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Biomedical subjects

R Sheng

Publications and source records attributed to R Sheng.

At least 19 recordsLinked to original sources
PubMed2001

Production of no-carrier-added 186Re via deuteron induced reactions on isotopically enriched 186W.

Rhenium-186 was produced from the reaction induced by 16 MeV deuterons on isotopically enriched 186W metal powder target. Following its separation from 187W, 183Ta and the bulk of target materials 186W through an acid alumina column, the 186Re was converted to HNO3 solution through an anion exchange column, or to ammonia solution by extracting with N-235-dimethylbenzene, and finally the no-carrier-added 186Re saline solution was obtained. The radionuclidic purity of 186Re was >99.9% and the isotopic impurities were mainly 183Re (5.0 x 10(-3)%) and 184gRe (4.6 x 10(-2)%). The experimental thick-target yield of 186Re was determined to be approximately 529 microCi/microA h and the overall chemical recovery yield was > 80%.

Kinetics↗
PubMed2001

[The expression and clinical significance of proliferative antigen Ki-67 and apoptosis-antagonizing antigen Bcl-2 in non-Hodgkin's lymphoma].

OBJECTIVE: To evaluate the expression of proliferative antigen Ki-67 and apoptosis-antagonizing protein Bcl-2 as well as their clinical significance in non-Hodgkin's lymphoma (NHL). METHODS: Ki-67 antigen and Bcl-2 protein were measured by immunohistochemistry on paraffin -embedded slices in 35 cases of NHL. RESULTS: (1) The level of Ki-67 expression in low grade NHL was lower than that in high grade NHL (P < 0.01),while Bcl-2 expression in lower grade NHL was higher than that in high grade (P < 0.01). (2) The level of Bcl-2 expression in B cell NHL was higher than that in T cell NHL (P < 0.02), but there was no difference in the expression of Ki-67. (3) The level of Bcl-2 expression in remission group was lower than that in non-remission group after the first course of chemotherapy, but there was no significant difference in Ki-67 expression. (4) The survival time was longer in the group with Ki-67 < or = 20% than that in the group with Ki-67 > 20%, but there was no significant difference of survival time between the high and low expression group of Bcl-2. CONCLUSIONS: The level of Ki-67 and Bcl-2 expression was closely related with the grade of malignant and the prognosis of NHL. They were a pair of useful markers for understanding the generation and prognosis of NHL.

Adolescent↗
PubMed2001

[Ultrastructure changes of the olfactory epithelium of the patients suffering from dysosmia caused by the chronic sinusitis].

OBJECTIVE: To observe the ultrastructural changes of olfactory epithelium (OE) in patients suffering from dysosmia caused by chronic sinusitis. METHODS: The specimens of olfactory epithelium were obtained from 35 patients operated for chronic sinusitis accompanied by dysosmia. According to the results of light microscope (LM) examination, the OE was divided into three groups by the types of pathological changes: normal, atrophic and respiratory epithelium metaplasia(REM). Transmission electron microscope was used to observe the ultrastructural changes of each group. RESULTS: Under the LM, the surface ultrastructure of the OE showed some abnormal changes: (1) surface microvillus of the supporting cells disappeared; (2) olfactory vesicle changed their shape due to vacuolization; (3) disappearance of canaliculus structure in the olfactory vesicle; (4) the olfactory cilia changed the shape or reduced; some of the reduced cilia underwent metaplasia. The ultrastructural changes of atrophic OE included: (1) minor and moderate atrophy: the organelles and the membrane-limited electron dense vesicles on the upper section of the supporting cells obviously decreased or disappeared, even underwent vacuolization. The basic cell degenerated; (2) serious atrophy: the turbidity of the cell structure, even double cell structure, the nuclei of the cell aggregated as the plaque and vesiculose change or karyopyknosis. As for the cytoplasm, there were the dilation of the ERs, turgidity of the mitochondrion, the disarrangement, diminution and vacuolization. Fasciculate cilia were distributed separately in the REM group. CONCLUSION: There is a positive relationship between the atrophy degree and the degree of the abnormal ultrastructural changes of the OE. The ultrastructural changes of OE in patients suffering from dysosmia caused by chronic sinusitis may provide reference for assessment of the treatment of dysosmia.

