Sevoflurane preconditioning induces rapid ischemic tolerance against spinal cord ischemia/reperfusion through activation of extracellular signal-regulated kinase in rabbits

BACKGROUND

The protective effect of sevoflurane preconditioning against spinal cord ischemia/reperfusion (I/R) is unclear. We designed this study to investigate whether sevoflurane preconditioning could induce rapid ischemic tolerance to the spinal cord in a rabbit model of transient spinal cord ischemia and how the role of extracellular signal-regulated kinase (ERK) is involved.

METHODS

To test whether preconditioning with sevoflurane induces rapid ischemic tolerance, New Zealand White male rabbits were randomly assigned to three groups. Animals in the Sev group received preconditioning with 3.7% sevoflurane (1.0 minimum alveolar anesthetic concentration) in 96% oxygen for 30 min, whereas animals in the O(2) group serving as controls inhaled only 96% oxygen for 30 min. The Sham group received the same anesthesia and surgical preparation but no preconditioning or spinal cord I/R. To evaluate the role of ERK activation in sevoflurane preconditioning, rabbits were randomly assigned to four groups. U0126, an ERK inhibitor, was administered IV 20 min before the beginning of preconditioning in the U0126 + O(2) and U0126 + Sev groups. Dimethylsulfoxide was administered IV at the same time in the vehicle + O(2) and vehicle + Sev groups. At 1 h after preconditioning, the animals were subjected to spinal cord I/R induced by infrarenal aorta occlusion. All animals were assessed at 48 h after reperfusion with modified Tarlov criteria, and the spinal cord segments (L5) were harvested for histopathological examination, TUNEL staining, and Western blot of phosphor-ERK1/2.

RESULTS

The animals in the Sev group had higher neurological scores and more normal motor neurons than those in the O(2) group (P < 0.01 for each comparison). Compared with vehicle + Sev group, the U0126 + Sev group had worse neurological outcomes, fewer viable neurons, more apoptotic neurons, and significantly decreased ERK1/2 phosphorylation (P <or= 0.01 for each comparison). There were no significant differences in the outcomes among vehicle + O(2), U0126 + O(2), and U0126 + Sev groups.

CONCLUSIONS

This study demonstrates that sevoflurane preconditioning induces rapid tolerance to spinal cord I/R in rabbits, and the tolerance is possibly mediated through the activation of ERK. These data suggest that sevoflurane preconditioning might provide a new practical method for protecting perioperative spinal cord I/R.

SELDI-TOF-MS-based serum proteomic screening in combination with CT scan distinguishes renal cell carcinoma from benign renal tumors and healthy persons

In order to identify the proteomic differences between renal cell carcinoma (RCC) and benign renal tumors, we analyzed 168 serum samples from 65 RCC patients, 34 patients with benign renal tumors, and 69 healthy persons using the IMAC-Cu2+ ProteinChip system by surface enhanced laser desorption/ionization mass spectrometry technology. Two decision trees were generated by Biomarker Pattern software to distinguish between RCC versus healthy and RCC versus patients with benign tumors, respectively. Although the sensitivity and specificity of the RCC vs. healthy decision tree were 97.6% and 95.7%, respectively, it could not be used to distinguish RCC from benign renal tumors. The sensitivity of a blind test process using RCC, benign tumors and healthy persons were 92%. The specificity of the test process was 35.3% for benign tumors and 95.5% for healthy persons. The sensitivity and specificity of the RCC-Benign tumors decision tree were 85.7% and 95.5%, respectively. The blind test process using RCC, benign tumors and healthy persons also showed significant results. The sensitivity was 90.0%. The specificity was 95.7% for healthy persons and 90.0% for benign tumors. Combining these data with the results of CT scanning, the sensitivity can be improved over the use of either CT and decision tree analysis and the specificity may reach 100%. Two peaks with molecular masses of 3887.11 Da and 11079.8 Da were detected that are potentially useful for the diagnosis or screening of RCC. It was found that these two peaks can be used, not only to distinguish the RCC vs. healthy cases, but also to distinguish RCC from benign renal tumors. In combination with CT scanning, the sensitivity and specificity of the diagnosis of renal tumors can be improved. However, the decision tree constructed for RCC and healthy persons may not present good specificity for use in distinguishing malignant from benign renal tumors.

