PubMed Health⌕ Search

Biomedical subjects

M S Moore

Publications and source records attributed to M S Moore.

17 recordsLinked to original sources
PubMed1992

The two steps of nuclear import, targeting to the nuclear envelope and translocation through the nuclear pore, require different cytosolic factors.

We have isolated two cytosolic fractions from Xenopus oocytes that contain all of the activity necessary to support both steps of nuclear import in digitonin-permeabilized mammalian cells: binding at the nuclear envelope and translocation through the nuclear pore. The first cytosolic fraction (fraction A) interacts with an import-competent, but not a mutant, nuclear localization sequence-bearing conjugate and stimulates its accumulation at the nuclear envelope in an ATP-independent fashion. The second cytosolic fraction (fraction B) gives no discernible effect when added alone; but when added either together with fraction A, or after fraction A, stimulates the passage of the conjugate from the outer nuclear envelope to the interior of the nucleus in an ATP-dependent fashion.

Amino Acid Sequence↗
PubMed1991

Helping patients travel by air.

Although safe and rapid, air travel may present problems for people with certain medical conditions. Most medical emergencies that occur during a flight are preventable by judicious screening and preparation. We provide guidelines for physicians who are consulted about the wisdom of undertaking a journey by air. Potential stresses before, during and after the flight are outlined, including decreased atmospheric pressure, low humidity, turbulence, inactivity and time changes. We recommend precautionary measures for passengers with certain medical conditions, such as recent myocardial infarction, pulmonary disorders, pneumothorax, cerebrovascular accidents and diabetes and for those who have recently had surgery. The policy regarding air travel for pregnant women varies with each airline, but for certain conditions associated with pregnancy supplemental oxygen should be ordered before the trip. The special equipment and care that most airlines offer to ill or disabled people are described.

Aircraft↗
PubMed1991

Reconstitution of clathrin-coated pit budding from plasma membranes.

Receptor-mediated endocytosis begins with the binding of ligand to receptors in clathrin-coated pits followed by the budding of the pits away from the membrane. We have successfully reconstituted this sequence in vitro. Highly purified plasma membranes labeled with gold were obtained by incubating cells in the presence of anti-LDL receptor IgG-gold at 4 degrees C, attaching the labeled cells to a poly-L-lysine-coated substratum at 4 degrees C and then gently sonicating them to remove everything except the adherent membrane. Initially the gold label was clustered over flat, clathrin-coated pits. After these membranes were warmed to 37 degrees C for 5-10 min in the presence of buffer that contained cytosol extract, Ca2+, and ATP, the coated pits rounded up and budded from the membrane, leaving behind a membrane that was devoid of LDL gold. Simultaneous with the loss of the ligand, the clathrin triskelion and the AP-2 subunits of the coated pit were also lost. These results suggest that the budding of a coated pit to form a coated vesicle occurs in two steps: (a) the spontaneous rounding of the flat lattice into a highly invaginated coated pit at 37 degrees C; (b) the ATP, 150 microM Ca2+, and cytosolic factors(s) dependent fusion of the adjoining membrane segments at the neck of the invaginated pit.

Adenine Nucleotides↗
PubMed1989

Coat proteins isolated from clathrin coated vesicles can assemble into coated pits.

Isolated human fibroblast plasma membranes that were attached by their extracellular surface to a solid substratum contained numerous clathrin coated pits that could be removed with a high pH buffer (Moore, M.S., D.T. Mahaffey, F.M. Brodsky, and R.G.W. Anderson. 1987. Science [Wash. DC]. 236:558-563). When these membranes were incubated with coat proteins extracted from purified bovine coated vesicles, new coated pits formed that were indistinguishable from native coated pits. Assembly was dependent on the concentration of coat protein with half maximal assembly occurring at 7 micrograms/ml. Assembly was only slightly affected by the presence of divalent cations. Whereas normal appearing lattices formed in a low ionic strength buffer, when assembly was carried out in a low pH buffer, few coated pits were evident but numerous small clathrin cages decorated the membrane. Coated pits did not form randomly on the surface; instead, they assembled at differentiated regions of membrane that could be distinguished in carbon/platinum replicas of frozen and etched membranes by the presence of numerous particles clustered into patches the size and shape of a coated pit.

Cell Membrane↗
PubMed1989

Towards an in vitro system for studying clathrin-coated pit function.

To elucidate the molecular basis of coated pit function, we are developing a method for reconstituting the endocytic cycle in a cell-free system. Using purified membranes attached to a solid substratum, we have successfully reconstituted coated pit assembly. We now show that the endogenous coated pits on these membranes spontaneously round up and leave the membrane at 37 degrees C. As measured by radioimmunoassay, clathrin loss is both pH- and temperature-dependent. The loss is also inhibited by pretreating the membranes with apyrase at 37 degrees C, which suggests that nucleotide triphosphates are required.

Cell Line, Transformed↗
PubMed1987

Assembly of clathrin-coated pits onto purified plasma membranes.

