A novel tridentate bis(phosphinic acid)phosphine oxide based europium(III)-selective Nafion membrane luminescent sensor

A new europium(III) membrane luminescent sensor based on a new tridentate bis(phosphinic acid)phosphine oxide (3) system has been developed. The synthesis of this new ligand is described and its full characterization by NMR, IR and elemental analyses is provided. The luminescent complex formed between europium(III) chloride and ligand 3 was evaluated in solution, observing that its spectroscopic and chemical characteristics are excellent for measuring in polymer inclusion membranes. Included in a Nafion membrane, all the parameters (ligand and ionic additives) that can affect the sensitivity and selectivity of the sensing membrane as well as the instrumental conditions were carefully optimized. The best luminescence signal (λexc = 229.06 nm and λem = 616.02 nm) was exhibited by the sensing film having a Nafion : ligand composition of 262.3 : 0.6 mg mL(-1). The membrane sensor showed a short response time (t95 = 5.0 ± 0.2 min) and an optimum working pH of 5.0 (25 mM acetate buffer solution). The membrane sensor manifested a good selectivity toward europium(III) ions with respect to other trivalent metals (iron, chromium and aluminium) and lanthanide(III) ions (lanthanum, samarium, terbium and ytterbium), although a small positive interference of terbium(III) ions was observed. It provided a linear range from 1.9 × 10(-8) to 5.0 × 10(-6) M with a very low detection limit (5.8 × 10(-9) M) and sensitivity (8.57 × 10(-7) a.u. per M). The applicability of this sensing film has been demonstrated by analyzing different kinds of spiked water samples obtaining recovery percentages of 95-97%.

Use of DOP-PCR for amplification and labeling of BAC DNA for FISH

Fluorescence in situ hybridization (FISH) is a powerful molecular cytogenetic method that permits rapid detection of specific chromosomal rearrangements. It is based on the hybridization of fluorescent labeled probes to metaphase chromosomes or interphase nuclei. The DNA probes commonly are generated from cloned sources such as bacterial artificial chromosomes (BACs). The major disadvantage of this approach is that it requires laborious and time-consuming work. We used a degenerate oligonucleotide primed polymerase chain reaction (DOP-PCR) for both amplification and labeling of very small amounts of purified BAC DNA for FISH. The DOP-PCR reaction was processed in two steps: pre-amplification followed by simultaneous amplification and labeling of BAC DNA. The DOP-PCR probes obtained provided good hybridization signals and low background. Thus, DOP-PCR can be used to produce unlimited quantities of FISH probes with decreased cost and labor.

Coparalogy: physical and functional clusterings in the human genome

Two rounds of large-scale duplications are thought to have occurred in early vertebrate ancestry; this is now known as the "2R hypothesis." They have led to the constitution of subfamilies of paralogous genes. Chromosomal regions that contain present-day paralogs (paralogous regions or paralogons) have been identified in mammals. We show that sets of paralogons (PGs) can be assembled in a tentative "human genome paralogy map" that includes all autosomes and X. A total of 14 PGs, containing more than 1600 genes, were assembled in this paralogy map. Genes that belong to the same PG are coparalogs. We show that identification of coparalogy can be used (i) to broaden data on gene mapping, (ii) to identify physical gene clusters that derive from early cis-duplications, and (iii) to speculate on coevolution and coregulation of genes sharing a common structure or function (functional clusters). Thus, coparalogy analyses should parallel phylogenetic analyses and can help draw hypotheses on gene and genome evolution.

Homeobox gene clusters and the human paralogy map

Homeobox genes encode important developmental control proteins. In vertebrates, those encoding the proteins of the HOX class and their most closely related families, including paraHOX and metaHOX classes, are clustered in paralogous regions (or paralogons). We show that the majority of the other homeobox genes (we called contraHOX) can also be clustered and belong to paralogons in humans. This suggests that they duplicated during vertebrate evolution along the same processes as the HOX genes. We tentatively assembled several paralogons in superparalogons. One of the superparalogons contains the contraHOX genes. These observations were extended to hundreds of genes, and allowed to describe a primary human genome paralogy map.

