PubMed Health⌕ Search

Biomedical subjects

D Neumeier

Publications and source records attributed to D Neumeier.

At least 55 records · Page 3Linked to original sources
PubMed1989

Immunocytochemical localization of the sex hormone-binding globulin in a human hepatoma cell line.

The human hepatoma cell line HEP G2 was investigated in an indirect immunofluorescence study for localization of the sex hormone-binding globulin. Cells were grown directly to confluency on the slides used for the immunocytochemical staining. A fine granular cytoplasmatic fluorescence pattern revealed the presence of sex hormone-binding globulin. Chang-liver cells used as controls, incubated under the same conditions, did not fluoresce. The synthesis of the hormone-binding protein in HEP G2 cells, which could be stimulated by L-thyroxine in the culture medium, was monitored by either indirect immunofluorescence or by immunoradiometric determination of sex hormone-binding globulin in the supernatant. These studies demonstrate that immunofluorescence techniques are able to detect sex hormone-binding globulin in human hepatoma cells.

Carcinoma, Hepatocellular↗
PubMed1988

Evaluation of a new chemiluminescence immunoassay for the determination of human chorionic gonadotropin in serum.

A new commercially available chemiluminescence immunoassay for the quantitative measurement of human chorionic gonadotropin and its beta-subunit in serum was compared with the enzyme immunoassay used in our routine laboratory. Human chorionic gonadotropin was determined in serum from pregnant women, as well as from women with abortus imminens, suspected ectopic pregnancies or with molar pregnancies. The new human chorionic gonadotropin assay was also evaluated in combination with an automatic sample processor for distributing samples to the antibody-coated wells of the microtitre plates. The analytical precision, specificity and accuracy of the human chorionic gonadotropin assay were assessed with 152 sera, using the 60 min-incubation as well as the shorter 15 min version. Specificity was comparable with the conventional system, whereas the chemiluminescence assay performed better with respect to the assay detection limit and measuring range. The enhanced chemiluminescence system for the determination of human chorionic gonadotropin is an efficient assay which agrees well with our routine assay. In connection with an automatic sample processor it enables an advanced and versatile system for the determination of human chorionic gonadotropin in laboratories with large series. The system is rapid, easy to handle and apparently free from interference.

Choriocarcinoma↗
PubMed1985

[Immunophenotyping of lymphocyte subpopulations using monoclonal antibodies in an analytical flow cytometer: evaluation of the method and reference values].

Analytical flow cytometers which are easy to operate, and monoclonal antibodies specific for cell surface determinants of lymphocytes, offer a simple and rapid method for the identification of the immunological phenotype of lymphocyte subsets. We investigated mononuclear cells isolated from EDTA-blood bv density gradient centrifugation. The intraassay precision (n = 12) of the determination by means of monoclonal antibodies directed against T-cells (Leu 4), T-helper/inducer-cells (Leu 3 a, b), T-suppressor/cytotoxic cells (Leu 2 a) and cells of the 'NK'-phenotype (Leu 7) varied between 2.2 and 7.9%. Studies using the subset markers Leu 2a and Leu 3a, b conjugated either to fluorescein isothiocyanate (FITC) or to phycoerythrin (PE) showed comparable results for both subsets. Dual immunofluorescent analysis using two different antibodies conjugated to contrasting fluorochromes resulted in slightly higher fractions of T-helper/inducer-cells (Leu 3a, b-FITC: a = 0.97, b = 3.18, r = 0.98) and T-suppressor/cytotoxic cells (Leu 2 a-PE: a = 0.99, b = 2.22, r = 0.97) compared with single immunofluorescent analysis. We found no constant association to explain this statistically significant discrepancy (p less than or equal to 0.0002). The investigation of 100 controls established the following reference values for the fraction of lymphocyte subsets (median, 95%-interval): T-cells 0.75 (0.57-0.87), T-helper/inducer-cells 0.47 (0.34-0.63), T-suppressor/cytotoxic cells 0.26 (0.15-0.42), 'NK'-cells 0.16 (0.04-0.34). The corresponding absolute numbers of cells are: T-cells 1.300 (0.730-2.240), T-helper/inducer-cells 0.820 (0.44-1.540), T-suppressor/cytotoxic cells 0.450 (0.190-0.915), 'NK'-cells 0.300 (0.060-0.670).

