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Estimation of genetic parameters of semen characteristics and reproductive traits in AI boars.

(Co)variance components and further genetic parameters of boar semen characteristics and reproductive traits were estimated using the REML procedure applied to multi-trait animal models. The calculations were based on data from 210,733 ejaculates stemming from 2862 AI boars and collected from 1990 to 1997 in insemination stations for boars in the Czech Republic. Equal model equations for all traits included the AI station and the breed or breed combination as fixed effects, the interval between two collections for the boar as covariable and the animal and residual effects as random effects. The following heritabilities were estimated: semen volume 0.58, sperm concentration 0.49, progressive motion of spermatozoa 0.38, abnormal spermatozoa 0.34, number of total spermatozoa 0.42, number of insemination doses 0.40, number of piglets born alive 0.08, total number of piglets born 0.05 and conception rate 0.29. Heritabilities and genetic correlations were estimated on average values for each boar.

Animals↗

A CIDR-based timed AI protocol can be effectively used for dairy cows with follicular cysts.

The present study evaluated whether a controlled internal drug release (CIDR)-based timed AI (TAI) protocol could be used as an efficient tool for the treatment of ovarian follicular cysts in lactating dairy cows. In the first experiment, lactating dairy cows diagnosed with follicular cysts were randomly assigned to two treatments: (1) a single injection of GnRH at diagnosis (Day 0) and AI at estrus (AIE) within 21 days (GnRH group, n=70), or (2) insertion of a CIDR device containing progesterone and an injection of GnRH on Day 0, PGF(2alpha) injection at the time of CIDR removal on Day 7, GnRH injection on Day 9, and TAI 16h after the GnRH injection (CIDR-based TAI group, n=65). Conception rate after the CIDR-based TAI protocol (52.3%) was greater (P<0.05) than that after AIE following a single GnRH injection (26.9%). In the second experiment, lactating dairy cows diagnosed with follicular cysts (Cyst group, n=16) and cows having normal estrous cycles (CYC group, n=15) received the same treatment: a CIDR device containing progesterone and an injection of GnRH on Day 0, PGF(2alpha) injection at the time of CIDR removal on Day 7, and GnRH injection on Day 9. The proportion of cows with follicular wave emergence and the interval from treatment to follicular wave emergence did not differ (P>0.05) between groups. The mean diameters of dominant follicles on Days 4 and 7 as well as preovulatory follicles on Day 9, and the synchrony of ovulation following the second injection of GnRH did not differ (P>0.05) between groups. These data suggest that the CIDR-based TAI protocol results in an acceptable conception rate in dairy cows with follicular cysts.

Animals↗

Dissecting phenotypic variation among AIS patients.

We have created genital skin fibroblast cell lines directly from three patients in a Chinese family affected by androgen insensitivity syndrome (AIS). All patients in the family share an identical AR Arg840Cys mutant but show different disease phenotypes. By using the cell lines, we find that the mutation has not influenced a normal androgen-binding capacity at 37 degrees C but has reduced the affinity for androgens and may cause thermolability of the androgen-receptor complex. The impaired nuclear trafficking of the androgen receptor in the cell lines is highly correlated with the severity of donors' disease phenotype. The transactivity of the mutant is substantially weakened and the extent of the reduced transactivity reflects severity of the donors' disease symptom. Our data reveal that although etiology of AIS is monogenic and the mutant may alter the major biological functions of its wild allele, the function of the mutant AR can also be influenced by the different genetic backgrounds and thus explains the divergent disease phenotypes.

Adult↗

scBaseCount: An AI agent-curated, standardized, auto-updated single-cell data repository.

Single-cell RNA sequencing has transformed cell biology by enabling precise transcriptomic measurements of individual cells. The Sequence Read Archive (SRA) is the largest public repository of sequencing reads, yet much of it remains underutilized due to unstandardized metadata. Here, we introduce scBaseCount, a database that leverages an AI agent to automate discovery and metadata extraction and standardize data processing. Built by mining all 10x Genomics datasets, scBaseCount is the largest public repository of single-cell gene expression data, comprising over 502 million cells across 27 organisms and 75 tissues. It offers an unbiased view of the data landscape within the SRA and enables the training of more performant computational models through access to broader phenotypic diversity. Uniform processing enables measurement of both intronic and exonic reads and non-coding gene expression and improves alignment across experiments. Moreover, scBaseCount provides a blueprint for how AI can be leveraged to autonomously curate biological data repositories.

