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Biomedical subjects

H Andersson

Publications and source records attributed to H Andersson.

At least 109 records · Page 6Linked to original sources

Sugar-beet fibre increases cholesterol and reduces bile acid excretion from the small bowel.

The effect of addition of sugar-beet fibre to the diet on sterol excretion from the small intestine was studied in nine ileostomy subjects. A constant low-fibre diet was given in two 3 d periods with and without 32 g sugar-beet fibre/d in random order. Care was taken to minimize bacterial alteration of the ileostomy contents. The addition of sugar-beet fibre increased net cholesterol excretion by 52 (SE 9)% (P < 0.01), from 294 (SE 99) to 451 (SE 124) mg/d, and decreased bile acid excretion by 26 (SE 15)% (P < 0.01), from 764 (SE 118) to 567 (SE 96) mg/d. The increased cholesterol and decreased bile acid excretion found with sugar-beet fibre addition is different from the pattern associated with fibre sources such as pectin and oat fibre. The interaction between dietary fibre and sterol metabolism may be mediated, therefore, by different mechanisms depending on the fibre source.

Adult↗

Normal pressure hydrocephalus: psychiatric findings before and after shunt operation classified in a new diagnostic system for organic psychiatry.

23 patients with normal pressure hydrocephalus (NPH) underwent psychiatric examinations prior to and 80 days to 10 months after a ventriculo-peritoneal shunt operation. A global evaluation of the effect of the operation on the patients' mental symptoms indicated appreciable improvement in 10 cases and slight improvement in a further 4.8 patients were assessed as unchanged, and one as mentally deteriorated. The psychiatric analyses was based on a new diagnostic system created by two of the authors (G.L., H.M.). The patients manifested varying, often complex psychiatric symptom constellations with symptomatological components from two or more organic mental disorders. Before the operation a mild or a moderately severe somnolence-sopor-coma disorder (SSCD) was diagnosed in 10 cases. After the operation all these patients became free from symptoms of SSCD. This was the most unequivocal change in connection with the operation, and the elimination of all symptoms of SSCD was the single factor which most effectively contributed to the total therapeutical result in these patients. All 23 cases were considered to have symptoms of a more or less severe astheno-emotional disorder (AED) preoperatively. The degree of severity of this disorder could not be determined with satisfactory certainty in some of the patients with complex symptoms. Amongst the 17 cases where the preoperative symptomatology allowed for a reasonably precise calculation of the degree of severity of AED, 6 were assessed as markedly improved after the operation and 10 as largely unchanged. In one patient, symptoms of the AED increased when the postoperative course was complicated by a subdural haematoma. Symptoms of an emotional-motivational blunting disorder (EMD) were diagnosed in 5 cases before the operation. After the operation 3 of these patients were symptom free in this respect while 2 unchanged. Slight or moderately severe symptoms of Korsakoff's amnestic disorder (KAD) were before the operation found in 7 cases: at the postoperative examination 6 of these cases were improved, of which 4 were free from such symptoms; one was unchanged. According to our experience, confident prognoses concerning the effect of the shunt operation on symptoms of SSCD can be made preoperatively, while, for a particular patient, the therapeutic effect on AED, EMD and KAD is often difficult, or sometimes impossible, to foresee. This article contains three case reports which represent different forms and courses of the mental symptom patterns.

Affective Symptoms↗

Different positively charged amino acids have similar effects on the topology of a polytopic transmembrane protein in Escherichia coli.

Integral membrane proteins from a wide variety of sources conform to a "positive-inside rule," with many more positively charged amino acids in their cytoplasmic as compared to extracytoplasmic domains. A growing body of experimental work also points to positively charged residues in regions flanking the apolar transmembrane segments as being the main topological determinants. In this paper, we report a systematic comparison of the effects of positively (Arg, Lys, His) as well as negatively (Asp, Glu) charged residues on the membrane topology of a model Escherichia coli inner membrane protein. Our results show that positive charge is indeed the major factor determining the transmembrane topology, with Arg and Lys being of nearly equal efficiency. His, although normally a very weak topological determinant, can be potentiated by a lowering of the cytoplasmic pH. Asp and Glu affect the topology to similar extents and only when present in very high numbers.

Amino Acid Sequence↗

Effect of oat bran on plasma cholesterol and bile acid excretion in nine subjects with ileostomies.

