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Y Jiang

Publications and source records attributed to Y Jiang.

At least 235 records · Page 13Linked to original sources
PubMed2000

Cryptorchidism induces mouse testicular germ cell apoptosis and changes in bcl-2 and bax protein expression.

Up to half of the germ cells die during their development. The mechanism involved in their death is still unclear. We investigated the possibility that the testicular germ cell loss may be due to a change in the testicular temperature and apoptosis through the interplay of bcl-2 and bax proteins. To investigate the effect of temperature on apoptosis and the role of bcl-2 and bax proteins in apoptosis in adult mouse testis, we used the experimental unilateral cryptorchidism model. We found that the weight of the affected testis decreases in 6 to 15 days after operation (p < 0.05). H&E staining showed vacuolization of the seminiferous epithelium and the appearance of multinucleated giant cells with loss of germ cells. The terminal deoxynucleotidyl transferase-mediated dUTP nick-end-labeling method (TUNEL) showed positive staining germ cells scattered in normal testicles that increased significantly 6 to 15 days after experimental cryptorchidism (p < 0.05). Positive cells were mainly primary spermatocytes and round spermatids. DNA ladder was seen in 1.5% agarose gel electrophoresis in 6 to 15 days-operated testicles. Biotin-avidin DCS system indirect immunofluorescence technique indicated that the bcl-2 protein was chiefly distributed in the cytoplasm of germ cells in normal testicles, whereas the bax protein was chiefly expressed in the cytoplasm of germ cells in 6 to 15 days-operated testicles. Western blot analysis showed that the bcl-2 protein down-regulated and the bax protein up-regulated apoptosis. Our data indicated that cryptorchidism-induced testicular cell degeneration was mediated by apoptosis probably as the result of increased temperature in the testicle; bcl-2 and bax proteins played important roles in male germ cell apoptosis.

Animals↗
PubMed2000

[Investigation on the stimulation effect of polypyrrole film on rat hepatic cells].

Poypyrrole(PPy) films were prepared at 1 x 10(-3) mA/cm2 electropolymerization current density on indium-tin oxide(ITO)substrate. The PPy films were well-distributed, translucent, stable and insoluble. Moreover, they can be sterilized by steam disinfection. Rat hepatic cells were cultured on these films. The results show that PPy films have good biocompatibility and they can accelerate cell growth under electrical stimulation. The cells on PPy films reach the largest cell density earlier than the cells on tissue culture polystyrene(TCPS). Furthermore, rat hepatic cells can generate on PPy films. The cells on PPy films grow faster and enter logarithmic growth phase earlier than those on TCPS.

Animals↗
PubMed2000

Rapid initial removal of chylomicron remnants by the mouse liver does not require hepatically localized apolipoprotein E.

Apolipoprotein E (apoE) is a ligand for the low density lipoprotein receptor (LDLR) and the low density lipoprotein receptor-related protein (LRP). The aim of the present study was to clarify the role of hepatically localized apoE in the rapid initial removal of chylomicron remnants by using the isolated perfused liver. Radiolabeled chylomicron remnants were perfused in a single nonrecirculating pass into the livers of C57BL/6J (wild-type) mice, apoE-knockout mice, and apoE/LDLR-knockout mice for a period of 20 min. Aliquots of the perfusate leaving the liver were collected at regular intervals and the rate of removal of radioactivity was determined. At a trace concentration of chylomicron remnants (0.05 microgram of protein per ml), wild-type mouse livers removed at a steady state of 50-55% of total chylomicron remnants perfused per pass; livers from apoE-knockout mice had the same capacity as wild-type mouse livers. When the concentration of remnants was increased to 12 microgram of protein per ml, a level at which it has been shown that LDL receptor and LRP are near saturation, the capacity of the wild-type mouse livers to remove chylomicron remnants was decreased to 10-25% per pass, confirming that the removal mechanisms were nearing saturation. However, instead of finding a greater reduction in the removal rates or impairment in chylomicron remnant removal, livers from apoE-knockout mice were just as efficient as those from wild-type mice in removing remnants. Livers of mice that lacked both apoE and the LDLR also had a similar rate of removal at relatively low remnant concentrations (0.05-0.5 microgram/ml), but had reduced capacity in removing remnants at a relatively high concentration (4-12 microgram/ml) of chylomicron remnants ( approximately 20% per pass). The rate of removal at these concentrations, however, was similar to that attributed to the LRP in previous studies. Chylomicron remnants, whose apolipoproteins were disrupted by trypsinization, were removed at a normal rate by wild-type mouse livers but there was almost no removal by apoE-knockout mouse livers. At higher concentrations, however, the removal of apolipoprotein-disrupted chylomicron remnants was decreased. Our present findings do not support the hypothesis that hepatically localized apoE is a critical factor in the rapid initial removal of chylomicron remnants by either of the major pathways but do suggest that hepatically localized apoE can be added to lipoproteins to accelerate their uptake, although this process may have a limited capacity to compensate for apoE deficiency on lipoproteins.

