Geochemical behaviour of rare earths in Vitis vinifera grafted onto different rootstocks and growing on several soils.

The geochemical behaviour of lanthanides and yttrium (Rare Earth Elements, REEs) has been investigated mainly in geological systems where these elements represent the best proxies of processes involving the occurrence of an interface between different media. This behaviour is assessed according to features recorded in sequences of REE concentrations along the REE series normalised with respect to a reference material. In this study, the geochemical behaviour of REE was investigated in different parts of Vitis vinifera specimens grown off-soil, on soils of different nature and grafted onto several rootstocks in order to evaluate effects induced by these changes. The results indicated that roots are the plant organs where REEs are preferentially concentrated, in particular elements from Sm to Ho (middle REE, MREE) whereas Eu enrichments occur in aerial parts. The geochemical behaviour of REE suggests that MREE enrichments in roots are due to preferential MREE interactions with biological membranes or to surface complexation with newly formed phosphates. Eu-positive anomalies suggest that Eu(3+) can form stable organic complexes in place of Ca(2+) in several biological processes in xylem fluids. The possibility that Eu mobility in these fluids can be enhanced by its reductive speciation as Eu(2+) cannot be ruled out. The assessment of the geochemical behaviour of REE according to the theory of the Tetrad Effect carried out confirms that REEs coming from soil are scavenged onto root tissues or mineral surfaces whereas their behaviour in aerial parts of V. vinifera is driven by dissolved complexation.

Enrichment in c-Kit+ enhances mesodermal and neural differentiation of human chorionic placental cells.

OBJECTIVE: Human term placenta (HTP) has attracted increasing attention as an alternative source of stem cells for regenerative medicine since the amniochorionic membrane harbors stem cells populations that are easily accessible, abundantly available without ethical objections. In the chorionic side of HTP we found a progenitor perivascular "niche" in which rare cells co-express Oct-4 and c-Kit. We investigated the stem cell characteristics and differentiation potential of a chorionic derived population enriched in c-Kit(+) cells and compared this to the unenriched population. STUDY DESIGN: Cells, isolated from the chorion of HTP, were expanded and enriched in c-Kit(+) cells (Chorionic Stem Cells-CSC). Histological staining, immunofluorescence, Western blot and flow cytometry were used to verify the stem cells characteristics of the populations and to compare the differentiation capability towards mesodermal and neural lineages in vitro. RESULTS: The expression of the pluripotent marker Oct-4 was greater in the CSCs compared to the unselected cells (Chorionic Cell-CC) but both Oct-4 and c-Kit expression decreased during passages. After differentiation, CSC displayed stronger chondrogenic and osteogenic potential and a greater adipogenic forming capacity compared to unselected ones. CSC differentiated better into immature oligodendrocytes while CC showed a neuronal progenitor differentiation potential. Moreover, both populations were able to differentiate in hepatogenic lineage. CONCLUSION: CSC display improved Oct-4 expression and a high differentiation potential into mesodermal lineages and oligodendrocytes.

Human dental pulp stem cells produce mineralized matrix in 2D and 3D cultures.

The aim of this study was to characterize the in vitro osteogenic differentiation of dental pulp stem cells (DPSCs) in 2D cultures and 3D biomaterials. DPSCs, separated from dental pulp by enzymatic digestion, and isolated by magnetic cell sorting were differentiated toward osteogenic lineage on 2D surface by using an osteogenic medium. During the differentiation process, DPSCs express specific bone proteins like Runx-2, Osx, OPN and OCN with a sequential expression, analogous to those occurring during osteoblast differentiation, and produce extracellular calcium deposits. In order to differentiate cells in a 3D space that mimes the physiological environment, DPSCs were cultured in two distinct bioscaffolds, Matrigel™ and Collagen sponge. With the addition of a third dimension, osteogenic differentiation and mineralized extracellular matrix production significantly improved. In particular, in Matrigel™ DPSCs differentiated with osteoblast/osteocyte characteristics and connected by gap junction, and therefore formed calcified nodules with a 3D intercellular network. Furthermore, DPSCs differentiated in collagen sponge actively secrete human type I collagen micro-fibrils and form calcified matrix containing trabecular-like structures. These neo-formed DPSCs-scaffold devices may be used in regenerative surgical applications in order to resolve pathologies and traumas characterized by critical size bone defects.

