Gut integrity and duodenal enteropathogen burden in undernourished children with environmental enteric dysfunction

Environmental enteric dysfunction (EED) is a subclinical condition of intestinal inflammation, barrier dysfunction and malabsorption associated with growth faltering in children living in poverty. This study explores association of altered duodenal permeability (lactulose, rhamnose and their ratio) with higher burden of enteropathogen in the duodenal aspirate, altered histopathological findings and higher morbidity (diarrhea) that is collectively associated with linear growth faltering in children living in EED endemic setting. In a longitudinal birth cohort, 51 controls (WHZ > 0, HAZ > −1.0) and 63 cases (WHZ< -2.0, refractory to nutritional intervention) were recruited. Anthropometry and morbidity were recorded on monthly bases up to 24 months of age. Dual sugar assay of urine collected after oral administration of lactulose and rhamnose was assessed in 96 children from both the groups. Duodenal histopathology (n = 63) and enteropathogen analysis of aspirate via Taqman array card (n = 60) was assessed in only cases. Giardia was the most frequent pathogen and was associated with raised L:R ratio (p = 0.068). Gastric microscopy was more sensitive than duodenal aspirate in H. pylori detection. Microscopically confirmed H. pylori negatively correlated with HAZ at 24 months (r = −0.313, p = 0.013). Regarding histopathological parameters, goblet cell reduction significantly correlated with decline in dual sugar excretion (p< 0.05). Between cases and controls, there were no significant differences in the median (25^th, 75^th percentile) of urinary concentrations (μg/ml) of lactulose [27.0 (11.50, 59.50) for cases vs. 38.0 (12.0, 61.0) for controls], rhamnose [66.0 (28.0, 178.0) vs. 86.5 (29.5, 190.5)] and L:R ratio [0.47 (0.24, 0.90) vs. 0.51 (0.31, 0.71)] respectively. In multivariable regression model, 31% of variability in HAZ at 24 months of age among cases and controls was explained by final model including dual sugars. In conclusion, enteropathogen burden is associated with altered histopathological features and intestinal permeability. In cases and controls living in settings of endemic enteropathy, intestinal permeability test may predict linear growth. However, for adoption as a screening tool for EED, further validation is required due to its complex intestinal pathophysiology.     

Deciphering key genes in cardio-renal syndrome using network analysis

Cardio-renal syndrome (CRS) is a rapidly recognized clinical entity which refers to the inextricably connection between heart and renal impairment, whereby abnormality to one organ directly promotes deterioration of the other one. Biological markers help to gain insight into the pathological processes for early diagnosis with higher accuracy of CRS using known clinical findings. Therefore, it is of interest to identify target genes in associated pathways implicated linked to CRS. Hence, 119 CRS genes were extracted from the literature to construct the PPIN network. We used the MCODE tool to generate modules from network so as to select the top 10 modules from 23 available modules. The modules were further analyzed to identify 12 essential genes in the network. These biomarkers are potential emerging tools for understanding the pathophysiologic mechanisms for the early diagnosis of CRS. Ontological analysis shows that they are rich in MF protease binding and endo-peptidase inhibitor activity. Thus, this data help increase our knowledge on CRS to improve clinical management of the disease.     

The lateral supramalleolar flap

An anatomic study (40 fresh dissected specimens) and clinical experience (14 patients) have shown the reliability of a skin flap designed on the lower third of the lateral aspect of the leg. It is supplied by a cutaneous branch from the perforating branch of the peroneal artery. This perforating branch continues distally deep to the fascia along the anterior ankle and into the foot. This can be used as a reversed pedicle, giving the flap an arc of rotation that allows coverage of the dorsal, lateral, and plantar aspects of the foot, the posterior heel, and the lower medial portion of the leg.     

Investigations on some hybrids from theArabis hirsuta complex

Natural and artificial hybrids between the tetraploidArabis hirsuta (L.)Scop. s. str. and two diploid speciesA. sagittata (Bertol.) DC. orA. planisiliqua (Pers.)Reichenb. are the main subject of this paper. The investigations concern pollination behaviour, sterility, occurrence and frequency of hybrids, their morphology and cytology. Some questions concerning relations of the taxa within the complex and the significance of hybrids in the variability of natural mixed populations are discussed.     

