PubMed Health⌕ Search

Biomedical subjects

H Bai

Publications and source records attributed to H Bai.

At least 37 records · Page 2Linked to original sources
PubMed2001

[The MRI diagnosis of aortic dissection].

OBJECTIVE: To analyze and address the MRI manifestations and diagnostic importance of aortic dissection. METHODS: The MRI manifestations in 31 cases of aortic dissection were analyzed retrospectively. Sixteen cases were proved by operation and pathology. RESULTS: MRI depicted an intimal flap and a double lumen in all 31 patients. The site of intimal tear was located in 7 cases. Also demonstrated were the complications: aortic dilation in 15 cases, aortic branches involvement in 5, thrombus formation in the false lumen in 5, aortic regurgitation in 10, left ventricle hypertrophy in 10, and leak into thorax in 2. CONCLUSION: As a non-invading imaging method, MRI can demonstrate the site, range and complications of aortic dissection; it is very valuable in the diagnosis of aortic dissection.

Adult↗
PubMed2001

[The paraoxonase Gln-Arg192 polymorphism in patients with coronary heart disease in Chinese population].

OBJECTIVE: To investigate the 192 Gln-Arg polymorphism of paraoxonase (PON) gene and its relationship with serum lipids levels in patients with coronary heart disease in Chinese population. METHODS: The genotype and allele frequency of paraoxonase gene 192 Gln-Arg polymorphism was assayed by polymerase chain reaction (PCR)-restriction fragment length polymorphism (RFLP). Serum lipids were measured by enzymatic kits in 118 CHD patients and 128 healthy subjects whose fasting serum TG levels were < 1.82 mmol/L and TC levels < 6.2 mmol/L from a population of Chinese Han nationality in Chengdu area. RESULTS: Both in CHD group and control group, the QR genotype of PON gene was the major one, and its frequencies were 0.578 and 0.525 respectively. No differences were found in PON gene Gln-Arg polymophism in the CHD group when compared with the control group. The frequency of R allele of PON gene in Chinese was significant higher than that in European and American Caucasians (0.51 vs. 0.26-0.31, P < 0.01) and Indian (0.51 vs. 0.17, P < 0.01), and significantly lower than that in Japanese (0.51 vs. 0.65, P < 0.01). CONCLUSION: These results suggested that the Gln-Arg192 polymorphism of the PON1 gene was not associated with coronary heart disease in Chinese population.

Aged↗
PubMed2001

[Roles of Galphaq/11 mediated- and platelet-derived growth factor mediated-signal transduction pathways in rat aorta restenosis].

To observe the roles of Galphaq/11 mediated- and platelet-derived growth factor (PDGF) mediated-signal transduction pathways in proliferation and migration of vascular smooth muscle cells (VSMC) after arterial injury, a vascular cell proliferation model was established by balloon injury in rat aorta and the morphologic changes in injured vascular walls after the injury were studied. Activities of angiotensin converting enzyme (ACE) and aorta phospholipase C (PLC) were tested, and levels of platelet-derived growth factor receptor-beta (PDGFR-beta) and Galphaq/11 protein were measured by Western blot analysis. At l day after operation, injured aortic segments showed denudation in endothelial cells. Medial VSMC proliferation and intimal hyperplasia were not observed. As compared with the sham group, ACE activities were increased by 382.7 percent; (P<0.0l), but the expression of PDGFR-beta and PLC activities did not show significant changes (P>0.05). In addition, the level of Galphaq/11 protein was decreased by 20.0 percent; (P<0. 05). At l4 days after operation, sections of injured aorta showed marked intimal thickening with large numbers of VMSCs proliferating throughout intima and media. In comparison with the sham group, ACE activity, PLC activity and the level of PDGFR-beta were increased by 420.2 percent; (P<0.01), 186.2 percent; (P<0.05) and 85.0 percent; (P<0.05), respectively. While the level of Galphaq/11 protein was decreased by 33.1 percent; (P<0.01). The above data suggest that the PDGF-mediated signal transduction pathway plays an important role in VSMC proliferation.

Angioplasty, Balloon↗
PubMed2001

[Apolipoprotein C III gene Sst I polymorphism in patients with endogenous hypertriglyceridemia in Chinese population].

