The Role of Lipid-Lowering Therapy in Post-Stroke Patients: Update and Recommendations.

PURPOSE OF REVIEW: Stroke is the second leading cause of death and disability-adjusted life years worldwide, and the global lifetime risk of stroke is rising. Moreover, patients with a prior stroke are at high risk of recurrent events. We aimed at reviewing the evidence supporting aggressive secondary prevention strategies for lipid-lowering treatment in this population. RECENT FINDINGS: Statins are the key players in such aggressive management; however, stroke survivors remain at significant residual risk suggesting the need for both better implementation of statin use as well as additional lipid lowering therapies. Newer drugs have become available and represent important tools in the management of patients with prior ischemic stroke. The role of lipid lowering treatment in hemorrhagic stroke is more controversial, given epidemiological data linking low lipid levels with increased risk of first and recurrent events. Aggressive secondary prevention strategies, including lipid lowering treatments, have proven to mitigate the risk of recurrent events in post-stroke patients. The tools available for treating such high-risk population have expanded beyond statins, and clinicians should familiarize themselves with them.

Comparison of abdominal obesity measures in predicting of 10-year cardiovascular risk in an Iranian adult population using ACC/AHA risk model: A population based cross sectional study.

BACKGROUND: Several abdominal obesity measures have been used for prediction of 10-year cardiovascular disease (CVD) risk but the superiority of these measures remains controversial. The objective of this study was to assess the predictive ability of abdominal obesity measures for risk of CVD events in an Iranian adult population. METHODS: We analyzed the data of population based cross-section study of 567 representative samples of adult population aged 40-70 years in Babol, the north of Iran. The demographic data, the anthropometric measures, lipid profile and cardiometabolic risk factors were measured with standard methods. Waist to hip ratio (WHR), waist to height ratio (WHtR), conicity index(CI), abdominal volume index (AVI) and body mass index(BMI)were calculated. The individual 10-year CVD risk was estimated based on ACC/AHA model. ROC analysis was performed to assess the diagnostic ability of different abdominal obesity measures and body mass index (BMI) in predicting of high risk of CVD events. RESULTS: About 42.5% of men and 15% of women had at least 10% risk of 10-year cardiovascular events and 21.1% of men and 3.0% of women had ≥20% risk. Except WHR for men, all abdominal obesity measures significant predictors for ≥10% risk CVD risk in both sexes but not BMI. The greater ability of CVD risk prediction was observed by WHtR and CI in both sexes with higher AUC in females compared with men for ≥10% risk. CONCLUSION: WHtR and CI are superior indexes in predicting of high risk of CVD events in both sexes.

Comparison of metformin and N-acetyl cysteine, as an adjuvant to clomiphene citrate, in clomiphene-resistant women with polycystic ovary syndrome.

OBJECTIVE: To evaluate the effects of short- and long-term treatment with metformin and NAC, in an adjuvant to clomiphene citrate (CC), on the improvement of hormonal profile (SHBG, total testosterone, FBS, and fasting insulin) and fertility status in CC-resistant women with PCOS. MATERIALS AND METHODS: One hundred and eight CC-resistant PCOS patients participated in the study and received either metformin (1500mg/day) or NAC (1800mg/day) with 100mg/day of CC for 8 and 12 weeks. Mean BMI, hirsutism score, LH/FSH ratio, endometrial thickness, mature follicle number, and serum concentrations of LH, FSH, E2, fasting insulin, total testosterone and FBS were evaluated before and after short- and long-term treatment. Furthermore, ovulation and pregnancy rates in the first and second cycles were also determined in treated patients. RESULTS: There was no significant difference in all variables before and 8 weeks after treatment with metformin and NAC. The BMI- and insulin-lowering effects of metformin were significantly higher than NAC after long-term treatment. However, the reducing-effect of NAC on hirsutism score and FBS levels was significantly more than metformin after 12 weeks. Treatment with metformin and NAC significantly increased ovulation and pregnancy rates in CC-resistant PCOS patients. In the first and second cycles, ovulation and pregnancy rates in patients treated with NAC were slightly higher than those received metformin. CONCLUSIONS: Compared with metformin, administration of NAC in an adjuvant to CC is recommended for improving of hormonal profile and treatment of anovulatory infertility in hyperinsulinemic patients especially women with PCOS who are CC-resistant.

