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1.
ACS Appl Bio Mater ; 2024 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-38728425

RESUMO

Recently, different alternative regulated cell death (RCD) pathways, viz., necroptosis, pyroptosis, ferroptosis, cuproptosis etc., have been explored as important targets for the development of cancer medications in recent years, as these can change the immunogenicity of the tumor microenvironment (TME) and will finally lead to the inhibition of cancer progression and metastasis. Here, we report the development of transferrin immobilized graphene oxide (Tfn@GOAPTES) nanocomposite as a therapeutic strategy toward cancer cell killing. The electrostatic immobilization of Tfn on the GOAPTES surface was confirmed by different spectroscopy and microscopy techniques. The Tfn immobilization was found to be ∼74 ± 4%, whereas the stability of the protein on the GO surface suggested a robust nature of the nanocomposite. The MTT assay suggested that Tfn@GOAPTES exhibited cytotoxicity toward HeLa cells via increased lipid peroxidation and DNA damage. Western blot studies resulted in decreased expression of acetylation on lysine 40 of α-tubulin and increased expression of LC3a/b for Tfn@GOAPTES treated HeLa cells, suggesting autophagy to be the main cause of the cell death mechanism. Overall, we predict that the present approach can be used as a therapeutic strategy for cancer cell killing via selective induction of a high concentration of intracellular iron.

2.
Int J Biol Macromol ; 266(Pt 1): 131108, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38531523

RESUMO

Protein aggregation is a multifaceted phenomenon prevalent in the progression of neurodegenerative diseases, yielding aggregates of diverse sizes. Recently, increased attention has been directed towards early protein aggregates due to their pronounced toxicity, largely stemming from inflammation mediated by reactive oxygen species (ROS). This study advocates for a therapeutic approach focusing on inflammation control rather than mere ROS inhibition in the context of neurodegenerative disorders. Here, we introduced Camellia sinensis cellulose nanoonion (CS-CNO) as an innovative, biocompatible nanocarrier for encapsulating the phytosteroid diosgenin (DGN@CS-CNO). The resulting nano-assembly, manifesting as spherical entities with dimensions averaging ~180-220 nm, exhibits a remarkable capacity for the gradual and sustained release of approximately 39-44 % of DGN over a 60-hour time frame. DGN@CS-CNO displays a striking ability to inhibit or disassemble various phases of hen egg white lysozyme (HEWL) protein aggregates, including the early (HEWLEA) and late (HEWLLA) stages. In vitro experiments employing HEK293 cells underscore the potential of DGN@CS-CNO in mitigating cell death provoked by protein aggregation. This effect is achieved by ameliorating ROS-mediated inflammation and countering mitochondrial dysfunction, as evidenced by alterations in TNFα, TLR4, and MT-CO1 protein expression. Western blot analyses reveal that the gradual and sustained release of DGN from DGN@CS-CNO induces autophagy, a pivotal process in dismantling intracellular amyloid deposits. In summary, this study not only illuminates a path forward but also presents a compelling case for the utilization of phytosteroid as a formidable strategy against neuroinflammation incited by protein aggregation.


Assuntos
Autofagia , Celulose , Diosgenina , Mitocôndrias , Agregados Proteicos , Humanos , Autofagia/efeitos dos fármacos , Celulose/química , Celulose/farmacologia , Celulose/análogos & derivados , Diosgenina/farmacologia , Diosgenina/química , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Agregados Proteicos/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo , Células HEK293 , Morte Celular/efeitos dos fármacos , Muramidase/metabolismo , Muramidase/química , Animais , Nanopartículas/química , Portadores de Fármacos/química , Regulação para Cima/efeitos dos fármacos
3.
Small ; : e2308580, 2024 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-38225699

RESUMO

The progression of self-powered micro/-nanomotors (MNMs) has rapidly evolved over the past few decades, showing applications in various fields such as nanotechnology, biomedical engineering, microfluidics, environmental science, and energy harvesting. Miniaturized MNMs transduce chemical/biochemical energies into mechanical motion for navigating through complex fluidic environments with directional control via external forces fields such as magnetic, photonic, and electric stimuli. Among various propulsion mechanisms, buoyancy-driven MNMs have received noteworthy recognition due to their simplicity, efficiency, and versatility. Buoyancy force-driven motors harness the principles of density variation-mediated force to overcome fluidic resistance to navigate through complex environments. Restricting the propulsion in one direction helps to control directional movement, making it more efficient in isotropic solutions. The changes in pH, ionic strength, chemical concentration, solute gradients, or the presence of specific molecules can influence the motion of buoyancy-driven MNMs as evidenced by earlier reports. This review aims to provide a fundamental and detailed analysis of the current state-of-the-art in buoyancy-driven MNMs, aiming to inspire further research and innovation in this promising field.

