Whole Blood Clot Lysis: Enhanced by Exposure to Autologous but not to Homologous Plasma

A new phenomenon is described: Whole blood clots lyse faster in the plasma of the same donor than in another donor’s plasma. We have confirmed this finding in 68 healthy volunteers by a standardized, pairwise analysis and have found a mean difference in clot weights of 8.8 ± 0.99% (SEM, p<0.0001) after 6 h of urokinase-induced (200 U/ml) clot lysis. Nu difference was found in a group of 7 pairs of identical twins. Further analysis revealed that increasing concentrations of platelets in the plasma reduced the difference significantly but did not abolish it. A 1:1 mixture of autologous with homologous plasma reduced the autologous advantage by almost 50%, thus making an inhibitor unlikely. The absence of cellular components in clots of platelet- poor plasma resulted in the loss of the advantage after 2 h of lysis, but not in the early phase. We conclude that there is a clear advantage of autologous over homologous clot lysis. Potential mechanisms are discussed and include an increased affinity of enzymes for their substrates in a given individual.

Quantification of the antibody response to Propionibacterium acnes in a patient with prosthetic valve endocarditis: - a case report

Background

The isolation of Propionibacterium acnes in blood cultures is often considered a contaminant. On rare occasions, P. acnes can cause severe infections, including endocarditis and intravascular prosthesis-associated infections. To evaluate the discrimination between a contaminant and a clinically relevant infection we used an Ouchterlony test system to quantify the antibody response to P. acnes in a patient with a proven P. acnes endocarditis.

Case presentation

We report on a 64-year-old Caucasian man who developed P. acnes endocarditis four years following a composite valve-graft conduit replacement of the aortic root. Bacterial growth in blood cultures was detected after an incubation period of 6 days. However, the antibody titer to P. acnes was 1:8 at the time of diagnosis and declined slowly thereafter over 2½ years. The patient’s response to the antibiotic treatment was excellent, and no surgical re-intervention was necessary.

Conclusion

The working hypothesis of infective endocarditis can be substantiated by serologic testing, which, if positive, provides one additional minor criterion. Moreover, quantification of the antibody response to P. acnes, though not specific, may assist in the differentiation between contaminants and an infection. This quantification may have implications for the patient management, e.g. indication for and choice of the antibiotic therapy.

[A drug addict presenting with complicated tricuspid valve endocarditis]

The right-sided heart valves are affected in about 10% of patients with infective endocarditis. However, the tricuspid valve is the most frequently involved valve in intravenous drug users with infective endocarditis. When treated with antibiotics, the prognosis is considered favorable. Reported here is the case of a drug-addicted patient with polymicrobial (Staphylococcus aureus and Streptococcus pneumoniae) infective endocarditis of the tricuspid valve and a lethal outcome due to multiple organ failure. The indications and options to perform cardiac surgery in patients with infective endocarditis of the tricuspid valve are discussed.

[Mechanical complications of acute myocardial infarction]

Rupture of the left ventricular myocardium during the course of an acute myocardial infarction may affect the free wall, the interventricular septum, or the papillary muscles. When a rupture occurs, it is referred to as a mechanical complication of acute myocardial infarction. All mechanical complications may lead to cardiogenic shock. However, the location of the rupture can often be suspected clinically. To confirm the diagnosis, echocardiography must be performed. Since the advent of thrombolytic therapy and percutaneous coronary intervention, the incidence of mechanical complications has declined. Even though mortality remains high, their recognition is important since survivors may have an excellent long-term prognosis. The cases convey two main messages: 1) Mechanical complications must be carefully searched for in any patient with an acute coronary syndrome and signs of cardiogenic shock and/or a systolic murmur. 2) Aggressive and timely medical and surgical treatment should be provided even though in a substantial proportion of these patients prognosis may be dismal.

[Late reconstruction of distal biceps tendon rupture with fascia lata graft and Mitek anchors]

Ruptures of the distal biceps tendon are rare but well documented. A technique for reinserting the distal biceps tendon into the radial tuberosity with two Mitek anchors and a fascia lata graft is presented and illustrated by a case report. Ectopic ossification as a complication after the procedure is discussed as well as the final outcome. It could be concluded that late reconstruction of the distal biceps tendon rupture with fascia lata and Mitek anchors is a safe procedure that can be advocated in a restricted number of cases where acute injury has been overlooked.

