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Biomedical subjects

S Wang

Publications and source records attributed to S Wang.

At least 361 records · Page 20Linked to original sources
PubMed2001

[Treatment of nuclein 32P colloid perfusion with chronic suppurative maxillary sinusitis].

OBJECTIVE: To determine the effect of nuclein 32P colloid in treatment of chronic maxillary sinusitis (CMS). METHOD: 22 patients (31 sides) with CMS after washing of sinucavity were perfused with nuclein 32P in sinucavity. 20 patients (31 sides) with routine conservative treatment were served as a control group. Two groups were followed up for one year. RESULT: In nuclein group, 27 sides were cured, 4 sides were recurred and the rate of cure was 87%. In routine group, 19 sides were cured, 12 sides were recurred and the rate of cure is 61%. There is significant difference between the two groups (P < 0.01). The treatment active of nuclein group is better than that of routine group. CONCLUSION: Nuclein 32P colloid with the function of ionizing radiation can increase the pathogenic tissue immunocompetence and metabolic course, obstruct the microvascular and promote the absorption of inflammatory exudation and edema subsidence. It can also make the proliferous tissue atrophy thence accelerate the rate of cure of CMS.

Adult↗
PubMed2001

[Changes and relations of leptin, growth hormone and insulin during puberty in obese and non-obese children].

In order to study the regularity of changing leptin, growth hormone (GH) and insulin (INS) during puberty and their relationships, a group of 300 obese and 300 non-obese children, aged 10-15 were selected. Leptin level increased with age and then decreased in boys, but it had only increasing tendency in girls. The GH level increased and then decreased suddenly in all groups. There was no obvious regularity in the change of INS. Serum leptin and INS levels were higher (P < 0.01) in obese children than that in non-obese children, while GH levels were significantly lower (P < 0.01) in obese boys. Results also showed that GH was negatively correlated with leptin in boys (obese group: r = -0.74, P < 0.05; non-obese group: r = -0.69, P < 0.05) and positively correlated with leptin in girls (obese group: r = 0.58, P < 0.05; non-obese group: r = 0.67, P < 0.01). There was a positive correlation between INS and leptin in non-obese girls (r = 0.54, P < 0.05). It is concluded that leptin might play an important role during the initial stage of puberty in children and the effect of leptin on pubescent development in girls is greater compared with boys. The correlation between leptin and GH are gender dependent in boys and girls, which may cause the timing differences of sudden growth in boys and girls.

Adolescent↗
PubMed2001

[Effects of chromium and fish oil on insulin resistance and leptin resistance in obese developing rats].

In order to study the effects of chromium and fish oil on insulin resistance and leptin resistance in obese rats, 50 rats were divided randomly into five groups: basal diet group was fed on normal diet, other four groups were fed on high fat diet. In addition to high fat diet, chromium group fed chromium (3 mg/kg BW), fish oil group fish oil(5 ml/kg BW) and chromium + fish oil group fed chromium(3 mg/kg BW) plus fish oil(5 ml/kg BW). Blood samples were collected in the following five weeks from tail each week to determine blood sugar, insulin and leptin. The results showed that blood sugar, insulin and leptin in fish oil group and chromium group were lower than those in high fat diet control group. Chromium and fish oil improved the insulin resistance and leptin resistance.

Animals↗
PubMed2001

[Biochemical remodeling of myocardial collagen and its relation to cardiac renin-angiotensin system in rats after myocardial infarction].

OBJECTIVE: This study aimed at the biochemical remodeling of myocardial collagen and its relation to cardiac renin-angiotensin system (RAS) after myocardial infarction(MI). METHODS: The ventricular and plasma angiotensin II (Ang II) content, total collagen content, and collagen concentration in left ventricle(LV) and right ventricle(RV) of MI and sham-operated control(SOC) rats on 3, 15 and 42 days after operation were measured dynamically by means of radioimmunoassay etc. RESULTS: The plasma Ang II content increased only in MI rats on day 3. The Ang II content in LV of the MI group increased markedly on day 3 after MI as compared with that of the SOC group. It sustained at this higher level on the 15th and 42th days, and the similar changes were observed in RV as well. The biochemical remodeling of collagen in LV and RV occurred after MI and the remodeling of collagen showed similar patterns with its Ang II content, except that collagen remodeling in RV was delayed than the change of Ang II content. CONCLUSION: The cardiac RAS was obviously activated after MI. Ventricular Ang II might play an important role in the biochemical remodeling of myocardial collagen, and its role was independent of circulating RAS.

