Structural alteration in isolated rat liver nuclei after removal of template restriction by polyanions.

Specific polyanions release DNA template restrictions for DNA synthesis in isolated rat liver nuclei. The degree to which DNA synthesis is enhanced can be correlated with a spectrum of changes in nuclear structure Each polyanion which is effective in the release of template restriction produces a characteristic alteration in nuclear ultrastructure. Polyanions which have no effect on DNA synthesis do not appear to cause any change in nuclear organization or ultrastructure. Parallel measurements of nuclear DNA release and nuclear volume changes also indicate that template-activating polyanions cause remarkable changes in the structural organization of the treated nuclei. These results indicate that DNA template activation involves direct interactions between polyanions and nuclear constituents and suggest the possibility that naturally occurring polyanions might have a role in the control of gene activity

Morphological and biochemical studies of isolated mitochondria from fetal, neonatal, and adult liver and from neoplastic tissues.

A combined morphological and biochemical investigation of mitochondria from developing and rapidly growing tissues ( tumors, fetal, and very early neonatal rat liver) revealed mitochondria which were deficient in respiratory control, showed no valinomycin induced K(+) accumulation or spontaneous Ca(++) uptake, and were unable to undergo a swelling-contraction cycle. Electron microscopic examination of fetal and neonatal livers and a mammary tumor revealed mitochondria which differed from controls with respect to matrix density and ability to undergo reversible structural changes. The importance of isolation and assay media in interpretation of results is emphasized.

Evidence of Trypanosoma cruzi infection (Chagas' disease) among patients undergoing cardiac surgery.

BACKGROUND: Trypanosoma cruzi, the agent of Chagas' heart disease, is transmitted by triatomine insects and by blood transfusion. The emigration of several million people from T cruzi-endemic countries to the United States has raised concerns regarding a possible increase in cases of Chagas' heart disease here, as well as an increased risk of transfusion-transmitted T cruzi. To investigate these 2 possible outcomes, we tested a repository of blood specimens from multiply transfused cardiac surgery patients for antibodies to T cruzi. METHODS AND RESULTS: Postoperative blood specimens from 11 430 cardiac surgery patients were tested by enzyme immunoassay, and if repeat-reactive, were confirmed by radioimmunoprecipitation. Six postoperative specimens (0.05%) were confirmed positive. Corresponding preoperative specimens, available for 4 of these patients, were also positive. The other 2 patients had undergone heart transplantations. Tissue samples from their excised hearts were tested for T cruzi by polymerase chain reaction and were positive. Despite the fact that several of these 6 patients had histories and clinical findings suggestive of Chagas' disease, none of them were diagnosed with or tested for it. Patient demographics showed that 5 of 6 positive patients were Hispanic, and overall, 2. 7% of Hispanic patients in the repository were positive. CONCLUSIONS: No evidence for transfusion-transmitted T cruzi was found. All 6 seropositive patients apparently were infected with T cruzi before surgery; however, a diagnosis of Chagas' disease was not known or even considered in any of these patients. Indeed, Chagas' disease may be an underdiagnosed cause of cardiac disease in the United States, particularly among patients born in countries in which T cruzi is endemic.

Activation of the complement system by recombinant tissue plasminogen activator.

Recent trials have shown that recombinant tissue plasminogen activator (rt-PA) is an effective thrombolytic agent in patients with acute myocardial infarction. Because rt-PA converts plasminogen to plasmin, which is known to activate complement in vitro, we tested the hypothesis that rt-PA can induce in vivo activation of complement. Studies were performed in 12 patients with acute myocardial infarction. Six control patients had patent coronary arteries and did not receive rt-PA; these patients had normal values of the components of the complement system C4a (409 +/- 111 ng/ml) and C5a (8.8 +/- 1.8 ng/ml) with a slight elevation of C3a (204 +/- 6.6 ng/ml) in samples collected before coronary arteriography (253 +/- 25 minutes after onset of pain). After coronary arteriography, there was a slight decrease in the values of C4a (224 +/- 37 ng/ml), C5a (7.3 +/- 1.3 ng/ml) and C3a (164 +/- 35 ng/ml). The remaining six patients had complete coronary occlusion and received rt-PA (80 to 150 mg intravenously). In this treated group, before coronary arteriography the values of C4a (406 +/- 51.6 ng/ml) and C5a (8.1 +/- 1.9 ng/ml) were normal, and those of C3a were slightly elevated (250 +/- 76 ng/ml). All complement values obtained before rt-PA were similar to those in the untreated group. However, after administration of rt-PA (but before any angiographically detectable reperfusion), there was a striking increase in C4a (2,265 +/- 480 ng/ml; p less than 0.01), C3a (600 +/- 89 ng/ml; p less than 0.05) and C5a (30.0 +/- 4.5 ng/ml; p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Trimellitic anhydride Toxicity. A cause of acute multisystem failure.

