The discovery of thiamethoxam: a second-generation neonicotinoid.

Neonicotinoids represent a novel and distinct chemical class of insecticides with remarkable chemical and biological properties. In 1985, a research programme was started in this field, in which novel nitroimino heterocycles were designed, prepared and assayed for insecticidal activity. The methodology for the synthesis of 2-nitroimino-hexahydro-1,3,5-triazines, 4-nitroimino-1,3,5-oxadiazinanes and 4-nitroimino-1,3,5-thiadiazinanes is outlined.

Variability of the Hepatitis B Surface Protein in HBV-Infected Liver Transplant Recipients.

Variations in the major surface proteins (HBsAg) of hepatitis B virus (HBV) have been implicated in the high rate of reinfection in HBV-infected recipients of orthotopic liver transplantations (OLT). Sera from 6 OLT patients positive for HBsAg and from 3 recipients negative for it prior to transplantation were analyzed over several years, and 39 HBsAg sequences were compared. Despite anti-HBs immunoprophylaxis resulting in the disappearance of HBsAg, HBV DNA was detectable by a sensitive nested PCR in almost all sera.

Individuals with antibodies against hepatitis B core antigen as the only serological marker for hepatitis B infection: high percentage of carriers of hepatitis B and C virus.

Background/aims: Several reports have unequivocally demonstrated that some individuals with antibodies against hepatitis B core antigen as the only serological marker for hepatitis B infection are chronic carriers of the hepatitis B virus. Nevertheless, conflicting data exist about the frequency of this phenomenon; its cause is unknown.

Methods: In a prospective study we tested individuals who were positive for anti-HBc alone for HBV-DNA as well as for coexisting infections with human immunodeficiency virus and hepatitis C virus.

Detection by PCR of human polyomaviruses BK and JC in immunocompromised individuals and partial sequencing of control regions.

Immunocompromised individuals were tested for the presence of the human polyomaviruses JC (JCV) and BK (BKV) by the polymerase chain reaction (PCR). The use of appropriate primers in a nested PCR allowed the detection of both viruses simultaneously. Viruses were differentiated by restriction fragment length analysis of amplified DNA fragments.

The Sukhumi primate monkey model for viral lymphomogenesis: high incidence of lymphomas with presence of STLV-I and EBV-like virus.

T-cell leukemia virus-like proviral sequences (STLV-I) as well as EBV-like sequences were detected in PBLs and tissues of non-human primates (Papio hamadryas baboons, Green monkeys and Macaca arctoides; Sukhumi Primate Center/Georgia) by PCR. Surprisingly, two different types of STLV-I within Papio hamadryas baboons were found. One of its represents the baboon prototype STLV-I-Su described earlier, present in lymphomatous baboons from the "high-lymphoma stock", which shows about 83% homology to HTLV-I and 85% to STLV-I in the env and tax genes.