C-myc Monocular Antibody (McAb) on Gastric Cancer Cells

C-myc Monocular Antibody (McAb) on Gastric Cancer Cells Introduction Gastric cancer (GC) is estimated to be one of the most common and frequent malignant tumor of the digestive system. The incidence and mortality of GC have ranked the second among all tumor diseases worldwide [1-5]. However, it ranks in first place in China[6]. Complete surgical resection is still the standard for all patients with resectable GC. It remains highly problematic for the regional and less common systemic recurrences[7]. Recent improvement in surgical technique, adjuvant chemotherapy and radiotherapy has increased the survival rate of patients with early-stage, but the patients who have advanced GC are difficult to cure. With more and more research of molecular biological mechanisms known by us, molecular targeted therapies including cell growth, cell cycle, apoptosis and invasion have become a popular tumor comprehensive therapy[8]. Some of single-targeted spots are mainly Human epidermal growth factor receptor (HER-1, HER-2), Vascular endothelial growth factor (VEGF), Human epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI), Cyclin-dependent kinase inhibitor (CDKI), Human proto-oncogene (c-MET)[9, 10]. However, it needs a huge space to develop the targeted anticancer drugs. An elegant way to accumulate therapeutic agents at the tumor site is their specific antibodies[11]. Oncogenes are well documented to be involved in mediating apoptosis and cell cycle resulting in cancers[12, 13], its activation can play an important role in the progress of cancer. C-myc is an important member of the c-myc family and a master regulator of genes involved in diverse cellular processes in GC[14]. The c-myc is a nuclear transcription factor which centrally regulates cell proliferation, differentiation, cell cycle and apoptosis, once c-myc is activated in vivo or in vitro, it is easy to make the cells far from the normal growth and promote cell malignant transformation to cancer finally[15-17]. It was reported that the expression of c-myc is an important consideration in the biological characteristic of GC [18-20]. The previous studies also have proved that c-myc has tight relation with Brest cancer, lung cancer, colon cancer, hematopoietic cancer [21-24]. Currently few da ta exist on the occurrence of the c-myc McAb targeting against GC. In this study, we assessed the effects of c-mycMcAb on the Balb/e2nu/2nunude mice model of GC and the human gastric cancer SGC-7901 cells, and tried to investigate the function of c-myc McAbfor targeting against GC. Materials and Methods Preparation of c-myc monocular antibody (McAb) All experiments involving animals were approved by the Institutional Animal Care and Use Committee of Renji Hospital Affiliated to Shanghai Jiao Tong University of Medicine. Mice were used in this study from Animal Science Laboratory of Shanghai Jiao Tong University, and all effects were made to minimize distress.Thec-myc proteins prepared in E.coliBL21 were used as immunogens.[U1] Before McAb preparation, the c-myc proteins were mixed withequal volume of complete Freund's adjuvant (CFA). Female Balb/c mice aging from 6-8 weeks [U2]were immunized intraperitoneally with 50 ÃŽ ¼g c-myc proteins (1v:1v) in CFA. The immunization was repeated with the same amount of immunogens[U3] in incomplete Freund's adjuvant (IFA) at 14d. A final immunization was performed with 100ÃŽ ¼g mixture of c-myc proteinsand IFA at 28 d. Then, the blood was drawn from the caudal vein and serum titers were measured by ELISA at 35 d. A booster injection was given intraperitoneally at the antibody titers of 640,000[U4] tested by ELISA at 35 d. Five days after boost, spleen cells were isolated and mixed[U5] with SP2/0 myeloma cells. When the Hybrid cells grew to 50%, the positive clones were collected by ELISA. The hybridomas processed by Silica gel H was inoculated intraperitoneally into unsexed Balb/c mice. Then, the mice were scarified and the ascetic fluid was collected. The McAb was purified and the concentration was determined by bicinchoninic acid assay (BCA) Protein Assay Reagent Kit. Characteristic Identification of c-myc McAb The subtype of purified McAb was determined by antibody chips according to the manufacturer's instructions (Raybitech Company, USA) and antibody titers were measured by ELISA kit (Cistron