Ovarian Cysts in the Bitch: An Update

Advances in Vascular Diagnostics using Magnetic Particle Imaging (MPI) for Blood Circulation Assessment

Rapid and accurate assessment of conditions characterized by altered blood flow, cardiac blood pooling, or internal bleeding is crucial for diagnosing and treating various clinical conditions. While widely used imaging modalities such as magnetic resonance imaging (MRI), computed tomography (CT), and ultrasound offer unique diagnostic advantages, they fall short for specific indications due to limited penetration depth and prolonged acquisition times. Magnetic particle imaging (MPI), an emerging tracer-based technique, holds promise for blood circulation assessments, potentially overcoming existing limitations with reduction in background signals and high temporal and spatial resolution, below the millimeter scale. Successful imaging of blood pooling and impaired flow necessitates tracers with diverse circulation half-lives optimized for MPI signal generation. Recent MPI tracers show potential in imaging cardiovascular complications, vascular perforations, ischemia, and stroke. The impressive temporal resolution and penetration depth also position MPI as an excellent modality for real-time vessel perfusion imaging via functional MPI (fMPI). This review summarizes advancements in optimized MPI tracers for imaging blood circulation and analyzes the current state of pre-clinical applications. This work discusses perspectives on standardization required to transition MPI from a research endeavor to clinical implementation and explore additional clinical indications that may benefit from the unique capabilities of MPI.

Age at first birth, age at menopause, and risk of ovarian cyst: a two-sample Mendelian randomization study

Background

Increasing observational studies have indicated that hormonal reproductive factors were associated with ovarian cyst, a common gynecological disease. A two-sample Mendelian randomization (MR) was carried out by investigating the causality of reproductive factors including age at first birth (AFB), age at natural menopause (ANM), and age at menarche (AAM), and the risk of ovarian cyst (OC).

Method

Summary statistics were collected from a large genome-wide association study (GWAS), and we used a two-sample MR study to clarify the causal association between the exposure of AFB (N = 542,901), ANM (N = 69,360), and AAM (N = 29,346) and the outcome of the OC (N case = 20,750, N control = 107,564). We separately selected 51, 35, and 6 single-nucleotide polymorphisms (SNPs) as instrumental variables (IVs) for assaying the influence of AFB, ANM, and AAM on OC, respectively. Then, the causal relationship was tested through multiple approaches including an inverse-variance weighted method, an MR-Egger regression, and a weighted median method. In addition, the MR-PRESSO method was also used to verify the horizontal pleiotropy. Subsequently, we adjust the confounders for MR design.

Results

The MR analysis results showed that AFB was negatively associated with the OC (IVW Beta: -0.09, OR: 0.91, 95% CI: 0.86-0.96, p = 0.00185), and the greater AAM decreased the risk of OC (IVW Beta: -0.10, OR: 0.91, 95% CI: 0.82-0.99, p = 0.0376). However, ANM has a positive correlation with the OC (IVW Beta: 0.05, OR: 1.05, 95% CI: 1.03-1.08, p = 8.38 × 10-6). After adjusting BMI, alcohol intake frequency, and ever smoked, we also obtained a negative relationship between AFB and OC (p < 0.005). Meanwhile, we adjusted weight, alcohol intake frequency, and height, and then found a causal relationship between older AMN and an increased risk of OC (p < 0.005).

Conclusion

A causal effect of reproductive factors on the development of OC, affected by AFB, ANM, and AAM, was found convincingly. After adjusting the confounders, we also successfully found the substantial causal effect of younger AFB, younger AAM, and older ANM on an increased risk of OC.

Scientific and technical assistance on welfare aspects related to housing and health of cats and dogs in commercial breeding establishments

This Scientific Report addresses a mandate from the European Commission according to Article 31 of Regulation (EC) No 178/2002 on the welfare of cats and dogs in commercial breeding establishments kept for sport, hunting and companion purposes. The aim was to scrutinise recent recommendations made by the EU Platform on Animal Welfare Voluntary Initiative on measures to assist the preparation of policy options for the legal framework of commercial breeding of cats and dogs. Specifically, the main question addressed was if there is scientific evidence to support the measures for protection of cats and dogs in commercial breeding related to housing, health considerations and painful procedures. Three judgements were carried out based on scientific literature reviews and, where possible a review of national regulations. The first judgement addressed housing and included: type of accommodation, outdoor access, exercise, social behaviour, housing temperature and light requirements. The second judgement addressed health and included: age at first and last breeding, and breeding frequency. Judgement 3 addressed painful procedures (mutilations or convenience surgeries) and included: ear cropping, tail docking and vocal cord resections in dogs and declawing in cats. For each of these judgements, considerations were provided indicating where scientific literature is available to support recommendations on providing or avoiding specific housing, health or painful surgical interventions. Areas where evidence is lacking are indicated.

