乙肝病毒不同基因型的治疗策略（上）

感染乙肝病毒（HBV）后可以导致多种肝脏疾病，范围从急性或暴发型肝炎、慢性肝炎、肝硬化到肝细胞癌（HCC）。据估计，全世界约有3．5亿人感染了HBV，每年约有120万人死于持续性HBV感染导致的相关疾病。因此，除了常规接种乙肝疫苗以外，仍然需要采取有效的治疗方案用于防止慢性乙型肝炎发展到终末期肝病和HCC。抗病毒治疗的疗效受宿主和病毒的双方面影响。最近，HBV的基因分型受到重视，因为不同的基因型可能会使乙肝相关的慢性肝脏疾病呈现不同的病程并影响其最终的结果以及抗病毒治疗的效果。因此，对于临床肝病专家来说，进一步理解乙肝基因型及其与抗病毒治疗效果之间的关系就显得尤为重要，还有可能据此对慢性乙型肝炎病人设计出个性化的治疗方案。     

中国北方地区乙型肝炎病毒基因型分布的临床意义

近年发现，根据HBV DNA—S区的碱基不同，HBV的基因型可分为A～H8个基因型，不同基因型在各地区的感染率各异，感染后临床表现及对药物治疗反应有区别，为深化研究乙型肝炎的流行、预防和治疗特点，对我院收治的北方地区慢性HBV感染者进行了HBV DNA基因型检测，结合被检测者的临床情况作简要分析，发现其中一些规律，报告如下。     

乙型肝炎病毒基因型研究新进展

乙型肝炎病毒(hepatitis B virus,HBV)属于嗜肝DNA病毒科,由于HBV复制过程中HBV DNA聚合酶缺乏校正功能,导致HBV容易发生突变．根据基因序列差异的多少,可将HBV划分为A-H 8种基因型,其中A,B,C,F 4介基因型还可以划分为不同的亚型．HBV基因型呈一定的地理区域性分布．并且HBV基因型对于探讨HBV的传播途径,HBV携带者的流动形式以及变异株在不同人群中的流行情况都有很重要的意义．HBV基因型之间结构和功能的差异均可影响慢性HBV感染者在临床诊治过程中出现的基因变异、病情预后以及对抗病毒治疗的反应性．虽然近几年对HBV基因型的研究迅速增多,但尚处于探索阶段对其研究仍任重而道远．     

乙型肝炎病毒基因型、亚型与临床

随着对乙型肝炎病毒(HBV)基因型重要性的不断认识,HBV基因分型将极可能成为HBV感染日常临床诊治工作的一部分;HBV基因型还有助于人们进一步理解HBV流行病学与人口迁移;也将对慢性乙型肝炎患者的治疗与个体化管理产生积极的作用。然而,目前对HBV基因型相关的许多问题仍不十分清楚。需要更深入的研究分析不同HBV基因型之间病毒复制能力及T细胞应答是否存在差异。目前尚无关于HBV基因型之间T细胞应答是否存在差异的研究报道,而T细胞的应答是HBV感染后结局的重要因素。此外,不同HBV基因型的T细胞表位也不明晰。一些HBV基因型重组…     

乙型肝炎病毒基因型

乙型肝炎病毒(hepatitis B virus,HBV)是嗜肝DNA病毒家族的重要成员,所引起的慢性乙型病毒性肝炎及肝衰竭、肝硬化、肝癌等是严重危害人民健康的疾病.据统计,目前我国有慢性乙型肝炎患者2000万人,是我国现阶段最为突出的公共卫生问题之一.HBV遗传变异率很高,有8个基因型,由于独特的流行病学特性,多数又可以分为不同的基因亚型.另外DNA基因型的高度异质性使重组基因型也增加了.有研究证实HBV基因型与疾病进展关系密切.不同基因型HBV的流行病学特征不同,同时其临床感染特点和致病性也有差异.本文综述了本领域研究进展,包括HBV生物学特性、基因型与基因亚型、重组基因型、HBV基因型的流行病学特点以及HBV基因型与临床等方面.     

干扰素治疗慢性乙型肝炎疗效与HBV基因型的关系

目的: 探讨HBV不同基因型对干扰素抗病毒治疗的影响.方法: 对30名HBV患者进行干扰素抗病毒治疗, PCR-RFLP检测HBV基因型, 观察不同基因型HBV对干扰素的应答水平.结果: 30例患者HBV基因型以B型(40.0%)和C型(56.67%)为主, C型患者HBV DNA水平显著高于B型患者(6.03±1.35 vs 5.45±1.21,P<0.05), B型患者对干扰素应答率显著高于C型患者, 在无应答患者中分别有1名B型和C型转变为D型.结论: HBV基因型与HBV DNA复制水平、抗病毒疗效均有一定的相关性, 在治疗过程中可发生基因型改变.     

