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Biomedical subjects

W Steiner

Publications and source records attributed to W Steiner.

At least 19 recordsLinked to original sources
PubMed2005

[Voice function and quality of life--patients with laryngeal carcinoma following minimal-invasive laser surgery and function voice rehabilitation].

BACKGROUND: Quality of life is a relevant criterion for therapeutical outcome in laryngeal carcinoma patients. The aim of this study was to assess the self-related complaints in quality of life and functional outcome of voice among persons who had undergone laryngeal cancer surgery. METHODS: The examination took place 67 months (SD 34.8) after the last surgery, on average and finishing of 60 therapy sessions (median). First a measurement with the Goettinger Hoarseness Diagram (GHD) was carried out. Next the subjects answered self-reported standardized questionnaires for life quality in oncological patients on the same day: EORTC-QLQ-C30 and 3 scales of the German Fragebogen zur Lebenszufriedenheit (health-related fulfillment, fulfillment with work/occupation, fulfillment with social environment). For disease-related symptoms of different head and neck domains the EORTC-HandN35 was administered. SUBJECTS: Forty-four patients (37 males, 7 females) who were treated primarily with minimal invasive laser surgery followed by functional voice rehabilitation (Goettinger Konzept). Mean age: 60.1 (SD 9.7) years. RESULTS: The acoustic voice quality according to the GHD showed a significant correlation with self-reported "Somatic Functioning" (- 0.32, p = 0.04) and "Social Functioning" (- 0.38, p = 0.01) in the EORTC-QLQ-C30 as well as with the symptom scales "Speech" (0.45, p < 0.0024) resp. "Social Contact" (0.45, p = 0.0021) in the EORTC-HandN35. Also hoarseness and health-related fulfillment (- 0.36, p = 0.02) as well as fulfillment with work/occupation (- 0.33, p = 0.03) correlated significantly. On the other hand, there was no significant association between the GHD and the assessment of global quality of life. CONCLUSION: Postoperative phonatory reductions in patients with laser surgically treated laryngeal carcinoma have only a slight influence on overall quality of life. The same is true for the GHD. Assessment of self-reported quality of life in recommendation of oncologic treatment may not be able to replace the objective findings, but may be useful to detect other problems, e.g. psychosocial.

Aged↗
PubMed2005

Results on quantitative trait loci for flushing date in oaks can be transferred to different segregating progenies.

Flushing date (bud burst) is one of the most important traits for the adaptation to different environments and climates in the temperate zone. Because of their wide geographic distribution, Quercus robur L. and Q. petraea (Matt.) Liebl. are suitable as model plants to study the genetic basis of bud burst. QTLs (Quantitative Trait Loci) with comparatively large effects have been mapped in a former study in a Q. robur x Q. robur full-sib family (French cross). In the present study, we performed a Bulked Segregant Analysis (BSA) in the F (1) progeny comprising 144 seedlings derived from a cross between a single Q. robur tree as common seed parent and five different pollen donors both from Q. robur and Q. petraea (Q. robur x Q. spp., Diekholzen crosses). In addition, markers linked to two bud burst QTLs with comparably strong effect in the above-mentioned full-sib family (French cross) were tested for their association with bud burst in the Q. robur x Q. spp. (Diekholzen) progeny. Using three microsatellite markers as anchor points, we could map QTLs on linkage group 7 and on linkage group 2, together explaining 16.2 % of the total phenotypic variance (PVE) in 1999 and 38.1 % in 2003. Out of 10 markers that segregated in both mapping progenies, four markers including the two microsatellite markers, showed a significant effect on bud burst in both materials. At microsatellite loci ssrQpZAG1/5 (linkage group 7) and ssrQpZAG119 (linkage group 2) alleles associated with early (allele 166 bp in ssrQpZAG1/5) and late bud burst (allele 57 bp in ssrQpZAG119) in the Q. robur x Q. robur full-sib family (French cross) showed a highly significant association with the same polarity of the effect in the Q. robur x Q. spp. (Diekholzen) progeny. The usefulness of these markers for marker-assisted selection in full-sib and half-sib families is discussed.

