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At least 721 records · Page 40Linked to original sources
PubMed1982

Functional hyposplenia after splenic irradiation for Hodgkin's disease.

We previously reported a patients who developed fulminant pneumococcal sepsis 12 years after successful treatment for Hodgkin's disease, which included splenic irradiation. We have since evaluated splenic size and function in 25 patients who had received splenic irradiation 5 to 16 years previously either for Hodgkin's disease (n = 19) or non-Hodgkin's lymphoma (n = 6). Mean maximum splenic diameter as measured on a 99mTc-sulfur colloid liver-spleen scan was 6.2 cm in the irradiated group and 9.7 cm in a control group (p less than 0.001). The mean percentage of erythrocytes containing pits when observed with interference phase microscopy was 13.0% in the irradiated group, which was significantly different (p less than 0.001) from the levels found in each of the control groups: normal subjects, 0.9%; unstaged and untreated lymphoma patients, 0.6%; and patients after splenectomy, 33.7%. Patients who have had splenic irradiation should be considered at risk of developing overwhelming pneumococcal sepsis.

Adolescent↗
PubMed2000

Inherited macrothrombocytopenia with distinctive platelet ultrastructural and functional features.

We report a family with inherited macrothrombocytopenia and characteristic large membrane complexes in the platelets. Two affected subjects had platelet counts of 40 and 65 x 10(9)/L respectively as assessed by contrast phase microscopy. Ultrastructural studies revealed giant spheroid platelets with characteristic large membrane complexes and/or giant vacuoles containing platelet organelles. Immunohistochemical studies of actin and tubulin showed a disorganization of the microtubule and actin systems. These abnormalities were absent in leukocytes, indicating a platelet-specific cytoskeleton disorder. Platelet autoantibodies were repeatedly absent. Nevertheless, in the peripheral blood we observed several figures of platelet phagocytosis by macrophages and neutrophils. The in vitro aggregometric response of platelets to ADP, collagen, thrombin, ristocetin was present, but shape change was absent. The urinary excretion of thromboxane A2 metabolites of the affected subjects were approximately 2 standard deviations above control values, in spite of a reduced maximal biosynthetic capacity of thromboxane from giant platelets assessed in vitro during whole blood clotting. This inherited platelet disorder shows structural and functional features which allow to distinguish it from other syndromes associated with giant platelets. We also propose to include ultrastructural and cytoskeletal studies in the diagnosis as well as in the classification of inherited giant platelet disorders.

Blood Platelets↗
PubMedDate not supplied

[Mucolipidosis. biologic characteristics (author's transl)].

Mucolipidosis II is a severe inherited lysosomal storage disease characterized by profound psychomotor retardation, severe Hurler-like skeletal changes and normal urinary mucopolysaccharide excretion. Mucolipidosis II is a related disorder distinguished by its milder course, milder to absent mental retardation and survival to adult life. Cultivated fibroblasts from patients with both of these disorders display large inclusions on phase microscopy and reduced levels of many acid hydrolases. However, culture medium fibroblasts out the body fluids of affected patients show enormously elevated levels of these hydrolases. The lysosomal enzyme activities in serum, leukocytes, fibroblasts extracts and culture medium from seven patients with mucolipidosis II are similar to those found in four cases of mucolipidosis III. The findings of excessive excretion of sialyl-oligosaccharide in urine and of increased level of sialic acid compounds in cultured fibroblasts associated with a sialidase deficiency in leukocytes, fibroblasts and serum are discussed.

Child, Preschool↗
PubMed1975

Hairy cell leukemia: functional, immunologic, kinetic, and ultrastructural characterization.

A diagnosis of hairy cell leukemia was made by optic microscopy, phase-contrast microscopy, electron microscopy, scanning microscopy, and histochemistry of the abnormal blood cells. In vivo these cells were found to have a half-time in the blood of approximately 150 hr. In vitro they had the capacity to adhere firmly to plastic, making it possible to obtain a pure population of hairy cells. Neither T-rosette formation nor phytohemagglutinin (PHA) transformation could be demonstrated in these cells. On the other hand, the presence of immunoglobulins on the surface of the hairy cells (HC) by immunofluorescence, and the synthesis and secretion by these cells of IgM type lambda-chains shown by radioimmunodiffusion, were in favor of their B-type lymphocyte origin. Similarities to chronic lymphocytic leukemia were apparent.