Single-Cell Analysis↗

AIS 2005: a contemporary injury scale.

To determine and to quantify outcome from injury demands that multiple factors be universally applied so that there is uniform understanding that the same outcome is understood for the same injury. It is thus important to define the variables used in any outcome assessment. Critical to defining outcomes is the need for a universal language that defines individual injuries. The abbreviated injury scale (AIS) is the only dictionary specifically designed as a system to define the severity of injuries throughout the body. In addition to a universal injury language, it provides measures of injury severity that can be used to stratify and classify injury severity in all body regions. Its revision, AIS 2005 will be discussed here.

Abbreviated Injury Scale↗

Cyclooxygenase inhibition is associated with downregulation of apolipoprotein AI promoter activity in cultured hepatoma cell line HepG2.

Prostanoids have been implicated in the transcriptional control of several genes. Since prostanoid synthesis inhibitors are commonly used in subjects with coronary heart disease we studied the effect of cyclooxygenase (COX) inhibition on apolipoprotein AI (apoAI) expression in a human hepatoma cell line (HepG2) transfected with full-length apoAI promoter attached to the chloramphenicol acetyl transferase (CAT) reporter gene. To control for transfection efficiency, the cells were cotransfected with the plasmid pCMV.SPORT-beta-gal containing the beta-galactosidase gene driven by the cytomegalovirus promoter. Treatment of these cells with varying concentrations of indomethacin (INDO, 0, 50, 100, and 300 micromol/L) resulted in a dose-dependent decrease in apoAI promoter activity (% acetylation corrected for beta-galactosidase activity: were 46.1 +/- 2.6, 29.9 +/- 1.2, 25.2 +/- 2.9, and 17.2 +/- 2.8, respectively, P <.001). INDO treatment did not cause significant changes in beta-galactosidase activity. A similar reduction in apoAI promoter activity was found after treating the cells with 50 micromol/L acetylsalicylic acid (ASA) (31.8 +/- 1.8%, P <.001), suggesting that the effect of INDO is related to COX inhibition rather than a peculiar effect of INDO. Nuclear run-off assays indicated that treatment of cells with 50 micromol/L INDO resulted in 31.4% reduction in apo A1 transcription rate (P <.0002). Northern blot analysis of RNA from HepG2 cells treated with 50 micromol/L of INDO for 72 hours showed that the apoAI mRNA concentration relative to G3PDH mRNA was 4,043.0 +/- 84.6 and 3,064.0 +/- 49.8 in control and INDO-treated cells, respectively (P <.0006). Kinetic studies of apoAI mRNA in HepG2 cells indicated that the half-life of apoAI mRNA was not significantly altered with 50 micromol/L INDO treatment. Apo AI mRNA half-life was 25.3 hours in control cells and 26.9 hours in INDO-treated cells. Western blot analysis of culture media of HepG2 cells treated with 50 micromol/L of INDO for 72 hours showed a significant reduction in apoAI protein (6,760.0 +/- 318.1 v 4,773.0 +/- 112.0 arbitrary units, P <.004). Treatment of cells with either arachidonic acid (COX substrate) or various prostanoids including prostaglandin I(2), thromboxane B(2), (+/-)5-HETE, or (+/-)12-HETE did not significantly alter apoAI promoter activity. However, prostaglandin E(1) and E(2) at the highest concentration tested (50 nmol/L) significantly repressed apoAI promoter activity. COX activity measurements in HepG2 cells verified the efficacy of COX inhibition by INDO. It is concluded that COX inhibition with INDO or ASA downregulates apoAI expression at the transcriptional level. This effect could not be attributed to either arachidonic acid excess or to a deficiency in various prostanoids tested.

Apolipoprotein A-I↗

Effectiveness of an AI-based home exercise app for rehabilitation of rotator cuff-related shoulder pain: A randomized controlled trial.

