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Biomedical subjects

J Cheng

Publications and source records attributed to J Cheng.

At least 127 records · Page 7Linked to original sources
PubMed2000

Naltrexone: effects on motor function, speech, and activities of daily living in a patient with traumatic brain injury.

Evidence from many studies has suggested that endogenous opioid peptides participate in a number of pathophysiological responses to brain injury. This provides the rationale for the use of opioid antagonists for the enhancement of neural recovery after brain injury. A case is presented of an 18-year-old male who had loss of consciousness for 1 month after a severe brain injury. Three months of intensive rehabilitative therapies did not change his functional status. A trial of naltrexone was given while his performance in mobility, speech and overall Functional Independence Measure (FIM) scores were monitored. Results indicate an accelerated improvement in functional status and statistically improved FIM score.

Activities of Daily Living↗
PubMed2000

Prediction of the effect of enzymes on chick performance when added to cereal-based diets: use of a modified log-linear model.

A previous study demonstrated that a log equation could be used to predict the relationship between the amount of a crude enzyme added to a diet and chick performance. The objective of the current study was to determine if a modification of the original equation, in conjunction with a computer program, would overcome some of its limitations. The modified equation was Y = A + B log (CX + 1), where Y is the estimated performance value; A is the intercept that represents the performance without enzyme supplementation; B, the slope of the equation (performance change per log unit of an enzyme in the diet), is a measure of an enzyme efficacy; C is an amplified factor; and X is the amount of enzyme in the diet. The results demonstrated that the new model more accurately predicted chick performance than that of the original equation with correlations (r) between chick performance and amount of different enzymes added to the diet ranging from r = 0.80 to 0.99 (P < 0.05). In addition, the same trends were found when the model was used to assess the efficacy of a given enzyme added to corn-, wheat-, barley-, and rye-based diets or for combinations of two dietary components (rye and wheat). The model proposed in this study provides a new means of assessing the overall efficacy of an enzyme preparation. This model could be routinely used by enzyme and livestock producers to establish the best combination of different cereals and enzymes so as to maximize net returns.

6-Phytase↗
PubMed2000

Synergistic interaction of MEK kinase 2, c-Jun N-terminal kinase (JNK) kinase 2, and JNK1 results in efficient and specific JNK1 activation.

Mitogen-activated protein kinases (MAPKs) are activated through cascades or modules consisting of a MAPK, a MAPK kinase (MAPKK), and a MAPKK kinase (MAPKKK). Investigating the molecular basis of activation of the c-Jun N-terminal kinase (JNK) subgroup of MAPK by the MAPKKK MEKK2, we found that strong and specific JNK1 activation by MEKK2 was mediated by the MAPKK JNK kinase 2 (JNKK2) rather than by JNKK1 through formation of a tripartite complex consisting of MEKK2, JNKK2, and JNK1. No scaffold protein was required for the MEKK2-JNKK2-JNK1 tripartite-complex formation. Expression of JNK1, JNKK2, and MEKK2 significantly augmented the coprecipitation of, respectively, MEKK2-JNKK2, MEKK2-JNK1, and JNKK2-JNK1, indicating that the interaction of MEKK2, JNKK2, and JNK1 is synergistic. Finally, the JNK1 was activated more efficiently in the MEKK2-JNKK2-JNK1 complex than was the JNK1 excluded from the complex. Thus, formation of a signaling complex through synergistic interaction of a MAPKKK, a MAPKK, and a MAPK molecule like MEKK2-JNKK2-JNK1 is likely to be responsible for the efficient, specific flow of information via MAPK cascades.

Animals↗
PubMed2000

Causation of Crohn's disease by Mycobacterium avium subspecies paratuberculosis.

