Prevention of neural tube defects by folic acid - awareness among women of childbearing age in Slovakia.

BACKGROUND: Folic acid deficiency plays a central role in the aetiology of many congenital anomalies including neural tube defects. Protective effect of folic acid on embryo may be acquired only if taken periconceptionally. OBJECTIVES: The aim of the study was to investigate the awareness about folic acid among women of childbearing age in Bratislava, Slovakia. METHODS: There were 130 respondents involved in the research (106 pregnant women, 24 female students of medical faculty). Using questionnaire we acquired following data: pregnancy details, interest in diet before and during pregnancy, recommendations regarding nutrition and supplementation pre- and post-conception, knowledge about folic and other acid in 2004 and 2009. RESULTS: More than half of the respondents knew the sources of folic acid. The interest in the nutrition facts of the food dropped from 91 % to 58.5 %. The number of pregnant women advised about correct nutrition and folic acid supplementation before and during pregnancy increased from 16 % to 37 %. Planning the next gravidity with folic acid supplementation became greater than 21 % (38 % in 2009). Nevertheless, only 46 % of these women believed that proper food content with folic acid may prevent congenital anomalies. In a group of students planning to take folic acid periconceptionally the number raised up to 62.5 %. CONCLUSION: The results revealed low knowledge about the effect of folic acid on developing embryo among women of childbearing age. Effective intervention programs are needed with the aim to improve periconceptional intake of folic acid in 2004 and 2009. The results in both periods show low knowledge about this essential vitamin (Tab. 1, Fig. 8, Ref. 31).

New insights into the role of NF1 in cancer.

NF1 proteins are a family of transcription factors that act either as repressors or as activators. Functional studies indicate that NF1 participate in signaling pathways that regulate cell viability, proliferation and differentiation. Participation in regulation of genes important for tumor progression and metastasizing suggests a potential value of NF1 as a prognostic factor for certain types of cancer.

[Epidemiology of neural tube defects]. / Epidemiológia defektov neurálnej rúry.

INTRODUCTION: Neural tube defects represent group of congenital diseases with relatively high incidence in population. Authors assess world and Slovak literature and statistical facts about the epidemiology of NTD and compare them with their own results of retrospective study performed in Children's Hospital, Bratislava. MATERIALS AND METHODS: List of patients consists of 250 children (106 boys, 144 girls): X-ray images showing lumbo-sacral part of vertebral column were evaluated retrospectively (X-ray of native abdomen, urological tract or skeleton). Authors assessed presence or non-presence of spina bifida on images, without relation to age, gender or diagnosis of patients. RESULTS: From the total number of 250 radiograms, 72 findings were positive (36 boys and 36 girls), 160 images were negative, 18 were unsuitable for evaluation due to low image quality. The highest diagnostic capture was from urological images - 40% of all positive findings. Incidence of spina bifida in Children's Hospital concluded from X-ray images is quite high - 28.8%. CONCLUSION: According to the data from National Centre of Health Statistics the incidence of open caudal neural tube defects in Slovakia is under 5 per 10 000 live-born children at present time. However the occurrence of occult spina bifida is not known exactly. The high rate of spina bifida presented herein (28%) can be caused by relatively low number of evaluated radiograms. Also the fact that children were not only healthy ones and data were obtained from the western part of Slovakia as well. In conclusion we can say that after accidental finding of caudal neural tube defect consecutive diagnostics should be performed in clinical positive cases - genetics, MRI and consultation with specialists to decide for the optimal follow up of the patient.

Mutation in the beta subunit of F ATPase allows Kluyveromyces lactis to survive the disruption of the KlPGS1 gene.

