Scar formation in the central nervous system under the influence of pyrogenal

Summary Pyrogenal was used in 21 dogs in an attempt to prevent rapid scar formation between the stumps of the severed spinal cord. Pathomorphological studies of the medullary scar were undertaken 14 days. 1, 3, 6, 12, and 26 months after the operation. It was shown that pyrogenal interferes with scar formation at the site of section of the spinal cord. In all cases, even at later dates, the scar of the experimental animals was of a looser structure, the maturation of the fibroblasts was delayed, macrophages were present and the tissues were better vascularized. Pyrogenal had a more marked effect on the inhibition of formation of collagen fibers.(Presented by Active Member AMN SSSR V. V. Parin) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 50, No. 11. pp. 121–123, November, 1960     

Scar formation after ischemic myocardial injury in MRL mice.

INTRODUCTION: MRL is a strain of mice with the unusual ability to recover from injuries without forming scar tissue. It was recently reported that the MRL mice can recover with little or no scar formation following a cryogenically induced myocardial infarction of the right ventricle. These findings suggest that scarless recovery from myocardial injury is possible in mammalian ventricles. If applicable to humans, these results could have significant clinical implications in the management of patients with myocardial infarction. However, myocardial infarction in human patients usually results from ischemic injury instead of cryoinjury. Myocardial infarction usually occurs in the left ventricle. METHODS: We performed a prospective study creating left ventricular myocardial infarction in 32 MRL mice using coronary ligation. RESULTS: Among them, 21 mice survived surgery and had myocardial infarction documented by delayed contrast-enhanced magnetic resonance imaging (MRI) 35+/-10 days after surgery. All 21 mice had evidence of myocardial infarction in follow-up MRI performed 116+/-21 days after surgery. The infarct size was 27+/-12% of the area of visualized myocardium during the first MRI study and was 29+/-11% during the second MRI study (P=NS). Large myocardial infarction with aneurysm formation was documented by histological examinations in all 21 mice. The ventricular aneurysm showed transmural infarction with replacement fibrosis and mummified necrotic myocardium surrounded by collagenous scar tissue. Occasional surviving myocytes are present within the aneurysm. CONCLUSION: Ischemic myocardial injury in MRL mice is not followed by scarless recovery.     

Contraction of Scar Tissue in the Rabbit Vitreous

Sheets of vitreous membrane (scar tissue) and associated retinal detachment were produced in the right eye of 86 adult New Zealand white rabbits by intravitreal injection of cultured autologous skin fibroblasts. The membranes were examined by light and electron microscopy and time-lapse cinephotomicrography. Immuno-histochemistry was used to demonstrate alterations in the distribution of cytoplasmic contractile proteins. While retinal detachment and membrane contraction were taking place, there was pronounced increase in the numbers of fibroblasts with an elongated spindle shape. These spindle-shaped cells had some similarities to myofibroblasts including the presence of ‘stress cables’. However, the myofibroblast-like cells stained much less avidly for cytoplasmic (actin) microfilaments than migratory fibroblasts seen at early stages of membrane development. The significance of migrating fibroblasts and myofibroblasts in scar contraction is discussed.     

腹腔镜在瘢痕子宫全子宫切除术中的应用

目的 分析腹腔镜在瘢痕子宫全子宫切除术中应用的可行性和安全性。方法 选择2018年3月~2019年3月在我院行腹腔镜全子宫切除术的患者98例,依据子宫是否瘢痕分为瘢痕组和非瘢痕组,各49例。比较两组手术时间、术中出血量、肛门排气时间、下床活动时间、并发症以及1次剖宫产与2次或以上剖宫产患者手术指标和并发症情况（术中出血量＞500 ml、膀胱穿孔、盆腔血肿、阴道残端出血）。结果 瘢痕组手术时间、术中出血量均高于非瘢痕组,差异有统计学意义（P＜0.05）;瘢痕组肛门排气时间、下床活动时间与非瘢痕组比较,差异无统计学意义（P＞0.05）;瘢痕组并发症发生率为12.24%,与非瘢痕组的16.33%比较,差异无统计学意义（P＞0.05）;1次剖宫产患者手术时间、术中出血量均低于2次或以上剖宫产患者,差异有统计学意义（P＜0.05）;1次剖宫产患者并发症发生率为17.86%,与2次或以上剖宫产患者的14.29%比较,差异无统计学意义（P＞0.05）。结论 腹腔镜应用于瘢痕子宫全子宫切除术中难度大于非瘢痕子宫,手术时间相对较长,术中出血量相对较多。但仍具有良好的安全可行性,且多次剖宫产患者在有经验的医生操作下,仍可经腹腔镜完成手术。     

