Biomedical subjects

S Zhang

Publications and source records attributed to S Zhang.

At least 397 records · Page 22Linked to original sources

PubMed2000

[Effect of temperature and body weight on carbon budget of Penaeus chinensis].

The carbon budget of Penaeus chinensis feeding on polychaet worm(Neanthes japonica) was determined at various levels of temperature (20 degrees C, 25 degrees C, 30 degrees C) and body weights(0.271 +/- 0.041 g, 3.509 +/- 0.301 g, 11.062 +/- 1.027 g) from May to September, 1996. The results show that the carbon consumption was significantly affected by water temperature and body weight, which significantly increased with increasing temperature and decreasing body weight. The average carbon consumptions at 20 degrees C, 25 degrees C and 30 degrees C were 12.41, 19.12 and 26.08 mg.g-1.d-1, and those for 3 body weights were 36.06, 12.17 and 9.38 mg.g-1.d-1, respectively. The intake carbon allocation was not significantly affected by body weight, but significantly affected by water temperature. The proportions of carbon allocated to growth, fecal, exuviation and metabolism at three different temperatures were 31.23%, 4.28%, 7.94%, 56.45%; 26.83%, 2.92%, 6.69%, 65.79%; 16.86%, 2.38%, 5.99%, 74.76%, respectively.

Animals↗

PubMed2000

[The current status of the study on asthma in China].

PURPOSE: To review the recent developments in asthma research in China, presenting the background of further asthma research and promoting academic exchanges between Chinese and foreign respirologists. DATA SOURCES: A literature search was conducted using 5 authoritative journals covering the years 1994-1998. STUDY SELECTION: Sixty-seven of 238 asthma-remated original articles published between the years 1994-1998 were selected to reflect the recent developments in asthma in China. DATA EXTRACTION: The papers reviewed pertain mainly to the epidemiology, genetics, pathogenesis, prevention and treatment of asthma. RESULTS: Since 1993, the hot topics in asthma research in China have been pathogenesis, prevention and treatment. There has been relatively less investigation into the genetics of asthma in China. An epidemiological survey of asthma has been conducted in parts of China and was reviewed. CONCLUSIONS: More and more attention has been paid to the study of asthma during the last five years in China. The prevalence of asthma has increased in recent years. The study of the pathogenesis of asthmatic airway inflammation has made further progress, which will help the management and treatment of asthma. The treatments for asthma, including herbal medicine, have been explored and the clinical efficacy of inhaled corticosteroids has been established.

Apoptosis↗

PubMed2000

The cellular and molecular mechanism of laminin-glycopeptides on anti-metastasis.

OBJECTIVE: To further study the anti-metastasis mechanism of laminin-glycopeptides on carcinoma cell proliferation, apoptosis and the secretion of matrix metalloproteinases. METHODS: Human hepatocellular carcinoma cells in serum free medium were incubated on laminin-coated substrate with or without laminin-glycopeptides at a final concentration of 50 micrograms/ml. The total number of surviving cells after incubating for the indicated time was assayed by MTT assay. DNA synthesis of the incubated cells was detected by 3H-TdR incorporation. Cell cycle was analysed by FACS. The mitotic index of Giemsa stained cells was assessed. Cell apoptosis was detected by both FACS and an acridine orange staining method. Matrix metalloproteinase secretion was analysed by gelatin zymography. RESULTS: The total number of surviving cells incubated on laminin in the absence of laminin-glycopeptides was significantly larger than that in the presence of laminin-glycopeptides. Laminin promoted 3H-TdR incorporation of carcinoma cells, decreased the percentage of cells in G1 phase and increased the percentage of cells in S phase. In contrast, laminin-glycopeptides could inhibit the effect of laminin as shown by 3H-TdR incorporation and cell cycle analysis. The percentage of cells in G2 + M phase and the mitotic index among various groups showed no significant difference. Matrix metalloproteinases secretion from cells treated by laminin-glycopeptides was much less compared to that without the treatment by laminin-glycopeptides. CONCLUSION: Laminin may stimulate cell proliferation, while laminin-glycopeptides could significantly inhibit the effect of laminin by inhibiting DNA synthesis and arresting the carcinoma cell cycle from G1 to S phase. These effects may inhibit not only tumor growth of the primary carcinoma, but also the establishment of metastases at ectopic tissues. Laminin-glycopeptides could also inhibit the secretion of matrix metalloproteinases from carcinoma cells and this may contribute to their decreased invasive and metastatic phenotype. This study further revealed the cellular and molecular mechanism of laminin-glycopeptides on anti-metastasis.