MetaHox gene clusters

Homeobox genes encode important developmental control proteins. The Drosophila fruit fly HOM complex genes are clustered in region 84-89 of chromosome 3. Probably due to large-scale genome duplication events, their human HOX orthologs belong to four paralogous regions. A series of 13 other homeobox genes are also clustered in region 88-94, on the same chromosome of Drosophila. We suggest that they also duplicated during vertebrate evolution and belong to paralogous regions in humans. These regions are on chromosome arms 4p, 5q, 10q, and 2p or 8p. We coined the term "paralogon" to designate paralogous regions in general. We propose to call these genes "meta Hox" genes. Like Hox genes, metaHox genes are present in one cluster in Drosophila and four clusters (metaHox A-D) in humans on the 4p/5q/10q paralogon.

[FGFR1 and MOZ, two key genes involved in malignant hemopathies linked to rearrangements within the chromosomal region 8p11-12]

Two distinct clinical syndromes have been associated with the p11.12 region of the short arm of chromosome 8: stem-cell myeloproliferative disorder (B-or T-cell lymphoblastic leukemia/lymphoma with myeloid hyperplasia and peripheral blood eosinophilia) and acute myeloid leukemia (myelomonocytic or monocytic with erythrophagocytosis). The FGFR1 and MOZ genes are rearranged in these diseases and encode one of the four fibroblast growth factor receptors and a member of a novel histone acetyltransferase family, respectively. The predicted fusion proteins that are putatively oncogenic - FOP-FGFR1, CEP110-FGFR1, and FIM-FGFR1 - and - MOZ-CBP, MOZ-p300, and MOZ-TIF2 - lead to tumorigenesis through distinct pathways. The constitutive kinase activity triggered by dimerization mediated by the protein-protein interaction motifs of the FGFR1 protein partner regardless of external stimuli and the delocalization of the fusion proteins compared to their normal counterparts may lead to tumorigenesis presumably by inducing inappropriate recruitment in the cytoplasm of signaling substrates. Currently, little is known about the precise role of MOZ in the regulation of gene transcription. However, all the aberrant proteins described to date retain the MOZ histone acetyltransferase domain fused to that of the transcription coactivators CBP, p300, and TIF2. The fusion of two acetyltransferases whose activity may be mistargetted or misregulated could be a critical event in leukemogenesis. The increasing number of translocations affecting FGFR1 and MOZ strongly suggest their involvement in oncogenic processes and point to these proteins as potential therapeutical targets.

[Hysterectomy of "necessity"--current evaluation]

Hysterectomy after caesarian section is a radical surgery intervention. The obstetricians take the decision as a last surgical attitude in major obstetrical emergency. We tried in this study to analyze the causes of post-caesarian section, because this surgical intervention is a mutilant one. In many cases this surgical intervention had been effectuated for abundant hemorrhage, uterine hypotonia, utero-placentar apoplexy. In some cases the intervention was indicated from the beginning of intervention. The clinic evolution after hysterectomy was a good one without major complications.

Translocation and coamplification of loci from chromosome arms 8p and 11q in the MDA-MB-175 mammary carcinoma cell line

Rearrangement and coamplification of the 8p12 and 11q13 chromosomal regions occurs in a significant proportion of breast cancers. It usually involves a complex hybrid structure in which the FGFR1 and CCND1 genes are amplified. We report here a different type of 8p12-11q13 rearrangement in the MDA-MB-175 mammary carcinoma cell line. This amplification contains the NRG1/HGL (from 8p12-21) and DOC4 (from 11q13) genes, encoding respectively a ligand for ERBB receptors and a stress-induced protein which is a mammalian ortholog of Drosophila Tenm/Odz. It has been shown previously (Wang et al, Oncogene 18: 5718-5721, 1999) that these two genes are rearranged and fused by a translocation event. This type of event was not found in 30 tumors tested that showed coamplification of the 8p12 and 11q13 regions.

