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Biomedical subjects

C H Ho

Publications and source records attributed to C H Ho.

At least 73 records · Page 4Linked to original sources
PubMed1995

The influence of high fat diet on the fibrinolytic activity.

High fat diet containing 50% fat was given to 28 Chinese healthy volunteers for 3 days. Their mean age was 28.04 years with SD 5.53. Blood glucose, cholesterol, triglyceride (TG) and venous occlusion test (VOT) were determined before and after diet. Tissue plasminogen activator (tPA) and plasminogen activator inhibitor (PAI) were determined before and after VOT. After high-fat diet, blood glucose and cholesterol increased significantly (p = 0.031, 0.049 respectively), but other parameters did not. TPA increased significantly after VOT either before or after high-fat diet, but such increment was significantly less after high-fat diet (P < 0.05). In conclusion, the immediate effect of short-term high-fat diet included increased plasma levels of glucose and cholesterol, and impaired fibrinolytic response in stress condition.

Adult↗
PubMed1995

Effect of lymphocytes on the production of granulomonopoietic enhancing factor by fully mature macrophages.

The granulomonopoietic enhancing factor (GM-EF) is a novel myelopoietic regulator produced by human monocyte-derived lipid-containing macrophages (MDLMs). In the present study, we examined the effect of lymphocytes on GM-EF production by preincubation of MDLMs with various preparations of lymphocyte subpopulations in cell-mixed and in double agar layer cultures. Our results showed that a cell concentration-dependent suppression of GM-EF production was noted in cultures with mitogen-activated T cells, and mitogen-activated/resting B cells, while those containing resting T cells had no such effect. Thus, GM-EF production in the presence of 1 x 10(5)/ml activated T cells or activated/resting B cells was greatly reduced to 5% or 20%, respectively. The lymphocyte-induced suppression was evident in both cell-mixed and double layer cultures, implying that the effector cells might exert their influences via mediators. Assay for cytokine activity revealed that a high level (648.2-685.2 pg/ml) of tumor necrosis factor-alpha (TNF-alpha) was found in MDLM cultures with resting/activated B cells, and in those with activated T cells high levels of both TNF-alpha (510.5 pg/ml) and interferon-gamma (IFN-gamma) (321.3 pg/ml) could be detected, whereas in cultures with MDLMs and/or resting T cells, these cytokines were not measurable. Treatment of MDLMs with either recombinant (r) TNF-alpha or rIFN-gamma invariably resulted in a dose-dependent decrease in GM-EF production with intense suppression at doses between 400-800 U/ml.(ABSTRACT TRUNCATED AT 250 WORDS)

B-Lymphocytes↗
PubMed1995

Overproduction of inhibitory hematopoietic cytokines by lipopolysaccharide-activated peripheral blood mononuclear cells in patients with aplastic anemia.

The aim of this study was to measure the level of cytokines produced by peripheral blood mononuclear cells (PBMNC) in patients with aplastic anemia (AA) and to determine their effect on the clonal growth of normal bone marrow (BM) cells. Twenty-one patients with AA and 11 normal controls were enrolled in this study. Medium conditioned by PBMNC of AA patients in the presence of lipopolysaccharide (LPS) was found to be suppressive to the colony growth of normal BM cells. Thus, we further determined the presence in the PBMNC-conditioned medium (CM) of both inhibitory cytokines: macrophage inflammatory protein-1 alpha (MIP-1 alpha), tumor necrosis factor-alpha (TNF-alpha), transforming growth factor-beta 2 (TGF-beta 2), and interferon-gamma (IFN-gamma), and stimulatory cytokines: interleukin-3 (IL-3) and stem cell factor (SCF). Spontaneous production of MIP-1 alpha was higher in the AA patients than the normal controls (1887 +/- 174 pg/ml vs 1643 +/- 93 pg/ml), but the difference was not significant. After LPS stimulation, the production of MIP-1 alpha was markedly increased in the AA patients, and its level was significantly higher than that of the normal controls (2360 +/- 149 pg/ml vs 1517 +/- 92 pg/ml, p = 0.0022). The level of TNF alpha was also higher in the AA patients. However, IFN-gamma, TGF-beta 2, SCF, and IL-3 were not detectable in the PBMNC-CM of either AA patients or normals. The myelopoietic suppressing effect of AA-PBMNC-CM from each AA patient was significantly blocked by pretreatment with anti-TNF-alpha, resulting in a colony-forming enhancement of 174% +/- 12%. A similar effect was noted in six of 11 AA patients by pretreatment with anti-MIP-1 alpha. We conclude that TNF alpha and MIP-1 alpha can be overproduced by the PBMNC of some AA patients, which may play a role in the progression of AA.

