Biomedical subjects

T Reuther

Publications and source records attributed to T Reuther.

At least 19 recordsLinked to original sources

PubMed2006

[Effect of urea nail lacquer on nail quality. Clinical evaluation and biophysical measurements].

BACKGROUND: Urea is a well-known humectant. The aim of our study was to evaluate the in vivo effect of 10% urea lacquer on nail quality. METHODS: 60 healthy probands with brittle nails were included in a randomized, controlled study. The nail lacquer was applied once (n=30) or twice daily (n=30) on one hand for 28 days, while the other hand served as untreated control. Assessments included clinical evaluations and bioengineering measurements. RESULTS: Application of the nail lacquer was well-tolerated and led to a significant clinical improvement of nail surface morphology, nail plate consistency, reflection of the nail plate surface, appearance of the cuticle and the nail fold. Sonographic nail density was slightly increased. No relevant changes were found in nail thickness and transonychial water loss. CONCLUSIONS: Nail lacquer containing urea improves the cosmetic appearance of fingernails.

Adult↗

PubMed2006

[Oral squamous cell carcinoma Retrospective analysis of therapy results and prognosis by neoadjuvant, preoperative radio-chemotherapy].

We investigated the charts of 129 patients treated for oral squamous cell carcinoma (SCC) in the Department of Oral and Maxillofacial Surgery, University of Cologne, between 1995 and 2004. Only patients treated preoperatively with combined radio-chemotherapy (carboplatin/39.6 Gy) were included. The purpose of the present study was to show the therapeutic outcome and the survival rates for this regimen. The mean age of the patients was 56.6 years. Male patients outnumbered female patients by 3:1. The floor of the mouth was the most common location (48.1%), and three out of four tumours (76.7%) had a G2 grading, while 82.9% were keratinized. Grade T4 was most the common (53.4%), and all patients were operated after preoperative treatment. In 82.2% of the cases, there were no tumour cells detectable microscopically (R0). In 34.1% there were viable tumour cells in the cervical lymph nodes, whereas in 66.7% these cells were found in the primary tumour despite preoperative treatment. A total of 38.8% of patients showed a recurrence of SCC. Mean survival was 4.8 years and 5 year survival 46.6%. The overall survival time of the disease was significantly influenced by pT (P=0.004), pN (P>0.001), R0 resections (P=0.0002), viable tumour cells in lymph node metastasis (P=0.0001), viable tumour cells in the primary (P=0.0004) and recurrence of the disease (P>0.001). In comparison to the current literature, no improvements in prognosis and survival of oral squamous cell carcinoma could be observed.

Adult↗

PubMed2005

[Ampicillin and sulbactam concentrations in the irradiated mandible after oral squamous cell cancer].

INTRODUCTION: Radiation therapy of the oral and maxillo-facial region increases the risk of an infected osteoradionecrosis (IORN) which is a severe complication. Therefore, perioperative antibiotics for the prophylaxis of ORN is a standard in clinical oncology. The combination therapy of ampicillin and sulbactam (Unacid) promises a good therapeutic and prophylactic outcome. PATIENTS: We compared the concentration of Unacid in bone and blood specimens of 22 irradiated patients. All patients were irradiated with 39.6 Gy prior to surgery. The specimens were obtained during the operation 3 weeks after the end of the radiation therapy. RESULTS: The concentration of ampicillin/sulbactam in the blood was 124.9/64.5 microg/ml. The bone specimens showed a concentration of ampicillin/sulbactam of 5.54/1.21 microg/g. The concentration of the antibiotic in the bone was three to four times lower than in non-irradiated patients. Nevertheless, this concentration exceeds the minimum inhibitory concentration for bacteria in the oral cavity such as streptcoccae (MHK90<0.25 microg/ml) or staphylococcae (MHK90=0.12-2.0 microg/ml). CONCLUSIONS: The results of this study suggest, that Unacid is an effective antibiotic in the prophylaxis of ORN in irradiated patients with head and neck tumors.

Adult↗

PubMed2005

[Quality of life of patients with squamous cell carcinoma of the oral cavity].

