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Biomedical subjects

B Langkopf

Publications and source records attributed to B Langkopf.

At least 19 recordsLinked to original sources
PubMed1992

[Sonographic evaluation of changes in testicular tissue by ultrasound spectroscopy].

Experimental investigations were carried out under in vitro conditions on 25 normal human testicular specimens and on 60 pathological testicular specimens to ascertain the ultrasound attenuation using an ultrasound spectroscopic measuring technique. The ultrasound attenuation was established by calculating the ultrasound attenuation coefficient alpha. The average values of ultrasound attenuation (alpha) in normal testicular tissue were distinctly lower than in pathologically altered testicular specimens. A comparison of the various pathologically altered testes showed higher attenuation in the case of malignant neoplasms whilst the highest average values of wore recorded for non-neoplastic pathological alterations in the testicular tissue. The results of the investigations show that certain alterations in the tissue can be ascertained by ultrasound spectroscopy. The analysis of further acoustic parameters in future investigations, such as ultrasound back-scattering and velocity, along with the recording of ultrasound attenuation, gives scope for improved assessment of the tissue. Thus ultrasound spectroscopy increases the sonographic accuracy acquired through analysis and the weighing up of symptoms of tissue dependent ultrasound parameters.

Adolescent↗
PubMed1990

[Experimental studies of the effect of fixation time on ultrasound extinction in formalin-fixed testicular tissue].

The influence of fixation time on the ultrasound damping was investigated in vitro in both normal and altered formalin-fixed testicular tissue. By means of ultrasound spectroscopy the ultrasound damping coefficient alpha is estimated. The results of measurements in different time intervals after onset of fixation did show that in both normal and altered testicular tissue only slight changes of ultrasound damping was found. Therefore, the influence of fixation time could be neglected.

Fixatives↗
PubMed1990

[Effect of various fixation agents on ultrasound damping in normal and pathological testicular tissues].

In normal and pathological testicular tissue the influence of various fixing agents (Formalin solution, Bouins solution, Hellys solution, Carnoys solution) concerning the acoustical properties of testicular tissue was examined. By means of an ultrasound spectroscopic measurement technique the ultrasound damping was registered by calculation of the ultrasound damping coefficient alpha. The results show that the most lower alpha values were obtained by fixation with formalin solution as well in normal as in altered testicular tissue. The results of fixation according to Helly, Carnoy and Bouin did show markedly differences. Therefore, the fixation of testicular tissue using formalin solution is the best way for experimental examinations of the ultrasound damping behaviour.

Dysgerminoma↗
PubMed1990

[Influence of examining temperature on the ultrasound attenuation in testicular tissue].

By means of an ultrasound spectroscopic measurement technique the influence of examining temperature on the ultrasound attenuation was experimentally investigated on formalin-fixed normal and altered testicular tissue. In the examined tissue specimens a temperature-dependent change of ultrasound attenuation (alpha on 6 MHz) was found in the temperature area between 10 and 50 degrees C. In the altered testicular tissue a higher damping decline could be observed. On the measuring points the specimens were examined by light microscopy.

Dysgerminoma↗
PubMed1990

[Experimental investigations on the effect of the transducer-specimen distance on the ultrasound attenuation of formalin-fixed testicular tissue].

Additional information on the tissue structure are possible by estimation of sound physical parameters in comparison with normal B-scan ultrasonography, especially the frequency-dependent ultrasound attenuation. The ultrasound attenuation measurements were made on histochemical normal and pathological testicular tissue with changing transducer-specimen distance. No markedly difference in damaging behaviour was found between normal and pathological testicular tissue at different distances.

Fixatives↗
PubMed1990

[The effect of dipyridamole on the results of allogenic kidney transplantation].

In a prospective randomized trial the anti-thrombotic effect of dipyridamole was studied in 64 patients after cadaveric kidney allotransplantation. The frequency of early graft function was significantly higher in the control group, whereas the incidence of arterial and venous thromboses were not different. One-year graft survival could not be improved by dipyridamole. Therefore, dipyridamole should not be recommended in cadaveric kidney allotransplantation.

Cadaver↗
PubMed1990

[Experiences with plasmapheresis in the treatment of vascular rejection following kidney transplantation].

In the first 6 weeks after kidney transplantation 15 patients suffering from vascular rejection were treated by 46 plasmapheres. In transplants with additional interstitial rejection the plasmapheresis was introduced after failure of ATG therapy. In 1 patient no histological confirmation was done. In 4 patients the plasmapheresis was successful and in 6 patients suffering from combined vascular and interstitial rejection the ATG therapy was successful only after initial plasmapheresis. In 4 cases the therapy failed to reverse rejection. The early use of plasmapheresis is recommended to obtain the best results.

Antilymphocyte Serum↗
PubMed1989

[Ultrasound attenuation as a function of frequency in formalin fixed testicular tissue].

Measurements of the ultrasound attenuation were carried out in 10 normal testes and 20 pathologically changed testicular tissue biopsies in vitro after formalin fixation. The ultrasound attenuation as function of the frequency was recorded ultrasound-spectroscopically about the complete frequency spectrum of the ultrasound-broad range transformer (3-8 MHz). The frequency dependence of the attenuation behaviour differed in the 10 normal testes from the 20 pathologically changed biopsies by smaller values of the ultrasound attenuation coefficient a (linear regression analysis). The ultrasound attenuation in a characteristic measuring point allows the differentiation between normal and pathologically changed testicular tissue. The following comparison with the histologic evidences showed the correspondence of the results.

Adolescent↗
PubMed1988

[Report of experiences on the use of cyclosporin A].

In September 1985 in our kidney transplantation centre for the first time ciclosporin A was used. Up to now altogether 50 patients received this new form of immunosuppression. During the sand immune application no essential side effects occurred. The success of the change of the therapy was independent of the degree of the serum creatinine level at the time of conversion. In the period of observation we performed altogether 106 kidney transplantations. With 88% of grafts functioning normally at the discharge under application of ciclosporin A we achieved a clear improvement of the results of transplantation in comparison with the classical immunosuppression (53.6%) in the period of observation.

Azathioprine↗
PubMed1987

[Effect of Iloprost (ZK 36 374) on hemodynamic parameters during kidney donor conditioning in animal experiments].

Hemodynamic parameters during the conditioning of kidney donors were tested under the influence of Iloprost (ZK 36 374), a stable prostacyclin derivate, in 12 house swine of a body weight of 20-50 kg. The electromagnetically measured blood flow in the right renal artery increased on an average of 73.2% after intraaortic infusion of Iloprost (1 micrograms/kg.min) during 15 minutes. The mean arterial blood pressure decreased simultaneously by 14.7%. The renal flow resistance (RVR), by blood pressure and blood flow calculated, decreased by 49.7% in average. Iloprost appears well-suitable for conditioning donors, it shows advantages in contrast to the hitherto used drugs.

Animals↗