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Biomedical subjects

R Baez

Publications and source records attributed to R Baez.

7 recordsLinked to original sources
PubMed2001

Salt fluoridation and dental caries in Jamaica.

PURPOSE: In 1987, Jamaica initiated a comprehensive island-wide salt fluoridation program. A survey was conducted in 1995 to monitor the impact of salt fluoridation among children in Jamaica. METHODS: Dental examinations of 1,120 children aged 6-8, 12, and 15 years were conducted according to World Health Organization criteria to assess dental caries, fluorosis, the presence of and need for dental sealants, and Community Periodontal Treatment Needs (CPI). RESULTS: Age specific DMFT means observed in 1995 were 0.2 at age 7, 0.4 at age 8, 1.1 at age 12 and 3.0 at age 15. The mean DMFT scores in children 6, 12 and 15 years of age were dramatically lower than the corresponding scores of 1.7, 6.7 and 9.6 obtained at the baseline examination in 1984 for children of the same age groups, respectively (baseline data for 7- and 8-year-olds were not collected). The mean percentage of sound permanent teeth for all age groups was 90% in 1995. The percentage of children caries-free at baseline was 27.6% for 6 years, 2.8% for 12 years and 0.3% for 15 years of age. In 1995, the percentage of caries-free children (permanent teeth) was 61%. In 1984, 23 children were scored as having very mild or mild fluorosis. In 1995, five children were scored in the same categories of fluorosis, using Dean's criteria; thus, fluorosis remained at negligible levels in 1995. CONCLUSIONS: The oral health survey conducted in Jamaica in 1995 indicated a significant decline in dental caries compared with findings in 1984. The major change in Jamaica during the interval was the introduction of salt fluoridation in 1987. Dental fluorosis was low in the 1995 survey.

Adolescent↗
PubMed2000

Methyl jasmonate reduces chilling injury and maintains postharvest quality of mango fruit.

Exposure of mango (Mangifera indica cv. Tommy Atkins) fruit to methyl jasmonate (MJ) vapors (10(-)(4) M) for 24 h at 25 degrees C reduced chilling injury during subsequent storage for 21 days at 7 degrees C and after 5 days of shelf life at 20 degrees C. The chilling tolerance induced by MJ was positively correlated with the reduction in the percent ion leakage of mango tissue. The overall quality of MJ-treated fruit was also better than that of control fruit. MJ treatment increased the total soluble solids but did not affect titratable acidity or pH. MJ also did not change the normal climacteric rise in respiration, water loss, and softening rates. The efficacy of MJ to reduce chilling injury and decay of mango could be related to the tolerance induced at low temperature. It was concluded that MJ treatment may prevent chilling injury symptoms of mango without altering the ripening process.

Acetates↗
PubMed2000

Impairment of Leishmania mexicana phagocytosis in peritoneal macrophages induced by Amaranthus leucocarpus lectin.

The lectin from Amaranthus leucocarpus (ALL) is specific for N-acetyl-D-galactosamine and inhibits phagocytosis of Leishmania mexicana promastigotes in Balb/c mice peritoneal macrophages by 38%. The lipophosphoglycan (LPG) purified from L. mexicana inhibits penetration of promastigotes into peritoneal macrophages by 31%; interestingly, treatment of macrophages with both, ALL and LPG, inhibits phagocytosis of promastigotes by 72%, confirming that ALL induces modification of the macrophage's phagocytic activity by a different route than mannose or C3b receptors. The Inhibitory effect of ALL was time-dependent. N-acetyl-D-galactosamine (GalNAc) or O-glycosidically linked glycoproteins modified macrophage phagocytosis of Leishmania. These results suggest that macrophage membrane glycoproteins, possessing constitutive GalNAc, can influence the signaling pathways used by this intracellular parasite to infect.

Animals↗
PubMed1992

Marginal accuracy and geometry of cast titanium copings.

The biocompatibility of titanium with human tissue is well established; its potential as an alternate metal for crown restorations has yet to be fully investigated. This study measured the geometry and accuracy of coping margins cast in Ti, 99.5% chemically pure. Twenty castings with 45-degree facial and 90-degree palatal margins were made by indirect technique with a commercial system using recommended procedures. They were then cemented with ZnPO4 cement. The coping and die assemblies were embedded in resin, sectioned longitudinally, and measured with a microscope at x50 power. Casting shrinkage was characteristic, particularly along the horizontal axis in the plane of the shoulder. Although horizontal linear shrinkage of 45-degree margins was greater than that for the 90-degree form, the surface of marginal discrepancy was greatest with the 90-degree configuration.

Analysis of Variance↗
PubMedDate not supplied

Optimization of hybrid composite properties.

Hybrid composites have been a popular class of a wear-resistant posterior composite restorative material. The purpose of this study was to determine the effect of hybridization on the physical properties of a composite with different amounts of submicron silica (0.04 microns) with semiporous strontium glass (1.4 microns ave. by number/5 microns ave. by volume) in a Bis-GMA based resin system. As the submicron content increases, the total filler loading in the composite was increased. At the 25 percent submicron silica level, the filler loading was highest and the physical strength measurements were highest, except for DTS results, which were fairly steady throughout the 5-40 percent level.

Composite Resins↗