Surfactin-Conjugated Silver Nanoparticles as an Antibacterial and Antibiofilm Agent against Pseudomonas aeruginosa

The emergence of antimicrobial resistance is an alarming global health concern and has stimulated the development of novel functional nanomaterials to combat multi-drug-resistant (MDR) bacteria. In this work, we demonstrate for the first time the synthesis and application of surfactin-coated silver nanoparticles as an efficient antibacterial and antibiofilm agent against the drug-resistant bacteria Pseudomonas aeruginosa for safe dermal applications. Our in vivo studies showed no significant superficial dermal irritation, edema, and erythema, while microscopic analysis revealed that surfactin-coated silver nanoparticles caused no pathological alterations at the applied concentrations. These results support the potential use of surfactin-coated silver nanoparticles against drug-resistant bacterial biofilm infections and in skin wound dressing applications.

An extendable optical fibre probe survey meter for naturally occurring radioactive material (NORM) and other weak emitters

We have developed a radioluminescence-based survey meter for use in industries in which there is involvement in naturally occurring radioactive material (NORM), also in support of those needing to detect other weak emitters of radiation. The functionality of the system confronts particular shortcomings of the handheld survey meters that are currently being made use of. The device couples a LYSO:Ce scintillator with a photodetector via a polymer optical fibre waveguide, allowing for "intrinsically safe" inspection within pipework, separators, valves and other such component pieces. The small-diameter optical fibre probe is electrically passive, immune to electromagnetic interference, and chemically inert. The readout circuit is entirely incorporated within a handheld casing housing a silicon photomultiplier (SiPM) detection circuit and a microprocessor circuit connected to an LCD display. A 15 m long flexible PMMA optical fibre waveguide is butt coupled to an ABS plastic probe that retains the LYSO:Ce scintillator. Initial tests have included the use of lab-based mixed gamma-ray sources, measurements being made in concert with a reference conventional GM survey-meter. Characterization, via NORM sources at a decontamination facility, has shown useful sensitivity, covering the dose-rate range 0.10- to 28 µSv h^-1 (R-squared 0.966), extending to 80 µSv/h as demonstrated in use of a Cs-137 source. The system is shown to provide an effective tool for detection of radioactivity within hard to access locations, in particular for sources emitting at low radiation levels, down to values that approach background.

Point of care ultrasound: Current and future directions for Acute Medicine

Point of care ultrasound (POCUS) represents an exciting tool for current and future acute care practitioners. POCUS has come a long way in a short space of time and its widespread implementation may well be one of the biggest changes seen in acute medicine across the next decade. This narrative review explores the increasing evidence base for the accuracy of POCUS use in various acute scenarios, whilst also addressing current gaps in the evidence and areas for potential future POCUS development.

Endophytic bacteria of Fagonia indica Burm. f revealed to harbour rich secondary antibacterial metabolites

Endophytic bacteria are the source of novel bioactive compounds, used as therapeutic agent. Molecular docking is a computational technique use frequently, to find novel drugs targets and drugs-receptors interactions. The current study was designed to isolate and identify endophytic bacteria for the extraction of bioactive compounds. Further, to characterized extracts and to explore compounds interactions with bacterial cell wall and outer membrane synthesizing proteins. Endophytes were identified using 16s rRNA amplification technique. For bioactive compounds, solvent extraction method was followed and characterized further through GC-MS analysis. To find targets and drugs-receptors interactions, molecular docking studies and biological assays were performed. The isolated endophytes belong to five different genera namely Enterobacter, Bacillus, Erwinia, Stenotrophomonas and Pantoea. In case of antibacterial assay Stenotrophomonas maltophilia extract showed significant inhibitory zones (15.11±0.11mm and 11.3±0.16) against Staphylococcus caseolyticus and Acinetobacter baumanni, with MIC 33.3 and 50μg/mL respectively. Among the characterized fifty compounds, from endophytic bacteria "antibacterial compound" N-(5-benzyl-10b-hydroxy-2-methyl-3,6-dioxooctahydro-8H-oxazolo[3,2-α] pyrrolo[2,1c] pyrazin-2-yl)-7-methyl2,3,3a,3a1,6,6a,7,8,9,10,10a,10b-dodecahydro-1H-4λ2-indolo[4,3-fg]quinoline-9-carboxamide of bacteria Stenotrophomonas maltophilia were an excellent binder with MurF ligase active site, with binding energy of -10.2 kcal/mol. Extracts of endophytic bacteria composed of various pharmacologically active ingredients such as antibacterial compounds. Molecular docking studies provide important information regarding drug-receptor interaction, thus can be used in novel drug discovery.

