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Biomedical subjects

C N Corder

Publications and source records attributed to C N Corder.

At least 19 recordsLinked to original sources
PubMed1998

Superior oblique tendon resection or inferior oblique muscle recession in vertical deviations.

This study reports the results on patients undergoing superior oblique (SO) tendon resections with or without inferior oblique (IO) muscle recession to correct vertical deviations. The design of this study was nonrandomized, baseline-controlled, and postsurgical versus presurgical and was performed in a solo practice affiliated with a university ophthalmology department. One hundred ninety-five patients underwent surgery. Patients were evaluated presurgically and postoperatively in the major fields of muscle action. Resections were based on measurements at 14 inches in the field of major function of the SO. The surgical approach was a radial, rather than circumferential, incision extending from the limbus to the tarsus parallel to the lateral border of the superior rectus, followed by resection of the SO tendon. Surgery resulted in improved fusion in 78% of the cases. Average deviation in the left superior oblique field in SO tendon resection only (n = 14) was reduced from 11.0 to 1.7 prism diopters, and fusion improved 85% after treatment. In 181 cases of SO tendon resection or IO recession, the left superior oblique field was reduced from 15.8 to 3.6 diopters. SO tendon resection was successfully utilized to treat underacting SO muscle and vertical deviations. A radial incision facilitated the surgical procedure, and its use is recommended to those performing the surgery.

Adolescent↗
PubMed1994

Effects of lovastatin on ApoA- and ApoB-containing lipoproteins. Families in a subpopulation of patients participating in the Monitored Atherosclerosis Regression Study (MARS).

To establish whether lovastatin, an inhibitor of 3-hydroxy-3-methylglutaryl coenzyme A (HMG CoA) reductase, exhibits a specific effect on apolipoprotein (apo) A- and apoB-containing lipoproteins, 63 subjects, a subset of the 270 Monitored Atherosclerosis Regression Study (MARS) patients with hypercholesterolemia (190 to 295 mg/dL) and documented coronary artery disease, were randomized into either lovastatin 40 mg twice daily or matching placebo tablets twice daily. Both groups consumed a diet containing 27% calories as fat (polyunsaturated fat/saturated fat ratio, 2.85) and a daily cholesterol intake of less than 250 mg. The plasma lipid and apolipoprotein profiles were determined at the time of randomization and after 2 years of treatment, and the levels of apoA- and apoB-containing lipoprotein families were measured after 2 years of treatment. After this treatment period, the drug group was characterized in comparison with the placebo group by significantly reduced levels of total cholesterol (33%), triglycerides (30%), very-low-density lipoprotein cholesterol (36%), low-density lipoprotein cholesterol (43%), apoB (36%), apoC-III (18%), and apoE (17%) and slightly but insignificantly increased levels of high-density lipoprotein cholesterol (6%) and apoA-I (1%). The 2-year levels of lipoprotein containing apoA-I but no apoA-II (LpA-I) and lipoprotein containing both apoA-I and apoA-II (LpA-I/A-II) particles separated by immunoaffinity chromatography on an anti-apoA-II immunosorber did not differ between the two treatment groups. However, the apoB-containing lipoprotein (Lp) families defined by apolipoprotein composition and separated by immunoaffinity chromatography on anti-apoA-II and anti-apoC-III immunosorbers were affected in a selective manner.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

Once-daily, extended-release gemfibrozil in patients with dyslipidemia. The Lopid SR Work Group I.

This randomized, parallel-group, multicenter clinical trial compared a newly developed, once-daily, extended-release formulation of gemfibrozil (Lopid SR) and gemfibrozil twice daily (Lopid) in terms of lipid-regulating effects and toxicity. Patients were men and women with elevations of low-density lipoprotein cholesterol and low levels of high-density lipoprotein cholesterol. The trial consisted of a 1-week screening period, an 8-week diet baseline period (Step One Diet), and a 24-week double-blind treatment period (extended-release gemfibrozil 1,200 mg once daily vs gemfibrozil 600 mg twice daily). At the end of the trial, the 2 treatment groups showed comparable improvements in all primary lipid factors: mean percent changes in triglyceride, high-density lipoprotein cholesterol, and low-density lipoprotein cholesterol were -32, +10 and -10% for extended release (n = 325) and -36, +11 and -10% for twice daily (n = 330). The 90% confidence interval for the relative difference between the treatment means fell within the equivalence bounds of +/- 35% for all 3 factors, demonstrating equivalence of efficacy. Adverse events were reported at low rates and were similarly distributed in frequency and intensity between treatment groups; they were preponderantly mild or moderate, and gastrointestinal effects were the most frequent. The once-daily formulation of gemfibrozil may afford better control of dyslipidemia through improved compliance by patients who have this asymptomatic disease.

