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Biomedical subjects

E J Morgan

Publications and source records attributed to E J Morgan.

At least 19 recordsLinked to original sources
PubMed1997

Vocal tract resonance characteristics of adults with obstructive sleep apnea.

Vocal tract acoustic resonance was evaluated in a group of 10 untreated adult males with diagnosed obstructive sleep apnea (OSA) syndrome compared to 10 non-OSA adult males. Subjects were required to prolong the vowels /i/, /u/ and /a/, which were subsequently submitted to acoustic analysis of formant frequency and formant bandwidth. Results of the formant frequency analysis indicated lower formant values among the OSA group compared to the non-OSA group, for each vowel type. The lower formant frequencies among the OSA group were attributed to greater vocal tract length compared to non-OSA speakers. The corresponding formant bandwidths for each vowel produced by the OSA group were significantly wider compared to the non-OSA group. The wide formant bandwidths were interpreted to reflect significantly greater vocal tract damping in the OSA subjects, resulting from either excessive vocal tract tissue compliance or general size differences in the length and cross-sectional area of the vocal tract. Discussion focuses on the potential applications of acoustic analysis to aid in the diagnosis and follow-up treatment of OSA.

Adult↗
PubMed1995

Gastrogastric fistulas. A complication of divided gastric bypass surgery.

OBJECTIVE: This report warns that gastrogastric fistulas may follow the division of the stomach in bariatric surgery. SUMMARY BACKGROUND DATA: Although surgery is the most effective therapy for morbid obesity, the procedures are still undergoing evolution. One of the key elements in bariatric surgery is the partition of the stomach to develop a much smaller reservoir. The partition has been done with single layers of staples with almost universal failure and with double layers of staples with a failure rate of 11.8% when observed for a 12-year follow-up. METHODS: This report details the experience with a series of 100 consecutive patients in whom the partition was created by dividing the stomach. RESULTS: The course of six patients was complicated by gastrogastric fistulas. One of the patients had the gastric bypass as the initial bariatric operation; in the other five, the gastric bypasses were carried out to revise failed staple lines. Although one of the patients required drainage for a subphrenic abscess, two had only self-limited signs of infection. In the remaining three patients, there was no evidence of any complication. CONCLUSION: Gastrogastric fistulas followed division of the stomach in 6% of our gastric bypass operations. Methods for avoiding this complication include oversewing staple lines, using strong bites of tissue during the anastomosis, avoiding obstruction of the Roux-en-Y jejunal segment, and testing of the integrity of the anastomosis with methylene blue dyes. The ideal method for partition of the stomach remains to be developed.

Gastric Bypass↗
PubMed1992

Surgical treatment of obesity and its effect on diabetes: 10-y follow-up.

Since 1980 we have performed the identical Greenville gastric bypass (GGB) procedure on 479 morbidly obese patients with an acceptable morbidity and a mortality rate of 1.2%. The weight loss in the series was well maintained over the follow-up period of 10 y. The GGB can control non-insulin-dependent diabetes mellitus (NIDDM) in most patients. The group of 479 patients included 101 (21%) with NIDDM and another 62 (13%) who were glucose impaired. Of these 163 individuals, 141 reverted to normal and only 22 (5%) remained with inadequate control of their carbohydrate metabolism. Those patients who were older or whose diabetes was of longer duration were less likely to revert to normal values. The gastric bypass operation is an effective approach for the treatment of morbid obesity. Along with its control of weight, the operation also controls the hyperglycemia, hyperinsulinemia, and insulin resistance of the majority of patients with either glucose impairment or frank NIDDM.

Adult↗
PubMed1991

Alcohol and sleep apnea.

Acute ingestion of ethanol induces vasodilation and swelling of respiratory mucosa; it depresses respiratory centers resulting in hypotonia of oropharyngeal dilator muscles and inducing or aggravating sleep apnea. However, no association between the sleep apnea syndrome (SAS) and Alcohol Use Disorders (AUD) has been demonstrated.

Alcoholism↗
PubMed1982

Pulmonary function in infectious mononucleosis.

Infectious mononucleosis (IM) is common among students. These patients often complain of fatigue and dyspnea. To determine whether IM alters respiratory function, we performed spirometric, single-breath diffusing capacity, and maximal static respiratory pressure tests on seven patients with symptoms of IM. These studies were repeated two weeks later and the respiratory pressures were repeated five months later. Each patient served as his own control. Pulmonary function was normal except for respiratory pressures, which were initially low. These pressures, still low after two weeks, improved significantly after five months. We concluded that IM is associated with transient respiratory muscle weakness.

Adolescent↗
PubMed1981

Control of breathing during prolonged exercise.

