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Biomedical subjects

Alexander Hemprich

Publications and source records attributed to Alexander Hemprich.

11 recordsLinked to original sources
PubMed2007

Sentinel lymph node biopsy in squamous cell carcinomas of the lips and the oral cavity - a single center experience.

BACKGROUND AND OBJECTIVES: Despite the availability of initial data on sentinel lymph node biopsy (SLNB) in OSCC, its value in clinical practice remains unclear. The aim of this study is to evaluate the feasibility and potential of SLNB as a reliable staging procedure in early stage SCC of the lips and the oral mucosa. METHODS: From 2001 to 2004, 40 patients with early stage SCC of the lips and oral cavity were enrolled. The main inclusion criteria were: cN0 category by MRI and ultrasound, tumor category T1-T2, for certain sites also T3. Patients with positive SLN underwent MRND and/or radiation. Patients with negative SLN were monitored monthly. RESULTS: In eight patients, the SLN were positive. Two patients with negative SLN subsequently developed nodal disease (5% false negatives). Twenty-one patients have a follow-up longer than 24 months. Five patients died (one from nodal disease, one from local recurrence, and three from unrelated causes). One patient developed a second primary tumor, the remaining patients are free of disease. CONCLUSIONS: SLNB may contribute to more targeted lymph node dissection strategies. Further studies will have to ensure the safety of this procedure in comparison to selective neck dissection.

Adult↗
PubMed2006

Bone engineering with adipose tissue derived stromal cells.

INTRODUCTION: Tissue engineering offers the means for replacing or repairing diseased or damaged organs within the patient's body. This current study deals with the general differentiation potential of human adipose tissue derived stromal cells (ATSCs) into mesenchymal tissues and particularly into bone. MATERIAL AND METHODS: ATSCs were isolated and cultivated until the 3rd passage. Three different ways of mesenchymal differentiation (adipogenic, osteogenic, myogenic) were induced and analysed histologically (v. Kossa, Sudan III) and immunhistologically (alpha-actin, osteocalcin). Nine different cell cultures were analysed in terms of calcium deposition (donor's age dependend) in the cell matrix and release of alkaline phosphatase (AP) during the differentiation period. Three-dimensional osteogenic constructs, based on collagenous micro-particles were performed and analysed histologically. RESULTS: Effective differentiation of ATSCs into osteogenic, adipogenic and myogenic cells could be demonstrated in histological and immunohistological analyses. There was an increase of calcium deposition in the cell matrix of osteogenically differentiated ATSCs that did not show any correlation with the age of the donor. Two out of three three-dimensional constructs showed clear zones of mineralization (v. Kossa) in the area of osteocalcin-producing cells. CONCLUSION: Adipose tissue derived stromal cells are a promising source for tissue engineering with a clear potential to differentiate into adipogenic, osteogenic and myogenic cells. The osteogenic differentiation potential did not show any correlation to the age of the donors (calcium deposition, AP-activity). Three-dimensional osteogenic constructs could be established.

Adipogenesis↗
PubMed2006

Microvascular engineering in perfusion culture: immunohistochemistry and CLSM findings.

BACKGROUND: One of the most challenging problems in tissue engineering is the establishment of vascular supply. A possible approach might be the engineering of microvasculature in vitro and the supply by engineered feeder vessels. METHODS: An in vitro model for a small-diameter vessel was developed and made from adipose tissue stromal cells and human umbilical vein endothelial cells in a tube-like gelatine scaffold. The number of "branches" emerging from the central lumen and the morphology of the central lumen of the vessel equivalent were assessed after 16 days of either pulsatile perfusion culture or culture in rotating containers by evaluation of immunohistochemically stained sections (n = 6 pairs of cultures). Intramural capillary network formation was demonstrated in five experiments with confocal laser scanning microscopy. RESULTS: Perfused specimens showed a round or oval lumen lined by a single layer of endothelial cells, whereas following rotation culture the lumen tended to collapse. Confocal laser scanning microscopy showed more extended network formation in perfused specimens as compared to specimens after rotation culture. Partially highly interconnected capillary-like networks were imaged which showed orientation around the central lumen. Perfused specimens exhibited significantly more branches emerging from the central lumen. There were, however, hardly any capillary branches crossing the whole vessel wall. CONCLUSION: Pulsatile perfusion supports the development of vascular networks with physiological appearance. Advances in reactor development, acquisition of functional data and imaging procedures are however necessary in order to attain the ultimate goal of a fully functional engineered supplying vessel.

Adipose Tissue↗
PubMed2006

The functionally based Leipzig concept for the treatment of patients with cleft lip, alveolus and palate.

