Radiographic and histomorphometric analysis of bone healing using autogenous graft associated with platelet-rich plasma obtained by 2 different methods

The aim of this study was to conduct radiographic and histomorphometric analysis of bone healing in the calvaria of rabbits, using an autogenous graft associated with PRP obtained by 2 different methods. Thirty rabbits were divided into control and experimental groups. Lesions were produced in the calvaria and filled with autogenous graft ( control) or autogenous graft and PRP obtained by the Anitua or modified Sonnleitner methods. The animals were humanely killed 15 days after surgery and the calvarias were radiographed. The radiographs were digitized to assess the radiographic density. By histologic images of the lesion, the bone matrix was quantified. There were no significant differences in the radiographic density and the bone matrix area between the groups. The association of PRP with autogenous bone did not improve the healing process, irrespective of the method used early during healing.

Conjugated linoleic acid and cardiac health: Oxidative stress and energetic metabolism in standard and sucrose-rich diets

Studies on conjugated linoleic acid ingestion and its effect on cardiac tissue are necessary for the safe utilization of this compound as supplement for weight loss. Male Wistar 24-rats were divided into four groups (n = 6):(C)given standard chow, water and 0.5 ml saline, twice a week by gavage; (C-CLA)receiving standard chow, water and 0.5 ml of conjugated linoleic acid, twice a week, by gavage; (S)given standard chow, saline by gavage, and 30% sucrose in its drinking water; (S-CLA)receiving standard chow, 30% sucrose in its drinking water and conjugated linoleic acid. After 42 days of treatment S rats had obesity with increased abdominal-circumference, dyslipidemia, oxidative stress and myocardial lower citrate synthase(CS) and higher lactate dehydrogenase(LDH) activities than C. Conjugated linoleic acid had no effects on morphometric parameters in C-CLA, as compared to C, but normalized morphometric parameters comparing S-CLA with S. There was a negative correlation between abdominal adiposity and resting metabolic rate. Conjugated linoleic acid effect, enhancing fasting-VO2/surface area, postprandial-carbohydrate oxidation and serum lipid hydroperoxide resembled to that of the S group. Conjugated linoleic acid induced cardiac oxidative stress in both fed conditions, and triacylglycerol accumulation in S-CLA rats. Conjugated linoleic acid depressed myocardial LDH comparing C-CLA with C, and beta-hydroxyacyl-coenzyme-A dehydrogenase/CS ratio, comparing S-CLA with S. In conclusion, dietary conjugated linoleic acid supplementation for weight loss can have long-term effects on cardiac health. Conjugated linoleic acid, isomers c9, t11 and t10, c12 presented undesirable pro-oxidant effect and induced metabolic changes in cardiac tissue. Nevertheless, despite its effect on abdominal adiposity in sucrose-rich diet condition, conjugated linoleic acid may be disadvantageous because it can lead to oxidative stress and dyslipidemic profile. (c) 2007 Elsevier B.V All rights reserved.

Ag-rich phase precipitation in the Cu-9 mass% Al alloy with Ag additions

The Ag-rich phase precipitation in the Cu-9 mass% Al was studied using differential scanning calorimetry (DSC), X-ray diffractometry (XRD) and scanning electron microscopy (SEM). The results indicated that Ag additions did not interfere on the metastable transitions sequence of the Cu-mass% Al alloy but Ag precipitation disturbs the beta phase formation reaction and the martensitic phase decomposition reaction.

Chronic consumption of fructose rich soft drinks alters tissue lipids of rats

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Microhabitat and plant structure of Batrachospermum (Batrachospermales, Rhodophyta) populations in four streams of São Paulo State, southeastern Brazil

Microhabitat and plant structure of seven Batrachospermum populations (four of Batrachospermum delicatulum (= Sirodotia delicatula), one of Batrachospermum macrosporum and two of the 'Chantransia' stage), including the influence of physical variables (current velocity, depth, irradiance and substratum), were investigated in four streams of São Paulo State, southeastern Brazil. The populations of B. delicatulum and the 'Chantransia' stage occurred under very diverse microhabitat conditions, which probably contributes to their wide spatial and seasonal distribution in Brazilian streams. Results suggest branch reconfiguration as a probable mechanism of adaptation to current velocity based on the occurrence of: (i) B. macrosporum (a large mucilaginous form with presumably little ability for branch reconfiguration) under lower current velocity than B. delicatulum; (ii) only dense plants in populations with high current velocities (> 60 cm s-1), whereas 53-77% of dense plants were seen in populations exposed to lower currents (< 40 cm s-1); (iii) positive correlations of plant length with internode length in populations under low current velocities and negative correlation in a population with high velocity (132 cm s-1); and (iv) negative correlations of current velocity with plant diameter and internode length in a population under high flow. This study, involving mainly dioecious populations, revealed that B. delicatulum displayed higher fertilization rates than B. macrosporum. A complementary explanation for a dioecious species to increase fertilization success was proposed consisting of outcrossing among intermingled male and female adjacent plants within an algal spot.

