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Biomedical subjects

J Brennan

Publications and source records attributed to J Brennan.

At least 127 records · Page 7Linked to original sources
PubMed1984

Relationship between the per cent of marrow cells in S phase and the outcome of remission-induction therapy for acute nonlymphocytic leukaemia.

The relationship between the pretherapy cell cycle characteristics of leukaemic marrow cells and the outcome of remission-induction therapy for acute nonlymphocytic leukaemia was studied in newly diagnosed and relapsed patients who were then treated with either combination chemotherapy consisting of cytosine arabinoside/anthracycline antibiotic +/- 6 thioguanine or with single agent high-dose cytosine arabinoside therapy. The outcome of high-dose cytosine arabinoside therapy was highly dependent upon the per cent of pretherapy cells in S phase with no remissions occurring in patients in whom the 3H-TdR labelling index was less than 6%. In contrast, the outcome of cytosine arabinoside/anthracycline antibiotic therapy was independent of the pretherapy cell cycle characteristics of the leukaemic cells.

Acute Disease↗
PubMed1983

Spontaneous aorto-caval fistulae.

The clinical and radiological presentation of four cases of spontaneous aorto-caval fistula is described. This is an unusual complication of an abdominal aortic aneurysm and presents with abdominal pain, a pulsatile abdominal mass and an abdominal bruit. Our cases illustrate the variable clinical presentation, outline the diagnostic difficulties and confirm the value of aortography. A possible role for the radiologist using a balloon catheter to close the fistula prior to surgery is suggested.

Aged↗
PubMed1982

Nonnutritive sucking during tube feedings: effects on preterm neonates in an intensive care unit.

Preterm neonates (mean 32 weeks' gestation, 1,300 gm birth weight) were provided a pacifier for nonnutritive sucking during tube feedings in the intensive care nursery. Their clinical course, subsequent bottle feeding behavior, and performance on the Brazelton Neonatal Behavior Assessment scale were compared with those of control group infants. The infants provided with pacifiers averaged 27 fewer tube feedings, started bottle feeding three days earlier, averaged a greater weight gain per day, and were discharged eight days earlier for an average hospital cost savings of approximately $3,500. Formula intake was similar for the two groups, although nurses appeared to provide more feeding stimulation for the control infants. On the Brazelton scale, the infants provided with pacifiers showed weak reflexes more frequently. Increased restfulness and diminished activity level in these infants may have contributed to the appearance of weak reflexes. The consistency between these findings and those of previous investigators suggests that the provision of a pacifier for nonnutritive sucking during tube feedings may be a cost-effective form of intervention.

Body Weight↗
PubMed1982

Stimulus control of instrumental reflexes in dogs: a comparison of alimentary and avoidance behaviors after prefrontal damage.

Two experiments involving parallel procedures to investigate stimulus generalization in prefrontal dogs under alimentary and defensive reinforcement were compared. Twelve dogs in the alimentary study were trained on a 50 percent partial reinforcement schedule, and 24 dogs were trained to avoid shock with either continuous shock availability and response contingent CS termination or with only 50 percent partial shock availability and response independent CS termination. One third of the subjects received bilateral medial prefrontal lesions, 12 dogs were given bilateral lesions of the lateral prefrontal cortex and the remaining subjects served as nonoperated controls. Generalization along the frequency dimension of the tonal CS was assessed during a sampling procedure within normal acquisition training, during complete extinction and following differentiation training. The results indicate specific effects from both the quality and the contingency of reinforcement. Within the limits of each reinforcement treatment, a dissociation occurred such that medial subjects tended to show heightened sensitivity to reinforcement density, while lateral subjects showed characteristic elevated reactivity during all generalization tests.

Animals↗
PubMed1981

Diagnosis of internal jugular vein thrombosis by computed tomography.

Internal jugular vein thrombosis was diagnosed by computed tomography in three cases. In all cases, selective catheterization of the internal jugular vein was avoided. Rapid intravenous infusion of contrast material was made to obtain prolonged blood iodine levels, allowing sufficient time to scan the neck adequately.

Adult↗
PubMed1981

Differentiation learning and auditory generalization in normal and prefrontal dogs after extensive avoidance training.

The continuation of a study of 24 dogs in the stages of avoidance reacquisition, differentiation training and generalization testing is reported. Subjects had previously received avoidance training with either response contingent CS termination on all trials or on only 50 percent of the training trials, prior to the administration of medial or lateral prefrontal lesions in 16 subjects. The remaining 8 subjects served as nonoperated controls. Following the appropriate surgical treatment, subjects were tested twice for generalization along the tonal frequency dimension of the avoidance CS. Trials to reacquisition criterion were comparable among all dogs, and subjects trained earlier with continuous response contingent CS termination had overlall faster response latencies, except for the medial subject that were slower than subjects trained under the partial schedule. Differentiation performance tended to show more success in the group given the earlier continuous response contingent avoidance training, although data from both training groups were variable. Subjects trained with the partial schedule had more extra- and intertial responses, which are considered as a byproduct of residual fear. Systematic effects from the surgical treatments were not found during differentiation training. Stimulus control by tonal frequency was more pronounced in subjects that had received the partial training schedule, and frequency generalization was disrupted by the lesion effects. The data are considered in light of reinforcement determinates from CS prolongation in the modification of defensive reflex control.

Animals↗
PubMed1979

Radioimmunoassay of carcinoembryonic antigen (CEA) without extraction and dialysis using solid-phase antibody.