In the year 1994 the former GDR cleft centre was integrated into the Department of Maxillofacial and Facial Plastic Surgery of the University of Leipzig. The treatment scheme of functional surgery according to DELAIRE was introduced to this new cleft and craniofacial centre at the University of Leipzig. The interdisciplinary team of specialists meets twice a week during a cleft clinic and takes care of about 900 out-patients per year. In the last decade an average of 40-50 new patients (infants) were admitted for in-patient primary surgery. Lip repair with reconstruction of the perinasal and perioral muscle rings is performed in combination with a primary rhinoplasty at the age of 5-6 months. Hard and soft palate are closed in a one stage procedure before the end of the first year of life. The results at the age of 12 years demonstrate good facial proportions and speaking abilities in far more than 90% of all cases. This functionally based treatment of clefts of lip, alveolus and palate achieves a good outcome with a low number of operative procedures.

Age Factors↗
PubMed2006

Potential and limits of achieving neutral occlusion in patients with clefts of lip, alveolus and palate.

INTRODUCTION: Therapy of cleft patients aims to control bone growth and tooth development so as to ensure a secure occlusion with good function. This paper aims to uncover the potential and limits of achieving neutral occlusion in patients with clefts of lip, alveolus and palate. Two treatment approaches are presented and compared with respect to the best long-term results. PATIENTS AND METHODS: The first method implies occlusal rehabilitation using maximum intermaxillary orthodontic fixation with the Jasper Jumper. Thus, orthodontic dental-alveolar compensation of the anomaly is obtained. The second method represents orthognathic surgery to achieve ideal intermaxillary relations and a neutral occlusion. Two patients are described - one each for both treatment regimens. DISCUSSION: The methods presented are meant to illustrate possible options for sagittal jaw development/movement in patient management. Orthodontic treatment has to rely on cooperation with maxillofacial surgery to achieve a neutral occlusion. Optimal management is ensured by a combination of both orthodontic and maxillofacial therapy. The orthodontic and surgical techniques for managing unilateral or bilateral clefts are continuously being further developed. CONCLUSION: Although orthodontic treatment can achieve good neutral occlusion in some patients, there are limitations and surgical measures may become necessary.

Adolescent↗
PubMed2004

Investigation of caries prevalence in children with cleft lip, alveolus, and palate.

AIM: The purpose of this study was to assess the prevalence of dental caries in children with orofacial clefts. PATIENTS: A total of 623 children aged 6-16 years with cleft lip, alveolus, and palate were included in the study. They were compared with 47,646 schoolchildren from Leipzig (Germany). METHODS: This cross-sectional study used the standard dental indices dmf(t) and DMF(T) for clinical assessment. Children underwent a dental examination under standard conditions of seating and lighting in the out-patient department of paediatric dentistry as part of a regular checkup. RESULTS: The prevalence of caries was significantly higher in children with cleft lip, alveolus, and palate in permanent and deciduous teeth. CONCLUSION: These assessments not only provide a baseline for oral health parameters in young patients with clefts, but also underline the need for a more aggressive approach to the prevention of oral disease to optimize clinical outcome.

Adolescent↗
PubMed2004

PCR detection of human papillomavirus of the mucosa: comparison between MY09/11 and GP5+/6+ primer sets.

BACKGROUND AND OBJECTIVES: Human papillomaviruses (HPV) are the causal agent for the development of carcinomas in the cervix uteri and further pathological changes of the skin including mucosa, particularly warts, condylomas and dysplasias. Therefore, we investigated the efficacy of different consensus primers pairs for HPV detection by PCR using brushed samples from the oral cavity in comparison with samples from the cervix uteri. STUDY DESIGN: In the present study, we used two well-established sets of PCR primers in different combinations for the detection of HPV DNA in 106 non-invasive brush biopsy samples of the oral mucosa and 56 samples from the cervix uteri. Direct sequencing of PCR products in all cases determined HPV genotype and specificity. RESULTS: Overall, HPV was detected in 69 of 106 oral mucosa samples. HPV specific amplicons were obtained in 35.8% (N = 38) when using GP5+/6+ primers. The positivity rate was increased to 65.1% in a GP5+/6+ auto-nested PCR approach. In contrast, MY9/11 PCR and nested PCR with MY9/11 outer followed by GP5+/6+ inner primers yielded 2.2% and 16.1%, respectively. In gynaecological samples, PCR results were similar independent of the primer combination used. Thus, DNA quality and DNA content could be additional factors influencing the rate of positivity. CONCLUSION: For oral mucosa samples, auto-nested GP5+/6+ PCR is in our hands the most suitable approach for epidemiological studies because of its high sensitivity, high reliability and reproducibility as well as its relatively simple laboratory procedure.

Biopsy↗
PubMed2003

Earliest detection of oral cancer using non-invasive brush biopsy including DNA-image-cytometry: report on four cases.