OBJECTIVE: To investigate the apoC III gene Sst I polymorphism and its relationship with serum lipids and apolipoproteins (apo) levels in patients with endogenous hypertriglyceridemia in Chinese population. METHODS: The genotype and allele frequency of apoC III gene Sst I polymorphism was assayed by polymerase chain reaction (PCR)-restriction fragment length polymorphism (RFLP). Serum lipids were measured by enzymatic kits and apolipoproteins A I, A II, B100, C II, C III and E were measured by RID kits developed by Apolipoprotein Research Unit of WCUMS in 176 HTG patients whose fasting serum TG levels were > or = 2.26 mmol/L and in 199 healthy subjects whose fasting serum TG levels were < 1.82 mmol/L and TC levels < 6.2 mmol/L from a population of Chinese Han nationality in Chengdu area. RESULTS: In both HTG group and control group, S1 allele was the major allele and homozygous S1S1 genotype was the most frequent one. The frequency of S2 allele was significantly higher than that reported in Caucasians (0.289 vs 0.06-0.16, P < 0.05). No differences were found in apoC III gene Sst I polymophism in the HTG group when compared with the control group (0.287 vs 0.289, P > 0.05). The genotype of S2S2 was not associated with higher TG and apolipoproteins levels when compared with the genotypes of S1S1 and S1S2 (P > 0.05). CONCLUSION: These results suggest that the Sst I polymorphism of the apoC III gene was not associated with endogenoushypertriglyceridemica in Chinese population.

Adult↗
PubMed2001

[Study on apoE gene polymorphism in Chinese type II b hyperlipidemia].

OBJECTIVE: To study apolipoprotein(apo) E polymorphism and its relationship with plasma lipids and apolipoproteins levels in Chinese patients with type II b hyperlip oproteinemia. METHODS: apoE genotypes were assayed by polymerase chain reaction (PCR)-restriction fragment length polymorphism (RFLP) method, serum lipids were determined by enzyme method, and apolipoproteins were measured by radial immunodiffusion assay in 74 type II b hyperlipidemia patients whose fasting serum lipids levels were TG > or = 2.26 mmol/L, TC > or = 6.21 mmol/L and in 230 healthy subjects whose fasting serum lipids levels were TG < 1.82 mmol/L, TC < 6.21 mmol/L from a population of Chinese Han nationality in Chengdu area. RESULTS: Compared with the control group, the serum TG, TC, LDLC, nHDLC, apoA II, apoB100, apoC II, apoC III, apoE levels and TG/HDLC ratio in patients with type II b hyperlipidemia were significantly increased(P < 0.001), and the serum HDLC levels and apoE/apoC III ratio were significantly decreased (P < 0.05). ApoE3/3 genotype and allele epsilon 3 frequency in type II b hyperlipidemia group and control group were both the highest. In type II b hyperlipidemia group, allele epsilon 2 frequency tended to increase and allele epsilon 4 frequency tended to decrease as compared with those in the control group (P > 0.05). In type II b hyperlipidemia group the genotype of apoE2 was associated with higher serum TG, apoC II, apoE levels and apoE/apoC III ratio when compared with the genotype of apoE3; the genotype of apoE4 was associated with higher serum TC, nHDLC and apoE levels when compared with the genotypes E3 and E2 (P < 0.001). CONCLUSION: The alleles epsilon 2 and epsilon 4 are associated with serum TG, TC, nHDLC, apoC II and apoE levels to some extent in type II b hyperlipide in Chinese population.

Adult↗
PubMed2000

ThinPrep Pap Test promotes detection of glandular lesions of the endocervix.

The objectives of this study were to evaluate 1) the detection rate of atypical glandular cells of undetermined significance of endocervical cell type (AGUS-EC) and 2) the correlation between AGUS-EC on cytology and biopsy results using the conventional Papanicolaou (Pap) smear test vs. the ThinPrep Pap test (TPPT). Cervical-vaginal samples processed by the conventional Pap smear for 11 mo in 1996-1997 were identified, as were TPPTs collected for the same interval in 1997-1998. Biopsy results were compared after a 9-mo follow-up for both groups. There were 112 AGUS-EC cases from 82,754 conventional Pap smears (detection rate, 0.14%) compared with 58 cases from 82,252 TPPTs (detection rate, 0.07%) (P < 0.01). Biopsies were available in 72 of 112 patients from the conventional Pap smear group and 35 of 58 patients from the TPPT groups. Five dysplastic glandular lesions/ AIS were diagnosed by biopsy in the 35 patients (14.3%)from the TPPT group, compared with 2 of the 72 patients (2.8%) from the conventional Pap smear group (P < 0.05). There were no statistically significant differences between other follow-up diagnoses for the two methods. The use of TPPT resulted in fewer cases of AGUS-EC and better correlation with histology. The TPPT appears to be as sensitive as and more specific than the conventional Pap smear for detection of endocervical glandular lesions.

