Photodynamic Therapy

The development of antibiotics was an important advancement in 20th century medicine. Previously deadly infectious diseases are now routinely treated with antibiotics. Moreover, for modern-day medical procedures such as chemotherapy treatment to be successful, antibiotic use is necessary. For these reasons, the prospect of bacteria developing widespread resistance to antibiotics is a major concern as it would render many modern-day medical therapies unviable.

Most of the ill-causing bacteria will be killed but the ones that don’t die, carry a gene or genes that allows them to withstand the antibiotic. These bacteria are better adapted to deal with the antibiotic. This adaptation will become stronger as it is passed. When these bacteria reproduce, they will pass the genes on to the next generation and the next generation bacteria better adapted against the antibiotic. The more they reproduce, the more antibiotic resistant bacteria will be in the individual eventually becoming totally resistant. This is an example of directional selection in the natural selection process. The bacteria with the resistant genes would become the favored extreme phenotype.

Bacteria are not just all of a sudden becoming resistant to antibiotics they have always had a bit of resilence, as a human species we have always developed something it doesn’t work we will develop something stronger, that has been the downfall in this instance. Pencillan is a great example as it is one of the most highly used antibiotic and is derived and made from mold.

Antibiotics are inarguably one of the greatest advances in medical science of the past century. Although the first natural antibiotic Penicillin was not discovered until 1928 by Scottish biologist Alexander Flemming, evidence exists that certain plant and mold growths were used to treat infections in ancient Egypt, ancient India, and classical Greece (Forrest, 1982). In our modern world with the advent of synthetic chemistry synthetic antibiotics like Erithromycin and its derivative Azithromycin have been developed. Antibiotics have many uses including the treatment of bacterial and protozoan infection, in surgical operations and prophylactically to prevent the development of an infection. Through these applications, antibiotics have saved countless lives across the world and radically altered the field of medicine. Though a wonderful and potentially lifesaving tool, antibiotic use is not without its disadvantages. Mankind has perhaps been too lax in regulation and too liberal in application of antibiotics and growing antibiotic resistance is the price we must now pay. A recent study showed that perhaps 70% of bacterial infections acquired during hospital visits in the United States are resistant to at least one class of antibiotic (Leeb, 2004). Bacteria are not helpless and their genetic capabilities have allowed them to take advantage of society’s overuse of antibiotics, allowing them to develop

UV radiation, such as that from the sun can be very harmful. It has been shown to cause many different mutations within cells, leading to issues for the organism such as death or disease. One of the most prevalent sources of UV radiation for humans is the sun. It’s very important for us to know the extent of cellular damage that can be caused by this radiation, as to know how harmful the sun’s rays are to us as humans. One way that the damage caused by the suns radiation can be tested is through the model organism yeast. For this lab, we exposed two different strains of yeast to UV radiation to test its affects. One strain was able to self-repair, while one was genetically altered so that it could not. Observations were recorded at

Antibiotic resistance evolves in bacteria. Charles Darwin created the theory of evolution which focused on natural selection being the key factor of how things change. Natural selection is when organisms that are better suited to the environment are able to reproduce successfully. Evolution is descent with modification. Bacteria can become resistant to antibiotics by a mutation. The bacteria that did not die from the antibiotic inherited the gene from an ancestor that made it resistant. Since the other bacteria is dying faster than the resistant bacteria, the resistant bacteria are able to multiply

Tsien, Roger Y. "THE GREEN FLUORESCENT PROTEIN." Annual Review of Biochemistry 67 (1998). Howard Hughes Medical Institute. Web. 7 Nov. 2016.

· Be able to describe how antibiotic resistant genes are able to transfer, and identify the transformed cells that are antibiotic resistant

So if a bacterium has a gene resistant to Penicillin dies and another bacterium picks up that gene, now the bacterium that is alive is resistant to Penicillin. This allows the bacteria that die to still have an influence in the colony. The second method is called transduction or the passing of virus. Since virus are just pieces of DNA or RNA they can latch onto genes from one bacterium and then transfer them to another bacterium thus giving more bacteria that gene that may be resistant to a specific antibiotic such as penicillin. The final method is called conjugation which allows bacteria to create a gene transferring connection with each other and when they break apart both bacteria can gain genes from each other allowing them to be resistant to possibly two antibiotics. Horizontal gene transfer is bacteria biggest weapon against everything we throw at them. So the question is can we evolve our own weapons, antibiotics, fast enough to counter these methods bacteria use to survive (Hobley,

