Antibacterial applications of biologically synthesized Pichia pastoris silver nanoparticles

Objectives

This article highlights the biological synthesis of silver nanoparticles (AgNPs) with their characteristic analysis, and it focuses on the application of synthesized NPs against multidrug resistance (MDR) bacteria. A cytotoxicity study was performed to assess the biocompatibility.

Methods

Silver nanoparticle (AgNPs) formation was confirmed by different characterization methods such as UV-Vis spectrophotometer, Dynamic light scattering (DLS)- Zeta, Fourier transform infrared (FTIR), and Transmission electron microscope (TEM). The antimicrobial activity of the AgNPs was checked against various bacterial strains of Staphylococcus aureus (S. aureus), Escherichia coli (E. coli), Enterococcus faecalis (E. faecalis), and Klebsiella pneumonia (K. pneumonia) by disc diffusion, minimum inhibition concentration test (MIC), and kinetic studies. The cytotoxicity of NPs against the Vero cell line was studied by cytotoxic assay.

Results

The primary analysis of the formation of nanoparticles (NPs) was made by UV-Vis spectrophotometric analysis at 400 nm. At the same time, the efficient capping checked by FTIR shows the presence of a functional group at different wavelengths 3284, 1641,1573,1388,1288, and 1068 cm-1. At the same time, the transmission electron microscopic analysis (TEM) and DLS show that the shape and size of the synthesized NPs possess an average size of around ∼10-30 nm with spherical morphology. Further, the zeta potential confirmed the stability of the NPs. While the yield of NPs formation from silver salt was determined by an online yield calculator with the EDX analysis results. Synthesized NPs showed bactericidal effects against all the selected MDR pathogens with nontoxic effects against mammalian cells.

Conclusion

Our findings indicate the remarkable antimicrobial activity of the biologically synthesized AgNPs, which can be an antimicrobial agent against multi-drug-resistant bacteria.

Evaluation of Effects of Various Alpha and Beta Angulations for T-loop Made of Stainless Steel and Titanium Molybdenum Archwires during Space Closure: Finite Element Method (FEM) Study

Space closure follows the initial stage of levelling and alignment in Pre-adjusted Edgewise treatment. There are majorly two methods of space closure, Loop mechanics and Sliding mechanics. Loop mechanics or frictionless mechanics is a preferred method because of its potential to produce pre-determined moment-to-force ratios which accurately achieve controlled movement of teeth. The aim of this finite element study was to evaluate the effects of three types of retraction loops with different moment bends (alpha and beta) made of 0.016"×0.022" stainless steel and TMA archwires with Finite Element Analysis. A Finite element model of CAD geometric model of standard MBT prescription (0.018" slot), Stainless Steel and Titanium Molybdenum Alloy (TMA) wire (0.016" × 0.022") and 3 loops (T-loop, Open Vertical and Closed helical loop) were constructed. A solid model of upper jaw with all permanent maxillary teeth except 1st premolar (extraction) with surrounding periodontal ligament and alveolar bone was prepared. Force, moment to force ratio, mesio-distal crown tipping, mesio-distal root tipping and vertical root movement (extrusion) were measured for different alpha and beta bends in anterior and posterior segments respectively. Force values without moment bends was found to be highest in open vertical loop in both anterior (SS- 414gms; TMA- 255gms) and posterior region (SS-540; TMA-370gms) with both SS and TMA wires. Moment to Force ratio (M/F) at both anterior and posterior segment was found to be highest in T-loop followed by closed helical loop and least in open vertical loop. Extrusion was found to be minimal in T-loop followed by closed helical loop, was maximum in open vertical loop. T-loop showed maximal control in terms of minimal extrusion and maximum M/F ratio amongst the three loops.

Comparative Evaluation of Postoperative Pain in Primary Teeth Obturated With Zinc Oxide Eugenol versus Metapex: A Randomized Clinical Trial

