Biomedical subjects
Publications and source records attributed to L Zhou.
Based on the technology of three dimensions image forming and the arc stereotactic guided operator, this system has the advantages of locating precisely, convenient operation, and good result of curing. It has the imitation checking system of operation to guarantee the safe of patients.
In the present study, effects of leukotrienes on IL-6 production by mouse resident peritoneal macrophages were explored with a bioassay method involving IL-6 dependent murine hybridoma B9 cell line. The results showed that LTB4, LTC4 and LTD4 can enhance the production of IL-6 from cultured peritoneal macrophages of mice. The optimal concentractions for LTB4, LTC4 and LTD4 were found to be 1.45 x 10(-6), 6.9 x 10(-8) and 8.05 x 10(-8) mol.L-1, respectively. The results suggest that peptide leukotrienes might play important role on IL-6 production in the local milieu of inflammation.
In our previous study, the malignant phenotypes of the NIH3T3 cells, transformed with HPV-16 E6E7 genes, could be inhibited by the antisense RNA of HPV-16 E6E7. In this study, the antisense RNA of HPV-16 E6E7 was induced into the cervical carcinoma cells, caski, which contained HPV-16 DNA. The results showed that the cellular growth velocity was down regulated by the antisense RNA of HPV-16 E6E7, the ability of forming cellular colonies in soft agar medium and the tumorigenicity in nude mice of CaSki cells were also inhibited by the antisense cellular colonies in soft agar median and the tumorigenicity in nude mice of Caski cells were also inhibited by the antisense RNA. In addition, the decrease of the expression of viral early genes in carcinoma cells was detected with Western blot assay. It denoted that the phenotypes and the carcinogenicity of tumor cells were inhibited by the associated antisense RNA, and this may be one of the pathways inducing tumor cells reversion.
In our study, a non-radioactive cytotoxicity assay by using a Balb/C (H-2d) mice, P815(H-2d) cells and lactate dehydrogenase (LDH) system was established, in order to detect EB virus specific cytotoxic T lymphocytes(CTLs). In this study, we detected both the changes of primary CTLs and secondary stimulated CTLs. Spleen CTL activity assay showed that the levels of primary and secondary CTLs in recombinant EBV-LMP1 vaccinia virus group were more higher than that in control group, at the same time, obvious enhancement of EBV-LMP1 specific CTL activity was observed in experimental group immunized by Baculovirus system expressing EBV-LMP1 protein when compared with the normal mice group. This work proved that the LDH assay can be used to detect cytotoxic T lymphocytes.
This paper describes the design of a safety interlock used by X-knife system for preventing the linear accelerator gantry colliding with the treatment couch and the patient when the accelerator is rotating and irradiating X-rays. How to install and adjust the unit is also addressed in this paper. The unit has been successfully used in JX-100 X-knife system developed by the First Military Medical University.
This acticle describes a new target position simulator system of X-knife. It adopts a new method of simulating with target ball to ball hole as a substitute for the traditional way of simulating with target pointer to pointer. It has the advantages of precise localization, convenient operation and dependable repeatability. Clinical application has demonstrated that it is an ideal target position simulating wystem of X-knife.
The mechanical isocentre positional accuracy of the X Knife system is a very important technological parameter in the course of the X Knife therpy. In this paper, a film-concentric circle method for measuring the mechanical isocentre positional accuracy is introduced. A simulation ball set at the isocentre of the X Knife mechanical positional system, as a substitute for target, was imaged on a film (the simulation ball's image is a circle and its diameter is 8 mm), and a collimator was imaged on the same film (the collimator's image is also a circle and its diameter is 30 mm). The distance between these two circles' centres is the error of the isocentric system. This method has been used in our work.
OBJECTIVE: To study the effect of different animal skin on the transdermal speed constant of sinomenine. METHODS: Improved franz-cell was used for the transdermal study, pH6.8 phosphate buffer was used as the receptor and HPLC method was used for the determination of sinomenine through different animal skin. RESULTS: The transdermal speed constant of the skin of hareless mice was much close to which of person. The higuchi equation of sinomenine through skin of hareless mice stored under -20 degrees C for 0d, 3d and 7d were Q = 40.34t1/2 + 196, Q = 38.01t1/2 + 25.3, Q = 41.55t1/2 + 24.7 respectively. CONCLUSION: The results indicate that skin of hareless mice is suitable for the transdermal study of sinomenine, and the effect of storing time (0-7d) under -40 degrees C is not obvious.
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In this paper, direct determination of trace manganese is reported with graphite probe furnace atomic absorption spectrometry. It is shown that graphite probe furnace system has advantages in terms of accuracy, sensitivity, speed, simplicity. The proposed method has been applied to the determination of trace manganese in human hair with satisfactory results.
