Paediatric tuberculosis at the national teaching hospital CNHU-HKM of Cotonou, Benin: a retrospective study.

UNLABELLED: BACKGROIUND: Tuberculosis (TB) is a public health problem. Knowing its patterns could help address it more efficiently. OBJECTIVE: To determine the hospital incidence, presentation, management, and outcome of TB in our setting. METHODS: We conducted a chart review of children with TB during a five-year period at the University Hospital CNHU-HKM, Cotonou, Benin. RESULTS: Hospital prevalence of TB among hospitalised children was 0.2%. The mean age was six years, with a male:female ratio of 1.4:1. The common clinical features were: cough (78.1%), long standing fever (81.2%), growth retardation (65.6%), pulmonary consolidation (53.1%) and hepatosplenomegaly (34.4%). The skin tuberculin test was positive in only 40.6% of cases. Co-infection with HIV was present in 51.8% of cases. Mycobacterium tuberculosis could be identified in only 21.8% of cases. Twenty-six (81.2%) pulmonary tuberculosis (PTB) cases were diagnosed, eight (25%) of which were associated with extra pulmonary TB. Six (18.7%) presumed isolated extra PTB were also diagnosed. Eight-month treatment regimen was used in most patients, with mortality rate of 9.3%. CONCLUSION: Although TB hospital prevalence seems low in our setting, management needs to be improved according to guidelines.

The nuclear oxysterol receptor LXRalpha is expressed in the normal human breast and in breast cancer.

The liver X> or = receptor alpha (LXRalpha) is a nuclear receptor with a key role in bile acid biosynthesis and cholesterol metabolism. The present study investigated the expression and function of LXRalpha in the normal and malignant human breast. LXRalpha mRNA transcripts were detected by RT-PCR in nine breast carcinoma cell lines. The nucleotide sequence of the cloned PCR product was identical to the corresponding human LXRalpha cDNA sequence. Expression of LXRalpha protein was confirmed by immunoblot analysis of breast cancer cell lysates. LXRalpha mRNA was expressed in 14/15 (93%) of normal human breast mammoplasty specimens and in 11/15 (73%) of primary breast carcinomas. Oxysterol and nonsteroidal LXRalpha agonists at low micromolar concentrations inhibited proliferation of breast carcinoma cell lines in culture. The importance of LXRalpha signaling in cholesterol homeostasis and the observed expression of LXRalpha in normal breast tissue suggest that this nuclear oxysterol receptor has an important physiological function in the breast. LXRalpha gene expression is regulated by dietary fatty acids implicated in breast carcinogenesis and detection of LXRalpha expression in breast cancer cell lines and breast tumors in the present study indicates that LXRalpha may also be important in breast carcinogenesis. Inhibition of breast cancer cell proliferation suggests that pharmacological LXRalpha agonists may have potential preventive and/or therapeutic antitumor activity in breast cancer.

Plasma pharmacokinetics and metabolism of the histone deacetylase inhibitor trichostatin a after intraperitoneal administration to mice.

Trichostatin A is a potent and specific histone deacetylase inhibitor with promising antitumor activity in preclinical models. Plasma pharmacokinetics of trichostatin A were studied following single-dose intraperitoneal administration of 80 mg/kg (high dose) or 0.5 mg/kg (low dose) to female BALB/c mice. Plasma trichostatin A concentrations were quantified by high performance liquid chromatography (HPLC)-UV assay (high dose) or by HPLC-multiple reaction monitoring assay (low dose). Trichostatin A was rapidly absorbed from the peritoneum and detectable in plasma within 2 min. Cmax of 40 microg/ml and 8 ng/ml occurred within 5 min, followed by rapid exponential decay in plasma trichostatin A concentration with t1/2 of 6.3 min and 9.6 min (high and low doses, respectively). Phase I metabolites at the high dose were identified by simultaneous UV and positive ion electrospray mass spectrometry. Trichostatin A underwent extensive metabolism: primary metabolic pathways were N-demethylation, reduction of the hydroxamic acid to the corresponding trichostatin A amide, and oxidative deamination to trichostatic acid. N-Monomethyl trichostatin A amide was the major plasma metabolite. No didemethylated compounds were identified. Trichostatic acid underwent further biotransformation: reduction and beta-oxidation of the carboxylic acid, with or without N-demethylation, resulted in formation of dihydro trichostatic acid and dinor dihydro trichostatic acids. HPLC fractions corresponding to trichostatin A and N-demethylated trichostatin A exhibited histone deacetylase-inhibitory activity; no other fractions were biologically active. We conclude that trichostatin A is rapidly and extensively metabolized in vivo following intraperitoneal administration to mice, and N-demethylation does not compromise histone deacetylase-inhibitory activity.

The CDKN2A tumour suppressor gene: no mutations detected in patients with melanoma and additional unrelated cancers.