FGFR1 is fused to the centrosome-associated protein CEP110 in the 8p12 stem cell myeloproliferative disorder with t(8;9)(p12;q33)

The hallmark of the 8p12 stem cell myeloproliferative disorder (MPD) is the disruption of the FGFR1 gene, which encodes a tyrosine kinase receptor for members of the fibroblast growth factor family. FGFR1 can be fused to at least 3 partner genes at chromosomal regions 6q27, 9q33, or 13q12. We report here the cloning of the t(8;9)(p12;q33) and the detection of a novel fusion betweenFGFR1 and the CEP110 gene, which codes for a novel centrosome-associated protein with a unique cell-cycle distribution. CEP110 is widely expressed at various levels in different tissues and is predicted to encode a 994-amino acid coiled-coil protein with 4 consensus leucine zippers [L-X(6)-L-X(6)-L-X(6)-L]. Both reciprocal fusion transcripts are expressed in the patient's cells. The CEP110-FGFR1 fusion protein encodes an aberrant tyrosine kinase of circa 150-kd, which retains most of CEP110 with the leucine zipper motifs and the catalytic domain of FGFR1. Transient expression studies show that the CEP110-FGFR1 protein has a constitutive kinase activity and is located within the cell cytoplasm. (Blood. 2000;95:1788-1796)

let-756, a C. elegans fgf essential for worm development

In vertebrates, Fibroblast Growth Factors (FGFs) and their receptors are involved in various developmental and pathological processes, including neoplasia. The number of FGFs and their large range of activities have made the understanding of their precise functions difficult. Investigating their biology in other species might be enlightening. A sequence encoding a putative protein presenting 30-40% identity with the conserved core of vertebrate FGFs has been identified by the C. elegans sequencing consortium. We show here that this gene is transcribed and encodes a putative protein of 425 amino acids (aa). The gene is expressed at all stages of development beyond late embryogenesis, peaking at the larval stages. Loss-of-function mutants of the let-756 gene are rescued by the wild type fgf gene in germline transformation experiments. Two partial loss-of-function alleles, s2613 and s2809, have a mutation that replaces aa 317 by a stop. The truncated protein retains the FGF core but lacks a C-termins portion. These worms are small and develop slowly into clear and scrawny, yet viable and fertile adults. A third allele, s2887, is inactivated by an inversion that disrupts the first exon. It causes a developmental arrest early in the larval stages. Thus, in contrast to the other nematode fgf gene egl-17, let-756/fgf is essential for worm development.

The family of Caenorhabditis elegans tyrosine kinase receptors: similarities and differences with mammalian receptors

Transmembrane receptors with tyrosine kinase activity (RTK) constitute a superfamily of proteins present in all metazoans that is associated with the control and regulation of cellular processes. They have been the focus of numerous studies and are a good subject for comparative analyses of multigene families in different species aimed at understanding metazoan evolution. The sequence of the genome of the nematode worm Caenorhabditis elegans is available. This offers a good opportunity to study the superfamily of nematode RTKs in its entirety and to compare it with its mammalian counterpart. We show that the C. elegans RTKs constitute various groups with different phylogenetic relationships with mammalian RTKs. A group of four RTKs show structural similarity with the three mammalian receptors for the vascular endothelial growth factors. Another group comprises RTKs with a short extracellular region, a feature not known in mammals; the genes encoding these RTKs are clustered on chromosome II with other gene families, including genes encoding chitinase-like proteins. Most of the C. elegans RTKs have no direct orthologous relationship with any mammalian RTK, providing an illustration of the importance of the separate evolution of the different phyla.

The t(6;8)(q27;p11) translocation in a stem cell myeloproliferative disorder fuses a novel gene, FOP, to fibroblast growth factor receptor 1

In patients with an atypical stem-cell myeloproliferative disorder with lymphoma (B or T cell), myeloid hyperplasia, and eosinophilia, the chromosome 8p11-12 region is the site of a recurrent breakpoint that can be associated with three different partners, 6q27, 9q32-34, and 13q12. Rearrangements are supposed to affect a pluripotent stem cell capable of myeloid and lymphoid differentiation and to involve the same 8p11-12 gene. The t(8;13) translocation has recently been shown to result in a fusion between the FGFR1 gene that encodes a tyrosine kinase receptor for fibroblast growth factors and a novel gene, FIM (also called RAMP or ZNF198), belonging to a novel family of zinc finger genes. In the present study, we have cloned the t(6;8)(q27;p11) translocation in two patients and found a fusion between FGFR1 and a novel gene, FOP (FGFR1 Oncogene Partner), located on chromosome band 6q27. This gene is alternatively spliced and ubiquitously expressed. It encodes a protein containing two regions of putative leucine-rich repeats putatively folding in alpha-helices and separated by a hydrophobic spacer. The two reciprocal fusion transcripts were evidenced by reverse transcription-polymerase chain reaction in the tumoral cells of the patients. The predicted chimeric FOP-FGFR1 protein contains the FOP N-terminus leucine-rich region fused to the catalytic domain of FGFR1. It may promote hematopoietic stem cell proliferation and leukemogenesis through a constitutive phosphorylation and activation of the downstream pathway of FGFR1.

