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Increase in ampicillin resistane began years before human use

Submitted by tterrasi on Wed, 12/06/2017 - 09:18

Antibiotic resistance kills about 25,000 people every year in Europe. Many bacteria cause serious infections in humans like Salmonella, which have developed resistance to other common antibiotics. Ampicillin was the first broad-spectrum antibiotic used for treatments of infections caused by enterobacteria. This was first released in the United Kingdom in 1961. Soon after, between 1962-1964, the first outbreak of this disease in humans was caused by ampicillin-resistance strains of Salmonella enterica serotype Typhimurium. The study aimed to date the first occurrence and spread of the resistant strain.

Increase in ampicillin resistane began years before human use

Submitted by tterrasi on Mon, 12/04/2017 - 17:56

            Antibiotic resistance kills about 25,000 people in Europe every year. Many other bacteria cause serious infections in humans like Salmonella have also developed resistance to other common antibiotics. Ampicillin was the first broad-spectrum antibiotic used for treatments of infections caused by enterobacteria. This was first released in the United Kingdom in 1961. Soon after, between 1962-1964, the first outbreak of this disease in humans was caused by ampicillin-resistance strains of Salmonella enterica serotype Typhimurium. The study aimed to date the first occurrence and spread of the resistant strain.

            The scientists tested and analyzed 288 S. enterica serotype Tymphimurium samples from 30 different countries between early to mid-late 1900s (1911-1969). The isolated were from many sources including humans, animals, and food. Using the disc diffusion method, these isolated were tested for susceptibility to drug resistance. Using whole-genome-wide association sequencing, 11 out of the 288 samples were found to be resistance to ampicillin, due to Beta-lactamase genes, transported by different plasmids.  One of these isolates was from France in 1959, before ampicillin was on the market for sale. This strain was different from those reported in the outbreaks in the United Kingdom.

 

Literature Cited

Alicia Tran-Dien, Simon Le Hello, Christiane Bouchier, François-Xavier Weill. Early transmissible ampicillin resistance in zoonotic Salmonella enterica serotype Typhimurium in the late 1950s: a retrospective, whole-genome sequencing study. The Lancet Infectious Diseases, 2017; DOI: 10.1016/S1473-3099(17)30705-3.

 

 

To Label or Not to Label?

Submitted by tterrasi on Tue, 11/28/2017 - 20:06

            Genetically Modified Organisms, also called GMOs, are the result of genes from one species DNA that is incorporated artificially into the genes of another organism. The foreign gene can be from bacteria, plants, viruses, or other animals. When you go to the grocery store or a farmer’s market to buy fruits or vegetables, you may wonder if what you are going to buy is a GMO. As of today, the Food and Drug Administration does not require precise identification and labeling of produce that is made from genetically engineered plants (U.S. Food and Drug). According to The Mellman Group Incorporated, 89 percent of poll voters were in favor of mandatory labeling of GMOs (Center for Food Safety). If the majority of the American population is in support of the FDA labeling GMOs, then why does the government not want GMOs to be labeled? This is the current state in the debate: to label or not to label.

To Label or Not to Label?

Submitted by tterrasi on Mon, 11/27/2017 - 22:48

            Genetically Modified Organisms or GMOs, are the result of genes from one species DNA that is incorporated artificially into the genes of another organism. The foreign gene can come from bacteria, plants, viruses, or other animals. When you go to the grocery store or a farmer’s market to buy fruits or vegetables, you may wonder if what you are going to buy is a GMO. As of today, the Food and Drug Administration do not require precise identification and labeling of produce that was made from genetically engineered plants (U.S. Food and Drug). According to The Mellman Group Incorporated, 89 percent of poll voters were in favor of mandatory labeling of GMOs (Center for Food Safety). If the majority of the American population wants the FDA to label GMOs, then why doesn’t the government want GMOs to be labeled? This is the current state in which the debate is still at.