Clustering of cardio metabolic risk factors in Iranian adult population: A growing problem in the north of Iran.

INTRODUCTION: The clustering of components of metabolic syndrome (MetS) is a major concern in a transition population because of dramatic changing toward modern life styles. The objective of this study was to determine the prevalence of clustering of various combinations of MetS and its association with obesity. METHODS AND SUBJECTS: In a population- based cross-sectional study, a representative samples of 1000 adults were recruited in Babol, the north of Iran. The demographic data, blood pressure, body mass index and waist circumference (WC) were measured with standard method. Fasting blood sugar, serum levels of triglycerides, high density lipoprotein were measured with enzymatic method. RESULTS: A quarter of population had only one component of MetS. The prevalence of just two components was 30.7% and 26.2% in men and women respectively and about 67.1% of men and 73.3% of women had ≥2 risk factors (P=0.001). While the joint prevalence of three and four components was 22.0% and 12.0% in male and 27.3% and 16.5% in female respectively. The combination of high WC with any of other four components of MetS were significantly higher compared with any other joint combinations in particularly among women (P=0.001). The adjusted odds ratio for having clustering (≥2 risk factors) increased 5.6 times (95%CI: 2.15, 6.04) in obese subjects and remained at significant level after adjustment for age, sex, level of education. CONCLUSION: An emerging high rate of clustering of joint combination of cardio metabolic risk factors highlights an urgent intervention for life style modification in public health management.

A comparison of health-related quality of life in patients with renal failure under hemodialysis and healthy participants.

The objective of this study was to evaluate the health-related quality of life (QoL) of patients under hemodialysis (HD) and to compare this to healthy participants. We compared 154 patients on HD to 308 healthy age- and sex-matched controls recruited from Shahid Beheshti Hospital in Babol, Northern Iran in 2014. The data of health-related QoL in eight subscales were collected with interview using a standard short-form questionnaire of short form-36. The demographic data and dry weight and height were measured. The scores of each subscale were transformed from 0 (the worse state) to 100 (the best state). In univariate analysis, Wilcoxon and Kruskal-Wallis tests were used to compare the distribution of scores between cases and controls according to gender, and multiple linear regression analysis was used to adjust the regression coefficient for possible potential confounding factors. The mean overall score of health-related QoL for men was 44.7 ± 23.2 and 74.3 ± 18.1 in patients and controls, respectively, and for women was 37.1 ± 20.8 and 62.1 ± 18.7, respectively. In all subscales, the mean score of patients was significantly lower than controls (P = 0.001) in both sexes. In all eight subscales, after adjusting for demographic characteristics, the patients had significantly lower QoL than controls (P = 0.001). In addition, the independent effect of age, gender, and educational level as predictors of QoL was significant across various subscales (P = 0.001).

Solitary and combined negative influences of diabetes, obesity and hypertension on health-related quality of life of elderly individuals: A population-based cross-sectional study.

AIMS: The health-related quality of life (HRQoL) is a matter of concern in elderly people with chronic diseases. The objective of this study was to investigate the impact of obesity, hypertension and diabetes on HRQoL among elderly. METHODS: A population based cross sectional study was conducted with 750 representative sample of elderly people aged 60-90 years in Babol, the northern Iran. The demographic data and the measurement of blood pressure and other anthropometric measures were collected. The validated short form (SF-36) questionnaire was used to assess the HRQoL. A multiple linear regression model was applied to assess the impact of obesity, abdominal obesity, hypertension and diabetes on QoL. RESULTS: The mean age (SD) of participants was 68.0±7.6 and 67.7±7.9 years for men and women respectively. Diabetes exerted the most negative effect on QoL score (adjusted coefficient=-9.2, 95% CI: -11.7, -6.5 points) followed by abdominal obesity and hypertension. Whereas a combination of three conditions was associated with a greater significant reduction in QoL scores in both sexes(adjusted coefficient=-14.5, 95% CI: -19.0, -9.9 points). However, the negative influence of obesity and hypertension on QoL was significant only in women. CONCLUSION: Most components of the QoL is affected by diabetes, obesity and hypertension particularly in women. Diabetes alone or in combination with other conditions has a negative influence in both sexes with greater effect in women. These findings justify further professional support to compensate the negative influences chronic conditions on health-related QoL especially for older obese diabetic women.