BACKGROUND: Rotator cuff-related shoulder pain contributes to disability and healthcare use. Although therapeutic exercise is first-line treatment, limited supervision and adherence may reduce its effectiveness; digital rehabilitation with real-time feedback may address these limitations. OBJECTIVES: To evaluate the effectiveness of adding a digital rehabilitation program to standard physiotherapy on pain, function, fear-avoidance beliefs, and healthcare utilization. DESIGN: Single-center, assessor-blinded, randomized controlled trial with two parallel groups. METHOD: Forty-six adults (mean age 59 years) with rotator cuff-related shoulder pain were randomized to 12 weeks of conventional physiotherapy or physiotherapy plus an AI-based digital rehabilitation program using computer vision for real-time feedback and performance monitoring. Outcomes were assessed at baseline and at 2, 4, and 12 weeks. Pain intensity (NPRS) was primary outcome; secondary outcomes included upper limb function (QuickDASH), fear-avoidance beliefs (FABQ), and post-intervention healthcare utilization. Analyses followed an intention-to-treat approach. RESULTS: Pain reduction exceeded the MCID (1.3) at 4 and 12 weeks. Between-group differences favoured the intervention at Weeks 2 and 4 (MD -0.7; 95% CI -1.13 to -0.14 and MD -1.01; 95% CI -1.8 to -0.2, respectively). Upper limb function improved more at Week 4 (MD -7.3; 95% CI -12.3 to -2.2). FABQ scores decreased more at Week 12 (MD -7.6; 95% CI -14 to -0.5). Fewer participants in the experimental group required post-intervention healthcare (3 vs 10; p&#x202f;=&#x202f;0.02). CONCLUSION: Adding AI-based home exercise app to conventional treatment improve pain and may improve function and reduce healthcare utilization in rotator cuff-related shoulder pain.

Humans↗

Fertility following fixed-time AI in CIDR-treated beef heifers given GnRH or estradiol cypionate and fed diets supplemented with flax seed or sunflower seed.

The objectives were to determine pregnancy rates following fixed-time AI (FTAI) in heifers: (1). given GnRH or estradiol cypionate (ECP) to synchronize follicular wave emergence and ovulation in a CIDR-based protocol; and (2). fed diets supplemented with flax or sunflower seeds. At two locations, Angus and crossbred Angus heifers (n=983) were examined ultrasonically to confirm reproductive maturity and randomly allocated to six synchronization groups in a 2 x 3 factorial design. On Day 0 (start of synchronization treatments), heifers received a CIDR and either 100 microg GnRH i.m. (n=492) or 1mg ECP plus 50 mg progesterone i.m. (n=491); in these groups, CIDR removal and PGF treatment were done concurrently on Days 7 and 8.5, respectively. Heifers were re-randomized to receive 0.5 mg ECP i.m. at CIDR removal or 24 h later (with FTAI 58-60 h after CIDR removal in both groups), or 100 microg GnRH i.m. concurrent with FTAI (52-54 h after CIDR removal). The heifers were fed a barley silage-based diet for 50 days (from Day -25 to 25) supplemented with 1kg/heifer per day of flax seed (n=321), sunflower seed (n=324), or no oilseed (n=338). Pregnancy rate to FTAI (overall, 56.2%) was not affected by treatment at CIDR insertion (P = 0.96) but was higher (P < 0.05) in heifers given ECP 24h after CIDR removal (216/330, 65.4%) than in those given either ECP at CIDR removal (168/322, 52.1%) or GnRH at AI (169/331, 51.1%). Overall, there was no effect of diet on pregnancy rates (P = 0.46). In summary, pregnancy rate to FTAI was not significantly affected by treatment at CIDR insertion to synchronize follicular wave emergence, but 0.5mg ECP 24h after CIDR removal (to synchronize ovulation) resulted in the highest pregnancy rate.

Animals↗

Usefulness of a triple fluorochrome combination Merocyanine 540/Yo-Pro 1/Hoechst 33342 in assessing membrane stability of viable frozen-thawed spermatozoa from Estonian Holstein AI bulls.

