Epilepsy,occipital calcifications,and oligosymptomatic celiac disease in childhood

The association of epilepsy, occipital calcifications, and celiac disease has been recognized as a distinct syndrome. The objective of this study was to present the clinical, electrophysiologic, and neuroradiologic features in a series of patients with this syndrome. Thirty-two patients with the constellation of epilepsy, occipital calcifications, and celiac disease were identified in our epilepsy clinic. The mean age was 11 years and the mean length of follow-up was 7.4 years. The 1990 criteria of the European Society of Pediatric Gastroenterology and Nutrition were used to diagnose celiac disease. The Kruskal-Wallis statistics test was employed with a signficance of P < .05. Thirty-one patients had partial seizures, 21 of them with symptoms related to the occipital lobe. In most patients, the epilepsy was controlled or the seizures were sporadic. Three developed severe epilepsy. Occipital calcifications were present in all cases. Computed tomography in 7 patients showed hypodense areas in the white matter around calcifications, which decreased or disappeared after a period of gluten-free diet in 3 patients. A favorable outcome of epilepsy was detected in patients with the earliest dietary therapy. This study presents the largest series of children with this syndrome outside Italy. White-matter hypodensities surrounding calcifications are rarely reported. A prompt diagnosis of celiac disease might improve the evolution of the epilepsy and may improve cognitive status.     

Teaching Mother and Child Health in schools of public health

Mothers and children constitute the majority of the population and can be considered vulnerable populations. Their health is essential for personal, community, and country development. The ultimate goal of Mother and Child Health (MCH) teaching in schools of public health is to improve the health of women and children. This can be achieved by preparing professionals in the foundations of MCH either as practitioners, policy makers, or researchers. The content of MCH teaching should answer the local needs and include international and global aspects, considering the multifactorial determinants of health. Courses can be integrated into the MPH program or constitute a track within the MPH. Teaching methods should be interactive, including classroom activity and fieldwork. Faculty should be multidisciplinary.     

ZD1839 (IRESSA), an EGFR-selective tyrosine kinase inhibitor, enhances taxane activity in bcl-2 overexpressing, multidrug-resistant MCF-7 ADR human breast cancer cells

Constitutive bcl-2 overexpression increases the tumorigenic and metastatic potential of doxorubicin-resistant, estrogen-independent, MCF-7 ADR human breast cancer cells. We evaluated the sensitivity to taxanes (paclitaxel, docetaxel and IDN 5109) of 2 bcl-2-overexpressing MCF-7 ADR clones and control neomycin-transfected MCF-7 ADR neo cells. The 2 bcl-2-overexpressing MCF-7 ADR clones were relatively resistant to all 3 taxanes, whereas the MCF-7 ADR neo cells were relatively resistant to paclitaxel and docetaxel, but sensitive to IDN 5109. We found that both MCF-7 ADR neo and bcl-2-overexpressing MCF-7 ADR clones express high levels of the epidermal growth factor receptor (EGFR) and its ligand, transforming growth factor-alpha (TGF-alpha). Therefore, we tested the growth inhibitory effect of ZD1839 (Iressa, AstraZeneca, Macclesfield, UK), an orally active, selective EGFR tyrosine kinase inhibitor (EGFR-TKI) that is in clinical development. ZD1839 inhibited the growth in soft agar of all 3 clones in a dose-dependent manner (IC(50) of approximately 0.1 microm). This effect was accompanied by a dose-dependent inhibition of EGFR tyrosine autophosphorylation and of the production of TGF-alpha, basic fibroblast growth factor (bFGF) and vascular endothelial growth factor (VEGF). To determine whether the blockade of EGFR signaling might affect the sensitivity of bcl-2-overexpressing MCF-7 ADR cells to taxanes, cells were treated with ZD1839 in combination with paclitaxel, docetaxel or IDN 5109, and dose-dependent cooperative growth inhibition as well as apoptosis potentiation were observed. Combined treatment with IDN 5109 and ZD1839 also resulted in a significant inhibition of bcl-2 expression in bcl-2-overexpressing MCF-7 ADR cells. These results demonstrate the ability of ZD1839 to overcome taxane resistance in a model of hormone-independent, multidrug-resistant, human breast cancer.     

