Top of the Basilar Syndrome: A Case Report of a Healthy Young Woman and Literature Review.

Top of the basilar syndrome (TBS) is defined as the presence of multiple ischemic lesions on magnetic resonance image (MRI) including more than two territories supplied by branches of the distal portion of the basilar artery, causing symptoms such as dizziness, diplopia, ataxia, and acute cognitive decline that can lead to quadriplegia and death. Diagnosing TBS is challenging because it can mimic other conditions such as thalamic hemorrhages or vertebrobasilar ischemia, and requires advanced imaging. Although the prognosis for these patients is poor, rehabilitation is essential for their recovery. This case describes a healthy 28-year-old woman who presented with headache, vomiting, and tonic-clonic seizures sent to the hospital with a stroke diagnosis.

Antimicrobial Resistance Trends at a Pediatric Hospital in Guatemala City, 2005-2019.

Antimicrobial resistance (AMR) is increasing worldwide. We analyzed AMR rates for bacterial species identified from pediatric blood cultures between 2005 and 2019 at a single institution in Guatemala. We found significantly increased rates in Gram-negative resistance, with a high prevalence of carbapenem-resistant Acinetobacter and Klebsiella harboring the New Delhi metallo-beta-lactamase gene.

Bacterial killing by light-triggered release of silver from biomimetic metal nanorods.

Illumination of noble metal nanoparticles at the plasmon resonance causes substantial heat generation, and the transient and highly localized temperature increases that result from this energy conversion can be exploited for photothermal therapy by plasmonically heating gold nanorods (NRs) bound to cell surfaces. Here, plasmonic heating is used for the first time to locally release silver from gold core/silver shell (Au@Ag) NRs targeted to bacterial cell walls. A novel biomimetic method of preparing Au@Ag core-shell NRs is employed, involving deposition of a thin organic polydopamine (PD) primer onto Au NR surfaces, followed by spontaneous electroless silver metallization, and conjugation of antibacterial antibodies and passivating polymers for targeting to gram-negative and gram-positive bacteria. Dramatic cytotoxicity of S. epidermidis and E. coli cells targeted with Au@Ag NRs is observed upon exposure to light as a result of the combined antibacterial effects of plasmonic heating and silver release. The antibacterial effect is much greater than with either plasmonic heating or silver alone, implying a strong therapeutic synergy between cell-targeted plasmonic heating and the associated silver release upon irradiation. The findings suggest a potential antibacterial use of Au@Ag NRs when coupled with light irradiation, which has not been previously described.

Polydopamine-enabled surface functionalization of gold nanorods for cancer cell-targeted imaging and photothermal therapy.

AIM: A novel biomimetic strategy was employed for presenting antibodies on gold nanorods (NRs) to target growth factor receptors on cancer cells for use in photothermal therapy. MATERIALS & METHODS: Polydopamine (PD) was polymerized onto gold NRs, and EGF receptor antibodies (anti-EGFR) were immobilized onto the layer. Cell-binding affinity and light-activated cell death of cancer cells incubated with anti-EGFR-PD-NRs were quantified by optical imaging. RESULTS: PD was deposited onto gold NRs, and antibodies were bound to PD-coated NRs. Anti-EGFR-PD-NRs were stable in media, and were specifically bound to EGFR-overexpressing cells. Illumination of cells targeted with anti-EGFR-PD-NRs enhanced cell death compared with nonirradiated controls and cells treated with antibody-free NRs. CONCLUSION: PD facilitates the surface functionalization of gold NRs with biomolecules, allowing cell targeting and photothermal killing of cancer cells. PD can potentially coat a large variety of nanoparticles with targeting ligands as a strategy for biofunctionalization of diagnostic and therapeutic nanoparticles.

Polydopamine-assisted immobilization of trypsin onto monolithic structures for protein digestion.

Inspired by the catechol-rich adhesive proteins of the mussel foot, we report a simple and versatile aqueous approach for the immobilization of trypsin onto silica and titania monolithic supports. The method involves in-situ coating of the monolithic substrates with a catechol-containing biomimetic polymer (polydopamine) derived from the polymerization of dopamine under alkaline pH, followed by conjugation of trypsin to the polydopamine polymer coating. The trypsin immobilization efficiency onto the monolithic materials was investigated as a function of different preparation parameters such as dopamine concentration and coating time. The enzymatic activity of the immobilized trypsin reactors was evaluated, and mass spectrometry based proteomic analysis was demonstrated by digestion of a model protein. The method presented in this manuscript has broad potential for immobilization of trypsin and other enzymes onto a wide variety of monolithic supports, due to the ability of polydopamine to act as a primer for covalent immobilization of proteins.

Mussel-inspired silver-releasing antibacterial hydrogels.

