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Biomedical subjects

R Jensen

Publications and source records attributed to R Jensen.

At least 145 records · Page 8Linked to original sources
PubMed1990

Nodular mesangial glomerulosclerosis in patients without manifest diabetes mellitus.

Nodular mesangial glomerulosclerosis is considered to be the specific renal lesion of diabetes mellitus, and typical histological lesions in non-diabetic patients have been reported only occasionally. A similar lesion has recently been described in patients suffering from light chain disease. We report on two patients without manifest diabetes and without light chain disease, showing progressive impairment of renal function and typical nodular mesangial glomerulosclerosis.

Adult↗
PubMed1990

Severe non-occlusive ischemic stroke in young heroin addicts.

Two heroin addicts, aged 30 and 35 years, developed severe ischemic stroke shortly after intravenous injection of heroin. Arteriograms, CT-scans, and Technesium-99 scintigrams demonstrated non-occlusive extensive infarctions in the carotid territory. Cerebral blood flow investigation in one showed severe hyperemia of the entire left carotid artery territory, including areas, where infarction did not develop. Stroke was not due to arterial occlusion. It was more likely due to generalized hypoxia combined with decreased perfusion pressure in the carotid territory on one site because of external compression of the carotid artery during the intoxicated comatose state.

Adult↗
PubMed1989

One-step extraction of human erythrocyte lipids allowing rapid determination of fatty acid composition.

A one-step extraction procedure to directly quantify cholesterol, phospholipids, and fatty acids in red blood cell membranes has been developed. The method uses a single solvent, isopropanol, which extracts lipids and allows the rapid formation of isopropylic esters of fatty acids by acid catalysis. The efficiency of this new technique has been confirmed by comparing yields of cholesterol and total and individual phospholipids with yields obtained following conventional extraction procedures. Moreover, in comparison to the formation of methyl esters, we demonstrate that directly obtained isopropylic esters immediately allow the quantitative determination of fatty acids, without involving the hydrolytic degradation of fatty acids and the oxidation of unsaturated fatty acids.

Chloroform↗
PubMed1989

Bacteraemia following orotracheal intubation and oesophageal balloon dilatation.

Asymptomatic bacteraemia following balloon dilatation was assessed in 20 adults with oesophageal stricture. Asymptomatic bacteraemia occurred in 12 of 19 patients. The source of the bacteraemia appeared to be the patients' oropharyngeal flora. The bacteraemia was not of clinical importance in our patients, but might lead to endocarditis in predisposed individuals.

Aged↗
PubMed1989

Squamous carcinoma of the cervix complicating pregnancy: recurrence in episiotomy after vaginal delivery.

A patient developed recurrence of squamous carcinoma of the cervix in the episiotomy scar after vaginal delivery through the involved cervix. At the time of her radical hysterectomy, all margins and nodes were free of tumor, suggesting implantation at delivery as the etiology of the recurrence. Review of the literature revealed three other cases of episiotomy recurrence. All cases were either clinically unsuspected or had negative Papanicolaou tests during pregnancy. Careful surveillance and early therapy appear to give a more favorable prognosis for this unusual type of recurrence.

Adult↗
PubMed1989

Evaluation of histopathologic and physiologic changes in cows having premature births after consuming Ponderosa pine needles.

Premature calving, typified by early expulsion (17 to 43 days) of weak or dead calves and accompanied by retained placentas, was induced in 8 of 9 pregnant cows fed a mixture of Ponderosa pine needles and alfalfa hay. Five control cows of comparable gestation age fed only alfalfa hay maintained normal pregnancies until they were euthanatized at the time the pine needle-treated cows were producing premature calves. Serum specimens from all cows were assayed for progesterone concentration and ovaries and placentomes were examined for histopathologic changes. There were no bacterial, fungal, chlamydial, or viral agents determined to be associated with the premature births. Serum progesterone concentration in the treated cows decreased progressively and were 0.4 to 1.5 ng/ml at the time of premature calving. Histopathologic changes were evident in the placenta and corpora lutea of treated cows only. The number of binucleate trophoblastic giant cells in placentomes was less than normal and the number of necrotic luteal cells in corpora lutea was greater than normal.

Animals↗
PubMed1988

Increase of erythrocyte resistance to hemolysis and modification of membrane lipids induced by hemodialysis.

