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Biomedical subjects

X Y Xie

Publications and source records attributed to X Y Xie.

At least 19 recordsLinked to original sources
PubMed2001

Diagnostic utility of flow cytometric immunophenotyping in myelodysplastic syndrome.

The myelodysplastic syndromes (MDSs) are characterized by bilineage or trilineage dysplasia. Although diagnostic criteria are well established for MDS, a significant number of patients have blood and bone marrow findings that make diagnosis and classification difficult. Flow cytometric immunophenotyping is an accurate and highly sensitive method for detection of quantitative and qualitative abnormalities in hematopoietic cells. Flow cytometry was used to study hematopoietic cell populations in the bone marrow of 45 patients with straightforward MDS. The results were compared with those obtained in a series of patients with aplastic anemia, healthy donors, and patients with a history of nonmyeloid neoplasia in complete remission. The immunophenotypic abnormalities associated with MDS were defined, and the diagnostic utility of flow cytometry was compared, with morphologic and cytogenetic evaluations in 20 difficult cases. Although morphology and cytogenetics were adequate for diagnosis in most cases, flow cytometry could detect immunophenotypic abnormalities in cases when combined morphology and cytogenetics were nondiagnostic. It is concluded that flow cytometric immunophenotyping may help establish the diagnosis of MDS, especially when morphology and cytogenetics are indeterminate. (Blood. 2001;98:979-987)

Adult↗
PubMed2001

Color Doppler velocity profile assessment of portal hemodynamics in cirrhotic patients with portal hypertension: correlation with esophageal variceal bleeding.

PURPOSE: Using the color Doppler velocity profile (CDVP), we investigated portal hemodynamics and their relationship with esophageal variceal bleeding (EVB) in patients with cirrhosis and portal hypertension. METHODS: The hemodynamics of the portal trunk, right anterior portal branch, and splenic vein were evaluated in 69 cirrhotic patients with portal hypertension and 46 healthy volunteers. The CDVP, a recently developed Doppler software, was used to measure blood flow velocity and flow volume; evaluate the spatial distribution of flow velocities in the cross-section of a vessel (velocity profile), as reflected by the profile parameter (n); and assess changes in flow volume over time (flow profile). The congestion index was calculated by dividing the cross-sectional area by the maximum cross-sectional velocity (CSVmax). The hemodynamic features were compared between patients without a history of EVB [EVB(-)] and those with a history of EVB [EVB(+)], and a logistic regression model was employed to identify factors associated with EVB. RESULTS: Compared with the healthy group, the cirrhotic group had a significantly lower mean CSVmax in the portal trunk and right anterior portal branch (both p < 0.01), a significantly elevated mean flow volume in the splenic vein and portal trunk (both p < 0.01), a significantly elevated mean ratio of splenic vein flow volume to portal trunk flow volume (SV/PT) (p < 0.001), and a significantly greater mean congestion index in the portal trunk, right anterior portal branch, and splenic vein (all p < 0.01). In the cirrhotic group, there was a significantly higher incidence of a flat flow pattern in the right anterior portal branch and a phasic flow pattern in the splenic vein than in the healthy group (both p < 0.01). Among cirrhotic patients, the EVB(+) group had a significantly greater mean flow volume in the splenic vein (p < 0.01), greater mean SV/PT (p < 0.01), greater mean spleen size (p < 0.05), and lower mean portal trunk n value (p < 0.05) compared with the EVB(-) group. Logistic regression analysis revealed that the SV/PT and portal trunk n value were independent EVB-related factors. CONCLUSIONS: The results suggest that portal hemodynamics in cirrhotic patients are characterized by passive congestion and increased blood flow. However, these 2 features had different preponderances in different parts of the portal venous system. Increased flow in the splenic vein may be the primary source of increased portal flow and may play a role in the development of EVB. The SV/PT and portal trunk n value may be valuable factors for predicting EVB.

Adolescent↗
PubMed2001

Hepatocellular carcinoma: US-guided percutaneous microwave coagulation therapy.

