Street crossing behavior in younger and older pedestrians: an eye- and head-tracking study

Background

Crossing a street can be a very difficult task for older pedestrians. With increased age and potential cognitive decline, older people take the decision to cross a street primarily based on vehicles’ distance, and not on their speed. Furthermore, older pedestrians tend to overestimate their own walking speed, and could not adapt it according to the traffic conditions. Pedestrians’ behavior is often tested using virtual reality. Virtual reality presents the advantage of being safe, cost-effective, and allows using standardized test conditions.

Methods

This paper describes an observational study with older and younger adults. Street crossing behavior was investigated in 18 healthy, younger and 18 older subjects by using a virtual reality setting. The aim of the study was to measure behavioral data (such as eye and head movements) and to assess how the two age groups differ in terms of number of safe street crossings, virtual crashes, and missed street crossing opportunities. Street crossing behavior, eye and head movements, in older and younger subjects, were compared with non-parametric tests.

Results

The results showed that younger pedestrians behaved in a more secure manner while crossing a street, as compared to older people. The eye and head movements analysis revealed that older people looked more at the ground and less at the other side of the street to cross.

Conclusions

The less secure behavior in street crossing found in older pedestrians could be explained by their reduced cognitive and visual abilities, which, in turn, resulted in difficulties in the decision-making process, especially under time pressure.

Decisions to cross a street are based on the distance of the oncoming cars, rather than their speed, for both groups. Older pedestrians look more at their feet, probably because of their need of more time to plan precise stepping movement and, in turn, pay less attention to the traffic. This might help to set up guidelines for improving senior pedestrians’ safety, in terms of speed limits, road design, and mixed physical-cognitive trainings.

Ibandronate in stable renal transplant recipients with low bone mineral density on long-term follow-up

BACKGROUND

Bone mineral density (BMD) has been reported to increase without specific treatment in long-term renal transplant recipients. The aim of this study was to evaluate the effect of ibandronate on BMD and kidney function in long-term renal transplant recipients as compared to a control group. Furthermore, we searched for a gender-specific treatment effect of ibandronate on BMD.

METHODS

In a retrospective, matched case-control study 60 stable renal transplant recipients were included on long-term follow-up. The patient cohort was divided into two groups. The control group (n = 30) comprised patients with close-to-normal bone mineral density who did not receive ibandronate treatment and the treatment group (n = 30) comprised patients with reduced bone mineral density who received ibandronate treatment. The groups were matched for sex, age at the time of renal transplantation, use of steroids, renal transplant function and time lag between the dual-energy X-ray absorptiometry (DEXA) measurements and renal transplantation. Patients of the treatment group were treated with 12.0 ± 6.7 g ibandronate. Treatment cycles lasted 19.3 ± 11.0 months. The first bone mineral density testing was performed 55.3 ± 60.2 months after renal transplantation followed by a second measurement 26.8 ± 12.1 months later.

RESULTS

Both groups did not differ in absolute (g/cm(2)) or relative (%) changes in BMD at the lumbar spine (0.033 ± 0.079 vs. 0.055 ± 0.066 g/cm(2), p = 0.217 and 3.6 ± 7.8 vs. 6.4 ± 8.1 %, p = 0.124) or femoral neck (0.013 ± 0.106 vs. 0.025 ± 0.077 g/cm(2), p = 0.647 and 3.2 ± 13.6 vs. 5.0 ± 13.1 %, p = 0.544) over the study period. There was no correlation of ibandronate dosages with changes in BMD (LS: r = -0.089; p = 0.639 and FN: r =+0.288; p = 0.445). We could neither determine a negative effect of ibandronate on renal transplant function over the study period, estimated via the CKD-EPI formula (-2.9 ± 7.6 vs. -2.7 ± 10.6 mL/min/1.73 m(2), p = 0.900) nor a gender-specific action of ibandronate on bone mass changes.

