Biomedical subjects

D Yamashita

Publications and source records attributed to D Yamashita.

4 recordsLinked to original sources

PubMed2005

Post-exposure treatment attenuates noise-induced hearing loss.

Reactive oxygen species (ROS) and reactive nitrogen species (RNS) are involved in sensory cell and neural death in the peripheral nervous system, including damage induced by noise trauma. Antioxidant administration prior to or concomitant with noise exposure can prevent auditory deficits, but the efficacy of a delayed treatment is not known. We have recently found continued reactive oxygen species/reactive nitrogen species formation in the ear for 7-10 days following noise exposure and reasoned that antioxidant intervention during this period should also reduce noise-induced hearing loss. Guinea-pigs were subjected to 4 kHz octave band noise at 120 decibels sound- pressure-level (dB SPL) for 5 hours and received treatment with ROS and RNS scavengers (salicylate and trolox) beginning 3 days prior, 1 hour, 1, 3, or 5 days after noise exposure. Auditory thresholds were assessed by sound-evoked auditory brainstem response at 4, 8, and 16 kHz, before and 10 days after noise exposure. Hair cell damage was analyzed by quantitative histology, and free radical activity was determined immunohistochemically via 4-hydroxynonenal and nitrotyrosine as markers of reactive oxygen species and reactive nitrogen species action. Delivered up to 3 days after noise exposure, salicylate and trolox significantly reduced auditory brainstem response deficits, reduced hair cell damage, and decreased reactive oxygen species and reactive nitrogen species formation. Earlier drug treatment was more effective than later treatment. Our results detail a window of opportunity for rescue from noise trauma, and provide evidence for both morphological and functional protection by delayed pharmacological intervention.

Aldehydes↗

PubMed1998

Initial evaluation and management of gunshot wounds to the face.

BACKGROUND: The literature on early management of gunshot wounds (GSWs) to the face is scant, with only six series reported in the English-language literature in the last 12 years. In the current study, we present a large series from a busy trauma center in an effort to identify early diagnostic and therapeutic problems and recommend management guidelines. METHODS: Retrospective analysis was done for all GSWs of the face during a 4-year period. Data were obtained from the Trauma Registry and Trauma Patient Summary hard copies. RESULTS: During the study period, there were 4,139 admissions for GSWs, with 247 (6%) involving the face. An associated brain trauma was found in 42 patients (17.0%), and cervical spine fracture was found in 20 patients (8.1%) with GSWs to the face. In 43 patients (17.4%), there was a need for emergency airway control because of local hematoma or edema. Angiography was performed in 70 patients (28.3%) for evaluation of a large hematoma or continuous bleeding, and in 10 of these patients successful embolization of bleeders was achieved. No patient required operative control of bleeding from facial structures. Overall, only 96 patients (38.9%) underwent operation for soft-tissue repair or reduction of facial bone fractures. There were 36 deaths (14.5%) from severe brain injury or severe bleeding from associated chest or abdominal injuries. No death occurred in isolated GSWs to the face. CONCLUSION: Most civilian GSWs can safely be managed nonoperatively. Airway control is required in a significant number of patients and should be established very early. Bleeding from the face is best controlled angiographically. The brain and cervical spine should be aggressively assessed radiologically because of the high incidence of associated trauma.

Adolescent↗

PubMed1985

Evaluating RECONSIDER. A computer program for diagnostic prompting.

RECONSIDER, a computer program designed to perform as a diagnostic prompting aid, was evaluated for its ability to include the correct diagnosis in an ordered computed list of candidate diseases. The study was performed using 100 consecutive first admissions to the medical service of a university hospital, where the individuals entering the data into the program were blind to all but a limited set of findings known at time of admission. Each person entering the data created one or more lists of diagnostic possibilities (versions) using the program. The program suggested the correct diagnosis within the first 40 on its list 61% (498/797) of the time; the correct diagnosis was present with the first 40 in at least one version 93% (98/105) of the time. Performance was found to be best with cases having a single diagnosis and when more terms were entered into the program.

Computers↗

PubMed1979

The relationship of an overt commitment to the frequency and speed of compliance with symptom reporting.

This study investigates the effect of an overt verbal commitment on compliance with returning symptom report cards. Patients in two flu inoculation clinics were placed in an experimental condition. Patients in two other comparable flu inoculation clinics were placed in the control condition. After receiving their inoculations, all patients were asked to mail back a postcard after 48 hours that indicated the occurance of any symptoms. Patients in the experimental condition were asked if they would comply with the request. Patients in the control condition were not asked for a commitment. Patients in the experimental condition returned significantly more cards and significantly sooner than those in the control condition. This technique has both clinical and research applications.

Behavior Therapy↗