Biomedical subjects

S T Mortimer

Publications and source records attributed to S T Mortimer.

26 records · Page 2Linked to original sources

PubMed1989

Analysis of parathyroid hormone in bovine parathyroid cysts.

Parathyroid cysts were found in 2-5% of beef steers and heifers while collecting parathyroids at a local abattoir. The cyst fluid contained parathyroid hormone (PTH), averaging 15 ng/ml of fluid. Reversed-phase high-performance liquid chromatographic (HPLC) analysis of the fluid using an acetonitrile-trifluoroacetic acid solvent system, followed by carboxyl-terminal specific PTH radioimmunoassay of the eluant fractions, revealed two major peaks of PTH immunoreactivity. The first eluted at approximately 25% acetonitrile, a position similar to the commercially available human carboxyl terminal fragment of PTH-(39-84). The second peak, at approximately 37% acetonitrile, corresponded to the elution position for bovine PTH-(1-84). The cyst fluid was tested for enzyme activity by incubation of 125I-labeled bovine PTH with cyst fluid for 30 minutes at 37 degrees C, which resulted in no fragmentation of the labeled peptide. Immunohistochemistry of the cells lining the parathyroid cyst indicated that they contained PTH.

Animals↗

PubMed1989

A technical note on diluting semen for the haemocytometric determination of sperm concentration.

A comparison was made of the use of either an SMI positive displacement pipette or an Eppendorf Varipette as the method of sampling 63 liquefied semen samples for volumetric dilution and haemocytometry to determine sperm concentration. The 95% range of the differences between the values obtained using the SMI and the Varipette with whole tips was from -46.9 to 63.8 x 10(6)/ml. With the Varipette tips cut off 12.5 mm from the end the 95% range was from -52.4 to 55.8 x 10(6)/ml. Previous work had shown that the 95% ranges of differences between duplicate determinations using the SMI pipette were from -7.2 to 6.9 x 10(6)/ml for two 1 + 19 dilutions, or from -16.0 to 12.1 x 10(6)/ml for 1 + 19 and 1 + 49 parallel dilutions. Therefore, since the Varipette had a far greater potential for error, a positive displacement pipette should be used when taking precise volume aliquots of human semen.

Humans↗

PubMed1989

Oocyte retrieval in an in vitro fertilization-embryo transfer program: comparison of four methods.

The records of 191 patients involved in 316 treatment cycles over 3 years in an in vitro fertilization-embryo transfer program were reviewed. Follicular aspiration, oocyte retrieval, pregnancy rates, technical difficulty, and complications were compared in four oocyte retrieval methods: 117 laparoscopic retrievals, 116 ultrasound (US)-guided percutaneous transvesical retrievals, 43 US-guided transvaginal retrievals, and 40 combined US and laparoscopic retrievals. The mean number of aspirated follicles (9.14) was greatest in the transvaginal retrieval group, but the ratio of oocytes to punctured follicles was not statistically greater in any of the groups. The overall clinical pregnancy rate per cycle was highest in the transvaginal retrieval group: 12 of 43 cycles resulted in pregnancy, or 27.9%. The number of delivered babies (16.3%) was also highest in the transvaginal retrieval group. US-guided transvaginal oocyte retrieval is recommended as the method of choice.

Embryo Transfer↗

PubMed1988

Influence of image sampling frequency on the perceived movement characteristics of progressively motile human spermatozoa.

Tracks of 30 progressively motile washed human spermatozoa were plotted manually from 200-Hz frame rate video recordings. Tracks at 100, 66.7, 50, 40, 33.3, 25, 20, 10, and 5 Hz were then constructed using every 2nd, 3rd, 4th, 5th, 6th, 8th, 10th, 20th, or 40th point. The 200-Hz tracks were analyzed by traditional manual methods, and all ten sets of tracks analyzed using a computer-assisted method ("Videomot," developed originally to analyze 30-Hz tracks) to eliminate observer bias. Progression velocity (VSL) remained constant under all analysis conditions. Average path velocity (VAP) also remained essentially constant, although Videomot was less reliable at high frame rates due to problems in determining the average path. Curvilinear velocity (VCL) was very frame rate dependent (the 25-Hz mean value was only 56.5% of that at 200 Hz), and Videomot was more accurate than manual analysis at 200 Hz. Values of the amplitude of lateral head displacement (ALH) were acceptable at most frame rates. At less than 66.7 Hz the inclusion of spurious curvilinear track deviations caused lower mean ALH values, and at 5 Hz ALH could not be measured since the track was essentially the average path. Beat/cross frequency (BCF) was also frame rate dependent; at high rates there was the same problem as with ALH measurements, while at less than or equal to 25 Hz the maximum BCF was restricted by the frame rate. We conclude that human sperm movement characteristics can be measured at frame rates ca. 30 Hz but only if the constraints affecting VCL and BCF values are understood and accepted. Finally, less than 10 Hz can only give values for VSL and, perhaps, VAP.

