Search PubMed⌕ Search

Biomedical subjects

S Lucas

Publications and source records attributed to S Lucas.

At least 163 records · Page 9Linked to original sources
PubMedDate not supplied

Millennium fat-cell lipolysis reveals unsuspected novel tracks.

Adipose tissue lipolysis, i.e., the catabolic process leading to the breakdown of triglycerides into fatty acids and glycerol, is often considered as a simple and well-understood metabolic pathway. However, progress on the hormonal regulation and molecular mechanism of fat-cell lipolysis is opening new avenues and points to a number of unanswered questions. Recent studies on the lipolytic beta- and antilipolytic alpha2-adrenergic control of lipolysis has allowed a better understanding of the relative contribution of the two types of receptors and provide strong evidence for the in vivo implication of alpha2-adrenoceptors in the physiological control of subcutaneous adipose-tissue lipolysis. A novel lipolytic system has been characterized in human fat cells. Natriuretic peptides stimulate lipolysis through a cGMP-dependent pathway. The molecular details of the lipolytic reaction are not fully understood. Translocation of hormone-sensitive lipase, the rate-limiting enzyme of lipolysis, to the lipid droplet seems to be an important step during lipolytic activation. Reorganization of the lipid droplet coating by perilipins may also facilitate the access of the enzyme. Unexpectedly, hormone-sensitive lipase-deficient mice are not obese and show residual adipose-tissue lipolysis, which suggests the existence of another triglyceride lipase. Whether the expression of this uncharacterized neutral lipase is compensatory for the lack of hormone-sensitive lipase is an important question yet to be resolved. In humans, alterations of hormone-sensitive lipase expression are associated with changes in lipolysis in various physiological and pathological states. Genetic studies show that beta2-adrenoceptor and hormone-sensitive lipase genes may participate in the polygenic background of obesity.

Adipose Tissue↗
PubMedDate not supplied

Magnetic resonance imaging of the normal and diseased feline middle ear.

The magnetic resonance imaging appearance of the feline middle ear is described in three healthy cats and in five cats with middle ear disease. Owing to the good spatial resolution, multiplanar slice orientation as well as display high contrast resolution of soft tissue, in particular fluids, MR imaging was helpful prior to surgery. It is superior to radiography which failed to allow identification of the abnormality in two of our five cats. MR imaging for middle ear disease should include dorsal and transverse plane images using T1- and T2-weighted sequences. In the presence of a mass within the bulla or the external ear canal application of contrast medium is helpful.

Animals↗
PubMedDate not supplied

[The common channel syndrome associated with cystic dilatation of the common bile duct. Apropos of a case complicated by lithiasis of the common channel].

Perduodenoscopic retrograde cholangiography in a 15 year old boy with cystic dilatation of common bile duct demonstrated lithiasis of Vater's ampulla and collateral shunt for Wirsung's duct in the form of a functional Santorini duct. Cases of combined cystic dilatation of common bile and Vater's ducts reported in the literature are reviewed and a study conducted of frequency of cystic dilatation of common bile duct, its classification as described by Longmire and Hadat (enlarging that proposed by Alonso-Leij), and its diagnosis and complications. Routine retrograde cholangiography can delect lithiasis of Vater's ampulla and allow preoperative determination of therapy. Current investigatory procedures for these anomalies have allowed rediscussion of the etiopathogenicity of cystic dilatation of common bile duct and a tendency towards a duoalist hypothesis, without its definite confirmation at the present time.

Adolescent↗