PURPOSE: To evaluate the use of percutaneous microwave coagulation therapy for hepatocellular carcinoma, particularly with tumor nodules larger than 2 cm in diameter. MATERIALS AND METHODS: Fifty patients with 107 hepatocellular carcinoma nodules (mean diameter, 2.7 cm +/- 1.5 [SD]; range, 0.8-6.4 cm) were treated with percutaneous microwave coagulation therapy. Single electrode insertion was used in 46 nodules (43.0%) 2 cm or smaller, whereas multiple electrode insertion was applied in 61 (57.0%) nodules larger than 2 cm. RESULTS: At 1 month after therapy, technical success for tumors 2 cm or smaller and those larger than 2 cm was achieved in 45 (98%) and 56 (92%) nodules, respectively. After follow-up of 9 months or longer, local recurrence was found in one nodule (2%) sized 1.8 cm and in five nodules (8%) larger than 2 cm. At the end of the study, 26 (52%) of 50 patients were free of disease, and disease-free survival rates at 1 and 2 years were 55% and 41%, respectively. Overall survival rates at 1, 2, and 3 years were 96%, 83%, and 73%, respectively. CONCLUSION: Percutaneous microwave coagulation therapy is an effective and safe therapeutic modality for hepatocellular carcinoma. A multiple electrode insertion technique can enhance the effectiveness of this therapy in tumors 6 cm or smaller.

Adult↗
PubMed2001

[Clinical study on therapeutic effects of treatment according to syndrome differentiation of traditional Chinese medicine combined with captopril on severe viral myocarditis complicated heart failure].

OBJECTIVE: To observe the therapeutic effect and mechanism of the treatment according to Syndrome Differentiation of TCM combined with captopril (CAP) on severe viral myocarditis (SVM) complicated heart failure (CHF). METHODS: One hundred and nine patients of SVM complicated CHF were randomly divided into the treated group (n = 72) and the control group (n = 37), the former was treated with TCM combined with CAP, while the latter was treated with dexamethasone and interferon. The TCM prescriptions were made depending on types of diseases by Syndrome Differentiation, i.e. Heart-Spleen deficiency type, Qi-Yin deficiency type and Spleen-Kidney Yang deficiency type. The efficacy of treatment was evaluated by the criteria including NYHA classification, myocardial enzymology, electrocardiogram, cardiac function and motorial toleration measured before and after treatment. RESULTS: The therapeutic effect of the treated group according to NYHA classification was obviously better than that of the control group; the creatine phosphokinase isoenzyme (CPK-MB), aspartate transaminase (AST), lactate dehydrogenase (LDH) content lowered in both groups, but more significantly lowered in the treated group than in the control group (P < 0.05, P < 0.01); the improvement of S-T segment of ECG in the treated group was better than that in the control (P < 0.01); also some parameters of heart function and motorial toleration were bettered in the treated group more significantly (P < 0.01). CONCLUSION: TCM treatment according to Syndrome Differentiation combined with CAP in treating SVM complicated CHF could elevate the clinical efficacy.

Adult↗
PubMed2000

Diagnosis of unexpected acute myeloid leukemia and chronic lymphocytic leukemia: a case report demonstrating the perils of restricted panels in flow cytometric immunophenotyping.

We report on the flow cytometric identification of concomitant acute myeloid leukemia and chronic lymphocytic leukemia in cytology specimens submitted with minimal clinical information. A 64-year-old man presented with fever and progressive dyspnea on exertion. Chest X-ray and computed tomography scan showed a left upper lobe pulmonary mass. Pulmonary capillary pullback specimens were collected to determine infectious verses neoplastic etiology. The pulmonary capillary pullback specimens showed atypical mononuclear cells with enlarged, slightly irregular nuclei; visible nucleoli; and basophilic cytoplasm. Flow cytometric analysis of the specimen for lymphoma was requested. Flow cytometric immunophenotypic studies showed that 78% of the cells were CD34 positive, CD45 dim positive and CD11c positive, consistent with acute myeloid leukemia. About 0. 75% of the cells expressed CD5 as well as dim CD20 and were monoclonal for kappa light chains: consistent with chronic lymphocytic leukemia/small lymphocytic lymphoma. At this time the clinician communicated a history of myelodysplastic syndrome of refractory anemia subtype. Peripheral blood was obtained for further immunophenotyping and the patient was immediately treated for his acute myeloid leukemia. This case demonstrates that a diagnostic antibody panel should allow evaluation of all cell types as per the U.S./Canadian consensus recommendations on the immunophenotypic analysis of hematologic neoplasia by flow cytometry (Stewart et al.: Cytometry 30:231-235, 1997). Published 2000 Wiley-Liss, Inc.

Acute Disease↗
PubMed2000

Development of lymphoproliferative disorder of granular lymphocytes in association with hairy cell leukemia.

