Creative Diagnostics
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Creative Diagnostics is a leading manufacturer and supplier of antibodies, viral antigens, innovative diagnostic components, and critical assay reagents.
Stories (15/0)
Why the Desired Effect is not Achieved After Using AAV?
Adeno-associated virus (AAV) is a small non-enveloped virus, belonging to the family Parvoviridae. It was first discovered in 1965 from contaminants of adenovirus isolates. It has an icosahedral structure on the outside and a diameter of about 26 nm. Its capsid protein is composed of It is composed of three proteins: VP1, VP2 and VP3. The genome of AAV is a single-stranded linear DNA, approximately 4700 bp, including two upstream and downstream open reading frames (ORFs): Rep and Cap. They are located between 2 T-shaped inverted terminal repeats (ITRs) each consisting of 145 nucleotides. The role of ITR is to serve as the origin of viral replication and packaging signal. The Rep gene is involvedin viral replication and integration, encoding viral replication proteins, and the Cap gene is responsible for encoding the three viral capsid proteins. The natural wild-type adeno-associated virus that exists in nature has Rep and Cap genes on its genome, while the experimental AAV vector is an artificially modified plasmid based on wild adeno-associated virus and does not have Rep and Cap genes on its genome. Therefore, also called recombinant adeno-associated virus (rAAV). Unless otherwise specified, the abbreviation AAV generally refers to the modified AAV vector.
By Creative Diagnostics11 days ago in Humans
What is Procalcitonin (PCT)?
Procalcitonin (PCT) is the propeptide of calcitonin. The production of procalcitonin during infection and sepsis does not depend on calcitonin levels, but is closely related to the release of endotoxin and inflammatory mediators in bacterial infection. Traditional biological markers, clinical symptoms, and signs lack sufficient sensitivity and specificity to guide treatment decisions for infectious diseases. As a recently applied biomarker, procalcitonin is increasingly supported by increasing evidence that detecting serum procalcitonin concentration can be used to early diagnose the type of infectious pathogen, evaluate the severity of infection, guide medication, and determine prognosis. Procalcitonin has become the most useful biomarker in the management of infection and sepsis in most parts of the world.
By Creative Diagnostics11 days ago in Humans
Research on the Biological Effects of GLP-2
GLP-2 (glucagon-likepeptide-2) was discovered and named by the Lilly Laboratory in the United States when cloning the proglucagon gene (PG). In 1996, Drucker et al. discovered that the active ingredient in proglucagon-derived peptide (PGDP) that promotes intestinal mucosal growth is GLP-2. Its effect is stronger than other growth factors that have been discovered, and its growth-promoting effect is organ-specific (limited to the stomach and intestine), GLP-2 began to be valued and studied. Subsequent animal experiments and human studies have shown that the main function of GLP-2 is to stimulate the proliferation of intestinal mucosal crypt cells and inhibit their apoptosis, thereby promoting the growth of intestinal mucosa and regeneration and repair after injury.GLP-2 can also inhibit the secretion of gastric acid and motility, increase the blood supply of intestine, improve the barrier function of the intestine, and promote the absorption of nutrients in the intestine.
By Creative Diagnosticsabout a month ago in Education
Research on Genetically Engineered Drug Host Cell Proteins
Genetically engineered drugs are introduced into host cells such as Escherichia coli, yeast or mammalian cells through recombinant technology to construct engineering strains or cell strains, and then undergo specific expression, assembly, folding and post-translational modification processes to produce drugs with corresponding Bioactive macromolecules. Endogenous proteins derived from host cells are called host cell proteins (HCPs). Their composition is complex. Depending on the selected host cells and production processes, the isoelectric point (3-11), hydrophobicity, relative the molecular mass (generally 5000~250000) distribution varies significantly.
By Creative Diagnosticsabout a month ago in Humans
Staphylococcus Aureus Enterotoxin B Detection Method
Staphylococcus aureus (S. aureus) is an important class of food-borne pathogens that cause food contamination and food poisoning, and is also a symbiont of human skin and mucous membranes. Studies have found that about 20%~30 % of healthy individuals carry Staphylococcus aureus. Animal foods are susceptible to Staphylococcus aureus infection, such as milk, butter, cured ham, etc. Food poisoning incidents caused by Staphylococcus aureus have been frequently reported, and more than 95% of them are caused by enterotoxin. According to reports, the United States and Canada accounted for 33% and 45% of food poisoning incidents caused by staphylococcal enterotoxins (SEs), respectively. Epidemiological studies have shown that Staphylococcus aureus enterotoxin A can be produced under more suitable environmental conditions (temperature 7~47, pH 4℃~10) and growth phase (logarithmic growth phase or transition to stable phase) Staphylococcal enterotoxin A(SEA), Staphylococcal enterotoxin B (SEB), Staphylococcal enterotoxin C1 (SEC1), Staphylococcal enterotoxin D (SED) and other about 23 serotypes, they are similar in structure and function with molecular weight of 27.5~30 kDa. Among the above-mentioned SEs, SEB is one of the most common biotoxins reported so far, and it is also a typical biotoxin that causes food poisoning. In order to detect SEB, researchers have developed different detection methods, among which the main detection methods are biological methods, immunological methods, gene probe methods, instrumental analysis methods and biosensing methods.
