Histological study on the effect of aflatoxin B1 on the renal tubules of adult rats

Aflatoxins are secondary metabolites of the fungi Aspergillusflavus and Aspergillus parasiticus. These species are prevalent in food crops, particularly in maize, groundnuts, and oilseeds. Chronic aflatoxin exposure is associated with damage to the kidney. The aim of this study was to investigate the effect of aflatoxin B1 on the renal tubules of female albino rats using light and electron microscopy. Thirty adult female rats were used in this study. They were divided into two groups. The first group was considered the control group. The second group was given 0.05 microg/kg aflatoxin orally every week for 8 consecutive weeks. At the end of the experiment the animals were sacrificed and specimens of the kidneys were extracted and processed for light and electron microscopy. In the aflatoxin-treated group there were necrosis and sloughing of the proximal convoluted tubules in some areas; other areas showed mitotic division and cell crowding. Ultramicroscopic results revealed cytoplasmic vacuolations, scanty mitochondria, and widely spaced microvilli. The distal convoluted tubules showed loss of cell polarity and basolateral infoldings. The interstitium was wide, edematous, and contained congested blood capillaries and a few mononuclear cells. Aflatoxin had a cytotoxic effect on the renal tubules of albino rats. Regulations should be implemented to avoid the presence of aflatoxins in high concentrations in human food and minimize their negative effects on agriculture and health

Isolation of cryptococcus, candida, aspergillus, rhodotorula and nocardia from meningitis patients in Egypt

Meningitis occurs throughout Egypt and is largely attributed to bacterial pathogens, but there is little information on fungal etiologies of meningitis. We, therefore, investigated fungal infections among Egyptian patients with acute and subacute meningitis who tested negative for bacterial and viral agents. A total of 1000 cerebrospinal fluid [CSF] samples collected from nine governorates of Egypt during 1998-2002 were initially stained with Gram's, India ink, and lacto-phenol cotton-blue stains, and examined under light microscope to detect fungal elements. All CSF samples were cultured on brain heart infusion, Wickerham and Staib agar media for fungus isolation. CSF with suspected Cryptococcus neoforntans infections were also tested by latex agglutination test for antigen detection. Species identification of selected isolates was carried out at the Mycotic Diseases Branch, CDC, Atlanta, Georgia, USA. Fungal agents were detected microscopically and by culture in 17 of 1000 [1.7%] CSF samples tested. Ten of 17 were identified as C. neoformans var grubii [serotype A], 4 as Candida albicans, and one each of Aspergillus candidus, Rhodotorula mucilaginosa [rubra] and Nocardia spp [actinomycetes]. Out of the 17 cases with fungal CSF infection, 8 died [Cryptococcus-3. Candida-2, AspergiUus, Rhodotorula and Nocardia] and 2 suffered neurological sequelae. Of the 10 cryptococcal meningitis patients, 4 were HIV positive and one was diagnosed with lymphoma. To our knowledge, this is the first study on isolation of fungi other than Cryptococcus from CSF of Egyptian patients with acute/subacute meningitis. Consideration must now be given to cryptococcosis and candidiasis as potential etiologies of meningitis in Egypt

Allergic broncho-pulmonary aspergillosis among asthmatic patients in Zagazig area

Aspergilli, especially A. fumigatus could cause a variety of allergic reactions. Extrinsic asthma to Aspergilli is prevalent in Sharkia Governorate. Out of 200 asthmatic patients, 115 [57.5%] were sensitive to one or two of Apergillus antigens [Mycelial mat extract and acetone precipitated culture filtrate]. Not all these patients responded well to hyposensitisation performed. When investigated it was found that 35 of them [17.5%] had precipitins by ID method. This group of patients with precipitins had also higher total oesinophilic count [x=931] and higher total Ig[E] [x=2129] and most of them had bronchiectasis [80%], +ve sputum culture to one or both of A. fumigatus or A. niger [68.6%]. All these data suggest that ABPA is not uncommon in asthmatic patients reactive to aspergillus species. Patients fullfilling the criteria of ABPA should be diagnosed since hyposensitisation will not benefit them, on the contrary it may aggravate the presence of precipitins and censequently the reaction of the lung