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Biomedical subjects

C H Ho

Publications and source records attributed to C H Ho.

At least 55 records · Page 3Linked to original sources
PubMed1998

Relating cocaine blood concentrations to toxicity--an autopsy study of 99 cases.

UNLABELLED: We conducted a retrospective study of 48 men with cocaine-related deaths (CTOX), and a control group of 51 male cocaine users who died of lethal trauma (TRAU). Regression analysis and multiple t-tests were used to assess the relationship between cocaine and benzoylecgonire concentrations as well as autopsy measurements. FINDINGS: Mean age was similar (35.9 vs 34.8 years, p = .549). Cocaine blood concentrations were not significantly different (1.12 vs .487 mg/L, p = .10), but mean BE concentrations were higher in CTOX (1.54 vs .946 mg/L, p = .018). CTOX decedents had a lower Body Mass Index (BMI) (24.6 vs 30.6, p = < .0001), larger hearts (426 vs 369, p = .009), and heavier lungs, livers, and spleens (1275 g vs 1007 g, p = .009, 1896 g vs 1628 g, p = .008, 193 g vs 146 g, p = .001). CONCLUSIONS: (1) Blood cocaine concentrations in cocaine-related deaths are indistinguishable from postmortem concentrations in recreational users, but BE is higher in cocaine-related deaths. (2) Increased lung, liver and spleen weights are consistent with cocaine induced heart failure, but (3) Decreased BMI and increased heart weights in CTOX must be a consequence of long term cocaine use. Cardiac alterations may explain why equal blood cocaine concentrations may be lethal in some cases and innocuous in others, (4) Isolated measurements of postmortem cocaine and BE blood concentrations cannot be used to assess, or predict toxicity.

Adult↗
PubMed1998

Can advanced hemostatic parameters detect disseminated intravascular coagulation more accurately in patients with cirrhosis of the liver?

BACKGROUND: Laboratory diagnosis of disseminated intravascular coagulation (DIC) is difficult in patients with cirrhosis of the liver due to the complicated hemostatic changes of DIC. More recently, newer molecular hemostatic markers have been used to improve the diagnosis of DIC. This study evaluated the ability of the more advanced hemostatic tests to diagnose DIC in patients with cirrhosis of the liver. METHODS: A series of hemostatic tests and parameters including activated partial thromboplastin time (APTT), prothrombin time (PT), thrombin time (TT), factor VIII assay, antithrombin (AT) activity, fibrinogen, plasminogen, protamine sulfate test (PST), fibrin (ogen) degradation product (FDP), D-dimer, thrombin-antithrombin complex (TAT) (measured by modified antithrombin, ATM), euglobulin lysis test (ELT) and platelet count were performed in 51 patients with cirrhosis of the liver. A diagnosis of DIC was made according to the following parameters and criteria: a) platelets less than 80 x 10(9)/l; b) PT greater than 1.5, c) APTT greater than 1.3; d) TT greater than 24 sec; e) AT less than 60%; f) ATM greater than 14.7 ng/ml (normal, mean +/- 3 SD); g) fibrinogen less than 1.50 g/l; h) positive PST; i) D-dimer greater than 1.0 microgram/ml; j) FDP greater than 20 micrograms/ml; k) ELT less than 150 min; l) plasminogen less than 50%. DIC was diagnosed if six or more of the above items were present, and at least two of them were item (a) to (h), and at least two were item (g) to (l). RESULTS: Although eight patients had results that fitted the diagnostic criteria of DIC by using the more advanced tests, only two of them were diagnosed with DIC by conventional testing. The concentration of factor VIII in these eight patients did not markedly decrease. CONCLUSIONS: New tests are not necessary to improve the diagnosis of DIC in patients with cirrhosis of the liver.

Adult↗
PubMed1998

Immunoglobulin D multiple myeloma: a case report.

Immunoglobulin D (IgD) multiple myeloma is a rare disorder with a poor prognosis. We herein report a case of IgD myeloma presenting with renal failure and bicytopenia. A bone marrow biopsy specimen showed infiltration of homogeneous plasma cells, which stained positively for IgD and light chains. We review the literature and discuss the clinical manifestations, diagnosis and treatment strategy for this rare tumor.

