Search PubMed⌕ Search

Biomedical subjects

L Wei

Publications and source records attributed to L Wei.

At least 127 records · Page 7Linked to original sources
PubMed1999

Differences between relapsing-remitting and chronic progressive multiple sclerosis as determined with quantitative MR imaging.

PURPOSE: To investigate the cross-sectional relationships among multiple quantitative brain magnetic resonance (MR) imaging measurements in patients with relapsing-remitting versus chronic progressive multiple sclerosis (MS). MATERIALS AND METHODS: Thirty-eight patients with MS (relapsing-remitting, 26, chronic progressive, 12) were examined. Lesion volume on T2-weighted MR images, contrast material-enhancing lesion volume, percentage of brain parenchymal volume (brain volume/[brain volume + cerebrospinal fluid volume), and magnetization transfer ratio histogram peak height for the whole brain were calculated. RESULTS: Significant negative correlation was noted between volume on T2-weighted images and magnetization transfer ratio histogram peak height for both the relapsing-remitting and chronic progressive groups (P < .001 for both). A positive correlation was demonstrated for lesion volume on T2-weighted images and enhancing lesion volume in the relapsing-remitting group (P < .01) but not in the chronic progressive group. Negative correlations were demonstrated for enhancing lesion volume and magnetization transfer ratio histogram peak height (P = .02), for Expanded Disability Status Scale score and magnetization transfer histogram peak height (P = .02), and for Expanded Disability Status Scale score and percentage of brain parenchymal volume in the relapsing-remitting group (P = .004) but not in the chronic progressive group. CONCLUSION: The cross-sectional relationships among multiple quantitative brain MR imaging measurements are different between relapsing-remitting and chronic progressive MS.

Adult↗
PubMed1999

Relapsing-remitting multiple sclerosis: longitudinal analysis of MR images--lack of correlation between changes in T2 lesion volume and clinical findings.

PURPOSE: To determine the relationship between T2 lesion volume and either disability measurements or change in T2 lesion volume over time in multiple sclerosis (MS). MATERIALS AND METHODS: Eighteen patients (age range, 26-53 years) with clinically proved relapsing-remitting MS were examined every 6 months for over 2 years. Three-millimeter-thick contiguous images of the whole brain were obtained. T2 lesion volume was calculated with a highly reproducible volumetric computer method. RESULTS: A substantial annual increase in T2 lesion volume, with a median annual increase of approximately 8%, was demonstrated. However, there was no significant correlation between absolute T2 lesion volume and either the absolute expanded disability status scale (EDSS) grade (P = .32) or the absolute ambulation index (AI) (P = .20). In addition, no significant correlation between change in T2 lesion volume and change in EDSS grade (P = .42) or AI (P = .37) was found. There was no significant correlation between T2 lesion volume and duration of disease (P = .08). CONCLUSION: There is no significant correlation between T2 lesion volume and standardized disability measurements despite a substantial increase in T2 lesion volume over time. Patients have an increase in total T2 lesion volume in the brain regardless of their clinical status or disability measurements. T2 lesion volumes as outcomes in therapeutic clinical trials on MS should be viewed as secondary outcomes rather than as surrogate markers of clinical responses.

Adult↗
PubMed1999

Tissue composition affects measures of postabsorptive human skeletal muscle metabolism: comparison across genders.

Despite clear anthropomorphic differences, gender differences in human skeletal muscle protein and carbohydrate metabolism have not been carefully examined. We compared postabsorptive forearm glucose, oxygen, and lactate balances and forearm protein kinetics between 40 male and 36 female subjects. Forearm composition was measured in a subset of 17 subjects (8 males and 9 females) using multislice magnetic resonance imaging. Oxygen uptake, net phenylalanine release, and estimated rates of forearm protein synthesis and degradation were greater in male than in female subjects when expressed as the rate per 100 mL forearm volume (P < 0.05). In males, however, muscle accounted for 58% of forearm volume, compared with 46% in females (P < 0.001). When phenylalanine balance, protein degradation and synthesis, and glucose and oxygen uptake were expressed per 100 mL forearm muscle, there were no significant differences across gender. Likewise, the extraction fractions for oxygen, glucose, phenylalanine, and labeled phenylalanine were comparable in males and females. We conclude that cross-gender comparisons of metabolic variables must accommodate differences in tissue composition. These data indicate that in the postabsorptive state, skeletal muscle metabolism of glucose, protein, and oxygen do not differ by gender in healthy young humans.

