The 11th edition of Harrison's Principles of Internal Medicine welcomes Anthony Fauci to its editorial staff, in addition to more than 85 new contributors. While the organization of the book is similar to previous editions, major emphasis has been placed on disorders that affect multiple organ systems. Important advances in genetics, immunology, and oncology are emphasized. Many chapters of the book have been rewritten and describe major advances in internal medicine. Subjects that received only a paragraph or two of attention in previous editions are now covered in entire chapters. Among the chapters that have been extensively revised are the chapters on infections in the compromised host, on skin rashes in infections, on many of the viral infections, including cytomegalovirus and Epstein-Barr virus, on sexually transmitted diseases, on diabetes mellitus, on disorders of bone and mineral metabolism, and on lymphadenopathy and splenomegaly. The major revisions in these chapters and many

Harrison's Principles of Internal Medicine

Chronic hepatitis B is caused by persistent infection with the hepatitis B virus (HBV), a unique DNA virus that replicates through an RNA intermediate produced from a stable covalently closed circular DNA molecule. Viral persistence appears to be due to inadequate innate and adaptive immune responses. Chronic infection has a variable course after several decades resulting in cirrhosis in up to one‐third of patients and liver cancer in a proportion of those with cirrhosis. Sensitive assays for HBV DNA levels in serum have been developed that provide important insights into pathogenesis and natural history. Therapy of hepatitis B is evolving. Peginterferon induces long‐term remissions in disease in one‐third of patients with typical hepatitis B e antigen (HBeAg) positive chronic hepatitis B, but a lesser proportion of those without HBeAg. Several oral nucleoside analogues with activity against HBV have been shown to be effective in suppressing viral levels and improving biochemical and histological features of disease in a high proportion of patients with and without HBeAg, at least in the short term. What is uncertain is which agent or combination of agents is most effective, how long therapy should last, and which criteria should be used to start, continue, switch or stop therapy. Long‐term therapy with nucleoside analogues may be the most appropriate approach to treatment, but the expense and lack of data on long‐term safety and efficacy make recommendations difficult. Clearly, many basic and clinical research challenges remain in defining optimal means of management of chronic hepatitis B. (HEPATOLOGY 2007;45:1056–1075.)

Management of hepatitis B: Summary of a clinical research workshop Potential conflict of interest: Dr. Lok is a consultant and received grants from GlaxoSmithKline, Bristol-Myers Squibb, Idenix, Gilead, Roche, and Innogenetics.

Silver nanoparticles (AgNPs) have been one of the most attractive nanomaterials in biomedicine due to their unique physicochemical properties. In this paper, we review the state-of-the-art advances of AgNPs in the synthesis methods, medical applications and biosafety of AgNPs. The synthesis methods of AgNPs include physical, chemical and biological routes. AgNPs are mainly used for antimicrobial and anticancer therapy, and also applied in the promotion of wound repair and bone healing, or as the vaccine adjuvant, anti-diabetic agent and biosensors. This review also summarizes the biological action mechanisms of AgNPs, which mainly involve the release of silver ions (Ag+), generation of reactive oxygen species (ROS), destruction of membrane structure. Despite these therapeutic benefits, their biological safety problems such as potential toxicity on cells, tissue, and organs should be paid enough attention. Besides, we briefly introduce a new type of Ag particles smaller than AgNPs, silver Angstrom (A, 1 A = 0.1 nm) particles (AgAPs), which exhibit better biological activity and lower toxicity compared with AgNPs. Finally, we conclude the current challenges and point out the future development direction of AgNPs.

Silver nanoparticles: Synthesis, medical applications and biosafety

This review is devoted to the medical application of silver nanoparticles produced as a result of “green” synthesis using various living organisms (bacteria, fungi, plants). The proposed mechanisms of AgNPs synthesis and the action mechanisms on target cells are highlighted.

