Occurrence of oral lesions in relation to clinical and immunological status among HIV-infected adult Tanzanians

OBJECTIVE: To determine the association, if any, between the presence of oral lesions and clinical and immunological status of untreated HIV-infected adults in Tanzania. DESIGN: A cross-sectional study. SETTING: AIDS Clinical Trial Clinic (ATCC) at Muhimbili Medical Centre in Dar-es-Salaam, Tanzania. SUBJECTS: 192 HIV-infected individuals not receiving treatment; 156 individuals confirmed to be HIV-seronegative acted as a control group. METHODS: Examination of oral structures, determination of HIV serostatus, clinical status, and peripheral CD4+ T cell and total lymphocyte counts. MAIN OUTCOME MEASURE: Presence of oral lesions. RESULTS: Intra-oral lesions were seen among 7.7% of the HIV-seronegative, 10.4% of the HIV-seropositive and 36.8% of the AIDS groups, respectively. Enlarged parotid glands were seen in 20% of the AIDS patients, 11.9% of the HIV-seropositives, and 5.1% of the HIV seronegatives. Enlargement of submandibular salivary glands was seen in 29.6% of the AIDS patients, 31.3% of the HIV-seropositives compared with 14.7% among the HIV-seronegatives. Multiple regression analysis was used to calculate adjusted odds ratio (OR) for presence of oral lesions. OR for an intra-oral lesion was 1.6 (95% CI = 0.5; 5.0) among the HIV-seropositives and 8.2 (95% CI = 3.5; 19.7) among the AIDS patients using the HIV-seronegatives as reference. OR for an intra-oral lesion was 0.9 (95% CI = 0.3; 2.9) in HIV-infected patients with peripheral CD4+ T cell count of between 200-500 cells mm-3 and 2.7 (95% CI = 0.9; 7.7) in patients with less than 200 cells mm-3. OR for an intra-oral lesion was 0.4 (95% CI = 0.2; 0.9) for patients with peripheral total lymphocyte counts of between 1000-2000 cells mm-3 and 0.9 (95 CI = 0.4; 2.0) for patients with less than 1000 cells mm-3. CONCLUSION: The association of oral lesions with the clinical stage of HIV infection and to a lesser extent peripheral CD4+ T cell count does suggest that these lesions could be used as additional markers of immunosuppression and AIDS.     

Antimicrobial activity of tanzanian chewing sticks against oral pathogenic microbes

Methanol extracts from the bark and wood of ten plants used as chewing sticks in Morogoro region, in Tanzania, were tested for their ability to inhibit the growth of cariogenic bacteria, Streptococcus mutans , Actinomyces viscosus and a yeast Candida albicans . Screening for antimicrobial activity was done by the agar-hole diffusion method, and minimum inhibitory concentrations (MICs) were determined by the agar dilution method. Extracts from seven out of the ten plants showed varying degrees of growth inhibitory effect on the microorganisms, with Acacia senegal var. senegal stem bark being the most active, followed by the stem bark of Eriosema psoraleoides . Their MICs ranged from 0.63 mg/ml to 5 mg/ml. Three plants Ocimum suave , Opilia celtidifolia and Xerophyta suaveolens did not exhibit any antimicrobial effect. Actinomyces viscosus was relatively more sensitive to the extracts than S. mutans and C. albicans . This study has also demonstrated that most bark extracts possessed antimicrobial activity, while many wood extracts were inactive. It is, therefore, advisable to use, for toothbrushing, unpeeled, rather than peeled chewing sticks, in order to exploit fully their antimicrobial effect. However, additional studies are needed to determine their antiplaque, anticaries and antimycotic effects.     

Activation of estrogen receptor alpha and ERbeta by 4-methylbenzylidene-camphor in human and rat cells: comparison with phyto- and xenoestrogens

4-Methylbenzylidene-camphor (4-MBC) is an organic sunscreen that protects against UV radiation and may therefore help in the prevention of skin cancer. Recent results on the estrogenicity of 4-MBC have raised concerns about a potential of 4-MBC to act as an endocrine disruptor. Here, we investigated the direct interaction of 4-MBC with estrogen receptor (ER) alpha and ERbeta in a series of studies including receptor binding, ER transactivation and functional tests in human and rat cells. 4-MBC induced alkaline phosphatase activity, a surrogate marker for estrogenic activity, in human endometrial Ishikawa cells. Interestingly, 4-MBC induced weakly ERalpha and with a higher potency ERbeta mediated transactivation in Ishikawa cells at doses more than 1 microM, but showed no distinct binding affinity to ERalpha or ERbeta. In addition, 4-MBC was an effective antagonist for ERalpha and ERbeta. In an attempt to put 4-MBC's estrogenic activity into perspective we compared binding affinity and potency to activate ER with phyto- and xenoestrogens. 4-MBC showed lower estrogenic potency than genistein, coumestrol, resveratrol, bisphenol A and also camphor. Analysis of a potential metabolic activation of 4-MBC that could account for 4-MBC's more distinct estrogenic effects observed in vivo revealed that no estrogenic metabolites of 4-MBC are formed in primary rat or human hepatocytes. In conclusion, we were able to show that 4-MBC is able to induce ERalpha and ERbeta activity. However, for a hazard assessment of 4-MBC's estrogenic effects, the very high doses of 4-MBC required to elicit the reported effects, its anti-estrogenic properties as well as its low estrogenic potency compared to phytoestrogens and camphor has to be taken into account.     

Virological efficacy and emergence of drug resistance in adults on antiretroviral treatment in rural Tanzania

Background  

Virological response to antiretroviral treatment (ART) in rural Africa is poorly described. We examined virological efficacy and emergence of drug resistance in adults receiving first-line ART for up to 4 years in rural Tanzania.     

Lymphocyte proliferation to mycobacterial antigens is detectable across a spectrum of HIV-associated tuberculosis

Background  

Identifying novel TB diagnostics is a major public health priority. We explored the diagnostic characteristics of antimycobacterial lymphocyte proliferation assays (LPA) in HIV-infected subjects with latent or active TB.     

Anticandidiasis agents from a Tanzanian plant, Combretum zeyheri

Combretum zeyheri Sond (Combretaceae) has been reported to exhibit anticandida activity against Candida kruzei, C. albicans, and C. parapsilosis; however, the active constituents have not been isolated so far. A bioactivity-guided fractionation of MeOH extract of C. zeyheri resulted in the isolation of triterpenoids, ursolic acid (1.1), oleanolic acid (1.2), maslinic acid (2.1), 2α,3β-dihydroxyurs-12-en-28-oic acid (2.2), 6β-hydroxymaslinic acid (3), and terminolic acid (4). These compounds were characterized on the basis of their 1D, 2D NMR, ESI-MS and FT-IR spectroscopic data. All the isolated compounds, 1.2, 2.1, 2.2, 3, and 4 except ursolic acid (1.1) are being reported for the first time from C. zeyheri. Later, the isolated triterpenoids (1–4) were evaluated for their anticandida activity against the three strains of C. albicans and all compounds showed anticandida activity of which terminolic acid (4) was most active. Furthermore, structure–activity relationship of isolated triterpenoids (1–4) was studied, which showed that triterpenoids of oleanane and ursane having 2α,3β,23-trihydroxyl group are more active.