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.

[Ocular paraneoplastic syndrome: cancer-associated retinopathy]

CASE REPORT

We review a patient with ocular manifestations of a paraneoplastic syndrome. It was a cancer-associated retinopathy (CAR) in a woman with visual loss, and attenuated and sheathed retinal arterioles. The electroretinography (ERG) showed severe abnormalities of the a and b-waves. The tumour process was not discovered until 6 months later, when a squamous neoplasia that invaded the uterus and vagina was observed.

DISCUSSION

Paraneoplastic syndromes are a group of manifestations produced as a remote effect of cancer cells. CAR syndrome is caused by autoimmune reactions to retinal antigens induced by aberrant expression of recoverin in cancer tissues. Ophthalmologists must be aware of ocular paraneoplastic signs as they can be the first manifestations of a malignant tumour.

Patient preferences and treatment safety for uncomplicated vulvovaginal candidiasis in primary health care

Background

Vaginitis is a common complaint in primary care. In uncomplicated candidal vaginitis, there are no differences in effectiveness between oral or vaginal treatment. Some studies describe that the preferred treatment is the oral one, but a Cochrane's review points out inconsistencies associated with the report of the preferred way that limit the use of such data. Risk factors associated with recurrent vulvovaginal candidiasis still remain controversial.

Methods/Design

This work describes a protocol of a multicentric prospective observational study with one year follow up, to describe the women's reasons and preferences to choose the way of administration (oral vs topical) in the treatment of not complicated candidal vaginitis. The number of women required is 765, they are chosen by consecutive sampling. All of whom are aged 16 and over with vaginal discharge and/or vaginal pruritus, diagnosed with not complicated vulvovaginitis in Primary Care in Madrid.

The main outcome variable is the preferences of the patients in treatment choice; secondary outcome variables are time to symptoms relief and adverse reactions and the frequency of recurrent vulvovaginitis and the risk factors. In the statistical analysis, for the main objective will be descriptive for each of the variables, bivariant analysis and multivariate analysis (logistic regression).. The dependent variable being the type of treatment chosen (oral or topical) and the independent, the variables that after bivariant analysis, have been associated to the treatment preference.

Discussion

Clinical decisions, recommendations, and practice guidelines must not only attend to the best available evidence, but also to the values and preferences of the informed patient.

Nifedipine in rat liver cirrhosis

Rat liver cirrhosis induced by CCl4+ethanol was employed to assess the effectiveness of nifedipine in reducing liver injury. Nifedipine reduced the severity of hepatocellular necrosis, significantly decreased Mallory bodies (p < 0.01), decreased polymorphonuclear inflammatory infiltrate (p < 0.05) and reduced perivenular fibrosis. Plasma lactic acid levels were significantly increased in the CCl4+ethanol group (p < 0.01). Lactacidaemia remained at normal values when the calcium antagonist blocker was employed. Nifedipine did not significantly alter the incidence of cirrhosis in this experimental model.

[Ultrastructural study of the liver from rats treated with ethanol and/or carbon tetrachloride]

The cellular ultrastructure of isolated hepatocytes and hepatic tissue in ethanol and/or carbon tetrachloride treated rats at different times. The ultrastructural modifications induced by ethanol and carbon tetrachloride, isolated administrations, are similar: Many lipidic vacuoles, several graded-injury mitochondria and R. E. R. degeneration. These effects are also induced by ethanol and carbon tetrachloride association and furthermore nuclei indentations. Some mitochondrial autophagocytosis affecting to the less electrodense hepatocytes are noted.