Apoptosis↗

PubMed2000

Clinical significance of changes in beta-adrenoreceptors in peripheral lymphocytes in patients with essential hypertension.

OBJECTIVE: To explore the relationship of beta-adrenoreceptor density and function with the condition of patients with essential hypertension. METHODS: In the present study, 69 male patients with essential hypertension at different stages were compared with a group of age-matched normotensive controls. beta-adrenoreceptor maximum bound volume (Bmax) in peripheral lymphocytes was measured by 3H-dihydroalprenolol (3 H-DHA) radio ligand binding. beta-adrenoreceptor responsiveness was determined by Salbutamol (injection). RESULTS: In patients with essential hypertension at stages I and II, Bmax was significantly higher (P < 0.01 and P < 0.001, respectively) and the chronotropic doses of Salbutamol required to increase the heart rate by 30 beats/min (CD30) were significantly lower (P < 0.01 and P < 0.001, respectively) than in age-matched normotensive control subjects. In patients with essential hypertension at stage III, Bmax was significantly lower and CD30 was significantly higher (both P < 0.01) than those in the age-matched normotensive control subjects. Bmax was significantly higher and CD30 was significantly lower (both P < 0.001) in patients with essential hypertension and with left ventricular hypertrophy (LVH) than that in patients with essential hypertension but without LVH. In patients with essential hypertension and heart failure, Bmax was significantly lower and CD30 was significantly higher (both P < 0.001) than those in patients with essential hypertension without heart failure. CONCLUSIONS: The changes of beta-adrenoreceptor density and function were related to hypertension, hypertension complicated with ventricular hypertrophy, and heart failure. They may be viewed as indexes of the condition in the patients with essential hypertension.

Adrenergic beta-Agonists↗

PubMed2000

Sequence variations of the hypervariable region of hepatitis C virus and their clinical significance.

OBJECTIVE: To understand the clinical significance of sequence variations in the hypervariable region (HVR) of hepatitis C virus during infection. METHODS: Eight patients with acute hepatitis C and 20 patients with chronic hepatitis C were followed up for two years. Blood samples were taken at intervals of six months for analysis of HCV-HVR sequences by reverse transcription-polymerase chain reaction (RT-PCR) and direct sequencing methods. RESULTS: HCV-HVR sequences of the 28 patients changed in various degrees. 92% of these nucleotide substitutions led to changes of corresponding aminoacid sequences. Only 8% of changed nucleotide were synonymous substitutions. Of 27 amino acids variation of amino acid ranged from 1 to 20 (mean 8, 30%). The most common nucleotide substitution (62%) occurred in the first position of codon, 31% in the second and the rest in the third. HVR variation rate was 0.89 x 10(-1) per genome site per year in acute hepatitis C, compared with 2.31 x 10(-1) per genome site per year in chronic hepatitis C (P < 0.05), but had no relation to HCV subtype. Variation of HVR in the flare up type (ALT > 150 mu/L) was much more than that in the quiescent type (ALT < 100 mu/L). CONCLUSION: Our results suggested that sequence variation of HVR during HCV chronic infection seems to be an adaptive response to HCV to evade the host immune pressure and might play a major role in the establishment of persistent infection as well as in the flare-up of hepatitis.

Acute Disease↗

PubMed2000

[The efficacy and safety of domestic luteinizing hormone-releasing hormone analogue and low-dose norethindrone "add-back" therapy in the treatment of endometriosis].