DNA sequence analysis proves Hb M-Milwaukee-2 is due to beta-globin gene codon 92 (CAC-->TAC), the presumed mutation of Hb M-Hyde Park and Hb M-Akita.

Among the causes of congenital methemoglobinemia, Hb M-Milwaukee-2 was one of the earliest described, in a patient who also had Hb E trait. The structure of Hb M-Milwaukee-2 has been elusive. DNA sequence analysis, as here reported, proves that this hemoglobin variant is due to the mutation CAC-->TAC at codon 92 of the beta-globin gene, corresponding to the substitution of tyrosine for histidine. This mutation is identical with that presumed to be the cause of Hb M-Hyde Park and Hb M-Akita. In addition, the DNA mutation of Hb E, GAG-->AAG at codon 26, was confirmed in this case.

Measurement of activin in biological fluids by radioimmunoassay, utilizing dissociating agents to remove the interference of follistatin.

Activin, a dimer of the beta-subunits of inhibin, is a member of the transforming growth factor beta (TGF-beta) superfamily of growth factors and has a widespread range of actions in a variety of tissues. The investigation of the physiology of activin action has been facilitated in recent years by the availability of immunoassays in addition to bioassays. Follistatin has been shown to bind to activin with a high affinity and therefore interferes in both radioimmunoassays and enzyme-linked immunosorbent assays (ELISAs). In this study we examined the effect of various surfactants and 1.4-dioxane on the measurement of activin in the presence of follistatin by radioimmunoassay. The addition of a combination of sodium deoxycholate. Tween 20 and sodium dodecyl sulphate removed the interference of follistatin in the radioimmunoassay. The measured content of activin in male rat serum, human male serum, human female serum and bovine follicular fluid rose from 3.29 to 4.15, < 0.48 to 2.87, 2.42 to 4.17 and 30.9 to 85.6 ng/ml, respectively, when assayed in the presence of the dissociating reagents. It was unclear whether the altered potencies were due to a dissociation of the follistatin/activin complex rather than the exposure of the epitope on activin recognized by the antiserum. Serum concentrations of activin were lower than those found in testicular cytosols, and after castration no change in serum activin levels was observed, suggesting that the testis does not contribute significantly to circulating activin levels. The use of the dissociating reagents in the radioimmunoassay will enable studies to be carried out that more accurately measure the activin content of various biological fluids, and thus lead to a greater understanding of the physiology of this growth factor.

51Cr release assay of clozapine-induced cytotoxicity: evidence for immunogenic mechanism.

Serum drawn from patients during clozapine-induced agranulocytosis was toxic to human polymorphonuclear leukocytes (PMNs). Toxicity was produced by an immunoglobulin fraction, predominantly of the IgM class. The offending drug was not necessary at this stage to produce cytotoxicity. These effects were observed by inhibiting post-phagocytosis glycolysis, by ejection of trypan blue, or by enhanced release of 51Cr from lysed-labeled PMNs. Direct chemical toxicity, produced by clozapine or its metabolites, was tested by similar procedures. At a concentration of 10(-5) M in a colloidal milieu produced by dilution with AB serum, no cytotoxicity was observed; however, in aqueous medium. N-desmethylclozapine was toxic to PMNs and proliferating lymphocytes. Post-recovery serum appeared to be inert, but cytotoxicity was restored by adding clozapine or N-desmethylclozapine to the sensitive patient's serum. At this stage, cytotoxicity as measured by 51Cr release was abrogated by anti-IgG or anti-IgM. These relationships favor an immunologic mechanism that damages peripheral PMNs. Development of colony-forming units-granulocyte (CFU-G) was similarly inhibited in normal marrow cultures by cytotoxic serum alone, whereas no metabolite had such an effect at the same concentration (10(-5) M).

Agranulocytosis during antibiotic therapy: drug sensitivity or sepsis?

