Search Results (56)

The dorsomedial caudate–putamen (dmCPu), a key input structure of the basal ganglia, plays a crucial role in goal-directed behaviors and the transition to habits. The functional specialization of the dmCPu along its anteroposterior axis suggests that distinct prefrontal cortex (PFC) subregions may differentially contribute to these processes. However, the precise topographical organization of PFC and adjacent areas projections to the anterior and posterior dmCPu remains poorly understood. We employed retrograde tracing using Fluoro-Gold to map the projections from PFC subregions and adjacent areas to the anterior and posterior dmCPu in male Sprague Dawley rats. Histological verification and immunohistochemical labeling were conducted to confirm injection sites and neuronal labeling. Quantitative analyses were performed to assess the effects of injection site placement (anterior vs. posterior dmCPu), laterality (ipsilateral vs. contralateral), and cortical subregion on projection density. The posterior dmCPu received significantly higher projection densities than the anterior dmCPu, with a pronounced ipsilateral dominance across all cortical subregions. Among the subregions examined, the cingulate cortex exhibited the highest number of labeled neurons projecting to the dmCPu, with distinct patterns of connectivity between anterior and posterior injection sites. Notably, motor and somatosensory cortical projections were more prominent in the posterior dmCPu, whereas cingulate projections demonstrated robust anteroposterior and lateralized differences. These findings provide a comprehensive map of the topographical organization of cortical inputs to the dmCPu, highlighting differential connectivity patterns that may underlie distinct functional roles in goal-directed and habitual behaviors. This work advances our understanding of corticostriatal circuits and their relevance to adaptive behaviors and neuropsychiatric disorders. Full article

Background/Objectives: Understanding sex-based differences in both the pathophysiology and clinical presentation of diseases is necessary to improve health care towards precision medicine. The endocrine system is deeply involved in human health, and endocrine diseases may be influenced by steroidal hormone exposure. Thyroid nodular disease and differentiated thyroid cancer, in particular, show a high prevalence in the female sex; however, little is known about sex-related differences in risk factors and clinical presentation. This study aims to assess whether morphological differences, which can be detected by ultrasound examination, can be related to sex in order to refine diagnostic approaches and oncological risk classification. Methods: A retrospective observational study on 1355 ultrasound images of thyroid nodules obtained from 2017 to 2020 at a single university center was conducted. The images were reviewed by a single observer blinded to the patient’s sex and the cytological nature of the nodules. The qualitative description, size, anatomical location and oncological risk classification were assessed. Results: A taller-than-wide shape (anteroposterior/craniocaudal axis ratio > 1) was found to be more frequent in men than in women (6.7% vs. 3.6%, p = 0.027); the nodular volume was significantly larger in males (p << 0.01) than in females. Significant tropism for the upper lobe and isthmus was described in women (26% vs. 16.5%, p = 0.011) and for medium–lower thyroid lobes in men (83.5% vs. 73.8%, p = 0.011). Background thyroiditis was more common in women, while the number of cytological diagnoses of malignant or likely malignant nodules was higher than expected in men (9% vs. 6%, p = 0.01). Conclusions: Thyroid nodules show different distributions, in terms of a larger volume, more frequent taller-than-wide shape and lobular caudal location, in men vs. women. These results should be confirmed by further investigations, and the underlying mechanism should be clarified. However, our explorative research is of interest due to its novelty and possible future clinical implications. Full article

HOX genes play essential roles in patterning the anteroposterior axis of animal embryos and in the formation of various organs. In mammals, there are 39 HOX genes organized into four clusters (HOXA–D) located on different chromosomes. In relationship with their orderly arrangement along the chromosomes, these genes show nested expression patterns which imply that embryonic territories co-express multiple HOX genes along the main body axis. Interactomic database entries, as well as a handful of publications, support that some HOX proteins can form homodimers or interact with other HOX proteins. However, the consequences of HOX protein interactions have been poorly investigated and remain largely elusive. In this study, we compiled a repository of all HOX–HOX interactions from available databases, and taking HOXA1, HOXA2, and HOXA5 as examples, we investigated the capacity of HOX proteins to form homo- and heterodimers. We revealed that while the DNA-binding domain, the homeodomain, is not necessary for HOXA1 homodimerization, the nuclear localization of the dimerization is dependent on the homeodomain, particularly the integrity of the third helix of HOXA1. Furthermore, we demonstrated that HOXA1 can influence the localization of HOXA1 when it is deprived of the homeodomain, increasing its abundance in the chromatin-containing fraction. Moreover, HOXA1 nuclear homodimerization occurs independently of the integrity of the hexapeptide and, consequently, of its well-known interactor, the homeodomain protein PBX. These results hint at a potential involvement of dimerization in the complex landscape of HOX regulatory mechanisms. Full article

