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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
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↗
PubMed1985

Enkephalins: immunomodulators.

Our original studies of the enkephalins were centered on behavioral stress and brain dopaminergic interactions. More recently we discovered the enkephalins to be immunomodulators as evidenced by their enhancement effects on lymphocyte blastogenesis in mice, increases in the sizes of the thymus or spleen in rodents, and prolongation of survival of BDF1 mice inoculated with attentuated L1210 cells. Finally, in studies of human blood samples from both normal volunteers and cancer patients, the enkephalins were demonstrated to stimulate active T cell rosettes and natural killer cell activities (in vitro). These studies support our hypothesis that, in stress, the enkephalins modulate the effects of steroid hormones on the immune system.

Acoustic Stimulation↗
PubMed1984

Levels of the oxytocin-associated and vasopressin-associated neurophysins in plasma and their responses in essential hypertension.

A group of 89 individuals with essential hypertension was evaluated with several measurements including the neurophysin believed to be the human oxytocin neurophysin (OT-Np), and the human vasopressin neurophysin (VP-Np). The neurophysins are proteins synthesized within cells of the supraoptic and paraventricular nuclei in conjunction with their respective hormones oxytocin and vasopressin as part of a common precursor molecule and so may reflect the simultaneous presence in plasma of their associated hormones. A poor but statistically significant correlation was noted between levels of OT-Np and renin activity in plasma (PRA) either supine (r = 0.248) or erect (r = 0.255). Levels of OT-Np averaged 1.75 ng/ml and were inversely correlated with creatinine (r = -0.252), supine blood pressure (r = -0.450), plasma volume (r = -0.327), and 24-hour urine sodium (r = -0.313). Levels of Ot-Np could be suppressed by infusion of physiologic saline. Levels of OT-Np were lower in the volume expanded state and were positively correlated with the quantity of sodium excreted into a 24-hour urine collected after the infusion (r = 0.426) and inversely correlated with the supine systolic (r = -0.379) and supine diastolic (r = -0.455) blood pressures recorded after the infusion of saline. Oestrogen, a stimulus to the secretion of OT-Np, did not account for the elevation of OT-Np observed in the study, since mean levels of oestradiol (E2) in a subset of the patients with elevated OT-Np (E2 = 36 pg/ml) were not different from levels in subjects with lower values of OT-Np (E2 = 45 pg/ml).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1983

Pyruvate and lactate levels in oviducts of cycling, pregnant, and pseudopregnant mice.

Pyruvate and lactate were measured in oviducts during the first 5 days following ovulation in cycling, pregnant, and pseudopregnant mice, to determine how oviductal metabolism might change to promote the availability of these substrates to the early embryo. The postovulatory peak in ampullar pyruvate was most evident in the 12-h pregnant oviduct, 3.19 mmol . kg-1. This increase at +12 h was related to a decrease in lactate dehydrogenase (LDH) activity, compared to cycling animals, observed at this time. Although cycling animals showed a significant increase in isthmic pyruvate at +3 h, no change in isthmic pyruvate was observed in either mated group through the postovulatory period. Isthmic LDH activity was also unchanged in cycling or mated animals through this period. Ampullar lactate in both mated groups was elevated at 12 to 24 h after ovulation, a pattern similar to that seen in cycling animals. Isthmic lactate levels also increased after ovulation in all groups, but in the pregnant group the lactate remained elevated (25-28 mmol . kg-1) through 72 h, while concentrations in the cycling and pseudopregnant animals, returned to low levels (14-16 mmol . kg-1) by 48 h. The patterns of pyruvate and lactate, especially those in the pregnant animals, seem suited to providing these metabolites at levels near those required for optimal in vitro embryo growth. The +12 h ampullar pyruvate peak noted in mated animals implies a specific response to the mating stimulus. Prolongation of increased isthmic lactate levels only in pregnant animals suggests a response of the oviduct to the viable embryo.

Analysis of Variance↗
PubMed1982

Quantitative histochemical measurement of pyruvate and lactate in mouse oviduct during the estrous cycle.

Pyruvate and lactate are important energy sources for preimplantation embryos cultured in vitro. The purpose of this study was to determine in vivo levels of these substances in mouse oviductal tissues throughout the estrous cycle. Quantitative histochemical assays were developed to analyze these metabolites in submicrogram samples of freeze-dried ampullar and isthmic oviduct. The potential for other alpha-keto acids to interfere with the pyruvate assay was assessed and found to be minimal with this procedure. The importance of the collection method in maintaining in vivo metabolite levels was demonstrated by the marked changes observed with extended anoxia or pentobarbital anesthesia. Pyruvate levels at 3 hr postovulation (2.6 mmol X kg-1 dry weight) were higher than 12 hr before ovulation or 12 to 72 hr after ovulation (1.6 to 2.2 mol X kg-1) in both ampulla and isthmus. Lactate levels were significantly increased at 12 to 24 hr in the isthmus (28 mmol X kg-1) compared to other times during the cycle (9-19 mmol X kg-1). The observed levels of these metabolites may reflect changes in oviductal metabolism, induced by the hormone pattern of the estrous cycle, that promote the availability of needed energy substrates for the early embryo.

Anaerobiosis↗