Cryopreserved homograft and autologous deep vein replacement for infrarenal aorto and iliaco-femoral graft infection: early and late results.

AIM: The aim of the study was to evaluate the early and late results of aortic replacement using cryopreserved homografts and autologous deep veins for infected infrarenal prosthetic reconstructions and the influence of type of bacteria on the mortality. METHODS: Thirty-three patients were treated from 30 March 1994 to 01 September 2008 for aorto-femoral or iliaco-femoral graft infections with homografts (HG:19) or autologous deep veins (DV:14). The diagnosis was based on physical signs, bacteriological tests and computed tomography(CT) scans. We obtain cryopreserved homografts from our non-profit vessel bank, deep veins were harvested before the arterial reconstruction. Patients were followed by clinical examination and ultrasound. RESULTS: The infections occurred 47.78 ± 20 months after the primary operations; 45% of the infections were caused by Gram-negative bacteria. Treatment indications included seven aortoduodenal fistula (21.2%) and six septic para-anastomotic bleedings (18.2%). There were six in-hospital deaths (18.2%). All the deceased patients had Gram-negative bacteria in cultures and pluribacterial infections. No patient died with single staphylococcus, streptococcus or MRSA infection. At three years freedom from reinfection was 100% in DV group and 82% (CI:0.56-0.92) in the homograft group. Survival after three years was 71% (CI:0.48-0.88) in HG group and 79% (CI:0.49-0.94) in DV group. The difference is not significant. CONCLUSION: For infrarenal graft infection homograft replacement or deep vein implantation is durable method and eradicate late reinfection. The in-hospital mortality is significantly higher in patients with aortoduodenal fistulas with Gram-negative organisms regardless of the conduit used for aortic replacement.

[Depression and professional activity: results of the NEXTEP study]. / Dépression et activité professionnelle : résultats de l'observatoire NEXTEP.

BACKGROUND: Depression is one of the most common diseases. It is associated with a significant psychosocial disability and many studies have shown that it results in numerous sick-leaves, with substantial economic burden. However, most of the studies have been conducted in Northern Europe and the situation in France remains unknown. OBJECTIVES: To describe the management of depressive patients and assess the impact of treatment on professional activity and sick-leave. METHODS: An epidemiological observational longitudinal study (NEXTEP) performed by TNS Healthcare in private practice psychiatrists. RESULTS: Data of 2516 patients included by 771 psychiatrists were analyzed. Patients aged 20 to 60 years, with professional activity and presenting with major depression were eligible if they were prescribed an antidepressant drug for the first time by this psychiatrist on the day of consultation. Women represented 65% of the cohort. Mean MADRS score at baseline was 34±7.7/60 and 47% of patients had a severe depression; only 5% had mild depression. Professional activity was impaired in 95% of cases. A sick-leave certificate was granted to 35% of the patients at the end of the first visit (first sick-leave or renewal in 14% and 21% of cases, respectively), and 100% were prescribed a pharmacological treatment (antidepressant agent). After 2 months, MADRS scores had dramatically decreased (-21 points on average) and 50% of the patients were symptom free. Most patients (75%) perceived improvement in working capacity; only 13% of patients received a sick-leave certificate. Escitalopram was associated with a significantly greater improvement in depressive symptoms, along with a significantly lower number and duration of sick-leave certificates. In multivariate analysis, predictors of depression improvement were decreased in anxiety, improved in self-esteem, and escitalopram treatment. DISCUSSION: Frequency and duration of sick-leave appear lower than in other studies, notably those conducted in Scandinavian countries. However, employment laws are different, which may influence the physicians' attitudes. CONCLUSION: This study is the first that accurately describes the management of depressive patients and the impact of treatment on professional activity and sick-leave in France. It suggests that an appropriate management of depressive patients results in a rapid improvement of symptoms and work resumption in most cases.

The role of autologous antebrachial arteriovenous fistula in the strategy of access planning for chronic uremic patients on hemodialysis.

