RESUMEN
Gamete formation and subsequent offspring development often involve extended phases of suspended cellular development or even dormancy. How cells adapt to recover and resume growth remains poorly understood. Here, we visualized budding yeast cells undergoing meiosis by cryo-electron tomography (cryoET) and discovered elaborate filamentous assemblies decorating the nucleus, cytoplasm, and mitochondria. To determine filament composition, we developed a "filament identification" (FilamentID) workflow that combines multiscale cryoET/cryo-electron microscopy (cryoEM) analyses of partially lysed cells or organelles. FilamentID identified the mitochondrial filaments as being composed of the conserved aldehyde dehydrogenase Ald4ALDH2 and the nucleoplasmic/cytoplasmic filaments as consisting of acetyl-coenzyme A (CoA) synthetase Acs1ACSS2. Structural characterization further revealed the mechanism underlying polymerization and enabled us to genetically perturb filament formation. Acs1 polymerization facilitates the recovery of chronologically aged spores and, more generally, the cell cycle re-entry of starved cells. FilamentID is broadly applicable to characterize filaments of unknown identity in diverse cellular contexts.
Asunto(s)
Gametogénesis , Mitocondrias , Proteínas de Saccharomyces cerevisiae , Saccharomyces cerevisiae , Aldehído Deshidrogenasa/metabolismo , Aldehído Deshidrogenasa/química , Núcleo Celular/metabolismo , Núcleo Celular/ultraestructura , Coenzima A Ligasas/metabolismo , Microscopía por Crioelectrón , Citoplasma/metabolismo , Tomografía con Microscopio Electrónico , Meiosis , Mitocondrias/metabolismo , Mitocondrias/ultraestructura , Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/ultraestructura , Proteínas de Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/química , Esporas Fúngicas/metabolismo , Modelos Moleculares , Estructura Cuaternaria de ProteínaRESUMEN
Background: Ischeamia reperfusion injury is a frequent challenge during tissue reconstruction. Atorvastatin and Sildenafil, have been studied for their protective and/or therapeutic effects on various organ systems subjected to IRI. The aim of the present study was to compare a single dose of Atorvastatin and Sildenafil pretreatment on acute oxidative/nitrosative stress and the subsequent dermal flap necrosis. Materials and Methods: Forty-five Sprague-Dawley rats, were randomly allocated into three equal groups(n=15): Group A: Control rats treated with intraperitoneal saline, Group B: Sildenafil group, and Group C: atorvastatin group. All rats underwent flap elevation and inferior epigastric artery occlusion thirty minutes after drug administration. Myeloperoxidase activity, malondialdehyde levels and inducible nitric oxide synthase activity were evaluated 12 hours after reperfusion. Flap survivability was analysed 7 days after the procedure. Results: Statistically significant reduction was detected in sildenafil and atorvastation. Measurements of myelopyroxidase followed a similar pattern, interestingly malonadehyde levels measured to be significantly lower in the sildenafil group. Contrary, iNOS activity atorvastatin was significantly elevated in atorvastatin group. Conclusion: The single dose of atorvastatin or sildenafil increase flap survivability almost equally, however only atorvastatin enhances significantly iNOS expression.
Asunto(s)
Atorvastatina/farmacología , Óxido Nítrico , Daño por Reperfusión/tratamiento farmacológico , Citrato de Sildenafil/farmacología , Piel/irrigación sanguínea , Vasodilatadores/farmacología , Animales , Atorvastatina/uso terapéutico , Modelos Animales de Enfermedad , Supervivencia de Injerto/efectos de los fármacos , Necrosis/etiología , Necrosis/prevención & control , Óxido Nítrico/biosíntesis , Estrés Oxidativo/efectos de los fármacos , Distribución Aleatoria , Ratas , Ratas Sprague-Dawley , Daño por Reperfusión/metabolismo , Citrato de Sildenafil/uso terapéutico , Piel/efectos de los fármacos , Piel/patología , Colgajos Quirúrgicos/irrigación sanguínea , Colgajos Quirúrgicos/patología , Resultado del Tratamiento , Vasodilatadores/uso terapéuticoRESUMEN
A fit man in his 60s presented with an infected Achilles tendon (AT) following two failed repairs for a traumatic rupture. Initial debridement of necrotic tissue resulted in a large soft tissue defect requiring robust coverage. Following aggressive wound management, an anterolateral thigh flap was elevated with tensor fasciae latae (TFL) which was triple-rolled to provide soft tissue coverage and tendon reconstruction.The flap remained healthy and was monitored with a flow coupler device. Initially, the foot was placed in plantarflexion before gradually increasing the angle to neutral and a thermoplastic splint was used to offload pressure on the flap. Following 1 month of non-weight-bearing, gentle mobilisation began. Three months postoperatively, the patient could walk, had resumed indoor cycling and demonstrated a comparable heel raise with the contralateral side. MRI showed a taut TFL attached to the distal AT and ultrasound showed a smoothly gliding TFL.