Biotechnology, Pine Brook, NJ)[25]. The assay was carried out in 96-well polystyrene plates according to the standard procedures [26]. Briefly, c-myc protein (10ÃŽ ¼g) were loaded onto plate in 0.1 M carbonate buffer (PH 9.6) and reacted with McAb at 37oC for 2 h. After washed, the mixture was monitored with horseradish peroxidase (HRP)-conjugated rabbit-anti-mouse IgG (diluted 1:100; Sigma) at 37oC for 1 h. Nonspecific antibody binding sites wereblocked with 2% FCS in blocking reagent for 15min.The OD450vaule was read with a 96-well plate reader. The antigenic specificity of McAb was determined by Western blot. Purified c-myc protein was transferred into E.coil DH5ÃŽ ± and Cells were lysed inice-cold radioimmunoprecipitation buffer (RIPA) for 30 min and centrifuged to collect the supermanant[27]. Cell lysates were blent with 3Ãâ€" loading buffer (6 % SDS, 15 % 2-mercaptoethanol, 30 % glycerol, and 0.3 mg/mL bromphenol blue in 188 Tris-HCl, pH 6.8), heated at 90oC for 10 min, and then separated by 16 % SDS-PAGE. Separated proteins in the gels were electrophoreticaly transferred onto nitrocellulose membrane, boiled in phosphate buffered saline for 4 min, and blocked with 5 % nonfat dry milk for 20 min[28]. After several rinses, the membranes were incubated with c-myc McAb overnight at 4 oC. McAb were detected by HRP-conjugated goat-anti-mouse IgG (50 ÃŽ ¼g/mL) at 22 oC for 1 h. The establishment and treatment of nude mice model of GC Four-to-five-weeks old Balb/c nu/nu mice (body weight was 18 ±1.5g) were purchased for the establishment of nude mice model of GC . The human gastric cancer cell line (SGC-7901) was grown in 10% DMEM (Gibco) supplemented with FCS (100 mL/L), penicillin sodium (100 U/mL) and streptomycin sulfate (100 ÃŽ ¼g/mL), and cultured at a 5% CO2 incubator at 37 oC. Exponentially growing SGC-7901 cells were trypsinized resuspended to make a cell suspension of 2Ãâ€"107 cellls/mL. The nude mouse was injected subcutaneously with the suspension (0.2 mL) into the right and left root. Tumor masses were obvious at 10 d. Mice were randomized into 4 groups including low-dose group, middle-dose group, high-dose group and saline group (10 mice/group). Mice of each treatment group were inoculated intraperitoneally with c-myc McAb weekly (10 mg/kg, 20 mg/kg, 30 mg/kg, respectively), and mice of saline groups were injected with normal saline (0.2 mL) instead. Four weeks after injection, the mice were sacrificed and tumors were examined to calculate the tumor inhibition rates (). Immunohistochemistry (IHC) The procedures of SP immunohistochemical kit (SP kit, Maxim Biotech) were as follows: The tissue of tumors was fixed in 10 % phosphate-buffered Formalin, embedded in paraffin, and sectioned at a thickness of 4ÃŽ ¼m. Tissue sections were deparaffnized, hydrated and washed in PBS. Antigen retrieval was performed by combining the tissue with 10mM citrate buffer (pH 6.0) in a microwave for 10 min. Nonspecific protein bindings of tissues was blocked with 5 % normal sheep serum (NSS) for 10 min. after rinsing in PBS, sections were incubated with c-myc McAb at 4 oC overnight at a dilution of 1:100. Secondary antibody (Carpinteria, goat anti-mouse biotenylated, 1:50 in PBS) was applied at room temperature for 30min after washed, and then HRP-conjugated streptavidin were added. The slides were visualized by diaminobenzidine (DAB) (Dako, Carpinteria, CA, USA) for 5 min and counterstained with hematoxylin for 2 min, terminated, dehydrated, transparentized, sealed and photographed step by step. Negative controls were prepared by replacing primary antibody with PBS. Western blot analysis C-myc McAb (1 ÃŽ ¼g/mL, 2 ÃŽ ¼g/mL, 4 ÃŽ ¼g/mL, respectively) were added into SGC-7901cells andcultured for 24 h, 48 h, 72 h, for blank controls, the SGC-7901cells were omitted and HFE-145 cells were used instead. Cells were collected and lysed in ice-cold RIPA,and then following sections were mainlysimilar with the procedures of the Characteristic Identification of c-myc McAb. MTT (3-(4, 5-dimethylthiazole-2-yl)-2, 5-diphenyl tetrazolium bromide) assay Cells were seeded into 96-well plates (10, 000 cells/well) and cultured at 37 oC in a 5% CO2 incubator after HGC-7901cells and normal gastric cell line HFE-145 were trypsinized. The culture medium was washed with PBS 3 times, and thenc-myc McAb (1 ÃŽ ¼g/mL, 2 ÃŽ ¼g/mL, 4 ÃŽ ¼g/mL,) were added respectively, 20 