A single-cell micro-trench platform for automatic monitoring of cell division and apoptosis after chemotherapeutic drug administration.

Cells vary in their dynamic response to external stimuli, due to stochastic fluctuations and non-uniform progression through the cell cycle. Hence, single-cell studies are required to reveal the range of heterogeneity in their responses to defined perturbations, which provides detailed insight into signaling processes. Here, we present a time-lapse study using arrays of micro-trenches to monitor the timing of cell division and apoptosis in non-adherent cells at the single-cell level. By employing automated cell tracking and division detection, we precisely determine cell cycle duration and sister-cell correlations for hundreds of individual cells in parallel. As a model application we study the response of leukemia cells to the chemostatic drug vincristine as a function of cell cycle phase. The time-to-death after drug addition is found to depend both on drug concentration and cell cycle phase. The resulting timing and dose-response distributions were reproduced in control experiments using synchronized cell populations. Interestingly, in non-synchronized cells, the time-to-death intervals for sister cells appear to be correlated. Our study demonstrates the practical benefits of micro-trench arrays as a platform for high-throughput, single-cell time-lapse studies on cell cycle dependence, correlations and cell fate decisions in general.

Extradural spinal hydatid cyst causing hindlimb ataxia in a horse.

INTRODUCTION: This case report describes a 13-year-old cob-cross gelding presented for evaluation of recent onset hindlimb ataxia. The gelding had undergone general anaesthesia and tenoscopy of the right hindlimb digital flexor tendon sheath at a nearby clinic three months earlier and had appeared normal at routine post-operative assessments until the sudden onset of neurological deficits. Spinal trauma was suspected initially but radiography and scintigraphy were unremarkable. Due to the severity and progressive nature of the clinical signs the -gelding was subjected to euthanasia. Post mortem examinations (computed tomography, dissection and histopathology) revealed spinal cord compression caused by a single extradural hydatid cyst (Echinococcus equinus), confirmed with PCR, at the level of the 15th thoracic vertebra. This is the first report of a spinal hydatid cyst causing hindlimb ataxia and should therefore be considered a potential differential diagnosis for ataxia in the equine patient.

INTRODUCTION: Ce rapport décrit le cas d'un hongre croisé cob de 13 ans présenté pour l'évaluation d'une ataxie des membres postérieurs d'apparition récente. Le hongre avait subi une anesthésie générale et une ténoscopie de la gaine du tendon du fléchisseur digital du membre postérieur droit dans une clinique voisine trois mois auparavant et avait semblé normal lors des évaluations postopératoires de routine jusqu'à l'apparition soudaine de déficits neurologiques. Un traumatisme rachidien était suspecté au départ, mais la radiographie et la scintigraphie étaient sans particularité. En raison de la gravité et de la nature progressive des signes cliniques, le hongre a été euthanasié. Les examens post mortem (tomodensitométrie, dissection et histopathologie) ont révélé une compression de la moelle épinière provoquée par un unique kyste hydatique extradural (Echinococcus equinus), confirmé par PCR, au niveau de la 15e vertèbre thoracique. Il s'agit du premier cas rapporté d'un kyste hydatique au niveau de la colonne vertébrale causant une ataxie des membres postérieurs et doit donc être considéré comme un diagnostic différentiel potentiel de l'ataxie chez le patient équin.

Ultrasonographic assessment of the atlanto-occipital space in healthy Thoroughbred foals and Thoroughbred foals with neonatal maladjustment syndrome.

