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Biomedical subjects

Y H Li

Publications and source records attributed to Y H Li.

At least 109 records · Page 6Linked to original sources
PubMed1998

Giant cell tumor of lumbar vertebra. A case report with 13-year followup.

A combined one stage anterior and posterior approach was used to excise a giant cell tumor involving the second lumbar vertebra. The tumor involved the anterior and posterior elements of the vertebra. A wide excision was feasible with immediate stabilization using the Luque instrumentation posteriorly and fibular strut grafts supporting the vertebral bodies anteriorly. The followup period was 13 years. There is no recurrence, and the patient has no symptoms of disease, and the fibular grafts are fully incorporated.

Adult↗
PubMed1998

Successful delayed thrombolytic therapy in a patient with massive pulmonary embolism.

Pulmonary embolism can be a catastrophic event leading to early death or serious hemodynamic instability. Thrombolytic therapy, in addition to heparin therapy, may improve the clinical condition and reduce the chance of recurrent pulmonary embolism in some cases. However, the acceptable "time window" for thrombolytic therapy is not well documented, though it has been used successfully as late as 14 days after pulmonary embolism. Successful delayed thrombolytic therapy beyond this "time window" in patients with massive pulmonary embolism has not been reported. We report a case of massive pulmonary embolism in which thrombolytic therapy was delayed more than 1 month after symptom onset. A 56-year-old woman was taken to National Cheng Kung University Hospital because of an episode of recurrent syncope, followed by progressive shortness of breath of 1 month's duration. Hypoxemia and hemodynamic instability were noted on admission. Echocardiography and a lung perfusion scan provided strong evidence of pulmonary embolism. Subsequent pulmonary angiography confirmed the diagnosis of multiple pulmonary emboli. The patient received a standard dose of intravenous tissue plasminogen activator 7 days after admission because of persistent symptoms and hypoxemia. Her clinical condition dramatically improved after treatment. Follow-up imaging studies showed resolution of the emboli. She was discharged in good condition. This case suggests that delayed thrombolytic therapy in patients with massive pulmonary embolism can still be beneficial in selected cases, even if given more than 2 weeks after symptom onset.

Female↗
PubMed1997

Elevation of soluble adhesion molecules is associated with the severity of myocardial damage in acute myocardial infarction.

In 20 patients with acute myocardial infarction, blood samples were taken to study the serial changes in the soluble intercellular adhesion molecule-1 (ICAM-1), vascular cellular adhesion molecule-1 (VCAM-1) and E-selectin. Results indicated that soluble ICAM-1 increased significantly and persisted throughout the study period; however, soluble E-selectin was significantly elevated only transiently and decreased rapidly thereafter, and the VCAM-1 did not increase during entire study period. There was a significant correlation between the levels of ICAM-1, E-selectin 6 hours after admission, and peak creatine kinase level; the levels of ICAM-1 and E-selectin were also positively correlated with total leukocyte count at admission.

Case-Control Studies↗
PubMed1997

Influence of age on symptoms at presentation in patients with community-acquired pneumonia.

BACKGROUND: Advanced age has become a well-recognized risk factor for death in patients with pneumonia. It may also be associated with reduced symptom reporting, raising the possibility that diagnosis and treatment may be delayed in older patients. OBJECTIVE: To evaluate the association between age and the presenting symptoms in patients with community-acquired pneumonia. METHODS: This study was conducted at inpatient and outpatient facilities at 3 university hospitals, 1 community hospital, and 1 staff-model health maintenance organization. Patients included adults (age > or = 18 years) with clinical and radiographic evidence of pneumonia, who were able to complete a baseline interview. The presence of 5 respiratory symptoms and 13 nonrespiratory symptoms were recorded during a baseline patient interview. A summary symptom score was computed as the total number of symptoms at presentation. RESULTS: The 1812 eligible study patients were categorized into 4 age groups: 18 through 44 years (43%), 45 through 64 years (25%), 65 through 74 years (17%), and 75 years or older (15%). For 17 of the 18 symptoms, there were significant decreases in reported prevalence with increasing age (P < .01). In a linear regression analysis, controlling for patient demographics, comorbidity, and severity of illness at presentation, older age remained associated with lower symptom scores (P < .001). CONCLUSIONS: Respiratory and nonrespiratory symptoms are less commonly reported by older patients with pneumonia, even after controlling for the increased comorbidity and illness severity in these older patients. Recognition of this phenomenon by clinicians and patients is essential given the increased mortality in elderly patients with pneumonia.

