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Biomedical subjects

Y Yu

Publications and source records attributed to Y Yu.

At least 127 records · Page 7Linked to original sources
PubMed2001

Acute effect of human cardiotrophin-1 on hemodynamic parameters in spontaneously hypertensive rats and Wistar Kyoto rats.

There is considerable evidence to indicate that humoral factors play an important role in the development of left ventricular hypertrophy. Cardiotrophin-1 (CT-1) is a cytokine that has been shown to induce cardiac hypertrophy in a dose-dependent manner. The aim of the present study was to investigate the acute effect of CT-1 on hemodynamic parameters in spontaneously hypertensive rats (SHR) and Wistar Kyoto rats (WKY) and to study the relationship between the plasma concentration of CT-1 and its hemodynamic effect. Ten-week-old SHR and age-matched WKY were used. Blood pressure (BP), heart rate (HR) and plasma concentration of CT-1 were measured both before and for 60 min after intravenous bolus injection of human CT-1 (10 microg/kg). CT-1 injection significantly decreased BP and significantly increased HR in SHR and WKY. There were significant differences in BP and HR between the two groups at all time points after injection. The lowest BP, highest HR and maximal plasma concentrations of CT-1 were observed in both groups within 10 min after injection. However, after converting the values into the percentage change from their respective baselines, there were no significant differences between the two groups in BP or HR at any time point. There was also no significant difference between the two groups at any time point in the plasma concentration of CT-1. This study indicates that CT-1 decreases BP and increases HR in both SHR and WKY. The most obvious change occurred within 10 min after injection. However, there was no significant difference in the hypotensive effect of CT-1 on 10-week-old SHR and WKY.

Animals↗
PubMed2001

Regulation of the expression of CD45 isoforms in the Farage human B cell lymphoma line and its 10.6.1 subline.

Different B-cell neoplasias vary in the expression of CD45 isoforms. In the present study two sublines of a human B cell lymphoma- the original Farage line (Farage OL) and the Farage 10.6.1 subline were used to analyze the regulation of the expression of CD45 cell surface determinants. Cells of the Farage OL line constitutively expressed both CD45RO and CD45RA determinants on their cell surface. In contrast, the majority of the cells of the Farage 10.6.1 subline expressed CD45RA, and only few cells were CD45RO+. The low molecular spliced CD45 mRNA, characteristic for CD45RO was found in Farage OL cells, but was almost undetectable in Farage 10.6.1 cells. Following exposure to interleukin-4 (IL-4) a large proportion of the Farage 10.6.1 cells expressed CD45RO while in Farage OL cells the proportion of CD45RO+ was slightly reduced. The low molecular, spliced mRNA characteristic for CD45RO, was increased in Farage 10.6.1 cells following IL4 stimulation, but was slightly reduced in Farage OL cells. The molecular weight of CD45RA molecules produced by Farage cells varied from 185 kDa to 220 kDa while that of CD45RO molecules was 175 kDa. Preliminary attempts were made to determine a possible correlation between the expression of CD45RO and apoptosis in Farage cells. In both the Farage OL and Farage 10.6.1 cells the proportion of Bcl-2+ cells was lower among CD45RO+ cells than among CD45RO- cells. The present study indicates that IL4 has different effects on the alternative splicing of CD45 mRNA in two closely related B cell lymphoma lines. Thus, factors produced by the B lymphoma cells themselves may endow the cells with different patterns of responsiveness to a single stimulatory agent.

Blotting, Western↗
PubMed2001

Antisense of ATP synthase subunit e inhibits the growth of human hepatocellular carcinoma cells.