Anemia, Aplastic↗
PubMed1995

The influence of time of storage, temperature of storage, platelet number in platelet-rich plasma, packed cell, mean platelet volume, hemoglobin concentration, age, and sex on platelet aggregation test.

The influences of time of storage of platelet-rich plasma (PRP), temperature of storage of PRP, platelet number in PRP, mean platelet volume in whole blood, sex, age, hemoglobin concentration, and different forms of PRP storage on platelet aggregation (PAG) tests, performed with epinephrine, collagen, arachidonate, and ristocetin by a four-channel aggregation profiler (Platelet Aggregation Profiler, Model PAP-4, Bio/Data Corporation, Hatboro, PA 19040, U.S.A.), were evaluated in four groups of subjects (52 men, 22 women, age range 20-85 years, hemoglobin concentration range 8.4-16.8 g/dl). The PRP was stored with or without packed cells, at room temperature or at 4 degrees C, for 0-6 h. The ideal platelet number of PRP for performing the PAG test fell between 150 and 500 x 10(9)/l. If the number was less than 150 x 10(9)/l, the result of PAG should be meaningless. No significant change was noted for up to 6 h when the PRP was stored either at room temperature or at 4 degrees C. Hemoglobin concentration and mean platelet volume did not affect the PAG. However, there was significant but weak correlation (p = 0.0125, r = 0.3696) between age and PAG when using arachidonic acid as the agonist. Men had significantly increased PAG when collagen and ristocetin were used as the agonists. The PRP was stored best at room temperature, without packed cells. In conclusion, to obtain the best result from a PAG test, the PRP should be kept without packed cells at room temperature for no longer than 6 h, and the platelet number should fall between 150 and 500 x 10(9)/l.

Adolescent↗
PubMed1995

Fluorescence assay for measuring lipid deposits on contact lens surfaces.

A simple fluorescence assay for estimating the propensity of the contact lens surface towards the uptake of lipids and formation of lipid deposits has been developed. The assay is based on the incubation of the contact lenses with an artificial tear-lipid mixture, staining of the lenses with a fluorescent lipid probe, Nile Red, and subsequent macroscopic imaging of the fluorescent lipid deposits on the contact lens surface with a thermoelectrically cooled charge-coupled device (CCD) camera. The results of the assay show that statistically significant differences in the formation of lipid deposits exist between the surfaces of different contact lens materials.

Computer Simulation↗
PubMed1995

Hemostatic risk factors of coronary artery disease in the Chinese.

In order to find out the hemostatic risk factors of coronary artery disease in the Chinese, antithrombin III concentration, factor VII and fibrinogen assays, plasminogen activator inhibitor-1 antigen and platelet count were determined in 51 healthy controls (mean age 63.5 years, S.D. 10.3), 55 diabetics (mean age 66.0 years, S.D. 4.8) and 56 patients with arteriographically proved coronary artery disease (mean age 63.8 years, S.D. 8.7). Of the coronary artery disease group, 19 had single vessel disease, 21 had double vessel disease and 16 had triple vessel disease. Sixteen of this group also had a past history of myocardial infarction. There was no significant difference of the hemostasis parameters between diabetics and controls. Fibrinogen and factor VII, but not plasminogen activator inhibitor, were significantly higher in coronary artery disease patients than in controls (P = 0.0001, both) and in diabetics (P = 0.0001, both). No significant difference in the parameters was found in the coronary artery disease group, whether the patients had single vessel disease, double vessel disease, or triple vessel disease, or were with or without past myocardial infarction. In the myocardial infarction group, fibrinogen and factor VII were significantly higher than in the controls (P < 0.00005 and 0.0001, respectively) and in the diabetics (P = 0.0002 and 0.0004, respectively). We suggest that increased levels of fibrinogen and factor VII, but not plasminogen activator inhibitor, would be the hemostatic risk factors of coronary artery disease in the Chinese.

