缬沙坦和卡托普利干预高血压大鼠左室心肌纤维化及超微结构改变的比较研究

目的比较缬沙坦和卡托普利对心肌纤维化及超微结构改变的干预作用.方法14周龄自发性高血压大鼠(SHR)25只随机分为5组缬沙坦组(SHRv)、卡托普利组(SHRc)、卡托普利组+缬沙坦组(SHRc+v)、假治对照组(SHR20)和高血压基础对照组(SHR14).同周龄SD大鼠5只设为正常对照组(SD20).疗程为6周.处死后测算左室重量/体重比(LVM/BW)、光镜观察心肌胶原分布,测算胶原容积分数(CVF)、血管周围胶原面积/管腔面积比(PVCA/LA)和组织匀浆胶原浓度,电镜观察心肌超微结构改变.结果三个治疗组反映心肌纤维化的多项指标均较SHR20和SHR14组显著改善(P＜0.01&0.05).SHRv与SHRc+v组的改善相似,均优于SHRc组(P＜0.05),但仍差于SD20组(P＜0.05).心肌超微结构改变均较SHR20组显著好转.结论缬沙坦和卡托普利均能抑制高血压心肌纤维化及超微结构改变,但短期治疗不能恢复正常.缬沙坦的作用优于卡托普利,两者联用优于单用卡托普利,但并不显著优于单用缬沙坦.     

缬沙坦治疗对自发性高血压大鼠心肌纤维化的影响

目的　观察缬沙坦对自发性高血压大鼠 (SHR)心肌纤维化的影响。方法　 3 0只 12周龄雄性SHR大鼠 ,随机分成3组 :(1)大剂量缬沙坦组 (n =10缬沙坦 3 0mg/kg·d) ;(2 )小剂量缬沙坦组 (n =10缬沙坦 10mg/kg·d) ;(3 )SHR空白对照组 (n =10 ) ;(4)同龄雄性正常血压WKY大鼠对照组 (n =10 )。给药 4周 ;天狼星红染色法使胶原特殊染色 ,计算机图象分析测量心肌切片的胶原容积分数和心肌小动脉周围胶原面积与小动脉面积比表示心肌纤维化程度。结果　与SHR组相比大小剂量缬沙坦组 ,均能有效降低SHR血压 (P <0 0 5)。并能改善SHR大鼠左心室肥厚 (P <0 0 5)并使心室内、外膜及心肌小动脉周围的胶原减少 ,其中大剂量组各指标均较SHR有显著差异 (P <0 0 5)。结论　缬沙坦对SHR大鼠的心肌纤维有显著的抑制作用     

缬沙坦和卡托普利干预高血压左室心肌肥厚与血中某些活性因子的比较研究

目的：比较缬沙坦对心肌肥厚和纤维化的干预作用是否优于卡托普利，两联用是否更为有益，并对作用机理进行分析探讨。方法：79例伴有左室肥厚的轻、中度高血压病患，随机分为3组：缬沙坦组，缬沙坦80－160mg qd；卡托普利组，卡托普利25－50mg bid；卡托普利＋缬沙坦组，卡托普利12．5－25mg bid 缬沙坦40－80mg qd。治疗期为8个月。另设正常对照组。观测室间隔厚度、左室重量指数、左室相关壁厚度、左室射血分数、二尖瓣口舒张早期和晚期血流速度比（VE／VA）、血浆血管紧张素Ⅱ（Ang Ⅱ)、醛固酮（Ald)、血清I型前胶原羧基端肽（PI CP）和Ⅲ型前胶原氨基端肽（PⅢ NP）等指标，进行治疗前后及组间比较。另对各治疗组每组6例患，观察上述指标的动态变化。结果：各组治疗后反映心肌肥厚和纤维化以及左室舒张功能的各项指标均显改善（P＜0．05，P＜0．01），但未达正常。组间比较差异不显。动态观察卡托普利组Ang Ⅱ及Ald先下降，后出现“逃逸”现象，但此后血清PI CP、PⅢ NP及超声心动图改变仍继续好转。结论：（1）缬沙坦和卡托普利单用或联用均能抑制和逆转高血压心肌肥厚与纤维化，改善舒张功能；（2）缬沙坦组短期治疗的益处未见明显优于卡托普利，两联用未见明显优势；（3）卡托普利持续治疗后出现Ang Ⅱ及Ald“逃逸”现象，但心肌重塑却继续好转。其作用机制与降低Ang Ⅱ的确切关系还有待深入研究。     

