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Biomedical subjects

Min Zhao

Publications and source records attributed to Min Zhao.

At least 91 records · Page 5Linked to original sources
PubMed2004

[Inhibition of malignant ascites with endostatin adenoviral vector].

OBJECTIVE: To evaluate the therapeutical effect of endostatin adenoviral vector on malignant ascites and compare it with the combined effect of ad-endostatin and DDP. METHODS: We transfected SKOV3 cells with ad-endostatin to inhibit human umbilical vein endothelial cells (HUVEC) proliferation. Then we administered ad-endostatin intraperitoneally in BALB/c mice to detect the serum endostatin expression and in the mice with malignant ascites to evaluate the therapeutic efficacy. RESULTS: Recombinant endostatin inhibited HUVEC proliferation. Endostatin was expressed in serum after intraperitoneal injection of ad-endostatin. The effects of endostatin on inhibition of the ascites accumulation and peritoneal capillary permeability, on demotion of VEGF protein level and microvascular density in tumor tissues, on reduction of the number of red cells and tumor cells counted in malignant ascites, and on prolongation of mice survival were significant in two different malignant ascites. Furthermore, the combination of ad-endostatin with DDP increased the therapeutic efficacy. CONCLUSION: These data suggested that endostatin gene therapy may represent a potential new treatment for malignant ascites, and the therapeutic efficacy can be enhanced by a combination of ad-endostatin with chemotherapy.

Adenoviridae↗
PubMed2004

[Factors influencing axon regeneration after CNS damage].

In contrast to peripheral nerves, damaged axons in the mature mammalian brain and spinal cord rarely regenerate, and always lead to permanent loss of function. There are many reasons that inhibit the axon regeneration in the central nerve system, including the formation of glial scar, the deficiency of neurotrophic factors and the expression of inhibitory molecules. Here several factors, their structures, distributions, contributions and possible mechanisms are briefly reviewed.

Animals↗
PubMed2004

[Microsatellite instability and loss of heterozygosity of human leucocyte antigen class I gene in cervical carcinoma].

OBJECTIVE: To investigate the frequency of microsatellite instability (MSI) and loss of heterozygosity (LOH) at human leucocyte antigen(HLA) class I loci in cervical carcinoma and the detailed deletion mapping in this region. METHODS: LOH and MSI of HLA class I genes were analyzed in 30 paired blood and tumor samples by PCR based single-stranded length polymorphism (PCR-SSLP). RESULTS: Of the 30 cases, 23(76.7%) showed LOH at one or more loci. Higher frequencies of LOH were found at four loci: C3_2_11 (50%), C1_4_4 (37%), C1_2_5 (36.7%), D6S276 (48.3%). MSI was found in 20 out of 30 cases (66.7%). CONCLUSION: The data suggest that the LOH and MSI of HLA class I gene might participate in the carcinogenesis of cervical carcinoma. Meanwhile, the minimal deletion region might be defined between C1_2_5 and C3_2_11, thus providing the evidence for cloning the tumor suppressor genes associated with cervical carcinoma.

Adult↗
PubMed2004

[The early warning signs of deterioration of severe acute respiratory syndrome].

OBJECTIVE: To explore the risk factors related to severe cases of severe acute respiratory syndrome (SARS) in order to find the early warning signs of deterioration of this disease. METHODS: Three hundred and fifty-five patients with severe SARS and 841 patients with regular SARS from Beijing were studied. RESULTS: Patients with elder age or with comorbid conditions were more likely to develop into severe cases. Data also showed the following characteristics in those severe cases: sustained fever, tachycardia (pulse rate being over 100 per minute), persistent decrease in lymphocytes (< 0.9 x 10(9)/L), increase in neutrophils (> 7.1 x 10(9)/L, 80%), and rapid changes in abnormal chest X-ray. The Cox proportional hazard multi-variable stepwise analysis showed the prediction model of severe SARS included age, comorbid disease, body temperature being still abnormal after 2 days of hospitalization, neutrophil percentage began to increase steadily to more than 80% after 3 days of hospitalization, counts of lymphocytes persisted < 0.9 x 10(9)/L after 4 days of hospitalization. CONCLUSIONS: According to patient's age, comorbid conditions, one can effectively predict the development of the severe SARS by closely monitoring temperature, pulse rate, the counts of lymphocytes and percent of neutrophils.