OBJECTIVE: The aim of this study was to assess the changes in quality of life during and after treatment in patients with cancer of the oral cavity. PATIENTS AND METHODS: In the period between October 1999 and September 2000, 57 patients of the Department of Craniomaxillofacial Surgery, University of Cologne, underwent surgery, radiation therapy or the combination of both for the treatment of cancer of the oral cavity. Before, during and after the therapy their quality of life was measured with two psychometric scales. RESULTS: The average loss of quality of life in the female group was less than in the male group. Younger patients suffered more than older ones did. All patients had a loss of quality of life 3 months after the beginning of the therapy. The biggest decrease was in the group of patients treated with combined therapy, and the lowest loss in the radiated group. During the assessment period of 9 months, there were significant differences between all three groups. The size of the tumor did not show any influence on the reduction of quality of life. Patients with cancer of the tongue or maxilla showed more loss of quality of life than patients with tumors located in other regions of the oral cavity. CONCLUSION: Location of the tumor, age, gender of the patient, and type of therapy influenced the quality of life, while the size of the tumor did not.

Adult↗

PubMed2005

[Endosonographic imaging of tumor thickness in oral squamous cell cancer and its effect on the incidence of lymph node metastases].

BACKGROUND: The correlation between increasing tumor thickness and lymph node metastases as well as reduced survival in oral cancer has been proven by several studies. In most investigations the tumor thickness was assessed in histological sections. The aim of our prospective study was to assess tumor thickness in oral squamous cell carcinoma (OSCC) by intraoral ultrasonography and to evaluate the predictive value of tumor thickness for incidence of cervical lymph node involvement and survival. PATIENTS AND METHODS: A total of 64 patients with primary carcinomas of the oral cavity (stage I-IV) were included. Endosonographic assessment of patients was carried out using a 7.5-mHz probe (Hitachi EUP F334). The primary tumor could be visualized in all cases as a hypoechoic, sometimes irregular mass. RESULTS: The average tumor thickness in all tumors was 14+/-7 mm. The N+ patients showed a greater tumor thickness (15+/-7 mm) than N0 OSCCs with 12+/-6 mm (p =0.032, t -test). Less advanced T1/T2 carcinomas revealed a tumor thickness of 10+/-5 mm in contrast to T3/T4 carcinomas with 16+/-7 mm (p <0.001, t-test). The overall survival was reduced in patients with tumors thicker than 14 mm (48.9 versus 28.3 months, p =0,0102 log rank test). CONCLUSION: Although this technique facilitates the accurate assessment of tumor thickness in OSCC, only in less advanced tumors could endosonography provide additional information, since these tumors were not visible on CT or MRT scans. Nonetheless endosonography is a fast, cost-effective, and reliable technique for assessment of tumor extent in oral cancer.

Aged↗

PubMed2004

[Active ingredients in dermatocosmetics].

Modern skin care- and anti-aging preparations feature both advanced formulation concepts and active ingredients against skin aging. Most of these ingredients are based on the recent findings that in aging the balance between collagen synthesis and collagen fragmentation is altered. Environmental factors inducing oxidative stress as well as decreased estrogen levels during menopause are important factors leading to these changes in connective tissue metabolism. Thus the major targets of anti-aging ingredients are oxidative stress and collagen metabolism. Evaluation of the effects of most of these ingredients has not been completed so far. In general scientifically evaluated anti-aging preparations can viewed as supplementing effective sunscreens and maximized skin care.

Collagen↗

PubMed2003

Morphogenesis and proliferation in mono- and organotypic co-cultures of primary human periodontal ligament fibroblasts and alveolar bone cells.

Cells of the periodontal ligament and the alveolar bone lie in close vicinity in the periodontium. The goal of this study was to create an in vitro model to facilitate the study of the morphogenesis and proliferation of these two cell types under more in-vivo-like conditions. This was accomplished by the generation of organotypic co-cultures of primary human periodontal ligament fibroblasts (PDL) and alveolar bone cells (BC) and matched mono-cultures after 1, 2 and 3 weeks. Indirect immunofluorescence (IIF) for vimentin indicated that PDL cells exhibited sustained stratification only in the presence of BC cells, suggesting an important role for BCs in maintaining the stratification of PDL cells. In mono-cultures, only BC cells showed progressing stratification. They also displayed the most pronounced contraction of the cell culture matrix. Moreover, Ki-67 antigen detection by IIF revealed that these features coincided with cell proliferation localized on the matrix surface at the onset of cell stratification. These findings suggest that, in addition to proliferation, a further prerequisite for stratification may be cell migration. Furthermore, the maintained cell stratification, proliferation, and compartmentalization noted for PDL cells in organotypic co-cultures and BCs in mono-cultures can only be observed in a three-dimensional culture system. Thus, our system represents a novel experimental tool to further elucidate the underlying mechanisms of the growth and differentiation of PDL and bone tissue.

