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Biomedical subjects

D F Katz

Publications and source records attributed to D F Katz.

At least 55 records · Page 3Linked to original sources
PubMed1988

Changes in human sperm motion during capacitation in vitro.

Spermatozoa from 10 fertile donors and from 10 patients with infertile marriages were washed and centrifuged (time zero, T0), and incubated in vitro in capacitation media for 6 h (T6), or 24 h (T24). At each time individual spermatozoa were classified as being morphologically normal or abnormal, and their movement characteristics were determined using high-speed videomicrography. Zona-free hamster oocytes were added to the T24 sperm suspensions. At all times, morphologically normal spermatozoa from donors and patients swam faster and had greater rolling frequency, flagellar beat frequency and amplitude than did abnormally shaped cells. Morphologically normal spermatozoa from donors exhibited a significant change in their movement pattern at T6. This change, which resembles hyperactivation in other species, was characterized by higher values of amplitude of lateral head displacement, and lower values of linearity, beat frequency and flagellar curvature ratio. In contrast, normal spermatozoa from patients showed only a decrease in straight line velocity at T6, with no other significant changes in movement characteristics. No changes in sperm movement could be demonstrated for the abnormal cells in either group of subjects. In sperm suspensions from donors and patients examined at T24, sperm vigour declined regardless of the morphological type. Spermatozoa from all 10 donors were able to penetrate the zona-free hamster oocytes, but spermatozoa from 5 of the 10 patients failed to penetrate oocytes. Correlations between hamster oocyte penetration and indicators of sperm vigour were demonstrated only for spermatozoa of patients.

Humans↗
PubMed1988

Prospective surveillance of semen quality in the workplace.

We performed a prospective surveillance of semen quality among workers in the plant where 1,2-dibromo-3-chloropropane was first recognized as an occupational cause of impaired semen quality and of infertility. All male employees of the Agricultural Chemical Division were required to participate. Ninety-seven workers (92% participation) provided 258 semen samples over the 4 years of the program. Most samples were analyzed at the plant with a mini-laboratory designed for the study. Motility and shape measures were made objectively. Sixty-six subjects (68%) were non-azoospermic. Generalized multiple regression showed no significant predictors for any response, with the exception of the motility measures, which were reduced with longer times between ejaculation and assay. Between- and within-person standard deviations and correlations were calculated. Comparison of this population with fertile artificial insemination donors (16 men, 498 ejaculates) revealed generally higher ejaculate-to-ejaculate standard deviations in the worker samples. This is probably due to less well controlled conditions of sperm collection in the workplace setting. For cross-sectional studies, one ejaculate per worker is recommended as sufficient; for estimating an individual worker's mean, even three ejaculates may not provide enough precision.

Environmental Exposure↗
PubMed1987

Semen analysis.

The capability to analyze semen is not new but until recently was a clinical art practiced well by only a few experts. The development of objective, quantitative methods for semen evaluation has brought these diagnostic capabilities to every clinical laboratory. These methods are described, and an interpretation of semen parameters is presented for the reader.

Humans↗
PubMed1986

In vitro studies of the golden hamster sperm acrosome reaction: completion on the zona pellucida and induction by homologous soluble zonae pellucidae.

We have studied the occurrence of the golden hamster sperm acrosome reaction (AR) in vitro during interaction with the oocyte investments: the cumulus cell matrix and the zona pellucida. Hamster sperm were capacitated in a defined medium that does not induce the AR. These spermatozoa were allowed to interact with the ovum vestments, the events of which were recorded using high-speed videomicrography. Frame-by-frame analysis revealed that sperm did not complete the AR in the cumulus cell matrix, but did so on the zona pellucida. Furthermore, a higher percentage of sperm completed the AR on the zona pellucida of cumulus-invested than on cumulus-free eggs. We also investigated the effect of solubilized hamster and mouse zonae pellucidae on the hamster sperm AR. Addition of solubilized hamster zonae to capacitated sperm elicited the AR within 15 min. Solubilized mouse zonae were significantly less effective, indicating that the zona-induced AR in hamster sperm may be species specific. These results suggest that the hamster zona pellucida is an inducer of the AR in the intact or soluble form, and that the majority of spermatozoa traverse the cumulus cell matrix without completing the AR in our in vitro system.

Acrosome↗
PubMed1985

Real-time analysis of sperm motion using automatic video image digitization.