Adult↗
PubMed1995

Surgical delays and outcomes in patients treated with pneumatic antishock garments: a population-based study.

Until mid-1991, our emergency medical services (EMS) system required the routine application of pneumatic antishock garments (PASGs) in all trauma cases, and inflation of the garment if the patient was hypotensive (systolic blood pressure < 90 mm Hg). The findings in 398 trauma patients who underwent emergency surgery when PASG was still being routinely applied were compared with the findings in 590 trauma patients who underwent emergency surgery after routine PASG application had been discontinued. Since the discontinuation of routine PASG application, scene time intervals for "intermediate" blunt and penetrating trauma activations have not changed, but scene times for "full-activation" blunt trauma have actually increased (6.4 minutes with PASG and 9.5 minutes without PASG, P = .0004). Transport times were found to be a function of the type of trauma; patients with penetrating injuries were transported more rapidly (P < .0001) than patients with blunt trauma, even after controlling for injury severity and point of origin. Total time elapsed from EMS activation to the start of surgery for "full" activations, both blunt and penetrating, was unchanged (52.8 minutes with PASG and 53.8 minutes without PASG for penetrating trauma, 117.9 minutes with PASG and 105.1 minutes without PASG for blunt trauma). Times for "intermediate" activations did not change significantly. Length of intensive care unit (ICU) stay did not change. Within the subgroup of patients with femoral but not pelvic fractures, time spent at the scene of injury was shorter for patients treated with PASG than for those treated without (9.5 minutes v 14.5 minutes, P = .0066). Predicted and actual mortality rates were unchanged.(ABSTRACT TRUNCATED AT 250 WORDS)

Cohort Studies↗
PubMed1995

Post-remission intensive consolidation with high-dose cytarabine-based chemotherapy and granulocyte colony-stimulatory factor in adults with acute myelogenous leukemia: a preliminary report.

BACKGROUND: Modern induction chemotherapy produce 60% to 80% complete remission in adults with newly diagnosed acute myelogenous leukemia (AML). A major challenge is to eradicate subclinical disease in remission and prevent leukemic relapse. Intensive post-remission chemotherapy was proved of comparable disease-free survival as BMT. METHODS: From February 1992 to to March 1995, twelve patients with AML, aged 15 to 57 y/o, received intensive consolidation chemotherapy immediately after the first complete remission. The chemotherapy included either 4 courses of high dose Arac (HiDAC), 3 gm/m2 q12h x3 days, or 2 courses of HiDAC (4 days) plus mitoxantrone for 3 days and etoposide for 7 days (HiDAC-3-7). Granulocyte colony-stimulating factor (G-CSF) used used 24 hours after chemotherapy until absolute neutrophile count greater than 500/mm3. RESULTS: Totally 24 courses of high dose chemotherapy were given. The median duration of severe neutropenia (absolute neutrophile count < or = 500/mm3) was 12 days, thrombocytopenia (< or = 50,000/mm3) 18 days, fever > or = 38 degrees C 6 days, and from severe neutropenia (absolute neutrophile count < or = 500/mm3) was 12 days, thrombocytopenia (< or = 50,000/mm3) 18 days, fever > or = 38 degrees C 6 days, and from severe neutropenia (< or = 500/mm3) to infection 4 days. Infection was the most frequent complication during HiDAC treatment. No toxic death was noted. After a median follow-up of 16 months, early relapse was noted in 3 patients (2, 4, and 5 months, respectively), and late relapse in two patients (11 and 20 months, respectively). Seven patients remained in complete remission status after a median follow-up of 14+ months (7+ to 37+ months). CONCLUSIONS: Intensive consolidation chemotherapy is well tolerable and may prolong remission duration when used in the early post-remission phase of AML.

