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Biomedical subjects

H Seim

Publications and source records attributed to H Seim.

At least 19 recordsLinked to original sources
PubMed2005

Abnormal neuronal metabolism and storage in mucopolysaccharidosis type VI (Maroteaux-Lamy) disease.

Mucopolysaccharidosis (MPS) type VI, also known as Maroteaux-Lamy disease, is an inherited disorder of glycosaminoglycan catabolism caused by deficient activity of the lysosomal hydrolase, N-acetylgalactosamine 4-sulphatase (4S). A variety of prominent visceral and skeletal defects are characteristic, but primary neurological involvement has generally been considered absent. We report here that the feline model of MPS VI exhibits abnormal lysosomal storage in occasional neurones and glia distributed throughout the cerebral cortex. Abnormal lysosomal inclusions were pleiomorphic with some resembling zebra bodies and dense core inclusions typical of other MPS diseases or the membranous storage bodies characteristic of the gangliosidoses. Pyramidal neurones were shown to contain abnormal amounts of GM2 and GM3 gangliosides by immunocytochemical staining and unesterified cholesterol by histochemical (filipin) staining. Further, Golgi staining of pyramidal neurones revealed that some possessed ectopic axon hillock neurites and meganeurites similar to those described in Tay-Sachs and other neuronal storage diseases with ganglioside storage. Some animals evaluated in this study also received allogeneic bone marrow transplants, but no significant differences in neuronal storage were noted between treated and untreated individuals. These studies demonstrate that deficiency of 4S activity can lead to metabolic abnormalities in the neurones of central nervous system in cats, and that these changes may not be readily amenable to correction by bone marrow transplantation. Given the close pathological and biochemical similarities between feline and human MPS VI, it is conceivable that children with this disease have similar neuronal involvement.

Animals↗
PubMed2002

Effects of oral L-carnitine supplementation on in vivo long-chain fatty acid oxidation in healthy adults.

Despite an abundance of literature describing the basic mechanisms of action of L-carnitine metabolism, there remains some uncertainty regarding the effects of oral L-carnitine supplementation on in vivo fatty acid oxidation in normal subjects under normal conditions. It is well known that L-carnitine normalizes the metabolism of long-chain fatty acids in cases of carnitine deficiency. However, it has not yet been shown that L-carnitine influences the metabolism of long-chain fatty acids in subjects without disturbances in fatty acid metabolism. Therefore, we investigated the effects of oral L-carnitine supplementation on in vivo long-chain fatty acid oxidation by measuring 1-[(13)C] palmitic acid oxidation in healthy subjects before and after L-carnitine supplementation (3 x 1 g/d for 10 days). We observed a significant increase in (13)CO(2) exhalation. This is the first investigation to conclusively demonstrate that oral L-carnitine supplementation results in an increase in long-chain fatty acid oxidation in vivo in subjects without L-carnitine deficiency or without prolonged fatty acid metabolism.

Administration, Oral↗
PubMed2001

The relative efficacy of fluoxetine and manual-based self-help in the treatment of outpatients with bulimia nervosa.

A randomized, placebo-controlled study was conducted examining the singular and combined effects of fluoxetine and a self-help manual on suppressing bulimic behaviors in women with bulimia nervosa. A total of 91 adult women with bulimia nervosa were randomly assigned to one of four conditions: placebo only, fluoxetine only, placebo and a self-help manual, or fluoxetine and a self-help manual. Subjects were treated for 16 weeks. Primary outcome measures included self-reports of bulimic behaviors. Fluoxetine and a self-help manual were found to be effective in reducing the frequency of vomiting episodes and in improving the response rates for vomiting and binge-eating episodes. Furthermore, both factors were shown to be acting additively on the primary and secondary efficacy measures in this study. Results are discussed in relation to previous research and the implications for treatment of bulimia nervosa.

Adolescent↗
PubMed1999

Eating disorders and psychiatric disorders in the first-degree relatives of obese probands with binge eating disorder and obese non-binge eating disorder controls.

OBJECTIVE: The purposes of the present study were to examine the possibility of a familial tendency for binge eating disorder (BED) among the obese, to clarify the relationship between BED and other eating disorders, and to test the relationship between BED and other psychiatric disorders. METHOD: We studied 32 female BED outpatients and 23 obese females without BED. A possible history of eating disorders was assessed using the Structured Clinical Interview for DSM-III-R-Eating Disorders section administered by telephone interview. Family history information for other psychiatric disorders was collected using the Family History Research Diagnostic Criteria RESULTS: The frequency of all eating disorders and the risk for other psychiatric disorders were not significantly different between the relatives of the two groups. These results were consistent across generation and gender. DISCUSSION: This study failed to show a familial tendency for BED, or any significant familial relationship between BED and other eating disorders, and did not support the hypothesis of coaggregation of other psychiatric disorders with BED.

