Development and validation of a prognostic index (BODEXS90) for mortality in stable chronic obstructive pulmonary disease.

INTRODUCTION: Several multidimensional indices have been proposed to predict mortality in chronic obstructive pulmonary disease (COPD). The BODEX index is simple and easy to use for this purpose in all clinical settings. Only a few prognostic indices have integrated oxygenation variables, with measurement methods that are not practical for real life clinical practice in all settings. OBJECTIVES: To develop and externally validate a new prognostic index (BODEXS90) that combines the variables included in BODEX index with rest peripheral oxygen saturation measured with finger oximetry (SpO2) to predict all-cause mortality in stable COPD. METHOD: Observational, non-intervention, multicenter historic cohort study. The BODEXS90 index was developed in a derivation cohort and externally validated in a validation cohort. Calibration of the index was carried out using Hosmer-Lemeshow test. The discrimination capacity of BODEXS90 and BODEX were compared by means of receiver-operating characteristics curves. Modelling of the index was carried out by crude and adjusted Cox regression analysis. RESULTS: The derivation and validation cohorts included 787 and 1179 subjects, respectively. SpO2 predicted all cause-mortality independently of BODEX index. Discrimination capacity of BODEXS90 to predict the outcome was significantly higher than that of BODEX, particularly for more severely affected patients, both in the derivation and in the validation cohorts. CONCLUSIONS: The new index is potentially useful for designing clinical decision-making algorithms in stable COPD.

Patients' perspectives on point-of-care diagnostics and treatment by emergency medical technicians in acute COPD exacerbations: A qualitative study.

BACKGROUND: In Denmark emergency medical technicians transport patients with acute COPD exacerbations to the nearest emergency department. From a clinical and economic perspective, this transport and assessment at the hospital may be inconvenient if the patient is immediately discharged from the emergency department. We established an emergency technical technicians point-of-care diagnostics and treatment program of patients with COPD with use of ultrasound and blood analysis. Patients' perspectives on treatment at home and sense of security are important to qualify clinical practice at home with patients with acute exacerbation. AIM AND OBJECTIVES: To explore patient's and relatives' experience of treatment at home during emergency calls due to COPD in exacerbation and to investigate their attitude to avoid hospitalization as well as experience of stress during point-of-care diagnostics in their own home. METHOD: A qualitative study comprising semi-structured interviews with 16 patients carried out from April 1st, 2019 to March 31st, 2020 in Denmark. Data was analysed inspired by Malteruds' text condensation and informed by Critical Psychology with first person perspective focusing on the patient's views on point-of-care diagnostics and treatment of their COPD in acute exacerbation. RESULTS: The interviews revealed that in order to ensure an experience of quality in the assessment and treatment of patients in their own homes, it was important that the ambulance staff showed great safety and experience in the use of the technical equipment and treatment of dyspnea. It was also of importance that the patients felt confident that their general practitioner followed up on the home treatment initiated. CONCLUSION: Patients' perspectives showed that point-of-care diagnostics and treatment of acute COPD in exacerbation was considered a qualitative offer by the patients and their relatives. At the same time, it was crucial that the emergency medical technicians showed experience and safety in handling shortness of breath as well as the technical equipment. TRIAL REGISTRATION: Approved by the Danish Data Protection Agency Project-ID: 20/24845.

Comparison of temperature and doping dependence of elastoresistivity near a putative nematic quantum critical point.

Strong electronic nematic fluctuations have been discovered near optimal doping for several families of Fe-based superconductors, motivating the search for a possible link between these fluctuations, nematic quantum criticality, and high temperature superconductivity. Here we probe a key prediction of quantum criticality, namely power-law dependence of the associated nematic susceptibility as a function of composition and temperature approaching the compositionally tuned putative quantum critical point. To probe the 'bare' quantum critical point requires suppression of the superconducting state, which we achieve by using large magnetic fields, up to 45 T, while performing elastoresistivity measurements to follow the nematic susceptibility. We performed these measurements for the prototypical electron-doped pnictide, Ba(Fe1-xCox)2As2, over a dense comb of dopings. We find that close to the putative quantum critical point, the elastoresistivity appears to obey power-law behavior as a function of composition over almost a decade of variation in composition. Paradoxically, however, we also find that the temperature dependence for compositions close to the critical value cannot be described by a single power law.