Adult↗
PubMed1999

Detection of GB virus C/hepatitis G virus RNA by reverse-transcription polymerase chain reaction.

Recently, a novel RNA virus, designated GB virus C or hepatitis G virus (GBV-C/HGV) has been identified which may possibly be associated with human hepatitis. In this study, the nucleotide sequences of the partial nonstructural 5 (NS5) gene of GBV-C/HGV derived from sera of eight Chinese patients were determined. The overall degree of nucleotide conservation and the existence of regional highly conserved sequences make this part of the genome suitable for the development of diagnostic reagents. On the basis of sequence analysis, two sets of oligonucleotide primers were designed to establish a nested polymerase chain reaction (PCR) for detection of GBV-C/HGV RNA. The efficacy of three PCR methods (first, one stage PCR, second, nested PCR with primers from the NS5 region designed according to the prototype sequence and the third, our newly developed PCR) was compared in 133 Chinese patients with liver disease. The positive rates of these three methods were 8.3%, 11.3% and 18.0% respectively. The specificity of our PCR detecting system was verified by sequencing and restriction fragment length polymorphism (RFLP). In conclusion, because of the heterogeneity and geographic distribution character of GBV-C/HGV, it is necessary to assess the sequence variation among Chinese patients infected with GBV-C/HGV. This may allow to identify GBV-C/HGV RNA with high sensitivity and specificity.

Base Sequence↗
PubMed1999

Treatment of complications due to peritoneal dialysis for chronic renal failure with traditional Chinese medicine.

In this paper, the experience in the treatment of complications due to continuous ambulatory peritoneal dialysis for chronic renal failure with traditional Chinese medicine (TCM) is reported. Modified Renshen Yangrong Tang (Ginseng Nutrition Decoction) was used for anorexia and hypoproteinemia; modified Xiangsha Liujunzi Tang (Decoction of Cyperus and Amomum with Six Noble Ingredients) for abdominal pain and distension; modified Da Chaihu Tang (Major Bupleurum Decoction) for peritonitis; modified Shenling Baizhu San (Powder of Ginseng, Poria and Atractylodes) for diarrhea due to insufficiency of the spleen with abundance of dampness; Lizhong Tang (Decoction for Regulating the Function of Middle-jiao) and modified Sishen Wan (Pills of Four Miraculous Drugs) for insufficiency of both the spleen and the kidney; Siwu Tang (Decoction of Four Ingredients) added with other drugs for cutaneous pruritus, and Guishao Sijunzi Tang (Decoction of Four Noble Drugs added with Chinese Angelica Root and white Peony Root) for renal anemia. The therapeutic principles of invigorating the liver and kidney, strengthening the bones and muscles, and promoting blood circulation to eliminate blood stasis were adopted in the treatment of renal osteopathy, and the therapeutic principles of invigorating the liver and kidney, expelling phlegm and resolving dampness, and promoting blood circulation to eliminate blood stasis in the treatment of hyperlipemia. Shen Tekang capsules (capsules for improving the renal function) was administered to patients for strengthening the viability and improving the nutrition state, and the recipe for treating renal function failure (both formulated by the authors) for improving the renal function so as to decrease the frequency and duration of dialysis.

Anorexia↗
PubMed1999

MR imaging quantitation of gray matter involvement in multiple sclerosis and its correlation with disability measures and neurocognitive testing.

BACKGROUND AND PURPOSE: Multiple sclerosis (MS) is the most common inflammatory disease of the central nervous system and manifests both physical and neurocognitive disabilities. Although predominantly a disease of the white matter, MS is also characterized by lesions in the gray matter. Previous pathologic studies have found that cortical and deep gray matter lesions comprised 5% and 4%, respectively, of total lesions. Using software for lesion detection and quantitation, our study was designed to determine MS involvement in the cortical and deep gray matter and to correlate gray matter lesion load with neurocognitive function and the Kurtzke Expanded Disability Status Scale. METHODS: Using a semiautomated segmentation algorithm that detected and delineated all possible brain MS lesions on MR images, we investigated gray matter lesion volume in 18 patients with untreated relapsing-remitting MS. Cortical and deep gray matter lesions then were correlated with the neurocognitive and physical disability measurements. RESULTS: We found that cortical gray matter lesions comprised approximately 5.7% of the total lesion volume, whereas deep gray matter lesions comprised another 4.6% in this patient cohort. No strong correlations were found between gray matter lesions and disability status or neurocognitive function. CONCLUSION: These results are similar to those found in previous pathologic studies. The cortical lesion load in cases of relapsing-remitting MS, as measured by MR imaging, represents less than 6% of the total lesion volume and does not correlate with disability measures or neurocognitive tests.

