Search PubMed⌕ Search

Biomedical subjects

C Y Li

Publications and source records attributed to C Y Li.

At least 127 records · Page 7Linked to original sources
PubMed1999

Bone marrow effects of anagrelide therapy in patients with myelofibrosis with myeloid metaplasia.

In a prospective study investigating the therapeutic role of anagrelide in myelofibrosis with myeloid metaplasia, 20 patients received anagrelide in daily oral doses of 0.5-3 mg. 17 patients were evaluable and received anagrelide for a median of 2 years (range 0.5-4 years). No patient had a clinically appreciable benefit. Bone marrow (BM) examinations at baseline and after 6 and 12 months of treatment were available for 17, 17 and 12 patients, respectively. In all evaluable cases, BM megakaryocyte number increased after 6 months of anagrelide treatment. Also, Ulex europaeus agglutinin-1 staining of megakaryocytes revealed a left-shifted maturation pattern in most patients with a platelet response to anagrelide. However, megakaryocyte staining intensity for transforming (TGF-beta) and platelet-derived (PDGF) growth factors was not affected consistently by treatment. No patient had a >/=2 grade change in either BM fibrosis or osteosclerosis. These in-vivo data support our previous in-vitro observations that anagrelide interferes with megakaryocyte maturation rather than proliferation. Lack of a positive treatment effect is consistent with the finding that anagrelide did not significantly alter megakaryocyte expression of TGF-beta and PDGF.

Aged↗
PubMed1999

Rubella immune status among healthcare workers in the Department of Obstetrics and Gynaecology of a regional hospital in Hong Kong: the need for a vaccination policy.

Rubella infection in early pregnancy is associated with severe consequences in the developing fetus. In Hong Kong, 8-11% of women of child-bearing age are still susceptible to rubella infection. Therefore, rubella immune status of healthcare workers who may have contact with pregnant women is of particular concern. Rubella immunity of healthcare workers in a Department of Obstetrics and Gynaecology was analysed. In the one and a half years of study, 134 healthcare workers voluntarily submitted blood samples for immunity determination and 16.4% of them were susceptible to rubella infection. A substantial proportion of healthcare workers of childbearing age (14%) was negative for rubella antibody. Susceptible healthcare workers have a risk of acquiring and subsequently transmitting the potentially teratogenic rubella infection to their patients. There is a need to review the rubella immunization policy for healthcare workers in Hong Kong.

Adult↗
PubMed1999

A review of the healthy worker effect in occupational epidemiology.

This review article aims to anatomize sources of the healthy worker effect (HWE) and to summarize advantages and limitations of several approaches frequently proposed to eliminate the HWE. Although the HWE is frequently addressed in the context of selection bias, our review suggests that the selection of occupational cohorts with advantageous health status would preferably be addressed as a source of confounding biases. The authors also conclude that the exclusion of unhealthy workers at employment and the study of active workers are the two main sources of HWE, and that the use of the general population as a comparison group in occupational epidemiology should be avoided if possible. The authors encourage investigators to make distinctions between the underlying factors related to the use of the general population as the comparison group in occupational epidemiology.

Bias↗
PubMed1999

A registry-based case-control study of risk factors for the development of multiple non-fatal injuries on the job.

Using compensation records of Taiwan, we conducted a case-control study nested within a cohort of 77,846 active workers who experienced at least one incidence of non-fatal work-related injury between 1994 and 1996 in order to explore factors associated with risk of sustaining multiple non-fatal injuries in the workplace. Cases (n = 2,616) were workers with more than three incidences of non-fatal injury during the study period and controls (n = 3,974) were randomly sampled from workers who experienced only one incidence of non-fatal injury during the same period. Compared with construction workers, workers employed in mining and quarrying (OR = 2.7), manufacturing (OR = 1.2), commerce (OR = 1.6), transport, storage and communication (OR = 1.3) and social, personal and community service (OR = 1.4) were all at significantly elevated risk of multiple non-fatal injuries. Both age and wage showed a significant dose-response effect on the risk of developing multiple non-fatal injuries. The preliminary analysis suggests that workers in certain industries are at significantly elevated risks of multiple work-related non-fatal injuries, in particular those in the mining and quarry industries. Additionally, further preventive measures should be aimed at protecting older workers from such injuries and further studies would help provide more specific interpretations on the positive association between higher wage earning and risk of multiple non-fatal injuries.

Accidents, Occupational↗
PubMed1999

Phase II study of 2-chlorodeoxyadenosine in combination with chlorambucil in previously untreated B-cell chronic lymphocytic leukemia.