Using a minigene approach to characterize a novel splice site mutation in human F7 gene causing inherited factor VII deficiency in a Chinese pedigree

Factor VII deficiency which transmitted as an autosomal recessive disorder is a rare haemorrhagic condition. The aim of this study was to identify the molecular genetic defect and determine its functional consequences in a Chinese pedigree with FVII deficiency. The proband was diagnosed as inherited coagulation FVII deficiency by reduced plasma levels of FVII activity (4.4%) and antigen (38.5%). All nine exons and their flanking sequence of F7 gene were amplified by polymerase chain reaction (PCR) for the proband and the PCR products were directly sequenced. The compound heterozygous mutations of F7 (NM_000131.3) c.572-1G>A and F7 (NM_000131.3) c.1165T>G; p.Cys389Gly were identified in the proband's F7 gene. To investigate the splicing patterns associated with F7 c.572-1G>A, ectopic transcripts in leucocytes of the proband were analyzed. F7 minigenes, spanning from intron 4 to intron 7 and carrying either an A or a G at position -1 of intron 5, were constructed and transiently transfected into human embryonic kidney (HEK) 293T cells, followed by RT-PCR analysis. The aberrant transcripts from the F7 c.572-1G>A mutant allele were not detected by ectopic transcription study. Sequencing of the RT-PCR products from the mutant transfectant demonstrated the production of an erroneously spliced mRNA with exon 6 skipping, whereas a normal splicing occurred in the wide type transfectant. The aberrant mRNA produced from the F7 c.572-1G>A mutant allele is responsible for the factor VII deficiency in this pedigree.

Association of Ala589Ser polymorphism of WNK4 gene with essential hypertension in a high-risk Chinese population

Recent studies on the association between particular single nucleotide polymorphisms of serine-threonine kinase with no lysine (K) 4 gene (WNK4) and essential hypertension have yielded controversial results. Here, frequencies of Ala589Ser polymorphism within exon 8 of the WNK4 gene were assessed among 259 unrelated ethnic Chinese patients with essential hypertension and 235 strictly matched normotensive controls. All subjects were derived from a relatively isolated population identified in the Kerqin desert region in Zhangwu county of Liaoning, northeastern China, which features a dry climate and the people having a high dietary salt intake, in addition to a significantly higher prevalence (approximately 35%) of essential hypertension. Genotypes were verified with polymerase chain reaction-restriction fragment length polymorphism and confirmed by direct sequencing. Expression pattern and regulatory mechanisms of the WNK4 gene were also explored using Northern blotting and in vitro hormone stimulation assays. Strong associations between the Ala589Ser polymorphism and both raised systolic and diastolic blood pressures were identified. In addition to the kidneys, WNK4 gene expression was also found in many other organs. Several cis-acting elements had been discovered in the promoter region of the gene. As revealed by preliminary experiment, various hormones can down-regulate the expression of WNK4, among which glucocorticoid hormone seems to act in a dose-dependent manner. The WNK4 gene probably plays an important role in the pathogenesis of essential hypertension. As a missense mutation, the Ala589Ser polymorphism may bring changes to the enzyme's function(s), resulting in increased susceptibility to the disease.

REG1A predicts recurrence in stage Ta/T1 bladder cancer

AIMS

Stage Ta/T1 urothelial carcinoma of the bladder (Ta/T1 BC) has a marked tendency to recur. Regenerating protein 1 A (REG1A) has been reported to be expressed in human cancers, and it may be positively correlated with patient's prognosis. The aim of the present study was to evaluate the prognostic value of REG1A in Ta/T1 BC.

