Dynamic ultrasound-guided short-axis needle tip navigation technique vs. landmark technique for difficult saphenous vein access in children: a randomised study.

Dynamic ultrasound-guided short-axis needle tip navigation is a novel technique for vascular access. After venipuncture, the needle and catheter are further advanced within the vessel lumen under real-time ultrasound guidance with constant visualisation of the needle tip in the short-axis view. This can minimise the risk of transfixing the cannulated vessel. We compared two techniques for non-visible saphenous vein cannulation under general anaesthesia in children weighing ≥ 3 kg and less than four years of age: dynamic ultrasound-guided short-axis needle tip navigation technique (ultrasound group) vs. landmark technique. Venous cannulation was performed by three experienced anaesthetists. The primary outcome measure was first-attempt success rate. Success rate within 10 min was a secondary outcome. A total of 102 patients were randomly allocated to either the ultrasound group or the landmark group. First-attempt success rate was 90% in the ultrasound group compared with 51% in the landmark group, p<0.001, difference 39%, 95% confidence interval (CI) of the difference 23-55%. Success rate within 10 min was 92% in the ultrasound group compared with 63% in the landmark group, p = 0.001, difference 29%, 95%CI of the difference 14-45%. We conclude that, when performed by experienced anaesthetists, the dynamic ultrasound-guided short-axis needle tip navigation technique improved non-visible saphenous vein cannulation in children compared with the landmark technique.

Effect of removal of cholesterol diet upon serum sickness-cholesterol-induced atherosclerosis.

In this report, the role of vascular allergy (i.e., hypersensitivity) in the potentiation of atherogenesis has been studied. In order to accomplish this, bovine serum albumin (BSA) was administered to rabbits in quantities sufficient to cause the occurrence of serum sickness (a type of hypersensitivity known to cause injury to the endothelial linings of certain blood vessels). This was immediately followed by the feeding of a special cholesterol-supplemented diet, which is known to be capable of initiating a high incidence of atheromatous disease in rabbits after prolonged feeding. Results indicated that those animals which received the combined treatment developed an incidence of pathology after only 2 wk of special diet which was not equaled in the diet-only control groups until they had been treated for 4 wk. This indicated that vascular allergy could potentiate lipemia-induced atherogenesis in the rabbit, and was in confirmation of an earlier study of a similar nature. Indeed, because of the relatively mild vascular injury caused by a single injection of BSA, it would seem as though vascular hypersensitivity was extremely effective in the potentiation of atherogenesis. In addition, these results may have given some indication of the degree of vascular injury necessary for the induction of irreversible atheromatous disease. While the incidence of lesions in serum sickness controls was seen to decrease with passage of time after BSA challenge, it appeared to increase after cessation of treatment in those animals which received the combined treatment of BSA plus 2 wk of cholesterol-supplemented diet. It would therefore appear that the atheromatous lesions seen as early as 2 wk after initiation of the experiment may already have been irreversible in terms of the resolution of established pathology.

Further studies on the reversibility of serum sickness cholesterol-induced atherosclerosis.

Rabbits were induced to form atheromatous cardiovascular lesions by subjecting them to treatments of a single BSA injection plus a 2-wk period of cholesterol diet, or to the diet alone. Microscopic examination of the hearts at the end of the 2-wk induction period, or after having been returned to regular diet for 5 or 8 wk, showed that lesion incidence in the cholesterol-only animall decreased markedly during the 8-wk rest period, while little change in incidence occurred in animals with lesions from the combined treatment. This finding was taken to mean that the latter type of lesion was less reversible, and therefore perhaps more pathologically significant, than the former type. It was felt that lipid deposition was not solely responsible for this prolongation, since it was present in diet-only lesions which disappeared with time, and also seemed to be disappearing from the prolonged lesions in all treatment groups. On the other hand, elastic tissue was demonstrated only in lesions arising from the combined treatment, and it is hypothesized that this feature is implicated in the prolongation of these lesions.

Antiallergic activity of tetracyclic derivatives of quinoline-2-carboxylic acids. 1.

Substitution of 1,4-dihydro-4-oxoquinoline-2-carboxylic acid by acetyl, benzoyl, and phenylsulfonyl substituents was found to enhance activity in the rat passive cutaneous anaphylaxis assay. A further increase in activity, to equipotency with DSCG, was achieved by incorporation of the 8-benzoyl moiety into a tetracyclic structure to give 1,4-dihydro-4,11(1H,11H)-dioxoindeno[1,2-h]quinoline-2-carboxylic acid (20). In contrast, the reverse isomer 19 was found to have little activity.

Inhibition of rat passive cutaneous anaphylaxis by 3-(tetrazol-5-yl)quinolines.

Quinoline-3-carboxylic acid (3) was found to have weak oral activity in the rat passive cutaneous (PCA) assay. In an effort to increase activity, the synthesis of structurally related compounds was initiated. This led to substituted 3-(tetrazol-5-yl)quinolines, some of which are equal in potency, when given orally, to doxantrazole. Further work resulted in the synthesis of 4-oxoquinolines, one of which, 8-chloro-1,4-dihydro-4-oxo-3-(tetrazol-5-yl)quinoline (132), is 33-fold more active than disodium cromoglycate (ip) and 32-fold more active than doxantrazole (po).

Volatile organic compounds, polycyclic aromatic hydrocarbons and elements in the air of ten urban homes.

Ten homes were monitored at regular intervals from June 1994 through April 1995 as part of a Public Health Assessment in Southeast Chicago for exposure to volatile organic compounds (VOCs), polycyclic aromatic hydrocarbons (PAHs), and elements. Simultaneous 24-h indoor and outdoor samples were collected. VOCs were and analyzed using USEPA Method TO-14 with Selected Ion Monitoring Mass Spectrometry (GC/MS). PAHs were analyzed using USEPA Method TO-13 with GC/MS. Elements were collected on quartz fiber filters and analyzed by Inductively Coupled Argon Plasma (ICP) spectroscopy or Graphite Furnace Atomic Absorption (GFAA). Continuous measurements of CO2 and temperature were recorded for each indoor sample. Twenty-four h total CO2 emissions were determined from occupancy and estimated gas stove usage and were moderately correlated (R2 = 0.19) with 24 h average indoor CO2 concentrations. Modeled 24-h air exchange rates ranged from 0.04 to 3.76 air changes h-1 (ACH), with mean of 0.52 ACH. Median particle penetration was 0.89. Emission rates were calculated for each pollutant sampled. Using a detailed housing survey and field sampling questionnaires, it was possible to evaluate associations between housing characteristics and source activities, and pollutant source rates. The data indicate that several predictor variables, including mothball storage, air freshner use, and cooking activities, are reasonable predictors for emission rates for specific pollutants in the homes studied.