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L Steen

Publications and source records attributed to L Steen.

At least 55 records · Page 3Linked to original sources
PubMed1987

Identification and characterization of a specific dolichylmonophosphate phosphatase activity in bovine thyroid microsomes.

Bovine thyroid membranes are able to dephosphorylate exogenous [1-3H]DMP as well as endogenous prelabeled [32P]DMP. The kinetics, properties and specificity of the dolichylmonophosphatase activity have been studied by monitoring respectively the release of [1-3H]dolichol from [1-3H]DMP and the residual amount of [32P]DMP. The DMP-phosphatase activity is not linear with respect to time and exhibits a neutral pH optimum. There is only linearity in a narrow range of protein concentration when 0.25% Triton X-100 is included in the incubation mixture. Studying the enzymatic activity in function of protein concentration, the detergent requirement shows to be very critical. Triton X-100 is necessary for enzymatic activity with [1-3H]DMP (only 10% of enzymatic activity in the absence of detergent) although the detergent inhibits the hydrolysis of endogenous prelabeled [32P]DMP. Divalent cations are not essential for enzymatic activity, Ca2+-ions being even inhibitory. In accordance, EDTA (EGTA) is slightly stimulatory. The DMP-Pase activity is not influenced by the ionic strength of the incubation system and sulphydryl groups are not involved. NaF, VOS and VO4(3-) are strongly inhibitory. The inhibition by dolichol and PO3-4 can be explained as the result of product inhibition. An apparent Km-value of 2.5 X 10(-5) M is computed for [1-3H]DMP. Bacitracin inhibits DMP-phosphatase in contrast with other reports. Propylthiouracyl, cAMP, TSH and several other bio-effectors are without effect on the in vitro system. The specificity of the DMP-Pase activity is discussed, showing that the phosphatase is distinctly different from other phosphatases especially phosphatidic acid phosphohydrolase.

Animals↗
PubMed1984

Identification and characterization of dolichyl dolichoate, a novel isoprenoic derivative in bovine thyroid.

Inspection of the TLC pattern of the neutral lipid fraction of bovine thyroid reveals, in addition to cholesteryl esters and dolichyl fatty acid esters, the presence of a not yet identified compound in the most apolar lipid region. This unknown compound was purified on a preparative scale by silicic acid column chromatography, Lipidex-5000 gel-filtration chromatography and preparative thin-layer chromatography. By chemical (hydrolysis and reduction) and spectroscopic (ultraviolet, infrared, NMR, mass spectroscopy) methods this lipid was identified as dolichyl dolichoate. The homologue pattern was analyzed, by HPLC and FDMS, respectively.

Animals↗
PubMed1984

Spectrophotometric determination of dolichol and dolichyl derivatives using the Chugaev color reaction.

A simple colorimetric method for the assay of microamounts of dolichol is described. It is based essentially on the Chugaev color reaction. The procedure allows the rapid (1 h after purification of the sample, less than half a day for the whole procedure) and reliable (% SE less than or equal to 5%) determination of dolichol and dolichyl derivatives in the microgram range. Color production is linear within the concentration range 2 to 20 micrograms dolichol. With biological samples, prior to colorimetric assay, dolichol and dolichyl derivatives are isolated by solvent extraction and TLC. Recoveries are monitored by isotope dilution analysis. The method has been used for the analysis of dolichol and dolichyl ester levels in bovine thyroid tissue. The procedure can also be applied for the analysis of other isoprenoids.

Animals↗
PubMed1984

Studies of the effect of diet on saliva secretion and caries development: the effect of fasting on saliva composition of female subjects.

In the present investigation 11 females of normal constitution were subjected to a standardized fasting diet for 8 days. Three subjects dropped out early during the experimental period. Saliva and blood samples were collected before, during and after the fasting period. Serum analyses were made of some parameters often studied during undernutrition. As expected, values for creatinine and uric acid were increased. Secretion rate, pH, buffer capacity, electrolytes, total protein, carbohydrates, some antibacterial substances, the amount of Streptococcus mutans, total streptococci, and lactobacilli were determined in the saliva samples. The rate of plaque formation was also estimated. The effect of fasting on the measured parameters varied greatly among the individuals. Fasting caused a significant decrease in secretion rate, concentration of phosphate and sialic acid in stimulated whole saliva. There was no significant increase in concentration of any substance measured. The decrease of the ratio of sialic acid to protein indicates a disturbance of glycoprotein synthesis. In resting saliva the activity of a bacteria-aggregating glycoprotein appeared to be unchanged, whereas the decreases in thiocyanate concentration and lysozyme activity were statistically significant. Lactoperoxidase activities did not change significantly. The amount of IgA, IgG, IgM as well as the microbial counts showed no changes. The rate of plaque formation increased during fasting.

Adult↗
PubMed1984

Skeletal lesions and arterial calcifications of the feet in diabetics.

