Effects of oocyte quality, incubation time and maturation environment on the number of chromosomal abnormalities in IVF-derived early bovine embryos

Chromosomal aberrations are one of the major causes of embryo developmental failures in mammals. The occurrence of these types of abnormalities is higher in in vitro-produced (IVP) embryos. The aim of the present study was to investigate the effect of oocyte morphology and maturation conditions on the rate of chromosomal abnormalities in bovine preimplantational embryos. To this end, 790 early cattle embryos derived from oocytes with different morphologies and matured under different conditions, including maturation period (24 v. 36 h) and maturation media (five different serum supplements in TCM-199), were evaluated cytogenetically in three sequential experiments. The rates of normal diploidy and abnormal haploidy, polyploidy and aneuploidy were determined in each embryo. Throughout all the experiments, the rate of chromosomal abnormalities was significantly (P < 0.05) affected by oocyte morphology and maturation conditions (maturation time and culture medium). Lower morphological quality was associated with a high rate of chromosome abnormalities (P < 0.05). Moreover, polyploidy was associated with increased maturation time (P < 0.01), whereas the maturation medium significantly (P < 0.05) affected the rates of haploidy and polyploidy. In general, supplementing the maturation medium with oestrous cow serum or fetal calf serum resulted in higher rates of chromosomal aberrations (P < 0.05) compared with the other serum supplements tested (bovine steer serum, anoestroues cow serum, bovine amniotic fluid and bovine serum albumin). On the basis of the results of the present study, we conclude that the morphological quality of oocytes and the maturation conditions affect the rate of chromosomal abnormalities in IVP bovine embryos.

84 EFFECT OF A STRESSOR ON CANINE SPERM DNA FRAGMENTATION USING THE SPERM CHROMATIN DISPERSION TEST

Recently, a new procedure for the analysis of sperm DNA fragmentation has been developed for human and different mammalian species (Sperm-Halomax®), based on the sperm chromatin dispersion test (SCDt); however, no studies has been performed specifically on canine frozen–thawed-stressed semen but is there for cooled semen. The aim of this work was to assess the effect of a stressor (24 h in an oven at 38°C) on canine frozen–thawed semen using the SCDt to resemble what happens in the female reproductive tract. For this purpose, ejaculates were collected by digital manipulation from 4 healthy beagle dogs and the sperm-rich fraction of the ejaculates from 3 different dogs was pooled each time. All the pooled semen samples (n = 4) used presented physiological values concerning to routine semen parameters (motility, morphology, and sperm concentration). After evaluation, semen samples were centrifuged and the sperm pellet resuspended to a final concentration of 100 × 106 sperm mL–1 in 2 steps with CaniPRO Freeze (Minitub, Tiefenbach, Germany). Sperm were slowly cooled to 5°C and then loaded into 0.5-mL plastic straws. After that, straws were frozen in liquid-nitrogen vapours for 10 min and stored into a nitrogen tank. Straws were thawed in a water bath (30 s/37°C) and incubated for 24 hours at 38°C before analysis. The sperm DNA fragmentation was assessed in fresh semen and frozen–thawed-stressed samples using the Sperm-Halomax® commercial kit specifically developed for canine semen (Halotech DNA SL, Madrid, Spain) following the manufacturer’s instructions. Slides were stained for green fluorescence staining and 500 sperm per slide were counted using fluorescence microscopy. The sperm DNA fragmentation index (%) was compared between fresh and frozen–thawed-stressed semen samples by ANOVA. Results were expressed as mean ± standard error of the mean. The results obtained showed that subjecting thawed semen to 24 h in an oven at 38°C significantly increased (P < 0.05) DNA fragmentation compared with fresh semen (2.7% ± 0.2 v. 1.4 ± 0.1%). The stress factor was performed to simulate the viability of canine thawed sperm (12–24 h) when a bitch is inseminated with frozen semen. It would be interesting to perform further studies to relate sperm DNA fragmentation and fertility of frozen–thawed canine semen. In conclusion, frozen–thawed-stressed semen samples increased the sperm DNA fragmentation index measured using a SCDt. Further studies are needed to relate sperm DNA fragmentation with fertility rates or cryopreservation success.