Bone Marrow↗
PubMed2000

[Effects of GDNF on primary culture of spinal cord neurons].

The effect of GDNF on long-term cultured spinal cord neurons was studied. GDNF could promote spinal cord neurons survival after 7 d or 14 d culture by MTT assay. The effect of GDNF on growth cones, neuron soma magnitude, neurite length and spines formulation of spinal cord neurons in cell culture was observed by phase microscopy, Nissl stain and NSE immunocytochemistry stain. The results indicated that GDNF had significant trophic effects on long-term cultured spinal cord neurons.

Animals↗
PubMed2005

Nanoparticles for gene delivery to retinal pigment epithelial cells.

PURPOSE: To evaluate the safety and potential use of poly(lactic) acid (PLA) and poly(lactide-co-glycolide) (PLGA) nanoparticles (NPs) as vectors for gene transfer to RPE cells. METHODS: Experiments were conducted with primary bovine RPE cells and with the ARPE-19 human RPE cell line. Rhodamine loaded NPs were used to study factors influencing the internalization process by the various RPE cells: concentrations of NPs, duration of contact time, stage of cell culture and ambient temperature. The extent of NPs internalization was evaluated by fluorescence and phase microscopy. Potential NP toxicity was measured by the trypan blue exclusion dye test and the MTT method. Green fluorescent protein (GFP) plasmid or red nuclear fluorescent protein (RNFP) plasmid were sequestered in NPs. The ability ot these "loaded" NPs to generate gene transfection and protein expression in RPE cells was assessed both in vivo and in vitro by fluorescence and confocal microscopy. RESULTS: The extent of NP internalization in cultured cells increases with their concentration reaching a plateau at 1 mg/ml and a contact time of up to 6 h. Temperature and culture stage did not influence the in vitro internalization process. No toxic effects on RPE cells could be detected when these were incubated with up to 4 mg/ml of NPs. In human and bovine RPE cells incubated with GFP loaded NPs, cytoplasmic green fluorescence was observed in 14+/-1.65% of the cultured cells. Incubation with RNFP loaded NPs yielded a nuclear red fluorescence in 18.9+/-1.6% of the cells. These percentage levels of expression initially detected after 48 h of incubation remained unchanged during the following 8 additional days in culture. No significant differences in the extent of cytoplasm or nuclear fluorescence expression were observed between bovine or human RPE cultured cells. In vivo, a preferential RNFP expression within the RPE cell layer was detected after intra vitreous injection of RNFP plasmid loaded NPs. CONCLUSIONS: The ability of PLGA NPs to sequester plasmids, their nontoxic characteristics, and rapid internalization enables gene transfer and expression in RPE cells. These findings may be of potential use when designing future gene therapy strategies for ocular diseases of the posterior segment.

Animals↗
PubMed1979

Melanoma development from subcellular fractions.

Amelanotic melanoma cells, RPMI-1846, were disrupted by sonic energy which caused cell membrane disruption, thereby allowing liberation of viable cellular organelles. These subcellular particles were injected into syngeneic Syrian and nonsyngeneic hamsters in six separate experiments to determine their possible growth potential. A sizable number of the injected hamsters subsequently died as a result of melanoma. In an attempt to be as certain as possible that no whole melanoma cells were injected with sonicated melanoma material, various techniques were used including collodian sections for debris analysis, phase microscopy and electron microscopy. Results of this study suggested that melanoma can be induced from particles within the melanoma cell which are liberated following cell membrane disruption. It appears that a mechanism exists for the transfer of oncogenic information that may not be dependent upon the presence of intact cells or require the participation of a viral agent.

Abdominal Muscles↗
PubMed1991

[Hairy cell leukemia expressing SIgM+, SIgG-, CD11b+ and CD21+ and accompanying lymphadenopathy without splenomegaly].

Hairy cell leukemia (HCL) expressing both surface monocytoid antigen and IgM (kappa) was reported. A 62-year-old male was admitted to our hospital in September 21, 1989 because of leukocytosis. Physical examinations showed axillary and inguinal lymphadenopathy but no hepato-splenomegaly. The leukocyte count was 12,600/microliters with 73% of abnormal cells like large lymphocytes which had abundant cytoplasm and hairy appearance under phase microscopy. They had ruffles with microvilli under electron microscope. Bone marrow puncture showed normocellular marrow with 71.2% of abnormal cells similar to the peripheral blood. Surface markers were CD11b+, CD21+, HLA-DR+, Tac- and IgM (kappa). They were positive for ++acid phosphatase staining, but negative for peroxidase and tartrate-resistant acid phosphatase staining. He was diagnosed as Japanese type HCL. HCL expressing both surface monocytoid antigen and IgM is rare and the clinical features of our case are compared with those reported in Japan.