CONCLUSIONS

Ibandronate treatment was safe with respect to renal transplant function but did not result in a significant additive improvement in bone mineral density as compared to the untreated control group. A gender-specific action of ibandronate on BMD at the LS or FN could not be determined either.

[Schizophrenic Psychoses with Motor-Dominant Symptoms: Considerations for a System-Specific Approach]

In order to reduce heterogeneity in schizophrenia, a system-specific approach consisting of the domains "language", "affect" and "motor behavior" has been proposed. We examined this system-specific approach for its applicability to clinical practice in the motor behavior domain, using the methodological approach of case studies, and discuss here the differences to the positive/negative concept. We analyzed eight cases with stable motor-dominant symptoms, and also quantitatively assessed motor behavior by using the Bern Psychopathology Scale (BPS), a standardized psychopathological assessment instrument, as well as actigraphic data. Characterization of cases using the positive/negative approach was not helpful. We found an overlap of the motor behavior domain with the other two domains. This complicates the application of the system-specific approach in the sense of a typology. Furthermore, we found both relapsing courses with full remission and chronic courses with deterioration within the motor-dominant subtype. Nevertheless, the system-specific approach has heuristic utility for the future.

Confirmation of TTC8 as a disease gene for nonsyndromic autosomal recessive retinitis pigmentosa (RP51)

Nonsyndromic retinitis pigmentosa (RP) is genetically highly heterogeneous, with >100 disease genes identified. However, mutations in these genes explain only 60% of all RP cases. Blood samples were collected from 12 members of an autosomal recessive RP family. Whole genome homozygosity mapping and haplotype analysis placed the RP locus in this family at chromosome 14q31.3. Whole-exome sequencing (WES) in proband revealed a mutation in TTC8, which was flagged as most likely candidate gene by bioinformatic analysis. TTC8 is mutated in Bardet-Biedl syndrome 8 (BBS8), and once reported previously in a family with nonsyndromic RP. Sequencing of amplified products of exon 13 of TTC8 validated c.1347G>C (p.Gln449His), a novel change that affects the final nucleotide of exon 13 and might deleteriously affect splicing. This mutation segregated completely with the disease in the family and was not observed in 100 ethnically matched controls from same population. This represents second report of a TTC8 mutation in nonsyndromic RP, thus confirming the identity of TTC8 as causative gene for RP51.

[S3 Guideline. Part 3: Non-Traumatic Avascular Necrosis in Adults - Surgical Treatment of Atraumatic Avascular Femoral Head Necrosis in Adults]

The present article describes the guidelines for the surgical treatment of atraumatic avascular necrosis (aFKN). These include joint preserving and joint replacement procedures. As part of the targeted literature, 43 publications were included and evaluated to assess the surgical treatment. According to the GRADE and SIGN criteria level of evidence (LoE), grade of recommendation (EC) and expert consensus (EK) were listed for each statement and question. The analysed studies have shown that up to ARCO stage III, joint-preserving surgery can be performed. A particular joint-preserving surgery currently cannot be recommended as preferred method. The selection of the method depends on the extent of necrosis. Core decompression performed in stage ARCO I (reversible early stage) or stage ARCO II (irreversible early stage) with medial or central necrosis with an area of less than 30 % of the femoral head shows better results than conservative therapy. In ARCO stage III with infraction of the femoral head, the core decompression can be used for a short-term pain relief. For ARCO stage IIIC or stage IV core decompression should not be performed. In these cases, the indication for implantation of a total hip replacement should be checked. Additional therapeutic procedures (e.g., osteotomies) and innovative treatment options (advanced core decompression, autologous bone marrow, bone grafting, etc.) can be discussed in the individual case. In elective hip replacement complications and revision rates have been clearly declining for decades. In the case of an underlying aFKN, however, previous joint-preserving surgery (osteotomies and grafts in particular) can complicate the implantation of a THA significantly. However, the implant life seems to be dependent on the aetiology. Higher revision rates for avascular necrosis are particularly expected in sickle cell disease, Gaucher disease, or kidney transplantation patients. Furthermore, the relatively young age of the patient with avascular necrosis should be seen as the main risk factor for higher revision rate. The results after resurfacing (today with known restricted indications) and cemented as well as cementless THA in aFKN are comparable for the appropriate indication to those in coxarthrosis or other diagnoses. Regardless of the underlying disease endoprosthetic treatment in aFKN leads to good results. Both cemented and cementless fixation techniques can be recommended.

