Biomedical subjects

P Christensen

Publications and source records attributed to P Christensen.

At least 145 records · Page 8Linked to original sources

PubMed1986

Effect of a strict preoperative hygienic routine on the rate of infections following cesarean section.

The frequency of postoperative infections after cesarean section was studied during two periods. In the first period no strict preoperative hygienic routines were applied; 321 patients were delivered by cesarean section during this period. In the next period strict hygienic routines were introduced; this period included 337 patients. The infection rate was significantly reduced during the second period from 20% to 16%. This reduction was found among the elective operations, and among parturients who had been treated in the hospital for more than 24 h prior to delivery. The frequency of endometritis decreased significantly from the first to the second period, whereas no difference was found concerning wound infections. Significantly fewer patients contracted septicemia during the second period. Since all septicemia cases occurred in endometritis patients the results might indicate that not only the number of patients contracting infection but also the severity of the infections was reduced. No reduction of infections was found after emergency operations. Antibiotic prophylaxis might therefore be of value in this group of patients.

Bacterial Infections↗

PubMed1986

The effect of intravenous immunoglobulin treatment in recurrent acute otitis media.

The effect of serial intravenous infusion of human immunoglobulin on the frequency of acute otitis media (AOM) episodes and on other upper respiratory tract infections was prospectively studied in a group of 22 otitis-prone children, 1-4 years old. After pair-matching, the children were allocated to immunoglobulin treatment or to a control group. Increased specific IgG antibody activities against pneumococcal types associated with recurrent AOM (rAOM) were generally achieved, but no significant difference was noted in the frequency of AOM attacks or other respiratory tract infections between the immunoglobulin-treated children and their pair-matched untreated controls. The results indicate that, although serum antibody activities against bacteria associated with AOM are increased by immunoglobulin infusions, this does not prevent the development of AOM in children suffering from rAOM.

Acute Disease↗

PubMed1986

Benzodiazepine suppression of cortisol secretion: a measure of anxiolytic activity?

Clinical studies on spontaneous afternoon cortisol levels in depressed patients revealed that oxazepam given a few hours before blood sampling, may suppress the cortisol levels. This was confirmed in a volunteer study, where oxazepam 30 and 60 mg caused a dose-dependent suppression of the cortisol level only lasting 2 or 3 hours in spite of persisting high oxazepam levels in plasma. Subsequently, a study in 28 depressed patients showed a substantial suppression of afternoon cortisol after oxazepam 45 mg given 2 hrs prior to sampling. It may be postulated that this effect is mediated through GABA-ergic receptors inhibiting the hypothalamic release of corticotropin releasing factor (CRF). This is interesting since CRF may have neurotropic effects related to the behavioral responses to stress, and the inhibitory effect thus may represent a mechanism of action for the anxiolytic effect of benzodiazepines.

Adrenocorticotropic Hormone↗

PubMed1986

Monoclonal opsonic mouse antibodies specific for streptococcal IgG Fc-receptor.

Spleen cells from mice immunised with group-A type-M15 streptococci and boosted with purified IgG Fc-receptor (FcR) from this type were fused with Sp 2/0 mouse myeloma cells. The resulting hybridomas were screened by ELISA for antibody production. Two IgM-secreting cell lines were selected. The monoclonal antibodies and ascites fluids inhibited the binding of 125I-labelled human IgG and IgG Fc-fragments to group-A type-M15 streptococci. The monoclonal antibodies also displaced purified FcR towards the anode in electrophoresis. They opsonised group-A type M-15 streptococci for phagocytosis by human granulocytes in the presence of fresh human serum. It was concluded that FcR is important for group-A streptococcal virulence.

Animals↗

PubMed1986

Repeatability of the single-breath method for estimation of pulmonary blood-flow: comparison among four data-reduction procedures.

The single-breath method of Kim, Rahn and Farhi (1966) enables the estimation of the pulmonary blood-flow from the PCO2 vs. PO2 curve recorded during a prolonged expiration. Studies on the repeatability of the method have given very different results. At one extreme the estimated pulmonary blood flows ranged from -47 to 173 litre/min and at the other extreme the repeatability was found to be better than that usually reported for invasive methods. A possible explanation for these important differences is the use of different data-reduction procedures to calculate the pulmonary blood-flow from the measured PCO2 and PO2 values. In the present study we have investigated the repeatability of the single-breath method in 20 test subjects using four previously published data-reduction procedures. Furthermore, we have studied the sensitivity of the estimated pulmonary blood-flow to measurement noise for each of the four data-reduction procedures, by using a previously described technique based on computer simulations. Three of the data-reduction procedures gave standard deviations on repeated single determinations of the pulmonary blood-flow of about 1 litre/min whereas the last method gave results which fluctuated wildly from one determination to the next. The simulation showed that about 1/3 of the random variations can be ascribed to the measurement noise in PCO2 and PO2.