Adult↗
PubMed2004

Effects of glycine and methylprednisolone on hemorrhagic shock in rats.

BACKGROUND: Methylprednisolone (MP), a synthetic glucocorticosteroid, has been broadly studied in experiments on endotoxin-induced shock and septic shock. This study was designed to ascertain whether glycine and MP can protect against organ injury and death caused by hemorrhagic shock, and to elucidate the underlying mechanisms of these protective effects in rats. METHOD: To establish a shock model, Wistar rats were bled to maintain mean arterial pressure at 30-50 mmHg for 1 hour and subsequently resuscitated with the shed blood and normal saline. Just prior to resuscitation, the rats were randomly assigned to four groups: sham group (operation performed without inducing shock), shock group, shock + glycine group (glycine injected at the beginning of resuscitation) and shock + MP group (MP injected at the beginning of resuscitation). RESULTS: (1) Seventy-two hours after resuscitation, the survival rate of rats from the shock group had decreased to 20%, while the survival rates of rats from the shock + glycine and shock + MP groups were 77.8% and 80%, respectively. The difference was significant (P <0.05). (2) Eighteen hours after resuscitation, pathological alterations in the organs of the rats were apparent. In rats from the shock group, edema, interstitial leukocyte infiltration, and cellular degeneration occurred in the liver, lungs, kidneys, and heart. Glycine and MP reduced these pathological changes significantly. (3) Eighteen hours after resuscitation, the levels of creatine phosphokinase, transaminases, and creatine were elevated significantly in rats from the shock group, indicating injury to the heart, liver, and kidneys, while these levels were elevated only slightly in the shock + glycine and shock + MP groups. The differences were significant (P <0.01). (4) There were significant increases in intracellular calcium and production of tumor necrosis factor (TNF-alpha) by isolated Kupffer cells stimulated by endotoxin after hemorrhagic shock. These changes were completely prevented by glycine and MP (P <0.01). CONCLUSION: Glycine and MP reduce organ injury and mortality caused by hemorrhagic shock by preventing increase of intracellular calcium levels in Kupffer cell, suppressing Kupffer cell activation, decreasing the production of TNF-alpha by Kupffer cells, and blocking systemic inflammatory responses.

Animals↗
PubMed2004

[The usage of inferior turbinate mucosal flap for repairing cleft lip].

OBJECTIVE: To evaluate a technique for decreasing the tension of the nasal floor during the procedures of repairing complete clef lip. METHODS: With the designation of an inferior turbinate mucosal flap combined with an oral mucosal flap in the splitting side, the tension was effectively decreased and the nasal floor was closed easily. Eighteen patients was selected for the treatment with this technique since 2000. The follow-ups were 10 to 24 months. RESULTS: All of the patients showed wound healing well with the significant improvement in the donor site. CONCLUSION: The above mentioned technique may effectively decrease the tension and be used to close the nasal floor safely. It could also reduce the incidence of the complications.

Cleft Lip↗
PubMed2004

[The investigation of behavior problem with secondary deformity of cleft lip].

OBJECTIVE: To investigate the behaviors of the children suffered from the secondary deformity after the repair of the cleft lip. METHODS: With the application of the PCPI, eighty patients with the secondary deformity after the repair of the cleft lip were selected in this study and 134 normal children was used for the control. RESULTS: In the age between 6 and 11 years, there were no significant difference of the behaviors between the children suffered from secondary deformity of cleft lip and the normal children,but in the age from 12 to 16, the children with the deformity showed more behavior problems with the social withdraw and the poor social relationships, compared with the normal children. CONCLUSION: The children with the secondary deformity after cleft lip repair in adolescence could have the tendency to suffer from the behavior problems, especially showing the social withdraw and the poor social relationships.

Adolescent↗
PubMed2004

[Forest Inventory Data (FID)-based biomass models and their prospects].

