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Biomedical subjects

R C Bone

Publications and source records attributed to R C Bone.

270 records · Page 15Linked to original sources
PubMedDate not supplied

Compliance and dynamic characteristics curves in acute respiratory failure.

Routine measurement of pressure-volume curves of the lungs and thorax in seven patients treated with continuous mechanical ventilation provided supportive evidence for the presence or absence of cardiogenic pulmonary edema, noncardiogenic pulmonary edema, pneumonia, bronchospasm, mucous plugging, intubation of mainstem bronchus, atelectasis, and results of subsequent therapy. Those conditions associated with predominantly airway disease altered dynamic more than static pressure-volume measurements. Those conditions associated with parenchymal lung disease or loss of lung volume generally altered both dynamic and static pressure-volume measurements. The effectiveness of treatment of these diseases could be monitored by their effect on the pressure-volume curve. The determination of pressure-volume measurements are simple, noninvasive, and can be accomplished within minutes. The routine use of these measurements should be one of the monitoring procedures performed in patients treated with mechanical ventilation.

Acute Disease↗
PubMedDate not supplied

Treatment of adult respiratory distress syndrome with diuretics, dialysis, and positive end-expiratory pressure.

Twelve patients were treated prospectively for adult respiratory distress syndrome with diuresis and low levels (less than or equal to 20 mm Hg) of positive end-expiratory pressure. Eight patients responded to diuretics and two to dialysis by an increase in static compliance of the respiratory system, improvement in arterial oxygen tension and an increased urine output. Two patients did not respond with an improvement in these tests. Responses were transient and multiple doses were required to produce a sustained effect. Even with improvement of pulmonary function after treatment, the mortality was 67%, similar to that reported from other centers since 1975. Recently a new treatment protocol has been proposed that uses high positive end-expiratory pressure (greater than or equal to 20 mm Hg) early in the course of adult repiratory distress syndrome; mortality using this technique was 20%. The difference in survival may be more apparent than real since each center has a unique population of patients and time of initial therapeutic intervention. A randomized collaborative study comparing treatment protocols is needed.

Adolescent↗
PubMedDate not supplied

Epidermoid carcinoma arising from within an epidermoid inclusion cyst.

The unusual occurrence of epidermoid carcinoma within an inclusion cyst arising on the forehead of a patient is documented. The importance of any irregular change or clinically abnormal behavior in such a lesion is underscored and the necessity for routine histological examination of all tissue excised is reaffirmed.

Carcinoma, Squamous Cell↗
PubMedDate not supplied

Ewing's sarcoma of the mandible.

Ewing's sarcoma of the mandible occurs rarely; there have been less than 50 reported cases in the past 30 years and none of these have been in the otolaryngologic literature. They usually present in the second decade of life with pain and swelling of the soft tissue overlying the mandible. The diagnosis can only be made by an adequate mandibular biopsy, although x-rays and clinical presentation are helpful. Current treatment consists of radiation therapy and sequential adjuvant chemotherapy.

Adolescent↗
PubMedDate not supplied

Potentiation of kanamycin ototoxicity by a history of noise exposure.

Chinchillas were exposed to a noise band (1,414 to 5,656 Hz, 100-dB sound pressure level [SPL] for one hour) and treated with kanamycin (150 mg/kg a day until hearings loss was noted at 6.0 kHz) either separately, simultaneously, or sequentially. Simultaneous noise and kanamycin resulted in interactive potentiation of threshold shift and cochlear pathologic condition. Kanamycin treatment two months after noise exposure produced similar potentiation. No interaction was seen when noise exposure occurred one month after kanamycin treatment.

Animals↗
PubMedDate not supplied

Audiometric and histologic correlates of the interaction between kanamycin and subtraumatic levels of noise in the chinchilla.

Difficulty in assessment of potentiating interaction between noise-induced and kanamycin-induced injury of hearing is compounded by the great variability of intersubject response to the same drug dosage. However, in a given subject, response of the two cochleas to kanamycin intoxication may resonably be assumed to be symmetric. The present study was designed to utilize this similarity, in determining whether kanamycin intoxication would potentiate a normally subtraumatic noise stimulus. Under the experimental conditions outlined, it was found that after a dosage of 150 mg/kg/day of kanamycin given to a physiologic end point, normally subtraumatic noise caused consistent increas in hearing loss.

Acoustic Stimulation↗
PubMedDate not supplied

Element content of intracochlear fluids, outer hair cells, and stria vascularis as determined by energy-dispersive roentgen ray analysis.

Roentgen ray spectrometry was used to obtain element spectra from isolated samples of perilymph, endolymph, outer hair cells, and stria vascularis obtained by microdissection from the freeze-dried inner ears of chinchillas. The spectra of perilymph and endolymph residues indicated that no cross-contamination of the two cochlear fluids occurs during freeze-drying or sampling. The spectra of outer hair cells suggested that the extracellular fluid in the organ of Corti spaces is similar to perilymph in its ionic content. The spectra of stria vascularis samples indicated low sodium and high phosphorus contents. Energy-dispersive roentgen ray analysis of freeze-dried inner ears appears to be a promising method for low-contamination measurement of ion distribution in the cochlea.

Animals↗
PubMedDate not supplied

New strategies in nonantibiotic treatment of gram-negative sepsis.

Gram-negative bacterial infections are difficult to control and often lead to septic shock or septic syndrome. Many physiologic changes in sepsis are due to bacterial triggering of host responses. Improved understanding of these mechanisms has led to new treatment modalities that aim to block the runaway inflammatory process of sepsis. New therapeutic agents are currently being evaluated in animal and human studies. By combining these advances with adequate antibiotic therapy, it may be possible to improve overall survival in patients with gram-negative sepsis.

Animals↗
PubMedDate not supplied

Toward an epidemiology and natural history of SIRS (systemic inflammatory response syndrome)

BACKGROUND: New definitions for sepsis and the systemic inflammatory response syndrome (SIRS) have been established. Comparatively little is known, however, about the types of patients who will be included within these new definitions. OBJECTIVES: To determine what is--and what is not--known about the epidemiology and natural history of severe sepsis and SIRS. DESIGN: A comparative analysis of patient characteristics in the Methylprednisolone, Veterans Administration Systemic Sepsis, HA-1A, and E5 studies. RESULTS: At least 15% of patients in these studies had no documented infection; the proportion of all patients with severe SIRS and no documented infection is probably higher. Even among patients with presumed infection, less than half had bacteremia, and only about half had gram-negative infection or shock. The difference in the mean mortality rate of the combined studies at 14 days was 26%, while at 1 month it was 42%. Gram-negative sepsis and gram-positive sepsis seem to have similar mortality rates. Whether shock increases 30-day mortality is unclear. CONCLUSIONS: Patients with severe SIRS should not be assumed to have gram-negative infection; furthermore, data derived from studies of patients with gram-negative infection should be applied cautiously to all patients with SIRS. Studies of patients with sepsis or SIRS should include at least a 1-month follow-up if mortality is an end point. More consistent definitions of these disorders should permit more effective comparisons across studies.

Bacteremia↗