Tumors of aqueduct of Sylvius. Presentation of 5 cases and review of the literature

The authors reports their experience of 5 cases of intra- and peri-aqueductal tumors. With the exception of 1 case, a subependymoma of the aqueduct discovered at autopsy in a 77 year old woman, the 4 other patients (2 females and 2 males) are relatively young (respectively 14, 23, 14 and 26) at the time when they presented with signs of chronically raised intracranial pressure due to a triventricular hydrocephalus. One patient presented with a partial Parinaud's sign, but the focal and long tract signs were conspicuously absent in the other patients. The diagnosis of a space occupying lesion in the tectum mesencephali or in the aqueduct could only be ascertained with the recent use of M.R.I. The radiological work-up of the cases suggest that theses lesions, presumably of glial origin, are very slowly growing tumors. Four patients have been treated for their symptomatic hydrocephalus, but no treatment of the tumor has been proposed, as the clinical state and the images remain remarkably stable. (Mean duration of follow up from the time of shunting = 3.7 years, extremes = 1.5-8 years). A review of the literature shows that not more than 48 cases of tumors of the aqueduct have been reported. Because of the small number of such observations, there are, until now, no precise informations on the management of such cases to decide if the patient will benefit of an open or stereotactic biopsy associated with radiotherapy or if one can rely on serial clinical and radiological examinations. Further information on the long term follow up is needed.     

Gastro-oesophageal reflux disease: Medical or surgical treatment? Report of an interactive workshop

Gastroesophageal reflux disease (GERD) is the most common disease of the upper gastrointestinal tract. With the introduction of proton pump inhibitors medical treatment of GERD has been significantly improved. However, the development of laparoscopic antireflux surgery resulted in an increasing interest of surgeons in this disease. An interactive meeting was organized in order to develop an agreement between gastoenterologists and surgeons regarding therapeutic decisions and this is the main topic of this paper.     

Severe acute myocardial infarction during a staphylococcal septicemia with meningoencephalitis

We report the first case of lethal intracranial haemorrhage complicating a treatment by rt-PA in a patient presenting with a simultaneous staphylococcal septicemia with meningoencephalitis and an acute myocardial infarction with cardiogenic shock. The presence of microvascular lesions in the central nervous system seems to be important risk factor for intracranial haemorrhage and we recommend extreme caution in the use of thrombolytic treatment in septicemic patients with acute myocardial infarction, particularly when neurological symptoms are present.     

Pathogenic role of P-selectin in experimental cerebral malaria: importance of the endothelial compartment

P-selectin is a leukocyte adhesion receptor expressed on the surface of activated platelets and endothelial cells. Its role in the pathogenesis of cerebral malaria was explored in a murine model of cerebral malaria. Infection of mice with Plasmodium berghei ANKA led to P-selectin up-regulation in brain vessels of cerebral malaria-susceptible mice but not of cerebral malaria-resistant mice. Treatment of susceptible mice with anti-mouse P-selectin mAb failed to prevent the development of the neurological syndrome. However, P-selectin-deficient mice infected with Plasmodium berghei ANKA had a cumulative incidence of cerebral malaria which was significantly reduced compared to wild-type animals (4.5% versus 80%, respectively), despite identical levels of parasitemia, platelet and leukocyte accumulation. To determine whether P-selectin on platelets and/or endothelium was responsible for the microvascular pathology, cerebral malaria was assessed in chimeric mice deficient in platelet or endothelial P-selectin, which were generated by bone marrow transplantation. Mice deficient only in endothelial P-selectin did not show any sign of cerebral malaria (vascular plugging, hemorrhages, or edema), while mice lacking only platelet P-selectin showed signs of cerebral malaria similar to that seen in wild-type mice. These results indicate that endothelial P-selectin plays an important role in the pathogenesis of cerebral malaria.     

Pituitary corticotroph adenoma with crooke’s hyalinization

The diagnosis of pituitary corticotroph adenoma relies on the demonstration of a loss of the normal feedback control of adrenocorticotropic hormone (ACTH) biosynthesis by cortisol. The marked variability in the degree of ACTH suppression by glucocorticoids in these tumors, however, greatly enhances the difficulty in distinguishing Cushing’s disease from other syndromes of glucocorticoid excess. To illustrate this variability, we describe the clinical, biochemical, and morphological characteristics of a pituitary corticotroph adenoma in a 63-year-old woman, who presented with symptoms of a sellar mass but did not initially have florid Cushing’s disease. Light and electron microscopy of the pituitary tumor showed a corticotroph adenoma with Crooke’s hyalinization of the tumor cells, characterized by the accumulation of keratin immunoreactive microfilaments similar to those observed in normal corticotrophs in the presence of excess glucocorticoids. This case illustrates an unusual clinical presentation that may be associated with pituitary corticotroph adenoma showing Crooke’s hyalinization.     

Sequence comparison of human and yeast telomeres identifies structurally distinct subtelomeric domains

We have sequenced and compared DNA from the ends of three human chromosomes: 4p, 16p and 22q. In all cases the pro-terminal regions are subdivided by degenerate (TTAGGG)n repeats into distal and proximal sub- domains with entirely different patterns of homology to other chromosome ends. The distal regions contain numerous, short (<2 kb) segments of interrupted homology to many other human telomeric regions. The proximal regions show much longer (approximately 10-40 kb) uninterrupted homology to a few chromosome ends. A comparison of all yeast subtelomeric regions indicates that they too are subdivided by degenerate TTAGGG repeats into distal and proximal sub-domains with similarly different patterns of identity to other non-homologous chromosome ends. Sequence comparisons indicate that the distal and proximal sub-domains do not interact with each other and that they interact quite differently with the corresponding regions on other, non- homologous, chromosomes. These findings suggest that the degenerate TTAGGG repeats identify a previously unrecognized, evolutionarily conserved boundary between remarkably different subtelomeric domains.