Genetic Linkage↗
PubMed2003

Accelerated process development for protease production in continuous multi-stage cultures.

A fermentation process was developed and optimized for the production of a specific protease from Bacillus licheniformis PWD-1. Media formulations were constructed and crucial environmental parameters were optimized to enhance growth and product formation. Process dynamics of substrate consumption, biomass-, product-, as well as by-product formation were determined under controlled conditions in a bioreactor. Using kinetic data from batch- and continuous-culture experiments, a fed-batch process was developed producing proteolytic activities 10 times those found during regular batch culture. In one stage continuous stirred tank culture protease formation was completely decoupled from sporulation. Shift experiments in one-stage continuous cultures led to the development of a two-stage continuous stirred tank fermentation process using optimized conditions for growth in the first stage and protease formation in the second stage. Accordingly, the basis for a continuous production of the enzyme on a pilot scale was accomplished.

Bacillus↗
PubMed2003

Highly thermostable amylase and pullulanase of the extreme thermophilic eubacterium Rhodothermus marinus: production and partial characterization.

Five strains of the extreme thermophilic Rhodothermus marinus were screened for the production of amylolytic and pullulytic activities. The culture medium for the selected strain, R. marinus ITI 990, was optimized using central composite designs for enhanced enzyme production. The optimized medium containing 1.5 gl(-1) of maltose and 8.3 gl(-1) of yeast extract yielded amylase, pullulanase and alpha-glucosidase activities of 45, 33 and 2.1 nkatml(-1), respectively. Among the various carbon sources tested, maltose was most effective for the formation of these enzymes, followed by soluble maize starch, glycogen and pullulan. The crude amylase and pullulanase showed maximum activities at pH 6.5-7.0, and 85 and 80 degrees C, respectively. At 85 degrees C amylase and pullulanase had half lives of 3 h and 30 min, respectively.

Amylases↗
PubMed2002

[Are inpatient rehabilitation or ambulatory physical therapy of patients with musculoskeletal problems effective and are patients referred to proper treatment?].

The aim of the present study was to investigate the effectiveness of an inpatient rehabilitation program and outpatient physiotherapy, respectively. Moreover, we wanted to know whether the referral to these two treatment paths was appropriate with regard to the patient's initial health status. According to the referring physician's indication patients with health problems in the cervical, lumbar spine, arm or leg were treated by an inpatient rehabilitation program or by outpatient physiotherapy. These two consecutively recruited patient cohorts were then compared. Those patients treated by the inpatient rehabilitation program differed from the outpatient group with regard to the initial health status and to age. Patients with musculoskeletal problems, who underwent an inpatient rehabilitation program, showed a significantly worse health and functional status than the outpatient group. Therefore, it can be concluded that the indication towards inpatient rehabilitation or outpatient physiotherapy was correctly given by the referring physicians. Patients treated by outpatient physiotherapy did also show a reduced health and functional status in comparison to the average population. Both types of treatment led to statistically significant and clinically relevant improvement of both the health and functional status in all patient groups.

Adult↗
PubMed2002

Acetopyruvate hydrolase production by Pseudomonas putida O1--optimization of batch and fed-batch fermentations.

The main objective of this work was the optimization of the production of the beta-ketolase, acetopyruvate hydrolase, from Pseudomonas putida O1. Orcinol was used as an inducer for enzyme production. The growth medium was optimized in two steps. In the first step, screening for optimal glucose concentration was performed. In the second step, a central composite design was used to optimize carbon and nitrogen sources in the medium. After this optimization procedure, a medium was obtained which produced seven times more biomass than the initial medium. Acetopyruvate hydrolase enzyme production was optimized by determining the optimal time of feed and amount of orcinol, using statistical methods. In a subsequent step, the maximal orcinol-degradation rate was determined. The results obtained were used to find an optimal feeding profile for enzyme production. By using the optimized fed-batch process, acetopyruvate hydrolase activity was enhanced from 10 units l(-1)to 400 units l(-1), in comparison with previously reported fermentation experiments. Productivity could even be increased by a factor of 75, to a value of 20 units l(-1 )h(-1).