Adolescent↗
PubMed1994

Do smoking and diabetes change the hemostatic parameters?--a study in the Chinese people.

Plasma plasminogen activator inhibitor-1 (PAI) antigen, fibrinogen, antithrombin III (ATIII), protein C, beta-thromboglobulin (BTG), platelet count, fibrinogen degradation product (FDP) D-dimer, factors VII and XII, as well as cholesterol, triglyceride (TG) and glucose were determined in 163 subjects. First we compared the difference of these parameters between 50 diabetics (Group D, mean age 64.9 years) and 50 age-matched healthy controls (Group C, mean age 63.1 years). Nineteen of the diabetics and 19 of the healthy controls were smokers. Plasma glucose, cholesterol, TG and protein C were significantly higher in Group D than in Group C (p = 0.0010, 0.0308, 0.0083 and 0.0068, respectively), whereas ATIII and factor XII were significantly lower in Group D (p = 0.0213 and 0.0061). Secondly, we divided 113 healthy controls (Group C, including Group C plus 63 subjects at various ages) into smokers (mean age 56.7 years) and non-smokers (mean age 40.0 years) and compared the difference between them. Fibrinogen and glucose were higher in the smokers than in the non-smokers (p = 0.0139 and 0.0402, respectively). Other parameters were not different. In conclusion, our study did not find any important hypercoagulation state in the diabetics. Smoking can only increase fibrinogen and glucose without the change of other hemostatic parameters.

Adult↗
PubMed1994

Joint-derived T cells in rheumatoid arthritis react with self-immunoglobulin heavy chains or immunoglobulin-binding proteins that copurify with immunoglobulin.

Rheumatoid arthritis patients were found to have CD4+ T cells that proliferate in response to autologous synovial fluid and plasma. T cell clones and polyclonal T cell lines were found to respond to antigen(s) eluted from protein A Sepharose and anti-human immunoglobulin (Ig) antibody Sepharose. The antigen(s) was further resolved to fractions that contained intact Ig or Ig heavy chain since the T cells responded to > 100 kDa and 40-60 kDa polypeptides derived from purified Ig under nonreducing and reducing conditions, respectively. These results indicated that the antigen(s) is either Ig heavy chain or Ig-binding proteins that copurify with Ig and Ig subunits. Pepsin and papain digestion of the antigenic fractions eluted from protein A destroyed the T cell reactivity. Since most Fab regions are resistant to these enzymes, further analyses are required to localize the antigenic epitope(s). The presence of Ig- or Ig-antigen complex-reactive T cells in arthritic joints implies that B cells expressing anti-Ig antibody (i.e. rheumatoid factor) may play an important role in antigen presentation to autoreactive T cells.

Antibodies, Anti-Idiotypic↗
PubMed1994

Recombinant human granulocyte colony-stimulating factor infusion and/or autologous peripheral blood stem cell transplantation as a rescue for sequential high-dose combination chemotherapy: a preliminary report.

