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At least 991 records · Page 55Linked to original sources
PubMed1994

Pregnenolone and dehydroepiandrosterone as precursors of native 7-hydroxylated metabolites which increase the immune response in mice.

Dehydroepiandrosterone (DHEA) and pregnenolone (PREG) were both metabolized by homogenates of brain, spleen, thymus, perianal skin, ventral skin, intestine, colon, coecum and muscle tissues from mice. The use of 2H-labeled substrates and of the twin ion technique of gas chromatography-mass spectrometry permitted identification of 7 alpha-hydroxy-DHEA and of 5-androstene-3 beta, 17 beta-diol as DHEA metabolites in digests of all tissues. The extent of PREG metabolism was much lower than for DHEA with all tissues but amounts of the main transformation product were sufficient in brain, spleen and ventral skin digests for identification with 7 alpha-hydroxy-PREG. Dimethylsulfoxide (DMSO) solutions of DHEA, PREG and of their 7-hydroxylated metabolites were injected at different doses and time intervals prior to proximal subcutaneous administration of a lysozyme antigen. Quantities of anti-lysozyme IgG were measured in the serum of treated mice and compared with that from sham-treated animals. Increase of anti-lysozyme IgG was obtained with DHEA and PREG (1 g/kg) when injected 2 h prior to lysozyme. Much lower doses (160 times less) of 7 alpha-hydroxy-DHEA and -PREG were also found to be significantly active when administered at the moment of lysozyme injection. A larger dose of 7 beta-hydroxy-DHEA (50 mg/kg) was necessary for a similar effect. These results suggest that in tissues where immune response takes place, the locally-produced 7-hydroxy metabolites of PREG and DHEA are involved in a process which may participate in the physiological regulation of the body's immune response.

Androstenediol↗
PubMed2006

Expression of chemokines in GVHD target organs is influenced by conditioning and genetic factors and amplified by GVHR.

Graft-versus-host disease (GVHD) is the most significant clinical problem that arises after allogeneic hematopoietic cell transplantation. Because chemokines induced by proinflammatory conditioning treatment may promote T-cell migration into GVHD target tissues, we addressed the influence of conditioning on chemokine expression in GVHD target organs. Our results showed that (1) conditioning leads to rapid and transient chemokine upregulation in GVHD target tissues before the time of GVHD-associated T-cell infiltration; (2) conditioning intensity and mouse strain influence chemokine expression in GVHD target organs; and (3) compared with syngeneic bone marrow transplantation, allogeneic bone marrow transplantation led to marked amplification of chemokine expression in GVHD target organs after myeloablative conditioning. This is also reflected by chemokine protein expression that is measured in the serum and colon. Intestines showed the greatest sensitivity to conditioning intensity, and chemokines affecting T-helper type 1 cells (eg, interferon gamma-inducible protein 10 [CXCL10]) were most strongly expressed there after conditioning and during GVHD. However, severity of GVHD was not significantly different between recipients of CXCR3+/+ or CXCR3-/- splenocytes, indicating that this chemokine pathway does not play a critical role. In summary, our data show that conditioning and recipient strain influence chemokine expression in GVHD target organs and that GVH alloreactivity markedly amplifies this expression, thus contributing to the inflammatory cascade associated with tissue GVHD.

Animals↗
PubMed2005

Activation of transcriptional activities of AP1 and SRE by a novel zinc finger protein ZNF445.

