Biomedical subjects
Publications and source records attributed to S Chan.
This study shows that a set time after cuff deflation or after nitroglycerin administration may not be suitable to capture peak, brachial artery dilatory responses in assessing endothelial dysfunction. Automated, continuous monitoring methods are required to simplify identification of peak responses and to standardize reporting.
Using 4.68 fb(-1) of e(+)e(-) annihilation data collected with the CLEO II detector at the Cornell Electron Storage Ring, we have studied tau radiative decays tau(-)-->nu(tau)&mgr;(-)nu;(&mgr;)gamma and tau(-)-->nu(tau)e(-)nu;(e)gamma. For a 10 MeV minimum photon energy in the tau rest frame, the branching fraction for radiative tau decay to a muon or electron is measured to be (3.61+/-0.16+/-0. 35)x10(-3) or (1.75+/-0.06+/-0.17)x10(-2), respectively. The branching fractions are in agreement with standard model theoretical predictions.
The biomechanical properties of plantar tissues were investigated for four older neuropathic diabetic patients and four healthy younger subjects. Indentation tests were performed at four high-pressure areas with three postures in each subject. The tissue thickness and effective Young's modulus were measured by an ultrasound (US) indentation system. The system comprised a pen-size probe having a US transducer at the tip and a load cell connected in series with it. Results showed that the plantar soft tissues of the elderly diabetic patients were significantly stiffer and thinner when compared with the healthy young subjects. For the diabetic subjects tested, the Young's modulus at the 1st metatarsal head was significantly larger than those at the other three sites. This site-dependence was not observed in the healthy young subjects. The plantar tissue became significantly stiffer in the healthy young subjects as a result of posture changes. This posture-dependence of the Young's modulus was not established for the elderly diabetic group.
This article reports the results of a study on the evaluation of the effectiveness of muscle relaxation training in reducing aggressive behavior in mentally handicapped patients (MHPs). A pretest and posttest study design was used. Findings showed that there was a reduction of 14.7% of aggressive behavior in the subjects after the muscle relaxation training. Muscle relaxation training appeared to be effective in reducing the frequency of some aggressive behaviors. The strengths and limitations of using muscle relaxation training in reducing aggressive behaviors are discussed.
This article reports the economic analysis of a study on the implementation of case management in the Community Psychiatric Nursing Service (CPNS) caring for chronic schizophrenic clients in Hong Kong. The purpose of the study was to compare the outcome of case management service with the conventional practice CPNS. Sixty-two subjects participated in the analysis. Cost-effectiveness analysis showed that case management costs more in Hong Kong $3,600 (US$450) per person and that over a 5-month period, case management was associated with improvements in psychological and functional outcomes and patient satisfaction. The results of this study will inform policy makers about resource allocation and policy development in the implementation of case management for the care of mentally ill clients.
This paper reports the preliminary results of a study on the implementation of case management in the community psychiatric nursing service (CPNS). The purpose of the study is to compare the outcome of case management service with the conventional practice of CPNS in the care of chronic schizophrenic clients. The impact of case management service on clients' clinical status, functional level and satisfaction was measured. A matched, pre-post, case-control group design was used to compare case management and conventional care groups. A specific case management model based on the practice at Carondelet Saint Mary's Hospital and Health Centre in Tucson has been developed to care for the schizophrenic clients in the community. Subjects in the experimental group were cared for by CPNs using this case management model. Subjects in the control group were cared for by CPNs based on current practices in the CPNS. Pre- and post-measures were taken upon recruitment and at 5 months later. Findings showed that the experimental group had better outcome in terms of their mental status and functional level when compared with the control group. They were generally more satisfied with the service. When comparing case managers' role with that of conventional CPNs, case managers performed more in areas such as assessment, liaison, case discussion and life skills training. This study demonstrates that this particular model of case management can be effective in caring for clients with long-term mental health problems in Hong Kong.
An urban, public sector Area Mental Health Program reviewed its own bilingual counsellor program as part of an Area-wide quality improvement project, and found that the counsellors' roles needed to be better defined; that mainstream staff needed to have more access to their expertise as cultural consultants; and that their function as an Area team, rather than as service based staff, needed to be encouraged. The bilingual counsellors decided to take up this challenge, and with the support of the Area Director of Mental Health, worked together to redefine their roles.
