Search PubMed⌕ Search

Biomedical subjects

P Crane

Publications and source records attributed to P Crane.

10 recordsLinked to original sources
PubMed2001

Evidence- and consensus-based practice guidelines for the diagnosis of irritable bowel syndrome.

BACKGROUND: Irritable bowel syndrome (IBS) presents a significant diagnostic and management challenge for primary care practitioners. Improving the accuracy and timeliness of diagnosis may result in improved quality and efficiency of care. OBJECTIVE: To systematically appraise the existing diagnostic criteria and combine the evidence with expert opinion to derive evidence- and consensus-based guidelines for a diagnostic approach to patients with suspected IBS. METHODS: We performed a systematic literature review (January 1966-April 2000) of computerized bibliographic databases. Articles meeting explicit inclusion criteria for diagnostic studies in IBS were subjected to critical appraisal, which formed the basis of guideline statements presented to an expert panel. To develop a diagnostic algorithm, an expert panel of specialists and primary care physicians was used to fill in gaps in the literature. Consensus was developed using a modified Delphi technique. RESULTS: The systematic literature review identified only 13 published studies regarding the effectiveness of competing diagnostic approaches for IBS, the accuracy of diagnostic tests, and the internal validity of current diagnostic symptom criteria. Few studies met accepted methodological criteria. While symptom criteria have been validated, the utility of endoscopic and other diagnostic interventions remains unknown. An analysis of the literature, combined with consensus from experienced clinicians, resulted in the development of a diagnostic algorithm relevant to primary care that emphasizes a symptom-based diagnostic approach, refers patients with alarm symptoms to subspecialists, and reserves radiographic, endoscopic, and other tests for referral cases. The resulting algorithm highlights the reliance on symptom criteria and comprises a primary module, 3 submodules based on the predominant symptom pattern (constipation, diarrhea, and pain) and severity level, and a subspecialist referral module. CONCLUSIONS: The dearth of available evidence highlights the need for more rigorous scientific validation to identify the most accurate methods of diagnosing IBS. Until such time, the diagnostic algorithm presented herein could inform decision making for a range of providers caring for primary care patients with abdominal discomfort or pain and altered bowel function suggestive of IBS.

Algorithms↗
PubMed2000

Newly synthesized lithium in the interstellar medium

Astronomical observations of elemental and isotopic abundances provide the means to determine the source of elements and to reveal their evolutionary pathways since the formation of the Galaxy some 15 billion years ago. The abundance of lithium is particularly interesting because, although some of it is thought to be primordial, most results from spallation reactions (in which Galactic cosmic rays break apart larger nuclei in the interstellar medium). Spallation reactions are crucial for the production of other light elements, such as beryllium and boron, so observations of lithium isotopic abundances can be used to test model predictions for light-element synthesis in general. Here we report observations of 7Li and 6Li abundances in several interstellar clouds lying in the direction of the star o Persei. We find the abundance ratio 7Li/6Li to be about 2, which is significantly lower than the average Solar System value of 12.3 (refs 6, 7). An abundance ratio of 2 is clear evidence that the observed lithium must have resulted entirely from spallation, confirming a basic tenet of light-element synthesis. The total lithium abundance, however, is not enhanced as expected.

Journal Article↗
PubMed1993

Donor cell infiltration of recipient tissue as an indicator of small bowel allograft rejection in the rat.

This study assessed whether screening of host tissues for graft cells could be used as an effective monitor of rejection following small bowel transplantation. Allogeneic rat small bowel transplantation was performed with or without cyclosporin (CyA) immunosuppression and cellular infiltration of host tissues assessed by immunohistological staining. Without immunosuppression, grafts were completely rejected within 1 week. CyA treatment for 7 days preserved the graft for 28 days although there was histological evidence of mild rejection in some of the animals studied. Continuous CyA treatment preserved the graft for up to 56 days. The peripheral lymph nodes and spleens of untreated animals were transiently infiltrated by low numbers of donor cells that disappeared by day 6. There was a marked donor cell infiltration of the lymph nodes and spleens of 7-day. CyA-treated animals that was maintained during the administration of immunosuppressive therapy but that declined thereafter. Continuous CyA treatment sustained donor cell infiltration up to day 56. These findings suggest the presence of donor cells in recipient lymph nodes and spleen to be indicative of effective control of rejection and their disappearance to be predictive of developing rejection responses. Examination of recipient peripheral tissues for donor cells may provide an improved technique for monitoring clinical small bowel transplantation.

Animals↗
PubMed1993

Effect of mitochondrial viability and metabolism on technetium-99m-sestamibi myocardial retention.

