Diagnostic milk biomarkers for predicting the metabolic health status of dairy cattle during early lactation.

Data on metabolic profiles of blood sampled at d 3, 6, 9, and 21 in lactation from 117 lactations (99 cows) were used for unsupervised k-means clustering. Blood metabolic parameters included ß-hydroxybutyrate (BHB), nonesterified fatty acids, glucose, insulin-like growth factor-1 (IGF-1) and insulin. Clustering relied on the average and range of the 5 blood parameters of all 4 sampling days. The clusters were labeled as imbalanced (n = 42) and balanced (n = 72) metabolic status based on the values of the blood parameters. Various random forest models were built to predict the metabolic cluster of cows during early lactation from the milk composition. All the models were evaluated using a leave-group-out cross-validation, meaning data from a single cow were always present in either train or test data to avoid any data leakage. Features were either milk fatty acids (MFA) determined by gas chromatography (MFA [GC]) or features that could be determined during a routine dairy herd improvement (DHI) analysis, such as concentration of fat, protein, lactose, fat/protein ratio, urea, and somatic cell count (determined and reported routinely in DHI registrations), either or not in combination with MFA and BHB determined by mid-infrared (MIR), denoted as MFA [MIR] and BHB [MIR], respectively, which are routinely analyzed but not routinely reported in DHI registrations yet. Models solely based on fat, protein, lactose, fat/protein ratio, urea and somatic cell count (i.e., DHI model) were characterized by the lowest predictive performance [area under the receiver operating characteristic curve (AUCROC) = 0.69]. The combination of the features of the DHI model with BHB [MIR] and MFA [MIR] powerfully increased the predictive performance (AUCROC = 0.81). The model based on the detailed MFA profile determined by GC analysis did not outperform (AUCROC = 0.81) the model using the DHI-features in combination with BHB [MIR] and MFA [MIR]. Predictions solely based on samples at d 3 were characterized by lower performance (AUCROC DHI + BHB [MIR] + MFA [MIR] model at d 3: 0.75; AUCROC MFA [GC] model at d 3: 0.73). High predictive performance was found using samples from d 9 and 21. To conclude, overall, the DHI + BHB [MIR] + MFA [MIR] model allowed to predict metabolic status during early lactation. Accordingly, these parameters show potential for routine prediction of metabolic status.

[The COVID-19 breaker : PCR to the rescue !] / La déferlante COVID-19 : la PCR à la rescousse ! Chronique d'une gestion de crise au Laboratoire de Microbiologie clinique du CHU de Liège.

Chronicle of a crisis management at the Clinical Microbiology Laboratory of CHU Liège The SARS-CoV-2 outbreak in December 2019 in China and its expansion across the world and Europe have requested the participation of clinical laboratories as major players in the diagnosis of COVID-19, to perform PCR tests mainly on nasopharyngeal swabs. In Belgium, the first confirmed COVID-19 patient was diagnosed in early February, the first of many, especially travelers returning from winter sports. In order to meet the ever-increasing demands for testing, the Clinical Microbiology Laboratory of the CHU of Liege had to adapt to this situation: firstly, by developing manual PCR tests and then automated solutions, permitting to increase the number of analyzes by ensuring a short turnaround time of results. Then, a system for the communication of results on a large scale has been set up, and finally solutions to deal with the lack of sampling devices have been found. This first wave of the pandemic has also highlighted an unprecedented solidarity within the institution. In this article, we recount the chronology of the management of this unprecedented health crisis within the Clinical Microbiology Laboratory of the CHU of Liege.

