The regional distribution of adenosine-regulating enzymes in the left and right ventricle walls of control and hypertrophic heart

Summary The transmural distribution of the adenosine-generating enzyme 5-nucleotidase (5N) and of the adenosine-degrading enzymes adenosine deaminase (ADA), AMP deaminase (AMP-D) and adenosine kinase (Ado-K) were determined across the walls of left and right ventricles of control and hypertrophic rat hearts.The enzyme distribution across the left ventricle wall (but not across the right wall) of normal hearts was not uniform: 5N activity shows its highest levels in the subepicardial and in the subendocardial regions, whereas all the other enzyme activities show their lowest levels. A similar pattern of transmural distribution was also detected in other mammalian species (ox and pig).In the experimental cardiac hypertrophy, caused by two different types of chronic cardiac overload, the levels and the profiles of transmural distribution of 5N and ADA enzyme activities may significantly change across the rat left ventricle wall.     

Pigments of the Gastrointestinal Tract: A Comparison of Light Microscopic and Electron Microscopic Findings

It is now apparent that light microscopy and histochemistry failed to identify correctly the nature and composition of pigments in various gastrointestinal tract melanoses. In most instances it was thought that the pigment was melanin or a melanin-like substance. Electron microscopy (EM) and electron-probe energy dispersive x-ray analysis have rectified these errors and have shown the following: in melanosis coli the pigment granules contain lipofuscin; in melanoses ilei the pigment granules may contain either silicates and titanium or hemosiderin; and in melanosis duodeni the pigment granules contain iron sulfide. In melanosis esophagi it is not clear what the pigment is; it could be melanin or lipofuscin.     

Response of body temperature and serum iron concentration to repeated pyrogen injection in rabbits

We measured body temperature and serum iron concentration after five daily consecutive injections of febrile doses of Salmonella typhosa lipopolysaccharide (0.1 g/kg) and two doses of Staphylococcus aureus cell walls (1×10⁷ and 5×10⁷ cells) in rabbits. Tolerance to endotoxin injection, as manifest by a significant attenuation in the body temperature elevation, developed after the first injection of endotoxin. The endotoxin-induced fall in serum iron concentration was attenuated significantly by the 5th day of endotoxin injection. In contrast, no tolerance developed in either the body temperature or serum iron response following repeated daily injections of S. aureus. Rabbits rendered tolerant to endotoxin showed normal febrile and serum iron responses to subsequent S. aureus injection. Rabbits given serial injections of S. aureus, although not tolerant to S. aureus itself, exhibited attenuated body temperature responses but not serum iron responses to endotoxin injection. We suggest that repeated injection of endotoxin diminishes the ability of endotoxin to stimulate endogenous pyrogen (EP) synthesis and/or release, a property not shared by the gram-positive pyrogen S. aureus. However, repeated injection of S. aureus weakens the central endotoxin-EP pathway.     

Experimental osteodystrophy of chronic renal failure induced by aluminum- and ferric-nitrilotriacetate in Wistar rats

The aluminum (Al) and iron (Fe) chelate complexes of nitrilotriacetate (NTA) cause renal insufficiency when they are administered intraperitoneally to rats. Their effects on bone metabolism were studied in 4 week old Wistar rats. Daily intraperitoneal administration of Al-NTA (3 mg Al/kg for 11 weeks) induced osteomalacia, impaired bone growth, decreased bone mineral density, lower serum PTH levels than normal as well as renal insufficiency. Al staining showed diffuse deposition in the trabecula and a strong linear band of aluminum deposited at the mineralization front and along the cement line. The osteoid seen markedly within the trabecula was probably the decalcified portion of the bone, the calcium apatite of which was defectively fabricated because of diffuse Al deposition in the trabecula. Al deposition along the cement line would make it much more susceptible to external shear stress than normal. Although daily intraperitoneal administration of Fe-NTA (6 mg Fe/kg for 11 weeks) caused impaired bone growth, decreased bone mineral content and renal insufficiency, the osteoid volume did not increase. Fe staining showed that Fe was deposited diffusely in the cytoplasm of osteoblasts. The results of this study demonstrated that during renal insufficiency, different minerals exhibi different modes of action on bone metabolism, and that AI-NTA is useful for experimental animal models of Al-induced osteomalacia in renal insufficiency.     

