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Biomedical subjects

M C Quiros

Publications and source records attributed to M C Quiros.

9 recordsLinked to original sources
PubMed1993

The increased risk of complication observed in singleton pregnancies resulting from in-vitro fertilization (IVF) does not seem to be related to the IVF method itself.

Singleton pregnancies resulting from in-vitro fertilization (IVF) seem to have an increased risk of obstetric and paediatric complications. In a retrospective study we compared, during the same period, 162 IVF singleton pregnancies with 263 pregnancies resulting from stimulated cycles (without IVF) and with 5096 natural pregnancies. No significant difference was found between the first two groups concerning complications (i.e. prematurity, low birthweight, small-for-gestational-age and perinatal mortality). The results indicate that an adverse outcome is more common for pregnancies after ovarian stimulation (with or without IVF) compared to natural pregnancies. Therefore the increased risk does not appear to be linked to the IVF method itself but rather to a common factor in these two populations, i.e. population characteristics, underlying infertile status and/or ovarian stimulation.

Adult↗
PubMed1983

Thyroid gland and epididymal function in rats. II. Sperm motile efficiency.

The epididymis is controlled by the endocrine system and plays an active role in the process of spermatic maturation. In order to extend these studies, our investigations were focused on the relationship between the hypofunction of the thyroid gland and the motility of the caput, corpus, and cauda epididymal spermatozoa. The hypofunction was associated with decreasing sperm motility efficiency. In thyroidectomized rats injected with T-3, no sperm motility changes were observed.

Animals↗
PubMed1979

Thyroid gland and epididymal function in rats--histological study.

An experiment was designed to determine the relation between the hypofunction of the thyroid gland and the structure of the epididymis. The hypothyroid condition was associated with decreased mitosis, insufficient vascularization, decreased nuclear size, and chromatin decondensation. In thyroidectomized rats injected with T3, no morphological changes in the epididymis were observed.

Animals↗
PubMedDate not supplied

Adenosine 5'-triphosphate (ATP) concentration and acrosin activity in human spermatozoa. Their relation with the sperm penetration assay (SPA).

Fertility of men depends on the quality of semen. The aim of the present paper is to determine both the acrosin activity by radioimmunoassay and ATP concentration by bioluminescence in human spermatozoa, and evaluate these results in those samples with normal or low sperm penetration according to SPA test. Ejaculates obtained from 42 untreated men, were studied one hour after the obtention. These materials were divided into two groups:20 human semen samples with "in vitro" potentiality to penetrate zone-free hamster ova, between 15% to 98% and 22 human semen with SPA test between 0% to 14%. When we compare the group with normal penetration response vs that group with low or absent penetration ones, a significant decrease of ATP and acrosin concentrations was observed (P less than 0.001). Nevertheless no significant difference was observed in relation with percentage of motility, volume (ml), sperm concentration (10(6)/ml), percent of quick progressive spermatozoa and number of gametes capable of migrating into the medium layer (10(6)), between the group with low or absent penetration test against that one with normal zona-free hamster egg test.

Acrosin↗
PubMedDate not supplied

Comparison between swim-up and glass bead column techniques for the separation of human spermatozoa.

The glass bead column filtration method was compared with the swim-up technique regarding spermatozoa recovery in normal and pathological human semen. The general characteristics of the semen and the spermatic ATP concentration were measured in 67 patients. Samples processed with glass bead columns provided a good amount of motile forms which however, showed less velocity and linearity than in the case of using the swim-up technique. Additionally, the ATP determination in spermatozoa was included.

Cell Separation↗
PubMedDate not supplied

Development of an objective and manual technique to study the human sperm morphology.

The aim of the present paper is to present results of sperm morphology using an objective and manual technique by video image. Experiment 1:252 spermatozoa heads were measured in a microscope and in a monitor by each of three independent observers. The results allowed the calibration of an acetate overlay according to the WHO guideline and following the strict criteria. Experiment 2: 10 morphology slides from normal and abnormal patients were studied. These slides were evaluated by three independent observers, each counting at least 200 cells using the calibrate acetate overlay. In the first experiment the calculation of the regression out-put was: constant: 0.24, standard error of Yc: 0.04, R squared: 0.96, X coefficient: 0.36, and standard error of the coefficient: 0.03. In the second experiment, it can be seen that the differences among the operators are not statistically significant and therefore the experiment is independent from the operator. In conclusion, the methodology developed in this paper for the evaluation of morphology would be a good tool for the evaluation of human sperm morphology.

Cytological Techniques↗
PubMedDate not supplied

Effect of lipid peroxidation upon human spermatic adenosinetriphosphate (ATP). Relationship with motility, velocity and linearity of the spermatozoa.

The aim of the present paper was to study the effect of forced lipid peroxidation upon human spermatozoa and its relation with motility, velocity, linearity and ATP content. Forty-three pools of semen samples were studied one hour after liquefaction. After washing, normal and pathological spermatozoa presented no variations in motility, velocity or linearity with respect to basal values. Forced peroxidation produced a significant decrease of motility, velocity and linearity (p less than 0.02) with respect to control. Spermatic ATP was not significantly different in control vs forced peroxidation groups in normozoospermic samples. In contrast, a significant decrease of ATP between control and peroxidation groups was observed in asthenozoospermia at 120 minutes of incubation (p less than 0.02). In the asthenozoospermic group, a significant LPO-p increase was observed in comparison with the normal group.

Adenosine Triphosphate↗
PubMedDate not supplied

Computer assisted measurement in normal and pathological human semen, fresh and post swim-up technique.

A total of 429 semen samples were studied. Two hundred and twenty-nine samples with normal characteristics were processed following a basic procedure; the remaining 200 were normal and pathological samples that were analyzed pre and post swim-up. Semen specimens were allowed to liquefy for 30 minutes and sperm count, motility, velocity and linearity were determined using the Cellsoft Automatic Semen Analyzer. In normal patients, a significant increase of motility, velocity and linearity (p less than 0.001) post swim-up, was observed. Sperm recovery in this group was 13.9 +/- 1% of the whole motile sperm population. In the polyzoospermic group, recovery of motile spermatozoa post swim-up was significantly decreased as compared with the normal group (p less than 0.001). In the asthenozoospermic group (plus either hypospermia or hyperspermia, or with more than 30% of motile spermatozoa or less than 30% of motility), no variations of velocity or linearity as compared to the normal group were observed. In all the pathological groups studied, a significant increase in velocity and linearity (p less than 0.001) post swim-up, was observed.

Computers↗