Biomedical subjects

J H Liu

Publications and source records attributed to J H Liu.

At least 109 records · Page 6Linked to original sources

PubMed2000

Ethambutol retinal toxicity: an electrophysiologic study.

BACKGROUND AND PURPOSE: In animal studies, ethambutol (EMB) has been shown to be toxic to cone pedicles and to cause their degeneration in the retinas of fish. The purpose of this study was to determine whether EMB is toxic to retinas in humans. METHODS: Twenty-seven patients with EMB-induced optic neuropathy and 20 normal control subjects were included in this study. The following details were recorded: age, sex, and systemic condition of the patients, daily dosage of EMB, duration of EMB treatment, visual function at the time of electrophysiologic investigation, time from the onset of blurred vision to the discontinuation of EMB treatment (symptom duration), and time from termination of EMB treatment until electrophysiologic investigation. RESULTS: The electroretinograms were normal in 25 patients. Twelve patients had normal electro-oculogram (EOG) findings in both eyes and the remaining 15 patients had abnormal EOG findings in at least one eye. Ten eyes showed supranormal EOG (light/dark (L/D)) ratios of more than 2.33, and 13 eyes had decreased L/D ratios (< 1.65). The symptom duration was shorter in the supranormal EOG group. CONCLUSIONS: The results suggest that a supranormal EOG may be indicative of an early toxic state during EMB therapy and that EMB may cause dysfunction of the retinal pigment epithelium.

Adult↗

PubMed2000

Comparison of the efficacy and safety of oral granisetron plus dexamethasone with intravenous ondansetron plus dexamethasone to control nausea and vomiting induced by moderate/severe emetogenic chemotherapy.

BACKGROUND: Chemotherapy-induced nausea and vomiting can affect cancer patients' compliance with cytotoxic chemotherapy. Currently, there are some new antiemetic therapies for the treatment of chemotherapy-induced emesis. A single institution, randomized, open, parallel trial was done to compare oral granisetron plus intravenous (i.v.) dexamethasone with intravenous ondansetron for the prevention of moderate or severe emetogenic chemotherapy-induced acute and delayed emesis. METHODS: Fifty-one cancer patients were treated with moderate/severe emetogenic chemotherapy and randomized to receive either oral granisetron 1 mg twice daily or i.v. ondansetron 8 mg every 8 hours combined with i.v. dexamethasone 10 mg on the day of chemotherapy. The efficacy and safety of the two antiemetic regimens were compared. RESULTS: Oral granisetron plus i.v. dexamethasone had comparable antiemetic efficacy for the prevention of nausea in the first 24-hour period after initiation of chemotherapy compared with intravenous ondansetron plus i.v. dexamethasone. The complete response of antiemesis in the first 24-hour period after initiation of antiemetic therapy between granisetron and ondansetron were 84.0% (95% CI, 62.9%-95.6%) and 84.6 (95% CI, 64.0%-97.5%). The complete response for delayed emesis after initiation of antiemetic therapy between granisetron and ondansetron were 16.0% (95% CI, 4.5%-36.1%) and 19.2% (95% CI, 6.8%-40.7%0. There was diarrhea in 12% of patients receiving granisetron therapy and constipation in 23.1% of the ondansetron group. CONCLUSIONS: Oral granisetron plus i.v. dexamethasone and i.v. ondansetron plus i.v. dexamethasone are potentially equally effective antiemetic agents in the prevention of moderate or severe emetogenic chemotherapy-induced acute or delayed emesis. Oral granisetron with dexamethasone appears to be a suitable alternative antiemetic agent in cancer patients who receive moderately or severely emetogenic chemotherapy.

Adolescent↗

PubMed2000

Comparative study of timolol gel versus timolol solution for patients with glaucoma.

