CENH3 is a centromere-specific histone H3 variant and has been used as a marker to identify active centromeres and DNA sequences associated with functional centromere/kinetochore complexes. In this study, up to four distinct CENH3 (BrCENH3) cDNAs were identified in individuals of each of three diploid species of Brassica. Comparison of the BrCENH3 cDNAs implied three related gene families: BrCENH3-A in Brassica rapa (AA), BrCENH3-B in B. nigra (BB), and BrCENH3-C in B. oleracea (CC). Each family encoded a histone fold domain and N-terminal histone tails that vary in length in all three families. The BrCENH3-B cDNAs have a deletion of two exons relative to BrCENH3-A and BrCENH3-C, consistent with the more ancient divergence of the BB genome. Chromatin immunoprecipitation and immunolabeling tests with anti-BrCENH3 antibodies indicated that both centromeric tandem repeats and the centromere-specific retrotransposons of Brassica are directly associated with BrCENH3 proteins. In three allotetraploid species, we find either co-transcription of the BrCENH3 genes of the ancestral diploid species or gene suppression of the BrCENH3 from one ancestor. Although B genome centromeres are occupied by BrCENH3-B in the ancestral species B. nigra, in allotetraploids both BrCENH3-A and BrCENH3-C proteins appear to assemble at these centromeres.

Antibodies are naturally produced by plasma cells within the human body to mediate an adaptive immune response against invading pathogens. There are five predominant antibodies produced, each specialized to execute certain functions. Antibodies gain the ability to identify a diverse range of antigens by genetic recombination of different elements of its structure and while the affinity for a specific antigen derives from affinity maturation and somatic recombination processes. Antibodies have a plethora of clinical applications, the most important being their use in combating autoimmune conditions and cancer, conferring passive immunity, and their diagnostic applications.

Antiglobulin testing, also known as the Coombs test, is an immunology laboratory procedure used to detect the presence of antibodies against circulating red blood cells (RBCs) in the body, which then induce hemolysis. The destruction of these red blood cells (RBCs) by antibodies directed against them is described diagnostically as autoimmune hemolytic anemia (AIHA). Many etiologies fall under this classification. Antiglobulin testing can be either direct antiglobulin testing (DAT) or indirect antiglobulin testing (IAT). The principle of DAT is to detect for the presence of antibodies attached directly to the RBCs, which takes place by washing a collected blood sample in saline to isolate the patient’s RBCs; this procedure removes unbound antibodies that may otherwise confound the result. IAT, by contrast, is used to detect unbound antibodies to RBCs, which may be present in the patient’s serum. With direct antiglobulin testing, a monospecific or polyspecific reagent is then added to the washed RBCs to detect bound IgG and/or complement C3. In practice, many laboratories will first use the polyspecific reagent that can detect for both IgG and C3; a positive result will then be followed with monospecific testing to characterize the antibody further.[1] For indirect antiglobulin testing, serum from a blood sample gets isolated, and native RBCs removed. The isolated serum sample then gets incubated with foreign RBCs of known antigenicity. Antiglobulin reagent is then added, and the presence of agglutination indicates a positive result.

Psoriatic arthritis (PsA) is chronic inflammatory arthritis associated with psoriasis (PsO) and found in about 20 to 30% of such patients.[1] It shares many clinical features with other spondyloarthropathies and also rheumatoid arthritis (RA). It is usually seronegative, but a small percentage of patients may be positive for rheumatoid factor (RF) and anti-cyclic citrullinated peptide antibodies (anti-CCP antibodies). The clinical manifestations are varied and can change over time, evolving from one articular pattern to another. There is a considerable financial and psychological burden associated with this disease. There has been significant progress recently in understanding the disease pathogenesis, which has translated into new therapies.

