Role of modified bleach method in staining of acid-fast bacilli in lymph node aspirates

OBJECTIVE: To correlate acid-fast bacilli (AFB) positivity with cytomorphologic patterns of tuberculous lymphadenitis and evaluate bleach concentration method in diagnosing lymph node tuberculosis compared to Ziehl-Neelsen (ZN) method. STUDY DESIGN: One hundred cases of tuberculous lymphadenitis diagnosed by fine needle aspiration cytology (FNAC) were analyzed and classified into 6 cytomorphologic patterns and correlated with bacillary load using routine and modified bleach methods of ZN staining. Smears were graded for AFB positivity. Sensitivity of routine ZN and modified bleach concentration was compared. RESULTS: The classic cytomorphologic pattern of tuberculosis showing epithelioid granulomas, Langerhans giant cells and caseous necrosis was seen in 23% of cases. Routine ZN staining detected AFB in 27% of cases and the modified bleach method in 72%. In 58 cases the modified bleach method had a higher grade of AFB positivity than the routine method. The modified bleach method did not miss any AFB positivity detected on routine ZN staining. CONCLUSION: The modified bleach method demonstrated AFB positivity in 72% of cases. AFB positivity grade was much higher than with routine ZN staining, making bacilli easily visible, with shorter screening time. The modified bleach method is inexpensive, easily performed and more sensitive and safe than routine ZN staining.     

Cytodiagnosis of granulocytic sarcoma of liver arising in a milieu of myeloid metaplasia: a case report

BACKGROUND: Granulocytic sarcoma is an extramedullary tumor that is composed of granulocytic precursor cells. We report an unusual case of granulocytic sarcoma of the liver that arose in the background of myeloid metaplasia. Fine needle aspiration cytology (FNAC) was instrumental in making the diagnosis in absence of previously known Hematlogic abnormality. CASE: A 65-year-old woman presented with multiple nodules in the liver. USG-guided FNAC was performed on them. The aspirates showed many myeloid blasts, myelocytes, metamyelocytes, erytbroid precursors and lympboglandular bodies. We considered a differential diagnosis of granulocytic sarcoma and myeloid metaplasia. The presence of erytbroid precursors prompted us to consider myeloid metaplasia as a differential diagnorsis of granulocytic sarcoma. Peripberal smear showed a leukoerytbroblastic reaction. The patient died, and necropsy from the liver revealed extensive infiltration by undfferentiated blast cells with areas of myeloid metaplasia showing maturing erytbroid, myeloid and megakaryocytic elements. CONCLUSION: When a dual population of predominant myeloid blasts and normoblarts is encountered, a suspicion of granulocytic sarcoma arising in a background of myeloid metaplasia must be kept. Cells of all 3 lineages may not be always seen in myeloid metaplasia, and 1 cell line may predominate, causing a diagnostic dilemma.     

Solution NMR studies provide structural basis for endotoxin pattern recognition by the innate immune receptor CD14

CD14 functions as a key pattern recognition receptor for a diverse array of Gram-negative and Gram-positive cell-wall components in the host innate immune response by binding to pathogen-associated molecular patterns (PAMPs) at partially overlapping binding site(s). To determine the potential contribution of CD14 residues in this pattern recognition, we have examined using solution NMR spectroscopy, the binding of three different endotoxin ligands, lipopolysaccharide, lipoteichoic acid, and a PGN-derived compound, muramyl dipeptide to a ¹⁵N isotopically labeled 152-residue N-terminal fragment of sCD14 expressed in Pichia pastoris. Mapping of NMR spectral changes upon addition of ligands revealed that the pattern of residues affected by binding of each ligand is partially similar and partially different. This first direct structural observation of the ability of specific residue combinations of CD14 to differentially affect endotoxin binding may help explain the broad specificity of CD14 in ligand recognition and provide a structural basis for pattern recognition. Another interesting finding from the observed spectral changes is that the mode of binding may be dynamically modulated and could provide a mechanism for binding endotoxins with structural diversity through a common binding site.     