Adult↗
PubMed2000

[The diagnosis and treatment of Lyme disease: a report of six cases].

We retrospectively analyzed the clinical features, diagnosis, treatment, and prognosis of 6 cases of Lyme disease from November, 1994 to December, 1998. According to our report, doxycycline, penicillin, and ceftriaxone are effective drugs for Lyme disease. The shorter the disease course is, the better the treatment effect will be. Patients in phase III usually need repeated treatment.

Adolescent↗
PubMed1999

[Study of 6 cases of AIDS with pulmonary complication].

OBJECTIVE: To improve and to increase the awareness of pulmonary complications of AIDS. METHODS: Six cases of confirmed AIDS from may 1992 to August 1997 were analyzed. RESULTS: Of the six cases, there were five complicated with pneumocysitis carinii pneumonia (PCP) (in which one had PCP as the first occurred manifestation). The clinical presentations of PCP were fever(5/5), dyspnea on exertion or at rest(4/5), and hypoxemi with mean PaO2 of 58.1 mm Hg. Chest X-ray showed bilateral diffuse interstitial or alveolar infiltrates. Pulmonary tuberculosis, tuberculous lymphadenities (fast-acid staining positive but PPD negative) and bronchial fungal infection were found in three cases. CONCLUSIONS: AIDS patients are at high risk of suffering from pulmonary complications, of which PCP is more common. If young pateints who were healthy in the past suddenly suffered from pneumonia and respiratory failure, PCP should be considered. When opportunistic pulmonary infections are diagnosed under special circumstances, one should be alert to the possibility of AIDS. In these cases serum HIV antibodies should be checked immediately.

AIDS-Related Opportunistic Infections↗
PubMed1998

[Investigation of the genetic instability of tumor cells by transfection of RER+ cell lines with exogenous microsatellite sequence].

OBJECTIVE: Frequent alterations of microsatellite sequence of cancer cells were found recently in a substantial fraction of human cancers including hereditary non-polyposis colon cancer. This paper aimed to investigate the genetic instability of tumor cells by using microsatellite instability(MI) as the marker in vitro. METHODS: Two RER+ cell lines (replication error phenotype), RKO and HCT116 and one RER- cell line, sw480, were used as the hosts for transfection with an episomal plasmid, pCMV-CAR, containing an exogenous (CA)14 repeat which was inserted within the coding sequence of lacZ reporter gene and thus made lacZ misreading. The transfectant clones were selected and established by hygromicin. Expression and production of lacZ reporter gene of restored reading frame were detected with X-gal staining assay. RESULTS: After hygromicin selection, stable pCMV-CAR transfectant clones were established. It was shown that mutation of deletion of insertion within(CA)14 occurred in the transfectant RER+ cells but not in the RER-cells. The mutation restored normal reading frame of lacZ gene, and resulted in expression and production of bio-active beta galactosidase which was detected with X-gal staining. This feature of the transfectant clones was maintained during culture passages. CONCLUSION: The alterations of the exogenous(CA)14 repeat in the transfectant RER+ clones revealed genetic instability and complicated mutation status of cancer cells. It is suggested that the exogenous (CA)14 in transfectant clones could be a useful target sequence for monitoring the effects of environmental agents on MI of human cancer cells.

Cell Line↗
PubMed1997

Hypervascular liver metastases: do unenhanced and hepatic arterial phase CT images affect tumor detection?

PURPOSE: To evaluate the relative roles of unenhanced and hepatic arterial phase (HAP) computed tomographic (CT) imaging in the detection of hypervascular liver metastases. MATERIALS AND METHODS: Eighty-four patients with biopsy-proved liver metastases from hypervascular primary tumors other than hepatocellular carcinoma underwent unenhanced and HAP and portal venous phase (PVP) helical CT studies. Three blinded radiologists evaluated each series of images separately for the number, size, and enhancement characteristics of lesions. Sixty-nine patients had follow-up imaging proof of tumor burden. RESULTS: The three readers detected 381-402 lesions on the PVP images and 397-416 lesions on the unenhanced images. Unenhanced images allowed detection of 72%-80% of the lesions seen on PVP images. They detected 94-137 additional lesions on unenhanced but not PVP images. On the HAP images, 375-395 lesions were identified. HAP images allowed detection of 81%-90% of the lesions seen on PVP images. Forty-five to 78 additional lesions were detected on HAP but not on PVP images. In the 69-patient subset, maximal detection of tumor foci occurred in 94% of patients with unenhanced plus PVP images and in 78% with HAP plus PVP images. Unenhanced plus PVP images allowed detection of 96% of the 322 tumors in the subset population. CONCLUSION: Unenhanced plus PVP CT images allow detection of statistically significantly more hypervascular liver metastases than do HAP plus PVP images or imaging only in the PVP.

