Associations Between Levels of Peripheral NCAPH2 Promoter Methylation and Different Stages of Alzheimer's Disease: A Cross-Sectional Study

BACKGROUND

Several studies have examined NCAPH2 methylation in amnestic mild cognitive impairment (aMCI) and Alzheimer's disease (AD), but little is known of NCAPH2 methylation in subjective cognitive decline (SCD).

OBJECTIVE

To examine whether methylation of peripheral NCAPH2 are differentially changed at various phases of AD, and whether it could serve as a diagnostic biomarker for SCD.

METHODS

A total of 40 AD patients, 52 aMCI patients, 148 SCD patients, and 193 cognitively normal controls (NCs) were recruited in the current case-control study. Besides, 54 cognitively normal individuals have received amyloid positron emission tomography (amyloid PET) scans. Using bisulfite pyrosequencing method, we measured blood DNA methylation in the NCAPH2 gene promoter.

RESULTS

The main outcomes were: 1) For SCD, there was no significant difference between SCD and NC regarding NCAPH2 methylation; 2) For aMCI, NCAPH2 methylation at CpG2 were significantly lower in aMCI compared with NC and SCD in the entire population and male subgroup; 3) For AD, NCAPH2 methylation at CpG1 were significantly lower in AD compared with NC among females; 4) A relationship with apolipoprotein E (APOE) ɛ4 status was shown. Receiver operating characteristic (ROC) analysis by combining NCAPH2 methylation, age, education, and APOEɛ4 status could distinguish between patients with aMCI (area under the curve (AUC): 0.742) and AD (AUC: 0.873) from NCs.

CONCLUSION

NCAPH2 methylation levels were altered at the aMCI and AD stage and may be convenient and cost-effective biomarkers of AD and aMCI.

Brain microglia activation and peripheral adaptive immunity in Parkinson's disease: a multimodal PET study

Background

Abnormal activation of immune system is an important pathogenesis of Parkinson’s disease, but the relationship between peripheral inflammation, central microglia activation and dopaminergic degeneration remains unclear.

Objectives

To evaluate the brain regional microglia activation and its relationship with clinical severity, dopaminergic presynaptic function, and peripheral inflammatory biomarkers related to adaptive immunity.

Methods

In this case–control study, we recruited 23 healthy participants and 24 participants with early-stage Parkinson’s disease. ¹⁸F-PBR06 PET/MR for microglia activation, ¹⁸F-FP-DTBZ for dopaminergic denervation, total account of T cells and subpopulations of T helper (Th1/Th2/Th17) cells, and the levels of serum inflammatory cytokines were assessed. Sanger sequencing was used to exclude the mix-affinity binders of ¹⁸F-PBR06-PET.

Results

Compared to healthy controls, patients with Parkinson’s disease had an increased ¹⁸F-PBR06-PET standardized uptake value ratio (SUVR) in the putamen, particularly in the ipsilateral side of the motor onset. ¹⁸F-PBR06-PET SUVR was positively associated with ¹⁸F-FP-DTBZ-PET SUVR in the brainstem and not associated with disease severity measured by Hoehn and Yahr stage, MDS-UPDRS III scores. Patients with Parkinson’s disease had elevated frequencies of Th1 cells and serum levels of IL10 and IL17A as compared to healthy controls. No significant association between peripheral inflammation markers and microglia activation in the brain of PD was observed.

Conclusion

Parkinson’s disease is associated with early putaminal microglial activation and peripheral phenotypic Th1 bias. Peripheral adaptive immunity might be involved in microglia activation in the process of neurodegeneration in PD indirectly, which may be a potential biomarker for the early detection and the target for immunomodulating therapy.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12974-022-02574-z.

β-Amyloid in blood neuronal-derived extracellular vesicles is elevated in cognitively normal adults at risk of Alzheimer's disease and predicts cerebral amyloidosis

Background

Blood biomarkers that can be used for preclinical Alzheimer’s disease (AD) diagnosis would enable trial enrollment at a time when the disease is potentially reversible. Here, we investigated plasma neuronal-derived extracellular vesicle (nEV) cargo in patients along the Alzheimer’s continuum, focusing on cognitively normal controls (NCs) with high brain β-amyloid (Aβ) loads (Aβ+).

Methods

The study was based on the Sino Longitudinal Study on Cognitive Decline project. We enrolled 246 participants, including 156 NCs, 45 amnestic mild cognitive impairment (aMCI) patients, and 45 AD dementia (ADD) patients. Brain Aβ loads were determined using positron emission tomography. NCs were classified into 84 Aβ− NCs and 72 Aβ+ NCs. Baseline plasma nEVs were isolated by immunoprecipitation with an anti-CD171 antibody. After verification, their cargos, including Aβ, tau phosphorylated at threonine 181, and neurofilament light, were quantified using a single-molecule array. Concentrations of these cargos were compared among the groups, and their receiver operating characteristic (ROC) curves were constructed. A subset of participants underwent follow-up cognitive assessment and magnetic resonance imaging. The relationships of nEV cargo levels with amyloid deposition, longitudinal changes in cognition, and brain regional volume were explored using correlation analysis. Additionally, 458 subjects in the project had previously undergone plasma Aβ quantification.

Results

Only nEV Aβ was included in the subsequent analysis. We focused on Aβ₄₂ in the current study. After normalization of nEVs, the levels of Aβ₄₂ were found to increase gradually across the cognitive continuum, with the lowest in the Aβ− NC group, an increase in the Aβ+ NC group, a further increase in the aMCI group, and the highest in the ADD group, contributing to their diagnoses (Aβ− NCs vs. Aβ+ NCs, area under the ROC curve values of 0.663; vs. aMCI, 0.857; vs. ADD, 0.957). Furthermore, nEV Aβ₄₂ was significantly correlated with amyloid deposition, as well as longitudinal changes in cognition and entorhinal volume. There were no differences in plasma Aβ levels among NCs, aMCI, and ADD individuals.

Conclusions

Our findings suggest the potential use of plasma nEV Aβ₄₂ levels in diagnosing AD-induced cognitive impairment and Aβ+ NCs. This biomarker reflects cortical amyloid deposition and predicts cognitive decline and entorhinal atrophy.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13195-022-01010-x.