Fermentation↗
PubMed2002

Decolorization of textile dyes by laccases from a newly isolated strain of Trametes modesta.

Four ligninolytic fungi, Trametes modesta, Trametes hirsuta, Trametes versicolor and Sclerotium rolfsii, were compared for their ability to produce laccases. The fungal laccases were screened for their ability to decolorize eight synthetic dyes (anthraquinone, azo, indigo and triarylmethane). The decolorization rate depended both on the source of the enzyme preparation and on the structure of the dye. Based on laccase production and dye decolorizing ability, T. modesta was selected for further studies. All the tested dyes were decolorized by the T. modesta laccase most efficiently under acid conditions (pH 3-6) but the optimum pH for decolorization of the individual dye varied. The decolorization rate of this laccase increased with the rise in temperature to 50-60 degrees C. The decolorization efficiency of T. modesta laccase was improved remarkably in the presence of mediators like 1-hydroxybenzotriazole and 2-methoxyphenothiazine.

Color↗
PubMed2002

Production of laccase by a newly isolated strain of Trametes modesta.

The effects of the carbon and nitrogen sources, initial pH and incubation temperature on laccase production by Trametes modesta were evaluated using the one-factor-at-a-time method. The final optimisation was done using a central composite design resulting in a four-fold increase of the laccase activity to 178 nkat ml(-1). Response-surface analysis showed that 7.34 g l(-1) wheat bran, 0.87 g l(-1) glucose, 2.9 g l(-1) yeast extract, 0.25 g l(-1) ammonium chloride, an initial pH of 6.95 and an incubation temperature of 30.26 degrees C were the optimal conditions for laccase production. Laccase produced by T. modesta was fully active at pH 4 and at 50 degrees C. The laccase was very stable at pH 4.5 and at 40 degrees C but half-lives decreased to 120 and 125 min at higher temperature (60 degrees C) and lower pH (pH 3).

Biotechnology↗
PubMed2001

Reinforcement of genetic coherence in a two-locus model.

BACKGROUND: In order to maintain populations as units of reproduction and thus enable anagenetic evolution, genetic factors must exist which prevent continuing reproductive separation or enhance reproductive contact. This evolutionary principle is called genetic coherence and it marks the often ignored counterpart of cladistic evolution. Possibilities of the evolution of genetic coherence are studied with the help of a two-locus model with two alleles at each locus. The locus at which viability selection takes place is also the one that controls the fusion of gametes. The second locus acts on the first by modifying the control of the fusion probabilities. It thus acts as a mating modifier whereas the first locus plays the role of the object of selection and mating. Genetic coherence is enhanced by modifications which confer higher probabilities of fusion to heterotypic gametic combinations (resulting in heterozygous zygotes) at the object locus. RESULTS: It is shown that mutants at the mating modifier locus, which increase heterotypic fusions but do not lower the homotpyic fusions relative to the resident allele at the object locus, generally replace the resident allele. Since heterozygote advantage at the object locus is a necessary condition for this result to hold true, reinforcement of genetic coherence can be claimed for this case. If the homotypic fusions are lowered, complex situations may arise which may favor or disfavor the mutant depending on initial frequencies and recombination rates. To allow for a generalized analysis including alternative models of genetic coherence as well as the estimation of its degrees in real populations, an operational concept for the measurement of this degree is developed. The resulting index is applied to the interpretation of data from crossing experiments in Alnus species designed to detect incompatibility relations.