The objective was to determine the safety and efficacy of adding a maximally tolerated dose of 2-chlorodeoxyadenosine (2-CdA) to standard chlorambucil (CLB) therapy in previously untreated B-cell chronic lymphocytic leukemia (CLL). Thirty patients with CLL (median age, 64 years) received two courses of 2-CdA given intravenously (2 mg/m2 daily for 7 days) added to biweekly administration of CLB at 30 mg/m2 given orally. The diagnosis of CLL, treatment indications, and response criteria were according to the National Cancer Institute established guidelines. Sixteen patients (53%) had advanced-stage disease, and four (13%) had trisomy 12 abnormality. The overall remission rate was 80%, including 20% complete remission (CR), 30% nodular partial remission (nPR), and 30% partial remission (PR). Minimal residual disease was detected phenotypically in two of five patients with CR and in eight of nine with nPR. Overall, CR, nPR, and PR rates were not influenced significantly by the presence of cytogenetic abnormalities or advanced clinical stage. With a median follow-up of 33 months, 58% of patients who had a response had relapse. Median time to progression in all 30 patients was 30 months, and time to progression and progression-free survival were not significantly different for the different response groups, clinical stages, or cytogenetic groups. Severe neutropenia and thrombocytopenia occurred in 33% and 7% of patients, respectively. Only two patients had documented bacterial infections, and four had herpetic infections. Concurrent combination chemotherapy with abbreviated doses of 2-CdA and standard-dose CLB is feasible and safe in previously untreated CLL. Antitumor activity may be superior to that of CLB alone given in conventional doses. Whether a different schedule of combining these two agents would result in improved outcome is being investigated.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1999

Preincisional dextromethorphan treatment decreases postoperative pain and opioid requirement after laparoscopic cholecystectomy.

UNLABELLED: In the present study, we examined whether preincisional treatment with dextromethorphan (DM) provides preemptive analgesia. Ninety patients scheduled for laparoscopic cholecystectomy were included. Patients receiving chlorpheniramine maleate (CPM) 20 mg via an IM injection 30 min before skin incision were designated as the control group. Patients in Group A received DM 40 mg (containing CPM 20 mg) IM after removal of the gallbladder, whereas in Group B, DM 40 mg (containing CPM 20 mg) was administered IM 30 min before skin incision. Meperidine (1 mg/kg IM) was given for postoperative pain relief as required. Times to first meperidine injection, total meperidine consumption, worst pain score, bed rest time, and side effects were recorded for 48 h after surgery. Times to first meperidine injection were 9.3+/-15.9, 17.4+/-3.4, and 28.6+/-3.9 h for the control group and Groups A and B, respectively. The total meperidine consumption was 90.7+/-11.9, 77.5+/-12.7, and 20.0+/-4.4 mg for the control group and Groups A and B, respectively. The worst visual analog pain scores were 6.0+/-0.2, 6.0+/-0.2, and 4.0+/-0.4 for the control group and Groups A and B, respectively. The bed rest times were 21.0+/-0.5, 20.0+/-0.5, and 19.0+/-0.4 h for the control group and Groups A and B, respectively. The number of patients who required meperidine injection was 26, 22, and 12 for the control group and Groups A and B, respectively. We conclude that DM is more effective in producing postoperative analgesia when it is administered preincision rather than after the gallbladder removal treatment, which suggests a preemptive analgesic effect. IMPLICATIONS: Preincisional dextromethorphan (40 mg IM) treatment offers a preemptive analgesic effect, thus improving the postoperative pain management.

Analgesics, Opioid↗
PubMed1999

Glucose intolerance and other cardiovascular risk factors in chinese women with a history of gestational diabetes mellitus.

Women with a history of gestational diabetes (GDM) are at increased risk of developing diabetes compared with other women. There are few data on associations between GDM and cardiovascular risk factors. Between 1988 and 1995, 801 Chinese women with a history of GDM were recruited for a 75g oral glucose tolerance test (OGTT) and assessment of various cardiovascular risk factors, namely obesity, hypertension and dyslipidaemia, 6 weeks after delivery at the Diabetes Centre of the Prince of Wales Hospital. Another 431 women with no past history of diabetes or GDM recruited in a diabetes prevalence study were used as control subjects. After adjustment for age, body mass index and smoking, the prevalence of glucose intolerance remained higher in women with a history of GDM when compared to normal controls. The relative risks of obesity, hypertension, dyslipidaemia, diabetes and impaired glucose tolerance in women with a history of GDM comparing to normal subjects were, respectively, 2.4, 7.5, 2.4, 8.1 and 5.0. After excluding those with abnormal glucose tolerance, subjects with a history of GDM still had more adverse cardiovascular risk factors, including higher blood pressure, glycaemic and lipid parameters, than control subjects (after adjustment for age, body mass index and smoking). In conclusion, compared with normal subjects, Chinese women with a history of GDM had an 8-fold increased risk of having diabetes based on their OGTTs performed 6 weeks postdelivery. These women also have increased rates of other cardiovascular risk factors including obesity, high blood pressure and dyslipidaemia.