Adult↗
PubMed1984

[Computer-assisted findings on protein electrophoresis on cellulose acetate film].

Until a short time ago efficient computer assisted reporting of electrophoretograms was not possible owing to the lack of appropriate technology. By integrating a fully mechanized electrophoresis system into the laboratory data processing system of a centralized institute of clinical chemistry, the separation and the interpretation of results can be performed for 300 samples per day. The interpretation is based upon available patient data (specified clinical diagnoses, previous results), calculated fractions and analysis of the electrophoretic curve in the area of albumin and the beta- and gamma-globulin fraction. In this way it is possible to classify hereditary bisalbuminaemias and to detect transient bisalbuminaemias and monoclonal gammopathies. Diagnostic indications of specific dysproteinaemias and defect proteinaemias are printed on the report form if individual serum protein fractions and the total protein content are changed specifically. The results of the different electrophoretic fractions, the total protein and a set of possible alterations of the curve are numerically coded according to the scaled biochemical ranges in five definite sections or to a decision matrix (alteration 'given' or 'not given'), respectively. The composed 'result patterns' are matched with preassigned 'reference patterns' stored in the computer file. The procedure is efficient and adaptable to other areas of analysis.

Albumins↗
PubMed1983

A data processing system adapted to the special needs of the emergency laboratory.

A data processing system for the emergency laboratory was integrated in our clinical laboratory computer system, its prime objective being the service requirements of the laboratory. It included the possibility of simultaneous optical reading of request forms and on-line capturing, processing, and printing of laboratory test data. Priority request forms, which allow the clinician to specify the interval by which emergency test results must be available, are registered by an optical reader and arranged according to urgency by the computer. The production of worksheets is replaced by visual display of information required for accurate specimen analyses on a large colour TV screen. The individual processing status of all tests from as many as 30 request forms is displayed in a colour code. For process control the updated delay time for test performance is faded in. All reports are produced by direct machine transfer of verified test results. For security purposes all steps of sample processing (request, result, report) are recorded via line printers outside the emergency laboratory. The capacity of the computer for managing sample and data processing reduces the work load for technicians. This results in a reduction of the turn-round time of tests. 95% of all requested tests are performed and reported within the requested time period and in emergencies, test results are available within 5-10 min. There has been no major breakdown of the system in over one year of use.

Computers↗
PubMed1981

[Optimization of sample splitting in a centralized clinical chemical institute (author's transl)].

Mechanized sample splitting machines controlled by a laboratory data processing system have been realized in only a few centralized laboratories. Bottlenecks and mistakes in sample processing are avoided by means of direct machine readable identification and parallel splitting of the secondary tubes. Our previous experience has shown that a strategy for sample splitting has to go far beyond these basic functional requirements. The splitting process must be suited to the organization of the particular laboratory, and it must be adjusted to deal with problems of individual samples containing analytically interfering substances, or variable splitting may be required in cases of inadequate sample volumes. In addition to sample identification, the secondary tube has to be coded with the date and the type of material. This allows cumulative on-line processing and series of analyses of different materials. A suitable positional arrangement of containers for control material must be born in mind for quality control performances. We have realized these additional requirements by means of a consequent mutual adaptation in the layout of the request form (marking of priority and additional information), the file structure of the data processing system and the control program of the sample splitting machine.

Chemistry, Clinical↗
PubMed1979

[The significance of determining antibodies to acetylcholine receptor in myasthenia gravis (author's transl)].

The sera of 65 patients with myasthenia gravis (MG) were analysed for antibodies against the nicotinic acetylcholine receptor (ACh-R) using an immunoprecipitation assay (125I-alpha-bungarotoxin bound to human ACh-R as antigen). In 91% of MG sera elevated antibody titers were found ranging up to 500 times reference values. A control group of 77 patients showing various autoimmunological phenomena had ACh-R antibody concentrations within the reference range. The demonstration of antibodies against ACh-R provides a sensitive and highly specific tool for the diagnosis of MG. In addition, the test is helpful in following patients under treatment with immunosuppressive drugs or plasmapheresis. Antibodies against striated, smooth, or heart muscle (indirect immunofluorescence test) are much less sensitive and nonspecific for the diagnosis of MG.

Acetylcholine↗
PubMed1978

[Creatine kinase isoenzymes: idiopathic occurrence of creatine kinase BB activities in patient serum (author's transl)].

