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Biomedical subjects

J N Tsanakas

Publications and source records attributed to J N Tsanakas.

9 recordsLinked to original sources
PubMed2002

A critique on the concept of "brain death".

Since the concept of "brain death" was introduced in medical terminology, enough evidence has come to light to show that the concept is based on an unclear and incoherent theory. The "brain death" concept suffers by internal inconsistencies in both the tests-criterion and the criterion-definition relationships. It is also evident that there are residual vegetative functions in "brain dead" patients. Since the content of consciousness is inaccessible in these patients who are in a profound coma, the diagnosis of "brain death" is based on an unproved hypothesis. A critical evaluation of the role and the limitations of the confirmatory tests in the diagnosis of "brain death" is attempted. Finally it is pointed out that a holistic approach to the problem of "brain death" in humans should necessarily include the inspection of the content of consciousness.

Brain↗
PubMed1988

Free running asthma screening test.

The free running asthma screening test (FRAST) was evaluated in 503 Sheffield schoolchildren aged 6 to 12 years and compared with responses to an asthma questionnaire. The FRAST measured peak expiratory flow rate (PEFR) before and at 1, 5, and 10 minutes after maximum voluntary running for at least 5 minutes in a standardised environment. A fall in PEFR of greater than 15% in at least two postexercise readings was defined as abnormal. Six (1%) children did not do the test and 69 (14%) failed to complete it. Of these, 14 were known asthmatics, 18 were not testable, and 37 were normal when retested. There were 14 abnormal FRAST results among 412 'normal' children who completed the test and 10 of these were subsequently diagnosed asthmatic. None of 14 children with an abnormal FRAST result had been identified as wheezy, chesty, or asthmatic in the questionnaire. In this sample there was, on average, one child in every school class with unrecognised exercise induced bronchospasm. The FRAST is an acceptable, feasible, and cost effective way of identifying such potential asthmatics at school.

Asthma↗
PubMed1987

Evaluation of nebulisers for bronchial challenge tests.

The reproducibility of the output of seven different nebulisers was tested. Nebulisers with a minimal increase in output at higher flow rates had less variability in the output. The selection of a nebuliser for bronchial provocation tests depends on the intranebuliser variability. Two nebulisers had highly reproducible outputs.

Bronchial Provocation Tests↗
PubMed1987

Reduced vital capacity in insulin-dependent diabetes.

Spirometry was performed on 88 children with insulin-dependent diabetes mellitus (IDDM) and 216 healthy controls living in Sheffield. Children with IDDM had significantly lower percentage predicted forced vital capacity (FVC) than did control children or reference norms. There was no evidence that the reduced FVC was confined to a subgroup of children, and there was no correlation with duration of IDDM or glycemic control. A longitudinal study of 27 children with IDDM did not show progressive deterioration in percentage predicted FVC with age. These findings suggest that a tendency toward reduced lung volumes exists in IDDM and may not be a direct result of the metabolic disturbances in the disease.

Adolescent↗
PubMed1984

Factors affecting the peak expiratory flow rate in children.

Standing height and peak expiratory flow rate (PEFR) were measured in 339 British schoolchildren aged 7-16 years. Enquiry was made into a past history of wheeze or atopy, a family history of asthma or atopy, or a cold within the preceding 2 weeks. A strong correlation was found between PEFR and height, expressed by the equation PEFR = 5.640 Ht - 472.5 (r = 0.89). Neither a recent cold nor a positive personal or family history of wheeze or atopy had any significant effect on the regression equation. Sex was also unimportant. Further examination of the data revealed that age had an effect on peak expiratory flow rate independent of height. The effect of age was linear in girls and curvilinear in boys. Five hundred and sixty-nine Greek schoolchildren were also studied and similar age effects were found on the regression of peak expiratory flow rate on height. The implication of these findings is that any population study of peak expiratory flow rates in children should ensure a normal age distribution at each height interval. Significant error in the prediction of the PEFR will result if the effect of age is ignored, particularly in pubertal boys.

Adolescent↗
PubMed1983

Unexpectedly high peak expiratory flow rates in normal Greek children.

Peak expiratory flow rate (PEFR) and standing height (Ht) were measured in 522 healthy Greek children aged 7-16 years. The regression equation of PEFR on height in centimetres was PEFR = 5.34 Ht--380.8. This demonstrated markedly higher values for PEFR in Greek children compared to previously published data from other countries. A sample of 339 British children was examined similarly. The regression equation of PEFR on height in centimetres was PEFR = 5.64 Ht--472.5. This was similar to previously published data. No cause for this discrepancy was found after close examination of population sampling, measurement error or calibration error in the Greek study. It is therefore concluded that Greek children appear to have an unexpectedly high PEFR for height.

Adolescent↗