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Biomedical subjects

K J Ho

Publications and source records attributed to K J Ho.

At least 19 recordsLinked to original sources
PubMed1992

Recurrent meningitis associated with intragastric migration of a ventriculoperitoneal shunt catheter in a patient with normal-pressure hydrocephalus.

A 68-year-old man had ventriculoperitoneal shunt placement for normal-pressure hydrocephalus. Three and a half years later, he had repeated episodes of seizures and ophthalmoplegia. He eventually died of recurrent acute bacterial meningitis. At autopsy the distal segment of the shunt catheter was found inside the stomach, a condition believed to be responsible for the repeated attacks of bacterial meningitis.

Aged↗
PubMed1992

Diverse roentgenographic manifestations of the rare pulmonary involvement in myeloma.

Roentgenographic manifestations of two cases of pulmonary involvement with myeloma were presented. One showed a nodular mass lesion extending from an extramedullary mediastinal plasmacytoma into the lung parenchyma while the other showed diffuse reticulonodular infiltrate by myeloma cells in association with alveolar septal amyloidosis. These two cases demonstrate the extreme variability of pulmonary involvement by myeloma, which can mimic a solitary tumor or an inflammatory infiltrate.

Aged↗
PubMed1992

Development and optimization of an enzyme-linked immunosorbent assay employing two murine monoclonal antibodies for absolute quantitation of human beta-glucuronidase.

We have developed and optimized an enzyme-linked immunosorbent assay (ELISA) for absolute quantitation of human beta-glucuronidase. This is a double antibody sandwich system employing two murine monoclonal antibodies specific for human beta-glucuronidase developed in our laboratories. The method involves (a) coating of the high binding polystyrene microtitration plate with the first antibody (7B6 IgG), (b) blocking of remaining active sites with 3% bovine serum albumin in phosphate-buffered saline, (c) application of samples, (d) addition of the biotinylated second antibody (6D2 IgG), (e) addition of streptavidin-horseradish peroxidase, and (f) development of color with o-phenylenediamine dihydrochloride-H2O2 and reading in a microplate reader at a wavelength of 490 nm. The method is highly sensitive with an optimal range of 10 to 100 ng/ml of the enzyme and is reproducible with intraday and interday precisions of 3.2 and 4.1%, respectively. The enzyme contents of 20 urine and 20 bile samples quantitated by this ELISA method were, respectively, 148 +/- 101 and 6380 +/- 3780 ng/ml (means +/- SD) which correlated well with their enzyme activities. Such a method for absolute quantitation of human beta-glucuronidase is essential for studying its pathophysiologic roles in cholelithiasis and carcinogenesis and can also be used clinically as an indicator for tissue damage or malignancy.

Animals↗
PubMed1992

Radiographic evidence of calcification in pulmonary hamartomas.

Eight cases of solitary intrapulmonary hamartomas are presented to show the unusually high frequency of calcification (75%, six of eight cases) in this series. Possible contributory factors were high percentage of chondromatous variant (seven of eight cases), large size of the tumors, and use of computed tomography.

Aged↗
PubMed1991

Rapid purification of beta-glucuronidase from human liver by immunoaffinity chromatography employing specific murine monoclonal IgG binding to tresyl-activated agarose.

We have developed a simple, rapid method for purification of beta-glucuronidase from human liver in order to facilitate the study of its biochemical structure and pathophysiologic roles in both cholelithiasis and carcinogenesis. The procedure includes the following steps: (1) liver homogenization, (2) 25-45% saturated ammonium sulfate fractionation, (3) heat denaturation, and (4) immunoaffinity chromatography employing murine anti-human beta-glucuronidase monoclonal IgG binding to tresyl-activated agarose. beta-Glucuronidase constitutes 1.3 mg per 100 g of wet liver tissue. The enzyme can be purified with a 10% overall yield and overall purification of 5000-fold in a 2-day cycle on a fairly large scale by the method described. Polyacrylamide gel electrophoresis indicated minor contaminants in the final product which could be further purified by protein blotting.

Ammonium Sulfate↗
PubMed1991

Apical Pneumocystis carinii pneumonia in AIDS patients not receiving inhaled pentamidine prophylaxis.

Isolated apical Pneumocystis carinii pneumonia might develop in AIDS patients receiving aerosolized pentamidine prophylaxis. Demonstrated here are two cases of apical P carinii pneumonia occurring in patients not receiving inhaled pentamidine prophylaxis. Such isolated apical localization of P carinii should be differentiated from tuberculosis and fungal infection.

Acquired Immunodeficiency Syndrome↗
PubMed1991

Unusual initial calcification of primary and metastatic seminomas. Detection by computed tomography.

