Memory recall: New behavioral protocols for examining distinct forms of context specific recall in animals.

This study outlines two novel protocols for examining context specific recall in animals prior to embarking on neurobiological studies. The approach is distinct from and contrasts with studies investigating associative familiarity that depend upon procedural variations of the widely used novel object recognition task. It uses an event arena in which animals are trained across numerous sessions to search for, find and dig up reward from sandwells during sample and choice trials - a prominent spatial event for a rodent. The arena could be laid out as either of two highly distinct contexts with which the animals became fully familiar throughout training. In one protocol, the location of the correct sandwell in each context remained stable across days, whereas in the other, the correct digging location varied in a counterbalanced manner across each successive session. Thus, context-specific recall of the spatial location of successful digging during choice trials was either from a stable long-term memory or could reflect context specific spatial recency of the location where reward had been available that session. Both protocols revealed effective memory recall in choice and probe tests which, at the point of test, were procedurally identical in both cases.

Autologous stem cell transplantation: evaluation of erythropoietic reconstitution by highly fluorescent reticulocyte counts, erythropoietin, soluble transferrin receptors, ferritin, TIBC and iron dosages.

The plasma concentrations of erythropoietin (Ep), soluble transferrin receptors (sTfRs), iron, total iron binding capacity (TIBC) and ferritin were monitored in five leukaemia patients undergoing autologous bone marrow stem cell transplantation (BMSCT) and in 10 lymphoma and 21 ovarian cancer patients undergoing autologous peripheral blood SCT (PBSCT); 9/21 ovarian cancer patients received recombinant human G-CSF and Ep and six recombinant human GM-CSF and Ep following SCT. All parameters were evaluated in relation to the kinetics of erythroid reconstitution as evaluated by haemoglobin (Hb) and reticulocyte levels [including the fraction of immature reticulocytes, also called highly fluorescent reticulocytes (HFR)]. Leukaemia patients undergoing BMSCT showed only a delayed (occurring at days 35-50 after SCT) and partial RBC, neutrophil and platelet recovery, whereas all patients undergoing PBSCT exhibited a rapid (occurring at days 10-15 after SCT) and sustained haemopoietic recovery. The various levels of erythroid rescue observed among these patients markedly influenced the kinetics of the different parameters investigated: (i) in leukaemia BMSCT patients sTfRs declined following SCT and remained at low levels thereafter, whereas Ep, iron. TIBC and ferritin showed a progressive and significant increase; (ii) in the different groups of patients undergoing PBSCT: (a) sTfR levels first declined following SCT and then returned to pre-therapy values at days 12-16, this response preceded erythropoietic recovery; (b) Ep, total iron, TIBC and ferritin showed an initial increase in the first days following SCT and then returned to pre-therapy values. Altogether, these observations indicate that: (i) both sTfR levels and reticulocyte counts are predictive parameters of erythropoietic recovery; (ii) coordinated changes of biochemical parameters underlying iron metabolism (iron, TIBC and ferritin) accompany erythroid rescue following SCT.

Combined vitamin D3/retinoic acid induction of human promyelocytic cell lines: enhanced phagocytic cell maturation and hybrid granulomonocytic phenotype.

Studies on the effect of retinoic acid (RA) and 1,25-dihydroxyvitamin (D3) on the differentiation of leukemic cells have provided insight into the cellular and molecular mechanisms underlying hematopoietic cell differentiation. We have evaluated the combined effect of these chemical inducers on the differentiation of HL-60 and AML-193 promyelocytic leukemia cell lines. Simultaneous RA+D3 addition potentiated leukemic cell maturation up to mature phagocytic cells. Interestingly, AML-193 cells induced with D3 and RA displayed a typical neutrophilic morphology while exhibiting properties specific to monocytic cells, e.g., high expression of CD14 membrane antigen, capacity to bind bacterial lipopolysaccharide, and monocytic-specific esterase activity; this hybrid granulomonocytic (GM) phenotype was not observed upon initial incubation with one inducer and later addition of the other. Parallel control studies were performed with purified normal GM progenitors, triggered by interleukin 3+GM-colony-stimulating factor (CSF) in FCS-rich or -free clonogenic culture, by GM-CSF+M-CSF in FCS-rich clonogenic culture, and by M-CSF in liquid suspension culture. The progenitors grown in the first condition generate exclusively G clones, even upon addition of D3 and/or RA. The progenitors grown in the second and third culture conditions generate either G and M clones (second culture condition) or a population of cells composed by a majority of monocytes (third culture condition); the D3 addition did not modify this differentiation pattern, whereas RA or RA+D3 addition elicited a marked inhibition of monocytic differentiation. These observations suggest that the development of a hybrid GM phenotype is restricted to the progeny of bipotent GM leukemic precursors.

