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Biomedical subjects

J L Larsen

Publications and source records attributed to J L Larsen.

At least 145 records · Page 8Linked to original sources
PubMed1985

Unusual cause of short stature.

A 24-year-old man evaluated for paresthesias and short stature was found to be hypocalcemic on initial presentation. Further evaluation showed that he had a low-normal parathormone level by amino-terminal assay, medullary stenosis of the long bones, and multiple ophthalmologic abnormalities. The remainder of his pituitary function, including growth hormone response to insulin-induced hypoglycemia, was normal. As no family history of similar findings was evident, a sporadic case of Kenny's or Kenny-Caffey syndrome was diagnosed. He became normocalcemic in response to vitamin D and calcium carbonate therapy. The results of testing in this patient and the findings in other patients previously described with the Kenny-Caffey syndrome are reviewed.

Adult↗
PubMed1985

The posterior surface of the lumbar vertebral bodies. Part 2: An anatomic investigation concerning the curvatures in the horizontal plane.

The horizontal curvatures of the posterior surfaces of the lumbar vertebral bodies have been quantitatively evaluated by means of a simple measuring device. The measurements have been done near the superior and inferior vertebral margins. The aims of the study were: to obtain exact information on the degrees of curvatures and their interindividual variations and further compare the information obtained with current knowledge of the relevant embryologic and mechanical factors involved to explain the curvatures and to use the results as a basis for a theory on the development of some of the forms of lumbar canal stenosis. A horizontal concavity was always found in L1-L3, in L5 a posterior convexity was prevailing, and L4 occupied an intermediate position. The degree of medullary ascent and its relationship in time to vertebral development are probably important and are, together with the three first mentioned factors discussed, determinants in the evolution of lumbar canal stenosis. The results are discussed in light of a possible influence on moulding of the vertebrae caused by the contents of the spinal canal and the vertical load of the body weight.

Cadaver↗
PubMed1984

Vibrio anguillarum: influence of temperature, pH, NaCl concentration and incubation time on growth.

An analysis of the effect of growth conditions on the growth (O.D. values) of five Vibrio anguillarum strains showed that the optima were as follows: pH 7, temperature 25 degrees C, NaCl concentration 2%, and O.D. estimates increased with the incubation time. The independent parameters, as well as their interactions significantly influenced the growth of Vibrio anguillarum (P less than 0.0001). Only the strain-salinity interaction was not always statistically significant. A restriction of the parameters to a level relevant for Danish marine recipients showed that pH and NaCl concentration (salinity) might be of minor importance while the temperature was always of high significance. The possible impact of these observations on local conditions is discussed.

Hydrogen-Ion Concentration↗
PubMed1984

Agglutination Typing of Vibrio anguillarum Isolates from Diseased Fish and from the Environment.

Agglutinating activity was widely distributed among 101 Vibrio anguillarum strains of different origin and three Vibrio ordalii strains from salmonids. The spectrum of cells which were agglutinated comprised yeast cells and human (type O), poultry, guinea pig, and trout erythrocytes, whereas ovine, bovine, and tanned bovine erythrocytes were not affected. Mannose-sensitive hemagglutination, mannose-resistant hemagglutination, and non-agglutinating strains were recognized. The three V. ordalii strains showed mannose-resistant hemagglutination, whereas V. anguillarum exhibited either mannose-sensitive hemagglutination or was non-agglutinating. Among V. anguillarum, sensitivity to d-galactose and l-fucose occurred sporadically. An agglutination typing scheme was developed for strains of V. anguillarum based on the agglutination pattern of human, poultry, guinea pig, and trout erythrocytes and yeast cells. Eight different agglutination types (A through H) were defined. The distribution of these types among fish pathogenic and environmental V. anguillarum strains were studied. The application of the typing scheme in ecological and epidemiological studies and for preventive medical purposes is discussed.

Journal Article↗
PubMed1984

Cerebral schistosomiasis presenting as a brain tumor.

A patient with cerebral Schistosoma mansoni schistosomiasis is described. The infection presented as a cerebral tumor, and the patient did not have the usual hepatic or intestinal symptoms of this disease. The computed tomography (CT) findings in histologically proven cerebral schistosomiasis are reported. The pathological CT findings developed at a late stage of the disease, and the CT scans were normal at a time when the EEG recordings were pathological.