Two convex polyhedra that markedly resemble the head of the flatback sea turtle hatchling are identified. The first example is a zygomorphic tetragonal dodecahedron, while the other, an even better matching structure, is a related tetradecahedron, herein speculated to arise from this particular dodecahedron via known mechanisms gleaned from studies of the behavior of foams. A segmented, biomorphic, convex polyhedral model to address cephalic topology is thus presented stemming from solid geometry, anatomical observations, and a recently computed densest local packing arrangement of fifteen slightly oblate spheroids in which fourteen oblate spheroids surround a central such spheroid. This particular array of oblate spheroids shares salient structural features with the aforementioned dodecahedron. Successful testing of the model has been achieved by converting this array of fifteen oblate spheroids constructed with putty to the cephaloid dodecahedron in a process involving ventral elongation induced by stretching in the anterior direction along the anteroposterior axis (convergent extension). During convergent extension, the two left most anterolateral oblate spheroids that are in direct contact with the ventral spheroid of the array merge into a single lateral facet of the incipient dodecahedron, while the corresponding two right such oblate spheroids do the same. Thus, the fourteen outer oblate spheroids of the array give rise to the twelve facets of the finalized dodecahedron, while the central oblate spheroid remnant assumes an interior dodecahedral position. The hypothetical dodecahedron to tetradecahedron transformation entails the collapse of a tetravalent vertex (which is known to occur in foams as part of a T1 transition) followed by bilateral facet splitting. Remarkably, a model stipulating that convexity is to be retained in connection with this sequence of steps necessitates that the starting dodecahedral template undergoes modification to become a tetradecahedron in possession of precisely the highly ordered feature found at the top of the head of numerous specimens of the flatback sea turtle hatchling, namely, a fused medial pentagon–heptagon pair in the form of a pentagonal frontal scute and heptagonal frontoparietal scute. Such a possible new instance of geometric biomorphy, taken together with the correct anticipation of the cephalic pentagon–heptagon pair, might serve to instill further confidence in renewed efforts to shed light on morphogenesis with foam embryo models. Full article

The formation of embryonic axes is a critical step during animal development, which contributes to establishing the basic body plan in each particular organism. Wnt signaling pathways play pivotal roles in this fundamental process. Canonical Wnt signaling that is dependent on β-catenin regulates the patterning of dorsoventral, anteroposterior, and left–right axes. Non-canonical Wnt signaling that is independent of β-catenin modulates cytoskeletal organization to coordinate cell polarity changes and asymmetric cell movements. It is now well documented that components of these Wnt pathways biochemically and functionally interact to mediate cell–cell communications and instruct cellular polarization in breaking the embryonic symmetry. The dysfunction of Wnt signaling disrupts embryonic axis specification and proper tissue morphogenesis, and mutations of Wnt pathway genes are associated with birth defects in humans. This review discusses the regulatory roles of Wnt pathway components in embryonic axis formation by focusing on vertebrate models. It highlights current progress in decoding conserved mechanisms underlying the establishment of asymmetry along the three primary body axes. By providing an in-depth analysis of canonical and non-canonical pathways in regulating cell fates and cellular behaviors, this work offers insights into the intricate processes that contribute to setting up the basic body plan in vertebrate embryos. Full article

