Localization of tissue transglutaminase in human carotid and coronary artery atherosclerosis: implications for plaque stability and progression

Although atherosclerosis progresses in an indolent state for decades, the rupture of plaques creates acute ischemic syndromes that may culminate in myocardial infarction and stroke. Mechanical forces and matrix metalloproteinase activity initiate plaque rupture, whereas tissue inhibitors of metalloproteinases have an important (albeit indirect) role in plaque stabilization. In this paper, an enzyme that could directly stabilize the plaque is described. Tissue transglutaminase (TG) catalyzes the formation of epsilon(gamma-glutamyl)lysine isopeptide bonds that are resistant to enzymatic, mechanical, and chemical degradation. We performed immunohistochemistry for TG in atherosclerotic human coronary and carotid arteries. TG was most prominent along the luminal endothelium and in the medium of the vessels with a distribution mirroring that of smooth muscle cells. Variable, often prominent, immunoreactivity for TG was also seen in the intima, especially in regions with significant neovascularization. Additionally, TG was detected in fibrous caps and near the "shoulder regions" of some plaques. A monoclonal antibody to the transglutaminase product epsilon(gamma-glutamyl)lysine isopeptide demonstrated co-localization with TG antigen. Transglutaminase activity was found in 6 of 14 coronary artery atherectomy samples. Cross-linking of TG substrates such as fibrinogen, fibronectin, vitronectin, collagen type I, and protease inhibitors stabilized the plaque. Furthermore, the activation of transforming growth factor-beta-1 by TG might be an additional mechanism for the promotion of plaque stabilization and progression by increasing the synthesis of extracellular matrix components.     

Role of fine-needle aspiration cytology in childhood malignancies

During the last 4 yr, fine-needle aspiration cytology (FNAC) has been employed in 1,474 patients in 0-15-yr age group at our institute. Of these, 245 patients were found to have malignant disease, including primitive neuroectodermal tumors, hepatoblastoma, nephroblastoma, sarcoma, and epithelial malignancies. Four metastases from medulloblastoma and two each from astrocytoma and meningioma were confirmed without open biopsy. FNAC interpretation was easy when cytologic findings were correlated with relevant clinical and radiologic data.     

Bilateral microphthalmia with cyst,facial clefts,and limb anomalies: a new syndrome with features of Waardenburg syndrome,cerebro-oculo-nasal syndrome,and craniotelencephalic dysplasia

We report a patient with bilateral microphthalmia with cyst, limb anomalies, and multiple facial malformations. This patient has clinical features similar to Waardenburg ophthalmo-acromelic syndrome, cerebro-oculo-nasal syndrome, and craniotelencephalic dysplasia. Although all of these syndromes are characterized by microphthalmia, the presently reported patient does not have the complete pattern of any of these syndromes, It is possible that he has a previously undescribed syndrome, most closely related to the cerebro-oculo-nasal syndrome with malformations outside the craniofacial region. More case reports are needed to further delineate this possibly new syndrome.     

Round worm migration along ventriculoperitoneal shunt tract: a rare complication

Though a ventriculoperitoneal shunt has been associated with myriads of unusual complications, so has been that with roundworms. A case of a three-year-old boy is presented who had an unusual complication of roundworm migration along the shunt tract that presented as shunt tract infection.     

The location and distribution of type A and type B atrial endings in cats

Summary In the attempt to explain the difference in discharge pattern of atrial endings, 131 endings were localized by punctate stimulation, 44 were type A, 77 type B and 10 of an intermediate type. All were located on the dorsal wall of the atria with none on the ventral wall or in the appendage. On the right side, 74% of type A were located in the atria and 63% of type B in or near the veins. On the left side, 67% of type A and 94% of type B were located in or near the veins. Thus, there appeared to be some difference in the location of type A and type B endings on the right side, but on the left side both types of endings were for the most part confined to the venous region. Further, on both right and left sides, these endings were present both in the central part of the atria and in or adjacent to veins. This leads to the suggestion that the difference in discharge patterns is not caused by the location but may be due to some other reasons, e. g. difference of arrangement in the atrial wall with respect to the contractile elements.     

Astrocytes and intracerebral immune responses

The astrocyte is the most abundant cell within the central nervous system (CNS). This cell subserves a multiplicity of important functions that contribute to the process of neural development as well as to the integrity of normal brain function. Adding to the already exhaustive list of capabilities, the astrocyte has now been demonstrated to function as an intracerebral antigen presenting cell. These findings are serving to revise our view of the brain as an immunoprivileged site and perhaps will shed some light on the pathogenetic mechanisms involved in a number of CNS disorders of immune dysregulation. In this review we provide some perspective on the regulatory mechanisms that influence astrocyte immune functions. Specifically, we address the role played by the major histocompatibility complex (MHC) antigens as well as adhesion molecules in the initiation of brain immune responses.