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Biomedical subjects

J L Larsen

Publications and source records attributed to J L Larsen.

At least 199 records · Page 11Linked to original sources
PubMedDate not supplied

[Clinical and neuroradiological findings in gliomatosis of the brain with special reference to magnetic resonance tomography].

We present three cases of GC, one belonging to the brainstem, and two belonging to the hemisphere type. Two cases were investigated by MRI. Tumour infiltration, while yielding only vague CT findings, was well demonstrated in MR studies where extensive hyperintense lesions were found in T2- and proton density images. In patients studied by MR these were localized within the white matter and corpus callosum. No enhancement was seen after administration of Gd- DTPA. These findings may strongly indicate the presence of gliomatosis cerebri, when clinical and laboratory data exclude inflammatory or neurodegenerative disease. Despite the good delineation of white matter changes stereotactic biopsy remains necessary to confirm the diagnosis of gliomatosis cerebri pathohistologically.

Adolescent↗
PubMedDate not supplied

The posterior surface of the lumbar vertebral bodies. Part I.

The degree of concavity (ie, the scalloping) on the posterior surface of the lumbar vertebral bodies has been evaluated quantitatively by means of a simple measuring device. The scalloping in the median sagittal plane was found to differ from that in the lateral plane, near the pedicular attachments. In the medial plane, an increase in scalloping from L1-L4 was noted, with a subsequent decrease at L5. Laterally, the concavity deepened from L1-L5, the values here being larger than those medially at all levels. The results are discussed with respect to the anatomy of the dural sac and its contents, and the spinal nerves. Scalloping in the lateral sagittal plane is, especially at the fourth and the fifth lumbar levels, presumed to be caused mainly by pressure exerted by the spinal nerves. The medial scalloping is presumed to be partially due to hydrostatic pressure of the cerebrospinal fluid in the dural sac. This pressure will, at the edges of the superior and inferior end-plates, be counteracted by the tractional stresses of the fibers of the discal annulus fibrosus that are inserted at the vertebral margins. This effect contributes to the final shape of the vertebral bodies. The posterior vertebral surface constitutes part of the anterior wall of spinal canal. Therefore its shape has relevance in cases of spinal stenosis, and some aspects of this relationship are discussed.

Adult↗
PubMedDate not supplied

Idiopathic hypothalamic dysfunction with precocious puberty and adipsic hypernatremia first presenting in adolescence.

BACKGROUND: Idiopathic hypothalamic dysfunction is a rare syndrome that has been described in young children. This syndrome is characterized by a disturbance of thirst regulation with hypernatremia, hyperosmolarity, and altered hypothalamic function. PATIENT REPORT: At age 6 years the reported patients presented with precocious puberty, by age 12 years she had hypernatremia presumed secondary to central diabetes insipidus and was treated with DDAVP, and at age 14 was identified to have hyperprolactinemia. At age 19 she presented with serum sodium of 185 mg/dl during an episode of illness associated with dehydration. After hydration, her sodium remained elevated. Arginine vasopressin was measurable but inappropriate to serum sodium, while urinary cyclic AMP response to vasopressin was appropriate. CONCLUSIONS: This is the first case of precocious puberty identified in association with the more classic features of idiopathic hypothalamic dysfunction, including later-onset hypernatremia, poor thermoregulatory function, obesity, and hyperprolactinemia.

Arginine Vasopressin↗
PubMedDate not supplied

Determination of insulin requirements: excessive insulin dosages common in type 1 diabetes mellitus.

OBJECTIVE: To report our experience of determining insulin requirements for initiating continuous subcutaneous insulin infusion (CSII) pump therapy, using an algorithm for intravenous administration of insulin, in patients with poorly controlled diabetes. METHODS: We describe assessment of insulin requirements and analyze data from 27 consecutive admissions. All patients had type 1 diabetes mellitus and were being converted to CSII pump therapy. Twenty-four-hour intravenous insulin requirements were used to initiate CSII pump therapy, and further dose adjustments were undertaken, to optimize glycemic control. Basal, bolus, and total daily insulin requirements were calculated before, during, and 3 months after conversion to CSII therapy. RESULTS: At entry, the mean glycohemoglobin was 11.2% (normal, 5.0 to 8.0%), and the mean daily insulin dose were 45.8 U (0.59 U/kg). Calculated daily insulin requirements using an algorithm for intravenously administered insulin were 37.3 U (0.50 U/kg). At 3 months, mean daily insulin requirements had increased to 39.2 U (0.52 U/kg), and glycohemoglobin improved to 9.4%. Most patients (78%) remained on insulin doses within 10% of the calculated requirements. All patients who were receiving more than 0.6 U/kg daily before assessment required a reduction in insulin dosage to improve glycemic control. CONCLUSION: Many patients with type 1 diabetes are receiving excessive insulin doses. An algorithm for intravenous administration of insulin may be useful for determining requirements and appropriate insulin doses for CSII pump therapy, especially in patients with poor glycemic control.

