Rheumatoid lung disease. (A clinical, physiological and histological study in 33 patients)

Clinical, physiological and histological investigations on lung involvement are reported in 33 rheumatoid patients. The clinico-pathological patterns of rheumatoid lung disease observed in 19/27 non-smoking female patients were characterized radiologically by diffuse interstitial opacities, functionally by V/Q inequality and microscopically by peribronchiolar and/or alveolar fibrosis. Emphasis is placed on the ventilation/perfusion relationship as well as histopathological studies for a more accurate diagnosis of lung disease in RA. Patients with pulmonary nodules and pleural opacities were also observed. A possible immunological aetiology is suggested on the basis of the simultaneous finding of IgG, complement and fibrinogen in the pulmonary tissue.

[Particular ultrastructural aspects of human Paneth's cells]

Our research is about the ultrastructural aspects of Paneth cells obtained from human jejunal mucosa. The cells appear columnar in shape and show a roundish nucleus; their cytoplasm is characterized by a great amount of R.E.R. and by typical large granules in sopranuclear position. Our results confirm those previously described by other authors about the morphology of Paneth cells. In our specimens we have found moreover a variable number of particular cytoplasmic structures; these may show a fibrillar or granular matrix and are always surrounded by a membrane.

[Some observations on the ultramicroscopic organization of specialized connections amongst nervous fibres in the inferior olivary nucleus of the cat]

Some observations have been made on inferior olive specimens in the adult cat, with aldehydes fixation techniques through vascular perfusion suitable for electron microscropy. The results made it possible to recognise five types of vesicular structures present in different nerve endings (differences either in type or in number). A possible topographic organization of synaptic connections, between the afferent endings and the dendritic structures of the inferior olive has been considered and it seems that on every large dendrite, nearer the cell body, there is a development of numerous connection. As such connections give a great deal of information to the dendrites with much much interaction it seems possible that there is modulation in the activation of the postsynaptic element. On the other hand, in the periphery of the dendritic branch, many thin branches seem to make contact with few and large endings; this leads us to believe that the regulations of the information is not based only on the afferences but mainly on distribution, origin and number of the postsynaptic elements. A study of the interdendritic connections and of tubulo-vesicular structures showed that their diameter and dense content have a similar morphology with the big granulated vesicles, visible in the terminals, or along the fibres or, frequently, in the Golgi apparatus.

Ultrastructural pathology of solid tumours

Electron microscopy demonstrates solid tumours can be subdivided in two groups; those with or those without junctions. The submicroscopic details useful for the identification of the histogenesis of the tumour cells have been briefly described for each of these groups.

Ultrastructural appearance of malignant non-Hodgkin's lymphomas and lymphoid leukemias

In this report the authors show the main ultrastructural features of malignant non-Hodgkin's lymphomas and lymphoid leukemias, trying to outline the more important findings useful to diagnostic purpose. Since, from an immunologic point of view, lymphoid malignancies reflect the main steps of normal B and T ontogenesis, the various tumours are progressively presented in relation to their stage of phenotypic differentiation. An exact knowledge of the potential information from electron microscopy and its intrinsic limitations, including the high cost and the time expense, permit a correct use of this investigation in diagnostic procedure in lymphoid malignancies.

Electron spectroscopic imaging of secretory granules in human eccrine sweat glands

A study of human eccrine sweat glands by electron spectroscopic imaging has been performed. A high nitrogen content in secretory granules of the dark mucous cells has been found while mucous cells in the digestive or respiratory systems did not contain nitrogen detectable in our experimental conditions. High concentrations of nitrogen were found in zymogenic granules and in the core of the granules in the eosinophilic leucocytes. Our findings seem to suggest that the granules of the dark secretory cells are composed not only of mucoid substances but contain also high concentrations of proteins. The descriptive term "granulated cells" seems to be more correct than "mucous cells" to indicate these elements.

Human thymocyte differentiation: an ultrastructural study using monoclonal antibodies and immunogold staining method

The ultrastructural features of normal human thymocytes were analyzed at various stages of immunologic differentiation as defined by a panel of OKT monoclonal antibodies visualized by colloidal gold labelled antimouse IgG. The study shows that first stage thymocytes (OKT10+, OKT9+) have a typical morphology not found in more mature stages and describes the critical ultrastructural change which they undergo in becoming second stage thymocytes (OKT10+, OKT6+, OKT8+, OKT4+). No change in thymocyte fine morphology has been found in the progression from second to third stage (OKT10+, OKT3+, OKT8+ or OKT10+, OKT3+, OKT4+). Cells with ultrastructural features intermediate between those of the first and second stage have been found to react with monoclonal antibodies characterizing the first and the second stage. Ultrastructural similarity and homogeneity found in OKT8+ and OKT4+ thymic subpopulations suggests the acquisition by T lymphocytes of morphologic structures correlate with immunologic features previously found in peripheral blood T cell subpopulations to be a post-thymic process.

Immunoelectron microscopy with immunogold staining method and monoclonal antibodies. A promising tool in ultrastructural study of lymphatic subpopulations

The immunogold staining method has been recently introduced and proved to be of interest in immunoelectron microscopy as a tracer for detection of cell surface antigens defined by monoclonal antibodies in leukocytes. As variations in sample manipulations and different distribution patterns of gold particles in positive cells are reported, the authors described the experimental conditions which permit them to obtain a good and well interpretable labelling in peripheral blood lymphatic cells. In order to verify the sensitivity and the specificity of this labelling and the interpretation of positivity, a comparison between the percentages of positive cells obtained in electron microscopy and immunofluorescence has been reported. The correlation is acceptable and since the ultrastructural details are also well preserved, this method seems promising for the comparison of molecular phenotypic characteristics and submicroscopic appearance of lymphatic cells.

T lymphocytic subpopulations of normal human peripheral blood defined by monoclonal antibodies: an ultrastructural study using immunogold staining method

Submicroscopic findings of T lymphocytic subpopulations of normal human peripheral blood defined by OKT monoclonal antibodies were studied using ultrastructural immunocytochemistry (immunogold staining). The results show that OKT4-and OKT8-positive lymphocytic subpopulations have a distinct morphological pattern, although some variations in the ultrastructural details of cells in each subset are evident. The most representative features of OKT8-positive cells are regular or slightly indented nucleus with condensed chromatin, abundant cytoplasm, prominent Golgi apparatus, several granules frequently localized in the Golgi area, and numerous mitochondria, often in cluster disposition. OKT4-positive cells show generally less condensed chromatin, scanty cytoplasm and poor organule pattern. Furthermore, positive lymphocytes with prominent nuclear irregularities are found in both lymphocytic subpopulations. Ultrastructural similarities between the T cell subsets phenotypically characterized by monoclonal antibodies and other immunological criteria are also discussed.