A classification system for large reservoirs of the contiguous United States.

Degradation of reservoir fish habitat has become a serious concern. Habitat issues-such as sedimentation, excessive nutrient loadings, and lack of submerged structure-may emerge and worsen over time and are accompanied by undesirable shifts in the fish community and fisheries. To prioritize habitat rehabilitation efforts in reservoirs, we developed a classification system for large reservoirs in the contiguous U.S. We used a four-step classification approach based on over 50 variables descriptive of habitat impairment in a sample of almost 1300 reservoirs. To account for the broad geographic heterogeneity in climate and landscape, reservoirs were assigned to a spatial framework relevant to aquatic resources, selected based on how well it recognized regional differences in fish habitat. To account for differences among reservoirs within geographical regions, we used cluster analysis to identify classes of reservoirs with similar characteristics. Classes were compared regarding habitat impairment, the fish community, the recreational fishery, and other variables from an external dataset to seek support for the classification system. A method for classifying new reservoirs not included in the original sample was also developed. The resulting classification system identified nine geographical regions distributed throughout the contiguous U.S. and 24 reservoir classes within the nine regions. The system can serve as the framework for a reservoir assessment mechanism. Our approach may be applicable elsewhere a broad-scale dataset is not available and needs to be obtained quickly and inexpensively, whether in regards to fish habitat or other environmental information needs.

Monitoring fish distributions along electrofishing segments.

Electrofishing is widely used to monitor fish species composition and relative abundance in streams and lakes. According to standard protocols, multiple segments are selected in a body of water to monitor population relative abundance as the ratio of total catch to total sampling effort. The standard protocol provides an assessment of fish distribution at a macrohabitat scale among segments, but not within segments. An ancillary protocol was developed for assessing fish distribution at a finer scale within electrofishing segments. The ancillary protocol was used to estimate spacing, dispersion, and association of two species along shore segments in two local reservoirs. The added information provided by the ancillary protocol may be useful for assessing fish distribution relative to fish of the same species, to fish of different species, and to environmental or habitat characteristics.

Effects of smallmouth buffalo, Ictiobus bubalus biomass on water transparency, nutrients, and productivity in shallow experimental ponds.

The smallmouth buffalo Ictiobus bubalus is a native benthivore to floodplain lakes in the Yazoo River Basin, USA. Based on evidence from other benthivorous fish studies we hypothesized high biomasses of I. bubalus contribute to poor water quality conditions. We tested this hypothesis in shallow (<1.5 m) 0.05 ha earthen ponds at three stocking biomasses over a 10-week period during the summer of 2012. The most notable results from the permutational multivariate analysis of variance suggest I. bubalus at high and moderate biomasses significantly (p < 0.05) enhanced turbidity and suspended solid levels while decreasing Secchi depth. Our results suggest that effects of I. bubalus on water clarity may have considerable ecological implications in natural habitats such as shallow floodplain lakes.

Orthotopic liver transplantation without venovenous bypass: 125 cases from a single center.

AIM: This study analyzed a 10-year single-center experience in orthotopic liver transplantation (OLT) without venovenous bypass (VVB). METHODS: We retrospectively analysed a nonrandomized series (1999-2008) of 125 adult OLT patients without VVB. RESULTS: The main causes of liver failure were viral hepatitis (n = 39), alcoholic liver disease (n = 22), and liver cancer (n = 17). One-year survival was 76.4%. The most common postoperative complications were bile duct stenosis (n = 12), postoperative bleeding (n = 8), hepatic artery thrombosis (n = 7), and primary liver failure (n = 6). Twelve patients required hemodialysis and four underwent retransplantations of the liver. Fourteen patients died before postoperative day 30(th). Univariate analysis showed significant differences between patients who did and did not survive 30 days among donor death diagnoses (P = .05), red blood cell units transfused (P = .03), aspartate aminotranferase on the first postoperative day (P = .002), ABO type (P = .04), time of orotracheal intubation (P = .001), hemodialysis (P = .001), and period of postoperative vasoactive drug use (P = .006). The total length of orotracheal tube intubation showed a significant independent association with mortality before 30 days (P < .001). CONCLUSION: OLT without VVB can be safely performed even in severe cases of chronic liver failure.