237 CHROMOSOMAL ABNORMALITIES IN IN VITRO-PRODUCED EARLY BOVINE EMBRYOS: USE OF HOMOLOGOUS FOLLICULAR FLUID SUPPLEMENTATION IN THE OOCYTE MATURATION MEDIA

Chromosomal abnormalities were described as a possible cause of embryo failures in cattle, even more so when they are in vitro produced. It has been widely demonstrated that the post-fertilization culture environment affects the frequency of blastomeric aneuploidies. However, the literature concerning the effect of the oocyte maturation techniques on in vitro-produced embryos is scarce. The aim of this study was to determine the effect of homologous bovine follicular fluid (BFF) as a possible replacement for commercial sera in the appearance of chromosomal abnormalities on early IVF-produced embryos. Cumulus–oocyte complexes obtained from ovarian puncture were maturated in modified bicarbonate-buffered TCM-199 media, supplemented with glutamine, sodium pyruvate, FSH, LH, oestradiol, and gentamicin in three different groups. Two treatments were performed: 1) base media supplemented with BFF, obtained aseptically from follicles between 4 and 10 mm in diameter (10 and 20%), and 2) a control group, with base media supplemented with 10% FCS without BFF. After 20 h of culture at 38.5°C in a 5% CO2 humid atmosphere, cumulus–oocyte complexes from both treatments were fertilized in IVF media and then cultured for 72 h in SOF media, according to our laboratory techniques. A total of 152 early embryos were cytogenetically evaluated following our standard laboratory techniques. Developed embryos were individually fixed onto a slide, disaggregated into blastomeres with acetic acid, and stained with Giemsa solution. Chromosomal numerical abnormalities were evaluated in each embryo by direct observation at 1250× magnification using a bright field microscope. Results were statistically compared among treatments by the expected proportion test. No significant differences (P > 0.05) were found between different culture media on the percentages of normal diploid embryos or each kind of numerical abnormality. According to our results (Table 1), the use of homologous follicular fluid as a supplement on the oocyte maturation media did not influence the appearance of abnormal complements in the embryos produced compared with the use of FCS. In conclusion, homologous follicular fluid may be considered a valid serum replacement in the maturation media on IVF-produced bovine embryos. Table 1.Analysis of chromosomal complements of Day 3 in vitro-produced bovine embryos derived from oocytes maturated in culture media with different serum supplementation1

72 EFFECT OF SINGLE-LAYER CENTRIFUGATION WITH EQUIPURE™ ON MOTILITY KINEMATICS OF FROZEN - THAWED DONKEY SPERM

Single-layer centrifugation (SLC) with EquipureTM Bottom Layer has been used to enhance the quality of stallion semen samples; however, no studies have been performed on donkeys. The aim of this study was to determine if SLC with EquipureTM Bottom Layer improves kinematic parameters on frozen–thawed donkey sperm. Semen was collected from 4 Andalusian donkeys by artificial vagina. Three ejaculates from each donkey were centrifuged with EquiproTM, supernatant was removed, and pellet was re-extended in the freezing medium GentTM to a final concentration of 200 × 106 spermatozoa per milliliter. Sperm were slowly cooled to 5°C for 2 h, loaded in 0.5-mL plastic straws, and frozen in liquid-nitrogen vapors. After at least one week of storage, straws were thawed in a water bath at 37°C for 30 s. After thawing, semen samples were divided in 2 aliquots: aliquot 1 was used as such (control) and aliquot 2 was processed by SLC using EquipureTM Bottom Layer. Computer-assisted sperm analysis was performed, and sperm kinematics total motility (%), progressive motility (%), curvilinear velocity (VCL; µm s–1), velocity straight line (VSL; µm s–1), velocity average path (VAP; µm s–1), linearity (LIN; %), straightness (STR; %), wobble (WOB; %), lateral head displacement (ALH; µm), and beat cross frequency (BCF; Hz) were statistically compared using GLM model between frozen–thawed semen samples processed or not with EquipureTM. Results were expressed as mean ± standard error. Significant differences (P < 0.05) were found between SLC-selected and unselected semen for total motility (77.44 ± 5.83 v. 58.89 ± 6.07), progressive motility (76.88 ± 4.52 v. 56.59 ± 5.44), VCL (137.50 ± 0.75 v. 133.0 ± 0.99), LIN (69.43 ± 0.31 v. 68.23 ± 0.41), STR (78.45 ± 0.29 v. 76.90 ± 0.37), WOB (85.06 ± 0.18 v. 83.91 ± 0.26), ALH (2.76 ± 0.01 v. 2.44 ± 0.01), and BCF (9.13 ± 0.05 v. 8.53 ± 0.06), respectively. No significant differences were observed for VSL (102.89 ± 0.70 v. 104.32 ± 0.95) and VAP (123.21 ± 0.71 v. 121.50 ± 0.98). Most of the computer-assisted sperm analysis parameters used in the present study have been previously identified as reliable markers of sperm motility in relation to sperm quality and fertility. It has also been reported that VCL appears to be critical for the formation of the sperm reservoir and penetration of the zona pellucida. In addition, other variables improved in the SLC-selected samples have been described as measure of progressivity (LIN, STR) and spermatozoa vigor (BCF, ALH). These preliminary results suggest an additional option for improving sperm quality in donkey semen doses. In conclusion, SLC with EquipureTM can be used to enhance kinematic parameters on frozen–thawed donkey sperm.

