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Biomedical subjects

Thomas Fuchs

Publications and source records attributed to Thomas Fuchs.

At least 19 recordsLinked to original sources
PubMed2006

Genetic analysis of a novel pathway for D-xylose metabolism in Caulobacter crescentus.

Genetic data suggest that the oligotrophic freshwater bacterium Caulobacter crescentus metabolizes D-xylose through a pathway yielding alpha-ketoglutarate, comparable to the recently described L-arabinose degradation pathway of Azospirillum brasilense. Enzymes of the C. crescentus pathway, including an NAD(+)-dependent xylose dehydrogenase, are encoded in the xylose-inducible xylXABCD operon (CC0823-CC0819).

Arabinose↗
PubMed2006

Time-space learning in homing pigeons (Columba livia): orientation to an artificial light source.

Time-space learning reflects an ability to represent in memory event-stimulus properties together with the place and time of the event; a capacity well developed in birds. Homing pigeons were trained in an indoor octagonal arena to locate one food goal in the morning and a different food goal in the late afternoon. The goals differed with respect to their angular/directional relationship to an artificial light source located outside the arena. Further, the angular difference in reward position approximated the displacement of the sun's azimuth that would occur during the same time period. The experimental birds quickly learned the task, demonstrating the apparent ease with which birds can adopt an artificial light source to discriminate among alternative spatial responses at different times of the day. However, a novel midday probe session following successful learning revealed that the light source was interpreted as a stable landmark and not as a surrogate sun that would support compass orientation. Probe sessions following a phase shift of the light-dark cycle revealed that the mechanism employed to make the temporal discrimination was prevailingly based on an endogenous circadian rhythm and not an interval timing mechanism.

Animals↗
PubMed2006

Specific immunotherapy with standardized latex extract versus placebo in latex-allergic patients.

BACKGROUND: Allergy to natural rubber latex proteins continues to be an important medical problem among health care professionals, but also in multioperated children. Clinical manifestations range from urticaria to angioedema, rhinoconjunctivitis, bronchial asthma and anaphylactic shock. METHODS: The aim of this study was to investigate the efficacy and safety of a 12-month latex-specific immunotherapy in sensitized patients, most often health care workers. Twenty-three patients with latex rhinoconjunctivitis (20 of whom also had asthma) were included in this randomized, double-blind, placebo-controlled trial (11 in the active group, 12 in the placebo group). Treatment efficacy was assessed by means of symptom and medication scores. Conjunctival provocation tests and quantitative skin prick tests were also performed. RESULTS: The clinical index (derived by combining changes from baseline of six efficacy variables during the treatment period) did not differ significantly between treatment groups. Change from baseline of rhinitis, conjunctivitis, skin symptoms, asthma symptoms, medication score and cutaneous reactivity were not significantly different between the two groups. A nonsignificant difference in conjunctival reactivity was observed in favor of the active group (p = 0.09). Systemic reactions were much higher in the specific immunotherapy than in the placebo group. CONCLUSIONS: The present study failed to show a significant improvement of symptoms and medication scores, probably because of the low level of symptoms at baseline and the low maintenance dose of therapy, even if allergen-specific conjunctival reactivity decreased in the active group. Moreover, the incidence of systemic reactions was very high in the active group.

Adult↗
PubMed2006

The effect of locally applied vascular endothelial growth factor on meniscus healing: gross and histological findings.

INTRODUCTION: Tears in the peripheral part of the menisci have a better healing potential than tears in the central part, because the central two-thirds of the menisci are avascular. We hypothesized that healing of meniscus tears in the avascular zone can be promoted by the local application of the angiogenic factor vascular endothelial growth factor (VEGF). MATERIALS AND METHODS: A tear was created in the avascular zone of the medial meniscus in 18 merino sheep. The tear was then repaired with an uncoated suture (group 1), a suture coated with PDLLA (group 2), and by a suture coated with PDLLA/VEGF (group 3). RESULTS: After 6 weeks, we observed increased immunostaining for factor VIII in the VEGF-treated group 3. However, in this treatment group no meniscus healed completely. In the uncoated suture group and in the PDLLA-coated-suture group, partial healing was observed in three animals and complete healing in three animals, respectively. CONCLUSION: In this experiment the local application of VEGF via PDLLA-coated sutures did not promote meniscus healing. Growth factors might not always be a promising tool for tissue repair.

Animals↗
PubMed2006

A selective serotonin reuptake inhibitor reduces REM sleep in the homing pigeon.