Plasmodium falciparum cerebral malaria complicated by disseminated intravascular coagulation and symmetrical peripheral gangrene: case report and review

The case of a 56-year-old female tourist who survived cerebral Plasmodium falciparum malaria with disseminated intravascular coagulation and symmetrical peripheral gangrene, ultimately requiring amputation of her left-sided fingertips and toes, is reported. While symmetrical peripheral gangrene has been described rarely in Asian, African, and American patients with Plasmodium falciparum malaria and disseminated intravascular coagulation, no such case has been reported in travelers returning from endemic areas.

Lack of influence of body exhaust gowns on aerobic bacterial surface counts in a mixed-ventilation operating theatre. A study of 62 hip arthroplasties

Aerobic bacterial surface contamination was studied with and without the use of body exhaust gowns in an operating room equipped with mixed/turbulent ventilation and separate operating and anaesthetic areas during 62 hip joint arthroplasties. In 31 operations conventional gowns were used, and 31 were performed with body exhaust gowns. Bacterial surface contamination was monitored in the operating and anaesthetic area using 9 cm diameter settle plates (1+1) and nitrocellulose membranes (2+2) transferred after sampling to nutrient pads. Compared with conventional clothing, the use of body exhaust gowns did not significantly reduce the microbial contamination (P=0.1-0.7). On the settle plates 1 m from the patient 279+/-326 cfu/m(2)/h were observed with conventional clothing compared with 142+/-227 cfu/m(2)/h with body exhaust gowns. The first membrane located on the patient in the sterile area detected 250+/-590 cfu/m(2)/h with conventional clothing and 210+/-320 cfu/m(2)/h with exhaust gowns. For the second membrane on the floor, the counts were 1790+/-2700 and 1590+/-1590 cfu/m(2)/h. For all operations the settle plates yielded 210+/-287 cfu/m(2)/h in the operating area and 720+/-564 cfu/m(2)/h in the anaesthetic area (P=0.01). Compared with the membrane placed on the anaesthetic equipment the counts on the membrane placed on patient were also significantly lower (P=0.01) while the membranes placed on the floor in each area showed no difference in counts. In conclusion, compared with conventional clothing, the use of body exhaust gowns could not be proven to provide more protection against microbial contamination. The low number of colony forming units found in the operating area was similar to that expected from an ultraclean laminar airflow unit, although achieved with a cheaper and more energy saving system.

Regulation of plasminogen binding to neutrophils

Plasminogen plays an integral role in the inflammatory response, and this participation is likely to depend on its interaction with cell surfaces. It has previously been reported that isolation of human neutrophils from blood leads to a spontaneous increase in their plasminogen-binding capacity, and the basis for this up-regulation has been explored as a model for mechanisms for modulation of plasminogen receptor expression. Freshly isolated human peripheral blood neutrophils exhibited relatively low plasminogen binding, but when cultured for 20 hours, they increased this capacity dramatically, up to 50-fold. This increase was abolished by soybean trypsin inhibitor and was susceptible to carboxypeptidase B treatment, implicating proteolysis and exposure of carboxy-terminal lysines in the enhanced interaction. In support of this hypothesis, treatment of neutrophils with elastase, cathepsin G, or plasmin increased their plasminogen binding, and specific inhibitors of elastase and cathepsin G suppressed the up-regulation that occurred during neutrophil culture. When neutrophils were stimulated with phorbol ester, their plasminogen binding increased rapidly, but this increase was insensitive to the protease inhibitors. These results indicate that plasminogen binding to neutrophils can be up-regulated by 2 distinct pathways. A major pathway with the propensity to markedly up-regulate plasminogen binding depends upon the proteolytic remodeling of the cell surface. In response to thioglycollate, neutrophils recruited into the peritoneum of mice were shown to bind more plasminogen than those in peripheral blood, suggesting that modulation of plasminogen binding by these or other pathways may also occur in vivo.

[Acute isolated ventral dislocation of the head of the fibula]

We present the case of a 19-year-old soccer player who had sustained a valgus, external rotation trauma to the flexed knee with traumatic anterolateral dislocation of the proximal tibiofibular joint and concomitant partial peroneal nerve palsy, which went away within a few days. We discuss the clinical features and treatment by temporary screw fixation of the proximal tibiofibular joint, as well as the results in the literature where predominantly conservative treatment is reported.

