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Biomedical subjects

L Blasco

Publications and source records attributed to L Blasco.

At least 55 records · Page 3Linked to original sources
PubMed1983

The incidence of sperm-associated immunoglobulin and C3, the third component of complement, in infertile men.

One hundred four consecutive men who underwent a semen analysis as part of their infertility evaluation were assayed for sperm-associated immunoglobulin (Ig) and the third component of complement (C3). Sixteen (15%) of the 104 men had increased IgG, and 10 (12%) of 86 men tested had increased IgA on their sperm; however, only 4 (5%) of the 87 men tested were positive for plasma IgG antisperm antibody. Only 2 (13%) of the 16 men with increased sperm-associated IgG had detectable IgG antisperm antibodies in their seminal plasma. Five (10%) of 50 men tested had increased sperm-associated C3; none had seminal plasma that deposited C3 on sperm. These data suggest that of the three compartments that can be tested--circulating plasma, seminal plasma, and the sperm surface--the direct measurement of sperm surface Ig may be most important in the evaluation of infertile men. The presence of sperm-associated IgG or IgA was not associated with semen abnormality. In contrast, the presence of sperm-associated IgG was associated with decreased mucus penetration at the time of postcoital testing despite normal-appearing mucus.

Complement C3↗
PubMed1982

Hormones in seminal plasma.

Testosterone and prolactin play an important but unclear role in the process of spermatogenesis. Peripheral levels of these hormones are usually normal in infertile patients even when the characteristics of the sperm are subnormal. This study was conducted to evaluate the possible relationship between sperm quality and seminal content of testosterone and prolactin in 70 men. Men with normal semen analysis had venous blood levels of testosterone and prolactin that were not different from those seen in men with abnormal semen analysis while seminal concentration of testosterone was higher in the latter group of men. Testosterone concentration in semen from the 70 men investigated was 69 +/- 4 ng/100 ml, and in venous blood 487 +/- 20 ng/100 ml. However, in blood, one-third of this steroid was bound to testosterone binding globulin (TeBG), while no TeBG bound fraction of testosterone was found in seminal fluid. There was a direct correlation between the venous and seminal levels of these two hormones.

Humans↗
PubMed1982

Luteinizing hormone in cervical mucus.

The presence of material like luteinizing hormone (LH) in cervical mucus has not been previously reported. In this study, we show that in human cervical mucus there is LH-like material detectable by radioimmunoassay (RIA) and by bioassay. The content of LH in the cervical mucus of five donors was measured by RIA in samples of mucus obtained daily throughout the menstrual cycle. The concentration of LH in mucus obtained during ovulation was lower than in mucus obtained during the early follicular phase or mucus obtained during the luteal phase. This material exhibits LH-like biologic activity because increasing volumes of cervical mucus added to isolated mice Leydig cells stimulates testosterone secretion by these cells, in a parallel dose-related fashion, to increasing quantities of human chorionic gonadotropin (hCG). No immunologic cross-reactivity of the cervical mucus was observed with an antiserum specific for the beta-subunit of hCG. Taken together, the results of the present study suggest the presence of an LH-like substance within the cervical mucus that exhibits both the immunologic and biologic properties of LH.

Animals↗
PubMed1981

Zona-free hamster eggs and human sperm penetration capacity: a comparative study of proven fertile donors and infertility patients.

An in vitro penetration assay utilizing human sperm and zona-free hamster eggs was employed to evaluate human sperm fertilizing capacity for 36 patients from the infertility clinic and 9 donors of proven fertility. The infertility patients were grouped according to the normality of their semen analyses. Test results were different for the three groups: a mean penetration level +/- standard deviation of 81% +/- 26% was obtained for proven fertile donors, while a value of 14% +/- 17% was observed for infertile couples with an abnormal semen analysis. A mean +/- standard deviation penetration level of 48% +/- 33% was associated with infertile couples in which the semen analysis was normal. These groups were statistically different (P less than 0.02) when inseminations were conducted at equivalent concentrations of motile sperm. No correlation was obvious between penetration test results and any of the parameters of the semen analysis; however, penetration test results did not correlate positively with the survival index (sperm survival at the end of insemination). These results are discussed in relation to further clinical application of the test.

Animals↗
PubMed1981

Testosterone and gossypol effects on human sperm motility.