Avian and mammalian 'rapid eye movement' sleep (REM sleep) resemble each other in several aspects. However, the question of whether REM sleep has a shared evolutionary ancestry in birds and mammals has yet to be thoroughly explored. The brain regions and neurotransmitter systems involved in the generation of mammalian REM sleep are phylogenetically ancient, and are also found in extant birds and reptiles. Several pharmacological experiments in birds indicate that similar neural substrates are involved in the regulation of avian and mammalian sleep. However, because the drugs used in these studies generally resulted in non-specific sleep loss, the neurochemical regulation of avian REM sleep in particular remains uncertain. The selective serotonin reuptake inhibitor (SSRI) zimelidine is known to reduce REM sleep in mammals. If avian REM sleep is similarly regulated by serotonin, it would be expected that an acute dose of a SSRI should also reduce avian REM sleep. To investigate a putative role of serotonin in the regulation of avian REM sleep, changes in sleep electroencephalogram (EEG) and behavior were recorded in five pigeons (Columba livia) after the administration of an acute dose of zimelidine. Our results demonstrate that the effects of zimelidine on avian REM sleep are comparable to those observed in mammals, indicating that serotonin may serve a similar function in the control of avian and mammalian REM sleep.

Animals↗
PubMed2006

Orthopoxvirus infection transmitted by a domestic cat.

The variola virus was declared eradicated by the World Health Organization in 1980 but human infections by cowpox virus, another member of the genus Orthopoxvirus, are still observed, mainly in European countries. We report a woman who presented with two umbilicated vesicles surrounded by an indurated erythematous edema within cat scratch injuries on her thigh. The diagnosis of an Orthopoxvirus infection was based on the visualization of characteristic virus particles by electron microscopy and the detection of the A27L gene (14-kd fusion protein gene) of the genus Orthopoxvirus by polymerase chain reaction from a lesional skin biopsy specimen. Differential diagnoses of cat scratch disease, pustula maligna, and bullous impetigo were excluded by microbiologic investigation of the biopsy specimen. Both lesions scarred after 6 weeks of a continuous local antiseptic treatment.

Adult↗
PubMed2006

Ethical issues in neuroscience.

PURPOSE OF REVIEW: The study gives an overview of ethical questions raised by the progress of neuroscience in identifying and intervening in neural correlates of the mind. RECENT FINDINGS: Ethical problems resulting from brain research have induced the emergence of a new discipline termed neuroethics. Critical questions concern issues, such as prediction of disease, psychopharmacological enhancement of attention, memory or mood, and technologies such as psychosurgery, deep-brain stimulation or brain implants. Such techniques are capable of affecting the individual's sense of privacy, autonomy and identity. Moreover, reductionist interpretations of neuroscientific results challenge notions of free will, responsibility, personhood and the self which are essential for western culture and society. They may also gradually change psychiatric concepts of mental health and illness. These tendencies call for thorough, philosophically informed analyses of research findings and critical evaluation of their underlying conceptions of humans. SUMMARY: Advances in neuroscience raise ethical, social and legal issues in relation to the human person and the brain. Potential benefits of applying neuroimaging, psychopharmacology and neurotechnology to mentally ill and healthy persons have to be carefully weighed against their potential harm. Questions concerning underlying concepts of humans should be actively dealt with by interdisciplinary and public debate.

Brain↗
PubMed2006

Patch testing with components of water-based metalworking fluids: results of a multicentre study with a second series.

BACKGROUND: Although many allergens in metalworking fluids (MWF) are identified, there are still some MWF components, which are not sufficiently investigated concerning their sensitizing properties. OBJECTIVES: To investigate sensitization to 10 frequently used MWF components, which are not part of the established MWF test series, in metalworkers with suspected occupational dermatitis due to MWF. PATIENTS/METHODS: Oleyl alcohol, myristyl alcohol, dimethylolurea, 4,4'-methylenebis morpholine, imazalil, 1-amino-2-propanol (monoisopropanolamine; MIPA), 2-amino-2-ethyl-1,3-propanediol (AEPD), 2,5-bis(n-octyldithio)-1,3,4-thiadiazole, zinc alkyl dithiophosphate and dibenzyl disulfide have been patch tested in 144 patients. RESULTS: 7 patients reacted positively to the formaldehyde releaser 4,4'-methylenebis morpholine, and 6 of these patients also reacted to formaldehyde and/or other formaldehyde releasers. 4 patients reacted positively to myristyl alcohol tested at 10% petrolatum (pet.). Additionally, 20 doubtful or irritant reactions occurred. 1 patient each reacted positively to oleyl alcohol, MIPA, and AEPD. None of the other test substances mentioned above elicited any clear-cut positive reaction. Patch testing with well-known MWF allergens showed proportions of positive reactions, which were comparable to those from other studies, e.g. 11% to monoethanolamine, 8% to colophonium and 3%-5% to various preservatives. CONCLUSIONS: 4,4'-methylenebis morpholine may be an important MWF allergen, although clinical relevance could not be stated definitely in every case. Myristyl alcohol should not be patch tested at 10% pet., but at a lesser concentration, due to irritant properties.