OBJECTIVE: To study the efficacy and safety of combining domestic luteinizing hormone-releasing hormone analogue(LHRH-a) with low-dose norethindrone in the treatment of endometriosis. METHODS: Seventy-seven women with endometriosis were randomized into one of the following two groups. Group A (n = 36) were treated with LHRH-a (150 micrograms/d, i.m.) plus norethindrone (2.5 mg/d, p.o.) and group B (n = 41) received only LHRH-a (150 micrograms/d, i.m.) for 3 to 6 months. Symptoms and signs were recorded before and after the treatment. Liver and renal functions, lipid and bone metabolism and speed of sound (SOS) in the tibia were also examined at the same time. All data were analyzed using paired and grouped Student's t-tests. RESULTS: Total subjective symptom scores of group A showed 82% decrease at 3 months and 94% at 6 months of treatment (P < 0.01). Reductions in endometriotic foci were 34% and 61% at 3 and 6 months, respectively (P < 0.01). Of group B, there were 77% and 90% decreases in total subjective symptom scores at 3 and 6 months of treatment (P < 0.01). Reductions of 37% and 38% in endometriotic foci were observed at 3 and 6 months, respectively (P < 0.01). Liver and renal functions and fast blood sugar of both groups were all in normal range. Triglyceride (TG), apolipoproteinA (ApoA), serum calcium, phosphorus and alkaline phosphatase levels of group B increased significantly after treatment. And significant differences between the two groups were observed. There's no change of SOS in the tibia within or between the two groups before and after treatment. The percentages of hemorrhage in the group A and B were 18% and 38%, respectively. The percentages of hot flush and the other vasomotor symptoms were 14% and 41%, respectively (P < 0.01). CONCLUSIONS: Domestic LHRH-a combined with low-dose norethindrone was effective in the treatment of endometriosis. It could also improve the symptom of hypoestrogenemia, decrease hemorrhage rete and bone turn-over.

Adult↗

PubMed2000

[Preliminary clinical observation on treatment of chronic rhinitis with rhinitis spray].

OBJECTIVE: To investigate the clinical effect of Rhinitis Spray (RS) in treating chronic rhinitis. METHODS: Eighty patients with chronic rhinitis were divided into three groups, and treated with RS, ephedrine and normal saline respectively. RESULTS: The short-term effective rate in the three groups was 89.3%, 66.7% and 8.0% respectively. RS was effective in alleviating symptoms, increasing IgG level in nasal discharge, improving ventilation of nasal cavity and transfer function of cilia of nasal mucosa obviously. CONCLUSION: The therapeutic effect of RS in treating chronic rhinitis is good.

Administration, Inhalation↗

PubMed2000

[Experimental study of analgesic effect of combined Radix Aconiti and Radix Stephaniae Tetrandrae].

OBJECTIVE: To explore the changes of analgesic effect of combined Radix Aconiti (RA) and Radix Stephaniae Tetrandrae (RST). METHODS: Randomly divide the rabbits and mice into following groups: the blank control group, the positive control group, the RA group, the RST group, the combined RA:RST(1:1) group, the combined RA:RST(1:2) group. Then, using chemical, heat and electrical stimuli, four kinds of pain models were produced, which were to observe the changes of pain threshold of mice before and after using combined RA and RST therapy. RESULTS: Remarkable analgesic effect was obtained in the positive control group and all the groups treated with these two herbs within 3 hours (P < 0.01), and the effect was more obvious in the combined RA-RST groups and the RA group. The analgesic effect of the positive control group, the RST and the RA group weakened gradually 3 hours later, and at the 24th hour, the effect disappeared in the positive control group and the RST group but it is still remarkable in the combined RA-RST group, which has a significant difference from the positive control group and the groups treated with one single herb (RA or RST). CONCLUSION: The analgesic effect of the combined RA-RST is superior to the RA and the RST used alone.

Analgesics, Non-Narcotic↗

PubMed2000

[Experimental study on human pancreatic carcinoma treated by cytosine deaminase gene therapy].

OBJECTIVE: To explore the possibility of Escherichia coli cytosine deaminase (CD) gene on human pancreatic carcinoma gene therapy. METHODS: Recombinant adenoviruses containing a carcinoembryonic antigen (CEA) promoter were transiently introduced into SW1990, Capan-2 and Hela cells, separately. The expression of CD gene mRNA was examined by RT-PCR. CD protein level in the transduced cells was analyzed by Western blotting. The sensitivity of the cells to 5-fluorocytosine (5-FC) was determined by MTT assay. RESULTS: A specific expression of cytosine deaminase gene by adenovirus-mediated transfer exhibited only in SW1990 cells (CEA-producing). Transduction of CD gene resulted in significant sensitivity of SW1990 cells to 5-FC. The anticancer effect was seen in vivo in SW1990 xenografts nude mice with in situ CD gene transduction. CONCLUSION: The targeted expression of CD gene combined prodrug 5-FC may be a potential approach for gene therapy for human pancreatic carcinoma.

