Biomedical subjects
Publications and source records attributed to W Xu.
We studied the purification of cellulase from Blue mussel homogenate with STREAMLINE chelating adsorbent in an expended bed chromatography. The cellulase was purified 19.5 times without removing the cell debris and a recovery of 82% was obtained.
OBJECTIVE: To investigate the change of epidermal growth factor (EGF) concentration in serum and villi of early pregnant women and its possible effects by mifepristone. METHODS: Twenty normal women as control and sixty-six early pregnant women were enrolled for study. Serum EGF, estradiol (E2) and progesterone (P) concentrations were measured with radioimmunoassay. EGF concentration in villi by surgical aspiration and mifepristone induced abortion were compared. RESULTS: Serum EGF concentration in early pregnant women was significantly higher than that in non-pregnant women (P < 0.01). The serum EGF, E2 and P concentrations increased as pregnancy advanced (P < 0.05). The growth rate of gestational sac declined and serum EGF and P concentrations decreased slightly after administration of mifepristone. Villi EGF content in mifepristone group was significantly lower than that in surgical group (P < 0.05). CONCLUSION: EGF may be involved in regulating embryo development. Mifepristone may interfere embryonic development via inhibiting EGF level.
The Kunming mice were selected as subjects. Animals were allowed to move and drink freely. The Naloxone(0.02 mg/g) was injected by abdominal cavity. The ability to body temperature stable by mice under the environment with high temperature (41 degrees C, 43 degrees C) was observed. The results showed that after obstructing opium receptor by Naloxone, the ability mentioned above was reduced obviously.
With the development of new imaging modality, MRI and CT scanning has become the most useful adjunct to physical examination for the preoperative evaluation of cervical lymph node metastases of squamous cell carcinoma of the head and neck(SCHN). The study was designed to compare CT scans of metastatic lymph node with corresponding histologic sections on 26 dissections in total and discussed the criteria for assessment of nodal metastases with histologic sections. With pathologic findings as the standard, sensitivity, specificity and accuracy of CT in the detection of nodal disease is 93.8%, 90.0% and 92.3%. Regarding extracapsular nodal spread, CT scanning results in the accuracy of 72.7%. The accuracy of CT detecting central nodal necrosis was 88.9%. This study indicated that CT is accurate in detecting cervical lymph node metastases from head and neck squamous cell carcinoma.
OBJECTIVES: To identify the effects of tuberculin purified protein derivative (PPD) sensitization on attenuating pulmonary T helper 2 (Th2) reaction and eosinophil infiltration in ovalbumin sensitized mice, and to search for the possibility of its clinical use in the management of asthma in a new way. METHODS: Sixty C57BL/6 mice were sensitized with PPD and then with ovalbumin and aluminum hydroxide, and randomized into 4 groups: ovalbumin (OVA), pre-PPD, post-PPD and control groups. Aerosol PPD were administered 3 h before or after ovalbumin challenge in the pre-PPD and post-PPD groups respectively, and control group received aerosol PPD only. IL-4, IL-5 expression was detected by immunocytochemistry in situ hybridization. Lung slides were stained with eosin and hemotoxylin, and pathological changes were observed. RESULTS: Ovalbumin aerosol inhalation caused a mixed inflammatory infiltration dominated by CD4+ T lymphocytes and eosinophils in the lung of sensitized mice. 87.5%-89.7% and 89.0%-89.2% of the CD4+ T lymphocytes were IL-4 mRNA+ and IL-5 mRNA+ respectively. 88.7%-91.2% of IL-4 mRNA+ cells and 89.8%-90.6% of IL-5 mRNA+ cells were CD4+ T lymphocytes in OVA group. Aerosol administration of PPD markedly suppressed IL-4 and IL-5 expression, and lung eosinophil infiltration. It was more effective in pre-PPD group. 76.6%-78.0% of IL-4 mRNA+ and 73.8%-79.7% of IL-5 mRNA+ cells were CD4+ and 78.1%-84.9% and 78.4%-85.3% of the CD4+ cells were IL-4 mRNA+ or IL-5 mRNA+ respectively in pre-PPD group, both were markedly lower than that of OVA group. CD4+ percentage of IL-4 mRNA+ and IL-5 mRNA+ cells were 80.7%-82.0% and 78.0%-83.9% in post-PPD group, which were markedly lower than that of OVA group. CONCLUSIONS: Sensitization with PPD by intraperitoneal injection and then challenged by PPD inhalation markedly suppressed IL-4, IL-5 expression and eosinophil infiltration, and attenuated pulmonary Th2 reaction in ovalbumin sensitized mice. This induces Th1 type reaction and inhibits Th2 cell differentiation. It may be beneficial for glucocorticoids dependent or resistant patients.
