Vasectomy effect on canine seminal plasma biochemical components and their correlation with seminal parameters

Three semen samples were collected at 48 h intervals from 20 mature research dogs previously conditioned to manual semen collection. Vasectomy was performed in all dogs, and 15 days after surgery, another three ejaculates were similarly collected. The semen was evaluated, and centrifuged to obtain seminal plasma for measurement of pH, and concentrations of total proteins (TP), total chlorides (Cl), calcium (Ca), potassium (K), and sodium (Na). The seminal plasma protein profile was evaluated by SDS-PAGE; molecular weights and the integrated optical density (IOD) of each band were estimated. There was a negative correlation between K concentration and progressive motility (r = -0.49, P = 0.027), sperm vigor (r = -0.60, P = 0.0053), and plasma integrity, evaluated by both the hypo-osmotic swelling test (r = -0.50, P = 0.026) and a fluorescent stain (r = -0.45, P = 0.046). Positive correlations between Na and K pre- and post-vasectomy (r = 0.88, P < 0.001; r = 0.56, P < 0.01, respectively) were verified. There were a total of 37 bands pre-vasectomy and 35 post-vasectomy (range, 100.6-3.6 kDa). Bands B9 and B13 (42.6 and 29.2 kDa) were not present post-vasectomy. The IOD of band B3 (73.5 kDa) was higher (P = 0.03) pre-vasectomy, compared to post-vasectomy; conversely, the IODs of bands B29 and B37 (7.8 and 3.6 kDa) increased (P = 0.026 and 0.047). Pre-vasectomy, there was a positive correlation (r = 0.49, P = 0.029) between band B37 band (3.6 kDa) and the Na:K ratio. In conclusion, K appeared to be involved in sperm motility in dogs and could be a tool to evaluate sperm function. The prostate contributed several elements to canine seminal plasma. Vasectomy changed Ca concentrations and the protein profile of the seminal plasma. Further studies must be performed to clarify the function of these elements on the in vivo fertility of dogs.     

In vitro PGF2alpha production by endometrium and corpus luteum explants from pregnant and nonpregnant diestrus bitches and placental explants from pregnant bitches

To better understand the process of slow luteal regression of the nonpregnant cycle in dogs and the acute luteolysis that occurs prepartum, the present study investigated in vitro PGF2alpha production by the endometrium, corpus luteum and placental explants obtained at known times of the cycle from pregnant bitches (days 63, 64 and immediately postpartum; day 0 = estimated day of the ovulatory LH surge) and from nonpregnant diestrus bitches (approximately days 65, 75 and 85). Both basal PGF2alpha production and its production in the presence of the protein kinase C (PKC) stimulator 12,13-phorbol dibutyrate (PDBu) were determined. For PDBu-supplemented incubations, mean PGF2alpha production (pg/mL/mg/6 h) by endometrium explants of the nonpregnant bitches in late diestrus was highest on day 65 (205 +/- 87) and reduced to low levels (38 +/- 17 and 11 +/- 11) on days 75 and 85, respectively. The production by corpus luteum explants from these bitches was significantly less on day 65 (46 +/- 14) than that of the day 65 endometrium explants, and was slightly increased on day 85 (103 +/- 52). The corresponding mean PGF2alpha production by the endometrium explants of pregnant bitches was on average much greater (i.e., two to three-fold) compared to nonpregnant bitches (P < 0.01) and involved high concentrations at day 64 (1523 +/- 467) and postpartum, compared to somewhat lower levels on day 63 (830+/-65); luteal PGF production (165 +/- 4) was also higher than in nonpregnant bitches around day 65. For pregnant bitches, PGF production per gram of tissue in the endometrium explants was greater than for the CL or placenta explants (180 +/- 37). Therefore, the endometrium of the pregnant bitch has an increased capability to produce PGF2alpha immediately prepartum, which on a tissue weight basis, exceeds that of either corpora lutea or the placenta. However, assuming a larger mass of placental tissue in vivo, we inferred that the placenta may contribute substantially to peripheral PGF concentrations.     

Discrimination of Portuguese grapevines based on microsatellite markers

A set of 46 grapevine denominations was genotyped at 11 microsatellite loci in order to discriminate them. Ninety four alleles with a mean number of 8.55 alleles per locus were observed in a total of 37 detected unique genotypes. Previously assumed synonyms were confirmed and several cases of homonymy resolved. Comparison of the data obtained in this study with data of 32 genotypes previously reported enabled the detection of three parent offspring relationships, and identified other putative parent/progeny relationships. These data allowed understanding the origin of some Portuguese cultivars. The integration of the obtained data with ampelographic data would be very important for the accurate identification of the Portuguese cultivars and can become a significant tool for the certification of quality wines produced in specific regions.     

Studies toward the structural optimization of new brazilizone-related trypanocidal 1,3,4-thiadiazole-2-arylhydrazone derivatives

Megazol is a highly active compound against Trypanosoma cruzi, and has become a core structure for the design of new trypanocidal agents. Recently, we have identified the new potent trypanocide agent Brazilizone A, which presents an IC(50) twofold more potent than the prototype megazol. This result has encouraged us to further explore structurally-related 1,3,4-thiadiazole-2-arylhydrazone derivatives, in order to get a better understanding of their structural and antiprotozoal activity relationships. Herein we report the synthesis and trypanocidal profile of thirteen new Brazilizone A analogues, which supported the construction of 3D-QSAR models used for its structural optimization.     

