Saturday, May 30, 2020

The Impact of Photo-Induced Molecular Changes of Dairy Proteins on Their ACE-inhibitory Peptides and Activity

Barbara KerkaertFrédéric MestdaghTatiana CucuKshitij ShresthaJohn Van CampBruno De Meulenaer

NutriFOODchem unit, partner in Food2Know, Department of Food Safety and Food Quality, Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, 9000 Ghent, Belgium.

Abstract

Among all dietary proteins, dairy proteins are the most important source of bio-active peptides which can, however, be affected by modifications upon processing and storage. Since it is still unknown to which extent the biological activity of dairy proteins is altered by chemical reactions, this study focuses on the effect of photo-induced molecular changes on the angiotensin I converting enzyme (ACE) inhibitory activity. Milk proteins were dissolved in phosphate buffer containing riboflavin and stored under light at 4 °C for one month during which the molecular changes and the ACE-inhibitory activity were analysed. An increase in the total protein carbonyls and the N-formylkynurenine content was observed, besides a decrease in the free thiol, tryptophan, tyrosine and histidine content. These changes were more severe in caseins compared with whey proteins and resulted moreover in the aggregation of caseins. Due to these photo-induced molecular changes, a significant loss of the ACE-inhibitory activity was observed for casein peptides. A peptide analysis moreover illustrated that the decreased activity was not attributed to a reduced digestibility but to losses of specific ACE-inhibitory peptides. The observed molecular changes, more specifically the degradation of specific amino acids and the casein aggregation, could be assigned as the cause of the altered peptide pattern and as such of the loss in ACE-inhibitory activity.
Amino Acids2012 Aug;43(2):951-62. doi: 10.1007/s00726-011-1157-y.Epub 2011 Nov 25.

Link to Publication
https://link.springer.com/article/10.1007%2Fs00726-011-1157-y

SDS Page


COVID-19 control strategies: Part 3

covid19
This is continuation of the previous post related to the COVID-19 control strategies around the world.
Please read the Part 1 and Part 2 of the series.
For the comparison of COVID-19 cases and testing coverage, please follow this link.

In this post, we will compare the COVID-19 testing and contact tracing policy  around the world and will try to see where Nepal stands.


A. Comparison of testing policy around the world


This chart shows the government policies on testing for COVID-19. It includes PCR testing only and does not include non-PCR, antibody testing methods.

Countries have been grouped into four categories: 
  • No testing policy
  • Testing only for those who both (a) have symptoms AND (b) meet specific criteria (e.g. key workers, admitted to hospital, came into contact with a known case, returned from overseas)
  • Testing of anyone showing COVID-19 symptoms
  • Open public testing (e.g “drive through” testing available to asymptomatic people)

Nepal is mainly testing symptomatic and key groups only.

B. Comparison of contact tracing policy around the world

COVID-19 control strategies: Part 2

This is continuation of the previous post related to the control strategies around the world. Please read the Part 1 of the series. 
covid19

The second most applied strategy around the world is restriction on public events and gatherings. Let's compare the application of this strategy around the world.

A) CANCELLATION OF PUBLIC EVENTS



B) RESTRICTIONS ON PUBLIC GATHERINGS

Friday, May 29, 2020

COVID-19 control strategies: Part 1

covid19
Currently, Nepal government is adopting lockdown approach to control COVID-19 pandemic. Many people are supporting this approach. However, there are increasing number of people against this approach and are demanding for alternative options. Some people even believe the conspiracy theory about COVID-19.
Everyone has the right to make their own opinion.
Let's try to compile the different control strategies adopted around the world.
We can then evaluate where Nepal stands compared to other countries around the world. 

A) SCHOOL CLOSURE STRATEGY AROUND THE WORLD

B) WORKPLACES CLOSURE STRATEGY AROUND THE WORLD

COVID-19 Cases vs Testing Coverage

covid19 Let's check out where Nepal stands in COVID-19 cases and the testing coverage.
  


Sunday, May 10, 2020

Microbial Risk Assessment: Salmonella in Chicken

This is a reconstruction of paper from Oscar 2004. He used @Risk software to carry out the risk assessment. I am reconstructing his paper using R- software taking the same model input values. So for details, please refer to the paper of Oscar 2004. The following are the important model parameters described in that paper.

