PubMed Health⌕ Search

Biomedical subjects

F Sun

Publications and source records attributed to F Sun.

At least 73 records · Page 4Linked to original sources
PubMed1999

[Location of the binary toxin gene of Bacillus sphaeriucs and some biological characteristics of its asprogenous mutants].

Location of the binary toxin gene of Bs C3-41 and some biological characteristics of its asporogenous mutants which obtained by DES treatment were studied in this paper. Mutant C4, L5 with blocked at the stage II of sporulation course were not possessed of any crystalline inclusion, but the binary toxin proteins were detected in their cells by SDS-PAGE analysis. Another mutant G5 which blocked at the stage III of sporulation course formed parasporal crystal in the cells, and its toxicity to larvae of Culex quinquefasciatus was about 50 times higher than those of mutant C4 and L5. The result of curing plasmid and Southern blot analysis confirm the binary toxin gene of Bs C3-41, Bs 1691 and Bs-10 locate on the chromosome.

Animals↗
PubMed1999

Change in tissue concentrations of lipid hydroperoxides, vitamin C and vitamin E in rats with streptozotocin-induced diabetes.

The tissue concentration of lipid hydroperoxides, which was determined by a specific method involving chemical derivatization and HPLC, increased significantly in the heart, liver, kidney and muscle of diabetic rats 8 weeks after the intraperitoneal injection of streptozotocin compared with that of the control group. These results demonstrate that an enhanced oxidative stress is caused in these tissues by diabetes. Vitamin C concentrations of the brain, heart, lung, liver, kidney and plasma of the diabetic rats decreased significantly after 8 weeks compared with those of the control group. Vitamin E concentrations of the brain, heart, liver, kidney, muscle and plasma of the diabetic rats increased significantly after 4 weeks compared with the control group. After 8 weeks, an elevation in vitamin E concentration was observed in the heart, liver, muscle and plasma of the diabetic rats.

Analysis of Variance↗
PubMed1998

The alternation of optokinetic responses driven by moving stimuli in humans.

When the two eyes were exposed dichoptically to two oppositely moving patterns, the alternating OKN was elicited, in which the eye movements tracked the two moving stimuli alternately. In the present experiment, two oppositely moving stimuli were periodically exchanged between the eyes, the results showed that the alternation of OKN direction was not affected by this exchange. It suggests that alternating OKN was not controlled by rivalry between the two eyes but between two perceived motion patterns.

Functional Laterality↗
PubMed1998

A new method for estimating the risk ratio in studies using case-parental control design.

The authors describe a new simple noniterative, yet efficient method to estimate the risk ratio in studies using case-parental control design. The new method is compared with two other noniterative methods, Khoury's method and Flanders and Khoury's method, and with a maximum likelihood-based method of Schaid and Sommer. The authors found that the variance of the new estimation method is usually smaller than that of Khoury's method or Flanders and Khoury's method and that it is slightly larger than that of the maximum likelihood-based method of Schaid and Sommer. Despite the slightly large variance of the new estimator compared with that of the maximum likelihood-based method, the simplicity of the new estimator and its variance makes the new method appealing. When genotypic information for only one parent is available, the authors also describe a method to estimate the risk ratio without assuming Hardy-Weinberg equilibrium or random mating. A simple formula for the variance of the estimator is given.

Alleles↗
PubMed1998

Higher T-wave amplitude associated with better prognosis in patients receiving thrombolytic therapy for acute myocardial infarction (a GUSTO-I substudy). Global Utilization of Streptokinase and Tissue plasminogen Activator for Occluded Coronary Arteries.