Zinc finger proteins play important roles in various cellular functions, including cell proliferation, differentiation, and apoptosis. Mitogen-activated protein kinase (MAPK) signal transduction pathways are one of the most common mechanisms in eukaryotic cell regulation. Many transcription factors are important targets of MAPKs. In this study, we identified a novel gene encoding a zinc finger protein named ZNF445. The ZNF445 mRNA consists of 9105 nucleotides and has a 1031-amino acid open reading frame. The predicted 119-kDa protein contains a leucine-rich region (LER or SCAN domain) at the N-terminus, followed by a well-conserved Krüppel-associated box (KRAB) domain. At the C-terminus of the protein, there are 14 C2H2 (Cys2-His2) zinc finger motifs. ZNF445 gene is mapped to chromosome 3p21.32. Northern blot analysis indicates that a 9.1 kb transcript specific for ZNF445 is expressed in uterus, thymus, small intestine, colon, pancreas, peripheral blood leukocyte, and especially at a higher level in the testis and skeletal muscle in human adult tissues. ZNF445 protein was located in the nucleus when overexpressed in cultured cells. Reporter gene assays showed that ZNF445 is a transcriptional repressor, and overexpression of ZNF445 in the HEK 293T cells activates the transcriptional activities of AP1 and SRE. Deletion studies showed that the SCAN domain of ZNF445 may be involved in this activation. Furthermore, we found that expression of ZNF445 can increase p42/44 MAPK, MEK and Raf-1 phosphorylation. These results clearly indicate that ZNF445 is a member of the zinc finger transcription factor family and may function in MAPK pathway through Raf-1/MEK/p42/44 MAPK signals.

Amino Acid Sequence↗
PubMed2004

Optical coherence tomography in the gastrointestinal tract.

Conventional gastrointestinal endoscopic instruments have provided ready access to the mucosal surface of the esophagus, stomach,small intestinal, colon, bile duct, and pancreatic duct. The evolution of endoscopic ultrasonography has provided an additional dimension to the clinical application of modern endoscopy and imaging technology.

Endoscopy, Gastrointestinal↗
PubMed2004

Identification and characterization of NBEAL1, a novel human neurobeachin-like 1 protein gene from fetal brain, which is up regulated in glioma.

The Beige and Chediak-Higashi (BEACH) domain is highly conserved in a large family of eukaryotic proteins, and is crucial for their functions in vesicle trafficking, membrane dynamics and receptor signaling. From a fetal brain cDNA library, we isolated a cDNA of 3858 bp encoding a novel human BEACH protein, which was named as human neurobeachin-like 1 (NBEAL1) gene. The cDNA had an open reading frame (ORF) of 3006 bp encoding a putative 1001 amino acid protein. The NBEAL1 gene was located on human chromosome 2q33-2q34 and consisted of 25 exons spanning about 73 kb of the human genome. PSORT analysis indicated that the NBEAL1 protein contained a vacuolar-targeting motif ILPK, which suggested the protein might be located in the cell lysosome. The expression pattern was examined by reverse transcription/polymerase chain reaction (RT-PCR), which showed that the transcripts were highly expressed in the human brain, kidney, prostate, and testis while lowly in the ovary, small intestine, colon and peripheral blood leukocyte. In addition, the RT-PCR result of and Northern blot showed that the novel gene was highly expressed in the biopsies of different grade glioma, especially in that of lower grade ones, which suggested it might be correlative with the glioma.

Adolescent↗
PubMed2005

In vivo relevance of two critical levels for NAD(P)H:quinone oxidoreductase (NQO1)-mediated cellular protection against electrophile toxicity found in vitro.

NAD(P)H:quinone oxidoreductase (NQO1)-mediated detoxification of quinones is suggested to be involved in cancer prevention. In the present study, using transfected CHO cells, it was demonstrated that the relation between NQO1 activity and the resulting protection against the cytotoxicity of menadione shows a steep dose-response curve revealing a 'lower protection threshold' of 0.5mumol DCPIP/min/mg protein and an 'upper protection threshold' at 1mumol DCPIP/min/mg protein. In an additional in vivo experiment it was investigated how both in vitro critical activity levels of NQO1, relate to NQO1 activities in mice and man, either without or upon induction of the enzyme by butylated hydroxyanisol (BHA) or indole-3-carbinol (I(3)C). Data from an experiment with CD1 mice revealed that base-line NQO1 levels in liver, kidney, small intestine, colon and lung are generally below the observed 'lower protection threshold' in vitro, this also holds for most human tissue S-9 samples. To achieve NQO1 levels above this 'lower protection threshold' will require 5-20 fold NQO1 induction. Discussion focuses on the relevance of the in vitro NQO1 activity thresholds for the in vivo situation. We conclude that increased protection against menadione toxicity can probably not be achieved by NQO1 induction but should be achieved by other mechanisms. Whether this conclusion also holds for other electrophiles and the in vivo situation awaits further definition of their NQO1 protection thresholds.

