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1.
Future Microbiol ; 19: 9-19, 2024 01.
Article in English | MEDLINE | ID: mdl-38294272

ABSTRACT

Aim: Mucormycosis has been associated with SARS-CoV-2 infections during the last year. The aim of this study was to triple-hit viral and fungal RNA-dependent RNA polymerases (RdRps) and human inosine monophosphate dehydrogenase (IMPDH). Materials & methods: Molecular docking and molecular dynamics simulation were used to test nucleotide inhibitors (NIs) against the RdRps of SARS-CoV-2 and Rhizopus oryzae RdRp. These same inhibitors targeted IMPDH. Results: Four NIs revealed a comparable binding affinity to the two drugs, remdesivir and sofosbuvir. Binding energies were calculated using the most abundant conformations of the RdRps after 100-ns molecular dynamics simulation. Conclusion: We suggest the triple-inhibition potential of four NIs against pathogenic RdRps and IMPDH, which is worth experimental validation.


Subject(s)
COVID-19 , SARS-CoV-2 , Humans , RNA-Dependent RNA Polymerase/genetics , RNA-Dependent RNA Polymerase/chemistry , Antiviral Agents/therapeutic use , Rhizopus oryzae , Molecular Docking Simulation , Nucleotides , RNA, Viral
2.
BMC Neurol ; 23(1): 271, 2023 Jul 17.
Article in English | MEDLINE | ID: mdl-37460962

ABSTRACT

BACKGROUND: Several studies have addressed gender differences in stroke. Yet, results are diverse, and research is still required in different populations. So, this study investigates variation in stroke according to gender in a developing country. METHODS: This is a registry-based, retrospective observational cross-sectional study comparing men and women as regards age, risk factors, stroke severity, quality of services, and stroke outcome. RESULTS: Data analyzed comprised 4620 patients. It was found that men outnumbered women, while women had an older age, more prevalence of hypertension and atrial fibrillation, with severer strokes and worse outcomes. However, there was no gender difference in promptness nor frequency of administration of revascularization therapies. CONCLUSION: Despite the gender difference in risk factors and stroke severity, we could not detect any significant disparity in acute stroke services provided to either gender. Among age categories in women, we identified differences in acute ischemic stroke subtypes, and acute management in favor of older age.


Subject(s)
Ischemic Stroke , Stroke , Male , Humans , Female , Retrospective Studies , Cross-Sectional Studies , Developing Countries , Ischemic Stroke/complications , Stroke/epidemiology , Stroke/therapy , Stroke/etiology , Risk Factors , Sex Factors
3.
Sci Rep ; 13(1): 11461, 2023 07 15.
Article in English | MEDLINE | ID: mdl-37454158

ABSTRACT

Paper coating plays an important role in the paper properties, printability and application. The nanocoating is a multifunction layer that provides the paper with unique features. In this work, nanocoating formulas were prepared using a green method and component. The nanocoating formulas were based on biopolymers nanostarch NSt and nanochitosan NCh (NCS) decorated with Egyptian kaolinite Ka doped with zinc nanoparticles NCS@xka/ZnONPs (x represents different ratios) support for multifunctional uses. The nanocoating formulas were characterized using a physiochemical analysis as well as a topographical study. FTIR, XRD, SEM and TEM techniques were used. Additionally, the antimicrobial activity of the tested samples was assessed against six microorganisms including Gram-negative and Gram-positive bacteria. The prepared nanocoating formulas affirmed excellent antimicrobial activity as a broad-spectrum antimicrobial active agent with excellent activity against all representative microbial communities. The nanocoating with the highest ratio of Ka/ZnONPs (NCS@40 ka/ZnONPs) showed excellent antimicrobial activity with an inhibition percentage of more than 70% versus all microorganisms presented. The paper was coated with the prepared suspensions and characterized concerning optical, mechanical and physical properties. When Ka/ZnONPs were loaded into NCS in a variety of ratios, the characteristics of coated paper were enhanced compared to blank paper. The sample NCS@40 ka/ZnONPs increased tensile strength by 11%, reduced light scattering by 12%, and improved brightness and whiteness by 1%. Paper coated with NCh suspension had 35.32% less roughness and 188.6% less porosity. When coated with the sample NCS@10 ka/ZnONPs, the coated paper's porosity was reduced by 94% and its roughness was reduced by 10.85%. The greatest reduction in water absorptivity was attained by coating with the same sample, with a reduction percentage of 132%.


