The size and location of the liver abscess and the underlying comorbid diseases may affect the diagnostic sensitivity of ultrasound for pyogenic liver abscess in clinical practice. A high index of suspicion should be maintained in patients with diabetes mellitus, previous biliary tract intervention or gastrointestinal malignancy. Follow-up CT scanning is recommended if right flank knocking pain is present, even if ultrasonography is non-revealing. A diagnostic protocol for liver abscess may be feasible in the future.
Co-assembly of a cell adhesive peptide conjugate and alginate affords multifunctional composite hydrogels for rapid hemostasis and efficacious wound healing.
Flexible bioelectronics for biomedical applications requires a stretchable, conductive, self-healable, and biocompatible material that can be obtained by cost-effective chemicals and strategies. Herein, we synthesized polypyrrole or Zn-functionalized chitosan molecules, which are cross-linked with poly(vinyl alcohol) to form a hydrogel through dynamic di-diol complexations, hydrogen bonding, and zinc-based coordination bonds. These multiple dynamic interactions endow the material with excellent stretchability and autonomous selfhealing ability. The choice of Food and Drug Administration (FDA)-approved materials (poly(vinyl alcohol) and chitosan) as the matrix materials ensures the good biocompatibility of the hydrogel. The conductivity contributed by the polypyrrole allowed the hydrogel to sense strain and temperature, and the coordinated Zn significantly enhanced the antibacterial activity of the hydrogel. Moreover, using a diabetic rat model, we have proved that this hydrogel is capable of promoting the healing of the infected chronic wounds with electrical stimulation.
Recently, rapid acquisition of antibiotic resistance, increased prevalence of antibiotic-resistant bacterial infections, and slow healing of infected wound have led to vast difficulties in developing innovative antimicrobial agents to obliterate pathogenic bacteria and simultaneously accelerate wound healing. To effectively solve this problem, we designed light-responsive multifunctional nanoparticles with conjugation of quaternary ammonium chitosan and photosensitizer chlorin e6 (Ce6) to merge chemical and photodynamic therapy to efficient antibacteria. The Mg/(−)-epigallocatechin-3-gallate (EGCG) complex rapidly responded to light irradiation under 660 nm with release of magnesium ions, which effectively accelerated wound healing without toxicity to mammalian cells. Notably, positively charged nanoparticles could efficiently adhere to the bacterial surface, and reactive oxygen species (ROS) produced under laser irradiation destroyed the membrane structure of the bacteria, which is irreversible, ultimately leading to bacteria death. Thus, multifunctional nanoparticles with a combination of chemical and photodynamic antimicrobial therapy would offer guidance to rational predicted and designed new effective antimicrobial nanomaterials. Most importantly, it may represent a promising class of antimicrobial strategy for potential clinical translation.
The androgen receptor (AR) has a critical role in promoting androgen-dependent and -independent apoptosis in testicular cells. However, the molecular mechanisms that underlie the ligand-independent apoptosis, including the activity of AR in testicular stem cells, are not completely understood. In the present study, we generated induced pluripotent stem cells (iPSCs) from bovine testicular cells by electroporation of octamer-binding transcription factor 4 (OCT4). The cells were supplemented with leukemia inhibitory factor and bone morphogenetic protein 4, which maintained and stabilized the expression of stemness genes and pluripotency. The iPSCs were used to assess the apoptosis activity following exposure to phthalate esters, including di (2-ethyhexyl) phthalates, di (n-butyl) phthalate, and butyl benzyl phthalate. Phthalate esters significantly reduced the expression of AR in iPSCs and induced a higher ratio of BAX/BCL-2, thereby favoring apoptosis. Phthalate esters also increased the expression of cyclin-dependent kinase inhibitor 1 (p21Cip1) in a p53-dependent manner and enhanced the transcriptional activity of p53. The forced expression of AR and knockdown of p21Cip1 led to the rescue of the phthalate-mediated apoptosis. Overall, this study suggests that testicular iPSCs are a useful system for screening the toxicity of environmental disruptors and examining their effect on the maintenance of stemness and pluripotency, as well as for identifying the iPSC signaling pathway(s) that are deregulated by these chemicals.
Most chronic wounds suffer from infections,
and their treatment is challenging. The usage of antibiotics may lead
to bacterial resistance and adverse side effects. Positively charged
substances have shown promise, but their applications are usually
limited by certain cytotoxicity or complex synthesis. Doped polyaniline
that carries a high density of positive charges would be a promising
candidate due to its good biocompatibility and easy availability,
but its interaction with bacteria has not been elucidated. Herein,
the distinct bactericidal effect of polyaniline against Gram-positive
bacteria has been verified. The antibacterial activity may result
from the specific interaction with lipoteichoic acid to destroy the
Gram-positive bacterial cell wall. Polyaniline and a macromolecular
dopant (sulfonated hyaluronic acid) are used to construct a flexible
hydrogel with skin-mimic electrical conductivity. The in vivo results
demonstrate that electrical stimulation (ES) through this hydrogel
is superior to ES via separated electrodes (the ES strategy used clinically)
for promoting infected chronic wound healing.
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