Immunohistochemical characterization of a new monoclonal antibody reactive with dengue virus-infected cells in frozen tissue using immunoperoxidase technique.

This paper presents a novel monoclonal antibody shown to react with cytoplasmic antigens in various dengue infected human frozen organs from autopsy and necropsy specimens. Strong reactivity was found in hematopoietic cells, including immunoblasts, lymphocytes, plasma cells and macrophages of spleen, lymph node, lung, kidney and stomach. Strikingly, strong positivity was demonstrated in cerebral cortex neurones, Purkinje cells, choroid plexus and blood vessels in addition to astrocytes and microglia. Neurotropism of the virus could explain the meningitis, encephalitis, mononeuropathy and polyneuropathy observed by direct toxicity, but noted especially after an activation of mononuclear phagocytes and amplification of the immune response with subsequent vascular inflammation and formation of immune complexes.

Orbital amyloidoma (isolated amyloidosis): a case report.

This is the first case report of primary orbital amyloidoma in a 56-year-old Thai man who presented with proptosis for 4 days. He also complained of orbital discomfort associated with palpitation during the past 4 months. He was treated with corticosteroid for 6 months and slight left orbital pain ensued after cortisone discontinuation. Surgical removal of the orbital mass was done and proved to be "Amyloidoma" by multiple method technologies AL type. His visual acuity and proptosis were improved. Investigation for systemic amyloidosis was done by rectal biopsy and protein electrophoresis but there was no evidence of systemic amyloidosis. The authors reported the first case of orbital amyloidoma in Thailand.

Histopathologic spectrum of AIDS-associated lesions in Maharaj Nakorn Chiang Mai Hospital.

The histopathological alterations in various organs and the presence of AIDS-associated lesions were studied in 86 biopsy and 29 necropsy specimens of AIDS patients. The most common cancer seen in this study were malignant lymphomas (4% of cases) with development of extensive extranodal lymphomatous involvement from the outset. Although a preponderance of high grade B-cell pathologic subtypes is found in AIDS-associated lymphoma, we also report the first case of T-lymphoblastic lymphoma with a picture of acute lymphoblastic leukemia (T-ALL). Tuberculosis (34% of cases) was the most common opportunistic infection presented in tissue sections, and the majority of tissue biopsies revealed poorly organized granulomas and extensive necrosis with numerous bacilli. Penicilliosis (20% of cases) appeared to be the most common cutaneous lesion with multiple organ involvement. The involved organs showed a partially anergic tissue reaction characterized by poorly formed granulomas with diffuse infiltrate of fungi-laden macrophages and lymphoid cell depletion. This organism has to be distinguished from Histoplasma capsulatum and other yeast-form fungi. Co-existing cytomegalovirus and P. carinii infections were the predominant findings in lung necropsy specimens from pediatric patients who died from AIDS. A major pathologic feature in this group was diffuse alveolar damage stage II to III with heavy loads of organism and extensive lymphoplasmacytic infiltration.