Testosterone concentration in seminal fluid has been found to be high in infertile males (75 +/- 11 pg/100 microliter). Fertile males have a testosterone concentration of 29 +/- 3 pg/100 microliter. The effects of adding 50, 150, and 300 pg of testosterone to 100 microliter of ejaculate have been studied by turbidimetric analysis (Sokoloski J, et al. Fertil Steril 28:1337, 1977). This method permits objective measurements of sperm velocity and percentage of rapidly moving sperm in a sample (%RM). A dose-dependent effect of testosterone on sperm motility was seen. Fifty pg/100 microliter had no effect on velocity or percentage of moving sperm; 150 pg of testosterone produced a decrease of 36% +/- 8; and 300 pg/100 microliter, a decrease of 62% +/- 8. Caffeine had a stimulatory effect on the percentage of motile sperm at doses of 400 microliter of semen. Likewise, dibutyryl cAMP (10 microgram/microliter) had a positive effect on sperm velocity. The stimulatory effect of these two drugs were negated when 300 pg of testosterone was added to the preparations. Other steroids (17 alpha-testosterone, 17 alpha-estradiol, and 17 beta-estradiol, DHT, and progesterone) tested under the same experimental conditions had no effect on sperm motility, but cottonseed oil (goosypol) had drastic effects. Doses a little as 100 pg/100 microliter produced a 90% decrease in sperm motility.

Bucladesine↗
PubMed1980

Placental alkaline phosphatase in nonmalignant human cervix.

At least three loci determine human alkaline phosphatases [orthophosphoric-monoester phosphohydrolase (alkaline optimum), EC 3.1.3.1]: one coding for the placental form of the enzyme; at least one coding for the intestinal forms; and at least one for the liver, bone, and kidney forms. It is generally believed that the locus determining the placental form is, in the normal individual, expressed only in placenta. However, ectopic or aberrant expression of this locus occurs in certain malignancies of other tissues and in cell lines, such as HeLa, derived from malignancies. We have examined by thermostability, inhibition, and immunologic studies the alkaline phosphatases in endocervix, cervical mucus, and endometrium from nonpregnant women with no evidence of malignancy. It was found that on the average about 18% of the alkaline phosphatase activity in endocervix and in cervical mucus is placental in type, the remainder being of the liver/bone/kidney type. The quantity of the placental enzyme is, however, low and amounts to only about 0.5% of the amount in normal term placenta. In endometrium all the alkaline phosphatase activity was of the liver/bone/kidney type. Thus the placental alkaline phosphatase locus is expressed in nonmalignant endocervix. The result is of some significance in connection with the widely held view that the expression of placental alkaline phosphatase in certain malignancies (including cervical malignancy) is due to derepression of a locus for a fetal enzyme protein normally repressed in adult tissues.

Adult↗
PubMed1979

A practical, objective approach to the evaluation of sperm and cervical mucus in humans.

Human sperm fertility potential, expressed as a quality index (QI), was evaluated objectively from considerations of sperm velocity, percentage of motile forms, sperm density, and ejaculate volume. Turbidimetry was applied in the quantitation of sperm velocity. High QIs (700) were characteristic of semen samples that were capable of penetrating cervical mucus in capillary tube penetration tests, while low QIs (80) were associated with specimens that did not penetrate mucus. The rate of decline in QI as a function of time postejaculation was determined for samples stored at 37 degrees C and at ambient temperature, providing correction factors for the comparative evaluation of semen samples analyzed at different times. The penetrability of cervical mucus was determined by capillary tube penetration testing. Subsequent chemical analysis of sperm-penetrable and impenetrable samples indicated that the concentrations of mucus nondialyzable solids (NDS), mucins, and soluble proteins were significantly higher in impenetrable specimens. These characteristics were also observed in impenetrable mucus obtained from patients with cervical factor infertility. These studies indicate that it is now feasible to employ mucus [NDS] in the diagnosis of cervical factor infertility and turbidimetry in the evaluation of human sperm quality.

Cervix Mucus↗
PubMed1979

Human cervical mucus. V. Oral contraceptives and mucus rheologic properties.

