Motor control and cerebral hemispheric specialization in highly qualified judo wrestlers

With the purpose of investigating motor and cognitive lateralization profiles associated with long-term motor training, we investigated differences in hemispheric specialization between proficient judo sportsmen and controls through the assessment of a number of handedness and footedness items including postural preferences as well as dichotic listening and lateralized visual field tests. Our data show that: (1) the different handedness and footedness items did differently relate to each other within the athlete and control groups as revealed by a principle component analysis (PCA); (2) stand side correlated differently to these motor profile factors in athletes and controls; (3) athletes preferred more frequently to perform certain movements with the left hand than controls, although overall right-handed; (4) this was especially true for athletes which proved to be most proficient/skilled; and (5) in a lateralized verbal listening task and a lateralized visual field task athletes revealed enhanced right-hemispheric involvement relative to controls. Our results suggest that during motor and postural skill acquisitions (long-term judo training) lateral preferences are modified, probably due to neuroplasticity. Moreover, the present findings support the multidimensional view of handedness by Steenhuis and Bryden [Cortex 25 (1989) 289] and the notion of a right-hemispheric "praxis system" involved in skilled action routines within peripersonal space [Brain and Cognition 23 (1993) 181].

Deviant olfactory experiences, magical ideation, and olfactory sensitivity: a study with healthy German and Japanese subjects

Little is known about the relationship between olfactory hallucinations and olfactory sensitivity in psychiatric populations. However, in healthy subjects, a 'psychotic-like' feature, namely magical ideation, has been linked to deviant olfactory experiences. We thus assessed olfactory sensitivity, magical ideation and deviant olfactory experiences in 42 healthy subjects (21 Germans and 21 age- and gender-matched Japanese). The results show that: (1) Germans had significantly higher magical ideation scores and a higher frequency of deviant olfactory experiences than Japanese, and more Germans than Japanese reported having had deviant olfactory experiences at least once in their lives; (2) in Germans, the occurrence of deviant olfactory experiences was correlated with higher magical ideation scores; and (3) there was no relationship between olfactory sensitivity (olfactory thresholds) and either deviant olfactory experiences or magical ideation, respectively. We conclude that: (1) the lack of deviant olfactory experiences in Japanese may best be explained by cultural differences in the response attitude towards questionnaires requiring self-disclosure; (2) the positive relationship between magical ideation and deviant olfactory experiences strengthens the supposed link between 'psychotic-like' features in healthy populations and real hallucinations of psychiatric patients; and (3) the absence of a relationship between olfactory sensitivity and deviant olfactory experiences suggests that their anatomical-functional correlates within temporo-limbic regions may differ.

Conditioning the pecking motions of pigeons

The spatio-temporal courses of head and neck motions of pigeons while pecking at small grains are described. Single and serial pecks are distinguished but the inter- and intraindividual variability of the peck kinetics is stressed. Pigeons were then trained with instrumental conditioning procedures to speed-up their pecking. A partial reinforcement schedule where pigeons had to peck repeatedly before receiving reward led to a mild shortening of inter-peck intervals at lower reinforcement rates but surprisingly, a lengthening at higher rates. A schedule where short inter-peck intervals were differentially rewarded yielded a pronounced abbreviation of the inter-peck intervals, but this was achieved by a reduction of the movement path rather than an increase in motion velocity. A schedule whereby increased approach velocities were differentially rewarded yielded marked movement accelerations. When pigeons were rewarded for diminished approach speeds they also showed significant movement decelerations. Finally, it is shown that pigeons could learn to reliably abort their peck approach movement when a visual stimulus signalling a penalty was occasionally presented during the approach movement. The proportion of successful peck interruptions decreased as these interruption signals occurred later during the approach phase. It is concluded that the pecking of pigeons is neither an innately fixed nor a visually ballistic movement. It is instead a multiply controlled and flexibly adaptable response pattern.

