined use of solid-state (19)F MAS NMR, FT-IR and DFT calculations supports the formation of a BF2H2(-) complex ion, reproducing the observation of a (19)F chemical shift at -144.

IgM antibody to hepatitis B core antigen in children with chronic type B hepatitis.

IgM antibody to hepatitis B core antigen (anti-HBc IgM) was investigated by an antibody-capture radioimmunoassay (serum dilution 1:4000) in serum samples from 31 untreated children with chronic hepatitis B who were followed prospectively for 1-7 years. At the start, all patients were positive for hepatitis B e antigen (HBeAg), and anti-HBc IgM was detected in 23 cases, including 15 out of 16 with chronic active hepatitis and 7 out of 14 with chronic persistent hepatitis. A significant positive correlation was found between anti-HBc IgM levels and severity of liver damage (P less than 0.

Prognosis of chronic hepatitis B transmitted from HBsAg positive mothers.

Nine children born to HBsAg positive mothers, who became chronic HBsAg carriers with associated liver disease, were followed for five to 10 years. Five children with active hepatitis or active cirrhosis at presentation achieved complete remission within six years, while three HBeAg positive patients with minimal histological lesions remained unchanged.

A 7 year survey of acute hepatitis type B.

Epidemiological and clinical features of acute symptomatic hepatitis type B were evaluated in 51 otherwise healthy children and in 13 children receiving immunosuppressive treatment for leukaemia and malignancy, who were admitted to hospital with acute hepatitis B surface antigen (HBsAg) positive hepatitis during a period of 7 years. Blood transfusions, or intimate contacts with asymptomatic HBsAg carriers or with contaminated material during repeated admission to hospital were the possible sources of infection in the immunosuppressed patients, whereas percutaneous exposure was identified as the source in a minority of non-immunosuppressed patients. Features of the acute phase of the illness differed little between the two groups of patients (acute liver failure developed in one patient with leukaemia and in two untreated children).