bluuebunny/crossref_metadata_2025 huggingface dataset:
Fluorescence in situ hybridization identifies new chromosomal changes involving 3q27 in non‐Hodgkin's lymphomas with BCL6/LAZ3 rearrangement
Authors: Wlodarska Iwona , Mecucci Cristina , Stul Michel , Michaux Lucienne , Pittaluga Stefania , Hernandez Jesus Maria , Cassiman Jean‐Jacques , De Wolf‐Peeters Christiane , van den Berghe Herman
Published: February 2007

Twelve B‐cell non‐Hodgkin's lymphomas with BCL6/LAZ3 rearrangement selected from a series of 30 lymphomas with cyto‐genetically detectable 3qter abnormalities were characterized at the histological, clinical, and cytogenetic levels, including fluorescence in situ hybridization (FISH) analysis, which was performed in all cases but one. A classical t(3;14) and t(3;22) were found in three patients (25%). In the remaining cases, eleven different 3q27 abnormalities were demonstrated and characterized with the use of chromosome painting. Seven of twelve “variant” rearrangements identified in our series affecting 1p32, 1p34, 3p14, 6q23, 12p13, 14q11, and 16p13 have not been reported before. Moreover, involvement of both homologs of chromosome 3 in distinct translocations was detected as an unexpected result in two cases and was confirmed via FISH in a third case. The putative bichromosomal rearrangements of the 3q27 region were evidenced by Southern analysis in one of these cases. In another case, FISH with a cosmid spanning the 3q27 breakpoint region demonstrated the involvement of BCL6/LAZ3 only in one of two t(3q27).

In our series, which was selected on cytogenetic and molecular criteria, 50% (6 of 12) of cases with BCL6/LAZ3 rearrangement were diagnosed as diffuse, large B‐cell lymphomas (DLCL). Another 33% (4 of 12) of cases were diagnosed as follicular center lymphomas (FL), with t(14;18)/BCL2 rearrangement in all but one case. Furthermore, in three follicular lymphoma cases in which multiple samples were analyzed, the disease showed no evidence of histological progression during a follow‐up period of 3‐14 years. The present data show that rearrangement of BCL6 is not restricted to high‐grade malignancies as was previously suggested but can also occur in low‐grade lymphomas. In addition, the appearance of BCL6/LAZ3 rearrangement in follicular lymphomas is not related to disease progression.
κ‐ and λ‐positive cells in centroblastic‐centrocytic lymphoma (follicular lymphoma) may share a secondary chromosome aberration: Reflections on early lymphoma development
Authors: Weber‐Matthiesen Klaus , Winkemann Martin , Grote Werner , Schlegelberger Brigitte
Published: February 2007

The technique of simultaneous fluorescence immunophenotyping and interphase cytogenetics (FICTION) was applied in four cases of centroblastic‐centrocytic (working formulation: follicular) lymphoma. Our aim in this study was to establish whether secondary chromosome aberrations known from a prior cytogenetic analysis were detectable in both κ‐ and λ‐expressing tumor cells from the same lymphoma patient. One of the cases did indeed contain κ‐ and λ‐positive tumor cells with trisomy 8. On the basis of our results, we reflect on the events that take place during early development of centroblastic‐centrocytic lymphoma.
Distinct Xp11.2 breakpoints in two renal cell carcinomas exhibiting X;autosome translocations
Authors: Dijkhuizen T. , van den Berg E. , Wilbrink M. , Weterman M. , van Kessel A. Geurts , Störkel S. , Folkers R. P. , Braam A. , de Jong B.
Published: February 2007

Several human renal cell carcinomas with X;autosome translocations have been reported in recent years. The t(X;1)(p11.2;q21) appears to be a specific primary anomaly, suggesting that tumors with this translocation form a distinct subgroup of RCC. Here we report two new cases, one with a t(X;10)(p11.2;q23), the other with a t(X;1)(p11.2;p34). The common breakpoint in Xp11.2 suggests that they belong to the above‐mentioned subset of RCC. Using FISH in conjunction with X‐specific YAC clones, we demonstrate that the two new cases exhibited distinct breakpoints within Xp11.2.
Molecular and cytogenetic analysis of chromosome 7 in uterine leiomyomas
Authors: Ishwad C. S. , Ferrell R. E. , Davare J. , Meloni A. M. , Sandberg A. A. , Surti U.
Published: February 2007

Uterine leiomyomas are benign tumors that arise clonally from smooth muscle cells of the myometrium. Cytogenetic studies of uterine leiomyomas have shown that about 40% have chromosome abnormalities and that deletion of 7q is a common finding. The observations suggest the possible location of a growth‐suppressor gene within the 7q21‐q22 region. Molecular genetic analysis of cytogenetically normal tumors has frequently shown somatic loss of specific tumor suppressor genes detected by loss of heterozygosity in the critical region. To test the hypothesis that chromosome region 7q21‐q22 contains a growth‐suppressor gene involved in the development of leiomyomas, we examined 92 leiomyomas for allelic loss of 7q markers spanning the cytogenetically defined critical region. Forty tumors with cytogenetically defined 7q deletion, 45 tumors without cytogenetically visible 7q deletion, and seven tumors with no cytogenetic information were examined for allelic loss of loci D7S489, D7S440, D7S492, D7S518, D7S471, D7S466, and D7S530. Loss of heterozygosity for one or more of these loci was observed in 23 of 40 (57.5%) of the tumors with deletion of 7q and in 2 of 45 cases without a cytogenetically visible deletion. The tumors with cytogenetic deletion of 7q, but no loss of 7q21‐q22 markers, were mosaics, with only a minority of cells containing the cytogenetic deletion. The critical region of loss is defined by the markers D7S518 and D7S471, each showing loss in approximately 50% of informative cases. These markers define a 10 cM region of 7q21‐q22 that is consistent with the cytogenetically defined smallest region of overlap and exclude loss of the MET oncogene locus and WNT1, the murine mammary tumor‐virus integration site, from the critical region. Our results further define a region that is consistently lost in leiomyomas with cytogenetic deletion of chromosome arm 7q. This region may contain a tumor suppressor gene involved in the development of a subset of leiomyomas.
Regional fine mapping of the multiple‐aberration region involved in uterine leiomyoma, lipoma, and pleomorphic adenoma of the salivary gland to 12q15
Authors: Wanschura S. , Kazmierczak B. , Schoenmakers E. , Meyen E. , Bartnitzke S. , van de Ven W. , Bullerdiek J. , Schloot W.
Published: February 2007