A methodology is described for automatic, real-time analysis of sperm movement characteristics. Video micrographic images of spermatozoa are digitized, compressed, and then analyzed using a Motion Analysis Corporation Expert Vision system. The system includes a VP-100 video processor, a video camera, and a Sun-2/120 minicomputer. Algorithms for detection of and discrimination among sperm are described, and desirable operating characteristics of the system are considered. Salient parameters which characterize the kinematics of sperm swimming trajectories are discussed.

Analog-Digital Conversion↗
PubMed1985

Increases in human sperm oxygen consumption at low cell concentrations.

Human spermatozoan oxygen consumption was measured in semen serially diluted with its own plasma, and shortly after serial dilution of washed spermatozoa in an artificial medium. In both media, per-sperm oxygen uptake rose significantly when sperm concentration fell below the range of 15-25 X 10(6) cells/ml. Oxygen uptake was higher in the artificial medium, regardless of sperm concentration. Sperm oxygen consumption in the artificial medium declined over times short enough that no change in the percentage of motile spermatozoa was detected.

Humans↗
PubMed1984

A possible role for potassium and pyruvate in the modulation of sperm motility in the rabbit oviducal isthmus.

Spermatozoa were recovered from the isthmus of the rabbit oviduct at 4 and 11 h post coitum using several defined flushing media. The motility of spermatozoa in the isthmic flushings was subsequently analysed from video recordings. There was little sperm movement in the native isthmic fluid, but vigorous flagellar activity and hyperactivated movement were induced by flushing the isthmus with 0.25 M-sucrose, apparently an effect of dilution. Flushing with a complex culture medium resulted in similar stimulation of sperm movement. When pyruvate was present in the medium, hyperactivated flagellar bending was stimulated, whereas these movements were virtually absent when glucose alone was present. The stimulating effect of dilution was less pronounced when the flushing medium contained 50 mM-potassium. When the isthmus was flushed with media containing 50 mM-K+ and the K+ concentration was lowered to 5 mM during a washing procedure, large-amplitude flagellar movements were sequentially suppressed and restored. The restoration of large-amplitude movements was enhanced when pyruvate was present in the 5 mM-K+ washing medium. These results suggest that alterations in the concentration of both K+ and pyruvate may have a role in regulating the motility of rabbit spermatozoa in the oviducal isthmus, K+ being inhibitory and pyruvate stimulatory.

Animals↗
PubMed1983

Human sperm penetration of zona-free hamster eggs after storage of the semen for 48 hours at 2 degrees C to 5 degrees C.

The motility of human spermatozoa and their ability to penetrate zona-free hamster eggs were examined after dilution of the semen with TES-Tris (TEST) yolk buffer and storage for 48 hours at 2 degrees C to 5 degrees C. Semen samples from 10 fertile donors and 19 infertility patients were studied. More than 65% of the spermatozoa which were initially motile in the TEST yolk buffer remained active after storage. During storage, the mean swimming speed of the sperm declined to approximately 60% of the prestorage value. The percentage of zona-free hamster eggs that were penetrated by spermatozoa from patients and donors increased significantly following 48 hours of storage at 2 degrees C to 5 degrees C. Normal semen and abnormal semen were equally preserved by this storage method. This procedure may be used to ship semen samples by commercial transportation to specialized laboratories for testing. Low temperature storage in the TEST yolk buffer appears to enhance the fertilizing capacity of human spermatozoa in vitro.

Animals↗
PubMed1983

Assessment of a new spermicidal agent against ejaculated dog and human spermatozoa in vitro.

The spermatostatic potencies of a new vaginal contraceptive agent, RS-37367, and a standard surfactant compound, nonoxynol-9, have been compared by using ejaculated dog and human spermatozoa. RS-37367 was 25 to 50 times more potent than nonoxynol-9 against dog spermatozoa. Nonparallel concentration-response lines were obtained against human spermatozoa. Concentrations of RS-37367 causing immediate spermatostasis against dog spermatozoa resulted in vesiculation of the plasma and outer acrosomal membranes of spermatozoa; similarly, immediately spermatostatic concentrations of nonoxynol-9 were associated with the previously documented generalized membrane stripping. The activities of both RS-37367 and nonoxynol-9 were affected by the concentration of dog spermatozoa in semen-compound mixtures. Short-term (5-minute) exposure of spermatozoa to concentrations of RS-37367 not immediately spermatostatic resulted in progressive immobilization of spermatozoa. Extensive washing of the spermatozoa was not able to reverse this effect, in contrast to spermatozoa transiently exposed to nonoxynol-9.

Animals↗
PubMed1983

What functions of the sperm cell are measured by in vitro fertilization of zona-free hamster eggs?

