Biomedical subjects

F Sun

Publications and source records attributed to F Sun.

At least 55 records · Page 3Linked to original sources

PubMed2000

[The application of auro-galvano-form ceramic crowns in clinic].

OBJECTIVE: To evaluate the effects of auro-galvano-form ceramic crown in clinic. METHODS: The Ni-Cr alloy high-gold alloy and auro-galvano-form ceramic crowns were made respectively. Every kind was 200 pieces. 600 piece crowns were in total for 298 patients. The color of ceramic crowns was checked with Shade Eye. The color, fitness and fracture of ceramic crowns were checked in clinic. RESULTS: The results showed the aurogalvano-form ceramic crowns was similar to high-gold alloy ceramic crowns in color and fitness in clinic (P > 0.05). The effects of them were better than Ni-Cr alloy ceramic crowns in color and fitness significantly (P < 0.05). The fracture of 600 ceramic crowns was not found out in two years. CONCLUSIONS: The effects of auro-galvano-form ceramic crowns were perfect in color, fitness and fracture. It can be used in clinic.

Adolescent↗

PubMed2000

[Effect of acupuncture on level of monoamines and activity of adenosine triphosphatase in lateral hypothalamic area of obese rats].

OBJECTIVE: To study the mechanism of acupuncture in treating simple obesity. METHODS: Central nerve push-pull perfusion and biochemical technique were used to observe the effect of acupuncture on obese rats, and the obese parameters and the change of monoamine transmitters and activity of ATPase in the lateral hypothalamic area (LHA) of the obese rats were investigated. RESULTS: The levels of noradrenaline (NA) in LHA of obese rats were higher than those in the normal group, but the level of serotonin (5-HT) and the activity of ATPase in LHA of obese rats were lower than those of the normal rats. After acupuncture treatment, the weight of the obese rats reduced, while the level of NA in LHA reduced and the 5-HT and activity of ATPase increased (P < 0.05, P < 0.01). CONCLUSION: The effective regulation on LHA of obese rats is possibly one of the key factors in the anti-obesity of acupuncture.

Acupuncture↗

PubMed2000

[Effect of tiangui recipe on expressions of hypothalamic leptin receptor and messenger ribonucleic acid of neuropeptide Y in androgen-sterilized rats].

OBJECTIVE: To explore the effect of Tiangui Recipe (TGR) on obesity and anovulation in androgen-sterilized rats (ASR) from the gene transcription level. METHODS: In situs hybridization and autoradiography were adopted, using alpha-32 P-radiolabelled leptin receptor (OB-R) and neuropeptide Y (NPY) oligonucleotides probes and integrating with image pattern analysis, to observe the effect of TGR on changes of OB-R, NPY mRNA expression in the hypothalamic arcuate nucleus (ARC). RESULTS: Compared to the normal rats, the levels of hypothalamic OB-R mRNA expression decreased, NPY mRNA expression elevated significantly in ASR (P < 0.01). ASR characterized by obesity and anovulation. There was no significant difference in hypothalamic OB-R, NPY mRNA expressions between normal rats and ASR with TGR administration. CONCLUSION: The increased hypothalamic NPY and decreased OB-R mRNA expression may be important contributing factors to the development of obesity and anovulation in ASR. TGR may play a role in reducing weight and inducing ovulation by regulating NPY/OB-R mRNA expression.

Animals↗

PubMed2000

[Surgical approaches of pheochromocytoma].

OBJECTIVE: To evaluate the effects of surgery of Pheo. METHODS: Pheochromocytoma was removed in 89 patients. RESULTS: In 39 patients, pheochromocytoma was removed by intercostal incision at the 11th rib and 15 at the 10th rib, 14 by transrectal incision, 9 by abdominothoracic incision, 5 by abdominal subcostal oblique incision, 3 by inferior abdominal incision, 3 by posterolateral incision. One patient received laparoscopic surgery. CONCLUSIONS: Pheochromocytoma definitely localized was removed by intercostal incision at the 10th or 11th rib. The suitable pathway for removal giant pheochromocytoma or pheochromocytoma related big vessels is transrectal incision or abdominothoracic incision. The incision of multiple pheochromocytoma or extra-adrenal pheochromocytoma may be in the middle of the abdomen.

Abdomen↗

PubMed2000

[Diagnosis and treatment of pheochromocytoma].

OBJECTIVE: To improve the diagnosis and treatment of pheochromocytoma. METHODS: From 1958 to 1998, 286 cases of pheochromocytoma, confirmed by open surgery and pathology, were retrospectively analyzed. RESULTS: The tumors in the adrenal gland were seen in 220 cases, and in the external adrenal gland in 66. Of 29 cases of malignant pheochromocytomas, 7 were noted in the adrenal and 22 in the external adrenal gland. 19 cases showed stationary pheochromocytomas without clinical features. Total resections were performed in 281 cases. CONCLUSION: The operative mortality could be reduced by the prevention of potential myocardiopathy. The diagnosis of malignant pheochromocytoma should depend upon the long-term follow up.