Cytogenetic aberrations involving 12q13‐15 are frequently observed in a variety of benign solid tumors. Using a chromosome walking approach combined with fluorescence in situ hybridization analysis, we were able to show that the chromosome 12 breakpoints involved in uterine leiomyoma, pleomorphic adenoma of the salivary gland, and lipoma cluster to the same chromosomal region, which we therefore designated MAR (multiple‐aberration region). By comparing the G‐banding pattern of prometaphase chromosomes of amniotic fluid cells and lymphocytes to the position of hybridization signals obtained with a cosmid pool encompassing this breakpoint hot spot region, MAR was assigned to 12q15. We conclude that, despite the cytogenetic breakpoint assignment to the three bands 12q13‐15 in individual uterine leiomyomas, lipomas, and pleomorphic adenomas of the salivary glands in the past, most likely 12q15 is the only 12q breakpoint site in these three distinct solid tumor types.
Genetic instability of chromosome 3 in HPV‐immortalized and tumorigenic human keratinocytes
Authors: Montgomery Karen Dyer , Tedford Karen L. , McDougall James K.
Published: February 2007

The HPV‐1811 cell line is derived from primary human foreskin keratinocytes that have been transfected with human papilloma virus type 18. At late passage, these cells produce invasive squamous cell carcinomas when injected into nude mice. A striking, but unstable, aberration of chromosome 3 occurs very early after establishment of the culture; a consistent rearrangement is observed concomitant with tumorigenicity. Using molecular cytogenetic techniques, we characterized the complex development of this aberration. A whole chromosome probe to this chromosome was made by linker‐adapter PCR amplification of a single flow‐sorted chromosome. Hybridization of this probe to normal metaphase chromosomes revealed the der (3) to be composed of chromosome 3, distal 13q, and 21q22. Hybridization of a 3q subtelomeric probe and a glycoprotein V probe which maps to 3qter indicated that this locus is duplicated in the final form of the chromosome, but that much instability occurs prior to its establishment. The ETS2 oncogene, which maps to 21q22, is translocated to the der(3) when the cell line becomes tumorigenic, but not prior to this time. Early‐passage cells which have been induced to become tumorigenic by exposure to the carcinogen nitrosomethylurea also have the localization of the ETS2 at 3qter.
Genetic analysis of chromosome 13 deletions in BCR/ABL negative chronic myeloproliferative disorders
Authors: Pastore Cristina , Nomdedeu Josep , Volpe Gisella , Guerrasio Angelo , Cambrin Giovanna Rege , Parvis Guido , Pautasso Marisa , Daglio Cristiano , Mazza Umberto , Saglio Giuseppe , Gaidano Gianluca
Published: February 2007

Chromosomal deletions of band 13q14 occur recurrently in BCR/ABL negative chronic myeloproliferative disorders (CMPD), including myelosclerosis with myeloid metaplasia (MMM), polycythemia vera (PV), essential thrombocythemia (ET), juvenile chronic myeloid leukemia (JCML), and the so‐called BCR/ABL − chronic myeloid leukemia (CML). The RB1 tumor suppressor locus, mapping to 13q14, has long since been hypothesized as the important gene. In this report, we have determined the frequency of 13q14 deletions at the molecular level in a large panel of BCR/ABL − CMPD at different disease stages and performed a detailed genetic analysis of gross rearrangements/deletions and point mutations of the RBI gene in these disorders. Our data show that molecular deletions of 13q14 are detected in a relatively large fraction of BCR/ABL − CMPD (38%), that they appear to be more frequent in MMM than in other BCR/ABL − CMPD, and that they may be present at diagnosis or occur during blastic evolution of the neoplasia. The RBI gene displayed a germline configuration in all BCR/ABL − CMPD tested, suggesting that 13q14 deletions in these disorders affect a tumor suppressor locus distinct from RB1.
Localization of metastasis suppressor gene(s) for rat prostatic cancer to the long arm of human chromosome 10
Authors: Nihei Naoki , Ichikawa Tomohiko , Kawana Youko , Kuramochi Hiroaki , Kugo Hiroyuki , Oshimura Mitsuo , Killary Ann M. , Rinker‐Schaeffer Carrie W. , Barrett J. Carl , Isaacs John T. , Shimazaki Jun
Published: February 2007

