Impact of host genetics on susceptibility and resistance to Mycobacterium avium subspecies Paratuberculosis infection in domestic ruminants

Johne's disease or Paratuberculosis has emerged as major infectious disease of animals in general and domestic livestock in particular on global basis. There have been major initiatives in developed countries for the control of this incurable malady of animals and human beings alike (inflammatory bowel disease or Crohn's disease). Disease has not received similar attention due to inherent complexities of disease, diagnosis and control, in resource poor counties around the world. However, the rich genetic diverstiy of the otherwise low productive animal population offers opportunity for the control of Johne's disease and improve per animal productivity. Present review aims to gather and compile information available on genetics or resistance to Johne's disease and its future exploitation by resource poor countries rich in animal diversity. This review will also help to create awareness and share knowledge and experience on prevalence and opportunities for control of Johne's disease in the livestock population to boost per animal productivity among developing and poor countries of the world. Breeding of animals for disease resistance provides good, safe, effective and cheaper way of controlling Johne's disease in animals, with especial reference to domestic livestock of developing and poor countries. Study will help to establish better understanding of the correlation between host cell factors and resistance to MAP infection which may have ultimately help in the control of Johne's disease in future.

ROS-PIASγ cross talk channelizes ATM signaling from resistance to apoptosis during chemosensitization of resistant tumors

With the existing knowledge of ATM's role in therapeutic resistance, the present study aimed at identifying the molecular mechanisms that influence ATM to oscillate between chemoresistance and chemosensitivity. We observed that the redox status of tumors functions as a major determinant of ATM-dependent ‘resistance-to-apoptosis' molecular switch. At a low reactive oxygen species (ROS) condition during genotoxic insult, the ATM/sumoylated-IKKγ interaction induced NFκB activation that resisted JNK-mediated apoptosis, whereas increasing cellular ROS restored ATM/JNK apoptotic signaling. A search for the upstream missing link revealed that high ROS induces oxidation and ubiquitin-mediated degradation of PIASγ, thereby disrupting PIASγ-IKKγ cross talk, a pre-requisite for IKKγ sumoylation and subsequent NFκB activation. Interruption in the PIASγ-mediated resistance pathway channels ATM signaling toward ATM/JNK pro-death circuitry. These in vitro results also translated to sensitive and resistant tumor allograft mouse models in which low ROS-induced resistance was over-ruled in PIASγ knockout tumors, while its overexpression inhibited high ROS-dependent apoptotic cues. Cumulatively, our findings identified an unappreciated yet critical combinatorial function of cellular ROS and PIASγ in regulating ATM-mediated chemosensitization of resistant tumors. Thus, therapeutic strategies employing ROS upregulation to inhibit PIASγ during genotoxic therapy may, in future, help to eliminate the problems of NFκB-mediated tumor drug resistance.

Molecular characterization of Chilli leaf curl virus and satellite molecules associated with leaf curl disease of Amaranthus spp

Amaranthus, collectively known as amaranth, is an annual or short-lived perennial plant used as leafy vegetables, cereals and for ornamental purposes in many countries including India. During 2011, leaf samples of Amaranthus plants displaying leaf curling, leaf distortion, leaf crinkling and yellow leaf margins were collected from Banswara district, Rajasthan in India. Full-length clones of a monopartite begomovirus, a betasatellite and an alphasatellite were characterized. The complete nucleotide sequence of the isolated begomovirus features as a typical 'Old World' begomovirus with the highest nucleotide per cent identity with Chilli leaf curl virus and hence, considered as an isolate of Chilli leaf curl virus. The complete nucleotide sequences of betasatellite and alphasatellite possess maximum nucleotide identity with Tomato yellow leaf curl Thailand betasatellite and Chilli leaf curl alphasatellite, respectively. This is the first report of the association of chilli-infecting begomovirus and satellite molecules infecting a new host, Amaranthus, causing leaf curl disease.

