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T Auer

Publications and source records attributed to T Auer.

At least 37 records · Page 2Linked to original sources
PubMed1995

Properties of the 5'-->3' exonuclease/ribonuclease H activity of Thermus thermophilus DNA polymerase.

The recombinant 94 kDa Thermus thermophilus DNA polymerase (rTth pol) was found to release [33P]UMP when incubated with a RNA.DNA hybrid containing a [33P]UMP-labeled RNA strand. The RNase H activity was optimally active in the presence of low monovalent salt concentrations and when Mn2+ was used as the divalent cation activator. RNase H activity also was observed when Mg2+ replaced the Mn2+, but to a much lesser extent. A 60 nucleotide long, 5'- or 3'-radiolabeled RNA or DNA oligomer hybridized to a complementary DNA oligomer was used to determine the mode of digestion. The radiolabeled RNA.DNA hybrid or DNA.DNA duplex was incubated with rTth pol using various metal ion conditions and different incubation times. The DNA.DNA duplex showed very little enzymatic cleavage by rTth pol regardless of the Mn2+ or Mg2+ concentration. However, nearly complete digestion of the RNA.DNA hybrid was observed over a wide Mn2+ concentration range, thus demonstrating a preferential degradation of the RNA.DNA hybrid vs the DNA.DNA duplex. Time course reactions of the enzymatic digestion of the 3'-labeled RNA.DNA hybrid or DNA.DNA duplex by rTth pol indicated that digestion of the substrates occurred exonucleolytically in the 5'-->3' direction.

Base Sequence↗
PubMed1995

Two-dimensional blood flow determinations in allergic reactions using laser Doppler scanning.

The new technique of laser Doppler scanning (LDS) provides a 2-dimensional pattern of cutaneous microcirculation, which offers a visual image and can quantify the intensity and expansion of perfusion. With the help of this technique, we examined the microcirculatory pattern of Type IV reactions to recall antigens, which were applied using a test stamp (Multitest Merieux). The measurements were performed before application of the test stamp as well as 10 min, 24, 48 and 72 h afterwards. The inflammatory hyperemia was evaluated using LDS and unidimensional laser Doppler fluxmetry. The diameter of the inflammatory infiltrate was quantified by means of palpation, the thickness by means of high-resolution 20 MHz sonography. The clinically visible erythema was measured planimetrically. An unspecific hyperemia resulting from the trauma of the stamp revealed no evident infiltrate under sonography 10 min after the test application. Depending of the individual reaction, the mean flux and the expansion of the hyperemia were at their peak after 48 h. The flux values were at a maximum in the center of the inflammatory reaction and dropped continuously toward the periphery. The area of the hyperemia seen in the LDS image was significantly larger than the expansion of the erythema measured planimetrically, but there was a significant correlation. The perfusion correlated significantly with the infiltration diameter (24 h, 48 h, 72 h) and the infiltration thickness 48 h after testing. All in all, it was possible to measure directly and without touching the skin and to quantify a subclinical pattern of skin perfusion as a response to and inflammatory reaction on a 2-dimensional display.

Adult↗
PubMed1995

CMV antigenemia (the lower matrix protein PP65), a marker for the guidance of antiviral therapy in cytomegalovirus disease after orthotopic heart transplantation.

During CMV viremia, the CMV specific lower matrix protein CMV pp65 can be detected in the nucleus of polymorphonuclear cells. A relationship has been found between the number of CMV pp65 positive cells, the clinical course and the effect of antiviral treatment on CMV disease. From 1990, heart recipients (triple drug therapy) were screened for CMV pp65 (antigenemia, according to the method described by The et al.), anti-CMV-IgM and -IgG. Tests were repeated at least every 4 weeks. Group 1 consisted of 23 patients who had been transplanted at least one year before the introduction of CMV testing as described. Between 1990 and 1992 26 patients were followed up during the first year after transplantation and represent group 2. In group 1, 1184 antigenemia assays were performed and 13 tested positive. In group 2 (1195 tests, 261 positive results), 20 out of the 26 recipients tested positive for CMV pp65. Without preceding evidence of a positive CMV pp65, no rise of IgM or IgG antibodies was observed. The time until the first antigenemia (time from detection until a subsequent test remains negative); 13 were found in group 1, 84 in group 2. In group 2, 46 episodes of antigenemia (mean duration 24.5 +/- 27.1 days) consisted of more than 1 consecutive positive result of the antigenemia assay (4.8 +/- 4.1). During these episodes the white blood cell count was 3460 +/- 1790/mm3. After the episodes, the mean leucocyte count was 6320 +/- 1870/mm3. The detection of CMV antigenemia indicated the initiation of antiviral treatment (hyperimmune globulin and ganciclovir). Therapy was stopped again when the antigenemia assay tested negative again. Antigenemia disappeared in all patients after initiation of antiviral treatment, CMV disease was not observed. CMV antigenemia mainly cumulates within the first year after heart transplantation. Antigenemia directed antiviral therapy does not prevent infection or repeated antigenemia but prevents CMV disease after heart transplantation.