Adult↗
PubMed1984

In vitro studies of prolactin inhibition of luteinizing hormone action on Leydig cells of rats and mice.

Previous in vivo studies have shown that in male rabbits prolactin inhibits the testosterone production stimulated by luteinizing hormone (LH) or human chorionic gonadotropin (hCG). This inhibition has now been studied in vitro using both mouse and rat testicular interstitial cells. First, the dose response of human LH (hLH) stimulation of testosterone was studied in detail using testicular interstitial cells from both species. Next, a small but stimulatory dose of hLH was selected and extensive prolactin doses were studied in vitro. NIH B-6 (bovine) prolactin in varying doses was added to the interstitial cells 30 min prior to the addition of a constant dose of hLH. Under these circumstances prolactin inhibited LH action over a wide range of doses. In both species a biphasic dose-response curve existed: large doses of 100 to 1000 ng/ml produced less inhibition or augmented LH action, compared to smaller doses. Next, entire hLH dose-response curves were produced in the presence of three doses of prolactin (0.33, 33, and 1000 ng/ml) as well as in the absence of prolactin. The addition of prolactin shifted the hLH dose-response curve to the right and depressed the maximal response in comparison to the curve without prolactin. Finally, inhibitory doses of prolactin resulted in no detectable change in LH receptor number as estimated from Scatchard plots. It is concluded that prolactin inhibits LH action on interstitial cells as determined by rate of testosterone production except at very large doses of prolactin where LH action is less inhibited or augmented. The inhibitory action of prolactin in this in vitro interstitial cell assay was not accompanied by a decrease in LH receptor number. Thus, a postreceptor action is likely to be involved.

Animals↗
PubMed1984

The impact of terrestrial and estuarial factors on the density of environmental bacterial (Vibrionaceae) and faecal coliforms in coastal water.

A study of the densities of faecal coliforms, Vibrio anguillarum, Vibrio alginolyticus and Aeromonas hydrophila in Danish bathing areas was carried out over the period May-October, 1981 with special reference to specific terrestrial and estuarial determinants. Significant correlations were found between V. anguillarum and V. alginolyticus (r = 0.57) and A. hydrophila and faecal coliforms (r = 0.43). The densities of the Vibrios were highly influenced by temperature and distance from pollution source, while salinity was of minor importance. R2 values for V. anguillarum, V. alginolyticus and A. hydrophila of 0.54, 0.51 and 0.40, respectively, indicate that these organisms were superior to faecal coliforms (R2 = 0.21) in characterizing the local conditions. The following levels were used as relevant to characterize an environmental risk: faecal coliforms 1000/100 ml, V. anguillarum 10000/100 ml, V. alginolyticus 500/100 ml and A. hydrophila 500/100 ml. It was found that the position of sampling site, discharge with the current, and uncontrolled outlets influence the frequency of violations. At certain sites coincidence of violations for both faecal and environmental bacteria indicated a simultaneous existence of a faecal and "organic" pollution. At other sampling sites high levels of environmental bacteria only should be considered important to the evaluation of the hygienic quality of the water.

Aeromonas↗
PubMed1983

Congenital thymic cysts in the neck.

Cervical thymic cysts are rare. Sixty-seven cases are reported in the literature up until 1982. Remnants of thymic tissue in the course of descent may lead to cystic development. The majority of the cases is found in males under 10 years of age, typically on the left side of the neck. The characteristic histological features are thymic tissue with Hassall's corpuscles and cholesterol clefts found in the cyst wall. A preoperative correct diagnosis has never been made. Typically, the templative diagnosis has been a common branchial cyst. An additional case of a thymic cyst is reported, here. Surgical removal was complicated by lesion of the vagal nerve, which has never been described, although the cysts are often adherent to the carotid sheath and vagal nerve.

Child↗
PubMed1983

The effect of antibiotics on mannose-resistant haemagglutination by K88- and K99-positive Escherichia coli strains.

