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Biomedical subjects

Z Shi

Publications and source records attributed to Z Shi.

At least 55 records · Page 3Linked to original sources
PubMed2000

ADAM 12, a disintegrin metalloprotease, interacts with insulin-like growth factor-binding protein-3.

Insulin-like growth factor-binding protein (IGFBP)-3 binds the insulin-like growth factors with high affinity and modulates their actions. Proteolytic cleavage of IGFBP-3 may regulate insulin-like growth factor bioavailability. IGFBP-3 is extensively degraded in serum during pregnancy; however, as yet the pregnancy-specific protease, or proteases, have not been identified. We utilized a yeast two-hybrid assay and a human placental cDNA library to investigate IGFBP-3-interacting proteins. A disintegrin and metalloprotease-12 (ADAM 12), a member of a family of metalloprotease disintegrins that is highly expressed in placental tissue, was identified as interacting with IGFBP-3. This interaction involved the cysteine-rich domain of ADAM 12. Unlike other members of this family of disintegrin metalloproteases that are membrane proteins, ADAM 12 exists as an alternatively spliced soluble secreted protein. To verify the interaction between ADAM 12 and IGFBP-3, an expression construct containing an ADAM 12-S cDNA was transfected into COS-1 cells. Co-precipitation was observed when conditioned medium was analyzed by immunoprecipitation with an antibody against either ADAM 12 or IGFBP-3 followed by Western blotting with anti-IGFBP-3 or anti-ADAM 12. Although minimal proteolysis of IGFBP-3 was observed in conditioned medium from control cells, this was increased approximately 4-fold in conditioned medium from ADAM 12-S-transfected cells. Recombinant ADAM 12-S partially purified from conditioned medium on a heparin-Sepharose column also proteolyzed IGFBP-3. The degradation pattern was similar to that seen with pregnancy serum, and the presence of ADAM 12-S in serum during pregnancy was confirmed. The data suggest that ADAM 12-S has IGFBP-3 protease activity, and it may contribute to the IGFBP-3 protease activity present in pregnancy serum.

ADAM Proteins↗
PubMed2000

Palladium(0)-catalyzed cyclization reaction of polymer-supported aryl iodides with 1,2-allenyl carboxylic acids. A facile solid-phase synthesis of butenolides.

[reaction--see text] Aryl iodides anchored to Merrifield resin via the linkages between a carboxyl, hydroxyl, or hydroxymethyl group and the benzylic chloride moiety in the resin reacted efficiently with 1,2-allenic carboxylic acids under the catalysis of Pd(0) to afford polymer-supported butenolides. Polysubstituted butenolides can be easily cleaved from the resins by Lewis acid-catalyzed processes in good yields and purities.

4-Butyrolactone↗
PubMed2000

Regioselective enzymatic aminoacylation of lobucavir to give an intermediate for lobucavir prodrug.

Synthesis of lobucavir prodrug, L-valine, [(1S,2R,3R)-3-(2-amino-1,6-dihydro-6-oxo-9H-purin-9-yl)-2-(hydroxymethyl) cyclobutyl]methyl ester monohydrochloride (BMS 233866), requires regioselective coupling of one of the two hydroxyl groups of lobucavir (BMS 180194) with valine. Either hydroxyl group of lobucavir could be selectively aminoacylated with valine by using enzymatic reactions. N-[(Phenylmethoxy)carbonyl]-L-valine, [(1R,2R,4S)-2-(2-amino-6-oxo-1H-purin-9-yl)-4-(hydroxymethyl)cyclobutyl]methyl ester (3, 82.5% yield), was obtained by selective hydrolysis of N,N'-bis[(phenylmethoxy)carbonyl]bis[L-valine], O,O'-[(1S,2R,3R)-3-(2-amino-6-oxo-1H-purin-9-yl)cyclobuta-1,2-diyl]methyl ester (1) with lipase M, and L-valine, [(1R,2R,4S)-2-(2-amino-1,6-dihydro-6-oxo-9H-purin-9-yl)-4-(hydroxymethyl)cyclobutyl]methyl ester monohydrochloride (4, 87% yield) was obtained by hydrolysis of bis[L-valine], O,O'-[(1S,2R,3R)-3-(2-amino-6-oxo-1H-purin-9-yl)cyclobuta-1,2-diyl]methyl ester, dihydrochloride (2), with lipase from Candida cylindracea. The final intermediate for lobucavir prodrug, N-[(phenylmethoxy)carbonyl]-L-valine, [(1S,2R,4R)-3-(2-amino-6-oxo-1H-purin-9-yl)-2-(hydroxymethyl)cyclobutyl]methyl ester (5), could be obtained by transesterification of lobucavir using ChiroCLEC BL (61% yield), or more selectively by using immobilized lipase from Pseudomonas cepacia (84% yield).