Adult↗
PubMed1997

Prevalence of activated protein C resistance in the Chinese population.

In 1996, a total of 1700 subjects, including 461 healthy subjects and 1239 clinic patients, were randomized and consecutively entered into our study. Their mean age was 49.30+/-18.71 years, range 1-99 years. Of them, 1117 were male, and 583 were female. The mean age of the male was 42.96+/-17.64 years, and of the female, 52.60+/-18.41 years. The mean activated protein C ratio in 1700 subjects was 2.96+/-0.69, range 2.00-7.93. None of them had activated protein C ratio <2.0. The mean activated protein C ratio in the male was 2.81+/-0.63, and in the female was 3.04+/-0.71. None of the subjects was found to have activated protein C resistance. DNA analysis for the Arg 506-Gln mutation was also performed on 492 out of the 1700 subjects; none of them had this mutation. We suggested that the Chinese is not a race with the trait of activated protein C resistance.

Adolescent↗
PubMed1997

Primary transplantation of allogeneic peripheral blood stem cell for severe aplastic anemia.

Primary allogeneic peripheral blood stem cell transplantation (allo-PBSCT) has not been previously described in the treatment of severe aplastic anemia (SAA). We report a patient with SAA who underwent primary allo-PBSCT with cells from her HLA-identical sibling and achieved rapid bone marrow reconstitution. The patient has been in complete remission with normal blood counts for 9 months following allo-PBSCT. This suggests that primary allo-PBSCT is a safe and effective alternative in the treatment of SAA.

Adolescent↗
PubMed1997

Two tandemly repeated telomere-associated sequences in Nicotiana plumbaginifolia.

Two tandemly repeated telomere-associated sequences, NP3R and NP4R, have been isolated from Nicotiana plumbaginifolia. The length of a repeating unit for NP3R and NP4R is 165 and 180 nucleotides respectively. The abundance of NP3R, NP4R and telomeric repeats is, respectively, 8.4 x 10(4), 6 x 10(3) and 1.5 x 10(6) copies per haploid genome of N. plumbaginifolia. Fluorescence in situ hybridization revealed that NP3R is located at the ends and/or in interstitial regions of all 10 chromosomes and NP4R on the terminal regions of three chromosomes in the haploid genome of N. plumbaginifolia. Sequence homology search revealed that not only are NP3R and NP4R homologous to HRS60 and GRS, respectively, two tandem repeats isolated from N. tabacum, but that NP3R and NP4R are also related to each other, suggesting that they originated from a common ancestral sequence. The role of these repeated sequences in chromosome healing is discussed based on the observation that two to three copies of a telomere-similar sequence were present in each repeating unit of NP3R and NP4R.

Base Sequence↗
PubMed1997

The effect of transfusion on cardiac function in patients with chronic anemia.

BACKGROUND: The deteriorating cardiac function of patients with chronic anemia may be improved with transfusion. The effect of transfusion on cardiac function was evaluated in patients with chronic anemia. STUDY DESIGN AND METHODS: In a prospective study, ejection fraction (EF) was determined before and after transfusion in 41 patients with chronic anemia. The results were compared and analyzed. RESULTS: The volume of red cells transfused and the levels of pretransfusion hemoglobin, hematocrit, and red cell, white cell, and platelet counts did not affect the posttransfusion EF, whereas the pretransfusion EF of the right or left ventricle inversely affected the posttransfusion change in EF in the respective ventricle (p < 0.001 and r = -0.5022; p = 0.01 and -0.3917, respectively). There was no significant difference in the change in EF in the right and left ventricles. CONCLUSION: Transfusion produced little immediate effect on cardiac function, but did change the EF to an extent that aided cardiac function in chronic anemia patients. The pretransfusion EF itself, but not the degree of anemia or volume of red cells transfused, affected the posttransfusion change in EF.

Adult↗
PubMed1997

Fibroblasts contracting collagen matrices form transient plasma membrane passages through which the cells take up fluorescein isothiocyanate-dextran and Ca2+.

