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Biomedical subjects

J M Fitzpatrick

Publications and source records attributed to J M Fitzpatrick.

At least 91 records · Page 5Linked to original sources
PubMed1996

Laparoscopic-assisted rectopexy using a novel hand-access port.

Many surgeons who were ready converts to laparoscopic cholecystectomy did not translate the technique to more advanced procedures. There are several reasons: increased operating times, a steeper learning curve, concern for oncological efficacy, and the loss of manual tactile ability. As shown with this report on laparoscopic assisted rectopexy, many of these difficulties can be overcome using the IntromitTM while still maintaining the benefits of minimally invasive surgery.

Aged↗
PubMed1996

An automatic technique for finding and localizing externally attached markers in CT and MR volume images of the head.

An image processing technique is presented for finding and localizing the centroids of cylindrical markers externally attached to the human head in computed tomography (CT) and magnetic resonance (MR) image volumes. The centroids can be used as control points for image registration. The technique, which is fast, automatic, and knowledge-based, has two major steps. First, it searches the entire image volume to find one voxel inside each marker-like object. We call this voxel a "candidate" voxel, and we call the object a candidate marker. Second, it classifies the voxels in a region surrounding the candidate voxel as marker or nonmarker voxels using knowledge-based rules and calculates an intensity-weighted centroid for each true marker. We call this final centroid the "fiducial" point of the marker. The technique was developed on 42 scans of six patients-one CT and six MR scans per patient. There are four markers attached to each patient for a total of 168 marker images. For the CT images the false marker rate was zero. For MR the false marker rate was 1.4% (Two out of 144 markers). To evaluate the accuracy of the fiducial points, CT-MR registration was performed after correcting the MR images for geometrical distortion. The fiducial registration accuracy averaged 0.4 mm and was better than 0.6 mm for each of the eighteen image pairs.

Algorithms↗
PubMed1996

A universal method for geometric correction of magnetic resonance images for stereotactic neurosurgery.

Accurate stereotactic navigation depends strongly upon the spatial fidelity of the image used for registration. Clinically significant levels of geometric distortion are present in standard MR images, limiting their utility. A technique for correction of all geometric distortions in spine echo MR images was assessed in a prospective clinical trial of 19 stereotactic craniotomies. The Euclidean error in target registration between CT and MR was significantly reduced, from 3.833 +/- 0.992 to 1.986 +/- 0.605 mm. The results of this clinical trial support the incorporation of this MR image rectification protocol into standard clinical practice.

Evaluation Studies as Topic↗
PubMed1996

Combined androgen blockade is the treatment of choice for patients with advanced prostate cancer: the argument against.

The concept that patients with advanced prostate cancer will survive longer if treated by a combination of castration and the blockade of androgens of non-testicular origin cannot be substantiated. When all of the available studies are reviewed, meta-analysis does not show any significant improvement in mortality when the combined approach is used. Some studies have suggested that combined treatment is particularly useful in patients with minimal disease, or with a good prognosis; it must be remembered that these are smaller groups which have been taken from large numbers of patients in which the endpoint was observations on the larger group and not the small subgroup.

Androgen Antagonists↗
PubMed1996

Dysregulated cytokine expression in vivo in prediseased and diseased autoimmune-prone MRL mice.

Macrophages (mø) from prediseased autoimmune-prone MRL/ + and MRL/lpr mice produce markedly decreased levels of IL-1 in vitro in response to LPS. In contrast, tissues from diseased MRL/lpr mice overexpress IL-1 in vivo. To determine whether IL-1 underproduction in the MRL strains is solely an in vitro phenomenon, we compared in vivo cytokine mRNA expression from prediseased age-matched MRL/ + and MRL/lpr mice to that from normal BALB/c and C3HeB/FeJ mice. Like mø in vitro, whole organ RNA from the spleen, liver, and kidney of MRL/ + and MRL/lpr mice showed down-regulation of IL-1 RNA following intraperitoneal injection of LPS. This abnormality in inducible IL-1 expression was present in all MRL mice, irrespective of disease stage or the presence of the lpr gene. On the other hand, only diseased MRL/lpr mice displayed elevated and constitutive expression of IL-1 in their livers and kidneys. We suggest that inducible expression is most indicative of the intrinsic, or genetic, capacity of cells to produce cytokine, whereas constitutive expression reflects extracellular disease-related inflammatory stimuli present only in the diseased MRL/lpr strains. By restricting our studies to prediseased MRL mice, we have tried to eliminate the effects of disease and to focus on the predisposing genetic background. The existence both in vitro and in vivo of a defect in inducible IL-1 expression by prediseased MRL mice suggests that the molecular abnormality underlying this defect may be a part of this predisposing background to autoimmunity.

