Tau reduction with artificial microRNAs modulates neuronal physiology and improves tauopathy phenotypes in mice.

Abnormal tau accumulation is the hallmark of several neurodegenerative diseases, named tauopathies. Strategies aimed at reducing tau in the brain are promising therapeutic interventions, yet more precise therapies would require targeting specific nuclei and neuronal subpopulations affected by disease while avoiding global reduction of physiological tau. Here, we developed artificial microRNAs directed against the human MAPT mRNA to dwindle tau protein by engaging the endogenous RNA interference pathway. In human differentiated neurons in culture, microRNA-mediated tau reduction diminished neuronal firing without affecting neuronal morphology or impairing axonal transport. In the htau mouse model of tauopathy, we locally expressed artificial microRNAs in the prefrontal cortex (PFC), an area particularly vulnerable to initiating tau pathology in this model. Tau knockdown prevented the accumulation of insoluble and hyperphosphorylated tau, modulated firing activity of putative pyramidal neurons, and improved glucose uptake in the PFC. Moreover, such tau reduction prevented cognitive decline in aged htau mice. Our results suggest target engagement of designed tau-microRNAs to effectively reduce tau pathology, providing a proof of concept for a potential therapeutic approach based on local tau knockdown to rescue tauopathy-related phenotypes.

Impact of antagonistic yeasts from wine grapes on growth and mycotoxin production by Alternaria alternata.

AIMS: Alternaria alternata is a major contaminant of wine grapes, meaning a health risk for wine consumers due to the accumulation of toxic metabolites. To develop a successful biofungicide, the effectiveness of epiphytic wine grape yeasts against A. alternata growth and toxin production was assessed in vitro under temperature and aW conditions that simulate those present in the field. METHODS AND RESULTS: The effect of 14 antagonistic yeasts was evaluated on growth and alternariol (AOH), alternariol monomethyl ether (AME) and tenuazonic acid (TA) production by three A. alternata strains in a synthetic medium with composition similar to grape (SN) at three temperatures (15, 25 and 30°C). All Metschnikowia sp. yeast strains evaluated completely prevented A. alternata growth and mycotoxin production at all temperatures in SN medium. Meanwhile, the growth inhibition exerted by Starmerella bacillaris yeast strains was higher at 30°C, followed by 25 and 15°C, being able to show a stimulating or inhibiting effect. Hanseniaspora uvarum yeast strains showed a growth promoting activity higher at 15°C, followed by 25 and 30°C. Even at conditions where A. alternata growth was stimulated by the S. bacillaris and H. uvarum yeasts, high inhibitions of mycotoxin production (AOH, AME and TA) were observed, indicating a complex interaction between growth and mycotoxin production. CONCLUSION: There is a significant influence of temperature on the effectiveness of biocontrol against A. alternata growth and mycotoxin production. Metschnikowia sp. strains are good candidates to compose a biofungicide against A. alternata. SIGNIFICANCE AND IMPACT OF THE STUDY: Among the different antagonistic yeasts evaluated, only Metschnikowia sp. strains were equally effective reducing A. alternata growth and mycotoxin at different temperatures underlining the importance of considering environmental factors in the selection of the antagonists.

Water activity and temperature effects on growth and mycotoxin production by Alternaria alternata strains isolated from Malbec wine grapes.

AIMS: To study the effects of water activity (aW ; 0·99, 0·98, 0·97, 0·96 and 0·95), temperature (15, 25 and 30°C), incubation time (7-28 days), and their interactions on mycelial growth and alternariol (AOH), alternariol monomethyl ether (AME) and tenuazonic acid (TA) mycotoxin production on a synthetic nutrient (SN) media similar to grape composition by three strains of Alternaria alternata isolated from wine grapes from Argentina. METHODS AND RESULTS: Interacting conditions of aW , temperature and time of incubation were used to examine growth and mycotoxin production. All strains were able to grow at 0·95 aW , but maximum growth rates were obtained at 0·99 aW and 25°C. Maximum levels of AOH, AME and TA were obtained at 0·99 aW and 25°C, but high amounts of TA were also obtained at 0·96 aW and 15 or 30°C. Production of AOH and AME was favoured over TA at 25°C. TA levels were more sustained than AOH and AME. CONCLUSION: The optimum and marginal conditions for growth and mycotoxin production by A. alternata on a SN media similar to grape composition were in agreement, but certain stressful conditions for growth evaluated also promote mycotoxin production. SIGNIFICANCE AND IMPACT OF THE STUDY: Temperature and aW conditions that allows growth and mycotoxin production are those normally found during wine grape ripeness in the field. Therefore, efforts should be made to prevent Alternaria presence and mycotoxin production in wine grapes.