The petite-negative yeast Kluyveromyces lactis does not tolerate the loss of phosphatidylglycerol (PG). We demonstrate that the lethality of PG loss is suppressed in strains carrying a mutation in the beta subunit of F(1) ATPase (mgi1-1). Phenotypic characterization shows that the strain lacking the phosphatidylglycerolphosphate synthase gene (KlPGS1) is able to grow only on glucose, but significantly more slowly and to substantially lower densities than the parental mgi1-1 strain. In addition, oxygen consumption in the DeltaKlpgs1 strain is <1% of the parental strain. Western blot analysis of mitochondrial membrane proteins shows that the amounts of some proteins are substantially decreased or even not detectable in this mutant. However, overexpression of the KlPGS1 gene under the inducible GAL1 promoter does not restore the ability of DeltaKlpgs1 cells to grow on galactose, indicating the presence of some other mutations and/or deletions in genes involved in oxidative phosphorylation. We also demonstrate that DeltaKlpgs1 cells do not spontaneously lose mtDNA, but are able to survive its loss after ethidium bromide mutagenesis. Deletion of the cardiolipin synthase gene (KlCLS1) in mgi1-1 has only a minimal effect on mitochondrial physiology, and additional experiments show that this deletion is also viable in wild-type K. lactis.

[Clinical condition of patients with neural tube defects]. / Klinický stav pacientov s defektami neurálnej rúry.

INTRODUCTION: Neural tube defects are the most common congenital anomalies of central nervous system. Their onset is at the embryonic age of 21 to 28 days. Periconceptional administration of folic acid may reduce the occurrence of neural tube defects up to 70%. Clinical features depend on localization of the defect and malformation of central nervous system, as well as on intensive multidisciplinary care in early stages of development. Open defects (meningomyelocele) present with more severe neurological deficiency early after birth. Closed defect manifestation occurs usually later in life with tethered cord syndrome. PURPOSE: This study evaluates clinical status of the patients with neural tube defects, who are followed in the Children's Faculty Hospital in Bratislava. METHODS: Cross-sectional and also retrospective study was conducted by questionnaire that was given to mothers of children with neural tube defect. Data about perinatal and family history, occurrence of hydrocephalus, scoliosis, joint deformities, dysfunction of urinary system and bowel, as well as social care, were collected. Clinical features were statistically evaluated depending on beginning of the defect or locomotion status. RESULTS: 94 patients with mean age of 12.7 years +/- 6.59 SD were included in the study. Patients with open defects had more severe neurological deficiency with hydrocephalus, more common epilepsy, skeleton deformities, wheelchair-dependency, and dysfunction of urinary tract and bowel. Scoliosis and ability of locomotion significantly correlated with higher lever of defect, while hydrocephalus, continence, urinary infections, clean intermittent catheterization, constipation, scoliosis and joint deformities significantly correlated with the ability of locomotion (p < 0.05). CONCLUSION: For patients with neural tube defects, the level of neurological deficiency is the most important prognostic factor for many other clinical characteristics.

Lactate utilization in mitochondria prevents Bax cytotoxicity in yeast Kluyveromyces lactis.

In a search for the physiological conditions able to suppress the disruption of electron transport through the inner mitochondrial membrane induced by Bax, we found that respiratory substrate - lactate completely abolished Bax toxicity in yeast Kluyveromyces lactis. The effect of lactate was dependent on the presence of cytochrome c, as no effect was observed in the cytochrome c null strain. The investigation of lactate effect on markers of Bax toxicity showed that: (i) oxidation of lactate did not affect the decrease in oxygen consumption, but (ii) lactate was able to diminish the generation of reactive oxygen species and simultaneously to suppress Bax-induced cell death. We show that suppression of Bax lethality in K. lactis can be, in addition to anti-apoptotic proteins, achieved also by the utilization of lactate in the mitochondria.

Anti-apoptotic proteins-targets for chemosensitization of tumor cells and cancer treatment.

Apoptosis or programmed cell death is an essential process not only for the normal development and function of multi-cellular organisms but it is also an important phenomenon in tumor cells killing. Numerous studies have indicated that non surgical cancer therapies eliminate tumor cells by activating apoptosis. The central regulators of apoptosis are proteins of the Bcl-2 family. In a wide variety of human tumors, the increased expression of anti-apoptotic proteins (Bcl-2 and Bcl-(XL)) was found. Moreover, it was revealed that high levels of these proteins block the action of many chemotherapeutic drugs. Due to this fact the inhibition of anti-apoptotic function of Bcl-2 proteins could be a strategy for either to restore the normal apoptotic process in tumor cells or to make them susceptible for chemo- and radio-therapeutic treatment. Three alternative therapeutic strategies for the repression of cytoprotective activity of anti-apoptotic proteins in tumor cells are reviewed in this article.