EGFR wild type antagonizes EGFRvIII-mediated activation of Met in glioblastoma

Epidermal growth factor receptor (EGFR)vIII is the most common EGFR mutant found in glioblastoma (GBM). EGFRvIII does not bind ligand, is highly oncogenic and is usually coexpressed with EGFR wild type (EGFRwt). EGFRvIII activates Met, and Met contributes to EGFRvIII-mediated oncogenicity and resistance to treatment. Here, we report that addition of EGF results in a rapid loss of EGFRvIII-driven Met phosphorylation in glioma cells. Met is associated with EGFRvIII in a physical complex. Addition of EGF results in a dissociation of the EGFRvIII-Met complex with a concomitant loss of Met phosphorylation. Consistent with the abrogation of Met activation, addition of EGF results in the inhibition of EGFRvIII-mediated resistance to chemotherapy. Thus, our study suggests that ligand in the milieu of EGFRvIII-expressing GBM cells is likely to influence the EGFRvIII-Met interaction and resistance to treatment, and highlights a novel antagonistic interaction between EGFRwt and EGFRvIII in glioma cells.

Infant and Young Child Feeding Perceptions and Practices among Mothers in a Rural Area of West Bengal, India

Background:

There are many wrong practices and perceptions of Infant and Young Child Feeding (IYCF) prevalent among different socio-demographic groups.

Aim:

To observe IYCF perceptions and practices among mothers in a rural area of West Bengal.

Subjects and Methods:

Clinic-based cross-sectional descriptive study by interviewing mothers of 0-23 month old children. Appropriate response to each selected key question was assigned a score of + 1 for objective assessment. Data analysis was done by standard statistical methods using the statistical software SPSS 13.0 (Kolkata, India) for windows version. Percentages were calculated for descriptive statistics. Chi-square test of significance was employed whenever required.

Results:

65.8% (225/342) mothers did not initiate breast feeding within 1 h of birth, 41.7% (90/216) mothers of children aged 6 months or more did not exclusively breastfeed their babies up to 6 months and 28.1% (96/342) used bottles for baby-feeding. Perception scores among younger than 20-year-old mothers were found to be highest; however, practice score increased significantly with age. Though perception and practice of mothers with some education were significantly better they wane with higher education. Lowest practice score was found in the richest per capita income group.

Conclusion:

Emphasis should be given to IYCF education sessions.

An EGFR wild type-EGFRvIII-HB-EGF feed-forward loop regulates the activation of EGFRvIII

EGFRvIII is a key oncogene in glioblastoma (GBM). EGFRvIII results from an in-frame deletion in the extracellular domain of EGFR, does not bind ligand and is thought to be constitutively active. Although EGFRvIII dimerization is known to activate EGFRvIII, the factors that drive EGFRvIII dimerization and activation are not well understood. Here we present a new model of EGFRvIII activation and propose that oncogenic activation of EGFRvIII in glioma cells is driven by co-expressed activated EGFR wild type (EGFRwt). Increasing EGFRwt leads to a striking increase in EGFRvIII tyrosine phosphorylation and activation while silencing EGFRwt inhibits EGFRvIII activation. Both the dimerization arm and the kinase activity of EGFRwt are required for EGFRvIII activation. EGFRwt activates EGFRvIII by facilitating EGFRvIII dimerization. We have previously identified HB-EGF, a ligand for EGFRwt, as a gene induced specifically by EGFRvIII. In this study, we show that HB-EGF is induced by EGFRvIII only when EGFRwt is present. Remarkably, altering HB-EGF recapitulates the effect of EGFRwt on EGFRvIII activation. Thus, increasing HB-EGF leads to a striking increase in EGFRvIII tyrosine phosphorylation while silencing HB-EGF attenuates EGFRvIII phosphorylation, suggesting that an EGFRvIII-HB-EGF-EGFRwt feed-forward loop regulates EGFRvIII activation. Silencing EGFRwt or HB-EGF leads to a striking inhibition of EGFRvIII-induced tumorigenicity, while increasing EGFRwt or HB-EGF levels resulted in accelerated EGFRvIII-mediated oncogenicity in an orthotopic mouse model. Furthermore, we demonstrate the existence of this loop in human GBM. Thus, our data demonstrate that oncogenic activation of EGFRvIII in GBM is likely maintained by a continuous EGFRwt-EGFRvIII-HB-EGF loop, potentially an attractive target for therapeutic intervention.