Rare large ab initio calcifications of a primary mediastinal seminoma in a 16-year-old boy and of para-aortic nodal metastatic ovarian seminoma in a 14-year-old girl are demonstrated with CT but not with conventional radiography. They are most likely dystrophic calcifications because of the absence of other germ cell tumor components and infective granulomatous disease. Routine use of CT might detect more such calcifications in untreated seminoma.

Adolescent↗
PubMed1991

A large-scale purification of beta-glucuronidase from human liver by immunoaffinity chromatography.

We intend to purify beta-glucuronidase from human liver in a large quantity in order to facilitate the study of its biochemical structure and pathophysiologic roles in cholelithiasis and carcinogenesis. The initial purification procedure involved: (1) liver homogenization, (2) 25-45% saturated ammonium sulfate fractionation, (3) heat denaturation of protein at 56 degrees C, (4) gel filtration with Bio-Gel P-300 gel, (5) anion exchange chromatography with DEAE agarose, (6) cation exchange chromatography with CM agarose, and (7) hydroxyapatite chromatography (overall yield, 1%; overall purification, 169X). The final product was used to immunize rabbits and BALB/c mice for production of polyclonal and monoclonal antibodies, respectively. The antibodies, mainly IgG, were purified by using gamma-Protein A agarose column chromatography. The purified IgG, after periodate oxidation, was coupled to hydrazide gel by formation of a stable covalent hydrazone bond linkage. The new purification procedure involved the initial first three steps, followed by (4) polyclonal IgG immunoaffinity chromatography and (5) monoclonal IgG immunoaffinity chromatography (overall yield, 6.1%; overall purification, 3720X). Polyacrylamide gel electrophoresis indicated minor contaminants in the final product which could be further purified by electroelution. It is concluded that beta-glucuronidase constitutes 0.016 mg per gram of wet liver tissue and can be obtained on a large scale in a highly purified form within a 2-day cycle.

Animals↗
PubMed1990

Chinese-white differences in the distribution of occlusive cerebrovascular disease.

The distribution of cerebrovascular lesions is affected by race. Blacks and Japanese have more intracranial occlusive cerebrovascular disease, while whites have more extracranial disease. Despite a high incidence of stroke in China, there are few formal studies of the distribution of vascular occlusive disease in Chinese populations. We compared clinical and angiographic features of 24 white and 24 Chinese patients with symptomatic occlusive cerebrovascular disease. In symptomatic vascular territories, whites had more severe (greater than or equal to 50% stenosis) extracranial lesions, while Chinese had more severe intracranial lesions. When we counted mild and severe lesions in a symptomatic territory, whites had more extracranial lesions while Chinese had more intracranial lesions. When we combined symptomatic and asymptomatic territories, whites had more extracranial lesions, while Chinese had more intracranial lesions. White patients reported more transient ischemic attacks. The distribution of lesions, however, was not explained by differences in incidence of transient ischemia, hypertension, diabetes, hypercholesterolemia, or ischemic heart disease between the groups. The preponderance of intracranial vascular lesions in Chinese patients is similar to that seen in blacks and Japanese. Racial differences in the occurrence of extracranial and intracranial lesions raise the possibility of a different underlying pathophysiology for the 2 locations.

Aged↗
PubMed1990

Biliary D-glucaric acid: its quantitation and preventive role in gallstone formation.

A method for quantitation of D-glucaric acid in bile has been developed involving extraction with tetrahexylammonium chloride, boiling for 40-60 min, and determination of the percentage inhibition of beta-glucuronidase activity at 56 degrees C and pH 4. D-glucaric acid, bilirubin, bile acid, and protein were determined in 106 human gallbladder biles obtained at autopsy, including 20 with gallstones. The mean D-glucaric acid content was 1125 +/- 159 microM (mean +/- SE). Biliary beta-glucuronidase activity was not affected by D-glucaric acid because of 1) no difference in biliary D-glucaric acid content, either absolute or corrected for per unit of bilirubin, bile acid, or protein, between those with and those without gallstones; 2) no negative correlation between D-glucaric acid content and beta-glucuronidase activity in the bile; and 3) minimal conversion of D-glucaric acid to D-glucaro-1,4-lactone at the usual pH of bile. We conclude that biliary D-glucaric acid plays no role in the prevention of gallstone formation.

Bile↗
PubMed1990

Intrapulmonary bronchogenic cyst: spontaneous dissolution?

