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Biomedical subjects

S Lee

Publications and source records attributed to S Lee.

At least 649 records · Page 36Linked to original sources
PubMed1998

Assessment of chemosensitivity in patients with osteogenic sarcoma using the doxorubicin binding assay.

BACKGROUND AND OBJECTIVES: Assessment of chemosensitivity in patients with osteosarcoma may help identify those with resistance to chemotherapy. In this study, we investigated the clinical value of the doxorubicin binding assay in its ability to identify patients with drug resistance. METHODS: We tested tumor tissue samples obtained at biopsy of 24 patients with high-grade osteosarcoma aged 9-61 years (mean 19.2) for sensitivity to doxorubicin, using the doxorubicin binding assay. Tumor excision was performed in these patients after neoadjuvant chemotherapy. Chemotherapy response was judged on the basis of tumor necrosis achieved and was compared with doxorubicin sensitivity in each of these patients. RESULTS: Doxorubicin sensitivity was good in 15 and poor in 9 of 24 patients studied. In patients with good sensitivity (n = 15), 9 (60%) exhibited a good response to chemotherapy while response was poor in 6. In patients with poor sensitivity (n = 9), response to chemotherapy was poor in all 9 (100%) patients and 7 (77.8%) of these patients developed metastatic disease within a mean period of 5.2 months, resulting in two deaths. The results were statistically significant at P = 0.0193. CONCLUSIONS: Doxorubicin binding assay may be useful in identifying patients with inherent resistance to chemotherapy. As the outcome of patients showing resistance to doxorubicin is poor, innovative strategies may need to be developed for this group of patients.

Adolescent↗
PubMed1998

Cross-cultural validity of the Eating Disorder Inventory: a study of Chinese patients with eating disorders in Hong Kong.

OBJECTIVE: To evaluate the cross-cultural validity of the Chinese version of the Eating Disorder Inventory (EDI) in a clinical sample of patients with eating disorders in Hong Kong. METHOD: After comprehensive clinical assessment, a consecutive series (1990-1996) of Chinese patients with bulimia nervosa (N = 17) and broadly diagnosed anorexia nervosa (N = 26) completed the Chinese EDI. Results were compared with those of Chinese female undergraduates (N = 606) and Canadian patients with eating disorders. RESULTS: The EDI profiles of bulimic and fat phobic anorectic patients were remarkably and modestly similar to those of their Canadian counterparts. The EDI meaningfully distinguished bulimic patients and fat phobic anorectic patients from local undergraduates, but exhibited deficient criterion-related validity in nonfat phobic anorectic patients. DISCUSSION: The questionable validity of certain EDI subscales in nonfat phobic patients reflects the ethnospecific constructs upon which they are based, and weakens the efficacy of the EDI in screening for anorexia nervosa in Chinese populations. Apart from illustrating some of the conceptual and methodological issues that need to be tackled in the cross-cultural study of the eating disorders, this study furnishes empirical support for the syndromal homogeneity of bulimia nervosa, and the clinical grouping of anorexia nervosa into fat phobic and nonfat phobic subtypes.

Adult↗
PubMed1998

The variable manifestations and contextual meanings of anorexia nervosa: two case illustrations from Hong Kong.

This paper discusses two Chinese anorexic patients with contrasting clinical presentations. Notwithstanding their difference with respect to the presence of the intense fear of becoming fat, their food refusal might arise from a similar sense of powerlessness which exaggerated rigid self-control and hampered self-definition at a critical phase of personal development. In order that early recognition and meaningful treatment may be facilitated, more attention to the variable manifestations and situated meanings of anorexia nervosa in different cultures is emphasized.

Adolescent↗
PubMed1998

Developing musculoskeletal education programs for physicians and the general public: findings from a needs assessment.

OBJECTIVE: To assess the educational needs and learning preferences of primary care physicians and the general public in receiving musculoskeletal health education. METHODS: Prospective surveys were mailed simultaneously to 2,250 primary care physicians and 2,250 members of the general public. The surveys included questions about demographics, motivation for attending programs, and preferred education program formats. RESULTS: The 68 responding physicians attend continuing medical education programs mainly based on topics, speakers, and timing. They prefer lectures and find question and answer sessions least helpful in supporting learning. The 96 responding members of the general public attend programs mainly based on topics, speakers, and fees. The general public stated that question and answer sessions best support learning in programs. A large percentage of responding physicians provide health education to their patients, but a small percentage of the general public respondents stated that they receive health education from physicians. DISCUSSION: Responses from physicians and the general public were generally not surprising but revealed interesting contrasts between learning preferences. While physicians and the general public both value speakers and topics, the physicians want to increase their knowledge about disease, whereas the general public wants practical information. Physicians and the general public also appear to take different approaches to learning. The contrast between availability and provision of health education is also striking. We cannot generalize our results with absolute confidence because the return rates for the surveys were so low. Nonetheless, we support the need to educate physicians and the general public in ways that match their preferred learning methods and educational needs.

