[Comparison between two different on-line dialytic techniques: Standard HFR vs post-dilutional HFR]. / Emodiafiltrazione con reinfusione di ultrafiltrato rigenerato in pre- e post-diluizione: due tecniche on-line a confronto.

PURPOSE: Among hemodiafiltration (HFD) techniques, hemodiafiltration reinfusion (HFR) seems unable to achieve an optimal depurative efficacy. This study aimed to evaluate whether the HFR technique as suggested in its original configuration could be improved by devising a new technique (post-dilution HFR (PDHFR)) inverting the purification sequence to increase the purification efficiency of the entire system. METHODS: We performed standard HFR in six uremic patients during 6 months and, subsequently, during a further 6 months, PDHFR was performed. The dialytic efficacy of the two techniques and the filter blood rest were evaluated. In addition, we studied the behavior of cytokines during the inverted HFR sessions. RESULTS: We observed a significant increase in urea extraction and in Kt/V. An equally significant improvement was observed with regard to beta2-microglobulin (beta2-m) extraction and blood rest. Furthermore, interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-alpha) significantly decreased after inverted HFR treatment. CONCLUSIONS: The inversion of the original configuration allowed us to improve the depurative efficacy of standard HFR, increasing the removal of both urea and beta2-m, and reducing the blood rest. Finally, it was notable that the reduction in cytokine levels could attenuate the uremic microinflammatory state.

Specific deficiency in nuclear factor-kappaB activation in neurons of the central nervous system.

The expression and activation of nuclear factor-kappaB (NF-kappaB) in neurons and glia of the central nervous system (CNS) has been intensely investigated because of its potential importance in understanding how this multifunctional transcription factor controls developmental and pathological processes. In particular, there has been interest in how NF-kappaB may be differentially regulated in these two major functional subgroups of cells in the CNS to provide for specific responses to various stimuli. Of special interest are responses to both proinflammatory cytokines and microbial products that signal from specific cell receptors to activate NF-kappaB. In the present studies, both neurons and glia (astrocytes) in vivo expressed latent cytoplasmic NF-kappaB analyzed by immunofluorescence microscopy and electrophoretic mobility shift analysis. In vitro, neurons and astrocytes expressed comparable levels of latent NF-kappaB molecules, but NF-kappaB nuclear localization stimulated by proinflammatory cytokines or microbial products was markedly deficient in neurons. In accord with this finding, the rapid degradation of inhibitor of NF-kappaB alpha (IkappaBalpha) that is seen in astrocytes did not occur in neurons in response to these agents. However, long-term exposure to translational inhibitors resulted in IkappaBalpha decay and activation of latent NF-kappaB in neurons, indicating potential NF-kappaB activity in these cells. Analysis of NF-kappaB-responsive interferon regulatory factor-1 gene expression indicated that increased nuclear NF-kappaB in neurons had transcriptional potential. We conclude that mechanisms responsible for inducible targeting of IkappaBalpha are uniquely regulated in neurons and account for the hypo-responsiveness of these cells to signals generated during microbial infections in the CNS. Thus, modulation of signals that target IkappaBalpha degradation may be unique and a key component of specific NF-kappaB regulation in neurons.

Novel NEMO/IkappaB kinase and NF-kappa B target genes at the pre-B to immature B cell transition.

