Search PubMed⌕ Search

Biomedical subjects

L P Fielding

Publications and source records attributed to L P Fielding.

At least 37 records · Page 2Linked to original sources
PubMed1993

Multiple prognostic factors and outcome analysis in patients with cancer. Communication from the American Joint Committee on Cancer.

The authors report the establishment of a new Committee of the American Joint Committee on Cancer that has two objectives as follows: (1) to review the methods available to estimate outcome and (2) to study certain tumors to determine whether an expanded list of prognostic factors can be formulated into new prognostic systems that will have scientific value and clinical utility for treatment selection and staging.

Humans↗
PubMed1993

Inhibition of VIP-stimulated ion transport by a novel Y-receptor phenotype in rabbit distal colon.

Neurocrine, endocrine, and paracrine regulators are critical to the control of colonic secretion. These studies have investigated the inhibition of vasoactive intestinal polypeptide (VIP)-stimulated ion transport by peptide YY (PYY) and other Y-class effectors in rabbit distal colonic mucosa mounted in Ussing chambers. PYY decreased basal short-circuit current (Isc) but did not significantly change either basal Na+ or Cl- flux. PYY inhibited VIP-stimulated increases in Isc by up to 86% and abolished VIP-induced Cl- secretion. PYY decreased VIP-generated increases in Isc by a tetrodotoxin-insensitive mechanism. PYY inhibited cholera toxin-stimulated as well as forskolin-stimulated increases in Isc but failed to alter stimulation by 8-bromoadenosine 3',5'-cyclic monophosphate (8-BrcAMP). PYY decreased VIP-stimulated increases in tissue cAMP by 88% and forskolin-stimulated increases by 84%. PYY, neuropeptide Y (NPY), (Leu31,Pro34)-NPY, and pancreatic polypeptide (PP) all demonstrated potent inhibition of VIP-stimulated increases in Isc. PYY-(13-36) demonstrated little effect on VIP stimulation. Thus the rabbit distal colon possesses a novel Y-class receptor phenotype that demonstrates high affinity for all three PP-fold peptides, NPY, PYY, and PP.

Animals↗
PubMed1993

A double-blind trial of the clinical effects of pulsed electromagnetic fields in osteoarthritis.

OBJECTIVE: Further evaluation of pulsed electromagnetic fields (PEMF), which have been observed to produce numerous biological effects, and have been used to treat delayed union fractures for over a decade. METHODS: In a pilot, double-blind randomized trial, 27 patients with osteoarthritis (OA), primarily of the knee, were treated with PEMF. Treatment consisted of 18 half-hour periods of exposure over about 1 month in a specially designed noncontact, air-coil device. Observations were made on 6 clinical variables at baseline, midpoint of therapy, end of treatment and one month later; 25 patients completed treatment. RESULTS: An average improvement of 23-61% occurred in the clinical variables observed with active treatment, while 2 to 18% improvement was observed in these variables in placebo treated control patients. No toxicity was observed. CONCLUSION: The decreased pain and improved functional performance of treated patients suggests that this configuration of PEMF has potential as an effective method of improving symptoms in patients with OA. This method warrants further clinical investigation.

Double-Blind Method↗
PubMed1992

The future of prognostic factors in outcome prediction for patients with cancer.

The anatomic description of the extent of tumor spread (tumor staging) assists clinical management, facilitates communication among physicians, is an essential part of randomized controlled trials, and may help in the counseling patients and their families. However, in recent years, additional "prognostic factors" have been defined, many of which assess or reflect the biologic behavior of malignant neoplasms. Other measures of tumor biochemistry address the natural history of neoplastic development and often are included in a discussion of new prognostic factors. This review article summarizes current knowledge and thinking related to tumor prognostic factors in four areas by providing: (1) a definition and principles of anatomic spread of tumor (staging) and some suggestions for improvement, (2) a description of some examples of additional factors of prognostic significance, (3) some statistical methods to evaluate prognostic factors, and (4) an examination of the possible future of summary statements of outcome (i.e., prognostic indexes).

