Comparing ovarian expression of sperm acrosome associated 3 protein in young and adult queens

The purpose of this research was to quantify sperm acrosome associated 3 protein expression in the ovaries of young (3.0 ± 0.9 months, n = 11) and adult (10.4 ± 2.8 months, n = 11) queens. Immunohistochemistry was performed on formalin-fixed, paraffin-embedded feline ovarian sections. Ovaries were obtained following routine ovariohysterectomy of queens. Cellular expression of sperm acrosome associated 3 protein was measured in primordial, primary, secondary, and tertiary follicles using an image-analysis software's red, green, and blue stack and manual thresholding functions. The oocyte nucleus, ooplasm, granulosa cells, and theca cells were outlined using the freehand selection tool and mean grey value was recorded. Results from each cellular location were compared between age groups using a Student's t-test and between follicle stages using an analysis of variance. Compared to adult queens, younger queens had significantly greater sperm acrosome associated 3 protein expression in granulosa cells of primary, secondary, and tertiary follicles. Also, theca cells of secondary and tertiary follicles had significantly greater sperm acrosome associated 3 protein expression in younger queens compared to adult queens. The oocyte nucleus of primordial, primary, and secondary follicles had significantly greater sperm acrosome associated 3 protein expression in younger queens compared to adult queens. However, sperm acrosome associated 3 protein expression within the ooplasm did not differ significantly between age groups of any follicle type. More research is needed to determine what role sperm acrosome associated 3 protein may play in female fertility in animals as well as what mechanisms regulate ovarian sperm acrosome associated 3 protein expression over time.

Developing a modified Apgar scoring system for newborn lambs

The Apgar (appearance, pulse, grimace, attitude, respiration) score is an accepted method for assessing newborn viability in humans and domestic animals. The purpose of this research was to modify an existing Apgar scoring system for lambs and compare Apgar score with litter size and birth order, as well as time-to-stand and time-to-suckle. Polypay lambs (n = 75) delivered naturally were used for this study. Pulse (<100 bpm = 0; 100-175 bpm = 1; >175 bpm = 2) and respiration (<45% SpO₂ = 0; 45-65% SpO₂ = 1; >65% SpO₂ = 2) were measured with a pulse oximeter attached to the lamb's ear. Appearance, grimace, and attitude were assessed using mucous membrane color (cyanotic = 0; pale = 1; pink = 2); response to nose stimulation (no response = 0; moves head slightly = 1; shakes head = 2); and response to rump stimulation (no movement = 0; moves but no attempt to stand = 1; attempts to stand = 2), respectively. The Apgar score was measured within 5 min of birth (T0), 15 min (T15) and 60 min (T60) after birth. The time-to-stand and time-to-suckle were recorded and compared to Apgar scores. Apgar scores did not differ by litter size or birth order. There were no significant correlations between the Apgar scores and time-to-stand. There was a moderate positive correlation between attitude and time-to-suckle at T0 (R² = 0.467), which may affect the ingestion of adequate colostrum in a timely manner. Producers may choose to consider using Apgar scoring so that assistance can be provided to lambs before serious complications arise.

Cow milk does not affect adiposity in growing piglets as a model for children

The effect of milk consumption on childhood obesity is unclear and a direct demonstration of an association is needed. In the present study, we used piglets as a model for prepubertal children to determine the effect of milk on adipose tissue. Two studies were conducted: study 1 with 5-wk-old male piglets (n = 8) and study 2 with 8- to 9-wk-old male piglets (n = 12). The piglets were fed a normal growing diet and randomly assigned to receive daily either 750 mL of whole cow milk or an isocaloric maltodextrin solution (control). For approximately 12 wk, body weight, feed intake, and subcutaneous back fat thickness were determined ultrasonographically and recorded. At euthanasia, back and neck fat thicknesses were measured and samples of back fat were collected for adipose histology. In study 1, but not study 2, piglets receiving milk grew more and ate more compared with control. In study 1, both back fat and neck fat thickness were greater in the milk-fed piglets and they had a higher frequency of small adipocytes and a lower frequency of intermediate and large adipocytes compared with controls. In study 2, control pigs had a significantly greater frequency of intermediate adipocytes but the milk-fed piglets tended to have a higher frequency of the largest adipocytes. In conclusion, milk has no apparent causal or consistent effect on adipose tissue in growing piglets.