[Analysis on the proportion of men who have sex with men and related factors among male over 15 years old in Kunming]

Objectives: To investigate the proportion of MSM among males over 15 years old and analyze its related factors to provide a reference for estimation of MSM size. Methods: Using cross-sectional survey design, multi-stage sampling method, and street interception survey method, a survey was conducted on males over 15 years old in Kunming from October to December 2019, with an estimated sample size of 9 908. Results: Totally, 10 707 males were recruited from 30 sites in 5 counties, and 10 283 were effectively surveyed with a response rate of 96.0%. Respondents aged 16 to 40 accounted for 75.3% (7 748), senior high school or above 71.1% (7 312), and unmarried 49.8% (5 121). The proportion of homosexual behavior in the past half-year was 1.06% (95%CI: 0.86%-1.26%), and the age-adjusted rate was 0.97% (95%CI: 0.78%-1.16%). And multivariate logistic regression showed the associated factors for homosexual behavior as following: proportion of main urban area was 2.217 times (95%CI:1.004-4.895) that of the outer suburbs, registered residence outside Kunming was 0.421 times (95%CI:0.260-0.682) that of in Kunming, having been in Kunming ≤6 months was 2.282 times (95%CI:1.262-4.126) that of >6 months, senior middle school or above was 0.336 times (95%CI:0.228-0.495) that of junior middle school and below, and being married was 0.462 times (95%CI:0.303-0.705) that of unmarried. Conclusions: The proportion of over 15-year-old males who have recently practiced male-male behavior was close to 1.00% in Kunming. The relevant factors included survey areas with a permanent residency of Kumming, short-time residency, education level, and marital status. This study obtained the data and related factors, which provided a reference for estimating MSM size in Yunnan province.

[Fibrosis-driving cells in patients with primary myelofibrosis and myelodysplastic syndromes with myelofibrosis]

Objective: To compare fibrosis-driving cells in patients with primary myelofibrosis (PMF) and patients with myelodysplastic syndromes (MDS) with myelofibrosis (MF) (MDS-MF) . Methods: Bone marrow biopsy sections of patients with newly diagnosed PMF and MDS (10 each randomly selected for MF-0/1, MF-2, and MF-3) were stained with specific immunofluorescence antibodies to label Gli1, LeptinR, alpha smooth muscle actin (α-SMA) , CD45, and ProcollagenⅠ. Images captured by confocal microscopy were analyzed by Fiji-ImageJ to calculate the cell counts of Gli1(+), LeptinR(+) cells, and fibrosis-driving cells including α-SMA(+), α-SMA(+)/Gli1(+), α-SMA(+)/LeptinR(+), and ProcollagenⅠ(+)/CD45(+) cells. Results: Patients with PMF and MDS with MF-2/3 had higher LeptinR(+), α-SMA(+), α-SMA(+)/Gli1(+), and Procollagen Ⅰ(+)/CD45(+) cell counts compared with those with MF-0/1 (all P values<0.05) . However, patients with PMF with MF-2/3 presented with higher Gli1(+) and α-SMA(+)/LeptinR(+) cell counts than those with MF-0/1 (P=0.001 and 0.006) , whereas these cells were similar between patients with MDS with MF-0/1 and MF-2/3 (P=0.169 and 0.067) . In patients with MF-0/1, all fibrosis-driving cells did not differ between PMF and MDS (all P>0.05) . However, in patients with MF-2/3, Procollagen Ⅰ(+)/CD45(+) cell counts were higher in patients with PMF compared with those with MDS (P=0.007) , while other fibrosis-driving cell counts were similar between these two groups (all P>0.05) . MF grade and fibrosis-driving cell counts were not correlated with overall survival in patients with either PMF or MDS. Conclusion: α-SMA(+) cells in patients with PMF originated from both Gli1(+) and LeptinR(+) cells, whereas α-SMA(+) cells in patients with MDS-MF only originated from Gli1(+) cells; patients with PMF had higher ProcollagenⅠ(+)/CD45(+) cell counts than those with MDS-MF.

Blood NCAPH2 Methylation Is Associated With Hippocampal Volume in Subjective Cognitive Decline With Apolipoprotein E ε4 Non-carriers

Objective: This study assessed the methylation of peripheral NCAPH2 in individuals with subjective cognitive decline (SCD), identified its correlation with the hippocampal volume, and explored whether the correlation is influenced by apolipoprotein E ε4 (APOE ε4) status.

Methods: Cognitively normal controls (NCs, n = 56), individuals with SCD (n = 81), and patients with objective cognitive impairment (OCI, n = 51) were included from the Sino Longitudinal Study on Cognitive Decline (NCT03370744). All participants completed neuropsychological assessments, blood tests, and structural MRI. NCAPH2 methylation was compared according to the diagnostic and APOE ε4 status. Partial correlation analysis was conducted to assess the correlations between the hippocampal volume, cognitive tests, and the NCAPH2 methylation levels.

Results: Individuals with SCD and patients with OCI showed significantly lower levels of NCAPH2 methylation than NCs, which were independent of the APOE ε4 status. The NCAPH2 methylation levels and the hippocampal volumes were positively correlated in the SCD APOE ε4 non-carriers but not in the OCI group. No association was found between the NCAPH2 methylation levels and the cognitive function.

Conclusion: Abnormal changes in blood NCAPH2 methylation were found to occur in SCD, indicating its potential to be used as a useful peripheral biomarker in the early stage of Alzheimer's disease screening.

[Features and clinical significance of gene mutations in patients with myelodysplastic syndromes with ring sideroblasts]

Objective: To explore the features and clinical significance of gene mutations in patients with myelodysplastic syndromes with ring sideroblasts (MDS-RS) . Methods: A total of 255 newly diagnosed primary MDS-RS patients were retrospectively reviewed from our center from January2001 to June 2019. SF3B1 gene mutations were detected by Sanger sequencing in 129 patients, and next generation sequencing (NGS) was performed in the other 126 patients using a set of selected 112-genes. Results: A total of 193 (75.7%) patients presented with SF3B1 mutation, predominantly mutant at amino acid position 700 (K700E) (n=147, 76.2%) . Non-SF3B1 gene mutations were TET2 (16.7%) , ASXL1 (14.3%) , U2AF1 (11.1%) , TP53 (7.9%) , SETBP1 (6.3%) , and RUNX1 (6.3%) . RS 5%-<15% patients had a higher SETBP1 mutation frequency than RS≥15% patients (21.4% vs 4.5%, P=0.044) . Mutation frequencies of other genes were similar in both groups (all P>0.05) . SF3B1 variant allele frequencies (VAF) had positive correlation with marrow RS percentage but without statistical significance in RS 5%-<15% group (P=0.078, r=0.486) . SF3B1 mutant patients presented with higher marrow RS percentage compared with wild-type patients[40.0% (15.0%-80.0%) vs 25.5% (15.0%-82.0%) , P<0.001], and SF3B1 VAF positively correlated with RS percentage (P=0.009, rs=0.261) in RS≥15% group. Age, ANC, PLT, mean RBC corpuscular volume, RS percentage, IPSS-R cytogenetics, and IPSS-R risk score were significantly different between patients with SF3B1 mutations and wild-type SF3B1 (all P<0.05) . Multivariable survival analyses adjusted by age and IPSS-R cytogenetics revealed that SF3B1 mutation was an independent favorable prognostic factor (HR=0.265, 95% CI 0.077-0.917, P=0.036) , and TP53 mutation was an adverse variable independent of SF3B1 mutation (HR=6.272, 95% CI 1.725-22.809, P=0.005) . According to the mutant status of SF3B1 and TP53, MDS-RS patients were categorized into 4 groups, namely, with SF3B1 and TP53 mutation, with wild-type SF3B1 and TP53, with wild-type SF3B1 but TP53 mutation, and with SF3B1 mutation but wild-type TP53. There was a significant difference for OS among these 4 groups (P<0.001) . The former 3 groups showed no significant difference in OS in multiple comparisons. However, the SF3B1 mutation but wild-type TP53 group had a better OS than wild-type SF3B1 but TP53 mutation group and wild-type SF3B1 and TP53 group, whereas a similar OS compared with SF3B1 and TP53 mutation group. Conclusion: SF3B1 mutations were prevalent in MDS-RS patients with the most common mutation at amino acid position 700 (K700E) . SF3B1 mutation was an independent favorable prognostic variable, whereas TP53 mutation was an independent adverse variable. SF3B1 mutation could coordinate with TP53 mutation for more sophisticated prognosis stratification in MDS-RS patients.