Chromosome region 8p11-p21: refined mapping and molecular alterations in breast cancer

Several genes, most of them unknown, of the short arm of chromosome 8 are involved in malignant diseases. Numerous studies have implicated a portion of the 8p11-p21 region as the location of one or more tumor suppressor genes involved in a variety of human cancers, including breast cancer. We and others have reported linkage analyses suggesting the presence of a putative breast cancer susceptibility gene. Furthermore, several oncogenes of the 8p11-p12 region are involved in reciprocal translocations in myeloproliferative and myelodysplastic disorders and in amplification in breast cancer. To facilitate the analysis of the 8p11-p21 region and the cloning of candidate oncogenes and tumor suppressor genes, a high-resolution physical and transcriptional map was established with 39 yeast artificial chromosomes and 94 markers, including so-called sequence-tagged sites and expressed sequence-tagged sites derived from either known genes or expressed sequence tags corresponding to unidentified transcripts. In addition, four novel transcripts were identified and localized precisely within the map. This transcription map provides a detailed description of gene order for the 8p11-p21 region and will be helpful in the identification of candidate genes for diseases. From this basis, we refined the mapping of two types of molecular alterations that occur at 8p11-p21 in sporadic breast cancers, i.e., amplification and deletion.

Fibroblast growth factor receptor 1 is fused to FIM in stem-cell myeloproliferative disorder with t(8;13)

Chromosome 8p11-12 is the site of a recurrent breakpoint in a myeloproliferative disorder that involves lymphoid (T- or B-cell), myeloid hyperplasia and eosinophilia, and evolves toward acute leukemia. This multilineage involvement suggests the malignant transformation of a primitive hematopoietic stem cell. In this disorder, the 8p11-12 region is associated with three different partners 6q27, 9q33, and 13q12. We describe here the molecular characterization of the t(8;13) translocation that involves the FGFR1 gene from 8p12, encoding a tyrosine kinase receptor for members of the fibroblast growth factor family, and a gene from 13q12, tentatively named FIM (Fused In Myeloproliferative disorders). FIM is related to DXS6673E, a candidate gene for X-linked mental retardation in Xq13.1; this defines a gene family involved in different human pathologies. The two reciprocal fusion transcripts, FIM/FGFR1 and FGFR1/FIM are expressed in the malignant cells. The FIM/FGFR1 fusion protein contains the FIM putative zinc finger motifs and the catalytic domain of FGFR1. We show that it has a constitutive tyrosine kinase activity.

t(6;8), t(8;9) and t(8;13) translocations associated with stem cell myeloproliferative disorders have close or identical breakpoints in chromosome region 8p11-12

A stem-cell myeloproliferative disorder involving T- and B-cell, and myeloid lineages, is associated with three different translocations with a breakpoint in region p11-12 of chromosome 8: t(6;8)(q27;p11), t(8;9)(p11;q33), and t(8;13)(p12;q12), respectively. Using fluorescence in situ hybridization (FISH), we have analysed blood cells from a series of five patients carrying these different translocations. We have identified cosmids from chromosome region 8p11-12 that span the breakpoint in all the cases. They are specific for the FCFR1 gene that encodes a receptor for members of the FGF family. The breakpoint was further detected by Southern and pulsed-field gel electrophoresis analyses with probes from the FGFR1 locus.

Novel sequence tagged sites from the human 8p12-p21 chromosomal region involved in breast cancer

Seventeen sequence-tagged sites (STSs) from the human 8p12-p21 chromosomal region were identified in a subset of nonchimeric yeast artificial chromosomes (YACs). YAC ends were cloned, sequenced and a PCR primer pair was designed for each of the STSs thus generated. STSs were mapped by means of PCR on somatic cell hybrids specific for chromosome 8. These STSs will contribute to the construction of physical, high-resolution genetic and transcriptional maps necessary to clone potential tumor suppressor genes of the 8p12-p21 region involved in breast cancer.

