Excess NF-κB induces ectopic odontogenesis in embryonic incisor epithelium.

Nuclear factor kappa B (NF-κB) signaling plays critical roles in many physiological and pathological processes, including regulating organogenesis. Down-regulation of NF-κB signaling during development results in hypohidrotic ectodermal dysplasia. The roles of NF-κB signaling in tooth development, however, are not fully understood. We examined mice overexpressing IKKß, an essential component of the NF-κB pathway, under keratin 5 promoter (K5-Ikkß). K5-Ikkß mice showed supernumerary incisors whose formation was accompanied by up-regulation of canonical Wnt signaling. Apoptosis that is normally observed in wild-type incisor epithelium was reduced in K5-Ikkß mice. The supernumerary incisors in K5-Ikkß mice were found to phenocopy extra incisors in mice with mutations of Wnt inhibitor, Wise. Excess NF-κB activity thus induces an ectopic odontogenesis program that is usually suppressed under physiological conditions.

Cefotaximase and AmpC-producing Shigella flexneri in case of dysentery from southern India.

Diarrhoea and dysentery caused by Shigella spp. are major public health concerns. Emerging multidrug resistance (MDR) in this pathogen further complicates this disease. Extended spectrum ß-lactamases (ESBLs) have been described in this pathogen, which significantly compromises the treatment options for shigellosis. The usual ESBLs seen are sulfhydryl variable (SHV)-type; cefotaximases (CTX-M) are very uncommonly detected. Here, we report a CTX-M type and AmpC-producing Shigella flexneri from a three-year-old boy residing in Central Kerala, South India.

Integrin α9ß1 promotes malignant tumor growth and metastasis by potentiating epithelial-mesenchymal transition.

The integrin α9ß1 binds a number of extracellular matrix components to mediate cell adhesion, migration and tissue invasion. Although expressed in a variety of normal human cells including endothelium, it is also expressed in cancer cells. We have previously shown that α9ß1 binds VEGF-A to facilitate angiogenesis, an important component of the tumor microenvironment. As α9ß1 induces accelerated cancer cell migration, we wished to determine what role it played in cancer growth and metastasis. In this study, we show that α9ß1 expression induces molecular changes consistent with epithelial-mesenchymal transition. In addition, we found that α9ß1 forms a tri-partite protein complex with ß-catenin and E-cadherin, which dissociates following integrin activation and subsequent src and ß-catenin phosphorylation. These findings were consistent in cells in which: α9ß1 was exogenously over-expressed, or when its expression was suppressed in cancer cells endogenously expressing α9ß1. These in vitro results are biologically significant as α9ß1-expressing cancer cells induce greater tumor growth and metastases in mice as compared to the cells without α9ß1 expression or when integrin expression is suppressed. Furthermore, integrin α9ß1 is expressed in primary human small cell lung cancer and patients having a high expression of α9ß1 demonstrated significantly worse long-term survival compared with patients with low α9ß1 expression. These findings highlight a novel mechanism of integrin α9ß1 function in human cancer.

Oral lining mucosa development depends on mesenchymal microRNAs.

The oral mucosa plays critical roles in protection, sensation, and secretion and can be classified into masticatory, lining, and specialized mucosa that are known to be functionally, histologically, and clinically distinct. Each type of oral mucosa is believed to develop through discrete molecular mechanisms, which remain unclear. MicroRNAs (miRNAs) are 19 to 25nt non-coding small single-stranded RNAs that negatively regulate gene expression by binding target mRNAs. miRNAs are crucial for fine-tuning of molecular mechanisms. To investigate the role of miRNAs in oral mucosa development, we examined mice with mesenchymal (Wnt1Cre;Dicer(fl/fl)) conditional deletion of Dicer. Wnt1Cre;Dicer(fl/fl) mice showed trans-differentiation of lining mucosa into an epithelium with masticatory mucosa/ skin-specific characteristics. Up-regulation of Fgf signaling was found in mutant lining mucosal epithelium that was accompanied by an increase in Fgf7 expression in mutant mesenchyme. Mesenchyme miRNAs thus have an indirect effect on lining mucosal epithelial cell growth/differentiation.