Adenocarcinoma↗

PubMed2000

[Multicenter evaluation of the antimicrobial activity in vitro for six broad-spectrum beta-lactams in China using the E-test method].

OBJECTIVE: To investigate the in vitro activities of cefepime and other 5 beta-lactam antimicrobial agents against 937 strains isolated from 10 teaching hospitals in different geographical areas in China during the early 1998. METHODS: The MIC values of cefepime, ceftazidime, ceftriaxone, imipenem, cefoperazone/sulbactum, and piperacillin against 937 isolates were tested by a gradient concentration method (E-test((R)); AB Biodisk Co.). RESULTS: Quality control isolates were tested in all working processes. MIC values of 96.5% (829/859 times) of quality assurance tests were within expected ranges of NCCLS. Only imipenem and cefepime could inhibit 90% of enterobacter and citrobacter strains, Cefepime were significantly more active than 3rd Generation cephalosporins in enterobacter and citrobacter strains, and little better active than E. coli and Klebsiella spp. (98%, 95% susceptibility). All tested antimicrobial excluding ceftazidime had very high activity to oxacillin susceptible Staphylococci (95% approximately 100% susceptibility). cefepime, ceftazidime, imipenem, and cefoperazone/sulbactum had similar activity to Pseudomonas aeruginosa (83% approximately 79% susceptibility). Both imipenem and cefoperazone/ sulbactum were very active to Acinetobacter spp. (97%, 89% susceptibility). CONCLUSION: The rank order of activity of the six tested agents is imipenem (97% Susceptible) > cefepime (89%) > cefoperazone/sulbactum (86%) > ceftazidime (76%) > ceftraixone (67%) > piperacillin (57%). The data are helpful to guide empiric therapy with beta-lactams in China.

Anti-Bacterial Agents↗

PubMed2000

[Diagnosis and treatment of early colorectal cancer].

OBJECTIVES: To study the diagnostic methods of early colorectal neoplasm before operation and to evaluate the value of these methods for selection. METHODS: Fifteen patients with early colorectal neoplasms were examined pre-operatively by general colonoscopy to observe macroscopic appearance, by magnifying endoscopy to classify pit pattern type, and by endoscopic ultrasonography (EUS) to assess the penetrating depth of cancer invasion as well as regional lymph node metastases. According to these findings, diagnosis and clinical staging were made and proper treatment protocols were established. RESULTS: The diameter of the tumors ranged from 1 to 6 cm. Most lesions were subpedunculate type (8/15, 53%). Eight cases belonged to pit pattern type III L + V (8/15, 53%). EUS showed mucosal cancer in 11 cases and submucosal cancer in 4. No lymph node metastasis was observed in any cases. Treatment methods included endoscopic polypectomy or endoscopic mucosa resection (EMR) in 6 cases, endo-surgery combined with open surgery in 2, and open surgery in 7. Pathological diagnosis showed mucosal carcinoma in 12 cases, submucosal carcinoma in 3. The accuracy of EUS was 93%. CONCLUSIONS: Magnifying endoscopy and EUS are useful for diagnosis of early colorectal cancer before operation, and correct preoperative staging of colorectal neoplasms is of significance in guiding treatment.

Colonoscopy↗

PubMed2000

[Detection of K-ras gene mutations in DNA extracted from the plasma of patients with pancreatic cancer].

OBJECTIVES: To detect mutations of the K-ras codon 12 in DNA extracted from the plasma of patients with pancreatic cancer, and to explore the possibility of using this method in early diagnosis of pancreatic cancer. METHODS: Plasma DNA was isolated from the blood of 22 patients with pancreatic cancer and from 20 normal controls. K-ras codon 12 mutations were detected by mutant enriched polymerase chain reaction-restriction fragment length polymorphism technique and subsequent product sequencing. The relation of K-ras mutations in plasma to clinical features in pancreatic cancer patients was analyzed. RESULTS: Seventeen (77.3%) of 22 patients with pancreatic cancer had a codon 12 K-ras mutation in their plasma DNA. In two patients, the PCR products were sequenced and the mutations were confirmed. The occurrence of K-ras mutations in the plasma DNA was not related to tumor location, tumor size, and TNM stage. No K-ras mutation was detected in the plasma specimen of any of the normal controls. CONCLUSIONS: K-ras mutations are frequently found in the plasma DNA of patients with pancreatic cancer. Analysis of K-ras mutation in the plasma DNA may be useful in the early detection of pancreatic cancer.