METHODS

Immunohistochemistry was done on 110 paraffin-embedded specimens of human Ta/T1 BC to detect the proteins REG1A, PCNA and MMP2. The relationships between REG1A expression and the clinical-pathological characteristics of Ta/T1 BC patients were evaluated.

RESULTS

Sixty-five out of 110 specimens were REG1A-positive. Grade and expression levels of MMP2 and REG1A were significantly correlated with the recurrence rate. REG1A expression (Hazard ratio: 3.1; 95% CI: 1.1-8.5; P=0.030) was an independent predictor of recurrence rate in multivariate Cox regression analysis. A significant association between REG1A expression and MMP2 expression (P=0.023) was also observed.

CONCLUSION

Expression of REG1A is an independent predictor of recurrence in Ta/T1 BC.

A novel mouse model of human breast cancer stem-like cells with high CD44+CD24-/lower phenotype metastasis to human bone

Abstract #4155

Background: At present, our understanding of the development of bone metastasis is limited. Therefore, little progress has been made in preventing skeletal metastasis in the breast cancer patient. A satisfactory animal model that avoids the species-specific factor and simultaneously shares similarities to the clinical pathophysiological progression of breast cancer metastasizing to bone is unavailable. A subpopulation (CD44+/CD24-/lower) of breast cancer cells possesses stem/progenitor cell properties (cancer stem-like cell). CD44 potentiates the adherence of metastatic breast cancer cells to bone marrow endothelial cells. In the present study, we used hepatocyte growth factor to enhance the proportion of CD44+/CD24-/lower subpopulation in the human breast cancer cell line MDA-MB-231. We used these human breast cancer stem-like cells and implantation of human bone to build a novel human-source model of human breast cancer skeletal metastasis.&#x2028; Methods: The human breast cancer cell line MDA-MB-231 was cultured in serum-free DMEM-F12 supplemented with growth factors. Cells in different subpopulations were separated by Percoll gradient centrifugation and incubated in the presence of 50 ng/mL hepatocyte growth factor. The proportion of CD44+/CD24-/lower subpopulation in the human breast cancer cell line MDA-MB-231 was detected with flow cytometry. Before injection with human breast cancer stem-like cells, the experimental animals were implanted with human bone in the right or left dorsal flanks. Animals in Groups A, B, and C were injected with 1 X 105, 1 X 106 human breast cancer stem-like cells, and 1 X 106 parental MDA-MB-231 cells, respectively. A positive control group (D) without implantation of human bone (non-human source model) was also injected with 1 X 106 MDA-MB-231 cells. A group of negative controls (E) with human bone implantation was injected with isotonic sodium chloride. For each group, Micro-SPECT was performed at weeks 4 and 7, and all animals were sacrificed at week 8. Immunohistochemistry was performed for CD34, CD105, SMA, CD44, CD24, CK, CXCR4, and OPN. mRNA levels of CD44, CD24, CXCR4, and OPN in bone metastasis tissues were analyzed by real-time quantitative polymerase chain reaction.&#x2028; Results: New vessels and connective tissue were found on the surface of implanted human bones and cells stained positive for antibodies against human CD105, SMA, and CD34, indicating that implanted human bones were viable and functional. Histologic and immunohistochemical analysis confirmed the metastases as cancer cells. Importantly, the results demonstrated that cells in implanted human bones of group B, which received 1 X 106 cancer stem-like cells, stained strongly positive for CD44, CXCR4, and OPN, whereas that of other groups showed no or minimum staining. Moreover, group B had the highest incidence of human bone metastasis (77.8%, P = 0.0230) and no accompaniment of other tissue metastasis. The real-time polymerase chain reaction (PCR) showed an increase of CD44 mRNA in metastatic bone tissues in group B compared with that of groups C and D (15.2- and 21.1-fold, respectively). The mRNA levels of CXCR4 and OPN (8.4- and 28.4-fold, respectively) in bone metastasis tissues of group B were all higher than that of groups C and D (4.8- and 11.6-fold; respectively). The levels of CD24 mRNA in group B were lowest, measuring only 30 percent of that in groups C and D.&#x2028; Conclusion: This study indicates that in the novel human source model of breast cancer, breast cancer stem-like cells demonstrate a higher human bone-seeking ability, which may contribute to increase metastasis incidence and attenuate species-specific influences. Its mechanism might be related to the higher expressions of CD44, CXCR4 and OPN, and the lower expression of CD24 in breast cancer stem-like cells. The model shares more similarities with clinical pathological features of bone metastatic patients. It will be helpful for further study of the mechanisms and subclinical diagnosis of bone metastasis.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 4155.

