Physical activity level and factors associated with perceived stress among Peruvian university professors during the COVID-19 pandemic.

Introduction: The COVID-19 pandemic led to the transition to remote work, triggering variations in stress and physical activity (PA), associated with context-specific instability. Objective: To identify the association between perceived stress (PS) and the level of physical activity (PA) and explore its relationship with the sociodemographic, family, work and individual characteristics of professors working remotely during the COVID-19 pandemic. Material and methods: Cross-sectional analytical study based on a virtual survey of professors. PS was assessed using the Perceived Stress Scale (PSS-14), and PA using an International Physical Activity Questionnaire. The prevalence of high PS and the association with PA were estimated using a Poisson regression analysis with robust variance that estimated crude prevalence ratios (cPR) and adjusted prevalence ratios (aPR) with a 95% confidence interval (CI). Five models were developed to assess associations of PS and PA with sociodemographic, family, work, and individual variables. Results: The information of 191 professors was analyzed; 39.27% were women, aged 52 (41-60). The prevalence of high stress was 47.12%. The age and being head of household did not show significant individual associations with PS. However, the regression analysis assessing the association of PS and other factors showed that compared to the moderate PA group, a statistically significant association was found between stress and high PA (aPR = 0.19; 0.06-0.59), low PA (aPR = 1.43; 1.02-2.01), mainly influenced by age, being head of household and sleep quality. Conclusion: Stress was associated with PA level, family and individual factors. These findings allow identifying characteristics, such as being head of household, age and quality of sleep among teachers, as being associated with a higher probability of having high stress. Subsequent studies should consider the role of individuals and working conditions as part of occupational health surveillance, given the presence of hybrid education in the education sector.

La prueba de tuberculina positiva no es sinónimo de tuberculosis latente / The positive tuberculin test is not synonymous with latent tuberculosis

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El vino tinto es algo más que una bebida alcohólica / Red wine is more than just an alcoholic beverage

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Analysis of tissue bioimpedance as a measurement of liver steatosis: experimental model in large animals.

BACKGROUND: Electrical bioimpedance (BI) has been used to indirectly measure steatosis. This method has not yet been established in the clinics thus experimental studies are needed in big animals. We assessed BI to measure liver steatosis in porcine animals. METHODS: Twelve large-white × Landrace pigs weighing 35 kg were allocated to a study (n = 9) and a control group (n = 3). A special diet was used to promote steatosis among the study group: methionine deficient and choline-restricted diet that contains supplements of cholesterol, collate and excess of saturated fat. Control group animals were fed a normal diet. A new tetrapolar electrode model was used for BI measurement, which were performed during open laparotomy by inserting a probe into one of the lobes. Measurements were done in the third and fourth segments of the pig liver, placing the probe either on the surface or inserted into the parenchyma of the liver. Open biopsies were obtained at the end of the measurements. Histological samples were processed and stained with hematoxylin-eosin to estimate macrosteatosis. Pearson correlation coefficient between BI and percentage steatosis were calculated at different frequencies. RESULTS: After 4 months of the special diet all the animals in the study group developed steatosis (90% to 20%), whereas none of the control group was affected. Pearson correlation coefficients between BI and percentage of steatosis were significant (0.877-0.878) with the best correlations obtained with a probe placed on the fourth segment of the liver surface and the best frequency to perform the measurements being 50 and 75 kHz. CONCLUSIONS: BI is an accurate, fast method for steatosis measurements, that is easier and cheaper than either open or needle biopsy.

Platelet indices in SGA newborns.

