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PubMed1991

Cloning, sequencing, and expression of pyrophosphate-dependent phosphofructokinase from Propionibacterium freudenreichii.

Pyrophosphate-dependent 6-phosphofructo-1-kinase (PPi-PFK) from Propionibacterium freudenreichii is a non-allosteric enzyme with properties dissimilar to those of other described phosphofructokinases. The enzyme was cloned into pBluescript, sequenced, and expressed in Escherichia coli at levels 15 times higher than those observed in Propionibacterium. The gene consists of 1215 bases which code for a protein of 404 amino acids and a mass of 43,243 daltons. High G + C in the codon usage (66%) of the gene is consistent with the classification of Propionibacterium in the High-G + C subdivision of the Gram-positive bacteria. While showing no sequence identity to the non-allosteric ATP-dependent phosphofructokinase of E. coli, alignments of the amino acid sequence with other PFKs reveal degrees of identities among the amino halves of the proteins, from 26% between the Propionibacterium and potato PPi-PFKs, and 29% between Propionibacterium and E. coli ATP-PFKs. These levels of identities indicate that the amino halves of these proteins are homologous. Identities between the carboxyl half of Propionibacterium PFK and carboxyl halves of other sequences are below 20%, suggesting that the carboxyl half is not homologous. Despite the poor conservation, most of the residues that take part in the binding of fructose-6-P or Mg-PPi could be readily identified by analogy to the structure of the E. coli PFK. Both the fructose-6-P and ATP-binding sites are conserved, indicating that PPi binds to the homologous site of the E. coli ATP-binding site.

Adenosine Triphosphate↗
PubMed1975

[Diagnostic value of bone scintigraphy with technetium pyrophosphate. Study of 250 patients].

The authors report the results they obtained by bone scintigraphy using technetium pyrophosphate. In a study of 142 patients with cancer, the authors show, as others have done, that bone scintigraphy makes it possible to find bone metastases that are radiologically undetectable and they emphasize the importance of this discovery. In 7 patients with spondylodiscitis, of whom 1 was without radiological signs at the time the scintigraphy was carried out, the authors always observed localized vertebral hyperfixation and they noted that this examination can be valuable for distinguishing spondylodiscitis from pseudo-Pott's discarthroses and from the lesions of vertebral epiphysitis, which in their experience do not result in isotopic hyperfixation. In 7 patients with epiphyseal osteonecrosis, the authors observed isotopic hyperfixation before the appearance of radiological signs. In 12 patients with osteoporosis, the authors observed hyperfixation in bone in certain compressed vertebrae, whereas other vertebrae that had probably been compressed some considerable time earlier did not fix the isotope excessively. They never observed hyperfixation in vertebrae that were not compressed. Among 5 patients with ankylosing spondylitis with radiological signs of sacro-iliac arthritis, the authors observed sacro-iliac hyperfixation in only 3 cases. Two other patients who had signs indicating ankylosing spondylarthritis, but were without radiological signs of sacro-iliac arthritis did not show sacro-iliac hyperfixation of the isotope. Among 7 patients with Paget's disease, the authors observed hyperfixation in all the bones with radiological signs of disease; in addition, in 3 patients, there was also hyperfixation in certain bones that were radiologically clear.

Bone Diseases↗
PubMed1975

Radioisotopic detection of osseius metastases. Evaluation of 99mTc polyphosphate and 99mTc pyrophosphate.

A total of 146 patients were investigated for the presence of osseous metastases with 99mTc polyphosphate or 99mTc pyrophosphate bone scans. Results of bone imaging were retrospectively compared to roentgenographic results surveying similar anatomic areas in 128 patients. This comparison revealed that roentgenographic interpretations were in error in 19% of the cases. Thirty-three patients had bone scans and roentgenograms that were in agreement and considered abnormal, but in more than one third of these cases the patients had multiple abnormalities that were shown by the bone scan but were not recognized roentgenographically. In consideration of the low toxicity, ready availability, economy, shortened procedure time, and low radiation dose associated with the use of these new bone-seeking agents, it is concluded that they are superior to roentgenograms and previously utilized radionuclides for early detection of osseous metastases.

Bone Neoplasms↗
PubMed1991

The effect of an anticalculus dentifrice on calculus formation and gingival recession in Thai children and teenagers: one-year study. Study #1. An anticalculus dentifrice containing 3.3% soluble pyrophosphate and 1.0% of a copolymer.