Ultrasonography of the atlanto-occipital (AO) space may be useful as a non-invasive diagnostic tool in neonatal foals. The aims of the study were establish a range of values for ultrasonographic measurements of the AO space in healthy Thoroughbred foals and to compare these variables in healthy foals with foals diagnosed with neonatal maladjustment syndrome (NMS). Ultrasonography of the AO space was performed on 38 healthy Thoroughbred foals and 28 Thoroughbred foals with NMS≤4days of age. Transverse image spinal cord height (P=0.001), width (P<0.001) and spinal cord cross sectional area (P<0.001), and longitudinal image dorsoventral diameter of the ventral spinal artery, were significantly smaller in foals with NMS than in healthy foals. Ratios of spinal canal to cord width and cross sectional area were significantly smaller in healthy foals than in foals with NMS (P<0.001). Spinal canal variables were not significantly different between groups. Several ultrasonographic measurements of the AO space were significantly different between healthy foals and foals with NMS. Further investigation is warranted to investigate the clinical application of this technique.

The effect of mare obesity and endocrine function on foal birthweight in Thoroughbreds.

BACKGROUND: Birthweight of Thoroughbred foals has increased in recent years. It is unknown whether this is associated with increased broodmare obesity or endocrine dysfunction. OBJECTIVES: To determine insulin, leptin and triglyceride concentrations in Thoroughbred mares throughout gestation and investigate their association with obesity and foal birthweight. STUDY DESIGN: Cohort study. METHODS: A total of 66 mares were included from 40 days post-breeding. Body condition score (BCS), weight and blood samples were obtained every 60 days throughout gestation. Serum/plasma insulin, leptin and triglyceride concentrations and foal birthweight were recorded. Associations between hormone/triglyceride concentration with BCS, stage of gestation and birthweight were analysed using a linear mixed effects model. RESULTS: Serum insulin concentrations were greater at 1-60 days (4.31 µiu/mL) compared with 241-300 days (3.13 µiu/mL) and 61-120 days (5.33 µiu/mL) compared with 181-240, 241-300 and 301-360 days (3.78, 3.13, 3.37 µiu/mL) gestation (P<0.05). There was no significant hyperinsulinaemia and no association of insulin concentration with BCS. Leptin concentration was greater at 181-240 days (2.28 µg/L, P<0.0001) compared with all other time points and correlated with BCS (P<0.0003). Triglyceride concentration was greater at 241-300 days (0.245 mmol, P<0.02) compared with earlier time points, but was not associated with BCS. Foal birthweight was weakly positively correlated with BCS (r = 0.13, P<0.001) and inversely correlated with leptin concentrations at 61-120 and 241-300 days gestation (r = -0.64, P<0.05). MAIN LIMITATIONS: Reduction in sample size over the study and tight clustering of BCS. CONCLUSIONS: Mare BCS correlated with foal birthweight; obese mares had heavier foals. Significant hyperinsulinaemia was not identified in this population. Increased leptin concentration in early and late gestation was associated with decreased foal birthweight. Further work is required to establish whether leptin concentration in late gestation could predict foal birthweight.

Clinical Research Abstracts of the British Equine Veterinary Association Congress 2015.

REASONS FOR PERFORMING STUDY: Atrial fibrillation is a common equine arrhythmia. Quinidine alone, or with digoxin are common treatments. Studies on outcome in Warmblood populations in which duration of the AF is often unknown are limited. OBJECTIVES: To identify the factors that are associated with the success of full treatment cardioversion with oral medication, and establish whether there are differences in these factors between institutions. STUDY DESIGN: Retrospective case series using patient records of Equine University Clinic of Utrecht University and Rossdales Equine Hospital, Newmarket. METHODS: Forty-nine horses treated with quinidine were identified (29 Warmbloods, 20 Thorougbreds, 1 Anglo-Arabian). Details of signalment, history, duration physical examination and echocardiography including left atrial size and presence of mitral regurgitation were retrieved. Clinical details including mean weight, age and left atrial size were compared between clinics using independent samples t test. Association between variables and cardioconversion were evaluated in a backwards logistic regression using Akaike's information criterium (AIC) and odds ratios were calculated. Factors were sex, clinic, breed, mitral regurgitation, duration and poor performance. Covariates were age, weight and the size of the left atrium. Significance was set at 0.05. RESULTS: Fifty-one horses (mean age 8.8 s.d. 4.5 years) were treated with quinidine sulfate, 18 also received digoxin. Eighty per cent converted to sinus rhythm. In 8 horses the known duration was less than 3 months. The only factor associated with successful treatment was the use of digoxin in combination with quinidine sulfate (odds ratio 12.4; 95% CI 2.61 and 91.85 according to AIC analysis). CONCLUSIONS: In this retrospective case series, there is much potential for bias in the data; however, the use of digoxin in addition to quinidine was associated with improved conversion rates regardless of breed even though AF duration was unknown in most horses. Ethical animal research: Research ethics committee oversight not currently required by this conference: retrospective study of clinical records. Explicit owner informed consent for inclusion of animals in this study was not stated. SOURCE OF FUNDING: None. Competing interests: None declared.