Population Structure and Genetic Diversity of Fungi Causing Rice Seedling Blight in Northeast China Based on Microsatellite Markers

Rice seedling blight, which is caused by diverse pathogenic microorganisms, occurs worldwide and is the most important seedling disease affecting rice production in Northeast China. To further characterize the population structure and genetic diversity of the fungi responsible for rice seedling blight in Northeast China, 225 fungal strains were isolated from diseased rice seedlings collected from various rice-producing areas. The isolated strains included Fusarium oxysporum (48.0%), F. verticillioides (11.6%), F. tricinctum (8.0%), F. redolens (6.7%), F. equiseti (6.2%), F. solani (6.2%), Rhizoctonia solani (6.7%), Alternaria alternata (4.0%), and Curvularia coatesiae (2.7%). F. oxysporum was the dominant fungal species causing rice seedling blight, with most isolates exhibiting moderate pathogenicity. Moreover, to our knowledge, this is the first study to identify A. alternata and C. coatesiae as causal agents of rice seedling blight in Northeast China. None of the F. oxysporum isolates were sensitive to 10 μg/ml of carbendazim, implying that carbendazim is ineffective for controlling rice seedling blight in Northeast China. The F. oxysporum isolates were divided into nine groups based on a simple sequence repeat analysis involving 14 primer pairs. In addition, an analysis of molecular variance revealed a significant correlation between the F. oxysporum population and geographical location, which had a significant effect on the differentiation of the dominant isolate population. The results of this study provide insights into the genetic diversity of F. oxysporum strains causing rice seedling blight and may be useful for selecting isolates to screen for disease-resistant rice varieties, evaluating fungicide efficacy, and developing effective disease management strategies.

[Mean corpuscular volume ≤100 fl was an independent prognostic factor in patients with myelodysplastic syndrome and bone marrow blast<5 percent]

目的

探讨平均红细胞体积（MCV）对骨髓增生异常综合征（MDS）预后的影响。

方法

收集2009年12月至2017年12月我中心新诊断、无红细胞输注史的321例原发性MDS患者，回顾性分析MCV水平对整体及不同骨髓原始细胞水平患者总生存（OS）期的影响。

结果

全部患者按照MCV水平高低分为MCV≤100 fl组（148例）和MCV>100 fl组（173例）。MCV≤100 fl组患者中位OS时间为27（95%CI 19~35）个月，MCV>100 fl组患者中位OS时间为72（95%CI 5~139）个月，差异有统计学意义（P<0.001）。亚组分析示，在骨髓原始细胞<5%的患者中，MCV≤100 fl患者的中位OS期较MCV>100 fl者显著缩短（P=0.002）；而在骨髓原始细胞≥5%的患者中，MCV水平对OS的影响不显著（P=0.078）。在纳入其余临床指标及基因突变校正后，MCV≤100 fl仍为骨髓原始细胞<5%患者的独立不良预后因素（HR=1.890，95%CI 1.007~3.548，P=0.048）。对不同MCV水平骨髓原始细胞<5%的MDS患者的临床及实验室指标进行分析，结果显示MCV≤100 fl组患者外周血HGB高于MCV>100 fl组[90（42~153）g/L对78.5（28~146）g/L，P=0.015]，IPSS-R高危/极高危组比例及IPSS-R染色体核型分组差/很差比例明显高于MCV>100 fl组，差异有统计学意义（28.8%对10.8%，P=0.003；24.7%对12.9%，P=0.049）。MCV≤100 fl组患者平均基因突变数目较MCV>100 fl组多（0.988个对0.769个，P=0.064），SF3B1突变较MCV>100 fl组少见（4.7%对15.4%，P=0.018）。

结论

MCV≤100 fl为骨髓原始细胞<5%的MDS患者独立于基因突变及其他临床指标的预后不良因素。

[The anti-proliferative and anti-inflammatory mechanisms of JAK1 inhibitor SHR0302 versus Ruxolitinib in SET2 cell line and primary cells]

目的

探究选择性JAK1抑制剂SHR0302和芦可替尼对骨髓增殖性肿瘤（MPN）细胞株SET2细胞和MPN患者原代细胞的影响以及分子作用机制。

方法

CCK8法检测不同浓度SHR0302和芦可替尼对SET2细胞增殖能力的影响；集落形成实验检测SHR0302和芦可替尼对MPN患者原代细胞红系爆式集落形成单位（BFU-E）的作用；多因子检测试剂盒MSD检测SHR0302和芦可替尼对SET2细胞IL-6、TNF-α、IL-1β、IL-2、IL-8、IL-12p70蛋白表达水平的影响；以Western blot法检测SHR0302和芦可替尼对SET2细胞JAK-STAT信号通路分子磷酸化水平的影响。

