Biomedical subjects

M Sun

Publications and source records attributed to M Sun.

At least 127 records · Page 7Linked to original sources

PubMed1999

Comparison of air-displacement plethysmography with hydrostatic weighing and bioelectrical impedance analysis for the assessment of body composition in healthy adults.

BACKGROUND: Over the past decade, considerable attention has been paid to accurately measuring body composition in diverse populations. Recently, the use of air-displacement plethysmography (AP) was proposed as an accurate, comfortable, and accessible method of body-composition analysis. OBJECTIVE: The purpose of this study was to compare measurements of percentage body fat (%BF) by AP and 2 other established techniques, hydrostatic weighing (HW) and bioelectrical impedance analysis (BIA), in adults. DESIGN: The sample consisted of healthy men (n = 23) and women (n = 24). %BF was measured by AP, HW, and BIA. RESULTS: In the total group, %BF(AP) (25.0+/-8.9%) was not significantly different from %BF(HW) (25.1+/-7.7%) or %BF(BIA) (23.9+/-7.7%), and %BF(AP) was significantly correlated with %BF(HW) (r = 0.944, P < 0.001) and with %BF(BIA) (r = 0.859, P < 0.01). Compared with HW, AP underestimated %BF in men (by -1.24+/-3.12%) but overestimated %BF in women (by 1.02+/-2.48%), indicating a significant sex effect (P < 0.05). The differences in estimation between AP and BIA and between BIA and HW were not significantly different between the sexes. CONCLUSION: AP is an accurate method for assessing body composition in healthy adults. Future studies should assess further the cause of the individual variations with this new method.

Adipose Tissue↗

PubMed1999

Strategic groups and performance in the nursing home industry: a reexamination.

This study further examines the relationship between strategic group membership and performance in the nursing home industry. The results indicate seven strategic groups in the industry with significant between-group differences in operating margin, average profit per patient day, catheterization rate, health deficiencies, life and safety deficiencies, and efficiency in the provision of services. The authors did not, however, find significant between-group differences in pressure sore rate, the use of restraints, or in the percentage of patients with significant unplanned weight changes. The group with the highest private-pay utilization combined with high Medicare utilization generally performed the best along all indicators. Results also suggest that strategic group membership and rural/urban location have a greater impact on performance than do ownership, chain membership, or possession of a dedicated specialty care unit.

Analysis of Variance↗

PubMed1999

Prognostic significance of extent of disease in bone in patients with androgen-independent prostate cancer.

PURPOSE: To evaluate the prognostic significance of a bone scan index (BSI) based on the weighted proportion of tumor involvement in individual bones, in relation to other factors and to survival in patients with androgen-independent prostate cancer. PATIENTS AND METHODS: Baseline radionuclide bone scans were reviewed in 191 assessable patients with androgen-independent disease who were enrolled onto an open, randomized trial of liarozole versus prednisone. The extent of skeletal involvement was assessed by scoring each scan using the BSI and independently according to the number of metastatic lesions. The relationship of the scored bone involvement to other known prognostic factors was explored in single- and multiple-variable analyses. RESULTS: In single-variable analyses, the pretreatment factors found to be associated with survival were age (P = .0446), performance status (P = .0005), baseline prostate-specific antigen (P = .0001), hemoglobin (P = .0001), alkaline phosphatase (P = .0002), AST (P = .0021), lactate dehydrogenase (P = .0001), and treatment (P = .0098). The extent of osseous disease was significant using both the BSI (P = .0001) and the number of lesions present (P = .0001). In multiple-variable proportional hazards analyses, only BSI, age, hemoglobin, lactate dehydrogenase, and treatment arm were associated with survival. When the patient population was divided into three equal groups, with BSI values of < 1.4%, 1.4% to 5.1%, and > 5.1%, median survivals of 18.3, 15.5, and 8.1 months, respectively, were observed (P = .0079). CONCLUSION: The BSI quantifies the extent of skeletal involvement by tumor. It allows the identification of patients with distinct prognoses for stratification in clinical trials. Further study is needed to assess the utility of serial BSI determinations in monitoring treatment effects. The BSI may be particularly useful in the evaluation of agents for which prostate-specific antigen changes do not reflect clinical outcomes accurately.

