Atomic force microscopy for biomechanical and structural analysis of human dermis: A complementary tool for medical diagnosis and therapy monitoring

Skin mechanical properties are usually measured considering the entire skin thickness and very little is known about the mechanical behaviour of individual skin layers. We propose atomic force microscopy (AFM) as a tool to quantify nanoscale changes in the biomechanical properties and ultrastructure of human papillary dermis exposed to different mechanical and physical stimuli. Samples from 3 human skin biopsies were studied: one stretched by obesity, one subjected to a high level of sun exposure and normal skin as control. Slices of the papillary dermis layer were harvested at controlled depths from each skin biopsy and 25 μm² areas of each slice were imaged and D‐periodicity of collagen fibres measured by AFM, together with their stiffness. Standard histological analysis was also carried out to correlate biochemical properties and their distribution with stiffness and topography. We obtained similar stiffness values between the sample affected by obesity and the control sample at any depth level into the dermis, while the sun‐exposed sample presented a significantly lower stiffness. Additionally, all samples presented an increase in the stiffness at higher depths into the papillary dermis layer. Collagen fibres close to the epidermis of sample affected either by obesity and sun exposure—the former even more than the latter—are thicker and present a larger D‐period than those in the control sample. Our results open the possibility to use structural and mechanical analysis based on AFM as a complementary tool for medical diagnosis and therapy monitoring.     

Sinus node dysfunction in catecholaminergic polymorphic ventricular tachycardia: Risk factor and potential therapeutic target?

Catecholaminergic polymorphic ventricular tachycardia (CPVT) is an inherited heart rhythm disorder characterized by the occurrence of potentially life-threatening polymorphic ventricular tachyarrhythmias in conditions of physical or emotional stress. The underlying cause is a dysregulation in intracellular Ca handling due to mutations in the sarcoplasmic reticulum Ca release unit. Recent experimental work suggests that sinus bradycardia, which is sometimes observed in CPVT patients, may be another primary defect caused by CPVT mutations. Herein, we review the pathophysiology of CPVT and discuss the role of sinus node dysfunction as a modulator of arrhythmia risk and potential therapeutic target.     

Assessment of patient's pain-related behavior at physical examination may allow diagnosis of recent osteoporotic vertebral fracture

Background contextAlthough innumerable studies have analyzed the multiple aspects of osteoporotic vertebral fractures, no study has focused on the clinical features related to spine pain in patients with recent osteoporotic vertebral compression fractures (VCFs).PurposeTo determine whether the assessment of pain-related behavior (P-RB) of patients with osteoporotic VCFs of recent onset may allow the fracture to be strongly suspected, or even diagnosed, at physical examination.Study designPain-related behavior of elderly patients attending an outpatient spine clinic was evaluated on the basis of six consecutive movements made on the examining table.Patient sampleFifty-six patients complaining only of lumbar or thoracic pain. The fractured patients (FPs), representing the fracture group (FG), were the 19 who had a recent VCF, whereas the control group (CG) consisted of the remaining 37 patients.MethodsAssessment of P-RB was based on six parameters: grimacing, sighing, clenching or blocking eyelids, gaping or strongly tightening the lips, need for help to take positions, and extreme difficulty to turn in the prone position. A score of 1 or a decimal was assigned to each parameter, the final score to each patient being 0 to 6. Three types of injury, acute (I), subacute (II), or chronic (III), were identified on the basis of the time elapsed from the probable occurrence of the fracture. The diagnosis of recent fracture was based on magnetic resonance images. Patients were videotaped during their movements. An examiner, unaware of the clinical history and diagnosis, gave a P-RB score to all patients and indicated whether they had to be placed in FG or CG, and also their presumable type of fracture. Subsequently, a DVD with the videotapes of all patients was given to three independent examiners, not specifically expert of spine conditions, who were asked to make the same evaluations as the first examiner.ResultsThe mean scores for P-RB given by the first examiner were 4.6 to FG and 0.7 to CG (p<.01). He identified as FPs 89% of those who were in FG. The type of fracture was indicated correctly in 88% of patients identified as FPs. The mean scores for the three types of fracture ranged from 5.4 (Type I) to 3.3 (Type III) (p<.001). The mean scores for P-RB given by the independent examiners to FG and CG were similar to those of the first examiner. The rates of correctness in identifying the type of fracture in patients indicated as FPs varied from 87% to 80%. The mean scores assigned to the patients included in the three types of fracture ranged from 5.4 to 2.8.ConclusionsPain-related behavior evaluation of patients with osteoporotic VCF during their movements on the examining table may allow to suspect, or even diagnose, the presence of a fracture, particularly in the initial 4 to 6 weeks after the occurrence. Even orthopedic surgeons not particularly familiar with spine care may be able to suspect the injury during physical examination.     