Angiotensin II↗
PubMed2001

[Ultrastructure changes of the olfactory epithelium of the patients suffering from dysosmia caused by the chronic sinusitis].

OBJECTIVE: To observe the ultrastructural changes of olfactory epithelium (OE) in patients suffering from dysosmia caused by chronic sinusitis. METHODS: The specimens of olfactory epithelium were obtained from 35 patients operated for chronic sinusitis accompanied by dysosmia. According to the results of light microscope (LM) examination, the OE was divided into three groups by the types of pathological changes: normal, atrophic and respiratory epithelium metaplasia(REM). Transmission electron microscope was used to observe the ultrastructural changes of each group. RESULTS: Under the LM, the surface ultrastructure of the OE showed some abnormal changes: (1) surface microvillus of the supporting cells disappeared; (2) olfactory vesicle changed their shape due to vacuolization; (3) disappearance of canaliculus structure in the olfactory vesicle; (4) the olfactory cilia changed the shape or reduced; some of the reduced cilia underwent metaplasia. The ultrastructural changes of atrophic OE included: (1) minor and moderate atrophy: the organelles and the membrane-limited electron dense vesicles on the upper section of the supporting cells obviously decreased or disappeared, even underwent vacuolization. The basic cell degenerated; (2) serious atrophy: the turbidity of the cell structure, even double cell structure, the nuclei of the cell aggregated as the plaque and vesiculose change or karyopyknosis. As for the cytoplasm, there were the dilation of the ERs, turgidity of the mitochondrion, the disarrangement, diminution and vacuolization. Fasciculate cilia were distributed separately in the REM group. CONCLUSION: There is a positive relationship between the atrophy degree and the degree of the abnormal ultrastructural changes of the OE. The ultrastructural changes of OE in patients suffering from dysosmia caused by chronic sinusitis may provide reference for assessment of the treatment of dysosmia.

Adult↗
PubMed2001

[Pharyngeal passage tube treatment for obstructive apnea syndrome].

OBJECTIVE: To investigate the therapeutical effect of pharyngeal passage tube for OSAS. METHODS: Fifty-seven patients were treated during May 1995 to August 1999. All patients were examined by GKD-405 A polysomnography for apnea index (AI), hypnea index (HI), AHI (AI + HI) at cetera 7 items index before and after pharyngeal passage tube treatment. RESULTS: After treatment, the longest time of apnea shortened from (54.82 +/- 20.83) s to (25.74 +/- 9.50) s, the AHI lessened from 70.82 +/- 18.06 to 30.00 +/- 10.10, the oxygen desaturation increased from (62.36 +/- 11.53)% to (78.68 +/- 12.09)%. After treatment, the recorded parameters showed obvious therapeutical effect (P < 0.05-0.001, t values is from 2.20 to 15.29, the snore loudness of all patients dropped from (84.32 +/- 18.51) dB to (32.64 +/- 10.16) dB. The therapeutical successful rate was 87.72%. The long-term use rate (over 6 months) was 72.73%. CONCLUSION: The pharyngeal passage tube has obvious effect for patients suffering from severe OSAS. It is recommended for the treatment of OSAS as a conservative method.

Adult↗
PubMed2001

The roles of bcl-2 gene family in the pulmonary artery remodeling of hypoxia pulmonary hypertension in rats.

OBJECTIVE: To investigate the roles of apoptosis in the pulmonary artery remodeling of pulmonary hypertension secondary to hypoxia and illustrate the relative genes expression. METHODS: Thirty rats were divided into hypoxia group (10% O2, 8 h/d) and normal control group. On the 15th day of hypoxia, pulmonary artery pressure and right ventricular hypertrophy index were measured and pulmonary artery vessels were studied by light microscope. Then terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) technique was used to detect nucleosomal DNA fragmentation of apoptotic cells. In situ hybridization and RT-PCR were used to detect the expression level of bcl-2 and bax. RESULTS: The pulmonary artery pressure and right ventricular hypertrophy index of hypoxia group were increased significantly, the pulmonary artery wall of hypoxic group become incrassate than control group. Apoptotic cells can be found in lung with hypoxia or without hypoxia. Compared with control group, apoptotic index of hypoxic group decreased significantly. Through the methods of in situ hybridization and RT-PCR, we found the expression of bcl-2 increased whereas bax decreased significantly in the hypoxic group. CONCLUSION: The alternation in bcl-2 and bax expression induced by hypoxia play an important role in the pulmonary artery remodeling which is the main pathologic change of pulmonary hypertension secondary to hypoxia.