结果

0.1、1.0、2.5、5.0 µmol/L SHR0302作用SET2细胞24、48、72 h，细胞增殖抑制率随药物浓度的增大而增高（P< 0.001）；0.01、0.05、0.10 µmol/L芦可替尼作用SET2细胞48、72 h，细胞增殖抑制率亦随药物浓度的增大而增高（P<0.001），且均在72 h抑制作用最显著。2.5 µmol/L SHR0302、0.1 µmol/L芦可替尼作用SET2细胞72 h，细胞增殖抑制率分别为（59.94±0.60）％、（64.00±0.66）％，提示SHR0302的增殖抑制作用弱于芦可替尼。与对照组比较，0.1、1.0、5.0 µmol/L SHR0302和0.1、0.2、0.4 µmol/L芦可替尼均浓度依赖性地抑制MPN患者BFU-E形成，1.0 µmol/L SHR0302对MPN患者BFU-E集落形成抑制程度与0.2 µmol/L芦可替尼相当。除IL-12外，1.6 µmol/L SHR0302作用SET2细胞24 h可明显抑制炎性介质蛋白IL-6、TNF-α、IL-1β、IL-2、IL-8表达（P<0.01），与1.0 µmol/L芦可替尼对炎性介质抑制作用相当。不同浓度SHR0302作用SET2细胞3 h后JAK-STAT信号通路显著抑制，在1.0 µmol/L时可显著抑制p-STAT1（Tyr701）、p-STAT3（Tyr705）蛋白磷酸化，在5.0 µmol/L时可使p-JAK1（Tyr1022/1023）、p-STAT5（Tyr694）蛋白磷酸化水平明显下调（P<0.05），而芦可替尼在0.1 µmol/L即可明显抑制下游STAT蛋白磷酸化水平。

结论

SHR0302能有效抑制MPN细胞株和患者原代细胞的增殖以及炎性因子表达，其机制可能与下调p-JAK1及其下游p-STAT1、p-STAT3、p-STAT5蛋白磷酸化水平相关，但其抗增殖、抗炎作用弱于芦可替尼。

[Spatial-temporal cluster of hemorrhagic fever with renal syndrome in Hebei province, 2005-2016]

Objective: To explore the spatial-temporal distribution and epidemic characteristics of hemorrhagic fever with renal syndrome (HFRS) in Hebei province from 2005 to 2016. Methods: Records of HFRS cases reported from each county in Hebei during January 2005 to December 2016 were collected from National Notifiable Disease Surveillance System (NNDSS). Global and local spatial association statistics were used to measure the spatial autocorrelation and software GeoDa 1.2.0. Software SaTScan 9.4.1 was used to analyze spatiotemporal clusters. Software ArcGIS 10.2 was used to visualize the yearly scan results. Results: In Hebei province, a total of 8 437 human HFRS cases reported from 170 counties with an annual incidence rate of 0.99/100 000 population during 2005-2016. The peak incidence season was spring. Global spatial autocorrelation analysis on the incidence of HFRS at county-level showed that the value of Moran's I were all above 0 (P<0.05), indicating that the significant spatial cluster. The result of local indicators on spatial association (LISA) analysis revealed that identified hot spots were mainly in northeastern area, while cold spots were found in some counties of central and southern areas. Spatial-temporal scan detected that the primary cluster of HFRS incidence was mainly distributed in Qinhuangdao city and Tangshan city, including 11 counties (city/district): Beidaihe district, Haigang district, Funing district, Shanhaiguan district, Changli county, Lulong county and Qinglong Manchu autonomous county in Qinhuangdao city, and Qian'an city, Laoting county, Luanzhou city and Luannan county in Tangshan city (RR=39.64, P<0.001), during January-July in 2005. Conclusions: There were significant spatial-temporal cluster of HFRS in Hebei from 2005 to 2016. The cluster areas of HFRS were mainly in northeastern Hebei, it is necessary to strengthen the prevention and control programs of HFRS in these areas.

[Clinical implications and prognostic value of TP53 gene mutation and deletion in patients with myelodysplastic syndromes]

目的

探讨伴TP53基因异常骨髓增生异常综合征（MDS）患者的临床特征及预后。

方法

回顾性分析2009年10月至2017年12月中国医学科学院血液病医院新诊断的584例原发性MDS患者临床资料，采用包含112个血液肿瘤相关基因的靶向测序技术进行突变分析，并采用间期荧光原位杂交（FISH）技术检测TP53基因缺失。分析TP53基因突变和（或）缺失与临床特征之间的关系及其对患者总生存（OS）的影响。

结果

42例（7.2%）伴TP53基因异常，其中单纯基因突变31例（5.3%），单纯基因缺失8例（1.4%），同时伴有突变和缺失3例（0.5%）。34例伴TP53基因突变患者中共检测到37个TP53突变，其中35个位于DNA结合结构域（第5~8号外显子），1个位于第10号外显子，1个为剪切位点突变。伴TP53基因异常组的平均基因突变数目（2.52个）显著高于无异常组（1.96个）（z=−2.418，P=0.016）。伴TP53基因异常患者的中位年龄[60（21~78）岁]高于无异常患者[52（14~83）岁]（z=−2.188，P=0.029）；伴TP53基因异常组中复杂核型比例、IPSS较高危组（中危-2及高危）比例显著高于无异常组（P值均<0.001）。伴TP53基因异常组的中位OS期[13（95%CI 7.57~18.43）个月]较无异常组（未达到）显著缩短（χ²=12.342，P<0.001），但多因素模型纳入复杂核型进行校正后，TP53突变不再是独立预后因素。

结论

伴TP53基因异常MDS患者中基因突变较基因缺失常见，突变位点主要分布于DNA结合结构域。TP53基因异常与复杂核型相关，且常与多个基因突变相伴出现。在多因素模型纳入复杂核型校正后，TP53基因异常则不再是独立的预后因素。

[A study of clinical characteristics and prognosis of primary myelofibrosis patients with thrombocytopenia in varied degrees]

目的

探讨不同血小板水平原发性骨髓纤维化（PMF）患者的临床特征及其预后。

方法

对1990年5月1日至2017年4月30日在中国医学科学院血液病医院就诊的1 305例PMF患者进行回顾性分析。

结果

1 305例PMF患者中，重度血小板减少（PLT<50×10⁹/L）、轻度血小板减少［PLT（50～99）×10⁹/L］、无血小板减少患者（PLT≥100×10⁹/L）分别为320例（24.5％）、198例（15.2％）和787例（60.3％）。在血小板计数越低的组别中，HGB<100 g/L患者比例、WBC<4×10⁹/L患者比例和外周血原始细胞≥3％患者比例、异常染色体核型患者比例和预后不良染色体核型患者比例越高（P<0.001，P<0.001，P＝0.004，P<0.001，P<0.001），JAK2V617F突变阳性率越低（P<0.001）。血小板计数与脾肿大、HGB、WBC呈正相关（P值均<0.001，相关系数分别为0.131、0.445、0.156），与体质性症状和外周血原始细胞比例呈负相关（P值分别为0.009、0.045，相关系数为−0.096、−0.056）。重度血小板减少、轻度血小板减少、无血小板减少组患者中位生存时间分别为32、67、89个月（P<0.001）。血小板减少程度分组［HR＝1.693（95％CI 1.320～2.173），P<0.001］和动态国际预后积分系统（DIPSS）预后分级［HR＝2.051（95％CI 1.511～2.784），P<0.001］均为PMF患者独立不良预后因素。