The IkappaB kinase (IKK) signaling complex is responsible for activating NF-kappaB-dependent gene expression programs. Even though NF-kappaB-responsive genes are known to orchestrate stress-like responses, critical gaps in our knowledge remain about the global effects of NF-kappaB activation on cellular physiology. DNA microarrays were used to compare gene expression programs in a model system of 70Z/3 murine pre-B cells versus their IKK signaling-defective 1.3E2 variant with lipopolysaccharide (LPS), interleukin-1 (IL-1), or a combination of LPS + phorbol 12-myristate 13-acetate under brief (2 h) or long term (12 h) stimulation. 70Z/3-1.3E2 cells lack expression of NEMO/IKKgamma/IKKAP-1/FIP-3, an essential positive effector of the IKK complex. Some stimulated hits were known NF-kappaB target genes, but remarkably, the vast majority of the up-modulated genes and an unexpected class of repressed genes were all novel targets of this signaling pathway, encoding transcription factors, receptors, extracellular ligands, and intracellular signaling factors. Thirteen stimulated (B-ATF, Pim-2, MyD118, Pea-15/MAT1, CD82, CD40L, Wnt10a, Notch 1, R-ras, Rgs-16, PAC-1, ISG15, and CD36) and five repressed (CCR2, VpreB, lambda5, SLPI, and CMAP/Cystatin7) genes, respectively, were bona fide NF-kappaB targets by virtue of their response to a transdominant IkappaBalphaSR (super repressor). MyD118 and ISG15, although directly induced by LPS stimulation, were unaffected by IL-1, revealing the existence of direct NF-kappaB target genes, which are not co-induced by the LPS and IL-1 Toll-like receptors.

HTLV type 1 Tax transduction in microglial cells and astrocytes by lentiviral vectors.

Infection with human T cell leukemia virus type 1 (HTLV-1) can result in the development of HAM/TSP, a nonfatal, chronic inflammatory disease involving neuronal degeneration and demyelination of the central nervous system. Elevated levels of the proinflammatory cytokines tumor necrosis factor alpha (TNF-alpha), interleukin-6 (IL-6), and IL-1 observed in the cerebrospinal fluid of HAM-TSP patients suggest that cytokine dysregulation within the CNS is involved in neuropathogenesis. HTLV-1 infection and enhanced expression of TNF-alpha by microglial cells, astrocytes, and macrophages has been hypothesized to lead to the destruction of myelin and oligodendrocytes in the CNS. Although the association of HTLV-2 infection and development of neurological disease is more tenuous, HTLV-2 has also been found to be associated with peripheral neuropathies. To investigate the roles of HTLV Tax(1) and Tax(2) in the induction of cytokine disregulation in these cell types, we are currently developing gene delivery vectors based on human immunodeficiency virus type-1 (HIV-1) capable of stably coexpressing the HTLV-1 or -2 tax and eGFP reporter genes in primary human cells. Transduction frequencies of up to 50%, as assessed by eGFP expression, can be achieved in human monocyte-derived macrophages and in explanted cultures of human microglia. Preliminary data suggest that Tax(1) expression is sufficient to up-regulate the proinflammatory cytokine profile in explanted human microglial cells. Future experiments will compare and evaluate the effect of tax(1) and tax(2) gene expression on the cellular proinflammatory cytokine expression profile, as well as demonstrate the effects of transducing human fetal astrocytes and PBMC-derived macrophages.

Expression and function of the protein tyrosine phosphatase SHP-1 in oligodendrocytes.

Previous studies in this laboratory have shown that the SH-2 domain-containing protein tyrosine phosphatase SHP-1 is expressed in CNS glia and functions to modulate cytokine activities in these cells. The present study demonstrates that SHP-1 is expressed within multiple regions of the CNS in vivo, especially in white matter. Interestingly, we show that mice genetically lacking in SHP-1 (motheaten mice) in the CNS displayed dysmyelination. We therefore examined the expression of SHP-1 in the myelin-forming oligodendrocytes. Oligodendrocytes present in either mixed glial cultures or pure cultures expressed high levels of SHP-1 in the cytoplasm of cell bodies and processes. Oligodendrocytes isolated from motheaten mice did not express SHP-1. To test possible functions for SHP-1 in oligodendrocytes in controlling cytokine signaling, we compared the responsiveness of oligodendrocytes isolated from either motheaten or normal littermate mice with IL-6. IL-6 induced higher levels of STAT3 phosphorylation and STAT3-responsive c-fos gene expression in pure oligodendrocyte cultures of motheaten compared with normal littermate mice. These studies demonstrate that oligodendrocytes express SHP-1 and that SHP-1 functions to control IL-6 signaling. SHP-1 may therefore be a critical regulator of oligodendrocyte differentiation in response to IL-6 family cytokines. Further, these findings may relate to dysmyelination in mice lacking SHP-1.

A mechanism for selective induction of 2'-5' oligoadenylate synthetase, anti-viral state, but not MHC class I genes by interferon-beta in neurons.

