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Biomedical subjects

T E Anderson

Publications and source records attributed to T E Anderson.

At least 37 records · Page 2Linked to original sources
PubMed1988

Short-term energy balance: relationship with protein, carbohydrate, and fat balances.

Energy balance (energy intake-energy expenditure) is known to vary considerably on a day-to-day basis in free-living individuals. The extent to which stores of protein, carbohydrate, and fat are used to store short-term surpluses of energy and the extent to which these stores are used to make up temporary energy deficits are incompletely known. We have measured body energy balance as well as carbohydrate, fat, and protein balances in 27 Caucasian men and 27 Caucasian women over a 24-h period in a respiratory chamber. An estimated weight-maintenance diet was fed to each subject. Because of individual differences in family background, body composition, activity, and the failure of some subjects to eat all of their food, these estimates are not exact, and energy balance is rarely achieved. Energy balance was correlated with fat balance in men (r = 0.79, P less than 0.0001) and women (r = 0.72, P less than 0.0001), and the slope of this relationship was not distinguishable from unity in men (1.16 +/- 0.18) or women (0.80 +/- 0.15). There were no correlations between energy balance and either carbohydrate or protein balances. This study demonstrates that carbohydrate and protein stores are closely regulated by adjusting oxidation to intake. Thus fat, rather than carbohydrate or protein, is almost exclusively used or stored in response to day-to-day fluctuations in energy balance.

Adult↗
PubMed1987

Physician-staffed helicopter scene response from a rural trauma center.

One hundred ten consecutive trauma patients transported directly from the scene of injury by a hospital-based helicopter emergency medical service were reviewed. These patients were injured in the rural areas of central and northeastern Pennsylvania and were transported to a level I trauma center. The medical flight team consisted of an emergency physician and a registered nurse. The average round-trip flight distance was 44 miles. The overall mortality was 21.8%. Eighty-eight percent of the injuries were motor vehicle related. Only two patients received advanced life support prior to arrival of the helicopter. Forty-five percent of patients required major intervention by the medical flight team at the scene. The average scene time was 33.6 minutes for transported patients. Sixteen patients required extrication after the arrival of the flight crew and had significantly prolonged scene times averaging 61.8 minutes (P less than .001). Patient entrapment was the most important contributing factor in on-scene ground time.

Aircraft↗
PubMed1986

Rural interhospital helicopter transport of motor vehicle trauma victims: causes for delays and recommendations.

One hundred twenty-six consecutive ACS Category I motor vehicle trauma patients transported by helicopter from 25 hospitals to a regional trauma center in rural Pennsylvania during a 14-month period were reviewed retrospectively. The overall mortality was 13%. Average round-trip distance was 79 miles. Interventions by the medical flight team (emergency physician/nurse) included endotracheal intubation, tube thoracostomy, and/or central venous access in 42 patients (33%) prior to lift-off. Ground time at the referring facility, from landing to lift-off, when no interventions were required of the flight team, averaged 31.2 minutes (baseline). Ground time when major therapeutic interventions were required (principally airway management), however, averaged 57.4 minutes, an 84% increase over baseline (P less than .01). A major cause of the excessive ground times was the lack of standardized diagnostic workup and stabilization of patients prior to arrival of the flight team. Recommendations for standardized emergency department preparation of trauma victims requiring aeromedical evacuation are made.

Accidents, Traffic↗
PubMed1986

Effects of acute alcohol intoxication on spinal cord vascular injury.

Previous experimental studies found that acute intoxication may alter the long-term outcome of standardized spinal cord injury resulting in increased spinal cord necrosis and impaired functional recovery. We examined the effects of acute intoxication (blood alcohol concentration of 100 mg/dl) on hemorrhage and axonal conduction three hours after moderate severity spinal cord contusion induced by a constrained stroke pneumatic impactor. The hemorrhagic spinal cord lesion resulting from standardized injury was significantly increased by acute intoxication. Both local hemorrhage at the injury site and rostro-caudal and total extent of hemorrhage were increased. Also, the ability of nerve axons to recover function during the first three hours post-contusion was impaired by intoxication. These findings confirm that increased post-contusion hemorrhage results when spinal cord contusion injury occurs in the presence of acute intoxication, and suggest that increased intramedullary hemorrhage may contribute to previously observed increases in anatomic damage and impaired functional recovery with alcohol intoxication.

Alcoholic Intoxication↗
PubMed1986

Determinants of 24-hour energy expenditure in man. Methods and results using a respiratory chamber.

Daily human energy requirements calculated from separate components of energy expenditure are inaccurate and usually in poor agreement with measured energy intakes. Measurement of energy expenditure over periods of 24 h or longer is needed to determine more accurately rates of daily energy expenditure in humans. We provide a detailed description of a human respiratory chamber and methods used to determine rates of energy expenditure over 24-h periods in 177 subjects. The results show that: fat-free mass (FFM) as estimated by densitometry is the best available determinant of 24-h energy expenditures (24EE) and explains 81% of the variance observed between individuals (24EE [kcal/d] = 597 + 26.5 FFM); 24EE in an individual is very reproducible (coefficient of variation = 2.4%); and even when adjusted for differences in FFM, there is still considerable interperson variability of the daily energy expenditure. A large portion of the variability of 24EE among individuals, independent of differences in body size, was due to variability in the degree of spontaneous physical activity, i.e., "fidgeting," which accounted for 100-800 kcal/d in these subjects.