[Euglycemic ketosis in an adolescent with type 1 diabetes on insulin and dapaglifozin: Case report]. / Cetosis normoglicémica en adolescente con diabetes tipo 1 recibiendo insulina y dapaglifozina: Reporte de un caso.

Dapagliflozin, an insulin-independent sodium-glucose cotransporter 2 inhibitor (SGLT2-I) induces glycosuria and reduces hyperglycemia in adults with type 2 diabetes. OBJECTIVE: To present an “euglycemic” diabetic ketosis in an adolescent with type 1 diabetes (T1D) receiving dapagliflozin, to alert about the risk of a drug not approved in children nor in T1D. CASE REPORT: A 17 years old adolescent with T1D during 9 years, was started on dapagliflozin 10 mg / day to reduce insulin dose and weight. During 11 months on treatment, capillaries ketones were undetectable and she exhibited a reduction in body mass index 23.9 to 21.1 kg/m2, basal insulin 40 to 17 U, glycated hemoglobin 8.3 to 7.5%, capillary glucose 175 to 161 mg/dl and glucose variability (standard deviation) 85 to 77. Suddenly nausea and vomits appeared. The patient was on an insulin pump and well calibrated continuous glucose monitoring, showing stable glucose levels under 200 mg/dl, and an insulin bolus was delivered. Vomiting without hyperglycemia persisted; three hours later, she was severely dehydrated and fainting, with ketones 4.6 nmol/l and glucose 224 mg/dl. She received IV saline fluids, ondansetron, carbohydrates and several insulin boluses. Hydration and general condition improved soon, however despite several insulin doses, ketosis continued for 24 hours. It is remarkable that the pump was working well and the cannula was not changed. After the ketosis was resolved, she continued using the same cannula with good metabolic control. CONCLUSION: Euglycemic ketosis is a life-threatening condition that must be suspected.

Information capacity and robustness of encoding in the medial prefrontal cortex are modulated by the bioavailability of serotonin and the time elapsed from the cue during a reward-driven task.

Serotonin (5-HT) is a key neuromodulator of medial prefrontal cortex (mPFC) functions. Pharmacological manipulation of systemic 5-HT bioavailability alters the electrical activity of mPFC neurons. However, 5-HT modulation at the population level is not well characterized. In the present study, we made single neuron extracellular recordings in the mPFC of rats performing an operant conditioning task, and analyzed the effect of systemic administration of fluoxetine (a selective serotonin reuptake inhibitor) on the information encoded in the firing activity of the neural population. Chronic (longer than 15 days), but not acute (less than 15 days), fluoxetine administration reduced the firing rate of mPFC neurons. Moreover, fluoxetine treatment enhanced pairwise entropy but diminished noise correlation and redundancy in the information encoded, thus showing how mPFC differentially encodes information as a function of 5-HT bioavailability. Information about the occurrence of the reward-predictive stimulus was maximized during reward consumption, around 3 to 4 s after the presentation of the cue, and it was higher under chronic fluoxetine treatment. However, the encoded information was less robust to noise corruption when compared to control conditions.

Serotonergic modulation of basolateral amygdala nucleus in the extinction of reward-driven learning: The role of 5-HT bioavailability and 5-HT1A receptor.

