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Biomedical subjects

Y Yu

Publications and source records attributed to Y Yu.

At least 289 records · Page 16Linked to original sources
PubMed1999

[Biopterin synthesis and GTP cyclohydrolase I mRNA expression in rats following endotoxic shock].

OBJECTIVE: To investigate the potential role of changes in biopterin (tetrahydrobiopterin and more oxidized species) synthesis and GTP cyclohydrolase I (GTP-CHI) mRNA expression in endotoxic shock. METHODS: SD rats were subjected to endotoxic shock by a bolus injection of lipopolysaccharide (15 mg/kg, i.p.), biopterin and GTP-CHI mRNA levels in liver, kidney, and intestine were determined at 4, 8 hours following endotoxin challenge. RESULTS: Tissue biopterin levels significantly elevated in liver, kidney, and intestine, with high levels sustaining for 8 hours after endotoxin challenge (P < 0.05, P < 0.01). Similarly, GTP-CHI mRNA induction in various tissues substantially increased within 4 hours compared to normal controls (P < 0.05, P < 0.01). It was also shown that hepatic and renal biopterin levels were positively correlated with glutamic pyruvic transaminase (GPT) and also blood urea nitrogen (BUN) values (both P < 0.01). In addition, treatment with recombinant bactericidal/permeability increasing protein (rBPI(21)) markedly reduced tissue biopterin and GTP-CHI mRNA levels, concomitant with significant decreases in GPT, BUN as well as D-lactate values. CONCLUSIONS: Biopterin synthesis and release may be involved in the development of endotoxin-induced multiple organ dysfunction, and early use of rBPI(21) is effective to inhibit marked GTP-CHI mRNA expression and biopterin formation following septic shock.

Animals↗
PubMed1999

[Gene expression of lipopolysaccharide receptor CD14 and tumor necrosis factor-alpha in rats after thermal injury].

OBJECTIVE: To investigate changes in lipopolysaccharide receptor CD14 and tumor necrosis factor-alpha (TNF-alpha) gene expression in vital organs, and their significance in the pathogenesis of systemic inflammation after burns. METHODS: Wistar rats were subjected to a 35 percent full-thickness scald injury, then sacrificed pre-burn, and postburn 12, 24, 48, 72 hours, respectively. Tissue samples from liver, kidney, lung and intestine were collected to measure CD14 and TNF-alpha mRNA expression. Peritoneal macrophages were harvested by peritoneal lavage to determine CD14 mRNA expression. RESULTS: CD14 mRNA expression increased markedly after thermal injury, peaking at both 12 and 48 hours. Likewise, CD14 mRNA levels were significantly up-regulated in peritoneal macrophages. Gene expression of TNF-alpha elevated markedly in liver, lungs, and kidneys after acute insults. Positive correlation was found between CD14 mRNA and TNF-alpha mRNA in liver, lung, and kidney tissues. CONCLUSIONS: Thermal injury per se can markedly up-regulate both CD14 and TNF-alpha gene expression in various organs. Excessive CD14 mRNA expression may enhance synthesis and release of TNF-alpha stimulated by endotoxin translocation, and the interaction between CD14 and TNF-alpha may play an important role in mediating multiple organ damage secondary to major burns.

Animals↗
PubMed1999

[Preoperative arterial infusion chemotherapy of colorectal carcinoma pathological and clinical effects].

OBJECTIVE: To investigate the pathological and clinical effects of preoperative selective intra-arterial infusion chemotherapy on colorectal carcinoma. METHODS: 30 patients with colorectal carcinoma underwent selective regional arterial angiography by Seldinger's method followed by intra-arterial infusion chemotherapy. RESULTS: changes of karyopyknosis, karyorrhexis, coagulation and necrosis of cytoplasm in cancer cells around vascular vessels were found in all cases. Interstitial edema, invasion of inflammatory cells, fibroelastosis around cancer cells, proliferous intima, thrombus and inflammation of vessels were also found at the same sites. CONCLUSIONS: Histological changes are significant after preoperative selective intra-arterial infusion chemotherapy for colorectal carcinoma. This therapy can relieve symptoms.

Adult↗
PubMed1999

[Surgical treatment of truncus arteriosus in children].

