Biomedical subjects

E Kruse

Publications and source records attributed to E Kruse.

At least 19 recordsLinked to original sources

PubMed2001

Impaired expression of the plastidic ferrochelatase by antisense RNA synthesis leads to a necrotic phenotype of transformed tobacco plants.

Protoporphyrin IX is the last common intermediate of tetrapyrrole biosynthesis. The chelation of a Mg2+ ion by magnesium chelatase and of a ferrous ion by ferrochelatase directs protoporphyrin IX towards the formation of chlorophyll and heme, respectively. A full length cDNA clone encoding a ferrochelatase was identified from a Nicotiana tabacum cDNA library. The encoded protein consists of 497 amino acid residues with a molecular weight of 55.4 kDa. In vitro import of the protein into chloroplasts and its location in stroma and thylakoids confirm its close relationship to the previously described Arabidopsis thaliana plastid-located ferrochelatase (FeChII). A 1700-bp tobacco FeCh cDNA sequence was expressed in Nicotiana tabacum cv. Samsun NN under the control of the CaMV 35S promoter in antisense orientation allowing investigation into the consequences of selective reduction of the plastidic ferrochelatase activity for protoporphyrin IX channeling in chloroplasts and for interactions between plastidic and mitochondrial heme synthesis. Leaves of several transformants showed a reduced chlorophyll content and, during development, a light intensity-dependent formation of necrotic leaf lesions. In comparison with wild-type plants the total ferrochelatase activity was decreased in transgenic lines leading to an accumulation of photosensitizing protoporphyrin IX. Ferrochelatase activity was reduced only in plastids but not in mitochondria of transgenic plants. By means of the specifically diminished ferrochelatase activity consequences of the selective inhibition of protoheme formation for the intracellular supply of heme can be investigated in the future.

Cloning, Molecular↗

PubMed2001

[Unilateral hearing loss in childhood. An empirical analysis comparing bilateral hearing loss].

BACKGROUND: Unilateral cochlear hearing loss is considered as a risk factor for auditory, verbal-communicative, behavioral and academic development. An early diagnosis is therefore necessary. METHOD/PATIENTS: 182 consecutive patients with an age up to 10 years were diagnosed with permanent hearing loss in the mild to profound range in a defined 5-years-period (1.10.1994-30.9.1999) in the Pedaudiologic Outpatient Clinic of the University Göttingen. Fifty children (27.5%) had a unilateral hearing loss (30 sensorineural, 20 conductive caused by aural atresia with or without microtia), 132 a bilateral one. This paper presents the data of the consecutive series of the 30 sensorineural unilaterally hearing-impaired children (> 25 dB). RESULTS: A slight male predominance was present (53.3%). The left ear was affected in 43.3%, the right ear in 56.7%. In the majority of the cases the hearing loss was severe and profound. The hearing-impairments were diagnosed by the median age of 69.5 months and all aided by the median age of 70 months. The etiology remained unknown in 60 per cent of the cases. Hearing aid acceptance at the first follow-up (on average after 6 months) was found to be 79 per cent. CONCLUSIONS: The data suggest the relevance and necessity of a pedaudiometric prevention. They demonstrate the urgent necessity of a molecular genetic cause investigation. Recessive sensorineural hearing loss with onset in infancy may exist with no antecedent family history.

Child↗

PubMed2001

Effect of smoking reduction and cessation on cardiovascular risk factors.