Increased T-wave amplitude is one of the earliest electrocardiographic (ECG) changes following coronary artery occlusion. Therefore, higher T waves in the presenting electrocardiogram should represent earlier time to treatment and thus be associated with lower mortality following thrombolytic therapy. However, T-wave amplitude has never been evaluated as a prognostic marker in this setting. We examined clinical outcomes in 3,317 patients with acute myocardial infarction (AMI) who underwent thrombolysis in the Global Utilization of Streptokinase and t-PA for Occluded Coronary Arteries (GUSTO-I) Study. Patients were classified as either those with high T waves or those with low T waves. Higher T waves were defined as those >98th percentile of the upper limit of normal. T-wave amplitude was also evaluated as a continuous variable according to infarct location (maximum T-wave amplitude) and as the amount of excess T-wave amplitude above normal (excess T-wave amplitude). Patients with higher T waves had lower 30-day mortality than those without (5.2% vs 8.6%, p = 0.001) and were less likely to develop congestive heart failure (15% vs 24%, p <0.001) or cardiogenic shock (6.1% vs 8.6%, p = 0.023). Higher maximum T-wave amplitude and excess T-wave amplitude were predictive of lower 30-day mortality (chi-square = 67, p <0.001 and chi-square = 33, p <0.001, respectively). These differences remain significant after controlling for other prognostic baseline ECG variables. In addition, T-wave amplitude added prognostic significance after controlling for time to treatment. T-wave amplitude, an often-overlooked component of the electrocardiogram, can add significant prognostic information in initial evaluation of patients with AMI.

Aged↗
PubMed1998

Testing for contributions of mitochondrial DNA mutations to complex diseases.

Several complex disorders are suspected of being associated with mitochondrial DNA (mtDNA) mutations. We studied the statistical properties of a test based on proband-relative pairs to identify potential mtDNA mutation involvement in a complex disorder. The test compares the recurrence risk of relatives of probands along the mitochondrial lineage with that of relatives along the nonmitochondrial lineage. If mtDNA mutations are involved, the recurrence risk will be higher among relatives in the mitochondrial lineage. The form of the test is independent of the assumed models of inheritance and interaction of the nuclear autosomal mutations with mtDNA mutations. The power of the test, however, differs among the different models and by the type of proband-relative pairs used in the test. We considered heterogeneity models with and without phenocopies, a three-state heteroplasmic mtDNA transmission model, and a multiplicative epistasis model. Under the heterogeneity model, the power of the test increases as the relationship between the proband and the relative becomes more distant. Under the multiplicative epistasis model, the power of the test decreases as the relationship between the proband and the relative becomes more distant.

DNA, Mitochondrial↗
PubMed1998

Neural network mosaic model for pupillary responses to spatial stimuli.

A neural network mosaic model was developed to investigate the spatial-temporal properties of the human pupillary control system. It was based on the double-layer neural network model developed by Cannon and Robinson and the pupillary dual-path model developed by Sun and Stark. The neural network portion of the model received its input from a sensor array and consisted of a retina-like two-dimensional neuronal layer. The dual-path portion of the model was composed of interconnections of the neurons that formed a mosaic of AC transient and DC sustained paths. The spatial aggregates of the AC and DC signals were input to the AC and DC summing neurons, respectively. Finally, the weighted sum of the aggregate AC and DC signals provided the output for driving the pupillary response. An important property of the model was that it could adaptively learn from training samples by adjustment of the weights. The neural network mosaic model showed excellent performance in simulating both the traditional pupillary phenomena and the new spatial stimulation findings such as responses to change in stimulus pattern and shift of light spot. Moreover, the model could also be used for the diagnosis of clinical deficits and image processing in machine vision.

Brain Stem↗
PubMed1998

-6A promoter variant of angiotensinogen and blood pressure variation in Canadian Oji-Cree.

We previously reported significant associations between variation in the AGT gene at codon 235 and both systolic pressure and hypertension in Canadian Oji-Cree. Recently, Inoue et al suggested that the AGT T235 variant was not causative, but was rather in linkage disequilibrium with a variant in the AGT promoter, namely -6A, that was associated with increased in vitro expression of angiotensinogen and was thus a strong candidate to be the functional basis of the previously observed associations. We genotyped 518 adult Oji-Cree for the AGT promoter polymorphism and tested for its association with blood pressure and hypertension. We found that the frequency of the -6A variant was 0.85 in the Oji-Cree, which is much higher than the frequency observed in other human samples. We also found strong linkage disequilibrium between the AGT -6A and T235 variants. However, genetic variation of the AGT promoter was only marginally associated with variation in systolic pressure, with a trend to significantly higher systolic pressure seen in AGT -6A/A homozygotes than in subjects with other genotypes. In addition, genetic variation of the AGT promoter tended to be associated with a diagnosis of hypertension. Despite the very high prevalence of -6A, our native sample was essentially normotensive. Our findings are consistent with a marginally deleterious effect of the AGT -6A allele on blood pressure, but linkage disequilibrium with another causative variant cannot be ruled out in this sample of aboriginal Canadians.

