Equine non-invasive time-lapse imaging and blastocyst development.

In this study we examined the timeline of mitotic events of invitro-produced equine embryos that progressed to blastocyst stage using non-invasive time-lapse microscopy (TLM). Intracytoplasmic sperm injection (ICSI) embryos were cultured using a self-contained imaging incubator system (Miri®TL; Esco Technologies) that captured brightfield images at 5-min intervals that were then generated into video for retrospective analysis. For all embryos that progressed to the blastocyst stage, the initial event of extrusion of acellular debris preceded all first cleavages and occurred at mean (±s.e.m.) time of 20.0±1.1h after ICSI, whereas 19 of 24 embryos that did not reach the blastocyst stage demonstrated debris extrusion that occurred at 23.8±1.1h, on average 4h longer for this initial premitotic event (P<0.05). Embryos that failed to reach the blastocyst stage demonstrated a 4-h delay compared with those that reached the blastocyst stage to reach the 2-cell stage (P<0.05). All embryos that reached the blastocyst stage expressed pulsation of the blastocyst with visible expansion and contraction at approximate 10-min intervals, or five to six times per hour. Using a logit probability method, we determined that 2- and 8-cell stage embryos could reasonably predict which embryos progressed to the blastocyst stage. Together, the results indicate that TLM for equine embryo development is a dynamic tool with promise for predicting successful embryo development.

Cost-effectiveness of raising HDL cholesterol by adding prolonged-release nicotinic acid to statin therapy in the secondary prevention setting: a French perspective.

AIM: To evaluate the cost-effectiveness of raising high-density lipoprotein cholesterol (HDL-C) with add-on nicotinic acid in statin-treated patients with coronary heart disease (CHD) and low HDL-C, from the French healthcare system perspective. METHODS AND RESULTS: Computer simulation economic modelling incorporating two decision analytic submodels was used. The first submodel generated a cohort of 2000 patients and simulated lipid changes using baseline characteristics and treatment effects from the ARterial Biology for the Investigation of the Treatment Effects of Reducing cholesterol (ARBITER 2) study. Prolonged-release (PR) nicotinic acid (1 g/day) was added in patients with HDL-C < 40 mg/dl (1.03 mmol/l) on statin alone. The second submodel used standard Markov techniques to evaluate long-term clinical and economic outcomes based on Framingham risk estimates. Direct medical costs were accounted from a third party payer perspective [2004 Euros (euro)] and discounted by 3%. Addition of PR nicotinic acid to statin therapy resulted in substantial health gain and increased life expectancy, at a cost well within the threshold (< 50,000 euros per life year gained) considered good value for money in Western Europe. CONCLUSIONS: Raising HDL-C by adding PR nicotinic acid to statin therapy in CHD patients was cost-effective in France at a level considered to represent good value for money by reimbursement authorities in Europe. This strategy was highly cost-effective in CHD patients with type 2 diabetes.

A health economic model to determine the long-term costs and clinical outcomes of raising low HDL-cholesterol in the prevention of coronary heart disease.

OBJECTIVES: The aim of this study was to describe a health economic model developed to project lifetime clinical and cost outcomes of lipid-modifying interventions in patients not reaching target lipid levels and to assess the validity of the model. METHODS: The internet-based, computer simulation model is made up of two decision analytic sub-models, the first utilizing Monte Carlo simulation, and the second applying Markov modeling techniques. Monte Carlo simulation generates a baseline cohort for long-term simulation by assigning an individual lipid profile to each patient, and applying the treatment effects of interventions under investigation. The Markov model then estimates the long-term clinical (coronary heart disease events, life expectancy, and quality-adjusted life expectancy) and cost outcomes up to a lifetime horizon, based on risk equations from the Framingham study. Internal and external validation analyses were performed. RESULTS: The results of the model validation analyses, plotted against corresponding real-life values from Framingham, 4S, AFCAPS/TexCAPS, and a meta-analysis by Gordon et al., showed that the majority of values were close to the y = x line, which indicates a perfect fit. The R2 value was 0.9575 and the gradient of the regression line was 0.9329, both very close to the perfect fit (= 1). CONCLUSIONS: Validation analyses of the computer simulation model suggest the model is able to recreate the outcomes from published clinical studies and would be a valuable tool for the evaluation of new and existing therapy options for patients with persistent dyslipidemia.

