Predicting subacute ruminal acidosis from milk mid-infrared estimated fatty acids and machine learning on Canadian commercial dairy herds.

Our objective was to validate the possibility of detecting SARA from milk Fourier transform mid-infrared spectroscopy estimated fatty acids (FA) and machine learning. Subacute ruminal acidosis is a common condition in modern commercial dairy herds for which the diagnostic remains challenging due to its symptoms often being subtle, nonexclusive, and not immediately apparent. This observational study aimed at evaluating the possibility of predicting SARA by developing machine learning models to be applied to farm data and to provide an estimated portrait of SARA prevalence in commercial dairy herds. A first data set composed of 488 milk samples of 67 cows (initial DIM = 8.5 ± 6.18; mean ± SD) from 7 commercial dairy farms and their corresponding SARA classification (SARA+ if rumen pH <6.0 for 300 min, else SARA-) was used for the development of machine learning models. Three sets of predictive variables: i) milk major components (MMC), ii) milk FA (MFA), and iii) MMC combined with MFA (MMCFA) were submitted to 3 different algorithms, namely Elastic net (EN), Extreme gradient boosting (XGB), and Partial least squares (PLS), and evaluated using 3 different scenarios of cross-validation. Accuracy, sensitivity, and specificity of the resulting 27 models were analyzed using a linear mixed model. Model performance was not significantly affected by the choice of algorithm. Model performance was improved by including fatty acids estimations (MFA and MMCFA as opposed to MMC alone). Based on these results, one model was selected (algorithm: EN; predictive variables: MMCFA; 60.4, 65.4, and 55.3% of accuracy, sensitivity, and specificity, respectively) and applied to a large data set comprising the first test-day record (milk major components and FA within the first 70 DIM of 211,972 Holstein cows (219,503 samples) collected from 3001 commercial dairy herds. Based on this analysis, the within-herd SARA prevalence of commercial farms was estimated at 6.6 ± 5.29% ranging from 0 to 38.3%. A subsequent linear mixed model was built to investigate the herd-level factors associated to higher within-herd SARA prevalence. Milking system, proportion of primiparous cows, herd size and seasons were all herd-level factors affecting SARA prevalence. Furthermore, milk production was positively, and milk fat yield negatively associated with SARA prevalence. Due to their moderate levels of accuracy, the SARA prediction models developed in our study, using data from continuous pH measurements on commercial farms, are not suitable for diagnostic purpose. However, these models can provide valuable information at the herd level.

Relationship between farm management strategies, reticuloruminal pH variations, and risks of subacute ruminal acidosis.

Low reticuloruminal pH (rpH), often observed in subacute ruminal acidosis (SARA), may negatively affect rumen health and animal performance. To investigate the variability of rpH and the prevalence of SARA on commercial farms, we conducted an observational study on 110 early-lactation Holstein cows of different parities from 12 farms selected to cover a broad range of farm management strategies. The rpH of each cow was continuously monitored for 50 d using wireless boluses. To study the effects of animal and farm management characteristics on rpH, we used a multivariable mixed model analysis with the animal and farm as random effects. Automatic milking system and presence of corn silage in the ration were associated with a decrease in rpH of 0.37 and 0.20 pH units, respectively, whereas monensin supplementation was associated with an increase of 0.27 pH units. The rpH increased by 0.15 pH units during the first 60 d in milk. We defined a SARA-positive day as rpH below 5.8 (SARA5.8) or 6.0 (SARA6.0) for at least 300 min for 1 d. Using those definitions, during our study, a total of 38 (35%) and 65 (59%) cows experienced at least one episode of SARA5.8 and SARA6.0, respectively. The proportion of cows with at least one SARA-positive day varied among farms from 0 to 100%. Automatic milking system was associated with an increased risk of SARA5.8 (odds ratio: 10) and SARA6.0 (odds ratio: 11). The use of corn silage was associated with an increased risk of SARA5.8 (odds ratio: 21), whereas the use of monensin was associated with a decreased risk of SARA5.8 (odds ratio: 0.02). Our study shows that rpH is quite variable among farms, but also among animals on the same farm. We also show that multiple animal and farm characteristics are associated with rpH variability and the risk of SARA under commercial conditions.