Adolescent↗
PubMed2000

Hypotetraploidy in a patient with small cell carcinoma.

While numerical and structural chromosomal abnormalities characterize many hematopoietic and nonhematopoietic malignancies, the occurrence of polyploidy is by and large rare. We report here an interesting patient with small cell carcinoma (SCC) and hypotetraploidy initially referred to us because of a question of acute nonlymphocytic leukemia, M3 subtype, with a question of a 15;17 translocation characteristic of acute promyelocytic leukemia. However, the patient did not have a 15;17 translocation and the final hematopathologic analysis of the bone marrow aspirates and immunohistochemistry studies subsequently revealed the patient to have SCC. Small cell carcinoma is a highly malignant and a very aggressive neoplasm. A review of the literature, using Medline, Cancerlit, and the Science Citation Index, revealed that in most, if not all, reports, the presence of polyploidy is noted as a rare entity. In leukemia, reports of polyploidy point to a distinct category of patients with a poor risk for which more intensive treatment is needed. Limited information is currently available to assess the risk of polyploidy in small cell carcinoma. Our case is important not only because of the relative rarity of polyploidy, but also because insights gained from the study of this and other similar patients may help shed additional light on the mechanism of carcinogenesis, which is not fully known to date. As polyploidization is a manifestation of genetic instability and as genetic instability has been implicated in the genesis and progression of many cancers, it is perhaps not too surprising that polyploidy in our case was associated with a poor disease outcome. The patient has since expired.

Bone Marrow Neoplasms↗
PubMed2000

Effects of scanning and reconstruction parameters on image quality in electron-beam CT angiography: coronary artery phantom study.

RATIONALE AND OBJECTIVES: This study compared the image quality obtained with different scanning and reconstruction parameters for electron-beam computed tomographic (CT) angiography and sought optimal methods for visualizing the coronary artery lumen. MATERIALS AND METHODS: Electron-beam CT angiography with contrast material enhancement was used to image 35 branches of fresh postmortem swine coronary arteries. Different collimation widths, fields of view (FOVs), reconstruction kernels, and algorithms were employed to reconstruct the acquired raw data into CT angiographic images. Image quality was compared and analyzed. RESULTS: The contrast-to-noise ratios (C/Ns) for 1.5-, 2-, and 3-mm section thickness were 28.4 +/- 15.2, 31.9 +/- 9.3, and 33.8 +/- 14.5, respectively (P < .05). The lengths of visualized coronary artery lumina were significantly longer for 1.5-mm scanning (71.6 mm +/- 4.3) than for 2-mm (58.3 mm +/- 5.5) and 3-mm scanning (59.0 mm +/- 8.0) (P < .01). The C/Ns for 12.7-, 18.0-, and 26.0-cm FOV reconstruction were 32.8 +/- 9.9, 28.9 +/- 8.2, and 27.1 +/- 8.2, respectively (not significant), and the visualized luminal lengths were 76.1 mm +/- 12.5, 71.7 mm +/- 14.6, and 65.4 mm +/- 13.1, respectively (not significant). The highest C/N (48.2 +/- 13.3) was achieved with smooth kernels and a cone-beam algorithm, and the lowest (14.7 +/- 3.4) with very sharp kernels and a normal algorithm. Cone-beam algorithm images had significantly higher C/Ns than did normal algorithm images (P < .001), and they demonstrated longer coronary artery lumina (P < .01). CONCLUSION: Collimation width, FOV, reconstruction kernels, and algorithms are important in the processing of high-quality electron-beam coronary angiograms. A 1.5-mm collimation width, 12.7-cm FOV, cone-beam reconstruction algorithm, and very sharp kernels should help in obtaining the best image quality and depicting the longest segments of coronary artery lumen.

