Ultrastructural alterations of collagen fibrils in blood vessel walls

With increasing concern for elucidation of the role of connective tissues in degenerative diseases of blood vessels, an ultrastructural study was conducted on collagen fibrils of intimal proliferation in experimental autogenous venous pouch aneurysms in rabbits and in atherosclerotic human arteries. The fibrils were compared morphometrically with adventitial collagen as controls. In intimal proliferation from both species intimal collagen fibrils displayed increased variation in shape and size when compared to adventitial collagen fibrils. The abnormal fibrils resembled those of inherited connective tissue diseases, indicating that the changes in collagen fibrils can be acquired and that hemodynamic stress is likely to contribute to their occurrence.     

The source of NMR-detected motional anisotropy of water in blood vessel walls

2H Double quantum-filtered (DQF) NMR spectroscopy of deuterated water is sensitive to the presence of order in biological systems. This is because the only nuclei that are detected are those with residual quadrupolar interactions due to their anisotropic motion. In the present study, samples of aorta, coronary and carotid arteries, and vena cava were studied in parallel by 2H DQF NMR and by light microscopy. The average quadrupolar splitting, calculated from the NMR data, varies considerably among the different blood vessels, with high reproducibility for each type of vessel. Polarization microscopy examinations using collagen-specific staining with picrosirius red, have shown a variety of color profiles for the different blood vessels. These reflect different physical modes of aggregation (packing and thickness) of collagen fibers. A correlation was found between the NMR parameters and the color profiles of the picrosirius red-stained sections. Treating the blood vessels with 90% formic acid resulted in the elimination of the 2H DQF NMR signal. Histological analysis demonstrated a complete degradation of collagen and muscle, whereas the elastin filaments were preserved. Evidence is given that the 2H DQF NMR signal is dominated by the contribution of water molecules interacting with the collagen fibers.     

Recording of unexpectedly high frequency vibrations of blood vessel walls in experimental arteriovenous fistulae of rabbits using a laser vibrometer

Because arteriovenous fistulae are associated with a palpable thrill and an audible murmur, the vibrational activity of the blood vessel walls about experimental arteriovenous fistulae in rabbits was investigated using, for the first time, a high-resolution laser vibrometer. Frequencies of mural vibrations up to 2200 Hz were recorded at different sites about the fistulae. The relationship of this vibratory activity of blood vessel walls to physiological and pathological conditions warrants further investigation.     

Histamine levels in the blood of humans experimental animals under normal conditions and following vaccination]

The authors present the results of study of the blood histamine content in intact rabbits and in the animals to which commercial vaccines with a different degree of reactogenic property for man were administered. The blood histamine level was also studied in practically healthy individuals and in those vaccinated with inactivated tick-borne encephalitis vaccine. The blood histamine content varied in intact rabbits from 4 to 10 microgram/ml, averaging 6.4 +/- 0.09 microgram/ml. Animal immunization caused elevation of the blood histamine content correlating with the reactogenic properties of the preparations for man: vaccines with low reactogenic properties--inactivated encephalitis and live measles vaccine produced no significant changes in the index under study; as to the typhoid vaccine with sextatoxoid, and smallpox vaccine with marked reactogenic properties--they stimulated significant histaminemia in rabbits. Revaccination of man against tick-borne encephalitis with the inactivated cultural vaccine caused an increase in the blood histamine content.     

Kinetics of the response of spleen cells from tumor-bearing animals in an in vivo tumor neutralization assay

The behavior of spleen cells from tumor-bearing mice, vis-à-vis isologous tumor cells, was investigated by means of an in vivo adoptive neutralization test. C3H/eB mice were challenged with tumor cells from a chemically induced fibrosarcoma. Spleens from these animals were removed at weekly intervals following tumor inoculation, mixed with tumor cells, and tested for their influence on tumor growth in syngeneic recipient mice. Two phases in the reactivity of spleen cells from tumor-bearing mice were clearly distinguishable. In a first stage of tumor growth, these mice yielded specific tumor-inhibitory cells conferring protection. Subsequently, the protective activity declined leading to a second phase characterized by tumor enhancement. Both protective and enhancing activities were shown to be mainly dependent on the presence of T cells.     

