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Biomedical subjects

A Dietz

Publications and source records attributed to A Dietz.

At least 109 records · Page 6Linked to original sources
PubMed1995

Indoor air pollution by emissions of fossil fuel single stoves: possibly a hitherto underrated risk factor in the development of carcinomas in the head and neck.

We have carried out three case-control studies on the relative risk of head and neck cancer in association with indoor air pollution. The studies performed at the Department of Otorhinolaryngology of the University of Heidelberg comprised 369 male patients with squamous cell carcinoma of the oral cavity, pharynx, and larynx and 1476 healthy control subjects matched for sex, age, and residential area. The OR of laryngeal cancer related to daily exposure to fossil fuels due to stove-heating with oil, coal, gas, and wood for longer than 40 years was 2.5 (CI = 1.51 to 4.05). After adjustment for tobacco and alcohol, the OR declined slightly to 2.0 (CI = 1.10 to 3.46) but still was significant. Elevated ORs were also found for daily presence in a kitchen with an oil, coal, or wood oven for longer than 40 years (OR = 1.7, CI = 1.01 to 2.71; after tobacco and alcohol adjustment, OR = 1.4, CI = 0.76 to 2.41). The OR of pharyngeal cancer related to daily exposure to fossil fuels due to stove-heating with oil, coal, gas, and wood for longer than 40 years was 3.6 (CI = 2.04 to 6.41). After adjustment for tobacco and alcohol the OR declined slightly to 3.3 (CI = 1.43 to 7.55) but still was significant. Elevated ORs were also found for daily presence in a kitchen with an oil, coal, or wood oven for longer than 40 years (OR = 1.6, CI = 0.89 to 2.77; after tobacco and alcohol adjustment, OR = 2.5, CI = 1.03 to 6.30).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1995

[The problem of radiogenic and chemotherapy-induced mucositis of the mouth and and oropharynx exemplified by accelerated radiochemotherapy with carboplatin in patients with inoperable squamous epithelial carcinomas of the head-/neck area. Heidelberg experiences].

Despite numerous treatment measures mucositis of the mouth and pharynx due to radiochemotherapy frequently remains refractory to therapy. In most cases high doses of pain medications are till required. However, mucositis as a strong early reaction may be controllable by limiting cancer therapy. Within the current framework of accelerated radiochemotherapy with carboplatin, 50 patients with inoperable squamous cell carcinomas of the head and neck were followed from 1992 to 1994. Acute toxicity was documented from the first through eighth week after starting therapy. From the fifth week on, the degree of mucositis found was > 3 (WHO scale) in 24 patients. The extent of mucositis in 5 patients required interrupting therapy for 10 days on average. In 14 cases the average stay in hospital had to be prolonged by 10.2 days because of severe inflammation. In all, the average duration of mucositis after the end of the therapy amounted to 9.6 weeks. Twenty patients required bypass feedings with transnasal stomach tubes or percutaneous gastrostomy (PEG) tubes that were later removed. In addition, the incidences of dysphagia, xerostomia, hoarseness, skin reactions, nausea or vomitus and myelotoxicity were recorded. Descriptions of the supportive care concepts used at the University of Heidelberg are given and the supportive care concepts available scientific literature is updated.

Adult↗
PubMed1995

[Precancerous condition of the mouth mucosa: lichen ruber planus].

We report the case history of a 60-year-old male caucasian with lichen ruber planus of the oral cavity. After having this condition for 5 years, a medium-grade differentiated squamous cell carcinoma developed on the same side. Since a history of tobacco and alcohol abuse was negative, the Lichen ruber planus was considered to be a precancerous lesion without any other concomitant condition.

Carcinoma, Squamous Cell↗
PubMed1994

A plant scaffold attached region detected close to a T-DNA integration site is active in mammalian cells.

Integration of foreign genes into plant genomes by the Agrobacterium T-DNA transfer system has been considered to occur at random. It has been speculated that the chromosomal structure of the integration site might affect the expression pattern of the introduced genes. To gain insight into the molecular structure of T-DNA integration sites and its possible impact on gene expression, we have examined plant DNA sequences in the vicinity of T-DNA borders. Analysis of a transgenic petunia plant containing a chloramphenicol acetyltransferase (CAT) gene regulated by the hemoglobin promoter (PAR) from Parasponia andersonii revealed a scaffold attachment region (SAR) close to one T-DNA end. In addition to having strong binding affinities for both animal and plant nuclear scaffolds this petunia SAR element is as active in mammalian cells as the authentic elements from mammalian sources.