By Creative Diagnostics3 months ago in Humans
What is Herpes Simplex Virus
Herpes simplex virus (HSV) belongs to the herpesvirus alpha subfamily and has a unique 4-layer structure. The core of HSV is a linear double-stranded DNA of about 152 000 bp, surrounded by an icosahedral capsid. The outer capsid is a membrane, which contains more than 20 important proteins that can regulate the virus replication cycle. It is a characteristic structure of herpes viruses, can connect the capsid and envelope to form a complete virus particle. The outermost layer of HSV is the lipid bilayer envelope, which contains at least 12 viral membrane proteins (gB, gC, gD, gE, gG, gH, gI, gJ, gK, gL, gM, gN). Entry into host cells and viral immune evasion are both critical.
By Creative Diagnostics4 months ago in Humans
B Cell Differentiation
What Are B Cells? B cells, also known as B lymphocytes, develop from hematopoietic precursor cells which play a central role in the immune-pathogenesis of glomerulonephritides and transplant rejection. B cells can secrete antibodies through multiple mechanisms and their antibodies are the central elements of humoral immunity which against an almost unlimited variety of pathogens. In addition to that, B cells contribute to disease pathogenesis by providing costimulation and cytokines to T cells. B cells also play an immunomodulatory role in regulating the immune response by secreting cytokines that inhibit disease onset and progression. B cell–targeted approaches for treating immune diseases of the kidney and other organs have gained significant momentum. However, much remains to be understood about B cell biology in order to determine the timing, duration, and context of optimal therapeutic response to B cell–targeted approaches.
By Creative Diagnostics5 months ago in Humans
Blood-brain Barrier Permeability
The blood-brain barrier is a barrier system in which the capillary endothelial cells in the brain are closely connected to each other while interacting with surrounding pericytes and astrocytes. It precisely controls the exchange of substances between blood and brain tissue, which is essential for maintaining the stability of the microenvironment in the brain. Studies show that the cells that make up the blood-brain barrier regulate the development and function of the blood-brain barrier by expressing tight and adherent connexins, transporters, and related signaling molecules. In addition, neurons and microglia are also involved in the regulation of the blood-brain barrier under physiological and pathological conditions. Recent studies have shown that the occurrence and development of various neurological diseases are accompanied by the destruction of the structure and function of the blood-brain barrier. Therefore, the study of the blood-brain barrier will deepen the understanding of neuro-vascular interactions and provides an important theoretical basis for the diagnosis and treatment of neurological diseases.
By Creative Diagnostics6 months ago in Education
DNA Modifying Enzymes
Introduction of DNA Modifying Enzymes DNA stores the genetic information on which organisms depend for survival and reproduction. The integrity of DNA molecules is critical to cellular function. So the DNA of human organism cells is constantly damaged by various external factors (such as ultraviolet light, electric radiation, chemical poisons, Figure 1) and endogenous factors (such as free radicals produced by metabolic intermediates). Cells can occur 104 times damages in a day. If the damage cannot be repaired in time, it will lead to apoptosis, uncontrolled cell growth, genetic variation and malignant tumors. For example, excessive exposure of human skin to strong sunlight can easily contribute to skin cancer. Mammalian DNA repair methods include direct repair (DR), mismatch repair (MMR), base excision repair (BER), nucleotide excision repair (NER), and double strand break repair (DSBR) including homologous recombination (HR) and non-homologous end joining (NHEJ).
By Creative Diagnostics6 months ago in Education
An Overview of PD-1/PD-L
In recent years, monoclonal antibody therapy against immunological checkpoints has made breakthroughs in cancer treatment, especially in the treatment of various tumors such as melanoma, lung cancer, kidney cancer and bladder cancer. The mechanism of action is briefly described below. In cell immune, the immune response of T cells is regulated by complex inhibitory signals (also known as “immunization checkpoints”) to prevent uncontrolled immune responses or even autoimmune diseases. Among them, programmed death molecule 1 (PD-1) plays an important role in immunization checkpoints. PD-1 is expressed on the surface of T cells and belongs to the co-inhibitory molecule, playing a similar role as a “brake” in the immune system. The ligand for PD-1 includes PD-1 ligand (PD-L1) and PD-L2. PD-L1 is mainly induced on immune cells (such as tumor infiltrating lymphocytes) and epithelial cells (such as tumor cells), while PD-L2 is expressed only on APC cells. This means that PD-1 ligand PD-L1 is expressed on both tumor cells and tumor infiltrating lymphocytes, but not on antigen-presenting cells. Therefore, PD-1/PD-L1 inhibits T cell activation mainly in the tumors micro environment.
By Creative Diagnostics10 months ago in Education
What is Hippocampus?
The hippocampus is one of the most studied parts of the brain (the cerebral cortex) in the central nervous system of mammals. Because the shape is similar to the hippocampus, it is called the hippocampus. In the human brain, the hippocampus is mainly responsible for learning and memory. The short-term memory in daily life is stored in the hippocampus. If a memory segment, such as a phone number or a person is repeatedly mentioned in a short time, the hippocampus will be transferred to the cerebral cortex and become a permanent memory.
By Creative Diagnostics10 months ago in Writers
Influenza A: Unraveling the Mystery of H1N1 and H3N2
Influenza A viruses, the culprits of respiratory illness in humans, are a complex and multifaceted group of viruses. Among the numerous subtypes of Influenza A, H1N1 and H3N2 with a notorious history of causing seasonal epidemics and pandemics, demand special attention.
By Creative Diagnostics11 months ago in Humans
