Bioactive long chain N-acylethanolamines in five species of edible bivalve molluscs. Possible implications for mollusc physiology and sea food industry

Several long chain N-acylethanolamines, including the proposed endogenous ligands of cannabinoid receptors, anandamide (N-arachidonoylethanolamine, C20:4 NAE) and N-palmitoylethanolamine (C16:0 NAE), as well as some of their putative biosynthetic precursors, the N-acyl-phosphatidylethanolamines, were found in lipid extracts of five species of bivalve molluscs, including Mytilus galloprovincialis, commonly used as sea food. The amounts of these metabolites, the most abundant being C16:0 NAE and N-stearoylethanolamine, appeared to increase considerably when mussels were extracted 24h post-mortem, but were not significantly affected by boiling the tissue prior to extraction. In particulate fractions of homogenates from Mytilus, where the existence of a highly selective cannabinoid receptor with an immunomodulatory function has been previously described, an enzymatic activity capable of catalyzing the hydrolysis of C20:4 NAE amide bond, and displaying similar pH dependency and inhibitor sensitivity profiles as the recently characterized 'fatty acid amide hydrolase' was found. The enzyme Km and Vmax for C20:4 NAE were 29.6 microM and 73 pmol/mg protein/min, respectively. These findings support the hypothesis that C20:4 NAE, never reported before in the phylum Mollusca, may be a mollusc physiological mediator, and suggest that edible bivalves may be a dietary, albeit limited, source of C16:0 NAE, whose anti-inflammatory properties, when administered orally in amounts higher than those reported here, have been previously reported.

Dissolution of trace metals from lava ash: influence on the composition of rainwater in the Mount Etna volcanic area

Dissolution of trace metals from lava ash of the Mount Etna volcano in aqueous suspensions is studied as a function of solution pH and aerosol mass loading. The rate of dissolution and the final concentration increase with decreasing pH. Leaching experiments are found to be consistent with the observations of these metals in rainwater of the volcanic area. Elements such as Fe and Mn are important in the aqueous oxidation of SO(2) which increases the acidity of the rainwater. Leaching of Na, Ca, K, Fe and Mg may have a buffering effect in reacting with cloud and aerosol droplets.

Different serological examinations in cystic fibrosis patients: response to Pseudomonas aeruginosa St-Ag

Crossed immunoelectrophoresis (CIE), enzyme linked immunosorbent assay (ELISA) and immunoblotting (IMB) were used to look for the presence of anti-bodies to Pseudomonas aeruginosa standard antigen in the sera of cystic fibrosis patients with intermittent (CF +/- P) and chronic (CF + P) colonization. Our results show that CIE is too complex a method to use when monitoring the infection over time, that with ELISA a correlation with the patient's clinical status may be made and that IMB can evidence an early, albeit low, reaction in the CF +/- P patient.

Infant acute leukemias show the same biased distribution of ALL1 gene breaks as topoisomerase II related secondary acute leukemias

The ALL1 gene (also called MLL, HRX, or Htrx1) at the cytogenetic band 11q23 is consistently altered by chromosome rearrangements in acute leukemias (ALs) of early infancy, in ALs developed after exposure to topoisomerase (topo) II-inhibitory drugs, and in a small subset of de novo ALs in children and adults. Because exposure to natural or medicinal substances blocking topo II during pregnancy have been proposed as etiological agents for infant leukemia, we have compared the distribution of ALL1 gene breakpoints in infant leukemias with an altered ALL1 gene configuration to those in secondary leukemia associated with prior exposure to topo II targeting drugs and in reference to the major topo consensus binding site in exon 9. ALL1 gene breakpoint distribution was determined by Southern blot hybridization and/or reverse transcription-PCR of the ALL1/AF4 fusion cDNA in 70 patients. Using restriction enzyme analysis, the 8.3-kb ALL1 breakpoint cluster region was divided in a centromeric portion of 3.5 kb (region A) and telomeric portion of a 4.8 kb (region B). ALL1 breakpoint were located in region A in 8 of 28 (28.5%) cases of infant ALs, 16 of 24 (66%) cases of de novo ALs, and 0 of 5 cases of therapy-related (TR) ALs. Conversely, ALL1 breakpoints in region B were detected in 20 of 28 (71.5%) cases of infant AL, 8 of 24 (33%) cases of de novo AL, and 5 of 5 (100%) cases of TR AL (P = 0.002). These results were confirmed by direct sequencing of the ALL1/AF4 fusion transcript in 30 cases (19 infants and 11 child and adult de novo cases). The analysis of ALL1/AF4 junction types showed that children and adults with de novo leukemia had ALL1 breakpoints in intron 6 (9 cases) or intron 7 (2 cases), whereas breakpoints in infant cases were mainly located in intron 8 (14 cases) and less frequently in intron 6 (4 cases) and intron 7 (1 case). The difference in ALL1 breakpoint location between infant and noninfant AL patients with ALL1/AF4 fusion was statistically significant (P = 0.00005). These data demonstrated that infant and TR ALs share a similar biased clustering of ALL1 gene breakpoints, which supports the possibility that topo II inhibitors may also operate in utero and play a crucial role in the etiology of infant leukemia.