Agrobacterium tumefaciens↗
PubMed1994

[Indoor air pollution by emissions from individual fossil fuel stoves. Possibly a so-far underestimated risk factor in development of cancers of the head and neck area].

We have carried out three case-control studies on the relative risk of head and neck cancer in association with indoor air pollution. The studies performed at the Department of Otorhinolaryngology of the University of Heidelberg comprised 369 male patients with squamous cell carcinomas of the oral cavity, pharynx and larynx; one thousand, four hundred and seventy-six healthy subjects were used as controls and were matched for sex, age and residential area. The relative risk (RR) of laryngeal cancer related to daily exposure to fossil fuels due to stove heating with oil, coal, gas and wood in a period longer than 40 years was 2.5 [confidence interval (CI): 1.51-4.05]. After adjustment for tobacco and alcohol the RR declined slightly to 2.0 [CI: 1.10-3.46] but was still significant. Increased risks were also found for daily exposure in a kitchen containing air oil, coal or wood oven for a period longer than 40 years (RR = 1.7; CI: 1.01-2.71). In this latter group the RR because 1.4 after adjustments for use of tobacco and alcohol [CI: 0.76-2.41]). The RR of pharyngeal cancer related to daily exposure to fossil fuels due to stove heating with oil, coal, gas and wood in a period longer than 40 years was 3.6 [CI: 2.04-6.41]. After adjustments were made for tobacco and alcohol, the RR declined slightly to 3.3 [CI: 1.43-7.55] but was still significant. Elevated risks were also found for daily presence in a kitchen with oil, coal or wood ovens for a period longer than 40 years (RR = 1.6 [CI: 0.89-2.77].(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

Chronic lymphocytic leukemia cells induce non-T cells to produce IgE in the presence of interleukin-4.

Mononuclear cells from peripheral blood and bone marrow from patients with chronic lymphocytic leukemia (CLL) were cultured with interleukin-4 (IL-4) alone or with IL-4 and hydrocortisone (HC) in order to induce IgE synthesis. From a total of 29 experiments with the cells of 17 different donors an IgE secretion was observed only twice. Even in those two cases the IgE was found to be not monoclonal. The additional stimulation of CLL cells by polyclonal B cell activators induced IgM but not IgE production. When CLL cells were cocultured with monocyte-enriched cell preparations (M phi) in the presence of IL-4 and HC, a substantial IgE secretion could be obtained, which again consisted of both IgE kappa and IgE lambda. Since the irradiation of the M phi but not of the CLL cells abolished the formation of IgE, it is likely that the IgE production resided in the contaminating B cell population of the M phi. When the M phi were replaced by T cell-depleted peripheral blood mononuclear cells (non-T cells), irradiated as well as formaldehyde fixed CLL cells were able to stimulate non-T cells to secrete IgE in the presence of IL-4 or to potentiate IL-4- and HC-induced IgE formation. Furthermore, the coculture of irradiated pure CLL cells and purified B cells induced not only IgE but also IgG and IgM production and B cell proliferation in the presence of lymphokines. Our findings suggest that CLL cells, contrary to current opinion, cannot be induced to produce IgE.(ABSTRACT TRUNCATED AT 250 WORDS)

B-Lymphocytes↗
PubMed1993

[Balloon occlusion test of the internal carotid artery for evaluating resectability of blood vessel infiltrating cervical metastasis of advanced head and neck cancers--Heidelberg experience].

During the last two years 17 patients of the ENT-Department of the University of Heidelberg suffering from squamous-cell carcinomas of the head and neck underwent a balloon occlusion test of the internal carotid artery (ICA). The investigation was performed because of tumorous infiltration of the large cervical vessels. The balloon occlusion of the ICA was accomplished at the Department of Neuroradiology of the University of Heidelberg. While stopping bloodflow in the ICA of one side for 15-20 min, clinical, electrophysiological and Doppler sonographic monitoring was performed, to detect severe cerebral complications. The specific electrophysiological monitoring contained the detection of MSSEP's (median nerve stimulated somatosensorial evoked potentials) and TCMEP's (transcortical motor evoked potentials) during test occlusion. Balloon occlusion was not possible in three patients because of severe arteriosclerosis. Test occlusion had to be discontinued in three patients because of clinical complications (temporary amaurosis, orthostatic complications). Finally, seven patients showed contraindications during test occlusion for permanent occlusion of the ICA. Four patients had a permanent occlusion of the ICA after tumour resection. In two patients the ICA was removed without problems in test occlusion. The third patient underwent a permanent carotid occlusion because of bleeding complications (in spite of poor clinical tolerance of the test occlusion). In the fourth patient, only intraoperative neuromonitoring with MSSEP's was conducted before permanent carotid occlusion. All four patients did not show any neurological deficits after resection of the ICA. Neurophysiological monitoring played an important role in predicting cerebral complications after permanent occlusion of the ICA.