Angiotensinogen gene G-6A polymorphism influences idiopathic pulmonary fibrosis disease progression

Angiotensin II is a growth factor that plays a key role in the physiopathology of idiopathic pulmonary fibrosis (IPF). A nucleotide substitution of an adenine instead of a guanine (G-6A) in the proximal promoter region of angiotensinogen (AGT), the precursor of angiotensin II, has been associated with an increased gene transcription rate. In order to investigate whether the G-6A polymorphism of the AGT gene is associated with IPF development, severity and progression, the present study utilised a case-control study design and genotyped G-6A in 219 patients with IPF and 224 control subjects. The distribution of G-6A genotypes and alleles did not significantly differ between cases and controls. The G-6A polymorphism of the AGT gene was not associated with disease severity at diagnosis. The presence of the A allele was strongly associated with increased alveolar arterial oxygen tension difference during follow-up, after controlling for the confounding factors. Higher alveolar arterial oxygen tension changes over time were observed in patients with the AA genotype (0.37+/-0.7 mmHg (0.049+/-0.093 kPa) per month) compared to GA genotype (0.12+/-1 mmHg (0.016+/-0.133 kPa) per month) and GG genotype (0.2+/-0.6 mmHg (0.027+/-0.080 kPa) per month). G-6A polymorphism of the angiotensinogen gene is associated with idiopathic pulmonary fibrosis progression but not with disease predisposition. This polymorphism could have a predictive significance in idiopathic pulmonary fibrosis patients.

CD4+CD25high regulatory cells in peripheral blood of cancer patients

AIM

Regulatory T cells (Treg) that prevent autoimmune diseases by suppression of self-reactive T cells may also suppress the immune response against cancer. Experimental tumor models in mice revealed that Tregs are potent inhibitors of an antitumor immune response. The purpose of the study was to identify a CD4+ population of regulatory T cells expressing high levels of CD25(CD4+CD25 high) in the peripheral blood of cancer patients and provide the opportunity to determine whether cancer patients exhibit an expanded CD4+CD25high pool.

METHODS

The frequency of CD4+CD25high in the peripheral blood of 62 cancer patients and 15 healthy donors was determined by flow cytometry.

RESULTS

Compared with healthy donors, cancer patients have an increasing prevalence of CD4+CD25high T cells in the peripheral blood with characteristics of Tregs, i.e. they are CD45-RA(), CD69(-). Among patients, those with higher percentages of CD4+CD25high T cells had a poor prognosis than did those with lower percentages.

CONCLUSION

We provide evidence of an increased pool of CD4+CD25high in the peripheral blood of cancer patients, which may be related to immunosuppression and tumor progress in cancer patients. This finding suggests that the use of immunomodulatory therapy to treat cancer patients may be an effective strategy.

[Study on the controlling effect of Shenqi Fuzheng injection on plasma cytokine network in patients with thoracic tumor undergoing radiotherapy]

OBJECTIVE

To investigate the effect of Shenqi Fuzheng Injection (SFI) in radiation pneumonitis and its influence on the levels of plasma transforming growth factor beta (TGF-beta), tumor necrosis factor-alpha (TNF-alpha) and interleukin-10 (IL-10) at various stages (pre-, mid- and post-radiation) of radiotherapy (RT).

