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Biomedical subjects

C Coenen

Publications and source records attributed to C Coenen.

At least 19 recordsLinked to original sources
PubMed1998

The diageotropica gene differentially affects auxin and cytokinin responses throughout development in tomato.

The interactions between the plant hormones auxin and cytokinin throughout plant development are complex, and genetic investigations of the interdependency of auxin and cytokinin signaling have been limited. We have characterized the cytokinin sensitivity of the auxin-resistant diageotropica (dgt) mutant of tomato (Lycopersicon esculentum Mill.) in a range of auxin- and cytokinin-regulated responses. Intact, etiolated dgt seedlings showed cross-resistance to cytokinin with respect to root elongation, but cytokinin effects on hypocotyl growth and ethylene synthesis in these seedlings were not impaired by the dgt mutation. Seven-week-old, green wild-type and dgt plants were also equally sensitive to cytokinin with respect to shoot growth and hypocotyl and internode elongation. The effects of cytokinin and the dgt mutation on these processes appeared additive. In tissue culture organ regeneration from dgt hypocotyl explants showed reduced sensitivity to auxin but normal sensitivity to cytokinin, and the effects of cytokinin and the mutation were again additive. However, although callus induction from dgt hypocotyl explants required auxin and cytokinin, dgt calli did not show the typical concentration-dependent stimulation of growth by either auxin or cytokinin observed in wild-type cells. Cross-resistance of the dgt mutant to cytokinin thus was found to be limited to a small subset of auxin- and cytokinin-regulated growth processes affected by the dgt mutation, indicating that auxin and cytokinin regulate plant growth through both shared and separate signaling pathways.

2,4-Dichlorophenoxyacetic Acid↗
PubMed1997

Auxin-cytokinin interactions in higher plants: old problems and new tools.

The plant hormones auxin and cytokinin interact in a complex manner to control many aspects of growth and differentiation. Recent advances in understanding their metabolism and the cell cycle are now helping to clarify the mechanisms by which these hormones act together to control various physiological and developmental responses. Molecular and genetic tools are being used to reveal interactions between auxin and cytokinin at multiple levels, including mutual regulation of active hormone availability, input into multiple signal transduction pathways, alteration of gene expression, post-translational modifications and direct modulation of enzyme activity.

Cell Cycle↗
PubMed1993

[Severe backache in clinically inactive ulcerative colitis].

A 22-year-old man with a history of ulcerative colitis complained of progressive lower back pain that had persisted for more than one year and which finally confined him to bed. X-ray examination revealed sclerosis of the right sacroiliac joint, and of the 6th lumbar vertebra. An NMR examination revealed a diffuse signal loss in the region of the 6th lumbar vertebra. On account of the progressive increase in liver transaminases in the serum, an ERCP was carried out, which confirmed the suspected primary sclerosing cholangitis (PSC). Severe axial arthritis and PSC with underlying clinically inactive ulcerative colitis was diagnosed, and treatment with salazosulfapyridine and ursodeoxycholic acid initiated. This led to freedom from pain within a matter of weeks and an appreciable reduction in serum cholestasis parameters.

Adult↗
PubMed1992

[Cholecystectomy and colorectal cancer. Does cholecystectomy increase the risk of developing colon cancer?].

PROBLEM: Within the course of the last ten years, a possible association between carcinoma of the colon and prior cholecystectomy has been discussed. METHODOLOGY: In 342 patients with colorectal carcinoma, and in a control group of 182 patients with gastric carcinoma, the rate of prior cholecystectomy was investigated. RESULTS: The cholecystectomy rate in the case of colon carcinoma patients was 7.9, and thus differed non-significantly from that of the control group (5.5%). At least in our case material, no relationship was found between cholecystectomy and carcinoma of the colon. The results reported in other studies are compared and discussed.

Aged↗
PubMed1992

[Recording of data and immediate interpretation of myoelectric activity of the stomach--electrogastrography].

