Biomedical subjects
Publications and source records attributed to O A Strand.
A case of chronic anisakiasis presenting as an occluding duodenal tumor is described. Significant falls in Anisakis simplex-specific serum IgE and total IgE occurred after resection of the lesion. Histopathologic examination showed a chronic eosinophilic granulomatous infiltrate and a tubular sclerotic structure in the antral submucosa consistent with, but not diagnostic for, an A. simplex larva.
OBJECTIVES: To study the relation between nitrite, nitrate, nitrotyrosine, and nitrosothiols as NO indices in human septic shock. DESIGN: A prospective clinical study. SETTING: Intensive care units in a university hospital and a central county hospital. PATIENTS: Sixteen patients admitted for septic shock. Nine healthy volunteers served as controls. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Patients with septic shock had a hyperdynamic circulatory response and required infusion of at least two vasopressors to maintain systemic blood pressure. Four episodes of recurrent shock occurred in two patients. Heparinized plasma was collected once daily for analysis of NO indices. Peak plasma concentrations of nitrite + nitrate (NOx) were elevated in first episodes of septic shock; 144+/-39 microM vs. controls, 20+/-3 microM (p < .05). Peak plasma NOx concentrations in recurrent shocks were; 160+/-19 microM. Peak plasma concentrations of 3-nitrotyrosine (NT) were elevated in primary septic shock 102+/-19 pmol x mL(-1) vs. controls 14+/-6 pmol x mL(-1) (p < .05). Peak NT concentrations were 117+/-37 pmol x mL(-1) in recurrent septic shock. Peak plasma NT concentrations did not coincide with peak NOx concentrations in half of the episodes of septic shock. Plasma NT was elevated (59+/-15 pmol x mL(-1) vs. controls 14+/-6 pmol x mL(-1), p < .05) in patients with normal plasma NOx concentrations throughout septic shock. Plasma concentrations of nitrosothiols did not change during septic shock. CONCLUSIONS: Plasma concentrations of NOx and NT are elevated in primary episodes of septic shock and may also be elevated in secondary septic shock, but too few episodes of recurrent septic shock occurred to allow firm conclusions. Plasma concentrations of NT are elevated in patients with septic shock with normal plasma NOx concentrations, indicating that plasma concentrations of NOx may not always accurately reflect NO production. Reactive nitrogen species may be formed in septic shock, and measuring both NOx and NT may give a better indication of NO production in septic shock than NOx alone. Plasma levels of nitrosothiols did not change during septic shock.
Nitric oxide (NO) is a naturally occurring molecule found in a variety of cell types and organ systems, including the cardiovascular, immune and nervous system. NO is normally produced in the endothelium from L-arginine by the constitutive isoform of the NO synthase (cNOS). Thereby, NO is an important regulator of vascular tone, prevents platelet adhesion, aggregation and activation, limits leukocyte adhesion to the endothelium and regulates myocardial contractility. This physiological production of NO is important for blood pressure regulation, blood flow distribution and tissue perfusion. Following injury or certain inflammatory stimuli, the expression of an inducible NO synthase (iNOS) can occur in a great variety of cells. In the last decade research on NO has suggested new treatment strategies for several diseases. In this review we discuss the biochemistry of NO and its basal physiological implications, with special emphasis on NO produced in the endothelium.
Animal experiments suggest that hyperproduction of nitric oxide (NO) by the inducible isoform of the enzyme NO synthase (iNOS) may contribute to hypotension, cardiodepression and vascular hyporeactivity in septic shock. Lipopolysaccarides and cytokines, like tumor necrosis factor, interleukin-1 and interferon-gamma, have been shown to induce iNOS in the endothelium, vascular smooth muscle cells, macrophages and different parenchymal cells. In several animal models of septic shock, treatment with inhibitors of NO synthesis has been shown to improve haemodynamic variables and survival. In human septic shock, inhibition of NO synthesis has been shown to alter haemodynamic variables in short term studies. However, a large multicentre study was recently stopped due to increased mortality in patients in septic shock treated with the NO synthase inhibitor NG-monomethyl-L-arginine. The aim of this review is to discuss the role of NO in sepsis and the potential therapeutic implications of NO as a target in treatment of human septic shock. We emphasize that many septic patients have preexisting endothelial dysfunction or lung diseases, which may predispose to severe adverse effects during systemic inhibition of NO synthesis. We also focus on the lack of direct evidence for iNOS expression in human septic shock and on the discrepancy between animal and human data.
Nitric oxide (NO) is normally produced in the endothelium by the constitutive isoform of the NO synthase. This physiological production of NO is important for blood pressure regulation and blood flow distribution. Several lines of evidence suggest that a hyperproduction of NO by the inducible form of NO synthase (iNOS) may contribute to the hypotension, cardiodepression and vascular hyporeactivity in septic shock. Lipopolysaccarides and cytokines, such as tumor necrosis factor, interleukin-1 and interferon-gamma, have been shown to induce iNOS in the endothelium, vascular smooth muscle cells, macrophages and different parenchymal cells. Treatment with inhibitors of NO synthesis has been shown to improve hemodynamic variables and survival in several animal models of septic shock. In human septic shock, inhibition of NO synthesis has been shown to alter hemodynamic variables in short-term studies, but it is uncertain whether this treatment has beneficial long-term effects. The aim of this review is to give an overview of the physiological role of NO and to discuss the role of NO in sepsis and the potential therapeutic implications of NO as a target in treatment of human septic shock. A main new aspect of this review is a critical discussion of previous reports measuring plasma nitrite/nitrate during septic shock and an evaluation of the validity of interpreting these data as evidence for a hyperproduction of NO. This review also emphasizes that many septic patients have preexisting endothelial dysfunction and lung diseases, which may contribute to adverse effects by systemic inhibition of NO synthesis. Another new aspect of the present review is a focus on the lack of direct evidence of iNOS expression in human septic shock.
