Biomedical subjects

E F DiCarlo

Publications and source records attributed to E F DiCarlo.

29 records · Page 2Linked to original sources

PubMed1992

Cellular repopulation of deep-frozen meniscal autografts: an experimental study in the dog.

This study evaluated the cellular repopulation of deep-frozen meniscal autografts. Medial menisci of adult dogs were excised, deep-frozen in liquid nitrogen (-196 degrees C) for 10 min, and orthotopically reimplanted into the joint. Deep-freezing was found to effectively kill all the cells within the meniscus as determined by the absence of Na(2)35SO4 incorporation. Following orthotopic replacement within the knee joint, menisci were repopulated with cells that seemed to originate from the adjacent synovium. These cells migrated over the surface of the meniscus and began to invade the deeper layers of the tissue. However, even after 6 months, the central core of the meniscus remained acellular. While the new cells appeared to modulate into cells that are similar in appearance to meniscal fibrochondrocytes, the exact phenotypic expression of these newly differentiated cells has yet to be determined. Histological alterations, as manifested by a loss of normal orientation of the collagen architecture of the superficial layers of the meniscus; was evident at 6 months and suggests that a remodeling phenomenon may be associated with the cellular repopulation. While biomaterial studies have not been carried out on these specimens, the morphologic alterations observed in the collagen orientation would suggest a possible alteration in the material properties of the repopulated meniscus. The clinical implication of this study is that the structural remodeling associated with the cellular repopulation of deep-frozen meniscal allografts may make the transplanted meniscus more susceptible to injury.

Animals↗

PubMed1992

Size of metallic and polyethylene debris particles in failed cemented total hip replacements.

Reports of differing failure rates of total hip prostheses made of various metals prompted us to measure the size of metallic and polyethylene particulate debris around failed cemented arthroplasties. We used an isolation method, in which metallic debris was extracted from the tissues, and a non-isolation method of routine preparation for light and electron microscopy. Specimens were taken from 30 cases in which the femoral component was of titanium alloy (10), cobalt-chrome alloy (10), or stainless steel (10). The mean size of metallic particles with the isolation method was 0.8 to 1.0 microns by 1.5 to 1.8 microns. The non-isolation method gave a significantly smaller mean size of 0.3 to 0.4 microns by 0.6 to 0.7 microns. For each technique the particle sizes of the three metals were similar. The mean size of polyethylene particles was 2 to 4 microns by 8 to 13 microns. They were larger in tissue retrieved from failed titanium-alloy implants than from cobalt-chrome and stainless-steel implants. Our results suggest that factors other than the size of the metal particles, such as the constituents of the alloy, and the amount and speed of generation of debris, may be more important in the failure of hip replacements.

Chromium Alloys↗

PubMed1991

Longitudinal splitting of the peroneus brevis tendon: an anatomic and histologic study of cadaveric material.

Gross and microscopic examinations of 21 split and 10 intact cadaveric peroneus brevis tendons were performed in an effort to determine the pathogenesis of longitudinal splitting of this tendon. The split regions were centered over the posterior margin of the distal fibula and were characterized by splaying of the collagen bundles with accompanying proliferation of blood vessels and fibrovascular connective tissue. Inflammatory infiltrates were not present. Regions of the tendons that were not altered had normal cellularity and orientation of the collagen. The findings of this study suggest that the splitting of the tendon develops through a mechanical mechanism.

Adult↗

PubMed1990

Subchondral avascular necrosis: a common cause of arthritis.

(1) Subchondral avascular necrosis is an important cause of joint pain and disability and accounts for upwards of 20% of total hip replacements done in our hospital. (2) Early diagnosis may be made with the aid of magnetic resonance imaging and radioactive isotope studies. (3) Although the signs and symptoms are similar to those of osteoarthritis, there are significant differences--namely, (a) a history of sudden onset of pain, present in more than half the patients; (b) a younger age group; (c) a shorter duration of symptoms at time of surgery; (d) clinically the limiting factor is pain rather than actual joint deformity to account for restriction of movement; (e) a high incidence of multiple sites of involvement. (4) The disease is commonly associated with steroid treatment or alcohol abuse. Although many other causes are recognised, they are rare in Western urban practice. (5) Patients with stage I-II subchondral avascular necrosis, especially of the knee, are better treated conservatively. (6) Surgical treatment gives less satisfactory results than the treatment of osteoarthritis by similar modalities.

Arthritis↗

PubMed1990

The tissue diagnosis of metabolic bone disease. Role of histomorphometry.

Those aspects of bone histology and histomorphometry that need to be understood by clinicians to put histomorphometry into proper perspective are presented. An increasingly important component of the histologic diagnosis of the metabolic diseases of bone is the quantification of the various histologic features as seen in undecalcified bone biopsies. This article is intended to review some of the histologic features of the metabolic diseases of bone and their corresponding histomorphometric parameters as they are used in diagnosis. The methods of obtaining both direct and derived values as well as the reporting of the results are presented in detail.

