Invasive aspergillosis in patients with hematologic malignancies: incidence and description of 127 cases enrolled in a single institution prospective survey from 2004 to 2009.

BACKGROUND: The study objectives were: 1) to report on invasive aspergillosis patients in a hematology department; and 2) to estimate its incidence according to the hematologic diagnosis. DESIGN AND METHODS: A prospective survey of invasive aspergillosis cases was undertaken between January 2004 and December 2009 in the hematology department of a university hospital. Meetings with clinicians, mycologists and infection control practitioners were organized monthly to confirm suspected aspergillosis cases. Demographic characteristics, clinical and complementary examination results were recorded prospectively. Information on hospitalization was extracted from administrative databases. Invasive aspergillosis diagnosis followed the European Organization for Research and Treatment of Cancer criteria, and proven and probable IA cases were retained. A descriptive analysis was conducted with temporal trends of invasive aspergillosis incidence assessed by adjusted Poisson regression. RESULTS: Overall, 4,073 hospitalized patients (78,360 patient-days) were included in the study. In total, 127 (3.1%) patients presented invasive aspergillosis. The overall incidence was 1.6 per 1,000 patient-days (95% confidence interval: 1.4, 1.9) with a decrease of 16% per year (-1%, -28%). The incidence was 1.9 per 1,000 patient-days (1.5, 2.3) in acute myeloid leukemia patients with a decrease of 20% per year (-6%, -36%). Serum Aspergillus antigen was detected in 89 (71%) patients; 29 (23%) had positive cultures, and 118 (93%), abnormal lung CT scans. One-month mortality was 13%; 3-month mortality was 42%. Mortality tended to decrease between 2004 and 2009. CONCLUSIONS: Invasive aspergillosis incidence and mortality declined between 2004 and 2009. Knowledge of invasive aspergillosis characteristics and its clinical course should help to improve the management of these patients with severe disease.

A short upstream promoter region mediates transcriptional regulation of the mouse doublecortin gene in differentiating neurons.

BACKGROUND: Doublecortin (Dcx), a MAP (Microtubule-Associated Protein), is transiently expressed in migrating and differentiating neurons and thereby characterizes neuronal precursors and neurogenesis in developing and adult neurogenesis. In addition, reduced Dcx expression during development has been related to appearance of brain pathologies. Here, we attempt to unveil the molecular mechanisms controlling Dcx gene expression by studying its transcriptional regulation during neuronal differentiation. RESULTS: To determine and analyze important regulatory sequences of the Dcx promoter, we studied a putative regulatory region upstream from the mouse Dcx coding region (pdcx2kb) and several deletions thereof. These different fragments were used in vitro and in vivo to drive reporter gene expression. We demonstrated, using transient expression experiments, that pdcx2kb is sufficient to control specific reporter gene expression in cerebellar cells and in the developing brain (E14.5). We determined the temporal profile of Dcx promoter activity during neuronal differentiation of mouse embryonic stem cells (mESC) and found that transcriptional activation of the Dcx gene varies along with neuronal differentiation of mESC. Deletion experiments and sequence comparison of Dcx promoters across rodents, human and chicken revealed the importance of a highly conserved sequence in the proximal region of the promoter required for specific and strong expression in neuronal precursors and young neuronal cells. Further analyses revealed the presence in this short sequence of several conserved, putative transcription factor binding sites: LEF/TCF (Lymphoid Enhancer Factor/T-Cell Factor) which are effectors of the canonical Wnt pathway; HNF6/OC2 (Hepatocyte Nuclear Factor-6/Oncecut-2) members of the ONECUT family and NF-Y/CAAT (Nuclear Factor-Y). CONCLUSIONS: Studies of Dcx gene regulatory sequences using native, deleted and mutated constructs suggest that fragments located upstream of the Dcx coding sequence are sufficient to induce specific Dcx expression in vitro: in heterogeneous differentiated neurons from mESC, in primary mouse cerebellar neurons (PND3) and in organotypic slice cultures. Furthermore, a region in the 3'-end region of the Dcx promoter is highly conserved across several species and exerts positive control on Dcx transcriptional activation. Together, these results indicate that the proximal 3'-end region of the mouse Dcx regulatory sequence is essential for Dcx gene expression during differentiation of neuronal precursors.

Expression of Id and ITF-2 genes in the mammary gland during pregnancy.