The cell biology of the plasminogen system

The plasminogen system plays a pivotal role in maintaining vascular patency and in cell migration. Binding of plasminogen to surfaces (i.e., fibrin or cells) is of crucial importance in regulating the function of this system. Plasmin(ogen) binds to cells with low affinity and high capacity via its lysine binding sites, which are associated with its kringle domains and recognize carboxy-terminal lysines of cell surface proteins. Upon binding to cellular receptors, plasminogen is more readily activated; bound plasmin has increased enzymatic activity and is protected from inactivation by inhibitors. Plasminogen receptors are modulated by numerous factors, including proteases, steroid hormones, cytokines and the adhesive state of the cells. The apoprotein(a) moiety of lipoprotein(a) is remarkably similar in amino acid sequence to plasminogen. Shared binding sites for lipoprotein(a) and plasmin(ogen) on cell surfaces and in the subendothelial matrix may contribute to the pathogenetic risks associated with elevated levels of lipoprotein(a).

Fibrin formation and degradation in patients with arteriosclerotic disease

BACKGROUND

The blood coagulation cascade was reported to be activated in patients with arteriosclerotic disease of the lower limbs (peripheral arterial disease, PAD). There is more thrombin and fibrin formation compared with healthy control subjects. In many studies, however, the presence of arteriosclerotic disease had not been thoroughly ruled out in the control group. Therefore, markers of the activation of the blood coagulation cascade were measured in patients with PAD and in a carefully defined control group, both groups being subjected to an exercise test.

METHODS AND RESULTS

Twenty-two patients with angiographically documented PAD of grade II (Fontaine classification) and 13 control subjects in whom the presence of arteriosclerotic lesions was ruled out by noninvasive means in the carotid arteries, abdominal aorta, leg arteries, and coronary arteries took part in the study. Before and immediately after a treadmill stress test, the concentrations of prothrombin fragment F1 + 2 (F1 + 2), thrombin-antithrombin III complexes (TAT), fibrinopeptide A (FPA; this peptide was measured in spot urine also), and D-dimers were measured. Before exercise, the concentrations of F1 + 2 (1.0 +/- 0.6 versus 0.7 +/- 0.3 nmol/L), TAT (2.9 +/- 2.1 versus 1.9 +/- 0.8 micrograms/L), and D-dimers (318.2 +/- 270.1 versus 150.0 +/- 91.4 micrograms/L) were significantly higher in the patients with PAD compared with the healthy control subjects. FPA concentrations in plasma (1.9 +/- 1.0 versus 1.4 +/- 0.6 micrograms/L) and spot urine were not different, however. F1 + 2, FPA, and D-dimer concentrations correlated with the severity of the PAD as assessed by the ankle systolic blood pressure index (ABPI). The symptom-limited stress test did not lead to further activation of the blood coagulation cascade. However, concentrations of F1 + 2 (P < .001) and TAT (P < .01) after exercise correlated with the presence of ischemic changes in the stress-test ECG.

CONCLUSIONS

There is evidence of enhanced thrombin formation in patients with PAD compared with an age- and sex-matched control group without clinical and sonographic evidence of arteriosclerosis. The thrombin formed, however, appears to be almost completely neutralized by antithrombin III. No direct evidence of fibrin formation was obtained, since the FPA concentrations were not different. In the patients with PAD, the higher concentrations of D-dimers are indicative of in vivo fibrinolysis. Thus, some fibrin formation must be postulated to occur in patients with arteriosclerosis.

Affinity membrane identification of immunoglobulin subclass in hybridoma screening

Monoclonal hybridomas secrete immunoglobulins with a single antigen specificity and distinct class/subclass structure. Hybridoma management has commonly incorporated tests of antigen specificity into early screening procedures, but has not typically utilized assays of immunoglobulin structure. In this article, we describe a technique of class/subclass typing using polyvinylidene difluoride affinity membranes and a colorigenic enzymatic amplification system. The typing of monoclonal antibody structure was sufficiently sensitive to permit its routine use within several weeks of hybridoma fusion. The information obtained from early and routine class/subclass determinations included a semiquantitative assessment of monoclonal antibody concentration. In addition, the detection of a single immunoglobulin class/subclass in a microtiter well supernatant supported the possibility that the colony was monotypic. The application of class/subclass typing and Poisson statistics to hybridoma fusions provided a numerical estimate of the probability of colony monotypia.

Whole blood clot lysis: enhanced by exposure to autologous but not to homologous plasma

A new phenomenon is described: Whole blood clots lyse faster in the plasma of the same donor than in another donor's plasma. We have confirmed this finding in 68 healthy volunteers by a standardized, pair-wise analysis and have found a mean difference in clot weights of 8.8 +/- 0.99% (SEM, p < 0.0001) after 6 h of urokinase-induced (200 U/ml) clot lysis. No difference was found in a group of 7 pairs of identical twins. Further analysis revealed that increasing concentrations of platelets in the plasma reduced the difference significantly but did not abolish it. A 1:1 mixture of autologous with homologous plasma reduced the autologous advantage by almost 50%, thus making an inhibitor unlikely. The absence of cellular components in clots of platelet-poor plasma resulted in the loss of the advantage after 2 h of lysis, but not in the early phase. We conclude that there is a clear advantage of autologous over homologous clot lysis. Potential mechanisms are discussed and include an increased affinity of enzymes for their substrates in a given individual.

