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Biomedical subjects

J M Fitzpatrick

Publications and source records attributed to J M Fitzpatrick.

At least 163 records · Page 9Linked to original sources
PubMed1989

Renal injury and recovery in partial ureteric obstruction.

Partial ureteric obstruction was produced by insertion of an obstructing stent into the left ureter of 21 mongrel dogs and the duration of obstruction was varied as follows: Group A (n = 7) for 60 days; Group B (n = 7) for 28 days; Group C (n = 7) for 14 days. Intrapelvic pressure monitoring confirmed that obstruction had been produced by stent insertion and relieved by reimplantation of the left ureter following the designated obstruction period. The extent of recovery of renal function was assessed by creatinine clearance, with group C maintaining normal function, group B recovering 31% and group A recovering 8% of control function. Methyl-methacrylate extrusion casts of the renal microvasculature were made in group B and C kidneys and studied by scanning electron microscopy. During obstruction there was evidence of arteriolar constriction. These changes provide a morphological basis for the renal functional alterations and support the concept that post-obstructive renal failure is a vascular injury.

Animals↗
PubMed1989

The Whitaker test: experimental analysis in a canine model of partial ureteric obstruction.

The Whitaker test has been described as a means of reaching a diagnosis in equivocal upper urinary tract obstruction, but there has been conflicting evidence regarding the validity of this test. The present study assesses the reliability of the test in an experimental model which creates an accurate and predetermined degree of partial obstruction of the ureter. The Whitaker test was performed using the standard perfusion rate of 10 ml./min. in male adult dogs using a long-term indwelling renal intrapelvic cannula before and after application of ureteric obstruction, and after one month. Control animals underwent a sham procedure. Results of in vivo and in vitro perfusion studies were compared. Perfusion studies at multiple flow rates were also performed. The Whitaker test reliably detected the presence of ureteric obstruction and the degree of partial obstruction could be determined. Multiple flow rate studies did not significantly improve test results. Provoked pressures in the highest grade of obstruction were less than expected and this may be due to pyelovenous reflux.

Animals↗
PubMed1989

Extracorporeal shock wave lithotripsy with the Lithostar lithotriptor.

Early experience of extracorporeal shock wave lithotripsy (ESWL) using the Lithostar lithotriptor is reported; 145 patients underwent 185 treatments for 189 stones. Treatments were performed with either intravenous sedation and analgesia (90%) or general anaesthesia (10%). There were 123 renal calculi, 44 ureteric calculi and 22 staghorn calculi. Stone fragmentation was achieved with 1724 +/- 1035 shocks at 19 kv. The immediate stone fragmentation rate was 90% and the 3-month clearance rate 88%. Secondary treatments were required in 19% of patients and additional procedures in 17%. A comparison between stone size and the number of shock waves required to achieve stone fragmentation revealed a linear relationship. The Lithostar is a very effective second generation lithotriptor which can be used for renal, staghorn and ureteric calculi in situ, without manipulation.

Adolescent↗
PubMed1988

The predictive value of flow cytometric information in the clinical management of stage O (Ta) bladder cancer.

Two blind retrospective flow cytometric studies were performed on archival stage O (Ta) papillary grades 1 to 2 transitional cell carcinomas of the bladder to learn whether deoxyribonucleic acid histogram patterns predict disease recurrence and progression. All patients with aneuploid histograms as predicted experienced recurrent disease. In 20 of 28 cases of recurrent disease the ploidy pattern changed during recurrence. Because of this finding we predicted disease progression if 2 or more histograms in the sequence were aneuploid. Two-thirds (8 of 12) of those having more than 1 aneuploid tumor incident experienced invasion, while only approximately a third (6 of 16) lacking repetitive aneuploidy had invasion. Furthermore, of the patients with 2 aneuploid lesions half had progression within 1 year and two-thirds within 2 years after the second aneuploid lesion. Therefore, it appears that in this disease deoxyribonucleic acid histograms can provide prognostic information beyond that obtained from tumor grade and stage.

