Mahdi A. Shkoukani

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It has been proposed that the difference in sleep apnea prevalence is related to gender differences in upper airway anatomy and physiology. To explain the prevalence difference, we hypothesized that men would have an increased upper airway resistance and increased critical closing pressure (Pcrit) compared with women. In protocol 1, resistance at two(More)
UNLABELLED Episodic hypoxia (EH) is followed by increased ventilatory motor output in the recovery period indicative of long-term facilitation (LTF). We hypothesized that episodic hypoxia evokes LTF of genioglossus (GG) muscle activity in humans during non-rapid eye movement sleep (NREM) sleep. We studied 12 normal non-flow limited humans during stable NREM(More)
Long-term facilitation (LTF) is a prolonged increase in ventilatory motor output after episodic peripheral chemoreceptor stimulation. We have previously shown that LTF is activated during sleep following repetitive hypoxia in snorers (Babcock MA and Badr MS. Sleep 21: 709-716, 1998). The purpose of this study was 1) to ascertain the relative contribution of(More)
We hypothesized that long-term facilitation (LTF) is due to decreased upper airway resistance (Rua). We studied 11 normal subjects during stable non-rapid eye movement sleep. We induced brief isocapnic hypoxia (inspired O(2) fraction = 8%) (3 min) followed by 5 min of room air. This sequence was repeated 10 times. Measurements were obtained during control,(More)
The physiological significance of inspiratory flow limitation (IFL) has recently been recognized, but methods of detecting IFL can be subjective. We sought to develop a mathematical model of the upper airway pressure-flow relationship that would objectively detect flow limitation. We present a theoretical discussion that predicts that a polynomial function(More)
OBJECTIVE The aim of this study was to determine whether the incidence of facial fractures has changed in the United States since 1990. STUDY DESIGN This study is a retrospective review of all nonpediatric inpatient and outpatient facilities of the Detroit Medical Center from 1990 to 2011 and weighted national inpatient estimates from 1993 to 2010 using(More)
Altered chemoresponsiveness has been postulated to explain the gender difference in the incidence of sleep disordered breathing (SDB). The purpose of this investigation was to ascertain a gender difference in the effect of hypocapnic hypoxia on ventilation. Hypocapnic hypoxia was induced in stable NREM sleep for 3 min periods. In the first analysis, hypoxic(More)
We have previously shown that the pressure-flow relationship of the upper airway during nonrapid eye movement sleep can be characterized by a polynomial equation: F(P) = AP(3) + BP(2) + CP + D. On the basis of fluid mechanic principles, we hypothesized that we could objectively calculate upper airway resistance (R(UA)) using the polynomial equation. We(More)
Despite a considerable expansion in our therapeutic repertoire for management of other malignancies, mortality from head and neck cancer (HNC) has not significantly improved in recent decades. Upon normalizing National Institutes of Health-awarded R01 and R01-equivalent grants by incidence, thyroid cancer ($214) and HNC ($1329) received the fewest funding(More)