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Biomedical subjects

J Mulhall

Publications and source records attributed to J Mulhall.

12 recordsLinked to original sources

Fertilization and pregnancy using intentionally cryopreserved testicular tissue as the sperm source for intracytoplasmic sperm injection in 10 men with non-obstructive azoospermia.

Testicular tissue extraction (TESE) to obtain spermatozoa for use with intracytoplasmic sperm injection (ICSI) has recently been employed in patients with non-obstructive azoospermia. Standard protocol is to retrieve a new sample of testis tissue on the day of oocyte recovery. Unfortunately, approximately 30% of men will possess no spermatozoa in their tissue, making ICSI an impossibility. We investigated whether testicular tissue that was intentionally obtained well before any planned ICSI cycle and cryopreserved could then serve as an efficacious sperm source in a subsequent ICSI cycle. This study reports on 10 men with non-obstructive azoospermia who did have spermatozoa found within their testis tissue at the time of TESE and who chose to use their frozen samples as the source of spermatozoa for a later cycle of ICSI. In 19 cycles the overall fertilization rate was 48%. Embryo transfer occurred in 89% of cycles. Two couples have achieved pregnancy (one ongoing, one delivered). All patients except one had multiple vials of frozen tissue remaining following their first cycle. This approach is offered as an alternative to repeated testicular tissue sampling, as the availability of spermatozoa is assured prior to the initiation of ovulation induction. This tissue can be harvested at the same time as diagnostic biopsy, thereby minimizing the number of surgical procedures.

Adult

Morphological changes and alterations in regional intrarenal blood flow induced by graded renal ischemia.

A model of renal ischemia was used to study morphological changes and alterations in intrarenal blood flow. Renal artery blood flow was reduced from 120 to 20 ml./minute (normal 172 +/- 14) for 3 weeks. Morphological changes were assessed histologically, and by electronmicroscopy. Intrarenal blood flow was determined using microspheres. Flow rates less than 80 ml./minute resulted in a progressive loss of renal volume with arterial thrombosis and renal infarction at 20 ml./minute. Histological changes included loss of glomerular volume, tubular dilatation (60 ml./minute), tubular cast formation (50 ml./minute) tubular atrophy, interstitial fibrosis, arteriolar thickening (40 ml./minute) and glomerular hyalinization (30 ml./minute). Electronmicroscopy changes at 60 ml./minute (loss of glomerular microvasculature, unfolding of glomerular vascular tuft, appearance of blind ending vessels) progressed to disruption of glomerular architecture noted at 30 ml./minute. Narrowing of medullary blood vessels (60 ml./minute) and neovascularisation (40 ml./minute) was observed. Progressive ischemia decreased medullary, inner cortical and outer cortical blood flow (5.9 to 2.1 ml./minute/gm.) p less than 0.01, with a compensatory increase to the opposite kidney.

Animals

A new technique examines the connective tissue framework in normal testis and in testis cancer.

A method of cellular digestion known as Etching facilitated scanning electron microscopy (SEM) of the connective tissue framework in normal testis and in cases of testis cancer. The collagen in the seminiferous tubules in normal testis has distinct lamellae and a well-defined outer border. In the germ cell tumours examined, the tubular connective tissue appeared hypertrophied, the distinct outer border was maintained in a seminoma specimen unlike in a case of non-seminoma. In a specimen of non-germ cell lymphoma there was gross distortion of the tubular connective tissue. These apparent variations in the collagen framework may have implications regarding local tumour development.

Collagen

Change in barbiturate anaesthetic sensitivity as a prognostic indicator of electroconvulsive therapy outcome.

Barbiturate anaesthesia is modulated by brain noradrenergic (NA) function. As derangement of NA pathways is postulated to occur in depression, changes in anaesthetic sensitivity measured as producing loss of eyelash reflex were monitored in 29 depressed patients throughout a course of electroconvulsive therapy (ECT). Patients thus monitored were followed for 12 months after completing treatment. An increase in barbiturate induction dose over a course of ECT, indicating a decrease in anaesthetic sensitivity, was a powerful predictor of maintained wellbeing. All patients who increased their sensitivity to the anaesthetic either failed to respond to the course of ECT or relapsed within 12 months. The possible mechanism for this is discussed.

Anesthetics

Fears in hearing-impaired and normally hearing children and adolescents.

In this study the Revised Fear Survey Schedule for Children was administered to 138 hearing-impaired and 134 normally hearing youths. Although both groups expressed fear of potentially dangerous stimuli, significant differences in responding were evident towards other kinds of stimuli. Whereas hearing children were more fearful of failure and criticism, the hearing-impaired children were more afraid of the unknown, injury and small animals. Girls reported significantly greater levels of fear than boys thus confirming a well established research finding. Further, significant interactions were found between hearing status and gender. In contrast to previous findings, age was not related to self-reports of fear.