阻断肾素-血管紧张素-醛固酮系统对自发性高血压大鼠左室肥厚及心肌纤维化的逆转作用

目的：观察阻断肾素-血管紧张素-醛固酮系统不同部位对高血压左室肥厚（LVH）及心肌纤维化的逆转作用。方法：对26周龄自发性高血压大鼠（SHR）分别采用血管紧张素转换酶抑制剂（ACEI）──苯那普利（A组）、AgⅡ－AT1──氯沙坦（B组）、醛固酮受体阻断剂──安体舒通（C组）治疗12周,观察治疗前后大鼠血压、心肌重量、心肌间质胶原的变化。另取26周龄（D组）、38周龄（E组）Wistar大鼠和26周龄（F组）、38周龄（G组）未做任何治疗的SHR作为对照。结果：F组、G组的血压、左室重量／体重（LVW／BW）、胶原及Ⅰ型、Ⅲ型胶原所占的容积百分比含量均高于D组、E组。A组上组经治疗后,血压、LVW／BW、胶原含量及Ⅰ型、Ⅲ型胶原容积分数均较未治疗的G组明显下降（P＜0．05）。C组血压、LVW／BW无明显下降,而胶原含量及Ⅰ型、Ⅲ型胶原容积分数明显降低（P＜0．05）。结论：ACEI、AgⅡ-AT1阻断剂明显降低血压,逆转LVH,消退心肌纤维化;而醛固酮受体阻断剂未能很好降压,对LVH的逆转作用不大,但对心肌纤维化的消退有一定作用。     

通心络治疗对自发性高血压大鼠心肌纤维化的影响

目的：观察通心络对自发性高血压大鼠(SHR)心肌纤维化的影响。方法：30只12周龄雄性SHR大鼠，随机分成大剂量通心络组、小剂量通心络组、SHR空白对照组3组，每组10只；另取10只同龄雄性正常血压WKY大鼠作为对照组。给药12周，天狼星红染色法使肢原特殊染色，计算机图像分析测量心肌切片的肢原容积分数和心肌小动脉周围肢原面积与小动脉面积比表示心肌纤维化程度；放免法(RIA)测定血浆AngⅡ的浓度：结果：与SHR组相比，大、小剂量通心络组均能在一定程度上抑制S服血压升高(P＜0．05)。通心络大、小剂量组治疗均能在一定程度上改善SHR大鼠左心室肥厚(P＜0．05)，并使心室内、外膜及心肌小动脉周围的胶原减少，同时血浆AngⅡ浓度较SHR组下降，其中大剂量组各指标均较SHR有统计学意义(P＜0．05)。结论：通心络对SHR大鼠的心肌纤维化有显著的抑制作用。     

缬沙坦治疗对自发性高血压大鼠心肌纤维化的影响

目的观察缬沙坦对自发性高血压大鼠(SHR)心肌纤维化的影响.方法 30只12周龄雄性SHR大鼠,随机分成3组(1)大剂量缬沙坦组(n=10 缬沙坦30 mg/kg*d);(2)小剂量缬沙坦组(n=10 缬沙坦10 mg/kg*d); (3)SHR空白对照组(n=10);(4) 同龄雄性正常血压WKY 大鼠对照组(n=10).给药4周; 天狼星红染色法使胶原特殊染色,计算机图象分析测量心肌切片的胶原容积分数和心肌小动脉周围胶原面积与小动脉面积比表示心肌纤维化程度.结果与SHR组相比大小剂量缬沙坦组,均能有效降低SHR血压(P<0.05).并能改善SHR大鼠左心室肥厚(P<0.05)并使心室内、外膜及心肌小动脉周围的胶原减少,其中大剂量组各指标均较SHR有显著差异(P<0.05).结论缬沙坦对SHR大鼠的心肌纤维有显著的抑制作用.     

卡托普利对自发性高血压大鼠心肌纤维化的影响

通过测定自发性高血压大鼠(SHR)左、右心室胶原含量和浓度,观察了高血压情况下心肌间质的改变及卡托普利对其的影响。结果表明,14周龄SHR在血压升高,左室肥厚(LVH)同时,胶原含量亦增加;12周后,治疗组SHR血压显著降低,LVH消退。并且,左、右室胶原浓度分别较未治疗组下降26％及13％,接近正常对照组水平。提示伴随心肌重量增加,SIIR心肌间质亦有胶原纤维异常堆积;卡托普利具有抗纤维化作用,可能通过抑制肾素—血管紧张素—醛固酮系统而实现。     

