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Biomedical subjects

Yi Wang

Publications and source records attributed to Yi Wang.

At least 217 records · Page 12Linked to original sources

[A brief history of diagnosis and treatment of primary aldosteronism.].

Primary aldosteronism is a clinical syndrome characterized by hypokalemia, suppressed activities of plasma renin and high urinary and plasma aldosterone levels in hypertensive patients. It was first defined and reported by Jerome W. Conn in 1955. From 1960s to early 1970s, its techniques of diagnosis and treatment were greatly improved by the availability of spironolactone, realization of the renin-angiotensin-aldosterone system, and progress in laboratory tests and adrenal venous sampling. In 1970s, notwithstanding the extensive application of modern imaging modalities, such as CT scanning, adrenal venous sampling and steroid analysis have remained to be the most accurate and reliable localization method. From 1980s, more and more patients with primary aldosteronism were screened out from the hypertensive population by plasma renin activity/plasma aldosterone concentration ratio and cured by surgical interventions; laparoscopic unilateral adrenalectomy has become the generally accepted golden standard of operation.

Adrenalectomy↗

[Focal nodular hyperplasia of the liver: a clinical study of 48 patients].

OBJECTIVE: To study the diagnosis and proper treatment of focal nodular hyperplasia (FNH) of the liver. METHODS: Forty-eight consecutive patients with FNH treated from 1998 to 2002 were analyzed. Clinical, pathologic, and preoperative imaging findings of FNH all proved surgically and pathologically were retrospectively reviewed. RESULTS: Most of the patients were asymptomatic and serum test was normal. Helical multiphasic liver CT and MR imaging demonstrated characteristic features in 25 patients. Histologically, characteristic scar-like tissues were found in 29 cases. The overall complication rate was 2.1% and there was no death. No recurrence was observed after follow-up of 4 years after operation. CONCLUSION: There is little evidence for an increased risk for FNH in people using modern oral contraceptives, while characteristic imaging features exist in helical multiphasic liver CT and MR imaging. Operation is the optimal treatment for FNH, but for proved FNH less than 5 cm and asymptomatic patients, close periodic followed up should be done.

Adolescent↗

[Expression of angiogenic factors and their clinical significances in acute myeloid leukemia].

BACKGROUND & OBJECTIVE: To investigate the expression of vascular endothelial growth factor (VEGF) & basic fibroblast growth factor (bFGF) in primary acute myeloid leukemia (AML) cells, and study plasma VEGF& bFGF concentration in patients with AML and the two factors' clinical significance. METHODS: VEGF&bFGF and their receptors mRNA expression were detected by RT-PCR; VEGF & bFGF plasma level was analyzed by ELISA. RESULTS: In 107 AML patients, the positive mRNA expression rate of VEGF, KDR and Flt1 was 56.1%, 49.5%, and 2.8%, respectively; for bFGF and FGFR1-4, the positive rate was 21.5%, 35.5%, 9.4%, 35.5% and 23.4%, respectively. VEGF concentration in AML (154.75+/-109.98) pg/ml was significantly higher than that in AML-CR (72.05+/-23.39) pg/ml and the normal control (99.91+/-41.87) pg/ml (P< 0.05). Nevertheless, the level of bFGF had no significant difference among AML, AML-CR and the normal control. VEGF level (124.05+/-76.57) pg/ml in patients, who got complete remission (CR) after 2 cycles of chemotherapy, was remarkably lower than that (211.243+/-169.88) pg/ml in patients without CR (P< 0.05). Furthermore, the higher the concentration of VEGF & bFGF, the shorter the survival was. CONCLUSION: VEGF& bFGF and their receptors mRNA in leukemic patients could be expressed to some degree,and our investigation suggested VEGF &bFGF and their receptors probably be produced by autocrine or paracrin. Abnormally high level of VEGF may be a poor factor for chemotherapy and survival in AML. The prognosis of patients with AML may be improved by treating VEGF and their receptors as therapy targets.

Acute Disease↗

[Expression of wild type and variant estrogen receptors in human hepatocellular carcinoma].