Aged↗

PubMed1999

Acute effect of ephedrine on 24-h energy balance.

Ephedrine is used to help achieve weight control. Data on its true efficacy and mechanisms in altering energy balance in human subjects are limited. We aimed to determine the acute effect of ephedrine on 24-h energy expenditure, mechanical work and urinary catecholamines in a double-blind, randomized, placebo-controlled, two-period crossover study. Ten healthy volunteers were given ephedrine (50 mg) or placebo thrice daily during each of two 24-h periods (ephedrine and placebo) in a whole-room indirect calorimeter, which accurately measures minute-by-minute energy expenditure and mechanical work. Measurements were taken of 24-h energy expenditure, mechanical work, urinary catecholamines and binding of (+/-)ephedrine in vitro to human beta1-, beta2- and beta3-adrenoreceptors. Twenty-four-hour energy expenditure was 3.6% greater (8965+/-1301 versus 8648+/-1347 kJ, P<0.05) with ephedrine than with placebo, but mechanical work was not different between the ephedrine and placebo periods. Noradrenaline excretion was lower with ephedrine (0.032+/-0.011 microg/mg creatinine) compared with placebo (0.044+/-0.012 microg/mg creatinine) (P<0.05). (+/-)Ephedrine is a relatively weak partial agonist of human beta1- and beta2-adrenoreceptors, and had no detectable activity at human beta3-adrenoreceptors. Ephedrine (50 mg thrice daily) modestly increases energy expenditure in normal human subjects. A lack of binding of ephedrine to beta3-adrenoreceptors and the observed decrease in urinary noradrenaline during ephedrine treatment suggest that the thermogenic effect of ephedrine results from direct beta1-/beta2-adrenoreceptor agonism. An indirect beta3-adrenergic effect through the release of noradrenaline seems unlikely as urinary noradrenaline decreased significantly with ephedrine.

Adrenergic alpha-Agonists↗

PubMed1999

[The influence of the 20 kDa protein from Bacillus thuringiensis subsp. israelensis on the cytolytic activity of CytA].

In order to understand the influence of the 20 kDa protein on the cytolytic activity of CytA protein, a set of PCR primers were designed to amplify 20 kDa protein and CytA protein genes. The genes were ligated to E. coli expression vector pUHE24 and transformed into E. coli XL1 and DH5 alpha. The clones, LZ20, LZcytA and LZ20A containing 20 kDa protein gene, cytA protein gene and 20 kDa-cytA genes were obtained respectively. The influence of the clones on the growth of E. coli cells was determined under induction of IPTG. The results showed that the growth of LZ20 cells were not affected, LZcytA cells were killed, and the growth of LZ20A cells were not affected. It was suggested that expression product of 20 kDa protein gene protected the host cells from the cytolytic effect of CytA protein. This was supported by using different host strains.

Bacillus thuringiensis↗

PubMed1999

Effects of storage and cooking on the iodine content in iodized salt and study on monitoring iodine content in iodized salt.

In order to ensure that the intake of iodine from iodized salt is adequate, the effects of cooking, storage and iodination on iodine content in iodized salt have been studied. For monitoring the analytical performance, a quality control examination was also undertaken. The loss of iodine was greater when salt was stored in plastic bag than in glass bottle. The loss was greater in fortified salt stored at 37 degrees C and under 76% humidity than in that at 20-25 degrees C and under lower humidity. The retention of iodine varied with the kind of foods and also was influenced by the water content of cooked food. In general, the retention of iodine during cooking varied considerably (from 36.6% to 86.1%). The iodine concentration in salts varied greater from 3.0 to 100.3 mg/kg in salt for markets, and from 0 to 90.0 mg/kg in salts for households. 48.3% of samples from markets were found to be in compliance with national standards (30-50 mg/kg), and 72.0% of samples from households were in compliance with national standard (20-50 mg/kg). Analytical data collected from 8 of the cooperative laboratories for an analytical reference material showed a 95% confidence interval of the population mean for both precision and accuracy, falling within X +/- 2SD and passing quality control examination.