To examine the role of human chromosome 10 in development of prostatic cancer, we introduced human chromosome 10 into highly metastatic rat prostatic cancer cells by microcell‐mediated chromosome transfer. Microcell hybrid cells introduced with human chromosome 10 showed suppression of the metastatic ability to the lung to some extent without any suppression of tumorigenicity, although the tumor growth rate decreased slightly. To minimize the region that contains metastasis suppressive activity, the hybrid cells in metastasis foci of lung were established in culture and reanalyzed for portions of human chromosome 10 retained in the metastasis tissues. Cytogenetic and molecular analyses demonstrated that loss of the region between 10cen and D10S215 on human chromosome arm 10q was related to expression of the metastatic phenotype. These results demonstrate that the region between 10cen and D10S215 on human chromosome arm 10q contains at least one of the metastasis suppressor genes for rat prostatic cancer.
Normal human chromosome 2 induces cellular senescence in the human cervical carcinoma cell line SiHa
Authors: Uejima Hiroshi , Mitsuya Kohzoh , Kugoh Hiroyuki , Horikawa Izumi , Oshimura Mitsuo
Published: February 2007

For identification of the chromosome carrying cellular senescence‐inducing activity, normal human chromosome 2, 3, 6, 7, 9, 11, or 12 tagged with a selectable marker gene (neo) was introduced into the human cervical carcinoma cell line SiHa via microcell‐mediated chromosome transfer. Seventy‐six percent (158/207) of the G418‐resistant clones obtained by the transfer of chromosome 2 showed a remarkable change in morphology (cells were flat), and 93% (147/158) of them ceased to divide (senesced) prior to 6–9 population doublings, whereas most of the clones generated by the transfer of other chromosomes exhibited a morphology similar to that of the parental cells and continued to grow. Chromosome analyses suggested that cells which escaped from senescence contained only a small fragment derived from the transferred chromosome 2, whereas the transferred chromosomes were apparently intact in most of the continuously growing microcell hybrids with introduction of other chromosomes. These results indicate that the normal human chromosome 2 carries a gene or genes that induce cellular senescence in SiHa cells.
Microsatellite instability in endometrial carcinomas: Frequent replication errors in tumors of early onset and/or of poorly differentiated type
Authors: Kobayashi Kanji , Sagae Satoru , Kudo Ryuichi , Saito Hiroko , Koi Sumiko , Nakamura Yusuke
Published: February 2007

Endometrial and ovarian carcinomas are common among women belonging to hereditary nonpolyposis colorectal carcinoma (HNPCC) families; tumors developing in them are characterized by genetic instability due to an inherited dysfunction of the DNA‐mismatch‐repair system. To clarify the role of similar genetic factors in sporadic forms of gynecological tumors, we examined 77 endometrial and 68 ovarian carcinomas for replication error (RER) at five microsatellite loci. RER‐positive phenotypes at two or more microsatellite loci were observed in 18 of the endometrial carcinomas, but in only two of the ovarian carcinomas. Among the patients with endometrial carcinomas, the frequency of RER tended to be higher in those under age 50 than in those over age 60. Furthermore, RER was significantly more frequent in poorly differentiated than in well‐differentiated tumors (P = 0.008, Fisher's exact test). These data suggest that genetic factors characterized by RER are likely to play an important role in some endometrial carcinomas, particularly those of early onset and/or of the poorly differentiated type.
Allelic loss in squamous cell carcinomas of the larynx: Discordance between primary and metastatic tumors
Authors: Sun Paul C. , El‐Mofty Samir K. , Haughey Bruce H. , Scholnick Steven B.
Published: February 2007

The mutational inactivation of suppressor genes, a process required for cancer progression, generates new genetic subclones within a tumor. The allelic losses that frequently unmask these mutations serve not only as markers of the chromosomal locations of these genes but also as clonal fingerprints of the shifting relationships between these genetically heterogeneous cell populations. The rise of the metastasis‐competent subclone to dominance within the primary tumor should be reflected in the similarity of the genetic fingerprints of the primary tumor and its resultant metastases. We have tested this hypothesis by comparing the patterns of allelic loss of individual primary laryngeal squamous cell carcinomas and their resultant cervical lymph node metastases at 16 different genetically polymorphic loci on 15 chromosome arms. Although primary tumors and metastases both frequently lose heterozygosity on the same chromosome arms (3p, 9p, 9q, 13q, and 17p), five of the 12 metastases differed from their primary tumors at one or two of the loci examined. Discordance between the two tumor cell populations from the same patient is suggestive of either subclone heterogeneity within the primary tumor at the time of establishment of the metastasis or further clonal evolution of both tumors after metastasis.
Deletion of 1p loci and microsatellite instability in colorectal polyps
Authors: Lothe Ragnhild A. , Andersen Solveig Norheim , Hofstad Bjørn , Meling Gunn Iren , Peltomäki Päivi , Heim Sverre , Brøgger Anton , Vatn Morten , Rognum Torleiv O. , Børresen Anne‐Lise
Published: February 2007