(1) Background: The prevention of proximal femoral fractures among people of very advanced age is relevant as they are common and increasing in number. The aim of this study was to determine if the hip axis length (HAL) and the neck-shaft angle (caput–collum–diaphyseal CCD) are risk factors for those fractures among people aged 80 years and over. Consequently, it was additionally analysed if these parameters are associated with a certain fracture type. (2) Methods: Anteroposterior radiographs of the pelvis were collected to form three groups (femoral neck fractures (FNFx), trochanteric fractures (TFx) and non-fractured femora (NFx)). Two independent blinded observers separately conducted each measurement of the HAL and CCD. Statistical analysis was performed to determine the association between the measured parameters and type of fracture. (3) Results: One hundred and fifty patients (50 per group) were examined, of which the mean age was 92.7 ± 3.5 (range 81–104) years. Both the HAL and CCD of the FNFx group were significantly larger than in the TFx group (p = 0.013, 0.003). The CCD was higher in the FNFx than that of the NFx group (p = 0.001). No further significant differences of HAL and CCD were observed between the groups. (4) Conclusions: For people aged 80 years and over, an increased HAL represented no risk factor for proximal femur fractures, and a large HAL was associated with an increased occurrence of FNFx instead of TFx. A large CCD was associated with an increased risk of suffering a femoral neck fracture, showing evidence of the CCD being a risk factor for the extremely old population. Full article

The rotational alignment of the femoral component in total knee arthroplasty (TKA) is considered an important factor, but it is still difficult to assess intraoperatively. This study was conducted to identify anatomical parameters for femoral rotational alignment. A total of 204 patients who underwent primary TKA between 2015 and 2019 were enrolled. The femoral lateral (FLAP) and femoral medial anteroposterior (FMAP) lengths were measured as the widest lengths in the anteroposterior (AP) axis after distal femoral resection. The difference between FLAP and FMAP was defined as dFAP. The concordance correlation coefficient (CCC) was assessed for agreement between the cTEA-PCA and the value of femoral rotation using the linear regression analysis equation. HKA, FLAP, FMAP, and dFAP were significantly associated with femoral rotational alignment. The prediction equation combining the novel intraoperative anatomical references showed improved association with rotational alignment. If dFAP was 6.0 mm, the femoral rotation angle was calculated as 4.9° using this univariate regression equation. The CCC was 0.483, indicating moderate agreement. The dFAP showed an association with distal femoral rotational alignment. A 6 mm dFAP could be a reference for around 5° of femoral rotation. The equation developed in this study may be a reliable tool for intraoperative distal femoral rotational alignment. Full article

Background and Objectives: To assess femoral shaft bowing (FSB) in coronal and sagittal planes and introduce the clinical implications of total knee arthroplasty (TKA) by analyzing a three-dimensional (3D) model with virtual implantation of the femoral component. Materials and Methods: Sixty-eight patients (average age: 69.1 years) underwent 3D model reconstruction of medullary canals using computed tomography (CT) data imported into Mimics^® software (version 21.0). A mechanical axis (MA) line was drawn from the midportion of the femoral head to the center of the intercondylar notch. Proximal/distal straight centerlines (length, 60 mm; diameter, 1 mm) were placed in the medullary canal’s center. Acute angles between these centerlines were measured to assess lateral and anterior bowing. The acute angle between the distal centerline and MA line was measured for distal coronal and sagittal alignment in both anteroposterior (AP) and lateral views. The diameter of curve (DOC) along the posterior border of the medulla was measured. Results: The mean lateral bowing in the AP view was 3.71°, and the mean anterior bowing in the lateral view was 11.82°. The average DOC of the medullary canal was 1501.68 mm. The average distal coronal alignment of all femurs was 6.40°, while the distal sagittal alignment was 2.66°. Overall, 22 femurs had coronal bowing, 42 had sagittal bowing, and 15 had both. Conclusions: In Asian populations, FSB can occur in coronal, sagittal, or both planes. Increased anterolateral FSB may lead to cortical abutment in the sagittal plane, despite limited space in the coronal plane. During TKA, distal coronal alignment guides the distal femoral valgus cut angle, whereas distal sagittal alignment aids in predicting femoral component positioning to avoid anterior notching. However, osteotomies along the anterior cortical bone intended to prevent notching may result in outliers due to differences between the distal sagittal alignment and the distal anterior cortical axis. Full article