This open study examined the effect of smoking reduction and smoking cessation on established cardiovascular risk factors. Fifty-eight healthy adult smokers (smoking >or=15 cigarettes/day for at least 3 years) were provided with nicotine nasal spray (to be used ad libitum) and asked to stop smoking. The primary goal during the first 8 weeks, however, was to reduce their daily smoking by at least 50%. Subjects were then followed for another 8 weeks; at this point, 33 participants had successfully stopped smoking. Cardiovascular risk factors including fibrinogen, hemoglobin, hematocrit, triglycerides, and cholesterol were measured at baseline and at 9 and 17 weeks. After 8 weeks of smoking reduction, the mean number of cigarettes smoked per day had decreased from 21.5 +/- 0.6 (baseline) to 10.8 +/- 0.6 (p < 0.001). This was accompanied by significant improvements in fibrinogen (from 2.9 +/- 0.1 g/l at baseline to 2.6 +/- 0.1 g/l, p = 0.011), white blood cells (from 7.0 +/- 0.4 to 6.2 +/- 0.3 x 10(9)/l, p = 0.005) and the high-density/low-density lipoprotein (HDL/LDL) ratio (0.33 +/- 0.03 to 0.37 +/- 0.03, p < 0.005). Following 8 weeks of abstinence from smoking, the mean white blood cell count was further reduced (to 6.1 +/- 0.3 x 10(9)/l, p = 0.026 vs. baseline) and there were also significant improvements in HDL (from 1.16 +/- 0.06 mmol/l at baseline to 1.32 +/- 0.06, p < 0.001) and LDL (from 3.78 +/- 0.16 mmol/l at baseline to 3.52 +/- 0.17, p = 0.015). In conclusion, 8 weeks of smoking reduction resulted in clinically significant improvements in established cardiovascular risk factors. These improvements were even greater after an additional period of abstinence from smoking.

Adult↗

PubMed2000

Stable insertion of the early light-induced proteins into etioplast membranes requires chlorophyll a.

Etiolated plant seedlings exposed to light respond by transient accumulation of the nucleus-encoded, plastid-located early light-inducible proteins (Elips). These proteins are distant relatives of the light-harvesting chlorophyll a/b-binding gene family and bind pigments with unusual characteristics. To investigate whether accumulation of Elips in plastid membranes is post-translationally regulated by pigments, reconstitution studies were performed, where in vitro transcribed and translated low molecular mass Elip precursors of barley were combined with lysed barley etioplasts complemented with various compositions of isolated pigments. We showed that the membrane insertion of Elips, as proven by protease protection assays and washes with a chaotropic salt or alkali, depended strictly on chlorophyll a but not on chlorophyll b or xanthophyll zeaxanthin. The amount of inserted Elips increased almost linearly with the chlorophyll a concentration, and the insertion efficiency was not significantly influenced by a light intensity between 1 and 1,000 micromol x m(-2) x s(-1). In contrast, in vitro import of Elip precursors into greening plastids was enhanced by high intensity light. Thus, we conclude that although chlorophylls bound to Elips seem to not be involved in light harvesting, they are crucial for a stable insertion of these proteins into the plastid membrane.

Arabidopsis Proteins↗

PubMed2000

[Acceptance of wearing a hearing aid by children].

BACKGROUND: Having one or 2 hearing aids is not a guarantee that a child will wear the instruments constantly. The purpose of this study was to evaluate the hearing aid acceptance by children (assessed using the daily wearing time). PATIENTS AND METHODS: A total of 116 parents of a patient population of persistent hearing-impaired children with a need for a hearing aid (average age 51.1 +/- 30.1 months) rated the wearing acceptance of their children on a 5-point-Likert-scale. This assessment was made after the child had received its individual hearing aid for its specific disorder (on average after 5 months). Hearing levels ranged from mild to profound. RESULTS: 58.6% of the children accepted their electroacoustic aids amplier "excellent" or "good", 18.1% did it "average", 23.3% "bad" to "miserable" or even "not at all". There was no significant difference between girls and boys. The wearing acceptance from children with unilateral hearing impairments was reduced, especially from those with chronic conductive disorders by malformations of the ears. Very young children (prelingual hearing impairments), mainly those with additional handicaps and/or not German speaking homes demonstrated a "bad" to missing wearing behaviour. Hearing acceptance did not correlate with the severity of the disorder. CONCLUSION: The wearing acceptance as one aspect of compliance should be rated before each regular hearing aid control. Finally it is an efficient and sensitive mean to detect faulty amplification and changed diagnosis.

Child↗

PubMed2000

[Acceptance of wearing hearing aids by children: a longitudinal analysis].

