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Biomedical subjects

W L Xu

Publications and source records attributed to W L Xu.

At least 19 recordsLinked to original sources
PubMed2004

Diabetes mellitus and risk of dementia in the Kungsholmen project: a 6-year follow-up study.

BACKGROUND: Research on diabetes mellitus as a risk factor for dementia and its main subtypes has produced conflicting results. The authors investigated the relationship between diabetes mellitus and risk of dementia, Alzheimer disease (AD), and vascular dementia (VaD). METHODS: A dementia-free cohort of 1,301 community dwellers aged 75 years and older in Stockholm, Sweden, was longitudinally examined twice over 6 years to detect dementia cases (Diagnostic and Statistical Manual of Mental Disorders-III-R diagnostic criteria). Cox proportional hazards models were used to analyze the data with adjustment for several potential confounders. RESULTS: During the 5,584 person-years of follow-up, 350 subjects developed dementia, including 260 AD and 49 VaD cases. Diabetes mellitus was associated with hazard ratios (HR) of 1.5 (95% CI 1.0 to 2.1, p = 0.04) for dementia, 2.6 (95% CI 1.2 to 6.1) for VaD, and 1.3 (95% CI 0.9 to 2.1) for AD. Patients who were treated with oral antidiabetic medications had HRs of 1.7 (95% CI 1.0 to 2.8, p = 0.04) for dementia and 3.6 (95% CI 1.3 to 9.5) for VaD. There were significant interactions of diabetes with severe systolic hypertension (> or =180 mm Hg) on dementia and its main subtypes, and of diabetes with heart disease on VaD. CONCLUSIONS: Diabetes mellitus increases the risk of dementia, and VaD in particular, in very old people. The risk for dementia and VaD is especially high when diabetes mellitus occurs together with severe systolic hypertension or heart disease.

Aged↗
PubMed2001

Prevention of debris flow disasters on Chengdu-Kunming Railway.

Chengdu-Kunming Railway is an important transport line on southwestern China. However, this railway's safety is often threatened by debris flows. How to effectively forecast and alarm the debris flow disasters and reduce the losses is the aim to study the prevention system in this paper. The factors to cause or influence debris flow are divided into four parts--the basin environmental factors, the basin meteoric factors, the prevention work's elements and the flood-relief work's elements, and the prevention system is made up of three models--a judgment model to assess the debris flow gully's seriousness, a forecast model to predict the debris flow's occurrence and an alarm model to evaluate the debris flow's disaster. Afterwards, a concise structure chart is worked out and verified by the field data from Chengdu-Kunming Railway. This prevention system will provide beneficial reference for the debris flow's monitoring network to be executed on Chengdu-Kunming Railway.

China↗
PubMed2000

[Effect of dissolved oxygen on mutanolysin fermentation].

Effects of several parameters relating to dissolved oxygen(DO) on mutanolysin fermentation were studied. The experiment using shake flasks shows that the medium volume and shaker agitation speed affect the production of mutanolysin. At the same time, the agitation rate together with aeation rate has effects on DO in fermentor. Mutanolysin fermentation was affected by DO greatly. Oxygen is a key restricted factor in mutanolysin fermentation. It affects the metablism and physiological action of Streptomyces globisporus S186. Whatever the DO is excessive high or low, it won't benefit the mutanolysin production. If DO is super, S. globisporus S186 will grow luxuriantly but do not produce mutanolysin, while if DO is lower, the S. globisporus S186 won't grow well even not to produce mutanolysin. During the course of fermentation, the DO changed regularly. It is similar to many antibiotic fermentation and some amino acid fermentation. As S. globisporus S186 grow in exponential phase, DO begin to decrease rapidly from 6 h and get to the lowest point at 40 h or so. Subsequently mutanolysin starts to be produced. DO rises again from 90 h. The key technoloyg of oxygen control in the fermentation is to keep the DO at a suboptimum level. In order to get a high mutanolysin yield, during the culture in fermentor the agitation rate and aeration rate should be kept at 200 r/min and 1:0.8(V:V) respectively.

Endopeptidases↗
PubMed1997

Oocyte donation program: initial experiences at Southeastern Fertility Institute.

From March 1994 to February 1996, 28 infertile couples participated in the oocyte donation program in 33 treatment cycles at the Southeastern Fertility Institute. Of the 31 cycles with embryo transfer, 15 cycles (48.4 percent) resulted in a clinical pregnancy with fetal heart beat by ultrasound. The spontaneous first trimester abortion rate was 3/15 (20 percent), multiple pregnancy rate 3/15 (20 percent), live birth rate 11/15 (73.3 percent) and delivery rate 12/15 (80 percent). It is recommended that oocyte donation procedure is a highly successful treatment option for women with ovarian failure or repeated unsuccessful trials of assisted reproductive technologies.

Adult↗
PubMed1994

Percutaneous balloon mitral valvuloplasty. An observation of 50 patients.

