Biomedical subjects

C Sun

Publications and source records attributed to C Sun.

At least 55 records · Page 3Linked to original sources

PubMed2001

[Expression of rasp21, C-myc, C-erbB-2, and AFP in 2-FAA induced experimental hepatocarcinogenesis].

OBJECTIVE: To investigate the distribution of oncogenes and their relationships in 2-FAA induced experimental hepatocarcinogenesis. METHODS: Rasp21, C-myc, C-erbB-2, and AFP were detected and analyzed by the SP method of immunohistochemistry. RESULTS: Some cells expressed rasp21, C-myc, and AFP in peripheral liver lobules and alternated hepatocyte foci in the early stage of the experiment. And with the formation and progression of hyperplastic hepatocytic nodules, expressed cells increased and often accompanied each other. Expression of C-erbB-2 appeared in the middle stage of the hepatocarcinogenesis. CONCLUSIONS: Expression of rasp21, C-myc, and AFP in the experimental hepatocarcinogenesis is an early molecule change, which may relate to the initiation of hepatocarcinogenesis and be considered to be one of the molecular bases for the morphogenesis of hepatocarcinogenesis. During the development of lesion, C-erbB-2 may have promoting effects. It is also clear that malignant transformation of hepatocyte needs the cooperation of multiple oncogenes.

2-Acetylaminofluorene↗

PubMed2001

[Construction of plant expression vectors harboring a peptide antibiotic-apidaecin gene and resistance analysis of the transgenic tobacco].

Two plant expression vectors(pBinPRHbI and pBinPRSIHbI) were constructed: Firstly, apidaecin gene were fused to the signal peptide coding sequencing of a PR-protein, and cloned into a binary vector pBin438 to form pBinPRHbI. Then, the cassette consisting of 35S promoter, PR signal peptide coding sequencing and apidaecin gene was cut off from pBinPRHbI and inserted into another plant expression vector pBinPRSI to produce a bivalent plant expression vector pBinPRSIHbI. pBinPRSI was constructed previously in our lab and contained PR signal peptide and Shiva-I fusion gene under control of 35S promoter. The three plant expression vectors were introduced into tobacco by Agrobacterium-mediated transformation. The positive rate of PCR was 95% in all putative transgenic plants. Results from Southern blot indicated that foreign genes were integrated into tobacco genome and RT-PCR analysis proved that the foreign gene was transcribed in transgenic tobacco. The transgenic tobacco showed higher resistance to P. syringae pv tabaci, the causal agent of tobacco wild fire disease, than their original cultivars. From the disease index, the transgenic plants carrying apidaecin and Shiva-I genes had highest resistance among three kinds of transgenic plants, and the plants carrying Shiva-I gene alone had lowest resistance.

Anti-Infective Agents↗

PubMed2001

[Study on the effects of leptin on puberty development in children].

OBJECTIVE: To study the effects of leptin on puberty development in children. METHODS: Three hundred obese and 300 healthy children without taking any medication or having evidence of endocrine or metabolic diseases were studied. Their ages of first spermatorrhea and menarche were surveyed, and blood levels of leptin, sex hormones, growth hormone (GH) and insulin (INS) were measured. RESULTS: With increased of age, blood levels of leptin appeared from low to high and from high to low again in the boys, with (1.04 +/- 0.21) nmol/L to (1.20 +/- 0.27) nmol/L and to (0.66 +/- 0.10) nmol/L in the obese group, and with (0.31 +/- 0.06) nmol/L to (0.45 +/- 0.10) nmol/L and to (0.19 +/- 0.04) nmol/L in the control group. While blood level of leptin appeared an increasing trend in girls, with (0.89 +/- 0.15) nmol/L to (1.39 +/- 0.23) nmol/L in the obese group, and (0.46 +/- 0.08) nmol/L to (0.88 +/- 0.18) nmol/L in the control group. Levels of sex hormones also appeared an increasing trend in the all groups. Levels of GH showed an abrupt increased at certain ages, different in boys from girls (14-15 years of age in boys and 13-14 in girls). In the all ages, serum levels of leptin and INS were higher in the obese group than those in the control group, while the level of GH was lower in the obese group than that in the control group. Serum level of leptin was higher in the obese group of both boys and girls than that in the control group, with (0.71 +/- 0.17) nmol/L and (0.30 +/- 0.04) nmol/L and (1.11 +/- 0.21) nmol/L and (0.70 +/- 0.18) nmol/L, respectively. Ages at first spermatorrhea and menarche were much earlier in the obese children than those in the controls, with (12.5 +/- 1.2) and (13.2 +/- 1.2) years of age in boys and (11.6 +/- 0.8) and (12.8 +/- 0.9) in the girls, respectively. Blood levels of leptin was higher in the girls than that in the boys. Age at menarche and earlier in the girls than that of first spermatorrhea in the boys. Blood level of testosterone correlated inversely with that of leptin in boys, while that of estradiol correlated with that of leptin in girls. Level of GH correlated inversely with that of leptin in boys and correlated with that in girls. Level of INS correlated with that of leptin in the control girls. CONCLUSIONS: Leptin might have an effect on initiation of puberty in children, possibly with more importance in girls than in boys. The gender difference in the degree of correlations between levels of leptin and GH may cause their difference in the ages at sudden growth in boys and girls. The gender difference in the degree of correlation between levels of leptin and sex hormone may cause their difference in the ages at first spermatorrhea and menarche in both boys and girls.