Acylation↗
PubMed2000

Seasonal abundance of the parasitoid complex associated with the diamondback moth, Plutella xylostella (Lepidoptera: Plutellidae) in Hangzhou, China.

An investigation of insect parasitoids of the diamondback moth, Plutella xylostella (Linnaeus), in brassica vegetable crops in the suburbs of Hangzhou was conducted during five periods from 1989 to 1997. Eight species of primary parasitoids were recorded: Trichogramma chilonis Ishii, Cotesia plutellae Kurdjumov, Microplitis sp., Oomyzus sokolowskii Kurdjumov, Diadromus collaris (Gravenhorst), Itoplectis naranyae (Ashmead), Exochus sp. and Brachymeria excarinata Gahan. Seven species of hyperparasitoids were also collected. Rates of parasitism of eggs of P. xylostella were usually very low. However, rates of parasitism of larvae and pupae were substantial and showed two peaks each year, around June-July and September-November respectively. Rates of parasitism during peaks were usually 10-60% and reached over 80% on a few occasions. Cotesia plutellae, O. sokolowskii and D. collaris were the major larval, larval-pupal and pupal parasitoids respectively. In the field, C. plutellae was active throughout the year. Oomyzus sokolowskii was active from May to October, entered a quiescent pupal stage in October-November to overwinter and did not emerge until next April-May. Diadromus collaris was recorded from April to July and October. Rates of parasitism of P. xylostella in radish and mustard fields were usually higher than those in cabbage and Chinese cabbage fields in the same locality. Negative correlations of parasitism rates between C. plutellae and O. sokolowskii indicate a competitive relationship for host larvae between these two larval parasitoids.

Animals↗
PubMed2000

Two hundred and seventeen cases of winter diseases treated with acupoint stimulation in summer.

217 cases of chronic bronchitis and asthma were clinically treated and analyzed for the effects of combining electric stimulation with topical application of drug on acupoints. The results suggested that the combined therapy was superior to unitary therapy (P < 0.05). It is indicated that the combined therapy has a good curative effect in both short- and long-terms.

Acupuncture Points↗
PubMed2000

Clinical observation on treatment of non-parvicellular carcinoma of the lung with jin fu kang oral liquid.

Jin Fu Kang Oral Liquid ([symbol: see text]), made of traditional Chinese drugs for supplementing qi and nourishing yin, was developed according to the common symptoms in lung carcinoma with deficiency of both qi and yin. Of the 96 cases in the Jin Fu Kang group, 1 case got complete remission (CR) after treatment, 8 cases partial remission (PR), 52 cases no change (NC), PR + NC covering 63.5%. Of the 52 cases in the group of Jin Fu Kang plus chemotherapy, 11 cases got PR after treatment, 26 cases NC, PR + NC covering 71.2%. Of the 25 cases in the chemotherapy group, 4 cases got PR after treatment, 11 cases NC, PR + NC covering 60.0%. The results show that the therapeutic effectiveness in the Jin Fu Kang group and the group of Jin Fu Kang plus chemotherapy was better than that in the chemotherapy group. The one-year survival rate and the two-year survival rate after treatment in the Jin Fu Kang group were 67.3% and 67.3% respectively; 66.7% and 66.7% in the group of Jin Fu Kang plus chemotherapy; and 40.3% and 0.0% in the chemotherapy group. The improvement of clinical symptoms, increase of body weight and improvement of health situation (KPS marks) after treatment in both the Jin Fu Kang group and the group of Jin Fu Kang plus chemotherapy were better than that in the chemotherapy group. Some indicators of immunology and hemogram after treatment were greatly improved in the Jin Fu Kang group, worse in the chemotherapy group, but no obvious improvement in the group of Jin Fu Kang plus chemotherapy.

