Complete degradation of carbohydrate to carbon dioxide and methane by syntrophic cultures of Acetobacterium woodii and Methanosarcina barkeri

Methanosarcina barkeri (strain MS) grew and converted acetate to CO₂ and methane after an adaption period of 20 days. Growth and metabolism were rapid with gas production being comparable to that of cells grown on H₂ and CO₂. After an intermediary growth cycle under a H₂ and CO₂ atmosphere acetateadapted cells were capable of growth on acetate with formation of methane and CO₂. When acetate-adapted Methanosarcina barkeri was co-cultered with Acetobacterium woodii on fructose or glucose as substrate, a complete conversion of the carbohydrate to gases (CO₂ and CH₄) was observed.Abbreviation CMC carboxymethyl cellulose     

A cluster of basic amino acid residues in the gamma370-381 sequence of fibrinogen comprises a binding site for platelet integrin alpha(IIb)beta3 (glycoprotein IIb/IIIa)

Adhesive interactions of platelet integrin alpha(IIb)beta3 with fibrinogen and fibrin are central events in hemostasis and thrombosis. However, the mechanisms by which alpha(IIb)beta3 binds these ligands remain incompletely understood. We have recently demonstrated that alpha(IIb)beta3 binds the gamma365-383 sequence in the gammaC-domain of fibrin(ogen). This sequence contains neither the AGDV nor the RGD recognition motifs, known to bind alpha(IIb)beta3, suggesting the different specificity of the integrin. Here, using peptide arrays, mutant fibrinogens, and recombinant mutant gammaC-domains, we have examined the mechanism whereby alpha(IIb)beta3 binds gamma365-383. The alpha(IIb)beta3-binding activity was localized within gamma370-381, with two short sequences, gamma370ATWKTR375 and gamma376WYSMKK381, being able to independently bind the integrin. Furthermore, recognition of alpha(IIb)beta3 by gamma370-381 depended on four basic residues, Lys373, Arg375, Lys380, and Lys381. Simultaneous replacement of these amino acids and deletion of the gamma408AGDV411 sequence in the recombinant gammaC-domain resulted in the loss of alpha(IIb)beta3-mediated platelet adhesion. Confirming the critical roles of the identified residues, abnormal fibrinogen Kaiserslautern, in which gammaLys380 is replaced by Asn, demonstrated delayed clot retraction and impaired alpha(IIb)beta3 binding. Also, a mutant recombinant fibrinogen modeled after the naturally occurring variant Osaka V (gammaArg375 --> Gly) showed delayed clot retraction and reduced binding to purified alpha(IIb)beta3. These results identify the gamma370-381 sequence of fibrin(ogen) as the binding site for alpha(IIb)beta3 involved in platelet adhesion and clot retraction and define the new recognition specificity of this integrin.     

Contamination of equipment in emergency settings: An exploratory study with a targeted automated intervention

Introduction

Gastro-oesophageal reflux disease (GORD) is a common problem in the Western countries, and the interest in the minimal access surgical approaches to treat GORD is increasing. In this study, we would like to discuss the presentations and management of complications we encountered after Laparoscopic Nissen's fundoplication in our District General NHS Hospital. The aim is to recognise these complications at the earliest stage for effective management to minimise the morbidity and mortality.

Methods

301 patients underwent laparoscopic treatment for GORD by a single consultant surgeon in our NHS Trust from September 1999. The data was prospectively collected and entered into a database. The data was retrospectively analysed for presentations for complications and their management.

Results

Surgery was completed laparoscopically in all patients, except in five, where the operation was technically difficult due to pre-existing conditions. The complications we encountered during surgery and follow-up period were major intra-operative bleeding (n = 1, 0.33%), severe post-operative nausea and vomiting (n = 1, 0.33%), wound infection (n = 3, 1%), port-site herniation (n = 1, 0.33%), wrap-migration (n = 2, 0.66%), wrap-ischaemia (n = 1, 0.33%), recurrent regurgitation (n = 4, 1.32%), recurrent heartburn (n = 29, 9.63%), tension pneumothorax (n = 2, 0.66%), surgical emphysema (n = 8, 2.66%), and port-site pain (n = 4, 1.33%).

