Malignant obstructive jaundice: treatment with external-beam and intracavitary radiotherapy

Eleven patients with obstructive jaundice from unresectable cholangiocarcinoma, metastatic porta hepatis adenopathy, or direct compression from a pancreatic malignancy were treated at the Stanford University Medical Center from 1978-1983 with an external drainage procedure followed by high-dose external-beam radiotherapy and by an intracavitary boost to the site of obstruction with Iridium192 (Ir192). A median dose of 5000 cGy was delivered with 4-6 Mv photons to the tumor bed and regional lymphatics in 9 patients, 1 patient received 2100 cGy to the liver in accelerated fractions because of extensive intrahepatic disease, and 1 patient received 7000 "equivalent" cGy to his pancreatic tumor bed and regional lymphatics with neon heavy particles. An Ir192 wire source later delivered a 3100-10,647 cGy boost to the site of biliary obstruction in each patient, for a mean combined dose of 10,202 cGy to a point 5 mm from the line source. Few acute complications were noted, but 3/11 patients (27%) subsequently developed upper gastrointestinal bleeding from duodenitis or frank duodenal ulceration 4 weeks, 4 months, and 7.5 months following treatment. Eight patients died--5 with local recurrence +/- distant metastasis, 2 with sepsis, and 1 with widespread systemic metastasis. Autopsies revealed no evidence of biliary tree obstruction in 3/3 patients. Mean survival time from initial laparotomy and bypass was 16.1 months, and from radiotherapy completion was 8.3 months. Evolution of radiation treatment techniques for biliary obstruction in the literature is reviewed. High-dose external-beam therapy followed by high-dose Ir192 intracavitary boost is well tolerated and provides significant palliation. Survival of these aggressively managed patients approaches that of patients with primarily resectable tumors.     

Brachytherapy for Head and Neck Cancer

Brachytherapy is a useful addition to external beam irradiation in the treatment of patients with head and neck cancer. Removeable implants are especially important in the treatment of neoplasms of the oral cavity (tongue, floor of mouth, buccal mucosa), orophrynx (tonsil, palate, and base tongue) and nasopharynx (intracavitary boosts). The most commonly used isotope for removable implants is irdium 192. The remote afterloading technique is applicable to both interstitial and intracavitary removable implants. Permanent placement of iodine 125 and palladium 103 radioactive sources may be performed for recurrent nasophayngeal malignancies, for palliation of accessible recurrences of primary sites in the oral cavity, oropharynx, and hypopharynx, or for cervical lymph node metastases. With brachytherapy, high radiation doses may be delivered to the volume of interest, while at the same time protecting adjacent normal tissues. Such implantations, if carefully performed, are effective, safe, and have a low risk of complications.     

Formation of “neo-cortex” in a congenital human teratoma

Summary A congenital human teratoma contained a neuroectodermal mass with architectonic features similar to those of the normal developing neo-cortex. Surrounding a central cavity, a germinal, an intermediate and a cortical zone were clearly distinguishable from innermost to outermost. Glial fibers coursed radially through the intermediate and cortical zones. In the cortical plate neuronal elements were oriented radially with an inside out gradient of differentiation. Mesothelial tissue covered the outer surfaces of the cortex. Over limited sectors a gap in the integrity of the meso-glial barrier were associated with neuroglial ectopias.The following points are of neurobiologic importance: the formation of the miniature cerebral cortex occurred in the absence of any influence of afferent subcortical fibers. The radial alignment of glial fibers between the germinal pseudostratified epithelium and the outer surface occurred only in sectors of the neuro-ectodermal mass where a neo-cortex was present, and may therefore have been a critical determinant in the formation of the cortical plate. The integrity of the outer glial mesenchymal barrier may be necessary for the normal arrangement of cortical neurons.     