Animals↗
PubMed2000

Menarche, sexual practices, and pregnancy: model testing.

Rates of adolescent pregnancy and childbearing, while in slight decline in the United States since 1992, remain high enough to warrant significant national concern. Birth rates, however, remain particularly high for minority adolescents. One hundred fifty-two records of African American and Latina adolescents receiving prenatal care from nurse midwives at an inner city university clinic were reviewed to partially test a developmental maturity model of pregnancy using logistic regression. The relationships between age at menarche to sexual practices and age at first pregnancy were examined. Mean age of the sample was 16.5 years, mean age at menarche was 12.2 years, at first coitus was 14.6 years, and at first pregnancy was 15.6 years. Thirty percent of the girls were experiencing second pregnancies. Birth control use by the adolescents was inconsistent, with only 20 percent using birth control at first coitus. Multiple regression analyses produced a model explaining 50 percent of the variance in age at first pregnancy. The predictor variables in the model were age at first coitus, age at menarche, race/ethnicity, and use of birth control at first coitus. Further analyses indicate that for childbearing adolescents, age at first coitus is a classic intervening variable between age at menarche and age at first pregnancy. Early physiologic maturers appear to lack the psychological and cognitive maturity required to cope with their emerging sexuality resulting in early unprotected coitus and pregnancy. Findings provide guidance to healthcare providers for the development of interventions to prevent unplanned pregnancies.

Adaptation, Psychological↗
PubMed2000

Brain expression of presenilins in sporadic and early-onset, familial Alzheimer's disease.

BACKGROUND: Mutations in the presenilin proteins cause early-onset, familial Alzheimer's disease (FAD). MATERIALS AND METHODS: We characterized the cellular localization and endoproteolysis of presenilin 2 (PS2) and presenilin 1 (PS1) in brains from 25 individuals with presenilin-mutations causing FAD, as well as neurologically normal individuals and individuals with sporadic Alzheimer's disease (AD). RESULTS: Amino-terminal antibodies to both presenilins predominantly decorated large neurons. Regional differences between the broad distributions of the two presenilins were greatest in the cerebellum, where most Purkinje cells showed high levels of only PS2 immunoreactivity. PS2 endoproteolysis in brain yielded multiple amino-terminal fragments similar in size to the PS1 amino-terminal fragments detected in brain. In addition, two different PS2 amino-terminal antibodies also detected a prominent 42 kDa band that may represent a novel PS2 form in human brain. Similar to PS1 findings, neither amino-terminal nor antiloop PS2 antibodies revealed substantial full-length PS2 in brain. Immunocytochemical examination of brains from individuals with the N141I PS2 mutation or eight different PS1 mutations, spanning the molecule from the second transmembrane domain to the large cytoplasmic loop domain, revealed immunodecoration of no senile plaques and only neurofibrillary tangles in the M139I PS1 mutation stained with PS1 antibodies. CONCLUSIONS: Overall presenilin expression and the relative abundance of full-length and amino-terminal fragments in presenilin FAD cases were similar to control cases and sporadic AD cases. Thus, accumulation of full-length protein or other gross mismetabolism of neither PS2 nor PS1 is a consequence of the FAD mutations examined.