mL (5 mg/mL) At the indicated time points (1 d, 2 d, 3 d, 4 d, 5 d), each well were added with 20 mL MTT cultured at 37 oC for 4 h. Then 150 ÃŽ ¼L DMSO was added again to stop the reaction after the supernate were dropped, The plate was read on multiwall plate reader (Thermo Fisher, Basingstoke, United Kingdom) at 570nm. . A dose-response curve was plotted for the HGC-7901cells and HFE-145 cells. Cell adhesion assay Before cell adhesion and migration assays, SGC-7901 cells and HFE-145 cells were serum starved in bascal culture medium overnight. In brief,6-well tissue culture plates were coated with 10ÃŽ ¼g/mL fibronectin and 10 ÃŽ ¼g/mL poly-L-lysine overnight, the wells were washed with PBS-T and blocked with 5 % BSA in PBS-T[29]. SGC-7901cells and HFE-145 cells were released with trypsin to prepare of single cell suspensions. The cells were applied to 6-well tissue culture plates (50 ÃŽ ¼L/well) and incubated at 37oC for 12 h. When cells were grown to approximately 90 % confluence, the c-myc McAb(1 ÃŽ ¼g/mL, 2 ÃŽ ¼g/mL, 4 ÃŽ ¼g/mL,) were added respectively. Cells were allowed to attach for 2 h, and the culture medium were discarded. Before released with trypsin, cells were washed twice with PBS and 1mM Ethylene Diamine Tetraacetic Acid (EDTA). The formula of was used to calculate the adhesion rates. Cell migration assay Cell migration assays were performed in transwell bicameral chambers as described[30]. Matrigel (Becton Dickinson Company, Bedford) at a dilution of 1:100 were coated with culture medium without serum at 37oC for 30 min in the apical chamber. Cells were released with trypsin, washed ,and resuspended at a final concentration of 5Ãâ€"105 cell/mL in serum-free bascal culture medium (EBM) containing 0.1 % BSA. The suspension (100 ÃŽ ¼L), which were seeded on the upper chamber, were mixed with c-myc McAb (1 ÃŽ ¼g/mL, 2 ÃŽ ¼g/mL, 4 ÃŽ ¼g/mL, respectively). The lower chamber was filled with 500ÃŽ ¼L mouse embryonic fibroblasts (NIH3T3) which were cultured with RPMI (10mM Hepes, 0.5% BSA, pH 7.4). Migration chambers were incubated at 37oC in 5% CO2 incubator for 72h. After removing stationary cells from the upper side of the membrane with a cotton-tipped swab, migrated cells were fixed and stained with 1% crystal violet. Cells were counted in three fields at a magnification of Ãâ€" 400. Cell apoptosis and cell cycle assays HGC-7901cells and HFE-145 cells were seeded into 6-well plates containing Dulbecco's Modified Eagle's Medium (DMEM) with 10% FCS and cultured at 37 oC in a 5% CO2 incubator overnight. Supernatants were discarded, before c-myc McAb (1 ÃŽ ¼g/mL, 2 ÃŽ ¼g/mL, 4 ÃŽ ¼g/mL,) were added respectively and attached for 72 h. cells were fixed with pre-cooled ethanol (75%) and stained with Propidium Iodide (PI, Sigma) in the dark at room temperature for 15 min , after centrifuged at 1,000 rpm and rinses in PBS several times. The cell cycle and apoptosis rates were analyzed by FACS (Elite ESP, Beckman Coulter, Brea, CA). Statistical analyses Statistical analysis was performed using Software version SPSS11.0. All data was expressed as mean  ± SD (standard deviation). Comparisons were made by Student's t-test and comparisons of parameters were made using one-way analysis of variance among 4 groups. A value of P

John Wayne :: essays research papers

Arguably the most popular — and certainly the busiest — movie leading man in Hollywood history, John Wayne entered the film business while working as a laborer on the Fox Studios lot during summer vacations from university, which he attended on a football scholarship. He met and was befriended by John Ford, a young director who was beginning to make a name for himself in action films, comedies, and dramas. Wayne was cast in small roles in Ford's late-'20s films, occasionally under the name Duke Morrison. It was Ford who recommended Wayne to director Raoul Walsh for the male lead in the 1930 epic Western The Big Trail, it was a failure at the box office, but the movie showed Wayne's potential as a leading actor. During the next nine years, be busied himself in a multitude of B-Westerns and serials — most notably Shadow of the Eagle in between occasional bit parts in larger features such as Warner Bros.' Baby Face. But it was in action roles that Wayne excelled, e xuding a warm and imposing manliness onscreen to which both men and women could respond.   