AIM: The number of arteriovenous (AV) fistula creation increases worldwide. Haemodialysis is more effective, patients live longer, and they need more access operations. The optimal strategy for the order and sequence of the different type and localization of AV fistulas remains obscure. Based on internationally acclaimed guidelines, autogenous access should be performed whenever possible and the first operation of choice is the radiocephalic fistula at the wrist, the second type is the elbow fistula. The area between the standard exposures means also good access area and its usage is not emphasized properly. Our aim was to study the short and long-term the results of autologous forearm fistulas. METHODS: Between 1997 and 2005 we performed 1018 AV shunts in an academic tertiary care centre. Ninety-seven autologous antebrachial AV shunts were performed. The average follow-up time was 31.3 months. We examined the patency rate and its connection with different variables such as diabetes mellitus, acute or chronic operative situations, indications for surgery, diameter and quality of the vein. RESULTS: The primary patency rates were 93%, 79.5% and 61.2% at the end of years 1, 2 and 6, respectively. The patency rate was not significantly affected by any of the examined variables mentioned above. CONCLUSION: The patency rate of the autologous antebrachial AV shunt is comparable to the wrist and elbow fistulas, so our results support the practice of performing fistula at this atypical localization. Proximal autologous fistulas and prosthetic graft implantation could be postponed, this way valuable time could be saved for the uremic patients.

Comparison of acute cardiovascular effects and oxygen-supply following haemodilution with dextran, stroma-free haemoglobin solution and fluorocarbon suspension.

Changes in haemodynamics and myocardial oxygen-supply were investigated in anaesthetised dogs, when the haematocrit was reduced to 18 to 22% by isovalaemic haemodilution with 8% stroma-free haemoglobin solution, 20% Fluosol-DA and 6% dextran 70. Comparable haemodilution and comparable reduction in whole-blood viscosity was not followed by similar changes in cardiac output: dextran- and Fluosol-diluted dogs showed significantly elevated cardiac output, while haemoglobin-diluted dogs failed to do so. As a result, systemic O2-transport was better maintained with dextran and Fluosol. Myocardial blood flow, estimated by 15 micrometers microspheres, increased in all three haemodiluted groups, but oxygen-supply was not similar. The haemoglobin-diluted dogs showed inadequate O2-supply suggested by a fall of coronary sinus pO2; dextran-diluted dogs exhibited adequate O2-supply suggested by maintained coronary sinus pO2, while the Fluosol-diluted group enjoyed excessive O2-supply, indicated by a markedly elevated pO2 in coronary sinus blood. The observations suggest that similar degrees of haemodilution may not be followed by comparable changes in haemodynamics and O2-supply, depending on O2-unloading characteristics.

Myocardial blood flow and O2-supply following dextran-haemodilution and methaemoglobinaemia in the dog.

The adequacy of oxygen-supply to the left ventricular myocardium was compared in anaesthetised dogs following: a) isovolaemic haemodilution with Dextran 70 (to haematocrit = 20 +/- 2%), b) the acute induction of methaemoglobinaemia (to methaemoglobin-concentration = 53 +/- 7%), bu subjecting them to an exchange-transfusion with methaemoglobin-containing erythrocytes in dextran) and c) a control exchange-transfusion with normal homologous erythrocytes in dextran. Myocardial oxygen-supply was assessed by the measurement of myocardial blood flow (using 15 +/- 5 micron microspheres) and of the PO2 in coronary sinus blood. In dextran-haemodiluted dogs, mean myocardial blood flow was 92% greater than in the control group, allowing the maintenance of normal coronary sinus PO2. In the methaemoglobinaemic group, flow was only 15% greater than in the control group; because oxygen-capacity was halved in this group, myocardial oxygen supply was impaired and coronary sinus PO2 fell. Infusions of isoproterenol (0.1 microgram . kg-1 . min-1) produced similar myocardial flow-increments in the haemodiluted and control groups with similar transmural distribution. In the methaemoglobinaemic group, however, the subendocardial flow-increment was reduced, in association with a further reduction in coronary sinus PO2 and an attenuated contractile response to the drug. These findings suggest that the rheological effects of haemodilution play an important role in the maintenance of myocardial oxygen-supply, but in significant methaemoglobinaemia, the oxygen supply of the myocardium may be severely curtailed.