METHODS

Fifty-eight patients enrolled in this study were randomized into two groups, all received conventional radio therapy, but the treatment group was intravenously dripped with SFI additionally, once daily, starting 3 days before radiotherapy to 1 week after the end of it. Levels of TGF-beta, TNF-alpha and IL-10 in blood samples collected and frozen at different time point of RT, before radiotherapy (Pre-RT), after received 40-50 Gy radiation (Mid-RT) and in time of terminating RT (Post-RT), were measured with enzyme linked immunosorbent assay (ELISA). And the occurrence of radiation pneumonitis was analyzed according to RTOG acute radiation pneumonitis criteria.

RESULTS

Level of TGF-beta increased in both groups after RT, either Mid- or Post-RT, but in comparing with that at Pre-RT, statistical significant (P < 0.05) only showed in the control group at Post-RT time when it raised to peak, while in inter-group comparing insignificance was shown. Level of TNF-alpha also increased in both groups, but statistical significance only showed in the control groups as compared with that of Pre-RT, accordingly, it was lower in the treatment group than that in the control group at corresponding time points (P < 0.05). Level of IL-10 decreased gradually in the process of RT, as compared with that at Pre-RT, significant difference was shown in both groups at Post-RT but not at Mid-RT, as compared between groups, no significance (P < 0.05) was shown, though the treatment group showed a high tendency. As for the ratio of IL-10/TNF-alpha, significant difference of lowering in the control group after RT was shown as compared with that at Pre-RT (P < 0.05), and also as compared with that in the treatment group at corresponding time point (P < 0.05). The occurrence of radiation pneumonia > or = grade 2 in the treatment group was significantly lower than that in the control group (chi2 = 8.7133, P < 0.01).

CONCLUSION

Plasma level of TNF-alpha and ratio of IL-10/ TNF-a could be the practicable indexes for estimating the susceptibility of acute radiation pneumonia; SFI can regulate the network of cytokine, and thus be effective in preventing and treating radiation pneumonitis.

Apolipoprotein A-I stimulates AMP-activated protein kinase and improves glucose metabolism

AIMS/HYPOTHESIS

In humans, one of the hallmarks of type 2 diabetes is a reduced plasma concentration of HDL and its major protein component, apolipoprotein A-I (APOA-I). However, it is unknown whether APOA-I directly protects against diabetes. The aim of this study was to characterise the functional role of APOA-I in glucose homeostasis.

METHODS

The effects of APOA-I on phosphorylation of AMP-activated protein kinase (AMPK) and acetyl-coenzyme A carboxylase (ACC), glucose uptake and endocytosis were analysed in C2C12 myocytes. Glucose metabolism was investigated in Apoa-I knockout (Apoa-I (-/-)) mice.

RESULTS

APOA-I was able to stimulate the phosphorylation of AMPK and ACC, and elevated glucose uptake in C2C12 myocytes. APOA-I could be endocytosed into C2C12 myotubes through a clathrin-dependent endocytotic process. Inhibition of endocytosis abrogated APOA-I-stimulated AMPK phosphorylation. In Apoa-I (-/-) mice, AMPK phosphorylation was reduced in skeletal muscle and liver, and expression of gluconeogenic enzymes was increased in liver. In addition, the Apoa-I (-/-) mice had increased fat content and compromised glucose tolerance.

CONCLUSIONS/INTERPRETATION

Our data indicate that APOA-I has a protective effect against diabetes via activation of AMPK. ApoA-I deletion in the mouse led to increased fat mass and impaired glucose tolerance.

Cysteinyl leukotriene receptor 1 partially mediates brain cryoinjury in mice

AIM

To determine whether the cysteinyl leukotriene receptor 1 (CysLT1 receptor) modulates brain cryoinjury and whether the CysLT1 receptor antagonist pranlukast exerts a time-dependent protective effect on cryoinjury in mice.

METHODS

Brain cryoinjury was induced by applying a liquid nitrogen-cooled metal probe to the surface of the skull for 30 s. Brain lesion, neuron density, and endogenous IgG exudation were observed 24 h after cryoinjury. Transcription and the expression of the CysLT1 receptor were detected by RT-PCR and immunoblotting, and the localization of the receptor protein by double immunofluorescence.

