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Biomedical subjects

Cheng Zhu

Publications and source records attributed to Cheng Zhu.

At least 73 records · Page 4Linked to original sources
PubMed2003

Effects of ganglioside GM1 on reduction of brain edema and amelioration of cerebral metabolism after traumatic brain injury.

OBJECTIVE: To observe the effects of ganglioside GM1 on reduction of brain edema and amelioration of cerebral metabolism after traumatic brain injury (TBI). METHODS: An acute experimental closed TBI model in rats was induced by a fluid-percussion brain injury model. At five and sixty minutes after TBI, the animals were intraperitoneally injected by ganglioside GM1 (30 mg/kg) or the same volume of saline. At the 6th hour after TBI, effects of ganglioside GM1 or saline on changes of mean arterial pressure (MAP), contents of water, lactic acid (LA) and lipid peroxidation (LPO) in the injured cerebral tissues were observed. RESULTS: After TBI, MAP decreased and contents of water, LA and LPO increased in brain injury group; however, MAP was back to normal levels and contents of water, LA and LPO decreased in ganglioside GM1 treated group, compared with those in brain injury group (P < 0.05). No significant difference between the saline treated group and the brain injury group (P > 0.05) was observed. CONCLUSIONS: Ganglioside GM1 does have obvious neuroprotective effect on early TBI.

Animals↗
PubMed2003

Standard large trauma craniotomy for severe traumatic brain injury.

OBJECTIVE: To study the effect of standard large trauma craniotomy (SLTC) on outcomes of patients with severe traumatic brain injury (TBI) (GCS<=8). METHODS: 230 patients with severe TBI were randomly divided into two groups. 115 patients underwent SLTC (10 cm x 12 cm) as an SLTC group, and other 115 patients underwent temporo-parietal or fronto-temporal craniotomy (6 cm x 8 cm) according to the position of hematomas as a routine craniotomy (RC) group. Other treatments were identical in two groups. According to Glasgow outcome scale (GOS), the prognosis of the patients was evaluated and the complications were compared between two groups. RESULTS: 27 patients got good outcome and moderate disability (23.5%), 40 severe disability and vegetative survival (34.8%), and 48 died (41.7%) in SLTC group. 21 patients got good outcome and moderate disability (18.3%), 28 severe disability and vegetative survival (24.3%), and 66 died (57.4%) in RC group. The incidence of incision hernia was lower in SLTC group than in RC group. However, the incidence of operative encephalocele, traumatic epilepsy and intracranial infection were not different in two groups. CONCLUSIONS: Standard large trauma craniotomy significantly reduces the mortality of patients with severe TBI without serious complications, but does not improve the life quality of the patients.

Adult↗
PubMed2003

[Observation amyloplasts in the gravity-insensitive mutant of rice under gravity and microgravity conditions].

Using histochemistry and optical microscope, we examined the number and the size of amyloplasts in specialized tissues of gravitropically receptive organs-tissues such as the coleoptile and sheath of rice mutant (insensitive to gravity) and wide type (Oryza sativa L. subsp. japonica) (Zhonghua 11). We found there was no statistical difference between the mutant and wide type, both of which grew on earth or on the clinostat respectively. On earth, it was found that amyloplasts sedimented at the distal end of each cell of the special starch sheath tissues and re-sedimentation of amyloplasts toward the direction of gravity was almost completed in 5 minutes after inverting the seedlings. On the clinostat, amyloplasts dispersed in the starch sheath tissue. Such observations indicated that the mutation was not resulted from the starch-deficiency or starch-absence, the further research is going on.

Gravitation↗
PubMed2003

[Association of human leukocyte antigen non-classical genes with type 1 diabetes].