Stereotactic photon beam irradiation has been under clinical investigation for the treatment of uveal melanoma for over 15 years. The efficacy of SRS for uveal melanoma has been proven in different studies with local tumor control rates reported over 90 % (Mueller et al. 2000; Dieckmann et al. 2003; Krema et al. 2009). High rates of local control can be also achieved with 5-year control rates exceeding 95 % in patients treated with proton-beam irradiation (Meyer et al. 2000). Reported case series suggest that SRS can have similar local tumor control rate, metastasis rate, mortality rate and complications rate when compared to brachytherapy. The findings in the series suggest a role of SRS in the treatment of selected cases of uveal melanoma (Seddon et al. 1990; Ghazi et al. 2008).

Radiation therapy is the ionization of atoms in tissues resulting in formation of highly reactive radicals in a well-defined, restricted volume (1). In other words, ionizing radiations are used to eradicate tumors and at the same time preserve structure and function of normal tissue. A limitation is prevented from being a problem. If bone marrow or neuronal cells are destroyed or injured, they do not regenerate. However, with radiation therapy, these cells are often saved from injury or destruction, unless the tumor is infecting bone marrow or neuronal cells. Today, radiation therapy is the most popular type of cancer therapy in use. It is used to treat one-half to two-thirds of all cancers, which translates to more than ten percent of the population

Photodynamic Diagnosis (PDD) or Fluorescence Diagnosis (FD) is designed on detection of premalignant lesions and cancer tumors through recording and evaluation of fluorescence emission profile. Photodynamic Diagnosis (PDD) is a modern method and a minimally invasive approach based on one of these processes: Autofluorescence of tissue, fluorescence of a chemiluminescence probe or fluorescence after local or systemic administration of a photosensitizer (PS), selectively accumulating in pathological foci. Necessary conditions for successful Photodynamic Diagnosis (PDD) are selectivity and good uptake of photosensitizer (PS) by the pathologic cells and providing possibility of real–time data processing, additionally high precision and sensitivity

In 2007, it is predicted that almost 1.5 million people will be diagnosed with cancer in the United States (Pickle et al., 2007). More than half of these cancer patients will undergo the use of radiation as a means for treating cancer at some point during the course of their disease (Perez and Brady, 1998). Cancer, a disease caused by an uncontrollable growth of abnormal cells, affects millions of people around the world. Radiotherapy is one of the well known various methods used to treat cancer, where high powered rays are aimed directly at the tumor from the outside of the body as external radiation or an instrument is surgically placed inside the body producing a result of internal radiation. Radiation is delivered to the cancerous regions of the body to damage and destroy the cells in that area, terminating the rapid growth and division of the cells. Radiation therapy has been used by medicine as a treatment for cancer from the beginning of the twentieth century, with its earliest beginnings coming from the discovery of x-rays in 1895 by Wilhelm Röntgen. With the advancements in physics and computer programming, radiation had greatly evolved towards the end of the twentieth century and made the radiation treatment more effective. Radiation therapy is a curative treatment approach for cancer because it is successful in killing cancerous tumor cells and stop them from regenerating.

Microbiologists believe that Mycobacterium tuberculosis becomes antibiotic resistant when it exchanges genes with other already resistant bacteria because bacteria mutate and spread rapidly within hours. There are three forms of gene mutations categorized as conjugation, transformation, and transduction. Conjugation permits the transfer of DNA from one cell to another whereas transformation occurs when a cell decays. While its cell wall falls apart, the inner genetic makeup becomes available to other

Less than 50 years after penicillin was discovered, strains of bacteria were discovered to be resistant to antibiotics (Haddox, 2013). Over the years scientists have changed the structure of the antibiotics to avoid this resistance, every time the bacteria adapts to overcome the changes. Bacteria divides as fast as 20 minutes and have many different ways to adapt (Haddox, 2013). Bacteria pass their drug resistance between strains and species, causing antibiotics to be less effective to all bacteria (Haddox, 2013).