Treatment of recalcitrant cases of tinea corporis/cruris caused by T. mentagrophytes - interdigitale complex with mutations in ERG11 ERG 3, ERG4, MDR1 MFS genes & SQLE and their potential implications

BACKGROUND

Recalcitrant dermatophyte infections are being reported from various parts of the world due to varied causes including strain variation, steroid misuse, SQLE mutations, and variable quality of itraconazole pellet formulations. The oral drug preferred in endemic areas is itraconazole, to which MIC levels remain low, and clinical failures to itraconazole reported defy a sound scientific explanation.

OBJECTIVES

The objective of the study was to conduct a proteomic and genomic analysis on isolates from therapeutically recalcitrant case with isolation of gene mutations and enzymatic abnormalities to explain azole failures.

METHODS

Trichophyton mentagrophyte interdigitale complex strains were isolated from seven clinically non-responding tinea corporis/cruris patients, who had failed a sequential course of 6 weeks of terbinafine 250 mg QD and itraconazole 100 mg BID. After AFST 1 strain, KA01 with high MIC to most drugs was characterized using whole genome sequencing, comparative proteomic profiling, and total sterol quantification.

RESULTS

Sterol quantification showed that the standard strain of Trichophyton mentagrophytes (MTCC-7687) had half the ergosterol content than the resistant KA01 strain. Genomic analysis revealed mutations in SQLE, ERG4, ERG11, MDR1, MFS genes, and a novel ERG3 mutation. Proteomic analysis established the aberrant expression of acetyl Co-A transferase in the resistant strain and upregulation of thioredoxin reductase and peroxiredoxin.

CONCLUSION

Our findings demonstrate possible reasons for multidrug resistance in the prevalent strain with mutations in genes that predict terbinafine (SQLE) and azole actions (ERG4, ERG11, ERG3) apart from efflux pumps (MDR1, MFS) that can explain multidrug clinical failures.

Epidemiology and impact of frailty in patients with atrial fibrillation in Europe

BACKGROUND

Frailty is a medical syndrome characterised by reduced physiological reserve and increased vulnerability to stressors. Data regarding the relationship between frailty and atrial fibrillation (AF) are still inconsistent.

OBJECTIVES

We aim to perform a comprehensive evaluation of frailty in a large European cohort of AF patients.

METHODS

A 40-item frailty index (FI) was built according to the accumulation of deficits model in the AF patients enrolled in the ESC-EHRA EORP-AF General Long-Term Registry. Association of baseline characteristics, clinical management, quality of life, healthcare resources use and risk of outcomes with frailty was examined.

RESULTS

Among 10,177 patients [mean age (standard deviation) 69.0 (11.4) years, 4,103 (40.3%) females], 6,066 (59.6%) were pre-frail and 2,172 (21.3%) were frail, whereas only 1,939 (19.1%) were considered robust. Baseline thromboembolic and bleeding risks were independently associated with increasing FI. Frail patients with AF were less likely to be treated with oral anticoagulants (OACs) (odds ratio 0.70, 95% confidence interval 0.55-0.89), especially with non-vitamin K antagonist OACs and managed with a rhythm control strategy, compared with robust patients. Increasing frailty was associated with a higher risk for all outcomes examined, with a non-linear exponential relationship. The use of OAC was associated with a lower risk of outcomes, except in patients with very/extremely high frailty.

CONCLUSIONS

In this large cohort of AF patients, there was a high burden of frailty, influencing clinical management and risk of adverse outcomes. The clinical benefit of OAC is maintained in patients with high frailty, but not in very high/extremely frail ones.

374 Are Operative Notes Adhering to the Standards of Good Practice?

Aim

Thorough documentation is imperative for postoperative care, quality improvement, research, and medico-legal enquiries. For these reasons this closed loop audit aimed to assess whether the local Trauma and Orthopaedic departments’ operative notes were adhering to the guidance outlined by The Royal College of Surgeons, in order to to follow good practice.

Method

This was a random data collection, single centre study performed which analysed 50 operative notes from a variety of Trauma and Orthopaedic surgical procedures (not including neck of femur fractures and elective surgeries). The next cycle of the audit was completed after departmental re-education and a new operative note pro forma was created and put in place.

Results

The first audit cycle demonstrated that 8 categories in the operative note were below 96 % compliance with the guidance, of these being: time, name of operating surgeon/anaesthetist, operative procedure, incision, operative diagnosis, DVT prophylaxis, signature. Furthermore, an interesting finding showed no complications were identified in any operative note, similarly no extra procedures were documented. The second audit cycle showed that there was 100% compliance gained across all categories. Additionally, the new pro forma had an option to specify if there was/or not any complications, which had 100 % compliance in the second cycle and identified one complication.

Conclusions

Overall this audit was able to standardise the operative notes and improve quality and structure in order to follow good practice, by implementing a new pro forma and re-educating the department. This ensures that the best standard of care is being delivered.

A Real-World Comparative Effectiveness Analysis of Thromboprophylactic Use of Enoxaparin Versus Unfractionated Heparin in Abdominal Surgery Patients in a Large U.S. Hospital Database