Previous cytogenetic studies have indicated that a subset of large bowel adenomas have distal 1p deletions. We addressed this question by examining 70 sporadic polyps (63 adenomas, 5 hyperplastic polyps, and 2 polyps of undetermined histology) from 55 patients for alterations at eight loci on the short arm of chromosome 1 and found allele imbalance (A1) or loss of one allele (LOH) in 14 (20%). The locus most frequently changed was MS1, which maps to 1p33‐35. Fluorescence in situ hybridisation with centromeric and telomeric probes for chromosome 1, performed for 11 polyps, did not yield an abnormal number of signals, in accordance with the interpretation that the observed A1 and LOH were the result of interstitial deletions in 1p. Whereas allelic imbalance at five other loci (mapping to 5q, 8p, 10p, 11p and 17q) was found less frequently, and then mainly in large (> 2 cm) tumours, the 1p alterations were equally distributed among small (< 1 cm) and large polyps. They were preferentially found in left‐side tumours. Instability at microsatellite loci—the mutator phenotype—is demonstrated by shifts in the electrophoretic mobility of normal alleles. The mutator phenotype was first associated with hereditary nonpolyposis colorectal cancer but is also occasionally found in sporadic colorectal carcinomas; however, it is still uncertain when in the adenoma‐carcinoma sequence in this type of genomic instability arises. We therefore looked for it at 12 dinucleotide repeat loci and found that seven tumours (six adenomas and one hyperplastic polyp) from seven patients had acquired new alleles not seen in the patients' corresponding normal DNA. Our results suggest that inactivation of a putative suppressor gene distally in chromosome arm 1p is an early event in colorectal tumourigenesis. They also show that microsatellite instability can be detected in large bowel polyps, indicating that this phenomenon, too, probably plays a pathogenic role for some colorectal tumours early in the adenoma‐carcinoma sequence.
Frequent mutations of CDKN2 in primary pancreatic adenocarcinomas
Authors: Bartsch Detlef , Shevlin Douglas W. , Tung William S. , Kisker Oliver , Wells Samuel A. , Goodfellow Paul J.
Published: February 2007

The gene encoding the cell‐cycle regulatory protein p16, CDKN2, is localized on chromosome band 9p21. CDKN2 is frequently deleted or mutated in a variety of tumor cell lines, including pancreatic cancer cell lines and xenografts, as well as in some primary tumors. We examined 32 primary pancreatic adenocarcinomas for CDKN2 mutations and for loss of heterozygosity of 9p21 sequences to assess the role of CDKN2 in pancreatic carcinogenesis. Single‐strand conformation variant analysis (SSCV) and direct sequencing of the variants revealed somatic CDKN2 mutations in 11 of 32 tumors (five frame‐shift mutations, five nonsense mutations, and one missense mutation). One tumor appeared to be characterized by homozygous deletion of CDKN2. These results suggest that CDKN2 plays an important role during tumorigenesis or tumor progression in a significant proportion of pancreatic adenocarcinomas.
Co‐amplification and concomitant high levels of expression of a DEAD box gene with MYCN in human neuroblastoma
Authors: Manohar Chitra F. , Salwen Helen R. , Brodeur Garrett M. , Cohn Susan L.
Published: February 2007

MYCN gene amplification is strongly correlated with poor prognosis in neuroblastoma (NB), the second most common solid pediatric tumor. However, increased MYCN expression seen in tumors that lack MYCN amplification does not correlate with aggressive clinical behavior. Whereas the MYCN gene spans only 7 kb, the MYCN amplicon has been shown to range in size from 350 kb to more than 1 Mb. Given the large size of the amplicon, it is possible that additional genes are co‐amplified in NBs whose expression may contribute to the aggressive phenotype associated with MYCN‐amplified tumors. We isolated a cDNA clone from a human NB library that is identical to DDX1, a gene recently reported to be preferentially expressed in two retinoblastoma cell lines that also express high levels of MYCN. DDX1 belongs to a family of genes that encode DEAD (Asp‐Glu‐Ala‐Asp) box proteins, putative ATP‐dependent RNA helicases implicated in a number of cellular processes involving alterations of RNA secondary structure. We examined the frequency of DDX1 amplification in 15 NB cell lines, 1 neuroepithelioma cell line, and 122 NB tumors by Southern blot analyses, and we found that 7 of 10 MYCN‐amplified cell lines and 27 of 40 (68%) MYCN‐amplified tumors also harbored multiple coples of the DDX1 gene. Amplification of DDX1 was associated with high levels of DDX1 mRNA expression in the NB cell lines and tumors as examined by Northern analysis. Neither DDX1 gene amplification nor enhanced expression was observed in tumors or cell lines that lacked MYCN amplification. Because RNA helicases play important roles in both post‐transcriptional and translational gene regulation, high levels of DDX1 expression consequent to genomic amplification may contribute to the malignant phenotype of a subset of NBs.
Partial chromosome 21 amplification in a child with acute lymphoblastic leukemia
Authors: Coniat Maryvonne Le , Romana Serge P. , Berger Roland
Published: February 2007

Monosomy 21 and metacentric markers corresponding in size to chromosomes 8 to 12 were found as the only clonal chromosomal changes in a child with acute lymphoblastic leukemia (ALL). Chromosome painting with a whole chromosome 21‐specific probe showed that the marker originated from chromosome 21. Fluorescence in situ hybridization with yeast artificial chromosome (YAC) probes to chromosome 21 showed genomic amplification with two, four, or more copies of the probed DNA sequences present on the marker. The most amplified regions of chromosome 21 were centromeric and telomeric to the Down's syndrome region. This observation supports the notion that amplification of only parts of chromosome 21 may be important in the leukemogenic process in spite of the high incidence of complete trisomy 21 in ALL.
Identification of multiple chromosome 12 abnormalities in human testicular germ cell tumors by two‐color fluorescence in situ hybridization (FISH)
Authors: Smolarek Teresa A. , Blough Ruthann I. , Foster Richard S. , Ulbright Thomas M. , Palmer Catherine G. , Heerema Nyla A.
Published: February 2007