Biofunctionalized nano-antimicrobials - progress, prospects and challenges

The rapid emergence of multidrug resistant bacterial strains clearly highlights the need for the development of new antimicrobial compounds/materials to address associated healthcare challenges. Meanwhile, the adverse side effects of conventional antibiotics on human health urge the development of new natural product-based antimicrobials to minimize the side effects. In this respect, we concisely review the recent scientific contributions to develop natural product-based nano-antibiotics. The focus of the review is on the use of flavonoids, peptides, and cationic biopolymer functionalized metal/metal oxide nanoparticles as efficient tools to hit the MDR bacterial strains. It summarizes the most recent aspects of the functionalized nanoparticles against various pathogenic bacterial strains with respect to their minimal inhibitory concentrations and mechanism of action at the cellular and molecular levels. At the end, the future perspectives to materialize the in vivo applications of nano-antimicrobials are suggested on the basis of the available research.

Review of stentless, tubeless, apposed renal (STAR) transplant wound management programme

INTRODUCTION We aimed to review the necessity of conventional interventions in renal transplant for preventing complications arising out of the use of wound drains, ureteral stents and stapled skin closures. METHODS We reviewed a series of 33 patients who received stentless, tubeless/drainless and suture-apposed living donor renal transplants (STAR group) and compared the results to a control non-STAR group of 36 patients in whom all three interventions of drains, stents and skin staples were used. RESULTS No significant differences in demographics and clinical characteristics were observed between the two groups. With regard to the overall surgical complications, no significant differences in terms of wound infection, seroma, perinephric collections, urinoma, bacteriuria or vascular complications were observed between the groups. When analysed according to the interventions specific for preventing complications, although slightly more asymptomatic perinephric collections were observed and two lymphoceles required treatment in the STAR group, these differences were not statistically significant. Similarly, no significant differences in ureteric or skin-related complications were observed between the groups. Both groups had comparable good outcomes for renal function, graft survival and patient survival. CONCLUSION The routine use of ureteric stents, drains or skin staples may not be necessary for uncomplicated renal transplants. Potential complications associated with the placement of these interventions can be avoided without compromising on the safety of patients and/or the outcome of transplants.

Nanoparticles-assisted delivery of antiviral-siRNA as inhalable treatment for human respiratory viruses: A candidate approach against SARS-COV-2

The current pandemic of coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) has challenged healthcare structures across the globe. Although a few therapies are approved by FDA, the search for better treatment options is continuously on rise. Clinical management includes infection prevention and supportive care such as supplemental oxygen and mechanical ventilatory support. Given the urgent nature of the pandemic and the number of companies and researchers developing COVID-19 related therapies, FDA has created an emergency program to move potential treatments with already approved drugs to patients as quickly as possible in parallel to the development of new drugs that must first pass the clinical trials. In this manuscript, we have reviewed the available literature on the use of sequence-specific degradation of viral genome using short-interfering RNA (siRNA) suggesting it as a possible treatment against SARS-CoV-2. Delivery of siRNA can be promoted by the use of FDA approved lipids, polymers or lipid-polymer hybrids. These nanoparticulate systems can be engineered to exhibit increased targetability and formulated as inhalable aerosols.

Chemotherapeutic resistance of head and neck squamous cell carcinoma is mediated by EpCAM induction driven by IL-6/p62 associated Nrf2-antioxidant pathway activation

Overexpression of epithelial cell adhesion molecule (EpCAM) has been associated with chemotherapeutic resistance, leads to aggressive tumor behavior, and results in an adverse clinical outcome. The molecular mechanism by which EpCAM enrichment is linked to therapeutic resistance via Nrf2, a key regulator of antioxidant genes is unknown. We have investigated the link between EpCAM and the Nrf2 pathway in light of therapeutic resistance using head and neck squamous cell carcinoma (HNSCC) patient tumor samples and cell lines. We report that EpCAM was highly expressed in Nrf2-positive and HPV-negative HNSCC cells. In addition, cisplatin-resistant tumor cells consisted of a higher proportion of EpCAM^high cells compared to the cisplatin sensitive counterpart. EpCAM^high populations exhibited resistance to cisplatin, a higher efficiency in colony formation, sphere growth and invasion capacity, and demonstrated reduced reactive oxygen species (ROS) activity. Furthermore, Nrf2 expression was significantly higher in EpCAM^high populations. Mechanistically, expression of Nrf2 and its target genes were most prominently observed in EpCAM^high populations. Silencing of EpCAM expression resulted in the attenuation of expressions of Nrf2 and SOD1 concomitant with a reduction of Sox2 expression. On the other hand, silencing of Nrf2 expression rendered EpCAM^high populations sensitive to cisplatin treatment accompanied by the inhibition of colony formation, sphere formation, and invasion efficiency and increased ROS activity. The molecular mechanistic link between EpCAM expression and activation of Nrf2 was found to be a concerted interaction of interleukin-6 (IL-6) and p62. Silencing of p62 expression in EpCAM^high populations resulted in the attenuation of Nrf2 pathway activation suggesting that Nrf2 pathway activation promoted resistance to cisplatin in EpCAM^high populations. We propose that therapeutic targeting the Nrf2-EpCAM axis might be an excellent approach to modulate stress resistance and thereby survival of HNSCC patients enriched in EpCAM^high populations.