Towards a rational antimicrobial testing policy in the laboratory.

Antimicrobial policy for prophylactic and therapeutic use of antimicrobials in a tertiary care setting has gained importance. A hospital's antimicrobial policy as laid down by its hospital infection control team needs to include inputs from the microbiology laboratory, besides the pharmacy and therapeutic committee. Therefore, it is of utmost importance that clinical microbiologists across India follow international guidelines and also take into account local settings, especially detection and presence of resistance enzymes. This article draws a framework for rational antimicrobial testing in our laboratories in tertiary care centers, from the Clinical and Laboratory Standards Institute guidelines. It does not address testing methodologies but suggests ways and means by which antimicrobial susceptibility reporting can be rendered meaningful not only to the treating physician but also to the resistance monitoring epidemiologist. It hopes to initiate some standardization in rational choice of antimicrobial testing in laboratories in the country pertaining to nonfastidious bacteria.

Mupirocin resistance in clinical isolates of staphylococci in a tertiary care centre in south India.

The present study was carried out to determine the rates of high-level and low-level mupirocin resistance in Staphylococcus spp. (MuH and MuL) in southern India. A prospective study was carried out on Staphylococcus spp. isolated for a period of three months in the microbiology laboratory of an 800-bedded tertiary care hospital. One hundred sixty-seven non-duplicate Staphylococcus spp. isolated from different specimens were tested for mupirocin susceptibility using 5 and 200 µg discs and by agar dilution. Rates of MuH were found to be two percent in methicillin-resistant Staphylococcus aureus (MRSA) and 28% in methicillin-resistant coagulase-negative Staphylococcus spp. (MRCoNS). MuL strains may be still treated with mupirocin, while MuH strains require other treatment options for eradication, making prior screening and differentiation important.

Tocopherol transfer protein deficiency modifies nuclear receptor transcriptional networks in lungs: modulation by cigarette smoke in vivo.

Dietary factors and environmental pollutants initiate signaling cascades that converge on AhR:Nrf2:NF-kappaB transcription factor (TF) networks and, in turn, affect the health of the organism through its effects on the expression of numerous genes. Reactive oxygen metabolites (ROMs) have been hypothesized to be common mediators in these pathways. alpha-Tocopherol (AT) is a potent, lipophilic, scavenger of ROMs in vitro and has been hypothesized to be a major chain-breaking anti-oxidant in lipoproteins and biological membranes in vivo. The lung offers a vital organ to test the various postulated actions of AT in vivo. Lung AT concentrations can be manipulated by several methods that include dietary and genetic techniques. In this study we have used mice with severe AT deficiency inflicted at birth by the deletion of AT transfer protein (ATTP) which is abundantly expressed in the liver and regulates systemic concentrations of AT. Mice and humans deficient in ATTP are AT deficient. Female ATTP-deficient (ATTP-KO) mice and their congenic ATTP normal (WT) mice fed a diet containing 35 IU AT/kg diet were used to test our hypothesis. The mice (n=5/group) were exposed to either air or cigarette smoke (CS, total suspended particles 60 mg/m(3), 6h/day), a source of ROM, for 3 or 10 days. Post-exposure lung tissue was dissected, RNA extracted from each lung and it was pooled group-wise and processed for GeneChip analysis (Affymetrix 430A 2.0). Differential analysis of the transcriptomes ( approximately 16,000 mRNAs) identified CS sensitive genes that were modulated by lung AT-concentration. CS activated AhR driven genes such as cyp1b1 whose induction was augmented in CS-exposed, AT-deficient lungs. However, CS-induced expression of some of the Nrf2 driven genes was not potentiated in the AT-deficient lungs. Largest clusters of CS-AT sensitive genes were lymphocyte and leukocyte specific genes. These gene-clusters included those encoding cytokines and immunoglobulins, which were repressed by CS and were modulated by lung AT concentrations. Our genome-wide analysis suggests reciprocal regulation of xenobiotic and immune response genes by CS and a modulatory role of lung AT concentration on the expression of these clusters of genes. These data suggest that in vivo network of AT, AT-metabolites and ATTP affects the transcription of genes driven by AhR, Nrf2 and NF-kappaB, transcription factor networks that transduce cellular metabolic signals and orchestrate adaptive responses of lungs to inhaled environmental pollutants.

