Does caudal analgesia increase the rates of urethrocutaneous fistula formation after hypospadias repair? Systematic review and meta-analysis

INTRODUCTION

Caudal block analgesia is administered to lower the requirements of systemic and inhaled anesthetic drugs during hypospadias surgery. However, recent reports, all clustered in a short time-span have generated controversial and mutually opposing results while evaluating caudal block as an independent risk factor for urethroplasty-related complications after hypospadias repair. There is no consensus statement on the role of caudal block analgesia in formation of urethrocutaneous fistula (UCF) after hypospadias surgery. We performed a systematic review and meta-analysis of the studies evaluating the relative rates of UCF formation after hypospadias surgery in patients who were administered caudal block analgesia versus in those who were not.

METHODS

Electronic searches were performed using PubMed, PubMed Central, Google Scholar, Ovid, and the Cochrane library. Statistical analysis was performed using a fixed-effect model, odds ratios, risk ratios (RR), and heterogeneity (I2) were calculated. Funnel plot was used to assess for publication bias.

RESULTS

Seven studies with 1706 patients were included. Caudal block analgesia is associated with a significantly higher risk of UCF formation (RR: 1.81; 95% confidence interval [CI]: 1.30-2.53), (P = 0.0004) and other urethroplasty-related complications (RR 2.01; 95% CI: 1.48-2.74), (P < 0.00001) after hypospadias surgery. Funnel plots indicate some publication bias.

CONCLUSIONS

In patients undergoing hypospadias repair, administration of caudal analgesia is associated with a higher risk of UCF formation and other urethroplasty-related complications.

An efficient method for DNA extraction from cyanobacteria isolated from hypersaline and marine environments

Cyanobacteria are ancient organisms surviving on the earth due to their simple nutritional requirements and ability to produce distinct secondary metabolites that can combat detrimental environmental impacts. In order to understand these abilities of cyanobacteria at the molecular level, it is necessary to extract high-quality genomic DNA. However, the presence of secondary metabolites and exopolysaccharides hinders the DNA extraction from these organisms, especially from hypersaline environments. Here we have developed and compared a new method with two known methods of DNA extraction from environmental isolates. The results clearly indicate that the new optimized method yielded large amount of DNA with high purity. Additionally, the extracted DNA showed reduced degradation and excellent overall quality, which can be used directly for downstream purposes such as PCR and sequencing.

Evaluating unconscious bias: Speaker introductions at an international oncology conference

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Background: Gender bias can be reinforced through the use of gender-subordinating language and differences in the forms of address. We examined how professional titles were used during speakers’ introductions at the American Society of Clinical Oncology (ASCO) Annual Meeting. Methods: A retrospective observational study of video-archived speaker introductions at the 2017 and 2018 ASCO annual meetings was conducted. Data were extracted by mixed-gender coders. Professional address was defined as professional title followed by full name or last name. Multivariable logistic regressions were used to identify factors associated with the form of address. Results: 2511 videos were reviewed and 812 met inclusion criteria. Regarding speakers’ characteristics, 530 (65%) were non-Hispanic white (NHW), 743 (92%) held a MD or MD-PhD degree, and 484 (60%) were an associate or full professor. Female speakers were less likely to receive a professional address compared to male speakers (61% vs. 81%, p < 0.001). Female speakers were more likely to be introduced by first name only (17% vs. 3%, p < 0.001). Males were less likely to use a professional address when introducing female speakers compared to male speakers (53% vs. 80%, p < 0.01). No gender differences in professional address were observed for female introducers (p = 0.13). Male introducers were more likely to address female speakers by first name only compared to female introducers (24% vs. 7%, p < 0.01). In a multivariable regression including gender, race, degree, and academic rank, male speakers were more likely to receive a professional address compared to female speakers (OR: 2.67, 95%CI: 1.81-3.94, p < 0.01). Black speakers of both genders were less likely to receive a professional address compared to NHW (OR: 0.10, 95%CI: 0.01-0.53, p < 0.01). Female gender was a predictor for a non-professional form of address (first name only) (OR: 9.50, 95%CI: 4.38-20.62, p < 0.01). Conclusions: When introduced by men, female speakers were less likely to receive a professional address and more likely to be introduced by first name only compared to male speakers. Selective use of forms of address may strengthen gender bias; more research is needed to explore the causes of this disparity and its influence.

