The polymorphism T1470A of the SLC16A1 gene is associated with the lactate and ventilatory thresholds but not with fat oxidation capacity in young men

PURPOSE

To examine the association of the single nucleotide polymorphism A1470T in the SLC16A1 gene with blood lactate accumulation during a graded exercise test and its associated metaboreflex.

METHODS

Forty-six Latin-American men (Age: 27 ± 6 years; Body fat: 17.5 ± 4.7%) performed a graded exercise test on a treadmill for the assessment of maximal oxygen uptake (VO2max), lactate threshold (LT), ventilatory threshold (VT) and the exercise intensity corresponding to maximal fat oxidation rate (FATmax), via capillary blood samples and indirect calorimetry. Genomic DNA was extracted from a peripheral blood sample. Genotyping assay was carried out by real-time polymerase chain reaction to identify the A1470T polymorphism (rs1049434).

RESULTS

Genotypes distribution were in Hardy-Weinberg equilibrium (X2 = 5.6, p > 0.05), observing allele frequencies of 0.47 and 0.53 for the A and T alleles, respectively. No difference in VO2max, body composition nor FATmax were observed across genotypes, whereas carriers of the TT genotype showed a higher LT (24.5 ± 2.2 vs. 15.6 ± 1.7 mL kg-1 min-1, p < 0.01) and VT in comparison to carriers of the AA + AT genotypes (32.5 ± 3.3 vs. 21.7 ± 1.5 mL kg-1 min-1, p < 0.01). Both, VO2max and the A1470T polymorphism were positively associated to the LT (R2 = 0.50, p < 0.01) and VT (R2 = 0.55, p < 0.01). Only VO2max was associated to FATmax (R2 = 0.39, p < 0.01).

CONCLUSION

Independently of cardiorespiratory fitness, the A1470T polymorphism is associated to blood lactate accumulation and its associated ventilatory response during submaximal intensity exercise. However, the A1470 polymorphism does not influence fat oxidation capacity during exercise in young men.

Metabolic Biomarkers in Adults with Type 2 Diabetes: The Role of PPAR-γ2 and PPAR-β/δ Polymorphisms

Glucose and lipid metabolism regulation by the peroxisome proliferator-activated receptors (PPARs) has been extensively reported. However, the role of their polymorphisms remains unclear.

OBJECTIVE

To determine the relation between PPAR-γ2 rs1801282 (Pro12Ala) and PPAR-β/δ rs2016520 (+294T/C) polymorphisms and metabolic biomarkers in adults with type 2 diabetes (T2D).

MATERIALS AND METHODS

We included 314 patients with T2D. Information on anthropometric, fasting plasma glucose (FPG), HbA1c and lipid profile measurements was taken from clinical records. Genomic DNA was obtained from peripheral blood. End-point PCR was used for PPAR-γ2 rs1801282, while for PPAR-β/δ rs2016520 the PCR product was digested with Bsl-I enzyme. Data were compared with parametric or non-parametric tests. Multivariate models were used to adjust for covariates and interaction effects.

RESULTS

minor allele frequency was 12.42% for PPAR-γ2 rs1801282-G and 13.85% for PPAR-β/δ rs2016520-C. Both polymorphisms were related to waist circumference; they showed independent effects on HbA1c, while they interacted for FPG; carriers of both PPAR minor alleles had the highest values. Interactions between FPG and polymorphisms were identified in their relation to triglyceride level.

CONCLUSIONS

PPAR-γ2 rs1801282 and PPAR-β/δ rs2016520 polymorphisms are associated with anthropometric, glucose, and lipid metabolism biomarkers in T2D patients. Further research is required on the molecular mechanisms involved.