By differentiation of creatine kinase isoenzyme activities in sera using immunological methods the published data about occurrence of creatine kinase BB activities in patients with different diseases or after surgical treatment, respectively, cannot be verified in general. With a frequency in the order of magnitude of 1 : 1000 in the serum of old patients (age 57 to 85 years with one exception), however, creatine kinase BB activities can be measured. The range of activities is 15 to 234 U/1, or 19 to 94% of total creatine kinase activities, respectively. At the present time there is no possibility to correlate this phenomenon to any specific disease. These cases are detected by abnormally high results of CK-MB activity measurements with the immunoinhibition test (range 60 to 202% of total creatine kinase activities) which lead to a repeated analysis using immunoprecipitation. The results of all CK-BB patients investigated till now are presented and discussed.

Adult↗
PubMed1978

[Isoenzymes of creatine kinase: distribution in the skeletal muscle and in sera of patients with muscular diseases or damages (author's transl)].

In skeletal muscle isoenzymes of CK were determined by immunprecipitation and chromatography. The activity of CK-MB was between 17 and 47 U/g muscle, corresponding to a quota between 2,1 and 4,2% of the total activity. In sera of patients with muscular dystrophy, polymyositis, hypothyroidism, after arterial embolism, epilepsy, hyperventilation, operations and polytrauma with and without injury to the thorax isoenzymes were measure by immune precipitation- and immune inhibition-test. The percentage of CK-MB in all sera was less than 6% of the total CK-activity (range: 0 to 6%). Only patients in the first day after neurosurgical operations showed a quota till to 6.5% CK-MB. In serum of patients after polytrauma without injury to the thorax the percentage of CK-MB ranged from 0-5.7% while after polytrauma with injury to the thorax and a reasonable suspicion of a damage to the myocardium this quota was between 5.1 and 23.6% of the total activity. CK-BB activity was not detectable in any cases. Therefore a disease or damage of the skeletal muscle is more probable, if the percentage of CK-MB in less than 6%, because in sera of patients with myocardial infarction in the first 48 h after beginning of the symptoms this quota of CK-MB in the most cases in more than 6%.

Creatine Kinase↗
PubMed1978

[Studies of activity kinetic of isoenzyme CK-MB in serum after myocardial infarction (author's transl)].

We investigated the activity kinetics of CK-total and CK-MB in 83 patients with proven myocardial infarctions. Serial serum samples were taken at intervals of 2--6 h. The activity of isoenzym CK-MB was determined by means of the immunological inhibition method. CK-MB activity was determined in all patients. The mean peak activity of CK-MB was 65 U/l (range: 9-241 U/l). At the time of peak CK-MB activity the mean percentage CK-MB activity was 13.2% (range: 3.4--21.7%). The CK-MB activity reached its peak at 17.4 h (range: 3.0--32.5 h) after the onset of retrosternal pain. This is 1.4 h after peak CK-total activity. The mean disappearance rate constant for CK-MB (n = 31) was found to be 9.3 X 10(-4) U/min with a large individual variation. This value corresponds to a half life of 12.5 h (CK-total: 15.5 h). The determination of CK-MB activity is therefore only of diagnostic significance within 48 h of possible myocardial occurrence. Moreover, isoenzyme CK-MB is not found exclusively in myocardium. For this reason it is better to use the percentage CK-MB activity in the differential diagnosis of myocardial infarction. With 80% of the patients this value is greater than 6% within 36 h of proven myocardial infarction.

Circadian Rhythm↗
PubMed1978

[The significance of beta2-microglobulin and carcinoembryonic antigen in the diagnosis of the carcinoma of the pancreas (author's transl)].

The concentration of beta2-microglobulin (beta2m) and carcinoembryonic antigen (CEA) was measured radioimmunologically in the sera of 79 patients with malignant disorders and 15 patients with chronic pancreatitis. Elevated levels of beta2m and CEA were found in 11 out of 22 patients with carcinoma of the pancreas, which sets off this malignancy from chronic pancreatitis and other malignant tumors. Only 3 patients with carcinoma of the pancreas exhibited serum levels within the normal range for both parameters and none of the patients with chronic pancreatitis was shown to have elevated levels of beta2m. The simultaneous determination of beta2m and CEA suggests itself for the diagnosis of pancreatic malignancy especially in the case of a tentative diagnosis of a pancreatic tumor.

Beta-Globulins↗