4.
RSC Adv ; 13(41): 28767-28772, 2023 Sep 26.
Artigo em Inglês | MEDLINE | ID: mdl-37790108

RESUMO

The ability of bacteria to facilitate fabrication of nanomaterials has been adapted towards bacterial sensing applications. In this work, we fabricate spherical, cubic and truncated octahedron topologies of Cu2O nanoparticles via E. coli-facilitated redox reaction in an electrochemical setup. The Cu2O nanoparticles exhibit cytochrome c oxidase-like activity with the spherical topology displaying higher catalytic rate compared to the other geometries. The topology-dependent catalytic behavior of Cu2O nanoparticles has not been reported previously. The Cu2O nanozymes also display E. coli killing activity in a topology-correlated manner. The E. coli mediated redox reaction in an electrochemical setup is being reported for the first time for synthesis of different topologies of Cu2O which also exert a variable antibacterial effect.

5.
Colloids Surf B Biointerfaces ; 232: 113583, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37844474

RESUMO

Infectious diseases resulting from the high pathogenic potential of several bacteria possesses a major threat to human health and safety. Traditional methods used for screening of these microorganisms face major issues with respect to detection time, selectivity and specificity which may delay treatment for critically ill patients past the optimal time. Thus, a convincing and essential need exists to upgrade the existing methodologies for the fast detection of bacteria. In this context, increasing number of newly emerging nanomaterials (NMs) have been discovered for their effective use and applications in the area of diagnosis in bacterial infections. Recently, functional fluorescent nanomaterials (FNMs) are extensively explored in the field of biomedical research, particularly in developing new diagnostic tools, nanosensors, specific imaging modalities and targeted drug delivery systems for bacterial infection. It is interesting to note that organic fluorophores and fluorescent proteins have played vital role for imaging and sensing technologies for long, however, off lately fluorescent nanomaterials are increasingly replacing these due to the latter's unprecedented fluorescence brightness, stability in the biological environment, high quantum yield along with high sensitivity due to enhanced surface property etc. Again, taking advantage of their photo-excitation property, these can also be used for either photothermal and photodynamic therapy to eradicate bacterial infection and biofilm formation. Here, in this review, we have paid particular attention on summarizing literature reports on FNMs which includes studies detailing fluorescence-based bacterial detection methodologies, antibacterial and antibiofilm applications of the same. It is expected that the present review will attract the attention of the researchers working in this field to develop new engineered FNMs for the comprehensive diagnosis and treatment of bacterial infection and biofilm formation.


Assuntos
Infecções Bacterianas , Nanoestruturas , Humanos , Nanoestruturas/uso terapêutico , Infecções Bacterianas/diagnóstico , Infecções Bacterianas/tratamento farmacológico , Diagnóstico por Imagem/métodos , Corantes Fluorescentes , Bactérias , Biofilmes
6.
Int J Biol Macromol ; 253(Pt 2): 126821, 2023 Dec 31.
Artigo em Inglês | MEDLINE | ID: mdl-37690655

RESUMO

Neurodegenerative diseases (NDs) are characterized by progressive degeneration of neurons which deteriorates the brain functions. An early detection of the onset of NDs is utmost important, as it will provide the fast treatment strategies to prevent further progression of the disease. Conventionally, accurate diagnosis of the brain related disorders is difficult in their early phase. To solve this problem, nanotechnology based neurofunctional imaging and biomarker detection techniques have been developed which allows high specificity and sensitivity towards screening and diagnosis of NDs. Another challenge to treat the brain related disorders is to overcome the complex integrity of blood-brain-barrier (BBB) for the delivery of theranostic agents. Fortunately, utilization of nanomaterials has been pursued as promising strategy to address this challenge. Herein, we critically highlighted the recent improvements in the field of neurodiagnostic and therapeutic approaches involving innovative strategies for diagnosis, and inhibition of protein aggregates. We have provided particular emphasis on the use of nanotechnology which can push forward the blooming research growth in this field to win the battle against devastating NDs.


