Delpinium uncinatum mediated green synthesis of AgNPs and its antioxidant, enzyme inhibitory, cytotoxic and antimicrobial potentials

Green synthesis of nanoparticles is becoming a method of choice for biological research due to its environmentally benign outcomes, stability and ease of synthesis. In this study, silver nanoparticles (AgNPs) were synthesized using stem (S-AgNPs), root (R-AgNPs) and mixture of stem and root (RS-AgNPs) of Delphinium uncinatum. The synthesized nanoparticles were characterized by standardized techniques and evaluated for their antioxidant, enzyme inhibition, cytotoxic and antimicrobial potentials. The AgNPs exhibited efficient antioxidant activities and considerable enzyme inhibition potential against alpha amylase, acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) enzymes. S-AgNPs showed strong cytotoxicity against human hepato-cellular carcinoma cells (HepG2) and high enzyme inhibitory effect (IC50 values 27.5μg/ml for AChE and 22.60 μg/ml for BChE) compared to R-AgNPs and RS-AgNPs. RS-AgNPs showed significant inhibition of Klebsiella pneumoniae and Aspergillus flavus and exhibited higher biocompatibility (<2% hemolysis) in human red blood cells hemolytic assays. The present study showed that biologically synthesized AgNPs using the extract of various parts of D. uncinatum have strong antioxidant and cytotoxic potentials.

Influence of metallic, metallic oxide, and organic nanoparticles on plant physiology

Nanotechnology is a research area that has experienced tremendous development given the enormous potential of nanoparticles (NPs) to influence almost all industries and conventional processes. NPs have been extensively used in agriculture to improve plant physiology, production, and nutritional values of plant-based products. The large surface area and small size are some of the desired attributes for NPs that can substantially ameliorate plants' physiological processes, thereby improving crop production. Nevertheless, the results derived from such research have not always been positive as NPs have been shown, in some cases, to negatively affect plants due to their potentially toxic nature. These toxic effects depend upon the size, concentration, nature, zeta potential, and shape of nanoparticles, as well as the used plant species. The most common response of plants under NPs toxicity is the activation of antioxidant systems and the production of secondary metabolites. The mitigation of such NPs-induced stress highly varies depending on the amount of NPs applied to the plant growth stage and the environmental conditions. On the contrary, higher photosynthetic rates, higher chlorophyll, and proline content, improved homeostasis, hormonal balance, and nutrient assimilation are the favorable physiological changes after NPs applications. Alternatively, NPs do not always exhibit positive or negative impacts on plants, and no physiological influences are sometimes observed. Considering such diversity of responses after the use of NPs on plants, this review summarizes the progress made in nanotechnology on the influence of different NPs in plant physiology through the use of indexes like seed germination, root and shoot morphology, photosynthesis, and their impact when used as carriers of cell signaling molecules such as nitric oxide (NO). Understanding the intimate dynamics of nanoparticle toxicity in plants can prove to be fruitful for the development of areas like agronomy, horticulture, plant pathology, plant physiology, etc. That, in return, can assist to ensure agricultural sustainability. Similarly, this may also help to pave the way to combat the drastic climate change and satisfy growing food demands for the ever-increasing world population. Further studies on molecular and genetic levels can certainly broaden the current understanding of NPs-plant interactions and devise the respective mitigation strategies for environmental safety.

Selective Neck Dissection for Node-Positive Oral Cavity Squamous Cell Carcinoma: A Retrospective Cohort Study

Introduction  Selective neck dissection in clinically node-negative neck is considered the standard of care for oral squamous cell carcinomas (SCCs). Controversy still prevails in node-positive disease regarding the extent of neck dissection. In our part of the world, comprehensive neck dissection is mostly considered to be the minimal optimal treatment for palpable neck disease.

Objective  To compare regional control and disease-specific survival between clinically node-positive and node-negative patients undergoing selective neck dissection for oral SCC.