Adult↗
PubMed1997

Determination of ticarcillin epimers in plasma and urine with high-performance liquid chromatography.

A high-performance liquid chromatogaphic method was developed for determining the concentrations of ticarcillin (TIPC) epimers in human plasma and urine. Samples were prepared for HPLC analysis with a solid-phase extraction method and the concentrations of TIPC epimers were determined using reversed-phase HPLC. The mobile phase was a mixture of 0.005 M phosphate buffer (pH 7.0) and methanol (12:1, v/v) with a flow-rate of 1.0 ml/min. TIPC epimers were detected at 254 nm. Baseline separation of the two epimers was observed for both plasma and urine samples with a detection limit of ca. 1 microg/ml with a S/N ratio of 3. No peaks interfering with either of the TIPC epimers were observed on the HPLC chromatograms for blank plasma and urine. The recovery was more than 80% for both plasma and urine samples. C.V. values for intra- and inter-day variabilities were 0.9-2.1 and 1.1-6.4%, respectively, at concentrations ranging between 5 and 200 microg/ml. The present method was used to determine the concentrations of TIPC epimers in plasma and urine following intravenous injection of TIPC to a human volunteer. It was found that both epimers were actively secreted into urine and that the secretion of TIPC was not stereoselective. Plasma protein binding was also measured, which revealed stereoselective binding of TIPC in human plasma.

Adult↗
PubMed1997

The hospital admission decision for patients with community-acquired pneumonia. Results from the pneumonia Patient Outcomes Research Team cohort study.

BACKGROUND: The hospital admission decision directly influences the magnitude of resource use in patients with community-acquired pneumonia, yet little information exists on how medical practitioners make this decision. OBJECTIVES: To determine which factors medical practitioners consider in making the hospital admission decision and which health care services they believe would allow ambulatory treatment of low-risk hospitalized patients with community-acquired pneumonia. METHODS: Medical practitioners responsible for the hospital admission decision for low-risk patients with community-acquired pneumonia were asked to describe patient characteristics at initial examination that influenced the hospitalization decision, and to identify the health care services that would have allowed initial outpatient treatment of hospitalized patients. RESULTS: A total of 292 medical practitioners completed questionnaires for 472 (76%) of the 624 low-risk patients eligible for this study. Although all patients had a predicted probability of death of less than 4%, practitioners estimated that 5% of outpatients and 41% of inpatients had an expected 30-day risk of death of more than 5%. Univariate analyses identified 3 practitioner-rated factors that were nearly universally associated with hospitalization: hypoxemia (odds ratio, 173.3; 95% confidence interval, 23.8-1265.0), inability to maintain oral intake (odds ratio, 53.3; 95% confidence interval, 12.8-222.5), and lack of patient home care support (odds ratio, 54.4; 95% confidence interval, 7.3-402.6). In patients without these 3 factors, logistic regression analysis demonstrated that practitioner-estimated risk of death of more than 5% had a strong independent association with hospitalization (odds ratio, 18.4; 95% confidence interval, 6.1-55.7). Practitioners identified home intravenous antibiotic therapy and home nursing observation as services that would have allowed outpatient treatment of more than half (68% and 59%, respectively) of the patients initially hospitalized for treatment. CONCLUSIONS: Practitioners' survey responses suggest that the availability of outpatient intravenous antimicrobial therapy and home nursing care would allow outpatient care for a large proportion of low-risk patients who are hospitalized for community-acquired pneumonia. These data also suggest that methods to improve practitioners' identification of low-risk patients with community-acquired pneumonia could decrease the hospitalization of such patients. Future studies are required to help physicians identify which low-risk patients could safely be treated in the outpatient setting on the basis of clinical information readily available at presentation.

Adult↗
PubMed1997

Fluorescence characterization of type I collagen from normal and silicotic rats and its quenching dynamics induced by hypocrellin B.

