Expression and characterization of novel chimeric endolysin CHAPk-SH3bk against biofilm-forming methicillin-resistant Staphylococcus aureus.

The continuous evolution of antibiotic resistance in methicillin-resistant Staphylococcus aureus (MRSA) due to the misuse of antibiotics lays out the need for the development of new antimicrobials with higher activity and lower resistance. In this study, we have expressed novel chimeric endolysin CHAPk-SH3bk derived from LysK to investigate its antibacterial activity against planktonic and biofilm-forming MRSA. The molecular docking and MD simulation results identified critical amino acids (ASP47, ASP56, ARG71, and Gly74) of CHAPk domain responsible for its catalytic activity. Chimeric endolysin CHAPk-SH3bk showed an effective binding to peptidoglycan fragment using 14 hydrogen bonds. The in-vitro antibacterial assays displayed higher activity of CHAPk against planktonic MRSA with 2-log10 reduction in 2 h. Both CHAPk and CHAPk-SH3bk displayed bactericidal activity against MRSA with ∼4log10 and ∼3.5log10 reduction in 24 h. Biofilm reduction activity displayed CHAPk-SH3bk reduced 33 % and 60 % of hospital-associated ATCC®BAA-44™ and bovine origin SA1 respectively. The CHAPk treatment reduced 47 % of the preformed biofilm formed by bovine-origin MRSA SA1. This study indicates an effective reduction of preformed MRSA biofilms of human and animal origin using novel chimeric construct CHAPk-SH3bk. Stating that the combination and shuffling of different domains of phage endolysin potentially increase its bacteriolytic effectiveness against MRSA.

A research landscape bibliometric analysis on climate change for last decades: Evidence from applications of machine learning.

Climate change (CC) is one of the greatest threats to human health, safety, and the environment. Given its current and future impacts, numerous studies have employed computational tools (e.g., machine learning, ML) to understand, mitigate, and adapt to CC. Therefore, this paper seeks to comprehensively analyze the research/publications landscape on the MLCC research based on published documents from Scopus. The high productivity and research impact of MLCC has produced highly cited works categorized as science, technology, and engineering to the arts, humanities, and social sciences. The most prolific author is Shamsuddin Shahid (based at Universiti Teknologi Malaysia), whereas the Chinese Academy of Sciences is the most productive affiliation on MLCC research. The most influential countries are the United States and China, which is attributed to the funding activities of the National Science Foundation and the National Natural Science Foundation of China (NSFC), respectively. Collaboration through co-authorship in high-impact journals such as Remote Sensing was also identified as an important factor in the high rate of productivity among the most active stakeholders researching MLCC topics worldwide. Keyword co-occurrence analysis identified four major research hotspots/themes on MLCC research that describe the ML techniques, potential risky sectors, remote sensing, and sustainable development dynamics of CC. In conclusion, the paper finds that MLCC research has a significant socio-economic, environmental, and research impact, which points to increased discoveries, publications, and citations in the near future.

Current management of appendicular mas - a narrative review.

Appendicular mass is considered as one of the complications of acute appendicitis but there is no consensus on the optimal management of this condition. The management of this condition has always been conservative management with interval appendectomy as popularized by Oschner and Sheerin. The need for interval appendectomy has now been questioned, and an emerging trend has been early appendectomy by laparoscopic method. There are no guidelines on the management of appendicular mass and treatment is decided by the surgeon. We have conducted a narrative review to investigate what is the current practice in the management of appendicular mass.

A systematic review on antimicrobial activities of green synthesised Selaginella silver nanoparticles.

