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Biomedical subjects

A Ryan

Publications and source records attributed to A Ryan.

At least 163 records · Page 9Linked to original sources
PubMedDate not supplied

Coil occlusion of the patent ductus arteriosus: lessons learned.

PURPOSE: To review the clinical outcomes of catheter-directed coil occlusion (coil occlusion) of persistently patent ductus arteriosus (PDA) at a pediatric tertiary care hospital. METHODS: A retrospective review of all patients referred to the Cardiac Catheterization Laboratory for coil occlusion at our institution was performed. Twenty-one consecutive patients (12 female) underwent coil occlusion and follow-up between May 1995 and December 1997. We undertook PDA occlusion if: (a) the PDA narrowed to less than 4 mm on echocardiogram and (b) the minimum body weight was approximately 10 kg. Standard right and retrograde left heart catheterization was performed, followed by coil occlusion. Color-flow mapping (CFM) was used intra-procedurally to confirm occlusion of the PDA with a follow-up study several weeks later. RESULTS: The median age and weight of the patients were 33 months and 13.2 kg, respectively. Fourteen patients received one coil, with six requiring a second coil and one requiring multiple coils. Initial follow-up was at a median of 2.4 months. At latest follow-up, 2 patients still have persistent flow at the ductal level. The coils were deployed without complication or embolization. CONCLUSIONS: A review of our first 21 cases demonstrated three important lessons: (1) the maximum diameter of the PDA suitable for coil occlusion is approximately 3 mm; (2) CFM must show complete obliteration of flow in the catheterization lab in order to ensure occlusion of the PDA at follow-up; and (3) the Jackson detachable system allows for precise placement of the coil, often within another coil.

Adolescent↗
PubMedDate not supplied

Effect of basic fibroblast growth factor on normal tympanic membrane.

PURPOSE: Basic fibroblast growth factor (bFGF) is mitogenic for the cell types that constitute the tympanic membrane and has been shown to potentiate tympanic membrane healing. The purpose of this study is to investigate the direct effect of bFGF application on normal tympanic membrane. MATERIALS AND METHODS: bFGF was applied to the normal tympanic membrane of 10 guinea pigs via either the external auditory external canal or the middle ear. The drug (400 ng) was delivered on days 0, 1, and 2. The contralateral ear was used as a control. The effects were assessed on day 3. RESULTS: The cumulative area and the average area of blood vessel in each session of TM was greater after bFGF application than placebo. The number of vessels remained unchanged. A proliferation of keratinocytes was observed. CONCLUSION: These results suggest that bFGF induces a vasodilatation in the tympanic membrane thereby increasing blood supply. This might explain the acceleration of healing of TM perforations after bFGF application.

Animals↗
PubMedDate not supplied

An evaluation of changes in composition and contamination of salvaged blood from the cardiopulmonary bypass circuit of pediatric patients.

OBJECTIVE: To review changes that occur during an 18-hour period in composition and bacterial contamination of blood salvaged from the cardiopulmonary bypass (CPB) circuit of pediatric patients. DESIGN: Prospective, blinded study. SETTING: Pediatric tertiary multidisciplinary intensive care unit. PATIENTS: One hundred and one children who underwent CPB. OUTCOME MEASURES: The degree of bacterial contamination and biochemical and hematologic alterations of blood salvaged from the CPB and any increased blood loss associated with reinfusion of this blood. INTERVENTION: The salvaged blood from the CPB circuit was collected into 1 L blood transfer packs after CPB. This blood was then stored at room temperature for 18 hours. Sampling occurred immediately after CPB and at 6 and 18 hours for biochemic and hematologic assay and for the detection of bacterial organisms. The amount of chest drainage loss was assessed in the first 18 hours after bypass. The type and amount of intravenous fluid infused also was recorded. RESULTS: Bacterial contamination occurred in three samples (two at 6 hours and in one of the preceding at 18 hours) of the 101 units of salvaged blood. All three positive cultures grew a coagulase-negative staphylococcus. Sodium and potassium remained within normal physiologic values. The glucose values declined from 15.8 to 13.4 mmol/L, and the hemoglobin values increased from 0.4 to 0.5 gm/dl. The reinfusion of the salvaged blood (and any other blood or blood products) to 31 of the 101 patients averaged 14.2 ml/kg/24 hr, with a mean chest drainage loss of 4.9 ml/kg/24 hr. The remaining 70 patients received 12.5 ml/kg/hr of either plasma expanders or blood, with a mean chest drainage loss of 6.0 ml/kg/24 hr. CONCLUSIONS: The results of this study demonstrate minimal chemical deterioration and limited microbiologic contamination in blood that was salvaged from the CPB circuit and stored at room temperature for an 18-hour period. No increase in postoperative bleeding was noted from the use of this blood. These results suggest it may be safe to reinfuse salvaged blood after CPB in pediatric patients for up to 18 hours; however, a prospective clinical trial is needed to validate these findings.