THU0604 UNDIAGNOSED RHEUMATIC DISEASE IN NEWLY PRESENTING MGUS PATIENT

Background:

Monoclonal gammopathy of undetermined significance (MGUS) is considered to be a premalignant condition with on average of 1% annual risk of progression to multiple myeloma or other lymphoproliferative disorders [1]. Numerous studies have highlighted a common feature of autoimmune inflammatory diseases is non-specific hypergammaglobulinaemia which can be associated with monoclonal gammopathy [2, 3]. We looked at a population of 3.6 million where patients with MGUS was referred to haematology network for evaluation.

Objectives:

Our hypothesis was that undiagnosed rheumatic diseases were being referred to haematology rather than rheumatology erroneously.

Methods:

The Haematological Malignancy Research Network (HMRN) ethics approval (REC 04/01/1205/69) from Leeds West Research Ethics Committee. The HMRN that comprises a population-based cohort of patients newly diagnosed by a single integrated haemato-pathology laboratory in two adjacent UK Cancer Networks (population 3.6 million). The database includes prognostic factors, sequential treatment/response history and socio-demographic details which are recorded to clinical trial standards. 255 patients were screened in this study. We looked at a range of autoimmune/innate immune conditions diagnosed after MGUS.

Results:

In the 255 patients cohort group, the average age at the diagnosis of MGUS was 70.23 ± 11.95 years (median 70.2 years), with more subjects being male (n=145, 56.9%). Mean duration of follow up was 2570 days. 10 out of the 255 patients progressed onto multiple myeloma.

Diagnosed rheumatic disease was found in 48 patients (18.8%). None of the patient in this group has disease progression to multiple myeloma. In this group, 37 patients (14.5%) presented the rheumatic disease before their MGUS diagnosis and 11 (4.3%) were diagnosed after their MGUS referral. Interestingly, among the 11, more males(n=8, 72.7%) have their rheumatic disease diagnosed after MGUS.

Those 11 cases included crohn’s disease (1), polymyalgia rheumatica (2), immune thrombocytopenia (2), autoimmune hepatitis (2), Schnitzler’s syndrome (1), giant cell arteritis (1), rheumatoid arthritis (2).

Conclusion:

Approaching 1 in 20 cases of MGUS have an underlying inflammatory disease that may often be non-specifically driving antibody production including monoclonal band formation. When diagnosing MGUS, clinicians should be aware of the potential underlying autoimmune rheumatic conditions.

References:

[1]Kyle, R.A., et al.,A long-term study of prognosis in monoclonal gammopathy of undetermined significance.N Engl J Med, 2002.346(8): p. 564-9.

[2]Renier, G., et al.,Ankylosing spondylitis and monoclonal gammopathies.Ann Rheum Dis, 1992.51(8): p. 951-4.

[3]Sugai, S., et al.,Non-IgM monoclonal gammopathy in patients with Sjogren's syndrome.Am J Med, 1980.68(6): p. 861-6.

Disclosure of Interests:

Qiao Zhou: None declared, Kaiwen Wang: None declared, Laiba Rahman: None declared, Abdulla Watad: None declared, Sinisa Savic: None declared, Eve Roman: None declared, Dennis McGonagle Grant/research support from: Janssen Research & Development, LLC

Widespread expression of Sonic hedgehog (Shh) and Nrf2 in patients treated with cisplatin predicts outcome in resected tumors and are potential therapeutic targets for HPV-negative head and neck cancer

Background:

Sonic hedgehog (Shh) and Nrf2 play a critical role in chemotherapeutic resistance. These two genes have been found to be dysregulated in head and neck squamous cell carcinomas (HNSCC). The purpose of this study was to analyze the expression, function and clinical prognostic relationship of Shh and Nrf2 in HNSCC in the context of therapeutic resistance and cancer stem cells (CSCs).

Methods:

We analyzed a cohort of patients with HNSCC to identify potential therapeutic biomarkers correlating with overall survival (OS) as well as disease-free survival (DFS) from our own data and validated these results using The Cancer Genome Atlas dataset. Expression of Shh and Nrf2 was knocked down by siRNA and cell growth, sphere growth and chemotherapeutic resistance were evaluated.

