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Biomedical subjects

O Simonsen

Publications and source records attributed to O Simonsen.

At least 19 recordsLinked to original sources
PubMed1996

Fall-off in immunity following diphtheria revaccination--an 8 year follow-up study.

Diphtheria may occur even among previously vaccinated persons and knowledge of the duration of immunity is of crucial importance when designing effective vaccination programmes. In a follow-up study of 42 representative probands revaccinated 8 years previously, a continuous fall-off in antitoxic immunity was demonstrated. 98% were still protected (antitoxin concentration > 0.01 IU/ml). From the distribution of titres in the group the individual risk of susceptibility 8 years after revaccination was calculated to be 0.8/1000 (0.2-2.9/1000, 95% confidence limits). Thus, repeated revaccinations are required to secure continuous protection. The fall-off pattern for diphtheria antitoxin was approximately the same as for tetanus antitoxin. Peak values following revaccination are decisive for the duration of immunity. As peak values following vaccination depend on naturally acquired immunity and consequently decrease as indigenous diphtheria in a population disappears, highly potent vaccines are required to secure long-term immunity following diphtheria revaccination. The effects of dose and adjuvant are discussed.

Adult↗
PubMed1996

Transport of tracer albumin from peritoneum to plasma: role of diaphragmatic, visceral, and parietal lymphatics.

Using a technique to acutely seal off various parts of the peritoneal membrane surface, with or without evisceration, we investigated the role of diaphragmatic, visceral, and parietal peritoneal lymphatic pathways in the drainage of 125I-labeled albumin (RISA) from the peritoneal cavity to the plasma during acute peritoneal dialysis in artificially ventilated rats. The total RISA clearance out of the peritoneal cavity (Cl) as well as the portion of this Cl reaching the plasma per unit time (Cl--> P) were assessed. Under non-steady-state conditions, the Cl was fivefold higher than the Cl--> P. Evisceration caused a 25-30% reduction in both Cl--> P and Cl. Sealing of the diaphragm, however, reduced the Cl--> P by 55% without affecting the Cl. A further reduction in the Cl--> P was obtained by combining sealing of the diaphragm with evisceration, which again markedly reduced the Cl. However, the greatest reduction in the Cl was obtained when the peritoneal surfaces of the anterior abdominal wall were sealed off in eviscerated rats. The discrepancy between the Cl and the Cl--> P can be explained by the local entrance of fluid and macromolecules into periabdominal tissues, where fluid is rapidly absorbed through the capillary walls via the Starling forces, while macromolecules are accumulating due to their very slow uptake by tissue lymphatics under non-steady-state conditions. Of the portion of the total Cl that rapidly entered the plasma, conceivably by lymphatic absorption, 55% could be ascribed to diaphragmatic lymphatics 30% to visceral lymphatics, and only some 10-15% to parietal lymphatics.

Animals↗
PubMed1996

Less infusion pain and elevated level of cancer antigen 125 by the use of a new and more biocompatible PD fluid.

Our objective was to investigate the clinical effect of a less toxic and less acidic peritoneal dialysis (PD) fluid produced in a two-compartment bag (PD-Bio). The study had an open cross-over design in 4 stable patients, where the patient served as his/her own control. After a period of three months using conventional PD fluid the patients were switched to three months on the new PD fluid. Routine blood chemistry and transport characteristics were measured. Cell samples from overnight spent dialysis fluid were analyzed for viability, differential count, release of superoxide radicals, and cancer antigen 125 (CA 125). Subjective patient symptoms and handling properties were investigated by a patient questionnaire. Cancer antigen 125 increased significantly, and patients with discomfort or infusion pain during the control period improved during the PD-Bio period. Patient acceptance with respect to handling of the two-compartment bag was excellent and did not differ from the use of standard bags. No changes were seen in the cell samples from spent dialysate, blood chemistry, or transport characteristics between the two treatment periods. PH in the effluent dialysate was, however, significantly higher for PD-Bio at all times during the two-hour dwell. Our results suggest that a PD fluid produced to minimize the level of toxic glucose degradation products and to obtain a more physiological pH has an impact on CA 125 levels, reduces pain and discomfort in connection with infusion of fluid, and does not influence the transport characteristics.

CA-125 Antigen↗
PubMed1995

Subcutaneous epoetin beta in renal anemia: an open multicenter dose titration study of patients on continuous peritoneal dialysis.

