Ambient air pollution and cardiovascular emergency department visits in potentially sensitive groups

Limited evidence suggests that persons with conditions such as diabetes, hypertension, congestive heart failure, and respiratory conditions may be at increased risk of adverse cardiovascular morbidity and mortality associated with ambient air pollution. The authors collected data on over 4 million emergency department visits from 31 hospitals in Atlanta, Georgia, between January 1993 and August 2000. Visits for cardiovascular disease were examined in relation to levels of ambient pollutants by use of a case-crossover framework. Heterogeneity of risk was examined for several comorbid conditions. The results included evidence of stronger associations of dysrhythmia and congestive heart failure visits with comorbid hypertension in relation to increased air pollution levels compared with visits without comorbid hypertension; similar evidence of effect modification by diabetes and chronic obstructive pulmonary disease (COPD) was observed for dysrhythmia and peripheral and cerebrovascular disease visits, respectively. Evidence of effect modification by comorbid hypertension and diabetes was observed in relation to particulate matter less than 10 microm in aerodynamic diameter, nitrogen dioxide, and carbon monoxide, while evidence of effect modification by comorbid COPD was also observed in response to ozone levels. These findings provide further evidence of increased susceptibility to adverse cardiovascular events associated with ambient air pollution among persons with hypertension, diabetes, and COPD.     

A double-blind,placebo-controlled trial of sertraline for depressive symptoms in patients with stable,chronic schizophrenia

There have been no studies specifically examining the efficacy of selective serotonin reuptake inhibitor antidepressants for the symptoms of depression in schizophrenia. This study aimed to determine the efficacy and safety of sertraline as a treatment for depressive symptoms in patients with stable, chronic schizophrenia. The Beck Depression Inventory (BDI) was used as the principal outcome measure and other measures of depressive symptoms as secondary outcome measures. Twenty-six patients were entered into a double-blind, placebo-controlled, 8-week trial of sertraline and were included in the intent-to-treat (ITT) analysis (13 in each group). Eight patients in the sertraline group and 12 in the placebo group completed at least four weeks in the study and were considered to have had adequate treatment. On the ITT analysis, the mean score on the BDI fell 14.5% for the sertraline group and 5.6% for the placebo group (p > 0.05); the mean score on the Hamilton Depression Rating Scale (HDRS) fell 16.99% for the sertraline group and 8.3% for the placebo group (p > 0.05). When the analysis was repeated for those who had received adequate treatment, the mean BDI score fell by 28% for the sertraline group and 6% for the placebo group (p = 0.1); the mean HDRS score fell 31% for the sertraline group and 8.6% for the placebo group (p = 0.02). On the Clinical Global Impression-Improvement Scale, 10 of the 13 patients on sertraline improved against four of the 13 in the placebo group (p = 0.05). Sertraline-treated patients showed a significant improvement on the anxiety/ depression subscale of the BPRS on ITT analysis (F = 10.1, p = 0.004). There was no significant effect on negative or positive symptoms. Sertraline was well tolerated. The results suggest that sertraline is useful as a treatment for depressive symptoms in schizophrenia.     

Standardized interpretation of paediatric chest radiographs for the diagnosis of pneumonia in epidemiological studies

BACKGROUND: Although radiological pneumonia is used as an outcome measure in epidemiological studies, there is considerable variability in the interpretation of chest radiographs. A standardized method for identifying radiological pneumonia would facilitate comparison of the results of vaccine trials and epidemiological studies of pneumonia. METHODS: A WHO working group developed definitions for radiological pneumonia. Inter-observer variability in categorizing a set of 222 chest radiographic images was measured by comparing the readings made by 20 radiologists and clinicians with a reference reading. Intra-observer variability was measured by comparing the initial readings of a randomly chosen subset of 100 radiographs with repeat readings made 8-30 days later. FINDINGS: Of the 222 images, 208 were considered interpretable. The reference reading categorized 43% of these images as showing alveolar consolidation or pleural effusion (primary end-point pneumonia); the proportion thus categorized by each of the 20 readers ranged from 8% to 61%. Using the reference reading as the gold standard, 14 of the 20 readers had sensitivity and specificity of > 0.70 in identifying primary end-point pneumonia; 13 out of 20 readers had a kappa index of > 0.6 compared with the reference reading. For the 92 radiographs deemed to be interpretable among the 100 images used for intra-observer variability, 19 out of 20 readers had a kappa index of > 0.6. CONCLUSION: Using standardized definitions and training, it is possible to achieve agreement in identifying radiological pneumonia, thus facilitating the comparison of results of epidemiological studies that use radiological pneumonia as an outcome.     

