Splenic smooth-muscle tumors in children with acquired immunodeficiency syndrome: report of two cases of this unusual location with evidence of an association with Epstein-Barr virus

Smooth-muscle neoplasms are rarely located in the spleen. They have been previously reported in five cases of children with human immunodeficiency virus (HIV) infection/acquired immunodeficiency syndrome (AIDS). Two cases of children with HIV infection/AIDS with autopsy and surgical pathology evidence of multiple smooth-muscle neoplasms with splenic involvement are presented. DNA was extracted from histology slides in both cases for analysis for Epstein Barr (EB) virus. In both cases, the presence of EB virus was confirmed. This paper documents two additional cases of the unusual phenomenon of splenic involvement by smooth-muscle neoplasms in the setting of AIDS in childhood and further supports the role of EB virus in the development of these neoplasms. Received: 27 January 1999 / Accepted: 23 August 1999     

Comparative analysis of macrophage migration inhibitory factors (MIFs) from the parasitic nematode Onchocerca volvulus and the free-living nematode Caenorhabditis elegans

The macrophage migration inhibitory factors (MIFs) from the filarial parasite Onchocerca volvulus (OvMIF) were compared to the MIFs from the free-living nematode Caenorhabditis elegans (CeMIF) with respect to molecular, biochemical and immunological properties. Except for CeMIF-4, all other MIFs demonstrated tautomerase activity. Surprisingly, OvMIF-1 displayed oxidoreductase activity. The strongest immunostaining for OvMIF-1 was observed in the outer cellular covering of the adult worm body, the syncytial hypodermis; moderate immunostaining was observed in the uterine wall. The generation of a strong humoral immune response towards OvMIF-1 and reduced reactivity to OvMIF-2 was indicated by high IgG levels in patients infected with O. volvulus and cows infected with the closely related Onchocerca ochengi, both MIFs revealing identical amino acid sequences. Using Litomosoides sigmodontis-infected mice, a laboratory model for filarial infection, MIFs derived from the tissue-dwelling O. volvulus, the rodent gut-dwelling Strongyloides ratti and from free-living C. elegans were recognized, suggesting that L. sigmodontis MIF-specific IgM and IgG1 were produced during L. sigmodontis infection of mice and cross-reacted with all MIF proteins tested. Thus, MIF apparently functions as a target of B cell response during nematode infection, but in the natural Onchocerca-specific human and bovine infection, the induced antibodies can discriminate between MIFs derived from parasitic or free-living nematodes.     

Androgen receptors in cultured rat adipose precursor cells during proliferation and differentiation: regional specificities and regulation by testosterone

Different studies suggest that sex hormones affect adipose tissue metabolism and deposition. To investigate the possibility that androgens may play a role in adipose tissue development, we have studied androgen receptors (AR) in rat adipose precursor cells from two different anatomical fat deposits, one deep intraabdominal (epididymal) and one subcutaneous (inguinal) during the proliferation and differentiation processes. AR were quantified by [³H]R1881 specific binding in whole cells and the nuclear fraction and were localized by immunocytofluorimetry in both the cytosol and the nucleus. During the proliferative phase, total AR level decreased from D3 to D6. At confluence (D5), AR were higher in epididymal (64±4 fmol/mg protein) than in subcutaneous (33±3 fmoles/mg proteins) preadipocytes and were up-regulated by testosterone but not by 5α-dihydrotestosterone or by 17β-estradiol. At differentiation (D10-11), nuclear AR decreased by 50% in both precursor fat cell populations when compared to the confluent state (D5) and AR were no more up-regulated but rather down-regulated by testosterone. Because AR are present in preadipocytes and are differently regulated by testosterone depending on the stage of proliferation and differentiation, this study suggests that testosterone may play a role in the control of the adipogenic process.     

