Effects of hydrofluoroalkane and dry powder-formulated corticosteroids on sputum inflammatory markers in asthmatic patients

BACKGROUND

Inhaled corticosteroids are powerful drugs that can suppress airway inflammation in asthmatic patients. Deposition of most of the inhaled corticosteroid occurs mainly in the central airways. However, a new hydrofluoroalkane formulation of beclomethasone dipropionate (HFA-BDP) is preferentially deposited in the distal airways. Inflammatory characteristics of induced sputum have been shown to differ in samples collected early after sputum induction compared with later.

OBJECTIVE

To compare the effects of HFA-BDP and budesonide in a dry powder inhaler (DPI-BUD) on inflammatory cells and inflammatory cytokine expression in early and late induced sputa compared with placebo.

METHODS

Seventeen patients with mild, intermittent bronchial asthma were randomly assigned to two treatment groups: eight patients received HFA-BDP and nine patients received DPI-BUD. Each patient was treated with one of the active treatments and placebo (for four weeks), with a two-week washout interval in between. Inflammatory cells and expression of interleukin (IL)-4 and IL-5 were measured in early and late induced sputa before and after active treatment, as well as before and after placebo treatment using immunocytochemistry and in situ hybridization.

RESULTS

Compared with placebo, eosinophils were significantly reduced in both early and late induced sputa after HFA-BDP treatment (P<0.05), whereas DPI-BUD had a significant effect only on early induced sputum. Both HFA-BDP and DPI-BUD decreased IL-4 expression in early and late induced sputa, but the effect was more prominent with HFA-BDP. IL-5 expression was reduced in both early and late induced sputa after HFA-BDP treatment. DPI-BUD significantly decreased IL-5 expression in early but not in late induced sputum. The number of lymphocytes was not altered by either treatment.

CONCLUSIONS

HFA-BDP reduced eosinophilic inflammation and T helper 2-type cytokine expression in both early and late induced sputa, whereas the effect of DPI-BUD on inflammation was predominantly demonstrated in early induced sputum.     

Ex vivo detection of adenovirus specific CD4 T-cell responses to HLA-DR-epitopes of the Hexon protein show a contracted specificity of THELPER cells following stem cell transplantation

Human adenovirus (HAdV) is a cause of significant morbidity and mortality in immunocompromised patients, especially after stem cell transplantation (SCT). Viral clearance has been attributed to CD4⁺ T-cell responses against the Hexon-protein, but the frequency of specific T_HELPER cells is extremely low or not detectable ex vivo and preference for different CD4⁺ T-cell epitopes is variable among individuals. We therefore analyzed 44 healthy donors and 6 SCT-recipients for Hexon-specific CD4⁺-responses ex vivo, to identify epitopes which would be broadly applicable. We selected 19 candidate epitopes with predicted restriction to HLA-DR1/DR3/DR4/DR7; 16 were located within the highly conserved regions, indicating cross-reactivity of T cells among HAdV-subspecies. Ten epitopes induced CD4⁺-proliferation in >50% of individuals, confirmed by intracellular IFN-γ detection. Three SCT recipients who recovered from an infection with HAdV displayed reactivity towards only a single hexon epitope, whereas healthy individuals were responsive to two to eight epitopes (median 3). The ex vivo detection of Hexon-specific CD4⁺ T-cells, without any long-term culture in vitro, enables the detection and generation of HAdV-specific CD4⁺ T cells for adoptive T-cell transfer against HAdV-infection post SCT.     

Recreational physical activity and risk of postmenopausal breast cancer based on hormone receptor status