Automated summative feedback improves performance and retention in simulation training of mastoidectomy: a randomised controlled trial.

OBJECTIVE: This study aimed to investigate the effects of automated metrics-based summative feedback on performance, retention and cognitive load in distributed virtual reality simulation training of mastoidectomy. METHOD: Twenty-four medical students were randomised in two groups and performed 15 mastoidectomies on a distributed virtual reality simulator as practice. The intervention group received additional summative metrics-based feedback; the control group followed standard instructions. Two to three months after training, participants performed a retention test without learning supports. RESULTS: The intervention group had a better final-product score (mean difference = 1.0 points; p = 0.001) and metrics-based score (mean difference = 12.7; p < 0.001). At retention, the metrics-based score for the intervention group remained superior (mean difference = 6.9 per cent; p = 0.02). Also at the retention, cognitive load was higher in the intervention group (mean difference = 10.0 per cent; p < 0.001). CONCLUSION: Summative metrics-based feedback improved performance and lead to a safer and faster performance compared with standard instructions and seems a valuable educational tool in the early acquisition of temporal bone skills.

Discordancia del tratamiento de la enfermedad pulmonar obstructiva crónica según la guía GesEPOC vs. GOLD / Discordance in treatment of chronic obstructive pulmonary disease following GesEPOC Guideline vs. GOLD

Introducción En España, el tratamiento farmacológico de la enfermedad pulmonar obstructiva crónica se basa en la Global Initiative for Chronic Obstructive Lung Disease (GOLD) y la Guía española de la enfermedad pulmonar obstructiva crónica (GesEPOC). El objetivo principal de este estudio fue evaluar la concordancia entre los tratamientos de inicio asignados por GOLD y GesEPOC. Material y métodos Estudio de simulación. Se emplearon las siguientes variables: FEV1%, exacerbaciones, disnea inicial, eosinofilia en sangre, antecedente de asma y grado de reversibilidad en la prueba broncodilatadora. Cuatro neumólogos clasificaron/asignaron un tratamiento a cada paciente (2 de ellos según GOLD y 2 según GesEPOC). Se calculó el coeficiente Kappa de Cohen global. Resultados Se incluyeron 467 pacientes. La concordancia entre el tratamiento recomendado por GOLD y GesEPOC fue pobre (Kappa: 0,17, IC 95%: 0,12-0,23). Conclusión Existe una pobre concordancia entre GOLD y GesEPOC a la hora de iniciar tratamiento en los pacientes con enfermedad pulmonar obstructiva crónica (AU)

Introduction Pharmacological treatment of chronic obstructive pulmonary disease in Spain is usually chosen according to the Global Initiative for Chronic Obstructive Lung Disease (GOLD) or Spanish guidelines for chronic obstructive pulmonary disease (GesEPOC). The main objective of this study was to evaluate the degree of concordance between treatment for newly diagnosed chronic obstructive pulmonary disease patients according to GOLD and GesEPOC. Material and methods Simulation study. The following variables were used: FEV1%, exacerbations, dyspnoea at first evaluation, blood eosinophilia, personal history of asthma, and degree of bronchodilator reversibility. Four investigators classified and assigned a treatment to each patient (2 using GOLD criteria and the other 2 using GesEPOC). Global Kappa index was calculated. Results The database included 467 patients. Agreement between treatment decided using GOLD and GesEPOC was poor (Kappa: 0.17, 95% CI: 0.12-0.23). Conclusion There is a poor agreement between GOLD and GesEPOC recommendations for initial chronic obstructive pulmonary disease treatment (AU)

Discordance in treatment of chronic obstructive pulmonary disease following GesEPOC guideline vs. GOLD.