Perfluorocarbon blood substitutes.

The salient physicochemical properties of the fluorocarbons are briefly reviewed, including their solubility for the physiologically important gases and their properties relevant to formulation (nonmiscibility with water). The preparations used to date are described, including their properties and compositions, with some comment about the available knowledge of the properties of the constituents. A critical review of the biological aspects and the possible uses of fluorocarbon emulsions constitutes the main body of the manuscript. Gas-transporting capabilities are considered quantitatively. The biological effects of these preparations are reviewed in in vivo, whole body systems, with some in vitro evidence where appropriate. The usefulness of these preparations investigated to date are reviewed under the broad headings of cardiovascular system, radiology, intoxications, and organ preservation. Finally, the shortcomings and potential usefulness are discussed, with recommendations for potential modifications.

Changes in regional blood flow distribution induced by infusions of dopexamine hydrochloride or dobutamine in anesthetized dogs.

Systemic blood flow distribution was determined using radionuclide-labeled microspheres in anesthetized dogs during infusions of dopexamine hydrochloride or dobutamine. Three doses of the drugs were administered intravenously, in the form of 22-minute infusions (3 X 10(-9), 10(-8), 3 X 10(-8) mol/kg/min [1.3 to 12.9 micrograms/kg/min] dopexamine hydrochloride and 10(-8), 3 X 10(-8), 10(-7) mol/kg/min [3.4 to 34.0 micrograms/kg/min] dobutamine). Both drugs induced dose-dependent acceleration of the heart rate. Blood pressure was maintained during infusions of dobutamine, while dopexamine hydrochloride induced arterial hypotension. As a result, the increments in heart rate-blood pressure product were smaller with dopexamine hydrochloride than with dobutamine. Dopexamine hydrochloride induced blood flow increments in the heart, several sections of the gastrointestinal tract, kidney and skeletal muscle. Quantitatively, these changes were different from those induced by dobutamine in only 3 organs. The myocardial blood flow increments during infusions of dopexamine hydrochloride were smaller than those of dobutamine, whereas in the stomach and in skeletal muscle, the flow increments induced by dopexamine hydrochloride were significantly greater than those induced by dobutamine. The findings suggest that dopexamine hydrochloride, by virtue of its agonist activity at beta 2-adrenergic and DA1- and DA2-dopaminergic receptors, is a powerful vasodilator.

The effects of Ca++ on the preservation of myocardial energy and function with University of Wisconsin solution. A 31P nuclear magnetic resonance study of isolated blood perfused Langendorff pig hearts.

