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R Mariani

Publications and source records attributed to R Mariani.

At least 19 recordsLinked to original sources
PubMed2003

Inhibition of spontaneous and androgen-induced prostate growth by a nonhypercalcemic calcitriol analog.

We have recently found that analog V (BXL-353, a calcitriol analog) inhibits growth factor (GF)-stimulated human benign prostate hyperplasia (BPH) cell proliferation by disrupting signal transduction, reducing Bcl-2 expression, and inducing apoptosis. We now report that BXL-353 blocks in vitro and in vivo testosterone (T) activity. BPH cells responded to T and dihydrotestosterone (DHT) with dose-dependent growth and reduced apoptosis. Exposure of BPH cells to BXL-353 significantly antagonized both T- and DHT-induced proliferation and induced apoptosis, even in the presence of T. To verify whether BXL-353 reduced prostate growth in vivo, we administered it orally to either intact or castrated rats, supplemented with T enanthate. Nonhypercalcemic doses of BXL-353 time- and dose-dependently reduced the androgen effect on ventral prostate weight, similarly to finasteride. Comparable results were obtained after chronic administration of BXL-353 to intact rats. Clusterin (an atrophy marker) gene and protein were up-regulated by BXL-353 in rat prostate, and nuclear fragmentation was widely present. The antiandrogenic properties of BXL-353 did not interfere with pituitary and testis function, as assessed by serum determination of rat LH and T. BXL-353 did not compete for androgen binding to BPH homogenates and failed to inhibit 5alpha-reductase type 1 and type 2 activities. In conclusion, BXL-353 blocks in vitro and in vivo androgen-stimulated prostate cell growth, probably acting downstream from the androgen receptor, without affecting calcemia or sex hormone secretion. BXL-353 and other vitamin D(3) analogs might thus represent an interesting class of compounds for treating patients with BPH.

3-Oxo-5-alpha-Steroid 4-Dehydrogenase↗
PubMed2001

Mouse-human heterokaryons support efficient human immunodeficiency virus type 1 assembly.

Murine cells do not support human immunodeficiency virus type 1 (HIV-1) replication because of blocks to virus entry, proviral expression, and virion assembly. In murine 3T3 fibroblasts, the block to HIV-1 entry is relieved by the introduction of human CD4 and CCR5 or CXCR4, and proviral expression is increased by the introduction of the Tat cofactor, human cyclin T1; however, because of the assembly block, virus fails to spread. A panel of rodent cell lines expressing human CD4, CCR5, and cyclin T1 was established and studied for the ability to support virus replication. Mus musculus lymphoid cell lines EL4 and L1-2 and Mus dunni fibroblasts supported only low levels of virus assembly and released small amounts of infectious virus. CHO and Rat2 cell lines produced more infectious virus, but this production was still 40-fold lower than production in human cells. Only CHO cells expressing the three human cofactors were partially permissive for HIV-1 replication. To investigate the basis of the block to HIV-1 assembly, mouse-human heterokaryons were tested for ability to assemble and release virus. Fusion of human cells to HIV-1-infected mouse cells expressing CD4, CCR5, and cyclin T1 caused a 12-fold increase in virion release and a 700-fold increase in infectious virus production. Fusion of HIV-1-infected M. dunni tail fibroblasts to uninfected human cells caused a similar increase in virus release. More efficient virus release was not caused by increased proviral transcription or increased synthesis of virion components. Analysis of reciprocal heterokaryons suggested the absence of an inhibitor of virus assembly. Taken together, the results suggested that murine fibroblasts lack a cofactor that is required for efficient virus assembly and release.

3T3 Cells↗
PubMed2000

Soluble CD40 ligand induces beta-chemokine production by macrophages and resistance to HIV-1 entry.

CD40 ligand (CD40L) is a cell surface molecule of CD4(+)T cells that interacts with its receptor CD40 on antigen presenting cells to mediate thymus-dependent humoral immunity and inflammatory reactions. We report here that treating monocyte-derived macrophages (MDM) with a trimeric soluble form of CD40L (CD40LT) induced them to secrete high levels of the beta-chemokines RANTES, MIP-1alpha and MIP-1beta that are ligands for CCR5 and able to inhibit HIV-1 entry. CD40LT inhibited the entry of M-tropic HIV-1 reporter viruses. Furthermore, supernatants obtained from CD40LT-stimulated macrophages protected CEMx174-CCR5 cells from infection by HIV-1(JRFL)reporter virus. The inhibitory activity appeared to be due to beta-chemokines present in the supernatant, since pretreating them with a cocktail of antibodies to RANTES, MIP-1alpha and MIP-1beta neutralized the inhibitory activity of the supernatants. In addition, treating monocytes with CD40LT caused CCR5 and CD4 to be downregulated from the cell surface. In vivo, macrophages activated through CD40 could interfere with HIV replication.

