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PubMed2026

Artificial intelligence-supported double reading in European population breast cancer screening: A systematic review and meta-analysis of prospective programs.

BACKGROUND: Most European population mammography screening programs rely on double reading with arbitration, a model that delivers mortality benefit but is increasingly challenged by radiologist workload, variable specificity, and interval cancers. Artificial intelligence (AI) is being evaluated to support or optimize these established European screening pathways. PURPOSE: To synthesize prospective or program-embedded evaluations of AI conducted within European-style population screening programs and to estimate exploratory program-level absolute risk differences (RDs) per 1000 examinations for cancer detection rate (CDR) and recall. MATERIALS AND METHODS: We performed a prespecified, focused evidence synthesis of three large studies embedded within routine population screening programs operating under European-relevant workflows: MASAI (randomized AI-supported risk triage within a national program), ScreenTrustCAD (prospective paired-reader evaluation with AI as an independent reader in a double-reading framework), and PRAIM (nationwide decision-referral implementation). Outcomes were harmonized as AI-control RDs per 1000 examinations. Random-effects pooling used Hartung-Knapp-Sidik-Jonkman models. For the paired-reader design, sensitivity analyses applied a Kish effective sample-size approach across plausible within-examination correlations (ρ = 0.3-0.8). Positive predictive value (PPV) and workflow/time outcomes were summarized descriptively. RESULTS: Across 597,419 examinations, the pooled CDR RD was +0.9 per 1000 (95% CI -0.0 to +1.8; I2 ≈ 12%), consistent with a modest directional increase with borderline statistical uncertainty. The pooled recall RD was -0.6 per 1000 (95% CI -3.1 to +2.1; I2 ≈ 41-43%), indicating no consistent recall increase across screening programs. Where reported, PPV was higher with AI-supported screening. Efficiency signals included 44.3% fewer total readings in MASAI and shorter reading times for AI-normal examinations in PRAIM; in PRAIM, a program-level safety-net mechanism recovered 204 cancers that would otherwise have been missed. CONCLUSION: In European population screening programs characterized by double reading and arbitration, prospective program-embedded evidence suggests that AI integration may yield a small absolute increase in cancer detection (≈1/1000) without a consistent increase in recall, alongside improved PPV and efficiency signals. These findings suggestAI primarily as a complementary reader within European screening workflows, with implementation requiring explicit quality assurance and monitoring of interval cancers and stage distribution.

Humans↗

PubMed2005

The effect of backpack weight on the standing posture and balance of schoolgirls with adolescent idiopathic scoliosis and normal controls.

Concerns have been raised regarding the effect of carrying a backpack on adolescent posture and balance, but the effect of backpack loading combined with other factors affecting balance, such as adolescent idiopathic scoliosis (AIS), has not been determined. This study examines the effects of backpack load on the posture and balance of schoolgirls with AIS and normal controls. The standing posture of 26 schoolgirls with mild AIS (mean age 13, Cobb angle 10-25 degrees ) and 20 age-matched normal schoolgirls were recorded without a backpack and while carrying a standard dual-strap backpack loaded at 7.5%, 10%, 12.5% and 15% of the subject's bodyweight (BW). Kinematics of the pelvis, trunk and head were recorded using a motion analysis system and centre of pressure (COP) data were recorded using a force platform. Reliable COP data could only be derived for 13 of the subjects with AIS. Increasing backpack load causes a significantly increased flexion of the trunk in relation to the pelvis and extension of the head in relation to the trunk, as well as increased antero-posterior range of COP motion. While backpack load appears to affect balance predominantly in the antero-posterior direction, differences between groups were more evident in the medio-lateral direction, with AIS subjects showing poor balance in this direction. Overall, carrying a backpack causes similar sagittal plane changes in posture and balance in both normal and AIS groups. Load size or subject group did not influence balance, but the additive effect of backpack carrying and AIS on postural control alters the risk of fall in this population. Therefore, load limit recommendations based on normal subjects should not be applicable to subjects with AIS.

Adolescent↗

PubMed2005

[Use of aromatase inhibitors in infertile women].

