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PubMedDate not supplied

Atrial natriuretic factor prohormone peptides are present in a variety of tissues.

Utilizing two sensitive and specific radioimmunoassays which immunologically recognize 1) the 98 amino acid (a.a.) N-terminus and 2) the 28 a.a. C-terminus (i.e., a.a. 99-126) of the 126 a.a. atrial natriuretic (ANF) prohormone, various tissues including aorta, kidney, small intestine, colon, liver, spleen, lung, and testis were investigated to determine if the ANF prohormone was present in any of these tissues in addition to its previously demonstrated presence in heart and brain. Aorta with 62.3 +/- 3 ng of the N-terminus/g of tissue and 51.6 +/- 1.8 ng of the C-terminus of the ANF prohormone/g of tissue had the highest concentration of the ANF prohormone of the previously undescribed ANF prohormone-containing tissues. The next highest concentration of the ANF prohormone was in the intestine, followed by lung and spleen. Pancreas, liver and kidney had similar levels of immunologically recognized ANF prohormone (approximately 1/50 of the aorta), while the testis and cerebrum had low levels. These results suggest that a much larger variety of tissues synthesize and/or store the ANF prohormone than is presently thought.

Animals↗
PubMed2003

Mutation in tcpR gene (Vc0832) of Vibrio cholerae O1 causes loss of tolerance to high osmolarity and affects colonization and virulence in infant mice.

Vibrio cholerae, the agent of cholera, multiplies and colonizes human intestinal tract where it survives high osmolarity due to bile and other sodium salts. In this work, by TnphoA mutagenesis, a mutant of V. cholerae O1 which could not grow and form colonies on LB agar containing 400 mM NaCl has been characterized. The mutant, designated CD83, adhered normally to freshly isolated rabbit intestinal discs, colonized poorly the gut of infant mice and was avirulent in the same model, whereas the parent strain CD81 would colonize the gut and cause death of mice. Attenuation of virulence of CD83 was not attributable to its inability to produce cholera toxin, as no difference was found in the cholera toxin produced in vitro by the mutant and parent strains. Molecular cloning and sequencing of the mutated gene revealed that insertion of transposon occurred in tcpR gene (Vc0832) of V. cholerae. Complementation of the mutant with wild-type tcpR gene resulted in restoration of the ability to survive at high salt concentration (400 mM NaCl), and to colonize the gut and restore virulence. The results suggest that tcpR plays a role in survival of V. cholerae in the small intestine of host as the osmolarity in the intestinal lumen is thought to be equivalent to 300 mM NaCl or higher.

Animals↗
PubMed2004

Pathogenic potential of environmental Klebsiella pneumoniae isolates.

Klebsiella pneumoniae is an important opportunistic pathogen and a frequent cause of nosocomial infections. K. pneumoniae infections can occur at nearly any body site; however, urinary tract infections and infections of the respiratory tract predominate. Infections are frequently preceded by gastrointestinal colonization, and the gastrointestinal tract is believed to be the most important reservoir for transmission of the bacteria. In contrast to many other bacterial pathogens, K. pneumoniae is ubiquitous in nature. Several studies have described Klebsiella isolates of environmental origin to be nearly identical to clinical isolates with respect to several phenotypic properties. However, the pathogenic potential of environmental K. pneumoniae isolates is essentially unknown. We have evaluated the virulence of K. pneumoniae strains of environmental and clinical origin directly in animal models, i.e. in urinary tract infection and intestinal colonization models. Furthermore, the ability to adhere to and invade human epithelial cell lines was examined. Although strain-to-strain differences were observed in the individual infection models, overall, strains of environmental origin were found to be as virulent as strains of clinical origin. The ubiquity of K. pneumoniae in nature and the general ability of K. pneumoniae strains to infect susceptible hosts might explain the high frequency of opportunistic infections caused by this species.

Adhesins, Bacterial↗
PubMed2004

The wheat variety used in the diet of laying hens influences colonization with the intestinal spirochaete Brachyspira intermedia.