Adult↗
PubMed2005

Delusional mood and delusional perception -- a phenomenological analysis.

In the initial stages of schizophrenia, the environment as perceived by the patient changes into a puzzling, mysterious and stage-like scenery. At the same time, objects or persons may gain an overwhelming physiognomic expression and may even fuse with the patient's body. The paper explains these different alterations using Husserl's concept of intentional perception on the one hand, and Merleau-Ponty's concept of embodied perception on the other hand. The first may also be understood as describing the intersubjective constitution of reality through common concepts which structure intentional perception. The latter points to the embodiment of the perceiving subject and uncovers our intimate connection with the world mediated by the lived body. Thus, in each perception, an active, intentional or 'gnostic' component and a bodily, 'pathic' component work together. On this basis, the alteration of schizophrenic perception in delusional mood may be described as a paralysis of intentionality, or of the 'gnostic' component of perception. The synthetic and sense-bestowing processes effective in perception are seriously disturbed. On the other hand, as a result of the disturbance of intentional perception, physiognomic and expressive properties are set free within the perceptual field. The 'pathic' component of perception becomes independent. Thus, the intersubjective constitution of reality is replaced by idiosyncratic meanings and qualities of perception, leading finally into delusional perception.

Adult↗
PubMed2005

A controlled prospective case control study of a prevention training program in female team handball players: the German experience.

BACKGROUND: Few authors have investigated the effectiveness of preventive intervention in European team handball. PURPOSE: The aim of the present study was to evaluate the effects of a prevention program on the incidence of injuries in female European team handball players. STUDY DESIGN: Prospective controlled study. METHODS: Ten female handball teams (134 players) took part in the prevention program (1. Information about injury mechanism, 2. Balance-board exercises, 3. Jump training) while 10 other teams (142 players) were instructed to train as usual. Over one season all injuries were documented weekly. RESULTS: Ankle sprain was the most frequent diagnosis in both groups with 11 ankle sprains in the control group and 7 ankle sprains in the intervention group (Odds ratio: 0.55, 95% confidence interval: 0.22-1.43). The knee was the second frequent injury site. In the control group 5 of all knee injuries were anterior cruciate ligament (ACL) ruptures (incidence: 0.21 per 1000 h) in comparison with one in the intervention group (incidence: 0.04 per 1000 h). Odds ratio was 0.17 with 95% confidence interval of 0.02-1.5. CONCLUSIONS: This study confirms that proprioceptive and neuromuscular training is appropriate for the prevention of knee and ankle injuries among female European team handball players.

Adult↗
PubMed2005

Locally applied angiogenic factors--a new therapeutic tool for meniscal repair.

Tears in the peripheral part of the menisci have a better healing potential than tears in the central part, because the central two-thirds of the menisci are avascular. The avascular status of the meniscus is maintained by the expression of antiangiogenic factors such as endostatin. The distribution of endostatin in the menisci correlates with the degree of vascularization. Endostatin immunostaining is strong in the avascular zone and reduced in the vascularized outer one-third. Endostatin interacts with signal transduction of the vascular endothelial growth factor (VEGF) by reducing VEGF-induced kinase (Erk1/2) phosphorylation. VEGF plays an important role in angiogenesis in fetal menisci and it is down-regulated in the adult meniscus. We hypothesized that healing of meniscal tears in the avascular zone can be promoted by the local application of the angiogenic factor VEGF. To evaluate this hypothesis a tear was created in the avascular zone of the medial meniscus in 18 merino sheep. The tear was then repaired with an uncoated suture (group 1), a suture coated with PDLLA (group 2), and by a suture coated with PDLLA/VEGF (group 3). After 6 weeks we observed increased factor VIII immunostaining in the VEGF-treated group. However, in this treatment group (VEGF/PDLLA) no meniscus healed. In the uncoated suture group and in the PDLLA-coated suture group partial healing was observed in three animals and complete healing in three animals, respectively. Factor VIII expression is normally restricted to vascular endothelial cells. In this study, however, single endothelial cells could be detected in the menisci of the VEGF/PDLLA group. This finding suggests that the application of VEGF might have stimulated proliferation of vascular endothelial cells but the application of VEGF was not successful in stimulating the more complex process of vasculogenesis. Further immunohistochemical examinations of the specimen have shown that in the VEGF/PDLLA group there is strong immunostaining against matrix metalloproteinase 13 (MMP-13). In vitro studies have shown that VEGF can stimulate chondrocytes to proliferate but also to express MMP-13 via HIF1-alpha induction. Since meniscal fibrochondrocytes express the VEGF receptor 2 (KDR) the induction of MMP expression might be another factor which inhibits healing despite increased angiogenesis. In conclusion, the local application of VEGF via PDLLA-coated sutures does not promote meniscal healing. A single growth factor might not always be a promising tool for the promotion of tissue repair. Further studies have to find out if growth factor combinations (VEGF and angiopoitin) might be more effective in stimulating vasculogenesis during meniscal healing.

