Maize nac1 and cld genes map to chromosome arms 10L and 2S, and to 4L and 5L, respectively.
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Genes, Plant↗
Biomedical subjects
Y Ding
Publications and source records attributed to Y Ding.
Effects of simulated hyperglycemia, insulin, and glucagon on endothelial nitric oxide synthase expression.
Diabetes is associated with endothelial dysfunction and increased risk of hypertension, cardiovascular disease, and renal complications. Earlier studies have revealed that hyperglycemia impairs nitric oxide (NO) production and diabetes causes endothelial dysfunction in humans and experimental animals. This study was designed to test the effects of altered concentrations of glucose, insulin, and glucagon, the principal variables in types I and II diabetes, on NO production and endothelial NO synthase (eNOS) expression in cultured human coronary endothelial cells. Cultured endothelial cells were incubated in the presence of glucose at either normal (5.6 mM) or high (25 mM) concentrations for 7 days. The rates of basal and bradykinin-stimulated NO production (nitrate + nitrite) and eNOS protein expression (Western blot) were then determined at the basal condition and in the presence of insulin (10(-8) and 10(-7) M), glucagon (10(-8) and 10(-7) M), or both. Incubation with a high-glucose concentration for 7 days significantly downregulated, whereas insulin significantly upregulated, basal and bradykinin-stimulated NO production and eNOS expression in cultured endothelial cells. The stimulatory action of insulin was mitigated by high-glucose concentration and abolished by cotreatment of cells with glucagon. Thus hyperglycemia, insulinopenia, and hyperglucagonemia, which frequently coexist in diabetes, can work in concert to suppress NO production by human coronary artery endothelial cells.
Cells, Cultured↗
Vascular hyporesponsiveness in simulated microgravity: role of nitric oxide-dependent mechanisms.
Simulated microgravity depresses the ability of arteries to constrict to norepinephrine (NE). In the present study the role of nitric oxide-dependent mechanisms on the vascular hyporesponsiveness to NE was investigated in peripheral arteries of the rat after 20 days of hindlimb unweighting (HU). Blood vessels from control rats and rats subjected to HU (HU rats) were cut into 3-mm rings and mounted in tissue baths for the measurement of isometric contraction. Mechanical removal of the endothelium from carotid artery rings, but not from aorta or femoral artery rings, of HU rats restored the contractile response to NE toward control. A 10-fold increase in sensitivity to ACh was observed in phenylephrine-precontracted carotid artery rings from HU rats. In the presence of the nitric oxide synthase (NOS) substrate L-arginine, the inducible NOS inhibitor aminoguanidine (AG) restored the contractile responses to NE to control levels in the femoral, but not carotid, artery rings from HU rats. In vivo blood pressure measurements revealed that the peak blood pressure increase to NE was significantly greater in the control than in the HU rats, but that to AG was less than one-half in control compared with HU rats. These results indicate that the endothelial vasodilator mechanisms may be upregulated in the carotid artery, whereas the inducible NOS expression/activity may be increased in the femoral artery from HU rats. These HU-mediated changes could produce a sustained elevation of vascular nitric oxide levels that, in turn, could contribute to the vascular hyporesponsiveness to NE.
Acetylcholine↗
Upregulation of NOS by simulated microgravity, potential cause of orthostatic intolerance.
