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Biomedical subjects

A Brauman

Publications and source records attributed to A Brauman.

At least 19 recordsLinked to original sources
PubMed2004

Bacterial density and community structure associated with aggregate size fractions of soil-feeding termite mounds.

The building and foraging activities of termites are known to modify soil characteristics such as the heterogeneity. In tropical savannas the impact of the activity of soil-feeding termites ( Cubitermes niokoloensis) has been shown to affect the properties of the soil at the aggregate level by creating new soil microenvironments (aggregate size fractions) [13]. These changes were investigated in greater depth by looking at the microbial density (AODC) and the genetic structure (automated rRNA intergenic spacer analysis: ARISA) of the communities in the different aggregate size fractions (i.e., coarse sand, fine sand, coarse silt, fine silt, and dispersible clays) separated from compartments (internal and external wall) of three Cubitermes niokoloensis mounds. The bacterial density of the mounds was significantly higher (1.5 to 3 times) than that of the surrounding soil. Within the aggregate size fractions, the termite building activity resulted in a significant increase in bacterial density within the coarser fractions (>20 mum). Multivariate analysis of the ARISA profiles revealed that the bacterial genetic structures of unfractionated soil and soil aggregate size fractions of the three mounds was noticeably different from the savanna soil used as a reference. Moreover, the microbial community associated with the different microenvironments in the three termite mounds revealed three distinct clusters formed by the aggregate size fractions of each mound. Except for the 2-20 mum fraction, these results suggest that the mound microbial genetic structure is more dependent upon microbial pool affiliation (the termite mound) than on the soil location (aggregate size fraction). The causes of the specificity of the microbial community structure of termite mound aggregate size fractions are discussed.

Acridine Orange↗
PubMed2001

Molecular phylogenetic profiling of prokaryotic communities in guts of termites with different feeding habits.

Termites are an important group of terrestrial insects that harbor an abundant gut microbiota, many of which contribute to digestion, termite nutrition and gas (CH(4), CO(2) and H(2)) emission. With 2200 described species, termites also provide a good model to study relationships between host diet and gut microbial community structure and function. We examined the relationship between diet and gut prokaryotic community profiles in 24 taxonomically and nutritionally diverse species of termites by using nucleic acid probes targeting 16S-like ribosomal RNAs. The relative abundance of domain-specific 16S-like rRNAs recovered from gut extracts varied considerably (ranges: Archaea (0-3%); Bacteria (15-118%)). Although Bacteria were always detectable and the most abundant, differences in domain-level profiles were correlated with termite diet, as evidenced by higher relative abundances of Archaea in guts of soil-feeding termites, compared to those of wood-feeding species in the same family. The oligonucleotide probes also readily distinguished gut communities of wood-feeding taxa in the family Termitidae (higher termites) from those of other wood-feeding termite families (lower termites). The relative abundances of 16S-like archaeal rRNA in guts were positively correlated with rates of methane emission by live termites, and were consistent with previous work linking high relative rates of methanogenesis with the soil (humus)-feeding habit. Probes for methanogenic Archaea detected members of only two families (Methanobacteriaceae and Methanosarcinaceae) in termite guts, and these typically accounted for 60% of the all archaeal probe signal. In four species of termites, Methanosarcinaceae were dominant, a novel observation for animal gut microbial communities, but no clear relationship was apparent between methanogen family profiles and termite diet or taxonomy.

Journal Article↗
PubMed1998

Fermentative degradation of 3-hydroxybenzoate in pure culture by a novel strictly anaerobic bacterium, Sporotomaculum hydroxybenzoicum gen. nov., sp. nov.

A strictly anaerobic bacterium, strain BT, from termite hindgut homogenates, was isolated in pure culture and grew on 3-hydroxybenzoate as sole source of carbon and energy. No other substrate tested was degraded, sulfate, sulfite, thiosulfate, nitrate, ferric iron, oxygen or fumarate were not reduced, and no electron transfer to partner organisms was observed. 3-Hydroxybenzoate was fermented to butyrate, acetate and CO2. Benzoate was detected in the culture supernatant as an intermediate. The isolate was a slightly motile, endosporeforming Gram-positive rod; 16S rDNA sequence analysis revealed a high similarity to members of the genus Desulfotomaculum. The G + C content of the DNA was 48 mol%. Strain BT differs from the members of the genus Desulfotomaculum significantly due to its lack of dissimilatory sulfate reduction, and is therefore described as the type strain of a new genus and species. Sporotomaculum hydroxybenzoicum gen. nov., sp. nov.

Animals↗
PubMed1996

Microbiological and biochemical characterization of cassava retting, a traditional lactic Acid fermentation for foo-foo (cassava flour) production.