Alteraciones del índice de masa corporal y peroxidación lipídica en individuos adultos con síndrome de Down / Body mass index changes and lipid peroxidation in adults with Down’s syndrome

Introducción y objetivo: La trisomía 21 o síndrome de Down (SD) es la causa más frecuente de deficiencia mental de origen cromosómico. En los pacientes afectados de SD, la obesidad es un problema de salud pública. La obesidad es un estado prooxidante, asociado con peroxidación lipídica y alteración de mecanismos antioxidantes. El efecto de dosis génica en SD se ha relacionado con estrés oxidativo. El objetivo de este estudio fue determinar el estado de peroxidación lipídica y alteraciones del índice de masa corporal (IMC) en adultos con SD. Pacientes y método: Se realizó un estudio prospectivo y transversal, en 50 adultos (31,0 ± 6,3 años) citogenéticamente normales (CN) y 29 adultos con SD (28,0 ± 8,7 años), seleccionados aleatoriamente. Se cuantificaron concentraciones séricas de malondialdehído (MDA) mediante derivados de ácido tiobarbitúrico. Asimismo, se determino el IMC en adultos con SD. El análisis estadístico requirió SPSS 15, con un intervalo de confianza del 95%, p < 0,05. Resultados: Los adultos con SD presentaron concentraciones elevadas de MDA (0,9 ± 0,7 Nmol/ml; p < 0,009) respecto al grupo de adultos CN (0,5 ± 0,4 Nmol/ml). Se observó anormalidad del IMC en el 72,4% (n = 21) de los adultos con SD. Además, se apreciaron concentraciones elevadas de MDA (1,3 ± 1,0 Nmol/ml) en adultos con SD y sobrepeso (IMC de 27,5 ± 1,3 kg/m2), y se observó una disminución no significativa en adultos obesos con SD. Conclusión: Aunque se ha reportado una reducción de enzimas antioxidantes en adultos sin SD gravemente obesos, el efecto de dosis génica podría contribuir a reducir peroxidación lipídica en adultos con SD obesos, sin representar un factor protector de sus consecuencias patológicas (AU)

Introduction and objective: Trisomy 21 or Down’s syndrome (DS) is the most common cause of mental retardation of chromosomal origin, in which obesity is a public health problem. Obesity is a pro-oxidant state associated with lipid peroxidation and alterations of antioxidant mechanisms. The effect of gene dosage has been linked to oxidative stress in DS. The objective of this study was to determine the status of lipid peroxidation and changes in body mass index (BMI) in adults with DS. Patients and method: A prospective and cross-sectional study was conducted on 50 adult subjects (31.0 ± 6.3 years) with normal karyotype (NK) and 29 adults with DS (28.0 ± 8.7 years), randomly selected. Results: The serum levels of malondialdehyde (MDA) were analysed by thiobarbituric acid derivatives. The BMI was determined in adults with DS. The data were analysed using the SPSS 15 statistical program, using a 95% confidence interval (CI), P<.05. Adults with DS showed high concentrations of MDA (0.9 ± 0.7 nmol / ml, P<.009) compared to adult NK group (0.5 ± 0.4 nmol / ml). Abnormality was observed in 72.4% of BMI (n = 21) of adults with DS. Elevated concentrations of MDA (1.3 ± 1.0 nmol / ml) were seen in adults with DS and overweight (BMI = 27.5 ± 1.3), showing no significant decrease in obese adults with DS. Conclusion: Although a reduction of antioxidant enzymes in severely obese adults without DS has been reported, the effect of gene dosage may be a contributing factor in reducing lipid peroxidation in obese adults with DS, without being a protective factor of its pathological consequences (AU)

Diversity in migratory patterns among Neotropical fishes in a highly regulated river basin.