结论

血小板计数越低的PMF患者出现贫血、白细胞减少和外周血原始细胞比例增高的比例越高、临床表现越重、预后越差，临床上应采取更加积极的治疗措施。

[Using the sequenced sample cluster analysis to study the body mass index distribution characteristics of adults in different age groups and genders]

Objective: To explore the characteristics of distribution on Chinese adult body mass index (BMI) in different age groups and genders and to provide reference related to obesity and related chronic diseases. Methods: Data from the China Health and Nutrition Survey in 2009 were used. Sequential sample cluster method was used to analyze the characteristics of BMI distribution in different age groups and genders by SAS. Results: Our results showed that the adult BMI in China should be divided into 3 groups according to their age, as 20 to 40 years old, 40 to 65 years old, and> 65 years old, in females or in total when grouped by difference of 5 years. For groupings in male, the three groups should be as 20 to 40, 40 to 60 years old and>60 years old. There were differences on distribution between the male and female groups. When grouped by difference of 10 years, all of the clusters for male, female and total groups as 20-40, 40-60 and>60 years old, became similar for the three classes, respectively, with no differences of distribution between gender, suggesting that the 5-years grouping was more accurate than the 10-years one, and BMI showing gender differences. Conclusions: BMI of the Chinese adults should be divided into 3 categories according to the characteristics of their age. Our results showed that BMI was increasing with age in youths and adolescents, remained unchanged in the middle-aged but decreasing in the elderly.

[Knowledge, related behavior and on AIDS/HIV infection among rural adults with Derung minority, in Yunnan province, 2016]

Objective: To understand the related risk behaviors, knowledge and status of HIV/AIDS infection among rural adults of Derung minority, to provide relevant messages for the development of HIV/AIDS intervention strategy in this minority group. Methods: We used system sampling method to conduct a cross-sectional survey in 6 administration villages of Derung Township, Gongshan Derung and Nu Autonomous County in Nujiang Lisu Autonomous Prefecture of Yunnan Province, with a sample size estimated as 383. Adult residents with Derung minority in six villages of Gongshan County were involved, with relevant information collected through door-to-door visit. HIV antibody was tested and SPSS 17.0 was used for statistical analysis. Results: Information on 394 valid respondents was collected, with age as between 18 and 65 (34.39±9.74), 80.7% (318/394) as married, 54.0% (213/394) having had primary school education, 13.2% (52/394) as migrant workers. In this population, the overall HIV infection rate appeared as 0.5% (2/400), mainly through sexually transmission. The rate of awareness on HIV/AIDS was 69.8% (275/394), mainly through free publicized materials 50.0% (197/394). Rates on premarital sexual behavior on multiple sexual partners in the past year, on temporary sexual partners in the past year, having commercial sexual experiences in the past year and ever used condoms when engaging in casual sex, were 6.4% (60/366), 18.0%(66/366), 5.7%(21/366), 1.9%(7/366) and 8.0%(25/311), respectively. Conclusions: Few numbers of HIV infections were identified among the migrating workers with Derung minority, with sexual transmission as the major route, along with the increased number of rural migrant workers and the low rates both on AIDS knowledge and condom use, accompanied by the high risk sexual behavior appeared in this rural adult residents of Derung minority. Relative strategies on HIV/AIDS intervention and control should be developed.

Genome-scale meta-analysis of DNA methylation during progression of lung adenocarcinoma

Identification of epigenetic alterations in tumors has become a common method for identifying genes critical to cancer development and progression. Thus, we identified DNA methylation alterations on the genome scale during lung adenocarcinoma (LADC) progression to understand the carcinogenic process and identify clinically relevant biomarkers. We found that epigenetic alterations in LADC mainly occur during the early stage of LADC progression, and there are no significant methylation differences between early-stage and late-stage LADCs. This suggests that DNA methylation alterations characterize a turning point of early events in LADC progression. By comparing DNA methylation between early-stage LADCs and normal lung tissues, we further identified 940 genes with significant alterations in DNA methylation. Sixty-seven genes were found to exhibit strong correlation between methylation alterations and expression changes, based on associated gene expression data. According to gene ontology analysis, these genes are involved in lung development, respiratory system development, cell cycle, histidine metabolism, the Wnt signaling pathway, and the p53 signaling pathway. We also found that genes on chromosome 18 most frequently showed promoter hypermethylation. Moreover, we found that LADC-associated DNA hypomethylation occurred preferentially at neither histone H3 lysine 4 nor histone H3 lysine 27 mark domains in human embryonic stem cells (NMDs) and that hypomethylation of NMDs was associated with a poor prognostic signature in LADC. Our findings have important implications for LADC progression because of the identification of novel epigenetic biomarkers potentially involved in early-stage LADC and for establishing the importance of NMD DNA hypomethylation for predicting prognosis in LADC.

Seroprevalence of Toxoplasma gondii infection in pigs in Jilin Province, Northeastern China

In the present study, a total of 1,235 porcine serum samples were collected from 9 counties in Jilin Province (40°52'~46°18'N,121°38'~131°19'E), northeastern China from August to October 2013, and the seroprevalence of Toxoplasma gondii infection was tested by indirect haemagglutination assay (IHA). The results showed that antibodies to T. gondii were found in 19.1% (95% confidence interval [CI], 16.9% to 21.3%), with higher seroprevalence in the breeding boars (28.6%, 95% CI, 20.0% to 37.2%), and breeding sows (32.0%, 95% CI, 25.2% to 38.9%). No significant difference was found among the slaughter pigs, fattening pigs and the piglets. These results indicated that infection with T. gondii in pigs is widespread in Jilin province, and is of public health concern.

Neurorestorative effect of urinary bladder matrix-mediated neural stem cell transplantation following traumatic brain injury in rats

Traumatic brain injury (TBI) is a leading cause of cell death and disability among young adults and lacks a successful therapeutic strategy. The multiphasic injuries of TBI severely limit the success of conventional pharmacological approaches. Recent successes with transplantation of stem cells in bioactive scaffolds in other injury paradigms provide new hope for the treatment of TBI. In this study, we transplanted neural stem cells (0.5x10(5) cells/µl) cultured in a bioactive scaffold derived from porcine urinary bladder matrix (UBM; 4 injection sites, 2.5µl each) into the rat brain following controlled cortical impact (CCI, velocity, 4.0 m/sec; duration, 0.5 sec; depth, 3.2mm). We evaluated the effectiveness of this strategy to combat the loss of motor, memory and cognitive faculties. Before transplantation, compatibility experiments showed that UBM was able to support extended proliferation and differentiation of neural stem cells. Together with its reported anti-inflammatory properties and rapid degradation characteristics in vivo, UBM emerged to be an ideal scaffold. The transplants reduced neuron/tissue loss and white matter injury, and also significantly ameliorated motor, memory, and cognitive impairments. Furthermore, exposure to UBM alone was sufficient to decrease the loss of sensorimotor skills from TBI (examined 3-28 days post-CCI). However, only UBMs that contained proliferating neural stem cells helped attenuate memory and cognitive impairments (examined 26-28 days post-CCI). In summary, these results demonstrate the therapeutic efficacy of stem cells in bioactive scaffolds against TBI and show promise for translation into future clinical use.