Differential pathogenicity among Tomato leaf curl Gujarat virus isolates from India

Tomato leaf curl Gujarat virus (ToLCGV) has been identified as one of the most destructive pathogens causing tomato leaf curl disease (ToLCD) in India. In the tomato growing regions of Dhanbad and Ramgarh, plants bearing severe symptoms of ToLCD such as leaf curling, leaf crinkling, yellowing and leaf rolling was observed in the farmer fields. The association of begomovirus in these samples was confirmed by PCR and the causal viruses were identified as the isolates of ToLCGV. However, association of cognate DNA B component could not be ascertained from these samples. Indeed, like other Old World begomoviruses, the present ToLCGV isolates were found to be associated with a particular betasatellite, Tomato yellow leaf curl Thailand betasatellite (TYLCTHB). Although DNA A of both ToLCGV isolates could alone infect tomato inducing systemic symptoms, the difference in virulence was observed. Co-inoculation of TYLCTHB reduced the incubation period without influencing the accumulation of helper virus DNA and hence, differential pathogenesis among ToLCGV isolates was governed by the helper component rather than betasatellite. ToLCGV infection with DNA B increases the accumulation of DNA A component of Dhanbad isolate but not of Ramgarh isolate. Results indicated that the begomovirus identified from Ramgarh sample was a mild strain of ToLCGV.

Identification of 11 polymorphic simple sequence repeat loci in the phytopathogenic fungus Fusarium pseudograminearum as a tool for genetic studies

Simple sequence repeat (SSR) markers for Fusarium pseudograminearum with 2 to 3 bp repeat motifs were identified by screening the genome database of the related species Fusarium graminearum. Twelve SSRs amplified single loci in both F. graminearum and F. pseudograminearum. Forty F. pseudograminearum and six F. graminearum individual isolates were screened to determine levels of polymorphism, with all SSRs displaying three to 14 alleles across all isolates. Eleven SSRs were polymorphic across F. pseudograminearum isolates tested proving the usefulness of genome databases of closely related species in identifying genetic markers.

Hepatocellular carcinoma metastasis to the tip of the coracoid process

Hepatocellular carcinoma (HCC) is the commonest and the most frequent primary malignant tumour of the liver. Chronic hepatitis B is the most common cause of HCC. Metastatic HCC has an aggressive course and a poor outcome. Common sites of hematogenous metastasis are lungs, bones & adrenal glands. Involvement of vertebra, pelvis, rib & skull is reported but coracoid process of scapula is an extremely rare site of metastasis. Thus we are going to present an unusual site of metastasis of HCC to the tip of the coracoid process of left scapula which was presented as a nodular swelling over the lateral aspect of left shoulder. On examination viral marker revealed HBsAg positive & negative negative hepatitis C virus (HCV). Ultrasonography of abdomen revealed large, well defined, heterogenous mass measuring 12×7.5 cm in the left lobe of liver. Chest radiograph showed a small radio opaque shadow on the tip of the coracoid process of left scapula. Fine needle aspiration cytology (FNAC) was done from the nodule & cytological examination showed malignant hepatocytes & traversing endothelial cells resembling hepatocellular carcinoma.

A case of Gaucher's disease progressing to liver cirrhosis

We are going to present a 17 year old female with Gaucher's disease. The patient presented with fever, cough, respiratory distress & abdominal heaviness. There was mild pallor, redness of palm of hands & raised temperature. Liver was hugely enlarged along with splenomegaly. X-ray chest showed non specific bronchiectatic change in both lungs. Ultrasonography of abdomen revealed marked hepatosplenomegaly with no ascites. Bone marrow examination showed cellular marrow with plenty of megakaryocytes. Most of the cells were smear cells & there was histiocytes proliferation & infiltration of bone marrow by small atypical cells. Histologically, lipid was found in hepatocytes in moderate amount. The portal areas showed high lipid contents in macrophages. Different clinical findings & incidental diagnosis of lipid storage disease submerged us in diagnostic dilemma. We give conservative treatment with antibiotic cefuroxime, syrup lactulose & vitamins and this patient was improved.