Blood↗
PubMedDate not supplied

Molecular differences between RER+ and RER- sporadic endometrial carcinomas in a large population-based series.

Studies, to date, have suggested that there are distinct molecular differences between microsatellite stable (RER(-)) and unstable (RER(+)) solid tumors, such as colorectal carcinoma. We investigated a range of molecular events including mutation frequency of K-ras, microsatellite instability within the coding region of TGF-beta RII, BAX, and IGF-IIR, loss of expression of p53, hMLH1, hMSH2, hMSH6, and PTEN, and methylation of hMLH1, hMSH2, and PTEN within a large population-based series of sporadic endometrial carcinomas to establish whether there are distinct differences between replication error repair (RER(+)) and RER(-) cases. RER(+) endometrial carcinomas tended to be diploid with normal p53 expression, compared with RER(-) cases. Mutations in TGF-beta RII, IGF-IIR, and BAX were rare, but there was a strong association between mutation and RER(+) status. Methylation and loss of hMLH1 expression were significantly more common in RER(+) cases, as was methylation of PTEN. K-ras mutations were equally frequent in RER(+) and RER(-) cases. Despite the absence of distinct clinicopathological differences between RER(+) and RER(-) cases in this series of sporadic endometrial carcinomas, our results confirm that there are molecular differences between RER(+) and RER(-) cases, but the molecular events occurring in RER(+) endometrial carcinomas differ from those seen in RER(+) colorectal carcinomas.

Adaptor Proteins, Signal Transducing↗
PubMedDate not supplied

Neutralizing antibodies against basic fibroblast growth factor influence the healing of traumatic tympanic membrane perforations.

The beneficial effects of basic fibroblast growth factor (bFGF or FGF-2) in healing of tympanic membrane (TM) perforations have been demonstrated in animal models, and this study was conducted to investigate the effect of neutralizing anti-FGF-2 antibodies on acute tympanic membrane perforation healing. Anti-FGF-2 rabbit polyclonal antibodies were applied to traumatic TM perforations in guinea-pigs on days 0, 1, 2 and 3, whilst the opposite ear was treated with normal rabbit serum. On day 4, the perforation area was assessed, and the histological structure of the scar was studied. The average opening was larger in the neutralizing anti-bFGF-treated group, but the difference was not statistically significant. Histological analysis showed that scars treated with neutralizing anti-bFGF contained significantly less epithelial cells and less mononuclear cells. They also contained less fibroblasts and less vessels, but this difference was not significant. These data suggest that FGF-2 is one of the factors involved in the control of epithelial cells proliferation and mononuclear cell invasion in the initial phase of TM perforation healing. Neutralizing anti-bFGF antibodies could be of use in reducing the inflammation during the healing of TM perforations or to create animal models of chronic tympanic membrane perforations.

Animals↗
PubMedDate not supplied

Development of hearing loss in kanamycin treated chinchillas.

Behaviorally determined auditory thresholds of chinchillas were monitored before, during and after daily administration of kanamycin sulfate (200 mg/kg per day). Drug treatment was terminated as soon as a shift in high-frequency thresholds was observed. In surviving animals, hearing loss spread toward lower frequencies and stabilized after eight to nine days. The stable hearing loss was limited, on the average, to frequencies above 3 kHz. The magnitude of the loss was constant across frequencies and averaged about 40 dB. Virtually complete outer hair cell loss was seen in the basal portion of the cochleae of all surviving animals.