The distribution of segments of the short and long arms of chromosome 12 was distinguished by two‐color fluorescence in situ hybridization (FISH) in 27 cytogenetically abnormal testicular germ cell tumors (TGCTs). A 12p‐specific probe was developed by chromosomal microdissection and sequence‐independent polymerase chain reaction (PCR) amplification and was combined with a commercially available whole‐chromosome 12 painting probe. The TGCTs included both i(12p)‐positive and i(12p)‐negative primary tumors and lymph node metastases from patients in clinical stage I or stage II who were not previously treated with chemotherapy. Rearrangements of the short arm of chromosome 12 and overrepresentation of 12p DNA sequences were found in all cases. In addition, cryptic rearrangements of 12p were found in 39% (7/18) of the i(12p)‐positive tumors and in 78% (7/9) of the i(12p)‐negative tumors. Only 7% (2/27) of all tumors had cryptic rearrangements of 12q.
Germline mutations in the RB1 gene in patients with hereditary retinoblastoma
Authors: Liu Zaoxia , Song Yue , Bia Britta , Cowell John K.
Published: February 2007

We have analyzed the 27 exons and the promoter region of the RB1 gene in familial or sporadic bilateral retinoblastoma by using single‐strand conformation polymorphism analysis. For improvement over previous studies, a new set of primers has been designed, which allow for amplification of the coding and splicing sequences only. The positioning of the polymerase chain reaction (PCR) primers was such that the resulting PCR products were of different sizes, which enabled us to analyze two different exons simultaneously and still distinguish between the banding profiles for both (biplex analysis). By using this approach, we were able to identify mutations in 22 new patients, but the overall efficiency of the procedure when we used a single‐pass regimen was only 48%. The mutations were small insertions and deletions and point mutations in roughly equal proportions.
Characterization of regions of chromosomes 12 and 16 involved in nephroblastoma tumorigenesis
Authors: Austruy Estelle , Candon Sophie , Henry Isabelle , Gyapay Gabor , Tournade Marie‐France , Mannens Marcel , Callen David , Junien Claudine , Jeanpierre Cécile
Published: February 2007

There are at least three loci involved in Wilms' tumor (WT) tumorigenesis: WT1 in 11p13, WT2 in 11p15.5, and WT3, as yet unmapped. A compilation of cytogenetic data published for 107 WT revealed that deletion of chromosome 16 and duplication of chromosome 12 occur as frequently as the well‐documented 11p deletions. Allelic imbalance for chromosomes 16 and 12 was investigated in a series of 28 WT. By use of a large panel of restriction fragment length polymorphisms and (CA)n probes, we demonstrated loss of heterozygosity (LOH) for 16q in seven (25%) of the tumors. The whole length of 16q was involved in six of the tumors. Moreover, consistent with a previous report of 16q13 LOH in a sporadic WT and a constitutional breakpoint in a Beckwith‐Wiedemann patient, we map a region of particular interest to between D16S308 and D16S320. The assumption that 16q LOH may be an early event was based on: 1) the detection of 16q LOH in one case of nephroblastomatosis; 2) the presence of a complete (clonal) 16q LOH in a tumor with partial (mosaic) 11p LOH; and 3) 16q LOH as the sole abnormality in one WT. By quantification of chromosome 12 allelic imbalance, we detected duplication in 18% of the total series and in 25% of the sporadic unilateral cases. The common region extended from the centromere to D12S7 in 12q21.1‐q23. We also suggest that the various pathogenetically important loci are not equally involved in the different forms of WT and that their sequential involvement may differ.
Frequent deletions of material from chromosome arm 1p in oligodendroglial tumors revealed by double‐target fluorescence in situ hybridization and microsatellite analysis
Authors: Hashimoto Naoya , Ichikawa Daisuke , Arakawa Yoshiki , Date Kousei , Ueda Satoshi , Nakagawa Yoshio , Horii Akira , Nakamura Yusuke , Abe Tatsuo , Inazawa Johji
Published: February 2007

We undertook a cytogenetic analysis of 29 human brain tumors using double‐target fluorescence in situ hybridization (FISH) and focusing on chromosome arm 1p. One or more tumor suppressor genes in this arm have been suggested to be important in a variety of neuroectodermal tumors. The series included 9 oligodendrogliomas, 4 mixed gliomas, 10 astrocytomas, 4 glioblastomas, and 2 central neurocytomas. We hybridized pericentromeric (1q12) and subtelomeric (1p36) DNA probes to cell nuclei prepared from paraffin‐embedded tissues and observed a strikingly high incidence of deletion of at least part of 1p in oligodendrogliomas (100%) and mixed gliomas (75%). The results of the FISH analyses were confirmed by demonstration of loss of heterozygosity for a microsatellite polymorphism in 10 of the 29 tumors. As well as supporting the feasibility of FISH for detecting allelic deletions in chromosomes from paraffin‐embedded tumor samples, the alteration of 1p reported here will contribute to an understanding of the molecular genetic events in oligodendroglial tumor development.
Microsatellite instability in primary and metastatic lung carcinomas
Authors: Adachi Jun‐Ichi , Shiseki Masayuki , Okazaki Tomoko , Ishimaru Gosei , Noguchi Masayuki , Hirohashi Setsuo , Yokota Jun
Published: February 2007

Fifty‐seven primary lung carcinomas and 35 metastatic lung carcinomas were analyzed for microsatellite instability at 11 different chromosomal loci. Although no instability was detected in 37 small cell lung carcinomas (SCLC), it was frequently detected in non‐small cell lung carcinomas (NSCLC) (16/55, 29%). In NSCLC, the incidence of replication errors (RERs) in metastatic tumors (12/22, 55%) was significantly higher than that in primary tumors (4/33, 12%) (P = 0.0021). Among 10 pairs of primary tumors and corresponding metastases, there were 4 cases which manifested the identical RER phenotypes in both primary and metastatic tumors. In two cases, RER phenotypes were detected in metastatic but not in primary tumors. Never was an RER phenotype found only in a primary tumor but not in the metastases. RERs were detected more frequently in stage III or IV tumors (3/8, 38%) than stage I or II tumors (1/25, 4%) (P = 0.0359). Tumor cells with allelic losses on chromosome arm 3p or 18q tended to have RER phenotypes (P = 0.0432 and P = 0.0187, respectively). The data suggest that microsatellite instability is common in NSCLC but not in SCLC, and that genomic instability appears late in tumor progression and plays an important role in the acquisition of more malignant phenotypes in NSCLC.
Unbalanced translocation t(5;17) in an atypical acute promyelocytic leukemia
Authors: Brunel Véronique , Sainty Danielle , Carbuccia Nadine , Arnoulet Christine , Costello Régis , Mozziconacci Marie‐Jöelle , Simonetti Jacqueline , Coignet Lionel , Gabert Jean , Stoppa Anne‐Marie , Birg Françoise , Lafage‐Pochitaloff Marina
Published: February 2007