There exist no systematic longitudinal studies concerning the acceptance of hearing aids in Germany. This study examines the acceptance of a hearing aid (defined by its daily/weekly use) in the management of children with persistent sensorineural hearing loss over a period of years. 35 children with monaural or binaural hearing loss were treated with a hearing aid. All children had at least a 25-dB averaged mid-frequency pure-tone hearing loss (500, 1000, 2000, 4000 Hz). The data consist of standardized parent ratings at 4 points in time over a period of nearly 30 months. Unilateral-impaired children wore their hearing aids less often than bilateral-impaired children. This effect was not significant at the beginning (P = 0.85) but increased over time. By the end the difference was significant (P = 0.004). Mild to moderate monaural hearing-impaired children accepted their hearing aids, whereas children with severe to profound hearing loss refused to wear them. Bilateral hearing-impaired children demonstrated, a priori, a better wearing acceptance that even improved with time. There was never a significant difference between boys and girls in their average wearing time. A significant correlation of age and wearing acceptance was also not observed at any time. Hearing aids are an effective treatment with high acceptance and compliance, especially by children with bilateral sensorineural hearing loss. The quality of acceptance of monaural hearing-impaired children needs to be studied further.

Auditory Threshold↗

PubMed2000

Foix-Chavany-Marie (anterior operculum) syndrome in childhood: a reappraisal of Worster-Drought syndrome.

Foix-Chavany-Marie syndrome (FCMS) is a distinct clinical picture of suprabulbar (pseudobulbar) palsy due to bilateral anterior opercular lesions. Symptoms include anarthria/severe dysarthria and loss of voluntary muscular functions of the face and tongue, and problems with mastication and swallowing with preservation of reflex and autonomic functions. FCMS may be congenital or acquired as well as persistent or intermittent. The aetiology is heterogeneous; vascular events in adulthood, nearly exclusively affecting adults who experience multiple subsequent strokes; CNS infections; bilateral dysgenesis of the perisylvian region; and epileptic disorders. Of the six cases reported here, three children had FCMS as the result of meningoencephalitis, two children had FCMS due to a congenital bilateral perisylvian syndrome, and one child had intermittent FCMS due to an atypical benign partial epilepsy with partial status epilepticus. The congenital dysgenetic type of FCMS and its functional epileptogenic variant share clinical and EEG features suggesting a common pathogenesis. Consequently, an increased vulnerability of the perisylvian region to adverse events in utero is discussed. In honour of Worster-Drought, who described the clinical entity in children 40 years ago, the term Worster-Drought syndrome is proposed for this unique disorder in children.

Adolescent↗

PubMed2000

Acoustic voice analysis by means of the hoarseness diagram.

The hoarseness diagram (Michaelis, Fröhlich, & Strube, 1998a) has been proposed as a new approach to describe different acoustic properties of voices. To test its performance in the analysis of pathologically disturbed and normal voices five requirements are suggested that should be met by any acoustic voice-analysis protocol to be used in voice research and clinical practice. The hoarseness diagram is then tested with regard to these requirements. Individual voices are found to show a satisfactory localization in the diagram. Aspects of stationarity are discussed in the context of four case studies. The different cases illustrate that changes in the acoustic analysis results are observed if the voice-generation conditions change, whereas results are stationary if phonation conditions do not change. Different pathological voice groups defined on grounds of the specific phonation mechanism are found to map to specific regions of the hoarseness diagram, with differences between group locations being significant. All results can be interpreted without exceptions if the two hoarseness diagram coordinates are taken to reflect the vibrational irregularity of the voice-generation mechanisms on the one side and the degree of closure of the vibrating structures on the other side. The hoarseness diagram and its underlying algorithms are thus shown to constitute a useful approach to acoustic voice analysis in research and clinical practice. The tests themselves demonstrate several application possibilities, including the quantitative monitoring of individual voices.

Adolescent↗

PubMed2000

Role of magnesium chelatase activity in the early steps of the tetrapyrrole biosynthetic pathway.

