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Biomedical subjects

A L Morton

Publications and source records attributed to A L Morton.

12 recordsLinked to original sources
PubMed1993

CD4+ T cell-mediated rejection of major histocompatibility complex class I-disparate grafts: a role for alloantibody.

Experimental studies of the T cell requirement for rejection of class I major histocompatibility complex (MHC)-disparate grafts have generated controversy over both the autonomy of CD8+ T cells and the mechanism whereby CD4+ T cells are able to independently mediate rejection. In this study of rejection of RT1Aa class I MHC-disparate rat cardiac and skin allografts by high-responder PVG RT1u recipients, we show that elimination of CD8+ T cells [by anti-CD8 monoclonal antibody (mAb) administration in vivo] fails to prolong graft survival, whereas partial depletion of CD4+ T cells (by anti-CD4 mAb treatment) markedly delays rejection of class I-disparate heart grafts, and marginally prolongs survival of skin grafts. Anti-CD4-treated PVG-RT1u athymic nude rats reconstituted with CD8+ T cells failed to reject class I-disparate skin grafts for several weeks and eventual rejection correlated with re-emergence of a small number of donor derived CD4+ T cells. Conversely, anti-CD8-treated nude rats reconstituted with CD4+ T cells alone rapidly rejected class I-disparate skin grafts. Passive transfer of anti-class I immune serum to anti-CD4-treated euthymic recipients promptly restored their ability to specifically reject a class I-disparate heart graft. Similarly, passive transfer of immune serum to PVG-RT1u nude rats bearing skin allografts caused destruction of class I-disparate but not third-party grafts. These results demonstrate that CD4+ T cells are both necessary and sufficient to cause rejection of class I-disparate heart and skin grafts in this model and that CD4+ T cell-dependent alloantibody plays a decisive role in effecting rejection.

Animals↗
PubMed1991

Malignant cyst of the lateral aspect of the neck: branchial cleft carcinoma or metastasis?

A 58-year-old man had a left jugulodigastric mass, which was found to be cystic by computed tomography, and no evidence of other lesions. Grossly and histologically, the surgical specimen consisted of a thin-walled, fluid-filled cyst lined by squamous epithelium that varied in appearance from benign to invasive squamous cell carcinoma. The findings supported a differential diagnosis of branchial cleft carcinoma (BCCA) versus cystic growth of a lymph node metastasis from an occult malignancy. On this basis, guided biopsies of the upper aerodigestive tract were performed, with strong suspicion of a tonsillar bed lesion. Microscopic examination revealed the primary tumor within tissue excised from the left tonsillar fossa. Comparison of the current case with cases of BCCA and cystic tonsillar metastases from the literature illustrated the potential pitfalls in rendering a diagnosis of BCCA. Recognition of this lesion as a distinctive clinical variant of oropharyngeal carcinoma is warranted.

Branchioma↗
PubMed1991

Internal maxillary artery variability in the pterygopalatine fossa.

The third segment or pterygopalatine branch of the internal maxillary artery has variable branching in the pterygopalatine fossa. This variability in branching can lead to failure in controlling persistent nasal epistaxis by transantral ligation. Although the surgical approach has been previously studied, a systematic classification of this branching has not been previously reported. Through the performance of serial cadaver dissections in the PPF, we have demonstrated the anatomic course and variations of this third segment and offer a relatively simple classification system.

Adipose Tissue↗
PubMed1990

Paranasal sinus Burkitt's lymphoma in a human immunodeficiency virus (HIV) positive male.

Patients infected with the HIV virus have been reported to develop several malignant neoplasms, the most frequent of which is Kaposi's sarcoma. Although an increasing number of lymphomas, primarily non-Hodgkin's lymphomas, have been described who are HIV seropositive, few cases of Burkitt's lymphoma have been reported in patients. We report a case of an HIV-seropositive man who had paranasal sinus Burkitt's lymphoma underlying chronic maxillary sinusitis. Successful remission was achieved with chemotherapy.

Adult↗
PubMed1989

A multicenter study to compare cefotetan alone with cefotetan and metronidazole as prophylaxis against infection in elective colorectal operations.

The role of antibiotic prophylaxis in operations upon the colon and rectum is now well recognized. In this study, the efficacy of cefotetan, a broad spectrum cephamycin antibiotic, given alone (n = 315), is compared with that of the combination of cefotetan and metronidazole (n = 300). The groups were well matched for age, sex, pathologic features and operations performed. There was no statistical difference in the incidence of operation-related infection between the two groups. We conclude that cefotetan given alone is as effective as the combination of cefotetan and metronidazole for prophylaxis against operation-related infection in elective colorectal operations.

Adult↗
PubMedDate not supplied

Anaplastic large cell lymphoma.

Anaplastic large cell lymphoma (ALCL) or Ki-1 lymphoma is a recently described and distinctive non-Hodgkin's lymphoma. Cervicofacial adenopathy caused by ALCL may mimic involvement by metastatic carcinoma or other malignancies common to the head and neck. A case in which ALCL was originally interpreted as metastatic nasopharyngeal carcinoma is presented. The clinicopathologic features of this uncommon entity are discussed.

Adult↗