Occurrence and metabolism of anandamide and related acyl-ethanolamides in ovaries of the sea urchin Paracentrotus lividus

Cannabinoid receptors have been described in sea urchin sperm and shown to mediate inhibition of sperm acrosome reaction. Anandamide (arachidonoyl-ethanolamide), the mammalian physiological ligand at the cannabinoid CB1 receptor, has been subsequently found to effect this inhibition. Here we present data showing that ovaries from the sea urchin Paracentrotus lividus contain anandamide and two related acyl-ethanolamides, as well as enzymatic activities potentially responsible for their biosynthesis and degradation. Pilot experiments carried out with either ovaries or spermatozoa, extracted from both P. lividus and Arbacea lixula and radiolabelled with [14C]ethanolamine, showed that in sexually mature ovaries of both species significant levels of radioactivity were incorporated into a lipid component with the same chromatographic behaviour as anandamide. Lipid extracts from P. lividus ovaries were purified and analysed by gas chromatography/mass spectrometry which showed the presence of low but measurable amounts of anandamide, palmitoyl- and stearoyl-ethanolamides. The extracts were also found to contain lipid components with the same chromatographic behaviour as the N-acyl-phosphatidyl-ethanolamines, the phospholipid precursors of acyl-ethanolamides in mammalian tissues, and capable of releasing anandamide, palmitoyl- and stearoyl-ethanolamides upon digestion with S. chromofuscus phospholipase D. Accordingly, whole homogenates from P. lividus contained an enzymatic activity capable of converting synthetic [3H]N-arachidonoyl-phosphatidyl-ethanolamine into [3H]anandamide. Finally, mature ovaries of P. lividus were shown also to contain an amidohydrolase activity which catalyses the hydrolysis of anandamide and palmitoyl-ethanolamide to ethanolamine. This enzyme displayed subcellular distribution, pH/temperature dependency profiles and sensitivity to inhibitors similar but not identical to those of the previously described 'anandamide amidohydrolase' from mammalian tissues. These data support the hypothesis, formulated in previous studies, that anandamide or related metabolites may be oocyte-derived cannabimimetic regulators of sea urchin fertility.

Sequential molecular monitoring of chimerism in chronic myeloid leukemia patients receiving donor lymphocyte transfusion for relapse after bone marrow transplantation