Prolonged exposure to microgravity during spaceflight or extended bed rest results in cardiovascular deconditioning, marked by orthostatic intolerance and hyporesponsiveness to vasopressors. Earlier studies primarily explored fluid and electrolyte balance and baroreceptor and vasopressor systems in search of a possible mechanism. Given the potent vasodilatory and natriuretic actions of nitric oxide (NO), we hypothesized that cardiovascular adaptation to microgravity may involve upregulation of the NO system. Male Wistar rats were randomly assigned to a control group or a group subjected to simulated microgravity by hindlimb unloading (HU) for 20 days. Tissues were harvested after death for determination of total nitrate and nitrite (NOx) as well as endothelial (e), inducible (i), and neuronal (n) NO synthase (NOS) proteins by Western blot. Separate subgroups were used to test blood pressure response to norepinephrine and the iNOS inhibitor aminoguanidine. Compared with controls, the HU group showed a significant increase in tissue NOx content and an upregulation of iNOS protein abundance in thoracic aorta, heart, and kidney and of nNOS protein expression in the brain and kidney but no discernible change in eNOS expression. This was associated with marked attenuation of hypertensive response to norepinephrine and a significant increase in hypertensive response to aminoguanidine, suggesting enhanced iNOS-derived NO generation in the HU group. Upregulation of these NOS isotypes can contribute to cardiovascular adaptation to microgravity by promoting vasodilatory tone and natriuresis and depressing central sympathetic outflow. If true in humans, short-term administration of an iNOS inhibitor may ameliorate orthostatic intolerance in returning astronauts and patients after extended bed rest.
Animals↗
Relation between left ventricular geometric alteration and extracardiac target organ damage in hypertensive patients.
To study the relation between left ventricular geometric alteration and extracardiac target organ damage in hypertensive patients. A retrospective study of 298 patients with essential hypertension was performed. Left ventricular mass index (LVMI) and relative wall thickness (RWT) were calculated using echocardiographic data. Patients were divided into four groups based on their left ventricular geometric pattern as determined using LVMI and RWT. Each of the four left ventricular geometric patterns was associated with a different degree of extracardiac organ damage. In multivariate analysis, LVMI and RWT showed strong, significant correlation to retinal changes and increases in serum creatinine levels, respectively. Alteration of left ventricular geometry resulted in an increase in the degree of extracardiac target organ damage. Echocardiographic classification of left ventricular geometry can further stratify hypertensive patients according to risk, and possibly according to the indications for intensive treatment.
Aged↗
Effect of protein denaturation on void fraction in foam separation column.
Foam fractionation is a cost-effective process that uses air to extract protein from a liquid (in this case "crude" dilute egg-albumin solution). This article deals with how the void fraction (fraction of air in the aerated solution) of foam is affected by heat denaturation of the protein. A 2-mm glass tube was used to sample the foam-liquid interface fluid in a 35-mm-diameter column in order to detect small changes in void fraction and foam production, which are not easily detected directly from the bulk foam. The main control variable in this study was the protein solution preheating time. As the preheating time increased, the initial void fraction in the column decreased. The initial void fraction of the undenatured solution ranged from about 0.73 to 0.80, and the void fraction for significant preheating times of 5 min ranged from approx 0.68 to 0.72. Furthermore, the period of foam production increased from 5 to 7 min for undenatured proteins in solution to as long 15 min for 5-min preheated solutions. Side-port sampling through a small capillary tube has the potential to be used as a rapid and inexpensive way to determine the level of protein denaturation by directly determining the void fraction and then estimating the effect of denaturation from a protein denaturation calibration curve of the void fraction.
Biotechnology↗
Toxicity of DNA-incorporated iodine-125: quantifying the direct and indirect effects.
To understand the biophysical mechanism(s) underlying the induction of cell death by the decay of the Auger electron emitter iodine-125 in DNA, Chinese hamster V79 lung fibroblasts were labeled with 5-[(125)I]iodo-2'-deoxyuridine ((125)IdU) for two doubling times and frozen and stored at -135 degrees C in the presence of 0.26-3.0 M dimethyl sulfoxide (DMSO), which acts simultaneously as a cryoprotector and a hydroxyl radical scavenger. After the accumulation of (125)I decays, the cells were defrosted and their survival was determined. Within the range of the number of decays examined (up to 470 disintegrations per cell), the survival curves are exponential. The dependence of the D(37) on DMSO concentration is triphasic and seems to reach a plateau at approximately 1.3 M. By extrapolating to infinite DMSO concentration, we estimate the D(37) for maximal hydroxyl radical scavenging to be 411 +/- 36 disintegrations per cell. To determine the D(37) in the absence of DMSO, we extrapolate the D(37) curve to zero concentration, and a D(37) of 54 +/- 5 disintegrations per cell is obtained. The maximal dose modification factor, calculated as the ratio of the D(37) at infinite DMSO concentration (i.e. direct effects only) to the D(37) at zero DMSO concentration (i.e. direct and indirect effects), is 7.6 +/- 1.0. By inference, approximately 90% of the radiotoxic effects of DNA-incorporated (125)I are due to indirect mechanisms.