Adolescent↗

PubMed2000

[Study on the protective effect of grape procyanidins on DNA damage induced by irradiation].

OBJECTIVE: To study the protective effect of grape procyanidins (GPC) on the irradiated DNA damage. METHOD: In vivo study: After orally administration of GPC, mice in different groups were exposed to whole-body (60)Co gamma-rays at a dose of 2.0 Gy and the fluorospectrometry method was used to rapidly detect the DNA strand breaks of mouse spleen cells. In vitro study: Human venous blood with different concentrations of GPC was exposed to (60)Co gamma-rays at a dose of 1.0 Gy, then WBC DNA content was measured after 1, 30 and 60 min exposure, respectively. RESULTS: In the three treated groups (500, 250 and 50 mg/kg of procyanidins), DNA content of mouse spleen cells was 18.76%, 15.74% and 5.06% more than that of the positive controls respectively. DNA content of human WBC was higher than the positive controls by 17.6%, 11.1% and 3.9% increase respectively one minute after irradiation and 21.3%, 13.8% and 5.3% increase respectively 60 min after irradiation. These differences were all statistically significant. CONCLUSION: GPC has a protective effect on DNA damage caused by irradiation, and is helpful to DNA repair.

Animals↗

PubMed1999

Increase of caspase-3 activity in rat liver and plasma by thioacetamide.

Twelve and twenty-four hours after intraperitoneal administration of thioacetamide (200 mg/kg body weight) to rats, caspase-3 activity in the liver and plasma of the treated rats increased significantly compared with that of the control group. These results demonstrated that thioacetamide caused apoptosis, which involved activation of caspase-3, although there may be a number of pathways to apoptosis in the liver that may or may not involve the activation of this protein. The results also indicated that the activated caspase-3 was released in plasma along with glutamate-oxaloacetate transaminase (GOT) by successive necrosis. This is the first study that shows an increase of caspase-3 activity in plasma.

Animals↗

PubMed1999

Transmission disequilibrium test (TDT) when only one parent is available: the 1-TDT.

The transmission disequilibrium test (TDT) is a useful method to locate mutations linked to disease genes associated with complex diseases. TDT requires genotypes of affected individuals and their parents. Recently, Ewens and Spielman (Am J Hum Genet 1998;62:450-8) extended the TDT for use in sibships with at least one affected and one unaffected individual and devised a new test called the sib transmission/disequilibrium test (S-TDT). The S-TDT can be applied to diseases with late age at onset such as non-insulin-dependent diabetes mellitus, psychiatric disorders, and diseases related to aging. For some disorders, it might be relatively easy to obtain the genotype of one parent either because the other parent is not available for study or he/she is not cooperative. Curtis and Sham (Ann Hum Genet 1995;59:323-36) showed that bias in transmitting certain alleles is introduced if only heterozygous parents and homozygous offspring are used in the TDT. In this paper, the authors propose a new test, the 1-TDT, to detect linkage between a candidate locus and a disease locus using genotypes of affected individuals and only one available parent for each affected individual. The test is not biased under the null hypothesis of no linkage or association. The authors validate their test using both simulated and real data sets. Finally, they show how to combine data from different types of families.

Age of Onset↗

PubMed1999

Comparison of arithmetic and geometric means as measures of a central tendency in cattle nematode populations.

Efficacy calculations in anthelmintic studies require estimates of the central tendency for the nematode populations. Confusion exists among practitioners regarding which measures of central tendency are most appropriate; although the arithmetic mean is frequently used, there are theoretical reasons for preferring the geometric mean. To investigate this controversy, arithmetic and geometric means were compared for their suitability for use in measuring efficacy. Arithmetic and geometric means were compared as measures of central tendency for skewed distributions. The following criteria were developed to facilitate the comparison: (1) probability around the parameter, (2) influence of extreme values, and (3) proximity to the median. Under log-normality, theoretical results demonstrated the superiority of the geometric mean. Modified-bootstrap simulations using empirical data from cattle were used to confirm theoretical expectations. Simulations on log-normal data supported the geometric mean as the better indicator of the central tendency. Additionally, for data not confirmed as log-normal, the superiority of geometric means was demonstrated. In a comparison of precision, it was shown that mean squared error was always smaller for sample geometric means than for arithmetic means when n> or =2. Simulation results added support to that conclusion.

Animals↗

PubMed1999

Using case-control designs for genome-wide screening for associations between genetic markers and disease susceptibility loci.

