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Biomedical subjects

H M Abdel-Kader

Publications and source records attributed to H M Abdel-Kader.

16 recordsLinked to original sources
PubMed1999

The potential of digital dental radiography in recording the adductor sesamoid and the MP3 stages.

The current study was undertaken to evaluate the reliability of using a recent advance in clinical radiographic technique, digital dental radiography, in recording two growth indicators: the adductor sesamoid and MP3 stages. With an exposure time five times less than that used in the conventional approach, this method shows greatest flexibility in providing a high quality digitized radiographic images of the two growth indicators under investigation. Refereed Paper

Adolescent↗
PubMed1987

Long-term cotton dust exposure in the textile industry.

A three-year survey was conducted in six cotton-yarn manufacturing mills and one mill processing synthetic polyester fibers as part of a longitudinal epidemiologic investigation of the health experience of workers employed in the textile industry. A total of 1324 elutriated and total dust samples were collected during the three years of the study. The results indicate that the average elutriated dust concentrations in the surveyed mills were generally at or below the current OSHA standard and they ranged from 0.069 to 0.396 mg/m3, 0.089 to 0.391 mg/m3, and 0.106 to 0.210 mg/m3 for the first, second and third year surveys, respectively. Introduction of modern automated yarn processing equipment and elimination of some of the classic processes were associated with a decreasing trend in airborne dust concentrations in these mills.

Dust↗
PubMed1986

Clinical crown length and reduction in overjet, overbite, and dental height with orthodontic treatment.

To evaluate the clinical crown length relative to fixed-appliance orthodontic treatment of excessive overjet and deep overbite and to correlate such changes to the vertical dental height, the following measurements were undertaken for 12 females and 8 males, between the ages of 16 and 20 years, on three separate occasions--2 days before banding, 2 days after debanding, and 12 months after debanding: (1) overjet, overbite and dental height measured from right lateral cephalometric x-ray films; (2) clinical crown length, measured from study models, of 400 teeth divided into four groups--maxillary incisors and canines (120 teeth), maxillary second premolars and first molars (80 teeth), mandibular incisors and canines (120 teeth) and mandibular second premolars and first molars (80 teeth); and (3) gingival condition by means of the gingival index of Löe and Silness. Fixed edgewise orthodontic appliances were used and the four first premolars were extracted. From the results of the investigation, the following conclusions were evident: after a 12-month follow-up observation period, the achieved reduction in overjet, overbite, and dental height showed relapses of 9%, 11%, and 29%, successively; only 7% of the 400 teeth examined showed reductions in clinical crown length. This change was probably the result of gingival hyperplasia. The gingival condition greatly improved by approximately 64% after 12 months of debanding, accompanied by 25% to 50% relapse in the amount of change in clinical crown length (noted 2 days after debanding); and the intrusive tooth movement during orthodontic correction of deep overbite was the result of vertical movement of the tooth, with its investing tissues and soft-tissue attachment, into the jaws.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1984

Isomeric composition of airborne TDI in the polyurethane foam industry.

The isomeric composition of airborne toluene diisocyanate has been determined in two plants producing slab stock flexible polyurethane foam. The high performance liquid chromatographic technique used for analysis of the collected samples was optimized for the quantitative and qualitative determination of 2,4 and 2,6-TDI. The data indicates that there is a very large increase in the amount of airborne 2,6-TDI relative to the 2,4 isomer, as compared to the starting material used in the process. The magnitude of the increase was dependent on the stage of production. These results are consistent with the hypothesis of increased offgassing of 2,6-TDI, due to its lower reactivity.

Air Pollutants, Occupational↗
PubMed1984

Role of histamine in the aetiology of byssinosis. I Blood histamine concentrations in workers exposed to cotton and flax dusts.

The formation or the accumulation, or both, of histamine in the lungs may be potentiated by agent(s) present in cotton dust at higher level(s) than in flax dust and negligible in cottonseed dust. It has been suggested that such potentiation may be due to the activation of the ability of the lung to produce histamine and/or produce or recruit mast cells; this may present an acceptable explanation of the mechanism by which the propagation of the chronic effect of the dust proceeds in cotton and flax workers. Histamine accumulated in the lung over the weekend is released on exposure to dust causing the symptoms of byssinosis. The difference in the rate of histamine metabolism relative to the rate of histamine formation in byssinotic subjects leads to a more prolonged histamine accumulation than in symptom free subjects, with the consequent appearance of the symptoms of byssinosis. Continuous exposure to dust, without weekend interruption, leads to equivalent rates of histamine formation and metabolism with non-considerable histamine accumulation in the lungs and consequent absence of the symptoms of byssinosis.

Bronchitis↗
PubMed1984

Role of histamine in the aetiology of byssinosis. II. Lung histamine concentrations in guinea pigs chronically exposed to cotton and flax dusts.

Data presented in this study support the finding that cotton and flax dusts contain agents which potentiate the formation or accumulation of histamine or both in the lungs of guinea pigs exposed to dust, and that such agents are present at much higher levels in cotton dust than in flax dust. The potentiating effect may be through the recruitment of mast cells into the lung. Both cotton and flax dusts contain methylating enzyme inhibitory agents, whereas cotton dust also contains agents that inhibit histaminase activity; flax dust contains agents potentiating histamine activity. These agents working together result in the accumulation or depletion of histamine observed in the different groups of animals exposed to either cotton or flax dust in this study.

Animals↗