Assuntos
Nanoestruturas , Doenças Neurodegenerativas , Humanos , Doenças Neurodegenerativas/metabolismo , Nanotecnologia/métodos , Barreira Hematoencefálica/metabolismo , Transporte Biológico
8.
Phys Rev Lett ; 130(24): 241601, 2023 Jun 16.
Artigo em Inglês | MEDLINE | ID: mdl-37390439

RESUMO

Bjorken flow is among the simplest models of fluids moving near the speed of light (c), while Carroll symmetry arises as a contraction of Poincaré group when c→0. We show that Bjorken flow and its phenomenological approximations are completely captured by Carrollian fluids. Carrollian symmetries arise on generic null surfaces, and a fluid moving at c is restricted to such a surface, thereby naturally inheriting the symmetries. Carrollian hydrodynamics is, thus, not exotic, but rather ubiquitous, and provides a concrete framework for fluids moving at or near the speed of light.

9.
PLoS Negl Trop Dis ; 17(5): e0011276, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-37163529

RESUMO

Visceral leishmaniasis (VL) is a vector-borne protozoan disease, which can be fatal if left untreated. Synthetic chemical insecticides are very effective tools for controlling of insect vectors, including the sand fly Phlebotomus argentipes, the vector of VL in the Indian subcontinent. However, repeated use of the same insecticide with increasing doses potentially can create high selection pressure and lead to tolerance and resistance development. The objective of this study was to determine the lethal concentrations and assess levels of susceptibility, diagnostic doses and times to death of laboratory-reared P. argentipes to five insecticides that are used worldwide to control vectors. Using the Center for Disease Control and Prevention (CDC) bottle bioassay, 20-30 sand flies were exposed in insecticide- coated 500-ml glass bottles. Flies were then observed for 24 hours and mortality was recorded. Dose-response survival curves were generated for each insecticide using QCal software and lethal concentrations causing 50%, 90% and 95% mortality were determined. A bioassay was also conducted to determine diagnostic doses and diagnostic times by exposing 20-30 flies in each bottle containing set concentrations of insecticide. Mortality was recorded at 10-minute intervals for 120 minutes to generate the survival curve. Phlebotomus argentipes are highly susceptible to alpha-cypermethrin, followed by deltamethrin, malathion, chlorpyrifos, and least susceptible to DDT. Also, the lowest diagnostic doses and diagnostic times were established for alpha-cypermethrin (3µg/ml for 40 minutes) to kill 100% of the flies. The susceptibility data, diagnostic doses and diagnostic times presented here will be useful as baseline reference points for future studies to assess insecticide susceptibility and resistance monitoring of field caught sand flies and to assist in surveillance as VL elimination is achieved in the region.


Assuntos
Inseticidas , Leishmaniose Visceral , Phlebotomus , Psychodidae , Animais , Estados Unidos , Inseticidas/farmacologia , Phlebotomus/fisiologia , Leishmaniose Visceral/prevenção & controle , Resistência a Inseticidas , Índia , Bioensaio , Centers for Disease Control and Prevention, U.S.
10.
Chembiochem ; 24(10): e202300067, 2023 05 16.
Artigo em Inglês | MEDLINE | ID: mdl-36862065

