[Pathogenic mechanism of entomopathogenic bacteria--Xenorabdus and Photorhabdus].
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Animals↗
Biomedical subjects
L Wang
Publications and source records attributed to L Wang.
[Infection of white spot baculo-like virus(WSBV) in Penaeus chinensis: evidence from electron microscopy and DNA hybridization].
Severe epizootic causing high mortalities in cultivated Penaeus chinensis has occurred every year in mainland China since 1993 with great economic loss. Naturally diseased P. chinensis sampled in Qingdao shrimp farming regions between 1993 and 1998 were examined by electron microscopy. A similar non-occluded nuclear bacilliform virus like the white spot baculo-like virus (WSBV) reported in Taiwan was mostly found in the gill, cuticular epidermis under the exoskeleton, stomach, lymphoid organ and other tissues of ectodermal and mesodermal origin from these diseased samples. The viron was enveloped with a mean size of (125 +/- 7.6) nm x (345 +/- 16) nm. Sometimes, a nipple-like appendage could be found protruding from one extremity of the viron. Envelopes were all lost after purification from cesium chloride gradient ultracentrifugation. The cylindrical nucleocapsid in negatively staining preparations was (80 +/- 13) nm x (380 +/- 24) nm with 13-16 stripes perpendicular to the longitudinal axis of the nucleocapsid. Based on its pathogenic and morphological characteristics, this virus should be related to WSBV. A pair of primers created from information of WSBV genome DNA SalI fragment produced a 355 bp band using the WSBV isolate from P. chinensis in mainland China, as the DNA template. The specific PCR product was cloned, sequenced and labeled with digoxigenin (DIG) DNA labeling kit (Boehringer Mannherm). The sequence of the probe is identical to that of WSBV. All of the sampled diseased shrimps between 1993 and 1998 reacted with the DIG-labeled probe by dot-blot hybridization and no hybridization was observed using DNA from health shrimp as templates. These results based on electron microscopy and DNA hybridization indicated that the shrimp epizootic occurred in mainland China was related to the WSBV infection previously occurred in Taiwan early 1992.
Animal Diseases↗
[Salt stress-induced apoptosis in plants--a possible resistance mechanism to salt stress].
Previous study has showed that apoptosis-like cell death can be induced under moderate salt stress in plants. In this paper, we studied the cell death induced by salt stress in maize, rice and tobacco roots utilizing DNA Laddering, paraffin sectioning-based TUNEL and chromosome spreading-based TUNEL simultaneously. The characteristic morphological and biochemical features showed apoptosis induced by salt stress may be a universal phenomenon in plants, but some differences may lie in various species. These results provided a valuable insight into studying the physiological mechanism of stress resistance in plants. In addition, we compared the in situ labelling technique based on chromosome spreading with that based on paraffin sectioning. We proposed according to the results that chromosome spreading-based in situ labeling technique should be suitable to detect individual cell death qualitatively and quantitatively with high efficiency, low background and detailed description of apoptotic changes at chromosome, nuclear and DNA levels.
Adaptation, Physiological↗
[Culture of human nasal respiratory epithelial cells in serum free medium supplemented with hormones and growth factors and measurement of human nasal ciliary motility using videomicroscopy].
OBJECTIVE: To establish a culture model of human nasal respiratory epithelial cells and a method of measuring human nasal ciliary motility. METHOD: The human nasal respiratory epithelial cells were detached with collagenase and cultured in serum free medium supplemented with hormones and growth factors, the ciliary beat frequency was measured by videomicroscopy. RESULT: After inoculation, cells cultured with this method adhered in 24 hours, confluented in 6-8 days and lived for 16 days. During that time ciliary beating was active, both acidic and neutral mucoitin granules were rich in goblet cells and all chromosome of 23 pairs were normal, the ciliary beat frequency in 29 subjects' nasal mucosa was (411 +/- 24) beats/min (mean +/- s). CONCLUSION: A culture model of human nasal respiratory epithelial cells in serum free medium supplemented with hormones and growth factors and a method of measuring human nasal ciliary motility was successfully established.
Cells, Cultured↗
[Role of beta-adrenoceptor antagonists in the control of kindling models in rats].