Adult↗
PubMed1995

Cytomegalovirus after heart transplantation: definitions for the guidance of antiviral therapy.

Besides the current classification of cytomegalovirus (CMV) infection and disease we defined "CMV antigenaemia" as the marker for initiation of antiviral therapy (CMV hyperimmune globulin 2 ml/kg/d and ganciclovir 1000 mg/d), and "episodes of CMV antigenaemia"(the time from detection of antigenaemia until a subsequent antigenaemia assay tested negative again) indicated the time period of antiviral treatment. Patients were at highest risk for antigenaemia at day 38.2 +/- 20.9 after heart transplantation. We observed 50 episodes of antigenaemia in 18 patients. The mean duration was 7.3 +/- 6.4 days. No antigenaemia associated symptoms and no anti-CMV IgM was observed without preceding evidence of antigenaemia. Antigenaemia-associated symptoms and antigenaemia disappeared after antiviral therapy was initiated. Our therapy did not prevent CMV infection, but despite the repeated evidence of active CMV infection, no patient suffered CMV disease.

Antigens, Viral↗
PubMed1994

Laser Doppler imaging of axial and random pattern flaps in the maxillo-facial area. A preliminary report.

Objective, non-invasive examination, techniques in addition to clinical parameters, are required to follow-up the wound healing of flaps. With the new laser Doppler Scanner (LDI DIM 1.0 Lisca Development AB, Sweden) it is possible, for the first time, to measure and image the microcirculation continuously, non-invasively and without contact with the wound, in an area of 12 cm square maximum. We performed measurements and simultaneous two-dimensional imaging of the microcirculation 24, 48, 72 h and 5 and 14 days postoperatively in 20 patients, who had had reconstruction procedures performed using random or axial pattern flaps. The perfusion diagrams were correlated to the clinical appearance. Necrotic areas, venous stasis and normal course of wound healing can be clearly visualized and differentiated from one another. The new laser Doppler imaging system seems to be an excellent aid for following up and planning of flaps in plastic and reconstructive surgery.

Adolescent↗
PubMed1994

High indoor radon concentrations in an Alpine region of western Tyrol.

In a village in western Tyrol, Austria (Umhausen, 2,600 inhabitants), unusually high indoor radon concentrations were measured, and the lung cancer mortality rate was found to be higher than that of the total population of Tyrol (620,000 inhabitants). Annual means of radon concentrations were found to be particularly high in the area between the two rivers Otztaler Ache and Hairlachbach, geologically an alluvial fan of a giant rock slide of granitic gneisses (area A, median of annual means on the ground floors: 1,868 Bq m-3); radon concentrations were comparatively low in the rest of the village (area B, median of annual means on the ground floors: 182 Bq m-3). On the basis of these medians, the annual exposures were calculated according to the ICRP model (area A: 58.8 x 10(5) Bq h m-3; area B: 5.7 x 10(5) Bq h m-3). Data taken from the Cancer Registry of Tyrol were used to determine the age- and sex-standardized lung cancer mortality rate (area A: 6.17; area B: 1.43).

Air Pollution, Indoor↗
PubMed1994

Evaluation of the efficacy of H1 blockers by noninvasive measurement techniques.

BACKGROUND: Evaluation techniques for determining the strength of action and the onset of activity of H1 receptor blockers have not yet been sufficiently standardized. OBJECTIVE: The clinical efficacy of the H1 receptor blocker loratadine was to be measured upon a wheal response subsequent to an intracutaneous injection of 0.1 ml histamine (0.1%). METHODS: In a pilot study, 10 patients were treated with the H1 receptor blocker loratadine for a period of 7 days. Various noninvasive measurement techniques, i.e. 20-MHz sonography, laser-Doppler flowmetry, chromatometry using the Lab* system and computer-assisted planimetry, were applied to provide a quantitative evaluation of the wheal and the marginal erythema. Using these quantification methods, the development of the urticarial reaction 20 min after injection and its decline were evaluated. RESULTS: The urticarial reaction was reduced substantially under treatment with 10 mg loratadine over a period of 7 days. The methods we used could accurately quantify different aspects of the urticarial reaction noninvasively. CONCLUSIONS: All of the chosen measurement techniques are widely recognized. For objective assessment of the urticarial reaction with high-frequency ultrasound, we recommend the measurement of the distance between skin entrance echo and fascia since the demarcation of the wheal is often impossible by ultrasound. In order to improve comparison of results of various workgroups in the future, we therefore suggest the use of the selected combination of noninvasive procedures as a standard for evaluating the efficacy of H1 receptor blockers.

