Biomedical subjects

A Herrmann

Publications and source records attributed to A Herrmann.

206 records · Page 12Linked to original sources

PubMedDate not supplied

Long-term risk of gastrointestinal tumor recurrence after postoperative treatment with recombinant human growth hormone.

BACKGROUND: Recombinant human growth hormone (rhGH) promotes protein synthesis, accelerates wound healing, and maintains immune function in the catabolic state. It has also been claimed that rhGH may promote the activation of residual tumor cells, and therefore, increases the risk of tumor recurrence. This study aimed to investigate whether postoperative administration of rhGH increases the long-term risk of tumor recurrences in patients undergoing major gastrointestinal surgery for malignancy. METHODS: Patients (n =104) received three different doses of rhGH (0.075 IU/kg, 0.150 IU/kg, and 0.300 IU/kg) during 5 postoperative days in a placebo-controlled trial. Follow-up was performed for 56-70 months after radical tumor resection. Mean survival period and relapse-free survival were compared with the control group. RESULTS: Complete data were available for 75 patients. Thirty-five percent (n = 20) of all patients treated with rhGH showed tumor recurrences in comparison to 44% (n = 8) of patients given placebo. Mean survival period for rhGH-treated patients was 46 months (median 59 months); in controls, 42 months (median 58 months). The length of relapse-free survival tended to be longer in rhGH-treated patients (2-47 months; median, 21 months) compared with the patients who were given placebo (2-18 months; median, 13 months). CONCLUSIONS: The results demonstrate no evidence for an increased risk of tumor recurrence after rhGH treatment for a short period of time after removal of a gastrointestinal adenocarcinoma. Therefore, the positive metabolic effects of rhGH application can be used safely in the treatment of the postoperative catabolic state in the patient groups investigated.

Adenocarcinoma↗

PubMedDate not supplied

Role of target membrane structure in fusion with influenza virus: effect of modulating erythrocyte transbilayer phospholipid distribution.

To study the role of the target membrane in influenza virus fusion we chose erythrocyte membranes whose phospholipid arrangement can readily be modified. The phospholipids of normal erythrocytes are arranged asymmetrically across the plasma membrane; phosphatidylcholine (PC) and sphingomyelin are predominantly on the outer surface, whereas others such as phosphatidylserine (PS) and phosphatidylethanolamine (PE) are predominantly restricted to the inner leaflet. However, erythrocytes can be lyzed and resealed under conditions where the asymmetric distribution of phospholipids is lost or retained. Low pH-induced fusion of the A/PR 8 strain of influenza virus, monitored spectrofluorometrically by the octadecylrhodamine dequenching assay, was more rapid with lipid-symmetric erythrocyte ghosts than with lipid-asymmetric ghosts or intact erythrocytes. Neither conversion of PS in the lipid-symmetric ghost membrane to PE by means of the enzyme PS decarboxylaze, nor incorporation of spin-labeled phospholipid analogs with PS, PC or PE headgroups into the outer leaflet of lipid-asymmetric erythrocytes altered rates or extents of fusion of A/PR 8 with the modified target. These results indicate that effects on influenza virus fusion are not associated with any particular phospholipid headgroup, but rather related to the packing characteristics of the target membrane.

Calcium↗

PubMedDate not supplied

Rapid determination of the transbilayer distribution of NBD-phospholipids in erythrocyte membranes with dithionite.

The assessment of the transverse distribution and mobility of NBD-labelled phospholipid analogues in biological membranes by selective chemical destruction of fluorescent label in the outer monolayer with dithionite has been investigated using resealed erythrocyte ghosts as a model system. The distribution of those analogues can be determined in < 30 s directly in the cell suspension provided the permeation of dithionite across the membrane is suppressed. The results were compared with data on translocation of either NBD- or spin-labelled phospholipid analogues obtained with the technique of back exchange to BSA. It is shown that the passage of dithionite can be mediated by anion-transport systems such as band 3 which is inhibited by DIDS. Appropriate conditions for the applicability of the assay were elucidated also using resealed ghosts having fluorescent NBD-taurine in the intracellular lumen. The application of the assay to measure fast translocation processes, e.g. those mediated by the aminophospholipid translocase, is described.

4-Chloro-7-nitrobenzofurazan↗

PubMedDate not supplied

Influence of the spectrin network on fusion of influenza virus with red blood cells.

