The humoral immune response to the inactivated influenza A (H1N1) 2009 monovalent vaccine in patients with Type 2 diabetes mellitus in Korea

AIMS

We evaluated the antibody response to a single-dose adjuvanted, inactivated, pandemic H1N1 influenza vaccination in patients with diabetes and assessed factors associated with the failure to induce antibody responses.

METHODS

Eighty-two patients with Type 2 diabetes were vaccinated and antibody responses were determined with haemagglutination inhibition assay and anti-haemagglutinin antibody ELISA.

RESULTS

Among 70 antibody-negative patients at baseline, 34 (48.6%) achieved seroconversion; 28 (60.9%) in the young adults group and six (25%) in the elderly group acquired H1N1-specific antibodies. Patients in the older age range or with longer duration of diabetes had a lower seroconversion rate.

CONCLUSIONS

Our data show low cross-reactive antibody carrying rate and low seroconversion rate in patients with diabetes. Until larger-scale, case-controlled trials become available, older patients and patients with a longer duration of diabetes should be considered for the two-dose vaccination or have antibody titres measured after the first vaccination.

Canal and isthmus debridement efficacies of two irrigant agitation techniques in a closed system

AIM

To compare canal and isthmus debris debridement efficacies of the manual dynamic irrigation (MDI) and apical negative pressure (ANP) techniques in the mesial root of mandibular first molars with narrow isthmi, using a closed canal design.

METHODOLOGY

Micro-computed tomography was employed to select 20 teeth, each containing a narrow isthmus. Each root was sealed at the apex with hot glue and embedded in polyvinylsiloxane to simulate a closed canal system. The teeth were submitted to a standardized instrumentation protocol. Final irrigation was performed with either the MDI or the ANP technique using the EndoVac system (N=10). Masson trichrome-stained sections were prepared from completely demineralized roots at 10 canal levels between 1 and 2.8mm of the anatomical apices. Areas occupied by canals and isthmus of each root and debris in the corresponding regions were digitized by the NIH Image J software and statistically analysed using two-way repeated measures anova.

RESULTS

For the instrumented canals, there were no differences between the two groups (P=0.131) in the area occupied by debris at all canal levels (P=0.343). Conversely, for the isthmus, less debris was found in the ANP group (P<0.001) but no differences were seen in each group with respect to the 10 canal levels (P=0.352).

CONCLUSION

Neither technique completely removed debris from the isthmus regions. However, the EndoVac system, which encompasses the ANP concept, removed considerably more debris from narrow isthmi in mandibular mesial roots.

Tuberculosis in asymptomatic HIV-infected adults with abnormal chest radiographs screened for tuberculosis prevention

BACKGROUND

Isoniazid preventive therapy (IPT) prevents tuberculosis (TB) in people living with HIV (human immunodeficiency virus, PLWH). Symptom screening without chest radiographs (CXRs) was established as the strategy for excluding TB disease among PLWH seeking IPT in Botswana's 2001 pilot project. This strategy was evaluated in 2004-2006 among candidates screened for an IPT clinical trial.

METHODS

PLWH referred from clinics and HIV testing centers were screened for TB symptoms. All asymptomatic candidates received CXRs; those with abnormal CXRs were investigated further.

RESULTS

Among 2732 asymptomatic candidates screened, 302 (11%) had abnormal CXRs potentially compatible with TB; TB disease was diagnosed in 43 of these 302 (14%), or 43 (1.6%) of the 2732 asymptomatic candidates. While not associated with CD4 lymphocyte counts < 200 cells/mm(3), TB was associated with a positive tuberculin skin test (relative risk 2.1, 95%CI 1.1-4.0). IPT was initiated in 113 (62%) of 182 asymptomatic PLWH with abnormal CXRs; 8/113 (7%) subsequently developed TB, and 7/8 (88%) successfully completed anti-tuberculosis treatment.

CONCLUSIONS

The prevalences of abnormal CXRs and TB were respectively 2.6- and 8.9-fold higher among asymptomatic PLWH screened for the trial than in the pilot. A cost-effectiveness analysis is needed to determine whether the benefits of symptom screening alone are offset by the risk of inducing INH resistance by excluding CXRs during screening.

Cytokine stimulation of energy expenditure through p38 MAP kinase activation of PPARgamma coactivator-1

Cachexia is a chronic state of negative energy balance and muscle wasting that is a severe complication of cancer and chronic infection. While cytokines such as IL-1alpha, IL-1beta, and TNFalpha can mediate cachectic states, how these molecules affect energy expenditure is unknown. We show here that many cytokines activate the transcriptional PPAR gamma coactivator-1 (PGC-1) through phosphorylation by p38 kinase, resulting in stabilization and activation of PGC-1 protein. Cytokine or lipopolysaccharide (LPS)-induced activation of PGC-1 in cultured muscle cells or muscle in vivo causes increased respiration and expression of genes linked to mitochondrial uncoupling and energy expenditure. These data illustrate a direct thermogenic action of cytokines and p38 MAP kinase through the transcriptional coactivator PGC-1.

Control of hepatic gluconeogenesis through the transcriptional coactivator PGC-1

Blood glucose levels are maintained by the balance between glucose uptake by peripheral tissues and glucose secretion by the liver. Gluconeogenesis is strongly stimulated during fasting and is aberrantly activated in diabetes mellitus. Here we show that the transcriptional coactivator PGC-1 is strongly induced in liver in fasting mice and in three mouse models of insulin action deficiency: streptozotocin-induced diabetes, ob/ob genotype and liver insulin-receptor knockout. PGC-1 is induced synergistically in primary liver cultures by cyclic AMP and glucocorticoids. Adenoviral-mediated expression of PGC-1 in hepatocytes in culture or in vivo strongly activates an entire programme of key gluconeogenic enzymes, including phosphoenolpyruvate carboxykinase (PEPCK) and glucose-6-phosphatase, leading to increased glucose output. Full transcriptional activation of the PEPCK promoter requires coactivation of the glucocorticoid receptor and the liver-enriched transcription factor HNF-4alpha (hepatic nuclear factor-4alpha) by PGC-1. These results implicate PGC-1 as a key modulator of hepatic gluconeogenesis and as a central target of the insulin-cAMP axis in liver.

Peroxisome proliferator-activated receptor gamma target gene encoding a novel angiopoietin-related protein associated with adipose differentiation

The nuclear receptor peroxisome proliferator-activated receptor gamma regulates adipose differentiation and systemic insulin signaling via ligand-dependent transcriptional activation of target genes. However, the identities of the biologically relevant target genes are largely unknown. Here we describe the isolation and characterization of a novel target gene induced by PPARgamma ligands, termed PGAR (for PPARgamma angiopoietin related), which encodes a novel member of the angiopoietin family of secreted proteins. The transcriptional induction of PGAR follows a rapid time course typical of immediate-early genes and occurs in the absence of protein synthesis. The expression of PGAR is predominantly localized to adipose tissues and placenta and is consistently elevated in genetic models of obesity. Hormone-dependent adipocyte differentiation coincides with a dramatic early induction of the PGAR transcript. Alterations in nutrition and leptin administration are found to modulate the PGAR expression in vivo. Taken together, these data suggest a possible role for PGAR in the regulation of systemic lipid metabolism or glucose homeostasis.