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L W Brown

Publications and source records attributed to L W Brown.

9 recordsLinked to original sources
PubMed1992

Automated high-performance liquid chromatographic method for the determination of mianserin in plasma using electrochemical detection.

An automated high-performance liquid chromatographic method for the determination of mianserin in plasma is described. Extraction and injection of the samples were automatically done by the Gilson ASPEC system using C8, 100-mg Supelclean solid-phase extraction columns. The extracts were chromatographed on a reversed-phase C18 column (150 mm x 3.9 mm I.D.) with a phosphate buffer-acetonitrile-methanol mobile phase and the analytes detected electrochemically. Calibration curves were linear to at least 53.7 ng/ml at which the between-day relative standard deviation was 5% and the recovery 101%. The limit of quantification was 1.67 ng/ml at which the between-day relative standard deviation was 9% and the recovery 92% using a sample volume of 0.5 ml. The method was applied to the determination of mianserin in the plasma of normal human volunteers participating in a comparative bioavailability study.

Biological Availability↗
PubMed1979

Infant botulism.

Infant botulism is a unique neuromuscular disease affecting infants less than six months old. It is the result of intraintestinal toxin production by C. botulinum (toxi-infection). Characteristic symptoms include constipation, lethargy, and decreased feeding. Physical examination often reveals generalized hypotonia with cranial nerve impairment. Recovery is dependent on supportive care in an intensive care setting. The relationship of this disease to the sudden infant death syndrome requires further study.

Botulinum Antitoxin↗
PubMed1978

High-pressure liquid chromatographic determination of cycloheximide in ointment and suspension formulations.

A high-pressure liquid chromatographic procedure is described for the assay of the antibiotic cycloheximidein bulk drug and two experimental formulations. The method utilizes a reversed-phase C18 chromatographic column and refractive index detection. Possible impurities or degradation products, isocycloheximide, anhydrocycloheximide, and dimethylcyclohexone, are well separated from cycloheximide by this procedure. Complete extraction of cycloheximide from the formulations was obtained. The assay has a relative standard deviation of approximately 1%.

Chromatography, High Pressure Liquid↗
PubMed1978

High-pressure liquid chromatographic assays for clindamycin, clindamycin phosphate, and clindamycin palmitate.

High-pressure liquid chromatographic procedures are described for clindamycin, clindamycin palmitate, and clindamycin phosphate as bulk drugs and in formulations. All three procedures utilize a C18 reversed-phase chromatographic column with refractive index detection. The mobile phases are hydroalcoholic solutions containing dioctyl sodium sulfosuccinate or disodium ethylenediaminetetraacetate. Separations of related impurities or degradation products also are discussed. The relative standard deviations of the methods range from 0.8 to 1.8%.

Chromatography, High Pressure Liquid↗
PubMedDate not supplied

Wooden transnasal intracranial penetration: an unusual presentation.

A 2 1/2-year-old child presented to the emergency department with a wooden stick lodged firmly in her right nares. No nasal discharge or neurological abnormalities were noted at presentation. After plain radiographs failed to demonstrate any evidence of a foreign body, computed tomography (CT scan) was obtained that revealed a hypodense region in the right frontal lobe corresponding to the projected tract of the branch. The patient underwent a right frontal craniotomy with debridement of her contused right frontal lobe. She was discharged 8 days postoperatively without evidence of neurologic sequelae. This case illustrates an unusual presentation of intracranial penetration, with only six similar cases found in the literature. It also highlights the need for the emergency physician to be concerned about intracranial penetration when treating intranasal foreign bodies, particularly those of the nonmetallic type. The literature is reviewed regarding transnasal intracranial penetration by wooden foreign bodies.

Child, Preschool↗
PubMedDate not supplied

Differential diagnosis of infant botulism.

Clinical investigations of infants hospitalized with botulism demonstrate a remarkable uniformity of complaints and physical findings. Constipation precedes a course of progressive weakness and cranial nerve dysfunction. Examination reveals hypotonia, hyporeflexia, and a variable pattern of involvement of the motor cranial nerves. Initial laboratory investigations should include electrodiagnostic tests, because findings of an incremental response to rapid, repetitive nerve stimulation and of brief, small-amplitude motor units on electromyography are virtually pathognomonic of botulism in the infant. Differential diagnosis includes disorders that may produce generalized depression of the central nervous system, such as septicemia, meningitis, metabolic disturbances, and intoxications. Specific involvement of the neuromuscular system includes acute polyneuropathies, diseases of the anterior horn cell, congenital myopathies or muscular dystrophy, and neonatal myasthenia gravis. Recent studies have expanded the clinical spectrum of infant botulism to include some cases of sudden infant death syndrome and otherwise nonspecific constipation.

Action Potentials↗