INTRODUCTION: Pharmacological treatment of chronic obstructive pulmonary disease in Spain is usually chosen according to the Global Initiative for Chronic Obstructive Lung Disease (GOLD) or Spanish guidelines for chronic obstructive pulmonary disease (GesEPOC). The main objective of this study was to evaluate the degree of concordance between treatment for newly diagnosed chronic obstructive pulmonary disease patients according to GOLD and GesEPOC. MATERIAL AND METHODS: Simulation study. The following variables were used: FEV1%, exacerbations, dyspnoea at first evaluation, blood eosinophilia, personal history of asthma, and degree of bronchodilator reversibility. Four investigators classified and assigned a treatment to each patient (2 using GOLD criteria and the other 2 using GesEPOC). Global Kappa index was calculated. RESULTS: The database included 467 patients. Agreement between treatment decided using GOLD and GesEPOC was poor (Kappa: 0.17, 95% CI: 0.12-0.23). CONCLUSION: There is a poor agreement between GOLD and GesEPOC recommendations for initial chronic obstructive pulmonary disease treatment.

Review: Feed residues of glyphosate - potential consequences for livestock health and productivity.

Glyphosate is the active ingredient in a wide range of herbicides used for weed control, including weed control in genetically modified, glyphosate-insensitive crops. In addition, glyphosate herbicides are used for pre-harvest desiccation of glyphosate-sensitive crops. Together, the use of glyphosate leads to residues in livestock feed. In addition to its herbicidal property, glyphosate has documented antimicrobial and mineral-chelating properties. The aim of the present paper is to address, based on the published literature and own observations, whether dietary glyphosate residues may affect livestock gut microbiota and/or mineral status potentially with derived unfavourable effects on animal health and productivity. However, and as reported, literature on the potential effects of glyphosate on livestock is very scarce and mainly reporting in vitro studies; hence, a solid basis of in vivo studies with livestock in physiological and productive phases, particularly sensitive to disorders in mineral status and in the gut microbiota, is needed for drawing final conclusions.

Targeted next-generation sequencing of adult gliomas for retrospective prognostic evaluation and up-front diagnostics.

AIMS: We aimed to reclassify a population-based cohort of 529 adult glioma patients to evaluate the prognostic impact of the 2016 World Health Organization (WHO) central nervous system tumour classification. Moreover, we evaluated the feasibility of gene panel next-generation sequencing (NGS) in daily diagnostics of 225 prospective glioma patients. METHODS: The retrospective cohort was reclassified according to WHO 2016 criteria by immunohistochemistry for IDH-R132H, fluorescence in situ hybridization for 1p/19q-codeletion and gene panel NGS. All tumours of the prospective cohort were subjected to NGS analysis up-front. RESULTS: The entire population-based cohort was successfully reclassified according to WHO 2016 criteria. NGS results were obtained for 98% of the prospective patients. Survival analyses in the population-based cohort confirmed three major prognostic subgroups, that is, isocitrate dehydrogenase (IDH)-mutant and 1p/19q-codeleted oligodendrogliomas, IDH-mutant astrocytomas and IDH-wildtype glioblastomas. The distinction between WHO grade II and III was prognostic in patients with IDH-mutant astrocytoma. The survival of patients with IDH-wildtype diffuse astrocytomas carrying TERT promoter mutation and/or EGFR amplification overlapped with the poor survival of IDH-wildtype glioblastoma patients. CONCLUSIONS: Gene panel NGS proved feasible in daily diagnostics. In addition, our study confirms the prognostic role of glioma classification according to WHO 2016 in a large population-based cohort. Molecular features of glioblastoma in IDH-wildtype diffuse glioma were linked to poor survival corresponding to IDH-wildtype glioblastoma patients. The distinction between WHO grade II and III retained prognostic significance in patients with IDH-mutant diffuse astrocytic gliomas.

Injection of freshly collected autologous adipose tissue into non-healing wounds after closed incision pilonidal surgery.

BACKGROUND: Chronic non-healing wounds are a major problem after closed incision pilonidal surgery. Freshly collected autologous adipose tissue injected into perianal fistulas in patients with Crohn's disease seems to promote healing. We investigated this technique in patients with non-healing wounds after cleft-lift surgery for pilonidal sinus disease (PSD). METHOD: In a prospective interventional pilot study conducted at our institution autologous adipose tissue from the abdominal wall was harvested, and injected into chronic non-healing PS wounds after surgical revision, healing rate being the primary outcome. The wounds were left open. Patients were followed every 2 to 3 weeks until complete healing (skin coverage, no undermining). RESULTS: 7 male patients were included (mean age 24 ± 0,6 SD years) and complete healing was achieved in 6 patients (86%). Median time to healing was 90 days (range 36-403 days ) and mean follow-up time was 388± 45 days. All patients reported major symptom relief shortly after the procedure. The mean operation time was 80 ± 23 minutes and the mean amount of freshly collected adipose tissue injected was 27.4± 12 ml. There were no complications. CONCLUSIONS: Freshly collected autologous adipose tissue injected into chronic non-healing pilonidal wounds seems safe and efficient.

