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Biomedical subjects

J Eklund

Publications and source records attributed to J Eklund.

At least 37 records · Page 2Linked to original sources
PubMed1988

Impressions for prosthodontic restorations reproducing narrow spaces and severe undercuts.

Distortion of an impression material may occur in special clinical situations in which the material's elastic limit is exceeded. Impressions were made of a master model designed to test such situations. Three different hydrocolloids and an addition silicone were used in the experiment. An extended setting time had to be used for one material, to prevent it from tearing. When this extended time was used, this material was the dimensionally most accurate material in the test. All materials were accurate in reproducing normally positioned abutments, while some of the impressions failed to reproduce adjacent abutments with particularly narrow interspaces; narrow passages may therefore require further tooth preparation. In the most severely undercut area differences existed among the materials, and sometimes tears occurred. When the papilla is missing, the undercut area should be blocked out to prevent plastic deformation of the impression material, causing inaccurate restorations.

Agar↗
PubMed1986

Perinatal mortality from Rh(D) hemolytic disease in Finland, 1975-1984.

Analysis of 41 deaths from Rh(D) hemolytic disease (HDN) in Finland in the past 10 years revealed that 17 occurred in mothers immunized before anti-D IgG was available and three in mothers immunized by blood transfusion in earlier years. Nine deaths were related to loopholes in the anti-D program and could presumably have been prevented by ensuring that all eligible Rh-negative women received anti-D IgG after delivery and abortion. Six deaths were due to immunization during a first pregnancy after the 28th week and three to maternal immunization despite anti-D IgG. Immunization from these sources can only be reduced by anti-D IgG injected antenatally as well as postnatally, though the complete eradication of HDN seems to be beyond our grasp. Giving anti-D IgG to Rh-negative women after the birth of a Rh-positive infant or after an abortion has been common practice in Finland, the former since 1969 and the latter since 1971. Although anti-D prophylaxis has been very effective in reducing the incidence of Rh(D) hemolytic disease, new cases continue to occur. Since the prophylaxis fails to prevent perinatal mortality, we decided to discover how the mothers whose infants died from HDN had become immunized in the past 10 years.

Blood Transfusion↗
PubMed1985

Phosphate supplementation in parenteral nutrition.

Pronounced serum phosphate deficiency has been shown to be deleterious when starting parenteral nutrition in severely malnourished patients. The consequences of phosphate deficiency and the need for phosphate supplementation in critically ill patients are not well known. Thirty ICU patients randomized into two groups were studied. The patients received complete parenteral nutrition with and without addition of extra phosphate. The low phosphate group got 7.5 mmol phosphate (from the phospholipids in the fat emulsion) and the high phosphate group got 60-80 mmol phosphate/day. There were no significant differences in serum phosphate or calcium levels between the groups. In the high phosphate group the phosphate balance was positive and calcium balance zero while in the low phosphate group both phosphate and calcium balances were negative. The phosphate content in a standard nutrition programme is not sufficient to create a positive phosphate balance. With the addition of 80 mmol phosphate/day a positive balance was achieved. It is hard to establish guidelines for the administration of phosphate in ICU patients. 20-40 mmol may normally be satisfactory but we have shown that ICU patients may need and can tolerate up to 80 mmol/day.

Adult↗
PubMed1985

Quantitation of immunoglobulin classes and subclasses in anti-Rh (D) antibodies.

The isotype profiles of anti-Rh (D) antibodies were measured from 16 serum samples with a solid-phase radioimmunoassay that employed monoclonal anti-isotype antibodies. These antibodies had been standardized in another solid-phase system with the aid of monoisotypic antibodies (e.g., anti-tetanus toxoid of isotype IgG4), and this permitted calculations of the relative concentrations of different isotypes in each anti-D population. Of the heavy-chain isotypes, only IgG1 and IgG3 were found in anti-Rh (D) antibodies. The share of IgG1 varied from 100% (2 sera) to 0% (1 serum) of detected units, and the mean proportion was 73.8%. The remainder was IgG3 (mean share 26.2%). The proportions of kappa and lambda immunoglobulins varied greatly in individual sera, in three sera only kappa Ig and in one serum only lambda Ig could be detected.

Humans↗
PubMed1985

Intensive plasma exchange as an adjunct to management of severe rhesus disease.