The fundamental objective of pulp treatment is to preserve the integrity and health of oral tissues. Pulp necrosis or irreversible pulpitis is the key indication for performing pulpectomy in primary teeth. It can be performed as a single-visit or multi-visit procedure using suitable obturating material. Various obturating materials can be used like zinc-oxide eugenol or metapex. A controversy reflects in literature and among experts in regard to single-visit or multi-visit endodontics. Hence, the purpose of this randomized clinical trial is to assess the incidence of postoperative pain with zinc oxide eugenol and metapex as an obturating material in single-visit and multiple-visit pulpectomy. The study was conducted at M S Ramaiah Dental College and Hospital, Bangalore in one year duration from 2020 to 2021. Two groups of children, forty in each group, aged between four to eight years, were included in the study. Groups were divided to perform single-visit and multi-visit endodontics with zinc-oxide eugenol and metapex as obturating material. The sample size of 40 were considered and allocated to respective group by concealment allocation. The conventional pulpectomy procedure was carried out. The post operative pain was assessed by using the pain scale through the telephonic conversation with the patient within 24 hours of treatment. Proportions were compared using Chi-square test of significance and the "p" value of less than 0.05 indicates statistical significance. The results showed, no statistically significant difference in teeth obturated with zinc oxide eugenol and metapex in both single-visit and multi-visit pulpectomy. The comparison of zinc oxide eugenol and metapex in single-visit group and multi-visit group had a 'p' value of 0.9233 and 0.4233 respectively. There were no differences between single and multi-visit treatment protocols with respect to the incidence of post operative pain. Single visit pulpectomy can be performed with added advantages with either zinc oxide eugenol or metapex.

Bioherbicidal potential of different species of Phoma: opportunities and challenges

Modern agriculture has been facing new challenges and fostering innovations to establish sustainable plant production. An integral part of these strategies is implementing new eco-friendly technologies in plant protection for better human health and a safer environment by minimizing the use of hazardous chemicals and also encouraging innovations such as the use of bio-based strategies for weed control. This specific strategy addresses the need to reduce the use and risk of pesticides, replacing conventional chemical herbicides with new bio-based solutions. In response to these issues, biocontrol strategies are gaining increased attention from stakeholders such as farmers, seed companies, agronomists, breeders, and consumers. Among these, bioherbicides have huge potential for the management of harmful weeds without affecting the natural quality of the environment and human health. In this context, this review is devoted to present an overview of the mycoherbicidal potential of Phoma sensu lato group of fungi, examining the advances in this field, including technological and scientific challenges and outcomes achieved in recent years. The mycoherbicides are eco-friendly and economically viable. KEY POINTS: • Some Phoma species have demonstrated herbicide activity. • These species secrete secondary metabolites responsible for the control of weeds. • They can be used as non-chemical, cost-effective, and eco-friendly bioherbicides.

Practical consensus recommendations regarding the management of HER2 neu positive metastatic breast cancer

Metastatic breast cancer (MBC) is cancer that has spread from the breast to another part of the body or has come back in another distant location. Treatment options for MBC depend on several factors, including where the cancer has spread, the patient's overall health, and the levels of hormone receptors and HER2 in the tumour. Over-expression of HER2 is generally considered to be a negative prognostic feature because it accompanies an increase in breast cancer mortality. However, the development of agents that specifically target HER2 has improved the management of patients with these tumours.^{[7],[8],[9],[10]} This expert group used data from published literature, practical experience and opinion of a large group of academic oncologists to arrive at these practical consensus recommendations in regards with the use of these agents and the management of HER2 positive MBC for the benefit of community oncologists.

Practical consensus recommendations for neo-adjuvant chemotherapy in triple negative breast cancer

This manuscript provides a practical and easy to use consensus recommendation to community oncologists on how to use neoadjuvant chemotherapy in triple negative breast cancer patients.

Practical consensus recommendations for gestational breast cancer

This manuscript provides a practical and easy to use consensus recommendation to community oncologists on how to manage gestational breast cancer.

Methicillin-resistant Staphylococcus aureus: epidemiology and antimicrobial susceptibility experiences from the University Hospital 'Luigi Vanvitelli' of Naples

Methicillin-resistant Staphylococcus aureus (MRSA) is one of the important pathogens worldwide showing resistance to several widely used antibiotics. This has made the treatment of MRSA infections harder, especially due to their prevalence in the hospital setting. We evaluated the antibiotic susceptibility patterns of healthcare-associated MRSA infections with a focus on Vancomycin Intermediate S. Aureus (VISA) and macrolide-licosamide-streptogramin B (MLS_B) phenotypes. A total of 417 Staphylococcus aureus (S. aureus) cases were isolated between January 2017 and December 2018, through several clinical specimens collected from the University Hospital 'Luigi Vanvitelli' of Naples. We identified bacterial strains using Matrix-Assisted Laser Desorption/Ionization-Time of Flight (MALDI-TOF) and antimicrobial susceptibility using Phoenix BD (Becton Dickinson, NJ, USA). Out of the total 417 S. aureus cases, 140 were MRSA (33.6%) and of these, 50% were soft tissue infections. All MRSA and Methicillin sensible S.aureus MSSA isolates were susceptible to linezolid and daptomycin. Two MRSA cases exhibited intermediate resistance to vancomycin and were of constitutive MLS_B phenotype. Among the MRSA strains, 11.4% were constitutive and 43.6% were inducible MLS_B phenotypes and 8.6% were macrolide-streptogramin B phenotype. This study characterized the epidemiological status, antibiotic resistance patterns, and current prevalent phenotypes of healthcare-associated MRSA. This knowledge can aid clinicians in improving the antimicrobial stewardship program by adapting appropriate guidelines for the proper use of MRSA antibacterial agents.

