Preparation and characterization of propolis reinforced eggshell membrane/ GelMA composite hydrogel for biomedical applications.

Gelatin methacrylate-based hydrogels (GelMA) were widely used in tissue engineering and regenerative medicine. However, to manipulate their various chemical and physical properties and create high-efficiency hydrogels, different materials have been used in their structure. Eggshell membrane (ESM) and propolis are two nature-derived materials that could be used to improve the various characteristics of hydrogels, especially structural and biological properties. Hence, the main purpose of this study is the development of a new type of GelMA hydrogel containing ESM and propolis, for use in regenerative medicine. In this regard, in this study, after synthesizing GelMA, the fragmented ESM fibers were added to it and the GM/EMF hydrogel was made using a photoinitiator and visible light irradiation. Finally, GM/EMF/P hydrogels were prepared by incubating GM/EMF hydrogels in the propolis solution for 24 h. After various structural, chemical, and biological characterizations, it was found that the hydrogels obtained in this study offer improved morphological, hydrophilic, thermal, mechanical, and biological properties. The developed GM/EMF/P hydrogel presented more porosity with smaller and interconnected pores compared to the other hydrogels. GM/EMF hydrogels due to possessing EMF showed compressive strength up to 25.95 ± 1.69 KPa, which is more than the compressive strength provided by GM hydrogels (24.550 ± 4.3 KPa). Also, GM/EMF/P hydrogel offered the best compressive strength (44.65 ± 3.48) due to the presence of both EMF and propolis. GM scaffold with a contact angle of about 65.41 ± 2.199 θ showed more hydrophobicity compared to GM/EMF (28.67 ± 1.58 θ), and GM/EMF/P (26.24 ± 0.73 θ) hydrogels. Also, the higher swelling percentage of GM/EMF/P hydrogels (343.197 ± 42.79) indicated the high capacity of this hydrogel to retain more water than other scaffolds. Regarding the biocompatibility of the fabricated structures, MTT assay results showed that GM/EMF/P hydrogel significantly (p-value < 0.05) supported cell viability. Based on the results, it seems that GM/EMF/P hydrogel could be a promising biomaterial candidate for use in various fields of regenerative medicine.

Cost-benefit analysis of Intensive Care Unit with Activity-Based Costing approach in the era COVID-19 pandemic: A case study from Iran.

BACKGROUND: Providing intensive care to acute patients is a vital part of health systems. However, the high cost of Intensive Care Units (ICU) has limited their development, especially in low-income countries. Due to the increasing need for intensive care and limited resources, ICU cost management is important. This study aimed to analyze the cost-benefit of ICU during COVID-19 in Tehran, Iran. METHODS: This cross-sectional study is an economic evaluation of health interventions. The study was conducted in the COVID-19 dedicated ICU, from the provider's point of view and within one-year horizon. Costs were calculated using a top-down approach and the Activity-Based Costing technique. Benefits were extracted from the hospital's HIS system. Benefit Cost ratio (BCR) and Net Present Value (NPV) indexes were used for cost-benefit analysis (CBA). A sensitivity analysis was performed to evaluate the dependence of the CBA results on the uncertainties in the cost data. Analysis was performed with Excel and STATA software. RESULTS: The studied ICU had 43 personnel, 14 active beds, a 77% bed occupancy rate, and 3959 occupied bed days. The total costs were $2,372,125.46 USD, of which 70.3% were direct costs. The highest direct cost was related to human resources. The total net income was $1,213,314.13 USD. NPV and BCR were obtained as $-1,158,811.32 USD and 0.511 respectively. CONCLUSION: Despite operating with a relatively high capacity, ICU has had high losses during the COVID-19. Proper management and re-planning in the structure of human resources is recommended due to its importance in the hospital economy, provision of resources based on needs assessment, improvement of drugs management, reduction of insurance deductions in order to reduce costs and improve ICU productivity.

The Open, Randomized, Positive Control Clinical Trial of Guluronic Acid (G2013) on SARS-CoV-2 Patients.