Biomarkers↗
PubMed1992

Randomised controlled trial of adjuvant chemotherapy by portal-vein perfusion after curative resection for colorectal adenocarcinoma.

About half the patients treated with curative resection for colorectal cancer do not survive long-term. Adjuvant chemotherapy given during and after surgery may prevent hepatic metastases and improve patient survival. In patients with colorectal cancer, we have done a multicentre, randomised controlled trial comparing five-year survival after intraportal infusion of fluorouracil (1 g per day) plus heparin (10,000 U per day) (130 patients) or heparin alone (123) during curative resection and for 7 days thereafter, or after resection alone (145). There was no reduction in liver metastasis or increased overall survival advantage in either active-treatment arm of the study. However, patients who had stage III, Dukes' C (lymph-node-positive) tumours resected and were treated with fluorouracil plus heparin had a significant (p less than 0.03) survival advantage of about 16% compared with surgery-only controls. Further study of intraportal infusion of chemotherapeutic agent as adjuvant treatment to surgery in patients with colorectal cancer appears worthwhile.

Adenocarcinoma↗
PubMed1992

Identification of preventable trauma deaths: confounded inquiries?

The published evaluation of methods for identifying preventable trauma deaths contains many unstudied confounding factors. To investigate the reliability of methods for identifying such preventable deaths, we compared three consensus systems using separate five-member general review panels assessing 20 non-central nervous system fatalities: panel A, independent judgments; panel B, discussion of all cases preceding individual judgments; and panel C, independent judgments followed by discussion and equivocal case reassignment. The Kappa concordance index was low for all methods (method A, 0.20; methods B and C, 0.40). Of the 11 deaths judged preventable by at least one panel, only one death was judged preventable by all three panels. Consensus agreement (four of five assessors) was 20% for panel A, 45% for panel B, and 10% for panel C (difference between panels B and C, p less than 0.03). In panel C, discussion affected the rate of equivocal case designation from 30% to 5%. Thus different consensus methods yielded different results. We conclude that individual case review can be severely flawed and therefore should not be used to measure institutional quality of patient care. We recommend that assessment of institutional performance should be based on objective evaluation methods, which require the study of patient population outcomes, rather than on subjective methods in which individual cases are reviewed.

Confounding Factors, Epidemiologic↗
PubMed1991

Vascular responsiveness in obstructed gut.

Multiorgan system failure due to hypotension and sepsis is an important cause of death in patients with bowel obstruction. We have investigated the pathophysiology of this entity in an animal model. After 5 days of bowel obstruction, blood flow in the superior mesenteric artery was measured with and without Pitressin and norepinephrine given in separate experiments. In controls, Pitressin in moderate dosages caused a substantial fall in gut blood flow, which was not seen in obstructed animals (blood flow reduction 52 percent vs. 11 percent in sham and obstructed animals respectively, P less than 0.01). Similarly, norepinephrine infusion had less of an effect on gut blood flow in obstructed animals (blood flow reduction 79 percent vs. 58 percent sham vs. obstructed animals (P less than 0.05). Thus, both agents had dose-related effects on gut blood flow, which was maintained at a higher level throughout the drug infusion periods in the bowel of obstructed animals, demonstrating that splanchnic flow is less responsive to vasoactive drug infusion under these experimental conditions. Because splanchnic vasoconstriction is an important feature of normal hemodynamic homeostasis, we suggest that these results may help explain some aspects of the pathophysiology of multiorgan failure caused or worsened by systemic hypotension seen in bowel obstruction.

Animals↗
PubMed1991

Behavioral disturbances in children after trauma.

