Synchronous tracer injection for O2 uptake and CO2 production measurement.
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Adult↗
Biomedical subjects
R Jones
Publications and source records attributed to R Jones.
Cost-effective diagnostic test sequencing.
Proper diagnostic test selection and logical sequencing can minimize cost without compromising care. This study analyzes the logic for sequencing tests either in series (one after another) or in parallel (simultaneously). A model is created using 2 diagnostic tests for 2 diseases. Tests are assumed to have perfect performance characteristics. Factors involved in cost-effective test sequencing include cost of each test, test performance characteristics, per diem hospital charge, and the clinician's prior probability of the suspected diagnosis based on history, physical examination, and previous laboratory data. At a given point of clinical suspicion, cost-effective sequencing strategy should shift. In general, a cheap test can effectively be used in parallel even at low diagnostic probabilities; an expensive test should, in general, be used in series only when there is a high prior probability of diagnosis. High per diem hospitalization costs--such as for a patient in the intensive care unit--favor in parallel testing. Clinical acumen and suspicion of diagnosis (prior probability) primarily direct cost-effective diagnostic test sequencing. Decision analysis of diagnostic test sequencing represents a technique for making cost-effective decisions for sequencing and, thereby, minimizing costs while achieving optimal patient care.
Cost-Benefit Analysis↗
Functional MRI of the kidney.
Functional MR imaging of the kidney has a great potential of development because the functional parameters, which can be approached noninvasively, are multiple: glomerular filtration, tubular concentration and transit, blood volume and perfusion, diffusion, and oxygenation. Until now, its limitations in clinical applications are due to the difficulties in obtaining reproducible and reliable information in this mobile organ and, sometimes, in understanding the physiologic substrate of the signal changes observed. These approaches require either endogeneous contrast agents, such as water protons (for perfusion and diffusion) or deoxyhemogobin (for oxgenation), or exogeneous contrast agents such as gadolinium chelates (for filtration and perfusion) or iron oxide particles (for perfusion). Clinical validation of these methods and evaluation of their clinical impact are now worthwhile before diffusing them in clinical practice.
Contrast Media↗
Identification and characterization of plasmalogen fatty acids in swine heart.
Reperfusion of ischemic swine myocardium is associated with the loss of sarcolemmal phospholipids resulting in the accumulation of amphiphilic metabolites, lysophosphoglycerides and free fatty acids, especially arachidonic acid, causing electro-physiological dysfunction and cell death. Recently, phospholipids containing a vinyl ether bond at the Sn-1 position, commonly known as plasmalogens, have been identified as major constituents of heart, which contain a large amount of arachidonic acid in the Sn-2 position. Because of the potential importance of plasmalogens, the fatty acid composition of the choline and ethanolamine phosphoglycerides in swine heart was determined. Lipids were extracted from the left ventricular biopsies from swine heart, phosphoglycerides were separated from the neutral lipids by thin layer chromatography, converted into methyl derivatives and analysed by GC. The peaks for fatty acid methyl ester (FAME) and dimethylacetal (DMA) derivatives of choline and ethanolamine phosphoglycerides were confirmed using GC-MS. The results showed high amounts of 18:1 (17 mol%), 18:2 (24 mol %) FAME in choline phosphoglycerides in contrast to the occurrence of a high amount of 20:4 (28 mol%) FAME in ethanolamine phosphoglycerides, suggesting that plasmenylethanolamine, and not plasmenylcholine, may serve as the depot for arachidonic acid in swine heart.
Animals↗
Dose and dose rate effects of beta-particle emitting radioactive stents in a porcine model of restenosis.
BACKGROUND: Radioactive stents have been proposed as a means to prevent in-stent restenosis by inhibiting intimal proliferation with continuous low-dose irradiation. OBJECTIVES: The purpose of this study is to determine the effects of cumulative dose and dose-rate delivery on neointimal formation using 32P and 90Y beta-particle emitting radioactive stents in a porcine coronary model of restenosis. METHODS AND MATERIALS: We compared the late histologic results of 0.25 to 32.0 microCi 90Y (half-life 64 hours) (n = 64 stents) and 0.1 to 57.6 microCi 32P (half-life 14.3 days) (n = 55 stents) Beta-particle emitting radioactive stents with non-radioactive (n = 40) stents in a porcine coronary model of restenosis. A computer-based dosimetry modeling program was used to determine the 28 day cumulative dose and dose-rate delivery for the beta-particle emitting radioactive stents at a distance of 0.1 mm from the stent surface. RESULTS: Continuous low dose-rate (1 to 5 cGy/hr) radiation delivery for > 2 weeks via a 0.1 to 0.5 microCi 32P radioactive stent effectively reduced in-stent neointimal hyperplasia at 90 days. Cumulative doses of > 55 Gy induced severe adventitial fibrosis, microvascular damage and promoted the formation of a matrix-rich neointima. Delayed vascular repair was evident at focal regions within the body of radioactive stents that delivered cumulative doses of > or = 140 Gy at 28 days and cumulative doses of 1,100 Gy at 90 days. CONCLUSIONS: These data may be useful in predicting safe and effective dose and dose rate delivery for beta-particle emitting radioactive stents.