Animals↗
PubMed2001

[Study on the expression of human acute myeloid leukemia retrovirus gene].

OBJECTIVE: To explore the potentiality of retroviral etiology in human acute myeloid leukemia (AML). METHODS: The expression of retrovirus clone 6 # 11 in leukemic cells from 19 AML patients and peripheral blood mononuclear cells (PBMNCs) from 20 controls was studied by Northern blot and reverse transcriptase polymerase chain reaction (RT-PCR). RESULTS: Northern blot revealed the positive bands of 9.4 kb and 4.5 kb in 18 of 19 AML patients, and RT-PCR a 790 bp product in 11 of 14 AML patients. CONCLUSION: There was a specific expression of acute myeloid leukemia associated retrovirus in AML patients.

Adolescent↗
PubMed2001

[Hepatic trisegmentectomy for 29 patients with huge neoplasms of liver].

OBJECTIVE: To evaluate the feasibility and effect of hepatic trisegmentectomy for patients with huge neoplasms of liver. METHODS: From July 1993 to October 1999, 29 patients with huge hepatic neoplasms underwent hepatic trisegmentectomy, (23 patients with primary liver cancer, 1 patient with hepatic infiltration of gallbladder cancer, 1 patient with metastasis of colon cancer, 1 patient with hepatic angiosarcoma, 1 patient with hepatic neurofibroma, and 2 patients with huge liver cyst). Of these patients, 26 underwent right trisegmentectomies and the rest 3 accepted left trisegmentectomies. All trisegmentectomies were performed under normothermic interruption of the porta hepatis at single time and these interruptions lasted 15 to 40 minutes. RESULTS: The relatively good effect was seen in our series of trisegmentectomies. The 1-, 3-, 5-year survival rates for patients with primary liver cancer were 63.6%, 36.4% and 27.3%, respectively. The survival time for patients with hepatic infiltration of gallbladder cancer and metastasis of colon cancer in the liver was 6 months. The patients with hepatic angiosarcoma, hepatic neurofibroma and 2 huge liver cysts survived 35, 26, 25, 40 months and 1 till to the latest follow-up, respectively. Main complications were present in 5 patients. Mortality within 1 month was 3.4% (1/ 29). CONCLUSION: Hepatic trisegmentectomy is safe and effective in treatment of huge hepatic neoplasms if its indications and operative techniques are mastered properly.

Carcinoma, Hepatocellular↗
PubMed2000

Interaction of MyoD family proteins with enhancers of acetylcholine receptor subunit genes in vivo.

The myogenic determination factors (MDFs) are transcriptional activators that target E boxes in many muscle-specific promoters, including those of the genes coding for the subunits of the acetylcholine receptor. It is not known, however, if in vivo a given E box in a transcriptionally active gene is occupied, either uniquely by one MDF or randomly by all MDFs. We have analyzed expression of MDF and acetylcholine receptor subunits in cultured mouse muscle cells and, using chromatin immunoprecipitation, have determined which individual MDFs reside at promoters of several receptor subunit genes. We find that before fusion, C2C12 cells express myf-5, MyoD, and myogenin, all of which take up residence at promoters of all subunits except epsilon. At this stage, herculin is present in limited amounts and is detected mainly at the gamma and delta subunit genes. On myotube formation, herculin reaches high levels; concomitantly, the epsilon subunit gene becomes a common MDF target and begins to be expressed. In general, any MDF protein that is expressed also is present on transcriptionally active receptor genes; transcriptional activity of target genes correlates with occupancy by MDF, in particular, herculin.

Animals↗
PubMed2000

A novel hepatointestinal leukotriene B4 receptor. Cloning and functional characterization.

