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Biomedical subjects

D Sutton

Publications and source records attributed to D Sutton.

At least 109 records · Page 6Linked to original sources
PubMed1978

Prolonged apnea in infant monkeys resulting from stimulation of superior laryngeal nerve.

We measured characteristics of apnea resulting from electrical stimulation of the superior laryngeal nerve (SLN) in 28 anesthetized infant monkeys ranging from a gestational age of 141 days to 49 days postterm and in four adult monkeys. Progressive reduction in ventilation accompanied weak suprathreshold SLN stimulation. Poststimulus apnea followed stronger stimulation. Apnea duration was directly proportional to stimulus duration, provided that stimulus intensity was at least 1.5 X threshold. Poststimulus apnea periods were briefer in older infants and did not occur in adults. Pao2 measurements in four animals showed that lower values were associated with the longer poststimulus apnea episodes. Upper airway resistance measurements obtained from a subglottal cannula revealed that glottal closure was transiently associated with the onset of SLN stimulation, but the degree of closure diminished during the course of stimulation and was not present during the subsequent period of apnea. The parameters of SLN stimulation determine specific changes in cardiovascular functions independently of their respiratory effects. The results suggest that a brief afferent input from the SLN may have prolonged effects on respiratory regulation in infants. These persisting effects may be an important consideration in sudden infant death syndrome mechanisms.

Airway Resistance↗
PubMed1977

Muscle spindles in nonhuman primate extrinsic auricular muscles.

Muscle spindles were sought in peri-auricular muscles of several primate species (rhesus monkey, woolly monkey, and baboon). Transverse sections cut at 10 mu and stained primarily by a silver impregnation technique were examined using light microscopy. Spindles were identified on the basis of standard criteria. Posterior and/or superior auricular muscles of each species were found to contain spindles. At least some muscles innervated by facial nerve have classical spindles as component structures.

Animals↗
PubMed1977

Infant primate larynx: developmental histology.

Laryngeal epithelium of monkeys (M. mulatta, M. nemestrina) ranging in age from late fetal to adult was found to undergo the following developmental changes: (1) progressive elaboration of commissural epithelium prenatally, reaching the adult form of pseudostratified columnar ciliated epithelium early in the postnatal period;(2) vocal process epithelium changing from cuboid to stratified squamous tissue during the late prenatal period, and (3) progressive increments in overall epithelial thicknees during development, reaching a maximum in the early postnatal period. Chondrocyte density of the cricoid and thyroid cartilage decreased during the late prenatal period, reaching the adult form at the neonatal stage. The evidence suggests that mechanical or metaplastic stresses do not determine the observed tissue changes.

Age Factors↗
PubMed1977

The radiological diagnosis of meningiomas, the impact of EMI scanning.

A review of the impact of computerized axial tomography on the radiological diagnosis of meningiomas is presented. Seventy-one intracranial and eight orbital cases have been examined by this new method using the 160 X 160 matrix. The diagnostic accuracy of the method is compared with established neuroradiological methods of examination (plain X rays, angiography, pneumography and isotope scanning). The new non-invasive method is undoubtedly the most accurate diagnostic tool yet available. It provided a specific diagnosis of meningioma in 77% of the intracranial cases without contrast enhancement and diagnosed the presence of tumour in a further 19% giving an overall tumour diagnosis of 96%. There were three false negatives (4%). After intravenous injection of contrast medium specific diagnosis of meningioma was made in a further six cases raising the specific diagnostic rate to 86%. Specific identification of intra-orbital meningiomas is more difficult though the presence of retro-orbital tumour was correctly diagnosed in all eight cases examined (100%). In none of our cases was a false positive diagnosis of tumour made. However, there are areas where a specific diagnosis of meningioma can only be made as part of a wider differential diagnosis. Apart from the orbit these include the suprasellar area, the cerebello-pontine angle, and the intraventricular regions. Occasionally also supratentorial gliomas or secondaries can simulate meningiomas.

Angiography↗
PubMed1977

Unusual arteriovenous communications presenting as cardiac murmurs in infancy. Report of three cases.

Three cases are decribed of infants presenting with murmurs in, or adjacent to, the thorax and considered to be cardiac. Later full investigations established that the murmurs were due to aorto-azygos fistula, vertebral arterio-venous fistula and intercostal angioma, respectively. While such lesions are extremely rare, the possibility of systemic arteriovenous communication should be considered in infants with atypical murmurs.

Aortography↗
PubMed1976

Sudden death in infant primates from induced laryngeal occlusion.

Thirteen infant and juvenile monkeys and baboons were studied in procedures designed to assess the functional characteristics of the upper airway, with special attention to the consequences of laryngeal nerve stimulation. In young animals, stimulation of the recurrent laryngeal nerve produced closure of the airway in sufficient degree and duration to cause death. Older juvenile monkeys were resistant to fatal laryngospasm induced by nerve stimulation. A variety of patterns of general autonomic response accompanied the airway changes. These results are consistent with (1) a laryngospasm hypothesis to account for certain terminal events in sudden infant death syndrome, and (2) prior observations of age-related general autonomic stability.

Age Factors↗
PubMed1976

Dimensions of the infant monkey upper airway.

Upper airways of infant Macaque monkeys were measured with respect to twenty-one dimensions of endocasts. Measurements were tabulated and plotted against age and body weight. Dimensions of the upper airway of these animals are characterized by variability.

Age Factors↗
PubMed1975

The radiological diagnosis of adrenal tumours.

The radiological diagnosis of adrenal tumours is reviewed with special reference to the literature and the author's personal experience. The clinical presentation varies widely with the different pathology and radiological investigation is decided largely by clinical assessment. The various methods of investigation are related to the individual problems with special reference to arteriography and phlebography. Thirteen cases of Conn's tumour have been diagnosed by adrenal phlebography and 18 cases of phaeochromocytoma have been investigated by arteriography. These cases are reviewed in detail.

Addison Disease↗