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Biomedical subjects

I Huk

Publications and source records attributed to I Huk.

62 records · Page 4Linked to original sources

[Lack of stimulation of nitrogen retention and plasma protein synthesis due to increased intake of branched-chain amino acids].

In a randomised study the influence of 3 different amino acids (AA) solutions on nitrogen balance, plasma protein synthesis, and plasma and urine AA pattern was investigated in postoperative (p.o.) cancer patients. The patients in group I received a balanced AA solution designed especially for p.o. patients with 10 percent branched chain amino acids (BCAA), those in group II a solution with 60 percent BCAA and those in group III a solution with 67 percent alanine. All patients received the same amount of nitrogen (0.16 g/kg BW/day) and energy (2.p.o. day: 80 kJ/kg BW/day; 3.-5. p.o. day: 160 kJ/kg BW/day) with a 3:1 ratio of carbohydrate to fat calories. No difference was observed between the three groups for mean daily nitrogen balances, however, the cumulative nitrogen balance of group I (-4.5 +/- 3.6 g) was significantly (p less than 0.05) improved compared to group II (-12.2 +/- 4.2 g). The p.o. decreased concentrations of short-life plasma proteins (prealbumin, transferrin, retinol-binding protein) increased until the end of the study period without any statistic differences between the three groups. On the 2nd p.o. day especially the gluconeogenetic AA were decreased in all patients, but were nearly normal in all patients on the 5th p.o. day. In conclusion the increased administration of BCAA neither improved nitrogen retention nor plasma protein synthesis and does not seem advantageous in the postoperative total parenteral nutrition.

Aged↗

[Malnutrition and postoperative complication rate in cancer patients (author's transl)].

The nutritional status and skin reactivity of 82 cancer patients were determined before surgery and compared with the postoperative complication rate. The nutritional status of 47 patients was evaluated by weight, height, weight-loss, arm muscle circumference, triceps skin-fold measurements, serum albumin, pre-albumin, retinolbinding protein, tranferrin, and cholinesterase. In 35 patients protein catabolism was assessed by the urea production rate (catabolism greater than 15 g/d). Immunity was assessed by the total lymphocyte count and a skin reactivity test. Using these criteria, 55% of the patients were malnourished. Curative operations could only be carried out in 17.4% of the malnourished, but in 50% of the normally nourished patients (P less than 0.0001). Postoperative complications were increased in malnourished patients (47%) when compared with normally nourished patients (20%, P less than 0.05). In anergic and malnourished cancer patients no curative surgical treatment was possible. Due to the increased postoperative complication rate in malnourished cancer patients, nutritional assessment, including the determination of cellular immunity should be performed after admission.

Body Height↗

[Orthograde intestinal irrigation as a preoperative intestinal preparation. Reduction of the intestinal flora using antibiotics].

Whole gut irrigation is a now a well-established method of preoperative bowel preparation. Additional reduction of bacterial content is desirable. The influence of neomycin/bacitracin and clindamycin as well as the combination, as admixture to the whole gut irrigation, on the flora of the large intestine, was therefore investigated in a prospective controlled study. While neomycin/bacitracin caused only a reduction of aerobic, and clindamycin of the anaerobic bacteriae, the combination resulted in a nearly total eradication of detectable bacterial content at the time of operation.

Anti-Bacterial Agents↗

Development of 'no-reflow' phenomenon in ischemia/reperfusion injury: failure of active vasomotility and not simply passive vasoconstriction.

BACKGROUND/AIM: Local blood flow failure (no-reflow phenomenon) during ischemia/reperfusion (I/R) injury may be mediated by interstitial edema formation (passive vasoconstriction) and/or microvascular spasm (active vasoconstriction). The development of the no-reflow phenomenon in the rabbit hind limb I/R model and the influence of treatment with L-arginine and/or antioxidative vitamins were investigated. METHODS: Untreated rabbits were compared with those treated with L-arginine (4 mg/kg/min) or antioxidative vitamins (0.4 ml/kg) alone or in combination during hind limb I/R (2.5/2 h). Interstitial edema formation and microvessel diameter alterations were measured morphometrically. Capillary blood perfusion was measured continuously with laser Doppler flowmetry. RESULTS: I/R injury was expressed by interstitial edema formation (interstitial space increase by 80%), microvascular constriction (microvessel cross-sectional area decrease by 30%), and development of no-reflow phenomenon (blood flow reduction by 60%). Treatment with antioxidative vitamins alone or L-arginine alone reduced interstitial edema by 22 and 31%, consequently, while combined L-arginine/antioxidative vitamin treatment showed a more pronounced edema reduction by 40%. Treatment with only antioxidative vitamins failed to influence the development of no-reflow, although interstitial edema formation was reduced. L-Arginine treatment alone or in combination with antioxidative vitamins prevented microvascular constriction and preserved blood flow after reperfusion without development of no-reflow despite still apparent interstitial edema. CONCLUSIONS: Affections of active vasomotility and not merely passive changes of external pressure (i.e., interstitial edema formation) should be considered important in the development of microvascular constriction during 'no-reflow' phenomenon.

