Heat stress has divergent effects on the milk microbiota of Holstein and Brown Swiss cows.

Heat stress (HS) is one of the pivotal causes of economic losses in dairy industries and affects welfare and performance, but its effect on milk microbiota remains elusive. It is also unclear if and how different breeds may cope with HS in sustaining productive performance. The objectives of this study were to compare a) the performance of 2 dairy breeds, namely Holstein and Brown Swiss, subjected to HS and b) the different effects of HS on the milk microbiota of the 2 breeds in thermal comfort conditions and HS. The study was carried out on 36 dairy cows, 18 per breed. The HS was induced by switching off the cooling system during a natural heat wave for 4 d. Besides the Temperature Humidity Index (THI), the animal stress was confirmed by measuring respiratory frequency and rectal temperature twice daily at 4 a.m. and 3 p.m. The HS differently impacted the 2 breeds. Rectal temperatures were higher in Holstein cows, while no changes in rectal temperature were found in Brown Swiss. Milk yield recording and sampling were performed during the morning milking of d 1 (at 4.00 a.m.) and afternoon milking of d 4 (at 5.00 p.m.). Productive parameters were also different: milk yield, fat-corrected milk, energy-corrected milk, protein and casein content, and renneting parameters were decreased in Holstein but remained unaffected in Brown Swiss. The HS also modified the milk microbiota of the 2 breeds differently. During HS, the Brown Swiss milk microbiota was richer (α diversity) than the Holstein one. Comparing the time points before and during HS within breeds showed that Brown Swiss milk microbiota was less affected by HS than Holstein's. Under the same thermal comfort condition, milk microbiota did not discriminate between Brown Swiss and Holstein. Consistently with α and ß diversity, the number of operational taxonomic units (OTUs) at the genus level that changed their abundance during HS was higher in Holstein (74 OTUs) than in Brown Swiss (only 20 OTUs). The most significant changes in abundance affected Acinetobacter, Chryseobacterium, Cutibacterium, Enterococcus, Lactococcus, Prevotella-9, Serratia, and Streptococcus. In conclusion, the present report confirms and extends previous studies by demonstrating that Brown Swiss cows regulate their body temperature better than the Holstein breed. The relative thermal tolerance to HS compared with Holstein is also confirmed by changes in milk uncultured microbiota, which were more evident in Holstein than in Brown Swiss.

Involvement of glutathione metabolism in Eichhornia crassipes tolerance to arsenic.

Aquatic macrophytes are potentially useful for phytoremediation programmes in environments contaminated by arsenic (As). Biochemical and physiological modification analyses in different plant parts are important to understand As tolerance mechanisms. The objective was to evaluate glutathione metabolism in leaves and roots of Eichhornia crassipes (Mart.) Solms treated to As. Specimens of E. crassipes were cultured for 3 days in Clark's nutrient solution containing 7 µm As. The enzymes ATP sulphurylase (ATPS), glutathione reductase (GR), glutathione peroxidase (GSH-Px), glutathione sulphotransferase (GST) and γ-glutamylcysteine synthetase (γ-ECS) activity, glutathione content, total protein and non-protein thiols were evaluated. The ATPS activity increased in roots. GR activity in leaves and GSH-Px in roots were lower. GST activity was higher in roots and lower in leaves, and γ-ECS activity was higher in leaves. Glutathione levels were lower, total thiol levels were higher and non-protein levels did not change in E. crassipes leaves and roots. Exposure to As increased enzyme activity involved with sulphur metabolism, such as ATPS. Higher GR activity and lower GSH-Px indicate increased glutathione conjugation to As due to increased GSH availability. The higher GST activity indicates its participation in As detoxification and accumulation through As GSH conjugation. Changes in glutathione and thiol levels suggest high phytochelatin synthesis. In conclusion, the increments in ATPS, GR, GST and γ-ECS activity indicate that these enzymes are involved in GSH metabolism and are part of the E. crassipes As detoxification mechanism.

