ABSTRACT
The mandibular condyle formation during temporomandibular joint (TMJ) development exhibits endochondral bone formation, and the elongation process is dependent on the normal cartilage proliferation and differentiation. Retinoids are important for maturation of growth-plate chondrocytes, but the identity of their downstream effectors remains unclear. In this study, we carried out a series of studies at the cellular, biochemical, and molecular levels to determine whether, and if so how, retinoid signaling is related to the expression and function of Indian hedgehog (Ihh) in chondrocyte proliferation. First we analyzed the RA receptor (RAR) and Ihh expression pattern in E18 mandibular condyle. <i>RARα<i/> and RARβ</i> mRNA were characterized in the perichondrium around the condyle, whereas <i>RARγ</i> mRNA was expressed in the immature and prehypertrophic chondrocytes and the expression was overlapped with Ihh gene expression. Next we established a high-density culture model of chick cephalic chondrocytes in the prehypertrophic stage. We found that all-trans retinoic acid (RA) induced Ihh mRNA gene expression in this system. The RA pan-antagonist Ro 41-5253 inhibited both endogenous and RA-induced Ihh mRNA in a dose-dependent manner. The Ihh mRNA expression induced by RA required <i>de novo</i> protein synthesis, and was mediated by RARγ. Immunoblots showed that the prehypertrophic chondrocytes contained sizable levels of phosphorylated p38 mitogen-activated protein (MAP) kinase that were time- and dose-dependently increased by the RA treatment. Experimental p38 inhibition led to a severe drop in baseline and RA-stimulated Ihh expression. Exogenous recombinant Ihh stimulated the proliferation of proliferating chondrocytes, whereas RA inhibited the proliferation of these chondrocytes through p38 MAPK. Retinoids appear to play a primary role in controlling both the expression and function of Ihh in prehypertrophic chondrocytes and do so via p38 MAP kinase.
ABSTRACT
To review the outcome of our vaccination program against influenza, an investigation was made into the incidence of this acute infectious disease in our community from 2002 through 2004.Enrolled for this retrospective study were 1) all vaccinated individuals, 2) those who underwent nasal examinations by use of the swab, and 3) patients diagnosed as contracting influenza.The number of those administered with influenza virus vaccines increased year after year during the period under review. Over 70% of them were those aged 65years or above. The mean age of those who caught influenza was 42.9±21.3 in 2002, 34.9±20.4 in 2003 and 45.4±20.2 in 2004. Compared with unvaccinated old people, many unvaccinated young and middle-aged people contracted influenza, but among the vaccinated old people, there were some who came down with the flu.Morbidity was low for the old people whose vaccination rate was high.Therefore, it can be said that vaccination was effective in achieving adequate immunity. Nonetheless, for all the preventive injection, the fact that people of advanced age could be infected should be taken note of.
Subject(s)
Influenza, Human , Vaccination , Retrospective Studies , HospitalsABSTRACT
We report 3 cases of sudden death while the students are at school. In Japan 120-150 cases, mainly related to sports, are reported in a year. In Gifu Prefecture (population: 2, 000, 000), only 1 or 2 cases probably occur in a year. While here in Mizunami City (population: 40, 000), we had 3 cases for the last 10 years. This is a higher occurrence rate than in other cities.<BR>The 1st case was caused by brain-stem bleeding; the 2nd, rupture of the wall of the aorta associated with Marfan syndrome, and the 3rd, fatal arrythmia related to Wolff-Parkinson-White syndrome.<BR>Measures to prevent the incidence are summed up as follows:<BR>(1) Teachers, school doctors and hospital staffs should have closer contact<BR>(2) We should critically review the standards for cardiac disease management and make a thorough examination of the heart at the time of regular health screening by several ways, such as UCG, Holter ECG and treadmill ECG, to find high-risk students.<BR>(3) 60% of the cases of sudden death were of cardiac origin, and 40% were due to central nervous system disorder, bronchial asthma etc., so we should also watch over these conditions.