Tetragonal to triclinic structural transition in the prototypical CeScSi induced by a two-step magnetic ordering: a temperature-dependent neutron diffraction study of CeScSi, CeScGe and LaScSi

An investigation on the ground state magnetism of CeScSi, CeScGe (tetragonal CeScSi-type, tI12, space group I4/mmm) by temperature-dependent powder neutron diffraction has been carried out, as debated and controversial data regarding the low temperature magnetic behaviours of these two compounds were reported. Our studies reveal that, while cooling, long-range magnetic ordering in CeScSi and CeScGe takes place by a two-step process. A first transition leads to a magnetic structure with the Ce moments aligned ferromagnetically onto two neighbouring tetragonal basal a-b planes of the CeScSi-type structure; the double layers are then antiferromagnetically coupled to each other along the c-axis. The transition temperature associated with the first ordering is T _N ~ 26 K and T _N ~ 48 K for the silicide and the germanide, respectively. Here the spin directions are rigorously confined to the basal plane, with values of the Ce magnetic moments of μ _Ce  =  0.8-1.0 μ _B. A second magnetic transition, which takes place at slightly lower temperatures, results in a canting of the ordered magnetic moments out of the basal plane which is accompanied by an increase of the magnetic moment value of Ce to μ _Ce  =  1.4-1.5 μ _B. Interestingly, the second magnetic transition leads to a structural distortion in both compounds from the higher-symmetry tetragonal space group I4/mmm to the lower-symmetry and triclinic I-1 (non-standard triclinic). Magnetic symmetry analysis shows that the canted structure would not be allowed in the I4/mmm space group; this result further confirms the structural transition. The transition temperatures T _S from I4/mmm to I-1 are about 22 K in CeScSi and 36 K in CeScGe, i.e. well below the temperature of the first onset of antiferromagnetic order observed in this work (or below the ordering temperature, previously reported as either T _C or T _N). This result, along with the synchronism of the magnetic and structural transitions, suggests a magnetostructural origin of this structural distortion. We have also carried out powder neutron diffraction for LaScSi as a non-magnetically-ordering reference compound and compared the results with those of CeScSi and CeScGe compounds.

Modelling of microalgal growth and lipid production in Dunaliella tertiolecta using nitrogen-phosphorus-potassium fertilizer medium in sintered disk chromatographic glass bubble column

A comprehensive mathematical model involving NPK-10:26:26 fertilizer, NaCl, NaHCO3, light and temperature operating variables for Dunaliella tertiolecta cultivation is formulated to predict microalgae-biomass and lipid productivity. Proposed model includes Monod/Andrews kinetics for the absorption of essential nutrients into algae-biomass and Droop model involving internal nutrient cell quota for microalgae growth, assuming algae-biomass is composed of sugar, functional-pool and neutral-lipid. Biokinetic model parameters are determined by minimizing the residual-sum-of-square-errors between experimental and computed microalgae-biomass and lipid productivity using genetic algorithm. Developed model is validated with the experiments of Dunaliella tertiolecta cultivation using air-agitated sintered-disk chromatographic glass-bubble column and the effects of operating variables on microalgae-biomass and lipid productivity is investigated. Finally, parametric sensitivity analysis is carried out to know the sensitivity of model parameters on the obtained results in the input parameter space. Proposed model may be helpful in scale-up studies and implementation of model-based control strategy in large-scale algal cultivation.

Effect of tanniferous leaf meal based multi-nutrient blocks on feed intake, hematological profile, immune response, and body weight changes in Haemonchus contortus infected goats

Aim:

The aim was to assess the effect of multi nutrient block (MNB) supplementation with and without tanniferous leaf meal mixture on feed intake, hematological profile, immune response, and body weight changes of goats that were experimentally infected with Haemonchus contortus.

Materials and Methods:

Total 12 adult male goats of similar age and body weight (26.49±0.87) were allocated in 3 groups in completely randomized design. MNB supplemented in first two groups i.e. in T₁ (no infection) and T₂ (H. contortus infection @ 1500 L₃/goat) group, while, MNB-condensed tannin (CT) supplemented in T₃ (H. contortus infection @ 1500 L₃/goat + CT source). All goats were fed concentrate mixture @ 100 g/day/goat, ad lib wheat straw and MNB or MNB-CT to meet their requirement for maintenance. Body weights were recorded and blood and fecal samples were collected at 0 day and thereafter at 15 days intervals for a period of 75 days for the assessment of body weight changes, hematological profile and H. contortus loads. Both humoral and cell-mediated immune (CMI) response were assessed at the end of feeding trial.

