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Biomedical subjects

C T Huang

Publications and source records attributed to C T Huang.

At least 73 records · Page 4Linked to original sources
PubMed1987

Angiotensin I converting enzyme inhibitors containing unnatural alpha-amino acid analogues of phenylalanine.

The activity of three angiotensin I converting enzyme (ACE) inhibitors with unique related structures was assessed in vitro and in vivo. The three compounds were (S)(-)-1,2,3,4-tetrahydro-2-(3-mercapto-1-oxopropyl)-3-isoquinoline carboxylic acid (EU-4865), 1,2,3,4-tetrahydro-2-(3-mercapto-1-oxopropyl)-1- isoquinolinecarboxylic acid (EU-4881), and (S)(-)-1,2,3,4-tetrahydro-1-(3-mercapto-1-oxopropyl)-2- quinolinecarboxylic acid (EU-5031). In vitro EU-4881 was a competitive inhibitor that lacked potency (IC50 = 1980 nM) against purified ACE. The other two compounds were equipotent (IC50 = 41 nM) against purified ACE but differed in their inhibition kinetics. EU-4865 (Ki = 38 nM) was a noncompetitive inhibitor, and EU-5031 (Ki = 6.9 nM) was a competitive inhibitor. Against caveolae membrane-bound ACE EU-4881 also lacked potency (IC50 = 2852 nM). In vivo in the conscious acute aortic coarctate (AAC) rat it also lacked potency, having an ED30 (oral dose decreasing blood pressure 30 mmHg) greater than 100 mg/kg. The activity of EU-4865 and EU-5031 in the caveolae membrane-bound ACE and AAC rat reflected their different Ki values rather than their similar IC50 values. In vitro, EU-4865 and EU-5031 had IC50 values of 19 and 6.7 nM, respectively, and in vivo, they had ED30 values of 52 and 1.1 mg/kg, respectively. These results suggest that ACE has a binding requirement for a carboxy-terminus, hydrophobic amino acid that is important for in vivo activity.

Angiotensin-Converting Enzyme Inhibitors↗
PubMed1987

Roentgenographic patterns of Pneumocystis carinii pneumonia in 104 patients with AIDS.

We reviewed the initial and follow-up chest roentgenograms (CXR) of 104 patients with the acquired immune deficiency syndrome (AIDS) and Pneumocystis carinii pneumonia (PCP) diagnosed between 1981 and 1985 in order to determine the relative frequencies of its various roentgenographic patterns. Although a diffuse bilateral interstitial infiltrate is most common, it was concluded that unusual and atypical roentgenographic manifestations of PCP occur in AIDS. These include localized infiltrate, cystic or honeycomb lesions, hilar enlargement and spontaneous pneumothorax.

Acquired Immunodeficiency Syndrome↗
PubMed1987

Pleural cryptococcosis in the acquired immune deficiency syndrome.

Pleural cryptococcosis is extremely rare. We report the first case of cryptococcal pleural effusion in association with the acquired immune deficiency syndrome. Pleural effusion without the evidence of pulmonary parenchymal involvement was the initial and only clinical finding leading to the diagnosis of disseminated cryptococcosis. The pleural effusion resolved spontaneously prior to amphotericin B therapy.

Acquired Immunodeficiency Syndrome↗
PubMed1987

Pneumatocele formation in adult pneumonia.

Pneumatocele formation is unusual in adult pneumonia, particularly in pneumococcal pneumonia. We report three cases of pneumatocele formation in adults, including one with probable pneumococcal pneumonia. All three patients were severely ill and two expired. Although they are usually asymptomatic, pneumatoceles may enlarge and compress the adjacent lung and mediastinum. This occurred in two patients causing respiratory insufficiency and cardiovascular compromise. The placement of a chest tube into the enlarging pneumatocele resulted in successful decompression.

Adult↗
PubMed1987

Disseminated histoplasmosis in the acquired immunodeficiency syndrome. Report of five cases from a nonendemic area.