Percutaneous balloon mitral valvuloplasty (PBMV) was successfully performed in 50 selected patients with mitral stenosis by using Inoue pillow-shaped balloon and Inoue technique. The average diameter of balloon used was 26.9 +/- 0.9 mm. 90% (45/50) of cases had either double or single mitral commissura split. Of the rest 5 cases, 1 had a mitral score 13 and 4 had a history of mitral valve commissurotomy. Totally they had a mean mitral valve area increase from 1.13 +/- 0.32 to 2.21 +/- 0.43 cm2, left atrial pressure decrease from 31.8 +/- 9.3 to 14.7 +/- 5.6 mmHg, left atrial diameter reduction from 44.9 +/- 7.7 to 37.4 +/- 4.9 mm, and transmitral gradient decrease from 21.7 +/- 9.8 to 4.0 +/- 5.2 mmHg. Most patients had a obvious cardiac function improvement, especially in patients with mitral score of 8 or less. 30% patients (15/50) had a mild mitral regurgitation, but relieved 3-6 months after procedure. During one year of follow up, the majority of patients (16/20) were found in a good cardiac function, mitral area and the left atrial diameter, except in 4 patients with a high mitral score of more than 10. It is suggested that for patient with lower mitral morphological score and good general health, a larger diameter balloon might be suitable for effectively improving patient's symptom, but for patients with a previous surgical mitral commissurotomy, PBMV should not be selected.

Adult↗
PubMed1994

[A study on risk factors of cerebral hemorrhage in women].

To investigate the risk factors of cerebral hemorrhage in women, we conducted a 1:1 pair matched case-control study on 98 women with cerebral hemorrhage diagnosed by CT scan of the head and the same number of controls. Single factor analysis revealed that a high body mass index (BMI) increased the risk of cerebral hemorrhage (p < 0.05). Multiple conditional logistic regression analysis showed that hypertension, snoring and the use of OCs were independent risk factors of cerebral hemorrhage in women, and the odds ratios (ORs) were 8.36 (95% CI: 3.22-21.73), 3.84 (95% CI: 1.47-10.04) and 7.96 (95% CI: 1.27-49.83), respectively. No correlations between cerebral hemorrhage in women and their occupation educational level or history of menstruation and child bearing were found.

Aged↗
PubMed1992

[Reoperation for recurrent gliomas].

Twenty-three cases of recurrent gliomas were reoperated upon. The indications and some factors influencing the length of survival time after reoperation were studied. It was found that reoperation is important in the management of recurrent gliomas, but strict indications must be followed with special attention to prevent CSF leakage, breaking and infection of the incision. Reoperation is not only to prolong life time but also to improve living quality. After reoperation, a comprehensive treatment is needed.

Adult↗
PubMed1991

[Development of gentamicin sulfate sustained release tablet remaining-floating in stomach].

Gentamicin sulfate sustained-release tablet remaining-floating in stomach (G-HBS) was developed based on the hydrodynamically balanced system. The dissolution rate of G-HBS was determined by rotary basket method (100 r/min, 37 +/- 0.5 degrees C, 0.1 mol/L HCl). The release characteristics of G-HBS showed basically first order kinetics with the dissolution rate constant (Kr) of 0.3992 h-1. The mean dissolution time (MDT) of G-HBS was 2.53 h-1. The density of G-HBS was found to have no significant influence on dissolution of G-BHS. The gamma-scintiphoto technique was used to examine the gastric retention time of G-HBS and GCT (gentamicin sulfate conventional tablet). It was shown that the gastric retention time of all subjects taking G-HBS under fed and fasted conditions were all over 4 h, in contrast with GCT, only 1-2 h. The stability of G-HBS was investigated and a tentative two-year expiration date was established. Spectrophotometry for the determination of gentamicin was established. The effect of G-HBS on Campylobacter pyloridis-associated chronic gastritis was examined through clinical trials.

Adult↗
PubMed1989

States of determination of single cells transplanted between 512-cell Xenopus embryos.

Single cells from 512-cell Xenopus embryos, totally labeled with intracellular horseradish peroxidase, were transplanted orthotopically (from either dorsal or lateral marginal zone) or heterotopically (between these two marginal zones) to unlabeled host embryos at the 512-cell stage. At tailbud stage 23 the locations, numbers, and histotypes of labeled cells were recorded. The transplanted cell had divided many times, giving rise to labeled progeny that expressed a wide range of cell types and were located in several different organs. Locations and cell types of progeny derived from orthotopic grafts to the dorsal marginal zone were different from those derived from grafts to the lateral marginal zone. Single cells grafted heterotopically to either dorsal or lateral positions expressed fates that were appropriate to their final grafted positions, and not to their original positions. We conclude that individual cells of the marginal zone at the 512-cell stage have multiple presumptive fates and have not been committed to any single fate.

Animals↗
PubMed1989

[Surgical treatment of thalamic tumors].

15 cases of thalamic tumor are presented. Among them, 6 cases were diagnosed by ventriculography and angiography before 1980. Since 1981, 9 cases were diagnosed by CT scan. Operation was refused in 3 cases. Lateral ventriculo and superior sagittal sinus shunt was performed in one case. Open biopsy by craniotomy followed by ventriculo-interhemispheric fissure shunt was done in 2 cases. Partial resection of tumor in 8 cases. Total resection was achieved in one case. The choice of treatment of thalamic tumors is discussed. The author prefers direct operation for that may got some tumor tissues and could made the actual diagnosis pathologically. The quantity of tumor removed is decided according to the situation. Raised intracranial pressure must be controlled by shunt, and preventing its infection is very important.

Adolescent↗
PubMed1983

Structure of the archaebacterial transposable element ISH50.

We have sequenced in its entirety a new transposable element from the archaebacterium Halobacterium halobium. This 996 bp element shows some features not unlike those of insertion sequences from eubacteria, although it clearly differs from them in sequences which may be involved in transcription and or translation initiation.

Base Sequence↗