INTRODUCTION: Recently, the coronavirus disease 2019 (COVID-19) infection, with a vast spectrum of clinical and paraclinical symptoms has been a major health concern worldwide. Therapeutical management of COVID-19 includes antiviral and anti-inflammatory drugs. NSAIDs, as the second-line therapy, are often prescribed to relieve the symptoms of COVID-19. The α-L-guluronic acid (G2013) is a non-steroidal patented (PCT/EP2017/067920) agent with immunomodulatory properties. This study investigated the effect of G2013 on the outcome of COVID-19 in moderate to severe patients. METHODS: The disease's symptoms were followed up during hospitalization and for 4 weeks postdischarge in G2013 and control groups. Paraclinical indices were tested at the time of admission and discharge. Statistical analysis was performed on clinical and paraclinical parameters and ICU admission and death rate. RESULTS: The primary and secondary outcomes indicated the efficiency of G2013 on COVID-19 patients' management. There were significant differences in the duration of improvement of fever, coughing, fatigue/malaise. Also, a comparison of paraclinical indices at the time of admission and discharge showed significant change in prothrombin, D-dimer, and platelet. As the main findings of this study, G2013 significantly decreased the percentage of ICU admission (control:17 patients, G2013:1 patient) and death (control: 7 cases, G2013:0). CONCLUSION: These results conclude that G2013 has sufficient potential to be considered for moderate to severe COVID-19 patients, can significantly reduce the clinical and physical complications of this disease, has a positive effect on modulating the coagulopathy process, and aids in saving lives.

Recent advances in nano-scaffolds for tissue engineering applications: Toward natural therapeutics.

Among the promising methods for repairing or replacing tissue defects in the human body and the hottest research topics in medical science today are regenerative medicine and tissue engineering. On the other hand, nanotechnology has been expanded into different areas of regenerative medicine and tissue engineering due to its essential benefits in improving performance in various fields. Nanotechnology, a helpful strategy in tissue engineering, offers new solutions to unsolved problems. Especially considering the excellent physicochemical properties of nanoscale structures, their application in regenerative medicine has been gradually developed, and a lot of research has been conducted in this field. In this regard, various nanoscale structures, including nanofibers, nanosheets, nanofilms, nano-clays, hollow spheres, and different nanoparticles, have been developed to advance nanotechnology strategies with tissue repair goals. Here, we comprehensively review the application of the mentioned nanostructures in constructing nanocomposite scaffolds for regenerative medicine and tissue engineering. This article is categorized under: Nanotechnology Approaches to Biology > Nanoscale Systems in Biology Implantable Materials and Surgical Technologies > Nanotechnology in Tissue Repair and Replacement Diagnostic Tools > Biosensing.

Blue Rubber Bleb Nevus Syndrome because of 12 Years of Iron Deficiency Anemia in a Patient by Double Balloon Enteroscopy; A Case Report and Review of Literature.

Blue rubber bleb nevus syndrome (BRBNS) is a rare disorder comprised of venous malformation mostly involving the skin and gastrointestinal (GI) tract but can also involve other visceral organs. The most predominant site of GI tract involvement is the small bowel. In patients with GI lesions, treatment depends on the severity of bleeding, and extent of involvement. Conservative therapy with iron supplementation and blood transfusion is appropriate in cases with mild bleeding but in severe cases endoscopic and surgical interventions would be beneficial. Also, medical therapy with sirolimus significantly reduces bleeding. A 20-year-old woman was referred to our hospital after transfusion of six units of packed cell because of several episodes of lower GI bleeding within the past three months in the form of melena and a single episode of hematochezia. Her last hemoglobin level before admission was 10mg/dl. She underwent various unsuccessful investigations since she was eight years old to find the origin of refractory iron deficiency anemia. In upper endoscopy, five bleeding polypoid lesions were discovered in the jejunum. Lesions were excised by snare polypectomy. Over a six-month follow-up period, no signs of lower GI bleeding were noted and the patient had a normal hemoglobin level.

Acute transverse myelitis after SARS-CoV-2 infection: a rare complicated case of rapid onset paraplegia.