After atmospheric particulate matter was directly collected with graphite probe filters, the trace cadmium in APM was determined by graphite probe furnace atomic absorption spectrometry. The results showed that the absorbance (peak-area mode)and the concentration of cadmium had a excellent linearity in the range of 0-50 microg/L. The characteristic mass and detection limit (3 sigma) were 2.48 and 1.86 pg, respectively. Its relative standard deviation was 2.06% (n = 11). The results of analysis of the National Bureau of standards of America, Standard Reference Material (SRM) No. 1648, Urban Particulate Matter, gave a recovery of 90.15-99.29% with RSD of 4.09%. The method proved to be accurate, sensitive, rapid and simple.
A prospective outcome study to determine the efficacy and complications associated with posterolateral arthroscopic discectomy was initiated in April 1988. One hundred seventy-five patients with symptoms consistent with a lumbar disc herniation and correlative imaging studies were treated operatively, and 169 were available for followup evaluation. Fifty-nine patients with a central herniation or a nonmigrated sequestered fragment were treated using bilateral biportal posterolateral access, whereas 116 patients with radiographic evidence of a paramedial, foraminal, or extra-foraminal herniation were treated using the unilateral uniportal approach. The minimum duration of nonoperative management ranged from 3.5 to 28 months (average, 16 months), and all patients had a minimum of 24 months of postoperative followup. Outcome analysis indicated that 149 procedures were successful, whereas 20 (11.8%) procedures were failures because of persistent radicular symptoms that, in some cases, required open laminotomy. Complications associated with the procedures included one disc space infection, one transient peroneal neuropraxia, and four index extremity skin hypersensitivity. All of these complications resolved without sequelae, and there were no neurovascular complications directly related to the surgical approach.
We initiated a retrospective study to determine whether p53 status and thymidylate synthase (TS) protein expression in primary colon tumors influence recurrence and survival for patients with stage II colon cancer. Tumor specimens from 45 consecutive untreated patients with stage II colon cancer were examined for p53 and TS protein expression using immunohistochemistry. The median follow-up was 5.1 years. Eighteen patients had left-sided tumors, and 27 had right-sided tumors. Fourteen of 45 patients (31%) developed recurrence. p53 overexpression was detected in the tumors of 18 patients (40%); 10 patients (55%) with p53 overexpression recurred; and 4 of 27 (15%) without evidence of p53 overexpression recurred (P = 0.002). High TS expression was detected in the tumors of 16 patients (36%): 8 patients (50%) with high TS expression recurred, and 6 patients (21%) with low TS expression recurred (P = 0.027). Patients with p53 overexpression had a significantly poorer survival than did those patients without p53 overexpression (P < 0.001). High TS expression was associated with poor survival (P = 0.004). p53 overexpression and high TS expression were significantly associated with left-sided tumors (P = 0.003 and P = 0.022). Thirteen of 16 patients (81%) with high TS expression also overexpressed p53, and 24 of 29 patients (81%) with low TS expression did not manifest p53 overexpression (P < 0.001). p53 and TS expression in primary stage II colon cancer are associated and appear to influence recurrence and survival. In this pilot study, left-sided tumors demonstrate significantly more p53 overexpression and significantly higher TS expression than do right-sided tumors, which may explain the significantly poorer survival for patients with left-sided tumors.
The CD40 molecule expressed on endothelial cells has been shown to transduce activation signals resulting in upregulation of adhesion molecules. Herein, we studied the impact of CD40 engagement on the induction of tissue factor (TF)-dependent procoagulant activity (PCA) at the surface of human umbilical vein endothelial cells (HUVECs). First, we found that co-incubation of HUVECs with 3T6 fibroblasts transfected with the CD40L gene (3T6-CD40L) resulted in a clear induction of PCA which was not observed with control untransfected fibroblasts. The specificity of this finding was established by inhibition experiments using monoclonal antibodies (mAbs) blocking CD40 or CD40L. PCA induced by CD40 ligation was TF-related as it was not observed in factor VII-deficient plasma and was associated with the accumulation of TF mRNA. To investigate the role of CD40/CD40L interactions in the induction of endothelial cell PCA by lymphocytes, interferon (IFN)-gamma-stimulated EC were incubated with T cells in the absence or presence of anti-CD40 or anti-CD40L mAb. The 60-70% inhibition of PCA induced by these mAbs but not their isotype-matched control indicated that the CD40 pathway is involved in the induction of PCA resulting from interactions between activated HUVECs and T cells. We conclude that activation signals elicited by CD40 engagement on endothelial cells result in the induction of TF-dependent PCA. The CD40/CD40L pathway might therefore be involved in the development of prothrombic states during diseases associated with endothelial cell and T cell activation.
