Diagnostic value of Xpert MTB/RIF assay on pleural tissue obtained via closed pleural biopsy among persons with presumptive tuberculous pleuritis.

BACKGROUND: Tuberculous pleuritis (TBP) is a common extrapulmonary tuberculosis that contributes to the tuberculosis burden. Xpert MTB/RIF assay is a promising method for rapid diagnosis of TBP. The diagnostic value of Xpert MTB/RIF assay in pleural tissue obtained via closed pleural biopsy among sputum acid-fast bacilli (AFB) smear-negative persons is not well studied. OBJECTIVES: To evaluate the diagnostic value of Xpert MTB/RIF assay on diagnosis of TB in pleural tissue obtained via blind closed pleural biopsy. METHODS: Closed pleural biopsy using Cope needle was performed on adult patients who presented with lymphocyte predominant exudative pleural effusion. Xpert MTB/RIF assay was performed in parallel to pathology and mycobacterial culture of the pleural tissue specimen to determine its sensitivity and specificity. Final clinical diagnosis of TBP was determined by improvement in 2-months follow-up of anti-tuberculous treatment. RESULTS: A total of 33 patients were included in the study. The median (interquartile range (IQR)) age was 27 (25 - 42) years. The sensitivity and specificity of Xpert MTB/RIF assay was 30% and 100% compared with Mycobacterium tuberculosis culture as the gold standard, and 20% and 95.7% compared with histopathology as the gold standard. CONCLUSION: Xpert MTB/RIF assay in pleural tissue obtained by closed pleural biopsy did not increase diagnostic yield, but it shortens time for diagnosis compared with conventional methods.

Xpert MTB/RIF assay for the diagnosis of extrapulmonary tuberculosis: a diagnostic evaluation study.

OBJECTIVES: The diagnosis of extrapulmonary tuberculosis (EPTB) is often made on clinical suspicion alone, resulting in both under- and overdiagnosis and relatively poor outcomes. In this study, we evaluated the clinical utility of the Xpert MTB/RIF on routinely collected extrapulmonary specimens in Ethiopia. METHODS: This study was carried out at Jimma University Specialized Hospital, Southwest Ethiopia. Extrapulmonary specimens were collected from 572 patients clinically suspected of suffering from EPTB. All specimens were tested for TB by smear microscopy, culture, and Xpert MTB/RIF. The diagnostic accuracy of Xpert MTB/RIF was calculated and compared to a composite reference standard (CRS), comprising clinical and laboratory results. RESULTS: In total, 572 extrapulmonary specimens (279 lymph node, 159 pleural, 80 peritoneal, 45 cerebrospinal, and nine pericardial fluids) were tested. The pooled sensitivity and specificity of Xpert MTB/RIF were calculated to be 75% (95% CI 70-80) and 98% (95% CI 97-100) respectively when compared to the CRS. The highest sensitivity was documented for lymph node specimens (90%; 95% CI 86-94), moderate sensitivity for cerebrospinal fluid (53%; 95% CI 28-79), while the sensitivity was lowest for pleural (30%; 95% CI 17-44) and peritoneal (32%; 95% CI 12-51) fluids. Xpert MTB/RIF in addition detected rifampicin resistance in 13 patients, in perfect agreement with results from the line probe assay. CONCLUSIONS: Xpert MTB/RIF may be used as initial diagnostic tool for testing of lymph node specimens from patients suspected of having TB lymphadenitis. The added value of Xpert MTB/RIF to diagnose pleural or peritoneal TB is limited by its poor sensitivity.

Tagasaste (Chamaecytisus palmensis) leaf supplementation to enhance nutrient intake and production performance of sheep in the Ethiopian highlands.

