Effect of surfactant replacement therapy on the outcome of premature infants with respiratory distress syndrome

Lung surfactant replacement has been tested clinically in recent years. In this study the outcome of 31 premature infants with moderate to severe neonatal respiratory distress syndrome (RDS) treated with surfactant was compared to that of 74 prematures with RDS treated conventionally by positive pressure ventilation and supportive care. The groups were well matched for gestational age, birthweight, sex, and Apgar scores at 1 and 5 min. Surfactant treatment resulted in a significant decrease in mortality--from 36.6% in the untreated group to 12.9% in the surfactant-treated group (P < 0.04). This improvement in survival was seen also in prematures with a birthweight < 1,000 g; in the untreated group mortality was 57.6% compared to 23.5% in the treated group (P < 0.05). The incidence of pneumothorax was lower in the treated group--42% vs. 13% (P < 0.01). Surfactant treatment resulted in a trend of more survivors without bronchopulmonary dysplasia or intraventricular hemorrhage, even though surfactant therapy did not change the incidence of either.     

Natural type selection in adaptive lossy compression

Consider approximate (lossy) matching of a source string ~P, with a random codebook generated from reproduction distribution Q, at a specified distortion d. Previous work determined the minimum coding rate R₁=R(P, Q, d) for this setting. We observe that for a large word length and with high probability, the matching codeword is typical with a distribution Q₁ which is different from Q. If a new random codebook is generated ~Q₁, then the source string will favor codewords which are typical with a new distribution Q₂, resulting in a minimum coding rate R₂=R(P, Q₁, d), and so on. We show that the sequences of distributions Q₁, Q ₂,... and rates R₁, R₂,..., generated by this procedure, converge to an optimum reproduction distribution Q*, and the rate-distortion function R(P, d), respectively. We also derive a fixed rate-distortion slope version of this natural type selection process. In the latter case, an iteration of the process stochastically simulates an iteration of the Blahut-Arimoto (1972) algorithm for rate-distortion function computation (without recourse to prior knowledge of the underlying source distribution). To strengthen these limit statements, we also characterize the steady-state error of these procedures when iterating at a finite string length. Implications of the main results provide fresh insights into the workings of lossy variants of the Lempel-Ziv algorithm for adaptive compression     

Achieving 1/2 log (1+SNR) on the AWGN channel with lattice encoding and decoding

We address an open question, regarding whether a lattice code with lattice decoding (as opposed to maximum-likelihood (ML) decoding) can achieve the additive white Gaussian noise (AWGN) channel capacity. We first demonstrate how minimum mean-square error (MMSE) scaling along with dithering (lattice randomization) techniques can transform the power-constrained AWGN channel into a modulo-lattice additive noise channel, whose effective noise is reduced by a factor of /spl radic/(1+SNR/SNR). For the resulting channel, a uniform input maximizes mutual information, which in the limit of large lattice dimension becomes 1/2 log (1+SNR), i.e., the full capacity of the original power constrained AWGN channel. We then show that capacity may also be achieved using nested lattice codes, the coarse lattice serving for shaping via the modulo-lattice transformation, the fine lattice for channel coding. We show that such pairs exist for any desired nesting ratio, i.e., for any signal-to-noise ratio (SNR). Furthermore, for the modulo-lattice additive noise channel lattice decoding is optimal. Finally, we show that the error exponent of the proposed scheme is lower bounded by the Poltyrev exponent.     

Results of reconstruction in major pelvic and extremity venous injuries

PURPOSE: Outcome and venous patency after reconstruction in major pelvic and extremity venous injuries was studied. METHODS: We retrospectively reviewed 46 patients with 47 venous injuries. RESULTS: Injuries were caused by penetrating trauma in 37 extremities, blunt trauma in 6 patients, and were iatrogenic in 4 patients. Pelvic veins were injured in 4 patients, lower-extremity veins were injured in 39 limbs in 38 patients, and upper-extremity veins were injured in 4 patients. Concomitant arterial injuries occurred in 37 patients. Venous repairs were mostly of the complex type and included spiral or panel grafts in 15 (32%) reconstructions, interposition grafts or patch venoplasty in 19 (40%) reconstructions, end-to-end and lateral repair in 11 patients, and ligation in 2 patients. Two patients underwent early amputation. Early transient limb edema occurred in 2 patients, and postoperative venous occlusions were documented in 4 patients. Full function was regained in 39 (81%) extremities. No variable, including 4 retrospectively applied extremity injury scores (mangled extremity severity score [MESS], limb salvage index [LSI], mangled extremity syndrome index [MESI], predictive salvage index [PSI]), correlated with outcome. High values on all 4 scores were significantly associated with reexplorations (P <.02), which were done in 8 patients for debridement (5), arrest of bleeding (2), and repair of a missed arterial injury (1). Follow-up of 28 +/- 6 months on 27 patients (57%; duplex scan in 18, continuous-wave Doppler and plethysmography in 9, and venography in 3) showed 1 occlusion 6 weeks after the injury and patency of all other venous reconstructions. CONCLUSION: Reconstructions of major venous injuries with a high rate of complex repairs result in a large proportion of fully functional limbs and a high patency rate. A high extremity injury score predicts the need for reexploration of the extremity. Mostocclusions occur within weeks of injury, and the subsequent delayed occlusion rate is very low.     

