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Biomedical subjects

J M Fitzpatrick

Publications and source records attributed to J M Fitzpatrick.

At least 127 records · Page 7Linked to original sources
PubMed1993

Temporal relationship of acinar and microvascular changes in caerulein-induced pancreatitis.

A study in rats investigated the temporal relationship between acinar cell changes and alterations in the local microvasculature in oedematous pancreatitis produced by administration of caerulein 5 micrograms kg-1 h-1. Samples were taken from experimental and control animals after 15 min, 30 min, 1 h and 2 h of caerulein infusion. Transmission electron microscopy showed ultrastructural acinar cell changes after 15 min whereas the earliest microvascular changes were seen after 30 min. Ultrastructural alterations in the acinar cells thus preceded local microvascular changes. Microvascular distortion appears to be a consequence and not a cause of pancreatitis in the caerulein model.

Animals↗
PubMed1993

Interleukin-1 dysregulation is an intrinsic defect in macrophages from MRL autoimmune-prone mice.

Macrophages (M phi) from pre-diseased autoimmune-prone MRL mice (both MRL/+ and MRL/lpr) dramatically underproduce the cytokine interleukin-1 (IL-1) in comparison to M phi from a number of normal strains. In this study we show that IL-1 dysregulation by MRL M phi is fully expressed at birth, and that this defect does not change with time or the development of disease. We also constructed adult irradiation chimeras (consisting of A/J-->MRL and MRL-->A/J mice), and show that M phi isolated from these chimeras display a pattern of IL-1 production indistinguishable from that of the donor strain controls. Moreover, when we constructed a mixed chimera (A/J + MRL-->A/J, the A/J and MRL M phi coexisting within the same animal retained their individual patterns of IL-1 production when isolated by negative selection. Taken together, these results provide the first substantive evidence for an intrinsic defect (IL-1 dysregulation) in M phi from MRL autoimmune-prone mice.

Age Factors↗
PubMed1993

The effect of stones on renal and ureteric physiology.

The effect of calculi on renal and ureteric function is the result of a complex sequence of pathophysiological events triggered by obstruction. The degree of impairment of renal function resulting depends on whether the obstruction is partial or complete, is unilateral or bilateral, is complicated by infection or not and how and when it is relieved. This review will look at these interacting factors and particularly on the effects of various treatment modalities ranging from open techniques to minimally and non-invasive interventions.

Animals↗
PubMed1993

Superficial bladder carcinoma. Factors affecting the natural history.

The natural history of superficial bladder carcinoma has an important bearing on the outcome of response to intravesical chemotherapy or immunotherapy. It may vary in different parts of the world, but it is essential that urologists know within their own practice how tumours respond to the initial transurethral resection. Many factors influence the natural history of superficial bladder carcinoma, and some, such as poor-grade, large tumour at presentation, smoking history, poor response to initial resection, and dysplasia or carcinoma in situ, should alert the urologist to introduce intravesical therapy at an early stage.

Administration, Intravesical↗
PubMed1993

In situ ESWL for ureteric calculi: the optimum treatment?

In situ ESWL for ureteric calculi is associated with good stone clearance rates but is it without significant morbidity? A review of 189 patients with single ureteric calculi (150 upper ureter, 39 lower ureter calculi) revealed an 89% stone clearance for upper ureteral calculi and 80% stone clearance for lower ureteral calculi. However 11% of patients with upper ureteral calculi and 20% of patients with lower ureteral calculi required additional intervention for complications or failed treatment. In situ ESWL may not be the optimum therapy for all ureteric calculi especially those in the lower ureter.

Adolescent↗
PubMed1993

Problem solving in nursing practice: application, process, skill acquisition and measurement.

This paper analyses the role of problem solving in nursing practice including the process, acquisition and measurement of problem-solving skills. It is argued that while problem-solving ability is acknowledged as critical if today's nurse practitioner is to maintain effective clinical practice, to date it retains a marginal place in nurse education curricula. Further, it has attracted limited empirical study. Such an omission, it is argued, requires urgent redress if the nursing profession is to meet effectively the challenges of the next decade and beyond.

Education, Nursing↗
PubMed1993

The relationship between nursing and higher education.