A one-year, double-blind clinical study was conducted on a population of Thai children and teenagers to determine the effect of the twice daily use of an anticalculus dentifrice on supragingival calculus formation and gingival recession, as compared to the use of a placebo dentifrice and the continuation of customary oral hygiene procedures. The subjects were initially evaluated for calculus using the Volpe-Manhold procedure and for gingival recession using the GRT procedure of Volpe, Triratana, and Rustogi. All subjects received an oral prophylaxis and were assigned to the use of 1) a placebo dentifrice containing 0.243% sodium fluoride in a silica base, 2) an anticalculus dentifrice containing 3.3% soluble pyrophosphate and 1.0% Gantrez copolymer--in a 0.243% sodium fluoride/silica base, or 3) continuation of customary oral hygiene procedures. After one year, the subjects using the anticalculus dentifrice had 37.01% less supragingival calculus and 25.09% less gingival recession than the subjects using the placebo dentifrice. Additionally, after one year, the subjects using the anticalculus dentifrice had 34.86% less supragingival calculus and 29.95% less gingival recession than the subjects who continued their customary oral hygiene procedures. All reductions were statistically significant at the 95% or greater level of confidence.

Adolescent↗
PubMed1991

The effect of an anticalculus dentifrice on calculus formation and gingival recession in Thai children and teenagers: one-year study. Study #2. An anticalculus dentifrice containing 1.3% soluble pyrophosphate and 1.5% of a copolymer.

A one-year, double-blind clinical study was conducted on a population of Thai children and teenagers to determine the effect of the twice daily use of an anticalculus dentifrice on supragingival calculus formation and gingival recession, as compared to the use of a placebo dentifrice and the continuation of customary oral hygiene procedures. The subjects were initially evaluated for calculus using the Volpe-Manhold procedure and for gingival recession using the GRT procedure of Volpe, Triratana, and Rustogi. All subjects received an oral prophylaxis and were assigned to the use of the following: (1) a placebo dentifrice containing 0.243% sodium fluoride in a silica base, (2) an anticalculus dentifrice containing 1.3% soluble pyrophosphate and 1.5% Gantrez copolymer in a 0.243% sodium fluoride/silica base, or (3) continuation of customary oral hygiene procedures. After six months, the subjects using the anticalculus dentifrice had 35.93% less supragingival calculus than the placebo dentifrice subjects, and 52.74% less supragingival calculus than the subjects who continued their regular/customary oral hygiene procedures. After one year, the subjects using the anticalculus dentifrice had 39.76% less supragingival calculus and 18.33% less gingival recession than the subjects using the placebo dentifrice. Also, after one year, the subjects using the anticalculus dentifrice had 57.86% less supragingival calculus and 16.55% less gingival recession than the subjects who continued their customary oral hygiene procedures. All reductions were statistically significant at the 99% level of confidence.

Adolescent↗
PubMed1975

[Value and limitatious of scintigraphy of the sacro-iliac joints using technetium pyrophosphate].

Scintigraphic exploration of the sacroiliac (S.I.) joints by 99 m-technetium pyrophosphate is simple and free of all danger. The fixation of the isotope in the right sacroiliac (R.S.I.) and the "normal" limits of the fixation ratios R.S.I./L.R. and the lumbar rachis (L.R.), visible on the same film. A series of 28 controls having made it possible to calculate the "normal" limits of the fixation ratios R.S.I./L.R. and L.S.I./L.R., the isotopic fixation was measured in 25 patients with sacroiliac inflammation, 21 of whom were rheumatic, 3 infectious. It was shown that scintigraphy could yield useful information on the evolution of sacroiliac inflammation, making an early diagnosis possible, and also contributing to differentiation between rheumatic and infectious inflammation.

Adult↗
PubMed1991

An ORF323 with homology to crtE, specifying prephytoene pyrophosphate dehydrogenase, is encoded by cyanelle DNA in the eukaryotic alga Cyanophora paradoxa.

Carotenoids are essential constituents of the light-harvesting and light-protective systems of photosynthetic organisms. The biochemistry of carotenoid biosynthesis in eukaryotes is known, whereas evidence for the genes specifying this biosynthetic pathway is scant. We report here the nucleotide sequence and expression of a gene likely encoding crtE (prephytoene pyrophosphate dehydrogenase). The reaction product of this enzyme is phytoene, a C40 carotenoid precursor common to all organisms. The gene is found in the cyanelle (plastid) DNA of an eukaryotic alga, Cyanophora paradoxa. The expression into protein of cyanelle crtE has been demonstrated in vitro. The identity and similarity scores of CrtE from cyanelles with the corresponding protein from the photosynthetic bacterium Rhodobacter capsulatus are 28.6 and 68.5%, respectively.