BACKGROUND: The timolol gel was developed for the simplification of multi-dose medications for glaucoma patients. This gel can be used once per day instead of twice per day of the aqueous form. It is necessary to understand the clinical effects of intraocular pressure maintained in glaucoma by there two forms of timolol. METHODS: Fifty-two eligible patients were included and completed the 12-week study. In this randomized, open-label, two-period crossover study design, patients received either the gel form of 0.5% timolol once daily or the aqueous form of 0.5% timolol twice daily for the first 6 weeks, then crossed over to the other treatment form for the remaining 6 weeks. Intraocular pressure was measured at baseline, week 6 and week 12 at the end of the treatment period. The incidences of all the adverse events were recorded and summarized in each follow-up visit. RESULTS: No statistically significant difference in intraocular pressure was observed between the two different control treatment groups (p>0.05). However, stickiness and transient blurred vision was reported more often by patients using the gel form than the aqueous form of timolol. CONCLUSIONS: The gel form of 0.5% timolol used once daily offers a new alternative that is probably more convenient than the aqueous form of 0.5% timolol given twice daily in maintaining the intraocular pressure of patients with glaucoma.

Adrenergic beta-Antagonists↗

PubMed2000

Pseudophakic Penicillium endophthalmitis.

A healthy 76-year-old woman complained of redness and a painful sensation in her right eye after cataract surgery 5 months previously. The eye was treated with topical corticosteroid and ciprofloxacin, and a soft exudative mass on the nasal lower iris was noted later. Fungal endophthalmitis was suspected and a repeat aqueous culture grew Penicillium spp. After treatment with topical natamycin and an intracameral injection of amphotericin B, the endophthalmitis was cured. We describe the disease course and management and discuss topical corticosteroids as a possible risk factor for increasing the dissemination of Penicillium infection. This was a unique case of successful therapy resulting in the cure of Penicillium endophthalmitis in an immunocompetent patient.

Aged↗

PubMed2000

Immunophenotypic and genotypic characteristics of chronic myelogenous leukemia in blast crisis.

BACKGROUND: Chronic myelogenous leukemia (CML) may transform into blast crisis (BC) if not properly treated. Among patients with transformation, 20% to 30% will develop BC with lymphoid-associated antigens (Ly-BC), and the remaining cases with myeloid-associated antigens (My-BC) or with both (Mix-BC). In this study, we investigated the lineage of blast cells in CML-BC using immunophenotypic and genetic analyses and analyzed the prognostic significance of genotypic change in CML-BC. METHODS: Twenty-one patients with CML-BC diagnosed at the Taipei Veterans General Hospital from 1982 to 1992 were included. Immunophenotyping was done by using the avidin-biotin immunoperoxidase technique. Genetic analyses were carried out by using Southern Blot hybridization. The prognostic influence of genotypic change was analyzed. RESULTS: Thirteen patients (61.9%) expressed myeloid-associated antigens, one patient (4.8%) expressed megakaryoblast-associated antigens, four patients (19%) expressed B lymphoid-associated antigens and three patients (14.3%) expressed both myeloid and B lymphoid antigens. Clonal rearrangement of the immunoglobulin heavy chain (IgH) gene was found in six cases. Among them, four expressed B lymphoid markers only and two expressed both myeloid and B lymphoid markers. Patients with clonal IgH gene rearrangement tended to have a better response to chemotherapy (50% vs 8.3%, p = 0.08) and significantly longer survival (median survival, 5 months vs 3 months, p < 0.05) than did those with a germline configuration. CONCLUSIONS: Clonal rearrangement of the IgH gene was found mostly in cases of Ly-BC and Mix-BC. We found that CML-BC with clonal rearrangement of the IgH gene had a more favorable prognosis than in cases with a germline configuration.

Adolescent↗

PubMed2000

False positive molecular diagnosis of Leber's hereditary optic neuropathy.

