Reached Peak Value Research Articles

Characteristic transfer of colostrum-derived biologically active substances into cerebrospinal fluid via blood in natural suckling neonatal pigs.

The characteristic transfer of colostral components into cerebrospinal fluid (CSF) via serum after natural suckling has been studied by sodium dodecyl sulphate (SDS) electrophoresis, two-dimensional electrophoresis, immunoblot and enzyme linked immunosorbent assay methods in non-suckling pigs. Total protein concentrations in the serum increased immediately after first suckling, reached a peak value at 12 h, corresponding to a 2.3-fold compared with pre-suckling level. The protein concentration in CSF also increased and reached peak value at 6 h corresponding to 1.6-fold compared with presuckling level. IgG in serum not detected before suckling, increased steeply after suckling, IgG, IgM and IgA transported into the serum were observed in completely intact form by immunoblot method. The IgG transported into serum was quickly transferred into CSF after natural suckling in contrast to the case of bovine IgG. Serum concentration of transferrin was maintained at high level before suckling and was not changed by suckling. Transferrin also detected in CSF was not changed by suckling. Bovine lactoferrin (Lf) administered into the intestinal lumen was transported into serum (0.01%) and also detected in CSF after 6 h as undegraded form (3.1%). Thus, homologous IgG and bovine Lf are transported into CSF, suggesting that the transport of macromolecules into CSF is selective in neonatal pigs.

Role of p38 MAPK in ICAM-1 expression of vascular endothelial cells induced by lipopolysaccharide.

Lipopolysaccharide (LPS) stimulation of endothelial cells induces the expression of intercellular adhesion molecule-1 (ICAM-1), a critical adhesion molecule involved in the adhesive interaction between leukocytes and endothelial cells in shock and inflammation. Although there is little literature about role of p38 mitogen-activated protein kinase (MAPK) in ICAM-1 protein expression of LPS-induced endothelial cells, it is still not defined whether gene transcription is regulated by p38 MAPK in ICAM-1 expression of LPS-induced endothelial cells. In this study, the potential role of p38 MAPK in ICAM-1 expression of LPS-induced endothelial cells was studied in vitro and in vivo. In vitro studies, the results showed that compared with basic expression of ICAM-1 protein on cultured human umbilical vein endothelial cells (HUVECs), the ICAM-1 expression was increased initially at 2 h after LPS stimulation, reached peak value at 24 h, and descended at 36 h obviously. A dose-dependent relationship existed between LPS concentration and ICAM-1 expression. The abundance of ICAM-1 mRNA in cytoplasma of endothelial cells was upregulated significantly by LPS stimulation at 2 h and was maintained at a high level from 4 to 36 h. The upregulation of ICAM-1 protein and mRNA expression of LPS-induced HUVECs was markedly inhibited by SB203580 [4-(4-fluorophenyl)-2-(4-methylsulfinylphenyl)-5-(4-pyridyl)imidazole], a highly specific inhibitor of p38 MAPK. Activity of p38 MAPK in HUVECs was increased at 15 min after LPS stimulation and reached the maximum at 60 min, then descended significantly. Activity of p38 MAPK was inhibited significantly by SB203580 in vitro. In vivo studies, administration of SB203580 (12.5 or 25 mg/kg, per ora) markedly reduced LPS-induced expression of ICAM-1 protein and mRNA of lung tissues of male BALB/c mice. These data highlight that the upregulation of ICAM-1 expression of LPS-induced endothelial cells in vitro and in vivo is mediated by p38 MAPK pathway at the level of gene transcription. The ICAM-1 expression of LPS-induced endothelial cells is characteristic of time dependence and dose dependence, and tolerates to chronic LPS stimulation. Inhibition of the p38 MAPK signal pathway may be used as an approach to attenuate ICAM-1 production in the treatment of septic shock.

Clinical study on chronopharmacokinetics of digoxin in patients with congestive heart failure.

Fluorescence polarization immunoassay was used to study the chronopharmacokinetics of digoxin in 10 patients with congestive heart failure (CHF) who also served as self-controls. Our results showed that the serum digoxin concentration reached peak value 1 h after taking digoxin at 7:00 a.m., but the serum digoxin concentration reached the peak value 2 h after taking digoxin at 4:00 p.m. The average serum digoxin concentration area under curve was greater and the best maintainable time of serum concentration within 24 h after taking digoxin at 4 p.m. longer than those at 7:00 a.m. The heart rates were obviously lower and the cardiac function was significantly improved in 4:00 p.m. group.