We have studied the effects of adding 0.5 mmol/L CaCl2 to University of Wisconsin solution (0.08 mmol/L free Ca++) on hypothermic heart preservation. Isolated pig hearts were subjected to 8 hours of preservation at 12 degrees C; eight hearts were arrested with Ca++ free University of Wisconsin solution, and seven hearts were arrested with Ca(++)-containing University of Wisconsin solution. The recovery of contractile function was evaluated by measuring isovolumic ventricular pressure development. 31P nuclear magnetic resonance spectroscopy was used to monitor the changes in high-energy phosphates. Compared to the hearts arrested with the Ca(++)-free University of Wisconsin solution, the heart arrested with the Ca(++)-containing University of Wisconsin solution showed significantly improved (p < 0.001) contractile functional recovery. No "stone heart" or loss of high-energy phosphates was observed on reperfusion. The hearts showed an increase in diastolic pressure during infusion of the Ca(++)-containing University of Wisconsin solution, however, to show the relationship between the addition of calcium and the increase in diastolic pressure, a second protocol was performed. A 30-minute period of ischemia was induced in thirteen hearts that were arrested at 12 degrees C with either Ca(++)-containing University of Wisconsin solution (n = 8) or Ca(++)-free University of Wisconsin solution (n = 5). Diastolic pressure was monitored during ischemia while ventricular volume was maintained constant with a balloon. The hearts arrested with the Ca(++)-containing University of Wisconsin solution showed a mean rise of 5 mm Hg in diastolic pressure and a rapid decline of phosphocreatine (p < 0.001). Our results suggest that, although 0.08 mmol/L free Ca++ improves functional recovery after 8 hours of heart preservation with University of Wisconsin solution at 12 degrees C, it can increase diastolic pressure during ischemia and accelerate breakdown of the high-energy phosphate stores in the myocardium, suggesting that use of University of Wisconsin solution containing 0.5 mmol/L CaCl2 may result in a significant increase in the intracellular calcium level.

A comparison of UW cold storage solution and St. Thomas' solution II: a 31P NMR and functional study of isolated porcine hearts.

Although University of Wisconsin cold storage solution provides excellent preservation for the pancreas, the kidney, and the liver after extended cold ischemic storage, its ability to preserve the heart for extended cold storage periods is not yet proved. This study was carried out to evaluate the effect of University of Wisconsin solution on heart preservation and to compare it to modified St. Thomas' solution II with respect to the capacity to preserve high-energy phosphates and contractile function in pig hearts. Hearts were arrested with either University of Wisconsin cold storage solution or St. Thomas' solution II (10 ml/kg) and kept ischemic at 12 degrees C or 4 degrees C for 8 hours. Functional recovery after the preservation period was assessed by means of ventricular function curves of the isovolumically contracting Langendorff model perfused with modified Krebs-Henseleit solution. Phosphorus 31 nuclear magnetic resonance spectroscopy was used to monitor high-energy phosphates and intracellular pH during preservation and reperfusion. At 12 degrees C, hearts arrested and preserved with University of Wisconsin solution showed a rapid decrease in phosphocreatine and adenosine triphosphate. With St. Thomas' solution, phosphocreatine and adenosine triphosphate decreased slowly. Functional recovery was poorer with University of Wisconsin solution than with St. Thomas' solution. Hearts preserved at 4 degrees C with either solution showed no significant differences in high-energy phosphate content and functional recovery. Rigorous control of the low temperature (4 degrees C) is necessary when University of Wisconsin solution is used for heart preservation.

Perfluorocarbon-based red blood cell substitutes.

Since our review 5 years ago, a new generation of PFC emulsion has been developed and is undergoing extensive testing. This new generation is the result of the application of physicochemical principles, applied to both the choice of the PFC itself and the emulsifier, as well as advances in emulsion-producing technology. The efficacy of PFCs in general for oxygen transporting capability has been fully recognized, as exemplified by the limited license issued to Fluosol. The latter also represents the recognition of the relative absence of major toxicity of PFCs in general. The development of new products owes much to the lessons learned during the past 20 years and to advances made in the physical chemistry of PFCs. These advances now permit the rational selection or design of the most appropriate PFC and the design of emulsifiers best suited for the purpose. Perflubron represents a clear advance over the Fluosol-DA-type formulation. It is only one but the most advanced of the second-generation products. At least three other commercial entities (Hema-Gen/PFC, Green Cross, Adamantech) are also developing products based on the above principles. Five years ago we concluded that, in spite of the enormous complexity of PFC emulsions as large volume parenterals, they have shown remarkable biocompatibility. The advances in the past 5 years have confirmed this conclusion. The advances occurring during the past 5 years show that the application of the proper technology can lead to product improvement, and that PFC preparations with significant transfusional and nontransfusional potential are, in fact, feasible. It remains to be seen whether high PFC-content emulsion can be successfully deployed in initial, prehospital resuscitation situations. The high PFC content will reduce the absolute requirement for the maintenance of FIO2 > 0.8 in the case of Fluosol-DA for optimal efficacy. The second-generation products also seem to lend themselves to intraoperative use, because they can be removed from the blood postoperatively by plasmapheresislike methods. They are also suitable in combination with autologous blood donation/transfusion. All of these potential applications are in various stages of exploration and, if found to be efficacious, will likely conserve the supply of whole blood and blood components. The nontransfusional applications, particularly those in diagnostic imaging, seem to show substantial promise. Because they involve smaller doses than transfusional applications, they may enter clinical use earlier. The applications in radiation and chemotherapy of malignant diseases represent an intermediate position between the transfusional and nontransfusional uses.(ABSTRACT TRUNCATED AT 400 WORDS)

