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Biomedical subjects

H Maier

Publications and source records attributed to H Maier.

At least 91 records · Page 5Linked to original sources
PubMed1999

[Occupation and cancer of the head-neck area].

Head- and neck-cancer is a multifactorial disease. Besides major risk factors like alcohol and tobacco consumption, occupational factors play a significant role. At present it is estimated that in western industrial nations about 4 to 10% of all head- and neck-cancer cases are caused by occupational exposures. Combined exposures to occupational and non-occupational risk factors as well as the interaction of different occupational agents may have a synergistic effect on the cancer risk. It is very likely that the cancer risk due to occupational factors is modulated by host factors like DNA repair capacity and enzymatically controlled activation and inactivation of carcinogens.

Cause of Death↗
PubMed1999

[Effect of primary radiochemotherapy on cellular and subcellular immunologic parameters].

PURPOSE: It is well known that chemotherapy and radiotherapy in other tumor sites than head and neck cause immunomodulating effects. The purpose of this trial was to assess the influence of radiochemotherapy in head and neck on cellular and subcellular immunity. PATIENTS AND METHODS: In a phase II/III-trial fifty patients with advanced squamous cell carcinoma of the head and neck were treated by simultaneously accelerated radiochemotherapy with Carboplatin (70 mg/sqm). Total radiation dose was 66 Gy/35 days. The following immunological parameters were investigated at several time points during therapy: total lymphocytes, total T-lymphocytes, CD4+ lymphocytes, CD8+ lymphocytes, monocytes, natural killer cells, interleukin-2-receptor-positive T-cells, MHC class II-positive B-cells, monocytes and T-cells, CD4/CD8-ratio; Cytokines: II-1, soluble II-1-receptor antagonist, II-2, soluble II-2-receptor, II-3, II-4, II-6, soluble II-6-receptor, II-8, interferon-alpha, granulocytes-macrophages-colony-stimulating-factor, tumor necrosis factor-alpha, soluble intercellular adhesion molecule-1. In addition, responses to the in vitro stimulation of lymphocytes by mitogens was tested. RESULTS: During therapy lymphocyte subpopulation counts decreased significantly but reversibly. Simultaneously, the function of lymphocytes was significantly but reversibly reduced. Also, II-8-concentration decreased significantly whereas concentrations of II-6 and soluble II-1-receptor antagonist significantly increased. CONCLUSIONS: The accelerated radiochemotherapy with Carboplatin induces a severe impairment of cellular immunity, followed by compensatory cytokine reaction.

Adult↗
PubMed1999

[Immunosuppression caused by head and neck surgery].

The immunomodulating effect of primary surgical intervention was investigated in 33 patients with squamous cell carcinomas of the oral cavity, pharynx and larynx. An operation time longer than 7 h was significantly associated with a decrease in lymphocytes, CD4(+) T-lymphocytes and CD8(+) T-lymphocytes. The CD4/CD8-ratio as a marker for the down-regulation of the cellular immune response was slightly decreased but was still in the normal range. CD4-lymphocyte counts increased 7 days after operation while CD8 lymphocytes were found elevated 4 weeks after surgery. The in vitro stimulation of the lymphocytes was impaired for 1 to 4 weeks. Interleukins, interferon-gamma and tumor necrosis factor did not show any changes after surgery. Decreases of lymphocytes, especially CD4(+) and CD8(+) lymphocytes, were significantly associated with the time of operation and the volume of blood loss. Extensive trauma, age, different kinds of anesthesia and intensive care interventions were not associated with specific immunomodulating effects, although these factors might be responsible for suppressing cytokine responses.

Adult↗
PubMed1999

[Imaging nerve fiber bundle defects with laser polarimetry in glaucoma. A clinical study with the Nerve Fiber Analyzer I].

PURPOSE: To verify whether nerve fiber bundle defects (NFBD) can be detected by the polarization technique of the Nerve Fiber Analyzer I (NFA I), we compared the localization of localized visual field (VF) defects with the localization of the expected corresponding NFBD. METHODS: We examined 25 eyes of 25 glaucoma patients. All examined glaucomatous eyes had localized VF defects stage II and III. The glaucoma stage was defined by examination of the central 30 degrees VF using computer perimetry. NFBD were determined by masked examination of NFA I images by three examiners. As controls 22 eyes of 22 normals were examined. RESULTS: In 18 (72%) of 25 glaucomatous eyes the three examiners agreed in their findings. In 15 of 25 glaucomatous eyes (60%) all three examiners found a NFBD, which corresponded to a localized VF defect. In 18 of 22 healthy eyes all three examiners found no NFBD. The first examiner had no false-positive results, the second three, and the third four. CONCLUSIONS: The three examiners often disagreed in their findings of NFBD, which indicates high subjective variability. Examiner-dependent specificity and sensitivity show that detection of glaucomatous NFBD is often not possible by laser polarimetry (software version 06/93).