A 63-year-old Caucasian male, known case of controlled type 2 diabetes, chronic renal failure, and ischemic heart disease, was presented with weakness and loss of movement in lower limbs, an absent sensation from the chest below, constipation, and urinary retention. About 4 days before these symptoms, he experienced a flu-like syndrome. Suspicious for COVID-19, his nasopharyngeal specimen's reverse transcription-polymerase chain reaction (RT-PCR) resulted positive. Chest X-ray and HRCT demonstrated severe pulmonary involvement. Immediately, he was admitted to the emergency ward, and the treatment was started according to the national COVID-19 treatment protocol. Subsequently, diagnostic measures were taken to investigate the patient's non-heterogeneous peripheral (spinal) neuromuscular manifestations. Brain CT scan and MRI were normal, but spinal MRI with gadolinium contrast showed extensive increased T2 signal involving central gray matter and dorsal columns, extended from C7 to T12 with linear enhancement in the sagittal plane, posteriorly within the mid and lower thoracic cord. The CSF specimen demonstrated pleocytosis, positive RT-PCR for SARS-CoV-2, and elevated IgG index. Clinical presentation, MRI, CSF, and laboratory findings prioritized the acute transverse myelitis (ATM) as a probable complication of COVID-19 infection over other differential diagnoses. Intravenous methylprednisolone and, subsequently, IV human immunoglobulin were added to the treatment regimen. In the end, the complete resolution of dysesthesia, urinary retention, and constipation were achieved. After continuous and extended respiratory and motor rehabilitation programs, he was discharged asymptomatic.

Sniffer dogs as a screening/diagnostic tool for COVID-19: a proof of concept study.

BACKGROUND: Sniffer dogs are able to detect certain chemical particles and are suggest to be capable of helping diagnose some medical conditions and complications, such as colorectal cancer, melanoma, bladder cancer, and even critical states such as hypoglycemia in diabetic patients. With the global spread of COVID-19 throughout the world and the need to have a real-time screening of the population, especially in crowded places, this study aimed to investigate the applicability of sniffer dogs to carry out such a task. METHODS: Firstly, three male and female dogs from German shepherd (Saray), German black (Kuzhi) and Labrador (Marco) breeds had been intensively trained throughout the classical conditioning method for 7 weeks. They were introduced to human specimens obtained from the throat and pharyngeal secretions of participants who were already reported positive or negative for SARS-COV-2 infection be RT-PCR. Each dog underwent the conditioning process for almost 1000 times. In the meantime another similar condition process was conducted on clothes and masks of COVID-19 patient using another three male and female dogs from Labrador (Lexi), Border gypsy (Sami), and Golden retriever (Zhico) breeds. In verification test for the first three dogs, 80 pharyngeal secretion samples consisting of 26 positive and 54 negative samples from different medical centers who underwent RT-PCR test were in a single-blind method. In the second verification test for the other three dogs, masks and clothes of 50 RT-PCR positive and 70 RT-PCR negative cases from different medical center were used. RESULTS: In verification test using pharyngeal secretion, the sniffer dogs' detection capability was associated with a 65% of sensitivity and 89% of specificity and they amanged to identify 17 out of the 26 positive and 48 out of the 54 true negative samples. In the next verification test using patients' face masks and clothes, 43 out of the 50 positive samples were correctly identified by the dogs. Moreover, out of the 70 negative samples, 65 samples were correctly found to be negative. The sensitivity of this test was as high as 86% and its specificity was 92.9%. In addition, the positive and negative predictive values were 89.6 and 90.3%, respectively. CONCLUSION: Dogs are capable of being trained to identify COVID-19 cases by sniffing their odour, so they can be used as a reliable tool in limited screening.

The role of artificial intelligence in colon polyps detection.