Subtyping schizophrenia: A comparison of positive/negative and system-specific approaches

BACKGROUND

Schizophrenia is a heterogeneous disorder. Over the years, different approaches have been proposed to approach this heterogeneity by categorizing symptom patterns. The study aimed to compare positive/negative and system-specific approaches to subtyping.

METHODS

We used the Positive and Negative Syndrome Scale (PANSS) and Bern Psychopathology Scale (BPS), which consists of subscales for three domains (language, affect and motor behavior) that are hypothesized to be related to specific brain circuits, to assess cross-sectional psychopathological characteristics in a sample of 100 inpatients with schizophrenia spectrum disorders. We then categorized participants into positive/negative and system-specific subgroups to allow comparisons of the two approaches.

RESULTS

The analyses revealed correlations between the PANSS positive subscore and the BPS affective subscore (r=.446, p<.001) and between the PANSS negative subscore and the BPS motor behavior subscore (r=.227, p=.023). As regards the positive and negative subtype, more participants were classified as positive in the language-dominant subtype (30.3%) and affect-dominant subtype (30.3%), whereas more were classified as negative in the motor behavior-dominant subtype (44.4%). However, most patients met the criteria for the mixed subtype.

CONCLUSIONS

The results suggest that the positive/negative and system-specific approaches can be regarded as complementary. Future studies should examine both approaches in a longitudinal assessment of psychopathological symptoms and link them with qualitative-phenomenological approaches.

In-vivo multilaboratory investigation of the optical properties of the human head

The in-vivo optical properties of the human head are investigated in the 600-1100 nm range on different subjects using continuous wave and time domain diffuse optical spectroscopy. The work was performed in collaboration with different research groups and the different techniques were applied to the same subject. Data analysis was carried out using homogeneous and layered models and final results were also confirmed by Monte Carlo simulations. The depth sensitivity of each technique was investigated and related to the probed region of the cerebral tissue. This work, based on different validated instruments, is a contribution to fill the existing gap between the present knowledge and the actual in-vivo values of the head optical properties.

[Manifestation of bilateral choroidal osteoma in childhood. Progressive myopia due to staphyloma posticum]

BACKGROUND

Case report of a 6-year-old boy with bilateral choroidal osteoma.

CASE REPORT

The patient was followed up for the next 6 years and during this period bilateral tumor progression was observed. In one eye a staphyloma posticum developed in the area of the osteoma which led to secondary anisometric myopia.

CONCLUSION

If undetected, this rare complication can lead to anisometric amblyopia; therefore, repeated cycloplegic refractometry is advisable in children with choroidal osteoma.

[Organic personality disorder: conceptual principles, clinical symptoms and treatment]

The organic personality disorder is primarily characterized by a change of premorbid behavior due to an organic impairment or disease of the central nervous system. German psychopathological preliminary work had a determining influence on the current diagnostic concepts in the international classification of diseases 10 (ICD-10) and the diagnostic and statistical manual of mental disorders 5 (DSM-5). An analysis of the literature in the MEDLINE database shows that most studies can be found for traumatic brain injury and epilepsy. The most common symptoms described were symptoms of depression, emotional instability, irritability and impulsive behavior. Psychopathological symptoms were not related to the etiopathogenesis but showed some relation to the neuroanatomical location of functional disorders or damages. Only few publications on treatment strategies were found. The empirical findings point to the necessity of multiaxial diagnostic measures to distinguish between the levels of etiology and symptomatology. Therapeutic interventions should be planned on the basis of psychopathological symptoms.

