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Gang Ye

Publications and source records attributed to Gang Ye.

At least 19 recordsLinked to original sources
PubMed2026

Discovery of specific rhizosphere bacteria Rhodanobacter involved in KAI2-mediated drought tolerance in Arabidopsis.

The KARRIKIN INSENSITIVE 2 (KAI2) receptor has been reported to contribute to drought tolerance in Arabidopsis. However, the extent to which KAI2's function in drought tolerance depends on soil microbiota remains unclear. This study demonstrates that the rhizosphere microbiome is indispensable for KAI2-mediated drought tolerance. We isolated specific Rhodanobacter sp. and confirmed its role in enhancing drought tolerance in Arabidopsis. Notably, Rhodanobacter sp. was found to specifically secrete the key isoflavone daidzin. We found that daidzin had a similar function with KAI2 agonist, desmethyl-type germinone, and induced interaction between KAI2 and SUPRESSOR OF MORE AXILLARY GROWTH 2 1. Moreover, the exogenous application of daidzin enhanced drought tolerance by modulating the expression of karrikin response and drought-related genes, in a KAI2-dependent manner. Our findings suggest that the rhizosphere microbiome plays a crucial role in facilitating KAI2-mediated drought tolerance in Arabidopsis, with Rhodanobacter sp. contributing through the secretion of daidzin.

Arabidopsis↗
PubMed2006

Hypomethylated P4 promoter induces expression of the insulin-like growth factor-II gene in hepatocellular carcinoma in a Chinese population.

PURPOSE: The expression of human insulin-like growth factor-II (IGF-II) is regulated by the activation of four promoters (P1-P4) acting in a development-dependent, tissue-specific manner. IGF-II overexpression associated with P3 and P4 activation is observed in animal and human hepatocarcinogenesis. We correlated P4 epigenetic alteration with P4 transcript activation and clinicopathologic features. EXPERIMENTAL DESIGN: We analyzed P4 epigenetic alteration using methylation-specific PCR in 34 hepatocellular carcinoma (HCC) specimens, 34 matched adjacent nontumor specimens, and 8 normal adult liver specimens. The data were correlated with activation of P4 transcription by using reverse transcription-PCR. Epigenetic alteration was compared with patients' clinicopathologic features. RESULTS: Compared with normal liver tissue, hypomethylation of P4 CpG islands was significantly more frequent in HCC (P = 0.03) and matched tissues (P = 0.047). P4 mRNA levels in HCC with unmethylated alleles were significantly higher than in HCC without unmethylated alleles (P = 0.001); P4 mRNA levels in matched nontumor tissues with unmethylated alleles were significantly higher than in matched nontumor tissues without unmethylated alleles (P = 0.005). P4 hypomethylation in HCC was associated with portal vein tumor embolus (P = 0.017) and poorer tumor differentiation (P = 0.025). CONCLUSIONS: These findings suggest that IGF-II P4 hypomethylation may be an early and frequent event and that it may contribute to P4 transcription expression activation during the transformation of a premalignant liver lesion to HCC. Furthermore, aberrant hypomethylation of P4 CpG islands not only may play an important role during hepatocarcinogenesis but might also be a useful biomarker for poor prognosis of patients with HCC.

Adult↗
PubMed2006

Differential promoter usage for insulin-like growth factor-II gene in Chinese hepatocellular carcinoma with hepatitis B virus infection.