BACKGROUND: Metallic nanoparticles from different natural sources exhibit superior therapeutic options as compared to the conventional methods. Selaginella species have attracted special attention of researchers worldwide due to the presence of bioactive molecules such as flavonoids, biflavonoids, triterpenes, steroids, saponins, tannins and other secondary metabolites that exhibit antimicrobial, antiplasmodial, anticancer and anti-inflammatory activities. Environment friendly green synthesised silver nanoparticles from Selaginella species provide viable, safe and efficient treatment against different fungal pathogens. OBJECTIVE: This systematic review aims to summarise the literature pertaining to superior antifungal ability of green synthesised silver nanoparticles using plant extracts of Selaginella spp. in comparison to both aqueous and ethanolic raw plant extracts by electronically collecting articles from databases. METHODS: The recommendations of the Preferred Reporting Items for Systematic Reviews and Meta-Analysis were taken into consideration while preparing this review. The titles and abstracts of the collected data were stored in Endnote20 based on the inclusion and exclusion criteria. The search strategy included literature from established sources like PubMed, Google Scholar and Retrieval System Online using subject descriptors. RESULTS: The search yielded 60 articles with unique hits. After removal of duplications, 46 articles were identified, 40 were assessed and only seven articles were chosen and included in this review based on our eligibility criteria. CONCLUSION: The physicochemical and preliminary phytochemical investigations of Selaginella suggest higher drug potency of nanoparticles synthesised from plant extract against different diseases as compared to aqueous and ethanolic plant extracts. The study holds great promise as the synthesis of nanoparticles involves low energy consumption, minimal technology and least toxic effects.

Novel aadA5 and dfrA17 variants of class 1 integron in multidrug-resistant Escherichia coli causing bovine mastitis.

Mobile genetic elements (MGEs) are associated with the emergence of multidrug resistance in extended-spectrum ß-lactamase (ESBL)-producing Enterobacteriaceae. This study explores the role of class 1 integrons and IS26 elements in breaching taxonomic barriers. A total of 110 E. coli bacteria were isolated from 300 clinical mastitis milk samples. The 98% E. coli isolates were extended-spectrum beta-lactamase- producers. About 83% of these isolates carried co-resistance for fluoroquinolones. The co-existence of (extended-spectrum beta-lactamase + quinolone resistance determining region mutations) and (extended-spectrum beta-lactamase + plasmid-mediated quinolone resistance genes) was found in 76% and 44% of isolates, respectively. The MGEs were detected in 88% of isolates with IS26 in 82% and class 1 integrase in 40% of isolates. The types of class 1 integron gene cassettes detected includes dfrA7, (dfrA17 + aadA5), and (dfrA1 + aadA1). We discovered 2 and 4 novel variants of the dfrA17 and aadA5 genes, respectively. We report a variant of aadA5 with mutation E235G in the Indian subcontinent earlier reported only in a human clinical isolate from Belgium. About 19 isolates carried IS26 linked to integrase gene intI1 with an internal deletion of 265 bp in the 5`CS of integrase gene intI1, earlier reported only in E. coli ST131 isolates from human clinical, wastewater samples. This study suggests intercontinental dissemination of antibiotic resistant genes (ARGs) across different microbiomes via mobile genetic elements. KEY POINTS: • The role of mobile genetic elements in the emergence of multidrug-resistant E. coli in bovine mastitis. • Novel variants of the aadA5 (aminoglycoside adenyl transferase) and dfrA17 (dihydrofolate reductase) genes were identified in pathogenic E. coli isolated from bovine mastitis in class 1 integron gene cassette. • Sequence analysis of mobile genetic components revealed the physical connection between IS26 and intI1 genes with an internal deletion in 5'CS of class 1 integrase.

Emergency management plan for paediatric patients with tracheostomies during the coronavirus disease 2019 pandemic.

OBJECTIVES: Paediatric patients with tracheostomies are a vulnerable group. During the coronavirus disease 2019 pandemic, healthcare workers can be anxious about viral transmission from secretions and aerosols emerging from the open airway. This paper aims to share a systematic approach to decrease staff exposure and optimise care of these patients. METHODS: Three documents were developed: a generic tracheostomy management plan detailing troubleshooting; a personalised management plan with customised recommendations; and a guide for tracheostomy tube change to minimise aerosol production. RESULTS: The plan was distributed to 31 patients (age range, 11 months to 17 years) including 23 (74.2 per cent) with uncuffed tubes and 9 (29 per cent) on long-term ventilation. There have been 10 occasions in which the plan was utilised and influenced management. CONCLUSION: A structured approach to emergency presentations during the coronavirus disease 2019 pandemic may safeguard paediatric patients from unnecessary manipulation of their tracheostomy tube, minimise viral exposure and allow provision of expeditious care.

Global epidemiology of CTX-M-type ß-lactam resistance in human and animal.