Acute promyelocytic leukemia (APL; M3 in the FAB classification) is specifically associated with the t(15;17)(q23;q12) and the consequent formation of a PML/RARA fusion gene. A few cases of APL with a t(11;17)(q23;q12) and a PLZF/RARA fusion gene have recently been reported. In addition, a new variant, t(5;17)(q32;q12), with a RARA rearrangement was described in a child with atypical APL. We report an unbalanced der(5)t(5;17) in an atypical APL case showing unusual dysgranulopoiesis and some M2 features. The breakpoints were difficult to localize precisely on chromosome 5, because the translocation may have occurred on a previous del(5q). The karyotype also showed del(8q) and multiple double‐minutes (dmin). Molecular studies evidenced RARA rearrangement but showed neither PML rearrangement nor PML/RARA fusion. Fluorescence in situ hybridization revealed that the dmin were of chromosome 8 origin and that they accounted for the MYC amplification observed in Southern blots. The patient did very poorly despite chemotherapy and all‐trans retinoic acid (ATRA) treatment. Thus, the t(5;17) could represent a second type of variant translocation in APL that, like the disease associated with t(11;17), does not seem to respond to ATRA therapy. Whereas RARA rearrangement appears sufficient for an APL‐like phenotype, it seems that the presence of a classical PML/RARA is required for typical APL with response to ATRA.
Brain activity during a motor learning task: An fMRI and skin conductance study
Authors: MacIntosh Bradley J. , Mraz Richard , McIlroy William E. , Graham Simon J.
Published: February 2007

Measuring electrodermal activity (EDA) during fMRI is an effective means of studying the influence of task‐related arousal, inferred from autonomic nervous system activity, on brain activation patterns. The goals of this study were: (1) to measure reliable EDA from healthy individuals during fMRI involving an effortful unilateral motor task, (2) to explore how EDA recordings can be used to augment fMRI data analysis. In addition to conventional hemodynamic modeling, skin conductance time series data were used as model waveforms to generate activation images from fMRI data. Activations from the EDA model produced significantly different brain regions from those obtained with a standard hemodynamic model, primarily in the insula and cingulate cortices. Onsets of the EDA changes were synchronous with the hemodynamic model, but EDA data showed additional transient features, such as a decrease in amplitude with time, and helped to provide behavioral evidence suggesting task difficulty decreased with movement repetition. Univariate statistics also confirmed that several brain regions showed early versus late session effects. Partial least squares (PLS) multivariate analysis of EDA and fMRI data provided complimentary, additional insight on how the motor network varied over the course of a single fMRI session. Brain regions identified in this manner included the insula, cingulate gyrus, pre‐ and postcentral gyri, putamen and parietal cortices. These results suggest that recording EDA during motor fMRI experiments provides complementary information that can be used to improve the fMRI analysis, particularly when behavioral or task effects are difficult to model a priori. Hum Brain Mapp, 2007. © 2007 Wiley‐Liss, Inc.
Acute modulation of cortical oscillatory activities during short trains of high‐frequency repetitive transcranial magnetic stimulation of the human motor cortex: A combined EEG and TMS study
Authors: Fuggetta Giorgio , Pavone Enea F. , Fiaschi Antonio , Manganotti Paolo
Published: February 2007

In this study, a combined repetitive transcranial magnetic stimulation/electroencephalography (rTMS/EEG) method was used to explore the acute changes of cortical oscillatory activity induced by intermittent short trains of high‐frequency (5‐Hz) rTMS delivered over the left primary motor cortex (M1). We evaluated the electrophysiological reaction to magnetic stimulation during and 2–4 s after 20 trains of 20‐pulses rTMS, using event‐related power (ERPow) that reflects the regional oscillatory activity of neural assemblies, and event‐related coherence (ERCoh) that reflects the interregional functional connectivity of oscillatory neural activity. These event‐related transformations were for the upper α (10–12 Hz) and β (18–22 Hz) frequency ranges, respectively. For the α band, threshold rTMS and subthreshold rTMS induced an ERPow increase during the trains of stimulation mainly in frontal and central regions ipsilateral to stimulation. For the β band, a similar synchronization of cortical oscillations for both rTMS intensities was seen. Moreover, subthreshold rTMS affected α‐band activity more than threshold rTMS, inducing a specific ERCoh decrease over the posterior regions during the trains of stimulation. For β band, the decrease in functional coupling was observed mainly during threshold rTMS. These findings provide a better understanding of the cortical effects of high‐frequency rTMS, whereby the induction of oscillations reflects the capacity of electromagnetic pulses to alter regional and interregional synaptic transmissions of neural populations. Hum Brain Mapp, 2008. © 2007 Wiley‐Liss, Inc.
Silent and continuous fMRI scanning differentially modulate activation in an auditory language comprehension task
Authors: Schmidt Conny F. , Zaehle Tino , Meyer Martin , Geiser Eveline , Boesiger Peter , Jancke Lutz
Published: February 2007

