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Biomedical subjects

Z Duan

Publications and source records attributed to Z Duan.

33 records · Page 2Linked to original sources
PubMed1999

[Effects of inflammatory infiltration on the formation of abdominal aortic aneurysm].

OBJECTIVE: To explore inflammatory infiltration and its effects on the formation of abdominal aortic aneurysm (AAA). METHODS: Immunohistochemical technique was used to detect lymphocyte (CD45 positive) and macrophage (CD68 positive) infiltration while in situ hybridization was applied to investigate the mRNA expression of Matrix Metalloproteinase-9 (MMP-9) in 20 cases of human AAA and 4 cases of normal human abdominal aortas. RESULTS: Inflammatory infiltration occurred in every case of AAA with various degree, and there was a parallel tendency between the degree of injury of abdominal aortic elastin and that of inflammatory infiltration in AAA. Inflammatory infiltration was not found in normal aortas. MMP-9 mRNA was detected in macrophages and lymphocytes in all 20 cases, in smooth muscle cells in 13, and not in normal abdominal aortas. CONCLUSIONS: Inflammatory infiltration attended and enhanced the formation of AAA through a complex of sequence of biochemical, cellular and immune events.

Aortic Aneurysm, Abdominal↗
PubMed1998

[Reconstruction of esophagus by microsurgical technique in forty-five cases].

Reconstruction and repair of atresia or defect of the upper portion of esophagus is difficult. From November 1980 to December 1997, forth-five cases, consisting 35 males and 10 females, were treated with microsurgical technique. The 45 patients fell into the following groups as esophageal atresia of various causes in 21 cases, anastomotic fistula or stenosis following reconstruction of esophagus in 7 cases and late carcinoma of esophagus in 17 cases. The types of reconstruction consisted of transfer of free jejunum with its lower portion carrying a vascular pedicle in 24 cases, free transfer of jejunal graft in 15 cases, free vascularized jejunal graft in 2 cases and free vascularized tubular skin graft in 4 cases. After a follow-up of 6-19 months besides eight cases died from late esophageal carcinoma, thirty-seven cases were survived and could take food by mouth. All of the benign cases could return to work. In patients having late esophageal carcinoma, the operative procedure could improve the life quality and facilitate chemotherapy and radiotherapy.

Adolescent↗
PubMed1998

[Surgical treatment of extracranial carotid artery aneurysm].

OBJECTIVE: To study the experience in the treatment of extracranial carotid aneurysm. METHODS: 67 cases of extracranial carotid artery aneurysm(ECAA) were treated surgically from January 1986 to June 1997. RESULTS: There were a mortality rate of 1.5% and a hemiparalysis rate of 4.5%. CONCLUSION: Clinical examinations are important for diagnosis of ECAA. Angiography plays a significant role in understanding the morphology, function, pathophysiology of ECAA. To decrease postoperative cerebral ischemia, collateral circulation of cerebral vessels should be evaluated and matas test done. Correct operative method is a key factor for successfull treatment.

Adult↗
PubMed1998

[Ultrasonic angiography in therapeutic decision-making in peripheral occlusive vascular diseases].

OBJECTIVE: To study quickscan (QS) in different therapeutic decision-making in 55 patients with peripheral occlusive vascular diseases. METHODS: Based on QS results, 30 patients were treated conservatively. The disease progress and therapeutic effects were assessed by QS in every three months. Percutaneous transluminal angioplasty was performed successfully in 5 patients without prior diagnostic angiography. 20 patients were scheduled for surgery. Operation of eleven patients was guided by information obtained from QS findings only, which was confirmed during operation. Angiography was necessary in 9 patients except one to formulate a therapeutic strategy. RESULTS: The accuracy of QS was 92%(23/25). CONCLUSION: QS is of value in deciding the access route of angiography and PTA, and can replace preoperative angiography, Quickscan is time-saving, inexpensive, objective and accurate. It can be used in therapeutic decision making in peripheral occlusive vascular diseases and bypass grafting.