Fatty acids induced uncoupling of Saccharomyces cerevisiae mitochondria requires an intact ADP/ATP carrier.

Fatty acids stimulate the oxidation rate of mitochondria isolated from the wild-type Saccharomyces cerevisiae, but do not affect significantly the respiration of mitochondria isolated from mutants, in which the ADP/ATP carrier (AAC) was either modified (R96H) or deleted (delta aac2). Similarly as in mammalian mitochondria, the transmembrane electrical potential difference (delta psi) in the wild-type yeast mitochondria was dissipated by low concentrations of free fatty acids, and this was partially inhibited by bongkrecate. In contrast to the wild-type mitochondria, the addition of increasing concentrations of fatty acids to the op1 (R96H) mutant mitochondria abolished only a small portion of delta psi, as compared to the change induced by classical uncouplers. The different effects of fatty acids on both, the respiration and the delta psi of mitochondria isolated from the wild-type and the aac mutants, respectively, demonstrates that the intact AAC is essential for the fatty acids induced H+ permeability of mitochondrial membrane.

Yeast ADP/ATP carrier (AAC) proteins exhibit similar enzymatic properties but their deletion produces different phenotypes.

Saccharomyces cerevisiae strains expressing a single type of ADP/ATP carrier (AAC) protein were prepared from a mutant in which all AAC genes were disrupted, by transformation with plasmids containing a chosen AAC gene. As demonstrated by measurements of [14C]ADP specific binding and transport, all three translocator proteins, AAC1, AAC2 and AAC3 when present in the mitochondrial membrane, exhibited similar translocation properties. The disruption of some AAC genes, however, resulted in phenotypes indicating that the function of these proteins in whole cells can be quite different. Specifically, we found that the disruption of AAC1 gene, but not AAC2 and AAC3, resulted in a change in colony phenotype.

ADP/ATP translocator is essential only for anaerobic growth of yeast Saccharomyces cerevisiae.

All three genes (AAC1, AAC2 and AAC3) encoding the mitochondrial ADP/ATP translocator, were inactivated in a haploid yeast strain by a gene disruption technique. The triple mutant was still able to grow on fermentable carbon sources but only in the presence of oxygen. Under aerobic conditions neither translocator-protein nor carrier-mediated transport was detected in all mutants in which the AAC2 gene was disrupted. It was further shown that a functional AAC genes product is essential only for anaerobic growth of Saccharomyces cerevisiae but not for growth under derepressed conditions. Under anaerobic conditions a non-detectable amount of AAC3 gene product is sufficient to ensure the cell growth and multiplication.

The cytotoxic action of Bax on yeast cells does not require mitochondrial ADP/ATP carrier but may be related to its import to the mitochondria.

The effect of the expression of murine Bax protein on growth and vitality was examined in Saccharomyces cerevisiae and compared with the effect of Bax in mutant cells lacking functional mitochondria. The cytotoxic effect of Bax on yeast does not require functional oxidative phosphorylation, respiration, or mitochondrial proteins (ADP/ATP carriers) implicated in the formation of the permeability transition pore in mammalian mitochondria. In the wild type S. cerevisiae the expression of Bax does not result in a severe effect on mitochondrial membrane potential and respiration. On the basis of Bax induced differences in the fluorescence of green fluorescent protein fused to mitochondrial proteins, it is proposed that Bax may interfere with one essential cellular process in yeast: the mitochondrial protein import pathway that is specific for the proteins of the mitochondrial carrier family.

Identification and expression of human c-Ha-ras and c-sis sequences in NIH3T3 transformants.

High-molecular-weight DNAs from 5 bladder carcinomas were used in transfection of mouse NIH3T3 cells. The manifestation of heterologous oncogene(s) expression in NIH3T3 cells was morphological transformation very often accompanied by changes in growth characteristics of recipient cells. In DNA samples from secondary NIH3T3 transformants human c-Ha-ras and c-sis sequences were identified. In some secondary transformants these sequences were expressed. On the basis of change of the growth characteristics of some secondary transformants we could expect the integration and expression of another human gene(s) for growth factor or growth factor receptor or even activation of mouse genes. We did not manage to identify any Alu sequences in some secondary transformants carrying human c-Ha-ras sequences. On the other hand, it has not been revealed yet that BamHI DNA fragments carrying c-Ha-ras gene contained any Alu sequence. So, the identification of Alu sequences does not have to be the first step in investigation of DNA samples from NIH3T3 transformants.

