A reply to "Relevant factors in the eutrophication of the Uruguay River and the Río Negro".

A recent paper by Beretta-Blanco and Carrasco-Letelier (2021) claims that agricultural eutrophication is not one of the main causes for cyanobacterial blooms in rivers and artificial reservoirs. By combining rivers of markedly different hydrological characteristics e.g., presence/absence and number of dams, river discharge and geological setting, the study speculates about the role of nutrients for modulating phytoplankton chlorophyll-a. Here, we identified serious flaws, from erratic and inaccurate data manipulation. The study did not define how erroneous original dataset values were treated, how the variables below the detection/quantification limit were numerically introduced, lack of mandatory variables for river studies such as flow and rainfall, arbitrary removal of pH > 7.5 values (which were not outliers), and finally how extreme values of other environmental variables were included. In addition, we identified conceptual and procedural mistakes such as biased construction/evaluation of model prediction capability. The study trained the model using pooled data from a short restricted lotic section of the (large) Uruguay River and from both lotic and reservoir domains of the Negro River, but then tested predictability within the (small) Cuareim River. Besides these methodological considerations, the article shows misinterpretations of the statistical correlation of cause and effect neglecting basic limnological knowledge of the ecology of harmful algal blooms (HABs) and international research on land use effects on freshwater quality. The argument that pH is a predictor variable for HABs neglects overwhelming basic paradigms of carbon fluxes and change in pH because of primary productivity. As a result, the article introduces the notion that HABs formation are not related to agricultural land use and water residence time and generate a great risk for the management of surface waterbodies. This reply also emphasizes the need for good practices of open data management, especially for public databases in view of external reproducibility.

A rhamnose-binding lectin from Rhodnius prolixus and the impact of its silencing on gut bacterial microbiota and Trypanosoma cruzi.

Lectins are ubiquitous proteins involved in the immune defenses of different organisms and mainly responsible for non-self-recognition and agglutination reactions. This work describes molecular and biological characterization of a rhamnose-binding lectin (RBL) from Rhodnius prolixus, which possesses a 21 amino acid signal peptide and a mature protein of 34.6 kDa. The in-silico analysis of the primary and secondary structures of RpLec revealed a lectin domain fully conserved among previous insects studied. The three-dimensional homology model of RpLec was similar to other RBL-lectins. Docking predictions with the monosaccharides showed rhamnose and galactose-binding sites comparable to Latrophilin-1 and N-Acetylgalactosamine-binding in a different site. The effects of RpLec gene silencing on levels of infecting Trypanosoma cruzi Dm 28c and intestinal bacterial populations in the R. prolixus midgut were studied by injecting RpLec dsRNA into the R. prolixus hemocoel. Whereas T. cruzi numbers remained unchanged compared with the controls, numbers of bacteria increased significantly. The silencing also induced the up regulation of the R. prolixus defC (defensin) expression gene. These results with RpLec reveal the potential importance of this little studied molecule in the insect vector immune response and homeostasis of the gut bacterial microbiota.

Contribución proximal del nervio ulnar para la formación del nervio digital palmar propio ulnar del dedo mínimo / Proximal contribution of the ulnar nerve in the formation of the ulnar proper palmar digital nerve of the little finger

La anatomía de la mano presenta padrones generales en la distribución de los nervios responsables de la inervación motora y sensitiva. Sin embargo, se encuentran variaciones que son de interés para la anatomía quirúrgica de la región. En una serie de 20 manos disecadas, en 19 (95 por ciento) observamos que el nervio digital palmar propio del lado ulnar del dedo mínimo correspondía a un ramo directo del nervio ulnar y en el caso restante (5 por ciento), de un cadáver de sexo femenino, se observó un ramo de origen antebraquial que participó en la formación del nervio digital palmar propio ulnar del dedo mínimo. Este ramo se originó desde el tronco del nervio ulnar, distal al origen del ramo dorsal de este nervio y proximal al hueso pisiforme. En su trayecto pasó a través del músculo abductor del dedo mínimo, emergiendo por la cara superficial de éste a una distancia de 11,3 mm del origen del músculo en el hueso pisiforme, uniéndose al nervio digital palmar propio del dedo mínimo, distal al hueso mencionado. A pesar que la literatura muestra diversas variaciones en la formación y distribución de los nervios en la mano, la disposición descrita es inusual y no ha sido mencionada en ella.

The hand anatomy presents general patterns in motor and sensitive nerves distribution. However, is possible to find some variations that are very important for the surgical anatomy of the region. We study 20 hands of 10 cadaver individuals, fixed in 10 percent formaldehyde solution. We found in 19 hands (95 percent) that the ulnar proper palmar digital nerve of the little finger was a direct branch of the ulnar nerve and only one case (5 percent) - of female cadaver ¡ we observed one branch originated from the forearm, which was a part in the formation of the nerve mentioned above. This branch originated from the trunk of the ulnar nerve, distal to the origin of the dorsal branch of this nerve, proximal to the pisiform bone. This nerve passed through of the abductor digiti minimi muscle and then it emerged by the superficial face of this muscle, 11,3 mm distal to its origin in the pisiform bone. Then, it joined to the ulnar proper palmar digital nerve of the little finger, distal to mentioned bone. Although the literature describes innumerous variations in the formation and distribution of the hand nerves, this disposition is rare and has not been mentioned.

Furoxan derivatives as cytotoxic agents: preliminary in vivo antitumoral activity studies.

Furoxan derivatives with in vitro cytotoxic activity were investigated as antitumoral agents in vivo. The compounds were tested in murine models of both CCRFS-180 II sarcoma and mammary adenocarcinoma. Two of the furoxan derivatives considered here, 3-formyl-4-phenyl-1,2,5-oxadiazole N2-oxide and 3-carbonitrile-4-phenyl-1,2,5-oxadiazole N2-oxide, present in vivo antitumoral activity. They were able to produce more than 90% of tumoral necrosis under the experimental protocol of administration and posology employed. NO-releasing capacity of furoxans may explain the anti-neoplastic activity of these compounds.

Monotherapy of mild hypertension with nifedipine.

The effectiveness of nifedipine as first-line monotherapy for mild diastolic hypertension (range: 95 to 105 mm Hg) was tested in this placebo-controlled, double-blind, randomized trial. Fifty-six patients were enrolled and, after titration of the placebo or active drug, they were followed for 12 weeks. Significant declines in the sitting systolic and diastolic pressures of -19 +/- 4 mm Hg (standard error) and -13 +/- 2 mm Hg, respectively, were observed during this follow-up period. Overall, 75 percent of patients receiving active drug had diastolic pressures less than or equal to 90 mm Hg at the last treatment visit. Heart rate was not significantly changed in the sitting position during the treatment period, and the majority of patients (75 percent) showed a response to nifedipine doses of 10 or 20 mg orally three times daily in the capsule form. The levels of the systolic and diastolic pressures at entry were not predictive of the dose of nifedipine required for effective blood pressure control.