During receptor-mediated endocytosis, coated pits invaginate to form coated vesicles, clathrin and associated proteins dissociate from the vesicle membrane, and these proteins form new coated pits at the cell surface. As a means of elucidating molecular mechanisms that govern the function of coated pits, the assembly phase of this cycle was reconstituted by incubating purified membranes that were treated to remove endogenous coated pits with cytoplasm extracted from cultured cells. The in vitro assembly of coated pits on these membranes satisfactorily mimics many features of coated pit formation in the intact cell. These studies indicate that: the membranes contain a limited number of coated pit assembly sites that bind clathrin with high affinity; the half-time for assembly is 5 minutes both at 4 degrees C and 37 degrees C; during assembly, proteins with molecular sizes of 180, 110, and 36 kilodaltons are recruited to the plasma membrane; and assembly is not dependent on adenosine triphosphate, but this nucleotide triggers a temperature-dependent loss of coated pits that are assembled in the absence of adenosine triphosphate.

Adenosine Triphosphate↗
PubMed1984

Rapid micromeasurement of lactate in whole blood.

A new lactate sensor makes it possible to measure the lactate content of whole blood directly in less than 1 min, using only a 10-microL blood sample. The procedure works equally well with plasma, serum, spinal fluid, other body fluids, or tissue homogenates. The instrument is calibrated with lactate standards between 0 and 15 mMol/L. The sensor, a polarographic enzyme electrode, gives a current which is a linear function of the lactate concentration. There is no interference from glucose, pyruvate, alcohol, ascorbate, anticoagulants, lidocaine, acetaminophen, or other drugs and metabolites commonly encountered in critically ill patients. The lactate sensor is composed of a peroxide sensor and an enzyme transducer membrane. The lactate is stoichiometrically converted to pyruvate and hydrogen peroxide by lactate oxygen oxidoreductase derived from Pediococcus species. The oxygen required for the enzymatic oxidation is supplied via an air-permeable silicone elastomeric membrane used for stirring. Comparison of our new electroenzymatic method with the Boehringer-Mannheim photoenzymatic method gives correlations of 0.997 for both whole blood and plasma.

Alcohol Oxidoreductases↗
PubMed1978

A technique for investigating the intensity and duration of human psychomotor impairment after intravenous diazepam.

The objective of this study was to evaluate the impairment of both psychomotor function and memory after intravenous administration of 17 to 28 mg. of diazepam to normal volunteers. A battery of tests, including word memory, Seguin form board, digit symbol, digit span, block design, and reaction time, was administered at set intervals to both drug and nondrug subjects. The diazepam group demonstrated both psychomotor and anterograde memory deficits which persisted throughout the 150-minute evaluation; but relative to the control group, the diazepam group had enhanced retrograde memory. These preliminary results indicate that even after subjects appear to be recovered from the effect;s of diazepam, residual psychomotor and memory impairment remain.

Adult↗
PubMed1978

Acute and chronic effects of cocaine on extinction-induced aggression.

Pigeons worked individually in a chamber containing a response key and a mirror. Pecking on the key was controlled by a multiple schedule in which a brief period of continuous food reinforcement alternated with a 5-minute period of extinction. Under baseline conditions, aggressive behavior (responding on the mirror) occurred at the onset of each extinction period. In Experiment I (acute drug administration), the aggressive behavior was decreased by doses of cocaine that had little or no effect on key pecking. Such food-reinforced responding was disrupted, however, by higher doses of cocaine. An attempt to mimic the disruptive drugs effects by a prefeeding manipulation was unsuccessful. In Experiment II (chronic drug administration), some tolerance developed to the disruptive effects of cocaine on the food-reinforced responding, except at the highest dose tested. There was no clear-cut indication of tolerance to the initial effect of cocaine on the aggressive behavior at any dose.

Aggression↗
PubMed1977

Complexities of human factors in aviation.

Statistics continue to show an increased incidence of serious aircraft accidents where the cause has been attributed to "human factors", although the factors themselves have not always been specifically determined. This paper is an attempt to outline some of the stress factors which may cause a pilot to react improperly in a given situation and thus set in motion a train of events potentially leading to an accident.

Accidents, Aviation↗
PubMed1976

Extinction-induced mirror responding as a baseline for studying drug effects on aggression.

Pigeons worked individually in a chamber containing a response key and a mirror. Responding on the key was controlled by a multiple schedule in which a brief period of continuous food reinforcement alternated with a 5 min period of extinction. Under baseline conditions, aggressive behavior (responding on the mirror) occurred at the onset of each extinction period. After 10 saline control sessions, 5 mg/kg of chlordiazepoxide was injected IM 30 min presession for 60 daily sessions. The drug initially produced a marked decrease in aggressive behavior but had little or no effect on key pecking. The aggressive behavior generally remained suppressed during the chronic drug regimen and returned to control levels when the drug was withdrawn. It was concluded that the technique of extinction-induced mirror responding in pigeons provides a stable, sensitive and recoverable baseline for objectively assessing selective drug effects on aggression.

Aggression↗
PubMed1975

Some myths about "mental illness".

Radical psychiatrists and others assert that mental illness is a myth. The opening and closing portions of the article deal with the impact such an argument has had in law and psychiatry. The body of the article discusses the five following versions of the myth argument prevalent in radical psychiatry: (1) that there is no such thing as mental illness; (2) that those called "mentally ill" are really as rational as everyone else, only with different aims, that the only reasons anyone ever thought differently was (3) because of unsophisticated category mistakes or (4) because of an adherence to the epistemology of a sick society; and (5) that the phrase "mental illness" is used to mask value judgments about others' behavior in pseudoscientific respectability. Reasons are given for rejecting each of these versions of the argument that mental illness is a myth.

Forensic Psychiatry↗