Search PubMed⌕ Search

Biomedical subjects

M Bush

Publications and source records attributed to M Bush.

198 records · Page 11Linked to original sources

Effects of electroejaculation and ketamine-HCI on serum cortisol, progesterone, and testosterone in the male cat.

The influence of manual restraint, ketamine-hydrochloride anesthesia and electroejaculation under anesthesia on circulating levels of cortisol, progesterone and testosterone was examined in male domestic cats. In the first experiment, cats were anesthetized with ketamine-HCI (17.5 mg/kg of body weight) and serially bled (controls) or serially bled and electroejaculated. These animals showed signs of recovering from anesthesia within 45 to 60 minutes of ketamine-HCI injection. Average serum cortisol concentrations increased (P less than 0.01) over the 84-minute sampling interval in both the electroejaculated and control groups. Cortisol levels reached their maximum concentration in the electrically stimulated males immediately postelectroejaculation (95.1 ng/ml) and were significantly greater (P less than 0.01) than in the controls (36.1 ng/ml) at a comparable time. Maximal mean cortisol concentrations in the control group (62.8 ng/ml) occurred 54 minutes after the first blood sample and occurred together with the onset of anesthesia recovery. Mean testosterone levels did not differ between electroejaculated and control cats, but did decrease (P less than 0.05) between the first and last blood sampling in both groups. In the second experiment, cats were bled on the same time schedule as in Experiment 1, but were bled while awake and manually restrained, or else during a deeper plane of anesthesia induced and maintained with higher doses of ketamine-HCI (initial dose, 23 mg/kg). Mean serum cortisol levels were greater (P less than 0.05) during manual restraint (range, 36.3-41.1 ng/ml) compared to deep anesthesia (range, 16.7-25.8 ng/ml), but did not change over the 84 minute sampling interval in either group.(ABSTRACT TRUNCATED AT 250 WORDS)

Anesthesia↗

Formaldehyde-related antibodies in hemodialysis patients.

In a study of anti-N-like antibodies, we tested sera from 93 hemodialysis patients for hemagglutination reactions with untreated and formaldehyde-treated reagent red blood cells. Six of 22 sera from patients who had been dialyzed with formaldehyde-sterilized membranes had anti-N-like activity and 20 (91%) specifically agglutinated formaldehyde-treated red blood cells. Sera from 71 patients dialyzed with disposable membranes neither had anti-N-like activity nor agglutinated formaldehyde-treated red blood cells. The agglutination of formaldehyde-treated red blood cells by sera from hemodialysis patients was unrelated to MNU phenotypes and, therefore, identified a second serologic specificity, provisionally termed "anti-formaldehyde." "Anti-formaldehyde" was absorbed by and eluted from NN red blood cells as well as from formaldehyde-treated red blood cells regardless of MNU phenotype. All eluates and sera containing anti-N-like activity also agglutinated formaldehyde-treated red blood cells, typically after the addition of anti-human serum. These findings are consistent with the hypothesis that anti-N-like reactions of hemodialysis patients' sera represent cross reactions of formaldehyde related antibodies with N antigens of normal red blood cells.

Absorption↗

Rhinorrhea, ventricular radiopharmaceutical stasis and communicating hydrocephalus: evaluation by serial cisternography.

Spontaneous cerebrospinal fluid rhinorrhea has been known to occur in association with hydrocephalus. The specific pathophysiology which results in a potential communication between the cerebrospinal fluid space (subarachnoid space) and the nasopharynx is unknown. The relationship of CSF movement and rhinorrhea was evaluated in ten random source mongrel dogs. These data suggest that spontaneous CSF rhinorrhea may occur during the early developmental phase of communicating hydrocephalus in dogs. At this time radiopharmaceutical movement showed ventricular entry and clearing. When the lateral ventricles enlarged, ventricular radiopharmaceutical stasis was seen and the rhinorrhea disappeared. This suggests that CSF rkinorrhea may act as a compensatory mechanism which partially protects the CSF compartment to withstand the extra CSF during the early development of communicating hydrocephalus.

Animals↗

Teratospermia in domestic cats compromises penetration of zona-free hamster ova and cat zonae pellucidae.

