[Skull base surgery in the German DRG system-New categorization of important procedures]. / Die Schädelbasischirurgie im deutschen DRG-System ­ Neue Zuordnung wichtiger Prozeduren.

Surgery of the skull base includes interventions between the nose or paranasal sinuses (anterior skull base) or ear/temporal bone (lateral skull base) and the intracranial space. As interventions at the anterior skull base almost exclusively involve complex pathologies in a demanding anatomical region, in many cases two experienced surgeons from different disciplines are required who should be experienced in operating together. The technical and time requirements are also considerable in many cases; however, for many procedures there are no specific skull base operational and procedural keys (OPS) codes that take the considerable personnel and structural effort into account. A change in the diagnosis-related groups (DRG) system, implemented since the beginning of 2023, now adjusts the remuneration of the abovementioned effort for malignant pathologies of the anterior and lateral skull base. The reallocation of procedures 5­015.0/1/3/4 and 5­016.0/2/4/6 results in a significant upgrade of anterior and lateral skull base surgery. Since the beginning of 2023 skull base surgery will no longer be charged under DRG D25C with a (former) relative weight of 1.893, but with DRG D25B with a current relative weight of 3.753 when a code of the aforementioned groups is used. Nevertheless, further adjustments are necessary, for example, in the available reconstructive steps in order to provide the Institute for the Remuneration System in Hospitals (InEK) with the most differentiated data possible on the procedural effort of the intervention and to achieve a more balanced distribution of the reimbursements of skull base surgery in the long term.

[Incidence, latency, and prognosis of local and regional recurrences in patients with upper aerodigestive tract cancer treated by laser microsurgery: influence of initial tumor parameters]. / Lokale und regionäre Rezidive von laserchirurgisch behandelten Plattenepithelkarzinomen des oberen Aerodigestivtrakts: Häufigkeit, Latenz und Prognose sowie Einfluss der initialen Tumorparameter.

INTRODUCTION: The aim of the present study is to identify clinical factors that influence the incidence and the prognosis of local and regional recurrences. PATIENTS AND METHODS: The data of 1,426 patients with newly diagnosed squamous cell carcinoma of the upper aerodigestive tract who were treated by curative laser microsurgery between August 1986 and December 2002 were reviewed. RESULTS: In 381 patients (27%), tumor recurrences were detected during follow-up. The frequency of local as well as regional recurrences significantly correlated with the initial stage of tumors. Recurrences of advanced carcinomas occurred considerably sooner than those of stage II and I cancer. During the 4th year of follow-up, patients with early stage disease had a recurrence rate twice as high as those with advanced carcinomas. Survival with recurrence was adversely affected by adjuvant radiotherapy as part of initial treatment, simultaneous local and regional manifestation of recurrence, male sex, advanced stage of initial disease, and by oral or hypopharyngeal site of the primary tumor. CONCLUSION: Early carcinomas of the upper aerodigestive tract recur at a lower rate than advanced stage diseases, but after a longer mean latency period. As a consequence, these patients should receive close follow-up also during the 3rd and 4th years after treatment, particularly as the prognosis of their recurrences is most often favorable.

Steroid RU 486 inducible myogenesis by 10T1/2 fibroblastic mouse cells.

For reconstruction or repair of damaged tissues, an artificially regulated switch from proliferation to differentiation would be of great advantage. To achieve conditional myogenesis, we expressed MyoD in mouse C3H 10T1/2 fibroblastic cells, using a gene regulation system based on the synthetic steroid RU 486. By stable co-transfection of a plasmid construct with the RU 486 dependent activator and an integrating inducible MyoD construct, a cell clone, designated 10T-RM, was obtained in which MyoD expression was stringently controlled by RU 486. 12 h after addition of 10 nM RU 486 to 10T-RM cells, saturation levels of MyoD mRNA were observed and >/=2 days later, mRNA for embryonal myosin heavy chain (MyHC(emb)) was abundant and mononucleated cells fused into myotubes.

Deletion in the Z-line region of the titin gene in a baby hamster kidney cell line, BHK-21-Bi.

The gene for titin, a 4MDa myofibrillar protein, was analysed in golden hamster DNAs from different sources, using human cDNA probes and PCR. In the DNA from the BHK-21-Bi subline of baby hamster kidney cells, extended sequences coding for Z-line associated domains were missing, indicating a deletion that renders titin non-functional. These sequences were present in the original BHK-21 line and in hamster DNAs. Our finding shows that, due to the absence of selective pressure on a gene's function, genomic deterioration can occur in a permanent cell line and can lead to a loss of overlapping DNA stretches in both autosomes.

