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Biomedical subjects

G Paz

Publications and source records attributed to G Paz.

At least 55 records · Page 3Linked to original sources
PubMed1993

Experimental uremia in male rats: effect on the reproductive tract and fertility.

Chronic renal failure was induced in 3-month-old male rats by 5/6 nephrectomy. Potency and fertility studies were performed after 3 months of chronic uremia. The mean serum testosterone at the end of the experiments was significantly lower: 0.96 +/- 0.14 ng/mL compared to a control group of sham-operated male rats, 2.86 +/- 0.59 ng/mL, p < .001. All the uremic male rats had normal accessory gland weights at the end of the study. Fertility and, in most animals, sexual behavior and mating were not different from the normal control group. It is concluded that in 5/6-nephrectomized uremic male rats, in spite of low testosterone level, fertility and reproductive system are maintained similar to normal control male rats.

Animals↗
PubMed1993

[New methods for predicting sperm fertilizing ability].

There is no reliable method for screening for the fertilizing ability of sperm. 3 new methods are presented: the freezing test (FT), hypoosmotic swelling test (HOST) and migration-sedimentation test (MST). The first 2, test the functional integrity and stability of the sperm membrane under certain osmotic conditions. The MST determines ability to separate high quality sperm. All tests were performed using either fresh semen of husbands, or thawed semen of donors used for fertilization in the IVF unit. Results of the FT were not correlated with the fertilizing ability of sperm in IVF, but HOST results with fresh, but not thawed semen, were correlated. Fertilization of oocytes in IVF was significantly better when HOST value of fresh semen was 45% or more. Motility and morphological normality of sperm separated by MST were better in ejaculates that fertilized ova under in vitro conditions, than in those that did not. Sperm separation by MST of 25% or more of motile sperm, or of more than 1.5 million motile sperm in the sample, indicated statistically significant ability for oocyte fertilization in an IVF system.

Cell Membrane↗
PubMed1993

[Risk of low birth weight in the Plaza de la Habana region].

The objective of this study was to confirm the risk factors (RF) for low birth-weight (LBW) and suggest new risk factors, which were analyzed separately and together, in order to define a program to be coordinated by family doctors to reduce the frequency of this problem. For this purpose, a retrospective cross-sectional survey was carried out with 57 cases (mothers who had had LBW babies) and 58 controls (mothers who had not had LBW babies). In addition, data were obtained from the prenatal records of mothers who received care at family doctors' offices and at the clinica in the Plaza de la Habana Area. Estimates were made of the relative risk and the percentage attributable risk of 107 hypothetical RF for LBW from a clinical-epidemiological and social standpoint. One-way analysis of variance, the chi-square test, multiple linear regression, and logistic regression were used to analyze the results, which suggested the following RF for LBW: family dysfunction, family crisis, lack of spousal support, extended family, failure to attend prenatal group sessions for pregnant women, and failure to receive education on how to prevent LBW. The multifactorial risk profile was the following: risk of [corrected] intrauterine growth retardation, family dysfunction, threat of preterm delivery, coffee-drinking, attendance at fewer than 11 prenatal checkups, and failure to attend prenatal group sessions for pregnant women. The variables excluded from the model were: low weight-for-height, lack of spousal support, smoking more than 10 cigarettes a day, and family history of LBW. The findings confirmed 10 of the suspected risk factors for LBW in Cuba and nine of those described in the international literature. Maternal age, spontaneous abortion, and alcohol consumption were not confirmed. Six RF for LBW preventable by the family doctor through his/her actions at the family and community level are identified, as is a multifactorial profile of six RF for LBW. On the basis of these results, proposals are made in regard to programming priorities and the implementation of strategies aimed at preventing LBW, and it is recommended that the study be continued with a larger sample.

Adolescent↗
PubMed1992

Mumps orchitis among soldiers: frequency, effect on sperm quality, and sperm antibodies.

This study reports on 72 young soldiers who suffered from a recent epidemic of acute mumps, with special emphasis on 19 who suffered from mumps orchitis and whose spermograms were in the fertility range. The immunological work-up for antibodies in sera or seminal plasma gave normal results for the patients diagnosed with orchitis, as well as the controls. The only remarkable finding was an increased risk of borderline significance for orchitis in smokers. The present study has proven that the presence of antisperm antibodies does not play a role in the etiology of mumps orchitis.

Antibodies↗
PubMed1992

Improved fertilization rate in an in vitro fertilization program by egg yolk-treated sperm.

