In vitro and in vivo uptake of nickel sulfides by rat lymphocytes

The uptake, the biological transformation and the interaction with cellular constituents of Ni₃S₂ and NiS have been studied in vitro and in vivo on rat lymphocytes. NiS crystals are phagocytized in vitro and no structural degradation is observed within the first 3 days of exposure. Energy dispersive spectrometry (EDS) reveals a slight dissolution characterized by the loss of sulfur. Ni₃S₂ is degraded in the extracellular space to minute particles (50–100 nm) covering the cell membrane. Smaller intracellular particles (10–30 nm) are found selectively bound to mitochondria, endoplasmic reticulum, Golgi vesicles, nuclear membranes, and the euchromatinic part of nuclei. EDS analyses reveal that the particles bound to cell membranes and euchromatin no longer contain sulfur but phosphorus and nickel as inorganic compounds. This observation suggests the formation of a Ni/P complex with the phosphate groups either of membranous phospholipids or of nuclear RNA or DNA. A similar uptake and transformation process of Ni₃S₂ is observed on lymphocytes after in vivo incubation. This leads us to consider lymphocytes as target cells, as compared with other cell types where the Ni₃S₂ uptake occurs only partially. The present findings show a difference of uptake and biological transformation between Ni₃S₂ and NiS. The identical results obtained after in vitro and in vivo bioassays enhance the in vitro experiments, at least for this cell type.     

Relationship between right ventricular ejection fraction and pulmonary pressure in man]

This clinical study analysed the changes in right ventricular ejection fraction induced by changes in right ventricular afterload using a new thermodilution catheter linked to a rapid response computer which allowed instantaneous measurements of the right ventricular ejection fraction. The first group comprised 16 patients referred for coronary angioplasty with single vessel disease (isolated proximal stenosis of one of the two main branches of the left coronary artery) and a normal left ventricular ejection fraction (> or = 55%) and mean pulmonary artery pressure of < 25 mmHg: right ventricular ejection fraction and mean pulmonary artery pressure were measured under basal conditions and after 60 seconds' coronary occlusion with the balloon catheter in order to assess the effects of the reactional increase in afterload on the right ventricular ejection fraction. The second group comprised 11 patients with dilated primary cardiomyopathy with decreased left ventricular ejection fraction (< 50%) and mean pulmonary artery pressure > or = 25 mmHg: the right ventricular ejection fraction and mean pulmonary artery pressure were measured under basal conditions and after intravenous trinitrin (performed to evaluate the pulmonary reaction to vasodilators) in order to analyse the effects of the reduction of afterload on right ventricular ejection fraction. Negative linear correlations were observed between the right ventricular ejection fraction and mean pulmonary artery pressure under basal conditions (r = -0.72; p < 0.005) and between the right ventricular ejection fraction and mean pulmonary artery pressure after changing the conditions of afterload (r = -0.82; p < 0.005).(ABSTRACT TRUNCATED AT 250 WORDS)     

Acral myxoinflammatory fibroblastic sarcoma: a report of two cases

Acral myxoinflammatory fibroblastic sarcoma is a rare low-grade malignant soft tissue tumor, usually observed in the extremities of middle-aged adults. We report two cases which occurred in the thumb and knee of middle-aged women. Both tumors showed a multinodular architecture, with cellular areas, occasional foci of hyalinized fibrosis, and hypocellular areas with a myxoid background. Various neoplastic cells were identified including spindled or rounded epithelioid cells and occasional bizarre giant cells, morphologically mimicking Reed-Sternberg cells or ganglion cells. Tumor cells were strongly immunoreactive for vimentin, and variably positive for CD68 and CD34. Both tumors were completely resected and patients were free of disease without any further treatment after a mean follow-up of 14 months.     

Ocular impairment during type II membranoproliferative glomerulonephritis

Membranoproliferative glomerulonephritis type II (MPGN) is characterized by dense deposits within glomerular basal membrane and Bruch's membrane which result in retinal lesions similar to drusens. We observed a 50-year-old patient with chronic renal deficiency who developed central bilateral serous retinopathy with diffuse punctiforme yellow subretinal lesions. Ophthalmoscopic and angiographic aspects led to an MPGN type II diagnosis. Specific posterior segment lesions are described during MPGN type II. Dense deposits concerned both lamina densa of glomerular basal membrane and Bruch's membrane with choriocapillaris. The main ocular complications were central serous chorioretinopathy and choroidal neovascularization. We review the clinical and evolutive aspects of this disease.