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Biomedical subjects

R Brunner

Publications and source records attributed to R Brunner.

At least 19 recordsLinked to original sources
PubMed2000

A Definitive Optical Detection of a Supercluster at z approximately 0.91.

We present the results from a multiband optical imaging program that has definitively confirmed the existence of a supercluster at z approximately 0.91. Two massive clusters of galaxies, Cl 1604+4304 at z=0.897 and Cl 1604+4321 at z=0.924, were originally observed in the high-redshift cluster survey of Oke, Postman, & Lubin. They are separated by 4300 km s-1 in radial velocity and 17&arcmin; on the plane of the sky. Their physical and redshift proximity suggested a promising supercluster candidate. Deep BRi imaging of the region between the two clusters indicates a large population of red galaxies. This population forms a tight, red sequence in the color-magnitude diagram at (R-i&parr0; approximately 1.4. The characteristic color is identical to that of the spectroscopically confirmed early-type galaxies in the two member clusters. The red galaxies are spread throughout the 5 h-1 Mpc region between Cl 1604+4304 and Cl 1604+4321. Their spatial distribution delineates the entire large-scale structure with high concentrations at the cluster centers. In addition, we detect a significant overdensity of red galaxies directly between Cl 1604+4304 and Cl 1604+4321 which is the signature of a third, rich cluster associated with this system. The strong sequence of red galaxies and their spatial distribution clearly indicate that we have discovered a supercluster at z approximately 0.91.

Journal Article↗
PubMed2000

Near-field scanning optical microscopy of zinc-porphyrin crystals.

Using a near-field scanning optical microscope (NSOM), crystals of zinc-porphyrin network materials are characterized with respect to morphology and fluorescence. Needle-shaped crystals are observed. While the topography is flat, the fluorescence intensity profile in the width direction is approximately triangular. A numerical calculation shows that differences between the topographic and optical images cannot be due to an artifact. In some needle-shaped crystals, the fluorescence emission is strongly peaked at one or both ends, possibly indicating a polar crystal structure.

Crystallization↗
PubMed2000

Acute and long-term effects on muscle force after intramuscular aponeurotic lengthening.

Intramuscular aponeurotic lengthening of muscles or intramuscular tenotomy involves bisecting the connective tissue fibers of the aponeurosis or tendon within the muscle belly. Because of its superficial location in the muscle, the aponeurosis may be bisected without damaging muscle fibers. Despite the existence of common operative methods for gaining length in short muscles, the effects on force and muscle function have not been studied. For this purpose animal experiments were performed. The medial gastrocnemius muscle of six male Wistar rats was lengthened by cutting the proximal aponeurosis at 50% of its length perpendicularly to the collagen fibers. The length gain was maintained by 3 days of cast immobilization at maximal dorsiflexion of the ankle. The long-term effect of the treatment was studied after 6 weeks and compared with 10 untreated controls and with six sham operated animals. The muscle was isolated in situ, and the force length characteristics were determined. In the untreated controls, the aponeurotomy was performed and the length force experiment was repeated to study the acute effects. The aponeurotic lengthening led acutely to a temporary loss of force because of an incomplete connection of the distal part of the muscle to the proximal insertion, but force recovered completely within 6 weeks. Although results from animal experiments cannot be transferred directly to humans, the principles of physiology are similar. Thus, for clinical use, aponeurotic lengthening should be considered if muscle force needs to be preserved. However, the drop of muscle force after surgery must be respected when mobilizing the patient during the postoperative rehabilitation program.

Animals↗
PubMed2000

Dissociative symptomatology and traumatogenic factors in adolescent psychiatric patients.

This study describes the relation of different types of childhood trauma to the degree of dissociative experiences. Subjects were 198 consecutively admitted adolescent psychiatric patients, 11 to 19 years old (89 inpatients and 109 outpatients). All patients completed the Adolescent Dissociative Experiences Scale. A Checklist of Traumatic Childhood Events was filled out by clinicians. The results showed an increase in the degree of dissociative experiences in patients with a history of sexual abuse, physical abuse, neglect, and stressful life events. With the exception of life events, a moderate form of traumatic experience had the same effect on dissociative experiences as severe forms. The strongest effect was found for emotional neglect, which seems to be an important pathogenic risk factor. The results suggest that therapists and researchers should be aware that even less severe forms of abuse and neglect may have a significant impact on the development of dissociative psychopathology in adolescents.