The term 'lupus anticoagulant' is a misnomer as it is neither only found in lupus, nor is it mainly associated with bleeding. The term LA was first coined to describe the phenomenon of plasma samples from patients with systemic lupus erythematosus (SLE) that failed to clot within an appropriate time.[1] Lupus anticoagulant (LA) is one the of antiphospholipid antibodies, which also include anticardiolipin (aCL) antibody and anti-beta2-glycoprotein (GP) I antibodies. LA are heterogenous autoantibodies, predominantly IgG, and IgM isotypes that specifically target the phospholipid-protein component of the cell membrane. LA interferes and prolongs clotting process, which is a risk factor for arterial and/or venous thrombosis with complications such as stroke, transient ischemic strokes, acquired thrombophilia, and pregnancy loss. Furthermore, LAs may be transitory in the setting of certain medications or infections and thus have also present in asymptomatic patients.[2] Testing for LAs is essential in patients with hypercoagulable states and antiphospholipid syndromes.[3]

The complement system consists of several complement proteins synthesized by the liver’s Kupffer cells and subsequently found in the body’s blood and tissues. The proteins themselves are both zymogens, meaning they are typically inactive, and are meta-stable when activated, meaning they require a cell surface to remain active. When these complement proteins (mostly named C1 to C9) initiate a cascade that engages both the innate and adaptive immune system, they serve as the first line of defense in response to pathogen attack. One goal of the complement system is the formation of a membrane attack complex (MAC) which compromises the pathogen’s cell wall, causing swelling that ultimately leads to cell death. The complement system is diffusely active within the body and deficiencies or dysregulation results in immune system deficiencies, autoimmune disorders, or bleeding disorders. While often considered as part of the innate immune system, this is not entirely the case. One method of complement cascade initiation, the classical activation pathway, involves antibodies and thus the adaptive immune system. The other two well-studied pathways are the alternative and lectin activation pathways. Neither requires adaptive immune system activation and therefore, truly are mechanisms of the innate immune system. Although they differ in mechanisms, the commonly needed step of all pathways is the conversion of C3 to C3a and C3b; the latter is necessary for the formation of the MAC.

Definition of gastritis has its basis in histological features of the gastric mucosa. It is not erythema observed during gastroscopy, and there are no specific clinical presentations or symptoms defining it. The current classification of gastritis centers on time course (acute versus chronic), histological features, anatomic distribution, and underlying pathological mechanisms. Acute gastritis will evolve to chronic, if not treated. Helicobacter pylori (H. pylori) is the most common cause of gastritis worldwide. However, 60 to 70% of H. pylori-negative subjects with functional dyspepsia or non-erosive gastroesophageal reflux were also found to have gastritis. H. pylori-negative gastritis is a consideration when an individual fulfill all four of these criteria (i) A negative triple staining of gastric mucosal biopsies (hematoxylin and eosin, Alcian blue stain and a modified silver stain), (ii) A negative H pylori culture, (iii) A negative IgG H. pylori serology, and (iv) No self-reported history of H. pylori treatment. In these patients, the cause of gastritis may relate to tobacco smoking, consumption of alcohol, and/or the use of non-steroidal anti-inflammatory drugs (NSAIDs) or steroids. Other causes of gastritis include: 1. Autoimmune gastritis associated with serum anti-parietal and anti-intrinsic factor antibodies; characterized by chronic atrophic gastritis limited to the corpus and fundus of the stomach that is causing marked diffuse atrophy of parietal and chief cells. 2. Gastritis causes include organisms other than H. pylori such as Mycobacterium avium intracellulare, Herpes simplex, and Cytomegalovirus. 3. Gastritis caused by acid reflux. Rare causes of gastritis include collagenous gastritis, sarcoidosis, eosinophilic gastritis, and lymphocytic gastritis. Clinical presentation, laboratory investigations, gastroscopy, as well as the histological and microbiological examination of tissue biopsies are essential for the diagnosis of gastritis and its causes. Treatment of H. pylori-associated gastritis results in the rapid disappearance of polymorphonuclear infiltration and a reduction of chronic inflammatory infiltrate with the gradual normalization of the mucosa. Mucosal atrophy and metaplastic changes may resolve shortly, but it is not necessarily the outcome of treatment of H. pylori in all treated patients. Other types of gastritis should be treated based on their causative etiology.