Bone and Bones↗

PubMed2003

Osteoradionecrosis of the jaws as a side effect of radiotherapy of head and neck tumour patients--a report of a thirty year retrospective review.

This retrospective study aimed to demonstrate the incidence and the aetiological factors involved in osteoradionecrosis (ORN) in a group of 830 head and neck tumour patients who received radiotherapy between 1969 and 1999. The data showed an over all incidence of 8.2% and a 3-fold higher incidence for men than for women. Osteoradionecrosis was most commonly located in the body of the mandible. Concerning the risk factors, a negative influence was shown for advanced tumours, segmental resections of the mandible and pre-/post-radiation tooth extractions. Tooth extractions were found to be responsible for 50% of all cases. The osteoradionecroses were observed significantly earlier in patients who received pre-surgical radiotherapy than those who received post-surgical radiotherapy. Combined pre-surgical radio- and chemotherapy significantly hastened the appearance of osteoradionecrosis compared to pre-surgical radiotherapy alone. Only 40% of patients with osteoradionecrosis could be healed completely by means of surgery and antibiotic medication. Hyperbaric oxygenation (HBO) therapy was performed only in individual cases. The data suggest that osteoradionecrosis has a multifactorial aetiology. Therefore, a very close follow-up of tumour patients and a strict prophylactic management are required.

Adult↗

PubMed2003

Hohenheimer Consensus Talk. Oxidative and premature skin ageing.

To elucidate the scientific state of the art with respect to the role of nutrition in skin ageing, nine experts from different disciplines discussed the role of micronutrients on 'oxidative and premature skin ageing'. In this 25th Hohenheim Consensus Meeting, 13 questions were discussed and, based on published valid data, answered by mutual agreement. The consensus answers achieved during the meeting are justified by a scientific background text. The importance of in vitro and in vivo models regarding oxidative and premature skin ageing was critically evaluated. There was a special focus on prevention and intervention of skin ageing with nutrition. Finally, the paper summarizes the scientific background from different areas related to oxidative and premature skin ageing.

Animals↗

PubMed2002

[Retrospective analysis of facial fractures related to falls in 260 Japanese patients].

OBJECTIVE: Numerous epidemiological studies concerning fall-related injuries have been performed in the geriatric and orthopedic field to clarify the relation between the type of fall and fracture patterns. Although falls are a common cause of facial fractures, there is no study describing these relations. This study thus investigates the relationship between the type of fall and fracture pattern. MATERIALS AND METHODS: We analyzed 260 patients with fall-related facial fractures treated between 1995 and 2000 at the First Department of Oral and Maxillofacial Surgery, Osaka University Dental Hospital, Japan. These patients were classified into two groups: (1) those who suffered fractures by a fall from a standing position or lower and (2) those who suffered fractures by a fall from a level higher than the standing position. RESULTS: Fractures caused by falling from a standing position or lower was more common in older patients, especially in women beyond 70 years. The localization of mandibular fractures was not significantly different between the two groups. However, a high incidence of midface fractures was observed in the patients who fell from a higher position. These patients tended to suffer from central midface or dislocated fractures. CONCLUSION: The results were consistent with recent orthopedic studies, which suggest a relation between fractures in old patients and osteoporosis. A strong force caused by falls from a high position tends to act on the high portion of the midface. Our classification based on the height of the falls was able to demonstrate clearly the relation between etiological factors and fracture patterns. Therefore, it seemed reasonable to analyze patients treated in the Department of Oral and Maxillofacial Surgery, Heidelberg University, Germany, according to the same classification in order to compare both collectives.

Accidental Falls↗

PubMed2002

Do we alter ultraviolet sensitivity in vivo with stratum corneum rehydration? A pilot study and review of the literature.

