High salinity wastewater treatment.

The shock effect, survival and ability of activated sludge to acclimatize to wastewater containing different concentrations of NaCl and Na2SO4 were investigated under laboratory conditions. To accomplish this, the potential penetration of a sewage system by seawater as a consequence of storm surge flooding was simulated. The experiments were conducted using activated sludge taken from the aeration tank of a communal wastewater treatment plant and adding different concentrations up to 40 g/L of NaCl and 4.33 g/L of Na2SO4. The effects of salinity on the activated sludge were monitored for 5 weeks based on the values of pH, dissolved oxygen, total suspended solids, volatile suspended solids, sludge volume, sludge volume index, electrokinetic potential, respirometric measurements and enzymatic activity. The addition of salt sharply reduced or completely inhibited the microbial activity in activated sludge. When salt concentrations were below 10 g/L NaCl, microorganisms were able to acclimatize in several weeks and achieve the same initial activity as in raw sludge samples. When the salt concentration was above 30 g/L NaCl, the acclimatization process was very slow or impossible.

Application of the dual-tagging gene trap method combined with a novel automatic selection system to identify genes involved in germ cell development in Drosophila melanogaster.

The passage of highly specialized germ cells to future generations is essential for the maintenance of species. To date, conventional genetic screens identified relatively few genes that are involved in germ cell development. We aimed to identify germ line specific genes on the X chromosome of Drosophila melanogaster by the application of a new method: the dual-tagging gene-trap system (GT). A modified version of the gene-trap element was used in our experiments and the resulting insertional mutants were screened for grandchild-less phenotype with the help of the attached-X system and a sensitized genetic background developed in our laboratory. Among the 800 insertions mapped to the X chromosome 33 new mutations were identified that exhibited grandchild-less phenotype, 6 gave visible phenotype and 12 were conditional lethal. The cloning of a selected group of the 33 lines showing grandchild-less phenotype confirmed that we have identified new candidates for genes involved in germ cell development. One of them named pebbled (peb) is discussed in details in this paper. Finally, we also describe a novel automatic selection system developed in our laboratory which enables the extension of the GT mutagenesis to the autosomes.

The Trithorax-mimic allele of Enhancer of zeste renders active domains of target genes accessible to polycomb-group-dependent silencing in Drosophila melanogaster.

Two antagonistic groups of genes, the trithorax- and the Polycomb-group, are proposed to maintain the appropriate active or inactive state of homeotic genes set up earlier by transiently expressed segmentation genes. Although some details about the mechanism of maintenance are available, it is still unclear how the initially active or inactive chromatin domains are recognized by either the trithorax-group or the Polycomb-group proteins. We describe an unusual dominant allele of a Polycomb-group gene, Enhancer of zeste, which mimics the phenotype of loss-of-function mutations in trithorax-group genes. This mutation, named E(z)(Trithorax mimic) [E(z)(Trm)], contains a single-amino-acid substitution in the conserved SET domain. The strong dominant trithorax-like phenotypes elicited by this E(z) allele suggest that the mutated arginine-741 plays a critical role in distinguishing between active and inactive chromatin domains of the homeotic gene complexes. We have examined the modification of E(z)(Trm) phenotypes by mutant alleles of PcG and trxG genes and other mutations that alter the phosphorylation of nuclear proteins, covalent modifications of histones, or histone dosage. These data implicate some trxG genes in transcriptional repression as well as activation and provide genetic evidence for involvement of histone modifications in PcG/trxG-dependent transcriptional regulation.

Transvection in the Drosophila Abd-B domain: extensive upstream sequences are involved in anchoring distant cis-regulatory regions to the promoter.