Animals↗
PubMed2006

Novel surface polypeptides of Campylobacter jejuni as traveller's diarrhoea vaccine candidates discovered by proteomics.

Campylobacter jejuni is one of the most common causes of traveller's diarrhoea and food poisoning, therefore development of a vaccine is important. Using biochemical fractionation and mass spectrometry analysis, we identified more than 110 surface polypeptides. Eight C. jejuni identified surface proteins were expressed in Escherichia coli and purified. Mice were immunized with different doses of these purified proteins and challenged orally with C. jejuni strains ML1 and ML53. The degree of protection of mice was tested by intestinal colonization. At least two groups of mice vaccinated with purified proteins clear the infection faster than control mice. Here, we present the use of a proteomics based approach for the identification of novel protein based C. jejuni vaccines for the first time.

Animals↗
PubMed2006

Escherichia coli Shiga toxin 1 enhances il-4 transcripts in bovine ileal intraepithelial lymphocytes.

Shiga toxin 1 (Stx1) blocks the activation of bovine peripheral and intraepithelial lymphocytes (IEL), implying that the toxin has the potential to retard the host's immune response during intestinal colonization of cattle with human pathogenic Stx-producing Escherichia coli (STEC). Since Stx1 does not eliminate affected lymphocytes by causing cellular death, we assumed that Stx1 disturbs the integrity of the immune regulatory network. We therefore assessed the impact of Stx1 on the expression of selected chemokine and cytokine genes in vitro by real-time RT-PCR and by quantitation of intracellular cytokine proteins. While Stx1 did not alter the amount of mRNA specific for interleukin (IL)-2, IL-10, gamma interferon (IFN-gamma), transforming growth factor beta (TGF-beta), IL-8, 10kDa interferon inducible protein (IP-10), and monocyte chemoattractant protein 1 (MCP-1) in cultured ileal IEL (iIEL), minute concentrations of Stx1 led to an up to 40-fold increase of il-4 transcripts within 6-8h of incubation. Comparative experiments with peripheral lymphocytes revealed that the effect was specific for iIEL. The enhancement of il-4 transcripts in iIEL was not accompanied by apoptosis but required the enzymatic activity of the holotoxin. Nevertheless, iIEL retained their ability to synthesize proteins in the presence of Stx1: 40% of iIEL could be stimulated to synthesize IFN-gamma while less than 10% expressed IL-4 or TGF-beta. Furthermore, iIEL were found to produce granulocyte chemoattractants, but the release of these substances was not different in iIEL cultures incubated with or without Stx1. Although Stx1 did not affect the numbers of iIEL producing either cytokine, these findings point to an altered responsiveness of IEL during bovine STEC infections and shed light on the initial effects Stx1 exerts on the local adaptive immune system.

Animals↗
PubMed2003

Diarrhea caused by enterotoxigenic Escherichia coli infection of humans is inhibited by dietary calcium.

BACKGROUND & AIMS: In several rat infection experiments, we have shown that dietary calcium inhibits intestinal colonization and translocation of invasive salmonella. The aim of the present study was to find out whether calcium is also protective against enterotoxigenic Escherichia coli (ETEC) infection. This was first tested in our rat model and subsequently verified in a human infection study. METHODS: Rats were fed a purified diet with either a low or a high amount of calcium phosphate and orally infected with ETEC. In addition, a parallel, double-blind, placebo-controlled intervention study of 3 weeks was performed with 32 healthy men. Subjects largely maintained their habitual diet and consumed either regular milk products (calcium supply, 1100 mg/day) or placebo milk products (calcium supply, 60 mg/day). On day 10, subjects ingested a live but attenuated ETEC strain (strain E1392/75-2A), able to induce mild although short-lived symptoms. Primary outcomes studied were infection-induced diarrhea (total fecal output and relative fecal dry weight) and fecal mucin excretion. RESULTS: In humans, ETEC induced diarrhea in both groups, in that total fecal output doubled and mean relative fecal dry weight dropped from 25% to 20%. Additionally, fecal mucin excretion was increased in both groups. All these fecal parameters were completely normalized in the calcium group on the second infection day, in contrast to the placebo group, which recovered on the third infection day. Likewise, supplemental calcium inhibited ETEC colonization and diarrhea in rats. CONCLUSIONS: Calcium in milk products improves human resistance to ETEC infection as it inhibits infectious diarrhea.