Nutrition survey of the Hungarian population in a randomized trial between 1992-1994.

OBJECTIVE: Collection of data relating to nutrition, nutrient supply and nutritional status, and to certain risk factors of diet-related diseases in a group of Hungarian population. DESIGN: Collection of data on diets three times 24h dietary recall, anthropometric measurements to obtain information about the nutritional status, laboratory tests measurements of biochemical markers. SUBJECT: Examination of 2559 volunteer adult persons, selected in a quasi random way in Budapest and seven other counties. RESULTS: The diets of the persons examined contained more than necessary protein 14.6 en%, considerably more fat 38.0 en%, mainly fat of animal origin with low PUFA and including high cholesterol, little total carbohydrate 45.1 en%, in that much added sugar 15.4 en%. Vitamin supply was generally satisfactory, borderline deficiency may be observed in the case of tocopherol equivalent and in some age-groups, first of all in women, in the case of thiamine, riboflavin and pyridoxine. Out of the macro- and microelements, sodium intake is three to four times the acceptable level, potassium and calcium intakes in both genders, iron and zinc intakes in women show deficiency. The mean value for relative body mass, the distribution of BMI values prove a high incidence of overweight 34.3% and obesity 21.1%. Means for biochemical markers appear to indicate that nutrient supply was in the normal range of laboratory tests. The averages of total cholesterol and LDL-cholesterol 5.6 and 3.6 mmol/L, respectively unequivocally suggested the risk of cardiovascular diseases. CONCLUSIONS: The nutrition of the Hungarian population presents several risk factors of diet-related diseases: P/S ratio of 0.27-0.29, Na/K ratio of 2.6 g/g, intake of some micronutrients (vitamins, macro- and microelements) was low in certain groups of investigated persons.

Selection of methodology to assess food intake.

OBJECTIVE: The aim of the EFCOSUM project was to develop a method to estimate both acute and usual consumption levels in European countries and for the sake of comparison, a common basic method for dietary assessment was needed. The method should allow a reliable comparison of the intake of relevant dietary indicators among large population groups. DESIGN AND RESULTS: The selection of methodology was based on the available literature and the expertise of the participants. To guide the selection process, decision trees containing all relevant moments of choice, alternatives and criteria for the selection of a method for food consumption measurement were developed. Considering that insight into average food and nutrient intake and their distribution in well-defined groups of individuals was important, it was decided that for the monitoring of the selected dietary indicators food consumption data should be collected at an individual level. Different methods were reviewed (24 h recall, dietary record, food frequency questionnaire, dietary history method). CONCLUSIONS: Since the 24 h recall method is applicable in large European populations of different ethnicity, has a relatively low respondent and interviewer burden, is open-ended and is cost-effective, this method can be considered as the best method for EFCOSUM to get population mean intakes and distributions for subjects aged 10 y and over in different European countries. Usual intake should be estimated by statistical modelling techniques, using two non-consecutive 24 h recalls and a food list to assess the proportion non-users for infrequently consumed foods.

