Biomedical subjects

A Azar

Publications and source records attributed to A Azar.

At least 19 recordsLinked to original sources

PubMed1989

Ultraviolet light exposure and risk of posterior subcapsular cataracts.

Posterior subcapsular (PSC) cataracts are a visually disabling form of cataract and account for 40% of surgical cases. Although PSC opacities may occur following intraocular inflammation, trauma, or use of steroids, the cause is often unknown. A case-control study was undertaken to investigate the role of exposure to ultraviolet light in the B range (UV-B) and other potential risk factors for the development of PSC cataracts. Surgical PSC cataract cases from a large rural ophthalmic practice on the lower eastern shore of Maryland were matched with phakic controls without PSC cataract changes from the same geographic area by age, sex, and referral pattern. All patients with PSC opacities who underwent cataract surgery in a 12-month period were chosen. One hundred sixty-eight cases and 168 controls were interviewed regarding sunlight exposure, drug use, occupational history, history of diabetes, hypertension, and other diseases. Matched-pairs analyses indicated that a history of relatively high exposure to UV-B was associated with increased risk of PSC cataracts. The association of PSC cataracts with steroid use and diabetes was reconfirmed. Subjects with blue eyes and less than high school education were also at increased risk for PSC cataracts. Smoking and hypertension were not found to be PSC cataract risk factors. These data suggest that UV-B exposure may be an important risk factor for PSC cataracts.

Adult↗

PubMed1978

Sympathetic ophthalmia. A long-term follow-up.

Seventeen cases of sympathetic ophthalmia have been followed up for as long as 23 years (average 10.6 years). Sixty-five percent of those patients treated with corticosteroids retained a visual acuity of 20/60 or better. Complications were frequent and included secondary glaucoma, cataract, exudative retinal detachment, and choroidal scarring. Uneventful cataract extraction was difficult to manage, requiring frequent changes in the steroid dosage, and in one patient two glaucoma procedures. The duration of steroid therapy was quite variable and ranged from a few months to six years or longer. Relapses were common and several occurred many years after the initial episode had resolved. If the histopathologic picture were moderate or severe, the clinical course most often would be difficult and protracted.

Adolescent↗

PubMed1976

Experiments on the effect of carbon monoxide on aminolevulinic acid dehydrase (ALAD).

The inverse relationship between blood lead concentration and aminolevulinic acid dehydrase (ALAD) is well known. Recently, it has been suggested that a similar relationship exists between carboxyhemoglobin (COHb) and ALAD activity. This study was undertaken to examine more closely the possible effect of carbon monoxide on ALAD. Blood from 19 human volunteers was analyzed for both carboxyhemoglobin and ALAD activity. Smokers had significantly lower concentrations of ALAD than nonsmokers and a rise in carboxyhemoglobin concentration was assocaited with a fall in ALAD activity. The in vitro bubbling of carbon monoxide into human blood did not significantly effect ALAD activity. Four groups of rats (10 per group) wre exposed to carbon monoxide or dietary lead acetate according to the following design: (I) Control--no Pb or CO; (II) 500 ppm Pb acetate in diet; (III) 250 ppm CO four hours/day X 5 days/week X 4 weeks; (IV) Both Pb and CO. Analysis of the rat data showed a significant depression of ALAD by lead. The activity of ALAD in the rats exposed to CO was significantly increased suggesting the possibility of an adaptive phenomenon.

Aminolevulinic Acid↗

PubMed1976

The effect of myocardial infarction on the cardiac sensitization potential of certain halocarbons.

We have previously shown that many halocarbons and hydrocarbons are capable of producing cardiac sensitization. Briefly, the test method involved exposure of healthy, unanesthetized, beagle dogs to various inspired levels of sensitizing agent, followed by an intravenous dose (8 mug/kg) of epinephrine. Along, this epinephrine dose produces only mild ECG alterations, but, at threshold levels of a sensitizing agent, may induce a serious cardiac arrhythmia and sometimes death. Using the same test protocol, dogs with experimentally-induced myocardial infarctions were used to determine whether this type of heart condition might significantly lower the threshold for cardiac sensitization. Test results on three halocarbons showed no greater potential for cardiac sensitization among dogs having recovered from myocardial infarction as compared to normal, healthy animals.

Animals↗

PubMed1976

[Difluocortolone valerate in dermatology].

The investigational preparation Nerisona Cream (diflucortolone valerate 0.1%, investigational no. SH K 183 MB) was used in 47 patients with various inflammatory or pruriginous dermatoses. Either very good or good results were achieved in 89.3% of the cases. Nearly all the patients thought highly of the cosmetic properties of the preparation. No side effects were observed.

Administration, Topical↗

PubMed1975

Recovery of blood lead concentration and of red cell 8-aminolevulinic acid dehydrase activity in dogs following return to normal diets after 75 weeks of lead feeding.

Blood lead concentration and red cell delta-aminolevulinic acid dehydrase (ALAD) activity were determined at intervals for eight months after symptom-free dogs, which had received 100 ppm or 500-1000 ppm of lead, by weight, in their diets for 75 1/2 weeks, were returned to a lead-free diet. Statistical treatment of the data disclosed a linear relationship between the logarithm of blood lead concentration or of ALAD activity and the logarithm of time (experimental week) during the recovery period. The calculated regressions predict that recovery of ALAD will occur before recovery of the blood lead concentration. Predicted recovery times depend on the levels selected as those which must be attained for recovery to be complete, as well as on the dosage of lead. The logarithm of the slope of the ALAD recovery regression of the individual dog has a linear relation to the percentage reduction in ALAD due to the lead, the regression accounting for 92% of the variance in the recovery rates. The slope of the blood lead recovery regression has a linear relation to the increase in blood lead for the dogs which received the low lead diet, but not for those which received the high lead diet.

Animals↗

PubMed1975

An epidemiologic approach to community air lead exposure using personal air samplers.

Accurate information on the relationship between blood lead and air lead is essential to any consideration of the possible effect of air lead on the body burden. Past studies of occupationally exposed workers have established that such a relationship exists at high levels of air lead exposure. No such information has been available for subjects exposed to the low air lead levels representative of present-day community exposure. Past studies in this area have suffered from inadequate information on actual lead exposure at the air lead levels of concern. Researchers have has to rely on air lead data obtained from stationary samp;ing stations. Because wide variations can exist betwween locations within a city such information could not be assumed to represent the exposure of any individual subject. At lbest they can be considered only approximations of actual exposures. The Naational Research Council recognized the deficiencies of past studies in their report "Airborne lead in perspective" and recommended that "more precise studies are needed of the relation between atmospheric lead in the urban environment and the concentration of lead in the blood, perphaps by the use of personal monitors". This paper describes the study which was undertaken to evaluate the effect of air lead exposure as measured with personal air sampling devices on indices of lead absorption such as blood lead, urine lead, DALA and ALAD activity...

Absorption↗

PubMed1975