Traumatic axonal injury (TAI) plays a major role in the development of neurological impairments after traumatic brain injury (TBI), but it is commonly difficult to evaluate it precisely and early with conventional histological biomarkers, especially when the patients experience short-term survival after TBI. Diffusion tensor imaging (DTI) has shown some promise in detecting TAI, but longitudinal studies on the compromised white matter with DTI at early time points (≤72 h) following impact acceleration TBI are still absent. In the present study, rats were subjected to the Marmarou model and imaged with DTI at 3, 12, 24, and 72 h (n = 5 each) post-injury. Using a region-of-interest-based approach, the regions of interest including the corpus callosum, bilateral external capsule, internal capsule, and pyramidal tract were studied. Two DTI parameters, fraction anisotropy and axial diffusivity, were significantly reduced from 3 to 72 h in each region after trauma, corresponding to the gradient of axonal damage demonstrated by immunohistochemical staining of β-amyloid precursor protein and neurofilament light chain. Remarkably, DTI changes predicted the approximate time in the acute phase following TBI. These results indicate that the temporal profiles of diffusion parameters in DTI may be able to provide a tool for early diagnosis of TAI following impact acceleration TBI.

Thallium has been responsible for many intoxications since its discovery; however, toxicological profiles for thallium in human fatalities have not been updated recently. Autopsy, microscopic investigations, and toxicological analyses were performed on a married couple who died from thallium sulfate intended homicidal poisoning. The distribution of thallium was established by inductively coupled plasma mass spectrometry with hair samples showing the highest thallium concentration. Electron microscopy revealed a dystrophic condition of hair with disorganized cuticle and atrophy of the hair bulb. Thallium interacts with cells at different levels, with prominent ultrastructural injuries in the mitochondria and endoplasmic reticulum, and high concentration of electron dense granules observed in the cytoplasm and mitochondria of several organs. Alopecia, toxic encephalopathy, and peripheral neuropathy were diagnosed in the victims and suggested to be crucial implications for thallium poisoning. The analytical procedures used in this case are of considerable forensic importance in the diagnosis of thallium poisoning.

This study investigated the role of reactive oxygen species (ROS) in the pathogenesis of triptolide-induced renal injury in vivo. Rats were randomly divided into 4 groups (n=5 in each): triptolide group in which the rats were intraperitoneally injected with triptolide solution at a dose of 1 mg/kg of body weight on day 8; control group in which the rats received a single intraperitoneal injection of 0.9% physiological saline on day 8; vitamin C group in which the rats were pretreated with vitamin C by gavage at a dose of 250 mg/kg of body weight per day for 7 days before the same treatment as the control group on day 8; triptolide+vitamin C group in which the rats were first subjected to an oral administration of vitamin C at a dose of 250 mg/kg of body weight per day for 7 days, and then to the same treatment as the triptolide group on day 8. All the rats were sacrificed on day 10. Blood samples were collected for detection of plasma creatinine (Pcr) and plasma urea nitrogen (PUN) concentrations. Both kidneys were removed. The histological changes were measured by haematoxylin-eosin (HE) staining. The production of ROS was determined by detecting the fluorescent intensity of the oxidation-sensitive probe rhodamine 123 in renal tissue. Renal malondialdehyde (MDA) content was measured to evaluate lipid peroxidation level in renal tissue. TUNEL staining was performed to assess apoptosis of renal tubular cells. Renal expression of apoptosis-related proteins Bcl-2, Bax, Bid, Bad, Fas and FasL, as well as corresponding encoding genes were assessed by Western Blotting and real-time PCR. The results showed that triptolide treatment promoted the generation of a great amount of ROS, up-regulated the expression of Bax, Bid, Bad, Fas and FasL at both protein and mRNA levels, as well as the ratio of Bax to Bcl-2, and caused the apoptosis of renal tubular cells and renal injury. However, pretreatment with an antioxidant, vitamin C, significantly reduced the generation of ROS and effectively inhibited the triptolide-induced apoptosis of renal tubular cells and renal injury. It was concluded that ROS plays a critical role in triptolide-induced apoptosis of renal tubular cells and renal injury. The protective administration of vitamin C may help alleviate triptolide-induced renal injury and nephrotoxicity.

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