Fasting hyperinsulinaemia and 2-h glycaemia predict coronary heart disease in patients with type 2 diabetes.

AIM: Patients with diabetes are at greater risk of cardiovascular events. Insulin resistance (IR) and hyperinsulinaemia are both related to an increased cardiovascular risk, but whether IR predicts coronary heart disease (CHD) independently of other risk factors in patients with type 2 diabetes (T2D) is a topic of considerable controversy. The aim of the present study was to evaluate the prospective relationship of fasting insulin, HOMA-IR, fasting plasma glucose (FPG) and 2-h post-load glucose (2hPG) load with CHD incidence among such patients. METHODS: A total of 2607 patients with T2D were enrolled in a community-dwelling cohort and followed for an average of 7.2 years. Conventional CHD risk factors, FPG, 2hPG, fasting insulin levels and HOMA-IR index were measured at baseline. Cox regression hazard ratios (HRs) were used to assess CHD risk. RESULTS: A total of 299 'hard' CHD events were registered (in 114 women and 185 men). Increasing levels of fasting insulinaemia were positively associated with CHD incidence. This correlation persisted after controlling for gender, body mass index, blood pressure, lipid profile, medication use and HbA1c [HR for each increase in quartile (fully adjusted model): 1.18 (95% CI: 1.06-1.32); P<0.01]. 2hPG showed a non-linear association with incident CHD [HR of highest vs lowest quartile: 1.64 (95% CI: 1.03-2.61)]. Fasting glycaemia was not associated with CHD risk, whereas HOMA-IR had a direct and independent correlation with CHD risk [HR for each one-quartile increase: 1.19 (95% CI: 1.07-1.34); P<0.01]. CONCLUSION: Fasting insulin levels are positively associated with incidence of CHD in T2D. Furthermore, 2hPG appears to be a significant predictor of incident CHD independently of other risk factors, including HbA1c. These findings suggest that strategies targeting the reduction of insulinaemia and post-load glycaemia may be useful for preventing cardiovascular complications.

Impact of treatment with inhaled corticosteroids on bone mineral density of patients with asthma: related with age.

UNLABELLED: The effect of inhaled corticosteroid on bone mineral density (BMD) was investigated in 44 asthmatic patients after median treatment duration of 6.5 years. Compared with controls, BMD decreased only in patients aged <50 years in both the spine (11.3 %, p = 0.013) and hip (8.8 %, p = 0.044), whereas in patients ≥50 years BMD did not decrease significantly. INTRODUCTION: The results of studies which addressed the impact of inhaled corticosteroid (ICS) therapy on BMD of patients with asthma are conflicting. This case-control study aimed to compare BMD status in ICS user with asthma with healthy controls according to age. METHODS: BMD at the lumbar spine (LS), femoral neck (FN) was measured by dual energy X-ray absorptiometry (DEXA). Patients and controls were compared according to BMD gr/cm(2), BMD T-score, BMD Z-score, frequency of osteoporosis (defined as BMD T-score ≤-2.5), and frequency of patients with BMD Z-score <-1 at LS and FN with regard to age <50 and ≥50 years old. RESULTS: Forty-four ICS user patients (females 63.6 %) with median treatment duration of 6.5 years and 50 controls (females, 69.4 %) with respective mean age of 49.2 ± 9.5 and 47.4 ± 10.5 years (p = 0.38 and p = 0.35) entered the study. Overall LS-BMD and FN-BMD gr/cm2 in total patients were lower than in controls by 6 % (p = 0.065) and 5.9 % (p = 0.09), respectively. In patients <50 years, mean LS-BMD gr/cm(2) was lower than controls by 11.3 % (p = 0.013) and FN-BMD by 8.8 % (p = 0.044). Mean BMD T-score and BMD Z-score in both measurement sites were also lower than controls (p = 0.013 and 0.01, respectively. Frequency of osteoporosis did not differ but frequency of patients with BMD Z-score <-1 was significantly higher in patients (odds ratio (OR) = 6.57 95 % CI, 1.8-23.9, p = 0.004). In age group ≥50 years old, reduction of BMD in both measurement sites did not reach to a significant level. CONCLUSION: This study indicates that BMD reduction in ICS user with asthma is dependent on age and appears that younger patients are at greater risk of BMD loss. These findings suggest preventive measures particularly in patients <50 years.

