Inhibitory effect of glycyrrhizin on the phosphorylation and DNA-binding abilities of high mobility group proteins 1 and 2 in vitro.

The physiological correlation between glycyrrhizin (GL) and high mobility group proteins I and 2 (HMG1/2) and the inhibitory effect of GL on their phosphorylation by three protein kinases (CK-I, CK-II and PKC) were investigated biochemically in vitro. It was found that GL binds directly to HMG1/2, because (i) HMG1/2 have a high affinity with a GL-affinity column; and (ii) GL induces the conformational changes in HMG1/2. Both purified HMG1/2 functioned as phosphate acceptors for these two protein kinases (CK-I and PKC), but not phosphorylated by CK-II. Phosphorylation of HMG1/2 by two protein kinases (CK-I and PKC) was completely inhibited by a glycyrrhetinic acid derivative (oGA) at one-tenth the concentration of GL. Also, the DNA-binding abilities of HNG1/2 were reduced by GL in a dose-dependent manner. These results show that the binding of GL to HMG1/2 results in the inhibition of their physiological activities (DNA-binding ability and phosphorylation by PKC or CK-I) in vitro. The GL-induced inhibition of the physiological activities of HMG1/2 may be involved in the anti-inflammatory effect of GL in vivo.

Seroprevalence of HIV-1, HIV-2, and HIV-1 group O in Nigeria: evidence for a growing increase of HIV infection.

To determine current data on HIV infection and to further confirm the presence of HIV-1 group O infection in Nigeria, 2300 samples from five states were tested for the presence of HIV antibody. A convenience sampling was obtained from pregnant women, tuberculosis (TB) patients, commercial sex workers (CSWs), blood donors, patients with sexually transmitted diseases (STDs), patients with skin diseases, male clients of CSWs, outpatients suspected to have AIDS, truck drivers, and community dwellers. With the exception of pregnant women, the HIV prevalences in all these groups were high: 60.6% in CSWs, 16.2% in TB patients, 7.7% in blood donors in some states, and 16% in the rural area of Kano State. Male clients of CSWs, truck drivers, and STD patients had prevalences of 7.8%, 8.6%, and 21.2%, respectively. Regional differences in relation to HIV prevalences were observed; HIV-2 and most of the HIV-1/2 infections were found in the southern states of Nigeria. Higher HIV prevalences were observed in the north-northeast in pregnant women, TB patients, and CSWs, but for blood donors, higher rates were seen in the southeast-southwest. One asymptomatic 50-year-old woman, a community dweller in Kano, was identified to be HIV-1 group O-positive. Compared with data from national surveillance studies in 1991/1992 and 1993/1994, a substantial increase in HIV infection was observed. Our results show a growing incidence of HIV infection in Nigeria and suggest the presence of a rural HIV epidemic. The identification of HIV-1 group O in Kano shows that this virus strain is geographically widespread in Nigeria.

PIP: To obtain current data on HIV infection in Nigeria by population group, a seroanalysis of 2300 samples from 5 states (Lagos, Cross River, Borno, Kano, and Jugawa) was conducted during March-May 1996. The sample included commercial sex workers, pregnant women, tuberculosis patients, blood donors, patients with sexually transmitted diseases (STDs), patients with skin diseases, male clients of commercial sex workers, outpatients suspected to have AIDS, truck drivers, and community residents. Overall HIV prevalence was 40.7%. With the exception of pregnant women (1.7%), HIV prevalence was high in all subgroups: 60.6% in commercial sex workers, 21.2% in STD patients, 16.2% in tuberculosis patients, and 16.0% in rural areas of Kano state. The majority of HIV-positive women were 21-30 years of age, while HIV-infected men were primarily over 40 years of age. Compared with data from national seroprevalence studies conducted during 1991-92 and 1993-94, this study confirms a substantial recent increase in HIV infection in Nigeria. Of the 330 antibody-positive specimens, HIV-1 was the predominant infection in 315; there were 3 cases of HIV-2 and 12 cases involving dual HIV-1/2 infection. Only 1 serum sample was positive for HIV-1 group O antibodies. The high HIV prevalence detected among commercial sex workers indicates the potential for rapid diffusion of HIV to the general population.