Differentially expressed genes between normal and hepatocellular carcinoma tissues were investigated using differential display. We identified a cDNA fragment that was overexpressed in cancer tissue. Homology analysis showed that the sequence was identical to human ATP synthase subunit e (hAS-e). Moreover, Northern blot analysis demonstrated that hAS-e was overexpressed in 10 of 11 (91%) specimens of hepatocellular carcinoma compared with corresponding normal tissues. We introduced antisense hAS-e into a human hepatocellular carcinoma BEL-7404 cell and found that downregulation of the hAS-e led to cell growth inhibition. It was also found that the antisense transfection could decrease the serum-stimulated activation of mitogen-activated protein kinase (MAP kinase). Together, the results suggest that antisense of hAS-e can inhibit cell proliferation through the MAP kinase pathway. Our data indicate that hAS-e may become a new target in gene therapy.

Base Sequence↗
PubMed2001

The role of bladder afferent pathways in bladder hyperactivity induced by the intravesical administration of nerve growth factor.

PURPOSE: Interstitial cystitis, a chronic disease of the bladder, is characterized by urinary frequency, urgency and suprapubic pain. Nerve growth factor is a substance that may sensitize afferent nerves and induce bladder hyperactivity. It is often increased in the urine of patients with interstitial cystitis. We evaluated the role of Adelta and C fiber afferents in the type of bladder hyperactivity induced by the intravesical administration of nerve growth factor. MATERIALS AND METHODS: A total of 22 Wistar and 8 Sprague-Dawley adult female rats were anesthetized with 1.2 gm/kg urethane given subcutaneously. A transurethral catheter was inserted into the bladder. Some animals were pretreated with 125 mg/kg capsaicin injected subcutaneously 4 days before nerve growth factor administration. Cystometry was performed by slowly filling the bladder at a rate of 0.04 ml per minute for 15 minutes with a volume of up to 0.6 ml. Parameters measured included volume threshold and pressure threshold for inducing the micturition reflex, compliance, bladder contraction amplitude, number of contractions and the inter-contraction interval. Nerve growth factor (0.5 ml of 20 microg/ml in 10% dimethyl sulfoxide) or a vehicle solution (0.5 ml of 10% dimethyl sulfoxide) was infused into the bladder through a transurethral catheter and retained for 1 hour. RESULTS: In Wistar rats nerve growth factor increased the mean number of contractions by 111% versus controls (5.7 versus 2.7, p <0.05), and decreased the mean volume threshold by 41% (0.244 versus 0.412 ml, p <0.05). This effect of nerve growth factor was not detected in Sprague-Dawley rats. Capsaicin pretreatment increased the volume threshold by 59% but did not change nerve growth factor induced bladder hyperactivity. CONCLUSIONS: The intravesical application of nerve growth factor acutely induced bladder hyperactivity in Wistar but not in Sprague-Dawley rats. Because the C fiber afferent neurotoxin capsaicin did not change the effect of nerve growth factor, we believe that Adelta afferent neurons have a major role in nerve growth factor induced bladder hyperactivity.

Administration, Intravesical↗
PubMed2001

Aminoguanidine and ramipril prevent diabetes-induced increases in protein kinase C activity in glomeruli, retina and mesenteric artery.

This study investigated the effects of insulin therapy, inhibition of advanced glycation end-product formation with aminoguanidine and angiotensin-converting enzyme inhibition with ramipril on diabetes-related increases in protein kinase C (PKC) activity in the streptozotocin-diabetic rat. PKC activity in the glomeruli, retina and mesenteric artery was increased by 1.5-2-fold after induction of diabetes, and this increase was maintained over 24 weeks. Treatment with insulin at 2 units or 6 units per day attenuated glomerular PKC in proportion to the level of glycohaemoglobin after 4 weeks of diabetes (r=0.68, P<0.0001). The higher dose of insulin prevented the diabetes-related increase in glomerular PKC activity, although blood glucose levels were not normalized. After 8 weeks of diabetes, ramipril completely prevented the diabetes-related increases in PKC activity in the glomeruli, retina and mesenteric artery. By contrast, aminoguanidine treatment resulted in no inhibition of glomerular PKC activity, partial inhibition of retinal PKC activity and complete inhibition of mesenteric artery PKC activity. After 24 weeks of diabetes, both aminoguanidine and ramipril prevented the diabetes-related increases in PKC activity in all three tissues, in parallel with suppression of albuminuria by both agents. Aminoguanidine also prevented diabetes-related increases in retinal permeability at 16 weeks. These results suggest that the organ-protective effects of insulin, aminoguanidine and ramipril in diabetes may be mediated, at least in part, through the differential inhibition of PKC activity in various tissues.

