Activated innate immunity and the involvement of CX3CR1-fractalkine in promoting hematuria in patients with IgA nephropathy

A hallmark of immunoglobulin A nephropathy (IgAN) is episodes of gross hematuria coinciding with mucosal infections that can represent the disease-triggering event. Here we performed a whole genomic screen of IgAN patients during gross hematuria to clarify the link between mucosal antigens and glomerular hematuria. Modulated genes showed a clear involvement of the intracellular interferon signaling, antigen-presenting pathway, and the immunoproteasome. The mRNA and protein level of the chemokine receptor characterizing cytotoxic effector lymphocytes, CX3CR1, was upregulated. In vitro antigenic stimulation of peripheral blood mononuclear cells from IgAN patients, healthy blood donors, and other nephropathies with microscopic hematuria showed that only in IgAN patients was CX3CR1 enhanced in a dose-dependent manner. A significantly higher amount of glomerular and urinary fractalkine, the only ligand of CX3CR1, was also found in IgAN patients with recurrent episodes of gross hematuria compared with other patients with microscopic or no hematuria. This suggests a predisposition for cytotoxic cell extravasation only in patients with recurrent gross hematuria. Thus, we found a defect in antigen handling in peripheral blood mononuclear cells of IgAN patients with a specific increase of CX3CR1. This constitutive upregulation of glomerular and urinary fractalkine suggests an involvement of the CX3CR1-fractalkine axis in the exacerbation of gross hematuria.     

Effect of prolonged incubation with copper on endothelium-dependent relaxation in rat isolated aorta

1 We investigated the effects of prolonged exposure to copper (Cu(2+)) on vascular functioning of isolated rat aorta. 2 Aortic rings were exposed to CuSO(4) (3-24 h) in Dulbecco's modified Eagle medium with or without 10% foetal bovine serum (FBS) and then challenged with vasoconstrictors or vasodilators in the absence of Cu(2+). 3 Exposure to 2 micro M Cu(2+) in the absence of FBS did not modify the response to phenylephrine (PE) or acetylcholine (ACh) in aortic rings incubated for 24 h. Identical exposure in the presence of FBS increased the contractile response to 1 micro M PE by 30% (P<0.05) and impaired the relaxant response to 3 micro M ACh or 1 micro M A23187 (ACh, from 65.7+/-7.1 to 6.2+/-1.1%, n=8; A23187, from 74.6+/-8.2 to 12.0+/-0.8%, n=6; P<0.01 for both). Cu(2+) exposure did not affect the relaxant response to NO-donors. 4 Impairment of vasorelaxation appeared 3 h after incubation with 2 micro M Cu(2+) and required 12 h to attain a steady state. Vasorelaxation to ACh was partially restored by 1 mM tiron (intracellular scavenger of superoxide ions; maximum relaxation 34.2+/-6.4%, n=10, P<0.01 vs Cu(2+) alone), whereas catalase, superoxide dismutase or cycloheximide were ineffective. 5 Twenty-four hour-exposure to 2 micro M Cu(2+) did not affect endothelium integrity or eNOS expression, and increased the Cu content in arterial rings from 6.8+/-1.1 to 18.9+/-2.9 ng mg(-1) wet weight, n=8; P<0.01. 6 Our results show that, in the presence of FBS, prolonged exposure to submicromolar concentrations of Cu(2+) impaired endothelium-dependent vasorelaxation in aortic rings, probably through an intracellular generation of superoxide ions. British Journal of Pharmacology (2002) 136, 1185-1193     

Early detection of secondary caries using quantitative,light-induced fluorescence

The authors hypothesize that the arrestment and remineralization of these lesions could be improved if secondary caries could be detected and monitored at earlier stages. Traditional diagnostic techniques detect secondary caries when it is relatively advanced and when significant tissue has been lost. This in vitro study evaluated the Quantitative Light-induced Fluorescence (QLF) system for detecting and monitoring demineralization surrounding tooth-colored restorations. This investigation was divided into three studies. The first study evaluated QLF for the detection and measurement of chemically induced lesions surrounding resin composite restorations. The second study evaluated QLF for the detection of demineralization around different tooth-colored restorations (glass ionomer, resin composite, compomer and smart material) created in a microbial caries model. Finally, the third study tested whether QLF was effective at detecting early wall lesions adjacent to resin composite restorations. Data from Study 1 demonstrated the potential for QLF to detect very early secondary caries and to distinguish between the different stages of early demineralization. Study 2 confirmed the potential for QLF to detect early secondary caries created by cariogenic bacteria and concluded that the four types of materials differed in their ability to prevent secondary caries in this model, with the glass ionomer being the most effective and the non-fluoride releasing composite performing the worst, which allowed for the development of larger lesions. The results of Study 3 suggest a potential application of the QLF system to detect early wall lesions. Data from this investigation strongly suggest that QLF is a potentially viable technology to detect and monitor early secondary caries.     