Results:

Widespread abundant expression of Shh and Nrf2 proteins were associated with shorter OS and DFS. The combination of Shh and Nrf2 expression levels was found to be a significant predictor of patient DFS. The tumor stromal index was correlated with Shh expression and inversely associated with shorter OS and DFS. Inhibition of Shh by siRNA or cyclopamine resulted in the attenuation of resistant CSC self-renewal, invasion, clonogenic growth and re-sensitization to the chemotherapeutic agents. Concomitant upregulation of Shh and Nrf2 proved to be an independent predictor of poor OS and DFS in patients with HNSCC.

Conclusions:

These findings suggest that Shh and Nrf2 could serve as therapeutic targets as well as promising dual prognostic therapeutic biomarkers for HNSCC.

Why has the caesarean rate increased dramatically in Bangladesh?

OBJECTIVE

The objective is to assess the reasoning by families in deciding between a home vs. facility delivery and vaginal vs. caesarean.

STUDY DESIGN

The authors selected a convenience sample of 16 villages in Sathkira district in southwest Bangladesh. Evidence was drawn from detailed in-home post-delivery interviews with all mothers in these villages who delivered in 2015 or 2016.

METHODS

Local family health workers and paramedics used a structured questionnaire that enabled gathering of relevant quantitative and qualitative evidence. Mothers' reasons for selection of delivery location and type were categorized, and regression analysis was conducted to assess significance of variables that proxy supply and demand factors.

RESULTS

Among 492 completed interviews, 48% were home deliveries, 52% facility deliveries; two-thirds of facility deliveries in private clinics. Overall, sample caesarean rate is 39%, public hospital rate 53%, private clinic rate 86%. Over half of reasons for home delivery refer to pregnancy without complication or access to trusted birth attendant. Over half of reasons for facility delivery refer to medical complications allegedly precluding home delivery, or requiring home-to-facility transfer during labour for reasons not clear to the mother. The decision depends on both 'demand' factors originating with the family (proxied by family income, birth order and education levels) and 'supply' factors originating with obstetric care providers (proxied by number of antenatal visits and variation of caesarean rate by village). In a regression controlling for both demand and supply variables, the above proxy variables are all significant.

IMPLICATIONS FOR NURSING AND HEALTH POLICY

Bangladesh has inadequate nursing support for vaginal delivery in either home or facility. Hence, physicians frequently recommend that women deliver in a facility (usually a physician's clinic). Physicians are reluctant to hire adequate nurses to attend vaginal deliveries. Hence, families with some discretionary income are increasingly opting for a caesarean over vaginal delivery. Facility deliveries reduce incidence of obstructed labour fistula, but probably contribute to rising incidence of iatrogenic fistula. Reducing caesarean rates requires a large increase in numbers of nurses and midwives, and acceptance by physicians of a broad scope of practice for nurses/midwives in vaginal deliveries.

Nano-biotechnology: a new approach to treat and prevent malaria

Malaria, the exterminator of ~1.5 to 2.7 million human lives yearly, is a notorious disease known throughout the world. The eradication of this disease is difficult and a challenge to scientists. Vector elimination and effective chemotherapy for the patients are key tactics to be used in the fight against malaria. However, drug resistance and environmental and social concerns are the main hurdles in this fight against malaria. Overcoming these limitations is the major challenge for the 21st-century malarial researchers. Adapting the principles of nano-biotechnology to both vector control and patient therapy is the only solution to the problem. Several compounds such as lipids, proteins, nucleic acid and metallic nanoparticles (NPs) have been successfully used for the control of this lethal malaria disease. Other useful natural reagents such as microbes and their products, carbohydrates, vitamins, plant extracts and biodegradable polymers, are also used to control this disease. Among these particles, the plant-based particles such as leaf, root, stem, latex, and seed give the best antagonistic response against malaria. In the present review, we describe certain efforts related to the control, prevention and treatment of malaria. We hope that this review will open new doors for malarial research.

Eruca sativa seed oil: Characterization for potential beneficial Properties

Eruca sativa (ES) seed oil is used in food preparation and as source of natural medication. Eruca sativa (ES) seed oil was analysed for phenolic composition using high performance liquid chromatography with diode array detection (HPLC-DAD), pigment contents, quality characteristics. The oil was fed to rabbits for two weeks. Serum biochemistry, haematological and liver histological parameters were studied. Results showed that quercetin, caffeic acid and chlorogenic acids were the major phenolic compounds. Lycopene and other pigments were present in considerable amounts. Animal studies showed that the body weight of rabbits decreases with the increase of ES oil. The level of serum glucose, total cholesterols, triglycerides and LDL-cholesterol decrease significantly, while an increase was observed in the HDL-cholesterol. The level of white blood cells including lymphocytes and mean corpuscular haemoglobin concentration increases, while a significant increase occurred in platelets count with the increase of ES seed oil dose. In the present study microscopic observations in control and the treated groups showed similar cytoarchitecture of the liver with no significant histological changes. It is concluded that Eruca sativa seed oil is a rich source of important phytochemicals with anti-obesity properties in selected animals.