Noninvasive orthogonal polarization spectral imaging as applied to microvascular studies in mice.

In vivo observations of the mouse microcirculation can hardly be performed due to technical difficulties, limiting the knowledge that could be obtained from gene manipulated mice models. The aim of the present study was to check the applicability of a novel optical system, the orthogonal polarization spectral technology, to study the mouse microcirculation. In anaesthetized mice, the spinotrapezius muscle microcirculation was observed in situ. The diameter of precapillary arterioles was measured before and after a pharmacological or hormonal stimulation. High-contrast images of the muscle microcirculation were obtained and significant vasodilatation of arterioles was observed after topical applications of acetylcholine, sodium nitroprusside, and insulin. As compared to conventional techniques, orthogonal polarization spectral imaging makes it possible to assess and study microvascular beds in mice, which were inaccessible until now, allowing the use of gene manipulated mice to investigate, for example, the mechanisms involved in the development of diabetic microangiopathy.

Effect of glycated LDL on microvascular tone in mice: a comparative study with LDL modified in vitro or isolated from diabetic patients.

AIMS/HYPOTHESIS: In vitro studies have suggested that glycation of LDL might be implicated in diabetic microangiopathy. We therefore investigated the in vivo effects of LDL glycated in vitro on the mouse skeletal muscle arteriolar tone. Since glycation naturally occurs during diabetes, we also tested the effects of LDL isolated from diabetic patients. METHODS: In anaesthetized mice, the spinotrapezius muscle microcirculation was observed, in situ, using the orthogonal polarization spectral imaging technology. The diameter of terminal (<20 microm) and small arterioles (20-40 microm) was measured before and after a bolus intravenous injection of glycated LDL followed by a continuous perfusion (115 micro g/kg/min). RESULTS: A slight decrease of terminal and small arterioles diameter (<10%) was observed with native LDL and LDL isolated from healthy subjects. In contrast, mildly glycated LDL induced a clear vasoconstriction of arterioles (>15%), which was further increased when highly glycated LDL was perfused (>22%). LDL isolated from diabetic patients mimicked the vasoconstriction obtained with in vitro mildly glycated LDL, which underwent similar glycation as those isolated from diabetic patients. CONCLUSION/INTERPRETATION: Our results show in vivo that acute perfusion of both types of glycated LDL (artificially or naturally modified), cause major microvascular modification by enhancing arteriolar tone in skeletal muscle. These findings highlight a new role of glycated LDL at the level of microvessels. We suggest that glycation of LDL could contribute to the impaired vascular reactivity observed in diabetes.

Ultrasonographic anatomy and biometric analysis of the thoracic and abdominal organs in healthy foals from birth to age 6 months.

Knowledge of normal renal parameters, as documented in mature horses, is essential for the accurate evaluation of abnormal kidneys. Although the ultrasonographic appearance and location of the abdominal organs in foals and the renal dimensions in neonates have been reported, there is currently no information available for the assessment of normal organ growth in foals. The objectives of the study were to describe the ultrasonographic characteristics, location and variations of the thoracic and abdominal organs with relation to age, height and weight; and provide a growth table for comparison with diseased foals. The thoracic and abdominal cavities of 10 healthy foals were evaluated at ages 1, 7, 14 and 21 days and 1, 2, 3, 4, 5 and 6 months. The equipment used was an Ausonics Opus Plus ultrasound. For every evaluation, weight and height were obtained, the foals were sedated and the area of study was clipped and cleaned. The ultrasonographic location, appearance and measurements of the different organs were recorded for each examination. The study revealed that foals age >1 month resemble the mature ultrasonographic pattern. Continual growth of the organs was observed from Day 1 to age 6 months, being faster in the first month. Organ growth was closely correlated with age, but not with sex, height or weight in healthy foals up to age 6 months. Our study has provided measurements of longitudinal organ growth in healthy foals, presented in a simple form for easy comparison with diseased individuals.

[Telemetry: the importance of surgical aspects]. / Télémétrie: l'importance des aspects chirurgicaux.

