Search PubMed⌕ Search

Biomedical subjects

B L Johnson

Publications and source records attributed to B L Johnson.

At least 109 records · Page 6Linked to original sources
PubMed1983

Treatment of first episodes of genital herpes simplex virus infection with oral acyclovir. A randomized double-blind controlled trial in normal subjects.

We performed a double-blind placebo-controlled trial of oral acyclovir in the treatment of first episodes of genital herpes simplex virus infections in 48 young adults (31 women and 17 men). Subjects were randomized to receive either placebo or acyclovir (200 mg per dose) five times daily for 10 days; they were examined on at least eight visits until healed and at monthly visits thereafter. Acyclovir treatment, as compared with placebo, significantly reduced virus shedding, new lesion formation after 48 hours, and the duration of genital lesions in both men and women. The total duration and severity of clinical symptoms (such as pain, adenopathy, dysuria, and malaise) were significantly reduced by acyclovir in both men and women by the third and fourth day, respectively (P less than or equal to 0.025), as compared with placebo. No toxicity was observed. Recurrence rates have so far been similar in placebo and acyclovir recipients. Oral acyclovir treatment of first-episode genital herpes simplex virus infections is clinically effective, but it does not seem to prevent virus latency or associated recurrent disease.

Acyclovir↗
PubMed1983

Fuchs' adenoma affecting the peripheral iris.

An elevated, pigmented lesion of the peripheral iris developed in a 73-year-old woman. The lesion was believed to be a malignant melanoma and was excised at the time of routine cataract extraction. Pathologic examination disclosed a Fuchs' adenoma. These lesions are common in the elderly and are almost invariably clinically silent. This case, however, demonstrates that under rare circumstances a Fuchs' adenoma may induce cataractous changes or produce clinical findings that can mimic an iris melanoma.

Adenoma↗
PubMed1983

Orbital fine-needle aspiration biopsy in patients with cavernous sinus syndrome.

The authors report their experience with five patients presenting with cavernous sinus syndrome who, on computerized tomography (CT) studies, were shown to have a lesion simultaneously involving the cavernous sinus and a portion of the orbit. All patients underwent an orbital fine-needle aspiration biopsy (FNAB). A specific cytological diagnosis was made in three of the five patients. To obtain pathological diagnosis in the case of cavernous sinus tumors, invasive diagnostic procedures are sometimes necessary. Extension of lesions from the cavernous sinus into adjacent areas should be carefully looked for on CT scans. In the specific subset of patients with cavernous sinus tumors and simultaneous orbital involvement, orbital FNAB may provide a simple alternative to more invasive procedures. The limitations of the procedure are discussed.

Adenocarcinoma↗
PubMed1983

Effects on the peripheral nervous system of workers' exposure to carbon disulfide.

An evaluation of the effects of occupational exposure to carbon disulfide was performed in a sample of 156 male viscose rayon workers. A composite group of 233 workers drawn from two other artificial fiber plants located on the same premises as the rayon plant was used for comparison. Effects of CS2 on the peripheral nervous system (PNS) were evaluated in ulnar and peroneal nerves using measurements of maximum motor nerve conduction velocity (MCV) and distal latency; and sensory conduction velocity (SCV) in the sural nerve. Self-reported symptoms related to PNS disorders were also obtained from each study participant. Industrial hygiene records showed the rayon workers to have had CS2 exposures that generally had not exceeded 20 ppm. The overall mean number of years of CS2 exposure was 12.1 years (+/- 6.9 S.D.). The viscose rayon workers were divided prior to the study into three groups according to historical mean CS2 levels calculated for job titles, and area and personal CS2 samples were obtained during the conduct of the study to characterize each job. For these three groups the median CS2 levels were measured to be 1.0, 4.1 and 7.6 ppm. The comparison group's median CS2 level approximated 0.2 ppm. Results showed CS2-exposed workers to have small but statistically significant (p less than .05) reductions in sural SCV and peroneal MCV. Other neurophysiological measures consisting of distal latency, residual latency, and muscle or nerve action potential amplitudes showed no significant differences between study groups. A reduction in the ratio of amplitudes of muscle action potentials obtained from peroneal nerve stimulation was significant (p less than .05). Reductions in the peroneal nerve MCV were found to be related, in a dose response sense, to workers' cumulative exposure to CS2. No increase attributable to CS2 was found in the prevalence of symptoms related to PNS disorders. The results from this study generally agree with similar findings from Finland, Sweden and Italy, but at CS2 exposure levels lower than those previously reported for occupational exposure.

Action Potentials↗
PubMed1983

A behavioral examination of workers exposed to carbon disulfide.

The present study was conducted with a group of 298 textile workers. Of the workers studied 131 had worked at least one year in a rayon plant where there were CS2 exposures of varying degree, but generally below 20 ppm, which is the U.S. occupational exposure limit. The remaining 167, who worked in plants that manufactured other textiles where any CS2 exposure was considered inconsequential, comprised a comparison group. The 298 workers completed a checklist of symptoms characteristic of various neurobehavioral syndromes. Mood and excitability were measured by the Profile of Mood States, and by a mania scale from the Minnesota Multiphasic Personality Inventory, respectively. Cognitive and psychomotor performance was studied by application of four standard tasks: the Neisser letter search, the memory span test, the eye-hand coordination test, and a combined simple and complex reaction time test. The results indicated an absence of behavioral changes of any major significance, suggesting that effects here may only be marginal. The major finding related to the significant cluster of reported symptoms of neurobehavioral ailments.