缬沙坦和螺内酯对自发性高血压大鼠心肌整和素β1的作用

目的　比较自发性高血压大鼠 (SHR)和WKY心肌整和素β1的表达以及缬沙坦和螺内酯对SHR整和素 β1的影响。方法　将 18只 6周龄SHR随机分成 3组 ,每组 6只。其中 2组分别灌喂缬沙坦 2 0mg·kg- 1·d- 1,和螺内酯 10mg·kg- 1·d- 1,另一对照组给正常饮水 ,并与雄性同周龄WKY6只比较。实验期 14周 ,免疫组化法检测四组大鼠心肌整和素 β1的表达。结果　SHR对照组心肌整和素 β1表达明显高于WKY组 ,和SHR对照组比较缬沙坦组整和素 β1的表达下降 (P <0 0 5) ,而螺内酯组整和素 β1的表达无显著改变 ;两治疗组血压、LVM/BW以及心肌纤维化程度均显著低于SHR组 (P <0 0 5) ,而且两治疗组间比较缬沙坦组血压和心肌纤维化程度降低更明显 (P <0 0 5)。结论　缬沙坦除降低血压外 ,还能抑制整和素 β1表达 ,而螺内酯对整和素β1的表达无明显抑制作用 ;而缬沙坦对心肌纤维化的抑制作用优于螺内酯。提示整和素 β1在高血压心肌纤维化进程中起了一定作用     

缬沙坦对自发性高血压大鼠整合素β1和纤维黏连蛋白表达的影响

目的研究缬沙坦对自发性高血压大鼠(SHR)左室心肌整合素β1和纤维黏连蛋白(FN)表达的影响,探讨高血压心肌纤维化的机制.方法选用6周龄的雄性SHR 12只,随机均分为2组SHR阳性对照组;缬沙坦干预组(SHR-V),灌喂缬沙坦20 mg*kg-1*d-1.另选同源正常血压的WKY大鼠6只为正常对照组.实验期14周.观察血压、左室重量/体重(LVW/BW)、胶原容积分数,并用免疫组化法检测3组大鼠心肌整合素β1和FN的表达.结果缬沙坦可显著降低SHR的血压、LVW/BW及左室心肌的胶原含量,此外SHR阳性对照组整合素β1 和FN 的表达明显高于正常对照组(P<0.05),而SHR-V组两者的表达显著低于SHR阳性对照组(P<0.05).结论缬沙坦除可降低血压外,还能显著抑制整合素β1 和FN的表达,抑制甚至逆转心肌纤维化过程.     

缬沙坦和螺内酯对自发性高血压大鼠心肌整和素β1 的作用

目的比较自发性高血压大鼠(SHR)和WKY心肌整和素β1 的表达以及缬沙坦和螺内酯对SHR整和素β1的影响.方法将18只6周龄SHR随机分成3组,每组6只.其中2组分别灌喂缬沙坦20 mg*kg-1*d-1,和螺内酯10 mg*kg-1*d-1,另一对照组给正常饮水,并与雄性同周龄WKY6只比较.实验期14周,免疫组化法检测四组大鼠心肌整和素β1的表达.结果 SHR对照组心肌整和素β1表达明显高于WKY组,和SHR对照组比较缬沙坦组整和素β1的表达下降(P<0.05),而螺内酯组整和素β1 的表达无显著改变;两治疗组血压、LVM/BW以及心肌纤维化程度均显著低于SHR组(P<0.05),而且两治疗组间比较缬沙坦组血压和心肌纤维化程度降低更明显(P<0.05).结论缬沙坦除降低血压外,还能抑制整和素β1表达,而螺内酯对整和素β1 的表达无明显抑制作用;而缬沙坦对心肌纤维化的抑制作用优于螺内酯.提示整和素β1在高血压心肌纤维化进程中起了一定作用.     

Glucose and insulin concentration in amniotic fluid and in maternal blood in early and in late pregnancy

Glucose concentration in the amniotic fluid decreases towards the end of gestation, whereas the insulin concentration increases. The ratio between fetal (amniotic fluid) glucose to maternal glucose is reduced by about 50% at the end of pregnancy, whereas the ratio of C peptide is increased four times. The higher glucose concentration in amniotic fluid in early pregnancy could be explained by a lower fetal metabolic rate in the early stage of development and a low insulin activity of the fetus.     

Differentiation pathways in carcinogenesis and in chemo- and radioresistance

Cancer stem cells (CSCs) share many features with embryonic stem cells (ESCs) such as the ability for self-renewal and differentiation. Signaling pathways that are involved in these processes are also involved in chemo- and radioresistance (e.g. Wnt, Notch and Hedgehog pathways). This review is focused on the influence of three important differentiation pathways on carcinogenesis and on chemo- and radioresistance in ESCs and CSCs.     

Nitrite and thiocyanate in the fasting and secreting stomach and in saliva.