A novel, selective synthetic acetamide containing culture medium for isolating Pseudomonas aeruginosa from milk.

A selective synthetic medium has been developed both in liquid (Z-broth) and solid (Z-agar) forms for selective isolation of Pseudomonas aeruginosa from foods. The simple, easy to prepare peptone-free synthetic medium contained acetamide that is metabolized to ammonia and acetic acid providing nitrogen and carbon supply. The medium contained no inhibitors. Selectivity of the liquid medium was tested by inoculation of pure cultures of different bacteria belonging to the groups Bacillus, Pseudomonas, Enterobacteriaceae and Staphylococcus. It was found that the selectivity of the medium was complete for the examined range of bacteria. However, a similar result was obtained when nitrofurantoin broth was used. Applicability of the synthetic agar medium was also tested by a nation-wide inter-laboratory test using two milk samples containing 10(3)/ml (sample I) and 10(5)/ml (sample II) Pseudomonas aeruginosa. According to this test, no microbiologically relevant differences were found between the results obtained by Z-agar and cetrimide-agar a frequently used selective agar in case of sample II. However, a relevant and statistically significant difference was found in the results of sample I in favour of the Z-agar, that could indicate the presence of a low number of bacteria. Concerning repeatability and reproducibility, Z-agar proved to be superior to cetrimide agar.

Time course of myocardial bloodflow changes during healing of myocardial infarct in pigs.

OBJECTIVE: To define the time course of changes in bloodflow and microsphere content at intervals between one and 28 days after surgical ligation of the circumflex coronary artery. SUBJECTS AND METHODS: After the ligation, pigs were assigned to six groups; all pigs in a group were reanesthetized at either one, three, seven, 14, 21 or 28 days post ligation to determine myocardial bloodflow distribution using radionuclide-labelled (15 +/- 2 microns) microspheres. RESULTS: Bloodflow to the infarct zone, 10 mins post ligation, was 7.3 +/- 1.4% of the normal flow. At one and three days post occlusion, infarct bloodflow was about 50% of the 'normal', declining after day 7 to between 20 and 25%. Bloodflow in the noninfarct zone was significantly elevated during the initial 14 days, declining thereafter to within the normal range. Microspheres in the infarct zone injected prior to the occlusion became concentrated and were diluted in the noninfarct zone; the ratio of infarct:noninfarct microsphere content rose progressively, reaching a 2.5-fold rise by day 28. CONCLUSIONS: The initial stages of infarct healing are associated with a marked rise in bloodflow with a subsequent fall. A more prolonged augmentation of flow is evident in the noninfarct zone. Microspheres are useful in estimating the relative magnitude of changes in the myocardium accompanying the healing (shrinkage) of the infarct and hypertrophy occurring in the noninfarct zone after a coronary occlusion.

The cardiovascular effects of the surfactant pluronic F68 in anesthetized dogs.

We tested the cardiovascular actions of the surfactant Pluronic F68 by infusing it into anesthetized dogs, in doses approximating those which would be received when Fluosol-DA were used to resuscitate moderate or severe hemorrhage (0.66 and 1.11 g/Kg). In order to alleviate the reactions to Pluronic, the surfactant was purified by treatment with activated charcoal and the dogs were pretreated with corticosterone. Pluronic F68 caused dose-dependent increments in cardiac filling pressures and in systemic and pulmonary arterial blood pressure. Heart rate and contractility remained unchanged. There was an increase in the cardiac output which was dose-dependent and unrelated to the filling pressures. Regional blood flow, as determined by radionuclide-labelled microspheres, tended to increase, but only that to the heart, kidney cortex and lung (bronchial arterial) increased to a statistically significant extent. It would appear that Pluronic F68, when purified with charcoal and after steroid prophylaxis, possesses significant hemorheologic and cardiovascular effects, indicating the need for further investigation of various purification methods and the effects of purified preparations.

Oxygen delivery and performance in the isolated, perfused rat heart: comparison of perfusion with aqueous and perfluorocarbon-containing media.