Adult↗
PubMed1993

[The epidemiology of parotid tumors. A case control study].

From 1989 to 1991 a case-control study was conducted at the ENT Department of the University of Heidelberg. One hundred and one patients with parotid tumors (84 benign and 17 malignant) were compared with 404 control patients in a matched-pair study design. Using a questionnaire containing 21 sides, all interviews were conducted by the same interviewer. The questionnaire contained such aspects as "professional surroundings and exposure to environmental dusts", "consumption of tobacco and alcohol", "living area", "nutrition", "hobbies" and "social life". Questions about personal and familial diseases, consumption of medicine and exposure to irradiation were also asked. Differences in exposure to occupational dusts were seen. The highest relative risk (RR) for developing a parotid tumor was seen with weekly exposure to nickel during a period of more than 10 years (RR = 6.0; confidence interval, 1.4-25.5). Similar risk was found with exposure to chromium, asbestos and cement dusts (RR chromium = 3.4; confidence interval, 0.9-14.5; RR asbestos + cement = cement 3.0, confidence interval 1.0-8.9). Higher relative risks were also detected in patients exposed to diagnostic dental x-rays.

Adult↗
PubMed1992

The role of T cells and the effect of hydrocortisone on interleukin-4-induced IgE synthesis by non-T cells.

The role of T cells for IL-4-induced IgE synthesis by peripheral blood mononuclear cells (PBMC) was investigated. The removal of monocytes from PBMC abolished IL-4-induced IgE synthesis. When PBMC were separated into T and non-T cells, non-T cells alone were not able to secrete significant amounts of IgE in the presence of IL-4. Depending on the separation procedure, the reconstitution of non-T cells with T cells prepared by rosetting did not restore IgE secretion, whereas T cells obtained by the use of anti-CD3 antibodies could co-induce IgE formation. However, when the T cells were first irradiated, large amounts of IgE were produced, which strongly exceeded those found in unseparated PBMC cultures. IL-4-induced IgE synthesis was also obtained in co-cultures of formaldehyde-fixed T cells with non-T cells. Furthermore, not only autologous but also allogeneic T cells, which have been irradiated or fixed, could provide the costimulatory effect on IgE formation by non-T cells in the presence of IL-4. Mitogenically pre-activated T cells, however, were not able to support IgE synthesis. Hydrocortisone (HC) potentiated the IL-4-induced IgE synthesis by PBMC and enabled non-T cells to secrete IgE in the presence of IL-4. Adding both HC and T cells led to a marked synergistic effect on IL-4-induced IgE production. We conclude that monocytes are required for the induction of IgE synthesis in PBMC in addition to T cells and IL-4. Our results support the view that the T cell signal is delivered via cognate and non-cognate T/B cell membrane interaction. Furthermore, active and proliferating T cells rather suppress IgE synthesis. Finally, HC appears to be a potent alternative stimulus, which bypasses the necessity for T cells in IL-4-induced IgE formation.

B-Lymphocytes↗
PubMed1992

Risk factors of cancer of the larynx: results of the Heidelberg case-control study.

Squamous cell carcinoma of the larynx is a multifactorial disease. It is firmly linked to several environmental risk factors. In the meanwhile, a considerable amount of epidemiologic evidence has been built up to implicate chronic consumption of alcohol and tobacco, occupation, diet, and social status in the etiology of the laryngeal cancer. Herein is a report from the first case-control study on the role of these risk factors conducted in a German population of patients with laryngeal cancer.

Adult↗
PubMed1992

[Laryngeal cancer and occupation--results of the Heidelberg laryngeal cancer study].

We conducted a case-control study of squamous cell carcinoma of the larynx referred to occupational factors in 164 patients compared with 656 controls adjusted for sex, age and area of residence, using a 1-to-4 matched design. Most of the cancer patients (92%) were blue collar workers. Only 8% of the cancer patients had attended technical college, college or university, compared with 31.3% of the control subjects. After adjustment for alcohol and tobacco consumption we found an increased relative risk of laryngeal cancer in subjects chronically exposed to cement dust, pine wood dust and coal-tar products. The risk associated with cement dust and coal-tar products was predominantly related to supraglottic cancer (RR = 1.88, CI = 0.8-4.3, RR = 6.11, CI = 1.7-21.6), respectively, after adjustment for tobacco and alcohol use. The risk associated with pine wood dust was related predominantly to glottic cancer (RR = 3.18, CI = 1.1-9.0) after adjustment for tobacco and alcohol use.

