Context-dependent differences in miR-10b breast oncogenesis can be targeted for the prevention and arrest of lymph node metastasis.

Metastases, and not the primary tumor from which they originate, are the main reason for mortality from carcinoma. Although the molecular mechanisms behind metastasis are poorly understood, it is clear that epigenetic dysregulation at the level of microRNA expression is a key characteristic of the metastatic process that can be exploited for therapy. Here, we describe an miRNA-targeted therapeutic approach for the prevention and arrest of lymph node metastasis. Therapy relies on the inhibition of the pro-metastatic microRNA-10b. It is delivered to primary and lymph node metastatic tumor cells using an imaging-capable nanodrug that is designed to specifically home to these tissues. Treatment of invasive human breast tumor cells (MDA-MB-231) with the nanodrug in vitro downregulates miR-10b and abolishes the invasion and migration of the tumor cells. After intravenous delivery to mice bearing orthotopic MDA-MB-231-luc-D3H2LN tumors, the nanodrug accumulates in the primary tumor and lymph nodes. When treatment is initiated before metastasis to lymph nodes, metastasis is prevented. Treatment after the formation of lymph node metastases arrests the metastatic process without a concomitant effect on primary tumor growth raising the possibility of a context-dependent variation in miR-10b breast oncogenesis.

Seasonal prevalence of Cryptococcus neoformans var. grubii and Cryptococcus gattii inhabiting Eucalyptus terreticornis and Eucalyptus camaldulensis trees in Jabalpur City of Madhya Pradesh, Central India.

This study presents a two-year retrospective analysis of the work done during 2003-2005 on the distribution population density and isolation frequency of Cryptococcus neoformans var. grubii and Cryptococcus gattii recovered from different parts of Eucalyptus tree spp., at Jabalpur Madhya Pradesh, Central India. Of the 1000 samples collected from bark, flowers, fruits, buds and leaves of Eucalyptus trees E. terreticornis and E. camaldulensis, 32 (3.2%) were found to be positive for C.n var. grubii and 28 (2.8%) for C. gattii respectively. While both the pathogens were isolated through all the seasons, no significant difference was found in prevalence of the two species (P>0.05) from different Eucalyptus tree samples. For C. neoformans var. grubii the highest isolation frequency of the pathogen was in spring followed by autumn, summer, winter and rainy season. For C. gattii, highest isolation frequency of the pathogen was in summer, followed by autumn, spring, winter and rainy season. Significant difference was seen in the isolation frequency of C. neoformans var. grubii and C. gattii during autumn and rainy season (P<0.01), spring and rainy season (P<0.001) and summer and rainy season (P<0.001). Population density and isolation frequency of the both pathogens were significantly lower in rainy season. Bark of the Eucalyptus tree yielded the highest frequency of C. neoformans var. grubii followed by flower, fruits, buds and debris. Trees located in the densely populated area of the city yielded highest frequency of the pathogens followed by trees located in sparsely populated area on the outskirt of the city and areas near the river Narmada. Further comprehensive study is suggested to assess the overall impact of seasonal prevalence in the isolation frequency and population density of both the pathogens and their clinical significance across climatically divergent region of India.

Monoclonal immunoglobulin G1 directed against Aspergillus fumigatus cell wall glycoprotein protects against experimental murine aspergillosis.

Most of the biological functions related to pathogenicity and virulence reside in the fungal cell wall, which, being the outermost part of the cell, mediates the host-fungus interplay. For these reasons much effort has focused on the discovery of useful inhibitors of cell wall glucan, chitin, and mannoprotein biosynthesis. In the absence of a wide-spectrum, safe, and potent antifungal agent, a new strategy for antifungal therapy is directed towards the development of monoclonal antibodies (MAbs). In the present study the MAb A9 (immunoglobulin G1 [IgG1]) was identified from hybridomas raised in BALB/c mice immunized with cell wall antigen of Aspergillus fumigatus. The immunoreactive epitopes for this IgG1 MAb appeared to be associated with a peptide moiety, and indirect immunofluorescence microscopy revealed its binding to the cell wall surface of hyphae as well as with swollen conidia. MAb A9 inhibited hyphal development as observed by MTT [3-(4,5-dimethythiazol-2-yl)-2,5-diphenyltetrazolium bromide] assay (25.76%), reduced the duration of spore germination, and exerted an in vitro cidal effect against Aspergillus fumigatus. The in vivo protective efficacy of MAb A9 was also evaluated in a murine model of invasive aspergillosis, where a reduction in CFU (>4 log(10) units) was observed in kidney tissue of BALB/c mice challenged with A. fumigatus (2 x 10(5) CFU/ml) and where enhanced mean survival times (19.5 days) compared to the control (7.1 days) and an irrelevant MAb (6.1 days) were also observed.

Immunolocalization of secretory proteins of Aspergillus fumigatus using monospecific polyclonal antibodies in a murine model.

The incidence of life-threatening mycoses caused by opportunistic fungi has increased dramatically in recent years with members of the genera Candida and Aspergillus being the most commonly encountered species. Prompt initiation of antifungal therapy for good prognosis of such cases is highly dependent on accurate diagnosis. The potential of metabolic antigens in the diagnosis of aspergillosis was investigated in the present study. Two proteins of 18 and 70 kDa were identified with success rate of 35% and 60% respectively based on their reactivity with patient sera of clinically diagnosed cases of aspergillosis. The antibodies raised against 70 and 18 kDa proteins in rabbits were found to be useful in detection of A. fumigatus in the kidneys of a mouse model of aspergillosis.

Identification of novel antifungal nonapeptides through the screening of combinatorial peptide libraries based on a hexapeptide motif.

Four sets of mixture based nonapeptide libraries derived from an antifungal hexapeptide pharmacophore Arg-D-Trp-D-Phe-Ile-D-Phe-His-NH(2) (II) have been synthesized. The three C-terminal positions 7, 8 and 9 were subject to randomization using 19 genetically coded amino acids. They were then screened for their antifungal activity against Candida albicans and Cryptococcus neoformans in order to quantify inhibition at each step of the nonapeptide sublibrary deconvolution. The studies led to the identification of several novel nonapeptides with potent antifungal activity. Two of the nonapeptides exhibited approximately 17-fold increase in the activity in comparison to the lead hexapeptide motif His-D-Trp-D-Phe-Phe-D-Phe-Lys-NH(2) (I) against C. albicans.

A clinical algorithm for the diagnosis of malaria: results of an evaluation in an area of low endemicity.

We conducted a study of 1945 children and 2885 adults who presented with fever to a hospital outpatients clinic in an urban area of India order to develop and evaluate a clinical algorithm for the diagnosis of malaria. Only 139 (7%) children and 349 (12%) adults had microscopically confirmed malaria. None of the symptoms or signs elicited from the respondents were good predictors of clinical malaria. Simple scores were derived through combining clinical features which were associated with slide positivity or were judged by clinicians to be important. The best-performing algorithms were a score of 4 clinical features in children (sensitivity 60.0% and specificity 61.2%) and a score of 5 in adults (sensitivity 54.6% and specificity 57.5%). The clinical features differed and algorithm performances were poorer than in previous studies in highly endemic areas. The conclusion is that malaria diagnosis in areas of low endemicity requires microscopy to be accurate.