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At least 1,171 records · Page 65Linked to original sources
PubMed1990

In vitro toxicity of gentamicin to corneal epithelial cells.

We report morphologic and viability changes in the rabbit corneal epithelium exposed in vitro to gentamicin sulfate. Rabbit corneal epithelial cells (3 x 10(5)) were seeded in replicate 24-well plates at their first in vitro passage, and gentamicin in concentrations of 0, 50, 250, 500, 1,000, or 5,000 micrograms/ml was added to the tissue culture medium beginning 7 days after subculture. By phase contrast microscopy, changes in cell morphologic appearance, particularly increased cytoplasmic granularity, were observed in the 5,000-micrograms/ml groups as early as 24 h after introduction of the drug. At 48 h, similar findings were observed in the 250-micrograms/ml group and at all higher concentrations. The cytoplasmic granularity was not noted in the 0- or 50-micrograms/ml groups. By electron microscopy, these observations correlated with ultrastructural findings of increased accumulations of intralysosomal bodies beginning in the 250-micrograms/ml group after 48 h of exposure to gentamicin. Furthermore, a statistically significant difference (p = 0.001) was demonstrated between the total number of viable cells in the low-dose group (50-micrograms/ml) and the high-dose groups (greater than or equal to 250-micrograms/ml) for exposure periods of 48 h or more. These findings demonstrate aminoglycoside toxicity to corneal epithelial cells in vitro similar to that seen in the human kidney and conjunctiva.

Animals↗
PubMed1986

The microscopic diagnosis of Pneumocystis carinii. An evaluation of the gram, the methylene blue, and the Ziehl-Neelsen procedures.

An assessment of the Gram, the Methylene blue, and the Ziehl-Neelsen procedures in diagnosing Pneumocystis carinii has been performed. By using heat and methanol as fixatives and phase-contrast microscopy we found the procedures valuable in detecting the pneumocysts, especially in the Gram staining. The diagnosis should, however, be confirmed by a re-staining with a specific staining, viz. the toluidine blue 0 or the silver impregnation a.m. Gomori-Grocott. It is additionally shown that the staining a.m. Gomori-Grocott is dependent on the density of the preparation.

Animals↗
PubMed1988

[Assessment of the intensity of lymphocyte blast transformation in the crypts of the palatal tonsils by using DNA cytophotometry].

Cell fractions isolated from lacunae of palatine tonsils with different functional activities were taken from 40 children 6-15 years of age. The cell fractions were examined using vital phase-contrast microscopy, light microscopy of Pappenheim-stained smears and the Feulgen cytophotometry. Lymphocytes with signs of immunological involvement were shown to constitute 95 per cent of the whole cell lacunar population of the active functional tonsils. 35 per cent of lymphocytes, being in different stages of blast transformation, were found. The most intense blast transformation was revealed in patients with tonsil inflammation. 5-13 per cent of lacunar nuclei with DNA content above the diploid level were found in these patients. Some multicellular islets accumulating small lymphocytes, lymphocytes at different stages of blast transformation, and macrophages were revealed to imitate the cooperation of immunocompetent cells. The data obtained can be helpful in the practical surgery of palatine tonsils.

Adolescent↗
PubMed1989

Cytotoxic effects of benzalkonium chloride and chlorobutanol on human corneal epithelial cells in vitro.

By exposing primary cultures of human corneal epithelial cells to a single dose of either benzalkonium chloride or chlorobutanol, evaluated the cytotoxicity of these two preservatives which are commonly used in artificial tear solutions and other topical ophthalmic medications. Control and experimental cultures were analyzed by continuous time-lapse videomicrographic recordings as well as by sequential phase-contrast microscopy. Both benzalkonium chloride at a concentration of 0.01% and chlorobutanol at 0.5% caused immediate cessation of normal cytokinesis and mitotic activity, and epithelial cells degenerated within two hours and eight hours, respectively.

Benzalkonium Compounds↗
PubMed1989

[Use of native microscopic examination of the vaginal flora in the diagnosis of trichomoniasis].

Microscopic diagnosis of vaginal discharge established so far by means of microbial vaginal pictures (MVP) has proved to be insufficient. Phase contrast microscopy has an irreplaceable value in diagnosing vaginal infections transmitted by sexual intercourse. It yields quick and exact diagnosis of the disease, thus providing the possibility to administer treatment addressly and immediately. In equivocal findings and relapses vaginal cultivation is indispensable. In a series of 600 examined women vaginal trichomoniasis was diagnosed in 28.5% of cases. Simultaneous occurrence of other sexually transmitted diseases was recorded in 42% of 171 women infected with Trichomonas vaginalis. In these cases, the course of the disease was markedly altered by the associated infection. The result of MVP was incomplete or false in 26% of the examined women, trichomoniasis failed to be diagnosed in 80 cases.

