Anna Montaldi

large-cell Medulloblastomas : A Distinct Variant with Highly Aggressive Behavior

&NA; We present four cases of infantile cerebellar neoplasms composed of cells with large vesicular nuclei with prominent nucleoli. All four cases were strongly immunoreactive for synaptophysin, and one case showed immunoreactivity for neurofilaments. Filter hybridization for N‐myc and c‐myc oncogenes showed a 27‐fold c‐myc amplification in one case. The cytogenetic analysis in this case showed Double‐Minutes and isochromosome 17q. An intracerebral xenograft in nude mice obtained from one such tumor showed a similar morphology to that of the original tumor as well as strong immunoreactivity for synaptophysin and neurofilaments. All the neoplasms were characterized by highly aggressive behavior leading to early cerebrospinal fluid dissemination despite radiotherapy and chemotherapy. We conclude that large‐cell medulloblastoma represents a distinct and more aggressive variant of medulloblastoma that requires more aggressive therapy.

Genetic effects of chromium compounds

Seven different test systems were utilized to investigate the genetic activity of chromium compounds: infidelity of DNA replication in vitro by DNA pol alpha from calf thymus, damage of DNA detected by alkaline elution in treated mammalian cells or in DNA purified and treated in vitro, DNA repair synthesis in mammalian cells in vitro detected by autoradiography or scintillation counting after labelling with [3H]dThd, gene mutations in the Salmonella typhimurium Ames test, gene mutations (6TG resistance) in cultured hamster cells, sister-chromatid exchanges in different rodent cell cultures, and transformation to anchorage-independent growth of hamster cells in vitro (soft-agar assay). Potassium dichromate and chromium chloride were used as water-soluble Cr(VI) and Cr(III) salts. Several reference mutagens (EMS, MMS, MMC, 4NQO) were included in the single tests as positive controls. Cr(VI) was active in all the tested systems, except in the induction of DNA damage and DNA repair synthesis in cultured cells. Cr(III), on the other hand, was absolutely inactive unless a direct interaction with purified DNA was permitted by the test conditions. The relevance of data from the various tests to the understanding of the mechanisms of the genotoxic activity of chromium is discussed. Effects other than the direct interaction of Cr(III) with DNA are inferred, which can cause infidelity of the DNA polymerase functions.

Clastogenic effects of chromium on human lymphocytes in vitro and in vivo.

Abstract The induction of SCEs and chromosome aberrations in PHA-stimulated human lymphocytes treated in vitro for 70 h with Cr(VI) (potassium dichromate, K 2 Cr 2 O 7 ) or Cr(III) (chromium chloride, CrCl 3 ) was determined. A clear dose-dependent increase of the frequency of SCEs is induced by Cr(VI), a 2.5-fold increase being obtained with 10 −5 M K 2 Cr 2 O 7 . Cr(III) is, on the other hand, absolutely inactive even when used at sub-toxic concentrations (10 −3 M CrCl 3 ). The overall frequency of chromosome aberrations is significantly increased by Cr(VI) above 2.5 × 10 −7 M K 2 Cr 2 O 7 , and chromatid-type aberrations (gaps and breaks) are the most frequent. 100 times higher concentrations of CrCl 3 are required to increase the frequency of chromosome aberrations. A difference of the same order of magnitude is observed for the cytotoxic activity of Cr(VI) and Cr(III), which is characterized by a slowing down of the mitotic cycle reflected by increased 1st-division and decreased 3rd-division metaphases. By treating unstimulated lymphocytes in vitro with Cr(VI) in the G 0 phase, an increase in the frequency of SCEs is produced significantly lower than that obtained on stimulated lymphocytes. Cr(VI) treatments performed at different intervals after stimulation show that the sensitivity of lymphocytes to the induction of SCEs by CR(VI) depends on the phase of the cell cycle, highest frequencies of SCEs being obtained when the cells enter the S phase of DNA replication. The frequency of SCEs in lymphocytes of 12 workers exposed to Cr(VI) (chromic acid fumes in a plating works) is significantly higher than that of 10 control donors. In particular, all the 7 youngest workers, although the most recently engaged in chromium plating, show significantly increased SCE frequencies.

A mesenchymal chondrosarcoma of a child with the reciprocal translocation (11;22)(q24;q12)

The reciprocal translocation (11;22)(q24;q12) was observed in a seven day culture from a mesenchymal chondrosarcoma of the bone, a tumor not characterized cytogenetically so far. We suggest that because of the presence of a similar cytogenetic abnormality, mesenchymal chondrosarcoma may belong to the wide group of t(11;22)-small round cell tumors.