OBJECTIVE: To investigate the expression of wild type estrogen receptor (wER) and the exon-5 deleted ER (variant ER, vER) in human hepatocellular carcinoma (HCC) samples, and thereafter analyze the possibility of HCC treatment by endocrine therapy. METHODS: The mRNA expressions of wER and vER were analysed from 28 cases of HCC by RT-PCR. The expression of ER at the protein level was detected by immunohistochemistry (IHC). RESULTS: IHC results showed that 39.3% of the HCC specimens expressed ER. The mRNA of wER was detected in 89.3% (25/28) of the HCC specimens while that of vER was detected in 96.4%(27/28). Twenty four out of 28 HCC cases (85.7 %) expressed both wER and vER. One out of 28 patients (3.5%) expressed only wER whereas 3 patients out of 28 (10.7%) expressed vER only. CONCLUSION: Ninety six percent(27/28) of the HCC patients expressed vER,which suggests that the expression of vER is an important event in the development of HCC.

Adult↗

[Clinical review of cochlear implant in 533 cases].

OBJECTIVE: To summarize and analyze the etiology, surgical indications, operation methods and outcomes of cochlear implantation. METHODS: 533 cases (534 ears) with severe and profound hearing loss received cochlear implant, 489 were pre-lingual deafness and 38 cases were post-lingual deafness. Their ages at implant, 1 to approximately 3 were 167, approximately 5 were 77, approximately 7 were 73, approximately 14 were 136, approximately 17 were 28, >17 were 52. 76 cases (14. 3%) were found the middle and inner ear malformations. That included Mondini 26 in cases, Common cavity in 10 cases and Large vestibule aqueduct syndrome in 20 cases. The average pure tone threshold were 105.5 dB HL, ABR threshold were >95 dB nHL and 40 Hz threshold in 500 Hz were 101.7 dB. The devices they used were Nucleus 22M in 27 ears, 24M in 308 ears, 24R Contour in 131 ears and 24R ST in 21 ears; Med El C40+ in 44 ears; Clarion CI in 3 ears. Facial recess approach was performed in normal cases, and in Common cavity cases horizontal semicircular canal approach was used. Preoperative hearing and speech evaluations were done in most cases. RESULTS: In 26 Mondini case, gusher were happened in 20 cases. The insertion depth in normal cases: Nucleus were 30 bands, Med El were 31 mm. In Mondini cases, Nucleus were 28 bands. In Common cavity cases, Nucleus were 26 bands. Of 533 cases, The average of open set sentences discrimination of post-lingual deafness was 70%, the satisfaction rate of questionnaire for pre-lingual deafness under 17 years old was 94.7%. CONCLUSIONS: Cochlear implant is a useful method to restore the hearing of the patients with severe and profound hearing loss. It is important for the outcomes with proper preoperative assessment, surgery and postoperative speech and hearing evaluations.

Adolescent↗

[Determination of chemical components in tobacco leaves by FT-NIR spectroscopy: study of influence of spectral ranges on PLS modeling].

NIR spectra of tobacco leaves were measured in the range of 12000 to 4000 cm(-1) using a Bruker MPA FT-NIR spectrometer. PLS calibration models were developed and optimized for rapid quantitative analysis of nicotine alkaloids, total sugar and total nitrogen contents in tobacco leaves. It was found that the prediction errors of the same component were significantly different when different spectral regions were used for PLS modeling, and the best spectral range is also different for each component. The study demonstrated that wavelength range selection is one of the important keys to optimizing the NIR calibration model. In this study it was found that the optimized calibration ranges for nicotine alkaloids, total sugar and total nitrogen are 9500-4231.2 cm(-1), 7502.1-4246.7 cm(-1) and 7502.1-4597.7 cm(-1), respectively. The Root Mean Square Error of Cross Validation (RMSECV) of the three calibration models are 0.081 5, 0.808 and 0.056, respectively.

Algorithms↗

[Synthesis of 2-(4-dimethylaminophenyl)-5-fluoro-6-(morpholin-4-yl)-1H-benzimidazole and its spectroscopic research].