Recent observations of chimerism in patients relapsed following an allotransplant suggest the persistence of immunotolerance, thus offering a biologic rationale for the use of donor lymphocyte transfusion (DLT). In this study, we have analyzed by PCR amplification of several VNTR regions, sequential bone marrow and peripheral blood DNA samples in four patients who received DLT for CML relapse after bone marrow transplantation. Prior to DLT, all patients showed mixed chimerism in peripheral blood cells while two had mixed chimerism and two no chimerism in the BM. None of these four patients showed evidence of chimerism at the cytogenetic level (all had 100% +ve metaphases). After DLT, a complete hematologic and molecular remission (ie disappearance of the BCR/ABL fusion transcript) was obtained in the two patients who had bone marrow mixed chimerism prior to DLT. The two patients without evidence of marrow chimerism prior to DLT converted to a pattern of mixed chimerism after DLT, but both developed a severe bone marrow aplasia occurring at day 56 and 36, respectively. With regard to the sequential analysis of bone marrow chimerism after DLT we observed that: (1) the disappearance of BCR/ABL +ve cells paralleled the conversion to a pattern of full donor chimerism; and (2) the time interval to achieve CR was inversely correlated with the percentage of donor DNA in bone marrow. In conclusion, we have shown here that the assessment of bone marrow pre-DLT chimerism by PCR analysis might predict the response in patients with favorable characteristics, and also might identify patients at high risk of developing severe myelosuppression.

Multigenetic lesions in infant acute leukaemias: correlations with ALL-1 gene status

In this study we investigated the presence of structural lesions in the ALL-1, p53 and p16 (cyclin-dependent kinase 4 inhibitor) genes in leukaemic cells obtained from 22 patients with infant acute leukaemia (aged < 18 months). Of these, 18 cases were classified as acute lymphoblastic leukaemia (ALL) and four as acute myeloid leukaemia (AML). Tumour DNAs were analysed by a combination of Southern blot. polymerase chain reaction (PCR), single-strand conformation polymorphism (SSCP), and direct sequence analyses. The results showed ALL-1 gene rearrangements in 15/22 (68%) cases, p53 gene mutations in 5/22 (26%), and a homozygous deletion of p16 in a single T-ALL case. p53 and p16 alterations were all found in the group of patients with ALL-1 gene rearrangements. p53 mutations were more often associated with a myeloid phenotype (3/5). In summary, multiple molecular alterations were found in 6/15 (40%) infant acute leukaemias with ALL-1 rearrangements. As to the clinical course, patients with additional lesions had similar clinical outcome with respect to patients with ALL-1 gene rearrangement as the sole genetic aberration. This may support the hypothesis that ALL-1 alterations are genetic events per se sufficient to confer a fully malignant phenotype to the leukaemic clone.

Coriacenins: A New Class of Long Alkyl Chain Amino Alcohols from the Mediterranean Sponge Clathrina coriacea

The Mediterranean sponge Clathrina coriacea contains a series of long chain amino alcohols, named coriacenins (2-6), belonging to a new class of alkaloids. The structures of the novel compounds were elucidated by studying, with a combination of spectral and chemical methods, their peracetyl derivatives (2a-6a). Coriacenins are characterized by a bis(1,3-diamino-2-propanol) moiety and a linear alkyl chain varying both by length and by degree of unsaturation. The biosynthetic pathway leading to coriacenins seems to be unprecedented. It should, however, occur through condensation of an acetogenin with an uncommon amino acid.

Novel diterpenoid diacylglycerols from marine molluscs: potent morphogens and protein kinase C activators

Five novel 1,2-sn-diacylglycerols with diterpenoid acyl moieties in the sn-1 position were isolated and characterized, together with the corresponding 1,3-sn-diacylglycerols, from three species of dorid nudibranchs molluscs. Their potent activity as morphogens in vivo in the Hydra tentacle regeneration assay and their parallel activity as activators of rat brain protein kinase C (PKC) in vitro are reported here. Our findings promote the use of these compounds as useful molecular probes for both in vivo and in vitro studies on the participation of PKC in cell development.

Inflammatory pseudotumour of the liver with malignant transformation. Report of two cases

Inflammatory pseudotumour is a rare pathologic lesion, of unknown aetiology, rarely involving the liver. Resection seems to be the treatment of choice and it is generally associated with a good prognosis. Histologically, these processes appear to be benign, nevertheless, aggressive courses or recurrences of inflammatory pseudotumour with tumor-like deaths have been reported. The cases of two patients are described who underwent hepatic lobectomy for a liver mass that was diagnosed as liver inflammatory pseudotumour at the initial histopathological assessment: albeit a malignant course followed and both the patients died cachectic. One patient, a 39-year-old man, had an unusually aggressive clinical course and recurrence of the disease with multiple hepatic masses and extension into the thorax six years later. In the other case, in a 28-year-old woman, the hepatic lesion was identified as a low-grade hepatic sarcoma only seven years after surgery.