OBJECTIVE: HLA-DMA and DMB are non-classical genes whose product (DM molecules) plays an important role in antigen presentation. Our present study was designed to investigate the relationship between human leukocyte antigen-DMA, -DMB and clinical status heterogeneity of type 1 diabetes. METHODS: A total of 80 children (male 36, female 44) with type 1 diabetes were selected as research subjects. Diagnosis of type 1 diabetes was made according to WHO criteria. The range of age at onset of type 1 diabetes was 2.5 - 14 years. Ninety-one healthy adult blood donors were selected as normal controls. Polymerase chain reaction and dot blot hybridization techniques were used to classify DMA and DMB alleles. Patients with type 1 diabetes were classified into different groups according to different clinical status, including sex, age of onset, ketosis onset situation on diagnosis, remained function of islet beta cell, etc. Then distribution of DM susceptive alleles and heterodimer in different clinical groups were studied. RESULTS: The frequencies of DMA * 0103 and DMB * 0103 alleles in patients were significantly increased (50% vs. 8%, 43% vs. 22%, respectively), these two alleles confer susceptibility to type 1 diabetes in Chinese. The frequencies of DMA * 0103/DMB * 0102, DMA * 0103/DMB * 0103 and DMA * 0103/DMB * 0101 heterodimers were also increased in the patients. The above heterodimers confer predisposition to type 1 diabetes. Both DMB * 0103 allele and DM susceptive heterodimers are related to islet beta cell function on diagnosis. The patients with DMB * 0103 allele or DM susceptive heterodimers were significantly increased in the patients with lower C-peptide level on diagnosis (56% vs. 29%; 58% vs. 34% respectively). DM heterodimes were also related to onset age and ketosis-onset-situations of the patients. The patients carrying DM susceptive heterodimers had higher probability to suffer type 1 diabetes before 10 years of age and had the predisposition to ketosis or ketoacidosis on diagnosis. CONCLUSION: HLA- class II non-classical alleles-DMA and DMB may play an important role in pathogenesis of type 1 diabetes, and clinical status heterogeneity of type 1 diabetes may be related to genetic mechanism.

Adolescent↗
PubMed2002

Distinct molecular and cellular contributions to stabilizing selectin-mediated rolling under flow.

Leukocytes roll on selectins at nearly constant velocities over a wide range of wall shear stresses. Ligand-coupled microspheres roll faster on selectins and detach quickly as wall shear stress is increased. To examine whether the superior performance of leukocytes reflects molecular features of native ligands or cellular properties that favor selectin-mediated rolling, we coupled structurally defined selectin ligands to microspheres or K562 cells and compared their rolling on P-selectin. Microspheres bearing soluble P-selectin glycoprotein ligand (sPSGL)-1 or 2-glycosulfopeptide (GSP)-6, a GSP modeled after the NH2-terminal P-selectin-binding region of PSGL-1, rolled equivalently but unstably on P-selectin. K562 cells displaying randomly coupled 2-GSP-6 also rolled unstably. In contrast, K562 cells bearing randomly coupled sPSGL-1 or 2-GSP-6 targeted to a membrane-distal region of the presumed glycocalyx rolled more like leukocytes: rolling steps were more uniform and shear resistant, and rolling velocities tended to plateau as wall shear stress was increased. K562 cells treated with paraformaldehyde or methyl-beta-cyclodextrin before ligand coupling were less deformable and rolled unstably like microspheres. Cells treated with cytochalasin D were more deformable, further resisted detachment, and rolled slowly despite increases in wall shear stress. Thus, stable, shear-resistant rolling requires cellular properties that optimize selectin-ligand interactions.

Carrier Proteins↗
PubMed2002

Scope and diastereoselectivity of the "interrupted" Feist-Bénary reaction.

[reaction: see text] The base-promoted condensation of beta-dicarbonyl compounds with alpha-haloketones, the Feist-Bénary reaction, conveniently produces highly substituted dihydrofurans. We show here that this reaction is quite general with respect to the nature of the beta-dicarbonyl compound, proceeding with beta-ketoesters, beta-oxopropionates, beta-diketones, and beta-dialdehydes. We also show that the diastereoselectivity of this reaction depends on the acidity of the nucleophile.

Antifungal Agents↗
PubMed2002

Rapid synthesis of the 7-deoxy zaragozic acid core.