In a situation where technology allows for the simultaneous measurement of numerous parameters of a single sperm cell, it becomes crucial to choose those parameters which may be useful in estimating in vivo fertility. Sperm membrane destabilization is believed to occur during chilling of semen, although its effect on the post-thaw (PT) fertility of the spermatozoa has not yet been fully assessed. For this reason, we tested a new combination of fluorophores, Merocyanine 540 (M540)/Yo-Pro 1/Hoechst 33342 (H33342), to detect sperm plasma membrane destabilization in bull spermatozoa conventionally processed for artificial insemination (AI). The samples were tested by flow cytometry (FC), both immediately PT and following an in vitro swimup (SU) technique, and results were thereafter compared with conventional sperm quality measurements (of concentration, motility, morphology, and membrane integrity), including in vivo fertility. Semen samples from six Estonian Holstein (EHF) AI bulls, frozen when the sires were aged 3, 5, and 7 years, allowed us to test the effect of bull age on quality of semen. Plasma membrane stability correlated to motility, normal head morphology (p<0.05), and membrane integrity (p<0.01). Following the SU selection, motility, membrane integrity (p<0.001), and membrane instability increased (p<0.01), as did stability (p<0.05). Bull age did not influence the degree of sperm membrane destabilization, except for the 3-year sample versus 7-year sample, in which the proportion of spermatozoa with destabilized plasma lemma increased PT (p<0.05) without affecting membrane integrity. Only parameters measured after SU, such as proportion of total motile and linearly motile spermatozoa, assessed with computer-assisted sperm analysis (CASA) (p<0.01), average path velocity (VAP) (p<0.001), and percentage of spermatozoa with unstable plasma lemma (p<0.05), had a significant relationship with non-return rate (NRR). The results indicate that a triple combination of the fluorophores M540/Yo-Pro 1/H33342 is suitable for monitoring the status of membrane stability in frozen-thawed (FT) bull spermatozoa. As well, a SU preselection method seems helpful in distinguishing relationships between sperm quality and fertility among bulls in a homogenous sire population.

Aging↗

Effect of timing of prostaglandin administration, controlled internal drug release removal and gonadotropin releasing hormone administration on pregnancy rate in fixed-time AI protocols in crossbred Angus cows.

Two experiments were conducted to investigate the effects of timing of prostaglandin F2(alpha) (PGF2(alpha)) administration, controlled internal drug release device (CIDR) removal and second gonodotropin releasing hormone (GnRH) administration on the pregnancy outcome in CIDR-based synchronization protocols. In Experiment 1, suckled Angus crossbred beef cows (n = 580) were given 100 microg of GnRH+a CIDR on Day 0. Cows in Group 1 (modified Ovsynch-P) received 25 mg of dinoprost (PGF2(alpha)) and CIDR device removal on Day 8 (AM), 100 microg of GnRH 36 h later on Day 9 (p.m.), and fixed-time AI (FTAI) 16 h later on Day 10 (47.5+/-1.1 h after PGF2(alpha)). Cows in Group 2 (Ovsynch-P) received 25mg of PGF2(alpha) and CIDR device removal on Day 7 (p.m.), 100 microg of GnRH 48 h later on Day 9 and FTAI 16 h later on Day 10 (66.6+/-1.2 h after PGF2(alpha)). Pregnancy rates were 56.5% (170/301) for Group 1 and 55.6% (155/279) for Group 2, respectively (P = 0.47). In Experiment 2, beef cows (n=734) were synchronized with 100 microg of GnRH+CIDR on Day 0, 25 mg of PGF2(alpha) and CIDR device removal on Day 7 and either 100 microg of GnRH 48 h later on Day 9 (Ovsynch-P) and FTAI 16 h later on Day 10 (64.9+/-3.3 h from PGF2(alpha)) or 100 microg of GnRH on Day 10 (CO-Synch-P) at the time of AI (63.2+/-4.2 h from PGF2(alpha)). Pregnancy rates were 48.8% (180/369) for Ovsynch-P and 44.7% (163/365) for CO-synch-P groups, respectively (P = 0.11). In both experiments, there was a locationxtreatment interaction (P<0.05); pregnancy rates between locations were different (P < 0.05) in the Ovsynch-P group. In conclusion, in a CIDR-based Ovsynch synchronization protocol, delaying administration of prostaglandin and CIDR removal by 12 h, or timing of the second GnRH by 16 h, did not affect pregnancy rates to FTAI. Therefore, there may be an opportunity to make changes in synchronization protocols with out adversely affecting FTAI pregnancy rates.

Animals↗

The effect of type of vaginal insert and dose of pLH on embryo production, following fixed-time AI in a progestin-based superstimulatory protocol in Nelore cattle.