Human spermatozoa were capacitated in media containing either high concentrations (3.5%) of human serum albumin (HSA) or low concentrations (0.3%) of bovine serum albumin (BSA). The effects of both capacitation media were assessed immediately and after overnight preincubation (18 to 24 hours) by adding a mixture of nonliving human oocytes and living zona-free hamster eggs to the sperm suspension. Overnight preincubation of sperm in media containing 3.5% HSA enhanced sperm fusion with hamster vitelli, but the capacity for zona penetration was lost. These effects could be attributed to the concentration of HSA rather than a general effect of albumin concentration, because overnight preincubation in 3.5% BSA did not interfere with zona penetration. During overnight incubation in 3.5% HSA, the percentage of acrosome reactions increased, as did alterations in the equatorial segment of the acrosome-reacted sperm. The percentage of motile sperm remained high after overnight incubation in 3.5% HSA, but both the mean swimming speed and flagellar activity on the zona surface declined. The sperm also lost their ability for strong zona binding after overnight incubation in 3.5% HSA.

Animals↗
PubMed1983

Movement characteristics of bovine epididymal spermatozoa: effects of forward motility protein and epididymal maturation.

Movement characteristics of untreated bovine caudal epididymal spermatozoa were compared by high-speed cinemicrography with those of theophylline-activated caput epididymal spermatozoa with and without added forward motility protein (FMP). Comparison of individual movement characteristics clearly established the importance of FMP in converting the nonprogressive motility of theophylline-activated caput sperm into the progressive swimming of mature caudal sperm. Although the total or curvilinear distance traveled in 1 sec by theophylline-activated caput sperm was not changed by the addition of FMP, the linear progression was doubled and the percentage of progressively motile sperm was tripled by this protein. Untreated caudal sperm were 80% motile and theophylline-activated caput sperm were nearly 50% motile; the percentage of motile sperm that were progressive was the same for theophylline-activated caput sperm with FMP and for untreated caudal sperm. Caput sperm without FMP roll infrequently, if at all, but caput sperm with FMP and caudal sperm roll at 4.7 Hz. The beat frequency increases significantly with the addition of FMP and is even higher for caudal sperm. The hydrodynamic power output rises concomitantly with the beat frequency. Perhaps the most striking difference between caput sperm without FMP and those with it is in the swimming paths they follow. Caput sperm without FMP exhibit frequent reversals in direction, or yawing of the sperm heads as they loop back and cross over their tails in an apparently very flexible bending. Their average swimming paths are circles. Caput sperm with FMP and caudal sperm do not show this behavior, but swim in average paths which are linear. The minimum radius of curvature of the tail of caput sperm without FMP is much smaller than that for the other two cell types. These studies clarify the role of FMP in epididymal development of sperm motility.

Animals↗
PubMed1983

Movement characteristics and acrosomal status of rabbit spermatozoa recovered at the site and time of fertilization.

Rabbit spermatozoa were recovered from the oviductal ampullae 11 h postcoitus by an oil microflush technique. Their movement was evaluated in the ampullar fluid, or in ampullar fluid diluted with in vitro fertilization medium, in slide preparations which were approximately 25 micron or 100 micron deep. The movement of these sperm was compared with the movement of ejaculated sperm in diluted semen. Movement parameters measured from videotapes recorded by a high-speed camera were coded according to treatment and entered into a microcomputer for statistical analysis. A total of 157 spermatozoa were recovered from the oviducts of 16 does: 152 were motile and 126 were free-swimming. Nearly all of the free-swimming sperm swam in trajectories whose average paths were circular. The flagellar beat pattern of the circular swimmers was asymmetric and nearly planar, and the sperm did not roll. Spermatozoa observed in 25-micron slide preparations produced smaller flagellar bends than sperm swimming in 100-micron preparations and tended to swim in larger circles which were oriented in the plane of the slide. Spermatozoa observed within the cumulus matrix moved in a slow, erratic, sinuous manner, but resumed rapid circling upon leaving the matrix. It was concluded that the ampullar sperm were hyperactivated, retaining this physiological condition as they entered the cumulus. The movement qualitatively resembled that of hyperactivated guinea pig and hamster spermatozoa because these species effectively swim in circles. In contrast, 80% of the ejaculated spermatozoa swam in linear trajectories, resulting from relatively symmetrical, flagellar beat patterns. The percentage of rolling spermatozoa and the rolling frequencies were less in the 25-micron than the 100-micron slide preparations. Thus, the movement parameters of both ampullar and ejaculated spermatozoa were affected by the geometry of their observation chambers. This influence should be taken into account when observing sperm motility in vitro. It could also be important in vivo, where changes in sperm movement in response to epithelial surfaces might provide an advantage for reaching the cumulus mass. Ninety-eight percent of the motile ampullar sperm were observed to have acrosomes, including all spermatozoa found within the cumulus matrix.