[reaction: see text] We have developed an efficient synthesis of the 7-deoxy zaragozic acid core. The synthesis begins with a Feist-Bénary reaction that assembles all three carbons of the polycarboxylic acid portion of the core. This reaction is followed by highly diastereoselective aldol and dihydroxylation reactions that set the remaining stereocenters of the core. The synthesis finishes with lactol oxidation and lactone alcoholysis/ketal formation reactions to construct the bicyclic ring system of the core.

Antifungal Agents↗
PubMed2002

Expression of matrix metalloproteinase -2, -9 and tissue inhibitors of metalloproteinase -1, -2, -3 mRNAs in rat uterus during early pregnancy.

Zymography and in situ hybridizition were used to investigate matrix metalloproteinase-2, -9 (MMP-2, -9) activities, and expression of mRNAs for MMP-2, -9 and tissue inhibitors of matrix metalloproteinases (TIMP-1, -2, -3) in the rat uterus during early pregnancy (day 1-7). The zymography results showed two forms of MMP-2 (64 and 67 kDa) in the rat uteri during early pregnancy. The 64-kDa MMP-2 activity was the highest on day 2 (P < 0.01) and higher on day 5 and 6 (P < 0.05). The 67-kDa MMP-2 activity reached the highest on day 5 and 6 (P < 0.01). The 64-kDa MMP-2 activity at the implantation sites was higher than those at interimplantation sites (P < 0.05). Furthermore, the 67 kDa MMP-2 can be converted to 64 kDa forms by incubation with p-aminophenylmercuric acetate (APMA) and trypsin in vitro. The 92-kDa MMP-9 activity was only detected on day 5 and 6 of pregnancy (P < 0.01). In situ hybridization showed that on day 1-4 of pregnancy, both MMP-2 and TIMP-2 mRNAs were evidently localized in the basal stromal cells. On day 5, MMP-2 mRNA signals were decreased in the basal stromal cells and mRNA for TIMP-2 was expressed in the epithelial cells and subepithelial stromal cells. The mRNAs for MMP-9, TIMP-1, and -3 were mainly expressed in epithelial cells on day 1-5. At the implantation site on day 6, the mRNAs for MMP-2, -9, TIMP-1, -2, and -3 were highly expressed in the primary decidual zone surrounding the implanting embryo, and in the whole decidualized stromal cells (the primary and secondary decidual zones) at the implantation site on day 7. The intensities of mRNAs for the TIMPs in decidualized stromal cells at the implantation site on day 6 and 7 were stronger than those for the MMPs. The weak mRNAs for MMP-2, -9, TIMP-1, and -3 but not TIMP-2 were also observed in the ectoplacental cone/trophoblastic cells of the implanting embryos. However, at the interimplantation sites on day 6 and 7, MMP-2, -9, TIMP-1, -2, and -3 mRNAs were weakly expressed in the epithelial cells, subepithelial stromal cells, and myometrium. The results suggested that the implanting rat embryo strongly induced MMP-2 and -9 proteins and gene expression for decidulization and embryo invasion, which were strictly controlled and balanced by the simultaneous expression of TIMP-1, -2 and -3.

Animals↗
PubMed2002

Expression of gelatinases and their tissue inhibitors in rat corpus luteum during pregnancy and postpartum.

Extensive tissue remodeling occurs in the corpus luteum (CL) during both formation and luteolysis. Matrix metalloproteinases (MMPs) and their tissue inhibitors (TIMPs) are believed to play pivotal roles in these processes. In the present study, to evaluate the potential roles of matrix degrading proteases in luteal development and regression, we examined gelatinases and TIMP-1, -2, -3 mRNA expressions, as well as gelatinase activity in rat CL during pregnancy and postpartum using Northern blot, in situ hybridization, and gelatin zymography, respectively. The results showed that MMP-2 mRNA was only expressed at the early stages of pregnancy; TIMP-2 mRNA was highly expressed at the early and late pregnancy and day 1 postpartum, but could not be detected during the mid-phase of pregnancy; TIMP-3 mRNA expression was abundant during early pregnancy and peaked at day 7, but was absent from other time points examined. MMP-9 and TIMP-1 mRNAs in rat CL were below detectable level in the current study. Furthermore, the active MMP-2 was only present during the early stages of pregnancy, and no MMP-9 activity was observed in the zymogram. Taken together, our results suggest that MMP-2 and TIMP-3 may have functional roles in rat luteal formation, while TIMP-2 may be implicated in both formation and regression of the pregnant CL.