Angiotensin-Converting Enzyme Inhibitors↗
PubMed2001

[Reconstruction of hepatitis D virus ribozymes and their ability to trans-cleave hepatitis C virus RNA].

OBJECTIVE: To study whether reconstructed hepatitis D virus (HDV) ribozymes have the ability to trans-cleave hepatitis C virus (HCV) RNA. METHODS: We reconstructed the stem IV and substrate-binding region of HDV genomic ribozymes, thus obtained three HDV ribozymes named RzC1, RzC2 and RzC3 expected to be able to trans-cleave HCV RNA at predicted sites. The substrate containing HCV RNA 5'-noncoding region (5'-NCR) and 5'-fragment of C region (HCV RNA 5'-NCR-C) was synthesized by transcription in vitro, then radiolabelled at its 5'-end. Under certain pH and appropriate concentration of Mg(2+) with or without deionized formamide, the ribozymes and their substrate were mixed at mol ratio of 100 : 1 and reacted for two hours. Trans-cleaved products were shown by denatured polyacrylamide gel electrophoresis and autoradiography, and the percentage of trans-cleaved substrate was calculated as the activity indicator of these ribozymes. RESULTS: RzC1 and RzC2 were able to trans-cleave HCV RNA 5'-NCR-C site specifically, and their activity could be enhanced by certain concentration of deionized formamide. RzC3 could not trans-cleave the substrate. CONCLUSIONS: Optimized HDV genomic ribozymes can trans-cleave HCV RNA.

5' Untranslated Regions↗
PubMed2001

[Complete genome sequence analysis of the Hantavirus Z10 strain].

OBJECTIVE: Study on the complete genome sequence of Hantavirus Z10 strain which has been applied for inactivated vaccine production in China, to assess its molecular characteristics and the diversity with other hantaviruses. METHODS: The total RNA were prepared from Z10 virus infected cells and the RT-PCR products was cloned into T vector, sequenced and analyzed by using DNASTAR software. RESULTS: The Z10 complete genome, L segment is 6,553, M segment is 3,615, S segment is 1,701 nucleotides in length, with a single open reading frame encoding 2,151, 1,135, 429 amino acids respectively. Sequence homology comparison showed that the 3 segment nucleotide of Z10 strain were close to HTN type virus, but only 83.6-87.4% homology with other HTN viruses at the nucleotide level. The phylogenetic analysis was made on their nucleotide and amino acid sequences. CONCLUSION: The results firstly demonstrates that Z10 strain is a new subtype of the Hantaan(HTN) type.

Amino Acid Sequence↗
PubMed2001

[UV photolysis mechanism of CCl4 and CHCl3 in water].

The photolysis mechanism of CCl4 and CHCl3 in water was studied by using transient absorption spectra. The results showed that aqueous CCl4 was dissociated into CCl3 and Cl radicals by 248 nm laser, and CHCl3 was dissociated into CHCl2 and Cl radicals after adding C6H6. The radicals CCl3 and CHCl2 were able to react with O2 to form CCl3O2 and CHCl2O2 respectively, or to form C2Cl6 and C2H2Cl4 without O2. The rate coefficients of some reactions were obtained.

Carbon Tetrachloride↗
PubMed2001

[Chromosomal aberration analyzed by comparative genomic hybridization in nasopharyngeal carcinoma].

OBJECTIVE: To identify genetic alteration in primary sporadic nasopharyngeal carcinoma(NPC) in Hunan. METHODS: Comparative genomic hybridization was applied to investigate the genomic imbalance in a series of 20 cases of primary nasopharyngeal carcinomas. RESULTS: The common chromosomal alterations included gains of chromosomes 1q, 2, 3q, 7q,8q,12 as well as losses of chromosomes 3p, 9p, 11q, 16q. CONCLUSION: There are multiple regions of chromosomes with copy number changes in NPC. The tumor suppressor genes and oncogenes on these regions may be involved in the development and progress of nasopharyngeal carcinoma.

