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Biomedical subjects

W I Lee

Publications and source records attributed to W I Lee.

35 records · Page 2Linked to original sources
PubMed1983

Selection of human spermatozoa according to their relative motility and their interaction with zona-free hamster eggs.

Human spermatozoa were separated according to their motility by centrifuging semen on discontinuous Percoll gradients. Fractions of the gradients were examined for sperm motility, velocity, viability, morphology, bacteria, and sperm function using the hamster ova sperm penetration assay. The percentage of motile sperm increased from 40% to 60% motile sperm in 60% Percoll to 90% to 100% Percoll. Sperm velocity increased proportionately. Staining showed that greater than 90% of sperm in the 100% Percoll were alive and had normal morphology, and that only sperm cells were found in Percoll concentrations greater than 80%. Sperm isolated in the 80% to 100% Percoll fractions penetrated hamster ova much more frequently than sperm found in the 60% to 70% fractions or than sperm that had not been separated on a Percoll gradient.

Cell Separation↗
PubMed1982

Laser light-scattering study of the effect of washing on sperm motility.

The effect of washing on human sperm motility was measured by means of dynamic laser light-scattering spectroscopy. Semen samples from 24 fertile donors were diluted with Biggers, Whitten and Whittingham (BWW) medium and subsequently centrifuged at one of the following forces: 235 x g, 325 x g, 400 x g, 470 x g, 500 x g, 600 x g, and 800 x g. The duration of centrifugation was 8 minutes for the first wash, 6 minutes for the second wash, and 3 minutes for the third wash. Sperm motility was evaluated in terms of the root mean square swimming speed of the spermatozoa and the mean migration rate of washed spermatozoa in estrous bovine cervical mucus (BCM). It was found that sperm motility and viability were improved when semen samples were washed at 235 x g, even after three washes. However, washing at forces of 600 x g or more reduced sperm motility and also their ability to penetrate cervical mucus in vitro. Repeated washing at forces between 300 x g and 500 x g had little deleterious effect on sperm motility.

Cell Separation↗
PubMed1981

Sperm penetration into cervical mucus in vitro. III. Effect of freezing on estrous bovine cervical mucus.

The influence of the storages period on estrous bovine cervical mucus after it was stored in the freezing compartment of the laboratory refrigerator was evaluated by an in vitro sperm penetration test with human spermatozoa, laser light-scattering, and a spinnbarkeit test. Data obtained from the sperm penetration test were analyzed by a mathematical model that correlates the sperm motility with the sperm transport rate and the penetrability of the mucus. The tests showed that estrous bovine cervical mucus can be stored for up to 4 weeks at -12 degrees C without a change in its physical properties. The results of this study strengthen the suggestion that bovine mucus could be employed as a substitute for human cervical mucus.

Animals↗
PubMed1980

A stochastic model for oviductal egg transport.

A mathematical description of ovum transport based on Langevin's diffusion equation is presented. The proposed model is deduced from qualitative features of this phenomenon, not induced from numerical fitting of experimental data. We demonstrate that egg transport in the ampulla of the rabbit oviduct can be represented as a one-dimensional random walk in a field of external force. The application of the model to describe isthmic ovum and sperm transport on the basis of simple random walk process is also discussed. The present formulation identifies and characterizes the forces involved in the motions of the ovum and predicts specific alternatives for physiological regulation of egg transport in the oviduct.

Animals↗
PubMed1980

Sperm penetration into cervical mucus in vitro. II. Human spermatozoa in bovine mucus.

Human spermatozoa pentrate estrous bovine cervical mucus readily in vitro and maintain good motility and viability for a number of hours. They show pronounced unidirectional motion in mucus that has been aligned linearly. Data from tube preparations indicate that human spermatozoa from a given ejaculate travel more rapidly in estrous bovine mucus than in human midcyle mucus. They are prevented from penetrating luteal phase bovine mucus. The results are discussed in relation to a model of the molecular structure of cervical mucus, derived from laser light-scattering spectroscopy. In addition, it is suggested that bovine cervical mucus could be developed as a possible substitute for human cervical mucus in cases of infertility due to deficient endogenous mucus.

Animals↗
PubMed1980

Sperm penetration into cervical mucus in vitro. I. Comparative studies.

Comparative studies have been carried out on the behavior of human and bovine spermatozoa toward homologous cervical mucus in vitro. In both cases the degree of sperm penetration and the pattern of sperm motility were influenced in a characteristic fashion by prior manipulation of the mucus: the most rapid and extensive penetration, and pronounced unidirectional motion, were seen in mucus that had been aligned linearly. By contrast, spermatozoa from rabbits, guinea pigs, rats, and mice were largely prevented from entering either midcycle human or estrous bovine cervical mucus, regardless of its physical arrangement. The observations on sperm motility patterns and the degree of penetration are discussed in relation to a model of the molecular arrangement of cervical mucus, derived in our laboratory from laser light-scattering spectroscopy.