Magnesium-protoporphyrin IX chelatase (Mg-chelatase) is located at the branchpoint of tetrapyrrole biosynthesis, at which point protoporphyrin IX is distributed for the synthesis of chlorophyll and heme. We investigated the regulatory contribution of Mg-chelatase to the flow of metabolites. In plants, the enzyme complex consists of three subunits, designated CHL D, CHL I, and CHL H. Transgenic tobacco (Nicotiana tabacum) plants expressing antisense RNA for the Mg-chelatase subunit CHL H were analyzed to elucidate further the role of Mg-chelatase in the distribution of protoporphyrin IX into the branched tetrapyrrolic pathway. The transgenic plants displayed a reduced growth rate and chlorophyll deficiency. Both phenotypical properties were correlated with lower Mg-chelatase activity. Unexpectedly, less protoporphyrin IX and heme accumulated, and a decrease in 5-aminolevulinate (ALA)-synthesizing capacity and ALA dehydratase activity paralleled the progressive reduction in Mg-chelatase activity in the transformants compared with control plants. The reduced activities of the early enzymatic steps corresponded with lower levels of transcripts encoding glutamyl-tRNA reductase and ALA-dehydratase. The decreased expression and activities of early enzymes in the pathway could be explained by a feedback-controlled mechanism in response to lower Mg-chelatase activity. We discuss intercompartmental signaling that synchronizes the activities of the first steps in tetrapyrrolic metabolism with the late steps for the synthesis of end products.

Lyases↗

PubMed1999

Effects on vocal function and incidence of laryngeal disorder when using a laryngeal mask airway in comparison with an endotracheal tube.

A study of 56 patients was undertaken to determine whether there is a difference in the effect of the laryngeal mask airway and the endotracheal tube on the vocal tract after short-duration anaesthesia. All the patients were interviewed pre- and post-operatively. In 43 patients, it was possible to assess the larynx using videoendoscopy and videostrobolaryngoscopy both pre- and post-operatively. Selected acoustic characteristics were investigated in 51 patients pre- and 18-24 h post-operatively. Thirty-four patients that did not have anaesthesia were used as an age-matched control. The interview showed, that patients in the LMA group complained less frequently of having post-operative laryngeal discomfort. The videostrobolaryngoscopy demonstrated minor lesions of the vocal tract in six patients in the ETT group and in one patient in the LMA group. Of the 12 voice variables evaluated, there was no significant difference in any parameter between the two groups. Both groups had a higher fundamental frequency post-operatively.

Adolescent↗

PubMed1999

Reduced activity of geranylgeranyl reductase leads to loss of chlorophyll and tocopherol and to partially geranylgeranylated chlorophyll in transgenic tobacco plants expressing antisense RNA for geranylgeranyl reductase

The enzyme geranylgeranyl reductase (CHL P) catalyzes the reduction of geranylgeranyl diphosphate to phytyl diphosphate. We identified a tobacco (Nicotiana tabacum) cDNA sequence encoding a 52-kD precursor protein homologous to the Arabidopsis and bacterial CHL P. The effects of deficient CHL P activity on chlorophyll (Chl) and tocopherol contents were studied in transgenic plants expressing antisense CHL P RNA. Transformants with gradually reduced Chl P expression showed a delayed growth rate and a pale or variegated phenotype. Transformants grown in high (500 &mgr;mol m-2 s-1; HL) and low (70 &mgr;mol photon m-2 s-1; LL) light displayed a similar degree of reduced tocopherol content during leaf development, although growth of wild-type plants in HL conditions led to up to a 2-fold increase in tocopherol content. The total Chl content was more rapidly reduced during HL than LL conditions. Up to 58% of the Chl content was esterified with geranylgeraniol instead of phytol under LL conditions. Our results indicate that CHL P provides phytol for both tocopherol and Chl synthesis. The transformants are a valuable model with which to investigate the adaptation of plants with modified tocopherol levels against deleterious environmental conditions.