BACKGROUND: Numerous therapeutic schemes recommend topical administration of emollients immediately prior to ultraviolet (UV) B therapy. The rationale behind the clinical improvement is a presumed enhancement of UV transmission through the epidermis. Originating from this clinical observation, there has been some concern as to whether a well-hydrated skin in general might be more susceptible to actinic damage. OBJECTIVES: To investigate whether rehydration of healthy skin causes an altered UVB sensitivity in vivo. METHODS: We determined minimal erythema doses (MEDs) and erythema sum scores (ESSs) after differential rehydration of the skin in 10 healthy volunteers. In each subject six UVB phototests were performed after pretreatment with five different emulsifying ointments (unguentum emulsificans and dilutions with 30, 50, 70 and 90% aqua purificans) plus a negative control. In vivo evaluation of stratum corneum hydration was performed by measurement of electrical capacitance. RESULTS: The results of this randomized, double-blind in vivo study indicated that rehydration of normal stratum corneum with the emulsifying ointments tested did not result in a significantly altered sensitivity to the erythematous effects of UVB irradiation (no significant differences in MED and ESS). Furthermore, there was no correlation between measured stratum corneum hydration and the erythema response of healthy skin. CONCLUSIONS: Although many schemes recommend the administration of emollients prior to UV therapy, there have also been calls for caution, as an uncritical application may interfere with such treatment. We showed that the emulsifying ointments tested exhibited no photoprotective potential and thus are suitable for the pretreatment of psoriasis prior to phototherapy. It has long been discussed whether the effects of emollient pretreatment on response to UV occur only in psoriatic skin or also in healthy skin. Our results indicated that stratum corneum rehydration did not result in a significantly increased erythema response of healthy skin to UVB exposure. With regard to the use of rehydrating cosmetics in everyday life, the outcome of our pilot study is reassuring, as we could not confirm with our experimental design that well-hydrated healthy skin is more prone to actinic damage.

Adult↗

PubMed2001

Comparison of the in vivo efficiency of photofrin II-, mTHPC-, mTHPC-PEG- and mTHPCnPEG-mediated PDT in a human xenografted head and neck carcinoma.

BACKGROUND AND OBJECTIVE: One of the approaches to enhance the selectivity and efficiency of photodynamic therapy (PDT) was the conjugation of the photosensitizer meta-tetrahydroxyphenylchlorin (mTHPC) to the water-soluble polymer polyethylene glycol (PEG). Several studies have demonstrated that mTHPC-PEG has a higher selectivity and a longer circulating half-life than free mTHPC, whereas no in vivo effect of this benefit could be seen. STUDY DESIGN/MATERIALS AND METHODS: In a model of RAG-2-mice bearing a human oral squamous cell carcinoma xenograft (XF 354), the in vivo efficiency assessed as growth retardation or remission caused by Photofrin II and free mTHPC was compared with mTHPC coupled in two different ways to polyethylene glycol (PEG). One hundred and fourty-nine female RAG-2-mice were randomised into one control group and 13 therapy groups. Treatment parameters were adapted from those routinely applied in animal studies. RESULTS: Photofrin II-mediated PDT and mTHPC-mediated PDT were both in vivo highly effective, whereas mTHPC induced less scars. The in vivo results after mTHPC-PEG-mediated PDT were disappointing, whereas the effectiveness of mTHPCnPEG-mediated PDT, a newly coupled macromolecular photosensitizer, were promising. CONCLUSIONS: These results demonstrated the impact of the method of linkage between the photoactive agent mTHPC and polyethylene glycol (PEG) upon the in vivo effectiveness. mTHPC and mTHPCnPEG are promising photosensitizers for the future, especially for the cosmetic treatment needs of head and neck surgery.

Animals↗

PubMed2001

[Clinical effectiveness of m-THPC-PEG in a new xenogenic animal tumor model for human squamous epithelial carcinomas].