            If you go to the store and pick out a food item, you can certainly look at the label for the ingredients and nutrition levels to make a judgment is the food item is relatively healthy or has the right amount of nutrients. But you cannot look at a food item as tell whether it is a GMO or not. Let us first look at the pros and cons for labeling. Some of the benefits of labeling would be that the customer has the right to know what he or she is consuming. If a customer is concerned about a GMO ingredient that is found in a food product they are purchasing, labeling will help them to determine what to purchase. Vegetarians and religious groups and people who choose to not eat GMOs to quickly move to another product. Also, over 50 countries already have laws that require GMO labeling. Some of the downsides to labeling would be a lack of understanding of what a GMO is and what it means for that consumer. While customers will easily determine which products contain GMOs, a small portion of the population who doesn’t correctly understand what GMOs are could hurt the manufacturers, as a GMO label would connote a warning label instead. Also, labeling if a product is GMO would not tell the customer what they might really want to know, which would be if pesticides or herbicides were used on this product. There is a stigma that is attached to the word GMO, which has the same connotation as “unhealthy” according to Hoewyk. Labeling would tell the customer so little about the product that labeling could only lead to more confusion and add to the stigma of unnatural and make people who are against GMOs to be more frightened.

            The view for labeling of GMOs is widespread. According to The Center for Food Safety article, an overwhelming majority of democrats, republicans and independents are in favor for labeling. So why hasn’t labeling laws been passed? Hoewky sites from the American Association for the Advancement of Science, American Medical Association and the American Society of Plant Biologist that the scientific evidence shows that consumption of GMOs are not harmful or nutritionally inferior. There are many examples of GMOs that are more beneficial and more biologically fit than it’s wild-type version like strawberries, potatoes, and bananas just to name a few. Looking at the banana, the previous version of the banana that was in the world market was the Gros Michel up until the 1950s when it went extinct due the Panama Disease. This species led to another variant called the Cavendish, which is the species we eat today. The stigma as unnatural or unhealthy should not be associated with GMOs. GMO labeling is about a much broader debate than just a labeling debate. It is about the Public’s health as well as the sustainability of the world food supply, which further has direct ties with social, economic and political thoughts and results.

Data from a “living” oxygen minimum lab could help predict the oceans future

Submitted by tterrasi on Mon, 11/13/2017 - 12:25

Researchers have collected 50 years of data showing the deoxygenating cycles of a fjord on the coast of Vancouver Island, cataloging the response of the microbial communities inhabiting this environment. Marine oxygen minimum zones (OMZs) are widespread and contribute up to 7 percent of global oceans. Expansion of these OMZs has potential to bring oxygen-depleted water into new regions, affecting fish populations and nutrient cycles. Environments of low-oxygen are not well suited for most metazoans, but microbial life can flourish. As oxygen becomes limiting, microbial communities can change their metabolism to use alternative electron sources like nitrogen, carbon, and sulfur. These microbial communities can drive nutrient cycling essential for ecosystem function and diversity. The research team collected data using time-series monitoring and multi-omic sequencing (DNA, RNA, and protein) to study microbial responses to deoxygenated ocean areas. By using this data, reconstruction of microbial communities metabolism can predict future responses to ocean deoxygenating.

Data from a “living” oxygen minimum lab could help predict the oceans future

Submitted by tterrasi on Sun, 11/12/2017 - 21:02

            Researchers have collected data over a 50-year span, showing the deoxygenating cycles of a fjord on the coast of Vancouver Island, and cataloging the response of the microbial communities inhabiting this environment. Marine oxygen minimum zones (OMZs) are widespread and contribute up to 7 percent of global oceans. Expanding of these OMZs has potential to bring oxygen-depleted water into new regions, affecting fish populations and nutrient cycles. Environments of low-oxygen are not well suited for most metazoans, but microbial life can flourish. As oxygen becomes limiting, microbial communities can change their metabolism to use alternative electron sources like nitrogen, carbon, and sulfur. These microbial communities can drive nutrient cycling, essential for ecosystem function and diversity. The research team collected data using time-series monitoring and multi-omic sequencing (DNA, RNA, and protein) to study microbial responses to oxygen-depleted ocean areas. By using this data, reconstruction of microbial communities metabolism can predict future responses to ocean deoxygenating.

Seedlings change over time in monoculture

Submitted by tterrasi on Thu, 11/09/2017 - 23:00

 In a monoculture stand of plants, the number and size of seedlings can change over time. Individual plant sizes are generally extremely uneven. Usually, a few large individuals dominate an available area given, while most individuals remain very small.  This unevenness is highly unequal in size distribution, which is characterized by size hierarchies that can be attributed to asymmetric competition – larger individuals have negative effects on smaller neighboring individuals. For example, starting with a population that is relatively homogeneous, as time goes on, the distribution becomes increasingly unequal with the proportion of smaller plants increasing and smaller number of large plants. Eventually, self-thinning occurs, which is when death removes the smallest individuals from the population, in this case, so that the population is less unequal as time goes on. This shows that plant sizes vary in a cycle from having more plants of one size over the other. Also, as a population increases in size, it can reach a maximum capacity, which then individuals start dying due to reduced resources.