This study investigated whether feeding different wheat varieties to laying hens could influence colonization with the intestinal spirochaete Brachyspira intermedia. Fifty ISA-Brown laying hens were divided into two groups. One group were fed a laying-hen diet formulated with wheat variety Westonia, and one were fed the diet incorporating variety Stilleto. Each group was divided into 15 hens experimentally infected with B. intermedia and 10 uninfected controls. The 30 infected hens were housed in individual cages in one room, and the controls were similarly housed in another room. Following administration of cultures of B. intermedia strain HB60 by crop-tube over 3 days, cloacal swabs were taken for spirochaete culture every 3 to 4 days. The water content of caecal faeces, and egg production and body weight were measured weekly. The hens were killed after 4 weeks, the caeca cultured for spirochaetes and the viscosity of the ileal contents measured. A total of 48/120 (40%) of the excreta samples from infected hens fed Westonia contained B. intermedia, compared with 21/120 (17.5%) for Stiletto (P = 0.0002). The ileal viscosity of hens fed Westonia also was higher (P = 0.048), but viscosity was not clearly related to the non-starch polysaccharide (NSP) content of the wheats. Westonia had a slightly higher total NSP content than Stiletto, but the ratio of soluble to insoluble NSP was lower. Infected hens developed wetter excreta, but neither infection nor diet altered egg production. In conclusion, the wheat variety can influence colonization with B. intermedia, apparently through diet-related alterations in the intestinal microenvironment.

Animal Feed↗
PubMed2002

Failure of Lactobacillus spp. to prevent bacterial translocation in a rat model of experimental cirrhosis.

BACKGROUND/AIMS: Prophylaxis of spontaneous bacterial peritonitis in cirrhotic patients with norfloxacin is associated with emergence of quinolone-resistant Enterobacteriaceae. We investigated whether an alternative strategy with Lactobacillus prevents bacterial translocation and ascitic fluid infection in cirrhotic rats. METHODS: CCl(4)-induced cirrhotic rats with ascites (n=34) were allocated to treatment with oral Lactobacillus strain GG at 1-2 x 10(9) cfu/day for 8-10 days (group LGG) or milk (group MILK). In addition, 20 cirrhotic rats were given a single dose of 15 mg norfloxacin orally and then allocated to Lactobacillus (group NOR-LGG) or milk (group NOR-MILK). Ten healthy rats served as control. After sacrifice the cecal flora were analyzed and the prevalence of bacterial translocation and ascitic fluid infection assessed. RESULTS: Cecal colonization with Lactobacillus was achieved in 90% of treated rats. The prevalence of bacterial translocation to mesenteric lymph nodes was 10% in control rats and 93, 84, 70 and 100% in groups MILK, LGG, NOR-MILK and NOR-LGG, respectively (P>0.1 for comparison of treatment groups), the prevalence of ascitic fluid infection was 60, 32, 40 and 40% (P>0.1). Bacterial translocation of Lactobacillus was observed in 24% of rats treated. CONCLUSION: Lactobacilli fail to prevent bacterial translocation and ascitic fluid infection in experimental cirrhosis in spite of successful intestinal colonization.

Animals↗
PubMed2005

Oral administration of two probiotic strains, Lactobacillus gasseri CECT5714 and Lactobacillus coryniformis CECT5711, enhances the intestinal function of healthy adults.

Modifications in gastrointestinal parameters, intestinal colonization and tolerance are some of the main goals claimed for probiotics. However, although healthy people are the common target for these new functional food products, the number of clinical trials analysing the effects of probiotics in gastrointestinal parameters of healthy subjects is very scarce. A randomized, double blind, placebo-controlled human clinical trial involving 30 healthy adults was performed to investigate the effect of a fermented product containing two probiotic strains, Lactobacillus gasseri CECT5714 and Lactobacillus coryniformis CECT5711, on several blood and fecal parameters, most of them related to the host intestinal function. The volunteers were randomly distributed into two groups, one receiving a standard yogurt and the other a similar dairy fermented product in which the Lactobacillus delbreuckii subsp. bulgaricus yogurt strain had been replaced by a combination of the probiotic strains L. gasseri CECT5714 and L. coryniformis CECT5711. The volunteers that received the probiotic strains reported no adverse effects and the strains could be isolated from their feces at a relatively high level. In fact, the concentration of fecal lactic acid bacteria significantly increased in the probiotic group. Additionally, the oral administration of the probiotic strains led to an improvement of parameters such as the production of short chain fatty acids, the fecal moisture and the frequency and volume of the stools. As a result, the volunteers assigned to the probiotic group perceived a clear improvement in their intestinal habits. The study revealed that probiotics may exert a positive effect on healthy adults.

