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Biomedical subjects

A Dietz

Publications and source records attributed to A Dietz.

At least 19 recordsLinked to original sources
PubMed2000

[Antimycotic therapy in otomycosis with tympanic membrane perforation].

Especially after prolonged antibiotic ototopic therapy otomycosis is not rare. An inoculation of fungi into the tympanic cavity however may have serious sequelae. Therefore an eradication of fungi from the external auditory canal is imperative before surgery. In addition to thorough cleaning of the outer ear canal antimycotic preparations are recommended in treating otomycosis. However, all of the commercially available ear drops contain ototoxic agents. In the case of defects of the tympanic membrane a damage of the inner ear may result. Alternatively, we suggest an aqueous solution of Miconazol 0,5%.

Administration, Topical↗
PubMed2000

[Herpes simplex virus type 1-induced rising dbl quote, left (low)tumor" in the nasal vestibule. The problem of resistance development of herpes simplex in a patient with chronic lymphatic B-cell leukemia].

Herpes simplex viruses are known to be among the most common disease-causing microorganisms. Their prevalence can exceed 90% depending on the socioeconomic status of the population. Since the number of immunocompromised patients has increased because of the increased incidence in the acquired immunodeficiency syndrome and an increase in organ transplantation, herpes virus infection may have a greater clinical significance. While treatment of otherwise healthy individuals will not usually cause any clinical problems herpes infection in an immunocompromised patient can have severe consequences. Additionally, development of viral resistance can be observed that may require alternative drugs in treatment. We present a case history of a man with a B-cell chronic lymphocytic leukemia that was associated with a very unusual herpes simplex virus infection in the nasal vestibule. Possible causes for the development of resistance in herpes infections and the use of famciclovir and forscarnet as two therapeutic alternatives to aciclovir are discussed.

Antiviral Agents↗
PubMed2000

Oxygenation of advanced head and neck cancer: prognostic marker for the response to primary radiochemotherapy.

Recent clinical studies suggest that the degree of tumor oxygenation may be predictive of the response of radiation therapy for cancer. In an exploratory investigation of cervical lymph node metastases in 27 patients with advanced squamous cell carcinoma of the oropharynx and hypopharynx, this relationship was investigated by means of oxygen measurements with an Eppendorf PO (2) histograph. The measurements were made before the start of radiation therapy and after the first week of therapy. Clinical response was evaluated 6 weeks after the completion of therapy. Before therapy, marked hypoxia was observed in the lymph node metastases, with a mean PO (2) value of 16.1 +/- 8.2 mm Hg and a hypoxic fraction (PO (2) < 10 mm Hg) of 56.4% +/- 20.0%. After the first week of radiation (9 Gy) there was a general reoxygenation (DeltaPO (2) = 5.0 +/- 10.1 mm Hg, P < 0.05; Deltahypoxic fraction = -11.3% +/- 31.3%, P = 0.11). A relationship between the degree of reoxygenation and tumor response was not observed. Patients without at least partial lymph node response (n = 8) showed poorer pretherapeutic oxygenation (PO (2) mean = 11.1 +/- 2.9 mm Hg) than those who responded to the therapy (n = 19, PO (2) mean = 18.2 +/- 8.8 mm Hg). In this investigation of a defined set of patients with advanced carcinoma of the oropharynx and hypopharynx, we found that pretherapeutic oxygenation data are predictive for the therapeutic response to radiation therapy or radiochemotherapy.

Adult↗
PubMed2000

Prognostic assessment of sonography and tumor volumetry in advanced cancer of the head and neck by use of doppler ultrasonography.

OBJECTIVE: The objective of this trial was to examine the degree of tumor vascularity in lymph node metastases as depicted by computer-assisted color Doppler sonography and the tumor volumes associated with prognosis in carcinomas of the oropharynx and hypopharynx after primary radiochemotherapy. PATIENTS AND METHODS: In a prospective trial, 25 patients with advanced squamous cell carcinomas of the oropharynx and hypopharynx (stage IV UICC 1997) were treated with radiochemotherapy. The color Doppler findings were quantified with a computer-assisted protocol that quantitatively describes color Doppler images by the relative color pixel density (CPD). As important prognostic cofactor, total tumor volume (TTV) was calculated from CT sections and related to the degree of vascularity. RESULTS: Low CPD in neck metastases showed a correlation with better overall survival. A high-CPD group and a high-TTV group (median survival 10.1 months) were determined and were compared with all other CPD/TTV combinations (median survival 28.4 months); the difference in survival was significant (P = 0.002). CONCLUSION: The results indicate that high tumor vascularity in combination with high TTV indicates a particularly bad prognosis in patients treated with primary radiochemotherapy for head and neck cancer.