Introduction: Little is known about outcomes associated with enoxaparin versus unfractionated heparin (UFH) for venous thromboembolism (VTE) prophylaxis in abdominal surgery patients in U.S. clinical practice. The purpose of this study was to compare VTE, all-cause mortality, PE-related in-hospital mortality, and hospital costs during abdominal surgery hospitalization and the 90 days post-discharge between patients who received enoxaparin versus UFH prophylaxis. Materials and Methods: Using the Premier Healthcare Database, abdominal surgery patients who received at least 1 day of VTE prophylaxis with enoxaparin or UFH were identified between January 1, 2010 and September 30, 2016. Clinical outcomes were assessed using multivariable logistic regression models and cost outcomes were assessed using generalized linear models. Results: Of 363,669 patients identified, 59% received enoxaparin and 41% UFH. In adjusted analyses, there were statistically significant lower odds of VTE (OR 0.80; 95% CI 0.65-0.97), all-cause mortality (OR 0.67; 95% CI 0.60-0.75), and major bleeding (OR 0.88; 95% CI 0.82-0.94) during the hospitalization for enoxaparin versus UFH, but no differences during the 90-days post-discharge or for PE-related mortality. There was a statistically significant lower total hospital cost with enoxaparin versus UFH during index hospitalization ($8,913 vs $9,017, P < .0001), but not post-discharge ($3,342 vs $3,368, P = .42). Unadjusted rates of heparin-induced thrombocytopenia (index:0.1% vs 0.3%; post-discharge: 0.02% vs 0.06%) were reported for enoxaparin and UFH, respectively. Conclusion: In contemporary U.S. hospital practice, statistically significant lower odds of VTE, all-cause mortality and major bleeding with enoxaparin versus UFH prophylaxis were found during abdominal surgery hospitalizations.

128 Rapidly Proliferative Pilomatrixoma On the Eyebrow of A 7-Year-Old Boy – A Case Report

Pilomatrixoma or calcifying epithelioma of Malherbe is a benign tumour originating from pluripotent precursors of hair matrix cells. We present a paediatric patient with a rapidly enlarging eyebrow mass with a differential diagnosis of sebaceous cyst, pyogenic granuloma, or malignancy.

A 7-year-old boy presented in primary care with a 0.5cm non-inflammatory nodule on his medial brow present for 2-3 months. History of previous trauma was not elicited and there were no features of bleeding or ulceration. It was then lanced, following diagnosis of an infected sebaceous cyst. Within weeks, the nodule underwent rapid proliferation, enlarging to 2cm in diameter. He was urgently referred to secondary care pending further investigation for possible trauma-induced pyogenic granuloma or malignancy.

Upon presentation in secondary care, we observed a protruding erythematous and ulcerated mass, indurated in texture and adherent to overlying skin. The patient was submitted to excisional biopsy with a vertical elliptical approach to minimise distortion of the brow. Small, calcified deposits were observed in the tumour substance. Histologically, basaloid basophilic cells were predominant and mixed with ghost cells and foci of giant multinucleate cells, verifying diagnosis of a pilomatrixoma.

Pilomatrixoma exhibits tendency towards mimicry of lesions such as epidermoid, sebaceous, dermoid cyst, pyogenic granuloma or even keratoacanthoma with a pre-operative detection rate as low as 11%. With a bimodal age distribution, arising in the first and sixth decades of life, this case highlights a need for a high degree of suspicion in young patients with careful clinical examination in order to aid diagnosis and prompt appropriate treatment.

Left ventricular involvement in arrhythmogenic right ventricular cardiomyopathy

Background

Arrhythmogenic right ventricular cardiomyopathy (ARVC) is not an isolated RV disease. Left ventricular (LV) or biventricular involvement is being increasingly diagnosed in such patients. There is available research to show that the LV peak strain calculated from feature tracking (FT) cardiac MRI is impaired even before the impairment of function. If present, such involvement is an adverse prognostic marker.

Purpose

The aim of this study is to calculate LV involvement in patients with ARVC using FT cardiac MRI.

Methods

27 patients of ARVC who underwent cardiac MRI with late gadolinium enhancement (LGE) in our department were identified. 10 healthy volunteers (controls) were also assessed using non-contrast cardiac MRI. LV strain analysis was performed using Cvi42 Circle cardiovascular imaging software; and global LV peak radial, circumferential and longitudinal strain values were calculated. Patients were divided into two sub groups: those with preserved LV ejection fraction (LVEF) and those with reduced LVEF. Peak LV strain values were compared between the two groups of ARVC patients; and between ARVC patients with preserved LVEF and healthy volunteers.

Results

The LV peak global longitudinal strain (GLS), global circumferential strain (GCS) and global radial strain (GRS) were −17.7±2.47, −18.16±2.65, 31.04±6.07 respectively in healthy volunteers. LV global longitudinal (GLS), circumferential (GCS), and radial strain (GRS) were significantly impaired in ARVC/D patients (GLS: −11.97±4.34%, GCS: −14.35±4.32%, GRS: 22.1±7.39%). ARVC patients were divided into 2 subgroups: the preserved LV ejection fraction (LVEF) group (LVEF ≥55%, n=9) and the reduced LVEF group (LVEF &lt;55%, n=18). In ARVC patients with reduced LVEF, the peak GLS was −9.99±3.94, GCS was −12.88±4.08 and GRS was 19.57±7.56. With preserved LVEF these values were −15.1±3.02, −17.3±3.3 and 27.1±3.67 respectively. In ARVC patients with preserved LVEF, the peak LV strain were impaired when compared with healthy volunteers with significant difference in peak GLS in between the two groups (p=0.05).

Conclusion

In patients with ARVC, cardiac MRI feature tracking can detect early LV dysfunction and thus adverse prognostic marker. Even in patients with normal LVEF, GLS was found to be significantly impaired as compared to healthy controls.

Calculation of longitudinal strain

Funding Acknowledgement

Type of funding source: None

Mechanistic Insight Into the Antifungal Effects of a Fatty Acid Derivative Against Drug-Resistant Fungal Infections

The prevalence of drug-resistant pathogenic fungi is a major global health challenge. There is an urgent need for novel drugs that can exert a potent antifungal activity and overcome resistance. Newly discovered anti-fungal properties of existing compounds can potentially offer a rapid solution to address this persistent threat. We rationalized that structures which disrupt the fungal cell membrane could address the above unmet need. As fatty acids underpin the formation and stability of cell membranes, we used computational simulations to evaluate the interactions between selected short chain fatty acids and a model cell membrane. Here, we report that caprylic acid could penetrate and perturb the membrane in silico. Based on the in silico findings, we identified a derivative of this fatty acid that disrupts fungal membranes as detected using steady-state fluorescence anisotropy. We show that this fatty acid derivative is potent against a variety of fungal pathogens like Candida and Trichophyton. We further demonstrated the ability of this fatty acid derivative to potentiate some azoles in vitro and enhance the efficacy of antifungal formulations in vivo. Our data suggests the emergence of a novel therapy for effective disease management and overcoming anti-fungal drug resistance.