Erratum to: 56 SINGLE LAYER CENTRIFUGATION THROUGH PURESPERM® 80 IMPROVES QUALITY OF CRYOPRESERVED DOG SPERMATOZOA

Density gradient centrifugation with PureSperm® (PureSperm® 40+PureSperm® 80; Nidacon International, Mölndal, Sweden) has been satisfactorily used to enhance the quality of dog semen samples; however, no studies have been performed on the effect of single layer centrifugation (SLC) with PureSperm® on frozen–thawed dog semen. The aim of this study was to investigate if SLC with PureSperm® 80 can improve the post-thaw semen quality of dog. Semen from 5 dogs was collected by digital manipulation. Two ejaculates from each dog were centrifuged with Tris-based extender, supernatant was removed, and sperm pellet was suspended to a final concentration of 300–400×106spermmL–1 with CaniPROTM Freeze A plus 20% egg yolk at 22°C. Extended semen was cooled to 5°C within an hour and then diluted to a final concentration of 150–200×106spermmL–1 in CaniPROTM Freeze B plus 20% egg yolk at 5°C, loaded in 0.5-mL plastic straws and frozen horizontally in ranks placed 4cm above the surface of liquid nitrogen vapors for 10min, after which they were directly placed in liquid nitrogen. After 24 to 48h of storage, straws were thawed in a water bath at 37°C for 30s. After thawing, semen samples were divided in 2 aliquots: one of them was used as control and the other one was processed by SLC PureSperm® 80. Assessment of sperm motility (assessed by computerized-assisted semen analysis), morphology (Diff-Quick staining), and viability [triple fluorescent stain of propidium iodine/isothiocyanate-labeled peanut (Arachis hypogaea) agglutinin/Rhodamine 123] were evaluated in control and treated semen samples. Data were studied by ANOVA. Results are expressed as mean ± SEM. Significant (P&lt;0.001) differences were found between SLC-treated and control semen for sperm motility (percentage of total motile spermatozoa: 93.65±0.05 v. 83.79±0.13; percentage of progressive motile spermatozoa: 79.38±6.66 v. 54.61±16.11), morphology (86.45±0.01 v. 83.51±0.01), and viability (percentage of viable sperm with an intact acrosome: 58.32±0.04 v. 36.50±0.17; percentage of viable sperm with an acrosome reaction: 2.81±0.01 v. 9.74±0.21). Based on our results, we can conclude that SLC with PureSperm® 80 is an alternative and successful method for improving the quality of frozen–thawed dog spermatozoa, selecting good-quality spermatozoa (motile, morphologically normal, viable, and acrosome intact spermatozoa) from the rest of the semen sample.