Results:

Mean hemoglobin and packed cell volume (PCV) levels were found to be highest (p<0.001, p<0.05) in T₁ group followed by T₃ group and lowest values were observed in T₂ group. However, The PCV values between T₁ and T₃ groups were found to be statistically non-significant (p<0.05). The humoral and CMI response were significantly (p<0.036) higher in T₃ group as compared to T₂ group. MNB-CT supplementation significantly (p<0.001) reduced fecal egg counts in T₃ group as compared to MNB supplemented T₂ group.

Conclusion:

Supplementation of MNB-CT could be used as an alternative sustainable method to control H. contortus and maintained health status and performance of goats in face of parasitic challenge.

Prevalence of lymphatic filariasis in a tea garden worker population of Dibrugarh (Assam), India after six rounds of mass drug administration

BACKGROUND & OBJECTIVES

Lymphatic filariasis (LF) is endemic in the state of Assam and mass drug administration (MDA) programme for LF elimination is being implemented in the state since 2004. A study on prevalence of microfilaria (mf), disease endemicity and vector infection was carried out in a tea garden population of Dibrugarh, Assam (India) to assess the effect of ongoing MDA programme on elimination of LF.

METHODS

Finger prick thick blood smears (20 mm3) were made from individuals aged ≥2 yr old during night blood survey in between 2000-0000 hrs during the period of November 2012 to February 2013. Blood smears were dehaemoglobinised, stained with Giemsa and examined under microscope for presence of mf. Indoor resting mosquitoes were collected during 0600-1000 hrs and female Culex quinquefasciatus were dissected and examined under microscope for larval forms of the parasite.

RESULTS

A total of 634 blood smears were collected and screened for mf and 47 (7.41%) individuals were found microfilaraemic, with predominance of males (74.5%). Highest mf rate (20.0%) was seen in the males of 30-39 yr age group while in females, age group of 10-19 yr recorded maximum mf rate (5.48%). Entomological collection and dissection of Cx. quinquefasciatus revealed presence of larval stages of the parasite and infection and infectivity rates recorded were 13.20 and 3.70%, respectively. Chronic clinical manifestations in the form of elephantiasis and hydrocele were recorded in 33 (5.73%) subjects of the 575 examined.

INTERPRETATION & CONCLUSION

Mass drug administration data showed six rounds of MDA with drug distribution coverage in between 63.42 and 95.93% in the study population. Out of 634 individuals examined 47 were found microfilaraemic giving an overall infection rate of 7.41%. Mosquito vector infection and infectivity rates were 13.20 and 3.70%, respectively. Presence of high mf rate, vector infectivity rate and clinical cases in the study population after six rounds of MDA warrants concerted efforts to be made for effective implementation and monitoring of MDA for success of LF elimination programme.

Microfilarial periodicity of Wuchereria bancrofti in Assam, Northeast India

BACKGROUND & OBJECTIVES

Wuchereria bancrofti has shown nocturnal periodicity in India and other endemic countries of the world except pacific regions where non-periodic or diurnal sub-periodic forms have been reported. Presence of sub-periodic form of W. bancrofti in Andaman and Nicobar Islands, India and a case report of sub- periodic form of W. bancrofti from Mysore, India provide basis for exploring the periodicity pattern of microfilaria of W. bancrofti prevalent in Assam, Northeastern region of India. State of Assam has unique geographical location as its Northeastern region shares international boundaries with Nepal, China, Bhutan, Myanmar and Bangladesh. Evolutionary association of W. bancrofti found in Assam is not known and possibility of its link with W. bancrofti form, prevalent in neighbouring countries may not be ruled out. Hence, this study was undertaken to know the microfilarial periodicity of W. bancrofti in Assam.

METHODS

Ten microfilaria positive adult male individuals having moderate to high microfilaraemia were selected. Informed written consent from each participant was obtained. The presence of microfilaria was observed at two hourly intervals over a period of 24 h using 50 μl of finger prick peripheral blood samples. Peripheral blood smears were processed, stained and examined under microscope and microfilaria counts were recorded.

