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Biomedical subjects

P Morgan

Publications and source records attributed to P Morgan.

At least 127 records · Page 7Linked to original sources
PubMed1978

A controlled trial of the theory of acupuncture in musculoskeletal pain.

We carried out a randomized trail compraing acupuncture done is theoretically correct [appropriate] and incorrect [inappropirate] locations for chronic musculoskeletal pains in various sites. Throughout the trial, neither the patient, nor the assessor, nor the acupuncturist, knew if the site of the acupuncture was appropriate to the patient's symptoms according to acupuncture theory. Although 60% had reduced pain after three treatments, there was no significant difference between the treatments. Our findings, while not disproving the value of acupuncture, do not support the theory that certain specific points must be needled to relieve specific areas of pain.

Acupuncture Therapy↗
PubMed1976

Growth of the vomero-premaxillary suture in children with bilateral cleft lip and palate. A histological and roentgencephalometric study.

The significance of the vomero-premaxillary suture (VPS) in mid-facial development in patients with complete bilateral cleft lip and palate (C-BCLP) was evaluated. Histological analysis of the VPS in eight specimens, ranging in age from full term to 22 months, revealed evidence of growth at both sutural borders. Various theories to explain the consistent presence of secondary cartilage, localized mainly to the posterior end of the suture, were assessed. It was considered most likely that the formation of cartilage was promoted by mechanical stresses, set up during a period of rapid growth. Roentgencephalometric data from seven C-BCLP patients (age range: 2-7 months) demonstrated the existence of a true, rather than a relative, premaxillary protrusion. Five patients had metallic implants inserted on either side of the VPS at the time of initial surgery and were followed up roentgencephalometrically to ages ranging from 5 to 36 months. Although continuous growth was recorded in the VPS, there was a post-surgical decrease in the premaxillary protrusion. On the basis of both the histology and roentgencephalometry it was concluded that traumatic surgery involving the VPS would be likely to contribute to the impaired mid-facial growth sometimes seen in operated C-BCLP patients.

Cephalometry↗
PubMed1975

Selection acting directly on an enzyme polymorphism.

A biochemical approach is utilised in the study of the maintenance of variation at the Adh locus in Drosophila melanogaster. There is a direct correlation between biochemical findings and the results of competition experiments. The relevance of these findings to the study of other enzyme polymorphisms is discussed.

Alcohol Oxidoreductases↗
PubMed1975

Enzyme histochemical studies on the formation of hyalin bodies in the epithelium of odontogenic cysts.

Frozen sections of eight odontogenic cysts, including one keratocyst, were incubated to show the following enzyme activities: NADH2 diaphorase, NADPH2 diaphorase, glucose-6-phosphate dehydrogenase, acid phosphatase and leucine aminopeptidase. The disbribution of lipid was shown by the oil red 0 method. The activities of all three oxidative enzymes were strongest in epithelial cells bordering hyalin bodies and in basal cells in the epithelial lining. Hydrolytic enzyme activity was absent from all but the most superficial epithelial cells but was present in macrophages and, in lesser amounts, in granular material in the same sections. The granular material frequently contained lipid. The lack of hydrolytic enzyme activity in bordering epithelial cells is inconsistent with the theory that hyalin bodies form from degenerating blood vessels. High aerobic oxidative enzyme activity in the same cells also conflicts with the concept that the bodies are a keratinous product. The findings lend support to the theory that hyalin bodies are an epithelial secretion.

Acid Phosphatase↗
PubMed1975

The role of driver demerit points and age in the prediction of motor vehicle collisions.

The records of drivers, selected from the file of licensed drivers in Ontario, were reviewed to study the relationship between demerit points, other driver characteristics, and the frequency or risk of future collisions and traffic convictions. A stratified sample of 500-600 drivers from each of five levels of demerit points was selected. Low-point drivers differed significantly from high-point drivers in age, sex, and class of licence; estimates of risk of collision or conviction in each demerit point group had to take account of these differences. Discriminant analysis was used to identify drivers likely to be involved in collisions or to be given traffic convictions, and to identify accidents involving injury or fatality. Of the traits considered (demerit points, age, sex, class of licence, history of previous accidents), demerit points represented the only variable of importance in predicting future collision involvement. Since it is the only one of these variables which can be altered by driver behaviour it offers an opportunity to prevent accidents.

Accidents, Traffic↗
PubMedDate not supplied

Role of transport proteins in drug absorption, distribution and excretion.

1. The molecular and functional characterization of transport proteins is emerging rapidly and significant numbers of drugs have been shown to be substrates or inhibitors. The purpose of this review is to highlight the in vivo preclinical and clinical evidence that supports a role for transport proteins in attenuating the absorption, distribution and excretion (ADE) of drugs. 2. For absorption, a clear role has emerged for P-glycoprotein in limiting permeability across the gastrointestinal tract. As a result, a wide variety of drugs suffer from incomplete, variable and non-linear absorption. Similarly, at the blood-brain barrier a range of drugs has limited brain penetration due to P-glycoprotein-mediated efflux, which can limit therapeutic effectiveness of CNS agents. In the liver, transport proteins are present on the sinusoidal membrane that can be the rate-limiting step in hepatic clearance for some drugs. Mechanistic studies clearly suggest a key role and broad substrate specificity for the OATP family of sinusoidal transporters. Mainly ATP-dependent transport proteins such as P-glycoprotein and MRP2 govern active biliary excretion. 3. Drug-drug interactions have been demonstrated involving inhibition or induction of transport proteins. Clinically significant interactions in the gastrointestinal tract and kidney have been observed with inhibitors such as ketoconazole, erythromycin, verapamil, quinidine, probenecid and cimetidine. Clinically significant inhibition at the blood-brain barrier is more difficult to demonstrate, relying on pharmacodynamic and toxicodynamic changes, but an example is quinidine increasing loperamide-induced central effects in humans. 4. This review highlights the emerging role of transport proteins in ADE of drugs and suggests these need to be considered, in drug discovery and development, with respect to variability in drug disposition and response.

Absorption↗
PubMedDate not supplied

Medical accelerator safety considerations: report of AAPM Radiation Therapy Committee Task Group No. 35.

Ensuring safe operation for a medical accelerator is a difficult task. Users must assume more responsibility in using contemporary equipment. Additionally, users must work closely with manufacturers in promoting the safe and effective use of such complex equipment. Complex treatment techniques and treatment modality changeover procedures merit detailed, unambiguous written procedural instruction at the control console. A thorough "hands on" training period after receiving instructions, and before assuming treatment responsibilities, is essential for all technologists. Unambiguous written instructions must also be provided to guide technologists in safe response when equipment malfunctions or exhibits unexpected behavior or after any component has been changed or readjusted. Technologists should be given a written list of the appropriate individuals to consult when unexpected machine behavior occurs. They should be assisted in identifying aberrant behavior of equipment. Many centers already provide this instruction, but others may not. Practiced response and discussion with technologists should be a part of an ongoing quality assurance program. An important aspect of a safety program is the need for continuous vigilance. Table III gives a summary of a comprehensive safety program for medical accelerators. Table IV gives a list of summary recommendations as an example of how one might mitigate the consequences of an equipment failure and improve procedures and operator response in the context of the environment described. Most of these recommendations can be implemented almost immediately at any individual treatment center.

Biophysical Phenomena↗