Nutritional Risk by Mini Nutritional Assessment (MNA), but Not Anthropometric Measurements, Has a Good Discriminatory Power for Identifying Frailty in Elderly People: Data from Brazilian Secondary Care Clinic.

OBJECTIVES: To investigate, in elderly individuals registered at a secondary outpatient clinic, the prevalence of frailty and pre-frailty and to identify the discriminatory power of anthropometric measurements and nutritional risk in identifying these conditions. DESIGN: Cross-sectional study with data extracted from medical records. SETTING AND PARTICIPANTS: Elderly patients (60+ years) from a geriatric outpatient clinic, located in the southeast area of São Paulo, Brazil. MEASUREMENTS: Frailty was assessed using five criteria proposed by Fried et al (2001), with some modifications. Nutritional risk was identified using Mini Nutritional Assessment (MNA). Body weight and body height were measured and used to calculate the body mass index (BMI). The discriminatory power of these parameters for the identification of frailty was determined by Receiver Operating Characteristics (ROC) curves. RESULTS: The final sample was composed of 254 patients, from which 31.1% were identified as frail and 53.5% as prefrail. The MNA indicated that 3.1% were malnourished and 35.4% were at risk of malnutrition. The BMI values 39.4% as overweight/obese and 19.9% as undernourished. As just the MNA revealed differences for frailty classification, only this parameter was investigated by ROC curve. The discriminatory power of the MNA for frailty presented a best cut-off point of ≤23.0 and the AUC was 0.812 (sensitivity=55.7; specificity=94.9), with a youden index of 0.5057 (95%CI= 0.3146-0.5946). MNA did not present sufficient discriminatory power to detect pre-frailty. CONCLUSION: The MNA was capable of indicating frailty, but not pre-frailty in this sample. BMI did not display significant predictive power for frailty or pre-frailty.

A Single Bout of Arm-crank Exercise Promotes Positive Emotions and Post-Exercise Hypotension in Patients with Symptomatic Peripheral Artery Disease.

OBJECTIVE/BACKGROUND: The objective was to analyze the acute effects of a single bout of arm cranking exercise on affective and cardiovascular parameters in patients with symptomatic peripheral artery disease (PAD). METHODS: This was a prospective, controlled, crossover study. Eleven men with symptomatic PAD underwent two experimental sessions in a random order: control or arm crank exercise (15 × 2 minutes bouts of arm crank exercise interrupted by 2 minutes rest intervals). During exercise, ratings of perceived exertion (Borg scale) and affective responses (pleasure/displeasure) were obtained at the first, fifth, tenth, and fifteenth bouts. Before and after the experimental sessions, cardiovascular parameters (blood pressure and heart rate) were obtained. Data were analysed by a two-way repeated measure analysis of variance with significance achieved at p < .05. RESULTS: During the arm crank exercise, patients reported positive feelings of pleasure. During exercise, heart rate (HR) remained within 80-90% of peak HR. Additionally, patients performed arm crank exercise with moderate levels of perceived exertion (Borg rating of 11-13) and with pleasant affective scores (Feeling Scale of +1 to +5). Blood pressure (systolic, diastolic, and mean) increase was lower after arm crank exercise than for control (greatest net effect: -15 ± 11 mmHg [p < .001]; -9 ± 5 mmHg [p < .001]; -9 ± 6 mmHg [p < .001], respectively), while HR increased (greatest net effect: +9 ± 6 beats per minute; p < .001). CONCLUSION: A single bout of arm crank exercise promotes pleasurable feelings while reducing blood pressure in patients with symptomatic PAD.

Effect of 3-nitrooxypropanol on methane and hydrogen emissions, methane isotopic signature, and ruminal fermentation in dairy cows.

