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Biomedical subjects

R D Miller

Publications and source records attributed to R D Miller.

At least 325 records · Page 18Linked to original sources
PubMed1980

Pyridostigmine kinetics with and without renal function.

Pyridostigmine kinetics were examined under conditions of clinical use as an antagonist of nondepolarizing neuromuscular blockade in anesthetized patients with and without renal function. Pyridostigmine serum levels were assayed by gas-liquid chromatography, and data were fitted to a 2-compartment kinetic model. Pyridostigmine kinetics following renal transplantation (n = 5) were not different from those in patients with normal renal function. Renal function (n = 5) elimination half-life increased from 112 +/- 12 min (mean +/- SD) to 379 +/- 162 min, and serum clearance decreased from 9 +/- 2 ml/kg/min to 2 +/- 0.6 ml/kg/min in anephric patients (n = 4). We conclude that renal function accounts for 75% of pyridostigmine clearance.

Adult↗
PubMed1980

Comparison of the cardiovascular actions of ORG NC 45 with those produced by other non-depolarizing neuromuscular blocking agents in experimental animals.

The cardiovascular actions of 1- [(2 beta,3 alpha, 16 beta,17 beta)-3,17-bis(acetyloxy)-2-(1-piperidinyl)-androstan-16-yl]-1-methyl-piperidinium bromide (Org NC 45) are reviewed and compared with those of other non-depolarizing neuromuscular blocking drugs. Results obtained in anaesthetized cats and dogs have demonstrated that, in contrast to other neuromuscular blocking drugs, Org NC 45, even in doses 20 times greater than those required for neuromuscular block, has no effects on heart rate, arterial pressure, autonomic ganglia, adrenoceptors or baroreceptors activity. Studies in pithed rats and on guineapig atria have further shown that Org NC 45 has little effect on cardiac muscarinic receptors or on noradrenaline re-uptake mechanisms. These results suggest that Org NC 45 possesses significant advantages over presently used non-depolarizing neuromuscular blocking drugs, since its clinical use should not be associated with cardiovascular side-effects.

Anesthesia, General↗
PubMed1980

ORG NC 45.

Explore the source record for details and available documents.

Humans↗
PubMed1980

A comparison of inpatients with primary unipolar depression and depression secondary to anxiety.

Retrospective comparisons between primary unipolar depression and depression secondary to anxiety in 65 inpatients revealed a number of differences. Secondary depression was associated with a significantly higher incidence of neurotic traits in childhood, chronic unhappiness, and unsupportive family. Tricyclic antidepressants and ECT were both more effective in primary depression, and some secondary depressives became worse on ECt. When primary depression was sub-divided into familial, nonfamilial and spectrum types, the greatest differences were noted between familial and secondary depressions. In the former group a more stable life style was noted. Secondary and spectrum types differed on only two variables and several similarities were noted. Platelet monoamine oxidase activity was significantly higher in secondary depression.

Adult↗
PubMed1980

Nonfatal maxillocerebral mucormycosis with orbital involvement in a dehydrated infant.

Mucormycosis in infants is exceedingly rare, and over 90% of reported cases have been fatal. A case of a dehydrated three-week-old infant with involvement of the palate, maxilla, orbit, and brain is described with extensive laboratory and radiological investigation. This infant survived after surgical debridement and therapy with amphotericin B.

Amphotericin B↗
PubMed1980

Cardiovascular and neuromuscular effects of Org NC 45, pancuronium, metocurine, and d-tubocurarine in dogs.

We compared the cardiovascular and neuromuscular effects of Org NC 45 with those of pancuronium, metocurine, and d-tubocurarine in six dogs anesthetized with halothane. The ED90 (dose of drug which produced a 90% depression of twitch tension) of Org NC 45, pancuronium, metocurine, and d-tubocurarine was 14 +/- 3, 22 +/- 3, 63 +/- 19, and 130 +/- 19 micrograms/kg, respectively. All subsequent neuromuscular and cardiovascular effects were determined from a dose equal to 3 times the ED90 of muscle relaxant. Org NC 45, pancuronium, metocurine, and d-tubocurarine produced a neuromuscular blockade with a during (time from relaxant administration until recovery 50% of the original twitch tension) of 42 +/- 2, 108 +/- 10, 109 +/- 21, and 100 +/- 19 minutes, respectively. Org NC 45 caused no significant cardiovascular changes. Pancuronium increased heart rate, mean arterial blood pressure, cardiac output, and pulmonary wedge pressure, and it decreased systemic vascular resistance (p less than 0.05). Although metocurine also increased heart rate and cardiac output (p less than 0.05), mean arterial blood pressure and pulmonary wedge pressure did not change. d-Tubocurarine decreased all cardiovascular parameters except heart rate which increased significantly (p less than 0.05). We conclude that Org NC 45 produces a neuromuscular blockade of shorter duration with fewer cardiovascular changes than that of pancuronium, metocurine, or d-tubocurarine.

Animals↗
PubMed1980

Antagonism of Org NC 45 neuromuscular blockade by neostigmine, pyridostigmine, and 4-aminopyridine.