Mycobacterium avium subspecies paratuberculosis (MAP) is a member of the M avium complex (MAC). It differs genetically from other MAC in having 14 to 18 copies of IS900 and a single cassette of DNA involved in the biosynthesis of surface carbohydrate. Unlike other MAC, MAP is a specific cause of chronic inflammation of the intestine in many animal species, including primates. The disease ranges from pluribacillary to paucimicrobial, with chronic granulomatous inflammation like leprosy in humans. MAP infection can persist for years without causing clinical disease. The herd prevalence of MAP infection in Western Europe and North America is reported in the range 21% to 54%. These subclinically infected animals shed MAP in their milk and onto pastures. MAP is more robust than tuberculosis, and the risk that is conveyed to human populations in retail milk and in domestic water supplies is high. MAP is harboured in the ileocolonic mucosa of a proportion of normal people and can be detected in a high proportion of full thickness samples of inflamed Crohn's disease gut by improved culture systems and IS900 polymerase chain reaction if the correct methods are used. MAP in Crohn's disease is present in a protease-resistant nonbacillary form, can evade immune recognition and probably causes an immune dysregulation. As with other MAC, MAP is resistant to most standard antituberculous drugs. Treatment of Crohn's disease with combinations of drugs more active against MAC such as rifabutin and clarithromycin can bring about a profound improvement and, in a few cases, apparent disease eradication. New drugs as well as effective MAP vaccines for animals and humans are needed. The problems caused by MAP constitute a public health issue of tragic proportions for which a range of remedial measures are urgently needed.

Animals↗
PubMed2000

[Cloning and sequence analysis of human genomic DNA of augmenter of liver regeneration hepatitis].

OBJECTIVE: To clone the human genomic DNA of augmenter of liver regeneration (ALR) and specify the intron-exon structure. METHODS: Using human ALR cDNA sequence as a reference and BLAST path as a nucleotide homology search tool, GenBank has been searched for ALR homologous genomic DNA sequence. The intron-exon sequences were defined by the Breathnath-Chambon rule. RESULTS: The coding sequence of human ALR consists of 3 exons, and is similar to murine ALR genomic DNA structure. The human ALR genomic DNA is 1813 nt long and codes a protein of 125 amino acid residues. CONCLUSION: Human genomic DNA of ALR consists of 3 exons and 2 introns.

Base Sequence↗
PubMed2000

Expression of human single-chain variable fragment antibody against non-structural protein 3 of hepatitis C virus antigen in e.coli.

OBJECTIVE: To express human single-chain variable fragment (ScFv) antibody against non-structural protein 3 (NS(3)) of hepatitis C virus in E.coli. METHODS: The recombinant phages were panned by NS(3) antigen which was coated in a microtiter plate. After five rounds of biopanning, 66 clones were identified specific to NS(3) antigen. E.coli host XL(1)-Blue was transformed and induced by IPTG. The specificity of ScFv was evaluated by ELISA and dot blot hybridization. RESULTS: ScFv-NS(3) DNA digestion and sequencing data showed that the ScFv gene was composed of 750bp. ELISA and dot blot hybridization demonstrated that the soluble human single-chain Fv antibody to hepatitis C virus NS(3) antigen could combine different origins of NS(3) antigen. CONCLUSION: NS(3)-ScFv antibody expressed by E.coli host XL(1)-Blue has the activity and specificity to combine different origins of HCV NS(3) antigen.

Escherichia coli↗
PubMed2000

[Analysis of impulse response of rectangular ultrasound transducer].

A new expression for calculating the impulse response of rectangular pistonlike transducers, proper to any points of acoustic field, is presented. The radiated field of ultrasound transducer can be analyzed using impulse response method, avoiding paraxial and farfield approximation. The velocity potential at an observation point is expressed as the convolution of the excitation velocity and the impulse response. A time-amplitude shift method for the far field impulse response of small aperture transducers is presented. The radiated field of rectangular transducers is calculated through the new method and the previous method and excellent agreement is observed.

Algorithms↗
PubMed2000

Two cases of combined liver-kidney transplantation.

OBJECTIVES: To report the clinical experiences of simultaneous hepatorenal transplantation. METHODS: We performed simultaneous hepatorenal transplantation in one patient with liver cirrhosis of hepatitis B and uremia of chronic nephritis on February 1, 1999 and one patient with liver cirrhosis of hepatitis B complicated by hepatorenal syndrome on March 12, 1999. The donors were heart arrest cases. Rapid multiple organ harvesting techniques and UW solution infusion in situ were used. Liver and kidney transplantation were orthotopic and ordinary methods, respectively. Immunosuppressive drugs consisted of cyclosporine, Cellcept, ALG and cortstco steroids. Lamividine was used on day 50 and day 40 postoperation, respectively. RESULTS: Both transplanted organs rapidly achieved normal function postoperation and the patients recovered well but suffered mild kidney rejection day 110 postoperation in No 1 patient. In No 2 patient, acute renal function failure, mental symptoms, muscle spasm, cerebral artery thrombosis, inhalation pneumonia and chronic liver graft rejection ensured sequentially but were controlled. The patients have survived for more than nine and eight months, respectively, with normal life quality. CONCLUSIONS: Combined hepatorenal transplant is a radical treatment method for liver and kidney function failure and requires more comprehensive techniques than isolated single organ transplantation. Preventing the recurrence of hepatitis B by oral lamividine may be a key to long-term survival.