In this paper, we studied the quenching mechanism of intrinsic fluorescence of type I collagen by a new type photosensitizer and fluorescence quencher, hypocrellin B (HB). It was indicated that type I collagen can emit Tyr-intrinsic fluorescence with the excitation wavelength of Tyr (lambda(ex) = 269 nm). Its fluorescence decay conform to the triexponential rule of the fluorescence lifetime. The intrinsic fluorescence of type I collagen can be effectively quenched by HB through a process of charge and energy transference, which is involved in the collisional quenching, the dipolar inducement, and the formation of exciplex between HB and excited fluorophores of collagen. The fluorescence quenching would be weakened by higher ionic environments. The fluorescence emission and its quenching rate of abnormal silicotic collagen show falling trends, implying its much weakened potential of charge and energy transference, and its lessen bioelectric activities. In conclusion, the bioelectric properties of collagen depends on the perfect order of its molecular structure and orderly intramolecular and intermolecular interactions, which is important in its performing normal physiological functions. It is also demonstrated that the fluorescence quenching technique, using HB as a quencher, is truly an effectively method for biomolecular studies.

Animals↗
PubMed1997

Catechol O-methyltransferase inhibitor tolcapone has minor influence on performance in experimental memory models in rats.

Two catechol O-methyltransferase inhibitors, peripherally acting entacapone and also centrally acting tolcapone, were tested regarding their capacity to influence learning and memory in adult intact rats. Tolcapone was also studied in rats treated with scopolamine, in adult rats lesioned in the nuclei basalis magnocellularis, and in aged rats. Spatial working memory performance (radial-arm maze) of intact rats was facilitated following pretraining i.p. administration of tolcapone (10 mg/kg). Entacapone was ineffective at doses of 10 and 30 mg/kg. Senescent poor performers improved their accomplishment in the spatial memory task (linear-arm maze) under the influence of tolcapone. Scopolamine (1 mg/kg) impaired working memory performance. Bilateral lesions in the nucleus basalis magnocellularis reduced choline acetyltransferase activity in the frontal cortex by 26% and retarded the learning rate of spatial place task. Tolcapone was not able to counteract the performance deficits in these models. It is concluded that tolcapone can either slightly improve or impair the memory functions depending on task specific elements and performance factors.

Aging↗
PubMed1997

Differential role of glucocorticoids in mediating endotoxin-induced changes in IGF-I and IGFBP-1.

The purpose of the present study was to determine whether endogenous elevations in glucocorticoids mediate the changes in insulin-like growth factor (IGF) 1 and IGF binding protein (IGFBP) 1 levels in plasma and tissues observed after in vivo administration of lipopolysaccharide (LPS). In overnight-fasted male rats LPS injected via the tail vein decreased the IGF-I concentration in plasma, liver, and skeletal muscle (30-45%) and increased IGF-I content in kidney (approximately 3-fold). LPS also decreased IGF-I mRNA abundance in liver and muscle and increased gene expression in kidney. Concomitantly, IGFBP-1 levels in plasma, liver, and muscle were markedly elevated by LPS. All these changes were associated with a greater than fourfold elevation in plasma corticosterone. Pretreatment of rats with the glucocorticoid receptor antagonist RU-486 completely prevented or blunted the LPS-induced changes in IGF-I content in plasma, liver, muscle, and kidney. In liver and muscle RU-486 significantly attenuated the reduction in IGF-I mRNA abundance produced by LPS, but in kidney the LPS-induced increase in IGF-I mRNA was still evident. In contrast, pretreatment with RU-486 did not prevent or attenuate the LPS-induced increase in IGFBP-1 levels in plasma, liver, or muscle. These data suggest that glucocorticoids play a major role in regulating IGF-I mRNA and peptide content in tissues in response to LPS, but the increased IGFBP-1 in blood and tissues induced by LPS appears largely glucocorticoid independent.

Animals↗
PubMed1997

Nutritional influences on biofilm development.

