Pullulan nanofibers containing the antimicrobial palindromic peptide LfcinB (21–25)Pal obtained via electrospinning

Electrospinning technology is useful for making ultrafine drug-eluting fibers for the clinical treatment of wounds. We show the incorporation of an antimicrobial LfcinB-derived peptide into Pullulan nanofibers. The palindromic peptide LfcinB (21–25)_Pal: RWQWRWQWR was synthesized, purified, and characterized by means of the RP-HPLC and MALDI-TOF MS methods. The peptide''s antibacterial activity against the E. coli ATCC 25922 strain was evaluated, and the peptide LfcinB (20–25)_Pal exhibited significant antibacterial activity. Nanofibers were obtained by electrospinning a Pullulan or Pullulan-LfcinB (21–25)_Pal solution. The obtained nanofibers were characterized via microscopy (AFM and SEM) and RP-HPLC chromatography. The peptide incorporation efficiency was 31%. The Pullulan-LfcinB (21–25)_Pal nanofibers were soluble in water, and the peptide was liberated immediately. The Pullulan-LfcinB (21–25)_Pal nanofibers exhibited the same antibacterial activity against E. coli strain as the free peptide LfcinB (21–25)_Pal. The results suggest that Pullulan-LfcinB (21–25)_Pal nanofibers could be considered for designing and developing antibacterial wound dressings.

Pullulan nanofibers containing antimicrobial peptide derived from LfcinB an option as biomaterial for wound dressings.     

Beta blockade by oral propranolol and labetalol

beta-Adrenergic blockade after single, oral doses of labetalol or propranolol was evaluated in a double-blind, placebo-controlled study by an isoproterenol sensitivity test and handgrip exercise in 10 healthy men. The tests were performed with subjects resting in a supine position. At the doses used, there was no effect on heart rate and blood pressure in either the resting position or in the isometric exercise phase. It is possible that exercise-induced changes in blood pressure and heart rate were reduced by higher vagal tone in this young group tested in the supine position. Isoproterenol increased heart rate and reduced diastolic blood pressure in a dose-dependent manner. The dose of isoproterenol at which heart rate increased 25 bpm above the resting rate (CD25; 1.36 +/- 0.18 microgram) was of the order of that at which diastolic blood pressure fell 25 mm Hg from baseline (HD25; 1.07 +/- 0.07 microgram). There was a significant positive correlation between CD25 and HD25 in the 10 subjects. Propranolol and labetalol induced a dose-dependent, parallel shift to the right in the dose-response curves of isoproterenol effects on heart rate and diastolic blood pressure, indicating that both drugs are nonselective, competitive antagonists of beta-adrenergic receptors. On the average, propranolol was 17 and 19 times more potent than labetalol in antagonizing the chronotropic and hypotensive actions of isoproterenol, respectively.     

Cardiovascular responses to Valsalva maneuver in physically trained and untrained normal subjects.

To elucidate whether the Valsalva maneuver (VM) can distinguish different degrees of normal ventricular function and parasympathetic tone, we studied 10 physically untrained and 18 trained normal individuals who regularly performed isotonic exercises. Both groups were submitted to an exercise stress test. An electrocardiogram and an M-mode echocardiogram were recorded before and during VM. The arterial pressure, heart rate and ventricular function responses to the maneuver were evaluated. The end diastolic volume, ejection fraction, circumferential fiber shortening and left ventricular posterior wall thickness were greater at rest in the trained group than in the untrained one. In both groups, during the straining phase of the VM the volumes and end systolic stress decreased and the systolic function indexes increased, but the changes were more pronounced in the trained subjects. In spite of these differences, the arterial pressure and heart rate responses were similar in both groups. It can thus be concluded that only changes in ventricular function distinguish physically trained vs untrained subjects during VM.     

Effects of moderate doses of vitamin A as an adjunct to the treatment of pneumonia in underweight and normal-weight children: a randomized, double-blind, placebo-controlled trial

BACKGROUND: Randomized controlled trials have shown inconsistent responses of childhood pneumonia to the use of vitamin A as an adjunct to the standard treatment of pneumonia. OBJECTIVE: We evaluated the effect of a moderate dose of vitamin A as an adjunct to standard antimicrobial treatment on the duration of respiratory signs in children with pneumonia. DESIGN: Children, aged 2-59 mo, with pneumonia and weight-for-age <50th percentile who had been admitted to the Baca Ortíz Children's Hospital in Quito, Ecuador, were randomly assigned to receive 50,000 IU (aged 2-12 mo) or 100,000 IU (aged >12-59 mo) vitamin A or a placebo. RESULTS: Of the 287 children enrolled, 145 received vitamin A and 142 received placebo. No overall differences were observed between the 2 groups in the duration of signs of pneumonia. Multiple linear regression showed a significant interaction between basal serum retinol concentration and vitamin A group for the time (in h) to remission of respiratory signs (beta = -3.57, SE = 1.09, P = 0.001). Duration of clinical signs was less in children with basal serum retinol concentrations >200 microg/L who received vitamin A supplements than in children with similar concentrations who received placebo (69.9 +/- 49.9 h compared with 131.3 +/- 143.9 h; P = 0.049). CONCLUSIONS: Overall, we found no effect of a moderate dose of vitamin A supplementation on the duration of uncomplicated pneumonia in underweight or normal-weight children aged <5 y. However, a beneficial effect was seen in children with high basal serum retinol concentrations.     