CD4 Antigens↗
PubMed2000

[Sweet syndrome in an infant].

BACKGROUND: Acute febrile neutrophilic dermatosis (Sweet's syndrome) is very uncommon in infancy. Systemic corticosteroid treatment is the standard therapy, usually leading to dramatic improvement within a few days. CASE REPORT: A seven-month-old female infant was admitted for investigation of a rash developing over ten days with fever. Physical examination and skin biopsy led to a diagnosis of Sweet's syndrome. The relative inefficiency of systemic corticotherapy induced the parents to stop all treatment. CONCLUSION: This case report allows us: 1) to consider the clinical and biological features of Sweet's syndrome in infancy; 2) to describe a corticosteroid resistant disease; and 3) to observe the course of a spontaneous evolution of Sweet's syndrome.

Adrenal Cortex Hormones↗
PubMed2000

A block to human immunodeficiency virus type 1 assembly in murine cells.

Human immunodeficiency virus type 1 (HIV-1) does not replicate in murine cells. We investigated the basis of this block by infecting a murine NIH 3T3 reporter cell line that stably expressed human CD4, CCR5, and cyclin T1 and contained a transactivatable HIV-1 long terminal repeat (LTR)-green fluorescent protein (GFP) cassette. Although the virus entered efficiently, formed provirus, and was expressed at a level close to that in a highly permissive human cell line, the murine cells did not support M-tropic HIV-1 replication. To determine why the virus failed to replicate, the efficiency of each postentry step in the virus replication cycle was analyzed using vesicular stomatitis virus G pseudotypes. The murine cells supported reverse transcription and integration at levels comparable to those in the human osteosarcoma-derived cell line GHOST.R5, and human cyclin T1 restored provirus expression, consistent with earlier findings of others. The infected murine cells contained nearly as much virion protein as did the human cells but released less than 1/500 the amount of p24(gag) into the culture medium. A small amount of p24(gag) was released and was in the form of fully infectious virus. Electron microscopy suggested that aberrantly assembled virion protein had accumulated in cytoplasmic vesicular structures. Virions assembling at the cell membrane were observed but were rare. The entry of M-tropic JR.FL-pseudotyped reporter virus was moderately reduced in the murine cells, suggesting a minor reduction in coreceptor function. A small reduction in the abundance of full-length viral mRNA transcripts was also noted; however, the major block was at virion assembly. This could have been due to a failure of Gag to target to the cell membrane. This block must be overcome before a murine model for HIV-1 replication can be developed.

3T3 Cells↗
PubMed2000

Haemochromatosis in patients with beta-thalassaemia trait.

Severe iron overload has been reported in patients with the beta-thalassaemia trait. Studies performed before the discovery of the haemochromatosis gene (HFE) have yielded conflicting results: some suggest that iron overload might arise from the interaction of the beta-thalassaemia trait with heterozygosity for haemochromatosis, some with homozygosity for haemochromatosis and others that it was unrelated to haemochromatosis. We have studied the clinical phenotype, iron indices and HFE genotypes of 22 unrelated patients with the beta-thalassaemia trait and haemochromatosis, the inheritance of chromosome 6p and 1q haplotypes in families of non-homozygous C282Y probands and serum measures of iron status in relatives heterozygous for C282Y with or without the beta-thalassaemia trait. We demonstrate that the beta-thalassaemia trait aggravates the clinical picture of C282Y homozygotes, favouring higher rates of iron accumulation and the development of severe iron-related complications. We suggest that the coexistence of the beta-thalassaemia trait might also increase the risk of iron overload in patients with HFE genotypes at a mild risk of haemochromatosis. Our findings do not support the hypothesis that the association of the beta-thalassaemia trait with a single C282Y or H63D allele might lead to iron overload and suggest that other non-HFE-related inherited factors are present in haemochromatosis patients with incomplete HFE genotypes.

Adult↗
PubMed1999

CCR2-64I polymorphism is not associated with altered CCR5 expression or coreceptor function.