BACKGROUND: Human insulin-like growth factor-II (IGF-II) gene contains nine exons and four different promoters (P1-P4). Expression of the gene is elevated in the preneoplastic hepatic foci and hepatocellular carcinoma (HCC) of experimental animals and humans. To gain insight into transcriptional regulation of the gene in HCC, we analyzed the relative usage of the P1-P4 promoters and its correlation with the clinical and pathological characteristics in Chinese hepatocellular carcinoma with hepatitis B virus (HBV) infection. METHODS: P1-P4 usage levels of the gene in tumorous and matched adjacent nontumorous tissues from 23 HCC patients and 7 normal liver tissues were evaluated using a semiquantitative reverse-transcription polymerase chain reaction (RT-PCR) assay. The mutation status of p53 gene in HCC tissues was analyzed by PCR and sequencing. RESULTS: Transcripts from P1 were not detectable in 65.2% HCC tissues, and were expressed at low levels or not expressed in all nontumorous tissues compared with normals, but P2 usage levels showed no differences. P3 and P4 expression was significantly increased in most of HCC and almost all adjacent nontumorous tissues. There was a positive association of expression levels of both P3 and P4 transcripts in HCC tissues with the p53 mutation and presence of tumor embolus of portal vein, and expression of P3 were negatively related to differentiation of HCC. However, expression of both P3 and P4 was not associated with other parameters. CONCLUSIONS: Loss of P1 activity and reactivation of P3 and P4 are important characteristics in most of Chinese HCC with HBV infection, and increased IGF-II expression from P3 and P4 may play an active role in early proliferation of precancerous liver cells and hepatocarcinogenesis of these cases. Significant increase in fetal transcripts is associated with the p53 mutation and poor prognosis of the HCC patients and might serve as one of identification parameters of poor HCC prognosis.

Adult↗
PubMed2006

Arterial anastomosis without sutures using ring pin stapler for clinical renal transplantation: comparison with suture anastomosis.

PURPOSE: The metal ring pin stapler was initially developed for microvascular surgery and there has been little experience of their use in larger vessels. We determined if the titanium ring pin coupling system could be safely and rapidly applied for arterial reconstruction in clinical renal transplantation. MATERIALS AND METHODS: The donor renal artery was end-to-end anastomosed to the internal iliac artery with titanium ring pin staplers in 36 patients. Anastomotic, clamp and total operative time and vascular problems were compared with those in the control group of sutured anastomosis in 39 transplant recipients. RESULTS: The completion of mechanical anastomosis required half the time of suture anastomosis. Mean clamp time was 17.8 minutes in the nonsuture group and 28.1 minutes in the control group. There was no significant difference in total operative time between the 2 groups. A small anastomotic line leak was noted in each group, which was temporary and self-limited. There were no postoperative anastomotic failures, postoperative bleeding episodes or need to revise the anastomosis (100% patency rate) in the 2 groups. Of the patients 61 were followed for 2 to 5 years. Transplant renal artery stenosis was observed in 1 patient in the nonsuture group but 3 in the control group. CONCLUSIONS: The anastomotic technique with the ring pin system is safe and simple, permitting an expeditious and everting anastomosis with a smooth intima-to-intima junction. Application of this technique may decrease warm ischemia time and the incidence of anastomotic artery stenosis, thus, improving outcomes.

Adult↗
PubMed2006

An efficient forward solver in electrical impedance tomography by spectral element method.

In electrical impedance tomography (EIT), a forward solver capable of predicting the voltages on electrodes for a given conductivity distribution is essential for reconstruction. The EIT forward solver is normally based on the conventional finite element method (FEM). One of the major problems of three-dimensional (3-D) EIT is its high demand in computing power and memory since high precision is required for obtaining a small secondary field which is typical for a small anomaly. This accuracy requirement is also set by the level of noise in the real data; although currently the noise level is still an issue, future EIT systems should significantly reduce the noise level to be capable of detecting very small anomalies. To accurately simulate the forward solution with the FEM, a mesh with large number of nodes and elements is usually needed. To overcome this problem, we proposed the spectral element method (SEM) for EIT forward problem. With the introduction of SEM, a smaller number of nodes and hence less computational time and memory are needed to achieve the same or better accuracy in the forward solution than the FEM. Numerical results demonstrate the efficiency of the SEM in 3-D EIT simulation.

Algorithms↗
PubMed2006

[RDP1258 on proliferation of rat splenocytes in vivo].

