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Biomedical subjects

H Koh

Publications and source records attributed to H Koh.

At least 73 records · Page 4Linked to original sources
PubMed1991

Molecular properties of global suppressors of temperature-sensitive folding mutations in P22 tailspike endorhamnosidase.

Two global suppressors (Val-331 greater than Ala and Ala-334 greater than Val) have been identified for temperature-sensitive folding (tsf) mutations in gene 9 of bacteriophage P22 (Mitraki, A., Fane, B., Haase-Pettingell, C., Sturtevant, J., and King, J. (1991) Science 253, 54-58). We have introduced 19 different single amino acid substitutions at the two global suppressor sites independently and examined the effects on the tailspike formation in Escherichia coli. Folding and maturation patterns of the various substitutions at the two global suppressor sites in the wild-type background suggest that Val-331 is located on the protein surface and Ala-334 is in the hydrophobic region. In combination with a tsf mutation, tsfH304 (Gly-244 greater than Arg), only Gly at 331 and Ile at 334, the substitutions that have similar side chain properties to the original suppressor sequences, were active as tsf suppressors. The newly identified suppressors of tsfH304 could also alleviate the tsf defect of three other mutations. The mutant carrying both Val-331 greater than Ala and Ala-334 greater than Val substitutions was also a global suppressor and was more active in suppressing the tsf defect than mutants carrying only one substitution. The suppressors may act by increasing the stability of an intermediate in the productive pathway of folding and maturation of the mutant polypeptides.

Amino Acids↗
PubMed1991

[Fontan type procedure in patient with borderline hemodynamics: using a temporary R-L shunt in early postoperative period].

Fontan type procedure was successfully performed to a 14-year-old patient with borderline hemodynamics using a temporary R-L shunt in early post operative period. Preoperative diagnosis was DORV (ILD), small RV, PS, ASD, juxtaposition of atrial appendages and post bilateral B-T shunts. Preoperative catheterization studies showed low PARI but insufficient pulmonary arterial size (PA-index 220). In the Fontan procedure, RA was partitioned obliquely with a composite patch of xenograft and Dacron velour. A 5.5 mm hole was created only in xenograft to allow a temporary R-L shunt. During rewarming period, systemic pressure hovering around 60 mmHg with 10 micrograms/kg/min of dopamine and dobutamine. Then a R-L shunt was created by a side to side anastomosis between the appendages with the orifice diameter of 10 mm, followed by a rise in the systemic pressure up to about 80 mmHg. One post operative day, a readjustable occluder was applied at the site of appendage anastomosis to control R-L shunt flow. According as CVP decreased, the occluder was tightened up step by step. Finally, the occluder was fully tightened up in 10 post operative days. This experience suggests that a temporary R-L shunt in early post operative period may be applicable in patient with borderline hemodynamics for Fontan type procedure.

Adolescent↗
PubMed1991

[Clinical study on total intravenous anesthesia with droperidol, fentanyl and ketamine--10. Effects of prostaglandin E1 on the hepatic and renal functions following prolonged surgery under total intravenous anesthesia].

Twenty one patients who underwent prolonged surgical procedures over 10 hours under total intravenous anesthesia with droperidol, fentanyl and ketamine were studied to evaluate post-operative hepatic and renal functions as judged by serum levels of GOT, GPT, BUN and creatinine. They were divided into two groups. Ten patients of the PGE1 group were given PGE1 at a rate of 0.035 micrograms.kg-1.min-1 during anesthesia, and the remaining eleven of the control group were not given PGE1. The two groups were comparable concerning, age, body weight, height, operation time and anesthesia time. In the PGE1 group, significantly more intraoperative fluid was given than in the control group. The blood loss was more but insignificantly in the PGE1 group than in the control group. There was no significant difference in urine output and the amount of blood transfused between the two groups. In both groups, post-operative s-GOT and s-GPT levels were increased significantly compared with pre-operative values, but there was no significant difference between the two groups. Serum BUN levels of the 7-10 the post-operative days were increased significantly in the PGE1 group, but those of the control group were not. These data suggest that our method of total intravenous anesthesia with droperidol, fentanyl and ketamine, when applied even for prolonged surgical procedure over 10 hours, would have beneficial effects on the post-operative hepatic and renal functions.

Alprostadil↗
PubMed1991

[Clinical study on total intravenous anesthesia with droperidol, fentanyl and ketamine--9. Control of intraoperative hypertension with diltiazem].