Animals↗
PubMed1989

[Microscopic hematuria. Semiologic value in urology. Management of microscopic hematuria].

Microscopic hematuria, a frequent cause for consultation, poses a problem regarding its significance. It is essential that a curable pathology is not neglected. In the absence of associated clinical data, nephrological orientation of investigations depends on the study of urinary sediments and phase contrast microscopy. Where there is a urological orientation, half the lesions involve the lower urinary tract; the use of flexible urethrocystoscopy has been a true advance in terms of its simplicity and reliability. When a lesion is demonstrated the question still remains as to whether it is in fact responsible for the microscopic hematuria. It is best to remain prudent when a poorly significant lesion is discovered. Since 20% of microscopic hematurias remain unexplained, how far should one go in the paraclinical investigation and follow up of involved patients?

Adult↗
PubMed1989

Identification of Tritrichomonas foetus in sections of bovine placental tissue with monoclonal antibodies.

Sections of bovine placenta from cases of bovine trichomoniasis were examined for the presence of Tritrichomonas foetus by standard histological methods using phase-contrast microscopy and by indirect immunofluorescence assay (IFA) employing monoclonal antibodies (mAbs) specific for T. foetus. Parasites were identified readily in deparaffinized tissue up to 4 yr old by IFA with 2 mAbs previously shown to bind to the surface of living T. foetus. These results indicated that the IFA provided a rapid and specific method of identifying T. foetus in tissue sections as compared to standard histological methods.

Abortion, Veterinary↗
PubMed1989

[Rapid methods of detection of bacteria in the bile].

Rapid methods are described for assessing the bacterial contamination, using direct phase-contrast microscopy, triphenyltetrazolium chloride (TTC) test, and a standard loop 3 mm in diameter, or by the detection of the biliary 'active' leukocytes and the microflora sensitivity to antibacterial drugs with the use of the TTC test and turbidimetric technique. These methods permit getting an answer in 4-24 hrs, are simple, and do not require special bacteriologic equipment, this recommending them for routine clinical studies.

Bacteria↗
PubMed1985

[Myocardial infarct of effort with normal coronaries. Study of in vivo platelet activation].

Platelet activation may play a part in causing myocardium infarction with angiographically normal coronary arteries. We investigated this possibility by performing ergometric stress testing in a series of 9 patients (Group A) who had suffered myocardial infarction after a violent effort with angiographically documented coronary insufficiency responsible for a stable effort angina (Group B) and 11 healthy subjects (Group C). Blood samples were taken separately before exercise, at the peak of exercise, and during the recovery period. Platelet morphology, a sensitive indication of the degree of platelet activation, was studied by phase contrast microscopy after immediate fixation of the blood. The percentage of non-discoidal platelets presenting with one or several spicules was measured. At the same time, the plasma concentrations of platelet factor 4 (PF4) and beta-thromboglobulin (beta-TG) were measured. At rest, there was no difference in platelet morphology or specific platelet proteins between the 3 groups. At the peak effort, there was a significant increase of the number of morphologically modified platelets in Groups A and B but not in healthy subjects. This platelet activation could not be linked to the presence of myocardial ischaemia because it was found both in patients with a negative maximal exercise stress test (Group A). Finally, no increase of the plasma concentrations of the platelet protein was observed in any of the groups.

Adult↗
PubMed1988

Effects of prolactin on the morphology of cultured rat granulosa cells.