OBJECTIVE: To determine whether the frequency rate of hyperglycemia and infectious complications can be reduced by an underfeeding strategy in patients requiring total parenteral nutrition (TPN), without deleterious effects on nitrogen balance. DESIGN: Prospective, randomized, controlled nonblinded trial. SETTING: A university-affiliated teaching hospital with a dedicated TPN service. PATIENTS: TPN was initiated in 40 adult patients and continued for > or =5 days. INTERVENTION: Two different TPN feeding strategies were compared: hypocaloric feeding (1 L containing 70 g protein and 1000 kcal) and standard weight-based regimen, begun in similar amounts initially, but advanced in increments toward 25 kcal and 1.5 g protein/kg dry (or adjusted ideal) weight. MEASUREMENTS AND MAIN RESULTS: We evaluated the frequency rate of hyperglycemia, average blood glucose, numbers and types of infections while receiving nutritional support and nitrogen balance after 5 days of TPN. There were significant differences between the quantities of calories, dextrose, fat, and protein provided to the two groups. However, average blood glucose, frequency rate of hyperglycemia, and infection rates (from intravenous catheter, pneumonia, and wound/abdominal collection) were similar in each group. The control group showed a trend toward a higher insulin requirement. Nitrogen balance, only available as a subset, was significantly more negative in the hypocaloric group. CONCLUSIONS: Provision of TPN to a goal of 25 kcal/kg was not associated with more hyperglycemia or infections than a deliberate underfeeding strategy. A regimen of 1.5 g/kg protein in conjunction with 25 kcal/kg did, however, provide significant nutritional benefit in terms of nitrogen balance in comparison with hypocaloric TPN.
An urban mental health service undertook a quality improvement programme to involve staff in the identification and resolution of cross-cultural issues. The programme involved clinical file audits, staff survey and workshops, and a focus group for consumers and their carers. It was found that non-English speaking patients received a different spectrum of services from English speaking patients. Non-English speaking patients were found to receive more pharmacological treatments and less cognitive behavioural therapy. In seeking to address these issues and improve their service delivery to all patients, the mental health service is now in the process of developing cross-cultural training; revising policies and procedures; and engaging bilingual mental health counsellors in a revision of their roles, particularly to increase their availability to staff as cultural consultants.
PURPOSE: To explore the current trends and development of nursing education in China. Nursing education in China has developed rapidly in alignment with economic growth of this vast country. DESIGN: Descriptive, using 345 manuscript abstracts from various regions of China, submitted for the 1996 Sino-Hong Kong Educational Conference. METHODS: Content analysis of manuscript abstracts was done to describe the trends. Codes were determined after several rounds of independent analysis. FINDINGS: Development of nursing education in China appears in line with global trends. The preparation of a pragmatic nurse was emphasized by nurse educators who also advocate total patient care and the integration of traditional Chinese medicine in nursing education. Areas seldom mentioned, however, were student-centered approaches to learning, advanced practice, and the evaluation of educational processes and outcomes. CONCLUSIONS: Nurse educators in mainland China appear aware of the dynamics and challenges in health care, and the need for preparing a new generation of nurses to face these challenges. Educators in China need to adopt new approaches in teaching and learning to prepare nurses to function in a wide range of health care settings, and to monitor and evaluate educational outcomes.
Man-made chemicals that have been shown to modulate endocrine function in animal models, so-called "endocrine disrupters", are suspected to play a role in the development of male reproductive tract abnormalities and neurobehaviroal deficits in children. However in utero exposure to environmental contaminants has not been documented previously. The present study was performed to test our hypothesis that man-made chemicals can be quantified in human amniotic fluid during the second trimester. Gas chromatographic/mass spectrometric (GC/MS) analysis was performed on amniotic fluid samples (n=53) from women (n=51) undergoing routine amniocentesis with a mean (+/- SEM) age of 36.5 +/- 0.5 years and between 15 and 23 weeks of gestation. Analytes included common PCB congeners, the DDT metabolites p,p'-DDE, and o,p'-DDE as well as the pesticides: hexachlorobenzene (HCB); and the three isomers of hexachlorocyclohexane (alpha,beta and gamma-HCH). The limit of quantitation (LOQ) for PCBs was 0.01 ng/ml and for the other organochlorines contaminants is was 0.1 ng/ml. The contaminants alpha-HCH with a mean (+/- SD) concentration of 0.15 +/- 0.06 (ng/ml) and p,p'-DDE with a mean (+/- SD) concentration of 0.21 +/- 0.18 ng/ml were detected in the amniotic fluid. PCB specific congeners were detected with a much lower frequency and levels were in the range of the LOQ. Overall one in three amniotic fluid samples tested positive for at least one environmental contaminant. Therefore, we conclude that approximately one in three fetuses in the Los Angeles area are exposed to endocrine modulatory environmental contaminants in utero the consequences of which remain unknown at this time.
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Ribosomal protein L7a (rp L7a) was identified in a subtractive hybridization screen as a gene up-regulated in human colorectal cancer. Expression of rp L7a was greater than 2-fold higher in tumors compared to adjacent normal mucosa in 72% of the patients studied (n=36). rp L7a was also up-regulated in concomitant polyps. The number of patients with rp L7a T/N ratio of >2 was significantly higher in the female (16/18) than in the male (10/18). rp L7a expression was also significantly higher in females with lymph node involvement compared to males. These results indicate that rp L7a expression is related to tumor growth in colorectal cancer especially in females, where it may also be related to tumor spread. There was no correlation of rp L7a expression with tumor cell differentiation. We also show that rp L7a does not exist as a fusion oncogene (trk-2h) in colorectal cancer.
