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Biomedical subjects

B Christie

Publications and source records attributed to B Christie.

At least 55 records · Page 3Linked to original sources
PubMed1996

Hypotensive reactions to white cell-reduced plasma in a patient undergoing angiotensin-converting enzyme inhibitor therapy.

BACKGROUND: Hypotensive reactions to platelet transfusions performed with white cell (WBC)-reduction filters with negatively charged surfaces have been reported recently in patients taking angiotensin-converting enzyme (ACE) inhibitors. Experimental studies have shown that the filter material can activate bradykinin, which may cause symptoms in patients with reduced bradykinin catabolism. Symptomatic adverse reactions after the administration of fresh-frozen plasma (FFP) through a WBC-reduction filter have not been reported in a patient on ACE Inhibitor medication. CASE REPORT: A 58-year-old man with congenital coagulation factor V deficiency and hypertension treated with an ACE inhibitor was admitted for rehabilitation after orthopedic surgery. On 3 consecutive days, he received FFP through a WBC-reduction filter; within minutes of the beginning of each infusion, he experienced a drop in blood pressure, facial erythema, abdominal pain, and anxiety. When the infusions were stopped, symptoms quickly abated without treatment. Multiple prior transfusions of unfiltered FFP and FFP filtered through a WBC-reduction filter made by a different manufacturer, as well as subsequent transfusions of unfiltered FFP, had not produced such reactions. CONCLUSION: Facial flushing, hypotension, and abdominal pain after FFP administration in a patient on ACE inhibitor medication appeared to be associated with a specific type of WBC-reduction filter. This association and other reported studies suggest that special caution is warranted when patients who are treated with ACE inhibitors receive blood components administered through WBC-reduction filters capable of generating bradykinin.

Abdominal Pain↗
PubMed1995

Subthreshold synaptic activation of voltage-gated Ca2+ channels mediates a localized Ca2+ influx into the dendrites of hippocampal pyramidal neurons.

1. Whole cell recordings and high-speed fluorescence imaging were used to investigate the spatial and temporal characteristics of Ca2+ influx during synaptic activity in hippocampal CA1 pyramidal neurons. Brief, subthreshold trains of synaptic potentials elicited by Schaffer collateral stimulation produced transient increases in [Ca2+]i in the apical dendrites near the site of synaptic input. The rises in [Ca2+]i were not due to Ca2+ entry through N-methyl-D-aspartate (NMDA)-activated or non-NMDA-activated glutamate channels, but were reduced by low concentrations of Ni2+. Hyperpolarizing prepulses caused an increase in the synaptically evoked Ca2+ transients, whereas strong hyperpolarization during the train prevented the rise in [Ca2+]i. The data suggest that subthreshold synaptic activity can open low-voltage-activated (T-type) Ca2+ channels and produce a local increase in intradendritic [Ca2+]. Such local increases in [Ca2+]i may be important for modulating the strength of synaptic connections.

Animals↗
PubMed1992

Pulmonary dirofilariasis. The largest single-hospital experience.

Pulmonary dirofilariasis caused by Dirofilaria immitis, the dog heartworm, is a rarely reported pulmonary lesion. It most often appears as a solitary pulmonary nodule, often mistaken for a primary or metastatic lung tumor, and the diagnosis is not often established until thoracotomy with excisional lung biopsy is performed. Sporadic reports of pulmonary dirofilariasis in the United States total only 87 cases. The ten resections of pulmonary dirofilariasis at the Methodist Hospital in Houston, Tex, represent the largest reported series of cases originating at a single hospital. We present an overview of the pathogenesis of this disease, its clinical manifestations and epidemiologic features. The prevalence of pulmonary dirofilariasis appears to be increasing. Thus, surgeons and pathologists need to be aware of this etiology of granulomatous pulmonary lesions.

Adult↗
PubMed1991

Optical performance of an aspheric multifocal intraocular lens.

A five zone, centrosymmetric, multifocal intraocular lens has been developed using a design analysis approach which assumes that the optical image strength (intensity) achieved by an optical zone is linearly proportional to its aperture. The advantages of including an aspheric zone are discussed, and the optical performance of this IOL is characterized interferometrically. Optical resolution data have been obtained according to the ANSI procedure, using standard Air Force targets. These experimental data are compared with theoretical models of optical performance of diffraction-limited circular, annular, and compound circular-annular lenses.

Lenses, Intraocular↗
PubMed1988

Implementing meaningful CME as an essential component in a community hospital quality assurance plan.

The pursuit of high-quality patient care within a community hospital highlights the tenuous relationship between the hospital board and administration on one side and the voluntary medical staff on the other. Craddick describes the need to monitor and improve patient management, the commitment of physicians and administrators to high quality care, and the unfortunate failure of most hospital programs to go beyond paper exercises designed to satisfy the Joint Commission of Accreditation of Hospitals (JCAH). The American College of Surgeons summarizes current methods of monitoring the quality of patient care, and gives four examples of successful programs. The JCAH Manual sets standards for hospitals and medical staffs to achieve. However, thus far no one has described how a hospital's medical staff, board, and administration join forces to implement a comprehensive quality assurance program. This paper presents the experience of one community hospital in dealing with this problem over a two-year period.

Concurrent Review↗
PubMed1981

Obesity and essential hypertension. Hemodynamics, intravascular volume, sodium excretion, and plasma renin activity.

Systemic hemodynamics, intravascular volume, and plasma renin activity were determined in 135 lean, midly obese, or distinctly overweight subjects who were normotensive or had borderline or established essential hypertension. Cardiac output (but not index) was higher and peripheral resistance lower in obese than in lean subjects, except in borderline hypertension. Intravascular volume was increased in obese patients, and more so when corrected for body height; correction for body weight led to relative volume contraction. Intravascular volume correlated directly with cardiac output in the entire population, as well as in the subgroups. Intravascular volume correlated inversely with total peripheral resistance in all subjects and in each subgroup. Both correlations remained significant when an approximation was used to correct influences of obesity on total blood volume. Sodium excretion was higher in obese than in lean subjects. Thus, despite the expanded intravascular volume in obesity, the pathophysiologic relationship between systemic hemodynamics and intravascular volumes remains unchanged. Relatively low peripheral resistance in obesity may decrease the risk of systemic vascular disease. Nevertheless, since circulating volume is increased, the greater venous return adds an additional load to a left ventricle that is already burdened by a high afterload caused by arterial hypertension.

Adult↗