IL10 Variant g.5311A Is Associated with Visceral Leishmaniasis in Indian Population

BackgroundVisceral leishmaniasis (VL) is a multifactorial disease, where the host genetics play a significant role in determining the disease outcome. The immunological role of anti-inflammatory cytokine, Interleukin 10 (IL10), has been well-documented in parasite infections and considered as a key regulatory cytokine for VL. Although VL patients in India display high level of IL10 in blood serum, no genetic study has been conducted to assess the VL susceptibility / resistance. Therefore, the aim of this study is to investigate the role of IL10 variations in Indian VL; and to estimate the distribution of disease associated allele in diverse Indian populations.MethodologyAll the exons and exon-intron boundaries of IL10 were sequenced in 184 VL patients along with 172 ethnically matched controls from VL endemic region of India.

Result and Discussion

Our analysis revealed four variations; rs1518111 (2195 A>G, intron), rs1554286 (2607 C>T, intron), rs3024496 (4976 T>C, 3’ UTR) and rs3024498 (5311 A>G, 3’ UTR). Of these, a variant g.5311A is significantly associated with VL (χ²=18.87; p =0.00001). In silico approaches have shown that a putative micro RNA binding site (miR-4321) is lost in rs3024498 mRNA. Further, analysis of the above four variations in 1138 individuals from 34 ethnic populations, representing different social and linguistic groups who are inhabited in different geographical regions of India, showed variable frequency. Interestingly, we have found, majority of the tribal populations have low frequency of VL (‘A’ of rs3024498); and high frequency of leprosy (‘T’ of rs1554286), and Behcet’s (‘A’ of rs1518111) associated alleles, whereas these were vice versa in castes. Our findings suggest that majority of tribal populations of India carry the protected / less severe allele against VL, while risk / more severe allele for leprosy and Behcet’s disease. This study has potential implications in counseling and management of VL and other infectious diseases.     

An Evolutionary Analysis of the Secoviridae Family of Viruses

The plant-infecting Secoviridae family of viruses forms part of the Picornavirales order, an important group of non-enveloped viruses that infect vertebrates, arthropods, plants and algae. The impact of the secovirids on cultivated crops is significant, infecting a wide range of plants from grapevine to rice. The overwhelming majority are transmitted by ecdysozoan vectors such as nematodes, beetles and aphids. In this study, we have applied a variety of computational methods to examine the evolutionary traits of these viruses. Strong purifying selection pressures were calculated for the coat protein (CP) sequences of nine species, although for two species evidence of both codon specific and episodic diversifying selection were found. By using Bayesian phylogenetic reconstruction methods CP nucleotide substitution rates for four species were estimated to range from between 9.29×10⁻³ to 2.74×10⁻³ (subs/site/year), values which are comparable with the short-term estimates of other related plant- and animal-infecting virus species. From these data, we were able to construct a time-measured phylogeny of the subfamily Comovirinae that estimated divergence of ninety-four extant sequences occurred less than 1,000 years ago with present virus species diversifying between 50 and 250 years ago; a period coinciding with the intensification of agricultural practices in industrial societies. Although recombination (modularity) was limited to closely related taxa, significant and often unique similarities in the protein domains between secovirid and animal infecting picorna-like viruses, especially for the protease and coat protein, suggested a shared ancestry. We discuss our results in a wider context and find tentative evidence to indicate that some members of the Secoviridae might have their origins in insects, possibly colonizing plants in a number of founding events that have led to speciation. Such a scenario; virus infection between species of different taxonomic kingdoms, has significant implications for virus emergence.     

Identification of BPESC1, a Novel Gene Disrupted by a Balanced Chromosomal Translocation, t(3;4)(q23;p15.2), in a Patient with BPES

The blepharophimosis syndrome (BPES) is a rare genetic disorder characterized by blepharophimosis, ptosis, epicanthus inversus, and telecanthus. In type I, BPES is associated with female infertility, while in type II, the eyelid defect occurs by itself. The BPES syndrome has been mapped to 3q23. Previously, we constructed a YAC-, PAC-, and cosmid-based physical map surrounding the 3q23 translocation breakpoint of a t(3;4)(q23;p15.2) BPES patient, containing a 110-kb PAC (169-C 10) and a 43-kb cosmid (11-L 10) spanning the breakpoint. In this report, we present the identification of BPESC1 (BPES candidate 1), a novel candidate gene that is disrupted by the translocation on chromosome 3. Cloning of the cDNA has been performed starting from a testis-specific EST, AI032396, found in cosmid 11-L 10. The cDNA sequence of BPESC1 is 3518 bp in size and contains an open reading frame of 351 bp. No significant similarities with known proteins have been found in the sequence databases. BPESC1 contains three exons and spans a genomic fragment of 17.5 kb. Expression of BPESC1 was observed in adult testis tissue. We performed mutation analysis in 28 unrelated familial and sporadic BPES patients, but, apart from the disruption by the translocation, found no other disease-causing mutations. These data make it unlikely that BPESC1 plays a major role in the pathogenesis of BPES.     

