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Biomedical subjects

A Bengtson

Publications and source records attributed to A Bengtson.

At least 19 recordsLinked to original sources

Activation of the complement cascade by trypsin.

In twenty-three patients with acute pancreatitis, the plasma levels of immunoreactive trypsin were determined with a RIA method. The patients were divided into groups according to the severity of the disease. Ranson's criteria and the development of multisystem organ failure were used for the classification. Elevated plasma levels of immunoreactive trypsin were found in all groups after admittance. Incubation of fresh human serum and plasma with bovine trypsin in concentrations between 10(-6) and 10(-4) M at 20 degrees C activated the complement cascade. The anaphylatoxins C3a and C5a were determined with a RIA and the terminal complement complex (TCC) with an ELISA method. C3a and C5a were released and TCC was formed. The effect of trypsin on leukocyte activation was determined with a chemiluminescence technique. Trypsin dissolved in saline did not activate the leukocytes. However, serum digested by trypsin-activated leukocytes in a dose-dependent manner. The present study supports the theory that trypsin can activate complement components and results in formation of split products which have potent vascular, and leukocyte activating effects.

Acute Disease

Long-term follow-up of health-related quality of life in patients with suspected acute myocardial infarction when the diagnosis was not confirmed.

This study describes the outcome in terms of health-related quality of life (QL) five years after onset of symptoms in 397 patients with an initial suspicion of acute myocardial infarction (MI) but in whom the diagnosis was not confirmed. The patients were approached by means of a postal inquiry that comprised two questionnaires. The most pronounced impairment in health-related QL was expressed as decreased energy, whereas social life was the least affected area. The overall QL was very similar to that in patients who had a confirmed MI. Subsets of patients with impaired QL were those given the diagnosis of angina pectoris or possible infarction.

Acute Disease

Anaphylatoxin generation in acute pancreatitis.

Fifty-one patients with elevated serum amylase and clinical signs of acute pancreatitis were studied prospectively. The concentrations of anaphylatoxins (C3a and C5a) were measured with a radioimmunoassay and the activity of their inactivator was determined. The pancreatitis was classified as mild, moderate, or severe according to Ranson's 11 signs, appearance of peritoneal fluid, and development of multisystem organ failure (MSOF). Plasma C3a and C5a concentrations were elevated during attacks of acute pancreatitis. Anaphylatoxin levels correlated with the severity of the disease (C3a, P less than 0.001; C5a, P less than 0.05). The highest and most persistent levels were found in the group with MSOF. C3a levels decreased rapidly during recovery. In patients with complications like abscess or pseudocyst, the C3a elevation persisted until adequate treatment was instituted. In this study, no significant changes of the inactivator levels were found, except at discharge when the inactivator level of the severe group was elevated compared to that of the moderate and mild groups (P less than 0.05).

Acute Disease

Altered concentrations of terminal complement complexes, anaphylatoxins, and leukotrienes in the coronary sinus during cardiopulmonary bypass.

The aim of this study was to determine if the hypoperfused heart activates complement with formation of anaphylatoxins, terminal complement complexes (TCC), or leukotrienes during cardiopulmonary bypass. Fifteen patients undergoing elective cardiopulmonary bypass surgery were studied regarding complement and leukotriene activation. Blood samples were drawn serially from the radial artery and coronary sinus. The plasma concentrations of the complement components C1INH, C3, C4, and C5 decreased during the procedure, whereas C3a and TCC increased. Protamine reversal of heparin further increased the plasma levels of C3a and TCC. No significant changes in plasma levels of C5a and leukotriene C4 were observed during cardiopulmonary bypass. The activity of the anaphylatoxin inactivator (AI) decreased in both the radial artery and the coronary sinus. There were no significant differences between the concentrations of complement components and leukotriene C4 in blood from the radial artery and coronary sinus. The levels of C3a and TCC increased and C1INH, C3, C4, C5, and the anaphylatoxin inactivator activity decreased to the same extent in the coronary sinus and the radial artery. Thus, the heart does not appear to be the primary site for the altered concentrations of these endogenous vasoactive substances.

Aged

The circle system as a humidifier.

In a laboratory model, humidity output was investigated in relation to the design of a circle absorber system. A 70-kg subject was simulated with fresh gas flows of 0.5, 2 or 5 litre min-1. Different circle systems, absorption canisters and tubings were studied. It was found that both the type of circle system (according to Eger's classification) and the size of the absorption canister, influenced the humidity of inspired gases. Coaxial tubing only moderately increased the humidity. If a fresh gas flow of 0.5 liter min-1 was used, optimum moisture contents were attained, irrespective of the circle system tested. Low fresh gas flows, a small canister and an Eger A type circle system, were factors which increased humidification.

Absorption

Humidity of the Bain and circle systems reassessed.