AIM: To explore the immunosuppressive effects of a novel HLA-derived peptide, RDP1258, on rat splenocyte proliferation in vivo and its underlying mechanisms. METHODS: RDP1258 was synthesized through artificial solid-phase synthesis method. Its effects on proliferative reaction of rat splenocytes in vivo were observed by (3)H-TDR incorporation method. And its effects on the heme oxygenase(HO) enzyme activity were analyzed by enzyme chemistry method. RESULTS: The results showed that the synthetic HLA-derived peptide RDP1258 obviously inhibited the proliferation of rat splenocytes stimulated by isoantigen and mitogen. In vivo administration of RDP1258 peptide to rats resulted in upregulation of splenic HO activity and rapid upregulation of HO-1 protein expression. CONCLUSION: HO-1 might participate in RDP1258 inhibiting the proliferation of rat splenocytes induced by mitogen and isoantigen in vivo.

Animals↗
PubMed2005

Outpatient procedures on the glans and anterior urethra under a new local anaesthesia: intracorpus spongiosum anaesthesia.

OBJECTIVE: To determine the efficacy of intracorpus spongiosum anaesthesia during minor procedures on the glans and anterior urethra in the outpatient clinic. METHODS: Sixty-nine consecutive male patients underwent various procedures on the glans penis or anterior urethra under intracorpus spongiosum anaesthesia, which was performed by injection of 3 mL of 1% lidocaine into the glans penis. The effect of this anaesthetic technique was assessed by questionnaire using a pain scale. RESULTS: Following injection of lidocaine, the anaesthetic effect was immediate and very satisfactory. The minor procedures, varying from 8 to 68 minutes in duration, were successfully completed under the new local anaesthesia. Of the 69 patients, 63 (91.3%) felt no pain and six (8.7%) reported either minor or moderate discomfort that was tolerable and could be ignored. There were no serious complications with this anaesthetic technique except for three patients (4.3%) who had instantaneous trance during lidocaine injection. CONCLUSION: Intracorpus spongiosum anaesthesia is an effective, simple, safe anaesthetic technique for minor procedures on the glans and anterior urethra in an outpatient setting. With this new local anaesthesia, the total cost of many procedures on the glans and anterior urethra can be markedly reduced.

Adolescent↗
PubMed2005

Use of a new local anesthesia--intracorpus spongiosum anesthesia--in procedures on anterior urethra.

BACKGROUND: Urologists often perform procedures on anterior urethra, which is one of the most sensitive parts in male patients. The aim of the present study was to determine the efficacy of intracorpus spongiosum anesthesia during procedures on anterior urethra in the outpatient clinic. METHODS: A dosage of 3 mL of 1% lidocaine was slowly injected into the glans penis of 51 male patients. Immediately following injection, they underwent different procedures on anterior urethra. The subjective experience of pain in the patients was assessed by questionnaire according to a pain scale. RESULTS: Forty-seven patients (92.16%, 47/51) had zero pain and four cases (7.84%) had either minor or moderate discomfort, which was limited and tolerable. The anesthetic effect is immediate and has been very satisfactory. All the procedures (mean duration, 33 min), were successfully completed under the intracorpus spongiosum anesthesia. The act of injection into the glans caused instantaneous minor pain in 45 patients (88.23%, 45/51), moderate pain in four patients and no pain in two patients. There were no serious complications with this anesthetic technique, although two cases had instantaneous trance during injection of lidocaine. CONCLUSIONS: Minor procedures on anterior urethra in an outpatient setting with intracorpus spongiosum anesthesia are generally painless, safe, simple, successful and inexpensive compared to those performed in a hospital.

Adolescent↗
PubMed2005

Cardiomyocyte defects in diabetic models and protection with cardiac-targeted transgenes.

Diabetic cardiomyopathy is a common chronic complication leading to heightened risk of heart failure among diabetic patients. In this chapter, we describe the methods for maintenance and breeding of two diabetic animal models, OVE26 and Agouti mice, for type 1 and type 2 diabetes, respectively. To understand the pathological mechanism, antioxidants such as manganese superoxide dismutase are overexpressed specifically in hearts of diabetic mice. Methods utilized to produce cardiac-targeted transgenic mice are presented in this chapter. Diabetic cardiomyopathy is evaluated in control, diabetic and transgene-protected diabetic animals by measuring contractility of isolated cardiomyocytes. Preparation and contractile analysis of cardiac myocytes are described in detail. Diabetic cardiomyocytes exhibit impaired contractility as well as delayed relaxation, and cardiac-overexpressed antioxidant transgenes are shown to reverse this damage.