Adult↗
PubMed1999

An association of chronic alcohol consumption with morphological alterations of the laryngeal mucosa in rats.

Within the last decades a considerable amount of epidemologic evidence has been built up to implicate chronic alcohol consumption as a major risk factor not only for oral and pharyngeal cancer, but also for laryngeal cancer. The mechanisms that underlie alcohol-related cancers of the larynx have remained largely unclear. Since the epithelium of the glottic region normally has no direct contact with alcoholic beverages, alcohol-related alterations of glottic mucosa have been questioned. In the present study 20 male Wistar rats were fed nutritionally adequate liquid diets containing 36% of the total calories either as ethanol or isocaloric carbohydrates for 6 months. Morphometric analysis of the glottic mucosa in the ethanol-fed rats showed a significant reduction in epithelial thickness of the glottic epithelium of the anterior commissure as well as of the posterior commissure (P < 0.001). Morphometric analysis of the basal cell nuclei of the glottic epithelium did not show any statistically significant differences between ethanol-fed rats and control rats. These findings indicate that chronic ethanol consumption can cause a significant atrophy of the glottic mucosal epithelium in the rat and suggest an enhanced susceptibility toward locally acting chemical carcinogens.

Alcoholism↗
PubMed1999

Prognostic impact of total tumor volume and hemoglobin concentration on the outcome of patients with advanced head and neck cancer after concomitant boost radiochemotherapy.

PURPOSE: To identify prognostic clinical and treatment related factors for local control, distant metastasis-free survival, and survival by means of a multivariate analysis in patients with advanced squamous cell carcinoma of the head and neck after concomitant boost radiochemotherapy. PATIENTS AND METHODS: From 1992 to 1995, 68 patients with squamous cell cancer of the head and neck (93% stage IV disease) were treated with a simultaneous radiochemotherapy with Carboplatin using a concomitant boost technique. The total tumor volume (TTV) was quantitatively determined based on computed tomography scans in 56 patients. A Cox proportional hazards regression analysis was performed for each of the above endpoints and statistical significance of the Cox models was verified using the likelihood ratio test and Bonferroni correction for multiple testing. RESULTS: The survival and locoregional control rates at three years were 35 and 32%. The multivariate analysis revealed a significant association between the TTV and survival (P = 0.0008) and between the pretreatment serum hemoglobin concentration and locoregional control (P = 0.01) and survival (P = 0.05). The locoregional control was significantly associated with the N-stage (P = 0.007) and there was a good correlation between the N-stage and TTV in this study population. CONCLUSION: Our data corroborate the prognostic relevance of the tumor volume and hemoglobin concentration. In studies comparing the survival of patients with advanced cancer of the head and neck, the use of the TTV as a covariable may improve the statistical power.

Adult↗
PubMed1999

PE-11, a peptide derived from chromogranin B, in the human brain.

This study was performed to investigate the distribution of chromogranin B in the human central nervous system. We used an antiserum raised against a synthetic peptide (PE-11) present in the chromogranin B molecule. PE-11-like immunoreactivity was characterized by molecular size exclusion and reversed-phase high-performance liquid chromatography. Its localization was studied using immunocytochemistry. Only the free peptide and an N-terminally elongated peptide were detected by molecular size exclusion high-performance liquid chromatography, indicating that proteolytic processing of chromogranin B is quite extensive. PE-11-like immunoreactivity was present in differently shaped fibers, varicosities and neurons, but not in glial cells. Its density varied throughout the brain. An especially high density was observed in the bed nucleus of the stria terminalis, the central and cortical nuclei of the amygdala, the hypothalamus, the hippocampus, the raphe complex, the nucleus interpeduncularis, the nucleus of the solitary tract, and laminae I and II of the spinal cord. This study demonstrates a significant processing of chromogranin B and indicates that chromogranin B constitutes a precursor for smaller peptides which are derived by endoproteolytic processing. It provides the neuroanatomical basis to investigate the chromogranin B molecule as a widespread component of large dense-core vesicles in the human central nervous system.

Adult↗
PubMed1999

Seroindeterminate patterns and seroconversions to human T-lymphotropic virus type I positivity in blood donors from Martinique, French West Indies.

