CTA联合CTP对蛛网膜下腔出血所致脑血管痉挛与迟发性脑缺血的相关性探讨

目的利用CT血管造影(CTA)联合CT灌注成像(CTP)方法探讨蛛网膜下腔出血(SAH)所致脑血管痉挛(CVS)与迟发性脑缺血(DCI)的相关性。方法利用CTA与CTP技术分析116例SAH病人,CTP指标包括脑血流量(CBF)、脑血容量(CBV)、平均通过时间(MTT)等,在病人入院时、病情恶化时间段及入院后14 d记录CTA图像显示的脑血管痉挛程度和迟发性局灶脑缺血的发生情况,评估发生痉挛的脑血管支配区域与脑灌注图上血流灌注面积间的相关性及不同程度脑血管痉挛导致脑血流灌注和DCI发生之间的差异。结果 45例病人无脑血管痉挛,占38.8%;51例病人发生中等程度脑血管痉挛,占44.0%;20例病人发生严重脑血管痉挛,占17.2%。61.2%脑血管痉挛病人,最少的脑缺血灌注区域与痉挛严重血管的血流区域一致,无血管痉挛区域与严重脑缺血区域CBF明显不同。20例发生严重脑血管痉挛病人中14例出现迟发性局灶脑缺血;51例发生中等程度的脑血管痉挛病人中7例出现迟发性局灶脑缺血;45例无脑血管痉挛病人中4例出现迟发性局灶脑缺血。血管痉挛降低脑血流灌注,但只有66.67%病人脑血管痉挛与乏血供的灌注区域相一致,33.33%严重脑血管痉挛的病人无迟发性脑缺血。结论虽然严重脑血管痉挛能降低脑血流的灌注水平,但血管痉挛不会直接导致迟发性脑缺血。     

蛛网膜下腔出血后脑脊液中的致痉原与脑血管痉挛

脑血管痉挛是自发性蛛网膜下腔出血患者发生脑梗死和迟发性缺血性神经功能缺损的主要原因.对脑血管痉挛的研究目前相对集中于血性腩脊液中的致痉原方面.文章对蛛网膜下腔出血后血性脑脊液中的主要致痉原诱发脑血管痉挛的机制进行了综述.     

蛛网膜下腔出血后脑脊液中的致痉原与脑血管痉挛

脑血管痉挛是自发性蛛网膜下腔出血患者发生脑梗死和迟发性缺血性神经功能缺损的主要原因.对脑血管痉挛的研究目前相对集中于血性腩脊液中的致痉原方面.文章对蛛网膜下腔出血后血性脑脊液中的主要致痉原诱发脑血管痉挛的机制进行了综述.     

蛛网膜下腔出血后脑血管痉挛的在体动物模型

迟发性脑血管痉挛是蛛网膜下腔出血患者死亡的主要原因.一个成功的蛛网膜下腔出血后脑血管痉挛在体动物模型,有助于探讨脑血管痉挛的发生、发展等复杂多样的病理生理学机制,为临床干预提供重要信息.     

“3H”疗法防治动脉瘤性蛛网膜下腔出血后脑血管痉挛的研究进展

颅内动脉瘤破裂导致的蛛网膜下腔出血(aSAH)引发脑血管痉挛造成的迟发性脑缺血,是aSAH不良预后的主要原因之一。故预防和治疗脑血管痉挛成为了改善aSAH预后的重要目标。为了对抗脑血管痉挛导致的脑血流量下降,有学者提出了"扩充血容量、升高血压、稀释血液",即"3 H"     

蛛网膜下腔出血后脑血管痉挛的预测

脑血管痉挛(CVS)是蛛网膜下腔出血(SAH)重要的并发症,是引起SAH后脑缺血和脑梗死的病理基础,其发生率30％左右,出现时间多在SAH后3～21天。CVS分为两个阶段:急性痉挛和迟发性痉挛(DCV)。急性痉挛发生在SAH后24小时,常在24小时内缓解。迟发性痉挛不同于急性痉挛,病理解剖学可观察到血管平滑肌细胞发生形态学上的改变,一旦发生很难逆转,对血管扩张剂的反应性差。因此,迟发性痉挛的关键在于预防,有早期发现、早期用药,才能取得一定的疗     

改良Fisher分级与破裂动脉瘤患者症状性脑血管痉挛的关系

目的分析破裂出血动脉瘤患者改良Fisher分级与术后症状性脑血管痉挛发生的关系。方法按改良Fisher分级评价动脉瘤破裂出血患者216例。症状性血管痉挛的诊断根据迟发性神经功能损害并经颅多普勒检查证实。结果 216例患者中共发生症状性血管痉挛79例(36.6%),按照改良Fisher分级评价,术前不同级别的患者术后症状性脑血管痉挛发生率比较,差异有统计学意义。结论症状性脑血管痉挛的发生率与蛛网膜下腔出血量有显著的相关关系。     