Animals↗
PubMed2005

Cardiomyocyte dysfunction in models of type 1 and type 2 diabetes.

Cardiomyopathy is a major cause of mortality for both type 1 and 2 diabetic patients. However, experimental analysis of diabetic cardiomyopathy has focused on type 1 diabetes and there are few reports on cardiomyocyte dysfunction in the widely used type 2 diabetic model, db/db. In the current study, we assessed function in isolated ventricular myocytes from type 1 diabetic OVE26 mice and from type 2 diabetic db/db mice. When compared with their respective control strains, both diabetic models showed significant impairment in contractility, as assessed by percent peak shortening, maximal rate of contraction, and maximal rate of relaxation. The calcium decay rate was also significantly reduced in both types of diabetes, but the decrement was much greater in OVE26 myocytes, approx 50% vs only 20% in db/db myocytes. To understand the basis for slow calcium decay in diabetic myocytes and to understand the molecular basis for the quantitative difference between calcium decay in OVE26 and db/db myocytes, we measured cardiac content of the SERCA2a calcium pump. SERCA2a was significantly decreased in OVE26 diabetic myocytes but not reduced at all in db/db myocytes. The reduction of SERCA2a in OVE26 myocytes was completely prevented by overexpression of the antioxidant protein metallothionein, confirming that oxidative stress is an important component of diabetic cardiomyopathy. The current results demonstrate that though contractility is impaired in individual myocytes of db/db hearts and deficits are similar to what is seen in a severe model of type 1 diabetes, impairment in calcium reuptake is less severe, probably as a result of maintenance of normal levels of SERCA2a.

Animals↗
PubMed2005

Overexpression of hexokinase protects hypoxic and diabetic cardiomyocytes by increasing ATP generation.

Cardiac glucose metabolism is critical to hypoxic cardiac function and hypoxia is known to stimulate glucose metabolism. This increases generation of ATP when mitochondrial respiration is inhibited. In diabetes, cardiac glucose metabolism declines and this may contribute to diabetic cardiomyopathy. The first step in committing glucose to metabolism is glucose phosphorylation catalyzed by hexokinase. But the potential role of hexokinase in the hypoxic or diabetic heart is uncertain. This study is designed to assess the ability of hexo-kinase and elevated ATP to protect cardiomyocyte contractility from hypoxia and diabetes. We used cardiomyocytes from the transgenic mouse Mh, which has cardiac specific expression of yeast hexokinase, to investigate the importance of glucose phosphorylation in the myocyte response to hypoxia and diabetes. Cardiomyocytes were isolated from FVB control and Mh hearts to assess the effects of 2 h of hypoxia on myocyte contractility and ATP content. The protective effect of hexokinase on diabetes was assessed in myocytes from the OVE26 Type I diabetic mouse and in OVE26Mh diabetic mice that carry the hexokinase gene. Overexpression of hexokinase had no effect during aerobic culture, but during hypoxia, hexokinase improved ATP content by 44% and this restored contractility almost to normal levels. In myocytes from diabetic mice, tested under both aerobic and hypoxic conditions, the hexokinase gene significantly improved ATP content and this significantly improved contractility. These results demonstrate that elevating hexokinase activity can be beneficial to hypoxic or diabetic cardiomyocytes secondary to improving myocyte ATP levels.

Adenosine Triphosphate↗
PubMed2004

Cardiac expression of kinase-deficient 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase inhibits glycolysis, promotes hypertrophy, impairs myocyte function, and reduces insulin sensitivity.