Adolescent↗
PubMed2000

Influence of membrane differential filtration on the natural course of age-related macular degeneration: a randomized trial.

PURPOSE: Membrane differential filtration is able to optimize rheologic parameters by eliminating high molecular weight proteins and lipoproteins from the blood. Following the hypothesis that these changes result in an improvement of the microcirculation, the authors tested the efficacy of membrane differential filtration in improving visual function in patients with age-related macular degeneration (ARMD). METHODS: Forty patients (40 eyes) were randomized into two groups. The treatment group was treated five times over a period of 21 weeks. In both groups, 9/20 of the eyes showed subfoveolar subretinal neovascularization. The main parameter of the study was visual acuity (VA). Electroretinogram (ERG), electrooculogram, and macular visual evoked potentials were also recorded. Plasma and whole blood viscosity and erythrocyte aggregation were measured. RESULTS: The 20 patients treated repeatedly over a period of 21 weeks showed a mean improvement of 0.63 lines (SD 1.8) of VA on Early Treatment Diabetic Retinopathy Study charts. The control group showed a deterioration of 0.94 lines (SD 1.7) compared to VA at baseline examination. The amplitude of the ERG photopic a-wave and the flicker ERG was significantly increased. The rheologic parameters were lowered in all treated patients. CONCLUSION: Repetitive treatment with membrane differential filtration is able to improve visual acuity of patients with ARMD and the natural course of this disease. Several questions arise from the results of this study. Further research will show if it is possible to optimize the selection of patients for subgroups with predictive responses through morphologic and functional tests and how to create an optimized and individual treatment strategy determined by the quality, intensity, and frequency of treatment sessions.

Aged↗
PubMed1999

The structure of chromatophores from purple photosynthetic bacteria fused with lipid-impregnated collodion films determined by near-field scanning optical microscopy.

Lipid-impregnated collodion (nitrocellulose) films have been frequently used as a fusion substrate in the measurement and analysis of electrogenic activity in biological membranes and proteoliposomes. While the method of fusion of biological membranes or proteoliposomes with such films has found a wide application, little is known about the structures formed after the fusion. Yet, knowledge of this structure is important for the interpretation of the measured electric potential. To characterize structures formed after fusion of membrane vesicles (chromatophores) from the purple bacterium Rhodobacter sphaeroides with lipid-impregnated collodion films, we used near-field scanning optical microscopy. It is shown here that structures formed from chromatophores on the collodion film can be distinguished from the lipid-impregnated background by measuring the fluorescence originating either from endogenous fluorophores of the chromatophores or from fluorescent dyes trapped inside the chromatophores. The structures formed after fusion of chromatophores to the collodion film look like isolated (or sometimes aggregated, depending on the conditions) blisters, with diameters ranging from 0.3 to 10 microm (average approximately 1 microm) and heights from 0.01 to 1 microm (average approximately 0.03 microm). These large sizes indicate that the blisters are formed by the fusion of many chromatophores. Results with dyes trapped inside chromatophores reveal that chromatophores fused with lipid-impregnated films retain a distinct internal water phase.

Bacterial Chromatophores↗
PubMed1999

MRP expression in acute myeloid leukemia. An update.

To determine the clinical significance of the multidrug resistance protein (MRP) in patients with de novo AML, we have studied MRP expression of leukemic cells at diagnosis and its association with clinical outcome in 127 patients. MRP expression was determined by immunocytochemistry by means of monoclonal antibodies QCRL-1/QCRL-3. MRP expression was low, intermediate and high in 30%, 46% and 24% of the patients, respectively. MRP expression was independent of age and sex of the patients, white blood cell count, FAB subtype, serum lactate dehydrogenase levels and karyotype aberrations. MRP expression had no impact no response to induction chemotherapy. The complete remission rates were 75%, 70% and 64% for patients with low, intermediate and high expression, respectively. Patients with intermediate or high MRP expression showed a trend toward shorter overall survival (p = 0.09) as compared to patients with low MRP expression. MRP does not predict for response to induction chemotherapy but intermediate or high MRP expression might be associated with shorter overall survival of the patients.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1999

[Flatfoot].

