Enhancement of lipopolysaccharide-stimulated cyclooxygenase-2 mRNA expression and prostaglandin E2 production in gingival fibroblasts from individuals with Down syndrome

It is well known that Down syndrome (DS) is a premature ageing syndrome. Periodontal disease in individuals with DS develops rapidly and extensively in a relatively younger age bracket compared with that in healthy controls. The mechanisms involved in the periodontal inflammatory processes in DS patients are not fully understood. In the present study, the non-inflamed gingival fibroblasts isolated from seven patients with DS (DGF) and seven healthy controls (NDGF) were stimulated with lipopolysaccharide (LPS) derived from Actinobacillus actinomycetemcomitans (A. a.). We measured the level of prostaglandin E2 (PGE2) production by DGF and NDGF by radioimmunoassay, and also measured the mRNA expression of cyclooxygenase-1 (COX-1) and cyclooxygenase-2 (COX-2) by using the real-time PCR method. We found the higher levels of LPS-stimulated COX-2 mRNA expression and PGE2 production in DGF when compared with those in NDGF. This study may indicate that overexpression of LPS-stimulated COX-2 induced a greater ability of DGF to produce PGE2, and that these phenomena may be responsible for the severer periodontal disease in DS patients.     

Identification and characterization of mouse Ppfia1 gene in silico

Array CGH combined with mRNA microarray analyses was successfully applied for genome-wide screening of proto-oncogenes and tumor suppressor genes in 2002. The CCND1-ORAOV1-FGF19-FGF4-FGF3-FLJ10261-FADD-PPFIA1-EMS1 locus on human chromosome 11q13 is one of the most frequently amplified regions within the human genome. Here, we identified and characterized mouse Ppfia1 gene by using bioinformatics. Nucleotide sequence of mouse Ppfia1 cDNA was determined in silico by assembling nucleotide sequences of ESTs BY727670, CA327608, BU708520, BQ886535, and a 5'-truncated partial cDNA BC038349. Mouse Ppfia1 gene, consisting of 28 exons, was located between Fadd and Ems1 (also known as Cttn) genes on mouse chromosome 7. Mouse Ppfia1 (1201 aa) and human PPFIA1 (1202 aa), showing 95.8% total-amino-acid identity, were found to consist of MAH (myosin heavy chain tail and ATPase homologous) domain and three SAM (sterile alpha motif) domains. MAH domain is implicated in the homo- or hetero-oligomer formation through the coiled-coil interaction, while SAM domain is implicated in the interaction with other proteins. Mouse Ccnd1-Ems1 locus and human CCND1-EMS1 locus were evolutionarily conserved in the order and the orientation of genes therein. Nucleotide and amino-acid substitution rates of Ccnd1, Ppfia1 and Ems1 genes located near both ends of the Ccnd1-Ems1 locus were relatively lower than those in the middle part of the locus. This is the first report on mouse Ppfia1 gene as well as comprehensive comparison of CCND1-EMS1 locus within the human and mouse genomes.     

Inhibitory effect of estradiol-17 beta and progesterone on bactericidal activity in uteri of rabbits infected with Escherichia coli.

The influence of ovarian hormones at different estrous stages on the bactericidal activity of the uterus in rabbits was investigated. When Escherichia coli cells were inoculated in ligated uteri, the survival period of the bacteria in the uterus at the luteal phase was clearly longer than that at the follicular phase. At the luteal phase, high levels of plasma estradiol-17 beta and progesterone were detected. A luteolytic treatment with prostaglandin F2 alpha and human chorionic gonadotropin at the luteal phase lowered plasma progesterone levels and prompted bacterial clearance from the uterus. In ovariectomized rabbits, E. coli from the uterine exudates was not detected 6 days after the inoculation in both the nontreated and estradiol-17 beta-treated animals. In the progesterone-treated rabbits, the survival period of E. coli was longer than that in the nontreated and estradiol-17 beta-treated animals. When estradiol-17 beta and progesterone at the ratio of 1:100 were administered concurrently, E. coli survived for the longest period in the rabbits treated with various doses of different hormones. Formalin-killed E. coli cells were inoculated into the uterine lumen, and 4 h later the proportion of heterophils phagocytizing the bacteria dropped in the progesterone-treated rabbits and in the estradiol-17 beta- and progesterone-treated rabbits, but there was no significant difference in heterophil numbers among the rabbits treated with different hormones. The present results suggest that progesterone inhibits the bactericidal activity of the uterus and that estrogen concurrently secreted at the luteal phase promotes the inhibitory action of progesterone, although estrogen alone hardly affects the uterine defense. In addition, the lowering of the bactericidal activity of the uterus at the luteal phase may be attributable to lower activity of phagocytosis by heterophils infiltrated into the uterine lumen.     