Morphological changes were correlated with biochemical data induced by prolactin (PRL) in cultured rat granulosa cells from large preovulatory follicles. Biochemical results indicated that PRL exerted a significant dose-dependent inhibition in gonadotrophin-induced secretion of progesterone and 17 beta-oestradiol. PRL alone failed to affect basal steroidogenic secretion. In parallel morphological experiments, using phase-contrast microscopy, untreated and 100 ng/ml PRL-treated cells appeared as a monolayer of flattened, fibroblast-like cells. Upon exposure to 0.4 IU/ml human chorionic gonadotrophin (hCG), aggregates of rounded, epithelioid-shaped cells were formed. The addition of PRL to hCG in the same doses minimized the changes induced by hCG. Similarly, electron microscopy of untreated and PRL-treated cultures revealed flat cells devoid of microvilli, with evenly dispersed microfilaments. The addition of hCG caused rounding of the cells and was accompanied by the appearance of microvilli and by pronounced steroid-producing organelles. Bundles of microfilaments were noted at the cell periphery. PRL added to hCG caused a reduction of the hCG effects, and the cell morphology was intermediate to that seen in untreated and hCG-treated cultures. The finding that PRL can prevent or minimize morphological changes caused by hCG in rat cultured granulosa cells correlates with the biochemical changes induced by PRL, and supports the concept that PRL is a modulator of gonadotrophic action in the ovary.

Animals↗
PubMed1977

Reticulocyte motility and form: studies on maturation and classification.

A new two-stage living cell cytological classification is presented for reticulocytes in the rat and shown on an overall population basis to be the equivalent of the classical new methylene blue staining characterization. Class 1 reticulocytes (R1) are motile and multilobular. They comprise about 25% of normal bone marrow reticulocytes, but none of the reticulocytes in normal blood. Class 2 reticulocytes (R2) are asymmetrically "deep dished" in appearance and contain visible refractile granules, viewed in phase-contrast microscopy. In animals "stimulated" by bleeding, the percentage of motile marrow reticulocytes is found to be a linear function of hematocrit over the range of about 25%-70% total reticulocytes. In the blood, the associated maximum rise of class R1 is only to about 8%. These and related cellular properties are discussed with respect to the maturation and release of normal reticulocytes. Applicability of this work to studies on humans and to pathology is also indicated.

Animals↗
PubMed1988

[Exact description of non-glomerular and glomerular erythrocyte forms in pediatric hematuria].

We examined 70 urinary sediments of 35 children with non-glomerular hematuria (NGH) and 65 urinary sediments of 17 children with glomerular hematuria (GH) by phase-contrast microscopy at 1,000 X magnification. In each urinary sediment 200 erythrocytes were classified into 18 types of "non-glomerular erythrocytes" and 15 types of "glomerular erythrocytes". According to the percentage of greatly altered erythrocytes the urinary finding was termed isomorphic, mixed or dysmorphic. In 91% of the urinary sediments of patients with NGH the erythrocyte pattern was isomorphic, and in 91% of the urinary sediments of children with GH it was dysmorphic. 9 types of non-glomerular erythrocytes and 10 types of glomerular erythrocytes constituted 94.5% of all 26,809 erythrocytes examined. Torocytes (doughnut-like cells) can be considered characteristic for GH. This study demonstrates a high specificity of this method in discriminating NGH from GH. The exact morphological description of urinary erythrocytes allows the method to be reproducible. For future use examiners can concentrate on the 19 commonest erythrocyte types.

Adolescent↗
PubMed1986

Phase contrast and electron microscopical observations of adult mouse dorsal root ganglion cells maintained in primary culture.

Cultures of neurons and non-neuronal cells were prepared from adult mouse dorsal root ganglia and maintained for periods of up to six weeks upon uncoated petri dish substrates. Modifications were made to both existing isolation procedures and culture medium to ensure high cell survival. Cell structure was observed using phase contrast microscopy for living cells and standard light microscopy for Palmgren silver stained preparations. Scanning and transmission electron microscopy revealed the fine structure of the cells and showed the close relationship of satellite cells with the surviving dark neurons as culture establishment progressed. Satellite cells were associated with both the cell bodies and the regenerated neuritic processes. The use of the cultures for future cytotoxicity testing is assessed.

Animals↗
PubMed1977

Role of vitamin E in glutathione-induced oxidant stress: methemoglobin, lipid peroxidation, and hemolysis.