Adult↗
PubMed2000

[Persistence of hepatitis C virus type II in patient's peripheral blood B lymphocytes transformed by Epstein-Barr virus].

OBJECTIVE: To study the persistence and replication of hepatitis C virus (HCV)-RNA in human peripheral blood B cells transformed by Epstein-Barr virus (EBV) and cultured in vitro. METHODS: EBV was used for infecting B lymphocytes from one hepatitis C patient with HCV positive in the peripheral blood mononuclear cells (PBMC) and transforming them into lymphoblasts capable of being propagated indefinitely. Then, HCV RNA of the cultured cells and supernatants was detected by reverse transcriptase-polymerase chain reaction (RT-PCR) every one month. HCV gene was typed by enzyme separating method. Electron microscopy and immunoelectron microscopy were employed to locate HCV in the cells and observe the character of its configuration. RESULTS: HCV positive-strand RNA was detected in the cultured cells for 1 year. Interestingly, the HCV positive-strand RNA was identified in supernatants and the negative-strand RNA was also observed in the cultured cells intermittently. HCV gene was type II. Electron microscopy observed HCV spherical virus-like particles with a diameter of approximately 45 nm to 70 nm, individual particles 110 nm, in the LCL cytoplasmic vesicles. CONCLUSION: HCV may exist in the cultured cell line for a longer period and reproduce in and secrete out of them. HCV locates mainly in the cytoplasm. The cell line might be useful in analyzing the mechanisms of HCV persistence in PBMC.

5' Untranslated Regions↗
PubMed2000

[Construction of a hepatoma-targeting vector of adeno-associated virus containing human alpha-fetoprotein promoter and wild p53 gene in gene therapy of liver cancer].

OBJECTIVE: To construct plasmids that express target genes in hepatoma cell line using adeno-associated virus (AAV) vectors containing human AFP promoter. METHODS: Primers containing specific enzyme-cutting sites were designed to amplify the alpha-fetoprotein promoter (AFP promoter) from human genome. The promoter was cloned into pTR-UF5, a plasmid containing GFP reporter gene, resulting in the recombinant AAV plasmid containing the reporter gene (rAAV-AFP-GFP). Blunted ligation was used to construct the recombinant AAV vector plasmid containing human wild p53 gene (rAAV-AFP-53). The plasmid rAAV-AFP-GFP was used to transfect the AFP-expressing Hep G(2) and non-AFP-expressing 293 cell lines, respectively, to measure the function of the cloned AFP promoter. Flow cytometry was used to measure the effect of rAAV-AFP-53 on hepatoma cell line HLE. RESULTS: rAAV-AFP-53 and rAAV-AFP-GFP were verified by DNA sequencing and enzyme digestion to carry human AFP promoter. Cell transfection of rAAV-AFP-GFP showed selective expression in AFP-positive hepatoma cell lines with a transfection rate of 36.5%; rAAV-AFP-53 induced apoptosis rate was 73.88%. CONCLUSION: Two adeno-associated virus plasmids are successfully constructed that carry p53 gene and reporter gene, respectively, guided by AFP promoter. The former one shows a hepatoma-specific apoptosis-inducing effect.

Apoptosis↗
PubMed2000

[Melanoma antigen-3 expression in human hepatocellular carcinoma].

