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271.
DL Flynn DP Becker VM Dilworth MK Highkin PJ Hippenmeyer KA Houseman LM Levine M Li AE Moormann A Rankin MV Toth CI Villamil AJ Wittwer BC Holwerda 《Canadian Metallurgical Quarterly》1997,15(1):3-15
This paper is a review of the literature on the possible association between osteoporosis and oral bone loss, with an emphasis on radiological studies. Such an association was first suggested in 1960. Subsequent histomorphometric and microradiographic studies showed that after the age of 50 there was a marked increase in the cortical porosity of the mandible, with this increase being greater in the alveolar bone than the mandibular body; and that with this increase in porosity, there was a concomitant decrease in bone mass, which appeared to be more pronounced in females than in males, with the loss in bone mineral content estimated to be 1.5% per year in females and 0.9% in males. These studies also demonstrated a considerable amount of variation in the amounts of cortical and trabecular bone within and among individuals. Subsequent clinical studies reported associations between the bone densities of jaws and (1) metacarpals, (2) forearm bones, (3) vertebrae and (4) femurs. These studies indicated that women had lower mandibular bone mineral content (BMC) than men and that age-related loss of bone was more pronounced in women after the age of 50 years than in men of the same age, as was the case for the rest of the body. It was suggested that systemic factors responsible for osteoporotic bone loss may combine with local factors (periodontal diseases) to increase rates of periodontal alveolar bone loss. Although not all studies found associations between osteoporosis and oral bone loss, the conclusion of this review is that such an association exists; yet additional longitudinal investigations are needed to confirm this, and before the implications of this association could be fully utilized in clinical dentistry, inexpensive methods must be developed for sensitive and specific measures of oral bone loss. 相似文献
272.
Data Caching for XML Query 总被引:1,自引:0,他引:1
Webapplicationssupportedbydatabaseretrieve desiredinformationfrommultipledatabasebyissuing queriesagainstremotedatabaseserversacrossInter net.Delayeddatatransmissionsandlostdatapack agesoftendecreasetheirefficiency.Hence,aconsid erableamountofworkhasfocusedontheproblemof semanticcachingfortheseapplications[1-3],but mainlyfocusontherelationaldatabases.Asthenum berofwebapplicationsthatbackedbyXMLdatabase increases,sodoestheneedtoprovideefficient cachingmechanismssuitableforthenatureoftheex ten… 相似文献
273.
OBJECTIVE: To determine whether the nitrate content of human milk is influenced by maternal ingestion of water containing elevated nitrate levels. DESIGN: Prospective, nonrandomized, volunteer study. SETTING: Clinical Research Center at the University of Iowa Hospitals and Clinics, Iowa City. PATIENTS: Twenty healthy lactating women with infants older than 6 months. INTERVENTIONS: The mothers were asked to consume a minimum of 1500 mL of water containing 0 mg of nitrate per liter on day 1, 45 mg on day 2, and 100 mg on day 3 in addition to consuming and recording their dietary intake. Breast-feeding was permitted during days 1 and 2, but milk was expressed on day 3 and the infants were given alternate food sources. After each 24-hour study day, maternal urine and milk samples were collected and frozen. A modified cadmium column reduction method was used to determine spot urinary and milk nitrate content. RESULTS: The meant total nitrate intake from diet and water on days 1,2, and 3, respectively, was 46.6, 168.1, and 272.0 mg. Spot urine nitrate content on days 1, 2, and 3, respectively, was 36.0, 66.0, and 84.0 mg. Nitrate concentration of human milk on days 1,2, and 3, respectively, was 4.4, 5.1 and 5.2 mg/L. CONCLUSION: Women who consume water with a nitrate concentration of 100 mg/L or less do not produce milk with elevated nitrate levels. 相似文献
274.
JH Markovitz K Kulkarni P Goldschmidt-Clermont CI Kiefe P Rustagi P Sekar N Nanda 《Canadian Metallurgical Quarterly》1998,19(5):720-726
AIMS: To determine whether Asian Indians (Indians), a group known to have high rates of coronary heart disease, have increased platelet activation and fibrinogen levels relative to white Americans of European origin (whites). METHODS AND RESULTS: Forty healthy, non-smoking Indians, aged 25-45, were matched with 40 healthy whites for age (within 3 years) and gender. Platelet activation was tested in blood exiting a bleeding time wound at 1 and 2 min post-incision (wound-induced activation), as well as in venous blood stimulated in vitro with collagen, using whole blood flow cytometry. Other risk factors, including fibrinogen levels, family history of diabetes or coronary heart disease, fasting insulin and lipid levels, and Lp(a) were also assessed. Fibrinogen levels were higher among Indians than whites, even after adjustment for gender or family history of coronary heart disease (P < 0.05). Indians had higher levels of wound-induced glycoprotein IIb/IIIa binding and platelet secretion (P-selectin expression) than whites, with the greatest differences found when comparing the upper quintile of activation for each group (Ps < 0.05). Indians with a family history of coronary heart disease (n = 15) had higher levels of platelet secretion (wound-induced and in vitro) than Indians without a family history (Ps < 0.05), while the relationship was reversed among whites. Platelet activation measures were not consistently related to other coronary risk factors, while fibrinogen was related to triglyceride and insulin levels among Indians. CONCLUSION: Indians have elevated fibrinogen and platelet activation levels relative to whites. These factors may contribute to the increased coronary risk observed in Indians. 相似文献
275.