Adult↗
PubMed1998

Structure-activity relationship of fluoroquinolone in Escherichia coli.

Structure-activity relationship of 20 fluoroquinolones was studied using the susceptible and 4 resistant Escherichia coli which were developed against 4 fluoroquinolones [ciprofloxacin (1), KR-10755 (6), norfloxacin (2), and ofloxacin (3)] in our laboratory. The C-7 and C-8 substituents of fluoroquinolone were important in various functions such as the inhibitory activity on DNA gyrase, permeability, and efflux. Among 20 fluoroquinolones, compounds with a 3-methyl-3,7-diazabicyclo[3.3.0]octan-1(5)-ene-7-yl substituent at the C-7 position or a chlorine substituent at the C-8 position showed a good inhibitory activity on DNA gyrase (especially a mutated DNA gyrase). Compounds with a 3,7-diazabicyclo [3.3.0]octan-1(5)-ene-7-yl substituent at the C-7 position showed good permeability in the susceptible and resistant strains, while compounds with a fluorine substituent at the C-8 position were less effluxed from cells.

Anti-Infective Agents↗
PubMed1998

Ofloxacin resistance mechanism in PA150 and PA300-clinical isolates of Pseudomonas aeruginosa in Korea.

Five hundred and seventy clinical strains of Pseudomonas aeruginosa were isolated from August 1993 to August 1994 in Korea and screened for their resistance to ciprofloxacin, norfloxacin, and ofloxacin. Among these, two P. aeruginosa strains (PA150 and PA300) were selected based on their strong resistance (MICs > 50 micrograms/ml) to all three quinolones. The susceptible strain as well as two resistant strains had proton gradient-dependent efflux system. Efflux system in PA300 showed different specificities to ofloxacin and ciprofloxacin while PA 150 had less permeability for ofloxacin. Ofloxacin had a less inhibitory action on DNA synthesis in permeabilized cells of PA150 and PA300 than 1771M. When quinolone resistance determining region (QRDR) in gyrA was sequenced, PA300 had one missense mutation, Asn 116Tyr, which was newly reported in this work. The results showed that PA150 became ofloxacin resistant by reduced ofloxacin accumulation due to the existence of efflux system and low permeability, while resistance of PA300 was due to the efflux system and a mutation in QRDR of gyrA-the target site of quinolone.

Base Sequence↗
PubMed1998

A 16.6-kilodalton protein in the Cyanobacterium synechocystis sp. PCC 6803 plays a role in the heat shock response.

The low molecular weight (LMW) heat shock protein (HSP) gene hsp16.6 was identified and cloned from the unicellular cyanobacterium Synechocystis sp. PCC 6803 through comparisons of genomic sequences and conserved gene sequences of the LMW HSPs. Hsp16.6 was isolated using PCR and cloned into the pGEMT plasmid. Hsp16.6 showed a significant increase in transcription after heat shock at 42 degreesC that indicated hsp16.6 was a heat shock gene. To determine the role that hsp16.6 plays in the heat shock response, a mutant Synechocystis cell line was generated. Cell growth and oxygen evolution rates of wild type and mutant cells were compared after heat shock. Results showed significantly decreased cell growth rates and a 40% reduction in oxygen evolution rates in mutants after heat shock treatments. These data indicate a protective role for hsp16.6 in the heat shock response.

Amino Acid Sequence↗
PubMed1998

Intracellular localization of viral RNA in Eimeria necatrix of the domestic fowl.

The intracellular localization of viral RNA in three different stages of Eimeria necatrix, namely, the first- and second-generation meronts and the macrogamonts, were examined at the light microscopy level by in situ hybridization. Digoxigenin-labeled riboprobes generated from partial cDNA clones from 5.6-kb and 4.5-kb dsRNA (pzenv1 and pzenv2) were used in this study. Viral RNA was found to be confined to the cytoplasm of the eimerian host; no viral RNA was detected in chicken tissue. The intense hybridization signal observed in the cytoplasm of the immature meronts with the SP6 riboprobe of pzenv1 or the T7 riboprobe of pzenv2 was probably due to their hybridization to positive strands that had been extruded from the virus during transcription. In mature meronts the intensity of the signal is lower, signifying a decrease in transcription activity. Viral replicase activity may thus be synchronized with the growth phase of the eimerian host.