L'émergence du virus SARS-CoV-2 en décembre 2019 en Chine et son expansion à travers le monde et l'Europe ont sollicité la participation des laboratoires de Biologie clinique en tant qu'acteurs majeurs dans le diagnostic de la COVID-19, via la réalisation de tests PCR principalement sur des prélèvements nasopharyngés. En Belgique, le premier patient confirmé COVID-19 a été diagnostiqué début février, avant d'être suivi par de nombreux cas d'infections, initialement chez des vacanciers revenant des sports d'hiver. Afin de répondre à l'augmentation du nombre de tests, le laboratoire de Microbiologie clinique du CHU de Liège a dû s'adapter en développant des tests PCR, d'abord manuels puis automatisés. Ceux-ci ont permis d'augmenter le nombre d'analyses, tout en garantissant un temps de rendu des résultats court, en mettant en place un système de communication des résultats à grande échelle et en trouvant des solutions pour faire face à la pénurie des dispositifs de prélèvement. Cette première vague de la pandémie a aussi révélé une solidarité sans précédent au sein de l'institution. Dans cet article, nous retraçons la chronologie de la gestion de cette crise sanitaire inédite au sein du laboratoire de Microbiologie clinique du CHU de Liège.

[Role of physical and rehabilitation medicine in the aftermath of SARS-CoV-2 disease]. / Rôle de la médecine physique et réadaptation fonctionnelle dans les suites d'une atteinte au SARS-CoV-2.

2020 will be remembered as the year of SARS-CoV-2 pandemic which confined most of the world's population at home. Rehabilitation units will have to face specific challenges to protect the vulnerable in-patients. Moreover, they must prepare for post-COVID-19 patients who might suffer from illness consequences or present a post intensive care syndrome secondary to the increased ICU length of stay. The purpose of this paper is to highlight the deficiencies of post-COVID-19 patients and suggest a decision algorithm to best match their needs.

L'année 2020 restera marquée par la pandémie de SARS-CoV-2, originaire de Chine, qui a confiné une grande partie de la population mondiale. Les services de médecine physique et rééducation fonctionnelle ont dû adopter des mesures spécifiques afin de limiter la contagion de leurs patients, appartenant à la population à risque. Ils se préparent également à l'accueil et à la prise en charge des patients post-COVID-19 présentant des séquelles secondaires à l'infection ou à l'hospitalisation prolongée en réanimation, responsable d'un syndrome post-soins intensifs. L'objectif de cet article est de dégager les différentes pathologies auxquelles les médecins rééducateurs seront confrontés et de proposer un algorithme décisionnel pour orienter la prise en charge rééducative.

Single-center experience of patients with interstitial lung diseases during the early days of the COVID-19 pandemic.

INTRODUCTION: Patients with interstitial lung diseases (ILD) can be suspected to be at risk of experiencing a rapid flare-up due to COVID-19. However, no specific data are currently available for these patients. METHODS: We retrospectively analyzed a cohort of 401 patients with ILD and determined the proportion of patients hospitalized for proven severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and specific symptoms of COVID-19. RESULTS: We found that 1% of patients (n = 4) were hospitalized (1 in ICU) for COVID-19. In total, 310 of the 401 patients answered the phone call. Only 33 patients (0.08%) experienced specific symptoms of SARS-CoV-2 infection. CONCLUSION: Our study did not demonstrate any increased occurrence of severe COVID-19 in ILD patients compared to the global population. Based on our findings, we could not make any conclusion on the incidence rate of SARS-CoV-2 infection in patients with ILDs, or on the overall outcome of immunocompromised patients affected by COVID-19.

A snapshot of European neurosurgery December 2019 vs. March 2020: just before and during the Covid-19 pandemic.

BACKGROUND: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2 or Covid-19), which began as an epidemic in China and spread globally as a pandemic, has necessitated resource management to meet emergency needs of Covid-19 patients and other emergent cases. We have conducted a survey to analyze caseload and measures to adapt indications for a perception of crisis. METHODS: We constructed a questionnaire to survey a snapshot of neurosurgical activity, resources, and indications during 1 week with usual activity in December 2019 and 1 week during SARS-CoV-2 pandemic in March 2020. The questionnaire was sent to 34 neurosurgical departments in Europe; 25 departments returned responses within 5 days. RESULTS: We found unexpectedly large differences in resources and indications already before the pandemic. Differences were also large in how much practice and resources changed during the pandemic. Neurosurgical beds and neuro-intensive care beds were significantly decreased from December 2019 to March 2020. The utilization of resources decreased via less demand for care of brain injuries and subarachnoid hemorrhage, postponing surgery and changed surgical indications as a method of rationing resources. Twenty departments (80%) reduced activity extensively, and the same proportion stated that they were no longer able to provide care according to legitimate medical needs. CONCLUSION: Neurosurgical centers responded swiftly and effectively to a sudden decrease of neurosurgical capacity due to relocation of resources to pandemic care. The pandemic led to rationing of neurosurgical care in 80% of responding centers. We saw a relation between resources before the pandemic and ability to uphold neurosurgical services. The observation of extensive differences of available beds provided an opportunity to show how resources that had been restricted already under normal conditions translated to rationing of care that may not be acceptable to the public of seemingly affluent European countries.