[Course typologies of schizophrenic psychoses]

The "group of schizophrenias" describes a heterogeneous nosological construct with a variable course of the illness. Against this background, several historical approaches to course typologies of schizophrenic psychoses have been described (Bleuler; Huber; Leonhard; Watt, Katz and Shepherd). These concepts, however, differ considerably from each other, in particular with respect to the definition of outcomes. This mainly results from the reference to different psychopathological traditions. The possible codings of subgroups and course types of schizophrenic psychoses in ICD-10 and DSM-5 are compromises in order to combine the different aspects. The empirical examination and the advancement of course typologies of schizophrenic disorders using modern instruments and analyses are important tasks for current psychiatric research. Such efforts should combine quantitative-statistical analyses with a casuistic approach.

Experimental and computational studies on the femoral fracture risk for advanced core decompression

BACKGROUND

Two questions are often addressed by orthopedists relating to core decompression procedure: 1) Is the core decompression procedure associated with a considerable lack of structural support of the bone? and 2) Is there an optimal region for the surgical entrance point for which the fracture risk would be lowest? As bioresorbable bone substitutes become more and more common and core decompression has been described in combination with them, the current study takes this into account.

METHODS

Finite element model of a femur treated by core decompression with bone substitute was simulated and analyzed. In-vitro compression testing of femora was used to confirm finite element results.

FINDINGS

The results showed that for core decompression with standard drilling in combination with artificial bone substitute refilling, daily activities (normal walking and walking downstairs) are not risky for femoral fracture. The femoral fracture risk increased successively when the entrance point is located further distal. The critical value of the deviation of the entrance point to a more distal part is about 20mm.

INTERPRETATION

The study findings demonstrate that optimal entrance point should locate on the proximal subtrochanteric region in order to reduce the subtrochanteric fracture risk. Furthermore the consistent results of finite element and in-vitro testing imply that the simulations are sufficient.

Adiponectin attenuates osteolysis in aseptic loosening of total hip replacements

Joint replacements have a longer durability in patients with high serum levels of adiponectin (APN) than in patients with low levels. We aimed to characterize the unknown pathophysiological effects of APN on wear particle-induced inflammation, apoptosis and osteolysis. Immunohistochemistry was performed to detect APN, its receptors and apoptosis in patients with and without aseptic loosening. Additionally, APN knockout mouse studies and pharmacological intervention of APN were performed in an established calvarial mouse model. Osteolysis and inflammation were quantified by histomorphometry and microcomputed tomography, apoptosis by immunohistochemistry and TUNEL assay. In a cell culture model, human monocyte-derived macrophages were incubated with or without metal wear debris particles and partially treated with APN. Expression of APN, AdipoR1 and calreticulin in specimens from patients with aseptic loosening were significantly higher than in patients without aseptic loosening. Administration of APN in mice significantly reduced wear particle-induced inflammation, osteolysis and the number of caspase-3-positive macrophages. The cell culture model showed that APN leads to significantly lower values of TNF-α. These findings support a prominent role of APN in the development of particle-induced osteolysis and APN may be therapeutically useful in patients with aseptic loosening.

[Psychopathological differentiation of depressive syndromes]

The historical contributions of Kurt Schneider, Karl Leonhard, Hans-Jörg Weitbrecht and Hubertus Tellenbach provide different concepts for a psychopathological differentiation of depressive syndromes. The current diagnostic systems ICD-10 and DSM-5 also contain categories for a differentiated classification of depressive disorders that trace back to the above historical concepts. The extensive diagnostic concepts of "depressive episode" or "major depression", however, are mainly based on the severity of symptomatology in terms of the number of symptoms and on their temporal duration. This approach could result in a lack of psychopathological differentiation and the limitation to a more syndromal and dimensional view of depression. In contrast, a differentiated typology of depressive phenomenology based on traditional psychopathological concepts could be useful both for clinical treatment decisions and for neurobiological research.