Acinic Cell Carcinoma with Extensive Neuroendocrine Differentiation: A Diagnostic Challenge

Primary salivary gland carcinoma with neuroendocrine differentiation is of rare occurrence, especially so in the parotid gland. Amongst the various reported primary tumors with neuroendocrine differentiation, acinic cell carcinoma (ACC) one such tumor. A 48 year old lady presented with a gradually increasing right infra-auricular swelling for a period of 1 year which enlarged suddenly in a short period. Contrast Enhanced Computed Tomography (CECT) suggested diagnosis of Pleomorphic Adenoma. Fine Needle Aspiration Cytology (FANC) yielded a cystic fluid suggesting a possibility of Warthin’s tumor or Oncocytic lesion. Intraoperative findings were suggestive of a Warthin’s tumor. Initial histopathological examination of the tumor was suggestive of neuroendocrine carcinoma. However, extensive sectioning revealed peripheral islands of ACC. Immunoexpression of S-100, Neuron specific Enolase (NSE), Chromogranin A and Synaptophysin confirmed the diagnosis. The possibility of neuroendocrine differentiation in a primary salivary gland tumor should be kept in mind whenever a salivary gland tumor shows only neuroendocrine histology.     

Metastatic mammary carcinoma of the middle ear

Malignancies of the middle ear and mastoid are rare and secondaries in the ear are extremely rare. A rare case of metastic adenocarcinoma from the breast is presented herewith.     

Effect of melanotropin release inhibiting factor on changes by haloperidol and centbutindole in cerebral cortical 5-hydroxytryptamine receptors

The effect of melanotropin release inhibiting factor (Pro-Leu-Gly-NH2, MIF) was determined on changes induced by two neuroleptics, haloperidol and centbutindole, in cerebral cortical 5-hydroxytryptamine (5-HT) receptors. Male Sprague-Dawley rats were injected daily i.p. with vehicle, haloperidol (1.0 mg/kg) or centbutindole (0.5 mg/kg), respectively, for 21 days. On day 22, these 3 groups were further divided into 2 subgroups and injected with either vehicle or MIF (2.0 mg/kg, i.p.) daily for 3 days. 3H-5-HT was used to study 5-HT1 receptors, and 3H-spiroperidol to label 5-HT2 receptors in the cerebral cortex. Chronic administration of haloperidol significantly increased (39.7%) the maximal binding capacity (Bmax) of 3H-5-HT binding to 5-HT1 receptors. Dissociation constant (Kd) values did not change. Centbutindole had no effect on 5-HT1 receptors. MIF had no effect on 5-HT1 receptors, nor did it alter haloperidol-induced increases in the Bmax of 3H-5-HT binding to 5-HT1 receptors. Chronic administration of centbutindole significantly increased (61.1%) the Bmax of 3H-spiroperidol binding to 5-HT2 receptors. No change occurred in the Kd values. Chronic treatment with haloperidol had no effect on 5-HT2 receptor characteristics. MIF had no effect on 5-HT2 receptors or on the increase in 5-HT2 receptor density induced by centbutindole. The behavioral syndrome induced by 5-hydroxytryptophan (5-HTP) (50, 100 and 200 mg/kg, i.p.) was also measured in rats treated chronically with haloperidol or centbutindole. Haloperidol had no effect on the 5-HTP syndrome, whereas centbutindole stimulated by 24-45% the intensity of the syndrome.(ABSTRACT TRUNCATED AT 250 WORDS)     

Neuropathogenesis of Chimeric Simian/Human Immunodeficiency Virus infection In Pig-tailed and Rhesus Macaques

We recently reported that a chimeric simian/human immunodeficiency virus (SHIV_KU-1) developed in our laboratory caused progressive depletion of CD4⁺T lymphocytes and AIDS within 6 months of inoculation into pig-tailed macaques (M.nemestrina). None of the pig-tailed macaques showed productive SHIV infection in the central nervous system (CNS). In this report, we show that by further passage of the pathogenic virus in rhesus macaques [M. mulatta], we have derived a new strain of SHIV (SHIV_KU-2) that has caused AIDS and productive CNS infection in 3 of 5 rhesus macaques infected with the virus. Productive replication of SHIV in the CNS was clearly shown by high infectivity titers and p27 protein levels in brain homogenates, and in 2 of the 3 rhesus macaques this was associated with disseminated, nodular, demyelinating lesions, including focal multinucleated giant cell reaction, largely confined to the white matter. These findings were reminiscent of HIV-1 associated neurological disease, and our immunohistochemical and in situ hybridization data indicated that the neuropathological lesions were associated with the presence of SHIV-specific viral antigens and nucleic acid respectively. However, the concomitant reactivation of opportunistic infections in these macaques suggested that such pathogens may have influenced the replication of SHIV in the CNS, or modified the neuropathological sequelae of SHIV infection in the rhesus species, but not in pig-tailed macaques. Our findings in the two species of macaques highlight the complexities of lentiviral neuropathogenesis, the precise mechanisms of which are still elusive.     

The BPV-1 E5 oncoprotein expressed in Schizosaccharomyces pombe exhibits normal biochemical properties and binds to the endogenous 16-kDa component of the vacuolar proton-ATPase

The 44-amino-acid E5 oncoprotein of bovine papillomavirus type 1 transforms immortalized murine fibroblast cell lines. This highly hydrophobic protein forms homodimers, localizes to intracellular membrane compartments (including the Golgi apparatus), and forms a complex with the 16-kDa membrane-embedded constituent (16k) of the vacuolar proton-ATPase. To develop a system for the genetic and biochemical analysis of the E5/16k interaction, the E5 gene was cloned into a new vector which was designed for expression in the fission yeast Schizosaccharomyces pombe. The E5 protein synthesized in this system dimerized normally and bound to endogenous and overexpressed S. pombe 16k protein. Comparison of the S. pombe and mammalian 16k proteins showed strong conservation in carboxyl-terminal amino acids but greater variation in the amino-terminal sequences, suggesting that E5 was interacting with the 16k carboxyl domains. Finally, a new protein epitope tag is described which permitted for the first time the coprecipitation of E5 with antibodies directed against the 16k protein.     

Autosomal dominant inheritance of spondyloenchondrodysplasia

Spondyloenchondrodysplasia comprises generalized enchondromatosis with platyspondyly and is thought to be inherited as an autosomal recessive condition. A mother and son are reported with typical features of spondyloenchondrodysplasia. Their similar radiographic and MRI findings are presented. The radiologic appearance of the spine changed over time, illustrating the evolving phenotype of this condition. Transmission from mother to son suggests that dominant pattern of inheritance is possible. A classification of the enchondromatoses is discussed.