Chemoprevention of LA7-Induced Mammary Tumor Growth by SM6Met, a Well-Characterized Cyclopia Extract.

Breast cancer (BC) is the leading cause of cancer-related deaths in women. Chemoprevention of BC by using plant extracts is gaining attention. SM6Met, a well-characterized extract of Cyclopia subternata with reported selective estrogen receptor subtype activity, has shown tumor suppressive effects in a chemically induced BC model in rats, which is known to be estrogen responsive. However, there is no information on the estrogen sensitivity of the relatively new orthotopic model of LA7 cell-induced mammary tumors. In the present study, the potential chemopreventative and side-effect profile of SM6Met on LA7 cell-induced tumor growth was evaluated, as was the effects of 17ß-estradiol and standard-of-care (SOC) endocrine therapies, such as tamoxifen (TAM), letrozole (LET), and fulvestrant (FUL). Tumor growth was observed in the tumor-vehicle control group until day 10 post tumor induction, which declined afterward on days 12-14. SM6Met suppressed tumor growth to the same extent as TAM, while LET, but not FUL, also showed substantial anti-tumor effects. Short-term 17ß-estradiol treatment reduced tumor volume on days prior to day 10, whereas tumor promoting effects were observed during long-term treatment, which was especially evident at later time points. Marked elevation in serum markers of liver injury, which was further supported by histological evaluation, was observed in the vehicle-treated tumor control, TAM, LET, and long-term 17ß-estradiol treatment groups. Alterations in the lipid profiles were also observed in the 17ß-estradiol treatment groups. In contrast, SM6Met did not augment the increase in serum levels of liver injury biomarkers caused by tumor induction and no effect was observed on lipid profiles. In summary, the results from the current study demonstrate the chemopreventative effect of SM6Met on mammary tumor growth, which was comparable to that of TAM, without eliciting the negative side-effects observed with this SOC endocrine therapy. Furthermore, the results of this study also showed some responsiveness of LA7-induced tumors to estrogen and SOC endocrine therapies. Thus, this model may be useful in evaluating potential endocrine therapies for hormone responsive BC.

The importance of adequate fixation for immunofluorescent staining of bovine embryos.

Immunofluorescent staining is often used to investigate the expression of specific proteins in pre-implantation embryos. The success of this method is determined by the specificity of the antibodies, but also by the protocol used for fixation and permeabilization of the samples. In this study, different fixatives are compared in combination with immunofluorescent staining of caudal-type homeobox 2 (CDX2), fibronectin 1 (FN1) and integrins (ITGs) on bovine blastocysts. For both CDX2 and the ITGs, the outcome of the staining was largely dependent on the fixation methods. Paraformaldehyde fixation was best for the intracellular CDX2 protein, whereas acetone fixation gave the best results for the transmembrane ITGs. No difference was observed for the FN1 staining between samples fixed with paraformaldehyde or acetone. These examples demonstrate that the choice of fixation and permeabilization agents is very important for the outcome of the experiment, and this choice is dictated by the (extra)cellular location of the protein under investigation. Inappropriate fixation and/or permeabilization methods can lead to erroneous conclusions regarding the site and amount of protein expression.

Involvement of T-cell receptor-beta alterations in the development of otosclerosis linked to OTSC2.