Animals↗
PubMed1998

Wound tensile strength and contraction rate are not affected by laparotomy or pneumoperitoneum.

BACKGROUND: Many cellular elements responsible for wound healing are affected by laparotomy. The aim of this study was to evaluate the effects of laparotomy and CO2 pneumoperitoneum on wound healing. METHODS: Male Sprague Dawley rats were randomly assigned to one of three experimental groups. Anesthesia control rats underwent no procedure. Pneumoperitoneum group rats were insufflated with CO2 gas. Laparotomy group rats underwent a 7-cm midline laparotomy incision. The interventions were 30 min long. For the incisional study (n = 30), a 4-cm dorsal full-thickness skin incision was made on each rat and then closed with staples. On postoperative days 7 and 14, an equal number of rats were sacrificed from each group, and wound tensile strength measurements were performed. For the excisional study (n = 45), each group of 15 rats underwent a 2-cm diameter circular dorsal full-thickness skin excision. Blinded measurements of wound area were performed every other day until wounds closed. RESULTS: Wound tensile strength values were not significantly different among experimental groups at either time point. The study had a power of 80% to find a 30% difference at POD 7 and a power of 80% to find a 23% difference at POD 14 to a confidence level of p < 0.05. Wound contraction data from the excisional model were analyzed with the Generalized Estimation Equations statistical approach. When we modeled the treatment group as a covariate, no statistical difference was found between groups, demonstrating equal slopes across time. CONCLUSIONS: From the results of these studies, we conclude that wound healing in this model is not significantly diminished following laparotomy or peritoneal insufflation, as compared to anesthesia control.

Animals↗
PubMed1998

Selective attention to food-related stimuli in hunger: are attentional biases specific to emotional and psychopathological states, or are they also found in normal drive states?

Previous work has indicated that anxiety disorders and eating disorders are associated with selective processing of stimuli relevant to patients' concerns (e.g. Mathews and MacLeod, 1994; Annual Review of Psychology, 45, 25-50; Channon et al., 1988; British Journal of Clinical Psychology, 27, 259-260). A dot probe task was used to investigate whether attentional biases are also a feature of a normal drive state. Specifically, we examined whether hunger is associated with biases in selective attention and in pre-attentive processes for food-relevant stimuli. Subjects with high levels of hunger showed a greater attentional bias for food-related words presented in a suprathreshold exposure condition (words shown for 500 msec), in comparison with those with low hunger. There was no evidence in the present study of a hunger-related bias in pre-attentive processes (i.e. when words were shown for 14 msec and masked). Results suggest that a non-emotional motivational state, such as hunger, is associated with a bias in certain aspects of information processing, such as selective attention, for stimuli that are relevant to the motivational state. Findings are discussed in relation to recent research into emotion-related cognitive biases.

Adult↗
PubMed1998

Pilot study on the use of a two-week course of oral misoprostol in patients after termination of pregnancy with mifepristone and misoprostol.

Twenty women who requested early first trimester termination of pregnancy were recruited to study the tolerability of a 2-week course of oral misoprostol after termination of pregnancy by mifepristone and vaginal misoprostol. Ten patients (50%) complained of mild diarrhea during the 2-week course of misoprostol. Otherwise, there were no other significant side effects. The 2-week course of misoprostol was well tolerated by women who underwent early first trimester termination of pregnancy with mifepristone and misoprostol.

Abortifacient Agents, Nonsteroidal↗
PubMed1998

Dysregulation of leptin in response to fasting in insulin-resistant Psammomys obesus (Israeli sand rats).

Leptin is thought to play a significant role in energy balance as an afferent signal to the hypothalamus that reflects body fat content. In addition, leptin may also act as an acute sensor of energy balance independent of body fat mass, since ob gene expression and plasma leptin concentrations are decreased in lean animals and humans in response to short-term caloric deprivation. However, in obese animals and humans, the acute response of leptin to fasting is less clear. We investigated the effects of a 24-hour fast on circulating plasma leptin concentrations in lean and obese Psammomys obesus (Israeli sand rats). In the lean, insulin-sensitive group (n = 25) a 24-hour fast caused a 44% decrease in plasma leptin, whereas in the obese, insulin-resistant group (n = 24) plasma leptin increased by 18% after fasting (P < .003). There was no difference between the two groups regarding the effect of a 24-hour fast on body weight, blood glucose, or plasma insulin. Within the insulin-resistant group, there was no difference in the response of leptin to fasting between hyperglycemic and normoglycemic animals. We conclude that there is a dysregulation of leptin in response to acute caloric deprivation in obese, insulin-resistant but not in lean, insulin-sensitive P obesus.

Animals↗