Salt subtraction in patients on maintenance hemodialysis. Efficacy and limitations.

In 6 hypertensive patients with terminal renal failure maintained on hemodialysis, the effects of 'salt subtraction' and of sequential ultrafiltrating were evaluated. Following each of 3 weekly hemodialysis sessions, salt subtraction was carried out by ultrafiltrating 1 liter and simultaneously infusing an equal volume of 5% dextrose. This resulted in a net sodium loss without hypovolemia. After a 2-week period of this procedure, the blood pressure prior to dialysis was lower (156/76 +/- 12/5 mm Hg) than after a comparable number of sequential ultrafiltration sessions (181/88 +/- 10/6 mm Hg; mean +/- SEM). This difference was not statistically significant. At the same time, body weight was comparable at 64.4 +/- 3 and 64.7 +/- 4 kg, respectively. Neither plasma renin activity nor plasma catecholamines responded with a clear increase to either procedure. The limited effect on blood pressure and the renin system of a marked sodium removal during salt subtraction suggests that sodium must still be present in excess in these patients. The procedure of salt subtraction appears safe and subjectively well tolerated, but it can probably not be used as the sole means of decreasing total body sodium without associating dietary measures to reduce sodium intake.

Patogenicidade de isolados de Metarhizium anisopliae (Metsch.) Sorokin e de Beauveria bassiana (Bals.) Vuillemin a Scaptocoris carvalhoi Becker (Hemiptera, Cydnidae)

Avaliou-se a patogenicidade de isolados dos fungos Metarhizium anisopliae (Metsch.) Sorokin e Beauveria bassiana (Bals.) Vuillemin a Scaptocoris carvalhoi Becker, 1967 sob condições de laboratório e em casa de vegetação. Os experimentos foram conduzidos na Embrapa Agropecuária Oeste de Dourados, MS, durante o ano de 2003. Foram avaliados dez isolados de M. anisopliae e onze de B. bassiana, em laboratório, utilizando-se o delineamento inteiramente casualizado, com cinco repetições (10 adultos e 5 ninfas/parcela). A patogenicidade de M. anisopliae (Ma69) também foi testada em ninfas e adultos, separadamente, em laboratório e casa de vegetação. Os níveis de mortalidade do percevejo foram maiores com os isolados de M. anisopliae que variaram de 73,3% a 94,7% contra 10,7% a 78,7% para os de B. bassiana. Em casa de vegetação, a porcentagem de mortalidade do percevejo causada pelo fungo Ma69 foi de 57,3% e não foi constatada diferença por este isolado quanto à mortalidade de ninfas e adultos, em laboratório. Todavia, em casa de vegetação, os níveis de mortalidade foram significativamente maiores (p<0,05) para ninfas (38,4%) do que para os adultos (16,2%). Com base nos resultados obtidos, concluiu-se que o isolado Ma69 de M. anisopliae foi mais eficiente para S. carvalhoi tanto em laboratório quanto em casa de vegetação, constituindo em uma alternativa promissora para ser utilizado como inseticida microbiano em condições de campo.

Efectos de la Densidad y Profundidad en la Crianza de la Concha de Abanico (Argopecten purpuratus ) en Cultivos Suspendidos

Entre los meses de mayo de 1983 y febrero de 1984 se efectuaron en la Bahía de Paracas dos experimentos de cultivo de Argopecten purpuratus: uno usando diferentes densidades iniciales (137, 205, 274, 342, y 411 conchas por m2) a 2 m de profundidad y otro en diferentes profundidades (1, 3, 5, y 7 m) con una densidad inicial de 145 ind./m2• La densidad inicial de 342 ind./m2 fue determinada como la optima, llegando a la talla comercial de 70 mm en 204 días y a una carga de 25.5 kg/m2• Cargas de casi 30 kg/m2 fueron obtenidas después de 230 días pero experimentan una fuerte reducción en la tasa de crecimiento y una alta mortalidad. En el experimento a diferentes profundidades las mayores tasas de crecimiento individual y cargas fueron obtenidas en 3 m.