Animals↗
The ecological & economical interrelationship of the environmental systems for the Mostellar Medical Center.
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Alabama↗
Membrane interactions of the putative fusion peptide (MF alpha P) from fertilin-alpha, the mouse sperm protein complex involved in fertilization.
Mammalian fertilization depends upon successful binding and fusion between the membranes of the spermatozoon and the oocyte. These processes are thought to be mediated by a series of protein-protein interactions in which sperm antigens known as fertilins are thought to play a key role. Using a recently developed fluorescence technique, the interactions of the oligopeptide sequence corresponding to the fusogenic domain of mouse fertilin-alpha (MF alpha P) and phospholipid vesicles have been investigated. Following stopped-flow mixing, MF alpha P bound rapidly to phospholipid membranes in a co-operative manner with a Hill coefficient of 2.4 and binding rate constants in excess of 1000 s-1. The co-operative nature of the binding process is suggested to represent evidence of a structural mechanism to prevent egg fertilization by immature spermatozoa. The subsequent membrane insertion was found to take place over a longer time period (with rate constants of up to 6.3 s-1), and was linear with respect to peptide concentration. Comparison of these processes with similar time-resolved circular dichroism measurements revealed that changes in peptide secondary structure were very rapid. Fourier transform infrared spectroscopy measurements confirmed changes in the secondary structure of MF alpha P during interaction with PC phospholipid membranes, indicating that the peptide is mainly present in a beta-structure with a small proportion of alpha-helix. These results are consistent with the hypothesis that fertilin-alpha is the fusogenic species with an important role in fertilization.
ADAM Proteins↗
The virtual mole clinic: preliminary results from the Plymouth skin cancer screening study using telemedicine.
This study evaluated a skin cancer screening service between primary and secondary care in Plymouth using a store and forward telemedicine system. The primary objective was to minimize the time from a patient presenting to a GP with a suspicious lesion to the lesion being assessed and diagnosed by a plastic surgeon. This study retrospectively assessed the practical, technical and operational aspects of incorporating telemedicine into everyday practice and patient satisfaction. Both the GP practice and plastic surgeons were equipped with the appropriate technology for creating, transmitting and accessing an electronic telemedicine record (ETR) via an ISDN 2 line. Patients with suspicious lesions accessed the GP via Mole Check Clinics. The GP captured and transmitted an ETR consisting of digital images and relevant clinical data. In a virtual mole clinic, the plastic surgeon accessed and reviewed the ETR. The expert opinion was entered directly into the ETR and transmitted to the GP within 48 hours. All patients were offered a face-to-face consultation at a real mole clinic within 7 days. Outcomes demonstrated patient and clinician satisfaction and the ability to deliver high quality diagnostic images and resulting expert opinion. This study informed a larger study for future applications of telemedicine.
Humans↗
Evaluation of six commercial amphetamine and methamphetamine immunoassays for cross-reactivity to phenylpropanolamine and ephedrine in urine.
We evaluated six commercially available amphetamine (A) and methamphetamine (MA) immunoassays for their relative cross-reactivities to isomers of phenylpropanolamine (PPA) and ephedrine (E) in urine: Syva EMIT, Abbott fluorescence polarization (FPIA), Roche, and Diagnostic Products Corporation (DPC) radioimmunoassays for A and MA. Two stereoisomers of PPA and four stereoisomers of E were tested using (1) drug-free urine spiked at 1,000 mg/L or 100 mg/L of each compound and (2) 60 clinical urine specimens not containing A or MA but having varying amounts of PPA and/or E. Specimens responding greater than the 1-mg/L A or MA cutoff were defined as positive. All specimens spiked at 100 mg/L were negative by all immunoassays. All specimens spiked at 1,000 mg/L were positive by EMIT and negative by FPIA, Roche A, and DPC A; 1,000 mg/L/-E and d-pseudoephedrine were also positive by Roche MA and DPC MA. Three of the 60 clinical specimens tested positive by EMIT and one specimen tested positive by DPC A and DPC MA.
Amphetamine↗
Methylephedrine concentrations in blood and urine specimens.
Methylephedrine is a sympathomimetic amine that appears in many over-the-counter cough and cold medications throughout the world. The abuse of methylephedrine-containing medications has been reported in Japan. Although methylephedrine is not available in the United States, it was identified in 15 cases received by the Forensic Toxicology Laboratory, Division of Forensic Toxicology, Office of the Armed Forces Medical Examiner, Armed Forces Institute of Pathology over a two-year period; 12 of the 15 cases were collected from patients or decedents located within the confines of the continental United States. Methylephedrine was identified in each case by gas chromatography-nitrogen-phosphorus detection following an alkaline extraction and subsequently confirmed using full scan electron impact mass spectrometry. Quantitation of underivatized methylephedrine was performed using the same technique. Blood methylephedrine concentrations ranged from less than 0.05 to 0.28 mg/L (n = 14), and the mean methylephedrine concentration in urine was 1.6 mg/L (range, 0.15-6.8, n = 11 [excluding case 6]). A literature search revealed little information pertaining to the interpretation of methylephedrine concentrations in the blood. Six of the 15 cases presented here were positive for methylephedrine in the blood. Three of these cases were postmortem cases, and the other three cases were nonfatal aircraft mishaps. There is no evidence in any of these cases that methylephedrine was present at toxic concentrations; therefore, it appears from the cases reviewed in this study that blood methylephedrine concentrations less than 0.3 mg/L are not associated with significant toxicity.