AIM: To study the role of beta-adrenoceptors (beta-AR) and their subtypes in the control of kindling models in rats. METHODS: Electrical amygdala kindling, pentylenetetrazol (PTZ) kindling models in rats and maximal electroshock (MES) in mice were used to observe the effects of beta-AR agonists and antagonists. RESULTS: The beta-AR antagonist propranolol 15 mg.kg-1 i.p. delayed the development of amygdala kindling; while propranolol 1-20 mg.kg-1 i.p. and beta-AR antagonist metoprolol 25-400 mg.kg-1 ig significantly increased the afterdischarge threshold and reduced the seizure severity in both kindling models (P < 0.01). beta 1-AR agonist dobutamine completely reversed the inhibitory effect of propranolol, while the beta 2-AR agonist terbutaline showed no effect on propranolol. Metoprolol 200 and 800 mg.kg-1 ig significantly inhibited MES in mice (P < 0.01). CONCLUSION: Central beta 1-AR is involved in the inhibitory effects on amygdala kindling and PTZ kindling models in rats.
Adrenergic beta-1 Receptor Antagonists↗
[Determination of glycyrrihizin in rats plasma and pharmacokinetics after oral administration of si-jun-zi-tang].
OBJECTIVE: To study the pharmacokinetics of glycyrrhizin after oral administration of Si-jun-zi-tang in rats and provide the experimental evidences for the prescription pharmacokientics of traditional Chinese medicine. METHOD: A RP-HPLC method was established for rapid determination of glycyrrhizin in rats plasma. After obtaining the blood sample at different time, the plasma concentration of GL were detected respectively. The data were processed by the software named 3P87 to find the pharmacokinetic parameters. RESULTS: A good linear relationship existed in the range of GL from 1.224 micrograms/ml to 38.656 micrograms/ml. Whole blood concentration-time course of GL after oral administration Si-jun-zi-tang was fitted to be a two-compartment model. GL in rats plasma which came from Si-jun-zi-tang was absorbed and distributed rapidly, but excreted slowly. CONCLUSION: This RP-HPLC method was sensitive, raliable and rapid, it can be used in absorption and metabolism of GL, also in detection of GL preparation. This experiment is prepared for further study of the tradtional Chinese medicine prescription pharmacokinetics.
Administration, Oral↗
[Protective effects of brain-derived neurotrophic factor on injured retinal ganglion cells of rats].
PURPOSE: To investigate in vivo the survival of retinal ganglion cells(RGC) after optic nerve crush with intraocular injection of Brain-derived neurotrophic factor (BDNF). METHODS: Sprague-Dawly(SD) rats were divided into normal control, crush control, medium treatment and BDNF treatment group, and every group had 20 eyes. RGC of adult rats were labeled with fluorogold. Seven days later, the optic nerve was intraorbitally crushed and BDNF was injected into the vitreous. Five, 7, 14, 21 and 28 days after crush, the numbers of RGC were counted. RESULTS: The densities of RGC began to decrease 7 days after injury, the number of RGC was 70.2% and 40.5% of normal controls on days 14 and 28, respectively. In the group with BDNF injection, RGC densities decreased on days 7, but RGC densities were much higher than that of controls on 7, 14, 21, and 28 days after injury (P < 0.01). CONCLUSION: BDNF administered intraocularly at the time of crush can protect RGC from injury and cell death.
Animals↗
[Vitrectomy combined with intraocular lens implantation for 103 selected cases of complicated ocular trauma].
PURPOSE: To observe the visual outcome of vitrectomy combined with intraocular lens (IOL) implantation in one operation for patients with complicated ocular trauma. METHODS: Clinical records were retrospectively reviewed in 103 patients with complicated ocular trauma (104 eyes) who underwent vitrectomy combined with IOL implantation in one operation. RESULTS: The series of cases included 35 patients with intraocular foreign body (IOFB), 37 with penetrating injury, 9 (10 eyes) with explosive injury but without IOFB, and 22 with blunt trauma. Preoperatively, visual acuity was no-light-perception to counting fingers in 88 eyes (87.1%) of 100 patients (101 eyes). Visual acuity improved in 94 eyes (93.1%) including 74 eyes (73.3%) with 0.1-1.5 postoperatively. Retinal detachment occurred in one eye during follow-up and cured with pars plana vitrectomy. CONCLUSION: Vitrectomy combined with IOL implantation in one operation can be a safe, fast and effective approach for visual recovery in selected patients with complicated ocular trauma.
