Oral feeding trajectories and neurodevelopmental outcomes at 12 and 24 month follow-up for preterm infants

BACKGROUND

Few studies characterize feeding performance in the NICU when predicting neurodevelopmental outcomes. Our objective was to investigate the relationship between time to full oral feeds (FULL-PO) and neurodevelopmental and feeding outcomes in the first 2 years in preterm infants admitted to the NICU.

METHODS

This retrospective study included infants born between 01/01/2014-07/31/2017, gestational age < 32 weeks and/or birth weight < 1500 g. We examined feeding difficulties, cerebral palsy, and Bayley scores for those reaching FULL-PO at a post menstrual age (PMA)≤38.0 weeks (EARLY) vs.>38.0 weeks (LATE). Additionally, the oral feeding achieved at various timepoints between 36- and 42-weeks postmenstrual age (PMA) was measured to construct a timeline of oral feeding acquisition.

RESULTS

Of 192 infants, 147(77%) achieved FULL-PO EARLY and 45(23%) LATE. Comorbidities and length of stay were higher and unadjusted Bayley scores were lower at 12 months corrected age (CA) and 24 months chronological age (CH) in the LATE group. Feeding difficulties were higher in the LATE group at 24 months CH. Infants born < 27-28 weeks GA were more likely to achieve oral feeding at a later PMA. Infants with bronchopulmonary dysplasia (BPD) had significant feeding and developmental delays.

CONCLUSIONS

Establishing full oral feeds by 38.0 weeks PMA may be used as a predictor for feeding difficulties at 24 months CH. Infants born < 27-28 weeks GA and those with BPD are more likely to take extended amounts of time to achieve full oral feeding and need additional feeding support. Infants with BPD are high risk for neurodevelopmental delays.

Clinical Outcomes and Safety Comparison of Vertebroplasty, Balloon Kyphoplasty, and Vertebral Implant for Treatment of Vertebral Compression Fractures

BACKGROUND AND PURPOSE

Vertebral compression fracture represents a major health burden for the aging populations globally. However, limited studies exist on the relative efficacy and safety of surgical interventions for vertebral compression fracture. Here, we aim to compare clinical and patient-reported outcomes following vertebral augmentation using balloon kyphoplasty, vertebroplasty, and SpineJack vertebral implant.

MATERIALS AND METHODS

An institutional review board-approved, retrospective, multi-institutional review of patients undergoing vertebral augmentation with kyphoplasty, vertebroplasty, and/or a SpineJack vertebral implant was performed between 2018 and 2021. Primary outcomes included pre- and postprocedural pain ratings and vertebral body height restoration. The secondary outcome was a change in the local kyphotic angle. The Kruskal-Wallis test was used to compare outcomes across 3 treatment options. Complications were reviewed during and 30-90 days after the procedure.

RESULTS

Vertebral augmentation of 344 vertebral compression fracture levels was performed during the study period. Sixty-seven patients had 79 kyphoplasty procedures (55% women; mean age, 64.2 [SD, 12.3] years). Seventy-four patients underwent a mean of 84 vertebroplasty procedures (51% women; mean age, 63.5 [SD, 12.8] years), and 61 patients had a mean of 67 SpineJack vertebral implant procedures (57.4% women; mean age, 68.3 [SD, 10.6] years). Following kyphoplasty, vertebroplasty, and SpineJack vertebral implant, pain scores improved significantly (P < .001). Resting pain improvement was similar across the 3 procedures, whereas improvement of "worst pain" was significantly better following a SpineJack vertebral implant compared with kyphoplasty and vertebroplasty (P < .001). Patients with a SpineJack vertebral implant had greater improvement in vertebral body height restoration and local kyphotic angle compared with those undergoing kyphoplasty and vertebroplasty. Adjacent level fractures (6.7% incidence) occurred similarly in the 3 procedure types. There were no other peri- or postoperative complications.

