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Biomedical subjects

L Wu

Publications and source records attributed to L Wu.

At least 469 records · Page 26Linked to original sources
PubMed1997

[Experimental studies about effect of dexamethasone on diaphragm of normal rats].

The influence of dexamethasone on diaphragm function, its oxidative capacity, fiber cross-sectional areas, the content of glycogen and ultrastructural changes were determined in Wistar rats by receiving dexamethasone (2 mg/kg) muscle injection for two weeks. We noted dexamethasone treatment leads to significant atrophy of the mass of diaphragm, reduction of fiber cross-sectional areas (CSA) of type II a, II b fibers. Under high frequency (100 Hz) stimulation, the tention of the diaphragm muscle strips was decreased and diaphragm fatigue resistance (1/2 RT) was significantly improved. Histochemically, ATPase activity in type I and type II b fibers of the diaphragm was significantly reduced and a significant reduction of succinate dehydrogenase activity in the diaphragm was also observed, but increased glycogen was seen in the diaphragm. Ultrastructural changes including mitochondrial hyperplasia, swelling, myofibillae focus destructure were evident. It is concluded that steroid-induced myopathy may also involve the diaphragm.

Adenosine Triphosphatases↗
PubMed1997

[Immunohistochemical study on vitrectomy specimens of proliferative retinal diseases].

OBJECTIVE: To evaluate the characteristics of cellular proliferation in different retinal diseases. METHODS: Three specific antibodies [to cytokeratin (CK), glial fibrillary acidic protein (GFAP) and actin, respectively] were used. Vitrectomy specimens from 28 cases with different proliferative retinal diseases were studied immunohistochemically. RESULTS: In the vitreous with proliferative vetreoretinopathy (PVR), most of the proliferative cells were derived from glial and retinal pigment epithelial (RPE) cells. In the vitreous of proliferative diabetic retinopathy (PDR), RPE cells might enhance the contraction of proliferative membranes. Increase in actin in firovascular membranes with PDR may play a positive role on the pericytes dropping out from microvessels. CONCLUSION: The cell proliferation in the vitreous associated with the increase of levels of growth factors in pathological vitreous, possibly, is one of the mechanisms for the deterioration of proliferative retinal diseases.

Actins↗
PubMed1997

[The significance of preoperative visual electrophysiology for vitrectomy].

OBJECTIVE: To investigate the prognostic value of preoperative visual electrophysiology in patients with vitreoretinopathy (VRP) who underwent vitrectomy. METHODS: Electroretinogram (ERG) and visual evoked potential (VEP) were performed prior to vitrectomy in 82 patients with vitreous hemorrhage or opacity due to ocular trauma, retinal detachment or retinal vascular diseases (Eales' disease, diabetic retinopathy, etc.). A comparative analysis was made of the effectiveness and visual acuities 2 weeks postoperatively. RESULTS: Among the 82 eyes, the preoperative ERG was normal in 6 eyes, slightly or moderately reduced in 37 eyes and severely reduced or had no response in 39 eyes. Of these 39 eyes, no improvement or reduction in postoperative visual acuity was seen in 23 and 6 eyes respectively, a sharp contrast to the postoperative results of the 6 normal ERG eyes. The preoperative ERGs differed due to different causes. A further analysis regarding the VEP of the patients who had poor postoperative results was made. CONCLUSIONS: The data showed that the preoperative visual electrophysiology was significantly correlated with the effectiveness of the operation. It is helpful in prognostic assessment of the postoperative outcome and visual acuity changes in VRP patients treated mainly by vitrectomy.

Electroretinography↗
PubMed1997

[Processing technology of rhizoma Arisaematis (Pinellia pedatisecta Schott)].

Using the qualitative standard of Rhizoma Arisaematis stipulated in Pharmacopoeia and combining with the toxic reaction in experimental mice, the optimum amount of KAl(SO4)2.12H2O for eliminating the toxic reaction of Rhizoma Arisaematis was selected. Based on the comparison of experiments, two new technologies for processing Rhizoma Arisaematis have been established. Pilot production shows that these technologies are feasible for mass production.