Serotonin (5-HT) neurotransmission has been associated with reward-related behaviour. Moreover, the serotonergic system modulates the basolateral amygdala (BLA), a structure involved in reward encoding, and reward prediction error. However, the role played by 5-HT on BLA during a reward-driven task has not been fully elucidated. In this paper, we investigated whether serotonergic modulation of the BLA is involved in reward-driven learning. To this end, we trained Long Evans rats in an operant conditioning task, and examined the effects of fluoxetine treatment (a selective serotonin reuptake inhibitor, 10 mg/kg) in combination with BLA lesions with NMDA (20 mg/mL) on extinction learning. We also investigated whether intra-BLA injection of the serotonergic 5-HT1A receptor agonist 8-OH DPAT, or antagonist WAY-100635, alters extinction performance. We found that fluoxetine treatment strongly accelerated extinction learning, while BLA lesions partially reverted this effect and slightly impaired consolidation of extinction. Stimulation and inhibition of 5-HT1A receptors in BLA induced opposite effects to those of fluoxetine, impairing or accelerating extinction performance, respectively. Our findings suggest that 5-HT modulates reward-driven learning, and 5-HT1A receptors located in the BLA are relevant for extinction.

Pubourethral supports in perspective: modified pereyra procedure for urinary incontinence.

The present study supports the thesis that failures in urethral suspensory-type operations in women with anatomic stress urinary incontinence often are caused by pull-out of suspensory sutures attached to attenuated endopelvic fascia around the urethrovesical junction. Thickening of this fascia helps impede suture pull-out. Such thickening is facilitated by detaching the fascia from the pubis to enfold it. Freeing the fascia from the inferior pubis exposes the posterior pubourethral ligaments to direct view. Binding the much stronger posterior pubourethral ligaments and enfolded fascia together with the suspensory sutures provides maximum resistance to suture pull-out. Of 54 women treated with this modified Pereyra procedure as a primary operation for anatomic stress urinary incontinence, 94.5% showed complete cure or marked improvement 4 to 6 years postoperatively.

Quantification of lectin in freshwater prawn (Macrobrachium rosenbergii ) hemolymph by ELISA.

An enzyme-linked immunoabsorbent assay was developed to quantify the lectin present in the hemolymph of the freshwater prawn Macrobrachium rosenbergii. This method involves the use of murine monoclonal IgG1 with kappa light chain (designated as 3G1) antibodies raised against the purified lectin, the assay that we developed recognized as little as 30 ng/ml of lectin, and was used to measure the lectin concentration in animals at different maturation stages. The highest concentration of lectin was identified in the hemolymph from post-larval prawns and the lowest in molt stage adult animals. The hemagglutination activity of the lectin was four-fold higher in adult than in juvenile specimens, although in all cases N-acetylated sugar residues, such as N-acetyl-D-glucosamine, N-acetyl-D-galactosamine, and N-acetyl-D-neuraminic acid were inhibitors of the lectin activity, suggesting that lectin plays a role in the transport of N-acetylated sugar in juvenile prawns. Our results indicate that lectin concentration and hemagglutinating activity could be influenced by developmental conditions of the freshwater prawn.

Chemical characterization of the lectin from the freshwater prawn Macrobrachium rosenbergii (De Man) by MALDI-TOF.

The serum of the freshwater prawn contains a sialic acid specific lectin (MrL) that agglutinates erythrocytes from rat and rabbit, as well as some Gram negative and positive bacterial strains. In this work, we performed the chemical characterization of the MrL purified by affinity chromatography on stroma from rat erythrocytes and by ion exchange chromatography. In its active form, MRL is a dimeric glycoprotein with 9.5 kDa per subunit. The amino acid sequence of the lectin was deduced from peptides obtained after trypsin treatment by matrix-assisted laser desorption ionization mass spectrometry-time of flight analysis (MALDI-TOF). The predicted amino acid sequence of the lectin showed 54% homology with the hyperglycemic hormone from Macrobrachium rosenbergii. It also showed homology with the variable region of the human immunoglobulin kappa (22%) and lambda (27%) light chains. The lectin is a glycoprotein with 11% (w/w) carbohydrate content and is constituted by Gal, Man, GlcNAc, GalNAc and NeuAc in a molar ratio of 4:3:2:1:0.6. The primary structure of the carbohydrate chains of the lectin from the freshwater prawn was determined by affinity chromatography of MrL-glycopeptides on Con A and LCA lectin columns, which indicated that the main carbohydrate chains conforming the lectin are N-glycosidically linked. Man3 GlcNAc2.1 oligosaccharides were the most abundant structures with 57%) followed by Gal1.3 Man3 GlcNAc2.8 with 24%. Our results suggest that the freshwater prawn possess a lectin in the hemolymph plasma, related to those from the immunoglobulin superfamily.

