Optimizing Platelet and Leucocyte-Rich Plasma as Biomaterials for Ophthalmic Applications: Impact of Centrifugation Speed.

Purpose: To assess the impact of varying centrifugation speeds on platelet and leucocyte-rich plasma (L-PRP) in liquid and gel form cellularity and growth factor concentrations for potential use against ocular surface disorders. Patients and Methods: L-PRP was collected from 16 healthy subjects using three different centrifugation speeds: 580, 1000, and 2000 g, each for 8 min at 25°C. Platelet and leukocyte counts were automatically evaluated. The concentrations of vascular endothelial growth factor (VEGF), platelet-derived growth factor (PDGF), and transforming growth factor beta 1 (TGF-B1) were measured using enzyme-linked immunosorbent assays. L-PRP gel cellularity was assessed through hematoxylin-eosin and Masson's trichrome staining, categorized as moderate or abundant, and statistically analyzed. L-PRP gel membrane's chemical composition was analyzed using Fourier-transform infrared spectroscopy (FTIR), crystallization was investigated with X-ray diffraction (XRD), and ultrastructure was assessed using surface electron microscopy (SEM). Additionally, membrane degradation was evaluated over a 7-day period. Results: No significant differences in cellularity and growth factor concentrations among centrifugation speeds (p > 0.05) were found. Moderate cellularity predominated at 580 g and 2000 g, while abundant cellularity was observed at 1000 g. No significant differences were found techniques (p = 0.16). Masson's trichrome staining suggested the existence of abundant fibrin at 1000 g but without significant differences (p = 0.07). FTIR analysis exhibited the characteristic fibrin bands at all speeds, and XRD indicated a keratin-like pattern. SEM revealed greater porosity at 580 g and fibrin membrane degradation was lower at this speed (p = 0.0001). Conclusion: Centrifugation speed did not significantly affect growth factor concentration or cellularity in both liquid and gel L-PRP. Further studies should explore the impact of different separation techniques for L-PRP used in ophthalmic applications.

Prevalence and clinical characteristics of neurotrophic keratopathy in hispanic population in northeastern Mexico.

PURPOSE: To evaluate the prevalence and clinical characteristics of neurotrophic keratopathy (NK) in northeastern Mexico. METHODS: Retrospective cross-sectional study in which NK patients admitted to our ophthalmology clinic between 2015 and 2021 were consecutively enrolled. Data regarding demographics, clinical characteristics, and comorbidities were collected at the time diagnosis of NK was made. RESULTS: In the period from 2015 to 2021, a total of 74,056 patients were treated and of these 42 had a diagnosis of neurotrophic keratitis. The prevalence found was 5.67 [CI95 3.95-7.38] in 10,000 cases. The mean age observed was 59 ± 17.21 years occurring more frequently in males in 59% and with corneal epithelial defects in 66.7%. The most frequent antecedents were the use of topical medications in 90%, the presence of diabetes mellitus 2 in 40.5% and systemic arterial hypertension in 26.2%. A higher proportion of male patients with corneal alterations and a higher proportion of female patients with corneal ulcerations and/or perforation were observed. CONCLUSION: Neurotrophic keratitis is an underdiagnosed disease with a broad clinical spectrum. The antecedents that were contracted corroborate what was reported in the literature as risk factors. The prevalence of the disease in this geographical area was not reported, so it is expected to increase over time when searching for it intentionally.

Microbiology of genus Raoultella, clinical features and difficulties in its diagnosis / Microbiología del género Raoultella, características clínicas y dificultades para su diagnóstico

The genus Raoultella, which belongs to the Enterobacteriaceae family, encompasses gramnegative, oxidase-negative, aerobic, encapsulated and motionless bacilli. Currently, four species of this genus have been described: Raoultella terrigena (R. terrigena), Raoultella planticola (R. planticola), Raoultella ornithinolytica (R. ornithinolytica) and Raoultella electrica (R. electrica), out of which R. planticola and R. ornithinolytica are the most important because of their probable association as pathogenic agents. The incidence of this genus has been underestimated, given that detecting it is really difficult, since it is misidentified as Klebsiella spp. by using manual and automated conventional phenotypic methods. The rapid and correct detection has been increasing since the advent of mass spectrometers (MALDI-TOF MS), which have been used for the differentiation of Klebsiella spp. and Raoultella spp. Currently 80 cases of bacteremia secondary to Raoultella spp. have been identified with different sites of primary infection, which is why it is important to emphasize proper detection in hospitals and healthcare facilities.

El género Raoultella, perteneciente a la familia Enterobacteriaceae, engloba bacilos gram negativos, oxidasa negativos, aeróbicos, encapsulados e inmóviles. Actualmente se han descrito cuatro especies de este género: Raoultella terrigena (R. terrigena), Raoultella planticola (R. planticola), Raoultella ornithinolytica (R. ornithinolytica) y Raoultella electrica (R. electrica), entre las que la R. planticola y la R. ornithinolytica son las más importantes por su probable asociación como agentes patógenos. Se ha subestimado la incidencia del género por la dificultad que presenta su caracterización al ser mal identificado como Klebsiella spp., al usar métodos fenotípicos manuales y automatizados convencionales. La rápida y correcta detección de Raoultella spp. ha ido aumentando desde la llegada de espectrómetros de masas (MALDI-TOF MS), útiles en la diferenciación entre Klebsiella spp. y Raoultella spp. Se han identificado 80 casos de bacteremia por Raoultella spp., con infección primaria en diversos sitios, por lo que es importante hacer énfasis en su correcta detección en los hospitales y centros de atención médica.