Associative processing and paranormal belief

In the present study we introduce a novel task for the quantitative assessment of both originality and speed of individual associations. This 'BAG' (Bridge-the-Associative-Gap) task was used to investigate the relationships between creativity and paranormal belief. Twelve strong 'believers' and 12 strong 'skeptics' in paranormal phenomena were selected from a large student population (n > 350). Subjects were asked to produce single-word associations to word pairs. In 40 trials the two stimulus words were semantically indirectly related and in 40 other trials the words were semantically unrelated. Separately for these two stimulus types, response commonalities and association latencies were calculated. The main finding was that for unrelated stimuli, believers produced associations that were more original (had a lower frequency of occurrence in the group as a whole) than those of the skeptics. For the interpretation of the result we propose a model of association behavior that captures both 'positive' psychological aspects (i.e., verbal creativity) and 'negative' aspects (susceptibility to unfounded inferences), and outline its relevance for psychiatry. This model suggests that believers adopt a looser response criterion than skeptics when confronted with 'semantic noise'. Such a signal detection view of the presence/absence of judgments for loose semantic relations may help to elucidate the commonalities between creative thinking, paranormal belief and delusional ideation.

Electrophysiological alterations and upregulation of ATP receptors in retinal glial Müller cells from rats infected with the Borna disease virus

Infection with the neurotropic Borna disease virus (BDV) causes an immune-mediated neurological disease in a broad range of species. In addition to encephalitis, BDV-infected Lewis rats develop a retinitis histologically characterized by the loss of most retinal neurons. By contrast, the dominating retinal macroglia, the Müller cells, do not degenerate. It is known from several models of neurodegeneration that glial cells may survive but undergo significant alterations of their physiological parameters. This prompted us to study the electrophysiology and ATP-induced changes of intracellular Ca(2+)-concentration ([Ca(2+)](i)) in Müller cells from BDV-infected rat retinae. Freshly isolated cells were used for whole-cell patch-clamp recordings. Whereas neither zero current potentials nor membrane resistances showed significant alterations, the membrane capacitance increased in cells from BDV-infected rats during survival times of up to 8 months. This process was accompanied by a decrease in K(+) current densities. Müller cells from BDV-infected rats were characterized by expression of a prominent fast-inactivating A-type K(+) current which was rarely found in control cells. Moreover, the number of cells displaying Na(+) currents was slightly increased after BDV-infection. ATP evoked increases in [Ca(2+)](i) in Müller cells within retinal wholemounts of both control and BDV-infected animals. However, the number of ATP-responding isolated cells increased from 24% (age-matched controls) to 78% (cells from animals > or =18 weeks after infection). We conclude that in BDV-induced retinopathy, reactive rat Müller cells change their physiological parameters but these changes are different from those in Müller cells during proliferative vitreoretinopathy in man and rabbit.

Changes of the organotypic retinal organization in Borna virus-infected Lewis rats

Retinae of Borna disease virus (BDV)-infected Lewis rats were investigated with emphasis on long-term changes in organotypic tissue organization and glia-neuron relationship. Virus inoculation was attained via intracerebral BDV injection. Following survival times ranging between two and eight months, the retinal thickness was reduced up to one third of that of controls. Photoreceptor segments were completely extinguished and the number of neurons was dramatically reduced. The typical laminar organization of the retina was largely dissolved. Electron microscopy revealed severe spongy degeneration. Large numbers of activated microglia and macrophages were found, both cell types performing very active phagocytosis. The microglial cells expressed an extraordinary phenotype as characterized by large numbers of processes, with some of them penetrating the endfeet of Müller cells and others establishing highly complex interdigitations with vacuolized swellings and endings of neuronal processes. Müller cells were not reduced in number but displayed clear indications of gliosis such as alterations in the immunoreactivity for filament proteins and glutamine synthetase, significantly thickened stem processes, and an altered pattern of K(+) currents in patch-clamp recordings. These findings demonstrate for the first time long-term neuron-glia interactions in the retina of BDV-infected rats. Moreover, the data contribute to our knowledge on structural and functional alterations accompanying persisting virus infection in the central nervous system.