Many parents are anxious because of the insufficient arch of the feet of their children. A true congenital deformity (congenital vertical talus) is extremely rare. In children the arch is physiologically flattened with a hypervalgus of the hindfoot. Those feet do not need treatment. If there is no medial recess in the footprint in a child over 3 years of age, then we are talking about a flexible flatfoot. When the load of the foot is more pronounced at the medial rather than at the lateral side, operative treatment can be indicated, such as a lengthening osteotomy of the calcaneum. If the flatfoot is rigid, the reason for it is usually a tarsal coalition. Operative transection of the osseous bridge with fat interposition can solve the problem. Flatfeet may also occur in neuromuscular diseases. Depending on the severity of the deformity, splints can be effective, or--in the more severe cases--operative treatment such as a triple arthodesis can be indicated.

Adolescent↗
PubMed1999

Electrophysiological abnormalities in age-related macular degeneration.

BACKGROUND: Results from psychophysical tests indicate that in age related macular degeneration (ARMD) retinal function is globally impaired. Observations in single ARMD cases showing abnormalities of the electrooculogram (EOG) and electroretinogram (ERG) encouraged us to systematically examine ARMD patients by means of electrophysiological tests to confirm a global retinal dysfunction in ARMD. METHODS: Sixty-six patients with ARMD were examined clinically and by means of EOG, ERG, triple scotopic ERG, and fluorescein angiography (FA). RESULTS: EOG data were considerably reduced in ARMD. Scotopic a- and b-waves of the ERG were mildly affected. The bright flash response showed reduced b-waves with normal implicit times. The amplitude of the oscillatory potential OP2 was significantly reduced and photopic responses were also pathologic compared with an age-matched control group. Geographic atrophy and pigment epithelium detachment showed specific abnormalities in the ERG, whereas in soft drusen EOG changes were more conspicuous. CONCLUSIONS: In addition to data from psychophysical tests the results from electrophysiological examinations indicated a global reduction of retinal function in ARMD which seemed to be present not only in the macula but also elsewhere in the retina.

Aged↗
PubMed1999

Acute effects of intramuscular aponeurotomy on rat gastrocnemius medialis: force transmission, muscle force and sarcomere length.

Acute effects of intramuscular aponeurotomy on muscle force and geometry as a function to muscle length were studied in rat m. gastrocnemius medialis (GM). Acutely after aponeurotomy, activation of the muscle at increasing lengths (acute trajectory) showed a spontaneous and progressive but patial tearing of the connective tissue interface between the fibres inserting directly proximally and distally to the location of the section. After this the muscle consisted morphologically of a stable proximal and a distal part (post-aponeurotomy). Post-aponeurotomy mean active sarcomere length within fibres of the proximal part was shown to be unaffected. In contrast, mean sarcomere length within the distal part was reduced substantially after aponeurotomy. However active sarcomeres in the distal part were still attaining higher lengths with increasing muscle lengths (p<0.005), indicating myofascial force transmission through the intact part of the connective tissue interface of the muscle parts. Post-aponeurotomy optimum muscle force was reduced substantially to less than 45% of pre-aponeurotomy values. During the acute trajectory the muscle yielded approximately 20% higher forces than post-aponeurotomy, indicating that myofascial force transmission was related to the area of connective tissue interface. It is concluded that after aponeurotomy of the proximal aponeurosis of rat GM, fibres without direct myotendinous connection to the origin of the muscle are still able to contribute to muscle force. As the magnitude of reduction in muscle force can only be explained partially by the spontaneous rupture of the connective tissue interface between proximal and distal muscle part, other factors causing a decrease of muscle force are present. Clinical implication of acute effects of intramuscular aponeurotomy are discussed.

Animals↗
PubMed1999

Improvement of visual acuity in patients suffering from diabetic retinopathy after membrane differential filtration: a pilot study.

BACKGROUND: Membrane differential filtration is an extracorporeal treatment procedure which eliminates high molecular weight proteins and lipids from the blood. This pilot study was initiated to investigate the short-term effects on blood rheology and visual function in patients suffering from diabetic retinopathy. METHODS: Six patients with non-proliferative diabetic retinopathy, clinically significant macular edema (five patients, nine eyes) and inactive proliferative diabetic retinopathy (one patient, one eye) underwent a single treatment with a hollow fiber secondary plasma filter. The main parameter measured was visual acuity prior to and after treatment. Biochemical and rheological parameters (whole blood and plasma viscosity, and erythrocyte aggregation) were also measured. The mean follow-up was 25 (range 4-90) days after treatment. RESULTS: The mean improvement of visual acuity was 1.4 lines (SD 0.8 lines, p = 0.002) 24 h after therapy. This remained stable during the follow-up period. The rheological measures were significantly lowered. A significant reduction of total protein, fibrinogen, IgG, IgM, IgA, alpha-2-macroglobulin, total cholesterol, LDL and HDL was found. CONCLUSION: This study demonstrates the rheological impact of membrane differential filtration. It was shown that rheological changes correlated with clinical improvement in patients suffering from diabetic retinopathy with clinically significant macular edema.

