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Biomedical subjects

J P Keating

Publications and source records attributed to J P Keating.

At least 19 recordsLinked to original sources
PubMed2003

Intermediate wave function statistics.

We calculate statistical properties of the eigenfunctions of two quantum systems that exhibit intermediate spectral statistics: star graphs and Seba billiards. First, we show that these eigenfunctions are not quantum ergodic, and calculate the corresponding limit distribution. Second, we find that they can be strongly scarred, in the case of star graphs by short (unstable) periodic orbits and, in the case of Seba billiards, by certain families of orbits. We construct sequences of states which have such a limit. Our results are illustrated by numerical computations.

Journal Article↗
PubMed2002

A multicentre retrospective audit of outcome of patients undergoing curative resection for rectal cancer.

AIM: This study describes the outcome of patients with rectal cancer treated in four New Zealand public hospitals before the advent of specialised colorectal units in order to provide a baseline against which any changes in management can be measured. METHODS: A retrospective review of case notes of patients who underwent resection of rectal cancer with curative intent over a period of 7-10 years up to 1995 in Christchurch, Wellington, Nelson, and Masterton Public Hospital's, was undertaken. Patients were identified from hospital records using a combination of methods (pathology data bases, clinical case mix data, operating logs and audit data). Metastatic disease was considered to be present if confirmed on histology or the clinical course of the patient was consistent with metastatic disease. Patients were excluded if there was perioperative evidence of metastatic disease or if they had transanal excision. Previously published results from Auckland and Dunedin Hospitals are compared. RESULTS: 524 patients with rectal cancer were identified who had undergone surgery with curative intent in the four hospitals. The overall permanent stoma rate was 37%. The overall 30-day mortality was 2.9%, five-year survival was 63% and local recurrence at five years was 26%. CONCLUSION: While low perioperative mortality and good long-term survival were achieved, there were high rates of local recurrence. These data are a baseline against which the impact of new approaches to curative resection for rectal cancer can be measured.

Colorectal Neoplasms↗
PubMed2000

Use of ultrasonic surgical aspirator in operative cytoreduction of pseudomyxoma peritonei.

Pseudomyxoma peritonei presents a unique challenge to the surgical oncologist. Residual gelatinous tumor with varying degrees of adherence always remains on the abdominal viscera after standard excisional therapy. Traditionally, this has been removed by "electroevaporation" with ball-tip diathermy, but this is associated with an extensive peritoneal burn and associated ileus. We describe the use of an ultrasonic surgical aspirator as a safe and efficient method of tumor removal in this condition.

Humans↗
PubMed1999

Complete genomic structure and mutational spectrum of PHKA2 in patients with x-linked liver glycogenosis type I and II.

X-linked liver glycogenosis (XLG) is probably the most frequent glycogen-storage disease. XLG can be divided into two subtypes: XLG I, with a deficiency in phosphorylase kinase (PHK) activity in peripheral blood cells and liver; and XLG II, with normal in vitro PHK activity in peripheral blood cells and with variable activity in liver. Both types of XLG are caused by mutations in the same gene, PHKA2, that encodes the regulatory alpha subunit of PHK. To facilitate mutation analysis in PHKA2, we determined its genomic structure. The gene consists of 33 exons, spanning >/=65 kb. By SSCP analysis of the different PHKA2 exons, we identified five new XLG I mutations, one new XLG II mutation, and one mutation present in both a patient with XLG I and a patient with XLG II, bringing the total to 19 XLG I and 12 XLG II mutations. Most XLG I mutations probably lead to truncation or disruption of the PHKA2 protein. In contrast, all XLG II mutations are missense mutations or small in-frame deletions and insertions. These results suggest that the biochemical differences between XLG I and XLG II might be due to the different nature of the disease-causing mutations in PHKA2. XLG I mutations may lead to absence of the alpha subunit, which causes an unstable PHK holoenzyme and deficient enzyme activity, whereas XLG II mutations may lead to in vivo deregulation of PHK, which might be difficult to demonstrate in vitro.

Base Sequence↗
PubMed1998

Vasculitis-induced colonic strictures: report of two cases.

PURPOSE: The clinical presentations of gastrointestinal involvement from systemic vasculitis are diverse. Colonic involvement from systemic vasculitis is unusual. We report the first case of a symptomatic colonic stricture associated with rheumatoid vasculitis and another associated with systemic lupus erythematosus. METHODS: The clinical, radiologic, and histologic features of two cases of symptomatic colonic strictures secondary to colonic involvement with vasculitis are described. The literature covering gastrointestinal involvement from vasculitis in these conditions is reviewed. RESULTS: Surgical resection of the colonic strictures was required in both patients and had a satisfactory outcome. CONCLUSIONS: These cases provide further evidence of the protean clinical presentations of intestinal involvement in systemic vasculitis. Although immunosuppression has been shown to be of value in the treatment of vasculitis affecting the gastrointestinal tract, surgical resection is required for established strictures.