The objective was to analyze and report field data focusing on the effect of type of progesterone-releasing vaginal insert and dose of pLH on embryo production, following a superstimulatory protocol involving fixed-time artificial insemination (FTAI) in Nelore cattle (Bos taurus indicus). Donor heifers and cows (n = 68; 136 superstimulations over 2 years) received an intravaginal, progesterone-releasing insert (CIDR or DIB, with 1.9 or 1.0 g progesterone, respectively) and 3-4 mg of estradiol benzoate (EB) i.m. at random stages of the estrous cycle. Five days later (designated Day 0), cattle were superstimulated with a total of 120-200 mg of pFSH (Folltropin-V), given twice daily in decreasing doses from Days 0 to 3. All cattle received two luteolytic doses of PGF2alpha at 08:00 and 20:00 h on Day 2 and progesterone inserts were removed at 20:00 h on Day 3 (36 h after the first PGF2alpha injection). Ovulation was induced with pLH (Lutropin-V, 12.5 or 25 mg, i.m.) at 08:00 h on Day 4 with FTAI 12, 24 and in several cases, 36 h later. Embryos were recovered on Days 11 or 12, graded and transferred to synchronous recipients. Overall, the mean (+/-S.E.M.) number of total ova/embryos (13.3 +/- 0.8) and viable embryos (9.4 +/- 0.6) and pregnancy rate (43.5%; 528/1213) did not differ among groups, but embryo viability rate (overall, 70.8%) was higher in donors with a DIB (72.3%) than a CIDR (68.3%, P = 0.007). In conclusion, the administration of pLH 12 h after progesterone removal in a progestin-based superstimulatory protocol facilitated fixed-time AI in Nelore donors, with embryo production, embryo viability and pregnancy rates after embryo transfer, comparable to published results where estrus detection and AI was done. Results suggested a possible alternative, which would eliminate the need for estrus detection in donors.

Administration, Intravaginal↗

Microscopic and flow cytometric semen assessment of Dutch AI-bucks: effect of semen processing procedures and their correlation to fertility.

This study was done to determine the effects of processing techniques on the quality of semen from Dutch AI-bucks with the view on improving pregnancy rates after artificial insemination (AI) with liquid or frozen-thawed semen. Motility of spermatozoa was estimated under a microscope whereas the percentage live spermatozoa and the percentage live spermatozoa with intact acrosomes were determined by means of flow cytometry. Aspects of semen processing that were investigated are storage temperature of liquid semen (i), the effect of glycerol on liquid-stored semen (ii), removal of seminal plasma (iii) and type of extender (iv). The correlation between semen quality and fertility rates in inseminated does was also investigated. The percentage motile spermatozoa in semen stored in liquid form for 72 h progressively declined over time, irrespective of whether storage occurred at 4 or 18 degrees C. The percentage motile spermatozoa in semen stored at 18 degrees C was similar to that in semen stored at 4 degrees C if stored for 24 h but lower if stored for 48 h. Goats differ in the sensitivity of their spermatozoa to the deleterious effects of glycerol. Neither the removal of seminal plasma nor the type of extender had any effect on semen quality before freezing but semen frozen in a Tris-citric acid-glucose (TCG) buffer with egg yolk without removal of the seminal plasma had better quality after thawing than semen frozen in another diluent or after removal of seminal plasma. Remarkably no significant correlation between fertility and membrane integrity of spermatozoa could be found. Thus, although integrity assays for spermatozoa are useful to asses resistance to semen handling, the validity of these assays for predicting fertility is questioned.

Animals↗

Stimulation of intestinal secretion of apolipoprotein AI by triiodothyronine.

Rats were made hyperthyroid with triiodothyronine in an osmotic minipump implanted intraperitoneally for one week. Intestinal lymph was collected from euthyroid and hyperthyroid rats for 40-55 hours. The rate of apolipoprotein AI (apo AI) secreted into the lymph by hyperthyroid rats exceeded that of euthyroid rats (149 +/- 9 vs 95 +/- 2 micrograms/hr), and was not associated with a proportional increase in the output of triglyceride. The fall in plasma concentration of apoAI in the euthyroid (10 mg/dl) and hyperthyroid (23 mg/dl) could be accounted for by the loss due to diversion of lymph. It appears that the intestine may contribute significantly to the increased plasma levels of apoAI observed in the hyperthyroid rats.

Animals↗

In vivo metabolism of apo A-I and apo A-II in subjects with apo A-I(Lys107-->0) associated with reduced HDL cholesterol and Lp(AI w AII) deficiency.

