Fatal Primary Capillary Leak Syndrome in a Late Preterm Newborn.

Primary capillary leak syndrome is a rare disease of unknown etiology, characterized by episodes of vascular collapse and plasma extravasation, which may lead to multiple organ failure. Primary capillary leak is extremely rare in children. The authors report a case of a late preterm newborn with fatal capillary leak syndrome of unknown etiology, manifesting as hypotension unresponsive to treatment, extravasation leading to generalised edema, disseminated intravascular coagulation and finally, multiple organ dysfunction syndrome. Aggressive volumotherapy and a combination of inotropes and high doses of terlipressin did not influence systemic vascular collapse and plasma extravasation. The newborn developed multiple organ failure and died on day 27 of life. Investigations performed failed to reveal any specific cause of capillary leak. This is the first report of a fatal primary capillary leak syndrome in a newborn.

Two isoforms of human RNA polymerase III with specific functions in cell growth and transformation.

Transcription in eukaryotic nuclei is carried out by DNA-dependent RNA polymerases I, II, and III. Human RNA polymerase III (Pol III) transcribes small untranslated RNAs that include tRNAs, 5S RNA, U6 RNA, and some microRNAs. Increased Pol III transcription has been reported to accompany or cause cell transformation. Here we describe a Pol III subunit (RPC32beta) that led to the demonstration of two human Pol III isoforms (Pol IIIalpha and Pol IIIbeta). RPC32beta-containing Pol IIIbeta is ubiquitously expressed and essential for growth of human cells. RPC32alpha-containing Pol IIIalpha is dispensable for cell survival, with expression being restricted to undifferentiated ES cells and to tumor cells. In this regard, and most importantly, suppression of RPC32alpha expression impedes anchorage-independent growth of HeLa cells, whereas ectopic expression of RPC32alpha in IMR90 fibroblasts enhances cell transformation and dramatically changes the expression of several tumor-related mRNAs and that of a subset of Pol III RNAs. These results identify a human Pol III isoform and isoform-specific functions in the regulation of cell growth and transformation.

Primary cutaneous T-cell lymphomas do not show specific NAV3 gene deletion or translocation.

The mapping of a balanced t(12;18)(q21;q21.2) translocation in a Sézary syndrome (SS) case led Karenko et al. to identify NAV3 gene (12q21-22) deletion by interphase fluorescence in situ hybridization (FISH) in 15/21 patients with mycosis fungoides (MF) or SS. To determine whether the NAV3 deletion is the result of a specific gene breakpoint, we used FISH with dual-color split or break-apart bacterial artificial chromosome (BAC) probes covering the NAV3 locus. A total of 31 samples (18 skin, 11 blood, 1 lymph node, and 1 spleen) from 24 patients with advanced MF/SS (18 with large-cell transformation) were studied. Chromosome 12 imbalances were analyzed by comparative genomic hybridization (CGH) array with a 3K BAC probes in 24 samples from 22 patients. Both normal FISH and CGH array patterns were observed in 22 samples from 18 patients. In 6 patients, abnormal patterns were observed with an abnormal number of chromosome 12 set in 5 of them. Chromosome 12 structural abnormalities were seen in four of these six patients. An imbalanced FISH pattern between NAV3 and pericentromeric control probes was seen in three patients in accordance with CGH array data (one with a pericentromeric deletion and two with a large 12q deletion including NAV3). No NAV3 specific breakpoint or partial deletion was detected.

Common chromosomal abnormalities in mycosis fungoides transformation.

To identify cytogenetic features of large cell transformation in mycosis fungoides (T-MF), we selected in 11 patients, 16 samples either from skin tumors (13), lymph node (1), or peripheral blood cells (2) collected at the time of the transformation. Comparative genomic hybridization (CGH), G-banding, fluorescence in situ hybridisation (FISH), multicolour FISH (mFISH), and DNA content analysis were used. Fifteen samples displayed unbalanced CGH profiles, with gains more frequently observed than losses. Recurrent chromosomal alterations were observed for chromosomes 1, 2, 7, 9, 17, and 19. The most common imbalances were gain of chromosome regions 1p36, 7, 9q34, 17q24-qter, 19, and loss of 2q36-qter, 9p21, and 17p. In six samples 1p36-pter gain was associated with 9q34-qter gain and whole chromosome 19 gain. In five of these samples whole or partial gain of chromosome 17 was also observed. No specific pattern was seen with regard to the expression of the CD30 antigen by tumor cells. Cytogenetics and/or DNA content analysis of skin tumor cells revealed an abnormal chromosome number in all tested cases (n = 7) with DNA ploidy ranging from hyperdiploid (2.78) to hypotetraploid (3.69) (mean 3.14+/-0.38). Thus, T-MF displayed frequent chromosomal imbalances associated with hypotetraploidy.

