Added value of MRI for the diagnosis of adnexal torsion in children and adolescents after inconclusive ultrasound examination.

PURPOSE: The purpose of this study was to assess the performance of magnetic resonance imaging (MRI) in children and adolescents with suspected adnexal torsion (AT) after inconclusive initial ultrasound examination. MATERIALS AND METHODS: Twenty-eight girls with a mean age of 12±4 (SD) years (range: 1 month to 18years) were included. All had clinically suspected AT and inconclusive initial ultrasound findings followed by pelvic MRI as a second-line imaging modality. The final diagnosis was obtained by surgery or follow-up. Two radiologists blinded to the clinical, ultrasound and surgical data, retrospectively and independently reviewed MRI examinations. Clinical and MRI features associated with AT were searched for using univariate analyses. RESULT: Among the 28 patients, 10/28 patients (36%) had AT and 22/28 (79%) had an ovarian or tubal mass. AT was associated with an age<13years (OR: 10.7; 95% CI: 1.3-148.2) (P=0.022) and a whirlpool sign at MRI (OR: 61.0; median unbiased estimate, 7.2) (P<0.0001). When a mass was present, the best quantitative MRI criteria for AT were mass volume and ovary-corrected volume≥30cm3 (κ=0.72 and 0.61, respectively), mass axis length≥5cm (κ=0.90), and mass surface area≥14 cm2 (κ=0.58), with moderate to almost perfect interobserver agreement. The overall sensitivity, specificity and accuracy of MRI for the diagnosis of AT were 100% (10/10; 95% CI: 69-100), 94% (17/18; 95% CI: 73-100) and 96% (27/28; 95% CI: 82-100) respectively, with perfect interobserver agreement (κ=1). CONCLUSION: In pediatric patients with suspected AT and inconclusive initial ultrasound examination, a strategy including MRI as a second-line imaging modality should be considered if MRI does not delay a potential surgery.

DNMT3A(R882H) mutant and Tet2 inactivation cooperate in the deregulation of DNA methylation control to induce lymphoid malignancies in mice.

TEN-ELEVEN-TRANSLOCATION-2 (TET2) and DNA-METHYLTRANSFERASE-3A (DNMT3A), both encoding proteins involved in regulating DNA methylation, are mutated in hematological malignancies affecting both myeloid and lymphoid lineages. We previously reported an association of TET2 and DNMT3A mutations in progenitors of patients with angioimmunoblastic T-cell lymphomas (AITL). Here, we report on the cooperative effect of Tet2 inactivation and DNMT3A mutation affecting arginine 882 (DNMT3A(R882H)) using a murine bone marrow transplantation assay. Five out of eighteen primary recipients developed hematological malignancies with one mouse developing an AITL-like disease, two mice presenting acute myeloid leukemia (AML)-like and two others T-cell acute lymphoblastic leukemia (T-ALL)-like diseases within 6 months following transplantation. Serial transplantations of DNMT3A(R882H) Tet2(-/-) progenitors led to a differentiation bias toward the T-cell compartment, eventually leading to AITL-like disease in 9/12 serially transplanted recipients. Expression profiling suggested that DNMT3A(R882H) Tet2(-/-) T-ALLs resemble those of NOTCH1 mutant. Methylation analysis of DNMT3A(R882H) Tet2(-/-) T-ALLs showed a global increase in DNA methylation affecting tumor suppressor genes and local hypomethylation affecting genes involved in the Notch pathway. Our data confirm the transformation potential of DNMT3A(R882H) Tet2(-/-) progenitors and represent the first cooperative model in mice involving Tet2 inactivation driving lymphoid malignancies.

Spontaneous biloma: a case report.

A biloma is an encapsulated collection of bile located in the abdomen. It occurs spontaneously or secondary to traumatic or iatrogenic injury to the biliary system. The patient's medical history, symptoms and diagnostic imaging findings suggest the diagnosis, but a definitive diagnosis is provided by drainage and biochemical analysis of the fluid. We report a case of a patient admitted with acute abdominal pain in the right hypochondrium caused by a spontaneous biloma. This is a rare condition, and the reason for the onset was not identified. We discuss the role of the various diagnostic imaging techniques, particularly that of ultrasound.

Preparation of donor corneas: a study of the endothelial population.