Telemetry allows the monitoring of multiple parameters, such as blood pressure, temperature, motor activity and ECG, without any stressful handling or restraint. The invasive phase (i.e. the surgical implantation of a transmitter), which takes place before the start of the study, is of critical importance. Good surgical techniques as described below are essential. All risks of trauma or infection should be avoided, particularly if the animals are to be used in long-term studies. The utility of telemetry may be complemented with other atraumatic techniques, for instance the use of indwelling i.v. infusion catheters allowing long-term studies without any extrinsic stress resulting from the dosing procedure or routine examinations.

Property rights and privacy principles.

Healthcare consumers own their medical information. As paper medical folders become digital, protection of this private and confidential information falls to information specialists rather than the traditional care givers. On the basis of a nationwide market assessment study, the authors identify the key issues regarding protecting this personal digital property and outline the federal requirements stemming from the Health Insurance Portability and Accountability Act (HIPAA). Consumer informed consent over the use of specific medical data is a basic requirement, and is a concept supported by physicians and care givers who rely on consent to approve surgeries and treatment. The article concludes with a solution outline that places the patient in control of his or her personal information, meets security and privacy concerns, and facilitates the critical exchange of patient information among care givers.

Evaluation of equine fetal growth from day 100 of gestation to parturition by ultrasonography.

Transrectal and transabdominal ultrasonography were performed on normal pregnant mares (n=10) at 2 week intervals from day 100 of gestation to parturition to evaluate fetal growth. Several fetal anatomical regions (head, eye, aorta, abdomen, rib, gonad, kidney and femur) were imaged and measured using standardized scan plans. The results of these analyses indicate that all of the biometric parameters correlate strongly with the day of gestation. Growth charts were developed, which demonstrate that the following variables have linear relationships with the day of gestation on which they were measured: aortic systolic diameter, biparietal diameter, approximate eye volume, femur length and kidney cross-sectional area. The linear regression equation across days was developed for aortic, systolic and biparietal diameter, approximate eye volume, femur length and kidney cross-sectional area, thus allowing assessment of normal equine fetal development after day 100 of gestation. This non-invasive method can be used to estimate fetal age if mating or ovulation dates are unknown, provided the fetus is developing normally. The use of transrectal and transabdominal ultrasonography, as well as different probe frequencies (5.0 or 3.5 MHz), to measure different biometric parameters during gestation is reported.

Transabdominal ultrasonographic determination of fetal gender in the horse during mid-gestation.

Gender determination of the equine fetus using transabdominal ultrasonography was studied in 20 mares. One group of 10 research mares was scanned repeatedly every 2 weeks from 100 days gestation to parturition, while the second group of 10 client mares was subjected to echography once during mid-gestation. In males, the penis and/or prepuce was observed on 71 occasions from 102 days to 258 days gestation. On cross-sectional views, the male external genitalia had a round shape with parallel linear echogenic foci up to approximately 140 days gestation and then appeared triangular. Fetal testes were oval in shape in frontal view and had an homogeneous ultrasonographic appearance. Females were diagnosed on 23 occasions from 118 days to 227 days gestation based on the presence of the mammary glands and teats. Fetal ovaries appeared homogeneous with a characteristic circular echo from 100 days to 134 days gestation. Gender identifications (n = 98) based on the presence of the penis and/or prepuce in males and mammary glands and teats or fetal gonads in females were all correct, in agreement with the sex of the foals at birth. The optimal window of time was defined in both sexes as 100 to 220 days gestation. Thereafter, it was increasingly difficult to identify the anatomical structures cited above. Fetal sex was mainly determined using the transabdominal approach (87/98). However, the transrectal approach was useful in cases in which fetuses were either in posterior presentation or located very high in the mares abdomen. Good quality diagnostic scanners used typically in equine reproduction and equipped with a 5.0 MHz probe can be used for this procedure up to 160 days gestation, after which a 3.5 MHz transducer is often necessary due to increasing fetal size.

Impaired microvascular responses to acute hyperglycemia in type I diabetic rats.

