Developmental Lead Exposure Alters the Distribution of Protein Kinase C Activity in the Rat Hippocampus

Chronic low-level lead (Pb) exposure in children is known to cause a deficit in learning and memory. In vitro studies have demonstrated that Pb altered protein kinase C (PKC) activityt Especially, hippocampal PKC has been correlated with performance in several learning tasks. The effects of Pb exposure on hippocampal PKC were investigated during development at various postnatal ages: postnatal day (PN) 7, 14, 28, and 56. Two-tenth % Pb acetate was administered to pregnant and lactating dams and then administered to weanling rats in drinking water. PKC activity was measured in both membrane and cytosolic fractions from the hippocampi of the controls and Pb-exposed animals. Pb-induced increase in PKC activity in the cytosolic fraction was obsereved in the PN56 rats. In contrast, PKC activity was decreased by Pb at PN7 in the membrane fraction. Furthermore, a significant decrease in the ratio of membrane to cytosolic PKC activity which is representative of PKC distribution was observed in the PN28 and PN56 Pb-exposed rats relative to the same-age controls. This study indicates that chronic Pb exposure during development influences hippocampal PKC activity and distribution. These changes may be involved in the subclinical neurotoxicity of chronic Pb exposure in young children.

Expression of altered retinoblastoma protein inversely correlates with tumor invasion in gastric carcinoma

AIM: To investigate the clinical and pathological significance of altered retinoblastoma (Rb) encoding protein (pRb) in gastric carcinoma. METHODS: Expression of altered pRb was analyzed in 91 patients with gastric adenocarcinoma by immunohistochemistry. RESULTS: Sixty-five percent (59/91) of the tumors were positively stained and the staining in tumor nuclei of gastric carcinoma ranged 0%-90%. Moreover, strong expression of altered pRb was found in 35% (6/17), 24% (5/21), 17% (8/46) and 0% (0/7) of T1, T2, T3 and T4 gastric carcinomas, respectively. altered pRb expression was inversely correlated with the depth of tumor invasion (P = 0.047). Degree of immunoreactivity had no significant correlation with tumor grade, node metastasis and distant metastasis. In terms of prognostic significance, univariate analysis showed that poor differentiation [41 (66.1%) vs 34 (42.5%) P = 0.051], advanced tumor stage (P < 0.001) and weakly altered pRb expression [17 (80.5%) vs 58 (49.6%) P = 0.044] were associated with worse prognosis in these patients. However, multivariate analysis revealed that advanced tumor stage was the only independent poor prognostic factor (P < 0.001). CONCLUSION: The mutation of Rb gene is frequent in gastric carcinoma. The expression of altered pRb inversely correlates with tumor invasion and is not an independent prognostic marker in gastric adenocarcinoma.

Acrylamide Alters Cytoskeletal Protein Level in Rat Serum

To study biomarker of acrylamide （ACR） induced neuropathy, Wistar rats received 20 or 40 mg/kg of ACR by ip injection and the levels of light neurofilament （NF-L）, middle NF （NF-M）, heavy NF （NF-H）, β-actin, α-tubulin, and β-tubulin proteins in serum were evaluated using both SDS-PAGE and Western blotting. Compared to controls, NF-L and NF-M decreased,

Altered Protein Profiling in Tears from Patients in a Traumatic Vegetative State

Following severe traumatic brain injury .（sTBI）, patients may remain in a coma, vegetative state （VS）, or minimally conscious state （MCS）, all of which are also clinically termed disorders of consciousness. Patients in a coma show complete disability in the arousal system and fail to achieve awareness spontaneously; yet true coma represents a transient state and rarely lasts longer than a month [1]. The VS （also known as unresponsive wakefulness syndrome）, characterized as a state with spontaneous or stimulus-induced eye-opening but the patient appears totally unaware of self and environment, may persist for months or years [2]. In contrast, the MCS is evidenced by preserved and reproducible signs of awareness as well as sleep-wake cycles, suggesting better recovery than coma and VS. Considering that no signs of consciousness are detectable, patients in a VS suffer from a high rate of misdiagnosis [3].