Actividad física, sueño y calidad de vida después de un accidente cerebrovascular durante la pandemia COVID 19

Introducción: La actividad física (AF) involucra diversos aspectos de la vida diaria y es beneficiosa para la salud, sin embargo, posterior a un accidente cerebro vascular (ACV) la AF es más baja, provocando una calidad de vida disminuida. A su vez los sujetos que realizan menos AF duermen más horas de las recomendadas, siendo un factor de riesgo para ACV. Los efectos generados por estas variables se podrían potenciar bajo el actual contexto sanitario asociado al SARS-CoV-2. Objetivo: Correlacionar la AF, horas de sueño y CVRS posteriores a un ACV. Metodología: Diseño descriptivo de corte transversal. Se midió la AF, sueño y CVRS utilizando por 7 días ActivPAL, diario casero y la escala ECVI-38 respectivamente. Resultados: La muestra conformada por 3 hombres y 3 mujeres dieron en promedio 4.519 pasos/día (DE ± 2710), realizaron 37,27 transiciones sedente- bípedo al día (DE 16,16), pasaron 7,63 horas sentado/día (DE ± 3,11), permanecieron 5,18 horas de pie/día (DE ± 3,21), estuvieron 1,17 horas caminando/día (DE ± 0,68), durmiendo 8,5 horas/ día (DE ± 1,30). Se encontró correlación negativa entre el número de pasos al día y ECVI-38. No se encontró correlación entre AF y horas sueño. Conclusión: Aumentar la AF, es fundamental para la CVRS como herramienta de prevención para el ACV y ECV. La evidencia y los hallazgos de este estudio invitan a generar consensos para clasificar la AF y considerar las horas de sueño, aspectos que están estrechamente relacionados con la salud posterior a un ACV.

Background: Physical activity (PA) involves various aspects of daily life and is beneficial for health, however, after a stroke PA is lower, causing a decreased health related quality of life (HRQOL). In turn, subjects who perform less PA sleep more hours than recommended, being a risk factor for stroke. The effects generated by these variables could be enhanced under the current health context associated with SARS-CoV-2. Objective: To correlate PA, hours of sleep and HRQOL after a stroke. Methods: Descriptive cross-sectional design. PA, sleep and HRQOL were measured using ActivPAL for 7 days, home diary and the ECVI-38 scale, respectively. Results: The sample made up of 3 men and 3 women walked 4,519 steps/day (SD ± 2710), made 37.27 seated-standing transitions per day (SD 16.16), spent 7.63 hours sitting/day (SD ± 3.11), stood 5.18 hours/day (SD ± 3.21), walked 1.17 hours/day (SD ± 0.68), slept 8.5 hours/day (SD ± 1.30). A negative correlation was found between the number of steps per day and ECVI-38. No correlation was found between PA and hours of sleep. Conclusion: Increasing PA is essential for HRQOL as a prevention tool for stroke and CVD. The evidence and findings of this study invite consensus to classify PA and consider the hours of sleep, aspects that are closely related to health after a stroke.

Elimination capacity of a TSE-model agent in the manufacturing process of Alphanate/Fanhdi, a human factor VIII/VWF complex concentrate.

The variant Creutzfeldt-Jakob disease (vCJD) is a transmissible spongiform encephalopathy (TSE), mainly present in the UK and is associated with the ingestion of bovine products affected with bovine spongiform encephalopathy. Manufacturers of biological products must investigate the ability of their production processes to remove TSE agents. We studied the purification steps in the manufacturing process of two FVIII/VWF concentrates (Alphanate) and Fanhdi in their ability to eliminate an experimental TSE-model agent. Hamster scrapie strain 263K brain-derived materials were spiked into samples of the solutions taken before various stages during its production: 3.5% polyethylene glycol (PEG) precipitation, heparin affinity chromatography and saline precipitation/final filtrations. PEG precipitation and affinity chromatography were studied both as isolated and combined steps. TSE agent removal was determined using a laboratory scale model representative of the industrial manufacturing process. The prion protein (PrP(Sc)) was measured with Western blot and TSE infectivity was measured with bioassay. Western blot results were in agreement with those obtained by bioassay, showing a significant removal capacity in the production process: 3.21-3.43 log(10) for the PEG precipitation; about 3.45 log(10) for the affinity chromatography; and around 2.0 log(10) for the saline precipitation plus final filtrations. PEG precipitation and heparin affinity chromatography were demonstrated to be two complementary TSE-model agent removal mechanisms with total removal being the sum of the two. An overall reduction factor of around 8 log(10) can be deduced. The tests from the production process of FVIII/VWF complex concentrates have demonstrated their potential for eliminating TSE agents.

