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Biomedical subjects

C L Henderson

Publications and source records attributed to C L Henderson.

9 recordsLinked to original sources
PubMed1997

A North American survey of intravenous regional anesthesia.

UNLABELLED: One thousand questionnaires concerning the techniques and complications of intravenous regional anesthesia (IVRA) were sent to 900 American and 100 Canadian anesthesiologists. Of the 321 respondents, 86% perform IVRA regularly. A wide variation in device-related and clinical aspects was found, ranging from acceptable to falling outside published guidelines. Anesthesiologists perform a median of four upper-limb IVR procedures per month, most often using 50 mL of lidocaine 0.5% at tourniquet pressures of 250 mm Hg or 100 mm Hg greater than the systolic blood pressure. Forearm, thigh, and calf IVRA are occasionally used. Complications, reported infrequently in the literature, were reported by respondents, including mistaken deflation of the cuff; dysphoria, dizziness, or facial tingling; seizures; cardiac arrests; and deaths. Although there was no correlation between complications and deviation from traditional practice, we recommend that IVRA be performed following recognized protocols by anesthesiologists who are familiar with the technique and trained to treat its potential complications. We recommend a protocol for IVRA. IMPLICATIONS: Intravenous regional anesthesia is a widely used anesthetic technique. A survey of 321 American and Canadian anesthesiologists indicates a wide variation in technique. Despite no correlation between complications and technique, the authors recommend that recognized protocols be used for this technique.

Adult↗
PubMed1997

The impact of consumer health information provided by libraries: the Delaware experience.

In the past two decades, consumer health libraries have proliferated in response to the changing health care environment and consumer demand. While this growth of consumer health resources and services has been extensively described in the literature, there is little documentation about the impact and value of providing consumer health information. This paper explores the issues of impact and value as examined in a retrospective study of consumers who received health information from the Delaware Academy of Medicine's Consumer Health Library during 1995. In this study, 270 adults were mailed a questionnaire that focused on whether the information influenced decisions, actions, anxiety levels, and patient-provider communication. The questionnaire also addressed the value of such library service in terms of likelihood of repeat use, recommendation to others, and willingness to pay. The results, based on a return rate of 86.7%, identified effects of library-supplied consumer health information that extend beyond the anticipated acquisition of knowledge to specific actions and effects on anxiety. The value of consumer health library information service was shown by the extremely high percentage of probable repeat use and recommendation to others, the willingness of 83.8% of the respondents to pay for such service, and the copious comments volunteered by the respondents.

Adult↗
PubMed1996

Oxygen flow through nasal cannulae.

PURPOSE: Since many operating theatres do not have distinct oxygen flowmeters, flow rates of oxygen were measured via nasal prongs at several settings and attachments to three anaesthetic machines. METHODS: Oxygen-flow rates were measured using a Timeter RT-200 Calibration Analyzer at three, five and eight L.min-1 via nasal prongs attached to a distinct flowmeter, the common gas outlet (CGO) and the Y-piece of a circle system with the adjustable pressure release (APL) valve closed, open and partially open at circuit pressures of 10 and 20 cm H2O. RESULTS: The most accurate delivery of oxygen from a distinct flowmeter and the CGO (mean difference 0.2 +/- 0.2 and 0.4 +/- 0.4 respectively). Differences between the flowmeter and CGO were not significant (P = 0.1). Accuracy of flows via the Y-piece were worse than via the flowmeter and CGO (P < 0.0001). Flows via the Y-piece were less than those dialed, especially at high rates. With a partially open APL valve, flow depended upon pressure in the anaesthetic circuit, not upon the flow set. With the APL valve completely open, no flow occurred. CONCLUSIONS: To deliver supplemental oxygen in the operating theatre when there are no distinct flowmeters, nasal prongs should be attached to the CGO of the anaesthetic machine or a flowmeter on a portable E-tank oxygen cylinder. Connecting nasal prongs to the Y-piece of a circle system should be avoided since oxygen delivery is less than dialed, especially when the APL valve is open.

Anesthesia, Closed-Circuit↗
PubMed1995

Tracheal rupture following blunt chest trauma presenting as endotracheal tube obstruction.