Adult↗
PubMed1989

[The feeding of differently treated straw materials to piglets after various weaning times. 2. Fatty acids in the large intestine and parameters of protein, fat, carbohydrate and mineral metabolism in the blood serum during the feeding of untreated, HCl-treated and partly-hydrolysed straw meal].

In feeding experiments with piglets of the country species variously treated straw materials were used in concentrate--straw meal mixtures after the traditional weaning date (49th day of life) and studies were made of the fermentation of volatile fatty acids (VFA) in the large intestine (colon) and of the concentration of selected parameters of the protein, fat, carbohydrate and mineral metabolism in the blood serum of the animals. The concentrate--straw mixtures with a 10% straw quota contained untreated (II), HCl treated (HCl treatment without steaming, without (III) and with neutralization, IV) as well as partly hydrolysed straw meal (HCl treatment with subsequent steaming, without (V) and with neutralization with CaCO3, VI) were tested in comparison with sole feeding of concentrate (I) and its combination with wheat bran (VII). With regard to the fermentation processes in the large intestine in a comparison of the feeding groups (I-VII) the highest concentration and production quota of VFA was registered in I and the lowest in II. The straw treatment variants (III, IV, V and VI) took a medium position with regard to this and did not differ from each other. After their application of a significant increase in the molar acetate quota was ascertained in comparison with the sole feeding of concentrate (I), which was also characteristic of the other crude fibre sources (II and VII) and was reflected in the extension of the C2: C3 relation. Only few of the total of 15 selected parameters in the blood serum showed reactions of the intermediary metabolism of the test groups caused by feeding. The decrease of the urea concentration in the serum after the feeding of the treated straw materials (III, IV, V and VI) is particularly remarkable. In general, the urea concentration in the serum was negatively related to growth performance of the test groups. The use of HCl treated straw materials (III-VI) proved to be advantageous in comparison to the sole feeding of concentrate (I) and the use of other crude fibre sources (untreated straw meal (II) and wheat bran, VII) in the feeding regime of the keeping stage 'weaned pigs'.

Animal Feed↗
PubMedDate not supplied

Evolutionary origins of the mammalian apolipoproteinB RNA editing enzyme, apobec-1: structural homology inferred from analysis of a cloned chicken small intestinal cytidine deaminase.

Mammalian apolipoproteinB (apoB) RNA editing is a site-specific deamination reaction that mediates the C to U conversion responsible for apoB48 production in the mammalian small intestine. This process is not detected in chicken apoB RNA. Mammalian apoB RNA editing is mediated by a multicomponent enzyme complex that includes a single catalytic subunit, apobec-1. In order to examine the evolution of apobec-1, we have cloned and characterized an orthologous cytidine deaminase cDNA isolated from chicken small intestine. Northern blot analysis revealed expression restricted to the small intestine, colon and lung but not the liver or other tissues. The cDNA encodes a single 31 kDa protein with features reminiscent of other cytidine deaminases and with approximately 39% overall homology to rat apobec-1. The recombinant protein is a cytidine deaminase with activity on a monomeric substrate that was found to be zinc-dependent. However, no RNA editing activity was detectable towards cytidine nucleotides presented in the context of an optimally configured mammalian apoB RNA template. These studies provide information concerning the evolution of the apoB RNA editing machinery and indicate that a chicken small intestinal cytidine deaminase with homology to apobec-1 demonstrates no activity on an RNA substrate.

APOBEC-1 Deaminase↗
PubMed2002

Characterization of neuromedin U effects in canine smooth muscle.