Carcinoma, Squamous Cell↗
PubMed1991

[Occupational exposure to hazardous substances and risk of cancer in the area of the mouth cavity, oropharynx, hypopharynx and larynx. A case-control study].

A case-control study of squamous cell carcinoma of the upper aerodigestive tract conducted in Heidelberg and Giessen (FRG) provided information on occupational factors in 200 patients and 800 controls (adjusted to sex, age and area of living; 4:1 matched design). The number of subjects exposed to wood dusts, organic chemicals, coal products or to cement was significantly elevated in the tumour group. An increased risk for head and neck cancer was observed after exposition to wood dust (RR = 2,2), organic compounds (RR = 2,4), coal products (RR = 2,7) and especially to cement (RR = 4,4). The cancer risk due to cement exposition showed a positive correlation to the duration of exposition and remained significantly elevated after adjustment for alcohol and tobacco consumption.

Adult↗
PubMed1991

[Epidemiologic aspects of cancers of the head-neck area].

This review gives an impression of the different epidemiological aspects of squamous cell carcinomas of the oral cavity, the pharynx and the larynx. The main riskfactor associated to development of head/neck-cancer is the chronical consumption of tobacco and alcohol. Tobacco contains different types of well known carcinogens (tobaccospecific nitrosamins, polycyclic aromatic carbonates PAH). Alcohol by itself is not described as carcinogen. The multiplicative effect on the carcinogenic potency of tobacco in head/neck-cancer caused by alcohol consumption is well documented in many epidemiological studies. Enquires were directed at occupational exposure to substances like asbestos, solvents, coal products, welding fumes, wood dust, cement and many other substances. Different authors could show that socioeconomic factors, dietary habits and life style are associated to an elevated head/neck-cancer risk, independent of alcohol and tobacco consumption.

Carcinogens↗
PubMed1990

[Risk factors for squamous epithelial carcinoma of the mouth, the oropharynx, the hypopharynx and the larynx].

This case-control-study, carried out in two University clinics, comprised 200 men (mean age 57.5 +/- 10.8 [range 33-89] years) with squamous epithelioma of the larynx (44.5%), oral cavity (23.5%), oropharynx (24%) or hypopharynx (8%) and 800 controls. Enquiries were directed at social status, life style and occupational exposure to substances such as asbestos, solvents, wood dust and cement. The peak incidence of these cancers was from 50 to 60 years of age. The proportion of unmarried or divorced men among the cancer patients was more than twice as high as in the controls (25.8% vs 11.8%; P less than 0.001). The proportion of cancer patients who had completed technical college or university education was significantly lower than in the controls (9.6% vs 24.4%; P less than 0.001). Tobacco and alcohol consumption by the cancer patients was roughly twice as great as in the controls: the cancer patients admitted to an average cigarette consumption of 43.2 +/- 27.9 pack years as compared with 20.1 +/- 26.7 pack years for the controls (P less than 0.001), and an alcohol intake of 69.2 +/- 58.1 g/d as compared with 29.8 +/- 27.5 g/d for the controls (P less than 0.001). Both these factors--drinking alcohol and smoking cigarettes--acted independently of one another to raise the relative risk of squamous epithelioma of the upper respiratory or digestive tract. The effects of alcohol and tobacco on cancer risk were multiplicative rather than merely additive. Enquiries into diet failed to reveal any clear differences tending to incriminate any particular food. Long-term exposure to cement dust was linked with an increased risk of cancer.

Adult↗
PubMed1990

The gene for Klebsiella bacteriophage K11 RNA polymerase: sequence and comparison with the homologous genes of phages T7, T3, and SP6.

We determined the nucleotide sequence of gene 1 of Klebsiella phage K11, which is a member of the T7 group of phages. The largest open reading frame corresponds to a polypeptide with 906 amino acids and a molecular weight of 100,383 daltons. The deduced amino acid sequence of this polypeptide shows 71% homology to the T7 RNA polymerase (the product of T7 gene 1), 72% homology to the T3 RNA polymerase and 27% homology to the SP6 RNA polymerase. Divergent evolution was clearly most pronounced in the amino-terminal portion.

Amino Acid Sequence↗