OBJECTIVE: To study the significance of histological grading as a prognostic factor in breast cancer. METHODS: According to the grading systems of Bloom-Richardson and Elston, 476 cases of invasive ductal carcinoma (IDC) with more than 5 year follow-up were assessed for grade I (GI, 72 cases), grade II (G II, 216 cases) and grade III (G III, 188 cases). RESULTS: The 5 year survival rate for IDC G I, G II and G III were 81.9% (59 cases), 63.4% (137 cases) and 49.5% (93 cases) respectively. CONCLUSION: Histological grading of IDC is as good a prognostic factor as their clinical stage.
The paper firstly represents two cases of cholesterol granuloma of the maxillary sinus in China. The common symptoms of the disease include nasal obstruction and bone erosion in severe case. The disease is related to obstruction of the antral ostia, hemorrhage into polypoidal mucosal disease or cholesterol precipitation in the walls of antral cyst. A review of the literature on cholesterol granuloma suggests that poor ventilation in a closed space and long-standing inflammation with effusion or hemorrhage contribute to the formation of cholesterol granuloma. Long-lasting cure is achieved by radical maxillary sinusotomy which is the main therapeutic means.
OBJECTIVE: To study the effect of chitosan in the prevention of fibrous scar formation in the epidural space after laminectomy. METHOD: Fourty-eight SD rats were used as the animal model. Laminectomy was performed in lumber 1, and the exposed dura was covered with hyaluronate (group A), free fat (group B), chitosan (group C), and saline solution (group D) respectively. At 4, 8 and 12 weeks postoperation, scar formation was observed. RESULT: The results revealed that scar formed in the group D at the fourth week reached a peak at the eighth week and began to soften and constrict at the twelfth week. Sodium hyaluronate and chitosan had a significant efficacy in the prevention of scar formation, but the effect of chitosan was superior to that of sodium hyaluronate. CONCLUSION: The findings of this study indicate that chitosan has a preventive effect on scar tissue formation.
OBJECTIVE: To evaluate the therapeutic effects of phacoemulsification with foldable intraocular lens implantation through a clear corneal incision. METHODS: The surgery was performed through a 3.2 mm clear corneal incision on 100 eyes of 90 patients with senile, complicated, congenital and traumatic cataracts. RESULTS: Postoperatively, the visual acuities with spherical correction or without correction were 0.5 or better in 93.0% of eyes at one day, and 1.0 or better in 56.0%, 65.1% and 67.5% at one week, one month and three months respectively. The mean postoperative astigmatism was 0.93 +/- 0.58 D at one week and 0.20 D more than the mean preoperative one (P < 0.001). There was no statistical difference between the mean preoperative astigmatism and postoperative astigmatism at one and three months which were respectively 0.78 +/- 0.60 D and 0.73 +/- 0.59 D. CONCLUSION: The phacoemulsification with foldable intraocular lens implantation through a clear corneal incision can reduce early postoperative astigmatism, shorten the period of visual rehabilitation and simplify operative procedures.
The effects of emodin, cromakalim (KATP channel opener) glybenclamide (KATP channel inhibitor) Ba2+ and TEA on the electrical and contractive activities of the smooth muscle cells in guinea pig taenia coli and the relationship between emodin and four other drugs were studied by using intracellular microelectrode technique and the tension measuring technique. The results are as follows: (1) Emodin enhances the electrical and contractive activities of the smooth muscle cells in guinea pig taenia coli. The effects of emodin depend on its concentration. (2) Emodin can resist the inhibition of cromakalim on the electrical and contractive activities of smooth muscle cells. On the other hand, cromakalim was shown to suppress the effects of emodin. (3) Ba2+, TEA and glybenclamide all can improve the electrical and contractive activities of smooth muscle cells and resist the inhibition of cromakalim. The effects of emodin were found to be similar to that of glybenclamide but different from that of Ba2+ and TEA. The results suggest that the mechanism of action of emodin is to inhibit the activity of KATP channel in the guinea pig taenia coli smooth muscle cells.