Prevalence of metabolic syndrome and the association with socio-demographic characteristics and physical activity in urban population of Iranian adults: a population-based study.

BACKGROUND: The metabolic syndrome (MetS) is the main concern of health problem in transition population. The objective was to determine the prevalence of MetS and its association with socio-demographic and physical activity in Iranian adults. METHODS: A population-based cross-sectional study of 1000 representative samples aged 20-70 years was conducted in urban area in northern Iran. The socio-demographic data were collected by interview and the physical activity was assessed by standard International Physical Activity Questionnaire (IPAQ). Weight, height, waist circumference and the systolic and diastolic blood pressures were measured by standard methods. Fasting plasma glucose, triglycerides, total cholesterol, high density lipoprotein-cholesterol level and low density lipoprotein cholesterol level were measured using enzymatic method. The ATP III criteria were used for diagnosis of MetS. RESULTS: The prevalence rate of MetS was 42.3% (36.5% men and 47.1% women, p=0.001). The higher education at university level was appeared inversely associated with MetS (age adjusted OR=0.34, p=0.001) compared with illiterate. The prevalence rates of MetS were 49.0%, 42.5% and 22.6% in low, moderate and vigorous physical activity level respectively (p=0.001). After adjusting for potential confounding factors, the vigorous physical activity was inversely associated with MetS compared with low level (adjusted OR=0.46, p=0.001). CONCLUSION: These results highlight an immediate action of preventive measures programs for modification of cardio metabolic risk factors.

Position-controlled uniform GaAs nanowires on silicon using nanoimprint lithography.

We report on the epitaxial growth of large-area position-controlled self-catalyzed GaAs nanowires (NWs) directly on Si by molecular beam epitaxy (MBE). Nanohole patterns are defined in a SiO2 mask on 2 in. Si wafers using nanoimprint lithography (NIL) for the growth of positioned GaAs NWs. To optimize the yield of vertical NWs the MBE growth parameter space is tuned, including Ga predeposition time, Ga and As fluxes, growth temperature, and annealing treatment prior to NW growth. In addition, a non-negligible radial growth is observed with increasing growth time and is found to be independent of the As species (i.e., As2 or As4) and the growth temperatures studied. Cross-sectional transmission electron microscopy analysis of the GaAs NW/Si substrate heterointerface reveals an epitaxial growth where NW base fills the oxide hole opening and eventually extends over the oxide mask. These findings have important implications for NW-based device designs with axial and radial p-n junctions. Finally, NIL positioned GaAs/AlGaAs core-shell heterostructured NWs are grown on Si to study the optical properties of the NWs. Room-temperature photoluminescence spectroscopy of ensembles of as-grown core-shell NWs reveals uniform and high optical quality, as required for the subsequent device applications. The combination of NIL and MBE thereby demonstrates the successful heterogeneous integration of highly uniform GaAs NWs on Si, important for fabricating high throughput, large-area position-controlled NW arrays for various optoelectronic device applications.

Effect of pre-treatment of ovine sperm on male pronuclear formation and subsequent embryo development following intracytoplasmic sperm injection.

The objective of this study was to determine the effects of various methods of sperm pre-treatment on male pronuclear (MPN) formation and subsequent development of ovine embryos derived from in vitro-matured oocytes and intracytoplasmic sperm injection (ICSI). The effect of treatment of injected oocytes with dithiothreitol (DTT) on embryo development was also assessed. In Exp. 1, the injected oocytes with non-treated sperm were activated with three different procedures. The cleavage and blastocyst rates in those activated with DTT was lower (p<0.05) than those activated with either ionomycin (Io) +6-dimethylaminopurine (6-DMAP) or DTT + I + 6-DMAP. In Exp. 2, the effects of sperm pre-incubated with DTT, sodium dodecyl sulphate (SDS) or DTT + SDS as well as two-time frozen/thawed sperm (without cryoprotectant) on MPN formation and oocyte activation were examined. The non-treated sperm served as controls. The MPN formation in DTT + SDS group was higher (p<0.05) than other groups except for freeze-thaw group. No difference in the rate of activated ICSI oocytes was observed among groups. In Exp. 3, the effect of pre-treatment of sperm on subsequent development of ICSI embryos and blastocyst cell numbers were examined. The rates of cleavage and blastocyst formation as well as the blastocyst cell numbers were similar among the pre-treated and control groups. In conclusion, pre-treatment of sperm with DTT + SDS positively affected MPN formation, although the subsequent development capacity of the resulting embryos remained limited. Moreover, DTT was not effective on oocyte activation compared with Io + 6-DMAP after ICSI.

