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Biomedical subjects

B M Lippert

Publications and source records attributed to B M Lippert.

At least 91 records · Page 5Linked to original sources
PubMed1996

[Incidence of point mutations in Ki-ras codon 12 and 13 in squamous epithelial carcinomas of the head-neck region].

BACKGROUND: Point mutations of ras genes are one of the most frequent genetic alterations in human malignancies with up to over 95% in certain tumors. Some studies have presumed a low incidence of point mutations in Ki-ras gene codons 12 and 13 in squamous cell carcinoma of the head and neck (SCCHN). The objective of this study was to gain more information about the significance of point mutations in Ki-ras codons 12 and 13 by investigation of a high number of cases. METHODS: By employing the polymerase chain reaction with specific primers, 63 fresh tumor biopsies were investigated by the nonradioisotopic single-strand conformation polymorphism (SSCP) analysis. To cooperate the efficiency and to characterize the nature of the point mutations, direct fluorescence-labeled DNA sequencing was performed in two cases. RESULTS: Five out of the 63 (7.9%) SCCHN samples exhibited point mutations in codons 12 and 13 by SSCP analysis. In two out of these mutated cases, a G to T transversion in codon 12.2 of the Ki-ras gene was detected. The analysis of the patient's clinical parameters as well as the histopathological grading and tumor staging revealed no correlation with the Ki-ras point mutation. CONCLUSIONS: Ki-ras point mutations in codons 12 and 13 are a rare event in SCCHN. These data give additional evidence that these genetic alterations do not play a major role in the development of malignancies of the upper aerodigestive tract.

Aged↗
PubMed1996

[Nd:YAG laser light-induced reduction of the nasal turbinates].

BACKGROUND: Different types of laser have been used for reduction of hyperplastic inferior turbinates in the recent years with good results. Reports about the long-term benefit of the laser treatment are rare. PATIENTS AND METHODS: At the Dept. of Otorhinolaryngology, Head and Neck Surgery, University of Kiel between 1987 and 1994, 89 patients with hyperplastic inferior turbinates were treated using the Nd:YAG laser. With the Nd:YAG laser, low-dose irradiation (laser power density: 1770-3540 W/cm2, non-contact-technique) of the entire turbinate is performed under endoscopic control. RESULTS: Twenty-seven patients (67.5%) who were treated by laser surgery were without complaints 6 months postoperatively. After one and two years, this applied to 29 (72.5%) and 26 (65%) patients, respectively. The success of treatment was seen after several months. The procedure involves little or no bleeding. The mucocillary clearance of the epiturbinate is not disturbed by Nd:YAG laser treatment. CONCLUSIONS: The Nd:YAG laser is suitable for the treatment of hyperplastic inferior turbinates. The disadvantages of the Nd:YAG laser therapy are that the success of treatment becomes evident only after weeks or months due to the scarring process which takes very long, and time consuming wound care is necessary.

Adult↗
PubMed1996

[Monoclonal antibodies against squamous epithelial carcinomas of the upper aerodigestive tract].

BACKGROUND: Squamous cell carcinoma is the most common cancer of the head and neck. The application of monoclonal hybridoma technology to the identification and characterization of molecules preferentially expressed in carcinoma cells may provide potentially important diagnostic and therapeutic tools. METHODS: After immunization of mice with viable squamous cell carcinoma cells derived from human tumors of the upper aerodigestive tract hybridomas were selectively grown for production of monoclonal antibodies. Monoclonal antibodies produced by 690 hybridoma clones were tested on immunoreactions with frozen sections of human squamous cell carcinoma and reactive tonsils. RESULTS: Immunohistochemical trials showed that monoclonal antibodies produced by hybridoma clone K-640 are strongly accumulated at the plasma membrane whereas no immunoreaction in squamous epithelium of the tonsil could be detected. By means of ELISA it could be shown that these antibodies belong to the class of IgM. Immunoblotting revealed that the antibodies recognize antigenes with approximate molecular weights of 52 and 54 kD. CONCLUSIONS: The experiments suggest that the hybridoma clone K-640 produces antibodies which bind to the plasmamembrane of the tumor cells. Further recloning steps of this hybridoma clone could possibly enhance the specificity of these antibodies for squamous cell carcinoma.

Animals↗
PubMed1996

Recurrent laryngeal papillomatosis. Retrospective analysis of 95 patients and review of the literature.