Humans↗

PubMed1988

Influence of system parameter settings on human sperm motility analysis using CellSoft.

The effect of changing CellSoft system parameter settings on measurements of motile sperm concentration and sperm movement characteristics (curvilinear and linear velocities, amplitude of lateral head displacement and beat/cross frequency) was investigated in semen. Specifically, the use of either four or 15 frames to distinguish motile from immotile cells was used in conjunction with a threshold curvilinear velocity of either 10 or 20 micron/s (recommended values: 4 and 10). In addition, a threshold for progressive motility based on linear velocity was also used by manual re-analysis of CellSoft Individual Cell Data printouts. Known reliable semen analysis methods or the analysis of manually reconstructed trajectories from videotape were used as standard methods for comparison. A curvilinear velocity threshold of 20 micron/s gave improved correspondence between CellSoft and standard methods for all characteristics evaluated. Whether a four or 15 frame setting was better varied with the measurement being made. However, using a linear velocity threshold to define the progressively motile sperm population provided the most acceptable values for sperm movement characteristics. Consequently, while substantial improvements in the measurements made by CellSoft can be obtained using different system parameters to those usually recommended, more reliable and certainly more useful information could probably be obtained if all analyses were performed on a defined population of progressively motile, and therefore potentially functional, spermatozoa.

Humans↗

PubMedDate not supplied

A critical review of the physiological importance and analysis of sperm movement in mammals.

The identification of human sperm hyperactivated motility has potential importance in sperm function tests, as well as in quality control assays and in reproductive toxicology investigations. However, relatively little is known about this phenomenon and the variety of definitions used for hyperactivation has led to a great deal of confusion as to its occurrence and physiological relevance. This presentation is a critical review of a number of aspects of hyperactivated motility, including its identification and potential role(s) in mammalian fertilization. The initial sections of the review consider the mechanisms involved in the development and maintenance of mammalian sperm motility, and the structural and functional changes in spermatozoa which occur during transport through the female reproductive tract. The methods available for the quantification of aspects of sperm movement are also discussed, with an historical overview of sperm movement analysis.

Animals↗

PubMedDate not supplied

CASA--practical aspects.

Explore the source record for details and available documents.

Electronic Data Processing↗

PubMedDate not supplied

Kinematics of human spermatozoa incubated under capacitating conditions.

Suspensions of seminal plasma-free human spermatozoa were prepared by swim-up from semen and studied using high magnification videomicrography after incubation under capacitating conditions for 1.5-2 h. Three subpopulations of capacitating spermatozoa showing different patterns of motility could be distinguished visually: forward progressive, transition phase, and hyperactivated motility. The purpose of this study was not to determine the relative proportions of spermatozoa in these three categories but to describe their movement characteristics. Manual track plotting and analysis allowed value derivation for the curvilinear, average path and straight-line velocities (VCL, VAP, and VSL respectively); for the three progression ratios of linearity (LIN = VSL divided by VCL X 100), straightness (STR = VSL divided by VAP X 100), and wobble (WOB = VAP divided by VCL X 100); and also for the amplitude of lateral head displacement (ALH) and the beat/cross frequency (BCF). Algorithms produced from these motion characteristics allowed distinctions to be made between cell motility patterns. Spermatozoa with straight-line velocity (VSL) greater than or equal to 40 microns/s, linearity (LIN) greater than or equal to 60% and amplitude of lateral head displacement (ALH) less than 5 microns were FP or non-hyperactivated. Tracks with curvilinear velocity (VCL) greater than or equal to 100 microns/s, linearity (LIN) less than 60% and amplitude of lateral head displacement (ALH) greater than or equal to 5 microns showed concomitants of hyperactivation. Classical hyperactivated tracks also showed straightness (STR) less than 60% and straight-line velocity (VSL) less than 30 microns/s.

Humans↗