Defective function of Langerhans cells in tumor-bearing animals is the result of defective maturation from hemopoietic progenitors

Langerhans cells (LC), the APCs in the skin, serve as a model for investigation of dendritic cell (DC) function in tissues. DC play a crucial role in the generation of antitumor immune responses. In this study, we investigated the effect of the presence of tumor in vivo on the ability of LC to take up Ag, migrate to draining lymph nodes, and stimulate primary T cell responses. In two animal models, these functions were substantially inhibited. This effect was not restricted to LC located in the skin near a tumor but was also seen at sites distant from the tumor. The duration of tumor exposure, and not its ultimate size, were found to be important, suggesting that tumors could be inhibiting the maturation of LC rather than directly inhibiting their function. Model experiments with radiation chimeras supported this hypothesis. To investigate the potential role of vascular endothelial growth factor (VEGF) in these effects we used anti-VEGF-neutralizing Ab to treat animals bearing tumors. Treatment with the Ab at a dose of 10 microg i.p. per mouse, twice a week for 4 wk, significantly improved the number and function of LC as measured by their ability to migrate to lymph nodes and stimulate primary T cell responses, even at doses that do not affect the growth of these established poorly immunogenic tumors. Thus, inhibition of VEGF signaling may improve DC function in tumor-bearing hosts and possibly serve to improve the efficacy of cancer immunotherapy.     

Characteristic of antithromboplastic activity of human blood serum]

The ability of human blood serum for inactivating tissue thromboplastin is established to be due to the presence of two inhibitors: thermolabile inhibitor characterized by a progressive effect and thermostable one having an instant effect. Thromboplastin inhibition by the thermolabile inhibitor is partial, whereas inhibition by the thermostable one is completely reversible. In the latter case inhibition is intermediate character, between the competitive and incompetitive one. The inhibitory activity is found in Cohn's fraction V, is removed during DEAE-cellulos chromatography and gel chromatography with the first portions of eluating liquid.     

Pharmacokinetics of rifampicin in experimental animals]

Rifampicin is rapidly absorbed when administered orally. Its high levels were detected during 1 to 3 hours after administration. The antibiotic was preserved in the blood serum in therapeutic concentrations for at least 24 hours depending on the dose used. When used repeatedly, it did not cumulate. Rifampicin easily penetrated into the organs and tissues of the animals, the highest concentrations being observed in the liver and kidneys. The antibiotic was mainly excreted with the bile. The drug pharmacokinetics depended on the animal species.     

适量献血可以避免心脑血管疾病

自1998年10月1日<中华人民共和国献血法>颁布实施以来,无偿献血人数有了较大提高,尤其是街头无偿献血者,特别是外五县的居民,文化层次不算太高,但在献血的概率上确挺高.约占献血者的60%以上.他们对无偿献血的知识、态度及行为只是从义务献血制度,实际上还是属于有偿献血制度到实施无偿献血制度这个跨度中.他们只认为献血就可以改善心脑血管疾病,防止血稠,不得脑血栓,而踊跃献血.从国内心血管专家对127名多次献血者、87例高血压者、60例缺血性中风者,进行血液流变学的对照研究,结果表明,证实了这一点.适量献血可减少或避免心脑血管疾病的发生.     

Genetic markers in the blood of animals: a historical review

One-photon emission computed tomography (OPECT) was used to examine 87 patients with the epileptiform syndrome. Eighty five patients had impaired drug distribution which was suggestive of varying degree cerebral circulatory disorders. OPECT with a Tc-99m-gm-pao used in patients with the epileptiform syndrome revealed the morphological substract of brain structures. OPECT findings in the patients suggested the brain structural microcirculatory changes to be diffuse and focal, of varying magnitude. There was no clear correlation between clinical manifestations and OPECT and CT findings.