Antibiotic prophylaxis is unnecessary in clean surgery

A significant number of paediatric surgical patients undergone clean surgical procedures. Most of the paediatric surgeon use perioperative prophylactic antibiotic in this clean procedure because of undue fear of infection in their mind. The objective of this study is to evaluate whether the use of perioperative prophylactic antibiotics have an effect to prevent post operative wound infection in clean operation in paediatric surgical patients. This study was conducted in the paediatric surgery department of Bangabandhu Sheikh Mujib Medical University and some private clinics of Dhaka city from January 2009 to December 2009. Two hundred patients who were undergone clean elective surgical procedure on day case basis were included in this study. They were divided into two equal groups (Group A and Group B). The patients of Group A were given intransverse Cephradine 30 minutes before incision and then oral Cephradine was advised postoperatively for 7 days. The patients of Group B were not given any perioperative antibiotic. All the patients of both groups were advised to come on 3rd, 6th and 10th postoperative day for examination of wound. In Group A (With chemo prophylaxis), five patients (5%) developed postoperative wound infection and in Group B (without chemo prophylaxis), three patients (3%) developed postoperative wound infection. Thus the rate of postoperative wound infection is slightly more in patients with chemo prophylaxis but it was not statistically significant by chi-square test. Based on the result of this study, it may be concluded that the antibiotic prophylaxis is not necessary in clean surgery in paediatric age group.

Femoroacetabular impingement and comparison of radiological indexes: a study on 50 cases

To study the asphericity of femoral head in femoroacetabular impingement using radiological indices such as alpha angle and triangular index, and to compare the alpha angle and triangular index measured in the radiograph and MRI. The study was conducted prospectively from January 2008 to June 2009 on 50 consecutive patients of suspected cam-type FAI hip, reporting to orthopedics outpatients department of Postgraduate Institute of Medical Education and Research. Radiograph of the affected hip was taken, and then alpha angle and triangular index are measured and compared. The mean alpha angle in anteroposterior view was measured as 75° ± 10°, and the mean in lateral view was 740 ± 80. In MRI the mean alpha angle was 79° ± 9°. The mean triangular index in radiograph was 2.9 ± 1.2. In MRI the mean triangular index was 2.6 ± 0.8. Frog-leg lateral view is sufficient for the diagnosis of the cam-type femoroacetabular impingement. But MRI is required in cases, where surgical intervention is planned to rule out other pathological condition and for decision making.

A 10 year old boy with rectal carcinoma

A 10 year old boy with mucinous carcinoma of rectum is a rare case at this age. Here the patient presented with constipation, mucus in stool & abdominal pain since one month. He got consultation from several physicians & went through sonology of whole abdomen several times. There he was missed diagnosed as a case of pyloric stenosis. We came to a probable diagnosis by doing simple digital rectal examination which seemed to be a hard rectal swelling. The diagnosis was established by colonoscopy followed by biopsy. Carcinoma rectum must be considered as a differential diagnosis if patient presents with altered bowel habit, per rectal bleeding, abdominal pain in conjunction with weight loss.

Composition and temperature-induced structural changes in lead-tellurite glasses on different length scales

Processes occurring at macroscopic and microscopic length scales across the glass transition (T(g)) in lead-tellurite glass (PbO)(x)(TeO(2))(1-x) (x = 0.1-0.3) are investigated using Brillouin and Raman spectroscopy, respectively. For all the samples, the temperature dependence of the longitudinal acoustic (LA) mode is found to exhibit a universal scaling below T(g) and a rapid softening above T(g). The lower value of elastic modulus at a higher concentration of network modifier PbO, estimated from Brillouin data, arises due to loss of network rigidity. From quantitative analysis of the reduced Raman spectra, several modes are found to exhibit anomalous changes across T(g). Instead of the expected anharmonic behaviour, several modes exhibit hardening, suggesting stiffening of the stretching force constants with temperature, the effect being more pronounced in glasses with higher x. In addition, incorporation of PbO in the glass is also found to narrow down the bond-length distribution, as evident from the sharpening of the Raman bands. The stiffening of the force constants of molecular units at a microscopic length scale and the decrease of elastic constant attributed to loss of network rigidity on a macroscopic length scale appear to be opposite. These different behaviours at two length scales are understood on the basis of a microscopic model involving TeO(n) and PbO units in the structure.