CONCLUSIONS

The SpineJack vertebral implant showed equivalent pain improvement compared with vertebroplasty and kyphoplasty, but it had superior vertebral body height restoration and local kyphotic angle improvement. This study supports the SpineJack vertebral implant as a safe and effective alternative (adjunct) for vertebral augmentation, especially in patients with moderate-to-severe vertebral compression fractures for greater improvement in vertebral body height restoration.

MRI diagnosis of tumor‑like IgG4 masses in bilateral distal ureters: A case report

IgG4 masses in the bilateral distal ureters are rare and frequently misdiagnosed. The present study reported the case of a 55-year-old male patient with IgG4-related disease (IgG4-RD) who had symmetrical soft tissue masses of the bilateral distal ureters found on magnetic resonance imaging (MRI) with a significant increase in the serum levels of IL-6, IgG4 and IgE. Regarding treatment, this patient received prednisone acetate tablets (40 mg/day) and mycophenolate mofetil dispersible tablets (1 g/day). During the follow-up, significant reductions in the levels of IgG4 and IgE were found after 30 days. MRI after 6 months indicated complete disappearance of the masses. The prognosis has been good so far. In clinical practice, it is necessary to consider the possibility of IgG4-RD in cases with soft tissue masses surrounding both ureters and elevated levels of serum IgG4.

Intraoperative Neuromonitoring during Peripheral Arteriovenous Malformation Embolization

PURPOSE

To evaluate whether intraoperative neuromonitoring (IONM), including pre-embolization lidocaine injection challenge ("provocative testing") is associated with reduced risk of irreversible nerve injury during embolization of peripheral arteriovenous malformations (AVMs).

MATERIALS AND METHODS

Medical records of patients with peripheral AVMs who underwent embolotherapy with IONM with provocative testing between 2012 and 2021 were reviewed retrospectively. Data collected included patient demographic characteristics, AVM location and size, embolic agent used, IONM signal changes after lidocaine and embolic agent injections, postprocedural adverse events, and clinical outcomes. Decisions regarding whether embolization would proceed at specific locations were based on IONM findings after the lidocaine challenge and as embolization proceeded.

RESULTS

A cohort of 17 patients (mean age, 27 years ± 19; 5 women) who underwent 59 image-guided embolization procedures with adequate IONM data was identified. No permanent neurologic deficits occurred. Transient neurologic deficits were observed in 3 patients (4 sessions), comprising skin numbness (2 patients), extremity weakness (1 patient), and extremity weakness and numbness (1 patient). All neurologic deficits resolved by postoperative day 4 without additional treatment.

CONCLUSIONS

IONM, including provocative testing, during AVM embolization may minimize potential nerve injury.

Reconstruction of the three-dimensional beat pattern underlying swimming behaviors of sperm

 The eukaryotic flagellum propels sperm cells and simultaneously detects physical and chemical cues that modulate the waveform of the flagellar beat. Most previous studies have characterized the flagellar beat and swimming trajectories in two space dimensions (2D) at a water/glass interface. Here, using refined holographic imaging methods, we report high-quality recordings of three-dimensional (3D) flagellar bending waves. As predicted by theory, we observed that an asymmetric and planar flagellar beat results in a circular swimming path, whereas a symmetric and non-planar flagellar beat results in a twisted-ribbon swimming path. During swimming in 3D, human sperm flagella exhibit torsion waves characterized by maxima at the low curvature regions of the flagellar wave. We suggest that these torsion waves are common in nature and that they are an intrinsic property of beating axonemes. We discuss how 3D beat patterns result in twisted-ribbon swimming paths. This study provides new insight into the axoneme dynamics, the 3D flagellar beat, and the resulting swimming behavior.