A higher excretion of dry matter, fat, nitrogen, energy, and total bile acids in ileal effluents; a lower plasma low-density-lipoprotein (LDL) and total cholesterols (12.1% and 9.0% lower respectively); but no change in plasma high-density-lipoprotein (HDL) cholesterol or apolipoproteins A-I and B were observed in nine subjects with ileostomies when they consumed an oat-bran, bread-based, high-fiber diet (HFD) as compared with a wheat-flour, bread-based, low-fiber diet (LFD) for 3 wk with a crossover design. Of the nine subjects only the subjects with a low daily excretion of bile acids had an elevated excretion of total bile acids during the HFD compared with the LFD. Total cholesterol, LDL cholesterol, and apolipoprotein B in plasma also decreased by 11.3%, 15.3%, and 10.7%, respectively, after consumption of the HFD for 3 wk.

Adult↗

Fatal systemic poisoning after skin exposure to monochloroacetic acid.

Little information is available on the toxicity of monochloroacetic acid. We report the case of a 38 year-old man who was splashed with an 80% monochloroacetic acid solution on 25-30% of his body surface. In addition to epidermal and superficial dermal burns, features of systemic poisoning occurred within a few hours including disorientation, agitation, cardiac failure and coma. He later developed severe metabolic acidosis, rhabdomyolysis, renal insufficiency and cerebral edema, and died due to uncal herniation on d 8. The 4 h post exposure plasma monochloroacetic acid concentration was 33 mg/L confirming skin absorption. In addition to its corrosive action, monochloroacetic acid probably blocks the tricarboxylic acid cycle (Kreb's cycle) and may also react with sulfhydryl groups in enzymes, causing severe tissue damage in energy-rich organs.

Accidents↗

A retrospective study of osseointegrated skin-penetrating titanium fixtures used for retaining facial prostheses.

This investigation was conducted to evaluate osseointegrated skin-penetrating facial titanium implants used for anchoring facial prostheses over a 5-year period and to recommend guidelines for the use of osseointegrated implants in the restorative treatment of auricular and orbital defects. The total success rate for implant survival was 95.6% in the auricular defects and 67.2% in the orbital defects. Approximately 10% of the patients will have some skin problems, whereas the remaining 90% will have no or minimal problems. The possibility of achieving osseointegration around an orbital defect is not as good as in the mastoid process. Success criteria for the use of implants in the craniofacial region are given.

Adolescent↗

The ileostomy model for the study of carbohydrate digestion and carbohydrate effects on sterol excretion in man.

The ileostomy model offers a method for direct, accurate and quantitative determination of small bowel excretion, provided the bacteriological degradation of the effluent can be minimized. The intraindividual variation is small, and rapid changes in excretion pattern due to dietary manipulations can be measured. Such ileostomy investigations have been important for developing the resistant starch and dietary fibre concepts. Using this method, various mechanisms for effects of dietary fibre on plasma lipids can be elucidated, e.g. binding of cholesterol, bile acids and/or lipids. Another application is to study the capacity of phytic acid and its degradation products to bind minerals in the small bowel.

Dietary Fiber↗

Olive oil instead of butter increases net cholesterol excretion from the small bowel.

Butter was replaced by olive oil in a controlled 100 g fat diet in order to study the effect of saturated fats (SAFA) versus monounsaturated fats (MUFA) on small-bowel sterol excretion in eleven healthy ileostomates. Bile acids and neutral sterols were measured by gas-liquid chromatography. Net cholesterol excretion (excretion minus intake) was 84 +/- 25 mg/24 h (mean +/- SE) on the SAFA diet and increased to 218 +/- 32 mg/24 h on the MUFA diet (P less than 0.01). The bile acid excretion tended to be somewhat lower on the MUFA diet, but this was significant only for chenodeoxycholic acid. Net sterol excretion (the sum of excretion of net cholesterol and bile acids) was significantly lower on the SAFA diet than on the MUFA diet (443 +/- 60 and 529 +/- 58 mg/24 h, respectively). The immediately increased excretion of cholesterol from the small bowel could thus explain the serum cholesterol-lowering effect of a change from a SAFA-rich to a MUFA-rich diet, though the mechanism for this change is still unclear.

Adult↗

Dietary treatment of dermatitis herpetiformis.