CTX-M ESBL are widely found in animal and human infections. For better understanding of CTX-M variations and epidemiology, a total of 2210 CTX-M sequences were retrieved from NCBI as at 20 December 2020. The maximum incidences of CTX-M were reported in China (n = 508), USA (n = 354) and Japan (n = 180). Single amino acid substitution in the domain region of CTX-M ESBL lead to survival benefits to the bacteria. A total of 31 different variations were found of which D240G was the most common followed by A77V and V103I substitutions. The variations in CTX-M enzymes were explained continent-wise revealing the maximum variation reported in America followed by Asia and Europe of which D240G substitution was the most prevalent. India contained only three variations (E166A, P167S D240G) found in New Delhi, Karnataka, West Bengal and Tamil Nadu. The P167 and D240 were under strong positive selection with dN/dS calculation.

Simultaneous estimation of ZY-19489 and its active metabolite ZY-20486 in human plasma using LC-MS/MS, a novel antimalarial compound.

Aim: ZY-19489 is a new antimalarial drug candidate and selective LC-MS/MS method was established for estimation of ZY-19489 and its metabolite in human plasma. Materials & methods: LLE was employed for extraction, mass spectrometric quantification performed using positive ionization mode and DCP-IMP was used as an internal standard. The chromatographic separation was achieved using mobile phase 5 mM ammonium formate in water and 0.1% v/v ammonia solution in methanol:acetonitrile (90:10% v/v) and column Agilent Zorbex Extended C18, 3.5 µm, 100 × 4.6 mm with a 6-min run time. Results: The calibration curve of ZY-19489 was linear over range 1-500 ng/ml and 2-200 ng/ml for metabolite. Assay was reproducible, selective and devoid of matrix effect. Conclusion: The validated assay was implemented for clinical sample analysis derived from healthy human subjects and parasitemia-induced subjects.

Novel use of high-flow nasal cannula therapy in the management of pyriform aperture stenosis: case report.

BACKGROUND: Pyriform aperture stenosis is a rare form of congenital nasal obstruction; it poses a management dilemma for otolaryngologists and physicians alike. It can result in poor weight gain and potentially life-threatening airflow obstruction. The challenge lies in the difficulty to predict which patients will require invasive operative management versus conservative therapy alone. CASE REPORT: This case demonstrates the successful use of high-flow nasal cannula therapy in a young child with pyriform aperture stenosis.

Rapid nongenomic modulation by neurosteroids of dendritic spines in the hippocampus: Androgen, oestrogen and corticosteroid.

Memories are stored in synapses that consist of axon terminals and dendritic spines. Dendritic spines are postsynaptic structures of synapses and are essential for synaptic plasticity and cognition. Therefore, extensive investigations concerning the functions and structures of spines have been performed. Sex steroids and stress steroids have been shown to modulate hippocampal synapses. Although the rapid modulatory action of sex steroids on synapses has been studied in hippocampal neurones over several decades, the essential molecular mechanisms have not been fully understood. Here, a description of kinase-dependent signalling mechanisms is provided that can explain the rapid nongenomic modulation of dendritic spinogenesis in rat and mouse hippocampal slices by the application of sex steroids, including dihydrotestosterone, testosterone, oestradiol and progesterone. We also indicate the role of synaptic (classic) sex steroid receptors that trigger these rapid synaptic modulations. Moreover, we describe rapid nongenomic spine modulation by applying corticosterone, which is an acute stress model of the hippocampus. The explanations for the results obtained are mainly based on the optical imaging of dendritic spines. Comparisons are also performed with results obtained from other types of imaging, including electron microscopic imaging. Relationships between spine modulation and modulation of cognition are discussed. We recognise that most of rapid effects of exogenously applied oestrogen and androgen were observed in steroid-depleted conditions, including acute slices of the hippocampus, castrated male animals and ovariectomised female animals. Therefore, the previously observed effects can be considered as a type of recovery event, which may be essentially similar to hormone replacement therapy under hormone-decreased conditions. On the other hand, in gonadally intact young animals with high levels of endogenous sex hormones, further supplementation of sex hormones might not be effective, whereas the infusion of blockers for steroid receptors or kinases may be effective, with respect to suppressing sex hormone functions, thus providing useful information regarding molecular mechanisms.