Pneumococcal antibody protection in patients with autoimmune inflammatory rheumatic diseases with varying vaccination status.

Objectives: The aims of this cross-sectional study were to assess the pneumococcal antibody coverage in patients with autoimmune inflammatory rheumatic disease (AIRD) and to identify predictors associated with inadequate protective antibody levels. Method: Antibodies to 12 serotypes occurring in the commonly applied pneumococcal vaccines in Denmark were measured in AIRD patients with a diagnosis of rheumatoid arthritis, spondyloarthritis, or psoriatic arthritis attending the Department of Rheumatology at the North Denmark Regional Hospital. Immunization against pneumococcal infection was defined as a geometric mean level ≥ 1 µg antibodies/mL. Clinical information about vaccination status and disease/treatment history was retrieved from the medical file system. Results: Results of antibody measurement and vaccination status were available from 346 AIRD patients, of whom 200 (58%) were registered as receiving pneumococcal vaccination, whereas the remaining 146 patients (42%) were not. Of all 346 patients, only 61 (18%) were measured with an adequate level of protective antibodies (30% vs 1%, respectively). Methotrexate treatment at the time of vaccination and increasing age were identified as predictors of poor vaccination outcome in multiple logistic regression analysis. Conclusions: This post-vaccination study showed that less than one-fifth of the AIRD patients are adequately protected against pneumococcal infection, although the immunization programme had been implemented in more than half of the study population. Development of improved vaccination strategies is required to achieve a higher immunization coverage rate and more efficient lasting antibody response.

Adhesive bowel obstruction: Incidence, recurrence and 30-day mortality in Danish women 1984-2013 - A national cohort study.

BACKGROUND: Adhesive bowel obstruction is a serious complication to abdominal surgery. It is unknown whether incidence and mortality rates have changed as new surgical procedures were introduced. METHODS: In a nationwide cohort of Danish women from 1984 to 2013, incidence of adhesive bowel obstruction and 30 days mortality were presented as standardized rates. Impact of treatment was analyzed by Cox regression and recurrent disease characterized by Kaplan Meyer estimates. RESULTS: Incidence of adhesive bowel obstruction increased 50% among women with no prior abdominal surgery. These women had 3-5 times lower incidence than those with a surgical record. 30-day mortality rate was 13%, highest in patients treated non-operatively. The mortality declined in recent years. Recurrent disease had lower mortality rates compared to the first episode. CONCLUSIONS: The incidence of adhesive bowel obstruction increased during the last 30 years, mortality after the first episode is high, while recurrent disease shows declining mortality rates.

Potential of milk mid-infrared spectra to predict nitrogen use efficiency of individual dairy cows in early lactation.