Angiostatic Proteins↗
PubMed2004

Interactive regulation of affect in postpartum depressed mothers and their infants: an overview.

Specific patterns of interaction emerging in the first months of life are related to processes regulating mutual affects in the mother-child dyad. Particularly important for the dyad are the matching and interactive repair processes. The interaction between postpartum depressed mothers and their children is characterized by a lack of responsiveness, by passivity or intrusiveness, withdrawal and avoidance, as well as a low level of positive expression of affect. Thus, an impaired capability to regulate the child's affect has been demonstrated in depressed mothers. Maternal aggression, neglect toward infants, infanticidal thoughts, as well as infanticidal behavior are mainly linked to severe postpartum depression, especially with psychotic symptoms. The findings on mother-child interaction reported in this paper are based on mothers with mild to moderate depressive disorders without psychotic symptoms. Considering the stability of interaction patterns in the course of depressive illness as well as the long-term consequences of these interactions, it seems surprising that there are still few systematic studies of depressed mothers interacting with their infants. In connection with an overview on these issues, treatment models for parent-infant psychotherapy are discussed.

Aggression↗
PubMed2003

Neurofeedback treatment for attention-deficit/hyperactivity disorder in children: a comparison with methylphenidate.

Clinical trials have suggested that neurofeedback may be efficient in treating attention-deficit/hyperactivity disorder (ADHD). We compared the effects of a 3-month electroencephalographic feedback program providing reinforcement contingent on the production of cortical sensorimotor rhythm (12-15 Hz) and betal activity (15-18 Hz) with stimulant medication. Participants were N = 34 children aged 8-12 years, 22 of which were assigned to the neurofeedback group and 12 to the methylphenidate group according to their parents' preference. Both neurofeedback and methylphenidate were associated with improvements on all subscales of the Test of Variables of Attention, and on the speed and accuracy measures of the d2 Attention Endurance Test. Furthermore, behaviors related to the disorder were rated as significantly reduced in both groups by both teachers and parents on the IOWA-Conners Behavior Rating Scale. These findings suggest that neurofeedback was efficient in improving some of the behavioral concomitants of ADHD in children whose parents favored a nonpharmacological treatment.

Attention Deficit Disorder with Hyperactivity↗
PubMed2003

Patch testing with components of water-based metalworking fluids.

Water-based metalworking fluids (MWFs) may cause both irritant and allergic contact dermatitis. Several well-known MWF allergens are available for patch testing, but considering the wide variety of possible components used in MWF, our diagnostic arsenal covers only a small part of potential allergens. We therefore selected 13 frequently used MWF components that might be sensitizers and had not yet been tested routinely. In 5 centres, 233 dermatitis patients with present or past occupational exposure to MWF were patch tested with this and other panels. Only 7 patients showed positive reactions to the study panel. Allergic reactions to the emulsifier diglycolamine [syn. 2-(2-aminoethoxy) ethanol] were seen in 5 patients, and 1 patient each reacted positively to 2-amino-2-ethyl-1,3-propanediol (AEPD) and methyldiethanolamine (MDEA). Clinical relevance of the reactions to diglycolamine was unequivocally proven by its presence in the MWF from the patients' workplace in 3 cases. Diglycolamine seems to be an important MWF allergen, independently from monoethanolamine and diethanolamine. A test concentration of 1% petrolatum (pet.) appears to be appropriate. The importance of AEPD and MDEA as MWF allergens still remains to be established. The lack of positive test reactions to the other MWF components tested may be due to their low-sensitizing potential or too low a patch test concentration being used.

Adult↗