Adolescent↗

PubMed1986

The effect of serial intravenous immunoglobulin infusion on type-specific anti-pneumococcal antibodies in children.

The effect of a series of five immunoglobulin G infusions--at 3-4 week interval--on serum IgG antibody concentrations against some pneumococcal types commonly associated with acute otitis media (AOM) was studied in 11 children, 1-4 years old, suffering from recurrent AOM. Increase of specific IgG antibody concentrations was observed when the initial concentrations were low. However, once higher antibody concentrations had been achieved as a result of the treatment, subsequent infusions resulted in a decrease of the antibodies. In two children with initially high specific antibody concentrations, antibodies successively decreased in response to repeated immunoglobulin infusions.

Antibodies, Bacterial↗

PubMed1986

Independent binding of native and aggregated IgG in group A streptococci.

Irrespective of IgG Fc-receptor activity, earlier characterized, many group A streptococci were recently found to bind aggregated IgG Fab and/or light chains. In the present study, binding of glutaraldehyde-aggregated, radiolabelled, intact human IgG (a*IgG) to group A streptococci was tested, and strains representing several M-types were found reactive. In particular, high binding was observed among type M12 strains, earlier found devoid of Fc-receptors for monomeric IgG; accordingly, unlabelled, native IgG had little influence on the binding. The sites binding a*IgG were highly sensitive to trypsin and relatively resistant to heat treatment. The binding to M12 was inhibited by human fibrinogen and, to a lesser extent, by heat-aggregated serum albumin. Rabbit antiserum to M12 was more inhibitory than antiserum to a heterologous type of group A streptococci or normal rabbit serum. Our results indicate that streptococcal M-protein binds a*IgG by a multipoint requiring interaction of low specificity and that previously described Fc-receptors binding native IgG are not involved. For comparison, in Cowan I staphylococci and one strain of group G streptococci tested, high binding of a*IgG was also observed; however, this binding was inhibited by native IgG, indicating that protein A and group G streptococcal Fc-receptor, earlier known to bind untreated IgG, also bound a*IgG.

Binding Sites, Antibody↗

PubMed1986

Repeated passage of freshly isolated group A streptococci on blood agar. II. Effect on adherence capacity.

Group A streptococcal strains (three T-type 1, two T-type 2 and three T-type 4), freshly isolated from throat cultures, were subjected to 25 serial passages on blood agar. All strains changed their M protein production and/or opacity factor (OF)-activity during the passages. The capacity of each strain to adhere to a pool of buccal cells from six healthy individuals was studied both before and after passage. Five of six strains with decreased OF-activity/M protein production diminished significantly in adherence capacity, whereas one of two strains with increasing OF-activity adhered better to the epithelial cells. The results are discussed in relation to the clinical view of asymptomatic carriers of group A streptococci.

Agar↗

PubMed1986

Synergism between gammaglobulin prophylaxis and penicillin treatment in experimental post-splenectomy sepsis in the rat.

In spite of long-term antibiotic prophylaxis and pneumococcal vaccination, there still exists a proportion of highly susceptible splenectomized or functionally hyposplenic patients at risk of contracting fatal overwhelming infections. We have studied the effect of gammaglobulin prophylaxis in experimental sepsis among splenectomized rats. Administration of 37.5 mg human gammaglobulin/kg body weight 24 h before challenge with 10(3) pneumococci resulted in the survival of 19 of 24 rats, in contrast to 1 of 24 controls. A dose of 19 mg/kg body weight was not protective (7 of 23 survived). However, treatment with penicillin 18 h after challenge in the gammaglobulin-pretreated group of animals saved 21 of 24 animals, although penicillin without gammaglobulin prophylaxis showed no effect. These data indicate that even relatively low circulating concentrations of specific antibody after gammaglobulin prophylaxis might nonetheless be adequate to render septic disease easier to treat.

Animals↗

PubMed1986

Binding of IgM rheumatoid factor to group A, C and G streptococci with IgG Fc receptors.

