Therapeutic inertia amongst general practitioners with interest in diabetes.

INTRODUCTION: As the therapeutic options in the management of type 2 diabetes increase, there is an increase confusion among health care professionals, thus leading to the phenomenon of therapeutic inertia. This is the failure to escalate or de-escalate treatment when the clinical need for this is required. It has been studied extensively in various settings, however, it has never been reported in any studies focusing solely on primary care physicians with an interest in diabetes. This group is increasingly becoming the focus of managing complex diabetes care in the community, albeit with the support from specialists. METHODS: In this retrospective audit, we assessed the prevalence of the phenomenon of therapeutic inertia amongst primary care physicians with an interest in diabetes in UK. We also assessed the predictive abilities of various patient level characteristics on therapeutic inertia amongst this group of clinicians. RESULTS: Out of the 240 patients reported on, therapeutic inertia was judged to have occurred in 53 (22.1%) of patients. The full model containing all the selected variables was not statistically significant, p=0.59. So the model was not able to distinguish between situations in which therapeutic inertia occurred and when it did not occur. None of the patient level characteristics on its own was predictive of therapeutic inertia. CONCLUSION: Therapeutic inertia was present only in about a fifth of patient patients with diabetes being managed by primary care physicians with an interest in diabetes.

A novel mechanism linking memory stem cells with innate immunity in protection against HIV-1 infection.

HIV infection affects 37 million people and about 1.7 million are infected annually. Among the phase III clinical trials only the RV144 vaccine trial elicited significant protection against HIV-1 acquisition, but the efficacy and immune memory were inadequate. To boost these vaccine functions we studied T stem cell memory (TSCM) and innate immunity. TSCM cells were identified by phenotypic markers of CD4+ T cells and they were further characterised into 4 subsets. These expressed the common IL-2/IL-15 receptors and another subset of APOBEC3G anti-viral restriction factors, both of which were upregulated. In contrast, CD4+ TSCM cells expressing CCR5 co-receptors and α4ß7 mucosal homing integrins were decreased. A parallel increase in CD4+ T cells was recorded with IL-15 receptors, APOBEC3G and CC chemokines, the latter downmodulating CCR5 molecules. We suggest a novel mechanism of dual memory stem cells; the established sequential memory pathway, TSCM →Central →Effector memory CD4+ T cells and the innate pathway consisting of the 4 subsets of TSCM. Both pathways are likely to be activated by endogenous HSP70. The TSCM memory stem cell and innate immunity pathways have to be optimised to boost the efficacy and immune memory of protection against HIV-1 in the clinical trial.

The Effect of Cellular Stress on T and B Cell Memory Pathways in Immunized and Unimmunized BALB/c Mice.

Immunological memory is a fundamental function of vaccination. The antigenic breakdown products of the vaccine may not persist, and undefined tonic stimulation has been proposed to maintain the specific memory. We have suggested that cellular stress agents to which the immune cells are constantly exposed may be responsible for tonic stimulation. Here we have studied four stress agents: sodium arsenite, an oxidative agent; Gramicidin, eliciting K(+) efflux and calcium influx; dithiocarbamate, a metal ionophore; and aluminum hydroxide (alum), an immunological adjuvant. The aims of this study are to extend these investigations to T and B cell responses of unimmunized and ovalbumin (OVA)-immunized BALB/c mice, and furthermore, to ascertain whether stress is involved in optimal expression of memory B cells, as demonstrated in CD4(+) T cells. Examination of the homeostatic pathway defined by IL-15/IL-15R (IL-15 receptor) interaction and the inflammasome pathway defined by the IL-1-IL-1R interaction between dendritic cells (DC) and CD4(+) T cells suggests that both pathways are involved in the development of optimal expression of CD4(+)CD45RO(+) memory T cells in unimmunized and OVA-immunized BALB/c mice. Furthermore, significant direct correlation was found between CD4(+)CD44(+) memory T cells and both IL-15 of the homeostatic and IL-1ß of the inflammasome pathways. However, CD19(+)CD27(+) memory B cells in vivo seem to utilize only the IL-15/IL-15R homeostatic pathway, although the proliferative responses are enhanced by the stress agents. Altogether, stress agents may up-regulate unimmunized and OVA-immunized CD4(+)CD44(+) memory T cells by the homeostatic and inflammasome pathways. However, the CD19(+)CD27(+) memory B cells utilize only the homeostatic pathway.

