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Biomedical subjects

P Jansen

Publications and source records attributed to P Jansen.

At least 37 records · Page 2Linked to original sources
PubMed1996

Clinical outcome after coronary surgery with heparin-coated extracorporeal circuits for cardiopulmonary bypass.

In this prospective randomized trial, we studied whether heparin-coated extracorporeal circuits (ECC), known to reduce complement activation, could improve the clinical outcome of 200 patients undergoing coronary artery surgery. Patients have been divided into two groups (heparin-coated ECC and uncoated ECC groups) which were similar in terms of age, gender, left ventricle function, preoperative aspirin use and consequent intraoperative aprotinin use, number of grafts, duration of aortic cross-clamping and cardiopulmonary bypass. Univariate analysis showed that heparin coating did not reduce significantly postoperative bleeding (640 +/- 311 versus 682 +/- 342 ml with uncoated ECC) nor the need for transfusion (19% of patients versus 25% with uncoated ECC). Adverse events, including all mortality and morbidity noticed during the five first postoperative days, occurred in 20 patients of the uncoated ECC group and in eight patients of the heparin-coated ECC group (p = 0.013). The most frequent complications were supraventricular arrhythmias that occurred in 13 patients of the uncoated ECC group and in four patients of the heparin-coated ECC group (p = 0.02). Multivariate analysis by stepwise logistic regression showed that only heparin coating of the ECC was shown as a significant predictive factor of adverse events reduction (p = 0.01; odds ratio = 0.34). These data suggest that heparin coating reduced postoperative complications in patients undergoing coronary artery surgery.

Aged↗
PubMed1995

Endosonography of gastroesophageal varices: evaluation and follow-up of 76 cases.

Endosonography was performed in 76 patients who had endoscopically detected gastroesophageal varices or questionable submucosal lesions, or who were being evaluated for pancreatic carcinoma or pancreatitis. The result were compared with surgery or autopsy results. The patients were divided retrospectively into four groups. Group 1 consisted of 6 patients who underwent surgery or autopsy. Five esophageal varices and 1 fundic varix were diagnosed with endosonography and confirmed histologically. Group 2 consisted of 29 patients undergoing sclerotherapy. Intramural thickening of the esophagus and extramural collaterals were found in 20 of 22 patients, respectively. Endoscopy revealed fibrosis in 10 patients. Group 3 consisted of 16 patients evaluated for pancreatic disease. Fifteen fundic varices, 6 cardiac varices, and 5 extramural collateral veins were found by EUS. Group 4 consisted of 16 patients with questionable submucosal lesions and 9 patients with lesions recognized endoscopically as varices. EUS found varices in all 25 patients. In conclusion, EUS is an important procedure in the diagnosis and follow-up of gastroesophageal varices, and in the identification of questionable abnormalities found endoscopically. The effect of sclerotherapy can be demonstrated as mural thickening with disappearance of submucosal varices.

Case-Control Studies↗
PubMed1993

The influence of image resolution on the positron emission tomographic measurement of caudate glucose consumption.

The aim of this study was to investigate the influence of image resolution on (a) relative and absolute values of caudate glucose consumption (rCMRGlc) determined by positron emission tomography (PET), and (b) the detection of significant differences in these metabolic values between groups of subjects. For this purpose, raw data of cerebral accumulation of fluorine-18 fluorodeoxyglucose (FDG) obtained in 11 normal subjects and in nine patients with unilateral thalamic infarction were reconstructed using filtered backprojection with four different cut-off frequencies (CFs), yielding images with a transaxial resolution of 5.7, 7.1, 8.9 and 11 mm (full-width at half-maximum; FWHM). Absolute values of caudate rCMRGlc decreased significantly by more than 30% over the range of image resolutions studied. Bilateral ratios of caudate rCMRGlc were insensitive to variations in image resolution. Levels of significance assessing the differences in mean metabolic values between patients and controls were all below 0.01. They were, however, slightly better at image resolutions of 7.1 and 8.9 mm than at a resolution of 5.7 mm. These data indicate (a) that relative values of rCMRGlc are better suited to compare quantitative results from different PET cameras than are absolute values, and (b) that the CF used for the filtered back-projection exerts a small but not negligible influence on levels of significance assessing differences in metabolic values between groups of subjects.

Adult↗
PubMed1993

Fetal antigen 1 (FA1) in the human pancreas: cell type expression, topological and quantitative variations during development.