The humidity outputs of the Bain circuit, a traditional non-coaxial Mapleson D system, and a circle system with and without a soda lime absorber were evaluated in a laboratory model simulating a 70-kg subject. The breathing systems were tested with tidal volumes of 0.35 and 0.70 L and frequencies of 10-20 breaths/min to maintain an end-expiratory CO2 of 4.5%. There were small differences in inspiratory gas humidity between the Bain and the non-coaxial Mapleson D system. With a fresh gas flow of 5 L/min in the Bain circuit, the humidity was 9.8-16.5 mg H2O/L depending on tidal volume and respiratory frequency. The humidity output of the circle absorber system with fresh gas flows of 0.5 or 2 L/min was 21.6-25.2 mg H2O/L at 60 min. Therefore, this study does not support previous studies, which propose that the Bain circuit has superior humidifying properties compared with those of the circle absorber system.

Anesthesiology

Complement activation and anaphylatoxin (C3a and C5a) formation in preeclampsia and by amniotic fluid.

The aim of this study was to determine whether the biologically active complement peptides C3a and C5a are formed in pregnancy and whether amniotic fluid can activate complement. C3a and C5a are formed when complement is activated. They increase smooth-muscle contraction, vascular permeability, and histamine release from mast cells and basophils. Thirty pregnant women were studied, 16 with uncomplicated and 14 with preeclamptic pregnancies. The plasma C3a and C5a concentrations before delivery were significantly higher in the preeclamptic than in the normal group. The concentrations returned to normal within 1 week. Plasma, serum, and amniotic fluid from 12 pregnant women (eight uncomplicated and four preeclamptic pregnancies) were drawn in connection with delivery. Amniotic fluid was incubated in fresh autologous serum at 37C for 15 minutes. A dose-dependent formation of C3a and C5a was registered with increasing amounts of amniotic fluid.

Adult

Terminal complement complexes and anaphylatoxins in septic and ischemic patients.

Terminal complement complex (TCC) and anaphylatoxin formation in 18 patients with sepsis and 20 patients with acute limb ischemia were studied before the start of treatment and seven days later. The septic or ischemic patients had elevated levels of plasma TCC before start of therapy. In successfully treated patients these concentrations were within the normal range one week later. Similarly, the plasma anaphylatoxin level was increased before therapy and returned to the normal range within seven days. Escherichia coli incubated in vitro in fresh human serum at body temperature started formation of TCC in a dose-related manner. As complement will induce cellular lysis via TCC and edema via anaphylatoxins, anemia and impaired respiration in these patients may be influenced by increased concentrations of terminal complement complexes and of C3a and C5a.

Aged

Anaphylatoxin formation in sepsis.

Complement activation and anaphylatoxin formation were studied in 27 septic patients. The patients were treated with antibiotics and high-dose corticosteroids. Blood samples were drawn on admission and every week thereafter. Plasma levels of complement components C1INH, C3, C4, and C5 were low before the start of treatment but were above normal one week later in both successfully and unsuccessfully treated patients. In contrast, plasma levels of anaphylatoxins C3a/C3adesArg and C5a/C5adesArg were elevated on admission. After successful treatment, plasma levels of C3a/C3adesArg and C5a/C5adesArg returned to normal within one week. Nine patients had ongoing sepsis one week after the start of treatment and a persistent rise in anaphylatoxin concentration. They developed multisystem organ failure with respiratory, hepatic, and renal insufficiency. In vitro studies of Escherichia coli incubation in fresh serum indicated a dose-related formation of C3a/C3adesArg and C5a/C5adesArg. High concentrations of methylprednisolone inhibited the anaphylatoxin formation in vitro.

Adult

Morbidity during five years after myocardial infarction and its relation to infarct size.

In 809 patients with a recent myocardial infarction, morbidity during 5-year follow-up was assessed. The overall 5-year mortality rate was 33% (39% in patients with larger infarcts and 26% in patients with smaller infarcts) as judged from maximum serum enzyme activity (p less than .001). In terms of morbidity, no significant association with estimated infarct size was observed. Patients with smaller infarcts tended to have a higher reinfarction rate and were rehospitalized more often, whereas a similar proportion of patients with large and small infarcts developed stroke. Among survivors, chest pain tended to be more common in patients having smaller infarcts, whereas symptoms of dyspnea and claudicatio intermittens were similar in both groups, as were smoking habits, work capability, and varying forms of medication. We thus conclude that during a 5-year follow-up after acute myocardial infarction, mortality, but not morbidity, was related to the original infarct size.

Electrocardiography

Occurrence of hypokalemia in suspected acute myocardial infarction and its relation to clinical history and clinical course.