Lymphoproliferative disorder of granular lymphocytes (LDGL) is a low grade T-cell disease characterized by clonal expansion of large granular lymphocytes of either T cell or natural killer (NK) cell lineage that express the cytotoxic T-cell/NK cell antigens CD16, CD56 and/or CD57. LDGL has been described in association with other malignancies, leading to theories of a common abnormal stem cell as well as development of the LDGL as an immune response to a primary tumor. We have studied 32 patients with hairy cell leukemia (HCL). In 15 patients (47%) we detected an increase in cells expressing cytotoxic T-cell/NK cell antigens. In 10(31%) patients these cells were of T cell lineage, while 5 patients (16%) had increased NK-cells. T cell clonality was detected by PCR in all cases with increased cytotoxic T-cells in which adequate DNA was obtained from peripheral blood. Since in 2 patients the LDGL was not present at diagnosis but developed during follow up, our data suggests that clonal LDGL may develop in response to the HCL. The significance of LDGL in the setting of HCL and flow cytometric evaluation of HCL versus LDGL will be discussed.

Adult↗
PubMed2000

[Construction and application of an Escherichia coli high effective expression vector with an enhancer].

In this study, we constructed a high effective fusion expression-vector in E. coli. This vector, pTO-T7, was characterized as: (1) an enhancer from tobacco mosaic virus (TMV), omega sequence, was ligated in front of a T7 promoter in the regulatory sequence; (2) the multi-cloning sites include eight restriction enzyme sites. It can facilitate fusion or nonfusion expression; (3) the N terminal of a fusion protein starts with the first 12 amino acids of T7 gene 10, and the C terminal is the hexahistidine tag; (4) kanmycin resistance gene was used as a selective marker. EGFP gene was inserted into pTO-T7 vector as a reporter gene. Expression data showed that fused-EGFP accounted to more than 50% of the total E. coli protein, and more than 90% of which was soluble. The fluorescence characters of fused-EGFP were also studied. The expression yield of target gene from plasmid pTO-T7 compared with that from pT-T7 without omega sequence suggested that omega sequence in pTO-T7 can improve the expression of target gene significantly.

Base Sequence↗
PubMed1999

Differential diagnosis of small polypoid lesions of the gallbladder: the value of endoscopic ultrasonography.

OBJECTIVE: To evaluate the accuracy of endoscopic ultrasonography (EUS) in making a differential diagnosis of small (< or =20 mm) polypoid lesions of the gallbladder. SUMMARY BACKGROUND DATA: Differential diagnosis of these lesions is often difficult using conventional imaging modalities. METHODS: The findings of EUS and transabdominal ultrasonography were retrospectively analyzed in 65 surgical cases of small polypoid lesions (cholesterol polyp in 40, adenomyomatosis in 9, adenoma in 4, and adenocarcinoma in 12). RESULTS: Polypoid lesions exceeding 10 mm suggested malignancy. EUS showed a tiny echogenic spot or an aggregation of echogenic spots with or without echopenic areas in 95% of patients with cholesterol polyps. EUS showed multiple microcysts or comet tail artifact in all adenomyomatosis cases. Adenomas and adenocarcinomas were not associated with the echogenic spots, microcysts, or artifacts. Among adenomas and adenocarcinomas, all sessile lesions were adenocarcinomas. EUS differentiated among polypoid lesions more precisely than ultrasonography (97% vs. 71%). CONCLUSIONS: A tiny echogenic spot or an aggregation of echogenic spots and multiple microcysts or comet tail artifact is pathognomonic for cholesterol polyp and adenomyomatosis, respectively. Polypoid lesions without these findings indicate adenoma or adenocarcinoma on EUS. Routine use of EUS is recommended for differential diagnosis of polypoid gallbladder lesions when ultrasonography shows no signs indicative of either cholesterol polyp or adenomyomatosis.

Adult↗
PubMed1998

Effect of intrauterine injection of chlorpromazin on implantation in the rat.

In rats, injection of chlorpromazin hydrochloride (CPZ), a calmodulin antagonist, to each uterine horn had a significant (87%) anti-implantation effect and 100% antifertility effect. Both of these rates were zero in the saline control group. Polyacrylamide gel electrophoresis analysis of the uterine fluid showed a decrease in the protein content and certain changes in its chemical composition, in particular, a marked reduction in the number of bands of estradiol-induced 70 kD proteins in the experimental group. No significant difference was found in the ovarian weight and the serum estradiol (E2) and progesterone (P) levels between the two groups. These results suggest that calmodulin influences the process of implantation and this effect is not directly related to the serum concentrations of E2 and P. It is believed that CPZ probably exerted its anti-implantation effect by a direct action on the uterus.

Animals↗
PubMed1996

Expression of TrkB receptor isoforms in the developing avian visual system.