BACKGROUND: The most common pathogenic mitochondrial DNA (mtDNA) mutation associated with Leber's hereditary optic neuropathy (LHON) is at the 11,778 nucleotide (nt) position and is usually detected by loss of an Sfa NI restriction site. However, Sfa NI restriction site includes five nucleotides. Substitution of any of the five nucleotides leads to loss of the cutting site and causes a false-positive result. We investigated the false-positive diagnosis of LHON by loss of the Sfa NI restriction site using Sfa NI restriction site analysis and single-strand conformation polymorphism (SSCP) analysis. METHODS: Mae III restriction analysis for double confirmation of the Sfa NI restriction site and direct sequencing for final confirmation of SSCP analysis were performed. RESULTS: The sensitivity of Sfa NI test was 100% and the specificity of the Sfa NI test was 97%. The false-positive rate of Sfa NI test was 3%. SSCP analysis showed 100% sensitivity. Direct sequencing showed 32 patients had a mutation at nt 11,778 of mtDNA and one patient had a silent mutation at nt 11,782 of mtDNA. CONCLUSIONS: These results suggest that restriction enzyme digestion analysis requires double confirmation to avoid a false-positive diagnosis and that DNA sequencing is needed for the confirmation of the mutation detected by SSCP.

Adolescent↗

PubMed2000

Statistics in ophthalmic research: two eyes, one eye or the mean?

BACKGROUND: Ophthalmic data, while different among individuals, are usually similar between fellow eyes of the same individual. This study was designed to illustrate alternative approaches to account for the correlation between fellow eyes. This is important for making inferences using data from both eyes. METHODS: With the use of a real data set from a population-based study, we described the distribution of intraocular pressure (IOP) by estimating the mean and standard deviation (SD) and evaluated the potential risk factors of higher IOP based on the regression method. The units of observation studied were of both eyes, right eye only, left eye only, the eyes with higher IOP and the mean value of both eyes. Furthermore, the generalized estimating equation (GEE) method was used to account for the correlation between fellow eyes in the regression analysis. Results and inferences from the different approaches were compared. RESULTS: The analysis included all the eyes, providing the largest sample size and unbiased estimates of the mean and SDs. There were some discrepancies among different approaches in the regression analysis. The GEE method simultaneously evaluated the effects of both eyes, and increased precision and enhanced inferences. CONCLUSIONS: Inconsistent results among different ophthalmic studies result from variations in not only study design and courses but also statistical methods. Making the best use of appropriate statistical techniques, which account for between eye correlation, provides valid statistical inferences.

Blood Pressure↗

PubMed2000

Probucol inhibits lipid peroxidation of macrophage and affects its secretory properties.

AIM: To investigate the mechanisms of anti-atherogenic actions of probucol. METHODS: Human peripheral blood monocytes were cultured, and treated by copper ion (10 mumol/L) and/or probucol (PBC). Lipid peroxidation was measured by assaying malondialdehyde (MDA). The cytokine interleukin-1 beta (IL-1 beta) and apolipoprotein E (apo E) secreted by monocyte were assayed by enzyme linked immunoassay (ELISA). RESULTS: PBC 10-80 mumol/L inhibited copper ion-induced cellular lipid peroxidation from 15.30 to 7.74 mumol MDA/g cell protein. PBC 40 mumol/L inhibited oxidized macrophage-mediated oxidation of LDL from 5.18 to 1.65 mumol MDA/g cell protein, and attenuated secretory properties of monocytes induced by copper ion. The release of apo E, which is involved in reverse cholesterol transport, increased by 65%. And the release of IL-1 beta, which was shown to enhance vascular smooth muscle cell proliferation, decreased by 45%. CONCLUSION: Probucol inhibits lipid peroxidation of macrophages and affects their secretory properties.

Anticholesteremic Agents↗

PubMed2000

Moclobemide-induced gynecomastia in rats.

AIM: To study the toxic effect of moclobemide on male breast and to elucidate its mechanism of action. METHODS: Routine histopathological analysis was used to diagnose the effect of moclobemide on male breast in rats. Plasma concentrations of estrogen, androgen, and prolactin were measured by a ratioimmunometer and relative receptors of mammary gland tissue were detected immunohistochemically. RESULTS: After 180-d moclobemide treatment, the presence of gynecomastia was 0, 5, 5, 7/10 rats in 0, 60, 240, and 600 mg/kg groups, respectively. After 30-d convalescence, only one rat in 600 mg/kg group got the incidence of gynecomastia. Serum prolactin concentration had a trend to decrease with increasing dose and prolactin receptors in mammary gland were up-regulated. CONCLUSION: Long-term treatment with moclobemide causes gynecomastia in rats, which is reversible. The mechanism of moclobemide-induced gynecomastia may be related to the increase in prolactin receptors in mammary glands.