Monospecific rabbit anti-human fetal antigen 1 (FA1), was used to examine the distribution of FA1 during the development of the human fetal pancreas and liver using an indirect immunoperoxidase technique. FA1 was expressed by 94% of the glandular epithelial cells of the branching ducts in the pancreatic anlage at week 7 of gestation. This pattern changed during the development of the human pancreas, 64% of the glandular cells being FA1 positive at week 17 of gestation, decreasing to 11% in the infant (4 months after birth). In the infant and adults the FA1 expression was restricted to a subpopulation of beta-cells within the islets of Langerhans. Insulin immunoreactive cells were scattered throughout the epithelium of primitive branching pancreatic ducts at week 7 of gestation, well before the formation of islets. From the 7th through to the 17th week of gestation, FA1 was found in the cytoplasm of fetal hepatocytes, whereas no staining was observed in the liver from a 4-month-old infant. No FA1 expression was found in the epithelium of the developing gut. The present findings indicate that the glandular epithelial cells in the developing pancreas may serve as stem cells, which, if appropriately induced, may differentiate into endocrine cells. Fetal antigen 1 (FA1) may take part in or be a result of this differentiation.

Adult↗
PubMed1992

Defective biliary excretion of epinephrine metabolites in mutant (TR-) rats: relation to the pathogenesis of black liver in the Dubin-Johnson syndrome and Corriedale sheep with an analogous excretory defect.

Dubin-Johnson patients, mutant Corriedale sheep and TR- and EHBR mutant rats have recessively inherited defective bile canalicular secretion of many nonbile acid organic anions. The human and ovine mutants have black livers and lysosomal pigment accumulation. The livers in TR- and EHBR mutant rats are not black, and sparse lysosomal pigment accumulation is seen. Previously, we postulated that the unidentified pigment in the Dubin-Johnson syndrome results from the accumulation of tyrosine, phenylalanine and tryptophan metabolites, such as metanephrine, which are normally secreted in bile as organic anions. We tested this hypothesis in TR- rats. 3H-epinephrine was injected intravenously; control rats secreted 2.80% +/- 0.52% of the injected dose in bile as compared with 0.19% +/- 0.07% in TR- rats. From 82% to 90% of biliary radioactivity was due to polar conjugates in control rats and mutant rats. TR- rats retained more of the injected dose in the liver, particularly in lysosomes, and secreted more in urine than did control rats. After feeding control and TR- rats for 4 mo with a rat chow diet supplemented with 4% tyrosine, tryptophan and phenylalanine, the liver did not become grossly black; however, histological and electron microscopic study revealed dense lysosomal pigment accumulation in TR- rats. Intraportal injection of metanephrine resulted in the appearance of black liver in TR- rats that persisted for at least 2 hr and was not associated with pigment accumulation by light or electron microscopic examination.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1992

Glue sniffing: a comparison study of sniffers and non-sniffers.

A study of 22 glue sniffers and 22 non-sniffers was carried out with individuals from the same reference group. The subjects were all street children living in supervised shelters. No statistically significant differences were found between the sniffers and non-sniffers on cognitive measures or biographical features (e.g. time spent at school, years on the street). When rated by shelter staff on a modified version of the Christiansen Rating Scale (1967) the sniffers were perceived to be significantly more disturbed in their relationships with others, however, methodological issues do not permit conclusive evidence of behavioural differences to be drawn. The authors conclude that the findings lend support for the view that the effects of volatile substance abuse on cognitive and personality functioning cannot be clearly demonstrated.

Adolescent↗
PubMed1990

Electro-encephalographic disturbances due to chronic toxin abuse in young people, with special reference to glue-sniffing.

A study was carried out in order to document any abnormalities in the electro-encephalogram (EEG) that might appear in young adolescents who have deliberately inhaled the range of volatile substances loosely referred to as 'glue'. The EEGs of a group of 'street children' being assisted in a Johannesburg shelter were examined. The records were analysed for any clinical abnormalities and also subjected to spectral analysis in order to examine the overall characteristics of frequency, power and spatial distribution. The EEGs clearly revealed that, although at the time of the examination the subjects were ostensibly abstinent, both clinical and normative evidence of continuing brain disturbance was present. It was concluded that glue sniffing is likely to have long term electrocerebral sequelae.

Adolescent↗
PubMed1990

Defective ATP-dependent bile canalicular transport of organic anions in mutant (TR-) rats with conjugated hyperbilirubinemia.