Adult↗
PubMedDate not supplied

Adequacy of disposable biopsy forceps for gastrointestinal endoscopy: a direct comparison with reusable forceps.

Disposable plastic biopsy forceps were compared prospectively to reusable stainless steel forceps. Thirty consecutive patients underwent a total of 249 biopsies, 124 with the disposable forceps, and 125 with reusable forceps. Biopsy locations included the esophagus, stomach, small intestine, colon, and common bile duct. Specimens were compared microscopically to determine overall surface area, depth, adequacy, and diagnostic result. The disposable biopsy forceps yielded specimens which were 37% smaller when compared with the reusable forceps. In five of the comparisons, minor differences in histological findings were noted between the two groups of biopsy specimens, but these differences did not alter the pathological diagnosis. However, in three cases in which superficial specimens were obtained, an underlying carcinoma was missed with the disposable forceps. Our study documents the utility of disposable biopsy forceps for mucosal lesions. In addition, there were 11 mechanical failures in 38 biopsy attempts with the plastic biopsy forceps. These forceps appear to be limited in their capacity to obtain adequate specimens from firm tissue or when submucosal biopsy samples are required, and they will require refinements in design to duplicate specimen quality obtained by traditional reusable forceps. Disposable forceps are particularly suitable for biopsy of mucosal lesions in patients with possible communicable disease, and they should help to reduce cross-contamination in the gastroenterology laboratory.

Biopsy↗
PubMed1975

An outbreak og gastroenteritis due to E. coli 0142 in a neonatal nursery.

A nursery outbreak of gastroenteritis casued by Escherichia coli 0142/K86/H6 is described. Over a period of nine months, 59 epidemiologically linked cases of diarrhea occurred, including 21 intractable cases with four deaths. The epidemic strain, which was not agglutinated by commerical diagnostic antisera, was isolated from the hands of personnel in five instances directly incriminated hand carriage as the mode of spread. Acquisition of illness, which was especially high among low-birth-weight infants less than 17 days old, did not correlate with any treatment modality investigated and appeared to be related to a host factor. Noninvasive small intestinal colonization, production of enterotoxin, and multiple antibiotic resistance of the epidemic strain were demonstrated and helped to explain the intractability of clinical illness in many infants, despite intensive parenteral antibiotic therapy. Surveys of fecal coliforms on the hands of nursery personnel revealed no change in prevalence after introduction of a policy of "triple" handwashing with 3 percent hexachlorophene soap, but a significant decrease occurred during the use of disposable gloves. The frequent occurrence of E. coli 0142 in throat swabs of affected infants suggested that pharyngeal colonization may serve as an important diagnostic clue in E. coli diarrhea.

Age Factors↗
PubMed1999

Failure of pre-diarrheal antibiotics to prevent hemolytic uremic syndrome in serologically proven Escherichia coli O157:H7 gastrointestinal infection.

A girl had hemolytic uremic syndrome after Escherichia coli O157:H7 infection, despite pre-diarrheal administration of an antibiotic that prevented detectable intestinal colonization. This report casts doubt on the advisability of antibiotic therapy for E coli O157:H7 infections and has implications for our understanding of the mechanism of this disorder.

Adult↗
PubMed1998

Simultaneous augmentation cystoplasty and artificial urinary sphincter placement: infection rates and voiding mechanisms.