OBJECTIVE: To summarize the surgical results of truncus arteriosus in children. METHODS: Five patients with persistent truncus arteriosus underwent complete repair of truncus arteriosus. Type I was found in 2 patients, type II in 2 and type IV in 1 according to Collett and Edwards. Their ages ranged from 3 to 12 years (mean 6.3 years). The time of pulmonary circulation and evacuation of the pulmonary artery was not significantly prolonged. Complete repair was via a median sternotomy utilizing hypothemia with cardiopulmonary bypass, entailing separation of the pulmonary arteries from the truncus, repair of the resultant defect in the aorta, ventricular septal defect (VSD) closure with a patch in which the interrupted pledget-supported suture was placed in the truncal valve annulus of the superior border of VSD, and restoration of right ventricular outflow tract (RVOT) continuity utilizing extra cardiac conduits, of which autologous pericardial valved dacron conduit was used in 4 patients and homograft conduit in 1. RESULTS: Postoperative mean pulmonary pressure decreased significantly in all patients (P < 0.01) and the pressure gradient across conduit was 7 - 35 mm Hg. Two patients died immediately after the operation, which was not associated with pulmonary vascular lesion. Among 3 survivors, I had low cardiac output and respiratory dysfunction after operation and the others recuperated uneventfully. Survivors were followed up for a period of 114, 96 and 34 months respectively, and were all in NYHA functional class I. One died of occlusion of conduit 8 years after operation. CONCLUSIONS: Children with truncus arteriosus are still indicated for complete correction. Autologous pericardial valved dacron conduit has excellent long-term outcomes. Correcting truncal valve insufficiency, repairing VSD, avoiding large pressure gradient across conduit and shortening CPB time are keys to improve the survival rate of patients and achieve excellent long-term outcome.

Bioprosthesis↗
PubMed1999

[Fisher discriminant analysis for carcinogenic potency of aromatic amines].

OBJECTIVE: To study the relationship between carcinogenicity and their structure and physicochemical parameters of aromatic amines. METHODS: Fisher discriminant analysis for carcinogenicity of aromatic amines in two different batches was conducted with estimation of parameters of physicochemical using central atom and functional groups in combination with structural parameters of polycyclic aromatic hydrocarbons (PAHs). RESULTS: The discriminant efficacy approximated to that of the two in a series of equations (I and III) established by Yuta, but inferior to the optimal equation II. CONCLUSION: The selected physicochemical parameters can be applied to QSAR study on carcinogenicity of most aromatic amines, with better results in Fisher discriminant analysis.

Amines↗
PubMed1999

[A study on immunogenicity and safety of bivalent inactivated vaccine against hemorrhagic fever with renal syndrome].

OBJECTIVE: To study side effects and effectiveness of bivalent inactivated vaccine against hemorrhagic fever with renal syndrome in population of a randomized controlled field trial. METHODS: Serum indirect immunofluorescent antibody in 167 persons and neutralization antibody (types I and II) in 69 persons, who received three-dose vaccine, were determined two weeks after immunization, and side effects in 657 vaccinees were observed within 72 houses after immunization. RESULTS: Serum positive conversion rate of indirect immunofluorescent antibody was 99.04% (166/167) with GMT of 24.51 +/- 2.06. Serum positive conversion rate of neutralization antibody was 100% (69/69), 91.30% (63/69) for types I and 88.41% (61/69) for type II, respectively. GMTs for type I and II neutralization antibody were 18.27 +/- 2.21 and 12.47 +/- 2.16, respectively. Side effects at local site vaccinated of the body and temperature rising could be seen in 1.48% and 0.36% of the vaccinees, respectively. No severe side effect and abnormal reaction was found in vaccinees on the field. CONCLUSION: Immune response to bivalent inactivated vaccine against hemorrhagic fever with renal syndrome was satisfactory with slight side effect.

Adolescent↗
PubMed1999

[A computer-aided analysis system for hypertensive retinal image and its clinical application].

With the use of computer image processing technology and microcirculational network analysis technology, we have developed a new system to analyze the outlook of retinal vessles quantitatively. A multimedia structure has been designed for patient's case history file, which includes the basic information of patients, the operating information during sampling and processing patient's retinal image and the result. The system includes image sampling, image displaying, image processing, parameters measuring and analyzing, reports printing and atlas management. Clinical application indicates that the system is useful to hypertension diagnosis.

Aged↗
PubMed1999

[A robust method for automated detection and grading of retinal venous beading in diabetes mellitus].

Diabetes mellitus is a high prevalence disease in the world and retinal vessel changes such as venous beading are common findings in patients suffering from long-standing diabetes. Three methods (1. Combined use of the SED, ROSE, Modified LoG algorithm; 2. Gaussian fitting-based method; 3. Gradient-based method) for detection venous caliber were used in the first processing stage, then the magnitude of fast Fourier transform of variation function of venous caliber was used as a detective index of venous beading. The reliability of the results, justified by their low variability, makes feasible the standardization of quantitative parameters to be used both in the diagnosis and in the prognosis of diabetes, and also allows prospective studies based upon them.