Precipitating Pseudomonas aeruginosa antibodies and antimicrobial therapy in cystic fibrosis patients

Forty patients with cystic fibrosis were studied bacteriologically and serologically. Precipitating Pseudomonas aeruginosa antibodies were monitored by crossed-immunoelectrophoresis (CIE) in order to evaluate the possibility of preventing chronic colonization by Pseudomonas aeruginosa by cycles of antimicrobial therapy. Sputum or pharyngeal aspirate and serum samples from all patients were analyzed by means of spread on selective media and CIE, respectively. Significant differences in the number of precipitins were obtained: noncolonized and intermittently colonized patients had no precipitins, whereas the number of precipitins in the chronically colonized patients varied from 11 to 44. An increase in the number of precipitins could be a good marker for initiation of therapy with antimicrobial agents that are either active against Pseudomonas aeruginosa or able to inhibit the release of virulence factors.

Clinical relevance of residual disease monitoring by polymerase chain reaction in patients with ALL-1/AF-4 positive-acute lymphoblastic leukaemia

In this study we used reverse transcriptase-polymerase chain reaction (RT-PCR) for the longitudinal monitoring of minimal residual disease in 12 patients with All-1/AF-4 positive ALL. Of these, seven also showed at presentation a typical t(4;11) cytogenetic translocation. Seven patients were infants <18 months of age and five were adults. Eleven patients were treated with high-dose intensive induction and consolidation chemotherapy without bone marrow transplantation and one received conservative treatment due to poor performance status. Three had resistant disease, four relapsed within 12 months after achieving complete remission, and five are in continuous complete remission (CCR) at 32, 39, 52, 53 and 61 months from diagnosis, respectively. The sequential analysis of the ALL-1/AF-4 hybrid transcript showed a persistently negative RT-PCR in the five CCR long-term survivors. The PCR analysis resulted persistently positive in the remaining seven cases, including the four cases who relapsed after the achievement of clinical CR. These data emphasize the clinical relevance of PCR monitoring analysis in t(4;11) ALL patients and should be considered in order to better determine variable post-remission treatment according to risk prediction.

Distribution of TP53 mutations among acute leukemias with MLL rearrangements

Acute leukemias carrying MLL rearrangements are characterized by a high degree of clinical and immunologic heterogeneity, as demonstrated by variability in their immunophenotype, consistent with lymphoid or myeloid/monoblastic derivation, as well as their occurrence in distinct age groups from infancy to adulthood. Recently, it was shown that inactivation of the TP53 tumor suppressor gene occurs frequently in cases of acute lymphoblastic leukemia carrying MLL rearrangements. In order to assess the extent of TP53 inactivation throughout the immunophenotypic and clinical spectrum of MLL+ acute leukemias, we tested for TP53 mutations 29 cases of MLL+ acute leukemias displaying lymphoid (13 cases) or myeloid/monoblastic (16 cases) features and belonging to different age groups. Mutations were detected in 6/16 myeloid/monoblastic cases and in 3/13 lymphoid cases. Among myeloid/monoblastic leukemias, the TP53 mutations occurred in 3/4 infants, but only in 3/16 cases in other age groups. Overall, our data suggest that (1) TP53 inactivation is a relatively common event in leukemias with MLL rearrangements irrespective of the leukemic phenotype and of the patients' age; (2) at least two genetic lesions (i.e., MLL rearrangement and TP53 mutation) have accumulated in the short time (few weeks after the birth or conception of the child) corresponding to the development of acute leukemias of infancy.

