Synthesis and transport of lipoprotein particles by intestinal absorptive cells in man

The site of synthesis and some new details of lipoprotein particle transport have been demonstrated within the jejunal mucosa of man. In normal fasting volunteers, lipoprotein particles (88%, 150-650 A diameter) were visualized within the smooth endoplasmic reticulum and Golgi cisternae of absorptive cells covering the tips of jejunal villi. Electron microscopic observations suggested that these particles exited through the sides and bases of absorptive cells by reverse pinocytosis and then passed through the extracellular matrix of the lamina propria to enter lacteal lumina.     

A simplified procedure for the measurement of total hydroxyproline in urine

A simple method for the estimation of hydroxyproline is described. Removal of acid, salts and pigments from hydrolysed urine is achieved by passing the urine hydrolysate through a column of ion retardation resin. Oxidation and chromophore development follow directly on an aliquot of the column elutate. All the parameters of the reaction have been studied and conditions described which give the most sensitive and stable colour development. Recoveries of 97% or better are obtained with precision of replicates of ± 3%. The method is inexpensive, rapid and not subject to interference from other compounds commonly present in urine.     

Evidence for a direct effect on vascular permeability of platelet-activating factor induced hemoconcentration in the guinea pig

The ability of synthetic platelet-activating factor (PAF) given intravenously to produce loss (extravasation) of protein rich plasma (resulting in hemoconcentration) has been examined using guinea pigs. Hemoconcentration induced by PAF was not prevented by prior administration of inhibitors of thromboxane synthetase (7-(3-pyridyl)heptanoic acid, UK-37,248-01), PGI2, aspirin, indomethacin or antiserum induced thrombocytopenia. Calcium channel blockers (nifedipine, verapamil, diethylamino octyltrimethoxybenzoate, diltiazem), antihistamines (pyrilamine, cimetidine, diphenhydramine), or the elevator of cAMP IBMX were ineffective in blocking PAF-induced hemoconcentration. In contrast, CV-3988, reported to be a specific antagonist to PAF, was 98% inhibitory of PAF extravasation when given i.a. at 3.5 mg/kg. The ED50 was 0.14 mg/kg I.A. and 15 mg/kg p.o. against 75 ng/kg PAF. These data suggest that PAF-induced hemoconcentration involves receptor mediated alterations of vascular permeability that are inhibited by a specific PAF antagonist.     

Ultrasound and the Missing Loop

The use of ultrasonic echoscopy in the localisation of missing Lippes loops in 20 patients is described. The method is recommended as the initial investigation of choice in patients where the location of an IUCD is in doubt.