Critical factors influencing prion inactivation by sodium hydroxide.

BACKGROUND AND OBJECTIVES: Transmissible spongiform encephalopathies (TSEs) are fatal neurodegenerative diseases caused by aberrantly folded cellular proteins (PrP(Sc); prions) that are generally resistant to conventional pathogen-inactivation techniques. To ensure effective decontamination and inactivation of prions that could be present in source material, we investigated critical factors that influence prion inactivation by NaOH. MATERIALS AND METHODS: A decrease in prion infectivity correlates with the disappearance of the protease-resistant core of PrPSc (PrPRES) observed in biochemical assays. To model prion inactivation, hamster scrapie (strain 263K) brain homogenate (SBH) was incubated for specific periods of time in 0.1 m NaOH at 4 or 18 degrees C, with or without detergent. Neutralized samples were subjected to limited digestion with proteinase K (PK) and then analysed using an endpoint dilution western blot assay and antibody 3F4. Structural changes in prions exposed to NaOH were examined using differential immunoprecipitation. RESULTS: Treatment of SBH with 0.1 m NaOH for 15 min, in the absence of detergent, at 4 and 18 degrees C caused a reduction in the PrP(RES) signal of 3.5 and 4.0 log10 units, respectively, with some residual signal remaining. The presence of the detergent sarkosyl during a 60-min incubation in NaOH further enhanced PrPRES reduction to > or = 4.5 log10 units (i.e. below the limit of detection). NaOH treatment induced conformational changes in PrP that resulted in the exposure of a hidden epitope and enabled prion immunoprecipitation by antibody 3F4. CONCLUSIONS: The use of NaOH can effectively reduce prion levels in an in vitro inactivation assay. After pretreatment of SBH with detergent, NaOH completely eliminates the PrPRES signal. Detergent may liberate lipid membrane-protected PrPSc to improve access to NaOH, which can then inactivate PrPSc by altering its structure. In cases of unidentified exposure to PrPSc during manufacturing, sanitizing procedures combining the use of detergent and NaOH may help to ensure minimal levels of contamination carryover in products.

Inmunofenotipificación de linfocitos en sangre periférica de pacientes chagásicos crónicos chilenos mediante citometría de flujo / Immnunophenotyping by flow cytometry of peripheral blood lymphocytes from Chilean chronic chagasic patients

Background: Cellular immune mechanisms of the resistance to infection by T cruzi as well as the pathogenesis of Chagas disease are still controversial. Aim: To quantify and analyse the peripheral blood immune cells from chagasic and non chagasic patients by flow cytometry. Patients and methods: Peripheral blood samples were taken from 21 individuals seropositive for Chagas disease, under no specific treatment. Control samples from 21 healthy blood donors were also obtained. To quantify immune cells populations by flow cytometry, antibodies against CD3, CD4, CD8, CD16/56, CD45/14, CD19 and HLA-DR markers were used. Results: The percentage of CD8+ cells was low and the CD4+/CD8+ ratio was high in chagasic patients, compared to their non infected counterparts. No statistically significant differences in the number of CD4+, NK, B, CD4+HLADR+ and CD8+HLADR+ cells, were observed within the two groups. Conclusions: These results show that Chilean chronic chagasic patients have lower percentage of CD8+ cells and higher CD4+/CD8+ ratio than non infected individuals

Activation of the interferon-inducible protein kinase PKR by hepatocellular carcinoma derived-hepatitis C virus core protein.

Hepatitis C virus (HCV) is a major etiological agent of chronic liver disease and hepatocellular carcinoma (HCC). We demonstrate herewith that HCV core proteins encoded by sequences isolated from HCC tumor tissues, but not those derived from their non-tumor counterparts in the same liver, co-localise in vitro and in vivo and co-immunoprecipitate with PKR in hepatocytic Huh7 cells. We show that this association in fact augments the autophosphorylation of PKR and the phosphorylation of the translation initiation factor eIF2alpha, which are two markers of PKR activity. The present study therefore identifies a novel model of virus-cell interactions whereby a viral protein, the HCV core, activates PKR activity.

