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Biomedical subjects

M J Murray

Publications and source records attributed to M J Murray.

At least 19 recordsLinked to original sources

A national survey on the practice patterns of anesthesiologist intensivists in the use of muscle relaxants.

OBJECTIVE: To determine the practice patterns of anesthesiologist intensivists (with the special certificate of competence in critical care medicine from the American Board of Anesthesiology) in the use of neuromuscular blocking drugs, in the ICU setting. DESIGN: A survey. PARTICIPANTS: All anesthesiologists with the special certificate of competence in critical care (n = 374) were selected for this study. Of the 339 who could be contacted and who were still actively practicing, 185 (55%) completed the survey. RESULTS: In the ICU setting, anesthesiologist intensivists most commonly used vecuronium (52%) administered by bolus injection, bolus injection followed by infusion, or by continuous infusion. The most frequent indication for muscle relaxation was facilitation of mechanical ventilation (89%). Neuromuscular blockade was most commonly monitored clinically (55%), with only 34% of respondents using a peripheral nerve stimulator. All respondents indicated the concomitant use of sedatives or narcotics with muscle relaxants. CONCLUSIONS: This study was created to address the dearth of information regarding actual usage of muscle relaxants in the ICU setting. The survey population was chosen as one with great familiarity in the use of muscle relaxants. The 55% response rate was significantly greater than the expected response rate for a single mailing survey. In the ICU setting, neuromuscular blocking drugs are most frequently used to facilitate mechanical ventilation. The prevalence of vecuronium use is of interest in light of recent case reports of prolonged neuromuscular blockade after long-term vecuronium administration. The low frequency of peripheral nerve stimulator monitoring during muscle relaxation may contribute, in part, to the problem of prolonged blockade after drug withdrawal. Muscle relaxants are not used in the absence of sedation and/or analgesia by this practitioner population.

Anesthesiology

A murine leukemia virus mutant with a temperature-sensitive defect in membrane glycoprotein synthesis.

Cells infected with a temperature-sensitive mutant (ts-26) of Rauscher murine leukemia virus (R-MuLV) or with wild-type virus were labeled with 35S-methionine, and cell extracts were examined for radioactive polypeptides which could be precipitated by monospecific antisera to viral proteins. When shifted from permissive (31 degrees C) to nonpermissive (39 degrees C) temperature, cells infected with ts-26 rapidly begin to accumulate gPr90enr, the glycoprotein precursor to the membrane envelope glycoprotein gp70 and to the membrane-associated protein p15E. Simultaneously, formation of these mature virion proteins ceases. In addition, lactoperoxidase-catalyzed surface labeling with 125I--iodine indicates that the plasma membrane of cells infected with ts-26 becomes depleted of gp70 antigens at 39 degrees C. Nevertheless, at 39 degrees C these cells release defective MuLVs which lack gp70 and p15E but contain an outer membrane. The released particles also contain an aberrantly processed form of the major virion core protein p30, and many of these virion cores have an unusual immature crescent shape. It has previously been reported that cells infected with the ts-26 mutant of R-MuLV process a 65,000 dalton precursor (Pr65gag) of the virion core proteins more slowly at 39 degrees C than do cells infected with wild-type virus (Stephenson, Tronick and Aaronson, 1975). Although we have confirmed these results, this effect is relatively small and it is known that various alterations of MuLV assembly can lead secondarily to inhibited processing of Pr65gag. We propose that the ts-26 mutant has a primary temperature-sensitive defect in membrane glycoprotein synthesis and that this change causes pleiotropic effects on core morphogenesis.

Genes

Anorexia of infection as a mechanism of host defense.

The role of anorexia of infection as a mechanism of host defense was studied by force-feeding infected mice to a normal energy intake. Their mortality and survival times were then compared with those of infected mice feeding ad libitum. Mortality was increased and survival time shortened in force fed animals. Our observations suggest that anorexia, by reducing energy intake, has a significant role in the early defense of the host.

Animals

Glycoprotein encoded by the Friend spleen focus-forming virus.

The Friend spleen focus-forming virus (F-SFFV) released from cultured erythroleukemia cells (cell line F4-6/K) was cloned free of its helper lymphatic leukemia virus (F-MuLV). After allowing adsorption to Sc-1 fibroblasts at a low multiplicity of infection, the cells were seeded individually into wells of a microtitier test plate and the resulting colonies were grown into large cultures. Among 14 of these cell cultures that have been analyzed thoroughly, 6 contained F-SFFV alone, 1 contained F-MuLV plus F-SFFV, and 7 were uninfected. Each of the Sc-1 cell lines which had been infected with cloned F-SFFV contained a glycoprotein with an apparent molecular weight of 55,000 (gp55) that was absent from the cell lines that lacked F-SFFV. gp55 was also present in Friend erythroleukemia cells and in fibroblasts infected with an F-SFFV that had been doubly cloned in another laboratory. These results indicate that gp55 is encoded by the F-SFFV genome. gp55 has the following additional properties. It can be immunoprecipitated with antiserum made to the F-MuLV virion envelope glycoprotein (gp75). Its unglycosylated polypeptide, formed in cells treated with 2-deoxy-D-glucose, has a molecular weight of approximately 45,000. Its tryptic peptide map contains peptides in common with F-MuLV gp75 but it also contains unique peptides. It appears to be absent or present in only low concentrations in erythroleukemia cell plasma membranes as determined by lactoperoxidase-catalyzed iodination, and it accumulates intracellularly in large amounts. In addition, it is absent from released virions. The majority of the cellular gp55 has an isoelectric point of 8.5 to 9.0. These results are consistent with the idea that an env gene recombination event was involved in the origin of F-SFFV.