Activities of Daily Living↗
PubMed1986

Compression of rat spinal cord in vitro: effects of ethanol on recovery of axonal conduction.

The effect of ethanol on recovery of neural conduction after spinal cord compression was evaluated in an isolated rat spinal cord preparation. Controlled compression of 50 to 75 percent of the cord cross-section was delivered using a piezoelectric translator. Postcompression compound action potential (CAP) amplitude, latency, and refractory periods were measured relative to pre-compression values. Recovery of CAP's was compared for spinal cords exposed to ethanol in vitro (100 mg/dl bath concentration, started one hour prior to compression) versus those maintained in normal artificial CSF. The in vitro effects of ethanol were evaluated on spinal cords from rats maintained on a normal diet and from those repeatedly intoxicated with ethanol for 15 days prior to the acute experiment. Compression of the cord resulted in an immediate 68% decrease in CAP peak amplitude and an increase in latency (171%) and refractory period (256%). In normal bathing medium, CAP amplitude recovered to 83% of pre-compression values 180 minutes after compression. The addition of ethanol to the artificial CSF did not directly affect CAP parameters, but combined with compression, CAP amplitude recovered to only 42% of pre-compression values 180 minutes after impact (p less than .01). Recovery was less affected by acute ethanol exposure in cords from ethanol pretreated animals. CAP amplitude recovered to 83% of pre-compression levels and was not different from compression-only recovery (p less than 0.10). The data suggest that direct effects of ethanol on axonal membranes may affect the sensitivity of axons to mechanical trauma or their capacity to recover normal function. Since spinal cords from repeatedly exposed animals are less sensitive to the acute effects of ethanol, ethanol may be acting to "fluidize" the axonal membrane.

Alcoholic Intoxication↗
PubMed1985

Spinal cord contusion injury: experimental dissociation of hemorrhagic necrosis and subacute loss of axonal conduction.

Previously reported experimental models for spinal cord contusion injury do not allow the independent control of compression and contact velocity required for interpretation of experimental data relating kinematics of vertebral injury to spinal cord injury. Therefore, controlled dynamic compression of the spinal cord was used to study compression and contact velocity as independent variables. Cord conduction was assessed using the latency of somatosensory evoked potentials in response to hindlimb stimulation. The latency increase at 4 hours after contusion differed significantly between control and 50% compression results, and between 25% and 50% compression results. A small nonsignificant increase in latency was observed with increase in contact velocity. The extent of hemorrhagic necrosis correlated with contact velocity rather than with the amount of compression. This study demonstrates, for the first time, a dissociation between hemorrhagic necrosis and loss of neuronal conduction in the subacute phase. Although long-term effects of hemorrhagic necrosis on cord structure and conduction remain to be evaluated, the data suggest that delayed loss of neuronal conduction seen clinically may result from moderate levels of cord compression at high contact velocity. Such an injury is not reproducible by weight-drop techniques for cord injury.

Animals↗
PubMed1984

Shoulder injuries in the athlete.

Most shoulder injuries in the athlete can be managed nonoperatively; prior to any management, however, they require careful evaluation for accurate diagnosis. Once the diagnosis has been made, few of these injuries will actually require surgery and most will obtain an excellent result with full return to function. Several specific shoulder injuries are discussed and their treatment is outlined.

Acromioclavicular Joint↗
PubMed1983

Bur buttercup poisoning of sheep.

Bur buttercup (Ceratocephalus testiculatus) has not been considered to be poisonous, but the sudden death loss of 150 ewes while grazing it prompted study of the plant. It was found that bur buttercup can be highly toxic to sheep, with a lethal dose being as little as 500 g of green plant for a 45-kg sheep. Clinical signs of bur buttercup poisoning are weakness, depression, diarrhea, labored breathing, anorexia, and occasional fever. Postmortem findings include inflammation and edema of the rumen; hemorrhage in the left ventricle of the heart; congestion of the lungs, liver, and kidneys; and excessive fluid in the thoracic and abdominal cavities.

Animals↗
PubMed1982

A controlled pneumatic technique for experimental spinal cord contusion.

The 'Allen technique', a weight-drop procedure introduced in 1911, remains the most widely used technique for experimental spinal cord contusion. Control of injury severity in this procedure is achieved by alteration of the height from which the standardized weight (usually 20 g) is dropped. It has not been possible in this technique to independently vary the amount of cord compression and the initial velocity of compression, since both are related to drop-weight kinetic energy. Our approach uses a constrained stroke pneumatic impactor to afford independent control of these two parameters. Mechanical testing of the device has verified the accuracy and repeatability of impact velocity and cord compression. More importantly, a pilot series at 2 m/s contact velocity with a range of compression has demonstrated neurophysiologically distinct levels of spinal cord injury as a function of compression. This includes a 'moderate' functional injury with impaired and delayed neuronal conduction through the injury site. Such a 'moderate' injury, at the threshold between recovery and permanent cord dysfunction, is particularly promising for the study of mechanisms underlying progressive post-contusion pathology; 'moderate' injury has not been reproducibly generated in weight-drop techniques.