Calpastatin gene (CAST) is not associated with late onset sporadic Parkinson's disease in the Han Chinese population

Recent studies point to an association between the late-onset sporadic Parkinson’s disease (PD) and single nucleotide polymorphisms (SNPs) rs1559085 and rs27852 in Ca²⁺-dependent protease calpain inhibitor calpastatin (CAST) gene. This finding is of interest since loss of CAST activity could result in over activated calpain, potentially leading to Ca²⁺ dysregulation and loss of substantia nigra neurons in PD. We explored the association between CAST SNPs and late-onset sporadic PD in the Han Chinese population. The study included 615 evaluable patients (363 male, 252 female) with PD and 636 neurologically healthy controls (380 male, 256 female) matched for age, gender, ethnicity, and area of residence. PD cases were identified from the PD cohort of the Chinese National Consortium on Neurodegenerative Diseases (www.chinapd.cn). A total of 24 tag-SNPs were genotyped capturing 95% of the genetic variation across the CAST gene. There was no association found between any of the polymorphisms and PD in all models tested (co-dominant, dominant-effect and recessive-effect). Similarly, none of the common haplotypes was associated with a risk for PD. Our data do not support a significant association between the CAST gene polymorphisms and late onset sporadic PD in the Han Chinese population.

Fusion Expression and Antibody Preparation of the Human Transcription Factor hB1F

Human B1F was cloned from a human liver cDNA library by yeast one-hybrid screening and characterized. It is a transcription factor which belongs to nuclear receptor superfamily. The cDNA segment 450-930 of human liver transcription factor hB1F was cloned into the pGEX-3X expression vector and was expressed in E.coli. The purified GST-fused hB1F, named GST-CS, were used to immunize mice to get polyclonal antibodies to hB1F. The antiserum showed specificity to hB1F after the purification by GST-Sepharose 4B. It can be used in further investigations of the structure and function of hB1F.

Characterization of the genomic structure and tissue-specific promoter of the human nuclear receptor NR5A2 (hB1F) gene

The human homologue of the Drosophila melanogaster orphan nuclear receptor fushi tarazu factor 1 (Ftz-F1), NR5A2 (hB1F), was initially identified as a regulatory factor that binds and activates enhancer II of hepatitis B virus. NR5A2 (hB1F) is expressed specifically in pancreas and liver, playing important roles in the regulation of several liver-specific genes. A detailed analysis on the genomic structure and promoter activity will greatly promote future studies on the function of the NR5A2 (hB1F) gene. In this report, a bacterial artificial chromosome clone and several phage clones covering the NR5A2 (hB1F) gene were isolated and the complete genomic sequence was obtained. Alignment of different cDNAs of the NR5A2 (hB1F) gene with the genomic sequence facilitated the delineation of its structural organization, which spans over 150 kb and consists of eight exons interrupted by seven introns. RT-PCR and 3'-RACE revealed that utilization of two polyadenylation signals results in the 3.8 and 5.2 kb transcripts that were observed previously. The transcription start site of the NR5A2 (hB1F) gene was mapped downstream of a canonical TATA box. An upstream fragment containing binding sites for several liver-specific and ubiquitous transcription factors exhibits hepatocyte-specific promoter activity. Transient transfections indicated that hepatocyte nuclear factors HNF1 and HNF3beta could activate NR5A2 (hB1F) promoter.

[Hypoxia stimulates the expression of HSP70 in pulmonary artery smooth muscle cells]

Hypoxic pulmonary hypertension is characterized by remodeling of pulmonary artery, proliferation and migration of pulmonary artery smooth muscle cells (PASMC), the mechanism of which was studied by observing the effect of hypoxia on DNA synthesis, cell cycle phase and transcription of heat shock protein 70 (HSP70). Our results indicate that hypoxia increases DNA synthesis, enhances the mitogenic effect of ET-1 on PASMC, stimulates quiescent PASMC entering S phase from G0/G1 phase and up-regulates the mRNA level of HSP70. Heat shock proteins are conservative and important stress proteins rendering the cells more tolerable to dangerous stresses by promoting growth and survival of the cells. All these findings suggest that heat shock proteins might also be important to the proliferation of PASMC induced by hypoxia and relevant to the study of the mechanism of hypoxic vascular remodeling.

[Effect of hypoxia on the conversion of angiotensin I to A II in pulmonary vascular endothelial cells]

The effect of hypoxia on intrapulmonary conversion of angiotensin I (A I) to angiotensin II (A II) was examined by using an isolated rat lung preparation perfused at constant flow and cultured calf pulmonary artery endothelial cells. The conversion rate of A I in endothelial cells of pulmonary vascular bed was found to be decreased in both acute hypoxic and chronic hypoxic (CH-5000, CH-8000) rats. The conversion rate of A I to A II was significantly higher in acute hypoxic rat lungs than that in denuded endothelial cells rat lungs. There was no significant difference between chronic hypoxic and denuded endothelial cells rat lungs. In cultured calf pulmonary artery endothelial cells (PAEC) exposed to hypoxia (3% O2) for 30 minutes the conversion of A I to A II was significantly reduced. In the time course of hypoxic exposure the conversion of A I to A II in cultured calf PAEC showed significant difference between hypoxia and normoxia. The results indicated that (1) Acute and chronic hypoxia impaired pulmonary conversion of A I to A II. (2) Effect of hypoxia on the pulmonary conversion of A I to A II is associated with the degree and the time of hypoxia.

[Preliminary study on the effect of endothelin on the contraction of isolated rat pulmonary artery and its mechanism]

Experiment was performed on the rings of right pulmonary artery (PA) taken from male Wistar rats. Each ring was suspended in an organ bath (37 degrees C) containing Krebs solution, gassed with 95% O2-5% CO2 (pH7.40). The changes of vascular tension were measured. The contraction of PA to endothelin (ET) (10(-9) mol/L) and the effects of 764-3 (50, 100, 200, 300 micrograms/ml as a scavenger of superoxide anion), verapamil (3 x 10(-6) mol/L) NDGA, indomethacin, atropine, phentolamine, propranolol, ketanserin tartrate and diethylcarbamazine on the ET-induced contraction were investigated. The results indicated that ET can induce a potent and sustained contraction of PA, inhibited by verapamil and 764-3, but unaffected by inhibitors of cyclooxygenase, lipoxygenase, leukotrienes systhetase or adrenergic, serotonergic, cholinergic receptors. It is suggested that the influx of extracellular Ca2+ and the production of superoxide anion might be involved in the ET-induced contraction. Arachidonate metabolism and receptors mentioned above probably didn't participate in the responses.

