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Volume ， Issue 2 ， 1991
- Abstract：<正> The highly specific ligand of the N-acetylcholine receptor（N-AChR）,alpha-bungarotoxin,was used to determine the effect of soman,sarin and VX onN-AChR of the diaphragm and extensor digitorum Iongus muscle of mice andrats.The effects of the three anti-cholinesterase agents on N-AChR weredifferent.Sarin did not act directly on N-AChR and cause a change in the numberof N-AChR.VX decreased the binding sites of the receptor by binding with N-AChRdirectly.The LD50was 0.054mg/kg in mousse.Soman increased the binding sites,e.g.1～1.5 LD50soman increased the number of N-AChR of mouse diaphragm by 25%.The peak increaseof N-AChR was reached 0.5 h after poisoning and could last 96h.The receptornumber was still 22% higher than that of the control on the fourth day aftersoman poisoning in rats.Soman mainly increased the number of extrasynapticN-AChR,leading to the enhancement of sensitivity of cholinergic effectors toacetylcholine（ACh）,which is similar to the hypersensitiveness resulting fromdenervation.These findings are of significance in probing the receptor mecha-nisms and treatment of soman poisoning.0|7|0Updated：2026-03-12
- Abstract：<正> The feature of porous titanium is that new bone trabecular tissue could ingrow intoits pores and produce interlocking attachment.The spherical TC4 powder and titanium fiberwere seperately implanted into the femurs of 24 dogs.The pore size of the samples was0.24mm and their rates of porosity were 40%～50%.After 3 months,the interface shearstrength examined by straight pulling test,was over 4.60±0.36MPa.Scanning electronmicroscopy showed that there were new bone components in the porous layer.Lightmicroscopy also revealed that there were new bone lacunae and their pathways in it.Thedepth of the reforming bone was 3 mm.Interface shear strength of the new bone in the po-rous layer might meet the need of load bearing.Porous materials would prevent the artificialjoint from loosening and thus help to develop a new service clinically.0|4|0Updated：2026-03-12
- Abstract：<正> A method of treating pulpless coloured anterior tooth is presented.Most part ofthe coloured dentin of the labial crown was removed and the dental structure was bleachedwith 30% hydrogen peroxide for 5min.The pulp cavity was then filled with whitephoto-curing composite.The result of the treatment is quite satisfactory.With our treatment,the intact contour of the crown and the hardness and gloss of the enamel are preserved.SEM proved that the composite was tightly bound with the enamel of the medial wall of thepulp cavity,forming an entity with the tooth,thus guaranteeing the strength of the crown.0|8|0Updated：2026-03-12
- Abstract：<正> Effects of serotonin（5-HT）and noradrenaline（NA）on neuronal activities of the sol-itary tract nucleus（NTS）were investigated in rat medullary slice preparations.After perfusingthe slice with 5-HT,the spontaneous discharge was significantly increased in 25（of 43,58.1%）NTS neurons,reduced in 13（30.2%）and not changed in 5（11.7%）.After perfusingthe slice with NA,the spontaneous discharge was significantly reduced or even completelyceased in 27（62.8%）neurons,increased in 13（30.2%）and not changed in 3（7%）.Therewere 38（88.4%）neurons responding to both 5-HT and NA.From the 38 neurons,21 wereselected for studying the effect of ketanserin.It was found that ketanserin potentiated the ef-fect of NA on spontaneous discharge in 10（47.6%）neurons and attenuated it in 4（19.0%）neurons.These results suggest that there is an interaction between 5-HT receptorand α-adrenoceptor at the NTS level.This interaction may be helpful in explaining themechanism of the central antihypertensive action of ketanserin.0|6|0Updated：2026-03-12
- Abstract：<正> This study was designed to evaluate whether the microvascularanastomosis of small arteries and veins in the wound area was possible after gun-shot wound was inflicted to the maxillofacial region of a dog.It was found thatsmall vessels could be connected with subsequent patency of their lumen if theoperation was performed on the 3rd day after the debridment of the gunshotWound,which provides a basis for microvascular anastomosis to repairmaxillofacial defect due to gunshot wound with free vascularized flap grafting.Inaddition the best time to have a defect repaired and the healing features of thewounds after vascular anastomosis are discussed.0|3|0Updated：2026-03-12
- Abstract：<正> The present study made in 92 mice showed that hydrogen peroxide com-pound injected directly into the tumor could to some extent sensitize the hypoxiccells of S180 solid tumor to radiate,for example,both the tumor regression rateand the mouse survival rate 40d after radiation in the hydrogen peroxide com-pound group were significantly greater than those in the radiation alone group.The increasing rate of tumor diameter in 10d was 77.10%,47.09%,and 47.47%-10.4% in groups of control,radiation alone,radiosensitizer alone,radiationand hydrogen peroxide compound,respectively.Some of the problems aboutthe intratumoral injection of radiosensitizer were discussed.0|3|0Updated：2026-03-12