Adenocarcinoma↗
PubMed2000

A clinical investigation on garlicin injectio for treatment of unstable angina pectoris and its actions on plasma endothelin and blood sugar levels.

To investigate the therapeutic effects and mechanisms of garlicin for treatment of unstable angina pectoris (UAP), garlicin injectio was intravenously dripped 60 mg/day in 34 cases for 10 days. Nitroglycerine was used in 21 cases of the control group. The results showed that the total effective rates in improving symptoms and electrocardiogram after garlicin treatment were respectively 82% and 62%, and that the plasma endothelin and blood sugar levels were markedly lowered in cases with hyperglycemia.

Aged↗
PubMed2000

[Mechanisms of drug resistance of primary renal cell carcinomas and their clinical significance].

OBJECTIVE: By multifactorial analysis, to study the mechanisms of drug resistance of primary renal cell carcinomas (RCC). METHODS: Seventy cases of paraffin-embedded RCC tissue sections were examined for the expression of P-gp, GST-pi and Topo II by immunohistochemical staining. RESULTS: There was 65.7% of RCC with expressed P-gp. Its Expression was stronger in late than in early stage of RCC. GST-pi was expressed in 41.1% RCC, but the magnitude of expression did not correlate with differentiation, type and stage of RCC. All the RCC examined had Topo II expression. Its expression level was lower than that of cancer of the intestine and lung. Among the 70 cases of RCC, 31.4% of them expressed at least one of the 3 drug-resistance parameters. Co-expression of two drug-resistance parameters was observed in 42.8% of the cases that of 3 drug-resistauce parameters in 22.9% of the cases. CONCLUSION: Drug resistance is of common occurrence in RCC. To achieve better therapeutic efficacy, appropriate chemotherapeutic agents should be given to patients with low expression of P-gp and GST-pi but high expression of Topo II.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed2000

[Infusion chemotherapy and chemoembolization of liver metastases from cancer of the alimentary tract].

OBJECTIVE: To evaluate the efficacy of hepatic artery infusion chemotherapy and chemoembolization in the treatment of liver metastases from alimentary tract cancer. METHODS: A total of 92 patients with unresectable liver metastases from alimentary tract cancer was treated 316 times by hepatic artery infusion chemotherapy and chemoembolization. Of the 92 patients, only infusion chemotherapy was performed in 29 patients, and infusion chemotherapy and chemoembolization in 63 patients. Chemotherapy was carried out with a combination of epirubicin and/or cisplatin, mitomycin-C, calcium folinate and 5-fluorouracil. Embolization was accomplished with lipiodol ultra-fluid or lipiodol ultra-fluid and gelatin sponge. Response rates were assessed by CT scanning. RESULTS: An overall response rate (CR + PR) of the cases was 45.7%. The mean survival period of 92 patients was 19.6 months. The 0.5-, 1-, 2-, 3- and 5-year survival rate was 95.7%, 73.8%, 30.9%, 17.6% and 9.9%, respectively. Best therapeutic results were obtained in 9 cases with single metastatic focus in the liver, with a mean survival period of 31.2 months. There was no severe side effect or complication. CONCLUSION: Treatment by transcatheter hepatic artery infusion chemotherapy and chemoembolization is beneficial to patients with metastatic cancer of the liver.

Adult↗
PubMed2000

[Separation of thoracopagus conjoined twins].

