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Biomedical subjects

R J Swanson

Publications and source records attributed to R J Swanson.

At least 37 records · Page 2Linked to original sources
PubMed1988

Evaluation of semen parameters by means of automated sperm motion analyzers.

Fresh semen specimens from 46 patients and donors were evaluated for concentration, motility, velocity, and linearity using two different commercially available computerized sperm motion analyzer systems. Although no significant differences in measurement of concentration or motility were observed, significant differences in velocity and linearity were recorded. Fourteen cryopreserved/thawed samples were assessed with the same set-up parameters as fresh specimens. When discrepancies between manual and computer counts were noted, the authors changed the set-up parameters and evaluated 33 additional specimens. Again, no differences in concentration and motility, but significant differences in velocity and linearity were observed. Interlaboratory results must be correlated and standardization of set-up parameters of various analyzers is essential.

Autoanalysis↗
PubMed1987

New method of evaluating sperm morphology with predictive value for human in vitro fertilization.

A prospective study was planned to evaluate sperm morphology as a parameter to predict the fertilization outcome in an in vitro fertilization program. Couples applying to in vitro fertilization were admitted into this project when the sperm concentration was greater than 20 million per mL and motility greater than 30 per cent. Based on new strict criteria for evaluating normal sperm morphology, patients were divided prospectively into 2 groups. In group I (25 patients) normal sperm morphology was less than 14 per cent, and in group II (71 patients) normal sperm morphology was greater than 14 per cent, using a threshold established previously. Multiple regression analysis was used to evaluate different parameters: concentration, motility, and morphology against the dependent variables, fertilization, and cleavage. The only factor which was significantly correlated with fertilization and cleavage was normal sperm morphology (P less than 0.0001). The fertilization rate (per oocyte) and the cleavage rate were 49.4 per cent and 47.6 per cent in group I and 88.3 per cent and 87 per cent in group II (P less than 0.0001). The ongoing pregnancy rate per laparoscopy and per embryo transfer was 4 per cent and 5.5 per cent, respectively, in group I and 18.3 per cent and 18.5 per cent, respectively, in group II (no significant difference). This study demonstrates the value of analyzing sperm morphology using the criteria recommended in terms of predicting fertilization and perhaps pregnancy outcome. Patients can be better counseled and the probability of fertilization or no fertilization can be more accurately established. Furthermore a trend is shown in the pregnancy rate that may indicate the importance of the male genome in establishing a pregnancy.

Embryo Transfer↗
PubMed1987

A quick, reliable staining technique for human sperm morphology.

The evaluation of sperm morphology is still an important parameter in the diagnosis of the infertile male. Most techniques used for staining human sperm are very time-consuming. A routine stain used for determining differential count of leucocytes (Diff-Quik stain) was evaluated against the standard Papanicolaou stain. Morphology results from 20 duplicate semen smears using both staining methods were determined separately by 2 technicians using a blind protocol. No significant differences were observed when comparing the two staining methods (paired Student's t-test). The advantages of the Diff-Quik stain are: a) complete staining-to-reading time under 7 min, b) commercially prepared reagents, and c) case of staining procedure.

Humans↗
PubMed1985

Toxicity testing for human in vitro fertilization programs.

Using a mouse embryo culture system, several procedures and materials associated with human in vitro fertilization protocols were tested for potential toxicity. Also, quality-control assays were performed for media prepared by nine different human in vitro fertilization programs. Detrimental effects upon embryo development were observed when culture media were exposed to the following substances: surgical instruments sterilized with Cidex or Cidex-7 or sterilized with ethylene oxide after packaging in Nest Protector Packs, various brands of surgical gloves, and various synthetic materials being evaluated as possible needle or catheter "liners." Results from comparative testing of media and serum supplements prepared by different in vitro programs indicated a wide range in culture medium quality, as assayed by the ability of the reagents to support mouse embryo development. The importance of an animal model system available to all human in vitro programs for routine quality-control analysis and testing of novel uses of materials and innovative methods is discussed.

Animals↗
PubMed1985

Male factor evaluation in in vitro fertilization: Norfolk experience.

Thirty-three patients from the in vitro fertilization (IVF) program at Norfolk are critically reviewed. A battery of tests was designed and an endocrine investigation was carried out on these patients. The fertilization rate for preovulatory oocytes was lower than in the normal male population (39.6% versus 88.6%). When total concentration of sperm with rapidly progressive motility was less than 6 X 10(5), to fertilize several eggs together the fertilization rate was zero. No fertilization was obtained when the number of sperm with rapidly progressive motility recovered after the separation was less than 1.5 X 10(6). The hamster zona-free oocyte penetration test correlated well with the human IVF system. The other parameters investigated did not show good correlation. When fertilization was achieved, the results of the IVF procedure in the series reviewed rendered a 30.8% pregnancy rate per transfer in 26 transfers. Fifty percent of the pregnancies were normal (either ongoing or delivered). Thirty-seven percent were preclinical miscarriages, and 12.5% were clinical abortions. In the abnormal male population, higher concentrations of sperm per egg should be used for insemination for achievement of optimum fertilization rates. Once fertilization is obtained, the results do not differ substantially from the IVF population at large.

Animals↗
PubMed1984

Mouse embryo culture for screening in human IVF.