The overall kinetics of retting, a spontaneous fermentation of cassava roots performed in central Africa, was investigated in terms of microbial-population evolution and biochemical and physicochemical parameters. During the traditional process, endogenous cyanogens were almost totally degraded, plant cell walls were lysed by the simultaneous action of pectin methylesterase and pectate lyase, and organic acids (C(inf2) to C(inf4)) were produced. Most microorganisms identified were found to be facultative anaerobes which used the sugars (sucrose, glucose, and fructose) present in the roots as carbon sources. After 24 h of retting, the fermentation reached an equilibrium that was reproducible in all the spontaneous fermentations studied. Lactic acid bacteria were largely predominant (over 99% of the total flora after 48 h) and governed the fermentation. The epiphytic flora was first replaced by Lactococcus lactis, then by Leuconostoc mesenteroides, and finally, at the end of the process, by Lactobacillus plantarum. These organisms produced ethanol and high concentrations of lactate, which strongly acidified the retting juice. In addition, the rapid decrease in partial oxygen pressure rendered the process anaerobic. Strict anaerobes, such as Clostridium spp., developed and produced the volatile fatty acids (mainly butyrate) responsible, together with lactate, for the typical flavor of retted cassava. Yeasts (mostly Candida spp.) did not seem to play a significant role in the process, but their increasing numbers in the last stage of the process might influence the flavor and the preservation of the end products.

Journal Article↗
PubMed1990

Characterization of two sulfate-reducing bacteria from the gut of the soil-feeding termite, Cubitermes speciosus.

Two sulfate-reducing bacteria (SRB) were isolated from a mixed culture enriched with benzoate obtained from gut homogenate of the soil-feeding higher termite, Cubitermes speciosus. The organisms were vibrioid rods, staining Gram-negative, which performed incomplete substrate oxidation. They differed in several features. The smaller one, strain STp, was motile with a single polar flagellum. This strain differed from Desulfovibrio desulfuricans only by its inability to oxidize malate and pentanol. The bigger one, strain STg, differed from Desulfovibrio giganteus only by its nonmotility and a lower length. It is the first evidence of the presence of SRB in termite gut.

Animals↗
PubMed1988

Prevalence of mitral valve prolapse in chronic lymphocytic thyroiditis and nongoitrous hypothyroidism.

An increased prevalence of mitral valve prolapse has been found in Graves' disease and a common autoimmune etiology has been suggested for both disorders. We investigated the prevalence of mitral valve prolapse in 87 patients with autoimmune chronic lymphocytic thyroiditis, 50 patients with nongoitrous hypothyroidism and 111 healthy control subjects. Mitral valve prolapse was found in 16.09% of patients with chronic lymphocytic thyroiditis compared to 6 and 5.4% in nongoitrous hypothyroidism and normal controls, respectively. The result is statistically significant, p less than 0.02, and confirms that the prevalence of mitral valve prolapse is significantly increased in patients with autoimmune disorders of the thyroid gland, when compared to normals and nonautoimmune conditions.

Adult↗
PubMed1987

Recurrent pulmonary atelectasis as a manifestation of familial Mediterranean fever.

Recurrent attacks of pulmonary atelectasis were the leading sign of familial Mediterranean fever in a young man of Jewish-Georgian extraction. His mother suffered from the more common manifestations of the disease. Treatment with colchicine caused a complete disappearance of his attacks. However, when challenged by discontinuing colchicine therapy for eight days, another, documented attack of pulmonary atelectasis occurred. To our knowledge, this is the first case of familial Mediterranean fever presenting with recurrent pulmonary atelectasis.

Adult↗
PubMed1986

Methane Production from Formate by Syntrophic Association of Methanobacterium bryantii and Desulfovibrio vulgaris JJ.

Coculture of a sulfate-reducing bacterium, when grown in the absence of added sulfate, with Methanobacterium bryantii, which uses only H(2) and CO(2) for methanogenesis, degraded formate to CH(4). A pure culture of Desulfovibrio vulgaris JJ was able to produce small amounts of H(2). Such a syntrophic relationship might provide an additional way to avoid formate accumulation in anaerobic environments.

Journal Article↗
PubMed1985

Mitral valve prolapse in hyperthyroidism of two different origins.

The prevalence of mitral valve prolapse was investigated in 126 patients with hyperthyroidism due to Graves' disease or toxic nodular goitre and that of hyperthyroidism in 64 patients with mitral valve prolapse. One hundred and eleven asymptomatic healthy subjects comprised a control group. The patients with hyperthyroidism were divided into those with Graves' disease and those with toxic nodular goitre. Of the group as whole, 12 (9.5%) patients had mitral valve prolapse compared with six (5.4%) in the control group, but the difference was not statistically significant. The prevalence of mitral valve prolapse in the patients with toxic goitre was also not significantly different from that in the controls. When the prevalence in the group with Graves' disease was compared with that in the control group (16.3% vs 5.4%) the difference was significant. Only one patient with mitral valve prolapse had hyperthyroidism.

Adult↗
PubMed1985

Primary fibroxanthosarcoma of the kidney presenting as fever of unknown origin.

Fibroxanthosarcoma is a tumor of soft tissues, mainly effecting the extremities, mediastinum and retroperitoneum. Primary fibroxanthosarcoma of the kidney is extremely rare and has been described in only 4 cases in the past. We present an additional patient, presenting with continuous spiking fever, with rapid deterioration of her condition due to widespread metastases and death within 4 months.

Female↗
PubMed1984

Double pylorus or antro-bulbar fistula.

A patient suffering from rheumatoid arthritis and a gastric ulcer was found endoscopically to have a double pylorus. One year later the two apertures were found to be fused and appeared endoscopically like a deformed pylorus. We suggest that this lesion, which is usually acquired but may sometimes be congenital, would be better called antro-bulbar fistula.

Adult↗