Food Preservation↗

PubMed1999

Reproductive biology and conservation genetics of Goodyera procera (Orchidaceae).

Goodyera procera is an endangered terrestrial orchid in Hong Kong. Information on its reproductive biology and pattern of genetic variation is needed to develop efficient conservation strategies. Pollination experiments showed that the species is self-compatible, but dependent on pollinators for fruit set. Bagged plants produced no fruits. Artificial pollinations resulted in 92% fruit set through selfing, 94% with geitonogamous pollination, and 95% following xenogamous pollination. Fruit set in the open-pollinated control was 75% at the same sites. Allozyme electrophoresis and random amplified polymorphic DNA (RAPD) were used to evaluate genetic variation and structure of 15 populations of Goodyera procera. Despite its outbreeding system, allozyme data revealed low variation both at the population (P = 21.78%, A = 1.22, and H = 0.073) and species (P = 33%, A = 1.33, and H = 0.15) levels, in comparison with other animal-pollinated outbreeding plant species. However, RAPD variation was relatively high (P = 55.13% and H = 0.18 at the population level, and P = 97.03% and H = 0.29 at the species level). G(ST) estimates indicated high levels of genetic differentiation among populations (G(ST) = 0.52 and I = 0.909 ± 0.049 based on allozyme data, and G(ST) = 0.39 and I = 0.859 ± 0.038 based on RAPD data), much above the average for outcrossing species, suggesting that gene flow was limited in this species. Based on these data, suitable strategies were developed for the genetic conservation and management of the species.

Journal Article↗

PubMed1999

[Lactulose mannitol ratio in patients after operation].

OBJECTIVE: To study lactulose (lactulose, L) and mannitol (mannitol, M) ratio in urine following operation and investigate the correlation between severity of stress and L/M ratio. METHODS: 20 patients who had received operation were enrolled and each patient was evaluated by APACH II scores. L/M permeability study was performed before the operation and 5 and 10 days after the operation. The L and M concentration was analyzed by HPLC with pulsed electrochemical detection (HPLC-PED). The correlation between L/M ratio and the severity of surgical stress were related. RESULTS: The L/M ratio before the operation was (0.023 +/- 0.002), increased to (0.042 +/- 0.005) in the 5th post-operative day (P < 0.01), and then returned to (0.024 +/- 0.002) (P > 0.05) compared with pre-operation in the 10th Post-operation. A significant correlation between the severity of stress and the L/M ratio was observed (r = 0.762). CONCLUSIONS: The L/M ratio was increased 5 days after the operation and the L/M ratio was correlated with severity of operative stress.

APACHE↗

PubMed1999

[Effects of methylmercury on embryonic cell behavior and expression of related gene].

OBJECTIVE: To explore the mechanism of embryonic developmental toxicity of methyl mercury at cellular and gene levels. METHODS: Effects of methylmercury on embryonic cell behavior and gene expression in rats were observed with in vitro (0, 0.05, 0.10, 0.20, 0.40, 0.80 and 1.60 mg/L of methylmercury) and in vivo (0, 0.2, 0.4, 0.8, 1.6 and 3.2 mg/L of methylmercury) rat models, in situ hybridization and TdT-induced dUTP nick end labeling techniques. RESULTS: Methylmercury could pass through yolk-sac placenta quickly, and inhibit placenta development and blood vessel differentiation there at higher concentration. There was a dose-response relationship between concentration of methylmercury and its embryonic developmental toxicity. Its developmental toxicity mainly characterized as patent neural tube and anomalous flexion. Methylmercury could induce excessive apoptosis of embryonic cells, inhibit apparently the synthesis of cellular DNA and RNA and damage its cellular ultrastructure. It also could induce significantly the expression of heat shock protein 70 mRNA and inhibit the expression of fibronectin and p16 mRNA. There was relationship between heat shock protein 70 mRNA, Ca(2+), apoptosis and teratogenesis. CONCLUSION: Disturbance of embryonic cell behavior and related gene expression played important roles in developmental toxicity caused by methylmercury.