Aromatase inhibitors (AI) block the last enzymatic step of estrogen production, the aromatization of the A-cycle of aromatizable androgens and particularly, androstenedione (D4) and testosterone (T). Molecules designed for interfering with aromatase activity have existed for many years. Yet the activity of products of the aminogluthetimide era was too unspecific and these substances carried too many side effects for being used clinically. Today, however, 3rd generation AIs have become available that are highly specific and essentially devoid of side effects. These molecules have recently been approved for treating breast cancer in post-menopausal women, either in advanced forms, or as part of adjuvant therapy. In women whose ovaries are active, a temporary inhibition of E2 production will activate gonadotropins and in turn, stimulate follicular growth. In cancer patients, this property precludes the use of AIs in women whose ovaries are still active, unless gonadotropins are blocked. In infertile patients, this property of AIs has been put to play for inducing ovulation. AIs have been used both in women who do not ovulate but whose hypothalamo-pituitary-gonadal (HPG) axis is active (oligo-anovulators of PCOD type) and in those who ovulate regularly but in whom multiple ovulation is sought for treating infertility or as part of IVF. Like CC, AIs are not usable in women whose gonadotropins are suppressed, as in the case of hypothalamic amenorrhea. The sum of data available on the use of AI for inducing ovulation remains however meager to this date and is mainly constituted of pilot and non-randomized trials. Yet mounting evidence tends to support AIs' advantages over CC for induction of ovulation. Hence, we think that these drugs will play a key role for the induction of ovulation in the future.

Anovulation↗

PubMed2026

Privacy, security, and reliability risks of artificial intelligence in healthcare: a systematic review of empirical evidence.

BACKGROUND: Artificial intelligence (AI) is increasingly integrated into healthcare information systems, supporting clinical decision-making, imaging analysis, and predictive modeling. While these applications offer operational and clinical benefits, they also introduce emerging risks to patient privacy, data security, and system reliability. OBJECTIVE: To systematically review empirical evidence on privacy breaches, security vulnerabilities, and misuse associated with AI applications in healthcare settings. METHODS: PubMed, Embase, Web of Science, Scopus, IEEE Xplore, and ACM Digital Library were searched for empirical studies published between January 2015 and November 2025 that evaluated AI use or misuse in clinical diagnosis, treatment, or decision-making. Two reviewers independently screened studies and extracted data using a standardized form. Findings were synthesized narratively due to heterogeneity in study designs, AI methods, and reported outcomes. RESULTS: Of 7,285 records identified through database searches and 205 through citation screening, 22 empirical studies met the inclusion criteria, spanning multiple clinical domains and data modalities, predominantly medical imaging applications. Five recurring threat categories were identified: patient re-identification, membership inference, unauthorized access and adversarial exploitation, input manipulation, and misuse or overinterpretation of AI outputs. Across studies, AI models were shown to encode latent biometric signals across diverse data types, limiting the effectiveness of traditional anonymization and synthetic data approaches. Adversarial attacks and input manipulation were also shown to compromise diagnostic performance and system integrity. CONCLUSION: This systematic review provides empirical evidence suggesting that contemporary AI systems in healthcare introduce privacy and security risks that may challenge traditional assumptions about data protection. These findings underscore the need for privacy- and security-by-design approaches and governance frameworks that address risks across the AI lifecycle.

Humans↗

PubMed2005

The use of intravenous recombinant tissue plasminogen activator in acute ischemic stroke.

We sought to determine the frequency of use of intravenous (i.v.) recombinant tissue plasminogen activator (rt-PA) in patients presenting to our institution with acute ischemic stroke (AIS). This observational study involved keeping a log of all patients presenting to our institution with symptoms consistent with AIS who were potential candidates for emergency thrombolysis over a 3-year period. The log included brain computed tomography (CT) scan results, whether or not rt-PA was administered, and contraindications to thrombolysis. It also included each patient's time flow through the system, from symptom onset to decision time regarding (and administration of) thrombolytics. Over the 36-month period of the study, there were 142 patients who presented to the Emergency Department (ED) who initially were thought to be potential candidates for thrombolysis for AIS. Ninety-five (68.5%) of these 142 patients had a confirmed diagnosis of AIS. On further clarification of symptom onset, 77 (81%) of these 95 patients with AIS actually presented within 3 h, and 17 (22%) of these 77 patients met criteria for thrombolysis and had no contraindications. All 17 (100%) patients with AIS presenting within 3 h of onset and without contraindications received i.v. rt-PA in the ED. In conclusion, i.v. rt-PA can be administered for AIS within the 3-h window if a hospital is committed to providing this treatment. Thrombolysis remains a treatment for a minority of AIS patients.