Loose but normal: a semantic association study

An abnormal facilitation of the spreading activation within semantic networks is thought to under-lie schizophrenics' remote associations and referential ideas. In normal subjects, elevated magical ideation (MI) has also been associated with a style of thinking similar to that of schizotypal subjects. We thus wondered whether normal subjects with a higher MI score would judge "loose associations" as being more closely related than do subjects with a lower MI score. In two experiments, we investigated whether judgments of the semantic distance between stimulus words varied as a function of MI. In the first experiment, random word pairs of two word classes, animals and fruits, were presented. Subjects had to judge the semantic distance between word pairs. In the second experiment, sets of three words were presented, consisting of a pair of indirectly related, or unrelated nouns plus a third noun. Subjects had to judge the semantic distance of the third noun to the word pair The results of both experiments showed that higher MI subjects considered unrelated words as more closely associated than did lower MI subjects. We conjecture that for normal subjects high on MI "loose associations" may not be loose after all. We also note that the tendency to link uncommon, nonobvious, percepts may not only be the basis of paranormal and paranoid ideas of reference, but also a prerequisite of creative thinking.

Associations to smell are more pleasant than to sound

To assess and compare the quantitive and qualitative aspects of verbal associations of olfaction and audition, we conducted two verbal category fluency tasks, one consisting of the generation of 'smelling' associations and the other of 'auditory' associations. The responses of the 40 subjects on these fluency tasks were rated as pleasant or unpleasant by themselves as well as by an independent group of 40 subjects. In addition, all 80 healthy, right-handed subjects rated their momentary emotional state on a visual analog scale. The mean number of words generated by the 40 subjects did not differ between the two tasks, and in both tasks pleasant associations were more frequent than unpleasant associations. However, for all subjects, the proportion of pleasant associations was significantly higher in the olfactory compared to the auditory fluency task. The finding of more pleasant associations in both tasks confirms previous reports, but the pronounced effect in the olfactory task suggests that odors may be more hedonically coded than other sensory modalities, i.e., audition. Although there is evidence that the majority of odors are initially perceived as unpleasant, when retrieved from memory, pleasant connotations seem to dominate. The possible mechanisms for this dissociation are discussed.

Implant-supported mandibular telescopic prostheses in oral cancer patients: an up to 9-year retrospective study

PURPOSE

The aim of this retrospective study was to present the results of implant-supported telescopic prostheses in the mandible after removal of malignant tumors.

MATERIALS AND METHODS

Between 1991 and 2000, 24 patients with squamous cell carcinoma (16 irradiated, eight nonirradiated) underwent mandibular rehabilitation with implant-supported telescopic prostheses. A total of 111 dental implants were placed. Treatment complications were observed. The cumulative survival rates of the implants and prostheses were evaluated by lifetable analysis.

RESULTS

Within a mean follow-up period of 30 months (1 to 108 months), only three implants failed. All other implants are still in function. Of 24 patients, 23 were satisfied with their implant-supported telescopic restorations. Soft tissue, implant, or prosthetic complications occurred very rarely. The cumulative implant survival rate was about 97% and the cumulative prosthesis survival rate was about 95% at 9 years.

CONCLUSION

Implants and implant-supported telescopic maxillofacial prostheses can successfully remain in function over a long period. Increased implant and prosthetic complications should not be expected. Therefore, telescopic implant attachments seem to be very useful as a treatment option for prosthetic restoration of the mandible in tumor patients.

Unilateral olfactory perception and magical ideation

We assessed olfactory detection thresholds and discrimination abilities in 40 healthy right-handers (20 women and 20 men). All subjects were also required to complete the Magical Ideation (MI) scale, a well-validated 30-item schizotypy inventory. Over both nostrils, we found elevated thresholds for subjects with high MI scores (at or above the median score of 9.0) compared with those with low scores. In men but not women, specifically left-nostril acuity was inversely correlated to MI raw scores. MI was unrelated to olfactory discrimination performance. These results suggest an association, at least in healthy men, between even moderate signs of schizotypy and deficits in odor detection. The selective impairment of left-nostril performance adds to the growing evidence for left temporal lobe functional abnormalities in people high on MI. This laterality effect is known from previous studies in patients with schizophrenia. However, as a rule, in psychiatric patients olfactory identification rather than simple detection performance was found to be impaired, indicating that the integration of odor information is affected at different levels of processing in schizotypy compared with schizophrenia. Work with completely normal subjects may reasonably complement clinical studies of olfactory perception. Among its advantages are the good subject compliance and the absence of medication effects.