New polymer-antibiotic systems to inhibit bacterial biofilm formation: a suitable approach to prevent central venous catheter-associated infections

Intravascular catheters are widely employed in medical practice. However, complications such as local or systemic infections are frequently related to their use. The significant increase in this type of nosocomial infection has prompted the search for new strategies to prevent them. This paper reports on an experimental model to prevent catheter-related infections based on the adsorption of a beta-lactam antibiotic (cefamandole nafate) on functionalized urethane polymers. The polyurethanes synthesized were used to coat a commercial central venous catheter. The influence of functional groups on the polymer-antibiotic interaction was analyzed and the kinetics of the antibiotic release from the catheters was dynamically studied. We were able to realize a polymer-antibiotic system able to inhibit bacterial growth up to 7 days. These promising results have encouraged us to extend this experimental model to other polymer-antibiotic systems in order to identify those allowing bacterial growth inhibition for longer times.     

Mutation analysis of the CHK2 gene in breast carcinoma and other cancers

Background

Mutations in the CHK2 gene at chromosome 22q12.1 have been reported in families with Li-Fraumeni syndrome. Chk2 is an effector kinase that is activated in response to DNA damage and is involved in cell-cycle pathways and p53 pathways.

Methods

We screened 139 breast tumors for loss of heterozygosity at chromosome 22q, using seven microsatellite markers, and screened 119 breast tumors with single-strand conformation polymorphism and DNA sequencing for mutations in the CHK2 gene.

Results

Seventy-four of 139 sporadic breast tumors (53%) show loss of heterozygosity with at least one marker. These samples and 45 tumors from individuals carrying the BRCA2 999del5 mutation were screened for mutations in the CHK2 gene. In addition to putative polymorphic regions in short mononucleotide repeats in a non-coding exon and intron 2, a germ line variant (T59K) in the first coding exon was detected. On screening 1172 cancer patients for the T59K sequence variant, it was detected in a total of four breast-cancer patients, two colon-cancer patients, one stomach-cancer patient and one ovary-cancer patient, but not in 452 healthy individuals. A tumor-specific 5' splice site mutation at site +3 in intron 8 (TTgt [a → c]atg) was also detected.

Conclusion

We conclude that somatic CHK2 mutations are rare in breast cancer, but our results suggest a tumor suppressor function for CHK2 in a small proportion of breast tumors. Furthermore, our results suggest that the T59K CHK2 sequence variant is a low-penetrance allele with respect to tumor growth.     

Chromosome mapping of multiple loci affecting the genetic predisposition to rat liver carcinogenesis

Previous studies on (BNxF344)F1 (BFF1) rat model of genetic predisposition to hepatocarcinogenesis led to the identification, in BFF1xF344 backcross progeny, of two hepatocarcinogenesis susceptibility (Hcs) and three resistance (Hcr) loci affecting the progression of neoplastic liver nodules. To evaluate the presence of other hepatocarcinogenesis-related loci in the BFF1 genome, nodule induction by resistant hepatocyte model in 116 male BFF2 rats 32 weeks after initiation with diethylnitrosamine was subjected to quantitative trait loci analysis. The rats were typed with 179 genetic markers, and linkage analysis identified three loci on chromosomes 1, 16, and 6, in significant linkage with nodule mean volume (V), volume fraction, and number, respectively, and two loci on chromosomes 4 and 8 in suggestive linkage with V. These loci were differently positioned with respect to Hcs and Hcr loci mapped previously in backcross rats. On the basis of phenotypic and allele distribution patterns of BFF2 rats, loci on chromosomes 1 and 16 were identified as Hcs3 and Hcs4, and loci on chromosomes 4, 8, and 6 as Hcr4, Hcr5, and Hcr6. Additive interactions occurred between Hcs3 and Hcs4, and Hcr4 and a locus on chromosome 3 with less than suggestive linkage with V. All of the loci were in chromosomal regions syntenic to mouse and/or human chromosomal segments showing allelic gain or loss in hepatocellular carcinomas. These data indicate that inheritance of predisposition to rat liver tumor is characterized by the interplay of several genetic factors and suggest some possible mechanisms of polygenic control of human liver cancer.     

