Acute renal failure needing dialysis in the intensive care unit and prognostic scores

BACKGROUND: Generic prognostic scores used in acute renal failure (ARF) give imprecise results; disease-specific indices applied to distinct populations or intensive care practices becomes inaccurate. The current study evaluates the adequacy of prognostic scores, in patients with severe ARF needing dialysis. METHODS: Known generic (APACHE II) and disease-specific (ATN-ISS) indices were applied to a cohort (n = 280) with ARF needing dialysis, under intensive care. Possible risk factors as causal factors, organ dysfunctions and clinical variables were examined, and a local index assembled by multivariate logistic regression analysis. Area under the receiver operating characteristics (ROC) curves evaluated the indices discriminating capacity. Goodness-of-fit testing and linear regression analysis appraised calibration. Validation was accomplished by the bootstrapping technique. The end-point was hospital mortality. RESULTS: Overall mortality was 85%. Female gender < 44 years (OR: 0.29; 95% CI: 0.10-0.84), liver/obstructive biliary disease (OR: 6.03; 95% CI: 1.65-22.08), being conscious (OR: 0.49; 95% CI: 0.21-1.14), use of vasoactive drug (OR: 3.13; 95% CI: 1.25-7.83), respiratory dysfunction (OR: 5.20; 95% CI: 1.25-7.83) or sepsis (OR: 2.62; 95% CI: 1.14-6.02) were associated with outcome. Areas under the ROC curve of 0.815, 0.652 and 0.814; Goodness-of-fit test P = 0.593, P < 0.001 and P = 0.002; and linear regression R2 = 0.973, R2 = 0.526 and R2 = 0.919 for the local index, APACHE II and ATN-ISS, respectively, indicate better performance by the local index. The local index median area under the ROC curve, by bootstrapping, was 0.820 (95% CI: 0.741-0.907). CONCLUSIONS: APACHE II score was inaccurate, and ATN-ISS poorly calibrated. When mortality or intensive care practices significantly deviate, local scores may better evaluate prognosis in severe ARF.     

Lung microvascular permeability and neutrophil recruitment are differently regulated by nitric oxide in a rat model of intestinal ischemia-reperfusion

We investigated the effect of two inhibitors of nitric oxide (NO) synthesis, N(w)-nitro-L-arginine methyl ester (L-NAME) and aminoguanidine, on lung inflammation caused by intestinal ischemia/reperfusion in rats. Relative to the sham-operated rats, intestinal ischemia/reperfusion (ischemia: 45 min; reperfusion: 30 min, 2 and 4 h) induced neutrophil recruitment (increased myeloperoxidase activity) and increased microvascular permeability (Evans blue dye extravasation) in the lungs and increased tumor necrosis factor (TNF) levels in the serum (L-929 cytotoxicity assay). L-NAME given before the ischemia exacerbated neutrophil accumulation, plasma extravasation, serum TNF and caused death of the animals, which was prevented by concomitant injection of L-arginine. Lung and systemic effects of intestinal ischemia/reperfusion were not modified when L-NAME was given just before reperfusion. Treatment with aminoguanidine inhibited plasma extravasation without affecting the other parameters evaluated. Dexamethasone reduced all the parameters. Our results indicate that during intestinal ischemia/reperfusion both constitutive and inducible NO synthases are called to exert a differential modulatory effect on lung inflammation and that maintenance of adequate levels of NO during ischemia is essential for the animals survival.     