Alkyl and Aryl Transferases↗
PubMed1975

A phlogistic function of PGE1 in calcium pyrophosphate dihydrate crystal-induced inflammation.

Promotion of calcium pyrophosphate dihydrate (CaPPD) crystal-induced inflammation by prostaglandin (PG) E1 has been demonstrated by two new techniques: (1) Rats deficient in essential fatty acids, biological precursors of PG, developed less footpad swelling than did normal rats following injections of unheated CaPPD. Addition of one ng of PGE1 to these crystals resulted in normal swelling. (2) This phlogistic effect of PGE1 was also demonstrated in normal rats fed a normal dietwho received injections of CaPPD crystals heated to 200 degrees C for three hours. The heated crystals induced less footpad swelling than did unheated crystals. When one ng of PGE1 was added to the suspensions of heated crystals the resultant swelling approximated that obtained by unheated crystals. The possible role of PGE1 in mediating CaPPD crystal-induced inflammation is suggested. An analysis of urate and CaPPD crytal-induced inflammation is presented with comments setting forth the concept that these metabolic crystal disorders are membrane diseases.

Animals↗
PubMed1976

Measurement of acute myocardial infarcts in dogs with 99mTc-stannous pyrophosphate scintigrams.

Myocardial scintigrams using 99mTc-stannous pyrophosphate (99mTc-PYP) can be used to measure myocardial infarcts produced in dogs by proximal ligation of the left anterior descending coronary artery. Seven dogs had 99mTc-PYP myocardial scintigraphy performed 24--32 hr after ligation of the proximal left anterior artery. In each dog the scintigrams showed increased 99mTc-PYP uptake in the distribution of the artery. The scintigraphically visible areas of infarction, measured using interactive computer-aided techniques, were compared subsequently with independent histologic measurements of myocardial infarct size. Several methods for using the area measurements to estimate infarct size were tested. The most successful method (r = 0.92, p less than 0.01) assumed a linear relationship between the largest scintigraphic infarct area and the histologically determined infarct weight. The results suggest that 99mTc-PYP myocardial scintigrams provide a useful noninvasive method for measuring infarct size in dogs with proximal ligation of the left anterior descending coronary artery.

Animals↗
PubMed1976

Ovarian carcinoma imaged by 99mTc-pyrophosphate: case report.

An ovarian carcinoma which avidly accumulated 99mTc-pyrophosphate was imaged during a bone scan. The primary tumor and its implants over the liver surface were both visualized. Although imaging of such an ovarian malignancy has not been previously reported, it offers a potential method for assessing neoplastic size and spread.

Adult↗
PubMed1976

6-phosphofructokinase (pyrophosphate). Properties of the enzyme from Entamoeba histolytica and its reaction mechanism.

The inorganic pyrophosphate-requiring 6-phosphofructokinase of Entamoeba histolytica has been further investigated. The molecular weight of the enzyme is approximately 83,000 and its isoelectric point occurs at pH 5.8 to 6.0. The divalent cation requirement for reaction was explored. In the direction of fructose 6-phosphate formation half-maximal rate required 500 muM magnesium ion; in the direction of fructose bisphosphate formation 8 muM magnesium ion sufficed. ATP, PPi, polyphosphate, acetyl phosphate, or carbamyl phosphate cannot replace PPi as phosphate donor for the conversion of fructose 6-phosphate to fructose bisphosphate. In the direction of fructose 6-phosphate formation arsenate can replace orthophosphate. Isotope exchange studies indicate that little or no exchange occurs between Pi and PPi or between fructose 6-phosphate and fructose bisphosphate in the absence of a third substrate. These findings appear to rule out phosphoenzyme formation and a ping-pong reaction mechanism. PPi, Pi, and fructose bisphosphate are competitive inhibitors of fructose bisphosphate, PPi, and fructose 6-phosphate, respectively. This argues against an ordered mechanism and suggests a random mechanism. Fructose 6-phosphate and Pi were noncompetitive with respect to each other indicating the formation of a dead end complex. These product inhibition relationships are in accord with a Random Bi Bi mechanism.

Diphosphates↗
PubMed1976

Acute myocardial infarction imaged with 99mTc-stannous pyrophosphate and 201Tl: a clinical evaluation.