Animals↗
PubMed2002

Recombinant CD16A-Ig forms a homodimer and cross-blocks the ligand binding functions of neutrophil and monocyte Fcgamma receptors.

Receptors for the Fc region of IgG (FcgammaR) are expressed as membrane-bound and soluble forms in inflammatory cells. These receptors mediate a variety of immunoregulatory functions. FcgammaR-bearing neutrophils and macrophages play a major role in mediating immune complex induced inflammatory diseases and antibody-mediated tissue injury in autoimmune diseases. To delineate the biological role of the soluble FcgammaR, a recombinant soluble CD16A (CD16A-Ig) was expressed and characterized. CD16A-Ig is secreted as a disulfide-linked homodimer of 70kDa. The purified CD16A-Ig bound to human IgG1 and IgG3 immobilized onto ELISA plates and on IgG1- and IgG3-coated erythrocytes. Saturation binding studies and Scatchard plot analysis showed that immune complex bound to the purified CD16A-Ig with high avidity. Moreover, CD16A-Ig competitively blocked the binding of cell surface-expressed CD16A-CHO cells to IgG-coated plates. The dimeric CD16A-Ig also efficiently cross-blocked the binding of IgG-coated target cells to other FcgammaR expressed on neutrophils and monocytes. These results demonstrate that CD16A-Ig forms a high avidity dimer and is capable of blocking cell-cell interactions mediated by inflammatory cells expressing FcgammaR and IgG-coated target cells. These findings suggest that the dimeric FcgammaR molecules could be used therapeutically for the intervention of immune complex-mediated inflammatory disease.

Animals↗
PubMed2002

Early indicators of prognosis in 846 cases of severe traumatic brain injury.

A number of factors, including Glasgow coma scale (GCS) score, age, pupillary response and size, hypoxia, hyperthermia, and high intracranial pressure, may play an important role in predicting the outcome of traumatic brain injury. Eight hundred forty-six cases of severe traumatic brain injury (GCS < or = 8) were analyzed retrospectively to clarify the effects of multiple factors on the prognosis of patients. At 1 year after injury, the outcomes in these cases were as follows: good recovery, 31.56%; moderate disability, 14.07%; severe disability 24.35%; vegetative status, 0.59%; and death, 29.43%. The outcomes were strongly correlated (p < 0.05) with GCS score, age, pupillary response and size, hypoxia, hyperthermia, and high intracranial pressure (ICP). These findings indicate that prevention of hypoxia, control of high ICP, and prevention of hyperthermia may be useful means for improving the outcome of patients with severe head injury.

Adolescent↗
PubMed2002

Identification and specific expression of matrix metalloproteinase-26 in rhesus monkey endometrium during early pregnancy.