Improving nitrogen use efficiency (NUE) at both the individual cow and the herd level has become a key target in dairy production systems, for both environmental and economic reasons. Cost-effective and large-scale phenotyping methods are required to improve NUE through genetic selection and by feeding and management strategies. The aim of this study was to evaluate the possibility of using mid-infrared (MIR) spectra of milk to predict individual dairy cow NUE during early lactation. Data were collected from 129 Holstein cows, from calving until 50 d in milk, in 3 research herds (Denmark, Ireland, and the UK). In 2 of the herds, diets were designed to challenge cows metabolically, whereas a diet reflecting local management practices was offered in the third herd. Nitrogen intake (kg/d) and nitrogen excreted in milk (kg/d) were calculated daily. Nitrogen use efficiency was calculated as the ratio between nitrogen in milk and nitrogen intake, and expressed as a percentage. Individual daily values for NUE ranged from 9.7 to 81.7%, with an average of 36.9% and standard deviation of 10.4%. Milk MIR spectra were recorded twice weekly and were standardized into a common format to avoid bias between apparatus or sampling periods. Regression models predicting NUE using milk MIR spectra were developed on 1,034 observations using partial least squares or support vector machines regression methods. The models were then evaluated through (1) a cross-validation using 10 subsets, (2) a cow validation excluding 25% of the cows to be used as a validation set, and (3) a diet validation excluding each of the diets one by one to be used as validation sets. The best statistical performances were obtained when using the support vector machines method. Inclusion of milk yield and lactation number as predictors, in combination with the spectra, also improved the calibration. In cross-validation, the best model predicted NUE with a coefficient of determination of cross-validation of 0.74 and a relative error of 14%, which is suitable to discriminate between low- and high-NUE cows. When performing the cow validation, the relative error remained at 14%, and during the diet validation the relative error ranged from 12 to 34%. In the diet validation, the models showed a lack of robustness, demonstrating difficulties in predicting NUE for diets and for samples that were not represented in the calibration data set. Hence, a need exists to integrate more data in the models to cover a maximum of variability regarding breeds, diets, lactation stages, management practices, seasons, MIR instruments, and geographic regions. Although the model needs to be validated and improved for use in routine conditions, these preliminary results showed that it was possible to obtain information on NUE through milk MIR spectra. This could potentially allow large-scale predictions to aid both further genetic and genomic studies, and the development of farm management tools.

Fatty acid profile of phospholipids and sphingomyelin in milk and regulation of sphingomyelin synthesis of mammary glands in cows receiving increasing levels of crushed sunflower seeds.

The objective of this study was to investigate the effect of increasing dietary supplementation of crushed sunflower seed (CSS) in the diet of dairy cows on the fatty acid (FA) composition of phospholipids and sphingomyelin in milk, and on mammary transcription of genes that are important for sphingomyelin de novo synthesis. Four groups of 6 cows received diets supplemented with CSS at 0% (control), or 5, 10, or 15% of dry matter for a 5-wk experimental period. Milk samples and mammary biopsies were collected at the end of the experiment. Phospholipid concentration in milk fat decreased linearly with CSS supplementation. Sphingomyelin concentration in milk fat was unaffected by CSS supplementation. Daily yield of phospholipids decreased linearly with CSS supplementation. Daily yield of sphingomyelin was not significantly affected. The CSS supplementation linearly increased the proportion of monounsaturated FA in milk phospholipids. The major isomer incorporated into phospholipids was C18:1 (n-9 cis), which showed a linear increase with CSS supplementation. The C22:0 proportion in sphingomyelin increased linearly with CSS supplementation and constituted between 15.2 to 25.4% of total FA in sphingomyelin. However, CSS supplementation linearly decreased C23:0 sphingomyelin. Mammary transcription of serine palmitoyl transferase, long chain subunit 1 and subunit 2, the rate-limiting enzymes in ceramide synthesis, showed a linear decrease with increasing CSS supplementation. In conclusion, the data showed that dietary supplementation of CSS linearly increased the proportion of unsaturated FA and monounsaturated FA in milk phospholipids with no effect on phospholipid concentration. In addition, CSS supplementation linearly decreased n-3 polyunsaturated fatty acid proportion in sphingomyelin. The results further showed that mammary transcription of important genes for sphingomyelin de novo synthesis is regulated by lipid supplementation.

Between- and within-herd variation in blood and milk biomarkers in Holstein cows in early lactation.