Apolipoprotein A-I (apo A-I) and apolipoprotein A-II (apo A-II) represent 80 90% of the protein content of high density lipoproteins (HDL). Previously we have identified a Finnish family with an apo A-I variant (Lys107-->0) associated with reduced plasma HDL cholesterol level and decreased lipoprotein (Lp)(AI w AII) concentration compared to unaffected family members. To determine the in vivo metabolism of apo A-I and apo A-II in the carriers of apo A-I (Lys107-->0) variant we radioiodinated normal apo A-I with 125I and apo A-II with 131I and compared the kinetic data of two heterozygous apo A-I(Lysl07-->0) patients (HDL cholesterol leves 0.31 and 0.69 mmol/l) to that of eight normolipidemic, healthy control subjects. Plasma radioactivity curves of 125I-labelled normal apo A-I of the patients demonstrated accelerated clearance of apo A-I compared to control subjects. In the two patients the fractional catabolic rates (FCR) of apo A-I were 0.347/day and 0.213/day, respectively, while the mean FCR of apo A-I of the control subjects was 0.151 +/- 0.041/day. Similarly, the plasma decay curves of the 131I-labelled apo A-II showed more rapid clearance of apo A-II in the two patients than in control subjects. The FCR of apo A-II in the two patients were 0.470/day and 0.234/day, while the mean FCR of apo A-II in control subjects was 0.154 +/- 0.029/day. The calculated production rates of apo A-I were similar in patients and in control subjects, and the production rates of apo A-II were significantly higher in patients than in control subjects. Our results show that the Lp(AI w AII) deficiency in patients with the apo A-I(Lys107-->0) is associated with increased fractional catabolic rates of normal apo A-I and apo A-II, while the production rates of these apolipoproteins are normal (apo A-I) or slightly increased (apo A-II).

Apolipoprotein A-I↗

Assessment of sperm characteristics post-thaw and response to calcium ionophore in relation to fertility in Swedish dairy AI bulls.

The present study examined the relationship between bull sperm characteristics post-thawing, after swim-up, and after challenge to calcium ionophore in relation to fertility (56-d nonreturn rates) after artificial insemination (AI). Spermatozoa from 25 semen batches derived from 15 Swedish Red and White AI bulls were evaluated with regard to post-thaw motility, membrane integrity, and migration through a swim-up procedure. The swim-up separated spermatozoa were assessed in terms of sperm concentration, viability and capacitation status as well as their response to exogenous calcium ionophore (A23187). Acrosome reactions were evaluated by fluorescence microscopy and flow cytometry. Sperm motility and viability post-thawing were significantly correlated with fertility. For the swim-up separated semen, significant correlations to nonreturn rates were found for concentration, viability, number of viable spermatozoa and sperm capacitation status (Pattern F and Pattern B). The only parameter significantly correlated to fertility after the ionophore challenge was the percentage of acrosome-reacted spermatozoa with remaining equatorial fluorescence, as assessed by fluorescence microscopy, but not by flow cytometry. The regression analysis showed that combining the results of sperm membrane integrity assessment post-thawing with those of capacitation status after swim-up provided the best prediction of fertility. The accuracy of prediction did not improve when these parameters were combined with the percentage of spermatozoa in which acrosome reaction was induced by ionophore challenge.

Acrosome Reaction↗

Effects of estradiol cypionate (ECP) on ovarian follicular dynamics, synchrony of ovulation, and fertility in CIDR-based, fixed-time AI programs in beef heifers.