Acute Disease↗

PubMed2006

A randomized, clinical trial comparing the efficacy of continuous nebulized albuterol (15 mg) versus continuous nebulized albuterol (15 mg) plus ipratropium bromide (2 mg) for the treatment of acute asthma.

Multiple studies have examined adding nebulized ipratropium bromide to intermittent albuterol for the treatment of acute asthma. Although continuous nebulized treatments in themselves offer benefits; few data exist regarding the efficacy of adding ipratropium bromide to a continuous nebulized system. To compare continuous nebulized albuterol alone (A) vs. albuterol and ipratropium bromide (AI) in adult Emergency Department (ED) patients with acute asthma, a prospective, randomized, double-blind, controlled clinical trial was conducted on a convenience sample of patients (IRB approved). The setting was an urban ED. Consenting patients > 18 years of age with peak expiratory flow rates (PEFR) < 70% predicted, between October 15 and December 28, 1999, were randomized to albuterol (7.5 mg/h) + ipratropium bromide (1.0 mg/h), or albuterol alone via continuous nebulization using the Hope Nebulizer (B&B Technologies Inc., Orangevale, CA) for 2 h. Main outcome measures were changed in mean improvement at 60 and 120 min PEFR compared to baseline (time 0). Secondary measures were admission rates. Data were analyzed using appropriate parametric and non-parametric tests (p < 0.05 statistically significant). Sixty-two patients (30 women) completed enrollment: 32 in (AI) and (30) in (A). Four (A) and 2 (AI) patients are without 120 min data: 3 (A) and 1 (AI) were discharged after 60 min, whereas one each (A) and (AI) worsened and were admitted before 120 min. There were no statistically significant differences between treatment groups in age, sex, predicted or initial PEFR. Thirteen (19.4%) patients were admitted. There was no statistically significant difference in improvement of mean PEFR at 60 min or 120 min compared to baseline, between groups, using repeated measures analysis of variance. Mean improvement in PEFR at 60 min compared to baseline (time 0): (A) = 93.2 L/min (95% confidence interval [CI] 64.5-121.8), (AI) = 86.6 L/min (95% CI 58.9-114.3); mean improvement in PEFR at 120 min compared to baseline (time 0) (A) = 116.5 L/min (95% CI 84.5-148.5), (AI) = 126.4 L/min (95% CI 95.4-157.4). There was no statistically significant difference in admission rates between groups: 5/30 (A) and 8/32 (AI) (p = 0.62). There were no significant differences in mean improvement of PEFR at either 60 or 120 min between ED patients with acute asthma receiving continuous albuterol alone vs. those receiving albuterol in combination with ipratropium bromide.

Adult↗

PubMed2004

Acute and chronic toxicological studies of Ajuga iva in experimental animals.

Ajuga iva (L.) Schreber (AI), is widely used in the Moroccan pharmacopoeia as a panacea (cure-all), and specifically for gastrointestinal disorders and diabetes, and as an anthelmintic. No toxicological investigations have been carried out on this plant. We have previously observed that single oral doses (2-14 g/kg) of a lyophilised aqueous extract of AI (AI-extract) in mice or daily oral administration of 10 mg/kg of AI-extract in rats for 2 weeks did not result in any adverse effects. We have now evaluated AI-extract for its behavioural and pharmaco-toxicological effects after acute and chronic administration by the oral and intraperitoneal routes in rats and mice. No toxicity was observed in mice after single oral doses of as high as 14 g/kg of the AI-extract. However, single intraperitoneal injections of the AI-extract (1500-5500 mg/kg BW) produced a dose-dependent increase in adverse effects in the general behaviour and the mortality rate; the LD50 of acute intraperitoneal dose was 3.6 g/kg. In chronic toxicological studies in rats, the AI-extract (administered orally at daily doses of 100, 300 and 600 mg/kg for 3 months), did not cause any changes in haematological and biochemical parameters, with the exception of a transient rise in platelet counts and a short-term decrease in serum glucose levels. Histopathological examination of the brain, liver and the kidneys at the end of the study (3 months) showed normal architecture suggesting no morphological disturbances.

