Biomedical subjects

A Zinsmeister

Publications and source records attributed to A Zinsmeister.

8 recordsLinked to original sources

PubMed2000

Postpolypectomy lower GI bleeding: descriptive analysis.

BACKGROUND: Postpolypectomy hemorrhage may warrant intensive care monitoring, transfusions, and surgery. We sought factors predicting significant bleeding requiring blood transfusion and the benefits of critical care monitoring. METHODS: Patients with postpolypectomy bleeding between April 1989 and November 1996 were identified from a comprehensive GI bleeding database. Data included age, gender, medical history, medications, polyp characteristics, and polypectomy technique. Outcomes assessed included bleeding cessation, transfusion requirements, recurrent bleeding, length of stay, and death. RESULTS: There were 83 patients with a median age of 73 years (range 18 to 88 years; 56 men, 27 women). Comorbid conditions were common (71.1% cardiovascular, 43.4% musculoskeletal, 14.5% hematologic, 6.0% renal). Within 3 days of presentation, 32.5% had taken aspirin, 10.8% nonsteroidal anti-inflammatory drugs, 12.0% warfarin, and 12.0% corticosteroids; and within 1 day, 10.8% intravenous heparin, 7.2% subcutaneous heparin, and 7.2% dipyridamole. Fifty-seven percent of patients were hemodynamically stable. Sessile cecal polyps greater than 2 cm in diameter bled more commonly. The median number of units transfused was equal between critical care and noncritical care patients. Using age in the logistic regression model, no other variable was predictive of transfusion. Eighty patients (96.4%) received endoscopic therapy, 1 required embolization and 2 hemicolectomy. There was no significant difference in outcomes for patients managed in an intensive care unit versus a general medical floor. CONCLUSIONS: Postpolypectomy bleeding appears to have a predictable presentation and outcome. Advanced age seems to be predictive of transfusion requirement. Patient monitoring in an intensive care setting is not absolutely necessary.

Adolescent↗

PubMed1998

A multicenter investigation with interphase fluorescence in situ hybridization using X- and Y-chromosome probes.

Twenty-six laboratories used X and Y chromosome probes and the same procedures to process and examine 15,600 metaphases and 49,400 interphases from Phaseolus vulgaris-leucoagglutinin (PHA)-stimulated lymphocytes. In Part I, each laboratory scored 50 metaphases and 200 interphases from a normal male and a normal female from its own practice. In Part II, each laboratory scored 50 metaphases and 200 interphases on slides prepared by a central laboratory from a normal male and a normal female and three mixtures of cells from the male and female. In Part III, each laboratory scored 50 metaphases (in samples of 5, 10, 15, and 20) and 100 interphases (in samples of 5, 10, 15, 20, and 50) on new, coded slides of the same specimens used in Part II. Metaphases from male specimens were scored as 98-99% XY with no XX cells, and 97-98% of interphases were scored as XY with 0.04% XX cells. Metaphases from female specimens were scored as 96-97% XX with 0.03% XY cells, and 94-96% of interphases were scored as XX with 0.05% XY cells. Considering the data as a model for any probe used with fluorescence in situ hybridization (FISH), a statistical approach assessing the impact of analytical sensitivity on the numbers of observations required to assay for potential mosaicisms and chimerisms is discussed. The workload associated with processing slides and scoring 50 metaphases and 200 interphases using FISH averaged 27.1 and 28.6 minutes, respectively. This study indicates that multiple laboratories can test/develop guidelines for the rapid, efficacious, and cost-effective integration of FISH into clinical service.

Cytogenetics↗

PubMed1993

Transforming growth factor-beta 1 induces collagen IV gene expression in NIH-3T3 cells.