14 FREEZING OF DONKEY SEMEN AFTER 24 HOURS OF COOL STORAGE: PRELIMINARY RESULTS

Several studies on sperm cooling and cryopreservation have been done in horses; however, only a few them have been developed in donkeys. In addition, no studies have been performed to freeze cooled stored donkey semen. Therefore, the aim of this study was to determine if it is possible to freeze donkey sperm after 24 h of cool storage. Semen was collected from 4 Andalusian donkeys by artificial vagina. After collection, each sample was separated into 2 aliquots; one of them was immediately frozen (t0) and the other one was cooled and stored before freezing (t24). The cryopreservation procedure consisted of a previous dilution of semen with EquiPro™. After that, semen was centrifuged and the sperm pellet resuspended with Gent® extender plus ethylene glycol (4%) to achieve a final concentration of 100 × 106 sperm mL–1. Sperm was slowly cooled to 5°C, loaded in 0.5-mL plastic straws and frozen in LN vapours. The second aliquot (t24) was diluted with Gent® extender to a final concentration of 50 × 106 sperm mL–1 and then cooled and stored at 5°C for 24 h. After that, cooled semen samples were cryopreserved following the same procedure as described above. Straws were thawed in a water bath at 37° for 30 s. Computer-assisted sperm motility analysis was performed. Total motility (TM), progressive motility (PM), and the following kinematic parameters: velocity curvilinear (VCL; µm s–1), velocity straight line (VSL; µm s–1), velocity average path (VAP; µm s–1), linearity (LIN; %), straightness (STR; %), wobble (WOB; %), amplitude of lateral head displacement (ALH; µm), and beat cross frequency (BCF; Hz) were compared between treatments by ANOVA. Results were expressed as mean ± standard error. Significant differences (P < 0.05) were found between treatments (t0 v. t24) for TM (63.76 ± 4.75 v. 51.67 ± 3.69), PM (36.01 ± 3.19 v. 27.24 ± 2.72), VCL (77.29 ± 0.65 v. 67.56 ± 0.78), VSL (58.50 ± 0.61 v. 52.11 ± 0.76), VAP (67.82 ± 0.64 v. 59.41 ± 0.79), LIN (57.90 ± 0.33 v. 59.53 ± 0.32), STR (70.39 ± 0.30 v. 72.43 ± 0.41), WOB (75.64 ± 0.22 v. 75.48 ± 0.32), ALH (1.88 ± 0.09 v. 1.69 ± 0.10), and BCF (6.28 ± 0.04 v. 6.51 ± 0.06). These preliminary results showed significant differences between cryopreservation at 0 and 24 h post-cooling; however, understanding that direct freezing is better in terms of sperm motility, cryopreservation of cooled stored semen could still be considered good according to the values obtained for sperm motility parameters after thawing. In our opinion, sperm centrifugation before cooling probably improve the results of cryopreservation 24 h post-cooling, due to the negative effect of seminal plasma on sperm viability during storage. In addition, the analysis of other sperm parameters would be useful to check more accurately differences between treatments. In conclusion, sperm motility parameters were higher in donkey semen samples immediately frozen after collection in comparison to semen samples cryopreserved after 24 h of cooling storage. Further studies are needed to improve cooling and cryopreservation procedures for freezing cooled stored donkey semen.

Erratum to: 56 SINGLE LAYER CENTRIFUGATION THROUGH PURESPERM® 80 IMPROVES QUALITY OF CRYOPRESERVED DOG SPERMATOZOA

Density gradient centrifugation with PureSperm® (PureSperm® 40 + PureSperm® 80; Nidacon International, Mölndal, Sweden) has been satisfactorily used to enhance the quality of dog semen samples; however, no studies have been performed on the effect of single layer centrifugation (SLC) with PureSperm® on frozen–thawed dog semen. The aim of this study was to investigate if SLC with PureSperm® 80 can improve the post-thaw semen quality of dog. Semen from 5 dogs was collected by digital manipulation. Two ejaculates from each dog were centrifuged with Tris-based extender, supernatant was removed, and sperm pellet was suspended to a final concentration of 300–400 × 106 sperm mL–1 with CaniPROTM Freeze A plus 20% egg yolk at 22°C. Extended semen was cooled to 5°C within an hour and then diluted to a final concentration of 150–200 × 106 sperm mL–1 in CaniPROTM Freeze B plus 20% egg yolk at 5°C, loaded in 0.5-mL plastic straws and frozen horizontally in ranks placed 4 cm above the surface of liquid nitrogen vapors for 10 min, after which they were directly placed in liquid nitrogen. After 24 to 48 h of storage, straws were thawed in a water bath at 37°C for 30 s. After thawing, semen samples were divided in 2 aliquots: one of them was used as control and the other one was processed by SLC PureSperm® 80. Assessment of sperm motility (assessed by computerized-assisted semen analysis), morphology (Diff-Quick staining), and viability [triple fluorescent stain of propidium iodine/isothiocyanate-labeled peanut (Arachis hypogaea) agglutinin/Rhodamine 123] were evaluated in control and treated semen samples. Data were studied by ANOVA. Results are expressed as mean ± SEM. Significant (P < 0.001) differences were found between SLC-treated and control semen for sperm motility (percentage of total motile spermatozoa: 93.65 ± 0.05 v. 83.79 ± 0.13; percentage of progressive motile spermatozoa: 79.38 ± 6.66 v. 54.61 ± 16.11), morphology (86.45 ± 0.01 v. 83.51 ± 0.01), and viability (percentage of viable sperm with an intact acrosome: 58.32 ± 0.04 v. 36.50 ± 0.17; percentage of viable sperm with an acrosome reaction: 2.81 ± 0.01 v. 9.74 ± 0.21). Based on our results, we can conclude that SLC with PureSperm® 80 is an alternative and successful method for improving the quality of frozen–thawed dog spermatozoa, selecting good-quality spermatozoa (motile, morphologically normal, viable, and acrosome intact spermatozoa) from the rest of the semen sample.