Nissen fundoplication by laparoscopy

Short term results following laparoscopic Nissen fundoplication were evaluated in 31 patients with symptomatic gastroesophageal reflux. 6 were females and 26 males, and they ranged in age from 5 months to 64 years (mean: 4.9 years in 19 younger than 18 years, and 39.3 years in 12 adults). Most of the adults who complained of pain and heartburn underwent pH monitoring, endoscopy, and manometry as needed. Milk scan was the most useful diagnostic tool for the evaluation of the children, who suffered mainly from gastroesophageal-related pulmonary disease. Indications for laparoscopic operation were identical with those for conventional open Nissen fundoplication. 1 case of dysautonomia died postoperatively; the rate of complications, mostly minor, was 22.5%. 3 patients required conversion to open Nissen fundoplication due to cardiorespiratory instability secondary to pneumothorax in 2, and to esophageal perforation in the third. 5 adults developed temporary dysphagia. 3 children had only partial improvement in their pulmonary disease following the operation, while the other 15 had complete relief. The total time for the laparoscopic operation averaged 245 minutes in adults, and 228 in children. Discharge was usually on the fourth postoperative day in adults (mean: 6.0 days). Regurgitation and heartburn were cured in 10 out of 11 adults (91%). All parents of children were satisfied. Symptomatic outcomes following laparoscopic Nissen fundoplication compare favorably with those of open surgery with respect to mortality, complications, and outcome.     

Joint Wyner–Ziv/Dirty-Paper Coding by Modulo-Lattice Modulation

The combination of source coding with decoder side information (the Wyner-Ziv problem) and channel coding with encoder side information (the Gel'fand-Pinsker problem) can be optimally solved using the separation principle. In this work, we show an alternative scheme for the quadratic-Gaussian case, which merges source and channel coding. This scheme achieves the optimal performance by applying a modulo-lattice modulation to the analog source. Thus, it saves the complexity of quantization and channel decoding, and remains with the task of ldquoshapingrdquo only. Furthermore, for high signal-to-noise ratio (SNR), the scheme approaches the optimal performance using an SNR-independent encoder, thus it proves for this special case the feasibility of universal joint source-channel coding.     

Fabrication of polyethyleneimine surface-functionalized fluorescent carbon dots and its applications towards highly sensitive and selective detection of glutathione in aqueous medium and in vitro cell imaging of HeLa cells

Journal of Materials Science: Materials in Electronics - The present study aimed to synthesize polyethyleneimine (PEI) surface-functionalized fluorescent carbon dots (CDs)-based biosensor...     

Outbreak of subclinical mastitis in a flock of dairy goats associated with atypical Staphylococcus haemolyticus

Staphylococcus haemolyticus is a pathogen frequently isolated from dairy cows and small ruminants. However, it always appears in only a few animals and not as a major pathogen. Recently, in a dairy goat herd of approximately 250 milking animals, 25.6% (46/180 goats) had milk cultures with atypical highly mucoid colonies accompanied by elevated somatic cell counts. The isolates were identified as Staph. haemolyticus. The present study describes the steps used in an attempt to identify the bacterium and to compare it with other coagulase-negative staphylococci (CNS) including Staph. haemolyticus. Species identification performed with the API STAPH-IDENT 32 kit showed >99.4% identity confirmed by 16S rDNA sequencing tests. Microscopically the atypical Staph. haemolyticus strains showed unique cuboidal tetrad clusters reminiscent of those of the genus Sarcina. The outbreak caused by an atypical CNS underlines the need for accurate biochemical and genetic methods for ultimate identification of CNS to the species level.