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Biomedical subjects

K J Ho

Publications and source records attributed to K J Ho.

At least 109 records · Page 6Linked to original sources
PubMed1980

Bile acid pool size in relation to functional status of gallbladder and biliary lipid composition in Chinese.

Bile acid pool size was measured in 10 Chinese without gallstones, 14 with pigment stones, and 10 with mixed stones by an isotope dilutin technique. Functional status of gallbladder was evaluated by intravenous cholecystogram and its gross appearance at surgery. Biliary lipid composition was also determined. The control subjects had a bile acid pool size comparable to that of Caucasians. Regardless of the nature of gallstones, bile acid pools of stone patients with functioning gallbladder were within normal range, whereas the pools of those with non- or poorly-functioning gallbladder diminished to about two-thirds of the control. Thus, the diminution of bile acid pool size was apparently the consquence of loss of storage function of gallbladder rather than the cause of production of lithogenic bile. The common bile duct bile obtained from stone patients with nonfunctioning gallbladder had a relatively high lithogenic index, at least partly related to its low total lipid concentration.

Adult↗
PubMed1980

Determination of urinary beta-glucuronidase activity. Single-point versus enzyme kinetic measuring system.

beta-Glucuronidase activity was determined in dialyzed and undialyzed urine from 50 healthy adult males by single-point and enzyme kinetic measuring systems. The enzyme had a pH optimum of 5.2 and a Michaelis constant of 1.465 +/- 0.206 mmol/l (mean +/- SD) of phenolphthalein glucuronide. Substrate inhibition occurred at a concentration of 0.006 mol/l in one fourth of the urine samples. A significant amount of a competitive inhibitor, D-glucaro-1,4-lactone, was present in one third of the specimens. The activity measured by the single-point determination was always lower than the maximal velocity, particularly in the presence of the competitive inhibitor and substrate inhibition. Such pitfalls could be avoided by the enzyme kinetic method which not only permits the detection of substrate inhibition of the enzyme and the elimination of 2-hour dialysis of urine, but also allows the determination of both the maximal velocity of the enzyme and the quantity of D-glucaro-1,4-lactone in urine.

Glucaric Acid↗
PubMed1979

Primary hemangiopericytoma of lung: radiography and pathology.

Two cases of primary hemangiopericytoma of the lung are reported. The massive tumors had radiographic features of round or oval contour, homogeneous opacity, well circumscribed smooth outline without calcification, and no compression of the surrounding lung tissue. They were rather homogeneous histologically, well encapsulated, and centrally located, but extended peripherally by replacement, instead of compression, of the pulmonary parenchyma. Review of the literature about 34 other cases suggests these are the usual characteristics of primary hemangiopericytomas of the lungs.

Cough↗
PubMed1979

Chronic systemic Dacron and Teflon embolization of a Beall model 103 mitral valve prosthesis.

A case is presented of chronic systemic Dacron and Teflon embolism arising from a Beall Model 103 mitral valve prosthesis installed 11 years earlier. The emboli induced intense foreign body reaction resulting in numerous microgranulomas throughout the body. Multiple microinfarctions in the brain accounted for repeated episodes of transient ischemic attacks. Wearing of the prosthesis with consequent embolic complications seems to be the inevitable terminal fate of such early models of the Beall valve. Regular assessment of the functional status of such prostheses, particularly those in place for more than 5 years, is strongly recommended.

Brain↗
PubMed1979

Characterization and determination of the activity of biliary beta-glucuronidase in rats.

beta-Glucuronidase activity determined in 100 diluted bile samples from 12 rats with bile duct fistula by using phenolphthalein glucuronide as substrate incubated at 56 degrees C and pH 6 was 636 +/- 650 (mean +/- S.D.) modified Sigma units/ml. The enzyme had an optimal pH of 6.0 and was inhibited slightly by cholate by markedly by chenodeoxycholate and deoxycholate. The biliary beta-glucuronidase had, thus, low activity under normal physiologic condition because of the high pH (8.1) and high bile salt content (20 mumoles/ml) of the bile. The enzyme kinetic studies revealed that the direct bilirubin was a competitive inhibitor to phonolphthalein glucuronide for the enzyme. The affinity of the former to the enzyme was 163 times that of the latter. The studies provided a method for measuring the true activity of biliary beta-glucuronidase (Vmax) devoid of interfering factors by measuring the enzyme velocity (v) in the diluted bile with at least five different concentrations of substrate (s). The plotting of (1/v) vs. (1/s) should yield the y intercept or (1/Vmax).

Animals↗
PubMed1979

Circadian rhythm of cholesterol biosynthesis: dietary regulation in the liver and small intestine of hamsters.

Sixty three hamsters were divided into two groups which were exposed to the same rigid lighting schedule (06(00)--18(00)) but fed at different time intervals (18(00)--22(00), and 08(00)--12(00), respectively) for five weeks. The cholesterol synthetic activity was then determined in liver, gastrointestinal tract, and kidney by in vivo incorporation of (1--14C)-acetate into cholesterol at different hours of the day. A remarkable circadian rhythm of the activity was found in the liver and small intestine, but not in other organs. Regardless of the lighting schedule, the nadir occurred, in both groups, always at the end of the fasting period and the peak four to six hours after feeding. The study clearly indicated the major role of diet in regulation of such phenomenon.

Animals↗