[The intracellular increase of ionized calcium depends on factors present in the blood of patient with preeclampsia]. / El aumento del calcio ionizado intracelular depende de algún factor presente en el suero de las pacientes preeclámpticas.

In previous works our group has demonstrated that intracellular concentration of calcium ionized is greater in patients with pre-eclampsia than in normotense pregnant patients, and that these figures correlate with arterial pressure. Both indicators become normal six weeks after delivery. With the idea of searching the possible participation of soluble factors in the plasma, in increasing free, intracellular calcium, eight pre-eclamptic patients, were studied; the patients were diagnosed by the criteria of the American College of Gynecologists and Obstetricians. As a control group, eight normotense pregnant patients, were included; they were paired by age, chronological and gestational. To measure transmembrane calcium flow, platelets from healthy males, were used. The platelets were incubated during 0, 15, 30 and 60 minutes in sera of pre-eclamptic patients, or of normotensive pregnant patients, marked with Ca. The differences in calcium transportation, were evaluated with variance analysis of Kruskall Wallis. Calcium transportation was greater when the platelets were incubated in pre-eclamptic patients sera, Md = 1.475 +/- 0.311 nanomoles than when were incubated in normotensive women sera, Md = 0.9725 +/- 0.58 nanomoles, p < 0.02. This finding suggests that in pre-eclamptic patients serum, exists some factor that facilitates the entrance of calcium to the cell, that provokes an increase in free calcium concentration, and it participates in the gestational hypertension.

[Importance of free intracellular calcium in the physiopathology of pre-eclampsia]. / Importancia del calcio libre intracelular en la fisiopatología de la preeclampsia.

Due to the participation of intracellular free calcium in the mechanisms of vascular smooth muscle contraction, and its importance in the physiopathology of essential arterial hypertension, its possible role in pre-eclampsia physiopathology, was investigated as a cellular model, platelets, were use, as they are similar to vascular smooth muscle cells. The study purpose was to investigate if intracellular concentration of ionized calcium is greater in the patients with pre-eclampsia than in normotensive pregnant women, and also, if there exists a correlation between intracellular calcium concentrations and arterial tension, Seven pre-eclamptic patients, diagnosed by the following criteria: arterial tension greater than or equal to 130/90 mmHg, edema and proteinuria, between 20 to 35 years of age, during the third trimester of gestation, without personal nor family antecedents of hypertension; none of them received treatment at the time, were studied. As control group seven normotensive pregnant women, equal by chronologic and gestational age, were included. Intracellular calcium in platelets was measured by Fluo-3-Am, and arterial blood pressure with conventional sphygmomanometer. Intracellular calcium and arterial blood pressure values, were compared, in both groups by Student's t, and analysis of lineal regression between intracellular calcium and mean arterial blood pressure, was done. Intracellular calcium was significantly greater in patients with pre-eclampsia, than the ones in the control group (142 +/- 5.6 vs 110 +/- 14 p less than 0.0001). Mean arterial blood pressure was also significantly greater in patients with pre-eclampsia (114 +/- 5 vs 83 +/- 3 p less than 0.0001).(ABSTRACT TRUNCATED AT 250 WORDS)

[Auto- and allolymphocytoxins in psoriasis]. / Auto y alolinfocitotoxinas en psoriasis.