Biopsy↗

PubMed1988

Pigmented villonodular synovitis. Diagnosis and differential diagnosis.

PVNS is a proliferative disorder that can affect joints, tendons and bursae. Its etiology is unknown. The most widely accepted theories attribute this disorder to a chronic inflammatory response or a benign neoplasm of fibrohistiocytic origin. On gross specimens, the synovial changes are characterized by villous and/or nodular hyperplasia. This disorder occurs most frequently in the third or fourth decades of life and has no sex predilection. As a joint problem, it favors the knee and hip. As a tendon abnormality, it favors the digits. Plain film findings include 1) soft tissue swelling, 2) increased density of the synovium secondary to hemosiderin deposition, 3) multiple subchondral cysts, and 4) extrinsic cortical pressure erosions. Cartilage space narrowing, if present, is gradual and occurs later than the other plain film findings. Arthrography can demonstrate the nodular synovial changes and determine if the process is diffuse or focal. MRI can, in some cases, reveal areas of decreased signal within the hyperplastic synovium reflecting the deposition of hemosiderin. The major roentgen differential diagnoses of articular PVNS include uncalcified synovial chondromatosis, tuberculous arthritis, and hemophilic arthropathy.

Bone Cysts↗

PubMed1988

Pathologic studies of total joint replacement.

Articular endoprostheses are, in effect, foreign bodies designed to re-establish functioning articulations and are, therefore, capable of eliciting a local or systemic response to their presence. This article discusses the body's reactions to foreign bodies in general, and to endoprostheses in particular, and attempts to place those reactions into perspective regarding survival and failure of articular endoprostheses. The effects of size, shape, and composition of the materials used in the prosthetic components, and the mechanical factors acting on them to produce debris, are presented.

Bone and Bones↗

PubMed1987

Myopathy complicating the acquired immune deficiency syndrome.

A case of Acquired Immunodeficiency Syndrome complicated by a severe myopathy is reported. All efforts aimed at documenting an infectious etiology for the myopathy were negative. The relationship of myopathy to AIDS is discussed.

Acquired Immunodeficiency Syndrome↗

PubMed1986

The purely epithelioid malignant peripheral nerve sheath tumor.

The purely epithelioid malignant peripheral nerve sheath tumor (PNST) is a rare form of PNT possibly first described by McCormack et al. in 1954. This tumor type is distinguishable from the glandular PNT and PNT with differentiated neuroepithelium (medulloepithelioma and neuroepithelioma) and differs from the ordinary epithelioid PNT because of the absence of a spindle cell component typical of malignant PNSTs. The two examples of purely epithelioid malignant PNT we describe arose in the popliteal fossa from the sciatic and tibial nerves of men with no definite evidence of von Recklinghausen's neurofibromatosis. Both tumors were partly mucinous, and so closely mimicked carcinoma and a few non-neurogenic myxoid sarcomas histologically that their final classification depended upon proof of a neural origin.

Adult↗

PubMed1985

Diagnostic pathology in the acquired immunodeficiency syndrome. Surgical pathology and cytology experience with 67 patients.

We report the pathologic findings in specimens submitted for histologic and cytologic evaluation from 67 patients with the acquired immunodeficiency syndrome. A wide variety of opportunistic pathogens were identified in 41 patients. Mycobacterium avium-intracellulare evoked only a mild host response: granulomas, if present, were poorly formed. Biopsy specimens showing cytomegalovirus gastroenteritis required sections at multiple levels to demonstrate inclusions. Combined histologic and cytologic evaluation can increase the diagnostic yield in pulmonary and esophageal infections. Kaposi's sarcoma was found in biopsy specimens from 29 patients. Early lesions were often extremely subtle, yet distinct from, benign vascular proliferations in involuted lymph nodes. Malignant lymphoma was diagnosed in ten homosexual men who were suspected of having the acquired immunodeficiency syndrome. The lymphomas were characterized by B-cell origin, a diffuse pattern, frequent extranodal presentations, and an aggressive clinical course with prominent central nervous system involvement.

Acquired Immunodeficiency Syndrome↗

PubMed1979

Cage size and exercise affects infarct size in rat after coronary artery cauterization.

Left coronary occlusion in the rat was performed by cornary artery cauterization. A small amount of myocardial damage at the site of occlusion was noted, and myocardial infarction occurred in the distal distribution of the obstructed coronary. The effects of cage size and level of physical activity on estimated infarct size (as measured by creatine kinase depletion) 48 h after occlusion were determined. Isolation in small cages and moderate treadmill exercise resulted in an approximate doubling of the amount of infarction when compared to grouping of rats in large cages. Mild exercise did not increase infarct size. Total urinary catecholamines in normal rats placed in small cages for 48 h were elevated when compared to unconfined rats in larger cages. Cornary artery occlusion by cauterization is an easily performed technique. Cage size and level of activity (and their effects on sympathoadrenal function) are important independent determinations of infarct extent after coronary occlusion in the rat.

Animals↗