Catechol estrogen formation in liver microsomes from female ACI and Sprague-Dawley rats: comparison of 2- and 4-hydroxylation revisited

Estradiol (E(2))-hydroxylation was studied in liver microsomes from ACI and Sprague-Dawley female rats, which differ markedly in their susceptibility to E(2)-induced formation of mammary tumors. NADPH-dependent oxidation of E(2) by liver microsomes from ACI and Sprague-Dawley rats produced several metabolites of which 2-hydroxyestradiol (2-OH-E(2)), estrone (E(1)), and 2-hydroxyestrone (2-OH-E(1)) were predominant. Incubations with either low (9 nM) or high (50 microM) concentrations of radiolabeled E(2) and with varying amounts of microsomal protein indicated the formation of only small amounts of 4-hydroxyestradiol (4-OH-E(2)). The ratio of 2-OH-E(2) to 4-OH-E(2) formed with the low concentration of E(2) was about 10:1 regardless of the amount of microsomal protein used, and about 20:1 using a high concentration of E(2). Thus, oxidation of E(2) by liver microsomes from female ACI and Sprague-Dawley rats occurs primarily via 2-hydroxylation, and 4-hydroxylation is only a minor pathway. These results are in disagreement with a recent report indicating substantial 4-hydroxylation of E(2) by liver microsomes from female ACI rats.     

3-Hydroxyglutaric acid induces oxidative stress and decreases the antioxidant defenses in cerebral cortex of young rats

Glutaryl-CoA dehydrogenase deficiency (GDD) is an inherited neurometabolic disorder biochemically characterized by tissue accumulation of glutaric, 3-hydroxyglutaric (3-OHGA) and glutaconic acids and clinically by severe neurological symptoms and cerebral atrophy whose pathophysiology is poorly known. In the present study we investigated the effect of 3-OHGA, considered the main neurotoxin in GDD, on the lipoperoxidation parameters chemiluminescence and thiobarbituric acid-reactive species (TBA-RS), and on the amount of nitric oxide metabolites in cerebral cortex of young rats. Total radical-trapping antioxidant potential (TRAP), which reflects the tissue antioxidant defenses, was also examined. We observed that 3-OHGA significantly increased chemiluminescence, TBA-RS and nitric oxide metabolites, in contrast to TRAP, which was decreased by the metabolite. The data indicate a stimulation of lipid peroxidation and free radical production, and a reduction of the tissue antioxidant defenses caused by the metabolite. In case these findings also occur in the human condition, it may be presumed that oxidative stress is involved in the brain damage observed in GDD.     

Correlation between CGRP immunoreactivity and firing activity in cat abducens motoneurons

Intercellular communication through gap junction channels is a prominent feature of the developing cerebral cortex. In the first 2 weeks after birth, a time critical in the development of the rat neocortex, extensive cell coupling has been documented that diminishes as the cortex matures. Among the family of gap junction proteins, connexins 26, 36, and 43 are differentially expressed during cortical development. We used intracellular dye injections and connexin immunohistochemistry to investigate the coupling patterns and connexin expression between the different neuronal and glial cell types of the developing cortex of the rat. We found that neurons and glia couple homotypically and heterotypically at postnatal days 7 and 14. Although the prevalence of coupling was homotypic, there was considerable heterotypic coupling that involved pyramidal and nonpyramidal neurons, the principal neuronal cell types of the cortex, or neurons and astrocytes. Coupling between different cell types appeared to be mediated by differential expression of connexins 26, 36, and 43. It may be that coupling between cells in the developing neocortex is a function of the spatial and temporal expression of these and other connexin proteins.     

The hemostatic agent ethamsylate enhances P-selectin membrane expression in human platelets and cultured endothelial cells

Ethamsylate possesses antihemorrhagic properties, but whether or not it directly activates blood platelets is unclear. Here we investigated the platelet activation potential of ethamsylate, by measuring membrane P-selectin expression with flow cytometry in human whole blood and also by immunofluorescence imaging of isolated human platelets. Moreover, we measured membrane P-selectin expression in the SV40-transformed aortic rat endothelial cell line (SVAREC) and ¹⁴C-ethamsylate membrane binding and/or uptake in platelets and endothelial cells. Whole blood flow cytometry showed a modest, but statistically significant increase by ethamsylate in the percentage of platelets expressing P-selectin (from 2% to 4–5%, p<0.05). Immunofluorescence showed a sizable (39%) and significant (p<0.01) enhancement of P-selectin expression at the lowest concentration of ethamsylate tested (1 μM), with maximal enhancement of P-selectin expression (75–90%) at 10 μM ethamsylate. Similar results were obtained in SVAREC endothelial cells. ¹⁴C-ethamsylate specifically bound to platelets and endothelial cell membranes, without significant uptake into the cell interior. In conclusion, ethamsylate enhances membrane P-selectin expression in human platelets and in cultured endothelial cells. Ethamsylate specifically binds to some protein receptor in platelet and endothelial cell membranes, receptor which can signal for membrane P-selectin expression. These results support the view that ethamsylate acts on the first step of hemostasis, by improving platelet adhesiveness and restoring capillary resistance.