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Biomedical subjects

M Kyriakos

Publications and source records attributed to M Kyriakos.

At least 55 records · Page 3Linked to original sources

Effects of the adjuvants SGP and Quil A on the induction of experimental autoimmune thyroiditis in mice.

In the present study, two adjuvants, SGP and Quil A, were assessed for their ability to induce experimental autoimmune thyroiditis (EAT) in mice. SGP (a synthetic copolymer of starch, acrylamide, and sodium acrylate) and Quil A (a plant saponin) were compared with lipopolysaccharide (LPS) and complete Freund's adjuvant (CFA) given together with mouse thyroglobulin (MTg) for their ability to induce EAT in CBA/J mice. Immunization with MTg and LPS, MTg and CFA, or MTg with SGP was effective in inducing anti-MTg antibodies and histologic EAT, while MTg with Quil A was ineffective in inducing either anti-MTg antibodies or EAT. MTg with LPS was able to prime mice for the development of an in vitro spleen cell proliferative response to MTg while MTg with SGP or with Quil A was unable to prime spleen cells to proliferate detectably in response to MTg. MTg with LPS given in vivo primes CBA/J spleen cells for further activation by in vitro culture with MTg to transfer EAT to naive CBA/J recipients. MTg with SGP was also effective in priming CBA/J spleen cells for in vitro activation and transfer of EAT while MTg with Quil A was ineffective. The effective adjuvant activity of SGP and its lack of toxicity relative to LPS should make it a useful agent for further studies in murine models of EAT.

Acrylic Resins↗

The cellular basis for the Ia restriction in murine experimental autoimmune thyroiditis.

Susceptibility to experimental autoimmune thyroiditis (EAT) in the mouse is linked to the I-A subregion of the major histocompatibility complex. EAT can be induced in susceptible strains of mice by immunization with mouse thyroglobulin (MTg) and adjuvant. We have described a cell transfer system wherein spleen cells from EAT-susceptible CBA/J mice primed in vivo with MTg and lipopolysaccharide (LPS) can be activated in vitro with MTg to transfer EAT to naive syngeneic recipients. This cell transfer system was used to elucidate the cellular basis for the I-A restriction in EAT. While the cell active in transferring EAT was Thy 1+ I-A-, depletion of I-A+ cells from the in vitro culture prevented the activation of EAT effector T cells. MTg-pulsed mitomycin C-treated naive syngeneic spleen cells as antigen-presenting cells (APCs) could replace the I-A+ cells in vitro. Allogeneic (Balb/c) APCs were ineffective. Using APCs from several recombinant inbred strains of mice, it was shown that C3H/HEN and B10.A(4R) APCs were effective in activating MTg/LPS-primed CBA/J spleen cells to transfer EAT while B10.A(5R) APCs were ineffective. This maps the H-2 restriction to the K or I-A subregions. Addition of polyclonal anti-Iak or monoclonal anti-I-Ak or anti-L3T4 during in vitro activation inhibited both the generation of EAT effector cells and the proliferative response to MTg. Irrelevant anti-Ia reagents, monoclonal anti-I-Ek, and monoclonal anti-I-Jk were ineffective. Thus the I-A restriction in murine EAT appears to result from an I-A restricted interaction between Ia+ APCs and Ia- EAT effector T cells.

Animals↗

The role of cellular proliferation in the induction of experimental autoimmune thyroiditis (EAT) in mice.