Aged↗
PubMed1997

Are special investigations of value in the management of patients with fecal incontinence?

PURPOSE: The aim of this study was to determine whether special investigations significantly alter either the diagnosis or the management plan of patients with fecal incontinence assessed on the basis of a structured history and physical examination alone. METHODS: Fifty consecutive patients with fecal incontinence were prospectively studied in a tertiary referral clinic. Each patient was assessed by two clinicians who independently formulated a diagnosis and treatment plan based on the history and physical examination. The resulting 100 patient assessments were then compared with the final diagnosis and treatment plan formulated on completion of endoanal ultrasound, anal manometry, external sphincter electromyography, and defecating proctography. RESULTS: In the assessment of fecal incontinence, the addition of special investigations altered the diagnosis of the cause of incontinence based on history and examination alone in 19 percent of cases. The management plan was altered in 16 percent of cases. Special investigations were most useful in separating neuropathy from rectal wall disorders and in demonstrating the unexpected presence of internal sphincter defects and neuropathy. CONCLUSIONS: Even experienced colorectal surgeons will misdiagnose up to one-fifth of patients presenting with fecal incontinence if assessment is based on the history and physical examination alone. However surgically correctable causes of incontinence are rarely missed on clinical assessment.

Anal Canal↗
PubMed1997

Hydrodissection: an easy way to dissect anatomical planes and complex adhesions.

BACKGROUND: Sharp dissection of adherent tissues resulting from previous sepsis or surgery is frequently time-consuming and sometimes difficult. METHODS: The introduction of saline under pressure into the plane of dissection facilitates this task. RESULTS: Hydrodissection both creates and displays the correct plane between adherent tissues. CONCLUSIONS: This technique increases the safety and decreases the time spent in adhesiolysis in re-operative surgery.

Dissection↗
PubMed1997

Sclerosing encapsulating peritonitis after intraperitoneal use of povidone iodine.

BACKGROUND: The use of intraperitoneal povidone iodine as an agent for peritoneal lavage in colorectal surgery is controversial. Although it possesses a wide range of antimicrobial activity and is rapidly lethal to dissociated colorectal cancer cells in vitro, concern about its potential toxicity remains. METHODS: Two cases of sclerosing encapsulating peritonitis (SEP) following elective colorectal surgery are presented. In each case the peritoneal cavity was lavaged with an aqueous povidone iodine solution. The surgical literature on the intraperitoneal use of povidone iodine is reviewed. RESULTS: Significant morbidity resulted from the postoperative development of SEP in both of our patients. In one patient an ileo-anal pouch could not be fashioned following an initial colectomy, and in the second patient a small-bowel obstruction required a laparotomy and a period of intravenous nutrition before an oral diet could be tolerated. CONCLUSION: The use of povidone iodine for peritoneal lavage in colorectal surgery is to be cautioned against in concentrations of > 1%.

Adult↗
PubMed1997

Laparoscopic resection of the colon and rectum for cancer.

BACKGROUND: Laparoscopically-assisted resection for large bowel cancer is technically feasible. Sixty-six patients who had resection of the colon or rectum for cancer have been audited prospectively. METHODS: Clinical and pathological data were collected prospectively as part of the ongoing Concord Hospital colorectal cancer project. Patients were followed up for a median of 29 months. RESULTS: In 57 of 66 patients in whom laparoscopic resection was attempted the operation was completed laparoscopically. Three patients died from perioperative myocardial infarction. The median postoperative stay was 14 days. There was a high incidence of postoperative respiratory and cardiac complications. One patient developed a port-site metastasis. CONCLUSION: There was no obvious benefit from laparoscopically-assisted resection of large bowel cancer in these patients.

Aged↗
PubMed1996

The clinical and radiological features of cholecystocolic fistulae.

The clinical and radiological features of seven patients presenting with cholecystocolic fistulae are reviewed. The majority of the patients were elderly (age range 43-85 years, mean 70.7 years) and there was a female preponderance (6:1). The condition usually has a benign clinical course. Diarrhoea was the most common presenting symptom and the typical clinical features of gallbladder disease were absent. Cholangitis occurred in only one patient. The time between onset of symptoms and diagnosis varied from 1 week to 2 years (mean 22 weeks). In only one patient was the diagnosis of biliary-intestinal fistula suspected on the basis of the plain abdominal radiograph (Case 5). A diagnosis of cholecystocolic fistula was established by barium enema (5 cases), endoscopic retrograde cholangiopancreatography (ERCP) (1 case) and diagnostic laparotomy (1 case). The only cause identified in this series was acute or chronic cholecystitis.

Adult↗
PubMed1995

Psychological assessment of postdisaster class action and personal injury litigants: a case study.

The case study method is used to describe psychological assessments undertaken with victims of a combined natural/technological disaster for litigation purposes. A class action suit was filed in which the authors determined levels of traumatic stress in 27 plaintiffs as a group and relative to each other. The process was effective--the case was settled out of court in favor of the litigants. Individual litigants were satisfied with monetary awards received.

Adult↗