Chromosome Aberrations↗
PubMed2001

[Mutations of mitochondrial 12S rRNA gene in type 2 diabetes].

OBJECTIVE: To investigate mutations at points 1310, 1438 and 1442 of mitochondrial 12S rRNA gene in Chinese type 2 diabetes and screen for new mutations associated with type 2 diabetes in this area. METHODS: The mitochondrial DNAs (mtDNAs) of 86 patients with type 2 diabetes and those of 70 normal controls were analyzed using PCR-SSCP and PCR product direct sequencing technique. RESULTS: One patient was found with the mitochondrial DNA G --> A mutation at point 1438, and one with the G two head right arrow A mutation at point 1442, whereas none of the normal controls was found to have mutation at these two points. No C --> T mutation at nucleotide pair 1310 of the mitochondrial 12S rRNA gene was identified. CONCLUSION: The G --> A mutation at points 1438 and 1442 is likely to be associated with the development of type 2 diabetes; the occurrence of the C -->T mutation at point 1310 is probably rare in the blood cells, and the development of type 2 diabetes may be related to heterogeneity in mitochondrial genetic changes.

Adult↗
PubMed2001

Overexpression of gamma-aminobutyric acid transporter subtype I leads to cognitive deterioration in transgenic mice.

AIM: To explore the physiological role of gamma-aminobutyric acid transporter subtype I (GAT1) in cognition. METHODS: Transgenic mice were produced by pronuclei microinjection method. Integration of transgene was identified by Southern-blot and PCR analysis in various generations. Level of GAT1 mRNA in a variety of tissues was evaluated by semi-quantitative RT-PCR analysis. GAT1 protein was detected by immunofluorescence and histochemistry analysis. Associative learning capacity was analyzed by conditioned avoidance task. Memory retention was assessed by novel object recognition test. Morphology of synaptosomes was examined by electron microscope. RESULTS: Four independent founder mice bearing various copies of transgene were generated. GAT1 was evidently overexpressed at both mRNA and protein level in a variety of tissues from transgenic mice. In comparison with wild-type mice, transgenic mice exhibited significantly declined associative learning capacity (P < 0.01) and decreased memory retention (P < 0.01 in 1-h-retention, and P < 0.05 in 1-d-retention). In addition, the amount of asymmetric synapses in the brain of transgenic mice was reduced approximately by 24 %, relative to wild-type mice. CONCLUSION: Overexpression of GAT1 in mice results in cognitive deterioration, indicating that the alteration in the expression of gamma-aminobutyric acid transporters is involved in the pathophysiological mechanism underlying some cognitive deficiencies.

Animals↗
PubMed2001

Inhibitory role of GDP on saikosaponin (I) stimulated enzymes secretion and rising of [Ca2+]i in rat pancreatic acini.

AIM: To study the role of guanosine diphosphate (GDP) on enzyme secretion and rising of [Ca2+]i in saikosaponin (I) [SA(I)] stimulated rat pancreatic acini. METHODS: Cell membrane of isolated rat pancreatic acini were permeabilized using streptolysin O (SLO). Enzymes secretions were indicated by detecting total protein secretions. Intracellular Ca2+ ([Ca2+]i) was measured using Fluo-3 in SPEX spectrofluorimeter. RESULTS: The inhibition of GDP on SA(I) stimulated enzymes secretion increased with increasing GDP concentration. There were two peaks in the time course of increase in [Ca2+]i evoked by SA(I) 10 micromol/L. After adding GDP 5 mmol/L, [Ca2+]i rose gradually without the two peaks. In permeabilized acini, the accumulation of enzymes stimulated by SA(I) in 30 min reduced by 57 % compared with intact acini. GDP 5 mmol/L decreased the initial rate of secretion. CONCLUSION: Inhibition of GDP on increase in [Ca2+]i reduces SA(I) stimulated enzymes secretion in pancreatic acini.