Otosclerosis is a common form of hearing loss, characterized by disordered bone remodeling in the otic capsule. Within the otosclerotic foci, several immunocompetent cells and immune-modulating factors can be found. Different etiological theories involving the immune system have been suggested. However, a genetic component is clearly present. In large otosclerosis families, seven autosomal-dominant loci have been found, but none of the disease-causing genes has been identified. This study focused on the exploration of the second otosclerosis locus on chromosome 7q34-36 (OTSC2), holding the T-cell receptor beta locus (TRB locus). A significantly lower T-cell receptor-beta (TCR-beta) mRNA expression and percentage of blood circulating TCR-alphabeta(+) T cells was detected in OTSC2 patients compared with controls and patients with the complex form of the disease. Further analysis illustrated more significant disturbances in specific T-cell subsets, including an increased CD28(null) cell population, suggesting a disturbed T-cell development and ageing in OTSC2 patients. These disturbances could be associated with otosclerotic bone remodeling, given the known effects of immunocompetent cells on bone physiology. These data implicate the TRB locus as the causative gene in the OTSC2 region and represent an important finding in the elucidation of the disease pathology.

Short-term exposure to hydrogen peroxide during oocyte maturation improves bovine embryo development.

Recent studies have shown that short-term exposure of oocytes to a stressor such as hydrostatic pressure or osmotic stress might induce stress tolerance in embryos. The aim of the present study was to investigate the consequences of short-term hydrogen peroxide (H(2)O(2)) exposure to bovine in vitro matured cumulus-oocyte complexes (COCs) on subsequent preimplantation embryo development and apoptosis. In the first experiment, mature COCs were incubated in H(2)O(2) at concentrations ranging between 0.01 and 100 micromol/l, and subsequently fertilized and cultured. Oocyte incubation with 50-100 micromol/l of H(2)O(2) resulted in a significantly higher blastocyst yield (47.3%) in comparison with control medium (31.8%), while apoptotic cell ratio was inversely related with H(2)O(2) concentration. In the second experiment, we showed that the stress tolerance after H(2)O(2) exposure was not mediated by increased glutathione content in treated oocytes nor by enhanced fertilization or penetration. Further research should concentrate on the potential role of players that have been associated with stress tolerance in somatic cell lines.

Detection of rare nonsynonymous variants in TGFB1 in otosclerosis patients.

Otosclerosis is one of the most common forms of hearing loss in the European population. We have identified a SNP in the TGFB1 (transforming growth factor beta 1) gene that is associated with susceptibility to otosclerosis. The protective allele of this variant, with isoleucine at position 263 of the protein, is more biologically active than the risk allele, which has a threonine in this position. Because recent studies have shown that not only common, but also rare variants can be involved in complex diseases, we performed DNA sequence analysis of the exons and intron-exon boundaries of TGFB1 in 755 otosclerosis patients and 877 control samples. We found 3 different nonsynonymous variants (E29, A29 and I241) in four otosclerosis patients, but no such changes were found in controls. In silico analysis shows that these variations could influence TGF-beta1 function and activity. Taking into account that most rare missense alleles are thought to have a biological effect, the data suggest that multiple rare amino acid changing variants in TGF-beta1 may contribute to susceptibility to otosclerosis.

In vitro fertilizing capacity of frozen-thawed bull spermatozoa selected by single-layer (glycidoxypropyltrimethoxysilane) silane-coated silica colloidal centrifugation.

Barriers to the use of density gradient centrifugation for preparing animal spermatozoa for artificial insemination (AI) include the scarcity of animal-specific formulations and the daunting prospect of processing large volumes of ejaculate in small aliquots (1.5 ml extended semen). Recently, new colloid formulations have been tested in vitro in a modified procedure, centrifugation on a single layer of colloid. The present study investigated the fertilizing ability during in vitro fertilization (IVF) of frozen-thawed bovine spermatozoa following centrifugation through a single layer of glycerolpropylsilane (GS)-coated silica colloid with a species-specific formulation (patent applied for; treatment, T). Controls (C) included centrifugation through gradients of either the same colloid (C1) or Percoll (C2). Sperm recovery surpassed 50% for both C1-C2 and T (n.s.). Mean values of various parameters of computerized analysis of sperm motility did not differ between T and C1 (n.s.), and only the proportions of path straightness and linearity were lower in T vs C2 (p < 0.05). In T, the mean (+/-SD) percentages of fertilization rate, blastocyst development rate and the total number of blastomeres were 58.1 +/- 23.3%, 24.5 +/- 14.3% and 94.6 +/- 23.4%, respectively. The proportions did not differ significantly from controls (C1/C2). Therefore, centrifugation through a single layer of colloid offers an alternative method to density gradient centrifugation for selection of viable, potentially fertile frozen-thawed bull spermatozoa. This single-layer technique is gentle, versatile and convenient because it facilitates scaling-up the process of sperm preparation to allow larger numbers of spermatozoa (for instance, whole ejaculates) to be processed for AI.

