383 research outputs found
Ricci solitons in three-dimensional paracontact geometry
We completely describe paracontact metric three-manifolds whose Reeb vector
field satisfies the Ricci soliton equation. While contact Riemannian (or
Lorentz\-ian) Ricci solitons are necessarily trivial, that is, -contact and
Einstein, the paracontact metric case allows nontrivial examples. Both
homogeneous and inhomogeneous nontrivial three-dimensional examples are
explicitly described. Finally, we correct the main result of [AGAG-D-13-00189],
concerning three-dimensional normal paracontact Ricci solitons.Comment: 16 page
Proyecto: Prolongación avenida Leopoldo Lugones ciudad de Santiago del Estero
Práctica Supervisada (IC)--FCEFN-UNC, 2013Presenta el diseño de la prolongación de Av. Lugones que se encuentra al noroeste de la ciudad de Santiago del Estero, sobre la traza de las antiguas vías del ferrocarril, vinculando en su totalidad de recorrido a Av. de Circunvalación al sur con Av. Núñez del Prado al norte. Lo principal de dicha obra es el de mejorar la travesía urbana en la dirección norte-sur de la ciudad de Santiago del Estero y por otra parte revalorizar el sector urbano en la zona de las vías férrea
Epirubicin. A new entry in the list of fetal cardiotoxic drugs? Intrauterine death of one fetus in a twin pregnancy. Case report and review of literature
BACKGROUND: Current knowledge indicate that epirubicin administration in late
pregnancy is almost devoid of any fetal cardiotoxicity. We report a twin
pregnancy complicated by breast cancer in which epirubicin administration was
causatively linked to the death of one twin who was small for gestational age
(SGA) and in a condition of oligohydramnios and determined the onset of a
transient cardiotoxicity of the surviving fetus/newborn.
CASE PRESENTATION: A 38-year-old caucasic woman with a dichorionic twin pregnancy
was referred to our center at 20 and 1/7 weeks for a suspected breast cancer,
later confirmed by the histopathology report. At 31 and 3/7 weeks, after the
second chemotherapy cycle, ultrasound examination evidenced the demise of one
twin while cardiac examination revealed a monophasic diastolic ventricular
filling, i.e. a diastolic dysfunction of the surviving fetus who was delivered
the following day due to the occurrence of grade II placental abruption. The role
of epirubicin cardiotoxicity in the death of the first twin was supported by
post-mortem cardiac and placental examination and by the absence of structural or
genomic abnormalities that may indicate an alternative etiology of fetal demise.
The occurrence of epirubicin cardiotoxicity in the surviving newborn was
confirmed by the report of high levels of troponin and transient left ventricular
septal hypokinesia.
CONCLUSION: Based on our findings we suggest that epirubicin administration in
pregnancy should be preceded by the screening of some fetal conditions like SGA
and oligohydramnios that may increase its cardiotoxicity and that, during
treatment, the diastolic function of the fetal right ventricle should be
specifically monitored by a pediatric cardiologist; also, epirubicin and
desamethasone for lung maturation should not be closely administered since
placental effects of glucocorticoids may increase epirubicin toxicity
Tricuspid valve repair and replacement for infective endocarditis
Infective endocarditis represents a challenging and life-threatening clinical condition affecting native and prosthetic heart valves, endocardium, and implanted cardiac devices. Right-sided infective endocarditis account for approximately 5–10% of all infective endocarditis and are often associated with intravenous drug use, intracardiac devices, central venous catheters, and congenital heart disease. The tricuspid valve is involved in 90% of right-side infective endocarditis. The primary treatment of tricuspid valve infective endocarditis is based on long-term intravenous antibiotics. When surgery is required, diferent interventions have been proposed, ranging from valvectomy to various types of valve repair to complete replacement of the valve. Percutaneous removal of vegetations using the AngioVac system has also been proposed in these patients. The aim of this narrative review is to provide an overview of the current surgical options and to discuss the results of the diferent surgical strategies in patients with tricuspid valve infective endocarditi
