Topography of median eminence somatostatinergic innervation

Somatostatin (SRIF) in the central nervous system is mostly concentrated in the median eminence (ME). Immunocytochemical methods have revealed high densities of SRIF-positive perikarya between the preoptic area and the periventricular nucleus of the hypothalamus (NPE). The aim of the present study was to define more precisely the specific pathways of SRIF neurons from NPE to the ME. SRIF levels were measured by radioimmunoassay, following various hypothalamic transections. Frontal periventricular sections decreased SRIF-ME content by 70% (P less than 0.01), when located at the anterior end of the ME but no diminution was observed when the cuts were located anteriorly or posteriorly. Parasaggital transections decreased SRIF-ME levels by 50% (P less than 0.05) when located at the outer border of the ventromedial and premammillary nucleus, but the decrease was not significant when cuts were located anteriorly. Taken together, our data indicate that most SRIF-containing neurons, originating in the NPE, do not reach the ME directly along the border of the 3rd ventricle; instead they form a loop across the medial forebrain bundle before re-entering the mediobasal hypothalamus at the ME level.     

Using polymerase chain reaction to human papillomavirus in oral and pharyngolaryngeal carcinomas

Purpose: Increasingly, evidence has shown that human papillomavirus (HPV) plays a role in the induction of certain carcinomas. The presence of HPV sequences in 56 previously untreated oral and pharyngolaryngeal carcinomas was examined by the polymerase chain reaction (PCR).Materials and Methods: After DNA extraction, samples underwent 40 replication cycles with specific oligonucleotide primers corresponding to sequences from the E6 open-reading frame of HPV-6b, HPV-16, and HPV-18. To determine the E6 genomic integration, positive samples were processed with specific primers for the corresponding HPV L1 genes. Genomic HPV DNA cloned into PBR 322 was used as positive control.Results: HPV E6 DNA of the 6b and 16 types was detected in 14 patients (25%). The L1 gene was not present.Conclusion: Detected HPV E6 DNA might be integrated into the cell genome in the positive cases as indicated by the absence of the L1 gene-coding for the viral capside. Histological and clinical parameters, such as tumor location, degree of differentiation, stage, recurrence, and survival rates, were unrelated to the presence of HPV.     

Pseudotumor associated with polytetrafluoroethylene sleeves

We report the case of a patient who was operated on in February 2001. We performed a wedge resection of the upper right lobe. The pathologic examination demonstrated a lung adenocarcinoma (pT2N0M0, R0). We used staple line reinforcement material (ePTFE) during the operation because the patient had an important emphysema. We re-operated in January 2005 because during follow-up we observed a suspicious image that suggested a tumoral relapse. Histopathological study showed extrinsic material compatible with the one used in the original resection.     

Analysis of ALK-1 and endoglin in newborns from families with hereditary hemorrhagic telangiectasia type 2

ALK-1 (activin receptor-like kinase-1), a type I receptor of the transforming growth factor (TGF)-beta superfamily, is the gene mutated in hereditary hemorrhagic telangiectasia type 2 (HHT2) while endoglin is mutated in HHT1. Using a novel polyclonal antibody to ALK-1, we measured ALK-1 expression on human umbilical vein endothelial cells (HUVEC) of newborns from HHT families whose affected members had normal endoglin levels. ALK-1 levels were specifically reduced in three HUVEC with ALK-1 missense mutant codons, and normal in two newborns not carrying the missense mutations present in the clinically affected relatives. Levels were also normal in a HUVEC with deletion of S232 in the ATP binding site of ALK-1. Thus HHT2 appears to be associated with a loss of function of the mutant allele due to a reduction in either protein level or activity. We also report three new ALK-1 missense mutations leading to G48E/A49P, C344Y and E407D substitutions. In COS-1 transfected cells, ALK-1 was found in the TGF-beta1 and -beta3 receptor complexes in association with endoglin and TbetaRII, but not in activin receptor complexes containing endoglin. In HUVEC, ALK-1 was not detectable in the TGF-beta1 or -beta3 receptor complexes. However, in the absence of ligand, ALK-1 and endoglin interactions were observed by immunoprecipitation/western blot in HUVEC from normal as well as HHT1 and HHT2 patients. Our data suggest a transient association between these two proteins of the TGF-beta superfamily, both required at a critical level to ensure vessel wall integrity.     

Convulsions and wet-dog shakes produced by systemic or intrahippocampal administration of ruthenium red in the rat

Summary In this work we have studied in the rat the behavioral effects of the intraperitoneal (i.p.) and intrahippocampal (i.h.) administration of ruthenium red (RuR), an inorganic dye which has been shown to inhibit neurotransmitter release in synaptosomes. The i.p. injection induced initially flaccid paralysis and subsequently generalized tonic-clonic convulsions. It contrast, unilateral RuR microinjection into the CA₁ area of the hippocampus produced complex seizure behavior and wet-dog shakes (WDS). The i.p. administration of the serotonin receptor antagonist ketanserin markedly inhibited the WDS induced by i.h. RuR. In contrast, the i.h. injection of ketanserin and of the -aminobutyric acid (GABA) agonists 4,5,6,7-tetrahydroisoxazol[5,4-c]pyridin-3-ol (THIP) and baclofen together with RuR did not affect the frequency of WDS nor the seizure behavior. However, the i.h. injection of the GABA uptake blocker nipecotic acid, simultaneously with RuR, increased the frequency of WDS. The release of [³H]GABA, measured in synaptosomes of different cerebral structures of the rats injected i.p. with RuR, and in slices of the CA₁ area after i.h. injection of the dye, was not affected. Histological observations of the injected area showed a specific and intense staining of the somas of the CA₁ pyramidal neurons. It is concluded that the convulsant action induced by i.h. RuR microinjection is probably the result of an increased excitability of these CA₁ neurons, which is independent of any action on GABA release.