The possibility that IgM rheumatoid factors bind to streptococci was studied. Using a sequence of Sephadex G200 gel filtration, protein A-Sepharose CL-4B chromatography and preparatory electrophoresis, IgM was isolated from the sera of 2 patients with rheumatoid arthritis and then radiolabelled with 125I. There was significant binding of radiolabelled IgM to group-A streptococci types M1, M15 and M22, and to a group-C and a group-G strain, all expressing IgG Fc receptors, but none to Staphylococcus aureus, Escherichia coli or to 11 other strains of streptococci without IgG Fc receptors. The radiolabelled IgM was separated by affinity chromatography on a column containing human IgG. Types M1 and M15 bound the fraction retained on the column, whereas M22 bound both this fraction and the non-retained fraction. Commercial human IgG, even at high concentrations, did not inhibit binding. The binding reaction, which is perhaps triggered either by the IgM rheumatoid factor or by IgG complexed with rheumatoid factor, could be a useful tool for removal of anti-immunoglobulin from the blood of patients with rheumatoid arthritis.

Arthritis, Rheumatoid↗

PubMed1986

Comparison of antibody levels and protective efficacy against pneumococci in two immunoglobulin preparations for intravenous use.

Passive immunization with modern intravenous immunoglobulin preparations might be used prophylactically in individuals at extreme risk of contracting postsplenectomy sepsis or therapeutically in established infections. Since pneumococci are the predominant causative organisms, we determined antibodies against 14 pneumococcal serotypes in two commercially available immunoglobulin preparations (two batches of each) using enzyme-linked immunosorbent assay. The four batches were remarkably similar in antibody content. Low levels against some clinically important serotypes, i.e. types 3, 8 and 18C were recorded. The protective effect of one batch of each preparation against type 1 pneumococci was documented in splenectomized rats.

Animals↗

PubMed1986

Effect of gamma globulin infusion on type-specific pneumococcal antibody levels in splenectomized adults.

Using an ELISA technique, changes in specific antibody levels against pneumococcal serotypes 1, 4, 7F, 14, 18C and 23F were studied in 8 adults healthy at the time of investigation but splenectomized previously because of hematological disease following infusion of 200 mg/kg body weight of a commercially available immunoglobulin preparation for intravenous use (Sandoglobulin). Among the 4 patients with initially low serum levels of antipneumococcal antibodies, significantly raised antibody levels were demonstrated against type 14 for 8 weeks. On the other hand, the infusion did not lead to increased antibody levels in 3 patients with high preinfusion values for antipneumococcal antibodies. In contrast, a significantly lower antibody value for type 7F was recorded 3 weeks after infusion. Efficacy of immunoglobulin prophylaxis is, therefore, probably doubtful in certain splenectomized patients, and if contemplated should be preceded by analysis of antibody levels against common pathogens.

Adolescent↗

PubMed1986

IgG subclasses and antibodies to group B streptococci, pneumococci, and tetanus toxoid in preterm neonates after intravenous infusion of immunoglobulin to the mothers.

High doses of intravenous immunoglobulin were given to seven pregnant women between the 27th and 36th wk of gestation who were at risk for preterm delivery. Determinations of IgG subclasses and of antibodies against group B streptococcal serotypes, pneumococcal polysaccharides, and tetanus toxoid were done in maternal serum before and after intravenous IgG infusion and after delivery in cord serum. Substantial transplacental passage of the infused material could be observed in five cases where delivery occurred at the 34th wk or later. After the 36th wk of gestation, IgG subclass and antibody concentrations in cord serum were increased up to the levels in the maternal serum.

Antibodies↗

PubMed1986

Effects of sulindac and naproxen in patients with chronic glomerular disease.

Eight patients with chronic glomerulonephritis were treated with either naproxen or sulindac in an open randomized study to observe their effects on the urinary excretion of prostaglandins and renal function. Both drugs were given for 7 days. Naproxen caused a decrease (p less than 0.01) of 80% in prostaglandin PGE2 and decrease (p less than 0.01) of 55% in prostaglandin PGF2 alpha. Sulindac caused a decrease (p = 0.01) of 37% in PGE2 and a decrease (p less than 0.05) in PGF2 alpha of 13%. The decrease in urinary excretion of prostaglandins were greater (p less than 0.05) during the naproxen treatment. Naproxen caused a decrease (p less than 0.05) in 24-hour creatinine clearance of 14 ml/min, an increase (p less than 0.05) in plasma urea of 1.0 mmol/l, an increase (p less than 0.05) in plasma potassium of 0.4 mmol/l and a decrease (p less than 0.01) in 24-hour urinary excretion of albumin of 11 mumol. Sulindac did not change any of these parameters significantly. In conclusion, sulindac affects renal prostaglandin synthesis to a significantly minor degree than naproxen and contrary to naproxen it does not influence the renal function in patients with chronic glomerular disease.

Adult↗

PubMed1986

Interaction between herpes simplex type 1-induced Fc receptor and human and rabbit immunoglobulin G (IgG) domains.