Adult↗
PubMed1998

Seven new microcystins possessing two L-glutamic acid units, isolated from Anabaena sp. strain 186.

Electrospray ionization mass spectrometry has been applied to the structure assignment of seven new microcystins (1-7), obtained from cultured Anabaena sp. strain 186. The seven new microcystins contain the dehydroalanine (Dha) or L-Ser unit instead of the N-methyldehydroalanine unit and the L-Glu and/or its delta-methyl ester [E(OMe)] units at the two variable L-amino acid units, and the structures were assigned as [Dha7]microcystin-E(OMe)E(OMe) (1), [D-Asp3,Dha7]microcystin-E(OMe)E(OMe) (2), [L-Ser7]microcystin-E(OMe)E(OMe) (3), [D-Asp3,L-Ser7]microcystin-E(OMe)E(OMe) (4), [Dha7]microcystin-EE(OMe) (5), [D-Asp3,Dha7]microcystin-EE(OMe) (6), and [L-Ser7]microcystin-EE(OMe) (7). These microcystins are the first examples containing dicarboxylic amino acids at the two variable L-amino acid units in microcystins.

Anabaena↗
PubMed1998

Increase of lipid hydroperoxides in the rat liver and kidney after administering ferric nitrilotriacetate.

Two hours after an intraperitoneal injection of ferric nitrilotriacetate to rats at a dose of 15 mg of Fe/kg of body weight, the level of lipid hydroperoxides, which was determined by a specific method involving chemical conversion into 1-naphthyldiphenylphosphine oxide and HPLC, had increased significantly in the liver (from 190.1 +/- 58.8 of the control to 467.1 +/- 175.8 pmol/mg of protein) and kidney (from 181.8 +/- 52.3 of the control to 405.9 +/- 22.7 pmol/mg of protein). These results demonstrate that oxidative stress was transiently increased by an iron overload in these tissues.

Animals↗
PubMed1998

Application of acupuncture and moxibustion for keeping shape.

On the basis of TCM diferentiation, the authors have treated 359 adult female cases of non-obesity with undesirable body shape by combined application of body acupuncture and moxibustion and auricular acupuncture, and achieved quite good remoulding and orthopedic results, suggesting that acupuncture and moxibustion can very effectively regulate the somatotypic indexes of body weight, circumference of the chest, loin, hip and thigh, the ratio of the loin to hip, sebum thickness, obesity degree, body mass index and body fat percentage of the cases in the overweight group and orthopedic groups 1, 2. It is therefore concluded that acupuncture and moxibustion is a good therapy for obtaining a graceful body shape.

Acupuncture Therapy↗
PubMed1998

[Emergency measures on drinking water sanitation for mitigation of flood and waterlogging disasters].

This article reports the emergency measures for mitigation during flood and waterlogging disasters to ensure drinking water sanitation and to prevent infectious disease outbreaks. Five preparatory and preventive measures for flood and waterlogging disasters include the construction of dual-purpose water supply installation for ordinary and disaster use, the storage of qualified technicians and materials (or their inventories), and the formulation of predetermination programme for disaster relief, ect.

China↗
PubMed1998

[Magnetic resonant imaging diagnosis and differential diagnosis in choroidal melanoma].

OBJECTIVE: To evaluate the diagnostic value of magnetic resonant imaging (MRI) for choroidal melanoma. METHODS: 12 cases of choroidal melanoma were diagnosed by means of B-ultra-sonography, computed tomography (CT), MRI and pathology. RESULTS: The MRI features of melanoma were: T(1)WI shows high signal, and T(2)WI shows low signal. CONCLUSION: Besides B-ultra-sonography and CT, MRI is also valuable in the diagnosis and differential diagnosis of choroidal melanoma.