Therapy-related acute myelomonocytic leukemia following successful treatment for acute promyelocytic leukemia

We report a case of therapy-related acute myeloid leukemia (t-AML), M4 FAB subtype, with t(10;11)(p14;q21) chromosome abnormality developed in a patient treated for acute promyelocytic leukemia (APL) after 4 years of continuous complete remission (CCR). Two distinct forms of t-AML have been described: the classical type and the second type. Our case has many characteristics in common with the second type of t-AML such as: exposure to topoisomerase II active agents (idarubicin (IDA), mitoxantrone (MITOX), etoposide (VP16)), M4 FAB subtype, a latency period of 39 months and absence of a preleukemic phase. However, it differs in the chromosome 11 breakpoint (band q21 instead of q23) and absence of ALL-1 (Hrx, MLL, Htrx) gene involvement. This can represent the second observation of t-AML occurring after treatment for APL.

Acute leukemia presenting a variant Ph chromosome with p190 expression, dup 3q and -7, developed after malignant lymphoma treated with alkylating agents and topoisomerase II inhibitors

We describe the occurrence of a variant Ph chromosome (v-Ph) in a therapy-related acute leukemia (s-AL), developed after 8-year treatment for a NHL with alkylating agents, anthracyclines and topoisomerase II inhibitors. The v-Ph originated from a complex t(2;9;22) translocation, expressed a p190bcr-abl fusion protein, and was associated to other specific changes, such as dup(3) (q21q26) and -7. The s-AL, apparently not preceded by a dysplastic phase, presented with signs of trilineage dysplasia with 10% micromegakaryocytes; it was classified as M5 according to FAB. The complex genetic changes observed in the present case may reflect distinct leukemogenic effects by different chemotherapeutic agents.

Analysis of the BCL-6 gene configuration in diffuse B-cell non-Hodgkin's lymphomas and Hodgkin's disease

BCL-6 is a novel proto-oncogene that codes for a zinc-finger protein sharing homologies with many transcription factors. It has recently been shown that BCL-6 is involved in chromosome band 3q27 aberrations in non-Hodgkin's lymphomas (NHLs) and BCL-6 rearrangements have been detected in 34-45 per cent of diffuse large cell lymphomas with B immunophenotype. We have studied the BCL-6 gene configuration by Southern blot analysis in 60 cases of B-cell NHL and in 17 cases of Hodgkin's disease (HD). BCL-6 was rearranged in 15/46 (32.6 per cent) diffuse B-large cell lymphomas, mainly with centroblastic morphology, and in 2/11 (18.2 per cent) follicular (centroblastic-centrocytic) lymphomas. Conversely, all cases of HD, including four cases of lymphocyte predominant, nodular type (nodular paragranuloma), had a germline configuration. These findings confirm that BCL-6 is rearranged in a significant percentage of diffuse B-large cell lymphomas, suggesting that this proto-oncogene might have a pathogenetic role in this subset of NHLs, but our preliminary analysis suggests that BCL-6 lesions are not involved in the pathogenesis of HD. However, further investigations using more sensitive techniques are required to confirm these findings.

p53 gene inactivation in acute lymphoblastic leukemia of B cell lineage associates with chromosomal breakpoints at 11q23 and 8q24

The clinical heterogeneity of acute lymphoblastic leukemia (ALL) of B cell lineage reflects the presence of distinct molecular pathways leading to well-defined ALL molecular subtypes. These molecular pathways include the formation of the fusion transcripts BCR/ABL and E2A/PBX1, due to t(9;22) and t(1;19), respectively, as well as rearrangements of the MLL gene at 11q23 and of c-MYC at 8q24. Hyperdiploid ALL in the absence of chromosomal structural abnormalities is an additional ALL molecular subtype. Mutations of the RAS family genes and of the p53 tumor suppressor gene represent additional genetic lesions detected in a fraction (10-20%) of ALL cases. RAS activation in ALL may be detected in all molecular subtypes of ALL and denotes poor prognosis. Conversely, little is known regarding the clinical and biological features of ALL cases carrying p53 mutations. In order to help clarify the role of p53 inactivation in ALL development, we have determined the frequency of p53 mutations throughout the molecular spectrum of B cell lineage ALL. We report that p53 inactivation in ALL of B cell lineage is restricted to cases carrying a rearrangement of MLL or c-MYC, whereas it is consistently negative in other molecular subgroups. These data underline the molecular heterogeneity of ALL of B cell lineage and indicate that at least some of the molecular pathways involved in ALL pathogenesis require more than one genetic lesion.