Background: Long-distance running is popular but associated with a high risk of injuries, particularly toe-related injuries. Limited research has focused on preventive measures, prompting exploration into the efficacy of raised toe box running shoes. Purpose: This study aimed to investigate the effect of running shoes with raised toe boxes on preventing toe injuries caused by distance running. Methods: A randomized crossover design involved 25 male marathon runners (height: 1.70 ± 0.02 m, weight: 62.6 + 4.5 kg) wearing both raised toe box (extended by 8 mm along the vertical axis and 3 mm along the sagittal axis) and regular toe box running shoes. Ground reaction force (GRF), in-shoe displacement, and degree of toe deformation (based on the distance change between the toe and the metatarsal head) were collected. Results: Wearing raised toe box shoes resulted in a significant reduction in vertical (p = 0.001) and antero–posterior (p = 0.015) ground reaction forces during the loading phase, with a notable increase in vertical ground reaction force during the toe-off phase (p < 0.001). In-shoe displacement showed significant decreased movement in the forefoot medial (p < 0.001) and rearfoot (medial: p < 0.001, lateral: p < 0.001) and significant increased displacement in the midfoot (medial: p = 0.002, lateral: p < 0.001). Impact severity on the hallux significantly decreased (p < 0.001), while impact on the small toes showed no significant reduction (p = 0.067). Conclusions: Raised toe box running shoes offer an effective means of reducing toe injuries caused by long-distance running. Full article

Amyotrophic lateral sclerosis (ALS) is a progressive disease with a high prevalence of malnutrition that can influence prognosis. The main objective of this study is to compare the validity of muscle ultrasonography in the diagnosis of malnutrition and the prognosis of patients with ALS. Methods: This is a prospective observational study that analyzes the nutritional status of patients at the beginning of nutritional monitoring. The morphofunctional assessment included the examination of anthropometric variables such as weight, height, body mass index (BMI), arm circumference, and calf circumference. Additionally, electrical bioimpedanciometry (BIA) was used to measure electrical parameters and estimate other relevant metrics. Muscle ultrasonography^® (quadriceps rectus femoris (QRF)) assessed muscle mass parameters, including muscle area index (MARAI), anteroposterior diameter of the QRF (Y-axis) (cm), transverse diameter of the QRF (X-axis) (cm), and the sum of the quadriceps thickness (RF+VI) (cm), as well as muscle quality parameters such as echogenicity and the Y–X index. Results: A total of 37 patients diagnosed with amyotrophic lateral sclerosis (ALS) were included in this study. Of these patients, 51.4% were men. The mean age was 64.27 (12.59) years. A total of 54.1% of the patients had a bulbar onset of amyotrophic lateral sclerosis, and 45.9% had spinal onset. The percentage of subjects with malnutrition diagnosed by the Global Leadership Initiative on Malnutrition (GLIM) criteria was 45.9% of patients. There was a direct correlation between muscle mass parameters assessed by muscle ultrasonography (RF+VI) and active mass markers measured by bioimpedanciometry (body cellular mass index (BCMI) (r = 0.62; p < 0.01), fat-free mass index (FFMI) (r = 0.75; p < 0.01), and appendicular skeletal mass index (ASMI) (r = 0.69; p < 0.01)). There was a direct correlation between echogenicity and resistance (r = 0.44; p = 0.02), as well as between the fat-free mass index and the Y–X index (r = 0.36; p = 0.14). Additionally, there was a negative correlation between echogenicity and BCMI (r = −0.46; p < 0.01) and ASMI (r = 0.34; p = 0.06). Patients with low quadriceps thickness (male < 2.49 cm; female < 1.84 cm) showed an increased risk of hospital admission adjusted by age, sex, and presence of dysphagia (OR: 7.84 (CI 95%: 1.09–56.07); p-value = 0.04), and patients with low-quality mass (Y–X index < 0.35) had a higher risk of hospital admission adjusted by age, sex, and presence of dysphagia (OR: 19.83 (CI 95%: 1.77–222.46); p-value = 0.02). Conclusions: In patients with ALS, ultrasonography echogenicity was inversely related to BCMI, FFMI, and ASMI, and the Y–X index was directly related to FFMI. The lowest quartiles of quadriceps thickness and Y–X index are risk factors for hospital admission. Full article