Matrix metalloproteinases (MMPs) and their tissue inhibitors may play important roles in tissue remodelling processes of the uterus. This study identified MMP-26 (endometase/matrilysin-2) in the endometrium of pregnant rhesus monkeys (Macaca mulatta) and monitored the spatial and temporal expression of the transcript and protein in the uteri on days 12, 18 and 26 of pregnancy. The partial monkey MMP-26 gene sequence of 289 nucleotides was 98% identical to that of its human homologue and its protein fragment contained a PHCGVPDGSD sequence in the prodomain identical to that in human MMP-26. RT-PCR analysis demonstrated that the average level of MMP-26 mRNA in the endometrium was high on day 12 of pregnancy, but significantly decreased on days 18 and 26 (P < 0.05). In-situ hybridization confirmed that MMP-26 mRNA is specifically localized in the endometrial compartments, with intense signals in the glandular epithelium on day 12 and in the walls of spiral arterioles adjacent to the implantation site on day 26. The hybridization signal for MMP-26 mRNA in the glandular epithelium decreased dramatically on day 18 and was undetectable on day 26. No MMP-26 mRNA transcripts were detected in the placental villi on days 18 and 26. Immunohistochemistry showed that the expression pattern of MMP-26 protein was similar to that of its mRNA. The restricted expression pattern of MMP-26 in the monkey uterus implies that this new MMP is involved in the highly regulated tissue remodelling processes of the glandular epithelium and spiral arteries during early pregnancy.

Actins↗
PubMed2002

Measuring receptor/ligand interaction at the single-bond level: experimental and interpretative issues.

There is increased interest in measuring kinetic rates, lifetimes, and rupture forces of single receptor/ligand bonds. Valuable insights have been obtained from previous experiments attempting such measurements. However, it remains difficult to know with sufficient certainty that single bonds were indeed measured. Using exemplifying data, evidence supporting single-bond observation is examined and caveats in the experimental design and data interpretation are identified. Critical issues preventing definitive proof and disproof of single-bond observation include complex binding schemes, multimeric interactions, clustering, and heterogeneous surfaces. It is concluded that no single criterion is sufficient to ensure that single bonds are actually observed. However, a cumulative body of evidence may provide reasonable confidence.

Cell Adhesion↗
PubMed2002

Preliminary exploration of the clinical effect of bleomycin on craniopharyngiomas.

OBJECTIVE: To investigate the antitumor effect of bleomycin on craniopharyngiomas. METHODS: A series of cystic craniopharyngiomas were randomly divided into three groups: (A) intracystic chemotherapy with bleomycin; (B) intracystic chemo-radiotherapy with bleomycin and (32)P; (C) intracystic radiotherapy with (32)P and 0.9% saline. The agents were injected into the cysts through stereotactically inserted silicone tubes. Follow-up was done for a minimum of 6 months. Outcome was based on a comparison of the volume of cysts before treatment and at follow-up. The index and lactate dehydrogenase (LD) of the cystic fluids, blood and cerebrospinal fluids and the endocrine function of these patients were determined before and after therapy. RESULTS: 19 patients finished the whole therapeutic course: 5 from group A, 9 from group B and 5 from group C. Four tumors in group A were polycystic, and the drug was selectively injected into the largest cyst. At follow-up, the volumes of the cysts in groups A and B regressed from 92 to 0%, while the drug-free cysts enlarged. In group B, 6 cysts almost disappeared and another 3 regressed from 78 to 57%. In group C, one cyst progressed and the others shrank by different degrees, but none disappeared completely or nearly. All patients in groups A and B had fever of different degrees, which resolved spontaneously in 8-24 h. The complications in group B included hyponatremia in 1 patient, and both adephagia obesity and cerebral infarction in 2 patients (1 of whom died after 6 months). Apart from the oculomotor paralysis occurring in 1 patient, the remainder of group C had no other severe complications. Blood chemistry, liver, kidney, pituitary and endocrinal functions changed little during the course in all these 19 patients. LD and its isoenzymes from the cystic fluids, CSF and serum showed no marked change after bleomycin injection. CONCLUSION: Bleomycin injected into cysts of craniopharyngiomas causes the tumor to shrink. When (32)P is added, the therapeutic effect seems better than treatment with either (32)P or bleomycin alone. Blood chemistry, liver, kidney and endocrine functions change little irrespective of the therapy applied. However, the combination of chemotherapy and radiotherapy may severely disturb both serum electrolytes and endocrine function. LD and its isoenzymes in the cystic fluids, CSF and serum may not change after bleomycin treatment.

Adolescent↗
PubMed2002

Expression and localization of RAP250 mRNA in rat ovary: possible implications in follicular development and ovulation.