Clinical outcomes and safety of the SpineJack vertebral augmentation system for the treatment of vertebral compression fractures in a United States patient population

The SpineJack implant system was recently FDA approved for treatment of vertebral compression fractures (VCF), however United States-based outcomes data is lacking. We sought to examine the safety and clinical outcomes following vertebral augmentation using the SpineJack implant for treatment of VCF in a U.S. patient population. An IRB-approved, retrospective study of SpineJack implants used in vertebral augmentation was performed from 11/2018 to 2/2020. Outcome objectives included pain improvement, vertebral body height (VH) restoration, improvement in local kyphotic angle (LKA), and incidence of adjacent level fractures (ALF). Complications were reviewed to assess safety of the procedure. Thirty patients with VCF (60% female; mean [SD] age of 62.7 [±12.8] years) underwent a total of 53 vertebral augmentations with 106 SpineJack implants. Worst pain scores decreased significantly from 8.7 to 4.3 (95%CI of the change [Δ]: 4.3-4.4; p < 0.001). Middle and anterior VH significantly increased from 13.1 ± 0.2 to 15.9 ± 0.2 mm (95%CI Δ: 2.6-2.9 mm; p < 0.001) and 15.6 ± 0.2 to 16.8 ± 0.2 mm (95%CI Δ: 1.1-1.4 mm; p < 0.001), respectively. LKA was significantly decreased from 10.0 ± 2.1 to 7.4 ± 2.1 degrees (95%CI Δ: 2.4-2.8 degrees; p < 0.001). Four patients (13%) sustained ten ALF over a median (IQR) follow up period of 94 (17.5-203) days. There were no major adverse events during the follow up period. To summarize, vertebral augmentation with SpineJack implants of patients with VCF resulted in significantly decreased pain, restored VH, and improved LKA, without major adverse events. However, 13% of patients sustained ALF during a median follow up period of 3 months.

The steering gaits of sperm

Sperm are highly specialized cells, which have been subject to substantial evolutionary pressure. Whereas some sperm features are highly conserved, others have undergone major modifications. Some of these variations are driven by adaptation to mating behaviours or fitness at the organismic level. Others represent alternative solutions to the same task. Sperm must find the egg for fertilization. During this task, sperm rely on long slender appendages termed flagella that serve as sensory antennas, propellers and steering rudders. The beat of the flagellum is periodic. The resulting travelling wave generates the necessary thrust for propulsion in the fluid. Recent studies reveal that, for steering, different species rely on different fundamental features of the beat wave. Here, we discuss some examples of unity and diversity across sperm from different species with a particular emphasis on the steering mechanisms. This article is part of the Theo Murphy meeting issue 'Unity and diversity of cilia in locomotion and transport'.

Protein arginine methyltransferase 1 promotes epithelial-mesenchymal transition via TGF-β1/Smad pathway in hepatic carcinoma cells

Protein arginine methyltransferase 1 (PRMT1) is dysregulated in a number of human cancers. Herein, we report that PRMT1 expression is directly associated with epithelial-mesenchymal transition (EMT) in hepatic carcinoma cells. Firstly, we find that PRMT1 expression is higher in hepatic carcinoma tissues than that in normal liver tissues at both mRNA and protein levels, and higher expression of PRMT1 correlates with poor survival in liver tumors. The data in vitro reveals that PRMT1 knockdown inhibits the abilities of proliferation, migration and invasion, while PRMT1 overexpression promotes the above behaviors in hepatic carcinoma cells. Further studies indicate that PRMT1 knockdown remarkably decreases the expression of mesenchymal markers including Vimentin, Snail and N-cadherin, and upregulates expression of epithelial markers E-cadherin. Conversely, PRMT1 overexpression results in the opposite effects. Additionally, we identified that PRMT1 knockdown resulted in downregulation of TGF-β1, p-Smad2 and p-Smad3, while PRMT1 overexpression activated TGF-β1, p-Smad2 and p-Smad3. These findings suggest that PRMT1 promotes EMT in hepatic carcinoma cells probably via TGF-β1/Smad pathway, and might represent a novel anti-liver cancer strategy.