Disseminated histoplasmosis is predominantly a disease of the immunocompromised. However, it has been reported infrequently in patients with the acquired immunodeficiency syndrome (AIDS), and then almost exclusively from patients residing in endemic areas. We report five cases of disseminated histoplasmosis in patients with AIDS in a nonendemic area. The initial diagnosis was made by fiberoptic bronchoscopy in three patients and by bone marrow and liver biopsy specimens in one patient each. All patients had fungemia, septic shock, and multiple organ involvement. Three patients had a fulminant course and died within four weeks. Two patients had more prolonged courses, with one survival period of ten months. We conclude that patients with AIDS are at high risk to contract disseminated histoplasmosis with an extremely high morbidity and mortality. This risk is not limited to residents of endemic areas.

Acquired Immunodeficiency Syndrome↗
PubMed1986

Year-to-year changes in effective renal plasma flow in asymptomatic spinal cord injury patients.

Year-to-year variations in effective renal plasma flow (ERPF) measurements were determined in 78 patients with spinal cord injury who had no urologic complications or surgery or bouts of chills and fever between consecutive annual follow-up examinations. The effects of age, gender, level and degree of lesion, and time since injury on the degree of variability were also determined. None of the factors considered had a statistically significant effect (P greater than 0.05) on year-to-year variations in ERPF. About 90 per cent of the individual kidney ERPF measurements were within 100 ml/min of the measurement made in the previous year, and 90 per cent of the total ERPF measurements were within 175 ml/min of the previous year's measurement. Follow-up of patients whose year-to-year variability exceeded these limits showed that most subsequently regressed toward the mean spontaneously. These data suggest that kidney blood flow varies considerably from year to year in otherwise healthy patients with spinal cord injury and that changes of 100 ml/min or more for an individual kidney or 175 ml/min or more for both kidneys together are common, but probably of little clinical significance, provided the absolute levels of ERPF remain within normal limits.

Adult↗
PubMed1985

Correlation between anti-hypertensive activity in rats and plasma angiotensin I-converting enzyme (ACE) inhibition in mice following oral administration of ACE inhibitors.

Thirty-four ACE inhibitors were evaluated to determine the concentration giving 50% inhibition of purified rabbit lung ACE (IC50 microM) using benzyloxycarboxyl-p-NO2-Phe-His-Leu as substrate, to determine the oral dose causing a lowering in blood pressure of 30 mm Hg (ED30 mumol/kg) in acute aortic coarctate (AAC) rats, and to determine inhibition of plasma ACE (PACE) activity in mice after oral dosing. Mouse PACE activity was determined with 14C-Hip-His-Leu as substrate one hour after oral dosing of 3 animals/group with 5 or 50 mumol ACE inhibitor per kg. Data from mice were expressed as percent of control group PACE activity. Least squares regression analysis showed the IC50 data to be poorly correlated with either rat data or mouse PACE data at 50 mumol/kg p.o. However, correlation was significant between log rat ED30 and mouse PACE at 5 (p less than 0.001, r = 0.570) and 50 (p less than 0.025, r = 0.387) mumol/kg p.o. Thus, the simple mouse plasma ACE determination after a dose of 5 mumol/kg is a convenient supplement to the AAC rat model for showing oral activity of ACE inhibitors.

Angiotensin-Converting Enzyme Inhibitors↗
PubMed1985

Effective renal plasma flow: clinical significance after spinal cord injury.