BACKGROUND: Screening for human T-lymphotropic virus type I (HTLV-I) antibodies in volunteer blood donors has been systematic in the French West Indies since 1989. Western blot-indeterminate results are commonly obtained. The significance of these indeterminate serologic patterns in HTLV-I-endemic areas is still unclear. STUDY DESIGN AND METHODS: During a 2-year period, 9759 blood donors were tested for HTLV-I antibodies. The epidemiologic features of HTLV-I-seropositive, -seroindeterminate, and -seronegative donors were compared. A lookback investigation was performed for the HTLV-I-seropositive donors, and the HTLV-I-seroindeterminate individuals were followed up. RESULTS: Thirty-nine donors (0.4%) were HTLV-I seropositive and 49 (0.5%) were seroindeterminate. The age and sex ratio characteristics of the seroindeterminate donors are divergent from those of the HTLV-I-seropositive group and are more like those of the seronegative population. However, during the study period, three cases of seroconversion after an initial seroindeterminate profile were reported. Two cases were detected through follow-up of 38 HTLV-I-seroindeterminate donors over a mean of 8 months (2-24 months). The third seroconverter belonged to the HTLV-I-seropositive group and was identified through lookback investigation. This case is atypical, with p19 reactivity for several months before HTLV-I seropositivity. CONCLUSION: These findings indicate that, although HTLV-I-seroindeterminate donors mainly are HTLV-I-noninfected, the rate of seroconversion in a repeat blood donor population from an endemic region must be taken into consideration. Moreover, the case of delayed seroconversion observed in this study suggests the difficulty of counseling seroindeterminate blood donors in endemic regions.

Adult↗
PubMed1999

[Evidence-based medicine--a critical overview].

BACKGROUND: Evidence-based medicine (EBM) is a strategy for the standardization of medical decision-making. The purpose of this review was to demonstrate the most important tools of EBM and to critically appraise them. METHODS: The current literature concerning the subject is reviewed. A clinical example for the systematic use of EBM in diagnostic tests is explained in detail. RESULTS: The risk of an increasing bureaucratic hindrance of medical procedures by EBM is weighed against the advantages of a systematic strategy for the valid assessment of medical information. According to the clinical example EBM proves to be a valuable tool in the quantitative estimation of residual risk and reliability of diagnostic tests in everyday clinical practice. CONCLUSION: The critical use of the systematic tools of EBM for clinical decision-making is recommended.

Decision Support Techniques↗
PubMed1999

Psychological predictors of mortality in old age.

Cox regression models examined associations between 17 indicators of psychological functioning (intellectual abilities, personality, subjective well-being, and social relations) and mortality. The sample (N = 516, age range 70-103 years) comprised participants in the Berlin Aging Study assessed between 1990 and 1993. By 1996, 50% had died. Eleven indicators were identified as mortality risk factors at the zero-order level and six when age was controlled. Low perceptual speed and dissatisfaction with aging were uniquely significant after controls for age, SES, health, and the 16 other psychological factors. Low intellectual functioning was a greater risk for individuals aged 70-84 years than for the oldest old (over 85 years). The effects of psychological risk factors did not diminish over time. Future research should focus on the mechanisms and time frames that underlie the death-relatedness of intellectual functioning and self-evaluation.

Aged↗
PubMed1999

[Genotoxic effect on human mucous membrane biopsies of the upper aerodigestive tract].

BACKGROUND: In numerous epidemiologic studies, environmental and occupational substances such as sodium dichromate (Na2Cr2O7), benzo[a]pyren (B(a)P), and N'nitroso-diethanolamine (NDELA) have been shown to be of potential carcinogenic risk on human epithelial cells in the upper aerodigestive tract. METHODS: Using the alkaline microgel electrophoresis technique (comet assay). mucosal cells isolated from biopsies of the upper aerodigestive tract (nose, paranasal sinuses, mouth, pharynx, larynx, and tonsils) were used to analyze target sites for different genotoxic substances and specific sensitivities of each donor. The cells were freshly isolated by enzymic digestion. 0.5-1 x 10(6) cells per donor were obtained with viabilities between 80-100%. After in vitro incubation, the cells were subsequently subjected to the single cell microgel electrophoresis assay. Results were evaluated regarding the personal history of each donor, focusing on previous exposure to tobacco, alcohol, and occupational compounds. RESULTS: Na2Cr2O7 induced strong genotoxic damage in the nasal and paranasal sinus epithelia as well as in mucosa cells of the larynx. NDELA caused significant damage in mouth cavity epithelia and showed also to be harmful towards mucosa of pharynx and larynx. B(a)P induced fewer DNA strand breaks in mucosal cells of mouth, pharynx and larynx. Significant differences between individuals were apparent for tissue samples from different donors. The genotoxic damage induced in cells of donors with a history of chronic alcohol consumption was significantly higher than in cells of patients without chronic abuse of alcohol. CONCLUSIONS: The data shows that DNA damage in human epithelial cells of the upper aerodigestive tract induced by environmental and occupational substances can be demonstrated using the microgel electrophoresis technique. The influence of chronic alcohol consumption on the genotoxic effects of substances such as NDELA and B(a)P showed the importance of evaluating preexisting compounding factors.