Migratory behaviour of selected fish species is described in the Paraná River, Brazil-Argentina-Paraguay, to search for patterns relevant to tropical regulated river systems. In a 10 year mark-recapture study, spanning a 1425 km section of the river, 32 867 fishes composed of 18 species were released and 1083 fishes were recaptured. The fishes recaptured were at liberty an average 166 days (maximum 1548 days) and travelled an average 35 km (range 0-625 km). Cluster analysis applied to variables descriptive of movement behaviour identified four general movement patterns. Cluster 1 included species that moved long distances (mean 164 km) upstream (54%) and downstream (40%) the mainstem river and showed high incidence (27%) of passage through dams; cluster 2 also exhibited high rate of movement along the mainstem (49% upstream, 13% downstream), but moved small distances (mean 10 km); cluster 3 included the most fishes moving laterally into tributaries (45%) or not moving at all (25%), but little downstream movement (8%); fishes in cluster 4 exhibited little upstream movement (13%) and farthest downstream movements (mean 41 km). Whereas species could be numerically clustered with statistical models, a species ordination showed ample spread, suggesting that species exhibit diverse movement patterns that cannot be easily classified into just a few classes. The cluster and ordination procedures also showed that adults and juveniles of the same species exhibit similar movement patterns. Conventional concepts about Neotropical migratory fishes portray them as travelling long distances upstream. The present results broaden these concepts suggesting that migratory movements are more diverse, could be long, short or at times absent, upriver, downriver or lateral, and the diversity of movements can vary within and among species. The intense lateral migrations exhibited by a diversity of species, especially to and from large tributaries (above reservoirs) and reservoir tributaries, illustrate the importance of these habitats for the fish species life cycle. Considering that the Paraná River is highly impounded, special attention should be given to the few remaining low-impact habitats as they continue to be targets of hydropower development that will probably intensify the effects on migratory fish stocks.

Orthotopic liver transplantation without venovenous bypass using the conventional and piggyback techniques.

INTRODUCTION: Orthotopic liver transplantation is a widely used procedure for the treatment of irreversible liver diseases for which there is no possibility of medical treatment. When this procedure is performed by the conventional technique, the retrohepatic vena cava is removed along with the native liver. The inferior vena cava (IVC) remains clamped until the revascularization of the graft, and in this period there is a reduction in the venous return, which may induce a fall by up to 50% in the cardiac output with hemodynamic instability and a fall in renal perfusion pressure. The use of a portal-femoral-axillary venovenous bypass system, in which the blood from the femoral and portal veins returns to the heart via the axillary vein propelled by a centrifugal pump, is intended to minimize the effects of the IVC clamping. In the piggyback (PB) technique, the native liver is removed and the IVC of the recipient is preserved and only partially clamped. We have employed both techniques without the use of venovenous bypass for 10 years. The objective of this study was to compare the results obtained from the use of the two techniques. PATIENTS AND METHODS: A retrospective analysis was performed of 195 patients transplanted between 1999 and 2008: 125 by the conventional technique and 70, the PB technique. The intraoperative parameters were analyzed (surgical time, ischemia time, use of blood products, and diuresis), as well as intensive care support (duration of stay in intensive care unit and use of vasoactive drugs), period of intubation, length of hospital stay, renal function, graft function, postoperative complications, retransplantation, and patient survival. RESULTS: The PB group showed a reduction in surgical time, warm ischemia time, the use of packed red blood cells concentrates, and fresh frozen plasma, as well as mortality at 30 days (P<.05). There were no differences in relation to cold ischemia time, intraoperative diuresis; length of stay and use of vasoactive drugs in the intensive care unit; the period of intubation; the duration of hospital stay; the renal function; the graft function; the need for reoperation; the incidence of sepsis, biliary complications, vascular complications; need for retransplantation; and 1-year mortality. The cumulative survival rate at 1 year was significantly better among the PB patients. CONCLUSION: Orthotopic liver transplantation can be performed without venovenous bypass with good results, using either the conventional technique or the PB technique. Provided that there is no technical contraindication and a long ischemia period is not foreseen, the PB technique should be the technique of choice.