Effect of Homocysteine on Biofilm Formation by Mycobacteria

Mycobacteria show peculiar aggregated outgrowth like biofilm on the surface of solid or liquid media. Biofilms harbor antibiotic resistant bacteria in a self-produced extracellular matrix that signifies the bacterial fate to sedentary existence. Despite years of research, very little is known about the mechanisms that contribute to biofilm formation. LuxS has been previously known to play a role in biofilm formation in Autoinducer-2 dependent manner. We here show the effect of LuxS product-homocysteine, on the biofilm forming ability of non-tuberculous mycobacteria, Mycobacterium smegmatis and Mycobacterium bovis BCG showing AI-2 independent phenotypic effect of LuxS. Exogenous supplementation of homocysteine in the culture media leads to aberrant cording, pellicle outgrowth, and biofilm formation. Thus, our study contributes to the better understanding of the mechanism of mycobacterial biofilm formation and sheds light on the role of LuxS product homocysteine. In addition, we highlight the contribution of activated methyl cycle in bacterial quorum sensing.     

GroEL Mediates Folding of <Emphasis Type="Italic">Bacillus anthracis</Emphasis> Serine/Threonine Protein Kinase,PrkC

Bacillus anthracis causes anthrax in human and animals. Both, signaling system such as two component system and endogenous chaperone system such as GroEL–GroES help bacteria to cope with the environmental challenges. Such molecular chaperones are the stress induced proteins that help bacteria to override unfavorable conditions by their moonlighting functions. Previous reports showed that PrkC and PrpC, the Ser/Thr kinase–phosphatase pair in B. anthracis, control phosphorylation of GroEL and regulate biofilm formation. In this study, we show that GroEL is involved in the folding of PrkC to active form. The proteins (GroEL, PrkC and PrpC) were expressed and purified by affinity chromatography. Purified GroEL was used for refolding of denatured PrkC and PrpC and observed that GroEL refolds PrkC but not PrpC as measured by their enzymatic activity. We also observed that purification of GroEL with six histidine tag using Cobalt-Agarose resin yielded superior quality GroEL protein with negligible contamination of non-specific proteins. Thus, cobalt resin can be a better choice for purification of many histidine tagged proteins, where Ni-NTA does not work very well.     

Lyotropic Liquid Crystalline Nanoparticles of Amphotericin B: Implication of Phytantriol and Glyceryl Monooleate on Bioavailability Enhancement

Implication of different dietary specific lipids such as phytantriol (PT) and glyceryl monooleate (GMO) on enhancing the oral bioavailability of amphotericin B (AmB) was examined. Liquid crystalline nanoparticles (LCNPs) were prepared using hydrotrope method, followed by in vitro characterization, Caco-2 cell monolayer uptake, and in vivo pharmacokinetic and toxicity evaluation. Optimized AmB-LCNPs displayed small particle size (<?210 nm) with a narrow distribution (~?0.2), sustained drug release and high gastrointestinal stability, and reduced hemolytic toxicity. PLCNPs presented slower release, i.e., ~?80% as compared to ~?90% release in case of GLCNPs after 120 h. Significantly higher uptake in Caco-2 monolayer substantiated the role of LCNPs in increasing the intestinal permeability followed by increased drug titer in plasma. Pharmacokinetic studies demonstrated potential of PT in enhancing the bioavailability (approximately sixfold) w.r.t. of its native counterpart with reduced nephrotoxicity as presented by reduced nephrotoxicity biomarkers and histology studies. These studies established usefulness of PLCNPs over GLCNPs and plain drug. It can be concluded that acid-resistant lipid, PT, can be utilized efficiently as an alternate lipid for the preparation of LCNPs to enhance bioavailability and to reduce nephrotoxicity of the drug as compared to other frequently used lipid, i.e., GMO.