Journal Article↗

PubMed1998

[Objective description of voice quality using the hoarseness diagram].

The need for an objective assessment of voice quality can be seen in the increasing use of acoustic analysis methods for clinical diagnosis and research. The hoarseness diagram allows clinicians to objectively describe even highly disturbed or aphonic votes. Its application possibilities are illustrated in three case studies in which changes in voice quality were monitored during voice rehabilitation. The distributions of voice groups that were defined on the basis of specific pathophysiological phonation conditions were then compared for their acoustic differences. The groups comprised various phonation conditions after the resection of laryngeal tumors and different types of laryngeal paralyses. Interpretation of the results suggests a direct correspondence of the hoarseness diagram coordinates and the irregularity of vibration on the one side and the degree of glottal closure on the other. This illustrates the potential usefulness of the hoarseness diagram in a clinical context.

Adult↗

PubMed1998

Psychological profiles of patients with laryngeal contact granulomas.

The association between laryngeal contact granuloma and demographic/psychological variables was examined by using a psychosomatic approach to health research. A stepwise procedure of logistic regression analyses was utilized to get a final multivariate model of variables associated with the clinical finding of a laryngeal contact granuloma. The subjects consisted of 47 patients with contact granulomas and 110 patients with voice disorders due to other causes. Our analysis of 22 variables uncovered the following statistically significant factors for developing a contact granuloma: male gender (P = 0.0001), low achievement orientation (P = 0.0007), fear of physical lesions (P = 0.0038), impulsiveness (P = 0.0016), age > 60 years (P = 0.0012), low extraversion (P = 0.004), high achievement orientation (P = 0.0079), fear of appearing in public (P = 0.0216) and strain (P = 0.03). These results show that a variety of variables are important for predicting the development of a laryngeal contact granuloma. The usefulness of this set of risk variables for predicting a contact granuloma remains to be proved in a prospective study. It is possible that not only the nature but the number of risk factors are the prime determinants of outcome.

Achievement↗

PubMed1998

[Higher touch and kinesthetic functions in children with former speech/language development disorders: a neuropsychological study].

Two groups of children took part in this study to test the hypothesis that children diagnosed in infancy as specific speech/language-impaired have deficits in tactile-kinesthetic functions: A formerly clinical group of 25 German-speaking pupils with a mean age of 8;7 years (SD 7.1 months) who have previously been identified as specific speech/language-impaired (on average at 4;11 years, SD 10.6 months) and a control group of 25 normal pupils in elementary school without a former or actual speech/language disorder (mean age: 9;2 years, SD 8.3 months). The control group was matched with the formerly clinical group for gender and age. Performance scores of both groups on a nonverbal intelligence test (the Raven's Matrices), on a tactile-kinesthetic subtest (Berliner-Luria-Neuropsychologisches Verfahren f¿r Kinder), and on a developmental language test (Heidelberger Sprachentwick- lungstest) were compared. There was a significant difference (p < 0.05) in the mean tactile-kinesthetic performance of both groups (3.1 vs. 4.0) who present a nearly identical nonverbal intelligence. Thirty-two percent of the formerly clinical group demonstrated a performance below the norm. Analysis of the laterality did not reveal significant differences in performance between left and right hand, neither in right-handers nor in left-handers of both groups. Nevertheless right-handers demonstrated on average a better somatosensory performance with their left hand. Mean language and tactile-kinesthetic performance correlate significantly in the formerly clinical group (r = 0.45, p < 0.05), but not in the control group (r = 0.08). The formerly clinical group was inferior in performance to the normal subjects especially in complex functions as in the tactile discrimination of sharp/blunt and in topognosia.

Child↗

PubMed1998

Evaluation of side effects after nicotine nasal spray in patients with chronic rhinitis.

Thirty-three subjects with chronic rhinitis used nicotine nasal spray in an open study as an aid in smoking cessation. Thirty-eight percent of them were completely abstinent at 12 weeks, whereas 35% were completely abstinent at 20 weeks. The nasal spray was associated with irritant nasal side effects, which occurred most often in the early stages of treatment. Clinical nasal examinations could not observe any significant impairment in nasal conditions following spray use. In conclusion, this study confirms the short-term safety of the nicotine nasal spray as an aid in smoking cessation.