Administration, Oral↗

PubMed2006

Hypolipidemic effects of acute and sub-chronic administration of an aqueous extract of Ajuga iva L. whole plant in normal and diabetic rats.

Diabetes is often accompanied by lipid abnormalities, which contribute significantly to cardiovascular (CV) morbidity and mortality in diabetic patients. The plant Ajuga iva (L.) Schreiber (Labiatea) is used in the treatment of diabetes in Moroccan folk medicine. Previously, we have demonstrated potent hypoglycemic activity and relatively non-toxic nature of a lyophilized aqueous extract of the whole plant (AI-extract) in normal (normoglycemic) and streptozotocin (STZ)-diabetic rats. In this study, we examined the AI-extract for its possible lipid-lowering activity in normal and STZ-diabetic rats. Taurine (TR) and glibenclamide (GLB) were used as reference substances. As shown previously, the AI-extract (10 mg/kg; oral) reduced plasma glucose levels after acute (single) and sub-chronic (3 weeks) dosing both in normal and diabetic rats. In normal rats, single and repeated oral administration of the AI-extract, at a dose of 10 mg/kg produced a small but significant decrease in plasma CHL levels (P<0.05). A single dose of the AI-extract did not produce a significant change in plasma TG, but sub-chronic dosing (for up to 21 days) caused a significant decrease in plasma TG (P<0.05). In STZ-diabetic rats, a single dose as well as repeated (3 weeks) treatment with the AI-extract produced a significant decrease in plasma CHL (P<0.01), and triglyceride (P<0.01) levels. The AI-extract also prevented weight loss in the diabetic animals. In summary, an aqueous extract of the Ajuga iva whole plant showed hypolipidemic activity, in addition to its hypoglycemic effect in normoglycemic and diabetic rats. In view of the hypoglycemic and hypolipidemic activity, and its relatively non-toxic nature (shown previously), Ajuga iva may be a candidate for development as an anti-diabetic agent in humans. Further studies are warranted to confirm our results and fractionate the AI-extract to isolate and identify the active principle(s), and to determine the exact mechanism(s) of action.

Administration, Oral↗

PubMed2005

Aromatase inhibitors for therapy of advanced breast cancer.

In postmenopausal women with advanced breast cancer, numerous phase III trials have been performed comparing the third-generation non-steroidal aromatase inhibitors (NS-AIs) anastrozole and letrozole and the steroidal AI (S-AI) exemestane in the "first-line" setting against tamoxifen and in the "second-line" setting against megestrol acetate. In both settings, the AIs were at least as efficacious or superior in some endpoints with a preferable toxicity profile including a lower incidence of thrombotic events. Relatively small differences in potency between the three AIs have been identified and it has not been demonstrated that these differences have clinical implications. The recent establishment of the value of AIs in the adjuvant setting for postmenopausal women will impact on their utilization in advanced disease. In premenopausal women the third-generation AIs have not been studied as monotherapy and there is a paucity of data in combination with ovarian function suppression in the advanced disease setting. The main area of future investigations for the AIs in premenopausal women will be in the adjuvant therapy setting in combination with suppression of ovarian function.

Anastrozole↗

PubMed2004

Artificial insemination following observational versus electronic methods of estrus detection in red deer hinds (Cervus elephus).

