El rol femenino en el mercado laboral y el desempleo en Colombia

 En el presente artículo trabajamos respecto al desempleo que presentan las mujeres en Colombia, y en cuáles ciudades es más evidente este fenómeno, gracias a una serie de aspectos que hoy en día se siguen manteniendo. Se realiza una investigación de tipo cualitativo con el fin conocer cuál es la realidad que afrontan las mujeres en el mercado laboral colombiano. Además, se evidencia la falta de oportunidades laborales debido al hecho de ser mujer y la desigualdad que hay por ello, ya que terminan convirtiéndose en un costo a largo plazo para las empresas, en dado caso de quedar en embarazo. Sin olvidar que el estado civil también se convierte en un factor determinante a la hora de la contratación del personal femenino dentro de las organizaciones y la diferencia salarial que se mantiene por solo ser mujer.

Transport of Cytoplasmically Synthesized Proteins into the Mitochondria in a Cell Free System from Neurospora crassa

Synthesis and transport of mitochondrial proteins were followed in a cell-free homogenate of Neurospora crassa in which mitochondrial translation was inhibited. Proteins synthesized on cytoplasmic ribosomes are transferred into the mitochondrial fraction. The relative amounts of proteins which are transferred in vitro are comparable to those transferred in whole cells. Cycloheximide and puromycin inhibit the synthesis of mitochondrial proteins but not their transfer into mitochondria. The transfer of immunoprecipitable mitochondrial proteins was demonstrated for matrix proteins, carboxyatractyloside-binding protein and cytochrome c. Import of proteins into mitochondria exhibits a degree of specificity. The transport mechanism differentiates between newly synthesized proteins and preexistent mitochondrial proteins, at least in the case of matrix proteins. In the cell-free homogenate membrane-bound ribosomes are more active in the synthesis of mitochondrial proteins than are free ribosomes. The finished translation products appear to be released from the membrane-bound ribosomes into the cytosol rather than into the membrane vesicles. The results suggest that the transport of cytoplasmically synthesized mitochondrial proteins is essentially independent of cytoplasmic translation; that cytoplasmically synthesized mitochondrial proteins exist in an extramitochondrial pool prior to import; that the site of this pool is the cytosol for at least some of the mitochondrial proteins; and that the precursors in the extramitochondrial pool differ in structure or conformation from the functional proteins in the mitochondria

Kvaliteta sjemena u ovaca

Reproductive evaluation, the selection of individual breeders, and reproductive biotechnologies are important tools in developing productive and reproductive rates. When choosing a male as a breeding future, determining its general health status and genotypic and phenotypic superiority are necessary. This study evaluated the conventional and functional seminal quality in ovine males. The semen of eleven ovines of different pure races was collected by electroejaculation. The following average values were observed for each conventional parameter: scrotal circumference (CE, 34.3 cm), seminal volume (vol, 1.63 mL), concentration (C, 768.4 x 106/mL), individual motility (MI, 80%), masal motility (MM, 4) and vigor (Vi, 3.7). On the other hand, functional analysis showed plasma membrane integrity (PMI) of 45.7%, mitochondrial membrane potential (MMP) of 38.5%, DNA fragmentation index (DFI) of 17.0%, lipoperoxidation of the membrane (LPO) of 32.7%, and the production of reactive oxygen species (ROS) of 28.56%. Additionally, a high and positive correlation was found for variables concerning seminal quality: Vi and MM, Vi and MI, MMP and MM, MMP and MI, PMI and MMP, as well as ROS and MMP. In contrast, two strongly negative correlations were obtained (C vs. Vol and LPO vs. CE). These are the first estimates of functional seminal quality evaluation of sheep in Colombia. In addition, this study provides a baseline for conventional and functional seminal parameters in the region.Reproduktivna procjena, odabir pojedinačnih rasplodnih mužjaka i reproduktivne biotehnologije važni su alati u unaprjeđenju produktivnih i reproduktivnih stopa. Pri odabiru mužjaka za rasplod, potrebno je određivanje općeg zdravstvenog statusa te genotipske i fenotipske superiornosti. Ovaj rad procjenjuje konvencionalnu i funkcionalnu kvalitetu sjemena u ovnova. Sjeme jedanaest ovnova različitih čistokrvnih pasmina prikupljeno je elektroejakulacijom. Zamijećene su sljedeće prosječne vrijednosti za svaki konvencionalni parametar: opseg skrotuma (CE, 34,3 cm), volumen sjemena (vol, 1,63 mL), koncentracija (C, 768,4 x 106/mL), pojedinačna pokretljivost (MI, 80 %), ukupna pokretljivost (MM, 4) i vitalnost (Vi, 3,7). S druge strane, funkcionalna analiza pokazala je integritet stanične membrane (PMI) od 45,7 %, potencijal mitohondrijske membrane (MMP) od 38,5 %, indeks fragmentacije DNK (DFI) od 17,0%, lipoperoksidaciju membrane (LPO) od 32,7 % i proizvodnju reaktivnih kisikovih spojeva (ROS) od 28,56 %. Uz to je otkrivena i visoka i pozitivna korelacija za varijable o kvaliteti sjemena: Vi i MM, Vi i MI, MMP i MM, MMP i MI, PMI i MMP, kao i ROS i MMP. Suprotno tome, dobivene su dvije vrlo negativne korelacije (C nasuprot Vol i LPO nasuprot CE). To su prve procjene ocjenjivanja funkcionalne kvalitete sjemena ovaca u Kolumbiji. Uz to, ova studija osigurava početnu vrijednost za sve konvencionalne i funkcionalne parametre sjemena u regiji

