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A case of crystal-storing histiocytosis (CSH) associated with mucosa-associated lymphoid tissue (MALT) lymphoma of orbit is reported. The patient was a 53-year-old man who presented with an 8-year history of a slowly enlarging tumor in his right orbit. Histopathologic examination revealed that the tumor was composed predominantly of sheets of spindle-shaped cells resembling striated muscle cells and scattered aggregates of atypical lymphoid cells, showing prominent plasmacytoid differentiation. Immunohistochemical analysis demonstrated that the spindle-shaped cells were CD68-positive histiocytes containing abundant crystals in their cytoplasm, consistent with the diagnosis of CSH. The aggregates of atypical lymphoid cells were diagnosed as MALT lymphoma based on their immunophenotype. Although CSH is a well-recognized manifestation in lymphoproliferative disorders, CSH complicated by MALT type of ocular adnexal lymphoma has rarely been reported. Given the rarity of this, every case presenting with such crystal-storing histiocytes warrants a thorough search for a hidden lymphoid dyscrasia.

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PURPOSE: To employ Mie scattering theory to predict the light-scattering from micrometer-sized particles surrounded by lipid shells, called multilamellar bodies (MLBs), reported in human age-related nuclear cataracts. METHODS: Mie scattering theory is applicable to randomly distributed spherical and globular particles separated by distances much greater than the wavelength of incident light. With an assumed refractive index of 1.40 for nuclear cytoplasm, particle refractive indices from 1.33 to 1.58 were used to calculate scattering efficiencies for particle radii 0.05 to 3 microm and incident light with wavelengths (in vacuo) of 400, 550, and 700 nm. RESULTS: Surface plots of scattering efficiency versus particle radius and refractive index were calculated for coated spherical particles. Pronounced peaks and valleys identified combinations of particle parameters that produce high and low scattering efficiencies. Small particles (<0.3 microm radius) had low scattering efficiency over a wide range of particle refractive indices. Particles with radii 0.6 to 3 microm and refractive indices 0.08 to 0.10 greater (or less) than the surrounding cytoplasm had very high scattering efficiencies. This size range corresponds well to MLBs in cataractous nuclei (average MLB radius, 1.4 microm) and, at an estimated 4000 particles/mm(3) of tissue, up to 18% of the incident light was scattered primarily within a 20 degrees forward cone. CONCLUSIONS: The calculated size of spherical particles that scatter efficiently was close to the observed dimensions of MLBs in cataractous nuclei. Particle refractive indices only 0.02 units different from the surrounding cytoplasm scatter a significant amount of light. These results suggest that the MLBs observed in human age-related nuclear cataracts may be major sources of forward light scattering that reduces contrast of fine details, particularly under dim light.

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In this study, we are concerned with the 237 isotope of neptunium (237Np), which is a by-product of uranium in nuclear reactors. To study ultrastructural lesions induced by this element, a group of rats were injected with a solution of 237Np-nitrate once a day for 14 weeks. Lesions observed in liver and kidney are described using electron microscopy. Ultrastructural alterations of cellular membranes and intracellular organelles demonstrated the existence of neptunium toxicity. This toxicity was characterized by various lesions, such as cytoplasmic clarification, disappearance of mitochondrial cristae, swollen mitochondria, abnormal condensation of nuclear chromatin, and nuclear fragmentations. This study demonstrated the probable induction of apoptosis by neptunium both in liver and kidneys.

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The paper presents morphological, morphometric and densitometric evidence obtained on cytoplasmic inclusions of alveolar macrophages from bronchoalveolar lavage of chronic obstructive bronchitis (COB) sufferers. All of them previously worked in the zone contaminated after the Chernobyl accident. The control consisted of nonexposed to radiation COB patients. In the exposed subjects alveolar macrophages were more active, 20% of cytoplasm was occupied by numerous phagolysosomes varying in form. Their densitometric evaluation has been performed. Further bronchoalveolar lavages will be conducted to follow up the above changes in alveolar macrophages.

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The influence of continuous light or darkness on the large granulated vesicles in sympathetic nerve fibers of the mouse pineal was investigated by means of quantitative electron microscopic techniques. Continuous illumination at about 20 lux caused the disappearance of the diurnal rhythm in the number of the large granulated vesicles, followed by an accumulation of these vesicles. The diurnal rhythm of the large granulated vesicles was abolished in mice kept in continuous darkness for 7 days. These results suggest that the diurnal variation of the large granulated vesicles may be controlled directly by environmental light. Based on these findings, the relationships between small and large granulated vesicles were discussed.

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Transplantable murine neuroblastoma C 1300 was studied ultrastructurally at varying time intervals ranging from 2 hours to 40 days before and after X-irradiation. Following X-irradiation, 2000 and 4000 rads in a single dose, the uniformly small tumor cells became progressively enlarged multinucleated and degenerated, starting at one to two days. At five to seven days, the uni- and multinucleated giant cells predominated over the small tumor cells, while the giant cells progressively disappeared therafter and the small tumor cells predominated over the giant cells at 10 to 14 days. The giant cells contained abundant subcellular organelles and the X-irradiated tumor cells apparently continued to produce the organelles until they degenerated. Two types of cytoplasmic particles, intracisternal A and bar-shaped, were observed in the tumor cells. The intracisternal A particles occurred in almost all non-irradiated tumor cells though their number varied considerably from cell to cell, while they were observed less frequently in the radiation-induced giant cells probably due to a dilution effect rather than an actual numerical decrease. The bar-shaped particles, hitherto undescribed in the neuroblastoma, were 23 nm in diameter, variable in length and occasionally tubular. They occurred only in degenerating cells regardless of X-irradiation but were encountered more frequently in irradiated tumors than in non-irradiated ones. It is suggested that they may represent an unknown degenerative product of cytoplasm and/or nucleus rather than virus particles, despite their morphological resemblance to certain virus particles.

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