Model design
The following 5 nodes were considered during model development.

Node 1- Retail
"The incidence of Salmonella contamination of whole chickens ranged from 0% to 100% with a median value of 30%. The MPN of Salmonella on contaminated whole chickens is low, often below 10 MPN, whereas the maximum MPN per chicken ranges from >300 to >1100. A minimum value of 1 MPN (by definition, the minimum level of contamination that is possible), a median value of 10 MPN, and a maximum value of 450 MPN per chicken were used to define the input settings for the PERT distribution for the extent of Salmonella contamination of ready-to-cook whole chickens at retail."


Friday, May 8, 2020

SIRD Model: COVID-19 In Pakistan

The SIRD model (as per wikipedia)


The Susceptible-Infectious-Recovered-Deceased-Model differentiates between Recovered (meaning specifically individuals having survived the disease and now immune) and Deceased. This model uses the following system of differential equations:


where  are the rates of infection, recovery, and mortality, respectively.

Monday, May 4, 2020

Dietary Supplement Regulation around the world: Part 2

This is a continuation of the previous post on DietarySupplement Regulation around the world-part1.  

supplement
If you have not read that part, please have a look at that first, before reading this second part. I have only tried to add some conceptual clarification in this second post.
Let’s start with different regulatory approach applied for food supplement by different countries.

1. Registration Vs Notification vs Pre-market approval approach

For the most countries worldwide, Nutraceuticals, Dietary supplement, Food supplements are regulated as a category of food. In some regions or countries, there are a specific set of regulations governing supplements (e.g. EU, US, ASEAN, India) under the food-based regulatory paradigm. Most of these countries have some form of a notification or registration based system, which is required to be fulfilled to bring a new product in the market. This is in contrast to the premarket approval approach required for drugs. This is due to the fact that food supplements appropriately fits in the food category and they pose very low safety risks compared to drugs.

Microbial Risk Assessment: Salmonella in Peanut butter: graphs

Have you already read the first part titled:

If you have not read that part, first you should read that part before looking at these graphs. This is graphical output of that microbial risk assessment using Monte Carlo simulation.


risk assessment graph

Microbial Risk Assessment: Salmonella in Peanut butter

Do you know the case of salmonella outbreak from peanut butter in America?

Background:
In 2008/2009, 9 people died and at least 714 people (half of them children) fell ill, all from food poisoning after eating products containing salmonella contaminated peanuts. It triggered the most extensive food recall in US involving 46 states, more than 360 companies, and more than 3,900 different products manufactured using Peanut Corporation of America (PCA) ingredients. In September 2015, Stewart Parnell was sentenced to 28 years in prison for his role in the nationwide outbreak.( for details check Wikipedia)

Microbial Risk Assessment
Let’s carry out microbial risk assessment of salmonella from peanut butter. The assumption of this case study is taken from the paper of Chen 2013.
The salmonella is not very common in peanut. Based on the historical data, the initial prevalence of salmonella in peanut during manufacturing is estimated to be 5.5 x 10-6 (i.e. 55 units out of 107 units could be contaminated with salmonella).

Sunday, May 3, 2020

COVID-19 Modelling Indian data (Part 2)


COVID-19 infection in India: SIR simulation and Prediction (Part 2)

I hope that you liked the first part. If you have not read the first part, you should read that before reading this post. 
So, we have already completed modelling and prediction for stage 2. It was interesting to note that we could not see much difference in the model at stage 2 compared to stage 1. If lock-down worked, we would expect to see some of its impact in stage 3.

let's start with stage 3


3) Stage3: third and fourth weeks after lock-down
# April 08 to April 22
start_date <- "2020-04-08"
end_date <- "2020-04-22"

After modelling, there was a clear impact of lock-down at this stage. The R0 value dropped down to around 1. (details not shown). Let's only look at the graph first.




The prediction plot below now clearly shows the flattening of the infection curve. This is the effect of lock-down. To make clearly visible, the graph is also given in logarithmic scale. The model still predicts that 10,000,000 people will be infected during the peak time, if further improvements does not occur.