Studies on Bacillus stearothermophilus. Part IV. Influence of enhancers on biotransformation of testosterone.

The impact of chemical enhancers on the biotransformation of testosterone has been exploited. Application of crude cell concentrates to produce Bacillus stearothermophilus-mediated bioconversion of testosterone at 65 degrees C for 72 h has been examined. After incubation, the xenobiotic substrate was added to the concentrated whole cell suspensions. The enhancer molecules were included in the whole cell suspension. The resultant products, after extraction into an organic solvent, were purified by thin layer chromatography and identification was carried out through spectroscopic data. Five steroid metabolites 9,10-seco-4-androstene-3,9,17-trione, 5alpha-androstan-3,6,17-trione, 17beta-hydroxy-5alpha-androstan-3,6-dione, 3beta,17beta-dihydroxyandrost-4-ene-6-one and 17beta-hydroxyandrost-4,6-diene-3-one were identified as biotransformation products of testosterone. A possible biosynthetic route for these bioconversion products is postulated.

Studies on Bacillus stearothermophilus. Part III. Transformation of testosterone.

Bacillus stearothermophilus, a thermophilic bacterium isolated from the Kuwaiti desert, produced a variety of monohydroxy androstene derivatives and an oxidized product when incubated with exogenous testosterone for 24 h at 65 degrees C. The major metabolite was identified as androst-4-en-3,17-dione while minor metabolites included 6 alpha-hydroxyandrost-4-en-3,17-dione, 6 beta-hydroxyandrost-4-en-3,17-dione, 6 alpha-hydroxytestosterone, and 6 beta-hydroxytestosterone. These metabolites were purified by TLC and HPLC followed by their identification using (1)H- and (13)C-NMR and other spectroscopic data.

Study on dosimetric parameters for stereotactic radiosurgery and intensity-modulated radiotherapy.

This study is an attempt to compare the dosimetric parameters of intensity-modulated radiation therapy (IMRT) and stereotactic radiosurgery (SRS) using patient data. Radiosurgery was delivered through circular tertiary collimators attached to a linear accelerator. Six patients who were treated with SRS were replanned and evaluated with the IMRT planning system. Contouring of all structures, including target volume, was done on the IMRT system to closely match the SRS system. Treatment plans were generated after specifying the goals in the prescription module. The NOMOS BEAK collimator attached to the NOMOS MIMiC delivery device was chosen for treatment delivery. Various parameters such as conformity index, homogeneity index, target volume coverage, nontarget tissue, and brainstem doses were calculated and compared between the IMRT and SRS systems. Patient data were divided into 2 groups based on the complexity of the lesion and the number of isocenters used for radiosurgery. Analysis was done for each group and for the cumulative data. Superior conformality and homogeneous dose distribution in IMRT for multiple isocenter cases were observed. In addition, critical structure volumes for 50%, 70%, and 90% of the prescribed dose were lower in IMRT compared to SRS treatment. However, nontarget tissue received significantly higher doses with IMRT plans. Results show that IMRT treatment modality produces similar results as radiosurgery for small, spherical lesions, whereas it is found to be superior to SRS for irregular lesions in terms of critical structure sparing and better dose homogeneity.

Studies on Bacillus stearothermophilus. Part II. Transformation of progesterone.