- Abstract：<正> Cholesterol,a major lipid component of plasma membrane,is thoughtto have profound effects on the structure and function of cells.Mostanimal tis-sues are capable of synthesizing cholesterol de novo from acetate;however,thereare relatively few mammalian cells in vitro expressing an absolute requirement foran exogenous source of cholesterol.In this paper,it was shown that IR983F（983）rat myeloma cells and P3X63-AgS-U1（P3U1）and P3X63-Ag8.653（653）mousemy eloma cells which had been cultivated in serum-free medium for more than 6months required cholesterol in vitro for growth in serum-free medium.Optimalgrowth of P3U1,653 and 983 occurred in cholesterol concentration of 5,10 and15μg/ml,respectively.Moreover,it was demonstrated that the cholesterol couldbe replaced by human low density lipoprotein in a concentration of 10μg/ml butnot by mevalonic acid lactone.In contrast to the parental myeloma cells,hybridoma cells derived from the mouse myeloma cells which had been cultivatedin serum-free medium for more than 6 months did not require cholesterol.0|6|0Updated：2026-03-12
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Effects of ventromedial hypothalamic somatostatin on gastric somatostatin and acid secretion in rats
Abstract：<正> The effects of somatostatin and cysteamine injected into theventromedial nucleus of hypothalamus（VMH）on somatostatin-likeimmunoreactivity（SLI）concentration in the gastric antral mucosa and portal veinplasma,as well as the gastric acid secretion were studied in anesthetized rats.TheSLI concentration in the gastric antral mucosa and portal vein plasma and thegastric acid output were significantly increased one hour after the injection ofsomatostatin（0.5μg/0.5μ1）into the VMH.Four hours later,the SLI concentrationin the mucosa was still higher than the control level,while the SLI level in theplasma and the acid secretion were close to those of controls.On the contrary,the SLI concentration in the mucosa and plasma and the acid output weremarkedly decreased at four hours after the injection of cysteamine（15μg/0.5μ1）into the VMH.The present results suggest that both exogenous and endogenoussomatostatin in the VMH have a facilitatory action on the gastric somatostatinconcentration and its release as well as on the gastric acid secretion,thus provid-ing evidence for hypothalamic control of gastric somatostatin and acid secretion.0|5|0Updated：2026-03-12 - Abstract：<正> Diepithelialized tissue flap（DTF）with vascular anastomosis was de-signed in August 1987,and was used for the repair of 12 cases of large intraoraltissue defect.All the operations were successful.The clinical data were reportedand the procedure to incise and transplant a DTF described.When the healingprocess and changes of DTF after transplantation were observed,it was foundthat a layer of new smooth epidermis was formed on the surface of the DTF.Theorigin of this new epidermis was discussed.Ten out of the 12 cases have been fol-lowed up for from half a year to 2 and a half years,and the results weresatisfactory.The new epidermis showed no hair growth and the patients did nothave any rough feeling,which usually occurred after ordinary skin grafting.It isbelieved that DTF transplantation is likely an ideal method for the repair andreconstruction of intraoral soft tissue defect.Its disadvantage was that the DTFcontracted severely after healing.Finally the authors put forward the problemsconcerning the transplantation of DTF,which should be investigated further.0|5|0Updated：2026-03-12
- Abstract：<正> A proper landing posture is significant to the reduction of both the im-pact force acting on the human body and the injury at landing.In this paper theimpact force acting on human feet is studied.The subjects were 3 maleparachuters.The experiments were performed by means of high-speed photography and amotor analyzer.The experimental results are as follows:（1）When the subjectjumped from two platforms 1.0m and 1.5m in height,a vertical impact force onthe feet in half-squat posture was larger than in side spin posture.（2）When thesubject jumped from the platform 1.0m high,the feet gained a horizontal impactforce in the half-squat posture,larger than in the side spin posture.When thesubject jumped from the platform 1.5m high,the horizontal impact force pro-duced by both of the above-mentioned postures were just the same,which needsfurther research.（3）In terms of reducing the impact force acting on the feet,theside spin posture is better than the half-squat posture.0|8|0Updated：2026-03-12
- Abstract：<正> Cytochemical methods were used to evaluate the changes of intracellularcalcium,plasma membrane permeability and their relationship during ischemia andreflow in rat renal proximal tubule epithelial cells.In addition,the preventive ef-fects of inosine and Ligusticum wallichii on ischemia and reperfusion cell injurywere studied.The results showed that the preventive effects of inosine andLigusticum wallichii were obvious.Redistribution and slight increase of calciumoccurred during the ischemic period in the proximal tubule cells.In this periodthe changes of plasma membrane permeability were gentle.Following the exten-sion of reflow time,a large amount of calcium deposited in the cells andmitochondria.The plasma membrane became broken.There was a positivecorrelation between the calcium level in mitochondria and that in cytoplasm.0|4|0Updated：2026-03-12