The objectives were to determine the efficacy of the HeatWatch (HW) electronic estrus detection system for monitoring behavioral estrus (including duration and intensity) in red deer hinds and to evaluate pregnancy rate to AI after detected estrus. Red deer hinds (Cervus elephus; n = 50) were allocated into two treatment groups: AI following synchronization (CIDR/PMSG) and observed estrus (induced estrus group: IE; n = 25) or AI following the detection of natural estrus (NE; n = 25) without hormonal treatment. Hinds were fitted with two HeatWatch (HW) electronic estrus detection transmitters, one above the tail (bottom) and one between the tuber coxae of the pelvic girdle (top), and visual observations for mounting activity began with the aid of young sterile red deer stags (18 months old) fitted with marking harnesses. Hinds in both groups were inseminated (10-12h after observed estrus) with frozen-thawed red deer semen using a transvaginal/cervical AI approach. Following a 26-day period of AI, hinds were placed with a mature fertile stag for an additional 30-day natural breeding period. Pregnancy diagnosis was performed 57 and 86 days after the start of AI. While the hinds were housed with the young stags, 82% were detected in estrus by visual appraisal of stag crayon marks, but only 32% of these were detected by HW. In contrast, in the hinds housed with the mature stag, 93% detected in estrus by crayon marks were also detected by HW. The top HW transmitter consistently recorded more mounts (P < 0.05) than the bottom transmitter. The pregnancy rate was numerically better in IE versus NE hinds (42% versus 29%, P > 0.10). In summary, there were no differences (P > 0.10) in the intensity (number) or duration of mounts (detected by HW) during estrus in IE versus NE hinds, and HW was most effective in detecting estrus in the presence of a heavier, mature stag versus a younger stag. When used in combination with transvaginal AI, an overall first-service pregnancy rate of 36.6% was achieved with AI of frozen-thawed semen in red deer hinds following detected estrus.

Animals↗

PubMed2026

Decoding cancer with artificial intelligence: Transforming research, diagnosis, and therapy with future insights.

Cancer remains one of the leading global health burdens, with increasing complexity in genomic, imaging, and clinical datasets presenting significant challenges for effective management. Artificial intelligence (AI) has emerged as a powerful tool to address these challenges by enabling pattern recognition, knowledge integration, and data-driven decision-making. This review highlights recent advances in the application of AI across cancer research, diagnosis, and therapy. In research, AI accelerates drug discovery and repurposing, enhances genomic data interpretation, and facilitates biomarker identification through multi-omics integration. In diagnosis, AI has demonstrated high technical performance in radiology for lesion detection and image segmentation, in pathology for tumour grading and molecular prediction, and in liquid biopsy for non-invasive biomarker analysis. In therapy, AI supports precision medicine by predicting treatment responses, monitoring disease progression, and optimizing clinical trial design. Despite these advances, barriers such as data heterogeneity, algorithmic bias, interpretability, and regulatory challenges remain. Future directions, including explainable AI, federated learning, multimodal modelling, and digital twins, hold promise for translating AI-driven innovations into routine oncology practice. Significance Statement This review provides a timely synthesis of recent (2020-2025) advances in artificial intelligence across cancer research, diagnosis, and therapy, highlighting applications in drug discovery, genomics, multi-omics biomarker identification, and clinical decision-making. By integrating technological progress with translational and clinical relevance, this work serves as a valuable resource for bridging AI innovation with precision oncology practice. As a narrative review, the literature was identified through targeted PubMed, Scopus, and Google Scholar searches, combining terms for artificial intelligence, machine learning, and deep learning with cancer-related keywords, with priority given to peer-reviewed studies published between 2020 and 2025, seminal earlier works, and official regulatory or guideline documents. Within each domain, representative studies were selected to illustrate methodological diversity, clinical context, and current translational readiness rather than to provide exhaustive coverage of an extremely rapidly evolving field.

Artificial intelligence↗

PubMed2006

Ornithine deficiency in the arginase double knockout mouse.