Animals↗
PubMed1981

Pathogenetic aspects of hepatitis A virus infection in enterally inoculated marmosets.

Experimental hepatitis A virus (HAV) infection was studied in marmosets after enteral (intragastric) inoculation with special reference to the primary sites of HAV replication and immunopathology of the disease. The experiment was carried out using 28 Saguinus mystax negative for antibody to HAV (anti-HAV) and with statistically uniform baseline values of serum isocitrate dehydrogenase (SICD) activity. Each animal was infected with 1 ml of a 15% w/v stool suspension that was derived from marmosets infected with the third or fourth passage of the MS-1 strain of HAV. The incubation period measured by the first significant SICD elevation was 32 days in 11 of 13 marmosets. The animals were sacrificed 2, 4, 7, 11, 14, 18, 23, 28, and 32 days after inoculation and 1, 4, 8, 14, 21, 28, and 35 days after SICD elevation. HAV antigen, immunoglobulins, complement, and fibrin were identified in the liver, eight segments of the gastrointestinal tract, lymphoid system, and kidneys. HAV antigen was found only in the cytoplasm of hepatocytes and in gallbladder bile. These findings indicated that the liver was the sole and primary site of virus replication. Combined immunomorphologic and histopathologic observations also revealed that HAV antigen localization was associated with the sites of hepatocellular damage. There was no immunomorphologic evidence for humoral immune clearance of HAV antigen in the liver, lymphoid system, or kidneys.

Animals↗
PubMed1981

Malignant hyperthermia in myelomeningocele: a previously unreported association.

Malignant Hyperthermia is a life-threatening crisis frequently triggered by the use of various anesthetic agents. The syndrome of susceptibility has been observed in association with a number of orthopedic conditions seen in children but not with myelomeningocele. We have recently seen three children in our Spina Bifida Clinic with the syndrome and we wish to add myelomeningocele to the list of conditions that have a possible association to malignant hyperthermia.

Child, Preschool↗
PubMed1979

Inhibition in penicillin-induced epileptic foci.

A previous study indicated that the early surface negative component (associated with recurrent inhibition) of the evoked potential recorded from cat pericruciate cortex, subsequent to pyramidal tract stimulation, was altered after application of penicillin to the cortical surface (Van Duijn et al. 1973). This suggested that decreased effectiveness of recurrent inhibition might be the basis for epileptogenicity of penicillin. To verify that recurrent inhibition is functionally decreased in the penicillin epileptic focus and to assess alternative sites for penicillin action, this phenomenon was investigated at the cellular level. Neurons were recorded extracellularly and response to stimuli monitored throughout the transition from normal cortex to epileptogenic cortex. Stimuli employed were peduncular stimulation (to test recurrent inhibitory pathways), epicortical stimulation (to test inhibitory pathways, bypassing the recurrent collateral system), and forepaw footpad shock (to test the responsiveness ofneurons to afferent input). In normal cortex, PT cells were inhibited by peduncular or epicortical stimulation and excited by forepaw stimulation, with the excitation followed by a period of inhibition. In the penicillin focus, inhibition was not observed in response to any of the 3 stimuli, and the excitatory response to forepaw stimulation was maintained. The bursting non-PT cells, most likely candidates for interneurons, exhibited excitation in response to peduncular and epicortical stimulation, consistent with involvement in inhibitory pathways. Nonetheless, in the penicillin focus, excitatory response to peduncular and epicortical stimulation was maintained. Excitatory response to forepaw stimulation was also maintained in the penicillin focus. The results demonstrate a loss of effectiveness of recurrent inhibition measured at the PT cell body in the penicillin focus. Further, the reduction in inhibitory feedback occurs in conjunction with maintained or enhanced excitability of the neurons which are most likely candidates for inhibitory interneurons. Thus, penicillin is most likely exerting its effect at the inhibitory synapses onto PT cells in the cortex, thereby allowing excitatory input to have greater influence on neuronal firing.

Animals↗
PubMed1973

Influence of temperature and humidity on microbial, enzymatic, and physical changes of stored, pickling cucumbers.

Pickling cucumbers stored at five temperatures and four relative humidities were examined for growth of eight microbial groups, the activities of two enzyme systems (pectinolytic and cellulolytic), and weight loss. Twenty-four storage tests for 6 days each were conducted during the 2-year study. In general, microbial populations of the eight groups increased rapidly at the higher temperature (>21 C) and humidity (>70%) treatments. Moisture loss of the cucumbers was rapid with combinations of high temperatures and low humidities. The results suggest that the best environmental conditions for storage or transport of cucumbers would be a combination of low temperature (10 C) with high relative humidity (about 95%). These conditions minimized undesirable microbial, enzymatic, and physical changes of stored, pickling cucumbers.

Bacteria↗