Adult↗
PubMed1998

[The manifestations of 496 cases with thyroid-related immune orbitopathy and normal thyroid function].

OBJECTIVE: To observe the clinical manifestations of thyroid-related immune orbitopathy (TRIO) with normal thyroid function. METHODS: 496 cases with TRIO were collected from 1973 to 1994 and their clinical manifestations were analyzed. RESULTS: The clinical manifestations showed that males are more than females. The disease occurred in middle aged persons with unilateral exophthalmos as the primary early manifestation. Most of the cases had the signs of eyelids and extraocular muscle involvement. CONCLUSIONS: The thyroid-related immune orbitopathy with normal thyroid function can be named thyroid-related immune orbitopathy-II. The clinical characteristics of this disease are unilateral, of signs of eyelids, exophthalmos and enlargement of eye muscles. The pseudo-tumors of the orbit are mainly considered for differential diagnosis.

Adolescent↗
PubMed1998

[A study of cytokines in pathogenesis of thyroid-related immune orbitopathy].

OBJECTIVE: To explore the pathogenesis of thyroid-related immune orbitopathy (TRIO). METHODS: Human orbital fibroblasts were cultured in vitro and immunohistochemical techniques were used to study cytokines that induce effect on HLA-II antigen expression of orbital fibroblasts. RESULTS: It is shown that interferon-gamma (IFN-gamma), interleukin-1 (IL-1) and tumor necrosis factor (TNF) could induce the expression of orbital fibroblast HLA-II antigens. The induced effect of IFN-gamma is of good linear correlations with time and concentration. CONCLUSION: HLA-II antigen expression can be induced by IFN-gamma, IL-1 and TNF. In the course of immune reaction and pathogenesis of TRIO, cytokines play important roles.

Cytokines↗
PubMed1997

Sequential sib-pair and association studies to detect genes in quantitative traits.

We applied sib-pair and association methods to a GAW data set of nuclear families with quantitative traits. Our approaches included 1) preliminary statistical studies including correlations and linear regressions, 2) sib-pair methods, and 3) association studies. We used a single data set to screen for linkage and association and, subsequently, additional data sets to confirm the preliminary results. Using this sequential approach, sib-pair analysis provided evidence for the genes influencing Q1, Q2, and Q4. We correctly predicted MG1 for Q1, MG2 for Q2, and MG4 for Q4. We did not find any false positives using this approach. Association studies identified chromosomes 8 and 9 to be associated with Q4; however these are assumed to be false positives as no associations were modeled into the data.

Analysis of Variance↗
PubMed1997

The method of sib-pair linkage analysis in context of case-control design.

We used sib-pair linkage analysis as part of an epidemiologic approach to solving Problem 2 of the GAW10 data set of nuclear families. We recoded the quantitative trait Q1 into a dichotomous trait using Q1 > or = 40 as the cut-point. In a case-control design of sib-pair analysis, the affected siblings of the proband were the case subjects and the unaffected siblings were the control subjects. Case and control subjects were compared with respect to the number of alleles at one or more loci (0, 1, 2) that were identical-by-descent (IBD) with those of the proband. Odds ratios (ORs) and 95% confidence intervals (95% CI) were then computed with subjects sharing no alleles (share-0) serving as the reference group. Significantly high ORs were taken as indication of linkage between a marker locus and a suspected disease-susceptibility locus. The case-control sib-pair analysis identified marker D5G15 as associated with disease susceptibility (OR of sharing two alleles [share-2] = 7.7 [95% CI 2.5-23.9]). Our results were consistent with the results from Kruglyak and Lander's method of complete multipoint sib-pair analysis for linkage. For the marker (D5G15) identified through sib-pair analysis, we examined the effects of other covariates and evaluated gene-environment interaction using conditional logistic regression.

Case-Control Studies↗