Knockout mouse models have been created to study the consequences of deficiencies in arginase AI and AII, both individually and combined. The AI knockout animals die by 14 days of age from hyperammonemia, while the AII knockout has no obvious phenotype. The double knockout (AI(-/-)/AII(-/-)) exhibits the phenotype of the AI-deficient mice, with the additional absence of AII not exacerbating the observed phenotype of the AI knockout animals. Plasma amino acid measurements in the double knockout have shown arginine levels increased roughly 100-fold and ornithine decreased roughly 10-fold as compared to wildtype. Liver ornithine levels were reduced to 2% of normal in the double knockout with arginine very highly elevated. Arginine and ornithine were also altered in other tissues in the double knockout mice, such as kidney, brain, and small intestine. This is the first demonstration that the fatal hyperammonemia in the AI knockout mouse is almost certainly due to ornithine deficiency, the amino acid needed to drive the urea cycle. Others have shown that the expression of ornithine aminotransferase (OAT) rapidly decreases in the intestine at the same age when the AI-deficient animals die, indicating that this enzyme is critical to the maintenance of ornithine homeostasis, at least at this early stage of mouse development. Although most human AI-deficient patients have no symptomatic hyperammonemia at birth, it is possible that clinically significant ornithine deficiency is already present.

Animals↗

PubMed2000

Athens Insomnia Scale: validation of an instrument based on ICD-10 criteria.

OBJECTIVES: To describe and validate the Athens Insomnia Scale (AIS). METHODS: The AIS is a self-assessment psychometric instrument designed for quantifying sleep difficulty based on the ICD-10 criteria. It consists of eight items: the first five pertain to sleep induction, awakenings during the night, final awakening, total sleep duration, and sleep quality; while the last three refer to well-being, functioning capacity, and sleepiness during the day. Either the entire eight-item scale (AIS-8) or the brief five-item version (AIS-5), which contains only the first five items, can be utilized. The validation of the AIS was based on its administration to 299 subjects: 105 primary insomniacs, 144 psychiatric patients and 50 non-patient controls. RESULTS: Regarding internal consistency, for both versions of the scale, the Cronbach's alpha was around 0. 90 and the mean item-total correlation coefficient was about 0.70. Moreover, in the factor analysis, the scale emerged as a sole component. The test-retest reliability correlation coefficient was found almost 0.90 at a 1-week interval. As far as external validity is concerned, the correlations of the AIS-8 and AIS-5 with the Sleep Problems Scale were 0.90 and 0.85, respectively. CONCLUSION: The high measures of consistency, reliability, and validity of the AIS make it an invaluable tool in sleep research and clinical practice.

Adolescent↗

PubMed1998

The relationship between circadian patterns of salivary cortisol and endogenous inhibitor of monoamine oxidase A.

The circadian pattern of free cortisol, measured in saliva, was monitored in normal healthy adults (N=41) for the first half hour immediately after awakening and in a smaller group (N=8) at timed intervals throughout the day. The endogenous inhibitor of monoamine oxidase A (MAO-AI) was measured in the same saliva samples in order to explore the relationship between circadian activation of the hypothalamic-pituitary-adrenocortical (HPA) axis and MAO-AI. A marked elevation of salivary cortisol was recorded in the first half hour immediately after awakening resulting in a two to three fold increase from the first awakening level. By contrast MAO-AI was highest immediately upon awakening and fell subsequently. Hence the cortisol response to awakening is preceded by heightened MAO-AI. Moreover those subjects who showed more persistently elevated MAO-AI were characterised by a more pronounced cortisol response. An association between MAO-AI and cortisol was also manifest in the diurnal pattern recorded at timed intervals throughout the day. The decline of salivary cortisol from the morning acrophase to the evening nadir was paralleled by MAO-AI. Both patterns of decline were significant (P< 0.01). Taken together with previously reported psychological stress studies these findings suggest a possible relationship between MAO-AI and HPA activity.

Adult↗

PubMed1997

Fertility and ovum fertilization rate after laparoscopic or transcervical intrauterine artificial insemination of oxytocin-treated ewes.

