Classifying subgroups of patients with symptoms of acute coronary syndromes: A cluster analysis

The purpose of the study was to identify subgroups of patients presenting with acute coronary syndromes based on symptom clusters. Two hundred fifty‐six patients completed a symptom assessment in their hospital rooms. Latent class cluster analysis and analysis of variance were used to classify subgroups of patients according to selected clinical characteristics. Four subgroups were identified and labeled as Heavy Symptom Burden, Chest Pain Only, Sweating and Weak, and Short of Breath and Weak (model fit χ² [130,891, n = 256] = 867.5, p = 1.00). The largest group of patients experienced classic symptoms of chest pain and shortness of breath but not sweating. Younger patients were more likely to cluster in the Heavy Symptom Burden group (F = 5.08, p = .002). Interpretation of the clinical significance of these groupings requires further study. © 2010 Wiley Periodicals, Inc. Res Nurs Health 33:386–397, 2010     

大剂量强的松影响小鼠MHCI类基因表达的实验研究

目的 研究大剂量糖皮质激素药物强的松对小鼠MHCI类基因表达的影响。方法25只BALB／c小鼠随机分成两组,对照组10只,实验组15只,实验组每天给予强的松（20mg!kg）灌胃,共给药30天。实验结束后取肝脏、脾脏、肾脏和肺组织少许提取RNA,RT—PCR测定MHCI类基因mRNA的表达,Western印迹测定它们的蛋白表达。结果实验结束时,肝脏、脾脏、肾脏和肺组织的MHCI类基因mRNA表达分别为0．06、0．05、0．09和0．05,明显低于对照组;MHCI类基因蛋白表达分别为9．13、11．35、9．86和9．36,明显低于对照组。结论大剂量强的松能降低小鼠机体肝脏、脾脏、肾脏和肺组织的MHCI类基因mRNA和蛋白表达。     

Root canal preparation in mandibular premolars with TRUShape and Vortex Blue: A micro‐computed tomography study

A comparison of the preparation ability of two root canal instrumentation systems in oval‐shaped canals using micro‐computed tomography was undertaken. Thirty extracted, single‐rooted, human mandibular premolars with radiographically similar canal morphology were selected, allocated to two groups (N = 15) and prepared with TRUShape or Vortex Blue (VB). Each sample was subjected to three scans (20 μm resolution): pre‐preparation and after preparation to sizes #30 and #40. Three‐dimensional data sets were evaluated for canal volume, surface area and surface treatment. Matched axial slices in apical, middle and coronal root thirds were evaluated for cross‐sectional area, roundness and transportation. Preparation with both instruments increased canal volumes and surface areas similarly and significantly (P < 0.001) with no significant difference between groups. TRUShape significantly enhanced surface treatment at both apical sizes (P < 0.05). Transportation exceeded 100 μm in only eight out of 90 cross sections. Both instruments performed similarly during preparation. TRUShape, however, significantly enhanced surface treatment.     

In vivo 3D analysis with micro‐computed tomography of rat calvaria bone regeneration using periosteal cell sheets fabricated on temperature‐responsive culture dishes

Transplantable cell sheets containing osteoblasts were fabricated from periostea on temperature‐responsive culture dishes. This study demonstrated the time‐course of bone regeneration in living small animals. This continuous observation of bone regeneration was achieved by micro‐computed tomography (µCT), which assessed the osteogenic capability of periosteal cells without biodegradable scaffolds. Real‐time bone regeneration was non‐invasively monitored in a rat calvarial bone defect model, using µCT. Three‐dimensional (3D) images obtained over time by µCT clearly showed that two different bone regeneration modes, specific to the control and experimental groups, were observed. In the control group, bone was regenerated only from the periphery of the defect edges. In the experimental group, bone regeneration was observed in several small regions within the central portions of the defects that were covered by the transplanted cell sheets. However, bone regeneration observed after periosteal cell sheet transplantation was limited. The results of ALP staining and the time‐course observations concluded that periosteal cell sheets contained a small fraction of cells that could differentiate osteoblasts. Fibroblasts in transplanted cell sheets or from around subcutaneous tissues suppressed bone regeneration. The periosteal cell sheets had a capability to produce ectopic regenerated bones. Therefore, to increase the content of osteogenic cells in harvested cell sheets, the enrichment of cells that could produce osteoblasts was expected by the modification of the initial cell preparation and the culture conditions. With further possible improvements, scaffold‐free periosteal cell sheet fabricated on temperature‐responsive culture dishes will be a valuable method for inducing and accelerating bone regeneration. Copyright © 2010 John Wiley & Sons, Ltd.     

Toxic effects of l-aspartic acid at high dose levels on kidneys and salivary glands in Fischer 344 rats detected in a 90-day feeding study

A subchronic oral toxicity study of l-aspartic acid (l-Asp) was conducted with groups of 10 male and 10 female Fischer 344 rats fed a powder diet containing 0%, 0.05%, 1.25%, 2.5% and 5.0% concentrations for 90 days. Serum biochemistry showed treatment-related decreases of blood urea nitrogen, creatinine and uric acid levels in both sexes. In addition, incidences of urinary ketone and protein were significantly increased in treated both sexes, while relative kidney weight was significantly increased in the 5.0% male rat, and regenerative renal tubules with tubular dilation were histopathologically observed in male rats of the 2.5% or greater groups. The observed renal injury was confirmed not to be due to accumulation of alpha2u-globulin. Acinar cell hypertrophy of salivary glands was histopathologically evident in male and female rats of the 2.5% or greater groups. The present results indicate that l-Asp causes toxic effects on kidneys and possibly salivary glands at high dose levels in male and female Fischer 344 rats. Such toxic effects were observed only in animals given 2.5% and/or higher doses of l-Asp. In conclusion, the no-observed-adverse-effect-level (NOAEL) for l-Asp is 1.25% (696.6 mg/kg body weight/day for males and 715.2 mg/kg body weight/day for females) under the present experimental conditions.     

Tn5090-like class 1 integron carrying blaVIM-2 in a Pseudomonas putida strain from Portugal

Three Pseudomonas putida strains containing bla_VIM-2 were isolated from an inanimate surface of a female ward sanitary facility in the Hospital Infante D. Pedro, Aveiro. A novel class 1 integron was found in strain Pp2 (aacA41bla_VIM-2/aac6'-IIc disrupted by an insertion sequence IS1382), and strain PpI was found to carry a class 1 integron (aacA7/bla_VIM-2/aacCl/aacA4), which is described for the first time in this species. Strain PFI carries a class 1 integron associated with a Tn5090-like transposon, constituting the first finding of this type of arrangement in a strain from Portugal. This association highlights further dissemination of bla_VIM-2 in environmental hospital isolates.