Simultaneous nasopharyngeal and parotid gland Warthin's tumour: a case report.

Herein, a rare case of synchronous cystoadenolymphoma (Warthin's tumour) of the right parotid gland and the nasopharyngeal space is described. Although Warthin's tumour (WT) of the parotid gland is a common benign pathology, the occurrence of extra-parotid cystoadenolymphoma is rare. Extra-parotid WT have been mainly localised in the submandibular gland, periparotid region and occasionally in other sites, such as the oral cavity, hard palate and nasopharynx. The simultaneous occurrence of an intra-parotid and extra-parotid WT localisation, as in the case presented, is extremely uncommon.

Molecular strategies to define HLA haplotype loss in microdissected tumor cells.

Loss of heterozygosity (LOH) of chromosome 6p21 is an important mechanism that generates HLA haplotype loss in various human tumors. This mechanism produces non-reversible HLA-deficient tumor cells that can escape T cell immune responses in peptide-vaccinated cancer patients. However, the exact frequency of this mechanism is still unknown, because contaminating stroma in solid tumor tissues masks the tumor DNA obtained from solid samples. A microdissection technique was applied to 4-8 microm sections of cryopreserved tumor tissues from a group of colorectal and laryngeal carcinomas. Fifteen patients were analyzed for the presence of LOH associated with the beta(2)-microglobulin gene in chromosome 15, and five patients for LOH associated with HLA genes in chromosome 6. In two cases, autologous metastasis tissue samples were also available. The patients were selected for showing an altered HLA class I tumor phenotype as determined by immunohistological techniques. DNA was obtained from this microdissected material and amplified in order to detect the presence or absence of nine previously selected microsatellite markers. HLA sequence based typing (SBT) was also applied to these microdissected DNA samples to define the HLA genotype. Microdissection greatly improved the definition of LOH, with nearly 100% signal reduction in one of the alleles. In addition, this procedure allowed us to detect beta(2)-microglobulin LOH in tumors that expressed some HLA molecules. Our data indicate that this procedure can be successfully applied to microdissected samples from solid tumors, thus enhancing the power and sensitivity of LOH detection.

High frequency of altered HLA class I phenotypes in invasive colorectal carcinomas.

We analyzed the expression of HLA class I antigens in 78 tumor tissue samples obtained from patients diagnosed as having colorectal carcinomas. A broad panel of mAbs defining HLA monomorphic, locus-specific and allele-specific determinants was used. In addition, an antibody defining HLA-C locus-specific determinant (L31) was also tested. Previous reports on these tumors indicated HLA class I losses of 30 to 40%. At least 73% of the patients in the present study had a detectable HLA class I alteration. These altered HLA phenotypes were classified as total HLA loss (18%) (phenotype I); HLA-A locus-specific loss (9%) (phenotype IIIa); HLA-B locus-specific loss (8%) (phenotype IIIb); HLA-A and B locus losses (2%) and HLA allelic losses (36%) (phenotype IV). We found no HLA-C locus losses. Autologous peripheral blood lymphocyte HLA class I typing was always necessary to define phenotype IV. We also studied the CD3 zeta chain in tumor tissues to correlate possible changes in the CD3 signal transduction pathway with HLA alterations. The CD3 ratio was frequently altered, but this alteration could not be correlated with tumor HLA phenotypes. The high frequency of HLA class I losses in colorectal carcinomas suggests that this finding is a widespread phenomenon and may be required to escape T-cell recognition. It remains to be determined whether HLA expression is "normal" in the rest of the 27% of our patients.

Comparative analysis of the effects of iontophoretically applied dopamine in different regions of the rat brain, with special reference to the cingulate cortex.

A systematic comparison of the effects of iontophoresed dopamine (DA) was carried out in the neostriatum (NS), nucleus accumbens (Acb) and anterior cingulate (ACg), prefrontal (PF) and parietal (Par) cortex of urethane-anesthetized rats, before and after treatment with the specific DA uptake blockers GBR 12909 and Bupropion. Similar experiments were also conducted after DA denervation with 6-hydroxydopamine and after DA depletion with alpha-methyl-p-tyrosine. The average rate of spontaneous neuronal firing was comparable in all regions, except in the NS after DA depletion. A majority of the units were inhibited by DA in every region and condition tested. As assessed with the IT50 index, the responsiveness to DA was not markedly different between regions, indicating that the postsynaptic sensitivity to this amine is independent of the density of DA receptors and of DA innervation. In contrast, the average duration of DA inhibitions (RT90) was considerably longer (5-fold) in the intact ACg than in the PF, Par, NS, or Acb. Moreover, treatment with both DA uptake blockers reduced the duration of DA inhibitions in ACg (4- to 9-fold); while lengthening it in PF, NS and Acb; and having no apparent effect in Par. DA depletion and DA denervation also reduced the duration of the DA inhibitions in ACg without effect in Par. Taken together, these results provide further evidence for the existence of a presynaptic, positive-feedback mechanism in ACg, triggered by DA, and favouring the further release of this transmitter upon its reuptake in DA nerve terminals.

MHC class I and II antigens on gastric carcinomas and autologous mucosa.