Detection of homozygous deletions of the cyclin-dependent kinase 4 inhibitor (p16) gene in acute lymphoblastic leukemia and association with adverse prognostic features

A recently described putative tumor suppressor gene, the cyclin-dependent kinase 4 inhibitor (p16), has been shown to be altered by deletions and/or point mutations in various human cancers. To assess the incidence and clinico-biologic correlations of p16 homozygous deletion in hemopoietic tumors, we studied a panel of 244 DNA samples representative of distinct acute (99 cases) and chronic (57 cases) leukemia subtypes, myelodysplastic (22 cases) and myeloproliferative (15 cases) syndromes, and lymphomas (51 cases). A 361-bp probe complementary to the p16 exon 2 gene sequences was generated by polymerase chain reaction and used in Southern blot hybridization against these tumor DNAs. Homozygous deletions of p16 (p16-/-) were detected in 10 of 58 (17%) cases of acute lymphoblastic leukemia (ALL) of either B or T lineage and in no other tumors. Single-strand conformation polymorphism analysis of p16 exons 1 and 2 was also performed in 40 of the 58 ALL cases and in 16 lymphomas. In no cases were point mutations detected. The comparison of clinical features at presentation in p16-/- and in p16 germline ALL cases showed a greater leukemic cell mass (P = .001) and higher white blood cell counts (P = .01) in the former group. Two ALL cases in which diagnostic and relapse DNA samples were available showed p16-/- in both specimens. We conclude that homozygous p16 gene deletions characterize a subset of ALL with features of aggressive disease.

ALL-1 gene rearrangements in acute myeloid leukemia: association with M4-M5 French-American-British classification subtypes and young age

We have analyzed by Southern blotting the ALL-1 (MLL, HRX, Hrtx 1) gene configuration in a series of 126 patients with acute myeloid leukemia (AML) representative of all ages and French-American-British Classification groups and correlated this genetic feature with clinical and biological features at diagnosis. ALL-1 gene rearrangements were detected in 17 of the 74 cases with M4-M5 (myelomonocytic and monocytic) AML and in 2 of the 52 cases with other leukemic subtypes (P < 0.01). Within the series of 74 M4-M5 patients, ALL-1 rearrangements were significantly associated with French-American-British Classification M5 (P = 0.009), high WBC (P = 0.002), and young age. In particular, all 5 infant (< 1.5 years) AML cases, 6 of the 19 (31%) patients between 1.5 and 18 years of age, and 6 of the 50 (12%) patients > 18 years old showed an altered ALL-1 genomic configuration (P < 0.001). Immunophenotypic characterization revealed coexpression of lymphoid and myeloid markers in 6 of 17 ALL-1 rearranged M4-M5 cases. The IgH gene configuration was studied in 77 of 126 AMLs. Five patients (6%) showed IgH clonal rearrangements and all were in the ALL-1 rearranged group (P < 0.0001). Our findings indicate that ALL-1 rearrangement is the commonest genetic alteration presently detectable in M4-M5 AML, particularly in childhood where it is found in up to one-third of all cases. The association of IgH rearrangements with ALL-1 alterations in AML, coupled to the frequent detection in this subset of lymphoid associated markers, further supports the origin of these tumors from a common multipotent precursor with bipotential lymphoid and monocytic differentiation capability.

[Primary microcytoma of the larynx. Case report, ultrastructural study and review of the literature]

Oat cell carcinoma of the larynx is a rare tumor. A throughout search of the literature revealed only 80 cases; the first case in literature was reported by Olofsson in 1972. The tumor often presents in the sixth and seventh decades of life and appears to be highly aggressive and metastases develop early. We have had the opportunity to study ultrastructurally a small cell carcinoma of oat cell type arising in the larynx.