Adolescent↗
PubMed1993

Effect of gemfibrozil on fatty acids in lipid fractions of plasma from patients with hypertriglyceridemia.

The fatty acid composition of plasma triglycerides, phospholipids, and cholesterol esters have been studied during gemfibrozil (G)-induced lipid-lowering treatment in six patients with hypertriglyceridemia. Gemfibrozil caused significant plasma triglyceride reductions from 776 +/- 573 to 226 +/- 82 mg/dL (P < .001). Gemfibrozil therapy also caused significant changes in the plasma lipid fatty acid composition, mainly by increasing palmitoleic acid (16:1) in triglycerides (2.1-5.6%) and cholesterol esters (2.2-3.7%), concomitant with the significant decrease in the content of the linoleic acid (18:2) in phospholipids (20.1-16.0%) and triglycerides (18.0-15.2%). The ratio of unsaturated fatty acids (20:3 + 20:4/18:2) was increased in the phospholipid fraction. These findings support a G effect on the desaturation of fatty acids in patients with hypertriglyceridemia. Because fatty acid composition was significantly altered by G, those biologic systems dependent on the pattern of fatty acids may be modified in clinical important ways.

Fatty Acids↗
PubMed1993

Effect of cilazapril on exercise tolerance in congestive heart failure.

Cilazapril (C), an angiotensin-converting enzyme inhibitor with effective antihypertensive efficacy, was examined for its ability to alter exercise tolerance testing (ETT) and respiratory oxygen uptake in 33 patients with congestive heart failure (CHF). C was administered in capsules daily to patients with New York Heart Association Class II or Class III CHF for 12 weeks, in parallel double-blind treatment groups of 0 mg (n = 8), 0.5 mg (n = 8), 1.0 mg (n = 9), and 2.5 mg (n = 8). The blood pressure (BP) was reduced by 2.5 mg C: systolic BP (SBP) from 126 to 114 mm Hg; diastolic BP from 76 to 69 mm Hg. The maximum heart rate (MHR) during ETT was increased by 2.5 mg C from 137 to 143 bpm, as was the double product (MHR x maximum SBP x 0.01) from 237 to 251. There was an insignificant change in duration of exercise (548-610 s), anaerobic threshold (AT), and maximum oxygen uptake (14.1-15.7 ml/kg/min). The results suggest a positive effect of 2.5 mg C on energy utilization in CHF patients.

Aged↗
PubMed1993

Lipid peroxide levels in type II hyperlipoproteinemic subjects.

The purpose of this study was to evaluate, under the most rigorous precautionary measures against in vitro oxidation, whether the baseline lipid peroxide levels in hypercholesterolemic subjects were higher than those in normolipidemic subjects. Two methods were employed: thiobarbituric acid (TBA), and hemoglobin-methylene blue (HbMB). Blood was collected into EDTA tube and centrifuged at 4 degrees C for 30 min to collect plasma, then protected from in vitro oxidation with preservatives and N2. Serum was from blood samples allowed to clot at 20 degrees C for 1 h, then protected from oxidation. Determination of lipid peroxide was carried out within 2 h of blood collection. Results from 35 hypercholesterolemic and 34 control subjects showed that lipid peroxide levels obtained from both methods were significantly higher in serum than in plasma for both groups, suggesting a greater rate of lipid peroxidation occurred in serum during clot formation. However, no significant difference in lipid peroxide levels was found between patients and controls in either serum or plasma by either assay method. No correlation existed between lipid peroxide values and plasma cholesterol or LDL-cholesterol levels. These results suggest that the mechanism for a higher tendency towards atherosclerosis in hypercholesterolemic subjects is not related to baseline levels of plasma lipid peroxide.

Blood Specimen Collection↗
PubMed1992

Lipid and apolipoprotein levels during therapy with pinacidil combined with hydrochlorothiazide.

This study determined the effect of pinacidil on the concentration of plasma lipids and apolipoproteins in male patients previously equilibrated with 25 mg hydrochlorothiazide twice daily. Pinacidil therapy given to 52 hypertensives at 25 to 100 mg daily for 8 weeks resulted in a reduction of systolic and diastolic blood pressure concurrently to reductions in plasma cholesterol and triglycerides with no change in low density lipoprotein-cholesterol (LDL-C) and high density lipoprotein-cholesterol (HDL-C). There was an associated decrease in apolipoproteins (Apo)B, C-III and E and elevation in ApoA-I. A parallel placebo group of 44 patients experienced reduction in diastolic blood pressure and an elevation in ApoA-I. These changes indicate that pinacidil will be a useful antihypertensive agent having properties on lipoprotein metabolism which would favor decreased risks of atherosclerosis.