Spray-dried mucoadhesives for intravesical drug delivery using N-acetylcysteine- and glutathione-glycol chitosan conjugates
This work describes N-acetylcysteine (NAC)- and glutathione (GSH)-glycol chitosan (GC) polymer conjugates engineered as potential platform useful to formulate micro-(MP) and nano-(NP) particles via spray-drying techniques. These conjugates are mucoadhesive over the range of urine pH, 5.0-7.0, which makes them advantageous for intravesical drug delivery and treatment of local bladder diseases. NAC- and GSH-GC conjugates were generated with a synthetic approach optimizing reaction times and purification in order to minimize the oxidation of thiol groups. In this way, the resulting amount of free thiol groups immobilized per gram of NAC-and GSH-GC conjugates was 6.3 and 3.6 mmol, respectively. These polymers were completely characterized by molecular weight, surface sulfur content, solubility at different pH values, substitution and swelling degree. Mucoadhesion properties were evaluated in artificial urine by turbidimetric and zeta (zeta)-potential measurements demonstrating good mucoadhesion properties, in particular for NAC-GC at pH 5.0. Starting from the thiolated polymers, MP and NP were prepared using both the Bidchi B-191 and Nano Buchi B-90 spray dryers, respectively. The resulting two formulations were evaluated for yield, size, oxidation of thiol groups and ex-vivo mucoadhesion. The new spray drying technique provided NP of suitable size (<1 mu m) for catheter administration, low degree of oxidation, and sufficient mucoadhesion property with 9% and 18% of GSH- and NAC-GC based NP retained on pig mucosa bladder after 3 h of exposure, respectively
Fluorochrome Selection for Imaging Intraoperative Ovarian Cancer Probes
The identification and removal of all gross and microscopic tumor to render the patient disease free represents a huge challenge in ovarian cancer treatment. The presence of residual disease is an independent negative prognostic factor. Herein, we describe the synthesis and the “in vitro” evaluation of compounds as cyclooxygenase (COX)-1 inhibitors, the COX-1 isoform being an ovarian cancer biomarker, each bearing fluorochromes with different fluorescence features. Two of these compounds N-[4-(9-dimethylimino-9H-benzo[a]phenoxazin-5-ylamino) butyl]-2-(3,4-bis(4-methoxyphenyl)isoxazol-5-yl)acetamide chloride (RR11) and 3-(6-(4-(2-(3,4-bis(4-methoxyphenyl)isoxazole-5-yl)acetamido)butyl)amino-6-oxohexyl)-2-[7-(1,3-dihydro-1,1-dimethyl-3-ethyl 2H-benz[e]indolin-2-yl-idene)-1,3,5-heptatrienyl]-1,1-dimethyl-3-(6-carboxilato-hexyl)-1H-benz[e]indolium chloride, 23 (MSA14) were found to be potent and selective inhibitors of cyclooxygenase (COX)-1 “in vitro”, and thus were further investigated “in vivo”. The IC50 values were 0.032 and 0.087 µM for RR11 and 23 (MSA 14), respectively, whereas the COX-2 IC50 for RR11 is 2.4 µM while 23 (MSA14) did not inhibit COX-2 even at a 50 µM concentration. Together, this represented selectivity index = 75 and 874, respectively. Structure-based virtual screening (SBVS) performed with the Fingerprints for Ligands and Proteins (FLAP) software allowed both to differentiate highly active compounds from less active and inactive structures and to define their interactions inside the substrate-binding cavity of hCOX1. Fluorescent probes RR11 and 23 (MSA14), were used for preliminary near-infrared (NIR) fluorescent imaging (FLI) in human ovarian cancer (OVCAR-3 and SKOV-3) xenograft models. Surprisingly, a tumor-specific signal was observed for both tested fluorescent probes, even though this signal is not linked to the presence of COX-1.publishedVersio
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