BACKGROUND: Physical activity is a potentially modifiable breast cancer risk factor. There is considerable recent evidence to suggest that risk factors for breast cancer differ based on its subtype, particularly estrogen receptor (ER)/progesterone receptor (PR) status, but this has been less well studied for physical activity. The objective of this study was to examine the association of physical activity with breast cancer incidence based on ER/PR status of the tumor. METHODS: The Iowa Women's Health Study is a prospective cohort study of 41 836 postmenopausal women. Recreational physical activity was self-reported on the baseline questionnaire, and 3 levels (high, medium, and low) were defined. Breast cancer incidence and ER/PR status, through 18 years of follow-up, were ascertained by linkage with the Iowa Surveillance, Epidemiology, and End Results Cancer Registry. Cox proportional hazards models were used to estimate multivariate relative risks (RRs) and 95% confidence intervals (CIs) of breast cancer, adjusting for other breast cancer risk factors. RESULTS: During 554 819 person-years of follow-up, 2548 incident cases of breast cancer were observed. Compared with low physical activity, high physical activity levels were inversely associated with risk of breast cancer (RR, 0.86; 95% CI, 0.78-0.96), and there were inverse associations for ER-positive (ER+)/PR-positive (RR, 0.87; 95% CI, 0.75-1.00), ER+/PR-negative (PR-) (RR, 0.67; 95% CI, 0.47-0.96), and ER-negative/PR- (RR, 0.80; 95% CI, 0.56-1.14) tumors. Further adjustment for body mass index attenuated the overall association with breast cancer (RR, 0.91; 95% CI, 0.82-1.01) and for ER+/PR-positive tumors (RR, 0.94; 95% CI, 0.81-1.08), while there was no change for ER+/PR- tumors (RR, 0.66; 95% CI, 0.46-0.94). CONCLUSIONS: Higher recreational physical activity might reduce the risk of postmenopausal breast cancer overall. Risk reduction varies by ER/PR status of the tumor, being most marked for ER+/PR- tumors, which, in general, have been associated with a clinically more aggressive tumor phenotype. If confirmed in additional studies, these results would suggest that additional mechanisms, besides an effect on body mass, may account for observed protective effects of physical activity in reducing breast cancer.     

A New Exact Test for the Evaluation of Population Pharmacokinetic and/or Pharmacodynamic Models Using Random Projections

Purpose  

Within-subject dependency of observations has a strong impact on the evaluation of population pharmacokinetic (PK) and/or pharmacodynamic (PD) models. To our knowledge, none of the current model evaluation tools correctly address this issue. We present a new method with a global test and easy diagnostic plot which relies on the use of a random projection technique that allows the analysis of dependent data.     

Structure-based design of potent and selective 3-phosphoinositide-dependent kinase-1 (PDK1) inhibitors

Phosphoinositide-dependent protein kinase-1(PDK1) is a master regulator of the AGC family of kinases and an integral component of the PI3K/AKT/mTOR pathway. As this pathway is among the most commonly deregulated across all cancers, a selective inhibitor of PDK1 might have utility as an anticancer agent. Herein we describe our lead optimization of compound 1 toward highly potent and selective PDK1 inhibitors via a structure-based design strategy. The most potent and selective inhibitors demonstrated submicromolar activity as measured by inhibition of phosphorylation of PDK1 substrates as well as antiproliferative activity against a subset of AML cell lines. In addition, reduction of phosphorylation of PDK1 substrates was demonstrated in vivo in mice bearing OCl-AML2 xenografts. These observations demonstrate the utility of these molecules as tools to further delineate the biology of PDK1 and the potential pharmacological uses of a PDK1 inhibitor.     

Mechanisms of in-vitro-selected daptomycin-non-susceptibility in Staphylococcus aureus

Daptomycin is highly active against Staphylococcus aureus, including multidrug-resistant strains and those with reduced susceptibility to vancomycin. However, daptomycin-non-susceptible (Dap^NS) strains [minimum inhibitory concentration (MIC) >1 mg/L] have been derived clinically and in vitro. The mechanism(s) by which this occurs is incompletely understood, but existing data indicate that it is multifactorial. Dap^NS derivatives of one laboratory and three clinical strains of S. aureus produced using gradient plates were evaluated. The Dap^NS phenotype included increases in glycopeptide and nisin MICs and in some instances defective autolysis and reduced susceptibility to lysostaphin lysis. Amino acid substitutions in MprF, YycG (WalK), or both, were identified in all Dap^NS strains. Reduced cytochrome c binding and ability of daptomycin to depolarise whole cells correlated with the Dap^NS phenotype, consistent with an increase in cell surface positivity. Gene expression data revealed increased expression of vraS, one member of a two-component system involved in the regulation of cell wall biosynthesis, in three of five Dap^NS strains. The pathway to the Dap^NS phenotype is not linear, as variable genetic and phenotypic changes may result in identical increases in MICs.     