Mechanical fragility, deformability and lipid composition of erythrocyte membranes were studied in 22 uremic dialysed patients before and after dialysis in comparison to controls. While deformability was not affected by a dialysis session, osmotic and saponin resistances to hemolysis were significantly increased after dialysis (p less than 0.001). The lipid composition of erythrocyte membranes was also altered during dialysis, with a notable increase in cholesterol and a different phospholipid distribution, i.e. phosphatidylcholine and sphingomyelin significantly decreased (p less than 0.001). Likewise, the fatty acid distribution showed large variations with an increase in polyunsaturated fatty acid. The acute effect of dialysis on the membrane lipid composition seems to be linked to erythrocyte alterations. Its significance is discussed in relation to the asymmetric transverse distribution of phospholipids previously described in human erythrocyte.

Adult↗
PubMed1988

[Encephalitis].

Explore the source record for details and available documents.

Encephalitis↗
PubMed1988

Nerve growth factor, not laminin, is the major neurite-promoting component in medium conditioned by mouse L929 fibroblast cells.

In this study the neurite-promoting activity present in conditioned medium (LCM) from mouse fibroblast L929 cells was examined. The biological and biochemical properties of nerve growth factor (NGF) synthesized by L929 cells and released into the LCM were studied. In addition it was established that the extracellular matrix protein laminin is synthesized by L929 cells and is also present in LCM. Although NGF is a well-recognized neurite-promoting factor, recent studies have suggested that laminin is also a neurite-promoting factor. In this paper the possibility that NGF and laminin were both responsible for the neurite-promoting activity of LCM was examined. It was determined that NGF, not laminin, is the major neurite-promoting component in LCM. This was established using pheochromocytoma (PC12) cells as a biological test system and also utilizing antibodies to both NGF and laminin. The possible functional significance of NGF synthesis by fibroblast cells is discussed.

Animals↗
PubMed1988

[Effect of water containing calcium and magnesium sulfates on the elimination of cholesterol in the rat].

In the rat, the activity of the thermal water of Capvern and of its ionic components on the modification of the flow rate and composition of hepatic bile has been investigated. Two groups of rats were selected: the first group received per os an overload of the thermal water during six weeks. At that time on empty stomach a great increase of biliary phospholipids was observed. An intraduodenal injection of the thermal water produced a significant and rapid increase of biliary flow rate and biliary cholesterol. the animals of the second group received through intraduodenal injections the thermal water or an anionic solution composed of calcium, of magnesium sulphate or of both salts at their concentration in the thermal water, respectively. We observed an increase in biliary flow rate and biliary calcium concentration in the rats receiving the solution of calcium sulphate only and an increase of choleresis in the rats receiving the thermal water only. These data suggest that the thermal water has a specific action on the metabolism of cholesterol in increasing its biliary elimination particularly through the calcium ion content of the water.

Animals↗
PubMed1988

Association of bovine respiratory syncytial virus with atypical interstitial pneumonia in feedlot cattle.

Thirty-three cattle with fatal respiratory tract disease were examined for gross and histologic lesions and for the presence of viral and bacterial agents in the lungs. Fifteen cattle had lesions characteristic of atypical interstitial pneumonia (AIP), and 18 had other respiratory tract diseases, including infectious bovine rhinotracheitis, shipping fever pneumonia, bronchopneumonia, pulmonary abscess, and edema of the trachea. Gross necropsy findings in the cattle with AIP were uncollapsed and emphysematous lungs; histopathologic findings included interstitial edema, thickening of alveolar walls, hyaline membrane formation, and hyperplasia of type-II pneumonocytes. The infective agents found in the lungs of the 33 cattle included bovine respiratory syncytial virus, bovine herpesvirus type 1, Pasteurella sp, mycoplasmas, and Corynebacterium pyogenes. Bovine respiratory syncytial virus was detected by use of immunofluorescence and immunoperoxidase on lung tissue sections; bovine herpesvirus type 1 was detected by these techniques and by isolation of the virus. Bovine respiratory syncytial virus was significantly (P = 0.01) associated with lesions of AIP (11 of 15), compared with those of other respiratory tract diseases (5 of 18).

Animals↗
PubMed1988

Value of a spectroscopic "fecalogram" in determining the etiology of steatorrhea.