Algorithms↗
PubMed1999

[Effects of IFN-gamma gene-modified hepatocytes on TGF-beta 1 and its receptor in mice infected with Schistosoma japonicum].

AIM: To explore the anti-schistosomal hepatic fibrosis effect and the changes in transforming growth factor-beta 1 (TGF-beta 1) and its receptors (TGF-beta RII) in S. japonicum infected mice after intrasplenic transplantation of gamma-interferon (IFN-gamma) gene-modified hepatocytes. METHODS: At 16 wk after infection with cercariae of Schistosoma japonicum, the mice were intrasplenically transplantated with murine hepatocytes which had been transfected with IFN-gamma gene-combinant adenovirus vector. ELISA, immunohistochemical and dot blot techniques were used to observe the dynamic changes in IFN-gamma, TGF-beta 1, TGF-beta RII and type I, III collagen. RESULTS: The intrasplenic transplantation of IFN-gamma gene modified hepatocytes effectively expressed IFN-gamma and obviously reduced the production and deposition of type I, III collagen as well as TGF-beta 1 and TGF-beta RII. CONCLUSION: IFN-gamma gene transplantation has anti-hepatic fibrosis efficacy in Schistosoma japonicum-infected mice, being related to its role of decreasing the expression of TGF-beta 1 and TGF-beta RII.

Animals↗
PubMed1999

[Immunocytochemical localization of two facilitated glucose transporters of Schistosoma mansoni in the tegument of Schistosoma japonicum].

AIM: To observe the distribution of Schistosoma mansoni glucose transport proteins, SGTP1 and SGTP4, in the tegument of Schistosoma japonicum. METHODS: The rapidly frozen fixation technique and ultracryomicrotomy were adopted for preparing ultrathin cryosections of S. japonicum. Anti-SGTP1 and anti-SGTP4 antibodies were used to localize the corresponding antigens in the tegument of adult S. japonicum by immunocytochemical technique. RESULTS: SGTP1 was localized on the basal membrane of the tegument and its infoldings, SGTP4 was localized on the apical membrane of the tegument and its invaginations of S. japonicum. CONCLUSION: The same localization for SGTP 1 and SGTP4 in the tegument of S. japonicum and S. mansoni exhibited apparent homology between SGTPs of the two schistosomes.

Animals↗
PubMed1999

[Identification of Panax quinquefolius, P. ginseng and P. notoginseng by protein fingerprints].

Establish the way of protein fingerprints to identify P. quinquefolius, P. ginseng and P. notoginseng of genus Panax by SDS-PAGE, Tris-tricine and Western blot. The fingerprints of Panax species from 28 KD to 58 KD and 55 KD are in common. Very different fingerprints of P. quinquefolius are found below 28 KD. The fingerprints above 58 KD seemed to be peculiar for P. ginseng. Hence the approach may be used as a means to authenticate the concerned Panax species, especially for identification of P. quinquefolius.

Blotting, Western↗
PubMed1999

[Studies on treacheostomal formation and voice prosthesis after total laryngectomy].

OBJECTIVE: To establish a tracheostomy model with no stricture and "bowl-shaped" collapse. METHODS: Twenty-five cases were reconstructed with Blom-Singer technique after total laryngectomy for tracheoesophageal voice in our department since 1996. Tracheostoma was done with 5 kinds of methods. In 6 cases, anterior cervical U-shaped incision + division of sternal attachments of bilateral sternomastoid muscles + Griffith tracheostoma enlargement (combination method) were used in the primary operation, and the third generation of indwelling prosthesis and tracheostomal valve were installed. RESULTS: In these 25 cases, 23 could speak freely. The successful rate was 92%. In tracheostoma operation, there were 7 cases with their skin sutured directly to tracheal rings, 3 cases with Myers method, 6 cases with Griffith method, 3 cases with [symbol: see text] method. All of them needed cannulation for more than 6 months and had stricture of tracheostoma and "bowl-shaped" collapse of various degrees. But those underwent "combination method" needed no cannulation and no stricture and bowlshaped collapse was found during 6 mouths' follow-up. CONCLUSION: The combination method of tracheostomy makes the installation, postoperative care and replacement of prosthesis and tracheostomal valve easy and the indwelling prosthesis has the best tone quality. The use of tracheostomal valve effectively makes the patient's hand free during speaking.

Follow-Up Studies↗
PubMed1999

[Research into simultaneous determination of five components by ridge regression spectrophotometry].