BACKGROUND: Laryngeal papillomatosis is a benign neoplastic disease which is associated with and probably by the Human Papilloma Virus. It can be of significant importance for affected patients because of its recurrent clinical course. A great variety of therapeutic measures have been described including surgical removal either with conventional instruments or by using the laser. The aim of this study was to compare these two methods. PATIENTS: The clinical courses of all patients (53 male, 42 female) treated at the Dept. of Otolaryngology, Head and Neck Surgery, University of Kiel since 1960 were analysed retrospectively. The two most common forms of treatment, surgical removal either conventionally or with the use of the laser, were compared. RESULTS: Laryngeal papillomatosis is a disease of all ages, but often initially diagnosed in the first and fourth decade. In 25 cases the onset was before the age of 16. Puberty had no effect on the clinical course. A malignant degeneration was observed in four cases. Although the different forms of treatment did not affect the rate of recurrence, the rate of complications such as tracheostomy and glottic webs was significantly reduced after laser surgery. Since the introduction of this new form of therapy no further tracheostomies had to be performed on these patients. CONCLUSION: The term juvenile laryngeal papillomatosis should be replaced by recurrent respiratory papillomatosis. One could then make a distinction according to the age of onset, i.e. in children below the age of 16 years and in adolescents and adults older than 15 years. The occurrence of squamous cell carcinomas in patients previously treated for papillomas underlines the need for repeated histological studies. Our studies have shown that surgical treatment remains the mainstay in the management of laryngeal papillomatosis, with laser surgical technique being superior to conventional removal.

Adolescent↗
PubMed1995

DNA amplification for the in vitro detection of Candida albicans in head and neck squamous cell carcinomas.

DNA was extracted from whole cells of Candida albicans and digested with HindIII restriction enzyme. After electrophoresis in a segment of the lane containing between 800 and 1200 base pairs (bp) of DNA fragments, a 1.1-kilobase (kb) fragment was found that hybridizes to biopsied tumor cells from head and neck squamous cell carcinomas (SCC). From the nucleotide sequence of the putative gene locus, primers were synthesized for use in a polymerase chain reaction (PCR) with DNA extracted from 18 SCC of the upper aerodigestive tract. After 30 cycles of amplification all tumors were found to contain sufficient amplified DNA to be detected in polyacrylamide or agarose gels. In contrast, template DNA from lymph nodes and malignant lymphomas failed to generate positive signals under these conditions. However, samples of DNA obtained from head and neck SCC cells in vitro, Candida glabrata, and Candida parapsilosis after PCR were found to contain homologous sequences. Application of this technique to head and neck SCC biopsies may help to identify quickly the presence of concurrent candidal species.

Base Composition↗
PubMed1995

[Serum soluble interleukin 2 receptor in patients with squamous epithelial carcinomas of the upper aerodigestive tract].

BACKGROUND: Several investigations showed increased levels of the soluble interleukin-2 receptor (sIL-2 R) in chronic and malignant diseases. A correlation between elevated sIL-2 R levels and disease activity or tumor size was observed in some patients. At present, there are no studies of sIL-2 R serum levels in patients with squamous cell carcinomas of the upper aerodigestive tract. METHODS: SIL-2 R levels were measured in sera of 86 patients with squamous cell carcinoma of the head and neck and of 25 healthy controls with a sandwich ELISA. RESULTS: Significantly elevated serum levels of sIL-2 R were detected in 49 out of 86 patients (56.9%) with squamous cell carcinoma of the head and neck. The mean serum level in the healthy controls was 437 U/ml compared to 895 U/ml in carcinoma patients. A correlation was found between tumor size, number of metastases and the sIL-2 R level. There was no correlation with histological type or tumor localization. DISCUSSION: The physiological role of sIL-2 R is still unknown. Elevated levels of sIL-2 could be a sign of activation of the immune system. But they also might be involved in causing the disease. The sIL-2 R serum levels in patients with squamous cell carcinoma of the head and neck may serve as an unspecific indicator for tumor size and dissemination. CONCLUSION: Posttherapeutic titer controls could be of prognostic value. Additionally, sIL-2 R may help to select appropriate patients for an immunotherapy with recombinant IL-2.

Adult↗
PubMed1995

[Establishment and characterization of 2 cell lines of squamous epithelial carcinoma of the mouth floor and tongue].

OBJECTIVE: The cultivation of squamous cell carcinoma cells of the upper aerodigestive tract is more difficult compared to other malignancies because of microbial contamination. The establishment of new squamous cell carcinoma cell lines is absolutely necessary to further characterize this tumor entity. METHODS: Two squamous cell carcinoma cell lines of the floor of the mouth and the tongue were established from tumor biopsies. They were examined by light and electron microscopy. Furthermore immunocytochemical and DNA cytofluorometric studies were performed. The growth features were tested in a tumor-stem cell assay and through transplantation in thymusless nude mice. RESULTS: The epithelial character of the cells was determined morphologically, immunocytochemically, and immunologically. Both cell lines shaved an aneuploid DNA Index of 1.92 for the tongue carcinoma cell line (HCTK-1) and 1.77 for the floor of the mouth cell line (HCFMK-1). The plating efficiency was 0.008 and 0.01%. Cell differentiation in the original tumor and the nude mice tumor was identical. HCTK-1 is in the 25th passage and HCFMK-1 in the 42nd. CONCLUSIONS: The two new squamous cell carcinoma cell lines HCFMK-1 and HCTK-1 may serve as a basis for various in vitro investigations and may help to further characterize squamous cell carcinomas of the upper aerodigestive tract.