It starts at the top: An analysis of female representation in academic medical oncology (MO), radiation oncology (RO), and surgical oncology (SO) program leadership positions

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Background: Female underrepresentation in academic medicine leadership is well-documented; however, oncology specific data are scarce. This study evaluates female leadership representation in academic medical oncology (MO), radiation oncology (RO) and surgical oncology (SO) programs. Furthermore, we examine the impact of female leadership on overall female faculty representation. Methods: A total of 264 (96%) Accreditation Council for Graduate Medical Education actively accredited MO [144 of 153], RO [93 of 94] and SO [27 of 27] training programs were included. The gender of overall faculty and those in leadership positions (program director and departmental chair/division chief) of each program was determined using hospital websites from 10/01/18 to 01/27/19. The chi-squared goodness-of-fit test was used to examine whether the observed proportion of females in leadership positions deviates significantly from the expected proportion based on the actual proportion of overall female faculty in MO, RO and SO. Two-sample t-tests were used to compare rates of female faculty representation across each program based on the presence/absence of female in a leadership position for MO, RO and SO. Results: Female faculty representation in MO, RO and SO was 37.1% (1,554/4,191), 30.7% (389/1,269) and 38.8% (212/546), respectively. Female representation in leadership positions was 31.5% (82/260), 17.4% (31/178) and 11.1% (5/45), respectively. The observed proportion of females in leadership positions was significantly lower than the expected proportion of females in leadership positions for RO (17.4% vs. 30.7%, p = .0001) and SO (11.1% vs. 38.8%, p = .0001), and demonstrated a trend towards significance for MO (31.5% vs. 37.1%, p = .063). 47.9%, 33% and 18.5% of MO, RO and SO programs had ≥1 female in a leadership position, respectively. Programs that had a female in a leadership position had a higher mean percentage of overall female faculty than those that did not: 41.0% vs 35.0% (p = .0006), 36.0% vs 26.0% (p = .0002) and 39.0% vs 32.0% (p = .348) for MO, RO and SO, respectively. Conclusions: Gender disparity exists in academic MO, RO and SO faculty and is magnified at the leadership level. Programs with a female physician in a leadership position are associated with a higher percentage of female faculty.

Support structures for female physicians: Motivations and barriers to gender-specific conferences and symposia

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Background: While nearly half of all medical school graduates are female, women remain underrepresented in the physician workforce. Conferences or symposia designed to address issues relevant to female physicians, such as gender-bias, sexual harassment, and work-life balance are one strategy to improve retention and advancement, yet, limited data exists surrounding their utility. To address this gap, we surveyed a multi-disciplinary group of female physicians to identify motivations or barriers to attendance. Methods: An online survey instrument was distributed nationally via social media and shared by respondents. The survey assessed participants ’ demographics, attendance at gender-specific conferences or symposia, motivations or barriers to attendance, and perceived benefits of attendance. Results: Of 792 respondents, 34% had attended a conference or symposia for women in medicine, while 66% had not. Attendees were significantly more likely to hold a leadership position (68% vs. 43%, p < 0.0001), an academic faculty position (74% vs. 56%, p < 0.0001), and have received a professional accolade within the past year (42% vs. 28%, p < 0.0001). Non-attendees were significantly more likely to be the primary caregiver for children or seniors (64% vs. 56%, p = 0.042). Respondents indicated that an interest in discussion topics, a sense of community, and growth of professional network were key motivators in attendance. The majority of respondents indicated that attendance improved their self-advocacy, self-image, and leadership skills. Of those who did not attend, 51% were unaware of such conferences or symposia. Those who were aware, but unable to attend, cited lack of time as the major barrier to participation. Conclusions: The results of this study provide preliminary data surrounding gender-specific conferences or symposia for women in medicine and highlight opportunities for increased engagement. While not causative, attendees share attributes of professional success and report personal and professional benefits. Lack of awareness and access to child/family care are likely major barriers to participation, which can be addressed through strategic initiatives.

