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Background Human papillomavirus (HPV) is strongly associated with ano-genital and cervical cancer. Persistence of oncogenic HPV genotypes is required for development and progression of HPV-associated malignancies. Although, >70% of women clear incident HPV infections, data on natural history and HPV immunology among men is limited. Methods To evaluate cell-mediated immune response against natural HPV infection among men, we assessed cytokine (IFN-γ, TNF-α, IL-2, IL-4, IL-6, IL-10 and IL-13) responses in peripheral-blood-mononuclear cells (PBMCs) collected from 135 men enrolled in a prospective HPV cohort study. PBMCs were stimulated by HPV L1 gene viral-like-particles (VLP) and cytokine responses measured using a multiplex Luminex assay. Results Of 135 men included in this analysis, 41 men had persistent HPV infection, 44 men cleared HPV infection and 50 were HPV uninfected. Their mean (SD) ages were 28.9 (6.79), 27.6 (6.49) and 26.4 (4.81) years respectively. Immune response was induced in 22% (95% CI: 12.8–35.2) of HPV uninfected men, 64% (95% CI: 48.9–76.2) of men with HPV clearance and 51% (95% CI: 36.5–65.8) of men with HPV persistence. Men with HPV clearance and HPV persistence were significantly (p Conclusion In this study, Th1 cell-mediated cytokine immune response was associated with HPV clearance in men. Disclosure No significant relationships.

Human papillomavirus (HPV) is associated with ano-genital and cervical cancer. Persistence of oncogenic HPV genotypes is a requirement for development and progression of malignancies. Although,70% of women clear incident HPV infections, data on natural history and HPV immunology among men is limited. To evaluate cell-mediated immune responses to natural HPV infections among men, we assessed cytokine responses on PBMCs collected from men with persistent or cleared HPV. Men with HPV clearance and those with HPV persistence had increased odds (6-times and 3-times respectively) of mounting cytokine responses compared to HPV uninfected men. Th1 cytokines IFN-γ (5.1-fold) and IL-2 (4.2-fold) were significantly (p 0.0001) upregulated among men with HPV clearance compared to HPV uninfected men. Among men with HPV clearance compared to those with persistent HPV infection, only IFN-γ (2.4-fold) and IL-2 (3.0-fold) were significantly (p 0.0001) upregulated. Th1 cell-mediated cytokine response was associated with natural HPV clearance in men.

Background: Herpes simplex virus Type 2 (HSV-2) has been associated with HIV infection. More recently, HSV-2 incidence has been linked to HIV acquisition. A few studies have suggested that the fishing communities have a high HSV-2 prevalence but there is limited knowledge on HSV-2 incidence and associated risk factors among fishermen. Methods: Three hundred fishermen were consented, and evaluated for baseline HSV-2 serology status and again after 12 months among those negative at baseline. Sexual behavior and socio-demographic data were collected at enrolment and exit visits using a structured questionnaire. Baseline HIV serology and Human papillomavirus (HPV) DNA genotyping were also performed. Multivariate logistic regression was used to determine independent factors associated with HSV-2 acquisition. Results: Baseline HSV-2 prevalence was 56.3% (95% CI: 50.7 - 62.0). Factors associated with HSV-2 prevalence were, older age (aOR = 1.96; 95% CI: 1.16 - 2.85), history of STI (aOR 2.12; 95% CI: 1.19 - 3.91), infection with HIV (aOR 2.22; 95% CI: 1.17 - 4.22), ever married (aOR = 3.80; 95% CI: 1.42 - 11.90), most recent sexual act with sex worker/casual partner (OR= 3.56; 95% CI: 1.49 - 8.62) and inconsistent condom use with new sexual partner (aOR = 6.34; 95% CI: 2.24 - 13.04). The HSV-2 incidence was 23.6 (95% CI = 15.4 - 31.8)/100 pyr. Infection with persistent high-risk (HR) HPV (aIRR = 3.35; 95% CI: 1.21 - 11.37), multiple (≥2) partners in 12 months prior to study participation (aIRR = 4.77; 95% CI: 1.12 - 11.38), inconsistent condom use with new partner (aIRR =2.53; 95% CI: 1.12 - 7.38) and most recent sexual act with sex worker/casual partner (OR = 3.03; 95% CI: 1.17 - 8.58) were independent risk factors for HSV-2 acquisition. Conclusion: The incidence of HSV-2 is very high among fishermen. It is associated with persistent HR HPV infection and high-risk sexual behavior. Intervention strategies targeting these men with high risk sexual behavior are urgently needed to stop new HSV-2 acquisition and subsequently prevent HIV infection.