RESULTS

Data collected were calculated and analyzed using modified statistical method, and the periodicity curve was prepared. Typical nocturnal periodicity was observed at a peak time of 0003 hrs with a periodicity index of 136.2.

INTERPRETATION & CONCLUSION

Analysis of the data revealed nocturnal periodicity of the W. bancrofti prevalent in the Assam with peak periodicity about one hour ahead of the other states in India. Findings will be helpful in evaluation and monitoring of ongoing MDA programme for elimination of LF in Assam.

Infections do not predict shedding in co-infections with two helminths from a natural system

Given the health and economic burden associated with the widespread occurrence of co-infections in humans and agricultural animals, understanding how coinfections contribute to host heterogeneity to infection and transmission is critical if we are to assess risk of infection based on host characteristics. Here, we examine whether host heterogeneity to infection leads to similar heterogeneity in transmission in a population of rabbits single and co-infected with two helminths and monitored monthly for eight years. Compared to single infections, co-infected rabbits carried higher Trichostrongylus retortaeformis intensities, shorter worms with fewer eggs in utero, and shed similar numbers of parasite eggs. In contrast, the same co-infected rabbits harbored fewer Graphidium strigosum with longer bodies and more eggs in utero, and shed more eggs of this helminth. A positive density-dependent relationship between fecundity and intensity was found for T. retortaeformis but not G. strigosum in co-infected rabbits. Juvenile rabbits contributed to most of the infection and shedding of T. retortaeformis, while adult hosts were more important for G. strigosum dynamics of infection and transmission, and this pattern was consistent in single and co-infected individuals. This host-parasite system suggests that we cannot predict the pattern of parasite shedding during co-infections based on intensity of infection alone. We suggest that a mismatching between susceptibility and infectiousness should be expected in helminth coinfections and should not be overlooked.

Randomized phase II study of carboplatin and etoposide with or without obatoclax mesylate in extensive-stage small cell lung cancer

OBJECTIVE

This randomized phase II study assessed the efficacy and safety of obatoclax mesylate, a small-molecule Bcl-2 inhibitor, added to carboplatin/etoposide chemotherapy as initial treatment for extensive-stage small-cell lung cancer (ES-SCLC).

MATERIALS AND METHODS

Chemotherapy-naïve subjects with ES-SCLC and Eastern Cooperative Oncology Group performance status (ECOG PS) 0-2 received carboplatin/etoposide with (CbEOb) or without (CbE) obatoclax for up to six cycles. Responders to CbEOb could receive maintenance obatoclax until disease progression. The primary endpoint was objective response rate (ORR).

RESULTS

155 subjects (median age 62, 58% male, 10% ECOG PS 2) were treated with CbEOb (n=77) or CbE (n=78); 65% and 59% of subjects, respectively, completed six cycles. ORR was 62% with CbEOb versus 53% with CbE (1-sided p=0.143). Clinical benefit (ORR+ stable disease) trended better with CbEOb (81% versus 68%; p=0.054). Median progression-free survival (PFS) and overall survival (OS) were 5.8 months (95% confidence interval [CI]: 5.3-6.5) and 10.5 months (8.9-13.8) with CbEOb and 5.2 months (95% CI: 4.1-5.7) and 9.8 months (7.2-11.2) with CbE. Median OS was 10.5 months (95% CI: 8.9-13.8) and 9.8 months (7.2-11.2) with a nonsignificant hazard ratio for OS, 0.823; 1-sided p=0.121. Grade 3/4 adverse events (AEs) were primarily hematologic and similar in frequency between treatment arms. Obatoclax-related somnolence and euphoria were grade 1/2, transient, and did not require treatment discontinuation.

CONCLUSION

Obatoclax was well tolerated when added to carboplatin/etoposide in first-line treatment of ES-SCLC, but failed to significantly improve ORR, PFS, or OS.