Algorithms↗
PubMed2000

Performance of the annular denuder system with different arrangements for HNO3 and HNO2 measurements in Taiwan.

Experiments on different annular denuder system (ADS) arrangements for sampling nitrous acid (HNO2) and nitric acid (HNO3) gases were conducted in this study to evaluate their sampling artifacts. The evaluation basis is the one that employed one sodium chloride denuder for sampling HNO3 gas and two sodium carbonate (Na2CO3) denuders for sampling HNO2 gas, which is a commonly employed ADS arrangement in many field applications in the United States. A field study was conducted in Hsinchu, Taiwan, and the results indicated that this ADS arrangement may yield over 80% relative errors for HNO3 gas. It also showed that the relative errors for HNO2 gas can be less than 10% as sampled with only one Na2CO3 denuder. This is attributed to the fact that the ambient HNO3 concentration measured in this study was relatively low while the HNO2 concentration was high, as compared to typical concentrations of these two gases measured in the United States. The sampling error of HNO3 gas may be due to high concentrations of N-containing interfering species present in Taiwan's atmosphere. Because the relative sampling errors of HNO3 and HNO2 gases depend mainly on their concentrations in the atmosphere as well as concentrations caused by interfering species, the risk for high error while measuring low HNO2 concentrations by only one Na2CO3 denuder is also possible. As a result, it is suggested that pretests are necessary to evaluate possible sources and degrees of sampling errors before field sampling of HNO2 and HNO3 gases. The sampling errors of these two gases can, therefore, be minimized with a better arrangement of the ADS.

Air Pollutants↗
PubMed2000

Evaluation of electron beam tomographic coronary arteriography with three-dimensional reconstruction in healthy subjects.

In this study, the authors evaluated the performance characteristics of contrast-enhanced electron-beam tomography (EBT) with three-dimensional reconstruction in defining the coronary artery lumen in healthy subjects. Thirty patients with normal coronary angiograms by selective coronary arteriography (SCA) underwent contrast-enhanced EBT examination. Measured parameters included degree of luminal enhancement, intravascular contrast-to-noise ratio (CNR), and diameter and length of visualized lumen. Ventricular cavity, aortic blood pool, and coronary artery attenuation were found to be significantly different before and after intravenous injection of contrast material (p < 0.001). CNR decreased from proximal to distal segments within each vessel (p < 0.001), with a peak of 11.2 +/- 2.3 occurring in the proximal left anterior descending coronary artery (LAD) to a low of 4.8 +/- 2.0 in the distal left circumflex (LCX). Luminal diameters visualized by EBT had no significant difference with that of SCA (p > 0.05). Therefore, EBT angiography with three-dimensional reconstruction allows for noninvasive coronary arteriography revealing long segments of the major coronary arteries in normal subjects.

Adult↗
PubMed2000

Detection and analysis of intracoronary artery stent after PTCA using contrast-enhanced three-dimensional electron beam tomography.

We evaluated several three-dimensional methods of contrast-enhanced electron beam tomography (EBT) for evaluation of intracoronary stent characteristics after percutaneous transluminal coronary angioplasty (PTCA). Twenty-six patients who had undergone PTCA and stenting (31 stents) were investigated by using contrast-enhanced, electrocardiographically (ECG) triggered EBT scanning. EBT results were compared with conventional selective coronary arteriography (SCA). Overall, 27 intracoronary stents had been identified on EBT images (87.1%), while 4 stents could not be evaluated because of impaired image quality. EBT correctly identified the only case in which there was a residual stenosis at the distal portion of the stent. As compared with SCA results, EBT showed an over-estimation of intracoronary stent diameter (p < 0.001) and accurate measurement on the visualized length of the stents (p > 0.05). Fifty Hu, 100 Hu and 150 Hu were used as the observed window levels on three-dimensional (3-D) images; the accuracy for stent assessment increased with ascending window levels. EBT can reliably characterize coronary artery stents and may become a useful non-invasiveive method for patency evaluation of stented coronary segments after PTCA.

Adult↗
PubMed2000

Electron beam tomography with three-dimensional reconstruction in the diagnosis of aortic diseases.