Multimodal signalling in estrildid finches: song, dance and colour are associated with different ecological and life-history traits.

Sexual traits (e.g. visual ornaments, acoustic signals, courtship behaviour) are often displayed together as multimodal signals. Some hypotheses predict joint evolution of different sexual signals (e.g. to increase the efficiency of communication) or that different signals trade off with each other (e.g. due to limited resources). Alternatively, multiple signals may evolve independently for different functions, or to communicate different information (multiple message hypothesis). We evaluated these hypotheses with a comparative study in the family Estrildidae, one of the largest songbird radiations, and one that includes many model species for research in sexual selection and communication. We found little evidence for either joint evolution or trade-offs between song and colour ornamentation. Some negative correlations between dance repertoire and song traits may suggest a functional compromise, but generally courtship dance also evolved independently from other signals. Instead of correlated evolution, we found that song, dance and colour are each related to different socio-ecological traits. Song complexity evolved together with ecological generalism, song performance with investment in reproduction, dance with commonness and habitat type, whereas colour ornamentation was shown previously to correlate mostly with gregariousness. We conclude that multimodal signals evolve in response to various socio-ecological traits, suggesting the accumulation of distinct signalling functions.

Relationship between the changes in blood flow and volume in the finger during a Braille character discrimination task.

PURPOSE: We hypothesized that skin blood flow (SBF) of fingers are modulated during concentrated finger perception and that the changes in SBF reflect fluctuations in finger volume (FV). The aim of this study, therefore, was examine the relationship between the changes in SBF and FV during Braille reading. METHODS: We measured SBF of the finger, cutaneous vascular conductance (CVC), FV, and arterial blood pressure during Braille reading performed under blind conditions in thirty healthy subjects. The subjects were instructed to read a flat plate with raised letters (Braille reading) for 15 seconds using their forefinger, and to touch a blank plate as a control for the Braille discrimination procedure. RESULTS: Arterial blood pressure slightly increased during Braille reading but remained unchanged during the touching of the blank plate. SBF, CVC, and FV were reduced during Braille reading (decreased by -26%, -29%, and -0.3 mL/100 mL respectively). Furthermore, a significant relationship was observed between the changes in SBF and FV (r=.613) during Braille reading. CONCLUSION: These results suggested that SBF of fingers is modulated during concentrated finger perception, and that the variability of blood flow reflects the response in FV.

Haplotype-based, case-control study of the receptor (calcitonin) activity-modifying protein (RAMP) 1 gene in essential hypertension.

The adrenomedullin receptor is a complex molecule that comprises the calcitonin-receptor-like receptor (CRLR) and the receptor-activity-modifying protein (RAMP). RAMP1 is a vasodilation factor, and RAMP1-deficient mice (RAMP1(-/-)) exhibit inflammatory responses with a significant transient increase in serum calcitonin-gene-related peptide levels and proinflammatory cytokines when compared with RAMP1(+/+) mice. The purpose of the present study was to investigate the relationships between essential hypertension (EH) and RAMP1 gene single-nucleotide polymorphisms (SNPs) or haplotypes in a Japanese population via a case-control study. Based on a database search of the National Center of Biotechnology Information website and the HapMap project, we chose six RAMP1 gene SNPs and performed an association study involving 263 patients with EH and 267 age-matched normotensive (NT) subjects. There was no significant difference between the EH and NT groups with regard to overall distribution of genotypes or SNP alleles. However, the haplotype-based case-control analysis revealed that there was a significant difference between the EH and NT groups with regard to overall distribution of the allele combinations at three SNPs-rs3754701-rs3769048-rs10199956-(P=0.002). The T-A-T haplotype was significantly more common in the EH group (10.3%) than in the NT control group (6.1%) (P=0.047). These results suggested that this T-A-T RAMP1 gene haplotype might have utility as a genetic marker for EH and that the RAMP1 gene or a neighbouring gene may be associated with increased susceptibility to EH.

An efficient method for generating a germ cell depleted animal model for studies related to spermatogonial stem cell transplantation.