Adult↗

PubMed2000

[CT guided percutaneous fine needle aspiration for early diagnosis of pancreatic infection after acute necrotizing pancreatitis].

OBJECTIVE: To assess CT-guided percutaneous fine needle aspiration (FNA) for early diagnosis of pancreatic infection after acute necrotizing pancreatitis. METHODS: CT-guided percutaneous FNA was employed to diagnose pancreatic infection after acute necrotizing pancreatitis in 14 patients. The aspirates were smeared, cultured and subjected polymerase to chain reaction (PCR) for detecting bacteria. RESULTS: Ten patients were diagnosed as having pancreatic infection and 4 non-pancreatic infection. FNA was totally performed for 15 times: left retroperitoneal route for 12 times, left and right retroperitoneal route for one time, and transperitoneal route for two times. The sensitivity of smear, PCR, culture to diagnose pancreatic infection was 7/10, 9/10, 10/10, respectively. Their specificity was 4/4, and the time for obtaining the results was 30 minutes, 4 hours, 3 days respectively. CONCLUSIONS: Retroperitoneal approach can be used for most patients with acute necrotizing pancreatitis when performing CT guided-percutaneous FNA. PCR of aspirates is a rapid and accurate method to diagnose pancreatic infection.

Adult↗

PubMed2000

[Modified sternal turnover with pedicle of abdominal rectus muscle for pectus excavatum].

OBJECTIVE: To assess surgical correction for children with pectus excavatum. METHOD: Modified sternal turnover operation with rectus abdominalis pedicle was performed on 20 children with pectus excavatum since 1987. RESULTS: The patients were successfully corrected and no recurrence was seen during 6 to 36 months after operation. Human bone density examination showed same results in some patients before and six months after operation. CONCLUSION: Modified sternal turnover operation has the following advantages: easy to operate; less bleeding; better blood supply to the turned sternum; rapid postoperative recovery; satisfied correction of deformity and no recurrence. It should be widely used clinically.

Child↗

PubMed2000

[Protective effect of nitric oxide on pancreas and its relation to sulfhydryl compounds and oxygen free radicals].

OBJECTIVE: To investigate the effect of endogenous nitric oxide (NO) on acute necrosis pancreatitis in rats and its relation to sulfhydryl compounds and lipid peroxidation. METHODS: Acute necrosis pancreatitis in rats was induced by retrograde sodium taurocholate (5%) infusion into the pancreatobiliary duct (1 ml/kg body weight), and N(G)-nitro-L-arginine (L-NNA) was used as the inhibitor of endogenous NO. The effect of endogenous NO on pancreatic injury, serum amylase level, the pancreatic tissue levels of sulfhydryl compounds, and malonaldehyde (MDA, the end product of lipid peroxidation) was evaluated, respectively. RESULTS: Sodium taurocholate administration induced evident pancreatic tissue edema and acinar necrosis, and intrapancreatic hemorrhage occurred in 2/7 rats. Both serum amylase and tissue MDA [(1.25 +/- 0.28) nmol/mg x pr vs. (0.5 +/- 0.03) nmol/mg x pr, P < 0.05] were significantly increased, but tissue sulfhydryl compounds were decreased markedly. Pretreatment with the NO inhibitor, L-NNA (12.5 mg/kg body weight), significantly intensified acinar necrosis and increased the intrapancreatic hemorrhage (10/12). L-NNA also resulted in a further increase of serum amylase and tissue MDA [(3.0 +/- 0.40) vs. (1.25 +/- 0.28) nmol/mg x pr, P < 0.05], but it had no effect on the tissue sulfhydryl compounds. CONCLUSION: Endogenous NO has the effect of pancreatic protection, and its antioxidation may be responsible, at least in part, for the protective mechanisms. Sulfhydryl compounds may not be involved in NO's pancreatic protection mechanisms.