Adult↗
PubMed1998

[Management of true extremity aneurysms: experience in 23 patients].

OBJECTIVE: To explore the etiologic feature and specificity of diagnosis and treatment in true aneurysms of the extremities. METHOD: 23 patients with true aneurysms of the extremities from January 1984 to September 1997 were retrospectively reviewed. RESULT: Of 30 true aneurysms of the extremities, multiple aneurysms were found in 7 patients (30.4%). The multiple aneurysms were diagnosed in the same time or in different time. 21 patients were treated by exclusion of aneurysm and replacement with autogenous saphenous vein or graft. CONCLUSION: Early diagnosis and treatment are recommended to prevent complications which can cause limb loss, and multiple aneurysms must be taken into account. Importance of arteriography should be stressed in the diagnosis of multiple aneurysms. Exclusion of aneurysm and autogenous saphenous vein reconstruction is the first choice of treatment, circulation of the operated extremities should be noticed and close follow-up is imperative to pay attention to the development of new aneurysms.

Adolescent↗
PubMed1996

The accuracy of color Doppler flow imaging for the detection of symptomatic deep venous thrombosis in Chinese patients.

To evaluate the ability of color Doppler flow imaging (CDFI) to detect deep venous thrombosis (DVT), which is difficult to diagnose clinically, 67 limbs of 60 patients who presented with clinical signs strongly indicative of DVT during the period between June 1988 and June 1992, were examined. The iliac, common femoral, and superficial femoral veins were assessed with the patient in the supine position, and the popliteal vein was examined with the patient prone. Gentle but firm compression with the transducer probe was used to test for the presence of DVT. Ascending contrast venograms were also obtained within 24 h after the ultrasound procedure, with venography being used as the standard for comparison with CDFI. DVT was identified in 63 limbs by contrast venography and in 62 limbs by CDFI. The sensitivity and specificity of CDFI were 98.4% and 100%, respectively, while the positive and negative predictive values were 100% and 80%, respectively. The thromboses were classified into three patterns: the filling type, the local type, and mural thrombus, detected in 63%, 27%, and 10%, of the limbs respectively, with the filling type being the most common in this series. The results of our study illustrated that CDFI is highly sensitive and specific for detecting symptomatic DVT and that it should be gradually substituted for venography in such patients.

Adult↗
PubMed1996

Experience in prevention of serious complications of laparoscopic cholecystectomy.

OBJECTIVE: To study the causes and prevention of the complications of laparoscopic cholecystectomy (LC). PATIENTS AND METHODS: Based on experience with 2 428 cases, the following should be paid attention to when dissecting and separating adhesions around the gallbladder and of the Calot's triangle. The best method for the prevention of mistaking the common bile duct (CBD) for the cystic duct is to find the junction of the cystic infundibulum and duct, separate the gallbladder wall along the infundibulum, and transect the cystic duct at the junction with the infundibulum. If dense adhesions around the gallbladder or of the Calot's triangle are met with, LC should be abandoned and open the cholecystectomy (OC) should be used instead. In separating the Calot's triangle, blunt dissection should be used to avoid burning the extrahepatic bile duct (EHBD), and blind hemostasis should be avoided. If the cystic artery lies in the upper part and the back of the cystic duct, the cystic duct should be dissected out, clipped and cut first, then the cystic artery be dealt with. If the cystic artery is in the front part of the pedicle of the gallbladder, the artery should be separated, clipped and cut first. Injury to the adjacent organs may be avoided by using electric coagulating hook correctly and avoiding accidental damage to the viscera, and keeping from viscera injury due to current chemotaxis in the closed cavity of the body. RESULTS: A total of 2427 patients were cured. One patient died of frequent episodes of supraventricular tachycardia and pneumonia on the 21st day after LC. CONCLUSION: If LC surgeons follow the above said principles of LC technique. LC is very safe for patients with benign diseases of the gallbladder.

Adolescent↗
PubMed1995

A two-year experience with laparoscopic cholecystectomy--a report of 1475 cases from Kunming, China.