Adolescent↗
PubMed1999

Incidence of and predictors for chronic disability in activities of daily living among older people in Taiwan.

OBJECTIVES: To estimate the incidence of chronic activities of daily living (ADL) disability and to analyze the sociodemographic, health status, adverse lifestyle, and leisure-time physical activity predictors for chronic ADL disability. DESIGN: We recruited a cohort of community-dwelling older people in Taipei, Taiwan, who were not ADL disabled in August 1993, and we followed them until August 1996. SETTINGS AND PARTICIPANTS: The study subjects were 1321 community-dwelling people aged 65 years or older who were ADL intact at the initial interview in August 1993. The study sample was a subset of a probability sample (n = 1583) randomly selected from household registrations in the four districts of the Taipei metropolitan area. MEASUREMENTS: Baseline information regarding various factors potentially associated with the development of chronic ADL disability was assessed and collected at the beginning of the study. Study participants were assessed annually for ADL function by a structured home interview using a six-item scale. Participants who were unable to perform independently at least one of the six items--eating, bathing, dressing, toileting, transfers, and walking inside the house--for more than 3 months were considered chronically ADL disabled. Cox proportional hazard regression models were utilized to examine the independent effect of the potential predictors on risk of chronic ADL disability. RESULTS: During the 3-year study period, 145 (11.0%) participants developed chronic ADL disability, 58 (4.4%) participants were lost to follow-up, and 83 (6.3%) participants died. Multiple hazard regression analysis showed that individuals aged 70 to 79 years or older than age 80 had increased risk of ADL disability (relative risk: 2.05 (95% confidence interval (CI), 1.35-3.11) and 3.89 (95%CI, 2.33-6.50), respectively) compared with those participants younger than age 70. Risk of chronic ADL disability was inversely associated with routine exercise (RR = 0.52; 95% CI, 0.39-0.68). CONCLUSIONS: Age is the most significant predictor of chronic ADL disability. Lack of routine exercise is also a significant predictor of ADL disability in older adults.

Activities of Daily Living↗
PubMed1999

Shape interactions in macaque inferior temporal neurons.

Missal et al. observed that the responses of inferior temporal (IT) neurons to a shape were reduced markedly when this shape partially overlapped a larger second shape, suggesting that shape interactions determine IT responses. In the present study, we compared the responses of IT neurons with combinations of two shapes which did or did not overlap and studied the effect of the relative and absolute positions of the two shapes. In a first test, a preferred shape (figure) was presented at the fixation point while a second, nonpreferred, shape was displayed either in the background of the figure (overlap) or at one of four peripheral positions (nonoverlap). Controls consisted of presentations of either shape in isolation at each of the five positions. The stimuli were presented during a fixation task. The responses to these combinations of two shapes were, on average, reduced compared with those elicited by the preferred shape presented in isolation. This suppression occurred whether or not the two shapes overlapped, but the degree of suppression in the overlap and nonoverlap conditions did not correlate. These interactions were stronger when the interacting stimulus was located in the contralateral compared with the ipsilateral hemifield. The position of the interacting stimulus within a hemifield significantly affected the suppression associated with combined shapes in some neurons. The strength of the interactions of the two nonoverlapping shapes depended on the shape of the interacting stimulus in half of the neurons. In a second test, the preferred shape and interacting stimulus could appear either at the fixation point or at one eccentric position. Here we found that the suppression was, on average, strongest when the interacting stimulus, rather than the preferred shape, was presented at the fixation position. Also, in 40% of the neurons, the response reduction was similar in overlap and nonoverlap conditions if effects of stimulus position were taken into account. In both tests, we also measured the responses to combinations of a nonpreferred shape and the interacting stimulus and showed that the response to a combination of two nonpreferred shapes was, in general, smaller than the response to a combination of the preferred and nonpreferred shape. Overall the results indicate that stimulus interactions in the receptive fields of IT neurons can be position and shape selective; this can contribute to the coding for the relationships between object parts.