Sparse temporal acquisition schemes have been adopted to investigate the neural correlates of human audition using blood‐oxygen‐level dependent (BOLD) based functional magnetic resonance imaging (fMRI) devoid of ambient confounding acoustic scanner noise. These schemes have previously been extended to clustered‐sparse temporal acquisition designs which record several subsequent BOLD contrast images in rapid succession in order to enhance temporal sampling efficiency. In the present study we demonstrate that an event‐related task design can effectively be combined with a clustered temporal acquisition technique in an auditory language comprehension task. The same fifteen volunteers performed two separate auditory runs which either applied customary fMRI acquisition (CA) composed of continuous scanner noise or “silent” fMRI built on a clustered temporal acquisition (CTA) protocol. In accord with our hypothesis, the CTA scheme relative to the CA protocol is accompanied by significantly stronger functional responses along the entire superior temporal plane. By contrast, the bilateral insulae engage more strongly during continuous scanning. A post‐hoc region‐of‐interest analysis reveals cortical activation in subportions of the supratemporal plane which varies as a function of acquisition protocol. The middle part of the supratemporal plane shows a rightward asymmetry only for the CTA scheme while the posterior supratemporal plane exposes a significantly stronger leftward asymmetry during the CTA. Our findings implicate that silent fMRI is advantageous when it comes to the exploration of auditory and speech functions residing in the supratemporal plane. Hum Brain Mapp, 2008. © 2007 Wiley‐Liss, Inc.
Approaches to heart valve tissue engineering scaffold design
Authors: Brody Sarah , Pandit Abhay
Published: February 2007

Heart valve disease is a significant cause of mortality worldwide. However, to date, a nonthrombogenic, noncalcific prosthetic, which maintains normal valve mechanical properties and hemodynamic flow, and exhibits sufficient fatigue properties has not been designed. Current prosthetic designs have not been optimized and are unsuitable treatment for congenital heart defects. Research is therefore moving towards the development of a tissue engineered heart valve equivalent. Two approaches may be used in the creation of a tissue engineered heart valve, the traditional approach, which involves seeding a scaffold in vitro, in the presence of specific signals prior to implantation, and the guided tissue regeneration approach, which relies on autologous reseeding in vivo. Regardless of the approach taken, the design of a scaffold capable of supporting the growth of cells and extracellular matrix generation and capable of withstanding the unrelenting cardiovascular environment while forming a tight seal during closure, is critical to the success of the tissue engineered construct. This paper focuses on the quest to design, such a scaffold. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2007
Mechanical testing of fixation techniques for scaffold‐based tissue‐engineered grafts
Authors: Knecht Sven , Erggelet Christoph , Endres Michaela , Sittinger Michael , Kaps Christian , Stüssi Edgar
Published: February 2007

Full‐thickness defects in articular cartilage can be functionally restored by autologous chondrocyte implantation (ACI). In past years, numerous types of scaffolds for tissue‐engineered cartilage implants have been developed and thoroughly characterized. However, the fixation stability of the implants has been rarely investigated despite its well‐known importance for successful therapy. In this study, we have mechanically tested the fixation stability of four commonly used biomaterials for ACI attached by four different fixation techniques (unfixed, fibrin glue, chondral suture, and transosseous suture) in situ. Scaffolds based on polyglycolic acid (PGA) and polyglycolic acid and poly‐L‐lactic acid (PGLA), collagen membranes, and a gel‐like matrix material were fixed within rectangular full‐thickness cartilage defects of 10 × 15 mm2 and loaded in tension until failure. Fibrin glue fixation of PGLA‐scaffolds withstood a load of 2.18 6 ± 0.47 N, chondral sutured PGA‐scaffolds of 26.29 6 ± 1.55 N, and transosseous fixed PGA‐scaffolds of 38.18 6 ± 9.53 N. The PGA‐scaffold could be loaded highest until failure for all fixation techniques compared to the PGLA‐scaffold and collagen membrane. Our findings serve as basis for selecting the most suitable fixation technique for scaffold‐based tissue‐engineered grafts according to the expected in vivo loads. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2007
Natural composite of wood as replacement material for ostechondral bone defects
Authors: Aho Allan J. , Rekola Jami , Matinlinna Jukka , Gunn Jarmo , Tirri Teemu , Viitaniemi Pertti , Vallittu Pekka
Published: February 2007

Deciduous wood, birch, pretreated by a technique combining heat and water vapor was applied for the reconstruction of bone defects in the knee joint of rabbits. It was observed that wood showed characteristic properties to be incorporated by the host bone during observation time of 4, 8, and 20 weeks. The natural channel structure of wood served as a porous scaffold, allowing host bone growth as small islets into the wood implants. The other properties of heat‐treated wood, such as bioactivity, good handling properties, and sufficient biomechanical properties, might be additional favorable factors for the application of wood as a natural composite material for bone and cartilage repair. At the interface of the surfaces of wood and living bone, bonding occurred. The Chemical Interface Model for bonding bone to wood consists of the reactive ions, such as hydroxyl groups OH, and covalent bonding as well as hydrogen bonding, which originate from both wood and bone. The bone tissue trauma, with its reactive Ca2+ and PO ions, proteins, and collagen, available for interaction at ionic and nanolevel, are associated with the complicated chemistry in the cellular response of the early bone healing process. It was concluded that heat‐treated wood acted like a porous biomaterial scaffold, allowing ongrowth and ingrowth of bone and cartilage differentiation on its surface, and demonstrating osteoconductive contact, bonding at the interface. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2007
Construction of antithrombogenic polyelectrolyte multilayer on thermoplastic polyurethane via layer‐by‐layer self‐assembly technique
Authors: Yu Da‐Guang , Lin Wen‐Ching , Lin Chien‐Hong , Yeh Yi‐Hsiang , Yang Ming‐Chien
Published: February 2007

