Further Evidence for Shape Coexistence in

Isomers close to doubly magic _{28}^{78}Ni_{50} provide essential information on the shell evolution and shape coexistence near the Z=28 and N=50 double shell closure. We report the excitation energy measurement of the 1/2^{+} isomer in _{30}^{79}Zn_{49} through independent high-precision mass measurements with the JYFLTRAP double Penning trap and with the ISOLTRAP multi-reflection time-of-flight mass spectrometer. We unambiguously place the 1/2^{+} isomer at 942(10) keV, slightly below the 5/2^{+} state at 983(3) keV. With the use of state-of-the-art shell-model diagonalizations, complemented with discrete nonorthogonal shell-model calculations which are used here for the first time to interpret shape coexistence, we find low-lying deformed intruder states, similar to other N=49 isotones. The 1/2^{+} isomer is interpreted as the bandhead of a low-lying deformed structure akin to a predicted low-lying deformed band in ^{80}Zn, and points to shape coexistence in ^{79,80}Zn similar to the one observed in ^{78}Ni. The results make a strong case for confirming the claim of shape coexistence in this key region of the nuclear chart.

First Evidence of Axial Shape Asymmetry and Configuration Coexistence in

The excited states of N=44 ^{74}Zn were investigated via γ-ray spectroscopy following ^{74}Cu ß decay. By exploiting γ-γ angular correlation analysis, the 2_{2}^{+}, 3_{1}^{+}, 0_{2}^{+}, and 2_{3}^{+} states in ^{74}Zn were firmly established. The γ-ray branching and E2/M1 mixing ratios for transitions deexciting the 2_{2}^{+}, 3_{1}^{+}, and 2_{3}^{+} states were measured, allowing for the extraction of relative B(E2) values. In particular, the 2_{3}^{+}→0_{2}^{+} and 2_{3}^{+}→4_{1}^{+} transitions were observed for the first time. The results show excellent agreement with new microscopic large-scale shell-model calculations, and are discussed in terms of underlying shapes, as well as the role of neutron excitations across the N=40 gap. Enhanced axial shape asymmetry (triaxiality) is suggested to characterize ^{74}Zn in its ground state. Furthermore, an excited K=0 band with a significantly larger softness in its shape is identified. A shore of the N=40 "island of inversion" appears to manifest above Z=26, previously thought as its northern limit in the chart of the nuclides.

Association between HLA-DQB1 and cervical dysplasia in Vietnamese women.

Host genetic background seems to play a key role in cervical carcinogenesis as only a small subset of women infected with high-risk human papillomaviruses (HPVs) develop cervical cancer. The rate of cervical cancer in Vietnamese women is notably high. To explore the association of human leukocyte antigen (HLA)-DQB1 alleles, HPV infection, and cervical dysplasia in this population, cervical smears were obtained from 101 women attending the obstetrics and gynecology clinic of Da Nang General Hospital in Vietnam. Besides the Papanicolaou test, HPV and HLA-DQB1 genotyping were performed using cervical smear DNA. Additionally, a subset of 30 blood samples was used as the gold standard for HLA genotyping. HLA-DQB1 alleles showed no association with HPV infection status. However, a positive association with cervical dysplasia was found for HLA-DQB1*0302 (P= 0.0229, relative risk (RR) = 4.737) and HLA-DQB1*0601 (P= 0.0370, RR = 4.038), whereas HLA-DQB1*0301 (P= 0.0152, RR = 0.221) was found negatively associated. The low diversity of HLA-DQB1 alleles, wide spectrum of HPV genotypes, and high prevalence of HPV 16 and HPV 18 observed in the study population suggest a permissive/susceptible genetic background that deserves further research. Total concordance of HLA-DQB1 genotyping results between blood and cervical cells confirms the potential value of cervical smears as an effective tool for the development of cervical cancer biomarkers.

Drosophila melanogaster Cad99C, the orthologue of human Usher cadherin PCDH15, regulates the length of microvilli.

Actin-based protrusions can form prominent structures on the apical surface of epithelial cells, such as microvilli. Several cytoplasmic factors have been identified that control the dynamics of actin filaments in microvilli. However, it remains unclear whether the plasma membrane participates actively in microvillus formation. In this paper, we analyze the function of Drosophila melanogaster cadherin Cad99C in the microvilli of ovarian follicle cells. Cad99C contributes to eggshell formation and female fertility and is expressed in follicle cells, which produce the eggshells. Cad99C specifically localizes to apical microvilli. Loss of Cad99C function results in shortened and disorganized microvilli, whereas overexpression of Cad99C leads to a dramatic increase of microvillus length. Cad99C that lacks most of the cytoplasmic domain, including potential PDZ domain-binding sites, still promotes excessive microvillus outgrowth, suggesting that the amount of the extracellular domain determines microvillus length. This study reveals Cad99C as a critical regulator of microvillus length, the first example of a transmembrane protein that is involved in this process.