The antagonism of Org NC 45 neuromuscular blockade by neostigmine, pyridostigmine, 4-aminopyridine, and their combinations was studied in the in vivo rat sciatic nerve anterior tibialis preparation using the constant infusion of Org NC 45 technique. The ED50 (dose of drug which produced a 50% antagonism) of neostigmine, pyridostigmine, and 4-aminopyridine were 14.5, 75, and 466 micrograms/kg, respectively. The addition of 100 microgram/kg of 4-aminopyridine, which produced no antagonism by itself, decreased neostigmine ED50 to 9.8 micrograms/kg. The addition of 200 micrograms/kg of 4-aminopyridine, which produced a 14.8% antagonism by itself, decreased the ED50 of pyridostigmine to 17.5 micrograms/kg. We concluded that neostigmine, pyridostigmine, and 4-aminopyridine effectively antagonize an Org NC 45 neuromuscular blockade. Neostigmine and pyridostigmine interact with 4-aminopyridine in a synergistic manner. The doses of antagonists were very similar to those required to antagonize a pancuronium neuromuscular blockade.

Aminopyridines↗
PubMed1980

Voluntary "involuntary" commitment--the briar-patch syndrome.

Szasz and others have pointed out that many so-called voluntary admissions to mental hospitals have various elements of coercion involved, and are thus not truly voluntary. The author contends that the converse situation is also true, that many patients admitted under involuntary commitment papers arrange for their own commitments. Reasons for such choices are discussed in the context of a review of the literature and several case histories.

Adult↗
PubMed1980

Serum concentrations of C3 and C4 of the complement system in patients with chronic obstructive pulmonary disease.

In a search for host factors for the complex multifactoral disease, chronic obstructive pulmonary disease, we compared some major components of the complement system in 111 subjects with forced expiratory volumes in 1 sec less than 70% of predicted (index subjects) to those in 111 subjects matched as pairs for age, sex, smoking, and occupation having forced expiratory volumes in 1 sec more than 85% of predicted normal. Significantly lower blood levels of C3 and C4 were found in the index subjects (p less than 0.001). Among the index subjects there was a significant correlation between chronic cough and expectoration and low C3 and C4. There was not a significant correlation between low values and the frequency and severity of past respiratory infections. Levels of serum B globulin fraction, in which C3 and C4 migrate, were not different between the index and control subjects.

Complement C3↗
PubMed1980

Cystic disease of the lungs in tuberous sclerosis: clinicopathologic correlation, including body plethysmographic lung function tests.

Cystic disease of the lungs with focal nodular adenomatoid proliferation is among the least common pathologic stigmas of tuberous sclerosis. It tends to develop in adult life, occurs more commonly among female patients who do not have mental retardation and epileptic seizures, and may be rapidly fatal after the onset of respiratory symptoms. Reported here is one such case, that of a 45-year-old woman who had, in addition to the pulmonary involvement, cerebral tubers, retinal phakomas, adenoma sebaceum, subungual fibromas, renal angiomyolipomas, cardiac angiofibroma, hepatic angiomas, and thyroid adenoma. This is also the first patient in whom pulmonary function tests by body plethysmography were performed, which aids our understanding of the pathophysiology of respiratory failure in tuberous sclerosis.

Cysts↗
PubMed1980

Roentgenologic determination of total lung capacity.

Geometric analysis of the chest roentgenogram allows calculation of estimated gas volume. If roentgenograms are made on individual patients or in epidemiologic studies in which relatively expensive nitrogen meters or body plethysmographs are not available, the thoracic roentgenogram provides an economical alternative. This study compares two roentgenographic methods of estimating total lung capacity in 154 subjects who also had total lung capacity estimated by the 7-minute nitrogen-washout technique or by total-body plethysmography. Results with the roentgenographic techniques were closely comparable with each other and with those of the gas-dilution and total-body plethysmograph methods in normal subjects. The planimetric method consistently estimated higher total lung capacity than the elliptic method in men and women with total lung capacity of 7.75 liters or less. In patients with severe obstructive lung disease, the roentgenographic methods were more closely comparable with body plethysmography, which is believed to be the most accurate, whereas the nitrogen-rinsing and similar gas-dilutional methods tended to underestimate the true volumes. The roentgenographic techniques also proved to be reliable in a small group of patients with varying degrees of pulmonary fibrosis.

Female↗
PubMed1979

Simultaneous modeling of pharmacokinetics and pharmacodynamics: application to d-tubocurarine.

We propose a model of drug pharmacodynamic response that when integrated with a pharmacokinetic model allows characterization of the temporal aspects of pharmacodynamics as well as the time-independent sensitivity component. The total model can accommodate extremes of effect. It allows fitting of simultaneous plasma concentration (Cp) and effect data from the initial distribution phase of drug administration, or from any non-equilibrium phase. The model postulates a hypothetical effect compartment, the dynamics of which are adjusted to reflect the temporal dynamics of drug effect. The effect compartment is modeled as an additional compartment linked to the plasma compartment by a first-order process, but whose exponential does not enter into the pharmacokinetic solution for the mass of drug in the body. The hypothetical amount of drug in the effect compartment is then related to the observed effect by the Hill equation, a nonlinear sigmoid form. Nonlinear least-squares data fitting is used for parameter estimation. The model is demonstrated on two different sets of Cp and effect data for the drug d-tubocurarine (dTC). In 7 normal subjects, the (mean +/- SD) rate constant for equilibration of dTC effect (paralysis) and Cp is 0.13 +/- 0.04 min-1 and the (mean +/- SD) steady-state Cp required to produce 50% paralysis is 0.37 +/- 0.05 microgram/ml.

Adult↗