The objective of this study was to determine the effect of supplementing increasing levels of dried tagasaste (Chamaecytisus palmensis) leaf on the nutrition and performance of sheep fed a basal diet of barley straw. The study had four treatments, which involved supplementation of dried tagasaste leaf at 100, 200, 300, and 400 g/day. Twenty-four yearling Menz sheep (weight 17 ± 0.83 kg) were assigned to one of the four treatments in a randomized complete block design. The experiment comprised a feeding trial lasting for 90 days, a digestibility trial, and carcass evaluation using all animals. Samples of the feed consumed, refused, and feces were analyzed for nutrients. Intake and digestibility of dry matter (DM) and nutrients increased linearly (P < 0.001) as tagasaste supplementation increased from 100 to 400 g/day. Similarly, average daily body weight gain increased linearly (P < 0.001) from 20 to 73 g/day, feed conversion efficiency from 0.04 to 0.10, and dressing percentage from 40 to 48%, as the supplementation increased from 100 to 400 g/day. Proportion of tagasaste leaf in the diet increased from 20 to 50%, while the ratio of neutral detergent fiber (NDF) to crude protein (CP) decreased from 7.9 to 5.3, as the level of supplementation increased. It was thus concluded that supplementation of dried tagasaste leaf up to 50% of the diet DM, resulting in a NDF:CP ratio of 5.3, produces no deleterious effects on the performance of sheep, and inclusion to this level can be applied for superior growth performance and carcass yield in sheep fed crop residue-based diets.

Preference of goats (Capra hircus L.) for tanniniferous browse species available in semi-arid areas in Ethiopia.

The objectives were to determine browse species preference of goats using dry matter intake (DMI) as a proxy, to compare preference when offered in combination with polyethylene glycol (PEG) and to establish relationships between browse species intake and chemical compositional data. Air-dried leaves of Acacia etbaica, Cadaba farinosa, Capparis tomentosa, Dichrostachys cinerea, Dodonaea angustifolia, Euclea racemosa, Maerua angolensis, Maytenus senegalensis, Rhus natalensis and Senna singueana were used. Two cafeteria trials, each lasting 10 days, were conducted using four local mature male goats of 2-2.5 years receiving a daily ration of grass hay (4% of body weight) and 200 g wheat bran. In trial 1, goats were offered 25 g of each browse species for a total of 30 min with intake, time spent on consumption and the number of visits to specific browse species recorded at 10-min intervals. In trial 2, the same procedure was followed except that 25 g of PEG 4000 was added to the daily wheat bran ration. Crude protein and neutral detergent fibre in browse species ranged from 69.0-245.5 to 159.8-560.6 g/kg dry matter (DM) respectively. Total phenols and total tannins contents ranged between 3.7-70.6 and 2.5-68.1 mg tannic acid equivalent/g DM, respectively, and condensed tannins 1.7-18.4 Abs550 nm /g DM. Preference indicators measured in the first 10 min of browse species intake differed significantly among browse species and with PEG (p < 0.0001). Principal components explained 69.9% of the total variation in browse species DMI. Despite the high tannin levels, D. cinerea, R. natalensis and A. etbaica were the most preferred species regardless of PEG presence. Tannin levels at the observed browse species DMI did not determine preference, instead, preference appeared to be based on hemicellulose. Determining browse species preference is essential to exploit them to improve nutrient utilization and control parasites in goats.

Isolation and characterisation of novel antioxidant constituents of Croton zambesicus leaf extract.

A 1,1-diphenyl-2-picrylhydrazyl (DPPH)-activity-directed fractionation was used to target antioxidant constituents of the ethyl acetate fraction obtained from a 20% aqueous methanol crude extract of Croton zambesicus leaf. Repeated column chromatography of the fraction on silica gel and Sephadex LH-20 led to the isolation of a new natural product, identified as quercetin-3-O-ß-6″(p-coumaroyl) glucopyranoside-3'-methyl ether, helichrysoside-3'-methyl ether (1), along with kaempferol-3-O-ß-6″(p-coumaroyl) glucopyranoside, tiliroside (2) and apigenin-6-C-glucoside, isovitexin (3) as the antioxidant constituents. The structures of the isolated compounds were elucidated using spectroscopic techniques, namely NMR (1D and 2D) and mass spectrometry. Compounds 1 and 2 are reported from this species for the first time. In the qualitative antioxidant assay, the three isolated compounds instantly bleached the DPPH (0.2% MeOH) purple colour indicating antioxidant activity. In the quantitative antioxidant assay, all the isolated compounds demonstrated weak antioxidant activity compared to quercetin and rutin used as positive control antioxidant agents. The compounds displayed little to no cytotoxicity against Vero cells in an in vitro assay. The presence of these antioxidant compounds in the leaf extract of C. zambesicus could provide a rationale for the ethnomedicinal use of the plant in the management of oxidative-stress-related diseases in folk medicine.