Adolescent

Setting the baseline parameters for clinical assessment of foot to ground contact using the Musgrave pressure plate system.

The Musgrave Pressure Plate System for the measurement of foot contact patterns comprises two fixed pressure plates constructed from arrays of load cells, interfaced to a BBC computer. Its main advantage is the ability to measure and analyse spatial distributions of contact pressures and their time dynamics, and to do this relatively inexpensively in a clinical setting. Its main potential disadvantage is that it can disrupt the natural gait pattern by the discipline in enforces on the foot placement. The eventual aim of the project of which this study forms the pilot phase, is to develop formal decision rules based on the analysis of a large number of normal subjects for the diagnosis of abnormal foot pathology and the evaluation of therapy, using data collected by a Musgrave system. The objective of this study is to set baseline norms, and to evaluate the system. The analysis is based on 100 normal subjects using selected parameters on foot contact pressure, contact area and time, available from the system. Several stages of the foot contact process are described in terms of the selected parameters. The results show clearly that even with a relatively small subset of the available recorded data on each foot plant, a wide range of descriptive information can be accumulated. Statistically significant differences were found between the right and left feet on most of the parameters considered. However, these differences were based on a large sample and are not large in absolute terms in many instances. Therefore the observed differences may be small compared to differences between normal and abnormal cases.(ABSTRACT TRUNCATED AT 250 WORDS)

Anthropometry

Maximum oxygen uptake utilising different treadmill protocols.

The study compared five treadmill protocols (four utilising a motorised, and one a non-motorised, treadmill) on maximum oxygen uptake. The five male and five female subjects, all actively engaged in training, were assigned the tests in random order. Statistical analysis revealed no significant differences between the five protocols for maximal oxygen uptake, maximum ventilation, maximum heart rate and blood lactate inflection point, relative to maximal oxygen uptake. Significant differences were observed between the 3' protocol with incline increments of 1.5% and all other protocols on time to exhaustion (p = less than 0.01) and maximum blood lactate levels (HLA, p = less than 0.05). The results indicate that the protocols used in this study did not significantly influence the maximum oxygen uptake attained.

Exercise Test

Epidural buprenorphine for pain relief after major abdominal surgery. A controlled comparison with epidural morphine.

In a controlled trial epidural buprenorphine was compared with epidural morphine as the sole means of analgesia after major abdominal surgery. Bolus injections of buprenorphine 60 micrograms in 10 ml or morphine 2 mg in 10 ml of normal saline were given on demand for the first 48 hours postoperatively. Both drugs produced significant reduction in pain scores as assessed by the linear visual analogue scale and both produced prolonged analgesia at this dosage, which could be extended by further 'top-ups'. The authors conclude that, for postoperative epidural analgesia, buprenorphine may be the opiate of choice and the reasons for this are discussed.

Adult

Seasonal changes in cyclists' performance. Part II. The British Olympic track squad.

In Part II of the study, the British Olympic track (sprint) squad cyclists demonstrated reductions in body fat index, % body fat and endomorphy (p greater than .05), increased Hb and PCV % (p greater than .05), and lowered HR at rest and in warm-up exercise (p greater than .05), but no change in leg power. Repeated interval sprints of short duration, maximal exercise on an "ergowheel" ergometer, at standardised power output, showed increased anaerobic index (p greater than .05) and acceleratory power (p greater than .01) but no change in sustained power output. Compared with "non-select" riders, a case study of the single "select" rider showed anthropometric differences in terms of lower height, weight, body fat index, % body fat and endomorphy, but enhanced mesomorphy and FEV %. Furthermore, the "select" rider demonstrated temporarily latent functional performance capabilities, in that increased anaerobic index, acceleratory and sustained power indices, as well as enhanced relative power output, were not identified until late in the competitive season.

Anthropometry

Seasonal changes in cyclists' performance. Part I. The British Olympic road race squad.

British Olympic road squad cyclists were monitored during the 1980 racing season to evaluate training for the Moscow Games. Riders demonstrated reductions in body fat index, % body fat and endomorphy (p greater than .05). Graded exercise, using a "Racermate" wind load simulator/racing cycle ergometer system, showed reduced cardiovascular demands to warm-up exercise, and increased cardiovascular index, VO2 maximum, aerobic/anaerobic threshold shifts during maximal exercise (NS), with no changes in gearing, equivalent road speed, absolute/relative power output and leg power. Compared with "non-select" riders demonstrated lower body fat index, % body fat and endomorphy (p greater than .05), higher Hb and PCV % (p greater than .05) and elevated neuroticism and extraversion (p greater than .05). Furthermore, "select" riders demonstrated lower HR and CV index during warm-up exercise (p greater than .05), and elevated CV index, VO2 maximum, aerobic/anerobic thresholds during maximal exercise (p greater than .05), resulting from higher gearing, equivalent road speed and absolute/relative power output (p greater than .05).

Anthropometry