Intraoperative hypertension over 160 mmHg systolic and sinus tachycardia over 100 bpm are often observed during total intravenous anesthesia with droperidol, fentanyl and ketamine. Fifty-seven surgical patients who developed hypertension over 160 mmHg systolic during various operative procedures under this type of anesthesia were given diltiazem intravenously to overcome the situation. Their blood pressure and heart rate decreased soon after the administration of diltiazem. The rate pressure product was reduced significantly. Neither preoperative hypertension nor difference of doses between 5 mg and 10 mg of diltiazem had any significant relationship with hypotensive effect of intravenous diltiazem. But the higher the systolic-pressure was just before the administration of diltiazem, the more effective diltiazem was. No adverse effects with this drug was observed. We can conclude that intravenous diltiazem in a dose of 5 mg or 10 mg may be repeatedly given to overcome hypertension or sinus tachycardia during this type of anesthesia without any adverse effects.

Anesthesia, Intravenous↗
PubMed1991

[Clinical study on total intravenous anesthesia with droperidol, fentanyl and ketamine--4. Control of intraoperative hypertension with nicardipine].

Intraoperative hypertension over 160 mmHg systolic observed during total intravenous anesthesia with droperidol, fentanyl and ketamine was treated with intravenous nicardipine in 50 surgical patients. Nicardipine was given intravenously in a bolus of either 0.5 mg or 1.0 mg to treat the intraoperative hypertension. Systolic and diastolic blood pressures decreased soon after administration of nicardipine without simultaneous sinus tachycardia. Thus rate pressure product was also reduced significantly. Neither preoperative hypertension, nor systolic blood pressure just before the administration of nicardipine had any significant relationship with hypotensive effect of intravenous nicardipine. We did not experience any adverse reaction with the drug. We conclude that intravenous nicardipine in a dose of 0.5-1.0mg can be given repeatedly to overcome hypertension observed during this method of anesthesia.

Adolescent↗
PubMed1991

[Clinical study on total intravenous anesthesia with droperidol, fentanyl and ketamine--5. An anesthetic experience of a pediatric patient with severe epilepsy].

A 6-year-old girl with severe epilepsy received an orthopedic surgery of the right hand under new total intravenous anesthesia with droperidol, fentanyl and ketamine. For the induction of anesthesia, droperidol 0.25 mg.kg-1, fentanyl 5.0 micrograms.kg-1 and ketamine 2.0 mg.kg-1 was administered intravenously. She was intubated and ventilated manually throughout the operative procedure to maintain the end tidal CO2 between 4.5 and 5.5%. For the maintenance of anesthesia, ketamine was given continuously at a rate of 2.0 mg.kg-1.hr-1. Intraoperative muscle relaxation was obtained with vecuronium bromide. The patient recovered from anesthesia uneventfully. The total doses of droperidol, fentanyl, ketamine and vecuronium were 8.75 mg, 1.0 mg, 210 mg and 7.5 mg, respectively. Neither epileptic seizure, nor any other adverse effects with anesthetics was observed during and after anesthesia and surgery. We conclude that this method of anesthesia for epileptic patients may deserve further detailed study.

Anesthesia, Intravenous↗
PubMed1990

Relationships between serum cholesterol and obesity: a field study on nutritional background of hypercholesterolemia.

1. Serum cholesterol levels in Japan were unrelated to total fat intake and its quality. 2. A significant positive correlation was found between serum cholesterol level and BMI, and the total energy intake was significantly higher in hypercholesterolemic group than in normocholesterolemic group. 3. Hypercholesterolemia seems to occur in the background of accumulation of body fat due to relative excess of energy intake in Japan.

Adult↗
PubMed1988

Effect of high salt intake on sodium, potassium-dependent adenosine triphosphatase activity in the erythrocytes of normotensive men.