Forest Inventory Data (FID)-based biomass models are important methods in assessing forest biomass at landscape, regional, and national scales, and play an important role in studying terrestrial carbon budget and global changes. In this paper, Forest Inventory Data were reviewed, FID-based models were summarized, and shortages of FID-based models were analyzed. Based on these analyses, the future tasks were pointed out: 1) Comprehensive effect of forest biological factors and non-biological factors on forest biomass, especially on forest volume and age; 2) Identification of the relationships between total forest biomass and live wood biomass; 3) Development of remote sensing- and FID-based forest biomass models. These researches will provide new methods and theoretical bases for estimating forest biomass and carbon budget.

Biomass↗
PubMed2004

[Genotype of extended-spectrum beta-lactamases produced by antibiotic-resistant Escherichia coli and Klebsiella pneumoniae in surgical intensive care unit].

OBJECTIVE: To describe the antibiotic resistant mode of extended-spectrum beta-lactamases(ESBLs) producing Escherichia coli (E. coli.) and Klebsiella pneumoniae (KPn) in surgical intensive care unit(SICU), and to implore the molecular epidemiology of ESBLs coding genes of these strains. METHODS: The minimal inhibitory concentrations (MICs) at antibiotics were examined by agar dilution method. The ESBLs coding genes were amplified by TEM, SHV and CTX-M specific primers. Amplicons of such genes with conjugates' plasmids as templates were sequenced. RESULTS: In vitro susceptibility tests of ESBLs producing strains showed a high level of resistance to most of the beta-lactam biotics, especially cefotaxime. 93.5% of these ESBLs positive strains contained CTX-M group genes,and 38.7% of the strains contained SHV genes. By sequencing, some genotype were determined: TEM-1, CTX-M-1,3,14,22. CONCLUSION: ESBLs producing strains were resistant to most of the beta-lactam biotics. The most prevalent ESBLs genotype of ESBLs produced by E coli and KPn in SICU was CTX-M subgroup. The most probable reason might be the extensive use of cefotaxime.

Anti-Bacterial Agents↗
PubMed2004

[Surgical treatment of transcranial middle cranial fossa-lateral skull base malignant tumor].

OBJECTIVE: To evaluate the surgical method of transcranial middle cranial fossa-lateral skull base malignant tumor. METHODS: Sixteen patients with transcranial middle cranial fossa-lateral skull base malignant tumors were treated by three surgical methods. (1) Postauricular "C" form incision, combined with subtotal resection of temporal bone and high lateral neck approach to resect tumors located in middle cranial fossa, lateral skull base, and parotid region. (2) Temporal side "tungue" form incision, middle cranial fossa approach to resect tumors inside and outside the skull. (3) Temporal-auricular-mandible swing approach to resect tumors in parapharyngeal-infratemporal fossa-middle cranial fossa. Thirteen of the 16 cases received radiotherapy postoperatively. RESULTS: After operation, 11 of the 16 cases survived more than three years, five cases died within three years. Three-year-survival rate was 69%. CONCLUSIONS: Our results showed that the three surgical methods adopted could fully expose the internal and external skull lesion to remove the extensive malignant tumors. For late stage malignant tumors of the skull base, it should be treated aggressively by combination of surgical therapy and postoperative radiotherapy.

Adult↗
PubMed2004

[Leptin as a survival enhanced-factor in grainy fat transplantation].

OBJECTIVE: This experiment is to test the survival enhance effect of leptin in grainy fat transplantation. METHODS: The 0.6 g grainy fat was obtained from the Wistar mouse subcutaneous tissue in the abdomen. It was then mixed with 0.9% NS and 20 ng/ml leptin and transplanted in the head subcutaneously. The transplanted tissue was taken out after 10, 20 and 40 days. After being weighed, the tissue was dyed with HE staining and VEGF staining. The data was analyzed with SPSS software. RESULTS: The fibrous membrane around the tissue in leptin group was thin and there was less fat cell necrosis, compared with the control group. The remained-weight rate was 108.3%, 83.3% and 66.3% in 10, 20 and 40 days after the surgery. The differences were statistic significant between the leptin groups and the control (P < 0.05). The examinations of the HE and VEGF stain showed that there was the rich vascularization in leptin treated tissue. CONCLUSION: Leptin could enhance the survival of the transplanted grainy fat due to its angiogenesis effect.