An assessment on the role of endophytic microbes in the therapeutic potential of Fagonia indica

Background

Natural products of animals, plants and microbes are potential source of important chemical compounds, with diverse applications including therapeutics. Endophytic bacteria that are especially associated with medicinal plants presents a reservoir of therapeutic compounds. Fagonia indica has been recently investigated by numerous researchers because of its striking therapeutic potential especially in cancer. It is also reported that endophytes play a vital role in the biosynthesis of various metabolites; therefore we believe that endophytes associated with F. indica are of crucial importance in this regard. The present study aims successful isolation, molecular identification of endophytic bacteria and their screening for bioactive metabolites quantification and in vitro pharmacological activities.

Methods

16S rRNA gene sequencing was used for the identification of isolated endophytic bacteria. Methanolic extracts were evaluated for total phenolic contents (TPC), total flavonoids contents (TFC), DPPH free radical scavenging activity, reducing power and total anti-oxidant assays were performed. And also screened for antibacterial and antifungal activities by disc diffusion method and their MIC were calculated by broth dilution method using microplate reader. Further, standard protocols were followed for antileishmanial activity and protein kinase inhibition. Analysis and statistics were performed using SPSS, Table curve and Origin 8.5 for graphs.

Results

Bacterial strains belonging to various genera (Bacillus, Enterobacter, Pantoea, Erwinia and Stenotrophomonas) were isolated and identified. Total phenolic contents and total flavonoids contents varies among all the bacterial extracts respectively in which Bacillus subtilis showed high phenolic contents 243 µg/mg of gallic acid equivalents (GAE) and Stenotrophomonas maltophilia showed high flavonoids contents 15.9 µg/mg quercitin equivalents (QA), total antioxidant capacity (TAC) 37.6 µg/mg of extract, reducing power (RP) 206 µg/mg of extract and 2, 2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging activity with 98.7 μg/mL IC₅₀ value. Although all the extracts tested were active to inhibit growth of selected pathogenic microbes (bacteria and fungi), but significant antibacterial activity was observed against Klebsiella pneumonia and B. subtilis. An Enterobacter cloaca was active against Leishmania tropica with IC₅₀ value of 1.4 µg/mg extracts. B. subtilis and Bacillus tequilensis correspondingly exhibit significant protein kinase inhibition of 47 ± 0.72 and 42 ± 1.21 mm bald zones, indicating anti-infective and antitumor potential.

Conclusions

Our findings revealed that crude extracts of selected endophytic bacteria from F. indica possess excellent biological activities indicating their potential as an important source of antibiotics (antifungal, antibacterial) compounds.

Abstract 5722: Serum Sonic hedgehog (Shh) and interleukin-(IL-6) as dual prognostic biomarkers in progressive metastatic breast cancer

Objectives: Breast cancer (BC) still remains the leading cause of mortality in women worldwide despite substantial developments in diagnosis and therapeutic interventions. Several factors, i.e. different molecular subtypes, biological behaviors, and risk profiles still pose a challenge for prognostication and clinical management. Traditional prognostic and treatment options for BC patients are largely based on careful histological analysis of tumor size, tumor grade, lymph node metastasis and tumor subtypes. Molecular mechanisms play critical roles in developing tumors as well as early and late stage tumor progression of metastatic disease. It is not surprising that many genes are shared amongst the various gene signatures and may have a similar performance in survival risk assessment of the BC patients. Given the production of Shh and IL-6 in the breast tumor microenvironment, we hypothesized that Shh and IL-6 might be detectable in the general circulation. If positive, then it would be clinically useful to identify whether robust expression of serum Shh and IL-6 is correlated with BC prognosis, distant metastasis, lymph node positivity, multidrug resistance as well as self-renewal and maintenance of BC stem cells. We evaluated relative clinical outcome of Shh and IL-6 in the serum from a cohort of patients with untreated early operable and progressive metastatic BC.

Patients and Methods: One hundred and ten breast cancer patients and 30 healthy female volunteers, enrolled in this study and, were evaluated for serum levels of Shh and IL-6 using human ShhN and IL-6 specific enzyme-linked immunoassays. All patients were regularly monitored for event free survival (EFS) and overall survival (OS).