Cell Line

The adverse effect of iron repletion on the course of certain infections.

The incidence of infections was studied in 137 iron-deficient Somali nomads, 67 of whom were treated with placebo and 71 with iron. Seven episodes of infection occurred in the placebo group and 36 in the group treated with iron; these 36 episodes included activation of pre-existing malaria, brucellosis, and tuberculosis. This difference suggested that host defence against these infections was better during iron deficiency than during iron repletion. Iron deficiency among Somali nomads may be part of an ecological compromise, permitting optimum co-survival of host and infecting agent.

Adolescent

Serum cholesterol, triglycerides and heart disease of nomadic and sedentary tribesmen consuming isoenergetic diets of high and low fat content.

1. The effects were examined of two approximately isoenergetic diets differing widely in saturated fat content on the levels of serum cholesterol and triglycerides of nomads and non-nomads in eastern Niger. Each person was also examined for clinical and electrocardiographic evidence of heart disease. 2. No significant differences could be found between serum cholesterol and triglyceride levels of 297 Anagamba nomad men consuming 73% energy as fat and 303 Kanouri sedentary men consuming 9% energy as fat. 3. Rheumatic heart disease was common in nomads and four possible cases of ischaemic heart disease were found in sedentary men only.

Adolescent

The effect of iron status of Nigerien mothers on that of their infants at birth and 6 months, and on the concentration of Fe in breast milk.

1. Within the limits of this study, neither maternal iron deficiency nor Fe-overload as measured at term appeared to affect the complement of Fe received by the foetus. 2. Infants feeding entirely on breast milk appeared to have normal Fe status 6 months postpartum regardless of the Fe status of the mother. 3. No relationship could be demonstrated between the Fe content of breast milk and the Fe status of the mother.

Anemia, Hypochromic

Diet and cerebral malaria: the effect of famine and refeeding.

In an outbreak of Plasmodium falciparum malaria following refeeding after famine cerebral malaria was restricted to children eating grain. Nomad children consuming a predominantly milk diet were free of this complication despite an equivalent incidence of uncomplicated malaria. Freedom of nomads from cerebral complications may be due to inhibition by the milk diet of rapid division of the parasite combined with delayed recovery after famine of T cell function.

Animals

The pharmaceutical industry: a further study in corporate power.

This article represents an updated version of previous research conducted on the United States pharmaceutical industry. The unstated purpose of this article is to present new findings which supplement the earlier research. This article describes three aspects of the United States pharmaceutical industry: its strategy and structure within the world market, its global expansion beyond the territorial boundaries of the United States, and its interlocking directorates with banking institutions. The thesis presented here is twofold: first, the United States pharmaceutical industry has become increasingly integrated into larger and more heterogeneous production units operating on the world market; and second, the United States pharmaceutical industry has become increasingly linked to large United States banking firms through interlocking directorates.

Drug Industry

Starvation suppression and refeeding activation of infection. An ecological necessity?

The hypothesis is advanced that starvation suppresses and refeeding activates certain infections as an essential part of an ecological balance between man, his animals, and his environment. During famine, then, man fails to thrive, but his ultimate extinction is prevented in part by the parallel decline in fecundity of his "micropredators". In times of plenty the parallel increase in the same predators is a check against his excessive multiplication.

Adult

Parotid enlargement, forehead edema, and suppression of malaria as nutritional consequences of ascariasis.

Bilateral painless enlargement of the parotids, a curiously localized edema of the forehead and relative freedom from malaria were striking findings in children of Anjouan but not of Grande Comore, two neighboring islands of the Comorro group in the Indian Ocean. Compared with those of Grande Comore, Anjouan children were heavily infested with Ascaris lumbricoides. We suggest that the clinical findings may be the nutritional consequence of severe ascariasis and that the low incidence of malaria in Anjouan children may be an example of the delicate ecological balance between the host, the Ascaris, and the plasmoidum.

Abdomen

Metal-polynucleotide interactions. A comparison of carcinogenic and non-carcinogenic metals in vitro.

The effects of divalent cations on mixing curves of synthetic polyribonucleotides in solution are described. Manganese and cadmium chlorides at 10(-3) M induce changes suggestive of base mispairing. MnCl2 induces mispairing in complexes formed between both poly(I) and poly(C,U) and poly(I) and poly(C,A) while CdCl2 affects base pairing between poly(I) and poly(C,U) only. By contrast, the chlorides of magnesium and zinc show no mispairing effects with either polymer pair. Manganese and cadmium are both reported carcinogens in animals while magnesium and zinc are not. The possibility that direct metal-nucleic acid interaction may be involved in metal carcinogenesis is discussed.

Binding Sites