Large-volume plasma exchange was used to reduce the maternal anti-D concentration in a case of severe rhesus disease. The treatment commenced at 19 weeks' gestation and continued until the infant was successfully delivered at 35.2 weeks' gestation. The initial anti-D level of 30 IU/ml was lowered to 10 and was maintained below that level, with few exceptions throughout the program. The volume of plasma exchanged each week varied between 6.8 and 13.4 liters, a total of 154 l. Three IUTs were accomplished, starting from 31 weeks' gestation. The patient's OD values remained far below those recorded in her previous pregnancy which terminated in neonatal death. The replacement fluids consisted of 98 l PPS with FFP added to equilibrate the patient at the end of each procedure, altogether 33 l. At 33 weeks' gestation she developed a transient non-A, non-B hepatitis probably caused by the use of FFP. However, she later made a complete recovery. Large-volume plasma exchanges commenced early in high-risk pregnancy must be individually designed and based on the kinetics of anti-D production. The replacement fluids should preferably consist of pasteurized albumin solutions and intravenous immune globulin.

Adult↗
PubMed1985

Blood coagulation and fibrinolytic factors as well as their inhibitors in trauma.

Tests generally accepted in the diagnosis of DIC were evaluated in 13 patients with multiple trauma. The blood samples were drawn on admission before treatment with blood, blood products or heparin. The tests included platelet count, prothrombin complex (Normotest/Thrombotest), Factor V, Factor VIII:C, fibrinogen, fibrinogen degradation products (FDP), thrombin and Reptilase times as well as the ethanol gelation test (fibrin monomer). Based on the results of the tests, the patients were categorized into DIC, suspected DIC and no DIC groups. It was found that those patients who were referred to the DIC group were also those who later developed the most severe organ dysfunction and who stayed the longest time in the Intensive Care Unit. Thus, the clinical and laboratory findings agreed. The Normotest/Thrombotest ratio, thrombin times and Reptilase times, and presence of fibrin monomers were of limited value for the diagnosis of DIC. To make a correct diagnosis, the results of several of the conventional tests had to be combined. Additional tests were then evaluated. An increase of the fibrinopeptide A (FPA) level and the Factor VIIIR:Ag (vWF:Ag)/Factor VIII:C ratio in all the DIC patients as well as a decrease of the antithrombin (AT) level in some DIC patients indicated thrombin activity and a risk of thromboembolic events. A decrease of plasminogen and alpha 2-antiplasmin indicated activation of the fibrinolytic system. It is concluded that these new tests are useful in the diagnosis and treatment of DIC and similar proteolytic states.

Adolescent↗
PubMed1984

Blood coagulation and fibrinolytic factors and their inhibitors in critically ill patients.

In a search for new variables, for the diagnosis of disseminated intravascular coagulation (DIC) and for guidelines of therapy in such conditions, 22 severely ill patients were studied. The diagnosis of DIC was based on determinations of platelet counts, prothrombin complex (Normotest), antithrombin (AT), fibrinogen degradation products and fibrinogen. Nine patients were diagnosed as having DIC, eight patients were referred to a suspected DIC group and five to a group of no DIC. The laboratory findings were found to agree with the clinical status. In addition several new parameters were investigated: factor XII, prekallikrein, Simplastin A--another prothrombin complex factor method, factor X, plasminogen (PLG), antiplasmin (AP) and kallikrein inhibitors (KI). Platelet counts, prothrombin complex and antithrombin were mostly pathological in DIC-patients. Of the alternative tests prothrombin complex, fibrinopeptide A and the kallikrein inhibitor as well as the two tests for fibrinolysis (PLG and AP) were significantly altered in DIC-patients. The inhibitor capacity (AT, APV and KI) was lower in patients who died than in survivors and decreased still further in those of the non-survivors who had DIC. Thus the inhibitors can be used as predictors of outcome and hopefully for guiding therapy. To establish the diagnosis of DIC we suggest measurement of platelet count, prothrombin complex, plasminogen as well as of the inhibitors.

Adolescent↗
PubMed1984

A historical review of hydrocolloids and an investigation of the dimensional accuracy of the new alginates for crown and bridge impressions when using stock trays.