A modified radioimmunoassay has been developed for plasma CEA levels. This procedure used immobilized, solid-state antibodies, does not require perchloric acid extraction of the plasma samples and purification of the extract by dialysis. The accuracy, sensitivity and precision are equal to those of the most widely used procedure and the laboratory effort is greatly reduced.

Carcinoembryonic Antigen↗
PubMed1979

Auditory frequency generalization in normal and prefrontal dogs trained in varieties of active avoidance reflexes.

Twelve dogs were trained to avoid shock with response contingent termination of a 1000 Hz tonal CS on all trials, whereas 12 additional dogs received the same training except that on 50 percent trials there was a fixed CS duration and no shock. Initial acquisition revealed that CS prolongation resulted in longer response latencies compared to subjects trained with response contingent CS termination. Both training groups were then assigned to subgroups (n=4) that received either lateral or medial lesions of the prefrontal cortex or a rest pause of 10 days. Postsurgical reacquisition indicated a medial deficit in response latencies for both training groups whereas performance levels of normal and lateral groups were comparable. Two generalization tests to tones of 600-, 800-, 1000-, 1200-, and 1400-Hz followed. During the sampled test only one block of the five test frequencies occurred with the regular 15 training trials, while the tonal frequencies were presented on all 20 daily extinction trials during massed generalization testing. No evidence of extinction was observed during the sampled generalization test in either training group. However, during massed testing, all subjects trained with response contingent CS termination showed an overall extinction influence, which was most pronounced in the medial subgroup, although the laterals showed frequency control as well. In the group trained with CS prolongation the controls had clear, discriminative performance, while little stimulus control or extinction influence were found in the medial or lateral subgroups. Comparison with alimentary data indicated much broader tonal frequency generalization in dogs trained in avoidance. However, when the procedures reduced avoidance levels, double dissociation of medial and lateral lesion effects on stimulus control and susceptibility to extinction emerged.

Acoustic Stimulation↗
PubMed1978

The relationship between uric acid and potassium in normal subjects.

The serum uric acid concentration in normal healthy subjects has been studied in relation to sex, height, weight, lean body mass measured from total body potassium and predicted from the Hume-Weyers formula (1971), total body potassium, plasma potassium and urea, and packed cell volume. The strongest correlation was found with sex, but height, weight, total body potassium, lean body mass (measured and predicted) also correlated significantly with serum uric acid concentration. However, when the sex variable was removed, the other factors lost their significant correlation. Finally, total red blood cell and plasma volumes were predicted (Hume and Goldberg, 1964) and from these an estimate of total plasma uric acid, total plasma potassium, and total red blood cell potassium obtained. Measured total body potassium was found to correlate well with total plasma potassium and total red blood cell potassium independent of sex. Total plasma uric acid correlated well with measured total body potassium when both sexes were considered and when separated into male and female groups the males retained a significant correlation as did the female group.

Adolescent↗
PubMed1976

Auditory frequency generalization with differing extinction influences in normal and prefrontal dogs trained in instrumental alimentary reflexes.

Following criterion of 90 percent correct responses to a 1,000-Hz tone on a 50 percent reinforcement schedule, 8 of 12 dogs were subjected to lesions of the medial or lateral prefrontal cortex. Three types of auditory frequency generalization tests followed separated by a period of reacquisition of the instrumental response. A sampling procedure of generalization assessment, wherein a block of test trials was contained within 15 partially reinforced trials and repeated over 16 days, revealed complete generalization in the medials and rapid, but discriminative responding in the laterals. The second generalization test was conducted in complete extinction over 5 days. The medials yielded discriminative performance and least overall resistance to extinction, while the laterals showed a higher amount of frequency control and minimal extinction effects. Go-no go differentiation training preceeded the last generalization test [CS(+) = 1,000 Hz; CS(-) = 600 Hz], resulting in retarded acquisition in the laterals and easiest acquisition in the medials. The last generalization test suggested that all groups were comparable, with some trend toward more rapid extinction in the medial dogs. Collectively, the data indicated that performance was determined by the interacting functions between the specific lesions and the density of reinforcement present in the testing procedure.

Animals↗
PubMed1975

Goal-striving discrepancy stress in urban Filipino men: II. Housing.

As part of a larger investigation of social/psychological stress and psychiatric adaptation in urban Manila, efforts were made to study the effects of goal-striving discrepancy stress in housing among Filipino men from different age groups and social classes. Goal-striving discrepancy stress is an organismic state characterized by tension and discomfort due to discrepancies between aspirations and achievements. Several studies have demononstrated that goal-striving discrepancy stress are asociated with psychiatric disorder. The present study focused upon the discrepancies between aspiration and achievements in housing among Filipino men. Housing constitutes one of man's basic problems in urban societies; however, in spite of the fact that housing is related to psychiatric adaptation, relatively few studies have been made of this problem. It is important to recognize that housing has numerous psychological implications for an individual. It is a symbol of social status and social acceptance and greatly influences an individual's view of himself and others. Some investigators have even suggested that housing may be construed as a symbolic representation of the mother-child relationship. For the present investigation, twelve housing characteristics considered to be important to Filipinos e. g., size, cost, location, ownership of land, etc., were derived and ninety-six Filipino males from different age groups and social classes were asked to indicate both their aspiration and their actual achievement for each of the twelve housing characteristics. Goal-striving discrepancies were obtained by subtracting the aspirational endorsements from the achievement endorsements. The discrepancy scores were then correlated with various psychiatric symptom patterns through factor analysis. Results of the investigation revealed profound social class differences in the amount of goal-striving discrepancy stress. ......

Achievement↗