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Biomedical subjects

W J Murray

Publications and source records attributed to W J Murray.

At least 73 records · Page 4Linked to original sources
PubMed1980

Nitrous oxide availability.

Nitrous oxide (N2O) is marketed as an inhalation anesthetic and as a food ingredient (e.g., whipping cream propellant). In the human, inhalation has been associated with "highs," peripheral nerve damage, mitotic poisoning of bone marrow, psychosis, and mental impairment. Exposure to hypoxemic mixtures has resulted in death. The commercial N2O sources specifically studied were aerosol whipping cream containers (three brands) and 6.5-cm cylinders, or chargers (two brands). The gas content and N2O concentrations of these devices were measured. The aerosol cans, when not shaken, will dispense at least 3 liters of 87 to 90% N2O. Charger misuse may occur when they are substituted for identically designed carbon dioxide (CO2) chargers of a seltzer bottle; 4.3 to 5.0 liters of 93 to 98% N2O is expelled at a controllable rate. The toxicity of these inexpensive N2O products, their high potential for misuse, and the absence of labeling (chargers) argue that their distribution be discontinued.

Aerosols↗
PubMed1980

Acetylcarnitine and cholinergic receptors.

Acetylcarnitine, a naturally occurring compound found in high concentration in heart and skeletal muscle of vertebrates, bears structural resemblance to acetylcholine, and studies have shown that it has slight cholinergic properties. Acetylcarnitine was subjected to conformational analysis by extended Hückel theory (EHT) and complete neglect of differential overlap (CNDO/2) molecular orbital methods. The preferred conformations were examined with respect to their similarity to the Kier and Chothia-Pauling models of cholinergic receptor patterns. The preferred conformations of both isomers did not fit the receptor pattern described by Kier's model, although energy barriers to rotation are low enough to permit accommodation. The Chothia-Pauling model predicts activity for the S-isomer only. These studies partially explain the low cholinergic activity found for acetylcarnitine and the higher activity of (S)-acetylcarnitine compared to the R-isomer.

Acetylcarnitine↗
PubMed1980

A new look at pharmacy services in the operating suite and recovery room.

Drug control and charging traditionally have been delegated to overburdened physicians and nursing personnel in operating rooms, anesthesiology, and immediate postoperative patient care areas. Better drug control (e.g., charging, intravenous admixture preparation, and narcotic record keeping) in these areas is needed, and a 24-hour satellite pharmacy system is proposed. Revenue production and expense incurred were projected by analyzing drug usage. Responsive drug dispensing and control were evaluated by a 10-day pilot study during which the pharmacy provided the entire drug needs of the patient while in the operating suite. Economic analyses revealed significant "lost charges" by the automatic replacement system currently in use. Revenue was maintained while providing clearly labeled drugs in a ready-to-use form. Problems with drug inventory and narcotic control were lessened for the nursing and physician staffs during the pilot study. It was concluded that drug distribution and control via a decentralized pharmacy satellite located in the operating room area is a financially viable solution resulting in better patient care.

Accounts Payable and Receivable↗
PubMed1979

A model for thyroid hormone--receptor interactions.

Theoretical electronic structure calculations on the thyroid hormones and analogues, as well as model hormone--receptor interactions, have been carried out. These studies (a) support the concept that the 4'-OH group is a H-bond donor to the in vivo nuclear receptor and suggest that at the receptor this OH group is trans to the 3' (distal) substituent; (b) indicate that there is an important intramolecular interaction between 3' and 4' substituents, and those 3' substituents that most favor both 4' OH orientation trans to the 3' group and a more acidic OH group substantially increase binding and biological activity; and (c) support the concept that there is a direct correlation between the conformational free energy of the aromatic rings and biological activity.

Animals↗
PubMed1978

Potential anticoagulant drug interactions in ambulatory patients.