Expression and localization of the neuropeptide phoenixin-14 and its receptor GRP173 in the canine reproductive organs and periovarian adipose tissue

Phoenixin-14 (PNX-14) is a regulatory neuropeptide encoded by the SMIM20 gene, which has been implicated in the reproductive cycle by modulating the hypothalamic-pituitary-gonadal (HPG) axis. Recently, we showed that PNX-14 is downregulated in bitches with cystic endometrial hyperplasia and pyometra. The objective of this study was to determine the expression of Smim20, PNX-14, and its putative receptor GRP173 in the canine ovary (both healthy and those with ovarian cysts), periovarian adipose tissue (PAT) and in the endometrium during the oestrous cycle. The expression was analysed by RT-qPCR and Western blot. In tissue sections, peptides were localised by immunofluorescent assays, and blood plasma concentrations of PNX-14 were detected by EIA. The results demonstrated increased levels of PNX in bitches in the anestrus groups compared to diestrus animals. The expression of GPR173 increased in PAT during the diestrus phase and endometrial tissue in late diestrus bitches. In the ovary, strong signals of PNX-14 and GPR173 were detected in the luteal and follicular cells. Furthermore, bitches with cystic ovaries were characterised by elevated circulating PNX levels and a significantly higher expression of PNX and GPR173 in gonadal tissues, when compared with healthy animals. Moreover, a positive correlation between PNX and progesterone in the blood of healthy bitches was noted, which changed to a negative correlation in females affected by cystic ovaries. These studies expand the knowledge regarding the expression and localization of the PNX/GRP173 system in canine reproductive organs during physiological and pathological conditions.

Trends in Small Animal Reproduction: A Bibliometric Analysis of the Literature

Simple Summary

Reproduction in small animals is an expanding research area, with focus on breeding improvement and clinical management of domestic carnivores. The aim of the present study was to conduct a bibliometric analysis of the literature of the last decade on small animal reproduction, to point out main sources, most prolific countries, and emerging and neglected topics. Results show that research in biotechnologies for assisted reproduction has a central and increasing role in this field. Diversity in author keywords was also pointed out and a consensus to better categorize research in this field is proposed to reduce this problem in the future.

Abstract

Small animal reproduction (SAR) is a main research field in veterinary medicine and bibliometric analyses are useful to investigate trends in specific research areas. The objective of the present study was to conduct a bibliometric analysis of the literature of the last decade on SAR. A search equation was created, and documents were retrieved from the Web of Science database. Documents were manually revised, categorized and R software version 4.1.2 with Bibliometrix R package version 3.1 and MS Excel were used to perform the analyses. The included documents (n = 1470) were mainly research articles (78%). The top countries for the number of documents and citations were Brazil, United States, Italy, Poland, and Korea. These also account for the most prolific authors and institutions. Analyses by author keywords, categories, and recent reviews of the literature suggest that research on the canine species is more abundant than research on the feline one and that reproductive biotechnologies are a main research focus. Some clinical topics are still considered niche or neglected themes (e.g., semen collection in tomcats, neonatology). However, heterogeneity and ambiguity in keywords and categories are undeniable. This study offers interesting insights, providing definitions for main keywords in the field of SAR.

Ultrasonographic observation in combination with progesterone monitoring for detection of ovulation in Labrador Retrievers

Although it is well known that the ovulation occurs during a period of time after LH surge in dogs, there are few reports of observing the entire process of development, ovulation and luteinization of each follicle. This study aimed to detect the ovulation kinetics by ultrasonography in combination with progesterone monitoring and therefore identify the time-range of the ovulation process in a dog. Daily transabdominal ultrasonography and progesterone monitoring were conducted for 24 natural oestrus cycles of Labrador Retrievers. Ovarian follicles were observed as anechoic structure with contours before ovulation. Ovulation (follicular collapse) was defined as when follicles became cloudy and contours obscure by transabdominal ultrasonography. Ultrasound imaging was capable of identifying the day of ovulation for 94.7% (178/188) of the follicles through the appearance of collapsed follicle or corpus luteum. Ovulation was observed between LH 0 (the day of LH surge) and LH 5, with 48.0%, 33.5% and 15.0% for LH 2, LH 3 and LH 1, respectively. The total number of ovulations on LH 2 and LH 3 accounted for 81.5% (141/173) of the total ovulation in 24 cycles examined. Ovulation occurred in 12 cycles for 2 d and for 3 d in 12 cycles. Seventeen cycles (70.8%) with multiple days of ovulation showed the largest number of ovulations on LH 2. The average follicle diameter 3 d before the LH surge was less than 5 mm, then exceeded 5 mm 2 d before the LH surge. The average follicle diameter at the time of ovulation (follicular collapse) was 6.1 ± 1.0 mm (n = 118). On the day before ovulation, the average diameters of the follicles ovulated on LH 1, LH 2 and LH 3 were 5.0 ± 0.7 mm, 5.8 ± 1.2 mm and 6.2 ± 1.3 mm, respectively. There was a significant difference in the follicle diameter between LH1 and LH2 (p < .001), LH2 and LH3 (p < .05), and LH1 and LH3 (p < .001). Suggesting that it is difficult to estimate the ovulation day based on follicle size. This study showed that combination of ultrasonography with progesterone monitoring could follow follicular development, ovulation and luteinization of the ovary in Labrador Retrievers. The direct visualization of the ovulation was achieved in a non-invasive, labour-friendly way. Furthermore, the time-range of the ovulation process was clarified in a dog. These results may contribute to an accurate understanding of the optimum timing of mating and improved breeding efficiency, including artificial insemination and embryo transfer for Labrador Retrievers.