Murine model of concurrent oral and vaginal Candida albicans colonisation.

Investigations into the complex interaction between the fungal pathogen Candida albicans and its human host require the use of animals as in vivo models. A major advance is the creation of a low-oestrogen murine model of concurrent oral and vaginal C. albicans colonisation that resembles human candidal carriage at both mucosal sites. Weekly intramuscular (5 µg) and subcutaneous (5 µg) oestrogen administration was determined as optimal, enhancing oral colonisation but essential for vaginal colonisation. Using a clinical C. albicans oral isolate, persistent colonisation for up to 6 weeks can be achieved at both sites in two strains of mice (BALB/c and C57BL/6). This concurrent model of mucosal colonisation reduces the numbers of experimental mice by half, and opens up new avenues of research in assessing potential mucosal vaccine candidates and in studying delicate host-pathogen interactions during the most natural state of C. albicans epithelial colonisation.

Murine model of concurrent oral and vaginal Candida albicans colonization to study epithelial host-pathogen interactions.

We report the creation of a new low-estrogen murine model of concurrent oral and vaginal C. albicans colonization that resembles human candidal carriage at both mucosal sites. Weekly estrogen administration of 5 microg intramuscular and subcutaneously was optimal for enhancement of oral colonization and was essential for vaginal colonization. In BALB/c mice, a number of C. albicans clinical isolates (n=3) colonized both oral and/or vaginal sites, but only strain 529L colonized 100% of mice persistently for over 5 weeks. Laboratory strains SC5314 and NCPF 3153 did not colonize the model; however, NCPF 3156 showed vaginal colonization up to week 5. Prior passaging through mice enhanced subsequent colonization of SC5314. Intranasal immunization with a C. albicans virulence antigen (secreted aspartyl proteinase 2) significantly reduced or abolished the fungal burden orally and vaginally by week 2 and 7. Our concurrent model of mucosal colonization reduces the numbers of experimental mice by half, can be used to assess potential vaccine candidates, and permits the detailed analysis of host-fungal interactions during the natural state of Candida colonization.

Serum and saliva antibodies do not inhibit Candida albicans Sap2 proteinase activity using a BSA hydrolysis assay.

The opportunistic fungal pathogen Candida albicans possesses 10 members of a secreted aspartyl proteinase (Sap) family, which are associated with fungal virulence. The C. albicans proteinases are known to induce antibody responses in humans, but the direct inhibition of Sap activity by antibody has not yet been demonstrated. The aim of this study was to determine whether antibodies in saliva or serum could inhibit C. albicans proteinase activity. A two-step Sap-inhibition assay based on bovine serum albumin (BSA) hydrolysis was developed. First, serum and saliva were incubated with Sap2 to allow antibodies to bind to the enzyme, and then a Sap activity assay was performed to determine whether or not the bound antibodies were capable of inhibiting Sap activity. Inhibition of Sap2 activity was investigated using nine sources of sera or saliva: mouse Sap1, Sap2 and Sap3 antisera; rabbit Sap2 antiserum; two pooled human serum samples from HIV-positive and HIV-negative patients with oral C. albicans infection; and three pooled saliva samples from patients with oral C. albicans infection, C. albicans carriers, and Candida-culture-negative individuals. Pooled saliva samples did not inhibit Sap2 activity, whereas mouse, rabbit, and human sera demonstrated inhibition of Sap2 activity by 20-45%. Further analysis of different serum fractions, purified total IgG, and Sap2-specific antibodies demonstrated that non-protein, non-antibody components of serum appeared to be responsible for the partial inhibition of Sap2 activity. Therefore, no evidence was found to demonstrate that specific or non-specific antibodies in serum or saliva could inhibit C. albicans Sap2 activity.