When fibroblasts contract collagen matrices, the cells activate a Ca(2+)-dependent cyclic AMP signaling pathway. We have found that contraction also stimulates uptake of fluorescein isothiocyanate-dextran molecules from the medium. Our results indicate that fluorescein isothiocyanate-dextran enters directly into the cell cytoplasm through 3- to 5-nm plasma membrane passages. These passages, which reseal in less than 5 s in the presence of divalent cations, also are likely sites of Ca2+ uptake during contraction and the first step in contraction-activated cyclic AMP signaling. The formation of plasma membrane passages during fibroblast contraction may reflect a general cellular response to rapid mechanical changes.

Binding Sites↗
PubMed1997

Leiomyosarcoma of the left atrium: a case report.

Primary malignant cardiac tumors are uncommon, and cardiac leiomyosarcoma is extremely rare. We reported a case of left atrial (LA) leiomyosarcoma with unusual clinical manifestations. A 28-year-old female presented with unknown cause of fever, body weight loss and anemia for two months. Echocardiography and magnetic resonance image study disclosed a 5 x 3 x 3.6 cm3 lobulated mass in the LA with invasion to its posterior wall. Histologic and immuno-histochemical studies of the resected specimen revealed a picture of leiomyosarcoma. The patient improved after surgical resection and post-operative chemotherapy. The literature was reviewed with a discussion of the clinical manifestations, diagnosis and treatment strategy of this rare tumor. Diagnosis of LA leiomyosarcoma is frequently delayed to make a very poor prognosis. Postoperative chemotherapy should be considered because of highly possible incomplete resection. However, an optimal treatment regimen remains unknown.

Adult↗
PubMed1996

Lymphocyte beta2-adrenergic receptors and plasma catecholamine levels in lead-exposed workers.

The effect of lead exposure on beta2-adrenoceptor density and catecholamine response was studied in 26 male workers and 1 female worker, exposed to lead on average for 6 years. The systolic blood pressure in lead workers (101-160 mmHg, 124.4 +/- 14.7 mmHg) was found to be significantly higher than in controls (97-134 mmHg, 115.4 +/- 10.4 mmHg, p < 0.01) as was plasma norepinephrine (0.51 +/- 0.1 microg/liter vs 0.24 +/- 0.05 microg/liter, p < 0.01). The density of lymphocyte beta2-adrenergic receptors (Bmax) in lead-exposed workers was 86% lower than that in controls (0.15 +/- 0.08 vs 1.08 +/- 0.29 fmol/0.1 x 10(6) cells; p < 0.01). The dissociation constants (Kd) of [125I]iodocyanopindolol were 93.6 +/- 42.6 and 87.9 +/- 42.7 pM in lead-exposed workers and controls, respectively. Multiple linear regression analysis showed that elevation of systolic pressure was closely related to (a) blood lead levels, (b) decreased beta2-adrenergic receptor density, and (c) increased plasma catecholamine levels in lead-exposed workers. Linear regression analysis revealed that both plasma norepinephrine levels and beta2-adrenoceptor density (Bmax) were highly correlated with both systolic blood pressures and blood lead levels in lead-exposed workers, and a highly significant negative correlation was found to exist between Bmax and plasma norepinephrine levels (r = -0.82, p < 0.001). These data therefore demonstrate that there is a close relationship between elevated plasma catecholamine levels, decreased beta2-adrenergic receptors, and elevated blood pressure in lead-exposed workers.

Adult↗
PubMed1996

Field intubation of trauma patients: complications, indications, and outcomes.

Neither the success nor the complication rate for field intubation of trauma patients is known with any certainty. A retrospective audit of 94 severely injured patients who required field intubation was undertaken. Fifty percent (13 of 26) of survivors and 67% (37 of 71) of nonsurvivors were successfully intubated in the field (not significant). Mechanism of injury was similar in both groups, but survivors were younger (27 v 60 years, P= .049) and less critically injured, as reflected by their Injury Severity Scale scores, their Trauma Scores, and their field Glasgow Coma Scale scores (22.1 v 30.8, P = .0035; 7.7 v 4.2, P < .0002; and 6.3 v 3.3, P < .0001). When compared with previously published studies of medical patients with cardiac arrest, the success rate was lower in our trauma patients. When compared with patients having similar injuries intubated at the trauma center, field intubation was three times more likely to be associated with the development of nosocomial pneumonia than was hospital intubation.

