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Biomedical subjects

D Esser

Publications and source records attributed to D Esser.

At least 19 recordsLinked to original sources
PubMed2005

[The interesting case -- case no. 68. Metastasis of a small-cell bronchial carcinoma to the parotid gland].

We present a case of a metastasis to the parotid gland from a small cell carcinoma of lung. The patient noted swelling in right parotid region without pain and saw an otorhinolaryngologist. There was no facial nerve palsy. He was admitted to our hospital. The total parotidectomy with facial nerve preserving was performed. The pathological findings indicated small cell carcinoma. After receipt of this report, we examined the lungs. An abnormal shadow could be found in the chest X-rays. CT revealed a lung tumor on a left site which was determined to be small cell carcinoma by transbronchial lung biopsy. Metastasis to the parotid glands from any distant primary site is quite unusual. In most cases of secundary parotid involvement of malignant tumors primary tumors originated from the head and neck region. Primary tumors in the neighborhood are the skin of the head and neck and the mucosa of the upper airway and digestive tract. Distant metastases to the parotid gland have been reported to arise from bronchial carcinoma, renal carcinoma, colonic carcinoma, prostat and breast. The distinction between primary salivary glands tumors and metastases of other primary tumors is difficult often. Histologic and immunhistological methods can be helpful.

Biomarkers, Tumor↗
PubMed2004

Complement regulation at the molecular level: the structure of decay-accelerating factor.

The human complement regulator CD55 is a key molecule protecting self-cells from complement-mediated lysis. X-ray diffraction and analytical ultracentrifugation data reveal a rod-like arrangement of four short consensus repeat (SCR) domains in both the crystal and solution. The stalk linking the four SCR domains to the glycosylphosphatidylinositol anchor is extended by the addition of 11 highly charged O-glycans and positions the domains an estimated 177 A above the membrane. Mutation mapping and hydrophobic potential analysis suggest that the interaction with the convertase, and thus complement regulation, depends on the burial of a hydrophobic patch centered on the linker between SCR domains 2 and 3.

CD55 Antigens↗
PubMed2004

[Magnetic resonance angiography of the head and neck area].

Magnetic resonance angiography is a noninvasive method in vascular imaging using non-contrast-enhanced and contrast-enhanced techniques. The contrast media used in contrast-enhanced magnetic resonance angiography are different from the X-ray contrast media and do not affect the thyroid gland or renal function. In detecting hyper-vascularized lesions in the head and neck, contrast-enhanced magnetic resonance angiography is the method of choice, which provides an acceptable quality in comparison to digital subtraction angiography. Future developments in magnetic resonance imaging techniques will cause a wider use of magnetic resonance angiography, especially in head and neck imaging. Digital subtraction angiography should therefore only be used in problem cases and for preoperative embolization.

Angiography, Digital Subtraction↗
PubMed2004

[Magnetic resonance angiography in the head-neck area].

Magnetic resonance angiography is a noninvasive method in vascular imaging using non-contrast-enhanced and contrast-enhanced techniques. The contrast media used in contrast-enhanced magnetic resonance angiography are different from the X-ray contrast me-dia and do not affect the thyroid gland or renal function. In detecting hypervascularized lesions in the head and neck, contrast-enhanced magnetic resonance angiography is the method of choice, which provides an acceptable quality in comparison to digital subtraction angiography. Future developments in magnetic resonance imaging techniques will cause a wider use of magnetic resonance angiography, especially in head and neck imaging. Digital subtraction angiography should therefore only be used in problem cases and for preoperative embolization.

Angiography, Digital Subtraction↗
PubMed2003

[Atypical course of cervical vessels--2 case reports].

BACKGROUND: The atypical course of cervical arteries can be reason for vascular complications including stroke and persistent neurological deficits in surgery in the cervical region. METHODS: Computed tomography and magnetic resonance imaging including angiographic procedures such as contrast enhanced magnetic resonance angiography are suitable to detect atypical course of cervical arteries. RESULTS: The two cases demonstrate rare variants of atypical course of cervical arteries detected by computed tomography and magnetic resonance imaging including contrast enhanced magnetic resonance angiography. The knowledge of these variants is important for planning of surgical intervention. CONCLUSIONS: Modern imaging techniques such as computed tomography and magnetic resonance imaging including contrast enhanced magnetic resonance angiography should be used for detection of suspected variants in the course of cervical arteries. The relevant structures and the abnormalities can be clearly defined.