Antigens, Differentiation, B-Lymphocyte↗
PubMed1990

Amiodarone-induced injury of human pulmonary artery endothelial cells: protection by alpha-tocopherol.

Amiodarone is a potent antidysrhythmic drug that is associated with severe pulmonary toxicity. The mechanism of amiodarone pulmonary toxicity is poorly understood. To investigate the possible involvement of oxygen-derived metabolites in amiodarone-induced injury, 51Cr-labeled human pulmonary artery endothelial (HPAE) cells were incubated with amiodarone for 18 hr in the presence of various antioxidants and in hypoxic and hyperoxic conditions with cell injury quantified by 51Cr release, expressed as cytotoxic index. Amiodarone (10-50 microM) directly injured HPAE cells in a concentration-dependent manner, but the injury was not modulated by altering ambient oxygen concentrations. Furthermore, amiodarone-induced injury (30 microM) was not reduced by the following antioxidants: catalase, superoxide dismutase, ascorbic acid, dimethyl sulfoxide and ethanol. In contrast, toxicity from 30 microM amiodarone was significantly reduced by alpha-tocopherol (alpha-TOC) at 10, 20 and 40 microM from a cytotoxic index of 41.6 +/- 3.5 to 25.5 +/- 7.9, 10.61 +/- 5.4 and 3.1 +/- 2.8, respectively. As revealed by phase microscopy, alpha-TOC (40 microM) prevented any evidence of toxicity to the amiodarone-treated cells. Amiodarone concentrations in the HPAE cells incubated in the presence and absence of alpha-TOC were not significantly different, indicating that alpha-TOC did not interfere with the uptake of the drug by the cells. Similarly, amiodarone did not interfere with the uptake of alpha-TOC by the HPAE cells. Although the specific mechanism of action remains unclear, alpha-TOC affords nearly complete protection in vitro from the cellular injury induced by amiodarone.

Amiodarone↗
PubMed1987

Gambierdiscus toxicus in gut content of the surgeonfish Ctenochaetus strigosus (herbivore) and its relationship to toxicity.

Flesh of surgeonfish, Ctenochaetus strigosus, obtained from corresponding catches of C. strigosus implicated in ciguatera poisoning outbreaks was examined for ciguatoxin and related polyethers by the stick test enzyme immunoassay. Simultaneously, gut contents of the fish were examined under phase microscopy for the presence of Gambierdiscus toxicus. Eighty-seven per cent of the fish were stick EIA positive, while 98% were positive for G. toxicus in gut contents. The data obtained suggest a relationship between G. toxicus in gut content and tissue toxicity levels. This is in agreement with previous studies which demonstrated a relationship between G. toxicus in fish gut content and toxicity of the flesh to animals and humans.

Animals↗
PubMed1989

Effects of glia-conditioned medium on primary cultures of central neurons.

The effects of glia conditioned media on the survival and differentiation of embryonic neuron cultures of the Central Nervous System is described. We established glial cultures of peritumoral areas and the culture medium was changed serially and collected as glia conditioned medium (GCM). Neuron enriched cultures plated on poly-L-lysine coated Petri dishes and after 4 days in vitro, the neuronal cultures were treated for the inhibition of glial cells. We established two groups of neuronal cultures that were respectively exposed to the GCM and to conventional culture medium. We evaluated the survival and differentiation of neuronal population in each group of cultures by contrast-phase microscopy and cellular uptake of Horse Radish Peroxidase. The cell cultures exposed to GCM showed a survival during the in vitro stages and an organization and differentiation pattern of mature neurons larger than the control cultures. This fact suggests that the glial cultures produce a diffusible neurotrophic factor that influences the neuronal response in vitro.

Cell Differentiation↗
PubMed1989

[Growth and contractility of cells from diabetic pre-retinal membrane in primary tissue culture].