Bacillus stearothermophilus, a thermophilic bacterium isolated from Kuwaiti desert, when incubated with exogenous progesterone for 10 days at 65 degrees C produced two new dihydroxy isomers of progesterone, and two known compounds, 5 alpha-pregnane-3,6,20-trione and 6-dehydroprogesterone, along with the earlier reported monohydroxylated metabolites and a B-Seco compound. The two new dihydroxy compounds were identified as 6 alpha,20 alpha-dihydroxyprogesterone and 6 beta,20 alpha-dihydroxyprogesterone. These metabolites were purified by TLC and HPLC followed by their identification through 1H, 13C NMR and other spectroscopic data.

Studies on Bacillus stearothermophilus. Part 1. Transformation of progesterone to a new metabolite 9,10-seco-4-pregnene-3,9,20-trione.

When Bacillus stearothermophilus, a thermophilic bacterium isolated from the Kuwaiti desert, was incubated with exogenous progesterone for 24 h, three monohydroxylated metabolites were produced. 20alpha-Hydroxyprogesterone was the major metabolite produced in 60.8 relative percentage yield. The other two monohydroxylated metabolites were identified as 6beta-hydroxyprogesterone and the rare 6alpha-hydroxyprogesterone in 21.0 and 13.6 relative percentage yields, respectively. A new metabolite 9,10-seco-4-pregnene-3,9,20-trione was isolated in 3.7 relative percentage yield. All metabolites were purified by preparative TLC and HPLC followed by their identification using 1H, 13C NMR and other spectroscopic data.

Acute pancreatitis in a child with idiopathic ulcerative colitis on long-term 5-aminosalicylic acid therapy.

Acute pancreatitis is a rare but known complication of inflammatory bowel disease in adults. In children, only a few cases with this complication have been reported. We describe a 10-year-old boy with ulcerative colitis who developed acute pancreatitis while on long-term treatment with 5-aminosalicylic acid.

Effect of oil of hydnocarpus on wound healing.

Oil of hydnocarpus has been replaced by other chemotherapeutic agents which have a better mycobactericidal effect. However, none of the currently used antileprosy drugs has been reported to have a positive effect in wound healing. Anecdotal reports claim that leprosy patients who have taken capsules containing oil of hydnocarpus orally have shown more rapid wound healing than those not receiving it. In view of these reports, a pilot experimental study was undertaken to determine the effect of the oil of hydnocarpus in wounds experimentally inflicted on male Wistar rats. The wound-healing effect of oil of hydnocarpus was studied with reference to collagenation and the strength of the scar tissue. The drug-treated group showed a significant increase in body weight and strength of scar tissue in the incision model and, also, increased strength of the collagen tissue and hydroxyproline content in the dead space model. The results of this pilot study indicate that the oil of hydnocarpus, which also has antileprotic activity, could be a useful adjunct in the healing of wounds and ulcers in leprosy patients.

Immunomodulation of excretory secretory materials from the filarial parasiteSetaria digitata.

ES materials released along with the release of mf showed immunosuppression as evidenced by a decrease in T lymphocyte levels in the immunised animals. Lipid fractions of the mf associated ES materials and protein fractions of the detergent soluble materials were found to cause suppression of immune response in the host. Further study revealed that the suppression associated with the lipid fractions is actually the end result and that mf associated ES materials is actually a mixture of immunosuppressive and immunopotentiating components and the release of the components is most likely regulated.

Lymphangiographic evaluation of patients with clinical lepromatous leprosy on clofazimine.

Pedal edema as a possible adverse effect of clofazimine therapy in leprosy was first reported in 1990. Raasch, et al. reported their lymphangiographic findings on ten patients who had clinical lepromatous leprosy in 1969. None of these patients had been on clofazimine therapy. Our study, therefore, was designed to assess the changes that might be seen in the lymphatic system of patients treated with clofazimine for the management of leprosy. Our findings are compared with those of Raasch and his colleagues.