[Alcohol dependence in primary care : a clinical approach by the GP]. / Prise en charge du mésusage de l'alcool avec dépendance par le médecin généraliste.

Clinical care to patients with alcohol dependence by GP's is described in this article. First, we have to destigmatize these patients and their illness. Diagnosis approach is specified. Therapeutic approach is first a motivational approach; subsequently it's like pedagogy : it's coping. Care is both physical and psychological. Empathy all along therapeutic relationship is a priority and how establishing a therapeutic alliance is described. A psychiatrist, a psychologist, a care network, self-help associations have also to be called on when needed. Physicians education creates new opportunities since 2016-2017 : in particular SSMG (Scientific Society of Primary Care) and three Belgian universities (UCL, ULB and ULiège) introduced a special study program called «?certificat interuniversitaire d'alcoologie?¼. Let's hope this new clinical rewarding approach for GP's contribute to reduce the treatment gap as far as clinical care of patients with alcohol dependence is concerned.

La prise en charge clinique du mésusage d'alcool avec dépendance par le médecin généraliste est décrite dans cet article. Il s'agit, d'abord, de déstigmatiser ces patients et leur pathologie. La démarche diagnostique est précisée. L'approche thérapeutique est, d'abord, motivationnelle; elle prendra, ensuite, des allures pédagogiques : il s'agit de coping. Les soins sont physiques et psychologiques. L'empathie, tout au long de la relation thérapeutique, est fondamentale et les techniques pour créer l'alliance thérapeutique sont décrites. Savoir référer au psychologue, faire appel au réseau, collaborer avec le psychiatre, conseiller l'entraide sont des initiatives nécessaires. La formation des médecins généralistes connaît de nouvelles opportunités : notamment, grâce à un certificat interuniversitaire d'alcoologie mis sur pied à la rentrée académique 2016-2017 à l'initiative de la Société Scientifique de Médecine Générale (SSMG) et de trois universités francophones (UCL, ULB et ULiège). On peut espérer que ces nouvelles pratiques cliniques, valorisantes pour le médecin généraliste, contribueront à réduire le «?treatment gap?¼ dans la prise en charge du mésusage d'alcool avec dépendance, un véritable défi de santé publique.

Detecting gene signature activation in breast cancer in an absolute, single-patient manner.

BACKGROUND: The ability to reliably identify the state (activated, repressed, or latent) of any molecular process in the tumor of a patient from an individual whole-genome gene expression profile obtained from microarray or RNA sequencing (RNA-seq) promises important clinical utility. Unfortunately, all previous bioinformatics tools are only applicable in large and diverse panels of patients, or are limited to a single specific pathway/process (e.g. proliferation). METHODS: Using a panel of 4510 whole-genome gene expression profiles from 10 different studies we built and selected models predicting the activation status of a compendium of 1733 different biological processes. Using a second independent validation dataset of 742 patients we validated the final list of 1773 models to be included in a de novo tool entitled absolute inference of patient signatures (AIPS). We also evaluated the prognostic significance of the 1773 individual models to predict outcome in all and in specific breast cancer subtypes. RESULTS: We described the development of the de novo tool entitled AIPS that can identify the activation status of a panel of 1733 different biological processes from an individual breast cancer microarray or RNA-seq profile without recourse to a broad cohort of patients. We demonstrated that AIPS is stable compared to previous tools, as the inferred pathway state is not affected by the composition of a dataset. We also showed that pathway states inferred by AIPS are in agreement with previous tools but use far fewer genes. We determined that several AIPS-defined pathways are prognostic across and within molecularly and clinically define subtypes (two-sided log-rank test false discovery rate (FDR) <5%). Interestingly, 74.5% (1291/1733) of the models are able to distinguish patients with luminal A cancer from those with luminal B cancer (Fisher's exact test FDR <5%). CONCLUSION: AIPS represents the first tool that would allow an individual breast cancer patient to obtain a thorough knowledge of the molecular processes active in their tumor from only one individual gene expression (N-of-1) profile.