OBJECTIVE: To sam up the experience in diagnosis and separation of a thoracopagus conjoined twins. METHODS: Thoracopagus twin boys were admitted for evaluating possible separation and repair at age of 21 days. X-rays, CT, MRI, and ultrasound scan of torso showed separate and normal gastrointestinal and biliary tracts, little shared vasculature, but shared pericardium, diaphragm and liver parenchyma. The chest junctions were at the sternums and the most inferior two pairs of the ribs. One twin (twin A) had a protruding heart with VSD and ASD. RESULTS: The infants were separated successfully at age of 45 days. The chest defect of twin A was closed with aid of a polyester pericardial patch graft and a silicon supporter. Managing anesthesia met some difficulty in understanding of the anatomical and physiological consequences of the complex anomaly. They are had brain edema and multiple system organ failures after separation, and were cured under intensive care. They are alive and well 6 months after surgery. CONCLUSIONS: Careful preoperative evaluation proper anesthesia and surgical technique, and postoperative care are essential to the successful separation of the conjoined twins.

Anesthesia↗
PubMed2000

[Thoracolumbar injuries: pathomorphology of and a new classification].

OBJECTIVE: To introduce a new classification of thoracolumbar injuries. METHODS: Three modes were used to classify the injuries according to the mechanisms of injuries: Type A, flexion-compression fractures; Type B, vertical compression fractures; Type C, distraction injuries. Two groups were used to distinguish the fractures in one type according to the pathomorphological differences and the clinical incidence: Group A, with a more clinical incidence, and Group B, with a less clinical incidence. Three subgroups were used to divide the injuries in one group in consideration of the severity of the fracture instability and the fracture displacement: fracture, subluxation, and dislocation. RESULTS: A new classification of thoracolumbar fractures was established. CONCLUSION: The new classification is more systemic and more convenient.

Humans↗
PubMed2000

[Diagnosis and treatment of thoracic myelopathy due to degenerative thoracic spine disease].

OBJECTIVE: To summarize the experience in the early diagnosis and treatment of chronic thoracic myelopathy due to the compression of degenerative thoracic spine disease. METHODS: 21 patients with thoracic spinal stenosis were operated on from January 1995 to April 2000. Etiologically 16 patients were found to have ossification of the ligamentum flovum, 3 Scheuermann's disease, and 2 DISH. They were confirmed by CT, CTM, MRI and Magnetic MEP. Decompression was performed by en block unroof laminectomy for the posterolateral wall of the thoracic canal. The epstein criteria were used to judge the operative results. RESULTS: In the 21 patients 5 belonged to localized type, 10 continuous type, and 3 skip type in 21 cases. Three patients showed a compression from the anterior side, and 3 were complicated by OPLL of the cervical spine. Results were excellent in 4 patients, good in 8, improved in 2, and poor in 1. One patient was operated on two times because the extent of laminectomy was not enough for the first operation. CONCLUSIONS: Early diagnosis can be made if orthopedists are familiar with the clinical characteristics of thoracic myelopathy, and are alert to thoracic spine stenosis. En block unroof laminectomy is effective and safe to treat thoracic spine stenosis.

Adult↗
PubMed2000

[Resection of pelvic retroperitoneal neoplasm and reconstruction of iliac blood vessels: report of 22 cases].

OBJECTIVE: To study the surgical manipulation of iliac blood vessels invaded by pelvic tumors in order to raise the resection rate. METHODS: We reviewed 22 cases of resection for pelvic retroperitoneal tumors along with the reconstruction of iliac blood vessels in our hospital from July 1994 to January 2000. In 22 cases, 8 received operation on the right iliac arteries and veins, and 14 on the left. RESULTS: Follow-up for 4 months to 5 years and 10 months (average 3.6 years) showed that 3 patients had recurrence and needed secondary operation. All the grafts were patent except one vein graft occlusion 7 months after operation. CONCLUSION: Resection of pelvic retroperitoneal neoplasm combined with reconstruction of iliac blood vessels is safe, effective and practical to raise the excision rate and decrease the recurrence rate.

Adult↗
PubMed2000

[Vitrectomy for pseudophakic retinal detachment].