BACKGROUND: While recent studies have implicated transforming growth factor-beta 1 (TGF-beta 1) in the development of glomerular scarring, extraglomerular matrix production is frequently associated with glomerulonephritis and is an important determinant of disease progression. TGF-beta 1 may be an important mediator of extracellular matrix synthesis, both by glomerular and extraglomerular mesenchymal cells. TGF-beta 1-mediated collagen IV gene expression was studied in two mesenchymal cell lines. Initial studies were performed utilizing NIH-3T3 cells, a fibroblast-like line derived from murine embryo that has been used to study regulation of fibrillar collagen (collagen I and collagen III) synthesis by TGF-beta 1. Additional studies were performed using normal rat kidney cells (NRK-49F). EXPERIMENTAL DESIGN: Cells were grown in medium supplemented with 0.5% calf serum for 24 hours before treatment with TGF-beta 1. RNA was isolated after the addition of varying amounts of TGF-beta 1 to the cells in culture for varying periods of time, and collagen alpha 1(IV) RNA was quantitated by filter hybridization. Transcription of the alpha 1(IV) and alpha 2(IV) collagen genes was assessed by an in vitro transcription assay. Deposition of collagen IV was identified by immunoblotting. RESULTS: Induction of alpha 1(IV) gene expression by NIH-3T3 cells and by NRK-49F cells was first seen 2 to 4 hours after TGF-beta 1 treatment, and was maximal after 12 to 18 hours. Maximal induction was observed following addition of 5 ng/ml TGF-beta 1 to NIH-3T3 cells, and following addition of 10 ng/ml of TGF-beta 1 to NRK-49F cells. In the presence of cycloheximide, TGF-beta 1 induction of alpha 1(IV) mRNA was markedly attenuated in both cell lines, suggesting that this effect of TGF-beta 1 requires protein synthesis. TGF-beta 1 increased transcription of both the alpha 1(IV) and alpha 2(IV) collagen genes by NIH-3T3 cells. CONCLUSIONS: TGF-beta 1 induces collagen IV gene expression in both NIH-3T3 cells and normal rat kidney fibroblasts (NRK-49F cells). Further studies of cytokine-mediated transcriptional regulation of collagen IV, utilizing these cell lines, may provide important information regarding the role of extraglomerular matrix production in the progression of renal disease.

3T3 Cells↗

PubMed1991

Gastric leiomyosarcoma. Prognostic factors and surgical management.

Information on gastric leiomyosarcoma, such as important prognostic factors, patterns of disease recurrence, and optimal methods of treatment, are derived from limited patient experience. We address these questions, with specific focus on whether an advantage could be demonstrated for radical resection compared with wide local excision, by retrospectively investigating 53 patients who underwent surgical treatment at Mayo Clinic, Rochester, Minn. Abdominal pain and/or gastrointestinal bleeding associated with an intramural or exogastric mass were typical features of this disease. Only tumor size and histologic grade were statistically significant prognostic factors. With analysis of survival curves and patterns of recurrence, neither the addition of lymphadenectomy nor the wider tumor-free margins of a radical gastrectomy seemed superior to the more conservative local excision. Therefore, wide local excision remains the preferred treatment when technically feasible.

Adolescent↗

PubMed1987

Flow across the canine ileocolonic junction: role of the ileocolonic sphincter.

The role of the canine ileocolonic sphincter (ICS) in influencing transit of fluids and absorption of water in the ileum was assessed in loops with or without the ICS. Two sets of four dogs each were equipped with isolated ileal loops 40 cm long, attached to the intact bowel through a neuromuscular bridge. In one set, the loop included the ICS and it terminated in an end colostomy; in the other, the loop ended immediately proximal to the ICS, as an ileostomy. Electrical and mechanical signals were recorded from serosal electrodes and strain gauges, respectively, during perfusion of loops with an isotonic solution at rates from 0.7 to 10.0 ml/min. Loops without an ICS propelled fluid by steady, continuous flow at all rates of perfusion; loops with the ICS in place moved fluids in this way only at 10 ml/min. At greater rates of perfusion, fasting cycles of motility were inhibited in all loops and a random pattern of motility developed; this presumably facilitated more steady flow of fluids. At the slowest rate of perfusion, transit times were longer when the ICS was present, but at faster rates both loops showed similar transit times. Presence of the ICS was associated with increased volumes of fluid in the loop and increased absorption of water, especially when loops were perfused slowly. The canine ICS influences flow of saline and absorption in the terminal ileum, but only when flow rates are low.

Animals↗

PubMed1983

Motor responses to food of the ileum, proximal colon, and distal colon of healthy humans.