Evaluation of the mutagenic potential of urban air pollution in São Paulo, Southeastern Brazil, using the Tradescantia stamen-hair assay

We used a short‐term bioassay—the Tradescantia stamen‐hair assay (TSH)—to evaluate the toxicity of ambient particles with an aerodynamic diameter less than 10 μm sampled in the metropolitan region of São Paulo, Brazil. Two exposure locations were selected: downtown São Paulo and Caucaia do Alto (mean PM₁₀ levels of 64 and 14 μg/m³, respectively). The experiment was conducted July 11–August 15, 2002, and toxicity was assessed with the Tradescantia stamen‐hair assay (TSH) employing clone KU‐20 of Tradescantia. Four experimental groups were defined: inflorescences collected from plants cultivated in Caucaia, inflorescences collected from plants cultivated in São Paulo (to establish the baseline level of mutations in stamen hairs at both sites), inflorescences collected from plants cultivated in Caucaia and brought to São Paulo and maintained in chambers that received ambient air, and inflorescences collected from plants cultivated in Caucaia and brought to São Paulo and maintained in chambers that received air passed through a particle filter. The frequency of mutations observed in Caucaia was significantly lower than that in the remaining groups. Flower cuttings brought from Caucaia and receiving ambient air of São Paulo showed a rate of mutations similar to that of plants cultivated in São Paulo. Filtering particles from the air reduced the rate of mutation but not sufficiently to reach the level of that in Caucaia. The frequency of mutations observed in São Paulo was significantly associated with PM₁₀ levels on the fifth day before the opening of the flowers (r = 0.47, p = 0.025). Our results indicate that urban particles play a significant role in the development of pollution‐dependent mutations. © 2004 Wiley Periodicals, Inc. Environ Toxicol 19: 578–584, 2004.     

Metallic biomaterials TiN-coated: corrosion analysis and biocompatibility

Corrosion processes due to contact with the physiological environment should be avoided or minimized in orthopedic implants. Four metallic substrates frequently used as biomaterials: pure Ti, Ti-6Al-4V alloy, ASTM F138 stainless steel, and Co-Cr-Mo alloy, were coated with TiN using the physical vapor deposition (PVD) technique. These coatings have been screened by polarization curves in physiological solutions. TiN prepared by PVD is efficient as coating for stainless steel. On titanium and alloy there are no benefits concerning the corrosion resistance compared to the bare Ti-materials. TiN coatings have been screened according to ISO 10993 standard tests for biocompatibility and exhibited no cytotoxicity, dermal irritation, or acute systemic toxicity response.     

Ptychopetalum olacoides,a traditional Amazonian "nerve tonic", possesses anticholinesterase activity

The cholinergic hypothesis of Alzheimer disease (AD) has provided the rationale for the current pharmacotherapy of this disease, in an attempt to downgrade the cognitive decline caused by cholinergic deficits. Nevertheless, the search for potent and long-acting acetylcholinesterase (AChE) inhibitors that exert minimal side effects to AD patients is still an ongoing effort. Amazonian communities use traditional remedies prepared with Ptychopetalum olacoides (PO, Olacaceae) roots for treating various central nervous system conditions, including those associated with aging. The fact that PO ethanol extract (POEE) has been found to facilitate memory retrieval in the step down procedure in young and aged mice prompt us to evaluate its effects on AChE activity in memory relevant brain areas. POEE significantly inhibited AChE activity in vitro in a dose- and time-dependent manner in rat frontal cortex, hippocampus and striatum; a significant inhibition was also found in these same brain areas of aged (14 months) mice after acute administration of POEE (100 mg/kg ip). We propose that such AChE inhibitory activity is a neurochemical correlate of a number of therapeutic properties traditionally claimed for P. olacoides, particularly those associated with cognition.     

Prognostic factors for the survival of surgically treated patients for non-small cell lung cancer

The survival and outcome rates of 284 patients who underwent surgical treatment for non-small cell lung cancer were assessed retrospectively. Resectability rate was 94.1%, hospital mortality 3.9% (n=11) and the mortality rates in patients who underwent pneumonectomy or lobectomy were 8.9% and 0.6%, respectively. The overall 5-year survival was 43.6%. Female gender, earlier stages of disease and a complete resection were strongly predictive for a long-term survival. Women in stage IA disease had a 5-year survival rate of 92.7%. The 5-year survival rate for patients in stages IIIA and N2 disease who underwent a complete resection was 21.9%, and 9% for those who did not undergo a complete resection. It is concluded that the best surgical results were observed in women who were operated on at an early stage of disease. A complete resection also contributed to a better outcome, even for patients in stage IIIA and N2 disease.     