Background: Herpes simplex virus type-2 (HSV-2) and human papillomavirus (HPV) are common sexually transmitted infections (STIs) among fishing communities and are associated with high HIV prevalence in this underserved population. However, there is limited knowledge on HIV incidence among fishermen. This study aimed at determining prevalence, incidence and risk factors associated with HIV infection among fishermen in Kisumu Kenya. Methods: Three hundred fishermen were evaluated for baseline HIV, HSV-2, HPV infection and a structured questionnaire administered. HIV incidence was assessed after 12 months among those initially HIV negative. HIV incidence rate in person-years and prevalence were estimated. Multivariate logistic regression was used to determine factors independently associated with HIV acquisition. Results: HIV prevalence was 23.3% (95% CI: 18.5 - 28.1). Risk factors for baseline HIV prevalence were older age (aOR = 2.13; 95% CI: 1.25 - 5.07), history of STI (aOR 4.21; 95% CI: 2.07 - 9.34), baseline HPV infection (aOR 2.13; 95% CI: 1.05 - 4.77), number of lifetime sexual partners (>5) aOR = 5.76 (95% CI: 1.41 - 13.57) and transactional sex (aOR = 10.98; 95% CI: 1.86 - 19.34). Condom uses with new sexual partner (aOR 0.21, 95% CI: 0.08 - 0.55) and during most recent sexual act (aOR 0.09, 95% CI: 0.03 - 0.61), were negatively associated with HIV prevalence. HIV incidence was 4.2 (95% CI = 1.3 - 7.1) per 100 person-years with being single (aIRR = 8.32; 95% CI: 1.27 - 54.67) as an independent risk factor. Condom use with new sexual partner (aIRR = 0.11; 95% CI: 0.01 - 0.89) and recent sex with wife/regular girlfriend (compared to sex worker/casual partner; aIRR = 0.03; 95% CI: 0.01 - 0.35) were associated with reduced risk of HIV acquisition. Conclusion: Inconsistent condom use and transactional/casual sexual partnerships were the main high-risk sexual behaviors in addition to marital status explaining the high HIV acquisition rate among fishermen. Intensified safer sex promotion is urgently needed in this subpopulation to avert new HIV infections.

The genetic subtypes of HIV-1 circulating in northern Kenya have not been characterized. Here we report the partial sequencing and analysis of samples collected in the years 2003 and 2004 from 72 HIV-1-positive patients in northern Kenya, which borders Ethiopia, Somalia, and Sudan. From the analysis of partial env sequences, it was determined that 50% were subtype A, 39% subtype C, and 11% subtype D. This shows that in the northern border region of Kenya subtypes A and C are the dominant HIV-1 subtypes in circulation. Ethiopia is dominated mainly by HIV-1 subtype C, which incidentally is the dominant subtype in the town of Moyale, which borders Ethiopia. These results show that cross-border movements play an important role in the circulation of subtypes in Northern Kenya.