Calcium channel in isolated outer hair cells of guinea pig cochlea

The physiological and pharmacological properties of the Ca 2+ channel in outer hair cells (OHCs) freshly isolated from guinea pig cochlea were investigated using a whole-cell patch-clamp technique. The Ca 2+ current ( I Ca) was activated from a membrane potential of −20 mV and reached peak value around +20 mV in external solution containing 20 mM Ca 2+ at a holding potential of −70 mV. The peak amplitude of I Ca increased in a hyperbolic manner with increasing extracellular Ca 2+ concentration. The ion selectively was Ba 2+ > > Ca 2+ ⩾Sr 2+. It was concluded that the Ca 2+ channel in OHCs of guinea pig is of the L-type.

日本人第三大臼歯中に蓄積された放射性核種および微量元素量に関する研究 Ｉ 生年１９００‐１９７０年の｀９０´Ｓｒ量の推移（１９８９年５月時点）

1) Strontium-90 level was determined in May 1989 in 40 sample groups of Japanese teeth, for a total of 1022 third molars, obtained from donors born in 1900-1970.2) The teeth from donors born in 1925-1931, and which were extracted in the donors' twenties did not contain detectable strontium-90.3) Strontium-90 level of the teeth from donors born in and after 1942 suddenly increased, and reached peak value of 62.8 to 72.8mBq/g Ca in 1953. It abruptly decreased after 1954 and reached approximately 20mBq/g Ca by 1970.4) In the teeth obtained from donors born in 1900-1924, and which were extracted at the age of 30 to 69, a small amount of strontium-90 was detected.

Protein kinase C in the regenerating rat liver

Protein kinase C (PKC) activity in the soluble fraction of regenerating rat liver showed a biphasic decrease prior to the initiation of DNA synthesis. The first decrease was seen at 3-6 h after partial hepatectomy (PH). The second decrease occurred after 14 h and continued until 24 h, while DNA synthesis began 18-20 h and reached peak value 22 h after PH. It is suggested that the soluble PKC in regenerating rat liver is activated and bound to the plasma membrane prior to the initiation of DNA synthesis.

Effect of tetrandrine on acute experimental myocardial infarction

In 19 anesthetized open-chest dogs the effects of tetrandrine on experimental myocardial infarction were investigated by epicardial mapping and creatine phosphate kinase (CPK) enzyme estimation. In epicardial mapping the ΣST and NST in dogs pretreated with tetrandrine were significantly lower than the control group after 15–30 minutes following ligation of the left anterior descending artery (LAD). The difference of ΣST, NST in both groups reached peak value at 2 hours. If taking the ΣST and NST 2 minutes after ligation as 100%), ΣST in the treated dogs 2 hours after ligation would be 43% vs 91% in the control group, NST in the treated dogs 53% vs 90% in the control group. 24 hours after ligation of LAD the CPK of preserved myocardium of infarcted area in the treated dogs was more than in the control group. The CPK released to blood was obviously less in treated group. These suggested that tetrandrine had some protective effects on experimental myocardial infarction. But because the number of dogs studied was small and the effect on clinical myocardial infarction might be different from experimental model, these observations warrant further investigation.

Responses of Young Calves to Low Doses of Lead

Twenty calves, week-old male Holsteins, 42.8 kg body weight, were assigned to four treatments by oral dose 0, 1.5, 3.0, and 6.0 mg lead carbonate/kg body weight given three times weekly until calf fetal hemoglobin had been converted to 100% adult hemoglobin for 2 consecutive wk. Analyses were for the first 7 wk when data were complete. Variables included lead in blood, body weight changes, erythrocyte delta-aminolevulinic acid dehydrase activity, packed cell volume, hemoglobin, conversion of fetal to adult hemoglobin, and erythrocyte 2,3-diphosphoglyceric acid. Early changes due to lead treatment were inhibition of delta-aminolevulinic acid dehydrase at all doses and increased loss of hemoglobin at 3.0 and 6.0 mg doses. Growth rate was not impaired seriously by lead treatment. The 2,3-diphosphoglyceric acid in erythrocytes reached peak value at 3 to 4 wk of age and then decreased with age, but 2,3-diphosphoglyceric acid of the treated calves was not changed by the low lead dosing. Low lead dosing will induce early metabolic changes in the young calf prior to inhibition of growth.