RESUMO

Functional DNA hydrogels with various motifs and functional groups require perfect sequence design to avoid cross-bonding interference with themselves or other structural sequences. This work reports an A-motif functional DNA hydrogel that does not require any sequence design. A-motif DNA is a noncanonical parallel DNA duplex structure containing homopolymeric deoxyadenosines (poly-dA) strands that undergo conformation changes from single strands at neutral pH to a parallel duplex DNA helix at acidic pH. Despite this and other advantages over other DNA motifs like no cross-bonding interference with other structural sequences, the A-motif has not been explored much. We successfully synthesized a DNA hydrogel by using an A-motif as a reversible handle to polymerize a DNA three-way junction. The A-motif hydrogel was initially characterized by electrophoretic mobility shift assay, and dynamic light scattering, which showed the formation of higher-order structures. Further, we used imaging techniques like atomic force microscopy and scanning electron microscope to validating its hydrogel like highly branched morphology. pH-induced conformation transformation from monomers to gel is quick and reversible, and was analysed for multiple acid-base cycles. The sol-to-gel transitions and gelation properties were further examined in rheological studies. The use of the A-motif hydrogel in the visual detection of pathogenic target nucleic acid sequence was demonstrated for the first time in a capillary assay. Moreover, pH-induced hydrogel formation was observed in situ as a layer over the mammalian cells. The proposed A-motif DNA scaffold has enormous potential in designing stimuli-responsive nanostructures that can be used for many biological applications.


Assuntos
Hidrogéis , Nanoestruturas , Animais , Hidrogéis/química , DNA/química , Motivos de Nucleotídeos , Nanoestruturas/química , Concentração de Íons de Hidrogênio , Mamíferos
11.
Int J Biol Macromol ; 233: 123466, 2023 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-36739044

RESUMO

Developing metal-free carbon nanozyme for tumor hypoxia is difficult. In biomedical applications, especially in the case of biomolecular detection, extensive research has been done on nanozymes with enzyme-mimicking catalytic activity. However, there are considerably fewer investigations on targeted nano-catalytic tumor therapy. Nano catalytic medicine-enabled chemotherapy is a safe and promising treatment strategy that involves the conversion of excess H2O2 into O2 in a tumor environment. Here we have synthesized carbon nanosphere (CNS) using the Camellia sinensis plant (CS-CNS). Further surface functionalization was achieved via nitrilotriacetic acid conjugation (NTA@CS-CNS). A stability study of synthesized nanozyme in the presence of various cations, anions, and 5 different pH range suggested the robustness of carbon based nanoassembly. The catalytic in vitro study shows that NTA@CS-CNS mimics peroxidase and catalase using TMB and H2O2 as substrates. NTA@CS-CNS showed Km and Vmax values of ~ 193.2 µM and 0.43 µM/s, ~ 413 µM and 1.42 µM/s, and ~ 378 µM and 1.63 µM/s, respectively when H2O2 and TMB was used for CAT and POD activity. Results showed that NTA@CS-CNS in combination with SFN and laser irradiation reduces hypoxia. Hence, our study could pave the path for the development of different non-toxic nano catalytic therapy for tumors in cancerous cells.


Assuntos
Nanosferas , Neoplasias , Humanos , Peróxido de Hidrogênio/química , Carbono/química , Neoplasias/tratamento farmacológico , Hipóxia
12.
ACS Appl Bio Mater ; 6(1): 117-125, 2023 01 16.
Artigo em Inglês | MEDLINE | ID: mdl-36503255

RESUMO

With the continuous growth in world population and economy, the global energy demand is increasing rapidly. Given that non-renewable energy sources will eventually deplete, there is increasing need for clean, alternative renewable energy sources, which will be inexpensive and involve minimum risk of environmental pollution. In this paper, harnessing the activity of cupric reductase NDH-2 enzyme present in Escherichia coli bacterial cells, we demonstrate a simple and efficient energy harvesting strategy within an electrochemical chamber without the requirement of any external fuels or force fields. The transduction of energy has been demonstrated with various strains of E. coli, indicating that this strategy could, in principle, be applicable for other microbial catalytic systems. We offer a simple mechanism of the energy transduction process considering the bacterial enzyme-mediated redox reaction occurring over the working electrode of the electrochemical cell. Also, the amount of energy generated has been found to be depending on the motility of bacteria within the experimental chamber, suggesting possible opportunities for developing microbial motility-controlled small scale power generators. Finally, we show that the Faradaic electrochemical energy harvested is large enough to power a commercial light emitting diode connected to an amplifier circuit. We expect the present study to generate sufficient interest within soft condensed matter and biophysics communities, and offer useful platforms for controlled energy generation at the small scales.


Assuntos
Bactérias , Escherichia coli , Oxirredução
13.
JACC Case Rep ; 4(19): 1247-1251, 2022 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-36406925

RESUMO

Left ventricular outflow tract obstruction (LVOTO) can complicate percutaneous mitral valve replacement and may preclude patients considered high surgical risk from transcatheter therapies. We report a case of mitral valve-in-valve procedure in a patient at high risk for LVOTO. (Level of Difficulty: Advanced.).