Large forensic mtDNA databases which adhere to strict guidelines for generation and maintenance, are not available for many populations outside of the United States and western Europe. We have established a high quality mtDNA control region sequence database for urban Nairobi as both a reference database for forensic investigations, and as a tool to examine the genetic variation of Kenyan sequences in the context of known African variation. The Nairobi sequences exhibited high variation and a low random match probability, indicating utility for forensic testing. Haplogroup identification and frequencies were compared with those reported from other published studies on African, or African-origin populations from Mozambique, Sierra Leone, and the United States, and suggest significant differences in the mtDNA compositions of the various populations. The quality of the sequence data in our study was investigated and supported using phylogenetic measures. Our data demonstrate the diversity and distinctiveness of African populations, and underline the importance of establishing additional forensic mtDNA databases of indigenous African populations.

To determine the feasibility of using short-course zidovudine (ZDV) to prevent mother-to-child transmission of human immunodeficiency virus (HIV) in a breastfeeding population in a rural area in Kenya, pregnant mothers attending clinics in seven health centers in western Kenya between 1996 and 1998 were requested to volunteer for participation in this study. The HIV-infected mothers were given a daily dose of 400 mg of ZDV starting at 36 weeks of gestation and another 300 mg every three hours intrapartum. After delivery, mothers and their children were followed-up and clinically monitored every 3-4 months for two years, and child and mother mortality rates were analyzed. Of the 825 mothers who consented, 216 (26.2%) were infected with HIV. Of those infected, 51 (23.6%) took the full prescribed dose, 69 (31.9%) took only the prenatal dose, and the remaining 96 (44.4%) did not take any dose. Failure to take ZDV was attributed mainly to delivery occurring earlier than expected, while non-compliance to the intrapartum dose was due to mothers giving birth at home and fear of traditional birth attendants. By the end of the second year, 75 HIV-exposed children (34.7%) and 33 HIV-infected mothers (15.3%) had died. The HIV-free survival of children at 24 months was significantly associated with mother survival (P < 0.001) and prenatal ZDV compliance (P < 0.003). Our findings suggest that implementation of programs for prevention of mother-to-child transmission of HIV in rural areas of Africa need to consider the various socioeconomic and cultural barriers that may prevent successful uptake of antiretroviral prophylaxes. Similarly, the rapid disease progression in mothers may eliminate the increase in child survival due to ZDV prophylaxis.

Hepatitis C virus is a great public-health concern worldwide. Phylogenetic analysis of the HCV genome has identified six different genotypes that have generally been divided into several subtypes. There is very little information on HCV seroprevalence and genotypes in Kenya. To determine the genotypes of HCV circulating in Kenya, blood donor samples were serologically tested and confirmed by polymerase chain reaction (PCR). Positive samples were cloned and sequenced, and phylogenetic analysis conducted to determine the HCV genotypes. One hundred Murex-seropositive samples were re-tested using a passive hemagglutination test, and 16 of these were identified as seropositive. Further testing of all of the samples by PCR identified only 10 of the 16 samples as positive. Thus, only 10 % (10/100) of the samples were viremic. Six were from females (60 %), and four were from males (40 %). The mean age of the positive donors was considerably low, at 25 +/- 9 years. Genotypic testing indicated the presence of genotype 1a (10 %) and genotype 2b (90 %). This study reports on HCV genotypes in a blood donor population in Kenya where little had been done to provide information on HCV genotypes.