Adult↗
PubMed1998

Carnitine metabolism and its regulation in microorganisms and mammals.

In procaryotes, L-carnitine may be used as both a carbon and nitrogen source for aerobic growth, or the carbon chain may be used selectively following cleavage trimethylamine. Under anaerobic conditions and in the absence of preferred substrates, some bacteria use carnitine, via crotonobetaine, as an electron acceptor. Formation of trimethylamine and lambda-butyrobetaine (from reduction of crotonobetaine) from L-carnitine by enteric bacteria has been demonstrated in rats and humans. Carnitine is not degraded by enzymes of eukaryotic origin. In higher organisms, carnitine has specific functions in intermediary metabolism. Concentrations of carnitine and its esters in cells of eukaryotes are rigorously maintained to provide optimal function. Carnitine homeostasis in mammals is preserved by a modest rate of endogenous synthesis, absorption from dietary sources, efficient reabsorption, and mechanisms present in most tissues that establish and maintain substantial concentration gradients between intracellular and extracellular carnitine pools.

Animals↗
PubMed1993

Cognitive-behavioral group psychotherapy of bulimia nervosa: importance of logistical variables.

Although much of the psychotherapy for psychiatric disorders is conducted on a weekly basis, several researchers in the field of bulimia nervosa have utilized a more intensive approach as a means to strengthen treatment effects. A second issue concerns the amount of emphasis that should be placed on encouraging the interruption of bulimic symptoms early in treatment. In the current study we systematically studied these two issues. Subjects were randomly assigned to one of four forms of cognitive-behavioral group psychotherapy, the four cells differing on the variables of intensity and emphasis on abstinence. The results indicate that a high intensity approach, an early abstinence approach, or a combination of these two approaches are all significantly more effective in inducing remission in patients with bulimia nervosa compared with a weekly psychotherapy that uses the same manual-based cognitive-behavioral therapy approach.

Adolescent↗
PubMed1990

Reexamination of the 1H NMR assignments and solution conformations of L-carnitine and O-acetyl-L-carnitine using C-2 stereospecifically labeled monodeuterated isomers.

The two C-2 monodeuterated isomers of L-carnitine were synthesized by enzymatic hydration of crotonobetaine in D2O and by enzymatic proton exchange of L-[2-2H2]carnitine in H2O. These reactions, catalyzed by an induced Escherichia coli carnitine hydrolyase proceed stereospecifically. The two isomers of L-[2-2H]carnitine were examined by 1H NMR at 500 MHz, which allowed us to independently monitor the pD dependence and coupling constants of the H-2 protons. The results obtained indicate that there is little effect of the carboxyl charge on the conformational state(s) of L-carnitine about the C-2/C-3 bond. The NMR data obtained in this study do not support previous solution studies of the pH-dependent conformational changes for DL-carnitine nor the proposed conformation of O-acetyl-DL-carnitine in the crystalline state.

Acetylcarnitine↗
PubMed1990

[The effect of L-carnitine on the energy metabolism of isolated rat heart perfused by Langendorff's method using 31P-NMR spectroscopy].

31P-NMR spectroscopy is a method for continuous, noninvasive determination of high-energy phosphates in the intact organ. On the isolated Langendorff perfused rat heart the effect of L-carnitine on concentration of cytosolic ATP and phosphocreatine was studied under influence of a single or repeated periods of 20 min ischemia. On reperfusion the carnitine-treated hearts showed higher CP/Pi values and an increase of the energy index (CP + ATP)/(C) + ATP + Pi) then did control hearts. An improved ischemia tolerance was demonstrated.

Adenosine Triphosphate↗
PubMed1989

[Occupational diseases among personnel at a radiology department].

Little attention has hitherto been paid to health injuries to personnel in X-ray departments after exposure to photochemicals. 24 out of 30 employees at the X-ray department in Molde were shown to have health problems related to their work, including symptoms relating to the eyes, the upper and lower respiratory tract, and headache and lassitude. Analysis of the work environment showed constant extensive exposure of the employees to chemicals over a long period. After improvements to the environment the health problems were reduced appreciably, but not nullified. Some personnel had acquired permanent impairments. Bronchial hyperreactivity was discovered in 19 of the personnel, 13 of whom had subjective symptoms of obstruction and asthma but no manifestation of allergy. The author discussed the relation between the work environment and the impaired health and gives advice on how to avoid similar problems in the future.

Adult↗
PubMed1989

[Secondary L-carnitine deficiency in chronic hemodialysis patients].