Effects of partial liver ischemia followed by global liver reperfusion on the remote tissue expression of nitric oxide synthase: lungs and kidneys.

Hepatic ischemia followed by reperfusion (IR) results in mild to severe remote organ injury. Oxidative stress and nitric oxide (NO) seem to be involved in the IR injury. Our aim was to investigate the effects of liver I/R on hepatic function and lipid peroxidation, leukocyte infiltration and NO synthase (NOS) immunostaining in the lung and the kidney. We randomized 24 male Wistar rats into 3 groups: 1) control; 2) 60 minutes of partial (70%) liver I and 2 hours of global liver R; and 3) 60 minutes of partial (70%) liver I and 6 hours of global liver R. Groups 2 and 3 showed significant increases in plasma alanine and aspartate aminotransferase levels and in tissue malondialdehyde and myeloperoxidase contents. In the kidney, positive endothelial NOS (eNOS) staining was significantly decreased in group 3 compared with group 1. However, staining for inducible NOS (iNOS) and neuronal NOS (nNOS) did not differ among the groups. In the lung, the staining for eNOS and iNOS did not show significant differences among the groups; no positive nNOS staining was observed in any group. These results suggested that partial liver I followed by global liver R induced liver, kidney, and lung injuries characterized by neutrophil sequestration and increased oxidative stress. In addition, we supposed that the reduced NO formation via eNOS may be implicated in the moderate impairment of renal function, observed by others at 24 hours after liver I/R.

Survival on waiting list for liver transplantation before and after introduction of the model for end-stage liver disease score.

BACKGROUND: Since July 2006, the Model for End-stage Liver Disease (MELD) score has served as the national basis for allocation of donor livers for transplantation in Brazil. Patients with higher MELD scores receive greater priority for allocation regardless of the time on the waiting list. PURPOSE: To investigate the impact of MELD score implementation on the survival of waiting list patients. METHODS: A retrospective study of patients registered at the national Organ Procurement Organization (OPO) for the liver transplantation waiting list between January 2004 and June 2006 (pre-MELD) and between July 2006 and December 2008 (post-MELD). RESULTS: We included listed patients awaiting liver transplantation in the pre-MELD era (n = 250, 48.4%) and in the post-MELD era (n = 266, 51.6%). The times awaiting transplant prior to and after the MELD system were 487.2 +/- 384.8 days and 183.9 +/- 157.2 days, respectively. Prior to the MELD score, waiting list survivals were greater when compared to rates in the current system. Early posttransplant patient survival rates were significantly reduced in the post-MELD era (83.4%) compared to the period before MELD implementation (93.2%). CONCLUSIONS: MELD score provides a transparent, objective system to drive allocation policy; however, it presents several important limitations. Constant need of changes and reevaluation are needed as an evolutionary process. Future changes in the present system may be addressed by adjusting the MELD system.

Deficiencia de vitamina A y estado nutricional en pacientes con Síndrome de Down / Vitamin A deficiency and nutritional status in patients with Down's syndrome

Introducción: La deficiencia de vitamina A (DVA) constituye un problema de salud pública a nivel mundial. Estudios epidemiológicos de prevalencia de DVA se han realizado en individuos con carga cromosómica y potencial genético acorde con la población general; no obstante, son escasos los estudios en pacientes con síndrome de Down (SD). El objetivo fue determinar la prevalencia de DVA y estado nutricional en pacientes con SD. Métodos: Se realizó un estudio prospectivo y transversal, en 50 controles (10,4±3,7 años) citogenéticamente normales (CN) y 38 pacientes con SD (8,2±4,1 años), seleccionados aleatoriamente. Se determinó retinol sérico por HPLC según el método de Bieri, utilizando valores de referencia internacional que definen DVA <20μg/dl. Se aplicó el programa SAS/STAT para el análisis estadístico. Resultados: La prevalencia de DVA en pacientes con SD fue 18,4% y en controles CN 4% (OR: 5,64; IC 95%=1,10–28,93; p=0,03). Los niños con SD entre 2–6 años mostraron una reducción significativa de los valores de retinol sérico (p=<0,05). La talla y el peso en pacientes con SD se observó significativamente por debajo de individuos CN (p=<0,001). Conclusión: La alta prevalencia de DVA en individuos con SD debe ser considerada un problema de salud pública. De este modo, la trisomía del cromosoma 21 constituye un factor de riesgo asociado a DVA (AU)