BACKGROUND: This study was performed to evaluate the protocols of electron beam tomographic angiography and three-dimensional reconstruction for assessing the diagnostic value of aortic diseases. METHODS EXPERIMENTAL DESIGN: Retrospective and comparative study. SETTINGS: University hospital. PATIENTS: Between 1996 and 1998, 189 cases who underwent electron beam tomographic angiography and diagnosed with aortic diseases were analyzed retrospectively. The results were compared with surgical and pathological findings in 68 cases. Electron beam tomographic angiography was used single-slice-scanning with ECG-triggering for screening of the thoracic aorta, continuous-volume-scanning, permitted by continuous X-ray exposure with table incremention, was performed for the abdominal aorta scanning without ECG-triggering. Three-dimensional reconstructions were performed with shaded-surface display, multiplanar reformatting and/or maximum intensity projection methods. RESULTS: Electron beam tomography angiography with ECG-triggered sections of single-slice-scanning improved the image quality of the ascending aorta without motion artifacts. Continuous-volume-scanning was suitable for screening of the abdominal aorta because of minimizing exposure time (10-14 sec) and saving contrast media (total contrast material of 45.5+/-6.6 ml was needed). One hundred eighty-nine cases were diagnosed with aortic dissection (97 cases), aortic aneurysm (26 cases), pseudoaneurysm (8 cases), Marfan's syndrome (39 cases), Takayasu's arteritis (5 cases) and congenital aortic malformations (14 cases). Electron beam tomography results were compared with the findings of surgery (as gold standard) in 68 cases, the diagnostic accuracy was 97% (2 cases with aortic aneurysm were erroneously diagnosed with pseudoaneurysm). CONCLUSIONS: Electrocardiographically triggered, contrast-enhanced electron beam tomography is feasible for the diagnosis of all kinds of aortic diseases, with excellent three-dimensional images competitive in quality with conventional selective aortic angiography or digital subtraction angiography.

Adolescent↗
PubMed2000

[The effect of melatonin on enhancing immune function and inhibiting the ability of NO over-release in morphine dependent mice].

AIM: To observe the effects and mechanism of melatonin (MT) on the immune function of morphine dependent mice. METHODS: A physical dependent mice model was established by repeated subcutaneous injection of morphine. The intensity of morphine withdrawal syndrome was evaluated according to the weight of immune organs, the proliferation reaction of stimulated splenic lymphocytes by Con A, the phagoindex of blood primed macrophages and the content of NO induced in the peritoneal macrophage (pM phi). RESULTS: MT reversed the inhibitory effect of morphine on the proliferation ability of splenic lymphocytes and enhanced the phagocytosis of macrophages of morphine dependent mice obviously and prevented the over-release of NO from pM phi. The enhancing effects of MT on the phagocytosis can be prevented by naloxon. CONCLUSION: MT can significantly enhance the immune function of morphine dependent mice and inhibit NO excessive release from pM phi.

Adjuvants, Immunologic↗
PubMed1999

A variant Klinefelter syndrome patient with an XXY/XX/XY karyotype studied by GTG-banding and fluorescence in situ hybridization.

Klinefelter syndrome is the first human sex chromosomal abnormality to be reported. The majority of Klinefelter syndrome patients have the XXY karyotype. Approximately 15% of Klinefelter patients, however, are mosaics with variable phenotypes. Among the variant Klinefelter genotypes are such karyotypes as XY/XXY and XX/XXY. The variation in phenotypes most likely depends on the number of abnormal cells and their location in body tissues. In this paper we report the case of a 42-year-old patient with Klinefelter syndrome and a rare variant mosaic XXY/XX karyotype initially identified by GTG-banding. This was confirmed by fluorescence in situ hybridization (FISH) using a dual-color X/Y probe. The patient presented with erectile dysfunction and few other physical findings. Thus, this case illustrates a rare variant of Klinefelter syndrome with a relatively mild phenotype. It also illustrates the utility of FISH as an adjunct to conventional cytogenetics in assessing the chromosome copy number in each cell line of a mosaic. In our case, FISH also detected the presence of a small population of cells with the XY karyotype not previously detected in the initial 30-cell GTG-banding analysis. Thus, through a combination of GTG-banding and FISH, the patient was determined to be an XXY/XX/XY mosaic. Given that most individuals with Klinefelter syndrome are infertile, and that these individuals may wish to reproduce with the aid of modern reproductive technology, such as testicular fine needle aspiration and intracytoplasmic sperm injection, it is important that accurate estimation of the frequency of abnormal cells be obtained for accurate risk estimation and genetic counseling, as recent studies in patients with mosaic Klinefelter syndrome revealed that germ cells with sex chromosomal abnormalities were nevertheless capable of completing meiosis.