PURPOSE: To quantify the endothelial damage in corneal rim excisions prepared in different ways. METHODS: From the Imola branch of Eye Bank of Emilia Romagna, 24 corneal rim excisions which belonged to 12 pairs of enucleated eye globes were selected. The endothelial mortality was quantified by Trypan blue staining and counting the endothelial cells in a central area of about 5 square mm of each cornea. The mate corneas of each pair were prepared in two different ways: one with an epithelium-endothelium cut using a Hanna trephine with an artificial chamber and the other with an endothelium-epithelium cut using a Hanna trephine with punch. After the cut the endothelium was studied again in the same way as described above. RESULTS: The cell mortality in the corneas before and after the epithelium-endothelium cut using the artificial chamber was increased by 0.9% and the percentage of endothelial loss was increased by 3.9+/-6.8%. In the corneas prepared with endothelium-epithelium cut using a punch the mortality before and after the cut increased by 8.8% and the percentage of endothelial loss was 20.7+/-10.9%. CONCLUSIONS: The authors found that in terms of endothelial mortality and endothelial cell density there is less damage to the endothelial population using the epithelium-endothelium cut as compared to the endothelium-epithelium cut.

Functional analyses of the TEL-ARNT fusion protein underscores a role for oxygen tension in hematopoietic cellular differentiation.

The transcription factor hypoxia inducible factor 1 (HIF1), an HIF1alpha-aryl hydrocarbon receptor nuclear translocator (ARNT) dimeric factor, is essential to the cellular response to hypoxia. We described a t(1;12)(q21;p13) chromosomal translocation in human acute myeloblastic leukemia that involves the translocated Ets leukemia (TEL/ETV6) and the ARNT genes and results in the expression of a TEL-ARNT fusion protein. Functional studies show that TEL-ARNT interacts with HIF1alpha and the complex binds to consensus hypoxia response element. In low oxygen tension conditions, the HIF1alpha/TEL-ARNT complex does not activate transcription but exerts a dominant-negative effect on normal HIF1 activity. Differentiation of normal human CD34+ progenitors cells along all the erythrocytic, megakaryocytic and granulocytic pathways was accelerated in low versus high oxygen tension conditions. Murine 32Dcl3 myeloid cells also show accelerated granulocytic differentiation in low oxygen tension in response to granulocyte colony-stimulating factor. Interestingly, stable expression of the TEL-ARNT in 32Dcl3 subclones resulted in impaired HIF1-mediated transcriptional response and inhibition of differentiation enhancement in hypoxic conditions. Taken together, our results underscore the role of oxygen tension in the modulation of normal hematopoietic differentiation, whose targeting can participate in human malignancies.

A new recurrent and specific cryptic translocation, t(5;14)(q35;q32), is associated with expression of the Hox11L2 gene in T acute lymphoblastic leukemia.

FISH identified a cryptic t(5;14)(q35;q32) in T acute lymphoblastic leukemia (ALL), whereas it was not observed in B ALL samples. This translocation is present in five out of 23 (22%) children and adolescents with T ALL tested. RanBP17, a gene coding for a member of the importin beta protein family, and Hox11Like2, an orphan homeobox gene were mapped close to the chromosome 5 breakpoints and CTIP2, which is highly expressed during normal T cell differentiation, was localized in the vicinity of the chromosome 14 breakpoints. The Hox11L2 gene was found to be transcriptionally activated as a result of the translocation, probably under the influence of CTIP2 transcriptional regulation elements. These data establish the t(5;14)(q35;q32) as a major abnormality, and Hox11 family member activation as an important pathway in T ALL leukemogenesis.

Characterization of a novel ETS gene, TELB, encoding a protein structurally and functionally related to TEL.

The TEL/ETV6 gene is located at 12p13 and is frequently involved in chromosomal translocations in human malignancies usually resulting in the expression of fusion proteins between the amino terminal part of TEL, and either unrelated transcription factors or protein tyrosine kinases. We report here a novel gene named TELB which is located on human chromosomal band 6p21 and encodes a protein highly related to TEL. TELB is widely expressed in different tissues and, similarly to TEL encodes a sequence-specific transcriptional repressor.

Different combinations of genetic/epigenetic alterations inactivate the p53 and pRb pathways in invasive human bladder cancers.