Leukotriene B(4) (LTB(4)) is a product of eicosanoid metabolism and acts as an extremely potent chemotactic mediator for inflammation. LTB(4) exerts positive effects on the immigration and activation of leukocytes. These effects suggest an involvement of LTB(4) in several diseases: inflammatory bowel disease, psoriasis, arthritis, and asthma. LTB(4) elicits actions through interaction with one or more cell surface receptors that lead to chemotaxis and inflammation. One leukotriene B(4) receptor has been recently identified (LTB(4)-R1). In this report we describe cloning of a cDNA encoding a novel 358-amino acid receptor (LTB(4)-R2) that possesses seven membrane-spanning domains and is homologous (42%) and genetically linked to LTB(4)-R1. Expression of LTB(4)-R2 is broad but highest in liver, intestine, spleen, and kidney. In radioligand binding assays, membranes prepared from COS-7 cells transfected with LTB(4)-R2 cDNA displayed high affinity (K(d) = 0.17 nm) for [(3)H]LTB(4). Radioligand competition assays revealed high affinities of the receptor for LTB(4) and LTB(5), and 20-hydroxy-LTB(4), and intermediate affinities for 15(S)-HETE and 12-oxo-ETE. Three LTB(4) receptor antagonists, 14,15-dehydro-LTB(4), LTB(4)-3-aminopropylamide, and U-75302, had high affinity for LTB(4)-R1 but not for LTB(4)-R2. No apparent affinity binding for the receptors was detected for the CysLT1-selective antagonists montelukast and zafirlukast. LTB(4) functionally mobilized intracellular calcium and inhibited forskolin-stimulated cAMP production in 293 cells. The discovery of this new receptor should aid in further understanding the roles of LTB(4) in pathologies in these tissues and may provide a tool in identification of specific antagonists/agonists for potential therapeutic treatments.

Amino Acid Sequence↗
PubMed2000

Myomegalin is a novel protein of the golgi/centrosome that interacts with a cyclic nucleotide phosphodiesterase.

Subcellular targeting of the components of the cAMP-dependent pathway is thought to be essential for intracellular signaling. Here we have identified a novel protein, named myomegalin, that interacts with the cyclic nucleotide phosphodiesterase PDE4D, thereby targeting it to particulate structures. Myomegalin is a large 2,324-amino acid protein mostly composed of alpha-helical and coiled-coil structures, with domains shared with microtubule-associated proteins, and a leucine zipper identical to that found in the Drosophila centrosomin. Transcripts of 7.5-8 kilobases were present in most tissues, whereas a short mRNA of 2.4 kilobases was detected only in rat testis. A third splicing variant was expressed predominantly in rat heart. Antibodies against the deduced sequence recognized particulate myomegalin proteins of 62 kDa in testis and 230-250 kDa in heart and skeletal muscle. Immunocytochemistry and transfection studies demonstrate colocalization of PDE4D and myomegalin in the Golgi/centrosomal area of cultured cells, and in sarcomeric structures of skeletal muscle. Myomegalin expressed in COS-7 cells coimmunoprecipitated with PDE4D3 and sequestered it to particulate structures. These findings indicate that myomegalin is a novel protein that functions as an anchor to localize components of the cAMP-dependent pathway to the Golgi/centrosomal region of the cell.

3',5'-Cyclic-AMP Phosphodiesterases↗
PubMed2000

The structure of the T127L/S128A mutant of cAMP receptor protein facilitates promoter site binding.

