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Biomedical subjects

M Frank

Publications and source records attributed to M Frank.

At least 343 records · Page 19Linked to original sources
PubMedDate not supplied

Energy-sensitive cryogenic detectors for high-mass biomolecule mass spectrometry.

Energy-sensitive calorimetric detectors that operate at low temperatures ("cryogenic detectors") have recently been applied for the first time as ion detectors in time-of-flight mass spectrometry. Compared to conventional, ionization-based detectors, which rely on secondary electron formation or the charge created in a semiconductor, cryogenic detectors measure low-energy solid state excitations created by a particle impact. This energy sensitivity of cryogenic detectors results in several potential advantages for TOF-MS. Cryogenic detectors are expected to have near 100% efficiency even for very large, slow-moving molecules, in contrast to microchannel plates whose efficiency drops considerably at large mass. Thus, cryogenic detectors could contribute to extending the mass range accessible by TOF-MS and help improving detection limits. In addition, the energy resolution provided by cryogenic detectors can be used for charge discrimination and studies of ion fragmentation, ion-detector interaction, and internal energies of large molecular ions. Cryogenic detectors could therefore prove to be a valuable diagnostic tool in TOF-MS. Here, we give a general introduction to the cryogenic detector types most applicable to TOF-MS including those types already used in several TOF-MS experiments. We review and compare the results of these experiments, discuss practical aspects of operating cryogenic detectors in TOF-MS systems, and describe potential near future improvements of cryogenic detectors for applications in mass spectrometry.

Calorimetry↗
PubMedDate not supplied

Prevalence and epidemiological significance of Trypanosoma cruzi infection among Latin American immigrants in Berlin, Germany.

A survey was conducted among Latin American immigrants living in Berlin to investigate the presence of Trypanosoma cruzi infection and to evaluate possible risk factors. One hundred persons were interviewed about risk factors (rural origin, contact with the reduviid bug) and evaluated serologically. The sera were tested with indirect immunofluorescence (IIF). All samples seroreactive with IIF were additionally evaluated with an ELISA for T. cruzi antibodies. To rule out cross-reactivity all seroreactive sera were tested with IIF for Leishmania infantum antibodies. Two persons were seroreactive in IIF and ELISA and three were seroreactive in the IIF only. The overall seroprevalence according to WHO criteria was therefore 2% (2/100). All samples were negative for Leishmania antibodies. Only one of the seropositive persons showed a risk factor for T. cruzi infection in their medical history. These findings suggest that routine serologic testing of Latin Americans is indicated to reduce the risk of transmission by blood transfusion and congenital transmission.

Adult↗
PubMedDate not supplied

Steroid-induced mesenteric lipomatosis.

A patient undergoing chronic corticosteroid therapy presented with mesenteric lipomatosis that simulated malignant masses. Computerized tomography was instrumental in identifying these apparent tumors as benign fatty deposits. The spectrum of lipomatous abdominal lesions amenable to diagnosis by computerized tomography is reviewed.

Adrenal Cortex Hormones↗
PubMedDate not supplied

Self-monitoring of blood glucose: how accurate are children with diabetes at reading chemstrip bG?

Accuracy of self-monitoring of blood glucose (SMBG) using Chemstrip bG (Bio-Dynamics, Indianapolis, Indiana) was studied in 90 randomly selected children with insulin-dependent diabetes mellitus (IDDM). For 28 children (mean age 8.3 +/- 3.6 yr) a parent routinely read the Chemstrip at home. The remaining 62 children (mean age 13.7 +/- 2.8 yr) read the Chemstrip themselves. Each child or parent analyzed 20 capillary blood samples using Chemstrips and answered a questionnaire on SMBG. The accuracy of SMBG of the group was high (mean correlation coefficient = 0.89 +/- 0.05), but consistency of measurement was variable (mean standard deviation = 1.90 +/- 0.57) and there was a general tendency to underread Chemstrips (mean y-intercept = 1.05 +/- 1.48; mean slope = 0.80 +/- 0.17). For each subject, 0-65% (mean of 34%) of readings were within 10% of the laboratory measurement, and 17-100% (mean 68%) within 20%. These results indicate that most subjects were fairly accurate in reading Chemstrips; however, analysis of accuracy is useful in identifying individuals who are inaccurate or inconsistent in SMBG. Continuing supervision of SMBG is necessary in children with IDDM.

Adolescent↗
PubMedDate not supplied

Psychiatric emergency services: a case study.

In this chapter we have attempted to describe one emergency service as it has evolved. It is generally recognized as a very good service, and yet, as the vignettes demonstrate, there are continuing administrative problems. It is our belief that these difficulties and dilemmas are representative of those faced by administrators of emergency psychiatric services, and we view them as a continuing challenge to those committed to clinical administration.

Adult↗