Microhabitat and morphometric variation of two chaetophoracean (chaetophorales, chlorophyta) species in tropical streams of southeastern Brazil

Two populations of Chaetophora elegans (Roth) C. Agardh and two of Stigeoclonium helveticum Vischer were investigated for microhabitat characteristics and morphological variation in streams of Sao Paulo State, southeastern Brazil. Different patterns of microhabitat distribution were found between species investigated. Populations of C. elegans were distributed under relatively narrow microhabitat conditions (high irradiance, low depth, moderate to high current velocity, rocky substrata and lower values of niche width) and showing little morphometric variation (colony diameter, main axis cell size, and apical branch number). Stigeoclonium helveticum occurred under more diverse microhabitat conditions, revealed by lack of significant difference between sampling units with and without the alga and wider niche width, but also exhibited relatively narrow morphometric variation (plant length, main axis cell and lateral branch cell sizes). The narrow microhabitat conditions and smaller niche width of C. elegans can explain its low abundance (percentage cover) in streams from the area studied as well as in other regions of Sao Paulo State. In contrast, the wider variation of microhabitat conditions and the higher niche widths of S. helveticum suggest that this green alga is able to grow in a high number of stream ecosystems in the region investigated, ranging from undisturbed to highly disturbed habitats. Thus, the results suggest that S. helveticum is a generalist species.

Pressure-induced phase transitions in Zr-rich PbZr1-xTixO3 ceramics

A Raman study of structural changes in the Zr-rich PbZr1-x TixO3 (PZT) system under hydrostatic pressures up to 5.0 GPa is presented. We observe that externally applied pressure induces several phase transitions in PZT ceramics among phases with orthorhombic (Ao), rhombohedral low-temperature (RLT), and rhombohedral high-temperature (RHT) symmetries (all found in PZT at ambient pressure and room temperature). Each of the compositions investigated (0.02 ≤ x ≤ 0.14) exhibits a high-pressure phase with orthorhombic (OI′) symmetry. We further report a detailed study of the pressure dependence of Raman frequencies to elucidate the phase transitions and to provide a set of pressure coefficients for the high-pressure phases.

Reproductive ecology of the freshwater red alga Batrachospermum delicatulum (Batrachospermales, Rhodophyta) in three tropical streams

Batrachospermum delicatulum specimens from three stream segments were analyzed from a tropical region in south-eastern Brazil (20°18′- 20°49′S, 49°13′-49°46′W). Physical and chemical parameters and the spatial placement of thalli were investigated along with the reproductive characteristics of the gametophytic phase. Sequence data of the cox 2-3 spacer region was also utilized to evaluate genetic variation in individuals within and among stream segments. Gametophyte occurred under relatively diverse environmental conditions, whereas thalli abundance was weakly or not correlated to environmental variables within the stream segments. All specimens examined were dioecious. The ratio of male/female plants was relatively low (0.5 to 1.3) and male plants tended to occur as clumps (two or three plants together). High reproductive success was observed, as indicated by the occurrence of 100% fertilized (carposporophytic) female plants. This is similar to previous reports for this and other dioecious species, which is remarkable considering the relatively low proportion of male/female plants. Results support the two hypotheses to explain the high reproductive success in dioecious species. The occurrence of male plants in clumps was evidence for a strict spatial relationship (i.e. male plants located in upstream position of female plants in order to release spermatia, which would be carried by eddies through female plants). In contrast, the occurrence of male and female plants adjacent to each other allowed outcrossing among neighboring plants with intermingled male and female branches, which seemed more applicable to some situations (low turbulence habitats). The cox 2-3 spacer region from the 18 individuals sequenced was 376 bp and the DNA sequence was identical with no base pair substitutions. Likewise, a previous study of another Batrachospermum species showed that the same haplotypes were present in all stream segments from the same drainage basin, even though the stream segments were a considerable distance apart. Short distance dispersal either by small birds or waterway connectivity might explain these findings.

Leucine-rich diet alters the eukaryotic translation initiation factors expression in skeletal muscle of tumour-bearing rats

