Random/aligned electrospun PCL fibrous matrices with modified surface textures: Characterization and interactions with dermal fibroblasts and keratinocytes.

Micro- or nano-surface topography of a biomaterial can improve various cellular activities for obtaining functional tissues. Electrospun fibers can gain further functionality when introduced topographic details to their surfaces. In this regard, we produced random and aligned polycaprolactone (PCL) micron/submicron fibers by the electrospinning method. Simultaneously, the surface structure of the fibers was altered by applying phase separation processes including non-solvent-induced phase separation (NIPS) and vapor-induced phase separation (VIPS) mechanisms. As a result, PCL fibers with porous, wrinkled, grooved, and crater-like morphology were obtained. Human dermal fibroblasts (BJ cells) and human keratinocytes (HS2) were cultured onto the fiber surfaces and the data were evaluated in terms of cell-material interactions. Results showed that not only the orientation of fibers but also fiber topography affected both cell-fiber and cell-cell interactions in different manners. It was observed that the wrinkled topography is the most suitable for both dermal fibroblasts and keratinocytes in terms of cell attachment and proliferation. We also concluded that cellular behavior was varied according to the morphology of the cells used. Morphological observations showed that HS2 cells proliferated more intensively on all surfaces compared to BJ cells. All these findings can be evaluated in terms of the design of tissue scaffolds, especially in skin tissue engineering.

Clinical experience on umbilical cord mesenchymal stem cell treatment in 210 severe and critical COVID-19 cases in Turkey.

OBJECTIVE: Treatment for COVID-19 is still urgent need for the critically ill and severe cases. UC-MSC administration has a therapeutic benefit for severe COVID-19 patients even in the recovery period. In this paper, we aimed to present our clinical experience with UC-MSC treatment in severe and critical severe COVID-19 patients. METHODS: In this study we evaluated the clinical outcome of severe/critically severe 210 COVID-19 patients treated with UC-MSCs, 1-2 × 106 per kilogram to 210 patients from 15/10/2020 until 25/04/2021. RESULTS: Out of 99 critically severe intubated patients we have observed good clinical progress/discharged from ICU in 52 (52.5%) patients. Where as 86 (77.5%) of 111 severe unintubated patients discharged from ICU. Intubated 47 (47.5%) patients and unintubated 25 (22.5%) patients pass away. Significantly higher survival was observed in patients who underwent UC-MSCs before intubation (OR = 1.475, 95% CI = 1.193-1.824 p < 0.001). It was observed that the SaO2 parameter tended to improve after UC-MSC therapy compared to all groups. But SaO2 parameter between intubated and unintubated groups was not statistically significant (p > 0.05), while in discharged cases SaO2 parameter was statistically significant (p = 0.01). Besides, there was a statistically significant relation with intubation status, age (OR = 3.868, 95% CI = 0.574-7.152 p = 0.02) and weigh (OR = 6.768, 95% CI = 3.423-10.112 p < 0.001) thus presented an elevated risk for COVID-19. The linear regression analysis confirmed that the high weight was associated with the risk of intubation in COVID-19 (p = 0.001). CONCLUSIONS: According to our results and from recent studies, UC-MSC treatment is safe with high potential to be used as an added therapeutic treatment for severe COVID-19 patients. Our experience showed that UC-MSC therapy may restore oxygenation and downregulate cytokine storm in patients hospitalized with severe COVID-19. We advice wider randomised studies to discover the detailed therapeutic pathophysiology of the MSCs on COVID-19 patients. MSCs transplantation improves the damaging effects of the cytokine storm through immunomodulation and improving tissue and organ repair. Severe patients who were unintubated were in the Phase I, while critical patients who were intubated were in the Phase II. The figure is created via biorender application, ( BioRender.com ).

Fabrication, characterization, and in vivo biocompatibility evaluation of titanium-niobium implants.

In this study, biocompatible titanium-niobium (Ti-Nb) alloys were fabricated by using powder metallurgy methods. Physical, morphological, thermal, and mechanical analyses were performed and their in vivo compatibility was evaluated. Besides α, ß, and α″ martensitic phases, α+ß Widmanstätten phase due to increasing sintering temperature was seen in the microstructure of the alloys. Phase transformation temperatures of the samples decreased as Nb content increased. The ratio of Nb in the samples affected their mechanical properties. No toxic effect was observed on implanted sites. This study shows that Ti-Nb alloys can be potentially used for orthopedic applications without any toxic effects.

A rare indication of permanent pacemaker implantation in children: congenital long QT syndrome.