Over a 2-year period, from 12 September 1991 to 11 September 1993, laparoscopic cholecystectomy was performed on 1475 patients with benign gallbladder disease in Kunming General Hospital, Yunnan, China. Of these, 28 cases (1.9%) were converted to open surgery. Various complications were documented in 27 instances including extrahepatic bile duct injury in 4 cases (0.3%), postoperative haemorrhage requiring laparotomy in 3 cases (0.2%) and bile leak from cystic duct stump in 1 case (0.07%). There was 1 (0.07%) death in the series. The junction between the gallbladder infundibulum and the cystic duct is an important landmark which laparoscopic surgeons must identify in the course of the procedure. Because the junction remains a comparatively constant landmark, in difficult laparoscopic cholecystectomy, excessive dissection of the bile duct would be unnecessary. During dissection of the hepatic hilus, blund dissection is recommended and the blind use of cautery and haemostasis should be avoided.

Bile Ducts, Extrahepatic↗
PubMed1995

[Ultrasonic angiography in diagnosis of peripheral vascular disease].

The ability of Quickscan (QS) was studied to assess haemodynamically significant lesions in the iliac and femoro-popliteal arteries. Quickscan was prospectively and independently compared to digital subtraction angiography (DSA) of the iliac and femoro-poplited arteries. In 155 patients, 631 arterial segments were evaluated. A QS frequency ratio of greater than 1:3 had a sensitivity of 93% and a specificity of 85% in detecting stenosis > 50% diameter (75% area) reduction in the iliac artery as shown on DSA. The sensitivity and specificity for stenosis in the femoral and popliteal arteries were 85%, 96%, 82%, 98% respectively. In the detection of occlusion, QS had a sensitivity of 84% and a specifity of 98% in the iliac artery; 94%, 97%, in the femoral; and 94%, 85% in the popliteal arteries respectively. There was a significant correlation between the area reduction found by QS and the calf/brachial pressure index (CBI) (r = -0.77 P < 0.01). 35 patients underwent successfully angioplasty based on QS findings. We conclude that quickscan can provide an inexpensive, quick and noninvasive screening technique for the routine initial assessment of peripheral vascular disease.

Aged↗
PubMedDate not supplied

Purification and characterization of hedgehog liver metallothioneins.

Two forms of liver metallothioneins (MTs) were purified from hedgehog exposed to zinc, using gel filtration on Sephacryl S-100 and DEAE Sepharose Fast Flow chromatography. The peptide chain weight of both MT-1 and MT-2 was found to be about 10,000, as determined by high performance liquid chromatography. This value was higher than that calculated from amino acid analysis. The amino acid composition of hedgehog liver MT-1 and MT-2 resembles that of liver to MTs from rabbit and other species. Their distinctive features include an extremely high cysteine content, about 33% of all the amino acid residues, and an absence of aromatic amino acids and histidine. In addition, a rapid method for the determination of MTs during animal tissue purification has been established. The samples were directly added in an ammoniacal solution of a Co(II) salt for recording linear sweep polarograms. By comparison with the commonly used metal determination method, our method is direct, rapid, credible and suitable for all the MTs or MT-like samples.

Amino Acids↗
PubMedDate not supplied

Cloning and characterization of a potential transcriptional activator of human gamma-globin genes.