Interferon-inducible expression of major histocompatibility class I genes has previously been found to be quantitatively and functionally deficient in neurons compared to other somatic cells or other neural cell types including astrocytes. This deficiency is a key component of neuronal immunoprivilege during viral infections of the CNS. To the contrary, in the present study, induction of functional antiviral state by IFN-beta in neurons compared to astrocytes was found to be highly efficient with respect to both viral replication and protection from cytopathic effects. A candidate antiviral state gene found to be efficiently induced in neurons by IFN-beta was the 2'-5'-oligoadenylate synthetase (OAS) gene. Unlike MHC class I genes, induction of OAS was comparable in neurons and astrocytes indicating differential expression in these neural cell types. Analysis of OAS gene promoter activity indicated that induction of the OAS gene by IFN-beta was dependent on a region containing the interferon stimulated responsive element (ISRE). In contrast, a construct containing the MHC class I-ISRE responsible for induction by IFN-beta in astrocytes was not responsive to IFN-beta in neurons. Therefore, transcription factor binding to the OAS- and MHC-ISREs was analyzed. While the OAS and MHC Class I site bound equal amounts of the transcriptional repressor IRF-2, the OAS-ISRE preferentially interacted with the transcriptional activator ISGF3 in response to IFN-beta. Further, unlike neurons, upregulation of MHC class I genes in astrocytes was related to binding of IRF-1 instead of IRF-2 to the MHC-ISRE. It is proposed that selective activation of anti-viral state genes compared to MHC class I genes by IFN-beta in neurons is mediated by preferential induction and binding of ISGF3 to anti-viral state gene ISREs but not the MHC-ISRE.

Mesalazine foam (Salofalk foam) in the treatment of active distal ulcerative colitis. A comparative trial vs Salofalk enema. The SAF-3 study group.

BACKGROUND: Mesalazine enemas are of well proven efficacy for the topical treatment of distal ulcerative colitis. Although new rectal formulations of mesalazine are not expected to be superior in efficacy and tolerability to standard formulations, they may offer secondary advantages in terms of overall acceptability. AIM: To compare the efficacy, tolerability and overall acceptability of a new mesalazine rectal foam (Salofalk foam) with mesalazine enema in the treatment of active distal ulcerative colitis. PATIENTS AND METHODS: A multicentre study was carried out in patients with active proctitis, proctosigmoiditis and left-sided ulcerative colitis as evaluated by the Clinical Activity Index (CAI > or =4) and Endoscopic Index (EI > or =6). Patients were randomly assigned to receive, in open-label fashion, either mesalazine foam 2 g twice a day or mesalazine enema (2 g/60 ml twice a day) for 3 weeks. Patients who did not achieve remission (defined as CAI <4 and EI <6) after 3 weeks continued the study receiving the alternative galenic formulation for a further 3 weeks. RESULTS: A total of 195 patients were enrolled. Characteristics at baseline were similar except for concomitant therapy with oral 5-ASA products: during the 1st treatment phase, 41% of patients on enema received such treatment vs only 29% of those on foam. Patients with at least one post-treatment efficacy evaluation were included in the intent-to-treat analysis (n=89 foam, n=96 enema). After 3 weeks of treatment, 112 patients were in remission and only 59 patients entered the 2nd treatment phase thus providing data on acceptability. Remission was achieved after 3 weeks in 54% of patients treated with foam and in 67% of those treated with enema. The 90% confidence interval for the difference in remission rates was 0 to 24 and thus within the clinically acceptable range of therapeutic equivalence. At the end of the 2nd phase, 70% of patients switched to foam were in remission vs 65% to the enema. Two patients discontinued treatment with foam prematurely due to anal burning. No clinically important changes were seen in the laboratory tests. CONCLUSIONS: Salofalk foam and enema are equally effective for the treatment of proctitis, proctosigmoiditis and left-sided ulcerative colitis. The new foam preparation is as well tolerated and accepted as enemas and can be used as a therapeutic alternative to conventional mesalazine enema formulations.

Increased inducible activation of NF-kappaB and responsive genes in astrocytes deficient in the protein tyrosine phosphatase SHP-1.