Clinical Research Abstracts of the British Equine Veterinary Association Congress 2015.

REASONS FOR PERFORMING STUDY: The birthweight of Thoroughbred foals has increased in recent years. It is unknown whether this is associated with increased broodmare obesity or endocrine dysfunction. OBJECTIVES: To determine insulin, leptin and triglyceride concentrations in obese and non-obese Thoroughbred mares throughout gestation and to investigate their association with foal birthweight. STUDY DESIGN: Prospective, cohort study. METHODS: Fifty-seven pregnant Thoroughbred mares were included in the study. From 40 days post-breeding, body condition score (BCS), weight and venous blood samples were obtained every 60 days throughout gestation. Feed was withheld for 6 h before blood sampling. Serum/plasma insulin, leptin and triglyceride concentrations were measured using validated/standard methods. Foal birthweight was recorded. Association of hormone or triglyceride concentration with time, BCS and birthweight were analysed using a linear mixed effects model. A Pearson correlation co-efficient was calculated between hormone or triglyceride concentration, BCS and birthweight. RESULTS: Serum insulin concentrations were significantly greater (P<0.05) at 0-59 days compared with 240-299 days and at 60-119 days compared with 180-359 days gestation. 55% of mares had BCS ≥ 7. There was 1.5% incidence of fasting hyperinsulinaemia throughout gestation and no association of fasting insulin concentration with BCS. Leptin concentration was significantly (P<0.0001) greater at 180-239 days compared with all other time points and was significantly (r = 0.29, P<0.0003) correlated with BCS. Triglyceride concentration was significantly (P<0.02) greater at 240-299 days compared with earlier time points but was not associated with BCS. Foal birthweight was significantly positively correlated with BCS (r = 0.13, P<0.001) and inversely correlated with leptin concentration at 60-119 days and 240-299 days gestation (r = -0.64, P<0.05). CONCLUSIONS: Mare BCS correlated with foal birthweight such that obese mares had heavier foals. Significant fasting hyperinsulinaemia was not identified in this population. Increased leptin concentration in early and late gestation was associated with decreased foal birthweight and may be useful to predict foal birthweight. Ethical animal research: Informed client consent was obtained for all animals used in the study. SOURCE OF FUNDING: Private donor. Competing interests: None declared.

Spinal fusion in girls with Rett syndrome: post-operative recovery and family experiences.