Introduction: Vitamin A deficiency (VAD) is a worldwide public health problem. Epidemiological studies of VAD prevalence have been conducted in individuals with chromosome load and genetic potential compared with the general population; however, there are few studies in patients with Down's syndrome (DS). The objective of this study was to determine the prevalence of VAD and analyse nutritional status in patients with DS. Methods: A prospective and cross-sectional study was performed, with 50 karyotypically normal (KN) individuals (10.4±3.7 years old) and 38 randomly selected patients with DS (8.2±4.1 years old). Serum retinol was determined by HPLC using the Bieri method, with an international reference standard to define VAD (serum retinol <20μg/dL). The data were analysed using the SAS/STAT statistical program. Results: The prevalence of VAD was 18.4% in individuals with DS and 4% in KN individuals (OR: 5.42; 95% CI=0.93–40.64; p=0.02). Children with DS between two and six years old shown a significativily lower serum retinol (p=<0.05).The patients with DS also showed a significant decrease in height and weight compared to KN (p=<0.001). Conclusions: The prevalence of VAD detected in patients with DS could be considered a public health problem. Also, the chromosome 21 trisomy represent a risk factor associated with VAD (AU)

[Vitamin A deficiency and nutritional status in patients with Down's syndrome]. / Deficiencia de vitamina A y estado nutricional en pacientes con Síndrome de Down.

INTRODUCTION: Vitamin A deficiency (VAD) is a worldwide public health problem. Epidemiological studies of VAD prevalence have been conducted in individuals with chromosome load and genetic potential compared with the general population; however, there are few studies in patients with Down's syndrome (DS). The objective of this study was to determine the prevalence of VAD and analyse nutritional status in patients with DS. METHODS: A prospective and cross-sectional study was performed, with 50 karyotypically normal (KN) individuals (10.4+/-3.7 years old) and 38 randomly selected patients with DS (8.2+/-4.1 years old). Serum retinol was determined by HPLC using the Bieri method, with an international reference standard to define VAD (serum retinol <20 microg/dL). The data were analysed using the SAS/STAT statistical program. RESULTS: The prevalence of VAD was 18.4% in individuals with DS and 4% in KN individuals (OR: 5.42; 95% CI=0.93-40.64; p=0.02). Children with DS between two and six years old shown a significativily lower serum retinol (p=<0.05).The patients with DS also showed a significant decrease in height and weight compared to KN (p=<0.001). CONCLUSIONS: The prevalence of VAD detected in patients with DS could be considered a public health problem. Also, the chromosome 21 trisomy represent a risk factor associated with VAD.

Reconstruction of venous outflow of domino liver graft using deceased donor iliac/cava veins.

The double piggyback technique has been proposed for domino liver transplantation. To make this possible, it is necessary to reconstruct the venous outflow of the domino liver graft on the back table. The authors describe the technical details of this procedure in three consecutive cases. A deceased donor cava-iliac bifurcation segment was used. The iliac veins were anastomosed to the ostia of the right and middle-left hepatic veins, and the graft cava vein was anastomosed to the ostium of the three hepatic veins of the recipient. In all cases anatomic compatibility was observed; the outcome of the patients was satisfactory.