Now, the current stage 4,
4) Stage4: fifth and sixth weeks after lockdown
# April 21 to May 01
start_date <- "2020-04-21"
end_date <- "2020-05-01"

The effect of lock-down remains and the value of R0 drops to around 1.


The prediction plot below now clearly shows the flattening of the infection curve. Lock-down continues to keep the impact. To make it clearly visible, the graph is also given in logarithmic scale. The model still predicts that around 1,000,000 people will be infected during the peak time, if a further improvement does not occur. This prediction is 10 times lower than the prediction based on data from previous weeks (stage 3). Since lock-down continues further for two weeks, the peak number is likely to be flattened more. Hence, less than 100,000 people are likely to be infected at the peak, if lock-down continues.

The continuation of Lock-down will help to flatten the curve further. Please note that, even though the number of infection looks high, only small portion of population is likely to be serious. So government should plan lock-down in such a way that the fraction of population likely to be serious during the peak period is within the countries healthcare capacity to handle such condition.

Please note that this is mathematical simulation and prediction based on model. It is aimed to give guidance for the policy makers for planning purpose only. General public should not be afraid of these hypothetical scenarios, as government would hopefully take better measures to keep the condition under control (like they are doing at the current situation).


Let’s all support the Lock-down. I can also make prediction on how worse it can be if lock-down will be removed. But, I don’t want to make that public already. 
Please provide feedback, suggestions and relevant comments. If anybody wants to get code to do such modeling and simulation, contact me.

COVID-19 Modelling Indian data (Part 1)

SIR Modelling and Prediction of COVID-19 infection in India (Part 1)

Kshitij Shrestha


The objective of this post is to share with you the modeling of COVID-19 infection using real data of India till today. I am using R-software to do all the modeling. The source code has not been displayed here, as most of you will have difficulty understanding that code. If you are really interested, contact me, I can share with you that one.

The modeling is done using SIR (susceptible , infected , recovered ) model.  For more information about such model please read the following links: Link to Wikipedia Link to MAA information page. There are much more information in the website.

I am going to use real data of COVID-19 infection from India. I will do the modelling and would like to evaluate the impact of lock-down on the flattening of the curve. The first confirmed case in India started in January 30, 2020. The confirmed case remained less than 5 in number, till march 03, 2020.  On a single day 23 confirmed cases were found on march 04, 2020. Afterwards, the number of infection increased exponentially. The government announced lock-down on march 25 and is still continuing it till date.

I have decided to do modeling in 4 stages.

Stage 1: exponential growth stage before starting lock-down (from march 04 to march 25)
Stage 2: first two weeks after lock down
Stage 3: third and fourth weeks after lock down
Stage 4: fifth and sixth weeks after lock-down

For each stage, the data has been used to do SIR modeling to estimate beta, gamma and R0 parameter.  The beta parameter is indication of rate of infection and gamma parameter is indication of rate of recovery and R0 is reproduction number. Please read relevant literature for more details about them.
After modeling in each stage, I have used model parameter to estimate around 200 days future prediction. That shows the scenarios likely to be if the situation would have been constant ( model parameters remaining constant). 

Lets start with first stage:

1. Stage1: Before Lock-down started
# March 04 to March 25 (before starting the lock-down) 
# before that date, situation was stable with less than 5 confirmed cases
# on march 04, 23 confirmed cases were found and the growth afterwards was exponential
Prediction with such situation without lock-down is shown below. It shows that more than 70 % population could have been infected at the peak point, which is likely to reach in August/September. The second graph is presented in logarithmic scale for better viewing. The predicted scenarios without lock-down is really scary.

2) Stage2: first two weeks after lock-down
# March 26 to April 08
start_date <- "2020-03-26"
end_date <- "2020-04-08"
 
The lock-down was started on march 25, 2020. 
The growth of confirmed cases continues to be exponential. The observation below is very similar to the one we observed during stage 1. Majority of this infection probably occurred before lock-down. It was confirmed only in this week due to the incubation period of the virus infection. 




The data does not indicate any impact of  lock-down yet. The prediction still looks scary.
The modelling and prediction for stage 3 and stage 4 will be provided in the next post. We have not seen any impact of lock-down till stage 2. 
Do you expect to see impact in stage 3 and 4. Give your comments. Please provide feedback for improvements. Follow me to read stage 3 and 4. 
Coming soon...........