内皮素、蛋白激酶C、盐酸法舒地尔和蛛网膜下腔出血

颅内动脉瘤破裂蛛网膜下腔出血 (SAH)导致的迟发性脑血管痉挛 ,是影响患者预后的主要原因。目前还没有能够有效预防和治疗脑血管痉挛的药物。近年来 ,内皮素 (ET)生成增多和蛋白激酶C(PKC)激活在脑血管痉挛过程中的作用越来越受到重视。盐酸法舒地尔 (HA10 77)是一种针对PKC的扩血管药 ,具有很强的对抗血管痉挛作用。文章综述了ET、PKC在SAH后血管痉挛过程中的作用和HA10 77对抗血管痉挛的作用。     

内皮素、蛋白激酶C、盐酸法舒地尔和蛛网膜下腔出血

颅内动脉瘤破裂蛛网膜下腔出血（SAH）导致的迟发性脑血管痉挛,是影响患者预后的主要原因。目前还没有能够有效预防和治疗脑血管痉挛的药物。近年来,内皮素（ET）生成增多和蛋白激酶C（PKC）激活在脑血管痉挛过程中的作用越来越受到重视。盐酸法舒地尔（HA1077）是一种针对PKC的扩血管药,具有很强的对抗血管痉挛作用。文章综述了ET、PKC在SAH后血管痉挛过程中的作用和HA1077对抗血管痉挛的作用。     

输注亚硝酸盐预防灵长类蛛网膜下腔出血模型迟发性脑血管痉挛

在对破裂的颅内动脉瘤成功治疗之后,至少有15%的患者会因迟发性脑血管痉挛导致永久性神经功能缺损或死亡。NO的生物利用度下降与脑血管痉挛的发生有关。为了确定输注亚硝酸盐能否预防迟发性脑血管痉挛,Pluta等进行了一项动物实验,其结果发表在最近的JAMA上。实验动物为14只经麻醉的猕猴,将自体血凝块置于右侧大脑中动脉周围。将动物分为3组:持续24h静脉输注亚硝酸钠溶液90mg加每天45mg亚硝酸钠静脉团注(n=3);持续24h静脉输注亚硝酸钠溶液180mg(n=3);或输注生理盐水(n=8)。连续输注14d。在血凝块置入前、第7天和第14天行脑动脉造影以评价…     

Three layer functional model and energy exchange concept of aging process

Relying on a certain degree of abstraction, we can propose that no particular distinction exists between animate or living matter and inanimate matter. While focusing attention on some specifics, the dividing line between the two can be drawn. The most apparent distinction is in the level of structural and functional organization with the dissimilar streams of ‘energy flow’ between the observed entity and the surrounding environment. In essence, living matter is created from inanimate matter which is organized to contain internal intense energy processes and maintain lower intensity energy exchange processes with the environment. Taking internal and external energy processes into account, we contend in this paper that living matter can be referred to as matter of dissipative structure, with this structure assumed to be a common quality of all living creatures and living matter in general. Interruption of internal energy conversion processes and terminating the controlled energy exchange with the environment leads to degeneration of dissipative structure and reduction of the same to inanimate matter, (gas, liquid and/or solid inanimate substances), and ultimately what can be called ‘death.’ This concept of what we call dissipative nature can be extended from living organisms to social groups of animals, to mankind. An analogy based on the organization of matter provides a basis for a functional model of living entities. The models relies on the parallels among the three central structures of any cell (nucleus, cytoplasm and outer membrane) and the human body (central organs, body fluids along with the connective tissues, and external skin integument). This three-part structural organization may be observed almost universally in nature. It can be observed from the atomic structure to the planetary and intergalactic organizations. This similarity is corroborated by the membrane theory applied to living organisms. According to the energy nature of living matter and the proposed functional model, the decreased integrity of a human body's external envelope membrane is a first cause of the structural degradation and aging of the entire organism. The aging process than progresses externally to internally, as in single cell organisms, suggesting that much of the efforts towards the restoration and maintenance of the mechanisms responsible for structural development should be focused accordingly, on the membrane, i.e., the skin. Numerous reports indicate that all parts of the human body, like: bones, blood with blood vessels, muscles, skin, and so on, have some ability for restoration. Therefore, actual revival of not only aging tissue of the human body's membrane, but the entire human body enclosed within, with all internal organs, might be expected. We assess several aging theories within the context of our model and provide suggestions on how to activate the body's own anti-aging mechanisms and increase longevity. This paper presents some analogies and some distinctions that exist between the living dissipative structure matter and inanimate matter, discusses the aging process and proposes certain aging reversal solutions.     