Ã‚  Ã‚  Ã‚  Ã‚  In 1939, Ford cast Wayne as the Ringo Kid in the adventure Stagecoach, a brilliant Western of modest scale but tremendous power, and the actor finally showed what he could do. Wayne nearly stole a picture filled with Oscar-caliber performances, and his career was made. He starred in most of Ford's subsequent major films, whether Westerns (Fort Apache, She Wore a Yellow Ribbon, Rio Grande, The Searchers ); war pictures (They Were Expendable); or serious dramas (The Quiet Man). He also starred in numerous movies for other directors, including several extremely popular World War II thrillers (Flying Tigers, Back to Bataan, Fighting Seabees, Sands of Iwo Jima); costume action films (Reap the Wild Wind, Wake of the Red Witch); and Westerns (Red River). His box-office popularity rose steadily through the 1940s, and by the beginning of the 1950s he'd also begun producing movies through his company Wayne-Fellowes, later Batjac, in association with his sons. Most of these films were extremely successful, and included such titles as Angel and the Badman, Island in the Sky , The High and the Mighty ( my personal favorite), and Hondo. The 1958 Western Rio Bravo, directed by Howard Hawks, proved so popular that it was remade by Hawks and Wayne twice, once as El Dorado and later as Rio Lobo.

The city of ember

The city of ember Tobacco Smoking and Alcohol Drinking Cancer of the upper respiratory and alimentary tracts claimed over 23,000 lives in 1989 and 57,000 additional cases were diagnosed. The majority of individuals who fall prey to this type of cancer are males who abuse both alcohol and tobacco. What is the risk you might ask. The fact that the risk of developing cancer of the esophagus, lip, tongue, mouth, pharynx or larynx. increases dramatically in people who are heavy users of alcohol and tobacco is substantiated by 30 years of collective research.Studies demonstrate that the risk to individuals dually addicted far utweighs the risk to Individuals who abuse only one substance. This confirmed link between alcohol and tobacco abuse and an increased risk in upper alimentary and respiratory tract cancer makes this type ot disease among the most preventable. The Correlation Between Smoking and Drinking . 1t has been observed that Individuals who drink alcohol have d greater tendency to smoke than non-drinkers. One of the first studies to establish and quantify the degree of association between drlnklng and smoking was reported In 1972.The Investigation compared 130 alcoholic men hospitalized for alcohol withdrawal to 100 non-alcoholic psychiatric utpatients, Ninety-four percent of the alcoholic men smoked one or more packs of cigarettes per day, as compared to only 46 percent of the non-alcohollcs, who smoked one or more packs per day. Another study. which compared male and female alcoholics enrolled In an army drug and alcohol rehabllltatlon program to non- alcoholic army personnel and their relatives, affirmed the smoking-drinking association.The report found that individuals who were alcoholics smoked an average of 49 cigarettes per day, but that the non-alcoholic subjects smoked only 13 cigarettes per day. In addition, the study established a high correlation between the umber of cigarettes smoked and the grams of alcohol consumed by alcoholics, as opposed to a very weak association for the non-alcoholic control group. similar report, 58 percent ot the non-drinkers were non-smokers, but the individuals who were alcoholics did not abstain from smoking.The finding that smokers who did not drink smoked significantly less than smokers who did drink was further substantiated In additional studies. Why Do Many Drinkers Smoke More? Studies released in the late 1950s, correlating heavy coffee consumption with smoking and drinking, suggested that a strong oral drive caused drinkers to smoke ore frequently. However, new evidence suggests that a strong oral drive is not the culprit. In one study, alcoholics who had successfully stopped drinking demonstrated no appreciable Increase In smoking.In tact, some even smoked less with alcohol abstinence. If a strong oral drive was responsible for the drinking-smoking association, one would expect an increase in smoking during periods of alcohol abstinence. An alternative theory claimed that drinkers smo ked more due to just as much as alcoholics who drink in the company of other people dispelled this