BACKGROUND: Sequential cycles of combination chemotherapy with high-dose cyclophosphamide, etoposide and cisplatin (sHDCEP) can largely increase the total dose (TD) of drug delivered. If granulocyte colony-stimulating factor (G-CSF) and/or autologous peripheral blood stem cell (PBSC) rescue can shorten the duration of cytopenia between cycles of sHDCEP, the dose intensity (DI) can be increased as well. In order to explore the feasibility of delivering maximal TD and DI by administration of sHDCEP with G-CSF and/or PBSC rescue, this trial is undertaken to investigate the hematologic and nonhematologic toxicity observed with sHDCEP by G-CSF and/or PBSC rescue. METHODS: Patients with refractory malignancy and well preserved physiologic function for whom no available therapy is likely to cure or prolong the survival were eligible for the study. Each cycle of high-dose chemotherapy consisted of: cyclophosphamide 5,000 mg/m2, etoposide 1,500 mg/m2 and cisplatin 150 mg/m2. G-CSF and/or PBSC were administered alternatively after each cycle as rescue for myelosuppression. The next cycle was given to patient who showed response to the previous cycle after recovery from toxicity for a maximal of 4 cycles. RESULTS: Two cases of refractory malignancy with progressive disease were treated by sHDCEP for 7 cycles, including 4 cycles with G-CSF rescue, 2 cycle with PBSC rescue, and 1 cycle with G-CSF + PBSC rescue. In the 4 cycles rescued by G-CSF alone, we observed a slightly slower granulocyte and markedly prolonged platelet recovery in the subsequent cycle. By comparing the effect of G-CSF and/or PBSC rescue on hematologic recovery with the preceding cycle in the same patient, we found that G-CSF rescue provided faster granulocyte recovery than PBSC, but PBSC rescue provided faster platelet recovery than G-CSF. Rescue by larger number of PBSCs provided only faster platelet but not granulocyte recovery than rescue by adding G-CSF to a very small number of PBSCs. However, G-CSF plus the very small number of PBSCs provided shorter duration of both granulocytopenia and thrombocytopenia than rescue by G-CSF alone. The most common nonhematologic toxicity from sHDCEP included transient nausea, vomiting, diarrhea and mild impairment of liver function but we observed no significant or irreversible major organ damage. The side effect from PBSC collection was mild and toxicity from reinfusion of the thawed PBSCs was not obvious. Using G-CSF and/or PBSC rescue, sHDCEP was delivered repeatedly in no more than 4 weeks for the next-cycles except for patient 1 who had cycle 4 delayed because of prolonged platelet recovery by only G-CSF rescue in cycle 3. CONCLUSIONS: Our initial experience has shown that the nonhematologic toxicity from sHDCEP, G-CSF and PBSC rescue was well tolerated. Prolonged platelet recovery after sequential cycles of HDCEP by only G-CSF rescue delayed the next cycle of chemotherapy. Although the next cycle was delivered within 4 weeks by only PBSC rescue, concurrent infusion of G-CSF and larger number of PBSCs should provide the most rapid hematologic recovery. Sequential high-dose chemotherapy administered by this model is likely to provide the maximal delivery of TD and DI, and is worthy of further clinical trials.

Adolescent↗
PubMed1993

Relationship of plasminogen activator inhibitor-1 with plasma insulin, glucose, triglyceride and cholesterol in Chinese patients with diabetes.

Plasminogen activator inhibitor-1 (PAI) activity, plasma insulin, glucose, cholesterol and triglyceride (TG) concentrations were determined in 32 Chinese diabetic patients (mean age 61.4 yr) and 41 healthy controls (mean age 64.5 yr) to establish the relationships between these parameters. Insulin, glucose, cholesterol and triglyceride levels were significantly higher in the diabetics, whereas no significant difference of PAI activity was noted between groups. PAI activity was not affected by the increase of plasma insulin, cholesterol, TG or glucose. We have shown that PAI activity in Chinese diabetics was not affected by the common pathologic changes found in diabetes. This might be one of the reasons why fibrinolytic activity is not impaired in Chinese diabetics.

Aged↗
PubMed1993

Influence of vegetarianism on fibrinolytic activity.

Blood glucose, cholesterol and triglyceride levels were determined and the venous occlusion test (VOT) was administered to 15 vegetarians (mean age 46.2 years, SD 15.1) and 20 non-vegetarians (mean age 38.3 years, SD 8.3). The tissue plasminogen activator (tPA), plasminogen activator inhibitor (PAI) and euglobulin lysis time (ELT) were measured before and after VOT. The means of all the parameters were not significantly different between vegetarians and non-vegetarians. TPA increased after VOT in both the vegetarians and the non-vegetarians, but the changing amplitudes of tPA, PAI and ELT induced by VOT were not significantly different in either group. This study evidenced no significant difference in the changes of fibrinolytic activity between vegetarians and non-vegetarians.

Adult↗
PubMed1992

Supercritical fluid extraction of chemical warfare agent simulants from soil.