PURPOSE: Keratoconus is characterized by thinning and scarring of the central region of the cornea. Previous research showed that, in corneas obtained from patients with keratoconus, lysosomal enzyme activities are elevated, whereas levels of protease inhibitors such as alpha1-proteinase inhibitor are reduced. This study was undertaken to examine further the expression of a spectrum of proteolytic enzymes and protease inhibitors. METHODS: Corneal buttons were collected from patients with keratoconus, healthy subjects, and patients with other corneal diseases. Immunohistochemical staining was performed on paraffin sections. Enzymatic assays and western blot analysis were carried out for cathepsins B and G. In addition, an in situ zymography procedure was used to examine the gelatin- and casein-digesting activities in corneas with keratoconus. RESULTS: An enhanced staining was found with antibodies to cathepsins B and G. Enzymatic assays and western blotting confirmed that the levels of these two enzymes were elevated in corneas with keratoconus. No alteration was noted with any of the matrix metalloproteinase (MMP) family members and other enzymes and inhibitors examined, although in situ zymography did indicate an increase in net gelatin- and casein-digesting activities in corneas with keratoconus. These activities were mostly abolished by inhibitors for serine and cysteine proteinases, but not by those for MMPs and aspartic proteinases. CONCLUSIONS: Levels of cathepsins B and G are increased in corneas with keratoconus. These enzymes may contribute to the heightened in situ gelatin- and casein-digesting activities, leading to abnormalities in keratoconus.
Thirty-seven biopsy specimens from primary sites, 18 surgically removed metastatic neck nodes, and 18 surgically removed primary sites from 37 patients with hypopharyngeal carcinoma (HPC) were evaluated for the presence of Epstein-Barr Virus (EBV) infection by in situ hybridization (ISH) and polymerase chain reaction (PCR). Although some of normal lymphocytes in 6 of 18 metastatic nodes were positive by ISH, there were no positive results from HPC tumor cells themselves. Our results indicate that EBV-infected non-neoplastic cells such as lymphocytes can be a cause of false positivity, if a study were conducted with PCR alone. Because ISH for EBV-encoded early RNAs was highly sensitive, even more sensitive than PCR from paraffin-embedded samples in our study, this method should be the first choice for identification of EBV infection to avoid false positives.
Opioid receptors are synthesized in dorsal root ganglia and transported into peripheral terminals of primary afferent neurons. Activation of such receptors results in antinociceptive effects that are most prominent in inflammation. In addition, opioid receptors located on sympathetic postganglionic neuron terminals may be involved in these effects. This study investigates the peripheral analgesic efficacy of the mu, delta and kappa receptor agonists [D-Ala2,N-Me-Phe4,Gly-ol5]-enkephalin, [D-Pen2,5]-enkephalin and trans-(+/-)3, 4-Dichloro-N-methyl-N-[2-(1-pyrrolidinyl)-cyclohexyl]-benzeneacetamid e, the effective number of peripheral mu, delta and kappa receptors in relation to the development of inflammation and the contribution of sympathetic vs. sensory neurons by use of capsaicin and 6-hydroxydopamine, respectively. In Wistar rats with Freund's adjuvant-induced hindpaw inflammation, antinociceptive effects of intraplantar [D-Ala2,N-Me-Phe4,Gly-ol5]-enkephalin (1.0-32 microg), [D-Pen2,5]-enkephalin (10-100 microg) and trans-(+/-)3, 4-Dichloro-N-methyl-N-[2-(l-pyrrolidiny)-cyclohexyl]-benzeneace tam ide (10-100 microg) were evaluated by paw pressure test. These effects increased linearly between 6 and 24 hr, but did not change between 24 and 96 hr of inflammation, whereas the doses of the irreversible antagonists beta-funaltrexamine, [D-Ala2,Leu5,Cys6]enkephalin or (+/-)-(5beta,7a,8beta)-3, 4-dichloro-N-[3-methylene-2-oxo-8-(1-pyrrolidinyl)-1-oxaspir[4, 5]dec-7-yl]benzeneacetamide required to abolish the respective agonist effects increased between 12 and 96 hr. Pretreatment with capsaicin (30, 50, 70 mg/kg s.c. over 3 days) but not with 6-hydroxydopamine (75 mg/kg i.p. over 3 days) reversed the hyperalgesia in inflamed paws and almost abolished antinociceptive effects of all three agonists. These results suggest that the increased opioid agonist efficacy is due to an increased number of peripheral opioid receptors at later stages of inflammation and that peripheral opioid antinociceptive effects are primarily mediated by mu, delta and kappa opioid receptors on primary afferent neurons.
The trabecular meshwork (TM) is a specialized eye tissue essential for regulation of the aqueous humor outflow and control of the intraocular pressure. Disturbances of TM cells may lead to elevated intraocular pressure and glaucoma. This study assessed the dexamethasone effects on levels of extracellular matrix proteins and their integrin receptors in bovine TM cells. Instillation of glucocorticoids such as dexamethasone is known to result in ocular hypertension. The histologic changes induced resemble those seen in glaucoma. Examination of the effects of glucocorticoid therefore may provide insights into the pathogenesis of glaucoma. TM cells in either tissue culture or organ cultures were treated with 0 (control), 0.1, or 1 microM of dexamethasone for 72 h. Immunostaining, Western, Northern and dot blot analyses showed that dexamethasone caused an increase in levels of fibronectin and collagen type IV in tissue-cultured TM cells. Increased focal contacts were also observed but the levels of laminin and collagen type I were unaffected. The dexamethasone effect was similarly demonstrated in organ cultures, with the exception that collagen type I also was enhanced. These results suggest that dexamethasone modulates extracellular matrices in the TM. Glucocorticoid may exert its effect through such a modulation in the development of steroid glaucoma.