Subject(s)
Anti-Infective Agents , Metal Nanoparticles , Zinc Oxide , Metal Nanoparticles/chemistry , Zinc , Kaolin , Zinc Oxide/chemistry , Egypt , Anti-Infective Agents/pharmacology , Polysaccharides
4.
Biol Trace Elem Res ; 201(6): 3050-3059, 2023 Jun.
Article in English | MEDLINE | ID: mdl-35982260

ABSTRACT

Elements accumulation in crayfish is proportional to the increase in bioavailability (direct contact) with the surrounding water, sediment, and feeding. Five heavy metals (Cu, Cr, Mn, Ni, and Ag) and lithium (Li) were analyzed in the sediment, water, and crayfish tissues. Elements (heavy metals and lithium) concentrations in sediment, water, and crayfish tissues showed significant differences between the two sampling stations (El-Qanatir and El-Rahawi drain). However, the levels of elements in crayfish tissues were arranged in declining order as hepatopancreas > gills > exoskeleton > muscles for Cu and Cr; hepatopancreas > exoskeleton > gills > muscles for Ni and Ag; and exoskeleton > gills > hepatopancreas > muscles for Li and Mn. The human health hazard evaluation of heavy metals and lithium exposure via edible tissue consumption was assessed for both children and adult consumers. The target hazard quotient THQ values of crayfish edible tissues (less than 1) will not impose any health implications for consumers who ingest edible tissues in sufficient quantities. Furthermore, the hazard index (HI) values reported for children and adult consumers were lower than one, indicating non-carcinogenic and carcinogenic hazards, suggesting that crayfish edible tissues are safe for human ingestion. This evidence also found that Procambarus clarkii could be a good bio-indicator organism for monitoring potentially metals in aquatic systems.


Subject(s)
Metals, Heavy , Water Pollutants, Chemical , Child , Adult , Animals , Humans , Astacoidea , Rivers , Bioaccumulation , Egypt , Lithium , Environmental Monitoring , Water Pollutants, Chemical/analysis , Metals, Heavy/analysis , Water , Risk Assessment
5.
J Craniofac Surg ; 33(2): e187-e191, 2022.
Article in English | MEDLINE | ID: mdl-34608012

ABSTRACT

OBJECTIVES: This study aimed to assess the outcomes of bifocal transport distraction osteogenesis (BTDO) for closure of a wide or previously failed unilateral alveolar cleft. METHODS: Patient in this study had a large alveolar cleft that had not healed with bone grafts. Bone-borne distraction was used under general anesthesia. Intraoperative complications as bleeding and trauma to neighboring teeth were documented. Postoperative complications as wound dehiscence, paresthesia, infection, and bleeding were recorded. Complications including changes in bone segment movement, activation force loss, and occlusal interferences were observed during the activation phase. During the consolidation phase, problems including gingival recession, pulpal vitality, and cosmetic concerns were evaluated. Postoperative, periapical, occlusal, and orthopantomograms were used to evaluate bone gain and bone generation in the distracted area. RESULTS: Ten patients (6 males and 4 females) with unilateral alveolar cleft were included, with mean age of 9.5 ±â€Š2.5 years. Average cleft width was 12.25 ±â€Š2.54 mm. There was no intraoperative or postoperative bleeding. Only 1 patient had a wound dehiscence (10%). All patients had mild postoperative pain and edema in upper lip. Only 1 patient complained of numbness in infraorbital nerve's innervated region. Radiographs revealed bone formation in cleft area and bone healing in distracted chamber. CONCLUSIONS: Bifocal transport distraction osteogenesis improves success rate of an alveolar cleft treatment especially a wide or previously failed one. This technique associated with minimal complications when careful planning and cooperation from a patient are combined. It can be recommended when other modalities for alveolar cleft are failed. Patients also tolerate the device well.