Cytokinetic effects of cisplatin on diverse human head and neck carcinomas in vitro: dependence on the tumor sensitivity to cisplatin.

Studies performed with xenografted human head and neck carcinomas in vivo have demonstrated that the cytokinetic phenomena occurring under the influence of cisplatin closely correlate with the response of the tumors to therapy. The present paper analyses whether this correlation also exists in vitro. Four human head and neck carcinoma cell lines showing different degrees of sensitivity to cisplatin, as determined by the trypan blue exclusion assay, were investigated by flow cytometry at various intervals after administration of cisplatin. Early cell-cycle blockades in the S phase always reflected a high degree of cytostatic potency of cisplatin and were usually succeeded by a pronounced inhibition of tumor cell proliferation and a reduction of cell viability. In the case of a minimal response to therapy and in untreated control cultures of all four tumor lines, the relative number of S-phase cells continuously diminished during the observation period. These findings point to the S-phase blockade as the crucial cytokinetic effect of cisplatin preceding relevant growth reductions. This knowledge might support the development of a drug-response assay that could predict the sensitivity of individual patient tumors in vitro before the beginning of clinical cancer chemotherapy.

Value of 31P NMR spectroscopy in predicting the response of a xenografted human hypopharynx carcinoma to irradiation.

PURPOSE: An early indicator of tumor sensitivity to irradiation could provide useful information on the effectiveness of therapy and may facilitate more individual designs of treatment protocols. The aim of the present study was to evaluate the potential of in vivo 31P nuclear magnetic resonance spectroscopy in predicting the response of a xenografted human hypopharynx carcinoma to radiotherapy. METHODS: The tumor had been serially heterotransplanted to athymic mice. 31P NMR spectra were collected before and at four intervals (24, 48, 72, and 120 h) after irradiation with 15 Gy or 30 Gy. Alterations of phosphorus metabolism were compared with the growth delays, the histological appearance, and the mitotic activity of the treated tumors. RESULTS: Radiation with 30 Gy induced increases of the phosphodiester level (P < 0.001) as well as of the tumor pH (P < 0.05) and decreases of the phosphomonoester level (P < 0.001) within 48 h. The changes clearly preceded measurable tumor responses and were accompanied by severe histological destruction and marked depression of mitotic indices. However, none of these spectral alterations was significantly correlated with individual delays of tumor growth. The only parameters allowing a prediction of radiation-induced tumor responses were the pre-treatment levels of phosphomonoesters and -diesters. The 31P NMR spectroscopic changes observed after therapy with 15 Gy were either unsystematic or insignificant. CONCLUSIONS: Pretreatment levels of tumor phospholipids were indicative of radiosensitivity in the xenografted human hypopharynx carcinoma investigated here. However, since phosphorus metabolism varies considerably among different tumor lines, it seems unlikely that there exists a uniform 31P NMR spectroscopic parameter predicting tumor response to radiation therapy.

Influence of cisplatin on cell-cycle progression in xenografted human head and neck carcinomas.

The scope of the present study was to examine whether the cytokinetic phenomena occurring in human tumors under the influence of cisplatin correlate with the response of the tumors to therapy with the drug. Therefore, three strains of heterotransplanted human head and neck carcinomas showing different degrees of sensitivity to cisplatin were investigated by flow cytometry at various intervals after a single administration of cisplatin at four different dose levels (3, 6, 9 or 12 mg/kg). Three types of cell-cycle alterations were observed that depended on the dose of cisplatin and the degree of drug sensitivity shown by the tumors investigated. The obviously weakest kind of tumor reaction was a delay in the G2 cell phase. This phenomenon also occurred in the case of non-responsiveness to therapy, whereby the growth, histological structure and mitotic activity of the tumors remained nearly unaltered after cisplatin treatment. With increasing cytotoxicity, additional accumulations of cells in the S phase and, finally, long-lasting blocks at the G1/S boundary were found. The latter phenomenon, which manifested at high dose levels used in sensitive tumors, was obviously irreversible, as it did not completely disappear until the tumor cells had died and been removed by immigrating macrophages. It was always accompanied by severe histological destruction, tumor cell necrotization, and marked depression of the mitotic index. Thus, the hindrance of cell traversal through the S phase obviously represents the main and significant cytokinetic event, which indicates a potent antitumor effect for cisplatin that leads to pronounced tumor regression. This finding supports the hypothesis that inhibition of DNA synthesis is the mechanism underlying the cytotoxicity of cisplatin.