Serum Concentrations of Myostatin and Myostatin-Interacting Proteins do not differ between young and Scarcopenic elderly men

Peer reviewedPostprin

Activin subfamily peptides predict chronological age in humans

Loss of muscle mass and function are a well‐defined aspect of human aging from the 3rd decade of life, which result in reduced independence and increased mortality. The activin family of peptides contains several endocrine factors (activin A, myostatin, growth and differentiation factor 11 [GDF11]) that may play roles in changes in muscle mass and the aging process, however, it may be simplistic to consider aging as a result of a single peptides changes. Thus, we aimed to examine changes in activin family members across a cohort of healthy individuals of various ages, hypothesizing that these would aid predictive models of age and functional measures of age. Healthy participants (n = 88) were recruited and resting metabolic rate, body composition, grip strength, walking speed, and circulating plasma concentrations of myostatin (total and free), activin A, follistatin‐like binding protein (FLRG), and GDF11 quantified. Simple regressions between circulating factors and chronological age, grip strength, and walking speed were examined. Multiple stepwise regressions for age, grip strength, and walking speed are also reported. Age negatively correlated with total myostatin (P = 0.032, r2 = 0.053), grip strength positively with activin A (P = 0.046, r2 = 0.048), whereas walking speed showed no simple regression relationships. Stepwise regressions suggested a role of total myostatin and activin A in models of age, whereas GDF11 contributed to the model of grip strength. Here we suggest a role for myostatin, activin A, and GDF11 in normal human aging that mirrors animal studies to date. Further interventional studies are required to elicitate the physiological role of these changes in the normal human aging process, and indeed if offsetting these changes can promote successful aging

Ketamine-Induced Apoptosis in Normal Human Urothelial Cells

Recreational abuse of ketamine has been associated with the emergence of a new bladder pain syndrome, ketamine‐induced cystitis, characterised by chronic inflammation and urothelial ulceration. This study investigated the direct effects of ketamine on normal human urothelium maintained in organ culture or as finite cell lines in vitro. Exposure of urothelium to ketamine resulted in apoptosis, with cytochrome c release from mitochondria and significant subsequent caspase 9 and 3/7 activation. The anaesthetic mode‐of‐action for ketamine is mediated primarily through N‐methyl Daspartate receptor (NMDAR) antagonism; however, NHU cells were unresponsive to NMDAR agonists or antagonists and no expression of NMDAR transcript was detected. Exposure to non‐cytotoxic concentrations of ketamine (≤1 mM) induced rapid release of ATP, which activated purinergic P2Y receptors and stimulated the inositol trisphosphate receptor to provoke transient release of calcium from the endoplasmic reticulum into the cytosol. Ketamine concentrations >1 mM were cytotoxic and provoked a largeramplitude increase in cytosolic [Ca2+] that was unresolved. The sustained elevation in cytosolic [Ca2+] was associated with pathological mitochondrial oxygen consumption and ATP deficiency. Damage to the urinary barrier initiates bladder pain and in ketamine‐induced cystitis, loss of urothelium from large areas of the bladder wall is a reported feature. This study offers first evidence for a mechanism of direct toxicity of ketamine to urothelial cells by activating the intrinsic apoptotic pathway

The mechanisms of androgen effects on body composition: mesenchymal pluripotent cell as the target of androgen action