HOXB gene expression and function in differentiating purified hematopoietic progenitors.

Intensive efforts have led to the development of methods for stringent purification of adult hematopoietic progenitor cells (HPCs), particularly from peripheral blood (PB). The purification procedure previously reported by our group (Science, 1990) provided a high HPC frequency, but yielded a low HPC recovery (< or = 5-10%). We therefore developed an improved purification methodology based on "potentiated" negative immunobead selection (Step IIIP) by addition of anti-CD45, -11a and -71 monoclonal antibodies (mAbs) to the previously utilized panel of mAbs. This simplified procedure consistently allows not only high level purification but also abundant recovery of early HPCs: the final Step IIIP cell population (0.95 x 10(6) cells/4 PB donors, mean value) features an 81% HPC frequency and a recovery of 45% of the initial HPCs. The purified HPCs bear the primitive HPC phenotype, i.e., they are consistently CD34+, largely CD33-/45RA-, and in part HLA-DR-/low/CD38-/low/Thy-1+. In optimized semi-solid culture, the purified erythroid/multipotent HPCs give rise to macroscopic colonies (10,000-150,000 cells/clone, > 0.5 mm size colonies). This purification methodology compares favorably with previously reported procedures in terms of combined HPC frequency and recovery: availability of a large number of highly purified, early HPCs will provide an experimental tool for analysis of the molecular/cellular basis of early hematopoiesis. We have investigated by reverse transcription-polymerase chain reaction (RT-PCR) the mRNA expression of homeobox B (HOXB) cluster genes in purified HPCs induced in liquid suspension culture to gradual erythroid or granulopoietic (largely eosinophilic) differentiation and maturation by differential growth factor (GF) stimulus. Only B3 is expressed in quiescent HPCs. After GF treatment B3 expression is enhanced in the initial 24 h and then through erythroid and granulopoietic differentiation and maturation. HOXB4 and B5 are induced at slightly later times and expressed through maturation in both lineages, while B6 is selectively induced in granulocytic differentiation. B2 is transiently expressed at low level in the granulopoietic pathway, while it is detected only in advanced stages of erythropoiesis; B7, B8 and B9 are essentially not detected. Functional studies were performed with antisense phosphorothioate oligomers to HOX mRNAs including: 1) anti-B3 oligomer (alpha-B3) treatment of purified HPCs induces a striking blockade of both erythroid and granulomonocytic colony formation, 2) alpha-B6 selectively and markedly inhibits granulomonocytic colony formation, 3) alpha-B4 and alpha-B5 cause a significant, less pronounced decrease of both colony types and finally, 4) alpha-B2 and alpha-B7, alpha-B9 exert little and no effect respectively.

Cellular and molecular studies on the early stages of human hematopoietic differentiation in culture of pure progenitors.

Methodology has been developed that enables virtually complete purification and recovery of early hematopoietic progenitors from human adult blood, a minority of which is multipotent and endowed with self-renewal capacities, i.e., exhibits stem cell properties. This report briefly reviews: (i) the key steps involved in the progenitor purification and assay procedure; (ii) the characterization of "pure" progenitors at the level of membrane antigen pattern and response to HGFs; (iii) the development of a liquid suspension culture for the pure progenitors, which allows synchronized and selective erythroid or GM differentiation, and hence may be utilized for the analysis of molecular mechanisms underlying early and late stages of hematopoiesis; (iv) the study of the expression and modulation of HGFRs expressed on progenitors.

[Therapy of urinary tract infections. Clinical experience comparing norfloxacin to other quinolones]. / Terapia delle infezioni del tratto urinario. Esperienza clinica di confronto tra la norfloxacina ed altri chinolonici.

The paper examines to treatment of 40 cases of urinary infections and compares the efficacy of pipemidic acid, norfloxacin, cinoxacin and ofloxacin. All these compounds demonstrated a good level of therapeutic efficacy, both in terms of management and effectiveness; in particular, norfloxacin and ofloxacin were preferable to the other compounds since they caused fewer side-effects.