Length weight relationship and condition factor of selected freshwater fish species found in river Ganga, Gomti and Rapti, India

This study is based on the length-weight relationships (LWRs) of 2148 fishes, belonging to 8 families, 12 genera and 15 freshwater fish species (Wallago attu, Rite rita, Sperato seenghala, Sperota aor, Mostacembalus armatus, Macrognathus puncolus, Gudusia chopra, Clupisoma garua, Puntius sophore, Puntius ticto, Rasbora daniconius, Amblypharyngodon mole, Chanda noma, Colisa fociatus and Colisa sota) captured from river Ganga, Gomti and Rapti during May 2011 to March 2012. The growth coefficient (b) values varied between 1.30 and 3.07, with the mean b = 2.03 at p< 0.001. The condition factor (K) varied considerably from 0.76 and 2.95, with a mean K = 1.43 which may be attributed to different environmental conditions of the river basin. The objective was to evaluate the pattern of LWRs and condition factors of the freshwater fish species of the main Ganga and tributaries which serves as baseline for other tropical Indian rivers and tributaries.

Immuno-epidemiology of chronic bacterial and helminth co-infections: observations from the field and evidence from the laboratory

Co-infections can alter the host immune responses and modify the intensity and dynamics of concurrent parasitic species. The extent of this effect depends on the properties of the system and the mechanisms of host-parasite and parasite-parasite interactions. We examined the immuno-epidemiology of a chronic co-infection to reveal the immune mediated relationships between two parasites colonising independent organs, and the within-host molecular processes influencing the dynamics of infection at the host population level. The respiratory bacterium, Bordetella bronchiseptica, and the gastrointestinal helminth, Graphidium strigosum, were studied in the European rabbit (Oryctolagus cuniculus), using long-term field data and a laboratory experiment. We found that 65% of the rabbit population was co-infected with the two parasites; prevalence and intensity of co-infection increased with rabbit age and exhibited a strong seasonal pattern with the lowest values recorded during host breeding (from April to July) and the highest in the winter months. Laboratory infections showed no significant immune-mediated effects of the helminth on bacterial intensity in the lower respiratory tract but a higher abundance was observed in the nasal cavity during the chronic phase of the infection, compared with single bacterial infections. In contrast, B. bronchiseptica enhanced helminth intensity and this was consistent throughout the 4-month trial. These patterns were associated with changes in the immune profiles between singly and co-infected individuals for both parasites. This study confirmed the general observation that co-infections alter the host immune responses but also highlighted the often ignored role of bacterial infection in helminth dynamics. Additionally, we showed that G. strigosum had contrasting effects on B. bronchiseptica colonising different parts of the respiratory tract. At the host population level our findings suggest that B. bronchiseptica facilitates G. strigosum infection, and re-infection with G. strigosum assists in maintaining bacterial infection in the upper respiratory tract and thus long-term persistence.

Network model of immune responses reveals key effectors to single and co-infection dynamics by a respiratory bacterium and a gastrointestinal helminth

Co-infections alter the host immune response but how the systemic and local processes at the site of infection interact is still unclear. The majority of studies on co-infections concentrate on one of the infecting species, an immune function or group of cells and often focus on the initial phase of the infection. Here, we used a combination of experiments and mathematical modelling to investigate the network of immune responses against single and co-infections with the respiratory bacterium Bordetella bronchiseptica and the gastrointestinal helminth Trichostrongylus retortaeformis. Our goal was to identify representative mediators and functions that could capture the essence of the host immune response as a whole, and to assess how their relative contribution dynamically changed over time and between single and co-infected individuals. Network-based discrete dynamic models of single infections were built using current knowledge of bacterial and helminth immunology; the two single infection models were combined into a co-infection model that was then verified by our empirical findings. Simulations showed that a T helper cell mediated antibody and neutrophil response led to phagocytosis and clearance of B. bronchiseptica from the lungs. This was consistent in single and co-infection with no significant delay induced by the helminth. In contrast, T. retortaeformis intensity decreased faster when co-infected with the bacterium. Simulations suggested that the robust recruitment of neutrophils in the co-infection, added to the activation of IgG and eosinophil driven reduction of larvae, which also played an important role in single infection, contributed to this fast clearance. Perturbation analysis of the models, through the knockout of individual nodes (immune cells), identified the cells critical to parasite persistence and clearance both in single and co-infections. Our integrated approach captured the within-host immuno-dynamics of bacteria-helminth infection and identified key components that can be crucial for explaining individual variability between single and co-infections in natural populations.