The lesser cotton leafworm, Anomis impasta (Guenée) (Lepidoptera, Noctuidae), in cotton

Anomis impasta (Guenée) is a species that shows remarkable morphological and behavioral similarities with the cotton leafworm Alabama argillacea (Hübner). During two growing cotton seasons, A. impasta was observed feeding on leaves and flower bracts of cotton and monitored. Furthermore, a study was conducted under laboratory conditions to generate biological information about this species with larvae feeding cotton squares and leaves. Larvae fed on cotton squares exhibited delayed development (18.5 ± 0.18 days) and lower pupal weight (140.8 ± 2.26 mg) compared to larvae fed on cotton leaves (14.0 ± 0.07 days and 169.3 ± 2.06 mg). Thus, one generation cycle of A. impasta was obtained by feeding the larvae with cotton leaves. The mean (minimum-maximum) values for the duration of eggs, larvae and pupae were: 3.0 (3-4), 14.8 (14-18), and 9.7 (7-14) days, respectively. The viability of the eggs, larvae, and pupae were 43.7, 98.3, and 94.7%, respectively. Females lived on average 25.2 days (ranging from 15 to 37 days) and produced 869 eggs (from 4 to 1,866 eggs). The successful development and reproduction of A. impasta on cotton, especially, on the cotton leaves, suggest the potential of this species to reach a pest status in cotton. The similarities with A. argillacea, as discussed in this study, can be one of the reasons for low reference to A. impasta in the field. Therefore, the information provided here will allow researchers and growers to distinguish these two cotton defoliators.

Condición reproductiva y fecundidad de Vinciguerria lucetia pecific durante el crucero BIC Humboldt 9808-09

Describe el estado reproductivo de Vinciguerria lucetia pacifici a través del análisis histológico de ovarios por grados latitudinales. Se elabora una escala de madurez sexual de cinco estadíos. Durante la ejecución del Crucero 9808-09, efectuado entre el 20 de agosto y el 18 de setiembre de 1998 la Vinciguerria lucetia pacifici se encontró en plena etapa de desove. La talla de los individuos estuvo comprendida entre 3,5 y 7,0 cm de longitud total. Esta especie tiene un desarrollo ovocitario asincrónico y un tipo de desove parcial. Se estimó la fecundidad parcial promedio en 309 ovocitos por hembra (DS=164).

Enterococcal endocarditis in the beginning of the 21st century: analysis from the International Collaboration on Endocarditis-Prospective Cohort Study.

Enterococci are reportedly the third most common group of endocarditis-causing pathogens but data on enterococcal infective endocarditis (IE) are limited. The aim of this study was to analyse the characteristics and prognostic factors of enterococcal IE within the International Collaboration on Endocarditis. In this multicentre, prospective observational cohort study of 4974 adults with definite IE recorded from June 2000 to September 2006, 500 patients had enterococcal IE. Their characteristics were described and compared with those of oral and group D streptococcal IE. Prognostic factors for enterococcal IE were analysed using multivariable Cox regression models. The patients' mean age was 65 years and 361/500 were male. Twenty-three per cent (117/500) of cases were healthcare related. Enterococcal IE were more frequent than oral and group D streptococcal IE in North America. The 1-year mortality rate was 28.9% (144/500). E. faecalis accounted for 90% (453/500) of enterococcal IE. Resistance to vancomycin was observed in 12 strains, eight of which were observed in North America, where they accounted for 10% (8/79) of enterococcal strains, and was more frequent in E. faecium than in E. faecalis (3/16 vs. 7/364 , p 0.01). Variables significantly associated with 1-year mortality were heart failure (HR 2.4, 95% CI 1.7--3.5, p <0.0001), stroke (HR 1.9, 95% CI 1.3--2.8, p 0.001) and age (HR 1.02 per 1-year increment, 95% CI 1.01--1.04, p 0.002). Surgery was not associated with better outcome. Enterococci are an important cause of IE, with a high mortality rate. Healthcare association and vancomycin resistance are common in particular in North America.

Systematic study of the static electrical properties of the CO molecule: influence of the basis set size and correlation energy

The influence of the basis set size and the correlation energy in the static electrical properties of the CO molecule is assessed. In particular, we have studied both the nuclear relaxation and the vibrational contributions to the static molecular electrical properties, the vibrational Stark effect (VSE) and the vibrational intensity effect (VIE). From a mathematical point of view, when a static and uniform electric field is applied to a molecule, the energy of this system can be expressed in terms of a double power series with respect to the bond length and to the field strength. From the power series expansion of the potential energy, field-dependent expressions for the equilibrium geometry, for the potential energy and for the force constant are obtained. The nuclear relaxation and vibrational contributions to the molecular electrical properties are analyzed in terms of the derivatives of the electronic molecular properties. In general, the results presented show that accurate inclusion of the correlation energy and large basis sets are needed to calculate the molecular electrical properties and their derivatives with respect to either nuclear displacements or/and field strength. With respect to experimental data, the calculated power series coefficients are overestimated by the SCF, CISD, and QCISD methods. On the contrary, perturbation methods (MP2 and MP4) tend to underestimate them. In average and using the 6-311 + G(3df) basis set and for the CO molecule, the nuclear relaxation and the vibrational contributions to the molecular electrical properties amount to 11.7%, 3.3%, and 69.7% of the purely electronic μ, α, and β values, respectively