Unusual responses of nocturnal pineal melatonin synthesis and secretion to swimming: Attempts to define mechanisms

Abstract: The effect of swimming at night on rat pineal melatonin synthesis was compared with that of light exposure at night. Rats were forced to swim at 0030 hr (lights out at 2000 hr) and sacrificed by decapitation 15 and 30 min later, immediately after swimming. Other groups of animals were exposed to white light (650μW/cm²) for 15 and 30 min at same time. Swimming caused a rapid and highly significant drop in the melatonin content in the pineal gland; however, the activity of N-acetyltransferase (NAT), the supposed rate limiting enzyme in the melatonin production, was not changed. Despite the drop in pineal melatonin levels, serum concentrations of the indole remained elevated in the rats that swam. In contrast, melatonin levels in the pineal and serum of light exposed rats fell precipitously, accompanied by a significant suppression of NAT activity. Since we anticipated that the strenuous exercise associated with swimming may induce release of artrial natriuretic peptide (ANP) from the heart, which in turn could cause the release of pineal melatonin, in a second study we injected physiological saline intravenously to stretch the cardiac muscle and release ANP. Three milliliters of normal saline was injected during the day into the jugular vein of anesthetized rats that were pretreated with isoproterenol to stimulate pineal melatonin production. Animals were killed 15 min after the saline injection, and pineal NAT activity and pineal melatonin levels were measured. The saline injections caused no alteration in the elevated levels of either NAT or melatonin. These data suggest that the disparity in pineal NAT activity (which was high) and pineal melatonin (which was low), in animals swum at night, may not be caused by ANP which is released during strenuous exercise such as swimming.     

Melatonin and photoperiodic time measurement: Seasonal breeding in the sheep

Abstract: Well-established circadian physiology supports the view that photoperiodic time measurement utilizes the coincidence between the presence of light and a photosensitive phase of a 'biological clock' to alter reproductive status—the so-called external coincidence model of seasonal breeding. In this review, we examine the mechanism whereby photoperiod interacts with presumed suprachiasmatic nuclei activity to allow endogenous melatonin to normally synchronize reproductive activity to the optimal time of year. The Romney Marsh sheep is particularly explored as an experimental model. It is suggested that the on/off activity of seasonal reproduction may be a robust mechanism able to be predictably manipulated by the judicious use of the light/dark cycle and exogenous melatonin, but firmly based on circadian principles.     

Serological survey of HIV and syphilis in pregnant women in Madagascar

Objectives Peripartal transmission of human immunodeficiency virus (HIV) and Treponema pallidum, the causative agent of syphilis, leads to severe consequences for newborns. Preventive measures require awareness of the maternal infection. Although HIV and syphilis testing in Madagascar could be theoretically carried out within the framework of the national pregnancy follow‐up scheme, the required test kits are rarely available at peripheral health centres. In this study, we screened blood samples of pregnant Madagascan women for HIV and syphilis seroprevalence to estimate the demand for systemic screening in pregnancy. Methods Retrospective anonymous serological analysis for HIV and syphilis was performed in plasma samples from 1232 pregnant women that were taken between May and July 2010 in Ambositra, Ifanadiana, Manakara, Mananjary, Moramanga and Tsiroanomandidy (Madagascar) during pregnancy follow‐up. Screening was based on Treponema pallidum haemagglutination tests for syphilis and rapid tests for HIV, with confirmation of positive screening results on line assays. Results Out of 1232 pregnant women, none were seropositive for HIV and 37 (3%) were seropositive for Treponema pallidum. Conclusions Our findings are in line with previous studies that describe considerable syphilis prevalence in the rural Madagascan population. The results suggest a need for screening to prevent peripartal Treponema pallidum transmission, while HIV is still rare. If they are known, Treponema pallidum infections can be easily, safely and inexpensively treated even in pregnancy to reduce the risk of transmission.     

Variabilité des concentrations plasmatiques de l’angiotensinogène et risque d’hypertension artérielle chez le rat transgénique

Aim

Genetic polymorphisms of the human angiotensinogen gene are frequent and may induce up to 30% increase of plasma angiotensinogen concentrations with a blood pressure increase of up to 5 mmHg. Their role for the pathogenesis of human arterial hypertension remains unclear. High plasma angiotensinogen levels could increase the sensitivity to other blood pressure stressors.