Animals↗
PubMed1997

[Acupoints specificity in promoting the plasticity of cat spinal lamina II with acupuncture-quantitative EM study].

Our previous studies have shown acupoints stimulation might promote the plasticity of spinal cord. In order to explore the acupoints specificity of the effects we used ten cats with unilateral dorsal partial rhizotomy (L1-S2, except L6). The rhizotomy sides of five cats received acupuncture stimulation (acupoints stimulation group) at Zusanli (St36), Xuanzhong (GB 39), Futu (St32) and Sanyinjiao (Sp 6) in the innervated areas of L6 spinal nerve for two courses, 10 days per coure. The rest cats were subjected to needling at the areas adjacent to the acupoints (nonacupoints stimulation group). Quantitative EM method was applied to detect (the population of synaptic terminals in lamina II 30 days postoperation. According to the number of synaptic contacts between synaptic terminal and postsynaptic element, synaptic terminals were divided into two types: the simple terminal (ST) coming from spinal and descending tract, and the complex terminal (CT) from dorsal root. The average numbers of the two types' synaptic terminals per photo were compared directly because the acupoints and nonacupoints groups' transverse areas of lamina II showed no significant difference. The results showed: (1) There was no significant difference for ST number between two groups. Associated with our previous study that acupoints stimulation did not influence ST number, the present result indicated that nonacupoints stimulation had no effect on ST number, (2) The complex terminal numbers were statistically different (P < 0.05). The percentage of CT in the nonacupoints group was only 53% of that in the acupoints group. This result was similar to two other nonacupuncture groups in our laboratory (the percentages were 59% and 62% respectively). It indicates that the effect of nonacupoints stimulation is similar to that of nonneeding, i.e. nonacupoints stimulation does not promote the plasticity of spinal lamina II or there might be acupoints specificity in promoting the plasticity of spinal laminal II.

Acupuncture Points↗
PubMed1997

[Optimization of quenching system for determination of emodin and chrysophanol by chemiluminescence method].

Determination of the valid components in traditional Chinese medicine is one of the key steps for its identification, and the development of accurate and simple methods is necessary for the present analysis work of medicines. In this paper, the experimental conditions were optimized and procedures chosen for determination of emodin and chrysophanol by lunminol-H2O2-Cr3+ chemiluminescence quenching system. The dynamic range for determination of emodin was 10(-4)-10(-8) g/ml (r = 0.9965), with a detection limit of 1.57 x 10(-9) g/ml. The RSD and recovery for determination of 10(-7) g/ml of emodin (n = 6) were 0.4% and 92.8% +/- 0.5%, respectively. Satisfactory results were also obtained when the method was used to determine chrysophanol. This method was used, after separation by thin layer chromatography, to determine emodin and chrysophanol in several traditional Chinese patent medicines, and the results were in good agreement with those obtained by the standard colorimetric method.

Anthraquinones↗
PubMed1997

[Effect of processing on toxcicity and analgesia of radix Aconiti coreani].

The experimental results showed that the Radix Aconiti Coreani and its processed products did not have remarkable toxic effect in p.o. But there was significant toxicity before processing and weakened toxicity after processing in i.p. In the skin test, the Radix Aconiti Coreani and its processed products showed no stimulating effect. The analgesic experiment showed that the Radix Aconiti Coreani and its steamed products could inhibit the pain. The products processed with bean curd and ginger-KAl(SO4)2.12H2O also could alleviate the pain induced by acetic acid, but no remarkable effect was observed in mice on the pain induced by hot plate.

Analgesics↗
PubMed1997

[Optimization of technical parameters for processing radix Aconiti coreani].

Based on the determination of guanfu A, hypaconitine, and total alkaloids, along with the experiment of acute toxicity of sliced Radix Aconiti Coreani and in compliance with the quality standard stipulated in pharmacopeia-surface features cross section colour and odor of sliced Radix Aconiti Co-reani the technology of processing Radix Aconiti Coreani has been optimized to be steaming the drug for four hours.

Aconitine↗
PubMed1997

[Preliminary study of mitochondrial DNA deletions in age-related macular degeneration].