Effect of donor cell age on development of ovine nuclear transfer embryos in vitro.

The effects of the age of cell donor animal on in vitro development of ovine nuclear transfer (NT) embryos were investigated. Somatic donor cells were obtained from two different sources: (1) adult cells (adult fibroblast cells; AFC and adult cumulus cells; ACC); and (2) fetal fibroblasts (40-day-old; FFC-40 and 65-day-old; FFC-65). The fibroblast cell lines were used for NT procedures within 4-13 subpassages. While the cumulus cells were used as non-cultured (fresh) cells. The in vitro matured abattoir-derived oocytes were considered as recipients. No differences in the rates of fusion (75.7, 77.7, 76.3 and 86.7%) and cleavage (80.1, 84.3, 77.8 and 74%) were detected among couplets reconstructed with FFC-40, FFC-65, AFC and ACC, respectively. Blastocyst formation rate of those oocytes reconstructed with FFC-40 was higher (18%; p < 0.001) than those reconstructed with FFC-65 (13%) and AFC (10.9) and comparable with those reconstructed with ACC (17.5%). When the effect of passage number was analysed within groups (FFC-40, FFC-65 and AFC) there were no significant differences in fusion, cleavage and blastocyst rates between reconstructed oocytes. The present study demonstrates that the fetal and adult fibroblasts as well as fresh cumulus cells are comparable in their ability to attain cell fusion and embryonic cleavage. Moreover, the blastocyst formation rate is influenced by the age of the donor animal and the fresh cumulus cells have similar remodelling potential to that of fetal fibroblasts in term of blastocyst formation rate.

Association of educational level with risk of obesity and abdominal obesity in Iranian adults.

BACKGROUND: The impact of education on obesity may vary according to population and geographic region. The objective of the present study was to determine the association between education and obesity. METHODS: A cross-sectional study of 3600 subjects aged 20-70 years was conducted by using a cluster sampling technique in an adult population residing in the north of Iran, in 2004. Weight, height, waist and hip circumference were measured and data concerning education level, demographic characteristics and physical activities were collected by interview. Logistic regression analysis was used to estimate the association between education and general obesity (body mass index >or=30) as well as abdominal obesity (waist circumference >88 cm in women and 102 cm in men). RESULTS: The adjusted odds ratio (OR) for general obesity at education level of high school and college compared with illiterate and primary level was 0.55 [95% confidence interval (CI): 0.43-0.71]. A greater negative association was observed for education at university level (OR = 0.32, 95% CI: 0.22-0.47) irrespective to sex. However, with regard to abdominal obesity, after controlling for confounding factors, the adjusted OR for education at university level remained significant only in women but not in men. CONCLUSION: The findings of this study indicate that education level is inversely associated with general obesity in both sexes but with abdominal obesity only in women.

Vitrification of in vitro produced ovine embryos at various developmental stages using two methods.