Subject(s)
Cleft Lip , Cleft Palate , Osteogenesis, Distraction , Bone Transplantation/methods , Child , Cleft Lip/surgery , Cleft Palate/surgery , Female , Humans , Male , Osteogenesis, Distraction/methods , Radiography, Panoramic
6.
Appl Opt ; 60(3): 753-762, 2021 Jan 20.
Article in English | MEDLINE | ID: mdl-33690450

ABSTRACT

A novel nanocrescent antenna with polarization diversity is introduced. It is formed from a crescent-shaped patch fed with a coupled strip transmission line. The antenna is located on top of a SiO2 thin film with a shielding ground layer underneath. The structure is supported by an arbitrary substrate. Polarization of the radiated field can be adjusted to be along either one of the two orthogonal polarizations based on which one of the two crescent patch modes is going to be excited. The excitation of either one of these two modes of the patch is achieved by switching between the two propagating modes of the feeding coupled strip transmission line. Using a dual-polarized antenna allows doubling the optical communication system's capacity via frequency reuse. The new crescent antenna dimensions are optimized to satisfy several goals, such as minimizing the losses, the deviation of the main beam direction away from broadside, and maximizing the radiation efficiency and axial ratio. Through the optimization process, simple surrogate kriging models replace the detailed electromagnetic simulation. The optimal response is achieved by applying two different optimizers. The first optimizer employs the design-centering technique using normed distances. The multiobjective particle swarm with the preference ranking organization method for enrichment evaluations is used by the second optimizer. In order to identify the critical dimensions to which the nanoantenna is most sensitive, a sensitivity analysis is used. The optimized antenna is capable of switching its radiation between two orthogonal pure linear polarizations with maximum radiation along the broadside direction. The size of the proposed antenna is about 500nm×500nm. Its impedance-matching bandwidth is higher than 30 THz centered around 193 THz (1550 nm). Its gain and radiation efficiency are higher than 5.2 dBi and 85%, respectively, all over the working frequency band.

7.
Eur J Orthop Surg Traumatol ; 31(2): 375-381, 2021 Feb.
Article in English | MEDLINE | ID: mdl-32895737

ABSTRACT

PURPOSE: This is a purely observational study with a literature comparison to assess the effectiveness of radial and ulnar arteries propeller perforator-based flaps in post-traumatic soft tissue reconstruction and identify the risk factors for complications. METHODS: Sixteen patients were involved with post-traumatic wrist and hand soft tissue defects not exceeding 5 × 20 cm. Defects were covered with propeller radial and ulnar arteries perforator-based flaps. Patient demographics, soft tissue defects, complications and clinical outcomes were recorded. Assessment of patients' satisfaction for donor site morbidity and aesthetic outcome of the flap were performed. RESULTS: Radial artery propeller perforator flap was performed in seven cases, and ulnar artery propeller perforator flap was done in nine cases. The size of the skin paddle ranged from 2.5 × 5 cm to 4.5 × 10.5 cm. Primary closure of the donor site was performed in all cases. One flap was lost, while superficial epidermolysis occurred in seven cases (45%). Edge necrosis ranging between 3 and 7 mm occurred in nine cases (60%). Patients' factors, mode of injury, associated injuries and interval between trauma and coverage were all correlated with complication incidence. The patients' satisfaction for donor site morbidity was very good and good in 80% of patients, while satisfaction for aesthetic outcome of the flap was very good and good in only 40%. CONCLUSION: Radial and ulnar arteries have reliable perforators for flap elevation, which produce reliable outcome for small- and medium-sized soft tissue reconstruction. Effectiveness decreases in post-traumatic reconstructions. Complications are more frequent in crushing injuries especially if associated with bony fractures. Most complications in trauma cases were attributed to venous congestion, for which supercharging with a vein if accessible to the surgeon is recommended.


Subject(s)
Perforator Flap , Plastic Surgery Procedures , Soft Tissue Injuries , Humans , Reproducibility of Results , Soft Tissue Injuries/etiology , Soft Tissue Injuries/surgery , Treatment Outcome , Wrist , Wrist Joint
8.
Elife ; 92020 03 31.
Article in English | MEDLINE | ID: mdl-32228864

ABSTRACT

An extracellular matrix of Fibronectin adheres the neural tube to the two flanking columns of paraxial mesoderm and is required for normal vertebrate development. Here, we find that the bilaterally symmetric interfaces between the zebrafish neural tube and paraxial mesoderm function as optimally engineered adhesive lap joints with rounded edges, graded Fibronectin 'adhesive' and an arced adhesive spew filet. Fibronectin is a 'smart adhesive' that remodels to the lateral edges of the neural tube-paraxial mesoderm interfaces where shear stress is highest. Fibronectin remodeling is mechanically responsive to contralateral variation morphogenesis, and Fibronectin-mediated inter-tissue adhesion is required for bilaterally symmetric morphogenesis of the paraxial mesoderm. Strikingly, however, perturbation of the Fibronectin matrix rescues the neural tube convergence defect of cadherin 2 mutants. Therefore, Fibronectin-mediated inter-tissue adhesion dynamically coordinates bilaterally symmetric morphogenesis of the vertebrate trunk but predisposes the neural tube to convergence defects that lead to spina bifida.