Methods

Male transgenic rats with a 9-fold increase of plasma angiotensinogen concentrations and male non-transgenic rats aged 10 weeks were treated or not with NG-Nitro-L-arginine-methyl ester for 3 weeks in their drinking water (n = 3/group). Systolic blood pressure and body weight were measured at baseline and at the end of the study when left ventricular weight and ventricular expression of angiotensin I-converting enzyme and procollagen Iα1 were determined (polymerase chain reaction).

Results

At baseline, transgenic rats had +18 mmHg higher bood pressure and –8% lower body weight compared to non-transgenic rats (P < 0.05) without significant changes for the vehicle groups throughout the study (P > 0.05). NG-Nitro-L-arginine-methyl ester increased blood pressure, left ventricular weight and left ventricular weight indexed for body weight by +41%, +17.6% and +18.6% (P < 0.05) in transgenic and +25%, +5.3% and +6.7% (P > 0.05) in non-transgenic rats compared to untreated animals, respectively. Cardiac gene expression showed no differences between groups (P > 0.05).

Conclusion

Increased plasma angiotensinogen levels may sensitize to additional blood pressure stressors. Our preliminary results point towards an independent role of angiotensinogen in the pathogenesis of human hypertension and associated end-organ damage.     

Morphological and immunocytochemical heterogeneity of cultured pinealocytes from one-week-and two-month-old rats: Planimetric and densitometric investigations

Abstract: In vitro preparations of rat pinealocytes are widely used for biochemical analyses of signal transduction processes. This paper deals with morphological and immunocytochemical features of such preparations. Special attention was paid to the problems of whether pinealocytes represent a heterogeneous cell population and how such heterogeneity may develop during ontogeny. The investigations were performed with cells which were obtained from the pineal organ of one-week-and two-month-old rats, attached to synthetic peptide-coated coverslips or tissue culture chamber slides, and maintained under in vitro conditions overnight. The attached cells were then fixed with paraformaldehyde. These preparations yielded monolayers of spherical cells of different sizes; most cells were isolated, but some of them were aggregated and formed small clusters. On the average, the cells from the one-week-old animals were smaller than the cells from the two-month-old animals. Immunocytochemical demonstration of S-antigen, a pinealocyte-specific marker, showed that the majority of the cells from two-month-old animals were intensely or moderately labelled. Pinealocytes from one-week-old animals were less S-antigen immunoreactive. Only very few cells (less than 1% displayed glial fibrillary acidic protein (GFAP)-immunoreactivity. Planimetric investigations of the cell size and semiquantitative densitometric investigations of the intensity of the S-antigen immunoreaction revealed that (i) pinealocytes kept in vitro form a heterogeneous cell population, and that (ii) this heterogeneity increases during postnatal development from one-week-old to two-month-old animals. Two groups of pinealocytes can be distinguished based on their developmental fate: pinealocytes of one group grow dramatically, but show only a moderate increase in S-antigen immunoreactivity, and pinealocytes of the other group retain their size, but display a distinct increment in S-antigen immunoreacti vitv.     

Effects of pinealectomy and melatonin administration on certain indices of ovarian hyperplasia and/or hypertrophy in rats with both ovaries intact or after unilateral ovariectomy

Abstract: In earlier studies from other laboratories it was shown that melatonin decreased ovarian weight in rats and inhibited compensatory hypertrophy of the remaining ovary after unilateral ovariectomy. This study was designed to examine the influence of melatonin on certain indices of ovarian hyperplasia and/or hypertrophy in adult female rats with both ovaries preserved and with either an intact pineal gland or with the pineal gland removed (pinealectomy, PX) or, finally, in sham-PX animals. Similar studies were conducted on rats after unilateral ovariectomy, referring the examined parameters to the remaining intact ovary. The studies included mitotic activity of granulosa layer cells and corpus luteum cells, ovarian weight, ovarian cross-sectional area, cross-sectional area of the granulosa layer of all the Graafian follicles and the cross-sectional areas of the corpora lutea, visible on the ovarian cross-section. On the basis of results, we conclude that: 1) the effect of PX on the processes of ovarian hyperplasia and hypertrophy may vary; analogously, exogenous melatonin administration may influence ovarian hyperplasia and hypertrophy in different ways; 2) PX and exogenous melatonin may, under certain conditions, exert similar biological effects, even synergistic effects; 3) melatonin inhibits ovarian growth processes, while the effects of PX are variable; 4) the results indicate that in experiments performed on rats, with the use of two control groups, i.e., intact and sham-PX, melatonin effects on these two groups may differ.