This study was conducted to evaluate the effects of developmental stage of in vitro produced (IVP) ovine embryos and the type of vitrification procedure used on embryo cryotolerance. The IVP embryos were vitrified at five different developmental stages: 4-, 8- and 16-cell, morula, and blastocyst. For each stage, half of the embryos were vitrified in either 30 microl 3.4M glycerol+4.6M ethylene glycol in straw (method 1) or in <0.1 microl 2.7 M ethylene glycol+2.1 M Me(2)SO+0.5M sucrose placed on the inner surface of a straw (method 2) of vitrification solution, based on two different procedures. After warming embryo viability was determined by assessing the rates of re-expansion, survival, and blastocyst formation. The quality of surviving embryos was evaluated by their hatching rate and blastocyst cell numbers. In both vitrification methods, embryo survival progressively increased as the developmental stage progressed. In method 1 few of the early cleavage stage embryos (4-, 8- and 16-cell) could reach to the blastocyst stage following warming. There was no significant difference in blastocyst cell numbers (total, ICM, and trophectoderm cells) or hatching rate of blastocysts derived from vitrified embryos at different developmental stages. The number of dead cells in vitrified blastocysts in method 1 was higher than for non-vitrified blastocysts (P<0.05). The number of apoptotic cells in vitrified blastocysts was higher than for non-vitrified counterparts (P<0.05). In conclusion, both the developmental stage of IVP ovine embryos and the method of vitrification have a significant effect on the viability and developmental competence of sheep embryos.

Comparing bone mineral density in postmenopausal women with and without vertebral fracture and its value in recognizing high-risk individuals.

Vertebral fracture, the hallmark of osteoporosis, usually occurs in postmenopausal women with low bone mineral density (BMD). The aim this study was to determine which BMD parameter can best predict women at high risk of fracture. BMD values at the spine and femoral neck were compared in 34 women with vertebral fracture and 34 controls. Mean BMD (g/cm2), T-score, and Z-score values at both femoral neck and spine were significantly lower in the fracture than the nonfracture group. Z-score was more sensitive than BMD T-score for detecting low bone mass. T-score was not sensitive enough to identify low BMD in the spine, whereas the femoral neck T-score could recognize women at high risk of fracture with higher accuracy.

Effects of growth hormone on nuclear maturation of ovine oocytes and subsequent embryo development.

The objective of this study was to determine the effect of the presence of recombinant ovine growth hormone either alone or together with follicle stimulating hormone (FSH) during ovine oocyte in vitro maturation (IVM) on nuclear maturation and subsequent embryo development. Moreover, the effect of growth hormine (GH) on embryo development whether influenced by the presence of foetal bovine serum (FBS) was assessed. The abattoir-derived oocytes were randomly divided into four treatment groups and cultured in maturation medium supplemented with: (i) 0.05 IU/ml FSH; (ii) 300 ng/ml roGH; (iii) FSH + roGH; and (iv) no FSH and GH (control). The percentages of germinal vesicle-stage oocytes in GH-treated group after 8 h of culture was significantly higher than the FSH and FSH + GH groups and lower than control (22.4%, 8.7%, 9.1%, and 32% respectively). The percentage of MII-stage oocytes was significantly increased in the presence of GH after 16 and 24 h of culture compared to the control (44.7% and 83.1% vs 32.6% and 73.6% respectively). There was no significant synergism between GH and FSH in terms of nuclear maturation. The blastocyst rates in serum-supplemented groups were enhanced by the presence of FSH and GH compared to the control (35.4% and 31.3 vs 11.4% respectively). Compared with either GH or FSH alone, the subsequent embryo development (blastocyst rate), however, was negatively influenced by co-presence of both hormones (22.8%). In contrast, the corresponding values were not affected in the absence of serum. In conclusion, GH had positive effect on nuclear maturation of sheep oocytes. Moreover, the pattern of the effect of GH on embryo development was influenced by the presence of FBS during IVM.

Comparing bone mineral density in postmenopausal women with and without vertebral fracture and its value in recognizing high-risk individuals

Vertebral fracture, the hallmark of osteoporosis, usually occurs in postmenopausal women with low bone mineral density [BMD]. The aim this study was to determine which BMD parameter can best predict women at high risk of fracture. BMD values at the spine and femoral neck were compared in 34 women with vertebral fracture and 34 controls. Mean BMD [g/cm[2]], T-score, and Z-score values at both femoral neck and spine were significantly lower in the fracture than the nonfracture group. Z-score was more sensitive than BMD T-score for detecting low bone mass. T-score was not sensitive enough to identify low BMD in the spine, whereas the femoral neck T-score could recognize women at high risk of fracture with higher accuracy

Effect of culture system on survival rate of vitrified bovine embryos produced in vitro.