The x-ray crystal structure of the cAMP-ligated T127L/S128A double mutant of cAMP receptor protein (CRP) was determined to a resolution of 2.2 A. Although this structure is close to that of the x-ray crystal structure of cAMP-ligated CRP with one subunit in the open form and one subunit in the closed form, a bound syn-cAMP is clearly observed in the closed subunit in a third binding site in the C-terminal domain. In addition, water-mediated interactions replace the hydrogen bonding interactions between the N(6) of anti-cAMP bound in the N-terminal domains of each subunit and the OH groups of the Thr(127) and Ser(128) residues in the C alpha-helix of wild type CRP. This replacement induces flexibility in the C alpha-helix at Ala(128), which swings the C-terminal domain of the open subunit more toward the N-terminal domain in the T127L/S128A double mutant of CRP (CRP*) than is observed in the open subunit of cAMP-ligated CRP. Isothermal titration calorimetry measurements on the binding of cAMP to CRP* show that the binding mechanism changes from an exothermic independent two-site binding mechanism at pH 7.0 to an endothermic interacting two-site mechanism at pH 5.2, similar to that observed for CRP at both pH levels. Differential scanning calorimetry measurements exhibit a broadening of the thermal denaturation transition of CRP* relative to that of CRP at pH 7.0 but similar to the multipeak transitions observed for cAMP-ligated CRP. These properties and the bound syn-cAMP ligand, which has only been previously observed in the DNA bound x-ray crystal structure of cAMP-ligated CRP by Passner and Steitz (Passner, J. M., and Steitz, T. A. (1997) Proc. Natl. Acad. Sci. U. S. A. 94, 2843-2847), imply that the cAMP-ligated CRP* structure is closer to the conformation of the allosterically activated structure than cAMP-ligated CRP. This may be induced by the unique flexibility at Ala(128) and/or by the bound syn-cAMP in the hinge region of CRP*.

Bacterial Proteins↗
PubMed2000

Identification of a novel neuromedin U receptor subtype expressed in the central nervous system.

Neuromedin U is a neuropeptide prominently expressed in the upper gastrointestinal tract and central nervous system. Recently, GPR66/FM-3 (NmU-R1) was identified as a specific receptor for neuromedin U. A BLAST search of the GenBank(TM) genomic database using the NmU-R1 cDNA sequence revealed a human genomic fragment encoding a G protein-coupled receptor that we designated NmU-R2 based on its homology to NmU-R1. The full-length NmU-R2 cDNA was subsequently cloned, stably expressed in 293 cells, and shown to mobilize intracellular calcium in response to neuromedin U. This response was dose-dependent (EC(50) = 5 nm) and specific in that other neuromedins did not induce a calcium flux in receptor-transfected cells. Expression analysis of human NmU-R2 demonstrated its mRNA to be most highly expressed in central nervous system tissues. Based on these data, we conclude that NmU-R2 is a novel neuromedin U receptor subtype that is likely to mediate central nervous system-specific neuromedin U effects.

Amino Acid Sequence↗
PubMed2000

Improving the performance of MALDI-TOF in oligonucleotide analysis using a new SDIFA technology.

A new technology termed SDIFA is developed to improve the mass resolution of linear matrix-assisted laser desorption/ionization time-of-flight mass spectrometry in oligonucleotide analysis. Unlike the currently used delayed extraction method, SDIFA allows electrical isolation of the sample holder from ion extraction/acceleration and selectively samples part of the desorbed ions, thereby reducing the initial velocity distribution and improving resolution. In addition, a method was introduced to improve the space focusing of TOF. Isotope-limited mass resolution was obtained for oligonucleotides of up to 62 mer, and the true instrumental resolution reaches to 1,800 at 19.2 kDa. It was also demonstrated that excellent resolution was obtained across a large mass range using a single setting of acquisition parameters. This feature allows unambiguous identification of multiple A/T heterozygote samples in a mass range of 5,200-7,800 Da. Moreover, compared with DE, the performance of SDIFA was more stable, reproducible, and less dependent on the experimental conditions including the laser power, sample spots, sample substrates, delayed time, and extraction field strength. This enhanced ease of data acquisition is the key to automated spectrum acquisition.

Oligonucleotides↗
PubMed2000

Immunogenicity of a hexavalent combination vaccine in rhesus monkeys.

Preclinical immunogenicity studies were conducted in rhesus monkeys to determine whether there is immune interference in the response to one or more components of a hexavalent vaccine (Hexavac) that contains antigens from Haemophilus influenzae (Hib), hepatitis B (HB), diphtheria (D), tetanus (T), acellular pertussis (aP) and inactivated polio virus (IPV). Antibody responses were measured following co-administration of the components at three separate anatomical sites or administration as a hexavalent combination in a single site. After three injections of the hexavalent vaccine, the peak antibody responses to each component of the vaccine were >100-fold above pre-immune titers and persisted at levels >10-fold above pre-immune titers at approximately 1 year. Immune interference was observed in the peak response to HB, D and pertussis toxin, but was not seen at later time points. The results indicate that the rhesus monkey model may be useful for pre-clinical evaluation of combination vaccines.

Animals↗