OBJECTIVE: To establish dose requirements (target hemoglobin > 100 g/L) and safety of subcutaneously administered epoetin beta. DESIGN: Open multicenter study. PATIENTS: Forty-five anemic patients (21 female, 24 male; mean age 55 years; range 20-79 years) who had been on continuous peritoneal dialysis for 1-157 months (mean 24 months). Thirty patients required blood transfusions during the year prior to the study. Mean hemoglobin concentration pretreatment was 75 g/L (range 57-89 g/L). INTERVENTION: After a pretreatment period of two weeks, 60 IU kg-1 week-1 divided into three weekly doses of epoetin beta was administered subcutaneously. The dose was increased by 60 IU kg-1 week-1 after ten weeks, and when necessary, every fourth week in patients with hemoglobin levels below 100 g/L. MAIN OUTCOME MEASURES: Hemoglobin concentration. Analysis of factors affecting the response to epoetin beta. Safety of epoetin beta. RESULTS: Thirty-eight of the 45 patients completed six months and 21 patients completed one year in the study. Twenty-six patients reached hemoglobin 100 g/L within six months and 8 patients did later on. The mean hemoglobin concentration after three months was 93 g/L (range 64-144 g/L) and after six months was 99 g/L (range 59-130 g/L; mean epoetin beta dose 122 IU kg-1 week-1). During the second six-month period of the study, hemoglobin levels were stable in most patients. After one year, the mean hemoglobin was 110 g/L (range 84-153 g/L) and the mean epoetin beta dose was 107 IU kg-1 week-1. Prolonged correction time and impaired response to epoetin were observed in patients with infections or hemorrhages and in patients with low hemoglobin concentration before starting epoetin treatment. Iron deficiency was controlled by iron supplementation, either orally or, in 10 patients, intravenously. Increased blood pressure, requiring intensified antihypertensive treatment, was observed in 13 patients. CONCLUSIONS: Continuous peritoneal dialysis patients with moderate anemia (Hb 75-90 g/L) and without complicating disorders can be managed with subcutaneous doses of epoetin < 120 IU kg-1 week-1. The epoetin beta dose should be adjusted after the first month of treatment since most patients required higher doses than the initial 60 IU kg-1 week-1.

Anemia↗
PubMed1993

The effect of high-dose pyridoxine and folic acid supplementation on serum lipid and plasma homocysteine concentrations in dialysis patients.

Pyridoxine and folic acid supplementation in dialysis patients is a matter of debate. This study was performed to estimate the effects of pharmacologic doses of these vitamins on serum lipid and plasma homocysteine concentrations, which are known to be high in dialysis patients. Both hemodialysis and continuous ambulatory peritoneal dialysis patients were included in the study. Pyridoxine supplementation had a mild but significant cholesterol-lowering effect (7%). Folic acid supplementation significantly lowered plasma homocysteine concentrations by a mean of 30%. There was a strong, inverse correlation between blood folate and plasma homocysteine concentrations. These results indicate that daily supplementation with pyridoxine 300 mg and folic acid 5 mg has a beneficial effect on the cardiovascular risk profile in dialysis patients.

Adult↗
PubMed1991

Reinforced anatomical reconstruction of the anterior talofibular ligament in chronic anterolateral instability using a periosteal flap.

Twenty-eight consecutive ankles with chronic severe lateral instability were treated by reinforced anatomic reconstruction using a periosteal flap from the lateral aspect of the fibula. At the followup after a median of 24 months, 86% had excellent or good functional results. This result compares favorably with other techniques. As the results after tenodesis appear to deteriorate with time, anatomic reconstruction is recommended. No complications were encountered. No statistical correlation was found between clinical and radiological versus functional instability at followup.

Adolescent↗
PubMed1991

Muscle coordination following rupture of the anterior cruciate ligament. Electromyographic studies of 14 patients.

In an electromyographic (EMG) study, the coordination in muscles acting on the knee joint was assessed in 14 patients with an arthroscopically verified complete rupture of the anterior cruciate ligament and in 16 controls. EMG and heel-contact signals were recorded while walking on a treadmill at walking gradients from 0 to 25 percent. There was an earlier onset of EMG bursts in the patients, especially in the lateral hamstrings and medial gastrocnemius; and the duration of EMG bursts also tended to be prolonged in the patients. Normalized root mean squares of amplitudes, which correlate with muscle tension, were higher in the gastrocnemius in the patients. EMG profiles, outlining the averaged muscle activity throughout the gait cycle, showed a displacement of peak activity in the hamstrings from the late swing phase into the stance phase, with increasing gradients in both the patients and the controls. Our study indicates that the gastrocnemius muscle contributes to functional stability in the anterior cruciate ligament deficient knee, and more attention should be paid to this muscle.

Adult↗
PubMed1991

Clinical implications of a three-pore model of peritoneal transport.

The peritoneal barrier exchange characteristics are in this article described in terms of a three-pore model of membrane permselectivity. The peritoneal membrane during continuous ambulatory peritoneal dialysis (CAPD) is thus simulated to have a large number of small pores of radius 40-55 A, a small number of large pores of radius 200-300 A, and an abundance of transcellular pores of radius 4-5 A. Due to the heteroporous nature of the peritoneal membrane, peritoneal small solute sieving coefficients are of the order of 0.5-0.6, and not near unity, as predicted for a homoporous membrane having 50 A (radius) equivalent pores, but lacking transcellular pores. As a consequence, the dialysate during CAPD is diluted during the first 50-100 minutes of the dwell. Furthermore, there is a marked coupling between the increased net transperitoneal volume flow, occurring early in the cycle, and the transfer of "small" macromolecules, such as beta 2-microglobulin and albumin, across the peritoneal membrane. This coupling is, however, small for "large" macromolecules, such as IgG and IgM, or for small solutes. Increasing the peritoneal surface area, in computer simulations of peritoneal transport according to the three-pore model, causes the simulated intraperitoneal (i.p.) volume vs. time (V(t)) curves to peak earlier than during control, while the maximum volume ultrafiltered is not markedly affected. However, selectively increasing the glucose PS (mass transfer area coefficient) causes a reduction both in the peak time and the peak "height" of the V(t) curves. The latter pattern is also seen when the dialysate volume is reduced. It is concluded that a three-pore model of membrane permselectivity selectivity can adequately describe the kinetics of peritoneal transport of small and large solutes and of fluid.