Carcinoma, Transitional Cell↗
PubMed1988

The effect of unilateral experimental testicular torsion on spermatogenesis and fertility.

Significant subfertility exists in patients following unilateral testicular torsion, implying bilateral testicular disease. Immunological activation has been detected after experimental torsion and the present study sought to demonstrate immunologically mediated effects on contralateral spermatogenesis following experimental torsion, as well as quantifying ipsilateral damage. Early and late effects of torsion on bilateral spermatogenesis were studied at 1 and 6 months in 10 groups each containing 20 rats. Gross and histological examination, direct immunofluorescence tests, vas deferens counts and copulation studies were performed. Severe ipsilateral damage was noted, even after brief torsion periods. No contralateral testicular effects, immunological or otherwise, were observed. Ipsilateral damage after torsion may have been underestimated. There is no damage to contralateral testicular exocrine function following unilateral experimental torsion.

Animals↗
PubMed1988

Liver volume measurements and three-dimensional display from MR images.

A method was investigated for measuring the volumes of human livers in vivo from magnetic resonance images and subsequently displaying these livers in three dimensions. Volumetric image sets of phantoms, healthy volunteers, and patients with cirrhotic livers were processed. Two image-processing approaches were compared for accuracy of liver measurements, intrasubject and interobserver variation, and speed of processing. Results indicated that both processing methods had a high degree of volume-measuring accuracy (within 8%), the interobserver measurements had a high coefficient of correlation (r = .9994), the intrasubject measurements had a low coefficient of variation (1.8%), and one method was four to five times faster than the other. The faster and easier of the two image-processing approaches provided satisfactory results for measuring liver volumes, but the slower approach provided more realistic-looking three-dimensional images of the liver.

Humans↗
PubMed1988

Effect of perivascular electromagnetic flow probes on pulmonary hemodynamics.

We determined the effect of perivascular electromagnetic flow probes (EMF) on pulmonary hemodynamics in acute experiments. In seven dogs placement of the EMF on the main pulmonary artery (MPA) increased pulmonary arterial pulse pressure by 25% (17.8-21.9 cmH2O, P less than 0.005) and mean right ventricular pressure by 12% (23.2-25.9 cmH2O, P less than 0.001) but did not alter heart rate, systemic blood pressure, mean pulmonary arterial pressure, or right ventricular end-diastolic pressure. This response was not abolished by local application of lidocaine to the MPA. In three cats input impedance was calculated from measurements of pressure and flow in the MPA. Impedance was calculated with flow measured using an EMF and ultrasonic volume flow probe (USF), which avoids the constraining effect of the EMF. When flow was measured with an EMF rather than a USF, there was a significant difference in the impedance spectra (P less than 0.001), but it was only apparent in the moduli greater than six harmonics. We conclude that the EMF does affect right ventricular afterload in acute experiments and alters the measured input impedance.

Animals↗
PubMed1988

Pathophysiological sequelae of hepatic artery ligation: an experimental study.

The effects of ligation of the proper hepatic artery were studied in 40 rats. The serum transaminase and bilirubin levels were elevated significantly at 24 h following surgery but had returned to normal by the 7th postoperative day. The serum albumin level was significantly reduced at 24 h and remained low for a further 2 weeks. There was no histological abnormality in the liver following hepatic artery ligation. It would appear that there is an early return to normal function following hepatic artery ligation.

Animals↗
PubMed1988

Experimental testicular torsion: fixation without parenchymal trauma.

Acute testicular torsion has been investigated using experimental models which either do not mimic torsion or cause parenchymal trauma. Valid conclusions regarding possible immunological activation cannot be made from such models. Techniques for experimental torsion in the rat are compared in this study to a standard venous occlusion model. Vascular dye injections and gross assessment were made at 0, 1 and 12 h. Testicular torsion of 720 degrees with fixation by a transmesorchial suture was the model which produced changes most similar to those in the venous occlusion model. This model causes torsion without parenchymal trauma and mimics acute testicular torsion more accurately than previously existing models.