PURPOSE: The current study objective was to compare blood platelet indices in full-term small-for-gestational-age newborns (SGA) and full-term appropriate-for-gestational-age newborns (AGA). MATERIALS/METHODS: We introduced to our study 61 SGA newborns (31 females and 30 males) and 70 eutrophic infants (32 females and 38 males). The SGA newborns were divided into two groups: those weighing less than the 5th centile: 35 infants (16 females and 19 males) and those between the 5th and 10th centiles: 26 infants (15 females and 11 males). Platelet indices were estimated in blood samples collected from the umbilical artery. RESULTS: SGA demonstrated a decreased count of blood platelets (238×103/µ) as compared with AGA (286×103/µL), p=0.0001. Platelet hematocrit (PTC) also showed differences in both groups (SGA=0.19% vs. AGA=0.22%; p=0.0005). Mean platelet volume (MPV) was higher in SGA (8.25fl) as compared with AGA (7.84fl); p=0.008. Large platelet count (LPLT) was higher in AGA 6.26% vs. SGA=4.75%; p=0.01. Platelet distribution width (PDW) was found to be nearly the same (SGA=47%, AGA=46%). PDW was higher in SGA newborns < 5th centile (43%) as compared with SGA infants between the 5th and 10th centiles (52%); p=0.008. CONCLUSIONS: A decreased blood platelet count, platelet hematocrit and large metabolically active platelet count, which in addition to reduced synthesis and excessive consumption of coagulation factors in states of hiperclotting is characteristic of IUGR, enhances the possibility of bleeding complications and increases the risk of infections. From a clinical point of view, it is important to take into consideration the degree of intrauterine hypotrophy during the evaluation of hemostatic disorders.

Latitudinal prevalence gradient of multiple sclerosis in Latin America.

BACKGROUND: Multiple sclerosis (MS) has a unique geographical distribution that reflects both genetic and environmental factors. Many studies have shown a positive correlation between MS frequency and latitude across both large and small geographical regions. However, scarce data have been published on the epidemiology of MS in Latin America and no study has evaluated latitudinal variation. OBJECTIVE: To evaluate the effect of latitude on MS prevalence in Latin America. METHODS: We conducted a systematic review of MS prevalence during January 2011. Prevalence rates were collected from eligible publications. The effect of latitude on prevalence was analyzed using linear regression. RESULTS: A total of ten studies were eligible for analysis, corresponding to six countries, spanning from Panama to Argentina. The crude prevalence of MS ranged from 0.75 to 21.5 per 100,000. We found a strong and significant association between prevalence and latitude (r(2) 0.8; p < 0.001) and determined an increase in prevalence of 0.33 per 100,000 per degree latitude. CONCLUSION: Our findings suggest a latitudinal prevalence gradient of MS in Latin American countries between Panama and Argentina.

Expression of Fas receptor on human T lymphocytes under stimulation with Borrelia burgdorferi sensu lato - preliminary results.

PURPOSE: Apoptosis of activated T lymphocytes is essential to immunoregulation and its abnormalities have been observed in immune system disorders and persistent infections. To asses Borrelia burgdorferi influence on the susceptibility of T lymphocytes to apoptosis, we have measured expression of the Fas death receptor on these cells after incubation with live B. burgdorferi. MATERIAL AND METHODS: Peripheral blood mononuclear cells from 23 LD patients (18 with Lyme arthritis, 5 with neuroborreliosis) and 13 healthy controls (C) were incubated for 48 hours with and without live B. burgdorferi spirochetes: B. afzelii, B. garinii or B. burgdorferi sensu stricto. After incubation, Fas expression on CD3+ cells was measured cytometrically with FITC-labeled monoclonal antibody. RESULTS: Median fraction of Fas-expressing T lymphocytes increased under incubation with B. burgdorferi, with more cells expressing Fas after incubation with B. burgdorferi sensu stricto than with B. garinii. There was a tendency for a higher expression of Fas on T lymphocytes from LD patients then from controls, both in unstimulated and B. burgdorferi-stimulated cultures, but it did not reach a level of statistical significance. CONCLUSIONS: B. burgdorferi seems to increase Fas expression on CD3+ T lymphocytes, which may render these cells more susceptible to apoptosis. This effect is stronger for B. burgdorferi s.s. than for B. garinii genospecies.

Olive oil and health: summary of the II international conference on olive oil and health consensus report, Jaén and Córdoba (Spain) 2008.