The protein tyrosine phosphatase SHP-1 is critical for controlling cytokine signaling through the Jak-Stat pathway and, consequently, for controlling inflammatory cellular immune responses dependent on these cytokines. However, the role of SHP-1 in regulating proinflammatory signaling may be incompletely understood, and it may control other distinct inflammatory agents. The present study analyzed the ability of tumor necrosis factor-alpha (TNF-alpha), double-stranded RNA, and interferon-gamma (IFN-gamma) to induce the transcription factor NF-kappaB in astrocytes expressing or lacking SHP-1. On exposure to the inducers, NF-kappaB was markedly increased in astrocytes obtained from motheaten mice lacking SHP-1 compared with normal littermate cells expressing SHP-1, consisted of p50 and p65 subunits, and was induced in a protein synthesis-independent manner. The increased nuclear NF-kappaB expression coincided with elevated loss of the cytoplasmic inhibitor IkappaB alpha in motheaten mouse cells. Enhanced NF-kappaB expression in motheaten mouse cells correlated with increased expression of genes with functional kappaB sites, including IFN regulatory factor-1 (IRF-1) and inducible nitric oxide synthase (iNOS) genes. MHC class I molecules were also increased in motheaten cells, consistent with the increased expression of IRF-1. Together, the data indicate an increased sensitivity of cells lacking SHP-1 to various inducers of NF-kappaB. Therefore, the regulation of not only Stats but also of NF-kappaB by SHP-1 may be important in controlling events promoted by proinflammatory agents in vivo that are especially apparent in multiple tissues of motheaten mice. This study suggests an additional role for SHP-1 in controlling specific and nonspecific immune responses where induction of NF-kappaB is involved.

C2H2-171: a novel human cDNA representing a developmentally regulated POZ domain/zinc finger protein preferentially expressed in brain.

We describe a novel human zinc finger cNDA. C2H2-171. This cDNA represents an mRNA which encodes a protein of 484 amino acids and a calculated molecular weight of 54 kD. Four zinc finger-like domains are found in the C-terminal end of the protein. At the N-terminus, C2H2-171 contains a POZ/tramtrack-like domain similar to that found in the tumor associated zinc finger proteins LAZ-3/BCL-6 and PLZ-F, as well as in non-zinc finger proteins. C2H2-171 RNA is preferentially expressed in the brain, and increases during the course of murine development, with maximal expression in the adult. C2H2-171 RNA is differentially expressed in brain regions, with the highest level of expression in the cerebellum. C2H2-171 RNA was expressed at high levels in primary cerebellar granule cell neurons compared to astrocytes. The gene encoding C2H2-171 is highly conserved in vertebrates, and maps to the terminus of human chromosome 1 (1q44-ter). This chromosomal location is associated with a number of cytogenetic aberrations including those involving brain developmental anomalies and tumorigenesis. These data suggest that C2H2-171 may play an important role in vertebrate brain development and function.

The role of protein tyrosine phosphatase SHP-1 in the regulation of IFN-gamma signaling in neural cells.

The role for protein tyrosine phosphatase SHP-1 in controlling signal transduction by IFN-gamma in astrocytes was studied. IFN-gamma induced the gamma-activated factor (GAF) within 30 min and GAF subsequently declined by 8 h after treatment. However, treatment with IFN-gamma in the presence of protein tyrosine phosphatase inhibitor vanadate blocked the decrease in GAF activity. The increased stability of GAF in vanadate-treated cultures was similarly observed in astrocytes of motheaten mice, which specifically lack the protein tyrosine phosphatase SHP-1. Prolongation of GAF activity coincided with increased expression of the IFN-inducible transcription factor, IFN-regulatory factor-1 (IRF-1). Increased IRF-1 was coincident with increased expression of MHC class I molecules in astrocytes in accordance with the activity of IRF-1 in the promoter region. These data implicate an important role for protein tyrosine phosphatases, including SHP-1, in the regulation of IFN-gamma-signaling and IFN-gamma-inducible genes in neural cells.