Audio/visual recording of doctors in hospitals: Guideline from the Association of Anaesthetists

Guidelines are presented that summarise the legal position regarding the audio/visual recording of doctors and others in hospitals. In general, there are few, if any, legal grounds for refusing a request by patients to record procedures and/or discussions with clinicians, although some staff may feel uncomfortable being recorded. Trusts and others are advised to draw up local policies and ensure staff and patients are adequately informed.

Guidelines for safe transfer of the brain-injured patient: trauma and stroke, 2019: Guidelines from the Association of Anaesthetists and the Neuro Anaesthesia and Critical Care Society

The location of care for many brain-injured patients has changed since 2012 following the development of major trauma centres. Advances in management of ischaemic stroke have led to the urgent transfer of many more patients. The basis of care has remained largely unchanged, however, with emphasis on maintaining adequate cerebral perfusion as the key to preventing secondary injury. Organisational aspects and training for transfers are highlighted, and we have included an expanded section on paediatric transfers. We have also provided a table with suggested blood pressure parameters for the common types of brain injury but acknowledge that there is little evidence for many of our recommendations. These guidelines remain a mix of evidence-based and consensus-based statements. We have received assistance from many organisations representing clinicians who care for these patients, and we believe our views represent the best of current thinking and opinion. We encourage departments to review their own practice using our suggestions for audit and quality improvement.

Effect of weight loss on neutrophil resolvins in the metabolic syndrome

BACKGROUND

Non-resolving inflammation associates with obesity and insulin resistance, and may be dependent on the balance of inflammatory substances and specialised pro-resolving mediators of inflammation (SPM) that act to halt the inflammatory response. This controlled trial examined the effect of weight loss on neutrophil synthesis of SPM in volunteers with the metabolic syndrome (MetS).

METHODS

Volunteers with MetS (n = 42) were matched for age and gender and randomly assigned to a 12-wk weight loss program followed by 4-wk weight stabilization or a 16-wk weight maintenance program. At baseline and 16 weeks, isolated neutrophils were stimulated with calcium ionophore and the released SPM were measured by LC-MS/MS.

RESULTS

At baseline the SPM resolvin (Rv) E1, 18R-RvE3, RvD2 and Maresin-1 (MaR-1) were detected from stimulated neutrophils. The concentration of released RvE1 was at least 6-fold that of other detected SPM. Weight loss of 4.7 ± 0.8 kg, led to a 2-fold increase in RvE1, P = 0.013, relative to the weight maintenance group. The increase in RvE1 after weight loss was related to, but independent of leukotriene B_4. CONCLUSION: Following weight loss, human neutrophils from individuals with the metabolic syndrome are capable of releasing larger amounts of RvE1 upon stimulation.

Abstract P6-11-18: Ten year trends in antiemetic prescribing in cancer patients receiving highly emetogenic chemotherapy (HEC)

Purpose: Prevention of chemotherapy-induced nausea and vomiting (CINV) is essential to preserve quality of life in cancer patients receiving highly emetogenic chemotherapy (HEC) such as doxorubicin-cyclophosphamide (AC) or cisplatin. Recently, new drugs (e.g. fosaprepitant and newer neurokinin 1 receptor antagonists [NK1RAs], rolapitant and netupitant) and updated guidelines for antiemetic use (e.g. adding olanzapine) have emerged. However, trends in real world antiemetic use are understudied.

Methods: We performed a retrospective study using the OptumLabs Data Warehouse (OLDW), which includes administrative claims for privately insured and Medicare Advantage enrollees in the U.S. We identified 34,236 patients age 18 years or older treated with either AC or cisplatin between January 2006 and June 2016. Data collected included baseline demographics (age, gender, census region and race), chemotherapy administered, and presence/absence of a central intravenous access device. Trends of anti-emetic use were presented overall and separately for 5-HT receptor antagonists (5HT3RAs) and NK1RAs.