Animals↗
PTEN/MMAC1 expression in esophageal squamous cell carcinomas.
The PTEN/MMAC1 gene at 10q23.3 is a novel tumor suppressor gene candidate. Various kinds of tumors have mutations in this gene. However, in some cancers PTEN/MMAC1 gene may be inactivated by mechanisms other than gene deletion and mutation, including promoter methylation or translational modification. The aim of this study was to determine whether there are abnormalities in the expression of PTEN/MMAC1 gene in esophageal cancer. Reverse transcription polymerase chain reaction and western blot were used to examine PTEN/MMAC1 expression in human esophageal squamous cell lines and normal cultured esophageal epithelial cells. Immunohistochemical staining was carried out to detect PTEN/MMAC1 expression in surgically resected esophageal squamous cell carcinomas and normal esophageal epithelium. All 30 esophageal cancer cell lines (KYSE series) and normal cultured esophageal epithelial cells expressed PTEN/MMAC1 mRNA. Western blot analysis confirmed that all the cell lines expressed PTEN/MMAC1 protein and there was no difference in expression level. Immunohistochemical study showed that the PTEN/MMAC1 protein was localized dominantly in the cytoplasm and strongly stained in all 42 surgically resected esophageal squamous cell carcinomas and normal esophageal epithelium. PTEN/MMAC1 is rarely associated with esophageal squamous cell carcinoma carcinogenesis.
Carcinoma, Squamous Cell↗
Nifedipine and diltiazem but not verapamil up-regulate endothelial nitric-oxide synthase expression.
We have recently shown that felodipine, a long-acting dihydropyridine L-type calcium channel blocker (CCB), up-regulates nitric oxide (NO) production and endothelial NO synthase (eNOS) expression and activity in cultured endothelial cells as well as in animals with chronic renal failure. This study was intended to compare the effects of prototypes of the three classes of L-type CCBs on the NO system in cultured human coronary artery endothelial cells. Thus, cultured endothelial cells were incubated either with nifedipine, diltiazem, or verapamil for 24 h at 10(-5) to 10(-7) M concentrations. Cells incubated with inactive vehicle served as controls. NO production, as discerned from total nitrate plus nitrite recovered in the medium, was significantly increased by nifedipine (P <.03) and by diltiazem (P <.05). However, NO production remained unchanged with verapamil (P = NS). Similarly, eNOS protein abundance was increased significantly by nifedipine (P <.05) and diltiazem (P <.05). In contrast, eNOS expression was not changed by verapamil (P = NS). Likewise, NOS activity, as measured from [(3)H]L-arginine to [(3)H]L-citrulline conversion, significantly increased with nifedipine (P <.01) and diltiazem (P <.01). However, incubation with verapamil failed to alter NOS activity of the cultured endothelial cells (P = NS). We concluded that prototypes of dihydropyridine and benzothiazepine classes, but not phenylalkylamine class of CCBs, up-regulate the NO system. This may, in part, account for the different biological properties of these agents.
Calcium Channel Blockers↗
Morphological transformation of C3H 10T1/2 cells by 99mTc-cardiolite.
