Tissue ischemia, necrosis, and gangrene are uncommon but well-described complications of arterial catheterization in the neonate. Treatment options for progressive tissue necrosis following arterial embolization and/or vasospasm are limited in these patients secondary to unpredictable pharmacokinetics and risks associated with systemic anticoagulation or vasodilatation in newborns. We report a case of a multidose regimen of topical 2% nitroglycerin ointment for reversing severe tissue ischemia following peripheral arterial line placement. The favorable response in this infant suggests that topical nitroglycerin therapy should be considered as potential therapy to ameliorate the effects of vascular compromise following arterial line placement in neonates. 相似文献
The reaction of poly(styryl)lithium (PSLi) with hexa‐1,3,5‐triene (HXT) was studied as a route to diene‐functionalized macromonomers. When PSLi was reacted with 1.5 molar equivalents of HXT for 2.5 h at ?10 °C in toluene, it was found that the diene‐functionalized macromonomer was obtained in high yield; however, oligomerization of the HXT was observed by matrix‐assisted laser absorption ionization time‐of‐flight mass spectrometry (MALDI‐TOF MS). Oligomerization was eliminated by running the reaction with only 1.2 molar equivalents of HXT to PSLi and allowing the reaction to run for 15 min at ?10 °C in toluene. The resulting polymer exhibited high diene chain‐end functionality and no oligomerization was observed by MALDI‐TOF MS. 13C NMR spectroscopy and the attached‐proton test (APT), along with calculated chemical shifts, showed the presence of both the 1,2‐ and 1,4‐addition chain‐end structures. Further analysis by the reaction of the functional polymer with maleic anhydride indicated that 18 wt.‐% of the product was unreactive, either because of a 1,4‐addition chain‐end structure or a nonfunctional polymer. The structure of the maleic anhydride‐modified polymer was determined by MALDI‐TOF MS and 13C NMR spectroscopy. Preliminary work on the reactivity of the diene‐functionalized macromonomers was performed by the addition of a large excess of PSLi to a solution of macromonomer followed by characterization by size‐exclusion chromatography (SEC).
The formation of hexa‐1,3,5‐triene‐functionalized polystyrenes and their reaction with maleic anhydride. 相似文献
We describe non‐radiative energy‐transfer experiments to measure the rates of polymer interdiffusion in P(MMA‐co‐BA) latex films formed in the presence of poly(vinyl alcohol) (PVOH). PVOH had relatively little effect on the initial efficiency of energy transfer, even when the amount of PVOH was large enough to form the continuous phase. Since ΦET(0) is a measure of the interfacial area between D‐ and A‐labeled cells in the film, we conclude that under these circumstances the dispersed P(MMA‐co‐BA) copolymer is in the form of clusters with many contacts between particles containing D and A labels. These large amounts of PVOH also reduce the amount of polymer diffusion that takes place when the films are annealed. When smaller amounts of PVOH are present, the effects are measurable but much smaller. In the presence of 2 to 17 wt.‐% PVOH, the polymer diffusion rate is retarded. The magnitude of the effect increases with the amount of PVOH present, and the effect is larger at 45 °C than at 63 °C. We show that the PVOH has its largest influence at the very early stages of polymer diffusion.
Schematic representation of an energy transfer experiment, which monitors polymer interdiffusion in a latex film. 相似文献
Methimazole (methyl-mercapto-imidazole, MMI), a compound used clinically in therapy of Graves' thyroiditis, was found to inhibit development of several autoimmune diseases in animal models. It was suggested on the basis of in vitro data that inhibition is through down-regulation of interferon-gamma (IFN-gamma)-induced expression of major histocompatibility complex class I and class II molecules. Here, we investigate the effect of MMI on experimental autoimmune uveoretinitis (EAU) and study its mechanism(s). Treatment of EAU with MMI administered in drinking water inhibited induction of the disease and associated antigen (Ag)-specific proliferation and cytokine production by draining lymph node cells (LNCs). The treatment was protective only if administered during the first but not during the second week after immunization, suggesting an effect on the induction phase of EAU. It is interesting that MMI inhibited disease in IFN-gamma knockout mice, indicating that the in vivo protective effect is IFN-gamma-independent. Flow cytometric analysis of draining LNCs extracted 5 days after immunization showed that MMI partly to completely reversed the increase in Mac-1(+)/class I(+)/class II(+) cells induced by immunization and reduced the proportion of B7-1 and CD40-positive cells, suggesting a deficit in the Ag-presenting cell (APC) population. APC from untreated mice largely restored antigen-specific proliferation of MMI-treated LNCs. We suggest that MMI inhibits EAU at least in part by preventing the recruitment and/or maturation of APC, resulting in reduced generation of Ag-specific T cells. 相似文献
A case of a child with bilateral fleshy limbal masses with a coloboma of the right upper lid is discussed. Systemic examination
revealed two patches of alopecia on the right frontoparietal and right occipital areas of the scalp. Punch biopsy and histopathological
examination led to the diagnosis of Linear Nevus Sebaceus Syndrome (LNSS) with bilateral complex limbal choristomas.