Association Among Different Aerobic Threshold Markers and FATmax in Men With Obesity

Purpose: This work studies the interrelation of the first ventilatory threshold (VT1), the heart rate inflection point (HRIP), and the exercise intensity at which blood lactate started to accumulate (LIAB) or increased 1 mmol∙L-1 above baseline (LT+1.0); and examinee their association with the exercise intensity eliciting maximal fat oxidation (FATmax). Methods: Eighteen young men with obesity performed an incremental-load exercise test on a treadmill after overnight fasting. Gas exchange, heart rate, and blood lactate concentration were recorded. Linear regression analysis was used to determine the association among FATmax and AeT markers. A standard error of estimate (SEE) ≤9 beats∙min-1 and the concordance correlation coefficient (CCC) were used to examine the accuracy of different AeT for predicting FATmax heart rate. Results: The FATmax occurred at 36±7%VO2peak before the HRIP (41±6%VO2peak), LIAB (42±10%VO2peak), LT+1.0 (61±9%VO2peak) and VT1 (40±7%VO2peak). Furthermore, the HRIP (R2= 0.71; SEE= 6 beats∙min-1; CCC=0.77), VT1 (R2= 0.76; SEE= 5 beats∙min-1; CCC=0.84) and LIAB (R2= 0.77; SEE= 5 beats∙min-1; CCC=0.85) were strongly associated to FATmax and showed an acceptable estimation error for predicting FATmax heart rate. Otherwise, LT+1.0 showed a moderate correlation with FATmax, a low accuracy for predicting FATmax HR (R2= 0.57; SEE= 7 beats∙min-1; CCC=0.66) and a poor agreement with the rest of AeT markers (Bias: +20%VO2peak). Conclusion: The HRIP, LIAB and VT1 did not perfectly captured the FATmax, however, these could be exchanged for predicting the FATmax heart rate in men with obesity. Moreover, the LT+1.0 should not be used for AeT or FATmax assessment in men with obesity.

Early-Life Metabolic Traits and Physical Fitness in Tarahumara, Mennonite, and Mestizo Adolescents from Northern Mexico

The WHO identifies high BMI, high blood pressure, and high fasting plasma glucose as chronic disease risk factors, whereas physical fitness is identified as a protective behavioral factor. This study responds to the rising interest in assessing metabolic factors and physical activity within young populations of Mestizo, Tarahumara, and Mennonite from Chihuahua Mexico, due to its strong relationship with disease development and low well-being. A cross-sectional study was conducted with 201 teenagers from rural towns in Northern Mexico, and relationships between physical fitness and cardio-metabolic risk related to anthropometric, glycolipid, and vascular function factors were assessed. ANOVA-tested differences among ethnic groups using physical fitness as a grouping variable and measures of cardio-metabolic risks were used as dependent variables. A stepwise regression analysis allowed us to identify the best predictors for physical fitness. Clinical risk factors were analyzed by ethnic group and sex. No differences were found among ethnic groups in physical fitness and cardio-metabolic health risks; sex differentiated higher health risks related to behavioral factors, since young women showed lower physical fitness across ethnicities. Clinically, the Mestizo sample showed higher numbers of individuals with one risk factor. Mennonites showed a high frequency of anthropometric and fitness health risks with low glycolipid and vascular risks. Tarahumara had fewer risk factors as compared with both Mestizo and Mennonite. Rural populations are harder to reach, both for health assessment and intervention; health professionals must work close to local community organizations to gain access.

FAT/CD36 Participation in Human Skeletal Muscle Lipid Metabolism: A Systematic Review

Fatty acid translocase/cluster of differentiation 36 (FAT/CD36) is a multifunctional membrane protein activated by a high-fat diet, physical exercise, fatty acids (FAs), leptin, and insulin. The principal function of FAT/CD36 is to facilitate the transport of long-chain fatty acids through cell membranes such as myocytes, adipocytes, heart, and liver. Under high-energy expenditure, the different isoforms of FAT/CD36 in the plasma membrane and mitochondria bind to the mobilization and oxidation of FAs. Furthermore, FAT/CD36 is released in its soluble form and becomes a marker of metabolic dysfunction. Studies with healthy animals and humans show that physical exercise and a high-lipid diet increase FAT/CD36 expression and caloric expenditure. However, several aspects such as obesity, diabetes, Single Nucleotide polymorphisms (SNPs), and oxidative stress affect the normal FAs metabolism and function of FAT/CD36, inducing metabolic disease. Through a comprehensive systematic review of primary studies, this work aimed to document molecular mechanisms related to FAT/CD36 in FAs oxidation and trafficking in skeletal muscle under basal conditions, physical exercise, and diet in healthy individuals.

