Variations in exercise ventilation in hypoxia will affect oxygen uptake.

Reports of VO2 response differences between normoxia and hypoxia during incremental exercise do not agree. In this study VO2 and VE were obtained from 15-s averages at identical work rates during continuous incremental cycle exercise in 8 subjects under ambient pressure (633 mmHg ≈1,600 m) and during duplicate tests in acute hypobaric hypoxia (455 mmHg ≈4,350 m), ranging from 49 to 100% of VO2 peak in hypoxia and 42-87% of VO2 peak in normoxia. The average VO2 was 96 mL/min (619 mL) lower at 455 mmHg (n.s. P = 0.15) during ramp exercises. Individual response points were better described by polynomial than linear equations (mL/min/W). The VE was greater in hypoxia, with marked individual variation in the differences which correlated significantly and directly with the VO2 difference between 455 mmHg and 633 mmHg (P = 0.002), likely related to work of breathing (Wb). The greater VE at 455 mmHg resulted from a greater breathing frequency. When a subject's hypoxic ventilatory response is high, the extra work of breathing reduces mechanical efficiency (E). Mean ∆E calculated from individual linear slopes was 27.7 and 30.3% at 633 and 455 mmHg, respectively (n.s.). Gross efficiency (GE) calculated from mean VO2 and work rate and correcting for Wb from a VE-VO2 relationship reported previously, gave corresponding values of 20.6 and 21.8 (P = 0.05). Individual variation in VE among individuals overshadows average trends, as also apparent from other reports comparing hypoxia and normoxia during progressive exercise and must be considered in such studies.

Equine blastocyst production under different incubation temperatures and different CO2 concentrations during early cleavage.

Some basic parameters for equine invitro embryo production have not yet been established, including the optimum temperature for maturation and embryo culture, and the optimum CO2 concentration and pH during early embryo development. To explore this, we first performed cultures in incubators set at 37.2°C, 37.7°C or 38.2°C. At these temperatures, the corresponding maturation rates were 33%, 38% and 42%; cleavage rates were 84%, 86% and 88%; and blastocyst rates were 35%, 44% and 44% per injected oocyte. These rates did not differ significantly (P>0.2). We then evaluated three different CO2 concentrations (6%, 6.5% or 7% CO2) in 5% O2 for culture over Days 0-5 after intracytoplasmic sperm injection, using a commercial human embryo medium with added serum, at 38.2°C. The pH values of these media were 7.36, 7.33 and 7.29 respectively. In the presence of 6%, 6.5% or 7% CO2, cleavage rates were 68%, 80% and 70% respectively, and blastocyst rates per injected oocyte were 42%, 54% and 27% respectively. The blastocyst rate for the 7% CO2 treatment was significantly lower than that for the 6.5% CO2 treatment (P<0.05). We conclude that equine invitro embryo production is equally effective within the range of 37.2-38.2°C, but that equine early cleavage stage development is sensitive to small changes in CO2 atmosphere and/or medium pH.

Lower blastocyst quality after conventional vs. Piezo ICSI in the horse reflects delayed sperm component remodeling and oocyte activation.

PURPOSE: The aim of this study was to evaluate the differential effects of conventional and Piezo-driven ICSI on blastocyst development, and on sperm component remodeling and oocyte activation, in an equine model. METHODS: In vitro-matured equine oocytes underwent conventional (Conv) or Piezo ICSI, the latter utilizing fluorocarbon ballast. Blastocyst development was compared between treatments to validate the model. Then, oocytes were fixed at 0, 6, or 18 h after injection, and stained for the sperm tail, acrosome, oocyte cortical granules, and chromatin. These parameters were compared between injection techniques and between sham-injected and sperm-injected oocytes among time periods. RESULTS: Blastocyst rates were 39 and 40%. The nucleus number was lower, and the nuclear fragmentation rate was higher, in blastocysts produced by Conv. Cortical granule loss started at 0H after both sperm and sham injection. The acrosome was present at 0H in both ICSI treatments, and persisted to 18H in significantly more Conv than Piezo oocytes (72 vs. 21%). Sperm head area was unchanged at 6H in Conv but significantly increased at this time in Piezo; correspondingly, at 6H significantly more Conv than Piezo oocytes remained at MII (80 vs. 9.5%). Sham injection did not induce significant meiotic resumption. CONCLUSIONS: These data show that Piezo ICSI is associated with more rapid sperm component remodeling and oocyte meiotic resumption after sperm injection than is conventional ICSI, and with higher embryo quality at the blastocyst stage. This suggests that there is value in exploring the Piezo technique, utilized with a non-toxic fluorocarbon ballast, for use in clinical human ICSI.

