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Biomedical subjects

R Engler

Publications and source records attributed to R Engler.

At least 91 records · Page 5Linked to original sources
PubMed1977

[Immunochemical determination of human hemoglobin in biological fluids (author's transl)].

An assay of human hemoglobin by immunonephelometry-electroimmunodiffusion is proposed. Concentrations in the range from 5 to 180 mg% can be determined to within 2--5% accuracy. The immunonephelometric assay is independent of the presence of haptoglobin whereas the electroimmunodiffusion assay is not. This immunochemical assay, independent of the peroxydase activity of hemoglobin, can be carried out in any biological fluid (plasma, urine, gastric fluid).

Evaluation Studies as Topic↗
PubMed1977

Pharmacologic and hemodynamic influences on the rate of isovolumic left ventricular relaxation in the normal conscious dog.

We studied the effects of acute pharmacologic and hemodynamic interventions on isovolumic left ventricular relaxation in 19 conscious dogs using micromanometer tip catheters. Isoproterenol (11 studies) augmented peak rate of rise of left ventricular pressure [(+) dP/dt] by 1,275+/-227 (SE) mm Hg/s (P < 0.001) and dP/dt at an isopressure point of 35 mm Hg during isovolumic relaxation [(-) dP/dt(35)] by 435+/-80 mm Hg/s (P < 0.001). Peak (-) dP/dt decreased by 467+/-89 mm Hg/s (P < 0.002). The time constant, T, derived from the logarithmic fall of pressure during isovolumic relaxation, shortened from 20+/-2.8 to 14.9+/-1.8 ms (P < 0.003). Calcium (11 studies) increased peak (+) dP/dt and (-) dP/dt(35) (both P < 0.0001); peak (-) dP/dt was unchanged. T shortened from 20.4+/-1.8 to 17.3+/-1.5 ms (P < 0.002). Volume (13 studies) did not affect either dP/dt or T. Phenylephrine (13 studies) augmented peak (-) dP/dt, but reduced (-) dP/dt(35) (both P < 0.01); T lengthened from 22.1+/-1.5 to 32.5+/-1.5 ms (P < 0.01). In 15 studies, rapid atrial pacing increased peak (+) dP/dt and (-) dP/dt(35) (both P < 0.01). In the first post-pacing beat, peak (-) dP/dt and (-) dP/dt(35) decreased (both P < 0.01), although peak (+) dP/dt increased further. T paralleled values of (-) dP/dt(35). In five dogs, beta adrenergic blockade had no significant effect on any variable after calcium, volume, or phenylephrine infusion or during or after atrial pacing when the pre-and post-propranolol states were compared. We conclude that positive inotropic interventions augment both left ventricular contraction and relaxation. The changes in isovolumic relaxation are independent of alterations in sympathetic tone produced by beta-adrenergic blockade. Peak (-) dP/dt may not be a valid measure of left ventricular relaxation rate during acute alterations in inotropic state or afterload.

Animals↗
PubMed1977

Immunochemical study on serum proteins in systemic sclerosis.

Forty one patients with systemic sclerosis were studied after separation into three groups according to Barnett's classification. A multi-dimensional statistical analysis eight serum proteins revealed a difference between control patients and patients with type I and type II scleroderma. Type I scleroderma was characterised by a rise in alpha 2 macroglobulin and in the C4 fraction of complement, whilst in type II scleroderma all the proteins studied were raised, with the exception of CO complement, which was normal, and transferrin which was markedly decreased.

Blood Proteins↗
PubMed1976

Entomopathogens: ecological manipulation of natural associations.

The control of insect pests with entomopathogens is unique, in that naturally occurring host-pathogen relations are manipulated to the benefit of man: protecting agricultural crops and forests or controlling insect vectors of disease. The isolation and identification of a virulent pathogen is the initial step in the development of a potential control agent. Production of the pathogen in adequate quantities must be possible either in vivo (insects) or in vitro (artificial medium). To insure usefulness, the pathogen must remain viable in the formulated form and after application in the field. Since inactivation rather than persistence is a problem, the pathogens must be formulated, protected, and applied to insure satisfactory pest control action. Studying the natural host--pathogen interactions will be necessary in order to manipulate the pathogen effectively, by introducing it at the most opportune time in the life cycle of the target pest. Generally, insect pathogens are more selective than conventional pesticides; this will limit their use and industrial development. Development, at least in part, by the public sector may be necessary and desirable. The most promising areas for the use of pathogens are in integrated pest management and in situations where pests have developed resistance to chemical control.