Hypobaric hypoxia: dual sympathetic control in the light of RR and QT spectra

ECGs of 21 candidate-pilots and 19 pilots were recorded during: 1) exposure to 5500 m hypobaric hypoxia (HH) while sitting, in the sequence: 1a) initial 7 min of adaptation (A); 1b) later 7 min of recovery (R) after short but intense tread-mill effort; and 2) final 7 min baseline (B), while sitting and requested to relax, at "0 m altitude" in the hypobaric room. RR and QT short-term variability were studied using spectral powers within Traube-Hering-Mayer (THM: 0.05-0.15 Hz) and respiratory (RESP: 0.2-0.4 Hz) bands. Mean RR proved highest capability to aggregate individual response-profiles: 15 pilots and 9 candidates entered the main (normal) cluster, featured by a comparison "triangle" set as expected: A > R < B > A. QT-THM power closely followed: 10 subjects (ss) in very normal cluster, defined as: A < R > B < A, while secondary clusters in candidates and pilots were interpreted by not-successful relaxation and exaggerated start-effects, respectively. Subjects with QT-THM normal clusters (A < R > B < A has group averages, p < = 0.05), also showed a quasi-normal "triangle" for mean RR, (A = R < B > A). During adaptation to hypoxia, pilots' QT-THM was higher than candidates' one (p < 0.02, Wilcoxon test). Study supports the emerging capability of QT-THM spectral power to index ventricular sympathetic control. Exposure to hypobaric hypoxia proved to be in these subjects a psycho-physiologic rather than a purely physiologic test.

In vitro inhibition of DNA adduct formation by hindered hydroquinols and quinones

A series of thirty-one chemicals (substituted phenols, hydroquinols, quinones and quinoneimines) were investigated as in vitro inhibitors of DNA-benzo[a]pyrene adducts formation. In order to establish the mechanisms by which such compounds may elicit a protective effect at DNA level, the influence of these compounds upon benzo[a]pyrene (BaP) activation by 3-methyl-cholanthrene-stimulated microsomes was also studied. The data obtained suggest that the tested compounds act mainly (but not only) by BaP metabolism inhibition. Several substituted hydroquinols (e.g. 2-methyl-6-tert-butyl-hydroquinol, 2,6-di-isopropyl-hydroquinol, 2,3-dimethyl-hydroquinol) and quinones (e.g. 2-methyl-6-tert-butyl-1,4-benzoquinone, 2,6-di-isopropyl-1,4-benzoquinone, 2,3-di-methyl-1,4-benzoquinone) were found to be powerful inhibitors of both BaP metabolism and of BaP-DNA adduct formation (> 95%) at a BaP:inhibitor ratio of 1:10. This effect is significantly stronger than that exerted by the 'classical' BHA or other phenolic antioxidants in similar experimental conditions. Generally, quinones were more active than their corresponding hydroquinols, suggesting that the effectiveness of hydroquinols to prevent DNA adduct formation may be due to their oxidation to quinonic forms.

[THe role of biopsy in the early diagnosis of cancer of the cervix uteri]

Among the actions of early diagnosis of uterine cervix cancers, the sequence cytologic smear, colposcopy, cervix biopsy is well-known. The authors draw the attention that in some situations the cytologic smear and colposcopy are not sufficient and it is only biopsy that defines the nature of the lesion and may give therapeutic indications. Out of a series of 55 women to whom a cervix biopsy was performed, there were 27 cases in which biopsy was justified, showing either a severe lesion or the presence of koilocytes. The authors plead for a more frequent use of cervix biopsy as a means of early diagnosis of uterine cervix cancer or of its dysplasias.

[HB antigen in the family environment]

HBs antigen was determined in 297 members of 91 families, former blood donors in whom the state of HBs antigen carrier lasted more than six months. The results emphasized the higher proportion of HBs antigen carriers in the family environment than in the general population (7.4% as against 4.9%) and the significantly higher frequency of the antigen among the members of consanguine families.