Silver proteinate

Last updated November 13, 2019

Silver proteinate (brand name: Protargol) is used in electron microscopy with periodic acid and thiocarbohydrazide or thiosemicarbohydrazide as a positive stain for carbohydrates such as glycogen. It can also be used for light microscopy to stain nerve tissue. It is normally available as 8% silver in combination with albumin.^[1]

Periodic acid ( "per-i-OH-dic") is the highest oxoacid of iodine, in which the iodine exists in oxidation state VII. Like all periodates it can exist in two forms: orthoperiodic acid, with the chemical formula H₅IO₆ and metaperiodic acid, which has the formula HIO₄.

Thiocarbohydrazide is a toxic compound made by the reaction of carbon disulfide with hydrazine (hydrazinolysis). It is used in the silver proteinate specific staining of carbohydrates in electron microscopy.

Albumin is a family of globular proteins, the most common of which are the serum albumins. All the proteins of the albumin family are water-soluble, moderately soluble in concentrated salt solutions, and experience heat denaturation. Albumins are commonly found in blood plasma and differ from other blood proteins in that they are not glycosylated. Substances containing albumins, such as egg white, are called albuminoids.

Because of its bactericidal properties it was used to treat gonorrhea before the discovery of antibiotics. The inventor of the first silver protein formulation was Arthur Eichengrün, a German chemist working for Bayer. It was introduced for therapeutic use in 1897.^[2]^[3]

Gonorrhea, colloquially known as the clap, is a sexually transmitted infection (STI) caused by the bacterium Neisseria gonorrhoeae. Infection may involve the genitals, mouth, and/or rectum. Infected men may experience pain or burning with urination, discharge from the penis, or testicular pain. Infected women may experience burning with urination, vaginal discharge, vaginal bleeding between periods, or pelvic pain. Complications in women include pelvic inflammatory disease and in men include inflammation of the epididymis. Many of those infected, however, have no symptoms. If untreated, gonorrhea can spread to joints or heart valves.

An antibiotic is a type of antimicrobial substance active against bacteria and is the most important type of antibacterial agent for fighting bacterial infections. Antibiotic medications are widely used in the treatment and prevention of such infections. They may either kill or inhibit the growth of bacteria. A limited number of antibiotics also possess antiprotozoal activity. Antibiotics are not effective against viruses such as the common cold or influenza; drugs which inhibit viruses are termed antiviral drugs or antivirals rather than antibiotics.

Arthur Eichengrün was a German Jewish chemist, materials scientist, and inventor. He is known for developing the highly successful anti-gonorrhea drug Protargol, the standard treatment for 50 years until the adoption of antibiotics, and for his pioneering contributions in plastics: co-developing the first soluble cellulose acetate materials in 1903, called "Cellit", and creating processes for the manufacture of these materials which were influential in the development of injection moulding. During World War I his relatively non-flammable synthetic cellulose acetate lacquers, marketed under the name "Cellon", were important in the aircraft industry. He contributed to photochemistry by inventing the first process for the production and development of cellulose acetate film, which he patented with Becker.

Related Research Articles

Histology, also known as microscopic anatomy or microanatomy, is the branch of biology which studies the microscopic anatomy of biological tissues. Histology is the microscopic counterpart to gross anatomy, which looks at larger structures visible without a microscope. Although one may divide microscopic anatomy into organology, the study of organs, histology, the study of tissues, and cytology, the study of cells, modern usage places these topics under the field of histology. In medicine, histopathology is the branch of histology that includes the microscopic identification and study of diseased tissue. In the field of paleontology, the term paleohistology refers to the histology of fossil organisms.

Silver nitrate is an inorganic compound with chemical formula AgNO^₃. This compound is a versatile precursor to many other silver compounds, such as those used in photography. It is far less sensitive to light than the halides. It was once called lunar caustic because silver was called luna by the ancient alchemists, who believed that silver was associated with the moon.

Staining is a technique used to enhance contrast in samples, generally at the microscopic level. Stains and dyes are frequently used in histology and in the medical fields of histopathology, hematology, and cytopathology that focus on the study and diagnoses disease at a microscopic level. Stains may be used to define biological tissues, cell populations, or organelles within individual cells.

Felix Hoffmann was a German chemist notable for re-synthesizing diamorphine, which was popularized under the Bayer trade name of "heroin". He is also credited with synthesizing aspirin, though whether he did this under his own initiative or under the instruction of Arthur Eichengrün is contested.

Histopathology refers to the microscopic examination of tissue in order to study the manifestations of disease. Specifically, in clinical medicine, histopathology refers to the examination of a biopsy or surgical specimen by a pathologist, after the specimen has been processed and histological sections have been placed onto glass slides. In contrast, cytopathology examines free cells or tissue micro-fragments.