Essentially all patients with dermatitis herpetiformis (DH) and dermal granular IgA deposits have a gluten-sensitive enteropathy as seen in coeliac disease. A gluten-free diet would normally restore mucosal morphology within months. The dapsone medication required to suppress the skin lesions could be gradually reduced and/or finally discontinued in most patients if they constantly adhere to the diet. The immunological reactions may also be reduced. The gluten-free diet could thus be successful both concerning manifestations from the skin and the gut. Although well known in dermatological literature, diet therapy in DH has attracted little interest in journals of nutrition. A survey of this causal diet therapy for the disease therefore seems appropriate.

Dapsone↗

A 30-residue-long "export initiation domain" adjacent to the signal sequence is critical for protein translocation across the inner membrane of Escherichia coli.

Signal sequences serve to target proteins to the secretory pathway in both prokaryotic and eukaryotic cells. However, although necessary, the presence of a signal sequence is not always sufficient to ensure efficient membrane translocation. One feature of the nascent chain that adversely affects secretion, at least in Escherichia coli, is the presence of positively charged amino acids immediately downstream of the signal sequence. We have exploited this sensitivity to positively charged residues to demonstrate the presence of a sharply delimited "export initiation domain" that comprises the signal sequence and its approximately 30 downstream residues. A string of six consecutive lysines completely blocks translocation when placed inside this domain but not when placed only a few residues further away.

Amino Acid Sequence↗

The efficiency of the uncleaved secretion signal in the plasminogen activator inhibitor type 2 protein can be enhanced by point mutations that increase its hydrophobicity.

Plasminogen-activator inhibitor type 2 (PAI-2) is a specific inhibitor of plasminogen activators that belongs to the serine protease inhibitor superfamily (SERPINS). PAI-2 exists in two molecular forms: an intracellular, non-glycosylated form and a secreted, glycosylated form. Like ovalbumin, PAI-2 contains an uncleaved internal secretion signal. By deletion analysis, we have mapped the secretion signal to two mildly hydrophobic regions near the NH2 terminus. We also show that both of these regions become more efficient translocation signals when their hydrophobicities are increased. The PAI-2 secretion signal provides a unique example of a signal that, by virtue of its poor efficiency, allows the synthesis of both an extracellular and an intracellular form of the protein.

Amino Acid Sequence↗

Brewer's spent grain, serum lipids and fecal sterol excretion in human subjects with ileostomies.

A crossover design studying lipid and apoprotein levels in serum and excretion of sterol, nitrogen and fat in ileostomy effluent was performed in 10 subjects fed diets with or without supplementation with brewer's spent grain, which is the residue of barley after the brewing of beer. More cholesterol, nitrogen, fat and energy were excreted in the ileostomy effluents when the subjects consumed a brewer's spent grain supplemented, high fiber diet than when they consumed a low fiber diet. No significant change was found in the daily net sterol excretion. The six subjects with low daily excretion of bile acids (less than 1000 mg/24 h) had increased cholesterol and net cholesterol and decreased bile acid excretion per day, and lowered serum LDL-cholesterol and apoprotein B levels after supplementation with brewer's spent grain. We propose that subjects with low daily bile acid excretion are suitable models for studying the effect of dietary changes on sterol excretion and serum lipid levels. Increased fecal cholesterol excretion is suggested to be the primary mechanism for the serum LDL-cholesterol lowering effect of brewer's spent grain.

Adult↗

Culture of renal tubular cells from the urine of patients with nephropathic cystinosis.

Nephropathic cystinosis represents a prototype for lysosomal storage diseases and is the most common cause of renal tubular Fanconi's syndrome. Mechanisms of the tubular transport defects in this disease have not been defined, however, in part because the cells readily cultured from affected patients, leukocytes and fibroblasts, do not express epithelial transport functions. Except for a single autopsy report, renal tubular cells from these patients have not been studied in vitro. In these studies, noninvasive harvesting and culture of renal tubular cells from the urine of patients with cystinosis is described. Cultures of renal tubular cells could be established from over 50% of the isolates which contained viable cells and which remained uncontaminated in vitro. Cells had an epithelial morphology in culture, and the majority of cultured cells expressed proximal tubular brush border marker enzyme. Cultured cells also expressed the storage defect in vitro, containing cystine levels up to 100 times those of normal cells. Cultured cells could be depleted of cystine by using the thiol cysteamine. This in vitro model system should be very useful for studying the mechanisms of renal tubular transport defects in this disease.

Cells, Cultured↗