Hypoxia-Induced Kidney Injury in Newborn Rats.

Exposure to hypoxia during the early postnatal period can have adverse effects on vital organs. Neonatal Sprague-Dawley rats housed in a hypoxic chamber were compared to those in a normoxic chamber from postnatal days 0 to 7. Arterial blood was collected to evaluate renal function and hypoxia. Kidney morphology and fibrosis were evaluated using staining methods and immunoblotting. In the kidneys of the hypoxic group, protein expressions of hypoxia-inducible factor-1 were higher than those in the normoxic group. Hypoxic rats had higher levels of hematocrit, serum creatinine, and lactate than normoxic rats. Body weight was reduced, and protein loss of kidney tissue was observed in hypoxic rats compared to normoxic rats. Histologically, hypoxic rats showed glomerular atrophy and tubular injury. Renal fibrosis with collagen fiber deposition was observed in the hypoxic group. The expression of nicotinamide adenine dinucleotide phosphate oxidases was enhanced in the kidneys of hypoxic rats. Proteins involved in apoptosis were upregulated in the kidneys of hypoxic rats. An increase in the expression of pro-inflammatory cytokines was also observed in the kidneys of hypoxic rats. Hypoxic kidney injury in neonatal rats was associated with oxidative stress, inflammation, apoptosis, and fibrosis.

Effects of early aminophylline therapy on clinical outcomes in premature infants.

BACKGROUND: Aminophylline use and the association between clinical outcomes and therapy timing have been less investigated. The objective of this study was to determine the efficacy of early aminophylline use (within the first two days of life) in premature infants. METHOD: A retrospective observational cohort of infants weighing <1500 g and <30 weeks of gestational age at Kaohsiung Veterans General Hospital received aminophylline either within the first two days of life (EA, early aminophylline group), after the third day of life (LA, late aminophylline group), or without aminophylline during the first month of life (WA, without aminophylline group). Demographic data and neonatal clinical outcomes were compared among the three groups. RESULTS: This study included 89 preterm infants (EA = 33, LA = 38, WA = 18). The EA group had a lower incidence of bronchopulmonary dysplasia (BPD) than the WA group (adjusted odds ratio [aOR] = 8.86(1.56-59.32); P = 0.024). Although there was no significant difference in BPD incidence between the EA and LA groups (aOR = 2.66(0.51-13.81), P = 0.244), a trend remained. Birth body weight less than 1000 g was also a significant risk factor for BPD (aOR = 8.86(1.32-47.41), P = 0.014). The duration of mechanical ventilation was shorter in the infants in the EA group compared to the WA group (estimated beta = -11.344(-19.57-3.12); P = 0.008). CONCLUSION: Early aminophylline administration may be associated with a decreased incidence of BPD in preterm infants. However, the clinical benefits of aminophylline treatment require further investigation. In addition, a birth body weight of less than 1000 g was a crucial risk factor for BPD.

Low-Dose Propranolol Prevents Functional Decline in Catecholamine-Induced Acute Heart Failure in Rats.

Severe hyper-catecholaminergic states likely cause heart failure and cardiac fibrosis. While previous studies demonstrated the effects of beta-blockade in experimental models of single-catecholamine excess states, the detailed benefits of beta-blockade in more realistic models of hyper-adrenergic states are less clearly understood. In this study, we examined different therapeutic dosages and the effects of propranolol in rats with hyper-acute catecholamine-induced heart failure, and subsequent cardiopulmonary changes. Rats (n = 41) underwent a 6 h infusion of epinephrine and norepinephrine alone, with additional low-dose (1 mg/kg) or high-dose propranolol (10 mg/kg) at hour 1. Cardiac and pulmonary tissues were examined after 6 h. Catecholamine-only groups had the lowest survival rate. Higher doses of propranolol (15 mg/kg) caused similarly low survival rates and were not further analyzed. All low-dose propranolol rats survived, with a modest survival improvement in the high-dose propranolol groups. Left ventricular (LV) systolic pressure and LV end-diastolic pressure improved maximally with low-dose propranolol. Cardiac immunohistochemistry revealed an LV upregulation of FGF-23 in the catecholamine groups, and this improved in low-dose propranolol groups. These results suggest catecholamine-induced heart failure initiates early pre-fibrotic pathways through FGF-23 upregulation. Low-dose propranolol exerted cardio-preventative effects through FGF-23 downregulation and hemodynamic-parameter improvement in our model of hyper-acute catecholamine-induced heart failure.

Direct formation of small Cu2O nanocubes, octahedra, and octapods for efficient synthesis of triazoles.

In most studies describing the preparation of Cu2O crystals of various morphologies, the particle sizes are normally hundreds of nanometers to micrometers due to rapid particle growth, so they are not exactly nanocrystals. Here we report surfactant-free formation of sub-100 nm Cu2O nanocrystals with systematic shape evolution from cubic to octahedral structures by preparing an aqueous mixture of Cu(OAc)2, NaOH, and N2H4 solution. Adjustment of the hydrazine volume enables the particle shape control. Uniform nanocubes and octahedra were synthesized with edge lengths of 37 and 67 nm, respectively. Novel Cu2O octapods with an edge length of 135 nm were also produced by mixing CuCl2 solution, SDS surfactant, NaOH solution, and NH2OH · HCl reductant solution. All of them are nearly the smallest Cu2O nanocrystals of the same shapes ever reported. These small cubes, octahedra, and octapods were employed as catalysts in the direct synthesis of 1,2,3-triazoles from the reaction of alkynes, organic halides, and NaN3 at 55 °C. All of them displayed high product yields in short reaction times. The octahedra enclosed by the {111} facets are the best catalysts, and can catalyze this cycloaddition reaction with high yields in just 2 h when different alkynes were used to make diverse triazole products. Hence, the small Cu2O particles provide time-saving, energy-efficient, and high product yield benefits to organocatalysis.

Aqueous phase synthesis of palladium tripod nanostructures for Sonogashira coupling reactions.

In this work, palladium tripod nanocrystals have been synthesized by mixing an aqueous solution of cetyltrimethylammonium bromide (CTAB) surfactant, Na(2)PdCl(4), copper acetate, and ascorbic acid at 30 °C for 3 h. Addition of a small amount of copper ion source is critical to the formation of these tripods with a pod length reaching 100 nm. The incorporation of Cu atoms into the Pd tripods has been verified. The entire Pd tripod is single-crystalline with their branches growing along the [111] and [200] directions. Formation of side branches can be observed in some tripods. Triangular nanoplates are initially formed and evolved into the tripod structure in 20-30 min of reaction. Further growth leads to elongation of the pods. The large Pd tripods can serve as active and recyclable catalysts for a broad range of Sonogashira coupling reactions in water using a variety of aromatic halides containing electron-donating and -withdrawing substituents.