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277.
Dendritic lamellar bodies have been reported to be associated with dendrodendritic gap junctions. In the present study we investigated this association at both the morphological and electrophysiological level in the olivocerebellar system. Because cerebellar GABAergic terminals are apposed to olivary dendrites coupled by gap junctions, and because lesions of cerebellar nuclei influence the coupling between neurons in the inferior olive, we postulated that if lamellar bodies and gap junctions are related, then the densities of both structures will change together when the cerebellar input is removed. Lesions of the cerebellar nuclei in rats and rabbits resulted in a reduction of the density of lamellar bodies, the number of lamellae per lamellar body, and the density of gap junctions in the inferior olive, whereas the number of olivary neurons was not significantly reduced. The association between lamellar bodies and electrotonic coupling was evaluated electrophysiologically in alert rabbits by comparing the occurrence of complex spike synchrony in different Purkinje cell zones of the flocculus that receive their climbing fibers from olivary subnuclei with different densities of lamellar bodies. The complex spike synchrony of Purkinje cell pairs, that receive their climbing fibers from an olivary subnucleus with a high density of lamellar bodies, was significantly higher than that of Purkinje cells, that receive their climbing fibers from a subnucleus with a low density of lamellar bodies. To investigate whether the complex spike synchrony is related to a possible synchrony between simple spikes, we recorded simultaneously the complex spike and simple spike responses of Purkinje cell pairs during natural visual stimulation. Synchronous simple spike responses did occur, and this synchrony tended to increase as the synchrony between the complex spikes increased. This relation raises the possibility that synchronously activated climbing fibers evoke their effects in part via the simple spike response of Purkinje cells. The present results indicate that dendritic lamellar bodies and dendrodendritic gap junctions can be downregulated concomitantly, and that the density of lamellar bodies in different olivary subdivisions is correlated with the degree of synchrony of their climbing fiber activity. Therefore these data support the hypothesis that dendritic lamellar bodies can be associated with dendrodendritic gap junctions. Considering that the density of dedritic lamellar bodies in the inferior olive is higher than in any other area of the brain, this conclusion implies that electrotonic coupling is important for the function of the olivocerebellar system. 相似文献
278.
CI Chien KS Kirollos RJ Linderman WC Dauterman 《Canadian Metallurgical Quarterly》1994,1204(2):175-180
Monoclonal antibodies have been obtained by fusing mouse myeloma cells with spleen cells of mice immunized with crude thyroid membranes. Among the antibodies reactive with different thyroid antigenic components, three were found to specifically react with TSH receptor molecules. These antibodies displayed characteristic staining patterns on frozen sections of thyroid tissue from patients with various thyroid diseases upon identification of antibody binding by indirect peroxidase staining. No specific reactivity was detected with tissue from other human organs, such as pancreas, liver, fat, and muscle. The results demonstrate that the immunoperoxidase technique and the specificity of the monoclonal antibodies produced permitted the identification of cellular constituents that might be important antigens in autoimmune thyroid disease. 相似文献
279.
CI Jack M Lye F Lesley G Wilson RJ Donnelly CR Hind 《Canadian Metallurgical Quarterly》1997,51(7):423-426
A retrospective analysis of the clinical features, operative procedures, postoperative complications and subsequent survival of 70 (50 male) elderly patients undergoing surgery for lung cancer compared with 74 (53 male) younger patients treated at the same hospital during the same period was performed, to determine if elderly people with lung cancer are less likely to benefit from and/or tolerate surgery. The elderly group had to wait longer for operation (p = 0.001) and were more likely to have pre-existing disease (p = 0.019). In contrast, they had fewer recognised postoperative complications (p = 0.032) and there was no difference between the two groups in perioperative mortality and subsequent survival. Surgical treatment of localised lung cancer represents the best chance for cure and this study suggests that age should not be a consideration in the decision to operate or not. The patient's general state of health should be assessed and management decisions based on individual status rather than on age. 相似文献
280.