Autoxidation of methyl linoleate. Separation and analysis of isomeric mixtures of methyl linoleate hydroperoxides and methyl hydroxylinoleates

The mixture of conjugated diene hyperperoxide isomers obtained from autoxidation of methyl linoleate was separated by high performance liquid chromatography (HPLC). Four major isomers were obtained from adsorption chromatography and identified as the 9 and 13 positional isomers having the trans-trans and cis-trans configurations. The latter geometrical isomers have the trans double bond adjacent to the hydroperoxide group. The hydroxy compounds (methyl hydroxylinoleates) obtained from the hydroperoxides by NaBH4 reduction were similarly separated but with improved resolution. This is the first instance of the complete separation of these compounds and provides a rapid method for their analysis. Unlike adsorption chromatography, reversed-phase chromatography separates the mixtures only according to the geometrical isomerism of the double bonds and not according to the position of the hydroxy or hydroperoxide function.     

Spigelian hernia

Spigelian hernia is very rare. Together with the direct inguinal hernia which emerges between the inferior epigastric artery and the edge of the rectus muscle, it is more frequent. Congenital openings in the aponeurosis of the transverse muscle permit the hernia either above or under the inferior epigastric artery. Due to neglect of this type of hernia and absence of herniation, the diagnosis can be difficult. Complaints are often uncharacteristic. Surgical intervention is indicated.     

Sterilization of the operating microscope

Sterilization of the operating microscope and its equipment with formaldehyde (10 g for 10 hours) in a specially developed container provides sterility and ideal storage, and secures immediate availability in daily operating theatre practice.     

Differences in tissue fatty acids and cholesterol of swine from different genetic backgrounds

A review of 1,000 consecutive coronary angiograms, most of them performed for evaluation of angina pectoris, yielded 9 examples of congenital anomalies of the coronary arteries. In 2 cases the angina may have been due to malposition of the left coronary artery or one of its branches. There were 2 cases of aberrant origin of the circumflex artery from the right coronary artery, 2 cases of aberrant left anterior descending artery, 3 cases in which all three major coronary branches arose from the right aortic sinus, and 2 cases of coronary artery fistulas. Malposition of the coronary artery should be considered as a possible cause of angina.