Rosario Rivera

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Modern hormonal contraceptives and intrauterine contraceptive devices have multiple biologic effects. Some of them may be the primary mechanism of contraceptive action, whereas others are secondary. For combined oral contraceptives and progestin-only methods, the main mechanisms are ovulation inhibition and changes in the cervical mucus that inhibit sperm(More)
Good counseling and better selection of candidates would result in the intrauterine device's (IUD) safer use. Age and parity of the IUD acceptor do not seem to be associated with an increased risk of pelvic inflammatory disease (PID). The newer generation of copper- and hormone-releasing IUDs are associated with improved safety and efficacy.
Radiolabeled tetanus toxoid (TT) was prepared by detoxifying chromatographically purified tetanus toxin with 14C-labeled formaldehyde. 14C-TT was encapsulated inside poly (D,L-lactide-co-glycolide, 50/50) microspheres (MS) of varying average size (approximately 10 microns and approximately 50 microns). Balb/c mice were injected subcutaneously with 5 Lf(More)
Chinese women in Shanghai who delivered vaginally and who chose to use an IUD for contraception received a Copper T-380A IUD inserted vaginally within 10 minutes after delivery of the placenta (i.e., immediate postplacental insertion, IPPI). Among them, 97.7% were primipara. The women were randomly divided into two groups: IUD inserted by hand and IUD via(More)
Various methods to determine loading of vaccine in biodegradable polymer microspheres encapsulating tetanus toxoid were evaluated. The microspheres were composed of poly (D-lactic acid) (PLA) and poly (DL-lactic-co-glycolic acid) (PLGA). Dissolution of microspheres in organic solvents such as methylene chloride, chloroform, or dimethyl sulfoxide and(More)
OBJECTIVES Rotavirus is the most important etiology of severe diarrhea in Bolivia. The monovalent attenuated human oral rotavirus vaccine Rotarix(®) was introduced in Bolivia in 2008. We describe the molecular epidemiology of circulating rotavirus strains before vaccine introduction. METHODS Two thousand one hundred thirty-five diarrheal samples were(More)
Two formulations of polylactic and polyglycolic acid microcapsules containing 75 and 100 mg of NET respectively were studied for a 90-day period of anticipated contraceptive effect in two groups of five women. A 200 mg dose of NET preparation was also studied for a 180-day period of anticipated contraceptive effect in 19 women. Alteration in menstrual(More)
In May 1976 an investigation of a factory in Puerto Rico which formulates oral contraceptives revealed that during the previous 12 months five of the company's twenty-five employees (20%), and twelve of the company's thirty female employees (40%) had experienced symptoms associated with hyperestrogenism. The affected males had gynecomastia and three of them(More)
An interdisciplinary international group of researchers in the area of lactational infertility gathered with the purpose of coming to a consensus about the conditions under which breastfeeding can be used as a safe and effective method of family planning. The consensus of the group was that the maximum birth spacing effect of breastfeeding is achieved when(More)
Insertion of IUDs by trained non-physicians is increasing. This secondary analysis of TCu380A IUD acceptors collected at clinics in Nigeria, Turkey and Mexico involved 367 women; 193 insertions were performed by physicians and 174 by non-physicians. Women having their IUD inserted by a non-physician were more likely to experience a pain-free insertion, but(More)