Adult↗
PubMed1999

Alterations of intratumoral pharmacokinetics of 5-fluorouracil in head and neck carcinoma during simultaneous radiochemotherapy.

The kinetics of local drug uptake and metabolism of the anticancer drug 5-fluorouracil (5-FU) has been monitored by means of 19F nuclear magnetic resonance spectroscopy in 17 patients with neck tumors during concurrent radiochemotherapy. All of the patients underwent an accelerated hyperfractionated, concomitant-boost radiochemotherapy with 5-FU [600 or 1000 mg/m2 of body surface (b.s.)] and carboplatin (70 mg/m2 of b.s.). Serial 19F nuclear magnetic resonance spectra were obtained during and after the administration of 5-FU in a 15-T scanner with the use of a 5-cm diameter surface coil positioned on a cervical lymph node metastasis. Examinations were performed at day 1 of therapy and, in 13 patients, also after 43.5 Gy of irradiation at day 1 of the second chemotherapy cycle. Resonances of 5-FU and the catabolites 5,6-dihydro-5-fluorouracil (DHFU) and alpha-fluoro-beta-alanine (FBAL) were resolved in the tumor spectra. The median of the 5-FU and FBAL levels was significantly higher (more than 2-fold) at the second compared with the first examination, whereas the level of DHFU did not change. This effect could indicate an increased delivery of 5-FU into the interstitial space of the tumor in the course of the combined treatment, which would result in an enhanced exposure of the tumor cells to the drug. A potential mechanism for synergy between radio- and chemotherapy is discussed, but alternative mechanisms are also being considered. The findings indicate that a method is available to rationally address the design of dosing schedules in concurrent therapy regimens.

Adult↗
PubMed1999

[Predictive value of serum levels of basic fibroblast growth factor, vascular endothelial growth factor and matrix metalloproteinase-2 in advanced carcinomas of the head and neck].

The objective of this trial was to analyse the predictive character of the angiogenic factors vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF) and matrix metalloproteinase-2 (MMP-2) in the sera of patients with advanced carcinomas of the head and neck treated by primary radiochemotherapy. From 1992 to 1995, 25 patients with UICC stage cancers and one patient with stage III disease were treated in the departments of otolaryngology and radio-oncology of the University of Heidelberg according to a protocol of accelerated concomitant boost radiochemotherapy with carboplatin. The serum levels of VEGF, bFGF and MMP-2 were measured by enzyme-linked radiosorbent assay and data were correlated with followup findings (median time of follow up: 60 months). Patients with serum levels above normal were detected for VEGF in 4 patients, MMP-2 in 7 patients and for bFGF in 13 patients. An increase in bFGF serum levels above the upper limit of normal controls was significantly associated with a shorter time of locoregional control (P=0.036). In a covariate analysis bFGF proved to be independent of other prognostic factors, such as age, site, total tumor volume and response to therapy. No prognostic relevance of VEGF and MMP2 serum levels could be determined. The present suggest that bFGF is an independent prognostic factor for tumor control in advanced head and neck cancer after primary radiochemotherapy.

Adult↗
PubMed1999

[Construction workers as an extreme risk group for head and neck cancer?].

BACKGROUND: Workers in the construction industry carry an increased risk for head and neck cancer due to the high consumption of alcohol and tobacco plus exposure to occupational carcinogenic or co-carcinogenic agents. These latter substances include asbestos, tar products, metal dust, wood dust, cement dust and paints. RESULTS: The Heidelberg case-control studies showed a statistically increased risk of pharyngeal cancer (RR=2.5 adjusted for tobacco and alcohol) and laryngeal cancer (RR=2.3 adjusted for tobacco and alcohol) in the construction workers (23.3%) when compared to controls (8.2%). A random sample analysis of patients with head and neck cancer referred by the largest health assurance company in Heidelberg (AOK), revealed that 21.2% were employed in the construction industry. Similar results have been obtained in a number of international epidemiological studies. CONCLUSIONS: Our findings show that male construction workers who regularly consume alcohol and tobacco represent an extreme risk group for head and neck cancer. Measures for early detection are important and must be implemented carefully.

Adult↗
PubMed1999

[Prognostic significance of cell-cycle regulatory proteins for outcome after primary radiochemotherapy in patients with advanced head and neck cancer].