BACKGROUND: Spermatogonial stem cell (SSC) transplantation (SSCT) has become important for conservation of endangered species, transgenesis and for rejuvenating testes which have lost germ cells (Gc) due to gonadotoxic chemotherapy or radiotherapy during the prepubertal phase of life. Creating a germ cell-depleted animal model for transplantation of normal or gene-transfected SSC is a prerequisite for such experimental studies. Traditionally used intraperitoneal injections of busulfan to achieve this are associated with painful hematopoietic toxicity and affects the wellbeing of the animals. Use of testicular busulfan has been reported recently to avoid this but with a very low success rate of SSCT. Therefore, it is necessary to establish a more efficient method to achieve higher SSCT without any suffering or mortality of the animals. METHODS: A solution of busulfan, ranging from 25 µg/20 µl to 100 µg/20 µl in 50 % DMSO was used for this study. Each testis received two diagonally opposite injections of 10 µl each. Only DMSO was used as control. Germ cell depletion was checked every 15 days. GFP-expressing SSC from transgenic donor mice C57BL/6-Tg (UBC-GFP) 30Scha/J were transplanted into busulfan-treated testis. Two months after SSCT, mice were analyzed for presence of colonies of donor-derived SSC and their ability to generate offspring. RESULTS: A dose of 75 µg of busulfan resulted in reduction of testis size and depletion of the majority of Gc of testis in all mice within 15 days post injection without causing mortality or a cytotoxic effect in other organs. Two months after SSCT, colonies of donor-derived Gc-expressing GFP were observed in recipient testes. When cohabitated with females, donor-derived offspring were obtained. By our method, 71 % of transplanted males sired transgenic progeny as opposed to 5.5 % by previously described procedures. About 56 % of progeny born were transgenic by our method as opposed to 1.2 % by the previously reported methods. CONCLUSIONS: We have established an efficient method of generating a germ cell-depleted animal model by using a lower dose of busulfan, injected through two diagonally opposite sites in the testis, which allows efficient colonization of transplanted SSC resulting in a remarkably higher proportion of donor-derived offspring generation.

Correlation between laryngobronchoscopy and pepsin in the diagnosis of extra-oesophageal reflux.

OBJECTIVE: This study aimed to investigate pepsin as a marker of extra-oesophageal reflux disease by examining its presence in tracheal aspirates and correlating it with macroscopic changes on laryngobronchoscopy, along with the results of standard tests for gastro-oesophageal reflux disease and clinical features. METHODS: A retrospective review was undertaken of a cohort of 188 paediatric patients who underwent laryngobronchoscopy at a tertiary children's hospital and for whom pepsin assay results of tracheal aspirates were available. An association analysis was performed. RESULTS: The mean patient age was 3.99 (3.40-4.58) years, with a male preponderance (55 per cent). Positive changes on laryngobronchoscopy were significantly associated with positive tracheal pepsin findings (p < 0.0001) but not with positive standard gastro-oesophageal reflux disease investigations. A positive pepsin assay was significantly associated with a history of recurrent croup (p = 0.0385) and a diagnosis of cystic fibrosis (p = 0.0232). CONCLUSION: Macroscopic changes on laryngobronchoscopy were significantly associated with positive tracheal pepsin findings in this paediatric population, suggesting that extra-oesophageal reflux disease may be a contributing aetiology.

Adjunct antibiotic combination therapy for steroid-refractory or -dependent ulcerative colitis: an open-label multicentre study.

BACKGROUND: We previously demonstrated that antibiotic combination therapy is effective for induction and maintenance of ulcerative colitis (UC) remission. AIM: To assess whether antibiotic combination therapy is effective for active UC refractory to or dependent on steroids in a multicentre, open-label trial. METHODS: We enrolled 30 patients with steroid-refractory and 64 with steroid-dependent active UC. These patients received three-times-daily by mouth amoxicillin 500 mg, tetracycline 500 mg and metronidazole 250 mg, for two weeks, as well as conventional treatment. Symptom assessment and colonoscopic evaluation were performed before enrolment and at 3 and 12 months after treatment completion. Clinical response was defined as a Lichtiger symptom score decrease in ≥3 points and clinical remission as a score ≤4. RESULTS: Nineteen of the 30 steroid-refractory (63.3%) and 47 of the 64 steroid-dependent (73.4%) patients showed a clinical response within 2 weeks. At 3 and 12 months, 60% and 66.6% of steroid-refractory patients, and 56.3% and 51.6% of steroid-dependent patients, respectively, achieved clinical remission. In the steroid-dependent group, 39 of the 64 patients (60.9%) were able to stop steroid therapy and remained in remission for 3 months. Three (10%) steroid-refractory and four (6.3%) steroid-dependent patients underwent colectomy. CONCLUSIONS: This multicentre, long-term follow-up study suggests 2 week antibiotic combination therapy to be effective and safe in patients with active UC refractory to or dependent on steroids.