Mucus viscoelasticity on individual samples obtained from patients using combination oral contraceptives was quantitated by microrheometry. These results, in conjunction with mucus chemical characterization, indicate that combination oral contraceptive use eliminates the cyclic variations in mucus chemical, physicochemical, and rheologic properties associated with the ovulatory menstrual cycle. A correlation was demonstrated between the mucus elastic modulus and mucus nondialyzable dry weight, and the mucins produced during oral contraceptive therapy were shown to be similar to those recovered from ovulatory donors. Differences in mucus properties were noted when donors using estrogenic contraceptives were contrasted with those using androgenic contraceptives. On the basis of established relationships between sperm penetrability and mucus solids content, it was concluded that the use of contraceptives, as examined in this study, provided a secondary degree of fertility control at the cervical level.

Cervix Mucus↗
PubMed1978

Human cervical mucus. IV. Viscoelasticity and sperm penetrability during the ovulatory menstrual cycle.

Quantitative viscoelastic and sperm penetration measurements were made on individual human cervial mucus samples collected from several ovulatory menstrual cycles. An inverse relationship was found to exist between these two mucus properties, with peak penetrability seen during the ovulatory phase of the cycle when viscoelasticity was lowest. Limited sperm penetration was also observed with follicular phase mucus. When mucus was collected three times daily, the first sample of the day showed reduced pH values and elevated percentage of nondialyzable solids (NDS) and viscoelastcity. Rates of mucus production were calculated for two cycles; the highest rate was seen during the ovulatory phase, with the follicular and luteal phases showing approximately 50% and 30% of this rate, respectively. Limited disparities were noted between midcycle changes in percentage of mucus NDS and viscoelasticity and in blood levels of total estrogens.

Cervix Mucus↗
PubMed1977

Human cervical mucus. II. Changes in viscoelasticity during the ovulatory menstrual cycle.

Quantitative viscoelasticity measurements were made on individual human cervical mucus samples by microrheometry. Increases in mean values for mucus spinnbarkeit, ferning, and wet weight were associated with the ovulatory phase of the menstrual cycle, while no significant differences versus time were noted for mean values for sample pH or nondialyzable dry weight. A nadir in mucus nondialyzable solids (NDS) concentration and in visoelasticity was seen at or near midcycle. Substantial, highly reproducible, variations in mucus viscoelasticity were observed when mucus from different donors was compared. When the contribution of (NDS) to viscoelasticity was minimized by data normalization or by sample reconstitution, a significant increase in viscoelasticity was associated with the ovulatory phase of the cycle, suggesting the occurrence of a relative increase in mucin concentration or a compositional change in the mucus.

Cervix Mucus↗
PubMed1977

Turbidimetric analysis of human sperm motility.

A turbidimetric method has been developed for determining rapidly the fraction of sperm in human ejaculates which show the most vigorous motility. The method is based on the fact that sperm cells so endowed will be the first to swim upward into clear medium from a concentrated cell suspension at the bottom of an optical cuvette. This results in a time-dependent increase in turbidity in the medium which is recorded spectrophotometrically as an increase in absorbance. The determination requires 10 minutes and yields both the fraction of rapidly moving sperm, FRM, and their average velocity, VRM. Examination of 25 samples yielded FRM values of 10% or lower, whereas values for VRM averaged about 100 microns/second. These vigorously motile cells may be the best candidates for fertilization, and samples with a high fraction of such cells should have high fertilizing capacity. It is suggested that this simple turbidimetric test be used in evaluation of human semen as a possible indicator of fertilizing capacity.

Humans↗
PubMed1977

Human cervical mucus. I. Rheologic characteristics.

The viscoelastic properties of human cervical mucus were subjected to detailed characterization by microrheometry. An introduced to the range of parameters that can be measured and the sensitivity of microroheometry to variations in mucus viscoelasticity was presented, along with an interpretation of results obtained by this approach. Fresh cervical mucus samples were shown to be rheologically heterogeneous, reflecting compositional differences in situ. Mucas viscoelasticity was stable for several hours when samples were stored at ambient temperature in the microrheometer sample holder. Mucus viscoelasticity was strongly dependent upon nondialyzable solids (NDS) concentration. In order to eliminate (NDS) as a variable in comparative studies of mucus, procedures were developed for reconstitution of mucus at identical (NDS) or for normalization of viscoelasticity data derived from fresh samples to 2.5% NDS. The validity of this approach was then examined by applying these procedures to mucus collected during the follicular, ovulatory, and luteal phases of the normal menstrual cycle.

Animals↗