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H M Dick

Publications and source records attributed to H M Dick.

At least 19 recordsLinked to original sources
PubMed1992

The microstructural tensile properties and biochemical composition of the bovine distal femoral growth plate.

The tensile properties of distal femoral growth plates from 12-month-old cows were determined on uniformly prepared straight bone-growth plate-bone specimens (7 x 7 mm2 in cross-section) from predetermined anatomical sites on the physis. Each specimen was distracted to failure using a computer-controlled servo-hydraulic testing machine at a strain rate of 0.004 s-1. It was found that the exponential constitutive law, using finite deformation formulation for strain, provides an excellent description of the stress-strain behavior of all the specimens up to the point of failure. The ultimate stress and both tangent moduli (i.e., the toe region tangent modulus and the tangent modulus calculated at 75% of ultimate strain) varied with anatomical site. The anterior region was the strongest, followed by the posterior/lateral. The anterior and posterior/lateral regions were also the stiffest, whereas the posterior/medial and center regions were the weakest and most compliant. The bone-growth plate-bone specimen exhibited a low ultimate strain (13.8% +/- 6%) that did not vary significantly throughout the growth plate. This result suggests that disruption of the physis may occur in vivo even at the lower distractions currently recommended for the clinical chondrodiatasis procedure for leg lengthening. The biochemical composition of the growth plate in the anatomical regions correlated well with the tensile properties. There was a greater collagen content in the regions that were the stiffest and strongest. The gross morphology of the growth plate of the bovine distal femur is also described in this study. There is a regular pattern to the undulations of the physis at several dimensional levels. Histologic findings showed that orientation of the hypertrophic cell columns and transphyseal septa are aligned nearly parallel to the longitudinal axis of the diaphyseal shaft. This column orientation is not affected by the undulation of the primary contour of the physis, which at certain locations may be inclined as much as 60 degrees relative to the diaphyseal axis. The orientation of the hypertrophic cell columns appears to be one of the dominant microstructural features influencing the tensile behavior of the bone-growth plate-bone specimens.

Animals↗
PubMed1992

Heterogeneous in vivo MR images of soft tissue tumors: guide to gross specimen sampling.

Twelve soft tissue tumors preoperatively studied with magnetic resonance (MR) imaging contained areas of inhomogeneous intralesional signal intensity. The pathologist's selection of biopsy sites from gross specimens was based on specific MR images selected by a radiologist and depended on close cooperation between the radiologist and pathologist. The histopathology so sampled, further depended on the lesion's size, careful gross specimen orientation, discrete sampling, and a specially developed Grid Analysis technique. Our initial experience indicates that (1) histology may vary within different and often neighboring sites of a single soft tissue lesion; (2) that such variability is common in soft tissue tumors; (3) that histological variability within different sites of a single lesion influences signal heterogeneity; and (4) that although differing MR signal intensities per se are not tissue specific, MR may enhance the histopathological accuracy of pathologists who can be directed to particular gross specimen sites by magnetic resonance images. To our knowledge such a specific, detailed effort has not been made.

Adult↗
PubMed1991

Magnetic resonance grid analysis of soft tissue lesions.

Soft tissue tumors of seven patients were imaged with magnetic resonance imaging (MRI) prior to operative resection. In four cases, gross surgical specimen biopsy sites were broadly selected from areas of diverse signal intensity. A subsequently developed "grid analysis" technique, used in three additional patients, better localized differing zonal intensities within individual gross specimens. Further investigation of this technique is warranted, since MR images, when analyzed by means of a detailed grid technique, appear to enhance histologic diagnostic accuracy. Examination of larger segments of inhomogeneous soft tissue tumors is facilitated, while pathologists' sampling time is diminished.

Adult↗
PubMed1991

Articular fractures of the hand. Part I: Guidelines for assessment.

Articular fractures of the hand represent a particularly challenging group of injuries owing to the frequent comminution of the fractured bone, disruption of a finely balanced soft-tissue sleeve, and a propensity for scarring and contractures. Assessment of these fractures must include accurate delineation of the injury, using roentgenographic and computed tomographic imaging to define articular congruency, and a precise examination to determine stability.

Finger Injuries↗
PubMed1991

Articular fractures of the hand. Part II: Guidelines for management.

