Search PubMed⌕ Search

Biomedical subjects

M S Moore

Publications and source records attributed to M S Moore.

49 records · Page 3Linked to original sources

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↗

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↗

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↗

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↗

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↗

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↗

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↗

The effect of a wrist brace on injury patterns in experimentally produced distal radial fractures in a cadaveric model.

We compared patterns of bony and ligamentous injury with distal radial fractures in braced and unbraced wrists using 20 paired fresh cadaveric upper extremities. A commercially available wrist brace was placed on one wrist in each pair. Specimens were then placed in a fast-loading gravity-driven device and subjected to loads averaging 16 kg from an average height of 78 cm. Postfracture radiographs were obtained, the specimens were dissected, and fracture patterns and ligamentous integrity were assessed. The following fracture types were produced: distal radial fractures (eight unbraced, seven braced) and intraarticular (seven unbraced, four braced). Radiographically, seven unbraced wrists demonstrated carpal bone fracture and one braced wrist demonstrated carpal fractures. Eight unbraced and three braced wrists sustained carpal intrinsic ligament injuries, four unbraced and one braced wrists demonstrated extrinsic ligament injuries. More capsular tears occurred in the unbraced group (N = 8) than in the braced group (N = 1). This model demonstrated a difference in the patterns of injury in unbraced and braced wrists subjected to the same mechanical conditions, which suggests that use of a wrist brace may alter patterns of wrist injury.

Biomechanical Phenomena↗