The Abd-B gene, one of the three homeotic genes in the Drosophila bithorax complex (BX-C), is required for the proper identity of the fifth through the eighth abdominal segments (corresponding to parasegments 10-14) of the fruitfly. The morphological difference between these four segments is due to the differential expression of Abd-B, which is achieved by the action of the parasegment-specific cis-regulatory regions infra-abdominal-5 (iab-5), -6, -7 and -8. The dominant gain-of-function mutation Frontabdominal-7 (Fab-7) removes a boundary separating two of these cis-regulatory regions, iab-6 and iab-7. As a consequence of the Fab-7 deletion, the parasegment 12- (PS12-) specific iab-7 is ectopically activated in PS11. This results in the transformation of the sixth abdominal segment (A6) into the seventh (A7) in Fab-7 flies. Here we report that point mutations of the Abd-B gene in trans suppress the Fab-7 phenotype in a pairing-dependent manner and thus represent a type of transvection. We show that the observed suppression is the result of trans-regulation of the defective Abd-B gene by the ectopically activated iab-7. Unlike previously demonstrated cases of trans-regulation in the Abd-B locus, trans-suppression of Fab-7 is sensitive to heterozygosity for chromosomal rearrangements that disturb homologous pairing at the nearby Ubx locus. However, in contrast to Ubx, the transvection we observed in the Abd-B locus is insensitive to the allelic status of zeste. Analysis of different deletion alleles of Abd-B that enhance trans-regulation suggests that an extensive upstream region, different from the sequences required for transcription initiation, mediates interactions between the iab cis-regulatory regions and the proximal Abd-B promoter. Moreover, we find that the amount of DNA deleted in the upstream region is roughly proportional to the strength of trans-interaction, suggesting that this region consists of numerous discrete elements that cooperate in tethering the iab regulatory domains to Abd-B. Possible implications of the tethering complex for the regulation of Abd-B are discussed. In addition, we present evidence that the tenacity of trans-interactions in the Abd-B gene may vary, depending upon the tissue and stage of development.

Fetal movements in human pregnancies in the third trimester.

Fetal movements (FM) were measured using a real-time B-scan method in 50 women in the third trimester. One hundred ninety-five observations were made. The number of FM per 20-minute observation period was similar in normal, diabetic, and hypertensive pregnancies and in patients with placenta previa, but was significantly lower in patients with Rh isoimmunization and an affected fetus. The number of FM did not vary with gestational age, mode of delivery, or birth weight and was significantly increased in patients either with a reactive nonstress test (NST) or in the presence of fetal breathing movements (FBM). Fetal movements were absent before delivery in 4 patients: In 3, the fetus died in utero and in the other a positive contraction stress test (CST) was observed. Conversely, in 2 other fetuses who died in utero, FM were observed during the last examination before death. In both, the cause of fetal death was related to an acute change. No relationship between FM and neonatal death was observed. These data suggest FM monitoring may be helpful in evaluating antepartum fetal condition.

Further experience with the fetal biophysical profile.

At Los Angeles County/University of Southern California Medical Center, the authors performed biophysical profile testing on 186 fetuses within one week of delivery. One component of the biophysical profile is the nonstress test. The other four components are fetal parameters observed with real-time ultrasonography: fetal breathing movements, fetal movements, fetal tone, and amniotic fluid volume. Clinicians managed the patients on the basis of the nonstress test result, and the authors did not report the other biophysical profile results. Measures of outcome included perinatal mortality, fetal distress in labor, low five-minute Apgar score, and birth weight small for gestational age. Results indicate that fetal biophysical parameters other than the response, or lack of response, of the fetal heart rate to fetal movements may have predictive value in assessing the state of fetal health. In the future, real-time ultrasonography may prove to be a reliable adjunct to antepartum electronic fetal heart rate monitoring.

Myo-inositol-1-phosphate synthase in different Streptomyces griseus variants.

The activity of myo-inositol-1-phosphate synthase (MIPS, EC 5.5.1.4.) from streptomycin producing and non-producing strains of Streptomyces griseus was measured during the life cycle on different culture media. The activity varied in the different S. griseus variants and depended on the time of cultivation and the composition of the culture medium. Strains characterized by low MIPS levels are also low streptomycin producers. The enzyme is unstable. It loses 70% of its activity in the crude extract after 18 h at 0 degree C. (NH4)2SO4 and DMSO (dimethyl sulfoxide) in 20% solution are suitable stabilizing agents, the loss of activity being only 10% in 0.5 M (NH4)2SO4 solution during 24 h. With the applied purification procedure the specific activity of the enzyme was increased 23-fold. According to preliminary estimations, its molecular mass (Mr) is about 216 kDa with a pH optimum of 8.3 and Mg2+-dependent enzyme activity.

Characterization of human gliomas by a monoclonal antibody both on tissue culture and paraffin-embedded sections.

A monoclonal antibody designated OITIC3-11 was produced against GFAP positive human glioblastoma multiforme tumour cells. The specificity of the monoclonal antibody was tested on different types of human brain tumours and on normal adult brain both on tissue cultures and paraffin-embedded sections. The OITIC3-11 monoclonal antibody reacted with 16 of 18 malignant and 1 of 6 benign gliomas but did not react with meningioma, pituitary adenoma, metastatic brain tumours and normal adult brain tissue.

Apoptosis and p53 expression in human gliomas.