The expression levels of nuclear receptor coregulators in specific tissue compartments and cells are thought to influence the expression of hormone-responsive genes involved in metabolism, development, and reproduction. RAP250 is a novel nuclear receptor coactivator highly expressed in brain and reproductive organs. To investigate the possible involvement of RAP250 in tissue-specific regulation of ovarian function, untreated immature, pregnant mare's serum gonadotropin luteinizing hormone (PMSG-LH)-primed, cycling, and pregnant rat models were used to study the localization and expression of RAP250 mRNA in rat ovary by in situ hybridization (ISH) and reverse transcriptase polymerase chain reaction (RT-PCR). The results showed that RAP250 mRNA was primarily localized to granulosa cells of healthy follicles in immature, cycling, and pregnant rats and increased during PMSG-induced follicular development. In the preovulatory and ovulatory follicles from the LH-primed rats of 48-h post-PMSG administration, the signals for RAP250 mRNA increased further and remained high until early luteal formation. Only a subset of corpora lutea during diestrus 1, diestrus 2, and initiation of pregnancy was weakly positive, and atretic follicles were largely negative. The RT-PCR results confirmed the presence of RAP250 mRNA in the rat ovary and strengthen the data from ISH. These findings suggest that RAP250 may play potential roles in follicular development and ovulation.

Animals↗
PubMed2002

Colonoscopic screening and follow-up for colorectal cancer in the elderly.

AIM: To improve the prevention and treatment of senile patients with colorectal cancer by evaluating the importance of colonoscopy in clinical screening and follow-up. METHODS: Clinical screening of colonoscopy was performed for 2196 patients aged 60-90 years old according to the protocol,and 1740 of them (79.2%) were followed-up. RESULTS: Colorectal cancer was found in 52 patients, and the detectable rate was 2.4%. Among them, 19 were diagnosed as early colorectal cancer, accounting for 36.5% of the detected colorectal cancer. Among the followed-up patients, early colorectal cancer was found in 9, accounting for 45.0% of the detected colorectal cancer. The resectable rate and 5 years survival rate of colorectal cancer were 97.7% and 80.9% respectively. The incidence of complication was 0.05%, and the successful rate of cecum intubation was 98.9%. CONCLUSION: Colonoscopic screening and follow-up of the elderly for colorectal cancer and pre-cancerous lesion (adenomatoid polyp) can increase the detectable rate of early colorectal cancer and improve its prevention and treatment.

Aged↗
PubMed2002

Spatial and temporal profile of apoptosis following lateral fluid percussion brain injury.

OBJECTIVE: To investigate the spatial and temporal profile of neural cell apoptosis following traumatic brain injury (TBI). METHODS: In addition to morphological evidence of apoptosis, TUNEL histochemistry assay was used to identify DNA fragmentation in situ at both light and electron microscopic levels, whereas characteristic internucleosomal DNA fragmentation of apoptosis was demonstrated by DNA gel electrophoresis. RESULTS: Using TUNEL method, we detected massive cells with extensive DNA fragmentation in different regions of the brains of rats subjected to experimental traumatic brain injury. Compared with the sham controls, in the injured cortex, the apoptotic cells were detectable for up to 24 h and reached a peak at 1 week after injury. The number of apoptotic cells in the white matter h ad a significant increase as early as 12 h after injury and peaked at 1 wee k. The number of apoptotic cells increased in the hippocampus at 72 h, whereas i n the thalamus, the peak of apoptotic cells was at 2 weeks after injury. The number of apoptotic cells in most regions returned to sham values 2 months after in jury. Gel electrophoresis of DNA extracted from affected areas of the injured br ain revealed only internucleosomal fragmentation at 185-bp intervals, a feature originally described in apoptotic cell death. And no DNA ladder was detectable in the cortex and hippocampus contralateral to the injured hemisphere. CONCLUSIONS: These data suggest that in addition to the well described necrotic cell death, a temporal course of apoptotic cell death is initiated after brain trauma in selected brain regions.

Analysis of Variance↗