Assessment of regional myocardial blood flow and regional fractional oxygen extraction in dogs, using 15O-water and 15O-hemoglobin

A new approach to the assessment of regional myocardial blood flow and fractional oxygen extraction has been developed using 15O-water (H2- 15O) and 15O-hemoglobin (15O-Hb). Bolus doses (1 mCi) of H2-15O and 15O- Hb were injected 10 minutes apart into the left main coronary artery of 12 normal dogs. Sequential images of regional myocardial tracer clearance were obtained over 5 minutes with a positron camera. Myocardial blood flow calculated from the monoexponential washout of H2- 15O after background correction was 78 +/- 6 (SE) ml/100 g per min. Functional images of regional blood flow in which the image of peak activity was divided by the integrated image of H2-15O washout were derived by computer processing. These images demonstrated homogeneous blood flow in the normal myocardium. Fractional myocardial O2 extraction was determined from an image of initial distribution of O2 used (obtained by extrapolating back to time zero the series of images obtained after 15O-Hb administration), divided by initial distribution of O2 delivered (obtained by back extrapolating H2-15O washout). These functional images showed uniform distribution of fractional O2 extraction in the normal myocardium. Thus, these studies show that regional myocardial blood flow and regional oxygen extraction can be measured simultaneously by sequential imaging after serial intracoronary injections of H2-15O and 15O-Hb

Nanopore direct RNA sequencing maps the complexity of Arabidopsis mRNA processing and m6A modification

Understanding genome organization and gene regulation requires insight into RNA transcription, processing and modification. We adapted nanopore direct RNA sequencing to examine RNA from a wild-type accession of the model plant Arabidopsis thaliana and a mutant defective in mRNA methylation (m6A). Here we show that m6A can be mapped in full-length mRNAs transcriptome-wide and reveal the combinatorial diversity of cap-associated transcription start sites, splicing events, poly(A) site choice and poly(A) tail length. Loss of m6A from 3’ untranslated regions is associated with decreased relative transcript abundance and defective RNA 30 end formation. A functional consequence of disrupted m6A is a lengthening of the circadian period. We conclude that nanopore direct RNA sequencing can reveal the complexity of mRNA processing and modification in full-length single molecule reads. These findings can refine Arabidopsis genome annotation. Further, applying this approach to less well-studied species could transform our understanding of what their genomes encode

Antioxidant therapy mitigates summer-induced DNA damage in boar spermatozoa

Introduction: While pork is the most widely eaten meat in the world, pig production is continually threatened by changing climate conditions resulting in poor reproductive performance, particularly in the tropics. The boar's inefficient capacity to sweat; non-pendulous scrotum and high susceptibility of boar sperm to temperature shock makes this species particularly vulnerable to the effects of heat stress. While DNA-damaged sperm may fertilize normally, key genes involved in early embryo development may be severely affected inducing early embryo loss as shown in the mice. Our study demonstrates that tropical summer significantly increases DNA damage in populations of sperm within the ejaculate without necessarily affecting sperm motility. Moreover, supplementing boars with antioxidants during summer could potentially reduce the negative impact of heat stress on sperm DNA integrity. Materials and Methods: Five mature Large White boars were housed individually in open gable pens at JCU in the dry tropics of Townsville, Queensland, Australia. Semen was collected by the gloved-hand technique using a dummy sow during spring (Oct 2014), summer (Feb 2015) & early winter (end May 2015) and diluted 1:3 in BTS media. Boar feed was supplemented with 100g/boar/day custom-made antioxidant formulation during summer (Jan - Apr 2016) and semen was collected after 42 & 84 days treatment. Sperm concentration was determined by haemocytometer and motility of 20 x 106 sperm/ml at 38°C was analyzed using CASA (Hamilton Thorne). Sperm DNA damage in 20,000 Percoll-purified sperm per boar per treatment was evaluated using TUNEL (Roche) & flow cytometry (Dako Cytomation; Fig. 1). Results: Sperm motility was similar in summer to winter & spring (P > 0.05) but total motility was lower in spring than winter (P ≤ 0.05). Antioxidant supplementation for 42 & 84 days during summer did not affect motility of spermatozoa (P > 0.05). Sperm DNA damage was more than 16-fold higher in summer than winter & nearly 9-fold higher than spring (P ≤ 0.05; Fig. 2). Antioxidant supplementation during summer reduced sperm DNA damage after 42 & 84 days antioxidant treatment (P ≤ 0.05; Fig. 3). Conclusions and discussion: Sperm DNA integrity is compromised in boars during summer, suggesting boar factors may contribute to embryo loss in sows. Moreover, such damage appears undetectable using traditional measures of sperm motility. Antioxidant therapy during summer appears to significantly alleviate heat stress-induced DNA damage in boar sperm, which may provide one solution to the problem of summer infertility in the pig

