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Biomedical subjects

W Bergler

Publications and source records attributed to W Bergler.

60 records · Page 4Linked to original sources
PubMedDate not supplied

Effect of organophosphorus compound intoxication on auditory brainstem response in mini pigs.

Organophosphorus compounds (OPC) are widely used as insecticides and cause a high number of acute and chronic intoxications in man. Their toxicological properties lead among others to disturbances of the central nervous system. Hearing disturbances have been reported after chronic exposure to OPC, and changes in bioelectric brain activity have been observed during the acute state of intoxication. The EEG showed no characteristic alterations. We performed a threshold auditory brainstem response (ABR) in 12 mini pigs before, during and after paraoxon (a typical OPC) intoxication with a high dose of 27 mg/kg BW. During the application of paraoxon we saw a prolongation of the interpeak latencies Jewett I-V of approximately 1 ms. A threshold shift of 10-20 dB was seen in 8 animals. After the application, while the systemic effect of the paraoxon intoxication was still apparent, the threshold shift disappeared except for 2 animals and the prolongation of the interpeak latencies could not be observed any more. No characteristic signs of paraoxon intoxication could be seen in the ABR after the application was completed. Acute intoxication with an OPC only leads to temporary, limited hearing impairment and increased interpeak latency. We could not observe characteristic changes in the ABR corresponding to the state of intoxication.

Acute Disease↗
PubMedDate not supplied

Establishment and characterization of cisplatin-resistant sublines of the human squamous carcinoma cell line HLac 79.

Though various chemotherapy protocols lead to considerable response rates in squamous cell head and neck cancer (SCHNC), the overgrowth of a tumor cell phenotype which no longer responds to clinically achievable drug concentrations regularly impairs definite tumor control. In order to investigate mechanisms of drug resistance towards one of the most active agents in SCHNC we established four Cisplatin (CDDP)-resistant sublines (DDP1-DDP4) of the recloned human SCHNC cell line HLac 79. The 50% inhibitory drug concentration (IC50) of CDDP as determined by the colorimetric MTT-assay was increased by the factors 2.7 (DDP1), 3.3 (DDP2), 5.1 (DDP3), and 6.4 (DDP4) in the respective sublines. Three subpopulations contained significantly elevated glutathione (GSH) levels by the factors 1.4 (DDP3), 1.7 (DDP2), and 2.4 (DDP4) compared to the maternal line (50.2 nM/mg protein). DDP4 showed increased activity of gamma-glutamyl-transpeptidase (1.83 vs. 1.21 mU/mg protein), and DDP2 and DDP4 showed increased activity of GSH-S-transferase (35.6 and 51.9 vs. 25.1 mU/mg protein). Concerning both GSH-peroxidase and GSH-reductase no significant differences between the HLac 79 subpopulations were observed. Intracellular CDDP accumulation determined by neutron activation analysis revealed reduced drug uptake in DDP3 and DDP4 (60% and 76% of control value).

Carcinoma, Squamous Cell↗
PubMedDate not supplied

Sonomatic confirmation of tracheal intubation using the SCOTI.

This study compares the performance of two commercially available devices (Ambu TubeChek and SCOTI) in establishing endotracheal (ET) tube position (oesophageal vs. tracheal) in a mannequin and in miniature pigs. The Ambu TubeChek is a syringe-type, Oesophageal Detector Device (ODD) that fits to the endotracheal tube connector. Air is aspirated easily from the rigid trachea, but not from the collapsing esophagus. The Sonomatic Confirmation of Tracheal Intubation device (SCOTI) is a lightweight battery-powered, sonomatic device. It emits sound waves into the tube and analyzes the reflection. The SCOTI purports to enable a user-independent and carbon-dioxide-independent assessment of tube position following intubation. Intubation followed by tube position assessment with Ambu TubeChek (ODD) was significantly faster and easier with the ODD than with the SCOTI. The SCOTI cannot differentiate tracheal from oesophageal ET-tube position in mini-pigs. In situations in which capnometry is not available or the CO2 production and transport are compromised (CPR), we recommend the use of an Oesophageal Detector Device (ODD) rather than the SOCTI.

Animals↗
PubMedDate not supplied

Inverse correlation of apoptotic and angiogenic markers in squamous cell carcinoma of the head and neck.

Angiogenesis is essential for tumour growth and metastasis. The induction of tumour vascularization is mediated by the release of angiogenic peptides. Among these factors, basic fibroblast growth factor (bFGF), vascular endothelial growth factor (VEGF) and matrix metalloproteinase-9 (MMP-9) are thought to be the most important. Previous experimental studies indicate that the process of apoptosis, the programme of cell death, may be related to angiogenesis in head and neck carcinogenesis. Therefore, cryostat sections of 49 head and neck squamous cell carcinomas (HNSCC) were investigated immunohistochemically for pro-apoptotic factors caspase-3 and Fas ligand (FasL) using a standard streptavidin-biotin complex procedure. Expression of bFGF, VEGF and MMP-9 served as angiogenic markers. Additionally, intratumoral microvascular density (MVD) was counted by immunostaining of endothelial cells using anti-vWF antibody. Comparing the expression of apoptotic and angiogenic factors, a statistically significant inverse correlation of caspase-3 expression and VEGF and MMP-9 expression was found. Concerning FasL, the correlation of its expression with expression of VEGF, bFGF and MMP-9 was inversely correlated. With respect to vWF-immunostaining, statistical analysis gave a clear inverse correlation between the tumour vascularity and the expression of FasL (p = 0.0008) and caspase-3 (p = 0.0068). Our results suggest that HNSCC tumour angiogenesis contributes to a reduction of apoptosis in tumour cells. This may be explained by the activation of pro-apoptotic factors caused by hypoxia.

Adult↗
PubMedDate not supplied

[Diminution of epidermal growth factor in saliva of patients with carcinoma of the oropharynx].

EGF, the Epidermal Growth Factor which is found ubiquitous in the human body can also be detected in saliva and increases in general proliferation and differentiation of epithelial cells which enables mucosa regeneration to maintain their protective function. In this study concentrations of EGF in saliva of smokers and patients with carcinoma of the oropharynx were examined. Both groups showed a decreased concentration compared to non smokers. We studied also secretion of EGF in saliva after smoking. Only the group of non smokers showed a transient elevation of EGF.

Epidermal Growth Factor↗