To study the effect of ribozyme in vivo, the hammerhead ribozyme RzDS was designed and synthesized, which aims at the pregenome RNA of DHBV(LJ-76) at the 736 site of the genome. The RzDS cleaved efficiently its substrate in vitro. We constructed pJ-RzDS, in which RzDS was inserted into pJ120 plasmid under the control of PII promoter. After homogenous recombination with the vaccinia virus, Tian Tan strain, we got the recombinant(V-RzDS) which carried RzDS. V-RzDS was injected into nestling Beijing ducks preinfected with DHBV. On the tenth day after intravenous injection, DHBV DNA and DHBsAg in serum were detected. The quantity of DHBV DNA and DHBsAg were evidently lower than that of the controls, when V-RzDS injection was simultaneously given with DHBV. It suggests that RzDS can block replication and expression of DHBV in vivo.
With aging, melanocytes become unevenly distributed in the epidermis. In light skin individuals, hypopigmentation is found in association with focal hyperpigmentation (lentigo senilis). Apparently this results from progressive loss of active melanocytes and focal increase in melanocyte proliferation and/or aggregation. This paper summarizes the present knowledge on aging of melanocytes in vivo and in vitro, with a focus on the role of melanin as a determinant for proliferation and terminal differentiation. We describe that excessive melanin deposition by cyclic AMP-inducing agents results in increased expression of the cyclin-dependent kinase inhibitors p27Kp-1 and p21SDI-1/Waf-1, increased binding of p16 to CDK4, and terminal differentiation. Importantly, the efficiency with which the melanocytes exit the cell cycle depends on the melanin background of the donor's cells. Melanocytes from skin types IV-VI that accumulate large amounts of brown black melanin (eumelanin), lose expression of the transcription factors E2F1 and E2F2, two key regulatory proteins, and withdraw from the cell cycle more rapidly than melanocytes from skin types I and II that accumulate red/yellow melanin (pheomelanin). Thus, we propose that terminal differentiation is a tumor suppressor mechanism that becomes less efficient under imperfect eumelanization.
OBJECTIVE: To develop new methods for combining results from multiple outcome domains and to demonstrate their application in a study of the cost-effectiveness of clozapine in treating hospitalized patients with refractory schizophrenia. DATA SOURCES/STUDY SETTING: Interview assessments, and administrative utilization and cost data, concerning 423 patients with refractory schizophrenia who had been hospitalized for 30-364 days during the year before study entry, at 15 VA medical centers. STUDY DESIGN: A 12-month double-blind trial compared clozapine (n = 205) and haloperidol (n = 218) in the treatment of refractory schizophrenia. DATA COLLECTION/EXTRACTION METHODS: Data from standard assessment instruments, gathered at baseline and at 6 weeks, and at 3, 6, 9, and 12 months, were used to develop a Composite Health Index for Schizophrenia, a measure that addresses outcome in six domains, weighted by patient or provider preferences. Cumulative improvement was estimated by computing the area under the improvement curve. This measure was then combined with cost data, reflecting consumption of societal resources to estimate incremental cost-effectiveness ratios. PRINCIPAL FINDINGS: Clozapine was significantly more effective than haloperidol on measures of symptoms (p = .02) and side effects (p < .0001), with nonsignificant trends in the positive direction on community role functioning (p = .06), family relationships (p = .23), social relationships (p = .30), and daily activities (p = .20). Clozapine was also more effective than haloperidol on the one-year cumulative Composite Health Index for Schizophrenia (p < .0001 for all weighting schemes). After converting this measure to a 0-1 Worst Health-Good Health Scale analogous to Quality Adjusted Life Years, clozapine was found to yield a small improvement of .049 Worst Health-Good Health Units as compared to an improvement of only .027 Units for haloperidol (p < .0001). Average annual costs were $2,733 lower for clozapine (95% C.I. = -$9,220 to $3,754). Although clozapine was significantly more effective than haloperidol, the summary cost-effectiveness ratio had a wide 95 percent confidence interval ranging from -$431,585 to $177,352. CONCLUSIONS: Methods demonstrate an approach to using conventional disease-specific measures to evaluate the cumulative effectiveness of novel treatments for psychotic disorders and for expressing their economic effect as cost-effectiveness ratios. Among high hospital users with refractory schizophrenia, clozapine is more cost-effective than standard treatment, although the magnitude of its effect is small and there is considerable uncertainty about the cost estimates.