Aged↗
PubMed2002

[Therapy of acute mastoiditis].

BACKGROUND: Acute otitis media is a common disease, mostly contracted at childhood. The development of acute mastoiditis has been decreased since the introduction of antibiotics. Currently it is only developed in 0.004 % cases of acute otitis media. But despite of this fact, even today one should not neglect this condition as the complications such as intracranial spread and lateral sinus thrombosis are still life threatening. METHODS AND PATIENTS: In a retrospective study from 01/96 - 09/00 we reviewed the cases of acute mastoiditis as a result of acute otitis media at our department. Additionally we compared study results out of 1972 until 1989 with our current results. RESULTS: Altogether mastoidectomy has been carried out at 157 patients. The cases have steadily increased since 1996. This is confirmed by comparison with study results of previous years. The majority of the patients were between 8 months and 3 years old (60 %). When the patients first presented at our department, the first signs of otitis media were 19.5 days ago in average. 38 % of the patients received no antibiotic treatment before admission. A thickened mucous membrane was seen by the mastoidectomy mostly (58 %). A subperiostal abscess we noted in 8.5 %. The most common isolated bacteria were Streptococcus pneumoniae (33 %) and Streptococcus pyogenes (11 %). The patients stayed at the department about 10 days. In comparison to recent study results the "typical" mastoiditis has decreased. The causative pathogens have not changed. CONCLUSIONS: In the last years we realised an increasing number of mastoiditis at our department. The isolated bacteria are the same as presented in the literature. Early surgery combined with an effective antibiotic treatment can avoid the known complications of mastoiditis.

Acute Disease↗
PubMed2000

A hyperthermostable bacterial histone-like protein as an efficient mediator for transfection of eukaryotic cells.

Gene delivery has shown potential in a variety of applications, including basic research, therapies for inborn genetic defects, cancer, AIDS, tissue engineering, and vaccination. Most available systems have serious drawbacks, such as safety hazards, inefficiency under in vivo-like conditions, and expensive production. When using naked DNA, for instance, a large amount of ultrapure DNA has to be applied as a result of degradation by nucleases. Similarly, the use of eukaryotic histones, synthetic peptides, or peptide nucleic acids may be limited by high production costs. We have demonstrated a biotechnologically feasible and economical approach for gene delivery using the histone-like protein from the hyperthermostable eubacterium Thermotoga maritima, TmHU as an efficient gene transfer reagent. HU can be easily isolated from recombinant Escherichia coli, is extraordinarily stable, and protects dsDNA from thermal denaturation. This study demonstrates its use as an inexpensive tool for gene delivery.

3T3 Cells↗
PubMed2000

[Second carcinomas in cancers of the mouth cavity, pharynx and larynx. Clinical, histopathologic and cell kinetic findings].

BACKGROUND: The mortality because of malicious tumours of the oral cavity, of the pharynx and of the larynx has considerably increased in the Federal Republic of Germany during the last two decades. The prognosis not only shows a high ratio of recidivations and formation of metastases, but also a typical field canceration. There is a high rate of incidence of multiple primary, resp. secondary tumours that may occur synchronously or metachronously. Up to now we have learnt only little about the mechanisms concerning the development of tumours and their spread on the cellular molecular level. METHOD: The subject of the present retrospective study was the analysis of patients suffering from an epithelioma of the oral cavity, the pharynx and the larynx and the following secondary carcinomatas. The control group were patients suffering from primary tumours of the same location and subsequent recidivation or metachronous metastasis. By determination of the degree of malignity and keratinisation of the DNA ploidy, of the immunohistological expression of p53 and the immunohistological proliferation marker MIB1 conclusions had to be drawn with regard to the biological behaviour of tumours. RESULTS: The evaluation of the clinical parameters of the 122 patients on the whole revealed a clear increase of new disease as well as a shifting to the younger age within the last five years. Surprisingly, most common were secondary tumours in case of larynx carcinomatas. Patients suffering from secondary tumours show a bad prognosis, however, their maximum survival does not differ considerably from that of patients suffering from recidivations, resp. metastases. Because of the early diagnosis of the secondary carcinomatas the prognosis will depend on the primary carcinoma in most of the cases. The prognosis data indicate that independently from the fact whether there is a primary or a subsequent tumour, the therapy to be applied can only be a combined therapy consisting of operation and ray-therapy. The present examinations confirm reports with regard to disturbance of the p53 regulation that also play an important role in case of the head-neck area. The parallel analysis of MIB1 as a proliferation marker showed in case of the primary carcinomatas a correlation of positive p53-immunocolour with moderate and strong proliferation. Tumours in the hypopharynx and larynx showed a significantly smaller proliferation than that of the oral cavity and oropharynx. In case of the primary and secondary tumours the proliferation is more common in case of the G3-tumours. CONCLUSIONS: The in total modest differences between the primary and secondary carcinoma with regard to the DNA-ploidy; the proliferation and the p53-expression presumably originate in their formation within the scope of a so-called field canceration. Because of the field canceration supposed for the mucous membranes of the upper aerodigestive tract, the check-ups of these patients performed in regular intervals must not be limited in any case to the area of the primary tumour. They will have to consider the entire visible area of the upper respiratory and esophageal tract.