Intraluminal pressures and motility indexes were recorded from ileum, ascending colon, rectosigmoid colon, and rectum of 6 healthy men. Three different test meals were eaten at 5-hour intervals. During fasting, migrating motor complexes were identified in the ileum. In ascending colon, irregular, isolated peaks of pressure were common; when bursts of continuous activity occurred, their predominant frequency was 6/min. Regular contractile activity occurred in distal colon at a frequency of 2.5-3.5/min. although 3 subjects also demonstrated rates of 7/min. There were both synchronous and independent contractions of the rectosigmoid and rectum, and no temporal relationship was obvious between motor activities of ascending and distal colons. When the preprandial hour contained no migrating motor complex, all meals increased the ileal motility index by 50%. The motility index of ascending and rectosigmoid colons were enhanced by solid meals, but not by meals containing amino acids. We conclude that motor patterns in the colon vary regionally, both fasting and after food. Results obtained at one site of the large intestine should not be extrapolated to others.

Adult↗

PubMed1983

Abnormalities in gastrointestinal motor activity in patients with short bowels: effect of a synthetic opiate.

We have investigated the fasting and postprandial patterns of gastrointestinal pressure activity in a group of patients with extensive (greater than 100 cm) resections of the distal small bowel. Each short bowel patient was studied on 2 consecutive days with random single blind administration of either loperamide (6 mg at 5 h and at 30 min before the meal) or placebo, and 20 healthy controls were studied on single days (13 basal fasting, 7 placebo). During fasting, the duration of the interdigestive motor complex was significantly shorter in patients with short bowel syndrome (71.1 +/- 15.6 min vs. 109 +/- 7.8 min for controls, p less than 0.03); hence, the frequency of complexes was increased. The duration of phase 2 was strikingly shorter in patients (18.7 +/- 7.0 min vs. 52.9 +/- 8.5 min for controls, p less than 0.03). Gastric emptying and postprandial motor activity were identical in patients and controls. During fasting, loperamide prolonged phase 3 (7.6 +/- 2.2 min vs. 4.3 +/- 1.1 min for placebo, p less than 0.03). Postprandially, loperamide shortened the time from meal ingestion to the first phase 3 by 50% (p less than 0.003), and increased motility index and frequency of contraction in the gut (p less than 0.01). Thus, gut motor activity in the short bowel syndrome is characterized by more frequent interdigestive motor complexes, marked reduction in phase 2 activity, and a normal feeding pattern. Loperamide therapy increases feeding activity while at the same time shortening its duration.

Adult↗

PubMed1982

Relationship of motility to flow of contents in the human small intestine.

To measure simultaneously motility and flow of intestinal contents, a multilumen polyvinyl tube was passed by mouth in 10 healthy volunteers. Motility was recorded at five sites, spanning 100 cm of tube, to allow recognition of migrating motor complexes during fasting and during their disruption by food. Loci were designated as jejunal, ileal, and terminal ileal, as judged by length of tube in the intestine and by fluoroscopy. Flow of intestinal contents was measured by indicator (phenolsulfonphthalein) dilution over a 20-cm segment; flow was related to motility at the perfusion site. A liquid test meal of 400 ml and 600 kcal, containing polyethylene glycol 4000, was eaten after 6 h of fasting. During fasting, flow of intestinal contents was intermittent at all levels and varied with the presence of or absence of the activity front ("phase 3" of the migrating motor complex). The activity-front periods contributed 50% of total flow, but occupied less than one-third of the total recording time. Flow corrected for time was significantly greater with the presence of activity front than with phases 1 or 2 of the migrating motor complex (p less than 0.001). In addition, of 45 increments in flow of greater than 0.75 ml . min-1, the majority (82%) were associated with an activity front. The flow rate increased promptly after a meal and fluctuated markedly during the postprandial period in most studies. By the time migrating motor complex had returned, more than 90% of meal marker (polyethylene glycol) was accounted for in intestinal aspirates. In contrast, only 56%-73% of marker was recovered postprandially in those studies in which the migrating motor complex had not returned by the time the study was terminated. Thus, flow of intestinal content is largely intermittent during fasting, peaks of flow being associated with passage of the activity front of the migrating motor complex; on the other hand, half the fasting flow is unassociated with the activity front. Reappearance of the migrating motor complex at any level after a liquid test meal signals clearing of the liquid meal from the more proximal intestine.

Adult↗