Nutrient niche specificity for glycosaminoglycans is reflected in polysaccharide utilization locus architecture of gut species.

Introduction: Glycosaminoglycans (GAGs) present in the mucosal layer can be used as nutrients by certain intestinal bacteria, particularly members of the Bacteroides. GAG abundances are altered in some diseases such as inflammatory bowel diseases, which may affect microbial composition and activity, and it is therefore important to understand GAG utilization by members of the gut microbiota.

Methods: We used growth assays, transcriptomics, and comparative genomics to evaluate chondroitin sulfate (CS) and hyaluronan (HA) degradation ability by multiple gut Bacteroides species.

Impaired Mucosal Homeostasis in Short-Term Fiber Deprivation Is Due to Reduced Mucus Production Rather Than Overgrowth of Mucus-Degrading Bacteria.

The gut mucosal environment is key in host health; protecting against pathogens and providing a niche for beneficial bacteria, thereby facilitating a mutualistic balance between host and microbiome. Lack of dietary fiber results in erosion of the mucosal layer, suggested to be a result of increased mucus-degrading gut bacteria. This study aimed to use quantitative analyses to investigate the diet-induced imbalance of mucosal homeostasis.

Early complications after stoma formation: a prospective cohort study in 100 patients with 1-year follow-up.

Purpose: This study aims to provide an overview of all complications that may occur after construction of an ileostomy or colostomy (loop or end) in daily practice.

Methods: Between July 2007 and April 2008, all adult patients who underwent any type of intestinal stoma formation were asked to participate in this prospective cohort study. All relevant patient characteristics were gathered.

[A man with chronic abdominal pain and obstipation].

A 66-year old man presents with chronic pain in the abdomen and obstipation. Explorative laparotomy revealed that his symptoms were caused by a giant diverticle from the colon sigmoideum.

Fecal incontinence: an update on available techniques in diagnosis and treatment.

Fecal incontinence remains a major problem with significant social and medical implications. Its causes are diverse and not always apparent. Therefore, diagnostic workup is essential to find the underlying cause and initiate adequate treatment.

Transanal endoscopic operation for rectal lesions using two-dimensional visualization and standard endoscopic instruments: a prospective cohort study and comparison with the literature.

Background: The transanal endoscopic operation (TEO) has proved to be an effective alternative to conventional surgery for the treatment of rectal lesions. The TEO procedure offers reduced morbidity, faster recovery and equivalent oncologic outcome. Currently, two instrument sets are available: one with three-dimensional (Wolf) and one with two-dimensional (Storz) optic capacities.

Breast MRI in nonpalpable breast lesions: a randomized trial with diagnostic and therapeutic outcome - MONET - study.

Background: In recent years there has been an increasing interest in MRI as a non-invasive diagnostic modality for the work-up of suspicious breast lesions. The additional value of Breast MRI lies mainly in its capacity to detect multicentric and multifocal disease, to detect invasive components in ductal carcinoma in situ lesions and to depict the tumor in a 3-dimensional image. Breast MRI therefore has the potential to improve the diagnosis and provide better preoperative staging and possibly surgical care in patients with breast cancer.

The localization of labelled fish prolactin in various tissues of rainbow trout (Salmo gairdneri).

Rostral lobes of the pars distalis from rainbow trout, Salmo gairdneri, were incubated in vitro in a medium containing 14C-labelled lysine. The labelled proteins in these lobes and medium were separated by polyacrylamide gel electrophoresis, the prolactin eluted from the appropriate band, and injected into intact trout. Following the injections, various tissues were dissected out and observed autoradiographically.

Regulation of melanotropin release from the pars intermedia of the amphibian Xenopus laevis: evaluation of the involvement of serotonergic, cholinergic, or adrenergic receptor mechanisms.

Melanophore-stimulating hormone (MSH) release from the pars intermedia of the pituitary gland is probably regulated by multiple factors of hypothalamic origin. We have examined a number of potential regulatory factors for their effects on MSH release from the amphibian Xenopus laevis. Serotonin and acetylcholine have no effect on MSH release.

The pituitary adrenocorticotropes originate from neural ridge tissue in Xenopus laevis.

A series of grafting experiments was conducted to determine pituitary origins prior to brain tube closure in Xenopus laevis. Extirpation experiments indicated that the ventral neural ridge (VNR) tissue of stage-18+ embryos was essential for pituitary development. Bolton-Hunter reagent was used to label stage-18+ VNR tissue with 125I, and this tissue was then returned to the donor and its subsequent ontogenesis followed.

Acetylation of melanocyte-stimulating hormone and beta-endorphin in the pars intermedia of the perinatal pituitary gland in the mouse.

This report concerns ontogenetic aspects of the production and in vitro release of NH2-terminally acetylated forms of melanocyte-stimulating hormone (alpha-MSH) and beta-endorphin by the pars intermedia of the pituitary gland of the mouse. In vitro biosynthetic analysis and radioimmunoassay revealed that approximately 12 h before birth most of the MSH in the fetal pars intermedia is present as des-N alpha-acetyl alpha-MSH. The same non-acetylated peptide is at this stage also the major release form of melanotropin.