In embryos, the spinal cord starts out as a flat sheet of cells that curls up to form a closed cylinder called the neural tube. The folding tube is attached to the surrounding tissues through an extracellular matrix of proteins and sugars. Overlapping strands of a protein from the extracellular matrix called Fibronectin connect the neural tube to adjacent tissues, like a kind of biological glue. However, it remained unclear what effect this attachment had on the embryonic development of the spinal cord. Connecting two overlapping objects with glue to form what is known as an 'adhesive lap joint' is common in fields such as woodworking and aeronautical engineering. The glue in these joints comes under shearing stress whenever the two objects it connects try to pull apart. But, thanks to work in engineering, it is possible to predict how different joints will perform under tension. Now, Guillon et al. have deployed these engineering principles to shed light on neural tube development. Using zebrafish embryos and computational models, Guillon et al. investigated what happens when the strength of the adhesive lap joints in the developing spine changes. This revealed that Fibronectin works like a smart adhesive: rather than staying in one place like a conventional glue, it moves around. As the neural tube closes, cells remodel the Fibronectin, concentrating it on the areas under the highest stress. This seemed to both help and hinder neural tube development. On the one hand, by anchoring the tube equally to the left and right sides of the embryo, the Fibronectin glue helped the spine to develop symmetrically. On the other hand, the strength of the adhesive lap joints made it harder for the neural tube to curl up and close. If the neural tube fails to close properly, it can lead to birth defects like spina bifida. One of the best-known causes of these birth defects in humans is a lack of a vitamin known as folic acid. Cell culture experiments suggest that this might have something to do with the mechanics of the cells during development. It may be that faulty neural tubes could close more easily if they were able to unglue themselves from the surrounding tissues. Further use of engineering principles could shed more light on this idea in the future.


Subject(s)
Fibronectins/physiology , Mesoderm/physiology , Morphogenesis , Neural Tube/growth & development , Spine/growth & development , Adhesives , Animals , Extracellular Matrix/physiology , Female , Humans , Male , Spine/anatomy & histology , Zebrafish/physiology
9.
RSC Adv ; 10(70): 42998-43009, 2020 Nov 23.
Article in English | MEDLINE | ID: mdl-35514936

ABSTRACT

Multitarget-directed drugs (hybrid drugs) constitute an efficient avenue for the treatment of multifactorial diseases. In this work, novel naphthalene hybrids with different heterocyclic scaffolds such as nicotinonitrile, pyran, pyranopyrazole, pyrazole, pyrazolopyridine, and azepine were efficiently synthesized via tandem reactions of 3-formyl-4H-benzo[h]chromen-4-one 1 with different nucleophilic reagents. Analysis of these hybrids using PASS online software indicated different predicted biological activities such as anticancer, antimicrobial, antiviral, antiprotozoal, anti-inflammatory, etc. By focusing on antitumor, anti-inflammatory, and antituberculosis activities, many compounds revealed remarkable activities. While 3c, 3e, and 3h were more potent than doxorubicin in the case of HepG-2 cell lines, 3a-e, 3i, 6, 8, 10, 11, and 12b were more potent in the case of MCF-7. Moreover, compounds 3c, 3h, 8, 10, 3d, and 12b manifested superior activity and COX-2 selectivity to the reference anti-inflammatory Celecoxib. Regarding antituberculosis activity, 3c, 3d, and 3i were found to be the most promising with MIC less than 1 µg mL-1. The molecular docking studies showed strong polar and hydrophobic interactions with the novel naphthalene-heterocycle hybrids that were compatible with experimental evaluations to a great extent.

