Search PubMed⌕ Search

Biomedical subjects

A Thomas

Publications and source records attributed to A Thomas.

At least 487 records · Page 27Linked to original sources
PubMed1985

The laryngeal mask airway. Development and preliminary trials of a new type of airway.

A new form of airway has recently been described, which is introduced blindly into the hypopharynx to form a seal around the larynx, so permitting spontaneous or positive pressure ventilation without penetration of the larynx or oesophagus. The further development of this new airway is described and the results of 18 months' clinical experience are presented. The airway was used successfully in 118 patients, 17 of whom received controlled ventilation of their lungs. It was used in place of the facemask in routine anaesthesia, and was of particular value in ophthalmic, dental and ear, nose and throat procedures and where difficulties with the airway were expected. The incidence of sore throat and other problems was low. Experience of more than 500 cases suggests that the laryngeal mask airway may have a valuable rôle to play in all types of inhalational anaesthesia, while its proven value in some cases of difficult intubation indicates that it may contribute significantly to the safety of general anaesthesia.

Humans↗
PubMed1985

Long-term review of ring total hip arthroplasty.

In a five- to 12-year follow-up survey of 179 sequential cementless Ring metal-on-metal total hip arthroplasties, 55 (31%) of the patients were found to have died as a result of nonorthopedic conditions. Analysis of the records demonstrated that 20% of these patients had had poor results attributable to pain. Of the remaining 124 patients, 116 (94%) attended for full clinical and radiologic review yielding a total of 154 hips. Using Ring's classification, 75 hips were judged to have excellent or good results. Forty-one hips were graded as fair or poor as a result of pain, and an additional 15 hips were revised for symptomatic loosening. There were five cases of Brooker Grade IV periarticular ossification, four cases of gross metal reaction requiring prosthetic removal, and two cases of infection. There was considerable variation in the radiographic appearance of the hips, and at times radiographic changes were inconsistent with clinical symptoms. Eleven of the revised hips were converted to longer and larger-diameter uncemented Ring femoral components. Nine of these yielded only fair or poor results at the time of review, whereas both cases in which the femoral component was cemented were associated with good results.

Adult↗
PubMed1984

Unmyelinated axons in the pyramidal tract of the cat.

Ultrastructural preparations revealed the presence of unmyelinated axons in the pyramidal tract (PT) of the adult cat. At the level of the medulla oblongata, unmyelinated axons constituted 8-15% of the total PT population. Axon diameters ranged from 0.05 to 0.06 micron with a mean of 0.18 micron. Although axons were distributed throughout the PT, their density was highest in the medial part.

Animals↗
PubMed1984

Thrombosis and acute coronary-artery lesions in sudden cardiac ischemic death.

The nature of the pathologic lesion in sudden cardiac ischemic death is in dispute. Among 100 subjects who died of ischemic heart disease in less than six hours, coronary thrombi were found in 74. There was no difference in incidence between those who died in less than 15 minutes, those who died in 15 to 60 minutes, and those who died after one hour. Among 26 cases without an intraluminal thrombus, plaque fissuring was found in 21; thus, in only 5 cases was no acute arterial lesion demonstrated. No intraluminal thrombi were found in age-matched controls. Forty-eight of the 74 thrombi were found at sites of preexisting high-grade stenosis; 14 were found at points of previous stenosis of less than 50 per cent of the diameter of the lumen. Forty-seven per cent of the thrombi were found in the right coronary artery. Only 30 per cent were found in the left anterior descending coronary artery. The pathologic process in sudden ischemic death involves a rapidly evolving coronary-artery lesion in which plaque fissuring and resultant thrombus formation are present. These findings have implications for the prevention of sudden cardiac death by antithrombotic therapy.

Aged↗
PubMed1984

A molecular model for conjugational recombination in Escherichia coli K12.

Conjugational recombination in Escherichia coli was investigated by measuring lacZ+ product, beta-galactosidase, in crosses between lacZ mutants. Enzyme production in both Hfr and F-prime crosses was detected very soon after transfer of the donor lacZ allele. The level of enzyme activity was reduced by no more than two-fold when the recipient carried a recB mutation. With an F-prime donor, recombination appeared to be restricted largely to a short period immediately after transfer, with little evidence of recombination during subsequent exponential growth of the transconjugant cells. These observations are interpreted to suggest that recA dependent recombination is able to initiate with high efficiency at gaps present in the donor DNA before synthesis of a complementary strand is completed, and independently of recB function. A molecular model for conjugational recombination based on this idea is presented in terms of the known activities of recA and recBC products. Some of the predictions of the model are tested by analysing the recombinant genotypes produced in Hfr crosses with multiply marked strains.

Bacterial Proteins↗
PubMed1984

Opportunistic infections in homosexual men.

In summary, we have described a homosexual patient who died of Kaposi's sarcoma and overwhelming disseminated opportunistic infections. Review of the literature attests to the severe alterations of immune surveillance inherent in the homosexual population as a whole and the need for vigorous clinical investigation when warranted.

Candidiasis↗
PubMed1984

Clinical performance of the implantable cardioverter-defibrillator.

The automatic implantable cardioverter-defibrillator has been implanted in 276 patients with ventricular tachyarrhythmias refractory to therapy with a follow-up period up to 50 months (average 9.75 months). The functional performance of the device has so far been most encouraging. The risks and complications associated with its use are acceptable and quite similar to those observed in patients with implanted pacemakers. Acceleration of ventricular tachycardia to a faster rhythm or to ventricular fibrillation is dealt with successfully through recycling. Actuarial analysis indicates that the device has a significant impact on the survival rate of the implantees, reducing the one-year mortality rate attributed to arrhythmias to only 2%.