Effect of oral administration of Tribulus terrestris extract on semen quality and body fat index of infertile men.

Male fertility can be evaluated through complete semen analysis. Plants belonging to the Tribulus genus are known for their role in enhancing sex hormone levels and semen quality. The aim of this study was to evaluate the effects of T. terrestris on semen quality and physiological parameters. Sixty-five men with abnormal semen evaluation were included in this study, in which they were prescribed with oral administration of Androsten® (250 mg of Tribulus terrestris dried extract per capsule). Body fat percentage, lean muscle mass gain, fluctuation in steroid hormone levels and all semen parameters were analysed during the period of treatment. The results demonstrated that decrease in the percentage of body fat and increase in lean mass were significant, as well as increase in dihydrotestosterone levels. Complete semen analysis evaluated at the end of treatment showed significant enhancement in sperm concentration, motility and liquefaction time. Protodioscin, the main phytochemical agent of the Tribulus genus, acts on sertoli cells, germ cell proliferation and growth of seminiferous tubules. This component is known to convert testosterone into dihydrotestosterone, which plays important roles in male attributes. Our results indicate the therapeutic use of Tribulus terrestris by men presenting altered semen parameters, and/or undergoing infertility treatment.

VESTPD as a measure of ventilatory acclimatization to hypobaric hypoxia.

This study compared the ventilation response to an incremental ergometer exercise at two altitudes: 633 mmHg (resident altitude = 1,600 m) and following acute decompression to 455 mmHg (≈4,350 m altitude) in eight male cyclists and runners. At 455 mmHg, the VESTPD at RER <1.0 was significantly lower and the VEBTPS was higher because of higher breathing frequency; at VO2max, both VESTPD and VEBTPS were not significantly different. As percent of VO2max, the VEBTPS was nearly identical and VESTPD was 30% lower throughout the exercise at 455 mmHg. The lower VESTPD at lower pressure differs from two classical studies of acclimatized subjects (Silver Hut and OEII), where VESTPD at submaximal workloads was maintained or increased above that at sea level. The lower VESTPD at 455 mmHg in unacclimatized subjects at submaximal workloads results from acute respiratory alkalosis due to the initial fall in HbO2 (≈0.17 pHa units), reduction in PACO2 (≈5 mmHg) and higher PAO2 throughout the exercise, which are partially pre-established during acclimatization. Regression equations from these studies predict VESTPD from VO2 and PB in unacclimatized and acclimatized subjects. The attainment of ventilatory acclimatization to altitude can be estimated from the measured vs. predicted difference in VESTPD at low workloads after arrival at altitude.

Does heat acclimation improve exercise capacity at altitude? A cross-tolerance model.

New approaches to inducing altitude acclimation in a relatively short timeframe are needed, as it is not practical for many soldiers and athletes to gain access to specialized training facilities. Acclimation to one environmental stressor could enhance adaptation to various other stressors in animals and humans. This phenomenon has been described as cross-tolerance and involves the activation of common protective pathways. The purpose of this review is to discuss possible mechanisms involved in the cross-tolerance between heat and hypoxia. Future data could potentially support the use of a cross-tolerance model as a means for military personnel to prepare for deployment to high-altitude environments, as well as for athletes competing at high altitude.

Long-term type 1 diabetes impairs decidualization and extracellular matrix remodeling during early embryonic development in mice.

INTRODUCTION: Endometrial decidualization and associated extracellular matrix (ECM) remodeling are critical events to the establishment of the maternal-fetal interface and successful pregnancy. Here, we investigated the impact of type 1 diabetes on these processes during early embryonic development, in order to contribute to the understanding of the maternal factors associated to diabetic embryopathies. METHODS: Alloxan-induced diabetic Swiss female mice were bred after different periods of time to determine the effects of diabetes progression on the development of gestational complications. Furthermore, the analyses focused on decidual development as well as mRNA expression, protein deposition and ultrastructural organization of decidual ECM. RESULTS: Decreased number of implantation sites and decidual dimensions were observed in the group mated 90-110 days after diabetes induction (D), but not in the 50-70D group. Picrosirius staining showed augmentation in the fibrillar collagen network in the 90-110D group and, following immunohistochemical examination, that this was associated with increase in types I and V collagens and decrease in type III collagen and collagen-associated proteoglycans biglycan and lumican. qPCR, however, demonstrated that only type I collagen mRNA levels were increased in the diabetic group. Alterations in the molecular ratio among distinct collagen types and proteoglycans were associated with abnormal collagen fibrillogenesis, analyzed by transmission electron microscopy. CONCLUSIONS: Our results support the concept that the development of pregnancy complications is directly related with duration of diabetes (progression of the disease), and that this is a consequence of both systemic factors (i.e. disturbed maternal endocrine-metabolic profile) and uterine factors, including impaired decidualization and ECM remodeling.

