Ectopic cystic thymoma associated with Raynaud's phenomenon.

Mediastinal cystic tumors are well-marginated round lesions that comprise 12% to 18% of all mediastinal masses. These lesions include a variety of diseases with overlapping radiologic appearances and variable prognoses. Pathological examinations are almost always required for differential diagnosis. We encountered a case of anterior mediastinal tumor discovered in the process of investigation of Raynaud's phenomenon. Taking into account the tumor location, a pericardial cyst was initially suspected. However, the tumor was surgically resected and histopathological examinations demonstrated thymus-like tissue in the cyst walls. Raynaud's phenomenon greatly improved after surgery. These findings suggested that cystic thymoma originated from ectopic thymic tissue and is accompanied by paraneoplastic syndrome.     

Differential sensitivity of diabetic rat papillary muscles to negative inotropic effects of oxybarbiturates versus thiobarbiturates.

The negative inotropic effects of oxybarbiturates and thiobarbiturates were examined in papillary muscles isolated from streptozotocin-induced diabetic rats and in papillary muscles from age-matched control rats. The muscles from diabetic rats exhibited less negative inotropic responses to pentobarbital and secobarbital than the muscles from control rats. Conversely, the negative inotropic responses to thiopental and thiamylal were significantly enhanced in diabetic muscles. Differences in sensitivity to pentobarbital between control and diabetic muscles became less marked by treatment with ouabain or by lowering [Na+]o. Enhancement of the negative inotropic effect of thiamylal observed in diabetic muscles remained unchanged with these treatments. In both control and diabetic muscles, the negative inotropic effect of pentobarbital was completely reversed by increasing [Ca2+]o, but the effect of thiamylal was only partially reversed. These results suggest a difference in mechanism of action involved in establishment of the negative inotropic effects of oxybarbiturates vs thiobarbiturates. Oxybarbiturates appear to exclusively reduce the influx of extracellular Ca2+, whereas thiobarbiturates appear to affect Ca2+ movements at the Ca2+ storage sites in addition to the Ca2+ influx inhibition.     

Histochemical studies on hyaluronic acid in the developing human retina

Changes in the distribution of hyaluronic acid in the developing human retina were investigated histochemically with alcian blue staining and theStreptomyces hyaluronidase digestion method using 56 human embryos and fetuses ranging from 5 to 41 weeks of gestational age. Hyaluronic acid was first detected in the inner layer of the retina at 12 weeks. The site of accumulation extended towards the outer layer by 20 weeks. At the neonatal stage, longitudinal fibers, possibly the processes of Müller cells, were proved to contain hyaluronic acid. These findings suggest that Müller cells produce hyaluronic acid transiently from 12 weeks’ gestation to the neonatal stage.     

A case of polycythemia vera complicated by chronic renal failure under hemodialysis requiring parathyroidectomy for secondary hyperparathyroidisim

A case of polycythemia vera complicated by chronic renal failure under maintenance hemodialysis requiring parathyroidectory (PTH) for secondary hyperparathyroidism (2° HPT) is reported. A 62 year old female presented with 75000 white blood cells (WBC)/μl, 703×10⁴ red blood cells (RBC)/μl, 23×10⁴ platelets (PLT)/μl, hyperuricemia and hypertension in 1970 and the diagnosis of polycythemia vera was made. Hemodialysis was started in October 1974 for chronic renal failure. Blood cells in peripheral blood rapidly decreased in number after the beginning of dialysis, reaching the level of 10000∼20000 WBC/μl, and 150∼250×10⁴RBC/μl. In August 1988, marked bone resorption in X-ray picture and high serum alkaline phosphatase and parathyroid hormone (PTH) noted along with 17400 WBC/μl, 370×10⁴RBC/μl and 35.9×10⁴PLT/μl. After subtotal PTX removing 3.21g parathyroid gland, serum PTH rapidly fell. At 3 months after PTX, WBC rose to 23600/μl, RBC 372×10⁴/μl and PLT 94.0×10⁴/μl. At 6 months, WBC was to 31000/μl, RBC 429×10⁴/μl and PLT 78.0×10⁴/μl, suggesting an inhibitory action of PTH on not only RBC, but also WBC and PLT.     