Adolescent↗
[The development of an automatic blood collector controlled by microcomputer].
A new automatic blood collector developed by using microcomputer AT89C2051 is presented in this paper. Meanwhile its principles component block diagram and their functions' are introduced here. All clinical experiments have shown that it has the advantages of easy operation, reliable performance, lower price and so on. It is truly an ideal upgrade product of intravenous blood exampling. It would find various applications and would have a bright future.
Automation↗
[Use of Hopkins rod-lens coupled with grasping forceps sheaths for extraction of tracheobronchial foreign bodies].
OBJECTIVE: To study the clinical application of Hopkins rod-lens coupled with gasping forceps sheaths in the extraction of tracheobronchial foreign bodies. METHODS: Sixty-two patients with tracheobronchial foreign bodies were operated on with Hopkins rod-lens coupled with grasping forceps sheaths under direct telescopic view or TV watching. High frequency jet ventilation was used and BPs ECGs SaO2 were monitored in all cases. RESULTS: Sixty-two patients were all successfully operated on. The extraction was primarily successful in 90% of the cases; and secondarily successful in 7% of the cases. No death and serious complication occurred. CONCLUSION: Compared with conventional bronchoscopic foreign body extraction, this new instrument and technique make it possible for the operator to clamp and extract foreign body under direct telescopic view or TV watching. It has increased the accuracy and safety of bronchoscopic extraction of tracheobronchial foreign bodies.
Adolescent↗
[Endoscopic transnasal sphenoidal approach in hypophysectomy].
OBJECTIVE: To report the anesthetization and surgical method of transnasal-sphenoidal endoscopic approach in hypophysectomy. METHODS: Forty-two cases with pituitary tumor underwent tranasal-sphenoidal endoscopic surgery and 37 out of 42 accepted local anesthesia and sedation. RESULTS: No complications had occurred, the operations went successfully with less blood loss. Postoperative endoscopic follow-up period was performed at 6 to 35 months. The symptoms were improved in all patients. CONCLUSION: Our results show that transnasal-sphenoidal endoscopic approach under local anesthesia in the treatment of pituitary tumor seems to be a safe simple and valuable way.
Adolescent↗
[Effects of nitric oxide on ciliary beat frequency in the human nasal mucosa].
OBJECTIVE: To investigate the effect of nitric oxide on ciliary beat frequency in human nasal mucosa. METHOD: A primary culture model of human nasal mucosa epithelial cells was established and the effect of nitric oxide on ciliary beat frequency was observed by videomicroscopy method. The data were statistically analyzed using t-test. RESULT: L-arginine significantly increased ciliary beat frequency from (400 +/- 48) beats/min to (793 +/- 68) beats/min (n = 9, P < 0.001), D-arginine had no similar effect, while NOS blocker L-NAME inhibited the effect of L-arginine. CONCLUSION: Cells cultured by our method could synthesize NOS that made L-arginine produce NO that could increase ciliary beat frequency in the human nasal mucosa.
Arginine↗
[Clinical significance of elevated serum sICAM-1 in patients with nasopharyngeal carcinoma].