Overexpression of monocyte chemotactic protein-1/CCL2 in beta-amyloid precursor protein transgenic mice show accelerated diffuse beta-amyloid deposition

Microglia accumulation at the site of amyloid plaques is a strong indication that microglia play a major role in Alzheimer's disease pathogenesis. However, how microglia affect amyloid-beta peptide (Abeta) deposition remains poorly understood. To address this question, we developed a novel bigenic mouse that overexpresses both amyloid precursor protein (APP) and monocyte chemotactic protein-1 (MCP-1; CCL2 in systematic nomenclature). CCL2 expression, driven by the glial fibrillary acidic protein promoter, induced mononuclear phagocyte (MP; monocyte-derived macrophage and microglial) accumulation in the brain. When APP/CCL2 transgenic mice were compared to APP mice, a fivefold increase in Abeta deposition was present despite increased MP accumulation around hippocampal and cortical amyloid plaques. Levels of full-length APP, its C-terminal fragment, and Abeta-degrading enzymes (insulin-degrading enzyme and neprilysin) in APP/CCL2 and APP mice were indistinguishable. Sodium dodecyl sulfate-insoluble Abeta (an indicator of fibrillar Abeta) was increased in APP/CCL2 mice at 5 months of age. Apolipoprotein E, which enhances Abeta deposition, was also increased (2.2-fold) in aged APP/CCL2 as compared to APP mice. We propose that although CCL2 stimulates MP accumulation, it increases Abeta deposition by reducing Abeta clearance through increased apolipoprotein E expression. Understanding the mechanisms underlying these events could be used to modulate microglial function in Alzheimer's disease and positively affect disease outcomes.     

FLORID DUCT LESIONS AND EXTENSIVE BILE DUCT LOSS OF THE INTRAHEPATIC BILIARY TREE IN CHRONIC LIVER DISEASES OTHER THAN PRIMARY BILIARY CIRRHOSIS

Intrahepatic biliary tree with either florid duct lesions or a moderate to severe degree of the duct loss in four livers with chronic hepatic diseases other than primary biliary cirrhosis were studied with histometric and serial section observations. Florid duct lesions, distributed segmentally in the liver, were found in one case with incomplete septal cirrhosis and one case with idiopathic portal hypertension. The florid duct lesions including marked plasma cell infiltration and occasional periductal granulomas, were not associated with any bile duct loss in the two cases. The duct lesions were reversible in one case during a long clinical course. On the other hand, a moderate to severe bile duct loss with biliary epithelial degeneration and necrosis was associated with no or little periductal inflammatory cell infiltration in one other case with chronic intrahepatic cholestasis, probably drug-induced, and in one case with idiopathic portal hypertension. Although florid duct lesions and bile duct loss were important diagnostic features of primary biliary cirrhosis, one of them was observed to develop independently in severely diseased livers, not consistent with a diagnosis of primary biliary cirrhosis, sclerosing cholangitis or intrahepatic bile duct paucity syndrome.     

Increased peripheral blood Ia positive T cells and their effect on autologous mixed lymphocyte reaction in chronic active liver disease.

