"Band-snare" resection of small rectal carcinoid tumors.
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Carcinoid Tumor↗
Biomedical subjects
S Schreiber
Publications and source records attributed to S Schreiber.
The atypical neuroleptics clozapine and olanzapine differ regarding their antinociceptive mechanisms and potency.
Using the mouse tail-flick assay, we evaluated the antinociceptive effect and the interaction with the opioid, adrenergic, and serotonergic systems of the two "atypical" neuroleptic agents clozapine and olanzapine. Clozapine induced a potent antinociceptive effect in a dose-dependent manner with ED50 of 8.7 mg/kg. This effect was antagonized by the nonselective opioid antagonist naloxone (p < 0.05), implying an opioid mechanism of action involved in clozapine-induced antinociception. Further evaluation demonstrated the involvement of micro1-, micro2-, kappa1- opioid receptor subtypes and of alpha2-adrenoreceptors in clozapine antinociception but not the serotonin receptors. Olanzapine induced a weak antinociceptive effect. The highest effect found was a 50% antinociception following an injection of 10 mg/kg. As the olanzapine dose increased beyond 10 mg/kg, latencies declined almost back to baseline. Yohimbine (an alpha2-adrenoreceptor antagonist) significantly reduced olanzapine's antinociceptive effect almost completely (to 10%; p < 0.05), while both naloxone and metergoline (a nonselective 5-HT receptor antagonist) reduced it only partially. These results indicate the possible involvement of the alpha2-adrenoreceptors in olanzapine antinociception and to a less extent the involvement of opioid and serotonergic receptors. Although both clozapine and olanzapine are dibenzodiazepines with similar "atypical" antipsychotic properties, it seems that they differ notably not only regarding their hematological side effects, but regarding their interaction with the opioid system as well.
Analgesics↗
Proliferation markers in different types of clinically non-secreting pituitary adenomas.
160 clinically non-secreting pituitary adenomas were examined in regard to their expression of the markers PCNA, bcl2, Ki 67 in the mib-1 modification and p53 which are still under investigation for their relevance to cell proliferation. The series contained 60 null cell adenomas, 60 oncocytomas and 40 gonadotroph adenomas. The groups that showed a definitely negative and definitely positive staining were evaluated in regard to their further characteristics such as size, invasiveness and recurrence. PCNA showed a highly represented immunostaining index throughout the groups, but not correlation between the PCNA index and an increased recurrence rate could be found. The staining for bcl2 was only rarely positive and only in a small number of cells. No correlation with the clinical data could be seen. We found a significant higher rate of staining in the invasive adenomas in the group of null cell adenomas and oncocytomas for Ki 67, especially in those adenomas expressing p53. p53 positivity was restricted to the invasive adenomas but was found only in 20% of all invasive adenomas. These data confirm in a sufficiently large series of clinically endocrine inactive pituitary adenomas, that p53 and Ki67 immunohistology is useful in evaluating the aggressive behavior of clinically silent pituitary adenomas. Nevertheless, negative results do not exclude clinically relevant invasive behavior.
Adenoma↗
Production of IL-12 in gastritis relates to infection with Helicobacter pylori.
Increased production of proinflammatory cytokines, including tumour necrosis factor-alpha (TNF-alpha), IL-1beta, IL-6 and IL-8, has been demonstrated in Helicobacter pylori-associated gastric mucosal inflammation. IL-12, a newly characterized cytokine, is thought to be a key mediator in host responses to bacterial infections. The aim of this study was to investigate differences in cytokine patterns between H. pylori-positive and -negative gastritis and normal mucosa. Secretion of IL-12, TNF-alpha, IL-1beta, IL-6, IL-8 and IL-10 was measured in 176 patients with chronic gastritis in whole biopsy cultures. Gastritis was graded for chronic inflammation or acute inflammatory activity, respectively, according to the Sydney system. Biopsies with similar scores were matched for analysis from H. pylori-infected and non-infected patients. Secretion of IL-12 was significantly increased in H. pylori-associated gastritis in comparison with H. pylori-negative gastritis (P < 0.0001). In contrast, secretion of TNF-alpha, IL-1beta, IL-6, and IL-8 correlated with the degree of inflammation but was not different between H. pylori-positive and -negative patients. Moreover, IL-10 secretion was found to be higher in H. pylori-positive than in H. pylori-negative patients. IL-12 may play a specific role in H. pylori-associated gastric disease, whereas production of the proinflammatory cytokines TNF-alpha, IL-1beta, IL-6 and IL-8 does not seem to be restricted to H. pylori-induced inflammation. The contra-inflammatory cytokine IL-10 may be a contributor to the chronicity of H. pylori-associated gastritis by impairing clearance of the pathogen.
