Alterations induced by titanium dioxide nanoparticles (nano-TiO2) in fertilization and embryonic and larval development of the tropical sea urchin Lytechinus variegatus.

The release of nanomaterials into the environment is the cause of an emerging concern. Titanium dioxide nanoparticles (nano-TiO2) among the most produced nanomaterials, has been documented in marine coastal areas posing a threat on marine biota. Sea urchin embryos are recognized as suitable bioindicators in ecological risk assessment and recently for nanomaterials. This study investigated the impact of nano-TiO2 on fertilization, embryonic and larval development of the tropical sea urchin Lytechinus variegatus in a range of concentrations (0.005-5 µg/mL) which includes environmentally relevant ones. The behavior of nano-TiO2 in tropical natural seawater was determined by dynamic light scattering (DLS) and toxicity was evaluated through fertilization and embryotoxicity tests, and morphological/morphometric analyses of sea urchin's larvae. Limited toxicity was recorded for nano-TiO2 in tropical sea urchin embryos and larvae, except for effects at the gastrula stage at 0.005 µg/mL. Large agglomerates of nano-TiO2 (5 µg/mL) were observed adhering onto sea urchin larvae thus probably preventing nanoparticles uptake at the highest concentrations (>0.005 µg/mL). Environmental levels of nano-TiO2 are able to cause toxicity on tropical sea urchin L. variegatus embryos with potential consequences on populations and their ecological role in tropical coastal areas.

Clinical Impact of Surgical Complications in Kidney Transplant Recipients in a Reference Hospital in Salvador, Bahia, Brazil.

BACKGROUND: Renal transplantation is the treatment of choice for patients with stage V chronic kidney disease, which does not have contraindications to the procedure and is more cost-effective than dialysis treatments and provides better survival and quality of life. OBJECTIVE: The objective of this study was to evaluate the incidence of postoperative complications in kidney transplant recipients in a reference hospital. METHODOLOGY: This was a descriptive and retrospective study involving the analysis of patient records during hospitalization and outpatient treatment. We analyzed the demographics, clinical indicators, surgical techniques, and postoperative complications. RESULTS: In the analysis of 147 transplantations, there was a higher incidence of transplantation in female recipients, average age of 37 years with a predominance of cadaveric transplantation. Of all pretransplantation comorbidities, hypertension was the most frequent. The overall incidence of surgical complications was 29.9%, with an incidence of vascular complications of 12.7%, 13.4% of surgical site complications, 8.2% of urologic complications, and 3% of hemorrhagic complications. DISCUSSION: Vascular complications are serious complications and are associated with increased risk of graft loss (relative risk, 8.4), particularly arterial thrombosis. Patients with ureteral anastomosis using Lich-Gregoir technique showed lower urologic complications compared with patients with anastomosis by Leadbetter-Politano technique. CONCLUSION: Surgical complications have different clinical effects, depending on their category. The vascular complications are associated with graft lost.

Armazenamento de sementes de Alfavaca-cravo (Ocimum gratissimum L. ) / Storage of Clove Basil (Ocimum gratissimum L. ) seeds

A espécie Ocimum gratissimum L. é um subarbusto aromático, pertencente à família Lamiaceae, considerado como importante produtor de óleo essencial e largamente utilizado na medicina popular. Devido à escassez de informações sobre a conservação das sementes dessa espécie o presente estudo objetivou analisar a longevidade das sementes submetidas a diferentes condições de armazenamento, por 12 meses, através de avaliações do potencial germinativo e da capacidade de formação de plântulas normais. As sementes foram armazenadas em três tipos de embalagens: sacos de papel, sacos de papel aluminizado, e frascos de vidro, e nas seguintes condições ambientais: balcão de laboratório, geladeira, e câmara fria. Aos 6, 8, 10 e 12 meses de armazenamento foram avaliados os seguintes parâmetros: umidade, porcentagem de germinação, índice de velocidade de germinação e porcentagem de plântulas normais. Durante o período de armazenamento a manutenção da umidade nas sementes foi mantida, bem como a porcentagem de germinação e de plântulas normais em todos os tratamentos avaliados. As sementes armazenadas apresentaram maiores valores de IVG quando comparadas com as recém-colhidas.