Age of Onset↗
PubMed2000

Chronic cigarette smoking induces an oxidantantioxidant imbalance in the testis.

OBJECTIVES: We have previously demonstrated the harmful effect of chronic inhalation of cigarette smoke on the testis in Sprague-Dawley rats. The aim of the present study was to investigate the role of free oxygen radicals and reactive oxygen species in inducing testicular damage in Sprague-Dawley rats following exposure to cigarette smoke. MATERIALS AND METHODS: Sprague-Dawley rats, 25 days old, were exposed daily to cigarette smoke by the Walton smoking machine for a period of 15, 30, and 45 days. Age-matched Sprague-Dawley rats were exposed to room air with the smoking machine and served as controls. Rats were sacrificed from each group at 15, 30, and 45 days and the testes were removed. The testicular tissue levels of glutathione and lipid peroxidation product malonaldehyde (MDA) were measured colorimetrically using the Bioxytech GSH-400 and LPO-586 kits, respectively. The activity of glutathione peroxidase was assessed colorimetrically using the Bioxytech GPx-340 kit. Statistical analysis was performed using ANOVA followed by the t test. RESULTS: There was a 47.8% increase in the MDA in the treated rat testis compared with the control rat after 45 days of exposure to cigarette smoke or air, respectively (p < 0.05). This was associated with a parallel significant decrease in the level of glutathione and glutathione peroxidase activity in the treated rat testis, 38.2% and 29.1%, respectively, after 45 days of cigarette smoke exposure (p < 0.05). No significant difference was noted in the levels of glutathione, glutathione peroxidase, and lipid peroxidation end products after 15 and 30 days of treatment. CONCLUSIONS: Chronic cigarette smoke inhalation is associated with an increase in the level of oxidants and a simultaneous decrease in the level of antioxidants in the rat testis. This abnormality of the oxidant-antioxidant balance may be one of the mechanisms leading to testicular tissue damage and abnormal spermatogenesis in the rat testis following chronic inhalation of cigarette smoke.

Animals↗
PubMed2000

[Mechanism of Se-Indocalamus tessdatus polycassine(S-ITPS) against human immunodeficiency virus type 1 (HIV-1)].

OBJECTIVE: To study the mechanism of Se- Indochalamus tessdatus polycassine (S-ITPS) against HIV-1 and to provide a theoretical support for developing the anti-HIV drugs. METHODS: S-ITPS was added to MT4 cells before viral inoculation, at the same time of viral inoculation, then the cells were cultured with or without S-ITPS for 1-4 weeks, finally, cytopathic effect (CPE), MTT staining method for viable cells(MTT assay),p24 antigen titer (ELISA), or infectivity (TCID50 assay) of the cultural supernatants were used as markers to monitor the virus growth. RESULTS: S-ITPS can inhibit HIV-induced CPE (1C50 = l0microg/ml)and viral replication (1C50 = 156 microg/ml)in dose dependent manner. The virus infectivity in the presence of S-ITPS was greatly decreased than that of the control. The virus inhibition was enhanced under the presence of noncytotoxic drug concentration of <1250 microg/ml in cell culture, inhibition of viral replication by S-ITPS was 73.7%, 63.5%, 87.7% and 95.4% at week 1, week 2, week 3 and week 4 of cultured cells respectively. It can also inhibit absorption of HIV-1 to MT-4 cells, but no inhibition of HIV-1 was seen when MT-4 cells were pretreated with S-ITPS. Virus can be inactivated by the agent also. CONCLUSIONS: S-ITPS is a potent anti-HIV- 1 agent in MT-4 /HIV- 1 cultural system, at least two mechanisms were included inhibition both of HIV-1 absorption to MT-4 cells and viral replication in HIV-infected cells. S-ITPS inhibition of CPE is stronger than that of p24 antigen production.

Anti-HIV Agents↗
PubMed2000

Fast repairing of oxidized OH radical adducts of dAMP and dGMP by phenylpropanoid glycosides from Scrophularia ningpoensis Hemsl.

