Reticencia vacunal: análisis del discurso de madres y padres con rechazo total o parcial a las vacunas

Objective

To analyse and understand vaccination hesitancy discourses, particularly those of people who have decided not to vaccinate their sons and daughters.

Nitrate administration to enhance the detection of myocardial viability by technetium-99m tetrofosmin single-photon emission tomography

A comparison was performed between technetium-99m tetrofosmin myocardial perfusion tomography at baseline and after nitrate administration, using a 2-day protocol, and rest-reinjection thallium-201 single-photon emission tomography (SPET) studies in order to assess whether nitrates enhance the detection of viable myocardium with^99mTc-tetrofosmin. Fifteen patients with coronary artery disease, previous myocardial infarction and a left ventricular ejection fraction <40% underwent²⁰¹T1 rest-injection and^99mTc-tetrofosmin. baseline-postnitroglycerin (0.4 mg sublingually) SPET studies, within 48 h. Tomograms based on the three spatial planes were divided into 15 segments and regional tracer uptake was quantitatively analysed. Viability was defined as presence of tracer uptake >50% of peak activity on baseline studies or after reversibility. The percentage of peak activity of^99mTc-tetrofosmin at baseline correlated with that of 201T1 (r=0.82,P <0.001). On baseline^99mTc-tetrofosmin studies, 73 of the 225 segments that were analysed had <50% of peal. activity. Fifteen percent of these segments showed reversibility after nitrate administration, with an increase in^99mTc-tetrofosmin uptake from 40%±9% to 57%±9% of peak activity (P=0.003). All reversible segments after nitrate administration had viability criteria on²⁰¹Tl studies, but 20 segments that were non-viable on^99mTc-tetrofosmin. studies were viable on²⁰¹Tl studies. Using a threshold value of >40% of peak activity, only seven segments remained non-viable on^99mTc-tetrofosmin studies. Overall agreement between^99mTc-tetrofosmin with nitrates and²⁰¹Tl-reinjection regarding the presence of myocardial viability was 90%. Detection of myocardial viability with^99mTc-tetrofosmin. was enhanced after nitrate administration, correlating with viability criteria observed on thallium studies.     

Solid-phase radioimmunoassay in antibody-coated tubes for the quantitative determination of tetanus antibodies

A technique using antibody-coated tubes allows the radioimmunological determination of tetanus antibodies in a simple and rapid way. The procedure is based on the competition for¹²⁵I-tetanus toxin between the insolubilized antibodies and the antibodies present in the unknown sample. When antibodies and¹²⁵I labeled tetanus toxin are incubated in the antibody-coated polyethylene vessel the detection limit is about 0.016 IU/ml. When tetanus toxin is preincubated together with its antibody in uncoated vessels before the mixture is transferred to antibody-coated vessels, the sensitivity can be raised about tenfold. The method is especially useful for screening multiple samples.     

Interest in genetic testing among first-degree relatives of breast cancer patients

The recent cloning of a breast-ovarian cancer susceptibility gene (BRCA1), and determination of the locus of a related gene (BRCA2), offers potential for clinical genetic testing for breast cancer susceptibility. This study examined interest in and expectations about an impending genetic test among first-degree relatives (FDRs) of breast cancer patients. One hundred five females completed two structured telephone interviews to assess demographics, breast cancer risk factors, psychological factors, and attitudes about genetic testing for breast cancer susceptibility. Overall, 91% of FDRs said that they would want to be tested, 4% said they would not, and 5% were uncertain. The most commonly cited reasons for wanting genetic testing were to learn about one's children's risk, to increase use of cancer screening tests, and to take better care of oneself. Women with less formal education were motivated by childbearing decisions and future planning to a greater degree than were women with education beyond high school. Most women anticipated a negative psychological impact of positive test results, involving increased anxiety (83%), depression (80%), and impaired quality of life (46%). In addition, 72% of women indicated that they would still worry if they tested negative. In multivariate regression analysis, level of baseline depression was the strongest predictor of an anticipated negative impact of genetic testing (Beta =.15; P,.0001). These results suggest that the demand for genetic testing for breast cancer susceptibility may be great, even among women who are not likely to have predisposing mutations. Prior to widespread availability of such testing, it will be critical to develop informed consent protocols to educate individuals about the benefits and limitations of predictive testing for this multifactorial disease. © 1995 Wiley-Liss, Inc.     

Monozygotic twinning after assisted reproductive techniques: a phenomenon independent of micromanipulation

A 3 year retrospective analysis was conducted of pregnancies achieved after various assisted reproductive treatment modalities in our infertility practice, to calculate and compare the rates of monozygotic twinning (MZT). A total of 731 pregnancies achieved after various assisted reproduction treatments were reviewed. Gonadotrophin therapy for induction of ovulation and controlled ovarian hyperstimulation (COH) yielded 129 clinical pregnancies. Conventional IVF yielded 139 pregnancies. IVF and intracytoplasmic sperm injection (ICSI) with or without assisted hatching (AH) yielded 463 pregnancies, all during the same time period. The rates of multiple pregnancy (monozygotic and dizygotic) twins and triplets were recorded. MZT was found in 1.5% of ovulation induction or COH pregnancies (2/129). The incidence of MZT after conventional IVF was 0.72% (1/139). After IVF-ICSI/AH, MZT was found in 0.86% (4/463). The overall rate of MZT was 0.95% (7/731). Five cases were dizygotic triplets and two cases were monozygotic twins. We found the rate of MZT after assisted reproduction treatment increased more than two-fold over the background rate in the general population. Dizygotic triplets were found more often than monozygotic twins. The rate of MZT was consistently increased, irrespective of treatment modality or micromanipulation. This may signify that the aetiology of increased MZT after assisted reproduction is the gonadotrophin treatment rather than in-vitro conditions, micromanipulation, or multiple embryo transfer.     