A person exposed to trimellitic anhydride (TMA) an epoxy resin widely used in industry, experienced respiratory failure, anemia, and gastrointestinal bleeding. A lung biopsy specimen demonstrated intra-alveolar hemorrhage and damage to alveolar lining cells. The patient and six co-workers were examined. Results indicated the presence of hemolytic antibodies directed against TMA-haptenized erythrocytes, IgG, IgA, and IgM antibodies directed against TMA-erythrocyte complexes, and antibodies against TMA-human serum albumin. Antibody levels in the patient were greater than in the co-workers. The elevated antibody levels demonstrate the antigenic potential of TMA. However, the cause of the pulmonary and hematologic damage remains uncertain and may represent either immunologic or direct toxic effects of TMA. In patients with multisystem failure of this nature, occupational hazards should be added to the differential diagnosis.

Propionibacterium acnes infection following subdural tap.

The case of an infant who had subdural hematomas that became infected with Propionibacterium acnes is reported. This is the second reported case of intracranial Propionibacterium acnes infection resulting from diagnostic or therapeutic manipulation.

Preoperative disseminated intravascular coagulation associated with aortic aneurysms. A prospective study of 76 cases.

A prospective study of 76 preoperative patients with aortic aneurysms was undertaken to determine the true incidence of associated disseminated intravascular coagulation (DIC). Although 39% of the patients showed a notable elevation of the fibrin split products level, only three had thrombocytopenia and a clinical bleeding diathesis, as well. Thus, clinically overt DIC occurred preoperatively in only 4% of the patients. All three patients had extensive aneurysms that involved the thoracoabdominal aorta. Preoperative fibrinogen levels in this series tended to be high-normal or elevated and were not good indicators of underlying excessive fibrinolysis. Hemostatic abnormalities, such as ecchymoses and petechiae, may be the key to the clinical diagnosis of DIC in preoperative patients with aortic aneurysms.

Retrograde cerebral perfusion during profound hypothermia and circulatory arrest in pigs.

The purpose of this study was to evaluate the use of retrograde cerebral perfusion via the superior vena cava during profound hypothermia and circulatory arrest (CA) in pigs. In three groups of 5 pigs each, group A (control) underwent cardiopulmonary bypass and normothermic CA for 1 hour, group B underwent cardiopulmonary bypass, profound hypothermia, and CA (15 degrees C nasopharyngeal) for 1 hour, and group C underwent the same procedure as group B plus retrograde cerebral perfusion. In group A none awoke. In group B, 2 of 5 did not awake and 3 of 5 awoke unable to stand, 2 with perceptive hind limb movement and 1 moving all extremities. In group C all awoke, 4 of 5 able to stand and 1 of 5 unable to stand but moving all limbs. In neurologic evaluation group B had significantly lower Tarlov scores than group C (p = 0.0090). Group B mean wake-up time, plus or minus standard error of the mean, was 124.6 +/- 4.6 minutes versus 29.2 +/- 5.1 in group C (p = 0.0090). In group B late phase CA cerebral blood flow dropped 30.9% +/- 4.8%, but in group C it rose 24.7% +/- 9.3% (p = 0.0007, pooled variance t test, two-tailed). In group B late phase CA brain oxygenation decreased 46.0% +/- 13.9% but it increased 26.1% +/- 5.4% in group C (p = 0.0013). This difference was reduced somewhat during rewarming (B, -21.2% +/- 14.9%; C, 16.4% +/- 4.7%; p = 0.043). Group B rewarming jugular venous O2 saturation was 30.8% +/- 2.5% versus 56.0% +/- 4.4% in group C (p = 0.0011). We conclude that in pigs retrograde cerebral perfusion combined with profound hypothermia during CA significantly reduces neurologic dysfunction, providing superior brain protection.

Limiting homologous blood exposure.

Successful limitation of homologous blood transfusion may necessitate multiple strategies and advance planning. Preoperative and intraoperative autologous blood collection may have to be supplemented with hemostatic pharmacologic agents. The use of cytokines is increasing. More efficient use of directed donors can have an important role in blood use. As these expensive and time-consuming techniques become available, a major challenge will be to determine which patients may benefit from or really need them.

Effect of profound hypothermia on leukocytes and platelets.

