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Biomedical subjects

M Hannan

Publications and source records attributed to M Hannan.

23 records · Page 2Linked to original sources
PubMed1987

Lead poisoning in automobile radiator mechanics.

Exposure to lead occurs during automobile radiator repair when soldered joints are heated, but this relatively common hazard has received little public recognition. We therefore studied lead exposure among automobile radiator mechanics in the Boston area. Twenty-seven shops were surveyed, and most were found to be small and poorly ventilated. Seventy-five workers were interviewed and tested for blood lead and free erythrocyte protoporphyrin levels. Fifty-six of the 75 actually repaired radiators, and they had a mean blood lead level of 37.1 micrograms per deciliter (range, 16 to 73). Thirty-nine percent of these mechanics had levels higher than 40 micrograms per deciliter; hematologic, neurologic, and renal effects are known to develop at or above this blood lead level. Multiple regression analysis showed that the number of radiator repair work stations (an index of exposure) was the variable most significantly associated with increased blood lead levels. We conclude that excessive exposure to lead occurs frequently among radiator repair workers and should be prevented by improved ventilation, engineering controls, and the use of respirators (if indicated) while working.

Adult↗
PubMedDate not supplied

Critically sized osteo-periosteal femoral defects: a dog model.

A 21-mm defect was created in 1 femoral diaphysis each of 15 dogs. Periosteum as well as a cylinder of bone was removed, and the defect was stabilized with a bone plate. Twelve of the defects were filled with an equal volume of autogenous cancellous bone harvested from the ipsilateral ilium. Three defects were left untreated. Cranial to caudal radiographs were taken postoperatively and every 4 weeks for 16 weeks. The radiographs were evaluated for healing using two ordinal scales. At 16 weeks, the dogs were euthanized and the femurs harvested for biomechanical testing and histologic evaluation. Both operated and contralateral not operated femurs were mechanically tested to failure in torsion, and load at failure and stiffness were calculated. All dogs tolerated the procedure well, and were using the operated limb within 1 or 2 days postoperatively. There were no complications noted during the 16 weeks of the study. Unfilled defects did not heal and became atrophic nonunions. The defects filled with autogenous cancellous bone healed in a consistent pattern of consolidation, incorporation, and remodeling, with uniform increases of both ordinal scales used. The femoral cortex opposite the bone plate demonstrated most mature remodeling, evident both radiographically as well as histologically. Unoperated femurs failed at 13.61 +/- 3.88 N-m and grafted femurs failed at 2.96 +/- 1.3 N-m, which was 23% of the measurement of the unoperated femur. Relative stiffness of the unoperated femurs was 5974 +/- 4316 N-m2/radian, and grafted femurs had a relative stiffness of 642 +/- 561 N-m2/radian, which was 10.4% of the measurement of unoperated femur. This model proved to be a critically sized defect, which when left unfilled resulted in an atrophic nonunion, and when filled with cancellous bone resulted in a consistent healing pattern.

Animals↗
PubMedDate not supplied

Von Willebrand disease: a nursing perspective.

Von Willebrand disease, caused by a deficiency or abnormality of von Willebrand factor, is the most common hereditary bleeding disorder, occurring in approximately 1% of the population. This article is intended to raise the level of awareness in the health care community and define the nurse's role in recognizing the clinical presentation of this underdiagnosed bleeding disorder.

Adult↗