Adult↗
PubMed1999

Session management for web-based healthcare applications.

In health care systems, users may access multiple applications during one session of interaction with the system. However, users must sign on to each application individually, and it is difficult to maintain a common context among these applications. We are developing a session management system for web-based applications using LDAP directory service, which will allow single sign-on to multiple web-based applications, and maintain a common context among those applications for the user. This paper discusses the motivations for building this system, the system architecture, and the challenges of our approach, such as the session objects management for the user, and session security.

Computer Security↗
PubMed1999

[A case-control study on the risk factors in naevus fusco-caeruleus zygomaticus].

OBJECTIVE: To determine the risk factors of naevus fusco-caeruleus zygomaticus, a case-control study was conducted in 100 cases. METHODS: The selection of major risk factors was through logistic regression and chi 2-test. RESULTS: It was suggested that the high exposed rate in the family history of objectives was related to "genetic susceptibility". Histories of using cosmetics and exposure to ultraviolet ray were identified as environmental risk factors. However, there was no single factor that could completely explain the etiology of naevus fusco-caeruleus zygomaticus. CONCLUSION: We believe that coordinating effects of both susceptibility in genetics and environmental risk factors may play important roles in the pathogenesis of naevus fusco-caeruleus zygomaticus. Thus combined research on the location of gene mutation with environmental factors is important in the discovery of the etiology of naevus fusco-caeruleus zygomaticus.

Adolescent↗
PubMed1999

[The expression of nm23-H1 genes with clinical prognosis in endometrial carcinoma].

OBJECTIVE: To study the expression of nm23-H1 gene in endometrial carcinoma and its relationships between the clinicopathological parameter and prognosis of endometrial carcinoma. METHODS: The endometrial specimens of 60 cases with endometrial carcinoma were studied retrospectively by immunohistochemical stainings. RESULTS: The positive expression rate of nm23-H1 gene in endometrial carcinoma was 55.0% (33/60). The positive rate of nm23-H1 in early endometrial carcinoma was significantly higher than that in advanced cases (65.9% and 25.0%, respectively, P < 0.05). Positive rates in the well and moderately differentiated endometrial carcinoma were also higher than those of poorly differentiated (66.7%, 63.6%, 29.4%, P < 0.05). 20.0% of the cases with and 64.9% of the cases without lymph node metastasis showed positive for nm23-H1 (P < 0.05). The expression of nm23-H1 was not correlated with histological type, myometrial invasion, estrogen receptor and progesterone receptor. The survival rate of patients with nm23-H1 expression was significantly higher than that of patients without nm23-H1 expression. The 5-year survival rate was 90.5% and 55.3% respectively (P < 0.05). CONCLUSION: nm23-H1 gene may play a role in the inhibitory effect on the development and the lymph node metastasis of endometrial carcinoma, and may be related to be prognosis of endometrial carcinoma.

Adenocarcinoma↗
PubMed1999

Morphometric and histological study of coronary plaques in stable angina and acute myocardial infarctions.

OBJECTIVE: To compare the morphological difference of coronary plaques in acute myocardial infarction and stable angina to clarify the occurrence basis of these two different myocardial events. METHODS: Sixty-eight acute myocardial infarction cases and 34 stable angina postmortem cases were studied. The coronary arteries were dissected en block, fixed, decalcified, sectioned at a 3 mm interval and processed routinely for histologic examination. A computor-aided planimeter was used to measure plaque and lipid core area. RESULTS: Among the total 4089 coronary blocks in acute myocardial infarction, 2087 (51.0%) had a lipid core over 40% of the plaque area; while among the total 2030 blocks in stable angina, only 209 (10.3%) had a lipid core over 40% of the plaque area (P < 0.05). Sixty-one of the 68 (89.7%) acute myocardial infarction cases had thrombi among which 56 occurred on ruptured plaques; while no thrombus was found in stable angina. In addition, atheroemboli were found in most of the thrombus-negative acute myocardial infarction cases (6/7) but none in SA cases. CONCLUSIONS: Acute myocardial infarction and stable angina had different morphologic basis of the coronary plaques. The former had more plaques with a large lipid core than the latter. Acute myocardial infarction was caused mainly by plaque rupture and associated thrombus. But atheroembolus could be another very important cause of acute myocardial infarction.