Contrast Media↗
PubMed1997

[Hepatitis C virus infection among long-term hemodialysis patients].

We determined the prevalence and incidence of hepatitis C virus (HCV) infection among hemodialysis patients and evaluate their risk factors. 80 patients on maintenance hemodialysis in Peking Union Medical College Hospital Dialysis Center from December 1994 to June 1995 were studied. 30 medical students were used as health controls. Serum samples were tested for HCV antibodies by a second-generation enzyme-linked immunosorbent assay (ELISA) and for HCV RNA using nested polymerase chain reaction (PCR) and retested for anti-HCV and HCV RNA three months later. 24 (30%) of 80 hemodialysis patients were anti-HCV positive, and 2 (3.6%) of 56 anti-HCV negative cases were found HCV RNA positive. By combined assessment, the HCV infection rate of hemodialysis patient was 32.5% (26/80). Mantel-Haenszel analysis showed that HCV infection was associated with multi-transfusions, dialysis over a long period, renal transplantation, history of operation. Samples of dialysate in 9 serum HCV RNA positive cases were directly detected for HCV RNA, and 3 were found HCV RNA detectable. HCV infection rate in hemodialysis patients is higher than that of general population. The main risk factors for HCV transmission is transfusion of unscreened blood but is not an independent factor, hemodialysis itself plays an important role, the length of time on dialysis, renal transplantation, blood-contaminated material and contaminated dialysis equipment are also the risk factors. Infected hemodialysis patients should be isolated.

Adult↗
PubMed1997

[Study on the clinical and biological characteristics of 20 cases of chronic lymphoid leukemias].

OBJECTIVE: To further define the chronic lymphoid leukemia (CLL). METHODS: Tweenty cases of CLL classified after the FAB proposals (1989) were retrospectively analyzed. RESULTS: Based on the clinical features, cell/tissue morphology, immunophenotype, IgH and TCR gamma gene rearrangement serum or urine immunoglobulin levels, 16 cases of B-lymphoid leukemia (12 of CLL, 1 of PLL, 2 of leukemia/lymphoma, and 1 of WM) as well as 4 cases of T-lymphoid leukemia (2 of leukemia/lymphoma, 1 of T-LGLL, and 1 of NK-LGLL) were identified. The diagnostic criteria,cell morphology,biological characteristics and prognosis for CLL were discussed. CONCLUSION: T-leukemia/lymphoma should be incorporated in the classification of CLL.

Chronic Disease↗
PubMed1997

[Absorption spectra study for fullerene-doped in polystyrene film].

The absorption spectra of C60 and C70-doped in polystyrene film and in solution were studied. The experiment results showed that the positions of the absorption peaks for C60-doped in polystyrene film moved a little toward longer wavelength than in n-hexane, and regular solid material appeared while the ratio of C60-doped in the film increased; The absorption peaks for C70-doped in polystyrene film were almost in consistent with that in solution. We suggest that C60 molecules may be connected as "microcrystalline" in polystyrene film, while C70 may be exist as single molecule or particle less than C60 in it. The preliminary model for the growth of "microcrystslline" in polystyrene film has been proposed.

English Abstract↗
PubMed1997

[Lyme neuroborreliosis with acute meningitis as the presenting manifestation: report of a case].