In this report, we describe a patient in whom a tracheal tear followed blunt thoracic trauma. The diagnosis was made late resulting in problems with ventilation, endotracheal tube obstruction and cardiac arrest. Difficulties with early recognition of tracheobronchial injuries may be caused by non-specific findings as well as the lack of exposure of physicians to patients with these injuries. The signs and symptoms of tracheobronchial injuries are described, as well as their differential diagnoses. A review of airway management has been made as it requires combined anaesthetic and surgical expertise. Injuries of the trachea may have severe, life-threatening consequences and early diagnosis and management reduce morbidity and mortality.

Airway Obstruction↗
PubMed1991

Histopathology of multiple sclerosis lesions detected by magnetic resonance imaging in unfixed postmortem central nervous system tissue.

Postmortem unfixed whole brains from 17 multiple sclerosis and 6 control cases were examined by magnetic resonance imaging (MRI) using a T2-weighted spin echo sequence and histology to determine the relationship between areas of abnormal MRI signal and underlying pathological change. In group 1, small MRI lesions and correspondingly small plaques, most of which were chronic, were detected histologically in 5 brains. In 4 brains there were more extensive areas of both abnormal signal and histological plaques which were more often active (group 2). However, in a further 5 brains extensive MRI abnormalities were observed when only small periventricular plaques were present histologically (group 3). Lesions in the hindbrain and cerebral grey matter were infrequently observed by MRI. The extensive MRI abnormalities seen in areas in which only small histological plaques were found may be the result of vascular permeability changes in the normal-appearing white matter surrounding plaques.

Autopsy↗
PubMed1990

Correlation of Pityosporum ovale density with clinical severity of seborrheic dermatitis as assessed by a simplified technique.

One hundred patients with facial seborrheic dermatitis and 42 control subjects were studied. The number of periodic acid-Schiff-positive Pityosporum ovale yeast cells in skin scrapings per high-power field were counted and designated 1 + to 4 +. Our data indicate a correlation between the density of P. ovale and the clinical severity of seborrheic dermatitis, both before and after therapy with a precipitated sulfur/salicyclic acid shampoo. The data support the concept that yeast contributes to the pathogenesis of seborrheic dermatitis.

Administration, Cutaneous↗
PubMed1990

A mutant of Mycoplasma mycoides subsp. mycoides lacking the H2O2- producing enzyme L-alpha-glycerophosphate oxidase.

Cells of Mycoplasma mycoides subsp. mycoides grown without stirring or aeration in batch culture, and resuspended in a salts solution, oxidised a range of carbohydrates including glycerol. The rate of glycerol oxidation was not reduced when cells were passaged more than 20 times in batch culture. However, in cells grown in stirred and aerated chemostat culture for 100 generations the ability to oxidise glycerol, but not other carbohydrates, was lost or greatly reduced. A mutant strain isolated from chemostat even after several passages in batch culture. The growth rate and growth-yield of the mutant strain in batch culture were similar to those of the parent strain. The mutant possessed activity for glycerol kinase but had lost that for the hydrogen peroxide-producing enzyme, L-alpha-glycerophosphate oxidase. The selection pressure in favour of the mutant strain in chemostat culture may be a decreased production of hydrogen peroxide.

Culture Media↗
PubMed1986

Identification of the parasite transferrin receptor of Plasmodium falciparum-infected erythrocytes and its acylation via 1,2-diacyl-sn-glycerol.

The transferrin receptor of schizont-infected erythrocytes of Plasmodium falciparum (Gambian clone FCR-3/A2) is a parasite-encoded protein of Mr 102,000, which is present in purified erythrocyte membranes. Polyclonal antiserum to the purified Mr 102,000 protein was raised in rabbits. At physiological pH, immunoaffinity-purified protein bound human ferrotransferrin but not apotransferrin. Conversely, antibody to human transferrin was used to purify the ferrotransferrin-receptor complex from infected cells. The isolated receptor was specifically recognized by the polyclonal rabbit antiserum raised against the Mr 102,000 protein. Preliminary analysis indicated that, unlike the human receptor, the plasmodial transferrin receptor is not a disulfide linked dimer but a single polypeptide acylated via 1,2-diacyl-sn-glycerol.

Acylation↗