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Biomedical subjects

J M Fitzpatrick

Publications and source records attributed to J M Fitzpatrick.

At least 145 records · Page 8Linked to original sources
PubMed1992

Laparoscopic common bile duct exploration.

Laparoscopic cholecystectomy is now the standard approach to gallbladder disease. While laparoscopic cholecystectomy offers many advantages over the conventional laparotomy procedure one of its drawbacks is that a synchronous common bile duct exploration, for so long a cornerstone of management of choledocholithiasis, is not yet widely practised laparoscopically. Endoscopic sphincterotomy or open surgery, with their attendant hazards and morbidity, remain the most common approaches. A flexible choledochoscope with an operating channel may in future facilitate laparoscopic management of choledocholithiasis but as yet this is not widely available. We report the removal of a common duct stone by dormia basket extraction through the cystic duct at laparoscopic cholecystectomy.

Aged↗
PubMed1992

Simulation: current status in nurse education.

This paper suggests that in the light of recent developments in nurse education a review of available teaching and evaluation strategies is required. It is further suggested that the use of simulation for both teaching and evaluation purposes has much potential which has as yet to be fully exploited in nurse education.

Clinical Competence↗
PubMed1992

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↗
PubMed1992

A study of regional distribution of renal blood flow using quantitative autoradiography.

Quantitative autoradiography utilizing [14C]iodoantipyrine was used to measure regional renal blood flow in anesthetized rats. This technique allowed blood flow in any region of the kidney to be measured with a resolution of 100 microns. There was no significant difference between flow to polar and middle regions of the renal cortex [875 +/- 57 vs. 926 +/- 71 (SE) ml.100 g-1 x mm-1]. Areas of high optical density in renal cortex corresponded to peritubular capillaries. Mean cortical blood flow was three times greater than mean medullary blood flow. Outer medullary blood flow was uniform but significantly higher than inner medullary blood flow (272 +/- 16 vs. 45 +/- 7 ml.100 g-1 x mm-1; P < 0.001).

Animals↗
PubMed1992

A universal system for interactive image-directed neurosurgery.

Stereotactic methods confer great accuracy to intracranial target localization, but require strict adherence to a complex program of mechanical and computational maneuvers. A computerized, articulated, localizing 'arm' has been developed that frees the neurosurgeon of these constraints and provides a completely intuitive, 'user-friendly' interface. This universal system is independent of whatever localizing fiducial system is selected. The arm may be sterilized for intracranial use. A variety of intraoperative end effectors may be selected. The patient's CT/MR/PET scans are loaded into computer memory and a three-dimensional shaded surface wireframe diagram of the patient's head is displayed simultaneously with up to 3 independent sets of cross-referenced CT/MR/PET scan images on the intraoperative video screen. The arm's endpoint location and the directional vector are shown as cursors on the relevant scan slices, and change continuously as the surgeon moves the arm. Because the information is continuously updated, an unlimited number of targets and trajectories may be displayed throughout the operation. The arm has an ultimate design accuracy for end-point localization to within 0.1 mm throughout a target volume of 40 x 40 x 40 cm. The tested application accuracy of the first prototype model is 0.31 mm. In clinical use during 30 surgeries, its real-world application accuracy is 0.9 mm. This system provides stereotactic accuracy and universally compatible, intuitive, interactive operation.

Biopsy↗
PubMed1992

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↗
PubMed1992

The value of water-soluble contrast radiology in the management of acute small bowel obstruction.

A series of 127 consecutive patients with symptoms and signs and radiological features suggestive of acute small bowel obstruction underwent water-soluble contrast small bowel follow-through examination. A dose of 100 ml of Gastrograffin in adults, or 20-50 ml in children, was injected via a nasogastric tube and supine plain abdominal radiographs were taken at 30 min and 4 h after administration. If contrast passed to the colon a non-operative course was followed. If there was a clear cut-off in contrast level in the small bowel or if contrast failed to pass into the large bowel by 4 h, patients underwent laparotomy. Based on these radiological findings 15 patients (11.8%) underwent surgery and all had established small bowel obstruction at laparotomy. The remaining 112 patients were successfully managed conservatively. Water-soluble contrast radiology is safe, easy to use and to interpret, and is a major benefit in differentiating mechanical from other causes of small bowel obstruction. Our experience indicates that this underused technique is of significant value in identifying those patients who require urgent surgery.

Acute Disease↗
PubMed1992

The prognostic value of nucleolar organiser regions in colorectal cancer: a 5-year follow-up study.