Cells infected with herpes simplex virus type 1 (HSV-1) express a cell surface receptor able to bind to the Fc region of immunoglobulin G (IgG). The ability of HSV-1-infected cells to bind 125I-labelled human and rabbit IgG and IgG fragments was studied to localize the site of interaction to the C gamma 2 or C gamma 3 domains of IgG. 125I-labelled IgG and IgG Fc fragments consisting of C gamma 2 and C gamma 3 domains bound strongly to HSV-infected cells and did not bind to uninfected cells. In contrast, 125I-labelled F(ab')2, Facb [consisting of F(ab')2 and C gamma 2 domains] and pFc' (consisting of C gamma 3 domains) fragments did not bind to any of these cells. Unlabelled IgG and IgG Fc fragments inhibited the interaction between 125I-labelled rabbit IgG Fc and the HSV Fc receptor, whereas F(ab')2, Facb and pFc' fragments failed to inhibit this interaction. These data indicate that the HSV Fc receptor requires both the C gamma 2 and C gamma 3 domains for interaction with the IgG molecule analogous to the known interaction of protein A of Staphylococcus aureus, the Fc binding proteins of Group A, C and G streptococci, and certain human rheumatoid factors.

Animals↗

PubMed1986

Placental gas exchange in the guinea-pig: fetal blood gas tensions following the reduction of maternal oxygen capacity with carbon monoxide.

The effect of CO hypoxia on the placental exchange of respiratory gases was studied in anaesthetized pregnant guinea-pigs near term. Fetal PO2 and PCO2 were measured by mass spectrometry from a blood gas catheter in the right atrium. Administration of 5 ml CO over 65 s reduced maternal oxygen capacity by 26%. There was a rapid fall in fetal arterial PO2 and a more gradual rise in fetal PCO2. It was shown in separate experiments that the carboxyhaemoglobin content of fetal blood did not alter greatly in the first few min. after CO administration, which is the interval within which fetal PO2 was seen to fall. The alteration in fetal gas tensions can therefore be ascribed to the increased oxygen affinity and reduced oxygen capacity occasioned by the presence of carboxyhaemoglobin in the maternal blood. The alteration in placental oxygen transfer was calculated from the experimental findings, using a mathematical model of placental gas exchange in the guinea-pig. The total reduction in the oxygen transfer was 32% of the initial value. It was calculated that the reduction in maternal oxygen capacity was responsible for about two-thirds of this decrease, the remainder being due to the increased oxygen affinity of maternal blood.

Acid-Base Equilibrium↗

PubMed1986

Interaction between streptococcal IgG Fc receptors and human and rabbit IgG domains.

Groups A, C and G streptococci were tested for their ability to bind 125I-labelled fragments of human and rabbit IgG in order to localize their sites of interaction with IgG domains. Among the Group A streptococci, strains with IgG Fc receptors bound 85% of the added IgG Fc fragments in the test systems, whereas these strains showed practically no reactivity with F(ab')2, Facb (F(ab')2 + C gamma 2 domains) or pFc' (C gamma 3 domains). The Group C and Group G strains bound 48-100% of IgG Fc, but could also bind up to 36% of the added F(ab')2 in accordance with a previously described 'alternative' Fab reactivity. However, unlabelled IgG F(ab')2 or Facb showed no, or only slight, inhibitory capacity for the binding of 125I-labelled IgG Fc to the C and G strains. Collectively, these results indicate that Groups A, C and G streptococci require both the C gamma 2 and C gamma 3 domains for interaction with IgG, and most probably also bind in the interface region between the C gamma 2 and C gamma 3 domains as has been shown for staphylococcal protein A.

Animals↗

PubMed1986

Conservative or surgical treatment of acromioclavicular dislocation. A prospective, controlled, randomized study.

In a prospective, controlled, randomized study of acute acromioclavicular dislocations, we compared conservative and operative treatment (the Phemister procedure) with regard to the clinical results, complications, and social costs. Forty-one patients were operated on and forty-three patients were treated conservatively. Two patients who were operated on and three who were treated conservatively had to have the lateral extremity of the clavicle resected because of pain. The rehabilitation period was significantly shorter with non-operative treatment, and after thirteen months there was no difference in the clinical results. There were no serious postoperative complications, but about half of the patients who were operated on had problems with the metallic device, such as breakage or migration of the pins, or both, and six patients had a superficial infection. For most patients with total acromioclavicular dislocation we recommend conservative treatment with a sling until the patient is free of pain. Operation should be considered in thin patients who have a prominent lateral end of the clavicle, in those who do heavy work, and in patients whose daily work requires that the shoulder often be held in about 90 degrees of abduction and flexion.

Acromioclavicular Joint↗