Light and electron microscopic studies on human temporal arteries with special reference to alterations related to senescence, atherosclerosis and giant cell arteritis.

Temporal artery biopsy specimens from 26 patients of various ages with and without giant cell arteritis afforded an opportunity to examine several ultrastructural features of these human muscular arteries, including senescent and atherosclerotic alterations and the fine structural pathology of temporal arteritis. The unusual pathologic features of temporal arteritis were found superimposed on the progressive accumulation of smooth muscle cells, collagen and occasional discrete intimal atherosclerotic plaques in the intima of aging arteries. Two features of giant cell arteritis were conspicuous: first, the accumulation of large numbers of histiocytes and epitheloid and giant cells at the intimal-medial junction and second, fragmentation, degeneration and dissolution of the internal elastic lamina. The close proximity of the granulomatous reaction to the degenerating lamina suggests that these two aspects of the pathologic picture are in some way related, and possible immunologic mechanisms of this relationship are discussed on the basis of the ultrastructural findings.     

Histochemical study on systemic amyloid microdeposits with special reference to parathyroid intrafollicular deposits

Summary This study was carried out in order to define the histochemical behaviour of the substance present in follicles of normal parathyroid glands obtained at routine autopsies. It was noticed that these follicles with typical amyloid staining properties are constantly present in old persons; furthermore the amyloid in question presents histochemical characteristics which identify it as Apudamyloid.With this in mind we studied the possible, concomitant, systemic, amyloid microdeposits; we noticed that intrafollicular Apudamyloid of the parathyroid gland is often encountered together with immune deposits which are sometimes present in the same gland though not necessarily in the follicles.We are grateful to Mr. L. Bortoletto for his technical assistance.     

Immunological and histological studies of temporal arteries from patients with temporal arteritis and/or polymyalgia rheumatica.

Biopsies from the temporal arteries of 62 out of 80 patients presenting the clinical picture of temporal arteritis and/or polymyalgia rheumatica showed morphologically active or healed arteritis. Fifty-five of these biopsies revealed anti-IgG activity as measured by the mixed agglutination test. In 21 of the 27 cases which could be completely studied, the anti-IgG activity was connected with the presence of IgA, either alone, or together with IgG or IgM, or both, and complement. All of these 21 biopsies showed morphologically active granulomatous arteritis with signs of tissue destruction. In 6 biopsies, the active component appeared to be some type of Fc receptor in the tissue. Morphologically these biopsies showed either non-granulomatous mononuclear arteritis without definite necrosis or they represented various stages of healing arteritis with no or minor signs of tissue destruction. Weak anti-IgG activity was often found in a morphological type characterized by minimal inflammatory activity. These lesions are easily overlooked and the mixed agglutination test proved to be a good diagnostic tool in such cases. Arteries without anti-IgG activity showed no signs of active arteritis.     

Plasmacytoid monocytes in cat scratch disease with special reference to the histological diversity of suppurative lesions

It has been suggested that plasmacytoid monocytes (PMOs) play an essential role in T-cell-dependent immune response. Indeed, numerous PMOs are found in close topographical association with epithelioid cell granulomas in hypersensitivity-type granulomas, such as tuberculosis and sarcoidosis. The key pathologic process in cat scratch disease (CSD) usually involves a B-cell-associated granulomatous reaction. Histologically, CSD appears to exhibit a histopathologic diversity, including suppurative lesions without epithelioid cell granulomas (early lesion), in which the microabscesses were surrounded by monocytoid B-cells (MBCs), suppurative granulomas containing MBCs (intermediate lesion), and suppurative granulomas without MBCs (late lesion). However, the presence or absence of PMO in CSD has not been studied previously. We examined 14 cases of CSD. In early lesions, numerous clusters of PMO were detected in the MBCs. In intermediate lesions, both MBCs and PMOs were found to be decreased in number, while late lesions contained no or only a few MBCs and PMOs. Overall, these findings suggest that PMOs may play a role in MBC-associated granulomatous response and in hypersensitivity granulomatous response. Moreover, the association with MBCs and PMOs indicates a functional relationship of MBCs with PMOs in the formation of suppurative lesions in CSD.     

Bacteriological study of pyogenic meningitis with special reference to C-reactive protein

Seventy five clinically, biochemically and microscopically diagnosed cases of pyogenic meningitis including 28 adults and 47 paediatric patients were studied. Gram positive isolates in adults and gram negative bacilli in paediatric age group were the predominant organisms. Estimation of C-reactive protein (CRP) in cerebrospinal fluid (CSF) and serum was done in all cases as an early marker for rapid diagnosis of pyogenic meningitis. Simultaneous estimation of CRP levels in serum and CSF was found to have a significant diagnostic utility as compared to culture.     