Actuarial Analysis↗
PubMed1984

Genesis and evolution of behavioral disorders: from infancy to early adult life.

The New York Longitudinal Study has followed the behavioral development of 133 subjects from early infancy to early adult life. Special attention has been given to the systematic clinical evaluation and follow-up of all subjects presenting any evidence of behavior disorder. The authors present incidence and outcome data, define the concept of temperament, and briefly discuss conceptual issues and empirical findings. They found the "goodness of fit" (consonance between the individual and the environment) concept useful in tracing developmental sequences. The authors summarize quantitative analyses identifying significant group correlations between antecedent variables and early adult outcome and suggest a tentative classification of the idiosyncratic factors also evident in the clinical course of individual subjects, with case illustrations.

Adaptation, Psychological↗
PubMed1984

Evaluation of intravitreal 5-fluorouracil, vincristine, VP 16, doxorubicin, and thiotepa in primate eyes.

A single intravitreal dose of 750 micrograms 5 fluorouracil (5 FU) or 5 micrograms doxorubicin were nontoxic to primate eyes. A concentration of 250 micrograms/ml of 5 FU in the vitrectomy infusion fluid in combination with 8 micrograms/ml of thiotepa, with 40 micrograms/ml of VP16 (etoposide), or with either .04 or .02 microgram/ml of vincristine was also well tolerated by the primate eye. 5 micrograms/ml of doxorubicin in the vitrectomy infusion fluid did not cause apparent toxicity to the retina. Toxic effects were noted in eyes receiving 250 micrograms of 5 FU in combination with either .15 or .1 microgram/ml of vincristine.

Animals↗
PubMed1984

Characterisation of glycoproteins in the sweat of the horse (Equus caballus).

The two major polypeptides H (Mr 49,000) and L (Mr 33,000) of equine sweat have been purified by gel filtration and characterised by gel electrophoresis and compositional analysis. Both H and L are glycoproteins containing sialic acid, neutral sugars, N-acetylglucosamine and N-acetylgalactosamine, but the two polypeptides differ considerably in the extent of glycosylation. H and L also differ in amino acid composition, but both contain only low levels of sulphur containing amino acids and histidine. These glycoproteins may behave as surfactants.

Amino Acids↗
PubMed1983

On the nature of the RecBC and RecF pathways of conjugal recombination in Escherichia coli.

The molecular mechanisms of the RecBC and RecF pathways for genetic recombination in E. coli were investigated by studying the kinetics of RecA protein function during conjugation. RecF recombination in recBC sbcB mutants is shown to be a much slower process than RecBC recombination in recBC+ sbcB+ strains, and is blocked by a mutation in lexA that prevents induction of RecA protein. Progress of the RecF pathway is greatly accelerated by a recAoc mutation which increases synthesis of RecA protein, but this does not restore recombination proficiency to a recBC sbcB lexA mutant. These results are interpreted to suggest that the RecF pathway directs integration of single-stranded Hfr DNA into the recipient chromosome whereas the RecBC pathway catalyses the exchange of largely double stranded DNA. This is consistent with the known stoichiometry of RecA protein catalysed heteroduplex DNA formation in vitro and with the delayed replication of RecF pathway recombinants which approximates to the time required for one round of DNA replication to generate homoduplex DNA. The regulation of the RecF pathway by lexA repressor is discussed in relation to the factors that govern the relative utilization of the two recombination pathways in wild-type cells.

Bacterial Proteins↗
PubMed1983

Clinical evaluation of the internal automatic cardioverter-defibrillator in survivors of sudden cardiac death.

An R-wave synchronous implantable automatic cardioverter-defibrillator (IACD) was evaluated in 12 patients with repeated episodes of cardiac arrest who remained refractory to medical and surgical therapy. Seven men and 5 women, average age 61 years, surgically received a complete IACD system. Coronary artery disease was found in 11 and the prolonged Q-T syndrome in 1. The average ejection fraction was 34%, and 6 patients had severe congestive heart failure (New York Heart Association class III or IV). The IACD is a completely implantable unit consisting of 2 bipolar lead systems. One system uses a lead in the superior vena cava and on the left ventricular apex through which the cardioverting pulse is delivered. The second system employs a close bipolar lead implanted in the ventricle for sensing rate. After the onset of ventricular tachycardia or fibrillation, the IACD automatically delivers approximately 25 J. Postoperative electrophysiologic study in 10 and spontaneous ventricular tachycardia in 1 patient demonstrated appropriate IACD function and successful conversion in all with an average of 18 +/- 4 seconds. The induced arrhythmias were ventricular tachycardia (160 to 300 beats/min) in 9 and ventricular fibrillation in 1. These data demonstrate that ventricular tachycardia, not ventricular fibrillation, was the predominant rhythm induced during programmed ventricular stimulation in these survivors of cardiac arrest and that the IACD effectively responded to a wide range of ventricular tachycardia rates as well as ventricular fibrillation. Use of the IACD offers an effective means of therapy for some patients who otherwise may not have survived.

Aged↗
PubMed1983

Depression in childhood and adolescence. A prospective study of six cases.

Two cases of recurrent major depression, three cases of dysthymic disorder (depressive neurosis), and one of adjustment disorder with depressed mood beginning in childhood or adolescence have been identified in the 133 subjects of the New York Longitudinal Study. The prospective behavioral data from early infancy to early adult life in each of the six cases are summarized. Differences in etiology are emphasized and the implications for treatment indicated. There was no evidence for a separate clinical entity of depression for the childhood period. Review of the longitudinal data did not show a significant earlier life tendency to negative mood temperamentally. The dysthymic and adjustment disorder cases also did not show significant differences in environmental stresses or parental functioning from other clinical cases in the longitudinal study without depressive symptoms.

Adjustment Disorders↗