[Reduction of genotoxic damage in oral mucosa with myasthenia gravis by traditional Chinese medicine]

Micronucleated exfoliated cell (MEC) of oral mucosa of 40 patients with myasthenia gravis (MG) and 54 normal controls were observed by means of micronucleus test. The frequency of MEC of two groups were 9.56/1000 and 2.55/1000 respectively, and their difference was remarkably significant (P < 0.001). 22 cases were treated by TCM Qiang Ji Jian Li Capsule. The frequency of MEC after treatment fell from 14.38/1000 to 6.00/1000. The difference was significant (P < 0.002). The frequency of Spleen-asthenia group higher than that of non-Spleen-asthenia (P < 0.05). The results revealed that. The patients with MG had genotoxic damage. (2) The constitution with the Spleen-asthenia and the genotoxic damage was related. (3) Qiang Ji Jian Li Capsule of invigorating the Spleen and benefiting Qi could reduce the genotoxic damage.

[Effect of chronic hypoxia on endothelium-dependent relaxation and the content of cGMP in rat pulmonary artery]

This experiment was designed to investigate whether chronic hypoxia affect rat pulmonary artery (PA) endothelium-dependent relaxation and the content of cGMP in PA. Both ACh and ATP could induce endothelium-dependent relaxation of PA, not prevented by indomethacin, but completely abolished by methylene blue. These results indicated that vasodilatation of PA induced by both ACh and ATP is mediated by EDRF (endothelium-derived relaxing factor). Chronic hypoxia significantly depressed PA endothelium-dependent relaxation. The percent relaxation of IPPA and EPPA by 10(-6) mol/L ACh was 61.3% and 59.2% of those in control, and the percent relaxation of IPPA and EPPA by 1.8 x 10(-5) mol/L ATP was 64.9% and 55.3% respectively of the control. Chronic hypoxia also depressed SNP-induced endothelium-independent relaxation. Chronic hypoxia significantly decreased the content of cGMP in PA. The basic level of cGMP was 51.9 +/- 5.7 (n = 14) in hypoxia group and 84.9 +/- 9.7 (n = 14) pmol/g wet wt. in control group (P less than 0.01). After treatment of PA with ACh (10(-7) mol/L), the content of cGMP was 91.4 +/- 7.3 (n = 5) pmol/g wet wt. in hypoxic group and 240.8 +/- 30.6 (n = 5) pmol/g wet wt. in control group (P less than 0.01). Our data suggest that chronic hypoxia might depress rat pulmonary artery endothelium-dependent relaxation through the inhibition of soluble guanylate cyclase in vascular smooth muscle cells.

Ligustrazine is a vasodilator of human pulmonary and bronchial arteries

We have investigated the dilator effect of ligustrazine, the semisynthetic principle of a traditional Chinese herbal remedy, on human pulmonary and bronchial arteries in vitro. Ligustrazine caused a concentration-dependent relaxation of human small pulmonary arteries, which was independent of endothelium. Although ligustrazine was equally potent in inducing dilatation of pulmonary and bronchial arteries, it was about 10 times more potent in relaxing small pulmonary arteries (300-500 microns i.d.) compared with lobar pulmonary arteries (7-8 mm i.d.). By contrast, the relaxant responses of small and lobar pulmonary arteries to sodium nitroprusside was not significantly different. Ligustrazine was equally potent in relaxing prostaglandin F2 alpha- or 5-hydroxytryptamine-precontracted pulmonary arteries, suggesting that it is not a prostaglandin F2 alpha or 5-hydroxytryptamine antagonist. Preincubating the vessels with propranolol (1 microM) or indomethacin (10 microM) had no significant effect on the ligustrazine-induced vasodilatation. However, ligustrazine caused concentration-dependent inhibition of calcium-evoked contraction when applied to rat aorta in calcium-free K(+)-depolarizing medium. We conclude that ligustrazine is a dilator of human pulmonary and bronchial arteries, which is endothelium-independent and that ligustrazine preferentially relaxes pulmonary resistance vessels rather than large conduit pulmonary arteries.

Enhanced reactivity to bradykinin, angiotensin I and the effect of captopril in the pulmonary vasculature of chronically hypoxic rats

We compared the reactivity of pulmonary vessels to bradykinin (BK) and angiotensin I (AI) in normal and chronically hypoxic rats; the latter have pulmonary hypertension and muscularized pulmonary arterioles. These peptides are respectively inactivated and activated by the angiotensin converting-enzyme (ACE) on pulmonary endothelium. Isolated lungs were perfused at a constant flow rate when changes in pulmonary artery pressure (Ppa) reflect changes in vascular resistance. Dose-response curves to BK (1 ng-10 micrograms) were derived during normoxia and pre-constriction by hypoxia; BK both decreased and increased vascular resistance, i.e. vasodilation and vasoconstriction. In normal rats only constriction was seen in normoxia, which reflected low basal vascular tone, whereas in chronically hypoxic rats there was only dilatation which reflected high basal vascular tone. In hypoxia in normal rats, low doses caused dilatation, high doses constriction; in chronically hypoxic rats there was again only dilatation which was larger than in controls. After the ACE-inhibitor captopril, constriction was exaggerated in control rats in both normoxia and hypoxia and took place in chronically hypoxic rats after high doses in both normoxia and hypoxia; oedema often followed. Dose-response curves to AI (1 ng-micrograms) in normoxia showed greatly enhanced pressor responses in chronically hypoxic compared with normal rats, probably attributable to increased sensitivity to angiotensin II (AII) rather than enhanced conversion of AI to AII. Captopril caused a proportionate reduction in responses in both groups of rats.(ABSTRACT TRUNCATED AT 250 WORDS)

Enhanced reactivity to bradykinin, angiotensin I and the effect of captopril in the pulmonary vasculature of chronically hypoxic rats