This study was designed to evaluate the effect of in vitro culture system on bovine blastocyst yield and quality after vitrification. In Experiment 1, IVM/IVF zygotes were allocated to three culture conditions: (I) Oviductal cells-SOF (OCM-SOF); (II) Oviductal cells-TCM (OCM-TCM); and (III) SOF for 8 days. There was no significant difference between blastocyst rates among groups. In Experiment 2, the IVP-blastocysts in three above culture conditions were vitrified within groups segregated according to age (Day 7 and 8) and blastocoelic cavity size (early and expanded blastocysts). A trend of higher survival rate was obtained in vitrified/warmed early blastocysts compared with expanded ones, so that the difference in OCM-TCM group was significant (P<0.001). Higher survival and hatching rates (P<0.001) were obtained in OCM-SOF and OCM-TCM groups (co-culture) compared with SOF group and the age of blastocyst had no effect on post-thaw survival and hatching rates. In Experiment 3, after staining of blastocysts, in fresh blastocysts the highest number of trophectoderm cells was observed in OCM-TCM group and the number of inner cell mass (ICM) was higher in co-culture groups than SOF group (P<0.001). In vitrified/warmed blastocysts the number of ICM and trophectoderm cells in co-culture groups was higher than SOF group (P<0.001) except for the ICM of expanded blastocysts. In conclusion, in our culture conditions, the blastocyst yield is not influenced by culture system, while the cryotolerance of IVP-blastocysts is positively influenced by the presence of somatic cells. Moreover, the expanded blastocysts are more susceptible to cryoinjury than early blastocysts.

In vitro developmental competence of ICSI-derived activated ovine embryos.

The present study was conducted to determine the necessity for activation after intracytoplasmic sperm injection (ICSI) in sheep. The effect of chemical stimulation with either 5microM ionomycin (I) for 5min or ionomycin+2mM 6-dimethylaminopurine (6-DMAP) for 3h on the efficiency of ICSI, was compared in six experimental groups: (1) ICSI, (2) ICSI+I, (3) ICSI+I+6DMAP, (4) Sham, (5) Sham+I, and (6) parthenogenetics (Sham and parthenogenetic groups were used as controls). In the present study, ovine oocytes needed additional chemical stimulation, after conventional ICSI, to activate (female pronucleous formation) and to form zygotes with male and female pronuclei (2PN). The percentage of cleaved embryos obtained and developed to blastocyst stage was higher (P<0.001) for ICSI-derived zygotes, followed by activation (I and I+6DMAP; 18.2 and 22.5%, respectively) than ICSI and Sham injection without activation (3.0 and 0.0%, respectively). There was, however, no significant difference between activation protocols I or I+6DMAP. Furthermore, there was no significant difference among chemically activated, ICSI-derived zygotes in term of hatchability rate; however, the percentage was significantly higher in parthenogenetic and IVF groups than ICSI and Sham injection. In conclusion, neither sperm alone nor mechanical activation was sufficient for ovine oocyte activation and pronuclei formation. Therefore, in our study conditions for in vitro embryo development, chemical activation of oocytes must be considered an essential part of the ICSI procedure in sheep.

Biomechanical comparison of the pullout properties of external skeletal fixation pins in the tibiae of intact and ovariectomised ewes.

The pin-bone interface is the least stable component of the external skeletal fixator. Concerns exist regarding the ability to obtain adequate implant purchase in poor quality bone. Consequently, reduced bone quality has been viewed as a contra-indication for the use of external skeletal fixators. The aim of this study was to investigate the holding power of two different fixator pin designs in bone from entire and ovariectomised sheep. Thirty-two aged ewes were divided into two groups. Group 1 were controls, and Group 2 were ovariectomised (OVX). The ewes were sacrificed 12 months post-ovariectomy and five pairs of tibiae were harvested from each group. The holding power of cortical and cancellous fixator pins was assessed at five standardised locations on each tibia. An increase in mean cortical thickness was noted in the OVX group. The holding power of cancellous fixator pins was superior to that of cortical pins, irrespective of whether or not ovariectomy had been performed. Cancellous pins had an increased holding power in post ovariectomy bone compared to control bone. Cortical pin performance was not affected by ovariectomy. There was a lack of correlation between the incidence of insertional fractures of the far cortex and implant holding power. The results raise questions over the effectiveness of ovariectomy in establishing osteopaenic bone suitable for assessing implant performance, hence further investigations are warranted.