In vitro and in vivo downregulation of MRP1 by antisense oligonucleotides: a potential role in neuroblastoma therapy

The expression of MRP1 (multidrug resistance protein-1) is associated with chemoresistance and poor prognosis in neuroblastoma. MRP1 antisense oligonucleotides were used in an in vivo mouse-human xenograft model of neuroblastoma to downregulate MRP1. The MRP1 ASO reduced protein levels of MRP1 to an average of 40% of the nil treated controls (p = 0.007). There was significant chemosensitisation to single-agent chemotherapy, VP16 (etoposide), at 1 microg/mL (p = 0.035) and 10 microg/mL (p = 0.02) in comparison to tumours not receiving oligonucleotides. In contrast, MDR1-ASO produced significant chemosensitisation only at 10 microg/mL of VP16 (p = 0.029). No significant chemosensitisation was seen following nonsense oligonucleotides. The downregulation of MRP1 was also associated with an increase in tumour cell death (79% increase in apoptosis index p = 0.0313) and a reduction in cell turnover (42% reduction in mitotic index p = 0.0313), which was not seen with any other oligonucleotide. This new and novel perspective of MRP1 function, which is an apparent involvement in apoptosis and cell cycle progression in neuroblasts, presents a fresh avenue for investigation of the biologic consequences of MRP1 expression that occurs in many tumour cell types. Our work is the first to concurrently explore the effects of downregulation of MRP1 and MDR1 by antisense oligonucleotides in a neuroblastoma xenograft model. It provides rationale for the investigation of therapy adjuvants such as antisense oligonucleotides in the treatment of this malignancy.     

A genome-wide scan for linkage to chromosomal regions in 382 sibling pairs with schizophrenia or schizoaffective disorder

OBJECTIVE: Some genome-wide scans and association studies for schizophrenia susceptibility genes have yielded significant positive findings, but there is disagreement between studies on their locations, and no mutation has yet been found in any gene. Since schizophrenia is a complex disorder, a study with sufficient power to detect a locus with a small or moderate gene effect is necessary. METHOD: In a genome-wide scan of 382 sibling pairs with a diagnosis of schizophrenia or schizoaffective disorder, 396 highly polymorphic markers spaced approximately 10 centimorgans apart throughout the genome were genotyped in all individuals. Multipoint nonparametric linkage analysis was performed to evaluate regions of the genome demonstrating increased allele sharing, as measured by a lod score. RESULTS: Two regions with multipoint maximum lod scores suggesting linkage were found. The highest lod scores occurred on chromosome 10p15-p13 (peak lod score of 3.60 at marker D10S189) and the centromeric region of chromosome 2 (peak lod score of 2.99 at marker D2S139). In addition, a maximum lod score of 2.00 was observed with marker D22S283 on chromosome 22q12, which showed evidence of an imprinting effect, whereby an excess sharing of maternal, but not paternal, alleles was present. No evidence of linkage was obtained at several locations identified in previous studies, including chromosomes 1q, 4p, 5p-q, 6p, 8p, 13q, 15p, and 18p. CONCLUSIONS: The findings of this large genome-wide scan emphasize the weakness and fragility of linkage reports on schizophrenia. No linkage appears to be consistently replicable across large studies. Thus, it has to be questioned whether the genetic contribution to this disorder is detectable by these strategies and the possibility raised that it may be epigenetic, i.e., related to gene expression rather than sequence variation. Nevertheless, the positive findings on chromosome 2, 10, and 22 should be pursued further.     

Antidepressant drug consumption and public health indicators in Italy, 1955 to 2000

OBJECTIVE: This study investigated the impact of the increasing consumption of selective serotonin reuptake inhibitors (SSRIs) and newer anti-depressants on the following public health indicators: (1) suicide rates, (2) proportion of completed suicides by poisoning with solid or liquid substances, and (3) hospital admissions for depression and proportion of admissions for depression that were first admissions. METHOD: Data collected by IMS Health on antidepressants dispensed in Italy from 1983 to 2000 were obtained from the Italian Ministry of Health, while data on suicide deaths from 1955 to 2000 were obtained from the Italian National Institute of Statistics. RESULTS: In Italy from 1983 to 2000, the use of tricyclic antidepressants remained substantially stable, and the use of SSRIs and newer agents dramatically increased. In contrast, suicide rates for males decreased from 1955 to 1974 and subsequently increased, reaching a peak in 1985 and then declining. In females, suicide rates remained substantially stable until 1978. A subsequent increase occurred up to 1985, followed by a steady decline. Suicide by poisoning using solids or liquids dropped by nearly 50% from 1986 to 2000. Admissions to the hospital for depression showed an erratic pattern; however, no decline was observed. No change was observed in the rate of first admissions for depression. CONCLUSION: Despite a reduction in suicides by poisoning using solids or liquids, the analysis of long-term trends in suicide did not suggest that increases in antidepressant prescribing lie behind recent reductions in population suicides. Furthermore, in Italy, newer antidepressants had no impact on the total number of admissions for depression or on the proportion of all admissions that were first admissions.