10.
J Neurol Surg A Cent Eur Neurosurg ; 81(1): 44-47, 2020 Jan.
Article in English | MEDLINE | ID: mdl-31466105

ABSTRACT

OBJECTIVE: To describe our experience with the occurrence of intracranial acute subdural hematoma (ASDH) following spinal anesthesia. PATIENTS AND METHODS: We reviewed our records from 2010 to 2017 to detect cases of nontraumatic ASDH following spinal anesthesia. All cases were analyzed for the etiological factors, time lag between the procedure and hematoma diagnosis, treatment, and outcome. RESULTS: Of 329 cases of nontraumatic ASDH, we identified 6 patients whose spontaneous ASDH developed following spinal anesthesia. All our patients were obstetrical and received spinal anesthesia for delivery. Patient ages ranged from 21 to 34 years. Two patients presented with deterioration of consciousness a few hours after delivery. Three patients presented with persistent headache and lethargy days after delivery. One patient presented 3 days after delivery with severe deterioration of consciousness. All patients had undergone surgical evacuation of a hematoma. Five patients recovered and one patient died 2 days after surgery. Records showed none of the six patients had coagulopathy or any other blood disorder. CONCLUSION: Although uncommon, intracranial ASDH should be considered in patients following spinal anesthesia, especially those with a prolonged headache after the procedure.


Subject(s)
Anesthesia, Spinal/adverse effects , Brain/surgery , Hematoma, Subdural, Acute/etiology , Adult , Female , Hematoma, Subdural, Acute/surgery , Humans , Male , Neurosurgical Procedures , Treatment Outcome , Young Adult
11.
Drug Chem Toxicol ; 43(5): 504-513, 2020 Sep.
Article in English | MEDLINE | ID: mdl-30208729

ABSTRACT

The use of additives in different food products is growing up. It has attracted the attention towards the relation between the mutagenic potential of human diseases and food additives. Sunset yellow (SY) and sodium benzoate (NaB) are used as colorant and food additives worldwide. In the present study, genotoxic effects of different combinations of SY and NaB were assessed in vivo in female rats. Different combinations of SY and NaB were dissolved in water and administered daily to six animals groups for 12 weeks. Group 1 (control) received water, Group 2 received 5 mg/kg body weight (bw) SY plus 10 mg/kg bw NaB, group 3 received 5 mg/kg SY plus 100 mg/kg NaB, group 4 received 50 mg SY plus 100 mg/kg NaB, group 5 received 50 mg/kg SY plus 10 mg/kg NaB, group 6 received 200 mg/kg SY plus 750 mg/kg NaB, and group 7 received 20 mg/kg SY plus 75 mg/kg NaB. Genotoxicity investigations (Chromosomal aberration of bone marrow cells, Comet assay and DNA profile of liver cells) were carried out at the end of the experiment. Administration of 200 mg/kg SY plus 750 mg/kg NaB (group 6) induced the highest abnormalities percentage (1.5%) and showed structural abnormalities including end-to-end association, fragmentation, chromatid break, ring chromosome, and centric fusion break of chromosomes. Different combinations of SY and NaB induced an increase in the frequency of tailed nuclei (DNA damage) in liver cells. A concentration-dependent distinct DNA smear pattern was observed in the DNA isolated from liver cells of animals administered SY and NaB. In addition, administration of SY plus NaB resulted in an abnormal distribution of serum proteins. The results showed that the SY plus NaB could have genotoxic potential. With the increase applications of food additives, this study reported important data about screening the potential impacts.


Subject(s)
Azo Compounds/toxicity , DNA Damage , Food Coloring Agents/toxicity , Food Preservatives/toxicity , Sodium Benzoate/toxicity , Animals , Chromosome Aberrations/chemically induced , Comet Assay , Female , Rats
12.
Parasitol Res ; 118(12): 3519-3533, 2019 Dec.
Article in English | MEDLINE | ID: mdl-31673833