Adult↗
PubMed1982

A histopathologic study of bilateral aphakia with a unilateral intraocular lens in a child.

A 7-year-old boy who had had electrically induced cataracts since he was 6 months old underwent a lens extraction by phacoemulsification in his right eye. He later refused to wear a contact lens. When the boy was 10 year old, the lens of his left eye was removed by phacoemulsification and an intraocular lens was implanted. The intraocular lens functioned well and was tolerated by the boy until he died in an automobile accident at the age of 16 years. A histopathologic study of the eyes, which were obtained post mortem, showed a decreased corneal endothelial cell population, mild focal atrophy of iris structures, and mild lymphocytic infiltration in the implanted eye. Vitreous liquefaction and epiretinal membrane formation occurred in both eyes.

Adolescent↗
PubMed1981

Corneal toxicity with systemic cytarabine.

Three patients with leukemia developed corneal toxicity while receiving high doses (3 g/m2) of systemic cytarabine. Symptoms began five to seven days after initiation of treatment with high doses of systemic cytarabine and consisted of ocular pain, tearing, foreign-body sensation, photophobia, and blurred vision. All three patients developed bilateral conjunctival hyperemia and fine corneal epithelial opacities and refractile microcysts that were more numerous in the central than in the peripheral cornea. The symptoms disappeared without treatment in approximately one week. The corneal changes we observed with high doses of systemic cytarabine resembled descriptions of corneal toxicity from topical cytarabine and were probably secondary to inhibition of DNA synthesis in the corneal epithelium.

Corneal Diseases↗
PubMed1981

A light and electron microscopic study of recurrent granular dystrophy of the cornea.

Light and electron microscopic studies in three cases of recurrent granular dystrophy with corneal epithelial involvement showed intracellular rod and trapezoidal crystalline granules characteristic of granular dystrophy. Small intraepithelial cytoplasmic granules were rimmed by 15-nm particles, while larger deposits were often membrane-bound. The granules were closely associated with tonofilaments. There were ultrastructural similarities to keratohyaline. Extracellular granules were often intermixed with cytoplasmic organelles of disintegrated squamous epithelial cells. There was no evidence of a subepithelial pannus. These findings suggest an epithelial origin of the granular dystrophic deposits in these recurrent cases.

Adult↗
PubMed1981

Neurobehavioral effects of methyl bromide inhalation exposures.

Methyl bromide, a neurotoxic agent with a permissible US exposure limit of 20 ppm, is used primarily as a fumigant by an estimated 75,000 workers in the United States. This project was developed to evaluate the neurobehavioral effects of chronic and subchronic exposure to methyl bromide. One group of rats and rabbits was exposed to 65 ppm of methyl bromide for a total exposure of four 25-h weeks, or 100 h, and rats were exposed to 55 ppm of methyl bromide for a total exposure of 36 30-h weeks, or 1,080 h. Comparable control groups were given similar treatment, but no exposure. Behavioral tests of open field activity and limb coordination were conducted weekly during both phases of the experiment with rats, and eyeblink reflexes were measured weekly in rabbits. Nerve conduction velocity measurements were taken weekly from both rats and rabbits during the 65-ppm four-week exposures and monthly from rats during the 55-ppm 40-week exposures. Exposure to 65 ppm for four weeks significantly reduced eyeblink responses and nerve conduction velocity in rabbits but had no effect on rats. Exposure to 55 ppm of methyl bromide for 36 weeks had no effect on nerve conduction velocity, open-field activity, or coordination in rats.

Animals↗
PubMed1980

Non-Hodgkin's lymphomas in leukemic phase: clinicopathologic correlations.

A leukemic phase occurred in 30 (14 percent) of 214 patients with non-Hodgkin's lymphoma. To determine the significance of peripheral blood involvement in each type of NHL, patients were subdivided according to a modified Rappaport classification. Each histologic subtype presented a homogeneous clinical picture which differed from that seen in other histologic subtypes. Of particular note was the recognition of two distinctive cytologic and clinical subtypes within the category of nodular lymphoma, poorly differentiated lymphocytic lymphoma (NPDL). In one subtype, the predominant cells had cytologic features akin to those of lymphoblasts. In these cases, although the interval to peripheral blood involvement was variable, the median leukemic survival was only two months. In contrast in conventional NPDL the median leukemic survival was 43+ months, and peripheral blood involvement did not appear to exert an independent effect on prognosis. In diffuse large cell lymphomas the median leukemic survival was 0.5 months, with peripheral blood involvement appearing as a terminal event associated with unresponsive disease in multiple sites. The recognition of adult lymphoblastic lymphoma as a clinicopathologic entity with a high risk of leukemic conversion, 100 percent in this study, is also confirmed.

Adolescent↗
PubMed1980

Orbital fine needle aspiration biopsy with B-scan guidance.

In three patients we used B-scan ultrasonography to guide the placement of an aspirating needle, which allowed rapid and accurate cytologic diagnosis of retrobulbar orbital neoplasms. This technique spares the patient the greater costs, inconvenience, and morbidity of more invasive procedures.

Aged↗