Mild Hypothermia Pretreatment Attenuates Liver Ischemia Reperfusion Injury Through Inhibiting c-Jun NH2-terminal Kinase Phosphorylation in Rats.

BACKGROUND: Mild hypothermia is known to be protected against ischemia reperfusion (IR) injury. But the exact mechanisms of protection have not yet been fully understood and its usage has been limited. Mild hypothermia pretreatment (MHP) is used to investigate the mechanisms of the protective effects against liver IR injury. METHODS: Anesthetized male Sprague-Dawley rats were randomly divided into five groups including the normal group (N), sham group (S), MHP group, normothermia pretreatment (NP) + IR group, and the MHP + IR group. In the pretreatment groups, mild hypothermia (32.2 ± 0.3°C) and normothermia (37 ± 0.5°C) pretreatment were applied for 2 hours, respectively. Then the IR groups suffered partial (70%) hepatic ischemia for 1 hour and reperfusion for 6 hours. At last, hepatic injury, apoptosis, and protein expression were assessed. RESULTS: Levels of serum alanine transaminase, hepatic injury, hepatocyte apoptosis, and c-Jun N-terminal kinase (JNK) phosphorylation were significantly higher in the IR groups. But when compared to NP, all these changes induced by IR were markedly attenuated by MHP. Serum alanine transaminase levels were 383.4 ± 13.1U/L in the MHP + IR group and 951.3 ± 39.4 U/L in the NP + IR group. The histologic score of liver injury in the MHP + IR group was 4.83 ± 1.17, whereas in the NP + IR group it was 10.5 ± 1.05. The proportion of apoptotic cells in the MHP + IR group was 11.58 ± 0.60, but in the NP + IR group, it was 44.95 ± 1.61. The phosphorylation of JNK was also significantly reduced in the MHP + IR group. All these differences are statistically significant (P < .05). CONCLUSIONS: MHP could markedly reduce liver IR injury, and these protective effects may be mainly exerted via inhibition of JNK phosphorylation.

[Cloning and identification of a new telomeric-associated zinc finger protein cDNA].

In order to isolate novel genes related to early human embryo development and differentiation, a directional cDNA library was constructed from 3-week-old human embryo. Single-pass DNA sequence analysis was used to sequence 47 randomly picked low-abundance cDNA clones. This approach led us to select a clone, L30, showing significant homology with the telomeric-associated DNA and zinc finger protein genes. It is about 3.8 kb in length and contains an open reading frame of notable length within 5'-region, and a tailing signal of AAUAAA and poly (A+) with 39 A in 3'-region. The gene was transcribed in human embryo by Northern blot hybridization and assigned to human chromosome 12 by in situ hybridization.

Polymorphism and genetic relatedness among wild and cultivated rice species determined by AP-PCR analysis.

We have applied the arbitrarily primed polymerase chain reaction (AP-PCR) technique to the analysis of the relationships among six japonica and indica cultivars, and four wild species of rice. Chosen were four primers of arbitrary sequence that gave multiple amplification products when rice DNA was used as template. Among a total of 50 bands scored, 44 were polymorphic, which was sufficient to distinguish the species used in this study. It is apparent from the comparisons of genetic distances that cultivated rice (Oryza sativa) exhibits closest molecular affinity to wild O. rufipogon, suggesting that the origin of cultivated rice is from O. rufipogon. In a dendrogram of cultivated rice and O. rufipogon from different regions, japonica and indica rice were most closely clustered with O. rufipogon from China and India, respectively. Japonica and indica subspecies showed closer affinity with O. rufipogon from different origins than with each other, supporting a hypothesis of multi-centers of the origin of rice cultivation.