Proliferation behavior of xenografted human tumors: a flow cytometric study.

The proliferation behavior of three adenocarcinomas derived from the colon rectum, colon sigmoideum and the lung was pursued by flow cytophotometry between 0 h and 38 h after heterotransplantation to athymic mice. On principle, the same pattern of alterations was observed in the case of all three tumors, the time parameters slightly varying in dependence on growth velocity. At first, the number of intact tumor cells markedly decreased during 16-24 h after transplantation, being accompanied by an increase of cellular debris and an immigration of numerous host animal cells; the latter became the quantitatively preponderant portion of cells between days 2 and 8. On day 6, the tumor cell population began to proliferate. At first, the G1 peak rose, followed by the appearance of tumor cells in the S and (G2 + M) phases. Simulataneously, the relative portions of mouse cells and cellular debris diminished. Between days 14 and 30, when maximum rates of macroscopic growth of the heterotransplants were achieved, the cytokinetic features of the xenografts had stabilized and were characterized by the presence of a small portion of mouse cells and a prominent tumor cell population, most cells being in the G1 phase and a smaller number passing through the S and (G2 + M) phases. Beyond day 30, degeneration phenomena again occurred, which were reflected by a decay of mouse and tumor cell populations and a simultaneous increase of cell fragments. By cytokinetic means, the results of the present study reveal a multistep development of human tumors after heterotransplantation into nude mice, and confirm the importance of host-supplied cells for the removal of degenerated tumor cells and the induction of tumor cell proliferation. Moreover, the results show that a stable cytokinetic pattern is found only during the phase of macroscopic tumor growth and the following phase of steady state.

Effect of keratinocyte growth factor on the proliferation, clonogenic capacity and colony size of human epithelial tumour cells in vitro.

PURPOSE: The effect of recombinant human keratinocyte growth factor (rHuKGF) on the proliferation, clonogenic capacity and colony size of low-passage human epithelial tumour cells was tested in vitro. MATERIALS AND METHODS: Five tumour cell cultures derived from head and neck squamous cell carcinomas, three cultures derived from pleural effusions of carcinomas of different origin and normal human nasal epithelial cells were analysed in passages 2-4. Expression of FGF7 and its receptor (FGFR2) were determined by the RNase protection assay. Cells were incubated with rHuKGF (10-200 ng ml(-1)) 3 days before or immediately after plating for clonal growth in serum-depleted media. To determine cellular radiosensitivity, single doses of 1-8 Gy X-rays were applied. Colony formation as well as colony size, reflecting the number of cell divisions, was determined after 10-15 days of growth in rHuKGF-treated and control cells. RESULTS: Normal nasal epithelial cells showed a two- to threefold increase in the number of cell divisions due to rHuKGF-treatment. In tumour cell cultures, significant stimulation of proliferation occurred in only one of eight samples. Tumour cells expressed FGF7 mRNA and protein, and low levels of FGFR2 mRNA. The addition of rHuKGF to the medium of the tumour cell cultures influenced neither radiation-induced impairment of proliferation nor clonogenic cell survival. CONCLUSION: rHuKGF has been shown to ameliorate the radiation tolerance of normal epithelia. The minimum in vitro tumour cell response to rHuKGF compared with normal epithelial cells suggests a potential for selective protection of normal epithelia during radiotherapy. The low FGFR2 expression as well as the FGF7 expression in the tumour cells may contribute to their resistance to rHuKGF treatment.

The role of TTF-1 in differentiating primary and metastatic lung adenocarcinomas.

Thyroid transcription factor-1 (TTF-1) is a sensitive marker for pulmonary and thyroid adenocarcinomas. The aim of this work was to determine its usefulness in distinction between primary and metastatic lung adenocarcinomas. We have examined the expression of TTF-1 in 100 solitary pulmonary nodules. They included 50 stage I peripheral primary bronchial adenocarcinomas (30 men, 20 women, mean age: 60 years) and 50 metastatic pulmonary adenocarcinomas (21 men, 29 women, mean age: 57 years) of different origins, such as breast (13), colon (13), rectum (13), kidney (7), stomach (2), and thyroid gland (2). TTF-1 immunohistochemistry was performed on formalin-fixed, paraffin-embedded tissues. In primary bronchial adenocarcinomas we found immunopositivity in 46/50 cases, among them 30 cases showed strong nuclear immunostaining. In four primary adenocarcinoma cases the observed immunopositivity was localized to the cytoplasm. Out of the metastatic adenocarcinomas all but the 2 thyroid cancers were negative. Both thyroid tumors showed strong immunopositivity. Our results confirm that TTF-1 immunohistochemistry is a very sensitive and highly specific method in the differential diagnosis of primary and metastatic lung adenocarcinomas and should be used in the everyday clinical practice.

