Irreversible delayed complete heart block secondary to jailed first septal perforator following PCI of the left anterior descending coronary artery

Permanent complete heart block (CHB) secondary to the loss of first septal perforator after percutaneous coronary intervention (PCI) of the left descending artery (LAD) is an extremely rare complication. We describe a case report where a patient underwent PCI of proximal LAD, complicated by loss of first septal perforator, septal infarction, and bifasicular block, which progressed to symptomatic delayed CHB. One week later, the patient required implantation of a permanent pacemaker following failure to wean off the transvenous temporary pacing maker.     

Critical review on the chemical reduction of nitroaniline

Conversion of nitroaniline (NA), a highly toxic pollutant that has been released into aquatic systems due to unmanaged industrial development in recent years, into the less harmful or a useful counterpart is the need of the hour. Various methods for its conversion and removal have been explored. Owing to its nominal features of advanced effectiveness, the chemical reduction of 4-NA using various different nanocatalytic systems is one such approach that has attracted tremendous interest over the past few years. The academic literature has been confined to case studies involving silver (Ag) and gold (Au) nanoparticles, as these are the two most widely used materials for the synthesis of nanocatalytic assemblies. Focus has also been given to sodium borohydride (NaBH₄), which is used as a reductant during the chemical reduction of NA. This systematic review summarizes the fundamentals associated with the catalytic degradation of 4-NA, and presents a comprehensive and critical study of the latest modifications used in the synthesis of these catalytic systems. In addition, the kinetics, mechanisms, thermodynamics, as well as the future directions required for understanding this model reaction, have been provided in this particular study.

Schematic illustration of catalytic reduction of 4-NA in the presence of nanocatalysts and a reducing agent.     

Identification and bioactivity evaluation of secondary metabolites from Antarctic-derived Penicillium chrysogenum CCTCC M 2020019

Extracts from Antarctic-derived Penicillium chrysogenum CCTCC M 2020019 showed potent antibacterial bioactivities. We report herein the isolation of chrysonin (1), a new compound containing a pair of enantiomers 6S- and 6R-chrysonin (1a and 1b) featuring an unprecedented eight-membered heterocycle fused with a benzene ring. Compound 2, a mixture consisting of a new zwitterionic compound chrysomamide (2a) and N-[2-trans-(4-hydroxyphenyl) ethenyl] formamide (2b) in a ratio around 1 : 2.8, was isolated together with seven known compounds 3–9. Chemical structures of all compounds were determined by comprehensive spectroscopic analyses. The isolated compounds were evaluated for antimicrobial, cytotoxic and alpha-glucosidase inhibition activities. Chrysonin (1) showed moderate alpha-glucosidase inhibitory activity. The dominant product xanthocillin X (4) displayed potent inhibition activities against Gram-negative pathogens Acinetobacter baumannii, Klebsiella pneumoniae, and Pseudomonas aeruginosa with MIC values at 0.125 μg mL⁻¹. Xanthocillins X (4) and Y1 (5) also showed significant cytotoxicities against four cancer cell lines with IC₅₀ values ranging from 0.26 to 5.04 μM. This study highlights that microorganisms from polar regions are emerging as a new resource for the discovery of natural products combating human pathogens.

The unprecedented eight-membered heterocyclic chrysonin (1) was isolated from an Antarctic fungus that also produced xanthocillins 4 and 5 as potent inhibitors against Gram-negative pathogens.     

Promising performance of chemically exfoliated Zr-doped MoS2 nanosheets for catalytic and antibacterial applications

Nanostructured materials incorporated with biological reducing agents have shown significant potential for use in bactericidal applications. Such materials have also demonstrated considerable efficacy to counter effects of chemical toxicity. In this study, nanostructured molybdenum disulfide (MoS₂) was doped with various concentrations (2.5, 5, 7.5, 10 wt%) of zirconium (Zr) using a hydrothermal route in order to assess its antimicrobial and catalytic potential. Doped and control samples were characterized with various techniques. X-ray diffraction (XRD) analysis confirmed the presence of the hexagonal phase of MoS₂ and identification of various functional groups and characteristic peaks (Mo bonding) was carried out using FTIR spectra. Micrographs obtained from FESEM and HR-TEM showed a sheet-like surface morphology, while agglomeration of nanosheets was observed upon doping with nanoparticles. To seek further clarity regarding the layered features of S–Mo–S planes, the defect densities and electronic band structure of pure MoS₂ and doped MoS₂ samples were investigated through Raman analysis. Optical properties of Zr-doped MoS₂ nanosheets were assessed using a UV-vis spectrophotometer and the results indicated a red-shift, i.e., movement of peaks towards longer wavelengths, of the material. Dynamics of migration and recombination of excited electron–hole pairs were investigated using PL spectroscopy, which was also used to confirm the presence of exfoliated nanosheets. In addition, the synthetic dye degradation potential of pure and doped samples was investigated in the presence of a reducing agent (NaBH₄). It was noted that doped MoS₂ showed superior catalytic activity compared to undoped MoS₂. The nanocatalyst synthesized in this study exhibited enhanced antibacterial activity against E. coli and S. aureus at high concentrations (0.5, 1.0 mg/50 μl). The present study suggests a cost-effective and environmentally friendly material that can be used to remove toxins such as synthetic dyes and tannery pollutants from industrial wastewater.