Olive oil (OO) is the most representative food of the traditional Mediterranean Diet (MedDiet). Increasing evidence suggests that monounsaturated fatty acids (MUFA) as a nutrient, OO as a food, and the MedDiet as a food pattern are associated with a decreased risk of cardiovascular disease, obesity, metabolic syndrome, type 2 diabetes and hypertension. A MedDiet rich in OO and OO per se has been shown to improve cardiovascular risk factors, such as lipid profiles, blood pressure, postprandial hyperlipidemia, endothelial dysfunction, oxidative stress, and antithrombotic profiles. Some of these beneficial effects can be attributed to the OO minor components. Therefore, the definition of the MedDiet should include OO. Phenolic compounds in OO have shown antioxidant and anti-inflammatory properties, prevent lipoperoxidation, induce favorable changes of lipid profile, improve endothelial function, and disclose antithrombotic properties. Observational studies from Mediterranean cohorts have suggested that dietary MUFA may be protective against age-related cognitive decline and Alzheimer's disease. Recent studies consistently support the concept that the OO-rich MedDiet is compatible with healthier aging and increased longevity. In countries where the population adheres to the MedDiet, such as Spain, Greece and Italy, and OO is the principal source of fat, rates of cancer incidence are lower than in northern European countries. Experimental and human cellular studies have provided new evidence on the potential protective effect of OO on cancer. Furthermore, results of case-control and cohort studies suggest that MUFA intake including OO is associated with a reduction in cancer risk (mainly breast, colorectal and prostate cancers).

Platelet activation in patients with advanced gastric cancer.

The aim of this study was to evaluate platelet activation in gastric cancer patients with regard to histopathological classification and the presence of distant metastases, by using platelet morphological parameters: MPV, L-PLT, MPC, as well as quantitative evaluation of surface receptor expression: CD41a, CD61, CD42b, CD62P, by flow cytometry at the resting state and after TRAP activation. In gastric cancer patients higher values of MPV and LP, as well as decreased MPC values were determined. Quantitative evaluation of surface antigen expression also revealed higher number of CD41a, CD61 and CD62P molecules, as compared with the platelets in the control group. Significant decrease of CD42b molecules' number after TRAP incubation, and the increased CD41a, CD61 and CD62P expression also point to the retained reactivation capacity of platelets. Good correlation between morphological parameters and the number of CD62P molecules indicates the usefulness of routine tests in evaluation of platelet activation.

Does prematurity affect platelet indices?

PURPOSE: The current study objective was to compare blood platelet indices in preterm newborns (PTN) and full term newborns (FTN). MATERIALS AND METHODS: We introduced to our study 51 PTN (25 females, 26 males) and 55 FTN (25 females, 30 males). Platelet indices were estimated in blood samples collected from the umbilical artery. RESULTS: PTN demonstrated a decreased count of blood platelets (197 x 103/microL) as compared to FTN (287 x 103/microL), p=0.0001. Platelet hematocrit (PCT) also showed substantial differences in both groups (PTN=0.16% vs. FTN=0.22%; p=0.001). Mean platelet volume (MPV) was found to be nearly the same (PTN=8.02 fl, FTN=7.79 fl). Platelet distribution width (PDW) was higher in PTN (50.64%) than in FTN (46.54%), p=0.021. Large platelet count (LPLT) was diminished in PTN (5.23%) in comparison with FTN (6.12 %). CONCLUSIONS: A decreased count of blood platelets, platelet hematocrit and increased platelet distribution width may result from a low gestational age or a dysfunction of megakaryocytes and the placenta. Blood platelet indices may be vital in the diagnosis of haemostatic disorders.

Intestinal D-galactose transport in an endotoxemia model in the rabbit.

Lipopolysaccharide (LPS) is an endotoxin causing sepsis. Studies from our laboratory revealed impaired intestinal absorption of L-leucine and D-fructose in LPS-treated rabbits. The aim of this study was to examine intestinal D-galactose transport following intravenous administration of LPS in the rabbit and to identify the cellular mechanisms driving this process. Endotoxin treatment diminished the buildup of D-galactose in intestinal tissue, the mucosal to serosal transepithelial flux of the sugar and its uptake by brush border membrane vesicles (BBMVs). Intracellular signaling pathways associated with protein kinase C (PKC), protein kinase A (PKA), p38 mitogen-activated protein kinase (p38MAPK), Jun N-terminal kinase (JNK), MAPK/extracellular signal-regulated kinases 1 and 2 (MEK1/2) and proteasome were found to be involved in this reduction in sugar uptake. Na(+)/glucose cotransporter 1 (SGLT1) protein levels in BBMVs were lower for LPS-treated animals than control animals. These findings indicate that LPS inhibits the intestinal absorption of D-galactose via a complex cellular mechanism that could involve posttranscriptional regulation of the SGLT1 transporter.

Inhibitory effect of TNF-alpha on the intestinal absorption of galactose.