MicroRNA-29A/PTEN pathway modulates neurite outgrowth in PC12 cells

PTEN serves as an intrinsic brake on neurite outgrowth, but the regulatory mechanism that governs its action is not clear. In the present study, miR-29a was found to increase neurite outgrowth by decreasing PTEN expression. Results showed that miR-92a-1, miR-29a, miR-92b, and miR-29c expression levels increased during nerve growth factor (NGF)-induced differentiation of PC12 cells. Based on in silico analysis of possible miR-29a targets, PTEN mRNA may be a binding site for miR-29a. A protein expression assay and luciferase reporter assay showed that miR-29a could directly target the 3'-UTRs (untranslated regions) of PTEN mRNA and down-regulate the expression of PTEN. PC12 cells infected with lentiviral pLKO-miR-29a showed far higher levels of miR-29a and Akt phosphorylation level than those infected with control. This promoted neurite outgrowth of PC12 cells. Collectively, these results indicate that miR-29a is an important regulator of neurite outgrowth via targeting PTEN and that it may be a promising therapeutic target for neural disease.

Serum Inflammatory and Immune Mediators Are Elevated in Early Stage Diabetic Nephropathy

BACKGROUND

Diabetes is the leading cause of end stage renal disease (ESRD) in the United States, representing 44% of incident cases [1]. In this study, serum and peripheral blood collected from diabetic patients in five stages of chronic kidney disease (CKD), as defined by glomerular filtration rate (GFR), were compared to healthy (non-CKD) subjects.

METHODS

Serum samples were analyzed for 39 inflammatory or immune mediator protein levels and peripheral blood samples were analyzed for expression of 35 gene transcripts.

RESULTS

In serum, MCP-1, FGF-2, VEGF, and EGF levels were elevated above controls at all stages of DN. Five mediator levels, GM-CSF, IL-1α, IL-1RA, IL-6, and MIP1β increased with disease progression until stage 4-5, at which point a decrease was observed paralleling a loss of functional renal mass that occurs in late stage CKD. Five mediator levels: GRO, IFNγ, MDC, Eotaxin, and G-CSF significantly differed from controls at one or more stages without apparent correlation with disease stage. Only a single mediator, sIL2RA, exhibited a linear increase with disease severity consistent with declining GFR. In peripheral blood, the transcript level of seven mediators, ICAM1, TNF-α, TGF-β, IL-8, IL17RA, IFNγ, and MYD88 were significantly elevated at all disease stages as compared to control.

CONCLUSION

Statistically significant differences in protein and transcripts levels between diseased and control can be detected in serum and peripheral blood utilizing high content profiling. These changes occur as early as stage 1-2 before a significant decline in renal function.

ZNF185, an actin–cytoskeleton-associated growth inhibitory LIM protein in prostate cancer

We have recently identified ZNF185 as a gene that is downregulated in prostate cancer (PCa), in part via epigenetic alteration, and maybe associated with disease progression. In this study, we cloned the ZNF185 cDNA from normal human prostate tissues and investigated its biological function. We show that ZNF185 is a novel actin-cytoskeleton-associated Lin-l 1, Isl-1 and Mec-3 (LIM) domain-containing protein that localizes to F-actin structures, and is enriched at focal adhesions. We find that the NH(2)-terminal region, which we designate the actin-targeting domain, facilitates ZNF185 binding to actin in vitro and is both necessary and sufficient to mediate actin-cytoskeleton targeting of ZNF185, whereas the LIM domain, which is localized in the COOH-terminus is dispensable for this phenomenon. Interestingly, ectopic expression of full-length ZNF185, but not a mutant lacking the actin-targeting domain, could suppress proliferation and anchorage-independent growth of PCa cells. Together, our data suggest that ZNF185 may function as a tumor-suppressor protein by associating with the actin-cytoskeleton.

