Natural immunity to measles, rubella and mumps among Spanish children in the pre-vaccination era

Prior to the start of mass vaccination campaigns against measles, rubella and mumps, a prevalence study of natural immunity to these diseases was undertaken in a sample of 1700 unvaccinated Spanish children. They were representative of the 3-7 year-old population in terms of age, regional distribution and urban or rural environment. Measles infection prevalence was significantly higher than that for rubella and mumps from 3 (48.3%, 14.2%, 25.5%, respectively) through 7 years of age, (64%, 40.9%, 39%). As a function of age, naturally-acquired immunity increased according to parabolic progressions. In the 3-5 year-old group, rural environment, low socioeconomic status, no school attendance and lack of brothers were associated with statistically lower levels of measles, rubella, or mumps infection. In the 6-7 year-old group, only 12% of the children showed antibodies against the three diseases and 18.7% exhibited triple susceptibility.

Vaccination against hepatitis B in renal dialysis units: short or normal vaccination schedule?

Three I.M. injections of hepatitis B vaccine (Merck Sharp & Dohme) were administered, according to the recommended schedule (0, 1, 6 mos), to seronegative individuals of one renal dialysis unit (33 patients, 58 health care personnel) and, according to a shorter regimen (0, 1, 3 mos), in another unit of similar characteristics (30 patients, 53 health care personnel). Staff members and renal patients received, respectively, 20 y 40 mcg of vaccine per injection. In the early vaccination phase, the two regimens did not lead to a difference in seroconversion rates nor in anti-HBs titers. After a 9-month surveillance, lower seroconversion rates, although not significant, were observed with the accelerated regimen among staff members (84.2%) and renal patients (79.2%) as compared with 93% and 87.5%, respectively, following the normal schedule. At the same time, anti-HBs titers were significantly lower (p less than 0.001) in the staff (316 RIA U) and patients (93 U) vaccinated according to the short regimen than in their respective counterparts (4196 and 1047 U) assigned to the normal schedule. A fourth dose of vaccine given to subjects with low and no anti-HBs titers significantly increased seroconversion and anti-HBs levels, although with little success among the former non-responders.

Hepatitis B virus infection and vaccination in children undergoing hemodialysis

Among 54 patients, between 2 and 18 years of age, submitted to hemodialysis due to severe chronic renal failure, the prevalence of hepatitis B virus markers was 66.7% and that of HBsAg was 13.0%. Eighteen children, with no evidence of hepatitis B virus infection, were vaccinated. Following three vaccine injections, only 2 patients did not respond and a third one developed low anti-HBs titers. The vaccine was well tolerated. No relationship was observed between the intensity of the humoral immune response and age, sex, type of renal disease and time on dialysis. Seroconversion rates (87.5%) and geometric means of anti-HBs titers (greater than 4 000 Ausab Units) of these patients are similar to those observed following vaccination of healthy adults.

A study on the Valsalva manoeuvre in young healthy subjects

The Valsalva manoeuvre was performed by 2 groups of young healthy male subjects: novice divers and professional divers. The electrophysiological features of this manoeuvre are summarized and the results of the test are correlated with subject age, motivation and FEV1/VC coefficient (forced expiratory volume sec/vital capacity). Positive test results (fainting caused by the Valsalva manoeuvre) increased with subject motivation (novice divers), FEV1/VC coefficient and decreasing subject age. The various hypotheses proposed to account for fainting caused by the Valsalva manoeuvre are discussed with respect to these data. The implications of Valsalva positivity in young divers are discussed.

The ascending slope of the apexcardiogram. Its relationship with angiographic determination of left ventricular function

The relationship between the ascending slope of the apexcardiogram (ACG) and direct determination of left ventricular (LV) performance as assessed angiographically by measurement of the ejection fraction (EF), mean velocity of circumferential fiber shortening (mVcF), mean normalized systolic ejection rate (MNSER), and percentage of the systolic shortening of ventricular long axis (%L), were studied in 40 patients with a wide variety of cardiac diseases. The ascending slope correlated closely and significantly (P less than 0.05) with all of them: (1) EF (r = 0.774), (2) mVcF (r = 0.776), (3) MNSER (r = 0.767) and (4) %L (r = 0.668). In a control group of 10 normal subjects, phi was determined and compared with that obtained in patients with depressed LV function, the difference being statistically significant (P less than 0.01). Other noninvasive indices derived from simultaneous phono-mechano-cardiographic readings were also studied. The calibrated ACG did not correlate with any of the hemodynamic indices; however the calibrated carotidogram did correlate with the peak systolic aortic pressure (r = 0.503). The ratio preejection period/left ventricular ejection time correlated significantly, but less than previously reported with the EF (r = 0.574). We conclude that the value of phi leads to additional evidence supporting the use of quantitative ACG as a noninvasive measure of LV performance in patients with cardiac disease.

Hemodynamic and angiocardiographic changes following nitroglycerin in coronary artery disease

33 patients with suspected coronary artery disease were studied hemodynamically and angiocardiographically in the resting state and following administration of 0.4 mg of sublingual nitroglycerin (NTG). After NTG several parameters were changed: LVEDP, mean LV systolic pressure, EDVI, ESVI, SVI and SWI were decreased; EF, mean Vcf, MNSER, heart rate (P less than 0.01; r = 0.801) and chords, hemichords and shortening of long axis were increased. However, the changes after NTG were markedly different in patients with diffuse and localized LV asynergy, suggesting a more important inotropic effect of NTG in patients with localized LV asynergy, while reduction in venous return and EDV would be the main effect of NTG in patients with diffuse LV asynergy.