The psychological effects of nonneurologic trauma on children are poorly recognized. We hypothesized that physical trauma in children, with or without head injury, would result in substantial and persistent psychological and behavioral abnormalities. Using a short telephone survey followed by a detailed behavioral checklist, we studied psychobehavioral dysfunction in children who had experienced trauma either with or without minor head injury (n = 40 each) as well as in a comparative group of children after emergency appendectomy (n = 80). Substantial behavioral disability was identified by the detailed checklist in 35% and 28% of children without and with head injury, respectively, but in none after appendectomy. Dysfunctions included phobias, major scholastic difficulties, rage attacks, and episodic depression that continued for a long period. Even in the 67% of children who eventually fully recovered, the duration of symptoms after the time of injury was an average of 19 months. Demographics, socioeconomic status, severity of injury, and length of hospitalization did not correlate with dysfunction, and these traumatized children's siblings had no reported history of trauma or psychological difficulties. Thus, parental opinion about behavioral dysfunction appears sensitive and specific and is therefore a useful screening index. These results suggest that injured children, even after minor trauma, may suffer substantial and long-lasting behavioral changes to a degree hitherto unrecognized.

Appendectomy↗
PubMed1991

Acute perforated diverticulitis: primary resection and anastomosis?

Surgical management of patients with acute colonic diverticulitis is evolving from multiple towards single operations. The patterns of presentation and treatment of 146 patients with acute perforated diverticulitis have been reviewed (1983-1988) using the Hinchey classification system (Stages I-IV). This paper focuses on the six patients who presented with fecal peritonitis (Stage IV disease), half of whom were treated by primary resection and anastomosis and the remainder by a Hartmann procedure. The mean length of stay was 18.7 +/- 7.9 days and 12.7 +/- 4.8 days with a mortality of zero and one, respectively. These data suggest that in selected patients who present with perforated diverticular disease, primary resection with anastomosis offers a possible alternative to other operative management. The presence of fecal peritonitis should no longer be considered an absolute contraindication to immediate bowel reconstruction. Furthermore, we suggest that this decision be based on the relative absence of concomitant disease, a satisfactory response to preoperative resuscitation, the availability of a surgeon experienced in colonic surgery, and attention to postoperative management.

Acute Disease↗
PubMed1990

Survey of residents' attitudes toward reform of work hours.

Traditional work schedules of surgical residents have been cited as a factor that negatively influences residency education and the quality of patient care. As an adjunct to the formulation of recommendations for the development of the environment for general surgery training, the New England Association of Program Directors in Surgery set out to sample the attitudes of surgical residents in New England relative to their perceived need to reform work hours. Seventy-two percent of the residents thought there was a need for some level of resident work schedule change. The major variable that correlated with this opinion was the reported amount of sleep that a resident needed before returning to work after a 24-hour shift. The ultimate effect on education, patient care, and fiscal resources of these potentially sensitive changes remains to be determined.

Adult↗
PubMed1990

Neuropeptide Y inhibition of vasoactive intestinal polypeptide-stimulated ion transport in the rabbit distal colon.

We have studied the effect of neuropeptide Y on basal and vasoactive intestinal polypeptide-stimulated changes in the short-circuit current of strips of colonic mucosa from New Zealand white rabbits mounted in Ussing chambers. When administered to the basolateral surface, neuropeptide Y is found to decrease basal short-circuit current. Neuropeptide Y inhibits vasoactive intestinal peptide-stimulated increases in short-circuit current in a concentration-dependent fashion by a tetrodotoxin-insensitive mechanism. Also, neuropeptide Y inhibited increases in short-circuit current produced by direct stimulation of adenylate cyclase with forskolin. Furthermore, neuropeptide Y prevents vasoactive intestinal peptide-stimulated increases in tissue cyclic adenosine monophosphate levels. These results indicate that neuropeptide Y administered to the basolateral membrane inhibits vasoactive intestinal peptide-stimulated short-circuit current changes by a tetrodotoxin-insensitive mechanism that decreases tissue levels of cyclic adenosine 3',5'-monophosphate.

Animals↗
PubMed1990

Large bowel cancer: the effect of perioperative blood transfusion on outcome.