14.
PLoS Negl Trop Dis ; 16(10): e0010347, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-36264975

RESUMO

Leishmaniasis on the Indian subcontinent is thought to have an anthroponotic transmission cycle. There is no direct evidence that a mammalian host other than humans can be infected with Leishmania donovani and transmit infection to the sand fly vector. The aim of the present study was to evaluate the impact of sand fly feeding on other domestic species and provide clinical evidence regarding possible non-human reservoirs through experimental sand fly feeding on cows, water buffalo goats and rodents. We performed xenodiagnosis using colonized Phlebotomus argentipes sand flies to feed on animals residing in villages with active Leishmania transmission based on current human cases. Xenodiagnoses on mammals within the endemic area were performed and blood-fed flies were analyzed for the presence of Leishmania via qPCR 48hrs after feeding. Blood samples were also collected from these mammals for qPCR and serology. Although we found evidence of Leishmania infection within some domestic mammals, they were not infectious to vector sand flies. Monitoring infection in sand flies and non-human blood meal sources in endemic villages leads to scientific proof of exposure and parasitemia in resident mammals. Lack of infectiousness of these domestic mammals to vector sand flies indicates that they likely play no role, or a very limited role in Leishmania donovani transmission to people in Bihar. Therefore, a surveillance system in the peri-/post-elimination phase of visceral leishmaniasis (VL) must monitor absence of transmission. Continued surveillance of domestic mammals in outbreak villages is necessary to ensure that a non-human reservoir is not established, including domestic mammals not present in this study, specifically dogs.


Assuntos
Leishmania donovani , Leishmaniose Visceral , Leishmaniose , Phlebotomus , Psychodidae , Feminino , Bovinos , Humanos , Cães , Animais , Leishmaniose Visceral/epidemiologia , Gado , Roedores
15.
Free Radic Biol Med ; 193(Pt 1): 238-252, 2022 11 20.
Artigo em Inglês | MEDLINE | ID: mdl-36257485

RESUMO

Mitochondrial dysfunction has been reported to be one of the main causes of many diseases including cancer, type2 diabetes, neurodegenerative disorders, cardiac ischemia, sepsis, muscular dystrophy, etc. Under in vitro conditions, Cytochrome C (Cyt C) maintains mitochondrial homeostasis and stimulates apoptosis, along with being a key participant in the life-supporting function of ATP synthesis. Hence, the medicinal importance of Cyt C as catalytic defense is immensely important in various mitochondrial disorders. Here, we have developed a nanomaterial via electrostatically conjugating oxidized single-wall carbon nanotube with Cyt C (Cyt C@cSWCNT) for the exogenous delivery of Cyt C. The chemical and morphological characterization of the developed Cyt C@cSWCNT was done using UV-vis, FTIR, XPS, powder XRD, TGA/DSC, TEM, etc. The developed Cyt C@cSWCNT exhibited bifunctional catalase and peroxidase activity with Km (∼ 642.7 µM and 351.6 µM) and Vmax (∼0.33 µM/s and 2.62 µM/s) values, respectively. Also, through this conjugation Cyt C was found to retain its catalytic activity even at 60 °C, excellent catalytic recyclability (at least up to 3 times), and wider pH activity (pH = 3 to 9). Cyt C@cSWCNT was found to promote intracellular ROS quenching and maintain mitochondrial membrane potential and cellular membrane integrity via Na+/K+ ion homeostasis during the H2O2 stress. Overall the present strategy provides an alternative approach for the exogenous delivery of Cyt C which can be used as nano catalytic medicine.