Testosterone supplementation increases muscle mass primarily by inducing muscle fiber hypertrophy; however, the mechanisms by which testosterone exerts its anabolic effects on the muscle are poorly understood. The prevalent view is that testosterone improves net muscle protein balance by stimulating muscle protein synthesis, decreasing muscle protein degradation, and improving the reutilization of amino acids. However, the muscle protein synthesis hypothesis does not adequately explain testosterone-induced changes in fat mass, myonuclear number, and satellite cell number. We postulate that testosterone promotes the commitment of pluripotent stem cells into the myogenic lineage and inhibits their differentiation into the adipogenic lineage. The hypothesis that the primary site of androgen action is the pluripotent stem cell provides a unifying explanation for the observed reciprocal effects of testosterone on muscle and fat mass

Lifelong exercise, but not short-term high-intensity interval training, increases GDF11, a marker of successful aging: a preliminary investigation

Lifelong exercise is associated with regulation of skeletal mass and function, reductions in frailty, and successful aging. Yet, the influence of exercise on myostatin and myostatin-interacting factors is relatively under examined in older males. Therefore, we investigated whether serum total myostatin, free myostatin, follistatin, and growth and differentiation factor 11 (GDF11) were altered following high-intensity interval training (HIIT) in a group of 13 lifelong sedentary (SED; 64 [6] years) and 11 lifelong exercising (LEX; 62 [6] years) older males. SED follistatin was moderately greater than LEX pre-HIIT (Cohen's d = 0.66), and was largely greater post-HIIT (Cohen's d = 1.22). The HIIT-induced increase in follistatin was large in SED (Cohen's d = 0.82) and absent in LEX (Cohen's d = 0.03). GDF11 was higher in LEX pre-HIIT (Cohen's d = 0.49) and post-HIIT (Cohen's d = 0.63) compared to SED. HIIT resulted in no change to GDF11 in LEX or SED (Cohen's d = 0.00–0.03). Peak power output and GDF11 were correlated (r = 0.603), independent of grouping. Differences in GDF11 with lifelong exercise training, paired with the correlation between GDF11 and peak power output, suggested that GDF11 may be a relevant myostatin-interacting peptide to successful aging in humans, and strategies to maintain this need to be further explored

Differing Effects of Younger and Older Human Plasma on C2C12 Myocytes in Vitro

Ageing is associated with a general reduction of physiological function and a reduction of muscle mass and strength. Endocrine factors such as myostatin, activin A, growth and differentiation factor 11 (GDF-11) and their inhibitory peptides influence muscle mass in health and disease. We hypothesised that myocytes cultured in plasma from older and younger individuals would show an ageing effect, with reduced proliferation and differentiation in older environments. C2C12 myoblasts were grown as standard and stimulated with media conditioned with 5% plasma from healthy male participants that were either younger (n = 6, 18–35 years of age) or older (n = 6, >57 years of age). Concentration of plasma myostatin (total and free), follistatin-like binding protein (FLRG), GDF-11 and activin A were quantified by ELISA. Both FLRG and activin A were elevated in older individuals (109.6 and 35.1% increase, respectively), whilst myostatin (free and total) and GDF-11 were not. Results indicated that plasma activin A and FLRG were increased in older vs. younger participants, GDF11 and myostatin did not differ. Myoblasts in vitro showed no difference in proliferation rate between ages, however scratch closure was greater in younger vs. older plasma stimulated myoblasts (78.2 vs. 87.2% of baseline scratch diameter, respectively). Myotube diameters were larger in cells stimulated with younger plasma than with older at 24 and 48 h, but not at 2 h. A significant negative correlation was noted between in vivo plasma FLRG concentration and in vitro myotube diameter 48 h following plasma stimulation (r2 = 0.392, p = 0.030). Here we show that myoblasts and myotubes cultured in media conditioned with plasma from younger or older individuals show an ageing effect, and further this effect moderately correlates with circulating FLRG concentration in vivo. The effect of ageing on muscle function may not be innate to the tissue, but involve a general cellular environment change. Further work is needed to examine the effect of increased FLRG concentration on muscle function in ageing populations

Increased Secretion and Expression of Myostatin in Skeletal Muscle From Extremely Obese Women

OBJECTIVE—Obesity is associated with endocrine abnormalities that predict the progression of insulin resistance to type 2 diabetes. Because skeletal muscle has been shown to secrete proteins that could be used as biomarkers, we characterized the secreted protein profile of muscle cells derived from extremely obese (BMI 48.8 ± 14.8 kg/m2; homeostasis model assessment [HOMA] 3.6 ± 1.0) relative to lean healthy subjects (BMI 25.7 ± 3.2 kg/m2; HOMA 0.8 ± 0.2)