Cells grew out in tissue culture from 7 out of 12 diabetic pre-retinal membrane specimens. Cell types of epithelium, glia, macrophage, blood vessel, and fibroblast-like cells were distinguished by inverted phase microscopy, electron-microscopy and immunostaining. Electron-microscopy demonstrated abundant cytoplasm fibrils in some of the cells, and immunostaining for actin showed great variation in the intensity of staining. An Mg++ ATP contraction assay on 81 detergent-treated cells revealed a 25% average reduction in the cell area. Immunostaining for cytokeratin and GFAP following the Mg++ ATP assay showed no significant difference in cell contraction among epithelial, glial and other cells. The role of fibroblast-like cells and the contraction of pre-retinal membrane were discussed.

Actins↗
PubMed1988

The Wistar Furth rat: an animal model of hereditary macrothrombocytopenia.

The mechanisms that determine and regulate platelet size are unknown. By phase microscopy, we observed that Wistar Furth (WF) rats had macrothrombocytopenia. In this study, we have characterized and compared platelets and megakaryocytes of WF rats with those of Wistar, Long-Evans hooded (LE), and Sprague-Dawley rats. In addition, we have examined the mode of inheritance of this WF rat platelet abnormality. The average platelet count of WF rats was only one-third that of the other three rat strains. In contrast, the mean platelet volume (MPV) of adult WF rats was twice that of the other rat strains; however, the average megakaryocyte diameter and DNA content distribution of WF rats were not significantly different from those of LE rats. The average megakaryocyte concentration was 30% lower in the WF strain compared with that of LE rats. Mazelike membrane formations were observed in WF platelets and megakaryocytes by electron microscopy. Reciprocal crosses of WF and LE rats resulted in offspring with MPVs and platelet counts like those of LE rats, indicating that the macrothrombocytopenic trait is recessive in its inheritance. Reciprocal marrow transplants between the WF and LE strains resulted in MPVs like those of the donor strain, demonstrating that the macrothrombocytopenia is an intrinsic marrow abnormality of the WF strain. Splenectomy did not alter the MPV of WF rats. The response of WF megakaryocytes and platelets to severe, acute thrombocytopenia was similar to that of LE rats except that the shift to higher megakaryocyte DNA contents was muted and platelet recovery was slower in the WF rats. In summary, the WF rat has a hereditary macrothrombocytopenia that is recessive in nature and not due to differences in megakaryocyte size or DNA content. These results suggest that the macrothrombocytopenia of WF rats results from the formation of fewer platelets per megakaryocyte, possibly resulting from a qualitative or quantitative defect in some component necessary for proper subdivision of megakaryocyte cytoplasm into platelets.

Age Factors↗
PubMed1987

[Urinary sediment in acute renal failure].

Over a one-year period, 31 episodes of acute renal failure in children have been studied for urine sediment by contrast phase microscopy (maintained diuresis: 15, oligoanuria: 16, dialysed patients: 9). The etiologies of acute renal failure were: sepsis = 8; nephrotoxicity = 7; hemolytic uremic syndrome = 5; acute nephritic syndrome = 3; hemodynamical changes = 4; obstructive renal failure = 2; others = 3; acute rejections after renal allograft were excluded. The first urine sediment examination was performed 5 days after the onset of renal failure, and has been controlled in 11 children. In 28 cases (90%), there was a good correlation between clinical, biological, ultrasonographic and pathological (4 cases) data. The mechanism of renal failure has been determined by urine sediment examination in most cases, sometimes allowing to rectify a previous diagnosis. The value of this examination seems to be more of anatomoclinical than of prognostic interest, mainly for definite (hemolytic uremic syndrome) or polyfactorial (oncohematological diseases) renal dysfunctions.

Acute Kidney Injury↗
PubMed1986

Renal vein entrapment syndrome: frequency and diagnosis. A lesson in conservatism.

Two boys investigated for gross hematuria and left loin pain were found on ultrasound (US) to have left renal vein (LRV) entrapment associated with isomorphic urinary red blood cells, but normal renal venograms. Over the next 18 months ten children with gross hematuria were investigated and two more boys were discovered with the LRV entrapment syndrome, i.e., isomorphic red cells and a diagnostic US. Venography has a low yield in detecting renal venous compression, and since urinary red cell morphology may localize the origin of renal bleeding, we strongly recommend simple procedures, i.e., phase microscopy and renal US to evaluate all cases of hematuria before employing invasive or radiation dependent investigations. Since there is a range of LRV compression and associated dilatation in asymptomatic patients, strict criteria must be applied to diagnose renal vein entrapment.