Animals↗
PubMedDate not supplied

Antigenicity of the guinea pig's tympanic membrane.

The immunogenicity of the middle ear constituents is a matter of prime importance. In this work, the authors were interested in the antigenicity of the guinea pig's tymphanic membrane. They reached the conclusion, after developing an antiserum (IgG), that the tympanic membrane of the guinea pig can be antigenic in the rabbit. After purification and absorption, a cross-reactivity remains between the tympanic membrane and the mucosae of the upper respiratory system.

Animals↗
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Ketamine-fentanyl-midazolam infusion for the control of symptoms in terminal life care.

In this report, we describe nine terminally ill patients with metastatic cancer who were treated with an intravenous infusion consisting of ketamine (2 mg/ml)/fentanyl (5 micrograms/ml)/midazolam (0.1 mg/ml) (K/F/M) to control pain after traditional analgesic therapies were unsuccessful. In addition to pain, all patients exhibited some symptoms of cognitive compromise and agitation. After initiation of the K/F/M infusion, all patients exhibited some degree of qualitative improvement in these symptoms as well as in overall pain control. We feel that these observations warrant reporting of the efficacy of this infusion for the treatment of uncontrolled pain and agitation in terminally ill patients when the traditional methods of pain control are inadequate.

Aged↗
PubMedDate not supplied

The influence of pyridoxine in diabetic peripheral neuropathy.

To determine the role of pyridoxine in the treatment of diabetic peripheral neuropathy, 18 symptomatic diabetic patients were treated with vitamin B6 or placebo in a double-blind controlled study. Only one patient had a low plasma pyridoxal phosphate level at the start of the study. After 4 mo of treatment with pyridoxine hydrochloride (50 mg three times daily) 6 of 9 pyridoxine-treated and 4 of 9 placebo-treated patients noted significant relief from their neuropathic symptoms. There was no difference between the two groups with regard to fasting plasma glucose, motor nerve conduction velocity, or ophthalmologic examination at the beginning or at the conclusion of the study. Our results suggest that vitamin B6 deficiency is not a factor in the etiology of diabetic peripheral neuropathy. Furthermore, treating diabetic peripheral neuropathy with high dose vitamin B6 or placebo results in a similar frequency of symptomatic improvement.

Adult↗
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The early postnatal development of the cochlear vasculature in the gerbil.

The blood vessels of the cochlea were studied from birth up to adult age in the gerbil. Even at birth the principal vascular arrangement could be identified in the external wall. However, the early circulatory mainstream appeared even more predominantly radial apico-basal over radiating arterioles-arteriovenous anastomoses-collecting venules than at later stages. At birth, only small sections of capillaries could be observed in the stria vascularis. Stria vascularis achieved its adult vascular appearance rapidly between 8-10 days after birth (DAB). The rapid development of stria vascularis immediately preceded the development of cochlear function and may have been related to the development of the ionic composition of endolymph. At birth the vessel of the basilar membrane showed many large vascular connections with the collecting venules in the scala tympani of the external wall but very few supplying and draining ramifications on the medial side of the vessel. This suggests that the vessel of the basilar membrane originates from the external wall vessels, not from the spiral lamina vessels as has previously been supposed. The peripheral vascular connections degenerated rapidly after birth. The vessel, being very large at birth, degenerated completely by 15 to 20 DAB, ultimately disappearing in the basal turn. The degeneration suggests that its major importance may be during embryonic stages, with great probability for the development of the organ of Corti.

Aging↗
PubMedDate not supplied

Focus on ageism.

Explore the source record for details and available documents.

Aged↗
PubMedDate not supplied

Improving discharge planning.

In ward 9 of the Nursing Development Unit at Whiteabbey Hospital, Newtonabbey, Northern Ireland, developments and innovations are channelled through the use of working groups which are essentially the pivot on which the unit rotates. This article details the activities of one of these groups, the discharge planning group.

Aged↗