Amylases↗

PubMed2000

[Point mutations of N-ras oncogene and abnormal expression of rasp21, p53 proteins in orbital rhabdomyosarcoma].

OBJECTIVE: The point mutations of N-ras oncogene and the abnormal expression of rasp21 and p53 proteins in orbital rhabdomyosarcoma (RMS) were analyzed in order to explore the role of oncogene mutations in the pathogenesis of orbital RMS and its relation to patients' prognosis. METHOD: 21 human orbital RMS tissues were analyzed by dot-blot hybridization and immunohistochemistry using synthetic specific oligonucleotide probes and mutant rasp21, p53 monoclonal antibodies. RESULTS: The second base mutation of codon 12 of the N-ras oncogene was found in 4 patients. The third base mutation of codon 61 was found in 5 patients. The mutant rate was 33.3%. By immunohistochemistry analysis, the overexpression of rasp21 and p53 protein level was found in 42.9% and 76.2% respectively. The prognosis of patients with overexpression of ras p21, p53 was worse than that of normal expression (P < 0.01). CONCLUSION: The mutants of ras and p53 oncogene play important roles in the pathogenesis of orbital RMS, and the abnormal expression of their protein products is related to patients' prognosis.

Adolescent↗

PubMed2000

[Ultrastructure study on extraocular muscle of infiltrative exophthalmos].

OBJECTIVE: To investigate histopathologic and ultrastructural changes of extraocular muscles (EOMs) in infiltrative exophthalmos in order to collect some evidences of pathogenesis. METHODS: Ten EOM samples in infiltrative exophthalmos were obtained after operation. Each of them was cut into two pieces. One of them was stained with HE and observed by light microscope. Another one was sectioned with ultrathin method and observed by transmission electron microscope. RESULTS: Under the light microscope, the extraocular muscular cells had no significant abnormality at the early stage, while at the middle and late stage, sarcoplasm coagulation, granular degeneration, vacuolization and necrosis were found in the cells. Under the electron microscope, there were disturbance and disappearance of the Z line in part of muscular fibers in early cases; at the middle and late stage, various degrees of sarcoplasmic reticulum dilatation, myofilament lysis and destruction with formation of vacuoles, secondary lysosome and remnant bodies were seen. In severe cases, the muscular cells could be completely destroyed and phagocytosed by macrophages, fibrosis occurred and myofibroblasts were found in some cases. CONCLUSIONS: The EOMs in infiltrative exophthalmos are destroyed in various degrees, and the muscular cells may be the target cells in Graves' ophthalmopathy.

Adult↗

PubMed2000

[Ultrasound biomicroscopic examination of secondary pupillary block glaucoma].

OBJECTIVE: To study the imaging characteristics of ultrasound biomicroscopy of secondary pupillary block glaucoma. METHODS: 11 cases with pupillary block glaucoma diagnosed by ultrasound biomicroscopy were studied which had been suspected as malignant glaucoma at the beginning. RESULTS: There were no obviously typical characteristics of pupillary block glaucoma shown in the images of ultrasound biomicroscopy in these cases. However, the existence of posterior chamber in each case strongly supported the diagnosis of pupillary block glaucoma. The imaging characteristics of ultrasound biomicroscopy were different in terms of the different primary disorders which resulted in the pupillary block glaucoma including iridocyclitis, lens subluxation resulted from trauma and glaucoma filtration surgery. In the cases of lens subluxation, the main characteristic was the increase of the distance between the lens and the ciliary process at the site of subluxation and the lens forward movement. In the cases of iridocyclitis, anterior and posterior synechiae were the main characteristics. And in the cases of glaucoma filtration surgery there were two main characteristics. One was that the distance between the ciliary process and the equator of lens existed obviously, and the other was the occlusion of the inner ostium of glaucoma filtration surgery or peripheral iridectomy. CONCLUSION: Ultrasound biomicroscopy (UBM) has important value in the diagnosis of secondary pupillary block glaucoma and the differentiation between it and malignant glaucoma. Whether the posterior chamber exists or not is the differential point between the pupillary block glaucoma and the malignant glaucoma.

Adult↗