RDS

The efficacy of surfactant preparations used in the prevention and treatment of respiratory distress syndrome (RDS) is a well known fact; however, many controversies remain. The debate over which surfactant to be used, when and what is the best mode of delivery is still raging.
Currently, animal-derived surfactants are preferred and clearly recommended by various practice guidelines, but new synthetic surfactants containing peptides that mimic the action of surfactant proteins are emerging and they seem to have a comparable efficacy profile to the natural surfactants. It is hoped that with further improvements, they will outperform their natural counterparts in terms of reliability and cost-effectiveness.
Early surfactant administration was shown to further reduce the risk of RDS and its complications. However, as nasal continuous positive airway pressure(nCPAP) is becoming increasingly the preferred first line therapy for RDS, the less invasive approaches of respiratory support along with early selective surfactant administration (e.g. INSURE) appears to provide a better option.
Although neonatal RDS is still the main indication of surfactant therapy, other pathological processes received considerable attention and major research has been dedicated to explore the role of surfactant in their management, Meconium aspiration syndrome (MAS) and congenital pneumonia are two worthy examples.
The most updated practice guidelines do recommend the use of endotracheal instillation as the preferred mode of surfactant delivery. However, aerosolization and other non-invasive methods are being investigated with some success; nonetheless, further improvements are very much in need.

To assess whether the duration and magnitude of the shunt with patent ductus arteriosus (PDA) are related to a higher incidence of bronchopulmonary dysplasia (BPD) or death. A total of 242 infants ≤28 weeks gestational age were evaluated retrospectively between 2007 and 2012; 105 (43.3%) developed BPD or died (group 1) and 137 (56.6%) did not (group 2). A review of all echocardiographic evaluations performed from birth up to 36 weeks of postconceptional age or final ductal closure was carried out, to detect the presence of PDA, and estimate the severity of ductal shunt through the "PDA staging system" proposed by McNamara and Sehgal. Group 1 presented with a hemodynamically significant ductus arteriosus (DA) (E3 and/or E4-PDA) for a longer period of time vs group 2: 4.8 vs 2.3 days, respectively (P < .001). Persistence of a nonsignificant DA (E2) was not associated with development of BPD (P = .16). Each week of a hemodynamically significant DA represented an added risk...

To assess whether the duration and magnitude of the shunt with patent ductus arteriosus (PDA) are related to a higher incidence of bronchopulmonary dysplasia (BPD) or death. A total of 242 infants ≤28 weeks gestational age were evaluated retrospectively between 2007 and 2012; 105 (43.3%) developed BPD or died (group 1) and 137 (56.6%) did not (group 2). A review of all echocardiographic evaluations performed from birth up to 36 weeks of postconceptional age or final ductal closure was carried out, to detect the presence of PDA, and estimate the severity of ductal shunt through the "PDA staging system" proposed by McNamara and Sehgal. Group 1 presented with a hemodynamically significant ductus arteriosus (DA) (E3 and/or E4-PDA) for a longer period of time vs group 2: 4.8 vs 2.3 days, respectively (P < .001). Persistence of a nonsignificant DA (E2) was not associated with development of BPD (P = .16). Each week of a hemodynamically significant DA represented an added risk...

Using "snowball" in the study of hard-to-reach social groups will result in a non representative sample. This is due to the lack of information on the general population (investigator not known qualitative and quantitative information about the social group under study), nonrandom selection (only the most active enthusiasts are participate in the survey). Also, when using the "snowball" fairly large percentage of respondents discarded because of suspicion is not anonymous survey unwillingness contact with unfamiliar interviewer. This leads to uncontrolled bias in the sample and makes it impossible to estimate the error. A partial way out of this problem was the method of chain-referrals when the invitation to the survey handed over a group member, and not by the interviewer. This resulted in fewer failures. Development of this method was the RDS (respondent-driven sampling) by Douglas Heckathorn. The basis of this method is the "snowball", which tracked chains of referrers and referrals in a single step that can be used to estimate the "stability" property of the sample equilibrium of ergodic Markov chain (which can neutralize the effect of selection bias associated with the choice "seed" respondents). Further development of the method was proposed a number of assumptions: assessing its network of respondents (when respondents were asked to indicate the number of friends in the treatment group - the amount of own network), the property homophily (better respondents answered the questionnaire recommended by the members of their group), reciprocal ties (where the fact that the respondent knows the respondent in A, it follows that the respondent in the respondent knows A) and others. This made it possible to estimate the proportions of the group, the errors of these proportions and group volume and sample representation. On the other hand, the rate of questionnaires significantly exceeds the rate of the survey method "snowball" and other traditional ways. This method can be used not only for hard to reach social groups, and latent, about the structure of which the researcher has no information. Important results were obtained by Cyprian Wejnert and Douglas D. Heckathorn (2007), which examined the potential of the method RDS among students of Cornell University in 2004 and had the opportunity to check the results of the quantitative and qualitative characteristics of the social groups of the University to official data. This made it possible to accurately estimate error and deviation and accurately examine intra-group relations and design effect. The results of this study was to outline possible areas and cautions concerning the application of the method RDS. Another important contribution of this experiment was that it was conducted with the use of the Internet and email, which makes it possible to use it to study inaccessible and latent virtual social groups

Extensive mutational heterogeneity presents a significant barrier to the development of therapeutics for RDS-peripherin-linked autosomal-dominant retinitis pigmentosa (RP), for which more than 50 disease-related mutations have been identified to date. Mutation-independent suppression, using RNA interference (RNAi), together with simultaneous expression of a replacement rds gene (r-rds, which has been altered to escape suppression but nevertheless encodes wild-type protein) has been explored in COS-7 cells and mouse retinal explants. The efficacy of small interfering and short hairpin RNAs (si/shRNAs) silencing mouse rds, and the function of r-rds (containing degenerate substitutions in the RNAi target sequence) were analyzed at transcript (RT-PCR) and protein (ELISA) levels in COS-7 cells. “Dual-” and “triple-expression” constructs carrying the shRNA suppressor and the marker EGFP with or without the r-rds cassette were electroporated in vitro into retinal explants from 1-day-old pups. The retinae were dissociated at day 14, and transduced cells were FACS-sorted using the coexpressed EGFP marker and analyzed by RT-PCR. si/shRNAs decreased rds mRNA and protein expression by up to 82%, while r-rds was protected from suppression in COS-7 cells. Similarly, efficient RNAi-mediated suppression of endogenous rds was detected in retinal explants, while concomitant rescue of r-rds was also achieved. These data validate the concept of RNAi-based suppression coupled with replacement technology for the development of therapies targeting RDS-linked autosomal-dominant RP, and suggest that such approaches could potentially be used for other autosomal-dominant diseases with similarly extensive intragenic heterogeneity. Hum Mutat 27(3), 260–268, 2006. © 2006 Wiley-Liss, Inc.

Background: Antenatal glucocorticoid treatment (AGT) is associated with a number of postnatal benefits to the preterm infant, including reduced risk of respiratory distress syndrome, patent ductus arteriosus, intraventricular hemorrhage, and necrotizing enterocolitis. Objective: To evaluate the hypothesis that maternal AGT not only reduces the risk of surfactant deficiency but also reduces the occurrence of chronic lung disease (CLD) among surviving