OBJECTIVE: To investigate the expression of melanoma antigen-3 (MAGE-3) mRNA in human hepatocellular carcinoma (HCC) and probe into the theoretical feasibility that MAGE-3 antigens can be developed as a new peptide vaccine for immunotherapy in HCC patients. METHODS: The expression of MAGE-3 mRNA in HCC tissues and the adjacent non-HCC liver tissues was studied using RT-PCR in 45 HCC patients. The results were compared with those of 16 cirrhotic patients and 12 patients whose liver tissues were pathologically normal. MAGE-3 mRNA positive PCR products were DNA sequenced in 3 HCC patients. The sequenced fragments of MAGE-3 cDNA were used as template by which a [alpha(32)P] labeled probe was synthesized and employed for Southern blot analysis. HLA class I-A and -B typing of 43 HCC patients were assayed by ELISA. RESULTS: Of the 45 HCC samples, 35 (78%) expressed MAGE-3 mRNA and six HCC adjacent tissues were also positive in MAGE-3 expression. Pathological examination showed cellular heteromorphism in these adjacent tissues. The non-HCC liver tissues from cirrhosis and normal liver samples were not MAGE-3 mRNA detectable. The DNA sequence confirmed that the target gene fragment in all of the 3 samples of PCR products was MAGE-3 cDNA. Southern blotting result confirmed that of RT-PCR assay. In HCC patients, the predominant types of HLA were A(2) (53.5%), A(11) (25.6%), A(24) (20.9%), A(33) (20.9%), B(13) (28.3%), and B(35) (23.2%). MAGE-3 mRNA expression in HCC showed no correlation with the level of serum AFP and the size of the tumor. CONCLUSIONS: MAGE-3 mRNA is expressed at a high percentage of HCC samples. This tumor rejection antigen may be used as peptide vaccine for immunotherapy of HCC patients. The phenomena that some non-HCC adjacent tissues with heteromorphism can express MAGE-3 like their paired HCC tissues indicate that the expression of MAGE-3 may be an indicator in the early stage of carcinogenesis of liver tissues.

Aged↗
PubMed2000

[Epidemiological feature on diabetes mellitus among permanent inhabitant in the Special Economic Zone of Shenzhen].

OBJECTIVE: To investigate prevalence and relevant factors of diabetes mellitus among permanent inhabitant in Shenzhen. METHODS: The prevalence of 8 200 inhabitants aged over 20 in Shenzhen was studied. Blood glucose was determined by glucose - oxidase method. RESULTS: According to the WHO diagnostic standard, the prevalence rates of DM and IGT were 4.23% and 11.94% respectively. The prevalence increased apparently with age. The history of clan and overweight were related to the prevalence rates of DM and IGT. The people of DM and IGT were mostly accompanied with high levels of triglyceride, total cholesterol, uric acid, creatinine and low level of high dense lipoprotein (HDL). CONCLUSION: The history of clan, old age, overweight and higher fattiness were found risk factors of DM and IGT.

Adult↗
PubMed2000

[Risk factors of type 2 diabetes in Shenzhen].

OBJECTIVE: The study was designed to investigate the risk factors of Type 2 diabetes in the new city Shenzhen. METHODS: A representative sample of 8,182 adults aged over 20 to 75 years old were randomly selected in the residents of Shenzhen, China in 1997. Type 2 diabetes was diagnosed according to the WHO criteria. Questionnaire survey, anthropometric measurement and blood analysis were carried out, and logistic regression analysis was used to study the risk factors. RESULTS: The results showed that the prevalence of type 2 diabetes in subjects with high total cholesterol were 4.9 times of those with lower TC value. Subjects with high triglyceride had a prevalence 5.7 times of those who had lower TG. Those HDL-ch had a prevalence 68.7% higher than those with normal HDL-ch value; on the other hand, those HDL-ch > 1.91 mmol/L were 44.6% lower in the prevalence than those with normal HDL-ch. The prevalence of type 2 diabetes in subjects with BMI >or= 25 were 2.6 times of those with BMI < 25. Subject with hypertension (>or= 140/90 mm Hg) had a prevalence 3.8 times of those with normal blood pressure. Subjects with family history of type II diabetes had a prevalence 2.0 times of no family history, and women who had delivered babies over 4 kg had a prevalence 1.9 times of those who had babies less than 4 kg. Subjects with waist/hip ratio (WHR) >or= 1.0 had a prevalence 5.1 times of those with WHR < 1.0. The prevalence of type 2 Diabetes was higher with increasing amount of cigarette smoking and the duration (in years) of smoking or increasing drinking (alcohol) and the duration (in years) of drinking. CONCLUSIONS: The blood glucose level was found to be positively correlated with TC or TG, and negatively correlated with HDL-ch. This study demonstrated again that TC, TG, HDL-ch, obesity, hypertension, family history of type 2 diabetes and in women, delivery of babies over 4 kg and age were risk factors of type 2 diabetes.