Aged↗
PubMed1999

[Modification of vision by change in rheologic parameters in senile macular degeneration through membrane differential filtration--initial results of a randomized study].

BACKGROUND: Membrane differential filtration (MDF) is known to optimize rheological parameters by eliminating high molecular weight proteins und lipoproteins from the blood and was shown to influence ocular perfusion parameters. Following the hypothesis that these changes may influence the natural course of age-related macular degeneration (AMD) we tested their efficacy in improving visual function in these patients in a randomized trial. PATIENTS AND METHODS: 20 patients (36 eyes) were randomized into two groups. Ten patients (18 eyes) were treated with MDF and ten (18 eyes) served as controls. The first group was treated five times over a period of 21 weeks. In both groups 8/18 of the eyes showed subfoveolar subretinal neovascularisations. Main parameter of the study was visual acuity. Macular visual evoked potentials were also recorded. Plasmaviscosity, whole blood viscosity and erythrocyte aggregation were measured. RESULTS: The ten patients, treated repeatedly over a period of 21 weeks, showed a mean improvement 1.1 (SD 1.9) lines after 21 weeks, while the control group showed a deterioration of visual acuity (0.6 lines, SD 1.7). The macular visual evoked potentials showed an increase of 0.28 microV (SD 1.12) for the therapy group and a deterioration of 0.57 microV (SD 1.31) in the control group. The rheological parameters were lowered in all patients. CONCLUSIONS: We conclude that repetitive treatment with MDF is able to improve visual function in patients with AMD. Further research is necessary to show how to optimize the selection of patients and how to create an individual treatment strategy.

Aged↗
PubMed1999

[Conservative treatment of neurogenic foot deformities].

The lack of muscle control in neurological disorders often leads to deformities of the foot. The equinus (a contracture of the triceps surae muscle), the abduction and clubfoot deformity are the most common ones. The present paper describes the deformities and stresses the functional relevance for the patient. Therapeutic principles of the conservative orthopaedic means are described with special emphasis on the need of an adequate height of the aide and the foot position. Casting and the application of Botulinun toxine are described having a major side effect of muscle weakening. A combination of the different procedures, surgical interventions included, need to be selected for each patient offering the best management for each individual problem.

Adolescent↗
PubMed1999

[Childhood sexual abuse in the history of patients in high-frequency psychoanalytic long-term therapy--prevalence and diagnosis].

276 treatment records of patients who were undergoing high-frequent, outpatient, individual, psychoanalytic therapy were analysed with respect to the prevalence and patterns of childhood sexual abuse in the history of these patients. 22.8% of all patients experienced narrowly defined sexual abuse during childhood (the end of the 17th year); additionally, 35.2% of all patients reported minor forms of sexually abusive experiences. The gender distribution, the age at onset of sexual abuse, and the relationship to the perpetrator were analysed. Looking at psychoanalytic diagnoses, a significant correlation between a history of childhood sexual abuse and a diagnosis of hysterical neurosis was found.

Adult↗
PubMed1999

[Brief report of working group OPD-CA (children and adolescents) Axis IV: structural standard].

Apart from the structural differentiation of the body and its functions, the enlargement of the child's repertoire of possibilities to make experiences and to act is a manifestation of the development of the child's psychic structure which, advancing in years, may be considered as a treasure of all the experiences one has made with oneself, with the world and with the others. Structure will develop along with the interactional experiences with the world around us and becomes manifest in one's behaviour which may be witnessed and observed. The description of the psychic structure comprises three dimensions (perception of the self and of the objects, control, communication and bonding) which will be described by certain capabilities and will be assessed with the help of an anchoring example typical for each age which serves the purpose of clinical illustration. The adaptational achievement may then be assessed on the basis of a structural standard independent of age and may be ranged on a structural level. It appears that the exemplary description of different scopes of tasks typically to be performed at certain ages which serves as a basis for the assessment of the adaptational competence during childhood and adolescence seems to be a good policy. The purpose of our studies is the development of a valid instrument which is easy to handle in practice and which has a high interrater-reliability.

Adolescent↗