Acupuncture prevents the postpartum reduction in matrix metalloproteinase type-2 immunoexpression, tissue concentration and enzyme activity in bovine caruncles

The objectives of this study were to determine the effects of acupuncture in dairy cows (Bos taurus) on caruncular matrix metalloproteinase type-2 (MMP2) at 0, 2 and 4 hr after calving. Acupuncture (n = 6) was applied at 0 and 2 hr after calving to 6 points that relax the cervix and stimulate uterine contractions. Controls (n = 9) were kept in a stanchion for 15 min without acupuncture. All of the cows in the study delivered their placenta in <4 hr. Formalin-fixed caruncles were paraffin-embedded and subjected to routine immunohistochemistry to determine MMP2 expression, which was scored by a single observer. Flash frozen caruncles were homogenized, and protein concentration was determined. MMP2 concentrations were calculated using commercial bovine ELISAs. MMP2 enzyme activity was determined using zymography. The mean value for each time point for each cow was used to calculate the mean ± SEM for each treatment group. MMP2 was predominantly localized to the epithelial and subepithelial stromal cells of the caruncles in both treatment groups. MMP2 immunoexpression was lower 4 hr after calving in the control cows (p = 0.012) but not in the acupuncture treated cows indicating that acupuncture treatment maintained MMP expression. MMP2 tissue concentration was lower 2 hr after calving in the control cows (p = 0.048) but not in the acupuncture treated cows. MMP2 enzyme activity decreased from 0 to 2 hr after calving in control cows (p = 0.046) but not in acupuncture treated cows. This study provides physiologic evidence for the effects of acupuncture on the bovine reproductive tract and substantiates the use of this treatment in cases of placental retention.

Hyperandrogenism from an Ovarian Interstitial-Cell Tumor in an Alpaca

An 8-year-old intact female Huacaya alpaca ( Lama pacos) was presented for recent development of male behavior. Serum testosterone concentration was determined to be 969.1 pg/ml by using radioimmunoassay, while the range in 33 healthy female adult intact alpacas was 11.7–62.1 pg/ml. An ovarian mass was suspected, and an exploratory laparotomy was performed. A tan mass was present on the left ovary. Histologically, the mass was composed of closely packed, plump, polygonal cells with central round nuclei with granular chromatin and abundant eosinophilic finely granular to vesiculate cytoplasm. An ovarian benign interstitial (Leydig) cell tumor was diagnosed.

Cellular characteristics of cultured canine trophoblasts

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Shallow trophoblast invasion is detrimental in human pregnancies, but represents normal endotheliochorial placentation in dogs. Factors regulating shallow trophoblast invasion into the canine decidua are not well described, but it is known that matrix metalloproteinases (MMPs) play a crucial role in trophoblast invasion in many species. Following the methods previously described for isolating human trophoblasts, canine trophoblasts were isolated using collagenase and trypsin digestions with Percoll density gradient centrifugation. In addition, placental pieces were cryopreserved prior to primary culture following methods previously described for human tissue. Expression of cytokeratin-7, MMP2 and MMP9 was confirmed using fluorescent immunocytochemistry. Cellular morphology was similar to that reported for trophoblasts. More than 97% of the cells cultured expressed cytokeratin-7. More cultured canine trophoblasts expressed MMP9 (54.7 ± 3.4%) compared with MMP2 (40.3 ± 1.8%) (p = 0.02). Although both MMPs were immunolocalized to the cytoplasm, MMP2 was found in large, coalescing granules, whereas MMP9 was more diffusely expressed throughout the cell. Cryogenic freezing of placental tissue prior to primary cell culture had no effect on cell proliferation (p = 0.37). This research has established a baseline for future studies investigating the canine placenta as a model for disorders of shallow trophoblast invasion in humans.

Generation and characterization of phage-GnRH chemical conjugates for potential use in cat and dog immunocontraception

Overpopulation of cats and dogs is a serious worldwide problem that demands novel, safe and cost-effective solutions. The objective of this study was to generate and characterize phage-peptide conjugates with gonadotropin-releasing hormone (GnRH) for potential use as an immunocontraceptive. A filamentous phage vector f5-8 with wild-type phage coat proteins was used as a carrier for construction of chemical conjugates with GnRH, a peptide that acts as a master reproductive hormone. In such conjugates, the phage body plays the role of a carrier protein, while multiple copies of GnRH peptide stimulate production of neutralizing anti-GnRH antibodies potentially leading to contraceptive effects. To generate the constructs, four different GnRH-based peptides were synthesized and conjugated to phage particles in a two-step procedure: (i) peptides were reacted with phage to form a conjugate using 1-ethyl-3-[3-dimethylaminopropyl]carbodiimide hydrochloride chemistry (EDC) and (ii) the conjugates were separated from remaining free peptides by dialysis. Formation and specificity of phage-GnRH conjugates were confirmed by three independent methods: spectrophotometry, electron microscopy and ELISA. When the conjugates were tested for interaction with sera collected from cats and dogs immunized with GnRH-based vaccines in independent studies, strong specific ELISA signals were obtained, suggesting the potential use of the conjugates for cat and dog immunosterilization. The ability of the conjugates to stimulate production of anti-GnRH antibodies in vivo was evaluated in mice. While optimization of dose, immunization route and adjuvant still requires investigation, our preliminary results demonstrated the presence of anti-GnRH antibodies in sera of mice immunized with such conjugates. Fertility trials in cats and dogs will be needed to evaluate contraceptive potentials of the phage-GnRH peptide chemical conjugates.

