Spatial analysis of tuberculosis in Douala, Cameroon: clustering and links with socio-economic status.

SETTING: Douala, the economic capital of Cameroon, with a network of 20 diagnostic and treatment centres for tuberculosis (TB). OBJECTIVE: To describe the spatial distribution of smear-positive pulmonary tuberculosis (PTB) cases in Douala, Cameroon, and to evaluate links between PTB incidence and patients' socio-economic status (SES). DESIGN: Between May 2011 and April 2012, demographic clinical characteristics and global positioning system coordinates for the residence of each consenting PTB case were collected. Spatial scan statistic was used to identify spatial clusters of tuberculosis. SES data were collected by interview during home visits. PTB patients' SES data were compared with those available for the whole urban population from a recent demographic and health survey. The correlation between PTB incidence and the mean SES of the PTB patients was examined by health area (HA). RESULTS: In total, 2132 (84%) diagnosed PTB cases were identified and interviewed. Three statistically significant spatial clusters were identified. High PTB incidence was predominantly found in HAs characterised by low SES. CONCLUSION: There is evidence of clustering of PTB cases in Douala. Clusters are mainly found in neighbourhoods of low SES. Systematic use of cluster detection techniques for regular TB surveillance in Cameroon might aid in the effective deployment of National TB Programme resources.

Effects of alpinumisoflavone and abyssinone V-4'-methyl ether derived from Erythrina lysistemon (Fabaceae) on the genital tract of ovariectomized female Wistar rat.

Erythrina lysistemon is an African medicinal plant used as a palliative for problems in women. The crude extract of this plant was shown to exhibit estrogenic effects on the female rat reproductive tract and on cell cuture. Using classic chromatographic methods, two compounds have been isolated as major constituents of this extract: alpinumisoflavone (1) and abyssinone V-4'-methyl ether (2). To determine whether both compounds are actives principles accounting for E. lysistemon effects, we applied the classic 3-day uterotrophic assay. We also carried out a ligand binding assay to determine whether the observed effects are estrogen receptor (ER) mediated. This study showed that whereas compound 1 displayed a fourfold preference for ERα, compound 2 bound ERα and ERß with a same affinity. The in vivo study showed that compound 1 increased the uterine wet weight by 182.23% (p < 0.01) and 71.79% (p < 0.05) at doses of 0.1 and 1 mg/kg BW/day respectively. The uterine epithelium thickened dose-dependently. Vaginal epithelial height also increased by 369.97 and 226.76% respectively (p < 0.01). Compound 2 acted only on the vagina and increased vaginal epithelial height by 244.56% (p < 0.01) at 1 mg/kg BW/day. These results suggest that compounds 1 and 2 are endowed with estrogenic properties accounting, at least in part, for E. lysistemon effects.

A postmenopause-like model of ovariectomized Wistar rats to identify active principles of Erythrina lysistemon (Fabaceae).

To determine whether the two major compounds of Erythrina lysistemon are active principles accounting for Erythrina estrogenic effects, we used a postmenopause-like model of ovariectomized Wistar rats to evaluate their effects on some menopausal problems. Ovariectomized rats were orally treated either with compound 1 or compound 2 at 1 and 10 mg/kg BW for 28 days. Estradiol valerate served as the reference substance. As results, compounds 1 and 2 displayed estrogen-like effects on the uterus and the vagina, and reduced atherogenic risks by decreasing the two assessed atherogenic parameters, the total cholesterol/HDL-cholesterol ratio and the atherogenic index of plasma.

Triterpenoids from Drypetes chevalieri Beille (euphorbiaceae).

The CH2Cl2/CH3OH (1/1) extract of the dried stem of Drypetes chevalieri Beille afforded two new triterpenoïds named drypechevalin A (11-oxo-beta-amyrin-3beta-ylcaffeate) and drypechevalin B (3,7-dioxo-D:A-friedooleanan-24-al) along with five known compounds: lupeol, lupeone, erythrodiol, putranjivadione, friedelin. Their structures were established on the basis of spectroscopic analysis and chemical evidence.

Chalconoid and stilbenoid glycosides from Guibourtia tessmanii.

Phytochemical studies on the stem bark of Guibourtia tessmanii yielded a dihydrochalcone glucoside, 2',4-dihydroxy-4'-methoxy-6'-O-beta-glucopyranoside dihydrochalcone and a new stilbene glycoside, 3,5-dimethoxy-4'-O-(beta-rhamnopyranosyl-(1-->6)-beta- glucopyranoside) stilbene besides the known pterostilbene. Their structures were established on the basis of one and two dimensional NMR spectroscopic techniques, FABMS and chemical evidence.

Sesquiterpene lactone and friedelane derivative from drypetes molunduana.

A new sesquiterpene lactone, drypemolundein A and a new friedelane derivative, drypemolundein B, along with seven known compounds have been isolated from the whole stems of Drypetes molunduana Pax and Hoffm. Their structures were established on the basis of one- and two-dimensional NMR, homo- and hetero-nuclear spectroscopic evidence.

Erysenegalenseins H and I: Two New Isoflavones from Erythrina senegalensis1.

In addition to the known Compounds senegalensin, lupinifolin, erythrisenegalone, and auriculatin, two new isoflavones named erysenegalensein H and erysenegalensein I were isolated from the dichloromethane extract of the stem bark of ERYTHRINA SENEGALENSIS DC. On the basis of spectroscopic methods their structures were elucidated as 5,2',4'-trihydroxy-8-(gamma,gamma-dimethylallyl)-2''-hydroxyisopropyldihydrofurano[4'',5'':6,7]-isoflavone and 5,2',4'-trihydroxy-8-(gamma,gamma-dimethylallyl)-3''-hydroxy-2'',2''-dimethyldihydropyrano [5'',6'':6,7]-isoflavone, respectively.

A new prenylated isoflavone and long chain esters from two Erythrina species.

Two new compounds, a long chain ester 1 of p-coumaric acid and a prenylated isoflavone, senegalensin [5], 5,4'-dihydroxy-8-(gamma,gamma-dimethylallyl)-[5"-(hydroxyisopropyl ) (2",3":6.7)] isoflavone, in addition to a known long chain ester 2 of ferulic acid, have been isolated and characterized from the stem bark of the Cameroonian medicinal plant Erythrina senegalensis. Another known compound 3, a long chain ester of ferulic acid, was isolated from Erythrina excelsa. The structures of all the compounds were determined by spectroscopic techniques.