Data Integration in Genomic Medicine: Trends and Applications

In a near future, each person will incorporate his/her own sequenced genome in his/her electronic health record. In that precise moment, genomic medicine will be fundamental for clinical practice, as an essential key of personalized medicine. All the genomic data, as well as other ‘omics’ and clinical data necessary for personalized medicine, are stored in several distributed databases. Research and patient care require each time more biomedical data integration of several distributed heterogeneous datasources.

This work develops a comprehensive review of the most relevant works in biomedical data integration, specifically in genomic medical data, analyzing the evolution of architecture and integration techniques during the last 20 years, and its usage.

Most of these solutions, based on cross-linking, data warehouse or federated approaches, are suitable for specific domains. However, none of the models found in the literature is completely appropriate for a general biomedical data integration problem.

Follicular dynamics, interval to ovulation and fertility after AI in short-term progesterone and PGF2α oestrous synchronization protocol in sheep

The study was aimed to assess the influence that short-term progesterone treatments have on follicular dynamics, oestrus and ovulation in sheep. The treatment was tested thereafter in a field trial to assess its fertility after AI with fresh semen. In a first experiment, 12 ewes without CL were grouped to receive a new (n = 6) or used CIDR (n = 6) for 7 days and blood samples were obtained to follow plasma progesterone profiles. In a second experiment, 39 cycling ewes were synchronized by a 7-day P4+PGF2α protocol using a new (n = 20) or a 7-day used CIDR (n = 19). Half of both groups received 400 IU eCG and half remained untreated as controls. Ultrasound ovarian examination and oestrous detection were used to compare follicular dynamics, oestrus and ovulation in both groups. In a third experiment, 288 ewes in 3 farms were synchronized by the short-term P4+PGF2α+eCG protocol and ewes were AI with fresh semen 24 h after oestrous detection. Lambing performance was used to test the fertility of the treatment. In Experiment 1, ewes with new inserts presented higher P4 concentration than ewes with used inserts throughout the sampling period (p < 0.05) and exhibited a P4 peak at days 1-2 of the treatment that was not observed in ewes with used inserts. In Experiment 2, ewes treated with new and used inserts show similar ovarian and behavioral traits (p > 0.10). However, ewes treated with eCG show shorter interval to oestrus (p = 0.004) and tend to have larger mature CL (p = 0.06). In Experiment 3, oestrous presentation and lambing performance after AI with fresh semen was considered normal compared to published results. Results suggest that the oestrous synchronization protocol based on P4+PGF2α allows little control of follicular dynamics without compromising fertility after AI with fresh semen provided that eCG is added at the end of the treatment.

Data Integration in Genomic Medicine: Trends and Applications. Contribution of the IMIA Working Group on Informatics in Genomic Medicine

OBJECTIVES

In a near future, each person will incorporate his/her own sequenced genome in his/her electronic health record. In that precise moment, genomic medicine will be fundamental for clinical practice, as an essential key of personalized medicine. All the genomic data, as well as other 'omics' and clinical data necessary for personalized medicine, are stored in several distributed databases. Research and patient care require each time more biomedical data integration of several distributed heterogeneous datasources.

METHODS

This work develops a comprehensive review of the most relevant works in biomedical data integration, specifically in genomic medical data, analyzing the evolution of architecture and integration techniques during the last 20 years, and its usage.

CONCLUSION

Most of these solutions, based on cross-linking, data warehouse or federated approaches, are suitable for specific domains. However, none of the models found in the literature is completely appropriate for a general biomedical data integration problem.