BACKGROUND: Animal tumor models are still essential for the development of new medication and therapy concepts. For the field of oropharyngeal cancer only few reliable xenogeneic tumor models are available. In a two-part experiment a new xenogeneic tumor model was established. PART 1 OF THE STUDY: The growth rates of two different tumor cell lines were compared in the RAG-2 mouse, the SCID mouse and the Swiss nude mouse. Cells from a lymph-node metastasis of an oral squamous cell carcinoma (XF-354) showed a better growth rate and clearer histology than cells from a primary squamous cell carcinoma of the floor of the mouth (UM-SCC-14C). The tumor growth rate was highest on the RAG-2 mouse, followed by the SCID mouse. The Swiss nude mouse showed no tumor growth at all. The combination of the XF-354 tumor cell line and the RAG-2 mouse was the most successful, with a tumor growth rate of 95%. The animal model is very reliable and robust and enables manipulations under anaesthesia outside the sterile barrier for up to 30 min. The single steps for cell cultivation and tumor implantation are described and discussed in detail. PART 2 OF THE STUDY: The second part of this study investigated the clinical efficacy of the macromolecular linked photosensitizer--mTHPC-PEG compared with the free photosensitizer mTHPC. Macromolecular linked photosensitizers have theoretical advantages owing to their pharmacokinetics and tumor selectivity. For the animal experiment, the photosensitizer mTHPC showed significantly better results than the macromolecular linked photosensitizer mTHPC-PEG. The reasons for these in vivo results are discussed in detail.

Animals↗

PubMed2001

Effects of low dose ultraviolet A-1 phototherapy on morphea.

AIM: The effects of low dose ultraviolet A-1 (UVA-1) phototherapy on different clinical stages of morphea (localized scleroderma) were analyzed in this case study. Based on these data, the different types of phototherapy described in the literature and currently used for treatment of morphea are compared. METHODS: Three patients with severe plaque type morphea in different stages were studied: one patient with late-stage lesions having stable sclerotic plaques; another patient with active inflammatory lesions; and a third patient with late-stage lesions associated with overlying lichen sclerosus et atrophicus (LSA). The treatment given was low dose UVA-1 phototherapy with single doses of 20 J/cm2 administered four times a week for 6 weeks, and once a week for another 6 weeks. RESULTS: Following UVA-1 phototherapy, the sclerotic plaques resolved, leaving smooth and soft tanned skin with normal structure, consistency and folding capability. In morphea with overlying LSA the elastic fibers did not completely return to the superficial papillary dermis despite the clinical clearance of both morphea and LSA. These data suggest that low dose UVA-1 phototherapy may improve, but not completely reverse, the histopathological changes of LSA. No side effects were observed during or after treatment. CONCLUSION: Our observations show in three patients that low-dose UVA-1 phototherapy is highly effective for treatment of all stages of morphea, including early inflammatory and late sclerotic lesions, and morphea with overlying lichen sclerosus et atrophicus. Because of its safety and efficacy, low dose UVA-1 phototherapy appears to be the treatment modality of choice.

Adult↗

PubMed2000

Local oxygen content in the skin is increased in chronic venous incompetence.

In skin lesions of chronic venous incompetence (CVI) transcutaneous oxygen pressure (tcpO(2)) at the ankle is often reduced. However, in some CVI patients the tcpO(2) during suprasystolic occlusion remains significantly higher than in healthy subjects. The aim of the present study was to investigate which kind of CVI patients develop this phenomenon and whether the higher tcpO(2) during occlusion is caused by a smaller oxygen consumption of the skin or by an increased local oxygen content. The oxygen consumption of the skin was measured by the pO(2) decrease (DeltatcpO(2)/Deltat) after stopping the arterial oxygen supply when the hemoglobin was saturated by oxygen inhalation, i.e., at tcpO(2) values above 120-130 mmHg. By multiplying the tcpO(2) with the mean oxygen solubility coefficient of the skin the content of physically dissolved oxygen is obtained. The decrease of tcpO(2) in the 55- to 45-mmHg range indicates the consumption of oxygen physically dissolved and chemically bound to hemoglobin. It gave a parameter for estimating the local hemoglobin content of the skin. These values and the minimal tcpO(2) after a 5-min arterial occlusion were measured in 14 healthy subjects, in 13 patients with varicose veins, but no skin lesions, in 10 patients with CVI lesions like white atrophy and lipodermatosclerosis and in 16 CVI patients with open venous ulcers. During suprasystolic occlusion tcpO(2) at the ankle remained significantly higher in CVI patients with skin lesions than in the healthy control subjects (25.6 +/- 18.9 versus 8.0 +/- 7.0 mmHg). The steepness of the tcpO(2) decrease caused by cutaneous oxygen consumption in healthy subjects was not significantly different from the CVI patients. In contrast, the decrease of tcpO(2) at the ankle between 55 and 45 mmHg was 1.9 +/- 2.0 mmHg/s in the control group and 0.7 +/- 0.5 mmHg/s in the group with open venous ulcers. These results indicate a higher hemoglobin content in the skin of the CVI patients than in healthy subjects. Obviously, the hemoglobin bound oxygen content in the skin of CVI patients is increased. Thus, a lack of oxygen is unlikely to be the primary reason for the development of skin lesions in CVI.

