Continuous maintenance of an appropriate position of the mandible and head purely by manual manipulation is difficult, although the maneuver can restore airway patency during sleep and anesthesia. The aim of this paper was to examine the effect of head elevation with jaw closure using a remote-controlled airbag device, such as the airbag system, on passive upper airway collapsibility during propofol anesthesia. Seven male subjects were studied.
View Article and Find Full Text PDFThe aim of this study was to examine the effect of chewing efforts on sensory and pain thresholds of the orofacial skin of symptom-free subjects. Fourteen healthy volunteers were recruited. Using a stair-case method, the tactile detection threshold (TDT) and the filament-prick pain detection threshold (FPT) on the cheek skin (CS) and the skin overlying the palm side of the thenar skin (TS) were measured before and after chewing gum for 5 min (Time 1: T1) and keeping the jaw relaxed for 5 min (Time 2: T2) as a control.
View Article and Find Full Text PDFPurpose: The aim of this study was to examine the effect of nonfunctional tooth contact on sensory threshold (tactile detection threshold: TDT) and pain thresholds (filament-prick pain detection threshold: FPT; pressure pain threshold: PPT) in the orofacial region of patients with myofascial pain of the jaw muscles.
Methods: The study was performed on 36 subjects: 20 normal subjects and 16 patients. Using a stair-case method, TDT and FPT were measured by Semmes-Weinstein monofilaments, on the cheek skin (CS) overlying the masseter muscles (MM) and on the skin overlying the palm side of the thenar skin (TS).
Study Objective: To determine the mechanical upper airway properties and compensatory neuromuscular responses to obstruction during propofol anesthesia in the follicular and luteal phases of the menstrual cycle.
Design: Prospective, randomized study.
Setting: University-affiliated hospital.
Background: Head elevation can restore airway patency during anesthesia, although its effect may be offset by concomitant bite opening or accidental neck flexion. The aim of this study is to examine the effect of head elevation on the passive upper airway collapsibility during propofol anesthesia.
Method: Twenty male subjects were studied, randomized to one of two experimental groups: fixed-jaw or free-jaw.
The effects of systemic administration of exogenous nitric oxide (NO) donor on hepatic arterial buffer response (HABR) have not yet been studied in an anesthetized model. In this study, 28 anesthetized pigs received administration of sodium nitroprusside (SNP) or nitroglycerin (NTG) as exogenous NO donors. Pressure-flow (P-Q) relationships in the hepatic artery defined the pressure at zero flow (P(Qha = 0)) and flow-dependent resistance (R).
View Article and Find Full Text PDFDysgeusia causes a decrease in appetite, and it is one of the major factors in undernutrition. Dysgeusia is elicited by numerous causes, and in many cases it is still difficult to treat the various symptoms complained of by patients. We herein report a case in which dysgeusia was improved by transient cooling of the mouth.
View Article and Find Full Text PDFBackground: Upper airway patency may be compromised during sleep and anesthesia by either anatomical alterations (mechanical properties) or disturbances in the neural control (compensatory neuromuscular responses). The pathophysiology of upper airway obstruction during anesthesia may differ between men and women. Recently, we reported that the upper airway mechanical properties were comparable with those found during natural nonrapid eye movement sleep, as evaluated by measurements of passive critical closing pressure (P(CRIT)) and upstream resistance (R(US)) during midazolam sedation.
View Article and Find Full Text PDFUpper airway obstruction during sleep can trigger compensatory neuromuscular responses and/or prolong inspiration in order to maintain adequate minute ventilation. The aim of this study was to investigate the strength of these compensatory responses during upper airway obstruction during propofol anesthesia. We assessed respiratory timing and upper airway responses to decreases in nasal pressure in nine propofol anesthetized normal subjects under condition of decreased (passive) and increased (active) neuromuscular activity.
View Article and Find Full Text PDFSome intravenous anesthetic agents such as midazolam are known to induce anterograde and retrograde amnesia. We analyzed the effect of midazolam by the conditioned taste aversion (CTA) acquisition and retention. After the rats were offered 0.
View Article and Find Full Text PDFThe gag reflex is a somatic natural response in which the body attempts to eliminate instruments or agents from the oral cavity by muscle contraction. Some patients suffered from such severe retching that behavioral techniques did not sufficiently reduce gagging in dentistry. In these patients, pharmacological management was thought to be the last alternative to eliminate the reflex.
View Article and Find Full Text PDFStudy Objective: To test the hypothesis that the change of body and head position affects upper airway patency during midazolam sedation.
Design: Clinical study using 30 healthy subjects.
Setting: Research unit for sleep study.
Brain-derived neurotrophic factor (BDNF) is a family of neurotrophins that plays crucial roles in neural development, survival, maintenance and regeneration both in central and peripheral nervous systems. To examine the effects of BDNF on mastication, jaw movement trajectories and masticatory muscle activities were electrophysiologically investigated in BDNF-deficient mice, compared with those of littermate wild-type mice. BDNF-deficient mice showed less number of chewing strokes and more irregular chewing pattern during mastication than wild-type mice.
View Article and Find Full Text PDFRecent studies have indicated that nociceptors can be classified into various types according to their physiological properties. These studies have clarified that the frequency distribution of various nociceptor types is different among body sites and animal species. In the present study, we investigated the physiological properties of rat's periodontal nociceptors in an in vitro jaw-nerve preparation.
View Article and Find Full Text PDFSubhypnotic doses of propofol accelerate extinction of conditioned taste aversion. Some intravenous anesthetic agents including propofol is known to induce anterograde and retrograde amnesia. We evaluated whether propofol affect the long-term memory formed by the conditioned taste aversion (CTA) paradigm.
View Article and Find Full Text PDFAt the primary structure level, the 90-kDa heat shock protein (HSP90) is composed of three regions: the N-terminal (Met(1)-Arg(400)), middle (Glu(401)-Lys(615)), and C-terminal (Asp(621)-Asp(732)) regions. In the present study, we investigated potential subregion structures of these three regions and their roles. Limited proteolysis revealed that the N-terminal region could be split into two fragments carrying residues Met(1) to Lys(281) (or Lys(283)) and Glu(282) (or Tyr(284)) to Arg(400).
View Article and Find Full Text PDF