Adolescent↗

PubMed2001

[A diagnosis test of stress fracture during basic training set of new military recruits].

OBJECTIVE: To evaluate efficacy of stress fracture (SF) during basic training for military recruits using clinical diagnosis method. METHODS: Two hundred and eighty-eight suspected SF were checked clinically and with bone scanning as golden standard. RESULTS: Sensitivity, specificity, accuracy, positive and negative predictive value, positive and negative likelihood ratios and Youden's index of clinical diagnosis were found to be 97.5%, 61.7%, 91.7%, 92.9%, 82.9%, 2.55, 0.04 and 0.59 respectively when calculated with cases. The agreement rate between two physicians was 81.7% with kappa value 0.64. When calculated with position, the precious measures were 97.2%, 84.1%, 89.7%, 82.0%, 97.6%, 6.12, 0.03, and 0.81 respectively. The agreement rate between two physicians was 94.4% with kappa value 0.88. CONCLUSION: Efficacy reliability and agreement of clinical diagnosis for SF seemed to be satisfactory.

Diagnostic Tests, Routine↗

PubMed2001

[Investigation on the mechanism of discogenic groin pain].

OBJECTIVE: To investigate the mechanism of discogenic groin pain. METHODS: Twenty-one adult wistar rats were divided into experimental group (paravertebral sympathetic trunks were reserved), control group (paravertebral sympathetic trunks were resected) and self-control group (right paravertebral sympathetic trunks were resected, the left ones were reserved) randomly. Each group has 7 rats. Horseradish peroxidase (HRP) were injected into the L5-L6 intervertebral discs from right postero-lateral side. Bilateral L1, L2 spinal ganglia were sectioned after 48 hours to observe the HRP labeled cells and the effect of resection of paravertebral sympathetic trunks. Another 7 adult wistar rats were used. The same steps of injection, removal and section as in experimental group were taken. Combining method of HRP retrograde tracer with immunocytochemistry stained the sections to determine the nature of HRP labeled cells. RESULTS: HRP labeled cells were found in bilateral L1, L2 spinal ganglia in each group. The comparison results of labeled cells numbers between groups (experimental group from 22.5 +/- 7.1 to 29.3 +/- 9.7, control group from 12.9 +/- 5.1 to 13.3 +/- 4.9, P < 0.01) and of self-control group (left 24.8 +/- 6.7, 30.6 +/- 8.4, right 15.8 +/- 4.4, 14.5 +/- 4.1, P < 0.01) show that the numbers of HRP labeled cells were significantly less than that after resection of paravertebral sympathetic trunks. HRP and SP double-labeled cells can be recognized in bilateral L1, L2 spinal ganglia in immunocytochemistry experiment. CONCLUSIONS: Discogenic groin pain is referred pain which is transmitted by sympathetic nerves and appears in the area that was segmentally innervated by anterior rami of L1 and L, spinal nerves.

Animals↗

PubMed2001

[Study of pefloxacin concentration in blood and sputum in the aged pneumonia patients with impairment of renal function].

OBJECTIVE: To study the drug concentration in blood and sputum, clinical effect and drug toxicity of pefloxacin in the aged pneumonia patients with different degree of impairment of renal function. METHODS: The patients were divided into four groups according to the impairment of renal functions pefloxacin 400 mg/12 h venous inflow, period of treatment is 10 days. Clinical manifestation and experimental index were registered; the drug concentration in blood and sputum was measured with biochemical technique, then compared and analyzed. RESULTS: The drug concentration in blood and sputum in four groups differed from the degree of the impairment of renal function. The concentration of drug in blood and sputum of the normal renal function was close to that in the low-grade impairment of renal function. Their clinical effective ratios were 83%, 80%, bacterium cleanup ratio was 86%. The difference of drug concentration in blood and sputum in the severe impairment of renal function was greater than that in the moderate renal function group, their clinical effective ratios were 66%, 53%, bacterial cleanup ratios were 57%, 36%, adverse reaction was growing along with degree of impairment of renal function. This drug has renal toxicity for moderate and severe impairment of renal function. CONCLUSION: In case of moderate impairment of renal function, prolongation of dose interval should be considered; pefloxacin should be avoided in severe impairment of renal function.