BACKGROUND: Primary radiochemotherapy is gaining increasing importance for the treatment of advanced head and neck squamous cell carcinomas. However, there is a lack of clinical factors concerning prognostic information in relation to treatment. In this pilot study, we examined whether molecular factors can provide such information. PATIENTS AND METHODS: The expression patterns and their possible prognostic relevance of the cell cycle regulatory proteins p53, p21(WAF/CIP1), Rb, p16(INK4A), CDK4 and Cyclin D1, MIB1 (Ki-67) and BCL-2 were analysed in pretreatment tumor biopsies from 43 patients with advanced carcinomas of the oropharynx (n = 26), hypopharynx (n = 10) and larynx (n = 7) by applying immunohistochemistry to paraffin sections of tumor specimens. All patients were treated by the same method of an accelerated "concomitant boost" radiochemotherapy with carboplatin in a phase II study. Median followup time was 56 months. RESULTS: No correlation was found between any of the markers and the remission rate, T-stage, N-stage, rate of loco-regional recurrences and distant metastases. However, independent of the tumor stage, patients with CDK4/cyclin-D1 overexpressing tumors had a significantly shortened overall survival (P = 0.014 and 0.026, respectively). CONCLUSION: The results of this pilot study indicate that CDK4 and cyclin D1 over-expression provide useful prognostic information about clinical outcome after primary radiochemotherapy of head and neck cancer patients.

Adult↗
PubMed1999

[The role of oncogenic human papillomaviruses in tonsillar squamous cell carcinomas with functional inactivation of the retinoblastoma protein].

In order to identify squamous cell carcinomas of the head and neck (HNSCC) with common biological and clinical features, we investigated the incidence and properties of carcinomas lacking retinoblastoma protein (pR6) cell cycle control. Of 208 HNSCC investigated, 23 (11%) showed a lack of pRb expression. The majority of these tumors (65%) were tonsillar carcinomas. The pRb-negative tonsillar tumors were all stage IV, had metastasized to lymph nodes at the time of diagnosis and were in general poorly differentiated or undifferentiated. Very significantly, the pRb-negative phenotype was strongly associated with the presence of oncogenic human papilloma viruses, implying a viral etiology and functional inactivation of pRb by the viral E7 oncoprotein. Despite the very adverse histopathological factors, patients with pRb-negative tonsillar carcinomas had a better clinical outcome, which was consistent with a uniform favorable responsiveness of these tumors to postoperative radiation therapy.

Carcinoma, Squamous Cell↗
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

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

Acute and late toxicity, tumour control and intrinsic radiosensitivity of primary fibroblasts in vitro of patients with advanced head and neck cancer after concomitant boost radiochemotherapy.

BACKGROUND AND PURPOSE: The existence of hereditary factors influencing the cellular response to ionising radiation has led to the hypothesis that the inter-patient variability of clinical radiation reactions may, at least in part, be attributable to an individual, or intrinsic, radiosensitivity. Considerable effort has been spent in the development of test systems that would determine individual radiosensitivity before or early during radiotherapy to possibly predict treatment outcome, but the results are still conflicting. The present explorative study was therefore aimed at the detection of associations between acute and late radiation effects, tumour control and in vitro radiosensitivity of primary normal tissue fibroblasts. PATIENTS AND METHODS: Sixty-eight patients with squamous cell carcinoma of the head and neck (93% UICC stage IV) were treated with a simultaneous concomitant boost radiochemotherapy with Carboplatin as part of a prospective non-randomised multicenter study at the University of Heidelberg. Primary fibroblasts were obtained from skin biopsies prior to treatment from 25 unselected patients of this study and the SF2 was determined using the colony forming assay and high dose-rate irradiation. The median follow-up was 21 months (range 2.5-81 months). RESULTS: The locoregional control rate at three years was 32%. No significant association between acute (mucosa reaction grade 1 or 2 vs. grade 3 and 4), late radiation effects (subcutaneous fibrosis, osteonecrosis, larynx oedema), locoregional tumour control and SF2 of primary fibroblasts was found using Cox proportional hazards regression analysis, log-rank test and Mann-Whitney U-test. Although a steep dose-response relationship was observed for the radiation-induced severe larynx oedema, Cox proportional hazards regression analysis could not fully explain the occurrence of severe radiation-induced larynx oedema with the dose to the larynx (P = 0.09). In the subgroup of twenty-five patients, where the SF2 was determined, bivariate analysis revealed about the same non-significant influence of the dose to the larynx on the larynx oedema (P = 0.1) and no influence of the SF2 (P = 0.5). CONCLUSIONS: In our study of patients with advanced cancer of the head and neck, neither the normal fibroblast SF2 nor the severity of acute radiation effects were able to predict late radiation effects or locoregional tumour control.