PURPOSE: Simultaneous augmentation cystoplasty and artificial urinary sphincter placement have recently been reported to be associated with a high incidence of infection. We reviewed our results to define the infection rate and outline the mechanisms of voiding in our patient population. MATERIALS AND METHODS: A total of 29 patients underwent a simultaneous procedure. The etiology of lower urinary tract disease was exstrophy in 14 patients, myelomeningocele in 10, lipomeningocele in 3, spinal cord injury in 1 and radical retropubic prostatectomy in 1. We used 19 gastric, 5 ileal and 5 colonic intestinal segments. Average followup was 33 months. All patients were followed for a minimum of 2 years. Preoperatively all cases had mechanical bowel preparation and documented sterile urine cultures or treated bacteriuria. RESULTS: Infection developed in 2 patients (6.9%) necessitating artificial urinary sphincter removal at 1 week and 9 months. There were no infections associated with gastrocystoplasty. Clean intermittent catheterization was required in 21 patients, while the remaining 8 voided spontaneously. Of the 8 patients 4 were catheterized at least once daily to monitor residual urine volumes. Of all patients 5 were catheterized with a gastric tube, 5 with an appendicovesicostomy and 14 per urethra. CONCLUSIONS: A simultaneous procedure was associated with an acceptable prosthetic infection rate and gastric segments were associated with the lowest incidence of infection. The minority of patients voided spontaneously. The combination procedure was effective in achieving continence. However, in the future a nonprosthetic means of providing urethral resistance may provide better treatment.

Adolescent↗
PubMed2003

Robotics and general surgery.

Robotics are now being used in all surgical fields, including general surgery. By increasing intra-abdominal articulations while operating through small incisions, robotics are increasingly being used for a large number of visceral and solid organ operations, including those for the gallbladder, esophagus, stomach, intestines, colon, and rectum, as well as for the endocrine organs. Robotics and general surgery are blending for the first time in history and as a specialty field should continue to grow for many years to come. We continuously demand solutions to questions and limitations that are experienced in our daily work. Laparoscopy is laden with limitations such as fixed axis points at the trocar insertion sites, two-dimensional video monitors, limited dexterity at the instrument tips, lack of haptic sensation, and in some cases poor ergonomics. The creation of a surgical robot system with 3D visual capacity seems to deal with most of these limitations. Although some in the surgical community continue to test the feasibility of these surgical robots and to question the necessity of such an expensive venture, others are already postulating how to improve the next generation of telemanipulators, and in so doing are looking beyond today's horizon to find simpler solutions. As the robotic era enters the world of the general surgeon, more and more complex procedures will be able to be approached through small incisions. As technology catches up with our imaginations, robotic instruments (as opposed to robots) and 3D monitoring will become routine and continue to improve patient care by providing surgeons with the most precise, least traumatic ways of treating surgical disease.

Adrenalectomy↗
PubMed1988

Cell- and tissue-specific expression of a 34,000-molecular-weight peptide growth factor in humans.

A 34,000-dalton peptide growth factor that we originally identified in human placental trophoblasts and in certain carcinomas was shown to be expressed in several normal human tissues. A highly specific antibody to the trophoblast-derived growth factor was used in an immunoperoxidase staining technique to identify the immunoreactive peptide in tissue sections. Immunoreactivity was seen in the adrenal cortex, Leydig cells of the testes, and follicular cells of the thyroid. In addition, strong staining was seen in the ducts and terminal ductules of the pancreas, in glandular epithelium of the prostate, in the chief cells of the stomach, and in the columnar epithelium of the trachea and bronchus of the lung. Certain tissues were negative for the peptide, including the adrenal medulla, liver, esophagus, small intestine, colon, bladder, lymph node, spleen, bone marrow, and thymus. Thus, the expression of the peptide depends on cell lineage and the state of differentiation; tissues of hematopoietic lineage are devoid of the 34,000-dalton peptide, whereas some of the major hormone-secreting tissues that are under pituitary control show the highest immunoreactivity.

Adult↗
PubMed2001

Nucleotide sequence and cell cycle-associated differential expression of ZF5128, a novel Kruppel type zinc finger protein gene.