Perioperative blood transfusion has been reported to adversely affect survival in cancer patients, but the evidence is inconclusive and may be an epiphenomenon. From the Large Bowel Cancer Project, 961 patients who underwent curative resection and left hospital alive have been reviewed to compare the effect of perioperative blood transfusion on outcome; 591 patients (61%) had been given a blood transfusion while 370 (39%) had not been transfused. Some clinical variables were equally distributed between the two groups; ie age, sex, obstruction, perforation, tumour differentiation. Three other variables known to influence patient prognosis were not equally distributed, ie tumour site, Dukes' stage and tumour mobility. Patients with tumours of the rectum and rectosigmoid, with Dukes' stage C lesions and with some degree of tumour fixation were more likely to have received blood transfusions. Using the logrank method of multivariate analysis to allow for differences in distribution of all those variables known to affect prognosis, there was no survival disadvantage for those patients who had received perioperative blood transfusion. Furthermore, there were no overall differences between the two groups of patients in their risk of developing local tumour recurrence or distant metastases. The distribution of metastases differed: in the 'transfused' group only 37% of distant metastases were found in the liver, while 71% were found in this site in the 'not transfused' group (chi 2 = 18.46, d.f. = 1, P less than 0.001). By contrast, there was a larger proportion of patients with lung metastases in the transfused group (27% vs 11%) (chi 2 = 5.59, d.f. = 1, P less than 0.05). Therefore, these data do not support the concept of an overall deleterious effect of blood transfusion on patient survival, but suggest that blood given in the perioperative period may change the biology of the metastatic process.

Aged↗
PubMed1989

Factors influencing mortality after curative resection for large bowel cancer in elderly patients.

Mortality rates from the Large Bowel Cancer Project are presented with special reference to patients older than 70 years. The in-hospital mortality rate among those who underwent curative resection for colorectal carcinoma was 7%. Unlike long-term prognosis, which is influenced by pathological features, in-hospital mortality is influenced largely by clinical factors. Age was an adverse factor (78% of deaths occurred among those aged over 70, who formed 46% of the study population), as was obstruction or perforation. 55% of deaths were due to cardiopulmonary complications. Educating patients to seek treatment early, careful preoperative assessment and postoperative monitoring of cardiopulmonary function, and, in selected patients, use of local treatments rather than wide resections may help to reduce mortality in elderly patients.

Age Factors↗
PubMed1989

Primary resection and anastomosis for treatment of acute diverticulitis.

The patterns of presentation and associated treatments of 65 patients with acute perforated diverticulitis of the left colon have been reviewed. Four types of operations were identified: primary resection with anastomosis (group I, N = 29), primary resection with anastomosis and protective colostomy (group II, N = 5), primary resection with Hartmann procedure (group III, N = 26), and delayed resection three-staged procedure (group IV, N = 5). The severity of disease was also classified (stages I to IV). Postoperative mortality rates in the first two groups were lower than that of the Hartmann group (3.4 vs. 15.3 percent). The mean length of initial hospitalization was 16 +/- 1.2 days for group I, 18.2 +/- 4.4 days for group II, 19.4 +/- 2 days for group III, 26.4 +/- 4.4 days for group IV (P less than .05, t-test group IV vs. groups I, II, and III). Complications in the Hartmann group were high with a 23 percent wound infection rate and mortality after closure of colostomy and bowel reconstruction was 3.8 percent. These data demonstrate that primary resection with anastomosis is a satisfactory operation for the majority of patients with perforated diverticulitis (stages I to III), and there appears to be no clinical indication to use the three-staged operation.

Acute Disease↗
PubMed1989

Effect of large-bowel obstruction on colonic blood flow. An experimental study.

The effect of subacute large-bowel obstruction on the mesenteric circulation was studied in a chronic dog model. Colonic obstruction was produced 40 cm distal to the ileocolic sphincter. Five days later, gut blood flow was measured with 15 microns microspheres, together with hemodynamic and metabolic values. Two other groups provided comparative data: unoperated animals to measure baseline values and sham-operative controls. With adequate hydration, hemodynamic and metabolic values remained stable in the experimental group. There was a two-fold increase (P less than 0.05) in blood flow in the dilated colon proximal to the obstruction site, whereas blood flow to the other organs remained unchanged. These results have relevance for the hemodynamic management and use of primary anastomosis in patients with large-bowel obstruction. Furthermore, these data might implicate increased local bowel blood flow as a contributory factor to the poorer long-term prognosis found in patients with large-bowel cancer presenting with intestinal obstruction.

Animals↗