313 ASSESSMENT OF SPERM DNA FRAGMENTATION IN CANINE EJACULATES USING THE Sperm-Halomax® KIT: PRELIMINARY RESULTS

Recently, a new procedure for the analysis of sperm DNA fragmentation has been developed for humans and different mammalian species, using a commercial kit based on the sperm chromatin dispersion (SCD) test; however, a descriptive study in canine semen has not been performed. The aim of this work was to assess the sperm DNA fragmentation in canine ejaculates using the SCD test and 2 different staining techniques. For this purpose, ejaculates were collectedby digital manipulation from4 healthy dogs of different breeds (1 German Pointer, 2 Spanish Greyhounds, and 1 Crossbreed). After collection, the sperm-rich fraction of the ejaculates from 3 dogs were pooled each time (n = 4) and then extended in Dulbecco’s phosphate buffered saline. All the pooled semen samples presented physiological values concerning routine semen parameters (motility, morphology, and sperm concentration). The sperm DNA fragmentation was assessed using the Sperm-Halomax® commercial kit specifically developed for canine semen (Halotech DNA SL, Madrid, Spain). Two semen aliquots of the diluted pooled semen samples were processed on each pre-treated slide provided in the kit following the manufacturer’s instructions. The last step was the staining technique. We stained each slide with 2 different staining procedures. The first half of the slide was stained with propidium iodide (Sigma-Aldrich, St. Louis, MO, USA) mixed in a proportion 1 : 1 with an antifading solution. The second half of the slide was stained for 15 min in Wright solution (1.01383.0500, Merck, Whitehouse Station, NJ, USA) 1 :1 in Phosphate Buffer pH 6.88 (1.07294.1000, Merck). The stained slides were observed using fluorescence and light microscopy, respectively. Five hundred sperm per slide were counted. Spermatozoa with fragmented DNA showed a large and spotty halo of chromatin dispersion. Unfragmented sperm only showed a small and compact halo. Statistical analyses were performed using the Statistical Package for Social Science version 12.0 (SPSS Inc., Chicago, IL, USA). The sperm DNA fragmentation index was compared between Wright and fluorescence staining methods by ANOVA. Results were expressed as mean ± standard error of the mean. The first report of the sperm DNA fragmentation index in canine ejaculates was 2.26 ± 0.53% for Wright staining and 1.99 ± 0.10% for fluorescence technique. No differences were found between staining procedures. In conclusion, it was possible to assess the sperm DNA fragmentation of canine ejaculates using 2 different staining procedures, expecting that continuous research could be useful in defining the role of DNA fragmentation SCD test in canine semen evaluation and cryopreservation.

90 EFFECT OF EGG YOLK ON THE KINEMATICS AND ACROSOME MEMBRANE INTEGRITY OF COOLED-REWARMED CANINE SPERMATOZOA

Tris-egg yolk-based diluents provide adequate cryoprotection for the sperm of most species. This study was conducted to compare the ability of Tris-glucose extender containing 2 different concentrations of egg yolk to maintain sperm motility and acrosome integrity of canine spermatozoa during 72 h of preservation. For this purpose, a total of 20 ejaculates from 4 clinically healthy dogs (2 Spanish Greyhound, 1 German Pointer, and 1 Crossbreed) were collected by digital manipulation. The sperm-rich fraction of each ejaculate was divided into 2 aliquots. Then, they were diluted in Tris-based extender and centrifuged at 700g for 8 min. Sperm pellets were resuspended in either Tris buffer added to 20% (EY20) or 10% centrifuged egg yolk (EY10) and cooled to 5°C over 72 h. The effects of these extenders on motility and acrosome integrity were assessed objectively using a computer-aided semen analyzer (Sperm Class Analyzer, Microptic SL, Spain) and Spermac® staining, respectively. Each cooled-rewarmed semen sample was evaluated after 24, 48, and 72 h of preservation. Sperm motion parameters shown by computer-assisted semen analysis (CASA) are progressively motile (PMS) and motile spermatozoa (MS), curvilinear velocity (CLV), average path velocity (APV), progressive speed (SLV), and lateral head displacement (LHD). Data were statistically analysed by ANOVA. Dependent variables expressed as percentages were arsine-transformed before analysis. Differences between mean values were evaluated by the Duncan method. Data were presented as mean ± SEM. Differences were considered significant when P < 0.05. Analyses were performed using the statistical package SPSS 12.0. A total of 98 172 motile sperm trajectories were analyzed by CASA: 52 259 in EY20 and 45 913 in EY10. After 24, 48, and 72 h of preservation, MS and PMS were statistically higher (P < 0.01) in EY20. No significant differences were found for LHD using either extender over a 72-h period. No significant differences were observed for CLV using either extender during the first 2 days. At Day 3, CLV data were significantly higher (P < 0.01) in EY20. Similarly, from Day 2, APV was significantly higher (P < 0.001) in EY20. After 24 h of preservation, SLV was statistically higher (P < 0.001) in EY10, whereas the opposite tendency was found at Day 3. No significant differences were observed for SLV using either extender after 48 h of preservation. During the first 2 days, acrosome integrity was statistically higher (P < 0.001) in EY20. At hour 72, higher acrosome integrity (P < 0.001) was observed in EY10. In conclusion, we have observed that the EY20 extender provided higher motility after 72 h of chilled preservation; however, the acrosome membrane integrity was better preserved in EY10.

