PubMed Health⌕ Search

Biomedical subjects

G Wenzel

Publications and source records attributed to G Wenzel.

At least 19 recordsLinked to original sources
PubMed2007

Molecular mapping of resistance genes to tan spot [Pyrenophora tritici-repentis race 1] in synthetic wheat lines.

Synthetic wheat lines (2n = 6x = 42, AABBDD), which are amphiploids developed from the hybrid between tetraploid wheat (Triticum turgidum L., 2n = 4x = 28, AABB) and Aegilops tauschii Coss. (2n = 2x = 14, DD), are important sources of resistance against tan spot of wheat caused by Pyrenophora tritici-repentis. In the present study, inheritance, allelism and genetic linkage analysis in synthetic wheat lines have been carried out. Segregation analysis of the phenotypic and molecular data in F(2:3) populations of CS/XX41, CS/XX45, and CS/XX110 has revealed a 1:2:1 segregation ratio indicating that resistance of tan spot in these synthetic lines is controlled by a single gene. Allelism tests detected no segregation for susceptibility among F(1) and F(2) plants derived from intercrosses of the resistance lines XX41, XX45 and XX110 indicating that the genes are either allelic or tightly linked. Linkage analysis using SSR markers showed that all the three genes: tsn3a in XX41, Tsn3b in XX45 and tsn3c in XX110 are clustered in the region around Xgwm2a, located on the short arm of chromosome 3D. The linked markers and genetic relationship of these genes will greatly facilitate their use in wheat breeding and deployment of cultivars resistant to tan spot.

Alleles↗
PubMed2005

Relief of reflux symptoms after endoscopic gastroplication may be associated with reduced esophageal Acid sensitivity: a pilot study.

BACKGROUND AND STUDY AIMS: Although the new endoscopic techniques for the treatment of gastroesophageal reflux disease (GERD) lead to marked clinical benefit, the underlying mechanism of this is unknown. MATERIALS AND METHODS: In this prospective study, the effect of endoscopic gastroplication was investigated in six patients with GERD, who were assessed before and 4 weeks after treatment. The effect on reflux symptoms, quality of life, proton pump inhibitor (PPI) consumption, reflux esophagitis, acid exposure, esophageal motility, lower esophageal sphincter pressure (LESP), and gastric emptying was measured. Esophageal acid sensitivity before and after treatment was investigated using a standardized acid provocation test, and compared with that of six age- and sex-matched healthy controls. RESULTS: Significant clinical benefit and discontinuation of PPI consumption after gastroplication was seen. Among the objectively measured parameters, only acid exposure was significantly reduced and gastric emptying significantly delayed. However, acid exposure remained pathologically high. Esophageal acid sensitivity was significantly reduced. The induction of heartburn and/or pain was abolished in four patients after gastroplication. In two patients the intensity of heartburn/pain was significantly reduced by 40 % or 60 %, and the time to provoke heartburn/pain significantly prolonged by 40% or 100%. CONCLUSION: These preliminary data suggest that the decrease of esophageal sensitivity to acid after endoscopic gastroplication is part of the mechanism responsible for the reduction of reflux symptoms.

Adult↗
PubMed2005

Comparative analysis of Phytophthora infestans induced gene expression in potato cultivars with different levels of resistance.

Differential gene expression was analyzed after infection with Phytophthora infestans in six potato cultivars with different levels of resistance to late blight. To verify the infection of the potato leaflets, the amount of phytopathogen mRNA within the plant material was quantified by real-time quantitative PCR. The expression of 182 genes selected from two subtracted cDNA libraries was studied with cDNA array hybridization using RNA from non-infected and infected potato leaflets. Gene up- and down-regulation were clearly detectable in all cultivars 72 h post inoculation. Gene expression patterns in susceptible cultivars differed from those in potato varieties with a higher level of resistance. In general, a stronger gene induction was observed in the susceptible cultivars compared to the moderately to highly resistant potato varieties. Five genes with the highest homology to stress and/or defence-related genes were induced specifically in the susceptible cultivars. Four genes responded to pathogen attack independently of the level of resistance of the cultivar used, and three genes were repressed in infected tissue of most cultivars. Even in the absence of P. infestans infection, six genes showed higher expression levels in the somewhat resistant cultivars Bettina and Matilda. Possible reasons for the different levels of gene expression are discussed.