Ventilation (VE) climbs steadily throughout prolonged heavy exercise. While this VE "drift" has implications for the adequacy of gas exchange in long-term exercise, its mechanism remains unknown. We examined the behavior of previously proposed mediators of VE drift during one hour of cycle ergometer exercise at constant work rate requiring 2/3 VO2 max in 10 subjects. VE increased 13% from 12 to 61 min of exercise (P less than 0.05). Although body core temperature rose as VE rose, equal elevation of core temperature by passive means failed to increase exercise VE. Rising VE during the hour of exercise occurred despite unchanged arterial pH, PCO2, and lactate and despite unchanged VCO2. Thus, all of the VE increase was calculated to be due to increased dead space ventilation (VD). Tidal volume (VT) was unchanged, while VD/VT rose from 0.16 to 0.24 from 12 to 61 min of work (P less than 0.05). These results show that increased body core temperature does not mediate VE drift, and that changes in previously proposed mediators (arterial pH, arterial lactate, and VCO2) are not necessary for a slow VE rise to occur in prolonged heavy exercise.

Body Temperature↗
PubMed1979

Influence of exercise hyperthermia on exercise breathing pattern.

Passive elevation of the body core temperature (Tc) induces rapid, shallow breathing in resting man. We wondered if exercise-induced Tc elevation would also lead to decreased tidal volume (VT) and increased breathing frequency (f) during exercise. To investigate this question, 10 subjects each performed 47 min of cycle ergometer exercise at 50--60% of the maximal aerobic capacity, with the work rate adjusted to maintain ventilation (VE) constant. This long ride raised mean Tc (rectal) 0.8 degrees C. Before and immediately after the long ride, ranges of VE and VT were obtained from short 6-min rides that progressed from unloaded pedaling to the anaerobic threshold. At the constant VE of the long ride, f rose and VT fell as Tc rose (P less than 0.05). The fall in VT was associated with a fall in inspiratory time (TI); drive (VT/TI) and timing (TI/Ttot)components of VE were unchanged. These effects were consistent over the entire range of VE obtained from the short 6-min rides. Passive heating in warm water to produce equal Tc elevation in the same subjects yielded similar exercise breathing-pattern changes. These findings suggest that increased Tc mediates the VT fall during prolonged exercise, possibly through stimulation of the central respiratory pacemaker.

Body Temperature↗
PubMed1979

The effects of unanesthetized arterial puncture on PCO2 and pH.

Painful unanesthetized arterial puncture may produce transient hyperventilation, and this hyperventilation might alter resting values of arterial pH and PCO2. We investigated this possibility by comparing pH and PCO2 values of blood samples obtained by arterial puncture with values of arterialized venous blood obtained by a painless method. In 19 consecutive subjects, virtually no difference in pH or PCO2 resulted from an arterial puncture that could not be attributed to the inherent precision of the measuring instrument. Mean +/- SEM pH was identical (7.45 +/- 0.05) both before and during an arterial puncture, as was PCO2 (34.4 +/- 1.2 mm Hg). The variation (SD) in PCO2 within an individual subject was +/- 1.7 mm Hg, which was almost identical to the inherent precision of the Radiometer ABL-2 acid base laboratory (SD, +/- 1.32). We conclude that an unanesthetized arterial puncture provides an accurate measurement of resting pH and PCO2.

Anxiety↗
PubMed1979

Silicosis and tuberculosis.

Two subjects had silicosis complicated by tuberculosis. In both patients, there was a relapse of the tuberculosis after chemotherapy was discontinued, in one case after 13 years of therapy with isoniazid and p-aminosalicylic acid. It would appear that the risk of tuberculosis in subjects with silicosis persists for life, and the suggestion is made that chemotherapy should be continued indefinitely.

Adult↗
PubMed1978

The obesity-hypoventilation syndrome.

The triad of obesity, hypoventilation and inordinate hypersomnolence characterizes the obesity-hypoventilation syndrome. The reasons for daytime hypoventilation appear related to decreased chemical drives to breathe combined with the added physical impediment of extreme obesity. When the physiology of sleep was investigated in patients with this syndrome, intermittent nocturnal obstructive apneas were documented that produced blood gas abnormalities, arrhythmias and serious elevations of both pulmonary and systemic pressures. The obstructive apneas are due to intermittent loss of muscle tone of the tongue resulting in its prolapse against the posterior pharynx. The special importance of the obesity-hypoventilation syndrome lies in its being an example of a disorder of sleep and breathing that can appear in widely different clinical settings. Therapeutic measures include weight loss, progestational agents or permanent tracheostomy.

Apnea↗