The TRIXS end-station for femtosecond time-resolved resonant inelastic x-ray scattering experiments at the soft x-ray free-electron laser FLASH

We present the experimental end-station TRIXS dedicated to time-resolved soft x-ray resonant inelastic x-ray scattering (RIXS) experiments on solid samples at the free-electron laser FLASH. Using monochromatized ultrashort femtosecond XUV/soft x-ray photon pulses in combination with a synchronized optical laser in a pump-probe scheme, the TRIXS setup allows measuring sub-picosecond time-resolved high-resolution RIXS spectra in the energy range from 35 eV to 210 eV, thus spanning the M-edge (M₁ and M_2,3) absorption resonances of 3d transition metals and N_4,5-edges of rare earth elements. A Kirkpatrick-Baez refocusing mirror system at the first branch of the plane grating monochromator beamline (PG1) provides a focus of (6 × 6) μm² (FWHM) at the sample. The RIXS spectrometer reaches an energy resolution of 35-160 meV over the entire spectral range. The optical laser system based on a chirped pulse optical parametric amplifier provides approximately 100 fs (FWHM) long photon pulses at the fundamental wavelength of 800 nm and a fluence of 120 mJ/cm² at a sample for optical pump-XUV probe measurements. Furthermore, optical frequency conversion enables experiments at 400 nm or 267 nm with a fluence of 80 and 30 mJ/cm², respectively. Some of the first (pump-probe) RIXS spectra measured with this setup are shown. The measured time resolution for time-resolved RIXS measurements has been characterized as 287 fs (FWHM) for the used energy resolution.

Online survey about anesthesia-related practice and patient safety in Indian hospitals

BACKGROUND

Patient safety is a global concern, and anaesthesiologists are critically involved in patient safety-related measures and practices. Although anesthesia service has improved a lot over the last few decades, the information on the anesthesia practice and patient safety in India is lacking. The present survey was aimed to get the information on these aspects.

METHODS

A cross-sectional, questionnaire-based survey including both postgraduate trainees and anaesthesiologists, working across the different hospitals of India was conducted during February-May 2019. Google form was used as the survey; responses were directly downloaded as an Excel file and calculated in absolute numbers and percentages. Autonomous teaching institutes (ATI) were taken as standard, and Fisher's exact test was used for comparisons; P<0.05 was considered significant.

RESULTS

Six-hundred (86.1%) responses were included for analysis. Pulse oximetry and non-invasive blood pressure (NIBP) were available in nearly 99% set-ups, but end-tidal carbon-di-oxide (EtCO₂), temperature, oxygen, and anesthesia gas analyzer were lacking. ATI and corporate teaching hospitals were having almost all standard monitoring, but patient safety-related advanced equipment and medications were not present in many of the hospitals. The lack was highest in both public and private non-teaching hospitals (P<0.0001).

CONCLUSION

Patient safety and anesthesia-related services in India are unsatisfactory. Except for pulse oximetry and NIBP, the public and private sector non-teaching hospitals were lacking even the standard monitoring. Referral and top-level corporate and public sector institutes also have scope for improvement.

Efficacy and Safety of VB-1953 Topical Gel in Non-Responder Acne Patients with Clindamycin-Resistant Cutibacterium acnes

BACKGROUND AND OBJECTIVES

The emergence of resistant strains of Cutibacterium acnes can limit the efficacy of currently approved antibiotics for acne. VB-1953 is a next-generation antibiotic that exerts a bactericidal effect on resistant C. acnes. In this study, we investigated the safety, tolerability, and efficacy of VB-1953 topical gel in patients with moderate to severe acne having clindamycin-resistant C. acnes.

METHODS

An investigator-initiated, open label, single-arm clinical study was conducted in patients with moderate to severe facial acne vulgaris showing poor or no response to previous clindamycin treatment. Nineteen subjects were enrolled in the study based on laboratory screening for the presence of clindamycin-resistant C. acnes in acne swab samples collected from patients. VB-1953 2% gel was applied on the entire face twice daily over 12 weeks. The primary efficacy endpoints were absolute changes in inflammatory and noninflammatory lesion counts from baseline at week 12, while the secondary efficacy endpoint was the proportion of subjects achieving Investigator Global Assessment success (score of 0 or 1) or a grade 2 or higher improvement from baseline at week 12. The presence and severity of local skin reactions (erythema, edema, scaling/dryness, burning/stinging, pruritus) were evaluated for safety. Additionally, the detection and quantification of drug-resistant C. acnes strains were performed in the laboratory using acne swab samples collected from patients.

RESULTS

The occurrence of treatment-emergent adverse events or changes in vital signs, physical examinations, and urinalysis for any of the patients during the course of the entire study were clinically insignificant. Topical application of 2% VB-1953 topical gel resulted in a significant reduction of mean absolute inflammatory and noninflammatory lesion counts by 53.1% and 52.2%, respectively (p < 0.0001 for both), with an Investigator Global Assessment success of 26.3% at week 12 compared with baseline. Resistant bacteria were reduced by (94.3 ± 1%; p < 0.05) within 12 weeks of treatment with VB-1953.

CONCLUSION

These results indicate that VB-1953 topical gel can be a safe and effective therapy for moderate to severe acne with underlying resistant C. acnes in subjects who had not responded to previous antibiotic treatments.