To enhance the understanding of Lyme disease, a case of Lyme neuroborreliosis with acute meningitis as the presenting manifestation was reported. The diagnosis was confirmed by elevated serum antibody response to B. burgdorferi using both ELISA and Western blotting, excluding other causes of neurological abnormalities and the typical response of our patient to antibiotics. This case indicates the existence of Lyme disease in Beijing area. If the etiology of a meningitis with lymphocytic pleocytosis is not known, it is important that Lyme neuroborreliosis should be considered as one of the differential diagnoses and detection of antibody to B. burgdorferi in serum and cerebrospinal fluid performed in time. A brief review of the literature including epidemiology, clinical menifestations, diagnosis and treatment of Lyme disease was made.

Adult↗
PubMed1996

Assessment of clinical and communication skills: operationalizing Benner's model.

The introduction of ward-based clinical assessment of nursing skills in the 1970s meant a more realistic method of assessment, but still essentially a 'snapshot' of the student's practical abilities. This now being replaced by continuous clinical assessment which requires that student nurses meet the expected level of competence in a range of nursing skills in each clinical placement. Benner's (1984) model of skill acquisition is currently receiving considerable attention by nurse educationalists and is providing the framework for many curricula (English 1993). The model identifies five stages of development in nursing: novice; advanced beginner; competent; proficient; and expert. What is needed, however, is a more detailed description of what those stages mean in terms of the component parts of nursing, especially the clinical and communication skills. This paper describes a framework for the assessment of clinical and communication skills, a framework which seeks to operationalize Benner's model by defining the level of performance expected in clinical and communication skills at each stage.

Clinical Competence↗
PubMed1996

Biliary stones and sludge in liver transplant patients: a 13-year experience.

PURPOSE: To determine the prevalence, radiologic features, and clinical significance of bile duct filling defects (BDFDs) in liver transplant recipients studied with cholangiography. MATERIALS AND METHODS: During 13 years, 4,100 cholangiograms were obtained in 1,650 patients. All studies showing BDFD suggestive of stones, sludge, cast, or necrotic debris were retrospectively evaluated. RESULTS: The prevalence of BDFD was 5.7% (n = 94). On the basis of cholangiographic appearance, BDFDs were categorized as sludge or cast in 53 grafts (56%), stones in 32 (34%), and necrotic debris in nine (10%). Forty-three patients (46%) underwent surgical biliary reconstruction, while 14 (15%) underwent interventional radiologic treatments. Twenty-four of 32 stones (75%) were treated with surgical reconstruction, compared with 31% (19 of 62 grafts) of other BDFDs (P < .0001). Necrotic debris and sludge were associated with hepatic artery occlusion in seven of nine (78%) and 16 of 53 (30%) grafts, respectively. CONCLUSION: Stones and sludge are relatively infrequent after liver transplantation but are associated with high morbidity. Surgical or interventional radiologic treatments are usually performed. Bile duct stones are usually treated with surgical biliary reconstruction. While debris and bile duct necrosis are due to ischemia from hepatic artery occlusion, sludge may also have an ischemic pathogenesis in some cases.

Adolescent↗
PubMed1996

Cholangiographic features of biliary strictures after liver transplantation for primary sclerosing cholangitis: evidence of recurrent disease.

OBJECTIVE: Biliary strictures occur more frequently after liver transplantation for primary sclerosing cholangitis (PSC) than for other diseases. A hypothesized cause is recurrence of PSC in the liver graft. In our study, we compared cholangiographic features of biliary strictures after transplantation for PSC to those after transplantation for other diseases. MATERIALS AND METHODS: A study group of 32 PSC grafts in adults with biliary strictures was compared with a control group of 32 non-PSC grafts with strictures. Both groups were matched for the type of biliary anastomosis (choledochojejunostomy) and for the time interval between transplantation and stricture diagnosis. We then performed a blind retrospective review of cholangiograms in these 64 cases to evaluate for features of PSC. RESULTS: Location, number, and length of strictures and ductal dilatation were similar in the PSC and non-PSC groups. Mural irregularities of bile ducts were present in 15 of 32 (47%) PSC grafts compared with four of 32 (13%) in the control group (p=.005). Diverticulum-like outpouchings occurred in six of 32 (19%) PSC graft compared with one of 32 (3%) in the control group. An overall resemblance to PSC was observed in eight of 32 (25%) grafts in the PSC group compared with two of 32 (6%) in the control group. CONCLUSION: Mural irregularity and diverticulum-like outpouchings--findings suggestive of PSC--and an overall appearance resembling PSC occur more frequently in PSC transplants than in transplants for other diseases. These findings are consistent with the hypothesis that PSC may recur in liver transplants.