OBJECTIVE: To study the expression of serum sICAM-1(soluble intercellular adhesion molecule-1) and tissue ICAM-1 in nasopharyngeal carcinoma and its clinical significance. METHODS: Expression of ICAM-1 in frozen sections of 20 normal nasopharyngeal mucosa and 54 nasopharyngeal carcinoma samples were studied with immunohistochemical technique, and levels of serum sICAM-1 in 54 patients with nasopharyngeal carcinoma (NPC group) and 32 healthy adults (normal group) by ELISA. RESULTS: Positive expression (45/54) of tissue ICAM-1 and levels (2,044.48 +/- 640.05) microgram/L of serum sICAM-1 in NPC group were significantly higher than that of 2/20 and (313.70 +/- 114.98) microgram/L in normal group (P < 0.01, respectively), and there was a positive relationship between the expression of tissue ICAM-1 and levels of serum sICAM-1 in nasopharyngeal carcinoma(P < 0.05). The levels (2,177.31 +/- 642.13) microgram/L of serum sICAM-1 in patients with III-IV stages were higher than those (1,847.25 +/- 308.15) microgram/L in I-II stages (P < 0.05), and those (1,678.89 +/- 685.01) microgram/L in patients with no lymph node metastasis lower than that (2,134.34 +/- 609.60) microgram/L in lymph node metastasis (P < 0.05). The levels of serum sICAM-1 decreased significantly from (2,211.42 +/- 717.59) microgram/L to (926.55 +/- 207.72) microgram/L in disappearance of tumor and metastatic lymph node after radiotherapy (P < 0.01). CONCLUSION: sICAM-1 might be involved in the cellular immunopathogenesis of nasopharyngeal carcinoma, and the measurement of the serum sICAM-1 may reflect ability of neoplasm cell in freedom from host immunological surveillance. Dynamic measurement of serum sICAM-1 may be a useful objective index to evaluate NPC prognosis and curative effects.
Adult↗
[Expression of inducible nitric oxide synthase in human esophageal biopsies from carcinoma and precancerous lesions].
OBJECTIVE: To investigate the possible role of inducible nitric oxide synthase (iNOS) in esophageal carcinogenesis. METHODS: iNOS expressions in normal epithelial cells(NC), hyperplastic cells(HC), atypical hyperplastic cells(AHC) from grade I to III, carcinoma in situ(CIS), squamous cell carcinoma(SCC), and adenocarcinoma(ADC) were detected with immunohistochemistry. RESULTS: The positive rates of immunohistochemistry staining was 0 for NC, 2.5% for HC, 4.0%, 7.5% and 2.5% for AHC grade I to III respectively, 1.4% for CIS, 8.5% for SCC and 71.4% for ADC. CONCLUSIONS: There is a high expression of iNOS in human esophageal adenocarcinomas. Frequent expression of iNOS may be a potential event in ADC carcinogenesis. There is no correlation between iNOS and SCC carcinogenesis.
Adenocarcinoma↗
[Combined use of steroid hormone and low dose gossypol for antifertility and its mechanism in rats].
OBJECTIVE: To study the feasibility and the morphological mechanism of combined use of steroid hormone (methyltestosterone and ethinyl estradiol) and low dose gossypol for antifertility in adult Wistar rats. METHODS: We used methyltestosterone 20 mg/(kg.d), ethinyl estradiol 100 micrograms/(kg.d), and gossypol 12 mg/(kg.d) to feed male rats for 6 weeks via gastric intubation to induce infertility, then used gossypol 12 mg/(kg.d) alone for another 12 weeks to maintain infertility. Testicular sperm counts, cauda epididymal sperm motility, and sperm silver staining were used to determine infertility and morphology of sperm at the end of the two phases. Testicular morphology of the rats was observed from HE and PAS staining of paraffin sections. F1 generation of the rats would be examined in a series of behavioral tests after their 6-week recovery periods. RESULTS: There was no substantial change in testicular sperm counts of drugs-treated rats both for 6 weeks and 6 plus 12 weeks compared with that of control. But cauda epididymal sperm motility of drugs-treated rats went down to zero at the end of two phrases. The result of sperm silver staining showed that epididymal sperm were all deleterious of either segregation of sperm nucha from sperm head, or separation in annular granule of sperm tail. The observation of testicular morphology suggested that spermatogenesis is only partially affected. The ratios of stages II-III (9.3 +/- 3.4)% and stages IX-X (3.6 +/- 0.6)% were remarkably dropped, but that of stages IV-VI (36.7 +/- 5.0)% obviously ascended comparing with (26.8 +/- 1.7)%, (6.0 +/- 0.4)%, (24.5 +/- 2.7)% of control at the end of 6 plus 12 weeks. Moreover, no adverse effect was found in viscera tissue sections. CONCLUSIONS: Steroid hormone made the procedure of spermatogenesis slower and low dose gossypol caused all sperm lose their activity in epididymis. Both affect the process of spermatogenesis from different endpoints and successfully induce infertility in short term. Low dose gossypol not only executes its antifertility function in epididymis, but also affects the quality of spermatozoal production in testis by impacting the procedures of both acrosomal formation and spermatozoal elongation, so it can completely maintain infertility in long term. The infertility was reversible that the infertile rats can be recovery in about 6 weeks. Their F1 generation were proved to be normal through a set of behavioral tests.
