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Biomedical subjects

M Cook

Publications and source records attributed to M Cook.

At least 127 records · Page 7Linked to original sources

Fear-relevant selective associations and covariation bias.

Three experiments used an illusory correlation paradigm to assess the effects of fear on the perception of the covariation between fear-relevant stimuli and shock. In Experiment 1, high- and low-fear women were exposed to 72 trials during each of which a fear-relevant (snake or spider) or fear-irrelevant (mushroom and flower) slide was followed by a shock, a tone, or nothing. Although the relation between slide types and outcomes was random, high-fear subjects markedly overestimated the contingency between feared slides and shock. Experiment 2 showed that this bias was due to the aversive, rather than more generally salient, features of shock. Low-fear subjects demonstrated biases equivalent to those of high-fear subjects only when the base rate of shock was increased from 33% to 50% in Experiment 3. It is concluded that fear may be linked to biases that serve to confirm fear. The relevance of the present findings to preparedness theory is also discussed.

Association↗

Observational conditioning of fear to fear-relevant versus fear-irrelevant stimuli in rhesus monkeys.

Two experiments examined whether superior observational conditioning of fear occurs in observer rhesus monkeys that watch model monkeys exhibit an intense fear of fear-relevant, as compared with fear-irrelevant, stimuli. In both experiments, videotapes of model monkeys behaving fearfully were spliced so that it appeared that the models were reacting fearfully either to fear-relevant stimuli (toy snakes or a toy crocodile), or to fear-irrelevant stimuli (flowers or a toy rabbit). Observer groups watched one of four kinds of videotapes for 12 sessions. Results indicated that observers acquired a fear of fear-relevant stimuli (toy snakes and toy crocodile), but not of fear-irrelevant stimuli (flowers and toy rabbit). Implications of the present results for the preparedness theory of phobias are discussed.

Animals↗

Guillain-Barré syndrome and related conditions in Victorian teaching hospitals 1980-84.

Cases of Guillain-Barré syndrome, its variants, and chronic inflammatory demyelinating neuropathy presenting during the period 1980-84 were identified through computer-based record systems. Case notes were examined, and cases that did not meet standard criteria for diagnosis were excluded. A hundred and ten patients were identified, giving an annual adult incidence rate of 0.9/100,000 and a male:female ratio of 1.3:1. The majority of cases developed severe tetraparesis, but unusual presentations included the Miller-Fisher variant, paraplegia, and bibrachial involvement. There was wide variation in peak disability, ranging from ambulant with weakness (32%), through bedfast but without significant respiratory involvement (29%), to respiratory involvement requiring admission to an intensive care unit (38%). Of those discharged directly home, the average hospital stay for those less than 50 years was 27 days, whilst that for those over 50 was 49 days. CSF protein was measured in 87 patients, and was greater than or equal to 0.6 g/L in 76% of these. Nerve conduction studies were performed in 52 patients, and were abnormal in 90% of these. Guillain-Barré syndrome and allied conditions represent a major drain on health resources, and the need to provide adequate plasmapheresis facilities for patients early in the course of severe disease is stressed.

Adolescent↗

Lead absorption in indoor firing range users.

To determine if users of indoor firing ranges may be at risk from lead exposure, we studied a law enforcement trainee class during three months of firearms instruction. Blood lead levels were obtained before training and at four-week intervals during training. Air lead levels were measured three times during instruction. Blood lead levels rose from a pre-training mean of 0.31 mumol/L to 2.47 mumol/L. Mean air lead levels were above 2,000 micrograms/m3, more than 40 times the Occupational Safety and Health Administration's standard of 50 micrograms/m3. Cumulative exposure to lead and the change in blood lead were positively correlated. Control measures need to be studied to determine their efficacy in decreasing or eliminating this health risk.

Air Pollutants↗

Possible case of hyperparathyroidism in a Roman period skeleton from the Dakhleh Oasis, Egypt, diagnosed using bone histomorphometry.