Down-Regulation↗
PubMed2004

Development and validation of a PCR-based marker assay for negative selection of the HMW glutenin allele Glu-B1-1d (Bx-6) in wheat.

Polymorphisms between the coding sequences of high-molecular-weight (HMW) glutenin x-type genes at the Glu-1 locus were used to amplify Glu-1B x-type-specific PCR fragments. PCR analysis in a wheat cultivar subset carrying different Glu-1B x-type alleles resulted in PCR fragments that differed in size for Glu-B1-1d (B-x6) and non -Glu-B1-1d (B-x6) genotypes. Subsequent sequencing analysis revealed a 15-bp in-frame insertion in the coding regions of all Glu-B1-1d (B-x6) genotypes which allowed the development of a B-x6-specific PCR assay for high-throughput allele sizing by ion-pair reversed-phase high-performance liquid chromatography. The assay was validated in a set of 86 German wheat cultivars, and genotyping data unequivocally verified the presence of HMW glutenin subunits GLU-B1-1D (Bx-6) + GLU-B1-2A (By-8) by means of sodium dodecyl sulphate-polyacrylamide gel electrophoresis. These results demonstrate that the PCR assay can be applied for the detection and negative selection of the 'poor breadmaking quality' Glu-B1-1d (B-x6) alleles in wheat breeding programs.

Alleles↗
PubMed2004

Localization of a novel recessive powdery mildew resistance gene from common wheat line RD30 in the terminal region of chromosome 7AL.

Segregation analysis of resistance to powdery mildew in a F(2) progeny from the cross Chinese Spring (CS) x TA2682c revealed the inheritance of a dominant and a recessive powdery mildew resistance gene. Selfing of susceptible F(2) individuals allowed the establishment of a mapping population segregating exclusively for the recessive resistance gene. The extracted resistant derivative showing full resistance to each of 11 wheat powdery mildew isolates was designated RD30. Amplified fragment length polymorphism (AFLP) analysis of bulked segregants from F(3)s showing the homozygous susceptible and resistant phenotypes revealed an AFLP marker that was associated with the recessive resistance gene in repulsion phase. Following the assignment of this AFLP marker to wheat chromosome 7A by means of CS nullitetrasomics, an inspection of simple sequence repeat (SSR) loci evenly spaced along chromosome 7A showed that the recessive resistance gene maps to the distal region of chromosome 7AL. On the basis of its close linkage to the Pm1 locus, as inferred from connecting partial genetic maps of 7AL of populations CS x TA2682c and CS x Virest ( Pm1e), and its unique disease response pattern, the recessive resistance gene in RD30 was considered to be novel and tentatively designated mlRD30.

Ascomycota↗
PubMed2004

QTL mapping for resistance against non-parasitic leaf spots in a spring barley doubled haploid population.

Phenotypic variability for resistance against non-parasitic leaf spots (NPLS) has been observed between varieties. For the genetic characterization of NPLS resistance, a population with 430 doubled haploid (DH) lines was developed from the cross between the NPLS-resistant Hordeum vulgare breeding line IPZ24727 and the NPLS-sensitive barley cultivar Barke. A molecular map was constructed based on 164 AFLPs, 30 SSRs and one STS marker derived from the mlo gene. Field trials were performed over four environments in which NPLS and other agronomic traits were assessed. Estimates of genotypic variance were highly significant for NPLS. Moreover, no transgression was found for the trait. Quantitative trait loci (QTLs) for NPLS resistance were mapped in the DH population on chromosomes 1H, 4H, and 7H, with the most important effect on chromosome 4H. The QTLs for NPLS explained together 39% of the phenotypic and 49% of the genotypic variance, thereby showing additive gene action. Consequently, marker-assisted selection for improving NPLS resistance is possible.