乙型肝炎病毒基因型与聚合酶基因异质性

目的 对202株乙型肝炎病毒(HBV)聚合酶基因(P基因)序列进行系统分析，研究HBV基因型间P基因差异，为进一步研究HBV基因型、P基因变异与病毒复制及核苷类似物耐药的关系提供参考。方法 采用计算机软件对GenBank中己发表的202株HBV全序列及P基因进行分析比较。结果 HBVP基因在各基因型具有自身特点：在反转录酶(rt)区，A基因型氨基酸的型内差异较小，C、D基因型氨基酸的型内差异较大，在rt区A—F6个高度保守区域，发现在基因型间及型内存在氨基酸水平的差异。结论 (1)P基因及其氨基酸存在基因型间和型内异质性，因而分析某些氨基酸差异是与耐药有关还是准株被选择的结果，应综合考虑在该位点是否存在基因型间或型内的氨基酸差异，(2)对核苷类似物抗病毒治疗应答以及治疗中耐药现象的发生在HBV不同基因型可能不同。     

HBV基因型的流行病学和病毒学特征及与临床的关系（上）

自1988年Okamoto发现HBV可分为不同基因型后，有许多学相继进行了这方面的研究。2003年日本学Sugauchi发现B基因型和C基因型之间还可能发生重组，依是否与C基因型重组分为HBVB基因型j亚型（HBV／Bj）和HBVB基因型a亚型（HBV／Ba）；2004年Sugauchi又对HBVA基因型（HBV／A）进行分析，发现HBV／A可分为e亚型（HBV／Ae）和a亚型（HBv／Aa）。现就HBV基因型的流行病学和病毒学特征及与临床的关系综述如下。     

HBV感染者病毒基因型分布特点及其与干扰素疗效的关系

目的：研究 HBV 感染者病毒基因型分布特点及其与干扰素疗效之间的关系。方法选取急性乙型肝炎（Acute hepatitis B ）8例,慢性乙型肝炎（CHB）120例,乙型肝炎肝硬化60例,肝细胞癌患者32例。提取血清 HBV DNA,PCR 扩增 S 区序列,对产物直接测序并上传至斯坦福大学 HBV 数据库,进行基因型分析;选取78例 CHB 患者（B 基因型38例,C 基因型40例）,经干扰素-α治疗48周,分析干扰素治疗不同基因型病毒感染者的疗效。结果 HBV A、B、C、D 基因型感染者分别为7.7%、35.9%、51.4%和5.0%,肝硬化和肝细胞癌患者 B 和 C 基因型感染者分别为95%和93.7%,显著高于 A 和 D 基因型感染的5%和6.3%（x2=11.364,P〈0.01）;在干扰素治疗48周后,B 基因型感染者 HBV DNA 转阴率为60.5%,显著高于 C 基因型感染者的32.5%（x2=6.014,P〈0.05）;B 基因型感染者 HBeAg/HBeAb 血清转换率为65.8%,显著高于 C 基因型感染者的27.5%（x2=10.564, P〈0.01）;B 基因型感染者血清谷丙转氨酶复常率为97.6%,显著高于 C 基因型感染者的67.5%（x2=5.387,P〈0.05）。结论 HBV 基因型以 B 和 C 基因型为主,C 基因型感染预示着不良的疾病预后和较差的干扰素治疗疗效。     

乙型肝炎病毒基因型检测的意义

慢性乙肝(CHB)预后不良，可以发展成肝硬化(LC)、肝癌(HCC)。全球每年约100万人死于乙型肝炎病毒(HBV)感染引起的相关疾病。近年来根据HBV间核苷酸序列差异可将其分为A、B、C、D、E、F、G和H等8种基因型，基因型之间的界限为异质性≥8％，而同一基因型HBV核苷酸序列的差异≤5．6％。。HBV全球流行病学进化树图结构，证实F基因型是人类HBV最早的一簇，来源于美洲，B型来源于东亚。乙型肝炎的基因型对乙型肝炎的发病、临床表现、血清学诊断及治疗有一定的影响。     

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.