Two endogenous receptors for the potent smooth muscle-stimulating peptide neuromedin U (NmU) have recently been identified and cloned. Pharmacological, binding, and expression studies were conducted in an attempt to determine the receptor(s) involved in the smooth muscle-stimulating effects of NmU. The NmU peptides caused a concentration-dependent contraction of canine isolated urinary bladder. NmU did not have this same effect in the urinary bladder from rat, guinea pig, rabbit, mouse, or ferret. Although NmU had no effect on canine uterus it did cause contraction of canine stomach, ileum, and colon. As well as causing contraction of canine bladder in vitro, NmU administered systemically resulted in a significant increase in urinary bladder pressure in vivo. High-affinity binding sites for NmU were identified in canine bladder. The four NmU peptides porcine NmU-8, rat NmU-23, human NmU-25, and porcine NmU-25 displaced (125)I-NmU-25 binding with similar K(i) values (0.08-0.24 nM). A different binding profile was revealed in human embryonic kidney-293 cells transiently expressed with the canine NmU-2 receptor where porcine NmU-8 (K(i) = 147.06 nM) was much less potent than the other NmU peptides. Using TaqMan, expression of NmU-1 was detected in human urinary bladder, small intestine, colon, and uterus. Expression of NmU-2 was much lower or absent in these human tissues and undetectable in canine bladder and stomach. The results of this study reveal significant species differences in the activity of NmU. The contractile activity in human and canine smooth muscle seems to be mediated by the recently cloned NmU-1 receptor.

Animals↗
PubMed2005

Oxalate degrading bacteria: new treatment option for patients with primary and secondary hyperoxaluria?

Current treatment options in patients with primary and secondary hyperoxaluria are limited and do not always lead to sufficient reduction in urinary oxalate excretion. Intestinal oxalate degrading bacteria are capable of degrading oxalate to CO(2) and formate, the latter being further metabolized and excreted via the feces. It is speculated, that both endogenously produced, as well as dietary oxalate can be significantly removed via the intestinal tract. Oxalobacter formigenes, an obligate anaerobic microbe normally found in the intestinal tract has one oxalate degrading enzyme, oxalyl-CoA decarboxylase, which is also found in Bifidobacterium lactis. Other bacteria with possible oxalate degrading potency are lactic acid bacteria, as well as Enterococcus faecalis and Eubacterium lentum. However, specific therapeutic studies on humans are scarce and, except for Oxalobacter, data are not congruent. We found the oral application of Oxalobacter successful in patients with primary hyperoxaluria. However, long-term post-treatment follow-up of 1-2 years showed that constant intestinal colonization is not achieved in most patients. In one patient with constant colonization, urinary oxalate excretion normalized over time. Short-term studies with other bacteria such as lactic acid bacteria did not show a specific reduction in urinary oxalate excretion. O. formigenes might be a promising new therapeutic tool in patients with primary and secondary hyperoxaluria.

Bacteria↗
PubMed1998

Fractional absorption of L-carnitine after oral administration in rats: evaluation of absorption site and dose dependency.

We evaluated the fractional absorption of L-carnitine, a gamma-amino acid essential cofactor for the transfer of long-chain fatty acids, in rats in vivo after oral administration to determine its absorption behavior. At both low (0.05 micromol/rat) and high (100 micromol/rat) doses, L-carnitine was recovered only from the region of the cecum and below at 10 h after administration. During a major shift in distribution from cecum at 10 h to feces at 24 h, there was no significant change in the total recovery at each dose, suggesting that L-carnitine absorption is negligible in the cecum and the large intestine (colon and rectum). However, the recovery of L-carnitine was incomplete and the fraction recovered was larger at the high dose than at the low dose. The fractions absorbed were estimated to be 96.7 and 33.0% for the low and high doses, respectively, as these were the fractions that disappeared from the gastrointestinal tract. These values were comparable with 100 and 42%, respectively, of bioavailability values by the pharmacokinetic analysis of plasma concentration data in our preceding study [Matsuda et al., Biopharmaceutics & Drug Disposition, in press]. These results suggest that L-carnitine is significantly absorbed only in the small intestine, without undergoing first-pass degradation, and in a dose-dependent manner presumably due to the involvement of saturable transport by L-carnitine carriers. Consistent with the suggestions in vivo, L-carnitine absorption in the closed intestinal loop in situ was concentration-dependent in the small intestine but not in the large intestine, and the apparent membrane permeability in the large intestine was smaller by an order of magnitude than that of passive transport in the small intestine. These findings support our preceding kinetic modeling strategy assuming the small intestine to be the sole absorption site, and should be of help in guiding studies on development of more efficient oral L-carnitine delivery strategies.