Exercise Fat Oxidation Is Positively Associated with Body Fatness in Men with Obesity: Defying the Metabolic Flexibility Paradigm

Obesity is thought to be associated with a reduced capacity to increase fat oxidation in response to physical exercise; however, scientific evidence supporting this paradigm remains scarce. This study aimed to determine the interrelationship of different submaximal exercise metabolic flexibility (Metflex) markers and define its association with body fatness on subjects with obesity. Twenty-one male subjects with obesity performed a graded-intensity exercise protocol (Test 1) during which cardiorespiratory fitness (CRF), maximal fat oxidation (MFO) and its corresponding exercise intensity (FATmax) were recorded. A week afterward, each subject performed a 60-min walk (treadmill) at FATmax (Test 2), and the resulting fat oxidation area under the curve (TFO) and maximum respiratory exchange ratio (RER_peak) were recorded. Blood lactate (LA_b) levels was measured during both exercise protocols. Linear regression analysis was used to study the interrelationship of exercise Metflex markers. Pearson’s correlation was used to evaluate all possible linear relationships between Metflex and anthropometric measurement, controlling for CRF). The MFO explained 38% and 46% of RER_peak and TFO’s associated variance (p < 0.01) while TFO and RER_peak were inversely related (R² = 0.54, p < 0.01). Body fatness positively correlated with MFO (r = 0.64, p < 0.01) and TFO (r = 0.63, p < 0.01) but inversely related with RER_peak (r = −0.67, p < 0.01). This study shows that MFO and RER_peak are valid indicators of TFO during steady-state exercise at FATmax. The fat oxidation capacity is directly associated with body fatness in males with obesity.

COVID-19, diabetes y el sistema inmunológico

En el año de 2019 en la provincia de Wuhan, China, se reportó un brote de neumonías atípicas, con síntomas similares a los del Síndrome Respiratorio Agudo Severo (SARS), brote reportado en el 2003, y al Síndrome Respiratorio del Oriente Medio (MERS), brote reportado en 2012 en Arabia Saudita.  Esta enfermedad emergente fue causada por el nuevo coronavirus “Síndrome Respiratorio Agudo Severo Coronavirus 2” (SARS-CoV-2) o también denominada COVID-19 del inglés Coronavirus desease 2019, caracterizado por presentar severos problemas respiratorios y diversas manifestaciones extrapulmonares. Al momento se ha reportado una elevada tasa de mortalidad en individuos del sexo masculino, en adultos mayores de 60 años, y en personas con comorbilidades como diabetes obesidad, hipertensión y problemas cardiacos. La diabetes es una enfermedad caracterizada por resistencia a insulina, pérdida de función de células β en el páncreas, y desbalance del sistema inmune por el estado de inflamación crónica. En pacientes graves con COVID-19, se ha observado una secreción alterada de citocinas pro inflamatorias, si esto ocurre en un paciente diabético, que ya tiene un estado inflamatorio per se, se induce inflamación exacerbada y una falla multiorgánica que puede desencadenar en la muerte de los pacientes. Diversos autores señalan como hipótesis que la hiperglicemia favorece la replicación viral, por lo que en un paciente “diabético con infección COVID-19”, es primordial mantener un control glicémico adecuado. Los tratamientos para COVID-19 se han enfocado en disminuir los síntomas, el uso de antivirales, antiinflamatorios, anticuerpos monoclonales y plasma convaleciente COVID-19 ha mostrado resultados variables. Para el control de esta infección viral es necesaria una vacuna, al momento existen más de 150 candidatos, con una eficiencia que va del rango de 70 al 95%, pero aún falta determinar la inmunidad a largo plazo en las personas vacunadas. Esta revisión aborda las características de la infección por SARS-CoV2 y la respuesta inmunitaria en pacientes diabéticos frente a COVID-19.

