Former Undersecretary of Institutional Evaluation, Ministry of Science, Technology and Innovation, Argentina Former Vice Dean Veterinary Sciences Faculty, Buenos Aires University / Chair of Biophysics - Director of Seminal Quality and Gamete Cryopreservation Lab
... or even a sow in oestrus is not always feasible under field conditions, particularly when the... more ... or even a sow in oestrus is not always feasible under field conditions, particularly when the subject is a mature, intractable boar (Fraser 1971). ... to the animals in two phases: first, xylazine (Sedomin 10 per cent; Konig) and diazepam (Diazepan 5 mg/ml; Lamar) were administered ...
En la cátedra de Física Biológica de la Facultad de Ciencias Veterinarias de la UBA se desarrolla... more En la cátedra de Física Biológica de la Facultad de Ciencias Veterinarias de la UBA se desarrollaron estrategias táctiles para estudiantes con discapacidad visual, para que pudieran conceptualizar los conceptos de dilución y homogeneidad de una suspensión acuosa de partículas. Asimismo se diseñaron estrategias táctiles para que pudieran comprender cómo se cuentan células mediante el uso del microscopio. Otro objetivo fue comprender la utilización de gráficos de ejes cartesianos x-y, a partir de valores experimentales conocidos de dos variables, para poder obtener un valor desconocido.
Información del artículo Dirección de centros de inseminación artificial porcina (3ª parte): bios... more Información del artículo Dirección de centros de inseminación artificial porcina (3ª parte): bioseguridad, bienestar animal y medio ambiente.
All in-text references underlined in blue are linked to publications on ResearchGate, letting you... more All in-text references underlined in blue are linked to publications on ResearchGate, letting you access and read them immediately.
Increased protein tyrosine phosphorylation and the appearance of a phosphorylated protein of 32 k... more Increased protein tyrosine phosphorylation and the appearance of a phosphorylated protein of 32 kD (p32) are reported among the capacitation-like changes in cryopreserved boar sperm. Egg yolk freezing extenders are composed by two fractions: insoluble granules and soluble plasma, which contains the low density lipoproteins (LDL) proposed as responsible for the egg yolk cryoprotective action. The aim of this work was to analyze the effects of complete egg yolk and its insoluble, soluble and LDL fractions on boar sperm quality and protein tyrosine phosphorylation after the first stage of a standard cryopreservation protocol. Semen samples in Androstar Plus diluent were centrifuged and resuspended in the different egg yolk extenders. Temperature was decreased from 17 °C to 5 °C and sperm quality, protein tyrosine phosphorylation and protein pattern were analyzed. Results showed that complete egg yolk as well as soluble and LDL egg yolk fractions maintained sperm quality after temperatu...
The aim of the present study was to perform a qualitative and quantitative analysis of the effect... more The aim of the present study was to perform a qualitative and quantitative analysis of the effect of different sucrose concentrations combined with ethylene glycol in the preservation of vitrified porcine preantral follicles. Fragments of ovarian cortex were vitrified in cryotubes containing 200 μl of the vitrification solution (30% Ethylene Glycol; 20% Fetal Bovine Serum; 0 M-0.25 M - 0.75 M or 1 M sucrose) and stored in liquid nitrogen for a week. Histological analysis showed that after vitrification the number of normal follicles decreased compared to the fresh tissue (control). The percentage of normal primordial follicles was sucrose dose dependent. The percentage of normal primary follicles was similar in 0 M or 0.25 M sucrose, while higher concentrations (0.75 M and 1 M) increased significantly the percentage of abnormal follicles (p < 0.05). Morphometric analysis showed a statistically significant reduction in the total area of primordial follicles with 0.75 M sucrose and...
The aim of the present study was to perform a qualitative and quantitative analysis of the effect... more The aim of the present study was to perform a qualitative and quantitative analysis of the effect of different sucrose concentrations combined with ethylene glycol in the preservation of vitrified porcine preantral follicles. Fragments of ovarian cortex were vitrified in cryotubes containing 200 μl of the vitrification solution (30% Ethylene Glycol; 20% Fetal Bovine Serum; 0 M-0.25 M - 0.75 M or 1 M sucrose) and stored in liquid nitrogen for a week. Histological analysis showed that after vitrification the number of normal follicles decreased compared to the fresh tissue (control). The percentage of normal primordial follicles was sucrose dose dependent. The percentage of normal primary follicles was similar in 0 M or 0.25 M sucrose, while higher concentrations (0.75 M and 1 M) increased significantly the percentage of abnormal follicles (p < 0.05). Morphometric analysis showed a statistically significant reduction in the total area of primordial follicles with 0.75 M sucrose and...