Corticosteroid-associated lupus pancreatitis: a case series and systematic review of the literature

BACKGROUND

Acute pancreatitis is an uncommon complication that occurs in 0.85% to 4% of patients with systemic lupus erythematosus (SLE). In some patients, it occurs within days to weeks of starting medium-to-high dose corticosteroids. The authors have used the term 'corticosteroid-associated lupus pancreatitis' for these patients, and they report a case series and perform a systematic review of previously published reports.

METHODS

For the purpose of this study, corticosteroid-associated lupus pancreatitis was defined as occurrence of acute pancreatitis in patients with SLE (fulfilling the 1997 ACR), within 3 weeks of starting therapy with medium-to-high dose corticosteroids - either newly initiated or escalated from a lower dose. All patients with SLE admitted in the last 2.5 years in a North Indian university hospital were reviewed, and those with pancreatitis who fulfilled the above criteria were included in the case series. For the systematic review, a PUBMED search using the keywords 'lupus' and 'pancreatitis' was performed, and reports in English were reviewed for an association with corticosteroids.

RESULTS

Among 420 admissions of SLE patients, six patients (1.4%) fulfilled criteria for corticosteroid-associated lupus pancreatitis. All were female, with mean age and disease duration of 19.7 ± 3.3 and 3.8 ± 2.5 years respectively. All had active disease and developed acute pancreatitis within 48-72 hours of newly initiating medium-to-high dose corticosteroids (in three patients) or escalating them to medium-high dose (in three patients). After the development of pancreatitis, corticosteroids were continued in all except one patient. In addition, two patients received pulse methylprednisolone, two received pulse cyclophosphamide and one was started on azathioprine. Three patients died during hospitalization, all with severe pancreatitis. On systematic review, among 451 cases of lupus pancreatitis reported, 23 (5%) fulfilled criteria for 'corticosteroid-associated lupus pancreatitis'. A majority of them had pancreatitis within 3 days of starting treatment with medium-to-high dose corticosteroids. The mortality in these patients was 37.5%.

CONCLUSION

In a small but substantial proportion of patients with lupus who develop pancreatitis, it occurs within days to weeks of starting medium-to-high dose corticosteroids. Many of these patients continue to receive corticosteroids, and some receive more aggressive immunosuppression. However, they have significant mortality, and further studies are required to identify appropriate treatment in this subgroup of patients.

Barriers to receipt of novel oral oncolytics: A single-institution quality improvement investigation

INTRODUCTION

Novel oral oncolytic agents have become the standard of care and first-line therapies for many malignancies. However, issues impacting access to these drugs are not well explored. As part of a quality improvement project in a large tertiary academic institution, we aim to identify potential barriers that delay treatment for patients who are prescribed novel oral oncolytics.

METHODS

This was a retrospective review of adults who were newly prescribed a novel oral oncolytic for Food and Drug Administration-approved indications at a single tertiary care center. Patients were identified via electronic prescription data (e-Scribe). Demographics, insurance information, and prescription dates were extracted from the electronic medical record and pharmacy claims data. Statistical analyses were performed to determine whether time-to-receipt was associated with insurance category, pharmacy transfers, cost assistance, and drug prescribed.

RESULTS

Of the 270 successfully filled prescriptions, the mean time-to-receipt was 7.3 ± 10.3 days (range: 0-109 days). Patients with Medicare experienced longer time-to-receipt (9.1 ± 13.1 days) compared to patients with commercial insurance (4.4 ± 3.3). Uninsured patients experienced the longest time-to-receipt (15.7 ± 7.8 days) overall. Pharmacy transfers and cost assistance programs were also significantly associated with longer time-to-receipt. Ten prescriptions remained unfilled 90 days after the study period and were considered abandoned.

CONCLUSION

Insurance has a significant effect on the time-to-receipt of newly prescribed novel oral oncolytics. Pharmacy transfers and applying for cost assistance are also associated with longer wait times for patients. Our retrospective analysis identifies areas of improvement for future interventions to reduce wait times for patients receiving novel oral oncolytics.

