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Biomedical subjects

P A Flynn

Publications and source records attributed to P A Flynn.

13 recordsLinked to original sources
PubMed2006

A comparison of patient skin doses before and after replacement of a neurointerventional fluoroscopy unit.

AIM: After several embolization patients presented with radiation-induced skin injury in our neuroradiology centre, replacement of the centre's interventional fluoroscopy unit was prioritized. The aims of the present study were to compare the maximum skin dose delivered to each patient by the old and new units, to devise a method of estimating skin dose from the displayed dose-area product and to set local reference doses. MATERIALS AND METHODS: On the old unit, skin dose was measured using thermoluminescent dosimeters on 12 patients undergoing Gugliemi detachable coil embolization. Similar skin dose measurements were undertaken and the dose-area product was recorded for a further 12 patients on the new unit. RESULTS: The maximum skin dose measured on each patient on the old and new units had a mean of 2.2 Gy and 0.47 Gy, respectively, and a maximum of 4.1 Gy and 1.0 Gy, respectively. Maximum dose delivered to patients' skin by the new equipment was less than a quarter of the dose from the old equipment (p < 0.0001). CONCLUSION: The large reductions in skin dose reduced the risk of patients suffering radiation injury and confirmed the validity of replacing ageing interventional fluoroscopy equipment with modern equipment that incorporates dose management systems. As patient skin dose was correlated with dose-area product, local reference dose levels were set in terms of dose-area product; this enabled the operator to monitor the likely maximum patient skin dose during embolization procedures. Other centres could use a similar method to set their own reference doses.

Angiography, Digital Subtraction↗
PubMed2003

Superficial siderosis of the central nervous system many years after neurosurgical procedures.

Recurrent haemorrhage into the subarachnoid space causes superficial siderosis, which clinically manifests as cerebellar ataxia, sensorineural hearing loss, and myelopathy. Two patients developed clinical, radiological, and biochemical evidence of superficial siderosis many years after surgery. One had two posterior fossa operations, a left temporal craniectomy, and radiotherapy for a presumed brain tumour before developing clinical evidence of superficial sidersosis 37 years later. The other had small bilateral subdural collections from recurrent shunt revisions following posterior fossa surgery for a Chiari malformation, and then developed deafness and ataxia. The first patient currently has the longest recorded delay between presumed subarachnoid bleeding and clinical manifestations of superficial siderosis. Both patients provide further evidence that superficial siderosis of the central nervous system, a progressive neurodegenerative vascular condition, may be a delayed complication of neurosurgical procedures.

Adult↗
PubMed2001

Traumatic Brown-Séquard-plus syndrome.

BACKGROUND: In the 1840s Brown-Séquard described the motor and sensory effects of sectioning half of the spinal cord. Penetrating injuries can cause Brown-Séquard or, more frequently, Brown-Séquard-plus syndromes. OBJECTIVE: To report the case of a 25-year-old man who developed left-sided Brown-Séquard syndrome at the C8 level and left-sided Horner syndrome plus urinary retention and bilateral extensor responses following a stab wound in the right side of the neck. RESULTS: Magnetic resonance imaging demonstrated a low cervical lesion and somatosensory evoked potentials confirmed the clinical finding of left-side dorsal column disturbance. At follow-up, the patient's mobility and bladder function had returned to normal. CONCLUSION: This patient recovered well after a penetrating neck injury that disturbed function in more than half the lower cervical spinal cord (Brown-Séquard-plus syndrome).

Adult↗
PubMed1995

Evidence for superantigen involvement in cardiovascular injury due to Kawasaki syndrome.