Assuntos
Citocromos c , Nanotubos de Carbono , Humanos , Citocromos c/metabolismo , Peróxido de Hidrogênio/metabolismo , Estresse Oxidativo , Mitocôndrias/metabolismo
16.
Comput Intell Neurosci ; 2022: 4411876, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36093479

RESUMO

The focus of this research is to isolating and identifying bacteria that produce calcite precipitate, as well as determining whether or not these bacteria are suitable for incorporation into concrete in order to enhance the material's strength and make the environment protection better. In order to survive the high "potential of hydrogen" of concrete, microbes that are going to be added to concrete need to be able to withstand alkali, and they also need to be able to develop endospores so that they can survive the mechanical forces that are going to be put on the concrete while it is being mixed. In order to precipitate CaCO3 in the form of calcite, they need to have a strong urease activity. Both Bacillus sphaericus and the Streptococcus aureus bacterial strains were evaluated for their ability to precipitate calcium carbonate (CaCO3). These strains were obtained from the Department of Biotechnology at GLA University in Mathura. This research aims to solve the issue of augmenting the tension and compression strengths of concrete by investigating possible solutions for environmentally friendly concrete. The sterile cultures of the microorganisms were mixed with water, which was one of the components of the concrete mixture, along with the nutrients in the appropriate proportions. After that, the blocks were molded, and then pond-cured for 7, 28, 56, 90, 120, 180, 270, and 365 days, respectively, before being evaluated for compressibility and tensile strength. An investigation into the effect that bacteria have on compression strength was carried out, and the outcomes of the tests showed that bacterial concrete specimens exhibited an increase in mechanical strength. When compared to regular concrete, the results showed a maximum increase of 16 percent in compressive strength and a maximum increase of 12 percent in split tensile strength. This study also found that both bacterial concrete containing 106, 107, and 108 cfu/ml concentrations made from Bacillus sphaericus and Streptococcus aureus bacteria gave better results than normal concrete. Both cluster analysis (CA) and regression analysis (RA) were utilized in this research project in order to measure and analyze mechanical strength.


Assuntos
Bacillaceae , Materiais de Construção , Bacillaceae/metabolismo , Bactérias/metabolismo , Carbonato de Cálcio/metabolismo , Materiais de Construção/análise , Materiais de Construção/microbiologia , Humanos , Análise de Regressão
17.
J Clin Transl Hepatol ; 9(6): 878-888, 2021 Dec 28.
Artigo em Inglês | MEDLINE | ID: mdl-34966651

RESUMO

BACKGROUND AND AIMS: The impact of coronavirus disease-2019 (COVID-19) on liver function remains to be fully elucidated. This study was designed to investigate such and determine the clinical significance in determining mortality risk. METHODS: A retrospective study was conducted in patients with COVID-19 from March 2020 to July 2020. Clinical details were retrieved from electronic medical records to obtain clinical characteristics, medical history, laboratory tests, therapeutic intervention, and outcome data. RESULTS: A total of 184 patients with COVID-19 were included (median age: 45.5 years), comprised of 62.5% men. In total, 22 (12.0%) patients had severe infection and 162 (88.0%) had mild to moderate infection. Overall, 95 (51.6%) showed abnormal liver function test (LFT) and 17 (9.2%) showed normal LFT at admission. The median age, hospital stay, and LFT were significantly higher in severe vs. non-severe infection (p<0.001). Out of 12 deaths, the majority were due to severe infection (n=11). Deaths were also due to acute respiratory distress syndrome (n=5), cardiac reasons (n=3), and sepsis with multiorgan failure (n=3). The median age, hospital stay and number of intensive care unit admissions were higher in patients having abnormal LFT compared to normal LFT. Incidence of elevated aspartate aminotransferase (42.8% and 40.4%), alanine transaminase (43.7% and 41.6%), and hypoalbuminemia (71.4% and72.7%) at admission and discharge were more common in severe infection. The mean survival was significantly lower in severe infection compared to those with non-severe disease (17.2 vs. 52.3 days; p<0.001). CONCLUSIONS: Incidence of abnormal liver function was higher in patients with severe COVID-19 and was associated with prolonged hospital stay; mortality was associated with severity of COVID-19. For ruling out the risk of liver injury, it is crucial to vigilantly monitor the liver function parameters in patients with COVID-19 admitted to hospital.