Evaluation of n-alkanes and their carbon isotope enrichments (δ(13)C) as diet composition markers.

Plant cuticular n-alkanes have been successfully used as markers to estimate diet composition and intake of grazing herbivores. However, additional markers may be required under grazing conditions in botanically diverse vegetation. This study was conducted to describe the n-alkane profiles and the carbon isotope enrichment of n-alkanes of common plant species from the Mid Rift Valley rangelands of Ethiopia, and evaluate their potential use as nutritional markers. A total of 23 plant species were collected and analysed for long-chain n-alkanes ranging from heptacosane to hexatriacontane (C(27) to C(36)), as well as their carbon isotopic ratio ((13)C/(12)C). The analysis was conducted by gas chromatography/combustion isotope ratio mass spectrometry following saponification, extraction and purification. The isotopic composition of the n-alkanes is reported in the delta notation (δ(13)C) relative to the Vienna Pee Dee Belemnite standard. The dominant n-alkanes in the species were C(31) (mean ± s.d., 283 ± 246 mg/kg dry matter) and C(33) (149 ± 98 mg/kg dry matter). The carbon isotopic enrichment of the n-alkanes ranged from -19.37‰ to -37.40‰. Principal component analysis was used to examine interspecies differences based on n-alkane profiles and the carbon isotopic enrichments of individual n-alkanes. Large variability among the pasture species was observed. The first three principal components explained most of the interspecies variances. Comparison of the principal component scores using orthogonal procrustes rotation indicated that about 0.84 of the interspecies variances explained by the two types of data sets were independent of each other, suggesting that the use of a combination of the two markers can improve diet composition estimations. It was concluded that, while the n-alkane profile of the pasture species remains a useful marker for use in the study region, the δ(13)C values of n-alkanes can provide additional information in discriminating diet components of grazing animals.

Determination of aetiology of superficial enlarged lymph nodes using fine needle aspiration cytology.

OBJECTIVE: To asses the causes and patterns of enlarged superficial lymph nodes. DESIGN: Cross sectional survey. SETTING: Jimma Teaching Hospital, Pathology Department, Jimma University, Southwest Ethiopia for a study conducted between September 1999 and August 2001. PARTICIPANTS: Eight hundred and eight patients presenting with enlarged superficial lymph nodes in cervical, axillary, inguinal etc. regions were included (456 males and 352 females) whereas non lymph node samples and deep-seated lymphoid lesions were excluded from the study. MAIN OUTCOME MEASURES: Fine needle aspiration cytology (FNAC) technique and Wright's staining procedure were utilized to diagnose the causes of enlarged lymph nodes. RESULTS: Of the 1693 patients attended to at the cytologic diagnostic service, 808(47.7%) had lymph node disorders with benign and malignant causes of lymph node enlargements comprising of 93.2% and 6.8% respectively. The most frequent cause of benign enlargement was tuberculous lymph adenities (66.3%), followed by reactive lymph node hyperplasia (19.2%). Among malignant ones, non-Hodgkin's lymphomas (2.7%) and metastatic carcinomas (2.2%) were most frequently diagnosed. The cervical region was the most frequent site for enlarged lymph node disorders accounting for more than three quarters of all cases. CONCLUSION: This study revealed a huge burden of benign lymph node enlargements in general, and tuberculous lymph adenities in particular. The latter was responsible for about two-third of lymph node enlargements in South Western parts of this country. It is recommended that health providers undertake intensive public health education and screening activities in order to help salvage our community from these potentially preventable and treatable causes of enlarged lymph node disorders.

Fine needle aspiration cytology of suspected tuberculous lymphadenitis.

