Phosphotungstic Acid Method Research Articles

An electron microscopic and cytochemical study ofLeptomonas samueli

The fine structure of promastigotes ofLeptomonas samueli is described. This protozoan revealed several features in common with other trypanosomatids. A large membrane-bound cavity containing many vesicles was observed near the nucleus. Pinocytotic vesicles were seen arising from the membrane lining the flagellar pocket. They are associated with some microtubules which originate in the flagellar pocket region and extend toward the multivesicular structure. Morphometric analysis made on electron micrographs showed a mitochondrial relative volume of 0.11 and a peroxisome relative volume of 0.08. Determination of the number of sub-pellicular microtubules in different regions of the protozoon body show that the largest number is found in the region containing the Golgi complex. Carbohydrates were detected using the periodic-acid-thiosemicarbazide-silver proteinate technique. Reaction products were seen in the plasma membrane, in the membrane of the Golgi complex, and in the membranes which form the multivesicular structure. Two cytochemical methods were used to locate basic proteins. Using the ammoniacal silver method reaction products were seen only in the nucleus. With the ethanolic phosphotungstic acid method reaction products were seen in the microtubules which form the flagellum, in the peroxisome-like organelle, and at the region of adhesion of the flagellum to the cell body.

Synaptic density in human frontal cortex — Developmental changes and effects of aging

Density of synaptic profiles in layer 3 of middle frontal gyrus was quantitated in 21 normal human brains ranging from newborn to age 90 years. Synaptic profiles could be reliably demonstrated by the phosphotungstic acid method (Bloom and Aghajanian 3) in tissue fixed up to 36 h postmortem. Synaptic density was constant throughout adult life (ages 16–72 years) with a mean of 11.05 × 10 8synapses/cu.mm ± 0.41 S.E.M.. There was a slight decline in synaptic density in brains of the aged (ages 74–90 years) with a mean of 9.56 × 10 8synapses/cu.mm ± 0.28S.E.M. in 4 samples ( P < 0.05). Synaptic density in neonatal brains was already high—in the range seen in adults. However, synaptic morphology differed; immature profiles had an irregular presynaptic dense band instead of the separate presynaptic projections seen in mature synapses. Synaptic density increased during infancy, reaching a maximum at age 1–2 years which was about 50% above the adult mean. The decline in synaptic density observed between ages 2–16 years was accompanied by a slight decrease in neuronal density. Human cerebral cortex is one of a number of neuronal systems in which loss of neurons and synapses appears to occur as a late developmental event.

Laryngeal lesions in Urbach-Wiethe disease (lipoglycoproteinosis; lipoid proteinosis; hyalinosis cutis et mucosae). A histopathological and clinical study, including direct laryngoscopical examinations.

In Northern Sweden 27 patients with Urbach‐Wiethe disease (lipoglycoproteinosis, lipoid proteinosis, hyalinosis cutis et mucosae) are known. Twenty‐six of them were hoarse and one was not. According to anamnesis, the hoarseness had been present since the first years of life. Some earlier diagnoses indicate that the disease may be confused with more common disorders such as chronic laryngitis and singer's nodule. In agreement with preceding reports it was observed in 4 of our patients that the laryngeal changes in UWD may be demonstrated by tomography. In one of the Swedish patients the laryngeal symptoms necessitated a tracheostomy. The impression from a laryngoscopical study of 10 patients was that the laryngeal changes are more conspicuous in patients with more pronounced hoarseness. The hoarseness seems to be due to air‐leakage, as perfect closure of the vocal cords is impossible due to their irregular borders. A histopathological study of 7 patients showed that the vocal cords may contain abundant deposits of the substance typical for UWD and that deposits can extend throughout the whole submucous layer down to the muscular coat. The UWD deposits were stained yellow in van Gieson's and Herovici's methods and red with haematoxylin and eosin. A positive reaction was obtained with the periodic acid‐Schiff procedure and to a moderate degree also with the p‐dimethylaminobenzaldehyde reaction for tryptophan, and a negative reaction for fibrin was obtained with the phosphotungstic acid method. Unequivocally positive reactions were not obtained with the methods for amyloid. The reticulin staining procedure gave variable results. It was found that differentiation between degenerated elastin and UWD deposits may at least sometimes be difficult unless a specific method for elastin is applied.