RESULTS

The mRNA and protein expressions of the CysLT1 receptor were upregulated in the brain 6-24 h after cryoinjury, and the CysLT1 receptor protein was primarily localized in the neurons, not in the astrocytes or microglia. Pre-injury treatments with multi-doses and a single dose of pranlukast (0.1 mg/kg) attenuated cryoinjury; postinjury single dose (0.1 mg/kg) at 30 min (not 1 h) after cryoinjury was also effective.

CONCLUSION

The CysLT1 receptor modulates cryoinjury in mice at least partly, and postinjury treatment with its antagonist pranlukast exerts the protective effect with a therapeutic window of 30 min.

Cysteinyl leukotriene receptor 1 is involved in N-methyl-D-aspartate-mediated neuronal injury in mice

AIM

To determine whether cysteinyl leukotriene receptor 1 (CysLT1 receptor) is involved in N-methyl-D-aspartate (NMDA)-induced excitotoxic injury in the mouse brain.

METHODS

Brain injury was induced by NMDA microinjection (50-150 nmol in 0.5 microL) into the cerebral cortex. The changes in CysLT1 receptor expression 24 h after NMDA injection and the effects of a CysLT1 receptor antagonist, pranlukast (0.01 and 0.1 mg/kg), an NMDA receptor antagonist, ketamine (30 mg/kg), and an antioxidant, edaravone (9 mg/kg) were observed.

RESULTS

In the NMDA-injured brain, the CysLT1 receptor mRNA, and protein expression were upregulated, and the receptor was mainly localized in the neurons and not in the astrocytes. Pranlukast, ketamine and edaravone decreased NMDA-induced injury; pranlukast (0.1 mg/kg) and ketamine inhibited the upregulated expression of the CysLT1 receptor.

CONCLUSION

CysLT1 receptor expression in neurons is upregulated after NMDA injection, and NMDA-induced responses are inhibited by CysLT1 receptor antagonists, indicating that the increased CysLT1 receptor is involved in NMDA excitotoxicity.

CD4+CD25high regulatory cells in peripheral blood of NSCLC patients

The proportion and changes of CD4+CD25high regulatory T cells (Trs) in peripheral blood of non-small cell lung cancer (NSCLC) patients were analyzed and their clinical significance explored. The peripheral blood was collected from 61 patients with NSCLC and 15 healthy controls. By using monoclonal antibodies, the blood samples were evaluated with the flow cytometry for lymphocyte subsets (CD3+, CD4+ and CD8+) and CD4+CD25high Tr cells. The results showed that the proportion of CD4+CD25high Tr cells in NSCLC group was significantly higher than in control group [(4.36 +/-2.07) % vs (2.04+/-1.03) %, P<0.01]. The proportion of CD4+CD25 high Tr cells in late stage was higher than that in early stage [stages I +II (2.26+/-0.6) %; stage III (3.28+/-1.38) %; stage IV (6.06 +/-4.08) %] (P<0.05). Kaplan-Meier survival analysis revealed that the prognosis of the patients who had higher proportion of CD4+CD25high Tr cells in peripheral blood was worse (P=0.0026). In conclusion, the relative increase in CD4+CD25high Tr cells in peripheral blood may be related to immunosuppression and tumor progression in patients with NSCLC. This finding suggests that CD4+CD25+high Tr cells in peripheral blood of NSCLC may be positive for prognosis analysis. The use of depletion of the CD4+CD25high Tr cell therapy to treat NSCLC patients may be an effective strategy.

