Search PubMed⌕ Search

Biomedical subjects

H Keller

Publications and source records attributed to H Keller.

At least 217 records · Page 12Linked to original sources
PubMed1987

[Basophil degranulation test in suspected mould allergy].

Mould allergy is often linked with a pattern of signs and symptoms of the upper airways, especially of the nose. Since exact aetiopathological correlations are hard to determine by anamnesis only, further allergy diagnosis is very important. This often yields marked differences between intracutaneous and nasal provocation tests. The human basophil degranulation test (HBDT) now offers a further method of in-vitro diagnosis. This test can explore the condition of the basophils, which are of great importance for the allergic reaction besides the mast cells, and the ability of these cells to degranulate in the presence of a corresponding allergen. We investigated the correlations between the results of HBDT, intracutaneous skin test and nasal provocation test. 30 patients with perennial rhinitis suspected of being caused by moulds were tested using 4 mould mixtures. We found many more positive results with the nasal test and HBDT than with the skin test. The corrected contingency coefficient after Pearson showed a stronger correlation of HBDT to the incracutaneous skin test and to the nasal provocation test than between the two in-vivo methods. This is thought to be due to a wider sensitivity spectrum of the degranulation test which can possibly also measure other allergy reactions than type I after Commbs and Gell. We consider HBDT to be a valuable additional tool in allergy diagnosis. We should welcome a wider range of different allergenic test slides and a standardisation of allergenic extracts.

Adolescent↗
PubMed1987

Analysis with solid phase reagent carriers.

Solid-phase chemistry is a category of analytical techniques characterized by three features: dry reagents fixed on or in an inert carrier; they are transformed into a liquid state of reactivity solely by fluid from the sample, movement of fluid in the carrier happens through capillary surface forces. A number of industrial laboratories have adapted these technologies to a majority of parameters of blood or serum respectively. The most frequently used measuring devices are new developed reflectometers; in one system (Ektachem) disposable ion selective electrodes have been newly developed in addition. The most important systems on the market are Ektachem (Kodak), Reflotron (Boehringer, Mannheim) and Seralyzer (Ames). These systems differ with respect to the construction of the reagent carriers and of the reflectometers. Solid-phase chemistry has the following advantages over the conventional analytical techniques: The sample volume is small, and the instrumentation is not complicated. The reagents are ready for use, and one system permits the use of whole blood without centrifugation. In this way it is possible to perform decentralized analyses at the patient's bedside, or in the physician's office. The disadvantages are the complete dependency of the user on the manufacturer with respect to the methodology and the quality of the reagents and instrumentation, the relative high price of the test-elements, and the limited possibility for the processing of long series. Additional problems are associated with quality control and drug interference. Nevertheless it can be expected that in the future increasing numbers of clinical chemical analyses will be performed by solid-phase chemistry, especially in general practice.

Blood Chemical Analysis↗
PubMed1986

[Does the determination of basal TSH level replace the TRH test?].

With the help of the newly developed "supersensitive" assays for thyrotropin it is possible to determine concentrations down to 0.03 mU/l. Patients with a manifest hyperthyroidism show, as a rule, very low TSH levels and they react not at all or only very weakly to TRH stimulation. Therefore, various authors have claimed that estimation of the basal TSH level is sufficient as a screening test for the exclusion of a hyperthyroidism. To check the reliability of this statement we determined the reference interval of the parameter "basal TSH". It is a log-normal distribution; the reference interval of healthy people (95. percentile) is 0.25-4.0 mU/l. The TSH response to TRH stimulation also follows a log-normal distribution, the reference interval being 3.0-20 mU/l. There is a poor correlation between both parameters (r = 0.83). Histograms of populations with reduced, normal, or increased reactivity to TRH stimulation show broad overlapping zones. A valid prediction (with a plausibility greater than 90%) of the TSH response to TRH stimulation is therefore possible in the extreme ranges only (less than 0.2 mU/l for reduced, greater than 5 mU/l for increased reactivity respectively). In between there is a wide "gray zone", where reliable prediction is not possible on the basis of laboratory data only (without clinical findings).

Adult↗
PubMed1986

Reflection photometry of oxygen supply of skin flaps and replanted fingers.

A method is presented that allows noninvasive, direct, and rapid control of the oxygen supply of the skin, by registration of cutaneous hemoglobin spectra. Axial pattern flaps, free transfer flaps, and replanted fingers were investigated using this method intra- and postoperatively. The results showed that with such a control, complications in the revascularization and healing process can be detected fairly early, so that therapeutic measures can be taken.

Fingers↗
PubMed1986

A distribution-free, multivariate discriminating method. Initial experience with the discrimination of patient groups by 2 or more clinical chemical parameters.

We communicate a distribution-free quasi graphic procedure for obtaining a linear discriminating function. The method is based on the following considerations: Suppose a group A is to be separated from a group B using two parameters X and Y. The centre of each group is defined as the median (or mean or mode) of its points. Of all straight lines passing through any point of A and any point of B those are retained which intersect the segment joining the centres of A and B. For each of these the number of wrongly allocated points is calculated (i.e. the points which do not lie on the same side of the straight line as their group centres). In this way one obtains straight lines with maximal separating power (for the two groups given). Finally, each optimal line is rotated in such a way that its defining points are also correctly allocated. If more than two parameters are available a stepwise procedure can be used: the distance from the separating straight line obtained from the first two parameters is introduced as a new parameter, which is then combined with the third parameter to yield a new discriminating function which depends on all three parameters. Iterating this step one can combine any number of parameters. The method was implemented on a personal computer. It was first applied to a textbook model (chances of survival for M. haemolyticus neonatorum estimated by concentrations of haemoglobin and bilirubin in cord blood).(ABSTRACT TRUNCATED AT 250 WORDS)

Calcium↗
PubMed1986

[Bone banks. Equipment, tissue collection, cold preservation, organization, safety].

