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Biomedical subjects

K Gerlach

Publications and source records attributed to K Gerlach.

At least 37 records · Page 2Linked to original sources

Demonstration of HPV 24 in long-standing Heck's disease with malignant transformation.

We report on the rare case of a 64-year-old European woman with a viral acanthoma of the oral mucosa of the clinical Heck type with unprecedented molecular-biological proof of HPV 24 DNA and so far undescribed malignant transformation with a long existence of the vegetation. After surgical therapy a circumscribed relapse of viral acanthoma developed, which responded favourably to a combined antiviral and antiproliferative therapy with acitretin perorally and interferon, first subcutaneously, later intralesionally for 3 months.

Biopsy, Needle↗

The implementation of a quality-net as a part of the European project DIABCARE Q-Net.

DIABCARE Q-Net is a European project with a consortium of partners in healthcare, industry, and research, which has the overall target of improvement in diabetes care by aggregation, evaluation, and feedback of anonymized patient data with the tools of modern telematics, resulting from the initiative of the St. Vincent-Declaration, St. Vincent, Italy. Based on standardized tools for quality improvement in diabetes care, i.e., the Basic Information Sheet (BIS) and recently developed data entry and feedback software (DIABCARE Data for Windows), DIABCARE Q-Net as a part of the Telematics Applications Program of the European Commission will improve diabetes care and disease management by the implementation of a quality network. Therefore, the project implements regional, national, and central nodes for processing of diabetes quality indicators. All participating centers (GP's and clinics in Europe) get feedback by standardized benchmarking. The pilot testing and the state of implementation of our network confirm the importance of improving the quality of life of diabetic patients in all participating countries.

Computer Communication Networks↗

RP1, a new member of the adenomatous polyposis coli-binding EB1-like gene family, is differentially expressed in activated T cells.

Cross-linking of the CD3 and CD28 molecules on T lymphocytes represents one of the most effective signals for T lymphocyte activation and triggering of their cytotoxic effector function. To identify genes that are expressed in T cells after stimulation, mRNA from T lymphocytes that had been activated by the simultaneous stimulation of the CD3 and CD28 trigger molecules was transcribed for a differential mRNA display analysis into cDNA and was compared with cDNA from CD28- or CD3-activated or resting lymphocytes. Differential expression was confirmed subsequently by Northern blot analysis. One of the cDNA fragments expressed specifically in CD3- and CD28-activated T cells was designated RP1. The predictive protein-coding region of RP1 had a significant homology to members of the recently found adenomatous polyposis coli (APC) protein-binding EB1 gene family, which codes for yet unknown protein(s). Bacterially expressed RP1 protein revealed specific binding to wild-type but not to mutated APC protein. The rapid up-regulation of RP1 mRNA in properly activated T cells suggests that this gene might belong to the immediate/early gene family, which controls the signal transduction cascade downstream of the TCR. As the expression level of the RP1 gene in activated T cells and a spectrum of tumor-derived cell lines correlates with the proliferative status of the cells, members of the EB1-like gene family may not only be involved in the tumorigenesis of colorectal cancers but may also play a role in the proliferative control of normal cells.

Adenomatous Polyposis Coli↗

Role of perforin, granzymes and the proliferative state of the target cells in apoptosis and necrosis mediated by bispecific-antibody-activated cytotoxic T cells.

Bispecific monoclonal antibodies (bi-mAb), directed against a tumor-associated antigen and the CD3 or CD28 antigen on T lymphocytes, induce activation of resting T lymphocytes and target-specific tumor cell lysis. We now show that both necrosis and apoptosis contribute to T-cell-mediated tumor cell destruction. Even though T cells up-regulate FAS/APO-1 expression upon bi-mAb stimulation, FAS/APO-1-mediated apoptosis does not contribute to bi-mAb-mediated destruction of Hodgkin's cells. CD8+ lymphocytes were the most potent effectors of bi-mAb-mediated cytotoxicity and had the highest levels of mRNA coding for perforin and granzyme A and B. Ca2+-complexing agents, which abrogate perforin activity, led to decreased levels of necrosis, while inhibition of granzyme activity in effector or target cells had a similar effect on apoptosis. Granzyme-mediated apoptosis critically dependent on the proliferative state of the target cells, while perforin-induced necrosis was not cell-cycle-dependent. Our results underline the importance of the expression levels of perforin and granzymes in the effector T cells and of the proliferative state of the target cells in bi-mAb-mediated apoptosis and necrosis of tumor cells.

Antibodies, Bispecific↗

Role of naive and memory T cells in tumor cell lysis mediated by bi-specific antibodies.