Spurious hyperuricaemia and gout in patients treated with L-DOPA

During the course of a drug trial with L-DOPA in 38 patients, it was noted that the mean serum uric acid levels were significantly raised in the 26 males compared with a group of matched controls. The increase in serum uric acid levels in the 12 females was not significant. Serum uric acid was measured using an automated phosphotungstic acid method. Investigations showed that L-DOPA produced spuriously raised uric acid values using the above method and another automated reducing method (cupric phenanthroline), but did not significantly affect the uricase method. The effect of a 1.0g. dose of L-DOPA on serum uric acid determined by the above 3 mcthods, was investigated in 17 patients. It was found that statistically significant increases in serum uric acid were detected by phosphotungstic acid and cupric phenanthroline but not by the uricase method. In the original group of 38 patients, 4 have subsequently developed gout while receiving L-DOPA. Suggested possible causes for this phenomenon include a decrease in uric acid excretion and increased metabolism of oxy-purines.

リン-タングステン酸法による鉄鋼中バナジウムの吸光光度定量

リン-タングステン酸法による鉄鋼中バナジウムの吸光光度定量

Activity ratio of adrenaline to noradrenaline in various colour reactions.

Activity ratios of adrenaline to noradrenaline in various chemical methods, such as the permanganate, the corrosive sublimate, the iodine, the phosphotungstic acid and arsenomolybdic acid methods were estimated. The mean value (adrenaline: noradrenaline) obtained was 1.16:1 in the permanganate method, 1.31:1 in the corrosive sublimate method, 2.4:1 in the iodine method, 2.17:1 in the phosphotungstic acid method and 7.6:1 in the arsenomolybdic acid method.

A note on the colorimetric ratio of uric acid to adrenaline in the Folin, Cannon and Denis' phosphotungstic acid method.

A note on the colorimetric ratio of uric acid to adrenaline in the Folin, Cannon and Denis' phosphotungstic acid method.

THE PHOSPHOTUNGSTIC ACID METHOD

Acta Medica ScandinavicaVolume 92, Issue S84 p. 17-38 THE PHOSPHOTUNGSTIC ACID METHOD First published: January/December 1937 https://doi.org/10.1111/j.0954-6820.1937.tb02101.xCitations: 1AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onEmailFacebookTwitterLinked InRedditWechat Citing Literature Volume92, IssueS84January/December 1937Pages 17-38 RelatedInformation

Observations on the use of the phosphotungstic acid method of determining ascorbic acid in urines with low ascorbic acid content

Observations on the use of the phosphotungstic acid method of determining ascorbic acid in urines with low ascorbic acid content

Guanidine determinations on some invertebrates by a colorimetric phosphotungstic acid method

Research Article| January 01 1928 Guanidine determinations on some invertebrates by a colorimetric phosphotungstic acid method Max Mapes Ellis Max Mapes Ellis 1The Physiological Institute, University of Glasgow Search for other works by this author on: This Site PubMed Google Scholar Biochem J (1928) 22 (2): 353–361. https://doi.org/10.1042/bj0220353 Views Icon Views Article contents Figures & tables Video Audio Supplementary Data Peer Review Share Icon Share Facebook Twitter LinkedIn MailTo Cite Icon Cite Get Permissions Citation Max Mapes Ellis; Guanidine determinations on some invertebrates by a colorimetric phosphotungstic acid method. Biochem J 1 January 1928; 22 (2): 353–361. doi: https://doi.org/10.1042/bj0220353 Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentAll JournalsBiochemical Journal Search Advanced Search This content is only available as a PDF. © 1928 CAMBRIDGE UNIVERSITY PRESS1928 Article PDF first page preview Close Modal You do not currently have access to this content.

The relation of pancreatic extract to the sugar of the blood

In January, 1912, I reported preparation of pancreas which when injected intravenously into dogs that had been rendered diabetic by pancreatectomy, lowered both the output of sugar and the D/N ratio. This preparation seemed to offer a ready means of attack for several of the problems bearing on the relation of the pancreas to sugar metabolism. Possibly the simplest of these is the relation between the amount of sugar present in the blood and the abundance of the pancreatic hormone present, and this is a preliminary report of my work on this subject.Cats were killed and their blood was collected. The protein was removed and the blood was decolorized by a modification of the phosphotungstic acid method reported by Oppler. In determining the amount of sugar Munson and Walker's “Uniform method of sugar determination” was used and gave consistent results. In order to test its efficiency the method was controlled by division of a sample of blood into two portions. In one of these the glucose was estimated direc...