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Biomedical subjects

R Böhm

Publications and source records attributed to R Böhm.

At least 73 records · Page 4Linked to original sources
PubMed1990

[Detection specificity of an optimal solid-phase enzyme immunoassay for Pseudomonas aeruginosa and Pseudomonas mallei].

The evaluation and application of an enzyme-immunoassay (EIA) for the detection of Pseudomonas (Ps.) aeruginosa and Ps. mallei is described. Polystyrene beads (1/4'') as the solid-phase are prepared by coating the balls with purified IgG from the serum of rabbits (9-12 micrograms/bead) in Coating-Buffer pH 9.6. After washing the balls they are saturated with 10% BSA or 10% FCS in PBS-Tween 20. The bacteria bound to the coated balls are detected by the specific peroxidase labelled IgG. This EIA using Ps. aeruginosa (P9) as a model is able to detect this bacterium within 5 hours, with stored coated balls 3.5 hours, with a detection limit of 10(4) CFU. Nine Pseudomonas-strains react stronger than other strains. These cross-reactions can be substantially reduced by absorbing the P9-conjugate with the cells of Ps. stutzeri (P15). With the other Pseudomonas-strains a high specificity is found with the P9-conjugate. After modifying this EIA for the detection of Ps. mallei (P18) the strains Ps. mallei (P57), Ps. pseudomallei (P17) and Ps. cepacia (P67) react with the P18-conjugate. With the other tested strains a high specificity is found at 10(7) CFU. The polystyrene bead-EIA is recommended as a sensitive and specific test for the detection of Ps. aeruginosa in about 5 resp. 3.5 hours. It only requires normal laboratory equipment and is thus a highly practicable method for routine diagnostic of Ps. aeruginosa.

Cross Reactions↗
PubMed1989

Pharmacokinetics of nitrendipine in terminal renal failure.

The pharmacokinetics and plasma protein binding of nitrendipine in patients with terminal renal failure have been compared with those in subjects with normal renal function. Kinetic parameters were calculated after a single 40 mg oral dose, an i.v. injection of 3 mg and after a 15 mg i.v. infusion of nitrendipine. Steady-state plasma levels were determined after 5 days of oral treatment with 20 mg b.d. Pharmacokinetic parameters and steady-state plasma levels in patients with renal failure did not differ from those in subjects with normal renal function. Nitrendipine was as highly bound to plasma proteins in patients with renal failure, as in subjects with normal renal function. The plasma protein did not differ between the two. The dosage of nitrendipine need not be modified for kinetic reasons in patients with renal failure.

Administration, Oral↗
PubMed1989

Total and free steady-state plasma levels and pharmacokinetics of nifedipine in patients with terminal renal failure.

The total and free steady-state plasma levels of nifedipine in patients with renal failure have been compared with those in subjects with normal renal function. Studies were done after administration of nifedipine 10 mg t.d.s. p.o. for 5 days, after i.v. infusion of 4.4 mg, and after a single 10 mg oral dose. The systemic clearance of nifedipine after a single i.v.-dose was higher in subjects with renal insufficiency (854 ml/min) than in those with normal renal function (468 ml/min). After the single oral dose the AUC (6100 ng.min.ml-1) and maximum plasma concentration (75.0 ng.ml-1) were lower than in subjects with normal renal function (19300 ng.ml-1; 122 ng.ml-1). The plasma protein binding of nifedipine averaged 95.5% in normal subjects and 94.8% in patients with renal failure. Although free and total steady-state plasma levels of nifedipine tended to be somewhat lower than normal in renal failure, the changes in pharmacokinetics and decreased protein binding of nifedipine did not result in a significantly different steady-state plasma level of the drug. The blood pressure response to a given plasma nifedipine level appeared to be enhanced in renal failure.

Administration, Oral↗
PubMed1989

The safety of blood component preparation with blood cell separators.

Despite initial skepticism following the introduction of cytapheresis with blood cell separators, this technology is now accepted in the field of blood donation. Serious, life-threatening reactions have not been observed and thus could not influence the development, and minor problems can be reduced further on the basis of recommended safety guidelines. Additionally, the continuous registration of side effects is helpful for a complete elimination of undesired reactions.