Heterogeneity of neoplastic cells derived from a hamster tumor induced by avian sarcoma virus B77.

Cells derived from a hamster tumor induced by avian sarcoma virus Bratislava 77 (B77) in vivo, were cultivated in vitro. After few passages two morphologically different cell lines were isolated from the parental culture (B77/H). One cell line consisted of fibroblastic cells (B77/H/fi and the other from epithelioid cells (B77/H/ep). Cells of both lines were highly tumorigenic in neonatal syngeneic hamsters, B77/H/ep cells were able to form colonies in soft agar and contained complete integrated B77 viral genome. In contrast, the B77/H/fi cells grew poorly in soft agar and did not contained B77 virus genome.

Metastasizing fibrosarcomas in hamsters (BMH) after injection of B77 sarcoma virus transformed mouse cells.

Injection of virogenic mouse cells B77-1026 into newborn Syrian hamsters resulted in arising of progressively growing autochthonous fibrosarcomas. From hamster tumors five stable tumor cell lines (BMH/1--BMH/5) were established in vitro. All cells of the newly established tumor cell lines had hamster karyotype, they were able to grow in soft agar and did not contain rescuable B77 viral genome. BMH tumor cells injected into syngeneic newborn as well as young adult hamsters produced tumors at the site of application and metastasized frequently into viscera. From metastases in different organs further tumor cell lines and single cell clones were established in vitro. All these tumor cell lines and clones exhibited higher metastatic capacity than the parent cell lines.

Molecular and biological properties of hamster tumor cell lines transformed with B77 virus: expression of v-src does not correlate with metastatic potential.

Three hamster tumor cell lines (B77Hep, B77H1De and ML cl 3.1) were investigated with the aim to determine some biological and molecular properties of cells which are connected with invasive and metastatic ability. Except B77H1De all cell lines exhibited high metastatic capacity in syngeneic adult animals. Analysis of cell lines revealed a relationship between metastatic ability and growth properties (growth rate, saturation density and colony formation in soft agar). Southern blot analysis of genomic DNA samples from high metastatic cell line (B77Hep) and low metastatic (B77H1De) showed that the metastatic potential of these cell lines did not depend on the number of integrated proviral copies. Northern blot analysis was used to determine the level of mRNA encoded by v-src gene in B77Hep and B77H1De cell lines. We found a good correlation between the number of integrated proviral copies and the level of v-src gene expression in investigated cell lines, but not with their metastatic potential. No proviral sequences were found in genomic DNA isolated from ML cl 3.1 cell line. In cell lines used in this study we found differences in expression of endogenous proto-oncogenes c-myc and c-fos.

Novel VANGL1 Gene Mutations in 144 Slovakian, Romanian and German Patients with Neural Tube Defects.

Neural tube defects (NTDs) are a group of congenital malformations of the central nervous system occurring at an average rate of 1 per 1,000 human pregnancies worldwide. Numerous genetic and environmental factors are discussed to be relevant in their etiology. In mice, mutants in >200 genes including the planar cell polarity (PCP) pathway are known to cause NTDs, and recently, heterozygous mutations in the human VANGL1 gene have been described in a small subset of patients with NTDs. We performed a VANGL1 mutation analysis in 144 unrelated individuals with NTDs from Slovakia, Romania and Germany and identified 3 heterozygous missense mutations: c.613G>A (p.Gly205Arg) with an open spina bifida (lumbosacral meningomyelocele), c.557G>A (p.Arg186His) with a closed spina bifida (tethered cord and spinal lipoma) and c.518G>A (p.Arg173His) with an unknown NTD. The c.613G>A mutation was also found in a healthy sibling. None of the mutations were described previously. Findings support that heterozygous VANGL1 mutations represent hypomorphs or conditional mutants predisposing to NTDs and occur at a frequency of approximately 2.1% of open and closed spinal NTDs. The mutations (p.Arg173His, p.Arg186His, p.Gly205Arg) modified conserved regions of the VANGL1 protein and shared similarities with previously described mutants, providing further evidence for the presence of mutational hot spots in these patients.