Computer-generated prescription drug purchase records for ambulatory patients receiving oral anticoagulants (OAC) were studied for concomitant use of other drugs which have been reported to induce clinically significant interactions. One third of 479 patients taking OAC were exposed to a potentially interacting drug at some time during this 6-month period. The percentage of patients with drug interaction exposure correlated directly with total drug use (p less than 0.0005). There were no significant differences when interaction exposure rates were compared in the cases of single : multiple pharmacy and single : multiple physician-patient groups. Warfarin was the most common anticoagulant (greater than 95%) and barbiturates the most common interacting drug.

Anticoagulants↗
PubMed1977

Molecular connectivity and steric parameters.

The possible relationship between molecular connectivity indexes, mchi, and Es, a thermodynamically derived parameter used to estimate steric effects in organic reactions and sometimes used in biological structure-activity relationships, was investigated. The extended chi terms, 2chi, 3chi, and 4chi, were correlated significantly to Es (r = 0.961). Aralkyl esters deviated from the correlations, possibly due to intramolecular interactions.

Chemical Phenomena↗
PubMed1977

Hemorrhagic shock.

The treatment of hemorrhagic shock is discussed, based on principles illustrated in a hypothetical case. The pathophysiology and clinical monitoring of hypovolemic shock are reviewed. A practical approach to volume replacement therapy in hemorrhagic shock is suggested.

Adolescent↗
PubMed1976

Molecular connectivity V: connectivity series concept applied to density.

The concept of the expanded series of the connectivity index, chi, is introduced and applied to a consideration of the density of three classes of molecules. Correlations are found using two terms in the expanded series. A preliminary reflection on the extended series terms is made. It is noted that the regression equation constant in the three studies is close to the phase volume, 0.7402, and the possible significance of this fact is discussed.

Alcohols↗
PubMed1976

Molecular connectivity. 6. Examination of the parabolic relationship between molecular connectivity and biological activity.

The topologically derived, nonempirical molecular connectivity index, chi, for several classes of compounds is shown to be parabolically related to the biological activities of these compounds. Similar nonlinear relationships were previously shown between the octanol-water partition coefficients, expressed as log P, of the compounds and their biological activities. These and previous studies indicate that many physiochemical properties presently used in structure-activity studies may be intermediaries between the nonempirical molecular structure encoded in chi and measured biological activities.

Amines↗
PubMed1975

Molecular connectivity. I: Relationship to nonspecific local anesthesia.

A very significant linear correlation was found between a recently proposed connectivity index and molecular polarizability, cavity surface areas calculated for water solubility of alcohols and hydrocarbons, and biological potencies of nonspecific local anesthetics. The simplicity of calculation of the index from the connectivity in the molecular skeleton, together with the very significant correlation, indicates its practical value.

Anesthetics, Local↗
PubMed1975

Molecular connectivity. II: Relationship to water solubility and boiling point.

The connectivity index, easily computed by arithmetic and based upon the degree of connectedness at each vertex in the molecular skeleton, is shown to give highly significant correlations with water solubility of branched, cyclic, and straight-chain alcohols and hydrocarbons as well as with boiling points of alcohols. These correlations are superior to those based on well-founded theory relating to solvent cavity surface area. An empirical modification to the connectivity index gave an improved correlation for both solubilities and boiling points.

Alcohols↗
PubMed1975

Molecular connectivity. III: Relationship to partition coefficients.

The molecular connectivity index is shown to be linearly related to the octanol-water partition coefficients of a variety of monofunctional chemical classes including esters, alcohol, ketones, ethers, carboxylic acids, amines, and hydrocarbons. A modification of the connectivity index, taking into account the valency or degree of unsaturation of an atom, merges the data for all compounds except hydrocarbons. The connectivity index is also shown to be useful for correlating biological activity. These studies indicate that partition coefficients represent empirical quantities having intermediate significance between biological data and the more fundamental property of molecular connectivity.

Chemical Phenomena↗