An improved plant regeneration and Agrobacterium - mediated transformation of red pepper (Capsicum annuum L.)

Capsicum annuum (red pepper) is an important spice cum vegetable crop in tropical and subtropical countries. Here, we report an effective and reproducible auxin free regeneration method for six different red pepper cultivars (ACA-10, Kashi Anmol, LCA-235, PBC-535, Pusa Jwala and Supper) using hypocotyl explants and an efficient Agrobacterium-mediated transformation protocol. The explants (hypocotyls, cotyledonary leaves and leaf discs) collected from axenic seedlings of six red pepper cultivars were cultured on either hormone free MS medium or MS medium supplemented with BAP alone or in combination with IAA. Inclusion of IAA in the regeneration medium resulted in callus formation at the cut ends of explants, formation of rosette leaves and ill defined shoot buds. Regeneration of shoot buds could be achieved from hypocotyls grown in MS medium supplemented with different concentrations of BAP unlike other explants which failed to respond. Incorporation of GA3 in shoot elongation medium at 0.5 mg/l concentration enhanced the elongation in two cultivars, LCA-235 and Supper, while other cultivars showed no significant response. Chilli cultivar, Pusa Jwala was transformed with βC1 ORF of satellite DNA β molecule associated with Chilli leaf curl Joydebpur virus through Agrobacterium tumefaciens. Transgene integration in putative transformants was confirmed by PCR and Southern hybridization analysis.

Diagnostic accuracy of dynamic contrast-enhanced MR imaging using a phase-derived vascular input function in the preoperative grading of gliomas

BACKGROUND AND PURPOSE

The accuracy of tumor plasma volume and K(trans) estimates obtained with DCE MR imaging may have inaccuracies introduced by a poor estimation of the VIF. In this study, we evaluated the diagnostic accuracy of a novel technique by using a phase-derived VIF and "bookend" T1 measurements in the preoperative grading of patients with suspected gliomas.

MATERIALS AND METHODS

This prospective study included 46 patients with a new pathologically confirmed diagnosis of glioma. Both magnitude and phase images were acquired during DCE MR imaging for estimates of K(trans)_φ and V(p_)φ (calculated from a phase-derived VIF and bookend T1 measurements) as well as K(trans)_SI and V(p_)SI (calculated from a magnitude-derived VIF without T1 measurements).

RESULTS

Median K(trans)_φ values were 0.0041 minutes(-1) (95 CI, 0.00062-0.033), 0.031 minutes(-1) (0.011-0.150), and 0.088 minutes(-1) (0.069-0.110) for grade II, III, and IV gliomas, respectively (P ≤ .05 for each). Median V(p_)φ values were 0.64 mL/100 g (0.06-1.40), 0.98 mL/100 g (0.34-2.20), and 2.16 mL/100 g (1.8-3.1) with P = .15 between grade II and III gliomas and P = .015 between grade III and IV gliomas. In differentiating low-grade from high-grade gliomas, AUCs for K(trans)_φ, V(p_φ), K(trans)_SI, and V(p_)SI were 0.87 (0.73-1), 0.84 (0.69-0.98), 0.81 (0.59-1), and 0.84 (0.66-0.91). The differences between the AUCs were not statistically significant.

CONCLUSIONS

K(trans)_φ and V(p_)φ are parameters that can help in differentiating low-grade from high-grade gliomas.

Biaxial nematic order induced by smectic fluctuations

We report on a series of measurements on the microscopic structure and the magneto-optical properties of a calamitic liquid crystalline compound in its nematic phase. Structural studies show the existence of short-range, tilted smectic order consistent with pretransitional effects above an underlying smectic phase. Concomitantly, magneto-optical results exhibit the existence of an optic axis not collinear with the uniaxial director. This apparent biaxial nature is discussed within the context of coupling between the tensor nematic and the smectic order parameters.

Biology and interactions of two distinct monopartite begomoviruses and betasatellites associated with radish leaf curl disease in India

BACKGROUND

Emerging whitefly transmitted begomoviruses are major pathogens of vegetable and fibre crops throughout the world, particularly in tropical and sub-tropical regions. Mutation, pseudorecombination and recombination are driving forces for the emergence and evolution of new crop-infecting begomoviruses. Leaf curl disease of field grown radish plants was noticed in Varanasi and Pataudi region of northern India. We have identified and characterized two distinct monopartite begomoviruses and associated beta satellite DNA causing leaf curl disease of radish (Raphanus sativus) in India.