Emergency Medical Services↗
PubMed1996

Efficacy of the antimicrobial compound U-82,127 as a growth promoter for growing-finishing pigs.

The antimicrobial compound U-82,127 (Pharmacia & Upjohn, Kalamazoo, MI) is a thiopeptide that belongs to a series of cyclic peptide antibiotics produced by Streptomyces arginensis. It is active mainly against Gram-positive organisms. A study involving 576 growing-finishing pigs was conducted at six locations to assess the efficacy of the growth-promoting compound from approximately 19 to 89 kg BW. The basal diet was an unmedicated corn-soybean meal diet fortified with vitamins and trace minerals and containing 16% CP (.80% lysine) during the growing stage (to 54 kg) followed by 13% CP (.60% lysine) during the finishing stage. Dietary dose concentrations of the antimicrobial compound were 0, 3.3, 6.6, and 9.9 mg/kg. At each location, there were six replications of four pigs (two barrows and two gilts) per pen. Diets and water were available for ad libitum consumption. The antimicrobial was provided in coded bags, and investigators were blind to the treatments. The ADG during the growing stage was improved by all levels of the antimicrobial (P < .04), but only the 6.6 mg/kg level improved ADG during the finishing stage (P < .03). Feed:gain was improved by all concentrations of the antibiotic (P < .01) during the growing stage and by the two lower levels of the drug (P < .06) during the finishing stage. Over the entire study, the antimicrobial compound improved ADG (linear, P < .06) and feed:gain (quadratic, P < .01; minimum feed:gain was at 6.2 mg/kg). The lowest dose with a 90% confidence interval of its predicted value not overlapping with the predicted value of the control was 2.3 mg/kg; thus, the efficacious dose range for improving feed/gain was between 2.3 and 6.2 mg/ kg. Neither death loss nor pig removal from the experiment was affected by treatment. The results indicate that the antimicrobial compound U-82,127 is an effective growth-promoting agent for growing-finishing pigs.

Animals↗
PubMed1996

Production of hematopoietic regulatory cytokines by 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 determine their effect on normal bone marrow (BM) colony growth. Thirty-five patients with AA and 21 normal controls were enrolled in the study. Medium conditioned by PBMNC of AA patients in the presence of phytohemagglutinin (PHA) was found to be suppressive to the clonal growth of normal BM cells. Thus, we further determined the presence in the PBMNC conditioned medium (CM) of inhibitory cytokines (macrophage inflammatory protein-1 alpha [MIP-1 alpha], transforming growth factor-beta 2 [TGF-beta 2], interferon-gamma [IFN-gamma], and tumor necrosis factor-alpha [TNF-alpha]) and stimulatory cytokines (granulocyte-macrophage colony-stimulatory factor [GM-CSF], interleukin-3 [IL-3], and stem cell factor [SCF]). The results show no significant difference between AA patients and normal controls in the spontaneous production of all cytokines by PBMNC. After PHA stimulation, the production of MIP-1 alpha, IFN-gamma, TNF-alpha, and GM-CSF significantly increased in the cultures of AA patients (p = 0.0009, 0.0002, 0.0022, and 0.0156, respectively). However, both TGF-beta 2 and SCF were undetectable in most of the tested samples. IL-3 was measured in the conditioned medium only after PHA stimulation, but without significant difference between the two groups (p = 0.67). Furthermore, the myelopoietic suppressing effect of AA-PBMNC CM could be significantly blocked by pretreatment with specific antibodies to the corresponding inhibitory cytokines (MIP-1 alpha, IFN-gamma, and TNF-alpha). After antibody neutralization, an apparent change occurred in the clonal growth of normal BM cells incubated with AA-PBMNC CM, resulting in colony enhancement of 205, 131, and 237% by anti-MIP-1 alpha, anti-IFN-gamma, and anti-TNF-alpha, respectively. These results suggest that overproduction of inhibitory cytokines, rather than underproduction of stimulating cytokines, may play a role in the progression of at least some patients with AA.