Animals↗
PubMed1995

Cardiorespiratory effects of laparoscopy with and without gas insufflation.

BACKGROUND: Patients who are undergoing laparoscopic procedures can present with a number of ventilatory and circulatory problems. The use of a gasless technique for performing a laparoscopy by using a mechanical lifting device may potentially avoid such problems. OBJECTIVE: To compare the cardiorespiratory effects of laparoscopy with and without gas insufflation. METHODS: Twelve adult pigs were randomized to undergo a laparoscopy by using either carbon dioxide insufflation or mechanical elevation. Full invasive monitoring was performed preoperatively and at 10-minute intervals throughout the operative period. Parameters that were measured included blood gas determinations, mean arterial pressure, pulmonary arterial pressure, pulmonary capillary wedge pressure, central venous pressure, cardiac output, stroke volume, and total peripheral resistance. RESULTS: Carbon dioxide insufflation unlike mechanical elevation led to a fall in PO2 and absorption of a significant quantity of CO2, resulting in hypercapnia, acidosis, and a consequent hyperdynamic circulation. CONCLUSION: These findings have significant implications for the use of CO2 insufflation for laparoscopy in patients with a compromised respiratory or cardiac status.

Animals↗
PubMed1995

Regional renal blood flow in normal and disease states.

Renal function is intimately dependent on renal blood flow. Alterations in either total or regional renal blood flow have major consequences for renal function. Through homeostatic mechanisms the kidneys are able to maintain relatively stable rates of flow over a wide range of perfusion pressures. A combination of neural, endocrine, exocrine and autocrine signals serve to regulate renal blood flow at both local and systemic levels. Alterations in the balance of these systems occur in the presence of certain pathophysiological conditions and an understanding of the subsequent changes in regional renal blood flow distribution aids in the understanding of the associated changes in renal function. The regulation and distribution of regional blood flow and the effects of surgical and pathophysiological conditions on these factors are reviewed.

Diabetes Mellitus↗
PubMed1995

Prospective evaluation of a composite scoring system for mammographically detected cytologically assessed impalpable breast abnormalities.

The aim of all breast screening programmes is a reduction in deaths from the disease. It is hoped that this can be achieved with minimal intervention in the patient cohort who do not have cancer. In this study we have assessed the efficacy of a combination of mammographic and cytological scoring systems in the evaluation of 208 women with screen-detected non-palpable breast lesions. All mammograms were scored 1-5 and those with a score of 3 or more required needle localization. A cytology score of 1 to 5 was generated for each patient according to a similar system and an aggregate score for each patient was achieved by the addition of the mammographic and cytology score. Ninety-three of the 208 patients had malignancy--the positive predictive value for mammography alone in this series was 45%. All 58 patients who had an aggregate score of 8 or greater had cancer. The 60 patients who had an aggregate score of 4 had benign disease on excision biopsy. We suggest that a 'wait and repeat mammogram' approach is appropriate in patients with grade 3 mammography and benign (grade 1) cytology. Patients with an intermediate aggregate score of 5-7 should have an excision biopsy and those with an aggregate score of 8 could have definitive surgery rather than excision biopsy. Application of this aggregate scoring technique would enhance the delivery of more appropriate surgery to a majority of patients with screen-detected breast abnormalities.

Biopsy↗
PubMed1995

Clinical problem-solving using video simulation: an investigation.

This paper examines the use of videotape simulation as a research method for the exploration of clinical problem-solving. The challenges posed and the strategies employed to overcome the difficulties encountered are discussed. The simulation forms part of a larger comparative study of outcomes of pre-registration nurse education programmes, commissioned by the English National Board for Nursing, Midwifery and Health Visiting.

Clinical Competence↗
PubMed1995

Obstetric health services in Far North Queensland: is choice an option?

In remote Far North Queensland, evacuation for mandatory hospital births saves lives. However, morbidity and mortality for mothers and infants remain high. Results from a retrospective study of deliveries over a one-year period showed significant differences in obstetric risk and outcomes among rural and urban Aboriginal, Torres Strait Islander and Caucasian women. Choices of birth place for remote residents were severely limited but those women with education and knowledge about how the system worked utilised options alternative to the regional public hospital. The findings from both the retrospective hospital sample and interviews among remote-area residents of Far North Queensland confirm the need to develop community-based perinatal services to reduce cultural and social barriers to clinical care.

Adolescent↗
PubMed1995

Prostate disease: management options for the primary healthcare team. Report of a working party of the British Prostate Group.