Adult↗
PubMed1992

Clinical effect of indolidan in congestive heart failure.

Indolidan (IN) experimentally inhibits type IV phosphodiesterase. It was administered to twelve patients (age 64 +/- 15 years) with New York Heart Association (NYHA) class 2-3 congestive heart failure in which digoxin and diuretic therapy were continued. IN was administered i.v. at 1,180 +/- 340 micrograms (15 micrograms/kg) over two hours. After 24 hours, IN was given p.o. at 231 +/- 44 micrograms. The time course effect of IN i.v. revealed an increase in cardiac index and a decrease in pulmonary capillary wedge pressure and blood pressure. Daily oral administration of IN or placebo was carried out for up to 3 months. There were no significant hemodynamic changes of chronically administered IN. The maximum oxygen uptake increased in placebo relative to IN therapy. IN tended to be arrhythmogenic as evidenced by a general increased frequency of ventricular premature contractions of both single and paired type. Therefore, IN had some hemodynamic efficacy on acute i.v. and p.o. administration but not during chronic therapy, and there was negative safety features of arrhythmias.

Administration, Oral↗
PubMed1991

The effect of food on pharmacokinetics and pharmacodynamics of fenoldopam in class III heart failure.

Eighteen patients with New York Heart Association class III congestive heart failure were given single 100 mg oral doses of fenoldopam with food or fasting in a random-order single-blind crossover trial. Before and after each fenoldopam dose, thermodilution cardiac output, right atrial pressure, pulmonary artery pressure, and pulmonary capillary wedge pressure (PCWP) were measured with a balloon-tipped pulmonary artery catheter, and heart rates and blood pressures were recorded with an automated sphygmomanometer. Compared with fasting, bioavailability of fenoldopam was decreased significantly when administered with food: mean peak plasma fenoldopam level decreased from 26.5 (+/- 4.1 SEM) ng/ml to 10.9 (+/- 1.7 SEM) ng/ml (p = 0.0004) and mean area under the concentration-time curve was decreased from 44.7 (+/- 5.8 SEM) ng.hr/ml to 26.8 (+/- 4.1 SEM) ng.hr/ml (p = 0.0001). Fenoldopam administration to fasting patients resulted in decreases in mean arterial pressure, systemic vascular resistance, and PCWP and significant increases in cardiac index without change in heart rate. The maximum changes in mean cardiac index, systemic vascular resistance, and PCWP were greatest 1 hour after oral administration and did not persist beyond 3 hours after administration. In fasting patients, changes in cardiac index were correlated with plasma fenoldopam levels, whereas changes in PCWP and mean arterial pressure did not correlate significantly with the observed fenoldopam level.

2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-ben↗
PubMed1991

Antihypertensive effect of tiapamil from ambulatory and clinic methods.

Tiapamil (T), a calcium antagonist, was studied in hypertensive patients by 1) automatic monitor of blood pressure (AMBP), and 2) cuff and stethoscope clinic blood pressure (CBP). Systolic (SBP), diastolic (DBP) pressures and heart rate were measured. Patients (n = 58) received four weeks of placebos given twice daily. Baseline 24 h AMBP (wk 4), 147 +/- 18 (SBP) and 91 +/- 8 (DBP) mmHg; and CBP (wk 3 and 4), 152 +/- 16 (SBP) and 102 +/- 9 (DBP) were established. Then, patients received double-blinded therapy (wk 5-10) of twice daily tablets of placebo (n = 9); Level I T, 150-300 mg (n = 24); or Level II T, 450-600 mg (n = 25): i.e. 0 to 1,200 mg T/d. Significant responses, measured by AMBP (wk 10), were noted only at Level II T: SBP (-10.5 +/- 12.4) and DBP (-5.6 +/- 7.8) mmHg. However, CBP (wk 9 and 10) responded at Level I T (SBP, -7.7 +/- 12.4/DBP, -5.8 +/- 6.4) and Level II T (SBP, -8.8 +/- 9.4/DBP, -9.7 +/- 7.8 mmHg). There was minimal correlation (r = 0.16) of pressure responses to T measured by 24-h AMBP versus CBP methods. Therefore, T effectively lowered SBP and DBP, but individual responses measured by AMBP did not predict those measured by CBP. There was no effect of T on heart rate. Dizziness was noted in 12 percent of patients on T.

Adolescent↗
PubMed1990

Lp(a) and plasma triglyceride-rich lipoproteins.