Water movement across rat bile duct units is transcellular and channel-mediated

In recent studies using freshly isolated rat cholangiocytes, we established that water crosses the cholangiocyte membrane by a channel-mediated mechanism involving aquaporins, a family of water-channel proteins. Our goal was to address the importance of channel-mediated water transport in ductal bile formation by employing a physiologic experimental model, the enclosed, polarized rat intrahepatic bile duct unit (IBDU). Expansion and reduction of luminal areas as a reflection of water movement into and out of IBDUs prepared from livers of normal rats were measured by quantitative computer-assisted image analysis. When enclosed IBDUs were exposed to inward or outward osmotic gradients, their luminal area rapidly increased (approximately 25%) or decreased (approximately 20%) reflecting net water secretion or absorption, respectively. These effects were specifically inhibited by 2 water channel blockers, DMSO and HgCl2. In both instances, beta-mercaptoethanol reversed the inhibitory effects. In the absence of an osmotic gradient, choleretic agents (secretin and forskolin) and a cholestatic hormone (somatostatin) induced a significant increase or decrease of IBDU luminal area by 21% and 22%, respectively. These effects were also inhibited by DMSO and reversed by beta-mercaptoethanol. Under our experimental conditions, DMSO did not interfere with either forskolin-induced cAMP synthesis or the generation of osmotic driving forces via the apical chloride-bicarbonate exchanger. Protamine, an inhibitor of the paracellular pathway, had no effect on hypotonic or forskolin-induced water secretion in IBDUs. These results in a physiologically relevant model of ductal bile formation provide additional support for the concept that osmotically driven and agonist-stimulated water movement into (secretion) and out of (absorption) the biliary ductal lumen is transcellular and water channel-mediated.

Dynamics and mechanism of ultraviolet photolysis of atrazine on soil surface

The photolysis of atrazine in the soil surface under UV light and the factors affecting this has been studied. A rate constant of 0.09-0.17 min-1, photolytic depth of 0.1-0.3 mm and half-life of 4-8 min were determined. The results show that soil granularity, pH, humidity, organic content, humic acid and surface-active agents could affect the photolysis of atrazine in soil. GC-MS showed three photolytic products: 1-sec-butyl-4,4-diethyl-1-tetrazene, N2,N4-diethyl-6-methyl-1,3,5-triazine-2,4-diamine and 6-chloro-N2-propyl-1,3,5-triazine-2,4-diamine. The mechanism of the photolytic process is discussed.

[Multimedia environmental behavior of herbicide atrazine]

In the paper, taking the Baiyangdiang Lake area as a study field, on the basis of soil characterization, environmental monitoring, and studies of adsorption, biodegradation, hydrolysis and photolysis, the atrazine concentrations in soil, groundwater and corn plant during 30 years were predicted by multimedia environmental fugacity model.

The role of Ultrabithorax in the patterning of adult thoracic muscles in Drosophila melanogaster

Mutations in the homeotic gene, Ultrabithorax (Ubx), result in the transformation of the third thoracic (T3) segment into the second thoracic (T2) segment. Although it has been well established that these mutations have striking effects on adult epidermal structures in T3, the effect of these mutations on the adult musculature has been controversial. In this study, a series of Ubx regulatory mutations, anterobithorax, bithorax, postbithorax, and bithoraxoid, as well as combinations of these alleles were used to reevaluate the role of Ubx in the patterning of the T3 musculature. Homeotic indirect and direct flight muscles (IFMs and DFMs) were identified in the transformed T3 segment of all alleles and allelic combinations with the exception of postbithorax. We critically evaluated the pattern and amount of these muscles and found that while the amount and/or quality of homeotic IFMs increased, the amount of homeotic DFMs did not vary significantly as the severity of the ectodermal transformation increased. Because Ubx is not expressed in the adult mesoderm of T3, these results suggest that inductive cues play a major role in the patterning of adult thoracic muscles. We provide a model that illustrates the central role of inductive cues in generating the final adult muscle pattern in the thorax.