The Fibrotic Scar in Neurological Disorders

Tissue fibrosis, or scar formation, is a common response to damage in most organs of the body. The central nervous system (CNS) is special in that fibrogenic cells are restricted to vascular and meningeal niches. However, disruption of the blood–brain barrier and inflammation can unleash stromal cells and trigger scar formation. Astroglia segregate from the inflammatory lesion core, and the so‐called “glial scar” composed of hypertrophic astrocytes seals off the intact neural tissue from damage. In the lesion core, a second type of “fibrotic scar” develops, which is sensitive to inflammatory mediators. Genetic fate mapping studies suggest that pericytes and perivascular fibroblasts are activated, but other precursor cells may also be involved in generating a transient fibrous extracellular matrix in the CNS. The stromal cells sense inflammation and attract immune cells, which in turn drive myofibroblast transdifferentiation. We believe that the fibrotic scar represents a major barrier to CNS regeneration. Targeting of fibrosis may therefore prove to be a valuable therapeutic strategy for neurological disorders such as stroke, spinal cord injury and multiple sclerosis.     

Dexamethasone enhances mallory body formation in drug-primed mouse liver

In a clinical study in which patients with alcoholic hepatitis were treated with prednisone for 1 month, posttreatment liver biopsies showed diminished inflammation, but Mallory bodies were not diminished. This suggested that steroid treatment may reduce inflammation by inhibiting NFkappaB activation. Sparing of Mallory bodies suggests that NFkappaB activation may not be involved mechanistically in Mallory body formation. To test this idea, we induced Mallory body formation in drug-primed mice with or without dexamethasone treatment. As predicted, dexamethasone decreased NFkappaB activation; however, Mallory body formation was increased. Surprisingly, TNFalpha and iNOS, which normally increase as a result of NFkappaB activation, were upregulated by the dexamethasone treatment. It was concluded that NFkappaB activation is not involved in Mallory body formation. Despite this, induced increases in TNFalpha, iNOS, c-jun/API and c-myc expression indicate that oxidative stress is likely involved in Mallory body formation.     

Mechanism of disturbances of energy formation in acute ischemia of the liver

Respiration of rat liver mitochondria after the addition of ischemic toxin to the incubation medium was compared with respiration of mitochondria isolated from ischemic rat liver. The changes in respiration in both cases could be prevented by preliminary addition of dithiothreitol and reduced by subsequent addition of cytochrome c or dithiothreitol to the incubation medium. The similarity between the mechanisms of disturbance of energy formation is postulated.Laboratory of Transplantation of Organs and Tissues, Academy of Medical Sciences of the USSR, Moscow. Institute of Clinical and Experimental Medicine, Academy of Medical Sciences of the USSR, Siberian Branch, Novosibirsk. (Presented by Academician of the Academy of Medical Sciences of the USSR V. V. Kovanov.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 84, No. 9, pp. 301–303, September, 1977.     

Effect of osteopontin alleles on beta-glucan-induced granuloma formation in the mouse liver

The granuloma formation is a host defense response against persistent irritants. Osteopontin is centrally involved in the formation of granulomas. Three osteopontin alleles, designated a, b, and c, have been found in mice. Here we used a murine model of zymosan (beta-glucan)-induced granuloma formation in the liver to determine possible functional differences between the osteopontin alleles in cell-mediated immunity. In contrast to mice with alleles a or c, mice with the allele b was defective in granuloma formation. As detected by mRNA expression, cytokines and chemokines known to be critically involved in granuloma formation were elicited in liver tissue, regardless of the osteopontin allele expressed. Alignment of the deduced amino acid sequences showed that unlike osteopontin c, b differs from a in 11 amino acids. All three osteopontin alleles had normal cell-binding properties. However, only the b allelic form was defective in the induction of cell migration as tested with dendritic cells. In conclusion, generation of a granulomatous response in mice depends critically on the presence of a functional osteopontin allele. Defective granuloma formation in mice with allele b is likely to be because of an impaired chemotactic function of the osteopontin b protein on immunocompetent cells.     

肝外胆道动力学因素在胆囊结石形成中的作用

目的：探讨肝外胆道动力学因素在胆囊结石形成中的作用。方法：选用家兔４７只随机分为４组。对照组（ｎ＝１３），成石组（ｎ＝１４），消炎痛组（ｎ＝１０），红霉素组（ｎ＝１０）。饲养４周后检测成石情况、胆总管压力等指标。结果：成石组１２／１４只形成结石，消炎痛组４／１０只形成结石，红霉素组无一只形成结石。成石组胆汁中胆固醇和粘蛋白含量显著增高，胆囊管阻力和胆总管压力显著增高，胆囊排空率显著降低。消炎痛组较成石组胆汁中粘蛋白浓度降低，胆囊管阻力下降，胆总管压力下降，胆囊排空率无显著改善。红霉素组较成石组胆汁粘蛋白含量下降，胆囊管阻力下降，胆囊排空率增加而胆总管压力无显著变化。结论：除胆汁成分异常外，肝外胆道动力学因素参与了胆囊结石形成，改变肝外胆道动力学因素以促进胆囊排空，能有效地防止胆囊结石形成