Tropical summer induces sperm DNA damage in boars which can be mitigated by antioxidant therapy

Summer infertility due to heat stress grossly affects reproductive performance in pigs, particularly in the tropics, and causes over $300 million in annual losses to the US swine industry. Boar's inefficient capacity to sweat; non-pendulous scrotum and the high susceptibility of boar sperm to temperature shock makes this species particularly vulnerable to heat stress. While traditionally considered a sow problem, recent studies demonstrate that heat stress-induced sperm DNA damage can result in early embryo loss in mice. Our study aimed to demonstrate higher sperm DNA damage during summer in boars and trial antioxidant therapy to alleviate the problem. Motility of sperm obtained from n=5 Large White boars housed in the dry tropics of Townsville, North Queensland, Australia was characterized by Computer-Assisted Sperm Analysis (CASA), but did not differ between spring, summer and winter (total motility: 70.8 ± 5.5% vs. 71.3 ± 8.1% vs. 90.2 ± 4.2%; progressive motility: 41.7 ± 2.8% vs. 35.4 ± 7.0% vs. 46.6 ± 4.0% respectively, both P ≥ 0.05). However, sperm DNA integrity in twenty-thousand spermatozoa per boar per treatment, evaluated using TUNEL staining and flow cytometry, revealed nearly 9-fold higher DNA damage in summer than spring and winter (16.1 ± 4.8% vs. 1.8 ± 0.5% vs 1.1 ± 0.2% respectively; P ≤ 0.05). However, boar feed supplemented with antioxidants during summer significantly reduced sperm DNA damage to 9.9 ± 4.5% and 7.2 ± 1.6% (P ≤ 0.05) after 42 and 84 days treatment respectively. Total and progressive motility were not altered by the supplement. Our results show sperm DNA integrity is compromised in boars during summer, suggesting boar factors may contribute to embryo loss in sows. Moreover, such damage may go undetected using traditional measures of sperm motility. Antioxidant supplementation during summer alleviates the negative impact of heat stress on sperm DNA integrity

Boar sperm DNA damage induced by tropical heat stress can be alleviated using antioxidants

Seasonal heat stress is known to significantly diminish reproductive performance in pigs, particularly in the tropics, costing the industry millions in annual loses. The boar's reduced capacity to sweat, non-pendulous scrotum, and widespread use of European breeds in the tropics, makes this species particularly vulnerable to heat stress. While traditionally considered a sow problem, recent mouse studies demonstrate that heat stress-induced sperm DNA damage can result in arrested development and loss of early embryos. Our study investigated the impact of tropical summer heat stress on the quality and DNA integrity of boar sperm, and trialled antioxidant supplementation to alleviate the problem. Motility of sperm obtained from n = 5 Large White boars housed in the dry tropics of Townsville, North Queensland, Australia was characterized by Computer-Assisted Sperm Analysis but did not differ between summer, winter or spring (total motility: 71.3 ± 8.1 vs. 90.2 ± 4.2 vs. 70.8 ± 5.5% respectively, P > 0.05; progressive motility: 35.4 ± 7.0 vs. 46.6 ± 4.0 vs. 41.7 ± 2.8% respectively, P > 0.05). Sperm DNA integrity in 20,000 sperm/boar/season, evaluated using TUNEL and flow cytometry, revealed 16-fold more DNA damaged sperm in summer than winter, and nearly 9-fold more than spring (16.1 ± 4.8 vs. 1.0 ± 0.2 vs. 1.9 ± 0.5% respectively, P ≤ 0.05). However, boar feed supplemented with 100g/boar/day of proprietary custom-made antioxidants during summer significantly reduced sperm DNA damage to 9.9 ± 4.5% and 7.2 ± 1.6% (P ≤ 0.05) after 42 and 84 days treatment respectively. Total and progressive motility were not altered by the supplement. In summary, sperm DNA integrity is compromised in boars during summer, suggesting boar factors may contribute to seasonal embryo loss in sows. Moreover, such damage appears undetectable using traditional measures of sperm motility. Antioxidant supplementation during summer appears to mitigate the negative impact of heat stress on sperm DNA integrity

