A case study of exposure to ultrafine particles from secondhand tobacco smoke in an automobile

Secondhand tobacco smoke (SHS) in enclosed spaces is a major source of potentially harmful airborne particles. To quantify exposure to ultrafine particles (UFP) because of SHS and to investigate the interaction between pollutants from SHS and vehicular emissions, number concentration and size distribution of UFP and other air pollutants (CO, CO(2) , and PM(2.5)) were measured inside a moving vehicle under five different ventilation conditions. A major interstate freeway with a speed limit of 60 mph and an urban roadway with a speed limit of 30 mph were selected to represent typical urban routes. In a typical 30-min commute on urban roadways, the SHS of one cigarette exposed passengers to approximately 10 times the UFP and 120 times the PM(2.5) of ambient air. The most effective solution to protect passengers from SHS exposure is to abstain from smoking in the vehicle. Opening a window is an effective method for decreasing pollutant exposures on most urban roadways. However, under road conditions with high UFP concentrations, such as tunnels or busy freeways with high proportion of heavy-duty diesel trucks (such as the 710 Freeway in Los Angeles, CA, USA), opening a window is not a viable method to reduce UFPs.

PRACTICAL IMPLICATIONS

Time budget studies show that Americans spend, on average, more than 60 min each day in enclosed vehicles. Smoking inside vehicles can expose the driver and other passengers to high levels of pollutants. Thus, an understanding of the variations and interactions of secondhand tobacco smoke (SHS) and vehicular emissions under realistic driving conditions is necessary. Results of this study indicated that high ventilation rates can effectively dilute ultrafine particles (UFP) inside moving vehicles on urban routes. However, driving with open windows and an increased air exchange rate (AER) are not recommended on tunnels and heavily travelled freeways.

Inflammatory profiles in nasal mucosa of patients with persistent vs intermittent allergic rhinitis

BACKGROUND

To date there is little information on the inflammatory profiles of patients suffering from persistent (PER) and intermittent allergic rhinitis (IAR). Also, it is not clear whether differences exist in eosinophilic inflammation and/or T-helper cell sub-populations and their markers. The aim of this study was to primarily evaluate the inflammatory profiles of patients with moderate/severe PER and IAR.

METHODS

Inferior nasal turbinate tissue was obtained from 12 PER, 12 IAR and 12 nonallergic nonrhinitic (control) patients, and symptoms (visual analogue scales, VAS) and impairment of life was monitored. All tissues were assessed for eosinophil and mast cell numbers by immunohistochemistry; IL-5, ECP and IgE concentrations by immunoassay; mRNA for transcription factors GATA-3, T-bet, FOXP3 and RORc by quantitative real-time polymerase chain reaction; and IgE-induced release of LTC(4)/D(4)/E(4) and PGD(2)in vitro.

RESULTS

Eosinophils and mast cells were significantly increased in patients with PER and patients with IAR compared to control subjects; by patients with PER demonstrating even significantly greater increase of both cell types than patients with IAR. Similarly, ECP IL-5, GATA-3 mRNA expression and IgE-induced release of LTC4/D(4)/E(4) and PGD(2) from mast cells were significantly increased in patients with PER compared to patients with IAR. In contrast, the expression of T-bet, FOXP3 or RORc mRNA was not significantly different in the PER, IAR or control patients.

CONCLUSION

The findings from the present study suggest that PER is characterized by a significantly greater eosinophilic and predominantly Th2 cell-mediated nasal inflammatory profile compared to IAR.

Non-mammalian fat-1 gene prevents neoplasia when introduced to a mouse hepatocarcinogenesis model: Omega-3 fatty acids prevent liver neoplasia