Kawasaki syndrome (KS), the major cause of acquired heart disease in children, is an acute multisystem vasculitis frequently associated with the development of myocarditis and coronary artery abnormalities. Despite the widely held belief that KS is an infectious disease, its etiology has remained elusive. Recently, we and others have reported the selective expansion of V beta 2+ T cells in the peripheral blood of most patients in the acute, but not in the convalescent, phase of KS. These data were consistent with the concept that this illness is triggered by a bacterial superantigen. We report here that a patient who died of acute KS had selective expansion of V beta 2+ T cells in her myocardium and coronary artery. Sequence analysis of TCR beta-chain genes of V beta 2+ T cells from the myocardium showed extensive junctional region diversity. These observations, along with the demonstration of V beta 2 expansion in both the CD4+ and CD8+ T cell subsets, support the concept that the activation of infiltrating V beta 2+ T cells are involved in the cardiovascular damage associated with KS.

Base Sequence↗
PubMed1992

Cardiac issues in the pediatric emergency room.

A great variety of problems referable to the cardiovascular system can prompt a visit to the pediatric emergency room. From the initial presentation of congenital heart disease, to the subsequent life-long management of these patients, to miscellaneous problems like Kawasaki disease and chest pain, the front-line pediatrician must be skilled in the recognition and early management of myriad complaints. This article focuses on information that can assist the emergency pediatrician in the evaluation and treatment of the cardiac patient from arrival in the emergency room until transfer of care to the pediatric cardiologist or inpatient staff.

Acute Disease↗
PubMed1988

Phenotypic and genotypic characterization of tetracycline- and oxytetracycline-resistant Aeromonas hydrophila from cultured channel catfish (Ictalurus punctatus) and their environments.

Oxytetracycline-resistant (OTcr) and tetracycline-resistant (Tcr) Aeromonas hydrophila were isolated commonly from catfish intestinal contents and the water and sediment of catfish culture ponds, but less frequently in market catfish. Isolates demonstrated two resistance phenotypes, Tcr OTcr and Tcs OTcr, when plated directly on to MacConkey agar containing 30 micrograms of tetracycline or oxytetracycline per ml. Tcs OTcr isolates expressed Tcr after induction by 1 h of growth in tryptic soy broth containing 1 microgram of tetracycline per ml. Over 90% of the resistant aeromonads hybridized with DNA probes for class A or class E Tcr determinants; class E was twice as prevalent as class A. The distribution of class A and E Tcr determinants varied with the Tcr phenotypes. Prior to induction, 86% of isolates with class A determinants were Tcr as well as OTcr, while only 16% with class E determinant were Tcr. Three of 5 Tcr aeromonads without class A or class E determinants and 1 of 14 with class E determinants transferred Tcr to Escherichia coli.

Aeromonas↗
PubMedDate not supplied

Effectiveness of prostaglandin E1 in relieving obstruction in coarctation of the aorta without opening the ductus arteriosus.

The two main theories regarding the pathogenesis of coarctation of the aorta are the Skodaic hypothesis of ductal tissue constricting the aorta at the level of the insertion of the ductus arteriosus and the flow theory of decreased ascending aortic blood flow in the fetus, which results in associated isthmic narrowing and a localized shelf. To document that ectopic ductal tissue constriction can cause coarctation of the aorta in the absence of a patent ductus arteriosus, we report three cases of infants presenting with critical coarctation who responded to prostaglandin E1 infusion without opening the ductus arteriosus.

Alprostadil↗
PubMedDate not supplied

SSW test performance-intensity functions for hearing-impaired adults.

The present study investigated the effects of intensity on hearing-impaired adults' performance on the Staggered Spondaic Word (SSW) test. Fifteen adults having mild-to-moderate cochlear hearing losses were administered the 40-item SSW test which was subdivided into four groups of ten items each, and presented at different intensity levels (20, 30, 40, and 50 dB SL re the three-frequency, pure-tone average). Subjects' responses were used to generate performance-intensity functions. Scores were analyzed for overall, competing, and noncompeting conditions. No significant differences were found for these hearing-impaired listeners' performance for items presented at the standard 50 dB and those at the low sensation levels.

Adult↗