César Serra Bonifácio Costa

Endothelin-1 plasma levels and hypertension in cyclosporine-treated renal transplant patients

Abstract:  Experimental models suggest that endothelin‐1 (ET‐1) has a significant role in the pathogenesis of cyclosporin A (CyA)‐induced hypertension. However, its serum levels evaluated in different studies, including patients who received solid organ transplants, exhibited controversial results. Our study population consisted of 43 renal transplant patients: 33 were taking CyA as a component of their immunosuppressive regimen (CyA group) and 10 that were not taking CyA (control group). Baseline laboratory data, blood pressure and ET‐1 levels were taken at baseline and 3 and 4 h after the ingestion of CyA. In the control group samples were collected in the corresponding periods of time. Blood pressure was significantly higher in the CyA group (mean blood pressure: 101.2 ± 9.5 vs. 91.1 ± 10.7 mmHg; p < 0.001), who also presented higher serum creatinine (1.2 ± 0.28 vs. 0.97 ± 0.13 mg/dL; p < 0.001) and ET‐1 levels. In the CyA group an ET‐1 peak was evident by the third hour after CyA ingestion that showed its maximum concentration after 1–2 h; the control group exhibited significantly lower levels of ET‐1 (p = 0.044). ET‐1 levels compared between patients with and without hypertension showed a non‐statistically significant difference (1.54 ± 0.76 vs. 1.27 ± 0.62 ng/mL; p = 0.27, respectively). In conclusion, in the present study chronic CyA ingestion was associated with higher blood pressure and plasma ET‐1 levels.

Vertical distribution and resource allocation of Ruppia maritima L. in a southern Brazilian estuary

Abstract The vertical distribution and resource allocation of Ruppia maritima L. were studied in the Patos Lagoon estuary, Brazil. Light intensities, water transparency and water depths at the plant site were measured daily during the growth period from August 1980 to January 1981. Plant samples from 4 water depths (0.25–0.70 m below mean low water) were collected during the growth and reproductive peak of the population in January 1981. The upper limit of the plants was at water depths (0.25 m) where aerial exposures of the plants were no longer than 50% of the total time during the growth period. Highest vegetative shoot numbers and biomass were found at 0.40-m water depth. Reduced vegetative growth below 0.55 m appeared to be related to light intensity. Based on the average extinction coefficient and photosynthetically active light below the surface during the flowering period, optimal growth (vegetative and flowering) (0.40 m) and the lower growth limit of Ruppia (0.70 m) occurred at 4860–5760and 1660–1970 lux, respectively. The high proportion (90%) of resource allocations into flowering shoots and maximum number of flowers and fruits at lowest depth, as well as their absence at 0.55 m water depth, suggests the existence different strategies in intertidal and subtidal habitats.

Serum Leptin, Insulin Resistance, and Body Fat After Renal Transplantation

OBJECTIVE Our objective was to evaluate serum levels of leptin, body mass index (BMI), body-fat percentage (BF%), and insulin resistance in the first year after renal transplantation. DESIGN This study involved a prospective, observational cohort. SETTING The setting was a transplant unit of a university teaching hospital in Porto Alegre, Brazil. PATIENTS Thirty-two patients who underwent renal transplantation were prospectively followed for 1 year. A control group of 19 healthy individuals, matched by sex, age, and BMI, was included in the study. METHODS Body mass index and BF% were measured according to anthropometric measures, serum leptin was measured by radioimmunoassay, and the homeostasis model assessment (HOMA) was used as an index of insulin resistance. Anthropometric measures and biochemical markers were evaluated prospectively, starting at transplant time and then every 3 months for up to 1 year. RESULTS Leptin levels were increased before transplantation, and decreased significantly in the first year (median, 11.9 [interquartile range, 9.2 to 25.2] to 9.3 [4.9 to 16.4] ng/mL; P < .001). The HOMA values presented a similar pattern, decreasing from 2.4 +/- 1.5 (mean +/- SD) before transplantation, to 1.5 +/- 1.1 (P = .001) at 3 months after transplantation, but increasing to 2.0 +/- 1.7 at month 12 after transplantation (P = not significant). The BMI and BF% increased significantly in the first year after transplantation (23.3 +/- 2.7 kg/m(2) vs. 24.4 +/- 2.7 kg/m(2), P = .001, and 23.71% +/- 7.79% vs. 25.63% +/- 7.68%, P = .002, respectively). According to multivariate regression analysis, HOMA levels and BF% independently predicted leptin levels after transplantation. CONCLUSIONS We found that leptin serum levels decreased significantly over the first posttransplant year. However, the effect of transplantation on insulin resistance appears to be transitory, and BF% also increases steadily in this period. The beneficial profile of leptin levels is counterbalanced by the detrimental effects of insulin resistance and BF% that may be related to the elevated cardiovascular risk observed after transplantation.

