Spontaneous corneal melting in pregnancy: a case report

<p>Abstract</p> <p>Background</p> <p>To report a case of spontaneous corneal melting in pregnancy. We reviewed the literature on corneal melting and the effect of pregnancy on cornea and collagen containing tissues.</p> <p>Case presentation</p> <p>A 29-year-old woman who underwent radial keratotomy in both eyes followed by trabeculectomy in her left eye developed corneal melting in the same eye, in her seventh month of pregnancy. Despite screening, no infectious or immune mediated condition could be identified. She was managed conservatively with cyanoacrylate glue, bandage contact lens, lubricants and antibiotics.</p> <p>Conclusion</p> <p>It may not always be possible to find the underlying cause of corneal melting but the more common underlying causes should be ruled out by proper investigations. Pregnancy with its host of hormonal changes could potentially have some effect on corneal collagen leading to corneal melting in compromised corneas.</p

Nitrogen-Doped Arginine Carbon Dots and Its Metal Nanoparticle Composites as Antibacterial Agent

Nitrogen (N)-doped arginine carbon dots (Arg CD) were successfully synthesized using arginine as the amine source and citric acid as the carbon source via a one-pot green synthesis microwave-assisted technique in 2 min. Ag and Cu nanoparticles (NP) were generated within N-doped Arg CDs as composite Arg-Ag CDs and Arg-Cu CDs to render enhanced antibacterial properties. TEM analysis revealed that Arg CDs are in graphitic structures with d spacing ranging from 0.5 nm to 10 nm. The minimum inhibition concentration (MIC) values of Arg CDs with 6.250 mg/mL were decreased by about 100-fold for Arg-Ag CDs and ten-fold for Arg-Cu CDs with 0.062 and 0.625 mg/mL MIC values against Staphylococcus aureus (S. aureus). The highest antibacterial susceptibility was observed for the Arg-Ag CD composite with 0.125 and 0.312 mg/mL minimum bactericidal concentration (MBC) values against Gram negative S. aureus and Gram positive Escherichia coli (E. coli) bacteria strains, respectively. It was found that the metal NPs within Arg CDs significantly increased the antibacterial properties of CDs making them available in the treatment of infections caused by different bacterial species. Furthermore, Arg-Ag CD and Arg-Cu CD composites were tested for Acetylcholinesterase (AChE, E.C. 3.1.1.7) that break down acetylcholine (ACh) into choline and acetic acid leading to the loss of ACh which plays an essential role as neurotransmitter in Alzheimer disease. It was found that Arg-Cu CDs inhibited 74.9 &plusmn; 0.8% and Arg-Ag CDs inhibited 52.1 &plusmn; 3.8% of AChE at a 1.82 mg/mL concentration versus no inhibition for Arg-CD. Moreover, the chelating activity of Arg-Cu CDs and Arg-Ag CDs were tested for Fe(II) and it was found that almost 100% chelating was attained at 116 &mu;g composites versus no measurable chelation for bare Arg CDs, suggesting the potential neurodegenerative disease treatment properties of these composite CDs in the brain

Cryogel composites based on hyaluronic acid and halloysite nanotubes as scaffold for tissue engineering

© 2019 Elsevier B.V. We present here preparation of mechanically strong and biocompatible cryogel composites based on hyaluronic acid (HA) and halloysite nanotubes (HNTs) of various compositions, and their applications as scaffold for different cell growing media. Uniaxial compression tests reveal that the incorporation of HNTs into HA cryogels leads to a ~2.5-fold increase in their Young moduli, e.g., from 38 ± 1 to 99 ± 4 kPa at a HA:HNTs weight ratio of 1:2. Although HA:HNTs based cryogels were found to be blood compatible with 1.37 ± 0.11% hemolysis ratio at a HA:HNTs weight ratio of 1:2, they trigger thrombogenic activity with a blood clotting index of 17.3 ± 4.8. Remarkably, HA:HNTs cryogel composites were found to be excellent scaffold materials in the proliferation of rat mesenchymal stem cells (MSC), human cervical carcinoma cells (HeLa), and human colon cancer cells (HCT116). The cell studies revealed that an increased amount of HNT embedding into HA cryogels leads to an increase of MSC proliferation

Appendiceal polyp as a lead point for an appendico-colic intussusception requiring operative reduction

Intussusception of the appendix is a rare condition. When intussusception occurs in the pediatric age group, the intussusceptum usually involves the ileum, cecum or colon. The majority of cases of pediatric intussusception are idiopathic, without a pathologic lead point, and polyps are an uncommon focus of invagination. In this case report, we describe a three year-old female with known Juvenile Polyposis Syndrome (JPS) who presented to our Emergency Department with an appendico-colic intussusception in the right lower quadrant, extending to the right upper quadrant of the abdomen. The patient underwent a surgical reduction of the intussusception and an appendiceal polyp was noted to be the pathologic lead point. The case highlights a highly unusual presentation of intussusception and the surgical management utilized