Twenty-five human gliomas of different histological grade and type were studied for p53 expression by immunohistochemistry and for apoptosis using ApopTag method. p53 expression (percentage of positive cells) was highest in anaplastic astrocytomas, followed by low grade astrocytomas and surprisingly in glioblastomas. Granular cytoplasmic p53 positivity appeared in 4/5 low grade oligodendroglioma and in 2/5 low grade mixed oligoastrocytomas. The means of apoptosis index in the different tumor types ranged between 0.8 and 11.5 with the highest values in anaplastic astrocytoma and glioblastomas. Although the number of cases per group were relatively low and the individual vales showed differences it seems that p53 expression is related to the biological aggressiveness of gliomas. It is also suggested that high level of apoptosis in malignant glioma could represent a p53 independent pathway.

Voltammetric determination of copper in water samples digested by ozone.

The applicability of ozone as a digestion agent in voltammetric trace metal analysis of water samples was investigated. It was shown that ozone efficiently destroys dissolved organic matter, causing a significant decrease of the concentration of surface active substances in the sample, thus enabling voltammetric measurements. Ozonolysis times of 30 and 60 min were sufficient for the treatment of river water and biologically treated wastewater samples, depending on their organic load, prior to voltammetric determination of copper using a solid gold electrode.

Chitosan for the collection from seawater of naturally occurring zinc, cadmium, lead and copper.

Anodic stripping voltammetry with a composite graphite-mercury electrode was applied in order to demonstrate that chitosan can collect naturally occurring zinc, cadmium, lead and copper from sea-water, with high yields. Chitosan columns (15 x 10mm) can be used to preconcentrate trace metals from 3 1. of sea-water; the four elements can be selectively eluted with electrolytes suitable for conventional polarographic determinations. The method can find application in sea-water pollution survey and detection.

BCNU-DBD (Dibromodulcitol) chemotherapy of recurrent supratentorial anaplastic astrocytomas and glioblastomas.

Our aim was to investigate the effect of BCNU and DBD combined chemotherapy in patients with recurrent malignant gliomas. Forty-six patients were treated with combined chemotherapy. Out of 26 patients with anaplastic astrocytomas 11 were originally low-grade where no postoperative radiotherapy was applied. Fifteen patients with anaplastic astrocytoma responded well to the chemotherapy and 9 survived longer than one year. Median survival time was 14 months. Complete response of recurrent glioblastoma did not occur and only 4 patients survived longer than one year. Median survival time was 7 months. Ratio of patients with response and stable disease was 70 and 55 %, respectively. BCNU and DBD combination proved to be an effective combination for recurrent malignant gliomas. It was remarkable that patients' survival with primary or secondary lower grade astrocytoma were significantly longer than that in patients with glioblastomas. Treatment of lower grade tumors, even at their malignant recurrences is promising.

Comparative studies on the distribution of heavy metals in the oceans and coastal waters.

Results of our investigations during the last five years are summarized. The concentrations of Cd, Pb and Cu have been determined in coastal areas of the Western Mediterranean and the North Sea, reflecting the influence of the pollution sources along the shore line. Deep sea water and surface water sample from the Pacific, Atlantic, Mediterranean and Arctic Sea have been analyzed for Cd, Pb, Cu and at some stations also additionally for Ni, Co. It is demonstrated that concentration levels of surface and deep sea waters may differ significantly in diverse oceans. The same is valid to a greater extent for coastal waters affected particularly by anthropogenic input that can be dispersed by tidal currents. Applying reliable sampling methods and the voltammetric determination procedure in particular suitable for heavy metals at the trace level, significant contributions to a consistent data basis for the distribution of heavy metals in the sea could be achieved.

Improved signals ratio resolution method by optimization of resolution function--simultaneous determination of Cu(II) and Cd(II) in water samples.

From an ecological and economical point of view, it is important to design analytical procedures for monitoring heavy metals in the environment and industrial processes in a way to minimize the use of hazardous reagents and reduce the analysis time. In this paper, a well-known dithizonate extraction-based method for the determination of many metal ions was improved by using chemometrical selectivity of the strongly overlapped spectra of copper and cadmium dithizonates in CCl4 for their simultaneous determination from a single extraction at pH 10. The individual absorption spectra, having absorption maxima difference of only 20 nm, were separated, and the metal ions were quantified by using an improved procedure for optimizing the resolving function in a recently proposed signals ratio method. The procedure consists of using many different resolving functions and plotting the difference of the mean of absolute and nonabsolute mean values of pseudosignals [PDMMV (PS)] against analyte concentrations obtained with each of the resolving functions, thus obtaining 2 straight lines having intersections that give a unique and reliable value of the unknown concentration of the individual analyte in mixture giving strongly overlapped spectra. In this way, the main drawback of the signals ratio resolution method, that is, the visual estimation of optimal resolving function, is eliminated. The proposed parameter, PDMMV (PS), was tested by using both simulated and experimental spectra. Copper was determined in the mixture with ca 20-fold excess of cadmium, and cadmium was determined in ca 10-fold excess of copper at submicromolar concentration levels.

