Method for measurement of collagen monomer orientation in fluorescence microscopy.

SIGNIFICANCE: Collagen is the most abundant protein in vertebrates and is found in tissues that regularly experience tension, compression, and shear forces. However, the underlying mechanism of collagen fibril formation and remodeling is poorly understood. AIM: We explore how a collagen monomer is visualized using fluorescence microscopy and how its spatial orientation is determined. Defining the orientation of collagen monomers is not a trivial problem, as the monomer has a weak contrast and is relatively small. It is possible to attach fluorescence tags for contrast, but the size is still a problem for detecting orientation using fluorescence microscopy. APPROACH: We present two methods for detecting a monomer and classifying its orientation. A modified Gabor filter set and an automatic classifier trained by convolutional neural network based on a synthetic dataset were used. RESULTS: By evaluating the performance of these two approaches with synthetic and experimental data, our results show that it is possible to determine the location and orientation with an error of ∼37 deg of a single monomer with fluorescence microscopy. CONCLUSIONS: These findings can contribute to our understanding of collagen monomers interaction with collagen fibrils surface during fibril formation and remodeling.

Síndrome de linfocitosis infiltrativa difusa con neumonía intersticial en un paciente con VIH / Diffuse infiltrative lymphocytosis syndrome with interstitial pneumonia in a patient with HIV

El síndrome de linfocitosis infiltrativa difusa se produce en asociación con la infección por virus de la inmunodeficiencia humana; requiere cumplir con los criterios diagnósticos y descartar otras patologías infecciosas y autoinmunes. Se presenta el caso de una mujer de 47 años que consultó por edema parotídeo bilateral, síndrome sicca, tos y síndrome de impregnación. Se observó en la tomografía de tórax infiltrado en «vidrio esmerilado¼, parcheado y bilateral. Se realizó diagnóstico de virus de la inmunodeficiencia humana positivo y fibrobroncoscopia con lavado broncoalveolar sin desarrollo de patógenos. Se interpreta como neumonía intersticial linfoidea asociada a síndrome de linfocitosis infiltrativa difusa. Se inició terapia antirretroviral con buena evolución y desaparición de los síntomas y de los infiltrados pulmonares.

Diffuse infiltrative lymphocytosis syndrome occurs in association with HIV infection; it requires meeting the diagnostic criteria and ruling out other infectious and autoimmune pathologies. We present the case of a 47-year-old woman who consulted for bilateral parotid edema, sicca syndrome, cough and impregnation syndrome, which was observed in the chest tomography infiltrated in ground glass, patched and bilateral. A diagnosis of HIV positive and fiberoptic bronchoscopy with bronchoalveolar lavage was made without the development of pathogens. It is interpreted as lymphoid interstitial pneu monia associated with DILS. Antiretroviral therapy was started with good evolution and disappearance of symptoms and pulmonary infiltrates.

Probable segundo evento por SARS-CoV-2: 12 casos / Probable second event due to SARS-CoV-2: 12 cases

Con el avance de la pandemia por COVID-19, la aparición de pacientes con un segundo episodio confirmado por reacción en cadena de la polimerasa, con transcripción inversa (rt-PCR) compatible con reinfección, puso de manifiesto la falta de recomendaciones para su abordaje.Presentamos un estudio descriptivo multicéntrico retro-prospectivo de una serie de doce casos atendidos entre el 01/06/2020 y el 20/10/2020. En la misma, diez casos presentaron el segundo episodio en un período de tiempo menor a 90 días.Por su complejidad, la confirmación de una reinfección no está al alcance en la práctica diaria. Esto requiere de estudios que incluyan comparaciones genómicas de cepas virales involucradas en ambos episodios, determinación de la infectividad del ARN por cultivo viral y análisis molecular.Es necesario establecer definiciones operativas y algoritmos clínicos para la atención de los segundos episodios

As COVID-19 pandemic progresses, patients with a second confirmed episode by reverse transcription-polymerase chain reaction (RT PCR) compatible with reinfection reveals the lack of recommendations for its approach.A multicenter retro-prospective descriptive work was done of a series of 12 cases evaluated between June 1, 2020 and October 20, 2020. In this study, 10 out of 12 cases presented the second episode occurred in less than 90 days.Due to the diagnosing reinfection complexity, its confirmation is not available in the daily practice, this requires studies, which include viral strains genomic comparisons involved in both episodes, ARN determination infectivity by viral culture and molecular analysis.It is necessary to establish operational and clinical algorithms definitions to assist second episodes