Giemsa stain, named after German chemist and bacteriologist Gustav Giemsa, is used in cytogenetics and for the histopathological diagnosis of malaria and other parasites.

A fluorescence microscope is an optical microscope that uses fluorescence and phosphorescence instead of, or in addition to, scattering, reflection, and attenuation or absorption, to study the properties of organic or inorganic substances. "Fluorescence microscope" refers to any microscope that uses fluorescence to generate an image, whether it is a more simple set up like an epifluorescence microscope or a more complicated design such as a confocal microscope, which uses optical sectioning to get better resolution of the fluorescence image.

Heinrich Dreser was a German chemist responsible for the aspirin and heroin projects at Bayer AG. He was also a key figure in creating the widely used modern drug codeine.

Jenner's Stain is used in microscopy for staining blood smears. The stain is dark blue and results in very observable clearly stained nuclei.

Crystal violet or gentian violet is a triarylmethane dye used as a histological stain and in Gram's method of classifying bacteria. Crystal violet has antibacterial, antifungal, and anthelmintic properties and was formerly important as a topical antiseptic. The medical use of the dye has been largely superseded by more modern drugs, although it is still listed by the World Health Organization.

Reticular fibers, reticular fibres or reticulin is a type of fiber in connective tissue composed of type III collagen secreted by reticular cells. Reticular fibers crosslink to form a fine meshwork (reticulin). This network acts as a supporting mesh in soft tissues such as liver, bone marrow, and the tissues and organs of the lymphatic system.

Negative staining is an established method, often used in diagnostic microscopy, for contrasting a thin specimen with an optically opaque fluid. In this technique, the background is stained, leaving the actual specimen untouched, and thus visible. This contrasts with 'positive staining', in which the actual specimen is stained.

Gustav Giemsa was a German chemist and bacteriologist who was a native of Medar-Blechhammer. He is remembered for creating a dye solution commonly known as "Giemsa stain". This dye is used for the histopathological diagnosis of malaria and parasites such as Plasmodium, Trypanosoma, and Chlamydia.

Bright-field microscopy is the simplest of all the optical microscopy illumination techniques. Sample illumination is transmitted white light, and contrast in the sample is caused by attenuation of the transmitted light in dense areas of the sample. Bright-field microscopy is the simplest of a range of techniques used for illumination of samples in light microscopes, and its simplicity makes it a popular technique. The typical appearance of a bright-field microscopy image is a dark sample on a bright background, hence the name.

The history of aspirin begins with its synthesis and manufacture in 1899. Before that, salicylic acid had been used medicinally since antiquity. Medicines made from willow and other salicylate-rich plants appear in clay tablets from ancient Sumer as well as the Ebers Papyrus from ancient Egypt. Hippocrates referred to their use of salicylic tea to reduce fevers around 400 BC, and were part of the pharmacopoeia of Western medicine in classical antiquity and the Middle Ages. Willow bark extract became recognized for its specific effects on fever, pain and inflammation in the mid-eighteenth century. By the nineteenth century pharmacists were experimenting with and prescribing a variety of chemicals related to salicin, the active component of willow extract.

Immunogold labeling or Immunogold staining (IGS) is a staining technique used in electron microscopy. This staining technique follow the same patterns of the Indirect immunofluorescence: colloidal gold particles are most often attached to secondary antibodies which are in turn attached to primary antibodies designed to bind a specific antigen or other cell component. Gold is used for its high electron density which increases electron scatter to give high contrast 'dark spots'.

Events in the year 1949 in the Allied-occupied Germany, then in West Germany and East Germany.

References

↑ Silver proteinate at Sigma-Aldrich
↑ Vaupel, E. (2005), Arthur Eichengrün—Tribute to a Forgotten Chemist, Entrepreneur, and German Jew Angew. Chem. Int. Ed., 44: 3344–3355. doi: 10.1002/anie.200462959
↑ State Medical Examining and Licensing Boards A Handbook of Useful Drugs: Protargol 1913 Press Of The American Medical Association (hosted on: chestofbooks.com)

This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.

[1] Silver proteinate at Sigma-Aldrich

[2] Vaupel, E. (2005), Arthur Eichengrün—Tribute to a Forgotten Chemist, Entrepreneur, and German Jew Angew. Chem. Int. Ed., 44: 3344–3355. doi: 10.1002/anie.200462959

[3] State Medical Examining and Licensing Boards A Handbook of Useful Drugs: Protargol 1913 Press Of The American Medical Association (hosted on: chestofbooks.com)

Silver proteinate

See also

Related Research Articles

References