Adult↗
PubMed1996

[A prospective study on post-transfusion hepatitis C].

A cooperative prospective study on the clinical epidemiology of post-transfusion hepatitis C virus (HCV) infection was carried out from April 1993 to November 1994 in four medical schools in China, namely, Peking Union Medical College (PUMC), Western China Medical University (WCMU), Shanghai Medical University (SMU) and Beijing Medical University (BMU). A screen test on anti-HCV was done for the healthy donors of four groups. Anti-HCV positive rate was found to be 14.49% in professional blood donors, 5.60% in rural donors and 0.42% in urban volunteer donors. The positive rate of anti-HCV in blood recipients followed more than three months after transfusion was quite different in the four institutes, being 15.34% (14/91) in PUMC, 24.59% (15/61) in WCMU, 13.18% (12/91) in SMU and 1.53% (1/65) in BMU. During the same period post-transfusion hepatitis B virus infection rate decreased as compared with that in the past. It is concluded that the screen test on anti-HCV in blood donors can not completely rule out post-transfusion HCV infection.

Blood Donors↗
PubMed1995

Hepatic artery stenosis in liver transplant recipients: prevalence and cholangiographic appearance of associated biliary complications.

OBJECTIVE: The occurrence of biliary strictures or bile duct necrosis in liver transplant recipients with hepatic artery stenosis has been well documented. This study was done to determine the prevalence and cholangiographic appearance of biliary complications in liver transplant recipients with hepatic artery stenosis and to determine if such complications occur with increased frequency compared with transplant recipients with patent hepatic arteries. MATERIALS AND METHODS: The study population consisted of 33 patients (17 male, 16 female; 1-65 years old) with angiographically proven significant hepatic artery stenosis after liver transplantation. All patients had T-tube or percutaneous transhepatic cholangiography performed within 4 months of hepatic arteriography. A retrospective review of radiographs was done to determine the prevalence and appearance of biliary complications in the study group compared with a control group of 58 patients with angiographically patent hepatic arteries who had liver transplants during the same period. RESULTS: Biliary complications were significantly more prevalent in patients with hepatic artery stenosis, with 22 (67%) showing cholangiographic abnormal findings compared with 16 (28%) in the control group (p = .001). The most significant abnormalities in patients with arterial stenosis were nonanastomotic biliary strictures seen in 16 (49%), compared with 13 (22%) in the control group (p = .04). Other findings (intraductal filling defects, anastomotic biliary stricture, and anastomotic bile leak) showed no statistically significant difference between the study and control groups. CONCLUSION: Biliary complications are significantly more prevalent in liver transplant recipients with hepatic artery stenosis. The most common complication seen on cholangiography was nonanastomotic biliary stricture.

Adolescent↗
PubMed1994

Intrahepatic biliary strictures after liver transplantation.

PURPOSE: To evaluate the prevalence, cholangiographic features, causes, and management of intrahepatic biliary strictures in hepatic transplants. MATERIALS AND METHODS: Over a 12-year period, cholangiography was performed in 1,590 liver allografts. Confirmed cases of stricture were evaluated and correlated with clinical variables. RESULTS: Intrahepatic biliary strictures occurred in 130 of 1,590 grafts (8.2%). Strictures were multiple in 99 grafts (76.2%) and single in 31 (23.8%). Locations were the common hepatic duct bifurcation in 46 grafts (35.4%), the peripheral ducts in 44 (33.8%), and both in 40 (30.8%). Strictures caused mild to moderate bile duct dilatation in 72 grafts (55.4%), marked dilatation in 11 (8.5%), and obstruction in four (3.1%). Hepatic artery occlusion, pretransplantation primary sclerosing cholangitis, choledochojejunostomy, use of Euro-Collins organ preservation solution, cholangitis at liver biopsy, and young age were statistically significantly associated with strictures (P < .001). CONCLUSION: Strictures have multiple causes and may be an important indicator of underlying abnormalities. They often require interventional radiologic or surgical treatment.

Adolescent↗