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Biomedical subjects

T Pohlman

Publications and source records attributed to T Pohlman.

6 recordsLinked to original sources

Diverticulitis.

Diverticulitis represents a spectrum of clinical entities ranging from minimal pericolitis in the adjacent mesentery to uncontrolled intra-abdominal sepsis and septic shock. The presentation most often described is left lower quadrant abdominal pain, fever, chills, and left lower quadrant tenderness associated with a mass. Unusual presentations occur when infection tracts to distant locations. Diverticulitis is a common cause of intra-abdominal sepsis associated with high morbidity and mortality. The pathogenesis of intra-abdominal sepsis is not well understood, but likely involves circulating host inflammatory mediators. The role of computed tomography in the early diagnosis of diverticulitis is increasing and supersedes barium enema in the assessment of the extracolonic extent of disease. Also, computed tomographic-directed percutaneous drainage of intra-abdominal abscesses is, in most cases, as effective as surgical drainage. Predictably, the micro-organisms involved are representatives from the commensal flora of the lower gastrointestinal tract. These bacteria are usually sensitive to a wide range of antimicrobial agents that are effective against facultative and obligate anaerobic gram-negative bacilli. Surgical intervention is reserved for those individuals who do not respond to therapy, or for generalized peritonitis, uncontrolled sepsis, free viscus perforation, and fistulas.

Bacterial Infections

Calcium paradox in canine kidneys.

Isolated perfusion of the heart with a Ca2+-free perfusate followed by a Ca2+-containing perfusate causes dramatic alterations in the physiology and biochemistry of the tissue, a phenomenon known as the calcium paradox. A similar paradoxical effect of Ca2+ has also been reported to occur in the kidney. In this study an attempt was made to reproduce the calcium paradox in canine kidneys and to characterize more fully its metabolic consequences. Canine kidneys were perfused with Krebs-Henseliet bicarbonate buffer free of Ca2+ for 30 min followed by perfusion with Ca2+ (1.5 mM). Unlike previously reported results no sudden decrease in flow was there a Ca2+-related sharp rise in rate of release of lactic dehydrogenase. In addition, we found no significant change in the level of tissue adenine nucleotides or functionality of isolated mitochondria. It is concluded that there is no calcium paradox in canine kidney under these conditions and it is suggested that the Ca2+ paradox may be characteristics only of muscle tissue that can undergo Ca2+-dependent contraction.

Animals

Plasma fibronectin concentration in animal models of sepsis and endotoxemia.

Plasma fibronectin is a nonspecific opsonin which mediates phagocytosis of particulate matter by macrophages. Fibronectin depletion results in depression of reticuloendothelial system phagocytic function. This may potentiate microvascular embolization and sludging in critical illness. It has been hypothesized that sepsis is a major cause of fibronectin depletion. To explore this hypothesis, plasma fibronectin concentrations were measured in rats with intraabdominal abscesses and in rabbits subjected to the generalized Shwartzman reaction (spaced doses of endotoxin). In both groups of animals there was a significant increase (P less than 0.05) rather than decrease in fibronectin concentrations at times when sepsis and disseminated intravascular coagulation were manifest. This study does not support the hypothesized relationship between sepsis and fibronectin depletion. Until the kinetics of fibronectin production and utilization are further delineated, caution must be exercised in the interpretation of immunoreactive plasma fibronectin levels.

Abdomen

Effects of prostacyclin on short-circuit current and water flow in the toad urinary bladder.

The effects of prostaglandins of the E series on sodium and water transport have been studied extensively. PGE2 has been shown to inhibit the increase in osmotic water flow produced by vasopressin and to stimulate short-circuit current (SCC) in the toad bladder. On the other hand, the effects of prostacyclin (PGI2), an arachidonic acid product, on sodium and water transport have not been extensively evaluated. The present studies describe the effects of PGI2 on basal and vasopressin-stimulated osmotic water flow and on SCC in the urinary bladder of the toad. Studies were performed in the absence or presence of indomethacin. PGI2 in the absence of indomethacin had no effect on basal or vasopressin-stimulated osmotic water flow. When indomethacin was present, thereby eliminating intrinsic prostaglandin biosynthesis, PGI2 inhibited basal but not vasopressin-stimulated osmotic water flow. PGI2 increased SCC in the presence or absence of indomethacin. 6-keto PGF1 alpha, the stable metabolite of PGI2, had no effect on SCC. PGI2 stimulated cAMP production in isolated toad bladder epithelial cells. 2',5'-Dideoxyadenosine, an inhibitor of cAMP production, blocked the increase in SCC produced by PGI2, suggesting that the effects of this compound on SCC are mediated via cAMP.

1-Methyl-3-isobutylxanthine