Fibrous Dysplasia of the Maxilla: Diagnostic Reliability of the Study Image. Literature Review

Objective Fibrous dysplasia (FD) is a benign bone disorder in facial bones. This study evaluates the possibility of diagnosing fibrous dysplasia on imaging alone, without biopsy of the lesion, which is often burdensome for the patient. Materials and Methods The authors bring their experience of four cases of bone lesions of the maxillofacial region and present a review of published studies. The imaging techniques evaluated are computed tomography (CT) and magnetic resonance imaging (MRI) with and without contrast. Results The literature review demonstrates that it is impossible to make diagnosis of fibrous dysplasia exclusively by imaging. Radiographic images often show a ground-glass appearance, which is characteristic but not pathognomonic of fibrous dysplasia. Conclusion Although CT and MRI images may in many cases suggest a diagnosis of fibrous dysplasia, histological examination or follow-up imaging should follow.     

Notch signaling deregulation in multiple myeloma: A rational molecular target

Despite recent therapeutic advances, multiple myeloma (MM) is still an incurable neoplasia due to intrinsic or acquired resistance to therapy. Myeloma cell localization in the bone marrow milieu allows direct interactions between tumor cells and non-tumor bone marrow cells which promote neoplastic cell growth, survival, bone disease, acquisition of drug resistance and consequent relapse. Twenty percent of MM patients are at high-risk of treatment failure as defined by tumor markers or presentation as plasma cell leukemia. Cumulative evidences indicate a key role of Notch signaling in multiple myeloma onset and progression. Unlike other Notch-related malignancies, where the majority of patients carry gain-of-function mutations in Notch pathway members, in MM cell Notch signaling is aberrantly activated due to an increased expression of Notch receptors and ligands; notably, this also results in the activation of Notch signaling in surrounding stromal cells which contributes to myeloma cell proliferation, survival and migration, as well as to bone disease and intrinsic and acquired pharmacological resistance. Here we review the last findings on the mechanisms and the effects of Notch signaling dysregulation in MM and provide a rationale for a therapeutic strategy aiming at inhibiting Notch signaling, along with a complete overview on the currently available Notch-directed approaches.     

Can cyclin-dependent kinase 4/6 inhibitors convert inoperable breast cancer relapse to operability? A case report

BACKGROUND Pathological complete response(pCR) is rare in hormone receptor-positive(HR+)HER2-negative breast cancer(BC) treated with either endocrine therapy(ET) or chemotherapy. Radical resection of locoregional relapse, although potentially curative in some cases, is challenging when the tumor invades critical structures.The oral cyclin-dependent kinase 4/6 inhibitor palbociclib in combination with ET has obtained a significant increase in objective response rates and progression-free survival in patients with advanced BC and is now being evaluated in the neoadjuvant setting. We present a clinical case of a patient with an inoperable locoregional relapse of HR+ HER2-negative BC who experienced p CR after treatment with palbociclib.CASE SUMMARY We report the clinical case of a 60-year-old patient who presented with an inoperable locoregional relapse of HR+, HER2-negative BC 10 years after the diagnosis of the primary tumor. During a routine follow-up visit, breast magnetic resonance imaging and positron emission tomography/computed tomography revealed a 4-cm lesion in the right subclavicular region, infiltrating the chest wall and extending to the subclavian vessels, but without bone or visceral involvement. Treatment was begun with palbociclib plus letrozole, converting the disease to operability over a period of 6 mo. Surgery was performed and a p CR achieved. Of note, during treatment the patient experienced a very uncommon toxicity characterized by burning tongue and glossodynia associated with dysgeusia, paresthesia, dysesthesia, and xerostomia. A reduction in the dose of palbociclib did not provide relief and treatment with the inhibitor was thus discontinued, resolving the tongue symptoms. Laboratory exams were unremarkable. Given that this was a late relapse, the tumor was classified asendocrine-sensitive, a condition associated with high sensitivity to palbociclib.CONCLUSION This case highlights the potential of the cyclin-dependent kinase 4/6 inhibitor plus ET combination to achieve pCR in locoregional relapse of BC, enabling surgical resection of a lesion initially considered inoperable.