A new potential pharmaceutical compound, 2-(4-dimethylaminophenyl)-5-fluoro-6-(morpholin-4-yl)-1H-benzimidazole (4) was synthesized. The effect of the pH value of aqueous solution on the absorption spectrum of compound 4 and its interaction with beta-cyclodextrin (beta-CD) were investigated by UV-Vis spectrum, steady-state fluorescence and time-resolved spectroscopic measurements. The results indicate that compound 4 mainly exists in neutral molecular state when pH value of the aqueous phase is above 7.0. In the pH range from 7.0 to 3.8 the neutral molecular state and protonated univalent cationic form coexist. As the pH value decreases, the content of univalent cationic form increases. When 2.76 < pH < 3.8, the protonated univalent cationic form is the predominant species. With further decrease of the pH value, the univalent cation is protonated by another H+ to form a bivalent cation, and both univalent and bivalent cations coexist in the solution. The steady-state fluorescence and time-resolved spectroscopic measurements revealed that compound 4 is a sensitive molecular probe. The interaction of compound 4 and beta-CD is very strong. The guest:host ratio of inclusion complex between compound 4 and beta-CD formed in the aqueous solution (pH = 9.50) is 1:1, and the association constant was determined to be (1.02 +/- 0.04) x 10(3) mol x L(-1).

Absorption↗

Application of ultrasonic to speciation analysis of heavy metals in soil.

In order to reduce the operation time and improve the extraction efficiency, ultrasonic energy by means of ultrasonic bath was used to the modified Tessier sequential extraction for speciation analysis of heavy metals in soil. Extractable contents of Cu, Fe, Mn, Ni, Pb and Zn were measured by atomic absorption spectroscopy (AAS). The merit of the ultrasonic extraction (UE) applied to the modified Tessier method is not only that the operation time for the first 4 fractions was reduced from ca. 18 h to 8 h, comparing with conventional extraction (CE), but also the extraction efficiency was higher. The results for both of UE and CE were consistent. The extractable Cu, Ni and Zn in the sample No. 1 were mainly associated with the third fraction (Fe-Mn oxides fraction), and fourth fraction (organic matter fraction) in the sample No.2. The extractable Fe and Mn were all mainly associated with the third fraction, and Pb the fourth fraction in both of the samples. The effects of concentration of hydroxylamine chloride on the capability for the extraction of studied metals were also studied.

Environmental Monitoring↗

[Imaging diagnosis of carotid cavernous fistula].

OBJECTIVE: To evaluate the value of ultrasonography, CT, MRI and digital subtraction angiography (DSA) in the diagnosis of carotid cavernous fistula (CCF). METHODS: Twenty-eight cases of CCF patients were examined with ophthalmologic A/B echography and DSA, part of them were examined by one or several items among color Doppler imaging, CT and MRI. RESULTS: Ultrasonography could determine the enlarged ophthalmic vein with signal of blood stream and could detect the pulsation synchronizing with the pulse. CT and MRI could display the enlargement and abnormality of cavernous sinus. DSA could reveal fistulas supplied by internal carotid artery directly or by the dual branches of the carotid artery. The latter included meningohypophyseal trunk, capsular artery, middle meningeal artery, accessory meningeal artery, ascending pharyngeal artery and the artery of the foramen rotundum, etc. The drainage pathway of fistula included ophthalmic vein, inferior petrosal sinus, intercavernous sinus, sylvian vein and cortical drainage, etc. CONCLUSIONS: Each method of examination has its own advantages, combining of various methods can lead to an accurate diagnosis of CCF. DSA is the "golden standard" which can display supplying artery and the drainage pathway.

Adolescent↗

A single amino acid change (Asp 53 --> Ala53) converts Survivin from anti-apoptotic to pro-apoptotic.