Modulation of major histocompatibility complex class I genes by interferon-gamma and ganglioside GT 1b in astrocytes: involvement of protein tyrosine phosphatases.

We have previously reported that the polysialoganglioside GT1b suppresses the induction of major histocompatibility complex class I molecules by interferon-gamma in astrocytes. Suppression by GT1b depended on the presence of sialic acid moieties because asialo-GM1 was not suppressive. In the present report, GT1b was found to act transcriptionally to suppress class I genes because both the interferon-gamma induction of RNA and the activity of class I promoter constructs were inhibited. Furthermore, GT1b suppressed promoter activity through interferon regulatory factor elements, indicating an effect on the transcription activation factor, interferon regulatory factor 1. Interferon-gamma induced interferon regulatory factor 1 within 8 h, and GT1b suppressed this induction. The suppression of interferon regulatory factor 1 by GT1b correlated with the suppression of gamma-activated factor binding at the promoter of the interferon regulatory factor 1 gene. The suppression of gamma-activated factor by GT1b appeared to involve increased protein tyrosine phosphatase activity because treatment of the cells with pervanadate reversed the effect of GT1b on the gamma-activated factor and, correspondingly, phosphotyrosine content. In sum, GT1b displays specific effects on interferon-gamma signaling and negative feedback regulatory molecules in astrocytes.

Interferon regulatory factor element and interferon regulatory factor 1 in the induction of major histocompatibility complex class I genes in neural cells.

The role of the MHC-IRF-E and interferon regulatory factor 1 (IRF-1) in the regulation of MHC class I genes in astrocytes was analyzed. Transcriptional activation of MHC class I genes after treatment of astrocytes with various inducers occurred over a period of hours and correlated with cell surface expression. Functional analysis of the MHC class I gene promoter region confirmed that induction was controlled by a restricted region of 88 base pairs containing two well-defined inducible enhancers, the MHC-CRE and the MHC-IRF-E. Further analysis showed that potential MHC-CRE enhancer activity was silent. Therefore, the MHC-IRF-E, rather than the MHC-CRE, appeared responsible for enhancement of the MHC class I gene and was supported by three findings: (1) site-directed mutation of the MHC-IRF-E-abrogated induction, (2) promoter constructs containing IRF-Es as the sole enhancers were highly inducible in astrocytes, and (3) the expression of transcription factor IRF-1, which acts through the MHC-IRF-E to induce MHC class I genes, was induced to high levels in parallel with that of MHC class I induction. The induction of the IRF-1 gene correlated with the prior induction of the gamma-activated factor (GAF) or NF-kappa B, depending on the inducer, indicating that both gamma activation sites (GAS) and kappa B sites in the IRF-1 promoter are important.(ABSTRACT TRUNCATED AT 250 WORDS)

Neuron-specific regulation of major histocompatibility complex class I, interferon-beta, and anti-viral state genes.

The regulation of major histocompatibility complex (MHC) class I, interferon (IFN)-beta, and anti-viral state expression in neurons was analyzed. Treatment of neurons with either double-stranded RNA (poly I: poly C) or virus, but not IFNs, induced high levels of IFN-beta, but not MHC class I genes. However, neurons treated with IFN-beta established an anti-viral state. Transfection of neurons with IFN-beta constructs showed that a region containing PRDI (IRF-E site) and PRDII (kappa B site) mediated induction, but closely related sites in a MHC class I construct did not. Gel mobility shift assays indicated that transcription factors containing the RelA (p65) component of NF-kappa B, but not p50, bound to PRDII. PRDI, however, bound to transcriptional antagonist IRF-2. Unique selective induction of these transcription factors is likely to mediate non-coordinate expression of IFN-beta, MHC class I, and anti-viral state genes in neurons.

Oligodendrocyte-specific expression and autoantigenicity of transaldolase in multiple sclerosis.