Nanostructured materials incorporated with biological reducing agents have shown significant potential for use in bactericidal applications.     

True benefit or selection bias: an analysis of laparoscopic versus open splenectomy from the ACS-NSQIP

Background

By virtue of the benefits associated with minimally invasive approaches, laparoscopic splenectomy (LS) is believed to have better patient-related outcomes compared to open splenectomy (OS). However, there are limited data directly comparing the two techniques.

Methods

Patients who underwent elective LS and OS between 2005 and 2010 were identified from the public use file of the ACS-NSQIP database using the Current Procedural Terminology codes 38120 and 38100. Patients who had concomitant procedures were excluded. Because of the nonrandom assignment of surgical techniques, a selection bias could have been responsible for the differences in patient outcomes. Therefore, patient characteristics and comorbidities that were available and could have been potential confounders were compared and regression analysis was performed to determine independent risk factors associated with serious and overall morbidity as well as mortality.

Results

During the study period 1,644 and 851 patients underwent LS and OS, respectively. Compared to patients who underwent LS, patients who had OS had a longer median length of hospital stay (3 vs. 6 days, P < 0.0001) and higher incidences of serious (7 vs. 17 %, P < 0.0001) and overall morbidity (12 vs. 25 %, P < 0.0001) and mortality (1.4 vs. 3.3 %, P = 0.02). However, there were certain significant differences in the characteristics and comorbidities of the patients that could have confounded outcomes. On regression analysis, OS was not associated with higher mortality (OR = 1.43, 95 % CI 0.7–2.7, P = 0.28) but was associated with higher serious morbidity (OR = 1.8, 95 % CI 1.4–2.3, P = 0.001) and overall morbidity (OR = 2.0, 95 % CI 1.6–2.4, P = 0.0001).

Conclusion

After adjusting for available confounders, patients who underwent LS had lower morbidity and similar mortality rates. Although certain confounders such as previous surgical history, underlying pathology, and spleen size could still have potentially influenced outcomes, the data suggest that patient outcomes after LS are excellent and when technically possible a minimally invasive technique should be the preferred approach for splenectomy.     

High performance p-channel and ambipolar OFETs based on imidazo[4,5-f]-1,10-phenanthroline-triarylamines

A series of phenanthroline functionalized triarylamines (TAA) has been designed and synthesised to evaluate their OFET characteristics. Solution processed OFET devices have exhibited p-channel/ambipolar behaviour with respect to the substituents, in particular methoxyphenyl substitution resulted with highest mobility (μ_h) up to 1.1 cm² V⁻¹ s⁻¹ with good I_on/off (10⁶) ratio. These compounds can be potentially utilized for the fabrication of electronic devices.

A series of phenanthroline functionalized triarylamines (TAA) has been designed and synthesised to evaluate their OFET characteristics. Solution processed OFET devices have exhibited p-channel/ambipolar behaviour with respect to the substituents.     

Comparison of different methods for measurement of electrolytes in patients admitted to the intensive care unit

Objectives:

To investigate whether electrolyte levels measured by using blood gas analyzers (ABG) and auto-analyzers (AA) are equivalent and can be used interchangeably.

Methods:

This observational prospective study was conducted in 100 patients admitted to the Intensive Care Unit, Adnan Menderes University School of Medicine, Aydin, Turkey, between March and August 2014. Samples for both AA and ABG analyzers were collected simultaneously from invasive arterial catheters of patients. The electrolyte levels were measured by using 2 methods.

Results:

The mean sodium level measured by ABG was 136.1±6.3 mmol/L and 137.8±5.4 mmol/L for AA (p=0.001). The Pearson’s correlation coefficient was 0.561 (p<0.001). The Bland-Altman 95% limits of agreement were -9.4 to 12.6 mmol/L. The mean potassium levels measured by ABG was 3.4±0.7 mmol/L and AA was 3.8±0.7 mmol/L (p=0.001). The Bland-Altman comparison limits were -0.58 to 1.24 and the associated Pearson’s correlation coefficient was 0.812 (p<0.001).