Asunto(s)
Tendón Calcáneo , Traumatismos de los Tejidos Blandos , Masculino , Humanos , Muslo , Traumatismos de los Tejidos Blandos/cirugía , Resultado del Tratamiento , Colgajos Quirúrgicos , Tendón Calcáneo/cirugía , Tendón Calcáneo/lesionesRESUMEN
The deep inferior epigastric perforator (DIEP) flap is the gold standard for autologous breast reconstruction. One or two pedicles may be used. Our study is the first to compare unipedicled and bipedicled DIEP flaps on donor and recipient site outcomes in the same patient cohort. Methods: This is a retrospective cohort study comparing DIEP flap outcomes between 2019 and 2022. Results: There were 98 patients, categorized differently for recipient or donor site. The recipient groups were unilateral unipedicled (N = 52), bilateral unipedicled (N = 15), and unilateral bipedicled (N = 31), and donor site groups were unipedicled (N = 52) and bipedicled (N = 46, including bilateral unipedicled and unilateral bipedicled). Bipedicled DIEP flaps had 1.15 times greater odds of donor site complication (95% CI, 0.52-2.55). Adjusting for operative time that was longer in bipedicled DIEP flaps (P < 0.001), odds ratio decreased, and there was a lower probability of donor site complication for bipedicled flaps (OR, 0.84; 95% CI, 0.31-2.29). Odds of recipient area complication was not significantly different between groups. Unilateral unipedicled DIEP flaps had significantly higher rates of revisional elective surgery than unilateral bipedicled DIEP flaps (40.4% versus 12.9%; P = 0.029). Conclusions: We demonstrate no significant difference in donor site morbidity between unipedicled and bipedicled DIEP flaps. Bipedicled DIEP flaps do have slightly higher rates of donor site morbidity, which can be partly explained by longer operative times. There is no significant difference in recipient site complications, and bipedicled DIEP flaps can reduce rates of further elective surgery.
RESUMEN
BACKGROUND: Currently, one published study documented operative time (OT) as a predictor for postoperative outcomes in bilateral deep inferior epigastric perforator (DIEP) flap breast reconstructions. No literature has investigated this in unilateral DIEP flaps. We aimed to determine the relationship between unilateral OT, postoperative complications, unplanned reoperations (UR), and extended length-of-stay (eLOS). METHODS: Patients who underwent elective unilateral DIEP reconstruction from 2018 to 2023 at a tertiary centre in London, United Kingdom, were retrospectively analysed. Patients were divided into four groups depending on OT quartiles to define a critical cut-off period. Data on extensive covariates, including procedural complexity, was recorded and used in univariable and multivariable regression models. RESULTS: The final cohort contained 173 patients. After risk-adjustment, ≥421-minute operations led to a significantly higher overall complication rate (HR: 2.14, 95% CI: 1.26, 3.64, p = 0.005) relative to <421 min. Significantly higher odds of eLOS were observed in the ≥460-minute group (OR: 2.07, 95% CI: 1.07, 3.99, p = 0.03) compared to <460 min. There was no significant effect on the rate of postoperative UR across any OT group. CONCLUSIONS: We confirmed OT was an independent predictor for postoperative outcomes in the DIEP flap, and demonstrated this in unilateral reconstructions. A clinical maximum threshold of 7 h was derived based on this cohort to help guide future surgical practice. Efficiency can be achieved by meticulous preoperative planning and process standardisation, multiple senior surgeons working per flap, and smooth teamwork between specialities and intraoperative staff.