BACKGROUND: Rett syndrome is a severe neurodevelopmental disorder mainly affecting females and scoliosis is a common co-morbidity. Spinal fusion may be recommended if the scoliosis is progressive. This qualitative study investigated recovery of girls with Rett syndrome during the first 12 post-operative months and explored family perspectives and coping around the time of surgery. METHOD: Parents registered with the population-based Australian Rett Syndrome Database were recruited to this study if their daughter had a confirmed pathogenic MECP2 mutation and spinal fusion between 2006 and 2012. Twenty-five interviews were conducted to determine their daughter's recovery and parental stresses and coping. Themes in the interview data were identified with content analysis, and the regaining of gross motor skills over the first 12 post-operative months was described with time-to-event (survival) analysis. RESULTS: Pain and energy levels, appetite, mood and coinciding health issues influenced their daughter's post-operative recovery. The majority of girls recovered preoperative sitting (88%), standing (81%) and walking (80%) by 12 months. The decision to proceed with surgery was associated with feelings of fear, obligation, relief and guilt for families. Development of complications, poor support and feelings of isolation increased their emotional burden whereas adequate information and discharge preparation, confidence in self and staff, and balancing personal needs with their daughter's care relieved this burden. INTERPRETATION: Our study identified clinical practice issues in relation to families whose daughter with Rett syndrome undergoes spinal fusion, issues that are also relevant to other severe disabilities. Return of wellness and gross motor skills following spinal fusion in girls with Rett syndrome occurred within the first 12 post-operative months in most cases. Parents require information and practical support to alleviate their emotional burden.

Pneumocephalus in five horses.

Pneumocephalus is occasionally encountered in horses but poorly described in the literature. The study aimed to describe historical, clinical and diagnostic imaging findings and outcome in horses to increase the awareness and recognition of the condition amongst equine practitioners, allowing appropriate management of these cases. Cases of pneumocephalus from 4 participating institutions were identified and case details extracted from the medical records. Five cases of pneumocephalus were identified. Head trauma with suspected or confirmed fractures of the sinuses was the underlying cause in 4 cases, while the remaining horse was thought to have developed pneumocephalus secondary to sinusitis or trauma. Diagnosis was established radiographically in 4 cases and by computed tomography in a fifth. Gas was noted between the cranial vault and the brain, in the lateral ventricles, in the brain parenchyma and within the cranial cervical canal. The gas accumulation resolved gradually in all horses and did not appear independently to result in neurological compromise. Long-term outcome was available for 3 cases, 2 of which were ultimately subjected to euthanasia due to neurological deficits. Pneumocephalus is a possible consequence of head trauma or sinusitis in horses; although the finding is frequently incidental, it has the potential to develop into a life-threatening complication. Imaging the complete skull and cranial cervical spine is important to allow identification and appropriate management of these cases. The use of computed tomography enables easier identification and localisation of the gas accumulation within the central nervous system.

Traditional and quantitative assessment of acid-base and shock variables in horses with atypical myopathy.

BACKGROUND: Descriptions of acid-base disturbances in atypical myopathy (AM) are limited. OBJECTIVES: Describe and compare traditional and quantitative acid-base abnormalities and cardiovascular shock status in horses with AM at admission. ANIMALS: 34 horses with AM, 15 healthy controls. METHODS: Retrospective case-control study. Records were searched for shock variables (packed cell volume [PCV], blood urea nitrogen [BUN], heart and respiratory rate) and acid-base variables (venous blood gas analysis, electrolytes, total protein, lactate) on admission. Base excess (BE) of free water (BEfw), chloride (BEcl), total protein (BEtp), and unidentified anions (BEua), anion gap (AG), measured strong ion difference (SIDm), and concentration of total nonvolatile weak acids ([Atot]) were calculated. Acid-base classifications, using simplified strong ion model and traditional approach, and shock grades were assigned. A 2-sample Wilcoxon rank-sum test and Bonferroni correction compared variables in AM cases versus control horses. Significance was P < .05/16 for acid-base and P < .05/5 for shock variables. RESULTS: Tachycardia, tachypnea, and normal to increased PCV and BUN were common in AM cases. Respiratory, metabolic acid-base alterations, or both were mainly caused by respiratory alkalosis, lactic acidosis, and SIDm alkalosis, alone or in combination. Evaluated variables (except pH, potassium concentration, total protein, and related calculations) were significantly different (P < .001) between AM cases and control horses. The strong ion model provided a more accurate assessment than the traditional approach and identified mixed derangements. CONCLUSIONS AND CLINICAL IMPORTANCE: Acid-base derangements should be evaluated in horses with AM and this preferably with the strong ion model.