We investigated the effect of a non-mammalian omega-3 desaturase in a mouse hepatocarcinogenesis model. Mice containing double mutations (DM) in c-myc and TGF-alpha (transforming growth factor-alpha), leading to liver neoplasia, were crossed with mice containing omega-3 desaturase. MRI analysis of triple mutant (TM) mice showed the absence of neoplasia at all time points for 92% of mice in the study. Pathological changes of TM (TGFalpha/c-myc/fat-1) mouse liver tissue was similar to control mouse liver tissue. Magnetic resonance spectroscopy (MRS) measurements of unsaturated fatty acids found a significant difference (p<0.005) between DM and TM transgenic (Tg) mice at 34 and 40 weeks of age. HPLC analysis of mouse liver tissue revealed markedly decreased levels of omega-6 fatty acids in TM mice when compared to DM (TGFalpha/c-myc) and control (CD1) mice. Mass spectrometry (MS) analysis indicated significantly decreased 16:0/20:4 and 18:1/20:4 and elevated 16:0/22:6 fatty acyl groups in both GPCho and GPEtn, and elevated 16:0/20:5, 18:0/18:2, 18:0/18:1 and 18:0/22:6 in GPCho, within TM mice compared to DM mice. Total fatty acid analysis indicated a significant decrease in 18:1n9 in TM mice compared to DM mice. Western blot analysis of liver tissue showed a significant (p<0.05) decrease in NF-kappaB (nuclear factor-kappaB) levels at 40 weeks of age in TM mice compared to DM mice. Microarray analysis of TM versus DM mice livers at 40 weeks revealed alterations in genes involved in cell cycle regulation, cell-to-cell signaling, p53 signaling, and arachidonic acid (20:4) metabolism. Endogenous omega-3 fatty acids were found to prevent HCC development in mice.

Comparisons of anterior segment biometry between Chinese and Caucasians using anterior segment optical coherence tomography

PURPOSE

To compare anterior segment parameters between eyes of Chinese and Caucasians using anterior segment optical coherence tomography and to evaluate the association between these parameters and anterior chamber angle width between the two ethnic groups.

METHODS

60 Chinese and 60 Caucasians, 30 with open angles and 30 with narrow angles (defined as Shaffer grade < or =2 in > or =3 quadrants during dark room gonioscopy) in each group, were consecutively enrolled. One eye of each subject was randomly selected for imaging in a completely darkened room. Measurements, including anterior chamber depth (ACD), scleral spur-to-scleral spur distance (anterior chamber width (ACW)), anterior chamber angle width, iris convexity and iris thickness, were compared between the groups. The associations between angle opening distance and biometric measurements were evaluated with univariate and multivariate regression analyses.

RESULTS

There were no differences in age, axial length, anterior chamber angle measurements, pupil diameter and iris convexity between Chinese and Caucasians in both open-angle and narrow-angle groups. However, the ACD and ACW were smaller and the iris was thicker in Chinese. In the multivariate analysis, the ACD was the most influential biometric parameter for angle opening distance in both Chinese and Caucasians. After adjusting the effects of axial length, age and sex, ACD and ACW were significantly smaller in Chinese.

CONCLUSIONS

Chinese eyes had smaller ACD, smaller ACW and greater iris thickness than Caucasians. ACD was the most influential parameter in determining the angle width in both ethnic groups.

TRAF6 knockdown promotes survival and inhibits inflammatory response to lipopolysaccharides in rat primary renal proximal tubule cells

AIM

TRAF6 is a unique adaptor protein of the tumour necrosis factor receptor-associated factor family that mediates both tumour necrosis factor receptor (TNFR) and interleukin-1 receptor/Toll-like receptor (IL-1R/TLR) signalling. Activation of IL-1R/TLR and TNFR pathways in renal tubular cells contributes to renal injury. This study aimed to investigate if blockade of lipopolysaccharide (LPS)-triggered TLR4 signalling by small interfering RNA (siRNA) targeting TRAF6 protects survival and inhibits inflammatory response in isolated rat renal proximal tubular cells (PTCs).

METHODS

PTCs isolated from F344 rat kidneys were transfected with chemically synthesized siRNA targeting TRAF6 mRNA. Real-time quantitative PCR was applied to measure mRNA level of TRAF6, TNF-alpha, IL-6 and monocyte chemoattractant protein-1 (MCP-1). Protein levels of extracellular signal-regulated kinase (ERK), c-jun N-terminal kinase (JNK), p38 mitogen-activated protein kinase, caspase 3 and cleaved caspase 3 were evaluated by Western blotting. Cell viability was analysed with XTT reagents.

RESULTS

We found that the TRAF6 gene was effectively silenced in PTCs using siRNA. TRAF6 knockdown resulted in reduced TNF-alpha and IL-6 mRNA expression upon LPS challenge. LPS-induced phosphorylation of JNK and p38 was attenuated in TRAF6 siRNA-transfected cells while the change in the phosphorylation of ERK was not remarkable. TRAF6 knockdown was associated with increased cell viability and reduced protein level of cleaved caspase-3, both, in the absence and presence of LPS.

CONCLUSION

Our studies suggest that TRAF6 knockdown may inhibit inflammatory response and promote cell survival upon LPS challenge in primary rat proximal renal tubular cells.