theory. The most plausible explanation is that drinkers smoke more than non- rinkers due to a greater physiological need for nicotine. Nicotine, the main psychoactive component of tobacco, is a potent chemical.It has a stimulating effect on the nervous system, causing, among other things, increased heart rate and mental stimulation. Once addicted to nicotine, a person may experience tremors of shakiness as blood levels of nicotine decrease to critically low levels. The smoker will crave another cigarette as blood levels reach this threshold to avoid these uncomfortable symptoms. Alcohol apparently causes blood levels of nicotine to fall more rapidly in smokers by activating enzymes in tissues which metabolize drugs. For example, rats pretreated with ethanol cleared nicotine from their blood more rapidly than rats not receiving ethanol.This research, coupled with numerous independent ob servations, strongly suggests that drinkers must smoke more in order to maintain the blood nicotine levels upon which they have become dependent. Why Is There More Cancer Among Alcohol and Tobacco Users? Investigations are under way to find an answer to this question. Laboratory studies have shown that alcohol enhances the metabolism of several tobacco associated carcinogens, including nitrosamines. It is known that tobacco and its smoke contain many classes f chemical carcinogens which must be activated to react with DNA and initiate steps towards carcinogenesis.Important in this activation process are cytochrome P-450 enzymes, which are induced by alcohol in heavy drinkers. Thus, alcohol and smoking are synergistic in increasing cancer risk. Since alcohol increases the metabolism and hence the need for nicotine, it follows that the success of smoking cessation programs will be improved if drinking habits of patients are controlled. Treatment of incipient alcoholism thus becomes a prerequisite for the ultimate success of behavior modification aimed at the elimination of smoking. The City of Ember The City of Ember is a post apocalyptic fantasy about Ember. I was written by Jeanne DuPrau and published in 2003. Ember is a city which was built by people, in the book know as â€Å"The Builders†, they built this city underground to house its citizens for 200 years. They say that the earth is uninhabitable for those years but never specify why. During these years a box with instructions is passed from mayor to mayor but a plague is spreading and the seventh mayor thinks the box may contain a cure so he tries opening it but dies before it is opened. The box was never returned and it is currently missing. It is now year 241 and the towns recourses are dwindling down. The power source is also not doing well because of the generators age it is not producing enough power. Lina and Doon are two graduates of their school and are both assigned jobs they don't like so they decide to switch. When She finds the box and it has the letter in which the escape route is stated. She does not know and before she can find out her sister chews it until their are hole in it. Lina and Doon eventually make a run for it after unraveling the letters meaning. They are amazed to find a whole new world outside of the small world they lived in. When they eventually reach safety in their newly discovered world they throw the directions down to the city they lived in. The book leaves off with Mrs. Murdo, Lina's guardian finding it and it is a mystery from then on. Overall I enjoyed the book because it was suspense filled and all the action that went on made it fun to read. The ending even had suspense and i would definitely recommend this book to others as a fun read but I stress it is not a challenging one. The city of ember The city of ember Tobacco Smoking and Alcohol Drinking Cancer of the upper respiratory and alimentary tracts claimed over 23,000 lives in 1989 and 57,000 additional cases were diagnosed. The majority of individuals who fall prey to this type of cancer are males who abuse both alcohol and tobacco. What is the risk you might ask. The fact that the risk of developing cancer of the esophagus, lip, tongue, mouth, pharynx or larynx. increases dramatically in people who are heavy users of alcohol and tobacco is substantiated by 30 years of collective research.Studies demonstrate that the risk to individuals dually addicted far utweighs the risk to Individuals who abuse only one substance. This confirmed link between alcohol and tobacco abuse and an increased risk in upper alimentary and respiratory tract cancer makes this type ot disease among the most preventable. The Correlation Between Smoking and Drinking . 