Nitric oxide synthase in neuroepithelial brain tumors

Immunohistochemical investigation of NO-synthase in brain astrocytic tumors revealed intense reaction in many tumor cells as well as direct correlation in the intensity of reaction and the degree of tumor anaplasia. Grade I astrocytomas did not show immunoreactivity in contrast to high anaplastic tumors where many cells had positive reaction with a different degree of intensity. Positive immunoreaction was shown in many giant cells. Small cell glioblastomas and oligodendrogliomas were immunonegative. There was a direct correlation between NO-synthase expression and glial fibrillar acidic protein.     

The efficacy of recombinant vaccines against hepatitis B and the results of their use in a schedule for pediatric prophylactic inoculations

The results of field clinical trials of Russian and American yeast vaccines against hepatitis B are presented. The study revealed that both vaccines were faintly reactogenic, safe and exhibited high immunological activity. After the full course of immunization following the schedule 0-1-2 months 92.5% and 97.5% of patients receiving, respectively. Russian vaccine "Combiotech" and American vaccine "H-B-Vax II" were found to have specific antibodies. The maximum effect was registered when the vaccines were introduced according to the schedule 0-1-6 months. Seroconversions were observed in 97.5% and 100% of the vaccinees receiving the Russian and American vaccines respectively, in the latter case the highest antibody level being observed. The use of the vaccines within the prophylactic immunization schedule showed that antibodies to hepatitis B appeared in immunized children in 93-100% of cases. Seroconversion indices and the levels of antibodies to diphtheria, tetanus, poliomyelitis and measles were statistically significant and were the same in children receiving only the vaccines according to the immunization schedule and in children immunized, in addition to these vaccines, against hepatitis B.     

Primary spinal T-cell rich B-cell lymphoma: a case report

During my nursing career, I remember constantly being aware of patients who needed some emotional help--those who were frightened about a forthcoming operation, those who were shocked and despairing after being given their diagnosis and prognosis, others who were down in the dumps because they couldn't go home as soon as they had hoped. There were also the 'ward clowns' who tried to make everyone laugh with their good humour and little pranks, yet felt no less anxious, worried or depressed than anyone else. Patients seem to fit into categories: the nervous ones, the depressives, the jovial types, the moaners, those who demand attention and those who shun it. I feel sure that every nurse has noticed the different 'types' of people who fill hospital beds-ordinary people who seem to take on a new persona as soon as they get into their pyjamas and become a 'patient'. Somehow, their identity gets folded up and put away in their locker along with their outdoor clothes and other reminders of the outside world.     

Determination of DNA damage in F344 rats induced by geometric isomers of tamoxifen and analogues

The transformation of Trypanosoma cruzi epimastigotes to mammal-infective metacyclic trypomastigotes (metacyclogenesis) can be performed in vitro under chemically defined conditions (TAU 3AAG medium). During this process, changes in the nature of cell surface sugar composition and sugar distribution was evaluated using FITC and gold-labeled lectins and observed by flow cytometry and transmission electron microscopy. The pattern of labeling with the lectins from Triticum vulgaris (WGA), Arachis hypogaea (PNA), Limax flavus (LFA), Canavalia ensiformis (Con-A), and Ricinus communis (RCA-I) significantly changed during the metacyclogenic process. The results obtained are discussed in relation to the role played by T. cruzi cell surface carbohydrate residues on the process of parasite-host cell interaction.     

Nucleotide variation in the triosephosphate isomerase (Tpi) locus of Drosophila melanogaster and Drosophila simulans

DNA sequence variation in a 1.1-kb region including the coding portion of the Tpi locus was examined in 25 homozygous third-chromosome lines of Drosophila melanogaster, nine lines of Drosophila simulans, and one line of Drosophila yakuba. Our data show that the widespread allozyme polymorphism observed in cosmopolitan D. melanogaster is due to a glutamic acid substitution occurring in a phylogenetically conserved lysine that has been identified as part of the "hinged-lid" active site of the enzyme. This observation suggests that the replacement polymorphism may have important functional consequences. One replacement polymorphism was also observed in D. simulans, although its functional relevance is more difficult to assess, since it affects a site that is not strongly conserved. This amino acid change in D. simulans is associated with a single lineage possessing seven unique silent substitutions, which may be indicative of balancing selection or population subdivision. The absence of fixed amino acid differences between D. melanogaster and D. simulans and only a single difference with D. yakuba suggests that triose phosphate isomerase is under strong functional constraint. Silent variation is slightly higher for D. melanogaster than for D. simulans. Finally, we outline the general lack of evidence for old balanced polymorphisms at allozyme loci in D. melanogaster.     