Animals↗
PubMed2001

[Preliminary approach to environmental risk assessment of drainage projects during oilfield exploitation in Daqing].

A qualitative analysis was made to assess the environmental risk and its impact of alternative drainage projects around Yong-5 oil-transport station at Yongle oilfield in Daqing. On the basis of this, a method of fuzzy comprehensive assessment was applied to set up corresponding indexes, to determine hazard environmental coefficients, and to calculate the environmental risk fuzzy assessment indexes which reflect the relative risk degrees of alternative drainage projects. The measures on environmental risk management were proposed according to the priority of alternative projects.

China↗
PubMed2001

[Changes in serum neopterin levels in patients after trauma].

OBJECTIVE: To evaluate the clinical significance of changes in serum neopterin levels in patients after trauma. METHODS: 41 patients with mechanical injury were divided into three groups according to the injury severity score (ISS). In all patients, blood collection was started within 24 h after injury, and blood samples were obtained at 3, 7, 14, and 21 d post-trauma. The relationship was determined between serum neopterin levels and ISS, multiple organ dysfunction syndrome (MODS) and prognosis in patients. RESULTS: Patients with ISS > or = 25 showed a high neopterin level compared with those with ISS < 16 (P < 0.05 or P < 0.01), and a correlation between mean neopterin levels and ISS was observed in severely injured patients (r = 0.518, P < 0.05). High neopterin levels were measured in patients who developed MODS, showing a persistent marked elevation from day 3 post-trauma onward. The difference between MODS and non-MODS patients was significant on days 3, 7, and 14 after acute insults (P < 0.05 or P < 0.01). In addition, serum neopterin levels of patients with fatal outcome were much higher than those of surviving patients, and it exceeded 50.0 nmol/L in most cases prior to termination (8/12 cases, 66.7%). CONCLUSIONS: Mechanical injury can cause a constant increase in neopterin level, implying an intact reaction by T lymphocytes and macrophage axis. The measurement of serum neopterin might serve as a tool for the evaluation of injury severity, early detection of MODS as well as prediction of outcome in patients after trauma.

Adult↗
PubMed2001

[An analysis of the clinical and pathological characteristics of mu-tong (a Chinese herb) induced tubulointerstitial nephropathy].

OBJECTIVES: To investigate the clinical and pathological characteristics of Mutong (a Chinese herb, caulis aristolochiae manshuriensis) induced tubulointerstitial nephropathy (MT-TIN), and analyze the related to renal function decline and clinical prognosis. METHODS: 51 patients with MT-TIN were studied retrospectively. They were divided into acute, mild chronic and severe chronic groups according to the pathological lesion. Clinical and pathological data were semi-quantitatively assessed. Correlation and regression of the parameters were further tested. Relationship between medication and the illness, incidence, clinical characteristics, therapy and regression of the disease were analyzed. The results of the acute group of MT-TIN were compared with those of the antibiotics-induced acute tubular necrosis (A-ATN) and acute interstitial nephritis (A-AIN). RESULTS: The common clinical symptoms of MT-TIN were fatigue, polyuria, nocturia, usually accompanied by renal tubular dysfunction with or without an elevated serum creatinine (Scr) level. It was rare to find urine abnormality and anemia in the acute and mild chronic groups. The pathological examination of MT-TIN revealed that there were severe degradation, necrosis and collapse of the renal epithelial cells leaving the basement membrane naked. Regeneration was rarely seen as in A-ATN. Cellular infiltrate in the interstitium was also rarely seen as in A-AIN. However, marked tubular atrophy and early occurrence of diffuse interstitial fibrosis were detected in the chronic groups. Correlation and regression tests showed that the level of Scr correlates obviously with the degree of anemia and renal interstitial fibrosis. After withdrawal of medication containing MT, most patients' Scr level became steady within 2 months. Both the clinical and pathological characteristics were different with those of A-ATN or A-AIN. Most of the patients suffering from MT-TIN got the disease by over-dose or long-term taking of medicines containing Mu-Tong. Few patients had it when taking regular dose of the medicine. CONCLUSION: MT-TIN is a special type of drug-induced tubulointerstitial nephropathy, which is mainly related to over-dose or long-term taking of Mu-Tong, which contains aristolochic acid. One should try to avoid using Mu-Tong containing aristolochic acid and pay attention to monitor the renal function if the medication has to be given.