JADD Announcements for June 2010

Announcement

JADD Announcements for June 2010     

Asymptomatic Meckel’s Diverticulum in Adults: Is Diverticulectomy Indicated?

Background/Aim:

The objective of this study was to estimate the incidence of the Meckel’s diverticulum (MD) and to study its clinical profile and surgical outcome, as well as to check whether diverticulectomy is indicated for asymptomatic MD in adults.

Materials and Methods:

This is a prospective study of 1332 patients who were operated upon for acute abdomen during the period August 1999 to July 2009 in a single surgical unit. Preoperative abdominal ultrasonography and plain x-ray abdomen (erect) were done depending on the necessity. These patients were subjected to laparotomy/ appendicectomy depending on the case. A search for MD was done, and if found, surgical resection and analysis by histopathological confirmation of the resected MD were performed.

Results:

During the operation, this study detected 15 (1.13%) patients with MD. In none of these cases, preoperative diagnosis of Meckel’s diverticulitis was made. The age of the patients ranged from 18 to 68 years (mean age, 32.9 years). Out of 15 patients, 9 (60%) were males; 6 (40%) were females. Seven (46.7%) cases were symptomatic due to MD and 8 (53.3%) were asymptomatic. One patient presented with hematochezia; 2, with intestinal obstruction due to gangrene of the MD; and 4, with Meckel’s diverticulitis. One patient had duplication of (double) Meckel’s diverticulum without any inflammation in both the diverticulae. Histopathological examination of these specimens confirmed 4 cases with inflammation; 2, with gangrene; and 1, with ulcerated gastric mucosa in the MD. Among these, in 2 (13.3%) cases there was heterotopic epithelium (ulcerated gastric mucosa- 1, colonic mucosa- 1).

Conclusion:

We recommend that a search for MD in every case of appendicectomy/ laparotomy done for acute abdomen should be conducted, and if found, Meckel’s diverticulectomy or resection should be performed to avoid secondary complications arising from it.     

Imaging trait anxiety in high anxiety F344 rats: Focus on the dorsomedial prefrontal cortex

Functional magnetic resonance imaging (fMRI) has become an important method in clinical psychiatry research whereas there are still only few comparable preclinical investigations. Herein, we report that fMRI in rats can provide key information regarding brain areas underlying anxiety behavior. Perfusion as surrogate for neuronal activity was measured by means of arterial spin labeling-based fMRI in various brain areas of high anxiety F344 rats and control Sprague-Dawley rats. In one of these areas, the dorsomedial prefrontal cortex (dmPFC), c-Fos labeling was compared between these two strains with immunolabeling. The effects of a neurotoxic ibotenic acid lesion of the dmPFC in F344 rats were examined in a social approach-avoidance anxiety procedure and fMRI. Regional brain activity of high anxiety F344 rats was different in selective cortical and subcortical areas as compared to that of low anxiety Sprague-Dawley rats; the largest difference (i.e. hyperactivity) was measured in the dmPFC. Independently, c-Fos labeling confirmed that F344 rats show increased dmPFC activity. The functional role was confirmed by neurotoxic lesion of the dmPFC that reversed the high anxiety-like behavior and partially normalized the brain activity pattern of F344 rats. The current findings may have translational value as increased activity is reported in an equivalent cortical area in patients with social anxiety, suggesting that pharmacological or functional inhibition of activity in this brain area should be explored to alleviate social anxiety in patients.     

Synthesis and characterization of novel 2-amino-3-benzoylthiophene derivatives as biased allosteric agonists and modulators of the adenosine A(1) receptor

A series of novel 2-amino-3-benzoylthiophenes (2A3BTs) were screened using a functional assay of A(1)R mediated phosphorylation of extracellular signal-regulated kinases 1 and 2 (ERK1/2) in intact CHO cells to identify potential agonistic effects as well as the ability to allosterically modulate the activity of the orthosteric agonist, R-PIA. Two derivatives, 8h and 8i, differing only in terms of the absence or presence of an electron-withdrawing group on the benzoyl moiety of the 2A3BT scaffold, were identified as biased allosteric agonists and positive allosteric modulators of agonist function at the adenosine A(1) receptor (A(1)R) in two different functional assays. Our findings indicate that subtle structural variations can promote functionally distinct receptor conformational states.