A simple and effective 1D-element discrete-based method for computational bone remodeling.

In-silico models applied to bone remodeling are widely used to investigate bone mechanics, bone diseases, bone-implant interactions, and also the effect of treatments of bone pathologies. This article proposes a new methodology to solve the bone remodeling problem using one-dimensional (1D) elements to discretize trabecular structures more efficiently for 2D and 3D domains. An Euler integration scheme is coupled with the momentum equations to obtain the evolution of material density at each step. For the simulations, the equations were solved by using the finite element method, and two benchmark tests were solved varying mesh parameters. Proximal femur and calcaneus bone were selected as study cases given the vast research available on the topology of these bones, and compared with the anatomical features of trabecular bone reported in the literature. The presented methodology has proven to be efficient in optimizing topologies of lattice structures; It can predict the trend of formation patterns of the main trabecular groups from two different cancellous bones (femur and calcaneus) using domains set up by discrete elements as a starting point. Preliminary results confirm that the proposed approach is suitable and useful in bone remodeling problems leading to a considerable computational cost reduction. Characteristics similar to those encountered in topological optimization algorithms were identified in the benchmark tests as well, showing the viability of the proposed approach in other applications such as bio-inspired design.

Interacción con pantalla táctil de smartphone en pacientes con temblor esencial y sujetos sanos / Interaction with touchscreen smartphones in patients with essential tremor and healthy individuals

Introducción: El uso de smartphones en investigación biomédica está creciendo rápidamente en diferentes entornos clínicos. Realizamos un estudio piloto para obtener información sobre el uso de smartphones en pacientes con temblor esencial (TE) y en sujetos sanos, con el objetivo de evaluar si la realización de diversas tareas con las pantallas táctiles difiere entre grupos y describir factores de esta interacción.MétodoSe administró un cuestionario sobre el uso de smartphones a 31 pacientes con TE y 40 sujetos control apareados por edad y sexo. Acto seguido, los participantes interactuaron con una aplicación Android en desarrollo y realizaron 4 test basados en diferentes modos de interacción típicos con pantallas táctiles, con 5 repeticiones de cada tarea.ResultadoLos tipos de uso de smartphones así como su interacción no fueron significativamente diferentes entre pacientes y controles. La edad y el número de usos del smartphone son factores clave en esta interacción con pantallas táctiles.ConclusiónEstas observaciones apoyan el uso de las pantallas táctiles de los smartphones para investigación en TE, pero se requieren más estudios. (AU)

Introduction: Smartphones use in biomedical research is becoming more prevalent in different clinical settings. We performed a pilot study to obtain information on smartphone use by patients with essential tremor (ET) and healthy controls, with a view to determining whether performance of touchscreen tasks is different between these groups and describing touchscreen interaction factors.MethodA total of 31 patients with ET and 40 sex- and age-matched healthy controls completed a descriptive questionnaire about the use of smartphones. Participants subsequently interacted with an under-development Android application, and performed 4 tests evaluating typical touchscreen interaction gestures; each test was performed 5 times.ResultThe type of smartphone use and touchscreen interaction were not significantly different between patients and controls. Age and frequency of smartphone use are key factors in touchscreen interaction.ConclusionOur results support the use of smartphone touchscreens for research into ET, although further studies are required. (AU)

Interaction with touchscreen smartphones in patients with essential tremor and healthy individuals.

INTRODUCTION: Smartphone use in biomedical research is becoming more prevalent in different clinical settings. We performed a pilot study to obtain information on smartphone use by patients with essential tremor (ET) and healthy controls, with a view to determining whether performance of touchscreen tasks is different between these groups and describing touchscreen interaction factors. METHOD: A total of 31 patients with ET and 40 sex- and age-matched healthy controls completed a descriptive questionnaire about the use of smartphones. Participants subsequently interacted with an under-development Android application, and performed 4 tests evaluating typical touchscreen interaction gestures; each test was performed 5 times. RESULT: The type of smartphone use and touchscreen interaction were not significantly different between patients and controls. Age and frequency of smartphone use are key factors in touchscreen interaction. CONCLUSION: Our results support the use of smartphone touchscreens for research into ET, although further studies are required.

Optical coherence tomography in diagnosis of inflammatory scalp disorders.

BACKGROUND: The common inflammatory scalp disorders share similar clinical manifestations, and patient work up require invasive, undesirable diagnostic procedures like biopsy to ensure correct diagnosis. Optical coherence tomography (OCT) is a non-invasive high-resolution imaging modality that has found a valuable tool to assist in the diagnose and evaluation of different skin diseases. OBJECTIVES: To describe the structural and vascular dynamic OCT (D-OCT) findings of inflammatory scalp disorders including scalp psoriasis, seborrhoeic dermatitis and contact dermatitis and to compare trichoscopy and OCT features. METHODS: Subjects with diagnosis of seborrhoeic dermatitis, psoriasis or contact dermatitis were enrolled in this study. OCT scans were taken on involved scalp, and the same scalp regions were evaluated by trichoscopy and compared with healthy scalp. RESULTS: A total of fourteen subjects (two healthy controls, four seborrhoeic dermatitis, five psoriasis and three contact dermatitis) participated. D-OCT imaging of vascular pattern in healthy scalp and the inflammatory scalp disorders were described. D-OCT images could enhance the clinician's ability to distinguish psoriasis from seborrhoeic dermatitis by objectively detect and assess red loop density. In scalp contact dermatitis, the vessels of the deep plexus were more dilated and fewer in number than those found in seborrhoeic dermatitis. CONCLUSION: Dynamic OCT provides information that more clearly elucidates changes at the level of the superficial and deep plexuses without invasively interfering with superficial structures. In the context of inflammatory scalp disorders, this is useful to discern disorders with overlapping symptoms and minimize the use of invasive biopsies to diagnose.