Methods  This was a retrospective cohort study conducted in the department of ENT, Head and Neck surgery at a tertiary care hospital. All patients with biopsy-proven oral and lip SCC, with or without nodal disease, who underwent selective neck dissection between April 2006 and July 2015 were included in the study.

Results  During the study period, 111 patients with oral SCC underwent selective neck dissection, of whom 71 (62%) were clinically node-negative and 40 (38%) patients had clinically positive nodes in the neck. The mean follow-up was 16.62 months (standard deviation [SD]: 17.03). The overall regional control rates were 95 versus 96% for clinical negative versus positive nodes, respectively ( p  = 0.589). The disease-specific survival was 84.5% in the node negative group versus 82.5% in the node-positive group ( p  = 0.703).

Conclusion  Selective neck dissection in node-positive neck oral SCC has similar regional control rates when compared with node-negative neck SCC. The difference in disease-specific survival between the two groups is also not significant.

A Review of Microbial Mediated Iron Nanoparticles (IONPs) and Its Biomedical Applications

Nanotechnology is a booming avenue in science and has a multitude of applications in health, agriculture, and industry. It exploits materials’ size at nanoscale (1–100 nm) known as nanoparticles (NPs). These nanoscale constituents are made via chemical, physical, and biological methods; however, the biological approach offers multiple benefits over the other counterparts. This method utilizes various biological resources for synthesis (microbes, plants, and others), which act as a reducing and capping agent. Among these sources, microbes provide an excellent platform for synthesis and have been recently exploited in the synthesis of various metallic NPs, in particular iron. Owing to their biocompatible nature, superparamagnetic properties, small size efficient, permeability, and absorption, they have become an integral part of biomedical research. This review focuses on microbial synthesis of iron oxide nanoparticles using various species of bacteria, fungi, and yeast. Possible applications and challenges that need to be addressed have also been discussed in the review; in particular, their antimicrobial and anticancer potentials are discussed in detail along with possible mechanisms. Moreover, some other possible biomedical applications are also highlighted. Although iron oxide nanoparticles have revolutionized biomedical research, issues such as cytotoxicity and biodegradability are still a major bottleneck in the commercialization of these nanoparticle-based products. Addressing these issues should be the topmost priority so that the biomedical industry can reap maximum benefit from iron oxide nanoparticle-based products.

Impact of Covid19 Lockdown on Glycemic Control

Evidence shows that people with poor glycemic control are at greater risk of mortality due to Covid19. It is important to achieve and maintain good glycemic control to prevent negative outcomes during this pandemic (1). To study the effect of lockdown on glucose control we conducted an observational, retrospective cohort study involving 98 patients followed at endocrine clinic at an inner city, community hospital in Brooklyn, NY in the period February to May 2020. Of the cohort, 60% were women, mean age was 54.1 + 15.3 years, 70% was Hispanic, 24% was African American with a predominance of type 2 diabetes (86%). Mean HbA1c of prelockdown and lockdown phase was 9.77 ± 2.26% and 9.49 ± 2.17 % respectively and the difference was statistically significant (p &lt; 0.001) both in patients with Type 1 and Type 2 diabetes. Mean BMI of prelockdown and lockdown phase was 30.5 ± 6.8% and 30.1 ± 6.05% respectively and the difference was not statistically significant (p = 0.33). Despite no significant change in BMI, the factors responsible for improvement in HbA1c might be a result of refined eating patterns (increased consumption of homemade food), increased adherence to medication and time to cope with the daily challenges of diabetes management (1). Reference: Maddaloni E, Coraggio L, Pieralice S, Carlone A, Pozzilli P, Buzzetti R. Effects of COVID-19 Lockdown on Glucose Control: Continuous Glucose Monitoring Data From People With Diabetes on Intensive Insulin Therapy. Diabetes Care Aug 2020, 43 (8) e86-e87; DOI: 10.2337/dc20-0954

Middle Cranial Fossa Approach: The Incudomalleolar Joint as a Reliable Landmark

Introduction  The middle cranial fossa approach is performed by fewer neurotologists owing to a reduced number of indications. Consistent landmarks are mandatory to guide the surgeon in a narrow field.