Effect of acquired cisplatin resistance on the response of a xenografted human hypopharynx carcinoma to concurrent radiochemotherapy with cisplatin.

The optimum integration of chemotherapy and irradiation is of potential clinical significance in the treatment of advanced head and neck carcinomas. In the present study, the interaction of cis-diamminedichloroplatinum(II) (cisplatin) with fractionated radiotherapy was investigated in a human hypopharynx carcinoma and a cisplatin-resistant subline of this tumor, both growing in athymic mice. Two radiochemotherapy schedules which tested single as well as combined-modality treatments were applied. After therapy, the tumor sizes were measured three times per week in order to determine growth delay and treatment:control (T/C) ratios. The results revealed approximately additive effects of both agents in the parent hypopharynx carcinoma. In the resistant subline, such an interaction did not appear after treatment with any of the investigated schedules. However, a significant cross-resistance between cisplatin and radiation was detectable. It can be concluded that multiple courses of a platinum-based induction chemotherapy may be disadvantageous, since the treated tumors may develop drug resistance which obviously limits the effectiveness of a subsequent combined-modality approach.

Prognostic significance of p53/bcl-2 co-expression in patients with laryngeal squamous cell carcinoma.

OBJECTIVE: The p53, bcl-2, and bax genes are known to be involved in control of cell cycle progression and regulation of apoptotic cell death. Although they are frequently altered in laryngeal squamous cell carcinoma, their clinical relevance is not yet fully understood. In the present study, individual and combined expressions of these genes were related with patient survival as well as with proliferative and apoptotic activity. DESIGN: Retrospective study. METHODS: Paraffin-embedded tissue sections of 88 laryngeal squamous cell carcinomas that were diagnosed and treated between 1986 and 1996 were investigated for p53, bcl-2, and bax protein expression by immunohistochemistry. Apoptotic cells were visualized using the nick end labeling method. To assess proliferative activity of tumors, mitotic indices were determined. RESULTS: Age of patients, advanced disease (stages HI and IV), high mitotic activity, positive bcl-2 expression, high level of p53 expression, and p53/bcl-2 co-expression were significantly associated with shortened overall survival in univariate analysis. In multivariate analysis, only age and p53/bcl-2 co-expression had independent prognostic value. Other combinations of genes, i.e., bcl-2-to-bax and p53-to-bax ratios, were not associated with patient outcome. A significant positive correlation was found between apoptotic and mitotic activity. However, protein levels of p53, bcl-2, and bax were unrelated to proliferation and apoptosis of tumor cells. CONCLUSIONS: The co-expression of p53/bcl-2 was an independent predictor of patient outcome and had a prognostic value superior to both parameters considered separately. The rate of apoptosis mainly counterbalanced proliferative activity but appeared not to be significantly influenced by p53, bcl-2, and bax.

Radiotherapy combined with simultaneous chemotherapy with mitomycin-C and 5-fluorouracil for inoperable head and neck cancer.

The feasibility and effectiveness of a combined chemoradiotherapy treatment modality for locally advanced head and neck cancer was tested in a phase II trial. From March 1995 to June 1998, 35 patients with advanced squamous cell carcinoma of the head and neck were treated with a continuous intravenous infusion of 5-fluorouracil (600 mg m-2 24 h-1 for Days 1 to 5 (120 h)) and mitomycin-C (10 mg m-2 intravenously) on Day 5 during the first week of radiotherapy and on Day 36. 31 patients had stage IV disease; 4 patients had stage III; and 1 patient had stage II. Patient ages ranged from 42-69 years (median 56.7 years). The tumours involved were as follows: oral cavity (n = 11); oropharynx (n = 14); hypopharynx/larynx (n = 10). Radiotherapy was delivered to a total dose of 70 Gy with conventional fractionation (2 Gy per fraction, five times a week). Chemotherapy was well tolerated and all patients received the intended dose. Mild nausea occurred in five patients. After a mean follow-up of 21 months (range 10-44 months), 8 (23%) patients remain alive. A complete response was seen in 28 (80%) patients. When a recurrence appeared, it was within the first year after treatment. 1- and 2-year overall survival rates were 46% and 23%, respectively. Grade 3 mucositis occurred in 17% of patients. Grade 1-2 thrombopaenia occurred in 3 (9%) patients, grade > 2 leukopaenia in 4 (11%) patients, and grade > or = 2 anaemia in 3 (9%) patients. We observed a treatment interruption of maximum 1 week for six patients owing to mucositis. Febrile neutropaenia or aplasia were not observed. The concomitant use of 5-fluorouracil, mitomycin-C and radiotherapy in locally advanced head and neck carcinoma is well tolerated in this group of patients. This protocol showed good locoregional response with a very low toxicity profile.