The expression of HLA class I and II antigens was analysed in 30 primary gastric carcinomas, 27 autologous lymph node metastases and 25 autologous gastric mucosae. We used an immune alkaline phosphatase technique on cryostatic sections and mAbs directed against HLA class I monomorphic determinants, HLA-B locus-specific products and HLA-DR, -DP and -DQ molecules. In addition HLA class I genes were analysed in tumour tissue and compared by Southern blots with the RFLP from autologous mucosa using locus-specific HLA probes. Finally the infiltrating mononuclear cells were studied on gastric tumours and adjacent mucosa with mAbs defining CD4, CD8 and CD11b differentiation antigens. The results obtained showed that three out of 27 primary gastric carcinomas completely lack HLA-ABC antigens (10%). In addition, two primary tumours presented a variable expression. The remaining 22 tumours presented a homogeneous positive HLA class I expression. Interestingly, when the autologous mucosa was analysed, only 12 out 25 specimens were homogeneously stained with mAbs against HLA class I antigens, suggesting that this tissue may lack the expression of HLA antigens before becoming malignant. Indeed, the majority of the gastric carcinomas studied presented a higher HLA-ABC antigenic expression than autologous mucosa. Finally, the HLA expression observed in the primary tumour was similar to that observed in autologous metastases. As a second part of the study we have found a direct relationship between the expression of HLA-DR antigens in mucosa and the intensity of inflammatory infiltration. This relationship was not maintained in the tumour tissue. In the mucosa the CD4-positive T cell was the predominant lymphocyte, while it was CD8 in the HLA-DR-positive tumours. Finally the RFLP of class I genes did not show any differences in any of the cases when compared with autologous mucosa. We included in these studies DNAs from HLA class I-negative tumours, HLA positive and HLA-B-negative ones.

Phenotypic expression of histocompatibility antigens in human primary tumours and metastases.

HLA class I and II expression was studied on 244 (177 primary and 67 metastatic) solid human tumours of different origin. Alkaline immunophosphatase (APAAP) and immunoperoxidase were used on cryostatic sections to stain MHC antigens. Monomorphic MoAbs were used against class I heavy chain, beta 2-microglobulin, DR, DQ and DP molecules. Class I expression was homogeneous on colon, melanoma and epidermoidal primitive tumours. Loss of HLA class I antigens was more frequent on basal cell carcinomas and sarcomas and was related to tumour differentiation on larynx carcinoma. Class I expression was heterogeneous on breast, larynx and stomach primitive neoplasias. Class I negative tumours were more frequent on metastatic than on primitive melanomas. Divergence of class I between primary tumours and autologous metastases was observed on melanomas, larynx and colorectal carcinomas. Class II expression was heterogeneous on all tumours and in a large number of cases was associated with high intensity of leukocytic infiltrate. HLA-DR expression was higher than HLA-DP and HLA-DQ (DR greater than DP greater than DQ) and was related to tumour progression. Four human tumour cell lines were modulated with recombinant interferon-gamma for HLA class I and II antigens. Different HLA profiles were obtained: increased class I and II expression, increased class II or a low response. Finally, class I genes from 22 tumours were compared with autologous normal cells by Southern blot analysis: 12 tumours were class I positive and 10 negative. No clear differences in RFLP were observed that could be associated with class I rearrangement. The results are discussed in relation to the role that histocompatibility antigens may play in tumour progression and invasiveness.

HLA class I gene expression on human primary tumours and autologous metastases: demonstration of selective losses of HLA antigens on colorectal, gastric and laryngeal carcinomas.

The expression of HLA class I antigens was studied in 99 primary tumour (colorectal, gastric and laryngeal carcinomas) and 57 autologous metastases using immunohistological techniques and monoclonal antibodies against class I monomorphic determinants, HLA-B isotypic determinants and HLA polymorphic determinants. Fourteen per cent of colorectal, 9.6% of gastric and 20% of laryngeal carcinomas completely lacked class I molecules. Selective losses of HLA-B antigens were also detected in 8.8, 3.4 and 5.8% of these tumours respectively. Taking into account complete and selective loss of HLA-B the average alteration in the class I molecules expression totalled 21%. The comparison of class I expression between primary tumours and autologous metastases showed differences in 24% of the patients. These differences consisted mainly in a decrease of class I expression by metastases. Nevertheless, four types of divergence were detected in laryngeal carcinomas, namely: +/-, +/+, -/+, -/-. In addition, a clear correlation between degree of differentiation and class I expression was observed in laryngeal tumours. Finally, when class I gene RFLPs were compared with DNA from 15 tumours and autologous normal mucosa or peripheral lymphocytes, no differences were detected between these samples.

Vasoactive intestinal polypeptide acts synergistically with norepinephrine to depress spontaneous discharge rate in cerebral cortical neurons.

Cortical neurons are densely innervated by noradrenergic fibers and by intrinsic cortical interneurons containing vasoactive intestinal polypeptide (VIP). Biochemically, VIP and norepinephrine (NE) synergistically interact to stimulate the synthesis of cyclic AMP in cortical slices. Therefore, we sought physiological indices of this peptide-monoamine interaction by applying VIP and NE to single cortical neurons of the rat while recording their spontaneous discharge. VIP applied alone inhibited discharge of 24% and accelerated discharge in 20% of cortical neurons. NE alone had a predominantly depressant effect on the same neurons. However, when VIP was retested during the continuous application of subthreshold currents of NE, VIP exerted predominantly depressant effects. These synergistic inhibitions resulted even in cells previously showing excitations to VIP alone. If VIP alone was depressant, subthreshold NE further enhanced the VIP depression. Subthreshold amounts of phenylephrine, an alpha-adrenoceptor agonist, also produced comparable interactions, suggesting involvement of an alpha receptor, as in the biochemical studies. These results support a peptide-monoamine interaction in cortex that could have important ramifications for neuronal integration.