PubMed Health⌕ Search

Biomedical subjects

D J du Plessis

Publications and source records attributed to D J du Plessis.

At least 55 records · Page 3Linked to original sources
PubMed1985

[Transmission electron microscopy as an aid in the management of infertile men].

Light microscopic evaluation of the semen of infertile men with sperm motility and morphological problems and Kartagener's syndrome does not always provide sufficient evidence for the cause of infertility. Transmission electron microscopy (TEM) was performed on selected primary and secondary male infertility patients to determine the specific causes (ultrastructural) of infertility. A final diagnosis could be given to patients who had had over the years (average 8 years) several evaluations of their semen without any definite reason being given for their infertility. With TEM of the semen, ultrastructural abnormalities of the spermatozoa as causes of infertility could be demonstrated which were undetectable with standard routine light microscopy.

Cilia↗
PubMed1985

Histological changes in the penis of the Chacma baboon--a model to study aging penile vascular impotence.

Light and scanning electron microscopy was performed on the penes of Chacma baboons to establish their suitability as animal model for studying vascular impotence. Analogous aging penile vascular changes were found in man, and a fibrous trabeculopathy with intertrabecular senechiae was demonstrated. Considering the corresponding changes, the Chacma baboon could thus be regarded suitable for studying the pathophysiology of aging penile vascular changes.

Aging↗
PubMed1984

The use of autologous 111In-labelled platelets and scintigraphy to illustrate enhanced platelet activity during erection in the chacma baboon.

The demonstration of thrombelastographic hypercoagulability in the penile blood during erection, and the accompanying deposition of fibrin onto the endothelial layer of the deep penile artery and trabecular surface inspired this investigation of the possible role that platelets might play in the process. The bloodpooling pattern in the penis during and after erection from electro-stimulation was studied in 9 male adult baboons (Papio ursinus) using in vivo 99mTc-labelled red blood cells and scintigraphy. Platelet activity was similarly investigated after administering autologous 111In-labelled platelets to the baboons. The results indicate an enhanced platelet concentration with respect to bloodpooling during erection, and an entrapment of platelets after erection.

Animals↗
PubMed1983

Standardization of radiorenography in dehydrated and rehydrated primates under laboratory conditions.

Radiorenography with 99mTc-labelled diethylenetriaminepentacetic acid ( [99mTc]-DTPA) was performed on chacma baboons (Papio ursinus) and vervet monkeys (Cercopithecus pygerythus) to establish the effects of various states of hydration on the data obtained from the DTPA-renogram. The renogram parameters, which can be related to certain aspects of kidney function, varied significantly with the degree of hydration. It is therefore imperative for clinically directed animal research projects on the urinary system to standardise the experimental procedure for radiorenography. A dehydration of 6 h followed by an hour IU rehydration period using 200 ml of a 0.9% NaCl solution on baboons under thiopentone sodium anaesthetic, was found to be the most suitable procedure for radiorenographic investigations in this primate model.

Animals↗
PubMedDate not supplied

Alpha-glucosidase activity and sperm motility.

We correlated the activity of alpha-glucosidase in seminal plasma with the motility and differential motility of sperm. Significant positive correlations were found between the alpha-glucosidase activity and both motility and the percentage sperm with good forward progression. This supports the use of alpha-glucosidase in semen as a marker of epididymal function and specifically of the development of motility.

Humans↗
PubMedDate not supplied

Impaired epididymal function in patients with detached ciliary tufts in semen: a preliminary report.

Low spermatozoal ATP concentration in the presence of high alpha-glucosidase activity may indicate efficient epididymal function. It was suggested that detached ciliary tufts (DCTs) originated from the epididymis. We compared the spermatozoal ATP concentration and alpha-glucosidase activity in semen of patients with DCTs to that of a control group. Higher ATP concentration and lower alpha-glucosidase activity were found in patients with DCTs in their semen compared to the control group. These results might probably point out impaired epididymal function and further support the proposed epididymal origin of these tufts.

Adenosine Triphosphate↗
PubMedDate not supplied

Influence of acetylsalicylic acid and metabolites on DU-145 prostatic cancer cell proliferation.

Conflicting reports have been published on the anti-tumour activities of acetylsalicylic acid in various cancers. Therefore, the effect of acetylsalicylic acid and its major metabolites has been studied on human prostatic carcinoma DU-145 cells. Investigations concentrated on the influence of acetylsalicylic acid, salicylic acid and salicyluric acid, on cell proliferation, DNA- and protein synthesis of DU-145 cells. DNA and protein synthesis determinations were done in vitro by [3H]thymidine and [3H]glycine incorporation, respectively. No effect on cell plating efficiency was observed, however proliferation studies showed that acetylsalicylic acid and salicylic acid inhibited cell growth (10 mM, 100% inhibition). No significant effect on cell proliferation was ascertained with salicyluric acid. Both DNA and protein synthesis were 40% inhibited by 0.1 mM acetylsalicylic acid. This study demonstrates that acetylsalicylic acid exhibits a significant influence on cell growth of prostatic DU-145 cells. These preliminary results may contribute to a better understanding of the anti-tumour capabilities of acetylsalicylic acid.

Aspirin↗
PubMedDate not supplied

alpha-Glucosidase, sperm ATP concentrations, and epididymal function.

It has been suggested that alpha-glucosidase may be a marker of epididymal patency and function. Spermatozoal ATP concentrations decrease during passage through the epididymis, indicating efficient maturation. We correlated sperm motility with seminal plasma alpha-glucosidase activity and spermatozoal ATP. The sperm motility correlation with alpha-glucosidase activity was significantly positive, and the sperm motility correlation with spermatozoal ATP was significantly negative. It appears that high-alpha-glucosidase activity and low-spermatozoal ATP were present in semen with good sperm motility and could possibly indicate efficient epididymal function.

Adenosine Triphosphate↗