Neurally adjusted ventilatory assist can improve arterial oxygenation

INTRODUCTION. Neurally Adjusted Ventilatory Assist (NAVA) [1] is a new spontaneousassisted ventilatory mode which uses the diaphragmatic electrical activity (Eadi) to pilot the ventilator. Eadi is used to initiate the ventilator's pressurization and cycling off. Delivered inspiratory assistance is proportional to Eadi. NAVA can improve patient-ventilator synchrony [2] compared to pressure support (PS), but little is known about its effect on minute ventilation and oxygenation. OBJECTIVES. To compare the effects of NAVA and PS on minute ventilation and oxygenation and to analyze potential determinant factors for oxygenation. METHODS. Comparison between two 20-min periods under NAVA and PS. NAVA gain (proportionality factor between Eadi and delivered pressure) set as to obtain the same peak pressure as in PS. FIO2 and positive end-expiratory pressure (PEEP) were the same in NAVA and PS. Blood gas analyses were performed at the end of both recording periods. Statistical analysis: groups were compared with paired t tests or non parametric Wilcoxon signed-rank tests. p\0.05 was considered significant. RESULTS. [Mean ± SD]: 22 patients (age 66 ± 12 year, 7 M/15F, BMI 23.4 ± 3.1 kg/m2), 8 patients with COPD. Initial settings: PS 13 ± 3 cmH2O, PEEP 7 ± 2 cmH2O, NAVA gain 2.2 ± 1.8. Minute ventilation and PaCO2 were the same with both modes (p = 0.296 and 0.848, respectively). Tidal volume was lower with NAVA (427 ± 102 vs. 477 ± 102 ml, p\0.001). In contrast respiratory rate was higher with NAVA (25.6 ± 9.5 vs. 22.3 ± 8.9 cycles/min). Arterial oxygenation was improved with NAVA (PaO2 85.1 ± 28.9 vs. 75.8 ± 11.9 mmHg, p = 0.017, PaO2/FIO2 210 ± 53 vs. 195 ± 58 mmHg, p = 0.019). Neural inspiratory time (Tin) was comparable between NAVA and PS (p = 0.566). Among potential determinant factors for oxygenation, mean airway pressure (Pmean) was lower with NAVA (10.6 ± 2.6 vs. 11.1 ± 2.4 cmH2O, p = 0.006), as was the pressure time product (PTP) (6.8 ± 3.0 vs. 9.2 ± 3.5 cmH2O 9 s, p = 0.004). There were less asynchrony events with NAVA (2.3 ± 2.0 vs. 4.4 ± 3.8, p = 0.009).Tidal volume variability was higher with NAVA (variation coefficient: 30 ± 19.5 vs. 13.5 ± 8.6, p\0.001). Inspiratory time in excess (Tiex) was lower with NAVA (56 ± 23 vs. 202 ± 200 ms, p = 0.001). CONCLUSION. Despite lower Pmean and PTP in NAVA, arterial oxygenation was improved compared to PS. As asynchronies may be associated with an increased work of breathing and a higher oxygen consumption, their decrease in number with NAVA could be an explanation for oxygenation improvement. Another explanation could be the increase in VT variability. Further studies should now be performed to confirm the potential of NAVA in improving arterial oxygenation and explore the underlying mechanisms.

Produtividade de um solo litólico associada ao controle da erosão por cordões de pedra em contorno

Pesquisas prévias demonstraram a eficiência de cordões de pedra em contorno na redução do comprimento de encostas, no decréscimo das taxas de enxurradas e de erosão, na retenção de sedimentos e de nutrientes e no decréscimo do assoreamento de reservatórios. O dimensionamento desse benefício em termos de produtividade do solo em regiões semi-áridas, entretanto, não fora ainda estabelecido. Este trabalho foi desenvolvido no sentido de determinar os efeitos de cordões de pedra em contorno na produtividade de um solo litólico, determinada nas áreas de remoção do solo e nos locais onde os sedimentos eram retidos e depositados, treze anos após sua construção. O experimento foi executado em Quixadá (CE), de março a julho de 1994. A produtividade natural do solo, não alterada por fertilizantes, foi avaliada em termos de rendimentos de feijão-de-corda e de milho e sua produção de biomassa. Em áreas de deposição, onde os sedimentos foram retidos pelos cordões de pedra em contorno, os aumentos no número de vagens por planta, no número e no peso de grãos por planta, e no rendimento de feijão-de-corda, foram, respectivamente, de 48,6, 140,0, 86,4 e 85,5%, quando comparados a esses parâmetros determinados nas áreas de remoção do solo. A produção de milho também foi afetada beneficativamente pelos cordões de pedra em contorno, posto que a altura das plantas, o comprimento das espigas e o rendimento foram, respectivamente, 12,3 e 20,7% maiores nos locais de deposição em relação às áreas de remoção do solo.