Idiopathic dilatation of the pulmonary artery: report of four cases.

Idiopathic dilatation of the pulmonary artery (IDPA) is a rare congenital disease which is usually detected fortuitously on chest x-ray, thus radiologists must be aware of this clinical entity. This report describes four cases to which Magnetic Resonance Imaging (MRI) played a major role in diagnosing IDPA and in detecting the concomitant findings observed in this disease. MRI is a non-invasive procedure with many advantages for the accurate and reproducible measurement of artery structures, which makes it the preferred option for combined use with echocardiography in the diagnosis and follow-up of patients with IDPA.

Angiosarcomas of the interatrial septum mimicking atrial myxomas.

Angiosarcoma of the heart is a rare tumor. This tumor is most frequently located in the right atrium and pericardium. Localization of a tumor in the interatrial septum usually suggests atrial myxoma. We report two cases of angiosarcoma originating from the interatrial septum, one extending into the right atrium and the other into the left atrium, mimicking atrial myxomas. Transesophageal echocardiography allowed the diagnosis and comprehensive assessment of compromised structures.

Mediastinal and pericardial complications after heart transplantation. Not-so-unusual postoperative problems?

Of a total of 133 patients who underwent heart transplantation, 16(12%) had pericardial and mediastinal complications. Non-infectious pericardial complications, pericardial effusion and constriction were noted in ten patients, and infectious pericarditis or mediastinitis in six. Cardiac echocardiography, catheterization and magnetic resonance imaging were useful in assessing these problems. All patients underwent surgical treatment, pericardial drainage, pericardectomy or muscle flap closure. Twelve (75%) of these 16 patients are long-term survivors. In conclusion, pericardial and mediastinal complications are common after heart transplantation, and aggressive surgical treatment is most often effective in their control.

Asymptomatic heterotopic thyroid tumour in the right ventricular infundibulum.

An asymptomatic thyroid cardiac tumour was discovered in the right ventricular infundibulum of a 63-year-old female investigated for angina. The results of the investigation are presented: coronary angiography, echocardiography, magnetic resonance imaging, resting radioactive 201-thallium scintigraphy, dipyridamole-thallium scintigraphy, nuclear isotopic ventriculography. The tumour was successfully removed at surgery for coronary bypass. Anatomopathological description is also included.

Pseudoaneurysm after Bentall repair: magnetic resonance imaging assessment.

The prevalence and natural history of pseudoaneurysms (PA) following Bentall procedure has not been established. To determine the follow-up of PA in patients, the authors report their experience with magnetic resonance imaging (MRI) since 1988. Spin-echo technique suspected PA in 19 of the 27 patients who underwent aortic valve and ascending aortic replacement between 1980 and 1991. Mean PA diameter was less than 4 cm in 13 patients (group 1) and at least 4 cm in six patients (group 2). Two patients in group 1 were lost at follow-up while two others in this group died after first spin-echo examination (one death was related to PA formation). Repeated MRIs were thus possible in nine patients in group 1 and in all patients in group 2, averaging 2.2 +/- 1.1 examinations per patient for group 1 and 1.8 +/- 1.1 for group 2. PA assessed in six group 1 patients and one group 2 patient suggested thrombosed PA or postoperative hematoma. PA remained stable in two group 1 patients and one group 2 patient. One patient from group 1, in whom PA increased at follow-up, died suddenly. Four patients in group 2 required correction of PA, which had increased in diameter. Recently, addition of cine MRI has allowed visualization of turbulent flow within PA, thus increasing MRI specificity for PA diagnosis. In conclusion, MRI constitutes a reliable noninvasive imaging technique for diagnosis and follow-up of PA after Bentall repair.