Alleles↗
PubMed2001

Organ preservation by transoral laser microsurgery in piriform sinus carcinoma.

OBJECTIVE: To determine the effectiveness of organ-preserving CO2 laser microsurgery for the treatment of piriform sinus carcinoma. METHODS: A retrospective review of 129 previously untreated patients undergoing CO2 laser microsurgery for the treatment of squamous cell carcinomas of the piriform sinus from 1981 to December 1996 was undertaken. The intention was complete tumor removal by preserving functionally important structures of the larynx. Distribution of tumors (Union Internationale Contre le Cancer/American Joint Committee on Cancer, 1992) was 24 cases with pT1, 74 with pT2, 17 with pT3, and 14 with pT4 disease. Node status was positive in 68% of patients. Seventy-five percent of patients had stage III or IV disease. Forty-two percent of the patients were treated solely with surgery, and 58% had surgery and postoperative radiotherapy. The median follow-up interval was 44 months. RESULTS: Eighty-seven percent of patients were controlled locally. Neck recurrences occurred in 14.0% of patients, metachronous distant metastases with locoregional control in 6.2%, and second primary tumors in 18.6%. Twenty percent of patients died of TNM-related deaths. The 5-year overall Kaplan-Meier survival rate was 71% for stages I and II and 47% for stages III and IV disease; the 5-year recurrence-free survival rates were 95% and 69%, respectively. CONCLUSION: A comparatively low local recurrence rate, a high recurrence-free survival rate, and the avoidance of laryngectomy favor function-preserving surgery of piriform sinus carcinomas.

Adult↗
PubMed2001

Efficacy of selective neck dissection: a review of 503 cases of elective and therapeutic treatment of the neck in squamous cell carcinoma of the upper aerodigestive tract.

OBJECTIVE: The purpose of this study was to evaluate the efficacy of selective neck dissection (SND) in elective and therapeutic treatment of the neck. METHODS: A retrospective review was undertaken of 503 previously untreated patients undergoing 711 SNDs as a part of initial therapy for squamous cell carcinoma of the larynx, oral cavity, oropharynx, and hypopharynx from August 1986 to June 1997 at a single institution. Lymph nodes were pathologically negative in 249 and positive in 254 patients. Postoperative radiotherapy was given to 14.5% of the node-negative and 62.2% of the node-positive patients. The median follow-up interval was 41 months. RESULTS: The 3-year regional recurrence rates estimated according to Kaplan-Meier were as follows: pN0, 4.7%; pN1, 4.9%; pN2, 12.1%. A comparison of recurrence rates with respect to the extent of neck disease and postoperative radiotherapy demonstrated a tendency to an improved regional control in irradiated patients with one metastasis and a distinctly improved regional control in patients with multiple metastases or metastases with extracapsular spread. CONCLUSION: The results achieved with SND compare favorably with the results reported for modified radical neck dissection. The application of SND might be extended to more advanced neck disease.

Carcinoma, Squamous Cell↗
PubMed2001

Responsiveness of the WOMAC osteoarthritis index as compared with the SF-36 in patients with osteoarthritis of the legs undergoing a comprehensive rehabilitation intervention.