Infections with different infecting agents can alter the immune response against any one parasite and the relative abundance and persistence of the infections within the host. This is because the immune system is not compartmentalized but acts as a whole to allow the host to maintain control of the infections as well as repair damaged tissues and avoid immuno-pathology. There is no comprehensive understanding of the immune responses during co-infections and of how systemic and local mechanisms interact. Here we integrated experimental data with mathematical modelling to describe the network of immune responses of single and co-infection by a respiratory bacterium and a gastrointestinal helminth. We were able to identify key cells and functions responsible for clearing or reducing both parasites and showed that some mechanisms differed between type of infection as a result of different signal outputs and cells contributing to the immune processes. This study highlights the importance of understanding the immuno-dynamics of co-infection as a host response, how immune mechanisms differ from single infections and how they may alter parasite persistence, impact and abundance.

Snapshot of spatio-temporal cytokine responses to single and co-infections with helminths and bacteria

Cytokines play a key role in maintaining communication between organs and in so doing modulate the interaction between concurrent infections. The extent of these effects depends on the properties of the organ infected and the intensity and type of infections. To determine systemic bystander effects among organs, IFN-γ, IL-4 and IL-10 gene expression was quantified at 7 days post-challenge in directly infected and uninfected organs during single and co-infections with the respiratory bacterium Bordetella bronchiseptica and the gastrointestinal helminths Graphidium strigosum and Trichostrongylus retortaeformis. Results showed that cytokine expression in a specific organ was influenced by the type of infection occurring in another organ, and this bystander effect was more apparent in some organs than others. Within the same organ the relative cytokine expression was consistent across infections, although some cytokines were more affected by bystander effects than others. For the infected gastrointestinal tract, a stronger cytokine response was observed in the tissue that harbored the majority of helminths (i.e. duodenum and fundus). Overall, co-infections altered the intensity but to a lesser extent the relative cytokine profile against the focal infection, indicating clear bystander effects and low organ compartmentalization. However, organs appear to actively modulate cytokine expression to avoid potential immuno-pathological consequences.

Instability range of microsolvated multiply charged negative ions: prediction from detachment energy of stable hydrated clusters

We have presented a first-principle theory-based derivation of an exact expression for the solvent number-dependent electron-detachment energy of a solvated species in the thermodynamic limit. We also propose a generalized equation bridging the electron detachment energies for small and infinitely large clusters, thus providing a new route to calculate the ionization potential of a negatively charged ion from the electron-detachment energies of its stable hydrated clusters. Most importantly, it has the ability to predict the instability range of microhydrated anions. The calculated results for the ionization potential for a number of ions are found to be in good agreement with the available experimental results, and the predicted instability range for the doubly charged anions SO₄²⁻ and C₂O₄²⁻ is also consistent with experimental and ab initio results.

2-Azetidinone--a new profile of various pharmacological activities

2-azetidinone, a β-lactam four member heterocyclic compound involved in research aimed to evaluate new products that possess interesting biological activities. These compounds reported for their antimicrobial and antifungal activities. Successful introduction of aztreonam as a potent inhibitor of cephalosporinase and ezetimibe as a cholesterol absorption inhibitor proved potential of 2-azetidinone moiety. Subsequently 2-azetidinones were highlighted as a potent mechanism based inhibitor of several enzymes like human tryptase, chymase, thrombin, leukocyte elastase, human cytomegalovirus protease and serine protease enzyme. These derivatives also known to possess antitubercular, anti-inflammatory, antitumor, anti-HIV, antiparkinsonian, antidiabetic and vasopressin V1a antagonist activity. The present review article focuses on the pharmacological profile of 2-azetidinones with their potential activities.

Immune regulation of a chronic bacteria infection and consequences for pathogen transmission

Background

The role of host immunity has been recognized as not only playing a fundamental role in the interaction between the host and pathogen but also in influencing host infectiousness and the ability to shed pathogens. Despite the interest in this area of study, and the development of theoretical work on the immuno-epidemiology of infections, little is known about the immunological processes that influence pathogen shedding patterns.