1t has been observed that Individuals who drink alcohol have d greater tendency to smoke than non-drinkers. One of the first studies to establish and quantify the degree of association between drlnklng and smoking was reported In 1972.The Investigation compared 130 alcoholic men hospitalized for alcohol withdrawal to 100 non-alcoholic psychiatric utpatients, Ninety-four percent of the alcoholic men smoked one or more packs of cigarettes per day, as compared to only 46 percent of the non-alcohollcs, who smoked one or more packs per day. Another study. which compared male and female alcoholics enrolled In an army drug and alcohol rehabllltatlon program to non- alcoholic army personnel and their relatives, affirmed the smoking-drinking association.The report found that individuals who were alcoholics smoked an average of 49 cigarettes per day, but that the non-alcoholic subjects smoked only 13 cigarettes per day. In addition, the study established a high correlation between the umber of cigarettes smoked and the grams of alcohol consumed by alcoholics, as opposed to a very weak association for the non-alcoholic control group. similar report, 58 percent ot the non-drinkers were non-smokers, but the individuals who were alcoholics did not abstain from smoking.The finding that smokers who did not drink smoked significantly less than smokers who did drink was further substantiated In additional studies. Why Do Many Drinkers Smoke More? Studies released in the late 1950s, correlating heavy coffee consumption with smoking and drinking, suggested that a strong oral drive caused drinkers to smoke ore frequently. However, new evidence suggests that a strong oral drive is not the culprit. In one study, alcoholics who had successfully stopped drinking demonstrated no appreciable Increase In smoking.In tact, some even smoked less with alcohol abstinence. If a strong oral drive was responsible for the drinking-smoking association, one would expect an increase in smoking during periods of alcohol abstinence. An alternative theory claimed that drinkers smo ked more due to just as much as alcoholics who drink in the company of other people dispelled this theory. The most plausible explanation is that drinkers smoke more than non- rinkers due to a greater physiological need for nicotine. Nicotine, the main psychoactive component of tobacco, is a potent chemical.It has a stimulating effect on the nervous system, causing, among other things, increased heart rate and mental stimulation. Once addicted to nicotine, a person may experience tremors of shakiness as blood levels of nicotine decrease to critically low levels. The smoker will crave another cigarette as blood levels reach this threshold to avoid these uncomfortable symptoms. Alcohol apparently causes blood levels of nicotine to fall more rapidly in smokers by activating enzymes in tissues which metabolize drugs. For example, rats pretreated with ethanol cleared nicotine from their blood more rapidly than rats not receiving ethanol.This research, coupled with numerous independent ob servations, strongly suggests that drinkers must smoke more in order to maintain the blood nicotine levels upon which they have become dependent. Why Is There More Cancer Among Alcohol and Tobacco Users? Investigations are under way to find an answer to this question. Laboratory studies have shown that alcohol enhances the metabolism of several tobacco associated carcinogens, including nitrosamines. It is known that tobacco and its smoke contain many classes f chemical carcinogens which must be activated to react with DNA and initiate steps towards carcinogenesis.Important in this activation process are cytochrome P-450 enzymes, which are induced by alcohol in heavy drinkers. Thus, alcohol and smoking are synergistic in increasing cancer risk. Since alcohol increases the metabolism and hence the need for nicotine, it follows that the success of smoking cessation programs will be improved if drinking habits of patients are controlled. Treatment of incipient alcoholism thus becomes a prerequisite for the ultimate success of behavior modification aimed at the elimination of smoking.