OBJECTIVE: To compare the responsiveness of the condition-specific Western Ontario and McMaster Universities osteoarthritis (OA) index (WOMAC) and the generic Short Form-36 (SF-36) in patients with OA of the legs undergoing a comprehensive inpatient rehabilitation intervention. METHODS: A prospective follow up study of consecutively referred inpatients of a rehabilitation clinic was made. The patients included fulfilled the American College of Rheumatology criteria for knee or hip OA and underwent both passive and, particularly, active physical therapy for three to four weeks. Responsiveness assessment was performed using the standardised response mean (SRM), effect size, and Guyatt's responsiveness statistic between admission and discharge (end of rehabilitation) and then again between admission and three months later. For pain and function the SRMs were stratified by sex and OA joint. Effects were tested by the t test and SRMs of different scales were compared by the jack knife test. RESULTS: At the three month follow up, complete data were obtained for 223 patients. In general, the three responsiveness statistics showed a similar order of responsiveness. For both instruments, the pain scales were more responsive than the function scales. The responsiveness of the pain scale of both instruments was comparable (SRM=0.723 for WOMAC and SRM=0.528 for SF-36 at the end of rehabilitation; SRM=0.377 for WOMAC and SRM=0.468 for SF-36 at the three month follow up). In the measurement of function, the WOMAC was significantly more responsive than the SF-36 (SRMs, end of rehabilitation: 0.628 v 0.249; three month follow up: 0.235 v -0.001). Responsiveness tended to be higher in women and in knee OA than in men and hip OA. CONCLUSIONS: Both instruments, the WOMAC and the SF-36, capture improvement in pain in patients undergoing comprehensive inpatient rehabilitation intervention. Functional improvement can be detected better by the WOMAC than by the SF-36. All the other scales of both instruments were more weakly responsive.

Adult↗
PubMed2000

Optimisation of culture medium and conditions for alpha-l-Arabinofuranosidase production by the extreme thermophilic eubacterium Rhodothermus marinus.

The culture medium for Rhodothermus marinus was optimised on a shake-flask scale by using statistical factorial designs for enhanced production of a highly thermostable alpha-L-arabinofuranosidase (AFase). The medium containing 3.6 g/l birch wood xylan and 8.2 g/l yeast extract yielded a maximum of 110 nkat/ml AFase activity together with 125 nkat/ml xylanase and 65 nkat/ml beta-xylosidase activity. In addition, low levels of beta-mannanase (30 nkat/ml), alpha-galactosidase (0.2 nkat/ml), beta-galactosidase (0.3 nkat/ml), endoglucanase (5 nkat/ml) and beta-glucosidase (30 nkat/ml) were detected in the culture filtrate. Among the various carbon sources tested, birchwood xylan was most effective for the formation of AFase and xylanase activities, followed by oat spelt and beechwood xylans, and xylan-rich lignocelluoses (e.g., starch-free sugar beet pulp and wheat bran). Constitutive levels of enzyme activities were detected when the bacterium was grown on other polysaccharides and low-molecular-weight carbohydrates. A fermentation in a 5-l fermenter (3-l working volume) using the optimised medium yielded 60 nkat/ml AFase associated with 65 nkat/ml xylanase and 35 nkat/ml beta-xylosidase activities. The crude AFase displayed optimal activity between pH 5.5 and 7 and at 85 degrees C. It had half-lives of 8.3 h at 85 degrees C and 17 min at 90 degrees C. It showed high stability between pH 5 and 9 (24 h at 65 degrees C). The combined use of AFase-rich xylanase and mannanase from R. marinus in the prebleaching of softwood kraft pulp gave a brightness increase of 1.8% ISO. To our knowledge, this is the first report on the production of a high AFase activity by an extreme thermophilic bacterium and this enzyme is the most thermostable AFase reported so far.

Journal Article↗
PubMed2000

Simultaneous detection of different glycosidase activities by 19F NMR spectroscopy.

A fast method for the simultaneous detection of different glycosidolytic activities in commercially available enzyme preparations and crude culture filtrates was found in using, as substrate, a mixture of different glycosyl fluorides and 19F NMR spectroscopy as a screening technique. Accompanying studies regarding the hydrolytic stability of these fluorides in various buffer systems, as well as conditions of their long-term storage, were carried out. A simple procedure for the preparation of beta-D-mannopyranosyl fluoride in gram quantities is given.

Fluorine↗
PubMed2000

Transglycosylation reactions with a crude culture filtrate from Thermoascus aurantiacus.

