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Biomedical subjects

S Williams

Publications and source records attributed to S Williams.

At least 739 records · Page 41Linked to original sources
PubMed1982

Dichotic lateral asymmetry: the effects of grammatical structure and telephone usage.

No confirmation could be obtained that the magnitude of the dichotic REA for speech is affected by whether the stimuli are syntactically structured. Recall-order was controlled in Experiment 1 by cueing one ear immediately after a dichotic stimulus; in Experiment 2 by cueing before a stimulus. The subject's reported ear preference for telephone usage was correlated with his ear difference in the first experiment but not in the second. Perhaps telephone usage causes an attentional bias (for speech) to one or other ear, more often to the right; which is over-ridden by the precued instruction to attend to a particular ear.

Cues↗
PubMed1982

The effects of lesions in telencephalic visual areas of pigeons on dimensional shifting.

Two experiments on dimensional shifting in pigeons with lesions of telencephalic visual areas are reported. In the first, pigeons were initially trained on a pattern discrimination with color irrelevant and then the color discrimination was made relevant and pattern irrelevant. Pigeons with ectostriatal lesions made more errors than shams or Wulst-lesioned animals on the pattern problem, but there was no difference among the three groups on the shift to color. In the second experiment, the same discriminations were studied in the reverse order: the animals first learned the color problem and then shifted to pattern. In this case the ectostriatal-lesioned animals showed a deficit on both problems. The Wulst-lesioned animals, on the other hand, showed a deficit on the shift to pattern but not on the original color problem. The results are discussed in terms of the nature of the deficits caused by the two lesions and their meaning for questions of comparative neurobiology.

Animals↗
PubMed1982

The importance of splenic blood flow in clearing pneumococcal organisms.

Overwhelming infection from encapsulated bacteria occurs after splenectomy. Decreases in IgM, tufsin, and serum opsonin are known to occur in animals and humans after splenectomy. A substantial immunologic advantage exists if some splenic tissue remains, but this may not offer sufficient protection from encapsulated bacteria if splenic arterial blood flow is reduced. This experiment was designed to examine the rate of pneumococcal clearance by the spleen and to determine the relationship between splenic blood flow and splenic tissue mass in bacterial clearance from the blood. Pneumococcal clearance, splenic blood flow, and residual splenic weight were measured in 171 rabbits with normal spleens, ligated splenic arteries, splenic autotransplants, hemisplenectomies, and splenectomies. Interruption of the splenic artery results in delayed pneumococcal clearance that is due to reduced blood flow and not to a decrease in splenic tissue mass. Splenic artery ligation to preserve an injured spleen cannot be assumed to give protection from sepsis.

Animals↗
PubMed1982

Indications for aortography in blunt thoracic trauma: a reassessment.

The indications for aortography in patients sustaining blunt chest trauma have increased as the number of radiographic and clinical findings associated with traumatic rupture of the thoracic aorta (TRA) proliferate. No studies, however, have demonstrated whether these findings are useful in selecting patients for aortography. In order to determine the predictive value of reported associations in TRA, the presence or absence of nine radiographic and nine clinical findings associated with TRA were tabulated and tested for correlation with the results of aortography in 173 consecutive patients who underwent arch aortography from 1975 to 1980 to rule out TRA following blunt trauma. Mediastinal widening was the most reliable indicator of TRA. All patients less than 65 years old with TRA presented with mediastinal widening. In patients under 65, the reliability of mediastinal widening to predict TRA was not enhanced by any other clinical or radiographic finding studied. On the other hand, only two of six TRA's in patients over 65 had mediastinal widening. Only in this group over 65 did other publicized indications for aortography, including pulmonary contusions or multiple rib fractures including ribs 1 and 2, have any association singly or in combination with TRA. We conclude that all trauma victims who have a widened mediastinum should undergo aortography. Other reported associations by themselves are not absolute indications for aortography except in patients 65 years old or older.

Adolescent↗
PubMed1981

Tetanus prophylaxis and accidental wounds.

Of 400 consecutive patients who had wounds treated in the Accident Department, 200 remembered receiving either booster injections or a full course of tetanus toxoid in the last 10 years. During this period, 182 patients received their initial toxoid injection in association with treatment of a wound in an accident department. Only 71 (38%) of these patients attended for a full course of injections. From our assessment of the wounds and the patient's anti-tetanus immunity, 79 patients (20%) were considered to be at risk of developing tetanus. By further considering the time interval elapsed between injury and treatment, a 'high risk' group of 13 patients (3%) was recognised. It is recommended that the use of human immunoglobulin should be reserved for the 'high risk' group, and that the remainder of the 'at-risk' patients should receive penicillin prophylaxis only.

Adolescent↗
PubMed1981

Effect of nonsteroidal anti-inflammatory drugs on the hypoxic rat heart.

The influence of the nonsteroidal anti-inflammatory drugs indomethacin (10 microgram/ml), mefenamic acid (10 ng/ml) and acetylsalicylic acid (50 microgram/ml) were investigated for their effects on hypoxically perfused rat hearts. Hypoxia-induced mechanical cardiodepression was attenuated to varying degrees by most drugs, although only mefenamic acid reduced the degree of bradycardia. All the agents reduced in some measure the rise in resting tension produced by hypoxic perfusion and enhanced the functional activity of the myocardium upon reoxygenation of hearts made hypoxic for 10 min only. The degree of contracture after reoxygenation was substantially attenuated by all three drugs. Although coronary flow decreased dramatically during prolonged hypoxia, this phenomenon was significantly prevented by the nonsteroidal anti-inflammatory drugs. Cellular Na content of hypoxic hearts treated with mefenamic acid was elevated, whereas no other significant electrolyte changes were observed. The presence of mefenamic acid results in a reduced extracellular space size, whereas cellular water content was increased by both mefenamic acid and acetylsalicylic acid. Calcium transport of isolated mitochondria from hypoxically or normoxically perfused hearts was not modified by any treatment. Indomethacin, acetylsalicylic acid and mefenamic acid all significantly inhibited prostaglandin release from the heart. These results suggest that various nonsteroidal anti-inflammatory drugs may offer some protective influence on hypoxic rat hearts particularly with respect to coronary artery patency during hypoxic perfusion.

Animals↗
PubMed1980

Birth complications and the distribution of handedness.

In an attempt to clarify the relationship between self-reported birth complications and handedness, the handedness distributions of 181 college students who reported birth complications and 1320 students who reported no complications were compared. The results suggest a clear but modest shift in the birth complications group away from the dextral end of the continuum. However these data did not validate the hypothesis that left-handedness results from birth complications.

Adolescent↗