Agriculture↗
PubMed2002

Production of haploids from anther culture of banana [Musa balbisiana (BB)].

We report here, for the first time, the production of haploid plants of banana Musa balbisiana (BB). Callus was induced from anthers in which the majority of the microspores were at the uninucleate stage. The frequency of callus induction was 77%. Callus proliferation usually preceded embryo formation. About 8% of the anthers developed androgenic embryos. Of the 147 plantlets obtained, 41 were haploids (n=x=11). The frequency of haploid production depended on genotypes used: 18 haploid plants were produced from genotype Pisang klutuk, 12 from Pisang batu, seven from Pisang klutuk wulung and four from Tani. The frequency of regeneration was 1.1%, which was based on the total number of anthers cultured. Diploid plants (2n=2x=22) were also observed in the regenerated plants. The haploid banana plants that were developed will be important material for the improvement of banana through breeding programmes.

Culture Techniques↗
PubMed2002

[Universal newborn hearing screening program in Würzburg. Experience with more than 4000 newborns and the influence of non-pathological factors on the test results].

BACKGROUND: The BERAphon(R) method employing a special headphone and the time-course step-stimulus algorithm offers a quick and reliable tool for universal hearing screening in newborns. An ABR-based universal newborn hearing screening program has been established in Würzburg since August, 1997. Until August 2001, 4115 newborns have undergone primary and/or control-screening with the BERAphon(R). The validity of this method was further examined by testing the effects of non-pathological factors such as gender, age, Apgar score, pH value of the umbilical cord, head circumference and duration of pregnancy on the ABR wave V latency in 415 infants. RESULTS: Out of 3930 infants who were primary screened, 27 infants were diagnosed to have hearing loss. Furthermore, hearing loss was detected in 35 out of 185 infants referred for control screening. Non-pathological factors showed a minor effect on the test results. Apgar score, gender or chronological age did not have any significant effects on the latency of wave V. Duration of pregnancy, pH value of the umbilical cord or head circumference showed a significant but weak correlation with wave V latency. CONCLUSIONS: Only non-pathological factors related to maturation had a minor effect on ABR measurements using the time-course-step-stimulus algorithm. The BERAphon(R) method has proven to be a reliable, robust method giving information related to the hearing threshold and accordingly can be used reliably for hearing screening in newborn infants.

Audiometry, Evoked Response↗
PubMed2001

Effects of QiGong on brain function.

QiGong is an ancient and widely practiced Chinese meditation exercise. We studied the effects of QiGong on brain function with modern neuromonitoring tools in two subjects. In a male QiGong master (extremely trained practitioner), the technique induced reproducible changes in transcranial Doppler sonography, EEG, stimulus-induced 40 Hz oscillations, and near-infrared spectroscopy findings. Similar effects were seen after the application of multimodal stimuli and when the master concentrated on intense imagined stimuli (e.g. 22.2% increase in mean blood flow velocity (vm) in the posterior cerebral artery, and a simultaneous 23.1% decrease of vm in the middle cerebral artery). Similar effects were seen in the female subject. Neuromonitoring during QiGong appears able to objectify accompanied cerebral modulations surrounding this old Chinese meditation exercise.

Acoustic Stimulation↗
PubMed2000

Chromosomal location of AFLP markers in common wheat utilizing nulli-tetrasomic stocks.

