[Benign parotid lymphoepithelial cysts associated with HIV infection]

HIV infections are often related with lymphoepithelial benign cysts of the parotid gland; these lesions are uncommon and other salivary glands are rarely involved. The diagnosis, often difficult, is based on imaging techniques, like computed tomography, and pathologic techniques, like fine needle aspiration biopsy. The therapeutic approach can be performed by simple aspiration, surgical resection, pharmacotherapy, or radiotherapy. Three cases of HIV-related lymphoepithelial benign cysts of the parotid gland observed at the Department of Maxillofacial Surgery of the "Federico II" University of Naples and at the Department of Oral and Maxillofacial Surgery of "La Paz" Hospital of the Universitad Autonoma of Madrid are described.

Fluorescence Anisotropy of Probes Solubilized in Micelles of Tetradecyltrymethylammonium Bromide: Effect of Ethylene Glycol Added

This paper deals with the effect of ethylene glycol on the micelle formation of tetradecyltrimethylammonium bromide. The effect of ethylene glycol addition on the fluorescence anisotropy of several probe molecules residing in different regions of the micelle was investigated to address the solvent penetration in the micelle structure. Fluorescence depolarization measurements were carried out on micellar systems containing two different hydrophobic dyes, namely, perylene and diphenylbutadiene, and a hydrophilic one, fluorescein. The steady-state anisotropy values obtained in these experiments were used to estimate the microviscosity of the corresponding micellar regions. It is observed that the microviscosity in the hydrophobic regions of micelles were roughly constant with EG addition, indicating that the micellar interior does not undergo significant structural changes by the presence of cosolvent in the solution. However, the microviscosity at the micellar surface, as determined by using fluorescein as a probe, is found to increase with EG addition. This perturbation of the micellar surface is ascribed to the solvent penetration in this region of the micelle, where there is probably participation in the solvation layer of the micelle headgroups. Copyright 2000 Academic Press.

Expression of GCAP1 and GCAP2 in the retinal degeneration (rd) mutant chicken retina

We cloned the guanylate cyclase activating proteins, GCAP1 and GCAP2, from chicken retina and examined their expression in normal and predegenerate rdlrd chicken retina. Northern analyses show that the amounts of the single transcripts encoding GCAP1 and GCAP2 are reduced to about 70% of normal levels in rdlrd retina. Western analyses reveal that GCAP2 levels appear normal in this retina, while GCAP1 levels are reduced by more than 90%. The specific downregulation of GCAP1 in rdlrd retina is consistent with a model for this disease in which activation of guanylate cyclase in the photoreceptors is abnormal, resulting in low levels of cGMP and an absence of phototransduction.

Molecular characterization of human and mouse photoreceptor guanylate cyclase-activating protein (GCAP) and chromosomal localization of the human gene

Guanylate cyclase-activating protein (GCAP) is a novel Ca(2+)-binding protein that stimulates synthesis of cGMP in photoreceptors. Molecular cloning of human and mouse GCAP cDNA revealed that the known mammalian GCAPs are more than 90% similar, consist of 201-205 amino acids, and contain three identically conserved EF hand Ca2+ binding sites. The sequence homology with recoverin, a related photoreceptor Ca(2+)-binding protein, is less than 35%. In situ hybridization in primate retinas shows that the GCAP gene is expressed exclusively in photoreceptor inner segments. To investigate the GCAP gene structure, we probed 10 eucaryotic genomic DNAs with a bovine GCAP cDNA under stringent conditions. The results demonstrate that the GCAP gene has been well conserved during evolution of vertebrate species and that each gene is most likely present as a single copy. By genomic cloning, polymerase chain reaction, mapping, and direct sequencing, we show that the human GCAP gene spans approximately 6 kilobases of genomic DNA, and consists of four exons (> 250, 146, 94, and 800 base pairs) separated by three introns (4.5 kilobases, 370 base pairs, and 347 base pairs). Using human/hamster hybrid panels and fluorescent in situ hybridization, the GCAP gene was localized to the short arm of chromosome 6 (p21.1).

Molecular cloning and characterization of retinal photoreceptor guanylyl cyclase-activating protein

Guanylyl cyclase-activating protein (GCAP) is thought to mediate Ca(2+)-sensitive regulation of guanylyl cyclase (GC), a key event in recovery of the dark state of rod photoreceptors following light exposure. Here, we characterize GCAP from several vertebrate species by molecular cloning and provide evidence that GCAP contains a heterogeneously acylated N-terminal region that interacts with GC. Vertebrate GCAPs consist of 201-205 amino acids, and sequence analysis indicates the presence fo three EF hand Ca(2+)-binding motifs. These results establish that GCAP is a novel photoreceptor-specific member of a large family of Ca(2+)-binding proteins and suggest that it participates in the Ca(2+)-binding proteins and suggest that it participates in the Ca(2+)-sensitive activation of GC.

Salivary duct carcinoma: a report of nine cases

Nine cases of salivary duct carcinoma are presented. Eight lesions were located in the parotid gland and one in the submandibular gland. Tumor size was greater than 3 cm in four cases (44%), and facial paralysis was observed in five tumors (62.5%). Lymph node metastases were observed macroscopically or microscopically in seven patients. Perineural and lymphatic invasion were detected in eight and seven cases, respectively. Free surgical margins were obtained in eight of the nine patients (88%). Adjuvant postoperative irradiation was delivered in eight patients. Five patients died of disease in spite of the different clinicopathologic characteristics and aggressiveness of the surgery and irradiation. None of the parameters studied correlated with the final outcome.

Thoracic complications of deeply situated serous neck infections

Nine cases of complicated deep neck infections, occurring during a period of twelve years are presented. Complications observed were cervico-thoracic necrotizing fasciitis in 3 cases, purulent pleural effusion in 6 cases, pericardial effusion in 2, mediastinitis in 8 cases, jugular vein thrombosis and rupture of the innominate artery in one case each. Although 2 cases were managed initially with blind endotracheal intubation, all cases finally required tracheostomy. A cervico-mediastinal approach was useful for the early mediastinal involvement. Two patients died because of inadequacy of the multiple surgical procedures resulting in persistent infection and multi-organ failure and one because of uncontrollable bleeding after innominate artery rupture.