The authors study the auto, alolymphocytotoxins and E rosettes, in 40 patients with active psoriasis. The results show a decrease in the average of T lymphocytes which form E rosettes. It was not possible to render evident the auto or alolymphocytotoxins. This indicates that there are not antilymphocytics antibodies in psoriasis, which makes it possible to eliminate them as responsible for the inhibiting factors in rosettes formation by the lymphocyte.

Cetosis normoglicémica en adolescente con diabetes tipo 1 recibiendo insulina y dapaglifozina: Reporte de un caso / Euglycemic ketosis in an adolescent with type 1 diabetes on insulin and dapaglifozin: Case report

Dapaglifozina, un inhibidor del cotransportador de sodio-glucosa 2 (I-SGLT2) induce glucosuria y reduce la glicemia en adultos con diabetes tipo 2. Objetivo: Presentar una cetosis diabética “normoglicémica” en una adolescente con diabetes tipo 1 (DM1) que recibía dapaglifozina y alertar sobre el riesgo del uso I-SGLT2 que parece promisorio, pero no está aprobado en niños ni en DM1. Caso clínico: Paciente de 17 años sin cetosis durante 9 años con DM1, inició dapaglifozina 10 mg/día para reducir la insulina y el peso. Durante 11 meses de tratamiento tuvo cetonas capilares indetectables, redujo el índice de masa corporal 23,9 a 21,1 kg/m², la insulina basal 40 a 17 U, la hemoglobina glicosilada 8,3 a 7,5%, la glicemia capilar 175 a 161 mg/dl y la variabilidad de la glucosa (desvío estándar 85 a 77). Inesperadamente aparecieron náuseas y vómitos. La paciente portaba bomba de insulina con monitorización continua de glucosa, bien calibrada (glucosas intersticiales concordantes con glicemias), que mostraba glucosa estable bajo 200 mg/dl. Recibió insulina pero los vómitos persistieron; en tres horas, aparecieron deshidratación y desmayos, con cetonas 4,6 nmol/l y glicemia 224 mg/dl. Recibió suero fisiológico, ondansetrón, carbohidratos y varias dosis de insulina con pronta recuperación del estado general e hidratación, sin embargo, la cetosis continuó durante 24 horas. Cabe destacar que la bomba estaba funcionando bien y no se cambió la cánula. Al superar la cetosis, continuó con la misma cánula con buen control metabólico. Conclusión: Es importante sospechar la cetosis diabética normoglicémica por ser de riesgo vital.

Dapagliflozin, an insulin-independent sodium-glucose cotransporter 2 inhibitor (SGLT2-I) induces glycosuria and reduces hyperglycemia in adults with type 2 diabetes. Objective: To present an “euglycemic” diabetic ketosis in an adolescent with type 1 diabetes (T1D) receiving dapagliflozin, to alert about the risk of a drug not approved in children nor in T1D. Case report: A 17 years old adolescent with T1D during 9 years, was started on dapagliflozin 10 mg / day to reduce insulin dose and weight. During 11 months on treatment, capillaries ketones were undetectable and she exhibited a reduction in body mass index 23.9 to 21.1 kg/m2, basal insulin 40 to 17 U, glycated hemoglobin 8.3 to 7.5%, capillary glucose 175 to 161 mg/dl and glucose variability (standard deviation) 85 to 77. Suddenly nausea and vomits appeared. The patient was on an insulin pump and well calibrated continuous glucose monitoring, showing stable glucose levels under 200 mg/dl, and an insulin bolus was delivered. Vomiting without hyperglycemia persisted; three hours later, she was severely dehydrated and fainting, with ketones 4.6 nmol/l and glucose 224 mg/dl. She received IV saline fluids, ondansetron, carbohydrates and several insulin boluses. Hydration and general condition improved soon, however despite several insulin doses, ketosis continued for 24 hours. It is remarkable that the pump was working well and the cannula was not changed. After the ketosis was resolved, she continued using the same cannula with good metabolic control. Conclusion: Euglycemic ketosis is a life-threatening condition that must be suspected.

Risk evaluation of nonvaccinated, weaned calves transported through areas under systematic foot and mouth disease (FMD) vaccination.

