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R Healey

Publications and source records attributed to R Healey.

5 recordsLinked to original sources
PubMed2002

Subchondral bone of the human knee joint in aging and osteoarthritis.

OBJECTIVE: Although most research investigating the pathogenesis of osteoarthritis (OA) has focused on cartilage, it has been suggested that the subchondral bone (SCB) plays an important role in the development of OA. The relationships between aging, severity of OA change and the SCB thickness and density in the human knee joint specimens from a wide range of ages were examined. METHODS: One hundred forty knee joints from 72 individuals (25 females, 45 males and 2 unknowns; average age 54.8 years, range 17 to 91 years) were obtained. The surface of the articular cartilage of both the femur and tibia was evaluated for gross morphological changes with a 4-point grading scale. The lateral and medial femoral condyles were cut along a sagittal plane and the tibia along a coronal plane to make bone and cartilage strip specimens. The strips were X-rayed onto mammography film and then scanned into a computer for assessment of SCB thickness and density using image analysis software. RESULTS: Medial tibial SCB thickness was significantly lower among the elderly (age>69 years) than among the young (age<40) or the middle-aged (40 to 69) (P< 0.001 via ANOVA). Lateral tibial SCB thickness also showed the same trend of decreasing thickness with increasing age, but differences between age groups were not statistically significant. Tibial SCB thicknesses were significantly lower in arthritic grades compared to normal grades (P=0.008 in lateral and 0.017 in medial via ANOVA); in contrast, no significant differences between normal and arthritic were found in femoral SCB thicknesses. The arthritic group tended to have lower SCB densities than the normal group, but this was statistically significant in only the lateral femoral condyle. CONCLUSIONS: The results obtained in the present study are not consistent with generally accepted notions of the relationship between subchondral bone thickness or density and OA. Subchondral bone changes are not etiologic for OA but, more likely, are secondary to loss of articular cartilage which precedes the appearance of subchondral sclerosis.

Adolescent↗
PubMed1997

An inherited platelet function defect in a Simmental crossbred herd.

An inherited bleeding disorder, resembling Simmental hereditary thrombopathy (SHT), has been identified in a Simmental crossbred herd. In an affected bull calf, initially evaluated because of excessive bleeding from a vaccination site, the platelet aggregation response to the agonist, adenosine-diphosphate (ADP) was essentially absent and the aggregation response to platelet activating factor (PAF16) was reduced by at least 70%. The initial laboratory assessment of platelet function in the dam and sire yielded results which were within normal limits. The sire was not available for further testing. The dam, also a daughter of this sire, was subsequently shown to have a partially reduced aggregation response to ADP. Of 18 other offspring of the sire evaluated, 6 were also identified as having a partially impaired aggregation response. The maximum aggregation response to ADP and PAF16 in these 6 calves was approximately 50% of the level exhibited by unaffected animals. In contrast, the coagulation profiles were normal for all animals except for a heifer calf which also exhibited a partially impaired aggregation response. The plasma level of the coagulation protein, factor XI, was reduced in this heifer calf which suffered a fatal hemorrhage following dehorning. This report appears to be the 1st to have identified animals putatively heterozygous for SHT on the basis of the in vitro platelet aggregation response to ADP.

Adenosine Diphosphate↗
PubMedDate not supplied

Childhood leukemia in Woburn, Massachusetts.

Possible associations between environmental hazards and the occurrence of childhood leukemia were investigated in Woburn, MA, for the period 1969-79. Residents of Woburn were concerned over what they perceived to be a large number of childhood leukemia cases; at the same time there was extensive publicity about uncontrolled hazardous waste sites in Woburn, which resulted in its being placed on the Superfund list. Many believed that the elevated rate of childhood leukemia was related to these sites or to two city water wells that had been closed in 1979 when they were found to be contaminated by organic chemicals. An occurrence was defined as childhood leukemia when it was diagnosed in a Woburn resident less than 20 years old between 1969 and 1979 and confirmed by review of hospital and pathology records. This investigation confirmed an increase in incidence which was distributed uniformly over the 11-year period. Six of the persons with leukemia were located close to each other in one census tract, 7.5 times the expected number. Parents of the children and of two matched control groups were interviewed about medical history, mother's pregnancy history, school history, and environmental exposures. There were no significant differences between the leukemia victims and persons in the control groups. No leukemia sufferer had contact with a hazardous waste site. While the contaminants of Wells G and H, which had been closed, are not known leukemogens, it is not possible to rule out exposure to this water as a factor, particularly in the eastern Woburn residents.

Adolescent↗