Irish Mythology History and Legacy

Irish mythology is a collection of pre-Christian beliefs detailing the histories and legends of ancient Ireland. These beliefs include descriptions and stories of deities, heroes, and kings measured in four distinct, chronological cycles.   Key Takeaways Irish mythology is a branch of Celtic mythology detailing the legends and histories of ancient Ireland.  It includes four distinct chronological cycles: Mythological, Ulster, Fenian, and Historical.  Ã‚  The oldest of these, the Mythological Cycle, details the supernatural first inhabitants of Ireland, known as the Tuatha Dà © Dannan.  These myths and legends were recorded by Christian monks in the 11th century, and many ancient Irish deities influenced the later canonization of Catholic saints, including St. Patrick and St. Brigid. Irish tales were recorded by 11th-century Christian monks, which helped make Irish mythology the most well-preserved branch of Celtic mythology. In some parts of Ireland, there is still a belief in the Creideamh Sà ­, or fairy faith, that coexists with Catholicism. What Is Irish Mythology? Irish mythology is a branch of Celtic mythology which details the origin stories and deities, kings, and heroes of ancient Ireland. Celtic mythology encompasses the collections of Brittonic, Scottish, and Irish ancient beliefs and practices passed down by oral tradition. Among these, Irish mythology is the best preserved, owing to the Christian monks that entered the tales into the written historical record during the Middle Ages. Ancient Irish myths are measured into four cycles. Each cycle details a group of pre-Christian deities, legendary heroes, or ancient kings, and the four cycles together chronologize the fabled settlement of the Emerald Isle. Mythological Cycle: The first Irish mythological cycle details the arrival and disappearance of the first inhabitants of Ireland, a group of godlike or supernatural people called Tuatha Dà © Dannan. The disappearance of these people gave rise to the Aos Sà ­, more contemporary mythical Irish creatures including leprechauns, changelings, and the Banshee.  Ulster Cycle: The second cycle is thought to have taken place in the 1st century, around the time of the birth of Jesus Christ. It details quests and feats of ancient heroes, specifically in the areas of Ulster, in the north, and Leinster, in the east.  Fenian Cycle: The third cycle recounts the journey of the hero Fionn mac Cumhaill and his mighty warriors, known as the Fianna.  Historical Cycle: The final Irish mythological cycle, known as the Cycle of the Kings, is the history and genealogy of ancient Irish royals as told by court poets. For centuries, Irish folklore passed through generations by oral tradition, though by the 11th century, they had been written down by monks. As a result, threads of Christianity are present in stories that would have had no notion of Christian faith. For example, the Mythological Cycle refers to the first settlers of Ireland as supernatural, godlike, or skilled in magic but never as gods, deities, or holy entities, though they would have been sacred to ancient people. Irish Mythical Deities   Ancient Irish mythological characters include venerated kings, heroes, and gods. The first cycle of Irish mythology, aptly known as the Mythological Cycle, is comprised of stories outlining the fabled founding of Ireland by the Tuatha Dà © Dannan and, later, the Aos Sà ­. The Tuatha Dà © Dannan disappeared, giving rise to the Aos Sà ­, who existed in a parallel universe alongside venerated ancestors, ancient kings, and legendary heroes. This universe, called the Tir na nOg or the Otherworld, can be accessed on certain occasions at sacred places, including burial mounds, fairy hills, stone circles, and cairns.   