Although the etiology of multiple sclerosis (MS) is unknown, there is compelling evidence that its pathogenesis is mediated through the immune system. Molecular mimicry, i.e., crossreactivity between self-antigens and viral proteins, has been implicated in the initiation of autoimmunity and MS. Based on homology to human T cell lymphotropic virus type I (HTLV-I) a novel human retrotransposon was cloned and found to constitute an integral part of the coding sequence of the human transaldolase gene (TAL-H). TAL-H is a key enzyme of the nonoxidative pentose phosphate pathway (PPP) providing ribose-5-phosphate for nucleic acid synthesis and NADPH for lipid biosynthesis. Another fundamental function of the PPP is to maintain glutathione at a reduced state and, consequently, to protect sulfhydryl groups and cellular integrity from oxygen radicals. Immunohistochemical analyses of human brain sections and primary murine brain cell cultures demonstrated that TAL is expressed selectively in oligodendrocytes at high levels, possibly linked to production of large amounts of lipids as a major component of myelin, and to the protection of the vast network of myelin sheaths from oxygen radicals. High-affinity autoantibodies to recombinant TAL-H were detected in serum (25/87) and cerebrospinal fluid (15/20) of patients with MS. By contrast, TAL-H antibodies were absent in 145 normal individuals and patients with other autoimmune and neurological diseases. In addition, recombinant TAL-H stimulated proliferation and caused aggregate formation of peripheral blood lymphocytes from patients with MS. Remarkable amino acid sequence homologies were noted between TAL-H and core proteins of human retroviruses. Presence of crossreactive antigenic epitopes between recombinant TAL-H and HTLV-I/human immunodeficiency virus type 1 (HIV-1) gas proteins was demonstrated by Western blot analysis. The results suggest that molecular mimicry between viral core proteins and TAL-H may play a role in breaking immunological tolerance and leading to a selective destruction of oligodendrocytes in MS.

Specific suppression of major histocompatibility complex class I and class II genes in astrocytes by brain-enriched gangliosides.

The effect of brain-enriched gangliosides on constitutive and cytokine-inducible expression of major histocompatibility complex (MHC) class I and II genes in cultured astrocytes was studied. Before treatment with gangliosides, astrocytes expressed constitutive MHC class I but not class II molecules, however, the expression of both MHC class I and II cell surface molecules on astrocytes was induced to high levels by interferon gamma (IFN-gamma). Constitutive and IFN-gamma-inducible expression of MHC class I and II molecules was suppressed by treatment of astrocytes with exogenous bovine brain gangliosides in a dose-dependent manner. Constitutive and induced MHC class I and II mRNA levels were also suppressed by gangliosides, indicating control through transcriptional mechanisms. This was consistent with the ability of gangliosides to suppress the binding activity of transcription factors, especially NF-kappa B-like binding activity, important for the expression of both MHC class I and II genes. These studies may be important for understanding mechanisms of central nervous system (CNS)-specific regulation of major histocompatibility molecules in neuroectodermal cells and the role of gangliosides in regulating MHC-restricted antiviral and autoimmune responses within the CNS.

Cell type-specific regulation of major histocompatibility complex (MHC) class I gene expression in astrocytes, oligodendrocytes, and neurons.

Mechanisms of major histocompatibility complex (MHC) class I gene regulation in cells of the CNS have been studied in vitro. Astrocytes in primary cultures, but neither oligodendrocytes nor neurons, constitutively expressed cell surface MHC class I molecules. Interferon-gamma (IFN-gamma) treatment led to induction of MHC class I expression in astrocytes and oligodendrocytes but not in neurons. The conserved upstream sequence containing the juxtaposed nuclear factor (NF)-kappa B-like region I and IFN-response consensus sequence (ICS) constitutively enhanced MHC class I gene promoter activity in astrocytes, but not in oligodendrocytes or in neurons. Nuclear extracts from astrocytes, but not from oligodendrocytes and neurons, had a binding activity specific for the NF-kappa B-like region I sequence, indicating that constitutive expression of MHC class I genes is governed by the upstream region I enhancer and its binding factor. IFN-gamma treatment led to induction of MHC class I promoter activity in astrocytes and oligodendrocytes, but not in neurons. In accordance with this observation, a nuclear factor that binds to the ICS was induced in astrocytes and oligodendrocytes but not in neurons following IFN-gamma treatment. This study illustrates cell type-specific regulation of MHC class I genes in the CNS that correlates with the expression of DNA binding factors relevant to MHC class I gene transcription.