Adoptive immunotherapy of human cancer: the cytokine cascade and monocyte activation following high-dose interleukin 2 bolus treatment.

Serum concentration kinetics of gamma-interferon (IFN-gamma), neopterin, 2'-5' A synthetase and tumor necrosis factor alpha were determined in five cancer patients undergoing adoptive immunotherapy with high-dose interleukin 2 (IL-2) bolus infusion and lymphokine-activated killer cells according to the National Cancer Institute, NIH protocol. In all cases a significant increase of these markers was observed after IL-2 treatment. This suggests that the antitumor effect of high-dose IL-2 bolus administration may be in part mediated by activation of a cascade of endogenous cytokines including IFN-gamma and tumor necrosis factor alpha. After IL-2 bolus injection, the kinetics of neopterin was similar but delayed when compared to that of IFN-gamma: this suggests that macrophages, the specific source of neopterin, become activated by IFN-gamma following IL-2-mediated lymphocyte induction, thus implying a possible role for macrophages in the antitumor effects mediated by IL-2 and lymphokine-activated killer cells.

Constitutive expression and abnormal glycosylation of transferrin receptor in acute T-cell leukemia.

The expression of transferrin receptors (TrfRs) was investigated in acute T-cell leukemia (T-ALL) blasts at the molecular, biochemical, immunological, and functional level. TrfRs, although not detected on quiescent T-cells from normal adults, are constitutively expressed at high level on the blasts from all T-ALL patients and bind normally to transferrin. Their number is modulated by the intracellular iron level, but is independent of exogenous interleukin 2. They also exhibit immunological and biochemical abnormalities, in that: (a) they react preferentially with monoclonal antibodies (MAb) that recognize ligand-binding domains of TrfR (42/6 and 43/31), as compared to MAbs (B3/25, OKT9) that interact with the nonligand binding domains; (b) they have a reduced molecular weight, as compared to TrfR on normal thymocytes and activated T-lymphocytes: this phenomenon is apparently related to a defective glycosylation. It is noteworthy that expression of TrfR was not observed in a large series of other types of acute leukemias, i.e., pre-B, B, and myeloid leukemias, excluding erythroleukemias. The constitutive, high level expression of TrfRs on T-ALL blasts may play a key role in the stepwise progression of this malignancy and particularly provide a proliferative advantage to T-ALL blasts as compared to normal T-lymphocytes. Furthermore, indirect evidence suggests that the glycosylation defect of TrfR on T-ALL blasts contributes to their tumorigenic capacity.

Iron up-modulates the expression of transferrin receptors during monocyte-macrophage maturation.

We have investigated the effect of iron on the expression of transferrin receptors (TrfRs) and ferritin chains in cultures of human peripheral blood monocytes maturing to macrophages. Monocyte-macrophage maturation is associated with a gradual rise of Trf-binding capacity in the absence of cell proliferation. At all culture times, treatment with ferric ammonium citrate induces a dose-dependent rise of the Trf-binding level as compared with nontreated cells. Scatchard analysis revealed that this phenomenon is due to an increase in receptor number rather than an alteration in ligand-receptor affinity. Biosynthesis experiments indicated that the rise in number of TrfRs is due to an increase of receptor synthesis, which is associated with a sustained elevation of the TrfR RNA level. The up-regulation of TrfR synthesis is specific in that expression of other macrophage membrane proteins is not affected by iron addition. Conversely, addition of an iron chelator induced a slight decrease of TrfR synthesis. The expression of heavy and light ferritin chains at RNA and protein levels was markedly more elevated in cultured macrophages than in fresh monocytes, thus suggesting modulation of ferritin genes at transcriptional or post-transcriptional levels. Addition of iron salts to monocyte-macrophage cultures sharply stimulated ferritin synthesis but only slightly enhanced the level of ferritin RNA, thus indicating a modulation at the translational level. These results suggests that in cultured human monocytes-macrophages, iron up-regulates TrfR expression, thus in sharp contrast to the negative feedback reported in a variety of other cell types. These observations may shed light on the mechanism(s) of iron storage in tissue macrophages under normal conditions and possibly on the pathogenesis of diseases characterized by abnormal iron storage.

Plasma cortisol and testosterone in hypercholesterolaemia treated with clofibrate and lovastatin.