High fertilization and PRs have been achieved by using thawed donor sperm cryopreserved with medium containing EY. The aim of our study was to examine the possible effect of EY on the fertilizing capacity of fresh sperm in an IVF program. Preincubation of spermatozoa in EY for 2 hours at room temperature significantly improved fertilization (P less than 0.001) in couples who had low fertilization rates in previous cycles, whereas no effect was found concerning couples with high fertilization rates.

Egg Proteins↗
PubMed1992

Fresh and frozen-thawed human sperm bind in a similar pattern to the zona pellucida in the hemizona assay.

This study evaluated the impact of sperm cryopreservation on sperm quality. The HZA was used to test the binding capacity of fresh as opposed to frozen-thawed sperm from 12 donors. Fresh and frozen-thawed sperm motility was 47% +/- 1.5% and 24% +/- 3.8% (mean +/- SE), respectively. However, the number of sperm cells attached to the hemizonae was 75 +/- 12.0 and 74 +/- 11.9, respectively. We conclude that cryopreservation results in a reduced number of motile sperm cells but does not adversely affect the ability of rescued sperm cells to bind to the ZP. The study also supports the use of frozen-thawed rather than fresh donor sperm for control in the HZA procedure.

Cryopreservation↗
PubMed1992

Efficacy of varicocele embolization versus ligation of the left internal spermatic vein for improvement of sperm quality.

Efficacy of surgical varicocelectomy versus embolization of the spermatic vein was studied in 137 men diagnosed as suffering from left varicocele. The men were divided randomly into three groups according to the methods of treatment: A--embolization of the internal spermatic vein (51 men); B--Ivanissevich technique of high ligation of the spermatic veins (43 men); and C--Bernardi technique of high ligation (43 men). The groups were similar in terms of age, duration of infertility and possessed semen characterized as oligoteratoasthenozoospermia. The fertility of the female partners was evaluated carefully and they were found to be potentially fertile. Varicocele was diagnosed by at least two of the following methods: physical palpation during valsalva manoeuvre, venography, or scrotal scanning using the technetium pertechnetate radioactive method. Semen quality was assessed before treatment and at 3, 6 and 9 months post-treatment. Fecundity was followed-up for 18 months. The major results were: (i) Shrinkage of the varicocele was found in all three groups studied. The same rate of recurrence was recorded in the three groups (24%, 37% and 35% in groups A, B and C, respectively). (ii) Improvement of sperm quality was significant in groups A and B, with better results in group B. (iii) The pregnancy rate was significantly higher in group B, compared with A (38.2% vs. 20.6%; P less than 0.05). Thus, high ligation of the internal spermatic vein yields better results than low ligation or embolization as far as semen quality and pregnancy is concerned.

Embolization, Therapeutic↗
PubMed1991

The use of an electric freezer in human semen banking.

The use of an electric freezer for cryostorage of human semen is described. A simple method for semen freezing in liquid nitrogen after dilution with 7.5% glycerol was used. Thawing for quality analysis revealed only a small decrease (10%) in post-thaw sperm motility (59 +/- 1.4 vs. 53 +/- 1.8%; mean +/- SE, n = 12, P less than 10(-5)) and 14% in post-thaw sperm vitality (85.0 +/- 1.3 vs. 72.9 +/- 1.8%). After the freezing process, the samples, three of each donor, were cryopreserved in a regular electric freezer which maintained temperatures in the range of -85 degrees C (+/- 2 degrees C). The samples were stored for 1 week, 2 and 6 months, thawed and then assayed for motility and vitality. No effect of storage was found for a period up to 2 months. An additional decrease of 17.2% in sperm motility and 18% in sperm vitality were noted only after 6 months of preservation. The final motility and vitality rates of these sperm samples were 44 +/- 2.4 and 60 +/- 3.0%, respectively. According to these results, in cases of sperm storage for limited periods, it is recommended to cryopreserve human semen by the use of a combination of freezing in liquid nitrogen and storage of the samples in an electric freezer at -85 degrees C.

Analysis of Variance↗
PubMed1991

Prerequisites for successful human sperm cryobanking: sperm quality and prefreezing holding time.

Frozen-thawed donor semen was used in artificial inseminations and in vitro fertilization programs. Semen accepted for donation was characterized (mean +/- SE) by sperm concentration of 150 +/- 18.6 x 10(6)/mL, normal morphology of 57% +/- 1.4%, good progressive motility at 1 hour of 57% +/- 1.0%, and post-thaw motility of 45% +/- 1.0%. Delay of the freezing process for greater than 1 hour after semen delivery caused a deleterious effect to the freezability of sperm. The average monthly fecundability for the 1st 6 months after inseminations was 13.6%. This value decreased dramatically to 2.6% from the 7th month onward. In 74 IVF/embryo transfer (ET) cycles, the fertilization rate was 55.3% +/- 3.8%, pregnancy rate (PR) per ET was 39.6%, and the PR per woman was 42.8%.