Animals↗
PubMed1976

[Preparation and immunoephelometric quantitation of fibrinogen in rabbits].

Pure rabbit fibrinogen was prepared by a method involving two ammonium sulfate precipitations, one 2 M phosphate buffer precipitation, one DEAE cellulose chromatography and lastly one Sepharose 6 B chromatography. The aminoacid composition was determined and an immunonephelemetric assay was proposed. This assay followed an accurate determination of fibrinogen concentration in a rabbit with inflammatory reaction.

Amino Acids↗
PubMed1976

[Usual values of haptoglobin, protein-bound sialic acid and blood sedimentation in a population of the Cherbourg region].

The authors studied 3 parameters commonly used for the exploration of an inflammatory syndrome (determination of globular sedimentation rate at the first and second hour, concentration of plasma haptoglobin, sialic acid bound to plasma proteins rate). Haptoglobin and acid sialic assays were solely used in determining a control population (816 patients without any inflammatory reaction). As a matter of fact, the values we found complied with a normal distribution rule and confidence limits with a probability of 95% were obtained.

Blood Sedimentation↗
PubMed1975

[An immunonephelometric determination of rabbit haptoglobin].

An immunonephelemetric determination of rabbit haptoglobin was carried out. At first, pure haptoglobin was isolated and then monospecific immunserums were obtained from rats. This method completes the regular determination of haptoglobin in all cases where the peroxydasic activity of the haptoglobin-hemoglobin complex is inhibited either by an hemolytic process, as is the case for rabbits, or by some inhibitors of the peroxydasic reaction.

Animals↗
PubMed1975

Biochemical criteria for the evaluation of drug efficiency on adjuvant arthritis and nephrotoxic serum nephritis in the rat: studies with phenylbutazone, L-Asparaginase, colchicine, lysine acetylsalicylate, and pyridinol carbamate.

The levels of serum orosomucoid, haptoglobin, and seromucoid were evaluated as possible quantitative criteria for the estimation of drug efficiency in adjuvant arthritis and nephrotoxic serum nephritis. In adjuvant arthritis, haptoglobin, seromucoid, and chiefly orosomucoid serum levels were generally very sensitive to anti-inflammatory agents such as phenylbutazone and pyridinol carbamate, and to immunosuppressive agents such as L-asparaginase. There was a significant correlation between the serum levels of these glycoproteins and the arthritis scores. In nephrotoxic serum nephritis, seromucoid levels were correlated with the proteinuria of the autologous phase and were found to be a good complementary criterion for the analysis of the efficiency of pyridinol carbamate, colchicine, iysine acetylsalicylate, and L-asparaginase.

Animals↗
PubMed1975

[Haptoglobin assay using the LKB 8600 reaction rate analyzer].

The reaction rate analyzer LKB 8 600 is used in a new haptoglobin evaluation method. This technique involves formation of peroxidatic complex between haptoglobin and horse or human hemoglobin (human hemoglobin is easier to prepare), then oxidation of gaiacol with registering of optical density rise. Results fit completely with those of the classical Technicon autoanalyzer technique. The method is accurate, fast, easy to perform, and appliable to large series, while necessitating only 10 mul of serum.

Animals↗
PubMed1971

Effect of the purification of virus antigens on the production of specific complement-fixing antibodies.

The effect of viral purification procedures on the antibody response of guinea pigs to immunization with reovirus type 2 and echovirus type 19 was investigated. Three grades of antigens were employed: (i) infectious monkey kidney tissue culture fluid (TCF), (ii) virus sedimented in the ultracentrifuge and suspended in phosphate-buffered saline, and (iii) virus purified by centrifugation in CsCl density gradients. The antibody response of the guinea pigs was studied by the hemagglutination inhibition, complement fixation, and serum neutralization tests. Only sera produced from virus purified by CsCl density gradients reacted specifically with homologous antigen in the complement fixation test. Sera from animals receiving tissue culture fluid virus or sedimented virus cross-reacted with heterologous antigens such as tissue culture fluid from uninfected monkey kidney cells. All sera, however, reacted specifically in hemagglutination inhibition and serum neutralization tests. Sera from intranasally infected animals (reovirus type 2), even though reacting specifically in the complement fixation test, had much lower titers than sera from animals inoculated intramuscularly.

Animals↗