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Biomedical subjects

M L Phillips

Publications and source records attributed to M L Phillips.

123 records · Page 7Linked to original sources
PubMed1973

Effects of 2-Butylmalonate, 2-Phenylsuccinate, Benzylmalonate, and p-Iodobenzylmalonate on the Oxidation of Substrates by Mung Bean Mitochondria.

The effect of inhibitors of carboxylic acid anion transport on the oxidation of substrates by mung bean (Phaseolus aureus) mitochondria was investigated. The oxidation of malate in the presence of either glutamate or cysteine sulfinate was inhibited by 2-butylmalonate, 2-phenylsuccinate, benzylmalonate, and p-iodobenzylmalonate in both intact and broken mitochondria. The oxidation of succinate, on the other hand, was inhibited in intact but not in broken mitochondria. The oxidation of reduced nicotinamide adenine dinucleotide was inhibited only by p-iodobenzylmalonate. This inhibition occurred only in coupled mitochondria and could be reversed by the addition of adenosine diphosphate.These results suggest that the compounds studied inhibit the entry of succinate and probably also of malate into mung bean mitochondria. All four compounds inhibit the enzyme (s) which oxidize malate while p-iodobenzylmalonate also interferes with oxidative phosphorylation.

Journal Article↗
PubMed1973

Anion transporters in plant mitochondria.

The swelling of potato (Solanum tuberosum L.) mitochondria in isosmotic ammonium salts of phosphate, chloride, malate, succinate, and citrate was investigated by measuring light scattering. Potato mitochondria swell spontaneously in ammonium phosphate, and this swelling can be inhibited in N-ethylmaleimide. They swell in ammonium malate or succinate only after the addition of inorganic phosphate and in ammonium citrate only after the addition of both phosphate and a dicarboxylic acid. Pentylmalonate inhibits swelling in ammonium citrate solutions by competing for dicarboxylate entry. The results indicate that potato mitochondria possess a phosphate-hydroxyl carrier, a dicarboxylate carrier, and a tricarboxylate carrier.

Journal Article↗
PubMedDate not supplied

Use of global positioning system technology to track subject's location during environmental exposure sampling.

Global positioning system (GPS) data recorders were worn by subjects in the Oklahoma Urban Air Toxics Study (OUATS) for automatic logging of their location as they went about their normal daily activities. The location information obtained by the GPS units had an uncertainty of about 10-20 m, which was sufficiently precise to track subjects' movements on trips outside the immediate vicinity of their homes. Due to instrument problems, primarily related to reduced battery life, the units operated for only about 30% of the total monitoring time attempted in 25 trials. The GPS data were compared to time-activity diaries kept by the subjects. In almost all cases, the GPS data confirmed all travel events reported in the subjects' diaries. Additionally, in five out of five trials in which the logging period covered most or all of the subjects' daytime activities, at least one travel event that was not recorded in the diary was detected by GPS. Notwithstanding the limitations of present technology, GPS was found to be a promising means for tracking of research subjects in community-based exposure assessment studies.

Adult↗
PubMedDate not supplied

Matrix-enabled gene transfer for cutaneous wound repair.

Several growth factor proteins have been evaluated as therapeutic agents for the treatment of chronic dermal wounds. Unfortunately, most have failed to produce significant improvements in wound healing, in part due to ineffective delivery and poor retention in the wound defect. It has been proposed that gene therapy might overcome the limitations of protein therapy via ongoing transcription and translation, thus prolonging the availability of the therapeutic protein. Reasoning that it would be of further benefit to ensure retention of the DNA vector as well as the therapeutic protein within the wound defect, we have evaluated matrix-enabled gene transfer for cutaneous wound repair (Gene Activated Matrix). Formulations consisting of bovine type I collagen mixed with adenoviral or plasmid gene vectors have been evaluated in 3 in vivo models. The therapeutic transgenes employed encode human platelet-derived growth factor-A or -B, proteins key to each phase of normal wound repair. Increased granulation tissue formation, vascularization, and reepithelialization have been shown compared to controls treated with collagen alone or collagen containing a reporter gene vector. Further enhancements of the tissue repair response have been achieved by combining matrix-enabled gene transfer with molecular targeting, in which the DNA vector is conjugated to a growth factor ligand (basic fibroblast growth factor). These promising results support the clinical evaluation of gene activated matrices for the treatment of chronic dermal wounds.

Animals↗
PubMedDate not supplied

Visual imagery and depersonalisation.

Twenty-eight people diagnosed with depersonalisation disorder (DD) were assessed using self-report measures of imagery ability in relation to a range of symptoms and in comparison with age- and sex-matched controls. It was found that symptoms of depersonalisation as well as other dissociative symptoms and depressed mood correlated with impaired ability to generate visual images. This was particularly evident with images pertaining to the self and other people as opposed to objects. A subgroup of 10 patients was tested on a neuropsychological battery of visual perception tests and found to be unimpaired compared with normal controls and patients with obsessive compulsive disorder, despite subjective impairments in imagery and high symptom scores. The findings add further weight to the distinctions made between imagery and perceptual processes.

Adult↗
PubMedDate not supplied

Astrocytomas: the clinical picture.

An astrocytoma is one of the most common brain tumors. Approximately 16,500 people will be diagnosed with brain cancer this year in the United States; of these, an estimated 13,000 will die. Astrocytomas originate from astrocytes in the central nervous system, and the maximum average life expectancy following an astrocytoma diagnosis is 18 months. Intracranial tumors often are devastating because of their growth and spread to vital centers, where they alter neurologic functions that make patients "people." Surgery, radiation, biotherapy, and chemotherapy are among the most common regimens used to treat these life-threatening intracranial tumors. Nurses caring for these patients play a vital role in providing pertinent interventions, emotional support, and end-of-life care.

Antineoplastic Agents↗
PubMedDate not supplied

Diffusion of an innovation: adoption of MRI.

"Diffusion of Innovation" is a marketing theory that predicts the pattern of adoption of new products, with specific characteristics of the product determining the rate of adoption. This article attempts to determine whether MRI fits the predicted pattern. A computer Medline search to assess the number of articles printed on MRI shows that MRI is being adopted more slowly than CT, but like CT, MRI is following the pattern predicted by the Diffusion Theory.

Communication↗
PubMedDate not supplied

Diffusion of an innovation: adoption of CT scanners.

"Diffusion of Innovation" is a marketing theory that predicts the pattern of adoption of new products. The characteristics of an innovation and the "diffusion stages" of a new product as it moves toward widespread adoption are described. Then, the predictions of diffusion theory are compared to the pattern of adoption of CT.

Communication↗