Animals↗
PubMed1999

Effects of cognitive impairment and loss of physical capacities on survival of the elderly.

This study investigates the effects of cognitive impairment and loss of physical capacity on the survival rates of the elderly in Taiwan. Data used for this research were obtained from a longitudinal study in northern Taiwan, where 1,434 elderly respondents were randomly selected and were interviewed in 1993 and 1996. Respondents were categorized into four groups: those with physical disability, those with cognitive impairment, those with neither condition and those with both conditions. The survival rates of these four groups were analyzed and compared. The effects of cognitive impairment and physical disability were assessed separately and jointly. Within the study period, we found that elderly persons with both conditions had the lowest survival rate (0.54, 95% confidence interval (CI) 0.35-0. 73), while those with neither condition had the most favorable survival rate (0.92, 95% CI 0.90-0.93). Results from the Cox proportional hazard model showed that physical disability had a significantly adverse effect on the risk of mortality (relative risk 2.5, 95% CI 1.5-4.2), while cognitive impairment did not. Our results are consistent with previous findings which have shown that the decline in physical function affects mortality more than the decline in cognitive function.

Activities of Daily Living↗
PubMed1999

The bakkenolides from the root of Petasites formosanus and their cytotoxicity.

Thirty-two new bakkenolides, bakkenolides-Db (1)--Dh(7), -Fa(8), -Fb(9), -I(10)--M(14), -Na(15), -Nb(16), -O(17)--T(22), -Ua (23), -Ub(24), -V(25)--X(27), -Ya(28), -Yb(29), -Za(30), -Zb(31) and -III(32), from the roots of Petasites formosanus together with thirty known compounds were isolated. The structures were characterized by spectral analysis. The locations, C-1 and/or C-9 of bakkenolide skeleton, of the substituents, such as acetoxy, isobutyroyloxy and isovaleroyloxy groups, can be determined by the chemical shifts of their signals and the H-1 and/H-9 in the 1H-NMR spectra. The cytotoxicity was also discussed.

Animals↗
PubMed1999

An evaluation of radio frequency exposure from therapeutic diathermy equipment.

To assess the physiotherapist's exposure to radio frequency electromagnetic fields (RF) leaking from short wave diathermy equipment, we conducted on-site measurements of stray electric and magnetic fields (27.12 MHz) close to continuous wave (CW) short wave equipment. The results show that the operator's knees may have the highest exposure level for both electric field (E-field) and magnetic field (H-field) in the normal operating position, i.e., behind the device console. The whole-body E-field exposure normally does not exceed the 1992 IEEE recommended limit during a normal treatment session. On the other hand, the operator's whole-body exposure to H-field was barely below the recommended limit. Our data suggest little chance of immediate harmful effects of RF leakage from the diathermy. Nonetheless, physiotherapists should still be advised to remain at a distance of at least 20 cm from the electrodes and cables to avoid possible overexposure.

Allied Health Personnel↗
PubMed1999

Successful pregnancy in a woman with secondary biliary cirrhosis with portal hypertension from recurrent pyogenic cholangitis. A case report.

BACKGROUND: Pregnancy in women with secondary biliary cirrhosis due to recurrent pyogenic cholangitis is extremely rare. Little information is available on the effect of pregnancy on the disease and vice versa. CASE: A patient who had secondary biliary cirrhosis due to recurrent pyogenic cholangitis complicated by splenomegaly and portal hypertension had a successful pregnancy. Although she had a history of esophageal variceal bleeding before this pregnancy, there was no such bleeding during pregnancy. She had an uneventful antenatal course except that her liver enzyme level fluctuated slightly. The serum bilirubin level increased during the third trimester of pregnancy but returned to the prepregnant level after delivery. CONCLUSION: Termination of pregnancy may not be the only option for management. The management protocol for patients with primary biliary cirrhosis complicating pregnancy, which includes regular fetal surveillance and monitoring of maternal liver function, should be considered for pregnant women with secondary biliary cirrhosis.

Adult↗
PubMed1999

Synergistic anticancer effects of tetrandrine combined with doxorubicin or vincristine in vitro.