DNA fragmentation and nuclear condensation are key features in the regulated cell death of higher animal cells. Nuclear death also occurs as part of a developmentally programmed process during the sexual life cycle of the unicellular organismTetrahymena.We examined the regulation of nuclear death and the relationship between DNA fragmentation and chromatin condensation in this model system. Nuclear death is accompanied by DNA digestion to low-molecular-weight oligonucleosomal-length fragments, in agree- ment with a previous study [17], indicating an endonuclease-like activity typical of apoptosis in higher organisms. Actinomycin D and cycloheximide block DNA digestion as well as nuclear condensation suggesting that nuclear death is under genetic regulation. DNA digestion is completely blocked by aurin, a general nuclease inhibitor. In addition, when DNA fragmentation is blocked, nuclear condensation also fails to occur. Moreover, a kinetic analysis of DNA breakdown, using agarose gels, shows that some DNA digestion occurs before nuclear condensation has taken place. Thus the initiation of DNA digestion may provide conditions necessary for nuclear condensation. Temporary inhibition of nuclear death aborts the death program since after removal of inhibitors cells revert to a vegetative pathway without having eliminated the old or developed the new macronucleus. Zn2+and EGTA, both of which inhibit apoptosis in some cell types, fail to prevent nuclear condensation or DNA digestion inTetrahymena,suggesting a requirement here for an endonuclease which is Ca2+-independent and Zn2+-insensitive. With the TUNEL assay, DNA breakdown is detected exclusively in the condensed macronucleus (and occasional micronuclei identified as degenerating haploid products of meiosis), but not in precondensed macronuclei. These studies show that apoptotic-like DNA fragmentation occurs after condensation of the degenerating macronucleus. However, early DNA digestion may be critical for nuclear condensation and subsequent degeneration.

Background Design of effective vaccines against the human immunodeficiency virus (HIV-1) continues to present formidable challenges. However, individuals who are exposed HIV-1 but do not get infected may reveal correlates of protection that may inform on effective vaccine design. A preliminary gene expression analysis of HIV resistant female sex workers (HIV-R) suggested a high expression CD26/DPPIV gene. Previous studies have indicated an anti-HIV effect of high CD26/DPPIV expressing cells in vitro. Similarly, high CD26/DPPIV protein levels in vivo have been shown to be a risk factor for type 2 diabetes. We carried out a study to confirm if the high CD26/DPPIV gene expression among the HIV-R were concordant with high blood protein levels and its correlation with clinical type 2 diabetes and other perturbations in the insulin signaling pathway. Results A quantitative CD26/DPPIV plasma analysis from 100 HIV-R, 100 HIV infected (HIV +) and 100 HIV negative controls (HIV Neg) showed a significantly elevated CD26/DPPIV concentration among the HIV-R group (mean 1315 ng/ml) than the HIV Neg (910 ng/ml) and HIV + (870 ng/ml, p < 0.001). Similarly a FACs analysis of cell associated DPPIV (CD26) revealed a higher CD26/DPPIV expression on CD4+ T-cells derived from HIV-R than from the HIV+ (90.30% vs 80.90 p = 0.002) and HIV Neg controls (90.30% vs 82.30 p < 0.001) respectively. A further comparison of the mean fluorescent intensity (MFI) of CD26/DPPIV expression showed a higher DPP4 MFI on HIV-R CD4+ T cells (median 118 vs 91 for HIV-Neg, p = 0.0003). An evaluation for hyperglycemia, did not confirm Type 2 diabetes but an impaired fasting glucose condition (5.775 mmol/L). A follow-up quantitative PCR analysis of the insulin signaling pathway genes showed a down expression of NFκB, a central mediator of the immune response and activator of HIV-1 transcription. Conclusion HIV resistant sex workers have a high expression of CD26/DPPIV in tandem with lowered immune activation markers. This may suggest a novel role for CD26/DPPIV in protection against HIV infection in vivo.