The concentrations of nitrite and thiocyanate in fasting and pentagastrin stimulated gastric juice and in saliva have been examined. Nitrite was found in all of 17 samples of fasting gastric juice, mean 4-9 +/- 1-1 muM. Stimulation of gastric secretion with pentagastrin caused no significant change in nitrite concentration. Thiocyanate was detected in all of 21 samples of fasting gastric juice and the difference in concentration between smokers and non-smokers probably reflects similar differences in saliva. In contrast to the nitrite data there was a significant drop in thiocyanate concentration of gastric juice after pentagastrin from 0-9 +/- 0-1 mM to 0-3 +/- 0-04 mM, suggesting a salivary origin for the thiocyanate in gastric juice. Thiocyanate is a powerful catalyst of nitrosation, which, together with small amounts of nitrite and naturally occurring amines could lead to the intragastric formation of carcinogenic nitrosamines and in certain circumstances be a factor in the aetiology of gastric cancer.     

Anti-malarial efficacy of pyronaridine and artesunate in combination in vitro and in vivo

Pyronaridine is a Mannich base anti-malarial with demonstrated efficacy against drug resistant Plasmodium falciparum, P. vivax, P. ovale and P. malariae. However, resistance to pyronaridine can develop quickly when it is used alone but can be considerably delayed when it is administered with artesunate in rodent malaria models. The aim of this study was to evaluate the efficacy of pyronaridine in combination with artesunate against P. falciparum in vitro and in rodent malaria models in vivo to support its clinical application. Pyronaridine showed consistently high levels of in vitro activity against a panel of six P. falciparum drug-sensitive and resistant strains (Geometric Mean IC50=2.24 nM, 95% CI=1.20-3.27). In vitro interactions between pyronaridine and artesunate showed a slight antagonistic trend, but in vivo compared to pyronaridine and artesunate administered alone, the 3:1 ratio of the combination, reduced the ED90 of artesunate by approximately 15.6-fold in a pyronaridine-resistant P. berghei line and by approximately 200-fold in an artesunate-resistant line of P. berghei. Complete cure rates were achieved with doses of the combination above or equal to 8 mg/kg per day against P. chabaudi AS. These results indicate that the combination had an enhanced effect over monotherapy and lower daily doses of artesunate could be used to obtain a curative effect. The data suggest that the combination of pyronaridine and artesunate should have potential in areas of multi-drug resistant malaria.     

Osteoporosis in celiac disease and in endocrine and reproductive disorders

As the increase in lifespan brings to light diseases that were previously not clinically detectable, osteoporosis has become an issue of worldwide significance. The disease is marked by a loss of bone mass; the bones become less dense, fragile and more prone to fracturing. Because it is regulated by endocrine and environmental factors, osteoporosis presents a multifactorial etiopathogenesis, with the genetic component accounting for 70% of an individual variation in bone mass density （BMD）, the principal determinant, with age, of fracture risk. Pathological conditions such as celiac disease （CD） exacerbate the process of bone loss, so that the occurrence of osteoporosis in celiac subjects is of particular note： indeed, the screening of osteoporosis patients for this disease is advisable, since it may be the only sign of undiagnosed CD. An increase in interleukin IL-1β, of the IL-1 system, in the relatives of celiac patients confirms the genetic predisposition to osteoporosis and its presence is evidence of an association between the two conditions. The direct effect on the bones of CD is secondary to poor absorption of calcium and vitamin D. In women osteoporosis is indirectly associated with early menopause and amenorrhea, and it may follow prolonged breast-feeding and frequent pregnancies, while in men it is associated with hypogonadism and GH deficit. These endocrine and non-endocrine factors exert their effects on bones by modulating the RANK/RANK-L/OPG system. An appropriate lifestyle from adolescence onwards, together with early diagnosis of and treatment for CD and primaryand secondary endocrine pathologies are important for the prevention of damage to the bones.     

Salmonellosis in children in developing and developed countries and populations

PURPOSE OF REVIEW: The present review addresses recent developments that relate to the clinical management and prevention of childhood salmonellosis in developed and developing countries. RECENT FINDINGS: Invasive disease due to serovar Typhi as well as nontyphoidal salmonellae (NTS) is common in children younger than 5 years old in developing countries, and multidrug resistance is an increasingly difficult problem to manage. A new conjugate vaccine was found to be very effective in preventing typhoid fever in young Vietnamese children and was well tolerated, showing great promise for the future. Antibiotic use in the food animal industry is an important source of disease with multidrug resistant NTS strains in the developed world. Efforts for prevention are aimed at immunization of animals, control of antibiotic use in the food animal industry and careful monitoring of food-borne outbreaks. On the other hand, although the burden of NTS disease in children is far greater in developing countries, especially in tropical Africa, knowledge of even basic epidemiology is lacking. Importantly, it may be that, as spp. acquire increasing resistance, they also acquire increasing virulence that will lead to even greater morbidity and mortality. SUMMARY: Recent developments include a better knowledge of clinical aspects of invasive salmonellosis, an increasing response to the problem of multiple antibiotic resistance (including quinolones), and excellent results from the use of a recently developed conjugate vaccine for typhoid fever in children as young as 2 years old.