Cryopreservation↗
PubMed1990

Serum bioactive and immunoreactive follicle-stimulating hormone in oligozoospermic and azoospermic men: application of a modified granulosa cell bioassay.

Serum follicle-stimulating hormone (FSH) levels measured by radioimmunoassay (RIA) usually correlate well with the rate of spermatogenesis. However, in certain cases this correlation does not exist. The purpose of this study was to establish a reliable bioassay of FSH for the andrological clinic. Follicle-stimulating hormone was measured by both standard RIA and bioassay in 98 men subgrouped into normospermic, oligospermic, and azoospermic. Bioactivity of FSH was determined using in vitro cultures of granulosa cells utilizing progesterone measurements for assessing FSH activity. Results of FSH levels obtained by both methods correlated well (r = 0.55, P less than 0.01) within themselves, and both correlated negatively and significantly with sperm concentration. The ratio between bioactivity and immunoreactivity of FSH did not correlate with sperm density. Thus, the decrease in sperm concentration and other sperm variables resulting from a germinal epithelial dysfunction was not mediated or associated with low biological activity of FSH. The application of this method can be of clinical value in cases where a discrepancy is found between serum RIA-FSH levels and sperm quality.

Animals↗
PubMed1990

Concentration of ofloxacin and ciprofloxacin in human semen following a single oral dose.

A single oral dose of ofloxacin (400 mg.) or ciprofloxacin (500 mg.) was administered to each of 40 men. The mean concentrations of ofloxacin in semen exceeded those of ciprofloxacin at 1 hour (p = 0.035) and 24 hours (p = 0.028), while the levels of the 2 drugs at 2 and 4 hours were comparable. Semen concentrations of ofloxacin but not ciprofloxacin exceeded the reported minimal inhibitory concentration of Enterobacteriaceae, Chlamydia trachomatis and genital Mycoplasma species 24 hours after dosage.

Administration, Oral↗
PubMed1990

Determination of urinary luteinizing hormone for prediction of ovulation.

Detection of the approximate time of ovulation is important in the in vitro fertilization-embryo transfer programs in order to avoid a possible early surge of luteinizing hormone (LH) before human chorionic gonadotropin administration in the induction of ovulation and for timing of artificial insemination. In the present study correlation between the detection of LH in urine and serum levels (mean +/- SEM) of estradiol greater than 557 +/- 118 pg/ml, progesterone less than 1.9 +/- 0.37 ng/ml and leading follicle diameter greater than 26.2 +/- 1.3 mm (mean +/- SEM) was found. Thus, the prediction of ovulation via detection of urinary LH in urine by a dipstick procedure is a good semiquantitative method, accurate enough, reliable, cheap and acceptable by the women.

Clomiphene↗
PubMed1989

A simple spot test for the detection of fructose deficiency in semen.

The concentration of fructose in seminal plasma is an important variable that should be measured in the assessment of fertility status. The current method requires the boiling of diluted seminal plasma with resorcinol. The present study offers a new two-point spot test which uses the metol method. The results of analysis of 104 seminal plasma samples are in excellent correlation with the resorcinol method. The reported method is easy to use, inexpensive, and can be introduced into any laboratory.

Aminophenols↗
PubMed1985

Effect of alpha-chlorohydrin on metabolism and testosterone secretion by rat testicular interstitial cells.

The direct effect of alpha-chlorochydrin (alpha-CH) on basic metabolism (glucose utilization and oxygen consumption) and testosterone secretion by isolated rat interstitial cells (I-cells) has been studied. In the range of concentrations between 5 and 100 microliter/ml, only the highest doses of alpha-CH decreased cell vitality and their histochemical stain for 3 beta-HSD. Oxygen consumption of I-cells was depressed at all doses higher than 10 microliter/ml and this effect was reversible only with doses lower than 50 microliter/ml. glucose utilization by I-cells was depressed significantly by alpha-CH and this effect was particularly dramatic with doses higher than 50 microliter/ml. alpha-CH decreased testosterone secretion by I-cells, with maximal effects at 100 microliter/ml. I-cells responded to hCG challenge by increasing testosterone secretion, and hCG prevented the toxic effect of alpha-CH at the lowest dose (10 microliter/ml) of alpha-CH, but failed to overcome the effects of a high dose (100 microliter/ml).

3-Hydroxysteroid Dehydrogenases↗