Background The HIV/AIDS epidemic in Kenya is a major public-health problem. Estimating the prevalence of HIV in pregnant women provides essential information for an effective implementation of HIV/AIDS control measures and monitoring of HIV spread within a country. The objective of this study was to determine the prevalence of HIV infection, risk factors for HIV/AIDS and immunologic (lymphocyte profile) characteristics among pregnant women attending antenatal clinics in three district hospitals in North-Rift, Kenya. Methods Blood samples were collected from pregnant women attending antenatal clinics in three district hospitals (Kitale, Kapsabet and Nandi Hills) after informed consent and pre-test counseling. The samples were tested for HIV antibodies as per the guidelines laid down by Ministry of Health, Kenya. A structured pretested questionnaire was used to obtain demographic data. Lymphocyte subset counts were quantified by standard flow cytometry. Results Of the 4638 pregnant women tested, 309 (6.7%) were HIV seropositive. The majority (85.1%) of the antenatal attendees did not know their HIV status prior to visiting the clinic for antenatal care. The highest proportion of HIV infected women was in the age group 21–25 years (35.5%). The 31–35 age group had the highest (8.5%) HIV prevalence, while women aged more than 35 years had the lowest (2.5%). Women in a polygamous relationship were significantly more likely to be HIV infected as compared to those in a monogamous relationship (p = 0.000). The highest HIV prevalence (6.3%) was recorded among antenatal attendees who had attended secondary schools followed by those with primary and tertiary level of education (6% and 5% respectively). However, there was no significant relationship between HIV seropositivity and the level of education (p = 0.653 and p = 0.469 for secondary and tertiary respectively). The mean CD4 count was 466 cells/mm3 (9–2000 cells/mm3). Those that had less than 200 cells/mm3 accounted for 14% and only nine were on antiretroviral therapy. Conclusion Seroprevalence of HIV was found to be consistent with the reports from the national HIV sentinel surveys. Enumeration of T-lymphocyte (CD4/8) should be carried out routinely in the antenatal clinics for proper timing of initiation of antiretroviral therapy among HIV infected pregnant women.

Eight genotypes of hepatitis B virus (A-H) and subgenotypes have been recognized worldwide. However, there is limited information on prevalent genotypes in many countries in Africa. This study was undertaken to determine the hepatitis B virus (HBV) genotypes in Kenya. Seropositive HBV blood samples from a blood donor setting were used in the study. HBV genotypes were determined in 52 nucleic acid-positive samples using specific primer in a nested PCR and sequencing employed in the HBV genotyping. This study shows presence of HBV variants with genotypes A (88%), E (8%) and D (4%). In conclusion, we found that HBV genotype A is the most predominant genotype in Kenya with both subgenotype A1 and A2 present. Genotype D and E are also present in our population. This demonstrates that there could be a high genetic diversity of HBV in Kenya.

Objective: To determine the pattern of opportunistic infections such as TB and Candida species in HIV infected patients in Northern Kenya. Design: Cross-sectional study. Setting: Five health facilities in Moyale (n=224) Mandera (n=121) and Turkana Kakuma; (n=83) Lopiding; (n=94) districts during different periods in 2003. Subjects: Five hundred and fifty two patients. Results: In total 94 (18%) patients were found to be HIV positive (Moyale=42 Mandera=l3 Turkana; Kakuma=8 Lopiding=31). Only 65 of 94 HIV positive patients provided saliva samples. Of these 11 (17%) were TB smear positive and 19 (29.2%) were colonized by oral Candida species. The Candida isolates were as follows; Co-infection of Candida species and TB (n=4) C. albicans only (n=12) C. tropicalis only (n=1) C. albicans and C. glabarata (n=1) and C. albicans C. glabarata and C. tropicalis. co-infection (n=1). Conclusion: The findings provide an important insight into the differences in mucosal susceptibility to bacteria (TB) infection and fungal (Candida species) colonization during HIV immunosuppression based on collected blood sputum and saliva specimens. Further studies are needed to elucidate the comparative transmission dynamics and pathogenetic mechanisms of these opportunistic infections in different regions of Kenya. Such studies would improve the efficiency of directly observed of directly observed preventive therapy programme (DOPT-P) whose implementation involves screening by tuberculin skin testing. (authors)