Administration, Oral↗
PubMed2003

Altered morphology in cultured rat intestinal epithelial IEC-6 cells is associated with alkaline phosphatase expression.

Non-transformed, rat intestinal epithelial cells (IEC-6), and human intestinal colonic carcinoma cells (CACO-2) have both been used to study processes of epithelial cell differentiation. However, only CACO-2 cells have been described as spontaneously expressing phenotypic changes of differentiation in culture. We report here that when IEC-6 cells are grown in post-confluent culture, they develop structural changes similar to those seen in cells induced to differentiate by culture on Englebreth-Holm-Swarm (EHS) extracellular matrix proteins. Correlated with this morphological change is loss of nuclear localization of c-myc protein and development of cell surface alkaline phosphatase (ALP) enzymatic activity. Messenger RNAs for liver and intestinal isoforms of ALP were expressed in both pre- and post-confluent cells. Inhibition of ALP activity in post-confluent cells by levamisole indicated the expressed ALP activity to be of the liver isoform. We suggest the expression of ALP activity, which occurs concomitantly with morphological alterations in post-confluent IEC-6 cells, represents increased expression and localization to the cell surface of the liver isoform of ALP. Cultured IEC-6 cells may provide a non-transformed, in vitro alternative to CACO-2 cells for study of epithelial cell differentiation.

Alkaline Phosphatase↗
PubMed2006

Postchill campylobacter prevalence on broiler carcasses in relation to slaughter group colonization level and chilling system.

Data from an ongoing national surveillance program of Campylobacter prevalence in broiler slaughter groups were related to results from a 1-year baseline study of broiler carcasses postchill. The goals were to establish the relation between Campylobacter prevalence in slaughter groups and on carcasses and to determine the effect of various chilling systems on Campylobacter prevalence. Pooled cloacal and neck skin samples from the surveillance program were analyzed after enrichment. Carcass rinse samples from the baseline study were analyzed after enrichment and by direct plating. Data from both studies were available for 614 carcasses. Direct-plating analyses indicated that the percentages of carcasses positive for Campylobacter jejuni and other Campylobacter spp. in slaughter groups with negative cloacal samples were 2 and 10%, respectively, whereas enrichment analyses indicated prevalences of 2% in both cases. Campylobacter prevalence in slaughter groups with a high degree of intestinal colonization (more than half of the pooled cloacal samples positive) was significantly higher than in slaughter groups with a low degree of colonization (76 to 85% and 30 to 50%, respectively, depending on Campylobacter spp. and analytical method). The prevalence of Campylobacter-positive carcasses postchill was at the same level as the prevalence of carcasses that originated from slaughter groups with positive neck skin samples at four of the six slaughterhouses. Only at one slaughterhouse, with an air-chilling system, was the postchill prevalence (13%) lower than that expected from slaughter group data (23%). The postchill prevalence (43%) was higher than that expected from slaughter group data (33%) at one slaughterhouse with immersion chilling.

Abattoirs↗
PubMed1999

Vibrio cholerae intestinal population dynamics in the suckling mouse model of infection.

The suckling mouse has been used as a model to identify Vibrio cholerae intestinal colonization factors for over two decades, yet little is known about the location of recoverable organisms along the gastrointestinal (GI) tract following intragastric inoculation. In the present study, we determined the population dynamics of wild-type and avirulent mutant derivatives of both classical and El Tor biotype strains throughout the entire suckling mouse GI tract at various times after intragastric inoculation. Wild-type strains preferentially colonized the middle small bowel with a sharp demarcation between more proximal segments which had manyfold-fewer recoverable cells. Surprisingly, large and stable populations of viable cells were also recovered from the cecum and large bowel. Strains lacking toxin-coregulated pili (TCP(-)) were cleared from the small bowel; however, an El Tor TCP(-) strain colonized the cecum and large bowel almost as well as the wild-type strain. Strains lacking lipopolysaccharide O antigen (OA(-)) were efficiently cleared from the small bowel at early times but then showed net growth for the remainder of the infections. Moreover, large populations of the OA(-) strains were maintained in the large bowel. These results show that for the El Tor biotype neither TCP nor OA is required for colonization of the suckling mouse large bowel. Finally, similar percent recoveries of wild-type, TCP(-), and OA(-) strains from the small bowel at an early time after infection suggest that TCP and OA are not required for strains of either biotype to resist bactericidal mechanisms in the suckling mouse GI tract.