The prostate gland has attracted a remarkable increase in interest in the past few years. The two most common diseases of this gland, benign prostatic hyperplasia and carcinoma of the prostate, have been brought into greater prominence by new diagnostic methods, public interest, and a wider choice of surgical and non-surgical treatments. Uncertainty about the significance of these changes has occurred because of the rapidity of change, the profusion of statements, opinions and promotions, and the relatively little guidance available from the profession. Ten urologists and two general practitioners have reviewed the relevant evidence about these two prostate diseases and the newer diagnostic methods; their conclusions are summarised here. Management options and guidance on clinical practice are also discussed. Because of a number of unresolved diagnostic and management issues, detailed requirements for practice guidelines have not been specified.

Adult↗
PubMed1995

Phytotherapeutic agents in the management of symptomatic benign prostatic hyperplasia.

Phytotherapeutic agents constitute a large part of the market for the pharmacological treatment of symptomatic BPH. At present, these agents are being used on an empirical basis with some success in relieving symptoms. They have not been shown to have any effect on objective indices. Several agents are presently undergoing randomized trials.

Humans↗
PubMed1994

Stereotactic cytology in a regional breast-screening programme.

Stereotactic localization and fine-needle aspiration are new procedures for the management of non-palpable mammographic abnormalities. In this prospective study, stereotactically guided cytology with immediate reporting was performed before biopsy in a consecutive series of 166 patients with screen-detected non-palpable abnormalities. All specimens were obtained by multiple stereotactically guided passes with a 22-G Franzén needle and graded as: 1, acellular or inadequate; 2, benign; 3, atypical, probably benign; 4, probably malignant; or 5, malignant. After definitive surgery all tumours were staged according to the Union Internacional Contra la Cancrum classification. Of 71 patients with malignancy, 56 were correctly diagnosed by cytology before operation. Twelve patients with malignancy had grade 1 cytology and 50 of the 52 with grade 2 cytology had benign disease. This study confirms that stereotactic cytology is a valuable diagnostic test in a breast-screening programme.

Aged↗
PubMed1994

Renal haemodynamics and prostaglandin synthesis in partial unilateral ureteric obstruction.

Haemodynamic changes in partial unilateral ureteric obstruction (PUUO) may be related to altered prostaglandin synthesis. In 12 dogs the left ureter was partially obstructed for 5 weeks. In six dogs the ureter was reimplanted into the bladder and to investigate the effect of this procedure on the contralateral side the other six animals underwent ipsilateral nephroureterectomy. Renal blood flow (RBF) was measured by the distribution of radiolabelled microspheres. Changes in urinary prostaglandin (PG) concentrations were validated by renin activity using angiotensin I. Reduced left RBF during obstruction was associated with increased thromboxane A2 synthesis (P < 0.01). Increased RBF to the non-obstructed side was associated with elevated PGE2 formation (P < 0.05). Elevated angiotensin I levels (P < 0.01) corresponded to maximal increases in PG synthesis. Reimplantation of the obstructed kidney did not exert a direct effect on contralateral RBF or PG concentration. Haemodynamic changes in PUUO in vivo are associated with alterations in renal PGs.

Angiotensin I↗
PubMed1994

Proliferating cell nuclear antigen: a new prognostic indicator in renal cell carcinoma.

Renal cell carcinoma is a tumor, the prognosis and behavior of which remain poorly understood. Proliferating cell nuclear antigen levels have been shown to act as an independent prognostic variable in a variety of malignancies. Proliferating cell nuclear antigen was evaluated in 59 cases of renal cell carcinoma, and the results were correlated with existing clinicopathological variables and survival. Proliferating cell nuclear antigen index (percentage of tumor cells positive for proliferating cell nuclear antigen) did not correlate with stage, grade or ploidy. To assess survival, tumors with proliferating cell nuclear antigen indexes of greater than and less than 60% were compared. The 24 patients with a high index (greater than 60%) had a significantly worse survival than did 35 with a low index (less than 60%, p < 0.001). Therefore, the prognostic potential of proliferating cell nuclear antigen in renal cell carcinoma is promising and may be of clinical value in the management of patients with renal cell carcinoma.

Adult↗
PubMed1994

Radiotracer measurement of ureteric blood flow.

This paper describes a novel technique using the blood flow tracer C14-iodoantipyrine to measure ureteric blood flow in anesthetized Sprague-Dawley rats. The ureters were divided into five equal segments, and the blood flow was measured using a modification of the Fick principle. There was a gradient down the ureter with a significant difference between upper (159 ml./100 gm./min.) and lower (83 ml./100 gm./min.) ureteric segmental blood flows. This technique may allow the role of ureteric ischemia to be investigated in a variety of disease states.

Animals↗