Adult↗
A genomewide analysis provides evidence for novel linkages in inflammatory bowel disease in a large European cohort.
Inflammatory bowel disease (IBD) is characterized by a chronic relapsing intestinal inflammation, typically starting in early adulthood. IBD is subdivided into two subtypes, on the basis of clinical and histologic features: Crohn disease and ulcerative colitis (UC). Previous genomewide searches identified regions harboring susceptibility loci on chromosomes 1, 3, 4, 7, 12, and 16. To expand our understanding of the genetic risk profile, we performed a 9-cM genomewide search for susceptibility loci in 268 families containing 353 affected sibling pairs. Previous linkages on chromosomes 12 and 16 were replicated, and the chromosome 4 linkage was extended in this sample. New suggestive evidence for autosomal linkages was observed on chromosomes 1, 6, 10, and 22, with LOD scores of 2.08, 2.07, 2.30, and 1.52, respectively. A maximum LOD score of 1.76 was observed on the X chromosome, for UC, which is consistent with the clinical association of IBD with Ullrich-Turner syndrome. The linkage finding on chromosome 6p is of interest, given the possible contribution of human leukocyte antigen and tumor necrosis-factor genes in IBD. This genomewide linkage scan, done with a large family cohort, has confirmed three previous IBD linkages and has provided evidence for five additional regions that may harbor IBD predisposition genes.
Cohort Studies↗
Linkage of inflammatory bowel disease to human chromosome 6p.
Inflammatory bowel disease (IBD) is characterized by a chronic relapsing intestinal inflammation. IBD is subdivided into Crohn disease and ulcerative colitis phenotypes. Given the immunologic dysregulation in IBD, the human-leukocyte-antigen region on chromosome 6p is of significant interest. Previous association and linkage analysis has provided conflicting evidence as to the existence of an IBD-susceptibility locus in this region. Here we report on a two-stage linkage and association analysis of both a basic population of 353 affected sibling pairs (ASPs) and an extension of this population to 428 white ASPs of northern European extraction. Twenty-eight microsatellite markers on chromosome 6 were genotyped. A peak multipoint LOD score of 4.2 was observed, at D6S461, for the IBD phenotype. A transmission/disequilibrium test (TDT) result of P=.006 was detected for D6S426 in the basic population and was confirmed in the extended cohort (P=.004; 97 vs. 56 transmissions). The subphenotypes of Crohn disease, ulcerative colitis, and mixed IBD contributed equally to this linkage, suggesting a general role for the chromosome 6 locus in IBD. Analysis of five single-nucleotide polymorphisms in the TNFA and LTA genes did not reveal evidence for association of these important candidate genes with IBD. In summary, we provide firm linkage evidence for an IBD-susceptibility locus on chromosome 6p and demonstrate that TNFA and LTA are unlikely to be susceptibility loci for IBD.
Alleles↗
Genetics and inflammatory bowel disease.
Genetic factors have a definite role in the etiology of inflammatory bowel disease (IBD). The mode of inheritance suggests a polygenic disease with the penetrance of the genetic factors being strongly influenced by the lifestyle of an industrialized society. Molecular techniques, which have become available through the progress of the human genome project, allowed a first series of linkage studies in pairs of affected siblings with IBD, which suggested multiple genomic susceptibility regions. These regions are still large, but considerable progress is being made toward the identification of actual disease genes. It is hoped that an understanding of the genetic etiology of IBD will lead to enhanced diagnostic procedures, more effective therapeutic interventions, and preventive strategies in the future.
Journal Article↗
Blood flow velocities in the vertebral veins of healthy subjects: a duplex sonographic study.
Along with the jugular veins, the vertebral veins serve as an important pathway for venous blood returning from the brain. In this study, the authors report duplex sonographic findings in 138 healthy subjects without central nervous disease. Successful insonation was possible in 70.7% of all examined vessels. Bilateral insonation was achieved in 86 subjects (62.3%). Only 1 vertebral vein was detected in 23 persons (16.7%), whereas no vein was found in 29 persons (21%). The authors observed a marked variation of peak flow velocities ranged (5-81 cm/s, mean +/- standard deviation, 23.9 +/- 12.3 cm/s). No significant gender-related or side-to-side differences or age influences on flow velocities were detected. The authors' findings may be of relevance when discussing flow velocities in the vertebral veins in cases of cerebrovenous disorders (e.g., dural sinus thrombosis) or in patients after neck dissection.
Adolescent↗
In vivo distribution of Helicobacter felis in the gastric mucus of the mouse: experimental method and results.