Chronic ethanol up-regulates the synaptic expression of the nuclear translational regulatory protein AIDA-1 in primary hippocampal neurons

Recent studies have identified synaptic proteins that undergo synapse-to-nucleus translocation in response to neuronal activity that modulate protein synthesis. One such translational regulatory protein of the postsynaptic density (PSD) is AIDA-1d, which binds to PSD-95 via its C-terminus. Activation of synaptic NMDA receptors induces the cleavage of AIDA-1d, and the N-terminus is then shuttled to nuclear Cajal bodies where it plays a role in regulating global protein synthesis. Chronic ethanol exposure has been shown to increase the synaptic clustering of NMDA receptors and PSD-95. Here, we tested the hypothesis that AIDA-1d regulates chronic ethanol-induced increases in synaptic NMDA receptor expression. As reported, we found that AIDA-1 was highly enriched in dendritic spines and co-localized with PSD-95. Acute NMDA treatment increased AIDA-1 colocalization with p80 coilin, a marker of Cajal bodies. Chronic treatment (4 day) of cultures with ethanol (25–100 mM) or with the NMDA receptor antagonist AP-V (50 μM) enhanced the clustering of AIDA-1 at synaptic sites. However, chronic ethanol treatment (50 mM) in the presence of the NMDA receptor agonist NMDA (2.5 μM) prevented this increase. Surprisingly, PSD-95 did not seem to play a role in the synaptic distribution of AIDA-1 as this distribution was not affected by declustering PSD-95 from synapses in response to inhibition of palmitoylation. We found that lentiviral knockdown of AIDA-1d did not affect protein expression levels of NMDA receptor subunits GluN1, GluN1 C2′, or GluN2B. The results of this study demonstrate that synaptic AIDA-1 expression is enhanced by chronic ethanol exposure that can be prevented by concurrent stimulation of NMDA receptors. In addition, we found that the association of AIDA-1 with PSD-95 is not required for its localization to the PSD. Moreover, we found that AIDA-1 does not regulate protein expression levels or alternative splicing of the GluN1 subunit of NMDA receptors.     

Modulators of internal Ca2+ stores and the spontaneous electrical and contractile activity of the guinea-pig renal pelvis

1. The role of internal Ca(2+) stores in the generation of the rhythmic electrical and contractile activity in the guinea-pig proximal renal pelvis was examined using intracellular microelectrode and muscle tension recording techniques. 2. Ryanodine (30 microM) transiently increased contraction amplitude, while caffeine (0.5 - 3 mM) reduced contraction amplitude and frequency. Contractility was also reduced by 2-aminoethoxy-diphenylborate (2-APB 60 microM), xestospongin C (1 microM), U73122 (5 microM) and neomycin (4 mM), blockers of IP(3)-dependent release from Ca(2+) stores. 3. 60 mM K(+) saline-evoked contractions were reduced by caffeine (1 mM), U73122 (5 microM) and neomycin (4 mM), but little affected by ryanodine or 2-APB (60 microM). 4. Spontaneous action potentials consisting of an initial spike followed by a long plateau were recorded (frequency 8.6+/-1.0 min(-1)) in small urothelium-denuded strips of proximal renal pelvis. 5. Action potential discharge was blocked in 75 and 35% of cells by 2-APB (60 microM) and caffeine (1 mM), respectively. In the remaining cells, only a truncation of the plateau phase was observed. 6. Cyclopiazonic acid (CPA 10 microM for 10 - 180 min), blocker of CaATPase, transiently increased contraction frequency and amplitude. Action potential durations were increased 3.6 fold. Contraction amplitude and frequency slowly declined during a prolonged (>60 min) CPA exposure. 7. We conclude that the action potential in caffeine-sensitive cells and the shoulder component of caffeine-insensitive action potential arise from the entry of Ca(2+) through Ca(2+) channels. The inhibitory actions of modulators of internal Ca(2+) release were partially explained by a blockade of Ca(2+) entry.     

Cages: outcome and complications

The coincidental development of minimal intervention techniques for carrying out anterior lumbar spinal fusion and the introduction of cages to provide mechanical support of introduced bone graft led to the development of a type of cage suitable for both minimal intervention use (laparoscopic) and for the standard open procedure (the BAK cage). Reported results concentrated in the main on feasibility, safety and fusion rate achieved, rather than clinical outcome. Laparoscopic insertion at the lumbosacral level was as safe as if the procedure was an open one, although there was a slighter higher incidence of retrograde ejaculation. Immediate post-operative morbidity was less with the laparoscopic procedure and discharge home and return to work was earlier. There was no long-term benefit from the laparoscopic procedure. Laparoscopic insertion at the L4/5 level was attended by a greater incidence of complications, and had a longer learning curve.     

Volumetric rendering techniques: applications for three-dimensional imaging of the hip

Volumetric rendering is a new approach to three-dimensional (3D) imaging that overcomes many of the drawbacks of currently available surface-rendering systems. Its application on the Pixar Imaging System in two cases of acetabular fracture was assessed to illustrate the features of the technique. The fast-computing architecture and large memory of this system allow rapid generation of a series of high-quality 3D images in each plane of rotation (x or spinal axis, z or somersaulting axis) that can be viewed as independent static images or as an animated real-time video loop. Editing to remove the normal contralateral hemipelvis enhances appreciation of acetabular abnormalities. Every pixel of computed tomographic data is preserved, allowing representation of both soft tissue and bone as translucent overlap. The presentation of data also allows detection of subtle abnormalities and features and minimizes the artifact generation common in surface-rendered images.