Animals↗
PubMed1979

Laser light-scattering study of the effect of progesterone on sperm motility.

It is known that progestins can induce in the secretory cells of the cervix the excretion of a mucus that is highly viscuos, scanty, and impenetrable to spermatozoa. Mucus of this type is similar to that excreted during the luteal phase of the normal human menstrual cycle and the cow estrous cycle. It is a natural sequence to ask the question, do progestins also have a direct effect on sperm motility? With dynamic laser light-scattering we measured the motility of freshly washed human spermatozoa and of spermatozoa in the presence of a progesterone, both in terms of their swimming speed distribution as expressed in the spectrum of scattered light. The swimming speed was significantly reduced when the concentration of progesterone was three orders of magnitude greater than that of the physiologic level. This finding confirms the finding in earlier biochemical studies that progesterone has a distinct spermiostatic effect. We suggest this answer to the above question: progestin-releasing contraceptive devices may act on spermatozoa directly as well as in the secretory cells of the cervix.

Animals↗
PubMed1977

Molecular arrangement of cervical mucus: a reevaluation based on laser light-scattering spectroscopy.

Evidence obtained from laser light-scattering spectroscopy suggests that the molecular arrangement of cow estrous cervical mucus is an ensemble of entangled random-coiled macromolecules rather than a cross-linked macromolecular network, the model heretofore widely accepted. This new model can account for the following phenomena: (1) The viscoelastic properties of the estrous mucus and human mid-cycle cervical mucus are the result of the way in which the glycoproteins are entangled. Variations of these properties during the reproductive cycle may simply be due to changes in the water content of the cervical mucus. (2) Penetration of spermatozoa in mucus may be entirely mechanical without involving any kind of enzymatic lysis of cross-links (this is supported by changes in the pattern of spermatozoa flagellation during sperm penetration of cervical mucus as shown in motion picture films). (3) The orientation of spermatozoa in the cervical muscus need not be due to the presence of 'channels' between micelles but simply to an artifact, the stretching or flow of the mucus, which orients the entangled macromolecules and thus facilitates the penetration of spermatozoa in an axis parallel to them.

Animals↗
PubMed1976

Laser light-scattering spectroscopy: a new application in the study of ciliary activity.

A uniquely precise and simple method to study ciliary activity by laser light-scattering spectroscopy has been developed and validated. A concurrent study of the effect of Ca2+ on ciliary activity in vitro by laser scattering spectroscopy and high speed cinematography has demonstrated that this new method is simpler and as accurate and reproducible as the high speed film technique.

Cilia↗
PubMedDate not supplied

Laser light-scattering study of the toxic effects of methylmercury on sperm motility.

An in vitro study was designed using the laser light-scattering technique to obtain further information on the dose-effect relationship of methylmercury on sperm motility. The technique provided a quantitative evaluation of sperm swimming speed. Semen samples were collected from normal male Macaca fascicularis monkeys by anal electroejaculation. Methylmercury was added to aliquots of sperm suspensions in BWW medium in doses of 10, 5, 2, and 1 ppm. After 3 hours, the relative speed was 35%, 59%, 69%, and 92% of the corresponding controls at doses of 10, 5, 2, and 1 ppm, respectively. The percentage of motile spermatozoa decreased significantly at 10 ppm. By microscopic observation abnormal motility was detected at 5 and 10 ppm, especially after 20 to 40 minutes. Head movement increased from side to side, and many spermatozoa developed coiled tails. The technique proved useful for defining the dose-effect relationship of methylmercury and sperm swimming speed.

Animals↗
PubMedDate not supplied

Intraarticular triamcinolone hexacetonide injection in children with chronic arthritis: a survey of clinical practice.

To assess the efficacy of the intraarticular steroid(IAS) injection in the management of arthritis and the possible related complications in children with chronic arthritis. We evaluated 11 children of chronic arthritis (4 girls and 7 boys), age of onset ranged from 2-13.6 years, who had persistent arthritis treated with IAS from November 1994 to June 1997. The results of injections showed that the beneficial effect was noted within one day to 2 weeks without significant adverse reactions, remission exceeding 6 months was seen in 10 of 11 patients (in 14 of 18 joints). According to subgroups of chronic arthritis, the remission rate of IAS injection in children with pauciarticular arthritis reached 100%. A significant fall in C-reactive protein (CRP) between pre- and post-IAS injection (p = 0.03), but there were no differences in hemoglobin (Hb), white blood cells (WBCs), thrombocytes (Plts), erythrocyte sedimentation rate (ESR) and osteocalcin level. No injection-related complications were found. In conclusion, the IAS injection was an effective and safe treatment in children with chronic arthritis with no obvious complications especially in pauciarticular arthritis.

Adolescent↗