Results: Overall outcome analysis was based on serum Shh and IL-6 levels from 45 early operable and 65 progressive metastatic BC patients. In patients with progressive metastatic BC, serum Shh was elevated in 44% (29 of 65) and IL-6 in 63% (41 of 65). Serum Shh (p=0.0001) and IL-6 (p=0.0001) levels were significantly elevated in BC patients compared to low levels in healthy volunteers, and tended to increase with metastatic progression and lymph node positivity. High serum Shh and IL-6 levels were associated with inferior EFS and OS opposite to negative or lower levels of serum Shh and IL-6. Elevated levels of both serum Shh and IL-6 were mainly observed in hormone refractory BC patients, who had a significantly higher risk of early recurrence, bone metastasis and death.

Conclusion: Elevated levels of serum Shh and IL-6 are associated with increased risk of recurrence and a worse survival for patients with progressive metastatic BC. Further studies are warranted for validating these biomarkers as prognostic and predictive therapeutic tools in a larger patients cohort.

Citation Format: Sonam Akther, Abu Shadat M. Noman, Junayed Nayeem, Zaheer Raihan, Irfanur Rashid, Lutfur Rahman, David Barua, Afrin Sultana, Afsana Shirin, Jannatul Ferdous, Rashed Parag, Mizanur Rahman, Reaz Mahmud, Chandsultana Jerin, Nusrat Jahan, Ayesha Siddiqua, Emran Sabur, Sabrina Alam, Sunanda Baidya, Saiful M. Islam, Syed S. Islam. Serum Sonic hedgehog (Shh) and interleukin-(IL-6) as dual prognostic biomarkers in progressive metastatic breast cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 5722. doi:10.1158/1538-7445.AM2017-5722

Extreme chromosomal instability forecasts improved outcome in ER-negative breast cancer: a prospective validation cohort study from the TACT trial

BACKGROUND

Chromosomal instability (CIN) has been shown to be associated with drug resistance and poor clinical outcome in several cancer types. However, in oestrogen receptor (ER)-negative breast cancer we have previously demonstrated that extreme CIN is associated with improved clinical outcome, consistent with a negative impact of CIN on tumour fitness and growth. The aim of this current study was to validate this finding using previously defined CIN thresholds in a much larger prospective cohort from a randomised, controlled, clinical trial.

PATIENTS AND METHODS

As a surrogate measurement of CIN, dual centromeric fluorescence in situ hybridisation was performed for both chromosomes 2 and 15 on 1173 tumours from the breast cancer TACT trial (CRUK01/001). Each tumour was scored manually and the mean percentage of cells deviating from the modal centromere number was used to define four CIN groups (MCD1-4), where tumours in the MCD4 group were defined as having extreme CIN.

RESULTS

In a multivariate analysis of disease-free survival, with a median follow-up of 91 months, increasing CIN was associated with improved outcome in patients with ER-negative cancer (P trend = 0.03). A similar pattern was seen in ER-negative/HER2-negative cancers (Ptrend = 0.007).

CONCLUSIONS

This prospective validation cohort study further substantiated the association between extreme CIN and improved outcome in ER-negative breast cancers. Identifying such patients with extreme CIN may help distinguish good from poor prognostic groups, and therefore support treatment and risk stratification in this aggressive breast cancer subtype.

Arsenic-induced Histological Alterations in Various Organs of Mice

Deposition of arsenic in mice through groundwater is well documented but little is known about the histological changes of organs by the metalloid. Present study was designed to evaluate arsenic-induced histological alterations in kidney, liver, thoracic artery and brain of mice which are not well documented yet. Swiss albino male mice were divided into 2 groups and treated as follows: Group 1: control, 2: arsenic (sodium arsenite at 10 mg/kg b.w. orally for 8 wks). Group 2 showed marked degenerative changes in kidney, liver, thoracic artery, and brain whereas Group 1 did not reveal any abnormalities on histopathology. We therefore concluded that arsenic induces histological alterations in the tested organs.

Amelogenesis imperfecta: a diagnostic and pathological review with case illustration

Amelogenesis mperfecta is an inherited disorder of enamel development, which results n morphological defects of both the primary and secondary dentition, usually in the absence of systemic involvement. Mutational defects involving the genes that encode for enamel matrix proteins and proteinases are mplicated in this disorder. The phenotypic expression is variable, spanning a spectrum from barely discernible changes to severe aesthetic and functional enamel defects. The specific type and location of the genetic mutation, as well as the mode of inheritance, determine the clinical presentation Clinical recognition and early therapeutic intervention are required for the most successful outcome. An essentia component of the treatment process includes patient counselling and education. Patient management requires a dedicated multi-disciplinary approach. The disorder is reviewed here with emphasis on the clinical significance for the oral healthcare worker. In addition, a case is presented in order to provide an example of treatment panning and dental management.