The ability of spermatozoa to bind and penetrate zona-free hamster ova and the zonae pellucidae of domestic cat oocytes in vitro was compared between normospermic (greater than 60% structurally normal spermatozoa per ejaculate) and teratospermic (less than 40% normal spermatozoa per ejaculate) domestic cats. The effects of culture media (Biggers, Whitten, Whittingham [BWW] versus modified Krebs Ringer bicarbonate [mKRB]) and simple dilution (DR), ejaculate centrifugation, and either resuspension (NS) or swim-up processing (SU) on penetration also were examined. High percentages of structurally normal spermatozoa were bound to zona-pellucida-free hamster ova regardless of the morphological forms in the inseminant. Mean percent normal spermatozoa bound to ova in DR, NS, and SU sperm aliquots from teratospermic male cats were not different (P greater than 0.05) from similarly treated normospermic aliquots. However, the percent penetration of hamster ova by normospermic ejaculates (10.5%) was superior (P less than 0.05) to that of teratospermic ejaculates (2.8%). Although swim-up processing improved percent sperm motility, progressive motility, and normal morphology in teratospermic ejaculates (P less than 0.05), no difference was observed in ovum penetration among the DR-treated, NS-treated, and SU-treated spermatozoa (P greater than 0.05). Culture medium had no effect on sperm binding in the hamster assay, but ovum penetration rate by spermatozoa in the normospermic ejaculates was enhanced (P less than 0.05) using mKRB (13.5%) when compared with BWW (7.6%) medium. Spermatozoa from teratospermic cats were capable of binding and penetrating cat zonae; however, sperm-zona interaction (defined as percent of oocytes with spermatozoa binding to or penetrating into the zona) was different (P less than 0.05) between normospermic (65.3%) and teratospermic (24.2%) cats.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

Teratospermic and normospermic domestic cats: ejaculate traits, pituitary-gonadal hormones, and improvement of spermatozoal motility and morphology after swim-up processing.

Electroejaculate traits, testicular volume, and circulating FSH, LH, and testosterone concentrations were compared between two populations of domestic cats consistently producing either a high (greater than 60%, normospermic) or low (less than 40%, teratospermic) incidence of structurally normal spermatozoa/ejaculate. The effects of semen dilution in Biggers, Whitten and Whittingham (BWW) or modified Krebs Ringer bicarbonate (mKRB) medium and swim-up processing on sperm viability and duration of motility in vitro also were assessed. Ejaculate volume, percent sperm motility, sperm progressive motility, motile spermatozoa/ejaculate, testes volume, and mean serum FSH and LH concentrations were similar (P greater than 0.05) between normospermic and teratospermic cats. However, sperm concentration/ml of ejaculate was greater and circulating testosterone levels were lower in teratospermic males. Swim-up processing increased (P less than 0.05) percent sperm motility, progressive motility, and the number of structurally normal sperm cells recovered and also prolonged the duration of sperm motility in both cat populations. In teratospermic ejaculates, swim-up separation increased the proportion of morphologically normal spermatozoa recovered by more than two-fold. Diluting cat semen with either BWW or mKRB increased flagellar bending in both normospermic and teratospermic cats. The sperm motility characteristics of only the teratospermic ejaculates were influenced by medium type; mKRB increased percent sperm motility and progressive motility whereas BWW had no effect. Compared with undiluted raw ejaculates, the duration of sperm motility was improved 18- to 24-fold by diluting semen in either BWW or mKRB medium followed by swim-up processing. This study demonstrates that the electroejaculate characteristics of domestic cats vary markedly and that some males consistently produce high proportions of morphologically abnormal spermatozoa. Diminished serum testosterone concentrations and normal pituitary secretion of FSH and LH in teratospermic males suggest that there is an inverse relationship between gonadal androgen production and pleiomorphic spermatozoa in the domestic cat. The swim-up procedure is effective for recovering motile, structurally normal spermatozoa from teratospermic cats.

Animals↗

A change of course?

Explore the source record for details and available documents.

Curriculum↗

Quality assurance in brachytherapy: the role of the ICRU in achieving uniformity in dose and volume specification for reporting.

A quality assurance programme in brachytherapy implies a general consensus on the method of dose and volume specification for reporting. This in turn implies a consensus on certain definitions of terms and concepts. For several decades, the ICRU (International Commission on Radiation Units and Measurements) has been actively involved in an effort to reach a consensus between different brachytherapy centres worldwide, and to improve uniformity in reporting. The ICRU has prepared two reports containing recommendations for reporting brachytherapy treatments. The first, report #38 published in 1985, deals with intracavitary therapy in gynecology. The second deals with interstitial therapy, and is now in press. A summary of these two ICRU reports is presented here. Some definitions of terms and concepts are first recalled and discussed: Total Reference Air Kerma (TRAK), gross tumor volume (GTV), clinical target volume (CTV), treated volume, mean central dose, dose uniformity parameters, etc. Specific recommendations for reporting interstitial and intracavitary brachytherapy are then presented.

Brachytherapy↗