Seedlings change over time in monoculture

Submitted by tterrasi on Wed, 11/08/2017 - 20:22

 In a monoculture stand of plants, the number and size of seedlings can change over time. Individual plant sizes are generally extremely uneven. Usually, a few large individuals dominate an available area given, while most individuals remain very small.  This unevenness is highly unequal in size distribution, which is characterized by size hierarchies that can be attributed to asymmetric competition – larger individuals have negative effects on smaller neighboring individuals. With a starting population that is relatively homogeneous, as time goes on, the distribution becomes increasingly unequal with the proportion of smaller plants increases and smaller number of large plants. Eventually, over time, self-thinning occurs, which is when death removes the smallest individuals from the population, in this case, so that the population is less unequal as time goes on.

Cancer: causes and development

Submitted by tterrasi on Tue, 10/24/2017 - 11:11

Tumors are classified, as either benign or malignant, meaning the tumor is non-cancerous or cancerous. DNA damage is one possible way cells turn into cancer cells. This can occur due to many factors, such as exposure to toxins, radiation, diet, infection, and hormones. Cancer mutations are progressive and happen in multiple steps. Firstly, a normal functioning cell will divide into daughter cells by mitosis, but one or more of the daughter cells will have a mutation. By the time a cell divides three or even four more times, the cell is highly likely to be cancerous. The more often mutated cells divide the more likely the cell will be malignant, grow uncontrollably and have an abnormal phenotype (Kleinsmith).  When a normal cell grows, the cell goes through checkpoints to ensure that the cell is mature and function properly. But, cancer cells evade this process and divide uncontrollably, not going through an apoptotic pathway. Also, growth factors, which are proteins, stimulate cell growth and division. In cancer cells, growth receptors can be mutated so that these signals are always on to tell the cell to divide. In normal cells, these signals are turned on and off. If the cell was always on and is always dividing, then tumors will develop, and can eventually spread throughout the body by metastasis (Kleinsmith).

 

Cancer: causes and development

Submitted by tterrasi on Mon, 10/23/2017 - 21:17

               Cancer is a complex group of diseases with many possible causes. There are many different factors that cause cancer development in organisms. According to The American Cancer Society, genetic factors, tobacco use, diet and physical activity, infections and environmental exposures to different types of chemicals and radiation are only a few factors that lead to cancer. The uncontrolled proliferation of cancer cells, combined with their ability to spread throughout the body, makes cancer a potentially life-threatening disease (Kleinsmith).                 

               There are a few steps that lead to cells becoming tumors before it turns into cancer. Cancer develops when cells in a part of the body begin to grow out control. These cells arise due to damage to DNA. There are three main gene families that are major factors to cancer: Oncogenes, DNA repair genes, and tumor suppressor genes. Damaged genes can be inherited, but most often caused by environmental factors. In cancer cells, the damaged DNA is not repaired and does not undergo apoptosis. After this, the cell begins to divide rapidly and then uncontrolled cell division leads to tumor development (Keinsmith).                              

                Tumors are benign or malignant, meaning the tumor is either non-cancerous or cancerous. DNA damage is how cells can turn into cancer cells. This can occur in many ways like exposure to toxins, radiation, diet, infection, hormones, and others as listed above. Cancer mutations are progressive and happen in multiple steps. A normal cell will divide into daughter cells by mitosis, but one or more of the daughter cells will have a mutation. By the time a cell divides three or even four more times, the cell is highly likely to be cancerous. The more the mutated cell divides the more likely the cell will be malignant, grow uncontrollably and look deranged or abnormal (Kleinsmith).  When a normal cell grows, the cell goes through checkpoints to make sure that the cell is mature and ready to function. But, cancer cells ignore this process and divide uncontrollably. Also, growth factors, which are proteins, stimulate cell growth and division. In cancer cells, growth receptors can be mutated so that these signals are always on to tell the cell to divide. In normal cells, these signals are turned on and off. If the cell was always on and are always dividing, then tumors will develop all over the body (Kleinsmith).

Works Cited:

Kleinsmith, L (2006). Principles of Cancer Biology. Chapters 1-4.

The American Cancer Society. http://www.cancer.org/cancer/cancercauses/ 25 June 2014. Web, 23 October 2017.

 

           

 

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