Sepsis is a systemic response to infection in which toxins, such as bacterial lipopolysaccharide (LPS), stimulate the production of inflammatory mediators like the cytokine tumor necrosis factor alpha (TNF-alpha). Previous studies from our laboratory have revealed that LPS inhibits the intestinal absorption of L-leucine and D-fructose in rabbit when it was intravenously administered, and that TNF-alpha seems to mediate this effect on amino acid absorption. To extend this work, the present study was designed to evaluate the possible effect of TNF-alpha on D-galactose intestinal absorption, identify the intracellular mechanisms involved and establish whether this cytokine mediates possible LPS effects. Our findings indicate that TNF-alpha decreases D-galactose absorption both in rabbit intestinal tissue preparations and brush-border membrane vesicles. Western blot analysis revealed reduced amounts of the Na+/glucose cotransporter (SGLT1) protein in the plasma membrane attributable to the cytokine. On the contrary, TNF-alpha increased SGLT1 mRNA levels. Specific inhibitors of the secondary messengers PKC, PKA, the MAP kinases p38 MAP, JNK, MEK1/2 as well as the proteasome, diminished the TNF-alpha-evoked inhibitory effect. LPS inhibition of the uptake of the sugar was blocked by a TNF-alpha antagonist. In conclusion, TNF-alpha inhibits D-galactose intestinal absorption by decreasing the number of SGLT1 molecules at the enterocyte plasma membrane through a mechanism in which several protein-like kinases are involved.

Changes in platelet CD 62P expression and soluble P-selectin concentration in surgically treated colorectal carcinoma.

PURPOSE: The aim of the present study was to assess the effect of tumor advancement and surgery treatment on P-selectin expression (CD 62P), level of sP-selectin and platelet count. MATERIAL AND METHODS: The study involved 27 colorectal cancer patients (CRC). They were divided into two groups: group B1--18 patients (T2-3N0M0) and group B2--9 patients (T2-4N+M0). In CRC patients the blood was collected three times: 1) before surgery (A0), 2) 3 days after surgery and 3) 12 days after surgery. RESULTS: The results obtained showed that CD 62P expression in CRC patients was twice higher (5.36%) than in control (2.58%) (p < 0.001). The level of sP-selectin concentration in both groups (B1--74.22 ng/mL and B2--70.33 ng/mL) was significantly higher than in control (46.01 ng/mL) (p < 0.001). There was no significant differences in CD 62P expression, plasma sP-selectin concentration and in PLT count between group B1 and B2. Three days after surgery in both groups of patients we observed decreased CD 62P expression and sP-selectin level compared to the results before surgery (p < 0.05). Twelve days after surgery we found an increase in the CD 62P-positive platelets and sP-selectin in group B1 and B2. We found positive correlation between plasma sP-selectin concentration and PLT count in CRC. CONCLUSIONS: In the current study on colorectal cancer we observed platelet hyperactivation, irrespective of tumor clinical advancement. Surgical procedure, in the early period following radical tumor resection, does not totally eliminate platelet activation in vivo.

Divergent mechanisms of cis9, trans11-and trans10, cis12-conjugated linoleic acid affecting insulin resistance and inflammation in apolipoprotein E knockout mice: a proteomics approach.

Conjugated linoleic acids (CLA) affect atherogenesis, but mechanisms are not well understood. We explored how two isomers of CLA, cis9, trans11-CLA and trans10, cis12-CLA, affected lipid and glucose metabolism, as well as hepatic protein expression, in apolipoprotein E knockout mice. After 12 wk of intervention, plasma triglyceride, NEFA, and glucose concentrations were significantly higher in the trans10, cis12-CLA group, whereas plasma triglyceride, NEFA, glucose, and insulin concentrations were significantly lower in the cis9, trans11-CLA group, compared with control mice consuming linoleic acid. Proteomics identified significant up- or down-regulation of 113 liver cytosolic proteins by either CLA isomer. Principal component analysis revealed that the treatment effect of cis9, trans11-CLA was mainly explained by the up-regulation of different posttranslational forms of heat shock protein 70 kD. In contrast, the treatment effect of trans10, cis12-CLA was mainly explained by up-regulation of key enzymes in the gluconeogenic, beta-oxidation, and ketogenesic pathways. Correlation analysis again emphasized the divergent effects of both CLA isomers on different pathways, but also revealed a linkage between insulin resistance and increased levels of hepatic serotransferrin. Thus, our systems biology approach provided novel insights into the mechanisms by which individual CLA isomers differentially affect pathways related to atherogenesis, such as insulin resistance and inflammation.