Amplified fragment length polymorphism (AFLP) markers with a total of 256 EcoRI + ANN - MseI + CNN primer combinations were investigated employing the common wheat cultivar Triticum aestivum 'Chinese Spring.' On average, 103 fragments per primer combination were amplified, ranging from a maximum of 226 fragments to a minimum of 18 fragments. The primer combinations E + AAA - M + CNN and E + ATT - M + CNN produced very few distinct fragments. By using 15 randomly chosen EcoRI + ANN - MseI + CNN primer combinations, 928 AFLP markers were allocated to wheat chromosomes, of which 131 were assigned to specific chromosome arms. These AFLP markers were locus-specific and randomly distributed on the different chromosomes. In addition, 6 and 41 AFLP markers were simultaneously absent in two nulli-tetrasomics (NTs) of both homoeologous and non-homoeologous groups, respectively, whereas additional fragments were detected in N1BT1A, N5AT5D, and N6BT6A lines.

Chromosome Mapping↗
PubMed1997

A new tongue advancement technique for sleep-disordered breathing: side effects and efficacy.

We examined the efficacy and the acceptance of an oral device (SnorEx) causing a forward displacement of the tongue for the treatment of sleep-disordered breathing (SDB). Twenty-three consecutive subjects with SDB were investigated. Noncompliance (NC) of use of the oral appliance was observed in 74% (17 of 23) of the subjects. NC patients were characterized by unacceptable local side effects of the prosthesis, lacking improvement of indicators of daytime well-being, and a missing reduction of the respiratory disturbance index (RDI). The device was tolerated without side effects in 26% (6 of 23) of the subjects. In these compliant (C) subjects the RDI, EDS, and snoring improved significantly (p < 0.05) compared with baseline values. After 6 mo using the device, five of the six C patients were still using it. We conclude that the high rate of noncompliance and the low efficacy of the SnorEx prosthesis preclude large-scale use of this treatment modality in patients with SDB and snoring since the local side effects are the principal cause of NC. No useful predictive parameter of treatment compliance or treatment success was found. Thus, this dental appliance should be prescribed only for selected patients failing other treatment modalities seen by an experienced sleep-disorders specialist.

Dental Prosthesis↗
PubMed1997

[Optical stimulation method (Snore-Stop) and tongue retainer (Snore-Master) without relevance in therapy of obstructive sleep apnea and snoring].

Recently intra- und extraoral devices are increasingly used in order to treat obstructive sleep apnea and snoring. We examined the value of an optically stimulating system ("eye-cover", Snore-Stop) and a tongue-retainer (Snore-Master) as treatment of the obstructive sleep apnoe or snoring. In case of the eye-cover is a microphone integrated, which detects acoustic signals (e.g. snoring). After detection of snoring optical stimuli are generated in front of the eyes. This is intended to induce an arousal of the patient, without awaking him, causing a change of body position and this reduces the snoring or apneas. For the examination of the eye-cover in 26 patients (23 men, 55.6 +/- 10.3 years) polygraphic studies were performed while sleeping one night with the eye-cover and one night without, respectively. Visual analogue scales (VAS) were used in order to measure quality of life and sleep and the adverse effects of the device. To examine the tongue-retainer 14 patients (13 men, aged 52.9 +/- 11.8 years) were measured polygraphically. Again the subjective scores were assessed using the VAS. The principle of the tongue-retainer is to create a hollow space in front of the teeth, in which the tongue is positioned. Fixation of the tongue in this ventral position is thought to enlarge the mesopharyngeal area in order to reduce the upper airway obstruction. For both devices the index of snoring, the apnea-hypopnea-index, the index of desaturation, the mean and minimal SaO2 and SaO2 < 90 % in % of the night did not change significantly. Furthermore the subjective perception of the patients concerning their quality of sleep and life did not change. Moreover, despite of an adequate adaptation-period the use of the tongue-retainer was associated with considerable adverse effects. Neither the eye-cover nor the tongue-retainer could improve the severity of obstructive sleep apnoe or snoring.

Adult↗
PubMed1997

[Bronchial hyperreactivity and nCPAP therapy].