Composição florística das formações vegetais sobre uma turfeira topotrófica da planície costeira do Rio Grande do Sul, Brasil

Turfeiras topotroficas caracterizam-se como corpos de aguas rasas, permanente ou periodicamente alagados por agua do lencol freatico, percolada atraves do solo inorgânico das terras altas adjacentes a depressao central da turfeira. Possuem solos orgânicos e a cobertura vegetal e dominanda por fanerogamas aquaticas emergentes. Este estudo visou o levantamento da diversidade especifica e caracterizacao das principais formacoes vegetais ao longo de duas transeccoes de 200m em uma turfeira topotrofica na localidade de Domingos Petrolini (Rio Grande, RS). Em marco/1998, o total de 48 especies vegetais (30 familias) foram encontradas nas 40 parcelas de 5m × 2m observadas nas duas transeccoes efetuadas. Cerca de 56% das especies eram plantas aquaticas herbaceas (submersas, flutuantes ou emergentes) e apenas 10% arbustos ou arvores. Sete especies dominaram a cobertura vegetal (Eupatorium tremulum, Eryngium pandanifolium, Blechnum brasiliense, Rhynchospora sp., Xyris jupicai, Utricularia gibba e Cladium jamaicense). Quatro formacoes vegetais tipicamente distribuidas em relacao a topografia e a distância do lencol freatico foram caracterizadas: (1) banhados do capim-navalha Cladium jamaicense, drenados apenas no verao, ocupam a depressao central da turfeira (DCT); (2) planos medios de Gravatas/Caraguatas (Eryngium pandanifolium) associados a samambaia Blechnum brasiliense (+0,5 a +1,5m da DCT); (3) bosques marginais de arbustos palustres (+1 a +3m da DCT) sao dominados por Eupatorium tremulum; e (4) campos de turfa recobertos por ciperaceas de pequeno porte, gramas boiadeiras e botoes-de-ouro (Xyris jupicai) ocupam a borda do afloramento da turfa (+3 a +4m da DCT).

Leptin, Insulin Resistance, and Metabolic Changes 5 Years After Renal Transplantation

OBJECTIVE To evaluate leptin, insulin resistance (IR), and changes in body composition and lipid profile within 5 years after renal transplantation. DESIGN Longitudinal study. SETTING Hospital de Clínicas de Porto Alegre/RS, Brazil. SUBJECTS Thirty-two renal transplant recipients were followed up for 5 years after transplantation. METHODS Data were collected at transplantation time (T₁) and after 3 months (T₂), 1 year (T₃), and 5 years (T₄). Leptin serum levels, IR assessed by homeostasis model assessment (HOMA) index, lipid profile, and anthropometric measurements were analyzed. Data were compared with a control group at baseline. RESULTS At T₁, pretransplant patients had leptin levels (ng/mL) (11.9 [9.2 to 25.2]) higher than the control group (7.7 [5.2 to 9.9]; P < .0001). After transplantation, levels decreased at T₂ and T₃, but increased at T₄ to values similar to those seen at T₁ (T₄: 9.2 [5.7 to 21]; P = 1). HOMA also decreased at T₂, but increased at T₄ to identical levels (T₁: 2.1 [1.63 to 2.23], T₄: 2.1 [1.6 to 2.85]; P = 1). No significant changes in body fat percentage (BF%) were observed; however, the arm muscle circumference increased significantly at T₄ (P < .0001). At T₂, total cholesterol, triglycerides, and low-density lipoprotein cholesterol increased, whereas at T₄, lipid profile moved toward T₁ levels. By linear regression analysis, gender, BF%, and HOMA were independent predictors of leptin levels. A trend toward higher body mass index was observed in woman who also presented higher leptin and lower HOMA levels. CONCLUSION Leptin levels and HOMA decrease in the immediate posttransplant period and remain reduced for at least 1 year. Five years post transplantation, leptin, IR, BF%, and lipids have a profile similar to those in the pretransplant period. This metabolic profile is possibly associated with the elevated incidence of cardiovascular diseases observed in the late posttransplant period.

Fatty acids composition in seeds of the South American glasswort Sarcocornia ambigua

Sarcocornia ambigua (Michx.) M.A. Alonso & M.B. Crespo is the most widely distributed species of the perennial genus of glasswort in South America, and it shows great biotechnological potential as a salt-water irrigated crop. Qualitative and quantitative compositions of fatty acids were determined in the seeds of S. ambigua that were cultivated in southern Brazil. Hexane extraction of the seed oil from S. ambigua yielded 13% of total lipids. The GC-FID (Gas Chromatography Flame Ionization Detector) analysis of the hexane extracts showed five prominent peaks for the seed oil: 42.9 wt.% linoleic-ω6 acid (18:2), 20.4 wt.% palmitic acid (16:0), 18.5 wt.% oleic acid (18:1), 4.5 wt.% stearic acid (18:0) and 4.0 wt.% linolenic-ω3 acid (18:3). The sum of the saturated palmitic and stearic acids (24.8%) in S. ambigua seed oil exceeded values cited for commercial oils use, as well as the seed oil from the cultivated annual glasswort Salicornia bigelovii. No undesirable fatty acid components were found in S. ambigua seed oil, and it could be recommended for animal consumption or biofuel production.