We examined the influence of the physical state of the membrane skeleton on low pH fusion of influenza virus A/PR 8/34 with intact human red blood cells. Spectrin, the major component of the skeleton, is known to become denaturated at 50 degrees C. After heat treatment of erythrocytes at 50 degrees C we observed an enhanced kinetics of fusion monitored spectrofluorometrically by the octadecylrhodamine fluorescence dequenching assay, while the extent of fusion was not affected. The accelerated fusion of influenza virus after preincubation of red blood cells at 50 degrees C is not mediated by alterations of the lipid phase of the target. From ESR measurements using spin-labelled phospholipids we conclude that heat-induced alterations of the spectrin network did not affect either the phospholipid asymmetry or the fluidity of the exoplasmic and the cytoplasmic leaflets of the erythrocyte membrane. Moreover, as deduced from our previous investigations, the swelling behaviour of red blood cells could not be responsible for the observed effect. Possible mechanisms for the spectrin effect include a change in the ability of the target membrane to bend locally, and a change in the rate of formation and development of the fusion pore.

Erythrocyte Membrane↗

PubMedDate not supplied

Compensating lipid fluxes generated by the aminophospholipid translocase.

By a combined kinetic and thermodynamic model on the transbilayer dynamics and asymmetric distribution of lipids in the red blood cell, compensating lipid fluxes to the exoplasmic leaflet have been analysed, counterbalancing the active transport of aminophospholipids to the cytoplasmic monolayer by the aminophospholipid translocase. The compensating fluxes are assumed to be of passive nature generated by forces of lateral mechanical stress and of lipid concentration differences between the two monolayers. These forces are shown to be caused and maintained by the operation of the aminophospholipid translocase. Simulations reveal that a reduction of the compensating fluxes upon ATP-depletion can be attributed to the inhibition of the aminophospholipid translocase. Thus, a Mg(2+)- and ATP-dependence of the outward movement of phospholipid analogues in the plasma membrane of red blood cells can be expected independent of the existence and operation of an ATP-dependent 'floppase' activity.

Adenosine Triphosphate↗

PubMedDate not supplied

[Computer-assisted cardiotocography analysis within the scope of continuous electronic labor monitoring with simultaneous use of noninvasive and invasive methods of registration].

In frame of a simultaneously study with noninvasive and invasive registration technic by application of 2 fetal monitors with following computer aided CTG-analysis at 22 patients we found in relation to the quantitative CTG-parameters DF (fetal condition), D (dip area), BI (bradycardia index) as well as BR (bradycardia residuelle) in part distinct differences for the range of distribution in spite of missing statistical significance (p less than 0.05) which point to insecurity in trigger signals for the noninvasive method. As exceptionally dangerous turned out to be false trigger signals in range of medium-term heart rate changes in attendance to auto-correlation US-DOPPLER-technic. The noninvasive registration of labour pains impressed forcibly for some time about longer CTG-phases to be unsuitable for the exactly judgment of uterine activity (Montevideo-unit). In conclusion the noninvasive method in supervision of labour should be considered more critical than earlier particular under forensic points of view.

Cardiotocography↗

PubMedDate not supplied

[Clinical features and treatment of osteogenic sarcoma of the jaws].

24 patients with osteogenic sarcomas of the jaws were entered in a retrospective study. 79.2% of the cases had local relapses or distant metastases, usually within the first 2 years following surgery. With primary surgical treatment the 5 year disease free survival rates in cases with maxillary manifestations ranged at 22.1% and with mandibular sarcomas at 18.2%. Thus, prognosis for osteogenic sarcomas of the jaws is to be assessed as being no more favorable than for sarcomas of the extremities. A review of the literature shows that aggressive pro- and postoperative chemotherapy must be postulated apart from radical tumor resection to improve the survival rates.

Adolescent↗

PubMedDate not supplied

[Autologous blood and plasma replacement in displacement osteotomies of the maxillofacial region].

The concept of autologous transfusion in displacement osteotomies in oral and maxillofacial surgery is presented. Considerately and specifically applied, autotransfusion is the safest mode of blood transfusion and may replace homologous transfusion in a planned operation involving a high amount of blood loss. Although autotransfusion requires considerably more organization and man hours, costs may be saved by avoiding the wide range of complications associated with homologous transfusions. Yet, homologous transfusion, that has its justified value particularly in emergency procedures, will never be fully replaced by autotransfusion.

Blood Transfusion, Autologous↗