The expression of novel TrkB receptor transcripts has been characterized to understand the potentially diverse roles of brain-derived neurotrophic factor (BDNF) in the developing avian visual system. In situ localization with an extracellular domain probe common to all TrkB transcripts labeled a sub-population of large retinal ganglion cells as well as many associated visual nuclei, including the neuronal layers within the tectum that receive retinal innervation. Because of the potential for structurally and functionally distinct receptors derived from the TrkB gene locus, cDNA cloning and reverse transcription-PCR analysis were used to further analyze receptor isoform expression in the retina and tectum. Receptor isoforms were sequenced that contained a deletion of the N terminus, a deletion in the putative ligand-binding domain, or a deletion in the cytoplasmic juxtamembrane (JM) domain. Two novel JM insertion sequences also were identified, one of which exhibits weak homology to beta-actin and was found in both kinase-containing (TK+) and kinase deletion (KD) receptor isoforms. In the developing retina, TK+ receptor mRNA is upregulated during the period of retinal ganglion cell (RGC) death, consistent with the proposed role of BDNF as a tectal-derived survival factor for RGCs. However, the expression of TK+ transcripts in the tectum indicates that this structure also contains cells responsive to BDNF throughout development. Because BDNF is expressed in both the retina and tectum, it is conceivable that TrkB also mediates autocrine/paracrine signaling within these structures or anterograde retinotectal trophic support.

Aging↗
PubMed1995

Portal vein embolization with ethanol injection via a fine needle in dogs.

We devised a method for portal vein embolization with ethanol injection (PVEEI) via a fine needle. Both the efficacy and safety of this procedure were evaluated in 28 dogs. An embolization of the left central and lateral lobes was undertaken with various doses of absolute (95%) ethanol. The smallest dose, 0.25 ml/kg ethanol (n = 7), caused the least damage to the liver, but the embolization was not complete. At the highest dose at 1.0 ml/kg, four of the seven dogs died of respiratory arrest; however, embolization was complete in the remaining dogs. All animals tolerated the procedure by 0.5 ml/kg ethanol (n = 11) with a satisfactory embolic effect, slight toxicity to the hepatic parenchyma, and only transient changes in liver function. The results suggested that PVEEI is safe and effective when a suitable dose of ethanol is administered. Local overembolization occurred in one dog due to extension of the thrombus, suggesting that the point of puncture should not be near the confluence of the branches. Since a selective portal venous puncture is not difficult to perform under sonographic guidance, PVEEI is expected to be clinically applied.

Animals↗
PubMed1995

Discordant P-glycoprotein antigen expression and transport function in acute myeloid leukemia.

Expression of the multidrug resistance efflux pump P-glycoprotein (Pgp) was measured in a series of AML patients using two flow cytometry methods. Transport function was assessed by measuring the modulating effect of the Pgp inhibitor cyclosporin A (CsA) on the cellular accumulation of daunorubicin, and Pgp antigen expression by surface immunofluorescence using the MRK-16 antibody. Both methods showed a wide range of values for Pgp expression between individual patients, but in contrast to a series of cell lines expressing Pgp there was no correlation between antigen expression and transport function in the clinical samples. As previously reported for chronic lymphocytic leukemia (CLL), pretreatment with neuraminidase markedly improved MRK-16 staining in some cases, indicating that abnormal glycosylation can cause epitope masking in AML blasts. Because experience with cell lines shows that Pgp expression is a continuous variable which correlates with the level of drug resistance, rather than the 'positive' or 'negative' which are frequently reported by clinical flow cytometry laboratories, we used a calibration procedure to estimate the actual number of Pgp molecules expressed in the AML samples. Despite the additional refinements of neuraminidase treatment and antigen quantification, the correlation between Pgp antigen expression and daunorubicin accumulation remained extremely weak (r = 0.11; P = 0.63). It is suggested that the assay for transport function can detect molecules that affect daunorubicin accumulation but are antigenically distinct from classical P-glycoprotein. Heterogeneity of multidrug resistance efflux pumps might in part explain the relatively weak prognostic significance of immunofluorescence detection of Pgp in AML patients.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1994

Metabolism of N-nitrosomethylbenzylamine by microsomes from perivenous and periportal hepatocytes.