Hybrids produced by fusing human fetal erythroblasts (HFE) with mouse erythroleukemia (MEL) cells initially produce predominantly or exclusively human gamma-globin and switch to human beta globin expression as time in culture advances. One explanation for the initially predominant expression of gamma-globin gene in these hybrids is the presence of trans-acting factors that activate gamma-globin gene transcription. We used differential display of hybrids before and after the gamma to beta switch as well as fetal liver and adult erythroblasts to identify cDNAs that could be candidates for potential gamma gene activators. Identically sized amplicons which were present in fetal liver erythroblasts and in the hybrids expressing only gamma-globin but were absent in the adult erythroblasts and in the same hybrids after they had switched to beta globin expression were cloned and sequenced. Fifty pairs of cDNAs fitting these criteria were chosen for further analysis. The sequences of the two members of 48 pairs differed from each other, revealing the low efficiency of this experimental approach. One clone pair coded for human proteosome subunit X. The second pair coded for a protein containing an acidic domain in the N-terminus and three consecutive CDC10/SW16/ankyrin repeats in the C-terminus. Transactivation assays in the yeast hybrid system and transient transfection assays in COS cells showed that a potent trans-activating domain resides in the N-terminus of this protein. Northern blot and RT-PCR assays showed that this gene is expressed in several fetal tissues but not in adult tissues. Stable transfection assays provided evidence that the product of this gene may increase the level of gamma mRNA in HFE x MEL cell hybrids that undergo the gamma to beta switch, suggesting that this new gene encodes a protein that may function as gamma gene activator.

Amino Acid Sequence↗
PubMedDate not supplied

TRAG-3, a novel cancer/testis antigen, is overexpressed in the majority of melanoma cell lines and malignant melanoma.

BACKGROUND: We have identified a novel cancer/testis antigen, TRAG-3, (Taxol Resistance Associated Gene-3) that was initially discovered in search for new genes involved in drug resistance by differential display. Early study of TRAG-3 revealed minimal to absent expression in various normal tissues and over-expression in many carcinoma cell lines including several melanoma lines. MATERIALS AND METHODS: Northern and RT-PCR technologies were used to evaluate TRAG-3 expression in numerous cell lines and tumor tissue. RESULTS: Analysis of a wider panel of normal tissues, 32 melanoma cell lines and 4 malignant melanomas demonstrates TRAG-3 expression in 25 of the 32 melanoma cell lines (78%) and four of four of the malignant melanoma tumors (100%). Of the additional eight normal tissues screened, expression was present in normal testis but absent in all other tissues. RT-PCR evaluation of TRAG-3 reveals two transcripts in many carcinoma cell lines with sequencing of these products demonstrating the 799 bp TRAG-3 transcript and a second alternatively spliced transcript, TRAG-3long TRAG-3 maps to band Xq28 within a MAGE gene complex, however sequence analysis demonstrates that TRAG-3 is not homologous to other known cancer/testis antigens. CONCLUSION: TRAG-3 appears to be a novel cancer/testis antigen.

Base Sequence↗
PubMedDate not supplied

Overexpression of human phosphoglycerate kinase 1 (PGK1) induces a multidrug resistance phenotype.

BACKGROUND: Multidrug resistance is a significant barrier to the development of successful cancer treatment. To identify genetic alterations that are directly involved in paclitaxel resistance, a functional cloning strategy was developed. MATERIALS AND METHODS: Using mRNA from paclitaxel resistant human ovarian cancer cell line SW626TR, a cDNA library was established in a pCMV-Script vector that permits expression of cDNA inserts in mammalian cells. Transfection of the pCMV-Script/SW626TR cDNA library into the paclitaxel-sensitive human osteogenic sarcoma cell line, U-20S, resulted in several paclitaxel-resistant clones. RESULTS: DNA sequencing of clone C16 demonstrates complete homology to human phosphoglycerate kinase 1 (PGK1). Retransfection of the PGK1 insert into U-20S confers a multidrug resistant phenotype, characterized by a 30-fold increase in paclitaxel resistance, and cross-resistance to vincristine; adriamycin and mitoxantrone, but not methotrexate or cisplatin. Enzymatic analysis of the PGK1 transfectants demonstrates an increase in PGK1 activity as compared to the parental cell line, U-20S. Northern and Western analysis of PGK1 transfectants reveals no change in MDR-1 expression compared with the parental cell line. In addition, co-culture of PGK1 transfectants with verapamil only partially reverses the multidrug resistant phenotype. Rhodamine 123 studies are also consistent with an MDR-1 independent mechanism of increased drug efflux. CONCLUSION: Together this data suggests that PGK1 can induce a multidrug resistant phenotype through an MDR-1 independent mechanism.

Antineoplastic Agents↗