L-carnitine is an essential substance for the decomposition of long-chain fatty acids and thus for the obtaining of energy in the mitochondria. The L-carnitine fractions in the serum were analysed in 10 patients undergoing haemodialysis before and after the dialysis treatment. 4 patients received a substitution of L-carnitine by oral application of 3.0 and 1.0 g, respectively, after every dialysis or as addition to the dialysate (ca. 62 mumol/l) for in each case 4 weeks. In patients undergoing dialysis the serum carnitine fractions were in many cases already clearly diminished before the dialysis. During the treatment the total L-carnitine levels decreased by ca. 50%, the free L-carnitine values by ca. 70%. Particularly distinct carnitine depletions were found in patients with catabolic metabolic condition, incompatibility of dialysis and post-dialysis syndrome. All forms of application and dosages chosen led to a good correction of the serum carnitine concentrations. 2 patients with oral L-carnitine substitution of 3.0 g and resulting from this serum carnitine levels highly significantly lying above the normal region mentioned ameliorations of the subjective lipid parameters cholesterol, HDL-cholesterol and triglycerides could not be changed in the short period of observation by substitution of L-carnitine.

Adult↗
PubMed1987

Ketosis, serum carnitine and its precursor amino acids in normal and diabetic ethiopians.

In a hospital-based study in northwestern Ethiopia some clinical and biochemical features of diabetes mellitus have been assessed to contribute to the problem of classification of diabetes in a tropical country. Diabetes requiring primary insulin treatment is presented by unequivocally elevated blood glucose levels and the classic symptoms of the disease. Newly discovered cases and readmitted rural diabetics show significantly lower body mass indices and 31% have been classified as underweight. The overall frequency of ketonuria at (re)admission was 45% together with moderately elevated or high 3-hydroxybutyrate serum concentrations. The hormonal status is characterized by a reduced beta-cell function. Serum concentrations of all carnitine fractions are lower in both normal and diabetic Ethiopians when compared with Caucasoids. Carnitine precursor amino acids are normal and the complete amino acid spectrum reveales no clear-cut pattern related to protein-energy malnutrition.

Acidosis↗
PubMed1987

Carnitine and experimental carbohydrate-induced hyperlipoproteinemia.

Carnitine, beta-hydroxy-gamma-trimethylaminobutyrate, plays an important role as a factor necessary for the transport of long-chain fatty acids into the mitochondria. In order to investigate the influence of L(--)-carnitine on hyperlipoproteinemias, the experimental model of the sucrose-induced hypertriglyceridemia of the rat was used. In these experiments L(--)-carnitine in the dose of 11 mg per day and 100 g body weight was able to antagonize the sucrose-induced hypertriglyceridemia and the increase of serum-free fatty acid level in female rats of the Wistar strain. Carnitine administration did not change the activities of lipogenic liver enzymes and the activity of post-heparin lipase. On the other hand, carnitine administration increased the rate of fatty acid oxidation in the liver. The main result of the study, i.e. the lipid-lowering effect of L-carnitine, suggests the use of this compound in the therapy of hyperlipoproteinemias.

Animals↗
PubMed1985

Chronotropic effects of the reversed carboxyl (RC) analogue of acetylcholine (beta-homobetaine methylester) at defined intraluminal pressures on isolated right rabbit atria.

With continuous perfusion at transmural pressures of 0.1 and 0.5 kPa, beta-homobetaine methylester (HBM) decreased the rate of spontaneously beating atria significantly with an ED50 of about 5 X 10(-6) mol/l. The dose-dependent decrease in the atrial rate was stronger at an intraluminal pressure of 0.5 kPa, at this pressure the dose-response curve sloped more steeply. The stretch acceleration of the atrial rate was also significantly inhibited by HBM. In comparison with acetylcholine, the HBM was over 10 times more effective. Atropine blocked the interactions of the HBM with the muscarinic cholinergic receptors of the pacemaker cells.

Acetylcholine↗
PubMed1985

Catabolic pathways for high-dosed L(-)- or D(+)-carnitine in germ-free rats?

Gnotobiotic rats received up to 3 mmol L-carnitine/day with the drinking water during 9 days. They excreted about a quarter of the administered dose with the urine, partially in form of acetyl-L-carnitine, but trimethylamine, trimethylamine N-oxide or gamma-butyrobetaine were not detectable in urine or faeces in contrast to conventional animals. After oral loading with D-carnitine the unphysiological isomer was absorbed and either excreted unchanged in urine or metabolized to acetonyltrimethylammonium. With regard to the development of carnitine deficiency syndromes and the degradation of nutritional carnitine the conclusion has to be drawn, that the bacteria of the gastro-intestinal tract, but not the tissues of the mammals, are responsible for the metabolization of L-carnitine to gamma-butyrobetaine or trimethylamine.

Acetylcarnitine↗