Sperm population structure in high and low field fertility rams.

The aim of the present study was to investigate whether differences in field fertility of rams are reflected in differences in sperm morphometric and kinematic population structures. The association between sperm morphometric and kinematic subpopulations was also investigated. Ejaculates from 8 adult rams, 4 with high and 4 with low field fertility, were collected weekly using an artificial vagina over 6 consecutive weeks. Analyses of sperm motility using computer-assisted sperm analysis (CASA) and sperm nuclear morphometry using computer-assisted sperm morphometry-fluorescence were performed. Clustering procedures using the kinematic and morphometric data from high and low field fertility rams resulted in the classification of spermatozoa in three kinematic and three morphometric sperm subpopulations. The distribution of subpopulations between rams of high and low field fertility was significantly different (P<0.05), with higher percentages of spermatozoa exhibiting fast and linear movements and those with large and long nuclei in the high fertility group. However, these subpopulations were not correlated. Logistic regression analyses were also performed to evaluate the relative utility of sperm subpopulations to classify rams in high and low field fertility. Total progressive sperm motility and the proportion of large and long spermatozoa were identified as the most consistent indicators of fertility. It was concluded that high and low fertility rams had clear differences in morphometric and kinematic sperm subpopulations, and that the most consistent indicators of fertility were the total progressive motility and the proportion of spermatozoa with large and long head present in the ejaculate.

Some factors affecting the abortion rate in dairy herds with high incidence of Neospora-associated abortions are different in cows and heifers.

The aim of this study was to determine if the factors affecting the abortion rate in dairy herds with high incidence of Neospora-associated abortions are different in pregnancies of cows and heifers chronically infected with Neospora caninum. In heifers (n = 229), an increase in the cumulative number of days with a mean relative humidity (RH) lower than 60% during the second trimester of gestation increases the risk of abortion. Yet, the likelihood of abortion was 7.6 times lower for pregnant heifers inseminated with Limousin bull semen, compared with those inseminated with Holstein-Friesian bull semen. In pregnancies of parous cows (n = 521), an increase in rainfall and in the cumulative number of days with a mean RH lower than 60% during the second trimester of gestation increased the abortion rate. However, in contrast, an increase in the lactation number produced a decrease in the abortion rate, with a likelihood of abortion 4.8 times lower for pregnant cows inseminated with Limousin bull semen, and three times lower for those inseminated with Belgian Blue bull semen, compared with dairy cows inseminated with Holstein-Friesian bull semen. Finally, the likelihood of abortion was 3.2 times lower for pregnancies of parous cows with low antibody titres against N. caninum (6-30 units) as compared to those with high antibody titres (>/=30 units), whereas in heifers this variable had no effect. The practical recommendations of the present study include the control of the cow environment during the second trimester of gestation, the priority of culling for parous cows with higher antibody titres against N. caninum and the insemination of Neospora-seropositive cows with semen from the Limousin breed.

Randomized double-blind, placebo-controlled trial of sublingual immunotherapy with a Pru p 3 quantified peach extract.

BACKGROUND: Peach allergy is highly prevalent in the Mediterranean area; it is persistent and potentially severe, and therefore a prime target for immunotherapy. We aimed to study the efficacy and safety of sublingual immunotherapy (SLIT) with a peach extract quantified in mass units for Pru p 3, the peach lipid transfer protein. METHODS: Randomized, double-blind, placebo-controlled (DBPC) clinical trial. The main efficacy outcome was the change in the response to a DBPC food challenge (DBPCFC) with peach. Secondary efficacy outcomes were the changes in skin prick test (SPT), and in specific immunoglobulin E (IgE) and IgG(4) to Pru p 3. Tolerance was assessed with a careful recording of adverse events. RESULTS: After 6 months of SLIT, the active group tolerated a significantly higher amount of peach (three- to ninefold), presented a significant decrease (5.3 times) in SPT, and a significant increase in IgE and IgG(4) to Pru p 3. No significant changes were observed within the placebo group. Statistically significant inter-group differences were only observed in the SPT and IgG(4) responses. No serious adverse events were reported. Systemic reactions were mild, and observed with a similar frequency in both groups. Local reactions were significantly more frequent in the active group (three times) and 95% of them restricted to the oral cavity. CONCLUSION: In this first exploratory clinical trial, SLIT for peach allergy seems to be a promising therapeutic option that could modify the clinical reactivity of the patients to peach intake and the underlying immunological response with a good tolerance.