Expression of hepatitis C virus NS5A natural mutants in a hepatocytic cell line inhibits the antiviral effect of interferon in a PKR-independent manner.

The impact of hepatitis C virus NS5A protein mutations on interferon alfa (IFN-alpha) signaling pathway, cell proliferation, and viability is an important issue that is still under debate. We have therefore combined transient and stable expression in a human hepatocytic cell line (Huh7) of 3 full-length NS5A sequences, isolated from patients with or without response to IFN-alpha therapy. Expression of all 3 NS5A-reduced IFN-alpha global antiviral activity on both vesicular stomatitis virus (VSV) and encephalomyocarditis virus (EMCV) replication. We did not show, however, an effect of these 3 NS5A proteins on double-stranded RNA-dependent kinase (PKR) expression and activity as well as colocalization and coimmunoprecipitation between NS5A and PKR. We also failed to show an effect of the 3 NS5A mutants tested on cell proliferation and viability. Overall, our results support an important role of NS5A in controlling IFN-alpha antiviral activity; they show, however, that PKR-independent mechanisms are implicated, at least in liver-derived cells.

A new continuous epitope of hepatitis A virus.

A new continuous epitope of hepatitis A virus (HAV) was defined in the VP3 protein. Convalescent sera recognised the synthetic peptide 3110-3121 (FWRGDLVFDFQV). The replacement of the arginine, glycine, or aspartic acid at positions 112, 113, or 114, respectively by other amino acids induced the loss of synthetic peptide recognition by human convalescent sera, thereby confirming the presence of an epitope in the original VP3(110-121) sequence. Shorter VP3 peptides such as VP3(110-119). VP3(110-117), and VP3(110-116) and a tandem repeat of VP3(111-116) failed to react with convalescent sera, indicating the importance of the entire peptide in the epitope structure. The maximum inhibition of human convalescent binding to HAV by the VP3(110-121) peptide was around 60%, and 50% inhibition was achieved at a peptide concentration of 2.3-2.4 micrograms/ml. Antibodies generated by this peptide bound to intact HAV and neutralised its infectivity. Antipeptide antibodies inhibited convalescent serum binding to HAV. Monoclonal antibodies H7C27 and MAK-4E7 inhibited completely binding of the antipeptide antibodies to HAV.

Hipoxemia nocturna después de cirugía abdominal: factores asociados y rol de la oxigenoterapia / Nocturnal hypoxemia after abdominal surgery: associated factors and usefulness of oxygen therapy

Fifteen elective patients (6 M, 9 F, 51+-8 years old) scheduled for laparotomy (n=8) or laparoscopy (n=7) were studied. Ventilatory parameters and pulse oximetry were measured pre and postoperatively. Patients were randomly assigned to receive oxygen by nasal cannula either during the first or the second postoperative night. PONH (Sat2 85) developed in seven patients (47 per cent)of which four had undergone laparoscopic surgery. PONH was more frequent in mildly obese patients and those presenting preoperative hypoxemia (p=0.03). Peak flow was lower in patients presenting PONH (p=0.04). In five patients, PONH was associated with significant tachycardia. Oxygen administration was associated with a higher SatO2 and prevented PONH in 6/7 patients. PONH is a common event in patients older than 40 years scheduled for open or laparascopic abdominal surgery, and develops more frequently in those with preoperative nocturnal hypoxemia and greater ventilatory impairment. PONH can be prevented, most of the time, with oxygen administration

Astrovirus survival in drinking water.

A method based on infection of CaCo-2 cultured cell monolayers (CC) and reverse transcription-PCR (RT-PCR) was developed for the specific detection of infectious astrovirus. The procedure was validated by titrating poliovirus stocks in parallel in CaCo-2 cells by determining the most probable number of cytopathogenic units and by cell culture and subsequent RT-PCR (CC-RT-PCR). CC-RT-PCR was then employed to measure the persistence of astrovirus suspended in dechlorinated tap water. After 60 days, the decay of astrovirus infectivity was 2 log units at 4 +/- 1 degrees C and 3.2 log units at 20 +/- 1 degrees C, while after 90 days, the titer reduction was 3.3 and 5 log units at 4 +/- 1 degrees C and 20 +/- 1 degrees C, respectively. Astrovirus decay in the presence of free chlorine (FC) was monitored by CC-RT-PCR. Residual infectivity was found after 2 h in the presence of 1 mg of FC/liter. Under these conditions, astrovirus shows a log titer reduction (LTR) or 4, while 0.5 mg of FC/liter induced an LTR of 2.4. The possibility of acquiring data on the survival of fastidious viruses in the environment opens new perspectives on the epidemiology of some significant infections transmitted by the fecal-oral route.