Aged↗
PubMed1995

[Animal experiment studies of laser effects on lymphatic vessels. A contribution to the discussion of laser surgery segmental resection of carcinomas].

BACKGROUND: The potential effect of laser surgery on the process of lymphogenic metastases is subject to controversy. In this context it would be of interest to identify a morphological basis for an increased intraoperative entry of tumor cells into the lymphatic system during resection of advanced carcinomas in two or more pieces via laser surgery. METHODS: The tissue effect of laser incisions (CO2 laser: 3030 W/cm2; Nd:YAG-laser: 3180 W/cm2) on the lymphatics of the buccal mucosa in 60 Wistar rats was studied by light microscopy, histochemistry, and lymphography during surgery and subsequent wound healing. These incisions were compared to conventional scalpel incisions. RESULTS: No lymphatic vessels were detected in the zone of carbonization, they were mostly dilated whereas in the zone of edema. In the zone of necrosis, the lymphatic were occluded by coagulation. The mid and long-term effect of the laser light on the regeneration of lymphatics was mainly correlated to wound healing which--when compared to conventional surgery--is delayed after laser surgery. Following scalpel incision, the first lymphatics enter the wound region after 4 days, a opposed to 10 days following laser surgery. Intact continuity of the lymphatic vasculature was detectable 15 days after scalpel incision and 42 days after laser incision. The regeneration of lymphatics was slightly more delayed after CO2 laser incision than after Nd:YAG laser incision. CONCLUSION: The results of this study do not indicate that the laser resection of carcinomas facilitates an intraoperative entry of tumor cells into the lymphatic vasculature. These experimental results verify clinical reports which do not observe an increased frequency of postoperative metastases after laser resection of carcinomas in two or more pieces.

Animals↗
PubMed1995

[Results and surgical experiences in web transsection of hypopharyngeal (Zenker) diverticulum with the CO2 laser].

Since 1984 at the Department of Otorhinolaryngology, Head and Neck Surgery, University of Kiel, 34 patients with hypopharyngeal diverticular have been operated microendoscopically using the CO2 laser. Results and complications of this technique were compared to a group of patients in whom standard (non-laser) diverticulotomy was carried out from 1976 to 1993. Ninety per cent of the patients treated endoscopically with laser surgery have not had complaints and the rate of postoperative complications has been low. Three patients developed pharyngeal stenoses while one case incurred a mediastinitis. Intraoperative bleeding was not observed. In comparison to the microendoscopic procedure serious complications were more frequently observed in patients treated with the standard diverticulotomy. In eight of these cases paralysis of the recurrent laryngeal nerve occurred. A mediastinotomy was performed in another three patients because of mediastinitis. In two cases stenosis occurred after surgery and one patient developed a fistula. Endoscopic diverticulotomy utilizing a CO2 laser was found to be an excellent treatment for Zenker's diverticulum because of the good functional results achieved and low complication rate. The procedure was easy to perform because of the short duration and could be repeated frequently without significant additional risks.

Adult↗
PubMed1995

[The laryngeal lymph vessel system of the human. A morphologic and lymphography study with clinical viewpoints].

Laryngeal carcinomas have different metastatic characteristics depending on their locations. Although these changes could be explained by differences in density of the lymphatic system, studies of the laryngeal lymphatic system have been controversial. To clarify these differences the lymphatic systems of 184 organ specimens were investigated with light and electron microscopy, histochemistry and injection techniques. Three types of lymphatic vessels were found in the larynx: lymph sinuses, precollectors and collectors. The highest density of lymphatics was found in the supraglottic larynx. From this region, lymph drained via 3-6 collectors to a hypopharyngeal collector. The subglottic lymph mainly drained via 2-4 collectors to paratracheal and mediastinal lymph nodes. The lymph system of the vocal folds was sparse but drained mainly to the supraglottic larynx. No lymph collector was found in the mucosa of the vocal fold. According to these results, the incidence of lymphatic spread correlated first with the density of the initial lymphatics in the various laryngeal regions and secondly (and probably of greater significance) with nearness of tumor to the laryngeal collectors.

Endothelium, Lymphatic↗
PubMed1995

[Effect of various culture media on growth behavior of human squamous epithelial carcinoma cells of the upper aerodigestive tract].

Sera containing media are frequently used for cultivation of epithelial cells, but the influence of serum on analytic methods can be significant. For this reason the development of serum-free media is of great significance. We investigated the influence of serum-free medium on growth characteristics of human squamous cell carcinoma (SCC) cells of the upper aerodigestive tract and compared these in serum-containing media, using cloned SCC cell lines HLaC-78 and HCFMK-1. Three serum-containing culture media were used: MEM-Instamed, RPMI-1640 and MCDB-153, each containing 10% fetal calf serum. Serum-free culture medium was MCDB-153 supplemented with bovine hypophysis extract, insulin and ethanolamine. Results showed that supplement-enriched, serum-free medium was suitable for culturing SCC cells. When compared to serum-containing media, cell growth of the SCC cell lines was significantly higher in the serum-free medium.

Animals↗