Animals↗

PubMed1999

[Alteration of blood glucose, insulin and lipid in the offsprings of patients with essential hypertension].

We prospectively investigated the serum insulin, glucose and serum lipoproteins in 40 normotensive offsprings(test group) of parents with essential hypertension compared with 35 normotensive offsprings (control group) of the normotensive families. Compared with control group, the test group was significantly elevated in fasting serum insulin levels(6.82 +/- 2 vs 4.02 +/- 1.7 microU.ml-1) (P < 0.05), fasting serum glucose(4.32 +/- 0.4 vs 3.84 +/- 0.5 mmol.L-1), serum total triglycerides(1.97 +/- 0.8 vs 1.32 +/- 0.5 mmol.L-1), total cholesterol(Tch) (5.13 +/- 1.0 vs 4.24 +/- 0.6 mmol.L-1), low density lipoprotein cholesterol (2.82 +/- 1.0 vs 2.24 +/- 0.7 mmol.L-1), very low density lipoprotein cholesterol (1.02 +/- 0.4 vs 0.66 +/- 0.27 mmol.L-1), high density lipoprotein cholesterol/Tch ratio (0.27 +/- 0.08 vs 0.33 +/- 0.07 mmol.L-1). While post-glucose load the serum insulin and glucose level after glucose load were much higher (P < 0.01) in the test group than that in controls. The findings demonstrated that young normotensive offsprings of parents with hypertension had excellent health, they had an impairment of insulin-mediated glucose disposal, hyperinsulinemia, and dyslipidemia. These findings supported that a common hereditary defect exits in familial trait for essential hypertension and disturbance of carbohydrate and lipoprotein metabolism may be detected before or at least at very early stage of the development of essential hypertension.

Adult↗

PubMed1999

[Investigation of the bone mineral density in hemodialysis patients for different terms].

The investigate the change of bone mineral density(BMD) in hemodialysis patients for different terms of hemodialysis, 50 patients were divided into three groups according to the duration of hemodialysis. Group I was < 5 years. Group II was 5-10 years, and Group III > 10 years. The BMD of the patients were assayed by using dual energy X-ray bone absorptiometer. Serum calcium, phosphorus, aluminium, and intact parathyroid hormone(iPTH) were detected at the same time. The mean BMD and serum iPTH were 0.624 +/- 0.180 g.cm-2 and 9.67 +/- 9.46 ng.cm-1 in Group I, 0.573 +/- 0.160 g.ml-2 and 10.16 +/- 28.05 ng.ml-1 in Group II, and 0.513 +/- 0.117 g.cm-2 and 10.75 +/- 24.94 ng.ml-1 in Group III, respectively. There was no statistical significance in BMD (P > 0.05) and iPTH(P > 0.05) among the above groups. The BMD of hemodialysis patients is not affected by different terms of hemodialysis.

Bone Density↗

PubMed1999

[Roles of sex hormones and oxygen free radical in coronary heart disease].