Survivin is a member of the inhibitor of apoptosis protein (IAP) family that has been implicated in both apoptosis inhibition and cell cycle control. Recently, Survivin has attracted growing attention because of its tumor-specific expression and potential applications in tumor therapy. However, its inhibitory mechanism and subcellular localization remain controversial. Here, we report a novel Survivin mutant Surv-D53A, which displays a function opposite to Survivin and a distinctive subcellular distribution compared with its wild-type counterpart. Surv-D53A was shown to induce apoptosis in a p53-independent manner, indicating that tumor suppressor p53 is not involved in its apoptosis pathway. Surv-D53A was shown to markedly sensitize apoptosis induced by TRAIL, doxorubicin, and RIP3. We also demonstrated that similar to wild-type Survivin, Surv-D53A was localized in cytoplasm in interphase and to midbody at telophase. However, it fails to colocalize in chromosomes with Aurora-B in metaphase as wt-Survivin. Surv-D53A mutant is less stable than wt-Survivin and is degraded more rapidly by ubiquitin-proteasome pathway. Additionally, we found that Surv-D53A interacts with wt-Survivin to form heterodimer or with itself to form mutant homodimer, which may account for the loss of its antiapoptotic function. Finally, unlike Survivin*Survivin, neither Surv-D53A*Survivin nor Surv-D53A*Surv-D53A is able to bind to Smac/DIABLO, which may explain the underlying mechanism for its abolishment of antiapoptotic activity of Survivin.

Amino Acid Sequence↗

A member of the Pyrin family, IFI16, is a novel BRCA1-associated protein involved in the p53-mediated apoptosis pathway.

We identified IFI16 as a BRCA1-associated protein involved in p53-mediated apoptosis. IFI16 contains the Pyrin/PAAD/DAPIN domain, commonly found in cell death-associated proteins. BRCA1 (aa 502-802) interacted with the IFI16 Pyrin domain (aa 1-130). We found that IFI16 was localized in the nucleoplasm and nucleoli. Clear nucleolar IFI16 localization was not observed in HCC1937 BRCA1 mutant cells, but reintroduction of wild-type BRCA1 restored IFI16 nuclear relocalization following IR (ionizing radiation). Coexpression of IFI16 and BRCA1 enhanced DNA damage-induced apoptosis in mouse embryonic fibroblasts from BRCA1 mutant mice expressing wild-type p53, although mutant IFI16 deficient in binding to BRCA1 did not induce apoptosis. Furthermore, tetracycline-induced IFI16 collaborated in inducing apoptosis when adenovirus p53 was expressed in DNA-damaged p53-deficient EJ cells. These results indicate a BRCA1-IFI16 role in p53-mediated transmission of DNA damage signals and apoptosis.

Apoptosis↗

MSH2 and ATR form a signaling module and regulate two branches of the damage response to DNA methylation.

The mismatch repair proteins function upstream in the DNA damage signaling pathways induced by the DNA methylating agent N-methyl-N'-nitro-N-nitrosoguanidine (MNNG). We report that MSH2 (MutS homolog 2) protein interacts with the ATR (ATM- and Rad3-related) kinase to form a signaling module and regulate the phosphorylation of Chk1 and SMC1 (structure maintenance of chromosome 1). We found that phosphorylation of Chk1 by ATR also requires checkpoint proteins Rad17 and replication protein A. In contrast, phosphorylation of SMC1 by ATR is independent of Rad17 and replication protein A, suggesting that the signaling pathway leading to SMC1 phosphorylation is distinct from that mediated by the checkpoint proteins. In addition, both MSH2 and Rad17 are required for the activation of the S-phase checkpoint to suppress DNA synthesis in response to MNNG, and phosphorylation of SMC1 is required for cellular survival. These data support a model in which MSH2 and ATR function upstream to regulate two branches of the response pathway to DNA damage caused by MNNG.

Ataxia Telangiectasia Mutated Proteins↗

Platelet-derived growth factor receptor-mediated signal transduction from endosomes.

Although accumulated evidence supports the concept of endosomal signaling of receptor tyrosine kinases, most results are generated from studies of epidermal growth factor receptor (EGFR). It is not clear whether the concept of endosomal signaling could be generally applied to the other receptor tyrosine kinases. For example, platelet-derived growth factor receptor (PDGFR) is very similar to EGFR in terms of both signaling and trafficking; however, little is known about the endosomal signaling of PDGFR. In this research, we applied the same approaches from our recent studies regarding EGFR endosomal signaling to investigate the endosomal signaling of PDGFR. We showed in this communication that we are able to establish a system that allows the specific activation of endosome-associated PDGFR without the activation of the plasma membrane-associated PDGFR and without disrupting the overall endocytosis pathway. By using this system, we showed that endosomal activation of PDGFR recruits various signaling proteins including Grb2, SHC, phospholipase C-gamma1, and the p85alpha subunit of phosphatidylinositol 3-kinase into endosomes and forms signaling complexes with PDGFR. We also showed that endosomal PDGFR signaling is sufficient to activate the major signaling pathways implicated in cell proliferation and survival. Moreover, we demonstrate that endosomal PDGFR signaling is sufficient to generate physiological output including cell proliferation and cell survival.