Adult↗
PubMed2001

Arsenic trioxide induces multiple myeloma cell apoptosis via disruption of mitochondrial transmembrane potentials and activation of caspase-3.

OBJECTIVE: To investigate the response of multiple myeloma (MM) cells to arsenic trioxide (As2O3) and their possible mechanisms. METHODS: Two MM-derived cell lines RPMI8226 and U266 cells were used as in vitro models. Cell apoptosis was assessed by morphology, flow cytometry, and DNA gel electrophoresis. Mitochondrial transmembrane potentials (delta psi m) were evaluated by measuring cellular Rhodamine 123 staining intensity. Protein expression was analyzed using Western blot. RESULTS: Zero point one to 0.5 mumol/L As2O3 inhibited cell proliferation and 2.0 mumol/L As2O3 induced cell apoptosis, while 1.0 mumol/L As2O3 inhibited proliferation with a weak degree of apoptosis induction in RPMI8226 and U266 cell lines. As2O3-induced apoptosis was accompanied by mitochondrial transmembrane potentials (delta psi m) collapse and caspase-3 activation in the presence of intact membrane. Glutathione depleter buthionine sulfoximine enhanced, while disulfide bond-reducing agent dithiothreitol partially antagonized As2O3-induced delta psi m collapse and apoptosis in MM cells. All-trans retinoic acid (ATRA) could also induce apoptosis in RPMI8226 cells, but it did not show any cooperative effects with As2O3. CONCLUSION: As2O3 exerts apoptosis-inducing and growth-inhibiting effects on MM cells, and mitochondrium is a pivotal and common target of As2O3 for apoptosis induction.

Antineoplastic Agents↗
PubMed2001

Changes in intestinal microflora in patients with chronic severe hepatitis.

OBJECTIVE: To investigate changes in intestinal microflora in patients with chronic severe hepatitis (CSH), and their role in this life-threatening disease. METHODS: We classified nineteen patients with chronic severe hepatitis as the CSH group, thirty patients with chronic hepatitis (CH) as the CH group and thirty-one healthy volunteer as the control group. Fecal flora from all subjects were analyzed. Concentrations of plasma endotoxin, serum cytokines tumor necrosis factor alpha (TNF-alpha) and interleukin-1 beta (IL-1 beta) and liver function were assessed. RESULTS: The number of fecal bifidobacterium (P < 0.001, P < 0.05 respectively), as well as bacteroidaceae (P < 0.001, P < 0.01 respectively) were significantly deceased in patients with chronic severe hepatitis compared with the CH and control groups, while the number of enterobacteriaceae (P < 0.001, P < 0.05 respectively) and yeasts (P < 0.01, P < 0.05 respectively) were significantly increased. Levels of plasma endotoxin, serum TNF-alpha, IL-1 beta and total bilirubin (TBiL) were significantly increased in the CSH group. The concentration of endotoxin positively correlated with levels of both TNF-alpha, IL-1 beta and TBiL (P < 0.001, respectively). Levels of plasma endotoxin were positively correlated with the number of fecal enterobacteriaceae and negatively correlated with bifidobacterium (P < 0.05, P < 0.001, respectively). CONCLUSION: Intestinal flora in patients with chronic severe hepatitis were severely disturbed and gut microbiological colonization resistance was impaired. Changes in intestinal flora may have a pivotal role in both the elevation of plasma endotoxin and further hepatic lesions resulting in liver failure.

Adult↗