[Morphologic and ultrastructural changes of soft palate in patients who underwent palatopharyngoplasty]

In order to clarify pathogenesis of Obstructive Sleep Apnea Syndrome (OSAS) in patients with anatomic abnormalities of upper airways, we studied soft palate and uvula of OSAS patients by means of histological and ultrastructural techniques. 38 OSAS patients, severe and moderately severe form, underwent modified Palatopharingoplasty. We evaluated only 16 OSAS patients' soft palate and uvula and observed histological changes in all of them: submucosal edema and minor salivary glandes ipertrophy and iperplasy are present. On the contrary, ultramicroscope showed normal muscle fibers. Strie Z alterations and sarcomeres disorganization, although present, have no statistical value. Very probably, ronflement and apneas determined the observed alterations through trauma on pharingeal wall. Therefore, they are not OSAS primary cause.

Severe case of Al Awadi/Raas-Rothschild syndrome or new, possibly autosomal recessive facio-skeleto-genital syndrome

A Sicilian girl whose parents were first cousins had a severe tetramelic limb deficiency (amelia of lower limbs, peromelia of upper limbs) and other defects including cleft lip and palate, facial anomalies, athelia, low umbilicus, bladder exstrophy, no external genitalia, and anteriorly displaced anus. This probably represents a particularly severe case of Al Awadi/Raas-Rothschild syndrome (limb/pelvis-hypoplasia/aplasia syndrome, LPHAS), but the possibility of a new autosomal recessive facio-skeleto-genital syndrome cannot be excluded.

Prognostic relevance of ALL-1 gene rearrangement in infant acute leukemias

We and others have recently reported a high frequency (70-80%) of ALL-1 (MLL, HRX, HTRX) gene rearrangements in infants with acute leukemias (AL) aged less than 1 year. Preliminary observations in limited series also suggested that ALL-1 gene configuration is an important prognostic factor in this leukemic subset. We have now extended our study to a series of 45 AL patients aged between 0 and 18 months. The genomic configuration of ALL-1 in leukemic DNAs was determined by Southern blot hybridization and correlated with biological and clinical features at presentation, as well as with treatment outcome. Twenty-nine out of 45 (64%) patients showed ALL-1 rearrangements, including 4/11 (36%) infants aged between 13 and 18 months. Considering morphological types, 24/38 cases with acute lymphoblastic leukemia and 5/7 patients with acute myeloid leukemia showed ALL-1 rearrangements. The features more frequently found in association with ALL-1 rearrangements were hyperleukocytosis (P < 0.007) and CD19+/CD10- blast immunophenotype (P < 0.02). ALL-1 status was an independent prognostic marker of event-free survival (EFS) in a multivariate model including age, sex and WBC count, and maintained its statistical significance when FAB morphology was considered in the analysis by including AML patients. Considering the ALL cases the actuarial EFS was 57 and 9% for infants with germline and rearranged ALL-1 configuration, respectively (P = 0.008). A high frequency of ALL-1 gene alterations in infant AL is confirmed by this study. In addition, our results emphasize the need for extending the analysis of ALL-1 gene status to infants with AL aged > 12 months. We show that this genetic lesion is the most important variable negatively affecting prognosis in a multivariate model including other known risk factors. This latter observation should influence the choice of risk-adapted treatment strategies in this AL subset.

Formation and inactivation of endogenous cannabinoid anandamide in central neurons

Anandamide (N-arachidonoyl-ethanolamine) was recently identified as a brain arachidonate derivative that binds to and activates cannabinoid receptors, yet the mechanisms underlying formation, release and inactivation of this putative messenger molecule are still unclear. Here we report that anandamide is produced in and released from cultured brain neurons in a calcium ion-dependent manner when the neurons are stimulated with membrane-depolarizing agents. Anandamide formation occurs through phosphodiesterase-mediated cleavage of a novel phospholipid precursor, N-arachidonoyl-phosphatidylethanolamine. A similar mechanism also governs the formation of a family of anandamide congeners, whose possible roles in neuronal signalling remain unknown. Our results and those of others indicate therefore that multiple biochemical pathways may participate in anandamide formation in brain tissue. The life span of extracellular anandamide is limited by a rapid and selective process of cellular uptake, which is accompanied by hydrolytic degradation to ethanolamine and arachidonate. Our results thus strongly support the proposed role of anandamide as an endogenous neuronal messenger.