Results

We used the respiratory bacterium Bordetella bronchiseptica and its common natural host, the rabbit, to examine the intensity and duration of oro-nasal bacteria shedding in relation to changes in the level of serum antibodies, blood cells, cytokine expression and number of bacteria colonies in the respiratory tract. Findings show that infected rabbits shed B. bronchiseptica by contact up to 4.5 months post infection. Shedding was positively affected by number of bacteria in the nasal cavity (CFU/g) but negatively influenced by serum IgG, which also contributed to the initial reduction of bacteria in the nasal cavity. Three main patterns of shedding were identified: i- bacteria were shed intermittently (46% of individuals), ii- bacteria shedding fell with the progression of the infection (31%) and iii- individuals never shed bacteria despite being infected (23%). Differences in the initial number of bacteria shed between the first two groups were associated with differences in the level of serum antibodies and white blood cells. These results suggest that the immunological conditions at the early stage of the infection may play a role in modulating the long term dynamics of B. bronchiseptica shedding.

Conclusions

We propose that IgG influences the threshold of bacteria in the oro-nasal cavity which then affects the intensity and duration of individual shedding. In addition, we suggest that a threshold level of infection is required for shedding, below this value individuals never shed bacteria despite being infected. The mechanisms regulating these interactions are still obscure and more studies are needed to understand the persistence of bacteria in the upper respiratory tract and the processes controlling the intensity and duration of shedding.

Influence of an enzyme cocktail and phytase individually or in combination in Ven Cobb broiler chickens

1. An experiment (21 d) was conducted to determine if the response of chicks to a cocktail of xylanase, amylase, and protease (XAP) or Escherichia coli-derived phytase individually or in combination when fed a nutritionally marginal maize-soybean meal diet is age-dependent. 2. A total of 250 one-day-old Ven Cobb broiler chicks were allocated to 5 dietary treatments in a randomised complete block design. The treatments were as follows: (1) positive control with supplemental inorganic P; (2) negative control (NC) marginal in P and ME; (3) NC plus XAP to provide (per kg of diet) 650, 1650 and 4000 U of xylanase, amylase, and protease, respectively; (4) NC plus phytase added to provide 1000 phytase units/kg; and (5) NC plus a combination of XAP and phytase. 3. Low ME and P in the NC diet depressed weight gain and gain:feed. A cocktail of XAP alone did not improve performance, but phytase supplementation improved weight gain. The enzymes were additive in their effects on growth performance. 4. The enzymes had no effect on ileal digestible energy. Ileal N digestibility was higher in diets with XAP or phytase individually compared with NC. Both phytase and XAP individually and in combination improved ileal P digestibility compared with NC. 5. Total tract nutrient retention and ME increased as the birds grew older. There were age x diet interactions in total tract retention of P and Ca; improvement in P retention due to phytase use decreased by 50% as the chicks matured. 6. The current study shows that a combination of XAP and phytase improved performance, but the enhancement in performance appears to be due mainly to phytase. Both XAP and phytase were effective in improving P digestibility and retention of chicks receiving nutritionally marginal maize-soybean meal. 7. The data also showed that the chicks benefited more from the enzyme addition at a younger age and that the contribution of the enzymes to nutrient retention decreased with age in chickens.

Antigenic Variation among Bordetella: Bordetella bronchiseptica strain MO149 expresses a novel o chain that is poorly immunogenic

The O chain polysaccharide (O PS) of Bordetella bronchiseptica and Bordetella parapertussis lipopolysaccharide is a homopolymer of 2,3-diacetamido-2,3-dideoxygalacturonic acid (GalNAc3NAcA) in which some of the sugars are present as uronamides. The terminal residue contains several unusual modifications. To date, two types of modification have been characterized, and a survey of numerous strains demonstrated that each contained one of these two modification types. Host antibody responses against the O PS are directed against the terminal residue modifications, and there is little cross-reactivity between the two types. This suggests that Bordetella O PS modifications represent a means of antigenic variation. Here we report the characterization of the O PS of B. bronchiseptica strain MO149. It consists of a novel two-sugar repeating unit and a novel terminal residue modification, with the structure Me-4-alpha-L-GalNAc3NAcA-(4-beta-D-GlcNAc3NAcA-4-alpha-L-GalNAc3NAcA-)(5-6)-, which we propose be defined as the B. bronchiseptica O3 PS. We show that the O3 PS is very poorly immunogenic and that the MO149 strain contains a novel wbm (O PS biosynthesis) locus. Thus, there is greater diversity among Bordetella O PSs than previously recognized, which is likely to be a result of selection pressure from host immunity. We also determine experimentally, for the first time, the absolute configuration of the diacetimido-uronic acid sugars in Bordetella O PS.