Prothrombin fragment 1 + 2, thrombin-antithrombin III-complexes and fibrinopeptide A in spontaneously clotting whole blood in vitro. Effects of heparin addition and antithrombin III deficiency

Previous in vitro studies using spontaneously clotting whole blood revealed thrombin formation and high fibrinopeptide A (FPA) concentrations measured during incubation time. This occurred in spite of normal concentrations of thrombin antagonists present in the blood of the healthy subjects examined. However, there are several reports showing that in vivo increased thrombin-antithrombin III-complex (TAT) concentrations and relatively low FPA concentrations may occur e.g. in patients with (pre)thrombotic disorders. These in vivo findings indicate more effective thrombin inhibition by antithrombin III, with almost no fibrin formation. To find an explanation for the differences observed in vitro and in vivo, we extended the in vitro studies by measuring concentrations of prothrombin fragment 1 + 2 (F1 + 2), TAT and FPA at several time points until 30 min. Our goal was to test whether thrombin at least initially is neutralized by antithrombin III, resulting in a lack of fibrin formation, either in the absence or in the presence of heparin (0.2 and 0.5 U/ml whole blood, respectively). In the absence of heparin a simultaneous increase in the concentrations of F1 + 2, TAT and FPA was observed. Thrombin was only partially neutralized by antithrombin III and large amounts of fibrin were formed. The addition of heparin virtually suppressed thrombin formation since the F1 + 2 concentration remained low. Moreover, the small amounts of thrombin formed were neutralized by antithrombin III to a greater extent than in the absence of heparin.(ABSTRACT TRUNCATED AT 250 WORDS)

[Therapy of acute salicylate poisoning]

Poisoning with salicylic acid and its derivatives is a quite common event, leading to possibly life-threatening complications. A case of fatal intoxication of a sixty-year old patient with acetylsalicylic acid is described and the therapeutic options are discussed. In acute poisoning it is mandatory to initiate simple and effective measures first. This gives time for discussing and planning the more laborious procedures. The initial treatment of salicylate poisoning is based on the prevention of further absorption by a sufficiently large quantity of orally administered activated charcoal (approximately 1 g/kg b.w.). Given repeatedly, activated charcoal may enhance non-renal clearance of salicylates. Intravenously administered sodium bicarbonate counteracts the metabolic acidosis. Moreover, bicarbonate therapy limits tissue distribution of the drug and enhances its renal excretion. The availability of glycine for salicylic acid metabolism may be limited in poisoning because glycine has been used for forming the conjugation product salicyluric acid. Glycine may be administered orally to overcome this bottleneck. Gastric lavage has been proven to be of limited efficacy. This efficacy is further diminished if gastric lavage is performed late after drug ingestion. When it is performed, however, activated charcoal should be administered before and after gastric lavage. Whenever the more simple treatment options fail, hemodialysis or hemoperfusion should be additionally considered since these procedures are effective in removing salicylates from the body.

[Malignant neuroleptic syndrome under metoclopramide and neuroleptics in anuria]

A patient with myeloma nephropathy and acute, probably diclofenac-induced renal failure developed a neuroleptic malignant syndrome (NMS) during treatment with metoclopramide and neuroleptics. These drugs were withdrawn, symptomatic treatment of NMS was started and the patient was hemodialyzed because of uremia. During hemodialysis, the patient's condition improved dramatically and NMS did not recur during her further stay in the hospital. The temporal relationship between metoclopramide administration and the development of NMS, as well as the rapid reversal of NMS, suggest that NMS in this patient was caused by metoclopramide and not by neuroleptic drugs. Thus, metoclopramide should be used with caution in patients with renal failure and patients should be monitored closely for the development of neuroleptic malignant syndrome. Hemodialysis may be therapeutically effective in certain patients with metoclopramide-induced NMS.

[Hypotensive crisis]

The physiology of arterial blood pressure regulation is briefly reviewed and the differential diagnosis of arterial hypotension discussed. The shock syndrome consists of four different forms: cardiogenic, obstructive, hypovolemic, and distributive shock. The etiology of anaphylaxis is mentioned and its therapy outlined. Patients with Addison's disease or severe hypothyroidism are hypovolemic, but peripheral resistance is also altered. Therapy consists of hormone replacement. The cytokines play a major role in the pathogenesis of septic shock. At present there are no therapeutic tools available to modulate their detrimental effects clinically.