Objectives  We have evaluated the incus and malleus head and the incudomalleal joint (IMJ) as a key landmark for identifying the superior semicircular canal (SSC) and to get oriented along the floor of the middle cranial fossa.

Methods  A combination of 20 temporal bone dissections and CT imaging were utilized to test and describe these landmarks.

Results  The blue line of the SSC is consistently identified along the prolongation of a virtual line through the IMJ and the angulation toward the root of zygoma. The mean distance from the zygoma toward the IMJ ranged from 1.60 to 1.90cm. Once the IMJ was identified, the blue line of the SSC was consistently found along the virtual line through the IMJ within 5 to 9mm.

Conclusions  The IMJ is a safe and consistent anatomical marker in the surgical approach to the middle cranial fossa floor. Opening the tegmen 1.5 to 2cm medial to the root of the zygoma and identifying the joint allows to trace a virtual line toward the SSC within 5 to 9mm. Knowledge of the close relationship between the direction of the IMJ and the superior canal can be used in all transtemporal approaches, thus orienting the surgeon in a rather narrow field with limited retraction of the dura and brain.

A Comparative Evaluation of the Antiproliferative Activity against HepG2 Liver Carcinoma Cells of Plant-Derived Silver Nanoparticles from Basil Extracts with Contrasting Anthocyanin Contents

Nanotechnology is a well-established and revolutionized field with diverse therapeutic properties. Several methods have been employed using different reducing agents to synthesize silver nanoparticles (AgNPs). Chemical mediated synthetic methods are toxic and resulted in non-desired effects on biological systems. Herein, we, synthesized silver nanoparticles using callus extract of purple basil (BC-AgNPs) and anthocyanin extract deriving from the same plant (i.e. purple basil) (AE-AgNPs), and systematically investigated their antiproliferative potential against HepG2 Liver Carcinoma Cells. The phyto-fabricated AgNPs were characterized by different techniques like UV-visible spectroscopy (UV-Vis), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), Scanning electron microscopy (SEM) and Energy dispersive X-rays (EDX). Morphologically, both types of NPs were found spherical. The average size of BC-AgNPs and AE-AgNPs as revealed through XRD and SEM analyses were calculated as 50.97 ± 0.10 nm and 42.73 ± 1.24 nm, respectively. FT-IR spectral analysis demonstrates the existence of possible phytochemicals required for the capping and reduction of Ag ions. Herein, following solid phase extraction (SPE) coupled to HPLC analysis, we report for the first-time the anthocyanin mediated synthesis of AgNPs and conforming the successful capping of anthocyanin. Small sized AE-AgNPs showed significant cytotoxic effect against human hepatocellular carcinoma (HepG2) cell line as compared to BC-AgNPs. Therefore, the results revealed that the prevalent group of flavonoids present in purple basil is the anthocyanins and AE-AgNPs could be employed as potential anticancer agents in future treatments strategies.

Comparative antileishmanial efficacy of the biosynthesised ZnO NPs from genus Verbena

This study describes ZnO NPs biosynthesis using leaf extracts of Verbena officinalis and Verbena tenuisecta. The extracts serve as natural reducing, capping and stabilization facilitators. Plant extracts phytochemical analysis, revealed that V. officinalis showed higher total phenolic and flavonoid content (22.12 and 6.38 mg g -1 DW) as compared to V. tennuisecta (12.18 and 2.7 mg g -1 DW). ZnO NPs were characterised by ultraviolet-visible spectroscopy, Fourier transform infrared, X-ray diffraction, scanning electron microscope, transmission electron microscopy (TEM) and energy dispersive X-ray. TEM analysis of ZnO NPs reveals rod and flower shapes and were in the range of 65-75 and 14-31 nm, for V. tenuisecta and V. officinalis, respectively. Bio-potential of ZnO NPs was examined through their leishmanicidal potential against Leishmania tropica. ZnO NPs showed potent leishmanicidal activity with 250 µg ml-1 being the most potent concentration. V. officinalis mediated ZnO NPs showed more potent leishmanicidal activity compared to V. tenuisecta mediated ZnO NPs due to their smaller size and increased phenolics doped onto its surface. These results can be a step forward towards the development of novel compounds that can efficiently replace the current medication schemes for leishmaniasis treatment.