We measured Ia antigen bearing peripheral blood T cells, as an index of immunological stimulation, of patients with chronic active liver diseases (CALD) by the rosette assay method. We also examined the role of Ia antigen which represents the products of the genes of the major histocompatibility complex on the autologous mixed lymphocyte reaction (AMLR) since this reaction may reflect self regulation of immune responses. The percentages of Ia positive T cells of 29 patients with CALD (17.1 +/- 4.3%, P less than 0.001) and of 12 patients with other liver diseases (12.9 +/- 2.4%, P less than 0.05) were increased when compared with that of normal individuals (10.7 +/- 2.0%). However, levels of Ia positive T cells activated by phytohaemagglutinin-P in patients with CALD and other liver diseases did not differ from normal subjects. Ia positive cells in OKT8 positive cells were markedly elevated (P less than 0.001), whereas those in OKT4 positive cells were decreased (P less than 0.01) in CALD. The impaired values for the AMLR correlated inversely (P less than 0.01) with the increased percentages of Ia positive T cells in patients with CALD. Further analysis showed that there was no suppression of the proliferation of Ia and OKT4 positive cells by Ia and OKT8 positive cells although the culture of increasing numbers of Ia and OKT8 positive cells and decreasing numbers of Ia and OKT4 positive cells gave a lesser AMLR value. These data suggest that the increase in Ia positive T cells and the alteration of Ia positive cells in the T cell subsets reflect an activation of immune system and provide further evidence in favour of an abnormality of the immunoregulatory system in CALD.     

Effects of ruthenium red on membrane ionic currents in urinary bladder smooth muscle cells of the guinea-pig

 Three major ionic currents, Ca²⁺-dependent K⁺ current (I _K-Ca), delayed rectifier type K⁺ current (I _kd) and Ca²⁺ current (I _Ca), were activated by depolarization under whole-cell clamp in single smooth muscle cells isolated from guinea-pig urinary bladder. Externally applied ruthenium red (RuR) reduced the amplitude of I _K-Ca and I _Ca at 0 mV (IC₅₀ values were 4.2 and 5.6 μM, respectively), but did not affect I _Kd. Spontaneous transient outward currents (STOCs) and caffeine-induced outward currents (I _caf) at –30 mV were reduced by external 10 μM RuR. When 10 μM RuR was added to the pipette solution, I _K-Ca during depolarization, STOCs and I _caf significantly decreased with time. RuR did not change the unitary current amplitude of the large-conductance Ca²⁺-dependent K⁺ (BK) channels, but reduced the open probability of the channel under excised patch-clamp recording mode. RuR reduced the channel activity more effectively from the cytosolic face than from the other. This inhibition decreased when the cytosolic Ca²⁺ concentration was increased. These results indicate that RuR blocks BK and Ca²⁺ channels in urinary bladder smooth muscle cells. The decrease in I _K-Ca, STOCs and I _caf by RuR is attributable to the direct inhibition of BK channel activity, probably in addition to the inhibition of Ca²⁺ release from storage sites. The direct inhibition of BK channel activity by RuR may be related to the interaction of RuR with the Ca²⁺-binding sites of the channel protein. Received: 15 October 1997 / Received after revision and accepted: 25 November 1997     

Lamivudine and IFN-beta sequential therapy in HBe antigen-positive patients with chronic hepatitis B virus genotype C infection.

Sequential treatment with lamivudine and interferon (IFN) has induced sustained biochemical and virologic responses in the majority of patients with chronic hepatitis B in France. However, the efficacy of sequential treatment in patients with chronic hepatitis B virus (HBV) genotype C infection has not been evaluated. Twenty-four HBe antigen-positive patients were treated with 100 mg lamivudine alone for 16-32 weeks, then with both 6 MU IFN-beta and lamivudine for 4 weeks, and lastly with IFN-beta alone for 20 weeks. Sustained response was achieved in 7 (29%) patients 24 weeks after the end of therapy. No lamivudine-resistant variants emerged in any patient. Hepatitis flare occurred in 3 patients after the withdrawal of lamivudine, but none had decompensation. The patients with sustained response were significantly younger at baseline (p = 0.033) and had a significantly lower HBV DNA level at the start of IFN (p = 0.020) than those without sustained response. In conclusion, the rate of response to sequential therapy with lamivudine and IFN in HBe antigen-positive patients with HBV genotype C infection was lower than the rate reported previously. Patients who were young or who had a favorable virologic response to lamivudine were more likely to have a sustained response.