Adhesion molecules and transplantation.

OBJECTIVE: Accessory adhesion molecules are thought to influence the first interaction between host leukocytes and graft vascular endothelial cells. Their role in transplantation is reviewed. SUMMARY: Adhesion molecules have been divided into three major families: the selectins, the integrins, and the immunoglobulin superfamily. Selectins are small proteins that mediate the first contact between stimulated endothelial cells and leukocytes. Integrins interact with cytoskeletal components of cells, presumably coordinating extracellular stimuli with cytoskeleton dependent actions, such as motility, shape change, and phagocytic responses. Members of the immunoglobulin superfamily are structurally homologous, although they do not necessarily share similar functions. They are involved in T-cell proliferation and intracellular events. METHODS: Various groups of investigators have studied the influence and expression of adhesion molecules following transplantation. The authors of this article have reviewed and summarized the available literature. RESULTS: Many different adhesion molecules are up-regulated during the rejection event. Treatment of transplant recipients with monoclonal antibodies against accessory molecules, such as leukocyte function associated antigen 1 (LFA-1) and intercellular adhesion molecule 1 (ICAM-1), has resulted in either a prolongation of transplant survival or the induction of tolerance in some models. Other interventions are under study. CONCLUSION: By mediating the initial leukocyte/endothelial cell interactions, adhesion molecules may play an important role in graft rejection, mediation of infiltration into the graft, and dissemination of the antigenic message to the lymphoid tissues of the host. Future studies will have to deal not only with conceptualizing their function and mechanisms of action, but also with manipulating their interrelationships to the benefit of the graft recipient.     

Review: inducer of cytokines in vivo: overview of field and romurtide experience.

We have reported that the bacterial cell-wall skeletons, such as mycobacteria, nocardia, corynebacteria, propionibacteria and listeria, had potent adjuvant activity on immune responses. It was reported that N-acetylmuramyl-L-alanyl-D-isoglutamine (MDP) was the minimum structural requirement of adjuvant activity of the bacterial cell-wall skeleton and a variety of MDP derivatives and related compounds were synthesized. Among the synthetic MDP derivatives, we have selected MDP-Lys(L18)(romurtide) as the immunostimulant, by using experimental models for non-specific host resistance against Escherichia coli in mice. Romurtide was shown to have host-stimulating activity against bacterial, fungal and viral infections, cytokine producing activity and the capacity to increase the number of leukocytes and platelets in experimental models. It was also shown that the clinical effectiveness of romurtide on the restoration of the number of leukocytes and platelets of cancer patients treated with chemotherapy or radiation therapy. The mechanism of action of romurtide is discussed.     

Regeneration of endothelial cells after balloon denudation of the rabbit carotid artery and changes in responsiveness

The present experiments were carried out to determine the regrowth of endothelial cells (EC) after balloon denudation of the rabbit carotid artery and the changes in responsiveness of the artery with regenerated EC. Scanning electron microscopic findings revealed that 28.8% of the luminal surface was covered with regenerated EC at week 1. The regrowth of EC proceeded progressively, and a full lining was achieved at week 6. Regenerated EC were morphologically different from native ones; they were elongated (weeks 1 and 2) and irregularly oriented (weeks 4 and 6), and their numbers had significantly increased. Light microscopy revealed the intimal thickening and proliferation of smooth muscle cells. No accumulation of lipids in the vascular wall could be detected at any observation time. The experiments in an organ bath demonstrated that the altered appearance of EC was accompanied by depressed endothelium-dependent relaxations to acetylcholine, ADP and A23187. However, sodium nitroprusside-induced relaxation and contractile responses to noradrenaline, serotonin and histamine remained unchanged in the normal and denuded preparations, indicating that the dysfunction of the endothelium occurs at a time when the ability of the underlying vascular smooth muscle to relax or contract was unchanged. In addition, it is suggested that the impairment of the endothelium-dependent relaxation may be partly due to impairment of the synthesis and/or release of endothelium-derived relaxing factor(s) in EC.