Experimental autoimmune thyroiditis (EAT) can be induced in susceptible strains of mice by injection of mouse thyroglobulin (MTg) and adjuvant. Lymphocytes from immunized mice develop a proliferative response to MTg which generally correlates with the development of EAT. We utilize a cell transfer system wherein spleen cells from CBA/J mice primed with MTg and lipopolysaccharide (LPS) in vivo are activated by culture with MTg in vitro to transfer EAT to naive recipients. In vivo priming of CBA/J mice is required to develop an antigen specific proliferative response to MTg. This response is optimal between 48 and 90 hr of culture at an MTg concentration of 125-250 micrograms/ml. The correlation between proliferation and transfer of EAT is not absolute as primed Balb/c X CBA/J F1 and AKR lymphocytes do not proliferate detectably in response to MTg but can be activated to transfer EAT; primed Balb/c lymphocytes neither proliferate nor transfer EAT. Proliferation per se is not sufficient to activate cells to transfer EAT as culture with nonspecific mitogens is not effective in activating primed CBA/J spleen cells to transfer EAT. However, lymphoblasts generated during in vitro culture of primed CBA/J spleen cells with MTg are responsible for transfer of EAT; small lymphocytes are ineffective. We conclude that antigen specific proliferation in response to MTg is essential in activating lymphocytes in vitro to transfer EAT.

Animals↗

Metastatic chondroblastoma. Report of a fatal case with a review of the literature on atypical, aggressive, and malignant chondroblastoma.

A boy with metastatic and fatal chondroblastoma is presented. Unlike previously published examples of metastatic chondroblastoma, these metastases developed before any operative manipulation of the primary tumor. The histologic characteristics of the primary, metastatic, and locally recurrent tumors were those of a conventional chondroblastoma. A review of published cases of atypical, aggressive, and malignant chondroblastoma is presented with current follow-up information. Although some metastatic chondroblastomas may result from operative manipulation of the primary tumor and are clinically benign, other histologically benign chondroblastomas exist that are capable of pursuing a malignant course. The authors designate these as malignant chondroblastomas. No histologic criteria exist for the separation of these tumors.

Antineoplastic Combined Chemotherapy Protocols↗

Induction of experimental autoimmune thyroiditis in mice with in vitro activated splenic T cells.

Spleen cells from CBA/J or SJL mice sensitized with mouse thyroglobulin (MTg) and lipopolysaccharide (LPS) could be activated in vitro with MTg to transfer experimental autoimmune thyroiditis (EAT) to normal syngeneic recipients. EAT induced by these transferred cells was similar in incidence and severity to EAT induced by active immunization of mice with MTg and adjuvant and cells from EAT-resistant Balb/c mice could not be activated to induce EAT. The specific antigen MTg was required both for initial sensitization of the mice and for activation of spleen cells in vitro. The cells that were active in transferring EAT to mice were shown to be T cells. Removal of B cells from the cultured spleen cells had no effect on the ability of the cells to induce EAT.

Animals↗

Disseminated histoplasmosis presenting as an acute tenosynovitis.

Disseminated histoplasmosis is usually a multifocal process with a wide variety of clinical presentations. Despite frequent bone marrow involvement, overt bone and joint disease is uncommon and isolated synovial involvement is extremely rare. We describe in this report an unusual case of disseminated histoplasmosis presenting as acute tenosynovitis. To our knowledge, this is only the second reported case of synovial involvement by H. capsulatum without a concomitant osseous lesion.

Acute Disease↗

Histiocytic reaction to hip arthroplasty.

Pain secondary to loosening of a total hip prosthesis is a common complaint and a major complication after surgery. Periprosthetic lucency is a well-recognized result of loosening of the prosthesis and of infection. We describe histiocytic proliferation as an additional cause of periprosthetic lucency and lytic change in two patients. To our knowledge, this has not been previously reported in the radiological literature.

Acetabulum↗

Prevention of autoimmune uveitis by competitive immunization with bovine gamma globulin.

The effect of antigenic competition on the development of autoallergic experimental uveitis and autoallergy to ocular antigens was studied. Strain 13 guinea pigs were immunized with adjuvants containing either National Institutes of Health strain retina-uvea extract or retina-uvea extract plus bovine gamma globulin (BGG). They were later reimmunized with ocular extract and BGG or ocular extract alone, in adjuvant. They were observed weekly by slit-lamp examination. At the end of the study, they were skin tested using strain 13 retina-uvea extract. The eyes of certain groups were examined histologically. Immunization and reimmunization with ocular extract produced uveitis. The addition of BGG to the initial immunization prevented the development of uveitis even after reimmunization with ocular extract alone. It did not, however, necessarily prevent the development of delayed type skin sensitivity to retina-uveal extract.

