Human exposure pathways of heavy metals in a lead-zinc mining area, Jiangsu Province, China.

Heavy metal pollution is becoming a serious issue in developing countries such as China, and the public is increasingly aware of its adverse health impacts in recent years. We assessed the potential health risks in a lead-zinc mining area and attempted to identify the key exposure pathways. We evaluated the spatial distributions of personal exposure using indigenous exposure factors and field monitoring results of water, soil, food, and indoor and outdoor air samples. The risks posed by 10 metals and the contribution of inhalation, ingestion and dermal contact pathways to these risks were estimated. Human hair samples were also analyzed to indicate the exposure level in the human body. Our results show that heavy metal pollution may pose high potential health risks to local residents, especially in the village closest to the mine (V1), mainly due to Pb, Cd and Hg. Correspondingly, the residents in V1 had higher Pb (8.14 mg/kg) levels in hair than those in the other two villages. Most of the estimated risks came from soil, the intake of self-produced vegetables and indoor air inhalation. This study highlights the importance of site-specific multipathway health risk assessments in studying heavy-metal exposures in China.

MRI measurement of angiogenesis and the therapeutic effect of acute marrow stromal cell administration on traumatic brain injury.

Using magnetic resonance imaging (MRI), the present study was undertaken to investigate the therapeutic effect of acute administration of human bone marrow stromal cells (hMSCs) on traumatic brain injury (TBI) and to measure the temporal profile of angiogenesis after the injury with or without cell intervention. Male Wistar rats (300 to 350 g, n=18) subjected to controlled cortical impact TBI were intravenously injected with 1 mL of saline (n=9) or hMSCs in suspension (n=9, 3 × 10(6) hMSCs) 6 hours after TBI. In-vivo MRI acquisitions of T2-weighted imaging, cerebral blood flow (CBF), three-dimensional (3D) gradient echo imaging, and blood-to-brain transfer constant (Ki) of contrast agent were performed on all animals 2 days after injury and weekly for 6 weeks. Sensorimotor function and spatial learning were evaluated. Volumetric changes in the trauma-induced brain lesion and the lateral ventricles were tracked and quantified using T2 maps, and hemodynamic alteration and blood-brain barrier permeability were monitored by CBF and Ki, respectively. Our data show that transplantation of hMSCs 6 hours after TBI leads to reduced cerebral atrophy, early and enhanced cerebral tissue perfusion and improved functional outcome compared with controls. The hMSC treatment increases angiogenesis in the injured brain, which may promote neurologic recovery after TBI.

Transplantation of marrow stromal cells restores cerebral blood flow and reduces cerebral atrophy in rats with traumatic brain injury: in vivo MRI study.

Cell therapy promotes brain remodeling and improves functional recovery after various central nervous system disorders, including traumatic brain injury (TBI). We tested the hypothesis that treatment of TBI with intravenous administration of human marrow stromal cells (hMSCs) provides therapeutic benefit in modifying hemodynamic and structural abnormalities, which are detectable by in vivo MRI. hMSCs were labeled with superparamagnetic iron oxide (SPIO) nanoparticles. Male Wistar rats (300-350 g, n=18) subjected to controlled cortical impact TBI were intravenously injected with 1 mL of saline (n=9) or hMSCs in suspension (n=9, approximately 3 × 10(6) SPIO-labeled hMSCs) 5 days post-TBI. In vivo MRI measurements consisting of cerebral blood flow (CBF), T2-weighted imaging, and 3D gradient echo imaging were performed for all animals 2 days post-TBI and weekly for 6 weeks. Functional outcome was evaluated with modified neurological severity score and Morris water maze test. Cell engraftment was detected in vivo by 3D MRI and confirmed by double staining. Ventricle and lesion volumetric alterations were measured using T2 maps, and hemodynamic abnormality was tracked by MRI CBF measurements. Our data demonstrate that treatment with hMSCs following TBI diminishes hemodynamic abnormalities by early restoration and preservation of CBF in the brain regions adjacent to and remote from the impact site, and reduces generalized cerebral atrophy, all of which may contribute to the observed improvement of functional outcome.