In patients with obstructive sleep apnoea (OSA) nCPAP may irritate the mucous membranes of the upper airways. We investigated in this study whether nCPAP can induce bronchial hyperreactivity (BHR). Forty-one patients (33 men, mean age 52.6 years) were treated with nCPAP due to OSA. All of them were tested for BHR with histamine ("pari-provo-Test") before and six weeks after initiation of the nCPAP therapy. Thirty-five of the patients showed BHR neither before nor after the beginning of CPAP. Six patients developed a BHR of moderate degree (PD20: 50-100 micrograms) during the study; four of these six patients were not symptomatic. The two other patients complained about more colds than usual or about noctumal cough. Both of them received inhaled steroids and a moistening system. Nobody of the enrolled patients was obliged to finish CPAP therapy due to BHR. Four patients had already a BHR before nCPAP therapy began. Most of the patients did not acquire a BHR during the first 6 weeks after nCPAP therapy had started. A BHR bronchial may develop, but in the majority it remains without clinical relevance. In patients with a BHR and OSA, the benefits of nCPAP therapy excel the potential adverse effects.

Airway Resistance↗
PubMed1997

[Is SnorEx also ApneaEx? A study with a new intra-oral prosthesis as a form of therapy of obstructive sleep apnea syndrome].

UNLABELLED: In recent years different kinds of dental devices have been advocated for treating sleep apnoea. In this study we report on our results with a kind of prosthesis ("Snor-Ex", DEPITA, 29336 Nienhagen) designed to relieve upper airway obstruction in sleep in pulling forward the tongue by a truss pad positioned in the posterior area of the tongue. We performed the study to test the effectiveness of the device in reducing the number of obstructive events. PATIENTS: 23 patients with OSA (22 male, age: 53.7 +/- 8.6 years, Body mass index: 31.1 +/- 3.9 kg/m2, Apnoea index: 33.5 +/- 18.4, Respiratory disturbance index: 45.6 +/- 19.7, mean apnoea duration: 20.4 +/- 4.4 sec) were included. STUDY DESIGN: Before the study was started, polysomnography was performed and the OSA associated symptoms/claims were standardised with the help of visual analogue scales (VAS). The prosthesis were made by the dental laboratory. Between the 28th and 42nd day after beginning with the study the patients had to come to the hospital for control. The effect of the therapy was documented only by a further polysomnography in patients who could sleep for at least 2.5 hours with the prosthesis. The effects of the device on changing OSA-associated symptoms and snoring were reevaluated by the above mentioned VAS. During the control the patients were divided into non-responders (NR) and responders (R) according to the results. RESULTS: The NR prevail in the study with 75% (17/23). They are characterised by inacceptable loco-regional side effects of the prosthesis, missing improvement of the state of daytime wellbeing and constant obstructive events. Only 25% of the patients are R. They locally tolerated the prosthesis, which is the precondition for long-term therapy. The severity of OSA diminished. Snoring also diminished significantly. CONCLUSION: According to our results the insufficient acceptance and the low effectivity of the SnorEx-prosthesis preclude large-scale indication for OSA patients. The prosthesis should not be prescribed without contacting a sleep lab.

Adult↗
PubMed1997

[Changes in the time spent awake in obstructive sleep apnea and snoring--results of a pilot study].