In 1350 patients with suspected acute myocardial infarction, serum potassium levels during the first 3 days in hospital was correlated to clinical history and clinical course. A higher incidence of hypokalemia was observed in women, in patients with hypertension, and in those on chronic diuretic treatment. Patients with anterior infarction had a higher incidence of hypokalemia than those with inferior infarction, as did patients with large as compared with small infarcts. No clear difference was observed between patients whose infarction was confirmed and those in whom the diagnosis was not confirmed. Independent predictors for hypokalemia were treatment with diuretics before admission to hospital, infarct size, and female sex. Hypokalemia during the first 3 days of hospitalization was associated with the occurrence of severe ventricular arrhythmias during hospitalization, but not with survival during a 5-year follow-up.

Female

Body temperature in acute myocardial infarction and its relation to early intervention with metoprolol.

In a subsample of 223 patients participating in a double-blind trial with metoprolol in suspected acute myocardial infarction, body temperature during the first 5 days in hospital was recorded. Patients developing infarction had a mean temperature of 37.3 degrees C compared with 36.8 degrees C for those with no infarction (P less than 0.001). A positive association was observed between enzyme-estimated infarct size and body temperature (P less than 0.001). Patients given metoprolol had a mean temperature of 37.0 degrees C as compared with 37.2 degrees C in those given placebo (P = 0.03). The most marked difference between metoprolol and placebo was observed among those treated very early. We conclude that early treatment with metoprolol in suspected acute myocardial infarction appears to lower body temperature during the following days. This might reflect limitation of the infarct size.

Adult

5-year mortality rate in patients with suspected acute myocardial infarction in relation to early diagnosis.

In 1,395 patients admitted to hospital between 1976 and 1981 due to suspected acute myocardial infarction, the 5-year mortality rate was related to whether they developed infarction or not during the first 3 days. In all, patients with definite myocardial infarction had a 5-year mortality rate of 33.4% as compared with 13.3% in patients not fulfilling the criteria for this diagnosis (p less than 0.001). When separately analyzing patients with no previous myocardial infarction before admission and discharged from hospital, the corresponding mortality rate was 24.1% for myocardial infarction patients versus 8.1% in nonmyocardial infarction patients (p less than 0.001). Among all patients with nonconfirmed myocardial infarction, those who partly fulfilled the criteria (possible myocardial infarction) had a 5-year mortality rate of 16.7% as compared with 12.0% in those in whom myocardial infarction was completely ruled out (p = 0.18). Independent risk factors for death among patients not developing early infarction were high age and a clinical history of previous myocardial infarction and smoking. We conclude that in this study the long-term prognosis among patients admitted to hospital due to suspected acute myocardial infarction was clearly related to whether they developed an infarction or not during the first 3 days in hospital.

Double-Blind Method

Morbidity and quality of life 5 years after early intervention with metoprolol in suspected acute myocardial infarction.

In 1,395 patients in the age range 40-74 years participating in a double-blind trial with metoprolol in suspected acute myocardial infarction morbidity and quality of life were assessed during the first 5 years after randomization. During the first 3 months patients were given 200 mg metoprolol daily or placebo. Thereafter the two groups were treated similarly. Mortality during 5 years was 24.2% in patients originally randomized to metoprolol versus 25.7% in patients originally randomized to placebo (p greater than 0.2). No difference was observed regarding reinfarction rate, stroke or occurrence of bypass surgery during the 5-year follow-up. During the first 3 months 10% of patients in the metoprolol group were rehospitalized for various reasons versus 13% in the placebo group. The corresponding figures for 5 years were 59 and 60%, respectively. Among patients surviving 5 years 84% in both groups were on some medication of which beta-blockade was the dominating one. Symptoms of chest pain, dyspnea, claudicatio, smoking habits and working capacity did not differ and neither did quality of life according to the Nottingham Health Profile. We thus conclude that morbidity and quality of life were not significantly affected 5 years after early intervention with metoprolol in patients with suspected acute myocardial infarction.

Adult

Inhibition of complement activation by high-dose corticosteroids in total hip arthroplasty.

Anaphylatoxins are released during total hip arthroplasties (THA) when methylmethacrylate is used. These toxins may be responsible for hemodynamic and pulmonary instability during surgery. Recent studies have shown that the release of anaphylatoxins may be inhibited by high-dose corticosteroids (HDC). In a double-blind study 30 consecutive patients with osteoarthritis or failed hip fractures were randomized into two groups; 15 patients received HDC at the beginning of the operation and 15 patients, designated the control group, received infused saline. Anaphylatoxin formation, arterial oxygen tension, and blood pressure were determined preoperatively, during the operation, and one day postoperatively. The patients who received HDC had no significant alteration regarding the anaphylatoxins or arterial oxygen tension during surgery. However, in the control group elevated C3a levels and decreased PaO2 levels were found. Corticosteroids therefore inhibit complement activation and anaphylatoxin release in hip arthroplasty surgery.

Aged