An improved PCR method for detection of HIV-1 proviral DNA of a wide range of subtypes and recombinant forms circulating globally

Proviral DNAs are being measured increasingly as a marker of the efficacy of highly active anti-retroviral therapy (HAART) and is accepted for the early diagnosis of perinatal HIV-1 infections. This requires a standardized test which enables the detection of a wide range of subtypes worldwide including O, N and circulating recombinant forms (CRFs). Based on a previous publication, a PCR - Test for HIV-1 provirus detection in peripheral blood mononuclear cells (PBMCs) was developed. Blood samples from 80 individuals infected with HIV-1 and 20 persons negative for HIV-1&2 from Africa and Germany were tested for the presence of HIV-1 provirus DNA. The primer system used enables the detection of proviral DNA despite the high concentrations of human DNA. The limit of detection was determined to be 5 copies per 10(5) cells. All 20 samples from persons negative for HIV were negative for HIV-1 proviral DNA while provirus DNA was amplified from 76 of the 80 (95%) samples from persons infected with HIV. The amplified products were detected by gel-electrophoresis, flow cytometry and real-time PCR. All three detection systems provided the same results.     

HIV sero-prevalence among children diagnosed with TB in Nigeria

A total of 76 children diagnosed with TB were screened for HIV. Eight (10.5%) were found to be HIV seropositive.     

Elective laparoscopic cholecystectomy in the presence of common bile duct stent

Background  

Endoscopic retrograde cholangiopancreatography (ERCP) is a common procedure done in patients with common bile duct (CBD) stones. Some clinicians insert a CBD stent at the time of ERCP. Such patients may then present for laparoscopic cholecystectomy (LC) with CBD stents in situ. The aim of this study was to examine the impact of the presence of a CBD stent on the outcome of elective LC.     

Probiotics, dendritic cells and bladder cancer

What's known on the subject? and What does the study add? The suppressor effect of probiotics on superficial bladder cancer is an observed phenomenon but the specific mechanism is poorly understood. The evidence strongly suggests natural killer (NK) cells are the anti‐tumour effector cells involved and NK cell activity correlates with the observed anti‐tumour effect in mice. It is also known that dendritic cells (DC) cells are responsible for the recruitment and mobilization of NK cells so therefore it may be inferred that DC cells are most likely to be the interphase point at which probiotics act. In support of this, purification of NK cells was associated with a decrease in NK cells activity. The current use of intravesical bacille Calmette‐Guérin in the management of superficial bladder cancer is based on the effect of a localised immune response. In the same way, understanding the mechanism of action of probiotics and the role of DC may potentially offer another avenue via which the immune system may be manipulated to resist bladder cancer. Probiotic foods have been available in the UK since 1996 with the arrival of the fermented milk drink (Yakult) from Japan. The presence of live bacterial ingredients (usually lactobacilli species) may confer health benefits when present in sufficient numbers. The role of probiotics in colo‐rectal cancer may be related in part to the suppression of harmful colonic bacteria but other immune mechanisms are involved. Anti‐cancer effects outside the colon were suggested by a Japanese report of altered rates of bladder tumour recurrence after ingestion of a particular probiotic. Dendritic cells play a central role to the general regulation of the immune response that may be modified by probiotics. The addition of probiotics to the diet may confer benefit by altering rates of bladder tumour recurrence and also alter the response to immune mechanisms involved with the application of intravesical treatments (bacille Calmette‐Guérin).     

Pregnancy outcome in the elderly primigravidae.

We assessed the effect of advancing maternal age ( 35 years) on the outcome of pregnancy in first births among 50 elderly primigravidae compared with a control group of 50 younger primigravidae (20-29 years) at the University College Hospital Ibadan from 1 January 1988 to 31 December 1992. Most of the elderly primigravidae were professionals and the majority of them (68%) had involuntary infertility. Frequent hospital admissions, preterm delivery, low birth weights and very high caesarean section rates were the major problems highlighted in the elderly primigravidae, while anaemia was more frequent in the younger primigravidae. Unnecessary caesarean sections on the excuse of 'precious' baby in the elderly primigravidae should be discouraged bearing in mind its medico-social implications. It is concluded that although the elderly primigravidae may have higher rates of complications of pregnancy, delivery and neonatal deaths their overall risk of referral to special care baby unit is not appreciably increased.     

Isolation and characterization of a new subtype A variant of human immunodeficiency virus type I from Nigeria

We have isolated a new variant of HIV‐1 from Nigeria, Africa. The virus was recovered from the peripheral blood mononuclear cells (PBMCs) of an apparently healthy 23‐year‐old male from Ibadan, Nigeria. The in vitro studies indicated that the virus was highly cytopathic and replicated well in normal PBMCs, established T‐cell lines and the monocytic cell line U937. The highest replicative titre of the virus was obtained in freshly isolated primary macrophage/monocyte cells which also showed the least cytopathology. Most other cultures showed single‐cell cytolysis and giant cells, and syncytia were not induced in the HTLV‐1 infected MT‐2 cells. Since no HIV strain has been isolated from Nigeria, we obtained cDNA clones containing the env gene, to further characterize the Nigerian virus. Based on the DNA sequence analysis of 14 clones containing the coding region for its gp 120 protein, the Nigerian HIV isolate has been classified as HIV‐1 subtype A. Only one subtype A virus from Rwanda has been characterized and this virus has not been shown to exhibit extreme cytopathicity in various cell types as was observed with the Nigerian strain. Further, the ability of this virus to grow well in lymphocytes, monocytes and macrophages and to exhibit cytopathicity without causing syncytia are uncommon properties distinguishing the Nigerian virus from other HIV‐1 strains. Since most macrophage‐tropic viruses have been associated with 'neurotropism', the isolation of an HIV‐1 strain from the blood of an individual with no known neurological disorder indicates that this rapidly replicating cytopathic virus, with a broad host range, may play an important role in the pathogenesis of HIV disease. This represents the first report of an HIV‐1 isolate from Nigeria.