The paper explores the relationship between nursing and higher education with particular reference to the development of nursing degree programmes in the United Kingdom. The literature reveals that the contribution of nurse graduates to the profession has been examined to a limited extent: however, this has predominantly taken the form of follow-up studies, the majority of which were conducted in the 1980s. No empirically based work could be found which explores graduates' practice of nursing, the absence of which is significant in view of the more recent change in the conventional training programme, Project 2000, and the introduction of a number of 3-year nursing degree courses.

Attitude of Health Personnel↗
PubMed1993

The ureter in vitro: normal motility and response to urinary pathogens.

The effects of bacteria on in vitro ureteric contractility were studied, using a model which allowed selective exposure of organisms to the ureteric mucosa and smooth muscle, respectively. A cannula attached to a pressure transducer was ligated into the proximal lumen of 2.5-cm segments of canine ureter. The distal ureter was ligated to form a closed pressure monitored system, and the segment suspended in a 20-ml organ bath containing Krebs Henseleit buffer at physiological pH and temperature. Following onset of spontaneous activity, broths of Escherichia coli, Proteus mirabilis, Pseudomonas aeruginosa and Staphylococcus aureus were added to either the buffer solution or ureteric lumen in doses of > 10(6) organisms/ml. Experiments were repeated using heat-killed organisms, bacterial filtrates and E. coli endotoxin. Ureteric contractility was stimulated by organisms added to the buffer medium, but reversibly inhibited by bacteria placed in the ureteric lumen. Heat-killed organisms, endotoxin and live filtrates had no effect on normal motility when exposed to either the ureteric mucosa or muscularis respectively. These findings reflect the conflicting changes in ureteric motility seen in vivo when bacteria are administered systemically or directly into the ureteric lumen.

Animals↗
PubMed1993

Pharmacological options for the treatment of acute ureteric colic. An in vitro experimental study.

The effects of opiate and non-steroidal anti-inflammatory agents on the in vitro canine ureter were compared using a new model for the assessment of ureteric pharmacology. A pressure measuring catheter attached to a pressure transducer and pre-calibrated pen recorder was ligated into the lumen of 2.5 cm segments of normal canine ureter. The segments were immersed in an organ bath at physiological pH and temperature and spontaneous contractility was observed in 90% of them. Morphine had a spasmogenic effect on ureteric activity which was unaffected by naloxone. This effect was similar to that of histamine and prostaglandin F2 alpha and was abolished by chlorpheniramine but not by cimetidine. Pethidine produced a transient stimulation followed by inhibition of ureteric activity which was unaffected by naloxone. Both indomethacin and diclofenac produced an abrupt inhibition which was reversible with prostaglandin F2 alpha. These data suggest that pethidine or a non-steroidal anti-inflammatory agent may by virtue of their spasmolytic effects be a superior choice of therapy for the acutely obstructed ureter.

Acute Disease↗
PubMed1993

Extracorporeal shock wave lithotripsy induces the release of prostaglandins which increase ureteric peristalsis.

The aim of this study was to identify the changes in secretion of prostaglandins into the urinary tract as a result of treatment by extracorporeal shock wave lithotripsy (ESWL) and to determine their effects on ureteric motility. Sixteen patients with renal or upper ureteric calculi were studied. A peripheral blood and urine sample was collected immediately before and after ESWL, with further samples taken 24 h later. The following variables were assessed by radioimmunoassay:prostaglandin E2 (PGE2), prostaglandin F1 alpha (PGF1 alpha), and thromboxane B2 (TXB2). An in vitro canine study was then designed to study the activity of TXB2, PGF1 alpha and PGE2 on an isolated intact canine ureter model. Significant elevations of TXB2 were found immediately after ESWL in both serum and urine, which fell almost to pre-treatment levels by 24 h. PGF1 alpha levels showed significant elevations at 24 h but no immediate increase as seen with TXB2. In contrast, PGE2 levels were unchanged in the urine but significantly decreased in the serum. In vitro studies showed that both TXB2 and PGF1 alpha repeatedly produced an increased frequency of ureteric contraction. ESWL results in the release of prostaglandins from the urinary tract which are shown to cause increased ureteric peristalsis.