Adult↗
PubMed1999

Rise of oxygenation in cervical lymph node metastasis during the initial course of radiochemotherapy.

It has been hypothesized that during radiation treatment a reoxygenation of hypoxic tumor tissue takes place. To test this hypothesis, we have investigated whether reoxygenation in lymph node metastases could be determined by invasive PO (2) measurements. Through a hypodermic needle inserted transcutaneously into tumor-positive lymph nodes, polarographic oxygen determinations were made in 18 patients with advanced squamous cell carcinomas of the oropharynx and hypopharynx. These measurements were performed before therapy and a week after the onset of radiotherapy or radiochemotherapy, respectively. Low PO (2) values before treatment (mean value of the patient's median was 12.6 mm Hg PO (2)) and a mean hypoxic fraction (PO (2) < 5 mm Hg) of 39.6% indicated manifest tumor hypoxia. After 1 week of treatment, a significant increase in the median PO (2) (mean value of shift: 7.3 mm Hg) and a reduction in the hypoxic fraction (mean value of shift: 13.4% PO (2) < 5 mm Hg, P < 0.03) were observed after both radiotherapy and radiochemotherapy. Thus invasive PO (2) histography fulfills the requirements for a method to confirm tumor hypoxia in head and neck tumors. The results obtained indicate that reoxygenation occurs during the initial phases of radiotherapy and radiochemotherapy, and they will form the basis for future comparative investigations on the possible influence of hypoxic parameters on tumor responsiveness toward radiation and radiochemotherapy.

Adult↗
PubMed1998

TP53 DNA contact mutations are selectively associated with allelic loss and have a strong clinical impact in head and neck cancer.

Recent studies have suggested that different mutation types within the core domain of the tumour suppressor protein p53, i.e. DNA contact mutations and structural mutations, confer different biological properties. We have analysed in 86 head and neck squamous cell carcinomas (HNSCC), whether these p53 mutation types have a differential clinical impact. Thirty-seven missense mutations were identified. Thirteen of these (36%) were DNA contact mutations, occurring in the L3 loop, in the H2 loop sheet helix motif, in the S10 beta strand and in Zinc binding residues. Microsatellite marker analysis revealed a selective association between these mutations and the loss of wild-type alleles (100% LOH vs 50% LOH in tumours with structural mutations; P=0.0034, Fisher's exact, 2-tailed). In comparison to structural mutations or to the absence of mutations in the core domain, DNA contact mutations were associated with higher tumour stages (84.6% vs 62%), a higher incidence of lymph node metastasis (91.7% vs 56%; P=0.014, Fisher's exact, 2-tailed), a shortened recurrence-free survival (8.1 months vs 23.7 months, P=0.047, log rank test) and overall survival (11 months vs 29.2 months; P=0.003, log rank test). The latter was also the case when only stage IV tumours were analysed (P=0.0055, log rank test). These data indicate that in HNSCC, TP53 DNA contact mutations confer a strong selection pressure to eliminate wild-type alleles, and that they result in an accelerated tumour progression and reduced therapeutic responsiveness.

Adult↗
PubMed1998

Etiological involvement of oncogenic human papillomavirus in tonsillar squamous cell carcinomas lacking retinoblastoma cell cycle control.

Two hundred eight primary squamous cell carcinomas of the head and neck have been analyzed with respect to the presence of the retinoblastoma tumor suppressor protein, pRb. Of these, 23 tumors (11%) that preferentially localized to the tonsils revealed complete absence or dramatic reduction in the amount of pRb. Other cell cycle components, cyclin D1 and p16INK4A, which are intimately related to pRb through an autoregulatory loop, were also dramatically decreased or overexpressed, respectively, in these pRb-defective tumors. On the other hand, the majority of the pRb-defective tumors contained the wild-type p53 gene. No evidence was found for genetic defects at the Rb locus in these tumors. Very significantly, in 11 of 12 pRb-defective tonsillar tumors, but in none of 9 pRb-positive tonsillar tumors (P < 10[-7]), DNA of oncogenic human papillomavirus types was identified, providing a strong indication for a human papillomavirus-associated etiology of these tumors and suggesting the functional inactivation of the pRb protein by the viral E7 gene product. In comparison to all head and neck squamous cell carcinomas studied, the pRb-defective tonsillar tumors were in general more poorly differentiated (P = 0.0059), and they were all metastatic at the time of resection. Of particular clinical interest, despite these adverse histopathological factors, the clinical outcome for these patients was relatively favorable, strongly implying that the pRb-defective tumors responded uniformly well toward postoperative radiation therapy.

Carcinoma, Squamous Cell↗