Brain models present a viewpoint on the fundamental structural components of the brain and their mutual organization, generally relative to a particular concept of the brain axis. A model may be based on adult brain structure or on developmental morphogenetic aspects. Brain models usually have functional implications, depending on which functional properties derive from the postulated organization. This essay examines the present scenario about brain models, emphasizing the contrast between columnar or other longitudinal models and transverse subdivisional neuromeric models. In each case, the main functional implications and apparent problems are explored and commented. Particular attention is given to the modern molecularly based ‘prosomeric model’, which postulates a set of 20 transverse prosomeres as the developmental units that serve to construct all the cerebral parts and the particular typology of many different neuronal populations within the forebrain and the hindbrain, plus a number of additional spinal cord units. These metameric developmental units (serially repeated, but with unique molecular profiles) confer to this model remarkable functional properties based mainly on its multiplicity and modularity. Many important brain functions can be decomposed into subfunctions attended to by combined sets of neuronal elements derived from different neuromeres. Each neuromere may participate in multiple functions. Most aspects related to creation of precise order in neural connections (axonal navigation and synaptogenesis) and function is due to the influence of neuromeric anteroposterior and dorsoventral positional information. Research on neuromeric functionality aspects is increasing significantly in recent times. Full article

Duathlon consists of two durations of running separated by cycling in a format similar to triathlon. The addition of cycling and the associated loadings on the neuromuscular system can modify spatiotemporal variables in running including trunk motion, which can impact running economy. Changes to trunk motion can be inferred by measuring accelerations of the centre of mass (CoM). However, there is scarce research into trunk dynamics in duathlon. Therefore, the aim of this study was to use an inertial sensor (an accelerometer) to compare acceleration magnitudes of the trunk in the vertical, mediolateral, and anteroposterior directions during a simulated field-based duathlon. Specifically, running performance and magnitudes of trunk acceleration were compared pre and post a cycling load. Ten well-trained duathletes (seven males, three females (mean ± SD; age: 31.1 ± 3.4 years; body mass: 70.9 ± 6.9 kg; body height: 177 ± 5.82 cm; 9.45 ± 1.7 weekly training hours per week; 9.15 ± 5.2 years training experience)) completed a 5 km run performed at a self-selected pace (described as moderate intensity) prior to 20 km of continuous cycling at four varied cadence conditions. This was immediately followed by a 2.5 km run. Mean completion times for the final 2.5 km in running pre-cycling (4.03:05 ± 0.018) compared to the 2.5 km in running post-cycling (4.08:16 ± 0.024) were significantly different. Regarding trunk acceleration, the largest difference was seen in the vertical direction (y axis) as greater magnitudes of acceleration occurred during the initial 1 km of running post-cycling combined with overall significant alterations in acceleration between running pre- and post-cycling (p = 0.0093). The influence of prior cycling on trunk acceleration activity in running likely indicates that greater vertical and mediolateral trunk motion contributes to decremental running performance. In future, further advanced simulation and analysis could be performed in ecologically valid contexts whereby multiple accelerometers might be used to model a more complete set of dynamics. Full article

(1) Background: The aim of this prospective study was to evaluate measurement software in comparison with manual measurements using inter-observer and intra-observer variability on radiographs in the preoperative planning of total knee arthroplasty. (2) Methods: Two independent observers retrospectively measured the mechanical lateral proximal femoral angle (mLPFA), the mechanical lateral distal femoral angle (mLDFA), the joint line convergence angle (JLCA), the mechanical medial proximal tibial angle (mMPTA), the mechanical lateral distal tibial angle (mLDTA), the hip–knee angle or mechanical tibial–femoral axis angle (HKA), and the anatomical–mechanical angle (AMA) on 55 long-leg anteroposterior radiographs manually twice, followed by measurements using dedicated software. Variability between manual and computer-aided planning was assessed, and all measurements were performed a second time after 14 days in order to assess intra-observer variability. (3) Results: Concerning intra-observer variability, no statistically significant difference was observed regarding the software-based measurements. However, significant differences were noted concerning intra-observer variability when measuring the mLDFA and AMA manually. Testing for statistical significance regarding variability between manual and software-based measurements showed that the values varied strongly between manual and computer-aided measurements. Statistically significant differences were detected for mLPFA, mLDFA, mMPTA, and mLPTA on day 1, and mLPFA, mMPTA, and mLPTA on day 15, respectively. (4) Conclusions: Preoperative planning of leg axis angles and alignment using planning software showed less inter- and intra-observer variability in contrast to manual measurements, and results differed with respect to manual planning. We believe that the planning software is more reliable and faster, and we would recommend its use in clinical settings. Full article