Cause of Death↗
Corneal perforations caused by multiple resistant Pseudomonas organisms: a case report.
Pseudomonas aeruginosa is the most common cause of corneal ulcers in the southern United States as well as being the most virulent corneal pathogen; corneal perforations can follow. The emergence of multiple resistant Pseudomonas organisms in burn units may lead to an increased incidence of this tragic complication.
Adolescent↗
Eating habits and eating disorders during pregnancy.
A general population sample of 100 primigravid women was studied prospectively to describe the changes in eating that occur in pregnancy with particular reference to cravings and aversions and the behavior and attitudes characteristic of clinical eating disorders. Assessment was by standardized interview. Dietary cravings and aversions were found to be common and largely confined to early pregnancy. Eating disorder features decreased in severity early in pregnancy but increased later on. Dietary cravings rarely resulted in episodes of overeating like those seen in patients with eating disorders. In this study of a general population sample, no evidence was found of a relationship between pregnancy outcome and the severity of eating disorder features prior to pregnancy.
Adolescent↗
Establishing a Parent to Parent service.
A Parent to Parent service has been established in Auckland to provide assistance to parents of children with disabilities. Parents who themselves have children with special needs undergo training to prepare them to support other parents. The Auckland scheme is a telephone counselling service which has been set up through cooperation between parents and professionals in the field of special education. Steps in the establishment of the scheme are described, the training course is outlined and various issues regarding the scheme are discussed. After 3 years of operation the Auckland Parent to Parent Service is well established and has developed a model of operation which has been used to set up similar schemes in various other centres around New Zealand. It is intended that this article be of assistance to other groups considering setting up Parent to Parent schemes.
Child↗
Combination antiviral therapy controls severe post-liver transplant recurrence of hepatitis B virus infection.
The authors have successfully used combination ganciclovir and foscarnet chemotherapy to control viral replication following liver transplantation in a patient with severe recurrence of hepatitis B virus (HBV) infection. The disease was characterized by extremely high viraemias, deteriorating liver function, and high levels of intra-hepatic hepatitis B core antigen (HBcAg) and hepatitis B surface antigen (HBsAg). Treatment resulted in a greater than 30-fold reduction in serum HBV DNA and HBsAg levels. Liver function tests returned to normal and the histological progression of the disease was arrested. Hepatic cytoplasmic HBsAg decreased substantially but there was little change in HBcAg, implicating HBsAg rather than HBcAg in the liver injury. Combination antiviral chemotherapy using agents such as ganciclovir and foscarnet may offer a new approach to the management of post-transplant recurrence of HBV.
Adult↗
The effects of dilute epinephrine saline irrigation on the need for tourniquet use in routine arthroscopic knee surgery.
A prospective, randomized, double-blinded study was performed to determine whether dilute epinephrine saline irrigation (1 mg/l) delivered by gravity flow would significantly reduce the need for tourniquet use during routine arthroscopic surgery. One hundred five patients requiring straightforward arthroscopic knee surgery were randomly assigned to either an epinephrine group that received dilute epinephrine irrigation by gravity flow or to a placebo group that received normal saline irrigation by gravity flow. The need for tourniquet use and the tourniquet time, total operative time, and volume of irrigation fluid used were documented and compared between the two groups. A tourniquet was required 50% less often in the epinephrine group than in the placebo group. This difference was found to be statistically significant using the Student's t-test (P < 0.008, alpha < or = 0.05). If a tourniquet was required, the presence of dilute epinephrine in the irrigation fluid did not affect the overall tourniquet time or the ratio of tourniquet time to total operative time. We believe this study proved that dilute epinephrine irrigation is effective in decreasing the need for tourniquet use during routine arthroscopic knee surgery.
Adult↗
Electronic medical consultation: a New Zealand perspective.
Electronic medical consultation is available worldwide through access to the World Wide Web (WWW). This article outlines a research study on the adoption of electronic medical consultation as a means of health delivery. It focuses on the delivery of healthcare specifically for New Zealanders, by New Zealanders. It is acknowledged that the WWW is a global marketplace and that it is therefore difficult to identify New Zealanders' use of such a global market; nevertheless, we attempt to provide a New Zealand perspective on electronic medical consultation.
Commerce↗
Keep ahead of the game if you want to recommend quality Websites to patients. Follow the guide.
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Computer User Training↗