Plasma testosterone and cortisol concentrations were measured in 32 familial heterozygous hypercholesterolaemic subjects, aged 40-45 years. The subjects were divided into two groups of 16, each containing eight men and eight women. The women had normal menstrual cycles. After a period on placebo, one group of patients was given 40 mg/day lovastatin and the other was given 1500 mg/day clofibrate. Both drugs significantly reduced the plasma cholesterol concentration, however, unlike clofibrate, lovastatin did not decrease plasma levels of testosterone and cortisol. The response to stimulation by adrenocorticotrophic hormone of plasma cortisol and urinary 17-hydroxy levels was significantly reduced by treatment with clofibrate, but unchanged by lovastatin. The different effects produced by the two drugs probably reflect different mechanisms and sites of action.

Zinc modulates the mitogenic activation of human peripheral blood lymphocytes.

In the present study we have investigated the effect of Zn salts on the mitogenetic activation of human peripheral blood lymphocytes (PBL). Our results show that Zn2+ enhances the level of DNA synthesis in human T lymphocytes stimulated by a mitogenic lectin, phytohemagglutinin (PHA); this effect seems to be mediated through an enhanced expression of both interleukin-2 (IL-2) and transferrin (Trf) receptors. We have also analyzed the mitogenic effect of Zn2+ alone on PBL, in the absence of other mitogenic stimuli. In this regard we have identified large light density T lymphocytes as the PBL population which is activated to proliferate by Zn2+. Finally, we showed that Zn2+ stimulates natural killer (NK) activity; this effect is apparently not due to a direct action on NK lymphocytes, but is related to endogenous cytokines released by accessory cells which in turn stimulate the cytolytic activity of NK lymphocytes.

Unusual vascular malformation of the kidney in both twins of a monozygotic pair: short case report.

A case of double bilateral renal vessels in both twins of a MZ pair is reported for the first time. Even in non-twins, the anomalies reported so far involved the inferior polar arteries in agreement with the embryological development. The two male twins, examined at the age of 14 years, had simultaneously developed a marked hypertension at the age of 7 years. Zygosity was determined by blood group and HLA analysis and various clinical tests were carried out to diagnose the condition. It is suggested that the anomaly is the result of a genetically induced early block in embryonic development.

Bromodeoxyuridine treatment of normal adult erythroid colonies: an in vitro model for reactivation of human fetal globin genes.

We report that bromodeoxyuridine (BrdU) addition in semi-solid cultures of normal adult erythroid progenitors causes a sharp rise of gamma-globin gene expression in erythroid colonies. Control studies were carefully carried out to exclude the possibility of toxic effects exerted by the drug in these experimental conditions. In particular, BrdU addition induces a sharp increase in the level of relative gamma-globin synthesis and content in pooled BFU-E-derived colonies: this rise is clearly observed in single bursts of the mature type (largely composed of late erythroblasts) but not in immature ones (essentially comprising early erythroblasts). Furthermore, it is associated with an increase of the G gamma/G gamma + A gamma synthetic ratio from adult up to fetal like values. Reactivation of gamma-synthesis was observed even if BrdU was added to colonies composed essentially of early erythroblasts, ie, when BrdU was added to either bursts at day 10 of culture or late CFU-E-derived clones at day 1. These in vitro observations indicate modulation of gamma-synthesis at the stage of erythroblasts from normal adults. At the molecular level we suggest that BrdU, by replacing thymidine in DNA, may inhibit the switch from a fetal-like biosynthetic program expressed in early erythroblastic differentiation to the adult program expressed in later stages of maturation.

HLA antigens on human hemopoietic progenitors during embryonic-fetal life: expression and in vitro modulation.

We have analyzed the time course of the expression of HLA antigens on hemopoietic progenitors (BFU-E, CFU-E and CFU-GM) from human embryonic-fetal livers (FL). HLA ABC and Ia-like antigens are never detected on progenitor cells at 5-week post-conception. Their expression initiates at 6-week and progressively increases thereafter, up to near-adult levels at 9-week. The time course of HLA antigen expression on erythroid precursors, derived from FL at corresponding gestational ages, parallels that observed on hemopoietic progenitors. Incubation of embryonic progenitors or precursors with medium conditioned by PHA-stimulated adult peripheral blood mononucleated cells induces a marked increase of the expression of both HLA-ABC and Ia-like antigens. Conversely, incubation with recombinant gamma-interferon causes a marked increase of HLA-ABC, but not Ia-like antigen expression, thus in contrast with results observed on adult monocytes.