The amounts and types of nutrients in the environment influence the development and final bacterial and chemical composition of biofilms. In oligotrophic environments, organisms respond to nutrient stress by alterations in their cell morphology and cell surfaces, which enhance adherence. Little is known of the responses to stress by bacteria in the animal oral cavity. The environment in the oral cavity is less extreme, and saliva provides a constant source of nutrients. Catabolic cooperation among oral bacteria allow carbon and nitrogen from salivary glycoproteins to be utilized. Modification of growth environments of oral bacteria can influence their cell surfaces and adhesion. Studies in experimental animals have shown that feeding either glucose or sucrose diets or fasting has little effect on the initial stages of development of oral biofilms. However, diet can influence the proportions of different bacterial species later in biofilm development. Studies of competition among populations in communities of oral bacteria in vitro and in vivo have shown the significance of carbon limitation and excess and changes in environmental pH. Relatively few studies have been made of the role of a nitrogen metabolism in bacterial competition in biofilms. In keeping with biofilms in nature, oral biofilms provide a sequestered habitat, where organisms are protected from removal by saliva and where interactions among cells generate a biofilm environment, distinct from that of saliva. Oral biofilms are an essential component in the etiologies of caries and periodontal disease, and understanding the biology of oral biofilms has aided and will continue to aid in the prevention and treatment of these diseases.

Animals↗
PubMed1997

Effect of brucine on mouse nonspecific immune responses.

AIM: To evaluate the effect of brucine (Bru) i.p. at analgesic doses on the nonspecific immune responses in normal and cyclophosphamide (Cyc)-treated mice. METHODS: The clearance of charcoal particles, the immune organ weights, the white blood cell counts in peripheral blood, the phagocytosis to neutral red (NR) of PMO and its IL-1 production in vitro were tested. RESULTS: In normal mice, Bru slightly enhanced the clearance of charcoal particles, the phagocytosis of PMO, IL-1 production, the immune organ weights and the WBC counts (P > 0.05), whereas in Cyc-induced subnormal immunity model mice, Bru greatly enhanced these nonspecific immune responses (P < 0.05 or P < 0.01). The effects of Bru were most marked i.p. at 10 mg.kg-1 in vivo or 0.1-10 mg.L-1 in vitro. CONCLUSION: Bru i.p. at an analgesic dosage has dose- and function-dependent immunoregulatory effects.

Adjuvants, Immunologic↗
PubMed1997

[Analysis of paeonol in Paeonia suffruticosa Andr. and its patent preparations by supercritical fluid extraction and capillary gas chromatography].

A supercritical fluid extraction (SFE) method was developed for the extraction of paeonol in Paeonia suffruticosa Andr. and its patent preparations. A systematic method was used to optimize five variables (temperature, pressure, modifier concentration, static extracting time and CO2 dynamic extracting volume) of SFE. Sample extracts were analyzed by wide-bore capillary gas chromatography (CGC). The method showed good linearity (gamma = 0.9999) in the range of 0.1-1.6 mg.ml-1 of paeonol. The average recovery was 97.8% with RSD = 2.35% (n = 3) for Paeonia suffruticosa andr., 100.3% with RSD = 1.89% (n = 3) for its patent preparations.

Acetophenones↗
PubMed1997

Necrotising fasciitis--an old enemy or a new foe.

Necrotising fasciitis when described by Meleney was caused predominantly by Streptococcus pyogenes. Since then, there were several reports which confirmed streptococcus as the main organism identified in this disease entity. However, recently there were reports of necrotising fasciitis caused by organisms other than Streptococcus. We analysed 19 cases of necrotising fasciitis seen in the Department of Orthopaedic Surgery over a period of 24 months to see if this disease entity has changed significantly. The patients in our series were between the ages of 19 to 85 years with an average age of 57.2 years. Males were more often affected (16 out of 19). The majority of the patients have some form of underlying disease (16 out of 19 cases). There was a trend towards polymicrobial infection and many were resistant to standard antimicrobial therapy. The mortality rate was 21.1%. Our results are comparable to many earlier series.

Adult↗
PubMed1997

[Clinical study on shortening the birth process using psychological suggestion therapy].

To investigate the effect of psychological suggestion therapy on the birth process, a specially designed, prospective study of psychological suggestion ("insubstantial comfort") was undertaken in 120 healthy, full-term primipara with singleton pregnancy and cephalic presentation. All cases were randomly divided into 2 groups, the birth processes and final modes of delivery were analyzed in 60 cases interfered with the psychological suggestion therapy and 60 cases with spontaneous birth processes as control group. The results showed that a significant shorter time of the first and second stages of labor in the study group than that in the control group (P < 0.01). Based on this study, it is suggested that the conversation concerning about the evaluation of individual birth process between the mother-to-be and nurse should be controlled carefully for the purpose of advancing of birth process. The nurse should apply the psychological suggestion therapy during the birth process, specially when answering the question raised by mother-to-be about the quantity of the cervical dilataion. It is also suggested that the purpose of the rectal examination taking during the first stage of labor should be given some kind of meaning of psychotherapy.