Metabolic effects of HAY's diet

The aim of the study was, to evaluate the metabolic effect of HAY's diet on protein turnover, fat oxidation, respiratory quotient, body fat and weight loss. Twelve healthy adults received an individually regular diet and thereafter a corresponding isocaloric and isonitrogenous 10-day HAY-diet. Protein turnover and 13C-fat oxidation were investigated after administration of [15N]glycine and an [U-13C]algae lipid mixture. The 15N and 13C enrichment in urine and breath were measured by isotope ratio mass spectrometry. The respiratory quotient was measured by indirect calorimetry. Body fat, total body water and lean body mass were estimated by bio-electric impedance analysis. HAY's diet led to a significantly higher 13C-fat oxidation (15.4 vs. 22.0% P < 0.01), corresponding to a lower respiratory quotient (0.88 vs. 0.81; P < 0.01), whereas the protein turnover remained constant in both diets (3.06 vs. 3.05 g/kg/day). HAY's diet did not reduce total body water, lean body mass, body fat and body weight (72.2 vs. 71.4 kg).

[Therapeutic facial surgery possibilities for orbital tumors]

Based on a large experience of more than 400 orbital tumours which were treated operatively, the surgical strategies are described in detail. A surgical approach including the temporary removal of one or more bony orbital walls provided excellent exposure of the intraorbital structures. Using microsurgical techniques for tumour removal the surgical morbidity could be minimized. Subsequent refixation of the osteotomized orbital bones with microplates and screws and skin incisions within the hair bearing parts of the skull resulted in excellent postoperative function and cosmesis. For many malignant orbital tumours definitive cure can only be achieved by an orbital exenteration procedure. An individually tailored surgical and reconstructive strategy (if possible preservation of eyelid skin, tarsal and bulbar conjunctiva) gives a significant benefit, as well with respect to function as to the esthetic outcome of the patient.

A new application for craniofacial implants: wigs

PURPOSE

The purpose of this study was to describe a new application of craniofacial implants, as anchoring elements for wigs.

MATERIALS AND METHODS

In two patients, a split-skin graft was used to close a soft tissue defect in the occipital, parietal, temporal, and frontal region (defect size of 10 cm x 33 cm and 10 cm x 14 cm). Six titanium implants were placed in each patient. Six months after implant placement, abutment connection was performed and titanium magnets were adapted. Subsequently, an implant-retained wig was constructed.

RESULTS

In a follow-up period of between 10 and 22 months no implant failed. The incorporated wigs effectively retain a functionally and cosmetically successful craniofacial rehabilitation.

CONCLUSION

Despite these successful treatments, further research is needed before craniofacial implants as anchoring elements for wigs can be considered a standard option in the rehabilitation of craniofacial alopecic defects.

Clostridium innocuum: a glucoseureide-splitting inhabitant of the human intestinal tract

Glycosylureides were recently described as non-invasive markers of intestinal transit time. The underlying principle is an enzymatic splitting of (13)C-labelled ureides by intestinal bacteria. The (13)CO(2) released from the urea moiety of the glycosylureides can be measured in breath samples when the ingested tracer substrate reaches the caecum that is colonised with microbes. To date, the microbes that degrade glycosylureides are unknown. In order to identify the glucoseureide (GU)-splitting bacteria, 174 different strains of intestinal microbes obtained from five healthy adults were checked for their ability to degrade GU. The results of the microbial cultures and thin layer chromatography revealed that GU was exclusively degraded by Clostridium innocuum, belonging to the normal human intestinal microflora. C. innocuum probably synthesises a yet unknown enzyme that splits the glucose-urea bond. We suggest that the term glucoseureidehydrolase is the appropriate designation for this enzyme.

[Effects of oral administration of bifidobacteria on intestinal microflora in premature and newborn infants]