The recurrence and persistence of foot and mouth disease (FMD) could be the consequence of cyclic and massive transportation of calves. For this reason, in South America, vaccination strategies related to livestock dynamic are being promoted. In order to aid the evaluation of such strategies, a method for predicting the risk of transportation of nonvaccinated weaned calves was developed; this method combines expert opinion and empirical evidence using Bayesian estimators. It was applied through Monte Carlo simulation to data of Argentina under four hypothetical vaccination schemes: E1, extended vaccination season of 1/6 of the population of calves each month from July to December without second round vaccination (SRV); E2, extended irregular vaccination from July to December with SRV applied to 70% of the calves resembling the scheme applied in Argentina in 2001; E3, vaccination in November and December without SRV; and E4, vaccination concentrated in November. E1 resulted in probability of transporting non vaccinated calves (tnvc) reaching its maximum in the following year in May with mean=0.0250 and percentile 95% (P95)=0.0404; for the same month tnvc estimates for the other schemes were E2: mean=0.0071; P95=0.0162; E3: mean=0.0017; P95=0.0042 and E4: mean=0.0001; P95=0.0004. Bonferroni multiple comparison for simultaneous assertions for May showed that E4 resulted the best scheme, E1 the worst, and E2 and E3 are intermediate with nonsignificant difference observed between overall (p<0.05). Results were consistent with historical records and quantification for future needs for re-vaccination was made possible. While the ratio "total vaccinated"/"total estimated existences" will give a biased vision of vaccination coverage under the situation of extended vaccination campaigns, a model as the one developed here could allow a more accurate assessment and the design of mitigation plans.

A graphic guide for clinical management of latent syphilis.

A graphic luetic record form is used as a guide to physicians in diagnosis and management of latent syphilis. The form provides a uniform method of recording laboratory and clinical findings as well as treatment. It facilitates checking progress and forwarding of information necessary to assure continuity in treatment of patients with latent syphilis who are transferred to other medical facilities. It is designed primarily as a guide to the clinician who does not specialize in the treatment of syphilis.

[A new milk formula: iron bioavailability and effect on prevention of iron deficiency in infants]. / Nueva fórmula láctea: biodisponibilidad del hierro y efecto en la prevención de su deficiencia en lactantes.

Iron bioavailability from a modified cow milk, formula (LPM) (which included additional iron as 5 mg/l ferrous sulfate and ascorbic acid, 50 mg/l) was examined in 11 adult women using the extrinsic radioactive tag method. The geometric mean absorption from LPM was 13% (reference dose absorption = 26%). The effect of this formula on iron nutrition of infants was studied in 43 healthy term infants weaned spontaneously before 3 months of age which were given LPM until 9 months of age. Another 45 infants (controls) were fed full fat, non fortified powdered cow's milk (LP) as delivered through the National Complementary Food Program (PNAC-Chile) and additional 45 infants were given fortified a cow's milk formula (LF) with ferrous sulfate (iron: 15 mg/l and ascorbic acid: 100 mg/l). Solid foods (vegetables and meat) were introduced to all these babies from age 4 months. At 9 months of age 4% infants fed LPM had evidence of anemia vs. 2% and 20% of infants given LF and LP formulae respectively. This results suggests that LPM is effective in preventing iron deficiency anemia in infants.

[The platelet response as a prognostic factor in invasive amebiasis of the liver]. / La respuesta plaquetaria como factor pronóstico en la amibiasis invasora del hígado.

A group of 96 patients with Invasive Hepatic Amebiasis, was studied in a prospective clinical trial. The platelet count was measured for each patient on admission and on the tenth day of treatment. The patient were classified into two groups: the first one for patients with unfavorable results and the second one for patients with favorable results. The presence of thrombocytosis was significant in the second group, with a sensitivity of 56% and specificity of 70% in the initial determination, and of 82% and 68% at the tenth day respectively. With this finding, it could be considered that thrombocytosis must be a good prognostic indicators in the Amebic Liver Abscess, and it could be possible to include it in a scale to elucidate the prognosis in a quantitative form, of this pathologic entity.