Exploiting in vitro potential and characterization of surface modified Zinc oxide nanoparticles of Isodon rugosus extract: Their clinical potential towards HepG2 cell line and human pathogenic bacteria

Little is known about biogenically synthesized Zinc oxide nanoparticles (ZnONPs) from Isodon rugosus. Synthesis of metal oxide NPs from essential oil producing medicinal plants results in less harmful side effects to the human population as compared to chemically synthesized NPs. In this article, we report biogenic synthesis of ZnONPs from in vitro derived plantlets and thidiazuron (TDZ) induced callus culture of Isodon rugosus. Synthesized NPs were characterized using UV-spectra, XRD, FTIR, SEM and EDX. Furthermore, the NPs were evaluated for their potential cytotoxic (against HepG2 cell line) and antimicrobial (against drug resistant Staphylococcus epidermidis, Bacillus subtilis, Klebsiella pneumoniae and Pseudomonas aeruginosa) activities. Pure crystalline ZnONPs with hexagonal and triangular shapes were obtained as a result of callus extract (CE) and whole plant extract (WPE), respectively. ZnONPs showed potent cytotoxic and antimicrobial potential. The antimicrobial and cytotoxic activities of ZnONPs were found to be shape and surface bound phytochemicals dependent. CE mediated hexagonal ZnONPs showed superior anti-cancer and antimicrobial activities as compared to WPE mediated triangular shaped ZnONPs. It is concluded that biogenic ZnONPs have incredible potential as theranostic agents and can be adopted as useful drug delivery system in next generation treatment strategies.

Melatonin-stimulated biosynthesis of anti-microbial ZnONPs by enhancing bio-reductive prospective in callus cultures of Catharanthus roseus var. Alba

Melatonin as plant growth regulator induces differential effects on metabolites that are responsible for reduction, capping and stabilization of zinc oxide nanoparticles. Phytochemical analysis of callus cultures was performed and results were compared with callus cultures supplemented with other plant growth regulators (α-napthalene acetic acid, 2,4-dichlorophenoxy acetic acid and thidiazuron). Highest total phenolic and flavonoid content [42.23 mg of gallic acid equivalent (GAE) g^-1 DW and 36.4 mg of (quercetin equivalent) g^-1 DW, respectively] were recorded at melatonin (1.0 µM) + NAA (13.5 µM). ZnONPs were synthesized from NAA (13.5 µM) and melatonin (1.0 µM) + NAA (13.5 µM)-induced calli extracts separately and characterized via X-ray diffraction, Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). FTIR analysis confirmed the presence of phenolics and flavonoids that were mainly found responsible for reduction and capping of ZnONPs. SEM analysis showed triangular shaped ZnONPs synthesized from melatonin + NAA callus extract and these NPs were more dispersed as compared to the spherical-agglomerates of ZnONPs synthesized from NAA-mediated callus extract. Melatonin + NAA callus extract-mediated ZnONPs (having smaller size) were more potent against multiple drug resistant bacterial strains, e.g. Bacillus subtilis, Escherichia coli and Pseudomonas aeruginosa by producing zone of inhibitions 17 ± 0.76 mm,10 ± 0.57 mm and 13 ± 0.54 mm, respectively.

