Hepatitis B and circadian rhythm of the liver

The circadian rhythm in humans is determined by the central clock located in the hypothalamus’s suprachiasmatic nucleus, and it synchronizes the peripheral clocks in other tissues. Circadian clock genes and clock-controlled genes exist in almost all cell types. They have an essential role in many physiological processes, including lipid metabolism in the liver, regulation of the immune system, and the severity of infections. In addition, circadian rhythm genes can stimulate the immune response of host cells to virus infection. Hepatitis B virus (HBV) infection is the leading cause of liver disease and liver cancer globally. HBV infection depends on the host cell, and hepatocyte circadian rhythm genes are associated with HBV replication, survival, and spread. The core circadian rhythm proteins, REV-ERB and brain and muscle ARNTL-like protein 1, have a crucial role in HBV replication in hepatocytes. In addition to influencing the virus’s life cycle, the circadian rhythm also affects the pharmacokinetics and efficacy of antiviral vaccines. Therefore, it is vital to apply antiviral therapy at the appropriate time of day to reduce toxicity and improve the effectiveness of antiviral treatment. For these reasons, understanding the role of the circadian rhythm in the regulation of HBV infection and host responses to the virus provides us with a new perspective of the interplay of the circadian rhythm and anti-HBV therapy. Therefore, this review emphasizes the importance of the circadian rhythm in HBV infection and the optimization of antiviral treatment based on the circadian rhythm-dependent immune response.     

Chronic peritoneal dialysis in paediatrics: Experience of a national registry

The results of the first 3 year' collaboration of the Italian Registry of Paediatric Chronic Peritoneal Dialysis (CPD) (1986–1988) are presented. This Registry acquired data on the majority of the paediatric patients treated with CPD in Italy, thus providing a national picture in a field where few nationwide surveys are available. Patients of less than 15 years of age at the start of dialysis were enrolled and clinical data collected until the age of 19 years. The number of nephrological paediatric centres participating in the Registry increased from 7 in 1986 to 11 in 1988. The total number of patients on CPD was 70 and the percentage of dialysed children treated with CPD ranged from 40.2% to 43.6%. Data on 89 peritoneal catheters were collected: during 1417 dialysis-months 70 catheter-related complications were observed (1:20.8 dialysis-months); actuarial catheter survival was 92.7% at 6 months, 84.8% at 1 year and 68.8% at 2 years. The incidence of peritonitis changed from 1 episode every 10.9 patient-months in 1986 to 1 every 19.8 in 1988. Abdominal hernias were the other main clinical complication observed. The survival of patients was 92.5% at 3 years, while the technique survival at the same time was 84%.     

Increased in vivo frequency of IA-2 peptide-reactive IFNgamma+/IL-4- T cells in type 1 diabetic subjects

Active T cell recognition of islet antigens has been postulated as the pathogenic mechanism in human type 1 diabetes, but evidence is scarce. If T cells are engaged, they are expected to display increased clonal size and exhibit a T helper (Th)1/Th2 differentiation state. We used a peptide library that covers tyrosine phosphatase IA-2, a target antigen expressed in pancreatic beta cells, to probe 8 diabetic patients and 5 HLA-matched controls. When tested in a high resolution IFNgamma/IL-4 double color ELISPOT assay directly ex vivo, the number of IA-2-reactive IFNgamma producing cells was 17-fold higher in patients than in controls and IL-4 producing cells were not present. An average of 9 peptides was recognized in the patients vs. one in the controls. Determinant recognition primarily involved CD4+ cells and showed high variability among the patients. Furthermore, anti-CD28 antibody signal enhances quantitative assessment of effector T cells in T1D patients. In vitro expansion with peptides and IL-2 results in detection of responding cells in the controls and loss of disease specificity of the T cell response. Together these data provide strong evidence for the active targeting of IA-2 by Th1 memory effector cells in human type 1 diabetes.     

Identification and characterization of clinical isolates of members of the Staphylococcus sciuri group

A total of 28 staphylococcal isolates from human clinical specimens belonging to the Staphylococcus sciuri group were identified and characterized. The API Staph and ID32 STAPH correctly identified S. sciuri and S. lentus but not S. vitulinus strains. Identification to the subspecies level was possible only by a PCR-based method.     

T Cells Recognize Multiple GAD65 and Proinsulin Epitopes in Human Type 1 Diabetes, Suggesting Determinant Spreading

Human type 1 diabetes is thought to be mediated by autoreactive T cells specific for antigens expressed by pancreatic beta cells. However, it is unclear which autoantigens and determinants thereof are the targets of the autoimmune attack. Using comprehensive peptide libraries that cover the entire sequence of two major candidate autoantigens, GAD65 and proinsulin, we measured the in vivo frequencies of peptide-specific, IFN-gamma-producing memory T cells in 27 diabetic patients, 14 high risk individuals, and 15 partially HLA-matched healthy controls. Compared to the controls, both a higher number of determinants on the islet cell antigens were recognized and the frequencies of peptide specific cells were increased in patients and high risk individuals. Inclusion of signal enhancing anti-CD28 antibody further accentuated this difference. Considerable heterogeneity in peptide recognition was seen even in DRB1*04, DQB1*0302 matched individuals. Unlike its peptides, the GAD protein antigen did not recall a T cell memory response. The highly heterogeneous recognition of a multitude of peptide determinants on both autoantigens, occurring in the absence of protein recognition, and the low functional avidity of the memory cells involved jointly suggest that the autoimmune T cell repertoire in human type 1 diabetes primarily targets cryptic determinants engaged by determinant spreading.     