Seventeen patients who underwent aortic arch replacement were subjected to profound hypothermia and circulatory arrest. At maximum cooling, platelet count dropped from 184 +/- 122 to 37 +/- 30 thousand per microliter, and the total leukocytic count fell from 6.27 +/- 4.0 to 1.47 +/- 0.6 thousand per microliter. The thrombocytopenia was partially reversed with rewarming. The total white cell count consistently returned to precooling values or higher (10.5 +/- 4.0). The mechanism for this cold induced phenomenon is not well understood.

Heparin monitoring during cardiopulmonary bypass.

Three procedures have been compared for monitoring heparin in patients undergoing cardiopulmonary bypass: (1) activated clotting time (ACT) (2) protamine titration, and (3) fluorometric substrate assay. The ACT monitors the degree of anticoagulation. It is easy to perform and is relatively inexpensive, however, it does not correlate well with heparin levels and may not accurately predict the protamine dose for neutralization of heparin at the completion of bypass. A protamine titration assay or an assay using a thrombin-sensitive fluorometric substrate measures the heparin level and calculates the protamine requirement at the completion of surgery; however, these assays do not indicate the degree of anticoagulation. The fluorometric assay is the less expensive of the two assay measuring heparin, but it requires an experienced technologist to perform the test.

Experimentally induced bleomycin sulfate pulmonary toxicity: histopathologic and ultrastructural study in the pheasant.

Morphological alterations in the lungs of pheasants after prolonged high-dosage administration of bleomycin sulfate were studied by light and electron microscopy. Nontreated birds acted as controls, and their lungs showed no abnormalities. Lungs of bleomycin-treated pheasants revealed collapse alternating with overexpansion, marked cuboidalization of atrial epithelium, and incipient interstitial fibrosis. There were neither lymphoplasmacytic or eosinophilic infiltrates, nor evidence of vasculitis. Ultrastructurally, type 1 alveolar epithelial cells were either reactive or conspicuously absent in the air capillaries. Type 2 alveolar epithelial cells appeared hyperplastic with numerous lamellar bodies, many of which extruded into air spaces. Immature fibroblasts were noted in the vicinity of collagen fibrils or amorphous material resembling elastin. No immune deposits were present in basement membranes. These findings are consistent with a direct toxic effect of bleomycin to the pheasant lung rather than a drug hypersensitivity reaction. Reproduction of the bleomycin lesion in a nonmammalian species corroborates even further the high propensity of the drug to affect the lung.

Viscoelastic measurement of clot formation: a new test of platelet function.

Assessment of platelet function presents a challenge to the investigators in the clinical field. An instrument, Sonoclot, is described which measures changes in the viscoelastic properties (clot impedance on a vibrating probe) of plasma as it is recalcified. Platelet poor plasma (PPP) and platelet rich plasma (PRP) show distinct and characteristic Sonoclot tracings. Tracings of PPP show a lag period and a primary wave. These parameters correspond to recalcification time and fibrin polymerization. Tracings of PRP show, in addition, a secondary wave and a downward wave. These parameters correspond to the incorporation of platelets in the clot and retraction of the clot. The PRP parameters are influenced by the number and quality of the platelets. This instrument was utilized to assess the platelet function in patients after coronary artery bypass surgery (CAB). In 69 patients studied, 20 patients did not have excessive bleeding. The clot impedance tracings in this group were normal. Twenty-four patients had excessive bleeding, normal clot impedance, and coagulation tests indicating the possibility of surgical bleeding. This was confirmed in 22 (92 percent) patients upon exploration to control bleeding. Twenty-five patients had excessive bleeding, normal coagulation tests and abnormal clot impedance suggesting platelet dysfunction. In twenty-one (84 percent) of the patients, transfusion of platelet concentrate controlled the bleeding with corresponding correction of clot impedance. Sonoclot studies are quick and easy to perform, and appear to be a valuable and reliable adjunct in the diagnosis of hemostatic problems after CAB surgery.

Fatal hepatoadrenal necrosis in the neonate associated with echovirus types 11 and 12 presenting as a surgical emergency.

Two neonates presented to our service with suspected intraabdominal surgical emergencies. Both subsequently were found to have hepatoadrenal necrosis due to overwhelming echoviral infection. Echovirus types 11 and 12 were isolated postmortem. The latter virus has not been associated previously with fulminant neonatal illness.

Blood salvage for cardiovascular surgery.