Analysis of the association of a heat shock protein70-1 gene promoter polymorphism with myocardial infarction and coronary risk traits

In 12 depressed inpatients referred for bilateral electroconvulsive therapy (ECT), each patient was titrated at the first treatment session by using an ascending method-of-limits procedure with a step-wise increase in pulse frequency (frequency titration) or train duration (duration titration). At the second treatment session, seizure threshold was redetermined by using the method (frequency or duration titration) not used at the first treatment. Frequency or duration was maintained at the lowest level when the other parameter was titrated. Seizure threshold was significantly lower with duration titration (mean, 90 mC; SD, 27.3) than frequency titration (mean, 114 mC; SD, 35.6; p = 0.03). On average, patients in the duration-titration group required 1.2 (SD, 0.6) subconvulsive stimulations before a seizure was elicited, and patients in the frequency-titration group required 1.7 (SD, 0.9) subconvulsive stimulations before a seizure was elicited, a nonsignificant difference. These findings suggest that to elicit a seizure during ECT, increasing train duration may be slightly more efficient than increasing frequency. Basic and other clinical research findings indicate that increasing pulse width may be an inefficient way to elicit a seizure. Therefore the following sequence in the determination of seizure threshold is worth considering when using dose-titration or related techniques: the train duration should be increased first before increasing pulse frequency, and the decision to increase pulse width should be reserved for patients who do not seize at the maximal duration and frequency settings. Further empiric research is needed to establish the utility of this approach.     

Development of a method for creating a colony of Macaca mulatta, free of herpes B virus infection

To form the colony of monkeys, free of herpes B virus, the serological study was made with the aim of finding out the carriers of this virus. 482 rhesus macaques (Macaca mulatta) from the Adler monkey house were examined for the presence of antibodies to herpes B virus by the method of point immunoblotting with the use of Herpes virus simiae as antigen. The contamination of monkeys in different open-air cages varied from 12.5% to 92%. In different age groups, it was 27% in nonpubescent monkeys (49 out of 182 animals), 55% in adolescent monkeys (55 out of 99), 73% in pubescent monkeys (131 out of 179) and 95% in monkeys over 15 years (21 out of 22 animals). 9 groups of rhesus macaques (comprising altogether 81 animals), free of herpes B virus, were selected. The monkeys were repeatedly tested within a year; after that 10-17% of formerly seronegative monkeys were rejected and removed from the selected group. After the third testing 2.5% more of the animals were found to have seroconversion. The colony of rhesus macaques thus created exists at present. The animals are subjected to constant serological observation.     

Langmuir films from antibodies based on amphiphilic polyelectrolytes

A technique for forming Langmuir films from antibodies based on an amphiphilic polyelectrolyte was developed. The physicochemical and immunochemical properties of the Langmuir films obtained were studied. The interaction of HBsAg with the films was found to be described by a model with one binding site, whereas that of HBsAg with antibodies adsorbed on a polystyrene plate, by a model with a positive cooperativity. The use of the novel Langmuir films from antibodies increases the sensitivity of the immunoenzyme assay.     

Management of nasopharyngeal and oropharyngeal stenosis in children

Nasopharyngeal stenosis and oropharyngeal stenosis are rare and challenging problems in the pediatric population. The most common etiology is currently the surgical trauma associated with adenotonsillectomy. Stenosis can vary from a thin band to a complete obstructing cicatrix. Presenting symptoms range from mild hyponasal speech to severe airway obstruction. We present a series of eight children with varying degrees of stenosis and associated symptoms. Choice of treatment varied with the severity of disease. In our series, successful interventions included triamcinolone acetonide injection, lysis of adhesions, rotational and advancement mucosal flaps, and jejunal free flap. Preoperative evaluation and individualized surgical repair are essential for successful treatment.     

Conditioned defensive reflex in the edible snail (molecular-genetic aspects)

The proliferation of glioma cells requires cholesterol, which could be provided by synthesis within the cells or by uptake of cholesterol esters in particles of Low Density Lipoprotein (LDL). Cholesterol esters and cholesterol were therefore analysed in human glioma tissue, its surrounding areas and serum from 40 patients. The analyses revealed an increased concentration of cholesterol esters up to 100 times (0.1-10 mumol/g) in both tumour-tissue and surrounding areas compared with control material (< 0.1 mumol/g). The analyses also demonstrated that cholesterol esters in tumour tissue eminated mainly from serum. The cholesterol concentrations were significantly lower in tumour tissue compared with surrounding areas as expected. These results indicate that tumour cell proliferation utilises serum derived cholesterol esters presumably carried by LDL particles.