P2797Clinical outcomes of an ultra-thin strut sirolimus-eluting stent with biodegradable polymer in all-comers patients undergoing coronary intervention

Background

Thin stent struts may be associated with reduced vessel injury and use of biodegradable polymers may further improve long term outcomes. However, data with earlier stents has been inconsistent; thus further studies with newer devices are needed.

Purpose

To evaluate the efficacy and safety of a new ultra-thin (65um) strut cobalt chromium sirolimus-eluting stent with a hybrid design (closed cell at ends and open cells in middle to reduce edge injury and optimise conformability) in all-comers patients undergoing percutaneous coronary intervention (PCI).

Methods

We enrolled 752 patients from 14 sites undergoing PCI into a prospective, non-randomised, multi-centre, open-label, observational registry. Inclusion of patients with complex anatomy (long stent lengths, bifurcations and chronic total occlusions) was encouraged. Clinical follow-up was scheduled at 1, 9, 12 and 24 months. The primary endpoint was incidence of major adverse cardiac events (MACE) - cardiac death, non-fatal myocardial infarction (MI), or target vessel revascularization (TVR) - at 9 months.

Results

Mean patient age was 64.7±12.2 years, 20.7% had diabetes, 58.8% had dyslipidaemia, 40.4% had multi-vessel disease, 22% had previous PCI, 4.7% had previous coronary-artery bypass graft, and 19.6% had a clinical history of previous MI. Mean lesion length was 25.7±17.3 mm. The primary endpoint of cumulative MACE up to 9 months (from 624 patients reaching 9 months follow-up) occurred in 12 patients (1.92%), including 6 (0.96%) cardiac death, 5 (0.80%) MI and 6 (0.96%) clinically indicated TVR. Definite stent thrombosis was reported in 3 patients (0.48%) and probable stent thrombosis in 2 patients (0.32%).

Conclusions

Use of an ultra-thin strut biodegradable polymer sirolimus-eluting stent in all-comers patients undergoing PCI was associated with good clinical efficacy and safety.

Acknowledgement/Funding

Meril Life

Cardiometabolic risk profile based on body mass index in American Indian children and adolescents

BACKGROUND

Childhood obesity is associated with increased cardiometabolic risk.

OBJECTIVE

To study the relationship between body mass index (BMI) and cardiometabolic risk factors in American Indian children and adolescents.

METHODS

Differences in metabolic variables by age and sex-specific BMI percentiles (2000 Centers for Disease Control and Prevention Growth Charts) were examined in a cross-sectional analysis of 2977 individuals across three age categories. Children with an exam in two consecutive age categories were included in a longitudinal analysis. Spearman's correlations were used to test the association of BMI percentile with anthropometric and biochemical variables.

RESULTS

Body mass index percentile correlated with systolic (r = 0.24 to 0.38) and diastolic (r = 0.13 to 0.22) blood pressure, fasting plasma glucose (r = 0.20 to 0.33), 2-h plasma glucose (r = 0.30 to 0.46), total cholesterol (r = 0.12 to 0.23), serum triglycerides (r = 0.40 to 0.51) and HDL cholesterol (r = -0.36 to -0.43) in each age group (5-9, 10-13 and 14-17 years). Among participants examined in multiple age categories, BMI percentile increased over time. Change in BMI percentile from one age category to the next was associated with an increase in fasting glucose, 2-h glucose and triglycerides and a decrease in HDL cholesterol.

CONCLUSION

Higher BMI was associated with blood pressure elevation, hyperglycaemia and dyslipidaemia in American Indian children and adolescents.

Clinical and microbiological profile of febrile neutropenia in solid tumors and hematological malignancies at a tertiary cancer care center in South India

BACKGROUND

Febrile neutropenia (FN) is a common but serious complication of chemotherapy in patients with solid tumors (ST) and hematological malignancies (HM). The epidemiology of FN keeps changing.

OBJECTIVE

The objective was to study the epidemiology of FN in adult patients with ST and HM at Kidwai Memorial Institute of Oncology, Bangalore - A tertiary cancer care center.

MATERIALS AND METHODS

Data of all episodes of FN that occurred during the period July 2011 to December 2011 were collected prospectively and analyzed.

RESULTS

A total of 75 episodes of FN was observed during study period involving 55 patients. Febrile neutropenic episodes were more frequent in HM than in ST (57% vs. 43%). The rate of bloodstream infection was 14.7%. Gram-negative organisms were the predominant isolates (56.25%). Overall mortality rate was 13.3%. Presence of medical co-morbidity and positive culture predicted high mortality. Mortality rate did not differ significantly between HM and ST (14% vs. 12.5%; P = 1.0). Gram-positive bacteremia was associated with greater mortality than Gram-negative bacteremia (P = 0.02).

CONCLUSION

Empiric antibiotic treatment for FN should be tailored to the locally prevalent pathogens and their susceptibility patterns.

Differential inflammasome activation signatures following intracellular infection of human macrophages with Mycobacterium bovis BCG or Trypanosoma cruzi

Pathogens frequently exploit or evade inflammasome activation in order to survive and proliferate. Alternatively, inadequate inflammasome activation by attenuated microorganisms or adjuvanted subunit vaccines may contribute to poor longevity of protection. To further understand these pathways, we determined the differential inflammasome transcriptome of human THP monocyte-derived macrophages in response to Mycobacterium bovis BCG, as compared to LPS or Trypanosoma cruzi. The results identify the highly specific innate recognition programs associated with inflammasome activation by human macrophages exposed to these microbial stimuli. BCG, T. cruzi, and LPS strongly induced expression of both unique and overlapping genes downstream of TLR signaling pathways including cytokines and chemokines that mediate inflammation and regulate cell death pathways. Compared to LPS, BCG failed to directly activate anti-apoptotic molecules and multiple NLR and inflammasome complex components including caspase-1, and actively repressed important signaling intermediates in AP-1 and NFκB transcription factor pathways. Both BCG and T. cruzi repressed expression of TXNIP, an anti-oxidant inhibitor that recruits caspase-1 to the NLRP3 inflammasome, while T. cruzi infection uniquely failed to activate TNF-α. These results identify unique pathogen specific strategies to activate inflammation and modulate cell death that may drive inflammatory outcomes and suggest avenues of investigation to optimize host immunity.