Animals↗

Focal hematopoietic hyperplasia of the rib--a form of pseudotumor.

Two patients are presented who had a resection of a solitary expansile rib lesion. The radiologic features were nonspecific and the lesions were thought to represent either fibrous dysplasia, myeloma, or metastatic disease. Histologically, the lesion consisted of focal hyperplasia of the bone marrow involving all hematopoietic elements. The marrow expanded the rib, eroded the cortex, and extended into the adjacent soft tissue. Neither patient had any underlying hematologic abnormality. A search of the English language literature failed to discover a description of a similar lesion. From the clinical course and follow-up information, the process appears to be benign. The authors believe the lesion is a form of pseudotumor, and propose that it be designated as "focal hematopoietic hyperplasia of rib" or "hematopoietic pseudotumor."

Aged↗

Adoptive transfer of experimental autoimmune thyroiditis (EAT) in guinea pigs: requirement for Ia-positive antigen-presenting cells for in vitro activation of effector T cells.

Lymph node T cells from guinea pigs sensitized in vivo with guinea pig thyroglobulin (GPTG) could transfer experimental autoimmune thyroiditis (EAT) to normal syngeneic recipients after in vitro culture with GPTG or GPTG-pulsed peritoneal exudate cells (PEC). Although EAT effector T cells have been shown previously to be Ia negative at the time of transfer, the addition of specific anti-Ia serum to the cultures inhibited effector cell activation. The inhibitory effect of anti-Ia on effector-T-cell activation was shown to be due to inhibition of the function of antigen-presenting PEC rather than to an effect on the sensitized T cell. Moreover, only Ia-positive PEC could present antigen in this system and Ia matching between the PEC and the T cell was required for effective T-cell activation. GPTG-pulsed Strain 2 (EAT susceptible) and Strain 13 (EAT resistant) PEC could both present antigen to T cells from 2 X 13 F1 guinea pigs although Strain 2 PEC were more effective, suggesting that defective antigen presentation by macrophages may at least partially explain the relative resistance to EAT of Strain 13 guinea pigs. These results indicate that interaction between Ia-positive PEC and sensitized T cells in vitro is necessary for the development of active effector T cells that can transfer EAT.

Animals↗

Effect of guinea pig thyroglobulin in incomplete Freund's adjuvant on experimental autoimmune thyroiditis induced by in vitro-activated lymph node cells.

Guinea pigs injected with guinea pig thyroglobulin (GPTG) in incomplete Freund's adjuvant (IFA) have been shown to be unresponsive to challenge with GPTG in complete Freund's adjuvant (CFA). However, effector cells which transfer experimental autoimmune thyroiditis (EAT) can be demonstrated in cultured lymph node cells (LNC) of unresponsive animals, indicating that GPTG in IFA does not suppress the initial sensitization of EAT effector cells. LNC from unresponsive animals were unable to suppress the in vitro activation of effector LNC or to suppress EAT when cotransferred with effector cells. When GPTG in IFA was given to animals which were used as recipients of effector cells, the production of EAT was markedly suppressed. These results suggest that GPTG in IFA can suppress EAT either by preventing effector cells from interacting with the thyroid or by interfering with the function of a cell in the normal recipient which may interact with effector cells to result in the lesions of EAT.

Animals↗

Histiocytoid endothelial cells in a malignant schwannoma.