Over the past few decades, artificial intelligence (AI) has evolved dramatically and is believed to have a significant impact on all aspects of technology and daily life. The use of AI in the healthcare system has been rapidly growing, owing to the large amount of data. Various methods of AI including machine learning, deep learning and convolutional neural network (CNN) have been used in diagnostic imaging, which have helped physicians in the accurate diagnosis of diseases and determination of appropriate treatment for them. Using and collecting a huge number of digital images and medical records has led to the creation of big data over a time period. Currently, considerations regarding the diagnosis of various presentations in all endoscopic procedures and imaging findings are solely handled by endoscopists. Moreover, AI has shown to be highly effective in the field of gastroenterology in terms of diagnosis, prognosis, and image processing. Herein, this review aimed to discuss different aspects of AI use for early detection and treatment of gastroenterology diseases.

Role of inducible nitric oxide synthase in myocardial ischemia-reperfusion injury in sleep-deprived rats.

INTRODUCTION: REM sleep deprivation (SD) decreases tolerance of the rat heart to ischemia-reperfusion (IR) injury; the underlying mechanisms, however, are unknown. This study aimed at determining whether changes in iNOS, Bax, and Bcl-2 gene expression are involved in this detrimental effect. METHOD: SD was induced by flowerpot technique for a period of 4 days. This method is simple and able to induce sleep fragmentation which occurs as one of the sleep disorder symptoms in clinical conditions. The hearts of control and SD rats were perfused in Langendorff apparatus and subjected to 30 min ischemia, followed by 90 min reperfusion. The hemodynamic parameters (left ventricular developed pressure (LVDP), and ± dp/dt), NOx (nitrite + nitrate) level, infarct size, and mRNA expression of iNOS, Bax, and Bcl-2 were measured after IR. RESULTS: SD rats had lower recovery of post-ischemic LVDP (32.8 ± 2.5 vs. 51.5 ± 2.1 mmHg; P < 0.05), + dp/dt (1555 ± 66 vs. 1119.5 ± 87 mmHg/s; P < 0.05) and - dp/dt (1437 ± 65 vs. 888 ± 162 mmHg/s; P < 0.05). SD rats also had higher NOx levels (41.4 ± 3.1 vs. 22.4 ± 3.6 µmol/L; P < 0.05) and infarct size (64.3 ± 2.3 vs. 38.3 ± 1.6%; P < 0.05) after IR, which along with LVDP, ± dp/dt restored to near normal status in the presence of aminoguanidine, a selective iNOS inhibitor. Following IR, expression of iNOS and Bax increased and Bcl-2 decreased (502, 372, and 54%, respectively) in SD rats; whereas in the presence of aminoguanidine, expression of iNOS and Bax significantly decreased and Bcl-2 increased (165, 168, and 19%, respectively). CONCLUSION: Higher expression of iNOS and subsequent increase in apoptosis in the hearts after IR may contribute to less tolerance to myocardial IR injury in SD rats.

Effects of Vitamin D and Calcium Supplementation on Micro-architectural and Densitometric Changes of Rat Femur in a Microgravity Simulator Model.

BACKGROUND: Revealing data on the role of vitamin D and calcium supplementation in bone health has led some to suggest that vitamin D and calcium treatment could also play a role in protecting bone against microgravity-induced mineral loss. OBJECTIVES: The aim of the present study was to investigate the effects of vitamin D and calcium administration on microscopic and densitometric changes of rat femur in a Microgravity Simulator Model. MATERIALS AND METHODS: After designing a Microgravity Simulator Model, 14 rats were placed in the cages as follows: seven rats as osteoporosis group and seven rats received oral supplement of calcium/vitamin D as the treatment group. Animals were sacrificed after eight weeks and then both femurs were removed. Bone mineral density was measured for one femur from each animal, and morphologic studies were evaluated for the contralateral femur. RESULTS: Bone mineral density of the whole femur in the treatment group was significantly higher than the osteoporosis group (0.168 ± 0.005 vs. 0.153 ± 0.006, P = 0.003). Also, bone mineral content of the whole femur was significantly higher in treatment group (0.415 ± 0.016 vs. 0.372 ± 0.019, P = 0.003). However, resorption eroded surface percentage was higher in the osteoporosis group (18.86 ± 3.71% vs. 9.71 ± 1.61%, P = 0.002). CONCLUSIONS: According to the results of this study, vitamin D and calcium administration might have protective effects against microgravity-induced mineral loss in a Rat Microgravity Simulator Model.