Antibiotic-resistant acne: getting under the skin

Propionibacterium acnes is a key pathogenic factor in the development of acne. Antibiotics are the first choice of treatment for mild-to-moderate, mixed, papular/pustular, and moderate nodular acne, and an alternative choice in severe, nodular/conglobate acne. The emergence of resistance to the currently available antibiotics poses a serious set-back to this algorithm, and the reduced arsenal can diminish efficacy of treatment. This emerging situation should catalyze innovations in dermatology; for example, newer drugs and technologies such as next-generation antibiotics with excellent potency and low propensity to develop resistance, rapid diagnostic platforms to select responders and nonresponders, and delivery technologies that target the bacteria. Such innovations can dramatically expand the arsenal for dermatologists in the management of acne.

No evidence of association of xenotropic murine leukemia virus-related virus with oral cancers: Experience from a tertiary care center in South India

BACKGROUND

Development of oral cancer, a widely prevalent cancer in India, is multifactorial with increased risk in those habituated to smoking, consuming alcohol and chewing paan and tobacco. This does not preclude other etiological factors in the causation of this cancer. Exploratory studies on several oncogenic viruses have found varied associations with oral cancers.

AIM

The aim of this study was to explore the association of xenotropic murine leukemia virus-related virus, (XMRV) a retrovirus recently implicated in oncogenesis in humans, with oral cancers.

SETTINGS AND DESIGN

The presence of XMRV proviral deoxyribonucleic acid (DNA) was evaluated by standard nucleic acid amplification from DNA extracted from representative bits of tumor tissues and adjacent normal tissues from surgically resected specimens sent post-operatively for routine histopathological testing.

MATERIALS AND METHODS

This prospective study comprised 109 patients with a provisional diagnosis of oral cancer who were operated at the Oral Oncology Department of Kidwai Memorial Institute of Oncology, over a period of 10 months.

RESULTS

XMRV was not found in any of the tumor tissues (squamous cell carcinomas - 98; verrucous carcinomas - 4) nor in any of the normal tissues. It is thus important that the absence of this oncogenic virus in all the cases makes the association of XMRV with oral cancers very unlikely.

CONCLUSIONS

There is a need to investigate potentially oncogenic viruses in other solid tumors and in larger sample sizes. Any such association could have implications in detecting, preventing and treating these cancers.

Rare Presentation of Chorioadenoma Destruens as Acute Haemoperitoneum Mimicking Ruptured Ectopic Pregnancy

Gestational trophoblastic neoplasms (GTN) are proliferative degenerative disorders of placental elements and include complete or partial mole (90%), invasivemole (5-8%), choriocarcinoma (1-2%) and placental site tumor (1-2%). Chorioadenoma destruens is a trophoblastic tumor, characterized by myometrial invasion through direct extension or via venous channels. We present a case of invasive mole eroding uterus and uterine vasculature, causing sudden rupture of uterus with massive haemoperitoneum mimicking ectopic pregnancy. A 20 year old G1P0 at 6 weeks gestation presented in Casualty of Kasturba Hospital complaining of severe acute onset lower abdominal pain for one hour. Clinical examination revealed shock. Sonography suggested ectopic pregnancy and immediate exploratory laparotomy was decided. On laparotomy, 2000cc of haemoperitoneum was noted. Grape like vesicles protruding through fundal perforation with profuse active bleeding was seen. Bleeding persisted despite evacuation. Step wise uterine devascularisation failed to achieve haemostasis. Total abdominal hysterectomy was performed as a life saving measure.

Influence of Carbon and Microbial Community Priming on the Attenuation of Uranium in a Contaminated Floodplain Aquifer

The capacity for subsurface sediments to sequester radionuclide contaminants, such as uranium (U), and retain them after bioremediation efforts are completed is critical to the long-term stewardship of re-mediated sites. In U bioremediation strategies, carbon amendment stimulates bioreduction of U(VI) to U(IV), immobilizing it within the sediments. Sediments enriched in natural organic matter are naturally capable of sequestering significant U, but may serve as sources to the aquifer, contributing to plume persistence. Two types of organic-rich sediments were compared to better understand U release mechanisms. Sediments that were artificially primed for U removal were retrieved from an area previously biostimulated while detrital-rich sediments were collected from a location never subject to amendment. Batch incubations demonstrated that primed sediments rapidly removed uranium from the groundwater, whereas naturally reduced sediments released a sizeable portion of U before U(VI)-reduction commenced. Column experiments confirmed that U release persisted for 65 pore volumes in naturally reduced sediments, demonstrating their sink-source behavior. Acetate addition to primed sediments shifted the microbial community from sulfate-reducing bacteria within Desulfobacteraceae to the iron-reducing Geobacteraceae and Firmicutes, associated with efficient U(VI) removal and retention, respectively. In contrast, Geobacteraceae communities in naturally reduced sediments were replaced by sequences with similarity to Pseudomonas spp. during U release, while U(VI) removal only occurred with enrichment of Firmicutes. These investigations stress the importance of characterizing zones with heterogeneous carbon pools at U-contaminated sites prior to the determination of a remedial strategy to identify areas, which may contribute to long-term sourcing of the contaminants.