Adult↗
PubMed1999

Infection with GB virus C/hepatitis G virus among blood donors and hemophiliacs in Martinique, a Caribbean island.

GB virus C/hepatitis G virus (GBV-C/HGV) RNA was detected by reverse transcription-polymer- ase chain reaction with primers derived from the nonstructural region 3 (NS3) in 9 (4.1%) of 221 blood donors and 2 of 20 (10%) hemophilia patients in Martinique, French West Indies. Anti-E2 antibodies were found in sera from 33 (14.9%) of the blood donors and 5 (25%) of the hemophiliacs. None of the subjects was positive for both GBV-C/HGV RNA and anti-E2. Among the 20 hemophiliacs, 12 (60%) had anti-HCV antibodies and 7 (35%) were positive for HCV RNA by PCR. All patients positive for HCV markers belonged to the group of 13 patients exposed previously to blood factor concentrates that were not activated virally. Nucleotide sequences of the 5'-untranslated region (5'UTR) of the GBV-C/HGV genome were obtained for the 10 NS3 PCR positive samples. Phylogenetic comparison of these isolates with reference isolates published previously showed a strong homology with European and American GBV-C/HGV strains, 8 isolates belonging to the genotype 2a and 1 isolate to the type 2b. The isolate from 1 blood donor was identified as subtype 1a, indicating the presence of West African type strains.

5' Untranslated Regions↗
PubMed1998

Loss of human hippocampal adenosine A1 receptors in dementia: evidence for lack of specificity.

The density of hippocampal adenosine A1 receptors was measured in autopsy samples of six patients with dementia with either Alzheimer (three) or sclerosis type pathology (three) in hippocampus and six control patients. Kinetic parameters (Bmax and KD) were determined by means of quantitative autoradiography using [3H]8-cyclopentyl-1 ,3-dipropylxanthine as a radioligand. A significant 50% reduction of CA1 adenosine A1 receptors was observed in patients with dementia independent of the specific pathology. These results suggest that loss of hippocampal adenosine A1 receptors in dementia is not specific for Alzheimer type pathology.

Aged↗
PubMed1998

[Metastatic spread of renal cell carcinoma in the area of the ethmoid and frontal sinuses].

Metastatic lesions represent 1-8% of all malignant tumors of the mouth and jaws, with rare sites of metastasis originating from different primary tumors, especially the lung and breast. The vast majority of these lesions (up to 90%) have been observed in the mandible and maxilla (5-20%). Another rare type of cancer that usually metastasizes to the lungs, lymph nodes, bones, liver or brain may occasionally also show spread to the paranasal sinuses. In the present paper we report our management of a 50-year-old male with renal cell carcinoma who developed metastases to the frontal and ethmoid sinuses.

Carcinoma, Renal Cell↗
PubMed1998

[Exophytic papillomatous space-occupying lesions of the larynx as a rare manifestation of candidiasis. Diagnostic and therapeutic consequences].

Laryngeal candidiasis is very rare in the absence of other more proximal diseases in the aerodigestive tract. The lesion shows pseudoepitheliomatous hyperplasia or acanthosis and, given its rarity, may be confused with cancer. In the present paper we report on a 56-year-old male patient who presented with hoarseness. Physical examination of the larynx revealed a hyperplastic lesion involving both vocal cords. The clinical aspect and the risk factor profile of the patient (ten bottles of beer and 40 cigarettes per day) generated the clinical diagnosis of laryngeal cancer. A biopsy was taken. The histopathological examination of the specimen excluded a squamous cell carcinoma; however, it could not provide a clear diagnosis. Laryngeal papillomatosis and tuberculosis, which had been suspected, could be excluded. As the lesion progressed, further biopsies led to the diagnosis of candidiasis. Systemic antimycotic treatment with fluconazol and amphotericin caused a complete remission.

Amphotericin B↗
PubMed1998

[Exposed superior bulb of the internal jugular vein. Differential hearing loss diagnosis with pulse synchronous tinnitus].

A case report is presented of a 54-year-old woman with tinnitus synchronous with her pulse and an ipsilateral conductive hearing loss. Otoscopy showed a pulsatile structure behind the right eardrum. Imaging with high-resolution computed tomography of the temporal bone showed an enlarged jugular vein bulb. Magnetic resonance imaging could not be performed because of an implanted pacemaker. Since a glomus jugulare tumor could not be excluded right diagnostic tympanoscopy was performed and revealed a high jugular bulb that filled nearly a third of the tympanum.

Diagnosis, Differential↗