Twenty-six patients suspected of having acute myocardial infarction (AMI) underwent myocardial scintigraphy sequentially with 201Tl and 99mTc-stannous pyrophosphate (99mTc-PPi). Of the 26 patients, 24 had AMI documented by enzyme and electrocardiographic changes. Nineteen had transmural and five had subendocardial myocardial infarctions. The remaining two patients had "unstable angina pectoris." The mean time from onset to imaging was 4 days. Of the 24 patients with AMI, 22 had positive 99mTc-PPi scintigrams. In 20 the area of acute myocardial damage appeared to be the same by 99mTc-PPi scintigram as by ECG; in two, the location could not be precisely determined. The two patients with negative 99mTc-PPi scintigrams at the time of combined myocardial imaging had had positive 99mTc-PPi images previously. In all 24 patients, the 201Tl images were abnormal in at least the location suggested by the electrocardiogram. In seven patients, the area of decreased 201Tl activity was grossly equal to the positive area on the 99mTc-PPi images; in 15, the 201Tl defect was definitely larger; and in two, the 201Tl defect appeared slightly smaller. Although the 99mTc-PPi and 201Tl myocardial images provide different information, both are valuable in determining the overall integrity of the myocardium in patients with ischemic heart disease.

Acute Disease↗
PubMed1976

99mTc-pyrophosphate scan and radiographic correlation in thyroid acropachy: case report.

A case of thyroid acropachy secondary to Graves' disease is described. Radiographic abnormalities were found to correlate with those in a 99mTc-pyrophosphate bone scan. Abnormal tracer concentrations were observed in the diaphyses of the metacarpals and phalanges of both hands and also in regions of pretibial myxedema. The differential diagnosis of the scan abnormalities is discussed.

Adult↗
PubMed1976

Abnormal 99mTechnetium-tin-pyrophosphate bone scans in chronic renal failure.

A high incidence of abnormal 99mTechnetium-tin-pyrophosphate (99mTcPPi) is reported in a population of chronic renal failure patients. Using the 5 hour bone to soft tissue ratio as a quantitative index of increased uptake, 78% of 45 long-term dialysis patients and a similar proportion of non-dialyzed chronic renal failure patients were found to have increased uptakes. In animal studies using a uremic model, similar increased uptakes of 99mTcPPi was found with evidence of increased vascularity as reflected by red cell or plasma volumes in the bone or by the uptake of concomitantly administered 45Ca. The evidence suggests that the abnormal bone scans reflect abnormalities in collagen metabolism that occurs in the uremic state and that 99mTcPPi scans are useful in the diagnosis and management of renal osteodystrophy.

Animals↗
PubMed1976

Myocardial scintigraphy with technetium 99m pyrophosphate.

The pyrophosphate of Tc99m attaches itself to ischaemic myocardial cells, and therefore makes it possible to obtain a scintigram of necrotic or necrosing myocardium. In a series of 65 cases the scintigram was positive in every case in which there had been a recent transmural infarct (17 cases). The results showed greater variation in the other ischaemic conditions involving the myocardium (limited infarcts or simple angina). The progress as a function of time was stuided in a series of fairly recent and older infarcts. The limitations and future prospects of this investigations are discussed.

Coronary Disease↗
PubMed1977

Technetium pyrophosphate scanning in the detection of acute myocardial infarction: clinical experience.

Technetium-99m-stannous pyrophosphate (99mTc-PYP) accumulates in acutely infarcted myocardium and can be detected by scintiscanning. The clinical value of 99mTc-PYP scintiscanning was studied in 83 patients 6 hours to 21 days after the onset of acute chest pain. In 12 patients with normal electrocardiograms and serum enzyme values no uptake of 99mTc-PYP was detected on the scintigrams. Of 44 patients with electrocardiographic or enzyme evidence, or both, of acute myocardial infarction the scintigrams were positive in 31, "questionable" in 2 and negative in 11; no positive scan was obtained within 12 hours of the onset of pain, and the scans generally remained positive for up to 5 days. In 24 patients with evidence of prolonged myocardial ischemia the scans were positive in 2, questionable in 4 and negative in 18. The scans were negative in each of three patients with acute or constrictive pericarditis. Localization by electrocardiography and scintiscanning correlated nearly perfectly for transmural infarcts but subendocardial infarcts could not always be localized precisely by scintiscanning. The infarct area (total area of 99mTc-PYP uptake) correlated well with the peak serum value of creatine phosphokinase.

Angina Pectoris↗
PubMed1977

Aortic aneurysm detected by 99mTc-pyrophosphate imaging: case report.

An example of aneurysmal concentration of 99mTc-pyrophosphate (Tc-PPi) is described. An abdominal aortic aneurysm was suspected when a rectilinear bone scan showed an abnormal paraspinal area of activity. The aneurysm was confirmed by ultrasonic examination. Conventional radiographic examination failed to reveal calcification within the aneurysm. Aneurysmal concentration of Tc-PPi should be considered in patients showing abnormal radioactivity in the region of vascular structures on radionuclide bone images.

Aged↗