Validation of a Metastatic Assay using biopsies to improve risk stratification in patients with prostate cancer treated with radical radiation therapy

Background

Radiotherapy is an effective treatment of intermediate/high-risk locally advanced prostate cancer, however, >30% of patients relapse within 5 years. Clinicopathological parameters currently fail to identify patients prone to systemic relapse and those whom treatment intensification may be beneficial. The purpose of this study was to independently validate the performance of a 70-gene Metastatic Assay in a cohort of diagnostic biopsies from patients treated with radical radiotherapy and androgen deprivation therapy.

Patients and methods

A bridging cohort of prostate cancer diagnostic biopsy specimens was profiled to enable optimization of the Metastatic Assay threshold before further independent clinical validation in a cohort of diagnostic biopsies from patients treated with radical radiotherapy and androgen deprivation therapy. Multivariable Cox proportional hazard regression analysis was used to assess assay performance in predicting biochemical failure-free survival (BFFS) and metastasis-free survival (MFS).

Results

Gene expression analysis was carried out in 248 patients from the independent validation cohort and the Metastatic Assay applied. Ten-year MFS was 72% for Metastatic Assay positive patients and 94% for Metastatic Assay negative patients [HR = 3.21 (1.35–7.67); P = 0.003]. On multivariable analysis the Metastatic Assay remained predictive for development of distant metastases [HR = 2.71 (1.11–6.63); P = 0.030]. The assay retained independent prognostic performance for MFS when assessed with the Cancer of the Prostate Assessment Score (CAPRA) [HR = 3.23 (1.22–8.59); P = 0.019] whilst CAPRA itself was not significant [HR = 1.88, (0.52–6.77); P = 0.332]. A high concordance [100% (61.5–100)] for the assay result was noted between two separate foci taken from 11 tumours, whilst Gleason score had low concordance.

Conclusions

The Metastatic Assay demonstrated significant prognostic performance in patients treated with radical radiotherapy both alone and independent of standard clinical and pathological variables. The Metastatic Assay could have clinical utility when deciding upon treatment intensification in high-risk patients. Genomic and clinical data are available as a public resource.

A screening-level approach to quantifying risk from glacial release of organochlorine pollutants in the Alaskan Arctic

Widespread distribution of atmospherically mobilized organochlorine pollutants (OCPs) has been documented throughout the Arctic. A fraction of these OCPs have become entrained in glacial ice, and during melting, they can be released into downstream reservoirs. Though this remobilization is known, an assessment of risk from glacial meltwater to collocated human communities in the Arctic, including Alaska, had not been accomplished. Here, we use a screening-level risk assessment model for glacial watersheds, based on US Environmental Protection Agency (EPA) methodology, which we apply to the glaciated Jarvis Creek watershed of interior Alaska. Model results indicate that even with low levels of OCPs in glacial meltwater, high fish consumption by subsistence communities in the area increases the risk of cancer and hazard impacts above acceptable limits. Though this model is specific to one watershed, our results imply that further investigation of an increasing OCP signal in glacial meltwater and fish throughout the North American Arctic is warranted.

Tuberculosis-diabetes screening: how well are we doing? A mixed-methods study from North India

Setting

Public health care facilities in Sonipat District, Haryana State, India.

Objectives

To assess 1) the proportion of tuberculosis (TB) patients screened for diabetes mellitus (DM) and vice versa, 2) factors associated with screening, and 3) the enablers, barriers and solutions related to screening.

Design

A mixed-methods study with quantitative (cohort study involving record reviews of patients registered between November 2016 and April 2017) and qualitative (interviews of patients, health care providers [HCPs] and key district-level staff) components.

Results

Screening for TB among DM patients was not implemented, despite documents indicating that it had been. Of 562 TB patients, only 137 (24%) were screened for DM. TB patients registered at tertiary and secondary health centres were more likely to be screened than primary health centres. Low patient awareness, poor knowledge of guidelines among HCPs, lack of staff and inadequate training were barriers to screening. Enablers were the positive attitude of HCPs and programme staff. The key solutions suggested were to improve awareness of HCPs and patients regarding the need for screening, training of HCPs and wider availability of DM testing facilities.

Conclusion

The implementation of bidirectional screening was poor. Adequate staffing, regular training, continuous laboratory supplies for DM diagnosis and widespread publicity should be ensured.