GENOTYPIC AND PHENOTYPIC CORRELATION AND PATH ANALYSIS FOR LODGING RESISTANCE TRAITS IN BREAD WHEAT (Triticum aestivum L.)

Relationships between the traits associated with lodging resistance in wheat were studied within the period of 1999-2002 at Wheat Research Center, Dinajpur in both F1 and F2 generations of a 9 × 9 diallel cross without reciprocal. The genotypic and phenotypic correlation coefficients studied in F1 and F2 generations were similar with some exceptions. In both F1 and F2 generation, the second internode breaking strength was positively correlated with diameter, wall thickness and unit-stem weight of second internode, and main shoot weight but negatively with plant height and second internode length at both genotypic and phenotypic levels. It was observed from path coefficient analysis in both F1 and F2 generations that the second internode unit-stem weight had high positive direct effect on it’s breaking strength. Main shoot weight, second internode diameter and wall thickness positively influenced breaking strength through its unit-stem weight. Simultaneous selection for the traits contributing to lodging resistant in semi-dwarf wheat might be effective in the improvement of lodging resistance in bread wheat.DOI: http://dx.doi.org/10.3329/bjpbg.v20i2.17036

Transgenic expression of human thymidylate synthase accelerates the development of hyperplasia and tumors in the endocrine pancreas

Thymidylate synthase (TS) is an essential enzyme for DNA synthesis and repair and elevated levels of TS have been identified as an important prognostic biomarker for colorectal cancer and several other common human malignancies. In addition, TS gene expression has been linked with cell-cycle regulation and cell proliferation through the ability of retinoblastoma protein to repress the transcriptional activation of E2F target genes such as TS. Therefore, overproduction of TS could participate in the progression to a neoplastic phenotype. Consistent with this model, a recent study has suggested that ectopic TS expression can induce a transformed phenotype in mammalian cells. To investigate the role of deregulated TS activity in tumor development, we generated transgenic mice that express high levels of catalytically active human TS (hTS) exclusively in the pancreas and low levels of hTS in multiple other tissues. Analyses of pancreatic tissue in TS transgenic mice revealed abnormalities within the endocrine pancreas, ranging from pancreatic islet hyperplasia to the detection of islet cell tumors. Overexpression of hTS in murine islets provides a new model to study genetic alterations associated with the progression from normal cells to hyperplasia to islet cell tumors, and suggests that this mouse model may be useful for regulating TS activity in vivo for development of cancer prevention and new therapies.

EGFRvIII undergoes activation-dependent downregulation mediated by the Cbl proteins

The overexpression or mutation of tyrosine kinases (TKs), such as the epidermal growth factor receptor (EGFR), can lead to the development of cancer. The most common mutation of the EGFR in glioblastomas is the deletion of exons 2-7 known as the EGFRvIII. This mutant receptor cannot bind EGF but, instead, is constitutively active. The Cbl family of ubiquitin ligases (Cbl, Cbl-b, and Cbl-c) targets the activated EGFR for degradation. As the EGFRvIII is transforming, we investigated whether it could be downregulated by the Cbl proteins. The overexpression of all three Cbl proteins resulted in the ubiquitination and degradation of the EGFRvIII. As with the wild-type EGFR, the TK-binding domain and the RING finger of Cbl-b are sufficient for the downregulation of the EGFRvIII. Also, we found that Cbl-b is recruited to the EGFRvIII and inhibits the transformation of NIH 3T3 cells by the EGFRvIII. Mutation of the Cbl-binding site (Y1045F) in the EGFRvIII inhibits its ubiquitination and downregulation by Cbl-b and enhances its ability to transform. Furthermore, the EGFR TK inhibitor, AG 1478, prevents the downregulation of the EGFRvIII by the Cbl proteins and antagonizes the ability of an immunotoxin directed against the EGFRvIII to kill cells expressing this receptor. In conclusion, the EGFRvIII does not transform by escaping regulation by Cbl proteins and this activation-induced downregulation of the EGFRvIII has an important role in mediating the toxicity of anti-EGFRvIII immunotoxins.

An efficient in vitro procedure for micropropagation and generation of somaclones of rose scented Pelargonium