OBJECTIVE: To test the effect of a continuous infusion of the nitric oxide synthase inhibitor N(G)-monomethyl-L-arginine (L-NMMA) on survival rate and hemodynamics in a pig model of endogenous peritoneal live bacterial sepsis. DESIGN: Prospective, randomized trial. SETTING: Laboratory at a university medical center. SUBJECTS: Thirty-five pigs with an average weight of 26 kg (range 21 to 33). INTERVENTIONS: After surgical preparation, animals (control, n=6) given anesthesia and fluids were observed for 9 hrs. Fifteen experimental animals received 0.5 g of cecal content/kg of body weight intraperitoneally after surgery. Nine of these animals received standard anesthesia and fluids and were observed for 9 hrs or until death. Six animals received a continuous infusion of L-NMMA (10 mg/kg/hr) 3 hrs after sepsis induction. Starting 3 hrs after surgery, five nonrandomized animals were given anesthesia and fluids and received a 6-hr continuous infusion of L-NMMA (10 mg/kg/hr). An additional nine animals were anesthetized and blood samples were taken to determine plasma nitrate concentrations in nonoperated pigs. MEASUREMENTS AND MAIN RESULTS: L-NMMA treatment increased 9-hr survival in septic animals from 11% to 83% (p < .001), prevented a further decrease in mean arterial pressure and restored mean arterial pressure to control levels (p < .00002 vs. nontreated septic animals). Mean pulmonary arterial pressure increased slightly during L-NMMA infusion (p < .0003). Coronary blood flow was preserved during L-NMMA treatment. Cardiac index and urine production reached and maintained control levels during L-NMMA treatment of septic animals. Mean central venous pH did not deteriorate during L-NMMA treatment. Animals treated with L-NMMA had plasma nitrate concentrations similar to nonseptic control animals. The results from the nonseptic control group receiving L-NMMA suggest that a substantial part of the effect of L-NMMA in this model of septic shock may be due to inhibition of the constitutive nitric oxide production. CONCLUSIONS: In this porcine model of peritoneal sepsis, infusion of L-NMMA increased survival rate and maintained mean arterial pressure without worsening tissue oxygenation. Coronary blood flow, cardiac index, systemic vascular resistance, and urine production were well maintained during L-NMMA treatment.
The effect of inhibiting nitric oxide (NO) synthesis during sepsis was studied in a caecal perforation model on Wistar rats. This model induces severe abdominal sepsis with a 48-h mortality > 90% in untreated animals. The survival time in hours (median values with the 95% confidence intervals in parentheses) for the control group was 15 (11.5-27.0) h. Treatment with the inhibitors of NO synthesis, NG-monomethyl-L-arginine (LNMMA), 30 mg kg-1 body weight (BW) or S-(2-aminoethyl)-isothiourea (AET), 3 mg kg-1 BW, given either once or twice after sepsis induction did not affect survival in this model. Survival time when LNMMA was given once was 13 (11-22) h and when given twice it was 14 (8-41) h. The corresponding survival times were 9 (4-28) h and 11 (5-27) h for treatment with AET. In conclusion, this study demonstrates that survival in the present model of live multiplying bacterial sepsis is not affected by either LNMMA or AET. Testing the potential clinical effects of inhibition of NO synthesis during sepsis should not be confined to short-term studies of haemodynamic changes induced by lipopolysaccharide.
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Two patients with haematologic malignancies developed Pneumocystis carinii pneumonia while under outpatient treatment, one on busulphan for chronic myelogen leukemia, and the other on prednisone plus chlorambucil for non-Hodgkin's lymphoma. The first patient was moderately ill and required hospitalization for 12 days while the second patient was critically ill and needed assisted ventilation for two weeks. Eventually they both recovered and returned to work. Tests for serum antibodies to the human immunodeficiency virus (HIV) were negative in both patients. We review the problem of P. carinii pneumonia in patients receiving immunosuppressive drugs.
In recent years, sympathomimetic drugs, including ephedrine, amphetamine and phenylpropanolamine, have been increasingly associated with cerebral haemorrhage and infarction. We report a case of intracranial bleeding in a 37 year-old woman with mononucleosis who took therapeutic doses of phenylpropanolamine. Cerebral CT on admission showed a left-sided intracerebral hematoma. Angiography was normal. Late bleeding occurred on the fourth day. She survived but developed a right-sided cerebral infarction with persistent epilepsy. Her mononucleosis was of moderate severity without bleeding diastesis. We conclude that the intracranial bleedings were secondary to taking phenylpropanolamine.
The prevalence of virus-specific serum antibodies of IgA class against cytomegalovirus (CMV) was determined in 228 healthy blood donors and in 112 patients suspected of CMV infection. All patients had a titer of 40 or higher in the complement fixation test. Specific CMV-IgA was found in 81 per cent of CMV-IgM positive patient sera and in 20 per cent of sera from patients strongly suspected of CMV infection, but with negative CMV-IgM. Less than 2 per cent of healthy blood donors had CMV specific serum IgA.
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The acquired immunodeficiency syndrome (AIDS) is a new, serious condition of major public health concern. It is most prevalent among young homosexuals and may be present with Kaposi's sarcoma and serious opportunistic infections. Physicians dealing with male homosexuals should be aware of this diagnostic possibility in any patient with unusual skin lesions or unusual clinical findings indicating infection. AIDS may be preceded by persistent generalized lymphadenopathy which may be accompanied by fatigue, low grade fever, night sweats and weight loss. The prognosis is poor with high mortality rates and no indication of spontaneous recovery of cellular immunocompetence.