Structures and binding studies of the complexes of phospholipase A2 with five inhibitors

Phospholipase A2 (PLA2) catalyzes the hydrolysis of phospholipids into arachidonic acid and lysophospholipids. Arachidonic acid is used as a substrate in the next step of the multistep pathway leading to the production of eicosanoids. The eicosanoids, in extremely low concentrations, are required in a number of physiological processes. However, the increase in their concentrations above the essential physiological requirements leads to various inflammatory conditions. In order to prevent the unwanted rise in the concentrations of eicosanoids, the actions of PLA2 and other enzymes of the pathway need to be blocked. We report here the structures of five complexes of group IIA PLA2 from Daboia russelli pulchella with tightly binding inhibitors, (i) p-coumaric acid, (ii) resveratrol, (iii) spermidine, (iv) corticosterone and (v) gramine derivative. The binding studies using fluorescence spectroscopy and surface plasmon resonance techniques for the interactions of PLA2 with the above five compounds showed high binding affinities with values of dissociation constants (KD) ranging from 3.7×10(-8) M to 2.1×10(-9) M. The structure determinations of the complexes of PLA2 with the above five compounds showed that all the compounds bound to PLA2 in the substrate binding cleft. The protein residues that contributed to the interactions with these compounds included Leu2, Leu3, Phe5, Gly6, Ile9, Ala18, Ile19, Trp22, Ser23, Cys29, Gly30, Cys45, His48, Asp49 and Phe106. The positions of side chains of several residues including Leu2, Leu3, Ile19, Trp31, Lys69, Ser70 and Arg72 got significantly shifted while the positions of active site residues, His48, Asp49, Tyr52 and Asp99 were unperturbed.

Crystal structure of peptidyl-tRNA hydrolase from a Gram-positive bacterium, Streptococcus pyogenes at 2.19 Å resolution shows the closed structure of the substrate-binding cleft

•

Structure of peptidyl-tRNA hydrolase (Pth) from Streptococcus pyogenes.

•

First structure of Pth from a Gram-positive bacterium.

•

Conformations of the lid and gate loops are different from those observed in other Pth enzymes.

•

The substrate-binding channel is closed at both sites of the lid and gate loops.

•

In Pth structures from other species, the channel is fully open at the lid loop.

Peptidyl-tRNA hydrolase (Pth) catalyses the release of tRNA and peptide components from peptidyl-tRNA molecules. Pth from a Gram-positive bacterium Streptococcus pyogenes (SpPth) was cloned, expressed, purified and crystallised. Three-dimensional structure of SpPth was determined by X-ray crystallography at 2.19 Å resolution. Structure determination showed that the asymmetric unit of the unit cell contained two crystallographically independent molecules, designated A and B. The superimposition of C^α traces of molecules A and B showed an r.m.s. shift of 0.4 Å, indicating that the structures of two crystallographically independent molecules were identical. The polypeptide chain of SpPth adopted an overall α/β conformation. The substrate-binding cleft in SpPth is formed with three loops: the gate loop, Ile91–Leu102; the base loop, Gly108–Gly115; and the lid loop, Gly136–Gly150. Unlike in the structures of Pth from Gram-negative bacteria, the entry to the cleft in the structure of SpPth appeared to be virtually closed. However, the conformations of the active site residues were found to be similar.

Crystal structure of the complex of GLPO with an anti-thyroid drug PTU

Lactoperoxidase is a member of mammalian heme peroxidase superfamily that consists of lactoperoxidase (LPO), myloperoxidase (MPO), thyroid peroxidase (TPO), eosinophil peroxidase (EPO). So far crystal structures of only two mammalian peroxidases LPO and MPO have been determined. The structures of LPO have been determined from the samples obtained from bovine, buffalo, goat and sheep. Their complexes have also been determined with inhibitors and substrate analogues. However, the structures of EPO and TPO have not been obtained so far. Due to significant sequence identity between LPO and TPO, the structures of these proteins are expected to be similar. Similarly their substrates will also have similarity as well as the substrate and enzyme interactions will be similar. Therefore, a complex of LPO was prepared with propylthiouracil (PTU), a compound used as a drug in thyroid ailments. The complex was crystallized using co-crystallization. The crystals of native LPO were also soaked in the solution containing PTU. The crystals belonged to monoclinic space group with cell dimensions a = 80.2 Å, b = 82.5, c = 95.0, β = 73.7° There were four molecules of LPO in the asymmetric unit. The structure determination of the complex revealed that PTU binds to the LPO at the distal heme site. It is held at this site through several hydrogen bonds and van der Waals contacts. The mode of binding and number of interactions suggest that a similar mode of binding may occur with TPO. Based on the information of interactions and the missing potential interactions, the modifications in the structure of PTU are suggested so that the improved design of the TPO inhibitor is obtained.

Stacking Interactions mediate Recognition in Ribosome Inactivating Protein

Ribosome Inactivating Proteins (RIPs) are capable of inhibiting protein synthesis by catalytically hydrolyzing at specific purine residues from the sarcin / ricin loop of large ribosomal RNA. There are two types of RIPs: type 1 - RIPs (RIP-1) are single polypeptide chain proteins while type 2 - RIPs contain two polypeptide chains which are covalently linked by a disulphide bond. Studies have indicated that stacking interactions play a dominant role in the ligand binding to RIPs. However, the structural basis of these interactions with RIPs as well as the nature of stack pairing and associated molecular mechanisms are not clearly understood. In order to examine the significance of these stacking interactions and the role of various aromatic residues involved, we have carried out the structural analysis of the complexes of RIP-1 from Momordica balsamina (MbRIP-1) and crystallized it with six different sugar molecules, ribose, fucose, glucose, fructose, maltose and lactose. The crystals belong to hexagonal space group H3 with approximate cell dimension of a = b = 130 Å, c = 40.5 Å. The r.m.s. deviation for the Calpha atoms in the complexed structures was found to be in the range of 0.5 Å to 0.9 Å. The aromatic rings of sugars are seen to be involved in stacking with aromatic rings of Tyr 70 and Tyr 111. The side chain torsion angles chi1 and chi2 of Tyr 70 in the complexes with ribose, fucose, glucose, fructose, maltose and lactose were found to be 64° / 161°, 166° / 86°, 6° / 172°, 70° / 167°, 64° / 161° and -75° / 178° respectively. The sugars are held firmly in the binding site of RIP-1 with the help of stacking interactions and hydrogen bonds. The results presented here have revealed the significance of aromatic stack pairing and delineated the stabilizing role of tyrosine residue in these interactions.