Forty-three patients reviewed from the literature and five cases of agranulocytosis during antibiotic therapy studied by the author are presented. Time required to develop agranulocytosis with antibiotics was < 19 days in comparison to > 40 days required with nonantibiotic drugs. In all, agranulocytosis occurred concomitantly with drug treatment and became normal as treatment was discontinued. Retrospective rechallenge studies suggest that agranulocytosis may be dose related. In all cases PMNs were almost completely deleted and marrows were devoid of granulocyte precursors. In contrast, leukopenia secondary to overwhelming sepsis displayed persisting granulocytes in peripheral blood and marrow. While leukagglutinins were not found in nine cited cases, four serums were toxic to test PMNs as measured by suppression of postphagocytosis respiratory burst. Clindamycin directly suppressed development of CFU-G in one sensitive patient but not in 16 normal controls. The hazard of antibiotics in suppressing granulocytopoiesis is emphasized by these observations.

Cytotoxic activity in serum of patients with clozapine-induced agranulocytosis.

Studies were conducted on serum samples collected from 15 patients during the course of clozapine-induced agranulocytosis. During acute phases of agranulocytosis, serum was cytotoxic to peripheral polymorphonuclear neutrophils (PMNs), as indicated by complement-dependent suppression of postphagocytosis respiratory burst and by increased retention of trypan blue dye by test PMNs. Cytotoxicity was removed by adsorption with allogeneic PMNs, was attenuated by antibody to immunoglobulin M but not by antibody to immunoglobulin G antigen-binding fragment, was not dialyzable, and was partially removed by 2-mercaptoethanol and dialysis. Three patients in a longitudinal study all had perturbed postphagocytosis respiratory burst 20 days before agranulocytosis developed. In all patients cytotoxicity disappeared less than 40 days after treatment when the offending drug was discontinued. Trypan blue dye reactivity was similar when tested. At 20% of culture medium, all serum samples partially suppressed development of colony-forming units of granulocytes and macrophages (CFU-GM) in marrow cultures. At 40% of culture medium, agranulocytosis serum suppressed CFU-GM completely but did not inhibit development of colony-forming units of erythroblasts (CFU-E) or burst-forming units of erythroblasts (BFU-E). Addition of clozapine alone or to agranulocytosis serum neither enhanced nor suppressed toxicity to peripheral PMNs. Neither clozapine nor its toxic metabolic end-products directly produced equivalent cytotoxicity to cellular function or proliferation at 10(-5)mol/L. Serum from patients given clozapine who did not have agranulocytosis and samples from allogeneic normal subjects were not cytotoxic to test PMNs. Cytotoxicity was specific to granulocyte cell lines because development of CFU-GM was inhibited by agranulocytosis serum, whereas CFU-E and BFU-E were not similarly affected. Further studies are in progress to distinguish between immunogenic and non-immunogenic mechanisms.

On the possible mechanisms and predictability of clozapine-induced agranulocytosis.

Studies were conducted on serum removed from 15 patients before, during, and after, clozapine-induced agranulocytosis. Cytotoxic studies were compared with samples taken from patients during treatment with clozapine who did not develop agranulocytosis or treatment controls (TC); additional controls consisted of allogeneic (NC) and autogeneic serum from apparently normal people. The effect of serum on measurable functions of polymorphonuclear neutrophils (PMNs) taken from normal people was tested. Procedures under study included suppression of post-phagocytosis-induced 14CO2-indicated respiratory burst, as well as ejection of trypan blue by test PMNs. PMNs exposed to active agranulocytosis serum plus complement displayed diminished 14CO2 emission during phagocytosis or failed to eject trypan blue. PMNs exposed to serum of TC and NC continued to function normally as regards 14CO2 emission and trypan blue ejection. Five patients studied before the development of agranulocytosis showed suppressed PMN function, which increased to peak value during agranulocytosis and then disappeared within 40 days of recovery. Similar suppression of colony forming units of granulocytes and macrophages (CFU-GM) was found whenever agranulocytosis serum was included in the marrow culture. The cytotoxic material required complement for its full expression, was not dialysable, was neutralised by anti-IgM serum, and was absorbed by test PMNs. Furthermore, solutions of clozapine or 5 of its metabolites offered no similar suppression of PMN function in vitro after incubation in an aqueous medium or with normal serum. These observations favour development of an immunogenic clone in sensitive people during active treatment with clozapine, which eventually leads to precipitous depletion of PMNs and their precursors. The early appearance of this suppressive substance may offer an early warning for development of agranulocytosis.