Animals↗

PubMed2000

[Production of intergeneric somatic hybrid plants via protoplast electrofusion in citrus].

Leaf derived protoplasts of Sour orange (Citrus aurantium L.) were fused electrically with embryogenic protoplasts of Microcitrus papuana Swingle. Plants were regenerated from the fusion products, which were characteristic with three types of leaf morphology. Most of the plants were identical to Sour orange (namely, Leaf-parent-type plant) and two plants had large and thick leaves whereas one plant had bifoliate and trifoliate leaves. Chromosome examination showed that these plants were diploid with 18 chromosomes (2n = 2x = 18). RAPD analysis was employed to verify the hybrid characteristics of the plants in the first two types. Four 10-mer arbitrary primers with polymorphism were chosen. Band pattern of the plants was similar with the leaf parent (Sour orange) for the primer OPAA-17. Band pattern of the plants was similar with either Sour orange or M. papuana for OPA-08. As for OPA-07 and OPA-04 three kinds of band profiles were detected. Results of RAPD marker, together with chromosome determination, indicated that all of the analyzed plants were intergeneric diploid somatic hybrids between Sour orange and M. papuana.

Cell Fusion↗

PubMed1999

Fulminant hepatitis is significantly increased in hepatitis B carriers after allogeneic bone marrow transplantation.

BACKGROUND: Bone marrow transplantation (BMT) is effective treatment for many hematologic disease, but performed in a population with a high endemic hepatitis B virus carrier rate, the incidence of liver function impairment and fulminant hepatitis (FH) is expected to be raised. METHODS: Forty-three hepatitis B virus carriers received high-dose chemotherapy and BMT, 32 patients received an allogeneic graft, and 11 patients autologous marrow. Acute graft-versus-host disease prophylaxis consisted of methotrexate on day 1, 3, 6, and 11 and cyclosporine for 6 months. RESULTS: After a median follow-up period of 68 months (range: 1-11.5 years), 26 (81.3%) allogeneic BMT patients developed impaired liver function (LF), 5 progressed to FH on day 93, 169, 170, 180, and 468, respectively, and died after an average of 13.8 days (range: 1-45 days). Whereas only 4 (36.4%) autologous BMT patients developed impaired LF, and none FH. Impaired LF (P=0.026, chi-square), and FH (odds ratio=12.86, P=0.009 for coefficient) were significantly related to an allogeneic marrow graft, and the timing of liver function impairment coincided with cyclosporine withdrawal. Hepatitis B surface antigen (HbsAg) disappeared from the serum in 4/14 (28.6%) patients receiving a marrow graft from an HbsAg+ donor. HbsAg was not detected in the serum after BMT in 2/11 (18.2%) autologous BMT patients. CONCLUSIONS: Hepatitis B virus carriers receiving a marrow graft from an HbsAg+ donor have a significantly increased risk of FH.

Adolescent↗

PubMed1999

Structure of a heterophilic adhesion complex between the human CD2 and CD58 (LFA-3) counterreceptors.

Interaction between CD2 and its counterreceptor, CD58 (LFA-3), on opposing cells optimizes immune recognition, facilitating contacts between helper T lymphocytes and antigen-presenting cells as well as between cytolytic effectors and target cells. Here, we report the crystal structure of the heterophilic adhesion complex between the amino-terminal domains of human CD2 and CD58. A strikingly asymmetric, orthogonal, face-to-face interaction involving the major beta sheets of the respective immunoglobulin-like domains with poor shape complementarity is revealed. In the virtual absence of hydrophobic forces, interdigitating charged amino acid side chains form hydrogen bonds and salt links at the interface (approximately 1200 A2), imparting a high degree of specificity albeit with low affinity (K(D) of approximately microM). These features explain CD2-CD58 dynamic binding, offering insights into interactions of related immunoglobulin superfamily receptors.

Amino Acid Sequence↗

PubMed1999

p53 gene mutations and rearrangements in non-Hodgkin's lymphoma.