Inactivation of both the pRb (pRb-cyclin D1/cyclin-dependent kinase 4/6-p16) and p53 (p53-p21(WAF1)-p14(ARF)) pathways is thought to be essential for immortalization in vitro and malignant transformation in vivo. We identified different combinations of pRb and p53 pathway alterations in 12 invasive transitional cell carcinomas (TCCs) and addressed the functional significance of the different combinations observed. Results showed four combinations of alterations including -pRb/-p53 (ie., pRb inactivated in the pRb pathway and p53 inactivated in the p53 pathway; four TCCs), -p16/-p53 (four TCCs), -p16/-p21(WAF1) (one TCC), and -p16/ -p14(ARF) (two TCCs). These groups include two new combinations (ie., -p16/-p53 and -p16/-p21(WAF1)) not reported previously for TCCs. An alteration in the key components of the p53 pathway was not detected in one invasive TCC that had inactivated p16. Note that all four TCCs with inactivated pRb had mutant p53; thus, the combinations of -pRb/ -p21(WAF1) and -pRb/-p14(ARF) were not observed. Only two of eight TCCs with altered p16 had concomitant p14(ARF) loss, demonstrating that simultaneous inactivation of these two 9p21INK4a tumor suppressor genes is not obligatory. To determine the biological phenotypes of TCCs with different combinations of pRb and p53 pathway alterations, their downstream responses to gamma radiation were studied in vitro. As expected, none of eight TCCs with mutant p53 responded to gamma radiation by elevation of p53, p21(WAF1), or mdm2 or by cell cycle arrest. Only two of four TCCs with wild-type p53 and wild-type pRb (the combination of -p16/-p14(ARF)) showed normal downstream responses to gamma radiation and underwent cell cycle arrest. Two TCCs with wild-type pRb and wild-type p53 (the combination of -pl6/-p21(WAF1) and one TCC with -p16) failed to show cell cycle arrest in response to radiation. This was attributed to the absence of p21(WAF1) in one TCC. In summary, these data support a model of invasive bladder cancer pathogenesis in which both the pRb and p53 pathways are usually inactivated and the biology of the tumor is impacted by the mechanism of their inactivations.

The t(1;12)(q21;p13) translocation of human acute myeloblastic leukemia results in a TEL-ARNT fusion.

The TEL/ETV6 gene is located at 12p13 and encodes a member of the ETS family of transcription factors. Translocated ETS leukemia (TEL) is frequently involved in chromosomal translocations in human malignancies, usually resulting in the expression of fusion proteins between the amino-terminal part of TEL and either unrelated transcription factors or protein tyrosine kinases. We have characterized a t(1;12)(q21;p13) translocation in an acute myeloblastic leukemia (AML-M2). At the protein level, the untranslocated TEL copy and, as a result of the t(1;12) translocation, a fusion protein between TEL and essentially all of aryl hydrocarbon receptor nuclear translocator (ARNT) are expressed. The involvement of ARNT in human leukemogenesis has not been previously described. The ARNT protein belongs to a subfamily of the "basic region helix-loop-helix" (bHLH) protein that shares an additional region of similarity called the PAS (Per, ARNT, SIM) domain. ARNT is the central partner of several heterodimeric transcription factors, including those containing the aryl hydrocarbon (dioxin) receptor (AhR) and the hypoxia-inducible factor 1alpha (HIF1alpha). Our results show that the TEL-ARNT fusion protein is the crucial product of the translocation and suggest that interference with the activity of AhR or HIF1alpha can contribute to leukemogenesis.

Molecular analysis of chromosomal breakpoints in three examples of chromosomal translocation involving the TEL gene.

The TEL gene is involved in several chromosomal abnormalities of human hematopoietic malignancies. The chromosome 12 breakpoints frequently lie within the fifth intron of the gene, particularly in the most frequent translocation involving TEL, the t(12;21)(p13;q22). In order to search for a peculiar mechanism involved in the genesis of these translocations, we have established the sequence of two t(12;21) and a t(9;12)(q24;p13) breakpoints. Our data do not reveal the involvement of VDJ recombinase activity or Alu sequences but favor the occurrence of staggered breaks and DNA repair activity in the genesis of these translocations.

The human p19ARF protein encoded by the beta transcript of the p16INK4a gene is frequently lost in small cell lung cancer.