Polyclonal 111In-IgG, 125I-LDL and 125I-endothelin-1 accumulation in experimental arterial wall injury

To test iodine-125 labelled low-density lipoprotein (¹²⁵I-LDL), polyclonal indium-111 labelled immunoglobulin G (¹¹¹In-IgG) and iodine-125 labelled endothelin-1 uptake in metabolically active atheromatous plaques after arterial wall injury, we performed balloon de-endothelialization of carotid arteries or abdominal aortas in 24 New Zealand male rabbits which were fed with a normal diet (n=14) or a hypercholesterolaemic diet (n=10) after surgery. Six weeks later the animals were injected with 200 Ci of (¹²⁵I-LDL), and/or with 100 Ci of ¹¹¹In-IgG or with 9 Ci of ¹²⁵I-endothelin-1. Forty-eight hours later the animals were sacrificed. Carotid arteries and aortas were removed, counted and fixed for autoradiography and light microscopy examination. Contralateral carotid arteries and thoracic aortas served as controls.Significant ¹¹¹In-IgG uptake was observed in the injured arteries at autoradiography, with localization mainly in the healing edges, and at well counting. The percentage of the injected dose per gram (%D.inj/g) was 0.0188±0.06 versus 0.0059±0.003 in controls (P< 0.05). There was no difference in ¹¹¹In-IgG uptake between arteries with injury alone and those with active atheroma formation at the site of the injury. Significant (¹²⁵I-LDL), uptake was observed only when lipid deposition was present at light microscopy (%D.inj/g of 0.0024±0.0005 vs 0.0010±0.0003 in controls, P < 0.05). ¹²⁵I-endothelin-1 accumulation was observed in four of five injured aortas both at autoradiography, with diffuse localization, and at well counting (%D.inj/g of 0.0012±0.0004 in the abdominal aortas vs 0.0008±0.0003 in the thoracic aortas).Polyclonal IgG may accumulate in injured arteries without active atheroma formation. Inflammatory reaction at the site of the injury may cause ¹¹¹In-IgG uptake independently of atheromatous plaque formation. LDL accumulation takes place only with active atheroma formation at the site of the injury. Use of labelled peptides such as endothelin-1 may provide further insight into the mechanisms of atheromatous plaque formation.     

Diarrheal deaths in the United States, 1979 through 1987. A special problem for the elderly

OBJECTIVE.--Diarrhea is an important cause of death among young children in both developing and developed countries, but little is known about diarrheal death among adults. In this study, we examined trends in diarrheal deaths among all age groups in the United States. DESIGN/SETTING/PARTICIPANTS.--We reviewed national mortality data complied by the National Center for Health Statistics, Hyattsville, Md, which consists of information from all death certificates filed in the United States for the period 1979 through 1987. A death for which diarrhea was listed as an immediate or underlying cause was considered a "diarrheal death" and included in the analysis. RESULTS.--We found that 28,538 persons died of diarrhea cited as either an immediate or the underlying cause of death during the 9-year period. A majority of diarrheal deaths occurred among the elderly (older than 74 years of age, 51%), followed by adults 55 to 74 years of age (27%), and young children (younger than 5 years of age, 11%). For the elderly, adjusted risk factors for dying of diarrhea included being white, female, and residing in a long-term care facility. Only the elderly and young children had clear, distinct winter peaks of diarrheal deaths, suggesting that the diarrhea may, in part, be infectious in origin. CONCLUSION.--For the elderly, more directed studies of those at risk, such as nursing home residents, are needed to determine if oral rehydration therapy, vaccines, or other preventive measures might benefit this population.     

Smoking Cessation Pharmacogenetics: Analysis of Varenicline and Bupropion in Placebo-Controlled Clinical Trials

Despite effective therapies for smoking cessation, most smokers find quitting difficult and most successful quitters relapse. Considerable evidence supports a genetic risk for nicotine dependence; however, less is known about the pharmacogenetics of smoking cessation. In the first pharmacogenetic investigation of the efficacy of varenicline and bupropion, we examined whether genes important in the pharmacodynamics and pharmacokinetics of these drugs and nicotine predict medication efficacy and adverse events. Subjects participated in randomized, double-blind, placebo-controlled smoking cessation clinical trials, comparing varenicline, a nicotinic acetylcholine receptor (nAChR) partial agonist, with bupropion, a norepinephrine/dopamine reuptake inhibitor, and placebo. Primary analysis included 1175 smokers of European ancestry, and 785 single nucleotide polymorphisms from 24 genes, representing 254 linkage disequilibrium (LD) bins (genes included nAChR subunits, additional varenicline-specific genes, and genes involved in nicotine or bupropion metabolism). For varenicline, continuous abstinence (weeks 9–12) was associated with multiple nAChR subunit genes (including CHRNB2, CHRNA5, and CHRNA4) (OR=1.76; 95% CI: 1.23–2.52) (p<0.005); for bupropion, abstinence was associated with CYP2B6 (OR=1.78; 95% CI: 1.27–2.50) (p<0.001). Incidence of nausea was associated with several nAChR subunit genes (OR=0.50; 95% CI: 0.36–0.70) (p<0.0001) and time to relapse after quitting was associated with HTR3B (HR=1.97; 95% CI: 1.45–2.68) (p<0.0001). These data provide evidence for multiple genetic loci contributing to smoking cessation and therapeutic response. Different loci are associated with varenicline vs bupropion response, suggesting that additional research may identify clinically useful markers to guide treatment decisions.