Chemical warfare agent simulants are efficiently recovered from 2-ppm spikes in 1 g of Rocky Mountain Arsenal Standard Soil using methanol-carbon dioxide (5:95) at 300 atm for 2 min at 60 degrees C. Recoveries (n = 3) were 79 +/- 23% for dimethylmethylphosphonate, 93 +/- 14% for 2-chloroethylethyl sulfide, 92 +/- 13% for diisopropylfluorophosphate and 95 +/- 17% for diisopropylmethylphosphonate. Recoveries are higher than, but less precise than those achieved from a 5-min ultrasonic micro-scale extraction using methanol. Much less laboratory waste is generated than the current standard organic solvent extraction method (33 g of soil shaken with 100 ml of chloroform).

Chemical Warfare Agents↗
PubMed1992

The predictive value of the hemostasis parameters in the development of preeclampsia.

In order to find out which hemostasis parameters would have the predictive value for the development of preeclampsia, modified antithrombin III (ATM, representative of the antithrombin III-serine esterase complex), tissue plasminogen activator (tPA), plasminogen activator inhibitor-1 (PAI-1), beta-thromboglobulin (BTG), antithrombin III (AT III), fibrinogen, fibrin(ogen) degradation product (FDP), FDP D-dimer and euglobulin lysis time (ELT) were measured in 20 normal non-pregnant women, 21 normal pregnant women, 6 high-risk pregnant women, 14 preeclampsia pregnant women, and 5 patients with disseminated intravascular coagulation (DIC). Only tPA and AT III were found significantly different between the preeclampsia and the normal or high-risk pregnant women: tPA was found progressively and significantly increased from the normal pregnant, to the high-risk pregnant, then to the preeclampsia women (p less than 0.05). AT III was significantly lower in the preeclampsia than in the normal pregnant (p = 0.0001) or in the high-risk pregnant women (p = 0.002). In the 2nd trimester, tPA, PAI, fibrinogen and FDP were significantly higher, and AT III was significantly lower in the preeclampsia than in the normal pregnant women, whereas in the 3rd trimester, tPA and AT III were significantly higher or lower, respectively, in the preeclampsia than in the normal pregnant women. No significant difference of ATM could be found between the preeclampsia and the normal or high-risk pregnant women. From the present study, we suggest that tPA and AT III would be used as the main predictors, and FDP and D-dimer as the complementary predictors for the development of preeclampsia and should be detected in the normal or high-risk pregnant women.

Adult↗
PubMed1992

The effects of blood transfusion on serum ferritin, folic acid, and cobalamin levels.

Thirty patients with anemia of various causes received packed red cell transfusions. To evaluate the influence of blood transfusion on the serum levels of different nutrients, serum ferritin, folate, and cobalamin levels were determined before and 2, 2 to 4, 5 to 7, 8 to 10, and 11 to 14 days after blood transfusion. No significant change was found in these levels before or at any time after blood transfusion. Blood transfusion exerted little effect on the serum levels of ferritin, cobalamin, or folate. Moreover, if the blood for testing was drawn 1 to 14 days after transfusion, nearly all cases of nutritional deficiency anemia could have been diagnosed without the influence of blood transfusion.

Adult↗
PubMed1992

Mutagenicity of trinitrotoluene and its metabolites formed during composting.

TNT was mutagenic for Salmonella typhimurium without the need of a rat liver metabolic activation system (S9). The mutagenic potency of TNT decreased in proportion to the number of nitro groups that were reduced to the amino form. The presence of a nitro group on the 4 position of the diamino congener is necessary for mutagenicity. Among the active congeners, mutagenicity was generally greater for TA100 than TA98, except that for the 4-amino congener the reverse was true. In cases when S9 was included in the assay, there was always a decrease in the number of mutants induced as compared with those without S9. Tetryl behaved like TNT, except that it was approximately three times more potent. RDX and HMX were not mutagenic under the conditions of the assay. When TNT was composed, the major metabolites identified in organic extracts of compost samples were the 2-amino and 4-amino congeners. An acetonitrile extract of compost was tested and found to be more mutagenic for TA98 than TA100, much like the authentic 4-amino congener, but the amount of this congener in the extract did not account for the degree of mutagenicity.

Aniline Compounds↗