AIM:This study aimed to investigate the effect of ischemic post-conditioning(I-post-C)on lung ischemia-reperfusion injury(LIRI)in rats and relationship between I-post-C and zinc homeostasis.METHODS:SPF SD rats(6～8 weeks old)were randomly divided into four groups,with eight rats in each group:control group,ischemia/reper-fusion(I/R)group,I-post-C group and I-post-C+zinc ion chelator TPEN group.Inductively coupled plasma mass spec-trometry(ICP-MS)was used to measure the concentration of zinc ions in lung tissues.HE staining,lung wet/dry weight ra-tio(W/D),total lung water content(TLW),and index of quantitative assessment(IQA)of lung injury were used to detect the degree of lung tissue injury in each group.Mitochondrial membrane potential was measured using extraction and JC-1 mitochondrial membrane potential detection kits.TUNEL assay was used to detect the level of apoptosis in lung tissues.Western blot was used to detect the protein expression levels of caspase-3,solute carrier family 39 member 8(SLC39A8/ZIP8),solute carrier family 30 member 9(SLC30A9/ZNT9),and PI3K/AKT/GSK-3β in lung tissues of each group.RT-qPCR was used to detect ZIP8 and ZNT9.RESULTS:Compared to the control group,the I/R group showed significantly aggravated lung tissue injury(P<0.01),decreased zinc ion levels(P<0.01),enhanced cell apoptosis(P<0.05),re-duced mitochondrial membrane potential(P<0.01),decreased PI3K/AKT/GSK-3β phosphorylation levels(P<0.05,P<0.01),increased cleaved caspase-3/pro-caspase-3 ratio(P<0.01),and reduced ZIP8 expression(P<0.05).Compared to the I/R group,the I-post-C group exhibited alleviated injury(P<0.05 or P<0.01),increased zinc ion levels(P<0.01),reduced apoptosis(P<0.01),restored mitochondrial membrane potential(P<0.01),elevated PI3K/AKT/GSK-3β phosphorylation levels(P<0.05,P<0.01),decreased cleaved caspase-3/pro-caspase-3 ratio(P<0.05),and in-creased ZIP8 expression(P<0.05).Compared to the I-post-C group,the I-post-C+TPEN group demonstrated aggravated injury(P<0.01),decreased zinc ion levels(P<0.01),enhanced apoptosis(P<0.01),reduced mitochondrial membrane potential(P<0.05),decreased PI3K/AKT/GSK-3β phosphorylation levels(P<0.05,P<0.01),increased cleaved cas-pase-3/pro-caspase-3 ratio(P<0.05),and reduced ZIP8 expression(P<0.05).ZNT9 expression showed no significant differences among the groups(P>0.05).CONCLUSION:Ischemic postconditioning can improve LIRI by regulating zinc homeostasis,activating PI3K/AKT signaling pathway,inactivating glycogen synthase kinase 3β,inhibiting the de-cline of mitochondrial membrane potential,and antagonizing cell apoptosis in rats.