Administration, Oral↗
[Male contraception of triptonide and its function mechanism].
OBJECTIVE: The male contraceptive mechanism in rats of triptonide, isolated from Multiglycosides of Tripterygium wilfordii (GTW), was investigated. METHODS: The dosage of triptonide was 200 micrograms/(kg.d), fed for 8 weeks via gastric intubation. Sperm counts, sperm motility, and sperm silver staining were used to test the antispermatogenic effect of triptonide; the study of morphology was learned from paraffin sections of testis and visceras of triptonide-treated rats; protamine was abstracted from testis by electrophoresis; using antisense mRNA of cyclin D1 and Cdk4 as prodes, we examined the expression of cyclin D1 and Cdk4 through hybridization in situ. RESULTS: Sperm counts (26.43 +/- 3.90) x 10(6)/g and sperm motility(66.0 +/- 6.8)% of triptonide-treated rats were substantially different from those of control, (41.15 +/- 5.51) x 10(6)/g (P < 0.01) and (88.0 +/- 2.0)% (P < 0.001). Paraffin sections of testis of triptonide-treated rats stained by PAS showed that the number of spermatids per 100 sertoli cells (9.15 +/- 0.33) was remarkably decreased compared with control's (10.73 +/- 0.38) (P < 0.001). At the same time, delaying sperm-released process was observed, which affects the nature course of sperm. And the extended vacuoles of vary sizes, the segregation of cells in lumens were also found in the cross-section of testis of rats treated with triptonide. In addition, the contents of protamine (4.6 +/- 2.2)% was extremely decreased, compared with the control's (40.6 +/- 7.2)% (P < 0.001). By using antisense mRNA of cyclin D1 and Cdk4 as prodes, we detected that the expression of the genes was notably increased in spermatids. CONCLUSIONS: The results suggest the antispermatogenic effect of triptonide is very well and it mainly plays its role on spermatids by increasing the expression of cyclin D1 and Cdk4, meanwhile, decreasing the biosynthesis of protamine. The appropriate target region of triptonide makes itself most potency to be a suitable male antifertility drug.
Animals↗
Experimental study of homium: YAG laser transmyocardial revascularization in acute ischemic settings with myocardial contrast echocardiography.
OBJECTIVE: To study the mechanism and effects of blood perfusion to the acute ischemic region of myocardium through Ho-YAG laser channels with myocardial contrast echocardiography. METHODS: To produce the model of acute myocardial ischemia, we partially ligated the left anterior decending (LAD) coronary artery of canine hearts between 1st. and 2nd. diagonal branches and then performed transmyocardial revascularization in this region with Ho - YAG laser. Myocardial contrast echocardiography was made with a new generation of ultrasound contrast agent and second harmonic imaging of this region before, after ischemia and after laser revascularization. Pictures were taken with "R" wave trigger skill. RESULTS: Acoustic density determing in the ischemia region (anterior wall) with MCE (myocardial contrast echocardiography) was obviously decreased (5.40 +/- 1.81) after the LAD was ligated,as compared with before (11.69 +/- 1.61, P < 0.01). It was increased remarkably after transmyocardial laser revascularization (TMLR) (11.2 +/- 2.01, P < 0.01) as compared with that when ischemia and approximated to that before ischemia (P > 0.05). There were no differences in acoustic density in the lateral wall (as control) among these comprehensive three periods (P > 0.05). Contrast in the laser region developed one cardiac cycle ahead of that in the non-ischemic normal region. CONCLUSION: Acute ischemic myocardium can be perfused by oxygenated blood from the left ventricle through Ho - YAG laser channels. Evidence of blood perfusion through laser channels during systolic phase was detected, and myocardial contrast ultrasonography using intravenous perfluorocarbon-exposed sonicated dextrose albumin may be regarded as a reliable method in the study of transmyocardial revascularization.
Animals↗
[Processing techniques of Vaccaria segetalis].
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Drugs, Chinese Herbal↗