尿微量蛋白与老年2型糖尿病合并缺血性心脏病关系的研究

目的探讨在老年2型糖尿病合并缺血性心脏病患者中尿微量蛋白在加重缺血性心脏病进展方面的作用。方法将66例老年2型糖尿病合并缺血性心脏病患者按24h尿微量蛋白排泄量分为:尿微量蛋白正常组及尿微量蛋白阳性组,分别对血脂、空腹血糖、血清胰岛素、胰岛素敏感指数、纤维蛋白原、颈动脉内-中膜厚度、颈总动脉粥样硬化等级积分、硬化斑块指数、心脏彩超室间隔厚度及射血分数等加重缺血性心脏病进展等指标进行比较分析。结果66例老年2型糖尿病合并缺血性心脏病患者尿微量蛋白阳性组高密度脂蛋白、载脂蛋白A、胰岛素敏感指数、年龄、纤维蛋白原、硬化斑块指数、颈总动脉粥样硬化等级积分、室间隔厚度及射血分数显著高于尿微量蛋白阴性组(P<0.05,P<0.01)。结论尿微量蛋白的出现能够加速糖尿病合并缺血性心脏病的发展进程,它的出现预示着缺血性心脏病的预后不良。     

Detection of carbamyl phosphate synthetase 1 deficiency using duodenal biopsy samples

The activity of urea cycle enzymes was assayed in duodenal biopsy specimens obtained from a female infant who presented with neonatal hyperammonaemia. All enzyme levels were normal except N-acetyl glutamate-dependent carbamyl phosphate synthetase 1 (CPS1) which was half the mean activity in normal control specimens. A similar deficiency of CPS1 was also shown in duodenal specimens from the patient's mother who became slightly symptomatic after relatively high protein meals and during pregnancy, and had spontaneously modified her diet to one with protein restriction. The patient is growing normally on a dietary regimen similar to that spontaneously adopted by her mother. Urea cycle enzyme activity in the duodenal biopsy material from the controls was similar to that found in the normal human liver and appears to have distinct advantages as a means of assaying for urea cycle defects in patients with hyperammonaemia and their relatives.     

Flexion compromises ventilation with the laryngeal tube suction II in children

Background: There are insufficient data as to the influence of the head and neck flexion, extension, and rotation on the ventilation with laryngeal tube suction II^® (LTS II). The purpose of this study was to investigate the influence of the head and neck position on oropharyngeal sealing pressure (primary outcome) and ventilation score (secondary outcome) during ventilation with the LTS II in children. Methods: We studied 33 children scheduled for elective surgery. Oropharyngeal sealing pressure and ventilation score were measured with the head and neck in a neutral position, flexed, extended and rotated to the right. The ventilation score was scored from 0 to 3 based on three items (no leakage with an airway pressure of 15 cmH₂O, bilateral chest excursion, and a square wave capnogram; each item scored 0 or 1 point). Peak inspiratory pressure (PIP) at a tidal volume of 10 ml·kg^?1 and fiberoptic laryngeal views were also assessed in each position. Results: Although the sealing pressure was lower in the extended position [22 (8) cmH₂O] than that in the neutral position [25 (7) cmH₂O], there was no significant leakage during ventilation with a tidal volume of 10 ml·kg^?1. In the neutral, extended and rotated positions, the median ventilation scores were better (3 point respectively) than that with the head and neck flexed (1 point). PIP was decreased with the head and neck extended or rotated but was significantly increased in flexion position. During fibreoptic examination, the vocal cords were more easily seen in extension and right rotation, compared with the neutral position and flexion. Conclusions: Although oropharyngeal sealing pressure is decreased with the head and neck extended, effective ventilation with LTS II can be performed like in the neutral position or the rotated position. While the sealing pressure is maintained with the head and neck flexed, flexion compromises the ventilation with LTS II in children.