AIM: To investigate the antioxidative activity of the constituents of the roots of Scrophularia ningpoensis (Chinese name: Xuanshen). METHODS: The main compounds from the roots of Scrophularia ningpoensis were isolated and identified by chromatography and FABMS, NMR etc. Using the techniques of pulse radiolysis, the electron transfers from iridoid glycosides (IG) or phenylpropanoid glycosides (PG) to oxidized OH radical adducts of 2'-deoxyadenosine-5'-monophosphate acid (dAMP) or 2'-deoxyguanosine-5'-monophosphate acid (dGMP) were observed. RESULTS: Two IG: harpagoside and harpagide, two PG: angoroside C and acteoside were obtained as the main hydrophilic constituents of the plant. At 0.1 mmol/L concentration, angoroside C and acteoside were able to repair the oxidized OH adducts dAMP and dGMP significantly. However, harpagoside and harpagide had no such effect. The electron transfer rate constants of angoroside C with dAMP and dGMP were 4.2 x 10(8) and 10.3 x 10(8) L.mol-1.s-1; the electron transfer rate constants of acteoside with dAMP and dGMP were 5.3 x 10(8) and 20.2 x 10(8) L.mol-1.s-1. CONCLUSION: PG from Scrophularia ningpoensis have a potent antioxidative activity for reducing of the oxidized OH adducts of dAMP and dGMP.

Antioxidants↗
PubMed2000

Role of p38 protein kinase in heat-induced Raw cells apoptosis.

OBJECTIVE: To elucidate the role of p38 in heat-induced apoptosis in the monocytic cell line Raw264.7. METHODS: Apoptosis was detected using flow cytometric analysis, DNA electrophoresis, Westero blot and a protein kinase assay. RESULTS: A marked increased in p38 activity was detected 15 min after heating and reached maximal activity 30 min post stimulation, then returned to the pre-stimulated level 2 h later. The percentage of apoptotic cells was obviously increased 3 h after heating. Stimulation of p38 preceded the induction of apoptosis, and the p38 specific inhibitor, FHPI, can inhibit thermal injury induced cell apoptosis. CONCLUSIONS: p38 activation is required for heat-induced apoptosis in Raw264.7 cells, and stimulation of the p38 signaling pathway contributes to cell death.

Animals↗
PubMed2000

Identification of a mutation hotspot in exon 8 of Wilson disease gene by cycle sequencing.

OBJECTIVE: To screen for mutation hotspot of Wilson disease (WD) gene in Chinese population. METHODS: Cycle sequencing was used to detect mutation in exon 8 of WD gene in 30 patients with Wilson disease. RESULTS: The same missense mutation, Arg779Leu, was identified in 14 WD patients, four of whom were homozygous and the other heterozygous for this mutation. The frequency of this mutation in Chinese patients was 30%. CONCLUSION: The codon 779 (CCG-->CTG) of exon 8 of WD gene was one of mutation hotspots in Chinese.

Adenosine Triphosphatases↗
PubMed2000

[An experimental study of tooth mesial migration].

OBJECTIVE: To study the mechanism of tooth mesial migration with animal experiment. METHODS: The upper and lower first molars of Wuzhishan miniature pigs were used as experimental teeth. The mesial migration of experimental teeth was calculated and analysed by measuring the models. Fluorescent mark was used and analysed by injecting tetracycline and xvlenol orange, and histological changes were analyzed. RESULTS: The lower teeth migrate mesially 0.14 mm and 1.21 mm during 16 weeks, and the upper teeth migrate mesially 1.36 mm and 2.08 mm during 24 weeks. The distal alveolar bones of experimental teeth had fluorescent bands; alveolar bones of teeth without antagonist teeth reconstructed in vertical direction; the distance between fluorescent bands of lower experimental teeth without antagonist teeth was wider than that of teeth with antagonist teeth. The fluorescent bands formed in both mesial and distal cementum. CONCLUSION: The results don't support the point that transseptal fibre or force of molar eruption makes teeth migrate mesially; the mesial migration of teeth is related with the reconstruction of alveolar bones and the stress distribution in the bones.