This study investigated the mechanism of myocardial retention of technetium-99m-sestamibi. 99mTc-sestamibi was injected intravenously into guinea pigs, and the myocardium was homogenized and fractionated by differential centrifugation. More than 90% of myocardial 99mTc-sestamibi was localized within the mitochondrial fraction. Calcium was found to release 99mTc-sestamibi from the mitochondrial fraction, with an IC50 of 2.54 +/- 0.98 mM. This effect was potentiated by NaCl, and inhibited by the mitochondrial calcium channel blocker ruthenium red. In vitro uptake of 99mTc-sestamibi was found to increase from 10.5% +/- 3.0% to 61.2% +/- 0.2% with the addition of 10 mM succinate, indicating that respiration is involved. Since irreversible ischemia results in cellular and mitochondrial calcium "overload" and loss of mitochondrial metabolic function, 99mTc-sestamibi should not be retained in necrotic or irreversibly ischemic myocardium, and could potentially act as a sensitive indicator of myocardial cell viability.

Animals↗
PubMed1992

Ex vivo perfusion of intestinal allografts with anti-T cell monoclonal antibody/ricin A chain conjugates for the suppression of graft-versus-host disease.

The removal of T lymphocytes from intestinal allografts prior to transplantation would prevent graft-versus-host disease and might also weaken the unusually severe rejection response mounted by graft recipients. Ex vivo perfusion by monoclonal antibody-toxin conjugates represents a potentially ideal approach to achieve this goal. Monoclonal antibody-toxin conjugates were prepared by coupling the mouse anti rat CD5 antibody MRC OX19 to the A chain of ricin. The resultant conjugate contained 1 or 2 ricin A chain molecules per molecule of immunoglobulin and had high selective toxicity for rat T lymphocytes. Following ex vivo perfusion of the small intestine, the mesenteric lymph nodes and Peyer's patches were removed and the level of penetration of the MRC OX19 antibody was assayed by immunohistological techniques. In lymph nodes, there was ready access of the antibody to the medulla, and to a lesser extent to the B cell areas of the cortex. However, only the T cells in the peripheral regions of the paracortex were stained, suggesting that the paracortex was resistant to penetration by blood-borne antibody, and was being stained only by diffusion from the lymph node medulla. Some penetration of the antibody also occurred in the immediate vicinity of the postcapillary venules. In the Peyer's patches, staining was seen in the germinal centers, but not at all in the T cell areas. The addition of agents such as histamine to the perfusate to increase vascular permeability did not alter this picture. These studies suggest the presence of a potentially interesting resistance to penetration of the paracortex of the lymph node by blood-borne substances. Nevertheless, sufficient penetration occurred to influence favorably the course of GVD disease following ex vivo perfusion prior to transplantation of the donor intestine with the MRC OX19-ricin A chain conjugate.

Animals↗
PubMed1981

A silicone delivery system for producing binge and continuous ethanol intoxication in rats.

A silicone delivery system for administering large quantities of ethanol (ETOH) to rats is described. When implanted subcutaneously and filled with 95% ETOH (v/v), lethal quantities can be administered within 5 days. Two different models are described: a rapid release thin-walled silicone pillow which can be filled with 95% ETOH for 3 hours daily so as to induce binge-like, transient high blood ETOH levels and motor impairment, and a thicker pillow which can be filled daily with 84% ETOH (v/v) so as to produce continuous ETOH administration. When different groups of rats administered similar amounts of ETOH using these two different regimens were compared, it was found that caloric intake (food + ETOH) and body weight were reduced in the Binge group whereas the Continuous group gained weight although their total caloric intake was similar to Controls. This delivery system can deliver appreciable amounts of ETOH to rats in the absence of gustatory stimulation and in two intake patterns which have been reported to occur in alcoholics.

Alcoholic Intoxication↗
PubMedDate not supplied

Spinal pain rehabilitation: inpatient and outpatient treatment results and development of predictors for outcome.

Multidisciplinary treatment outcomes with a 1-year follow-up is reported for 100 chronic low-back pain patients participating in inpatient rehabilitation and 100 patients participating in outpatient rehabilitation. Treatment for both groups of patients was based on principles of operant conditioning and consisted of increasing structured exercise activities and educational classes for instruction in techniques of pain management. Results are presented in terms of patient reports of decreased pain, increased activity, decreased medication, need for further treatment, and return to work. A method for predicting return to work was developed by way of a computerized discriminate analysis with the formulas presented for consideration by those interested in similar patient groups.

Adult↗