The pharmacokinetics of a single dose of artemisinin in subjects with liver cirrhosis. Bach Mai-Amsterdam Research Group on Artemisinin.

Artemisinin is mainly eliminated by hepatic transformation. To investigate whether the clearance of artemisinin in patients with liver cirrhosis is different from healthy volunteers, a pharmacokinetic study was performed in male Vietnamese patients with Child B cirrhosis of the liver who received 500 mg of artemisinin orally. The results were compared to those found in a previous study in healthy subjects. The mean (+/- SD) area under the concentration time curve was 2365 (+/- 1761) h ng/ml; the mean (+/- SD) clearance, 382 (+/- 303)L/h. The elimination half life was 4 (+/- 1.3) h extimated by log-linear regression and 2.4 +/- 0.9 h estimated by non-linear regression using a one-compartment first order elimination model. The mean (+/- SD) absorption time was 1.55 (+/- 0.8) h. These results were not different from the results of healthy subjects and show that liver disease has no effect on the availability and clearance of oral artemisinin, indicating that artemisinin has an intermediate hepatic extraction ratio and that there is no significant first pass effect.

The pharmacokinetics of a single dose of artemisinin in patients with uncomplicated falciparum malaria.

The pharmacokinetics of artemisinin was studied in 11 Vietnamese patients with uncomplicated falciparum malaria after a single 500 mg oral dose. Curative treatment with mefloquine (15 mg/kg) was provided 24 hr after the artemisinin dose. Artemisinin concentrations were measured by high-performance liquid chromatography with electrochemical detection. The following pharmacokinetic results were found (all mean +/- SD); calculated volume of distribution/bioavailability = 22.8 +/- 16.6 L.kg-1, mean absorption time = 1.16 +/- 0.92 hr, calculated maximum concentration = 364 +/- 250 micrograms.L-1 occurring at 2.88 +/- 1.71 hr after drug intake, and an elimination half-life of 2.72 +/- 1.76 hr. Bioavailability was low. These results do not differ from results in healthy subjects. Parasites disappeared rapidly, with a mean parasite clearance time of 36 hr. No relationship was found between pharmacokinetics and the parasite elimination rate. Tolerance to the single dose of artemisinin was good. No adverse effects were detected. In conclusion, pharmacokinetics of a single dose of artemisinin for uncomplicated falciparum malaria is not different from findings in healthy subjects. A single dose of 500 mg of artemisinin is effective in reducing parasitemia in nonsevere lalciparum malaria and is well-tolerated.

Hybridization of DNA targets to glass-tethered oligonucleotide probes.

Hybridization of nucleic acids to surface-tethered oligonucleotide probes has numerous potential applications in genome mapping and DNA sequence analysis. In this article, we describe a simple standard protocol for routine preparation of terminal amine-derivatized 9-mer oligonucleotide arrays on ordinary microscope slides and hybridization conditions with DNA target strands of up to several hundred bases in length with good discrimination against mismatches. Additional linker arms separating the glass surface from the probe sequence are not necessary. The technique described here offers a powerful tool for the detection of specific genetic mutations.

Advances in genosensor research.

Microfabricated devices containing arrays of nucleic acid hybridization sites, known as genosensors, are being developed for a variety of uses in genomic analysis. A great deal of the overall genosensor development effort involves optimization of experimental conditions in the actual use of genosensors. Here we describe a "low-tech" form of genosensor technology, involving arrays of oligonucleotides on glass microscope slides, which can be used to define optimal operating conditions and to develop applications of hybridization arrays in genome mapping and sequencing. In addition, we describe a porous silicon genosensor, which can be operated in a flowthrough mode, and discuss its advantages over current flat-surface designs. Porous silicon genosensors containing arrays of DNA fragments offer several unique capabilities in genome analysis.

Loss of heterozygosity and overexpression of p53 gene in human primary prostatic adenocarcinoma.

We have examined the loss of heterozygosity (LOH) of codon 72 and evaluated the overexpression of the tumor suppressor gene p53 in 43 primary human prostatic adenocarcinomas (PC). DNA from tumors and normal tissues were extracted from radical prostatectomy specimens. LOH was determined by restriction fragment length polymorphism analysis (RFLP) of the codon-specific endonuclease-digested polymerase chain reaction (PCR) products. Results showed 17 heterozygous cases (39%) among this patient group. Seven of the heterozygous cases displayed LOH. Six of the seven LOH cases were high-grade PCs with Gleason's combined score of > or = 7 and showed capsular invasion. One of the LOH cases, however, displayed an intermediate morphological score of 6 but also with evidence of capsular invasion. The 43 primary PCs were also examined for overexpression of p53 by a monoclonal antibody-mediated immunofluorescence reaction. Overexpression of nuclear p53 as detected by antibody was demonstrable only in tumors with combined morphological Grade > or = 7. No significant overexpression of p53 was noted in lower-grade tumors. In addition, 10 cases of benign prostatic hyperplasia (BPH) were evaluated for p53 expression. All 10 cases showed no detectable p53 overexpression.