[Quantitative classification of pivot-shift maneuver]

INTRODUCTION

The diagnosis of ACL injury is established with the physical examination that includes the Lachman maneuver and the pivot-shift test since it has the highest positive predictive value. Imaging tests such as MRI are still used for confirmation of the same; so the quantification of clinical maneuvers is sought.

MATERIAL AND METHODS

Prospective clinical study in which the maneuvers of pivot-shift and Lachman are quantified for later classification.

RESULTS

Of 36 patients, 64% found a range between 0 and 3 mm when subtracting the value of the affected knee from the value of the healthy knee. It was found that 28% of the patients recorded values of KT-1000 ranging between 4 and 6 mm of displacement. In 8% of the total patients, values of KT-1000 were found that exceeded 7 mm of displacement. The data obtained are normalized and classified into 3 degrees of injury: grade 1 with partial injury; grade 2 with complete anteromedial and partial injury in posterolateral bundle; grade 3 with complete injury of both bundles.

CONCLUSION

A classification is proposed for the degrees of ACL injury with future application to a more personalized reconstruction.

Chronic Effect of Fatmax Training on Body Weight, Fat Mass, and Cardiorespiratory Fitness in Obese Subjects: A Meta-Analysis of Randomized Clinical Trials

Exercise training performed at the maximal fat oxidation intensity (FMT) stands out as a potential treatment of overweight and obesity. This work is a meta-analysis of randomized clinical trials of studies about the effect of FMT on fat mass and maximal oxygen consumption using PubMed, SCOPUS, EBSCOhost, and ScienceDirect as databases. Two independent reviewers selected 11 trials from 356 publications identified by the following keywords: fatmax, lipoxmax, maximal fat oxidation, peak of fat oxidation, physical training, physical exercise, body fat (BF), fat mass, overweight, and obesity. The risk of bias was assessed following the Cochrane Guidelines. The pooled mean difference was computed for each outcome with the random-effects model and the inverse-variance method. The meta-analysis was performed with the RevMan software v 5.3, and the heterogeneity across studies by the I². The statistical significance was accepted at p < 0.05. Results showed that the FMT reduced body weight (MD = -4.30 kg, p < 0.01, I² = 0%), fat mass (MD = -4.03 kg, p < 0.01, I² = 0%), and waist circumference (MD = -3.34 cm, p < 0.01). Fat-free mass remains unchanged (MD = 0.08 kg, p = 0.85), but maximal oxygen consumption increased (MD = 2.96 mL∙kg^-1∙min^-1, p < 0.01, I² = 0%). We conclude that FMT at short and medium-term (eight to twenty weeks) reduces body weight and BF, increasing cardiovascular fitness in low physical fitness people with obesity.

Pro12Ala PPAR-γ2 and +294T/C PPAR-δ Polymorphisms and Association with Metabolic Traits in Teenagers from Northern Mexico

Peroxisome proliferator-activated receptors (PPARs) play roles in glucose and lipid metabolism regulation. Pro12Ala PPAR-γ2 and +294T/C PPAR-δ have been associated with dyslipidemia, hyperglycemia and high body mass index (BMI). We compared metabolic traits and determined associations with Pro12Ala PPAR-γ2 or +294T/C PPAR-δ polymorphism among teenagers from different ethnicity. Four hundred and twelve samples with previous biochemical and biometric measurements were used. Genomic DNA from peripheral blood was extracted and analyzed by end-point PCR for Pro12Ala PPAR-γ2. The +294T/C PPAR-δ PCR product was also digested with Bsl I. Two genotype groups were formed: major allele homozygous and minor allele carriers. Pro12Ala PPAR-γ2 G minor allele frequencies were: 10% in Mestizo-1, 19% in Mestizo-2, 23% in Tarahumara, 12% in Mennonite, and 17% in the total studied population. The +294T/C PPAR-δ C minor allele frequencies were: 18% in Mestizo-1, 20% in Mestizo-2, 6% in Tarahumara, 13% in Mennonite, and 12% in the total studied population. Teenagers with PPAR-γ2 G allele showed a greater risk for either high waist/height ratio or low high-density lipoprotein; and, also had lower total cholesterol. Whereas, PPAR-γ2 G allele showed lower overweight/obesity phenotype (BMI Z-score) frequency, PPAR-δ C allele was a risk factor for it. Metabolic traits were associated with both PPAR polymorphisms.

