RESUMEN
A 24-year-old woman had chronic uterine inversion after failed manual reversion of acute uterine inversion following a full-term vaginal delivery. After 2 failed attempts at manual reversion under general anesthesia, operative laparoscopy was performed. After infiltration of the pubovesicocervical fascia with dilute adrenaline in saline solution and division of the uterovesical fold, the anterior cervix and uterus were incised vertically, the inversion corrected, and the incision closed in 2 layers with 1-0 polyglactin 910 interrupted sutures. Postoperatively, estradiol valerate was administered for 30 days. Repeat endoscopy 4 months later revealed a normal uterine cavity. Adhesions between the anterior uterine wall and the anterior abdominal wall were divided, and chromopertubation revealed bilaterally patent fallopian tubes bilaterally.
Asunto(s)
Trastornos Puerperales/cirugía , Inversión Uterina/cirugía , Adulto , Enfermedad Crónica , Femenino , Humanos , Histeroscopía , LaparoscopíaRESUMEN
To develop targeted pharmaceutical carriers additionally capable of responding to certain local stimuli, such as decreased pH values in tumors or infarcts, targeted long-circulating PEGylated liposomes and PEG-phosphatidylethanolamine (PEG-PE)-based micelles have been prepared with several functions. First, they are capable of targeting a specific cell or organ by attaching the monoclonal antimyosin antibody 2G4 to their surface via pNP-PEG-PE moieties. Second, these liposomes and micelles were additionally modified with biotin or TAT peptide (TATp) moieties attached to the surface of the nanocarrier by using biotin-PE or TATp-PE or TATp-short PEG-PE derivatives. PEG-PE used for liposome surface modification or for micelle preparation was made degradable by inserting the pH-sensitive hydrazone bond between PEG and PE (PEG-Hz-PE). Under normal pH values, biotin and TATp functions on the surface of nanocarriers were "shielded" by long protecting PEG chains (pH-degradable PEG(2000)-PE or PEG(5000)-PE) or by even longer pNP-PEG-PE moieties used to attach antibodies to the nanocarrier (non-pH-degradable PEG(3400)-PE or PEG(5000)-PE). At pH 7.4-8.0, both liposomes and micelles demonstrated high specific binding with 2G4 antibody substrate, myosin, but very limited binding on an avidin column (biotin-containing nanocarriers) or internalization by NIH/3T3 or U-87 cells (TATp-containing nanocarriers). However, upon brief incubation (15-30 min) at lower pH values (pH 5.0-6.0), nanocarriers lost their protective PEG shell because of acidic hydrolysis of PEG-Hz-PE and acquired the ability to become strongly retained on an avidin column (biotin-containing nanocarriers) or effectively internalized by cells via TATp moieties (TATp-containing nanocarriers). We consider this result as the first step in the development of multifunctional stimuli-sensitive pharmaceutical nanocarriers.
Asunto(s)
Portadores de Fármacos , Sistemas de Liberación de Medicamentos , Concentración de Iones de Hidrógeno , Nanopartículas , Ensayo de Inmunoadsorción Enzimática , Liposomas , Espectroscopía de Resonancia Magnética , Micelas , Fosfatidiletanolaminas/química , Polietilenglicoles/químicaRESUMEN
Literature survey revealed a wide variation in the measured stability constant values of the aqueous fluoride complexes of trivalent cerium. This could be due to inadequate care for full conversion and maintenance of the oxidation state of cerium to trivalent state. In the present work quinhydrone has been used to ensure complete absence of Ce(IV) and the stability constant of CeF(2+) in 1 M NaClO(4) has been measured potentiometrically using a fluoride ion selective electrode. Log beta(1) obtained in this work was 2.936+/-0.024 and fitted well with the general trend of stability constants of the lanthanide (rare earths) fluorides in aqueous solution.
RESUMEN
The stability constants of the fluoride complexes of cerium(IV) in 1 M (HClO(4), NaClO(4)) medium have been measured potentiometrically using a fluoride ion-selective electrode. Quantitative oxidation of cerium to its tetravalent state and its stabilisation in the perchlorate medium were accomplished by oxidation with AgO followed by quick addition of a known amount of fluoride ion. This procedure ensures stability of the oxidation state and prevents hydrolysis and polymerisation of Ce(IV). Logarithms of the average values of beta(1), beta(2), beta(3) and beta(4) were estimated to be 7.57+/-0.04, 14.50+/-0.03, 20.13+/-0.37 and 24.14+/-0.10 respectively.