Search PubMed⌕ Search

Biomedical subjects

C Hardy

Publications and source records attributed to C Hardy.

83 records · Page 5Linked to original sources
PubMed1978

RNA metabolism, manganese, and RNA polymerases of zinc-sufficient and zinc-deficient Euglena gracilis.

The three major RNA classes from zinc-sufficient [(+Zn)] and zinc-deficient [(=Zn)] Euglena gracilis have been separated by affinity chromatography on oligo(dT)- and N-[N'-[m-(dihydroxyboryl)phenyl]succinamoyl]aminoethyl (DBAE)-celluloses. The total RNA content and the ribosomal and transfer RNA fractions are the same in (+Zn) and (=Zn) cells. IN (-Zn) cells, the messenger RNA fraction increases, and its altered base composition reveals additional bases and a 2-fold increase in the (G+C)/(A+U) ratio. Since the intracellular content of manganese increases in (-Zn) cells, we have examined its role in determining these changes in RNA composition. An increase in the Mn2+ content from 1 to 10 mM in assays with RNA polymerases I and II from (+Zn) cells and those with the single RNA polymerase from (-Zn) cells decreases the ratio of UMP to CMP incorporated from 1.7 to 1.0, 2.1 to 0.8 and 3.5 to 0.4, respectively. Thus, Mn2+ concentration can significantly alter the products of the enzymatic action of RNA polymerases from both (+Zn) and (-Zn) E. gracilis cells.

Base Sequence↗
PubMedDate not supplied

Balloon occlusion scintigraphy of aortopulmonary collaterals.

We evaluated two children with pulmonary atresia for coil embolization of aortopulmonary collateral vessels after placement of palliative aortopulmonary shunts. To determine vessel distribution and lung perfusion prior to collateral embolization, perfusion scintigraphy with technetium 99m-labeled macroaggregated albumin assessed pulmonary blood flow before and after balloon wedge catheter occlusion of the collaterals. In the first patient we found no perfusion defect during collateral occlusion, and we proceeded with embolization. In the second child, perfusion scintigraphy during occlusion of the collateral vessels demonstrated a filling defect, and embolization was not performed, thus avoiding the creation of a potential perfusion defect in this patient. Assessing the physiologic significance of aortopulmonary collateral vessels by utilizing temporary balloon occlusion of the collateral vessels and concurrent perfusion scintigraphy as an adjunct to selective angiography can provide a significant contribution to the safety and accuracy of coil embolization.

Aorta↗
PubMedDate not supplied

Congenital valvar aortic stenosis and abnormal origin of the right coronary artery: rare combination with important clinical implications.

Congenital valvar aortic stenosis in association with an abnormal coronary artery origin and distribution has not been previously reported. The right coronary artery arose in the left ventricular (LV) outflow tract and supplied much of the LV myocardium. Aortic valvotomy with standard antegrade cardioplegia resulted in infarction of the left ventricle. Aggressive attempts to ascertain the origin of the coronary arteries in right dominant coronary systems must be performed before any intervention in this group of patients.

Aortic Valve↗
PubMedDate not supplied

Pericardial substitute and emergency resternotomy: life-saving combination.

Retrosternal adhesions prolong operating time during reoperative pediatric cardiac surgery and promote myocardial injury. A case is presented in which a polytetrafluoroethylene pericardial substitute facilitated a rapid, life-saving emergency resternotomy in a moribund patient.

Cardiac Surgical Procedures↗
PubMedDate not supplied

MRI vs echocardiography in the evaluation of the Jatene procedure.

OBJECTIVE: Effective, noninvasive imaging studies are essential in the long-term assessment of patients who have had surgical correction of congenital heart disease. The initial study in most patients is echocardiography. The objective of the current study was to define the additional information that might be provided by MRI in comparison to echocardiography. MATERIALS AND METHODS: Electrocardiogram-gated MRI was used to evaluate 12 patients (mean age 4.5 years) who had undergone the Jatene (arterial switch) procedure for transposition of the great arteries. Magnetic resonance imaging and two-dimensional echocardiography were compared for their ability to demonstrate common complications of this procedure, namely, focal stenoses of the aortic and pulmonary anastomoses, right ventricular outflow tract, and both branch pulmonary arteries. RESULTS: A total of 24 focal stenoses were detected by MRI and echocardiography. The MR detected 22 of these (92%) and echocardiography detected 14 (58%). Ten of 17 stenoses involving the branch pulmonary arteries were identified only by MR. CONCLUSION: These results indicate that MRI is effective in evaluating post-operative complications of the pulmonary arteries in patients who have undergone the Jatene procedure and can provide information additive to echocardiography in these patients.

Anastomosis, Surgical↗
PubMedDate not supplied

How well do you know us?

As the percentage of people over age 65 continues to grow, medical groups must make provisions for this important segment of the patient population. Medical groups must do more than provide medical care; they must also concern themselves with special accommodations for seniors. Clyde Hardy has seen medical group practice from both sides. He recently retired from a long and prosperous career as a medical group administrator. Today he is a consumer of geriatric care. His advice to medical groups is insightful and entertaining.

Aged↗