Ghrelin antagonist overrides the mRNA expression of NPY in hypothalamus in feed restricted ewes

A negative energy balance (NEB) is detrimental to reproduction in animals. A suggested link between NEB and reproductive failure is the gastrointestinal hormone ghrelin, because of the association between ghrelin and the hypothalamo-pituitary-gonadal axis. The [D-Lys3]-Growth Hormone Releasing Peptide-6 ([D-Lys3]-GHRP-6) is a ghrelin antagonist that acts on ghrelin receptors (GHS-R1). The objective of this study was to evaluate the effect of [D-Lys3]-GHRP-6 on reproduction variables in feed restricted ewes. Two experiments were conducted. Experiment I was conducted for 30 days; and Experiment II for 13 days. In both experiments the ewes (n = 18) were randomly assigned to: Control (CO): fed to meet maintenance requirements; Feed restriction (FR): 80% of maintenance restriction; or Ghrelin antagonist (GA): feed restricted and daily subcutaneous of 7.5μg/kg of [D-Lys3]-GHRP-6. Plasma was collected to measure hormones and metabolite concentration. In Experiment II, the hypothalamus and ovaries were collected on day 13. In both Experiments, sheep allocated to the FR and GA treatments decreased their body weight compared with sheep in the CO group (P 0.10). Experiment I: Plasma ghrelin concentration was greater (P < 0.01) in FR and GA compared with CO ewes. Plasma non-esterified fatty acids concentration was greater (P < 0.01) in GA and FR than CO. Experiment II: Kisspeptin1-Receptor (Kiss1-R) mRNA expression was greater in FR (P < 0.01) and tended to be greater in GA (P = 0.10) compared with CO ewes. The neuro peptide-Y (NPY) mRNA expression was greater (P = 0.03) in FR than CO; and tended to be greater (P = 0.06) compared with GA ewes. Growth hormone releasing hormone (GhRH) mRNA expression was greater in GA (P = 0.04) and tended to be greater in FR (P = 0.07) compared with CO ewes. Feed restriction increased GhRH, NPY, and Kiss-R mRNA expression in hypothalamus without affecting reproductive variables.Ghrelin antagonist may prevent an increase inNPY expression in ewes.Fil: Carranza Martin, Ana Cristina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico CONICET- La Plata. Instituto de Genética Veterinaria "Ing. Fernando Noel Dulout". Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias. Instituto de Genética Veterinaria; Argentina. Ohio State University; Estados UnidosFil: Parker, Anthony J.. Ohio State University; Estados UnidosFil: Furnus, Cecilia Cristina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico CONICET- La Plata. Instituto de Genética Veterinaria "Ing. Fernando Noel Dulout". Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias. Instituto de Genética Veterinaria; ArgentinaFil: Relling, Alejandro Enrique. Ohio State University; Estados Unido

Correlation between ankle-brachial index, symptoms, and health-related quality of life in patients with peripheral vascular disease