Modes of coenzyme Q function in electron transfer

Summary In the mitochondrial respiratory chain, coenzyme Q acts in different ways. A diffusable coenzyme Q pool as a common substrate-like intermediate links the low-potential complexes with complex III. Its diffusion in the lipids is not rate-limiting for electron transfer, but its content is not saturating for maximal rate of NADH oxidation. Protein-bound coenzyme Q is involved in energy conservation, and may be part of enzyme supercomplexes, as in succinate cytochromec reductase. The reason for lack of kinetic saturation of the respiratory chain by quinone concentration is in the low extent of solubility of monomeric coenzyme Q in the membrane lipids. Assays of respiratory enzymes are performed using water soluble coenzyme Q homologs and analogs; several problems exist in using oxidized quinones as acceptors of coenzyme Q reductases. In particular, for complex I no acceptor appears to favorably substitute the endogenous quinone. In addition, quinone reduction sites in complex III compete with the sites in the dehydrogenases, particularly when using duroquinone. The different extent by which these sites operate when different donor substrates (NADH, succinate, glycerol-3-phosphate) are used is best explained by different exposure of the quinone acceptor sites in the dehydrogenases.     

Coenzyme Q-pool function in glycerol-3-phosphate oxidation in hamster brown adipose tissue mitochondria

We have investigated the role of the Coenzyme Q pool in glycerol-3-phosphate oxidation in hamster brown adipose tissue mitochondria. Antimycin A and myxothiazol inhibit glycerol-3-phosphate cytochromec oxidoreductase in a sigmoidal fashion, indicating that CoQ behaves as a homogeneous pool between glycerol-3-phosphate dehydrogenase and complex III. The inhibition of ubiquinol cytochromec reductase is linear at low concentrations of both inhibitors, indicating that sigmoidicity of antimycin A and myxothiazol inhibition is not a direct property of antimycin A and myxothiazol binding. Glycerol-3-phosphate cytochromec oxidoreductase is strongly stimulated by added CoQ₃, indicating that endogenous CoQ is not saturating. Application of the pool equation for nonsaturating ubiquinone allows calculation of theK _m for endogenous CoQ of glycerol-3-phosphate dehydrogenase of 3.14mM. The results of this investigations reveal that CoQ behaves as a homogeneous pool between glycerol-3-phosphate dehydrogenase and complex III in brown adipose tissue mitochondria; moreover, its concentration is far below saturation for maximal electron transfer activity in comparison with other branches of the respiratory chain connected with the CoQ pool. HPLC analysis revealed a lower amount of CoQ in brown adipose mitochondria (0.752 nmol/mg protein) in comparison with mitochondria from other tissues and the presence of both CoQ₉ and CoQ₁₀.     

Relationships among the rfb regions of Salmonella serovars A, B, and D.

The O antigens of Salmonella serogroups A, B, and D differ structurally in their side chain sugar residues. The genes encoding O-antigen biosynthesis are clustered in the rfb operon. The gene rfbJ in strain LT2 (serovar typhimurium, group B) and the genes rfbS and rfbE in strain Ty2 (serovar typhi, group D) account for the known differences in the rfb gene clusters used for determination of group specificity. In this paper, we report the nucleotide sequence of 2.9 kb of DNA from the rfb gene cluster of strain Ty2 and the finding of two open reading frames which have limited similarity with the corresponding open reading frames of strain LT2. These two genes complete the sequence of the rfb region of group D strain Ty2 if we use strain LT2 sequence where restriction site data show it to be extremely similar to the strain Ty2 sequence. The restriction map of the rfb gene cluster in group A strain IMVS1316 (serovar paratyphi) is identical to that of the cluster in strain Ty2 except for a frameshift mutation in rfbE and a triplicated region. The rfb gene clusters of these three strains are compared, and the evolutionary origin of these genes is discussed.     