Abnormal fatty acid composition in the frontopolar cortex of patients with affective disorders.

Bipolar and major depressive disorders are essentially relapsing and remitting disorders of affect with nearly full recovery between episodes. Although the underlying molecular mechanisms remain unclear, myelin-related abnormalities have long been suspected. Here, using novel statistical analysis, we show that subtle but significant abnormalities exist in the composition of fatty acids (FAs), including docosapentaenoic acid (22:5n-3), one of the omega-3 polyunsaturated FAs, found in the post-mortem frontopolar cortex (FPC) of subjects with bipolar or major depressive disorders, although not in those with schizophrenia. These abnormalities were all aggravated in a myelin level-dependent manner, suggesting their close relationship with myelination. Animal studies have further revealed that chronic antidepressant treatment induces robust changes in brain FA metabolism, but contributes only part of the abnormalities found in the affective disorder brains. These findings indicate that the pathophysiology of affective disorders involves an unknown type of perturbed myelination in the FPC that may serve as a novel diagnostic and therapeutic target.

Disopyramide-induced hypoglycemia in a non-diabetic hemodialysis patient: a case report and review of the literature.

Disopyramide, an antiarrhythmic drug, has been reported to cause hypoglycemia; however, its mechanism of action remains unclear. Pre-existing factors that increase the concentration of the drug in the blood increase the risk of hypoglycemia. Furthermore, other factors can also increase the risk of hypoglycemia even when disopyramide levels are in the therapeutic range. It has been proposed that disopyramide-induced hypoglycemia is caused by stimulation of insulin secretion due to the inhibition of the pancreatic beta-cell ATP-sensitive K+ channels. We report a case of severe disopyramide-induced hypoglycemia in a nondiabetic 72-year-old woman on hemodialysis. Concentrations of counter-regulatory hormones, serum insulin, and C-peptide were measured. From these data, it appears that disopyramide-induced hypoglycemia results from sustained endogenous insulin secretion, with a concomitant inadequate counter-regulatory response. Although hypoglycemia occurs infrequently in patients treated with disopyramide, this adverse effect is clinically important and potentially life-threatening. Evidence suggests that disopyramide-induced hypoglycemia results from endogenous insulin secretion and can occur in patients with therapeutic blood concentrations of the drug. Patients at risk include those with renal impairment, advanced age, and malnutrition, and blood glucose levels should be monitored carefully in such patients.

Anterior tongue reduction surgery for paediatric macroglossia.

OBJECTIVE: Anterior tongue reduction is indicated when macroglossia causes problems with oral hygiene, airway compromise, deglutition, articulation or orthognathic complications. Causes of macroglossia include hypothyroidism, mucopolysaccharide and lipid storage disease, lymphangioma, haemangioma, neurofibroma, and muscular macroglossia. This paper presents an 11-year experience of anterior tongue reduction at Great Ormond Street Hospital. METHOD: Retrospective study of patient medical records identified from the hospital ENT database. Anterior wedge resection was the preferred technique. RESULTS: Anterior tongue reduction was performed on 18 patients, due to cystic hygroma with tongue involvement (nine patients), Beckwith-Wiedemann syndrome (eight) and Down's syndrome (one). Anterior wedge resection was preferred, using electrocautery in the majority, except for four cases involving CO2 laser. All but one patient had a good surgical outcome (i.e. tongue in mouth at rest). One patient subsequently required multiple laser procedures for recurrent macroglossia. CONCLUSION: Anterior tongue reduction can be a safe procedure, with limited post-operative morbidity, consistently resulting in good surgical outcomes and improvement in macroglossia symptoms. Speech development does not appear to be adversely affected.