A radiological study of the feet was performed in 162 unselected diabetic patients with gangrene. They were compared with 59 diabetic patients without gangrene, 45 patients with familial amyloidosis and polyneuropathy and 30 healthy controls. The patients with familial amyloidosis had severe distal neuropathy but normal oral glucose tolerance test curves. Radiographic findings, e.g. skeletal destructions (diabetic osteopathy) and arterial calcification of the medial type were classified without knowledge of the clinical findings. Osteopathy was more common in diabetic patients with gangrene than in the other groups of patients. Medial arterial calcification was more common among diabetics with gangrene compared to patients with amyloidosis and to controls. There were no differences between diabetics without gangrene and patients with amyloidosis, but both of these groups had more calcifications than the controls. Our study suggests that diabetic osteopathy is not caused by peripheral neuropathy per se. The skeletal and skin lesions in diabetic patients are probably equivalent lesions localized to different tissues in the feet. It has been suggested that medial degeneration in the arterial wall is due to neuropathy. In agreement with this suggestion, the patients with familial amyloidosis and neuropathy had medial calcification. However, in diabetic patients this does not exclude other etiological agents.

Aged↗
PubMed1984

Effect of long-term penicillamine therapy on erythrocyte CuZn superoxide dismutase activity.

The effect of long-term penicillamine therapy on erythrocyte CuZn superoxide dismutase activity was investigated. For comparison the serum ceruloplasmin and serum copper contents were also analysed. Seven of the 11 penicillamine-treated patients had CuZn superoxide dismutase activities below the reference interval of the parameter. Levels down to about 50% of the mean of controls were observed in several cases. In five and in four of the 11 patients respectively decreases in serum ceruloplasmin and serum copper were found. Whereas among the penicillamine-treated patients there was a good correlation between serum ceruloplasmin and serum copper, the correlation between these parameters and erythrocyte CuZn superoxide dismutase was only fair. Erythrocyte CuZn superoxide dismutase is probably a suitable parameter for monitoring intracellular copper availability during penicillamine therapy.

Adult↗
PubMed1983

Relationship between morphological findings and function of the small intestine in familial amyloidosis with polyneuropathy.

Twenty-seven patients with familial amyloidosis with polyneuropathy were studied with regard to the morphology of the small intestine, and this was correlated to symptoms and malabsorption features. The mucosa was normal in all cases investigated by the dissecting microscope, the light microscope, and the scanning electron microscope. Amyloid was demonstrated in 83% of the cases by the presence of green birefringent material in the biopsy specimens stained with alkaline Congo red and examined in polarized light. Nineteen patients had steatorrhea, and 12 had pathological D-xylose test results. The degree of amyloid infiltration did not correlate with these data, nor did the symptomatic state correlate with the amount of amyloid in the biopsy specimens. The surface ultrastructure was normal when investigated by means of the scanning electron microscope in all patients except five in whom the glycocalyx was altered. As a group, however, those five did not differ in any respect from the rest of the patients. Rod-shaped microorganisms were shown to adhere to the surface in one patient. The results suggest that mechanisms other than bowel-wall deposition of amyloid cause the dysfunction of the gastrointestinal tract in familial amyloid polyneuropathy.

Adult↗
PubMed1983

Familial amyloidosis with polyneuropathy. A long-term follow-up of 21 patients with special reference to gastrointestinal symptoms.

In a longitudinal study, 21 patients with familial amyloidosis with polyneuropathy (FAP) were followed up for more than three years. Gastrointestinal symptoms ultimately evolved in all patients. In the advanced stage of the disease, 13 patients had diarrhea together with anal incontinence. Weight loss was very common and related to both malabsorption and motility disturbances with anorexia and also to muscular atrophy. Steatorrhea was found in 19 patients at least once during the follow-up. The duration of the disease was significantly correlated to fecal fat output. The conclusion was drawn that the gastrointestinal involvement in FAP is very common and of great clinical importance. The consequences of malnutrition also influence the outcome of the disease.

Adult↗
PubMed1982

Renal function in familial amyloidosis with polyneuropathy.

The renal function is assumed to be normal in most patients with familial amyloidosis with polyneuropathy (FAP) type 1. In the present study of 24 patients with FAP type 1, estimation of the urinary concentrating capacity and 51Cr-EDTA clearance demonstrated that the glomerular clearance and the concentrating capacity were imparied in most patients. The concentrating capacity was significantly correlated with the clearance values. Urine electrophoresis indicated a glomerular cause for the proteinuria. It is suggested that the renal dysfunction should be attributed to deposition of amyloid substance in the glomeruli.

Adolescent↗
PubMed1981

Effect of fifteen months of double-blind treatment with cimetidine and placebo on peptic ulcer recurrence.

Forty-Five consecutive patients with chronic peptic ulcer disease completed a double-blind controlled trial in which they were given cimetidine 0.8 g daily or placebo in order to evaluate the preventative effect of the drug on ulcer recurrence. On entering the trial all patients had endoscopically healed ulcers. Endoscopy was performed again at 6 and 15 months, or if there were severe epigastric pains. The period of medication was 15 months, and the patients still in remission at that time were observed for a further 9 months. During the course of the study 11 out of 23 patients (47.8%) in the placebo group developed re-ulceration, whereas 4 out of 22 (18.2%) patients relapsed while on cimetidine (p less than 0.05). There were significantly fewer weeks of dyspepsia and better general well-being in the cimetidine group as compared to the placebo group. No early ulcer recurrence or increased rebound acid secretion was noted after cessation of the cimetidine treatment. Vitamin B12 absorption was not affected by the 15-month cimetidine treatment. Two men developed gynaecomastia, one died of myocardial infarction and one had transient sinus bradycardia during cimetidine medication. Cimetidine improves the symptomatic state and postpones ulcer recurrence as long as treatment is maintained.