Depletion of liver glutathione potentiates the oxidative stress and decreases nitric oxide synthesis in a rat endotoxin shock model.

OBJECTIVE: To verify the effects of liver glutathione depletion on redox status and nitric oxide system in a rat endotoxic shock model. DESIGN: Prospective, randomized, controlled study on rats. SETTING: A cardiocirculatory research laboratory. SUBJECTS: A total of 28 Sprague-Dawley male rats (200-250 g body weight) were divided into four experimental groups. INTERVENTIONS: Arterial blood, liver, and lung samples were taken from each animal under sodium pentobarbital (40 mg/kg i.p.) anesthesia 4 hrs after lipopolysaccharide (LPS group: 5 mg/kg i.p.; n = 7) or vehicle (control group: isotonic NaCl sterile solution i.p.; n = 7) treatments. Phorone (250 mg/kg i.p.) was injected to deplete glutathione in another two experimental groups of rats 30 mins before LPS (phorone+LPS group; n = 7) or vehicle (phorone group; n = 7) treatments, and 4 hrs later the same samples as in LPS and control groups were taken under anesthesia. MEASUREMENTS AND MAIN RESULTS: Compared with the control group, the LPS group presented higher plasma concentration of end products of nitric oxide metabolism nitrites/nitrates, higher lung activity of inducible nitric oxide synthase, and oxidative stress defined by increased plasma concentration of the lipid peroxides malonaldehyde and 4-hydroxynonenal, and decreased plasma total antioxidant capacity. Treatment with phorone depleted liver glutathione (80% to 90%). In the liver glutathione-depleted animals, the oxidative stress induced by LPS was potentiated and blunted the increases in inducible nitric oxide synthase and plasma nitrites/nitrates. CONCLUSION: These results show that depletion of the liver glutathione increases the oxidative stress and decreases nitric oxide synthesis of LPS-induced shock in rats.

Angiotensin II and retinal pericytes migration.

Angiotensin II (Ang II) appears to participate in the regulation of neovascularization processes in the retina. Migration of perimural cells such as pericytes plays a key role in regulation of angiogenesis. We hypothesize that Ang II stimulates migration of retina pericytes. For this we studied the effects of Ang II on migration of bovine retinal pericytes using modified Boyden chambers and collagen IV-covered polyester membranes. Ang II stimulated migration of pericytes by 54.8 +/- 9.7% (n = 10, p < 0.001). This effect was blocked by an AT(1) receptor antagonist (Losartan) but not by an AT(2) receptor antagonist (PD123319). We determined using checkerboard assays (n = 3) that Ang II induces migration of pericytes by chemotaxis (gradient-dependent), in opposition to chemokinesis (nondirected). Thus, Ang II via its AT(1) receptor acts as a chemotactic factor and stimulates migration of retina microvascular pericytes. This effect may contribute to Ang II-induced regulation of neovascularization processes in the retina.

Effect of changes in airway pressure on breathing pattern in conscious dogs.

The effect of brief (400 ms) or sustained (several breaths) application of positive or negative intrapulmonary air pressure was studied in three exercising conscious dogs. Changes in inspiratory duration (TI), expiratory duration (TE) and tidal volume (VT) were measured with the dogs' vagus nerves at body temperature and cooled to a temperature which abolished the Hering-Breuer inflation reflex (7 degrees C). Comparison of these results with those obtained with anaesthetized dogs leads us to suggest that there exists in conscious dogs a reflex inspiratory promoting drive.