AIM: To study the interaction between tetrandrine (Tet) and doxorubicin (Dox) or vincristine (Vin) against human breast cancer cell lines MCF-7 and MCF-7/Dox or human nasopharyngeal cancer cell lines KB and KBV200 in vitro. METHODS: Anticancer activities of a drug alone and a drug combination of Tet and Dox or Vin were determined by tetrazolium (MTT) method. The interaction between Tet and Dox or Vin was evaluated by both a value of a sum of fractional inhibitory concentration (SFIC) and an isobologram method. RESULTS: The SFIC values of the three-different-ratio combinations between Tet and Dox ranged from 0.14 to 0.38 for MCF-7, and 0.10 to 0.29 for MCF-7/Dox; those of Tet-Vin combinations ranged from 0.21 to 0.37 for KB, and 0.32 to 0.63 for KBV200. All the SFIC values of the combination between Tet and Dox or Vin were less than 1.0 when the 3 ratios of the 2 drugs in combination were used, and the shapes of isobolic curves obtained from the combination were concave. CONCLUSION: The interaction between Tet and Dox or Vin against the human cancer cells was markedly synergistic.

Alkaloids↗
PubMed1998

Oral contraceptives and breast cancer risk in Taiwan, a country of low incidence of breast cancer and low use of oral contraceptives.

One hundred and seventy four (81% of all) pathologically confirmed new incident cases of female breast cancer identified from a medical center in Taipei from February, 1993 to June, 1994 were selected as the case group. Four hundred and fifty three inpatient controls who were without obstetric-gynecological, breast, or malignant diseases were individually matched for each case by age and date of admission. Information was obtained through direct interview and review of medical records. Conditional logistic regression was used to estimate the effects of each risk factor. After adjusting for education level, body mass index, age at menarche and first full-term pregnancy, parity, menopausal status and age at menopause, lifetime lactation, use of lactation inhibition hormones, and family history of breast cancer, breast cancer risk significantly elevated in use of OC before 25 years old and before 1971. In stratified analysis, significantly higher risk were found in OC use before 25 years old and in duration of use less than one year among post-menopausal subjects. Our results support the notion that OC use in early life for younger women and in early calendar years increase breast cancer risk.

Age Factors↗
PubMed1998

Molecular mimicry in Guillain-Barré syndrome.

Guillain-Barré syndrome (GBS) is the commonest cause of acute flaccid paralysis worldwide. Recent pathological and electrodiagnostic studies indicated that there are different patterns within this syndrome. The demyelinating pattern predominates in North America and Europe, whereas axonal variants of GBS occur more frequently in Northern China. Infection with Campylobacter jejuni is one of the most frequently recognized antecedent events in all variants of GBS. The lipopolysaccharides of these organisms share ganglioside-like epitopes with peripheral nerves, and patients with GBS have antiganglioside antibodies. These observations have given rise to the hypothesis that "molecular mimicry" is the immunopathogenic mechanism of injury to peripheral nerve fibers. With this hypothesis in view, we summarize our experience of GBS as it occurs in Northern China. To explore the role of molecular mimicry in this cohort we sought evidence of preceding Campylobacter infection and correlated this with clinical characteristics and antiganglioside serology. Based on our results we propose a sequence of pathogenic events leading to peripheral nerve injury in GBS.

Adolescent↗
PubMed1998

Source of electrocardiographic ST changes in subendocardial ischemia.

To clarify the source of electrocardiographic ST depression associated with ischemia, a sheep model of subendocardial ischemia was developed in which simultaneous epicardial and endocardial ST potentials were mapped, and a computer model using the bidomain technique was developed to explain the results. To produce ischemia in different territories of the myocardium in the same animal, the left anterior descending coronary artery and left circumflex coronary artery were partially constricted in sequence. Results from 36 sheep and the computer simulation are reported. The distributions of epicardial potentials from either ischemic source were very similar (r=0.77+/-0.14, P<0.0001), with both showing ST depression on the free wall of the left ventricle and no association between the ST depression and the ischemic region. However, endocardial potentials showed that ST elevation was directly associated with the region of reduced blood flow. Insulating the heart from the surrounding tissue with plastic increased the magnitude of epicardial ST potentials, which was consistent with an intramyocardial source. Increasing the percent stenosis of a coronary artery increased epicardial ST depression at the lateral boundary and resulted in ST elevation starting from the ischemic center as ischemia became transmural. Computer simulation using the bidomain model reproduced the epicardial ST patterns and suggested that the ST depression was generated at the lateral boundary between ischemic and normal territories. ST depression on the epicardium reflected the position of this lateral boundary. The boundaries of ischemic territories are shared, and only those appearing on the free wall contribute to external ST potential fields. These effects explain why body surface ST depression does not localize cardiac ischemia in humans.

Animals↗