Endoscopic and histologic evaluation of advanced megaesophagus after esophagocardioplasty, vagotomy-antrectomy and roux-en-Y gastrojejunostomy (Serra Dória operation).

To evaluate the endoscopic and histologic aspects of the esophageal mucosa in patients who underwent the Serra Dória operation for advanced megaesophagus. Thirty patients with advanced megaesophagus underwent the Serra Dória operation (operated group) and 15 patients were not submitted to surgery (non-operated group). The esophageal mucosa was evaluated by macroscopy and histologic examinations. In the operated group, 21, five and four patients with mild, moderate and severe esophagitis, respectively, were identified by endoscopy. In the non-operated group, 4 and 11 patients had moderate and severe esophagitis, respectively. The histologic examinations identified 19, six and five specimens with mild, moderate and severe esophagitis, respectively, in the operated group as opposed to one, three and 11 specimens with mild, moderate and severe esophagitis, respectively, in the non-operated group. The prevalence of severe esophagitis was high in the non-operated group while, after the Serra Dória operation, mild esophagitis was prevalent.

Influence of dolichol on microsomal membrane functions.

Microsomal membranes from rat liver were extracted with n-pentane in order to remove the lipid products of the mevalonate pathway, dolichol, ubiquinone and cholesterol. Dolichol and cholesterol were subsequently reincorporated into these extracted membranes. Electron microscopic examination demonstrated that extraction did not alter the vesicular membrane structure of the microsomes. The extracted vesicles were permeable to uncharged molecules in the same manner as control microsomes but had an increased permeability for charged molecules. Enzyme denaturation was not observed. The contraction of extracted vesicles was greatly increased when the incubation medium was supplemented with non-penetrating compounds such as polyethylene glycol and was much greater than that of control microsomes. When extracted membranes were reconstituted with dolichol or cholesterol, the original lower degree of contraction was reestablished. The effects of dolichol reincorporation on a number of microsomal enzyme activities were investigated and some limited changes were observed. These results demonstrate that extraction of microsomes with n-pentane and subsequent reincorporation of dolichol is an effective approach for investigating the functions of this lipid. Dolichol and cholesterol both affect microsomal membrane fluidity, but only cholesterol modifies the activities of certain integral microsomal membrane enzymes to a larger extent.

Relationship between the endoplasmic reticulum-Golgi membrane system and ubiquinone biosynthesis.

The involvement of the various segments of the endoplasmic reticulum (ER)-Golgi system in ubiquinone biosynthesis in rat liver was investigated using subcellular fractionation. In addition to preparing rough (R) and smooth microsomes and three different Golgi fractions, a procedure was developed to isolate a smooth vesicle fraction, designated as smooth II (SII) microsomes. The electron micrographs, chemical composition, distribution of marker enzymes, pattern of glycosidases and glycosyltransferases and participation in cholesterol transport suggest that the vesicle components of this latter fraction are intermediary between the endoplasmic reticulum and Golgi system. Both R and smooth I (SI), but not SII microsomes nor Golgi vesicles demonstrate trans-prenyltransferase activity, which synthesizes the side-chain of ubiquinone from geranyl pyrophosphate (GPP). The subsequent enzyme, which transfers solanesyl pyrophosphate (sol-PP) to 4-hydroxybenzoate, is absent from R and SI microsomes, but present in SII microsomes and exhibits high levels of activity in all of the Golgi fractions. Thus, ubiquinone is synthesized sequentially in the ER-Golgi system and thereafter translocated from this compartment to other cellular membranes.

Acute myocarditis presenting as acute myocardial infarction.

Myocarditis, often caused by an infectious agent, may have a presentation mimicking that of acute myocardial infarction. The authors describe a young man who, when first seen in the emergency department, appeared to have an acute myocardial infarction with normal coronary arteries. At autopsy, the histologic findings were diagnostic of active myocarditis, mixed-cell type. Neutrophilic infiltration with microabscess suggested an infectious cause, although the etiology was uncertain. The patient's clinical course, pathologic findings, and several treatment modalities are discussed. The differentiation between acute myocardial infarction and acute myocarditis can be difficult. Electrocardiographic changes and enzyme elevations are common in both. Therefore, clinicians should consider myocarditis in all patients--particularly young patients--with normal coronary arteries and suspected myocardial infarction.

Lipid peroxidation of microsomal and mitochondrial membranes extracted with n-pentane and reconstituted with ubiquinol, dolichol and cholesterol.

Microsomes and mitochondria prepared from rat liver were extracted with n-pentane, a procedure which does not denature enzyme proteins. Protein and phospholipid were not extracted, but 75-80% of the total dolichol, 80-100% of the ubiquinone and 85-95% of the cholesterol were removed from both organelles by this procedure. Enzymatic and non-enzymatic lipid peroxidation in microsomes and non-enzymatic peroxidation in mitochondria were strongly inhibited when ubiquinol was reinserted into n-pentane-extracted membranes. When reconstitution with dolichol was performed, lipid peroxidation was increased or unchanged, while cholesterol decreased this activity in a concentration-dependent manner. In reconstitution experiments ubiquinol and dolichol together were less inhibitory than ubiquinol alone, whereas cholesterol accentuated the inhibitory effect of ubiquinol. Reconstitution with dolichols of different lengths, dolichyl esters or with alpha-unsaturated polyprenols further demonstrated that dolichol is not an antioxidant. It appears that mevalonate pathway lipids influence lipid peroxidation in membranes by modifying the properties of the bilayer.

Effect of dietary fat on rat liver microsomal and mitochondrial/lysosomal dolichol, phospholipid and cholesterol.

The influence of different fat diets on liver phospholipid, cholesterol and dolichol was studied. Rats were separated into four groups and fed standard laboratory chow (control), a diet containing linolenic acid, a coconut oil diet, or a corn oil-containing diet. After five weeks, microsomes and mitochondrial/lysosomal fractions were prepared from the liver, and lipid compositions were analyzed. No changes in phospholipid content were observed. In control animals, the fatty acid compositions of phosphatidylcholine and phosphatidylethanolamine in the two subfractions were similar. However, these two phospholipids showed different fatty acid patterns, which were altered independently upon dietary treatment. The dietary treatments resulted, in most cases, in decreased cholesterol and dolichol contents and, especially in microsomes, in a decreased level of esterification of both lipids. The fatty acid compositions of cholesteryl esters in the two subfractions showed significant differences and cholesterol was esterified to a large extent with linolenic acid when this fatty acid was supplied in the diet. The same dietary treatment exerted different effects on the cholesterol localized in the two different intracellular compartments. This difference was most pronounced in rats fed the corn oil-containing diet; microsomal cholesteryl esters exhibited increased saturation, whereas cholesteryl esters exhibited increased saturation, whereas cholesteryl esters in the mitochondrial/lysosomal fraction displayed decreased saturation. Dolichyl esters in the two cellular compartments had different fatty acyl compositions, with a considerably higher degree of saturation in microsomes. The various diets influenced the nature of the fatty acid moieties present in the isolated fractions and the effects on the two subfractions were opposite.(ABSTRACT TRUNCATED AT 250 WORDS)