Neuronal nitric oxide synthase-derived hydrogen peroxide is a major endothelium-dependent relaxing factor

Endothelium-dependent vasorelaxation in large vessels is mainly attributed to Nomega-nitro-L-arginine methyl ester (L-NAME)-sensitive endothelial nitric oxide (NO) synthase (eNOS)-derived NO production. Endothelium-derived hyperpolarizing factor (EDHF) is the component of endothelium-dependent relaxations that resists full blockade of NO synthases (NOS) and cyclooxygenases. H2O2 has been proposed as an EDHF in resistance vessels. In this work we propose that in mice aorta neuronal (n)NOS-derived H2O2 accounts for a large proportion of endothelium-dependent ACh-induced relaxation. In mice aorta rings, ACh-induced relaxation was inhibited by L-NAME and Nomega-nitro-L-arginine (L-NNA), two nonselective inhibitors of NOS, and attenuated by selective inhibition of nNOS with L-ArgNO2-L-Dbu-NH2 2TFA (L-ArgNO2-L-Dbu) and 1-(2-trifluoromethylphehyl)imidazole (TRIM). The relaxation induced by ACh was associated with enhanced H2O2 production in endothelial cells that was prevented by the addition of L-NAME, L-NNA, L-ArgNO2-L-Dbu, TRIM, and removal of the endothelium. The addition of catalase, an enzyme that degrades H2O2, reduced ACh-dependent relaxation and abolished ACh-induced H2O2 production. RT-PCR experiments showed the presence of mRNA for eNOS and nNOS but not inducible NOS in mice aorta. The constitutive expression of nNOS was confirmed by Western blot analysis in endothelium-containing vessels but not in endothelium-denuded vessels. Immunohistochemistry data confirmed the localization of nNOS in the vascular endothelium. Antisense knockdown of nNOS decreased both ACh-dependent relaxation and ACh-induced H2O2 production. Antisense knockdown of eNOS decreased ACh-induced relaxation but not H2O2 production. Residual relaxation in eNOS knockdown mouse aorta was further inhibited by the selective inhibition of nNOS with L-ArgNO2-L-Dbu. In conclusion, these results show that nNOS is constitutively expressed in the endothelium of mouse aorta and that nNOS-derived H2O2 is a major endothelium-dependent relaxing factor. Hence, in the mouse aorta, the effects of nonselective NOS inhibitors cannot be solely ascribed to NO release and action without considering the coparticipation of H2O2 in mediating vasodilatation.     

Trace elements in human milk: Correlation with blood levels, inter-element correlations and changes in concentration during the first month of lactation

Using inductively coupled plasma mass spectrometry (ICP-MS) based analytical procedures, the concentration of several trace elements (Mn, As, Pb, Co, Ni, Cu, Zn and Se) was determined in human milk samples collected from a group of healthy lactating Portuguese women (n=44), both on the 2nd day postpartum (i.e., colostrum; n=34) and at 1 month postpartum (i.e., mature milk; n=19). Blood samples (n=44), collected on the 2nd day after parturition, were also analyzed for the same trace elements. No major correlations were observed between the levels of the analyzed trace elements in blood and colostrum samples. All the studied elements, except for Co, Pb and Ni, showed a significant trend for a decrease in concentration in milk during the first month of lactation. This trend was more pronounced for Zn and Se, whose levels decreased to approximately 23% and 44% of their initial mean concentration, respectively. With the exception of Co (r=0.607) and Zn (r=0.487), no significant correlations were observed when comparing the levels of each trace element between samples of colostrum and mature milk. Several inter-element correlations were found within each type of milk sample. The most significant were: (i) Se vs Cu (r=0.828) and Se vs Co (r=0.605) in colostrum samples and (ii) Ni vs Pb (r=0.756), Ni vs Mn (r=0.743) and Se vs Co (r=0.714) in mature milk samples. An inverse correlation between Zn and Se was also found in both types of milk sample; however, it only reached statistical significance for mature milk (r=-0.624).     

Is Intracranial Atherosclerosis an Independent Risk Factor for Cerebral Atrophy? A Retrospective Evaluation

Background

Our purpose was to study the association between the intracranial atherosclerosis as measured by cavernous carotid artery calcification (ICAC) observed on head CT and atrophic changes of supra-tentorial brain demonstrated by MRI.

Methods

Institutional review board approval was obtained for this retrospective study incorporating 65 consecutive patients presenting acutely who had both head CT and MRI. Arterial calcifications of the intracranial cavernous carotids (ICAC) were assigned a number (1 to 4) in the bone window images from CT scans. These 4 groups were then combined into high (grades 3 and 4) and low calcium (grades 1 and 2) subgroups. Brain MRI was independently evaluated to identify cortical and central atrophy. Demographics and cardiovascular risk factors were evaluated in subjects with high and low ICAC. Relationship between CT demonstrated ICAC and brain atrophy patterns were evaluated both without and with adjustment for cerebral ischemic scores and cardiovascular risk factors.

Results

Forty-six of the 65 (71%) patients had high ICAC on head CT. Subjects with high ICAC were older, and had higher prevalence of hypertension, diabetes, coronary artery disease (CAD), atrial fibrillation and history of previous stroke (CVA) compared to those with low ICAC. Age demonstrated strong correlation with both supratentorial atrophy patterns. There was no correlation between ICAC and cortical atrophy. There was correlation however between central atrophy and ICAC. This persisted even after adjustment for age.

Conclusion

Age is the most important determinant of atrophic cerebral changes. However, high ICAC demonstrated age independent association with central atrophy.