Reversible hydrocolloids have been used since 1937 and irreversible hydrocolloids since 1947 for the making of impressions for fixed prostheses; the impression techniques were similar to today's. The dimensional accuracy of reproduction of the irreversible hydrocolloids has been proved since 1947. In this paper the dimensional accuracy of three new alginates, Algi -X ( Algiflex Super, Howmedica Alginate), Ardent Alginate, Ultrafine and a combination material, Colloid 80/ Algiace ( Dentloid / Algiace ) were compared to two agar hydrocolloids and an addition silicone, when different stock trays were used as in the dental clinic. In most clinical situations the new alginates used in metal stock trays are as accurate as the "old" impression materials. The combination material is less accurate when many abutment preparations are to be reproduced. Whether perforated or nonperforated metal stock trays are used with the alginates is of no consequence to the accuracy. Alginates used in disposable plastic trays may cause severe inaccuracy. In narrow spaces with severe unblocked undercuts some of the alginates may be inferior to the other impression materials in this study.

Agar↗
PubMed1983

Severe acquired antithrombin III deficiency in relation to hepatic and renal insufficiency and intrauterine fetal death in late pregnancy.

Acute fatty liver (AFLP) is a rare complication of late pregnancy. The maternal and fetal mortality has earlier been reported to be about 75%, but during the last decade a reduced mortality to about 30 and 50%, respectively, has been reported in the literature. Disseminated intravascular coagulation (DIC) has been suggested as a contributing cause to the high mortality. The treatment of DIC has long been under debate, and recently the administration of antithrombin III (AT) concentrate in addition to other supportive treatment has been reported successful. This paper presents the survival of 1 patient with severe liver and renal failure indicating AFLP complicated by severe disturbances in blood coagulation and fibrinolysis. The patient was treated with AT concentrate and small doses of heparin, blood coagulation factors, large amounts of glucose intravenously and supportive intensive care. The pregnancy was terminated by cesarean section. The child was stillborn and 75% of the placental parenchyma was fibrosed.

Acute Kidney Injury↗
PubMed1982

Turnover rate of anti-D IgG injected during pregnancy.

Anti-D IgG was injected into 15 Rh-negative women in the 28th week of gestation and into three non-pregnant women. The uptake of anti-D after the intramuscular injections was calculated by measuring the concentration of antibody in the plasma with an autoanalyser. The biological half life and the catabolic rate of anti-D IgG were calculated according to a compartmental model. The recovery in vivo of anti-D was an average 24% in the non-pregnant women and 21% in the pregnant women. The half life of anti-D were 24 and 21 days, respectively. With a dose of 125 micrograms the plasma anti-D concentration was less than 1 ng/ml at about 10 weeks after the injection. With double the dose the concentration at delivery was at least 1 ng/ml. Although 250 micrograms of anti-D IgG seems to be effective when given in the 28th weeks of gestation, the great individual variations in uptake and recovery rates will lead to occasional cases of Rh-immunisation during pregnancy despite all routine regimens.

Antibodies, Anti-Idiotypic↗
PubMed1981

Characterization of a spontaneous disease of white leghorn chickens resembling progressive systemic sclerosis (scleroderma).

University of California, Davis (UCD) line 200 White Leghorn Chickens spontaneously develop a syndrome that has many analogous features to human progressive systemic sclerosis. This syndrome is characterized by progressive involution of comb, dermal fibrosis, and distal polyarthritis. These three features occur within 6 wk after hatching, and are accompanied by a 40% mortality as a result of vaso-occlusive disease, with development of secondary infection of peripheral gangrenous lesions. Birds that survive greater than 2 mo after hatching progressively develop fibrosis of the esophagous and mononuclear infiltration of heart and kidney, with prominent occlusion of small and medium sized blood vessels. In addition, line 200 chickens develop rheumatoid factors, antinuclear antibodies, and antibodies to collagen, but do not have antibodies to thymocytes, DNA, or extractable nuclear antigens. Moreover, antinuclear antibodies when studied using HEp-2 cells as substrate demonstrate predominantly a speckled pattern. This syndrome of line 200 chickens is not detectable in F1 crosses to several UCD inbred lines. F1 X parental line BC1 backcrosses have an approximately 50% incidence of disease, suggesting that this syndrome is inherited as autosomal recessive. However, only 4% of F2 generation birds show abnormal symptoms, suggesting the presence of modifying genes. There is no appearance of IgG deposition, as determined by immunofluorescence, in either skin, blood vessels, esophagus, or heart. However, approximately 20% of chickens have a glomerulonephritis; this feature appears to be a terminal event and does not appear clinically significant. Although this syndrome of line 200 chickens has several features that are in sharp distinction to human scleroderma, the presence of common immunologic and pathologic denominators suggest that this spontaneous disease may be an appropriate model to develop a better understanding of autoimmune connective tissue diseases.

Age Factors↗