Oxidative stress and amyloid beta toxicity in Alzheimer's disease: intervention in a complex relationship by antioxidants

The elucidation of the intriguing relationship between oxidative stress and Alzheimer's disease is crucial to understand the pathogenesis of the disease as also to design a suitable drug trial with antioxidants against this condition. We begin by reviewing the basic facts about Alzheimer's disease and the chemistry and biology of oxygen free radicals with particular reference to the cellular adaptive response through redox-signalling pathways. The post-mortem evidence of oxidative damage in the brain of Alzheimer's disease patients is overwhelming which is also supported by the similar changes in transgenic mice models of this disease. However, the causal relationship of oxidative stress with amyloid beta pathology or the genesis of Alzheimer's disease is not clear. Considering the available evidence the review suggests that the oxidative stress could be an early event in the disease process and may trigger various adaptive responses such as the alterations of amyloid beta metabolism and the activation of stress responsive kinases which can subsequently lead to neuronal degeneration and AD pathology. Further, we have presented a large body of evidence from various studies to highlight the beneficial effects of antioxidants against amyloid beta toxicity or AD pathology in animal or cell based models of AD. The failure of clinical trials with antioxidants against AD has been mentioned and the possible causes of such failures have been analysed.

Preparation and antimicrobial action of three tryptic digested functional molecules of bovine lactoferrin

Lactoferrin is an 80 kDa bilobal, iron binding glycoprotein which is primarily antimicrobial in nature. The hydrolysis of lactoferrin by various proteases in the gut produces several functional fragments of lactoferrin which have varying molecular sizes and properties. Here, bovine lactoferrin has been hydrolyzed by trypsin, the major enzyme present in the gut, to produce three functional molecules of sizes approximately 21 kDa, 38 kDa and 45 kDa. The molecules have been purified using ion exchange and gel filtration chromatography and identified using N-terminal sequencing, which reveals that while the 21 kDa molecule corresponds to the N2 domain (21LF), the 38 kDa represents the whole C-lobe (38LF) and the 45 kDa is a portion of N1 domain of N-lobe attached to the C-lobe (45LF). The iron binding and release properties of 21LF, 38LF and 45LF have been studied and compared. The sequence and structure analysis of the portions of the excision sites of LF from various species have been done. The antibacterial properties of these three molecules against bacterial strains, Streptococcus pyogenes, Escherichia coli, Yersinia enterocolitica and Listeria monocytogenes were investigated. The antifungal action of the molecules was also evaluated against Candida albicans. This is the first report on the antimicrobial actions of the trypsin cleaved functional molecules of lactoferrin from any species.

Structure of chitinase D from Serratia proteamaculans reveals the structural basis of its dual action of hydrolysis and transglycosylation

Chitinases are known to hydrolyze chitin polymers into smaller chitooligosaccharides. Chitinase from bacterium Serratia proteamaculans (SpChiD) is found to exhibit both hydrolysis and transglycosylation activities. SpChiD belongs to family 18 of glycosyl hydrolases (GH-18). The recombinant SpChiD was crystallized and its three-dimensional structure was determined at 1.49 Å resolution. The structure was refined to an R-factor of 16.2%. SpChiD consists of 406 amino acid residues. The polypeptide chain of SpChiD adopts a (β/α)8 triosephosphate isomerase (TIM) barrel structure. SpChiD contains three acidic residues, Asp149, Asp151 and Glu153 as part of its catalytic scheme. While both Asp149 and Glu153 adopt single conformations, Asp151 is observed in two conformations. The substrate binding cleft is partially obstructed by a protruding loop, Asn30 - Asp42 causing a considerable reduction in the number of available subsites in the substrate binding site. The positioning of loop, Asn30 - Asp42 appears to be responsible for the transglycosylation activity. The structure determination indicated the presence of sulfone Met89 (SMet89). The sulfone methionine residue is located on the surface of the protein at a site where extra domain is attached in other chitinases. This is the first structure of a single domain chitinase with hydrolytic and transglycosylation activities.

Lactoperoxidase: structural insights into the function,ligand binding and inhibition

Lactoperoxidase (LPO) is a member of a large group of mammalian heme peroxidases that include myeloperoxidase (MPO), eosinophil peroxidase (EPO) and thyroid peroxidase (TPO). The LPO is found in exocrine secretions including milk. It is responsible for the inactivation of a wide range of micro-organisms and hence, is an important component of defense mechanism in the body. With the help of hydrogen peroxide, it catalyzes the oxidation of halides, pseudohalides and organic aromatic molecules. Historically, LPO was isolated in 1943, nearly seventy years ago but its three-dimensional crystal structure has been elucidated only recently. This review provides various details of this protein from its discovery to understanding its structure, function and applications. In order to highlight species dependent variations in the structure and function of LPO, a detailed comparison of sequence, structure and function of LPO from various species have been made. The structural basis of ligand binding and distinctions in the modes of binding of substrates and inhibitors have been analyzed extensively.

Evidence of a novel allergenic protein Narcin in the bulbs of Narcissus tazetta

Several plant-derived allergens have been identified which result in the formation of immunoglobulin E antibodies. Primarily, these allergens belong to the protein families including seed storage proteins, structural proteins and pathogenesis-related proteins. Several allergens are also reported from flower bulbs which cause contact dermatitis. Such symptoms are highly common with the bulb growers handling different species of Narcissus. Narcissus toxicity is also reported if the bulbs are consumed accidentally. The present study aimed to characterize the protein from the bulbs of Narcissus tazetta responsible for its allergenic response. A 13 kDa novel allergenic protein, Narcin was isolated from the bulbs of Narcissus tazetta. The protein was extracted using ammonium sulfate fractionation. The protein was further purified by anion exchange chromatography followed by gel filtration chromatography. The N-terminal sequence of the first 15 amino-acid residues was determined using Edman degradation. The allergenicity of the protein was measured by cytokine production using flow cytometry in peripheral blood mononuclear cells. Further estimation of total IgE was performed by ELISA method. This novel protein was found to induce pro-inflammatory cytokines and thus induce allergy by elevating total IgE level. The novel protein, Narcin isolated from Narcissus tazetta was found to exhibit allergenic properties.