In a prospective, randomised study the effects of orally administered bifidobacteria on the intestinal microflora were investigated in 100 preterm and term neonates under intensive care conditions during the first 21 days of life. The 50 infants (group with bifidobacteria) received lyophilized bifidobacteria (Töpfer Bifidus) via nasogastral tube with an initial dosage of 3 times daily 1.25 x 10(8) bifidobacteria on day 2 of life and a daily dosage of 6 times 1.25 x 10(8) bifidobacteria on day 3 until day 21 of life. The other 50 infants (control group) did not receive bifidobacteria. The preterm and term neonates were fed either with pasteurized mother's milk or milk from healthy female donors (n = 79) or with an infant formula (Alfaré, n = 13) or initially with Alfaré and thereafter with mother's milk (n = 8). The intestinal microflora of preterm and term neonates under intensive care conditions could be influenced by the oral administration of bifidobacteria. The administration of bifidobacteria resulted in the group of inoculated infants in a significantly earlier colonization of bifidobacteria (8.1 +/- 3.9 days of life) than in the control group (11.3 +/- 4.7 days of life). On day 7 a bifidobacterial dominance (> 90% of the intestinal microflora) could be found in 26% of infants with inoculation of bifidobacteria and only in 2% of the control group (p < 0.001). These significant differences could be shown until day 21 of life. A difference in septicemia frequency between the two groups could not be demonstrated. At the beginning of the infection a bifidobacterial dominance was found in only one of 23 cases of septicemia.

Compact organization of rRNA genes in the filamentous fungus Ashbya gossypii

The rDNA cluster in the phytopathogenic fungus Ashbya gossypii consists of approximately 50 tandem repeat units of 8197 bp. Each unit carries a gene for the 35S pre-rRNA, processed into 18S, 5.8S and 25S rRNA, and a divergently transcribed gene for 5S rRNA. The well-characterized rDNA of the yeast Saccharomyces cerevisiae is the only other example of a completely sequenced rDNA unit (9137 bp) carrying both a 35S pre-rRNA and a 5S rRNA gene. The coding regions for the 5S, 5.8S, 18S and 25S rRNAs are 95-100% identical whereas transcribed and non-transcribed spacers show 43-66% sequence identity. Functionally characterized rDNA and rRNA elements of S. cerevisiae can be unambiguously recognized in the A. gossypii sequence, including the RNA polymerase-I transcription start site, two Reb1p enhancer binding sites and numerous recognition sequences for rRNA modification and processing. In addition to these functionally characterized sequences eight highly conserved elements from 10 to 71 bp were detected in the over 600-bp transcribed region upstream of the 18S rRNA gene which most likely play as yet uncharacterized functions at the DNA or RNA level. In addition to this work we started to identify A. gossypii homologs of S. cerevisiae nucleolar proteins involved in rDNA maturation.

Ten-year experience in oral implant rehabilitation of cancer patients: treatment concept and proposed criteria for success

Between 1988 and 1997, 18 irradiated patients (group 1, 83 implants) and 22 nonirradiated patients (group 2, 92 implants) received resection of the cancer-involved mandible and floor of the mouth and subsequently underwent mandibular rehabilitation with endosseous implants. Implant-supported prostheses were placed in 26 patients, while 13 patients received implant-tissue-supported prostheses. Between 1988 and 1991, patients were restored with implant-tissue-supported prostheses (based on 2 to 4 implants). This strategy was later changed because of the development of denture-related lesions. Since 1992, group 1 patients have been restored exclusively with implant-supported prostheses on 5 to 6 implants; group 2 patients have been rehabilitated alternatively with implant-tissue-supported prostheses on 4 implants. Special criteria for determining the success of implant-supported maxillofacial prostheses were developed. With a mean follow-up period of 37 months, 160 implants (91%) were clinically osseointegrated. Both types of restorations provided sufficient oral rehabilitation. However, only completely implant-supported prostheses avoided soft tissue ulcers. The cumulative success rate was approximately 75% after 7 years for group 1 patients and about 86% after 10 years for group 2 patients. The success rates for implants placed after the change in strategy were approximately 86% (group 1) and 94% (group 2) after 5 years. Based on these experiences, it is suggested that irradiated patients should be restored with exclusively implant-supported prostheses, without any mucosal contact.