Development and application of camelid molecular cytogenetic tools

Cytogenetic chromosome maps offer molecular tools for genome analysis and clinical cytogenetics and are of particular importance for species with difficult karyotypes, such as camelids (2n = 74). Building on the available human-camel zoo-fluorescence in situ hybridization (FISH) data, we developed the first cytogenetic map for the alpaca (Lama pacos, LPA) genome by isolating and identifying 151 alpaca bacterial artificial chromosome (BAC) clones corresponding to 44 specific genes. The genes were mapped by FISH to 31 alpaca autosomes and the sex chromosomes; 11 chromosomes had 2 markers, which were ordered by dual-color FISH. The STS gene mapped to Xpter/Ypter, demarcating the pseudoautosomal region, whereas no markers were assigned to chromosomes 14, 21, 22, 28, and 36. The chromosome-specific markers were applied in clinical cytogenetics to identify LPA20, the major histocompatibility complex (MHC)-carrying chromosome, as a part of an autosomal translocation in a sterile male llama (Lama glama, LGL; 2n = 73,XY). FISH with LPAX BACs and LPA36 paints, as well as comparative genomic hybridization, were also used to investigate the origin of the minute chromosome, an abnormally small LPA36 in infertile female alpacas. This collection of cytogenetically mapped markers represents a new tool for camelid clinical cytogenetics and has applications for the improvement of the alpaca genome map and sequence assembly.

Ovarian dysgenesis in an alpaca with a minute chromosome 36

A 4-year-old female alpaca (Lama pacos [LPA]) was presented to the Oregon State Veterinary Teaching Hospital for failure to display receptive behavior to males. Although no abnormalities were found on physical examination, transrectal ultrasonographic examination of the reproductive tract revealed uterine hypoplasia and ovarian dysgenesis. Cytogenetic analysis demonstrated a normal female 74,XX karyotype with 1 exceptionally small (minute) homologue of autosome LPA36. Chromosome analysis by Giemsa staining and DAPI- and C-banding revealed that the minute LPA36 was submetacentric, AT-rich, and largely heterochromatic. Because of the small size and lack of molecular markers, it was not possible to identify the origin of the minute. There is a need to improve molecular cytogenetic tools to further study the phenomenon of this minute chromosome and its relation to female reproduction in alpacas and llamas.

Determination of testicular blood flow in camelids using vascular casting and color pulsed-wave Doppler ultrasonography

We describe the vasculature of the camelid testis using plastic casting. We also use color pulsed-wave Doppler ultrasonography to measure testicular blood flow and compare the differences between testicular blood flow in fertile and infertile camelids. The testicular artery originates from the ventral surface of the aorta, gives rise to an epididymal branch, and becomes very tortuous as it approaches the testis. Within the supratesticular arteries, peak systolic velocity (PSV) was higher in fertile males compared to infertile males (P = 0.0004). In addition, end diastolic velocity (EDV) within the supratesticular arteries was higher for fertile males when compared to infertile males (P = 0.0325). Within the marginal arteries, PSV was also higher in fertile males compared to infertile males (P = 0.0104). However, EDV within the marginal arteries was not significantly different between fertile and infertile males (P = 0.121). In addition, the resistance index was not significantly different between fertile and infertile males within the supratesticular (P = 0.486) and marginal arteries (P = 0.144). The significance of this research is that in addition to information obtained from a complete reproductive evaluation, a male camelid's fertility can be determined using testicular blood flow measured by Doppler ultrasonography.

Non-surgical methods of contraception and sterilization

The Humane Society of the United States estimates that each year between 8 and 10 million dogs and cats enter shelters and 4-5 million of these animals are euthanized due to lack of homes. Many veterinarians within the United States recommend surgical sterilization for population control in dogs and cats. However, there are non-surgical methods to control reproduction. Pharmacologic methods of contraception and sterilization can be safe, reliable and reversible. Hormonal treatments using progestins, androgens, or gonadotropin releasing hormone (GnRH) analogs act to either directly block reproductive hormone receptor-mediated events, or indirectly block conception via negative feedback mechanisms. Immunocontraception, via vaccination against GnRH, the luteinizing hormone receptor or zona pellucida proteins, is also possible. Intratesticular or intraepididymal injections provide a method for non-surgical sterilization of the male dog and cat. Additional methods have been employed for mechanical disruption of fertility including intravaginal and intrauterine devices and ultrasound testicular ablation. Alternative approaches to surgical sterilization will be reviewed.