Background: Screening of blood and blood products for human immunodeficiency virus (HIV) is routinely performed using the enzyme-linked immunosorbent assay (ELISA), and the results confirmed by Western blot (WB). However, western blot is expensive and mostly performed in developed countries. A technique more superior or comparable to WB and adaptable to developing countries must be sought. In an effort to identify such a technique, this study determined the efficiency of indirect immunofluorescence assay (IFA) to detect antibodies to HIV-1. Objective: To determine the accuracy and sensitivity of an in-house immunofluorescence assay (IFA) to detect antibodies to HIV-1 in plasma. Design: A comparative study to evaluate the performance of indirect immunofluorescence assay (IFA) and western blot (WB) techniques in the detection of antibodies to HIV-1. Setting: Kenya Medical Research Institute, Centre for Virus Research. The study was conducted between June and December 2001. Methods: The evaluation of IFA as a technique for detecting antibodies to HIV-1 utilized a total of 400 samples. For these samples, IFA was compared with ELISA and particle agglutination (PA) (manuscript under preparation). Of the 400 samples, there were discrepant results in the three assays in only 36 samples. IFA was compared with Western blot (WB) to confirm the true HIV-1 serostatus in these 36 plasma specimens. The IFA technique used acetone-fixed HIV-1 infected MOLT-4 cells in one spot on a Teflon coated slide and uninfected MOLT-4 cells alone in a second spot to asses non-specific fluorescence. Western blot was performed according to the instructions of the manufacturer. Results: The sensitivity and specificity of IFA based on 36 plasma specimens tested was 71.4% and 100% respectively. All samples that were HIV seronegative by WB were also HIV seronegative by IFA. However, two (5.6%) samples were HIV seronegative by IFA but seropositive by WB. Conclusion: The data obtained show that IFA can be used as a primary confirmatory test in Kenya. East African Medical Journal Vol. 81 No. 5 May 2004: 222-225

To determine the feasibility of using short-course zidovudine (ZDV) to prevent mother-to-child transmission of human immunodeficiency virus (HIV) in a breastfeeding population in a rural area in Kenya, pregnant mothers attending clinics in seven health centers in western Kenya between 1996 and 1998 were requested to volunteer for participation in this study. The HIV-infected mothers were given a daily dose of 400 mg of ZDV starting at 36 weeks of gestation and another 300 mg every three hours intrapartum. After delivery, mothers and their children were followed-up and clinically monitored every 3-4 months for two years, and child and mother mortality rates were analyzed. Of the 825 mothers who consented, 216 (26.2%) were infected with HIV. Of those infected, 51 (23.6%) took the full prescribed dose, 69 (31.9%) took only the prenatal dose, and the remaining 96 (44.4%) did not take any dose. Failure to take ZDV was attributed mainly to delivery occurring earlier than expected, while non-compliance to the intrapartum dose was due to mothers giving birth at home and fear of traditional birth attendants. By the end of the second year, 75 HIV-exposed children (34.7%) and 33 HIV-infected mothers (15.3%) had died. The HIV-free survival of children at 24 months was significantly associated with mother survival (P0.001) and prenatal ZDV compliance (P0.003). Our findings suggest that implementation of programs for prevention of mother-to-child transmission of HIV in rural areas of Africa need to consider the various socioeconomic and cultural barriers that may prevent successful uptake of antiretroviral prophylaxes. Similarly, the rapid disease progression in mothers may eliminate the increase in child survival due to ZDV prophylaxis.