Intraoperative blood salvage produces safe and clinically effective red cells. Intraoperative salvage for cardiovascular surgery procedures can be expected to cause a substantial reduction in the use of homologous red cells in patients requiring redo operations, and repair of complex aortic aneurysms. The procedure per se will have very little impact on the use of other blood components such as platelets or plasma. For carefully selected patients, autologous perioperative or intraoperative collection of these components should also be considered. The primary risks of intraoperative blood transfusion include washout of clotting proteins and platelets, infusion of undesirable constituents (such as antibiotics and haemostatic agents added during the surgical procedure) and air embolism. Intraoperative autologous transfusion is only one part of an effective programme to minimize homologous transfusion. Equally important is the use of preoperatively donated blood, the use of effective and safe pharmacological agents to enhance haemostasis and haematopoiesis, a conservative approach that allows only the transfusion of blood components absolutely necessary, and, when possible, the elimination of anticoagulant and antiplatelet therapy several days prior to the cardiovascular surgical procedure.

Transfusion and coagulation: an overview and recent advances in practice modalities. Part II: Pharmacologic adjuncts, cell salvage mechanisms, alternatives in blood donation.

Increasing public awareness of the risks associated with the transfusion of blood products has encouraged the development of alternatives to the use of homologous blood. Pharmacologic agents, cell salvage, and directed donations are three such mechanisms being utilized with greater frequency for blood and component therapy. At present, only three drugs are available for clinical use: DDAVP, epsilon-aminocaproic acid, and tranexamic acid. Cell salvage is available in two system types. Salvage of whole blood in passive collection systems is simplest to use and returns more coagulation factors, but yields a larger volume with a lower hematocrit. Whole blood salvage with subsequent washing and resuspension in normal saline returns only red cells in saline with the majority of coagulation factors removed. The quality of red cells in each system remains relatively constant and the decision regarding which system to employ should be based on the nature of the surgical procedure and the anticipated blood loss. The development of directed donation programs, including autologous predonation and directed homologous donation, permits a reduction in the frequency and total number of units of homologous volunteer blood administered. Directed blood donation provides an additional source of donated blood, but is not demonstrably safer than the volunteer homologous pool, and in fact, may even be less safe. Given the increased complexity of maintaining a designated donor program, these issues of safety play an important role in the ability to maintain operation of large scale directed donation programs.

Impact of whole blood usage in massive transfusion.

A retrospective survey comparing blood and component usage during thoracoabdominal aortic reconstruction between patients receiving whole blood vs packed red cells was conducted. Volume of salvaged blood, usage of homologous blood components, and total homologous exposures were compared between eight patients who received only packed red blood cells and four patients who received whole blood for replacement of surgical losses, using a chi-square test for comparison. All variables demonstrated a decline among patients who received whole blood. The declines in homologous blood and plasma usage were statistically significant (P less than .05). The decline in platelet usage did not reach statistical significance. The decline in total homologous exposures approached statistical significance (P less than .1). The data suggest that use of whole blood for expected massive transfusion may reduce total blood-component requirements and total homologous exposures.

Cost comparison of intraoperative autologous versus homologous transfusion.

The cost of autologous transfusions using semiautomated instruments in 52 orthopedic cases, 75 coronary artery bypass graft (CABG) cases, and 218 aortic aneurysm cases was compared to the cost of equal amounts of homologous blood. While none of the orthopedic cases reached cost equivalence (median cost deficit per case, +97), 31 percent of the CABG cases (median cost deficit per case, +61) and 56 percent of the thoracic aortic aneurysm cases (mean cost surplus per case, +30) did so. In most cases, the major orthopedic and CABG procedures do not reach cost equivalence and might be served better by other means of autologous blood recovery. The more expensive semicontinuous flow devices are more cost-effective for higher-yield cases, such as major aortic aneurysm procedures.

Comparison of Brucella abortus and Brucella melitensis infections of mice and their effect on acquired cellular resistance.

By using mice infected with strains of Brucella abortus and Brucella melitensis we examined the histological responses to infection, the relationship of histology to persistence of organisms, and the relation of persistence of organisms to the acquisition of acquired cellular resistance (ACR). Infection with B. abortus resulted in well-formed granulomas in the livers, which persisted for more than 30 days. In contrast, infection with B. melitensis produced microabscesses in the livers which resolved before 30 days. The clearance of organisms from the tissues was also different. A total of 30 days after infection, large numbers of viable bacteria were recovered from the tissues of B. abortus-infected mice whereas bacteria were no longer recoverable from B. melitensis-infected animals. ACR to Listeria monocytogenes, another intracellular pathogen, persisted for more than 30 days in B. abortus-infected mice but waned rapidly in B. melitensis-infected animals. This disappearance of ACR due to B. melitensis paralleled the clearance of bacteria from the tissues.