We describe a method that permits the collection of very small samples (2 nl) from precisely defined positions within the gastric mucus of anesthetized mice. This method was used to study the in vivo local distribution of bacteria within the mucus of Helicobacter felis-infected mice. A total of 200 samples from 40 mice were analyzed. Each sample was microscopically analyzed, within less than 1 min, as a native preparation. To avoid changes in bacterial location within the mucus after collection and to improve the counting accuracy, bacterial motility was blocked by adjusting the pH inside the collecting pipette to 4.5. The mucus in a collected sample was subdivided into three layers, an epithelial layer (the first 25 micron of mucus from the tissue-mucus interface), a luminal layer (the last 25 micron to the mucus-lumen interface), and the remaining central mucus layer. The volume of the analyzed segments in the sample was between 4 and 9 pl. The concentration of bacteria inside the epithelial mucus layer was 3,400 per nl, but it was only 50 per nl inside the central mucus layer. The mean distance of H. felis to the epithelial surface was 16 microm. A total of 75% of all H. felis bacteria resided in the mucus zone between 5 and 20 micron from the tissue surface, with no bacteria closer than 5 micron to the epithelial surface. This method permits the study of factors determining the density of colonization and distribution of bacteria along chemical gradients with a high precision.
Animals↗
Activation of nuclear factor kappaB as a target for anti-inflammatory therapy.
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Anti-Inflammatory Agents, Non-Steroidal↗
Preactivated peripheral blood monocytes in patients with essential hypertension.
The purpose of this study was to investigate the possible involvement of human peripheral blood monocytes in the pathology of hypertensive disease. We determined the in vitro secretion patterns of proinflammatory cytokines obtained from isolated peripheral monocytes from normal controls and from hypertensive patients either after in vitro stimulation with angiotensin II (Ang II) with or without preincubation with an Ang II type 1 receptor antagonist (losartan) or after stimulation with lipopolysaccharide. Blood samples were obtained from 22 patients with essential hypertension (before any drug administration or after interruption of antihypertensive therapy) and from 24 normotensive healthy individuals used as a control group. Peripheral blood monocytes were isolated by density gradient centrifugation and plastic adherence. The state of monocyte activity was determined by the capacity to secrete tumor necrosis factor-alpha (TNF-alpha), interleukin-1beta (IL-1beta), and interleukin-6, (IL-6) either spontaneously or after stimulation. Cytokine concentrations were determined in culture supernatants by specific ELISA. Proinflammatory cytokine levels were assessed by semiquantitative reverse transcribed polymerase chain reaction. After stimulation with Ang II, the IL-1beta secretion of peripheral blood monocytes was significantly increased in hypertensive patients versus healthy individuals (P<0.05). In contrast, in monocytes preincubated with losartan before exposure to Ang II, IL-1beta secretion was diminished in both groups to comparable levels. The secretion of IL-1beta and TNF-alpha was significantly increased in peripheral blood monocytes from hypertensive patients versus healthy individuals after stimulation with lipopolysaccharide (TNF-alpha, P<0.02; IL-1beta, P<0.05). Upregulation of IL-1beta and TNF-alpha secretion in peripheral blood monocytes from hypertensive patients was also seen at the RNA level. Our results indicate preactivated peripheral blood monocytes in hypertensive patients. Ang II may be directly involved in the process of monocyte activation.
Adult↗
Anti-TNF antibody in Crohn's disease--status of information, comments and recommendations of an international working group.
The chimeric anti-TNF antibody Remicade (Infliximab) has recently been approved for human use by the FDA and is now available on the market. Since there is considerable interest in this kind of treatment among patients with Crohn's disease, an international working group has summarized the presently available information about efficacy, side effects and possible problems of this treatment. Studies show that Remicade is effective in the treatment of active Crohn's disease, maintaining remission and fistulae. The working group does not see Infliximab as a first-line treatment for Crohn's disease. It may be used in active phase recurrent disease, chronic active disease and fistulae if standard treatment was not successful. For the surveillance special attention has to be given to the unknown malignancy rate of Infliximab. Infusion should be performed in an institution, routinely performing intravenous infusions and a two-hour surveillance of the patients should be guaranteed to recognize anaphylactic reactions or acute side effects. There is presently no information indication that the combination with immunosuppressants might increase risks or side effects of this treatment. Due to the limited information available the working group would prefer to use Remicade in studies only and recommends central collection and documentation of all data on efficacy and side effects for the next year.
Antibodies, Monoclonal↗
The nature of the cell in multiple myeloma.
