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T L Hansen

Publications and source records attributed to T L Hansen.

9 recordsLinked to original sources
PubMed2000

[Logbook. A possible method].

The European board of psychiatry recommends the use of a logbook and checklist. There has been discussion about the extent of registration--and the resources involved. We present a simple method of registering supervision. Trainees make a daily report of the amount of supervision received. The trial period was divided into two sections: March, April and May 1997; (training intensive) and June, July and August 1997; (holiday season). The trainees responded well to the logbook, the answering rate was 94.2% in the first period, 60.9% in the holiday season. Calculations based on the first period show that trainees receive supervision during 9.8% of their working hours (range 4.8-16.0). Twenty-nine percent of supervision is of the direct variety, where both trainer and trainee are present. This variety suffers during holiday season. This type of logbook provides an opportunity to be directed in training activities, with a minimum of resources involved.

Denmark↗
PubMed1983

A mutation of pyruvate carboxylase in fibroblasts from a patient with severe, chronic lactic acidaemia.

Pyruvate carboxylase activity was investigated in cultured fibroblasts from a patient shown to have hepatic pyruvate carboxylase deficiency. Under standard conditions, the activity in fibroblasts was 50% of controls (p less than 0.001). Kinetic investigations of the enzyme showed abnormal protein linearity with low activity at low protein concentration. Mixture of homogenates from the patient and a control revealed no endogenous inhibitor. Temperature stability of the mutant enzyme was similar to controls. Apparent kinetic constants for the substrates bicarbonate, ATP and pyruvate were in the patient 2.6 mmol/l, 0.08 mmol/l and 0.10 mmol/l compared to 2.1 mmol/l, 0.13 mmol/l and 0.22 mmol/l in controls, respectively. The 50% inhibitory concentration of oxaloacetate was 0.5 mmol/l in controls. However, no inhibitory effect of oxaloacetate was found for pyruvate carboxylase in fibroblasts from the patient. With acetyl-CoA, the apparent activation constant was 0.21 mmol/l in controls and 0.10 mmol/l in the patient, while the Hill coefficients were similar. These results may be explained by a mutation primarily affecting the transcarboxylation site of pyruvate carboxylase from the patient.

Acidosis↗
PubMed1983

Succinate dehydrogenase activity in cultured human skin fibroblasts and amniotic fluid cells. A methodological study.

Through a methodological evaluation, reliable histochemical and biochemical methods for succinate dehydrogenase activity in cultured human skin fibroblasts and amniotic fluid cells were developed. The histochemical method includes a cleaning of the cultured cells in 1 mM malonate in 0.9% NaCl, air-drying and fixation in acetone (5 min at -20 degrees C), coating of cells with CoQ10 (0.2 mg/ml in ether/acetone) and incubation for 1 h at 37 degrees C in 50 mM succinate and 0.5 mg/ml Nitro BT in 200 mM phosphate buffer, pH 7.6 PMS as an intermediate electron carrier was found inferior to exogenous CoQ10. Both types of cells exhibit equal activity. In the biochemical method homogenizing was performed in 50 mM Tris-HCl buffer, pH 7.5, and 200 mM sucrose. The standard incubation was 2.0 mM INT and 10 mM succinate in 10 mM Tris-HCl buffer, pH 7.5 for 1 h at 37 degrees C. The apparent Km values for INT and succinate were estimated to 0.39 mM and 0.13 mM, respectively, while I0.5 for malonate was 0.46 mM. Activity in amniotic fluid cells was 18.1 pkat/mg protein and in human skin fibroblasts 20.3 pkat/mg protein. Specificity of the methods was tested by use of a Chinese hamster fibroblast strain B9 known to be succinate dehydrogenase deficient in addition to various control experiments. Congruent results were obtained with the two methods.

Amniotic Fluid↗
PubMed1982

Determination of pyruvate dehydrogenase in cultured human fibroblasts and amniotic fluid cells.

A new assay method for pyruvate dehydrogenase in platelets [1] using in situ generation of [1-14C]pyruvate from [1-14C]lactate has been further developed for the use in cultured human fibroblasts and amniotic fluid cells. A very low blank rate was found compared to the method using [1-14C]pyruvate as substrate and an activity of 20 times the blank was obtained in normal fibroblasts and amniotic fluid cells. The pyruvate dehydrogenase was linear with time and protein concentration. The activity was greatly decreased by addition of non-radioactive pyruvate to the assay mixture and by preincubation with ATP. The cofactor requirement was similar to pyruvate dehydrogenase from other sources. Normal activities in cultured human fibroblasts and amniotic fluid cells were 13.9 pkat/mg protein (n = 15) and 21.7 pkat/mg protein (n = 10), respectively. The method was found to be very reliable and makes the diagnosis of pyruvate dehydrogenase deficiency possible in easily accessible tissue such as cultured fibroblasts. Prenatal diagnosis may also be a possibility.

Adenosine Triphosphate↗
PubMed1982

Studies on pyruvate carboxylase, pyruvate decarboxylase and lipoamide dehydrogenase in subacute necrotizing encephalomyelopathy.

In two autopsy-proven cases of subacute necrotizing encephalomyelopathy (SNE, Leigh's Disease) the activities of pyruvate carboxylase, pyruvate decarboxylase and lipoamide dehydrogenase were investigated in cultured fibroblasts. Normal activities of pyruvate carboxylase and lipoamide dehydrogenase were found in both cases. The activity of pyruvate decarboxylase was low in one of the cases (p less than 0.05), while the activity in the other was within normal limits. The concentrations of alanine, lactate and pyruvate were normal or only slightly increased. The relationship between SNE and a defect in pyruvate metabolism is under discussion, and it is concluded that the general assumption that pyruvate carboxylase deficiency is the cause of SNE is not in agreement with our results or the present literature. However, pyruvate decarboxylase deficiency may in some cases contribute to the development of SNE.

Alanine↗
PubMed1980

Studies on pyruvate carboxylase from cultured human fibroblasts and amniotic fluid cells.

The properties of pyruvate carboxylase in cultured human fibroblasts were investigated. A pH optimum around pH 7.6 was found in Tris buffer at 37 degrees C. The apparent Km for pyruvate and bicarbonate were 0.22 mmol/l and 2.1 mmol/l respectively. The activity of the crude homogenate was most stable at room temperature. The major end product was identified as citric acid during the assay conditions used. During growth the specific activity increased from 0.5 to 2 nmol/min per mg protein. The activity of pyruvate carboxylase in the crude homogenate from cultured human fibroblasts was 0.76 +/- 0.12 nmol/min per mg protein, while the activity in cultured amniotic fluid cells was 0.66 +/- 0.17 nmol/min per mg protein, suggesting the possibility of prenatal diagnosis of pyruvate carboxylase deficiency.

Amniotic Fluid↗