Conclusion

Minimal access approach to treat GORD has presented with some specific and unique complications. It is important to recognise these complications at the earliest possible stage as some of these patients may present in an acute setting requiring emergency surgery. All members of the department, and not just the members of the specialised team, should be aware about these complications to minimise the morbidity and mortality.     

A New Group of Hepadnaviruses Naturally Infecting Orangutans (Pongo pygmaeus)

A high prevalence (42.6%) of hepatitis B virus (HBV) infection was suspected in 195 formerly captive orangutans due to a large number of serum samples which cross-reacted with human HBV antigens. It was assumed that such viral infections were contracted from humans during captivity. However, two wild orangutans were identified which were HBV surface antigen positive, indicating that HBV or related viruses may be occurring naturally in the orangutan populations. Sequence analyses of seven isolates revealed that orangutans were infected with hepadnaviruses but that these were clearly divergent from the six known human HBV genotypes and those of other nonhuman hepadnaviruses reported. Phylogenetic analyses revealed geographic clustering with Southeast Asian genotype C viruses and gibbon ape HBV. This implies a common origin of infection within this geographic region, with cross-species transmission of hepadnaviruses among hominoids.     

Sequencing of multiple clostridial genomes related to biomass conversion and biofuel production

Modern methods to develop microbe-based biomass conversion processes require a system-level understanding of the microbes involved. Clostridium species have long been recognized as ideal candidates for processes involving biomass conversion and production of various biofuels and other industrial products. To expand the knowledge base for clostridial species relevant to current biofuel production efforts, we have sequenced the genomes of 20 species spanning multiple genera. The majority of species sequenced fall within the class III cellulosome-encoding Clostridium and the class V saccharolytic Thermoanaerobacteraceae. Species were chosen based on representation in the experimental literature as model organisms, ability to degrade cellulosic biomass either by free enzymes or by cellulosomes, ability to rapidly ferment hexose and pentose sugars to ethanol, and ability to ferment synthesis gas to ethanol. The sequenced strains significantly increase the number of noncommensal/nonpathogenic clostridial species and provide a key foundation for future studies of biomass conversion, cellulosome composition, and clostridial systems biology.     

Diatomaceous earth increases the efficacy of Beauveria bassiana against Tribolium castaneum larvae and increases conidia attachment

This research tested the suppressive ability of Beauveria bassiana (Balsamo) Vuillemin alone and in combination with diatomaceous earth against the red flour beetle, Tribolium castaneum (Herbst). Adults did not show a dose response to B. bassiana, and the addition of diatomaceous earth (DE) did not result in a significant increase in mortality. Against larvae, however, DE at 190 mg/kg grain enhanced the efficacy of B. bassiana at all concentrations ranging from 33 to 2,700 mg of conidia per kilogram of grain. The presence of DE resulted in 17- and 16-fold decreases in the median lethal concentration of B. bassiana at 56 and 75% RH, respectively. No significant differences in larval mortality in response to B. bassiana and diatomaceous earth alone or in combination were found between 56 and 75% RH. Conidial attachment to larvae was significantly greater with 190 mg/kg DE than without it. The partial analysis of lipids taken up by DE from the larvae revealed the removal of phospholipids and long-chain fatty acids. These results support the hypothesis that diatomaceous earth enhances the efficacy of B. bassiana against larval T. castaneum, at least in part by damaging the insect cuticle, thus increasing conidial attachment and making nutrients more available to conidia for their germination.     