UNLABELLED: The induction of in vitro morphological transformation in C3H 10T1/2 cells by 99mTc-Cardiolite (contents of Cardiolite kit [hexakis(2-methoxyisobutylisonitrile) and other components] plus (99m)Tc generator eluate) was examined. METHODS: Cells were grown for 48 h in the presence of 99mTc-Cardiolite or decayed 99mTc-Cardiolite (99mTc-Cardiolite after 1 wk of storage), and cell survival and transformation were assessed by the colony-forming and focus assays, respectively. X-ray was used as a reference for radiation effects, and 20-methylcholanthrene was used as a positive control for focus formation. RESULTS: Exposure of cells to 99mTc-Cardiolite results in a transformation frequency that is not significantly different from that induced by the volume equivalent of decayed 99mTc-Cardiolite. The number of foci per viable cell increases linearly from approximately 0.17 x 10(-4) in the untreated control to 1.7 x 10(-4) at 37 kBq/mL and 30 x 10(-4) at 1100 kBq/mL 99mTc-Cardiolite or its decayed 99mTc-Cardiolite volume equivalent. Furthermore, exposure of cells to low extracellular concentrations of 99mTc-Cardiolite or decayed 99mTc-Cardiolite (cell survival, > or =88%) induces an approximately 20-fold greater number of transformants per viable cell than that observed after 0.5 Gy x-irradiation, a dose that causes the same level of toxicity. CONCLUSION: Radioactive and decayed 99mTc-Cardiolite induce morphological transformation of C3H 10T1/2 cells in vitro. The underlying mechanism does not seem to be related to the radiation effects of decaying 99mTc but to chemical(s) present in the 99mTc-Cardiolite kit.
Animals↗
Development of an affordable diaphragmatic pump for cardiopulmonary bypass: an in vivo evaluation.
A new diaphragmatic pump (L-Y pump) and its drive unit were developed in our institute. The pump has a priming volume of 80 ml. The pump housing is 72 mm in diameter and 42 mm in height. Its total weight is 139 g. To assess and confirm the function and controllability of this pump, comparative studies of cardiopulmonary bypass (CPB) with L-Y pump (group A) and conventional roller pump (Group B) were performed using dogs. Both pumps provided pump flow of 90 to 100 ml/kg/min. The hemodynamics of both groups were stable and within the normal range. No leakage or thrombus formation was observed in the L-Y pump. All biochemistry data showed no significant differences between the 2 groups. This data demonstrated low plasma-free hemoglobin levels in the L-Y pump group; after 120 min of CPB, mean plasma free hemoglobin levels were 48.7 +/- 8.6 mg/dl in the roller pump group and 21.4 +/- 7.1 mg/dl in the L-Y pump group, and minimal hemolysis was indicated. In conclusion, this L-Y pump and its controller system might be useful for CPB in terms of its low hemolysis and good pump quality. This pump demonstrated easy manipulation, good controllability, and provided a sufficient pulsatile flow. This pump is suitable not only for CPB, but also as a long-term circulatory support system.
Animals↗
[The research and manufacture of the pneumatic left ventricular assist pump].
The manufacturing methods and testing results of the pneumatic left ventricular assist pump(L-Y pump) are introduced in this paper. The results demonstrate that L-Y pump is reliable, biocompatible and in keeping with the clinical requirements.
Animals↗
Fractionated radioimmunotherapy using low doses of iodine-131 labeled anti-CEA monoclonal antibody after tumor volume reduction.
OBJECTIVE: To assess the efficacy of fractionated administration of radiolabeled monoclonal antibody in the treatment of metastases after tumor volume reduction surgery, various experimental therapies were studied comparatively. METHODS: A total of 200 inbred mice received tumor implantation from a murine adenocarcinoma cell line. The mice were randomly grouped to give saline, Arc-a, 131I-C50 in single or fractionated doses, cold C50, or non-specific 131I-IgG with or without surgical removal of the implanted tumor xenograft. RESULTS: In comparison to controls, animals receiving Arc-a and radioactive agents had longer survival, smaller tumor, better clinical condition, and less metastases foci. The best therapeutic response was noted after fractionated doses of 131I-C50, which showed better results in every aspect than those treated with other modalities. The favorable outcome was even more pronounced after tumor volume reduction. CONCLUSIONS: Fractionated dosing may improve the deposition of radiolabeled monoclonal antibody (McAb) and provide the best therapeutic effect on implanted tumor and metastases. Thus fractionated radioimmunotherapy (RIT) after tumor volume reduction might be a practical method with promising therapeutic results.