We compared the reactivity of pulmonary vessels to bradykinin (BK) and angiotensin I (AI) in normal and chronically hypoxic rats; the latter have pulmonary hypertension and muscularized pulmonary arterioles. These peptides are respectively inactivated and activated by the angiotensin converting-enzyme (ACE) on pulmonary endothelium. Isolated lungs were perfused at a constant flow rate when changes in pulmonary artery pressure (Ppa) reflect changes in vascular resistance. Dose-response curves to BK (1 ng-10 micrograms) were derived during normoxia and pre-constriction by hypoxia; BK both decreased and increased vascular resistance, i.e. vasodilation and vasoconstriction. In normal rats only constriction was seen in normoxia, which reflected low basal vascular tone, whereas in chronically hypoxic rats there was only dilatation which reflected high basal vascular tone. In hypoxia in normal rats, low doses caused dilatation, high doses constriction; in chronically hypoxic rats there was again only dilatation which was larger than in controls. After the ACE-inhibitor captopril, constriction was exaggerated in control rats in both normoxia and hypoxia and took place in chronically hypoxic rats after high doses in both normoxia and hypoxia; oedema often followed. Dose-response curves to AI (1 ng-micrograms) in normoxia showed greatly enhanced pressor responses in chronically hypoxic compared with normal rats, probably attributable to increased sensitivity to angiotensin II (AII) rather than enhanced conversion of AI to AII. Captopril caused a proportionate reduction in responses in both groups of rats.(ABSTRACT TRUNCATED AT 250 WORDS)

Reactivity and site of vasomotion in pulmonary vessels of chronically hypoxic rats: relation to structural changes

The high pressure muscular pulmonary circulation of chronically hypoxic (CH) rats was compared with the low pressure circuit in control (C) rats; differences were found in the effects of lung inflation, in pressure/flow relations during lung inflation, in reactivity to autocoids, and in responses to pulmonary dilator drugs. Isolated blood-perfused lungs of CH rats (2 to 3 wk in 10% O2) were compared with those of C rats kept in air. High inflation (alveolar) pressure (Palv) caused a rise in pulmonary artery pressure (Ppa) close to delta Palv in both groups; in CH rats, Ppa continued to rise, whereas it adapted to a lower level in C rats. Pressure-flow (P/Q) lines were measured at high and low Palv, all in Zone 2 state. In normoxia, high Palv caused a parallel shift in the P/Q line close to delta Palv in both C and CH rats. However, during hypoxic pulmonary vasoconstriction (HPV), high Palv caused a shift in the P/Q line less than delta Palv in C rats and greater than delta Palv in CH rats. Similar differences between C and CH rats were seen during constriction caused by almitrine, a drug that simulates HPV. Thus, these stimuli affect vessels that are functionally "extra-alveolar" in C rats but functionally "alveolar" in CH rats. We consider whether vasoconstriction by hypoxia and almitrine moves peripherally to the newly muscularized alveolar arterioles that are found in CH rats. Reactivity of lung vessels to bradykinin, angiotensin-1, and platelet-activating factor was greater in CH than in C rats, possibly also associated with muscularization of arterioles in the former.(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of ligustrazine on pulmonary vascular changes induced by chronic hypoxia in rats

1. Acute and chronic effects on the pulmonary circulation of ligustrazine, a chemically identified and synthesized principle of a Chinese herb, were studied in rats. It dilated lung vessels and reversed hypoxic pulmonary vasoconstriction. 2. In rats kept 2 weeks in 10% O2 in a normobaric chamber and simultaneously treated with ligustrazine, right ventricular hypertrophy and muscularization of pulmonary arterioles were attenuated compared with saline-treated rats. Pulmonary artery pressure, measured in isolated lungs perfused at a constant flow rate, was also less in ligustrazine-treated rats. 3. In isolated blood-perfused lungs of chronically hypoxic and control rats, the relation between pressure and flow was measured during normoxia (ventilation with air plus 5% CO2), hypoxia (2% O2 plus 5% CO2) and after ligustrazine during continued hypoxia. Alveolar pressure was always greater than left atrial pressure; thus flow was determined by the pulmonary artery minus alveolar pressure difference. 4. Pressure/flow lines were measured during normoxia in four groups of rats: (1) control, saline-treated; (2) control, ligustrazine-treated; (3) chronically hypoxic, saline-treated; (4) chronically hypoxic, ligustrazine-treated. Both chronically hypoxic groups had steeper lines (higher resistance) than the control groups, which were similar in all respects. However, in chronically hypoxic rats, the extrapolated intercept of the line on the pressure axis, probably attributable to small newly muscularized arterioles in a state of tone, was much increased in the saline-treated group but did not differ from controls in the ligustrazine-treated group.(ABSTRACT TRUNCATED AT 250 WORDS)

Responses of blood volume and red cell mass in two strains of rats acclimatized to high altitude

Two strains of rats, one that adapts successfully to high altitude (HA) (Madison = M) and the other that adapts poorly and suffers a high mortality rate at high altitude (Hilltop = H) were studied during 40 days of exposure to a simulated altitude of 18 000 ft (5450 m; PB = 175). The time rate of change of blood volume (TBV), red cell volume (RBCV), plasma volume (PV) and hematocrit (Hct), and the interrelationships of these variables, particularly emphasizing TBV, PV and Hct as functions of RBCV, were compared in the M and H strains. Sea level control values in the two strains were not different, but by the 5th day at HA RBCV and TBV had expanded to a greater extent in H than M - a difference that was maintained throughout the 40 days - but PV decreased similarly in the two strains. By 30 days the inter-strain differences of RBCV, TBV, and Hct became more pronounced but still no difference of PV was noted. The most significant feature was the greater polycythemic response of H, which at the extreme range was not associated with any further decrease of PV and therefore resulted in rapid expansion of TBV. The probable effects of these responses on cardiovascular function and oxygen transport are discussed, comparing the differences of H and M strains, which became maladaptive in H. The similarity of the responses in H to those of man with chronic mountain sickness is noted.

CSF and plasma ions and blood gases during organic metabolic acidosis in conscious rabbits

In conscious rabbits with arterial, central venous, and cisterna magna catheters, we infused HCl, Hlactate, and Hacetate so as to lower and maintain plasma [HCO3-] at the same mean values in all three groups over 6 h. The hypothesis was that the cerebrospinal fluid (CSF) [HCO3-] will depend on the changes in CO2 partial pressure (PCO2) and be determined by the net increase in the CSF concentration of the strong anion of the acid. The delta CSF [HCO3-] did correlate strongly with the delta PCO2, with the largest decrease in CSF [HCO3-] and PCO2 being in the Hacetate group, a response we attribute to a greater stimulatory effect of Hacetate on the alveolar ventilation relative to CO2 production. However, the delta CSF [HCO3-] was not simply determined in all cases by the increase in the CSF concentration of the strong anion of the acid. In HCl acidosis, statistically delta CSF [HCO3-] was equal to delta CSF [Cl-]. In H lactate acidosis delta CSF [HCO3-] was equal to the sum of a small positive delta CSF [lactate] and a small positive delta CSF [Cl-]. In Hacetate acidosis, delta CSF [HCO3-] was equal to the sum of a large positive delta CSF [acetate] and a small negative delta CSF [Cl-]. We hypothesize that in metabolic acidosis the changes in large cavity CSF [HCO3-] depend on changes in the PCO2. The strong anion regulated by the PCO2 changes is Cl-.(ABSTRACT TRUNCATED AT 250 WORDS)