Effects of embryonic treatment with fadrozole on phenotype of gonads, syrinx, and neural song system in zebra finches

Previous studies have found that treatment of zebra finch embryos with an aromatase inhibitor on Day 5 or 8 of incubation caused partial sex reversal of gonadal phenotype in females. These females possessed both testicular and ovarian tissue, and the development of the neural circuit for song remained feminine. The present study attempted more complete gonadal reversal by treating zebra finch embryos earlier, on Day 3 of incubation, with Fadrozole (CGS 16949A), an aromatase inhibitor, or with saline. We examined the phenotype of the syrinx (androgen-dependent vocal organ), the gonads, and the telencephallic neural song system in 100-day-old birds. Treated females typically possessed a left ovotestis and a right testis, and significantly larger syringes than control females. The histology and steroid synthetic enzyme activity of the testicular tissue in treated females were quite masculine and similar to that of control males. At the time of sacrifice, the plasma concentrations of testosterone and estradiol for fadrozole-treated females did not differ from those of control females, but dihydrotestosterone was lower in treated females. Despite the large amount of functional testicular tissue and a masculine syrinx, the volumes and soma sizes of song system nuclei (HVC, RA) in treated females remained feminine. These results suggest that testicular secretions masculinize the syrinx, but are not sufficient to masculinize the song system in zebra finches.

Analysis of trace atrazine and simazine in environmental samples by liquid chromatography-fluorescence detection with pre-column derivatization reaction

Coupled with off-line extraction, a pre-column derivatization liquid chromatographic fluorescence detection (LC-FL) procedure was developed for the determination of atrazine and simazine in soil, crop and water samples. Concentrations in real samples were expected to be at or below the low ng/g level, which requires pre-concentration of analytes and improved detection. 4-(2-Phthalimidyl) benzoyl chloride (PIB-Cl) was used as a pre-column derivation reagent for high-performance liquid chromatography. The clean-up and second-time concentration procedures, which were indispensable in the conventional analytical methods for soil and crop analysis because of the complexity of the samples, were replaced by a derivatization reaction between PIB-Cl and the analytes. The fluorescent and ultraviolet characteristics of the derivatives were investigated. The derivatization reaction and chromatographic separation conditions were optimized systematically. Detection limits of 1.2 ng/g for atrazine and 1.1 ng/g for simazine were obtained with recoveries of 84-95% for environmental samples. On the basis of practical application to five soil and five crop samples, the LC-FL method was compared with the conventional GC-MS method.

Effects of embryonic estrogen on differentiation of the gonads and secondary sexual characteristics of male zebra finches

Male zebra finches sing to court females, whereas females do not normally sing. In parallel, the telencephalic brain regions that control song are larger in volume and contain larger cells in males than in females. The vocal control organ (syrinx) is also larger in males. Some evidence suggests that the sexual differentiation of both anatomy and behavior is under the regulation of gonadal hormones during early development, yet recent data conflict with the idea that the sole source of masculinization of the neural song system is the testes. In the present experiment, we treated genetic males with estradiol benzoate on embryonic day 5 and measured the volume of and neuron soma size in robust nucleus of the archistriatum (RA) and the high vocal center (HVC), two telencephalic song control nuclei. We also weighed the syrinx, the muscles of which are the target of the motor pathway containing the two brain regions. The estrogen treatment disrupted testicular morphology, and induced an oviduct in six of seven animals, but it had no effect on any of four measures of masculinization of the neural song system. These results suggest that normal testicular tissue is not required for masculine development of the neural song system.

One-year follow-up evaluation of 260 premature infants with respiratory distress syndrome and birth weights of 700 to 1350 grams randomized to two rescue doses of synthetic surfactant or air placebo. American Exosurf Neonatal Study Group I