AIM:This study aimed to investigate the effect of ischemic post-conditioning(I-post-C)on lung ischemia-reperfusion injury(LIRI)in rats and relationship between I-post-C and zinc homeostasis.METHODS:SPF SD rats(6～8 weeks old)were randomly divided into four groups,with eight rats in each group:control group,ischemia/reper-fusion(I/R)group,I-post-C group and I-post-C+zinc ion chelator TPEN group.Inductively coupled plasma mass spec-trometry(ICP-MS)was used to measure the concentration of zinc ions in lung tissues.HE staining,lung wet/dry weight ra-tio(W/D),total lung water content(TLW),and index of quantitative assessment(IQA)of lung injury were used to detect the degree of lung tissue injury in each group.Mitochondrial membrane potential was measured using extraction and JC-1 mitochondrial membrane potential detection kits.TUNEL assay was used to detect the level of apoptosis in lung tissues.Western blot was used to detect the protein expression levels of caspase-3,solute carrier family 39 member 8(SLC39A8/ZIP8),solute carrier family 30 member 9(SLC30A9/ZNT9),and PI3K/AKT/GSK-3β in lung tissues of each group.RT-qPCR was used to detect ZIP8 and ZNT9.RESULTS:Compared to the control group,the I/R group showed significantly aggravated lung tissue injury(P<0.01),decreased zinc ion levels(P<0.01),enhanced cell apoptosis(P<0.05),re-duced mitochondrial membrane potential(P<0.01),decreased PI3K/AKT/GSK-3β phosphorylation levels(P<0.05,P<0.01),increased cleaved caspase-3/pro-caspase-3 ratio(P<0.01),and reduced ZIP8 expression(P<0.05).Compared to the I/R group,the I-post-C group exhibited alleviated injury(P<0.05 or P<0.01),increased zinc ion levels(P<0.01),reduced apoptosis(P<0.01),restored mitochondrial membrane potential(P<0.01),elevated PI3K/AKT/GSK-3β phosphorylation levels(P<0.05,P<0.01),decreased cleaved caspase-3/pro-caspase-3 ratio(P<0.05),and in-creased ZIP8 expression(P<0.05).Compared to the I-post-C group,the I-post-C+TPEN group demonstrated aggravated injury(P<0.01),decreased zinc ion levels(P<0.01),enhanced apoptosis(P<0.01),reduced mitochondrial membrane potential(P<0.05),decreased PI3K/AKT/GSK-3β phosphorylation levels(P<0.05,P<0.01),increased cleaved cas-pase-3/pro-caspase-3 ratio(P<0.05),and reduced ZIP8 expression(P<0.05).ZNT9 expression showed no significant differences among the groups(P>0.05).CONCLUSION:Ischemic postconditioning can improve LIRI by regulating zinc homeostasis,activating PI3K/AKT signaling pathway,inactivating glycogen synthase kinase 3β,inhibiting the de-cline of mitochondrial membrane potential,and antagonizing cell apoptosis in rats.

INTRODUCTIONThis study aimed to determine the stratified normative data by age and education for a modified version of the Mini-Mental State Examination (MMSE) test from a large sample of community-dwelling Chinese older adults in Singapore, and to examine the MMSE's value in detecting early cognitive impairment.

METHODSWe studied 1,763 Chinese older adults with normal cognitive function and 121 Chinese older adults with early cognitive impairment (Clinical Dementia Rating global score 0.5). Normative MMSE values were derived for each of the 15 strata classified by age (three groups) and education level (five groups). Receiver operating characteristic curve analysis was conducted for the whole sample and each of the three education subgroups (no education, primary, secondary and above).

RESULTSEducation level and age significantly influenced the normative values of MMSE total scores in Chinese older adults with normal cognitive function. For the purpose of detecting early cognitive impairment, an optimal balance between sensitivity (Se) and specificity (Sp) was obtained at a cutoff score of 25, 27 and 29 for each of the three education groups, respectively. For the whole sample, the optimal cutoff point was 26 (Se 0.61, Sp 0.84, area under curve 0.78).

CONCLUSIONAge and education level must be taken into account in the interpretation of optimal cutoffs for the MMSE. Although widely used, the MMSE has limited value in detecting early cognitive impairment; tests with better performance should be considered in clinical practice.

Age Factors ; Aged ; Area Under Curve ; China ; Cognition Disorders ; diagnosis ; epidemiology ; ethnology ; Dementia ; diagnosis ; epidemiology ; ethnology ; Educational Status ; Female ; Humans ; Male ; Mental Status Schedule ; Middle Aged ; Neuropsychological Tests ; standards ; Psychometrics ; methods ; Reference Values ; Sensitivity and Specificity ; Singapore ; ethnology

Phytic acid intake of preschool children was measured with modified ion exchange method. Zinc bioavailability was assessed by metabolic balance experiment and phytic acid/zinc molar ratio was calculated.The average intake of phytic acid in the diet was 499mg/day. The average of phytic acid/zinc molar ratio was 6.66. Even the subjects ingested foods rich in phytic acid, the phytic acid/zinc molar ratio (10.6) still remained at the lower limit of the critical value (10-20), that will inhibit zinc bioavailability. Metabolic balance study indicated that zinc bioavailability was not inhibited.Therefore, the phytic acid in present Chinese diet is unlikely a factor of zinc deficiency among children.