Efficacy of daptomycin in implant-associated infection due to methicillin-resistant Staphylococcus aureus: importance of combination with rifampin.

Limited treatment options are available for implant-associated infections caused by methicillin (meticillin)-resistant Staphylococcus aureus (MRSA). We compared the activity of daptomycin (alone and with rifampin [rifampicin]) with the activities of other antimicrobial regimens against MRSA ATCC 43300 in the guinea pig foreign-body infection model. The daptomycin MIC and the minimum bactericidal concentration in logarithmic phase and stationary growth phase of MRSA were 0.625, 0.625, and 20 microg/ml, respectively. In time-kill studies, daptomycin showed rapid and concentration-dependent killing of MRSA in stationary growth phase. At concentrations above 20 microg/ml, daptomycin reduced the counts by >3 log(10) CFU/ml in 2 to 4 h. In sterile cage fluid, daptomycin peak concentrations of 23.1, 46.3, and 53.7 microg/ml were reached 4 to 6 h after the administration of single intraperitoneal doses of 20, 30, and 40 mg/kg of body weight, respectively. In treatment studies, daptomycin alone reduced the planktonic MRSA counts by 0.3 log(10) CFU/ml, whereas in combination with rifampin, a reduction in the counts of >6 log(10) CFU/ml was observed. Vancomycin and daptomycin (at both doses) were unable to cure any cage-associated infection when they were given as monotherapy, whereas rifampin alone cured the infections in 33% of the cages. In combination with rifampin, daptomycin showed cure rates of 25% (at 20 mg/kg) and 67% (at 30 mg/kg), vancomycin showed a cure rate of 8%, linezolid showed a cure rate of 0%, and levofloxacin showed a cure rate of 58%. In addition, daptomycin at a high dose (30 mg/kg) completely prevented the emergence of rifampin resistance in planktonic and adherent MRSA cells. Daptomycin at a high dose, corresponding to 6 mg/kg in humans, in combination with rifampin showed the highest activity against planktonic and adherent MRSA. Daptomycin plus rifampin is a promising treatment option for implant-associated MRSA infections.

Fuel metabolism during exercise in euglycaemia and hyperglycaemia in patients with type 1 diabetes mellitus--a prospective single-blinded randomised crossover trial.

Aims/hypothesis We assessed systemic and local muscle fuel metabolism during aerobic exercise in patients with type I diabetes at euglycaemia and hyperglycaemia with identical insulin levels.Methods This was a single-blinded randomised crossover study at a university diabetes unit in Switzerland. We studied seven physically active men with type I diabetes (mean +/- SEM age 33.5 +/- 2.4 years, diabetes duration 20.1 +/- 3.6 years, HbA(1c) 6.7 +/- 0.2% and peak oxygen uptake [VO2peak] 50.3 +/- 4.5 ml min(-1) kg(-1)). Men were studied twice while cycling for 120 min at 55 to 60% of VO2peak, with a blood glucose level randomly set either at 5 or 11 mmol/l and identical insulinaemia. The participants were blinded to the glycaemic level; allocation concealment was by opaque, sealed envelopes. Magnetic resonance spectroscopy was used to quantify intramyocellular glycogen and lipids before and after exercise. Indirect calorimetry and measurement of stable isotopes and counter-regulatory hormones complemented the assessment of local and systemic fuel metabolism.Results The contribution of lipid oxidation to overall energy metabolism was higher in euglycaemia than in hyperglycaemia (49.4 +/- 4.8 vs 30.6 +/- 4.2%; p<0.05). Carbohydrate oxidation accounted for 48.2 +/- 4.7 and 66.6 +/- 4.2% of total energy expenditure in euglycaemia and hyperglycaemia, respectively (p<0.05). The level of intramyocellular glycogen before exercise was higher in hyperglycaemia than in euglycaemia (3.4 +/- 0.3 vs 2.7 +/- 0.2 arbitrary units [AU]; p<0.05). Absolute glycogen consumption tended to be higher in hyperglycaemia than in euglycaemia (1.3 +/- 0.3 vs 0.9 +/- 0.1 AU). Cortisol and growth hormone increased more strongly in euglycaemia than in hyperglycaemia (levels at the end of exercise 634 52 vs 501 +/- 32 nmol/l and 15.5 +/- 4.5 vs 7.4 +/- 2.0 ng/ml, respectively; p<0.05).Conclusions/interpretation Substrate oxidation in type I diabetic patients performing aerobic exercise in euglycaemia is similar to that in healthy individuals revealing a shift towards lipid oxidation during exercise. In hyperglycaemia fuel metabolism in these patients is dominated by carbohydrate oxidation. Intramyocellular glycogen was not spared in hyperglycaemia.