Dietary Supplement Regulation around the world : Part 1

dietary supplement
For most countries worldwide, Conventional Foods, Functional Foods, Dietary Supplements, Nutraceuticals are regulated as a category of Food. Some form of registration or notification approach has been established in different countries.
Regulators mainly rely on established formal “positive” and/or “negative” ingredient lists during evaluation. 

A Novel Nutraceutical molecule : Canolol

Canolol is a novel Nutraceutical molecule isolated from roasted Rapeseed oil. It was isolated from roasted Mustard seed oil by Kshitij Shrestha
(Link to publication). You can Download original article.
It is also known as:
4-vinyl-2,6-dimethoxyphenol

4-vinylsyringol
2,6-dimethoxy-4-vinylphenol
CAS Number 28343-22-8

For general information, Link to wikipedia, Link to chemspider, Link to Pubchem

Some important Nutraceutical properties are:

COVID-19 & Food Safety Guidance

There is now an urgent requirement for the industry to ensure compliance with measures to protect food workers from contracting COVID-19, to prevent exposure to or transmission of the virus, and to strengthen food hygiene and sanitation practices.

The following WHO guideline is to highlight these additional measures so that the integrity of the food chain is maintained, and that adequate and safe food supplies are available for consumers.

Food Industry Guideline for Reducing Workforce Impacts related to COVID-19

Food businesses are encouraged to consider what contingencies can be put in place to reduce workforce impacts caused by COVID-19. The following resource can assist food businesses:

Covid-19: European officials warn that exiting lockdown will be “very long” and will require cooperation

European Union officials have unveiled their “roadmap” to phase out the ongoing coronavirus containment measures. But they warned of a “very long” exit from a crisis that has been a devastating double whammy to the continent’s health and economic wellbeing.


The European Commission president, Ursula von der Leyen, warned that a failure by countries to work together on their exit strategies could lead to a dangerous second wave of covid-19. “If shops are open on one side of the border, we don’t want people moving from one member state to the next to use the shopping opportunity,” she said, urging authorities in EU member states not to erase the progress made from the painful lockdowns imposed over the past month.
Over 80 000 people have died in Europe from covid-19, about two thirds of the global death toll, but some EU countries have already started easing their lockdowns by allowing some school classes and businesses to reopen. Von der Leyen said that EU countries should use a “gradual, tailormade approach” to lifting lockdown restrictions.
“The way back to normality will be very long,” the commission’s roadmap says, warning that masks, gloves, tests, and applications to track people’s movements will become routine—and that a full economic recovery will probably have to wait until a vaccine is found.

BMJ 2020; 369 doi: https://doi.org/10.1136/bmj.m1549

Food safety issues related to wildlife have not been taken seriously from SARS to COVID-19

Guangyue Weim, Xidian University, 266 Xinglong Section of Xifeng Road, Xi’an, Shaanxi, 710126, China

Abstract

17 years after the outbreak of SARS, the 2019-nCoV broke out in December 2019. It’s an unprecedented huge challenge and disaster for people all over the world. According to Web of Science database, The author found that 95,724 virology papers have been published in the past 17 years, 68,632 of which are supported by fund (71.7%). Meanwhile, 50,567 papers related to food safety have been published in the past 17 years, 28,165 of which are supported by fund (55.7%%). It seems that people’s safety and global stability are greatly guaranteed. However, whether SARS or 2019-nCoV, scientists were targeting wildlife, the author found that only 515 studies on food safety related to wildlife have been published worldwide in the past 17 years. After SARS, the whole world did not pay enough attention to food safety related to wildlife. 
https://doi.org/10.1016/j.envres.2020.109605

Food Safety and COVID-19

Coronaviruses are generally thought to be spread from person-to-person through respiratory droplets. Currently there is no evidence to support transmission of COVID-19 associated with food. Before preparing or eating food, it is important to always wash your hands with soap and water for 20 seconds for general food safety. Throughout the day, wash your hands after blowing your nose, coughing or sneezing, or going to the bathroom.
It may be possible that a person can get COVID-19 by touching a surface or object that has the virus on it and then touching their own mouth, nose, or possibly their eyes, but this is not thought to be the main way the virus spreads.
In general, because of poor survivability of these coronaviruses on surfaces, there is likely very low risk of spread from food products or packaging that are shipped over a period of days or weeks at ambient, refrigerated, or frozen temperatures.
You should always handle and prepare food safely, including keeping raw meat separate from other foods, refrigerating perishable foods, and cooking meat to the right temperature to kill harmful germs. See CDC’s Food Safety site for more information. 