We used a case-control design to scan the genome for any associations between genetic markers and disease susceptibility loci using the first two replicates of the Mycenaean population from the GAW11 (Problem 2) data. Using a case-control approach, we constructed a series of 2-by-3 tables for each allele of every marker on all six chromosomes. Odds ratios (ORs) and 95% confidence intervals (95% CI) were estimated for all alleles of every marker. We selected the one allele for which the estimated OR had the minimum p-value to plot in the graph. Among these selected ORs, we calculated 95% CI for those that had a p-value < or = adjusted alpha level. Significantly high ORs were taken to indicate an association between a marker locus and a suspected disease-susceptibility gene. For the Mycenaean population, the case-control design identified allele number 1 of marker 24 on chromosome 1 to be associated with a disease susceptibility gene, OR = 2.10 (95% CI 1.66-2.62). Our approach failed to show any other significant association between case-control status and genetic markers. Stratified analysis on the environmental risk factor (E1) provided no further evidence of significant association other than allele 1 of marker 24 on chromosome 1. These data indicate the absence of linkage disequilibrium for markers flanking loci A, B, and C. Finally, we examined the effect of gene x environment (G x E) interaction for the identified allele. Our results provided no evidence of G x E interaction, but suggested that the environmental exposure alone was a risk factor for the disease.

Alleles↗

PubMed1999

Whole genome association studies for genes affecting alcohol dependence.

We applied the transmission/disequilibrium test (TDT) for sibs (S-TDT) and for families with one parent (1-TDT), to the Collaborative Study on the Genetics of Alcoholism data set. The combined test is used to screen the whole genome to locate genes responsible for alcohol dependence. This analysis supports the previous finding that the region close to GABRB1 on chromosome 4 might be associated with alcohol dependence. The regions close to D6S474 and D11S1998 are also of particular interest. We found segregation distortion at the GR1K1 locus. The segregation distortion might be due to the binning method used in genotyping at this locus.

Alcoholism↗

PubMed1999

Association of genetic polymorphisms of alcohol-metabolizing enzymes with excessive alcohol consumption in Japanese men.

To evaluate the independent and interactive contributions of alcohol dehydrogenase-2 (ADH2), aldehyde dehydrogenase-2 (ALDH2) and ethanol-induced isozyme cytochrome P450-2E1 (CYP2E1) genes to alcohol consumption large enough to induce health problems, 643 healthy Japanese men aged between 23 and 64 years, recruited from two different occupational groups, were analyzed for genotype and drinking habits. The frequency of excessive alcohol consumers (EAC) who drank 90 ml or more alcohol more than 3 days a week was significantly higher in subjects possessing the ALDH2(1)/ALDH2(1) genotype than in those having ALDH2(1)/ALDH2(2) or ALDH2(2)/ALDH2(2) genotypes. A significant difference was also found in the different genotypes of CYP2E1. Moreover, a borderline significant interaction between the ALDH2 and CYP2E1 genotypes on excessive alcohol consumption was observed, i.e., the group of subjects having the c2 allele of CYP2E1 had a higher frequency of EAC than those having c1/c1 genotypes in the genotype subgroup ALDH2(1)/ALDH2(1), whereas these were not found in the heterozygote and homozygote subgroups of the ALDH2(2) allele. Neither the independent nor interactive genetic effect of ADH2 on excessive alcohol consumption was obvious. In conclusion, Japanese men with the ALDH2(1)/ALDH2(1) genotype and the c2 allele of CYP2E1 are at higher risk of showing excessive alcohol consumption.

Adult↗

PubMed1999

Genome-wide scanning for type 2 diabetes susceptibility in Canadian Oji-Cree, using 190 microsatellite markers.

We undertook a genome-wide scan using 190 markers with an average separation of 20 cM in 49 Canadian Oji-Cree sib pairs affected with type 2 diabetes. Four of these markers, one each on chromosomes 6, 8, 16, and 22, showed both suggestive linkage and suggestive association with type 2 diabetes in the Oji-Cree. None of these markers corresponded to any chromosomal region or marker that has so far been linked with type 2 diabetes in other populations. Thus, there might be several genetic loci that confer susceptibility to type 2 diabetes in this study sample. We are following up on these preliminary leads by increasing the density of the markers within these linked and associated regions, and also by increasing the number of study subjects. Also, we found instances in which there were wide disparities between the Oji-Cree and reference Caucasians with respect to marker heterozygosity. This suggests that a particular set of markers for genome-wide scanning will have different informativeness in different ethnic groups. Thus, different marker sets will likely be required for different ethnic groups in order to maximize their information content for linkage calculations.

Adult↗

PubMed1999

Modeling DNA shuffling.

