The structure of exopolyphosphatase (PPX) from Porphyromonas gingivalis in complex with substrate analogs and magnesium ions reveals the basis for polyphosphate processivity

2021 ◽  
pp. 107767
Author(s):  
Zhang Aili ◽  
Zuokun Lu ◽  
Yanhao Xu ◽  
Tiantian Qi ◽  
Wenwen Li ◽  
...  
Keyword(s):  
Porphyromonas Gingivalis ◽  
Magnesium Ions ◽  
Substrate Analogs

Observations of the Thermal Decomposition of Brucite

1968 ◽  
Vol 26 ◽  
pp. 446-447
Author(s):  
P. L. Burnett ◽  
W. R. Mitchell ◽  
C. L. Houck
Keyword(s):  
Thermal Decomposition ◽  
Magnesium Oxide ◽  
Basal Plane ◽  
Magnesium Ions ◽  
A Value ◽  
Reaction Proceeds

Natural Brucite (Mg(OH)2) decomposes on heating to form magnesium oxide (MgO) having its cubic ﹛110﹜ and ﹛111﹜ planes respectively parallel to the prism and basal planes of the hexagonal brucite lattice. Although the crystal-lographic relation between the parent brucite crystal and the resulting mag-nesium oxide crystallites is well known, the exact mechanism by which the reaction proceeds is still a matter of controversy. Goodman described the decomposition as an initial shrinkage in the brucite basal plane allowing magnesium ions to shift their original sites to the required magnesium oxide positions followed by a collapse of the planes along the original <0001> direction of the brucite crystal. He noted that the (110) diffraction spots of brucite immediately shifted to the positions required for the (220) reflections of magnesium oxide. Gordon observed separate diffraction spots for the (110) brucite and (220) magnesium oxide planes. The positions of the (110) and (100) brucite never changed but only diminished in intensity while the (220) planes of magnesium shifted from a value larger than the listed ASTM d spacing to the predicted value as the decomposition progressed.

The Effect of Agents which Modify Platelet Behaviour and of Magnesium Ions on Thrombus Formation In Vivo

1979 ◽  
Vol 42 (02) ◽  
pp. 603-610 ◽  
Author(s):  
J H Adams ◽  
J R A Mitchell
Keyword(s):  
Thrombus Formation ◽  
Cerebral Arteries ◽  
Magnesium Ions ◽  
Body Formation ◽  
Inflammatory Agent ◽  
Platelet Thrombus ◽  
Magnesium Salts ◽  
Higher Doses ◽  
Do So

SummaryThe ability of potential anti-thrombotic agents to modify platelet-thrombus formation in injured cerebral arteries in the rabbit was tested. Low doses of heparin were without effect, while higher doses produced variable suppression of white body formation but at the expense of bleeding. Aspirin did not inhibit white body formation but another non-steroid anti-inflammatory agent, flurbiprofen was able to do so, as was the anti-gout agent, sulphinpyrazone. Magnesium salts both topically and parenterally, suppressed thrombus formation and increased the concentration of ADP which was required to initiate thrombus production at minor injury sites.

Daya Hambat Minyak Hati Ikan Hiu Terhadap Pertumbuhan Bakteri Porphyromonas gingivalis

DENTA ◽  
2015 ◽  
Vol 9 (2) ◽  
pp. 129
Author(s):  
Felisitas Maria Agustina ◽  
Dian Mulawarmanti ◽  
Yoifah Rizka Wedarti
Keyword(s):  
Porphyromonas Gingivalis ◽  
Control Group ◽  
Strain Atcc ◽  
Control Group Design ◽  
Group Design ◽  
Post Test

<p><strong> </strong></p><p><strong>Latar belakang : </strong><em>Porphyromonas gingivalis </em>adalah bakteri paling dominan yang ditemukan pada periodontitis kronis. Antibakteri konvensional(antibiotik), terutama tetrasiklin sering digunakan untuk menunjang terapi periodontal, akan tetapi penggunaan antibiotik sering menimbulkan resisten, alergi, dan toksik.  Minyak hati ikan hiu spesies <em>Cenctrophorus sp </em>memiliki sifat antibakteri melalui kandungannya yaitu <em>squalene </em>dan<em> squalamine, </em>sehingga memiliki potensi untuk dikembangkan sebagai terapi ajuvan pada penyakit periodontal. <strong>Tujuan : </strong>Mengetahui daya hambat minyak hati ikan hiu terhadap pertumbuhan bakteri <em>Porphyromonas gingivalis. </em><strong>Metode : </strong>Penelitian ini menggunakan rancangan penelitian <em>post test only control group design.</em> Subjek penelitian adalah bakteri <em>Porphyromonas gingivalis </em>strain ATCC 33277 sebanyak 30 sampel yang dibagi menjadi 5 kelompok. Tiga kelompok diberi minyak hati ikan hiu dengan konsentrasi 10%, 15%, dan 20%. Kontrol positif diberi tetrasiklin dan kontrol negatif diberi DMSO 1%. Daya hambat diperiksa dengan menggunakan metode difusi dan diinokulasikan pada media <em>MH </em>agar. Daya hambat dihitung dengan mengukur diameter zona jernih pada disk dengan menggunakan <em>digital callipers </em>dalam satuan milimeter. <strong>Hasil : </strong>Minyak hati ikan hiu dapat menghambat pertumbuhan bakteri <em>Porphyromonas gingivalis </em>pada setiap konsentrasi. Konsentrasi 10% (9,06 mm), konsentrasi 15% (11,31 mm), konsentrasi 20% (13,2 mm), sedangkan kontrol negatif (6,01 mm), dan  kontrol positif (30,09 mm). <strong>Simpulan : </strong>Minyak hati ikan hiu dapat menghambat pertumbuhan bakteri <em>Porphyromonas gingivalis.</em><em></em></p><p><em> </em></p>

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