COVID-19 infection: the perspectives on immune responses

Yufang Shi, Ying Wang, Changshun Shao, Jianan Huang, Jianhe Gan, Xiaoping Huang, Enrico Bucci, Mauro Piacentini, Giuseppe Ippolito & Gerry Melino
Abstract
Clinically, the immune responses induced by SARS-CoV-2 infection are two phased. During the incubation and non-severe stages, a specific adaptive immune response is required to eliminate the virus and to preclude disease progression to severe stages. Therefore, strategies to boost immune responses (anti-sera or pegylated IFNα) at this stage are certainly important. For the development of an endogenous protective immune response at the incubation and non-severe stages, the host should be in good general health and an appropriate genetic background (e.g. HLA) that elicits specific antiviral immunity.
Lung damage is a major hurdle to recovery in severe patients. Through producing various growth factors, MSCs may help repair of the damaged lung tissue. It is important to mention that various studies have shown that in animal models with bleomycin-induced lung injury, vitamin B3 (niacin or nicotinamide) is highly effective in preventing lung tissue damage. It might be a wise approach to supply this food supplement to the COVID-19 patients.
Doctors should try to boost immune responses during the first, while suppressing it in the second phase. Since Vitamin B3 is highly lung protective, it should be used as soon as coughing begins. When breathing difficulty becomes apparent, hyaluronidase can be used intratracheally and at the same time 4-MU can be given to inhibit HAS2. Of course, HLA typing will provide susceptibility information for strategizing prevention, treatment, vaccination, and clinical approaches. We hope that some of the above ideas can be employed to help combat this deadly contagious disease of increasing incidence around the world. 
Cell Death & Differentiation volume 27, pages1451–1454(2020), Download PDF

COVID-19: is there a role for immunonutrition, particularly in the over 65s?

Emma Derbyshire and Joanne Delange

Abstract

In late December 2019 severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) first emerged in Wuhan, Hubei, China, resulting in the potentially fatal COVID-19. It went on to be officially recognised as a pandemic by the World Health Organisation on 11 March 2020. While many public health strategies have evolved, there has been little mention of the immune system and how this could be strengthened to help protect against viral infections such as SARS-CoV-2. The present paper evaluates the current evidence base relating to immunonutrition, with a particular focus on respiratory viruses. Within the nutrition sector a promising body of evidence studying inter-relationships between certain nutrients and immune competence already exists. This could potentially be an important player in helping the body to deal with the coronavirus, especially among elders. Evidence for vitamins C, D and zinc and their roles in preventing pneumonia and respiratory infections (vitamins C and D) and reinforcing immunity (zinc) appears to look particularly promising. Ongoing research within this important field is urgently needed. 

Enhancing immunity in viral infections, with special emphasis on COVID-19: A review

Ranil Jayawardena Piumika Sooriyaarachchi Michail Chourdakis Chandima Jeewandara Priyanga Ranasinghe
Abstract

Balanced nutrition which can help in maintaining immunity is essential for prevention and management of viral infections. While data regarding nutrition in coronavirus infection (COVID-19) are not available, in this review, we aimed to evaluate evidence from previous clinical trials that studied nutrition-based interventions for viral diseases (with special emphasis on respiratory infections), and summarise our observations. A systematic search strategy was employed using keywords to search the literature in 3 key medical databases: PubMed®, Web of Science® and SciVerse Scopus®. Studies were considered eligible if they were controlled trials in humans, measuring immunological parameters, on viral and respiratory infections. Clinical trials on vitamins, minerals, nutraceuticals and probiotics were included. A total of 640 records were identified initially and 22 studies were included from other sources. After excluding duplicates and articles that did not meet the inclusion criteria, 43 studies were obtained (vitamins: 13; minerals: 8; nutraceuticals: 18 and probiotics: 4). Among vitamins, A and D showed a potential benefit, especially in deficient populations. Among trace elements, selenium and zinc have also shown favourable immune-modulatory effects in viral respiratory infections. Several nutraceuticals and probiotics may also have some role in enhancing immune functions. Micronutrients may be beneficial in nutritionally depleted elderly population.  https://doi.org/10.1016/j.dsx.2020.04.015