Bispecific monoclonal antibodies (Bi-mAb) with specificity for a tumor associated antigen and the CD3 or CD28 antigen on T lymphocytes, respectively, induce activation of resting T lymphocytes and target-specific tumor cell lysis. Former studies had confirmed that T cells expressing the CD45RO "memory" antigen at high levels were the most potent effectors of Bi-mAb-mediated cytotoxicity when compared to their "naive" counterparts expressing the CD45RA antigen. Further analysis of the T cell subpopulations revealed that within the memory T cell pool, CD8+ T cells were the effector cell, population with strongest cytolytic activity. The cytolytic activity was correlated with the expression level of perforin and granzymes B mRNA. Ca2+ complexing agents, which abrogate perforin activity, reduced necrosis, while inhibition of granzyme activity in effector or target-cells had a similar effect on apoptosis. These results confirm the crucial role perforin and granzymes play in target-cell lysis and explain why CD8+CD45RO+ T cells activated by combined CD3 and CD28 antigen triggering represent the T cell pool with highest cytolytic potential.

Antibodies, Bispecific↗

[Effect of endoscopic surgery techniques in children on ventilation].

The purpose of our study was to show the effects of laparoscopic procedures on the ventilation of children. We measured an increase of ventilation pressures (Pmax, Ppfat and Pmean) of 28, 35 and 48% respectively. petCO2 rose from 35 to 41 +/- 2 mmHg. There was no loss of body temperature in any child. Laparoscopic procedures as seen here for appendectomy or diagnostic exploration in children of 13.5 kg body weight or more caused no problems that were clinically evident. The increase of ventilation pressure could be attenuated by choosing the parameters of ventilation (e.g. flow, I:E ratio) in such a way that Pmax does not exceed 20 mbar. Alternatively, pressure-controlled ventilation may be used, adjusting petCO2 by ventilation frequency. In any case there must be a strict control of all possible side effects of laparoscopy, such as cutaneous emphysema or pneumothorax.

Anesthesia, General↗

[Invasive pressure measuring for the determination of the aortic opening surface in normal and stenotic left ventricular outflow tracts].

A method of evaluation of the aortic opening area in healthy dogs and dogs with aortic stenosis is described. Through right and left heart catheterisation intraventricular and intravascular pressures were measured. For the determination of cardiac output the thermodilution technique is used. The aortic opening area is calculated by using the GORLIN-formula. Values of normal and stenotic left ventricular outflow opening area are given.

Animals↗

[Changes in the heart beat of puppies in the first twelve weeks of life].

In 37 healthy pups and seven pups with congenital pulmonic stenosis ECG were recorded and the heart rate determined. Between the first week of life in healthy pups (mean = 230/min) and the twelfth week of life the heart rate in both groups at six weeks was 195/min and 180/min. At the end of the investigation the averaged heart rate was 167/min or 166/min respectively. In single weeks during the investigation a slightly increased heart rate occurred in a few dogs between the fourth and sixth week of life owing to an increased restlessness during this time span. The heart rate of newborn pups at the first day (mean = 215/min) was a little lower than the average in the first week of life.

Aging↗

Biostability of polyurethanes.

Aside from the medical requirements a material has to fulfill to qualify as biocompatible, for the bioengineer, who is involved in the design, construction and fabrication of prosthetic devices, the mechanical, physical and chemical properties of the material as well as its possible manufacturing procedures and, last but not least, its biostability are of the same importance. In the very aggressive biological environment, the material should behave inertly, showing no surface erosions, molecular chain disruptions, uptake of low molecular weight biological materials, local chemical imbalances, tendency to calcification or negative changes of mechanical properties. With regard to this aspect, different polyurethanes have been evaluated in-vitro and in-vivo as basic materials and already fabricated devices (blood pumps and heart valves). The comparison of the results stresses the necessity of further efforts to achieve a standardized test protocol for the prove of the biostability of polymers, containing appropriate, well-defined in-vitro and in-vivo test methods to establish the necessary data basa for the materials' clinical approval.

Animals↗

[Localization of the freezing front in tissue by the ultrasound-A picture technic in cryotherapy].

The knowledge of the depth of infiltration of the freezing front in the treated tissue represented an essential demand for an optimal cryotherapy (sprayfreezing and contactfreezing). The hitherto used invasive measuring methods are connected with a tissue traumatisation and therefore only applicable in a limited way. On that account the non-invasive ultrasound-A-picture-technique was applied for defining the freezing front extension. Its qualification was represented in vitro (gelatin), in living biological tissue (muscle of rabbit), and on the human eye (cryotherapy of the primary glaucoma). The use of the sonography in the cryotherapy can be recommended for other special medical branches too.

Animals↗