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Biomedical subjects

R W Clark

Publications and source records attributed to R W Clark.

At least 55 records · Page 3Linked to original sources

Protriptyline: an effective agent in the treatment of the narcolepsy-cataplexy syndrome and hypersomnia.

The authors present five case reports illustrating that 10-20 mg of protriptyline in a single dose at bedtime can effectively control arousal dysfunction (sleep drunkenness and hypersomnia) and the narcolepsycataplexy syndrome without the apparent development of tolerance and without the side effects that are frequent complications of treatment with other agents. Although protriptyline was efficacious in controlling symptoms, it was found to have relatively poor REM sleep-suppressing properties.

Adult↗

Orbital involvement in acute sinusitis. Lessons from 24 childhood patients.

The possibility of acute bacterial sinusitis should be considered in any child with sudden swelling about the orbit. Management is determined by the stage of the disease as well as by the sinus predominantly involved. Extraocular movements and proptosis are the best guidelines for therapy. When there is no proptosis and extraocular mobility is normal, conservative therapy with intravenous antibiotics and nasal decongestants is usually effective. When ocular mobility is impaired or proptosis develops, intranasal or external surgical drainage are usually required. Of 24 patients summarized in this paper, the ethmoid was the predominantly involved sinus in 12, the frontal in 7, the maxillary in 5. Only 4 of the 12 with predominant ethmoiditis required surgery. All 7 were predominant frontal involvement needed surgical drainage.

Abscess↗

The sucrose gradient and native DNA S20,W, an examination of measurement problems.

Sedimentation coefficients of T7, T2H AND T4 DNA were determined with isokinetic sucrose gradients in both 0.1 M and 1 M NaCl. The s values were completely equivalent to those measured by analytical ultracentrifuge and no reduction of s20,w was observed due to the presence of sucrose (anomalous sedimentation). s20,w values are calculated on the basis of both partial specific volume (v) and apparent specific volume (0). Using the latter value s20,w molecular weight relations are derived for 0.1 M and 1 M NaCl solvents. The glucosylation of T2H and T4 DNA appears to influence s20,w in a manner disproportionate to the molecular weight added by glucose.

Centrifugation, Density Gradient↗

Calculation of s20,w values using ultracentrifuge sedimentation data from linear sucrose gradients, an improved, simplified method.

A mathematical method is described for calculating the sedimentation coefficient (S20,W) with ultracentrifuge data from linear sucrose gradients. Gradient density and viscosity functions are precisely described by regression equations, which permit continuous evaluation (by integration) of the effects of gradient geometry on particle sedimentation. The results agree with previously used and more complex methods.

Centrifugation, Density Gradient↗

Flexible laryngoscopy in neonates, infants, and young children.

Flexible laryngoscopy was performed 453 times on 264 patients 4 years of age or younger. Sixty-five percent were under 6 months of age. Stridor was the indication for laryngoscopy in 60% of the patients. Problems secondary to intubation and poor voice each were indications in 12%. The most common finding was laryngomalacia, followed by laryngeal edema, normal larynges, and vocal cord paralysis or paresis. Subglottic stenosis was diagnosed in 17 patients. Flexible laryngoscopy is a relatively noninvasive, safe, and effective technique for examining the larynx of infants and young children.

Child, Preschool↗