We have developed a "fecalogram" to present the analytical results for four characteristics of fecal specimens: dry weight, total nitrogen, total fat, and hydrolyzed fat, measured by near-infrared spectroscopy. This technique gives results as precise as those of more traditional analyses for these four components. The respective correlation coefficients are 0.973, 0.960, 0.974, and 0.978. The CVs for this technique range from 1.19% to 2.88%. Among the digestive disorders revealed by this fecalogram is steatorrhea, which can be differentiated as being of pancreatic or intestinal etiology. The percentage of total fat that is hydrolyzed is significantly (P less than 0.0001) greater in patients with malabsorption (greater than 70%) than in those with maldigestion (less than 70%).

Celiac Disease↗
PubMed1988

Brain and optic system pathology in hypocholesterolemic dogs treated with a competitive inhibitor of 3-hydroxy-3-methylglutaryl coenzyme A reductase.

The cholesterol lowering compound lovastatin, a competitive inhibitor of 3-hydroxy-3-methylglutaryl coenzyme A reductase (EC 1.1.1.34 HMG CoA reductase), was given in nine separate experiments to normocholesterolemic dogs at rates up to 180 times the maximum therapeutic dose in man (1 mg/kg/day). Mean serum total cholesterol concentrations were reduced as much as 88% below normal. Clinical evidence of neurotoxicity occurred in up to 37% of animals given 180 mg/kg/day lovastatin for 11 or more days, especially in one laboratory where the dosing regime resulted in higher concentrations of plasma drug levels. Dogs receiving 60 mg/kg/day or less never exhibited neurologic signs. The central nervous system (CNS) of affected dogs exhibited endothelial degeneration and hemorrhagic encephalopathy. Focal extravasation of horseradish peroxidase occurred frequently (6/8) in the retrolaminar optic nerve of asymptomatic or clinically affected dogs given 180 mg/kg/day lovastatin, with endothelial degeneration and discrete optic nerve degenerative lesions interpreted as ischemic. The association between the degree of hypocholesterolemia and occurrence of clinical signs was not exact. Total brain cholesterol was similar in treated and control dogs. Hypocholesterolemic dogs had proportionally lowered serum concentrations of alpha-tocopherol, but oral supplementation of this vitamin did not prevent the neurologic syndrome. Endothelial degeneration in the CNS and optic nerve may have reflected in vitro morphologic effects of HMG CoA reductase inhibitors due to extreme inhibition of nonsterol isoprene synthesis. Retinogeniculate axonal (Wallerian-like) degeneration occurred in greater than or equal to 12% of dogs given 60 mg/kg/day or more lovastatin, with central chromatolysis of occasional retinal ganglion cells. These neuroaxonal changes may have been secondary to vascular effects, but superimposed direct neurotoxic action at the high dosage levels of lovastatin could not be excluded. There was no evidence of drug induced adverse effects in the CNS of dogs given up to 30 mg/kg/day lovastatin for 2 years.

Animals↗
PubMed1987

Relationship between fecal neutral steroid concentrations and malignancy in colon cells.

Analysis of total and individual fecal neutral steroids in different groups of intestinal pathology from 105 patients was performed to investigate a relationship between neutral steroid concentration and malignant potentiality of colon cells. The fecal concentration of total neutral steroids was significantly higher in patients with colon cancer (57.3 +/- 2.4 mmol/kg of wet feces) and patients with malignant degenerative polyps at Stage I or II (49.5 +/- 2.9) compared with controls (36.9 +/- 3.5) as well as patients with adenomatous polyps (22.4 +/- 2.0). Moreover, a significant correlation was found between total neutral steroid concentrations and coprostanol concentrations in patients with colon cancer (r = 0.928) and in patients with malignant polyps (r = 0.915). Coprostanol results only from the biohydrogenation of delta 5-3 beta-OH steroids by anerobic bacteria because the analysis of a malignant colon tumor in comparison with a healthy colon wall showed that cholesterol is the only steroid included in membrane cells, and that the incubation of Clostridium or Bacteroides with delta 5-3 beta-OH steroids, such as cholesterol (steroid of animal origin) or beta-sitosterol (steroid of plant origin) converts these steroids into coprostanol at a level of efficiency greater than 45%. The findings suggest that high levels of coprostanol reflecting a high growth of anerobic bacteria through the gut are related to the malignant potentiality of colon cells. The screening of neutral fecal steroids should provide a valuable parameter for predicting the malignancy of colon cells.

Bacteria, Anaerobic↗