Aged↗

PubMed2001

[Therapeutic trial on function bandage for military training injuries].

OBJECTIVE: To evaluate therapeutic effectiveness of "Tianniansu" function bandage used for military training injuries (MTI). METHODS: In a randomized tri-blind controlled trial, recruits of all soft tissue injuries and stress fracture (SF) who took part in basic training in 1998 were separated into two groups--A and B with comparability, except the use of bandage. After close follow up on weekly base, part of the patents were subjected by ECT pre and post therapy. RESULTS: Effective rates of bandage A and B on treating soft tissue injuries were 66.7% and 86.4%, respectively. However, in terms of symptoms, detumescence effect of bandage B showed milder than that of A. The effective rate of bandage A and B in treating SF were 67.2% and 75.0%, respectively, but statistically not significant. The treatment effect in 26 injured tibias evaluated by bone scintigraphy pre and post treatment showed that the degree of osteogen injury after treatment was not significantly improved. CONCLUSION: "Tianniansu" function bandage had significant effect on treating soft tissue injuries, but did not have effect in treating SF.

Adult↗

PubMed2001

Osteomyelitis in the diabetic patient: diagnosis and treatment. Part 1: Overview, diagnosis, and microbiology.

Foot ulcerations are common among people with diabetes and often lead to mixed infections that require hospitalization and create significant challenges for clinicians. Many result in contiguous bone infections. Regimens used to treat osteomyelitis often are seen as controversial. A subtle balance between medical and surgical therapy is necessary if a potentially curative outcome is to be achieved. The following article is one of a two-part series. This, the first manuscript, discusses the diagnosis and microbiology of contiguous osteomyelitis in the diabetic foot.

Diabetic Foot↗

PubMed2001

Osteomyelitis in the diabetic patient: diagnosis and treatment. Part 2: Medical, surgical, and alternative treatments.

In the diabetic population, wound and foot infections are often mixed, containing from three to six organisms. This creates a significant problem regarding antibiotic protocols. Many of these episodes result in contiguous bone infections with subsequent erosive changes, sequestra, and involucrum. A multidisciplinary approach to treatment is often required. Studies have shown that a protocol of 6 weeks of intravenous antibiotics may be appropriate to treat osteomyelitis; however, this is controversial and often not curative. Osteomyelitis is a surgical disease; a subtle balance between medical and surgical therapy is necessary if a potentially curative outcome is to be achieved. The duration of antibiotic therapy may be shortened considerably after surgical intervention. In cases of infection mitigated by severe peripheral vascular disease, end-stage renal disease, diabetes, or other medical problems where surgery is not an option, long-term antibiotics may be used as suppressive therapy along with adjunctive local treatments. The following is the second article of a two-part series. The first paper discussed the diagnosis and microbiology of contiguous osteomyelitis in the diabetic foot. This article outlines the various medical, antibiotic, and surgical options available to the clinician. Adjunctive and alternative therapies also are discussed.

Amputation, Surgical↗

PubMed2001

[Long-term efficacy of vaccination against hepatitis B in newborns: 13 years' follow-up].

OBJECTIVE: To evaluate long-term efficacy of hepatitis B vaccination in newborns. METHODS: In the past 13 years we followed up the children who had been immunized with hepatitis B vaccine at birth in 1986 every other year. At each follow-up visit, every child was tested for HBsAg, anti-HBs and anti-HBc. RESULTS: HBsAg positive rate of these birth cohort was low (range between 0.46% and 0.98%) during 13 years' follow-up. Long-term efficacy of the vaccination in preventing HBsAg carriage was confirmed. CONCLUSIONS: Thirteen years later no booster was after needed.

Female↗

PubMed2001

[Determination of 35 polycyclic aromatic hydrocarbons in airborne suspended particulate by GC/MS].

