Biomedical subjects

M Zinaman

Publications and source records attributed to M Zinaman.

8 recordsLinked to original sources

PubMed1998

Identification of estrogen receptor protein and messenger ribonucleic acid in human spermatozoa.

OBJECTIVE: The processes leading to fertilization involve a series of sequential events including the deposition and transport of sperm in the female genital tract. It is becoming evident that spermatozoa in which a hyperactive state has been induced are more effective in both reaching and penetrating the oocyte. Many of the changes that spermatozoa undergo are the result of their ability to respond to the milieu of the female genital tract. In the presence of estrogen sperm have been shown to have increased their metabolic activity and flagellar activity and to have an increased ability to penetrate oocytes. Most important, these observed changes in sperm physiology occur quickly, suggesting a novel second-messenger system coupled to the estrogen receptor. Established effects of steroid hormones involve mediation of the signal through genomic expression. However, because it has not been definitively demonstrated whether the human sperm express the estrogen receptor, the mechanism by which estrogen exert its effect remains to be elucidated. STUDY DESIGN: The presence of estrogen receptors on human spermatozoa was investigated. Immunohistochemistry performed on human spermatozoa indicates that the estrogen receptors are located on the tailpiece. In addition, protein from human spermatozoa was isolated and subjected to Western blot analysis. RESULTS: Results indicate a single band of approximately 65 kd, similar to that of the native human estrogen receptor. Ribonucleic acid obtained from the human spermatozoa was reverse transcribed into deoxyribonucleic acid. With use of selected primers, this deoxyribonucleic acid was amplified by polymerase chain reaction. Resolution and examination of the expansion products demonstrated a single band of deoxyribonucleic acid of 450 bp, identical to that expected from the selected primers. The specificity of this reverse transcriptase-polymerase chain reaction amplified deoxyribonucleic acid sequence was verified by Southern blotting. CONCLUSION: For the first time we provide evidence as to the expression of estrogen receptor by human spermatozoa.

Blotting, Southern↗

PubMed1992

Laboratory methods for assessing human semen in epidemiologic studies: a consensus report.

It is clear that additional methodologic work needs to be performed. Some data gaps described above are being actively investigated. Other standards were not addressed at this meeting; statistical handling of the data, differences among CASA machines, and factors to consider as potential confounders in analysis are just a few. These may be the subject of future workshops, which will also review progress made in the existing knowledge base. For now, this effort represents a first attempt to share information and to use it to encourage investigators in different laboratories to employ similar methods. In this way more direct comparisons among studies can be made, and our collective data base can be strengthened.

Computers↗

PubMed1991

Efficacy of the symptothermal method of natural family planning in lactating women after the return of menses.

This study was designed to determine the efficacy of the symptothermal method of natural family planning during lactation. Although the method appears to give a reasonable reflection of fertility potential over time, it overlaps with the profound influence of lactation in both ovulation suppression and the delay of luteal phase adequacy. Further analysis is planned to attempt to identify those particular mucus signs and symptoms that are helpful during the transition from lactational amenorrhea to normal cycling.

Body Temperature↗

PubMed1989

The physiology of sperm recovered from the human cervix: acrosomal status and response to inducers of the acrosome reaction.

Cervical mucus was collected from 35 women after artificial insemination. Mucus collections were performed at 1 h, 1 day, 2 days, or 3 days following insemination. Sperm viability was greater than 80% at all recovery times as assessed by exclusion of the supravital dye Hoechst 33258. Virtually 100% of the viable sperm were acrosome-intact at all times as assessed with a fluorescein isothiocyanate-conjugated pea lectin. Sperm were recovered from the mucus after migration into the Biggers, Whittin, and Whittingham medium in vitro. Sperm did not undergo the acrosome reaction in response to human follicular fluid immediately after migration from the mucus but did respond to this agonist after 6 h of incubation in vitro. Sperm recovered at all times after insemination had the same pattern of response to follicular fluid. Sperm that penetrated a column of cervical mucus in vitro also responded to follicular fluid with an increase in acrosome reactions after migration from the mucus and incubation for 6 h in vitro. Unlike the sperm that migrated from cervical mucus, sperm that were separated from semen by Percoll density centrifugation did not undergo the acrosome reaction when challenged with follicular fluid after 6 h but did respond after 24 h incubation. Sperm that migrated from cervical mucus had a similar increase in acrosome reactions after 6 h incubation, regardless of whether the acrosome reaction agonist was follicular fluid or disaggregated human zona pellucida.(ABSTRACT TRUNCATED AT 250 WORDS)

Acrosome↗

PubMed1988

Computer-assisted semen analysis: evaluation of method and assessment of the influence of sperm concentration on linear velocity determination.