The authors have stated that they do not have a significant financial interest or other relatioship with any product manufacturer
or provider of services discussed in this article. The authors also do not discuss the use of off-label products, which includes
unlabeled, unapproved, or investigative products or devices. 相似文献
OBJECTIVES: To determine whether pulse oximetry-detected episodes of desaturation are associated with impairment of cerebral and somatic (renal) tissue oxygenation in mechanically ventilated preterm neonates. DESIGN: Observational cross-sectional study. SETTING: Neonatal intensive care unit of a university-affiliated children's hospital. PATIENTS: Ten mechanically ventilated preterm (gestational age 24-32 wks) infants. INTERVENTIONS: In addition to the traditional monitoring of hemodynamic variables that included pulse oximetry (Sao2), near-infrared spectroscopy (NIRS) was used to evaluate the cerebral and somatic (renal) tissue oxygen saturation (rSO2C and rSO2R, respectively). MEASUREMENTS AND MAIN RESULTS: A total of 40 rSO2C and rSO2R measurements were simultaneously recorded: 20 during hypoxic events when the Sao2 was =80% for >/=4 secs (cases) and generally ranged between 70% and 80%, and 20 measurements when the Sao2 was >/=85% (paired controls). Additionally, the fractional oxygen extraction (FOE) from the cerebral (FOEC) and renal (FOER) tissue was calculated. All the measurements were made under steady conditions during a 2-hr period. The rSO2C, rSO2R, FOEC, and FOER among the cases (Sao2 = 80%) and controls (Sao2 >/= 85%) were compared using the paired Student's t-test. Both rSO2C and rSO2R during the desaturation episodes were lower than in the controls (51.6 +/- 6.3% vs. 66.2 +/- 10.2%, p < .0001 and 61.1 +/- 6.8% vs. 80.1 +/- 10.0%, p < .0001, respectively). The FOEC during the hypoxic episodes was comparable with control levels but increased in renal tissue. However, during two of the desaturation episodes (10%), the rSO2C and FOEC levels (which were <44% and >0.47, respectively) may reflect compromised tissue oxygen supply. CONCLUSIONS: In the majority of mechanically ventilated preterm neonates, the reduction in cerebral and renal tissue oxygenation associated with short periods of decreased arterial saturation to 70-80% does not significantly compromise oxygen utilization in the cerebral tissue but increases oxygen extraction in the renal tissue, which might cause ischemic tissue injury following a further reduction in oxygen delivery. 相似文献
High utilizers of alcohol and other drug treatment (AODTx) services are a priority for healthcare cost control. We examine characteristics of Medicaid-funded AODTx clients, comparing three groups: individuals < 90th percentile of AODTx expenditures (n = 41,054); high-cost clients in the top decile of AODTx expenditures (HC; n = 5,718); and 1760 enrollees in a chronic care management (CM) program for HC clients implemented in 22 counties in New York State. Medicaid and state AODTx registry databases were combined to draw demographic, clinical, social needs and treatment history data. HC clients accounted for 49% of AODTx costs funded by Medicaid. As expected, HC clients had significant social welfare needs, comorbid medical and psychiatric conditions, and use of inpatient services. The CM program was successful in enrolling some high-needs, high-cost clients but faced barriers to reaching the most costly and disengaged individuals. 相似文献