Perfluoro-octylbromide-containing perfusate is capable of supporting the contractile activity of isolated hearts. Because of the high oxygen content of such perfusate, "normal" mechanical function is maintained by such hearts with substantially reduced coronary flow.

Adenosine deaminase in stroma-free hemoglobin solution is not responsible for coronary vasoconstriction.

Erythrocytes contain a high concentration of cytosolic adenosine deaminase and this enzyme activity is present in preparations of stroma-free hemoglobin (SFHS). The documented vasoconstrictor activity of SFHS preparations does not appear to be due to interference with endogenous adenosine-mediated mechanisms, because removal of greater than 80% of adenosine deaminase activity failed to affect the vasoconstrictor potency of SFHS preparations. We have also demonstrated the presence of a contractility-depressant activity in SFHS when the latter was added to aqueous buffer perfusing rat Langendorff-hearts. This activity is diminished in phosphocellulose-purified preparations with reduced adenosine deaminase activity but is not necessarily causally related to this enzyme.

Oxygen binding of modified hemoglobins in solution.

SFHS modified by covalent incorporation of pyridoxal phosphate using NaCNBH3 as reducing agent had P50 values of 21-25mm Hg, and was insensitive to the addition of BPG. The Hill slope of the modified product was 2.34, demonstrating good functional cooperativity of the subunits. Oxygen carrying capacity, calculated as the ratio of O2 content to the concentration of functional hemoglobin, was found to be about 1.3, very close to the "textbook" ratio of 1.34 for whole blood. These values were achieved with oxygen saturation values over 90% and methemoglobin levels of less than 3%. The results obtained from pyridoxalation using NaCNBH3 contrasted sharply with those obtained using NaBH4, which yielded a product having high oxygen affinity and high methemoglobin values. This latter product was poorly saturated with oxygen at ambient pressures and demonstrated a significantly lowered oxygen carrying capacity. The NaBH4 product was also insensitive to the addition of BPG; the reason for this was not ascertained. SFHS-P by the borohydride method thus exhibited marked deficiencies relative to that prepared with cyanoborohydride, as defined by the characterizations employed for this study.

Stroma-free hemoglobin solutions prepared by crystallization and ultrafiltration methods; comparison of composition and coronary vasoconstrictor potency.

Stroma-free hemoglobin solutions (SFHS) were prepared by the crystallization and ultrafiltration methodologies. The preparations were partially characterized with respect to their effects upon the isolated perfused rat heart. SFHS prepared by ultrafiltration is characterized by a substantially lower content of residual membrane phospholipid and a more restricted protein composition. This preparation is also essentially free of vasoconstrictor and contractility-depressant actions on the ex vivo perfused heart. In contrast, crystallization-produced SFHS is less well purified of both phospholipid and protein constituents, is likely to generate denatured protein aggregates during storage and exhibits vasoconstrictor and contractility-depressant activity which may vary significantly, from batch to batch. These findings indicate that preparative methodology based on ultrafiltration and size-exclusion, yields SFHS which is superior in these respect to that produced by a crystallization method.

The effects of activated complement on myocardial performance in vitro.

Activated complement has been implicated in the dysfunction of several organ systems, but can it directly affect the myocardium? This possibility was studied using human right atrial trabeculae contracting isometrically "in vitro" in four solutions: Tyrode's (T), autologous arterial blood (B), plasma (P) and denaturated plasma (DP). Complement was activated by the addition of Zymosan while vehicle alone was used as control. Complement activation occurred in the blood and plasma solutions, as assessed by a significant drop in CH50 (p less than 0.05), while there was no detectable complement activity in either T or DP. Myocardial functional integrity was assessed by the change in contractile parameters with time. Subsequent resting forces, relative developed forces (DF), and rates of decay of DF were similar between muscles contracting in the four solutions. We conclude that activated complement has no direct effect on myocardial performance.