Germ-line mutations of the CDKN2A tumour suppressor gene have been reported in association with familial melanoma, sporadic melanoma with multiple primary lesions and also pancreatic cancer. We studied the hypothesis that patients with melanoma and additional unrelated cancers may harbour mutations in the CDKN2A gene. Twenty seven patients with histologically confirmed melanoma who also had additional cancers such as breast, colorectal, lymphoma and other neoplasms were studied. We also examined 17 additional patients, 13 of whom had a first-degree relative with melanoma and four who had two or more primary melanomas. Some patients belonged to more than one of these categories. No mutations of the CDKN2A tumour suppressor gene were detected among patients with melanoma and additional cancers. The previously described Met53Ile CDKN2A mutation located in exon 2 was detected in a female patient with melanoma metastatic to the regional lymph nodes, multiple primary cutaneous lesions, atypical naevi and a first-degree relative with melanoma. The studied cohort is too small for firm conclusions. However, it would appear that melanoma and additional, apparently unrelated, cancers developing in the same individual are likely to be related to a combination of low-risk susceptibility genes and environmental factors.

S100A6, a calcium- and zinc-binding protein, is overexpressed in SOD1 mutant mice, a model for amyotrophic lateral sclerosis.

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease characterised by selective degeneration of motoneurones. Familial ALS is an age-dependent autosomal dominant disorder in which mutations in the homodimeric enzyme Cu/Zn superoxide dismutase 1 (SOD1) is linked to the disease. An animal model for this disease is a transgenic mouse expressing the mutated human SOD1(G93A) gene. Recent electrophysiological data emphasised that the striking selective vulnerability of motoneurones might be due to their differential calcium buffering capacities. Therefore we have investigated, using immunohistochemistry, the expression of different calcium binding proteins in brainstem and spinal cord from normal and SOD1 mutated mice. Among the 13 calcium-binding proteins screened, only one, S100A6, a homodimeric calcium-binding protein able to bind four Zn(2+), appeared to be highly expressed in the SOD1 mutated mice. In brainstem, reactive astrocytes, but not motoneurones, from several regions, including nerve 12 root, were highly S100A6-positive. Hypoglossal nucleus was negative for S100A6. In dorsal root, reactive astrocytes from both white matter and anterior horn were highly reactive. If overexpression of S100A6 is specific for ALS, it will be a valuable diagnostic marker for this disease.

Detection of tyrosinase mRNA by RT-PCR in the peripheral blood of patients with advanced metastatic melanoma.

Detection of melanoma cells in the peripheral blood has been facilitated by the reverse transcriptase-polymerase chain reaction (RT-PCR), but their presence is of uncertain importance in the evolution of the disease. We studied the detection of melanoma cells using RT-PCR in the peripheral blood of 21 patients, four with regional lymph node metastases (American Joint Committee on Cancer [AJCC] stage III) and 17 with disseminated disease (AJCC stage IV). RNA was extracted from 10 ml of heparinized blood following density gradient centrifugation and converted into cDNA for PCR analysis. Assay sensitivity of 10 cells in 10(7) mononuclear cells and granulocytes obtained from 10 ml of peripheral blood was achieved using the G361 and C32 melanoma cell lines. Tyrosinase mRNA was not detected in control samples from healthy volunteers or patients with non-malignant disease. Six patients (one stage III, five stage IV) tested positive for tyrosinase mRNA (28.6%); with one exception, all patients were receiving chemotherapy at the time of sampling. Of the six positive results, three were from patients who initially tested negative but were subsequently positive after a 3-4 week interval. The low detection rates of melanoma cells in the peripheral blood of patients with widely disseminated disease is consistent with recent reports and correlates poorly with the clinical stage of melanoma. This may be partly explained by the clinically observed intermittent and random evolution of melanoma metastases.

Changes in albumoid protein during cataract formation.

The water-insoluble albumoid protein of the human cataractous lenses was extracted in Tris/glycine buffer (pH 8.2). Subsequent homogenization in 8 M urea containing 1% beta-mercaptoethanol gave three major fractions: urea soluble fraction (USF), urea beta-mercaptoethanol-soluble fraction (U-beta-merc-IF). and urea beta-mercaptoethanol-soluble fraction (U-beta-merc-SF). The urea beta-mercaptoethanol-soluble fraction (U-beta-merc-SF) constitutes the pigmented protein of the human cataractous lenses. The amino-acid composition indicates the presence of tryptophan, high concentration of cysteine and low concentration of lysine and methionine. The brown protein is an aggregate of protein subunits which may be a protein chromophore, that directs all possible adaptive phenomenon during vision.

Biochemical frontiers of fibrosis: concepts and perspectives.

The inhibition of Fibrotic lesion are classified into two: specific and nonspecific inhibition. The specific inhibition is based on the chemistry and metabolism of collagen, whereas the nonspecific inhibition is viewed from the point of the fibro-proliferative inflammation preceding fibroblasts activation. A brief account is given on existing as well as perspective methods to present a frame work for a concept on pharmacology of fibrosis.

Variations in the soluble alpha-crystallin proteins from human cataractous lenses.

Human cataractous lenses from subjects aged 20-91 years were extracted in tris/glycine buffer and fractionated on Sephadex G-75 column. Four fractions, F1, F2, F3 and F4 identified as alpha-, beta1-, beta2- and gamma-crystallin were obtained. Gel electrophoresis of alpha-crystallin in polyacrylamide containing 6M urea revealed changes in polypeptide composition, colouration; variation in band pattern and mean mobility. The relative mobilities of the protein bands were used to calculate coefficient of similarity within the same age group and among different age groups.

Carbohydrate composition of the human cataractous lenses.

Specific chemical assays, including carbohydrate, hexosamines and hexuronic acid, were determined on the lens insoluble albumoid. It was noticed that the carbohydrate composition varies with age. The significance of carbohydrate in the lens is discussed.