The aim of the present study was to perform a qualitative and quantitative analysis of the effect... more The aim of the present study was to perform a qualitative and quantitative analysis of the effect of different sucrose concentrations combined with ethylene glycol in the preservation of vitrified porcine preantral follicles. Fragments of ovarian cortex were vitrified in cryotubes containing 200 ml of the vitrification solution (30% Ethylene Glycol; 20% Fetal Bovine Serum; 0 Me0.25 M e 0.75 M or 1 M su-crose) and stored in liquid nitrogen for a week. Histological analysis showed that after vitrification the number of normal follicles decreased compared to the fresh tissue (control). The percentage of normal primordial follicles was sucrose dose dependent. The percentage of normal primary follicles was similar in 0 M or 0.25 M sucrose, while higher concentrations (0.75 M and 1 M) increased significantly the percentage of abnormal follicles (p < 0.05). Morphometric analysis showed a statistically significant reduction in the total area of primordial follicles with 0.75 M sucrose and a significant increase in the cytoplasmic area of primordial follicles with 0 M sucrose (p < 0.05). The qualitative and the quantitative analysis appear to be a complementary tool when choosing a vitrification protocol. For our cryopres-ervation system-vitrification of ovarian cortex slices in cryotubes-the best vitrification medium was TCM 199-Hepes with 30% de ethylene glycol, 20% of Fetal Bovine Serum and 0 or 0.25 M sucrose. The present study shows that the use of high sucrose concentrations in the vitrification solution has a deleterious effect on the preservation of porcine preantral follicles contained in ovarian tissue. Consequently , its use at 0.75 M or 1 M wouldn't be recommended.
The objectives of this study were as follows: (i) to describe and evaluate the frequencies of dif... more The objectives of this study were as follows: (i) to describe and evaluate the frequencies of different morphologies of llama sperm nuclei, (ii) to determine morphometric values of nuclear parameters, (iii) to describe and estimate the frequencies of different classes of chromatin distribution and (iv) to measure haploid DNA content and analyse its nuclear distribution. The study was performed using ejaculates collected from seven males, and sperm nuclei were stained with the Feulgen reaction. Normal morphology ranged from 78.36% to 93.92%, and abnormalities included short, small, large, pyriform, narrow, micro and round nuclei. Important differences in nuclei considered normal were found between some males. The following average values were obtained for each sperm nuclear morphometric parameter analysed: area 11.64 μm2, perimeter 13.16 μm, length 5.12 μm, width 2.81 μm, ellipticity 1.85 and form 0.83. Differences between males were significant for all the parameters (p < .01). Light microscope observations and cytophotometric determinations allowed discriminating between three classes of chromatin distribution: homogeneous, diffuse and showing a clear band. Significant differences between males were found for the frequencies of the three classes (p < .01). Cluster analysis methods were used to estimate the resemblance between males according to the characteristics of their sperm nuclei. A great intermale variability was found for morphological, morphometric and chromatin distribution data. These parameters would have low dependence between them.
Sperm &#39;tail stump&#39; defect was found in ejaculates of a wild boar maintained in ca... more Sperm &#39;tail stump&#39; defect was found in ejaculates of a wild boar maintained in captivity. It was in good physical condition, the testes and genital tract were found to be of normal size and consistency. There was no evidence of macroscopic abnormalities at the clinical analysis and at necropsy. The volume and concentration of the semen samples obtained by electroejaculation were lower than normal. The slides examined contained a high level of abnormal spermatozoa (52.7%). The most frequent morphological finding was a droplet-like form attached to the base of the head or a very short stump. The non-stumped spermatozoa had no normal tail but a shortened one. Analysing the histological structure with light microscopy, no ring of spermatozoa was observed lining the lumen of the seminiferous tubules and the characteristically cellular structure was not conserved. The ultrastructural examination evidenced a disorganisation of the normal tubular structure of the flagellum, with lost of regular pattern of the axial bundle of fibrils and the mitochondrial helix. The origin of this abnormality is unknown.
The aim of this study was to describe the morphology, morphometry and determine the DNA content o... more The aim of this study was to describe the morphology, morphometry and determine the DNA content of yak sperm nuclei (Bos grunniens). Nuclear morphology observations were performed using light microscopy on slides stained with Feulgen reaction. Abnormalities percentages were determined: pyriform (1.2%), globose (0.2%), small (0.2%), elongated (0.1%). Morphometric measurements were made from digitized images of sperm nuclei stained with the Feulgen reaction. Mean values and standard deviations were obtained: area 21.98 ± 2.60 μm2, length 7.34 ± 0.33 μm, width 3.78 ± 0.27 μm, perimeter 88 ± 19.26 μm, roundness 1.27 ± 0.04, elongation 1.95 ± 0.11 and equivalent diameter 5.28 ± 0.27 μm. According to our knowledge this is the first time that haploid DNA content is determined. In this species 3.42 pg value that was similar to that measured in other species of the family Bovidae and other higher mammals.