Based on our previous work, we found that exogenous oxytocin induces uterine tetany and cervical dilation, and permits transcervical access to the uterus. However, the oxytocin does not reduce sustained sperm transport from the uterus to the oviducts. Thus, we hypothesized that exogenous oxytocin may be a useful adjunct to transcervical intrauterine AI procedures for sheep: two experiments were conducted to test our hypothesis. In Experiment 1, purebred ewes (n = 75/group) were artificially inseminated intrauterine with either laparoscopic or oxytocin-transcervical (i.e., 200 USP units of oxytocin 30 min before AI) procedures. At 54 h after progestogenated pessaries were removed, ewes were inseminated with 200 x 10(6) sperm/0.25 ml of fresh, extended semen, which was collected from a purebred ram of the corresponding breed. Pregnancy rate was greater (P < 0.05) after laparoscopic (37.5%) than after transcervical AI (0%). Because of the disappointing results of Experiment 1, Experiment 2 was conducted to determine whether oxytocin or the AI procedure per se reduced ovum fertilization rate. Treatments were designed in a 2 x 2 factorial arrangement. At 60 h after norgestomet implant removal and 10 min before either laparoscopic or transcervical (cervical in a saline group) AI with 100 x 10(6) sperm/0.25 ml, ewes (n = 10/group) received an intravenous injection of either isotonic saline or 200 USP units of oxytocin. Fertilization rate, which was determined 72 h after AI, was greater (P < 0.05) after laparoscopic than after transcervical/cervical AI (92.5 vs 28%), but oxytocin treatment did not affect fertilization rate. The results indicate that exogenous oxytocin did not reduce ovum fertilization rate, but the transcervical AI procedure per se seemed to reduce fertilization rate.

Journal Article↗

PubMed1998

Normal calves from transfer of biopsied, sexed and vitrified IVP bovine embryos.

Data on biopsied, sexed and cryopreserved in vitro produced (IVP) bovine embryos, and their in vivo developmental competence are very limited. Two preliminary studies were conducted before the primary study. In Experiment 1, post-thaw in vitro developmental competence of biopsied and vitrified IVP embryos was evaluated using re-expansion as an endpoint. In Experiment 2, the pregnancy rates of biopsied fresh, frozen or vitrified embryos following single embryo transfer were compared. Since vitrified embryos resulted in a higher pregnancy rate than frozen-thawed embryos, in the primary study (Experiment 3), all IVP embryos were vitrified following biopsy and sexing (by DNA fingerprinting). In Experiment 3, we compared pregnancy initiation and calving results of heifers in the following treatments: 1) artificial insemination (AI); 2) AI plus contralateral transfer of a single embryo (AI + SET); 3) ipsilateral transfer of single embryo (SET); or 4) bilateral transfer of two embryos (DET). Birth weights, gestation lengths and dystocia scores were recorded. In Experiment 1, post-thaw re-expansion rate of biopsied and vitrified embryos was 85% (70/82). In Experiment 2, pregnancy rates (90 d) were 44% (7/16), 23% (3/13), and 50% (7/14) for vitrified, frozen and fresh embryos, respectively (P < 0.10). In Experiment 3, pregnancy rates of AI and SET were 65% (20/31) and 40% (16/40), respectively (P < 0.05). The pregnancy rate of AI + SET was 75% (27/36) with 11 carrying twins, and the pregnancy rate of DET was 72% (26/36) with 10 carrying twins. All AI fetuses were carried to term, but only half the SET fetuses were carried to term. Similar calving rates were observed in the AI + SET and DET groups, 76 and 70%, respectively, of those pregnant at Day 40. Mean birth weight, dystocia score and gestation length of AI calves were not different from those of SET calves. Mean birth weight and dystocia score of single-born calves were greater than those of twin born calves (P < 0.05). These data demonstrate that biopsied IVP bovine embryos can be successfully cryopreserved by vitrification and following post-thaw embryo transfer, acceptable rates of offspring with normal birth weights can be obtained without major calving difficulties.

Animals↗

PubMed1999

Postpartum subestrus in dairy cows: comparison of treatment with prostaglandin F2 alpha or GnRH + prostaglandin F2 alpha + GnRH.