Id-1 is one of the four related helix-loop-helix Id proteins that act as inhibitors of the basic helix-loop-helix (bHLH) transcription factors that control cell differentiation, development and carcinogenesis. We previously found that Id-1 regulated the growth, differentiation, apoptosis and invasion of mouse mammary epithelial cells in culture. Using the techniques of immunohistochemistry and in situ hybridization, we now show that Id-1 gene expression is specifically detected in the epithelial cells of growing ductal structures during early pregnancy. Using adjacent sections, we determined that Id-1 was expressed in keratin 8/18 positive cells. We also demonstrated that the up-regulation of Id-2 during late pregnancy correlated with the down-regulation of Id-1. Using the yeast-two hybrid system, we identified the bHLH transcription factors, ITF-2A and ITF-2B, as the Id-interacting proteins. The levels of expression of these two splice variants did not change during the transition from growing ductal structures to differentiated alveoli. Therefore Id-1 and Id-2, but not the ubiquitous bHLH proteins, appear to represent the key factors whose expression is modulated during different stages of pregnancy in mouse mammary glands.

Invasive aspergillosis in a paediatric haematology department: a 15-year review.

Invasive aspergillosis (IA) is an increasingly common and often fatal fungal infection in children with haematological disorders. To describe the epidemiology, diagnosis, treatment and outcome of IA in children, retrospective review of the medical records of proven and probable IA between January 1986 and December 2000 was used. Twenty-four patients with IA were identified (10 proven and 14 probable) with a median age of 8.5 years. The incidence of IA was particularly high in acute myeloblastic leukaemia (5.35%) and leukaemia relapse (4%). Twenty-two patients presented with lung involvement. Broncho-alveolar lavage led to a diagnosis in 11 cases, but diagnosis was difficult and repeated invasive explorations were required. Antifungal therapy mainly consisted of amphotericin B. Eight patients underwent open-thorax surgery without any complication. Nine patients (37.5%) were cured of IA and three are still alive. The mortality was 87.5%. Three patients died of massive haemoptysis, including two before neutropenia recovery. Four patients presented with IA recurrence and three were cured again. Despite significant progress having been made in the treatment and diagnosis of IA, it is still a devastating complication in children with haematological disorders. New antifungal therapies and strategies are promising, but objective data are still lacking.

Reduction of invasive aspergillosis incidence among immunocompromised patients after control of environmental exposure.

BACKGROUND: The objective of the study was to assess the impact of the relocation of an adult hematological intensive care unit on invasive aspergillosis (IA) incidence. METHODS: A quasi-experimental study, including a control group and an intervention group that both underwent pretest and posttest evaluations, was conducted in the 3 adult hematological intensive care units (each composed of 14 single rooms) in a university hospital from 14 April 2005 through 1 February 2006. One of these units was relocated from the main building to an adjoining modular construction. In this unit, 4 rooms were equipped with laminar airflow before relocation; all rooms were equipped with positive pressure isolation after relocation. The 2 other units (control group), each containing 8 rooms with laminar airflow, did not undergo environmental modification. The diagnostic criteria for IA were based on the criteria of the European Organization for Research and Treatment of Cancer. RESULTS: In total, 356 hospitalized patients were included. Of the 21 cases of IA, 18 were nosocomial, and 3 were of undetermined origin. In the relocated unit, the incidence of IA decreased from 13.2% (9 patients) before relocation to 1.6% (1 patient) after relocation (P=.018). Eight of the 9 patients with IA before relocation stayed in rooms without specific air treatment. The rate of IA did not change in the control group. Patient characteristics were similar in each unit before and after relocation. CONCLUSION: We detected a straightforward association between environmental modification and decreased IA incidence, which emphasizes the use of an environmental strategy, including high-efficiency air filtration, in the prevention of IA.

Susceptibility testing of sequential isolates of Aspergillus fumigatus recovered from treated patients.

Two-hundred sequential Aspergillus fumigatus isolates recovered from 26 immunocompromised patients with invasive aspergillosis or bronchial colonization were tested for their in vitro susceptibility to posaconazole, itraconazole, voriconazole, terbinafine and amphotericin B. Twenty-one patients were treated with amphotericin B and/or itraconazole. Antifungal susceptibilities of the isolates recovered before treatment were not significantly different from those of isolates recovered after the onset of antifungal therapy. The highest MICs were 0.125, 0.5, 0.5, 1 and 1 microg ml(-1) for posaconazole, itraconazole, voriconazole, terbinafine and amphotericin B, respectively. It is concluded that the emergence of resistance in A. fumigatus during antifungal therapy with amphotericin B or itraconazole is an uncommon phenomenon.

Subchronic alpha-linolenic acid treatment enhances brain plasticity and exerts an antidepressant effect: a versatile potential therapy for stroke.