Purpose: There is lack of intraoperative consensus on the distal femur anterior resected surface shape that allows reliable rotational alignment assessment during total knee arthroplasty (TKA). We aimed to evaluate the ratio and prevalence of anterior femoral resection surface intraoperatively. Materials and Methods: The study included 234 osteoarthritis patients with varus knees and not valgus knees or deformities. After conventional medial parapatellar approach, measured resection technique based on the mechanical axis of the femur and preoperative TEA-PCA angle on CT with anterior reference was used among all the patients. The anteroposterior (AP) lengths after distal femoral resection were measured as the femoral lateral AP (FLAP) and femoral medial AP (FMAP) lengths. Based on the medial (MD) and lateral condyle (LD) vertical distance ratios of the femur anterior resected surface, the groups were classified into “boot sign”, “grand-piano”, and “butterfly sign” groups. For comparison of the mean values, the data were assessed for normality with the Shapiro–Wilk test. One-way ANOVA with post hoc analysis using Tukey’s honestly significant difference (HSD) test was used to compare the mean values among the groups. The correlations between the MD/LD and variables were analyzed using the Pearson correlation coefficient. Linear regression analyses were used to find the associated factors to the anterior femoral resection surface shape. Results: Mean intraoperative femoral rotation and distal femoral cutting angles were 4.9° ± 1.2 and valgus 5.0° ± 0.7, respectively. Mean FLAP was 52.9 ± 4.2 mm. Mean MD/LD (0.61 ± 0.13) was lower than that of typical “grand-piano sign”. The morphological shape incidence of the “boot sign” was 62.4%. In the “boot sign” group, the FLAP was found to be smaller than that in the other groups (52.4 ± 4.2 vs. 53.7 ± 4.2 vs. 54.9 ± 2.7; p = 0.02), while the intraoperative femoral rotation angle was found to be larger than in the other groups (5.0 ± 1.2 vs. 4.6 ± 1.1 vs. 4.7 ± 1.2; p = 0.039). The MD/LD-associated factors were FLAP, intraoperative femoral rotation, and distal femoral cutting angles (R² = 0.268). Conclusion: The femur anterior resection surface shape in TKA was found in the “boot sign” rather than the “grand-piano sign” in Korean ethnics owing to an asymmetric morphology of femoral condyles. Ethnic differences, including distal femoral morphology, should be considered for assessment of the femoral rotation angle using the femur anterior resection surface shape. Full article

Immersive Virtual Reality (VR) systems are expanding as sensorimotor readaptation tools for older adults. However, this purpose may be challenged by cybersickness occurrences possibly caused by sensory conflicts. This study aims to analyze the effects of aging and multisensory data fusion processes in the brain on cybersickness and the adaptation of postural responses when exposed to immersive VR. Methods: We repeatedly exposed 75 participants, aged 21 to 86, to immersive VR while recording the trajectory of their Center of Pressure (CoP). Participants rated their cybersickness after the first and fifth exposure. Results: The repeated exposures increased cybersickness and allowed for a decrease in postural responses from the second repetition, i.e., increased stability. We did not find any significant correlation between biological age and cybersickness scores. On the contrary, even if some postural responses are age-dependent, a significant postural adaptation occurred independently of age. The CoP trajectory length in the anteroposterior axis and mean velocity were the postural parameters the most affected by age and repetition. Conclusions: This study suggests that cybersickness and postural adaptation to immersive VR are not age-dependent and that cybersickness is unrelated to a deficit in postural adaptation or age. Age does not seem to influence the properties of multisensory data fusion. Full article