A well-demarcated, non-calcific, solitary pulmonary nodule was initially discovered 3 v2 years ago on a chest radiograph in a 43-year-old woman with recurrent acute bronchitis. The nodNle had been stationary with minimal change in size until the last radiographic examination which showed total disappearance of the nodule. A thin-walled, air-filled cyst was, however, demonstrated by computed tomography at the same location. The nodule was believed to be an intrapulmonary bronchogenic cyst which developed communication with airway with discharge of its watery content, leading to its pseudo resolution.

Adult↗
PubMed1989

D-glucaro-1,4-lactone: its excretion in the bile and urine and effect on the biliary secretion of beta-glucuronidase after oral administration in rats.

This experiment was designed to test the hypothesis that orally administered D-glucaro-1,4-lactone might be excreted in the bile and thus suppress the activity of biliary beta-glucuronidase, which is believed to play a key role in the development of pigment gallstones. D-Glucaro-1,4-lactone, 50 to 2,600 mu moles, was fed to adult Sprague-Dawley rats which had a bile fistula and were kept in metabolic cages for bile and urine collection. A total of 21 feeding experiments were carried out. Quantitation of D-glucaro-1,4-lactone and total D-glucaric acid as the sum of D-glucaric acid and its lactones in the bile and urine involved extraction of bile with tetrahexylammonium chloride, adjustment of pH, boiling and determination of percentage inhibition of beta-glucuronidase activity. The maximal velocity of beta-glucuronidase in the bile was also determined by the enzyme kinetic method. The results showed that 11% of administered D-glucaro-1,4-lactone was excreted in the urine and only 0.2% in the bile, with D-glucaro-1,4-lactone accounting for 20% of the total excreted D-glucaric acid. The concentration and excretory rate of total D-glucaric acid and D-glucaro-1,4-lactone in the urine, but not in the bile, were proportional to the amount of D-glucaro-1,4-lactone fed. The mean concentration of D-glucaro-1,4-lactone in the bile after feeding was 0.06 mM, which was capable of suppression of 75% of beta-glucuronidase activity. Oral administration of D-glucaro-1,4-lactone decreased biliary beta-glucuronidase concentration, slowed bile flow rate and hence decreased biliary beta-glucuronidase secretion.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Oral↗
PubMed1989

Computed tomography of bronchiectasis in association with tuberculosis.

Eight patients with pulmonary tuberculosis proven by positive sputum culture were found to have various degrees of bronchiectasis by computed tomography (CT) but not by plain chest radiography. The CT is characterized by cystic dilatation of the thick-walled bronchi manifested as strings or clusters of pearls or grapes for cystic bronchiectasis and a "tram-line" appearance for cylindrical bronchiectasis. We stress that bronchiectasis remains quite common in association with pulmonary tuberculosis, and CT can replace bronchography for its detection.

Adult↗
PubMed1989

Pneumocystis carinii pneumonia in an AIDS patient. Unusual manifestation as multiple cavitary and noncavitary peripheral pulmonary nodules and spontaneous pneumothorax.

Pneumocystis carinii pneumonia in a 52-year-old homosexual AIDS patient is described because of its unusual manifestations of multiple cavitary and noncavitary peripheral pulmonary nodules and spontaneous pneumothorax. Such manifestations might become more common in the future because of the improvement of diagnostic techniques and therapeutic measures.

Acquired Immunodeficiency Syndrome↗
PubMed1989

Computed tomographic detection of cavitary lung lesion complicating use of flow-directed balloon-tipped catheter.

A classic case of Swan-Ganz catheter-induced pulmonary infection was studied with both conventional chest radiography and computed tomography (CT). Chest radiography initially showed a fan-shaped opacity in the right middle lobe which later became somewhat rounded with no discernible cavitation. However, a cavitary lung lesion with a bulls-eye appearance was clearly demonstrated by CT. We speculate that such a cavitary lung lesion might be quite common in catheter-induced pulmonary infarction when CT is widely applied to such cases.

Aged↗
PubMed1989

Diffuse fatal pulmonary microembolism of retroperitoneal extravascular origin.

A 34-year-old woman who had type I diabetes mellitus for 22 years and chronic renal failure for 2 years underwent a combined kidney and pancreas transplantation. Her uremia and insulin-dependence disappeared thereafter. However, she suddenly developed acute respiratory distress and died 22 days after the surgery. Diffuse pulmonary microemboli composed of necrotic tissue debris, fat cells, and muscle fragments were found. The source of the emboli was apparently a localized liquefying hematoma with necrotic muscle and fat in the left retroperitoneal space. Although such an occurrence seems to be extremely rare, the present case demonstrates that a liquefying hematoma with necrotic tissue in a confined space may indeed give rise to fatal pulmonary microembolism.

Adult↗