[Magnetic resonance imaging in the diagnosis and follow-up of false aneurysms after Bentall's operation]. / La résonance magnétique pour le diagnostic et le suivi des pseudoanévrismes après intervention de type Bentall.

The prevalence and natural history of pseudo-aneurysm (PA) following Bentall procedure has not been established. To determine the follow-up of such patients, we report our experience with magnetic resonance imaging (MRI) used since 1988. At first, spin-echo exam, PA was suspected in 19 patients among 27 patients who underwent aortic valve and ascending aortic replacement between 1980 and 1991. Mean PA diameter was < 4 cm in 13 patients (group 1) and > or = 4 cm in six patients (group 2). Two patients of group 1 were lost at follow-up while two others died after the first spin-echo exam, one death being related to PA formation. Repeated MRIs were done in nine patients of group 1 and all patients of group 2 averaging respectively 2.2 +/- 1.1 exams per patient for group 1 and 1.8 +/- 1.1 for group 2. PA regressed in six patients of group 1 and one patient of group 2 thus suggesting thrombosed PA or postoperative haematoma. PA remained stable in two patients of group 1 and one patient of group 2. One patient of group 1 in whom PA increased at follow-up died suddenly. Four patients of group 2 required surgical correction of their PA. One of these patients died of massive hemoptysis 2 months following reintervention. Recently, addition of cine MRI allows visualization of turbulent flow within the PA thus increasing MRI specificity for PA diagnosis.(ABSTRACT TRUNCATED AT 250 WORDS)

Assessment of left ventricular function using digital angiography.

We have demonstrated that selective digital left ventricular angiography using small amounts of contrast material minimized both symptoms and hemodynamic alterations and provided good images for assessment of regional ventricular function. However, comparisons of ejection fraction (EF), end-systolic volume (ESV), and end-diastolic volume (EDV) from digital angiography, at 10 frames per second, with measurements derived from conventional angiography, showed only a fair correlation between the two methods. Using a new generation of digital equipment and an acquisition time of 30 frames per second, we studied the correlation between digital and conventional angiography in 29 patients with coronary artery disease for a wide spectrum of left ventricular functions. Ventricular volumes and EF were calculated by computer using the area-length method. The correlation coefficient (r) between both the methods was 0.93 for EF, 0.95 for ESV and 0.89 for EDV. Thus digital left ventricular angiography provides an accurate evaluation of left ventricular function and can with advantage replace conventional angiography for this purpose.

Usefulness of digital subtraction left ventriculography in patients with ischemic heart disease: comparison with cineangiography.

Digital subtraction and computer enhancement of left ventriculography allow the injection of small amounts of contrast medium into the left ventricle. Image quality measurements of cardiac volumes, and ejection fraction and evaluation of regional wall motion were compared following digital subtraction and cine ventriculography in 30 patients undergoing coronary arteriography for suspected or proven ischemic heart disease. At concentrations of 13% to 19% (iodine contents: 2.0 to 5.0 g) meglumine sodium diatrizoate used for digital subtraction ventriculography, no alterations of ventricular pressures were noted; premature ventricular contraction and cineventriculography in 30 patients undergoing coronary arteriography for suspected wall motion by two independent observers showed complete agreement between digital and cineventriculography in 141 of 150 segments (94%), including 114 normal segments; digital ventriculography led to underestimation of four segments and to overestimation of five. Left ventricular ejection fraction and volumes calculated using both techniques correlated relatively well (ejection fraction: r = 0.86; end systolic volume: r = 0.88; end diastolic volume: r = 0.665). Thus, intraventricular injection of low concentrations of contrast medium provides good digital angiographic images and may eventually replace cine ventriculography for invasive assessment of left ventricular performance. However, ECG gating and shorter exposure times will be required for accurate measurement of ventricular volumes and ejection fractions.

