Biomedical subjects

C G Cowley

Publications and source records attributed to C G Cowley.

7 recordsLinked to original sources

PubMed1999

Snare-assisted vascular access: a new technique.

Access to the central circulation can be difficult in small infants, particularly when normal anatomic landmarks have been altered. We describe a new technique that utilizes any existing central catheter to establish additional sites of vascular access. A 4 Fr end hole catheter is advanced under fluoroscopic guidance to the desired site of new vascular access. A 10-mm Amplatz snare catheter is advanced through the end hole catheter and the loop opened within the target vessel lumen. The snare is then used to guide percutaneous placement of a Cope wire through a 21-gauge needle and then to pull the wire into the central circulation. New access is then achieved by introducing an additional catheter over the guidewire. This technique has now been successfully utilized 16 times in 13 patients. Snare assistance is a safe and effective technique that provides a reliable means of establishing additional secure vascular access. Cathet. Cardiovasc. Intervent. 47:315-318, 1999.

Catheterization↗

PubMed1999

Treatment of infected left ventricular assist device using antibiotic-impregnated beads.

There is no well-established therapy for treating infections of heart-assist or artificial heart devices, a serious problem with life-threatening consequences. We used a promising new approach in which antibiotic-impregnated polymethylmethacrylate beads were placed around an implanted left ventricular assist device to control an external blood pump infection in a bridge-to-transplant patient. In this case report, we describe the potential of antimicrobial-impregnated polymethylmethacrylate beads for in situ control of infections involving external surfaces of cardiovascular devices.

Combined Modality Therapy↗

PubMed1999

Interventional cardiac catheterization advances in nonsurgical approaches to congenital heart disease.

Interventional cardiac catheterization offers increased therapeutic options to many patients with congenital heart disease. Over the past year encouraging results have been reported in hundreds of patients with interatrial communications, patent ductus arteriosus, and pulmonary artery stenosis requiring stenting. The Amplatzer (AGA Medical Corporation, Golden Valley, MN, USA) family of atrial septal, ventricular septal, and ductus occluding devices shows particular promise. Other studies support the efficacy and safety of established procedures such as balloon valvuloplasty and coarctation angioplasty. In some areas, such as transcatheter perforation of atretic pulmonary valves and endovascular stenting for coarctation of the aorta, our technical abilities may be advancing faster than our understanding of the ultimate clinical impact of our treatment. As interventional cardiac catheterization procedures continue to develop, they must be evaluated carefully against alternative treatments.

Angioplasty, Balloon↗

PubMed1996

The absence of ongoing immunoglobulin gene hypermutation suggests a distinct mechanism for c-myc mutation in endemic Burkitt's lymphoma.

PURPOSE: Burkitt's lymphoma is a malignancy of mature, immunoglobulin (Ig)-bearing B cells characterized by translocation between c-myc and Ig gene loci. A role for the juxtaposed Ig genes in the mutation and deregulation of c-myc expression typical of endemic Burkitt's lymphoma (eBL) has been proposed, but never proven. Our objective was to determine whether Ig gene hypermutation is ongoing in eBL. METHODS: We isolated Ig heavy-chain sequences from K962 eBL tumor cells using reverse transcription and polymerase chain reaction (PCR) amplification. The PCR product was ligated into Bluescript II vectors. Multiple subclones were sequenced and the variable regions were compared for evidence of ongoing Ig hypermutation. RESULTS: Six total single base substitutions were observed within four of the nine subclones studied. Four substitutions resulted in amino acid changes and two were silent. There was no clustering of mutations in hypervariable regions, or a high incidence of amino acid replacement or link substitutions, all of which are characteristic of Ig hypermutation. The observed mutations occurred at a rate consistent with Taq polymerase error. CONCLUSIONS: Our data indicate that in the eBL tumor sample K962, the mechanism underlying c-myc mutation is distinct from that which gives rise to Ig hypermutation.

Base Sequence↗

PubMedDate not supplied

Intracardiac yolk sac tumor: echocardiographic evaluation.

To our knowledge, this case of an abdominal yolk sac tumor with extensive cardiac involvement is the first to be reported in a pediatric patient. The report describes the echocardiographic findings of the tumor and the role of echocardiography in providing important information for patient management decisions.

Echocardiography↗

PubMedDate not supplied

Sinus node dysfunction in tuberous sclerosis.

Tuberous sclerosis is an autosomal dominant disease with potential for involvement of the skin, brain, lungs, kidneys, and heart. A case of prolonged sinus node pause and episodes of unresponsiveness in a 21-week-old infant with tuberous sclerosis is described. The infant subsequently underwent placement of an epicardial pacemaker. This case illustrates the importance of electrocardiographic studies in infants with tuberous sclerosis and seizure-like episodes.

Cardiac Pacing, Artificial↗

PubMedDate not supplied

Effects of T cells on platelet-derived growth factor-like protein secretion from endothelial cells.

The cause of accelerated graft arteriosclerosis after heart transplantation is unknown. To examine whether the interactions of T cells and endothelial cells (ECs) could contribute to the cause of this phenomenon, T cells were co-incubated with human umbilical artery endothelial cells (HUAEC) and human vein endothelial cells (HUVEC) and the resulting conditioned medium supernatant was assayed for the presence of platelet-derived growth factor (PDGF)-like protein. PDGF-like protein secretion was significantly greater from HUAECs co-incubated with T cells at T-cell/HUAEC ratios of 30:1 (6.9 +/- 1.1 fmol/10(6) ECs) and 10:1 (6.0 +/- 1.1 fmol/10(6) ECs) than the combined background secretion from HUAECs and T cells incubated separately (3.6 +/- 0.8 fmol/10(6) ECs) (p less than 0.05). PDGF-like protein secretion above background levels from HUAECs was significantly greater, however, than from HUVECs co-incubated with T cells at T-cell/HUVEC ratios of 30:1 (1.0 +/- 0.4 fmol/10(6) ECs) and 10:1 (0.75 +/- 0.36 fmol/10(6) ECs) (p less than 0.05). In four experiments, preincubation of HUAECs with gamma-interferon induced HLA-DR antigen expression but actually caused a decrease in T-cell-induced PDGF-like protein secretion above background levels (3.0 +/- 0.6 fmol/10(6) ECs) when compared to nonstimulated HUAECs (4.0 +/- 0.4 fmol/10(6) ECs; p less than 0.05). PDGF-like protein secretion was minimal at 1 hour and increased over time to a maximum at 24 hours. The conclusion is that T cells are capable of inducing secretion of a very potent mitogen, PDGF-like protein, from endothelial cells.(ABSTRACT TRUNCATED AT 250 WORDS)

3T3 Cells↗