Mammalia, Didelphimorphia and Rodentia, southwest of the province of Mendoza, Argentina

We documented terrestrial micromammal assemblages at five localities of southwestern Mendoza province, Argentina. We added new localities for several of the most uncommon small mammal species of this region (e.g. Loxodontomys micropus and Tympanoctomys barrerae). Two main groups of terrestrial non-volant micromammals are represented in southwestern province of Mendoza: one group is related to the South American arid diagonal, and includes species typically adapted to the xeric environments of the Monte Desert; a second group includes Patagonian and High Andean species. Some Patagonian species reached in the study area their northernmost distributional records (e.g. Abrothrix longipilis, A. olivaceus, Chelemys macronyx, Loxodontomys micropus).Fil: Pardiñas, Ulises Francisco J.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; ArgentinaFil: Teta, Pablo Vicente. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Ecología, Genética y Evolución; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Udrizar Sauthier, Daniel Edgardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; Argentin

Ctenomys conoveri Osgood, 1946 (Rodentia, Ctenomyidae), a new mammal for Argentina

Se presenta el primer registro de Ctenomys conoveri Osgood, 1946 (Rodentia, Ctenomyidae) para Argentina a partir de un ejemplar colectado en río Itiyuro (22°30 ‘S, 63° 30‘O), Tonono, Salta, en 1950. La especie era previamente conocida del sur de Bolivia y el oeste Paraguay. Se desconoce la situación actual de las poblaciones argentinas, si es que todavía existen. El nuevo registro destaca lanecesidad de realizar nuevos relevamientos mastozoológicos en el Chaco Seco.We present the first record for Ctenomys conoveri Osgood, 1946 (Rodentia, Ctenomyidae) for Argentina from a specimen collected at Itiyuro river (22 ° 30 ‘S, 63 ° 30’O), Tonono, Salta, in 1950. This species was previously known for southern Bolivia and western Paraguay. The current status of the Argentine populations, if they still exist, is unknown. This new record highlights the need for conducting new mammalogical surveys in the Dry Chaco.Fil: Teta, Pablo Vicente. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales ; ArgentinaFil: Ríos, Sergio Daniel. Secretaría Nacional de Cultura. Departamento de Arqueología y Paleontología; Paraguay. Museo Nacional de Historia Natural del Paraguay; Paragua

Incidence, complications and risk factors for severe falls in patients on maintenance haemodialysis

Background. Falls have been insufficiently studied in patients on maintenance haemodialysis (MHD). This study assessed the incidence and complications of severe falls and the ability of risk factors, including the Performance-Oriented Mobility Assessment (POMA) test, to predict them in this population. Methods. All patients on MHD from our centre were asked to participate in this survey. POMA test and a record of risk factors for falls were obtained at baseline. Severe falls, as defined by an admission in an emergency ward, were documented prospectively. Results. Eighty-four patients (median age 69.5 years, minimum 26 years, maximum 85 years) were enrolled. Predialytic POMA scores were low (median 20, minimum 5, maximum 26). After a mean follow-up of 20.6 months (142.2 patient-years), 31 severe falls were recorded in 24 patients (28.6%; incidence 0.22 per patient-year) and complicated by fractures in 54.8% of severe falls. In univariate analysis, age, a past history of falls, malnutrition, depression, but not POMA score, were associated with severe falls. A POMA score of >21 had a negative predictive value of 82%. Conclusions. Severe falls were common in MHD patients in this study and resulted in fractures in >50% of the cases. They were associated with ageing, a past history of falls, malnutrition and depression. Although there was a trend towards a lower POMA score in fallers as compared to non-fallers, the POMA score was not an independent predictor of severe falls in this study. These data may help to stratify the patient's risk of falling in order to target programmes to prevent falls in this populatio

The effect of pH-neutral peritoneal dialysis fluids on adipokine secretion from cultured adipocytes