TR- mutant Wistar rats secrete markedly fewer organic anions other than bile acids from the liver into the bile than do control rats. Fluorescence-image analysis of isolated normal and TR- hepatocyte "doublets", which retain a bile canaliculus between them, revealed that normal hepatocytes readily transport a fluorescent bile acid (fluorescein isothiocyanate glycocholate) and a nonbile acid organic anion (carboxydichlorofluorescein diacetate) into the canaliculus. Hepatocyte doublets from TR- rats also transported fluorescein isothiocyanate glycocholate normally, but transport of carboxydichlorofluorescein diacetate into the canaliculus was negligible. Vesicles derived from the canicular domain of the plasma membrane of hepatocytes (CMV) from control and TR- rats were used to characterize the transport process for 35S-labeled bromosulphthalein and 35S-labeled bromosulphthalein glutathione, which represent nonbile acid organic anions. CMV from normal rat hepatocytes had an ATP- and temperature-dependent, saturable transport process for these 35S-labeled compounds that was absent in CMV from TR- rats. CMV from TR- rats retained normal ATP-dependent transport of daunomycin, and immunologic blots with a monoclonal antibody against the multidrug resistance gene product, P-glycoprotein, revealed no difference between normal and TR-CMV. These studies reveal that the bile canaliculus in normal rats contains an ATP-dependent organic anion transport system that is functionally absent in TR- mutant rats. The defect in TR- mutant rats is phenotypically similar to that seen in mutant Corriedale sheep and in the Dubin-Johnson syndrome in man.

Adenosine Triphosphate↗
PubMed1989

Interleukin-6 and interleukin-1 production in acute leukemia with monocytoid differentiation.

Several authors have reported the in vitro production of colony-stimulating factors (CSF) and interleukin-1 (IL-1) by the neoplastic cells from patients with acute myeloid leukemia (AML). Using a sensitive bioassay for IL-6, the capacity of the leukemic cells of 30 patients with AML to produce IL-6 was examined. IL-6 production was found to be specific for cells from patients with an AML with monocytic differentiation (12 of 15 M4 and M5 patients, 0 of 15 M1 and M2 patients). Moreover, IL-6 production was paralleled by IL-1 production. The IL-6- and IL-1-producing cells were mainly found in the more mature monocytic cell fractions, defined as CD14-positive and CD34-negative adherent cells. By limiting dilution experiments, it could be excluded that the production of IL-1 or IL-6 was due to contamination with normal monocytes.

Antigens, CD34↗
PubMed1985

The treatment of senile dementia associated with cerebrovascular insufficiency: a comparative study of buflomedil and dihydrogenated ergot alkaloids.

Seventy-six patients took part in a randomized, comparative study of the efficacy of buflomedil hydrochloride and dihydrogenated ergot alkaloids in the treatment of senile dementia associated with cerebrovascular insufficiency. Efficacy was assessed by the patients' performance in four psychometric tests. The results showed that a trend in favour of the buflomedil group in three of the tests became statistically significant in the fourth. Both drugs appeared to be safe, causing no marked adverse reactions. In conclusion, buflomedil is as effective or more effective than dihydrogenated ergot alkaloids in the treatment of senile dementia associated with cerebrovascular insufficiency and could prove a valuable addition to long-term therapy if further studies support the trend shown in this study.

Aged↗
PubMed1978

[Concentration of specific antibodies in commercially avaialable immunoglobulins (author's transl)].

Not significant differences in the composition or concentration of specific antibodies against microbial antigens could be measured in five commercially available human immunoglobulin preparations for intravenous use. Prediction of prophylactic or therapeutic efficiency of such preparations according to their antibody content seems to be only partially possible. Human immunoglobulins for intravenous use should be free from irregular antibodies against erythrocyte antigens of the Rh-systems, as found in one of the specimens tested.

Antibodies↗
PubMed1978

[Studies of the ph dependency of the rubella HAI test (author's transl)].

To establish a possible dependency of the rubella hemagglutination inhibition (HAI) test upon the pH value, 4 pooled sera were examined for their content of rubella-specific antibody in the HAI test at varying pH (6.0;6.5;7.0;7.5;8.0). The results obtained for the range of pH 6.0--8.0 speak against a pH dependency of the rubella HAI test.

Antibodies, Viral↗
PubMed1978

[Visualization by electronmicroscopy of 28 nm virusparticles (astroviruses) in faeces of newborns with acute nonbacterial gastroenteritis (author's transl)].

On occasion of an epidemic of acute nonbacterial gastroenteritis virus particles were visualized by electronmicroscopy in the faeces of 76 newborns; these particles had the following properties: mean diameter 28 nm; ether-resistent, stable at pH 3.0; buoyant density 1.33--1.34 g/ml in CsCl. About 10% of these particles had a definite star-like structure on their surface. Due to these properties the virusparticles were considered to be astroviruses. The virus was not cytopathogenic for cell cultures susceptible for enteroviruses, and not pathogenic for newborn mice.

Cytopathogenic Effect, Viral↗
PubMed1977

[Acute hemorrhagic meningoencephalitis due to rubella-infection in acute lymphatic leukemia (author's transl)].

We observed a fatal meningoencephalitis in a patient who suffered from acute lymphatic leukemia. The infection occurred after complete bone marrow remission. As the cause of this complication we discovered a rubella-infection, whose beginning had been several weeks ago. Relations to several forms of rubella-encephalitis in otherwise healthy patients are discussed and pathogenetical conclusions are made.

Acute Disease↗