RESULTS

We demonstrate that RaLCD is caused by a complex of two Old World begomoviruses and their associated betasatellites. Radish leaf curl virus-Varanasi is identified as a new recombinant species, Radish leaf curl virus (RaLCV) sharing maximum nucleotide identity of 87.7% with Tomato leaf curl Bangladesh virus-[Bangladesh:2] (Accession number AF188481) while the virus causing radish leaf curl disease-Pataudi is an isolate of Croton yellow vein mosaic virus-[India] (CYVMV-IN) (Accession number AJ507777) sharing 95.8% nucleotide identity. Further, RDP analysis revealed that the RaLCV has a hybrid genome, a putative recombinant between Euphorbia leaf curl virus and Papaya leaf curl virus. Cloned DNA of either RaLCV or CYVMV induced mild leaf curl symptoms in radish plants. However, when these clones (RaLCV or CYVMV) were individually co-inoculated with their associated cloned DNA betasatellite, symptom severity and viral DNA levels were increased in radish plants and induced typical RaLCD symptoms. To further extend these studies, we carried out an investigation of the interaction of these radish-infecting begomoviruses and their associated satellite, with two tomato infecting begomoviruses (Tomato leaf curl Gujarat virus and Tomato leaf curl New Delhi virus). Both of the tomato-infecting begomoviruses showed a contrasting and differential interaction with DNA satellites, not only in the capacity to interact with these molecules but also in the modulation of symptom phenotypes by the satellites.

CONCLUSION

This is the first report and experimental demonstration of Koch's postulate for begomoviruses associated with radish leaf curl disease. Further observations also provide direct evidence of lateral movement of weed infecting begomovirus in the cultivated crops and the present study also suggests that the exchange of betasatellites with other begomoviruses would create a new disease complex posing a serious threat to crop production.

Accuracy of brain imaging in the diagnosis of idiopathic intracranial hypertension

AIM

To investigate the accuracy of individual and combinations of signs on brain magnetic resonance imaging (MRI) and magnetic resonance venography (MRV) in the diagnosis of idiopathic intracranial hypertension (IIH).

MATERIALS AND METHODS

This study was approved by the institutional research ethics board without informed consent. Forty-three patients and 43 control subjects were retrospectively identified. Each patient and control had undergone brain MRI and MRV. Images were anonymized and reviewed by three neuroradiologists, blinded to clinical data, for the presence or absence of findings associated with IIH. The severity of stenosis in each transverse sinus was graded and summed to generate a combined stenosis score (CSS). The sensitivity, specificity, and likelihood ratios (LR) were calculated for individual and combinations of signs.

RESULTS

Partially empty sella (specificity 95.3%, p < 0.0001), flattening of the posterior globes (specificity 100%, p < 0.0001), and CSS <4 (specificity 100%, p < 0.0001) were highly specific for IIH. The presence of one sign, or any combination, significantly increased the odds of a diagnosis of IIH (LR+ 18.5 to 46, p < 0.0001). Their absence, however, did not rule out IIH.

CONCLUSIONS

Brain MRI with venography significantly increased the diagnostic certainty for IIH if there was no evidence of a mass, hydrocephalus, or sinus thrombosis and one of the following signs was present: flattening of the posterior globes, partially empty sella, CSS <4. However, absence of these signs did not exclude a diagnosis of IIH.