Ridge regression spectrophotometry (LHG) is one of the computational spectrophotometry developed recently. It is used in this paper to the analysis of five component s--acetaminophen, p -aminophenol. p -nitrophenol. p -acetaminophenol acetic acid ester and p -nitrophenol acetic acid ester. The choose of medium and the determination of the amount of mixed standard solution were described in detail. The experimental results show that in the medium of 0.1 mol x L(-1) HCI, the recovery ratio of each component ranges from 95.5% to 106.1% and the RSD ranges from 0.8% to 9.8%. This approach is simple and suitable for the computer-aid analysis. The approach has been used to the analysis of the sample in the course of synthetic acetaminophen.

English Abstract↗
PubMed1999

[Research into determination of tricomponent sample by ridge regression spectrophotometry].

In this paper ridge regression spectrophotometry was used to analyze three components--Acetaminophen, P-Ni-trophenol and P-Aminophenol with absolute ethanol as the solvent. The basic principle and analytical steps of the method were described in detail. The experimental results show that the recovery of each component ranges from 99.24% to 101.31% with the medium of absolute ethanol. As compared with conventional methods, this method is simple, rapid and suitable for computer-aid analysis.

Acetaminophen↗
PubMed1998

Lymphotactin gene-modified bone marrow dendritic cells act as more potent adjuvants for peptide delivery to induce specific antitumor immunity.

Dendritic cells (DC) are regarded as attractive candidates for cancer immunotherapy. Our aim is to improve the therapeutic efficacy of DC-based tumor vaccine by augmenting DC preferential chemotaxis on T cells. Mouse bone marrow-derived DC were transduced with lymphotactin (Lptn) gene by adenovirus vector. The supernatants from Lptn gene-modified DC (Lptn-DC) were capable of attracting CD4+ and CD8+ T cells in a chemotaxis assay, whereas their mock control could not. Lptn expression of Lptn-DC was further confirmed by RT-PCR. Lptn-DC were pulsed with Mut1 peptide and used for vaccination. Immunization with the low dose (1 x 10(4)) of Mut1 peptide-pulsed DC induced weak CTL activity, whereas the same amounts of Mut1 peptide-pulsed Lptn-DC markedly induced specific CTL against 3LL tumor cells. A single immunization with 1 x 10(4) Mut1 peptide-pulsed Lptn-DC could render mice resistant to a 5 x 10(5) 3LL tumor cell challenge completely, but their counterpart could not. The protective immunity induced by Mut1 peptide-pulsed Lptn-DC depends on both CD4+ T cells and CD8+ T cells rather than NK cells in the induction phase and depends on CD8+ T cells rather than CD4+ T cells and NK cells in the effector phase. Moreover, the involvement of CD28/CTLA4 costimulation pathway and IFN-gamma are also necessary. When 3LL tumor-bearing mice were treated with 1 x 10(4) Mut1 peptide-pulsed Lptn-DC, their pulmonary metastases were significantly reduced, whereas the same low dose of Mut1 peptide-pulsed DC had no obvious therapeutic effects. Our data suggest that Lptn-DC are more potent adjuvants for peptide delivery to induce protective and therapeutic antitumor immunity.

Adenoviridae↗
PubMed1998

Evidence of oxidative stress in mdx mouse muscle: studies of the pre-necrotic state.

Considerable evidence indicates that free radical injury may underlie the pathologic changes in muscular dystrophies from mammalian and avian species. We have investigated the role of oxidative injury in muscle necrosis in mice with a muscular dystrophy due to a defect in the dystrophin gene (the mdx strain). In order to avoid secondary consequences of muscle necrosis, all experiments were done on muscle prior to the onset of the degenerative process (i.e. during the 'pre-necrotic' phase) which lasted up to 20 days of age in the muscles examined. In pre-necrotic mdx muscle, there was an induction of expression of genes encoding antioxidant enzymes, indicative of a cellular response to oxidative stress. In addition, the levels of lipid peroxidation were greater in mdx muscle than in the control. Since the free radical nitric oxide (NO*) has been shown to mediate oxidative injury in various disease states, and because dystrophin has been shown to form a complex with the enzyme nitric oxide synthase, we examined pre-necrotic mdx muscle for evidence of NO*-mediated injury by measuring cellular nitrotyrosine formation. By both immunohistochemical and electrochemical analyses, no evidence of increased nitrotyrosine levels in mdx muscle was detected. Therefore, although no relationship with NO*-mediated toxicity was found, we found evidence of increased oxidative stress preceding the onset of muscle cell death in dystrophin-deficient mice. These results lend support to the hypothesis that free radical-mediated injury may contribute to the pathogenesis of muscular dystrophies.

Animals↗