Glycolysis is important to cardiac metabolism and reduced glycolysis may contribute to diabetic cardiomyopathy. To understand its role independent of diabetes or hypoxic injury, we modulated glycolysis by cardiac-specific overexpression of kinase-deficient 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase (kd-PFK-2). PFK-2 controls the level of fructose 2,6-bisphosphate (Fru-2,6-P(2)), an important regulator of glycolysis. Transgenic mice had over 2-fold reduced levels of Fru-2,6-P(2). Heart weight/body weight ratio indicated mild hypertrophy. Sirius red staining for collagen was significantly increased. We observed a 2-fold elevation in glucose 6-phosphate and fructose 6-phosphate levels, whereas fructose 1,6-bisphosphate was reduced 2-fold. Pathways branching off of glycolysis above phosphofructokinase were activated as indicated by over 2-fold elevated UDP-N-acetylglucosamine and glycogen. The kd-PFK-2 transgene significantly inhibited glycolysis in perfused hearts. Insulin stimulation of metabolism and Akt phosphorylation were sharply reduced. In addition, contractility of isolated cardiomyocytes was impaired during basal and hypoxic incubations. The present study shows that cardiac overexpression of kinase-deficient PFK-2 reduces cardiac glycolysis that produced negative consequences to the heart including hypertrophy, fibrosis, and reduced cardiomyocyte function. In addition, metabolic and signaling responses to insulin were significantly decreased.

Animals↗
PubMed2004

Catalase protects cardiomyocyte function in models of type 1 and type 2 diabetes.

Many diabetic patients suffer from a cardiomyopathy that cannot be explained by poor coronary perfusion. Reactive oxygen species (ROS) have been proposed to contribute to this cardiomyopathy. Consistent with this we found evidence for induction of the antioxidant genes for catalase in diabetic OVE26 hearts. To determine whether increased antioxidant protection could reduce diabetic cardiomyopathy, we assessed cardiac morphology and contractility, Ca(2+) handling, malondialdehyde (MDA)-modified proteins, and ROS levels in individual cardiomyocytes isolated from control hearts, OVE26 diabetic hearts, and diabetic hearts overexpressing the antioxidant protein catalase. Diabetic hearts showed damaged mitochondria and myofibrils, reduced myocyte contractility, slowed intracellular Ca(2+) decay, and increased MDA-modified proteins compared with control myocytes. Overexpressing catalase preserved normal cardiac morphology, prevented the contractile defects, and reduced MDA protein modification but did not reverse the slowed Ca(2+) decay induced by diabetes. Additionally, high glucose promoted significantly increased generation of ROS in diabetic cardiomyocytes. Chronic overexpression of catalase or acute in vitro treatment with rotenone, an inhibitor of mitochondrial complex I, or thenoyltrifluoroacetone, an inhibitor of mitochondrial complex II, eliminated excess ROS production in diabetic cardiomyocytes. The structural damage to diabetic mitochondria and the efficacy of mitochondrial inhibitors in reducing ROS suggest that mitochondria are a source of oxidative damage in diabetic cardiomyocytes. We also found that catalase overexpression protected cardiomyocyte contractility in the agouti model of type 2 diabetes. These data show that both type 1 and type 2 diabetes induce damage at the level of individual myocytes, and that this damage occurs through mechanisms utilizing ROS.

Animals↗
PubMed2003

Influence of gender on ethanol-induced ventricular myocyte contractile depression in transgenic mice with cardiac overexpression of alcohol dehydrogenase.

Acute ethanol exposure depresses ventricular contractility and contributes to alcoholic cardiomyopathy in both men and women chronically consuming ethanol. However, a gender-related difference in the severity of myopathy exists with female being more sensitive to ethanol-induced tissue damage. Acetaldehyde (ACA), the major oxidized product of ethanol, has been implicated to play a role in the pathogenesis and gender-related difference of alcoholic cardiomyopathy, possibly due to its direct cardiac effect and interaction with estrogen. This study was designed to compare the effects of cardiac overexpression of alcohol dehydrogenase (ADH), which converts ethanol into ACA, on the cardiac contractile response to ethanol in ventricular myocytes isolated from age-matched adult male and female transgenic (ADH) and wild-type (FVB) mice. Mechanical properties were measured with an IonOptix SoftEdge system. ACA production was assessed by gas chromatography. The ADH myocytes from both genders exhibited similar mechanical properties but a higher efficacy to produce ACA compared to FVB myocytes. Exposure to ethanol (80-640 mg/dl) for 60 min elicited concentration-dependent decrease of cell shortening in both FVB and ADH groups. The ethanol-induced depression on cell shortening was significantly augmented in female but not male ADH group. ADH transgene did not exacerbate the ethanol-induced inhibition of maximal velocity of shortening/relengthening in either gender. In addition, neither ethanol nor ADH transgene affect the duration of shortening and relengthening in male or female mice. These data suggest that females may be more sensitive to ACA-induced cardiac contractile depression than male, which may attribute to the gender-related difference of alcoholic cardiomyopathy.

