Hemodynamic responses during and after multiple sets of stretching exercises performed with and without the Valsalva maneuver

OBJECTIVE:

This study investigated the acute hemodynamic responses to multiple sets of passive stretching exercises performed with and without the Valsalva maneuver.

METHODS:

Fifteen healthy men aged 21 to 29 years with poor flexibility performed stretching protocols comprising 10 sets of maximal passive unilateral hip flexion, sustained for 30 seconds with equal intervals between sets. Protocols without and with the Valsalva maneuver were applied in a random counterbalanced order, separated by 48-hour intervals. Hemodynamic responses were measured by photoplethysmography pre-exercise, during the stretching sets, and post-exercise.

RESULTS:

The effects of stretching sets on systolic and diastolic blood pressure were cumulative until the fourth set in protocols performed with and without the Valsalva maneuver. The heart rate and rate pressure product increased in both protocols, but no additive effect was observed due to the number of sets. Hemodynamic responses were always higher when stretching was performed with the Valsalva maneuver, causing an additional elevation in the rate pressure product.

CONCLUSIONS:

Multiple sets of unilateral hip flexion stretching significantly increased blood pressure, heart rate, and rate pressure product values. A cumulative effect of the number of sets occurred only for systolic and diastolic blood pressure, at least in the initial sets of the stretching protocols. The performance of the Valsalva maneuver intensified all hemodynamic responses, which resulted in significant increases in cardiac work during stretching exercises.     

Transient neonatal diabetes due to a missense mutation (E227K) in the gene encoding the ATP‐sensitive potassium channel (KCNJ11)

Neonatal diabetes is a monogenic form of diabetes. Herein, we report on a newborn presenting diabetic ketoacidosis at 17 days of life . A KCNJ11 mutation was identified. In such cases, insulin can be replaced by sulfonylurea with a successful metabolic control, as an example of how molecular diagnosis may influence the clinical management of the disorder.     

Overview of the biochemical and genetic processes in malignant mesothelioma

Malignant mesothelioma (MM) is a highly aggressive form of cancer, has a long latency period, and is resistant to chemotherapy. It is extremely fatal, with a mean survival of less than one year. The development of MM is strongly correlated with exposure to asbestos and erionite, as well as to simian virus 40. Although various countries have banned the use of asbestos, MM has proven to be difficult to control and there appears to be a trend toward an increase in its incidence in the years to come. In Brazil, MM has not been widely studied from a genetic or biochemical standpoint. In addition, there have been few epidemiological studies of the disease, and the profile of its incidence has yet to be well established in the Brazilian population. The objective of this study was to review the literature regarding the processes of malignant transformation, as well as the respective mechanisms of tumorigenesis, in MM.     

Molecular markers of Plasmodium falciparum drug resistance in southern highland Rwanda

In Rwanda, frequent mutations in the pfdhfr and pfdhps genes of Plasmodium falciparum have suggested intense sulfadoxine-pyrimethamine resistance. However, data on pfmdr1 are not available but might be important in the context of the first-line treatment with artemether-lumefantrine. During a survey among 749 children under five years of age in southern highland Rwanda, 104 P. falciparum isolates were obtained. Parasite polymorphisms associated with drug sensitivity were typed including the genes pfdhfr, pfdhps, pfmdr1, and pfcrt. Plasma concentrations of chloroquine and pyrimethamine were measured by ELISA. Treatment with artemether-lumefantrine within the preceding two weeks was stated by 12.5% of the respondents; chloroquine in plasma was detected in 17.6%, pyrimethamine in none. Isolates with pfdhfr triple and pfdhps double/triple mutations occurred in 75% and 93%, respectively; 69% of the isolates comprised pfdhfr/pfdhps quintuple or sextuple mutations associated with high-grade sulfadoxine-pyrimethamine resistance. Pfdhfr L164 was absent. The pfmdr1 pattern revealed more than 50% of the F184 polymorphism and almost 40% of the N86-F184-D1246 allele combination known to be selected in infections reappearing following artemether-lumefantrine treatment. Molecular markers demonstrate intense antifolate drug resistance of P. falciparum in southern Rwanda. The present, first-time data on pfmdr1 alleles from Rwanda reveal a pattern which might reflect a predominance of wild types for some alleles or, alternatively, substantial artemether-lumefantrine pressure on the local parasite population.