Continuous positive airway pressure (CPAP) therapy reduces sleeping time per day and daytime sleepiness in obstructive sleep apnoea (OSA) and heavy snoring. Due to sleep fragmentation the OSA and heavy snoring are associated with a daytime sleepiness and increased necessity of sleep. In this pilot study the effect of CPAP-therapy on daytime sleepiness and sleep time during 24 hours were assessed in patients with OSA or heavy snoring (daytime sleepiness, none or slight apnoea with AHI < 10/h and benefit of CPAP). We studies 42 patients with OSA (AHI: 34.5 +/- 23.6) and 15 patients with heavy snoring: inclusion criteria: Patients with OSA (AHI > 10/h, ESS-Score > 8) and heavy snoring (AHI < 10/h, ESS-Score > 8) who were treated with nCPAP. Before and 2 months after initiation the CPAP-therapy all patients completed diary cards recording the sleeping time/day for 1 month; additionally they scored sleepiness using the Epworth sleepiness scale (ESS-score ranged from 0 to 24, the higher the score the worse the sleepiness) before and 2 months after initiation the CPAP-therapy. In the whole study population nCPAP-therapy reduced the sleeping time significantly by a mean period of 46 minutes per 24 hours (from 8.3 +/- 1.3 to 7.5 +/- 1.2 hours, p < 0.001) and improved the ESS score from 13.7 +/- 4.6 to 6.1 +/- 3.6 (p < 0.0001). In respect of the change of sleeping time/day and of the sleepiness score there was no significant difference between the OSA and heavy snoring group. With CPAP the AHI in OSA patients was reduced from 34.5 +/- 23.6/h to 3.2 +/- 3.2/h. Due to the improvement of sleep-related breathing disorders CPAP therapy reduced the mean sleeping time/day by approximately 10% and the daytime sleepiness score both in patients with OSA and heavy snoring compared to the pretreatment period.

Airway Obstruction↗
PubMed1995

Polyethylene glycol 4000 for slow transit constipation.

Slow transit constipation is notoriously difficult to treat. We tested whether polyethylene glycole 4000 (PEG) improves slow transit constipation. Eight female outpatients with symptoms of constipation and a colonic marker transit of more than 60 h were included (age 46 +/- 4y, duration of complaints 17 +/- 3y) in a randomised controlled cross-over study. During a 6-week placebo and 6-week PEG-phase (60g PEG/d) the following parameters were measured: 1. subjective well-being with respect to defeacation on a visual analogue scale (-8 cm very bad, +8 cm very good), 2. in the first 5 weeks of each phase, average dose of sodium picosulfate (prescribed as only allowed laxans, dose adjusted and protocolled on a diary by patient) 3. stool frequency, 4. colonic transit of radiopague polythene pellets in the last week of each phase (the use of laxative was strictly prohibited in this last week). Both subjective and objective parameters of colonic function improved significantly. Visual analog scale ratings improved from -4.65, [-8; 0.5] to 4.65, [-8; 7.5]cm (median, range) (p = 0.028), the self-administered dose of sodium picosulfate decreased from 4, [0; 37] to 0, [0; 11] drops per day (p = 0.028), stool frequency increased from 3.1, [1; 30] to 11, [2; 33] defeacations per week (p = 0.017), and total colonic transit decreased from 91, [67; 116] to 43 h, [17; 76]h (p = 0.017). In conclusion, PEG improves colonic function in patients with slow transit constipation subjectively and objectively. PEG should be considered as an additional option in patients refractory to established forms of treatment.

Adult↗
PubMed1993

[Alcohol-induced toxic hepatitis--a "free radical" associated disease. Lowering fatality by adjuvant antioxidant therapy].

Toxic liver diseases coincide with oxidative stress correlating positively with the seriousness of the course of disease. For the purpose of elucidating the pathogenic significance of an increased radical generation. 56 patients suffering from acute alcohol-toxic hepatitis of the clinical grade of seriousness B and C according to Child/Pugh were classified randomly into antioxidant subgroups (n = 31) and control groups (= 25). The basis therapy being identical, the patients of the antioxidant group received additionally 600 mg of D-alpha tocopherol per day, 200 micrograms of selenium and 12 mg of zinc. Due to the supplementation of antioxidants there were quicker significant changes in the concentration of bilirubin, malondialdehyde and of ammonia in the serum. In comparison with the control group the length of stay in hospital could be reduced by 6 days. In the control group the mortality rates amounted to 40% (10 of 25), in the antioxidant group to 6.5% (2 of 31). The results confirm the pathogenic significance of oxidative stress in alcohol-toxic liver disease because a distinct improvement of prognosis could be achieved by using a low-cost adjuvant antioxidant supplementation.

Adult↗