Adipose Tissue↗
PubMed2003

Electrical stimulation directly induces pre-angiogenic responses in vascular endothelial cells by signaling through VEGF receptors.

Controlling angiogenesis is crucial. Growth factors and cytokines are key regulators but a full understanding remains elusive. Endogenous electrical potential differences exist within and around the vasculature, both in relation to blood flow and in situations where active angiogenesis occurs, such as wound healing, development and tumor growth. Recent work shows that electrical stimulation induces significant angiogenesis in vivo, through enhanced vascular endothelial growth factor (VEGF) production by muscle cells. We report that applied electric fields (EFs) of small physiological magnitude directly stimulate VEGF production by endothelial cells in culture without the presence of any other cell type. EFs as low as 75-100 mV mm-1 (1.5-2.0 mV across an endothelial cell) directed the reorientation, elongation and migration of endothelial cells in culture. These pre-angiogenic responses required VEGF receptor activation and were mediated through PI3K-Akt and Rho-ROCK signaling pathways, resulting in reorganization of the actin cytoskeleton. This indicates that endogenous EFs might play a role in angiogenesis in vivo by stimulating the VEGF receptor signaling pathway, to induce key pre-angiogenic responses. In addition, it raises the feasibility of using applied EFs to initiate and guide angiogenesis through direct effects on endothelial cells.

Acute-Phase Proteins↗
PubMed2003

HIV-1 subtype B' dictates the AIDS epidemic among paid blood donors in the Henan and Hubei provinces of China.

OBJECTIVE: To investigate the genetic background of HIV-1 strains among infected paid blood donors (PBD) in the Henan and Hubei provinces of China. METHODS: The polymerase chain reaction was used to amplify HIV-1 gag p17 fragments and some 5'-half or full-length viral genomes from peripheral blood mononuclear cells. The HIV-1 sequences obtained were analysed using phylogenetic and recombinant approaches. RESULTS: Among the total of 62 samples studied, 59 (95.2%) came from PBD. Of those 59 PBD, 45 were collected from 14 different geographical locations in Henan, whereas the remaining 14 were from five locations in Hubei. A total of 62 HIV-1 gag p17 fragments, three 5'-half and one full HIV-1 genome sequences were obtained. Phylogenetic analysis of these sequences suggests that PBD from Henan and Hubei, despite being geographically distant, harbored a group of genetically closely related HIV-1 B' strains. No recombinant forms have been detected in this cohort. CONCLUSION: Our data indicate that the AIDS epidemic among PBD in Henan and Hubei is caused largely by HIV-1 subtype B', which contrasts greatly with the CB' recombinant strains CRF-07 and CRF-08 currently dominating among the drug abusers in other regions of China. Our report has revealed the first complete genome background of the most dominant circulating HIV-1 strain in Henan and Hubei, which is essential for the design and development of an effective AIDS vaccine for the region.

Acquired Immunodeficiency Syndrome↗
PubMed2003

Serial determination of glomerular filtration rate in conscious mice using FITC-inulin clearance.

Two nonradioactive methods for determining glomerular filtration rate (GFR) in conscious mice using FITC-labeled inulin (FITC-inulin) were evaluated. The first method measured GFR using clearance kinetics of plasma FITC-inulin after a single bolus injection. Based on a two-compartment model, estimated GFR was 236.69 +/- 16.55 and 140.20 +/- 22.27 microl/min in male and female C57BL/6J mice, respectively. Total or (5/6) nephrectomy reduced inulin clearance to 0 or 32.80 +/- 9.32 microl/min, respectively. Conversely, diabetes mellitus induced by streptozotocin was associated with increased GFR. The other approach measured urinary inulin clearance using intraperitoneal microosmotic pumps to deliver FITC-inulin and metabolic cages to collect timed urine samples. This approach yielded similar GFR values of 211.11 +/- 26.56 and 157.36 +/- 20.02 microl/min in male and female mice, respectively. These studies demonstrate the feasibility of repeated nonisotopic measurement of inulin clearance in conscious mice.

Animals↗
PubMed2003

[Frequent 4 977 bp deletion of mitochondrial DNA in tumor cell lines, solid tumors and precancerous lesions of human stomach].