Two proline residues are essential in the calcium-binding activity of rotavirus VP7 outer capsid protein.

Rotavirus maturation and stability of the outer capsid are calcium-dependent processes. It has been shown previously that the concentration of Ca2+-solubilizing outer capsid proteins from rotavirus particles is dependent on the virus strain. This property of viral particles has been associated with the gene coding for VP7 (gene 9). In this study the correlation between VP7 and resistance to low [Ca2+] was confirmed by analyzing the origin of gene 9 from reassortant viruses prepared under the selective pressure of low [Ca2+]. After chemical mutagenesis, we selected mutant viruses of the bovine strain RF that are more resistant to low [Ca2+]. The genes coding for the VP7 proteins of these independent mutants have been sequenced. Sequence analysis confirmed that these mutants are independent and revealed that all mutant VP7 proteins have proline 75 changed to leucine and have an outer capsid that solubilized at low [Ca2+]. The mutation of proline 279 to serine is found in all but two mutants. The phenotype of mutants having a single proline change can be distinguished from the phenotype of mutants having two proline changes. Sequence analysis showed that position 75 is in a region (amino acids 65 to 78) of great variability and that proline 75 is present in most of the bovine strains. In contrast, proline 279 is in a conserved region and is conserved in all the VP7 sequences in data banks. This region is rich in oxygenated residues that are correctly allocated in the metal-coordinating positions of the Ca2+-binding EF-hand structure pattern, suggesting that this region is important in the Ca2+ binding of VP7.

Intervención del flagelo de campylobacter jejuni subsp. jejuni en la adherencia a cultivos celulares: evidencias bacteriológicas e inmunológicas / Intervention of campylobacter campylobacter jejuni subsp. jejuni flagella in the adhesion to cellular cultures: bacteriological and immunological evidences

The participation of the flagella of a virulent strain (O52) of campylobacter jejuni subsp. jejuni in the adhesion to HEp-2 cells and their inhibition by means of homologous polyclonal antibodies, moniclonal antiflagella antibodies and colostral natural antibodies (IgA) was studied. An aflagellated strain (T1) was used as negative control. Adhesion was observed in higher rates with O52 strain (72 percent) than with T1 strain (27,5 percent). Polyclonal, monoclonal and colostral antibodies inhibited O52 strain adhesion in more than 70 percent (p<0,001). T1 strain adhesion was inhibited only by polyclonal and colostral natural antibodies. Our results suggest that the flagella of C. jejuni subsp. jejuni could participate effectively in the adhesion process. However, the inhibition of T1 strain by polyclonal and colostral antibodies suggest the existence of other kinds of adhesins in the bacterial surface

Detection of infectious astroviruses in water.

Volume 62, no. 5, p. 1811, column 2, line 2: Reference "(16)" should read "(15)." Page 1812, column 1, line 17: "Willcocks and Carter (15)" should read "Willcocks et al. (14)." [This corrects the article on p. 1811 in vol. 62.].

The concentration of Ca2+ that solubilizes outer capsid proteins from rotavirus particles is dependent on the strain.

