In order to have a better understanding of the relation between vertical dimension and occlusal force,a meter was made by means of straingauge.Five Japanese men were investi- gated for occlusal force at different vertical dimensions.The measurements showed that the maximal occlusal force of the posterior teeth occured at 8 to 15mm or the vertical dimension, the maximal occlusal forec of the anterior teeth occured at 13 to 18mm.This indicated that the occlusal force was closely related to the state of jaw closing muscle.

OBJECTIVE:To provide suggestions for the setting-up of the current pharmacovigilance(PV)system.METHODS:The characteristics of the setup of the PV system in both US and France were analyzed and the problems encountered in current monitoring system of adverse drug effects were pointed out.RESULTS & CONCLUSION:Both American and French PV systems have their own advantages and we should learn from it and draw useful experiences from them.In constructing PV system,China should make improvement in organization,communication,financial resource and information technology etc.

Animals ; Blood Glucose ; Cucurbita ; chemistry ; Diabetes Mellitus, Experimental ; drug therapy ; Hypoglycemic Agents ; pharmacology ; Lipids ; blood ; Oxidative Stress ; Polysaccharides ; pharmacology ; Rats

By means of histological and immunohistochemical methods,effects of a singleintraperitoneal injection of ethane dimethanesulphonate(EDS,75 mg/kg bodyweight)on the hypothalamo-pituitary-testicular axis of the rat were observed inthis study.Three days after administration of EDS,Leydig cells were eliminated;some LH cells in pituitary became larger or decreased in immunoreactivity;but nosignificant change could be found in hypothalamic GnRH system.Seven days afterEDS,degeneration of spermatogenic epithelium was marked,the staining intensity ofLH cells was generally reduced,the number of GnRH immunorcactive neurons inthe hypothalamus as well as the density and staining intensity of GnRH fibers andterminals in the median eminence were significantly diminished.Testosteronereplacement increased the number of late spcrmatids in testis and restored theabove-mentioned changes in the hypothalamus and pituitary.These results indicate that following administration of EDS,1)spermatogenesisdamage is resulted from destruction of Leydig cells and cessation of testosterone secretion;2)respective hormone release from hypothalamic GnRH system andpituitary LH cells is increased;3)loss of testosterone negative feedback is themajor factor responsible for the enhancement of secretory activity of the hypotha-lamo-pituitary axis;and that 4)EDS can be a useful experimental tool forstudying hypothalamo-pituitary-testiculer axis and intratesticular local regulation.

Gonadotropin-releasing hormone(GnRH)prohormone of human and rat consistsof GnRH and GnRH-associated peptide(GAP).In this study,three antisera againstN-terminal,mid-region and C-terminal of GAP,and ABC immunoenzyme methodwere used to observe the GAP neurons in the brains of the rat,mouse and guineapig.The distribution of GAP neurons in these animals was similar.GAP perikaryawere mainly present in the septo-preoptic area,with the largest concentration inthe diagonal band near the organum vasculosum of the lamina terminalis.SomeGAP perikarya were also seen in the brain area near the supraoptic nucleus.GAPfibers were widely present in the forebrain and hypothalamus,and terminated inthe organum vasculosum of lamina terminalis and median eminence.Of 3 GAP antisera,the one against N-terminal gave more immunoreactive elements and moreintense staining.The morphology and distribution of GAP perikarya,fibers andterminals were similar to those of GnRH.These results,combined with other relatedfacts,suggest that there is a common GnRH prohormone in mammals,and itsprocessing products,GAP(or cleavage fragments)and GnRH,are cosecreted intohypophysial portal system to regulate anterior pituitary hormone secretion.