Five E. coli strains carrying K99 antigen isolated from the intestines of calves which had succumbed to diarrhoea and six K88-positive strains isolated from fatal cases of diarrhoea in piglets were examined for their mannose-resistant haemagglutination (MRHA) capacity against pig erythrocytes. The bovine strains showed a geometric mean MRHA-titre of 1/18 and the porcine strains one of 1/45. Similar experiments were carried out after addition of the following antibiotics in doubling dilutions: ampicillin, chloramphenicol, colistin, dihydrostreptomycin, gentamicin, neomycin, polymyxin B and oxytetracycline. Colistin and polymyxin B had a marked concentration-dependent inhibitory effect on MRHA. Neomycin and gentamicin also inhibited MRHA but to a lesser degree. Chloramphenicol, dihydrostreptomycin and oxytetracycline showed no effect. With ampicillin, a trend was found for the ratio values to be inversely proportional to the concentration. This suggests that this antibiotic has an enhancing effect on the haemagglutination.

Animals↗
PubMed1983

Metrizamide myelography: blood and cerebrospinal fluid response.

Cerebrospinal fluid and blood were examined for immunologic factors before and after metrizamide myelography in 13 patients who underwent lumbar myelography and seven patients who underwent thoracic myelography. Clinical symptoms were also recorded. The results were consistent with a toxic reaction to the contrast medium, rather than an immunologic one.

Adolescent↗
PubMed1983

Colistin inhibition of mannose-resistant haemagglutination by K88-positive and K99-positive escherichia coli strains. A preliminary report.

Two enteropathogenic E. coli strains isolated from a calf and a piglet succumbed to diarrhoea were studied. The bovine strain carried K99-antigen and the porcine strain was K88-positive. Both strains agglutinated pig erythrocytes in the presence of D-mannose. In the test a bacterial cell density of 3 x 10(9) per ml and doubling dilutions hereof were used. The haemagglutination titres were 16 and 128, respectively. When the bacteria were exposed to colistin before mixing with the red cells, haemagglutination was inhibited completely with 1.0 and 0.5 microgram/mg of colistin. At a colistin concentration of 0.25 microgram/ml (1/4-1/2 of the MIC's) the titres were lowered by a factor of 16-32.

Animals↗
PubMed1981

A comprehensive study of environmental and human pathogenic Vibrio alginolyticus strains.

An investigation comprising 49 environmental (VAE), 7 human isolates (VAH) and 3 type culture (VAT) strains of Vibrio alginolyticus showed a very high similarity among the strains. By primary isolation a swarming activity on blood agar and a yellow, hemispheric relatively large colony type on TCBS were very conspicuous. Besides the characteristics of Vibrionaceae the most typical and differential diagnostic important features were: sucrose fermentation, lysine decarboxylase activity, acetoine and 2,3 butanediol production, no growth on an electrolyte deficient medium (CLED), arginine and arabinose negative reaction. Swarming on blood agar and growth in 10% NaCl were also important although one of these criteria might be negative. An obvious difference was observed in ornithine where the percentage of positive VAE, VAH and VAT were 51, 100 and 0, respectively. In cellobiose all VAE and VAT but only two VAH were positive. MR positive strains were also found among all categories. The G + C mol% in the strains ranged from 45.9 - 46.8.

Amino Acids↗
PubMed1981

Occurrence of Vibrio parahaemolyticus and Vibrio alginolyticus in marine and estuarine bathing areas in Danish coast.

From seventeen sites in three marine and two estuarine bathing areas at the Danish coast water samples were collected during the period from May to November 1979. Total bacterial counts were performed on blood agar. The prevalence of Vibrio parahaemolyticus and Vibrio alginolyticus in 100 ml water samples using the filter membrane technique and TCBS agar plates was investigated with the possible correlation to water temperature and salinity. Only five strains of V. parahaemolyticus were isolated, two from marine and three from estuarine water. V. alginolyticus was isolated in 8.33 and 15.63 per cent, in relation to the total bacterial count/100 ml on TCBS agar, in marine and estuarine water samples, respectively. The maximum was registered in June and July, corresponding with the highest temperatures recorded (12-18 degrees C). V. alginolyticus should be considered a widely distributed bacterium in Danish coastal areas and could be regarded as a bacterial indicator of hygienic and public health importance.

Bathing Beaches↗