OBJECTIVE: We describe four patients presenting early oral cancers, detected cytologically on non-invasive brush biopsies including DNA-image cytometry as an adjunctive method before histology on scalpel biopsies confirmed the evidence of malignancy. METHODS: Brush biopsies were performed and smears thereof investigated cytologically. After Feulgen restaining, DNA-measurements were performed using a DNA-Image-Cytometer. CASE REPORTS: Oral squamous cell carcinomas were diagnosed cytologically in macroscopically suspicious lesions and malignancy confirmed by DNA-cytometry. The initially performed scalpel biopsies did neither supply evidence of oral cancer nor of severe dysplasia. After at least one to 15 months the occurrence of cancer was finally proven histologically on a second scalpel biopsy each (three microinvasive and one in situ carcinoma). CONCLUSION: Non-invasive brush biopsies are a suitable instrument for early cytologic detection of cancer of the mouth. DNA-image-cytometry, as an adjunctive method, can be used to confirm the cytologic diagnosis or suspicion of cancer in patients with doubtful lesions (dysplasias). DNA-aneuploidy is a marker for (prospective) malignancy in smears of the oral cavity, which may detect malignancy months prior to histology. In future this method could be used as a mass screening tool in dentists practice.

Aged↗
PubMed2003

Diagnostic value of nucleolar organizer regions (AgNORs) in brush biopsies of suspicious lesions of the oral cavity.

OBJECTIVE: The aim of this retrospective study was to report on the diagnostic accuracy of AgNOR-analysis as an adjunctive diagnostic tool of conventional oral exfoliative cytology taken from suspicious lesions in our clinic. STUDY DESIGN: Cytological diagnoses obtained from brush biopsies of macroscopically suspicious lesions of the oral mucosa from 75 patients (final diagnoses: 53 histologically proven squamous cell carcinomas, 11 leukoplakias and other inflammatory oral lesions) and from 11 patients with normal mucosa as a negative control group were compared with histological and/or clinical follow-ups. Five smears were doubtful and seven suspicious for tumor cells in the cytologic report. Number of AgNOR's were counted in 100 squamous epithelial cell-nuclei per slide after silver-restaining. RESULTS: Sensitivity of our cytological diagnosis alone on oral smears for the detection of squamous carcinomas was 92.5%, specificity 100%, positive predictive value was 100% and negative 84.6%. The best cut-off value of the mean number of AgNOR dots per nucleus distinguishing benign from malignant cells was 4.8. The percentage of nuclei with more than three AgNORs had a cut-off level of 70%. Applying these methods to twelve doubtful or suspicious cytological diagnoses we were able to correctly establish the diagnosis of malignancy in ten cases of histologically proven cancers and to reveal benignity in two histologically proven cases. Thus we achieved a positive and negative predictive value of 100% each. CONCLUSIONS: Smears from brushings of visible oral lesions, if clinically considered as suspicious for cancer, are an easily practicable, non-invasive, painless, safe and accurate screening method for detection of oral cancerous lesions. We conclude that AgNOR-analysis may be a useful adjunct to other methods in routine cytological diagnosis of oral cancer that can help to solve cytologically suspicious or doubtful cases.

Adult↗
PubMed2002

Cytophotometrical and immunohistochemical analysis of soft palate muscles of children with isolated cleft palate and combined cleft lip and palate.

Palatal muscle biopsies from the cleft margin of children were subjected to cytophotometrical and immunohistochemical analysis. Muscle fiber types were classified according to the enzyme activity of myofibrillic adenosine triphosphatase, glycerol-3-phosphate-dehydrogenase and succinate dehydrogenase assessed cytophotometrically. Fiber type-related immunoreactivity of nitric oxide synthase (NOS) isoforms I, II, III, as a physiological modulator of skeletal muscle function, was related to the oxidative and glycolytic activity of the muscle fibers. Fast oxidative glycolytic fibers with high oxidative activity showed strong NOS I immunoreactivity, whereas fast glycolytic fibers with high glycolytic activity were stronger immunolabelled for NOS III. NOS II expression was similar in all fiber types. No differences in NOS immunoreactivity were found between the two investigated forms of deformity. Additionally to the usual skeletal muscle fiber types, a slow tonic fiber type was for the first time identified in cleft palate muscles. Comparison of two forms of cleft palate, isolated cleft palate and combined cleft lip and palate has shown decreased enzyme activities in muscle fibers of palatal muscles from combined cleft lip and palate. Fast oxidative glycolytic fibers were mainly effected. Cytophotometrical and immunohistochemical analysis indicated a depressed performance of the cleft palatal muscles from combined cleft lip and palate as a stronger deformity compared with isolated cleft palate.

Adenosine Triphosphatases↗