Both blood- and milk-based biomarkers have been analysed for decades in research settings, although often only in one herd, and without focus on the variation in the biomarkers that are specifically related to herd or diet. Biomarkers can be used to detect physiological imbalance and disease risk and may have a role in precision livestock farming (PLF). For use in PLF, it is important to quantify normal variation in specific biomarkers and the source of this variation. The objective of this study was to estimate the between- and within-herd variation in a number of blood metabolites (ß-hydroxybutyrate (BHB), non-esterified fatty acids, glucose and serum IGF-1), milk metabolites (free glucose, glucose-6-phosphate, urea, isocitrate, BHB and uric acid), milk enzymes (lactate dehydrogenase and N-acetyl-ß-D-glucosaminidase (NAGase)) and composite indicators for metabolic imbalances (Physiological Imbalance-index and energy balance), to help facilitate their adoption within PLF. Blood and milk were sampled from 234 Holstein dairy cows from 6 experimental herds, each in a different European country, and offered a total of 10 different diets. Blood was sampled on 2 occasions at approximately 14 days-in-milk (DIM) and 35 DIM. Milk samples were collected twice weekly (in total 2750 samples) from DIM 1 to 50. Multilevel random regression models were used to estimate the variance components and to calculate the intraclass correlations (ICCs). The ICCs for the milk metabolites, when adjusted for parity and DIM at sampling, demonstrated that between 12% (glucose-6-phosphate) and 46% (urea) of the variation in the metabolites' levels could be associated with the herd-diet combination. Intraclass Correlations related to the herd-diet combination were generally higher for blood metabolites, from 17% (cholesterol) to approximately 46% (BHB and urea). The high ICCs for urea suggest that this biomarker can be used for monitoring on herd level. The low variance within cow for NAGase indicates that few samples would be needed to describe the status and potentially a general reference value could be used. The low ICC for most of the biomarkers and larger within cow variation emphasises that multiple samples would be needed - most likely on the individual cows - for making the biomarkers useful for monitoring. The majority of biomarkers were influenced by parity and DIM which indicate that these should be accounted for if the biomarker should be used for monitoring.

Phase 2 study of the Exportin 1 inhibitor selinexor in patients with recurrent gynecological malignancies.

BACKGROUND: Selinexor is an oral inhibitor of the nuclear export protein Exportin 1 (XPO1) with demonstrated antitumor activity in solid and hematological malignancies. We evaluated the efficacy and safety of selinexor in heavily pretreated, recurrent gynecological malignancies. METHODS: In this phase 2 trial, patients received selinexor (35 or 50 mg/m2 twice-weekly [BIW] or 50 mg/m2 once-weekly [QW]) in 4-week cycles. Primary endpoint was disease control rate (DCR) including complete response (CR), partial response (PR) or stable disease (SD) ≥12 weeks. Secondary endpoints were progression-free survival (PFS), overall survival (OS) and safety. RESULTS: 114 patients with ovarian (N = 66), endometrial (N = 23) or cervical (N = 25) cancer were enrolled. Median number of prior regimens for ovarian, endometrial and cervical cancer was 6 (1-11), 2 (1-5), and 3 (1-6) respectively. DCR was 30% (ovarian 30%; endometrial 35%; cervical 24%), which included confirmed PRs in 8%, 9%, and 4% of patients with ovarian, endometrial, and cervical cancer respectively. Median PFS and OS for patients with ovarian, endometrial and cervical cancer were 2.6, 2.8 and 1.4 months, and 7.3, 7.0, and 5.0 months, respectively. Common Grade 3/4 adverse events (AEs) were thrombocytopenia (17%), fatigue (14%), anemia (10%), nausea (9%) and hyponatremia (9%). Patients with ovarian cancer receiving 50 mg/m2 QW had fewer high-grade AEs with similar efficacy as BIW treatment. CONCLUSIONS: Selinexor demonstrated single-agent activity and disease control in patients with heavily pretreated ovarian and endometrial cancers. Side effects were a function of dose level and treatment frequency, similar to previous reports, reversible and mitigated with supportive care.

AC elastocaloric effect as a probe for thermodynamic signatures of continuous phase transitions.

Studying the response of materials to strain can elucidate subtle properties of the electronic structure in strongly correlated materials. Here, we focus on the elastocaloric coefficients, forming a second rank tensor quantity describing the relation between entropy and strain. In contrast to the better-known elastoresistivity, the elastocaloric effect is a thermodynamic quantity. Experimentally, elastocaloric effect measurements are demanding since the thermodynamic conditions during the measurement have to be well controlled. In this work, we present a technique to measure the elastocaloric effect under quasiadiabatic conditions. The technique is based on oscillating strain, which allows for increasing the frequency of the elastocaloric effect above the thermal relaxation rate of the sample. We apply the technique to Co-doped iron pnictide superconductors and show that the thermodynamic signatures of second order phase transitions in the elastocaloric effect closely follow those observed in calorimetry experiments. In contrast to heat capacity, elastocaloric effect measurements allow for the electronic signatures to be measured against a small phononic background even at high temperatures and in addition give information on the symmetry of the involved order parameters. This establishes the technique as a powerful complimentary tool for extracting the entropy landscape as a function of strain proximate to a continuous phase transition.