Objective: To investigate the effects of short-course nucleoside reverse transcriptase inhibitor (Zidovudine, ZDW/AZT) on maternal immune responses and risk of infant infection with HIV-1 among rural-based mothers in western Kenya. Design: A prospective cohort study involving HIV-1 seropositive pregnant mothers and their infants. Subjects: One hundred and seven HIV-1 seropositive asymptomatic pregnant women and their infants. Methods: After informed consent, the women were enrolled at gestation age between 16-24 weeks. For cultural and economic reasons, all mothers were allowed to breast feed their infants. Short-course antepartum regime of AZT was administered to all mothers starting at 36 weeks gestation until start of labour. Maternal absolute CD4+ T cell subset assays were performed before 3rd trimester (about 36 weeks gestation) and after a 4-week therapy of AZT (at least one month post-nuptially). Infant HIV- 1 status was determined by HIV-1 DNA polymerase chain reaction (PCR) on samples sequentially taken at 1, 2, 3, 4, 6 and 9 months and confirmed by serology at 18 months of age. Interventions: Antepartum short-course orally administered AZT: 300mg twice-daily starting at 36 weeks gestation until start of labour, 300mg at labour onset and 300mg every three hours during labour until delivery. Main Outcome Measures: Maternal CD4+ T cell counts before and after AZT treatment. Determination of infant HIV-1 infection status. Results: Among 107 women sampled, only 59 received full dose of AZT and thus qualified for present analysis. Of these, 12 infected their children with HIV, while 47 did not. Comparison of CD4+ T cells before and after AZT treatment scored a significant rise in all mothers (P = 0.01). This increase in CD4+ T cells was not significant among mothers who infected their infants with HIV-1 (P = 0.474). However, a significant rise in CD4+ T cells following AZT therapy was observed only in mothers who did not transmit HIV-1 to their infants (P=0.014). Conclusion: These data suggest that a rise in the CD4+ T cell counts following short AZT regimen, now widely in use in resource-weak countries, may be evidence of the active suppression of the replication of HIV. However, further studies to examine the multi-factorial effect of CD4+ lymphocytes and pregnancy on MTCT of HIV need to be carried out to help fully explain the effect of AZT on immune response and whether the CD4+T cell count can be used as a true test of immunological normalisation during antiretroviral therapy.

Most protozoan parasites, such as Leishmania, Plasmodium, Toxoplasma and Trypanosoma, rely on a salvage pathway for their supply of purine ribonucleotides (Wang, 1984). Inhibition of this pathway therefore presents an interesting approach in the fight against microbial infections. To explore the feasibility of this approach we have attempted to identify inhibitors of the essential purine salvage enzyme hypoxanthine-guanine-xanthine phosphoribosyl transferase (HGXPRTase) of the protozoan parasite Tritrichomonas foetus. This sexually transmitted parasite causes causes bovine trichomoniasis, which can lead to embryonic death and infertility in cows. T. foetus relies primarily on a single enzyme, HGXPRTase, to transfer ribose 5-phosphate from α-D-5-phosphoribosyl-1-pyrophosphate to the N9 nitrogen atom of hypoxanthine, guanine or xanthine (Wang et al., 1983). Selectivity with respect to the mammalian enzyme hypoxanthine-guanine-phosphoribosyl transferase (HGPRTase), that has 27% sequence identity with the parasite enzyme, is important to avoid serious side effects. Currently available inhibitors are purine analogues with affinities in the millimolar range (Jadhav et al., 1979). Here we report the use of the molecular docking program DOCK 3.5 (Kuntz et al., 1982; Meng et al., 1993) for the discovery of more potent, novel inhibitors of HGXPRTase that are selective with respect to the human enzyme (Somoza et al., 1998).

Acridine orange (AO) has been used as a vital fluorescent stain to identify apoptotic cells in Drosophila, but little is known about what structures are stained. We explored the specificity of AO staining while studying nuclear apoptosis in Tetrahymena. Using AO alone or together with the vital nuclear stain Hoechst 33342 (HO), we find that lysosomes are generally clustered around the degenerating nucleus and that such nuclei are stained an orange-red color, like lysosomes. Significantly, the combined dyes, more so than with AO alone, distinguish between apoptotic and normal (or necrotic) nuclei by a clear color difference. Moreover, these dyes differentially stain apoptotic and normal nuclei in avian chondrocytes. The differential staining results are nullified in fixed cells or in cytoskeletal preparations treated with RNAse. Similarly, lysosomotrophic agents eliminate the differential staining. Our results are consistent with acidification of the apoptotic nucleus, possibly by fusion with lysosomes. However, even under basic conditions, the macronucleus condenses and is eliminated, suggesting that, if the nucleus is becoming acidified, acidification by itself is not essential for nuclear elimination. The differential staining procedure may provide a useful method for specifically identifying apoptotic cells and separating them for further analysis. (J Histochem Cytochem 45:675–683, 1997)