Ashwin Gene Expression Profiles in Oocytes, Preimplantation Embryos, and Fetal and Adult Bovine Tissues

Simple Summary

Ashwin is a gene involved in the morphogenesis of the central nervous system and the early embryonic development of Xenopus laevis. The analysis of its phylogeny in silico has shown that its functions are restricted to vertebrates, but we lack additional information regarding its biological importance in higher vertebrates, such as mammals. The present study reveals the wide and variable expression of this gene in different bovine organs and confirms its significant expression during early embryonic development, with a pattern similar to that reported for maternal genes. In addition, specific expression of this gene throughout follicular development and during bovine spermatogenesis is revealed, leading to the proposal of ashwin as a new gene with important biological implications in bovine development and reproduction.

Abstract

The ashwin gene, originally identified in Xenopus laevis, was found to be expressed first in the neural plate and later in the embryonic brain, eyes, and spinal cord. Functional studies of ashwin suggest that it participates in cell survival and anteroposterior patterning. Furthermore, ashwin is expressed zygotically in this species, which suggests that it participates in embryonic development. Nevertheless, the expression of this gene has not been studied in mammals. Thus, the aim of this study was to analyze the ashwin expression pattern in bovine fetal and adult tissues, as well as in three independent samples of immature and mature oocytes, and in two- to four-, and eight-cell embryos, morula, and blastocysts. Spatiotemporal expression was analyzed using real-time polymerase chain reaction (PCR); ashwin mRNA was detected in all tissues analyzed, immature and mature oocytes, and two- to eight-cell embryos. It was down-regulated in morula and blastocysts, suggesting that this expression profile is similar to that of maternal genes. Immunohistochemical localization of the ashwin protein in fetal and adult ovaries and testes reveals that this protein is consistently present during all stages of follicular development and during bovine spermatogenesis. These observations lead us to propose ashwin as an important gene involved in mammalian reproduction.

[Comparative study of anterior cruciate ligament reconstruction between the One Band and U-Two techniques]

INTRODUCTION

ACL injuries are found within the most common ligament injuries. This has led to the development of different surgical techniques to restore knee stability.

MATERIAL Y METHODS

Clinical study, randomized, blind comparing ACL reconstruction techniques with One Band and «U-Two» using clinical scales and arthrometria with KT-1000 and Pivot Shift Meter.

RESULTS

Of 36 patients, 52.94% was drawn for the One Band technique and 47.06% for «U-Two». 11.76% of patients had a displacement greater than 11mm in the affected knee with KT-1000. 8.82% showed an equal anterior displacement on both knees. One patient had a major previous displacement after reconstruction surgery with the one band technique, but with improvement on clinical scales. Pivot Shift measurements found a difference in displacement greater than 4,000 m/s on the X axis following the One Band technique compared to the healthy knee calculating integrals, while with U-Two the difference was less than 600 m/s. On the Y axis a difference of 3,500 m/s was found between the healthy and the injured leg, which decreases to less than 2,000 m/s after reconstruction using U-Two technique.

CONCLUSIONS

Differences have been found throughout the study in patient evolution, indicating that repair using the U-Dos technique has better results in recovering the anteroposterior and rotational stability of the affected limb.