Drug-induced agranulocytosis. Peripheral destruction of polymorphonuclear leukocytes and their marrow precursors.

Drug-induced agranulocytosis is a highly individualized and unexpected reaction to specific drugs. It may be due to immunogenic or cytotoxic factors. Most instances are produced by a poorly understood immune response to immunogenic drugs. Others are associated with direct suppression of marrow committed stem cells by the direct action of the offending drug or its toxic metabolic end products. The early appearance of polymorphonuclear neutrophil (PMN) antibodies may offer an early warning to sensitized patients. Antibodies, if present, disappear shortly after the drug is discontinued. Agranulocytosis, due to direct action of the drug, is characterized by morphologic aplasia of marrow and is more likely to occur if the affected host has a concomitant defect in marrow cellular proliferation. Accumulation of toxic metabolic end products such as arene oxides may occur if the host is deficient in a microsomal system required to dispose of this material.

Clozapine-induced agranulocytosis: non-cross-reactivity with other psychotropic drugs.

Clozapine, an atypical neuroleptic with unique clinical and preclinical properties, represents a potentially valuable addition to the psychopharmacopeia. Its development and use have been limited by its higher frequency, compared with other pharmacologic treatments, of the potentially fatal side effect of agranulocytosis. This article describes the natural history of five cases of agranulocytosis that occurred in the course of clozapine treatment. The cases were generally uniform as to onset, recovery, and hematologic features. No patient had hematologic reactions to treatment with psychotropic agents before or after clozapine treatment. These findings, along with other work in progress, suggest that clozapine's granulocytoxic effects are produced by a highly specific immune-mediated mechanism.

Reclassification of leukemia among A-bomb survivors in Nagasaki using French-American-British (FAB) classification for acute leukemia.

The concordance rate for diagnoses of atomic bomb-related cases of leukemia in Nagasaki was determined using the French-American-British (FAB) classification for acute leukemias and myelodysplastic syndromes (MDS). Two Radiation Effects Research Foundation (RERF) hematologists and one of the members (JMB) of the FAB cooperative group reviewed independently the peripheral blood and/or bone marrow smears from 193 people with leukemia or a related disorder. There was 85% agreement in the identification of types and subtypes of acute leukemia. There was almost complete agreement for the diagnoses of non-FAB disorders (chronic myeloid leukemia (CML), adult T-cell leukemia (ATL) and others) resulting in overall concordance of 88.2%. The present study suggests that the previously established leukemia types for about a quarter of the cases of acute leukemia and related disorders except CML should be changed. Considerable numbers of cases of ATL and MDS were involved in this series. The frequency of the former disease was not high in the high-dose irradiated group, but that of the latter was considerably high. All subtypes of AML except M3 and M6 were present in the high-dose group. The striking difference in CML incidence between Nagasaki and Hiroshima may continue to be a problem in relation to biological response to radiation exposure.

Clinical presentation and natural history of patients with essential thrombocythemia and the Philadelphia chromosome.

Six women presented with the clinical picture of essential thrombocythemia (ET) without the anemia, marked splenomegaly, and extreme leukocytosis characteristic of chronic myelogenous leukemia (CML). All had the Philadelphia chromosome on karyotype analysis of the bone marrow. Peripheral basophilia was present in four cases, providing a clinical clue that the Philadelphia chromosome might be present. Marrow biopsy showed granulocytic hyperplasia and either small megakaryocytes or sheets of megakaryocytes with marked atypia, findings that are more typical of CML than ET. The clinical importance of finding the Philadelphia chromosome in patients who seem to have ET is in assessing prognosis. ET generally follows a chronic, indolent course. However, five of these six patients who had the Philadelphia chromosome underwent clinical transition to the accelerated phase of CML or blastic leukemia in 4-7 years.