ABSTRACT

The main objective of this work is preparation of mesoporous silica nanoparticles loaded with praziquantel (PZQ-Si) in order to enhance the therapeutic efficacy of praziquantel (PZQ). Mice were experimentally infected with Schistosoma mansoni and treated 6 weeks post-infection with PZQ in different doses via either oral or intraperitoneal (IP) routes. PZQ in the same doses orally administered to S. mansoni-infected mice was used as a drug control, and infected and non-infected non-treated mice served as positive and negative controls, respectively. PZQ-Si exhibited good physicochemical attributes in terms of small uniform size (105 nm), spherical shape, and PZQ entrapment efficiency (83%). A maximum antischistosomal effect was achieved using orally administered PZQ-Si as reflected by total worm burden, tissue egg count, oogram pattern, and hepatic granuloma count and diameter. The biomarkers related to liver oxidative stress status and immunomodulatory effect (serum TNF-α and IL-10) were significantly improved. Data obtained implied that IP route was less efficacious for the delivery of PZQ-Si. Encapsulation of PZQ permits the reduction of the used therapeutic dose of PZQ. Hepatic DNA fragmentation, measured by comet assay, was significantly improved in infected mice treated with maximum dose of PZQ-Si as compared to positive or PZQ control groups. The results indicate that mesoporous silica NP is a promising safe nanocarrier for PZQ potentiating its antischistosomal, antioxidant, immunomodulatory, and anti-inflammatory action in animal model infected with S. mansoni. From a practical standpoint, PZQ-Si using a lower dose of PZQ could be suggested for effective PZQ antischistosomal mass chemotherapy.


Subject(s)
Anthelmintics/administration & dosage , Drug Carriers/chemistry , Drug Delivery Systems/methods , Praziquantel/administration & dosage , Schistosomiasis mansoni/drug therapy , Animals , Anthelmintics/chemistry , Anti-Inflammatory Agents/administration & dosage , Anti-Inflammatory Agents/chemistry , Disease Models, Animal , Humans , Liver/parasitology , Male , Mice , Nanoparticles/chemistry , Praziquantel/chemistry , Schistosoma mansoni/drug effects , Schistosoma mansoni/physiology , Schistosomiasis mansoni/parasitology , Silicon Dioxide/chemistry
13.
Saudi J Biol Sci ; 26(6): 1223-1226, 2019 Sep.
Article in English | MEDLINE | ID: mdl-31516352

ABSTRACT

Human infection with parasites is still one of the big problems worldwide. Medicinal plants succeeded to overcome a variety of protozoan and helminthic parasites. In this study, Salvadora persica root extracts (SE) were used to treat helminthosis and coccideosis. Three doses were used (200, 100 and 50 mg/ml) to study the anthelmintic activity of S. persica. Allolobophora caliginosa was used as a model worm. Also, Albendazole was used as a reference drug. In order to study the anticoccideal activity of SE, a group of mice were infected with Eimeria papillata sporulated oocysts. Experimental mice were treated with SE (300 mg/Kg) for 5 days. The extract was able to decrease the number of meronts and gamonts of the parasite in jejunum. Also, it regulates the level of glutathione and malondialdehyde and the activity of catalase as well. We conclude that S. persica possesses a powerful Anthelmintic, anticoccidial and antioxidant activity.

14.
Toxicol Rep ; 6: 727-735, 2019.
Article in English | MEDLINE | ID: mdl-31388500

ABSTRACT

Quercetin (QT) is a natural antioxidant materials that's possesses different type of pharmacological activities. In the current study, the protective effect QT against imidacloprid (IMD)-induced toxicity in rats was studied. The experiment included thirty-six adult male rats groups treated with QT, IMD (two different doses), their combinations and control non-treated group for 21 consecutive days. Different biochemical analysis (serum liver and kidney enzymes level, cholesterol and Glucose levels) were evaluated. DNA damage using comet assay and histopathological examination of different body organs were also screened. Treatment with IMD increased ALT, AST, serum urea, creatinine, cholesterol and Glucose levels but decreased the levels of serum total protein, albumin and body weight with induction in triacylglycerol and cholesterol levels. Animals treated with QT prior to IMD administration showed normal enzymatic levels which indicating a protective effect of QT. In addition, QT protected the different body organs from the histological changes and DNA damages induced by IMD toxicity. The present results showed the protective effect of QT as a natural material against the IMD induced toxicity at different doses.