Animals↗

Positive effect of treatment with synthetic steroid hormone tibolon on intimal hyperplasia and restenosis after experimental endothelial injury of rabbit carotid artery.

BACKGROUND: Arterial intimal hyperplasia and following restenosis may be inhibited by estrogens. We investigated the effect of a synthetic steroid hormone, Tibolon: (a) on intima hyperplasia and restenosis in vivo, and (b) on production of endothelial nitric oxide synthase (eNOS), vascular endothelial growth factor (VEGF), endothelial cell proliferation and apoptosis in vitro. METHODS: Influence of Tibolon treatment (0.1 mg/kg body weight, during 3 days before and 3 weeks after the operation as a drinking solution once daily) on neointimal formation (measured by morphometry) and arterial wall damage (by qualitative histology) were investigated in vivo using an animal model of balloon injury of carotid artery. In human umbilical vein endothelial cells (HUVEC) and human microvascular endothelial cells (HMEC-1), the effect of Tibolon (0.1 microg/ml) on eNOS and VEGF was assessed by ELISA. Cell proliferation was induced by VEGF(165) and measured by BrdU incorporation assay, cell apoptosis was detected colorimetrically measuring DNA fragmentation. RESULTS: Balloon injury resulted in neointima formation and prominent damage of the carotid artery wall. Treatment with Tibolon increased luminal area, decreased intimal area and intima to media ratio, and promoted better reparation of damaged vessel wall. In vitro, Tibolon treatment did not influence the expression of eNOS protein in HUVEC as well as cell proliferation rate but reduced apoptosis of endothelial cells by about 40%. Additionally, this treatment suppressed basal and IL-1beta-stimulated synthesis of VEGF in HMEC-1. CONCLUSIONS: Tibolon treatment suppressed neointimal formation and promoted better reparation of damaged vessel wall in carotid artery after balloon injury. This positive effect seems to be associated with improved endothelial cell survival resulting possibly in increased NO production. It might be also related to the decrease of VEGF generation.

Animals↗

Free amino acids in plasma and muscle in fulminant hepatic coma during an extracorporeal liver perfusion.

A 21-year-old female patient suffering from fulminant hepatic failure was treated with extracorporeal normothermic baboon's liver perfusion for 60 hours. The amino acids (AA) uptake of the extracorporeal organ and the ratio of plasma and muscle AA at the end of the perfusion were measured. The AA uptake of the extracorporeal liver was 414 millimoles per 60 hours and even greater during hemodialysis treatment. In spite of this AA uptake, the plasma AA pattern was not normalized. At the end of the perfusion, the free AA concentration in muscle tissue was 86.25 millimoles per liter of intracellular water, an increase of 62% compared to healthy volunteers. In the patient, the ratio of glutamine to glutamine in muscle tissue was 20 to 1 compared to 5 to 1 in normals. It is concluded that (1) the extracorporeal baboon liver cannot extract the quantities of AA released by endogenous protein catabolism in hepatic failure, and (2) the muscular ammonia detoxification system gets overloaded as indicated by the increase ratio of glutamine to glutamate.

Adult↗

A new method for long-term intravenous alimentation in unrestrained rats.

Existing equipment for long-term iv alimentation in small laboratory animals is somewhat cumbersome and quite costly. Although a one-time expense, the cost of this equipment may not be economically viable for many researchers. Herein we present a novel method for long-term iv alimentation in unrestrained rats that is practical, inexpensive, and easily assembled from readily available materials. This new "proxy" set was tested and compared with the standard swivel assembly set. Statistical analysis showed no difference in measured parameters in rats infused by either method. However, the cost of the new set (excluding pump) was almost 90 times less than its commercially available counterpart. This self-constructed approach should bring small animal research within the economic means of most investigators.

Animals↗