Identification, molecular cloning, and characterization of the sixth subunit of human transcription factor TFIIIC.

TFIIIC in yeast and humans is required for transcription of tRNA and 5 S RNA genes by RNA polymerase III. In the yeast Saccharomyces cerevisiae, TFIIIC is composed of six subunits, five of which are conserved in humans. We report the identification, molecular cloning, and characterization of the sixth subunit of human TFIIIC, TFIIIC35, which is related to the smallest subunit of yeast TFIIIC. Human TFIIIC35 does not contain the phosphoglycerate mutase domain of its yeast counterpart, and these two proteins display only limited homology within a 34-amino acid domain. Homologs of the sixth TFIIIC subunit are also identified in other eukaryotes, and their phylogenic evolution is analyzed. Affinity-purified human TFIIIC from an epitope-tagged TFIIIC35 cell line is active in binding to and in transcription of the VA1 gene in vitro. Furthermore, TFIIIC35 specifically interacts with the human TFIIIC subunits TFIIIC63 and, to a lesser extent, TFIIIC90 in vitro. Finally, we determined a limited region in the smallest subunit of yeast TFIIIC that is sufficient for interacting with the yeast TFIIIC subunit ScTfc1 (orthologous to TFIIIC63) and found it to be adjacent to and overlap the 34-amino acid domain that is conserved from yeast to humans.

Large cell transformation of mycosis fungoides: tetraploidization within skin tumor large cells.

Little is known about the molecular or cytogenetic alterations of mycosis fungoides (MF) large cell transformation. We report our findings on chromosomal rearrangement, based on peripheral blood and skin examination before and after cutaneous MF large cell transformation, using both conventional and molecular cytogenetic techniques. Blood cells exhibited a similar hypodiploid karyotype before and after MF transformation. A near-tetraploid karyotype with complex structural rearrangements was established from a skin tumor after MF large cell transformation. Both recurrent chromosome abnormalities and an identical T-cell receptor gamma-chain rearrangement were shared by blood and skin cells, suggesting that MF large cell transformation derived from a common monoclonal ancestor detected at MF stage. A complex hypotetraploid karyotype was established only from the skin tumor, however. MF large cell transformation may be associated with chromosome duplication followed by chromosome losses and interchromosomal rearrangements. Accordingly, additional parallel blood and skin tumor cytogenetic studies are required to further identify the recurrent cytogenetic changes associated with the aggressiveness of the disease after large cell transformation.

Chromosomal imbalances: a hallmark of tumour relapse in primary cutaneous CD30+ T-cell lymphoma.

Primary cutaneous CD30+ large T-cell lymphoma (CD30+ CTCL) is a subset of non-epidermotropic primary cutaneous T-cell lymphoma. Although frequent spontaneous regression may be observed, skin relapses occur frequently. Cytogenetic abnormalities that could play a role in CD30+ CTCL tumour pathogenesis and relapses remain unknown. The identification of recurrent cytogenetic abnormalities is hampered by difficulty in culturing tumours and the lack of CD30+ CTCL serial studies comparing genetic changes both at diagnosis and at relapse. The purpose of this study was to investigate the cytogenetic abnormalities present in a series of 13 CD30+ CTCL samples obtained from nine patients fulfilling both EORTC and WHO diagnostic criteria, by the use of comparative genomic hybridization (CGH). CGH analysis revealed a non-random distribution of genetic imbalances between relapsing and non-relapsing disease. In relapsing disease, chromosomal abnormalities were detected both in the primary tumour and in relapses. The mean number of changes in non-relapsing disease was 0.33 (range 0-1), compared with 6.29 (range 1-16) in relapsing disease. The recurrent chromosomes involved in relapsing disease were chromosomes 6 (86%), 9 (86%), and 18 (43%). While chromosome 9 was mostly affected by gain, chromosomes 6 and 18 mainly contained regions of loss, exclusively on 6q and 18p. The common regions of deletion were 6q21 and 18p11.3. In one patient, we successfully cultured tumour cells from a skin biopsy from a second relapse. The G-banded karyotype was concordant with both CGH and fluorescence in situ hybridization (FISH) results. Although further studies are required to strengthen these data, this CGH analysis demonstrates chromosomal imbalances that may be involved in the pathogenesis of relapsing CD30+ CTCL.