Acrosome↗
PubMed1982

A study of the relationship of motile sperm numbers in cervical mucus 48 hours after artificial insemination with subsequent fertility.

The records of 159 women who underwent 561 cycles of donor insemination (AID) in the UCD artificial insemination program were analyzed in a study of the relationship of the numbers of motile sperm seen in the cervical mucus 48 hours after AID with subsequent fertility. The numbers of motile sperm were expressed on an integral rank scale (0 to 8). A relationship between the results and subsequent fertility was demonstrated. The distribution of the data on sperm numbers for fertile and infertile cycles were qualitatively and quantitatively different. The latter were consistently skewed toward low values, while the former were not. Overall, mean values were higher for conception cycles. Selective grouping of women to eliminate factors that could potentially have an adverse influence on fertility, such as pelvic abnormality, oligoovulation, or prior pelvic operation, increased the overall conception rate. However, they did not influence the relationship between low and high motile sperm numbers and subsequent conception.

Adult↗
PubMed1982

Flow permeation analysis of bovine cervical mucus.

Geometrical properties of the microstructure of whole bovine cervical mucus were studied. An experimental technique was developed for measuring the flow of fluid through the mucus microstructure in response to application or a prescribed external pressure gradient. The data obtained were analyzed in conjunction with a mathematical model of the hydrodynamics of the flow-permeation process. The sizes of typical interstices within the microstructure were calculated to be of the order of 1 micrometer, with typical macromolecular filament diameters being of the order of 100 A. These dimensions were interpreted as representative of an equivalent network giving rise to measured flow permeability. The values of filament size showed a strong experimental correlation with the solids content of the mucus.

Animals↗
PubMed1982

Differences in the movement of morphologically normal and abnormal human seminal spermatozoa.

Movement characteristics of human spermatozoa in fresh semen from 7 fertile men were studied using high-speed cinemicrography. Parameters that measured sperm swimming speed, flagellar beat frequency, flagellar beat shape, and the straightness of the swimming trajectory were obtained from frame-by-frame analysis of the cine films. In addition, each spermatozoon sampled for movement was also classified as being morphologically normal or abnormal, the latter being subdivided into the categories amorphous head, amorphous midpiece, elongated tapering head, piriform tapering head, megalocephalic and microcephalic. The morphological classification procedure involved direct reference of the sperm image on the screen of the cine film analysis console to metric morphological standards. Statistical analysis of the data investigated whether spermatozoa of different morphological types, as well as from different men, exhibited similar or dissimilar movement characteristics. It was found that morphologically normal spermatozoa swam faster and straighter, and exhibited higher beat frequencies than did morphologically abnormal sperm. These distinctions were most pronounced for spermatozoa with elongated or piriform tapering heads or amorphous midpieces.

Humans↗
PubMed1982

Alteration of cervical mucus by vanguard human spermatozoa.

Movement characteristics of 'vanguard' and 'following' human spermatozoa within cervical mucus were measured using high-speed cinemicrography. The data were applied to a mathematical model of the hydrodynamics of sperm-mucus interaction, using the methods of analysis of covariance and stepwise multiple regression. Vanguard spermatozoa swam more rapidly and more efficiently than did following spermatozoa, although the flagellar beat frequencies and amplitudes of the spermatozoa in the two populations did not differ. This distinction in sperm-mucus hydrodynamics could be due to reduced flagellar thrust and/or increased mucous resistance experienced by the following spermatozoa.

Cervix Mucus↗
PubMed1981

Sperm motility assessment by videomicrography.

A technically simple, inexpensive method is described for measuring objective parameters of sperm motility. The instruments involved are commercially available, home-oriented videotape equipment. Quantitative measurements of sperm motility are made directly from the video image and are facilitated by use of an analysis transparency that is applied as an overlay to the screen of the television monitor. A protocol is given for describing the motility of a suspension of human spermatozoa in terms of percentage motility, mean swimming speed, and the percentage of progressive sperm. A complete analysis can be done in 20 minutes or less. Examples are presented of videomicrographic assessment of the motility of human and bull spermatozoa.

Animals↗