Immunohistochemical studies have shown the presence of O6-methylguanine in the perivenous area but not the periportal area of the liver lobule following administration of N-nitrosomethylbenzylamine (NMBzA) to rats. This study was designed to investigate the hypothesis that hepatic heterogeneity of NMBzA metabolism determines the distribution of O6-methylguanine in the liver. Using microsomes prepared from purified perivenous and periportal hepatocytes, we showed that NMBzA debenzylase and demethylase activities were 2-fold and 1.5-fold higher, respectively, in perivenous than in periportal microsomes. Our results suggest that the combined effect of a higher rate of formation and lower rate of repair of O6-methylguanine in perivenous than in periportal hepatocytes could explain the localization of this base in zone 3 of the liver lobule following NMBzA treatment.

Animals↗
PubMed1992

Selective total vascular occlusion for major hepatic resection.

Selective total vascular occlusion for the resection of large tumors on the right lobe of the liver or central hepatic tumors was described. The occlusion of the portal triad, infrahepatic vena cava and the total hepatic circulation was selectively used in combination to control bleeding in the process of hepatectomy. Within a year, major resection was successfully performed with this technique on 10 patients (extended right lobectomy 4 patients, right lobectomy 4, central segmentectomy 2). The mean duration of total vascular exclusion was 19.35 +/- 19.32 minutes and mean blood transfusion requirement was 7 +/- 4.5 units during surgery.

Adult↗
PubMed1991

[RP-HPLC determination of 1-(p-methylphenyl-2-(2-piperidinoacetyl- 1,2,3,4-tetrahydroisoquinoline hydrochloride in rabbit plasma and its pharmacokinetic parameters].

A reversed phase high performance liquid chromatographic method (RP-HPLC) was developed for the determination of rabbit plasma levels of 1-(p-methylphenyl-2-(2-piperidinoacetyl)-1, 2, 3, 4-tetrahydroisoquinoline hydrochloride (70026), a new antiarrhythmic agent with promising prospects. Its pharmacokinetic parameters were obtained from the rabbit plasma level-time curve measured. 70026 plasma sample was determined by extracting with ether and 0.2 mol/L sulfuric acid, chromatographing on LiChrosorb RP-C18 column, and detecting at 230 nm. The mobile phase selected was methanol-water-triethylamine-phosphoric acid (63:37:1:0.8 v/v). The average recovery of the entire procedure from plasma was 99.94 +/- 3.10 (SD) %; the average CV of within-day and between-day were 4.12% and 3.95% respectively; the minimum detection limit was 3 ng; 70026 plasma concentration ranging from 25-2000 ng/ml yielded a good linear relationship with the peak area ratios, Y = 0. 002865X-0.01346, r = 0. 9999. No endogeneous interference was found in chromatograms of plasma sample. The purity of chromatographic peak of 70026 was identified and proved by mass spectrometry. In urine sample, the hydrolysate of 70026 was found as the original and bound forms. The rabbit plasma level of 70026 after intravenous administration versus time curve was found to be in correspondence with two-compartment model, T1/2 = 4.80 + 1.522 (h).

Animals↗
PubMed1991

Membrane resealing in cultured rat septal neurons after neurite transection: evidence for enhancement by Ca(2+)-triggered protease activity and cytoskeletal disassembly.

Neurites of cultured septal neurons were transected with a laser under sterile conditions, and the subsequent membrane resealing was assayed using a dye exclusion method. In agreement with findings in other preparations, Ca2+ enhanced resealing: in normal culture medium the percentage of lesioned neurons that resealed within 20-30 min after transection increased with increasing bath [Ca2+] over the range 10(-7) to 2 x 10(-3) M; about 75% of cells resealed in 2 mM Ca2+. Mn2+ and Sr2+ also enhanced resealing, but Mg2+ inhibited it. The percentage of resealing neurons was sensitive to agents known to alter the stability of cytoskeletal components. Agents that tend to disassemble microtubules and/or neurofilaments (e.g., colchicine, low-ionic-strength media) strongly promoted resealing, whereas treatments that tend to stabilize microtubules (taxol, Mg2+) inhibited resealing. Addition of exogenous proteases (papain, trypsin, or dispase) enhanced resealing, whereas inhibitors of cysteine proteases (including a specific inhibitor of calpain, a Ca-activated neutral protease) strongly inhibited resealing. Calmodulin inhibitors inhibited resealing, consistent with reports that calmodulin facilitates calpain-mediated proteolysis of fodrin, a component of the cortical cytoskeleton. Based on these results, we hypothesize that one of the major mechanisms involved in resealing is activation of endogenous proteases by Ca2+ entry into the injured neurite. The resulting changes in the cellular cytoskeleton might promote fusion and resealing of the cut ends of the plasma membrane by enhancing membrane mobility and/or by removing structures that normally prevent membrane-membrane contact.

Animals↗