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Biomedical subjects

C H Ho

Publications and source records attributed to C H Ho.

At least 127 records · Page 7Linked to original sources
PubMed1985

Development of chronic lymphocytic leukaemia in a case of Sjögren's syndrome with systemic lupus erythematosus.

Persistent lymphocytosis and intermittent fever were found in a 68-yr-old Chinese woman 5 yr after the diagnosis of Sjögren's syndrome with systemic lupus erythematosus (SLE). A series of examinations--including virology, bone marrow aspiration and surface markers of lymphocytes--was made to evaluate the nature of the lymphocytosis which had not been found previously. All of the results were consistent with the diagnosis of B-cell chronic lymphocytic leukaemia (CLL). Development of CLL in Sjögren's syndrome has seldom been described before and may be added to other malignancies associated with Sjögren's syndrome.

Aged↗
PubMed1984

The distribution of dermal tumorigens in coal liquids: relationship of tumorigenicity and microbial mutagenicity.

Polycyclic aromatic hydrocarbons and/or their pyrolle derivatives were found to be the primary contributors to the skin tumorigenicity of the neutral fractions of two coal oils. Mutagenicity of the neutral fraction in Salmonella test strains was found to be due primarily to polycyclic aromatics containing polar substituents. Thus, the chemical classes responsible for skin tumorigenicity differ from those responsible for mutagenicity.

Animals↗
PubMed1981

Analytical and biological analysis of test materials from the synthetic fuel technologies.

Nitrogen-containing organic compounds from environmental sources are receiving increasing attention because of uniquely active mutagens which have been found in this class (Chrisp et al., 1978; Nagao and Sugimura, 1978: Guerin et al., 1980) Differences in mutagenic activities among the various organo-nitrogen compounds, i.e., pyrrole types, pyridine types and aniline types, have been noted consistently. Furthermore, differences among homologs of a particular compound type are often striking. Information in this paper engages the question of chemical structure/biological activity relationships. Activity data for several N-heterocyclic, nitro-, amino- (primary, secondary and tertiary), and amino-N-heterocyclic aromatic compounds are presented. The number of fused rings and the substituent type affect the mutagenic activities greatly. The trends observed are discussed generally with reference to molecular structural features.

Cyclic N-Oxides↗
PubMed1978

Analytical and biological analyses of test materials from the synthetic fuel technologies. I. Mutagenicity of crude oils determined by the Salmonella typhimurium/microsomal activation system.

We have assayed the mutagenicity of crude industrial products and effluents with the Salmonella/microsomal activation system. Test materials (crude products from coal-conversion processes and natural crude oils) were initially fractionated into primary classes by liquid--liquid extraction and then further fractionated by column chromatography. Prescreening was accomplished over a wide concentration range with the Ames tester strains. Active fractions (mainly the neutral fractions containing polycyclic aromatic hydrocarbons and certain basic fractions) can be identified, and dose--response relationships can be established. Standard values are expressed as revertants/mg of the test material assayed with frameshift strain TA98 including metabolic activation with rat-liver preparations. Total mutagenic activity of synthetic fuel samples was consistently higher than that of natural crude "controls." Activities of subfractions are roughly additive and presumably reflect the mutagenic potential of the whole test material. These results are being extended to other genetic assays. Chemical identification is carried out along with the bioassays.

Coal↗
PubMedDate not supplied

Human low density lipoprotein and human serum albumin adsorption onto model surfaces studied by total internal reflection fluorescence and scanning force microscopy.

The adsorption of low density lipoprotein (LDL) and human serum albumin (HSA) to model surfaces of different hydrophobicities has been studied using two, surface-sensitive, real-time, in situ techniques: total internal reflection fluorescence (TIRF) and scanning force microscopy (SFM). The model surfaces used were: (1) hydrophilic negatively charged silica (TIRF) and mica (SFM) surfaces, (2) hydrophobic octadecyldimethylsilyl-(ODS)-modified silica (TIRF) and ODS-modified oxidized silicon (SFM) surfaces and (3) amphiphilic ODS-silica gradient surfaces (TIRF). The kinetics of fluorescein isothiocyanate-LDL adsorption onto the ODS-silica gradient surface from FITC-LDL solution and from a solution mixture of LDL and HSA showed that a transport-limited process on the clean silica changed into an adsorption-limited process with increasing surface coverage of ODS chains. SFM analysis of the in situ adsorption of LDL on hydrophilic mica demonstrated a steady increase in surface coverage with time which was somewhat lower than determined by TIRF for FITC-LDL adsorption on silica. The adsorption behavior of a binary mixture of HSA and LDL suggested that lateral interactions between HSA and LDL affect the adsorption process. The diameter of LDL adsorbed on mica and ODS-modified silicon has been determined using SFM to be approximately 55 nm. Tetrameric LDL aggregates were observed on all of the surfaces in addition to some dimers and trimers. Imaging LDL and HSA adsorption on clean oxidized silicon surfaces using "contact mode' SFM techniques was hindered by probe manipulation of the proteins.

Adsorption↗
PubMedDate not supplied

Intensive postremission chemotherapy in Taiwanese adults with acute myelogenous leukemia.