Hypoglycaemic properties of the aqueous root extract of Morinda lucida (Benth) (Rubiaceae). Studies in the mouse

The aqueous root extract of Morinda lucida (Rubiaceae) Benth, exhibited potent hypoglycaemic effects in both normoglycemic and alloxan-induced diabetic mice by oral administration. This effect was dose-dependent and more potent than that observed with chlorpropamide (1-(p-chlorobenzene-sulphanyl)-3-propylurea). In the normoglycaemic mice, the extract (140 mg/kg body weight) produced a fall in blood sugar of 32% + 1% while at 280 mg/kg body weight there was a 52% + 2% fall over the same time interval. In alloxan-induced diabetic mice, the reaction time of the extract was longer with a single dose of the extract producing a significant hypoglycaemic effect 4 h after administration. In diabetic mice, a dose of 140 mg/kg body weight of the plant extract caused a fall in blood sugar of 51% + 1% while a dose of 280 mg/kg produced a fall of 60% + 2%.     

The distribution of anti-Salmonella antibodies in the sera of blood donors in Yaoundé, Cameroon

This cross-sectional study in late 1996 on a group of 230 consecutive blood donors in Yaoundé, Cameroon, found a baseline titre of 1:100 for antisalmonella O antibodies. The seroprevalence and baseline titre for antisalmonella H antibodies was much higher (1:400), suggesting that the H antibody is of limited diagnostic value in Cameroon.     

Estrogenic activity of griffonianone C, an isoflavone from the root bark of Millettia griffoniana: regulation of the expression of estrogen responsive genes in uterus and liver of ovariectomized rats

Griffonianone C (Griff C) is an isoflavone produced by Millettia griffoniana (Bail) and exhibits estrogenic properties in in vitro reporter gene assays. In order to validate its estrogenic potency in vivo, we administered subcutaneously Griff C (2, 10, or 20 mg/kg/d BW), 17beta-estradiol (10 microg/kg/d BW) as positive control, and a vehicle control to ovariectomized Wistar rats. After three consecutive days of treatment animals were sacrificed 24 hours after receiving the last dose. The uteri and livers were excised, weighed and stored for mRNA expression analysis by real-time PCR. The uterine wet weight was not significantly increased by Griff C, although there was a trend towards an increase. In contrast, 17beta-estradiol increased uterine wet weight 4.5-fold in comparison to the vehicle control. However, as revealed by real-time PCR Griff C affected the expression of estrogen-responsive genes in uterus and liver of ovariectomized rats. E2 induced a 550-fold stimulation of uterine C3 mRNA expression. Griff C at the dose 20 mg/kg/d BW caused a 50-fold up-regulation of complement C3 mRNA compared to the control. A significant increase in calcium binding protein 9-kilodalton mRNA expression was observed in the uterus of ovariectomized rats treated with E (2) (41-fold versus control) or 20 mg/kg/d BW of Griff C (25-fold versus control). In contrast, the expression of clusterin and progesterone receptor in the uterus was strongly decreased by both E2 and Griff C at the highest dose. We also found a repression of clusterin mRNA in the liver while carbonic anhydrase 2 and major acute phase protein were slightly up-regulated. In conclusion, Griff C showed a clear estrogenic action on uterine and hepatic tissues of ovariectomized rats, although its effect was less than the effect of estradiol. This suggests that some of the biological effects attributed to Millettia griffoniana are probably related to estrogen-mediated function.     

Protein tyrosine phosphatase-1B inhibitory activity of isoprenylated flavonoids isolated from Erythrina mildbraedii

Inhibition of protein tyrosine phosphatase-1B (PTP1B) has been proposed as a therapy for treatment of type-2 diabetes and obesity. Bioassay-guided fractionation of an EtOAc-soluble extract of the root bark of Erythrina mildbraedii, using an in vitro PTP1B inhibitory assay, resulted in the isolation of three new isoprenylated flavonoids, abyssinone-IV-4'-O-methyl ether (2), 7-hydroxy-4'-methoxy-3'-(3-hydroxy-3-methyl-trans-but-1-enyl)-5'-(3-methylbut-2-enyl)flavanone (3), and abyssinone-VI-4-O-methyl ether (6), along with six known flavonoids, abyssinone-V-4'-O-methyl ether (1), abyssinone-V (4), abyssinone-IV (5), sigmoidin E (7), 4'-hydroxy-5,7-dimethoxyisoflavone (8), and alpinumisoflavone (9). Compounds 1 and 2, 4-7, and 9 inhibited PTP1B activity, with IC50 values ranging from 14.8 +/- 1.1 to 39.7 +/- 2.5 microM. On the basis of the data obtained, flavanones and chalcones with isoprenyl groups may be considered as a new class of PTP1B inhibitors.