Potential of milk mid-IR spectra to predict metabolic status of cows through blood components and an innovative clustering approach.

Unbalanced metabolic status in the weeks after calving predisposes dairy cows to metabolic and infectious diseases. Blood glucose, IGF-I, non-esterified fatty acids (NEFA) and ß-hydroxybutyrate (BHB) are used as indicators of the metabolic status of cows. This work aims to (1) evaluate the potential of milk mid-IR spectra to predict these blood components individually and (2) to evaluate the possibility of predicting the metabolic status of cows based on the clustering of these blood components. Blood samples were collected from 241 Holstein cows on six experimental farms, at days 14 and 35 after calving. Blood samples were analyzed by reference analysis and metabolic status was defined by k-means clustering (k=3) based on the four blood components. Milk mid-IR analyses were undertaken on different instruments and the spectra were harmonized into a common standardized format. Quantitative models predicting blood components were developed using partial least squares regression and discriminant models aiming to differentiate the metabolic status were developed with partial least squares discriminant analysis. Cross-validations were performed for both quantitative and discriminant models using four subsets randomly constituted. Blood glucose, IGF-I, NEFA and BHB were predicted with respective R 2 of calibration of 0.55, 0.69, 0.49 and 0.77, and R 2 of cross-validation of 0.44, 0.61, 0.39 and 0.70. Although these models were not able to provide precise quantitative values, they allow for screening of individual milk samples for high or low values. The clustering methodology led to the sharing out of the data set into three groups of cows representing healthy, moderately impacted and imbalanced metabolic status. The discriminant models allow to fairly classify the three groups, with a global percentage of correct classification up to 74%. When discriminating the cows with imbalanced metabolic status from cows with healthy and moderately impacted metabolic status, the models were able to distinguish imbalanced group with a global percentage of correct classification up to 92%. The performances were satisfactory considering the variables are not present in milk, and consequently predicted indirectly. This work showed the potential of milk mid-IR analysis to provide new metabolic status indicators based on individual blood components or a combination of these variables into a global status. Models have been developed within a standardized spectral format, and although robustness should preferably be improved with additional data integrating different geographic regions, diets and breeds, they constitute rapid, cost-effective and large-scale tools for management and breeding of dairy cows.

Hydrochlorothiazide and acute urinary acidification: The "voltage hypothesis" of ENaC-dependent H+ secretion refuted.

AIM: The "voltage hypothesis" of H+ secretion states that urinary acidification following increased Na+ delivery to the collecting duct (CD) is ENaC dependent leading to transepithelial voltage-dependent increase in H+ secretion. We recently showed that furosemide acidifies the urine independently of ENaC activity. If the voltage hypothesis holds, hydrochlorothiazide (HCT) must acidify the urine. We here tested the acute effect of HCT on urine pH under normal and high ENaC expression. METHODS: Mice subjected to a control or a low-Na+ diet were anesthetized and infused (0.5 mL h-1 ) with saline. Catheterization of the urinary bladder allowed real-time measurement of diuresis and urine pH. Mice received either HCT (1 mg mL-1 ) or vehicle. Urinary Na+ and K+ excretions were determined by flame photometry. ENaC expression levels were measured by semi-quantitative Western blotting. RESULTS: (1) HCT increased diuresis and natriuresis in both diet groups. (2) K+ excretion rates increased after HCT administration from 18.6 ± 1.3 to 31.7 ± 2.5 µmol h-1 in the control diet group and from 23.0 ± 1.3 to 48.7 ± 3.0 µmol h-1 in the low-Na+ diet group. (3) Mice fed a low-Na+ diet showed a marked upregulation of ENaC. (4) Importantly, no acute changes in urine pH were observed after the administration of HCT in either group. CONCLUSION: Acute administration of HCT has no effect on urine pH. Similarly, substantial functional and molecular upregulation of ENaC did not cause HCT to acutely change urine pH. Thus, an increased Na+ load to the CD does not alter urine pH. This supports our previous finding and likely falsifies the voltage hypothesis of H+ secretion.