A multicenter, randomized, double-blind, placebo-controlled trial of synthetic surfactant therapy for premature infants with respiratory distress syndrome (RDS) and birth weights of 700 to 1350 gm demonstrated a reduction in severity of RDS, morbidity, and neonatal and 1-year mortality. Of the 419 infants who were entered in the study, 80% of the surviving infants in both the air placebo group (122) and the synthetic surfactant group (138) returned for the follow-up evaluation at 1-year adjusted age. The only significant difference observed at follow-up was a reduction in the incidence of mild cerebral palsy in the synthetic surfactant group (air placebo group, 8 of 122 (7%); synthetic surfactant group, 3 of 138 (2%); relative risk 0.306; 95% confidence interval 0.094, 0.999). No differences were observed between the air placebo and synthetic surfactant treatment groups with respect to health status of the infants, including the incidence of retinopathy of prematurity and neurodevelopmental delays. The difference in the overall incidence of impairment among the 1-year survivors in the air placebo group (43 of 122 (35%)) and in the synthetic surfactant group (40 of 138 (29%)) was not statistically significant. The results of this 1-year follow-up study show that rescue treatment with synthetic surfactant in infants weighing 700 to 1300 gm is not associated with adverse developmental consequences despite the improvement in survival.

Controlled trial of a single dose of synthetic surfactant at birth in premature infants weighing 500 to 699 grams. The American Exosurf Neonatal Study Group I

In a multicenter, double-blind, placebo-controlled trial conducted at 23 hospitals in the United States, a single prophylactic 5 ml/kg dose of a synthetic surfactant (Exosurf Neonatal) or air placebo was administered shortly after birth to 215 infants with birth weights of 500 to 699 gm. Despite stratification at entry by birth weight and gender, by chance female infants predominated in the air placebo group and male infants predominated in the surfactant group. Among infants receiving synthetic surfactant, improvements in oxygen requirements were significant at 2 hours after birth (p = 0.014) and persisted for 3 days (p = 0.001); improvements in the alveolar-arterial partial pressure of oxygen gradient were significant at 6 hours after birth (p = 0.01) and persisted for 3 days (p = 0.008). Improvements in mean airway pressure were not significant at 2 or at 6 hours after birth (p = 0.622 and 0.083, respectively), but became significant thereafter and persisted for 3 days (p = 0.002). Pneumothorax was reduced by slightly more than half (25 vs 11; p = 0.014); death from respiratory distress syndrome (RDS) was also reduced (26 vs 15; p = 0.046). Overall neonatal mortality, however, was not significantly reduced (58 vs 46; p = 0.102). Other complications of RDS and prematurity were not altered, except that pulmonary hemorrhage occurred significantly more frequently in infants receiving synthetic surfactant (2 vs 12; p = 0.006). These findings indicate that a single prophylactic dose of synthetic surfactant in infants weighing 500 to 699 gm at birth improves lung function, incidence of air leak, and death from RDS but not overall mortality. The only safety problem identified was an increase in pulmonary hemorrhage.

Effect of peripheral injection of arginine vasopressin and its receptor antagonist on burn shock in the rat

To investigate the effect of arginine vasopressin (AVP) in the peripheral circulation on burn shock in the rat, AVP and its nonselective V1/V2 receptor antagonist d(CH2)5Tyr (Et)VAVP were administered intravenously in burn shocked rats. Cardiovascular parameters were recorded including left ventricular systolic pressure (LVSP), +/- dP/dt max, total area of the cardiac force loop (Lo), mean arterial blood pressure (MAP), heart rate (HR) and electrocardiogram (ECG). Our results showed that AVP failed to increase MAP in burned rats whereas it elicited a greater fall in LVSP, +/- dP/dt max and Lo and MAP than seen in control burned rats and hastened the onset of the decompensatory phase of burn shock resulting in the early death of burn shocked animals. The receptor antagonist d(CH2)5Tyr(Et)VAVP elevated LVSP, +/- dp/dt max and Lo for the eight hour observation period, and allowed MAP to recover from the initial profound fall following burn injury. Furthermore, it prolonged the survival time of the burned rats. AVP treated rats also displayed earlier abnormal changes such as elevation of S-T segment, inversion of T wave and ventricular fibrillation in ECG. The onset of these changes was much delayed in antagonist treated rats.