Ascitic Fluid↗
PubMed1990

Chyluria treated with renal autotransplantation: a case report.

We report a rare case of chyluria in a patient from an area not endemic to filariasis. Initial surgical treatment consisted of stripping of the renal pedicle, following which the patient was free of symptoms for 3 months. Recurrence was noted and renal autotransplantation was performed. Chyluria has not recurred 12 months after the second operation. The etiology and various treatments of chyluria are discussed.

Adult↗
PubMed1989

A long-term follow-up of the effect of repeated corticosteroid injections for stenosing tenovaginitis.

Ninety-three consecutive adult patients with stenosing tenovaginitis of 104 digits have been treated by corticosteroid injections repeated at three week intervals up to thrice in partial responders. At follow-up after 3-15 years, partial relapse had occurred in two patients, who now and then experienced triggering but without pain or locking. Complete relief of symptoms was obtained in 76%. There were no complications and the success rate was independent of sex, age, duration of symptoms, the digit involved, or associated diseases. These results are superior to those previously reported following a single injection.

Adult↗
PubMed1989

Systemic administration of N-acetylcysteine has no effect on postoperative lung function following elective upper laparotomy in lung healthy patients.

In a randomized, double-blind study, 131 consecutive patients, subjected to elective upper laparotomy, were prophylactically given the recommended dose of N-acetylcysteine (NAC) (Mucomyst, ASTRA) (200 mg x 3) or placebo against postoperative pulmonary complications. The effect was evaluated by lung function tests (VC and FEV1), arterial blood gas analyses and chest x-ray. No benefit could be demonstrated, either to postoperative pulmonary function or in the frequency of atelectasis in the recommended dose. However, no patients with preoperative bronchopulmonary disease demanding treatment with bronchodilatators were included in the study. A positive effect of NAC in this category of patients could not be excluded.

Acetylcysteine↗
PubMed1989

Peroral N-acetylcysteine as prophylaxis against bronchopulmonary complications of pulmonary surgery.

In a randomized, double-blind study, 38 patients undergoing elective pulmonary surgery were given N-acetylcysteine (Fabrol, Ciba-Geigy) in recommended dosage (200 mg X 3) or placebo. The prophylactic effect on postoperative bronchopulmonary complications was evaluated from arterial blood-gas analyses and chest radiography. The alveolo-arterial oxygen difference increased substantially and similarly in both patient groups, and no intergroup difference was found in incidence of atelectasis or pneumonic infiltration. Thus there was no demonstrable benefit of N-acetylcysteine in the recommended dosage. For future similar studies, employment of considerably higher doses is proposed.

Acetylcysteine↗
PubMed1988

Immunity against diphtheria and tetanus in the age group 30-70 years.

In Denmark, childhood primary vaccination against diphtheria and tetanus has been recommended since 1950. No routine revaccinations or general vaccination of adults have been offered. In most other western countries revaccinations are recommended later in childhood. However, death still occurs from diphtheria and tetanus in countries with such vaccination programs although it is generally accepted that protective immunity can be obtained by vaccination. On this basis the immunity against diphtheria and tetanus was assessed in a random sample of 351 subjects in the age range 30-70 years. Diphtheria antitoxin titres were determined by in vitro neutralization technique using VERO cells. 26% had diphtheria antitoxin titres below protective level (0.01 international antitoxin units/ml serum). The highest number of unprotected against diphtheria was found among 30-39 year old women (68%) and 60-69 year old subjects (36%). Tetanus titres were determined by a combination of ELISA technique and an in vivo neutralization assay. 51% were unprotected against tetanus (less than 0.01 international antitoxin units/ml serum). The highest number of unprotected against tetanus was found among 60-69 year old subjects (68%) and especially among females in this age group (77%). To avoid epidemics of diphtheria in the future the immunity among adults must be raised within the coming years. Thus, revaccination must be recommended and high attendance ensured. One revaccination is sufficient only when complete primary vaccination is documented.

Adult↗
PubMed1988

Plasmapheresis and haemodialysis in a case of septic cholangitis complicated by hepatic and renal failure. Case report.

Plasmapheresis was used as a complement to conventional therapy in a patient with multiorgan failure and disseminated intravascular coagulation (DIC) following biliary obstruction and septic cholangitis. The patient's remarkable improvement after plasmapheresis suggests a beneficial influence on the pathophysiologic mechanisms. Plasmapheresis is concluded to inhibit DIC and eliminate endotoxins.

Aged↗