Cardiac Myxoma: Histochemical and Ultrastructural Localization of Glycosaminoglycans and Proteoglycans

A recurrent cardiac myxoma is examined histochemical ly at the ultrastructural level. By routine electron microscopy the stellate “myxoma” cell exhibits features suggestive of a secretory function in synthesis of its myxoid stroma. Spicer's high iron diamine (HID), which stains specifically for sulfated glycoconjugates, is utilized for intracellular localization of glycosaminoglycans. HID-positive reactive sites are localized within the Golgi-derived vacuoles and secretory granules of the myxoma cells. No staining is obtained with other cytoplasmic organelles except rare secondary lyso-somes. Although colloidal iron is less specific, both intracellular and extracellular positive reactive sites are observed. With ruthenium red staining the proteoglycans in the extracellular stroma can be visualized as numerous positively stained, polygonal 250-500 A matrix granules with faint filamentous projections. Positive intracellular ruthenium red-stained granules are also observed within the Golgi-derived vacuoles. The alcianophilia of the myxoid stroma with Alcian blue is almost completely abolished by prior treatment with bovine testicular hyaluronidase but is unaffected by leech hyaluronidase, indicating chondroitin sulfates A and/or C, not hyaluronic acid, as the major biochemical constituents of the stroma and the observed extracellular matrix granules. The above findings provide cytochemical evidence of intracellular synthesis of sulfated glycosaminoglycans and proteoglycans of the myxoma cell and its active participation in production of its stroma.     

Third trimester iron status and pregnancy outcome in non-anaemic women; pregnancy unfavourably affected by maternal iron excess

A prospective observational study was performed on 488 women with haemoglobin >/=10 g/dl at booking to examine the relationship between serum ferritin concentration quartiles at 28-30 weeks gestation with maternal characteristics, pregnancy complications and infant outcome. While there was no difference in the maternal characteristics or gestational age, the infant size decreased significantly and progressively from the lowest to the highest quartile. Despite a significant difference in the incidence of multiparous women, there was no difference in the incidence of most complications except for prelabour rupture of the membranes and infant admission to the neonatal unit. Compared with the other three quartiles, the highest quartile was associated with increased risk for preterm delivery and neonatal asphyxia, while the lowest quartile was associated with decreased risk of pre-eclampsia, prelabour rupture of the membranes, and infant admission to the neonatal unit. Overall, ferritin quartiles were correlated with other parameters of iron status and red cell indices, and ferritin concentration was inversely correlated with infant birthweight. Our findings suggested that maternal ferritin concentration is primarily a reflection of maternal iron status, and a high level is associated with unfavourable outcome. The rationale of routine iron supplementation in non-anaemic women needs to be re-examined.     

缺铁性贫血对学龄儿童某些认知能力影响的研究

本文采用双盲法对 IDA 和 NIDA学龄儿童各61名进行了认知能力测验及铁治疗前后的动态比较。结果表明:IDA 儿童识记再认、字母匹配反应时、数字扫描记忆和一般推理能力测验成绩较 NIDA 儿童差。经铁治疗的IDA 儿童,注意、短时记忆和心理动作反应速度均有明显提高。但对较高级认知能力的改善不明显。     

儿童铁缺乏对血清IgG亚类及PnPs特异性IgG亚类抗体的影响

本文测定铁缺乏症患儿血清IgG亚类(47例)和PnPs特异性IgG_1、IgG_2抗体(18例)。发现47例缺铁儿童中28例伴IgG亚类缺陷,各亚类缺陷检出率依次为:IgG_4 27.66％(13/47)、IgG_1 21.28％(10/47)、IgG_2 14.89％(7/47)、IgG_2 2.13％(1/47)。与同龄正常儿童比较,缺铁组血清IgG_4和IgG_1均值以及PnPs特异性IgG_1、IgG_2抗体水平明显降低;缺铁患儿外周血CD~+_4细胞百分率及CD~+_4/CD~+_8细胞比值降低,IL-6活性、T淋巴细胞增殖反应减低。缺铁时反复呼吸道感染率(占63.83％)亦明显增高。提示缺铁不仅致T细胞功能受损,B细胞功能亦明显障碍。     

压力超负荷大鼠心、肺、肾血管重构的动态研究

目的 探讨压力超负荷与大鼠心、肺、肾内小动脉形态学重建的关系。方法 采用缩窄腹主动脉造成大鼠压力负荷模型，将大鼠随机分为两组：假手术组（SOG)和手术组(OG)。每组分为术后1、2、4、7、14、21、30、45、60d 9个时间点，对大鼠心、肺、肾组织连续切片，采用光镜配合计算机图像分析技术检测三个脏器小动脉几何形态的动态改变。结果 (1)随着压力负荷的增加，心、肺、肾小动脉的形态学重建可能存在时间顺序。(2)平均动脉压和造模时间与小冠状动脉和肾小动脉的壁腔比显著相关，而对小冠状动脉的管壁面积无影响；收缩压和造模时间与肾小动脉的管壁面积显著相关；造模时间与肺小动脉的壁腔比和管壁面积显著相关。结论 压力超负荷与心、肺、肾小血管的动态重构关系密切。小冠状动脉的重建以中膜平滑肌细胞的重排为主，肺、肾内小动脉的重建则可能存在中膜平滑肌细胞的肥大和增殖。