18.
Micromachines (Basel) ; 12(10)2021 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-34683302

RESUMO

Gaseous oxygen plays a vital role in driving the metabolism of living organisms and has multiple agricultural, medical, and technological applications. Different methods have been discovered to produce oxygen, including plants, oxygen concentrators and catalytic reactions. However, many such approaches are relatively expensive, involve challenges, complexities in post-production processes or generate undesired reaction products. Catalytic oxygen generation using hydrogen peroxide is one of the simplest and cleanest methods to produce oxygen in the required quantities. Chemically powered micro/nanomotors, capable of self-propulsion in liquid media, offer convenient and economic platforms for on-the-fly generation of gaseous oxygen on demand. Micromotors have opened up opportunities for controlled oxygen generation and transport under complex conditions, critical medical diagnostics and therapy. Mobile oxygen micro-carriers help better understand the energy transduction efficiencies of micro/nanoscopic active matter by careful selection of catalytic materials, fuel compositions and concentrations, catalyst surface curvatures and catalytic particle size, which opens avenues for controllable oxygen release on the level of a single catalytic microreactor. This review discusses various micro/nanomotor systems capable of functioning as mobile oxygen generators while highlighting their features, efficiencies and application potentials in different fields.

19.
Case Rep Med ; 2021: 6658083, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33859700

RESUMO

INTRODUCTION: Fecal abscess or enterocutaneous fistulas of the scrotum are rare and are invariably the result of incarcerated bowel loop in inguinal hernia. Spontaneous perforation of the colon (SPC) having no definite cause is also rare. Much rarer is posterior colonic perforations causing an extensively large retroperitoneal abscess. Similarly, spread of retroperitoneal abscess to the thigh or scrotum has rarely been reported. We report a case of spontaneous posterior perforation of ascending colon resulting in large retroperitoneal abscess eventually causing scrotal abscess, which resolved on conservative treatment and drainage of the scrotal fecal abscess. Case Presentation. A 20-year-old male presented with gradually increasing noncolicky pain right side abdomen with nonprojectile vomiting, obstipation, and progressive abdominal distension. Clinically, the abdomen was tender with guarding over the right side with signs of inflammation on the right side back with no associated hernia. On conservative treatment, he was gradually improved but developed right side scrotal abscess a week later. CT abdomen showed a large retroperitoneal collection having multiple internal air lucencies, displacing ascending colon and caecum medically with discontinuity in the posterior wall of ascending colon. The large retroperitoneal collection was extending from right pararenal and posterior perihepatic soft tissue planes to the right iliac fossa and thigh. On drainage of the scrotal abscess, about 350 ml of fecal contents was evacuated. The patient gradually recovered and was discharged on conservative treatment with an uneventful 4-year follow-up. CONCLUSION: Diagnosis of retroperitoneal perforation of the colon is often delayed due to the absence of peritoneal irritation. An extensively large retroperitoneal abscess may spread the infection to the scrotum and thigh due to extreme pressure, possibly by dissecting away the transversalis fascia through a deep ring along the side of the spermatic cord. Timely performed CT/MRI can avoid delay in the diagnosis of retroperitoneal abscess and further spread of infection.

20.
Case Rep Gastroenterol ; 15(1): 244-252, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33790711

RESUMO

Giant biliary calculus in the common bile duct (CBD) is rare. Giant calculus of choledochal cyst (CC) is even rarer, and no case of giant calculus of CC with more than 100 calculi has been reported in the indexed literature. We present the case of a 8.0 × 4.5 × 4.0 cm sized giant calculus with >100 small calculi in type IVa CCs with heterotopic pancreas in a 45-year-old male, which is a surprisingly rare occurrence. Magnetic resonance cholangiopancreatography showed multifocal irregular dilatation of intrahepatic biliary radicles with multiple filling defects with a giant calculus in CC with cholelithiasis. The case was successfully managed with open cholecystectomy and choledochotomy with retrieval of 1 giant and more than 100 small calculi with excision of CC with Roux-en-Y hepaticojejunostomy. Histopathological examination (HPE) showed inflamed CC identified with focal areas of surface ulceration with increased fibrosis areas in the wall and few pancreatic acini. A bile duct calculus is defined as "giant" when the size is 5 cm or more. Stone formation within is the most frequent complication of CC. Most intracystic calculi have been described as soft, earthy, and pigmented in appearance, supporting bile stasis as a primary etiologic factor. The only treatment for giant calculus of CBD or CC is surgical. Endoscopic treatment is mostly unsuccessful and open surgery is the treatment of choice due to giant size, increased load of calculus, and presence of calculi in the left and right hepatic ducts.

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