To examine the roles of sex hormones and oxygen free radical(OFR) in coronary heart disease (CHD), the serum estradiol(E2), testosterone(T), SOD, MDA and lipid levels were measured in 44 postmenopausal women with CHD and 22 health women. Mean levels of T and MDA were significantly higher while mean levels of SOD and E2 were significantly lower in CHD group than those in control group. On relative analysis, there was a positive correlation between E2 and SOD, while a negative correlation was observed between T and MDA in CHD group. Eighteen postmenopausal women with CHD had been receiving nilestriol replacement therapy for 12 weeks. The serum SOD and HDL-C/TC levels increased significantly, but LDL-C and MDA decreased significantly. The overall data suggest that OFR plays an important role in CHD; Low E2 levels is a risk factor of CHD in postmenopausal women; Nilestriol replacement therapy can improve the metabolism of serum lipids and inhibit lipid peroxidation, therefore, it may be of benefit to postmenopausal women with CHD.

Aged↗

PubMed1999

[Study on the relationship between plasma endothelin nitric oxide concentration and renal hypertension and renal function].

OBJECTIVE: To investigate the relationship between plasma endothelin(ET), nitric oxide(NO) levels and, renal hypertension and renal function. METHODS: The plasma concentration of ET-1 was detected by immunofluorescence assay. The plasma concentration of NO was detected by biochemistry assay. RESULTS: 1. In renal disease patients, plasma concentration ET-1 was markedly elevated, and plasma concentration of NO was decreased, compared with the healthy subjects(P < 0.01). 2. Plasma concentration of ET-1 was markedly increased and plasma concentration of NO was decreased in the patients with renal hypertension. 3. Plasma level of ET-1 was higher, and plasma level of NO was lower in the patients with renal function damage than that of those without renal function damage. 4. BP, BUN and Scr were positively correlated with plasma ET-1, but they were negatively correlated with plasma concentration of NO. CONCLUSION: Plasma ET-1 and NO may play an important role in pathogenesis of renal hypertension; the change of their levels may be related to the progress of these renal diseases.

Adult↗

PubMed1999

[Relationship between hypotension during hemodialysis and autonomic dysfunction in diabetic hemodialysis patients].

OBJECTIVE: To observe the change of autonomic nerve function in diabetes mellitus(DM) patients who receive hemodialysis and to explore the relationship between this change and hypotension during hemodialysis. METHODS: Twenty-five DM patients and 40 chronic glomerulonephritis(CGN) patients who received hemodialysis were checked. We tested their coefficient of variation R-R(CVR-R) in ECG, difference of systolic blood pressure between lying and standing positions, and serum parathyroid hormone(PTH); monitored the decrease of blood pressure during hemodialysis. RESULTS: The rate(80.0%) of autonomic dysfunction(AD) in DM group is significantly higher than that(57.5%, P < 0.05) in CGN group. The rate(37.2%) of hypotension in those who had AD was significantly higher than that(18.2%, P < 0.05) in those who had normal autonomic nerve function during hemodialysis. No significant difference was found in PTH between each group. CONCLUSION: DM patients who receive hemodialysis are often complicated with AD, which is one of the reasons that causes hypotension during hemodialysis.

Adult↗

PubMed1999

[Preliminary study of P19 gene from Bacillus thuringiensis subsp israelensis].

The P19 gene and cyt1A gene were obtained by PCR with 9.7 kb HindIII fragment containing P19 gene and cyt1A gene from 72 MD plasmid of Bt as a template. Digested PCR products were ligated to expression vector pUHE24 and transformed into E. coli XL-1. Three clones, LZ19 harboring P19 gene, LZcyt1A harboring cyt1A gene, LZ19A harboring P19 gene and cyt1A gene, were screened. The growth cure of cloned strains were determined under IPTG induction. The result showed that pLZ19 did not affect the growth of E. coli, pLZcyt1A is typically Lethal for E. coli, Lethal initial efficiency of pLZ19A is much higher than that of pLZcyt1A. Probably, this was a result that P19 gene enhanced initial expression of cyt1A gene in E. coli.

Bacillus thuringiensis↗

PubMed1999

[Establishment of a multiplex PCR system to detect plasmodium].