PURPOSES: To investigate mitochondrial DNA mutation associated with oxidative phosphorylation defect due to aging and to inspect it whether to play a role in the pathogenesis of age-related macular degeneration(ARMD). METHODS: Using polymerase chain reaction (PCR) analysis, the mitochondrial DNA deletions were detected on blood samples in 20 patients with age-related macular degeneration (ARMD) and in 10 controls. RESULTS: The abnormal mtDNA fragments in blood cells were amplified on 6 cases of wet ARMD that indicated there might be three types of mtDNA deletions between positions 7901 and 13,650. The sizes of mtDNA deletions were 3.67 kb, 5.0 kb and 5.2 kb respectively. No abnormal mtDNA fragments were amplified on 10 cases in control. CONCLUSIONS: It suggests that there were multiple mitochondrial DNA deletions on the blood cells of ARMD, including an aging-associated 5.0 kb deletion and it requires further studies on relationship between the mitochondrial DNA mutation and the etiology of ARMD.

Age Factors↗
PubMed1997

[Objective assessment of visual acuity with visual evoked potential].

PURPOSE: To study the technique for objectively assessment of visual acuity with Pattern Visual Evoked Potential (PVEP) and Discrete Fourier Transform (DFT). METHOD: Thirty-three normal eyes were tested in this study. Reversal square-wave gratings of eight different sizes (30, 20, 18, 12, 10, 6, 4, 2 min. of arc) were used as stimuli. The reversal rate of the stimuli was 10 times/sec. The harmonic amplitudes of VEP at 10 Hz were calculated with Discrete Fourier Transform. A relation curve between the harmonic amplitude and the size of grating was plotted from the data of each tested eye. Regression line was fitted to the data points in the approximately linear section of the curve which is near the threshold of zero amplitude. The threshold of the grating size was obtained by extrapolating of the regression line to zero amplitude, and the visual acuity was assessed with the threshold. RESULT: In seventy percent of tested eyes, the visual acuities assessed with VEPs were consistent with those measured with the International Standard Test Chart. CONCLUSION: The VEP technique for visual acuity assessment is reliable.

Adolescent↗
PubMed1997

[Indocyanine green choroidal angiography in macular hemorrhage of uncertain origin].

PURPOSE: To search for the underlying pathology of macular hemorrhage of uncertain origin with Fundus Fluorescein Angiography (FFA). METHODS: 18 Patients (20 eyes) were tested and analyzed using Indocyanine Green Choroidal Angiography (ICGCA). RESULTS: ICGCA clearly demonstrated the underlying pathology of macular hemorrhage as the choroidal neovascularization secondary to age-related macular degeneration (14 eyes), abnormality of retinal vascular (3 eyes) and accidental macular hemorrhage (3 eyes). CONCLUSIONS: The results showed that ICGCA is very usefull for detecting the underlying pathology of macular hemorrhage of uncertain origin.

Adolescent↗
PubMed1997

[The preparation of poly (DL-lactide) hollow fiber and the release of drug in vitro].

The biodegradable hollow fibers of DL-PLA were prepared by a dry-wet phase inversion spinning process. By using four different spinning systems, DL-PLA hollow fibers with varying asymmetric membrane structure were obtained. The structure of hollow fiber wall was examined by SEM. In vitro release of norethisterone from the DL-PLA hollow fibers was also investigated. The hollow fibers were filled with a 50 wt% NET in castor oil. The DL-PLA hollow fibers NET release was found to be dependent on the membrane structure of the hollow fiber wall. Possible release mechanisms were discussed.

Delayed-Action Preparations↗
PubMed1997

[The objective evaluation of the interaction between color vision and motion perception].

