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OBJECTIVE: To evaluate the protective effect of dexmedetomidine (Dex) against renal ischemia-reperfusion injury (RIRI) in rats through the phosphatidylinositol 3-hydroxy kinase (PI3K)/protein kinase B (Akt)/hypoxia-inducible factor-1α (HIF-1α) signaling pathway. MATERIALS AND METHODS: (1) A Sprague-Dawley rat model of RIRI was established. Thirty rats were divided into Sham group, injury (RIRI) group, and Dex treatment (RIRI + Dex) group. Serum was collected to detect renal function-related indexes, and the levels of serum inflammatory factors were examined via enzyme-linked immunosorbent assay (ELISA). (2) The kidney tissues were separated, and the degree of tissue damage was determined using immunohistochemical staining. (3) Ribonucleic acids (RNAs) were extracted from tissues, and the mRNA levels of inflammatory factors were measured using quantitative reverse transcription-polymerase chain reaction (qRT-PCR). (4) The protein expressions of Akt, phosphorylated (p)-Akt, PI3K, p-PI3K, and HIF-1α were detected via Western blotting. RESULTS: Compared with those in RIRI group, the levels of blood urea nitrogen and creatinine declined (p<0.05), the synthesized mRNAs of inflammatory factors in the kidney tissues were reduced (p<0.05), the secreted serum inflammatory factors was also reduced (p<0.05), and the phosphorylation levels of Akt and PI3K and the HIF-1α level rose (p<0.05) in RIRI + Dex group. CONCLUSIONS: Dex promotes the recovery of renal function and reduces the inflammatory level in RIRI rats through the PI3K/Akt/HIF-1α signaling pathway. [ABSTRACT FROM AUTHOR]

OBJECTIVE: The aim of this study was to explore the association between the expression of mitogen-activated protein kinase (MAPK)/extracellular regulated protein kinase (ERK) pathway and neuronal apoptosis in rats with white matter lesions (WML). MATERIALS AND METHODS: Sprague-Dawley (SD) rats were selected as the research objects. Rat models of ischemic WML were established by bilateral common carotid artery ligation. Subsequently, brain tissues were collected from rats in sham operation group and WML group, respectively. Hematoxylin-eosin (HE) staining assay was conducted to observe the pathological changes in white matters (WMs) (callosum, internal capsule, and optic nerve) and apoptotic cells in brain tissues. The protein expression levels of phosphorylated ERK (p-ERK) and ERK, phosphorylated MAPK (p-MAPK), and MAPK in tissues were measured by Western blotting. Immunohistochemistry was employed to detect the expression levels of p-ERK, ERK, p-MAPK, and MAPK in brain tissues of the two groups. Next, nerve cells were isolated from rats with WML as research objects. The phosphorylation of the MAPK/ERK pathway was suppressed using PD03259019 (a chemical drug, hereafter referred to as PD). Then, the changes in the protein expressions of apoptosis proteins B-cell lymphoma 2 (Bcl-2) and Bcl-2-associated X protein (Bax) were determined before and after MAPK/ERK pathway inhibition. Meanwhile, changes in the messenger ribonucleic acid (mRNA) expression levels were detected via real-time fluorescent quantitative polymerase chain reaction (PCR), and changes in apoptosis were observed. RESULTS: HE staining revealed that in sham operation group, WMs had normal structure and intact morphology. The cells were regularly arranged, with little apoptosis of the nuclei in the center. However, there were abnormally arranged nerve cells, loose cortical structure, swollen cells, aberrant nuclear membrane, pyknosis, signs of cell degeneration and necrosis, apoptotic cells filled most of the field of vision, and relatively evident lesions in WML group. Besides, WML group exhibited significantly up-regulated expressions of p-ERK and p-MAPK, as well as basically unchanged expressions of ERK and MAPK (p<0.05). After PD was added for 1 d, 2 d, and 3 d, the MAPK/ERK pathway was repressed, which was the most significantly at 3 d. Furthermore, the anti-apoptotic phenotype of neurons was detected, which was more pronounced at 3 d (p<0.05). CONCLUSIONS: Rats with WML exhibited elevated MAPK/ERK activity and evident apoptosis. After inhibiting the phosphorylation site of MAPK/ERK in rat neuronal cells, the expression of pro-apoptotic protein decreased, and the apoptosis was relieved. In rats with WML, neuronal apoptosis is promoted by activating the MAPK/ERK pathway, thus worsening the condition. [ABSTRACT FROM AUTHOR]

Surveys conducted in peanut production areas of China revealed peanut pod rot in several fields in Shandong and Hebei Provinces, China. A large quantity of an unknown stem nematode was isolated from the hulls and seeds of peanuts, herein described as Ditylenchus arachis n. sp. The new species is characterized by a combination of the following features: lateral lip sectors distinctly projected, stylet delicate, 8·4-10 µm in length, six lines in the lateral field, tail elongate-conoid, bursa covering about 68-86% of tail length. Pathogenicity tests showed that D. arachis n. sp. could infect peanut (Arachis hypogaea), but not sweet potato (Ipomoea batatas) or potato (Solanum tuberosum). Morphologically, D. arachis n. sp. appears closest to D. africanus, D. myceliophagus and D. destructor, but can be differentiated based upon a combination of morphological characteristics, host preference and molecular sequence data. The results of the phylogenetic analysis, based on 18S rDNA, the D2-D3 expansion region of 28S rDNA, and the ITS1-5·8S-ITS2 region, confirmed its status as a new species. A sister relationship with D. destructor was appointed, rather than with its ecologically very similar congener D. africanus. [ABSTRACT FROM AUTHOR]