Adult↗
PubMed1999

The HU protein from Thermotoga maritima: recombinant expression, purification and physicochemical characterization of an extremely hyperthermophilic DNA-binding protein.

The histone-like protein TmHU from the hyperthermophilic eubacterium Thermotoga maritima was cloned, expressed to high levels in Escherichia coli, and purified to homogeneity by heat precipitation and cation exchange chromatography. CD spectroscopical studies with secondary structure analysis as well as comparative modeling demonstrate that the dimeric TmHU has a tertiary structure similar to other homologous HU proteins. The Tm of the protein was determined to be 96 degrees C, and thermal unfolding is nearly completely reversible. Surface plasmon resonance measurements for TmHU show that the protein binds to DNA in a highly cooperative manner, with a KD of 73 nM and a Hill coefficient of 7.6 for a 56 bp DNA fragment. It is demonstrated that TmHU is capable to increase the melting point of a synthetic, double-stranded DNA (poly[d(A-T)]) by 47 degrees C, thus suggesting that DNA stabilization may be a major function of this protein in hyperthermophiles. The significant in vitro protection of double-helical DNA may be useful for biotechnological applications.

Allosteric Site↗
PubMed1999

[Functional esophageal scintigraphy (99mTc-DTPA)1.2. Presentation of a method for diagnosis of effective deglutition in patients with oral and hypopharyngeal tumors].

BACKGROUND: Today more than 60% of 65-year-olds complain of dysphagia or odynophagia. The aim of this study was to use esophageal scintigraphy as a means of estimating quantitative, reproducible, and comparable parameters of the swallowing ability in patients with tumors of the oropharynx and hypopharynx before and after surgery. Another group of patients suffering from larynx tumors was also examined prior to and following laryngectomy. METHODS: Fifteen male patients with T3/4 tumors of the oropharynx or hypopharynx, which were dissected followed by plastic surgery with a radialis flap, were examined before and after surgery. Esophageal scintigraphy was performed in 10 patients in this age group with T3/4 larynx tumors. The mean transit time (MTT in seconds) and clearance (in%) were the parameters evaluated. Condensed images were determined by averaging. Analog Polaroid images were also obtained. RESULTS: The 15 patients who underwent radialis flap surgery as a reconstructive measure showed a 60% improvement in the ability to swallow. Four of the 10 patients showed an obvious postoperative improvement in the ability to swallow as determined by clearance. With respect to the mean transit time, 2 cases out of 10 showed an improvement in the swallowing process. CONCLUSIONS: In patients who underwent reconstructive radialis flap surgery, it was possible to reestablish the continuity of the orohypopharynx, which is a prerequisite for the restoration of the swallowing facilitation. As a result one can expect an improvement in swallowing kinetics postoperatively. The patients who underwent laryngectomy required adaptation time to learn how to swallow under altered anatomical conditions. The primary reason for this is the altered pressure in the hypopharynx. Esophageal scintigraphy provides easily comparable parameters that serve as an ideal method for the objective determination of the ability to swallow in patients with these tumors. This method is neither poorly tolerated nor invasive and compared to other methods is a less costly alternative for examining the swallowing process.

Aged↗
PubMed1998

Structure determination of the Ras-binding domain of the Ral-specific guanine nucleotide exchange factor Rlf.