1. We measured ouabain-insensitive adenosine triphosphatase (ATPase), sodium, potassium-dependent adenosine triphosphatase (Na+,K+-ATPase) and intracellular Na+ and K+ in the erythrocytes of 19 healthy volunteers, before and after supplementation of their normal diet was 6.0-8.9 g of salt (102-137 mmol of NaCl) per day, for 5 days. 2. The subjects had a small but significant gain in weight. Mean plasma renin activity decreased from 1.57 to 0.73 pmol of angiotensin 1 h-1 ml-1 and plasma aldosterone from 0.46 to 0.24 nmol/l. 3. Total ATPase activity fell from 197.9 nmol of inorganic phosphate h-1 mg-1 during the control period to 173.5 during the high-salt period (P less than 0.0125). Na+, K+-ATPase activity fell from 162.2 to 141.4 nmol of inorganic phosphate h-1 mg-1 (P less than 0.05). Intracellular Na+ and intracellular K+ did not change. 4. These results are consistent with the hypothesis that salt-induced volume expansion causes the release of a factor inhibitory to the Na+ pump.

Adult↗
PubMed1988

Insulin modulates early-phase noradrenaline response to glucose ingestion in humans.

To clarify the relationship between the early-phase insulin response and the early-phase noradrenaline (NA) response to glucose ingestion in humans, serum NA, adrenaline, immunoreactive insulin (IRI), C-peptide immunoreactivity, potassium, nonesterified fatty acid and plasma glucose levels were measured in 8 non-diabetics and 10 diabetics without autonomic disturbance after oral 75 g glucose load. Following results were obtained: 1) In non-diabetics, the maximal NA response was observed at 30 min after glucose ingestion, but in diabetics, mean serum NA levels remained unchanged. The effect of glucose ingestion on the NA response was significantly different between non-diabetics and diabetics by the repeated measurements analysis of variance (F ratio = 5.72, P less than 0.05). 2) In total group (n = 18), at early-phase after glucose ingestion (at 30 min), positive correlation was found between dIRI level and dNA level (r = 0.52, P less than 0.05), between dIRI level and %dNA level (r = 0.56, P less than 0.05), between dIRI/dglucose ratio (insulinogenic index) and dNA level (r = 0.70, P less than 0.01). 3) In four diabetics, NA responses to glucose ingestion were studied again after mild energy restriction for 2 wk. In three of them, both early-phase IRI response and early-phase NA response to glucose ingestion improved after diet therapy, but in the remainder, early-phase NA response to glucose ingestion remained unchanged in accordance with sustained impaired early-phase insulin response to glucose ingestion.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1988

Exercise-induced increase in glandular kallikrein activity in human plasma and its significance in peripheral glucose metabolism.

Glucose uptake into skeletal muscle of human forearm at rest and during exercise is reported to be diminished by the administration of a kallikrein (kallidinogenase) inhibitor. The present study was conducted to clarify the changes of glandular kallikrein (GK) activity in human plasma during acute exercise and its significance in peripheral glucose metabolism. 10 non-diabetic inpatients, aged 49.5 years, and 8 diabetic inpatients, aged 53.8 years, were studied. After an overnight fast, bicycle ergometer exercise test was performed for 15 min (25 W (5 min)----50 W (5 min)----75 W (5 min]. Before (basal), during (at 15 min) and after exercise (at 25 min), venous blood samples were drawn to determine plasma GK activity and glucose, serum immunoreactive insulin (IRI), C-peptide immunoreactivity (CPR), nonesterified fatty acids, pyruvate, lactate, noradrenaline and adrenaline levels. In the 1st trial, in both non-diabetics (n = 10) and diabetics (n = 8), plasma GK activity increased significantly during exercise. After the 1st trial, in 6 patients (5 non-diabetics; 1 diabetic), exercise test was repeated once after 2-4 weeks and in a diabetic patient, exercise test was repeated twice at 4-week intervals, accordingly exercise test was performed 26 times in 18 patients in total. Natural logarithmic correlation between sigma glucose level and sigma GK activity (r = 0.52, n = 26), and hyperbolic correlation between sigma glucose level and sigma IRI level (r = -0.66, n = 26) but no correlation between sigma glucose level and sigma CPR level (r = 0.17, n = 26) were found.(ABSTRACT TRUNCATED AT 250 WORDS)

Blood Glucose↗
PubMed1987

CA125 serum levels and secondary laparotomy in epithelial ovarian tumours.