A histomorphometric study of thin femoral head sections of a skeletal sample from the Dakhleh Oasis, Egypt, dated from circa 36 B.C. to 400 A.D., identified an adult female (Dk31-A1) in her mid-50s with a high percentage resorption surface with tunneling resorption as is typically found in hyperparathyroidism. Five static histomorphometric bone parameters were measured with the following results for this individual: 1) mean wall thickness, 41.94 micron, 2) trabecular bone volume, 18.54%, 3) surface volume, 4,070 mm2/cm3, 4) mean trabecular diameter, 132 microns, and 5) total resorption surface, 12.31%. The overall histomorphometric features and differential diagnosis support the diagnosis of hyperparathyroidism. We conclude that histomorphometry of dried bone, particularly in this case where preservation is ideal, is a valuable investigative technique for paleopathology.

Bone and Bones↗

Role of genetic variation at the fibrinogen locus in determination of plasma fibrinogen concentrations.

Three restriction fragment length polymorphisms (RFLPs) of the fibrinogen genes were used in 91 individuals to investigate the role of genetic variation at this locus in the determination of plasma fibrinogen. The strongest association was with a polymorphism detected with the beta-fibrinogen probe and the enzyme BclI. The probe detects two alleles, designated B1 and B2. The individuals with the genotype B1B1 had a mean fibrinogen of 2.74 g/l; those with B2B2 had a mean fibrinogen of 3.69 g/l (a level previously associated with a strongly increased risk of ischaemic heart disease); and those heterozygous for the two alleles, with the genotype B1B2, had a mean of 2.98 g/l. Genetic variation at the fibrinogen gene locus accounted for 15% of the total phenotypic variance in fibrinogen.

Female↗

Lead exposure in a firing range.

We report lead exposure in four employees of a privately owned shooting range, one of whom had neurological toxicity due to lead. Increasing time worked at the range was associated with elevation of blood lead. This incident emphasizes the risk of airborne lead exposure to employees of firing ranges.

Air Pollutants, Occupational↗

Traumatic rupture of the thoracic aorta. A review of 49 cases.

We examined retrospectively the chest radiograph of forty nine patients with angiographically proven aortic ruptures. The plain film findings found most consistently were a wide mediastinum (69.5%), partial obliteration of the descending aorta (67.3%), left apical cap (65.3%), downward displacement of the left main bronchus (65.3%), tracheal deviation to the right (63.2%), obscuration of the aortic arch (55.1%), right paratracheal stripe thickening (53%) and nasogastric tube deviation to the right (50%). We also examined 113 sequential aortograms performed after thoracic trauma over 3 years, to determine the positive rate in our series; 14 studies were positive for a rate of 12.4%. No single case of proved ruptured aorta with a normal chest radiograph was detected.

Aorta, Thoracic↗

There are two gene sequences for human apolipoprotein CI (apo CI) on chromosome 19, one of which is 4 kb from the gene for apo E.

A cDNA probe corresponding to the mRNA sequence for apolipoprotein E (apo E) was used to screen two independently-constructed human genomic libraries. Two recombinants (lambda E-2, and lambda E2-1), isolated using the apo E cDNA probe, also contain part or all of the apo CI gene. Hybridisation studies using both apo E and apo CI cDNA probes show that these two genes are in the same orientation and separated by 4 kb.

Apolipoprotein C-I↗

Attribute processing in patients with graphical copying disability.

This study investigated whether defective copying of multiple-line figures in lesion patients is associated with a deficit in perceptually processing and copying elementary attributes. Lesion and Control patients were assessed on a copying test comprising multi-line figures, and on parallel perceptual and motor forms of single-attribute tasks for Size, Orientation, Angle, Position and Direction. Copying test performance was correlated with perceptual attribute performance for the Lesion but not the Control group. Mean attribute performance of the Lesion patients who showed a copying disability (defined as a copying performance below the minimum performance of the Control group) was inferior to that of the non-disabled and Control subjects. The non-disabled patients did not differ from the Controls on any of these tasks. Performance in the copying test for left- and right-hemisphere patients did not differ, but left-hemisphere patients showed less impairment in the simple attribute tasks. The results are discussed in terms of the role of elementary perceptual deficits in copying disability and hemispheric differences in the nature of this condition.

Adolescent↗