Cytogenetic analysis of hepatoblastoma: Hypothesis of cytogenetic evolution in such tumors and results of a multicentric study

Hepatoblastoma is a rare pediatric malignant tumor of the liver. Previous cytogenetic reports are sporadic. We karyotyped nine consecutive hepatoblastomas from the Italian centers participating in a multicentric study on hepatic tumors (SIOPEL 1). Six cases showed abnormal karyotypes. The most common abnormalities were trisomies of chromosomes 2 and 20. Four cases showed abnormalities of chromosome 1. On the basis of findings, we speculate the possibility of a cytogenetic evolutive pattern of hepatoblastomas.

Cytogenetic t(11;17)(q13;q21) in a pediatric ependymoma. Is 11q13 a recurring breakpoint in ependymomas?

Cytogenetic studies on a supratentorial ependymoma from a 1-year-old boy showed a t(11;17)(q13;q21). This is the second ependymoma reported with a rearrangement at 11q13; to our knowledge the 11q13 is the first recurring breakpoint reported in ependymoma.

Effects of nitrilotriacetic acid on the induction of gene mutations and sister-chromatid exchanges by insoluble chromium compounds

The influence of nitrilotriacetic acid trisodium salt (NTA) on the mutagenic and clastogenic activity of several water-insoluble or poorly soluble chromium compounds was determined by means of the Salmonella/microsome assay (plate test on TA100 strain) and the sister-chromatid exchange (SCE) test in mammalian cell cultures (CHO line). NTA in itself did not induce gene mutations nor did it increase the frequency of SCE. Cr(VI) compounds (Pb, Ba, Zn, Sr and Ca chromates) and an industrial Cr(VI) pigment, chromium orange (containing PbCrO4 PbO), were inactive or scarcely active mutagens in the Salmonella/microsome test when dissolved in water, but they were increasingly mutagenic when solubilized by 0.5 N NaOH or NTA (10 or 100 mg/ml). Also, the mutagenic activity of Cr(VI), contaminating an industrial Cr(III) pigment (chromite), was slightly enhanced by NTA. Mutagenicity of chromates was correlated with the amounts of Cr(VI) solubilized by NTA or alkali, as determined by the colorimetric reaction with diphenylcarbazide and atomic absorption spectrophotometry, and was decreased by incubation with microsomes, due to reduction of Cr(VI) to the genetically inactive Cr(III) form. In the SCE assay, the insoluble or poorly soluble Ba, Zn, Sr and Ca chromates and the insoluble Cr(VI) pigments zinc yellow (containing ZnCrO4 Zn(OH2], chromium yellow and molybdenum orange (both containing PbCrO4) were directly clastogenic due to cellular endocytosis taking place in prolonged treatments, and NTA significantly increased their chromosome-damaging activity.

Induction of sister-chromatid exchanges in human lymphocytes exposed in vitro and in vivo to therapeutic ultrasound

The induction of sister-chromatid exchanges (SCEs), chromosomal aberrations and cell-cycle delay was determined in human lymphocytes after treatment in vitro and in vivo with therapeutic ultrasound (u.s.). In vitro treatments (1 W/cm2; 0.860 MHz; for 40-160 sec) were performed on unstimulated lymphocytes from 9 donors: a statistically significant, dose-dependent increase in SCE frequency was produced, whereas no induction of chromosomal aberrations nor alteration of the distribution of 1st, 2nd and 3rd division metaphases were observed. The same increase in the frequency of SCEs was detected by treating in vitro stimulated lymphocytes with u.s. The effects of in vivo exposure to u.s. were detected on lymphocytes from 10 patients before, during and after u.s. therapy (0.6-1.0 W/cm2; 0.860 MHz; from 8 to 20 applications lasting 5-6 min each). SCE frequency was statistically significantly increased in all patients at mid-therapy, without a further increase during the second half of therapeutic cycle, and was restored to pretreatment level 3 months after the end of u.s. therapy. No increase in chromosomal aberrations was noticed during and after u.s. therapy, whereas erratic delays of the cell cycle were observed, not clearly related to u.s. application or SCE levels. A linear relationship was found between SCE frequency and age in 21 healthy donors.