Peroxisome proliferator-activated receptor-gamma(PPARgamma) agonist improves coronary artery endothelial function in diabetic patients with coronary artery disease

The aim of this study was to assess the effect of rosiglitazone on endothelial function of the coronary arteries and on plasma levels of inflammatory markers in diabetic patients with coronary artery disease (CAD). Fifty-six patients with type 2 diabetes and CAD were randomized to receive either rosiglitazone (4 mg/day) or a control for 12 weeks. The coronary flow velocity reserve (CFVR) was assessed using transthoracic Doppler echocardiography at baseline and after 12 weeks. After 12 weeks of rosiglitazone treatment, plasma levels of C-reactive protein were significantly decreased and the median CFVR was significantly increased compared with baseline levels and compared with the control group. These results suggest that, in addition to its beneficial metabolic effects, rosiglitazone, via its anti-inflammatory effects, may improve endothelial function of the coronary arteries in patients with diabetes and CAD.

Landmark-wire technique of symptomatic subclavian artery occlusion

SUMMARY

The landmark at the opposite end of an occluded segment can be used for probing the occluded subclavian artery to be recanalized. Using this technique in three patients with symptomatic subclavian artery occlusion, we found the landmark-wire technique to be safe and effective for reopening completely occluded subclavian arteries. We also introduced a technique in which a protective device can be safely used throughout the stenting procedure.

Expression of clock genes Per1 and Bmal1 in total leukocytes in health and Parkinson's disease

BACKGROUND

There is a growing number of clinical studies that revealed a variety of behavioral and physiological desynchronies in patients with Parkinson's disease (PD). However, these desynchronies have not been defined at the molecular level.

METHODS

Using real-time RT-PCR assay, we analyzed the expression profiles of two principle clock genes, PER1 and BMAL1, in total leukocytes for 12 h during the evening, overnight and morning in subjects with PD and age/sex-matched healthy controls.

RESULTS

A difference in the expression pattern of BMAL1 but not PER1 was apparent during the dark span, where the relative abundance of BMAL1 was significantly lower in PD patients versus control subjects at 21:00, 00:00 and 06:00 h. Furthermore, expression levels of BMAL1 in PD patients correlated with their United Parkinson's Disease Rating Scale score at 06:00, 09:00 h, and with Pittsburgh Sleep Quality Index score at 06:00 h.

CONCLUSION

These results suggest that a peripheral molecular clock, as reflected in the dampened expression of the clock genes BMAL1 in total leukocytes, is altered in PD patients. In addition, the relative BMAL1 levels correlate positively with PD severity, which could provide a molecular basis to help monitor disease progression and response to investigational drugs.

Long pulse gastric electrical stimulation induces regeneration of myenteric plexus synaptic vesicles in diabetic rats

BACKGROUND

Gastric electrical stimulation (GES) may improve delayed gastric emptying in diabetic gastroparesis, but whether enteric nervous system (ENS) is directly involved in its mechanism of improvement in gastric motility is unclear. The aims were to investigate the correlation between the changes in ENS and effects of long pulse GES on them in diabetic rats induced by streptozotocin (STZ).

METHODS

Electron microscopy, immunohistochemistry, RT-PCR and western blot were used to evaluate changes of myenteric plexus neurons and synaptic vesicles in different stages of the diabetic rats. The effects of GES were detected by same methods after pacing wires were implanted and then diabetes was induced and followed by long pulse GES.

KEY RESULTS

Since 6 weeks after STZ injection, the nerve fibres were incompact and synaptic vesicles in myenteric neurons reduced. Furthermore, the myenteric neurons showed severe damage such as partial depletion of the axon, swelling of mitochondria and seriously decreased synaptic vesicles in 12 weeks after STZ injection. The synaptophysin and PGP9.5-positive area and expressions of synaptophysin mRNA and protein decreased with the duration of diabetes. Long pulse GES could induce increase of myenteric neuronal synaptic vesicles, synaptophysin and PGP9.5-positive area and in myenteric plexus. The synaptophysin mRNA and protein expression rose after GES, whatever GES beginning early or late, short-term or long-term.

CONCLUSIONS & INFERENCES

The longer duration of diabetes, the more significant damages to myenteric neurons and synaptic vesicles of diabetic rats; long pulse GES could induce regeneration of myenteric plexus synaptic vesicles, thereby reform gastric motility.