Administration, Oral↗
PubMed1994

Psoriasis vulgaris in 50 MHz B-scan ultrasound--characteristic features of stratum corneum, epidermis and dermis.

One hundred and forty fully developed, non-treated plaques of psoriasis vulgaris from the arms and legs of 22 patients were examined using 50 MHz B-scan ultrasound and compared with the images from adjacent, clinically normal skin. To visualize the dermis, high pre-amplification (digitization range 200 mV) was used, determined according to A-scan images. For evaluation of epidermal phenomena, low pre-amplification (digitization range 380 mV) was chosen in order to avoid overmodulation of the skin entry echo. In 10 patients, sonographic images were compared with histological sections from the exact same planes at the same magnification. At low pre-amplification, the skin entry echo is displayed as a markedly widened, frequently interrupted band composed of spots varying in thickness, height and echo density. Within these spots, several lamellae can be observed, represented as fine, echo-rich lines stacked one upon another. These phenomena correspond histologically to focal hyperparakeratosis, scaling and cracking of the stratum corneum. Due to the low amplification of the echo-signal the dermis is not visible. High pre-amplification allows evaluation of dermal changes. Below the entry echo there is an echopoor band (EPB) corresponding to the sum of acanthosis and infiltrate in the upper dermis. Underneath the EPB the dermis is represented as a zone with scattered internal echoes which are less intense than in normal skin. Dorsal shadows are typically present. They are artifacts emanating from epidermal regions with marked hyperkeratosis and disappear when the sonographic characteristics of the epidermis are changed, for instance by application of ointments prior to sonographic examination.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

The hyperperfusion of the psoriatic plaque correlates histologically with dilatation of vessels.

We examined psoriatic lesions on the upper legs in 20 patients, using a two-dimensional Laser-Doppler-Scanner (Laser Doppler Perfusion Imager LDI, Lisca Development, Linköping/Sweden). The plaques were evaluated weekly during therapy with dithranol. Five plaques were reconstructed three-dimensionally before and after therapy (reconstruction program ANAT 3D, SIS, Münster, Germany). The psoriatic plaque was represented in the Laser Doppler Perfusion image as a sharply demarcated, hyperperfused area. The perfusion of the plaques dropped during therapy with dithranol to just slightly increased values, compared with normal skin (2.04 arbitrary units AU, healthy skin 1.1 AU). Using three-dimensional reconstruction, we investigated the volume of dermal vessels and the density of papillae. When compared, the volume of papillary vessels was twice as large in psoriatic as in healthy skin. The number of the papillae per square millimetre, detected by three-dimensional reconstruction, was not reduced significantly during therapy. We think that the increased perfusion of the psoriatic plaque is due to the combination of morphological (dilatation of vessels), dynamic (increased blood flow) and optical effects (reduced scattering and increased sampling depth of the laser-beam in acanthotic tissue).

Anthralin↗
PubMed1994

[Sound frequency analysis for identification of venous air embolism].

Air emboli occurring during surgery are considered to be life-threatening incidents. With the aim of achieving acoustic identification of venous air emboli, a frequency analysis of the sounds induced by an air embolism (millwheel murmurs) as well as of all other unusual sounds, was undertaken during 20 operations, and in experiments with animals. The frequency spectra of the sounds induced by air emboli are characterised by an increase in the amplitudes in the frequency range 1,100 to 3,000 Hz, while the amplitudes of normal heart sounds continuously decrease with increasing frequency. The frequency spectrum was examined for characteristics using an electronic filter system. The sounds induced by air emboli can be clearly distinguished from normal heart sounds. During operations on patients, suction sounds occur, the frequency patterns of which are not easy to distinguish from those of embolus-induced sounds, although an acoustic distinction can be made via a stethoscope or a loudspeaker. With optimal adjustment of the filter system, 73 out of 81 (90%) embolism-related sounds were correctly identified in animal experiments. On no occasion were normal heart sounds wrongly identified as due to an embolus. However, an embolus sound was frequently mimicked by interfering sounds such as those produced by artificial respiration, and other ambiend sounds. By modifying the oesophageal catheter to achieve optimal suppression of interfering sounds, this filter system could be developed into an alarm.

Animals↗