Mathematical modeling of drug release profiles for modified hydrophobic HPMC based gels

Hydroxypropyl methylcellulose (HPMC) is now available in modified hydrophobic forms (Sangelose). In this paper, the effect of viscosity grade and HPMC concentration on in vitro release kinetics of a topically applied drug were studied using gel formulations of a nonsteroidal anti-inflammatory drug (NSAID), diclofenac potassium (DP), with different viscosity grades of the polymer (60L, 60 M, 90 M for hydrophobic HPMC and 50 cPs for conventional hydrophilic HPMC) in different proportions. It was found that hydrophobic HPMC-based gels having a higher viscosity and lower polymer concentration release a notably higher amount of drug compared with hydrophilic HPMC-based gels containing a higher concentration of polymer but with lower viscosity. For gels, the suitability of different common empirical (zero-order, first-order, and Higuchi), and semi-empirical (Ritger-Peppas and Peppas-Sahlin) models, and some new statistical (logistic, log-logistic, Weibull, Gumbel, and generalized extreme value distribution) models to describe the drug release profile were tested through non-linear least-square curve fitting. A general purpose mathematical analysis tool MATLAB was used. Further, instead of the widely used transformed linear fit method, direct fitting was used in the paper to avoid any form of truncation and transformation errors. The results revealed that the log-logistic distribution, amongst all the models investigated, was the best fit for hydrophobic formulations. For hydrophilic ones, the semi-empirical models and Weibull distribution worked best, although log-logistic also showed a close fit. The shape parameter for the log-logistic and Weibull distribution conveys vital information about the rate of release and helps improve understanding of drug release profiles.

Angiogenin functionally interacts with p53 and regulates p53-mediated apoptosis and cell survival

Angiogenin, a 14-kDa multi-functional pro-angiogenic growth factor, is up-regulated in several types of cancers. Anti-angiogenin monoclonal antibodies used as antagonists inhibited the establishment, progression, and metastasis of human cancer cells in athymic mice (Olson et al. 1994). Silencing angiogenin and inhibition of angiogenin’s nuclear translocation blocked cell survival and induced cell death in B-lymphoma and endothelial cells latently infected with Kaposi sarcoma associated herpesvirus (KSHV) (Sadagopan et al. 2009) suggesting that actively proliferating cancer cells could be inducing angiogenin for inhibiting apoptotic pathways. However, the mechanism of cell survival and apoptosis regulation by angiogenin and their functional significance in cancer is not known. We demonstrate that angiogenin interacts with p53 and colocalizes in the nucleus. Silencing endogenous angiogenin induced p53 promoter activation and p53 target gene (p53, p21 and Bax) expression, down-regulated anti-apoptotic Bcl-2 gene expression and increased p53 mediated cell death. In contrast, angiogenin expression blocked pro-apoptotic Bax and p21 expression, induced Bcl-2 and blocked cell death. Angiogenin also co-immunoprecipitated with p53 regulator protein Mdm2. Angiogenin expression resulted in the inhibition of p53 phosphorylation, increased p53-Mdm2 interaction, and consequently increased ubiquitination of p53. Taken together these studies demonstrate that angiogenin promotes the inhibition of p53 function to mediate anti-apoptosis and cell survival. Our results reveal for the first time a novel p53 interacting function of angiogenin in anti-apoptosis and survival of cancer cells and suggest that targeting angiogenin could be an effective therapy for several cancers.

Self-referenced rectangular path cyclic interferometer with polarization phase shifting

A polarization phase shifting interferometer using a cyclic path configuration for measurement of phase nonuniformities in transparent samples is presented. A cube beam splitter masked by two linear polarizers is used to split the source wavefront into two counter propagating linearly polarized beams that pass through the sample. At the output of the interferometer, the two orthogonally polarized beams are rendered circularly polarized in the opposite sense through the use of a quarter wave plate. Finally, phase shifting is achieved by rotating a linear polarizer before the recording plane. In a rectangular path interferometer, although the two counter propagating wavefronts are laterally folded with respect to each other in the interferometer arms, the beams finally emerge mutually unfolded at the output of the interferometer. This phenomenon is utilized to create a reference if the sample is introduced in one lateral half of the beam in any one of the interferometer arms. The polarization phase shifting technique is used to generate four phase-shifted interferograms, which are utilized to evaluate the phase profile of the phase sample. Experimental results presented validate the proposed technique.

Prevalence and causes of low birth weight in India

INTRODUCTION

The aims of the study are (i) to understand inter-zone and interstate variation of low birth weight (LBW) and (ii) to determine the key variables to reduce LBW in India.