Agreement in the interpretation of magnetic resonance images of the lumbar spine.

BACKGROUND: Correlation between clinical features and magnetic resonance imaging (MRI) findings is essential in low-back-pain patients. Most previous studies have analyzed concordance in the interpretation of lumbar MRI among a few radiologists who worked together. This may have overestimated concordance. PURPOSE: To evaluate intra- and interobserver agreement in the interpretation of lumbar MRI performed in an open 0.2 T system. MATERIAL AND METHODS: Seven radiologists from two different geographic settings in Spain interpreted the lumbar MRIs of 50 subjects representative of the general Danish population aged 40 years. The radiologists interpreted the images in routine clinical practice, having no knowledge of the clinical and demographic characteristics of the subjects and blinded to their colleagues' assessments. Six of the radiologists evaluated the same MRIs 14 days later, having no knowledge of the previous results. Data on the existence of disc degeneration, high-intensity zones, disc contour, Schmorl nodes, Modic changes, osteophytes, spondylolisthesis, and spinal stenosis were collected in the Nordic Modic Consensus Group Classification form. Intra- and interobserver agreement was analyzed for variables with a prevalence >or=10% and

Fiebre e hiperprolactinemia como primera manifestación de histiocitosis de células de Langerhans / Fever and hyperprolactinaemia as the onset of Langerhans´ cell histiocytosis

La histiocitosis de células de Langerhans es una entidad infrecuente, que consiste en la proliferación e infiltración de histiocitos en diferentes tejidos y órganos. Su etiología es desconocida y es más frecuente en niños. Las formas de presentación son variadas y el síntoma inicial suele ser la poliuria-polidipsia, secundaria a diabetes insípida, aunque también se han descrito otras manifestaciones como rash cutáneo, disnea y taquipnea, entre otros. El diagnóstico se realiza por la observación de las células de Langerhans en la biopsia de las lesiones. El pronóstico es variable, dependiendo de los órganos afectos y el tratamiento, por tanto, deberá individualizarse en cada caso. La hiperprolactinemia en la HCL es muy infrecuente y suele asociarse a alteraciones en la función de la hipófisis anterior. Hay muy pocos casos descritos en la literatura, y suelen observarse además, a lo largo del curso de la enfermedad, no como forma de presentación. Presentamos el caso de una mujer de 22 años afecta de histiocitosis de células de Langerhans cuya forma de debut fue fiebre prolongada e hiperprolactinemia

Langerhan’s cell histiocytosis (LCH) is a rare disorder in which granulomatous deposits occur at multiple sites within the body. The aetiology is unknown. Is more frequent in children. Presenting symptoms are polyuria and polydipsia, due to diabetes insipidus, other symptoms are skin rash, dyspnea and tachypnea. Diagnosis is reached by biopsy of lesions, in which Langerhans cell are found. Prognosis is variable, depending the site affected; therefore, treatment must be individually. The hyperprolactinaemia in LCH is very rare and its related with anterior pituitary deficiency. There are not many cases described, all of them during the course of the disease, not as the onset. We describe a 22 year-old woman with Langerhan’s cell histiocytosis which initial presentation was fever and hyperprolactinaemia

[Fever and hyperprolactinaemia as the onset of Langerhans cell histiocytosis]. / Fiebre e hiperprolactinemia como primera manifestación de histiocitosis de células de Langerhans.

Langerhan's cell histiocytosis (LCH) is a rare disorder in which granulomatous deposits occur at multiple sites within the body. The aetiology is unknown. Is more frequent in children. Presenting symptoms are polyuria and polydipsia, due to diabetes insipidus, other symptoms are skin rash, dyspnea and tachypnea. Diagnosis is reached by biopsy of lesions, in which Langerhan's cell are found. Prognosis is variable, depending the site affected; therefore, treatment must be individually. The hyperprolactinaemia in LCH is very rare and its related with anterior pituitary deficiency. There are not many cases described, all of them during the course of the disease, not as the onset. We describe a 22 year-old woman with Langerhan's cell histiocytosis which initial presentation was fever and hyperprolactinaemia.