A well-organized bone bank for cryoconservation is a proven and safe procedure, which is best suitable for emergency surgery. If the indication is correct and donor selection carefully proved, it is an efficient procedure without great problems. For donor selection, the history of the patient, a clinical examination and serological tests are very important, in addition to an aseptic procurement and continuous maintenance of temperature in the freezer. The freezer temperature must be kept below the eutectic point of bone (-28 degrees C). At this temperature all of the individual bone tissue structures are frozen, and bone can be preserved for 1 year in this way. We prefer a cryoconservation at -39/49 degrees C. In the Department of Traumatology of the University in Freiburg, in the last 16 years more than 1000 homologous bone grafts have been performed. Although in the first weeks consolidation is delayed, the rate of complications after bone transplantations is low. The great advantage is the availability of homologous (allogenous) cancellous bone and cortical bone chips at any time, especially for the treatment of polytraumatized patients.

Accident Prevention↗
PubMed1986

[Effect of the angiotensin II analog saralasin before donor nephrectomy on primary transplant function].

Cadaver kidney donors were treated with Angiotensin II-Analogon-Saralasin before nephrectomy in order to reduce the rate of acute renal failure. Eighteen (64.3%) of the recipients of the 30 donor kidneys pretreated with Saralasin were primarily free from dialysis. Six recipients showed acute renal failure. Two donor kidneys never resumed their function and no reports could be obtained on two organs. In the control-group with no pre-treatment, acute renal failure appeared significantly more often (67.3%). Thus only 32.7% of the recipients needed no further dialysis. This difference is statistically significant.

Acute Kidney Injury↗
PubMed1985

[A highly efficient, highly purified duck embryo rabies vaccine].

At the Swiss Serum and Vaccine Institute, Berne, a highly purified rabies vaccine presenting a high content of effective rabies virus glucoprotein antigen has been developed. The new vaccine is derived from embryonated duck eggs (PDEV). Immunizations performed according to the post-exposure schedule recommended for potent rabies vaccines by the WHO (6 injections on days 0, 3, 7, 14, 28 and 90) already induce protective antibody titers on day 14 (greater than 1 IU/ml). Use of the latest radioimmunological methods did not reveal the presence of myelin basic protein in the new rabies vaccine. Due to improvements of its preparation the rabies vaccine PDEV is an economical and highly efficient vaccine involving only a very remote risk of post-vaccinal encephalitis.

Animals↗
PubMed1985

[Criteria for the selection and evaluation of diagnostic tests].

When evaluating the result of a diagnostic test with respect to a reference interval, two additional sources of variability should be taken into account, i.e. the variability of the analytical procedure and the biological variability which comprises an intraindividual and an interindividual component. The test assessment chart presented in this paper is a graphical representation allowing for the simultaneous evaluation of all three variables. In particular, the test assessment chart yields information relating to the effectiveness of a test in early detection of a disease. Moreover, the types of errors inherent in a test may be defined, i.e. either errors of the first type or those of the second type, leading to false positive and false negative results, respectively. The test assessment chart also shows whether repeated measurements improve the result, and whether a test basically is uncertain. Diagnostic sensitivity, specifity, and predictive values of a test may be arrived at if a threshold of discrimination is introduced. An example is discussed relating serum creatinine concentration with glomerular filtration rate. This approach reduces quantitative results to binary ones (positive/negative). More advanced methods of estimating the probability of the existence of a disease have come into use more recently. This bases on the likelihood quotients calculated (class-wise) from test results of well defined groups of patients (and healthy individuals). Examples of calculating the risk for gout attack and of EPH gestosis, depending on serum uric acid level, is presented. The application of the methods for diagnostic support today is restricted, so far, to certain special classes fo clinical problems.

Blood Chemical Analysis↗
PubMed1985

[Immune defect following thymoma. Case description and review].

The clinical and immunologic findings in a 57-year-old woman with hypogammaglobulinemia are described. The immunodeficiency occurred 11 years after surgical removal of an invasive lymphocytic thymoma. The typical findings of hypogammaglobulinemia as a thymoma-associated clinical syndrome are absence of peripheral blood B-lymphocytes and deficiency of plasma cells in bone marrow. However, in our patient peripheral blood B-lymphocytes and plasma cells in bone marrow were within normal limits, while the total number of peripheral blood mononuclear cells was subnormal. This subnormality was found to be a diminution of peripheral blood T-helper cells. Our patient was anergic to a battery of skin test antigens and her lymphocytes showed a decreased in vitro response to mitogen stimulation. In particular, the response to phytohemagglutinin (PHA) was low, but could be improved by the addition of interleukin-2 to the culture medium. Cocultures between patient B-cells and normal T-cells revealed normal function of patient B-cells. However, cocultures between patient T-cells and normal B-cells showed a significant depression of mitogen-induced immunoglobulin synthesis. These results are suggestive of T-helper cell dysfunction. Consequently, in our case the hypogammaglobulinemia was assumed to be secondary to deficient T-helper cell function.

Agammaglobulinemia↗