Adult↗
PubMed1981

Familial amyloidosis with polyneuropathy - type 1. A neurophysiological study of peripheral nerve function.

Twenty-four consecutive patients with familial amyloidosis with polyneuropathy (type 1), who were at different stages of the disease were investigated. The purpose was to report the electrophysiological features and to compare them with those found in other generalized neuropathies; 12 cases were familiar and 12 cases were sporadic. The diagnosis was confirmed by examining the occurrence of amyloid substance in rectal or skin biopsies or both. Single fiber EMG with fiber density determination showed signs of collateral innervation, prominent in advanced cases, and a disturbance of neuromuscular function similar to that of progressive spinal motorneuron disease. Action potentials from afferent fibers were not obtained in 91% of the nerves in the lower and 49% of the nerves in the upper extremities. When sensory or motor or slightly subnormal. The neurophysiological findings indicate a symmetrical axonal degeneration, starting in the legs. Familial amyloidosis with polyneuropathy should be suspected in cases of rapidly progressing polyneuropathy of axonal type with onset in middle age, irrespective of whether they are hereditary or not.

Adult↗
PubMed1980

The relationship between active peptic ulcer, endoscopic duodenitis and symptomatic state after treatment with cimetidine.

Fifty patients with active peptic ulcers on endoscopy were randomly allocated for treatment with placebo or cimetidine (1.0 g daily) over a period of four weeks. All patients had free access to antacids to relieve epigastric pain. In the cimetidine group a significantly higher proportion of the ulcers had healed (82.6% of the patients) compared with the placebo group (48.0%). There was poor correlation between the healing of the ulcer and dyspeptic symptoms in the placebo group. The results suggest that the presence of endoscopic duodenitis is to a great extent responsible for the dyspepsia. Cimetidine treatment, besides healing the ulcers, also improved the endoscopic duodenitis and the symptomatic state more than placebo treatment. No significant clinical side effects were observed. Chemical abnormalities were only noted with respect to serum creatinine. In the cimetidine group there was a statistically significant rise in serum creatinine, which was most apparent after two weeks of treatment. However, the increase was slight and not significant among the males, whereas in the case of the females there was a large and highly significant rise. The reason for this sex difference is at present unknown.

Adolescent↗
PubMed1979

Effect of long term treatment with hydrophilic colloid on serum lipids.

Thirteen patients with essential hyperlipoproteinaemia were treated over periods of 2--29 months with hydrophilic colloid made from Psyllium. Reduction of the increased serum cholesterol levels averaged 16.9 per cent, and the corresponding figure for the increased triglyceride levels was 52.0 per cent. The reduction of cholesterol and triglyceride was statistically significant (p less than 0.0025 and p less than 0.0005 respectively). No significant change in normal blood lipid levels was observed on administration of the Psyllium colloid.

Adult↗
PubMed1978

Persistent hypothalamic-pituitary insufficiency following acute meningoencephalitis. A report of two cases.

This report concerns two patients, a 43-year-old woman and a 53-year-old man, who developed clinical as well as laboratory signs of permanent gonodal and thyroid failure following an acute intracranial infection--in the woman a meningoencephalitis of unknown origin, and in the man an encephalitis caused by Coxsackie B5. Endocrine investigations were compatible with hypothalamic-pituitary dysfunction, with some of the results favoring a hypothalamic lesion. Perhaps hormone deficiency of hypothalamic and/or pituitary origin is a more common sequel of acute meningoencephalitis than has hitherto been reported.

Acute Disease↗
PubMed1978

[Postoperative changes of blood gases after uncomplicated abdominal surgery in geriatric patients (author's transl)].

In 34 elderly male and female patients undergoing upper abdominal surgery under general anaesthesia we investigated duration and degree of postoperative hypoxaemia. In this study only patients with no signs and symptoms of pulmonary or cardiac diseases, verified by normal lung function--vital capacity and FEV1, X-ray and electrocardiographic findings were considered. Postoperative development was free of complications and temperature rises in all cases. The investigations showed occurrence of arterial hypoxaemia during the postoperative period with values near the lower limit where the organism must fall back on cardio-circulatory reserve mechanisms in order to avoid general hypoxydosis. Regarding the restricted pulmonary and cardiac capacity for adaptation and compensation in geriatric patients, we recommend to prolong the practice of O2-application for two or three hours over a period of 24 to 48 hours, especially in patients with postoperative complications such as prolonged gastric atony, temperature, haemorrhage or cardiac and coronary insufficiency. This prolonged application of oxygen by mask or nasal tube should go parallel to other physiotherapeutic measures.

Abdomen↗