Age Factors↗
PubMed2003

Successful orthotopic liver transplantation after trimethoprim-sulfamethoxazole associated fulminant liver failure.

Trimethoprim-sulfamethoxazole (TMP-SMZ) is one of the most commonly used antibiotics. Although many of its adverse effects are well recognized, TMP-SMZ related hepatotoxicity is considered rare and is usually characterized by cholestasis or mixed hepatocellular-holestatic reactions. In this study, we describe the case of a previously healthy young man with acute fulminant liver failure caused by TMP-SMZ. The patient presented with complaints of 'flu-like' symptoms with myalgia and fever after taking TMP-SMZ for 7 d for otitis externa. The patient subsequently developed fever, worsening jaundice, and a rash on his neck and chest. Liver enzymes peaked on day 3 with alanine aminotransferase (ALT) 11,549, aspartate aminotransferase (AST) 23,289, alkaline phosphatase 245, and total bilirubin 10.3 mg/dL, with a conjugated bilirubin of 8.3 mg/dL, prothrombin time (PT) 60.5 s, partial normalized ratio (PTT) 49 s, and international normalized ratio (INR) 7.5. Of note, acetaminophen level on admission was undetectable. Serology for hepatitis A, B, C, cytomegalovirus, HIV, toxoplasmosis, and blood cultures were all negative. The patient developed hepatic encephalopathy with hallucination on day 4. Laboratory tests revealed a serum ammonia level of 190 U, serum creatinine kinase (CK) 10,466 (42 on admission), serum creatinine 8.2 mg/dL (1.2 on admission), and significant metabolic acidosis. Renal ultrasound was unremarkable. The patient was started on hemodialysis for acute renal failure. Meanwhile, liver transplantation assessment was also initiated. On day 8 post-admission (15 d after taking TMP-SMZ), the patient received a successful orthotopic liver transplant.

Adult↗
PubMed2003

Influence of gender on intrinsic contractile properties of isolated ventricular myocytes from calmodulin-induced diabetic transgenic mice.

Diabetes mellitus impairs ventricular function, which itself may be disparately influenced by gender. This study compared the impact of gender on cardiac contractile response in ventricular myocytes from wild-type FVB and calmodulin-induced diabetic transgenic (OVE26) mice at young (2 month) and older (11 month) age. Mechanical and intracellular Ca2+ properties of cardiac myocytes were evaluated using an IonOptix MyoCam system. Diabetic mice of both genders exhibited significantly elevated blood glucose regardless of age. OVE26 myocytes displayed reduced peak shortening (PS) and maximal velocity of shortening/relengthening (+/- dL/dt), and prolonged time-to-PS (TPS) and time-to-90% relengthening (TR90), associated with higher resting intracellular Ca2+ levels and attenuated Ca(2+)-induced intracellular Ca2+ release compared with the FVB myocytes. Peak shortening and +/- dL/dt were smaller in female FVB groups when compared to the age-matched male counterparts. However, these gender differences were ablated by the diabetic state. No significant gender-related differences in intracellular Ca2+ handling were noted in either FVB or OVE26 myocytes, with the exception of overt gender differences in OVE26 mice when age was taken into account. Young female OVE26 mice exhibited better-preserved mechanical function while older female OVE26 mice displayed the worst mechanical function among all four OVE26 groups. In conclusion, our data confirmed impaired cardiac contractile function in diabetes, partially due to altered intracellular Ca2+ handling, in both genders. Mechanical differences existed between genders but were "cancelled off" by diabetic state. Nevertheless, a "female advantage" in ventricular function may still persist in young female diabetic subjects.

Age Factors↗