Congenital Long QT Syndrome (LQTS) is a dangerous arrhythmic disorder that can be diagnosed in children with bradycardia. It is characterised by a prolonged QT interval and torsades de pointes that may cause sudden death. Long QT syndrome is an ion channelopathy with complex molecular and physiological infrastructure. Unlike the acquired type, congenital LQTS has a genetic inheritance and it may be diagnosed by syncope, stress in activity, cardiac dysfunction, sudden death or sometimes incidentally. Permanent pacemaker implantation is required for LQTS with resistant bradycardia even in children to resolve symptoms and avoid sudden death.

Artificial Intelligence-Empowered Mobilization of Assessments in COVID-19-like Pandemics: A Case Study for Early Flattening of the Curve.

The global outbreak of the Coronavirus Disease 2019 (COVID-19) pandemic has uncovered the fragility of healthcare and public health preparedness and planning against epidemics/pandemics. In addition to the medical practice for treatment and immunization, it is vital to have a thorough understanding of community spread phenomena as related research reports 17.9-30.8% confirmed cases to remain asymptomatic. Therefore, an effective assessment strategy is vital to maximize tested population in a short amount of time. This article proposes an Artificial Intelligence (AI)-driven mobilization strategy for mobile assessment agents for epidemics/pandemics. To this end, a self-organizing feature map (SOFM) is trained by using data acquired from past mobile crowdsensing (MCS) campaigns to model mobility patterns of individuals in multiple districts of a city so to maximize the assessed population with minimum agents in the shortest possible time. Through simulation results for a real street map on a mobile crowdsensing simulator and considering the worst case analysis, it is shown that on the 15th day following the first confirmed case in the city under the risk of community spread, AI-enabled mobilization of assessment centers can reduce the unassessed population size down to one fourth of the unassessed population under the case when assessment agents are randomly deployed over the entire city.

Locally reconfigurable Self Organizing Feature Map for high impact malicious tasks submission in Mobile Crowdsensing.

Location-based clogging attacks in a Mobile Crowdsensing (MCS) system occur following upon the submission of fake tasks, and aim to consume the batteries and hardware resources of smart mobile devices such as sensors, memory and processors. Intelligent modeling of fake task submissions is required to enable the development of effective defense mechanisms against location-based clogging attacks with fake task submissions. An intelligent strategy for fake task submission would aim to maximize the impact on the participants of an MCS system. With this in mind, this paper introduces new algorithms exploiting the Self-Organizing Feature Map (SOFM) to identify attack locations where fake sensing tasks submitted to an MCS platform are centered around. The proposed SOFM-based model addresses issues in the previously proposed SOFM-based attack models by proposing two ways of refinement. When compared to the former models, which also use SOFM architectures, simulation results show that up to 139.9% of impact improvement can be modeled under the reconfigurable SOFM architectures.

A rare giant pericardial cyst mimicking a paracardiac mass.

Pericardial cysts are rare benign lesions of the thoracic cavity and are mostly congenital anomalies. They are induced by an incomplete coalescence of foetal lacunae during the development of the pericardium. Pericardial cysts are usually unilocular, well marginated spherical or teardrop shaped and may be attached to the pericardium directly or by a pedicle. Of all pericardial cysts, 70 to 75% are located at the right cardiophrenic angle. We report a case that was incidentally diagnosed with only chest magnetic resonance imaging because of a paracardiac mass. In order to prevent complications, the giant pericardial cyst was excised outside of the pericardium with median sternotomy.

Endovenous laser ablation under general anesthesia for day surgery: feasibility and outcomes of the 300 patients.

PURPOSE: Endovenous laser ablation (EVLA) for superficial venous insufficiency is traditionally performed under tumescent local anesthesia as day case surgery. The aim of this study is to evaluate the feasibility of general anesthesia in addition to tumescent anesthesia in patients undergoing EVLA. METHODS: The anesthesia and clinical registration records of 341 extremities of 300 adult patients were reviewed and analyzed retrospectively. Demographic and clinical data, preoperative anesthetic evaluation data (ASA physical status, preoperative airway assessment, Mallampati score), type of supraglottic device, duration of anesthesia and surgery, any surgical and/or anesthetic complication, timing of mobilization and discharge, and postoperative course were evaluated. RESULTS: Mean duration of operation and anesthesia was 28 (12-55) and 40 (20-65) minutes, respectively. Mobilization and discharge timing was 25 (11-45) and 139 (110-200) minutes, respectively. All patients were discharged the same day of surgery. CONCLUSION: The combination technique of administering general anesthesia with supraglottic device and tumescent anesthesia is a safe and effective method to reduce the patients' pain and discomfort during the EVLT procedure within the scope of day case surgery.

Honey-based PET or PET/chitosan fibrous wound dressings: effect of honey on electrospinning process.