Unlike other electrophysiological measurements such as electrocardiography (ECG) and electroencephalography (EEG), the cutaneous measurement of the electrical activity of the stomach (electrogastrography, EGG) is not an established clinical diagnostic procedure. To overcome common problems in acquiring very-low-frequency signals in the presence of large and unstable voltages we developed a real time data acquisition and analysis system based on linear-phase digital signal processing instead of analog filtering. FFT's computed on line from highly overlapping time sets are displayed as pseudo-3D or grey-scale graphic plots.

Computer Graphics↗
PubMed1992

Does physical exercise influence bowel transit time in healthy young men?

An examination was performed on 20 healthy men, who had a specific diet, to test the influence of moderate physical activity on bowel transit. During a 3-day pause and a 3-day phase of easy sports activity (jogging), oro-anal transit was measured with the help of radiopaque markers (Hinton method). While the subject was under exertion, the entire weight of stool rose significantly (743 vs. 600 g), whereas we found no significant influence on the oro-anal transit time (39 vs. 48 h) or on stool frequency (1.3 vs. 1.3 per day). Moderate physical activity had no effect on bowel transit time of healthy men under a constant diet. The effect of the so often recommended increase of physical activity on constipation remains to be elucidated.

Adult↗
PubMed1991

[Carcinoembryonic antigen (CEA) in ascites].

The diagnostic value of carcinoembryonic antigen (CEA) was studied prospectively in 18 patients with ascites of malignant and 28 patients with ascites of benign genesis. Both sensitivity and specificity reached 83%. With a prevalence of malignant disease of 38%, the positive and negative predictive values were 75% and 89%, respectively. In contrast to frequent false-positive CEA values in the serum of liver cirrhotics (48.3%), false-positive CEA values in the ascites of the same patients were observed in only 17.3%. It is thus recommended that if CEA determination is to be employed, it should be done in the ascites itself.

Ascites↗
PubMed1991

Gastrointestinal transit of solid-liquid meal in chronic alcoholics.

Gastric emptying, mouth-to-cecum transit, and whole-gut transit of a solid-liquid meal were measured in 46 chronic alcoholics and in 30 control subjects by using scintigraphic techniques, hydrogen breath test, and stool markers. In the alcoholics various parameters such as ethanol consumption, gastrointestinal symptoms, and alcoholic neuropathy were determined and related to gastrointestinal transit times. Although there was no significant overall difference of gastric emptying, abnormally delayed gastric emptying was detected in 23.9% of the alcoholics but no control subject (P less than 0.005). Mouth-to-cecum transit was significantly prolonged in the alcoholics (P less than 0.001) with 14 alcoholics (37.8%) disclosing delayed mouth-to-cecum transit. No significant differences between both groups were detected concerning whole gut transit. In the alcoholics there was a significant correlation of dyspeptic symptoms with delayed gastric emptying (P less than 0.006), and alcoholics with diarrhea had an accelerated mouth-to-cecum transit as compared to those without diarrhea (P less than 0.05). Neither the presence of autonomic or peripheral neuropathy nor the presence of liver cirrhosis or ascites was significantly related to gastrointestinal transit times. However, the daily ethanol ingestion significantly correlated with gastric emptying (P less than 0.005). It is concluded, therefore, that in chronic alcoholics the small intestine and the stomach are most likely to be affected by gastrointestinal transit disorders and that these transit abnormalities are potentially related to toxic damage of gastrointestinal smooth muscle.

Adult↗
PubMed1991

Effects of age and gender on fat-induced gallbladder contraction and gastric emptying of a caloric liquid meal: a sonographic study.