Based on our studies showing an interaction between Lp(a) and ApoB-containing lipoproteins (ApoB-Lp) and the observation that the interacting ApoB-Lp were somewhat enriched in triglyceride (TG), we have initiated studies to explore this potential relationship of Lp(a) and TG-rich lipoproteins. In exploring Lp(a)'s incidence in hypertriglyceridemic subjects, we found a significantly reduced incidence (31%, p less than 0.05) of Lp(a) levels greater than 9 mg/ml when compared to both normolipidemic (61%) and subjects with coronary heart disease (49%). Analyses of a second group of hypertriglyceridemic subjects (n = 68) demonstrated that only 15% of subjects with TG greater than 400 mg/dl (n = 20) had levels of Lp(a) greater than 9 mg/dl while 52% of those with TG levels less than 400 mg/dl (n = 48) had this level of detectable Lp(a). These studies point to an inverse relationship between plasma TG and Lp(a) levels.

Coronary Disease↗
PubMed1989

CI-924 effects on plasma lipids in patients with type II and type IV hyperlipoproteinaemia.

CI-924 (CI), 5,5'-[[1,1'-biphenyl]-2,5-diylbis(oxy)]bis[2,2- dimethylpentanoic acid] is chemically similar to gemfibrozil. Patients with Type II (n = 13) and Type IV (n = 22) hyperlipoproteinaemia (HLP) were maintained 12 weeks on a baseline diet containing 55% sugar, 15% protein 30% fat and less than 300 mg cholesterol daily to stabilize weight and lipids. They were then entered in a parallel group double-blinded protocol and received 0, 300, 600, or 1200 mg CI p.o. daily for 12 weeks. CI consistently elevated anti-atherogenic HDL and lowered VLDL at 600 mg/day in both Type II and Type IV HPL at 8 weeks. In Type II patients, CI lowered cholesterol, decreased LDL/HDL and increased ApoA-I. In Type IV patients, CI also lowered TC while elevating LDL and ApoA-II. CI had no effect on Apo-B, LDL-ApoB, or Apo-E.

Apolipoproteins↗
PubMed1989

Atheromatous embolism: varied clinical presentation and prognosis.

Microemboli composed of atheromatous debris can produce sudden failure of one or many organ systems. The soft tissues of the lower extremity are almost always involved, and may sustain the only significant injury. Atheromatous embolization occurs more commonly than is recognized, and its incidence may be increasing. We report ten cases that demonstrate the variability in presentation and prognosis. These data and a review of the existing literature suggest an extremely grave prognosis in patients with generalized organ system involvement, as opposed to those patients with involvement of the lower extremity only. Treatment consists of general supportive care. Anticoagulation or lytic therapy appears to be of no benefit, and may actually contribute to embolization. We discuss new pharmacologic agents as possible treatment for the intense local ischemia, and recommend selective use of lumbar sympathectomy in cases of impending loss of lower extremity tissue.

Aged↗
PubMed1987

Efficacy of nifedipine gastrointestinal therapeutic system in combination with beta blockers in the management of exertional angina. A multicenter study of 54 patients.

This multicenter study assessed the efficacy of a new formulation of nifedipine in 54 patients with stable angina pectoris receiving beta-blocker therapy. This once-daily preparation of nifedipine was administered in double-blind fashion in doses of 30, 60, and 90 mg. All patients experienced pain-limited exercise at placebo baseline treadmill testing. Eight hours post-dose exercise testing resulted in a significant increase in time to onset of angina for all three dose levels of nifedipine but not for placebo. Exercise testing 24 hours after dosing showed significant improvement in time to angina and total exercise time for patients receiving 60-mg and 90-mg doses but not for the 30-mg or placebo categories. These preliminary results suggest that this new formulation of nifedipine is beneficial when added to stable doses of a beta blocker in patients in whom angina is still exhibited during exercise testing.

Adrenergic beta-Antagonists↗
PubMed1985

Catecholamine, adenosine triphosphate, and P-creatine levels in decapitated whole mouse brain.

The levels of norepinephrine, epinephrine, dopamine, adenosine triphosphate, and P-creatine were measured in whole mouse brain collected under two conditions: 1) the decapitated head was immediately plunged into liquid nitrogen (nonanoxic tissue); or 2) the tissue was allowed to remain anoxic before the quick-freezing procedure. The substrate levels were significantly decreased in brain anoxic for only 30 sec. The catecholamine levels in nonanoxic mouse brain appear to be higher than levels previously reported in brains collected with microwave irradiation or by decapitation with rapid dissection of tissue before it was frozen.

Adenosine Triphosphate↗