Blood Cells↗
PubMed1989

[Comparison of the sporocidal effects of two different disinfectants i a model experiment with pathogenic and nonpathogenic clostridial spore as well as with Bacillus cereus].

Official methods concerning the examination of sporocidal effects of disinfectants are presently lacking in the Federal Republic of Germany. Spore resistance of selected clostridial species towards formaldehyde and peracetic acid was examined by suspension tests and germ-carrier tests in comparison to spores of Bacillus cereus. Formaldehyde in concentrations between 5% and 20% as well as peracetic acid in concentrations between .004% and .125% were tested. Spore concentration of 10(6) spores/ml in the suspension-tests and 10(4) spores/ml in the germ-carrier tests with wooden germ-carriers were used. Against formaldehyde spores of Cl. septicum had the lowest resistance in the suspension tests followed by Cl. difficile, Cl. tertium, Cl. bifermentans and Cl. perfringens. Cl. sporogenes strain NCTC 532 had the most resistant spores. Concerning peracetic acid the situation was nearly the same. The resistance of all spores of pathogenic species under investigation towards chemical disinfectants was covered by those of Cl. sporogenes NCTC 532 treated with isopropanol. Isopropanol treated spores of B. cereus offer an alternative solution for practical disinfectant testing because spore production as well as growth of clostridia entail great expense. In order to cover the resistance of spores of Cl. perfringens A, the most resistant pathogenic clostridial species tested here, increased spore concentrations of B. cereus would be necessary.

Bacillus cereus↗
PubMed1989

[The detection of Bacillus anthracis protective antigens by enzyme immunoassay (EIA) using polyclonal and monoclonal antibodies].

An Enzyme-Immunoassay (EIA) for the detection of Bacillus anthracis-protective antigen (PA) within one hour was developed. If the rabbit antiserum was used, 15 ng PA/ml could be detected and with the monoclonal antibody, the detection limit was 60 ng PA/ml. With respect to the higher specificity and with regard to the aspects of animalcare, monoclonal antibodies should be used in the test instead of the polyclonal antiserum.

Animals↗
PubMed1988

[Advice as to the safety precautions for handling infectious material in a veterinary practice laboratory].

The number of microbiological investigations with infectious material increases in veterinary practice. Frequently the working space is cramped so that special security measures are imperative. These measures are discussed in detail. Their disregard can result in laboratory infections with zoonotic agents and in unpleasant lawsuits with bad consequences. The German regulations pertaining to security in laboratories are listed. They should be observed in any case.

Animals↗
PubMed1987

The influence of antituberculosis drugs on the plasma level of verapamil.

The influence of antituberculosis drugs on the plasma level of verapamil was studied after its oral and intravenous administration. Six patients who had been treated for at least 6 months with a combination of rifampicin, ethambutol and isoniazid received a single oral dose of 40 mg verapamil. As compared to untreated subjects, the antituberculosis drugs greatly reduced the bioavailability of the calcium antagonist. Studies in patients in whom treatment with ethambutol and isoniazid had been discontinued revealed that the effect was due to rifampicin. The drugs for tuberculosis had no influence on the plasma level of verapamil when it was given intravenously. The findings can be explained by the induction of verapamil metabolizing liver enzymes in patients treated with rifampicin.

Administration, Oral↗
PubMed1987

The effects of verapamil and propranolol on exercise tolerance in hypertensive patients.

In a single-blind, placebo-controlled crossover study the effects of verapamil (450 +/- 30 mg/day) and propranolol (160 +/- 20 mg/day) on endurance time during submaximal exercise were compared in eight patients with essential hypertension. The drugs were given in randomized order. Each active drug period was preceded by a placebo phase. Endurance tests were performed during both placebo periods and treatment with verapamil and propranolol by bicycle ergometry. Both drugs were equally effective in decreasing resting blood pressure. Verapamil and propranolol reduced exercise heart rate, the effect of propranolol being more pronounced. With placebo, endurance time during exercise was 57 +/- 11 minutes; with propranolol it was 32 +/- 7 minutes (P less than 0.05). Verapamil had no influence on endurance time. The study demonstrates that in contrast to propranolol, verapamil has no influence on exercise tolerance during submaximal work in patients with hypertension.