We conducted a study to determine if effective renal plasma flow routinely measured by hippurate clearance during a comprehensive renal scintillation procedure is a relevant measure for assessing renal function in spinal cord injury patients. All subjects had spinal cord injury and had had contemporaneous comprehensive renal scintillation procedures and excretory urograms on 2 occasions 24 months or less apart. Each of the 469 kidneys was placed into 1 of 5 quintiles on the basis of its effective renal plasma flow at the first examination. The percentage of the kidneys that had clinically significant pyelocaliectasis or in which the pyelocaliectasis significantly worsened was 20.4 per cent in the lowest (first) quintile and 9.3, 2.2, 5.4 and 3.2 per cent in the second, third, fourth and fifth quintiles, respectively. Analogous data for ureterectasis were 16.1, 8.2, 2.2, 3.3 and 3.2 per cent. There was a significant (p less than 0.01) correlation between effective renal plasma flow and renal parenchymal thickness. Kidneys with renal calculi averaged effective renal plasma flows about 25 per cent lower than those of kidneys free of calculi. We conclude that effective renal plasma flow is a relevant measure for assessing renal function in spinal cord injury patients.

Acute Disease↗
PubMed1985

Granulomatous inflammation in the acquired immune deficiency syndrome.

Granulomas were found in 16 biopsied specimens from eight patients with the acquired immune deficiency syndrome (AIDS), a disease characterized by a profound suppression of the T-cell arm of immunity. The pathogens were Mycobacterium avium-intracellulare (1), Mycobacterium tuberculosis (3), Histoplasma capsulatum (2), Candida albicans (1), and unidentified in one patient. The sites of granuloma formation included the lung in two, the pleura in one, the liver in three, the bone marrow in six, the skin in one, and the lymph node in three cases. The granulomas were epithelioid in nature, with aggregates of epithelioid histiocytes and macrophages. They were by and large small and loosely formed, with minimal or absent lymphocytic cuffing. Although it is a well-recognized concept that T-cell and macrophage interaction plays an important role in the granulomatous inflammatory response, granulomas have been produced in experimental animals independent of cell-mediated immune mechanisms. Granuloma formation in AIDS patients may well represent a clinical example of such a phenomenon.

Acquired Immunodeficiency Syndrome↗
PubMed1985

Free fatty acids in the development of breast milk jaundice.

The incubation of milk, at 4 degrees C, from mothers of infants with breast milk jaundice (BMJ) is reported to result in significantly higher levels of free fatty acids (FFA) compared with milk from controls. Single milk samples collected under standard conditions were obtained from four mothers of infants with BMJ and 14 control donors matched for stage of lactation. Milk samples were analyzed for the concentrations of FFA, using thin-layer gas chromatographic techniques. In addition, serum total fatty acids were measured in mothers and infants. The concentrations of FFA increased after storage of the milk from both the jaundiced and control groups. No differences were observed in the composition of milk FFA before or after incubation, when respective values were compared between these two groups. Similarly, no differences were detected in serum total fatty acids in either infants or mothers. The observation that increased levels of FFA in milk are associated with BMJ was not confirmed.

Adult↗
PubMed1984

Lowering of blood pressure in chronic aortic coarctate hypertensive rats with anti-digoxin antiserum.

A marked lowering of arterial blood pressure was observed in chronic aortic coarctate (CAC) hypertensive rats after intravenous administration of anti-digoxin antiserum. The hypotensive effect lasted for about 30 min after dosing. In contrast to the pronounced changes observed following treatment with anti-digoxin antiserum in CAC rats, only a transient pressor effect was observed in both water- and saline-drinking CAC rats following injection of normal goat serum. In addition, a transient depressor effect was observed in normotensive rats after injection of anti-digoxin antiserum. The results of this study provide additional evidence indicating that an endogenous digoxin-like substance may play an important role in the maintenance of chronic low-renin hypertension induced by aortic coarctation.

Animals↗
PubMed1983

Enamel demineralization tests with some standard foods and candies.

To indicate the cariogenic potential of some standard foods and confections, their ability to demineralize powdered enamel or enamel sections was tested by incubation with mouth organisms in saliva or plaque. With a few exceptions, the amounts of demineralization produced by the tested substrates in either a closed or flowing system fell within relatively narrow ranges.

Candy↗