Early Supplementation in COVID-19

Early nutritional supplementation in non-critically ill patients hospitalized for the 2019 novel coronavirus disease (COVID-19): Rationale and feasibility of a shared pragmatic protocol

Riccardo Caccialanza M.D. Alessandro Laviano M.D. Federica Lobascio M.D. Elisabetta Montagna R,D Raffaele Bruno M.D. Serena Ludovisi M.D. Angelo Guido Corsico M.D., Ph.D. Antonio Di Sabatino M.D. Mirko Belliato M.D. Monica Calvi Pharm .D. IsabellaIacona Pharm .D. Giuseppina Grugnetti R.N. Elisa Bonadeo M.D. Alba Muzzi M.D. Emanuele Cereda M.D. Ph.D.

Abstract

Beginning in December 2019, the 2019 novel coronavirus disease (COVID-19) has caused a pneumonia epidemic that began in Wuhan, China, and is rapidly spreading throughout the whole world. Italy is the hardest hit country after China. Oral supplementation of whey proteins as well as intravenous infusion of multivitamin, multimineral trace elements solutions are implemented at admission. In the presence of 25-hydroxyvitamin D deficit, cholecalciferol is promptly supplied. If nutritional risk is detected, two to three bottles of protein-calorie oral nutritional supplements (ONS) are provided. If <2 bottles/d of ONS are consumed for 2 consecutive days and/or respiratory conditions are worsening, supplemental/total parenteral nutrition is prescribed. 

Saturday, May 2, 2020

Vitamin D & COVID-19

Evidence that Vitamin D Supplementation Could Reduce Risk of Influenza and COVID-19 Infections and Deaths

William B. Grant 1,*,Henry Lahore 2,Sharon L. McDonnell 3,Carole A. Baggerly 3,Christine B. French 3,Jennifer L. Aliano 3 andHarjit P. Bhattoa 4


Abstract

The world is in the grip of the COVID-19 pandemic. Public health measures that can reduce the risk of infection and death in addition to quarantines are desperately needed. This article reviews the roles of vitamin D in reducing the risk of respiratory tract infections, knowledge about the epidemiology of influenza and COVID-19, and how vitamin D supplementation might be a useful measure to reduce risk. Through several mechanisms, vitamin D can reduce risk of infections. Those mechanisms include inducing cathelicidins and defensins that can lower viral replication rates and reducing concentrations of pro-inflammatory cytokines that produce the inflammation that injures the lining of the lungs, leading to pneumonia, as well as increasing concentrations of anti-inflammatory cytokines. Several observational studies and clinical trials reported that vitamin D supplementation reduced the risk of influenza, whereas others did not. Evidence supporting the role of vitamin D in reducing risk of COVID-19 includes that the outbreak occurred in winter, a time when 25-hydroxyvitamin D (25(OH)D) concentrations are lowest; that the number of cases in the Southern Hemisphere near the end of summer are low; that vitamin D deficiency has been found to contribute to acute respiratory distress syndrome; and that case-fatality rates increase with age and with chronic disease comorbidity, both of which are associated with lower 25(OH)D concentration. To reduce the risk of infection, it is recommended that people at risk of influenza and/or COVID-19 consider taking 10,000 IU/d of vitamin D3 for a few weeks to rapidly raise 25(OH)D concentrations, followed by 5000 IU/d. The goal should be to raise 25(OH)D concentrations above 40–60 ng/mL (100–150 nmol/L). For treatment of people who become infected with COVID-19, higher vitamin D3 doses might be useful. Randomized controlled trials and large population studies should be conducted to evaluate these recommendations. 
View Full-Text

Nutrients 202012(4), 988; https://doi.org/10.3390/nu12040988


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