AIM: To establish a simple, rapid and practical multiplex PCR system to detect Plasmodium vivax(P. v) and Plasmodium falciparum(P. f). METHODS: A common upper primer S1 and two species-specific lower primers of P. v and P. f, S2, S3 were designed according to the sequences of the small subunit ribosomal DNA (SSUrDNA) fragments of the two Plasmodium species. Using these three oligonucleotide primers, the two-temperature-point multiplex PCR system was established and applied to detect P. v and P. f in the stock blood samples of clinically confirmed patients. RESULTS: DNA fragments of about 705 and 575 base pairs were successfully amplified by multiplex PCR from the genomic DNA of P. v and P. f, but no fragments were obtained from that of P. knowlesi, P. cynomolgi and blood of healthy persons. By means of restriction endonuclease digestion, the amplified fragments were confirmed to be the SSUrDNA fragments of P. v and P. f as expected. This method was successfully used in detecting parasitemia 2-10 parasite/microliter whole blood. Of 104 samples tested by this system, 81 were coincident with microscopic examination. The multiplex PCR system also found 17 samples of mixed infection, which were not detected microscopically. Another 2 samples detected as P. v by microscopic examination were verified to be P. f infection by the multiplex PCR. CONCLUSION: The ease of operation together with high sensitivity and specificity, particularly the sensitive detection for mixed infection in a single run of amplification suggests that the multiplex PCR system might be a useful tool for malaria diagnosis.

Animals↗

PubMed1999

[Excretion ratio of lactulose and mannitol as intestinal permeability index in healthy Chinese volunteers].

OBJECTIVE: To determine lactulose (L)/mannitol (M) excretion ratio with high pressure liquid chromatograph with pulsed electrochemical detection (HPLC-PED) in healthy Chinese volunteers. METHODS: Sixty healthy Chinese volunteers enrolled. For each volunteer the L/M permeability study was performed twice by two different doses, as small dose (1 g mannitol and 2 g lactulose) and regular dose (5 g mannitol and 10 g lactulose). The urine were collected during 6 hours after ingestion of the test solution. The M and L concentrations were analyzed by HPLC with pulsed electrochemical detection. RESULTS: The L/M ratio was 0.026 +/- 0.006 in the small doses tests, and 0.036 +/- 0.008 in the large doses tests. CONCLUSIONS: With HPLC-PED detection, a low doses of lactulose and mannitol can be used to study intestinal permeability. Determination of the L/M ratio may be a way of evaluating intestinal barrier function in clinical practice.

Adult↗

PubMed1999

[The effects of sex hormone on blood vessels].

OBJECTIVE: The protective mechanism of sex hormone on blood vessels was investigated to provide evidences for clinical use of hormone replacement therapy in postmenopausal women. METHODS: To observe the effects of 17 beta-estradiol (E2), progesterone(P), testosterone (T) and E2 combined with P on the relaxation of umbilical arterial rings (UAR) as well as production of nitric oxide (NO) in cultured umbilical endothelial cells(HUVEC) in vitro. RESULTS: The results showed that 10(-9)-10(-6) mol/L E2 dilation of UAR, but 10(-5) mol/L E2 showed vague effect. P or T had no relaxation effect, but releasing nitric oxide. When in combined trial P at 10(-5) mol/L inhibited the relaxation effect of E2 at 10(-7)-10(-5) mol/L but didn't inhibit E2 10(-9) mol/L. In HUVEC 10(-9)-10(-5) mol/L E2 stimulated the release of nitric oxide when cells incubated for 10 min and 30 min, but did not influence the NO release at 60 min. P and T have different effects on the release of nitric oxide at different concentrations and incubation time. P also inhibited the NO release induced by E2. CONCLUSIONS: The results indicated that P actually inhibited the relaxation response and induction of NO release by E2, especially at the high concentration. Therefore, we suggested that to use low doses of E2 combined with low dose P for hormone replacement therapy in prevention and treatment of cardiovascular diseases in postmenopausal patient.

Cells, Cultured↗