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Biomedical subjects

D Sutton

Publications and source records attributed to D Sutton.

At least 55 records · Page 3Linked to original sources
PubMed1985

Profile analysis in facial plastic surgery.

We devised a simple and reliable method of profile analysis for facial plastic surgery. Profile photographs are taken with the natural head position technique. Key cephalometric landmarks are then identified and digitalized from either photographs or slides, using a digitalizer with a resolution of 0.001 in. The digitalizing pad is connected to a microcomputer. The menu-driven software allows selection of multiple functions from different cephalometric systems. Data can be stored on disk for future analysis. The method is useful in preoperative planning and postoperative evaluation of facial plastic surgery procedures.

Face↗
PubMed1985

Discriminative phonation in macaques: effects of anterior mesial cortex damage.

Lesion damage of the anterior midline hemisphere in M. mulatta results in impaired discriminative vocal activity. Destruction of the supplementary motor area (SMA) or pre-SMA greatly increases vocal response latency without similar changes in a non-vocal response. Discrimination and efficiency in performing the vocal and non-vocal responses are unaffected by this damage. The behavioral deficit reflects a specific loss in initiating vocal signals.

Animals↗
PubMed1985

Computed tomography in deep-seated peripheral neurofibromas.

Seven peripheral deep-seated neurofibromas in five patients were examined by computed tomography (CT). This proved to be the most helpful investigation for demonstrating the precise size, shape and localisation of the lesion prior to surgery. In some cases CT may suggest the correct diagnosis where this has not previously been considered.

Adult↗
PubMed1979

Vestibular effects of electrical stimulation of the cochlea. Monitored in the awake primate.

The effect of electrical stimulation of the cochlea on vestibular response was monitored in six rhesus monkeys. Eye movements and single-unit activity from the vestibular portion of the eighth nerve, vestibular nuclei, reticular formation, and abducens nucleus were observed while electrical stimulation was delivered through an implanted cochlear prosthesis. In one animal of this series, neural activity from the inferior colliculus and cochlear nuclear complex was also recorded. Electrical stimulation elicited eye-movement responses in only one animal. In the animals from which single-unit activity was recorded, no positive vestibular effects were noted. In one animal of this study, responses were elicited from auditory structures by relatively low intensities of electrical stimulation.

Acoustic Stimulation↗
PubMed1978

Cerebellar regulation of phonation in rhesus monkey (Macaca mulatta).

Five rhesus monkeys (Macaca mulatta) were trained to emit a "coo" vocalization with a duration of at least 500 msec. After stable performance was achieved cerebellar lesions were introduced, and various pre- and postlesion measures of phonation and of laryngeal EMG activity were compared to assess the effects of the lesions. The phonatory changes were interpreted with respect to possible laryngeal or respiratory modifications. The relation between fundamental frequency and intensity of phonation was changed in some animals, with no obvious alterations in either fundamental frequency or intensity considered separately. Intensity of phonation was decreased while duration was prolonged in two animals. Fundamental frequency of phonation was also affected in some animals. Reliable laryngeal EMG was obtained in two animals and was affected by cerebellar lesions. These results indicate that normal cerebellar function is involved in the control of fundamental frequency, intensity, duration, and the coordination of the laryngeal and respiratory systems for the control of phonation.

Acoustics↗
PubMed1978

Detection and pathogenesis of visceral calcification in dialysis patients and patients with malignant disease.

Scintiscanning to detect the uptake of bone-seeking radioactive isotopes by soft tissue is a promising technique for the in vivo study of visceral calcification. Visceral uptake of such radioisotopes was studied in 40 patients: 22 undergoing long-term dialysis, 9 with malignant disease and hypercalcemia and 9 with primary hyperparathyroidism and hypercalcemia.Fifteen patients, 11 undergoing dialysis and 4 with malignant disease, had radioisotope uptake in the lungs, and 5, 3 undergoing dialysis and 2 with malignant disease, had uptake in the stomach. None of the patients with primary hyperparathyroidism had visceral uptake, nor did the patients with uptake have radiologic evidence of pulmonary or gastric calcification. The dialysis patients with visceral uptake had a mean calcium x phosphate product of 84.3 +/- 23.7 (standard deviation), which was significantly greater (P < 0.001) than that of patients without such uptake (59.2 +/- 14.0). Similarly, in patients with malignant disease and visceral uptake the Ca x P product was 72.2 +/- 6.4 - significantly greater (P < 0.005) than that of patients without such uptake (49.3 +/- 6.7).These findings indicate that scintiscanning for the visceral uptake of a bone-seeking radioisotope is a simple and effective technique for the in vivo study of visceral calcification. An elevation in the Ca x P product seems to be the single most important factor in the production of visceral calcification.

Adult↗
PubMed1978

Visceral calcification and the CaXP product.

The authors studied the presence of visceral calcification as evidenced by the visceral uptake of bone-seeking radionuclides during the course of a bone scan among 22 patients with terminal renal failure maintained on dialysis, nine patients with hypercalcemia secondary to malignancy, and nine patients with primary hyperparathyroidism. Uptake by the lungs or stomach was observed in 11 renal failure patients (50%) and in four of those with malignancy and hypercalcemia (44%). None of the patients with primary hyperparathyroidism had evidence of visceral calcification. The serum CaXP product was significantly higher among those with visceral calcification than those without. The results of this study indicate that a CaXP product of 60 represents the saturation product of calcium phosphate in serum above which spontaneous precipitation of this salt may occur in such viscera as stomach and lungs.

Adult↗
PubMed1978

Effects of cerebellar lesions on monkey jaw-force control: implications for understanding ataxic dysarthria.

Eight macaques were trained on one of two isometric force regulation tasks. Six animals were trained to maintain a static force for a 2-sec period, and two animals were trained to make a rapid series of bites on a force transducer four times in succession. Electromyographic (EMG) electrodes were chronically implanted into temporalis and masseter muscles. Lesions were made in the cerebellum in seven monkeys and a control surgery with no neural damage was performed on one monkey. Following cerebellar lesions, the abilities of the monkeys to maintain a static isometric force for 2 sec were impaired. Animals overshot the correct force band and force tremors increased in amplitude following the lesions. Cerebellar lesions were followed also by a reduction in biting frequency from about 3 Hz to 2 Hz. Measurements of the temporalis EMG indicated that the reduced biting rate was associated primarily with a prolongation of the inter-EMG interval and secondarily with a prolongation of the EMG duration. Changes in jaw-force regulation following the lesions appear to be similar to the types of changes observed in arm control in monkeys, and in the speech of persons with ataxic dysarthria.

Action Potentials↗
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↗