15.
Bull Math Biol ; 81(8): 3301-3321, 2019 08.
Article in English | MEDLINE | ID: mdl-30788690

ABSTRACT

Cell migration plays an important role in physiology and pathophysiology. It was observed in the experiments that cells, such as fibroblast, leukocytes, and cancer cells, exhibit a wide variety of migratory behaviors, such as persistent random walk, contact inhibition of locomotion, and ordered behaviors. To identify biophysical mechanisms for these cellular behaviors, we developed a rigorous computational model of cell migration on a two-dimensional non-deformable substrate. Cells in the model undergo motion driven by mechanical interactions between cellular protrusions and the substrate via the balance of tensile forces. Properties of dynamic formation of lamellipodia induced the persistent random walk behavior of a migrating cell. When multiple cells are included in the simulation, the model recapitulated the contact inhibition of locomotion between cells at low density without any phenomenological assumptions or momentum transfer. Instead, the model showed that contact inhibition of locomotion can emerge via indirect interactions between the cells through their interactions with the underlying substrate. At high density, contact inhibition of locomotion between numerous cells gave rise to confined motions or ordered behaviors, depending on cell density and how likely lamellipodia turn over due to contact with other cells. Results in our study suggest that various collective migratory behaviors may emerge without more restrictive assumptions or direct cell-to-cell biomechanical interactions.


Subject(s)
Cell Movement/physiology , Contact Inhibition/physiology , Models, Biological , Animals , Biomechanical Phenomena , Biophysical Phenomena , Cell Communication/physiology , Cell Count , Cell Polarity/physiology , Computer Simulation , Humans , Mathematical Concepts , Pseudopodia/physiology , Systems Biology
16.
RSC Adv ; 9(48): 27996-28005, 2019 Sep 03.
Article in English | MEDLINE | ID: mdl-35558993

ABSTRACT

A new promising protocol has been developed for the synthesis of scarce oxocine derivatives 3a-e and 6 through addition of amine-based nucleophiles such as hydroxylamine hydrochloride, primary amine and hydrazide to chromonylidene benzothiazol-2-ylacetonitrile 2 in refluxing dioxane under metal free reaction conditions in moderate to good yields. Other nitrogen nucleophiles such as piperidine, hydrazine and thiosemicarbazide failed to afford the corresponding oxocinols, and instead pyridine derivatives 7, 8 and 10 were obtained exclusively. Predictive study for the biological activities using PASS (prediction of activity spectra for biologically active substances) online software showed optimistic activities for oxocinols 3a-e in the treatment of cancer, influenza A and microbial infections. Additionally, DFT studies of oxocine derivatives 3a-e and 6 indicated the presence of required thermodynamics parameters for the application in dye-sensitized solar cells (DSSCs).

17.
ACS Biomater Sci Eng ; 5(8): 3954-3963, 2019 Aug 12.
Article in English | MEDLINE | ID: mdl-32676537

ABSTRACT

Cell migration is a fundamental process in biological systems, playing an important role for diverse physiological processes. Cells often exhibit directed migration in a specific direction in response to various types of cues. In particular, cells are able to sense the rigidity of surrounding environments and then migrate toward stiffer regions. To understand this mechanosensitive behavior called durotaxis, several computational models have been developed. However, most of the models employed cell decision making to recapitulate durotactic behaviors, significantly limiting insights provided from these studies. In this study, we developed a computational biomechanical model without any cell decision making to illuminate intrinsic mechanisms of durotactic behaviors of cells migrating on a two-dimensional substrate. The model consists of a simplified cell generating contractile forces and a deformable substrate coarse-grained into an irregular triangulated mesh. Using the model, we demonstrated that durotactic behaviors emerge from purely mechanical interactions between the cell and the underlying substrate. We investigated how durotactic migration is regulated by biophysical properties of the substrate, including elasticity, viscosity, and stiffness profile.