The functional significance of glycosylation of pro-opiomelanocortin in melanotrophs of the mouse pituitary gland.

Pro-opiomelanocortin (POMC) is a glycoprotein precursor for a number of neuropeptides and peptide hormones. The functional significance of the glycosylation of POMC has never been established. Using the antibiotic tunicamycin to block glycosylation of the prohormone in the mouse pars intermedia, we have compared processing of non-glycosylated prohormone with that of glycosylated prohormone in pulse-chase experiments.

Biosynthesis, processing and release of pro-opiomelanocortin related peptides in the intermediate lobe of the pituitary gland of the frog (Rana ridibunda).

The biosynthesis of pro-opiomelanocortin (POMC) and related peptides by the intermediate lobe of the pituitary gland was studied in the frog Rana ridibunda using the pulse-chase technique. Analysis of radioactive proteins by dodecyl sulfate polyacrylamide gel electrophoresis showed that during pulse incubations a 36,000 dalton (36K) glycosylated prohormone was synthesized. It disappeared slowly during chase incubations, giving rise to another glycosylated protein (Mr 18K), identified as the N-terminal fragment of POMC.

The development of the pars intermedia and its role in the regulation of dermal melanophores in the larvae of the amphibian Xenopus laevis.

The ontogenesis of biosynthesis of pro-opiomelanocortin (POMC)-related peptides in the pars intermedia of Xenopus laevis tadpoles was studied. The results were related to the capacity of the animal to adapt to background color through regulation of pigment dispersion in dermal melanophores. Using immunocytochemical techniques with antisera to alpha-melanophore-stimulating hormone (alpha-MSH), it was revealed that this peptide first appeared at developmental stage 37/38, just prior to the animal's ability to adapt to background.

Biosynthesis of pro-opiomelanocortin-derived peptides in the mouse neurointermediate lobe.

This report concerns biosynthetic studies conducted with neurointermediate lobes of the mouse pituitary gland. High performance liquid chromatography was used to resolve newly synthesized peptides after in-vitro incubation of lobes with radioactive amino acids. Among the newly synthesized peptides identified were alpha-MSH, des-N alpha-acetyl-alpha-MSH, two forms of corticotrophin-like intermediate lobe peptide and beta-endorphin.

The frog pars intermedia contains only the non-acetylated form of alpha-MSH: acetylation to generate alpha-MSH occurs during the release process.

Pulse-chase experiments revealed that the frog pars intermedia synthesizes the desacetyl form of alpha-MSH. Its structure was shown to be similar, if not identical, to the mammalian structure. During release two additional peptides derived from desacetyl alpha-MSH appeared, one being alpha-MSH.

In vivo biosynthesis of melanotropins and related peptides in the pars intermedia of Xenopus laevis.

To study in vivo biosynthesis of pars intermedia peptides in Xenopus laevis, [3H]lysine was administered by an osmotic minipump via a cannula inserted near the pituitary gland. Following extraction of the neurointermediate lobe, high-performance liquid chromatography was used to separate the newly synthesized peptides. In black-background adapted animals, [3H]lysine was incorporated into a number of peptides.

Biosynthesis of a gamma 3-melanotropin-like peptide in the pars intermedia of the amphibian pituitary gland.

This study reveals the biosynthesis of a gamma 3-melanotropin-like peptide in the pars intermedia of the pituitary gland of the aquatic toad Xenopus laevis. Pulse-chase experiments in vitro showed that this product is synthesized through processing of a prohormone, pro-opiomelanocortin, and that it is released into the incubation medium. The peptide immunoprecipitated with antiserum to gamma 3-melanotropin, appeared to be a glycopeptide and displayed melanotropic activity.

Biosynthesis of two structurally different pro-opiomelanocortins in the pars intermedia of the amphibian pituitary gland.

This study reports the biosynthesis of two forms of pro-opiomelanocortin in the pars intermedia of the pituitary gland of the African clawed toad Xenopus laevis. The two forms could be resolved by dodecyl sulphate gel electrophoresis on a 9-16% acrylamide gradient and their molecular weights were 38200 and 37300. Incubation of neurointermediate lobes with [3H]glucosamine followed by tryptic digestion of the newly synthesized glycoproteins, revealed that both prohormones have only one glycosylated site, namely within the region corresponding to gamma 3-melanotropin.

Biosynthesis of pairs of peptides related to melanotropin, corticotropin and endorphin in the pars intermedia of the amphibian pituitary gland.

This study concerns the biosynthesis of a number of peptides in the neurointermediate lobe of the pituitary gland of the aquatic toad, Xenopus laevis. Using pulse-chase incubations in vitro and high-performance liquid chromatographic analysis, it could be shown that these peptides are synthesized through processing of a prohormone, pro-opiomelanocortin; all peptides were released into the incubation medium. On the basis of electrophoretic analysis, selective amino acid incorporation and immunoprecipitation, as well as peptide mapping by high-performance liquid chromatography, the peptides were classified into three distinct groups: two related to melanocyte-stimulating hormone (melanotropin), two related to adrenocorticotropic hormone (corticotropin) and two endorphin-like peptides.