Adult↗
PubMed1993

Recovery of ureteric motility following complete and partial ureteric obstruction.

Complete and partial ureteric obstruction was created in 2 groups of 10 mongrel dogs by placing a ligature around, or inserting a fine bore plastic stent into, the lower end of the left ureter (Groups 1 and 2). After 4 weeks the ligature or stent was removed, a 2.5-cm segment of ureter was harvested for in vitro analysis and the ureter reimplanted into the bladder. Pelvic and ureteric pressures and motility were recorded before, during and after the period of obstruction via a subcutaneously placed nephrostomy tube. Pre-obstruction resting intra-ureteric pressure was 2.1 +/- 0.3 mm Hg (mean +/- SEM), with regular contractions 8.9 +/- 0.7/min of 36.2 +/- 1.2 mm Hg amplitude. After 4 weeks of obstruction, contractility was abolished in Group 1 but increased in Group 2, 71.5 +/- 3.3 mm Hg, with irregular multiphasic contractions seen following diuresis. Intra-ureteric pressure was 16.3 + 1.2 mm Hg in Group 1 and 9.3 + 1.2 mm Hg in Group 2. In vitro experiments confirmed the patterns of contractility seen in vivo. Eight weeks after reimplantation the ureter returned to normal rhythm and rate in Group 1, but increased contractility persisted both in vivo and in vitro in Group 2.

Animals↗
PubMed1993

Do not treat staghorn calculi by extracorporeal shockwave lithotripsy alone!

A review of 84 patients with triple phosphate (staghorn) calculi treated by extracorporeal shockwave lithotripsy (ESWL) revealed a 67% stone clearance at 6 months. Classification of calculi according to morphology showed a variation in stone clearance from 47 to 82%. A significant number of patients developed complications (25%) or required additional procedures (27%). ESWL monotherapy is not a suitable treatment option for most patients with staghorn calculi.

Adolescent↗
PubMed1993

Pancreatic atrophy: a new model using serial intra-peritoneal injections of L-arginine.

No simple rat model for chronic pancreatitis exists at present. A single dose of arginine has recently been shown to induce acute pancreatitis in rats. This study was designed to assess whether serial injections of arginine would induce reproducible chronic pancreatic damage. Forty rats received an intra-peritoneal injection of 500 mg per 100 g body weight of L-arginine followed by three injections of 250 mg per 100 g over 10 days. The rats were killed 24 h after each injection and at intervals of up to 6 months. Serum amylase levels were increased in the acute phase only. Examination of the pancreas at 24 h showed a severe oedematous pancreatitis. By day 5 there was up to 90% acinar destruction with adipose tissue replacement, although ductal, vascular, and islet cells appeared undamaged. These changes were present 6 months after injection. This is proposed as a new, simple, and reproducible method of inducing chronic pancreatic damage in the rat.

Animals↗
PubMed1992

The relationship between a nutritional index and acute physiology score in critical illness.

Prognostic indices derived from available physiological data (SAPS), complex nutritional and biochemical tests (PNI), grip strength and serum albumin were calculated in 16 critically ill patients receiving intravenous nutrition over a six week period. The aim was to compare these independently derived prognostic indices, to assess their response to feeding, and to determine suitability for use in Irish intensive care units. Mean SAPS (7.6 +/- 0.92), PNI (3.1 +/- 0.29), serum albumin (30.3 +/- 1.03 g/l) and grip strength (17.9 +/- 1.3%) were all suggestive of an "at risk" group. Significant associations were found between the accepted SAPS index and both PNI (r = 0.6, p < 0.001, n = 35) and grip strength (r = -0.68, p < 0.001, n = 44) but not with serum albumin. No consistent improvement was seen in response to feeding in any of the derived indices. The close correlation between prognostic indices derived from either physiological, nutritional or grip strength data in this study and the failure of prognostic indices to improve during hyperalimentation would support a common mechanism, e.g. endogenous mediators, for metabolic and physiological disturbance in critical illness. It suggests that the role of hyperalimentation is supportive rather than therapeutic and re-iterates the importance of managing underlying disease processes. Simple grip strength may be a useful alternative to complex nutritional indices.

Critical Illness↗
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↗