Animals↗
Different Wnt-5A gene expressions in the renal cell carcinoma GRC-1 cell line during the cell cycle.
OBJECTIVE: To investigate the gene expression at transcription level of growth factor Wnt-5A in different phase during the cell cycle. METHODS: We synchronized the renal cell carcinoma GRC-1 cell line by double thymidine blocks and high-pressure N2O gae methods and amplified Wnt-5A cDNAs from different phase using Semi-quantitative RT-PCR (reverse transcriptase polymerase chain reaction). The PCR products were electrophoresized on the agrose gel and detected by Gel Doc 1000 computer controlled system integrating the volumes of each band, representing the intensities of all pixels in a defined band. RESULTS: The different mRNA expressions of growth factor Wnt-5A was detected in RCC GRC-1 cell line. In S phase, the highest level of Wnt-5A transcript was observed, and in G1 and M phase, medial and lowest, respectively. The differences between S and M stages were statistically significant (P < 0.05). CONCLUSION: Growth factor Wnt-5A has the potential effect on tumorigenesis. It contributes to all phases during cell cycle but in S phase especially.
Carcinoma, Renal Cell↗
Impaired gp-91phox gene expression and dysfunction of peripheral blood neutrophils in patients maintaining hemodialysis.
OBJECTIVE: To investigate expressions of gp-91phox and IL-8 gene and the function of neutrophils in hemodialysis (HD) patients, and to understand the relationship between uremia and immune. METHODS: Gene expression was studied by means of reversal transcription polymerase chain reaction (RT/PCR) from the untreated and treated with lipopolysaccharide (LPS) neutrophils in controls and HD patients. Phagocytosis and bactericidal assays were measured as a decrease in the number of viable intracellular and extracellular bacteria by colony counts. RESULTS: Freshly isolated neutrophils express gp-91phox mRNA in controls while no gp-91phox mRNA was detected in HD patients. When challenged with LPS, gp-91phox mRNA exhibited decreased expression. IL-8 mRNA in HD patients could be spontaneously expressed. Phagocytosis and intracellular killing of neutrophils, when exposed to Staphylococcus aureus, were decreased obviously compared with controls. CONCLUSIONS: The impaired gp-91phox gene expression of neutrophils indicates the impaired NADPH-oxidase system and the untreated neutrophils spontaneously express IL-8 mRNA in the HD patients, which is consistent with suppressed phagocytosis and intracellular killing capacity.
Cell Division↗
[Epidemiological survey and analysis on bronchial asthma in Guangdong Province].