Interaction with touchscreen smartphones in patients with essential tremor and healthy individuals. / Interacción con pantalla táctil de smartphone en pacientes con temblor esencial y sujetos sanos.

INTRODUCTION: Smartphones use in biomedical research is becoming more prevalent in different clinical settings. We performed a pilot study to obtain information on smartphone use by patients with essential tremor (ET) and healthy controls, with a view to determining whether performance of touchscreen tasks is different between these groups and describing touchscreen interaction factors. METHOD: A total of 31 patients with ET and 40 sex- and age-matched healthy controls completed a descriptive questionnaire about the use of smartphones. Participants subsequently interacted with an under-development Android application, and performed 4 tests evaluating typical touchscreen interaction gestures; each test was performed 5 times. RESULT: The type of smartphone use and touchscreen interaction were not significantly different between patients and controls. Age and frequency of smartphone use are key factors in touchscreen interaction. CONCLUSION: Our results support the use of smartphone touchscreens for research into ET, although further studies are required.

Optical coherence tomography for the investigation of frontal fibrosing alopecia.

BACKGROUND: Frontal fibrosing alopecia (FFA) is a cicatricial alopecia that affects the frontotemporal hairline, eyebrows and body hair. OCT is a non-invasive imaging technique useful in understanding skin architecture and vascularization. OBJECTIVE: To describe structural and vascular findings in FFA using OCT. METHODS: This was a case-control study conducted from the months of December 2016-February 2017. The study was IRB approved and conducted at the University of Miami Hospital outpatient dermatology hair and nail clinic in Miami, FL. Four patients with biopsy proven FFA, and three healthy age and sex-matched controls participated. OCT scans were taken on cicatricial alopecic band, inflammatory hairline, eyebrow, uninvolved scalp, facial papules, glabellar red dots and arm. The same body regions were evaluated in controls. RESULTS: Patients and controls were women aged 42-66. Results reveal epidermal thickness is increased in the inflammatory hairline (0.13 mm) and decreased in the alopecic band (0.08 mm) compared to controls (0.10 mm). Attenuation coefficient increased the inflammatory hairline and decreased in the alopecic band compared to controls. Vascular flow in the alopecic band is decreased compared to inflammatory scalp and controls in the superficial levels, but increased at deeper levels as compared to controls. Inflammatory tissue is consistently more vascular at all levels (P < 0.01). Vascular flows in each stage are significantly different than one another (P < 0.01). CONCLUSIONS: Increased vascular flow of the deep plexus in cicatricial stages can be a consequence of superficial tissue ischaemia or fibrosis. It is difficult to establish if the increased flow in the inflammatory stage is due to neovascularization as seen in other ischaemic diseases or is the result of the inflammatory response. OCT may be a useful non-invasive tool in imaging FFA. Not only can the technology assist in monitoring disease activity in a non-invasive manner, but it may elucidate new pathophysiologic findings.

The OCT4 pseudogene POU5F1B is amplified and promotes an aggressive phenotype in gastric cancer.

POU5F1B (POU domain class 5 transcription factor 1B), a processed pseudogene that is highly homologous to OCT4, was recently shown to be transcribed in cancer cells, but its clinical relevance and biological function have remained unclear. We now show that POU5F1B, which is located adjacent to MYC on human chromosome 8q24, is frequently amplified in gastric cancer (GC) cell lines. POU5F1B, but not OCT4, was also found to be expressed at a high level in GC cell lines and clinical specimens. In addition, the DNA copy number and mRNA abundance for POU5F1B showed a positive correlation in both cancer cell lines and GC specimens. Overexpression of POU5F1B in GC cells promoted colony formation in vitro as well as both tumorigenicity and tumor growth in vivo, and these effects were enhanced in the additional presence of MYC overexpression. Furthermore, knockdown of POU5F1B expression with a short hairpin RNA confirmed a role for the endogenous pseudogene in the promotion of cancer cell growth in vitro and tumor growth in vivo. POU5F1B overexpression induced upregulation of various growth factors in GC cells as well as exhibited mitogenic, angiogenic and antiapoptotic effects in GC xenografts. Finally, amplification of POU5F1B was detected in 17 (12%) of 145 cases of GC and was a significant predictor of poor prognosis in patients with stage IV disease. In conclusion, we found that the POU5F1B pseudogene is amplified and expressed at a high level in, as well as confers an aggressive phenotype on, GC, and that POU5F1B amplification is associated with a poor prognosis in GC patients.