Left inferior vena cava from the perspective of laparoscopic donor surgeon: Anatomic considerations and surgical implications

Renal vascular aberrations are not uncommon cause for rejection of living kidney donors. While screening a donor for laparoscopic nephrectomy, we encountered a rare, yet important aberration in the form of left-sided inferior vena cava (IVC). There was an initial dilemma regarding the acceptability of the donor and which side kidney to select for donation. Scant literature is available on this particular clinical scenario, and only after a detailed study of the embryology and anatomy of IVC, were we able to make an informed choice. This article highlights the surgical anatomy and clinical implications of this rare condition from the perspective of laparoscopic donor surgeon.

Pearls and paradigms in Infective Keratitis

Infective Keratitis is a commonly encountered sight-threatening ocular emergency. In developing countries, it is a major cause of corneal blindness. Empirical treatment without microbiological work up often leads to treatment failure. Indiscriminate use of steroid antibiotic combination worsens the situation and makes further management challenging. The correct line of management can be potentially sight saving for both the ophthalmologist and the patient. This article on Infective keratitis has been written keeping best practices and protocols in mind. In a very simple and concise form, it focuses on the salient features of clinical presentation of infective keratitis and the stepwise approach to subsequent management in a patient. It explains in detail the way to perform corneal scraping, the importance of the same and further management based on microbiologically proven result. The management part includes indications and methods for medical as well as surgical intervention. We aimed to share our experience in the management of patients presenting with infective keratitis in the clinic.

Advanced Selection Methodologies for DNAzymes in Sensing and Healthcare Applications

DNAzymes have been widely explored owing to their excellent catalytic activity in a broad range of applications, notably in sensing and biomedical devices. These newly discovered applications have built high hopes for designing novel catalytic DNAzymes. However, the selection of efficient DNAzymes is a challenging process but one that is of crucial importance. Initially, systemic evolution of ligands by exponential enrichment (SELEX) was a labor-intensive and time-consuming process, but recent advances have accelerated the automated generation of DNAzyme molecules. This review summarizes recent advances in SELEX that improve the affinity and specificity of DNAzymes. The thriving generation of new DNAzymes is expected to open the door to several healthcare applications. Therefore, a significant portion of this review is dedicated to various biological applications of DNAzymes, such as sensing, therapeutics, and nanodevices. In addition, discussion is further extended to the barriers encountered for the real-life application of these DNAzymes to provide a foundation for future research.

Oyster calcification of infected bone flap: A rare complication

An extremely rare case of chronic epidural empyema after cranioplasty is presented. It derives its extreme rareness from its association with calcification. This patient when presented to our department had a complaint of swelling with on and off discharging sinus for 2 months adjacent to old incision scar mark. The patient had a history of decompressive craniectomy and evacuation of acute subdural hematoma, in some other institution, 8 years back. Following that, the patient underwent cranioplasty with the exteriorized and preserved bone flap. In the meantime, he was asymptomatic. It is a unique interesting case of chronic epidural empyema with calcified walls after 8 years of long duration following cranioplasty.

Complete genome sequencing of Kaisodi virus isolated from ticks in India belonging to Phlebovirus genus, family Phenuiviridae

An unknown virus was repeatedly isolated from hard tick (Haemaphysalis spinigera) during a proactive arbovirus survey in ticks conducted in 1957, in India. The virus remained uncharacterized for a long time. The passages of this virus in different vertebrate and invertebrate cells along with human and monkey-derived cell culture showed no cytopathic effect. It was identified later to be a member of Kaisodi group among Phlebovirus genus in the family Phenuiviridae (Order: Bunyavirales) by serological methods. Due to its genomic diversity, sequencing of this virus was a challenge for a while. In this study, we were able to sequence the complete genome of this virus isolate using next-generation sequencing (NGS) platform. The unknown virus was identified to be Kaisodi virus (KASDV) using NGS analysis. De novo genome assembly derived three genomic segments for the KASDV which encode for RNA-dependent RNA polymerase, glycoprotein precursor, and nucleoprotein. Functional as well as conserved domains for Kaisodi serogroup viruses were predicted and compared to a known representative of the genus Phlebovirus. The phylogenetic tree revealed its closeness to Silverwater virus, of Kaisodi serogroup with nucleotide (69%, 62%, and 61%) and amino acid (52%, 51%, and 62%) identity for L, M, and S segment, respectively. The study demonstrates the presence of a conserved motif (⁷²TRGNK⁷⁶) around the RNA binding motif region in tick-borne phleboviruses. The intergenic region encompassing the S segment of Kaisodi serogroup was GC-rich whereas the other Phlebovirus had AT-rich genome. KASDV has the largest intergenic region and larger loops, suggesting stem-loops formed due to larger loops as a possible factor for instability and cause of transcription termination. This paper also describes the real-time RT-PCR and RT-PCR assays developed and used for the detection of KASDV RNA in ticks from Karnataka, Kerala and Maharashtra State, India. The KASDV positivity observed in the recently collected tick pools indicates that the KASDV, isolated from Karnataka state in 1957, is also circulating in the adjoining Kerala state. On the basis of the current study, it should be possible to develop diagnostic assays which would facilitate an in-depth field survey exploring the veterinary and medical significance of KASDV.