Estradiol cypionate (ECP) was used in beef heifers receiving a controlled internal drug release (CIDR; insertion = Day 0) device for fixed-time AI (FTAI) in four experiments. In Experiment 1, heifers (n = 24) received 1mg ECP or 1mg ECP plus 50mg commercial progesterone (CP) preparation i.m. on Day 0. Eight or 9 days later, CIDR were removed, PGF was administered and heifers were allocated to receive 0.5mg ECP i.m. concurrently (ECP0) or 24h later (ECP24). There was no effect of treatment (P = 0.6) on mean (+/-S.E.M.) day of follicular wave emergence (3.9+/-0.4 days). Interval from CIDR removal to ovulation was affected (P<0.05) only by duration of CIDR treatment (88.3+/-3.8h versus 76.4+/-4.1h; 8 days versus 9 days, respectively). In Experiment 2, 58 heifers received 100mg progesterone and either 5mg estradiol-17beta or 1mg ECP i.m. (E-17beta and ECP groups, respectively) on Day 0. Seven (E-17beta group) or 9 days (ECP group) later, CIDR were removed, PGF was administered and heifers received ECP (as in Experiment 1) or 1mg EB 24h after CIDR removal, with FTAI 58-60h after CIDR removal. Follicular wave emergence was later (P<0.02) and more variable (P<0.002) in heifers given ECP than in those given E-17beta (4.1+/-0.4 days versus 3.3+/-0.1 days), but pregnancy rate was unaffected (overall, 69%; P = 0.2). In Experiment 3, 30 heifers received a CIDR device and 5mg E-17beta, with or without 100mg progesterone (P) i.m. on Day 0. On Day 7, CIDR were removed and heifers received ECP as described in Experiment 1 or no estradiol (Control). Intervals from CIDR removal to ovulation were shorter (P<0.05) in ECP0 (81.6+/-5.0h) and ECP24 (86.4+/-3.5h) groups than in the Control group (98.4+/-5.6h). In Experiment 4, heifers (n = 300) received a CIDR device, E-17beta, P, and PGF (as in Experiment 3) and after CIDR removal were allocated to three groups (as in Experiment 2), with FTAI 54-56h (ECP0) or 56-58h (ECP24 and EB24) after CIDR removal. Pregnancy rate did not differ among groups (overall, 63.6%, P = 0.96). In summary, although 1mg ECP (with or without progesterone) was less efficacious than 5mg E-17beta plus 100mg progesterone for synchronizing follicular wave emergence, 0.5mg ECP (at CIDR removal or 24h later) induced a synchronous ovulation with an acceptable pregnancy rate to fixed-time AI.

Animals↗

Growth hormone gene polymorphism and reproductive performance of AI bulls.

Relationships between the growth hormone gene RFLP polymorphism and bull sperm characteristics were the objects of the present study. DNA was extracted from blood or sperm samples collected from 113 AI bulls and submitted for polymerase chain reaction (PCR) followed by digestion with Alu I restriction enzyme. The bGH genotypes were visualized on 10% polyacrylamide gel. The analyzed population of AI bulls consisted of dairy (Holstein Fresian [HF] crossbred [HF x Polish Black and White]) and beef breeds (Limousine, Charolaise, Piemontese, Angus and Hereford). The frequency of the Leu allele was 0.86 among dairy bulls and 0.38 in beef bulls (0.14 and 0.62 for the Val allele, respectively). Eight sperm characteristics and Day 60 non-return rates (NRR) were analyzed. The 3 genotype groups (LL, VV and LV) and the effect of production type (dairy or beef) on sperm characteristics were considered. None of the traits showed significant variability in relation to the bGH genotype, although a tendency was observed for LL bulls to have a lower ejaculate volume and VV bulls higher NRR. Moreover some statistically significant associations with production type were noticed: beef bulls were superior in sperm concentration and non-return rate, whereas dairy bulls excelled in individual fresh sperm motility.

Animals↗

Apolipoproteins (a), AI, and B and parental history in men with early onset ischaemic heart disease.

Middle-aged men who had had a myocardial infarction were compared with controls matched for social background, age, cigarette-smoking, blood pressure, and alcohol consumption. Serum cholesterol, triglycerides, very low density lipoprotein, low density lipoprotein, high density lipoprotein (HDL), HDL2 and HDL3 cholesterol, and serum apolipoproteins (apo) (a), AI, and B were measured. Discriminant analysis showed that the combination of these variables that best distinguished patients from controls was provided by apo AI and apo B and a knowledge of parental history of early cardiac death, the most discriminating single factor being apo B. No other variable contributed more than these. Apo (a), however, could be substituted for parental history, which had a major influence on the serum concentration of apo (a). Apo (a) concentration accounted for much of the familial predisposition to cardiac ischaemia. These findings may prove valuable in the clinical assessment of genetic susceptibility to myocardial infarction. They also support the hypothesis that serum apo (a) concentration is a genetic trait that predisposes to arterial thrombosis. Apo B emerged as the main lipoprotein determinant of coronary disease risk.

Apolipoprotein A-I↗