In this study, fibrous mats were fabricated via electrospinning from solutions of polyethylene terephthalate (PET), PET/chitosan, and PET/honey at different concentrations. The effect of honey and chitosan on electrospinning process was investigated and compared. Fibers containing chitosan had a beaded or ribbon-like/branched morphology, but this morphology improved in the presence of honey. The diameter of electrospun fibers decreased with an increased ratio of honey in PET solution. In addition, fiber deposition area in the collector increased by increasing the honey content. PET/chitosan and PET/honey fibrous mats reached an equilibrium water content in 15 min and their water uptake capacities, which are important for exudating wounds, were found in the range of 280-430% on dry basis. Cytotoxicity evaluation demonstrated that fibers exhibited no cytotoxic activity. This study discloses that PET fibrous mats especially electrospun in the presence of honey could be proposed as potential wound dressing materials owing to their improved processing abilities besides their suitable structural properties.

Cardiac angiosarcoma: A case with bilateral pleural and pericardial effusion.

Cardiac sarcomas are rare malignant tumors. Angiosarcoma is the most common cardiac sarcoma and is present in up to 33% of cases. Angiosarcomas have a poor prognosis, with a short survival expectancy. We report a case of a right atrial angiosarcoma treated by partial tumor resection followed by chemotherapy.

Extremely low birth weight infants with patent ductus arteriosus: searching for the least invasiveness.

Patent ductus arteriosus (PDA) is an important problem in premature infants. Extremely low birth weight infants (ELBWI) are so fragile with respect to surgical stress that minimally invasive procedures are required. We report 26 ELBWI cases with PDA who underwent surgical closure. All had failed indomethacin treatment, or it had been contraindicated. The mean gestational age at birth was 27 weeks (range, 24-38 weeks), and the mean birth weight was 960.96 g (range, 710-1440 g). The mean age at operation was 18.06 days (range, 7-34 days), and the mean body weight at operation was 989.42 g (range, 680-1460 g). There was no surgery-related mortality or morbidity. Our surgical procedures consisted of posterior muscle-sparing thoracotomy, clipping the PDA and no ligation, and closing the thorax without a tube thoracostomy. Muscle-sparing thoracotomy reduces the likelihood of long-term physical impairment and deformity, the clipping technique minimizes the dissection of surrounding PDA tissue, and the thorax is closed without a tube. Nursing care is simplified, costs are reduced, and the number of chest x-rays needed postoperatively is reduced. We believe that surgical closure of PDA without chest tube drainage can be accomplished safely in premature infants.

Spontaneous coronary artery dissections: three case reports and review of literature.

Primary spontaneous coronary artery dissection is one of the rare causes of acute myocardial infarction and is mostly fatal. Previous studies report that it is mostly seen in middle-aged women in the last trimester of pregnancy and early postpartum period. Clinical presentation of the disease is variable in pattern, and its severity is related to extent and development rate of dissection. Herein we present three cases of primary spontaneous left main coronary artery dissection. Two of the patients are men and the third patient is a non-pregnant 69-year-old woman. The cases were presented and discussed with review of the pertinent literature.

Chitosan and polycaprolactone membranes patterned via electrospinning: effect of underlying chemistry and pattern characteristics on epithelial/fibroblastic cell behavior.

Electrospinning was used as an effective route to pattern chitosan (CS) and polycaprolactone (PCL) membranes with submicron fibers having different chemical structure (PCL or PCL/collagen) and physical characteristics (size: between ≈200 and 550 nm; randomly oriented or aligned form). While the PCL fibers with diameters in the same range (≈200 nm) were patterned on both of CS and PCL membranes to evaluate the influence of the underlying membrane chemistry, only CS membranes were patterned with PCL fibers having different sizes simply by changing the electrospinning conditions to investigate the effects of pattern characteristics. Furthermore, collagen was added to the PCL fiber structure to change the chemical composition of the fibers in a cell-attractive way. Two cell lines with different morphologies, fibroblastic MC3T3-E1 preosteoblasts and epithelial Madine Darby Bovine Kidney (MDBK) cells, were cultured on the patterned membranes. The observation of cellular behavior in terms of cell morphology and F-actin synthesis was realized by scanning electron microscopy and confocal microscopy analysis during the first 12 h of culture period. The viability of cells was controlled by MTT assay through 96 h of cell culture. The cell culture studies indicated that the leading aspect for the morphology change on patterned membranes was the fiber orientation. The aligned topography controlled the morphology of cells both on CS and PCL membranes. In the presence of collagen in the fiber structure, F-actin filament synthesis increased for MC3T3-E1 and MDBK cell lines.