Adult↗
PubMed1987

[Aerosol disinfection of bacterial spores].

The present investigations are divided into two parts. First it is tested which commercial disinfectants are efficient in aerosol disinfection of bacterial spores. This part is carried out in an aerosol chamber with airborne spores (laboratory experiments). The best results are obtained with peracetic acid, hydrogen peroxide and formaldehyde are effective with some restrictions. With these disinfectants it is tested in the second part if the aerosol disinfecting-method is capable for disinfecting rooms with electronic equipment. This part is carried out in a vessel under open air conditions (field experiments). Bacterial spores dried on germ carriers of limewood, aluminium and rusty iron are exposed to disinfectant aerosols under those temperature and relative humidity conditions which are representative for the four seasons in Germany. In these investigations there are also included germ carriers with spores, that have been lyophilized without any protective substances respectively with Bentonite, Mixtura desiccans and Silicagel + Serum as protective substances. To check the corrosive effect of disinfectant aerosols electronic pocket calculators and pocket transistor receivers have been exposed to the aerosols. The best results are obtained with formaldehyde at temperatures above 10 degrees C and relative humidities within 65% to 95%. At temperatures and relative humidity conditions outside of this optimal range the effectiveness of formaldehyde tends to zero. Hydrogen peroxide is capable for disinfecting spores on germ carriers of limewood and aluminium at all temperature and relative humidity conditions; on germ carriers of rusty iron the effectiveness is reduced strongly. Same results could be obtained with peracetic acid respectively a mixture of peracetic acid and hydrogen peroxide. With these disinfectants a decontamination of rusty iron surfaces is impossible too except the germ concentration on the surface is below 10(4) CFU/cm2. As to the protective substances used in the lyophilization process Bentonite and Mixtura desiccans cause hardly any change in the disinfectant resistance of bacterial spores. Silicagel + Serum in comparison to that protects the imbedded spores that far, that no disinfection of these germ carriers was achieved with the oxidizing agents. As about 15 disinfection runs with each disinfectant did not cause permanent damages to the pocket calculators and transistor receivers it can be emphasized as result of these investigations that aerosol disinfection is an effective method in disinfecting rooms with electronic equipment under middle European climate conditions.(ABSTRACT TRUNCATED AT 400 WORDS)

Aerosols↗
PubMed1987

[The safety of apparative cytapheresis].

In a retrospective analysis 1568 platelet apheresis procedures and 652 leukocytophereses performed from April 1976 to June 1986 were examined. 886 procedures were performed using the Fenwal CS 3000, 777 with the IBM 2997, and 293 with the Haemonetics V50, whereas in 264 procedures the Model 30 was used. The study aims to answer 3 donor-related questions: To what extent are the blood cells changed by the donation? How does the donor respond to the technical requirements of the donation, such as length of the procedure, blood volume processed, amount of concentrate removed during the donation? How often did side-effects or undesired reactions occur? We found that thrombocytapheresis led to a decrease in platelets in the peripheral blood of between 20% (CS3000) and 33.7% (IBM), and an increase in leukocytes of between 4.24% (IBM) and 17.8% (Model 30), whereas erythrocytes, hemoglobin and hematocrit showed a similar decrease within a range of between 1.1% and 2.67% in all systems. Following leukocytapheresis the leukocyte counts of the peripheral blood were decreased by up to 12%, erythrocyte counts by up to 5% and platelets between 15% (IBM) and 29% (Model 30). The list of irregularities included technical problems and donor reactions (e.g., citrate reactions, reactions of blood circulation, and blood flow in the donor). There were no serious side-effects. Early terminations of 42 (= 1.9%) donations were for prophylactic reasons exclusively. Few moderate undesired reactions occurred (4 = 0.2%), but none of the donors contributing to the more than 2,000 donations were ever hospitalized, demonstrating the safety of cytapheresis with all separators.

Blood Cell Count↗