AbstractObjectiveImproving health-related quality of life (HRQL) is the main goal of surgery to treat peripheral vascular disease (PVD); however, HRQL is rarely measured directly. Rather, most surgeons use other measures, such as patient symptoms and ankle-brachial index (ABI) to determine the need for intervention in PVD. The accuracy of these surrogates in representing HRQL has been untested. The purpose of this study was to determine the correlation of these measures with HRQL in patients undergoing evaluation for intervention in symptomatic PVD.MethodsPatients (n = 108) referred to the vascular surgery service with symptoms of PVD were enrolled in a prospective study of HRQL. Patients completed two validated HRQL questionnaires: the short form-36 (SF-36) and the Walking Impairment Questionnaire (WIQ). All patients had symptoms consistent with PVD, including claudication (n = 69; 63.9%), ischemic rest pain (n = 17; 15.7%), or tissue loss (n = 22; 20.4%). ABI was measured at presentation.ResultsThe mean ABI was 0.53 (range, 0.00-0.98). The maximal correlation between SF-36 score and ABI was reflected in the Physical Component Summary score (r = 0.25). WIQ score also exhibited modest correlation with ABI, with maximal correlation noted for stair climbing (r = 0.26). Both SF-36 and WIQ scores exhibited a highly significant association with symptoms. Patients with more severe symptoms, such as lifestyle-limiting claudication or limb-threatening ischemia, had lower HRQL scores compared with patients with non-lifestyle-limiting claudication. Multivariate analysis demonstrated that SF-36 and WIQ physical summary scores are better predicted by symptoms than by ABI (P < .01).ConclusionsHRQL in patients with PVD correlates weakly with ABI, but exhibits a closer association with vascular symptoms. However, neither variable fully expresses patient HRQL. These data suggest that sole reliance on these surrogates may not accurately reflect the effect of PVD on HRQL, or the potential benefit of vascular surgery in improving HRQL

Role of Doctoral Studies on the Relationships Between Select Doctoral Students and Their Partners: A Collective Case Study

Students who enter post-baccalaureate studies face numerable challenges during their tenure in graduate school. Although researchers have studied these inherent challenges, a gap exists in the literature concerning doctoral students and the impact of their studies on their personal relationships. As such, the purpose of this collective case study was to examine the effect that doctoral studies have on the relationships between select doctoral students and their partners. Semi-structured interviews of six participants, selected via convenience sampling (i.e., current doctoral students who have been in relationships during their doctoral studies), generated data concerning challenges, coping mechanisms, personal emotions, and relationship concerns. These findings provided a composite understanding of the potential inherent struggles of doctoral students and the corresponding role that their doctoral studies have on the relationships of these specific doctoral students and their partners that matched much of the findings noted in the literature. It is the researchers’ hope that the results will help guide future researchers but urge caution concerning the generalizability of the information gained from this study due to its small sample size

Mechanisms of pulsus paradoxus during resistive respiratory loading and asthma

To determine the mechanisms of pulsus paradoxus during asthma, six subjects known to have cold air bronchial hyperreactivity were studied while in a quiescent phase of their disease. All were free of significant airway obstruction at the time of study. After placement of an esophageal balloon to estimate intrathoracic pressure, the subjects were assessed during quiet breathing, resistive airway loading and then during a stable period of airway obstruction induced by cold air. Steady state left ventricular volume and performance were measured using radionuclide ventriculography; right ventricular volume was calculated from the stroke volume ratio and right ventricular ejection fraction. Cardiac cycles were segregated according to their occurrence in inspiration or expiration using a flow signal from a pneumotachograph.Combined inspiratory and expiratory resistance produced pulsus paradoxus and changes in esophageal pressure that were similar to those during asthma and significantly greater than those during quiet breathing. These changes were accompanied by decreases in left ventricular diastolic volume and stroke volume during inspiration, and increases in these variables during expiration; right ventricular volume and stroke volume demonstrated changes reciprocal to those seen in the left ventricle. These data indicate that during periods of increase in airway resistance, abnormal pulsus paradoxus results from an exaggeration in the normal inspiratory-expiratory difference in stroke volume mediated primarily by the effects of intrathoracic pressure on ventricular preload

Trace amine receptor in GtoPdb v.2023.1

Trace amine-associated receptors were discovered from a search for novel 5-HT receptors [9], where 15 mammalian orthologues were identified and divided into two families. The TA1 receptor (nomenclature as agreed by the NC-IUPHAR Subcommittee for the Trace amine receptor [58]) has affinity for the endogenous trace amines tyramine, &#946;-phenylethylamine and octopamine in addition to the classical amine dopamine [9]. Emerging evidence suggests that TA1 is a modulator of monoaminergic activity in the brain [94] with TA1 and dopamine D2 receptors shown to form constitutive heterodimers when co-expressed [30]. In addition to trace amines, receptors can be activated by amphetamine-like psychostimulants, and endogenous thyronamines