18.
Arch Bone Jt Surg ; 6(3): 189-195, 2018 May.
Article in English | MEDLINE | ID: mdl-29911135

ABSTRACT

BACKGROUND: The importance of the syndesmosis in ankle stability is well recognized. Numerous means of fixation have been described for syndesmotic injuries including the suture button technique. Significant cost limits the use the commercially available options. We, therefore, designed a cheap and readily available alternative construct. We aim to assess the results of using a novel suture-button construct in treatment of syndesmotic ankle injuries. METHODS: Fifty-two patients (34 males and 18 females) fulfilled our inclusion/exclusion criteria. Five patients were lost to follow-up. The remaining 47 patients were successfully followed up for a minimum of 24 months. The pre and post-surgery American Orthopedic Foot and Ankle Society scores (AOFAS) together with reported complications and post-operative radiological analysis were assessed. In this innovative construct, we utilized polyester braided surgical sutures jointly with double mini two- holed plates, a No.2 polygalactin 910 suture, a 4 mm drill bit, together with a 15 cm long suture needle with slotted end. This technique was supported with the use of the image intensifier. RESULTS: The AOFAS score improved significantly from a mean of 32.4 to 94.2 (P<0.004). Radiologically, the medial clear space (MCS), tibio-fibular clear space (TFCS) (P=0.05) and tibio-fibular overlap (TFO) measurements showed a significant improvement postoperatively (P=0.02). Patients reported good satisfaction rates with a 96% success rate (95% CI: 94.0% to 99.3%). CONCLUSION: We have observed that this low cost suture button construct is a simple, safe and cost effective treatment option for acute syndesmotic injuries.

19.
Br J Hosp Med (Lond) ; 79(5): 284-287, 2018 May 02.
Article in English | MEDLINE | ID: mdl-29727232

ABSTRACT

Background Neck of femur fractures and their subsequent operative fixation are associated with high rates of perioperative morbidity and mortality. Consenting in this setting is suboptimal with the Montgomery court ruling changing the perspective of consent. This quality improvement project assessed the adequacy of consenting against British Orthopaedic Association-endorsed guidance and implemented a series of changes to improve the documentation of risks associated with surgery for fractured neck of femur. Methods Seventy consecutive patients who underwent any operative fixation of a neck of femur fracture were included over a 6-month period at a single centre. Patients unable to consent or without electronic notes were excluded. Consent forms were analysed and the documented potential risks or complications associated with surgery were compared to British Orthopaedic Association-endorsed guidance. A series of changes (using the plan, do study, act (PDSA) approach) was implemented to improve the adequacy of consent. Results Documentation of four out of 12 potential risks or complications was recorded in <50% of cases for patients with intracapsular fractures (n=35), and documentation of seven out of 12 potential risks or complications was recorded in <50% of cases for patients with extracapsular fractures (n=35). Re-audit following raising awareness and attaching consent guidance showed 100% documentation of potential risks or complications in patients with intracapsular and extracapsular fractures (n=70). A neck of femur fracture-specific consent form has been implemented which will hopefully lead to sustained improvement. Conclusions Consenting patients with fractured neck of femur for surgery in the authors' unit was suboptimal when compared to British Orthopaedic Association-endorsed consent guidance. This project has shown that ensuring such guidance is readily available has improved the adequacy of consent. The authors hope that introduction of a neck of femur fracture-specific consent form within their unit will lead to sustained adequate documentation of risks associated with surgery.


Subject(s)
Consent Forms , Femoral Neck Fractures/surgery , Fracture Fixation/adverse effects , Postoperative Complications , Quality Improvement/organization & administration , Risk Management , Consent Forms/standards , Consent Forms/statistics & numerical data , Fracture Fixation/methods , Humans , Medical Audit , Postoperative Complications/classification , Postoperative Complications/etiology , Practice Guidelines as Topic , Risk Management/methods , Risk Management/organization & administration , United Kingdom
20.
Materials (Basel) ; 10(10)2017 Oct 15.
Article in English | MEDLINE | ID: mdl-29036935

ABSTRACT

Laser cladding process was performed on a commercial Ti-6Al-4V (α + ß) titanium alloy by means of tungsten carbide-nickel based alloy powder blend. Nd:YAG laser with a 2.2-KW continuous wave was used with coaxial jet nozzle coupled with a standard powder feeding system. Four-track deposition of a blended powder consisting of 60 wt % tungsten carbide (WC) and 40 wt % NiCrBSi was successfully made on the alloy. The high content of the hard WC particles is intended to enhance the abrasion resistance of the titanium alloy. The goal was to create a uniform distribution of hard WC particles that is crack-free and nonporous to enhance the wear resistance of such alloy. This was achieved by changing the laser cladding parameters to reach the optimum conditions for favorable mechanical properties. The laser cladding samples were subjected to thorough microstructure examinations, microhardness and abrasion tests. Phase identification was obtained by X-ray diffraction (XRD). The obtained results revealed that the best clad layers were achieved at a specific heat input value of 59.5 J·mm-2. An increase by more than three folds in the microhardness values of the clad layers was achieved and the wear resistance was improved by values reaching 400 times.

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