Sistema antioxidante, actividad física y consumo máximo de oxígeno en adultos jóvenes

La actividad física (AF) moderada y parámetros adecuados de composición corporal se sugiere que tienen efectos benéficos sobre el sistema antioxidante total (SAT). El consumo de oxígeno por ejercicio vigoroso genera producción de radicales libres. El objetivo de este trabajo fue analizar la relación del SAT, AF, consumo máximo de oxígeno (VO2máx) y composición corporal en adultos jóvenes. Se estudió una muestra no probabilística de 56 participantes con un promedio de edad de 20.7±2.1 años. El nivel de AF se evaluó mediante bcuestionario y el VO2máx por la prueba Course-Navette; la composición corporal por impedancia bioeléctrica y el SAT por técnica colorimétrica en plasma. Los datos se analizaron mediante pruebas t-student o suma de rangos de Wilcoxon para determinar diferencias de acuerdo al género. Se analizó la relación entre las variables de interés mediante correlación de Pearson o Spearman. Los varones obtuvieron mayor VO2máx que las mujeres (p=0.01). No se encontraron diferencias en SAT por género. Se encontró una correlación inversa entre SAT y METs reportados en varones (r=-0.5 p=0.01). Se concluye que hay una modulación de SAT por el nivel de AF dependiente del género. No se encontró relación con el VO2máx y variables de composición corporal.

GSTT1 and GSTM1 null variants in Mestizo and Amerindian populations from northwestern Mexico and a literature review

The GSTT1 and GSTM1 genes are key molecules in cellular detoxification. Null variants in these genes are associated with increase susceptibility to developing different types of cancers. The aim of this study was to determine the prevalence of GSTT1 and GSTM1 null genotypes in Mestizo and Amerindian individuals from the Northwestern region of Mexico, and to compare them with those reported worldwide. GSTT1 and GSTM1 null variants were genotyped by multiplex PCR in 211 Mestizos and 211 Amerindian individuals. Studies reporting on frequency of GSTT1 and GSTM1 null variants worldwide were identified by a PubMed search and their geographic distribution were analyzed. We found no significant differences in the frequency of the null genotype for GSTT1 and GSM1 genes between Mestizo and Amerindian individuals. Worldwide frequencies of the GSTT1 and GSTM1 null genotypes ranges from 0.10 to 0.51, and from 0.11 to 0.67, respectively. Interestingly, in most countries the frequency of the GSTT1 null genotype is common or frequent (76%), whereas the frequency of the GSMT1 null genotype is very frequent or extremely frequent (86%). Thus, ethnic-dependent differences in the prevalence of GSTT1 and GSTM1 null variants may influence the effect of environmental carcinogens in cancer risk.

A Trichomonas vaginalis 120 kDa protein with identity to hydrogenosome pyruvate:ferredoxin oxidoreductase is a surface adhesin induced by iron

Trichomonas vaginalis, a human sexually transmitted protozoan, relies on adherence to the vaginal epithelium for colonization and maintenance of infection in the host. Thus, adherence molecules play a fundamental role in the trichomonal infection. Here, we show the identification and characterization of a 120 kDa surface glycoprotein (AP120) induced by iron, which participates in cytoadherence. AP120 is synthesized by the parasite when grown in 250 microM iron medium. Antibodies to AP120 and the electro-eluted AP120 inhibited parasite adherence in a concentration-dependent manner, demonstrating its participation in cytoadherence. In addition, a protein of 130 kDa was detected on the surface of HeLa cells as the putative receptor for AP120. By peptide matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF-MS), the AP120 adhesin showed homology with a hydrogenosomal enzyme, the pyruvate:ferredoxin oxidoreductase (PFO) encoded by the pfoa gene. This homology was confirmed by immunoblot and indirect immunofluorescence assays with an antibody to the carboxy-terminus region of the Entamoeba histolytica PFO. Reverse transcription polymerase chain reaction (RT-PCR) assays showed that a pfoa-like gene was better transcribed in trichomonads grown in iron-rich medium. In conclusion, the homology of AP120 to PFO suggests that this novel adhesin induced by iron could be an example of moonlighting protein in T. vaginalis.