We have identified a highly polymorphic pentanucleotide repeat (CCTTT)n within the 5'-putative promoter region of the human inducible nitric oxide synthase gene (iNOS, NOS2). Using a pair of specific primers derived from the human iNOS gene, we have also amplified this iNOS repeat in DNA from the following species: chimpanzee, gorilla, orangutan and macaque. As is found in man, both chimpanzees and gorillas are polymorphic at this locus. In contrast, the locus is monomorphic in macaques and orangutans. While the average number of repeats is similar in gorilla and man, there are considerably fewer repeats in chimpanzees. A comparison of the sequences flanking the (CCTTT)n repeats among these closely related species demonstrates the presence of long stretches of homopurine-homopyrimidine residues. Similar polypurine/polypyrimidine stretches have been identified in the promoter regions of a number of other vertebrate genes where they have been associated with transcriptional regulation, although a role for the (CCTTT)n repeat array in the human iNOS gene has not yet been demonstrated.
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BACKGROUND: Clozapine, a relatively expensive antipsychotic drug, is widely used to treat patients with refractory schizophrenia. It has a low incidence of extrapyramidal side effects but may cause agranulocytosis. There have been no long-term assessments of its effect on symptoms, social functioning, and the use and cost of health care. METHODS: We conducted a randomized, one-year, double-blind comparative study of clozapine (in 205 patients) and haloperidol (in 218 patients) at 15 Veterans Affairs medical centers. All participants had refractory schizophrenia and had been hospitalized for the disease for 30 to 364 days in the previous year. All patients received case-management and social-rehabilitation services, as clinically indicated. RESULTS: In the clozapine group, 117 patients (57 percent) continued their assigned treatment for the entire year, as compared with 61 (28 percent) of the patients in the haloperidol group (P<0.001). As judged according to the Positive and Negative Syndrome Scale of Schizophrenia, patients in the clozapine group had 5.4 percent lower symptom levels than those in the haloperidol group at all follow-up evaluations (mean score, 79.1 vs. 83.6; P=0.02). The differences on a quality-of-life scale were not significant in the intention-to-treat analysis, but they were significant among patients who did not cross over to the other treatment (P=0.003). Over a one-year period, patients assigned to clozapine had fewer mean days of hospitalization for psychiatric reasons than patients assigned to haloperidol (143.8 vs. 168.1 days, P=0.03) and used more outpatient services (133.6 vs. 97.9 units of service, P=0.03). The total per capita costs to society were high -- $58,151 in the clozapine group and $60,885 in the haloperidol group (P=0.41). The per capita costs of antipsychotic drugs were $3,199 in the clozapine group and $367 in the haloperidol group (P<0.001). Patients assigned to clozapine had less tardive dyskinesia and fewer extrapyramidal side effects. Agranulocytosis developed in three patients in the clozapine group; all recovered fully. CONCLUSIONS: For patients with refractory schizophrenia and high levels of hospital use, clozapine was somewhat more effective than haloperidol and had fewer side effects and similar overall costs.
A nondestructive Kossel diffraction technique based on the principle of back-light scattering was used to characterize the structure formation which results from the interparticle interactions in colloidal dispersions. Static structure factors, radial distribution functions, and average pair potentials, which characterize the particle packing structures in model systems of hydroxylate latex dispersions, were obtained. The effects of particle concentration and polydispersity on particle structuring and dispersion stability were also studied. Computer simulations based on the Ornstein-Zernike method were compared with the experimental results. Good quantitative agreement was observed.
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