A polymorphism in the gene encoding CCR2 is associated with a delay in progression to AIDS in human immunodeficiency virus (HIV)-infected individuals. The polymorphism, CCR2-64I, changes valine 64 of CCR2 to isoleucine. However, it is not clear whether the effect on AIDS progression results from the amino acid change or whether the polymorphism marks a genetically linked, yet unidentified mutation that mediates the effect. Because the gene encoding CCR5, the major coreceptor for HIV type 1 primary isolates, lies 15 kb 3' to CCR2, linked mutations in the CCR5 promoter or other regulatory sequences could explain the association of CCR2-64I with slowed AIDS pathogenesis. Here, we show that CCR2-64I is efficiently expressed on the cell surface but does not have dominant negative activity on CCR5 coreceptor function. A panel of peripheral blood mononuclear cells (PBMC) from uninfected donors representing the various CCR5/CCR2 genotypes was assembled. Activated primary CD4(+) T cells of CCR2 64I/64I donors expressed cell surface CCR5 at levels comparable to those of CCR2 +/+ donors. A slight reduction in CCR5 expression was noted, although this was not statistically significant. CCR5 and CCR2 mRNA levels were nearly identical for each of the donor PBMC, regardless of genotype. Cell surface CCR5 and CCR2 levels were more variable than mRNA transcript levels, suggesting that an alternative mechanism may influence CCR5 cell surface levels. CCR2-64I is linked to the CCR5 promoter polymorphisms 208G, 303A, 627C, and 676A; however, in transfected promoter reporter constructs, these did not affect transcriptional activity. Taken together, these findings suggest that CCR2-64I does not act by influencing CCR5 transcription or mRNA levels.

Blood Donors↗
PubMed1998

[Cystic papillary tumor of the pancreas: a rare etiology of abdominal mass in children].

BACKGROUND: Malignant pancreatic tumors are very uncommon in childhood. CASE REPORT: A 13-year-old girl was admitted for investigation of an abdominal mass with fever. Ten months earlier, clinical examination performed for similar symptoms found an epigastric mass which resolved spontaneously. Radiological investigations showed a well-encapsulated cystic tumor in the pancreas. Excision revealed a papillary cystic tumor of the pancreas. CONCLUSION: Papillary cystic tumor of the pancreas is an unfrequent cause of abdominal mass in children. Its excellent prognosis after complete excision is quite different from that of other malignant pancreatic tumors.

Adolescent↗
PubMed1998

[Jacobsen's syndrome, thrombopenia and humoral immunodeficiency].

BACKGROUND: Clinical features of Jacobsen syndrome include facial dysmorphism, congenital heart defects, digit anomalies and mild to moderate psychomotor retardation. Thrombocytopenia or pancytopenia is observed in one half of patients. PATIENTS: Two unrelated children, a 6-month- and a 12-year-old, presented with a moderate thrombocytopenia associated with the clinical features of Jacobsen syndrome. Bone marrow aspirates showed, in both patients, normal cellularity with an increased number of micromegacaryocytes. Chromosome analysis showed a partial deletion of the long arm of chromosome 11. The 12-year-old patient had a history of upper respiratory airways infections with immune humoral deficiency (decreased level of IgA and IgM) which, to our knowledge, has never been reported. CONCLUSION: Jacobsen syndrome is a cause of inherited thrombocytopenia in children. Humoral immune functions must be explored in patients with a history of repeated infections.

Child↗
PubMed1997

Histiocytoid cardiomyopathy: a cause of sudden death in infancy.

We report the case of an infant aged of 14 months deceased of sudden death. The diagnosis of histiocytoid cardiomyopathy was made on a necropsic basis. The pathologic examination showed a cardiac hypertrophy characterized by yellowish areas with irregular outlines, disseminated in the myocardium, and made of histiocyte-like cells with foamy or granular cytoplasm. These cells reacted positively with desmin and myoglobin labels, and had rare and disorganised myofibrils in electron microscopy, proving their muscular origin. The illness affects infants and usually causes severe cardiac troubles leading to death without treatment. This case is the fourteenth associated with sudden death.

Cardiomyopathies↗
PubMed1996

Increased urinary catecholamines in a hypertensive child with renal artery stenosis.

We report a hypertensive child with renal artery stenosis who exhibited increased urinary excretion of norepinephrine (NE) and normetanephrine (NMN), while vanillylmandelic acid (VMA) excretion was within the normal range. The NMN values prompted us to investigate the patient for pheochromocytoma; for this purpose, NE was determined by plasma catecholamine assays in venous samples obtained by catheterization. The moderately increased NE levels could not be localized to any particular sampling site. Arteriography demonstrated right renal artery abnormalities. Following right nephrectomy with preservation of the right adrenal gland, arterial blood pressure returned to normal. The cause of increased NMN excretion without a concomitant rise in VMA during hypertension is discussed.

Angiography↗