Heterotransplant mouse model cohorts of human malignancies: A novel platform for Systematic Preclinical Efficacy Evaluation of Drugs (SPEED)

Advances in molecular biology demonstrate that cancer is heterogeneous disease necessitating a personalized management approach. This is introducing a paradigm shift in clinical trial designs where molecular characterization of cancers is assuming importance equal to (or even more than) the traditional histologic diagnosis as the eligibility criterion for randomized clinical trials of new therapies. Recommendations have been made to gather the molecular information from clinical phase II trials distinguishing responding from non responding tumors for subsequent planning of large scale phase III trials. However by the time we reach phase II level, more than a billion dollars apart from years of research have been invested. It would be therefore prudent to conceptualize laboratory based platforms to obtain the proof of concept as early as possible, even before embarking upon the pivotal clinical trials. In this regard, we hereby propose and detail a novel preclinical platform incorporating the existing mouse models to address the issue of tumor heterogeneity in a systematic manner through creation of a setting similar to phase II trials in human patients. By providing critical information about a drug's efficacy and the molecular determinants of response early on, this platform would potentially provide a solid foundation to build avant-garde clinical trials integrating recent advances in molecular medicine.

Effect of change in symptoms, respiratory status, nutritional profile and quality of life on response to treatment for advanced non-small cell lung cancer

INTRODUCTION

Quality of life (QOL), and pulmonary and nutritional parameters are important outcome measures during treatment of lung cancer; however, the effect of chemotherapy on these factors and their relationship with clinical response is unclear.

METHODS

Patients with non-small cell lung cancer (NSCLC) were evaluated for symptom profile, nutritional status (using anthropometry), pulmonary functions by spirometry and six minute walk distance (6 MWD), and QOL using the WHO-QOL Bref 26 questionnaire, before and after chemotherapy.

RESULTS

Forty-four patients were studied (mean (SD) age, 55 (10) years, 75% males). The majority (98%) had stage III or IV disease and 72% were current / ex-smokers with median pack-years of 27.0 (range, 0.5-90). Some 61% had a Karnofsky Performance Scale (KPS) 70 or 80. The commonest symptoms were coughing, dyspnea, chest pain, anorexia and fever (79%, 72%, 68%, 57% and 40%, respectively). The mean (SD) 6 MWD was 322.5 (132.6) meters. The mean (SD) percentage forced vital capacity (FVC %), and forced expiratory volume in one second (FEV1 %) were 64.7 (18.8) and 57.8 (19.4), respectively. The mean (SD) QOL scores for the physical, psychological, social, and environmental domains were 52.9 (20.5), 56.1 (17.9), 64.5 (21.8), 57.1 (16.6), respectively. Fourteen patients (32%) responded to chemotherapy. Non-responders had significantly higher baseline occurrence of fever, anorexia, and weight loss, higher pack-years of smoking and poorer KPS compared to responders. Overall, chemotherapy caused significant decline in the frequency of coughing, dyspnea, chest pain, fever, anorexia, weight loss, and improvement in hemoglobin and albumin levels. There was no significant improvement in pulmonary functions, nutritional status, or QOL scores after treatment.

CONCLUSIONS

Lung cancer patients have a poor QOL. Although chemotherapy provides significant symptomatic benefit, this does not translate into similar benefit in respiratory and nutritional status or QOL. Patients with constitutional symptoms, higher smoking burden, and poor KPS are less likely to respond to chemotherapy. Management of NSCLC must include strategies to improve various aspects of QOL, nutritional status and pulmonary reserve to achieve comprehensive benefit.

Abstract 1599: Oral epithelium as a surrogate tissue for assessing smoking-induced molecular alterations in lungs

Background: Because lungs and oral cavity are both exposed to tobacco-carcinogens, we hypothesized that the oral epithelium undergoes molecular alterations similar to those in other airway areas and therefore may be used as a surrogate tissue to assess tobacco-induced molecular alterations in lungs.

Methods: Promoter methylation of p16 and FHIT genes was analyzed in 127 chronic smokers enrolled in a prospective randomized placebo-controlled chemoprevention trial with 1,774 samples from oral and bronchial brushes (baseline and 3-months after intervention) using methylation-specific PCR (MSP). Methylation patterns in oral tissues were correlated with bronchial methylation indices (methylated sites/total sites per subject).

