Biomedical subjects

M Helbig

Publications and source records attributed to M Helbig.

21 records · Page 2Linked to original sources

PubMed1995

Diagnosis of Echinococcus multilocularis infection by reverse-transcription polymerase chain reaction.

Alveolar echinococcosis is a life-threatening parasitosis occurring in countries in the Northern hemisphere. The diagnosis of an Echinococcus multilocularis infection is routinely performed by radiological techniques and by the detection of specific antibodies in the sera of infected patients. However, because serodiagnosis fails in 5%-10% and radiological techniques are difficult to interpret in some cases, we developed a polymerase chain reaction for the detection of echinococcal-specific messenger RNA from fine-needle biopsy specimens. This technique was applied to the diagnosis of alveolar echinococcosis in a 20-year-old seronegative woman. Detection of messenger RNA not only allowed the diagnosis of echinococcal disease but also proved to be a reliable measure for determining the efficacy of an antiparasitic therapy.

Adult↗

PubMed1993

Serological differentiation between cystic and alveolar echinococcosis by use of recombinant larval antigens.

Two recombinant antigens of the larval stages of Echinococcus granulosus and Echinococcus multilocularis, termed EG55 and EM10, respectively, were applied for serodiagnosis and serological differentiation between parasitic infections caused by the metacestode tissue of both tapeworms. Antigen EM10 is synthesized by E. multilocularis larvae. Antigen EG55 represents the recombinant form of the low-molecular-weight subunit of antigen B, which is an Echinococcus genus-specific antigen. Both recombinant antigens were expressed as glutathione S-transferase fusion proteins. A sandwich enzyme-linked immunosorbent assay with monoclonal antibodies against EM10 and EG55 as capture reagents for the recombinant antigens was established and was evaluated with 74 serum samples from patients with histologically confirmed alveolar echinococcosis and 63 serum samples from patients with histologically confirmed cystic echinococcosis. A sensitivity of 93.2% and a specificity of 96.8% were achieved for the serodiagnosis of alveolar echinococcosis. Cystic echinococcosis could be detected with a sensitivity of 89.1% and a specificity of 98.6%.

Animals↗

PubMedDate not supplied

Quantification of transient quadratic phase couplings within EEG burst patterns in sedated patients during electroencephalic burst-suppression period.

The time dynamics of the quadratic phase coupling within burst patterns during electroencephalic burst-suppression has been quantified. It can be shown that a transient quadratic phase coupling (QPC) exists between the frequency ranges 0 to 2.5 and 3 to 7.5 Hz and between the frequency ranges 0 to 2.5 and 8 to 12 Hz. The QPC can be explained by an amplitude modulation, where the slow rhythm modulates the rhythmic activities with a higher frequency. By means of time-variant bicoherence analysis, a strong phase-locking between the modulating and the modulated component can be identified. The phase-locking is demonstrable within the first 250 ms after the burst onset and comes up to the maximum between 750 and 1250 ms. The effect is maintained over the whole first part of the burst (2 s) with a decreasing tendency after 1250 ms. All these effects cannot be found in the EEG before entering the burst suppression period (BSP). The transient coupling phenomena in the EEG bursts during BSP can be regarded as indicators for short-term interrelations between the underlying electrophysiologic processes.

Brain↗