OBJECTIVE: To establish capillary column GC/MS method for the determination of 35 polycyclic aromatic hydrocarbons (PAHs) in airborne suspended particulate. METHODS: The air samples collected by an electrostatic particle collector were Soxhlet-extracted using 3:1 benzene/ethanol, and then subjected to the procedures of concentration and clean-up. Finally, the target PAHs were determined by the proposed method. RESULTS: All the target PAHs could be well separated except for benzo[b] fluoranthene, benzo[j] fluoranthene and benzo [k] fluoranthene through temperature programming. The relative standard deviations of the method were 1.8%-17.7% and the recoveries ranged from 93.4% to 101.9%. The absolute detection limit ranged from 0.0001 ng to 0.1 ng. CONCLUSION: The method is applicable to the determination of more than 30 PAHs in the airborne suspended particulate samples.

Air Pollutants↗

PubMed2001

[Changes and relations of leptin, growth hormone and insulin during puberty in obese and non-obese children].

In order to study the regularity of changing leptin, growth hormone (GH) and insulin (INS) during puberty and their relationships, a group of 300 obese and 300 non-obese children, aged 10-15 were selected. Leptin level increased with age and then decreased in boys, but it had only increasing tendency in girls. The GH level increased and then decreased suddenly in all groups. There was no obvious regularity in the change of INS. Serum leptin and INS levels were higher (P < 0.01) in obese children than that in non-obese children, while GH levels were significantly lower (P < 0.01) in obese boys. Results also showed that GH was negatively correlated with leptin in boys (obese group: r = -0.74, P < 0.05; non-obese group: r = -0.69, P < 0.05) and positively correlated with leptin in girls (obese group: r = 0.58, P < 0.05; non-obese group: r = 0.67, P < 0.01). There was a positive correlation between INS and leptin in non-obese girls (r = 0.54, P < 0.05). It is concluded that leptin might play an important role during the initial stage of puberty in children and the effect of leptin on pubescent development in girls is greater compared with boys. The correlation between leptin and GH are gender dependent in boys and girls, which may cause the timing differences of sudden growth in boys and girls.

Adolescent↗

PubMed2001

[Effects of chromium and fish oil on insulin resistance and leptin resistance in obese developing rats].

In order to study the effects of chromium and fish oil on insulin resistance and leptin resistance in obese rats, 50 rats were divided randomly into five groups: basal diet group was fed on normal diet, other four groups were fed on high fat diet. In addition to high fat diet, chromium group fed chromium (3 mg/kg BW), fish oil group fish oil(5 ml/kg BW) and chromium + fish oil group fed chromium(3 mg/kg BW) plus fish oil(5 ml/kg BW). Blood samples were collected in the following five weeks from tail each week to determine blood sugar, insulin and leptin. The results showed that blood sugar, insulin and leptin in fish oil group and chromium group were lower than those in high fat diet control group. Chromium and fish oil improved the insulin resistance and leptin resistance.

Animals↗

PubMed2001

[Inhibition effect of soybean isoflavones on the oxidative modification of low-density lipoprotein].

In order to investigate the effect of soybean isoflavones(SI) on the oxidative modification to low-density lipoprotein(LDL) and to differentiate the effect of SI and alpha-tocopherol, in vitro and in vivo test were conducted. An in vitro model of LDL oxidative modification induced by copper-ion was established by monitoring the production of thiobarbituric acid-reactive substances (TBARS) and conjugated dienes after SI or alpha-tocopherol was added. The in vivo test was conducted by feeding rats with a high fat diet supplemented with SI and measured the sensitivity of LDL oxidative modification mediated by Cu2+ in vitro. The results revealed that when SI was added into the in vitro LDL oxidation system, the content of TBARS or conjugated dienes in the system was much reduced with a dose-effect relationship, whether lipid oxidation being initiated or not by copper-ion at 37 degrees C. In comparison with SI, only a significant inhibiting effect on lipid oxidation while alpha-tocopherol was added before the initiation of oxidation. High fat diet induced a rising of LDL sensitivity of oxidative stress, and adding SI to the high fat diet could counteract the sensitivity of LDL oxidative modification significantly. It is concluded that SI is a valuable natural antioxidant different from alpha-tocopherol in inhibiting LDL oxidative modification both in vitro and inv vivo.

Animals↗

PubMed2001

[Systemic breeding of the new variety of Biantiao ginseng (Panax ginseng)].