The objective of this crossover experiment was to investigate the effect of a methane inhibitor, 3-nitrooxypropanol (3NOP), on enteric methane emission, methane isotopic composition, and rumen fermentation and microbial profile in lactating dairy cows. The experiment involved 6 ruminally cannulated late-lactation Holstein cows assigned to 2 treatments: control and 3NOP (60 mg/kg of feed dry matter). Compared with the control, 3NOP decreased methane emission by 31% and increased hydrogen emission from undetectable to 1.33 g/d. Methane emissions per kilogram of dry matter intake and milk yield were also decreased 34% by 3NOP. Milk production and composition were not affected by 3NOP, except milk fat concentration was increased compared with the control. Concentrations of total VFA and propionate in ruminal fluid were not affected by treatment, but acetate concentration tended to be lower and acetate-to-propionate ratio was lower for 3NOP compared with the control. The 3NOP decreased the molar proportion of acetate and increase those of propionate, butyrate, valerate, and isovalerate. Deuterium-to-hydrogen ratios of methane and the abundance of (13)CH3D were similar between treatments. Compared with the control, minor (4‰) depletion in the (13)C/(12)C ratio was observed for 3NOP. Genus composition of methanogenic archaea (Methanobrevibacter, Methanosphaera, and Methanomicrobium) was not affected by 3NOP, but the proportion of methanogens in the total cell counts tended to be decreased by 3NOP. Prevotella spp., the predominant bacterial genus in ruminal contents in this experiment, was also not affected by 3NOP. Compared with the control, Ruminococcus and Clostridium spp. were decreased and Butyrivibrio spp. was increased by 3NOP. This experiment demonstrated that a substantial inhibition of enteric methane emission by 3NOP in dairy cows was accompanied with increased hydrogen emission and decreased acetate-to-propionate ratio; however, neither an effect on rumen archaeal community composition nor a significant change in the isotope composition of methane was observed.

Sport modality affects bradycardia level and its mechanisms of control in professional athletes.

We investigated the influence of sport modalities in resting bradycardia and its mechanisms of control in highly trained athletes. In addition, the relationships between bradycardia mechanisms and cardiac structural adaptations were tested. Professional male athletes (13 runners, 11 cyclists) were evaluated. Heart rate (HR) was recorded at rest on beat-to-beat basis (ECG). Selective pharmacological blockade was performed with atropine and esmolol. Vagal effect, intrinsic heart rate (IHR), parasympathetic (n) and sympathetic (m) modulations, autonomic influence (AI) and autonomic balance (Abal) were calculated. Plasmatic norepinephrine (high-pressure liquid chromatography) and cardiac structural adaptations (echocardiography) were evaluated. Runners presented lower resting HR, higher vagal effect, parasympathetic modulation (n), AI and IHR than cyclists (P<0.05). Abal, sympathetic modulation (m) and norepinephrine level were similar within athletes regardless of modality. The cardiac chambers were also similar between runners and cyclists (P=0.30). However, cyclists displayed higher septum and posterior wall thickness than runners (P=0.04). Further analysis showed a trend towards inverse correlation between IHR with septum wall thickness and posterior wall thickness (P=0.056). Type of sport influences the resting bradycardia level and its mechanisms of control in professional athletes. Resting bradycardia in runners is mainly dependent on an autonomic mechanism. In contrast, a cyclist's resting bradycardia relies on a non-autonomic mechanism probably associated with combined eccentric and concentric hypertrophy.

Pectoralis major myocutaneous flap for head and neck reconstruction: risk factors for fistula formation.

The pectoralis major myocutaneous flap (PMMF) is a safe and versatile flap used widely for head and neck cancer reconstructions, but one of the major and most feared complications is oro- or pharyngocutaneous fistula. Herein, we attempt to establish risk factors for fistula formation in reconstructions of mucosal defects in the head and neck using PMMF through retrospective analysis of PMMF performed during 3 years at a single institution, with a total of 84 procedures. There were 69 men and 15 women, with a mean age of 59.5 years. There were 15 cases of partial flap loss, two total flap losses and 31 fistulas. The independent risk factors for fistula formation were preoperative serum hemoglobin < 13 g/dl, preoperative serum albumin < 3.4 g/dl and hypopharynx reconstruction. The PMMF is still a very useful flap and this is the first multivariate analysis analysing risk factors for fistula formation. These findings are helpful in selecting patients with elevated risk of fistula formation, and therefore preventive measures can be undertaken to avoid potentially serious complications.