Histopathological study of aorto-coronary bypass grafts with special reference to fibrin deposits on grafted saphenous veins

A histopathological study was performed on 36 patients (60 grafts) who had undergone aorto-coronary bypass graft (ACBG) surgery 0 to 99 months prior to death. The following pathologic changes were found: 1) The thickness of diffuse intimal proliferation in the ACBG progressed with time from graft surgery to death. 2) The media became atrophic and the adventitia was increased slightly in thickness. 3) Fibrin deposits were found in 20 patients on/in the intimal thickenings of the vein graft walls and 7 patients showed incorporated fibrin in the thickened intima even one month after surgery. 4) Atherosclerosis, identified as intimal foam cell accumulation or frank plaques, was seen in only 3 patients 4 years after surgery. Fibrointimal proliferation occurred with relatively greater frequency in patients with fibrin deposits (P less than 0.001). Although it is well known that mural thrombi in vein grafts manifest fibrointimal proliferation, our results suggest that fibrin deposits might be responsible for intimal thickening even one month after graft surgery.     

Vascular leiomyosarcoma: Clinicopathology and immunohistochemistry with special reference to a unique smooth muscle phenotype

Vascular leiomyosarcoma (LMS) is the least frequent type of soft‐tissue LMS and has not been fully evaluated immunohistochemically. The aim of the present study was therefore to examine four cases of vascular LMS, paying special attention to the immunohistochemical expression of smooth muscle markers. All the patients were female; two tumors were located within the inferior vena cava, one within the saphenous vein, and one within the external iliac vein. All the tumors displayed well–moderately differentiated smooth muscle morphology. On immunohistochemistry all four vascular LMS were diffusely and strongly reactive to actins, calponin, and h‐caldesmon, whereas desmin was diffusely stained in one tumor, only focally positive in two, and negative in one. The walls of the blood vessels contiguous to the tumors contained desmin‐ and h‐caldesmon‐positive smooth muscle cells in two cases. In contrast, among 43 non‐vascular LMS (20 well–moderately differentiated and 23 poorly differentiated or other types), 38 were variably positive for desmin, whereas 21 were negative for h‐caldesmon. These findings suggest that the vascular LMS displays a distinctive phenotype of smooth muscle differentiation according to histopathogenesis.     

Role of phospholipase A in multiorgan failure with special reference to ARDS and acute renal failure (ARF)

Summary In 150 patients admitted to an ICU phospholipase A serum activity was measured daily. The correlation between the increase of phospholipase A serum activity and the severity of adult respiratory distress syndrome (ARDS) and the incidence of acute renal failure (ARF), two important target systems in multiple organ failure (MOF) syndrome was studied as well as the efficacy of a treatment with phospholipase A inhibitors (methylprednisolone and dexamethasone). The results of this study show that there exists a statistically significant correlation between the increase of phospholipase A activity and the incidence of multiple organ failure. Inhibitory treatment ameliorates the organ function for a short time without any change of long-term outcome. The results could not clarify whether the rise of the mother enzyme of the arachidonic acid metabolism is only an epiphenomenon of multiple organ failure or the causative agent itself.     

Some histological and metabolic properties of an isolated perfused rat brain preparation with special reference to monoamine metabolism

A method is described for perfusing the rat head which results in perfusion of the brain, its covering and the bony skull only. Dye and latex injection studies showed that there was no perfusion of extracranial tissue and thus it was not necessary to remove the lower jaw and facial tissues as described by previous authors. Perfusion with fluorescein demonstrated that the whole brain was perfused. Light microscopy after two hours of perfusion revealed no deterioration in brain-structure. Electron microscopy showed a small increase in the extracellular space and the perivascular space with good preservation of subcellular organelles. Glucose and acetoacetate removal were very similar to those reported for the adult rat in vivo as measured by arterio-venous differences. The concentrations of 5-hydroxytryptamine, dopamine and noradrenaline are maintained at values close to those in vivo during a 2-hr perfusion with a basal medium and the preparation will maintain linear rates of 5-hydroxytryptamine synthesis for 2 h when the medium contains L-tryptophan and tranylcypromine, at rates similar to those measured in vivo. The rate of uptake of L-tryptophan into the brain is similar to that reported after L-tryptophan loading in vivo. The histological and metabolic properties of the preparation are close to those observed in vivo. The method could provide a way in which monoamine metabolism in particular could be studied using an experimental model closer in its properties to the in vivo situation than tissue preparations such as slices or homogenates.