Background. Adipokines are a group of fat-secreted hormones and cytokines, including leptin and adiponectin, with important functions in humans. Peritoneal dialysis (PD) is associated with markedly raised plasma adipokines, suggesting increased production in this setting. We have shown that low pH down-regulates leptin production. The current study was designed to test if novel pH-neutral PD fluids may regulate leptin and adiponectin secretion in vitro. Methods. We exposed 3T3-L1 adipocytes to a 50 : 50 mixture of dialysate and M199 containing 10% serum for upto 48 h. Dialysates were commercial PD fluids, i.e. conventional acidic, lactate-buffered solutions (PD-acid) and pH-neutral lactate-buffered (PD-Bal) or bicarbonate-buffered solutions (PD-Bic). Leptin and adiponectin concentrations in culture-cell media were measured by ELISA. Results. Compared with PD-acid, PD-Bal and PD-Bic produced a 25 and 43% increase, respectively, in leptin secretion at 48 h (P < 0.05). In contrast, adiponectin secretion was not affected. High glucose PD fluids (4.25%) specifically inhibited leptin secretion vs 1.5% glucose, buffer-matched solutions (P < 0.05). However, differences in leptin secretion due to pH and type of buffer remained significant. In further experiments, the pH of test media were extensively varied without the presence of dialysates. Leptin secretion was shown to increase in a parallel to pH, whereas large changes in pH did not affect adiponectin secretion. Conclusion. The pH-neutral PD solutions specifically induce leptin, but not adiponectin secretion from 3T3-L1 adipocytes. PD-Bic produced a greater leptin stimulation than PD-Bal, but this difference was attributable to pH per se, rather than the type of buffe

Glucose-containing peritoneal dialysis fluids regulate leptin secretion from 3T3-L1 adipocytes

Background. A marked elevation of serum leptin is observed soon after the start of peritoneal dialysis (PD), suggesting that leptin production may be stimulated by this treatment. Glucose metabolism is the major factor regulating leptin. The current study was designed to test if glucose-based PD fluids might regulate leptin production in vitro. Methods. 3T3-L1 adipocytes were exposed to a 50:50 mixture of dialysis solutions and medium M199 containing 10% serum for ≤48 h. Leptin secretion in culture cell supernatants was measured by enzyme-linked immunosorbent assay and leptin mRNA content by northern blot analysis. Results. The high glucose-based commercial dialysate PD4 produced a higher leptin secretion compared with an identical laboratory-manufactured dialysate (Lab-D), but with a physiological glucose concentration of 5 mM (P<0.05). Raising glucose concentration from 2.75 to 40 mM in Lab-D induced a dose-dependent increase in leptin secretion of ≤110±12% at 48 h (P<0.001) and leptin mRNA (P<0.05; glucose 2.75 vs 40 mM). Inhibition of UDP-N-acetylglucosamine biosynthesis, with 6-diazo-5-oxo-norleucine added to Lab-D, abolished most of the glucose-stimulated leptin release and downregulated leptin gene expression. Furthermore, glucose-free Lab-D supplemented with 1 mM glucosamine, an intermediate product in UDP-N-acetylglucosamine biosynthesis, increased leptin secretion by 28±11% over control (P<0.05), although without effect on leptin mRNA, after 48 h of culture. Conclusions. These results suggest that the PD-induced hyperleptinaemia could, in part, be mediated by the effect of glucose-based dialysis fluids on leptin production by adipocytes via activation of the hexosamine biosynthetic pathwa

Is intra-operative blood flow predictive for early failure of radiocephalic arteriovenous fistula?