PURPOSE: To measure equiluminance values of green/red grating luminosity ratios with different moving velocity in normal subjects and to explore the interaction between color vision and motion perception. METHODS: Optokinetic nystagmus (OKN) of eye movement elicited by moving color grating stimulus could be recorded with electrooculograph (EOG). The equiluminance points were determined when OKN changed in direction in various moving velocities. Sixteen cases (32 eyes) normal subjects were tested, 6 cases male and 10 cases female, Age ranged from 20 to 51 years old. RESULTS: The mean equiluminance points were 0.525, 0.425, 0.397, 0.391, 0.367 under 595, 400, 301, 239 and 200 mm/s groups of grating moving velocity respectively. There were statistically significant differences of mean equiluminance points among 595 mm/s group and other groups (P < 0.01), there were no statistically significant differences of mean equiluminance points among other 4 groups (P > 0.05). CONCLUSION: There are some influences to color vision under the high moving condition.

Adult↗
PubMed1997

[The clinical analysis of eosinophil infiltration in human squamous cell carcinoma of buccal mucosa].

Tumor-associated tissue eosinophils (TATE) is a host's defensive reaction to tumor. In this study, authors examined the eosinophil of 40 squamous cell carcinomas of buccal mucosa. Infiltration of the primary tumor by eosinophil was found to have marked prognostic significance. High-grade TATE was associated with the absence of head and neck lymphonode's metastasis (P < 0.05). There was a statistical significance (P < 0.05) that high-grade TATE was a favorable prognostic indicator for squamous cell carcinoma of the buccal mucosa. Authors concluded that quantitative assessment of eosinophils was one of the most important aspects of the microscopic evaluation of this human carcinoma.

Adult↗
PubMed1997

[Pharmacological study of the rhizome powder of Pinellia pedatisecta processed by different procedures].

The potentiation of hypnotic activity of a barbituate and acute tocicity by the rhizome powder of Pinellia pedatisecta Schott processed by pigbile with two different traditional medicinal procedures (fermentation mixing and heating alternatively) were studied in mice. The results showed that aquatic extracts of two processed drugs could potentiate the action of hypnotics; and ethanol extracts of the drug processed with mixing and heating alterntively could significantly enhance this action, compared with that of the drug pricessed with fermentation; while no acute toxicity was measured by the two processed drugs.

Animals↗
PubMed1997

[Differentiation of mumps virus strains by polymerase chain reaction and silver stained single-strand conformation polymorphism analysis].

The cDNA fragments amplified through nested RT-PCR from the small hydrophobic (SH) protein gene and its flanking region of the five wild mumps viruses and Enders strain were subjected to single-strand conformation polymorphism (SSCP) analysis by using silver staining. These five wild isolates could be divided into three SSCP patterns and they were differentiated from the Enders strain. Two wild strains which have 3.4% heterology of the nucleotide acid sequence could be distinguished by the method. The results were well correlated with sequence analysis of the SH gene segments, indicating high applicability of the silver staining SSCP analysis for differentiation of mumps virus strains. Furthermore, the method, which is not only quick, sensitive, safe and reliable, but also reproducible and inexpensive, can be used in the molecular epidemiology study of mumps viruses.

Base Sequence↗
PubMed1997

[Discovery of a novel reassortant H1N2 influenza virus].

Three strains of influenza A virus were isolated from patients suffering from influenza like disease in Railway Hygiene and Anti-epidemic Station of Taiyuan in January 1996. The identification results by serological method indicated that the isolates were different from H1N2 subtype of influenza A virus isolated from men in 1989 and 1992 and that their HA antigenicity was similar to that of A/RP/8/34 (H1N1) virus, but distinguishable from that of influenza A (H1N1) virus circulating in mans recently. The comparison of migration patterns of the RNA among the isolates, the A/PR//34 (H1N1) and the A/Wuhan/359/95 (H3N2) viruses revealed that the migration patterns of RNA 1-4 segments of the isolates were similar to those of A/PR/8/34 (H1N1) virus, but those of RNA 5-6 segments were indistinguishable from those of A/Wuhan/359/95 (H3N2) strain. However, the migration patterns of RNA 7-8 segments of the isolates were not only different from those of A/PR/8/34 (H1N1) virus, but also distingrasgable from those of A/Wuhan/359/95 (H3N2) strain. Therefore, it could be considered that the isolates were a novel reassortant H1N2 influenza A virus.

Adolescent↗