In this study, the gastric emptying of a liquid fatty meal and the consecutive gallbladder contraction were simultaneously measured by ultrasound in four different age- and sex-related groups of normal subjects: group A, 15 women less than 50 yr (premenopausal); group B, 15 women greater than 50 yr (postmenopausal); group C, 15 men less than 50 yr; and group D, 15 men greater than 50 yr. Apart from a significantly delayed gastric emptying in the premenopausal women, no significant differences in the postprandial relative gallbladder emptying rates were observed between the four study groups. Ninety-five percent of all study subjects had a gallbladder volume reduction of more than 50% after a liquid fatty meal. It is therefore concluded, that 1) endogenous or contraceptive female sex hormones may have a delaying effect on gastric emptying of caloric liquids in the premenopausal state, 2) aging or gender do not significantly influence the fat-induced gallbladder contraction in man, and 3) a 50% residual volume of the gallbladder after a fatty meal should be considered as the upper limit of normal gallbladder contractility (95 percentile of a normal collective).

Adult↗
PubMed1990

[Sonographic assessment of gastric emptying. Reliability and validity of the antrum sagittal surface method for fluids].

The reliability and validity of sonographic measurements of gastric emptying employing sagittal antral planimetry were investigated. The intraindividual reproducibility of this procedure was examined in 15 healthy volunteers, who ingested 400 ml of water on two separate study days. Simultaneous studies of gastric emptying by ultrasound and scintigraphy were performed on 17 of 20 patients with suspected gastroparesis (16 diabetics and one patient with disseminated encephalomyelitis), using a caloric liquid test meal (20 g Biloptin-fatty meal in 300 ml water at 37 degrees C, radiolabeled with 0.5 mCi 99mTc-colloid). The expansion of the antral area with increasing amounts of ingested fluid and the emptying times showed a good intraindividual reproducibility from day to day (r = 0.94 vs. r = 0.81). There was a significant correlation between the relative residual volumes calculated by scintigraphy and by ultrasound (r = 0.82). These results imply that the ultrasonic sagittal antral area method is reliable and valid in the assessment of gastric emptying rates in humans.

Adult↗
PubMed1989

[Dermatomyositis as a paraneoplastic syndrome. A case report].

A female patient with dermatomyositis with the typical clinical findings of this disease, corresponding histological muscular changes and neurological findings is described. Since in the further course of the disease, recurrent gastric carcinoma was diagnosed, this case again emphasizes the significance of dermatomyositis as a paraneoplastic syndrome, and the need for tumor screening when dermatomyositis is diagnosed in advanced adulthood.

Aged↗
PubMed1989

[The prognostic relevance of tumor localization in colorectal cancer. A multivariate analysis].

Records of 292 patients with colorectal cancer, operated at St.-Josef-Hospital between 1973 and 1984 were studied using Cox regression model to elucidate the prognostic influence of tumor site. Neither in univariate nor in multivariate analysis any significant independent influence of tumor site on prognosis could be detected. Male sex, older age and more advanced tumor stage were independently associated with poorer prognosis.

Aged↗
PubMed1988

Oral inflammatory changes as an initial manifestation of Crohn's disease antedating abdominal diagnosis. Report of a case.

The case of a 14-year-old boy who had oral ulcers with histologic proof of granulomatous disease nine months before the diagnosis of intestinal Crohn's disease is presented. Additional extraintestinal manifestations of this case were cheilitis, anal fissures, and "metastatic" disease to the umbilicus. The diagnosis was established after the onset of abdominal symptoms. All manifestations responded rapidly to systemic prednisone, sulfasalazine, and metronidazole.

Adolescent↗
PubMed1987

[Rate of complications in acute treatment of stomach ulcer: modification of the incidence by active therapy in placebo-controlled studies].

We evaluated 32 randomized placebo-controlled trials in gastric ulcer patients to determine the ulcer-related complication rate (bleeding, perforation) during short-term therapy. Patients treated with placebo had a significantly greater risk to drop out for ulcer-related complications than patients treated with active drugs (1,2% vs 0%; p less than 0,01), while the number of patients dropping out for other reasons did not differ significantly (8,4% vs 7,3%, p greater than 0,1). Thus, the efficiency of active drug therapy in gastric ulcer episodes is not only reflected by a significantly higher healing rate in 4 to 8 weeks (64,7% vs 41,4%, p less than 0,01) but also by a much lower risk for ulcer-related complications.

Anti-Ulcer Agents↗