Administration, Intranasal↗

PubMed1997

Cloning and characterization of a plastidal and a mitochondrial isoform of tobacco protoporphyrinogen IX oxidase.

Protoporphyrinogen IX oxidase is the last enzyme in the common pathway of heme and chlorophyll synthesis and provides precursor for the mitochondrial and plastidic heme synthesis and the predominant chlorophyll synthesis in plastids. We cloned two different, full-length tobacco cDNA sequences by complementation of the protoporphyrin-IX-accumulating Escherichia coli hemG mutant from heme auxotrophy. The two sequences show similarity to the recently published Arabidopsis PPOX, Bacillus subtilis hemY, and to mammalian sequences encoding protoporphyrinogen IX oxidase. One cDNA sequence encodes a 548-amino acid residues protein with a putative transit sequence of 50 amino acid residues, and the second cDNA encodes a protein of 504 amino acid residues. Both deduced protein sequences share 27.2% identical amino acid residues. The first in vitro translated protoporphyrinogen IX oxidase could be translocated to plastids, and the approximately 53-kDa mature protein was detected in stroma and membrane fraction. The second enzyme was targeted to mitochondria without any detectable reduction in size. Localization of both enzymes in subcellular fractions was immunologically confirmed. Steady-state RNA analysis indicates an almost synchronous expression of both genes during tobacco plant development, greening of young seedlings, and diurnal and circadian growth. The mature plastidal and the mitochondrial isoenzyme were overexpressed in E. coli. Bacterial extracts containing the recombinant mitochondrial enzyme exhibit high protoporphyrinogen IX oxidase activity relative to control strains, whereas the plastidal enzyme could only be expressed as an inactive peptide. The data presented confirm a compartmentalized pathway of tetrapyrrole synthesis with protoporphyrinogen IX oxidase in plastids and mitochondria.

Amino Acid Sequence↗

PubMed1997

Spasmodic laryngeal dyspnea: a rare manifestation of laryngeal dystonia.

We describe clinical experiences in the management of three patients with laryngopharyngeal dystonia causing severe breathing problems. In contrast to spasmodic dysphonia, which presents with action-induced involuntary spasm of laryngeal muscles during speaking, all three patients showed laryngopharyngeal spasms primarily during respiration. In analogy to spasmodic dysphonia we propose the term spasmodic laryngeal dyspnea for this rare condition. Localized unilateral botulinum toxin injected into the thyroarytenoid muscle and/or ventricular folds reduced the quantity and quality of spasms and led to a pronounced improvement of breathing problems.

Aged↗

PubMed1997

Identification and diagnostic evaluation of hearing impairments in early childhood in German-speaking infants.

The present study was devised to gather epidemiological information to aid in understanding the etiology, identification, and management of children with permanent hearing losses in Lower Saxony as a defined geographical area of Germany. All infants and preschool children were identified in the Department of Phoniatrics and Pediatric Audiology during a 1-year period (October 1994 until October 1995). Forty-four hearing-impaired children were identified, of whom 41 (93%) had sensorineural losses and 3 had pure conductive losses. Thirty-two children (73%) had bilateral hearing impairments. The causes of hearing loss were unknown in 17 children (39%). The median age of identification for the study group was 32 months, with a median age of 35.5 months when fitting hearing aids. Severity of hearing loss was inversely associated with age of identification. Prelingually deaf children had the worst comprehension levels of all children tested psychologically. Results were tabulated and special references to other studies were discussed. Our findings show again that the successful out-come of speech and language development depends on early identification and management of the hearing loss, and on continued assessment of the progress of habilitation. These require a basic assessment of the stage of language development (in perception and expression) as relevant rehabilitation measures. The next step is the treatment of existing linguistic deficits followed by retests at regular intervals.

Child, Preschool↗