The Ocimum gratissimum L. species is an aromatic subshrub that belongs to the Lamiaceae family and is considered as an important producer of essential oil, widely used in folk medicine. Because of the lack of information about the conservation of O. gratissimum seeds, we aimed to evaluate the longevity of the seeds on different storage conditions for 12 months through the germination and seedling formation percentage in this study. The seeds were stored in three types of packages: paper bags (permeable), aluminized paper bags (semipermeable) and glass flasks (impermeable), in the settings of laboratory bench, refrigerator and cold room over the 12 month period. The germination tests were performed on the 6th, 8th, 10th and 12th month, when moisture, germinability, germination velocity index and percentage of normal seedlings were evaluated. During the storage period, moisture, germinability and percentage of normal seedling were kept in each storage condition. The stored seeds showed increased values of GSI compared to the newly- harvested ones.

Vascular calcification: contribution of parathyroid hormone in renal failure.

Hyperphosphatemia is a driving force in the pathogenesis of vascular calcification (VC) and secondary hyperparathyroidism associated with renal failure. To test for the possible contribution of parathyroid hormone (PTH) to cardiovascular calcification, we removed the parathyroid glands from rats but infused synthetic hormone at a supraphysiologic rate. All rats were pair-fed low, normal, or high phosphorus diets and subjected to a sham or 5/6 nephrectomy (remnant kidney). Control rats were given a normal diet and underwent both sham parathyroidectomy and 5/6 nephrectomy. Heart weight/body weight ratios and serum creatinine levels were higher in remnant kidney rats than in the sham-operated rats. Remnant kidney rats on the high phosphorus diet and PTH replacement developed hyperphosphatemia and hypocalcemia along with low bone trabecular volume. Remnant kidney rats on the low phosphorus diet or intact kidney rats on a normal phosphorus diet, each with hormone replacement, developed hypercalcemia. All rats on PTH replacement developed intense aortic medial calcification, and some animals presented coronary calcification. We suggest that high PTH levels induce high bone turnover and medial calcification resembling Mömckeberg's sclerosis independent of uremia. This model may be useful in defining mechanisms underlying VC.

Tijuca National Park: two pioneering restorationist initiatives in Atlantic forest in southeastern Brazil

As a contribution to the environmental history of the Tijuca National Park, we report on two pioneering restorationist initiatives and list its the mammal species now found in this urban park. The Tijuca National Park (TNP), a 3,200 ha urban park covered by secondary tropical forest, is located within Rio de Janeiro, in southeastern Brazil. The two restorationist initiatives were a pioneer tropical forest restoration project in the nineteenth century and a fauna management project in the 70' s. The mammal list presented here was based on specimens in the Museu Nacional do Rio de Janeiro and on publications. The mammal community of TNP is composed of 49 species, of which 11 are on regional red lists, and four are on the 2003 IUCN Red List of Threatened Species. Occurrence of these threatened species and the park history itself made the TNP a priority site for studying conservation, management, and monitoring. Besides maintaining fauna and flora (including threatened species) diversity, the park benefits the population of Rio de Janeiro by providing water, green areas, and recreational and touristic opportunities.