METHODS

Using the latest National Family Health Survey (NFHS) data of 2005-06 which showed the percentage distribution of LBW infants, ANOVA and post-hoc test were performed to determine the spatial variation of birth weight. The covariates which influence LBW fell into three categories: (i) social variables which included location, mother's education, religion, access of mothers to newspapers, television and family structure; (ii) economic variable namely, the wealth index, and (iii) biological variables which consisted of sex of the children, birth order, and mother's body mass index (BMI). Three models of Logistic regression were carried out to examine the influence of the combinations of these direct and indirect factors.

RESULTS

In India, nearly 20% of new borns have LBW. Males have less frequency of LBW than females. The North-east zone has the lowest prevalence of LBW while the north zone has the highest. Mother's education, access to TV and nuclear family, and intake of iron tablets are the most important socio-economic influences on the determination of birth weight in India.

CONCLUSION

It is essential to provide proper diet and nutritional care of mothers during pregnancy. Increased education of mothers through programmes in TV and newspapers articles have significant roles to play in reducing LBW in India.

Adsorption kinetics of a fluorescent dye in a long chain fatty acid matrix

This work reports the adsorption kinetics of a highly fluorescent laser dye rhodamine B (RhB) in a preformed stearic acid (SA) Langmuir monolayer. The reaction kinetics was studied by surface pressure-time (π-t) curve at constant area and in situ fluorescence imaging microscopy (FIM). Increase in surface pressure (at constant area) with time as well as increase in surface coverage of monolayer film at air-water interface provide direct evidence for the interaction. ATR-FTIR spectra also supported the interaction and consequent complexation in the complex films. UV-vis absorption and Fluorescence spectra of the complex Langmuir-Blodgett (LB) films confirm the presence of RhB molecules in the complex films transferred onto solid substrates. The outcome of this work clearly shows successful incorporation of RhB molecules into SA matrix without changing the photophysical characteristics of the dye, thus making the dye material as LB compatible.

QRDR mutations, efflux system & antimicrobial resistance genes in enterotoxigenic Escherichia coli isolated from an outbreak of diarrhoea in Ahmedabad, India

BACKGROUND & OBJECTIVES

Diverse mechanisms have been identified in enteric bacteria for their adaptation and survival against multiple classes of antimicrobial agents. Resistance of bacteria to the most effective fluoroquinolones have increasingly been reported in many countries. We have identified that most of the enterotoxigenic Escherichia coli (ETEC) were resistant to several antimicrobials in a diarrhoea outbreak at Ahmedabad during 2000. The present study was done to identify several genes responsible for antimicrobial resistance and mobile genetic elements in the ETEC strains.

METHODS

Seventeen ETEC strains isolated from diarrhoeal patients were included in this study. The antimicrobial resistance was confirmed by conventional disc diffusion method. PCR and DNA sequencing were performed for the identification of mutation in the quinolone resistance-determining regions (QRDRs). Efflux pump was tested by inhibiting the proton-motive force. DNA hybridization assay was made for the detection of integrase genes and the resistance gene cassettes were identified by direct sequencing of the PCR amplicons.

RESULTS

Majority of the ETEC had GyrA mutations at codons 83 and 87 and in ParC at codon 80. Six strains had an additional mutation in ParC at codon 108 and two had at position 84. Plasmid-borne qnr gene alleles that encode quinolone resistance were not detected but the newly described aac(6')-Ib-cr gene encoding a fluoroquinolne-modifying enzyme was detected in 64.7 per cent of the ETEC. Class 1 (intI1) and class 2 (intI2) integrons were detected in six (35.3%) and three (17.6%) strains, respectively. Four strains (23.5%) had both the classes of integrons. Sequence analysis revealed presence of dfrA17, aadA1, aadA5 in class 1, and dfrA1, sat1, aadA1 in class 2 integrons. In addition, the other resistance genes such as tet gene alleles (94.1%), catAI (70.6%), strA (58.8%), bla TEM-1 (35.2%), and aphA1-Ia (29.4%) were detected in most of the strains.

INTERPRETATION & CONCLUSIONS

Innate gene mutations and acquisition of multidrug resistance genes through mobile genetic elements might have contributed to the emergence of multidrug resistance (MDR) in ETEC. This study reinforces the necessity of utilizing molecular techniques in the epidemiological studies to understand the nature of resistance responsible for antimicrobial resistance in different species of pathogenic bacteria.