Cancer stem cells and brain tumors

Besides the role of normal stem cells in organogenesis, cancer stem cells are thought to be crucial for tumorigenesis. Most current research on human tumors is focused on molecular and cellular analysis of the bulk tumor mass. However, evidence in leukemia and, more recently, in solid tumors suggests that the tumor cell population is heterogeneous. In recent years, several groups have described the existence of a cancer stem cell population in different brain tumors. These neural cancer stem cells (NCSC) can be isolated by cell sorting of dissociated suspensions of tumor cells for the neural stem cell marker CD133. These CD133+ cells -which also express nestin, an intermediate filament that is another neural stem cell marker- represent a small fraction of the entire brain tumor population. The stem-like cancer cells appear to be solely responsible for propagating the disease in laboratory models. A promising new approach to treating glioblastoma proposes targeting cancer stem cells. Here, we summarize progress in delineating NCSC and the implications of the discovery of this cell population in human brain tumors.

Chemically driven variable selection by focused multimodal genetic algorithms in mid-IR spectra

Four genetic-algorithm-based approaches to variable selection in spectral data sets are presented. They range from a pure black-box approach to a chemically driven one. The latter uses a fitness function that takes into account not only typical parameters like the number of errors when classifying a training set but also the chemical interpretability of the selected variables. In order to cope with the fact that multiple solutions may be acceptable, a multimodal genetic algorithm (GA) is employed and the most satisfactory solution selected. The multimodal GA uses two populations (denominated "hybrid two populations" GA or HTP-GA): a classical population, from which potential solutions emerge, and a new population, which maintains diversity in the search space (as required by multimodal problems). Results show that the HTP-GA approach improves the chemical understanding of the selected solution (compared to other GA approaches) and that the classification capabilities of the approach are still good. All of the GA strategies for variable selection were compared with a classical parametric technique, Procrustes rotation, which does not consider interpretability.

Cryopreservation of goat spermatozoa: Comparison of two freezing extenders based on post-thaw sperm quality and fertility rates after artificial insemination

TRIS-glucose or skim milk extenders are most commonly used for cryopreserving goat sperm. The aim of this study was to compare the ability of two extenders based on TRIS and skimmed milk buffer to maintain sperm viability after cryopreservation. Goat semen samples (n=110) were frozen with TRIS and with milk extender and thaw. Sperm motion parameters, morphology and acrosomal integrity were assessed in fresh and frozen-thawed samples by Sperm Class Analyzer (SCA) and Diff-Quik and Spermac staining techniques. Pregnancy rates were obtained after cervical insemination with frozen semen doses. The cryopreservation process had a significant effect on acrosome and kinematic parameters. TRIS extender provided more effective preservation of total motility, velocity parameters and amplitude of lateral head displacement after freezing. The percentage of acrosome intact spermatozoa was significantly higher in samples diluted with milk extender. In the insemination doses, mean values of velocity parameters and lateral head displacement were higher in doses processed in TRIS. Spermatozoa frozen in milk extender was mathematically greater than for those frozen with TRIS extenders, though no significant difference exists. We conclude that post-thaw kinematic parameters and acrosome integrity assessed after 1h of incubation was acceptable in both extenders which indicated the feasibility of cryopreserving goat spermatozoa. TRIS extender results in better in vitro performance compared to milk, though these improvements were not reflected in fertility results. Semen doses cryopreserved in milk extender provided greater pregnancy rates after intra-cervical insemination compared to those in TRIS extender (52.4% versus 42.9%).

Nitrogen-removal with protease as a method to improve the selective delignification of hemp stemwood by the white-rot fungus Bjerkandera sp. strain BOS55

Certain white-rot fungi cause selective removal of lignin from woody substrates. Selective delignification can potentially be applied to biopulping and upgrading animal feeds. Nitrogen nutrient limitation is known to enhance the selectivity of lignin degradation. The relatively high N-content of annual fiber crops is an important drawback for utilizing white-rot fungi for their selective delignification. In this study, removal of N from hemp stemwood with protease was explored as a means of improving the selectivity of lignin degradation by the white-rot fungus Bjerkandera sp. strain BOS55. Various protease treatments followed by hot-water extraction were found to be suitable in lowering the N-content of hemp stemwood by up to 70%. The removal was significantly higher than with hot-water extraction alone, which caused a 39% N-removal. The selectivity of lignin degradation was compared in protease-treated, hot-water treated, untreated and ammonium-spiked hemp stemwood, providing N levels that were, respectively, 0.32-, 0.61-, 1.0- and 5.0-fold relative to the natural N-content in the substrate. Removal of N by hot-water extraction alone or in combination with protease greatly protected the holocellulose fraction from excessive decay during 10 weeks of solid state fermentation. However, the selectivity of lignin decay was only greatly enhanced (three-fold) by the protease treatment, due mostly to a highly improved lignin degradation at the lowest N-level.