Neural command of electromotor output in mormyrids

The electric discharge of mormyrid fish has an irregular pattern controlled by the electromotor command nucleus in the medulla. Anatomical studies suggest that much of the descending information integrated by the command nucleus comes from the diencephalic precommand nucleus. But field potentials related to the motor command occur later in the precommand nucleus than in the command nucleus, suggesting that they are a corollary rather than a cause of electromotor command initiation. Recorded extracellularly, certain precommand nucleus units fire spontaneously between electromotor commands but pause briefly following each command; others units fire a burst of spikes only during the post-command pause. The firing frequency of the former is correlated with the duration of the interval between successive electromotor commands when the fish is discharging at more than approximately 5 Hz. The post-command pause in spontaneous firing is due to corollary-discharge-mediated feedback inhibition, probably generated by the activity of the bursting units that fire only during this period. Precommand nucleus neurons are activated by electrosensory input, and stimulation of the precommand nucleus modulates the endogenous pattern of electromotor command. We propose that the irregular rhythm of the motor command depends largely on the integration of descending information of various origins, conveyed via the precommand nucleus to the command nucleus, and that this process is regulated by corollary discharge feedback inhibition to the precommand nucleus.

[Prosthetic-implantology defect treatment concept for oral rehabilitation of the mandibular area after tumor treatment]

Between 1988 and 1997, tumor resection was carried out in 18 irradiated patients group 1: 36-72 Gy. 83 implants) and 22 nonirradiated patients (group 2: 92 implants) in the mandible and floor of the mouth, and these patients subsequently underwent mandibular endosseous implant rehabilitation. A total of 23 patients were treated with exclusively implant-supported prostheses, and 16 with implant tissue-supported constructions. Between 1988 and 1991, group 1 and 2 patients received implant tissue-supported prostheses (using two to four implants). Due to prosthesis-related pressure lesions, the strategy has now been changed. Since 1992, group 1 patients have received exclusively implant-supported prostheses (using five to six implants), while group 2 patients have received implant tissue-supported constructions (using four implants). Special criteria for the success of implant-supported maxillofacial prosthetics were drawn up. With an average follow-up period of 37 months 160 fixtures (91%) were clinically osseointegrated. Both types of restoration provided sufficient oral rehabilitation. However, only completely implant-supported prostheses avoided soft tissue ulcers. The overall success rate was about 77% after 7 years in group 1 and about 87% after 9 years in group 2. With regard to implants placed after strategy change, the 5-year success rate was approximately 86% (group 1) and 94% (group 2). In irradiated patients, an exclusively implant-supported prosthesis without any mucosal contact (thus avoiding soft tissue ulcers with a potential to develop osteoradionecrosis) should therefore be fabricated. Implant tissue-supported restoration is also possible in nonirradiated oral cancer patients.

[Persistent Lactobacillus casei subspecies rhamnosus bacteremia in a 14 year old girl with acute myeloid leukemia. A case report]

The present clinical observation is related to a 14-year-old girl suffering from acute myeloid leukemia. The clinical course was complicated by episodes of severe enterocolitis, E. coli- septicemia, pancreatitis and pneumonia. In the course of continued cytostatic and antibiotic treatment a persistent asymptomatic Lactobacillus casei subsp. rhamnosus-bacteremia became detectable by a total of 18 blood cultures. Microbial cultures of the faeces revealed colony-forming unites of this germ in orders of 10(9)/g. Antibiotic eradication attempts according to the resistogram were not successful. The Lactobacillus-bacteremia disappeared only after 13 months when the cytostatic therapy was terminated. An adjuvant influence of the Lactobacillus infection on the outcome of the underlying disease cannot be excluded.

Breaking the bad news: dilemmas in shared decision-making in medical practice

In a review of the literature, very little empirically based research was uncovered to guide the practice of health professionals who need to tell their patients bad news and help them to decide on their preferred treatment option. Various practising styles and guidelines are presented, and ethical and crosscultural challenges discussed. An enormous amount of research still needs to be done to discover the least stressful ways of dealing with these issues in health care settings.

Potent dipeptide inhibitors of the pp60c-src SH2 domain

The design, synthesis, and evaluation of dipeptide analogues as ligands for the pp60c-src SH2 domain are described. The critical binding interactions between Ac-Tyr-Glu-N(n-C5H11)2 (2) and the protein are established and form the basis for our structure-based drug design efforts. The effects of changes in both the C-terminal (11-27) and N-terminal (51-69) portions of the dipeptide are explored. Analogues with reduced overall charge (92-95) are also investigated. We demonstrate the feasibility of pairing structurally diverse subunits in a modest dipeptide framework with the goal of increasing the druglike attributes without sacrificing binding affinity.