The p16IN4/CDKN2/MTS1 gene encodes two structurally different proteins: a cyclin-dependent kinase inhibitor called p16INK4a, which regulates retinoblastoma protein-dependent G1 arrest, and a cell cycle inhibitor designated p19ARF, which arrests cell growth in G1-S and also in G2-M. Whereas inactivation of p16INK4a has been described as a frequent event in lung cancer, the current function of p19ARF is still poorly understood. We have examined the expression of the human p19ARF (hp19ARF) protein in a large series of lung cancers using immunohistochemistry and showed that the protein was more frequently lost in high-grade neuroendocrine (NE) lung tumors (large cell NE carcinoma and small cell lung carcinoma; 51 of 78, 65%) than it was in non-small cell lung cancer (25 of 101, 25%). No deleterious mutation was found in exons 1beta and 2 of hp19ARF in those NE tumors with negative immunoreactivity, and a beta transcript was detected in the majority of them. Concomitant absence of hp19ARF and retinoblastoma proteins was frequently detected in high-grade NE lung tumors, whereas no relationship could be found between the status of hp19ARF and p53 proteins in those tumors. These results are consistent with an alternative growth suppressor function for hp19ARF in NE lung cancer that is distinct from that of p16INK4a. Moreover, the frequent uncoupling between the beta transcript and the hp19ARF protein suggests a novel mechanism of inactivation at the translational level.

The human protein p19ARF is not detected in hemopoietic human cell lines that abundantly express the alternative beta transcript of the p16INK4a/MTS1 gene.

The p16/MTS1/CDKN2 gene on human chromosome band 9p21 encodes two unrelated proteins: p16INK4a, a specific inhibitor of the cyclin D-dependent kinases CKD4 and CDK6, and the structurally unrelated p19ARF protein that arrests cell growth in G1/S and also in G2/M. By use of polyclonal antibodies, the human p19ARF (hp19ARF) protein has been identified in the nucleus of various cells including normal cultured fibroblasts. The level of this protein did not fluctuate throughout the cell cycle and was more elevated in fibroblasts with limited or arrested growth, suggesting that p19ARF accumulated in presenescent or senescent cells. Interestingly, hp19ARF was not detected in several hemopoietic tumor cell lines (mainly of B-type lymphoid origin) that expressed abundant amounts of the p16beta transcript. This finding indicates that in certain tumors, the expression of hp19ARF RNA and protein may be uncoupled. Furthermore, it suggests that disruption of a translational mechanism may be involved in the inactivation of hp19ARF.

A new breakpoint, telomeric to TEL/ETV6, on the short arm of chromosome 12 in T cell acute lymphoblastic leukemia.

Abnormalities of the short arm of chromosome 12 frequently involve the TEL/ETV6 gene in acute leukemias. In two cases of T cell acute lymphoblastic leukemia with translocation t(12;14)(p13;q11) and t(7;12)(q35;p13), respectively, the breakpoints were located telomeric to the TEL/ETV6 locus. Further fluorescence in situ hybridization (FISH) studies showed that the breakpoint was located between two markers, FGF6 (centromeric) and D12S983 (telomeric) on 12p in both patients. This result suggests that a new chromosomal breakpoint can nonrandomly involve rearrangements in T cell malignancies. The breakpoint on chromosome 14 was localized centromeric to the TRCA/D locus.

The I protein of the heterogeneous nuclear ribonucleoprotein complex is a novel dog nuclear autoantigen.

In eukaryotic cells, heterogeneous nuclear RNA is associated with a set of abundant nuclear proteins to form complex ribonucleoprotein structures (hnRNP). Autoantibodies to hnRNP G protein have been previously reported in German shepherd dogs with lupus-like syndrome. In the present study, we describe the characterization of a novel antigen recognized by a serum from a schnauzer dog with a non-erosive polyarthritis. The autoantibodies give, by indirect immunofluorescence, a nuclear pattern with staining close to one of the nucleoli. Immunoblotting and immunoprecipitation data reveal that the autoantigens are in fact two closely related basic proteins (average pI 8.7) with apparent molecular weights of 56 kDa (p56) and 59 kDa (p59). The results of immunoprecipitation with anti-hnRNP antibodies and DNA affinity column chromatography strongly suggest that these autoantigens correspond to hnRNP I proteins. This point was confirmed by cloning and sequencing a cDNA clone encoding the complete sequence of the antigens. In addition, we found that anti-hnRNP I antibodies preferentially stain certain loops of the Pleurodeles waltl lampbruch chromosomes. These data, added to previous ones on anti-p43/hnRNP G protein in German shepherd dogs with lupus-like syndrome, confirm the interest of this category of antibodies to hnRNP proteins in autoimmune disorders.

Dual localization of the human gene encoding hnRNP I/PTB protein to chromosomes 19p13.3 and 14q23.