Some characteristics of regioselectivity and acceptor tolerance in transglycosylation reactions, catalysed by a crude culture filtrate from Thermoascus aurantiacus, were examined by employing methanol and monosaccharides as acceptors. When beta-D-mannopyranosyl fluoride was employed as the donor, the anomeric configuration of the newly formed bond was found to depend on the structure of the acceptor used.

Ascomycota↗
PubMed2000

Simultaneous production of high activities of thermostable endoglucanase and beta-glucosidase by the wild thermophilic fungus Thermoascus aurantiacus.

The culture-medium composition was optimised, on a shake-flask scale, for simultaneous production of high activities of endoglucanase and beta-glucosidase by Thermoascus aurantiacus using statistical factorial designs. The optimised medium containing 40.2 g l(-1) Solka Floc as the carbon source and 9 g l(-1) soymeal as the organic nitrogen source yielded 1130 nkat ml(-1) endoglucanase and 116 nkat ml(-1) beta-glucosidase activities after 264 h as shake cultures. In addition, good levels of beta-xylanase (3479 nkat ml(-1)) and low levels of filter-paper cellulase, beta-xylosidase, alpha-L-arabinofuranosidase, beta-mannanase, beta-mannosidase, alpha-galactosidase and beta-galactosidase were detected. Batch fermentation in a 5-1 laboratory fermentor using the optimised medium allowed the production of 940 nkat ml(-1) endoglucanase and 102 nkat ml(-1) beta-glucosidase in 192 h. Endoglucanase and beta-glucosidase showed optimum activity at pH 4.5 and pH 5, respectively, and they displayed optimum activity at 75 degrees C. Endoglucanase and beta-glucosidase showed good stability at pH values 4-8 and 4-7, respectively, after a prolonged incubation (48 h at 50 degrees C). Endoglucanase had half-lives of 98 h at 70 degrees C and 4.1 h at 75 degrees C, while beta-glucosidase had half-lives of 23.5 h at 70 degrees C and 1.7 h at 75 degrees C. Alkali-treated bagasse, steam-treated wheat straw, Solka floc and Sigmacell 50 were 66, 48.5, 33.5 and 14.4% hydrolysed by a crude enzyme complex of T. aurantiacus in 50 h.

Ascomycota↗
PubMed2000

Thermolabile xylanase of the Antarctic yeast Cryptococcus adeliae: production and properties.

Xylanase production by the Antarctic psychrophilic yeast Cryptococcus adeliae was increased 4.3 fold by optimizing the culture medium composition using statistical designs. The optimized medium containing 24.2 g l(-1) xylan and 10.2 g l(-1) yeast extract and having an initial pH of 7.5 yielded xylanase activity at 400 nkat (nanokatal) ml(-1) after 168-h shake culture at 4 degrees C. In addition, very little endoglucanase, beta-mannanase, beta-xylosidase, beta-glucosidase, alpha-L-arabinofuranosidase, and no filter paper cellulase activities were detected. Among 12 carbon sources tested, maximum xylanase activity was induced by xylan, followed by lignocelluloses such as steamed wheat straw and alkali-treated bagasse. The level of enzyme activity produced on other carbon sources appeared to be constitutive. Among the complex organic nitrogen sources tested, the xylanase activity was most enhanced by yeast extract, followed by soymeal, Pharmamedia (cotton seed protein), and Alburex (potato protein). A batch culture at 10 degrees C in a 5-1 fermenter (3.5-1 working volume) using the optimized medium gave 385 nkat at 111 h of cultivation. The crude xylanase showed optimal activity at pH 5.0-5.5 and good stability at pH 4-9 (21 h at 4 degrees C). Although the enzyme was maximally active at 45 degrees - 50 degrees C, it appeared very thermolabile, showing a half-life of 78 min at 35 degrees C. At 40 degrees - 50 degrees C, it lost 71%-95% activity within 5 min. This is the first report on the production as well as on the properties of thermolabile xylanase produced by an Antarctic yeast.

Antarctic Regions↗