Results: 23,030 patients (67.3%) received an anthracycline-based regimen (AC with or without docetaxel or paclitaxel), and 11,206 (32.7%) patients received cisplatin. Approximately two thirds of patients were female (n= 23,392). Dexamethasone use was stable over the decade (used by 85-90% in all years). Use of 5HT3RAs, primarily palonosetron and ondansetron, occurred in at least 95% of patients in all study years, consistent with guideline recommendations. NK1RAs were underutilized early on compared with guideline recommendations, but use increased to approximately 80% in the most recently evaluated year. Fosaprepitant use rose precipitously starting in 2009, preceding a sharp fall in aprepitant use beginning in 2011. The use of olanzapine, rolapitant and netupitant was minimal throughout the study period.

Conclusions: Dexamethasone and 5-HT3RAs were used in the vast majority of patients receiving HEC, in accordance with guideline recommendations. Less compliance with guidelines was seen with NK1RA use.

Citation Format: O'Sullivan CC, Van Houten HK, Sangaralingham L, Leal AD, Shinde S, Liu H, Ettinger D, Loprinzi CL, Ruddy KJ. Ten year trends in antiemetic prescribing in cancer patients receiving highly emetogenic chemotherapy (HEC) [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P6-11-18.

AAGBI: Safer pre-hospital anaesthesia 2017: Association of Anaesthetists of Great Britain and Ireland

Pre-hospital emergency anaesthesia with oral tracheal intubation is the technique of choice for trauma patients who cannot maintain their airway or achieve adequate ventilation. It should be carried out as soon as safely possible, and performed to the same standards as in-hospital emergency anaesthesia. It should only be conducted within organisations with comprehensive clinical governance arrangements. Techniques should be straightforward, reproducible, as simple as possible and supported by the use of checklists. Monitoring and equipment should meet in-hospital anaesthesia standards. Practitioners need to be competent in the provision of in-hospital emergency anaesthesia and have supervised pre-hospital experience before carrying out pre-hospital emergency anaesthesia. Training programmes allowing the safe delivery of pre-hospital emergency anaesthesia by non-physicians do not currently exist in the UK. Where pre-hospital emergency anaesthesia skills are not available, oxygenation and ventilation should be maintained with the use of second-generation supraglottic airways in patients without airway reflexes, or basic airway manoeuvres and basic airway adjuncts in patients with intact airway reflexes.

AAGBI guidelines: the use of blood components and their alternatives 2016

Blood transfusion can be life-saving. Anaesthetists regularly request and administer blood components to their patients. All anaesthetists must be familiar with indications and appropriate use of blood and blood components and their alternatives, but close liaison with haematology specialists and their local blood sciences laboratory is encouraged. Considerable changes in approaches to optimal use of blood components, together with the use of alternative products, have become apparent over the past decade, leading to a need to update previous guidelines and adapt them for the use of anaesthetists working throughout the hospital system.

Urinary bladder inflammation induces changes in urothelial nerve growth factor and TRPV1 channels

BACKGROUND AND PURPOSE

The urinary bladder urothelium expresses various receptors and in response to chemical and mechanical stimuli releases mediators, thereby modulating bladder sensory pathways. Transient receptor potential vanilloid 1 (TRPV1) ion channels and nerve growth factor (NGF) in those cells are implicated in this modulatory effect and play a role in sensitizing pain-related afferent pathways during inflammation. In this study, we investigated the interaction between NGF and TRPV1 channels in urothelial cells.

EXPERIMENTAL APPROACH

Urothelial cells from female Sprague-Dawley rat bladders were cultured to quantify membrane expression of TRPV1 channels and capsaicin-induced ATP release in the presence of NGF alone or with TrKA or PI3K inhibitors. Pain scores from rats with cyclophosphamide (CYP)-induced bladder inflammation were assessed after treatment with a TrkA antagonist. Bladders (from control and CYP rats) were collected and analysed for NGF content and TRPV1 channel expression.

KEY RESULTS

Cultured cells responded to NGF with increased TRPV1 channel expression in the cell membrane and increased release of ATP. Both responses were blocked by either a TrkA antagonist or a PI3K inhibitor. Treatment in vivo with the TrkA antagonist alleviated pain symptoms and reduced CYP-induced NGF overexpression in the mucosa. Furthermore, in urothelial cells from animals with bladder inflammation, expression of TRPV1 channels in the membrane was significantly increased.

CONCLUSIONS AND IMPLICATIONS

During bladder inflammation, increased production of NGF in urothelial cells induced increased expression and activity of TRPV1 channels in the cell membrane. This effect was primarily mediated by the PI3K pathway.

Disease-free ovarian cancer patients report severe pain and fatigue over time: prospective quality of life assessment in a consecutive series

objective: Among ovarian cancer patients, cancer treatment is aggressive and yet survival is often so limited; hence, this study sought to measure quality of life with the ultimate goal of identifying ways of improving it over the duration of these patients' lives.