Fine needle aspiration cytology of suspected tuberculous lymphadenitis The aims of this cross-sectional study were to describe the distributional patterns of tuberculous lymphadenitis and to assess the correlation between fine needle aspiration cytology (FNAC) and the Ziehl Neelsen staining technique in diagnosing tuberculous lymphadenitis. Romanowsky's method (Wright's stain) for cytological diagnosis and Ziehl Neelsen (hot method) for the identification of acid-fast bacilli were utilized. Out of one hundred and twenty-eight consecutive patients attending the cytological diagnostic service of the Department of Pathology within Jimma University, 89 (69.6%) of the patients were younger than 30 years of age. The male to female ratio was 1.3 : 1. The cervical region was the most common site and involved 95 cases (74.2%), followed by the axillary and inguinal lymph node regions (20.3% and 4.3%, respectively). The Wright's-stained cytology smears were grouped into three categories: epithelioid granulomas without necrosis, epithelioid granulomas with caseous necrosis and necrosis without epithelioid granulomas. The Ziehl Neelsen stains were undertaken on separate slides: 20.0% of the cases showing epithelioid granulomas without necrosis, 61.9% of those with epithelioid granulomas with necrosis/abscesses and 69.7% of those with necrosis without granulomas were found to be positive for acid-fast bacilli. The overall positivity for the ZiehlNeelsen stained cases was 59.4%. It can therefore be concluded that FNAC is a reliable diagnostic tool in helping to avert the more invasive surgical procedures undertaken in the diagnosis of tuberculous adenitis. The ZiehlNeelsen stain for identification of acid-fast bacilli should be incorporated as an adjunct to increase the diagnostic accuracy of tuberculous lymphadenitis.

Antiplasmodial and antioxidant isofuranonaphthoquinones from the roots of Bulbine capitata.

The roots of B. capitata yielded the new compounds 5,8-dihydroxy-1-tigloylmethylnaphtho[2,3-c]furan-4,9-dione, 1-acetoxymethyl-8-hydroxynaphtho[2,3-c]furan-4,9-dione, and 1-acetoxymethyl-5,8-dihydroxynaphtho[2,3-c]furan-4,9-dione, in addition to the known compounds chrysophanol, 10,10'-chrysophanol bianthrone, 8-hydroxy-1-methylnaphtho[2,3-c]furan-4,9-dione, 5,8-dihydroxy-1-methylnaphtho[2,3-c]furan-4,9-dione, 5,8-dihydroxy-1-hydroxymethylnaphtho[2,3-c]furan-4,9-dione, and 8-hydroxy-5-methoxy-1-methylnaphtho[2,3-c]furan-4,9-dione, or 5-hydroxy-8-methoxy-1-methylnaphtho[2,3-c]furan-4,9-dione. The new as well as the known isofuranonaphthoquinones showed antioxidant and weak antiplasmodial activities.

Cytological diagnosis of soft tissue tumours.

Cytological diagnosis of soft tissue tumours The aims of this study were to determine the patterns of soft tissue tumours and also to try to assess the utility of fine needle aspiration cytology (FNAC) in diagnosing soft tissue tumours. Of 15 361 patients who visited the cytology diagnostic service of the Pathology Department, Medical Faculty, Addis Ababa University, 623 (4.1%) cases with a diagnosis of soft tissue tumours were retrieved from the department's records for the years 1991-96. Fifty-three soft tissue tumours (25 benign and 28 malignant tumours) with combined FNAC and surgical biopsy results were traced for cyto-histological correlations. Twenty-two out of 25 benign soft tissue tumours were correctly diagnosed, with three false cytologic diagnoses where one mesenchmal neoplasm, one haemangioma, and one haemorragic lesion were identified; and out of 28 malignant soft tissue, 23 were correctly diagnosed however, the five false cytological diagnoses were one soft tissue sarcoma, one dermatofibrosarcoma, one malignant mesenchymal neoplasm, one spindle cell neoplasm and one menechymal neoplasm. Thus, in this study a sensitivity and specificity of 88.5% and 81.5% respectively for the diagnosis of soft tissue tumours were reported. In conclusion, FNAC of soft tissue tumours is a fast, effective and reliable diagnostic tool that may help in categorizing soft tissue tumours into benign and malignant groups for clinical management.

Antiplasmodial activity of knipholone and related natural phenylanthraquinones.

phenylanthraquinone knipholone (1) and three of its natural derivatives as well as seven structurally related but simplified compounds have been examined for their antiplasmodial activity against asexual erythrocytic stages of two strains of Plasmodium falciparum in vitro (K1/chloroquine-resistant and NF 54/chloroquine-sensitive). All the phenylanthraquinones showed considerable activity with only little cytotoxicity, while their anthraquinone and phenyl moieties were completely inactive. Knipholone (1) and its natural derivatives can therefore be considered as a new group of potential antimalarials