Increased thrombin-antithrombin III complexes after 1 h of physical exercise

Concentrations of thrombin-antithrombin III (TAT) complexes in plasma were previously reported to be increased after a 100-km run, while fibrinopeptide A (FPA) concentration remained unchanged. Thus, antithrombin III appears to neutralize thrombin generated during running and prevents fibrin formation. To determine the clinical relevance of these findings, we compared the effects of exhaustive running (1 h, n = 10) on the plasma concentrations of prothrombin fragments F1 and F2, TAT, FPA, and beta-thromboglobulin with the effects of recreational jogging (1 h, n = 10) and exhaustive bicycling on an ergometer (1 h, n = 8). Prothrombin fragments F1 and F2 and TAT concentrations increased significantly in each group. The most significant increase in TAT concentration was measured in the running group (from 1.72 +/- 0.49 to 3.61 +/- 1.03 ng/ml, P < 0.001). The best correlation was found between the postexercise TAT and lactate concentrations (r = 0.62, n = 28, P < 0.001). Mean FPA concentrations after exercise did not exceed normal values in any of the three groups analyzed. An increase in beta-thromboglobulin concentration was measured in the running and in the cycling group. Thus, thrombin is formed, in particular, when associated with anaerobic metabolism, and platelets are activated during high-intensity exercise.

[Consequences of circadian variability for the treatment of ischemic heart disease]

The incidence of ischemic cardiac events is highest in the early morning hours (symptomatic and asymptomatic cardiac ischemia, myocardial infarction, and sudden death). Quantitatively, however, most of them occur during the rest of the day; therefore, an ideal therapy should be established in the early morning hours and be efficient all day long. We recommend that nitrates should be taken as early as possible after a dose-is-free interval during the night. Patients taking beta-blockers do not show a circadian rhythm of the incidence of ischemic cardiac events. Compliance can be improved with the never long-acting agents. Therapy should be tailored individually for each patient. It is not yet known whether calcium blockers influence the circadian rhythm. The efficacy of the never preparations is comparable to the older ones. Aspirin can be taken at any time of the day because of its long duration of action.

Circulating catecholamine concentrations in cocaine-exposed neonates: a pilot study

Twenty newborns, 12 with prenatal exposure to cocaine and an unexposed control group of 8, were studied to determine concentrations of circulating catecholamines and their relationship to newborn behavior. Birth weight of the cocaine-exposed neonates was significantly lower than that of the control group. Gestational age, length, and head circumference of the cocaine-exposed neonates were also lower, although the differences did not reach statistical significance. Between 24 and 48 hours of age, circulating concentrations of norepinephrine, dopamine, and the catecholamine precursor dihydroxyphenylalanine were measured and behavior was assessed using the Neonatal Behavioral Assessment Scale. Mean dihydroxyphenylalanine concentrations were increased in the cocaine-exposed newborns (10.3 ng/mL vs 5.9 ng/mL, P = .055), while there was no difference between the groups in mean norepinephrine or dopamine concentrations. There was a significant negative correlation between norepinephrine concentration and orientation cluster score for the cocaine-exposed newborns (r2 = .6979, P = .005). norepinephrine concentration did not correlate with the score for any other behavioral cluster, nor did dopamine or dihydroxyphenylalanine concentration correlate with the score for any cluster. These preliminary data from a pilot study suggest that catecholamine activity is increased in cocaine-exposed newborns and may play a role in neurobehavioral disturbances associated with prenatal exposure to this drug.

[Histology of the implant-bone interface in cemented and uncemented endoprostheses]

The introduction of bone cement into endoprosthetic surgery was a significant step forward from the 'pre-cement' era. Nonetheless, its disadvantages soon stimulated the search for better means of anchoring implants without cement. Interest focuses on the so-called interface zone, which is the area between bone and foreign body. On the basis of light-microscopical findings our understanding of the biological and biomechanical interactions has influenced the principles of prosthetic design and the implant materials selected for use. The present article gives a synopsis of the histomorphology of the interface, with special reference to stability, tissue reactions, wear products, and implant fixation at bone surfaces (concerning bony ingrowth, osseointegration, and bonding). In all, 127 histological specimens of total hip and knee revisions were reviewed, in addition to a total of 24 non-cemented polyethylene cups retrieved at autopsy.