Biogenic synthesis of Au, Ag and Au–Ag alloy nanoparticles using Cannabis sativa leaf extract

Biogenic synthesis of gold (Au), silver (Ag) and bimetallic alloy Au–Ag nanoparticles (NPs) from aqueous solutions using Cannabis sativa as reducing and stabilising agent has been presented in this report. Formation of NPs was monitored using UV–visible spectroscopy. Morphology of the synthesised metallic and bimetallic NPs was investigated using X‐ray diffraction and scanning electron microscopy. Elemental composition and the surface chemical state of NPs were confirmed by energy dispersive X‐ray spectroscopy analysis. Fourier transform‐infrared spectroscopy was utilised to identify the possible biomolecules responsible for the reduction and stabilisation of the NPs. Biological applicability of biosynthesised NPs was tested against five bacterial strains namely Klebsiella pneumonia , Bacillus subtilis (B. subtilis ), Escherichia coli , Staphylococcus aureus and Pseudomonas aeruginosa (P. aeruginosa ) and Leishmania major promastigotes. The results showed considerable antibacterial and anti‐leishmanial activity. The Au–Ag bimetallic NPs showed improved antibacterial activity against B. subtilis and P. aeruginosa as compared to Au and Ag alone, while maximum anti‐leishmanial activity was observed at 250 μg ml−1 NP concentration. These results suggest that biosynthesised NPs can be used as potent antibiotic and anti‐leishmanial agents.

Central Nervous System and Head and Neck Histiocytoses: A Comprehensive Review on the Spectrum of Imaging Findings

The histiocytoses are a rare group of varied but related disorders characterized by abnormal tissue proliferation of macrophages and dendritic cells within tissues. The purpose of this article was to review the imaging findings in patients presenting with CNS and with head and neck manifestations of these disorders. Histiocytoses include but are not limited to Rosai-Dorfman disease, Erdheim Chester disease, Langerhans cell histiocytosis, histiocytic sarcoma, and juvenile xanthogranuloma. A review of the literature was performed to determine the sites of disease involvement. This article includes the demographics, histopathologic criteria for diagnosis, and imaging features of these histiocytoses, and describes the manifestations in locations known to harbor disease: intraaxial and extra-axial intracranial regions, the calvaria, skull base, hypothalamopituitary axis, orbits, paranasal sinuses, spine, and the head and neck region. Histiocytoses have variable imaging appearances in the CNS and in the head and neck region, and radiologists should be aware of the spectrum of findings to avoid mistaking them for other disease processes.

Learning Objective

To understand the general pathophysiology, clinical presentation, and typical imaging characteristics of the most common histiocytoses; comprehend the morphologic and immunohistochemical characteristics of these histiocytoses and the hallmark findings on pathology; and be able to differentiate between these disorders based on their most common presentations.

Use of smoke-less tobacco amongst the staff of tertiary care hospitals in the largest city of Pakistan

BACKGROUND

Use of smoke-less tobacco (SLT) is very common in South and South-East Asian countries. It is significantly associated with various types of cancers. The objectives of this study were to assess the proportion of hospital staff that use SLT, and to identify the factors associated with its use and their practices.

METHODS

In a cross-sectional study, 560 staff of two tertiary care hospitals were interviewed in the year 2009. Nurses, ward boys and technicians were counted as a paramedic staff while drivers, peons, security guards and housekeeping staff were labeled as non-paramedic staff. SLT use was considered as usage of any of the following: betel quid (paan) with or without tobacco, betel nuts with or without tobacco (gutkha) and snuff (naswar).

RESULTS

About half (48.6%) of the hospital staff were using at least one type of SLT. Factors found to be statistically significant with SLT were being a male (OR=2.5; 95% CI=1.8-3.7); having no/fewer years of education (OR=1.7; 95% CI=1.2-2.4) and working as non-paramedic staff (OR=2.6; 95% CI=1.8-3.8). Majority of SLT users were using it on regular basis, for >5 years and keeping the tobacco products in the oral cavity for >30 minutes. About half of the users started due to peer pressure and had tried to quit this habit but failed.

CONCLUSION

In this study, about half of the study participants were using SLT in different forms. We suggest educational and behavioral interventions for control of SLT usage.