OBJECTIVE: To breed new varieties of Biantiao ginseng for high yield and fine quality. METHODS: Systemic breeding methods were applied. About 3,000 outstanding Biantiao ginseng roots were selected and planted in breeding field, and self-crossed for four generations. During the course, inferior lines or plants were rejected. Then strain comparison, identification of resistance to black-speck disease, and analysis of active compositions were carried out. RESULTS: "Biantiao 1" (BT1), the first new variety of Biantiao ginseng, with green stems and thick, long, elegant roots and median resistance to black-speck disease, has been harvested since 20 years. The percentage of Biantiao ginseng roots and yield were 15% and 30% higher than the control's respectively. The content of total ginsenosides and the main monomers was 1.8%-2.5% higher than the control's. The characteristics of overground part and root of BT1 were uniform and stable. CONCLUSIONS: BT1, a new excellent ginseng variety, has a good potential value to be generalized in ginseng production.

Breeding↗

PubMed2000

NMR structure and mutagenesis of the third Bir domain of the inhibitor of apoptosis protein XIAP.

The inhibitor of apoptosis proteins (IAPs) regulate the caspase family of cysteine proteases, which play an important role in the execution of programmed cell death. Human X-linked inhibitor of apoptosis protein (XIAP) is a potent inhibitor of caspases-3, -7, and -9. Here we show that the Bir3 domain is the minimal region of XIAP that is needed for potent caspase-9 inhibition. The three-dimensional structure of the Bir3 domain of XIAP, determined by NMR spectroscopy, resembles a classical zinc finger and consists of five alpha-helices, a three-stranded beta-sheet, and a zinc atom chelated to three cysteines and one histidine. The structure of the Bir3 domain is similar to that of the Bir2 domain of XIAP but differs from the previously determined structure of the Bir3 domain of MIHB. Based on site-directed mutagenesis, we have identified the regions of the Bir3 domain of XIAP that are important for inhibiting caspase-9. Despite the structural similarities of the Bir2 and Bir3 domain of XIAP, a different set of residues were found to be critical for inhibiting the individual caspases. These results suggest that XIAP inhibits caspase-3 and caspase-9 in a different manner.

Amino Acid Sequence↗

PubMed2000

The impact of school-organized sport activities on the priority youth health-risk behaviors.

PURPOSE: To evaluate the impact of school-organized sport activities on the priority youth health-risk behaviors.METHODS: Data were taken from The 1997 National School-based Youth Risk Behavior Survey. Measures of prevalence rates in six categories of priority health-risk behaviors defined by Centers for Disease Control and Prevention were performed between participants and non-participants in school-organized sport activities. Then multiple logistic regression analyses were used to assess the association between participation in school-organized sport activities and the priority health-risk behaviors.RESULTS: Overall, 49.5% of students nationwide participated in school-organized sport activities in 1997. The major behavioral factors that proved statistically significant in predicting participation in school-organized activities in the logistic regression model were non-use of seatbelt, non-use of helmet, and use of chewing tobacco. Behavioral factors that were inversely related to participation in school-organized activities were smoking cigarettes, using different kinds of drugs, using condoms, carrying weapons, eating vegetables, and attempting suicide.CONCLUSIONS: Based on the nationally representative data, participation in school-organized sport activities was positively associated with many desirable health behaviors. However, a challenge for us will be not only to promote youth participation in school-organized sport activities, but also to address some co-existing behavioral problems that may lead to non-intentional injury and use of chewing tobacco.

Journal Article↗

PubMed2000

Deletion of azoospermia factor a (AZFa) region of human Y chromosome caused by recombination between HERV15 proviruses.

Deletion of any of three regions of the human Y chromosome results in spermatogenic failure and infertility. We previously sequenced one of these regions, azoospermia factor a (AZFa) and found that it spanned approximately 800 kb. By sequence-tagged site (STS) content mapping, we roughly defined deletion breakpoints in two unrelated, azoospermic men with AZFa deletions. The positions of proximal and distal breakpoints were similar in the two men. Hypothesizing that the deletions might have been generated by homologous recombination, we searched electronically for DNA sequence similarities between the proximal and distal breakpoint regions. These comparisons revealed the most striking sequence similarities anywhere along or near the AZFa region. In the proximal breakpoint region, we identified a 10 kb provirus of the recently defined HERV15 class of endogenous retroviruses. In the distal breakpoint region, we found a second HERV15 provirus, 94% identical in DNA sequence to the first and in the same orientation. (A partial LINE insertion in this distal provirus proved to be the basis of the previously described DYS11/p12f polymorphism.) The AZFa deletions in the two men differed slightly, but all breakpoints fell within the HERV15 proviruses. Indeed, sequencing of deletion junctions from the two men revealed that homologous recombination had occurred within large domains of absolute sequence identity between the proximal and distal proviruses. When combined with published STS mapping data for other AZFa-deleted men, our findings suggest that recombination between these two HERV15 proviruses could account for most AZFa deletions.

Base Sequence↗