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Biomedical subjects

J E Armstrong

Publications and source records attributed to J E Armstrong.

15 recordsLinked to original sources
PubMed1992

Anatomic placement of fixation devices in genioplasty.

The form of the anterior mandible in 45 patients was assessed before, immediately after, and 1 year after genioplasty. A specific, consistent pattern of bone apposition and resorption was observed after advancement genioplasty. A consistent but inverse apposition-resorption pattern was observed after reduction genioplasty. In view of the observed pattern of bony change, it is recommended that fixation devices for genioplasty be placed in areas of future bone deposition.

Adolescent↗
PubMed1990

[The importance of avoiding the use of rigid fixation in functional genioplasty].

This article presents a brief review of several principles which Delaire has shown to be important in both craniofacial growth and cranio-maxillofacial balance. In light of these events, we propose that the maxillofacial surgeon either avoids, if possible, the use of rigid fixation in functional genioplasty or that he removes the screws and plate at a later date. The specific patterns of bone apposition and resorption observed following functional genioplasty form the basis for this recommendation.

Chin↗
PubMed1990

Vasodepressor syncope.

Vasodepressor syncope is the fulminant expression of the behavioral disorder "Blood-Injury Phobia". Vasodepressor syncope or the "common faint" is characterized by a diphasic autonomic hyperactivity that begins with anxiety and leads to a transient loss of consciousness. Recognition of the behavioral etiology of this disorder suggests the possibility of prevention through psychotherapy. Understanding the pathophysiology of the diphasic autonomic hyperactivity allows for rational management of the "common faint".

Dental Care↗
PubMed1989

Quality assurance's role in reducing liability costs.

This article provides information on containing liability protection costs. The authors, experienced corporate and institutional liability protection specialists who provide risk management services to the medical and business community, describe the causes of the high cost of liability insurance and cost-saving alternatives to traditional insurance. Quality assurance's role in working with risk management to prevent losses and reduce costs in a self-insured program is covered. Insurance costs rise and fall in inevitable cycles, but the medical community can protect itself from these cycles. Quality assurance and risk management can work together to reduce costs and prevent losses. The principal conclusion is that through policies, procedures, and information exchange, quality assurance can expand its risk management role to help maintain high quality health care and financial stability. Within a self-insured liability program, direct savings to the institution will result.

Communication↗
PubMed1988

Le Fort I down-fracture of the maxilla: application to benign antral neoplasm.

Benign neoplasms of the maxillo-facial region require different treatment than do malignant lesions. Conservation of adjacent tissues is vital in order to optimize postoperative function and esthetics. The Le Fort I down-fracture technique is a historically proven approach for resecting benign neoplasms involving the nasal and para-nasal cavities. The Le Fort I, as practised today, is transoral and placed superior to the dento-alveolar processes of the maxilla. Surgical access, therefore, need not result in a skin scar nor loss of dental structures. Postoperative recovery to full function is rapid. The elegance and versatility of the Le Fort I down-fracture technique is discussed with reference to the report of a large, intra-antral benign odontogenic neoplasm.

Adolescent↗
PubMed1978

Inhibition of light-induced pH increase and O2 evolution of marine microalgae by water-soluble components of crude and refined oils.

Light-induced alkalinization of the extracellular medium was found to be a common feature of the primary photosynthetic process of several marine microalgae. The light-induce PH increase of suspensions of whole cells was immediately and severely inhibited by a single dose of water-soluble components from crude and fuel oils. Differential effects on the rates of microalgal photosynthetic O2 evolution and cell suspension pH increase suggest different toxicity mechanisms of the water-soluble components of no. 2 fuel oil as compared with Southern Louisiana and Jay Crude oils. These short-term studies on the nature of sublethal petroleum toxicity to microalgae indicate that the primary effect may be through direct action on the energy-yielding electron transport systems.

Eukaryota↗
PubMed1975

Evidence for the occurrence of specific iron (III)-binding compounds in near-shore marine ecosystems.

Aqueous extracts of samples from representtive types of near-shore marine ecosystems were examined for growth-promoting activity for the siderochrome auxotroph, Arthrobacter JG-9. Blue-green algal mat and sea grass samples gave strongly positive responses. Relative to Desferal (Ciba Pharmaceutical Co., Summit, N.J.), concentrations up to 110 ng/g (wet weight) of sample were found. In contrast, extracts of anaerobic muds or macroalgae gave no detectable activity. The hydroxamate type of iron chelator may be important in providing a form of iron in sea water readily utilized by the microalgae and marine higher plants.

Arthrobacter↗
PubMed1973

Osmotic regulation of alpha-amylase synthesis and polyribosome formation in aleurone cells of barley.

Water stress inhibits the gibberellic acid (GA(3))-induced synthesis of alpha-amylase in aleurone layers of barley (Hordeum vulgare L.). Electron microscope evidence indicates that the effect of water stress induced by 0.6 M solutions of polyethylene glycol (PEG) is to reduce the binding of ribosomes to the endoplasmic reticulum. This was confirmed by sucrose density gradient centrifugation of polyribosome preparations from stressed cells. The reduction in polyribosome formation does not result from reduced ribosome activity as measured by [(3)H]peptidylpuromycin formation. Thus, calculation of percent active ribosomes shows that osmoticum has little effect on the ability of ribosomes to incorporate puromycin into nascent protein. Water stress does not cause a marked decrease in the total RNA level of aleurone cells. Estimates of total RNA in postmitochondrial supernatant fractions from stressed cells show only a reduction of 8-9% relative to the control. Membrane synthesis measured by [(14)C]choline incorporation is depressed by 15% in cells stressed with 0.6 M PEG for 2.5 hours.

Amylases↗
PubMed1973

The regional distribution of emotional sweating in man.

1. Emotional sweating was induced in normal subjects by mental arithmetic at environmental temperatures of 29 and 26 degrees C and estimated from continuous records of body weight loss.2. The sweat output from four independent regions of the body - (a) the head and neck, (b) the arms and legs, (c) the trunk, and (d) the hands and feet - was studied separately, the remainder of the body being covered in each case by plastic bags. The evaporative water loss from each skin region increased markedly during mental arithmetic.3. The sweat contribution from each region was a substantial fraction of the total body sweat response and appeared to be roughly proportional to the calculated number of sweat glands in each region.4. There is no evidence from these experiments to indicate that the sweat glands of the skin of the hands and feet behave differently to those of the skin of the rest of the body in response to emotional stress.

Adult↗