Enzymatic mechanisms for catalysis of enolization: ketosteroid isomerase

Breaking a carbon-hydrogen bond adjacent to a carbonyl is a slow step in a large number of chemical reactions. However, many enzymes are capable of catalyzing this reaction with great efficiency. One of the most proficient of these enzymes is 3-oxo-Delta5-steroid isomerase (KSI), which catalyzes the isomerization of a wide variety of 3-oxo-Delta5-steroids to their Delta4-conjugated isomers. In this review, the mechanism of KSI is discussed, with particular emphasis on energetic considerations. Both experimental and theoretical approaches are considered to explain the mechanistic details of the reaction.     

A novel dysmorphic syndrome with open calvarial sutures and sutural cataracts maps to chromosome 14q13-q21

We describe a new dysmorphic syndrome in an inbred Saudi Arabian family with 21 members. Five males and one female have similar craniofacial features including wide open calvarial sutures with large and late-closing anterior fontanels, frontal bossing, hyperpigmentation with capillary hemangioma of the forehead, significant hypertelorism, and a broad and prominent nose. In addition, these individuals have Y-shaped sutural cataracts diagnosed by 1-2 years of age. No chromosomal or biochemical abnormalities were identified. A genome-wide scan was performed, and two-point LOD score analysis, assuming autosomal recessive inheritance, detected linkage to chromosome 14q13-q21. The highest LOD scores were obtained for marker GATA136A04 (LOD=4.58 at theta=0.00) and for the adjacent telomeric marker D14S1048 (LOD=4.32 at theta=0.00). Multipoint linkage analysis resulted in a maximum LOD score of 5.44 between markers D14S1048 and GATA136A04. Model independent analysis by SIBPAL confirmed linkage to the same chromosomal region. Haplotype analysis indicated that all affected individuals were homozygous for the interval on chromosome 14q13-q21 with two recombinants for D14S1014 (centromeric) and one recombinant for D14S301 (telomeric). These recombinations limit the disease locus to a region of approximately 7.26 Mb. Candidate genes localized to this region were identified, and analysis of PAX9 did not identify mutations in these patients. The unique clinical phenotype and the mapping data suggest that this family represents a novel autosomal recessive syndrome.     

Pertussis toxin-sensitive G-proteins inhibit fibroblast growth factor-induced signaling in pancreatic acini

Signal transduction of fibroblast growth factor (FGF) receptors is known to involve tyrosine phosphorylation of several substrates, including Grb2, phospholipase C-γ, and phosphatidylinositol 3-kinase, whereas the role of G-proteins in FGF receptor signaling is controversial. In the present study we investigated the role of G-proteins in FGF receptor signaling in rat pancreatic acini. Immunological analysis revealed the presence of FGF receptor and phospholipase C-γ1 in rat pancreatic acini. Both basic fibroblast growth factor (FGF-2) and guanosine 5′-(γ-O-thio)triphosphate (GTPγS) caused an increase in inositol 1,4,5-trisphosphate (1,4,5-IP₃) production and amylase release. Combined stimulation of the acini with GTPγS and FGF-2 led to a decrease of these responses as compared to the effect of the single substances. When pancreatic acini were preincubated with FGF-2 (1 nM) or vehicle (water) ADP-ribosylation of the α-subunit of G_i-type G-proteins by pertussis toxin was reduced in membranes prepared from FGF-2 pretreated acini as compared to control acini, suggesting functional interaction of FGF receptors with G_i-proteins. Pretreatment of acini with pertussis toxin which inhibits G_i-type G-proteins abolished the inhibitory effect of GTPγS on FGF-induced 1,4,5-IP₃ production and amylase release, whereas the stimulatory effects of FGF-2 and GTPγS on these parameters remained unchanged. In conclusion, these results show communication of FGF receptors and G_i-type G-proteins and that G_i-type G-proteins exert an inhibitory influence on FGF-induced activation of phosphoinositide-specific phospholipase C in pancreatic acinar cells. © 1996 Wiley-Liss, Inc.