Autosuggestion↗
PubMed1996

Isohelicity and phasing in drug--DNA sequence recognition: crystal structure of a tris(benzimidazole)--oligonucleotide complex.

The crystal structure is reported of a tris(benzimidazole) analogue of the minor-groove drug Hoechst 33258 bound to the sequence d(CGCAAATTTGCG)2. The structure has been refined to an R factor of 17.4% at a resolution of 2.2 A. The ligand covers approximately 7 1/2 base pairs, including the 5'-AAATTT central sequence. This has an exceptionally narrow minor-groove width, together with high propeller twists for individual base pairs. The ligand has a highly twisted structure, with an overall twist of 50 degrees between aromatic rings. All three benzimidazole subunits are in register with the DNA, and there is a symmetric group of six hydrogen bonds between ligand and A.T base-pair edges. By contrast, the ligand does not show an optimal isohelical fit to the DNA. The correct phasing of drug and DNA base pairs is ensured by a number of changes to the DNA such that the central 5'-AAATTT region is slightly unwound relative to the structures of other noncovalent minor-groove drug complexes.

Benzimidazoles↗
PubMed1996

Do pulmonary radiographic findings at presentation predict mortality in patients with community-acquired pneumonia?

BACKGROUND: Previous studies have reported conflicting results on whether pulmonary radiographic findings predict mortality for patients with community-acquired pneumonia (CAP). OBJECTIVE: To determine whether pulmonary radiographic findings at presentation are independently associated with 30-day mortality in patients with suspected CAP. METHODS: This study was conducted as part of the Pneumonia Patient Outcomes Research Team multicenter, prospective cohort study of ambulatory and hospitalized patients with clinical and radiographic evidence of CAP. For each patient with CAP, a structured data form was completed by a panel of radiologists to evaluate the radiographic pattern of infiltrate, number of lobes involved, presence of pleural effusion, and 8 other radiographic characteristics. Cox proportional hazards models were used to evaluate the independent association between radiographic findings and 30-day mortality, while controlling for patient demographic, clinical, and laboratory characteristics with a known association with this outcome. RESULTS: Of 2287 patients enrolled in the Pneumonia Patient Outcomes Research Team cohort study, 1906 patients (83.3%) had a pulmonary radiographic infiltrate confirmed by the radiology panel. Overall, 30-day mortality in this cohort was 4.9%. Univariate regression analyses demonstrated the following radiographic characteristics to be significantly associated with 30-day mortality: (1) bilateral pleural effusions (risk ratio [RR], 7.0; 95% confidence interval [CI], 3.9-12.6); (2) a pleural effusion of moderate or greater size (RR, 3.4; 95% CI, 1.4-8.4); (3) 2 or more lobes involved with infiltrate (RR, 2.5; 95% CI, 1.6-3.8); (4) bilateral infiltrate (RR, 2.8; 95% CI, 1.9-4.2); (5) bronchopneumonia (RR, 1.6; 95% CI, 1.0-2.7); and (6) air bronchograms (RR, 0.5; 95% CI, 0.2-0.9). Multivariate analysis of radiographic features and other clinical characteristics showed the presence of bilateral pleural effusions (RR, 2.8; 95% CI, 1.4-5.8) was independently associated with mortality. CONCLUSIONS: In patients with CAP, the presence of bilateral pleural effusions is an independent predictor of short-term mortality. This finding, which is available at presentation, can help guide physicians' assessment of prognosis in CAP.

Adolescent↗
PubMed1996

Importance of left atrial appendage function as a risk factor for systemic thromboembolism in patients with rheumatic mitral valve disease.

One hundred fifty-six patients with rheumatic mitral valve disease were studied with transesophageal echocardiography to assess the influence of left atrial (LA) appendage size and contractile function on the occurrence of systemic embolism. LA appendage function, represented by peak emptying velocity, was found to be a better indicator than LA spontaneous echo contrast as a risk factor for systemic thromboembolism.

Adult↗