The nucleotide sequence of the ZF5128 gene, encoding a novel Kruppel type zinc finger protein, has been determined. The ZF5128 gene has a predicted 553-amino acid open reading frame, encoding a putative 61 kDa zinc finger protein. The N-terminus of the ZF5128 coding region has a well-conserved Kruppel-associated box (KRAB) domain that consists of KRAB box A and B, whereas the C-terminus contains a Kruppel type C2H2 zinc finger domain possessing nine C2H2 zinc finger motifs in tandem arrays with the highly conserved space region of the H/C-link. Each C2H2 zinc finger motif has a typical consensus sequence of CX2CX3FX5LX2HX3H. A 3.2 kb transcript specific for ZF5128 was expressed at high levels in the spleen, thymus, and peripheral blood leukocyte, and weakly expressed in the prostate, ovary, small intestine, colon (mucosal lining), placenta, lung, and pancreas. Although there was no detectable ZF5128 mRNA in unstimulated human peripheral T cells, it was first detectable 1.5 h after activation by anti-CD3 plus anti-CD28, and reached a maximum in 25-30 h. During the cell cycle progression of Jurkat T cells, the expression of ZF5128 mRNA appeared to be induced in G1 and reached a maximum in the S phase, but declined as the cells entered the G2/M phase. The 12-O-tetradecanoylphorbol 13-acetate-induced monocytic differentiation of U937, which also resulted in growth arrest, down-regulated the expression of ZF5128 mRNA. Taken together, these results indicate that ZF5128 is a novel gene encoding a Kruppel type C2H2 zinc finger protein and is regulated at the transcriptional level depending on tissue type and the cell cycle status to support cell proliferation.

Amino Acid Sequence↗
PubMed2002

Expression of the human homologue of the small nucleolar RNA-binding protein NHP2 gene during monocytic differentiation of U937 cells.

The human homologue of yeast NHP2, which is known to be a core protein component of yeast H/ACA small nucleolar ribonucleoprotein particles (snoRNPs), was identified by ODD-PCR as a 313-bp cDNA fragment exhibiting a distinct decrease in its expression level during TPA-induced differentiation of promonocytic U937 into monocytes and macrophages. Sequentially, a full-length cDNA of human NHP2 was isolated and the nucleotide sequence was determined. The NHP2 gene has a predicted 153 amino acid open reading frame, encoding 17.2 kDa protein that shares 38.4% and 44.4% identity with Saccharomyces cerevisiae NHP2 and Schizosaccharomyces pombe nhp2+, respectively. The TPA-induced differentiation of U937 cells, which also resulted in growth arrest, abruptly down-regulated the expression of NHP2. Removal of TPA restored cell growth through the retrodifferentiation process and subsequent expression of NHP2. NHP2 mRNA was markedly expressed in most tumor cells including Jurkat, K562, HL-60, U937, and HeLa S3. In healthy human tissues, NHP2 mRNA was expressed at high levels in spleen, thymus, prostate, testis, ovary, small intestine, colon (mucosal lining), heart, brain, placenta, skeletal muscle, kidney and pancreas, and at low levels in liver, and very weakly in peripheral blood leukocyte and lung. NHP2 mRNA, undetectable in human peripheral T cells, was induced at a maximum level between late G(1) and S phase after polyclonal activation. The expression of NHP2 mRNA during the cell cycle progression of Jurkat T cells also reached a maximum between late G(1) and S phase. These results indicate that the human NHP2 gene may be regulated at the transcription level depending on tissue specificity and cellular proliferative status, and that the down-regulation of NHP2 expression during induced differentiation of U937 cells may result from the growth arrest accompanying the differentiation.

Amino Acid Sequence↗
PubMed1997

Cloning and expression of human mitotic centromere-associated kinesin gene.

The human homologue of the hamster mitotic centromere-associated kinesin (HsMCAK) gene containing a central type motor domain was isolated from a Jurkat T-cell derived cDNA library. The HsMCAK gene has a predicted 723 amino acid open reading frame, encoding a 81 kDa protein that shares 79.2% homology with hamster MCAK. Unstimulated T lymphocytes contained no detectable HsMCAK-specific mRNA. Activation of resting T-cells by immobilized anti-CD3 resulted in the expression of a 2.9-kb transcript during the S phase of the cell cycle. The TPA-induced monocytic differentiation of U937 which also results in growth-arrest abruptly downregulates the expression of HsMCAK. Removal of TPA restored the growth of the cell through the retrodifferentiation process and the subsequent expression of HsMCAK. HsMCAK is expressed in tissues containing dividing cells, such as thymus, testis, small intestine, colon (mucosal lining), and placenta. These results suggest that the expression of HsMCAK is first detected in early S phase to support the proliferative response and is strictly regulated at the transcriptional level.

Amino Acid Sequence↗