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Biomedical subjects

W C Pitchford

Publications and source records attributed to W C Pitchford.

7 recordsLinked to original sources
PubMed1988

Anteroposterior radiographic view of the knee. An unreliable indicator of bone damage.

The clinician and/or radiologist uses standard radiographic views to assess bony changes in the joints of patients with both potential and established arthritis. Using AP (standing) views, we recorded the number of osteophytes and/or subchondral cysts seen on both nonarthritic and arthritic tibial tables and their respective plateaus. These data were compared with the number of osteophytes and/or subchondral cysts observed on "en face" views taken of the same tibial tables after they were resected from the knee joints. Not all of the osteophytes or subchondral cysts present in these tibial tables were detected with the AP view. Narrow osteophytes and those located at extreme anterior or posterior positions on a plateau were missed. Single cysts scattered across a plateau were also not seen. We found that the standard AP view gave an inaccurate measure of the amount of bone damage actually present in the tibial tables of arthritic knees.

Adult↗
PubMed1988

The erosive front: a topographic study of the junction between the pannus and the subchondral plate in the macerated rheumatoid metacarpal head.

The junction between cellular pannus and cartilage/bone was identified grossly on rheumatoid metacarpal heads. Its topography was displayed by scanning electron microscopy using macerated samples. A uniform pattern of resorption bays, typical of osteoclastic activity, was seen spreading over the surfaces of both calcified cartilage and subchondral bone. The contact area between pannus and cartilage/bone was found to represent an erosive front. Morphologic evidence suggested that osteoclasts were primarily responsible for the destructive process.

Adult↗
PubMed1981

A comparative study of platelet reactivity in arthritis.

We utilized a standardized in vitro method which employs transmission electron microscopy to monitor the degree of surface activation (cytoplasmic spreading) and amount of aggregation displayed by platelet populations from 314 patients with one of five distinct rheumatic diseases and from 72 normal subjects. The percentage of patients in each group whose platelet populations were hyperactive was as follows: polymyalgia rheumatica, 75 percent; scleroderma, 65 percent; primary gout, 61 percent; rheumatoid arthritis, 57 percent; and degenerative joint disease, 40 percent. Pair-wise contrasts performed after an analysis of variance suggest the following differences and similarities: (1) the mean differential platelet count of the normal subjects differed from that in each disease state; (2) the platelet responsivity in patients with degenerative joint disease most closely resembled that in normal subjects; (3) the platelet response in polymyalgia rheumatica plus temporal arteritis was the most abnormal; and (4) platelet response in scleroderma, rheumatoid arthritis, and gout closely resembled each other. The increased platelet response in vitro may reflect the in vivo presence of disease-related "risk factors" (hyperuricemia, immune complexes, and atherosclerosis). Those patients with "triggered" platelet populations may be appropriate candidates for antiplatelet therapy.

Adult↗
PubMed1980

A scanning electron microscopy study of the effect of proteinase inhibitors on mouse uterine morphology.

The luminal uterine surface of mice was examined by scanning electron microscopy after a 24 h treatment with basic pancreatic trypsin inhibitor (BPTI) or L-1-tosylamido-2-phenylethyl chloromethyl ketone (TPCK) administered as a single injection or from a slow release capsule on Day 2 p.c. in doses known to impair fertility. The effect of BPTI was slight, some swelling of cells and loss of microvilli. TPCK, on the other hand, caused disruption of the epithelium through swelling and sloughing of cells, sporadic loss of microvilli, and the presence of red blood cells.

Animals↗
PubMedDate not supplied

Examination of compact bone microdamage using back-scattered electron microscopy.

A new staining technique using heavy metals (lead-uranyl acetate) has been developed to allow visualization of bone microdamage using both light microscopy and scanning electron microscopy operated in its back-scattered mode (BSE). At the light microscopic level, the number of microcracks counted in sequential sections of human ribs is the same for both the traditional basic fuchsin method of differentially staining microcracks and the new lead-uranyl acetate procedure. With BSE study, however, the number of microcracks observed is significantly reduced in all samples, because of the reduction of projection effect error associated with surface based imaging techniques. Application of the lead-uranyl acetate staining technique to ex vivo-loaded crack propagation specimens showed an extensive ultrastructurally disrupted region associated with the crack path through bone, consistent with the damage process zone around cracks in toughened composite materials.

Adult↗