https://www.mdpi.com/2079-4983/11/4/84/pdf

Silver Nanoparticles: Mechanism of Action and Probable Bio-Application

Coronavirus disease 2019 (COVID-19) is the worst pandemic disease of the current millennium This disease is caused by the highly contagious severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which first exhibited human-to-human transmission in December 2019 and has infected millions of people within months across 213 different countries Its ability to be transmitted by asymptomatic carriers has put a massive strain on the currently available testing resources Currently, there are no clinically proven therapeutic methods that clearly inhibit the effects of this virus, and COVID-19 vaccines are still in the development phase Strategies need to be explored to expand testing capacities, to develop effective therapeutics, and to develop safe vaccines that provide lasting immunity Nanoparticles (NPs) have been widely used in many medical applications, such as biosensing, drug delivery, imaging, and antimicrobial treatment SARS-CoV-2 is an enveloped virus with particle-like characteristics and a diameter of 60–140 nm Synthetic NPs can closely mimic the virus and interact strongly with its proteins due to their morphological similarities Hence, NP-based strategies for tackling this virus have immense potential NPs have been previously found to be effective tools against many viruses, especially against those from the Coronaviridae family This Review outlines the role of NPs in diagnostics, therapeutics, and vaccination for the other two epidemic coronaviruses, the 2003 severe acute respiratory syndrome (SARS) virus and the 2012 Middle East respiratory syndrome (MERS) virus We also highlight nanomaterial-based approaches to address other coronaviruses, such as human coronaviruses (HCoVs);feline coronavirus (FCoV);avian coronavirus infectious bronchitis virus (IBV);coronavirus models, such as porcine epidemic diarrhea virus (PEDV), porcine reproductive and respiratory syndrome virus (PRRSV), and transmissible gastroenteritis virus (TGEV);and other viruses that share similarities with SARS-CoV-2 This Review combines the salient principles from previous antiviral studies with recent research conducted on SARS-CoV-2 to outline NP-based strategies that can be used to combat COVID-19 and similar pandemics in the future

Nanoparticle-Based Strategies to Combat COVID-19

The exploration of nanoscale materials for their therapeutic potential against emerging and re-emerging infections has been increased in recent years. Silver nanoparticles (AgNPs) are known to possess antimicrobial activities against different pathogens including viruses and provide an excellent opportunity to develop new antivirals. The present study focused on biological synthesis of AgNPs from Andrographis paniculata, Phyllanthus niruri, and Tinospora cordifolia and evaluation of their antiviral properties against chikungunya virus. Synthesized plants AgNPs were characterized to assess their formation, morphology, and stability. The cytotoxicity assays in Vero cells revealed that A. paniculata AgNPs were most cytotoxic with maximum non-toxic dose (MNTD) value of 31.25 μg/mL followed by P. niruri (MNTD, 125 μg/mL) and T. cordifolia AgNPs (MNTD, 250 μg/mL). In vitro antiviral assay of AgNPs based on degree of inhibition of cytopathic effect (CPE) showed that A. paniculata AgNPs were most effective, followed by T. cordifolia and P. niruri AgNPs. The results of antiviral assay were confirmed by cell viability test using 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) dye, which revealed that A. paniculata AgNPs inhibited the virus to a maximum extent. The cell viability of CHIKV-infected cells significantly increased from 25.69% to 80.76 and 66.8%, when treated with A. paniculata AgNPs at MNTD and ½MNTD, respectively. These results indicated that use of plants AgNPs as antiviral agents is feasible and could provide alternative treatment options against viral diseases which have no specific antiviral or vaccines available yet.

Green synthesis of silver nanoparticles from medicinal plants and evaluation of their antiviral potential against chikungunya virus.

Since emergence of the Nipah virus (NiV) in 1998 from Malaysia, the NiV virus has reappeared on different occasions causing severe infections in human population associated with high rate of mortality. NiV has been placed along with Hendra virus in genus Henipavirus of family Paramyxoviridae. Fruit bats (Genus Pteropus) are known to be natural host and reservoir of NiV. During the outbreaks from Malaysia and Singapore, the roles of pigs as intermediate host were confirmed. The infection transmitted from bats to pigs and subsequently from pigs to humans. Severe encephalitis was reported in NiV infection often associated with neurological disorders. First NiV outbreak in India occurred in Siliguri district of West Bengal in 2001, where direct transmission of the NiV virus from bats-to-human and human-to-human was reported in contrast to the role of pigs in the Malaysian NiV outbreak. Regular NiV outbreaks have been reported from Bangladesh since 2001 to 2015. The latest outbreak of NiV has been recorded in May, 2018 from Kerala, India which resulted in the death of 17 individuals. Due to lack of vaccines and effective antivirals, Nipah encephalitis poses a great threat to public health. Routine surveillance studies in the infected areas can be useful in detecting early signs of infection and help in containment of these outbreaks.

https://onlinelibrary.wiley.com/doi/pdf/10.1002/rmv.2010

Emerging trends of Nipah virus: A review.