The spectrum of frontonasal dysplasia in an inbred pedigree

An inbred pedigree is described in which three members were affected with FND (Frontonasal Dysplasia). Two of these individuals werz products of a consanguineous mating with an inbreeding coefficient of F = 0.0391. The third affected individual (propositus), was born to a marriage in which the coefficient of inbreeding was 0.0742. The mother of the propositus, whose inbreeding coefficient was 0.0625, had borderline hypertelorism and a broad nose. Several other members of the pedigree who had hypertelorism were products of consanguineous matings. The presence of consanguinity in all individuals affected with a variety of manifestations of FND suggests a genetic mechanism for this malformation.     

Results of electrophysiologic studies in patients with acute chagasic myocarditis

Background: As the acute stage of Chagas' myocarditis is rarely detected, little is known about the electrophysiologic characteristics of that stage. Methods: We studied eight patients who had positive xenodiagnosis, positive mice culture, and positive complement fixation test for Chagas' disease. Results: Trypanosoma cruzi were identified in all of the patients' stained blood samples. Right ventricular endomyocardial biopsies were obtained, evidencing a distinct infiltrate of lymphocytes that confirmed the diagnosis of acute myocarditis. The cardiac dimensions and the ventricular systolic and diastolic function were preserved in all patients. The electrocardiogram evidenced conduction defects in two patients. The signal-averaged electrocardiogram displayed late potentials in three patients. In the electrophysiologic study, atrial fibrillation or flutter was induced in four patients. When compared with control patients, Chagasic patients were found to have greater values of atrial threshold, A-H interval, and atrioventricular (AV) nodal effective refractory period. The H-V interval was mildly prolonged in two patients, but the dynamic AV nodal conduction was preserved (1:1 conduction during right atrial stimulation at a cycle length of 400 ms) in all the Chagasic patients. The ventricular parameters were within normal limits, and no sustained ventricular arrhythmia could be induced. Conclusions: Patients with mild acute Chagasic myocarditis may suffer from electrical abnormalities and arrhythmias that are more evident at the supraventricular level and the AV junction. Hypothesis: This investigation was undertaken to conduct an electrophysiologic study of the properties of the heart during the acute phase of Chagasic myocarditis.     

Efficacy of ondansetron (GR 38032F) and the role of serotonin in cisplatin-induced nausea and vomiting.

We compared the efficacy and safety of ondansetron (GR 38032F), a selective antagonist of serotonin S3 receptors, with that of placebo in controlling the nausea and vomiting induced by cisplatin treatment in 28 patients with cancer. The patients received either three intravenous doses of ondansetron (0.15 mg per kilogram of body weight) or normal saline (placebo) at four-hour intervals, beginning 30 minutes before the administration of cisplatin. Nausea and vomiting were markedly diminished in the group given ondansetron. The median time to the first episode of emesis was 2.8 hours in the placebo group and 11.6 hours in the ondansetron group (P less than 0.001); the median number of episodes in 24 hours was 5.5 in the placebo group and 1.5 in the ondansetron group (P less than 0.001); the mean (+/- SEM) number of regurgitations or dry heaves per episode was 3.2 +/- 0.5 in the placebo group and 1.17 +/- 0.1 in the ondansetron group (P less than 0.001). None of the 14 patients given ondansetron, but 12 of 14 given placebo, required treatment with antiemetic-rescue agents for the control of nausea and vomiting. There were no adverse effects attributable to ondansetron. The urinary excretion of 5-hydroxyindoleacetic acid, the main metabolite of serotonin, was increased in all patients two to six hours after they received cisplatin chemotherapy, and the increases paralleled the episodes of emesis. We conclude that ondansetron is an effective and safe agent for controlling the nausea and vomiting induced by cisplatin treatment. We suggest that cisplatin treatment increases the release of serotonin from enterochromaffin cells, and that ondansetron acts by blocking S3 receptors for serotonin.     

Ectodermal dysplasia in females and inversion of chromosome 9.

Absence of sweat glands, hypotrichosis, hypodontia, characteristic facial features, and intolerance to heat, without dystrophia of the nails, are manifestations of sex linked hypohydrotic ectodermal dysplasia. Three males and two females were affected in a family in which the affected females were also carrying a pericentric inversion of chromosome 9. Those phenotypically normal females in this pedigree who were obligate carriers had normal karyotypes. One of the affected females (the proband) had, in addition, primary amenorrhoea, absence of the mammary glands, and rudimentary internal genitalia. The fact that clinical manifestations of ectodermal dysplasia in the carrier females of this family are only observed in those also carrying a pericentric inversion of chromosome 9 in peripheral blood leucocytes perhaps suggests that non-random inactivation of the paternal X chromosome has occurred as a consequence of the inversion.