A NOVEL VARIANT TRANSLOCATION t(2;13) (p23;q34) IN Ki‐1 LARGE CELL ANAPLASTIC LYMPHOMA

Recently a large cell lymphoma, strongly reacting with Ki-1 (CD 30) monoclonal antibody (MoAb), has been described (Stein et al, 1985). This entity, called Ki-1 large cell anaplastic lymphoma, has a variable pattern of cell surface antigens, T or B phenotype, but presents distinctive clinical and morphological features (Kadin et al. 1986). In the last 2 years a few cases of successfully karyotyped Ki-1 lymphoma have been reported in different series. In all of them a translocation involving an identical breakpoint 5q3 5 has been found (Mason et a], 1990). A t(2:5), and a few variants which share a common breakpoint at 5q35, were previously reported in cases of haematologic disease designated as malignant histiocytosis (Benz-Lemoine et ul, 19 88); these cases, however, when studied with Ki-l monoclonal antibody, showed a constant expression of this antigen (Mason et al, 1990). On the other hand, this abnormality has never been observed in other lymphoma subtypes (Le Beau et al, 1989). These results gave support to the hypothesis of a specific association between a translocation involving 5q3 5 and CD30-positive lymphoid neoplasia. Here, we report a case of Ki-1 large cell anaplastic lymphoma which presents multiple abnormalities with a novel variant translocation t(2:13) (p23;q34). The breakpoint at 2p23 is the same as the reported cases of Ki-1 lymphoma, but differs from the literature in that our case shows no microscopic involvement of 5q35 (Fig 1). LV, an 11-year-old boy, was admitted to our ward in October 198 5 with diffuse lymphadenopathy and prolonged fever. His general health had been good with no previous history of note until 1 month prior to admission, when he developed a tonsillitis with a high, sustained fever, and diffuse lymphadenopathy (maximum lymph node diameter 0.5 cm). A biopsy of an enlarged lymph node was performed and revealed the presence of abnormal giant cells. For this reason the patient was referred to our Department. The general examination was normal apart from the diffuse lymphoadenopathy. The chemical and haematological investigations were normal except for mild hyperfibrinogenaemia. Chest X-ray was normal. The total body computerized tomography (CT) scan revealed the presence of small lymph nodes grouped together in the mediastinum and in the retroperitoneum. The patient underwent laparotomy for node and liver biopsy. The histology of the node showed an infiltration of large cells, the diagnosis being ‘malignant histiocytosis’. No liver involvement was found. Bone marrow aspiration and the cerebrospinal fluid were negative for tumoural infiltration. We achieved complete remission with chemotherapy. Two months after the suspension of chemotherapy in 1987 skin lesions appeared. The skin biopsy confirmed the malignant histiocytosis relapse. The lesions disappeared after treatment with VP-16 to reappear in August 1989, 1 year after stopping therapy for the second time. At this time a new skin biopsy was done and cytochemistry and immunohistochemical and cytogenetic studies were performed. Immunophenotyping was done on frozen sections by the alkaline phosphatase-anti-alkaline phosphatase (APAAP) method using a range of monoclonal antibodies against leucocyte associated marker. Cytogenetic

B-cell receptor configuration and adverse cytogenetics are associated with autoimmune hemolytic anemia in chronic lymphocytic leukemia

The development of autoimmune hemolytic anemia (AIHA) in patients with chronic lymphocytic leukemia (CLL) is associated with specific biological features. The occurrence of AIHA was hereby investigated in a retrospective series of 585 CLL patients with available immunoglobulin heavy chain variable (IGHV) gene status. AIHA occurred in 73 patients and was significantly associated with an IGHV unmutated (UM) status (P < 0.0001) and unfavorable [del(17)(p13) and del(11)(q23)] cytogenetic lesions (P < 0.0001). Stereotyped HCDR3 sequences were identified in 29.6% of cases and were similarly represented among patients developing or not AIHA; notably, subset #3 was associated with a significantly higher risk of AIHA than the other patients (P = 0.004). Multivariate analysis showed that UM IGHV, del(17)(p13) and del(11)(q23), but not stereotyped subset #3, were the strongest independent variables associated with AIHA. Based on these findings, we generated a biological risk score for AIHA development according to the presence of none (low risk), one (intermediated risk), or two (high risk) of the independent risk factors. Overall, our data indicate that UM IGHV status and/or unfavorable cytogenetic lesions are associated with the risk of developing secondary AIHA in CLL patients and suggest a possible role of specific stereotyped B‐cell receptor subsets in a proportion of cases. Am. J. Hematol. 2013.