Reelin mRNA expression during embryonic brain development in the chick

The expression of reelin mRNA was studied during embryonic brain development in the chick, by using in situ hybridization. Reelin was highly expressed in the olfactory bulb and in subpial neurons in the marginal zone of the cerebral cortex. In the diencephalon, the ventral division of lateral geniculate nuclei and perirotundal nuclei were strongly positive. High levels of expression were associated with some layers of the tectum and with the external granule cell layer of the cerebellum. A more moderate signal was detected in the septal nuclei, hyperstriatal fields, retina, habenular nuclei and hypothalamus, in some reticular nuclei of the mid- and hindbrain, and in the spinal cord. Little or no expression was observed in the cortical plate, Purkinje cells, or the inferior olivary complex. Comparison with reelin expression during mammalian and reptilian brain development reveals several evolutionarily conserved features that presumably define a homology. In addition, significant differences are noted, particularly in telencephalic fields. Most importantly, the developing chick cortex does not exhibit high levels of reelin expression in subpial Cajal-Retzius cells characteristic of the mammalian brain. These observations are compatible with an action of reelin on adhesion and/or of nucleokinesis at the level of target cells. They further suggest that, whereas the telencephalon of birds and archosaurs evolved primarily from dorsal ventricular ridge derivatives in which reelin is probably secondary, the increase in number of reelin-positive cells, and amplification of reelin expression played a key part in the evolution of the cortex in the synapsid lineage leading to mammals.     

Prenatal screening and diagnosis of congenital toxoplasmosis: a review of safety issues and psychological consequences for women who undergo screening

As part of the EUROTOXO initiative, this review focuses on the potential risks associated with prenatal testing for congenital toxoplasmosis. We first review the evidence on the risks of adverse events associated with amniocentesis, which is required for definitive diagnosis of toxoplasmosis infection in the fetus, and for which the most important risk is fetal loss. To date, there has been only one randomized trial to document risks associated with amniocentesis. This trial, which was conducted in 1986, reported a procedure-related rate of fetal loss of 1.0% (95% CI, 0.3-1.5). However, evidence from available controlled studies suggests that the pregnancy loss associated with mid-trimester amniocentesis may be lower.Potential psychological consequences of prenatal testing for congenital toxoplasmosis include parental anxiety due to false positive results and uncertainties related to prognosis of children with a prenatal diagnosis of congenital toxoplasmosis. Parental anxiety may be particularly important in screening strategies that include more frequent screenings, which may in turn entail substantial, and at times unnecessary, anxiety or other negative consequences for women and their families. These negative psychological outcomes should be balanced against the benefits of testing, which can allow women to make an informed choice regarding the pregnancy.     

Comment décider avec justesse,justice et équité ? Réflexion sur la décision en situation d'extrême prématurité: Deuxième partie : comment tendre vers une décision optimale ? Définition des conditions d'exercice de la décision

Extreme premature child's long-term prognostic is getting better and better known, and if a resuscitation procedure is possible at birth, it won't guarantee survival or a survival free of disability. Incertitude toward individual prognosis and outcome for those children remains considerable. In this field, we are at the frontier of medical knowledge and the answer to the question, "how to decide the ante and postnatal care" is crucial. This work is focused on this problematic of decision-making in the context of extreme prematurity. It attempts to deconstruct this concept and to explicit its stakes. Thus, with the support of the medical sources and of philosophical debates, we tried to build a decision-making procedure that complies with the ethical requirements of medical care, accuracy, justice and equity. This decision-making procedure is primarily concerned with the singularity of each decision situation and it intends to link it closely to the notions of rationality and responsibility.     

Comment décider avec justesse,justice et équité ? Réflexion sur la décision en situation d'extrême prématurité: Première partie : problématique de la décision dans le contexte de la prématurité extrême

Extreme premature child's long-term prognostic is getting better and better known, and if a resuscitation procedure is possible at birth, it won't guarantee survival or a survival free of disability. Incertitude toward individual prognosis and outcome for those childs remains considerable. In this field, we are at the frontier of medical knowledge and the answer to the question, “how to decide the ante and postnatal care?” is crucial. This work is focused on this problematic of decision making in the context of extreme prematurity. It attempts to deconstruct this concept and to explicit its stakes. Thus, with the support of the medical sources and of philosophical debates, we tried to build a decision-making procedure that complies with the ethical requirements of medical care, accuracy, justice and equity. This decision-making procedure is primarily concerned with the singularity of each decision situation and it intends to link it closely to the notions of rationality and responsibility.