Adaptor Proteins, Signal Transducing↗

[A survey of the long-term incidence rate of benign prostate hyperplasia after vasectomy].

OBJECTIVE: To study the relationship of the long-term incidence rate of benign prostate hyperplasia (BPH) after vasectomy to age and time after operation. METHOD: Questionnaire survey, physical examination, and ultrasonography were conducted among 850 healthy males, aged 55 - 76 who underwent vasectomy more than 20 years before and 390 healthy males, aged 53 - 75, who had not undergone vasectomy in Yichang, Hubei province, selected by randomized cluster sampling. The data such as international prostate symptom scoring (IPSS), quality of life (QOL) index, maximum urine flow rate (MFR), and average flow rate (AFR), digital rectal examination (DRE), volume of prostate gland (V), and residual urine (R) were analyzed. RESULTS: The general BPH incidence rate of the vasectomy group was 10.8%, significantly lower than that of the control group (40.8%, P < 0.01). The age-specific BPH incidence rates in the vasetomy group were all significantly lower than those of the control group, especially that of the subjects aged over 70 (10.8% vs. 56.5%, P < 0.001). The BPH incidence rate of those who had undergone vasectomy 25 years or over before was 7.8%, significantly lower than that of those who had undergone vasectomy 20 years before (13.2%, P < 0.05), but not significantly difference from that of those who had undergone vasectomy 30 years or over before (5.5%, P > 0.05). The volumes of prostate gland in all age subgroups were significantly smaller in the vasectomy group than in the control group. CONCLUSION: Vasectomy reduces the incidence rate of BPH significantly.

Age Factors↗

[Adenoviral vector expressing an antiangiogenic fragment of thrombospondin 1 inhibits the growth of K562 cell xenografts].

OBJECTIVE: To explore the effect of adenovirus-mediated delivery of an antiangiogenic fragment of human thrombospondin 1 (TSP1(f)) on K562 cell growth in nude mice. METHODS: TSP1(f) cDNA was amplified by RT-PCR from normal human peripheral blood mononuclear cells and was used as transgene to construct a adenoviral vector (ADV-TSP1(f)). Human leukemia K562 cells were cultured and infected with ADV-TSP1(f) or ADV-LacZ. PBS was used as control. TSP1(f) expression/secretion by these infected K562 cells was demonstrated using Western blot analysis. MTT assay was performed to determine the effect of ADV-TSP1(f) infection on K562 cell growth kinetics. Eighteen female Balb/c nude mice were inoculated subcutaneously with human leukemia K562 cells. When the diameter of the tumor reached 5 approximately 7 mm the rats were randomly divided into 3 groups of 6 rats injected intratumorally with ADV-TSP1(f), ADV-LacZ, and PBS respectively. The volume of K562 xenografts was measured every three days during the 3-week treatment. By the end of the 21st day the mice were killed and the tumors were taken to undergo histological examination. The intratumoral microvessel density (MVD) was determined by immunohistochemical staining. RESULTS: TSP-1f was expressed and secreted efficiently by ADV-TSP1(f)-infected K562 cells. Three weeks after the initial treatment, the volume of K562 xenografts in the mice treated with ADV-TSP1(f), ADV-LacZ, and PBS was (1,108 +/- 179) mm(3), (4,518 +/- 452) mm(3), and (4,666 +/- 458) mm(3) respectively (P < 0.01). The number of CD31+ microvessels counted per x200 field was 34 +/- 9, 36 +/- 7, and 14 +/- 4 in the tumors treated with PBS, ADV.LacZ, and ADV.TSP-1f respectively (P < 0.001). CONCLUSION: Adenovirus-mediated TSP-1f gene transfer greatly inhibits K562-derived tumor growth and angiogenesis in mouse xenograft model, and may serve as a new therapy for hematological malignancies.

Adenoviridae↗