Adult↗
PubMed2000

[Study on the xenoantigens of pancreatic tissues of Chinese Neijiang pig].

The expression and distribution of xenoantigens in pancreatic tissue of Neijiang pig were investigated with immunohistochemistry technique. BSIB4, normal human serum and anti-human A, B, H monoclonal antibodies were used as the primary antibody to examine the expression of xenoantigens in the pancreatic tissues from 10 Neijiang pigs. The results demonstrate that compared with the negative results of human blood B and H type antigens, the alpha-Gal antigen was highly expressed on the pancreatic vascular endothelial cells and the duct epithelium. The human blood A type antigen was highly expressed on some islet cells, some exocrine secretory cells and all the duct epithelium. Since there are pre-exited xenoantibodies against pig pancreas cells in human serum, cross-matching test and graft pre-treatment are needed before clinical transplantation of pancreas. The expression of xenoantigens in Neijiang pig is different from other pig strains reported by others, which suggests that looking for a pig strain that contains less xenoantigens is possible.

ABO Blood-Group System↗
PubMed2000

[Studies on flavonoids from leave of Eucommia ulmoides Oliv].

OBJECTIVE: To separate the constituents from Eucommia ulmoides. METHOD: The constituents were separated by the repeated chromatography and identified by spectral methods. RESULT: The seven compounds were obtained, which were kaempferol(1), quercetin(2), astragalin(3), hirsutin(4), rutin(5), 3,4-dihydrobenzonic acid(6), ethyl glucopyranoside(7). CONCLUSION: Compounds 3-7 were obtained from leaves of E. ulmoides for the first time.

Alkaloids↗
PubMed2000

[Immune reconstitution in immunosuppressed pigs with human immune competent cells].

To reconstitute the immune system of the pig with human immune cells after destroying or suppressing it, so that the transplant immunoreactivity between human and pig could be monitored in vivo. Fifteen Chinese Neijiang pigs were divided into 3 groups. Group A (n = 5) received immunosuppression through intravenous infusion of methotrexate (MTX), myleran and cyclophosphamide (CTX). Group B received intraperitoneal injection of human bone marrow and spleen cells (HBSC) after the same treatment as group A. Group C (n = 5) received intravenous infusion of HBSC after the same treatment as group A. Blood routines and biochemical analysis were monitored. The chimerisms of human cells were supervised through immunohistochemistry of cytospin of peripheral blood from recipient pigs and flow cytometry of the same specimen and immunohistochemistry of frozen tissue sections and paraffin sections. All pigs in group A survived definitely. Group B and C survived 3 days to 54 days and 15 hours to 60 days respectively. The peripheral white blood cell count (WBCC) of group A, B and C decreased to the bottom 7 days after drug administration, about 1%-10% of the normal level. After transplantation, the WBCC of group B and C recovered more slowly than those of group A. Human cells were found in the recipient pigs of group B and C after transplantation through immunohistochemistry of peripheral blood cytospin and flow cytometry. Infiltration of human cells was found in the spleens and lungs of group C and D through immunohistochemistry. The chimerism of human cells in recipient pigs could be established by transplanting human bone marrow and spleen cells into immunosuppressed pigs. It is possible that XGVHD occurs in the recipient, which offers a novel animal model for studies on immunoreactivity of pig-to-human xenotransplantation. The proportions of human cells in peripheral blood of recipient pigs are low long after transplantation through both intraperitoneal injection and intravenous infusion.

Animals↗
PubMed2000

[Expression of TGF-beta 1 and proliferation of collagen in myocardium in viral myocarditis].

To investigate the tissue repair of acute viral myocarditis, and to explore the diagnostic method of slight viral myocarditis in forensic pathology. Slight viral myocarditis model was induced in Balb/c murine by CVB3. Collagen proliferation in myocardium of mice with myocarditis was observed by special staining. The hearts of mice and human(9 cases) with myocarditis were studied LSAB-immunohistochemically with anti-TGF-beta 1 antibody. In the study, the proliferation of collagen was seen in myocardium in acute viral myocarditis. Generous expression of TGF-beta 1 was found in the myocardium of mice and human with myocarditis. The quantity of collagen proliferation and expression of TGF-beta 1 was positive correlation. It is concluded that the tissue repair exists in acute viral myocarditis and that positive staining of myocardium for TGF-beta 1 is a sensitive index of myocardial damage and tissue repair.

Animals↗