... or even a sow in oestrus is not always feasible under field conditions, particularly when the... more ... or even a sow in oestrus is not always feasible under field conditions, particularly when the subject is a mature, intractable boar (Fraser 1971). ... to the animals in two phases: first, xylazine (Sedomin 10 per cent; Konig) and diazepam (Diazepan 5 mg/ml; Lamar) were administered ...
En la cátedra de Física Biológica de la Facultad de Ciencias Veterinarias de la UBA se desarrolla... more En la cátedra de Física Biológica de la Facultad de Ciencias Veterinarias de la UBA se desarrollaron estrategias táctiles para estudiantes con discapacidad visual, para que pudieran conceptualizar los conceptos de dilución y homogeneidad de una suspensión acuosa de partículas. Asimismo se diseñaron estrategias táctiles para que pudieran comprender cómo se cuentan células mediante el uso del microscopio. Otro objetivo fue comprender la utilización de gráficos de ejes cartesianos x-y, a partir de valores experimentales conocidos de dos variables, para poder obtener un valor desconocido.
Información del artículo Dirección de centros de inseminación artificial porcina (3ª parte): bios... more Información del artículo Dirección de centros de inseminación artificial porcina (3ª parte): bioseguridad, bienestar animal y medio ambiente.
All in-text references underlined in blue are linked to publications on ResearchGate, letting you... more All in-text references underlined in blue are linked to publications on ResearchGate, letting you access and read them immediately.
Increased protein tyrosine phosphorylation and the appearance of a phosphorylated protein of 32 k... more Increased protein tyrosine phosphorylation and the appearance of a phosphorylated protein of 32 kD (p32) are reported among the capacitation-like changes in cryopreserved boar sperm. Egg yolk freezing extenders are composed by two fractions: insoluble granules and soluble plasma, which contains the low density lipoproteins (LDL) proposed as responsible for the egg yolk cryoprotective action. The aim of this work was to analyze the effects of complete egg yolk and its insoluble, soluble and LDL fractions on boar sperm quality and protein tyrosine phosphorylation after the first stage of a standard cryopreservation protocol. Semen samples in Androstar Plus diluent were centrifuged and resuspended in the different egg yolk extenders. Temperature was decreased from 17 °C to 5 °C and sperm quality, protein tyrosine phosphorylation and protein pattern were analyzed. Results showed that complete egg yolk as well as soluble and LDL egg yolk fractions maintained sperm quality after temperatu...
The aim of the present study was to perform a qualitative and quantitative analysis of the effect... more The aim of the present study was to perform a qualitative and quantitative analysis of the effect of different sucrose concentrations combined with ethylene glycol in the preservation of vitrified porcine preantral follicles. Fragments of ovarian cortex were vitrified in cryotubes containing 200 μl of the vitrification solution (30% Ethylene Glycol; 20% Fetal Bovine Serum; 0 M-0.25 M - 0.75 M or 1 M sucrose) and stored in liquid nitrogen for a week. Histological analysis showed that after vitrification the number of normal follicles decreased compared to the fresh tissue (control). The percentage of normal primordial follicles was sucrose dose dependent. The percentage of normal primary follicles was similar in 0 M or 0.25 M sucrose, while higher concentrations (0.75 M and 1 M) increased significantly the percentage of abnormal follicles (p < 0.05). Morphometric analysis showed a statistically significant reduction in the total area of primordial follicles with 0.75 M sucrose and...
The aim of the present study was to perform a qualitative and quantitative analysis of the effect... more The aim of the present study was to perform a qualitative and quantitative analysis of the effect of different sucrose concentrations combined with ethylene glycol in the preservation of vitrified porcine preantral follicles. Fragments of ovarian cortex were vitrified in cryotubes containing 200 μl of the vitrification solution (30% Ethylene Glycol; 20% Fetal Bovine Serum; 0 M-0.25 M - 0.75 M or 1 M sucrose) and stored in liquid nitrogen for a week. Histological analysis showed that after vitrification the number of normal follicles decreased compared to the fresh tissue (control). The percentage of normal primordial follicles was sucrose dose dependent. The percentage of normal primary follicles was similar in 0 M or 0.25 M sucrose, while higher concentrations (0.75 M and 1 M) increased significantly the percentage of abnormal follicles (p < 0.05). Morphometric analysis showed a statistically significant reduction in the total area of primordial follicles with 0.75 M sucrose and...