Chikungunya is one of the highly infectious viral disease without vaccine and anti-viral. Aim of present study is to check the anti-chikungunya activities of Zingiber officinale (Ginger) in the animal cell culture model. The medicinal plant extract was prepared from Z. officinale rhizome. Median tissue culture infective dose (TCID50) of Chikungunya virus (CHIKV) and Maximum non-toxic dose (MNTD) of Z. officinale extract was determined in Vero cell-line on the basis of cell viability followed by MTT assay. In vitro anti-chikungunya activity was performed in Vero cell-line with MNTD and half of MNTD of Z. officinale medicinal plant extract. The anti-viral effect of Z. officinale was studied by observing the cytopathic effects and cell viability measured by MTT assay. Maximum non-toxic dose of Z. officinale plant extract was found 62.5 μg/ml. During anti-chikungunya experimentation, cell viability increased to 51.05% and 35.10%, when Vero cells were pre-treated with MNTD and half of MNTD of Z. officinale extract respectively. Similarly, in co-treatment, when MNTD, half of MNTD of Z. officinale and Median tissue culture infective dose CHIKV were inoculated simultaneously, then the viability of Vero cell-line was increases by 52.90% and 49.02% respectively. The rhizome extracts of Z. officinale have high potential to treat CHIKV. Medicinal plants and their metabolites are most important sources of antimicrobial and can be utilized for the development of new drugs. In view of the rapid expansion of CHIKV at the global level, there is an urgent need to develop newer anti-chikungunya drugs.

/pdf/anti-viral-activity-of-zingiber-officinale-ginger-4117bvexty.pdf

Anti-viral activity of Zingiber officinale (Ginger) ingredients against the Chikungunya virus.

The emerging infection of COVID-19 was initiated from Wuhan, China, have been spread to more than 210 countries around the globe including India. The clinical symptoms of COVID-19 are very similar to other respiratory viruses. The number of laboratory-confirmed cases and associated deaths are increasing regularly in various parts of the World. Seven coronaviruses (229E, NL63, OC43, HKU1, SARS, MERS and, COVID-19) can naturally infect human beings. Out of these four (229E-CoV, NL63-CoV, OC43-CoV, HKU1-CoV) are responsible for mild upper respiratory infections, while SARS-CoV, MERS-CoV, and COVID-19 are well known for their high mortality. Few mild strains of coronaviruses are circulating in India but there is no evidence of SARS and MERS outbreaks. The COVID-19 is an emerging viral infection responsible for pandemics. Fortunately, the mortality of COVID-19 is low as compared with SARS and MERS, the majority of its cases are recovered. The death toll of COVID-19 is high even after its low mortality because COVID-19 causes a pandemic while SARS-CoV and MERS-CoV cause epidemics only. COVID-19 influenced the large segments of the world population, which led to a public health emergency of international concern, putting all health organizations on high alert. COVID-19 is the first coronavirus after Spanish Flu 1918-1919, who has extremely influenced the health system, economy, and psychology of India. The present study review is on the general continent, virology, pathogenesis, global epidemiology, clinical presentation, diagnosis, treatment and control of COVID-19 with the reference to India.

/pdf/the-indian-perspective-of-covid-19-outbreak-9z1z8hd3xi.pdf

The Indian perspective of COVID-19 outbreak.

Zika virus (ZIKV) is a mosquito-borne virus that was first isolated from Zika forest, Uganda, in 1947. Since its inception, major and minor outbreaks have been documented from several parts of worl...

/pdf/zika-virus-an-emerging-challenge-to-public-health-worldwide-52ojspjv2e.pdf

Sulochana Kaushik

Papers

Green synthesis of silver nanoparticles from medicinal plants and evaluation of their antiviral potential against chikungunya virus.

Emerging trends of Nipah virus: A review.

Anti-viral activity of Zingiber officinale (Ginger) ingredients against the Chikungunya virus.

The Indian perspective of COVID-19 outbreak.

Zika virus: an emerging challenge to public health worldwide