Comparison of digital and radionuclide left ventriculography in patients at risk from conventional left ventriculography.

In this study, two alternative methods of assessing left ventricular (LV) sequential wall motion and ejection fraction (EF) were used in 28 consecutive patients in whom an unstable clinical condition (unstable angina pectoris or severe LV dysfunction) precluded the use of high volume contrast cineventriculography. A new approach, direct small volume contrast digital ventriculography, was compared to radionuclide blood pool ventriculography considered as a "standard" and reliable technique. The qualitative analysis of regional LV contraction by three independent observers showed a complete agreement in 64% of segments studied in the left anterior oblique (LAO) projection and in 69% in the right anterior oblique (RAO) projection; a one-degree disagreement was observed in 13% and 19% respectively, and a discrepancy of two degrees or more in 23% and 12% respectively. Left ventricular ejection fraction calculated from both techniques correlated relatively well (r = 0.82). The radionuclide examination still remains the fastest, easiest and most objective way to appraise global LV function in high risk patients. However, optimal analysis of segmental wall motion requires invasive digital contrast left ventriculography. In future, a more general use of non-ionic contrast media including their intravenous injection and the advent of portable digital devices should permit their widespread use as a safe, rapid and reliable procedure even in the intensive care unit.

Clinical experience with ioxaglate (Hexabrix) in selective coronary arteriography.

This prospective nonrandomized study was performed to evaluate the safety and efficacy of, as well as patient tolerance for, a new low osmolality contrast medium, ioxaglate (Hexabrix), in 90 adult patients of both sexes who were referred to our cardiac catheterization laboratory for angiocardiography including selective coronary arteriography. Ioxaglate did not cause any major adverse effects; side effects were rare and mild. Hemodynamic changes were minimal, even in patients with severe coronary artery disease, and no arrhythmias were seen. The radiographic quality of angiograms was scored as good to excellent for each examination, and was equal to that of films performed using a conventional contrast medium. Ioxaglate may be the contrast medium of choice for angiocardiography, especially in patients at high risk, i.e., those with severe coronary artery disease or severe left ventricular dysfunction.

Value of a cinefluoroscopic assessment of the Lillehei-Kaster prosthetic heart valves.

In order to assess the functioning of the pivoting disc of the Lillehei-Kaster prosthetic valve, a cinefluoroscopic technique using multiple angulations was developed. The disc was detected in 240 (99%) of the 242 valves studied (126 aortic, 107 mitral, and nine tricuspid valves). The maximal-opening angle of the disc was measured in 75% of the aortic but only 20% of the mitral valve prostheses in the 182 valve studies in which this was attempted. Prosthetic dysfunctions were suspected clinically in three aortic and three tricuspid valves and confirmed with the cinefluoroscopic technique. This cinefluoroscopic approach constitutes a rapid, noninvasive, and sensitive evaluation of the function of the Lillehei-Kaster prosthetic valve in the aortic position.

Myocardial color scan with 43K in ischemic heart disease.

The value of myocardial scanning with 43K was assessed in 64 consecutive patients undergoing coronary arteriography, and in five young volunteers. Myocardial scans at rest detected only 16 of the 35 transmural infarcts documented on electrocardiograms, 11 of 11 anterior infarcts and five of 24 in other sites. Myocardial scans were obtained immediately after a graded exercise test in the five normal volunteers, in nine patients with normal coronary arteriograms and in 25 patients with atherosclerotic narrowing greater than 75% involving the left anterior descending artery, with or without disease of other coronary vessels. All patients with normal coronary arteriograms had normal myocardial scans. A regional perfusion deficit was observed after exercise in all six patients with single vessel disease, but in only 11 of the 19 patients with disease involving two or three vessels. Although the technique was specific, it lacked sensitivity, due mostly to poor resolution and the location of the disease.