CA125 serum levels were assayed prior to 57 secondary laparotomies for ovarian epithelial tumours. Tumour was present in all 16 patients with an elevated level greater than 35 U/ml but the absence of tumour was incorrectly predicted in 15 of the 33 (45.5%) patients with CA125 levels less than 35 U/ml. For these patients the CA125 level was elevated in 14 of 20 (70%) with tumour greater than 1.5 cm, 1 of 7 (14.3%) with macroscopic tumour less than or equal to 1.5 cm and 1 of 4 (25%) with microscopic tumour. Tumour was resectable to less than or equal to 0.5 cm in 7 of 12 (58.3%) patients with CA125 less than 35 U/ml, 2 of 4 (50%) with CA125 in the range 35-100 U/ml and only 1 of 11 (9.1%) with CA125 greater than 100 U/ml (p less than .05). The CA125 level was elevated in 1 of 13 (7.7%) patients with less than 15 cm3 of tumour compared with 16 of 18 (88.9%) patients with 15 cm3 of tumour or more (p less than .0001). The correlation between the CA125 serum level and the tumour volume was almost statistically significant (r = +0.31, p = .053). The level of CA125 was normal in all 8 patients with mucinous tumours--4 of whom were found to have tumour at secondary surgery.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1987

Relationship between protein intake and nitrogen balance in obese patients on low energy diet.

The effect of nitrogen intake on nitrogen balance was studied in six obese patients receiving low energy diets. They were given a control diet containing 2,000 kcal of energy and 80 g of protein for the first ten days. Then they were given Diet A with 1,100 kcal of energy and 70 g of protein for the next 2 weeks, followed by Diet B with 1,100 kcal of energy and 50 g of protein for 2 weeks. The relationship between nitrogen intake (X, mg/kg) and nitrogen balance (Y, mg/kg) during the low energy diet periods was statistically significant, with Y = 0.388X-60.32 (SD = 17.71, r = +0.67, n = 11, p less than 0.05). The nitrogen and protein requirements were estimated from this equation to be 201.1 mg/kg and 1.26 g/kg, respectively. In our experiment, the nitrogen balance in obese patients was well maintained although total energy was reduced to 1,100 kcal/day in Diet A. It is suggested that protein quantity in the diets should be taken into account when a low energy diet is used for the treatment of obesity.

Blood Proteins↗
PubMed1987

Effects of low energy diets on protein metabolism studies with [15N]glycine in obese patients.

The effects of low energy diets on protein metabolism in terms of the metabolic pool, active protein pool, and active and inactive protein synthesis rates were studied using [15N]glycine in five obese patients (percentage of ideal body weight, 120-190%). For 10 days, the patients were given a control diet containing 2,000 kcal of energy and 80 g of protein. For the next 2 weeks, they were given Diet A with 1,100 kcal of energy and 70 g of protein, and for the last 2 weeks given Diet B with 1,100 kcal of energy and 50 g of protein. During the Diet A period, the active protein pool and the active and inactive protein synthesis rates were about the same as during the control diet period, although the metabolic pool tended to be slightly smaller than during the control diet period. During the Diet B period, the metabolic pool, active protein pool, and active protein synthesis rate were all significantly different from the values during the control diet period. The results suggest that protein metabolism in obese patients is not maintained with less than 70 g of protein daily when energy intake was restricted to 1,100 kcal/day.

Body Weight↗
PubMed1986

Hormonal regulation of glandular kallikrein activity and its inhibitor in human plasma.

Plasma glandular kallikrein (GK) activity, serum 3,5,3'-triiodothyronine (T3), thyroxine (T4), reverse T3, thyroid-stimulating hormone, plasma alpha 2 macroglobulin (alpha 2M) and alpha 1 antitrypsin (alpha 1AT) levels were determined in twenty-nine non-diabetic female subjects given normal ad-lib diet or one of several kinds of caloric composition for more than 7 days after an overnight fast. Positive exponential correlation was found between serum T3 level and plasma GK activity (r = 0.54), and there was positive linear correlation between serum T3 level and plasma 2M level (r = 0.51). Positive natural logarithmic correlation was found between plasma GK activity and plasma alpha 2M level (r = 0.47). There was no correlation between plasma GK activity and plasma alpha 1AT level, and between serum T3 level and plasma alpha 1AT level. No correlation was found between serum T4 level and plasma GK activity, and between serum T4 level and plasma alpha 2M level. There was no correlation between serum T4 and T3 level, but positive exponential correlation was found between serum T4 and reverse T3 level (r = 0.82). These data suggest that T3 responds to dietary carbohydrate through Kallikrein-Kinin system, and T3 regulates both GK activity and its inhibitor (alpha 2M) in human plasma.

Diet↗