Background Men with high-risk sexually behaviour are important drivers of HIV/STI infections in the general population. Prevention of HIV/STIs among such men could potentially reduce these infections especially among women - who bear the greatest HIV/STIs disease burden in sub Saharan Africa. We sought to understand immunovirology of HPV infections among fishermen. This evaluation highlights the rate of HIV infections in this population. Methods Three hundred fishermen were recruited and followed up every 3 months for 1 year. HIV, syphilis serology, CD4/CD8 and complete blood count were evaluated and a demographic questionnaire administered. Data was analysed by SPSS ver18. Results The 300 men recruited into this study had mean age of 28 years, 76% were married and 57% had only basic education. The mean for age of sexual debut and lifetime sexual partners was 15 years and 10 respectively. They had a modal sexual activity of 3 times/week and a mean of 3 rounds/sexual act. Sixty one (20%) had practised oral sex. Thirty six (12%) and 80 (27%) of men washed their genitals, before and after sex respectively. A significant number of men; 183 (61%) P Conclusion Fishermen in this context, comprise a young sexually high-risk, highly-migratory population with high HIV incidence and prevalence. Low condom use coupled with concurrent multiple sexual partnerships make them a potential key population who require targeted prevention strategies to reduce HIV/STI infections and transmission.

Objective :To understand the natural history of HIV-1 infection in children in terms of evolution of childhood clinical manifestations versus the immune status, we prospectively studied children with and without maternally transmitted HIV-1 infection born to mothers infected with HIV-1 for two years between March 1998 and March 2000. Design :A prospective cohort study. Setting :An institutional children's home. Subjects :Fifty nine children (26 males and 33 females) with and without maternally transmitted HIV-1 infection born to mothers infected with HIV-1 and adopted in institutional children home. Methods :HIV-1 status of children under nine months was confirmed by polymerase chain reaction (PCR). ELISA for HIV-1 antibody in serum/plasma was used to confirm HIV-infection status for children aged £18 months. Children were visited every three months between March and June 2000. At every visit blood was collected for total white cell count, haemoglobin and CD4+ and CD8+ T cell counts. The institutional doctor routinely examined children and treated all ailments. Clinical data were recorded. Measures : HIV-DNA, anti-HIV antibodies, total white blood count, total T cell counts, CD4 and CD8 T cell subset counts, frequency of childhood manifestations of infection. Results :The children were aged between 4.5 and 13 years. The baseline haematological and immunological profiles (mean, mode) were: HIV-1 sero-converters (WBC 7151,7150; HB 11.6, 12.0; CD4+ 686, 795; CD8+ 2168, 1507) and HIV-1 de-seroconverters (mean, mode) were: (WBC 8386, 7150; HB 11.7, 12.8; CD4+ 735, 795; CD8+ 2168, 1507). The commonest causes of illnesses among the HIV-1 children were URTI (85.3%), TB(56.1%), pneumonia (56.2%), tonsillitis (34.1%), parotiditis (28%) and acute otitis media (25%). The distribution of clinical manifestations was similar between the two categories of children, except URTI, whose prevalence was significantly increased among HIV-1 infected children (p-value=0.006). Among the HIV-1 infected children, only TB, parotiditis, and acute otitis media (AOM) were significantly associated with decreased CD4+ T cell count (p Conclusions : HIV infection in children predisposes them to common childhood infections that can be used as markers of immune decline. TB, AOM, URTI may be early indicators of suspicion that would enable selective screening for HIV infection in children. (East African Medical Journal: 2003 80(2): 95-100)

Background: Men with high-risk sexual behavior are important drivers of HIV/STIs in the general population. Prevention of HIV/STIs among suchmen could potentially reduce these infections among women who bear the greatest HIV/STIs disease burden. HSV-2 infection has been shown to be strongly associatedwith HIV infections. We sought to estimate the incidence of HSV-2 infection among fishermen. MethodsM 183 (61%) P