Red blood cells (RBC) from normal and vitamin E-deficient rats were incubated in a hypertonic solution of reduced glutathione adjusted to pH 8. Methemoglobin formation occurred in intact RBC from both normal and vitamin E-deficient rats. Hemolysis was significantly greater in RBC from vitamin E-deficient rats. Experiments with catalase, superoxide dismutase, and methional showed that H(2)O(2) was the primary extracellular source of oxidant stress. Extracellular superoxide and hydroxyl radical were not involved in oxidant stress. Experiments with dimethyl sulfoxide showed that intracellular hydroxyl radical, generated from H(2)O(2), was the hemolytic agent. Neither methemoglobin formation nor lipid peroxidation involved hydroxyl radical. Indeed, lipid peroxidation and hemolysis in RBC from vitamin E-deficient rats were concurrent rather than consecutive events. Phase contrast microscopy showed that rigid, crenated RBC with a precipitate around the interior periphery formed during glutathione-induced oxidant stress. The precipitate dissolved slowly as the crenated RBC were converted to smooth ghosts. It appeared that protein precipitates involving mixed disulfide bonds were reduced and solubilized when extracellular glutathione penetrated the ruptured cell. Comparisons between normal RBC and vitamin E-deficient RBC suggest that vitamin E has little effect on the inward diffusion of extra-cellular H(2)O(2). Vitamin E apparently interacts with different oxidant species derived from intracellular H(2)O(2) in preventing lipid peroxidation and the sulfhydryl group oxidation leading to hemolysis.

Animals↗
PubMed1977

The trachea and cuff-induced tracheal injury. An experimental study on causative factors and prevention.

The effect of a large tracheal tube cuff on the rabbit tracheal mucosa was investigated by phase contrast microscopy and scanning (SEM) and transmission (TEM) electron microscopy. The tube was left in the trachea for 15 min. The cuff was either uninflated or inflated to a cuff-to-tracheal wall pressure (C-T pressure) of up to 100 mmHg. The uninflated cuff caused superficial damage to the epithelial lamina over regions where a cartilage was situated. When the cuff was inflated, it resulted in an increase of the mucosal damage, the extent of which was directly related to the pressure in the cuff. This took the form of both widening of the injured areas and penetration of the damage to deeper regions. At a C-T pressure of 100 mmHg the damage involved almost the entire mucosa and only small unaffected mucosal regions remained. At this stage it appeared as if the basement membrane had also begun to disintegrate. It is well known that a small cuff easily causes deep ulceration in the mucosa overlying the cartilages. From this investigation it was concluded that a large cuff causes the same type of ulceration if 1) the cuff wall is not sufficiently thin and pliable, and 2) if the cuff is overinflated enough to dilate the trachea to a diameter exceeding the cuff-diameter. At that moment there will be circumferential tension in the cuff and the sealing physics of the large cuff will become the sealing physics of a small (high pressure) cuff. A large cuff, properly handled, is more benign to the trachea than a small cuff. In order to avoid overinflation of the large cuff, the intracuff pressure (= C-T pressure) should always be measured by means of a four-way stopcock and an aneroid manometer. In the case of extended periods of mechanical ventilation with a high airway pressure, the resulting tracheal diameter at the cuff site should be checked radiographically.

Animals↗
PubMed1978

[Prediction of spontaneous abortion by vaginal cytologic smears (author's transl)i1].

Vaginal smears were obtained from 175 women during the first four months of pregnancy weekly and the Karyopycnotic Index and the Eosinophilic Index encountered by phase contrast microscopy. The normal values were listed our by percentils. The development of KPI and Eo I during early pregnancy were compaired in three groups of patients: 1, 120 women with normal early pregnancy, 2.20 women with threatened abortion but good following up of later pregnancy, and 3. 35 women with spontaneous abortion. Even 4 weeks before abortion vaginal smears changed to pathological values in about 40% of all patients with spontaneous abortion. Women with threatened abortion but good outcome of pregnancy used to have normal KPI and Eo I.

Abortion, Threatened↗
PubMed1979

[Morphology and deformability of erythrocytes in muscular dystrophy].

In recent years, the presence of red cell morphological abnormalities in patients with Muscular Dystrophy has made the object of numerous, often contradictory reports. A possible source of such confusion may lie in the fact that human erythrocytes are extremely sensitive to morphologic transformations resulting from various manipulations or environmental conditions in vitro. We have examined the morphology and deformability of erythrocytes from 7 patients with Duchenne and 9 patients with Steinert (myotonic) Muscular Dystrophy. To avoid preparation artifacts, fresh, unwashed red cells suspended in their own plasma were examined under phase contrast microscopy for the presence of either echinocytes and stomatocytes. Deformability was measured by filtration of dilute cell suspensions at constant flow rate through nucleopore membranes (nominal pore diameter = 3 micrometer). No significant difference was found between the patients' cells and those of 22 healthy volunteer controls. We conclude that previously reported abnormalities may have been the result of preparation artifacts. It appears possible, however, that erythrocytes from Muscular Dystrophy patients may be more sensitive than normal ones to certain stimuli originating from red cell manipulations in vitro.

Erythrocytes↗