Journal Article↗
PubMedDate not supplied

[Influence of restrictive use of antibiotics on the development of drug resistance in intestinal Escherichia coli from pigs (author's transl)].

A retrospective investigation into the drug resistance pattern of intestinal E. coli was carried out in 17 closely monitored herds in order to evaluate a possible influence of an improved diagnostic and a restrictive use of antibiotics in swine herds. The herds participated from October, 1970, in an investigation of preweaning mortality and morbidity, and during a two-year investigation period antibiotics were only used when therapeutically indicated. Sensitivity tests were regularly performed on the intestinal flora from post mortem examined pigs from the herds and the results forwarded to the local veterinarians. A total of 443 E. Coli strains were isolated in pure or almost pure culture from the jejunum of post mortem examined pigs and tested for sensitivity, using the following antibiotics: streptomycin, compound sulphonamide, neomycin, oxytetracycline, chloramphenicol, nalidixic acid, furazolidone, and ampicillin. During the investigation period, the frequency of isolated multiresistant E. coli strains decreazed from 67.7 per cent to 9.5 per cent and the number of strains without antibiotic resistance increased from 3.0 per cent to 36.2 per cent (Table I; Fig. 1). Herds were divided into 3 groups according to different intensity of antibiotic administration and to closed or open management system (Table II). The most pronounced decrease in the number of multiresistant E. coli strains (from 64.9 to 2.0 per cent) was observed in Group I, which comprises closed herds with a rapid decrease in the use of antibiotics. In Group II, which comprises semi-closed herds with a decreasing, but in the last year of the investigation still frequent use of antibiotics, a somewhat slower decrease of the number of multiresistant strains to a level of 12.1 per cent was observed. The number of strains without resistance increased to approximately the same level as in Group I. In Group III, which comprises open herds with infrequent use of antibiotics, the incidence of resistant E. coli strains fluctuated (Table III; Fig. 2). The resistance was proved transferable in 60.5 per cent of the examined resistant strains. The frequency of transferability did not show any significant change during the investigation period (Table IV). The most frequently encountered resistance determinants were: sulphonamide (97 per cent), streptomycin (40 per cent), and oxytetracycline (34 per cent). Only resistance against sulphonamide, streptomycin, tetracycline, and chloramphenicol was proved transferable (Table V). It is concluded that it is possible to obtain a simultaneous reduction of induced antibiotic resistance of intestinal E. coli and of enteric diseases in sucking pigs in commercial herds, by adjustment of management and rational use of antibiotics based on improved diagnostic including in vitro sensitivity tests.

Ampicillin↗
PubMedDate not supplied

An Aeromonas species implicated in ulcer-disease of the cod (Gadus morhua).

Vibrio anguillarum is the most frequently isolated bacterial species involved in ulcer disease in salt water fish. However, an Aeromonas species was very often incriminated in ulcers and septicaemia in cods (Gadus morhua) in Danish coastal areas. These Aeromonas strains were very uniform in their biochemical activities only differing in growth on Simmons citrate agar, and the mean value for the guanine + cytosine content of DNA was 59 per cent with a standard deviation of 0.4. Primary serological investigations demonstrated a possible identity to O and K antigens. The most characteristic biochemical features of these strains were a gas production from glycerol but not from glucose. They were positive in lysine decarboxylase, did not produce indole, and had a typical fermentation pattern of the glycosides. Negative results were found in H2S production, phosphatase and in the utilization of NH4+ and glucose as the only source of N and C. The evident differences from the species described and subspecies of Aeromonas elucidate the weakness of the existing systems of biotyping. A broader conception of the biochemical spectrum for the individual species of Aeromonas combined with serotyping would seem to be a better system for identification, and also for an epidemiological purpose.

Aeromonas↗