Articular fractures of the hand represent a particularly challenging group of injuries owing to the frequent comminution of the fractured bone, disruption of a finely balanced soft-tissue sleeve, and a propensity for scarring and contractures. Treatment must restore anatomic joint alignment and stability and should incorporate a carefully guided early rehabilitation program. Part I of this article, which appeared in the January issue, covered techniques for the evaluation of these complex injuries.

Finger Injuries↗
PubMed1990

Limited open surgical approach for external fixation of distal radius fractures.

In an effort to reduce treatment-related complications, a surgical procedure has been developed for the insertion and application of an external fixation device in the management of unstable fractures of the distal radius. Clinical experience with this device has demonstrated its effectiveness in reducing complications associated with pin insertion. The surgical technique is presented together with a case example. Results of laboratory tests corroborate our clinical experience and demonstrate the effectiveness of this technique in minimizing complications. Clinical results in 66 cases document the efficacy and safety of this technique.

Adult↗
PubMed1989

Malignant bone tumors of the hand.

Primary malignant tumors of the bone are among the most rare tissue type and more rare in the acral parts. The authors recommend the use of the Musculoskeletal Tumor Society Grading System for standardization of these rare tumors in the hand.

Bone Neoplasms↗
PubMed1979

A study of HLA antigen distribution in families with atopic dermatitis.

Seventeen children presenting with atopic dermatitis were HLA typed together with their parents and siblings. A total of 89 individuals was studied. No close link between HLA antigen distribution and clinical expression of atopy was demonstrated, and 14 HLA identical but disease-free siblings were identified. An increase in the A1 B8 haplotype was observed in the families as a whole by comparison with a large control series.

Adult↗
PubMed1979

Cold lymphocytotoxins in connective tissue disorders.

Sixty-eight patients with various connective tissue disorders, 5 relatives of patients and 26 members of staff from the Centre for Rheumatic Diseases were studied for the presence in their sera of cold lymphocytotoxic antibodies. Antibodies were found in 71 percent of patients with systemic lupus erythematosus, 27 per cent of patients with rheumatoid arthritis, 0 per cent of the small group of relatives and 3.8 per cent of the controls. Absorption studies did not show T or B specificity of the antibodies. The control group, working in close proximity to the patients or their sera did not show any increased incidence of antibodies as compared to control groups of other studies. Red blood cell anti I or HI was found in the sera of 28 per cent of those with cold lymphocytotoxic antibodies. No correlation was found between the presence of the antibodies and number of blood transfusions or pregnancies, increasing age, R3 titre or antinuclear factor.

Adult↗
PubMed1978

HLA antigens and IgG allotypes on the Island of Barra (Outer Hebrides).

The distribution of HLA antigens and IgG allotypes in a group of nearly 200 adults on the Island of Barra, shows some unusual features. The sample tested included only people age 65 and over. Marked differences in the frequency of some HLA antigens were noted, compared to those previously determined for the northern island of Lewis and Harris, with increase in the frequency of HLA-A5 and B7. The latter antigen was present in over 40% of the group, compared with a frequency of 27% in the Northern islands. The high frequencies of HLA-A2, the Aw19 group and B12 previously noted in Scottish populations were also present. The IgG allotype, Gm (f;b4) was markedly increased, being present in 67% of the group, in comparison with frequencies of 40--45% in previous Scottish studies. These results either suggest a sampling phenomenon, or may be an indicator of selective forces related to immunological mechanisms or the age distribution of the population studied.

Aged↗
PubMed1978

Influence of HLA matching and blood transfusion on renal allograft survival.

One hundred and seven consecutive cadaver kidney transplants have been followed for up to 6 years. The beneficial effect of HLA matching, shown in previous studies, has been confirmed. The 2-year failure rate from rejection was 29% for grafts with less than two incompatibilities, in comparison with a figure of 52% where there were two or more incompatibilities. In contrast to some reports, the presence of HLA antibodies did not have an adverse effect on the survival of first grafts. Patients not transfused prior to transplantation had a much higher 1-year graft failure rate (72%) than those given either frozen-thawed red cells (29%) or whole blood (23%). This apparently beneficial effect of blood transfusion was no greater in patients transfused with more than five units compared with those given less than five units. We believe that blood transfusion has an important influence on the outcome of renal transplantation.

Adolescent↗