A cDNA probe representative of the human hnRNP I/PTB gene was used to perform fluorescence in situ hybridization (FISH) on metaphases of human chromosomes. A new localization was found on band 19p13.3 in addition to the previously reported localization to band 14q23. Identical results were obtained when FISH analysis was repeated with probes covering different parts of the hnRNP I cDNA clone. This supported the notion that most, if not all, of the sequences of the different parts of this clone are present on both chromosomes. Moreover, Southern blot analysis of DNAs from interspecies somatic hybrids containing chromosomes 19 and 14 revealed that the whole hnRNP I cDNA probe generated very similar patterns in each hybrid DNA. These data suggest that two closely related copies of the hnRNP I gene exist in the human genome.

Inactivation of the P16INK4/MTS1 gene by a chromosome translocation t(9;14)(p21-22;q11) in an acute lymphoblastic leukemia of B-cell type.

We have reported previously a preliminary study of a t(9;14)(p21-22; q11) in B-cell acute lymphoblastic leukemia. This translocation had rearranged the TCRA/D locus on chromosome band 14q11 and the locus encoding the tumor suppressor gene P16INK4/MTS1 (P16) on band 9p21 (D. Duro et al., Oncogene, 11: 21-29, 1995). In the present report, the breakpoints were precisely localized on each chromosome partner. On the 14q- derivative, the sequence derived from chromosome 9 was interrupted at 1.0 kb upstream of the first exon of P16, close to a consensus recombination heptamer, CACTGTG. In addition, the chromosome 14 breakpoint was localized at the end of the TCRD2 (delta 2) segment, and 22 residues with unknown origin were present at the translocation junction. On the 9p+ derivative, chromosome 9 sequences were in continuity with those displaced onto chromosome 14, and the 14q11 breakpoint was located within TCRJA29 segment. These features are consistent with aberrant activity of the TCR gene recombinase complex. Although all three coding exons of P16 were displaced onto the chromosome 14q-derivative, no P16 transcript was detected in the leukemic cells. Because the region spanning the P16 exon 1 was not inactivated by methylation and because the other P16 allele was deleted, the implication is that the chromosome breakpoint was likely to disrupt regulatory elements involved in the normal expression of the gene. As a whole, then, our results show that translocations affecting band 9p21 can participate to the inactivation of P16, thus justifying a systematic survey of translocations of the 9p21 band in acute lymphoblastic leukemia.

A new type of p16INK4/MTS1 gene transcript expressed in B-cell malignancies.

Chromosome band 9p21-22 is frequently altered by nonrandom abnormalities, mainly deletions, in hemopoietic malignancies of the lymphoid lineage. We have analysed a translocation t(9;14)(p21-p22;q11) in a B-cell type acute lymphoblastic leukemia. Location of the 14q11 breakpoint within the TCR-alpha/delta locus allowed the isolation of a fusion transcript composed of a 3' segment containing part of the constant region of the TCR-alpha gene and a 5' segment from chromosome 9, designated 0.18. This 0.18 segment was also part of cDNAs isolated from two tumoral B-cell lines (RPMI-8226, Raji). In both cases, 0.18 was juxtaposed 5' to a sequence corresponding to exons 2 and 3 of the p16INK4/MTS1 gene which is located on band 9p21-22. Unexpectedly, none of the two ATG codons found in 0.18 was in phase with that of the exons 2 and 3 of p16INK4/MTS1. Furthermore, in vitro translation product of a RPMI-8226 cDNA clone generated a product that was not immunoprecipitated by antibodies specific of the C-terminal end of the p16INK4/MTS1 protein. Evidence for similar transcripts in non tumoral lymphoid B cells (unstimulated peripheral blood lymphocytes (PBL) and lymphoblastoid cell lines) were obtained by using amplimers representative of the 0.18 segment and the p16INK4/MTS1 exon 2. Altogether, these data are consistent with the existence of a new type of p16INK4/MTS1 transcript whose significance is discussed.

A novel class of zinc finger/leucine zipper genes identified from the molecular cloning of the t(10;11) translocation in acute leukemia.

A novel class of conserved transcription factors has been identified from the molecular cloning of AF10, the gene involved in the t(10;11)(p12;q23) translocation of acute myeloid leukemias. AF10 encodes a 109-kD protein of 1,027 amino acids and contains an N-terminal zinc finger region and a C-terminal leucine zipper. These structures have been found to be conserved in sequence and position in three other proteins, AF17, BR140, and a previously unrecognized Caenorhabditis elegans gene, provisionally named CEZF. The overall structure, level of sequence conservation, and expression pattern suggest that these genes encode a new class of transcription factors, some of which are targets for chromosomal translocation in acute leukemia.