The improvement of hydrophilicity and hemocompatibility of thermoplastic polyurethane (TPU) film was developed using surface modification of polyelectrolyte multilayers (PEMs) deposition. The polysaccharide PEMs included chitosan (CS, as a positive‐charged agent) and dextran sulfate (DS, as a negative‐charged and an antiadhesive agent) that were successfully prepared on the aminolyzed TPU film in a layer‐by‐layer (LBL) self‐assembly manner. X‐ray photoelectron spectroscopy (XPS), field‐emission scanning electronic microscopy (FE‐SEM), and atomic force microscopy (AFM) data will verify the progressive buildup of the PEMs film. The obtained results showed that the contact angle and Zeta‐potential reached the steady value after four bilayers of coating, hence proving that the full coverage of coating with PEM layers was achieved. It could be found that the PEMs‐deposited TPU films with DS as the outmost layer could resist the platelet adhesion and human plasma fibrinogen (HPF) adsorption, thereby prolonging effectively the blood coagulation times. Besides, the results of growth inhibition index (GI) of L929 fibroblast proliferation suggested that the as‐fabricated TPU films were noncytotoxic. Overall results demonstrated that such an easy, valid, shape‐independent, and noncytotoxic processing should be potential for the ion of TPU substrate in the application of hemodialysis or cardiovascular devices. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2007
Enzymatic biodegradable micro‐reactors for therapeutic applications
Authors: Rubio‐Retama J. , Mariño F. Tamimi , López‐Cabarcos E.
Published: February 2007

Poly(ε‐caprolactone) is a well known biocompatible polymer, widely used as drug immobilization systems. In this work poly(ε‐caprolactone) microparticles with average size between 5 and 25 μm have been prepared by O/W emulsion evaporation method. Inside the microparticles, we have encapsulated Glucose Oxidase with the aim of preparing micro‐reactors for enzymatic therapy. These microparticles were structurally characterized and its enzymatic activity analyzed in order to improve the enzyme entrapment. Thus, at the optimum synthesis conditions the enzyme entrapped in the microparticles showed an enzymatic activity of (29.9 ± 2.1)% comparing with the same amount of free enzyme. Moreover the microparticles maintained a (70.4 ± 3.2)% of their initial enzymatic activity after placing them in buffer solution for two weeks. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2007
Degradation, bioactivity, and cytocompatibility of diopside, akermanite, and bredigite ceramics
Authors: Wu Chengtie , Chang Jiang
Published: February 2007

The aim of this study was to investigate the effect of three bioceramics in the CaO‐SiO2‐MgO systems with different composition on the in vitro degradation, bioactivity, and cytocompatibility. The degradation was evaluated through the activation energy of Si ion release from ceramics and the weight loss of the ceramics in Tris‐HCl buffers. The in vitro bioactivity of the ceramics was investigated by analysis of apatite‐formation ability in the simulated body fluid (SBF). The cytocompatibility was evaluated through osteoblast morphology and proliferation. The results showed that the activation energy of Si ion release increased and the degradation decreased from bredigite to diopside ceramics with the increase of Mg content, and the apatite‐formation ability in SBF decreased. The Ca, Si, and Mg containing ionic products from three ceramics could stimulate cell proliferation at lower concentration, and inhibit cell proliferation with the increase of ion concentrations. Furthermore, osteoblasts could adhere, spread, and proliferate on three ceramic disks, and cell proliferation on diopside was more obvious than that on other two ceramic disks. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2007
Influence of extracellular matrix coatings on implant stability and osseointegration: An animal study
Authors: Stadlinger Bernd , Pilling Eckart , Huhle Matthias , Mai Ronald , Bierbaum Susanne , Bernhardt Ricardo , Scharnweber Dieter , Kuhlisch Eberhard , Hempel Ute , Eckelt Uwe
Published: February 2007

Aim of the present study was to test the hypothesis that the application of components of the extracellular matrix such as glycosaminoglycans used as implant surface coatings in combination with collagen, with and without growth factor, can lead to enhanced ossification and thus improve implant stability compared with collagen coatings alone. Twenty miniature pigs received 120 experimental titanium implants in the mandible. Three types of surface coatings were created: (1) collagen type I (coll), (2) collagen type I/chondroitin sulphate (coll/CS), (3) collagen type I/chondroitin sulphate/BMP‐4 (coll/CS/BMP). Periimplant bone formation was assessed within a defined recess along the length axis of the implant. Bone‐implant contact (BIC) and bone volume density (BVD) were determined, using both histomorphometry and synchrotron radiation micro computed tomography (SRμCT). To measure implant stability, resonance frequency analysis was applied after implantation and 1, 3, 7, and 22 weeks after placement. BIC was highest for coll/CS coated implants, followed by coll, p = 0.082. Histomorphometric BVD did not significantly change for any coating. SRμCT analysis showed an increased BVD for collagen coated implants, compared with the other two surface coatings. Implant stability showed a decrease for all coatings up to the third week. At 22 weeks, all coatings showed an increase in stability without reaching their initial level. Highest stability was reached for coll coated implants, p = 0.051. It was concluded that collagen and coll/CS implant coatings have advantageous characteristics for peri‐implant bone formation, compared with the further integration of BMP‐4. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2007