Efficient protocols have been established for both direct and indirect regeneration of plants in Pelargonium graveolens Indian cultivar Hemanti (Algerian type). Murashige and Skoog's (MS) medium [T. Murashige, F. Skoog, A revised medium for rapid growth and bioassays with tobacco tissue cultures. Physiol. Plant. 15 (1962) 473-497] supplemented with 5.0 mg/l kinetin and 1.0 mg/l NAA was optimal for direct regeneration of plants from leaf explants while 8.0 mg/l kinetin and 1.0 mg/l NAA proved optimum for nodal explants for maximum number of shoots per explant. Callus induction was observed from nodal explants on MS medium supplemented with 10 mg/l kinetin and 1.0 mg/l NAA. Callus on further transfer to MS medium with 0.5 mg/l BAP and 0.1 mg/l NAA exhibited regeneration of maximum number of shoots. In vitro grown shoots of both direct and indirect origin rooted within 7-10 days following transfer to half strength MS medium with 1.0 mg/l IBA. Plantlets were acclimatized under glass house conditions with 90% survival. Randomly selected 85 individual Calliclones were subjected to field trial with 85-95% survival for two successive years along with control in randomized block design with three replicates. Screening of these calliclones revealed two distinct morphotypes, one with parental type highly dentated leaves (HDL) and the other with less dentated, round leaves (LDL). Only HDL calliclones flowered under field conditions. The LDL clones differed in several herb related agronomic characteristics such as plant height, herb yield, canopy size and number of branches per plant from the parental type as well as from the parent, which seems advantageous for commercial exploitation of such clones. The HDL clones closely resemble the parent in having higher content of citronellol than geraniol while the LDL clones contain almost equal contents of citronellol and geraniol in their essential oils as revealed by gas chromatography analysis. It is noticeable that the variability both in terms of agronomic characters and essential oil profiles among the clones were stable over 2 years of field trials.

The distribution of Ascaris lumbricoides in human hosts: a study of 1765 people in Bangladesh

The Ascaris lumbricoides expelled by 1765 people in a poor urban community in Bangladesh were recovered and counted after the subjects had been treated with pyrantel pamoate. The subjects were divided into 22 classes by age and sex (mean n = 80) to examine how prevalence, mean worm burdens and measures of aggregation of worms varied with age and between the sexes, and to see how a measure of aggregation, k, calculated in 3 ways (by maximum likelihood, from moments, or from the percentage uninfected) compared with an empirical aggregation index (the percentage of subjects who expelled an arbitrary 80% of all worms) and with the proportion who were moderately to heavily infected (defined as > or = 15 worms). The prevalence of infection ranged from 64% to 95%, mean worm burdens ranged from 7 to 23 worms, and k ranged from 0.3 to 1.2. There were significant differences between adult males and females in the prevalence of infection, mean worm burdens and measures of aggregation, differences which are probably driven more by behaviour than immunity. The parameter k was better described in terms of the proportion who were moderately to heavily infected (linear; range 0.15-0.58) than by the empirical aggregation index (non-linear; range 0.30-0.49).

Synchronization of two passively mode-locked erbium-doped fiber lasers by an acousto-optic modulator and grating scheme

We synchronize two passively mode-locked erbium-doped fiber lasers by adjusting only the cavity length to correct both the repetition rate and the phase. The interlaser jitter is less than 6 ps (1.3 times the pulse width) and is extracted from the cross correlation of the two lasers. The lock can be maintained for extended periods of time. These results are obtained by use of a novel acousto-optic-modulator-grating scheme, which provides an equivalent of 300 microm in cavity length tuning with a bandwidth of 10 kHz. These parameters are 30 times the length and 10 times the bandwidth of a typical piezoelectric transducer.

High-power erbium-doped fiber laser mode locked by a semiconductor saturable absorber

Using an erbium-doped fiber laser (EDFL) passively mode locked by a semiconductor saturable absorber, we generate 5.5-ps pulses of a 2.3-nJ/pulse, which are more than three times higher in energy than for other reported EDFL's. We show that, by introduction of a linear loss element within the cavity, multiple pulsing behavior at high pump powers can be suppressed. We also determine the saturable-absorber characteristics-absorbance versus wavelength near band gap-that are necessary to produce short mode-locked pulses.

Validity of the coupled-oscillator model for laser-array dynamics

We show that the coupled-oscillator model accurately describes the dynamics of laser arrays. Excellent qualitative and quantitative agreement is obtained between this model and the results of experiments on Nd:YAG laser arrays. Recent claims of instantaneous phase locking are shown to be in error.

Improved coupled-mode theory for the dynamics of semiconductor laser arrays

We present an improved coupled-mode model to describe the dynamics of weakly index-guided semiconductor laser arrays. The model is derived from a partial differential equation model that includes the effects of carrier diffusion and gain guiding. Results from the two models are compared, and good qualitative and quantitative agreement is obtained.

[Influence of the speed of spheronization on the physical properties and dissolution availability of theophylline minigranules prepared by extrusion-spheronization]

From the minigranules of the theophylline-based that prepared by extrusion-spheronization, the authors have envisaged the study of one of the parameters of operation (spheronizer speed) on the physical properties and lyoavailability of the active ingredient. It emerges that there is a clear influence of that parameters on the particle size distribution, the hardness, the friability, the density and the lyoavailability.