Expression of major histocompatibility complex (MHC) class I genes in astrocytes correlates with the presence of nuclear factors that bind to constitutive and inducible enhancers.

The molecular basis of constitutive and inducible major histocompatibility complex (MHC) class I gene expression was studied in murine astrocytes in primary culture. Astrocytes constitutively expressed MHC class I molecules and treatment of these cells with interferon-gamma (IFN-gamma) further induced expression. The conserved region containing the upstream MHC class I regulatory element (MHC-CRE) and juxtaposed interferon consensus sequence (ICS) enhanced constitutive MHC class I promoter activity. As seen with cell surface expression of MHC molecules, treatment of astrocytes with IFN-gamma increased MHC class I promoter activity. Inducible expression required the presence of the MHC-CRE/ICS enhancer region. Nuclear factors that bind to the MHC-CRE and ICS were constitutively expressed in cultured astrocytes and IFN-gamma treatment further induced binding activity both to the MHC-CRE and ICS and correlated with induction of MHC class I gene expression. This study identifies the MHC-CRE and ICS as the major cis elements in controlling MHC class I promoter activity and suggests that the expression of nuclear factor binding activities to these enhancer elements is a basic transactivating mechanism for the expression of MHC class I genes in astrocytes.

HbH disease in Sardinia: molecular, hematological and clinical aspects.

In this study we have defined the molecular basis and correlated the clinical phenotype with the alpha-globin genotype in a large series of patients of Sardinian descent with HbH disease. The most prevalent molecular defect was the deletion of 3 alpha-globin structural genes most commonly the (--/-alpha 3.7) genotype (83.6%) and rarely the (--/-alpha 4.2) genotype (1.4%), followed in decreasing order of incidence by the combination of deletion alpha zero-thalassemia and initiation codon mutation of the alpha 2-gene (--/alpha NcoI alpha = 9.8%), deletion alpha zero-thalassemia and pentanucleotide deletion of IVS-I of the alpha 2-globin gene, (--/alpha HphI alpha = 3.3%) deletion alpha zero-thalassemia and initiation codon mutation of the alpha 1-gene (--/alpha alpha NcoI = 1.3%), a homozygous state for initiation codon mutation of the alpha 2-gene (alpha Nco alpha/alpha NcoI alpha = 0.7%). Patients with the (--/alpha thal alpha) genotypes showed severer clinical and hematological features as compared to those with the (--/-alpha) or those with the (--/alpha alpha thal) genotypes. The single patient with the (alpha Nco alpha/alpha Nco alpha) genotype had a clinical phenotype intermediate between HbH disease and the alpha-thalassemia carrier status. This heterogeneity depends on the fact that the alpha 2-globin gene produces 2-3 times alpha-globin chains than the alpha 1-gene and the single remaining alpha 1-like globin gene in the -alpha 3.7 chromosome has a compensatory increase in the alpha-globin chain output. alpha-Globin gene mapping of HbH disease patients may be useful for predicting the clinical outcome and to improve genetic counseling.

[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.

A single-blind pilot study comparing standard and half bedtime doses of ranitidine in the short-term healing of duodenal ulcer.

In this two-center, pilot trial we assessed the efficacy of single bedtime does of 150 mg ranitidine (half dose) and 300 mg ranitidine (full dose) in promoting duodenal ulcer healing by comparing the proportions of healed ulcers after 4 and 8 weeks of treatment. One hundred thirty-nine patients (106 men) were randomly allocated according to a prearranged treatment schedule to either dose and were treated single-blind (endoscopist). One hundred twenty-six patients (63 given 150 mg ranitidine and 63 given 300 mg) completed the trial. In the per-protocol analysis, 55 patients given full doses (81%) and 47 given half doses (70%) of ranitidine had healed ulcers at 4 weeks. Sixty full-dose and 55 half-dose patients (95% and 87%, respectively), had healed ulcers at 8 weeks. The difference was not significant using the chi 2 test (two-tailed), but the 95% confidence limits were in favor of the 300-mg dose. This study had a 75% power to detect a 25% difference in healing rates between the two groups.