A human beta-spectrin gene promoter directs high level expression in erythroid but not muscle or neural cells

beta-Spectrin is an erythrocyte membrane protein that is defective in many patients with abnormalities of red blood cell shape including hereditary spherocytosis and elliptocytosis. It is expressed not only in erythroid tissues but also in muscle and brain. We wished to determine the regulatory elements that determine the tissue-specific expression of the beta-spectrin gene. We mapped the 5'-end of the beta-spectrin erythroid cDNA and cloned the 5'-flanking genomic DNA containing the putative beta-spectrin gene promoter. Using transfection of promoter/reporter plasmids in human tissue culture cell lines, in vitro DNase I footprinting analyses, and gel mobility shift assays, a beta-spectrin gene erythroid promoter with two binding sites for GATA-1 and one site for CACCC-related proteins was identified. All three binding sites were required for full promoter activity; one of the GATA-1 motifs and the CACCC-binding motif were essential for activity. The beta-spectrin gene promoter was able to be transactivated in heterologous cells by forced expression of GATA-1. In transgenic mice, a reporter gene directed by the beta-spectrin promoter was expressed in erythroid tissues at all stages of development. Only weak expression of the reporter gene was detected in muscle and brain tissue, suggesting that additional regulatory elements are required for high level expression of the beta-spectrin gene in these tissues.     

Basigin-2 is a cell surface receptor for soluble basigin ligand

The metastatic spread of a tumor is dependent upon the ability of the tumor to stimulate surrounding stromal cells to express enzymes required for tissue remodeling. The immunoglobulin superfamily protein basigin (EMMPRIN/CD147) is a cell surface glycoprotein expressed by tumor cells that stimulates matrix metalloproteinase and vascular endothelial growth factor expression in stromal cells. The ability of basigin to stimulate expression of molecules involved in tissue remodeling and angiogenesis makes basigin a potential target for the development of strategies to block metastasis. However, the identity of the cell surface receptor for basigin remains controversial. The goal of this study was to determine the identity of the receptor for basigin. Using a novel recombinant basigin protein (rBSG) corresponding to the extracellular domain of basigin, it was demonstrated that the native, nonglycosylated rBSG protein forms dimers in solution. Furthermore, rBSG binds to the surface of uterine fibroblasts, activates the ERK1/2 signaling pathway, and induces expression of matrix metalloproteinases 1, 2, and 3. Proteins that interact with rBSG were isolated using a biotin label transfer technique and sequenced by matrix-assisted laser desorption ionization tandem mass spectrophotometry. The results demonstrate that rBSG interacts with basigin expressed on the surface of fibroblasts and is subsequently internalized. During internalization, rBSG associates with a novel form of human basigin (basigin-3). It was concluded that cell surface basigin functions as a membrane receptor for soluble basigin and this homophilic interaction is not dependent upon glycosylation of the basigin ligand.     

Rapid growth of planktonic Vibrio cholerae non-O1/non-O139 strains in a large alkaline lake in Austria: dependence on temperature and dissolved organic carbon quality

Vibrio cholerae non-O1/non-O139 strains have caused several cases of ear, wound, and blood infections, including one lethal case of septicemia in Austria, during recent years. All of these cases had a history of local recreational activities in the large eastern Austrian lake Neusiedler See. Thus, a monitoring program was started to investigate the prevalence of V. cholerae strains in the lake over several years. Genetic analyses of isolated strains revealed the presence of a variety of pathogenic genes, but in no case did we detect the cholera toxin gene or the toxin-coregulated pilus gene, both of which are prerequisites for the pathogen to be able to cause cholera. In addition, experiments were performed to elucidate the preferred ecological niche of this pathogen. As size filtration experiments indicated and laboratory microcosms showed, endemic V. cholerae could rapidly grow in a free-living state in natural lake water at growth rates similar to those of the bulk natural bacterial population. Temperature and the quality of dissolved organic carbon had a highly significant influence on V. cholerae growth. Specific growth rates, growth yield, and enzyme activity decreased markedly with increasing concentrations of high-molecular-weight substances, indicating that the humic substances originating from the extensive reed belt in the lake can inhibit V. cholerae growth.