The morphology of the GnRH neurons in the rat brain during postnatal development was studied quantitatively using the ABC immunostaining method and an image analyser. The pattern of distribution of the GnRH neurons in different ages animals used was similar. GnRH cells of rats aged 1-7 days were small in size with short processes, pale-stained, and smooth in outline The number of GnRH cells in 1 day rats was not significantly different from that of adult, but a significant decrease in the GnRH cell number appeared in 7 day rats. In postnatal day 14, Gn-RH neurons reached adult level in cell body size, number and staining intensity. The GnRH fibers and terminals in the median eminence were gradually increased and reached adult level up to 14 postnatal days. These results suggested that the number of GnRH neurons is determined shortly after birth; the second postnatal week is the critical period for the development of GnRH neuronal morphology; and the establishment of function of the GnRH neuronal system may be earlier than its morphological maturation.

By means of chromalum-hematoxylin and thiosulfate aldehydefuchsin stains the magnocellular neurosecretory neuron of the rat hypothalamus was studied. The cell body of neuron containing various amounts of secretory granules was large in size, with a variety of shapes. The axon of neuron showed an beaded appearance; only one in each neuron was very fine in diameter and left hypothalamic nuclei to form the hypothalamo-neurohypophyseal tract. The dendrite, in general, thicker than the axon, did not project outside of the nucleus. Many of the thick short dendrites did not contain secretory granules or only few secretory granules. The thick processes with more secretory granules were considered as dendritic processes. A number of axons and thick processes containing secretory granules also contacted with the endothelium of vessels and the ependyma of the third ventricle. In addition, a group of magnocellular secretory neurons were found in the sub-choroid plexuses of the lateral ventricle.

By means of ABC immunoenzyme technique, the distribution of GnRH neurons and fibers in the brains of rats and mice was observed, The results showed that more than 90% of GnRH neuronal perikarya were concentrated in the diagonal band-medial preoptic area near the organum vasculosum lamina terminalis, extending rostro-dorsally to the medial septic nucleus and caudo-laterally to the supraoptic nucleus region. No GnRH cell body could be found in the mediobasal hypothalamus, GnRH fibers terminated in the median eminence via the periventricular and lateral tracts. In the rostral median eminence, fibers were present in its entire layers and width, and caudally separated into two laterally-located bundles. The difference of GnRH system between rodents and primates, as well as its significance in reproduction are discussed.

Under pathologic conditions, nitric oxide causes peripheral insulin resistance by impairing key signal molecules of insulin signaling pathway and mediates dysfunction of islet ? cells caused by lipids, cytokines and hyperglycemia, which plays an important role in the pathogenesis of type 2 diabetes mellitus.

Objective To investigate the effects of ischemia reperfusion on the morphological changes of sinoatrial node(SAN) cells in rabbits in vivo . Methods Ninety healthy adult rabbits were randomly divided into 3 groups with 10 rabbits in control and every subgroup: control group [a suture passed under the root section of right coronary artery(RCA) without ligation], ischemia group(occluding the root section of RCA for 10, 30, 60 and 120 min respectively), ischemia reperfusion group(10, 30, 60 and 120 min ischemia after respectively followed by 4 hours′ reperfusion). Results ① Compared with control group, abnormal structure of SAN cells was not seen in 10 min ischemia group and 10 min ischemia reperfusion group with light microscopy, except slight mitochondrial swelling of SAN cells in former group with electron microscopy. ② There were morphological changes of SAN cells in 7, 6 and 8 rabbits in 30, 60 and 120 min ischemia group, presenting mainly as cellular swelling, karyopyknosis, and focal necrosis under a light microscope, and mitochodrial swelling, cristae disorganization or break under an electron microscope. The most severe cellular damages were found in 120 min ischemia group. ③ In ischemia reperfusion group, there were morphological abnormalities of SAN cells in 6, 8 and 7 rabbits in 30, 60 and 120 min ischemia reperfusion groups. The morphologic changes were similar to those in ischemia group, but injury degree was more severe than that in ischemia group with the same ischemic time. Conclusion Ischemia and ischemia reperfusion can induce morphological changes of SAN cells in a time dependent manner in rabbits in vivo , and the injury degree is more severe in ischemia reperfusion group than that in ischemia group with the same ischemic time.