[신간의 별자리x] 우리/미술, 그리고 ‘슬픔의 박물관’

Transfemoral intraluminal graft implantation for abdominal aortic aneurysms

2014 ESC Guidelines on the diagnosis and treatment of aortic diseases: Document covering acute and chronic aortic diseases of the thoracic and abdominal aorta of the adult. The Task Force for the Diagnosis and Treatment of Aortic Diseases of the European Society of Cardiology (ESC).

▪ Abstract The synthesis and excretion of bile acids comprise the major pathway of cholesterol catabolism in mammals. Synthesis provides a direct means of converting cholesterol, which is both hydrophobic and insoluble, into a water-soluble and readily excreted molecule, the bile acid. The biosynthetic steps that accomplish this transformation also confer detergent properties to the bile acid, which are exploited by the body to facilitate the secretion of cholesterol from the liver. This role in the elimination of cholesterol is counterbalanced by the ability of bile acids to solubilize dietary cholesterol and essential nutrients and to promote their delivery to the liver. The synthesis of a full complement of bile acids requires 17 enzymes. The expression of selected enzymes in the pathway is tightly regulated by nuclear hormone receptors and other transcription factors, which ensure a constant supply of bile acids in an ever changing metabolic environment. Inherited mutations that impair bile acid synth...

The Enzymes, Regulation, and Genetics of Bile Acid Synthesis

X-ray photoelectron spectroscopic studies of iron oxides

https://www.jvascsurg.org/article/S0741-5214(95)70227-X/pdf

Ruptured thoracic aortic aneurysms: A study of incidence and mortality rates ☆ ☆☆ ★ ★★ ♢

The effect of biliary drainage on incorporation of acetate into cholesterol and on four different enzyme systems in the metabolic pathway from cholesterol to taurocholic acid has been studied in homogenates of rat liver. In homogenates of liver taken from bile fistula rats 48 hours after operation the extent of incorporation of acetate into cholesterol was about eighteen times greater and the extent of 7α-hydroxylation of cholesterol about eight times greater than in homogenates of liver from control rats. The other reactions studied, the conversion of cholest-5-ene-3β,7α-diol to 7α-hydroxycholest-4-en-3-one, the 12α-hydroxylation of 7α-hydroxycholest-4-en-3-one, and the 7α-hydroxylation of taurodeoxycholic acid, were influenced much less by biliary drainage. It is suggested that the hydroxylation of cholesterol to cholest-5-ene-3β, 7α-diol might be a rate-determining step in the conversion of cholesterol to bile acids.

https://febs.onlinelibrary.wiley.com/doi/pdf/10.1111/j.1432-1033.1967.tb00103.x

Effect of Biliary Drainage on Individual Reactions in the Conversion of Cholesterol to Taurocholic Acid

Survival in patients with abdominal aortic aneurysms. Comparison between operative and nonoperative management.

The oxidation of 5β-cholestane-3α, 7α, 12α-triol by different subcellular fractions of rat liver homogenate was studied. The most efficient oxidation was observed with the microsomal fraction fortified with the 100000 ×g supernatant fluid. Efficient oxidation occurred also with the microsomal fraction fortified with NADPH. The main products were identified as a number of cholestanetetrols. 5β-Cholestane-3α, 7α, 12α,25-tetrol and 5β-cholestane-3α, 7α, 12α, 26-tetrol accounted for about 60% of the cholestanetetrols. The oxidation of 5β-cholestane-3α, 7α, 12α-triol by the microsomal fraction fortified with NADPH was stimulated about five-fold by administration of phenobarbital. Phenobarbital treatment stimulated hydroxylations at C-23, C-24 and C-25 to a much greater extent than that at C-26. Carbon monoxide inhibited all the side-chain hydroxylations and the most marked inhibition was observed for the 26-hydroxylation.



5β-Cholestane-3α, 7α, 12α, 26-tetrol was found to be a much more efficient precursor of cholic acid than either 5β-cholestane-3α, 7α, 12α, 25-tetrol or the two C-24 epimers of 5β-cholestane-3α, 7α, 12α, 24-tetrol.

https://febs.onlinelibrary.wiley.com/doi/pdf/10.1111/j.1432-1033.1970.tb01091.x

Oxidation of 5β‐Cholestane‐3α, 7α, 12α‐triol by Rat Liver Microsomes

The first step in the degradation of the steroid side chain during biosynthesis of bile acids from cholesterol in man was studied in microsomal and mitochondrial fraction of homogenate of livers from 14 patients. The microsomal fraction was found to catalyze an efficient 25-hydroxylation of 5,8-cholestane-3a,7a,12atriol. A small extent of 23-, 24-, and 26-hydroxylation of the same substrate was observed. 53-Cholestane-3a,7adiol was hydroxylated in the 25-position only to a very small extent. The mitochondrial fraction was found to catalyze 26-hydroxylation of cholesterol, 5-cholestene-3P,7a-diol, 5P-cholestane-3a,7a-diol, 7a-hydroxy-4-cholesten-3-one, and 5,0-cholestane-3a,7a,12a-triol. Addition of Mg++ stimulated the 26-hydroxylation of cholesterol but had no effect or an inhibitory effect on 26-hydroxylation of the other substrates, indicating a heterogeneity of the mitochondrial 26-hydroxylating system. The level of 26-hydroxylase activity towards different substrates varied considerably with different mitochondrial preparations. The roles of the microsomal and mitochondrial 26- hydroxylations as well as the microsomal 25-hydroxylation in biosynthesis of bile acids in man are discussed. The results indicate that microsomal 26-hydroxylation is less important than mitochondrial 26-hydroxylation under normal conditions. The possibility that microsomal 25-hydroxylation is important cannot be ruled out.

/pdf/biosynthesis-of-bile-acids-in-man-hydroxylation-of-the-c27-4naw6i6y3x.pdf

Gunnar Johansson

Papers

Ruptured thoracic aortic aneurysms: A study of incidence and mortality rates ☆ ☆☆ ★ ★★ ♢

Effect of Biliary Drainage on Individual Reactions in the Conversion of Cholesterol to Taurocholic Acid

Survival in patients with abdominal aortic aneurysms. Comparison between operative and nonoperative management.

Oxidation of 5β‐Cholestane‐3α, 7α, 12α‐triol by Rat Liver Microsomes

Biosynthesis of bile acids in man. Hydroxylation of the C27-steroid side chain.