Metabolic evidence of inadequate coronary blood flow during closed-chest resuscitation in dogs

Closed-chest cardiopulmonary resuscitation (CPR) produces only small pressure differences across the coronary circulation and relatively little coronary blood flow in dogs with ventricular fibrillation. To determine whether coronary flow during experimental resuscitation is sufficient to maintain aerobic myocardial metabolism, we measured left ventricular adenosine triphosphate (ATP) and lactate concentrations before and immediately after a 20 min period of CPR in six fibrillating dogs. The mean aortic-right atrial pressure difference generated during CPR averaged 5.4 +/- 2.6 mmHg (SEM) and 3.2 +/- 2.6 mmHg at the beginning and end of the 20 min period, respectively. Left ventricular myocardial blood flow (measured with radioactive microspheres) averaged 16.7 +/- 5.7% of prearrest values during the first 10 min of CPR, and 8.5 +/- 4.8% of prearrest values during the second 10 min of CPR. Biopsies after CPR contained less ATP (3.3 +/- 0.1 vs 4.7 +/- 0.5 nmol.mg-1, p less than 0.05) and more than seven times more lactate (14.7 +/- 3.1 vs 1.9 +/- 0.2 nmol.mg-1, p less than 0.01) than control biopsies. We conclude that coronary blood flow during CPR is inadequate relative to myocardial oxygen demands during ventricular fibrillation in dogs. The techniques developed in this study provide a potential means of assessing the effects of experimental interventions on myocardial oxygenation during CPR.     

Membrane Fatty Acid Replacements and Their Effect on Growth and Lectin-Induced Agglutinability

The growth of 3T3 and SV101 3T3 cells in a lipid-depleted medium is enhanced by the addition of biotin or some fatty acids. The extent of enhancement depends on the fatty acid(s) supplied. The presence of linoleate is unique, since it induces a morphological alteration in 3T3 cells resulting in a cell similar to an SV101-transformed 3T3 cell. Analyses of the fatty acids from the membrane phosphatides show that the exogenously supplied fatty acids are incorporated and alter the fatty acid composition. This is most clearly evident with heptadecanoate-grown cells, in which this fatty acid and its derivatives comprise over 45% of the fatty acids in the phospholipids.The fatty acid replacements have a striking effect on the temperature dependence of agglutination by wheat germ agglutinin and concanavalin A, implying that fluidity is involved in agglutination. These temperature dependencies and the effect of fatty acid replacements on them were different for the two lectins, but similar for both transformed and untransformed cells. These observations are interpreted as suggesting that the lipid phase is heterogeneous, and that transformed and untransformed cell membranes have regions of similar fluidity.     

Serum Zinc and Taste Acuity in Tel-Aviv Patients with Inflammatory Bowel Disease

Serum zinc levels and taste acuity were determined in patients with Crohn's disease, those with ulcerative colitis, and normal controls. All serum zinc values were within the normal range but significantly lower in the Crohn's disease patients as compared with controls. The taste threshold for salt was significantly impaired in patients with inflammatory bowel disease. These findings were less than expected and may be explained by the relatively high zinc intake normal for the Tel-Aviv population and relate indirectly to the high intake of refined carbohydrate that occurs in Crohn's disease patients.     

Urban legends series: Sjögren’s syndrome

Oral Diseases (2012) 19 , 46–58 Sjögren’s syndrome (SjS) is one of the most common autoimmune rheumatic diseases, clinically characterized by xerostomia and keratoconjunctivitis sicca. We investigated the following controversial topics: (i) Do we have reliable ways of assessing saliva production? (ii) How important are the quantity and quality of saliva? (iii) Are only anti‐SSA/Ro and anti‐SSB/La relevant for the diagnosis of SjS? (iv) Are the American‐European Consensus criteria (AECC) the best way to diagnose SjS? Results from literature searches suggested the following: (i) Despite the fact that numerous tests are available to assess salivation rates, direct comparisons among them are scarce with little evidence to suggest one best test. (ii) Recent developments highlight the importance of investigating the composition of saliva. However, more research is needed to standardize the methods of analysis and collection and refine the quality of the accumulating data. (iii) In addition to anti‐Ro/La autoantibodies, anti α‐fodrin IgA and anti‐MR3 autoantibodies seem to be promising diagnostic markers of SjS, but more studies are warranted to test their sensitivity and specificity. (iv) AECC are classification, not diagnostic criteria. Moreover, recent innovations have not been incorporated into these criteria. Consequently, treatment directed to patients diagnosed using the AECC might exclude a significant proportion of patients with SjS.