BACKGROUND: Alterations of the p53 gene have been associated with the progression of certain human malignancies. To establish further the correlation between p53 gene alterations and progression of non-Hodgkin's lymphomas (NHLs), the authors analyzed both mutations and rearrangements of the p53 gene in a cohort of 84 NHLs. METHODS: Eighty-four NHLs were analyzed for p53 gene alterations. Point mutations of exons 5-9 were studied by polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP), and DNA rearrangements were studied by Southern blot analysis. RESULTS. Point mutations and DNA rearrangements of the p53 gene were detected in 6 (7.2%) and 3 (3.6%) patients, respectively. All p53 gene abnormalities were found exclusively in B-cell NHLs. Taken together, patients with p53 gene alterations had poorer survival than other patients (P = 0.024). However, of the three patients with p53 gene rearrangements, the two who appeared to have one normal allele showed a relatively better response to chemotherapy and had longer survival (27 and 47 months). In contrast, the remaining patient who had rearranged bands much stronger than the germline, and thus appeared to have both alleles rearranged, was refractory to chemotherapy and had poorer survival (6 months). CONCLUSIONS: Patients with NHLs of intermediate and high grades who carried point mutations or rearrangements of p53 genes had worse outcomes than other patients. Patients with one abnormal p53 allele and one residual normal allele had a more favorable prognosis than those with two abnormal alleles.

Adolescent↗

PubMed1999

Functional association of TGF-beta receptor II with cyclin B.

Utilizing the cytoplasmic tail of Transforming Growth Factor Receptor Type II (TGFbeta RII) as bait in a yeast two hybrid system, we have identified human cyclin B2 as a direct physical partner of TGFbeta RII. Analysis of deletion mutants of glutathione-S-transferase (GST)-cyclin B2 mapped its binding domain for TGFbeta RII to the C-terminal and revealed a negative regulatory region immediately upstream of the cyclin box. Using recombinant proteins, Cdc2 was demonstrated to indirectly interact with TGFbeta RII via cyclin B2. This interaction was reproduced in THP-1 monocytic cells, where TGFbeta treatment markedly enhanced the ability of cyclin B2 and, correspondingly, Cdc2 from TGFbeta-treated THP-1 cells, to bind the GST-TGFbeta RII fusion protein. More importantly, TGFbeta RII co-precipitated with cyclin B2 in TGFbeta-treated THP-1 cells. TGFbeta treatment also caused threonine phosphorylation of Cdc2 in the TGFbeta RII-cyclin B2-Cdc2 complex in THP1 cells, in parallel with down regulation of Cdc2 function as measured by histone H1 kinase activity. Cyclin B1 had the same capacity to bind TGFbeta RII and mediate indirect Cdc2 binding. These results suggest an alternative mechanism that cell cycle arrest in the G1/S phase caused by TGFbeta may, in part, be due to inactivation of cyclin B/Cdc2 kinase, which is needed for entry into the G2/M phase.

Amino Acid Sequence↗

PubMed1999

Positron emission tomography scan in cortical visual loss in patients with organophosphate intoxication.

OBJECTIVE: To determine the cerebral metabolism of patients with cortical visual loss. DESIGN: Two observational case studies. TESTING: Two patients who survived acute organophosphate poisoning with respiratory failure experienced severe visual loss despite relatively normal ophthalmic examination results. Magnetic resonance imaging of the brain revealed no abnormality of the visual system in either patient. Positron emission tomography (PET) was performed in these 2 patients and in 12 normal subjects with fluorine-18 fluorodeoxyglucose (FDG) as a tracer to measure cerebral glucose metabolism for the estimation of neurologic deficit in the visual cortex. MAIN OUTCOME MEASURES: The FDG uptake values were measured as nanoCurie per cubic centimeters of tissue (nCi/cc). The relative uptake index in visual cortex was computed as the ratio of uptake of FDG in each region of visual cortex to that of cerebellum (regional visual cortex/cerebellum). RESULTS: Hypometabolism was observed in the visual cortex of both patients. The relative uptake index of FDG in visual cortex (visual cortex/cerebellum) was significantly decreased in those patients compared with normal subjects. CONCLUSIONS: In patients with cortical visual loss, conventional neuroimaging techniques can fail to visualize damage that can be detected by PET scanning, and PET analysis may be helpful in estimating the metabolic deficit of visual cortex and in establishing the organic nature of cortical visual loss in these patients.