Reverse hybrid total hip arthroplasty

Aims

This study aimed to evaluate implant survival of reverse hybrid total hip arthroplasty (THA) at medium-term follow-up.

Patients and Methods

A consecutive series of 1082 THAs in 982 patients with mean follow-up of 7.9 years (5 to 11.3) is presented. Mean age was 69.2 years (21 to 94). Of these, 194 (17.9%) were in patients under 60 years, 663 (61.3%) in female patients and 348 (32.2%) performed by a trainee. Head size was 28 mm in 953 hips (88.1%) or 32 mm in 129 hips (11.9%). Survival analysis was performed and subgroups compared using log rank tests.

Results

Ten-year survival (122 hips at risk) was 97.2% (95% confidence interval (CI) 95.77 to 98.11) for all-cause revision. There was no difference in survival by age (p = 0.50), gender (p = 0.78), head size (p = 0.63) or surgeon grade (p = 0.36). No acetabular components underwent revision for aseptic loosening in the entire series. Four (0.4%) aseptic stem failures occurred early at a mean of 2.5 years (0.6 to 4.8) and were associated with age under 60 years (p = 0.015). There was no difference in survival by gender (p = 0.12), head size (p = 0.43) or surgeon grade (p = 0.77) for stem revision.

Conclusion

This is the largest reported study into reverse hybrid THA and it confirms successful outcomes, irrespective of age, gender, head size and surgeon grade. Cite this article: Bone Joint J 2018;100-B:1010-17.

Meeting report, “First Indian national conference on cervical cancer management - expert recommendations and identification of barriers to implementation”

Objective

In India, cervical cancer accounts for almost 14% of all female cancer cases. Although poverty continues to cast a wide net over the Indian subcontinent, the preceding three decades have borne witness to improvements in nutrition and sanitation for many citizens. However, due to an absence of a national immunization program to cover human papillomavirus (HPV) vaccination and lack of accessible cervical cancer screening, the disease is characterized by late detection, lack of access to affordable and quality health care, and high mortality rates. Treatment of cervical cancer is stage-specific and depends on the patient’s age, desire to preserve fertility, overall health, the clinician’s expertise, and accessibility to resources. There is a paucity of uniform treatment protocols for various stages of cervical cancer in India. Considering all these parameters, a need to optimize treatment paradigms for the Indian population emerged.

Methods/materials

Three expert panel meetings were held in different regions of India from 2016 to 2017. They were comprised of 15 experts from across the country, and included surgical oncologists, radiation oncologists, and medical oncologists. The panel members reviewed the literature from both national and global sources, discussed their clinical experience and local practices and evaluated current therapeutic options and management gaps for women diagnosed with cervical cancer.

Results

This article summarizes the expert opinion from these meetings. It discusses the available resources and highlights the current therapeutic options available for different cervical cancer stages: early stage disease, locally advanced tumors, recurrent/persistent/metastatic cancer. An Indian consensus governing treatment options emerged, including guidelines for use of the only approved targeted therapy in this disease, the anti-angiogenesis drug, bevacizumab.