Animals↗
PubMed2006

The fibronectin binding protein ShdA is not a prerequisite for long term faecal shedding of Salmonella typhimurium in pigs.

Porcine carcasses contaminated with Salmonella typhimurium pose significant public health problems. Prolonged faecal shedding of Salmonella in pigs contributes to the contamination level of carcasses. Although the mechanism of prolonged faecal shedding is not yet clarified, the CS54 Island, and more specifically the shdA gene encoding a fibronectin binding autotransporter protein, was identified as an important locus for intestinal colonization and persistence of Salmonella typhimurium in mice. The aim of this study was to assess the contribution of ShdA in faecal shedding of Salmonella typhimurium in pigs. Pigs were orally inoculated with a Salmonella typhimurium wild type field strain or its isogenic shdA mutant strain. For the first few days after inoculation, the shdA mutant strain was excreted more, the diarrhoea was more pronounced and higher numbers of internal organs were infected. No effect on long-term shedding was found. In a porcine ileal loop model, the wild type strain and shdA mutant strain did not show any differences in the induction of neutrophil influx into the intestinal wall and lumen. In conclusion, we have shown that a Salmonella typhimurium deletion mutant in shdA is more virulent during the first days after inoculation and is not significantly impaired in persistence or prolonged shedding in pigs.

Animals↗
PubMed1990

Molecular cloning of cDNAs derived from a novel human intestinal mucin gene.

A human small intestinal lambda gt11 cDNA library was screened with antibodies to deglycosylated small intestinal mucin. Four partial cDNA clones were isolated that define a novel human mucin gene. These include two partial cDNA clones, SIB 124 and SIB 139, that contain 51 nucleotide tandem repeats which encode a seventeen amino acid repetitive peptide with a consensus sequence of HSTPSFTSSITTTETTS. SIB 139 hybridized to messages produced by small intestine, colon, colonic tumors and also by high mucin variant LS174T colon cancer cells. The gene from which cDNAs SIB 124 and SIB 139 are derived (proposed name MUC 3) maps to chromosome 7, distinct from other known human mucin genes.

Amino Acid Sequence↗
PubMed1983

Critical review of epidemiologic studies related to ingested asbestos.

Thirteen epidemiologic studies of ingested asbestos conducted in five areas of the United States and Canada were reviewed and evaluated for the definitiveness and applicability regarding the development of ambient water quality standards. One or more studies found male or female associations between asbestos in water supplies and cancer mortality (or incidence) due to neoplasms of the esophagus, stomach, small intestine, colon, rectum, gallbladder, pancreas, peritoneum, lungs, pleura, prostate, kidneys, brain, and thyroid, and also due to leukemia. Several methodologic weaknesses and limitations were found in each study, leading to the determination that no individual study or aggregation of studies exist that would establish risk levels from ingested asbestos. A binomial probability analysis of the eight independent studies suggested that, while the level of male-female agreement was generally low, the number of observed positive associations in males and females for neoplasms of the esophagus, stomach, pancreas, and prostate was unlikely to have been generated by chance factors alone, and thus, may have a biological basis related to ingested asbestos. Cancers of the small intestine and leukemia were implicated to a lesser degree in this analysis. The patterns of integrated findings for most gastrointestinal cancers were somewhat consistent with patterns observed among asbestos-exposed occupational groups, whereas the patterns found for pancreatic cancer, kidney cancer, and leukemia were not consistent.(ABSTRACT TRUNCATED AT 250 WORDS)

Asbestos↗