Ral-specific guanine nucleotide exchange factors RalGDS, Rgl, and Rlf have been suggested to function as intermediates between Ras and Ral pathways by being able to bind Ras proteins through their C-terminal Ras-binding domains (RBD). The RBDs of RalGDS and of the Ser/Thr kinase c-Raf-1 have been shown to have the same tertiary structure. In contrast to the RBDs of Raf and RalGDS, which bind either Ras or Rap with high affinity, Rlf-RBD has a similar affinity for both GTP-binding proteins. To be able to compare these RBDs on a structural level, we have solved the three-dimensional structure of Rlf-RBD by NMR spectroscopy. The overall tertiary structure of Rlf-RBD shows the betabetaalphabetabetaalphabeta-fold of the ubiquitin superfamily and is very similar to that of RalGDS-RBD. The binding interface of Rlf-RBD to Ras was mapped using chemical shift analysis and indicated a binding mode similar to that in the case of Rap.Raf-RBD. However, comparison of the putatively interacting regions revealed structural differences which are proposed to be responsible for the different substrate affinities of Rlf-, RalGDS-, and Raf-RBD.

Amino Acid Sequence↗
PubMed1995

[Surgical therapy of oropharyngeal carcinoma within the scope of interdisciplinary tumor surgery].

BACKGROUND: The results of the surgical therapy of patients with extensive squamous cell carcinoma of the oropharynx and their lymph node metastasis, postoperative follow-up, and rehabilitation depend on the collaboration between ear, nose, and throat surgeons and maxillofacial surgeons. Modern reconstruction techniques permit single-session surgical treatment with a reduced period of hospitalization. The most important therapeutic aim is to improve patient well-being. PATIENTS: Over a period of two years, 45 patients underwent the same surgical procedure. These patients were all in stages III or IV of their disease. RESULTS: This procedure consists of a temporary lateral osteotomy of the mandible with or without resection of the mandible, to provide broad exposure of the tumor of the oropharynx. Apart from the broad exposure, the advantage of this surgical method lies in simple reconstruction using a pedicled and microanastomosed flap. Internal fixation with six and four-hole titanium plates is a reliable method for restoring the stability of the mandible. In six patients, complications occurred in connection with the plate fixation. In four patients, we observed osteomyelitis of the fragment fissure or sequestration. Plate fracture and pseudarthrosis occurred in one patient each. CONCLUSIONS: In our clinical experience, the microvascular anastomosed radial flap proved to be the ideal free soft tissue transplant. One of its primary advantages is its plasticity and hence good post-therapeutic functional results. The jejunal flap has become less significant them the radial flap; the advantage of mucous membrane transfer is lost after radiation and a corresponding postoperative interval. In patients with large, voluminous defects, the use of myocutaneous flaps, especially from the latissimus dorsi, is still justified.

Adult↗
PubMed1994

[Determination of prognosis-relevant factors in patients with hypo- or oropharyngeal carcinoma].

The influence of pathomorphological parameters (keratinization, grading, nucleolar organizer region (NOR) counts, automatic analysis of micrographs) on prognosis was determined for 284 patients with carcinomas of the oropharynx or hypopharynx. Keratinization was found to have no influence on prognosis. Histopathological grading and automatic analysis of micrographs with mark 22 were seen to be of major relevance. Patients with grading 3 were noted to have a poorer prognosis than those with gradings of 1 or 2. This latter finding was statistically significant. Although the absolute NOR counts had no influence on prognosis, they did show a statistically significant effect on the extent of lymphogenic formation of metastases. Cox regression analysis of clinical and pathomorphological parameters revealed that combination therapy, tumor grading, and mark 22 of automatic analysis of micrographs were important factors relevant to prognosis.

Biomarkers, Tumor↗
PubMed1993

Nucleolar organizer regions in carcinomas of the oropharynx and hypopharynx.

It is supposed that the nucleolar organizer regions (NORs), genes on which ribosomal RNA is coded, may contain information on the structure of the nucleolus and on nucleolar activity which permits discrimination between normal and neoplastic cells and their proliferation activity. In the present study, the histological sections of 144 patients with carcinomas of the oropharynx and hypopharynx were studied in a retrospective approach to determine the absolute NOR counts per 100 nuclei and investigate their influence on the prognosis and extent of lymphogenic formation of metastases. An absolute NOR count of 681 per 100 nuclei was found to give reliable discrimination between stage N0 or N1 carcinomas and stage N2 or N3 disease.

Cell Count↗