Administration, Inhalation↗

PubMed1999

PUVA-bath photochemotherapy (PUVA-soak therapy) of recalcitrant dermatoses of the palms and soles.

PUVA-bath therapy has proven to avoid many side effects associated with oral 8-methoxypsoralen (8-MOP) treatment. In order to investigate the effectiveness of topical PUVA-bath therapy (PUVA-soak therapy) on chronic palmoplantar dermatoses, 30 patients with plaque-type psoriasis, pustular psoriasis, endogenous eczema, dyshidrotic eczema and hyperkeratotic dermatitis of the palms and soles were treated over 8 weeks with PUVA-soak using 8-MOP. No additional treatment except skin moisturising cream such as unguentum emulsificans aquosum was used during the study period. The single UVA-doses applied ranged from 0.3 to 3.0 J/cm2 (mean single dose of 1.8 J/cm2), with a mean cumulative dose of 48.6 J/cm2 per patient. Altogether 26 of 30 patients responded well within 8 weeks of treatment with 63% of all patients showing a complete remission and 23% showing considerable improvement, as shown by flattening of plaques, decreased scaling and erythema, as well as decreased vesicle and pustule formation. The condition responding best to our therapy was palmoplantar psoriasis followed by atopic eczema. Hyperkeratotic dermatitis displayed the poorest responding rates in this study. Unwanted side effects such as erythema, pain, blistering or patchy hyperpigmentation were not observed in any of the patients. We conclude that PUVA-soak therapy can be highly efficient in the treatment of palmoplantar dermatoses, especially in the management of palmoplantar psoriasis.

Administration, Cutaneous↗

PubMed1998

[Bleomycin-induced PSS-like pseudoscleroderma. Case report and review of the literature].

Although the association between administration of the antitumor agent bleomycin and the development of cutaneous fibrosis is established, there are only a small number of cases of bleomycin-induced scleroderma described in the literature. We report the development of generalised scleroderma with wide spread hyperpigmentation in a 52-year-old male patient, who received a total dose of 360 mg bleomycin in combination with cisplatin and etoposid for therapy of a malignant testicular seminoma. The clinical cutaneous alterations as well as the histological findings were indistinguishable from those encountered in progressive systemic sclerosis (PSS). In contrast to PSS however, Raynaud's phenomenon, cutaneous calcinosis, teleangiectasia, arthritis and involvement of additional organs were all absent. PSS-typical auto-antibodies were negative. Even 18 months after discontinuation of the drug and treatment with UVA1 phototherapy (3-4 times per week with 20 J/cm2) as well as physiotherapy, the skin changes had still not resolved. Based on our case and a detailed review of the literature, we discuss characteristics of bleomycin-induced scleroderma including pathogenesis, treatment modalities and course.

Antibiotics, Antineoplastic↗

PubMed1998

Kinetics of photosensitivity in bath-PUVA photochemotherapy.

BACKGROUND: Bath-PUVA is used to treat a variety of dermatoses. However, the kinetics of 8-methoxypsoralen during treatment are not completely clarified. OBJECTIVE: The purpose of this study was to investigate the intensity of the phototoxic response and the persistence of phototoxicity after bath-PUVA. METHODS: Twelve volunteers were exposed to UVA doses ranging from 0.5 to 40 J/cm2 from 10 to 240 minutes after bath-PUVA treatment. The resulting phototoxic response of the skin was determined. RESULTS: Irradiation 10 minutes after the psoralen bath led to the lowest assessed minimal phototoxic dose (MPD) of 1.42 J/cm2 (mean, SD +/- 0.29). Thereafter, the MPD increased significantly and sharply every hour. At 4 hours after the psoralen bath, UVA doses up to 40 J/cm2 failed to induce any phototoxic erythema (MPD). CONCLUSION: For optimal effects, UVA irradiation has to be administered immediately after the psoralen bath; no restrictive behavior is necessary after bath-PUVA treatment.

Adult↗