- Abstract：<正> The effects of butyric acid（BA）on the nuclear ultrastructure of humanlung giant cell carcinoma（Strain PLA-801 D）were observed with digital imageprocessing.It was found that the length of the nuclear circumference of the tu-mor cells incubated with 2mmol of BA was approximately equal to that of thecontrol whereas the nuclear area was increased by 1.4times,which implies thatthe nuclear profile tends to become more regular after BA treatment.In addition,the optical density of the nuclei of the experimental group decreased significantlyas compared with that of the control,which indicates that the chromatin in thenuclei was decreased by BA.It was concluded on the basis of the findings thatBA may have a biological effect of reverse-transformation on the malignant cells.0|3|0Updated：2026-03-12
- Abstract：<正> Effects of hexametazidine [1,4-di（2,3,4-trimethoxybenzyl）piperazine]on the physiological properties of guinea-pig papillary muscles were investigated.Hexametazidine possesses a concentration-dependent negative inotropic effect(IC50=81.8±16.9μmol/L).The effect of hexametazidine（30.8μmol/L）was antago-nized completely by increasing the concentration of Ca2+from 1.8 to 5.4mmol/L.Hexametazidine（30.8μmol/L）increased the threshold concentration of adrenalinefor inducing the automaticity of the muscles from 3.95±1.80 to 6.67±4.84μmol/L（P<0.05）.It prolonged the functional refractory period from 218±14 to 254±20ms（P<0.05）at the concentration of 61.6μmol/L.Hexametazidine（6.2μmol/L）antago-nized the positive inotropic effect of isoprenaline competitively and ofhistamine non-competitively（pA 2 and pD2′ values were 5.45 and 4.13,respectively）.0|2|0Updated：2026-03-12
- Abstract：<正> The effects of IFN on the colony-forming ability,phagocytosis andmorphology of cells of murine CFU-GM were reported.The results showed thatIFN could inhibit the proliferation of CFU-GM,but 100IU IFN might promotethe phagocytosis of macrophagocytic cells.The significance of IFN in the regula-tion of hemopoiesis and the pathogenesis of aplastic anemia was discussed.0|7|0Updated：2026-03-12
- Abstract：<正> The effects of nitroquine on the sporogony of Plasmodium yoelii werestudied with electron microscope.The drug was given by feeding female mosqui-toes directly in the form of mixture with sucrose solution.Scanning electronmicroscopic studies revealed that the oocysts were smaller and markedly degener-ated.Surface of the oocysts was rough and uneven.Under transmission electronmicroscope,the cytoplasm of the affected oocysts contained vacuoles.Mitochondrial and nuclear membrane was damaged.The number of residualbodies increased.Formation of sporoblast did not occur in most of the affectedoocysts.The nuclear membranes of the degenerated sporozoites became thick-ened and the density of nucleus matrix markedly decreased.The results indicatedthat nuclei and the membrane system were mainly affected.0|1|0Updated：2026-03-12
- Abstract：<正> Our previous experiments demonstrated the occurrence of retinal lipidperioxidation following vitreous hemorrhage.In the present study,0.2ml ofautologous whole blood was injected into the vitreous of both eyes in rabbits.One eye of each rabbit received an additional injection of 0.2ml of superoxidedismutase （SOD,794 U）;the other eye served as a control.The malondialdehyde（MDA） in the retina was assayed with fluorescence spectrophotometry.The resultsshowed that the MDA was significantly lower in eyes injected with SOD （0.047±0.010 nmol/mg） than in control eyes （0.096±0.011 nmol/mg,P<0.05） 10d afterinjection.Ultrastructural examination revealed that the photoreceptor cells of theeyes with SOD injection were relatively normal.It is suggested that SOD can pro-tect the retina from lipid peroxidation.0|4|0Updated：2026-03-12
- Abstract：<正> This paper reports that 8 patients with carotid body tumors were diag-nosed by B-mode ultrasonic imaging.Among them,only 3 were originally clinicallydiagnosed as having the disease.The features of carotid body tumors in the 8cases,seen by B-mode ultrasonogram,are described.It is considered thatultrasonography of carotid body tumors is specific,trauma-free,accurate andsimple,and it may be an important method in identifying and diagnosing the dis-ease.0|13|0Updated：2026-03-12
- Abstract：<正> The rhinologist participating in microsurgery of the pituitary adenomaplays an important role in relieving the patients from suffering and indecreasing the incidence of complications.This paper summarily reportsrhinological aspects in 100 cases undergoing trans-nasosphenoid intrasellarmicrosurgery,including operative routes and incisions,methods for opening andreconstructing the sellar floor and nasal comPlications.The authors suggest aseptavestibular incision to modify Hirsch’s septal incision,and outline our fivemethods to open and reconstruct the sellar floor.The operator should select themost proper method according to different situations,in operation.The most dan-gerous complications are CSF rhinorrhea with supurative meningitis and fatalhemorrhage.In our experience five such cases were cured by medical and surgicaltreatments.0|5|0Updated：2026-03-12
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