Aged↗
PubMed1999

[Cervical lymph node metastasis and blood metastasis of thyroid cancer].

OBJECTIVE: To evaluate the relevant factors for lymph cervical node metastases and blood metastases of thyroid cancer and to raise the level of diagnosis and treatment. METHODS: 225 cases of thyroid cancer were treated from Jan. 1984 to Dec. 1992. Their clinical characteristics, treatment, and pathologic features were described. RESULTS: The metastasis of thyroid cancer was related to its pathologic and invasive features. Papillary and squamous cell carcinomas were characterized by local lymph metastasis. Their metastasis rate was 44.7%, and 3/3 respectively. Follicular carcinoma showed good differentiation but vessel metastasis with a metastatic rate of 18.2%. The metastasis rate was high and the prognosis poor, in undifferentiated cancer. CONCLUSIONS: Better treatment results may be achieved if proper management of thyroid cancer is based on its pathologic type and extent of local infiltration.

Adenocarcinoma, Follicular↗
PubMed1999

[Relationship between retinal and glomerular microvascular lesions in experimental diabetes in rat].

OBJECTIVE: To evaluate the relationship between diabetic retinopathy (DR) and diabetic nephropathy (DN). METHODS: The thickness of retinal capillary basement membrane (RBM) and glomerular basement membrane (GBM) and their anionic sites were quantitatively analyzed by electron microscopy and immunohistochemical methods. RESULTS: RBM and GBM became gradually thickened with the development of diabetes. The thickened basement membrane was accompanied with decrease of anionic sites in number. CONCLUSION: DR and DN share partly the pathological process, and there are also some incoordinate phenomena in the microvascular lesion.

Animals↗
PubMed1999

[Morphometric study of inflammatory cells and smooth muscle cells in coronary plaques and their relation with plaque stability].

OBJECTIVE: To compare the content of inflammatory cells and smooth muscle cells in stable and unstable coronary plaques in order to clarify the role of these cells in the vulnerability of plaques. METHODS: Hearts from 12 postmortem acute myocardial infarction cases were studied. The epicardial coronary arteries were dissected en bloc, fixed, decalcified, cut at 4 mm intervals and routinely processed for HE sections. 163 stable plaques (with no or only little lipid core) and 163 unstable plaques (with lipid core size > 40% of plaque area) were studied immunohistochemically using monoclonal antibodies specific for macrophages (CD68), T lymphocytes (UCHL-1) and smooth muscle cells (actin). Computor aided planimetry was used to measure the positive area of different cells. RESULTS: The content of macrophage and T lymphocytes in unstable plaques were significantly higher than that in stable plaques (P < 0.05). CONCLUSIONS: Stable plaques and unstable plaques not only had different lipid core size but also had different inflammatory cell and smooth muscle cell content. The larger the lipid core and the more macrophages and T lymphocytes in the fibrous cap, the more unstable the plaque. The lipid core and inflammatory cells (including macrophages and T lymphocytes) are the two major determinants of the vulnerability of coronary plaques.

Actins↗
PubMed1999

[Determination of alkaloids in Coptis-Cinnamomum compatibility by capillary electrophoresis].

OBJECTIVE: To establish a HPCE method to determine the contents of alkalods in Rhizoma Coptidis. METHOD: HPCE. RESULT: The constituents thus determined have good linearity and separation. The average recovery of coptisine, berberine, palmatine and jatrorrhizine was 98.28%, 98.38%, 97.78% and 98.89% respectively and RSD 0.86%, 1.12%, 1.06% and 1.11% respectively. CONCLUSION: The method is convenient, rapid, accurate and practicable. The compatibility reduces the contents of alkaloids in Rhizoma Coptidis in different degrees.

Alkaloids↗
PubMed1999

[Studies on precipitate of Huanglian-Huangqin couples in decoction].

OBJECTIVE: Chemical composition of precipitate was researched when Huanglian-Huangqin was decocted. METHOD: Ployamide column chromatography, TLC and TOF-MS were used. RESULT: The precipitate contains berberine, palmatine, jalrorrhizing, epiberberine, copticine, baicaling and wogonoside. CONCLUSION: The precipitate is effective composition in Chinese medical decoction. The research provides new data on medical effects of Huanglian-Huangqin couples.

Alkaloids↗