Natural and anthropogenic effects on salt marsh over five decades in the patos lagoon (Southern Brazil)

and Cesar Serra Bonifacio Costa Instituto de Oceanografia – FURG (Caixa Postal 474, 96201-900 Rio Grande, RS, Brasil) *julianomarangoni@pop.com.br Salt marshes constitute major coastal ecosystems in the intertidal zones in temperate regions covered with halophytic plants. In southern Brazil, salt marshes occupy 70 km

Crab Bioturbation and Herbivory May Account for Variability in Carbon Sequestration and Stocks in South West Atlantic Salt Marshes

Coastal vegetation plays an important role for climate change mitigation. Compared with terrestrial ecosystems, coastal vegetation shows higher rates of atmospheric CO2 uptake and a more efficient retention of carbon (C) in sediments. Salt marshes present the highest values as C binders, although a global estimation of these values is still pending due to regional gaps in the records predominantly from the southern hemisphere. There are no clear patterns or dominant processes with enough evidence to account for the observed variability, suggesting that context dependent processes are likely greatest influencers on C storage. Salt marshes in the South West Atlantic (SWA) coast are densely populated by the intertidal burrowing and herbivore crab Neohelice (=Chasmagnathus) granulata. Many ecological processes related to C transformation occurring in these salt marshes are influenced by crab activities, either through bioturbation or via herbivory. We hypothesize that N. granulata could have a significant role in the capacity of SWA salt marshes to bind C. Reduction of plant biomass, increased aerobic decomposition in the sediment and facilitation of erosion are some of the multiple effects exerted by N. granulata that can directly and indirectly modify the capacity of salt marshes to bind C. Here, we compiled information available regarding C sequestration and accumulation in SWA coastal salt marshes and propose a hypothetical model including the mechanisms mediated by N. granulata that interfere the transformation paths of C in salt marshes. The data suggest that mechanisms that are top-down regulated, negatively affect C accumulation in the form of aboveground biomass especially in salt marshes dominated by Spartina alterniflora. While, mechanisms mediated by bioturbation can negatively (increasing oxygenation and thus facilitating aerobic degradation) affect as well as positively (increasing retention of macrodetritus) affect the accumulation of C, the latter being of greater magnitude in Spartina densiflora salt marshes.

Extraction and characterization of lipids from Sarcocornia ambigua meal: a halophyte biomass produced with shrimp farm effluent irrigation.

Sarcocornia ambigua is a perennial glasswort, native of South America and a potential new seed-oil crop and forage for direct irrigation with salt water. Small seeds develop inside fertile segments of its cylindrical leafless shoots and, at the harvest, seeds are typically mixed with remnant cellulose material difficult to separate. This work evaluated different extraction methods and the composition of total esterified fatty acids in a meal of ground fertile shoots of S. ambigua, seeking for an alternative primary matter and larger yield of total lipids. The highest lipid yield was obtained with a chloroform:methanol mixture (2:1)(v/v) (5.2% of dry weight). The most abundant polyunsaturated fatty acids in the meal were linoleic acid (C18:2; 21.4%) and oleic acid (C18:1; 18.3%). Fifty six percent of the lipids in S. ambigua meal were saturated and palmitic acid (C16:0) was the main fraction (19.8%). Long-chain fatty acids (≥ C20) represented 29.5% of the lipids. Most abundant long-chain fatty acids were behenic acid (C22:0; 7.1%), lignoceric acid (C24:0; 5.3%) and montanic acid (C28:0; 4.0%). The percentage of saturated lipids in S. ambigua meal was higher than that of vegetable oils with a MUFA nutritional profile and some of these lipids have known bioactive properties.

SURVIVAL AND GROWTH OF THE DOMINANT SALT MARSH GRASS SPARTINA ALTERNIFLORA IN AN OIL INDUSTRY SALINE WASTEWATER

Saline oil produced water (PW) is the largest wastewater stream in the oil exploration and production processes. Although eventual disposal of PW into shallow coastal waters occurs nearby coastal wetlands, no studies regarding its toxicity to higher plants were found in our literature review. To fill this knowledge gap and evaluate the potential use of this halophyte for PW phytoremediation the salt marsh grass Spartina alterniflora was grown in five PW concentrations and no PW treatment control for seven weeks. The oil & grease, NaCl, and ammonium (N-NH4+) concentrations in the PW were 120 mg L−1, 30 g L−1, and 381 mg L−1, respectively. Plants grown in 30% PW and 10% PW achieved survival rates (75%) significantly higher than plants grown in 100% PW (35% survival). LT50 of S. alterniflora to raw PW with 120 mg L−1 of oil & grease (100% PW) was estimated at 30 days. Root and sprout biomass were significantly stimulated by PW; plants grown in 10% to 50% PW concentrations were 70–300% more productive than those in control, 80% PW and 100% PW, respectively. No significant inhibitory effects on survival or growth were detected for concentrations of PW less than 80% when compared to control. Our results pointed out that S. alterniflora grows in saline oil PW and its potential use to phytoremediate this effluent should be evaluated.