Leukotriene D4 induces brain edema and enhances CysLT2 receptor-mediated aquaporin 4 expression

Cysteinyl leukotrienes (including LTC(4), LTD(4), and LTE(4)), potent inflammatory mediators, can induce brain-blood barrier (BBB) disruption and brain edema. These reactions are mediated by their receptors, CysLT(1) and CysLT(2) receptors. On the other hand, aquaporin 4 (AQP4) primarily modulates brain water homeostasis and edema after various injuries. Here, we aimed to determine whether AQP4 is involved in LTD(4)-induced brain edema. LTD(4) (1ng in 0.5mul PBS) microinjection into the cortex increased endogenous IgG exudation (BBB disruption) and water content (brain edema), and enhanced AQP4 expression in mouse brain. The selective CysLT(1) receptor antagonist pranlukast inhibited the IgG exudation, but not the increased water content and AQP4 expression induced by LTD(4). In the cultured rat astrocytes, LTD(4) (10(-9)-10(-7)M, for 24h) similarly enhanced AQP4 expression. The enhanced AQP4 expression was inhibited by Bay u9773, a non-selective CysLT(1)/CysLT(2) receptor antagonist, but not by pranlukast. LTD(4) (10(-9)-10(-7)M) also induced the mRNA expression of CysLT(2) (not CysLT(1)) receptor in astrocytes. These results indicate that LTD(4) modulates brain edema; CysLT(1) receptor mediates vasogenic edema while CysLT(2) receptor may mediate cytotoxic edema via up-regulating AQP4 expression.

Evidence of increased oxidative damage in subjects with mild cognitive impairment

OBJECTIVE

To determine if increased levels of oxidative damage are present in the brains of persons with mild cognitive impairment (MCI), a condition that often precedes Alzheimer disease (AD).

METHODS

The authors assessed the amount of protein carbonyls, thiobarbituric acid-reactive substances (TBARS), and malondialdehyde in the superior and middle temporal gyri (SMTG) and cerebellum of short postmortem interval and longitudinally evaluated normal subjects and those with MCI and early AD.

RESULTS

Elevated levels of protein carbonyls (approximately 25%), malondialdehyde (approximately 60%), and TBARS (approximately 210%) were observed in the SMTG of individuals with MCI and early AD vs normal control subjects. The elevation in TBARS was associated with the numbers of neuritic but not diffuse plaques. Levels of protein carbonyls increased as delayed verbal memory performance declined.

CONCLUSION

Oxidative damage occurs in the brain of subjects with mild cognitive impairment, suggesting that oxidative damage may be one of the earliest events in the onset and progression of Alzheimer disease.

[CD4+ CD25high regulatory T cells in peripheral blood of patients with B cell non-Hodgkin's lymphoma]

This study was aimed to analyze the proportion of T cell subsets, CD4(+) CD25(high) regulating T cells (Tr) in peripheral blood of B-NHL patients and their change regularity, and to investigate the immunosuppression mechanism and influence of chemotherapy on immunosuppression function of B-NHL patients. The peripheral blood was collected from 42 patients with B-NHL, 36 patients with B-NHL who achieved partial remission (PR) or complete remission (CR) after 4 - 6 cycles of chemotherapy and 15 healthy controls. By using monoclonal antibodies, the blood samples were evaluated with the flow cytometry for lymphocyte subsets and Tr cells. The results showed that the proportion of CD3(+) and CD4(+) T cells, and the ratio of CD4/CD8 in patients with B-NHL group was significantly less than those in the healthy controls, i.e. (68.33 +/- 15.27)% versus (72.06 +/- 9.26)%; (34.47 +/- 12.84)% versus (42.45 +/- 9.2)%; 1.36 +/- 0.26 versus 1.92 +/- 0.20, but the prevalence of the CD4(+) CD25(high) Tr cells was significantly higher than those in the healthy group [(4.10 +/- 1.21)% versus (2.04 +/- 1.03)%, P < 0.001]. The ratio of CD4/CD8 in chemotherapy group was lower than that in control, but the proportion of CD4(+) CD25(high) Treg cells in chemotherapy group was higher than those before chemo-/radio-therapy and the control. It is concluded that the relative increase of CD4(+) CD25(high) Tr cells in peripheral blood of B-NHL patients may be related to immunosuppression and tumor progression.