Animals↗
PubMed2000

[Perioperative changes of plasma ET-1 in patients undergoing coronary artery bypass grafting and the effect of nitroglycerin].

OBJECTIVE: To observe the dynamic changes of the plasma ET-1 and the effect of low dose nitroglycerin in patients with coronary artery bypass surgery. METHODS: 40 patients with coronary artery bypass surgery were divided into group A and B. Group B received intravenous nitroglycerin 1 microg x kg(-1) x min(-1) perioperatively. We used RIA to assay the plasma ET-1 level. All the hemodynamic parameters were recorded by the Swan-Ganz catheter. RESULTS: The preoperative plasma ET-1 level in patients with coronary artery disease was significantly higher than the normal level. Five minutes after cardiopulmonary bypass in these patients the plasma ET-1 level was increased significantly until 6 to 8 hours after operation. The increased plasma ET-1 level in group B was less than in group A. There was a positive correlation between the plasma ET-1 level and the mean pulmonary pressure in group A 2 and 8 hours after operation. CONCLUSION: In patients undergoing coronary artery bypass surgery, the increased plasma ET-1 level may be partly due to the influence of cardiopulmonary bypass. Low dose of nitroglycerin is beneficial to these patients.

Coronary Artery Bypass↗
PubMed2000

[Detection of K-ras gene mutations in DNA extracted from the plasma of patients with pancreatic cancer].

OBJECTIVES: To detect mutations of the K-ras codon 12 in DNA extracted from the plasma of patients with pancreatic cancer, and to explore the possibility of using this method in early diagnosis of pancreatic cancer. METHODS: Plasma DNA was isolated from the blood of 22 patients with pancreatic cancer and from 20 normal controls. K-ras codon 12 mutations were detected by mutant enriched polymerase chain reaction-restriction fragment length polymorphism technique and subsequent product sequencing. The relation of K-ras mutations in plasma to clinical features in pancreatic cancer patients was analyzed. RESULTS: Seventeen (77.3%) of 22 patients with pancreatic cancer had a codon 12 K-ras mutation in their plasma DNA. In two patients, the PCR products were sequenced and the mutations were confirmed. The occurrence of K-ras mutations in the plasma DNA was not related to tumor location, tumor size, and TNM stage. No K-ras mutation was detected in the plasma specimen of any of the normal controls. CONCLUSIONS: K-ras mutations are frequently found in the plasma DNA of patients with pancreatic cancer. Analysis of K-ras mutation in the plasma DNA may be useful in the early detection of pancreatic cancer.

Adult↗
PubMed2000

[Diagnosis and treatment of primary retroperitoneal teratoma].

OBJECTIVE: To study the diagnosis and treatment of primary retroperitoneal teratoma in adults. METHODS: The clinical data of 36 adult patients with primary retroperitoneal teratoma were reviewed. RESULTS: Nine patients were male and 27 female. Twenty-four patients (66.7%) aged (30.4 +/- 8.0) years were benign, and 12 patients (36.3%) aged (39.6 +/- 10.5) years were malignant. Four (21.1%) cases of presacral tumors and 8 (47.1%) of 17 cases of epigastric tumors were malignant. Clinical features included abdominal or presacral masses and compression symptoms with or without tumor markers. All patients, except one with liver metastasis, underwent radical resection. Patients without malignant metastasis survived, but 5 patients with malignant metastasis survived more than 2 years after operation. CONCLUSIONS: Malignant metastasis of retroperitoneal teratoma is closely related to the age of adults. Early radical resection is the optimal treatment. Adjuvant chemotherapy can induce a short-time remission in those with germ cell elements.

Adolescent↗
PubMed2000

[The affect of Erigeron Breviscapus (Vant.) Hand-Mazz on axoplasmic transport of optic nerve in rats with experimentally elevated intraocular pressure].