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Aneuploidy↗
Lack of clinical efficacy of additional factor XIII treatment in patients with steroid refractory colitis. The Factor XIII Study Group.
Patients with active ulcerative colitis have decreased levels of factor XIII (FXIII) activity, which is important for woundhealing. Recent uncontrolled studies claimed a beneficial effect of Factor XIII on clinical symptoms of ulcerative colitis, in particular intestinal bleeding. The objective of this trial was to evaluate the benefits of additional FXIII treatment in steroid-refractory patients with ulcerative colitis in a prospective, double blind, placebo-controlled study. A total of 28 patients were enrolled between October 1994 and January 1997. Primary objective of this study was the time until cessation of visible intestinal bleeding with 14 days after the start of treatment. Patients were treated for ten days either by i.v. application of FXIII concentrate or by placebo. The analysis of the primary efficacy criterion, cessation of intestinal bleeding, by a planned interim analysis showed no significant differences between the treatment groups (p = 0.8). This resulted in the termination of the study. The same applied to the CAI score. No patient in both treatment groups reached remission according to the colo-/-sigmoidoscopy score. Due to the high number of patients (16 of 28) who had to be excluded from the per-protocol analysis (e.g. changes to the concomitant medication) only the intention-to-treat population was analyzed. Overall the study showed no beneficial effect of additional FXIII treatment on active steroid-refractory ulcerative colitis. These results do not confirm previous open label studies which had reported a significant improvement of clinical symptoms.
Adolescent↗
Micropipette system for sampling and injecting small volumes.
We have developed a micropipette system that allows sampling of preset volumes of liquids and injection of preset small amounts of liquids, using thermal expansion of an oil phase in a micropipette, achieved by increasing or decreasing the current applied to heat the shaft of the micropipette. The system has been tested to inject or collect volumes of about 20 nl, but smaller and larger volumes are possible. The amount injected or collected for a given temperature step of the micropipette is largely independent of the physical properties, e.g. of viscosity, into which the sample is injected or from which it is collected. The pipette tip is not measurably heated when heating the shaft for injection or collection, thus avoiding damage of the biological material into which the injection occurs or from which it is sampled.
Microinjections↗
The antinociceptive effect of moclobemide in mice is mediated by noradrenergic pathways.
Moclobemide is an antidepressant which affects the monoaminergic neurotransmitter system through a reversible inhibition of monoamine oxidase (MAO), preferentially type A. We examined the antinociceptive effects of moclobemide alone and in conjunction with specific opioid, adrenergic and serotonergic antagonists, using the mouse-tail flick test. Intraperitoneal moclobemide produced a dose-dependent antinociceptive effect with an ED50 of 69.1 mg/kg. Tests with selective antagonists yielded positive results only for yohimbine (P < 0.001), implying a noradrenergic mechanism of action in the moclobemide antinociceptive effect. This was confirmed by the coadministration of moclobemide with inactive doses of prototype agonists of the opioid, adrenergic and serotonergic systems. Only clonidine, an alpha2 agonist, significantly shifted (8-fold) the dose response curve of moclobemide. We conclude that there is a selective involvement of the alpha2 adrenergic pathways in the moclobemide-induced antinociceptive effect and a lesser involvement (if any) of the opioid, serotonergic and alpha1 adrenergic mechanisms. More research is needed to establish a possible role for moclobemide in pain management.
Analgesics↗
Chimeric monoclonal antibody cA2 to tumor necrosis factor alpha for Crohn's disease.
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Anti-Inflammatory Agents, Non-Steroidal↗
Pouchitis: pathophysiology and treatment.
Pouchitis is a potential complication after proctocolectomy and restorative ileoanal anastomosis. It is more frequent in UC than in familial polyposis. Little is known about the etiopathology of pouchitis. Risk factors include the presence of extraintestinal manifestations, primary sclerosing cholangitis, cessation of smoking, and previous course of disease. A host of pathophysiological pathways have been identified as potential mechanisms of pouchitis, which include inflammatory mediators, adhesion molecules, oxygen radical species, p-ANCA, and short-chain fatty acids. The microflora in the pouch may also be an important factor in causing inflammation. The risk of developing cancer in cases of pouchitis has not been established as clearly as in those of UC. Particular attention should be paid to patients who have remaining anorectal mucosa after pouch construction. Experience in the treatment of chronic relapsing and chronic refractory pouchitis is limited. The continuation of conventional anti-inflammatory treatment is successful only in a small percentage of patients. New biological response-modifying therapies which target novel immunoregulatory molecules in IBD will also have impact on the systemic and topical treatment of pouchitis.
Colitis, Ulcerative↗