Semen samples from 77 men were used to estimate the accuracy and precision of measurements of sperm density, percent motility, and motion characteristics using a new, fully automated, computer-assisted semen analyzer (CASA). Results are compared with traditional semen analysis methodology. Acceptable precision for count and percent motility was obtained using three to nine random fields of observation when there were more than 10 cells per high-power microscopic field. A highly significant correlation (P less than 0.01) was found between the two methods in the assessment of sperm concentration and percent motility, but CASA overestimated concentration significantly (P less than 0.01) by about 30% when there were less than 60 cells per high power field. This overestimation seemed to be due to the number of nonsperm particles in semen that are confused with spermatozoa by the program. Linear velocity determination was influenced by the number of tracking points as well as by the concentration of cells present in the counting chamber. More representative linear velocity estimations in semen were obtained when sperm concentration was less than 40 x 10(6) cells/ml and 20 tracking points were used in the determination. For semen specimens containing higher cell density, sperm concentration needed to be reduced by diluting the semen with the patient's own sperm-free seminal plasma before measuring motion characteristics.

Computers↗

PubMed1986

Plasma catecholamine responses to physiologic stimuli in normal human pregnancy.

The dynamic response of the sympathoadrenal system was evaluated during and after pregnancy in 13 healthy women with a protocol that compared cardiovascular parameters and plasma catecholamine levels during the basal state, after postural maneuvers, and following isometric exercise. Plasma epinephrine and norepinephrine levels were similar during and after gestation when the women rested on their sides, but heart rate was greater in pregnancy. Ten minutes of supine recumbency produced minimal changes, but attenuation of the anticipated increases in heart rate and plasma norepinephrine levels during standing and isometric exercise were observed during pregnancy. In contrast, alterations in plasma epinephrine appeared unaffected by gestation. Plasma renin activity and aldosterone levels were, as expected, greater during pregnancy; however, increments in response to upright posture were similar in pregnant and postpartum women. To the extent that circulating catecholamines may be considered indices of sympathoadrenal function, these data suggest that normal pregnancy alters cardiovascular and sympathetic nervous system responses to physiologic stimuli.

Adolescent↗

PubMed1985

Serial plasma oncotic pressure levels and echoencephalography during and after delivery in severe pre-eclampsia.

Plasma colloid osmotic pressure (PCOP) and echoencephalograms were monitored serially during and after labour in nine nulliparous severe pre-eclamptics receiving parenteral fluids, including infusions of magnesium sulphate and hydralazine. Nine normotensive, age-matched, nulliparous women in labour served as controls. PCOP, lower in the pre-eclamptics (16.1 +/- SD 0.6 mm Hg vs 19.9 +/- 0.7 mm Hg in controls, p less than 0.001) before the start of parenteral infusions, decreased in both groups and at delivery it was 14.1 +/- 0.5 mm Hg in the hypertensive women and 17.2 +/- 0.6 mm Hg in the controls p less than 0.001). After reaching a nadir between 16 and 18 h post partum (pre-eclamptics: 13.8 +/- 0.5 mm Hg; controls 16.2 +/- 0.8 mm Hg; p less than 0.001) the levels rose and at 6 weeks post partum they were greater in the pre-eclamptics (26.2 +/- 1.1 mm Hg vs 22.7 +/- 0.8 mm Hg; p less than 0.01) although the blood pressure in this group had returned to normal. Middle cerebral ventricle width was similar in the pre-eclamptic and normotensive women and remained unchanged during labour and 1 day and 6 weeks post partum. No echographic evidence of brain swelling or symptoms suggestive of pulmonary congestion were observed in either group. The potentially dangerous low PCOPs during and after labour in pre-eclamptic women emphasise the need for minimising crystalloid therapy in pre-eclamptics during labour.

Adolescent↗

PubMedDate not supplied

The relationship of the postcoital test and semen characteristics to pregnancy rates in 200 presumed fertile couples.

OBJECTIVE: To evaluate the postcoital test (PCT) and semen analysis (SA) in the prediction of pregnancy in 200 potentially fertile couples. METHODS: 200 couples without risk for infertility were prospectively followed for 1 year. Couples were attempting pregnancy for 12 menstrual cycles. In the first three cycles, the women underwent monthly PCTs and collected daily urines while the men provided bimonthly semen analyses. For the next nine cycles, the couples were monitored for pregnancy. The PCT included hours post-coitus, amount of mucus, spinnbarkeit, number of motile sperm, and percent of motile sperm. Since multiple PCTs and SAs were available for each couple, values were averaged to provide one mean value per couple. The Wilcoxon ranked sum test was used to detect differences in PCT and SA. RESULTS: Pregnancy occurred in 163/200 couples (82%) in 12 cycles. Mean sperm count per high-power field (p = 0.01) and mean number of highly motile sperm (p = 0.03) were higher among women in whom pregnancy occurred. Amount of mucus and spinnbarkeit were similar between women who became pregnant and those who did not. Semen concentration, motile sperm count, and percent motile sperm were significantly higher among men whose partner conceived (P < .02). Only 93 couples (47%) had PCTs that were correctly timed. CONCLUSIONS: Measures predictive of pregnancy included vigorously moving sperm per high-power field, sperm concentration, motile sperm count, and percent motility. Mucus characteristics were not predictive of pregnancy. Additionally, a high number of sperm seen in the PCT correlated with a high number of motile sperm in the SA. These results support the use of the PCT for initial evaluation of the infertile couple.

Adult↗