Massive symptomatic subependymoma of the lateral ventricles: case report and review of the literature

Subependymomas are benign intraventricular tumors with an indolent growth pattern, which are usually asymptomatic, and most commonly occur in the fourth and lateral ventricles. When symptomatic, subependymomas often obstruct critical portions of the cerebrospinal fluid (CSF) pathway, causing hydrocephalus, and range from 3 cm to 5 cm in size. We report a case of an unusually massive subependymoma of the lateral ventricles treated with subtotal resection, ventriculoperitoneal shunt, and post-surgical radiation. The clinical course, radiographic and pathologic characteristics of this massive intraventricular subependymoma are discussed, as well as the differential diagnosis of lateral ventricular masses and a review of the literature concerning subependymomas.     

Surgical treatment of the tracheal scarry stenoses

Surgical policy for scarry tracheal stenosis is analyzed. In the years 1998-2003 in the clinic there were 32 circular resections of the trachea. More than 5 cm of the tracheal segment was ablated in 15 of the cases. The initially performed endoscopic treatment including bougieurage and trachea endoprosthesis was carried out in 19 patients. The immediate and long-term results were satisfactory in all cases that allowed the authors to recommend the one-step circular resection of the trachea as a method of choice for the treatment of lengthy scarry stenoses of the trachea.     

Double disposition of the major vessels from the right ventricle of the Fallot tetralogy type

Forty-six patients with double disposition of the major vessels from the right ventricle in combination with stenosis of the pulmonary artery, in sub-aortal and bi-committed defects of the interventricular septum have undergone biventricular intraventricular correction. The most specific and accurate anatomic characteristics were: 1) position of the major vessels (particularly side-to-side); 2) location of two and a part of the third aortal sinuses above the right ventricle; 3) bilateral cone; 4) absence of aorto-mitral contact; 5) location of valves of aorta and pulmonary artery on the same level. One (2,2%) patient died during surgery due to progressed cardiac insufficiency. One (2,5%) patient died 2 years after radical correction of the defect due to progressive dysfunction of the right ventricle.     

Early and late results of the intravascular treatment of cerebral aneurysms with a detachable balloon-catheter

The paper analyzes the outcomes of intravascular treatment in 87 patients with cerebral aneurysms with separable a balloon catheter with a valve device. In the cold and hemorrhagic periods, mortality rates were 6.4 and 40%, respectively. The postoperative follow-ups lasted 1 to 17 years (mean 7.7 years). Recurrent subarachnoidal hemorrhage (SAH) was noted in 6.5% of cases, with not earlier than 4.5 years after intervention. The remaining patients (even with partial aneurysmal occlusion) had no recurrent SAH.     

Prevention of neural tube defects with folic acid

Neural Tube Defects (NTD's) include a large number of congenital malformations produced when the open neural tube presents a very early stages in the development of the human embryo fails to close on or before the first month post conception. NTD's are considered to be one of the most common forms of malformations with varying degrees depending of genetic and environmental conditions. The studies prove that the additional taken of folic acid plays an important role against the NTD's. Numerous studies prove this "B" vitamin has an important protective effect not only for the recurrence of NTD's, but for new cases too. In light of these, in 1992 the US Public Health Services issued the recommendation that all women in child-bearing age should consume at least 0.4 mg (400 micrograms) of folic acid daily.     

Computer visualisation of the active site of monoamine oxidase-A by means of selective inhibitors

Computer visualisation of the active site of monoamine oxidase (MAO) is based on an assumption that the specific and reversible interaction of a ligand (substrate or inhibitor) with the substrate-binding region of the active site requires shape complementarity. The size of the ligand must allow its accommodation at the substrate-binding region. Analysis of the MAO-inhibitory activity of rigid analogues of isatin and pirlindole revealed a dependence between three-dimensional linear sizes of these molecules and the efficacy of inhibition of both MAO-A and MAO-B. However, flexible molecules did not exhibit any dependence between linear sizes and MAO-B inhibitory potency, possibly because they folded into compact structures could fit into the substrate-binding pocket of MAO-B. 'Moulding' of the substrate/inhibitor binding region by superposition of effective MAO-A inhibitors from various groups of chemicals allowed the shape of substrate/inhibitor binding region to be visualised. 'Removal of contents' from this mould yielded a cavity, which corresponded to the shape of substrate/inhibitor binding region. Such cavity can be used to evaluate the most probable positions known inhibitors take in binding to it. The docking procedure can also be used for searching molecular databases for new inhibitors. Pilot experiments revealed that relatively rigid compounds, which did not fit to this cavity, were poor inhibitors of MAO-A.     

Tumor-associated hetero-organic antigens as markers of deranged cell differentiation and malignancy

We used rat liver tissue slices and isolated hepatocytes to demonstrate that single exposures to a "weak" carcinogen 4-dimethylaminoazobenzol (DAB) or to a "strong" one, such as N-diethylnitrosamine (DENA), cause identical antigenic restructuring to occur. It presented as formation of membranous heteroorganic antigens of renal origin on hepatocyte surfaces. Antigens were associated with Zajdela's hepatoma; their synthesis lasted longer after exposure to DENA. They, however, were not identified in intact rat liver. Their synthesis, following single exposure, was assayed immunocytofluorimetrically. It is suggested that the antigens be used as markers of cell dysdifferentiation and malignancy and testing substances for carcinogenicity.     

Strategy of computer-aided drug design

Modern strategies of computer-aided drug design (CADD) are reviewed. The task of CADD in the pipeline of drug discovery is accelerating of finding the new lead compounds and their structure optimization for the following pharmacological tests. The main directions in CADD are based on the availability of the experimentally determined three-dimensional structure of the target macromolecule. If spatial structure is known the methods of structure-based drug design are used. In the opposite case the indirect methods of CADD based on the structures of known ligands (ligand-based drug design) are used. The interrelationship between the main directions of CADD is reviewed. The main CADD approaches of molecule de novo design and database mining are described. They include methods of molecular docking, de novo design, design of pharmacophore and quantity structure-activity relationship models. New ways and perspectives of CADD are discussed.