Adult↗

PubMed1999

Influences of age and gender on dose response and time course of effect of atracurium in anesthetized adult patients.

STUDY OBJECTIVE: To determine the influences of age and gender on the dose response and the time course of effect of atracurium. DESIGN: Prospective, nonrandomized, clinical comparison. SETTING: Operating room, Plastic Surgery Hospital of the Chinese Academy of Medical Sciences and Peking Union Medical College. PATIENTS: 72 adult ASA physical status I patients (38 male and 34 female), aged 15 to 59 years, scheduled for elective plastic surgery. INTERVENTIONS: Patients were divided into the three groups on the basis of age: Group 1, patients aged 15-29 years (n = 32); Group 2, patients aged 30-40 years (n = 21); and Group 3, patients aged 41-59 years (n = 19). Anesthesia was maintained with 60% nitrous oxide in oxygen, thiopental, and incremental doses of fentanyl as required. The dose-response relationship of atracurium was determined by a cumulative dose-response technique. MEASUREMENTS AND MAIN RESULTS: Neuromuscular function was assessed mechanomyographically with train-of-four stimulation at the wrist every 12 seconds and the percentage depression of first twitch (T1) response was used as the study variable. Age and gender significantly affected the dose-response relationship and time course of recovery of atracurium. Advancing age was associated with a reduced effective doses (ED50, ED90, and ED95) of atracurium and a longer duration of action. The effective doses of atracurium were greater, and its duration of action was shorter in men than in women. There were significant differences in the 50%, 90%, and 95% effective dose (ED50, ED90, and ED95) of atracurium, and clinical duration and total duration following administration of atracurium 400 micrograms/kg among the three age groups, and between men and women. CONCLUSIONS: Age and gender have significant effects on the dose response and time course of effect of atracurium. Older patients and women are more sensitive to atracurium-induced neuromuscular block than are young patients and men.

Adolescent↗

PubMed1999

Interim results of the American Vesta trial of endometrial ablation.

STUDY OBJECTIVE: To compare results of endometrial ablation using the Vesta system compared with resection and rollerball. DESIGN: Multicenter, prospective, randomized, controlled study (Canadian Task Force classification I). SETTING: Private practice and academic center. PATIENTS: Women with menorrhagia documented by menstrual diaries who failed or refused hormonal therapy and who had no major uterine organic lesions. INTERVENTIONS: Vesta endometrial ablation or traditional endometrial resection and rollerball ablation. MEASUREMENTS AND MAIN RESULTS: Both groups achieved excellent control of menorrhagia. CONCLUSION: Vesta is an attractive alternative to traditional methods of endometrial ablation. (J Am Assoc Gynecol Laparosc 6(1):45-49, 1999)

Adult↗

PubMed1999

Variations in ocular hemodynamics in patients with early and late glaucoma.

PURPOSE: To determine the retrobulbar hemodynamics in glaucoma patients with different degrees of optic nerve damage. METHODS: Color Doppler imaging was performed in 52 patients with controlled primary open angle glaucoma (POAG) and in 25 control subjects. Glaucomatous eyes were divided into early and late groups based on the perimetry findings. Peak systolic velocity (PSV), end diastolic velocity (EDV), and resistive index of the central retinal artery (CRA) and posterior ciliary arteries (PCA) were evaluated. RESULTS: Early glaucoma showed significantly decreased PSV in nasal PCA when compared with the normal. Late glaucoma showed significantly decreased PSV and EDV in the CRA and nasal PCA, and significantly decreased PSV in temporal PCA as compared with the control and early glaucoma. The resistive index of the CRA also increased significantly in late glaucoma. CONCLUSION: Eyes with advanced glaucomatous optic neuropathy were associated with more marked alterations in retrobulbar circulation than eyes with less nerve damage.

Aged↗