OBJECTIVE: To study the method of vitrectomy for treatment of pseudophakic retinal detachment. METHODS: 32 pseudophakic retinal detachment eyes were treated with vitrectomy, primary vitrectomy in 11 eyes (34.4%), vitrectomy after conventional buckling failure in 21 eyes (65.6%), combined with silicone oil 10 eyes (31.3%), removal of intraocular lens 12 eyes (37.5%). All eyes had passed the 6 months to 5 years of follow-up examination. RESULTS: Intra-operative new retinal breaks were identified in 7 eyes (21.9%). The retinal total reattachment was in 25 eyes (78.1%); part reattachment was in 4 eyes (12.5%), and their visual acuity was improved than that before the operation. Due to severe proliferative vitreoretinopathy (PVR), failure occurred in 3 eyes. CONCLUSIONS: The main advantage of vitrectomy is the better intra-operative sight to the peripheral retinal breaks, removal of retinal traction and the low rate of PVR after vitrectomy. Vitrectomy for complicated type of pseudophakic retinal detachment can improve the success rate of the retinal detachment surgery and the visual acuity outcome.

Adult↗
PubMed2000

[Using multiplex PCR for the detection of virulence genes in Escherichia coli O157:H7].

OBJECTIVE: To detect and characterize the virulence genes in E. coli O157:H7 isolated from various reservoir in six areas of Jiangsu province. METHOD: The virulence genes of Shiga-like toxin (SLT(1) and SLT(2)), intimin (eaeA) and hemolysin (hlyA) were chosen as the target genes and amplified in multiplex PCR assays. RESULTS: Of the eighty-five E. coli O157:H7 strains, the overall virulence gene prevalence was found to be 56.5% (48/85). The prevalence rates virulence genes of isolates from various areas were different from 0% up to 90.5%. It seemed to exist a relationship between the virulence gene prevalence and the level of incidence. In the areas where rates of incidence were divided into high, low, sporadic or zero, the prevalence rates were 85.7% (36/42), 52.6% (10/19) and 8.3% (2/24), respectively. The prevalence rates of isolates were also different from various reservoirs, decreasing by sheep, cattle, pig and poultry. One isolate from a rabbit was positive for SLT(2), eaeA and hly genes. Of forty-eight isolates carrying virulence genes, 38 (79.2%) had SLT(2), eaeA and hly genes, taking the dominate virulence gene pattern, 8 (16.6%) had all of the four virulence genes 2 (4.2%) had both SLT(2) and hly genes respectively. In addition, SLT(1) gene showed a lower prevalence, which was different from some findings abroad. CONCLUSION: Since virulence gene pattern of E. coli O157:H7 is an important molecular epidemiological marker, it can provide an useful information for epidemiologic studies, and helpful to the design of prevention and control strategies. For virulence gene detection, multiplex PCR seems to be a simple, rapid, specific and sensitive method.

Adhesins, Bacterial↗
PubMed2000

[The sifnificance and characteristics of the internal distribution of Staphylococcal enterotoxin B in burned rats with sepsis].

OBJECTIVE: To investigate the role of staphylococcal enterotoxin B (SEB) in the development of postburn staphylococcus aureus sepsis. METHODS: Rats inflicted with 20% TBSA III degree scald followed by Staphylococcus aureus sepsis were used as the experimental subjects. The distribution of SEB in the vital organs such as the heart, liver, lungs, kidneys and plasma was observed with concomitant serial measurement of the relative organ functional indices. RESULTS: The plasma SEB content increased transiently in the early stage of sepsis (P < 0.01) and then fell to near that of control group. The SEB contents in the heart, liver, lungs and kidneys increased evidently 2 hours after staphylococcus aureus challenging (P < 0.01) and continued to increase afterwards. The functions of multiple organs were impaired obviously at 24 postburn hours, and the function impairment was aggravated by S. aureus challenge. The degree of organ injury of liver and kidneys correlated positively with tissue content of SEB (P < 0.05 similar 0.01). CONCLUSIONS: Staphylococcal enterotoxin B might play a role in the development of MODS induced by postburn sepsis.

Animals↗