Adult↗
PubMed1999

Angiotensin I converting enzyme gene polymorphism and insulin resistance in patients with angina pectoris.

The association between insertion/deletion polymorphism of the angiotensin I converting enzyme (ACE) gene and insulin resistance (IR) was investigated in 64 consecutive patients (F/M: 11/53) with angina pectoris without clinically manifest diabetes mellitus who underwent diagnostic coronary angiography. The observed frequency distribution of ACE genotypes did not deviate from that predicted from the Hardy-Weinberg equilibrium in this group. Patients with the ACE-ID genotype had significantly lower IR, as assessed by an oral glucose tolerance test (OGTT) and by homeostatic model assessment (HOMA), compared to those with the ACE-II genotype, as assessed by a multiple comparison analysis. Patients were divided into two groups with low and high HOMA-IR, and the I allele was seen more frequently in the high HOMA-IR group than in the low HOMA-IR group (0.62 v 0.47, respectively, by chi2 test, P < .05). Logistic regression analysis showed that the odds ratio for insulin resistance in patients with the II genotype, compared to those with the ID and DD-genotypes (assuming that the I allele has a recessive effect), was 4.0 (95% confidence interval, 1.2 to 16.5; P = .037), after adjusting for the presence of significant coronary atherosclerosis. In conclusion, the D allele was not associated with higher insulin resistance in patients with angina pectoris; that is, patients with the ID and DD genotypes were associated with a significantly lower risk of insulin resistance, compared to those with the II genotype.

Aged↗
PubMed1999

Rapid detection of glycoprotein G gene for the diagnosis and typing of herpes simplex virus infection in genital herpes.

OBJECTIVE: To develop a new, rapid, and convenient technique for the diagnosis and typing of herpes simplex virus (HSV) in genital herpes (GH). METHODS: Using samples from skin vesicle fluid and urogenital mucosal swabs of subjects with GH, conventional polymerase chain reaction (PCR) (directed to polymerase gene: PCRpG) were compared with a newly developed PCR (directed to HSV glycoprotein gene: PCRgG). Both PCR methods were compared with virus isolation culture (VI) with indirect immunofluorescent staining (IIF). RESULTS: 80 samples from 40 GH patients (25 males) were tested. Positive results were seen in 52.5% (42/80) using PCRgG compared with 40% (32/80) by VI. Most of PCRgG positive samples (95.1%) were caused by HSV-2 infection. In samples from healing lesions, HSV was detected more often by PCRgG, than by VI. The results of typing by PCRgG and IIF were highly consistent. CONCLUSION: PCRgG is more sensitive than VI and PCRgG in detecting HSV in urogenital samples from subjects with GH. PCRgG is a convenient technique for the rapid detection and typing of GH.

Female↗
PubMed1999

[Mechanism of selenium protecting against free radical damages during myocardial ischemia/reperfusion in rats].

OBJECTIVE: To investigate the mechanism of selenium (Se) protecting against free radical damages during myocardial ischemia/reperfusion (I/R) in rats. METHODS: All rats were separated into three groups: control, organic Se and inorganic Se supplemented groups. Myocardial I/R was established by operation in all three groups. Biochemical assays, atomic absorption spectrophotometry, RT-PCR and cDNA sequence scanning were performed to examine the changes in myocardial MDA level, GSH-Px activity and gene expression, GSH-Px cDNA nucleotide sequence, as well as Se and Ca2+ and Mg2+ concentrations in the heart muscle during I/R. RESULTS: The administration of Se for 7 days did not significantly change the content of Se in the plasma and blood cells. In the two Se-supplemented groups, after reperfusion for 30 minutes, myocardial Se concentration and GSH-Px activity were increased significantly, and GSH-Px expression was elevated with a normal cDNA sequence, and at the same time, MDA contents in the two Se-supplemented groups were lower than that in the control group. CONCLUSION: Se supplementation can protect against free radical damages during myocardial I/R by increasing myocardial Se content and improving both the expression and activity of GSH-Px.

Animals↗