Estudos sobre monitoramento, regeneração florestal e manejo de fauna devem usar a história ambiental como referência para compreender o passado da área de estudo e para monitorar os resultados desses estudos. Para criar a base da história ambiental para o Parque Nacional da Tijuca, relatamos duas iniciativas clássicas de restauração e a lista das espécies de mamíferos que ocorrem atualmente neste parque urbano, que depende dessas iniciativas. O Parque Nacional da Tijuca (PNT) é um parque urbano de 3.200 ha coberto por floresta tropical secundária e cercado pela cidade do Rio de Janeiro, no Sudeste do Brasil. No PNT, ocorreram duas iniciativas clássicas de restauração: a pioneira restauração da floresta tropical no século XIX e o projeto de manejo da fauna nos anos 70. A lista de mamíferos foi baseada em publicações e nos espécimens depositados no Museu Nacional do Rio de Janeiro. A comunidade de mamíferos do PNT é composta por 49 espécies, sendo 11 incluídas nas listas vermelhas regionais e quatro espécies na Lista Vermelha de Espécies Ameaçadas da IUCN de 2003. A ocorrência dessas espécies ameaçadas e a história do parque tornaram o Parque Nacional da Tijuca uma área de estudo prioritária para monitoramento, conservação e manejo. Além do PNT ser um parque urbano importante para a manutenção da diversidade da fauna e da flora, incluindo as espécies ameaçadas, também melhora a qualidade de vida da população da cidade do Rio de Janeiro, fornecendo áreas verdes, recreação, turismo e abastecimento de água. Concluindo, enfatizamos a grande importância da história ambiental no Parque Nacional da Tijuca para a composição atual da comunidade de mamíferos.

Osteoporosis in hemodialysis patients revisited by bone histomorphometry: a new insight into an old problem.

Osteoporosis in hemodialysis patients is associated with high morbidity and mortality and, although extensively studied by noninvasive methods, has never been assessed through bone biopsy. The aim of this study was to use histomorphometry to evaluate osteoporosis and identify factors related to its development in hemodialysis patients. We conducted a cross-sectional study involving 98 patients (35 women and 63 men; mean age: 48.4 +/- 13 years) on hemodialysis for 36.9 +/- 24.7 months. Patients were submitted to transiliac bone biopsy with double tetracycline labeling. The bone metabolism factors ionized calcium, phosphorus, bone alkaline phosphatase, deoxypyridinoline, intact parathyroid hormone, and 25(OH) vitamin D were evaluated, as were the bone remodeling cytokines osteoprotegerin (OPG), soluble receptor-activator of NF-kappabeta ligand (sRANKL) and tumor necrosis factor-alpha (TNF)alpha. Osteoporosis was defined as trabecular bone volume (BV/TV) greater than 1 s.d. below normal (men <17.4%; women <14.7%). Forty-five patients (46%) presented osteoporosis, which was correlated with white race. We found BV/TV to correlate with age, OPG/sRANKL ratio, TNFalpha levels, and length of amenorrhea. In multiple regression analysis adjusted for sex and age, length of amenorrhea, white race, and OPG/sRANKL ratio were independent determinants of BV/TV. Histomorphometric analysis demonstrated that osteoporotic patients presented normal eroded surface and low bone formation rate (BFR/BS). Osteoporosis is prevalent in hemodialysis patients. Low BFR/BS could be involved in its development, even when bone resorption is normal. Cytokines may also play a role as may traditional risk factors such as advanced age, hypogonadism, and white race.

Tijuca National Park: two pioneering restorationist initiatives in Atlantic forest in southeastern Brazil.

As a contribution to the environmental history of the Tijuca National Park, we report on two pioneering restorationist initiatives and list its the mammal species now found in this urban park. The Tijuca National Park (TNP), a 3,200 ha urban park covered by secondary tropical forest, is located within Rio de Janeiro, in southeastern Brazil. The two restorationist initiatives were a pioneer tropical forest restoration project in the nineteenth century and a fauna management project in the 70' s. The mammal list presented here was based on specimens in the Museu Nacional do Rio de Janeiro and on publications. The mammal community of TNP is composed of 49 species, of which 11 are on regional red lists, and four are on the 2003 IUCN Red List of Threatened Species. Occurrence of these threatened species and the park history itself made the TNP a priority site for studying conservation, management, and monitoring. Besides maintaining fauna and flora (including threatened species) diversity, the park benefits the population of Rio de Janeiro by providing water, green areas, and recreational and touristic opportunities.