It has been previously shown that rotavirus maturation and stability of the outer capsid are calcium-dependent processes. More recently, it has been hypothesized that penetration of the cell membrane is also affected by conformational changes of the capsid induced by Ca2+. In this study, we determined quantitatively the critical concentration of calcium ion that leads to solubilization of the outer capsid proteins VP4 and VP7. Since this critical concentration is below or close to trace levels of Ca2+, we have used buffered solutions based on ethylene glycol-bis(beta-aminoethyl ether)-N,N,N',N'-tetraacetic acid (EGTA) and Ca-EGTA. This method allowed us to show a very high variability of the free [Ca2+] needed to stabilize, at room temperature, the outer capsid of several rotavirus strains. This concentration is about 600 nM for the two bovine strains tested (RF and UK), 100 nM for the porcine strain OSU, and only 10 to 20 nM for the simian strain SA11. Titration of viral infectivity after incubation in buffer of defined [Ca2+] confirmed that the loss of infectivity occurs at different [Ca2+] for these three strains. For the bovine strain, the cleavage of VP4 by trypsin has no significant effect on the [Ca2+] that solubilizes outer shell proteins. The outer layer (VP7) of virus-like particles (VLP) made of recombinant proteins VP2, VP6, and VP7 (VLP2/6/7) was also solubilized by lowering the [Ca2+]. The critical concentration of Ca2+ needed to solubilize VP7 from VLP2/6/7 made of protein from the bovine strain is close to the concentration needed for the corresponding virus. Genetic analysis of this phenotype in a set of reassortant viruses from two parental strains having the phenotypes of strains OSU (porcine) and UK (bovine) confirmed that this property of viral particles is probably associated with the gene coding for VP7. The analysis of VLP by reverse genetics might allow the identification of the region(s) essential for calcium binding.

Monitorización intraoperatoria del pH intramucoso gástrico / Intrasurgical monitorization of the gastric intramucosal pH

Eighteen patients subjected to abdominal surgery were studied. All received general anesthesia and hemodynamic parameters were maintained within 20 percent of basal values. A tononeter was placed in the stomach after induction of anesthesia. Arterial blood gases and samples from the tonometer were obtained 30 minutes after induction and at 2 hours of surgery. Intramucosal pH was calculated using Henderson-Haselbach equations. Basal gastric mucosal pH was 7.4ñ0.1 and did not change during surgery. Two patients had a pH persistently below 7.35 without hemodynamic alterations or systemic acidosis. Gastric mucosal pH is not modified by abdominal surgery and some patients have low values despite the absence of hemodynamic derangement

Detection of infectious astroviruses in water.

A method based on the infection of CaCo-2 cells and molecular hybridization with a specific cDNA probe has been developed for the detection of infectious astroviruses in environmental samples. By this procedure wild-type astroviruses have been detected in water from an area where a concurrent gastroenteritis outbreak was reported.

Non isotopic automatable molecular procedures for the detection of enteroviruses.

Five microwell non isotopic hybridization assays, based on colorimetric immunoenzymatic reading, were developed and evaluated for the rapid and automatable detection of enteroviruses. Virus nucleic acids and/or capture probes were covalently bound to microtiter wells, and digoxigenin-11-dUTP was used as label for the detection of hybridized material. Among these procedures, a reverse transcriptase polymerase chain reaction (RT-PCR) hybridization assay was the most sensitive, enabling the detection of 10 MPNCU of poliovirus, and offering detection specificity for other enteroviruses, such as coxsackieviruses and echoviruses. The second most sensitive method was a complementary hybridization assay, simultaneously using three detection probes, one from the 5' end and two from the 3' end of poliovirus genome, offering a sensitivity for poliovirus detection of 5 x 10(3) MPNCU.

Anestesia peridural continua en pediatría / Continous peridural anesthesia in pediatrics

Se realizó una anestesia peridural continua en 51 pacientes, que tenían entre 20 días y 13 años de edad, sometidos a cirugía abdominal u ortopédica. En un paciente no se pudo ubicar el espacio peridural y en otro no se pudo avanzar el catéter. En los restantes no se presentaron problemas derivados del procedimiento. La mantención se hizo con halogenados en concentraciones menorea a ! mAC y fentanyl 2-4 µg/kg como dosis total, con lo que se obtuvieron muy buenas condiciones de analgesia intraoperatoria. El catéter se usó para analgesia en el postoperatorio, administrándose 0,2 ml/kg de bupivacaína 0,2 por ciento o 30-70 µg/kg de morfina. En 29 casos no fue necesario otro tipo de analgesia. No hubo complicaciones atribuíbles a la analgesia peridural postoperatoria

Genotyping of rotaviruses isolated from sewage.

Rotaviruses from environmental samples have been genotyped by a seminested reverse transcription PCR assay with serotype-specific primers derived from variable regions of gene 9, which produce different characteristic segment sizes for serotypes 1 to 4. The method enabled the detection and identification of type 1, 2, and 3 group A rotaviruses in sewage.