Background: Cancer-cachexia induces a variety of metabolic disorders on protein turnorver, decreasing protein synthesis and increasing protein degradation. Controversly, insulin, other hormones, and branched-chain amino acids, especially leucine, stimulate protein synthesis and modulate the activity of translation initiation factors involved in protein synthesis. Since the tumour effects are more pronounced when associated with pregnancy, ehancing muscle-wasting proteolysis, in this study, the influence of a leucine-rich diet on the protein synthesis caused by cancer were investigated. Methods: Pregnant rats with or without Walker 256 tumour were distributed into six groups. During 20 days of experiment, three groups were fed with a control diet: C - pregnant control, W - tumour-bearing, and P - pair-fed, which received the same amount of food as ingested by the W group; three other groups of pregnant rats were fed a leucine-rich diet: L - pregnant leucine, WL - tumour-bearing, and PL - pair-fed, which received the same amount of food as ingested by the WL group. Results: The gastrocnemius muscle of WL rats showed increased incorporation of leucine in protein compared to W rats; the leucine-rich diet also prevented the decrease in plasma insulin normally seen in W. The expression of translation initiation factors increased when tumour-bearing rats fed leucine-rich diet, with increase of ∼35% for eIF2α and eIF5, ∼17% for eIF4E and 20% for eIF4G; the expression of protein kinase S6K1 and protein kinase C was also highly enhanced. Conclusion: The results suggest that a leucine-rich diet increased the protein synthesis in skeletal muscle in tumour-bearing rats possibly through the activation of eIF factors and/or the S6kinase pathway. © 2007 Ventrucci et al; licensee BioMed Central Ltd.

Exotic neutron-rich nuclei in a three-body model

We present results for spatial distributions of weakly-bound three-body systems, derived from a universal scaling function that depends on the mass ratio of the particles, as well as on the nature of the subsystems. © 2007 American Institute of Physics.

Avoiding leukocyte contamination and early platelet activation in platelet-rich plasma.

The objective of this study was to describe a new platelet-rich plasma (PRP) protocol with a reduced concentration of leukocytes and intact platelets. We collected 8 mL of venous blood (VB) from marginal ear veins of 10 male New Zealand white rabbits in acid dextrose citrate Vacutainer tubes. Tubes were centrifuged at 302g for 10 minutes. All plasma was collected in plastic tubes to avoid buffy-coat contamination and centrifuged at 2862g for 5 minutes. A 10% calcium chloride activator (10 PRP:2 CaCl2) was added to the lower third of this plasma (PRP), and the PRP gel was obtained. Mean platelet count was 317.7 x 10(3) +/- 39.9/microL in VB and 1344.9 x 10(3) +/- 347.5/microL in PRP. Leukocyte counts were 3.96 x 10(3) +/- 2.01/microL and 0.46 x 10(3) +/- 0.45/microL in VB and PRP, respectively. Mean platelet enrichment was 327.4 +/- 97.8%. All differences were statistically significant (P > .05). This protocol is practical and reproducible, resulting in a high concentration of intact platelets to help tissue repair and low levels of leukocytes.

BMP implant associated with platelet-rich plasma in orbit fracture repair

Purpose: To evaluate a bone morphogenetic protein (BMP) implant with and without platelet-rich plasma (PRP), which is supposed to accelerate fracture consolidation in the orbit fracture treatment. Methods: Thirty-six white rabbits were subjected to orbital fracture and treated in three groups: BMP implant fracture repair (G1), BMP plus PRP implant fracture repair (G2), and fracture and spontaneous repair (G3). The animals were sacrificed at 7, 30, 90, and 180 days after surgery. A radiology evaluation was carried out on the 7th day after the fracture and at the sacrifice moments. After the animals' death, the orbital content material was removed and prepared for morphological and morphometric analysis. Results: Radiology suggested intramembranous and progressive cavitation and ossification without a reduction in implant size and with signs of calcium deposition; these events were confirmed by histological analysis, which showed a lymphomononuclear inflammatory reaction in G1 and G2, more intense 7 days after surgery and reducing after 30 days. Associating PRP with BMP did not accelerate bone induction. Conclusion: BMP implant promotes bone induction, integration at fracture site, scarce inflammatory reaction, and may be a good alternative in orbit fracture reconstruction. The addition of PRP to the BMP plate did not accelerate the resolution, and its use is not necessary. Copyright © Informa Healthcare USA, Inc.

Influence of diltiazem in combination with a sucrose-rich diet on gingival alterations in rats

The aim of this study was to evaluate the influence of diltiazem in combination with a sucrose-rich diet on gingival alterations in rats. One hundred and twenty male Holtzman rats were randomly assigned to 10 groups (n = 12), being 2 control groups treated with saline and 8 test groups treated with diltiazem in daily doses of 5, 25, 50 and 100 mg/kg during 40 or 60 days. Afterwards, the mandibles were removed for macroscopic, histologic and histometric analyses of the buccal gingiva of the mandibular right first molar. No macroscopic characteristic of gingival overgrowth was observed in any of the groups. The microscopic analysis showed characteristics of normality with inflammatory cells only adjacent to the crevicular epithelium in all groups for both periods. The histometric analysis showed significant differences only for the epithelial tissue area in the 40-day period (Kruskal-Wallis; P = 0.032). Comparing the periods, significant differences regarding the connective and epithelial tissue areas were observed only in the group treated with a 25 mg/kg dose (Mann-Whitney; P = 0.004 and P = 0.007, respectively). Oral administration of diltiazem in combination with a sucrose-rich diet did not induce gingival alterations in rats. © 2009 Sociedade Brasileira de Pesquisa Odontológica.