Two experiments (Experiment 1, 185 cows in 1996/97; Experiment 2, 168 cows in 1997/98) were conducted with Prim Holstein dairy cattle in the Mayenne region of France to investigate subestrus. Cows which had not been observed in estrus since calving were allocated alternately to treatment groups between 60 and 90 d post partum as follows: Experiment 1-Group 1: GnRH (Day 0, 100 micrograms i.m.), PGF2 alpha (Day 7, 25 mg i.m.), GnRH (Day 9, 100 micrograms i.m.) and AI (Day 10); Group 2: PGF2 alpha (Day 0, 25 mg i.m.), AI at estrus, or, if estrus was not observed, a second PGF2 alpha injection on Day 13, and AI on Day 16 and Day 17. Treatments in Experiment 2 were as follows: Group 1: as Experiment 1-Group 1 but AI at the observed estrus after Day 0, or at Day 10 if estrus was not observed; Group 2: as Experiment 1--Group 2, however, if a second PGF2 alpha injection was given on Day 13, AI at the observed estrus. Progesterone was measured in serum at Day 0 and in milk at AI. Pregnancy diagnosis was performed by measuring bovine pregnancy-specific protein B (bPSPB; Day 50 +/- 3) and confirmed by ultrasonography when the result was doubtful. In Experiment 1, farmers observed 47/101 (46.9%) Group 1 cows in estrus, 33/91 cows on Day 10 and 10 cows before Day 10. The progesterone concentrations were compatible with estrus in 69/86 (80%) cows on Day 10. In Group 2, 36/83 (43.4%) cows were inseminated after the first PGF2 alpha injection. After the second PGF2 alpha injection, only 29/43 (67%) cows had a low progesterone concentration at AI. Pregnancy rates were 36.1 and 32.5% for Groups 1 and 2, respectively. In Experiment 2, estrus was observed in 31/93 (33.7%) Group 1 cows. In Group 2, 51/75 (66%) cows were inseminated after the first injection of PGF2 alpha, 13/75 (17.3%) cows after the second injection, while 11/75 (14.7%) were not observed in estrus. Pregnancy rates were 53.7 and 53.3% in Groups 1 and 2, respectively. In conclusion, it is recommended that subestrus be treated with PGF2 alpha followed by AI at the observed estrus when estrus detection is good, while the use of GnRH + PGF2 alpha + GnRH is recommended when estrus detection is poor.

Animals↗

PubMed1999

Conception rates after artificial insemination or embryo transfer in lactating dairy cows during summer in Florida.

The objective was to compare conception rates to embryo transfer relative to AI, during summer heat stress, in lactating dairy cows. Holstein cows (n = 180; 50 to 120 d postpartum) were allocated randomly to 1 of 3 groups: artificial insemination (AI, n = 84), embryo transfer using either embryos collected from superovulated donors (ET-DON, n = 48), or embryos produced in vitro (ET-IVF, n = 48). Embryos from superovulated donors were frozen in 10% glycerol and were rehydrated in a 3-step procedure, in decreasing concentrations of glycerol in a sucrose medium before transfer. Embryos produced in vitro were frozen in 1.5 M ethylene glycol, thawed and transferred without rehydration. Blood samples were collected from AI and ET recipients on Days 0, 7 and 22 for measurement of progesterone in plasma. Conception rate was estimated for the three groups at Day 22 (progesterone > 1 ng/mL) and confirmed at Day 42 by palpation per rectum. Conception rate estimates at Day 22 did not differ among groups (AI, 60.7%; ET-DON, 60.4%; ET-IVF, 54.2%), but conception rates at Day 42 differed (AI, 21.4%; ET-DON, 35.4%; ET-IVF, 18.8%; AI versus ET: P > 0.10 and ET-DON versus ET-IVF: P < 0.05). In cows considered pregnant at 22 d but diagnosed open at 42 d, the interestrous intervals were 28.8 +/- 2.2, 35.2 +/- 3.5 and 31.6 +/- 2.9 d, respectively, for AI, ET-DON and ET-IVF groups. Transfer of embryos collected from nonheat-stressed superovulated donors significantly increased conception rates in heat stressed dairy cattle. However, transfer of IVF-derived embryos had no advantage over AI. Where appropriate mechanisms are in place to attenuate the effects of heat stress, embryo transfer using frozen-thawed donor embryos increases conception rates.

Animals↗