Unusual vascular lining cells within a malignant schwannoma prompted a comparative study of these cells and the endothelial cells in cases of histiocytoid hemangiomas. The endothelial cells in all cases showed similar morphologic and immunohistochemical features. Such endothelial cells were not found in the capillaries of a pyogenic granuloma or in those of developing rat skin. It is postulated that these distinctive endothelial cells may be more widely distributed than was previously thought and that morphologic changes associated with these cells may be induced by vasoactive substances.

Animals↗

Aneurysmal ("angiomatoid") fibrous histiocytoma of the skin.

Seventeen cases are reported of a variety of cutaneous fibrous histiocytoma, which we have designated as aneurysmal ("angiomatoid") fibrous histiocytoma. These lesions differ from the classical cutaneous fibrous histiocytoma in both their clinical presentation and pathologic features. Clinically, they may be larger than the usual cutaneous fibrous histiocytoma, are blue, black, or dark red, and have a cystic consistency. They are most commonly located on the extremities and may be associated with symptoms of pain and rapid growth. The clinical diagnosis of fibrous histiocytoma is seldom considered in the differential diagnosis, which may include malignant melanoma, hemangioma, neurofibroma, and nonspecific cyst. Histologically, the lesions are characterized by the presence of large, blood-filled tissue spaces, which, at times, account for up to one half their size. These spaces lack an endothelial lining, being surrounded and lined by histiocytes, many of which contain hemosiderin pigment, fibroblasts, and foam cells. The solid portions of the tumor have the usual features of a cutaneous fibrous histiocytoma. This "angiomatoid" lesion is closely allied to what has been termed "hemosiderin histiocytoma," which appears to be a precursor stage in its formation. The presence of extravasated erythrocytes in combination with a spindle-cell stroma may lead to an erroneous diagnosis of Kaposi's sarcoma. This cutaneous tumor has architectural and cytologic similarities to its malignant soft tissue counterpart recently described as angiomatoid malignant fibrous histiocytoma. However, unlike the latter, the cutaneous lesion is benign and lacks the prominent inflammatory infiltrate, pleomorphic appearance, and systemic manifestations of its soft tissue counterpart. The distinctive clinical and pathologic features of the cutaneous lesion serve to separate it as a specific variant of the cutaneous fibrous histiocytomas.

Adolescent↗

Concurrence of metaphyseal fibrous defect and osteosarcoma. Report of a case and review of the literature.

The case of a 15-year-old girl with juxtaposition of a femoral metaphyseal fibrous defect (fibrous cortical defect) and an osteosarcoma is reported. Despite the relatively common occurrence of metaphyseal fibrous defects, their reported association with other bone tumors is exceedingly rare. Only two previous acceptable examples of this association were found. Reports of malignant transformation of metaphyseal fibrous defect were reviewed and rejected because they lacked convincing radiologic or histopathologic evidence of a pre-existent benign fibrous lesion. The finding of a malignant bone tumor in association with a metaphyseal fibrous defect appears to be a chance occurrence.

Adolescent↗

Adoptive transfer of experimental autoimmune thyroiditis (EAT) with in vitro activated lymph node cells from thyroglobulin-sensitized guinea pigs: characterization of the cell that transfers EAT.

Relatively low numbers of lymph node cells (LNC) from Strain 2 or Strain 13 guinea pigs sensitized with guinea pig thyroglobulin (GPTG) could transfer experimental autoimmune thyroiditis (EAT) to normal syngeneic recipients after in vitro culture with GPTG. The EAT induced in recipients of cultured LNC was similar in incidence and severity to EAT induced by active immunization with GPTG in complete Freund's adjuvant. The cells that were effective in transferring EAT were shown to be immunoglobulin-negative, nylon wool nonadherent, and Ia-negative. The effector cells were sensitive to irradiation after in vitro activation, indicating that cell proliferation in the recipient is required for development of EAT. Recipient animals often developed moderate to severe lesions of EAT yet none had detectable delayed hypersensitivity to GPTG and the majority also had no detectable anti-GPTG antibody.

Animals↗