The aim of the present study was to perform a qualitative and quantitative analysis of the effect... more The aim of the present study was to perform a qualitative and quantitative analysis of the effect of different sucrose concentrations combined with ethylene glycol in the preservation of vitrified porcine preantral follicles. Fragments of ovarian cortex were vitrified in cryotubes containing 200 ml of the vitrification solution (30% Ethylene Glycol; 20% Fetal Bovine Serum; 0 Me0.25 M e 0.75 M or 1 M su-crose) and stored in liquid nitrogen for a week. Histological analysis showed that after vitrification the number of normal follicles decreased compared to the fresh tissue (control). The percentage of normal primordial follicles was sucrose dose dependent. The percentage of normal primary follicles was similar in 0 M or 0.25 M sucrose, while higher concentrations (0.75 M and 1 M) increased significantly the percentage of abnormal follicles (p < 0.05). Morphometric analysis showed a statistically significant reduction in the total area of primordial follicles with 0.75 M sucrose and a significant increase in the cytoplasmic area of primordial follicles with 0 M sucrose (p < 0.05). The qualitative and the quantitative analysis appear to be a complementary tool when choosing a vitrification protocol. For our cryopres-ervation system-vitrification of ovarian cortex slices in cryotubes-the best vitrification medium was TCM 199-Hepes with 30% de ethylene glycol, 20% of Fetal Bovine Serum and 0 or 0.25 M sucrose. The present study shows that the use of high sucrose concentrations in the vitrification solution has a deleterious effect on the preservation of porcine preantral follicles contained in ovarian tissue. Consequently , its use at 0.75 M or 1 M wouldn't be recommended.
The objectives of this study were as follows: (i) to describe and evaluate the frequencies of dif... more The objectives of this study were as follows: (i) to describe and evaluate the frequencies of different morphologies of llama sperm nuclei, (ii) to determine morphometric values of nuclear parameters, (iii) to describe and estimate the frequencies of different classes of chromatin distribution and (iv) to measure haploid DNA content and analyse its nuclear distribution. The study was performed using ejaculates collected from seven males, and sperm nuclei were stained with the Feulgen reaction. Normal morphology ranged from 78.36% to 93.92%, and abnormalities included short, small, large, pyriform, narrow, micro and round nuclei. Important differences in nuclei considered normal were found between some males. The following average values were obtained for each sperm nuclear morphometric parameter analysed: area 11.64 μm2, perimeter 13.16 μm, length 5.12 μm, width 2.81 μm, ellipticity 1.85 and form 0.83. Differences between males were significant for all the parameters (p < .01). Light microscope observations and cytophotometric determinations allowed discriminating between three classes of chromatin distribution: homogeneous, diffuse and showing a clear band. Significant differences between males were found for the frequencies of the three classes (p < .01). Cluster analysis methods were used to estimate the resemblance between males according to the characteristics of their sperm nuclei. A great intermale variability was found for morphological, morphometric and chromatin distribution data. These parameters would have low dependence between them.
Sperm &#39;tail stump&#39; defect was found in ejaculates of a wild boar maintained in ca... more Sperm &#39;tail stump&#39; defect was found in ejaculates of a wild boar maintained in captivity. It was in good physical condition, the testes and genital tract were found to be of normal size and consistency. There was no evidence of macroscopic abnormalities at the clinical analysis and at necropsy. The volume and concentration of the semen samples obtained by electroejaculation were lower than normal. The slides examined contained a high level of abnormal spermatozoa (52.7%). The most frequent morphological finding was a droplet-like form attached to the base of the head or a very short stump. The non-stumped spermatozoa had no normal tail but a shortened one. Analysing the histological structure with light microscopy, no ring of spermatozoa was observed lining the lumen of the seminiferous tubules and the characteristically cellular structure was not conserved. The ultrastructural examination evidenced a disorganisation of the normal tubular structure of the flagellum, with lost of regular pattern of the axial bundle of fibrils and the mitochondrial helix. The origin of this abnormality is unknown.
The aim of this study was to describe the morphology, morphometry and determine the DNA content o... more The aim of this study was to describe the morphology, morphometry and determine the DNA content of yak sperm nuclei (Bos grunniens). Nuclear morphology observations were performed using light microscopy on slides stained with Feulgen reaction. Abnormalities percentages were determined: pyriform (1.2%), globose (0.2%), small (0.2%), elongated (0.1%). Morphometric measurements were made from digitized images of sperm nuclei stained with the Feulgen reaction. Mean values and standard deviations were obtained: area 21.98 ± 2.60 μm2, length 7.34 ± 0.33 μm, width 3.78 ± 0.27 μm, perimeter 88 ± 19.26 μm, roundness 1.27 ± 0.04, elongation 1.95 ± 0.11 and equivalent diameter 5.28 ± 0.27 μm. According to our knowledge this is the first time that haploid DNA content is determined. In this species 3.42 pg value that was similar to that measured in other species of the family Bovidae and other higher mammals.
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