Tenascin expression and angiogenesis in breast cancers.

The expression and the distribution of tenascin as well as the extent of blood vessel formation (angiogenesis) were investigated in 70 invasive human breast carcinomas. Formalin-fixed, paraffin-embedded specimens were stained with monoclonal antibody against tenascin-C (DAKO and Biogenex). Anti-CD31 antibody (Biogenex), an acknowledged marker of stromal angiogenesis, was used to detect endothelial cells. Tenascin immunostaining was positive in the tumours around the persisting normal ducts, around tumour-cell nests, in the neostroma, in some tumour cells, and it was found in or around vascular channels. Tumour vascularity was assessed by quantitative vascular grading (Chalkley point count) and was related to the localization and intensity of tenascin immunoreactivity. 19 tumours (27.1%) were scored as low, 35 (50%) as medium, and 16 (22.9%) as having a high vascular grade. The positive correlation between the vascular grade and the tenascin immunopositivity in tumour stroma was observed. Our results suggest that tenascin expression may be associated with endothelial cell activation and may play an important role in tumour angiogenesis.

Study of inflammatory responses to crocidolite and basalt wool in the rat lung.

The subacute effects of crocidolite and basalt wool dusts were studied by nmeans of biochemical, morphological. and histological methods 1 and .3 mo after intrabronchial instillation. The cell count, protein and phospholipid contents, and lactate dehydrogenase (LDH) activity were determined in the bronchoalveolar lavage (BAL). Both types of fibers induced a prolonged inflammatory reaction in the lung. All the parameters studied in the experimental groups were more markedly elevated after 3 mo. Relative to the control, the protein and LDH values were increased three- to fivefold, the phospholipid content twofold, and the number of free cells in the BAL exceeded the control level up to ninefold. The inflammatory responses to crocidolite and basalt wool in the lung did not differ significantly. In spite of this, basalt wool is recoinmended as an asbestos substitute, as the use of this man-nade fiber may result in a significantly lower release of dust than that from crocidolite.

Interruption of classic CD40L-CD40 signalling but not of the novel CD40L-Mac-1 interaction limits arterial neointima formation in mice.

The co-stimulatory immune molecule CD40L figures prominently in a variety of inflammatory conditions including arterial disease. Recently, we made the surprising finding that CD40L mediates atherogenesis independently of its classic receptor CD40 via a novel interaction with the leukocyte integrin Mac-1. Here, we hypothesised that selective blockade of the CD40L-Mac-1 interaction may also retard restenosis. We induced neointima formation in C57/BL6 mice by ligation of the left carotid artery. Mice were randomised to daily intraperitoneal injections of either cM7, a small peptide selectively inhibiting the CD40L-Mac-1 interaction, scM7, a scrambled control peptide, or saline for 28 days. Interestingly, cM7-treated mice developed neointima of similar size compared with mice receiving the control peptide or saline as assessed by computer-assisted analysis of histological cross sections. These data demonstrate that the CD40L-Mac-1 interaction is not required for the development of restenosis. In contrast, CD40-deficient mice subjected to carotid ligation in parallel, developed significantly reduced neointimal lesions compared with respective wild-type controls (2872 ± 843 µm² vs 35469 ± 11870 µm²). Flow cytometry in CD40-deficient mice revealed reduced formation of platelet-granulocyte and platelet-inflammatory monocyte- aggregates. In vitro, supernatants of CD40-deficient platelet-leukocyte aggregates attenuated proliferation and increased apoptosis of smooth muscle cells. Unlike in the setting of atherosclerosis, CD40L mediates neointima formation via its classic receptor CD40 rather than via its recently described novel interaction with Mac-1. Therefore, selective targeting of CD40L-Mac-1 binding does not appear to be a favorable strategy to fight restenosis.