Isolation of members of the Staphylococcus sciuri group from urine and their relationship to urinary tract infections

During a 3-year study period, 32,741 urine samples were analyzed for the presence of members of the Staphylococcus sciuri group (S. sciuri, S. lentus, and S. vitulinus), and 13 isolates were identified. They presented 0.79% of the total number of coagulase-negative staphylococci isolated. One case of symptomatic urinary tract infection and five possible cases of asymptomatic bacteriuria caused by these bacteria were established. It is noteworthy, however, that over 50% of the isolates originated from hospitalized patients.     

Hirschsprung associated GDNF mutations do not prevent RET activation

Hirschsprung disease (HSCR) is a complex disorder characterised by aganglia of distal gastrointestinal tracts. The highest proportion of both familial and sporadic cases is due to mutations of the RET proto-oncogene. Five germline mutations in the glial cell-line-derived neurotrophic factor (GDNF) gene, one of the RET ligands, have been detected in HSCR patients. Pedigrees analysis and the observed association between these GDNF alterations and RET variants in the same patients raised the question of whether the GDNF gene plays any causative/predisposing role in HSCR pathogenesis. In the present work, we have studied the ability of GDNF proteins, each bearing one of the reported mutations, to activate RET by performing a functional test in cultured neuroblastoma cells. Consistently with the lack of genotype/phenotype correlation in human subjects, our results indicate absence of detectable alterations of mutant GDNF induced RET activation.     

Psychoneurodendocrine correlates of lymphocyte subsets during healthy ageing

Ageing has been associated with increased cortisol levels and absolute counts of T lymphocytes with memory phenotype. Although the mechanisms underlying these changes are still unknown, it has been speculated that this could be related to a dysfunction in FAS/CD95 expression in naive or memory cells. In this study, we investigated the role of psychoneuroendocrine variables in regulating CD95 expression on lymphocyte subsets. Forty-six elderly subjects (65-91 years) and 33 young adults (20-40 years) were recruited accordingly the SENIEUR protocol. The psychological status was measured by structured clinical interviews, salivary cortisol was assessed along the day (9, 12 and 22h) and peripheral blood lymphocytes were immunophenotyped. The elderly were more stressed, depressed and anxious than the young subjects. Cortisol levels were increased in the elderly, indicating an activation of the hypothalamic-pituitary-adrenal (HPA) axis. We observed reduced counts of CD45RA+CD95+ cells in the elderly compared to young adults. The elderly subjects also showed a reduced expression of CD3 and CD62L in contrast to increased CD95 expression in CD45RA+ cells. The emotional state was positively correlated with the lymphocyte markers. Our data suggest the healthy ageing is associated with psychoneuroendocrine alterations that may be implicated in the regulation of CD95 expression on peripheral T cells.     

Partial purification and characterization of anhydrotetracycline oxygenase of Streptomyces aureofaciens

Anhydrotetracycline oxygenase was purified both by affinity chromatography and by hydrophobic interaction chromatography. Molecular weight of anhydrotetracycline oxygenase was determined to be 115,000 by Sephadex G-200 gel filtration. Using preparative isoelectric focusing the isoelectric point of the enzyme was estimated to be 5.3. The enzyme showed a sensitivity to thiol-specific inhibitors. During the hydrophobic interaction purification step, the activity dropped considerably. Reactivation occurred when a heat treated crude extract was added to the reaction mixture.     

Supplementation with Octacosanol Affects the Level of PCSK9 and Restore Its Physiologic Relation with LDL-C in Patients on Chronic Statin Therapy

Dietary supplementation with sugar cane derivates may modulate low-density lipoprotein cholesterol (LDL-C) and proprotein convertase subtilisin/kexin type 9 (PCSK9) levels. The purpose of this study was to determine if dietary supplement (DS), containing Octacosanol (20 mg) and vitamin K2 (45 µg), could restore the disrupted physiologic relation between LDL-C and serum PCSK9. Double-blind, randomized, placebo-controlled, single-center study including 87 patients on chronic atorvastatin therapy was conducted. Eighty-seven patients were randomized to receive DS (n = 42) or placebo (n = 45), and followed for 13 weeks. Serum PCSK9 levels, lipid parameters and their relationship were the main efficacy endpoints. The absolute levels of PCSK9 and LDL-C were not significantly different from baseline to 13 weeks. However, physiologic correlation between % change of PCSK9 and % change of LDL-C levels was normalized only in the group of patients treated with DS (r = 0.409, p = 0.012). This study shows that DS can restore statin disrupted physiologic positive correlation between PCSK9 and LDL-C. Elevated PCSK9 level is an independent risk factor so controlling its rise by statins may be important in prevention of cardiovascular events.