Anomalous water dynamics in brain: a combined diffusion magnetic resonance imaging and neutron scattering investigation.

Water diffusion is an optimal tool for investigating the architecture of brain tissue on which modern medical diagnostic imaging techniques rely. However, intrinsic tissue heterogeneity causes systematic deviations from pure free-water diffusion behaviour. To date, numerous theoretical and empirical approaches have been proposed to explain the non-Gaussian profile of this process. The aim of this work is to shed light on the physics piloting water diffusion in brain tissue at the micrometre-to-atomic scale. Combined diffusion magnetic resonance imaging and first pioneering neutron scattering experiments on bovine brain tissue have been performed in order to probe diffusion distances up to macromolecular separation. The coexistence of free-like and confined water populations in brain tissue extracted from a bovine right hemisphere has been revealed at the micrometre and atomic scale. The results are relevant for improving the modelling of the physics driving intra- and extracellular water diffusion in brain, with evident benefit for the diffusion magnetic resonance imaging technique, nowadays widely used to diagnose, at the micrometre scale, brain diseases such as ischemia and tumours.

Use of the gonadotropin-releasing hormone (GnRH) stimulation test to monitor gonadal function in intact adult male cats.

The gonadotropin-releasing hormone (GnRH) stimulation test is a common procedure used to investigate normality of the pituitary-gonadal axis in mammals. There is very little information on the technique, its efficacy and side effects in small animals and in particular no information for male cats. In dogs, such test is performed by intravenous (IV) administration. With cats, the number of times the animal needs to be restrained for blood sampling should be the least possible. The purpose of this study was to assess efficacy and side effects of the GnRH stimulation test in tomcats comparing the IV with the intramuscular (IM) route of administration. A GnRH stimulation test was performed in eight adult tomcats through IM or IV administration of 50 µg gonadorelin. The response of the pituitary-gonadal axis was assessed by measuring serum testosterone on blood samples collected prior to and 1 hr following treatment. When considering each single group of cats, the post-stimulation serum testosterone values were significantly higher than the pre-treatment ones (p < .05). When comparing the two groups of cats, basal testosterone concentrations did not differ, and also post-GnRH testosterone concentrations did not differ. In conclusion, in the cats of our study, the GnRH stimulation test produced the same results following the IM or the IV route of administration. Therefore, in tomcats, the IM route can be considered as effective as the IV one and should be preferred when doing a GnRH test.

Biochemical and protein profile of alpaca (Vicugna pacos) uterine horn fluid during early pregnancy.

South American camelids show high embryo loss rate, during the first 60 days of pregnancy. One of the factors which may be related to this situation is that over 98% of the embryos implant in the left uterine horn (LUH) even though both ovaries contribute similarly to ovulation. There is scarce information about the uterine environment of female camelids at any physiological state that could explain the capability of the LUH to attract the embryo and maintain pregnancy. We describe, for the first time, the biochemical and protein profile of uterine fluid (UF), addressing the right and LUH environment in non-pregnant and pregnant alpacas. Different substrates, electrolytes and metabolites were assayed in both uterine horn fluids. Small changes were observed in glucose and total protein levels, which were more noticeable during pregnancy. In addition, 10 specific proteins were found in the left horn fluid in 5-week-pregnant alpacas, and two protein bands were identified in non-pregnant alpaca right horn fluid. These results would provide basic information for identification of possible markers for pregnancy diagnosis, reproductive diseases and hormone-treated animals evaluation and hence contributing to improve the pregnancy rate.

Integrated evaluation of scrotal temperature and testosteronemia after GnRH administration in young bulls with low semen production.

The aim of this study was to determine the suitability of thermographic monitoring of scrotal surface temperature (SST) as a method to monitor testicular function. Yearling bulls (n = 23) with low semen production were selected. Scrotal surface temperature and serum testosterone (T) concentrations were evaluated before and after administration of 10.5 µg buserelin acetate IV. Thermographic images of scrotum were recorded at 0, 15, 30, 45 and 60 min post-GnRH, while blood sampling was only performed at 60 min post-GnRH. Bulls were divided in two groups: LowTemp bulls (n = 10) had a decreased SST at 60 min; HighTemp bulls (n = 13) had an increased SST. After 60 min, LowTemp bulls had higher T concentrations compared to HighTemp bulls: 14.32 ng/ml ± 0.53 vs 10.30 ± 1.37 ng/ml (mean ± SEM; p < 0.05), respectively. Reproductive performances in both groups improved after GnRH administration, resulting in an increased number of inseminating doses from each collection, which was higher in LowTemp bulls. Pearson correlation test showed a negative relationship between T and SST (r = -0.554). In conclusion, a decreased scrotal surface temperature 60 min after GnRH treatment was associated with improved semen production.