A system for obtaining and culturing mouse two-cell embryos is described, and its importance as a quality control assay and experimental model for human IVF programs is discussed. Over 2000 embryos from B6CBAF1 mice were cultured in either 115 preparations of Ham's F10 medium supplemented with 15% human fetal cord serum (H + FCS, a human IVF medium) or 18 preparations of Krebs' medium (a mouse IVF medium). No significant differences were noted in mean embryo development in the cultures of the two media. After 72 h in culture, the mean % morula + blastocyst development was 93% and 98% for H + FCS and Krebs', respectively. In 8% of the H + FCS cultures at least 75% of mouse embryos failed to grow to either morula or blastocysts by 72 h in culture, and fragmenting embryos were observed in 46% of the H + FCS cultures compared with 0% and 17%, respectively, of Krebs' cultures. Using this system, no significant differences were noted between control media (Krebs' or Ham's F10) and Ham's F12, Menezo's media, or Krebs' medium exposed to small pieces of a medical-grade silicone rubber semen collection device. However, exposure to several types of Vacutainer evacuated blood serum collection tubes did significantly impair the ability of Krebs' medium to support in vitro mouse embryogenesis.

Animals↗
PubMed1984

Hamster ova/human sperm penetration: correlation with count, motility, and morphology for in vitro fertilization.

In an analysis of 38 proven-fertile donor samples and 84 patient samples of either unproven fertility or suspected infertility, the number of hamster ova penetrated by human sperm (% HOP) was significantly different (p less than 0.05) between the donor and suspected-infertile groups. Lowest percent HOP rates; which were recorded for patients with oligozoospermia (less than 20 X 10(6) sperm per milliliter), were significantly different from donor rates (p less than 0.01). Sperm samples from 15 patients of unknown fertility were incubated with human eggs and were simultaneously incubated in the hamster ova-sperm penetration assay. All 13 patients fertilizing at least one human ovum also penetrated hamster ova at greater than 10%. The two samples failing to fertilize any human ova had one HOP above 10% and one below 10%. Interassay ranges were low over short periods of time (weeks), but the range was high (41%) for one individual when the SPA was performed months later. Fluctuations in % HOP over extended periods of time may be due to changes in male fertility status and not to unreliability of the assay.

Animals↗
PubMed1983

Methylation of proteins in photoreceptor rod outer segments.

A set of proteins in bovine rod outer segments is specifically methylated by S-adenosyl-L-methionine. The reaction can be demonstrated in the intact retina as well as in fragmented preparations of isolated rod outer segments. The apparent molecular weights of these proteins are 88,000, 61,000, and a subset between 21,000 and 26,000. The Mr = 88,000 protein is shown to be the alpha subunit of the rod outer segment cGMP phosphodiesterase by peptide mapping, two-dimensional gel electrophoresis, the ionic strength dependence of its interaction with the membrane, and immunoprecipitation by antiserum raised against purified phosphodiesterase. For each of these proteins, the incorporated methyl groups are hydrolyzed in alkali to yield methanol, indicating that the proteins are carboxymethylated.

3',5'-Cyclic-GMP Phosphodiesterases↗
PubMed1981

An indirect enzyme-linked immunosorbent assay (ELISA) for the detection and quantitation of antisperm antibodies.

Several recent comparative investigations using various assays to detect and quantitate levels of antibody to human spermatozoa have produced widely varying results. In an attempt to reduce test variability, an indirect enzyme-linked immunosorbent assay (ELISA) was devised to measure antisperm antibodies. A standardized protocol was adapted employing sperm adsorption to polystyrene microtiter plates, at a density of 10(5) sperm per well, serum and enzyme-conjugate incubation conditions at 37 degrees C for 60 min, and three ten-minute washes between incubations, using phosphate-buffered saline containing Tween-20. Using antihuman sperm antisera generated in rabbits, the ELISA was shown to yield significantly detectable antibody at dilutions of 1/16,384. The ELISA demonstrated approximately 89% reproducibility (ie, 100% minus the coefficient of variation) for an "intraassay" study wherein 300 determinations were performed on the same day on sperm from ten donors. However, when sperm from one donor were used in 30 determinations during ten assays over a six-month period, "interassay" reproducibility was approximately 51%. The ELISA was compared with macroagglutination, microagglutination, and immobilization tests, using rabbit antisperm serum and human sera from vasectomized males. Results of this study indicated that the ELISA was more sensitive, less subjective, and easier to perform than these other commonly used techniques.

Antibodies↗
PubMed1980

Laparotomy as a precipitating factor in the rupture of intra-abdominal aneurysms.

Previously asymptomatic aneurysms in ten patients ruptured within 36 days (mean, ten days) of a prior laparotomy. The laparotomy and associated intra-abdominal disease may have precipitated rupture of the unresected abdominal aneurysms by reduction of the collagen content of the aneurysm wall, thus making the wall weaker. The scar-like collagen fibers of an aneurysm wall provide the strength that permits the wall to resist rupture. There is a dynamic equilibrium between synthesis and lysis of this collagen. Lysis of collagen is enhanced by injury, such as laparotomy, and by nutritional depletion and local inflammation. Collagen lysis is greatest in the area adjacent to the injury, but also occurs at remote sites as well. Lysis is greatest during the first postoperative week, after which, in the absence of sepsis or starvation, synthesis exceeds lysis and the equilibrium is restored. A thin aneurysm wall may be weakened enough during this period of negative collagen balance to allow rupture.

Aged↗