The thymus as primary site for antigen-specific T suppressor cells in neonatally induced tolerance to bovine serum albumin

The ontogeny of antigen-specific T suppressor cells in thymus and spleen was analyzed in CBA/Ca mice which were rendered tolerant as neonates by subimmunogenic doses of bovine serum albumin (low-zone tolerance). Activity of T suppressor cells from those mice was assessed by an assay in which spleen cells from animals primed with fluorescein-conjugated human gamma globulin can be stimulated in vitro to produce IgG anti-fluorescein antibodies when cultured in the presence of fluorescein-conjugated bovine serum albumin. Carrier-specific T suppressor cells appear first in the thymus (day 10), and much later (day 30) in the spleen. The data are discussed in connection with the possible role of T suppressor cells during induction of tolerance in newborn mice.     

血液回收对非体外循环冠状动脉旁路移植患者红细胞和血液粘度的影响

目的观察血液回收技术对非体外循环冠状动脉旁路移植患者红细胞、血小板和血液粘度的影响。方法2005年8月~2007年10月间,共完成46例非体外循环冠状动脉旁路移植术,随机分为实验组(血液回收组)和对照组(不使用血液回收机组),每组23例。观察两组用血液制品的数量和术后24h的引流量,比较两组术前和术后24h的红细胞计数、血红蛋白、红细胞压积、血小板计数、低切全血粘度和高切全血粘度。结果实验组用浓缩红细胞和血浆的量明显少于对照组,两组术后24h引流量、术前和术后24h的红细胞计数、血红蛋白、红细胞压积、血小板计数、低切全血粘度和高切全血粘度之间的差异无显著性意义。结论血液回收技术在非体外循环冠状动脉旁路移植患者中能减少输血,对红细胞、血小板和血液粘度无不利影响。     

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.     

小檗碱对局部脑缺血组织中HIF-1α表达的影响

目的 研究大鼠局部性脑缺血再灌注损伤时,小檗碱(BE)对缺氧诱导因子-1α(HIF-1α)表达及脑神经元凋亡的影响.方法 雄性SD大鼠随机分为假手术组、大脑中动脉阻塞再灌注组(MCAO/R组)、假性治疗组(DMSO组)、小檗碱10mg/kg治疗组(BE10组)、小檗碱20mg/kg治疗组(BE20组)、小檗碱40mg/kg治疗组(BE40组).治疗组在术前48h、24h及术后6h腹腔注射相应剂量药物,观察各组大鼠神经行为学缺陷;再灌注7d,TTC染色观察脑梗死体积变化;再灌注24h,制备脑组织切片分别作Nissl染色、免疫组织化学染色、TUNEL标记及免疫荧光双标记.结果 BE20、BE40组神经功能较MCAO/R组有明显改善(P＜0.05),但BE10组神经学评分与MCAO/R组比较,差异无统计学意义(P＞0.05).不同剂量BE治疗均可以减小梗死灶体积(P＜0.05),且呈现剂量依赖性.Nissl染色可见BE治疗组皮质神经元结构较清晰,胞体肿胀、核固缩、核溶解程度较模型组及假性治疗组明显减轻,淡染区域减小;免疫组织化学法观察到,BE组HIF-1α、Caspase-3、BNIP3、VEGF及TUNEL标记的阳性细胞数减少;免疫荧光双标记显示HIF-1α与BNIP3、Caspase-3及TUNEL阳性颗粒共表达于细胞中.结论 BE可能通过降低HIF-1α水平并下调其下游的BNIP3和VEGF的表达,从而减少凋亡因子Caspase-3的作用而发挥神经元保护作用.     

Immunochemical characterization of mouse brain-associated theta (Thy-1) antigen.

The Thy-1 antigens or rat brain and thymus have been isolated and chemically characterized, but those of mice have not been identified. Moreover, it is uncertain whether the antigens are glycolipids or glycoproteins. This study with highly purified preparations of gangliosides GM₁, ¹GD_1a, GD_1b and GT_1b from bovine brain and several ganglioside fractions from mouse brain showed that Thy-1 activity does not reside in gangliosides, but rather in the chloroform-methanol-insoluble residue of brain remaining after extraction of gangliosides. The antigen could be solubilized from this residue with a non-ionic detergent. The antigenic activity of the solubilized preparation was heat-labile but resistant to periodate. The chemical properties of the Thy-1 antigen of mouse brain are discussed.     

Differential uptake of systemic fluorochrome Hoechst 33342 in lung and liver metastasis of B16 melanoma

Summary The growth and vascularization patterns of B16 melanoma colonies in the liver and lungs were measured and compared by histological techniques and dye diffusion patterns after injection of the fluorochrome Hoechst 33342. In the liver, the fluorescent pattern of dye diffusion revealed that uninodular tumours measuring up to 146 n in diameter were not functionally vascularized. However, when the nodules fused to give rise to multinodular tumours measuring between 256 and 366 n in diameter, a reticular dye diffusion pattern revealed functional tumour vascularization. In the lungs, subpleural, parenchymal and peritubular (i.e. surrounding blood vessels and airways) tumours were observed. The two former classes were vascularized down to thicknesses and diameters of 49 and 24 m respectively. In contrast, dye diffusion was never seen in peritubular tumour cuffs up to 609 m in thickness. The results indicate differences in vascularization patterns in B16 tumours in the liver and lungs, and differences between tumours growing in different sites within the lungs. If these results are applicable to metastases in these two organs, they indicate potential diffusion-mediated resistance to chemotherapy, and potential hypoxia-mediated resistance to radiotherapy of both metastases and micrometastases.     