A silver-releasing antibacterial hydrogel was developed that simultaneously allowed for silver nanoparticle formation and gel curing. Water-soluble polyethylene glycol (PEG) polymers were synthesized that contain reactive catechol moieties, inspired by mussel adhesive proteins, where the catechol containing amino acid 3,4-dihydroxyphenylalanine (DOPA) plays an important role in the ability of the mussel to adhere to almost any surface in an aqueous environment. We utilized silver nitrate to oxidize polymer catechols, leading to covalent cross-linking and hydrogel formation with simultaneous reduction of Ag(I). Silver release was sustained for periods of at least two weeks in PBS solution. Hydrogels were found to inhibit bacterial growth, consistent with the well-known antibacterial properties of silver, while not significantly affecting mammalian cell viability. In addition, thin hydrogel films were found to resist bacterial and mammalian cell attachment, consistent with the antifouling properties of PEG. We believe these materials have a strong potential for antibacterial biomaterial coatings and tissue adhesives, due to the material-independent adhesive properties of catechols.

Facile, high efficiency immobilization of lipase enzyme on magnetic iron oxide nanoparticles via a biomimetic coating.

BACKGROUND: Immobilization of lipase on appropriate solid supports is one way to improve their stability and activity, and can be reused for large scale applications. A sample, cost- effective and high loading capacity method is still challenging. RESULTS: A facile method of lipase immobilization was developed in this study, by the use of polydopamine coated magnetic nanoparticles (PD-MNPs). Under optimal conditions, 73.9% of the available lipase was immobilized on PD-MNPs, yielding a lipase loading capacity as high as 429 mg/g. Enzyme assays revealed that lipase immobilized on PD-MNPs displayed enhanced pH and thermal stability compared to free lipase. Furthermore, lipase immobilized on PD-MNPs was easily isolated from the reaction medium by magnetic separation and retained more than 70% of initial activity after 21 repeated cycles of enzyme reaction followed by magnetic separation. CONCLUSIONS: Immobilization of enzyme onto magnetic iron oxide nanoparticles via poly-dopamine film is economical, facile and efficient.

pH responsive self-healing hydrogels formed by boronate-catechol complexation.

Here we report the synthesis and characterization of pH-responsive, self-healing hydrogels based on boronate-catechol complexation.

Enrichment/isolation of phosphorylated peptides on hafnium oxide prior to mass spectrometric analysis.

Hafnium oxide (hafnia) exhibits unique enrichment properties towards phosphorylated peptides that are complementary to those of titanium oxide (titania) and zirconium oxide (zirconia) for use with mass spectrometric analysis in the field of proteomics.

Delayed thrombolysis in a patient presenting after 12 hours of chest pain, cardiogenic shock and life-threatening arrhythmias.

This 63 years old man presented to the emergency room with chest pain of more than 12 hours duration. The initial electrocardiogram showed as ST segment elevation inferior and right ventricular infarction. He developed signs and symptoms consistent with cardiogenic shock, followed by life threatening ventricular fibrillation and cardiac arrest. After repeated cardio-respiratory resuscitations and successful cardiac defibrillation, thrombolytic therapy was administered followed by clinical and hemodynamic improvements. One-week later cardiac catheterization and coronary arteriography were performed. The study showed 93% obstructive lesion in the proximal right coronary artery, an angioplasty was performed and a stent was placed. After appropriate re-adjustment of medical therapy, the patient was discharged and followed in the outpatient clinic. Although the time frame to administer thrombolytic therapy was over the 12 hours window as suggested by the AHA guidelines1, the potential risks benefits in the casepresented justifed the used of fibrinolytic therapy. Considering the multiple complications that the patient presented, fibrinolytic therapy needs to be considered even after 12 hours of symptoms initiation, particularly when facilities for primary percutaneous coronary interventions are not readily available.

Metal oxide monolithic columns.

Metal oxide monoliths composed of ZrO2 and HfO2 have been synthesized in situ inside capillary columns. The material shows globular-like structure and through pores. Capillary electrochromatography and capillary liquid chromatography were performed in a monolithic column with the HfO2 material. Separation of a simple sample mixture showed the potential of the new metal oxide monolithic columns.

Allyl-functionalized hybrid silica monoliths.

A hybrid organosilica monolith was synthesized containing an allyl functionality. This provided a viable platform for producing silica-based, chromatographic, monolithic columns with the stationary phase bonded through a surface silicon-carbon bond rather than a conventional siloxane bond.

La enteritis por campylobacter fetus / Enteritis by Campylobacter fetus

El Campylobacter jejuni ha sido reconocido recientemente como un patógeno importante en los humanos, y si se utilizan los medios de cultivo apropiados, probablemente se recobra de pacientes con diarreas agudas con la misma frecuencia que se recobran Salmonella o Shigella. Este organismo es responsable no sólo de cuadros de enteritis y diarreas agudas, sino que ha sido asociado a eritema nodoso, endocarditis, meningitis, abortos y proctitis entre otras enfermedades. Usualmente, el curso es autolimitado, recuperándose el paciente en menos de una semana. Sin embargo, en aquellos pacientes con diarreas prolongadas o cuadros de enteritis recurrentes, se recomienda tratamiento con eritromicina por vía oral. Los medios de cultivos simplificados y prácticos nos permiten hacer el diagnóstico de enteritis por campylobacter, por lo que debemos considerar este organismo y ordenarlo en las muestras de rutina en el paciente que se presenta con diarreas agudas