Animals↗
PubMed1988

The vas deferens count: a new accurate method for experimental measurement of testicular exocrine function.

Clinical and experimental measurement of fertility presents difficulties in technique and interpretation of results. This study compared a new concept, the vas deferens count (VDC), with the standard electroejaculation method as a means of measuring testicular sperm output. Seventy-five Wistar rats in three groups (control, orchidectomy, torsion) underwent VDC and electroejaculation fertility analyses. The VDC was successful in all cases and gave rise to results showing acceptable variance and, in addition, measured unilateral testicular exocrine function in each case. Electroejaculation was found to be a less satisfactory technique. The VDC is a simple and accurate technique for measuring testicular exocrine function in experimental animals.

Animals↗
PubMed1988

Variable results of calcium blockade in post-ischaemic renal failure.

The effects of three chemically dissimilar calcium-blocking drugs were studied in experimental post-ischaemic renal failure, in the rat. After 45 min unilateral clamping and contralateral nephrectomy, post-ischaemic verapamil administration protected renal function (p less than 0.025), but flunarizine, either before or after ischaemia, was not beneficial. Following 60 min bilateral renal pedicle clamping, nifedipine administration was not beneficial. Verapamil was the only calcium-blocking drug which attenuated the post-ischaemic renal dysfunction. Calcium blockers which differ in their modes of action, differ in their ability to protect the kidney from ischaemia.

Acute Kidney Injury↗
PubMed1988

An evaluation of predisposing factors for testis cancer in Ireland.

All testis cancer in Ireland (1980-1985) was analysed (n = 240). Incidence was highest in young adults (5.8/10(5)/year in those aged 25-34 years) with a moderate level in the elderly (1.8/10(5)/year in those over 75 years). Associations elsewhere with maldescent and social class were confirmed but cryptorchidism (12%) was more common than expected. Significant infertility was not identified. Associations with urban domicile (77%, p = 0.001), mental handicap (2.8%, p less than 0.05), recent vasectomy (1.2%, p = 0.009) and certain occupations were observed.

Adult↗
PubMed1988

Non-seminomatous germ cell testis cancer in Ireland (1980-1985). Management, results and prognostic variables with relevance to national management protocols.

All non-seminomatous germ cell testis cancer in Ireland (1980-1985) was analysed (n = 131) and 3-year survival was: stage I = 95% (n = 58), stage II = 54% (n = 36), stages III and IV = 24% (n = 34). Countrywide results were not as favourable as those achieved in specialist units and this supports the development of a national strategy to maximise disease control. No management protocols existed during this study and the variety of approaches helped to identify the most suitable types of treatment in this broad context.

Clinical Protocols↗
PubMed1988

Physician-dependent prognostic variables in the management of testicular cancer.

A study of 246 cases of germ cell testicular cancer in Ireland between 1980 and 1985 confirmed that the personnel and the manner of management can significantly influence the outcome. Inadequate staging by omitting marker assays or CT scan reduced prognosis. Failure to use standard chemotherapy (PVB, BEP, POMBACE, VAB) or a reduced dosage diminished survival. Regular investigations are necessary during treatment, including marker assays, chest X-ray and CT scan. Frequent monitoring is important in later follow-up. Management by a urologist improved survival, especially if he was involved from the outset. The results also favoured the concept of combined management by a urologist and an oncologist.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1987

Primary non-obstructive megaureter in adults.

Primary non-obstructive megaureter is rarely first diagnosed in adult life. The clinical and radiographic findings in 11 adults presenting with this condition are reviewed. The commonest complaint was pain. In all cases the diagnosis was suggested by intravenous urography, which was usually the initial diagnostic test. Confirmation was aided chiefly by micturating cystography and retrograde pyelography. Cystoscopy was normal. The radiologist can make an early diagnosis in this condition, which requires no treatment, in the absence of complications.

Adult↗