Intensive postremission chemotherapy has produced disease-free survival comparable to that of bone marrow transplantation in patients with acute myelogenous leukemia (AML), but its efficacy was unknown in Taiwan. We assessed the efficacy of intensive postremission chemotherapy, consisting of high-dose arabinoside-C (HiDAC) with or without transplantation of peripheral blood stem cells, in 33 AML patients from a single institute in Taiwan. Toxic reactions, treatment outcome, prognostic factors, and the size of the peripheral blood stem-cell harvest after HiDAC were analyzed. After a median follow-up of 21 months, 18 patients remained in continuous complete remission. The actuarial leukemia-free survival at 4 years was 51%. Relapse occurred in 12 patients, at a median of 12 months after initial diagnosis. All 6 patients with acute promyelocytic leukemia remained disease free after HiDAC therapy. Age, sex, and number of remission-induction or intensive consolidation chemotherapy courses had no effect on the risk of relapse. Intensive postremission chemotherapy can effectively prolong the duration of remission in young (< 60 years of age) adults with AML.

Adolescent↗
PubMedDate not supplied

The hemostatic effect of packed red cell transfusion in patients with anemia.

BACKGROUND: The hemostatic effect of platelets has been well established, but the possible role of red cells in hemostasis has not yet been well studied. An evaluation of the hemostatic effect of packed red cell transfusion in patients with chronic anemia was the purpose of this study. STUDY DESIGN AND METHODS: In a prospective study, bleeding time (BT), activated partial thromboplastin time (APTT), and prothrombin time (PT) were measured before and after the transfusion of allogeneic packed red cells in 42 patients with chronic anemia. The results were compared and analyzed. RESULTS: APTT and BT decreased significantly after transfusion, by a mean of 1.3 seconds (p = 0.01) and 2.6 minutes (p < 0.01), respectively. PT did not change significantly after transfusion (p = 0.65). Factors studied (patient's age, sex, and renal function measurements; pretransfusion and posttransfusion hemoglobin levels, platelet counts, and PTs; change in platelet count [delta platelet count] and PT [delta PT] after transfusion) did not independently affect the change in BT (delta BT) or in APTT (delta APTT). The delta BT was not affected by the pretransfusion or posttransfusion levels of APTT or by the delta APTT. The delta APTT was not affected by the pretransfusion or posttransfusion levels of BT or by the delta BT. Diagnosis of malignant or benign diseases was found to affect delta APTT, but not delta BT. Patients with pretransfusion hemoglobin < or = 60 g per L had a 4.07 times greater chance of posttranfusion increase in BT than the patients with hemoglobin > 60 g per L (p = 0.04). CONCLUSION: Red cell transfusion might decrease the APTT and BT in some anemic patients, though the actual cause of the decrease was not determined in the present study.

Aged↗
PubMedDate not supplied

Effects of hydrotherapy on pressure ulcer healing.

Pressure ulcers are a prevalent and potentially serious medical problem encountered in both the medical and rehabilitation settings. Because the progress of rehabilitation is often interrupted by the presence of pressure ulcers, the efficient care of these wounds is of great interest to the rehabilitation team. Patients in two acute care facilities with Stage III or IV pressure ulcers were identified and consented to participate in the study contained herein. All wounds were mechanically debrided of necrotic tissue, and then the patients were randomly assigned to the conservative treatment group (A; n = 18) or the conservative treatment plus whirlpool group (B; n = 24). Conservative treatment included measures to maximize pressure relief and wound care with wet-to-wet dressings using normal saline. The dressings were changed twice daily and when they became soiled. Whirlpool was administered for 20 min per day in Group B patients. Only those patients whose ulcers were followed-up for 2 or more wk were included in the study. Ulcers were then measured by a physician who was blinded as to the treatment groups. Ulcer dimension changes over time were compared between groups. The results indicate that the conservative treatment plus whirlpool group improved at a significantly faster rate than did the conservative treatment only group (P < 0.05).

Debridement↗
PubMedDate not supplied

A comparative study of cefepime versus ceftazidime as empiric therapy of febrile episodes in neutropenic patients.

An open-label, randomized comparative study was conducted to evaluate the efficacy and safety of cefepime (2.0 g q. 8 h) and ceftazidime (2.0 g q. 8 h) in the empiric therapy of febrile neutropenic patients. A total of 45 eligible febrile episodes were randomized (1:1) to be treated with the study regimen. Nineteen febrile episodes treated with cefepime and 22 febrile episodes treated with ceftazidime were evaluable for efficacy. The two groups were comparable in terms of age, sex, height, weight, underlying neoplasm, number of pretherapy neutrophil, duration of neutropenia and types of infections. The overall therapeutic success rate of the cefepime group (53%) was comparable to the ceftazidime group (50%). It did not differ significantly (95% confidence interval: -0.28 to 0. 34, p = 0.85). Eighty-eight percent of pathogens in each group were bacteriologically eradicated. The safety profile was similar in both groups. No patients in either group discontinued the therapy because of adverse events. None (0%) of the cefepime patients and 2 (9%) of the ceftazidime patients died of infection. The results of this study suggest that cefepime is an effective and safe agent in the empiric therapy of febrile episodes in neutropenic patients.

Adult↗
PubMedDate not supplied

Evaluation of an automatic hematology analyzer in patients with nonhematologic conditions.

The Coulter STKS is a new automated hematology analyzer that provides complete blood counts (CBCs) and a five-part white blood cell (WBC) differential count. This study evaluated its performance and determined its value in reducing the extensive manual work required to obtain WBC differential counts from patients with nonhematologic conditions. The evaluations included precision, carryover, effects of storage duration and temperature, comparison of primary (automated) and secondary (manual) methods of aspiration, comparison with the Technicon H*1 machine, and WBC differential capability. Both primary and secondary methods provided CBC values that were precise, repeatable, and satisfactory. The WBC differential results also were accurate and comparable to those obtained manually. The Coulter STKS not only precisely analyzes CBCs but also screens blood samples without WBC abnormalities, as it has a 98% predictive value of negative test results. This instrument is suitable for use in nonhematology patients in large medical centers, teaching hospitals, and general hospitals.

Automation↗