In vivo multiphoton microscopy beyond 1 mm in the brain

The ability to visualize deep brain structures in vivo with high spatial resolution is of rising interest to investigate neuronal physiology and cerebral vasculature. Optical imaging offers non-invasive, high-resolution in vivo microscopy techniques to observe brain tissue and its surrounding environment. Two-photon fluorescence laser- scanning microscopy (2PM) can overcome depth limitations by using nonlinear excitation. The ideal approach for deep imaging in brain is to use both high energy pulses and longer excitation wavelengths. Please click Additional Files below to see the full abstract

Teledermatología sincrónica en tiempos de Covid-19. Percepción del dermatólogo

Teledermatology (TD) is a remote medical care tool that experienced a great boom during the COVID19 pandemic, resulting in an increase in both, the number of remote consultations and the number of dermatologists who practice it. Several studies have reported a high degree of satisfaction among patients attended by this method. However, few studies have done so in dermatologists. We set out to investigate the experience of Chilean dermatologists with the tool by means of an online survey. Results. A total of 156 surveys were completed. The number of dermatologists using TD increased from 19.9% to 80.8% during the pandemic. They cited the absence of the physical examination-dermatoscopy as the main limitation to developing TD and reported feeling more comfortable with some pathologies. Dermatologists feel moderately comfortable and confident with the tool, however, they experienced varying degrees of stress and frustration. Only 40.8% plan to continue using TD in the future. Conclusion. Synchronous TD has clear limitations, however, these should emerge as an opportunity to consider in its development and its platforms, in order to generate a more comfortable tool for more dermatologists and thus extend its use, as an important tool for equal access to health care in Chile

PRIM: Proximity imaging of green fluorescent protein-tagged polypeptides

We report a serendipitous discovery that extends the impressive catalog of reporter functions performed by green fluorescent protein (GFP) or its derivatives. When two GFP molecules are brought into proximity, changes in the relative intensities of green fluorescence emitted upon excitation at 395 vs. 475 nm result. These spectral changes provide a sensitive ratiometric index of the extent of self-association that can be exploited to quantitatively image homo-oligomerization or clustering processes of GFP-tagged proteins in vivo. The method, which we term proximity imaging (PRIM), complements fluorescence resonance energy transfer between a blue fluorescent protein donor and a GFP acceptor, a powerful method for imaging proximity relationships between different proteins. However, unlike fluorescence resonance energy transfer (which is a spectral interaction), PRIM depends on direct contact between two GFP modules, which can lead to structural perturbations and concomitant spectral changes within a module. Moreover, the precise spatial arrangement of the GFP molecules within a given dimer determines the magnitude and direction of the spectral change. We have used PRIM to detect FK1012-induced dimerization of GFP fused to FK506-binding protein and clustering of glycosylphosphatidylinositol-anchored GFP at cell surfaces