OBJECTIVE: To survey asthma prevalence and risk factors of asthma in Guangdong and then to provide a basic consideration for research and preventive and therapeutic poliaes for control of asthma. METHODS: Using uniform scheme, procedures and questionnaire, performing stratified-cluster-disproportional-random-sampling survey for the population in six areas: Santou, Shenzhen, Zhanjiang, Shaoguan, Fushan and Guangzhou; quantitative sample the prevalence rate quantitated is 1.5% (P = 0.015, q = 0.985), a sampling number stratified = 178 x 0.985/0.015 = 11,689, if the whole province were stratified into six areas, a total of 70,134 persons were supposed to be investigated, in this survey 71,867 subjects were actually examined; all the original data were inputted into soft discs in the same form of data base structure variable definition table, and then were statistically analyzed with spas 8.0 for windows on P III/450 computer, all the prevalence rates were compared by chi 2 test. RESULTS: In this survey 676 asthmatics were found, the overall prevalence rate was 0.94%, the ratio of male to female was 1.38:1; the rate of adults was 0.99% and that of children was 0.73%, three groups with higher prevalence were children of preschool period (age < 7 years, 1.03%), young period (age 18-25 years, 1.00%) and senile period (age 66-75 years, 2.99%); the rate of city (Fushan, 1.38%) was higher than that of rural area (Zhanjiang, 0.47%); the rate of old district (1.70%) was higher than that of the new district (0.23%) in Guangzhou and the rate of historic city (Fushan, 1.38%) was higher than that of the newly developed city (Shenzhen, 0.64%); risk factors found among 676 asthmatics, persons keeping pets (cat, dog, fowl, bird) in home were reported by 46.0% (311/676), those keeping cat was 43.1% (134/311), particularly those keeping cat and both cat and dog accounted for 61.7% (192/311). Persons often exposed to side-stream smoke were reported by 54.7%. Asthmatics with allergic rhinititis were reported by 38.2%. The attack contributed to change temperature or to inhale cold air was 41.6% respectively. CONCLUSION: This survey had basically reflected the distribution, Frequency and intensity of asthma, the overall prevalence rate was 0.94% from which it would be estimated that there could be 670,000 asthmatics in Guangdong; the relative data will provide basis for research work concerned and mass prevention and treatment of asthma.
Adolescent↗
[Effects of estrogen on experimental tooth movement in osteoporosis rats].
OBJECTIVE: To investigate the effects of estrogen on the orthodontic tooth movement and alveolar bone in osteoporosis rats. METHODS: Thirty 3 month-old female sprague-dawley rats were divided randomly into three groups (control, osteoporosis and estrogen). In the three groups, the distances of tooth movement and the number of osteoclast were measured and compared. Histologic changes were observed. RESULTS: Compared with the control group, in first month, the distances of orthodontic tooth movement was increased by 43.3% in osteoporosis group and by 30.7% in estrogen group; the number of osteoclast was increased by 64.4% and by 32.9% respectively. In second month, the distances were increased by 68.5% in osteoporosis group and by 24.9% in estrogen group; the number of osteoclast was increased by 68.7% and by 15.0% respectively. In addition, estrogen promoted the alveolar bone-forming and inhibited the bone resorption. CONCLUSION: It is suggested that the estrogen may affect the rate of orthodontic tooth movement on postmenopausal osteoporosis patient.
Animals↗
Bilateral pallidotomy for treatment of idiopathic Parkinson's disease.
OBJECTIVE: To clarify the benefits and risks of patients undergoing bilateral posteroventral pallidotomy (BPVP) for patients with idiopathic Parkinson's disease (PD) and the differences between contemporaneous BPVP (CBPVP) and staged BPVP (SBPVP). METHODS: Twenty patients underwent microelectrode-guided CBPVP and 26 SBPVP for bilateral PD symptoms. The data were retrospectively reviewed. Unified Parkinson's Disease Rating Scale (UPDRS) was used to evaluate the effects of these operations. RESULTS: BPVP, either CBPVP or SBPVP, significantly improved patients' bilateral PD symptoms (P < 0.001). The improvement was consistently higher in "off" state than in "on" state. No statistical difference was observed in the improvement percentages of CBPVP, SBPVP1 and SBPVP2. CBPVP contributed greatly to L-dopa induced side effects (part IV). BPVP, SBPVP1, and SBPVP2 significantly improved cardinal parkinsonian signs but no difference was found among them. One patient after CBPVP developed hypophonia and swallowing problem, while 2 patients after SBPVP sustained hypophonia. These conditions were improved 3 months later. CONCLUSIONS: BPVP may significantly improve bilateral signs of PD. It is safer than bilateral thalamotomy. CBPVP is applicable to some patients. BPVP may not cause mental impairment but shows a higher incidence rate of hypophonia. The practice of BPVP requires a refined surgical technique and a better understanding of pathophysiology of the basal ganglia.
Adult↗