RESUMO
Botulinum toxin-A (BTX-A), a neurotoxin produced by Clostridium botulinum, was assessed for relieving implant-related pectoralis major muscle's painful spasms. In detail, 100 units of BTX-A can reduce muscle activity and, as a consequence, muscle spasms. The latter is considered the leading cause of post-operative pain after the sub-pectoral tissue expansion, sometimes leading to early expanders' removal. In addition, women choosing post-mastectomy reconstruction surgery seem to suffer worse post-operative pain than those who stop at the mastectomy stage. However, there is no unanimous consensus concerning the potential benefits of BTX-A in reducing pain related to the sub-pectoral placement of tissue expanders in breast reconstruction due to the exiguity of evidence. Therefore, this review aims to describe BTX-A-related evidence in this reconstruction setting. NO LEVEL ASSIGNED: This journal requires that authors assign a level of evidence to each submission to which Evidence-Based Medicine rankings are applicable. This excludes Review Articles, Book Reviews, and manuscripts that concern Basic Science, Animal Studies, Cadaver Studies, and Experimental Studies. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .
RESUMO
Light-driven modulation of neuronal activity at high spatial-temporal resolution is becoming of high interest in neuroscience. In addition to optogenetics, nongenetic membrane-targeted nanomachines that alter the electrical state of the neuronal membranes are in demand. Here, we engineered and characterized a photoswitchable conjugated compound (BV-1) that spontaneously partitions into the neuronal membrane and undergoes a charge transfer upon light stimulation. The activity of primary neurons is not affected in the dark, whereas millisecond light pulses of cyan light induce a progressive decrease in membrane resistance and an increase in inward current matched to a progressive depolarization and action potential firing. We found that illumination of BV-1 induces oxidation of membrane phospholipids, which is necessary for the electrophysiological effects and is associated with decreased membrane tension and increased membrane fluidity. Time-resolved atomic force microscopy and molecular dynamics simulations performed on planar lipid bilayers revealed that the underlying mechanism is a light-driven formation of pore-like structures across the plasma membrane. Such a phenomenon decreases membrane resistance and increases permeability to monovalent cations, namely, Na+, mimicking the effects of antifungal polyenes. The same effect on membrane resistance was also observed in nonexcitable cells. When sustained light stimulations are applied, neuronal swelling and death occur. The light-controlled pore-forming properties of BV-1 allow performing "on-demand" light-induced membrane poration to rapidly shift from cell-attached to perforated whole-cell patch-clamp configuration. Administration of BV-1 to ex vivo retinal explants or in vivo primary visual cortex elicited neuronal firing in response to short trains of light stimuli, followed by activity silencing upon prolonged light stimulations. BV-1 represents a versatile molecular nanomachine whose properties can be exploited to induce either photostimulation or space-specific cell death, depending on the pattern and duration of light stimulation.
Assuntos
Neurônios , Neurônios/efeitos dos fármacos , Neurônios/metabolismo , Animais , Membrana Celular/metabolismo , Membrana Celular/química , Luz , Bicamadas Lipídicas/química , Simulação de Dinâmica Molecular , Ratos , Camundongos , OptogenéticaRESUMO
INTRODUCTION: Gigantomastia, characterized by excessive breast size (usually heavier than 2.5 kg), can result from various causes and significantly affect patients' lives. Surgical intervention is often required, and over time, several techniques have been developed for its treatment. These techniques aim to address the functional and aesthetic concerns associated with gigantomastia, providing relief to patients and improving their quality of life. PRESENTATION OF THE CASE: A 40-year-old primiparous housewife developed unilateral gigantomastia as a consequence of hormone therapy. To address this, a modified reduction mammoplasty procedure was undertaken, incorporating NAC (Nipple-Areola Complex) grafting. The reduction involved removing 3450 g of tissue, resulting in restored breast symmetry and enabling the patient to reintegrate into normal daily life. DISCUSSION: Compared to the traditional technique, the introduction of some modifications in the design allowed for the absence of complications such as dehiscence of the scar at the intersection of the T, the failure of the nipple graft attachment, and the maintenance of a conical shape over time, enabling complete symmetrization of the two breasts. CONCLUSION: The use of a modified version of the Thorek technique allowed for optimal functional and aesthetic restoration even in the case of a significantly disproportionate breast compared to the contralateral one, with no complications.