In vitro evolution is a new, important laboratory method to evolve molecules with desired properties. It has been used in a variety of biological studies and drug development. In this paper, we study one important mutagenesis method used in in vitro evolution experiments called DNA shuffling. We construct a mathematical model for DNA shuffling and study the properties of molecules after DNA shuffling experiments based on this model. The model for DNA shuffling consists of two parts. First we apply the Lander-Waterman model for physical mapping by fingerprinting random clones to model the distribution of regions that can be reassembled through DNA shuffling. Then we present a model for recombination between different DNA species with different mutations. We compare our theoretical results with experimental data. Finally we propose novel applications of the theoretical results to the optimal design of DNA shuffling experiments and to physical mapping using DNA shuffling.

Base Sequence↗

PubMed1999

Miscarriage prevention tea affects plasma beta-endorphin concentrations in women with early threatened abortions.

Twenty threatened abortive patients in the 7-8th week of gestation were treated with a classical miscarriage prevention tea (Shou-Tai-Tang) combined with psychological consultation. All of the patients had a history of unexplained recurrent abortions. This treatment succeeded in sixteen out of 20 patients. The plasma concentrations of beta-endorphin (beta-EP), gonadotrophin releasing hormone (GnRH), human chorionic gonadotrophin (hCG), and progesterone (P4) were measured by radioimmunoassay before and after treatment. Compared to control subjects, beta-EP levels were significantly higher, while GnRH, hCG, and P4 were lower than before treatment. Concentrations of these peptides/hormones returned to normal ranges after successful treatment.

Abortion, Spontaneous↗

PubMed1999

Case-only design to measure gene-gene interaction.

The case-only design is an efficient and valid approach to screening for gene-environment interaction under the assumption of the independence between exposure and genotype in the population. In this paper, we show that the case-only design is also a valid and efficient approach to measuring gene-gene interaction under the assumption that the frequencies of genes are independent in the population. Just as the case-only design requires fewer cases than the case-control design to measure gene-environment interaction, it also requires fewer cases to measure gene-gene interactions.

Epidemiologic Studies↗

PubMed1999

[Effect of tiangui recipe on serum leptin and pituitary gonadotropin in androgen-sterilized rats].

OBJECTIVE: To explore the effect of Tiangui Recipe (TGR) on obesity and reproductive function in androgen-sterilized rats (ASR). METHODS: ASR model was established by subcutaneous injection of testosterone propionate to SD female rats of 9 days age. Change of serum leptin, follicle-stimulating hormone (FSH) and luteinizing hormone (LH) in model rats of 115 days old before and after feeding TGR was measured by radioimmunoassay (RIA). Meanwhile, criteria of energy state, including diurnal food intake, retroperitoneal fat depot weight and body weight, were measured and evaluated. RESULTS: ASR had the characteristics of high metabolic rate, energy imbalance and obesity. Serum level of leptin increased and FSH, LH decreased significantly (P < 0.01) in model rats as compared with the normal rats. Significant positive correlation between leptin level and body weight (r = 0.8977, P < 0.001) was observed, and negative correlation was seen between FSH, LH and leptin (r = -0.7517, P < 0.001; r = -0.8444, P < 0.001, respectively). The endocrinous changes of ASR all returned to normal range after the TGR treatment. CONCLUSION: Obesity and concerned hypogonadotropic hypogonadal anovulation were expressed in ASR. TGR may play an important role in reducing weight and inducing ovulation.

Androgens↗

PubMed1999

[Effect of TCM on plasma beta-endorphin and placental endocrine in threatened abortion].

OBJECTIVE: To explore the effect of TCM on plasma beta-endorphin (beta-EP) and placental endocrine function in patients of threatened abortions (TA). METHODS: Changes of plasma beta-EP, gonadotrophin releasing hormone (GnRH), human chorionic gonadotrophin (HCG), progesterone (P4) levels were measured with RIA in 40 cases of TA with a history of recurrent spontaneous abortion treated with Chinese herbal medicine for reinforcing Kidney and Qi, hemostasis and antiabortion. And the results were compared with those of normal early pregnant women and patients with incomplete abortion as control. RESULTS: The plasma beta-EP level in TA was significantly higher than that in normal pregnant women, P < 0.01. On the contrary, plasma GnRH, HCG and P4 were obviously lower in TA as compared with those of the normal cases, P < 0.01. After treatment, 36 of the 40 patients succeeded in the continuity of pregnancy, their symptoms of TA disappeared, and the above-mentioned four criteria measured at 10-12th week of gestation were similar to those of normal cases, P > 0.05. CONCLUSION: TCM treatment can regulate plasma beta-EP and placental endocrine function in threatened abortion.

Abortion, Threatened↗