Nucleolar organiser regions (AgNORs) are loops of ribosomal DNA which reflect the cellular activity or malignant potential of the cell and are identified by a specific staining technique. The purpose of this study was to assess the prognostic value of AgNORs in colorectal cancer and to compare it with other accepted prognostic methods. We studied 164 patients who were surgically staged for colorectal cancer and who had complete follow-up data available for 5 years. Using a highly specific silver staining and counting technique each patient was given an AgNOR score. There were 5 Dukes' C tumours, 108 were Dukes' B and 5 were Dukes' A. No cancer deaths occurred in patients with Dukes' A tumours. The incidence of well-differentiated, moderately-differentiated and poorly-differentiated tumours was 37.2%, 53.7% and 9.1%, respectively. Non-survivors had significantly higher AgNOR scores compared with survivors (mean value +/- SD, 14.2 +/- 0.9 vs 8.2 +/- 0.6, P less than 0.0001). In a regression analysis model AgNOR score was the most significant individual variable for predicting survival (chi 2 = 15, P less than 0.01) when compared with Dukes' classification, histological grade, tumour depth or vascular invasion.

Adult↗
PubMed1991

Pulmonary microvasculature in experimental acute haemorrhagic and oedematous pancreatitis.

The pulmonary microvasculature was examined in two experimental models of acute pancreatitis by scanning electron microscopy of microvascular corrosion casts. Haemorrhagic pancreatitis was induced in eight male Sprague-Dawley rats using an intraductal injection of 5 per cent sodium taurocholate. Oedematous pancreatitis was induced in seven male Sprague-Dawley rats using an intravenous infusion of supramaximal doses of caerulein (5 micrograms/kg per hour). The pulmonary vessels were cast using a polymer resin and the cast studied by scanning electron microscopy at 3 and 12 h in those with haemorrhagic and at 1 and 4 h in those with oedematous pancreatitis. Vascular abnormalities were present in both models at the initial study time with abruptly terminating vessels being more prominent in the caerulein model. At the later times, however, the abnormalities in the sodium taurocholate model were much more severe, with a substantial loss of vascular density, tortuosity and abrupt terminations of those vessels present. Microvascular abnormalities may be responsible for some of the pulmonary changes seen in oedematous and haemorrhagic pancreatitis.

Animals↗
PubMed1991

Changes in regional renal perfusion following ischemia/reperfusion injury to the rat kidney.

Post-ischemic renal failure is associated with a zone of vascular hyperaemia in the outer medulla of the kidney. The effect of this lesion on regional renal perfusion is, however, unclear. Acute unilateral renal ischemia was applied to four groups of ten adult male Wistar rats for a period of 60 min, followed by revascularisation for 0, 15, 30 or 60 min. The aorta was then clamped and Microfil was injected at a standard pressure to fill the renal vasculature. Gross and histological examinations of the renal parenchyma and vasculature were then performed. Regional renal Microfil perfusion was quantified by examination of unstained histological sections, giving rise to a vascular perfusion index (VPI) for each vascular region of the kidney. The VPIs were similar in control and ischemic kidneys that were not subjected to reflow (group 1). In contrast, the VPI was markedly decreased in the inner stripe and inner medulla in animals in which revascularisation had occurred (groups 2-4), and the vasculature in these regions was histologically shown to be packed with red blood cells. Post-ischemic renal failure is associated with hyperperfusion of the medulla resulting from blockage of the vasculature that occurs during revascularisation.

Acute Kidney Injury↗
PubMed1991

The role of 3 hour distal oesophageal pH monitoring in gastro-oesophageal reflux.

It has been suggested in the literature that an eight hour period of distal oesophageal monitoring is adequate for the diagnosis of reflux in symptomatic patients. The aim of this study was to investigate whether 3 hour intra-oesophageal pH-metry could be substituted for the eight hour test period without loss of sensitivity in the diagnosis of GOR. Twenty patients were tested, 10 of whom had classical De Meester symptoms of GOR and 10 asymptomatic patients served as controls. All were commenced on 3 hour ambulant pH monitoring of the distal oesophagus. This was followed by a separate period of 8 hour testing. Each test had a 50% supine time period. The following variables were determined: (i) number of reflux episodes (ii) number longer than 5 minutes (iii) longest episode of reflux, (iv) percent of time that pH was below 4. Results are analysed using the 'Esophogram' computer program. 8 hour monitoring resulted in a positive diagnosis of GOR in 10 of 10 patients, giving an overall sensitivity of 100%. 3 hour testing was positive in 8 patients (sensitivity of 80%). The best correlations were obtained when comparing total reflux episodes, and the percent of total time pH less than 4, but overall the tests correlate poorly for individual variables. None of the controls had positive 3 or 8 hour testing. We conclude therefore, that 3 hour pH metry may be a useful screening test to confirm symptomatic reflux, and can be performed within a single clinic visit. If negative, arrangements must be made for more prolonged monitoring.