[Diagnostic and therapeutic possibilities in adult malignant gliomas]. / Felnóttkori malignus gliomák diagnosztikai és terápiás lehetóségei.

Despite of the recent advances in diagnostic and therapeutic techniques the outcome of patients with malignant gliomas remains poor. The most widely used classifications and management of supratentorial gliomas are reviewed focusing on the chemotherapeutic possibilities. More accurate diagnosis and new therapeutic approaches will be available with the results of immunological studies. With the help of genetical experiments the development and malignant transformation of the gliomas will come to light. The gene therapy seems to be promising even in case of malignant glioma.

[The role and importance of CT-guided stereotaxic brain biopsy in neurosurgery. Experiences with 523 cases]. / CT vezérelt stereotaxiás agyi biopszia jelentösége és szerepe az idegsebészetben. Tapasztalataink 523 eset kapcsán.

Between 1989 and 1996, 523 stereotactic biopsies of different intracranial lesions were performed at our institution. In 96.3% of the cases accurate histological diagnosis was made. In 59 cases the drainage of the abscess or cyst was carried out. In 48 cases the lesion was axial, in 27 parasellar, 7 pineal and 37 infratentorial. In the rest of the cases the lesion was in the supratentorial hemispheres. Transient neurological deficits were observed in 3.4% of the cases and craniotomy with haematoma evacuation had to be carried out in one case following the biopsy. There was no mortality associated with the interventions in our material. Our experience supports that CT guided biopsy is a safe and efficient method for obtaining histological diagnosis in different intracranial lesions and showed to be very useful in planning te appropriate treatment for each patient.

Hydrochemical characterization of arsenic contaminated alluvial aquifers in Eastern Croatia using multivariate statistical techniques and arsenic risk assessment.

Multivariate statistical analyses, cluster, factor and discriminant analyses, were used to estimate spatial variations in groundwater chemistry in Eastern Croatia and to identify the main geochemical processes responsible for high arsenic (As) concentrations in the groundwater analyzed. Cluster analysis revealed five different groups of sampling sites linked with groundwater evolution, hydrochemical characteristics and different As content in the groundwater. Two-model factor analysis explained around 50% of total variance of the data sets and enabled identification of the different geochemical processes responsible for higher As concentrations, i.e. decoupled Fe and As reduction and desorption. Using discriminant analysis, a three-parameter discriminant function was derived: electrical conductivity, nitrate and bromide, which yielded highly accurate classification of the samples according to the concentration of As as As-safe (<10µg/L) and As contaminated (>10µg/L). A health risk assessment model was applied to calculate cumulative exposure to As as well as toxic and carcinogenic risks resulting from drinking raw groundwater contaminated by As in Eastern Croatia. Although the results obtained indicate that adverse health effects could be observed among the residents of the villages in which raw groundwater with higher As concentrations has been used, there are no reported cases of arsenicosis.

Re-operations of supratentorial anaplastic astrocytomas.

Results of re-operations of 99 adult patients with recurrent supratentorial lobar glioblastomas (60 patients) and anaplastic astrocytomas (39 patients) have been reviewed. In all cases both surgical interventions were performed at the same institute. Age of patients with glioblastoma varied between 19 and 64 and with anaplastic astrocytoma between 21 and 68 years, with a mean value of 48 and 36 years, respectively. The median interval between the first and second operations was 47 weeks for patients with glioblastoma and 83 weeks with anaplastic astrocytoma. The mortality rate of the re-operations was 3%. Following re-operation radio- and/or chemotherapy was applied in most of the cases. Median survival time after re-operation was 18.5 weeks in patients with glioblastoma and 55 weeks with anaplastic astrocytoma. Survival curves were calculated according to Kaplan-Meier method and for statistical evaluation the generalized Wilcoxon test and multiple linear regression method were used. Histologically lower grade tumour at the first operation and longer interval between the two operations proved to influence positively and dedifferentiation of the primary tumour negatively the survival time.