Single-nucleotide polymorphisms in the COL1A1 regulatory regions are associated with otosclerosis.

Otosclerosis (MIM 166800) has a prevalence of 0.2-1% among white adults, making it the single most common cause of hearing impairment in this ethnic group. Although measles virus, hormones, human leukocyte antigen alleles and genetic factors have been implicated in the development of otosclerosis, its etiology remains unknown. In a focused effort to identify genetic factors in otosclerosis, we have mapped four disease loci (MIM 166800/605727/608244/608787); however, cloning the disease-causing genes in these intervals has not been successful. Here, we used a case-control study design to investigate the association between collagen type I genes and otosclerosis. We identified susceptibility and protective haplotypes in COL1A1 that are significantly associated with otosclerosis in the Caucasian population. These haplotypes alter reporter gene activity in an osteoblast cell line by affecting binding of transcription factors to cis-acting elements. Our data suggest that increased amounts of collagen alpha1(I) homotrimers are causally related to the development of otosclerosis. Consistent with this hypothesis, mouse mutants homozygous for a Col1a2 frameshift mutation on a C57BL/6J background that deposit only homotrimeric type I collagen have hearing loss.

[Sports under the sun]. / Les sports sous le soleil.

The outdoor sports during summer and winter are often performed under uncontrolled exposure to ultraviolet irradiation from sunlight. Dangers are not small for the skin, the eyes and the immune system. Adequate sun protection is recommended. Caution is important in young children. The daily UV index represents a standardized assessment having a regional predictive value for the intensity of the ultraviolet irradiation reaching the biosphere.

Attitude of laboratory personnel towards accreditation.

A multiple choice questionnaire was submitted to medical technologists in three medical laboratories, at varying times after obtaining an EN 45001 accreditation. A large majority (85-90 per cent) considered that their workload was increased by the accreditation process. In two laboratories, the technologists did not think that the accreditation process had improved the quality of the results. The major advantages were the fact that everything was traceable, that the technologists felt more sure about the procedures to follow, received more responsibilities and had a better knowledge of the tests they performed. The major disadvantages were the increased paperwork, discrepancies between the procedures and the reality, the fact that more attention is paid to the formalities than to the quality of the results and that the accreditation process decreased the adaptability. The number of advantages mentioned seemed to increase with the interval since the accreditation. A small majority of the technologists preferred working in an accredited laboratory than in a non accredited one.

Evaluation of dowel space preparation on the apical seal using an image processing system.

The effect of post preparation on the apical seal of endodontically treated specimens was studied. The canals prepared in bovine bone were instrumented and obturated using five obturation techniques: the silver point technique, the lateral condensation of gutta-percha technique, the warm vertical condensation of gutta-percha technique, the Hygenic Ultrafil injection system and the Obtura technique. In addition to these five control groups, the five experimental groups were also subjected to post preparation. In the latter group, the gutta-percha was removed with an engine-driven root canal reamer 48 hours after obturation. Both the control and experimental groups were suspended in a 0.5 per cent crystal violet solution for 48 hours. After dye penetration, the specimens were immersed in liquid nitrogen and then split longitudinally. Linear measurements of the resultant apical dye leakage were determined by image processing. For each obturation technique, all specimens in both the control and experimental groups were recorded if they showed leakage. Using Fisher's exact probability test, it was shown that there was no significant difference between the obturation techniques used.