Adolescent↗
PubMed1986

Different effects of aspirin, dipyridamole and UD-CG 115 on platelet activation in a model of vascular injury: studies with extracellular matrix covered with endothelial cells.

Cultured endothelial cells produce an extracellular matrix (ECM) which activates platelets, similarly to deendothelialized vascular segments. Platelet-rich plasma (PRP) was incubated with endothelial cells cultures seeded in various densities on ECM. The interaction of the platelets with this artificial intima was evaluated by phase microscopy and by thromboxane A2 (TXA2) and prostacyclin (PGI2) measurement. Large platelet aggregates were formed on exposed ECM. Platelets aggregation but not adhesion on the ECM was markedly inhibited by the presence of endothelial cells. Pretreatment of the endothelial cells with 0.1 mM aspirin reduced their PGI2 synthesis and was associated with platelet aggregation on the ECM. 10 microM dipyridamole markedly inhibited platelet activation by ECM when the drug was added to citrated whole blood before PRP preparation. UD-CG 115 which elevates cyclic AMP in cardiac muscle, inhibited platelet aggregation and TXA2 production induced by ECM, in the presence as well as in the absence of endothelial cells, without any effect on endothelial PGI2 production.

6-Ketoprostaglandin F1 alpha↗
PubMed1987

Microbiological and pharmacokinetic evaluation of cefonicid, a long-acting cephalosporin.

The in vitro antimicrobial activity of cefonicid has been tested against 27 recent clinical isolates of 7 different species (S. aureus, E. coli, K. pneumoniae, P. mirabilis, S. marcescens, E. cloacae and P. aeruginosa) using the MS-2 Research System, contrast phase microscopy and the colony forming unit assay. With the exception of P. aeruginosa, S. marcescens and E. cloacae, cefonicid showed excellent activity against the different bacterial species tested (i.e. S. aureus, E. coli, K. pneumoniae and P. mirabilis). Tissue penetration of cefonicid after a single i.m. or i.v. dose (1 or 2 g, respectively) was also studied using the suction blister method. In 14 adult subjects with normal renal and liver functions, cefonicid plasma half-life was 5.1 and 5.4 h following i.v. and i.m. administration. Drug concentrations achieved at peak in plasma and suction blister fluid were higher than the minimum inhibitory concentrations for most sensitive pathogens and remained above these values for 24 h. These data support the use of a single daily dose regimen of cefonicid, both i.v. and i.m., for the treatment of most common infections caused by sensitive pathogens in blood and tissues.

Bacteria↗
PubMed1985

Prostacyclin production by cultured endothelial cell monolayers exposed to step increases in shear stress.

While fluid shear stress is an important cardiovascular factor in vivo, it has generally been ignored in in vitro assays of endothelial cell function. We quantified the influence of shear stress on the production of prostacyclin by confluent monolayers of bovine aortic endothelial cells placed in a lucite flow chamber and exposed to flowing culture medium at constant shear stress at 37 degrees C and pH 7.4. Continuous inverted-phase microscopy (x 300) of the monolayers showed no significant contraction or detachment of cells under these conditions. Step increases in shear stress from zero to 14 dyne/cm2 caused rapid rises in prostacyclin production, from a baseline (n = 4) of 0.17 +/- 0.062 ng/cm2.min (mean +/- SEM) to peak values within 2 minutes, followed by a decline over several minutes. Peak prostacyclin production increased (p less than 0.005) with shear stress, from 0.60 +/- 0.13 ng/cm2.min at 0.9 dyne/cm2 (n = 14) to 2.33 +/- 0.67 ng/cm2.min at 14 dyne/cm2 (n = 10). The time integral of production or total production, however, did not significantly change with shear stress at least for shear stresses above 0.9 dyne/cm2. Once stressed, cell monolayers produced additional prostacyclin in response to stimulation by Na arachidonate or the calcium ionophore A23187, but not to repeat mechanical stimulation. We conclude that endothelial cells produce bursts of prostacyclin in response to suddenly imposed arterial-like shear stress, and that the peak rate, but not the time integral, of this production increases with shear stress.

Animals↗