Deletion of the retinoblastoma gene in multiple myeloma.

Deletion of the retinoblastoma gene (Rb-1) was found in more than 50% (12/23) of patients with multiple myeloma (MM) by fluorescence in situ hybridization (FISH). Myeloma cells were highly purified from bone marrow aspirates by flow cytometry and analyzed using probes specific for the Rb-1 gene and the centromeric region of chromosomes 13 and 21. Routine cytogenetics revealed abnormal chromosome 13 in only 17% (4/23) of these patients. No correlation between Rb-1 deletion and tumor stage, immunoglobulin isotype, anemia, serum beta-2 microglobulin levels, patient age or the extent of prior therapy was found. However, the high incidence of Rb-1 deletion detected by FISH suggests a role of this tumor suppressor gene in the biology of MM. Although allelic loss of the Rb-1 gene is unlikely to be the only genetic change necessary for the development of MM, it may be a relatively early event in MM unrelated to chemotherapeutic intervention. Since the Rb-1 gene suppresses IL-6 production and secretion, Rb-1 deletion may result in deregulation of IL-6 expression and hence expansion of IL-6 dependent myeloma clones.

Genetic mechanisms of tumor-specific loss of 11p DNA sequences in Wilms tumor.

Wilms tumor, a common childhood renal tumor, occurs in both a heritable and a nonheritable form. The heritable form may occasionally be attributed to a chromosome deletion at 11p13, and tumors from patients with normal constitutional chromosomes often show deletion or rearrangement of 11p13. It has been suggested that a germinal or somatic mutation may occur on one chromosome 11 and predispose to Wilms tumor and that a subsequent somatic genetic event on the normal homologue at 11p13 may permit tumor development. To study the frequency and mechanism of such tumor-specific genetic events, we have examined the karyotype and chromosome 11 genotype of normal and tumor tissues from 13 childhood renal tumor patients with different histologic tumor types and associated clinical conditions. Tumors of eight of the 12 Wilms tumor patients, including all viable tumors examined directly, show molecular evidence of loss of 11p DNA sequences by somatic recombination (four cases), chromosome loss (two cases), and recombination (two cases) or chromosome loss and duplication. One malignant rhabdoid tumor in a patient heterozygous for multiple 11p markers did not show any tumor-specific 11p alteration. These findings confirm the critical role of 11p sequences in Wilms tumor development and reveal that mitotic recombination may be the most frequent mechanism by which tumors develop.

Nonrandom loss of maternal chromosome 11 alleles in Wilms tumors.

A series of gene probes for chromosome 11 has been used to study the genetic events associated with the development of Wilms tumor. Examination of DNA samples from five patients with Wilms tumor in whom the tumors showed loss of chromosome 11 alleles and their parents indicate that alleles lost in the tumors are of maternal origin. These data suggest that the parental derivation of chromosome 11 alleles lost in these Wilms tumors is not random.

Different forms of human liver glutathione S-transferases arise from dimeric combinations of at least four immunologically and functionally distinct subunits.

Four immunologically distinct subunits were characterized in glutathione (GSH) S-transferases of human liver. Five cationic enzymes (pI 8.9, 8.5, 8.3, 8.2 and 8.0) have an apparently similar subunit composition, and are dimers of 26 500-Mr (A) and 24 500-Mr (B) subunits. A neutral enzyme, pI 6.8, is a dimer of B-type subunits. One of the anionic enzymes, pI 5.5, is also a dimer of 26 500-Mr subunits. However, the 26 500-Mr subunits of this anionic enzyme form are immunologically distinct from the A subunits of the cationic enzymes, and have been designated as A'. Immunoabsorption studies with the neutral enzyme, BB, and the antibodies raised against the cationic enzymes (AB) indicate that A and B subunits are immunologically distinct. Hybridization in vitro of the A and B subunits of the cationic enzymes (AB) results in the expected binary combinations of AA, AB and BB. Studies with the hybridized enzyme forms indicate that only the A subunits express GSH peroxidase activity. A' subunits have maximum affinity for p-nitrobenzyl chloride and p-nitrophenyl acetate, and the B subunits have highest activity towards 1-chloro-2,4-dinitrobenzene. The other anionic form, pI 4.5, present in liver is a heterodimer of 22 500-Mr (C) and B subunits. The C subunits of this enzyme are probably the same as the 22 500-Mr subunits present in human lung and placental GSH transferases. The distinct immunological nature of B and C subunits was also demonstrated by immunoaffinity and subunit-hybridization studies. The results of two-dimensional polyacrylamide-gel-electrophoretic analyses indicate that in human liver GSH transferases, three charge isomers of Mr 26 500 (A type), two charge isomers of Mr 24 500 (B type) and two charge isomers of Mr 22 500 (C type) subunits are present.