Abnormal reactivity of resistance vasculature may induce long-term alterations in regional hemodynamics, contributing to the pathogenesis of diabetic microangiopathy. The purpose of this study was to examine the responses of microvessels to a hyperglycemic episode aimed at mimicking a physiological stimulus such as the postprandial state. This study is the first to report the direct, in situ, visualization of this situation by intravital microscopy in the skeletal muscle of diabetic rat and is particularly interesting as it applies to an iterative, physiological stimulus. The study was conducted in 5-month-old rats, either nondiabetic (ND) or rendered diabetic (D) for 12 weeks (streptozotocin, 60 mg/kg, i.v.). Intravital microscopy was used to examine diameter and vasomotion changes in precapillary arterioles (< 20 microm) in the spinotrapezius muscle of fasted, anesthetized rats, before and up to 60 min after infusion of glucose or isotonic saline. After intravenous glucose infusion, a precapillary arteriolar vasoconstriction associated with an increase in the number of arterioles presenting vasomotion were seen in ND rats. In contrast, no modification in either parameter was observed in D rats. Our results indicate that, microvessels react to acute changes in the metabolic environment such as induced by elevation of plasma glucose. There was a complete loss of reactivity (vasoconstriction and vasomotion) of precapillary arterioles to superimposed hyperglycemia in D rats. According to the "hemodynamic hypothesis", this impaired vasoconstriction could result in hyperperfusion of microvessels and subsequent microvascular damages which might contribute to the development of diabetic microangiopathy.

Hyperglycaemia modifies the reaction of microvessels to insulin in rat skeletal muscle.

The role played by glucose and/or insulin in local vascular regulation of tissue glucose uptake is largely unknown. Thus, the aim of this study was to examine microvascular changes induced either by hyperinsulinaemia alone or in combination with hyperglycaemia. The effects of insulin or glucose on the diameter and periodic vasomotion of precapillary arterioles (diameter < 20 microm) were determined by using the spinotrapezius muscle preparation in fasted, anaesthetized rats. Ten minutes after s.c. insulin administration, the blood insulin level was greatly increased whereas plasma glucose remained unchanged. This was associated with a marked and durable vasodilation of terminal arterioles without significant changes in vasomotion. When similar plasma insulin levels were attained by glucose infusion, tissue glucose uptake was increased in spite of a partial constriction and increased vasomotion of precapillary arterioles. Importantly, local tissue blood flow was not reduced despite the diminution in microvascular diameters. These results indicate that hyperinsulinaemia alone produces an increase in the diameter of terminal arterioles. This effect seems to be offset when the same level of hyperinsulinaemia is associated with hyperglycaemia (such as occurs postprandially), as illustrated by vasoconstriction of the muscle terminal arterioles. Our data suggest that the vasoconstriction of precapillary arterioles may be part of an active regulation for optimal glucose supply to the tissue in acute hyperglycaemic episodes. These data provide the first direct evidence that insulin and glucose can act as regulators of microflow in the skeletal muscle, as illustrated by changes in precapillary haemodynamics.

Ultrasonographic evaluation of the equine placenta by transrectal and transabdominal approach in the normal pregnant mare.

The objective of this study was to determine normal variations in the utero placental thickness during mid- and late gestation in the mare. Normal, healthy pregnant mares (n = 9) were examined monthly from 4 mo of gestation until parturition by transrectal and transabdominal ultrasonography. At each examination, the combined thickness of the uterus and the placenta (CTUP) was measured at the placento-cervical junction (transrectally) and at the uterine body or the uterine horns (transabdominally). In addition, the echogenicity of the amniotic and allantoic fluids was evaluated by transrectal ultrasonography. Following parturition and expulsion of the fetal membranes, the allantochorion was measured and visually examined for abnormalities. At all examinations, both transrectal and transabdominal, the chorioallantois and the uterus were indistinguishable from each other on the ultrasound image. The CTUP, measured by transrectal ultrasonography did not change between 4 and 8 mo of gestation, but increased significantly for each month between 10 and 12 mo of gestation (P < 0.001). A change in the CTUP was detected between months when measured by transabdominal ultrasonography, but no distinct pattern in these changes was observed. No correlation was found between transabdominal and transrectal measurements of the CTUP. The echogenicity of the amniotic and allantoic fluids did not consistently change over time during mid- and late gestation. The amniotic fluid was more echogenic than the allantoic fluid at most examinations from 6 mo of pregnancy and throughout gestation (P < 0.05). It was concluded that transrectal ultrasonographic examination to assess the CTUP and the echogenicity of the fetal fluids is superior to the transabdominal approach. We suggest that transrectal ultrasonographic examination should be added to current diagnostic tools during late gestation and that it be part of the biophysical profile of high risk equine pregnancies.