OBJECTIVE: To clarify the frequency of mtDNA 4 977 bp deletion in tumor cell lines, solid tumors, patient's serum of gastric tumor and to find a easy and exact method to diagnose gastric tumor. METHODS: Primer-shift PCR method was used in 13 gastric tumor cell lines, 52 cases of gastric fresh tumor tissues matched the adjacent normal tissues, 40 cases of patient's serum of gastric tumor and 40 cases of normal serums for analysis of mtDNA deletion. RESULTS: Frequency of 4 977 bp mtDNA deletion was detected in 12 of 13 (92.3%) tumor cell lines, 38 of 52 (73.1%) cases of solid tumor tissues, 27 of 52 (52%) adjacent normal tissues, 17 of 40 (42.5%) patient's serum and 8 of 40 (20%) normal serums. Further more, in 2 of 10 pairs microdissected specimens, we found this deletion occurred not only in primary tumor but also in intestinal metaplasia comparing with no deletion was found in normal tissues. The frequency of this deletion was statistically significantly higher in the gastric tumor tissues and serums than in the adjacent normal tissues and serums. A good correlation between the deletion and young age of patients was representative in our data. CONCLUSION: mtDNA 4 977 bp deletion maybe play an important role in the carcinogenesis of human gastric mucous and maybe has happened in the tumor cell malignant transformation. To detect this deletion in patient's serum is a easy and exact method and maybe become a potential tumor marker.

Adenocarcinoma↗
PubMed2003

[Epidemiologic features, clinical diagnosis and therapy of first cluster of patients with severe acute respiratory syndrome in Beijing area].

OBJECTIVE: Investigate the features of outbreak epidemic, clinical disease progression of the first SARS cases in Beijing and evaluate the efficacy of therapeutic regimen. METHODS: Twenty-nine patients (11 men and 18 women, 20 - 74 years old age range) were diagnosed with infectious SARS and admitted in our hospital from the March 5th to April 14th, 2003 in this study. The data of clinical presentation and disease progression of all the patients including index subject as the infectious SARS resource patient, her family infected members and 21 health care workers were abstracted. RESULTS: The first SARA outbreak in Beijing was characterized with the cluster feature of resource patient family members and health care providers. The incubation period ranged from 2 to 14 days. All the patients had a fever (temperature > 38 degrees C for over 24 hours) and other manifestations as reported before. Serial chest radiographs showed progressive pathologic air-space disease. Twenty patients showed the severe syndrome with various time ranged from 1 day to 14 days. Two patients died of progressive acute respiratory distress disease. The histologic analysis of one death patient showed diffuse alveolar damage in the two lungs. Twenty-six patients receiving the combined therapy including use of corticosteroid, antiviral ribavirin agents after the onset of symptoms and showed they had an acute self-limited disease course. The oldest patient (74 year old, male) received the healthy convalescent plasma infusion (50 ml) from recovered SARS subject and completely recovered within 21 days, having a shorter disease course. CONCLUSION: SARS is a kind of new self-limited and acute infectious disease. Early diagnosis, early isolation, early antiviral therapy for patients and efficient prevention for health care providers are urgently recommended. In particular, a combinational therapy of use of antiviral agents, preventive antibacterial antibiotics and pulsed dosage of corticosteroid can efficiently raise the clinical recovery rate and decrease mortality of SARS patients.

Adult↗
PubMed2003

Solution to the problem of interferences in electrochemical sensors using the fill-and-flow channel biosensor.

A generic fill-and-flow channel biosensor with upstream electrodes to determine the extent of interferences in the sample is described. A pair of upstream electrodes poised at a suitable potential allows both the calculation of the extent of removal of interfering agents and the effect of interfering agents at the detector electrode. A model was developed and tested that predicts the concentrations of all species throughout the channel and, hence, the current at each electrode due to each species. This enables correction of the detector electrode current and a more accurate determination of the analyte concentration. The concept was applied to a biosensor for the determination of glucose in the presence of ascorbic acid, acetamidophenol, and uric acid, as well as glucose in wine samples containing polyphenolic interfering agents.

Ascorbic Acid↗