Anemia, Aplastic↗
PubMed1996

Effects of colony-stimulating factors on the all-trans retinoic acid-induced differentiation of acute promyelocytic leukemic cells.

BACKGROUND: NB4, a cell line derived from a patient with t(15;17) acute promyelocytic leukemia (APL) that undergoes granulocytic differentiation when treated with pharmacological doses of all-trans retinoic acid (ATRA), was used as a model for induction of differentiation. In this study, we examined the interaction of colony-stimulating factors (CSF) and ATRA in affecting the proliferation and differentiation of NB4 cells. METHODS: Nitroblue tetrazolium (NBT) reduction was used as a functional marker of leukemia cell differentiation. The number of viable cells was counted by trypan blue exclusion test. RESULTS: Proliferation of NB4 cells increased when exposed to 10(-9)M of ATRA, but reduced progressively when exposed to ATRA at the concentrations of 10(-8)M to 10(-6)M. After culture for 5 days, NBT-positive cell was not detectable in the control cultures with medium alone, but its percentage apparently increased to 84% at 10(-7)M ATRA. Granulocyte (G)-CSF per se had no effect on the granulocytic differentiation of NB4 cells, but it could enhance the NBT reduction when used in combination with various concentrations (10(-9)M -10(-6)M) of ATRA. Interleukin (IL)-3 or granulocyte-macrophage-CSF (GM-CSF) alone also had no effect on the NBT reduction in NB4 cells. However, when combined with ATRA, both caused a slight suppression of NBT reduction. No synergistic effect was noted between IL-3 and G-CSF on the ATRA-induced granulocytic differentiation. CONCLUSIONS: G-CSF, but not IL-3 or GM-CSF, can enhance the differentiating activity of ATRA. Further investigations are necessary to evaluate its clinical use.

Cell Differentiation↗
PubMed1995

Non-muscle myosin II heavy chain has a cryptic cell-adhesion domain.

We have discovered a cryptic cell-adhesion domain in non-muscle myosin II heavy chain. A 205 kDa cell-adhesion-promoting polypeptide (p205) was extracted from BHK cells by Nonidet P-40 or Dounce homogenization. Adhesion to p205 was specifically inhibited by the peptide Gly-Arg-Gly-Asp-Ser-Pro, indicating a role for the Arg-Gly-Asp cell-adhesion motif. Purified p205 was identified as non-muscle myosin II heavy chain, based on sequence analysis and on the cross-reactivity of p205 with anti-(bovine trachea myosin) antibodies. Further experiments showed that the heavy chain of purified myosin II has cell-adhesion-promoting activity in a cell-blotting assay, and cross-reacted with anti-p205 antibodies. Finally, the adhesion domain was located in the tail portion of myosin II heavy chain, where an Arg-Gly-Asp-containing sequence can be found.

Amino Acid Sequence↗
PubMed1995

The influence of age and smoking on hemostatic parameters in the chinese people.

Plasma plasminogen activator inhibitor-1 (PAI) antigen, fibrinogen, factor VII, cholesterol, triglyceride (TG) and glucose were determined in 101 healthy subjects, who were divided into 10 subgroups according to age and smoking status. Factor VII and cholesterol were significantly higher in 50 healthy smokers than in the remaining 51 healthy non-smokers (p = 0.037 and 0.008, respectively). By dividing smokers and non-smokers each into 5 different age groups, we found that smoking could significantly increase PAI and/or factor VII, but not fibrinogen, in several age groups. On the other hand, age would significantly increase fibrinogen in either smokers or non-smokers, and this increase would be promoted by smoking. In conclusion, smoking could produce higher factor VII or PAI, whereas age could effect the significant increase of fibrinogen which was further promoted by smoking. Though aging cannot be avoided, smoking should be abstained especially in the old people to prevent the occurrence of thromboembolic diseases.

Adult↗