International conference on the healthy effect of virgin olive oil.

1. Ageing represents a great concern in developed countries because the number of people involved and the pathologies related with it, like atherosclerosis, morbus Parkinson, Alzheimer's disease, vascular dementia, cognitive decline, diabetes and cancer. 2. Epidemiological studies suggest that a Mediterranean diet (which is rich in virgin olive oil) decreases the risk of cardiovascular disease. 3. The Mediterranean diet, rich in virgin olive oil, improves the major risk factors for cardiovascular disease, such as the lipoprotein profile, blood pressure, glucose metabolism and antithrombotic profile. Endothelial function, inflammation and oxidative stress are also positively modulated. Some of these effects are attributed to minor components of virgin olive oil. Therefore, the definition of the Mediterranean diet should include virgin olive oil. 4. Different observational studies conducted in humans have shown that the intake of monounsaturated fat may be protective against age-related cognitive decline and Alzheimer's disease. 5. Microconstituents from virgin olive oil are bioavailable in humans and have shown antioxidant properties and capacity to improve endothelial function. Furthermore they are also able to modify the haemostasis, showing antithrombotic properties. 6. In countries where the populations fulfilled a typical Mediterranean diet, such as Spain, Greece and Italy, where virgin olive oil is the principal source of fat, cancer incidence rates are lower than in northern European countries. 7. The protective effect of virgin olive oil can be most important in the first decades of life, which suggests that the dietetic benefit of virgin olive oil intake should be initiated before puberty, and maintained through life. 8. The more recent studies consistently support that the Mediterranean diet, based in virgin olive oil, is compatible with a healthier ageing and increased longevity. However, despite the significant advances of the recent years, the final proof about the specific mechanisms and contributing role of the different components of virgin olive oil to its beneficial effects requires further investigations.

Animales de experimentación utilizados como modelos en la investigación de la arteriosclerosis / Experimental animals used as models in arteriosclerosis research

La presente revisión aborda el metabolismo lipoproteico comparado y la inducción de la aterosclerosis con sus controversias en varios modelos animales pertenecientes a un amplio espectro evolutivo que abarca desde los roedores (ratón, conejo, rata, hámster, cobaya), las aves (paloma), los cetartiodáctilos (cerdo) y los carnívoros (perro) hasta los primates (macacos, Rhesus, mono verde africano) (AU)

Current review presents an overview of the compared lipoprotein metabolism and atherosclerosis development and their controversies in several animal models covering a wide phylogenetic spectrum. Orders are rodents (mice, rabbits, rats, hamsters, guinea pigs), birds (pigeons), cetartiodactyla (pigs), carnivores (dogs) and primates (macaques, Rhesus, African green monkey) (AU)

The effect of tumor necrosis factor-alpha on D-fructose intestinal transport in rabbits.

Tumor necrosis factor-alpha (TNF-alpha) is an important immunoregulatory cytokine involved in septic responses during bacterial infection. The aim of this study was to examine the effect of TNF-alpha on the transport of D-fructose across rabbit jejunum. A sepsis condition was evoked by intravenous administration of this cytokine and hematological and plasma parameters were analyzed and body temperature was recorded. D-Fructose transport was assayed in rabbit jejunum. Sugar absorption in TNF-alpha treated rabbits was lower than in control animals. TNF-alpha decreased both the mucosal-to-serosal transepithelial flux and the transport across brush border membrane vesicles of D-fructose. The number of D-fructose transporters (GLUT5) was analyzed by Western blot in an attempt to explain this inhibition. TNF-alpha treated animals had lower levels of GLUT5, indicating a reduction in the expression of GLUT5 protein and therefore in transport capacity. The inhibition could also be related with the secretagogue effect of TNF-alpha on the gut since the intracellular tissue water was affected and the absence of chloride ion in the incubation medium partly removed the cytokine inhibition on sugar intestinal transport in treated rabbits. Finally, in terms of possible mediators involved in the TNF-alpha effect, nitric oxide and prostaglandins appeared to play a role in the inhibition of D-fructose intestinal uptake.