MATERIALS AND METHODS

The medical records of all ovarian cancer patients who received some/all of their initial chemotherapy at the Mayo Clinic in Rochester, Minnesota from late 2010 through 2012 were reviewed. Patient-reported quality of life was derived from the following ten-point linear analogue scale questions which had been administered to all patients: 1) How would you describe your degree of pain, on average? 2) How would you describe your level of fatigue, on average? 3) How would you describe your overall quality of life? Quality of life data were censored upon cancer recurrence.

RESULTS

Among 59 eligible patients, the median cumulative interval during which quality of life was serially assessed was 1.15 years (range: three months, 3.2 years). Area under the curve for pain, fatigue, and global quality of life showed no statistically significant differences between patients treated with dose-dense chemotherapy with carboplatin/paclitaxel (n = 10) versus three-week chemotherapy with carboplatin/paclitaxel (n = 36) versus other (n = 13). Although pain, fatigue, and global quality of life improved over time, 35 of 59 (59%) patients reported grade 4 or worse pain during follow up, and 47 of 59 (80%) reported grade 4 or worse fatigue (higher scores denote worse pain or fatigue). After completion of cancer treatment, 30 (51%) described grade 4 or worse pain or fatigue. The most common pain site was the abdomen/pelvis, followed by the back, followed by the hands, feet, fingers, and toes.

CONCLUSION

In ovarian cancer patients who remain cancer-free, severe pain and fatigue occur years after cancer treatment. Further research should focus on how best to address these symptoms.

Persons at high risk for HIV infection in Kisumu, Kenya: identifying recruitment strategies for enrolment in HIV-prevention studies

A combination of in-depth interviews ( n = 38) and surveys ( n = 203) were used to (1) identify strategies to recruit persons at high risk for HIV infection; (2) determine whether one strategy was more successful than others; and (3) describe motivators and barriers to participation in HIV-prevention studies. From in-depth interviews, four main recruitment strategies were identified: (1) use of a person with specific knowledge of a target population (link person mobilization); (2) use of co-workers or contemporaries (peer mobilization); (3) use of group or association leaders (leader mobilization); and (4) contacting persons by study staff directly (staff contact mobilization). The odds of inconsistently using condoms during sex were greater among those recruited using the peer mobilization (adjusted odds ratio [AOR] = 3.59; 95% confidence interval [CI] = 1.35–9.54) and the leader mobilization strategies (AOR = 2.76; 95% CI = 1.04–7.38) compared with the link person mobilization strategy. The main motivators for taking part in an HIV research study were receiving HIV-prevention education, HIV information or counselling, and receiving compensation for study participation. The main barriers were fear of lack of confidentiality and HIV testing concerns. Using evaluated strategies to recruit persons at high risk for HIV infection and addressing barriers to participation will improve the conduct and outcome of HIV-prevention studies.

Role of RT-PCR and FISH in diagnosis and monitoring of acute promyelocytic leukemia

BACKGROUND

Patients with a presence of Promyelocytic Leukemia-Retinoic Acid Receptor Alpha (PML-RARA) genes rearrangement predict a favorable response to all-trans retinoic acid (ATRA), and a significant improvement in survival. Therefore, establishing the presence of PML-RARA rearrangement is important for optimal patient management.

AIM

The objective of this study is to compare and assess the role of fluorescent in situ hybridization (FISH) and reverse transcriptase polymerase chain reaction (RT-PCR) in the diagnosis and long-term monitoring of Acute Promyelocytic Leukemia (APL).

MATERIALS AND METHODS

We compared 145 samples received at different interval of times to analyze the sensitivity of RT-PCR and FISH.

RESULTS

The failure rate for RT-PCR was 4% at baseline, 13% at induction, and 0% at the end of consolidation. And for FISH it was 8% at baseline, 38% at induction, and 66% at the end of consolidation. The predictive values of relapse in the patients who were positive and negative by RT-PCR, at the end of induction, were 60% and 3%, respectively, and at end of consolidation it was 67% and 4%, respectively. On the other hand the predictive values of relapse in patients who were positive and negative by FISH at end of induction were 57% and 6%, respectively; while at end of consolidation it was 14% who were negative by FISH.

CONCLUSION

Both RT-PCR and FISH are important for the diagnosis of APL cases, as both techniques complement each other in the absence or failure of any one of them. However, RT-PCR is more sensitive than FISH for the detection of minimal residual disease in the long-term monitoring of these patients. The present study shows that the predictive value of relapse is more associated with minimal residual disease (MRD) results by RT-PCR than that by FISH.