Testicular cytology of alpaca: comparison between impressed and smeared slides.

Testicular fine needle aspiration (TFNA) has proven to be a simple and minimally invasive procedure, which allows assessments of cytological parameters of seminiferous epithelium/tubules more accurately in a short time. Though this technique does not cause negative effects on sperm quality or any damage to testicular tissue, its use is very limited in male animal infertility diagnostics. Report on the use of this technique in South American Camelids (SAC) is very limited. Therefore, the aim of this study was to evaluate the efficacy of TFNA for identification of different testicular cells and cell indices, and their correlation with that of impression cytology. A total of 98 slides were prepared from testes of six adult alpaca males, collected immediately after slaughter. Aspiration samples were performed by inserting a fine butterfly needle (21 G) connected to a 50 ml syringe into a testicle and multiple plane aspirations were carried out to obtain the materials destined to the smear. Three different imprints on slides were taken from each testicle. All slides were air-dried, stained with modified May--Grünwald--Giemsa (MGG) stain and then examined under light microscope with 1000× magnifications. Spermatogenic cells such as, spermatogonia (Sg), primary spermatocytes, secondary spermatocytes, early spermatids (ab), late spermatids (cd) and spermatozoa, and Sertoli cells were counted. The spermatozoa percentage was expressed as spermatic index (SI) and the number of Sertoli cells, counted apart, was expressed as sertoli cell index (SEI). There was not any significant difference between the spermatogenic cell parameters obtained from the two types of slides, but SEI were significantly different in two types of smears. The results of the study provide support for the use of TFNA as a useful minimally invasive modality to identify different spermatogenetic cell classes in alpaca. Moreover, the possibility to standardize this method might provide a greater impulse to the clinical diagnostics of SAC male infertility.

Clinical use of deslorelin for the control of reproduction in the bitch.

This study was conducted to evaluate clinical efficacy of deslorelin for inhibiting reproduction in the bitch. Ten adult healthy bitches or bitches with mammary neoplasia for which owners were requesting suppression of cyclicity without performing gonadectomy were administered a 4.7- or a 9.4-mg deslorelin implant subcutaneously. The first implant of deslorelin was administered in anoestrus (n = 5) or in dioestrus (n = 5). Treatment was repeated every 5 months for as long as necessary based on the clinical situation of the dog and owner's desires. Some of the bitches implanted in anoestrus came in heat within 4-15 days after treatment, while none of the bitches implanted in dioestrus showed heat during treatment. Suppression of reproductive cyclicity was successfully achieved in 6/10 bitches for 1-4 years. No behavioural and local/general side-effects were observed in any of the treated bitches. The 4.7-mg deslorelin implant may work well for suppression of cyclicity provided that it is administered in dioestrus and at intervals of 4.5 months. A 9.4-mg implant may be more suitable for this use although its efficacy may also be shorter than 12 months. Owner compliance is an important limiting factor.

Clinical use of testicular fine needle aspiration cytology in oligozoospermic and azoospermic dogs.

Clinical investigation of canine testicular function is complicated by the difficulty in the evaluation of seminiferous tubules. Until recently, testicular biopsy was the only diagnostic option for dogs with persistent oligo/azoospermia. In human andrology, testicular fine needle aspiration (TFNA) is currently considered a useful method in the evaluation of azoospermia and severe oligozoospermia, and has long replaced classical biopsy to evaluate spermatogenesis. In order to verify its diagnostic efficacy for the clinical approach to canine oligo- or azoospermia, TFNA was performed in seven adult (two oligozoospermic and five azoospermic) dogs. After sedation, a fine (21-23 gauge) butterfly needle connected to a 50-ml syringe was inserted into each testicle; strong suction was applied and the aspirated fluid squirted on a glass slide, smeared out, air-dried and stained with a modified May-Grunwald-Giemsa. Under light microscopy, Sertoli cells (all those found in each investigated field) and spermatogenic cells (n = 100) were counted on each smear in order to differentiate spermatogonia, primary spermatocytes, secondary spermatocytes, early spermatids, late spermatids and spermatozoa, and calculate their relative percentages. Cytological analysis showed the following testicular pictures: normal spermatogenesis (compatible with obstruction of the seminal ducts), hypospermatogenesis, maturative disturbances and Sertoli cell-only syndrome. Two dogs with an obstructive lesion were treated with corticosteroids; one of them recovered and sired two litters of puppies.