Female↗
PubMed1991

Endoscopic management of common duct stones with laparoscopic cholecystectomy.

In the first year from October 1990 since starting the procedure 65 laparoscopic cholecystectomies were carried out on one surgical service. There were 4 planned open cholecystectomies and 8 laparoscopic procedures converted during the same period: 7 of these were in the first 3 months with only 1 of the last 53 being opened. Surgery was carried out during the same admission in 22 patients presenting as emergencies: acute cholecystitis (9), colic (6), pancreatitis (3), jaundice (4). Two patients had later laparotomies for complications; one patient bled from the umbilical stab and with ongoing peritonism had a pelvic haematoma drained on day 5 and a second was opened following a bile leak caused by a displaced cystic duct clip--both recovered uneventfully. Peroperative cholangiography was performed in 13 patients; 2 were positive (15%) and had ERCP papillotomy 3 days post op without complication. One patient who presented with pancreatitis had ERCP performed post-op without incident. Seven patients had laparoscopic cholecystectomy following papillotomy for common duct stones. The gallbladder was extracted per umbilicus in 45 (3 wound infections) and per right subcostal stab in 20 (no infections). Mean hospital stay was 48 hours (1-4 days) in uncomplicated cases. In conclusion, the learning curve is associated with higher conversion rates. Extraction through pliable hypochondrial muscles is easier and may be safer and less traumatic. Perioperative endoscopic papillotomy is safe and effective for choledochal stones.

Adult↗
PubMed1991

Time-varying pulmonary arterial compliance.

We tested the hypothesis that pulmonary arterial compliance (Ca) varies during the ventilatory cycle. Pressure and flow in the main pulmonary artery were measured in open-chest dogs under chloralose anesthesia (n = 12) with a positive-pressure volume-cycled ventilator. Input impedance was calculated from the pressure and flow waves of heart cycles obtained immediately after the start of inspiration (SI) and immediately after the start of expiration (SE). A lumped parameter model was used to calculate Ca from the input impedance spectrum of the main pulmonary artery. Three levels of positive end-expiratory pressure (PEEP) were used before and after meclofenamate (n = 6) or vagotomy (n = 6). Ca was significantly greater at SE than at SI at each level of PEEP. PEEP increased Ca at SE but not at SI. None of these changes was altered by meclofenamate or vagotomy, suggesting that these differences of Ca were due to passive mechanical effects rather than an active neurohumoral mechanisms. We conclude that Ca is time varying during the ventilatory cycle because it is altered by the dynamic increase of lung volume between SI and SE, but not with the quasi-static increase of lung volume induced by raising the level of PEEP. These changes of Ca were unaffected by vagal feedback or inhibition of cyclooxygenase. We suggest that the increased Ca just after the start of expiration may result from dynamic shifts of blood volume from the extra-alveolar to the alveolar vessels.

Animals↗
PubMed1991

Influence of prior orchiopexy on stage and prognosis of testicular cancer.

Thirty-four cryptorchid testis cancer cases were studied, of whom 9 patients had prior orchiopexy at the time of cancer diagnosis. Disease stage in this group was: stage I = 4, stage II = 1 and stages III and IV = 4 cases. Seventy-eight percent of these cases (n = 7) had non-seminomas; 4 of these patients died. In the uncorrected cryptorchidism group (n = 25), disease stage was: stage I = 12, stage II = 9 and stages III and IV = 4 cases. Of these cases, 64% (n = 16) had seminomas and 6 patients died. Orchiopexy marginally reduced the symptomatic interval for subsequent cancer and probably decreased the risk of seminoma development. Orchiopexy did not lead to a more favourable disease presentation or prognosis because of the adverse bias of advanced-stage non-seminomas in this group.

Adult↗
PubMed1990

The effect of caerulein induced pancreatitis on the hepatic microvasculature.

A three-dimensional morphological study of the hepatic microvasculature in caerulein induced oedematous pancreatitis was performed using scanning electron microscopy (SEM) vascular casts and transmission electron microscopy (TEM) of hepatocytes and hepatic sinusoids. TEM studies provided ultrastructural evidence of hepatocellular damage while SEM views demonstrated gross irregularity of the sinusoidal outline with abruptly terminating sinusoidal buds and extravasation of cast material, findings which were similar to those previously reported in the pancreas itself using the same model and which were supported by TEM cross-sectional views of the hepatic sinusoids. The results suggest that caerulein induced pancreatitis is associated with extrapancreatic microvascular damage which may be an important factor in the pathogenesis of extrapancreatic organ impairment associated with acute pancreatitis.

Amylases↗