Activin A inhibits vascular endothelial cell growth and suppresses tumour angiogenesis in gastric cancer.

BACKGROUND: Activin A is a multi-functional cytokine belonging to the transforming growth factor-ß (TGF-ß) superfamily; however, the effect of activin A on angiogenesis remains largely unclear. We found that inhibin ß A subunit (INHBA) mRNA is overexpressed in gastric cancer (GC) specimens and investigated the effect of activin A, a homodimer of INHBA, on angiogenesis in GC. METHODS: Anti-angiogenic effects of activin A via p21 induction were evaluated using human umbilical vein endothelial cells (HUVECs) in vitro and a stable INHBA-introduced GC cell line in vivo. RESULTS: Compared with TGF-ß, activin A potently inhibited the cellular proliferation and tube formation of HUVECs with induction of p21. A promoter assay and a chromatin immunoprecipitation assay revealed that activin A directly regulates p21 transcriptional activity through Smads. Stable p21-knockdown significantly enhanced the cellular proliferation of HUVECs. Notably, stable p21-knockdown exhibited a resistance to activin-mediated growth inhibition in HUVECs, indicating that p21 induction has a key role on activin A-mediated growth inhibition in vascular endothelial cells. Finally, a stable INHBA-introduced GC cell line exhibited a decrease in tumour growth and angiogenesis in vivo. CONCLUSION: Our findings highlight the suppressive role of activin A, unlike TGF-ß, on tumour growth and angiogenesis in GC.

Multicentric observational study of pain after the use of a self-gripping lightweight mesh.

INTRODUCTION: Investigation in the field of inguinal hernia surgery is now focused on postoperative pain. The extended use of lightweight meshes and alternative methods of fixation may play a relevant role in the reduction of pain. In this study, a new self-gripping lightweight polypropylene mesh is tested. METHODS: A multicentric, observational study was scheduled to prospectively evaluate this new mesh. Ten centers agreed to participate. Only primary, type 1 or 2 uncomplicated hernias in adults were included. The mesh was placed as a Lichtenstein procedure without any fixation. A complete pain questionnaire was followed at 1 week, and at 1, 3 and 6 months postoperatively. The principal goal of the study was to evaluate maximum pain score at 6 months. Pain was assessed by a visual analog scale. A total of 256 patients were operated. Mean operative time was 35.6 min; 76.2% of patients were operated in an ambulatory setting. RESULTS: There were a few postoperative complications: 2 wound infections, 17 seromas, 21 hematomas, 6 orchitis. The incidence of acute pain was 27.3% at week 1 and 7.5% at month 1. The incidence of chronic pain was 3.6% at month 3 and 2.8% at month 6. No recurrences or long-term complications were observed. CONCLUSION: This self-gripping mesh can be used safely in type 1 and 2 primary, uncomplicated inguinal hernia with minimal morbidity and most patients under ambulatory setting. The registered incidence of chronic pain is lower than 3%.

The femoral nerve in the repair of inguinal hernia: well worth remembering.

Injury to the nerves after inguinal hernia surgery is uncommon. The femoral nerve may be damaged by suture or staples, tissue scar entrapment, local anesthesia blockade or direct compression. We present a case of a transient lesion of the femoral nerve after mesh hernioplasty for a re-recurrent inguinal hernia, confirmed by radiological studies, electrophysiology and clinical recovery. The diagnosis, mechanism of injury and surgical approach are reviewed. Surgery to a recurrent hernia may be underestimated. The role of electromyography nerve conducting studies is emphasized insisting on the importance of clinical evolution for the successful management of these infrequent injuries.

Elevated protein kinase C betaII is an early promotive event in colon carcinogenesis.

Protein kinase C (PKC) has been implicated in colon carcinogenesis in humans and in rodent models. However, little is known about the specific role of individual PKC isozymes in this process. We recently demonstrated that elevated expression of PKC betaII in the colonic epithelium induces hyperproliferation in vivo (N. R. Murray et al., J. Cell Biol., 145: 699-711, 1999). Because hyperproliferation is a major risk factor for colon cancer, we assessed whether specific alterations in PKC betaII expression occur during azoxymethane-induced colon carcinogenesis in mice. An increase in PKC betaII expression was observed in preneoplastic lesions (aberrant crypt foci, 3.7-fold) compared with saline-treated animals, and in colon tumors (7.8-fold; P = 0.011) compared with uninvolved colonic epithelium. In contrast, PKC alpha and PKC betaI (a splicing variant of PKC betaII) expression was slightly decreased in aberrant crypt foci and dramatically reduced in colon tumors. Quantitative reverse transcription-PCR analysis revealed that PKC mRNA levels do not directly correlate with PKC protein levels, indicating that PKC isozyme expression is likely regulated at the posttranscriptional/translational level. Finally, transgenic mice expressing elevated PKC betaII in the colonic epithelium exhibit a trend toward increased colon tumor formation after exposure to azoxymethane. Taken together, our results demonstrate that elevated expression of PKC betaII is an important early, promotive event that plays a role in colon cancer development.