Case report: spontaneous rupture of the spleen due to dengue fever

Spontaneous rupture of the spleen has been described in cases of hematologic, neoplasic and infectious diseases, or resulting from pancreatitis. We report a rare case of spontaneous splenic rupture, and favorable evolution after splenectomy, in a patient with dengue fever, which occurred during the last outbreak of dengue fever in Brazil.

Case report: spontaneous rupture of the spleen due to dengue fever.

Spontaneous rupture of the spleen has been described in cases of hematologic, neoplasic and infectious diseases, or resulting from pancreatitis. We report a rare case of spontaneous splenic rupture, and favorable evolution after splenectomy, in a patient with dengue fever, which occurred during the last outbreak of dengue fever in Brazil.

Extended-spectrum beta-lactamase-producing Klebsiella pneumoniae in a neonatal intensive care unit: risk factors for infection and colonization.

An outbreak of extended spectrum beta-lactamase-producing Klebsiella pneumoniae (ESBLKp) infections in a neonatal intensive care unit (NICU) prompted a prospective investigation of colonization and infection with this pathogen. From August 1, 1997 to May 30, 1999, neonates admitted to the NICU for more than 24 h were screened for ESBLKp acquisition. Neonatal gastrointestinal screening was performed by means of faecal sampling within 48 h of admission and then weekly until discharge. Isolates were typed using pulsed-field gel electrophoresis (PFGE). Time-dependent proportional hazard models were used to identify independent effects of invasive procedures and antimicrobials after controlling for duration of stay at the NICU. During the study period, 464 neonates were admitted and 383 were regularly screened. Infections occurred in 13 (3.4%) neonates and 206 (53.8%) became colonized. Independent risk factors for colonization during the first nine days in the NICU were the antimicrobial combination cephalosporin plus aminoglycoside [hazard rate (HR)=4.60; 95% CI: 1.48-14.31], and each NICU-day was associated with a 26% increase in the hazard rate for colonization (HR=1.26; 95% CI: 1.16-1.37). Previous colonization (HR=5.19; 95% CI: 1.58-17.08) and central vascular catheter use (HR=13.89; 95% CI: 2.71-71.3) were independent risk factors for infection. In an outbreak setting the proportion of neonates colonized with ESBLKp was observed to increase with the duration of stay and antimicrobial use, and once colonized, infants exposed to invasive devices may become infected.

Clinical experience with balanced reciprocal translocations.

Clinical experience with balanced reciprocal translocations: In order to evaluate past experience with respect to the occurrence of balanced reciprocal translocations (BRT) in patients with malformation syndromes and/or mental retardation (MS/MR) and in couples with reproductive failure, 4,335 karyotypes from the Genetics Unit of the Universidad del Zulia from January 1971 to December 1994 were reviewed, resulting in the identification of 15 cases of BRT (0.34%). All BRT were classic (CT) according to the number of breakpoints. In 66.6% of the cases, the indication for chromosome analysis was a MS/MR; 20% reproductive failure and, in 13.3% the BRT was a fortuitous finding. BRT were of familial origin in 6/15 (40%), 3/15 (20%) were de novo and the other 6/15 (40%) were of unknown origin. It was concluded that BRT can affect the phenotype, particularly when the request for the karyotype is motivated by MS/MR, and that genetic counseling in individuals at risk to be carrier is indicated.

Perinatal glucose homeostasis: the unique character of hyperglycemia and hypoglycemia in infants of very low birth weight.

Tiny babies have the potential problem of hypoglycemia due to diminished hepatic glycogen stores, which can be potentiated by conditions frequently present in this birth weight group: asphyxia, cold stress, hypoxia, polycythemia. Despite the early administration of fluid and feeding, tiny babies are still at risk for developing hypoglycemia. Their immaturity, expressed by their limited ability to tolerate parenteral glucose infusions, puts them at risk for becoming hyperglycemic as well. Hence careful glucose administration and frequent monitoring of blood glucose are essential during the first several days after birth, in anticipation of hypoglycemia as well as hyperglycemia.