Results: At baseline, promoter methylation was observed in 23%, 17%, and 35% of the bronchial tissues for p16, FHIT, and any of the two genes, respectively, which is comparable to 19%, 15%, and 31% observed in the oral tissues. Among the 125 individuals with available baseline data from both oral and bronchial tissues, strong correlations were observed between tissues from the two organ sites (P &lt; 0.0001 for both p16 and FHIT genes). Among the 39 individuals with oral tissue methylation in any of the two genes, the mean bronchial methylation index was 0.53 (±0.29) compared to only 0.27 (±0.26) for the 86 cases without oral tissue methylation (P &lt; 0.0001). Similar correlations were also observed in samples obtained at 3 months after chemopreventive intervention.

Conclusions: Oral epithelium may be used as a surrogate tissue to assess tobacco-induced molecular damages in lungs, which has potential implications in lung cancer prevention trials.

Delta DNMT3B variants regulate DNA methylation in a promoter-specific manner

DNA methyltransferase 3B (DNMT3B) is critical in de novo DNA methylation during development and tumorigenesis. We recently reported the identification of a DNMT3B subfamily, DeltaDNMT3B, which contains at least seven variants, resulting from alternative pre-mRNA splicing. DeltaDNMT3Bs are the predominant expression forms of DNMT3B in human lung cancer. A strong correlation was observed between the promoter methylation of RASSF1A gene but not p16 gene (both frequently inactivated by promoter methylation in lung cancer) and expression of DeltaDNMT3B4 in primary lung cancer, suggesting a role of DeltaDNMT3B in regulating promoter-specific methylation of common tumor suppressor genes in tumorigenesis. In this report, we provide first experimental evidence showing a direct involvement of DeltaDNMT3B4 in regulating RASSF1A promoter methylation in human lung cancer cells. Knockdown of DeltaDNMT3B4 expression by small interfering RNA resulted in a rapid demethylation of RASSF1A promoter and reexpression of RASSF1A mRNA but had no effect on p16 promoter in the lung cancer cells. Conversely, normal bronchial epithelial cells with stably transfected DeltaDNMT3B4 gained an increased DNA methylation in RASSF1A promoter but not p16 promoter. We conclude that promoter DNA methylation can be differentially regulated and DeltaDNMT3Bs are involved in regulation of such promoter-specific de novo DNA methylation.

Ursolic acid inhibits STAT3 activation pathway leading to suppression of proliferation and chemosensitization of human multiple myeloma cells

The activation of signal transducers and activators of transcription 3 (STAT3) has been linked with the proliferation of a variety of human cancer cells, including multiple myeloma. Agents that can suppress STAT3 activation have potential for prevention and treatment of cancer. In the present report, we tested an agent, ursolic acid, found in basil, apples, prunes, and cranberries, for its ability to suppress STAT3 activation. We found that ursolic acid, a pentacyclic triterpenoid, inhibited both constitutive and interleukin-6-inducible STAT3 activation in a dose- and time-dependent manner in multiple myeloma cells. The suppression was mediated through the inhibition of activation of upstream kinases c-Src, Janus-activated kinase 1, Janus-activated kinase 2, and extracellular signal-regulated kinase 1/2. Vanadate treatment reversed the ursolic acid-induced down-regulation of STAT3, suggesting the involvement of a tyrosine phosphatase. Indeed, we found that ursolic acid induced the expression of tyrosine phosphatase SHP-1 protein and mRNA. Moreover, knockdown of SHP-1 by small interfering RNA suppressed the induction of SHP-1 and reversed the inhibition of STAT3 activation, thereby indicating the critical role of SHP-1 in the action of this triterpene. Ursolic acid down-regulated the expression of STAT3-regulated gene products such as cyclin D1, Bcl-2, Bcl-xL, survivin, Mcl-1, and vascular endothelial growth factor. Finally, ursolic acid inhibited proliferation and induced apoptosis and the accumulation of cells in G1-G0 phase of cell cycle. This triterpenoid also significantly potentiated the apoptotic effects of thalidomide and bortezomib in multiple myeloma cells. Overall, these results suggest that ursolic acid is a novel blocker of STAT3 activation that may have a potential in prevention and treatment of multiple myeloma and other cancers.