Spleen in the context of "Typhoid fever"

Melancholia or melancholy (Ancient Greek: μελαγχολία, romanized: melancholía; from μέλαινα χολή, mélaina cholḗ, 'black bile') is a concept found throughout ancient, medieval, and premodern medicine in Europe that describes a condition characterized by markedly depressed mood, bodily complaints, and sometimes hallucinations and delusions. Besides a pathological condition, melancholy could also refer to a mood or temperament and at times it was even used as a description of the human condition in general.

Melancholy (or more precisely the 'black bile', from which melancholy derives its name) was regarded as one of the four temperaments matching the four humours. Until the 18th century, doctors and other scholars classified melancholic conditions as such by their perceived common cause – an excess of a notional fluid known as "black bile", which was commonly linked to the spleen. Hippocrates and other ancient physicians described melancholia as a distinct disease with mental and physical symptoms, including persistent fears and despondencies, poor appetite, abulia, sleeplessness, irritability, and agitation. Later, fixed delusions were added by Galen and other physicians to the list of symptoms. In the Middle Ages, the understanding of melancholia shifted to a religious perspective, with sadness seen as a vice and demonic possession, rather than somatic causes, as a potential cause of the disease.

Typhoid fever, also known as typhoid, is a disease caused by Salmonella enterica serotype Typhi bacteria, also called Salmonella typhi. Symptoms vary from mild to severe, and usually begin six to 30 days after exposure. Often there is a gradual onset of a high fever over several days. This is commonly accompanied by weakness, abdominal pain, constipation, headaches, and mild vomiting. Some people develop a skin rash with rose colored spots. In severe cases, people may experience confusion. Without treatment, symptoms may last weeks or months. Diarrhea may be severe, but is uncommon. Other people may carry it without being affected, but are still contagious. Typhoid fever is a type of enteric fever, along with paratyphoid fever. Salmonella enterica Typhi is believed to infect and replicate only within humans.

Typhoid is caused by the bacterium Salmonella enterica subsp. enterica serovar Typhi growing in the intestines, Peyer's patches, mesenteric lymph nodes, spleen, liver, gallbladder, bone marrow and blood. Typhoid is spread by eating or drinking food or water contaminated with the feces of an infected person. Risk factors include limited access to clean drinking water and poor sanitation. Those who have not yet been exposed to it and ingest contaminated drinking water or food are most at risk for developing symptoms. Only humans can be infected; there are no known animal reservoirs. Salmonella typhi which causes typhoid fever is different from the other Salmonella bacteria that usually cause salmonellosis, a common type of food poisoning.

Gnathostomata (/ˌnæθoʊˈstɒmətə/; from Ancient Greek: γνάθος (gnathos) 'jaw' + στόμα (stoma) 'mouth') are jawed vertebrates. Gnathostome diversity comprises roughly 60,000 species, which accounts for 99% of all extant vertebrates, including all living bony fishes (both ray-finned and lobe-finned, including their terrestrial tetrapod relatives) and cartilaginous fishes, as well as extinct prehistoric fish such as placoderms and acanthodians. Most gnathostomes have retained ancestral traits like true teeth, a stomach, and paired appendages (pectoral and pelvic fins, limbs, wings, etc.). Other traits are elastin, horizontal semicircular canal of the inner ear, myelinated neurons, and an adaptive immune system which has discrete lymphoid organs (spleen and thymus) and uses V(D)J recombination to create antigen recognition sites, rather than using genetic recombination in the variable lymphocyte receptor gene.

It is now assumed that Gnathostomata evolved from ancestors that already possessed two pairs of paired fins. Until recently these ancestors, known as antiarchs, were thought to have lacked pectoral or pelvic fins. In addition to this, some placoderms were shown to have a third pair of paired appendages, that had been modified to claspers in males and pelvic basal plates in females — a pattern not seen in any other vertebrate group. The jawless Osteostraci are generally considered the closest sister taxon of Gnathostomata.

Hematopathology or hemopathology (both also spelled haem-, see spelling differences) is the study of diseases and disorders affecting and found in blood cells, their production, and any organs and tissues involved in hematopoiesis, such as bone marrow, the spleen, and the thymus. Diagnoses and treatment of diseases such as leukemia and lymphoma often deal with hematopathology; techniques and technologies include flow cytometry studies and immunohistochemistry.

In the United States, hematopathology is a board-certified subspecialty by the American Board of Pathology. Board-eligible or board-certified hematopathologists are usually pathology residents (anatomic, clinical, or combined) who have completed hematopathology fellowship training after their pathology residency. The hematopathology fellowship lasts either one or two years. A physician who practices hematopathology is called a hematopathologist.

A splenectomy is the surgical procedure that partially or completely removes the spleen. The spleen is an important organ in regard to immunological function due to its ability to efficiently destroy encapsulated bacteria. Therefore, removal of the spleen runs the risk of overwhelming post-splenectomy infection, a medical emergency and rapidly fatal disease caused by the inability of the body's immune system to properly fight infection following splenectomy or asplenia.

Common indications for splenectomy include trauma, tumors, splenomegaly or for hematological disease such as sickle cell anemia or thalassemia.

Uracil (/ˈjʊərəsɪl/) (symbol U or Ura) is one of the four nucleotide bases in the nucleic acid RNA. The others are adenine (A), cytosine (C), and guanine (G). In RNA, uracil binds to adenine via two hydrogen bonds. In DNA, the uracil nucleobase is replaced by thymine (T). Uracil is a demethylated form of thymine.

Uracil is a common and naturally occurring pyrimidine derivative. The name "uracil" was coined in 1885 by the German chemist Robert Behrend, who was attempting to synthesize derivatives of uric acid. Originally discovered in 1900 by Alberto Ascoli, it was isolated by hydrolysis of yeast nuclein; it was also found in bovine thymus and spleen, herring sperm, and wheat germ. It is a planar, unsaturated compound that has the ability to absorb light.

Infectious mononucleosis (IM, mono), also known as glandular fever, is an infection usually caused by the Epstein–Barr virus (EBV). Most people are infected by the virus as children, when the disease produces few or no symptoms. In young adults, the disease often results in fever, sore throat, enlarged lymph nodes in the neck, and fatigue. Most people recover in two to four weeks; however, feeling tired may last for months. The liver or spleen may also become swollen, and in less than one percent of cases splenic rupture may occur.

While usually caused by the Epstein–Barr virus, also known as human herpesvirus 4, which is a member of the herpesvirus family, a few other viruses and the protozoon Toxoplasma gondii may also cause the disease. It is primarily spread through saliva but can rarely be spread through semen or blood. Spread may occur by objects such as drinking glasses or toothbrushes, or through a cough or sneeze. Those who are infected can spread the disease weeks before symptoms develop. Mono is primarily diagnosed based on the symptoms and can be confirmed with blood tests for specific antibodies. Another typical finding is increased blood lymphocytes of which more than 10% are reactive. The monospot test is not recommended for general use due to poor accuracy.