OBJECTIVE: To investigate whether Erigeron Breviscapus (Vant.) Hand-Mazz (EBHM) can improve the optic nerve axoplasmic transport in rats with experimentally elevated intraocular pressure (IOP). METHODS: Thirty healthy SD rats were used for the study, acute elevated IOP model in the right eye was built, then they were divided into three groups randomly: Group A (0 day group) included six rats for retinal ganglion cell (RGC) counting via left superior colliculus retrograde horse radish perokidase labeling; Group B, twelve rats divided into EBHM treatment group and control group (6 rats in each subgroup) for RGC counting via left superior colliculus retrograde labeling after twenty days, and Group C included twelve rats submitted the same treatment and procedure as group B after 40 days. RESULTS: After 0 day of acute elevated IOP, no labeled RGCs were observed. After twenty days of acute elevated IOP, in the control and EBHM subgroups the density of labeled RGCs were (423 +/- 220)/mm(2) and (749 +/- 294)/mm(2) respectively, the difference between two subgroups showed statistical significance (P < 0.01). After 40 days of acute elevated IOP, the density of RGCs in the control and EBHM subgroups in group C were (610 +/- 315)/mm(2) and (1,048 +/- 393)/mm(2) respectively, the difference between the two subgroups being statistically significant (P < 0.01). CONCLUSION: After 20 days and 40 days of acute elevation of IOP, the density of RGCs is obviously higher in EBHM group than that in the control group. It is revealed that EBHM can improve the optic nerve axoplasmic transportation blocked by acute elevation of IOP in rats.

Animals↗
PubMed2000

[Glutamate in experimental acute elevated intraocular pressure models of rabbits].

OBJECTIVE: To measure the concentration of glutamate (Glu) in the retina of eyes with experimentally elevated intraocular pressure (IOP). METHODS: High-performance liquid chromatography (HPLC) was utilized to measure the Glu in the retina. 18 rabbits were divided into three groups, each group including 6 rabbits. In one eye of each rabbit in group 1, the IOP was elevated to 60 mm Hg (1 mm Hg = 0.133 kPa) by the anterior chamber perfusion with normal saline maintained for 4 hours, while the IOP of the other eye was maintained at 20 mm Hg by the same method. In group 2, the same experimental method was carried out, but the elevated IOP was maintained at 30 mm Hg. Group 3 was a normal control group without perfusion. RESULTS: High-IOP eyes (60 mm Hg and 30 mm Hg) had high glutamate concentration in the retinal tissue than that in low-IOP eyes (20 mm Hg) (P < 0.05). CONCLUSION: Elevated IOP induces higher content of glutamate in the retina.

Animals↗
PubMed2000

[Clinical study on treatment of nasopharyngeal carcinoma by radio- and chemotherapy with supplementary moxibustion on Shenque point].

OBJECTIVE: To evaluate the effect of supplementary moxibustion in treating III, IV a stage nasopharyngeal carcinoma (NPC) with radio- and chemotherapy. METHODS: Fifty-six cases of NPC were randomly divided into two groups, 28 in each group. They were treated with radiotherapy in routine or chemotherapy adopting AD protocol. Salt-separated moxibustion on Shenque (Ren 8) point was given to the treated group from beginning of radio- and chemotherapy for 30 times as one therapeutic course. RESULTS: The remission rate in the two groups after radio- and chemotherapy was not different significantly. The toxic and side-effect occurrence was less in the treated group than that in the control group (P < 0.05). The 5-year local control rates of NPC and cervical lymphnode were 85.7% and 85.0% in the treated group, which were higher than those in the control group (78.6% and 78.9%). The 5-year survival rate in the two groups were 50.0% and 35.7% respectively. After radio- and chemotherapy, the blood content of malonyldialdehyde (MDA), middle molecular substance and sulfhydryl reduced the SOD activity ascended in the treated group, the difference was significant as compared with those in the control group (P < 0.05, P < 0.01). CONCLUSION: The supplementary moxibustion on Shenque point could obviously reduce the toxic side-effect of advanced NPC patients treated with radio- and chemotherapy.

Acupuncture Points↗