Rat lung glutathione S-transferases: subunit structure and the interrelationship with the liver enzymes.

Six forms of glutathione S-transferases designated as GSH S-transferase I (pI 8.8), II (pI 7.2), III (pI 6.8), IV (pI 6.0), V (pI 5.3) and VI (pI 4.8) have been purified from rat lung. GSH S-transferase I (pI 8.8) is a homodimer of Mr 25,000 subunits; GSH S-transferases II (pI 7.2) and VI (pI 4.8) are homodimers of Mr 22,000 subunits; and GSH S-transferases III (pI 6.8), IV (pI 6.0) and V (pI 5.3) are dimers composed of Mr 23,500 and 22,000 subunits. Immunological properties, peptide fragmentation analysis, and substrate specificity data indicate that Mr 22,000, 23,500 and 25,000, are distinct from each other and correspond to Ya, Yb, and Yc subunits, respectively, of rat liver.

Purification and characterization of glutathione S-transferases in human retina.

Human retina has two forms of glutathione (GSH) S-transferases. These forms having pI 4.5 and greater than 10 have been purified and their kinetic, structural and immunological characteristics are described. Both the enzymes of human retina do not express glutathione peroxidase II activity. The anionic enzyme (pI 4.5) of retina cross reacts with the antibodies raised against the anionic GSH S-transferases of human lung and placenta but does not cross react with the antibodies raised against the cationic enzymes of human liver. On the other hand, the cationic enzyme (pI greater than 10) of human retina cross reacts with the antibodies raised against the cationic GSH S-transferases of human liver but not with antibodies raised against the anionic enzymes of lung and placenta. Differences in the kinetic characteristics of the two forms of human retinal GSH S-transferases are also indicated. Results of these studies suggest that the anionic enzyme of retina may be similar to the anionic enzymes of lung and placenta. However, the cationic form appears to be different from all other GSH S-transferases of human tissues characterized so far. Human retina has selenium dependent glutathione peroxidase I and in this respect is different from bovine retina which has no glutathione peroxidase I as demonstrated in earlier studies.

Human glutathione S-transferases. Characterization of the anionic forms from lung and placenta.

Anionic glutathione S-transferases were purified from human lung and placenta. Chemical and immunochemical characterization, including polyacrylamide-gel electrophoresis, gave strong evidence that the anionic lung and placental enzymes are chemically similar, if not identical, proteins. The electrophoretic mobilities of both proteins were identical in conventional alkaline gels as well as in gels containing sodium dodecyl sulphate. Gel filtration of the intact active enzyme established an Mr value of 45000; however, with sodium dodecyl sulphate/polyacrylamide-gel electrophoresis under dissociating conditions a subunit Mr of 22500 was obtained. Amino acid sequence analysis of the N-terminal region of the placental enzyme revealed a single polypeptide sequence identical with that of lung. Results obtained from immunoelectrophoresis, immunotitration, double immunodiffusion and rocket immunoelectrophoresis also indicated the anionic lung and placental enzymes to be closely similar. The chemical similarity of these two proteins was further supported by protein compositional analysis and fragment analysis after chemical hydrolysis. Immunochemical comparison of the anionic lung and placental enzymes with human liver glutathione S-transferases revealed cross-reactivity with the anionic omega enzyme, but no cross-reactivity was detectable with the cationic enzymes. Comparison of the N-terminal region of the human anionic enzyme with reported sequences of rat liver glutathione S-transferases gave strong evidence of chemical similarity, indicating that these enzymes are evolutionarily related. However, computer analysis of the 30-residue N-terminal sequence did not show any significant chemical similarity to any other reported protein sequence, pointing to the fact that the glutathione S-transferases represent a unique class of proteins.

Comparative effect of the induction of the subunits of rat liver glutathione S-transferases by butylated hydroxytoluene.

When butylated hydroxytoluene (BHT) was administered to rats, the smallest subunit Ya (Mr 22,000) of rat liver GSH S-transferases was found to undergo maximum induction. It is suggested that the differential induction of GSH S-transferase activities by BHT towards different substrates may be due to the differences in the induction of the constituent subunits of GSH S-transferases.