Effects of ruthenium red on membrane ionic currents in urinary bladder smooth muscle cells of the guinea-pig

 Three major ionic currents, Ca²⁺-dependent K⁺ current (I _K-Ca), delayed rectifier type K⁺ current (I _kd) and Ca²⁺ current (I _Ca), were activated by depolarization under whole-cell clamp in single smooth muscle cells isolated from guinea-pig urinary bladder. Externally applied ruthenium red (RuR) reduced the amplitude of I _K-Ca and I _Ca at 0 mV (IC₅₀ values were 4.2 and 5.6 μM, respectively), but did not affect I _Kd. Spontaneous transient outward currents (STOCs) and caffeine-induced outward currents (I _caf) at –30 mV were reduced by external 10 μM RuR. When 10 μM RuR was added to the pipette solution, I _K-Ca during depolarization, STOCs and I _caf significantly decreased with time. RuR did not change the unitary current amplitude of the large-conductance Ca²⁺-dependent K⁺ (BK) channels, but reduced the open probability of the channel under excised patch-clamp recording mode. RuR reduced the channel activity more effectively from the cytosolic face than from the other. This inhibition decreased when the cytosolic Ca²⁺ concentration was increased. These results indicate that RuR blocks BK and Ca²⁺ channels in urinary bladder smooth muscle cells. The decrease in I _K-Ca, STOCs and I _caf by RuR is attributable to the direct inhibition of BK channel activity, probably in addition to the inhibition of Ca²⁺ release from storage sites. The direct inhibition of BK channel activity by RuR may be related to the interaction of RuR with the Ca²⁺-binding sites of the channel protein. Received: 15 October 1997 / Received after revision and accepted: 25 November 1997     

Enhanced polymer one-step staining (EPOS) for proliferating cell nuclear antigen (PCNA) and Ki-67 antigen: Application to intra-operative frozen diagnosis

Enhanced polymer one-step staining (EPOS) is a novel, highly sensitive one-step immunostaining method. This simple and rapid technlque was applied to intra-operattve frozen diagnosis. The markers of choice were proliferating cell nuclear anmen (PCNA) and Ki-67 antigen. These cell prollferation markers were both identifiable in fresh frozen see tions of the human tonsil In approximately 7 min. The suitable staining sequences are as follows. Frozen sections prepared using 3-aminopropyitimethoxysilane-cpated glass slides are immediately fixed, without air drying, for 15s in a mixture of 50% formalin and 50% methanol for PCNA, and in 10% formalln for Ki-67 antigen. After a brief rinse in phosphate-buffered saline (PSS), sections are incubated with the EPOS antibody for 3 min, followed by PBS rinse for 1 min. The peroxidase activity is visualized in diaminobenzidine-H₂O₂ solution containing 10mmol/L imidazole for 2 min. After a light rinse in tap water, the nuclei are briefly counterstained with 5% methyl green. When necessary, endogenous peroxi-dase blockage in 1% periodic acid solution for 1 min is added before the EPOS antibody incubation. This procedure is applicable to frozen sections of gastric cancers, malignant lymphomas, and brain, liver and peritoneal lesions in which differential diagnosis between benignancy and malignancy was required.     

Branches of the thoracic sympathetic trunk in the human fetus

Summary The segmental organization of the thoracic sympathetic trunk and all its ramifications was studied in 6 human fetuses (16–22 weeks) by means of the acetylcholinesterase in toto staining method. Each trunk was divided into 12 sympathetic segments. A segment is defined as that part of the sympathetic trunk which is connected via its rami communicates with one spinal nerve, without discriminating between grey and white rami. The diameter of the rami communicantes and their direction towards the spinal nerves are variable. The number of peripheral segmental ramifications of the trunk is much larger than assumed previously. Each thoracic sympathetic segment gives off at least 4–5 nerves. Three categories of nerves are discerned: (1) large splanchnic rootlets confined to the greater, lesser and least thoracic splanchnic nerves, (2) medium-sized splanchnic nerves directed towards thoracic viscera, some of which give off branches towards costovertebral joint plexuses and, described for the first time in man, (3) small nerves which ramify extensively and form nerve plexuses in the capsule of the costovertebral joints. The majority of the ramifications is formed by the nerves of the third category. The existence of Kuntz's nerve, connecting the 2nd intercostal nerve and 1st thoracic spinal nerve, is confirmed in four specimens. The nerve plexuses of the costovertebral joints receive a segmentally organized innervation: they receive their input from the neighbouring sympathetic segment and the one cranial to it.It is concluded that the thoracic sympathetic branches in man show a complex, segmentally organized pattern and may have a considerable component of somatosensory nerve fibers. The complex relationships must be taken into account in surgical sympathectomies.