Infrared spectroscopy analysis of hemp (Cannabis sativa) after selective delignification by Bjerkandera sp. at different nitrogen levels

Fourier-transform infrared (FT-IR) spectroscopy has been used to monitor changes in C/N-modified lignocellulosic substrates from Cannabis sativa L. in a 7-week solid-state fermentation with the white-rot fungus Bjerkandera sp. strain BOS55. The microbial transformation of hemp was considered as a pretreatment to pulping processes in paper industries. Special emphasis was paid on the N-content of the substrate, which was modified by: (i) external ammonium inputs, (ii) water extraction, and (iii) protease treatment.Selective delignification in the N-limited media was observed. The most diagnostic FT-IR spectral bands in relation to changes in the lignocellulosic substrate were those corresponding to alkyl structures (2920, 1460 cm(-1)), carboxyl groups (1720 cm(-1)), amides (1650, 1540 cm(-1)) and carbohydrate (mainly 1030 cm(-1)). Simple and multiple regression functions revealed the potential of FT-IR in accurately reflecting substrate composition features previously determined by wet chemical methods. Correspondence analysis suggests C/N-dependent degradation patterns, and discriminant analysis confirmed that the differences between N-limited, N-enriched and the original substrate were significant (P < 0.05) in terms of the intensities of five FT-IR diagnostic bands (1030, 1130, 1270, 1540 and 1650 cm(-1)).The results suggest that, in the system studied, the FT-IR spectroscopy is a reliable alternative to wet chemical analyses in the routine monitoring of the success of the biologic process since it reflects both qualitative and quantitative changes and it is very sensitive to lignin alteration and to carbohydrate and protein concentration.

Cloning of a human cDNA encoding a novel enzyme involved in the elongation of long-chain polyunsaturated fatty acids

The Saccharomyces cerevisiae protein ELO2p is involved in the elongation of saturated and monounsaturated fatty acids. Among several sequences with limited identity with the S. cerevisiae ELO2 gene, a consensus cDNA sequence was identified from the LifeSeq(R) database of Incyte Pharmaceuticals, Inc. Human liver cDNA was amplified by PCR using oligonucleotides complementary to the 5' and 3' ends of the putative human cDNA sequence. The resulting full-length sequence, termed HELO1, consisted of 897 bp, which encoded 299 amino acids. However, in contrast with the ELO2 gene, expression of this open reading frame in S. cerevisiae demonstrated that the encoded protein was involved in the elongation of long-chain polyunsaturated fatty acids, as determined by the conversion of gamma-linolenic acid (C(18:3, n-6)) into dihomo-gamma-linolenic acid (C(20:3, n-6)), arachidonic acid (C(20:4, n-6)) into adrenic acid (C(22:4, n-6)), stearidonic acid (C(18:4, n-3)) into eicosatetraenoic acid (C(20:4, n-3)), eicosapentaenoic acid (C(20:5, n-3)) into omega3-docosapentaenoic acid (C(22:5, n-3)) and alpha-linolenic acid (C(18:3, n-3)) into omega3-eicosatrienoic acid (C(20:3, n-3)). The predicted amino acid sequence of the open reading frame had only 29% identity with the yeast ELO2 sequence, contained a single histidine-rich domain and had six transmembrane-spanning regions, as suggested by hydropathy analysis. The tissue expression profile revealed that the HELO1 gene is highly expressed in the adrenal gland and testis. Furthermore, the HELO1 gene is located on chromosome 6, best known for encoding the major histocompatibility complex, which is essential to the human immune response.

Elimination and detoxification of softwood extractives by white-rot fungi

The ability of several white-rot fungal strains to remove and detoxify acetone extractives (pitch or resin) in Scots pine sapwood was investigated in stationary laboratory batch assays. Fungal pretreatment provided up to 62% total pitch reduction and significant decreases in pitch toxicity. The best strains were Bjerkandera sp. strain Stereum hirsutum and Trametes versicolor that eliminated over 93% of the problematic triglyceride fraction and 58-87% of other lipophilic extractive classes in only 2 weeks. Fungal removal of the wood extractives was accompanied by a 7.4-16.9-fold decrease in their inhibitory effect, as determined in the Microtox bioassay. Wood pretreatment by Bjerkandera sp. and T. versicolor caused limited losses of woody mass (less than 4% in 4 weeks); whereas S. hirsutum led to somewhat higher mass losses (7% in 4 weeks). These results indicate the potential of white rot fungi to control pitch deposition problems in pulping and to reduce the aquatic toxicity caused by naturally-occurring lipophilic extractives in forest industry effluents.