Omega-3 polyunsaturated fatty acids are known to have therapeutic potential in several neurological and psychiatric disorders. However, the molecular mechanisms of action underlying these effects are not well elucidated. We previously showed that alpha-linolenic acid (ALA) reduced ischemic brain damage after a single treatment. To follow-up this finding, we investigated whether subchronic ALA treatment promoted neuronal plasticity. Three sequential injections with a neuroprotective dose of ALA increased neurogenesis and expression of key proteins involved in synaptic functions, namely, synaptophysin-1, VAMP-2, and SNAP-25, as well as proteins supporting glutamatergic neurotransmission, namely, V-GLUT1 and V-GLUT2. These effects were correlated with an increase in brain-derived neurotrophic factor (BDNF) protein levels, both in vitro using neural stem cells and hippocampal cultures and in vivo, after subchronic ALA treatment. Given that BDNF has antidepressant activity, this led us to test whether subchronic ALA treatment could produce antidepressant-like behavior. ALA-treated mice had significantly reduced measures of depressive-like behavior compared with vehicle-treated animals, suggesting another aspect of ALA treatment that could stimulate functional stroke recovery by potentially combining acute neuroprotection with long-term repair/compensatory plasticity. Indeed, three sequential injections of ALA enhanced protection, either as a pretreatment, wherein it reduced post-ischemic infarct volume 24 h after a 1-hour occlusion of the middle cerebral artery or as post-treatment therapy, wherein it augmented animal survival rates by threefold 10 days after ischemia.

Regulation of clusterin expression in mammary epithelial cells.

Mammary epithelial cells undergo changes in growth, invasion, differentiation, and dedifferentiation throughout much of adult hood, and most strikingly during pregnancy, lactation, and involution. Clusterin is a multifunctional glycoprotein that is involved in the differentiation and morphogenesis of epithelia, and that is important in the regulation of postnatal mammary gland development. However, the mechanisms that regulate clusterin expression are still poorly understood. Here, we show that clusterin is up-regulated twice during mouse mammary gland development, a first time at the end of pregnancy and a second time at the beginning of the involution. These points of clusterin up-regulation coincide with the dramatic phenotypic and functional changes occurring in the mammary gland. Using cell culture conditions that resemble the regulatory microenvironment in vivo, we determined that the factors responsible for the first up-regulation of clusterin levels can include the extracellular matrix component, laminin, and the lactogenic hormones, prolactin and hydrocortisone. On the other hand, the second and most dramatic up-regulation of clusterin can be due to the potent induction by TGF-beta1, and this up-regulation by TGF-beta1 is dependent on beta1 integrin ligand-binding activity. Moreover, the level of expression of beta-casein, a marker of mammary epithelial cell differentiation, was decreased upon treatment of cells with clusterin siRNA. Overall, these findings reveal several novel pathways for the regulation of clusterin expression during mammary gland development, and suggest that clusterin is a morphogenic factor that plays a key role during differentiation.

Mitochondrial dysfunction induces triglyceride accumulation in 3T3-L1 cells: role of fatty acid beta-oxidation and glucose.

Mitochondrial cytopathy has been associated with modifications of lipid metabolism in various situations, such as the acquisition of an abnormal adipocyte phenotype observed in multiple symmetrical lipomatosis or triglyceride (TG) accumulation in muscles associated with the myoclonic epilepsy with ragged red fibers syndrome. However, the molecular signaling leading to fat metabolism dysregulation in cells with impaired mitochondrial activity is still poorly understood. Here, we found that preadipocytes incubated with inhibitors of mitochondrial respiration such as antimycin A (AA) accumulate TG vesicles but do not acquire specific markers of adipocytes. Although the uptake of TG precursors is not stimulated in 3T3-L1 cells with impaired mitochondrial activity, we found a strong stimulation of glucose uptake in AA-treated cells mediated by calcium and phosphatidylinositol 3-kinase/Akt1/glycogen synthase kinase 3beta, a pathway known to trigger the translocation of glucose transporter 4 to the plasma membrane in response to insulin. TG accumulation in AA-treated cells is mediated by a reduced peroxisome proliferator-activated receptor gamma activity that downregulates muscle carnitine palmitoyl transferase-1 expression and fatty acid beta-oxidation, and by a direct conversion of glucose into TGs accompanied by the activation of carbohydrate-responsive element binding protein, a lipogenic transcription factor. Taken together, these results could explain how mitochondrial impairment leads to the multivesicular phenotype found in some mitochondria-originating diseases associated with a dysfunction in fat metabolism.