Background. For over 50 years, radiocephalic wrist arteriovenous fistulae (RCAVF) have been the primary and best vascular access for haemodialysis. Nevertheless, early failure due to thrombosis or non-maturation is a major complication resulting in their abandonment. This prospective study was designed to investigate the predictive value of intra-operative blood flow on early failure of primary RCAVF before the first effective dialysis. Methods. We enrolled patients undergoing creation of primary RCAVF for haemodialysis based on the pre-operative ultrasound vascular mapping discussed in a multidisciplinary approach. Intra-operative blood flow measurement was systematically performed once the anastomosis had been completed using a transit-time ultrasonic flowmeter. During the follow-up, blood flow was estimated by colour flow ultrasound at various intervals. Any events related to the RCAVF were recorded. Results. Autogenous RCAVFs (n = 58) in 58 patients were constructed and followed up for an average of 30 days. Thrombosis and non-maturation occurred in eight (14%) and four (7%) patients, respectively. The intra-operative blood flow in functioning RCAVFs was significantly higher compared to non-functioning RCAVFs (230 vs 98 mL/min; P = 0.007), as well as 1 week (753 vs 228 mL/min; P = 0.0008) and 4 weeks (915 vs 245 mL/min, P < 0.0001) later. Blood flow volume measurements with a cut-off value of 120 mL/min had a sensitivity of 67%, specificity of 75% and positive predictive value of 91%. Conclusions. Blood flow <120 mL has a good predictive value for early failure in RCAVF. During the procedure, this cut-off value may be used to select appropriately which RCAVF should be investigated in the operation theatre in order to correct in real time any abnormalit

Loxodontomys micropus (Rodentia: Cricetidae)

Loxodontomys micropus (Waterhouse, 1837) is a cricetid commonly called the southern pericote. A moderately large, heavy-bodied rodent, it is 1 of the 2 species in the genus Loxodontomys. This cricetid occurs in southern Chile and southwestern Argentina. It prefers humid, dense grasslands, meadows, shrubby steppes, and mixed or open-canopied Nothofagus forests. L. micropus is categorized as of least concern.Fil: Teta, Pablo Vicente. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Ecología, Genética y Evolución; ArgentinaFil: Pardiñas, Ulises Francisco J.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico; ArgentinaFil: Udrizar Sauthier, Daniel Edgardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico; ArgentinaFil: D'elía, Guillermo. Universidad de Concepción; Chil

Use of a renal-specific oral supplement by haemodialysis patients with low protein intake does not increase the need for phosphate binders and may prevent a decline in nutritional status and quality of life

Background. Protein-energy wasting is a frequent and debilitating condition in maintenance dialysis. We randomly tested if an energy-dense, phosphate-restricted, renal-specific oral supplement could maintain adequate nutritional intake and prevent malnutrition in maintenance haemodialysis patients with insufficient intake. Methods. Eighty-six patients were assigned to a standard care (CTRL) group or were prescribed two 125-ml packs of Renilon 7.5® daily for 3 months (SUPP). Dietary intake, serum (S) albumin, prealbumin, protein nitrogen appearance (nPNA), C-reactive protein, subjective global assessment (SGA) and quality of life (QOL) were recorded at baseline and after 3 months. Results. While intention to treat analysis (ITT) did not reveal strong statistically significant changes in dietary intake between groups, per protocol (PP) analysis showed that the SUPP group increased protein (P < 0.01) and energy (P < 0.01) intakes. In contrast, protein and energy intakes further deteriorated in the CTRL group (PP). Although there was no difference in serum albumin and prealbumin changes between groups, in the total population serum albumin and prealbumin changes were positively associated with the increment in protein intake (r = 0.29, P = 0.01 and r = 0.27, P = 0.02, respectively). The SUPP group did not increase phosphate intake, phosphataemia remained unaffected, and the use of phosphate binders remained stable or decreased. The SUPP group exhibited improved SGA and QOL (P < 0.05). Conclusion. This study shows that providing maintenance haemodialysis patients with insufficient intake with a renal-specific oral supplement may prevent deterioration in nutritional indices and QOL without increasing the need for phosphate binder

Mammalia, Rodentia, Sigmodontinae, Loxodontomys micropus: new locality records

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