Conclusions

The panel concluded that given the availability of state-of-the-art imaging modalities, surgical devices, radiotherapeutics, and novel agents in several population-dense urban centers, a uniform, multi-disciplinary treatment approach across patient care centers is ideal but not realistic due to cost and a paucity of third party payors for most Indian citizens. Preventative strategies including visual inspection with acetic acid to screen for precursor lesions (i.e., cervical intraepithelial neoplasia) with immediate referral for cervical cryotherapy and possible large-scale roll-out of the HPV vaccine in the near future can be expected to reduce mortality rates significantly in this country.

When Environmental Forces Collide

Multiple factors often interact to amplify the effects of severe storms, droughts, and other extreme water-related events.

Understanding Combustion of H2/O2 Gases inside Nanobubbles Generated by Water Electrolysis Using Reactive Molecular Dynamic Simulations

This work explored the mechanism of spontaneous combustion of hydrogen-oxygen mixtures inside nanobubbles (which were generated by water electrolysis) using reactive molecular dynamic simulations based on the first-principles derived reactive force field ReaxFF. The effects of surface-assisted dissociation of H₂ and O₂ gases that produced H and O radicals were examined. Additionally, the ignition outcome and species evolution as a function of the initial system pressure (or bubble size) were studied. A significant amount of hydrogen peroxide (H₂O₂), 6-140 times water (H₂O), was observed in the combustion products. This was attributed to the low-temperature (∼300 K) and high-pressure (2-80 atm) conditions at which the chemical reactions were taking place. In addition, the rate of consumption of H₂ and O₂ molecules was found to increase with an increase in added H and O radical concentrations and initial system pressure. The rate at which heat was being lost from the combustion chamber (nanobubbles) was also compared to the rate at which heat was being released from the chemical reactions. Only a slight rise in the reaction temperature was observed (∼68 K), signifying that, at such small scales, heat losses dominate. The resulting chemistry was quite different from macroscopic combustion, which usually takes place at a much higher temperatures of above 1000 K.

New cytochalasin from Rosellinia sanctae-cruciana, an endophytic fungus of Albizia lebbeck

AIM

To explore the potential of Rosellinia sanctae-cruciana an endophytic fungus associated with Albizia lebbeck for pharmaceutically important cytotoxic compounds.

METHODS AND RESULTS

One novel cytochalasin, named jammosporin A (1) and four known analogues (2-5) were isolated from the culture of the endophytic fungus R. sanctae-cruciana, harboured from the leaves of the medicinal plant A. lebbeck. Their structures were elucidated by extensive spectroscopic analyses including one-dimensional and two-dimensional nuclear magnetic resonance data along with MS data and by comparison with literature reports. In preliminary screening the ethyl acetate extract of the fungal culture was tested for cytotoxic activity against a panel of four cancer cell lines (MOLT-4, A549, MIA PaCa-2 and MDA-MB-231), and found to be active against MOLT-4 with an IC₅₀ value of 10 μg ml^-1 . Owing to the remarkable cytotoxic activity of the extract the isolated compounds (1-5) were evaluated for their cytototoxicity against the MOLT-4 cell line by MTT assay. Interestingly, compounds 1-2, 4 and 5 showed considerable cytotoxic potential against the human leukaemia cancer cell line (MOLT-4) with IC₅₀ values of 20·0, 10·0, 8·0 and 6·0 μmol l^-1 , respectively, while compound 3 showed an IC₅₀ value of 25 μmol l^-1 . This is the first report of the existence of this class of secondary metabolites in R. sanctae-cruciana fungus.

CONCLUSION

This study discovered a novel compound, named jammosporin A, isolated for the first time from R. sanctae-cruciana, an endophytic fungus of A. lebbeck with anticancer activity against the MOLT-4 cell line.

SIGNIFICANCE AND IMPACT OF THE STUDY

Rosellinia sanctae-cruciana represents an interesting source of a new compound with bioactive potential as a therapeutic agent against a human leukaemia cancer cell line (MOLT-4).

Obstructive Sleep Apnea in Children with Nocturnal Enuresis

There is increasing evidence on the association of monosymptomatic nocturnal enuresis (MNE) with obstructive sleep apnea. In this communication, we share our experience of four patients with Primary monosymptomatic nocturnal enuresis (PMNE) with positive Sleep-related breathing disorder (SRBD) score who underwent detailed polysomnography, and were either refractory to desmopressin treatment or relapsed on discontinuation of desmopressin.