Coronary embolism is an infrequent phenomenon. A 56-year-old man with hypertrophic obstructive cardiomyopathy and severe mitral regurgitation who underwent left ventricular septal myectomy and mitral valve annular repair is presented. The patient had a cardiac arrest 36 h after surgery. Cardiac standstill, tamponade and a left ventricular rupture were noted when the chest was opened during attempted resuscitation. Autopsy revealed an occlusive embolus of myocardium in the proximal left anterior descending coronary artery. It showed pathological features of hypertrophic cardiomyopathy. There was an extensive acute transmural anteroseptal left ventricular myocardial infarction with rupture of the anterior free wall. Embolism of myocardium - to the coronary arteries, the systemic circulation or the pulmonary circulation - is a rare event, with only nine other cases reported in the literature in the past 30 years. This is the first reported case of myocardial embolus to a coronary artery in a patient with hypertrophic obstructive cardiomyopathy following septal myectomy.
Time-motion (TM) studies are often considered the gold-standard for measurements of the impact of computer systems on task flow and duration. However, in many clinical environments tasks occur too rapidly and have too short of a duration to be captured with conventional paper-based TM methods. Observers may also with to categorize caregiver activities along multiple axes simultaneously. This multi-axial characteristic of clinical activity has been modeled as multiple, parallel finite-state sets and implemented in three computerized data collection tools. Radiology reporting is a domain in which tasks can be characterized by multiple attributes. A radiologist may also switch among multiple tasks in a single minute. The use of these tools to measure the impact of an Automated Speech Recognition (ASR) system on Radiology reporting is presented.
CD5 deficiency results in a hyper-responsive phenotype to Ag receptor stimulation. Here we show that the development and responses of CD4 lineage T cells are regulated by the function of CD5. Thymocytes expressing the I-Ad-restricted DO11.10 TCR undergo abnormal selection without CD5. In H-2d mice, the absence of CD5 causes deletion of double-positive thymocytes, but allows for efficient selection of cells expressing high levels of the DO11.10 clonotype. By contrast, there is enhanced negative selection against the DO11.10 clonotype in the presence of I-Ab. T cell hybridomas and DO11.10 T cells are more responsive to TCR stimulation in the absence of CD5. Such hypersensitivity can be eliminated by expression of wild-type CD5, but not by a form of CD5 that lacks the cytoplasmic tail. Finally, CD5 deficiency partially suppresses the block of CD4 lineage development in CD4-deficient mice. Taken together, the data support a general role for CD5 as a negative regulator of Ag receptor signaling in the development and immune responses of CD4 lineage T cells.
Apolipoprotein E (apoE)-related synthetic peptides, the 22 kDa N-terminal thrombin-cleavage fragment of apoE (truncated apoE), and full-length apoE have all been shown to exhibit neurotoxic activity under certain culture conditions. In the present study, protease inhibitors reduced the neurotoxicity and proteolysis of full-length apoE but did not block the toxicity of truncated apoE or a synthetic apoE peptide, suggesting that fragments of apoE may account for its toxicity. Additional experiments demonstrated that both truncated apoE and the apoE peptide elicit an increase in intracellular calcium levels and subsequent death of embryonic rat hippocampal neurons in culture. Similar effects on calcium were found when the apoE peptide was applied to chick sympathetic neurons. The rise in intracellular calcium and the hippocampal cell death caused by the apoE peptide were significantly reduced by receptor-associated protein, removal of extracellular calcium, or administration of the specific NMDA glutamate receptor antagonist MK-801. These results suggest that apoE may be a source of both neurotoxicity and calcium influx that involves cell surface receptors. Such findings strengthen the hypothesis that apoE plays a direct role in the pathology of Alzheimer's disease.
We applied a subtractive hybridization strategy to obtain genes that are differentially expressed in colorectal carcinoma. Heparin/heparan sulfate interacting protein (HIP) was shown to be up-regulated in colorectal carcinoma. A study of 53 patients with documented colorectal carcinoma showed that 70% of the tumors had HIP tumor-to-normal ratios (expression in tumor tissue compared to expression in normal mucosa) of >2. In six patients with concomitant polyps, HIP expression in the polyps was similar to the carcinoma, showing that up-regulation of HIP may be an early event in tumorigenesis. A significant inverse correlation between HIP levels and the presence of distant metastasis (Duke's stage D) was noted. Similarly, HIP expression was also related to differentiation status in human colorectal carcinoma cell lines. HIP expression was lower in the poorly differentiated COLO 205 cell line compared to the well-differentiated HT-29 cell line. The correlation was further strengthened by studies in COLO 205 cells that were induced to differentiate with herbimycin A treatment. HIP expression was significantly higher when the cells were induced to differentiate. Withdrawal of herbimycin A resulted in a reversal of morphological changes associated with differentiation and an associated decrease in HIP expression. These studies indicate that HIP is an important molecule for cell-cell and cell-extracellular matrix adhesion. The up-regulation of HIP may be an early event in tumorigenesis, and its increased expression may facilitate growth and local invasion. A lower expression of HIP in tumors results in decreased cell adhesion, favoring metastasis. HIP is a candidate marker of abnormal cell growth in the colon and a prognostic marker for colorectal carcinoma.