Silica attenuates hypertension in Lyon hypertensive rats.

BACKGROUND AND OBJECTIVE: Evidence has been provided suggesting an association between hypertension and immune dysfunction in Lyon hypertensive (LH) rats. In the present study, we investigated the possible role played by macrophages in LH rats by examining the blood pressure consequences of the chronic administration of silica, a selective toxin to macrophages in vivo. DESIGN AND METHODS: LH and Lyon low blood pressure (LL) male rats were treated with silica at a dose of 200 mg/kg per week intraperitoneally from age 4-10 weeks. Controls received saline. Blood pressure was measured by plethysmography from age 6-10 weeks and an intra-arterial recording was performed in 11-week-old, freely moving rats. RESULTS: Treatment with silica did not modify blood pressure in LL rats at any age. In contrast, 1 week after the beginning of the treatment, the blood pressure of silica-treated LH rats was lower than that of untreated LH rats. As shown by intra-arterial recording, the effect persisted 1 week after cessation of the treatment. In addition, silica decreased the left ventricle weight in LH but not in LL rats. CONCLUSION: The present results show that weekly administration of silica in young LH rats attenuates the development of hypertension and of left ventricular hypertrophy, a finding which suggests that macrophage-mediated immune reactions may play a pathogenic role in LH rats.

Partial transfer of genetic hypertension by lymphoid cells in Lyon rats.

BACKGROUND AND OBJECTIVE: The involvement of immune factors in a given disease is suggested by evidence that a disease can be prevented by immunosuppression and can be transferred by lymphoid cells. Because the first type of experimental result was achieved in Lyon hypertensive (LH) rats, the present study was undertaken to determine whether hypertension can be transferred to normotensive recipients. As a control, the blood pressure effects of lymphoid cell grafts from renovascular hypertensive donors were also determined. DESIGN AND METHODS: Splenocytes and lymph node cells from LH and Lyon low-blood pressure (LL) rats with two-kidney Goldblatt hypertension were respectively injected into LH x Lyon normotensive (LN) F1 hybrids and LL rats aged 7, 8, 9 and 10 weeks. Blood pressure was measured by plethysmography from age 6 to 13 weeks and an intra-arterial recording was performed in 14-week-old conscious rats. RESULTS: Lymphoid cell injections from LL rat donors with two-kidney hypertension did not modify the blood pressure of LL rat recipients. In contrast, lymphoid cell grafts from LH rat donors induced a significant increase in blood pressure in F1 recipients compared with control F1 rats after the first injection. As confirmed by intra-arterial recording, this blood pressure effect lasted until age 14 weeks (145 +/- 1 versus 137 +/- 1 mmHg in grafted and ungrafted F1, respectively). It was not related to alterations in the acute role of the renin-angiotensin and sympathetic nervous systems and was not associated with increased pressor responses to the vasoconstrictor drugs tested. CONCLUSION: The present study demonstrates that genetic hypertension can be partially transferred by lymphoid cells in F1 recipients. The effect seems to be specific to genetic hypertension because lymphoid cells from renovascular hypertensive donors failed to transfer this secondary form of hypertension. The present results support the hypothesis that cellular immune reactions contribute to the pathogenesis of hypertension and LH rats.

Coronary arteries: new design for three-dimensional arterial phantoms.

Few three-dimensional (3D) anthropomorphic phantoms are available for testing 3D reconstruction and quantitation of vessels. The authors built a new realistic model of arteries with use of stereolithography, a computer-aided design and computer-aided manufacturing technique. Each phantom is composed of the physical object and its digital "twin." The entire coronary artery tree and complex stenoses were manufactured with a precision below 0.1 mm.

Image quality study in 3D X-ray angiography: a first approach using the experimental design strategy.

The visual detection of fine structures and the accuracy of the quantitation of geometric and densitometric features, are closely related to the quality of the images available in two-dimensional (2D) and three-dimensional (3D) X-ray angiography. In this context, we propose to analyze all the parameters influencing this accuracy using an experimental design strategy. Preliminary tests of this procedure, applied to 2D and 3D angiographic data obtained from a dedicated phantom, yield encouraging results. We show that the detection of small arteries in a 3D angiogram is more sensitive to the number of projections than to the X-ray dose.