The mode of inhibitor binding to peptidyl-tRNA hydrolase: binding studies and structure determination of unbound and bound peptidyl-tRNA hydrolase from Acinetobacter baumannii

The incidences of infections caused by an aerobic Gram-negative bacterium, Acinetobacter baumannii are very common in hospital environments. It usually causes soft tissue infections including urinary tract infections and pneumonia. It is difficult to treat due to acquired resistance to available antibiotics is well known. In order to design specific inhibitors against one of the important enzymes, peptidyl-tRNA hydrolase from Acinetobacter baumannii, we have determined its three-dimensional structure. Peptidyl-tRNA hydrolase (AbPth) is involved in recycling of peptidyl-tRNAs which are produced in the cell as a result of premature termination of translation process. We have also determined the structures of two complexes of AbPth with cytidine and uridine. AbPth was cloned, expressed and crystallized in unbound and in two bound states with cytidine and uridine. The binding studies carried out using fluorescence spectroscopic and surface plasmon resonance techniques revealed that both cytidine and uridine bound to AbPth at nanomolar concentrations. The structure determinations of the complexes revealed that both ligands were located in the active site cleft of AbPth. The introduction of ligands to AbPth caused a significant widening of the entrance gate to the active site region and in the process of binding, it expelled several water molecules from the active site. As a result of interactions with protein atoms, the ligands caused conformational changes in several residues to attain the induced tight fittings. Such a binding capability of this protein makes it a versatile molecule for hydrolysis of peptidyl-tRNAs having variable peptide sequences. These are the first studies that revealed the mode of inhibitor binding in Peptidyl-tRNA hydrolases which will facilitate the structure based ligand design.

Effect of sub-maximal exercise stress on cold pressor pain: a gender based study

BACKGROUND

Analgesic effect of exercise is a well established fact; however available reports are contradictory on gender differences in pain perception following exercise stress test.

OBJECTIVE

The current study is prospectively designed to evaluate and compare the effect of acute bout of sub-maximal exercise stress on cold pressor pain in normal adult males and females.

METHOD

The experimental study design involved healthy adults (n= 41); females (n = 18) and males (n=23) aged between 18 to 25 years and included them into four sets of experiments: SET I (Control), "resting blood pressure, radial pulse and respiratory rate were recorded after 15 minutes of complete supine relaxation. SET II (Cold Pressor Pain Test): Pain Threshold, Pain Tolerance, and Pain Duration in seconds were taken. SET III (Exercise Stress Test): Sub-maximal exercise of 70 to 75% of maximum predicted heart rate was given for 6 minutes. SET IV (Cold Pressor Pain Test immediately after Exercise Stress Test): At 0 minute of recovery again the pain parameters; Pain Threshold, Pain Tolerance, and Pain Duration in seconds were taken. SET I, SET II were performed in order on the first day and SET III and SET IV on the second day to ensure only a single Cold Pressor Pain Test is performed in each day.

RESULT

The data (Mean ± SD) analysis showed significant increased in pain threshold (males: 14.36 ± 10.6 Vs 21.47 ± 13 seconds, p< 0.001, females: 14.1 ± 11.5 Vs 23.81 ± 20.22 seconds, p<0.001) and pain tolerance time (males: 41.3 ± 19.31 Vs 54.1 ± 21.7 seconds, p<0.001) in both sexes after 6 min of acute bout of sub-maximal exercise stress test with comparable age, BMI and baseline resting values of pain parameters and pulse rate and blood pressure. The percentage increment pain tolerance time following the exercise stress in female is higher than male (78.6 Vs 68.9%).

CONCLUSION

The result suggests that pain sensation decreases immediately after a brief period of exercise challenge irrespective of gender, and the analgesic effect of the acute bout of exercise in terms of pain tolerant time is more enhanced in females than males.

Cloning, expression, crystallization and preliminary structural studies of dihydrodipicolinate reductase from Acinetobacter baumannii

Acinetobacter baumannii is a virulent pathogenic bacterium that is resistant to most currently available antibiotics. Therefore, the design of drugs for the treatment of infections caused by A. baumannii is urgently required. Dihydrodipicolinate reductase (DHDPR) is an important enzyme which is involved in the biosynthetic pathway that leads to the production of L-lysine in bacteria. In order to design potent inhibitors against this enzyme, its detailed three-dimensional structure is required. DHDPR from A. baumannii (AbDHDPR) has been cloned, expressed, purified and crystallized. Here, the preliminary X-ray crystallographic data of AbDHDPR are reported. The crystals were grown using the hanging-drop vapour-diffusion method with PEG 3350 as the precipitating agent The crystals belonged to the orthorhombic space group P222, with unit-cell parameters a = 80.0, b = 100.8, c = 147.6 Å, and contained four molecules in the asymmetric unit. The complete structure determination of AbDHDPR is in progress.

Bacteraemia caused by Sciscionella marina in a lymphoma patient: phenotypically mimicking Nocardia

A 55-year-old female patient with malignant lymphoma after induction chemotherapy developed fever. Blood culture yielded an organism biochemically identified as representing Nocardia spp., but molecular identification (16S rRNA gene sequencing) later identified it as representing Sciscionella marina. This is the first report, to the best of our knowledge, of Sciscionella being isolated from a human sample.