Conclusion:

The results of the 2 analyzing methods, in terms of sodium, were not equivalent and could not be used interchangeably. However, according to the statistical analyses results, by including, but not blindly trusting these findings, urgent and vital decisions could be made by the potassium levels obtained from the BGA, but a simultaneous follow-up sample had to be sent to the central laboratory for confirmation.Electrolytes are very important for the continuation of the physiological functions of the human body. They play vital roles in: regulation of the cell membrane potential, steady process of neurohormonal pathways, energy transformation and the fluid, and acid-base balance in the body. Signs and symptoms of electrolyte disorders may be nonspecific in an intensive care unit (ICU) patient.1-3 The therapies directed for maintaining vital organ functions affect the electrolyte balance. Consequently, electrolyte disorders are more common in critically ill patients than non-critically ill patients.1 The incidence of electrolyte disorders is nearly 25% in ICU patients.2 In recent studies,4-6 it is shown that in ICU patients, serum sodium and potassium levels are significant predictors of mortality. Therefore, prompt and complete correction of electrolyte disorders in ICU patients is vitally important. Under these circumstances, the importance of obtaining the results of serum electrolyte levels at the earliest is obvious. In routine application, serum electrolytes are measured by the indirect ion-sensing (ISE) method using auto-analyzers (AA) located in the central laboratories of hospitals. In this analyzing method, the processing time is longer because of a delay in the transportation of the samples to the central laboratory on account of several reasons.7 Hence, point-of-care (POC) testing methods, such as, arterial blood gas (ABG) analyzers have been increasingly used in the daily assessments of ICU patients. Blood gas analyzers; use the direct ISE method with short processing time that provides time and rapidity to the physician in the patient’s treatment decisions.7,8 The United States Clinical Laboratory Improvement Amendments (US CLIA) accepts a 0.5 mmol/l difference in the measured potassium levels and a 4 mmol/l difference in the measured sodium levels, in the gold standard measure of the standard calibration solution.9 In some recent studies, the data revealed the difference in the electrolyte levels between the ABG and AA results.10,11 Furthermore, there are also studies that suggest that there is no significant difference between these measuring methods.12,13 Physicians want to trust the veracity of the ABG results of electrolytes such as sodium and potassium because, by this method, the delay in reaching the results is surpassed, and risks arising from this delay may be reduced. However, the results of the above-mentioned studies are confusing and still a diagnostic challenge for physicians. On account of the hesitation by the physicians, we decided to investigate whether the sodium and potassium levels measured by using ABG and AA were equivalent. We conducted a prospective study comparing the electrolyte level results measured in the arterial blood samples by 2 different methods. We tried to notice all limitations of previous similar studies and designed our study according to these points. Thereby, we aimed to improve the accuracy of our study results.     

Pacemaker infection secondary to burkholderia pseudomallei

Infection is a relatively rare but devastating complication of intracardiac device implantation. Burkholderia pseudomallei is the organism which causes melioidosis, an endemic and lethal infection in the tropics. We describe a case of pacemaker infection secondary to Burkholderia pseudomallei, which was treated by explantation of the device and appropriate antimicrobial therapy.     

Reprint – Bipolar vs. monopolar transurethral resection of the prostate for lower urinary tract symptoms secondary to benign prostatic obstruction: A Cochrane review

IntroductionThere remains uncertainty regarding the differences in patient outcomes between monopolar transurethral resection of the prostate (MTURP) and bipolar TURP (BTURP) in the management of lower urinary tract symptoms (LUTS) secondary to benign prostatic obstruction (BPO).MethodsA systematic literature search was carried out up to March 19, 2019. Methods in the Cochrane Handbook were followed. Certainty of evidence (CoE) was assessed using the GRADE approach.ResultsA total of 59 randomized controlled trials (RCTs) with 8924 participants were included. BTURP probably results in little to no difference in International Prostate Symptom Score (IPSS) at 12 months (mean difference −0.24, 95% confidence internal [CI] −0.39–−0.09; participants=2531; RCTs=16; moderate CoE) or health-related quality of life (HRQOL) at 12 months (mean difference −0.12, 95% CI −0.25–0.02; participants=2004, RCTs=11; moderate CoE), compared to MTURP. BTURP probably reduces TUR syndrome (relative risk [RR] 0.17, 95% CI 0.09–0.30; participants= 6,745, RCTs=44; moderate CoE) and blood transfusions (RR 0.42, 95% CI 0.30–0.59; participants=5727, RCTs=38; moderate CoE), compared to MTURP. BTURP may carry similar risk of urinary incontinence at 12 months (RR 0.20, 95% CI 0.01–4.06; participants=751; RCTs=4; low CoE), re-TURP (RR 1.02, 95% CI 0.44–2.40; participants=652, RCTs=6, I²=0%; low CoE) and erectile dysfunction (International Index of Erectile Function [IIEF-5]) at 12 months (mean difference 0.88, 95% CI −0.56–2.32; RCTs=3; moderate CoE), compared to MTURP.ConclusionsBTURP and MTURP probably improve urological symptoms to a similar degree. BTURP probably reduces TUR syndrome and blood transfusion slightly postoperatively. The moderate certainty of evidence available for primary outcomes suggests no need for further RCTs comparing BTURP and MTURP.