Tuatha Dà © Dannan According to legend, the Tuatha Dà © Dannan, or â€Å"People of the goddess Danu,† were supernatural creatures with human forms that were skilled in magical arts. Their story is recorded in the Book of Invasions, one of the texts written by the 11th-century monks. The Book of Invasions detailed how the godlike people descended into Ireland with a thick fog that encompassed the land, and when the fog lifted, the Tuatha Dà © Dannan remained. When the Milesians, the ancient ancestors of the Irish people, arrived in Ireland, they conquered the land, and the Tuatha Dà © Dannan disappeared. Some legends say they left Ireland completely and permanently, retreating to the Otherworld, while others say they blended together with the Milesians, passing some of the magic of the mythical deities into lives of the modern Irish people. Some of the most venerated figures of the Tuatha Dà © Dannan include: Dagda: God of life and death, patriarchLir: God of the sea  Ogma: God of learning, creator of Ogham scriptLugh: God of sun and light  Brighid: goddess of health and fertility  Tree de Dana: Gods of crafts; Goibniu, the blacksmith, Credne, the goldsmith, and Luchtaine, the carpenter Aos Sà ­ The Aos Sà ­, also known as the Sidhe (pronounced sith), are the â€Å"People of the Mounds† or the â€Å"Otherworldly Folk,† the contemporary depictions of the fairy folk. They are widely considered to be the descendants or manifestations of the Tuatha Dà © Dannan who retreated the Otherworld, where they walk amongst human beings but generally tend to live separately from them. The common and contemporary Irish characterizations are rooted in the Aos Sà ­. Some of the most recognizable fairies are:   Leprechaun: A solitary shoemaker known for causing mischief and keeping pots of gold.The Banshee: Similar to the Latin American myth of La Llorona, the Banshee is a woman whose wailing signifies death.  Changelings: A fairy child left in the place of a human child. Sick or disabled babies and children were often thought to be changelings, leading to devastating consequences until as recently as 1895, when Bridget Cleary was killed by her husband, who believed her to be a changeling. The Aos Sà ­ are known to inhabit places from which the Otherworld is accessible, including fairy hills, fairy rings, and notable geographical features like lakes, rivers, hills, and mountains. The Aos Sà ­ are fiercely protective of their spaces, and they are known to seek vengeance on those who enter, intentionally or not. Though the Aos Sà ­ are mythical creatures, there is a strong sense of the Creideamh Sà ­, or Fairy Faith, cultivated by some Irish people. The purpose of Creideamh Sà ­, which coexists with Catholicism, is not necessarily worship, but rather the fostering of good relations. Followers of the Fairy Faith are conscious of sacred spaces, careful not to enter them or build over them.   Christian Influence on Irish Mythology The Christian monks and scholars who recorded ancient Irish myths did so with the bias of faith. As a result, Christian development and ancient mythology significantly influenced each other. For example, Ireland’s two patron saints, St. Patrick and St. Brigid, are rooted in ancient Irish mythology. St. Patrick The most glaring amalgamation of religious practices can be found in the annual celebration of St. Patrick’s Day, a holiday with Catholic roots that almost always features leprechauns in some capacity. Contemporary holidays aside, early Christians in Ireland revered  St. Patrick as a symbol of the triumph of Christianity over paganism. However, particularly in the same medieval texts that outline ancient Irish history,  St. Patrick is not documented as a warrior, but rather as a mediator between Christian and Pagan cultures.   St. Brigid Most people who are familiar with Ireland recognize St. Brigid of Kildare as the second patron saint of the Emerald Isle, as well as the saint of a handful of other stations and vocations, including babies, midwives, Irish nuns, dairymaids. It is less commonly known that the story of St. Brigid is rooted in the legend of Brighid, one of the deities of the ancient Tuatha Dà © Dannan. Brigid was the daughter of Dagda and the goddess of fertility and health, much like St. Brigid. Sources   Bartlett, Thomas. Ireland: a History. Cambridge University Press, 2011.Bradley, Ian C. Celtic Christianity: Making Myths and Chasing Dreams. Edinburgh U.P, 2003.Croker, Thomas Crofton. Fairy Legends and Traditions of the South of Ireland. Murray (U. A.), 1825.Evans-Wentz, W. Y. The Fairy-Faith in Celtic Countries. Pantianos Classics, 2018.Gantz, Jeffrey. Early Irish Myths and Sagas. Penguin Books, 1988.Joyce, P. W. A Social History of Ancient Ireland. Longmans, 1920.Koch, John Thomas. Celtic Culture: A Historical Encyclopedia. ABC-CLIO, 2006.MacKillop, James. Myths and Legends of the Celts. Penguin, 2006.Wilde, Lady Francesca Speranza. Ancient Legends, Mystic Charms, and Superstitions of Ireland: with Sketches of the Irish Past. Ticknor and Co., 1887.