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At least 235 records · Page 13Linked to original sources
PubMed1972

Germination and outgrowth of single spores of Saccharomyces cerevisiae viewed by scanning electron and phase-contrast microscopy.

Single spores of Saccharomyces cerevisiae were examined during germination and outgrowth by scanning electron and phase-contrast microscopy. Also determined were changes in cell weight and light absorbance, trehalose utilization, and synthesis of protein and KOH-soluble carbohydrates. These studies reveal that development of the vegetative cell from a spore follows a definite sequence of events involving dramatic physical and chemical modifications. These changes are: initial rapid loss in cellular absorbance followed later by an abrupt gain in absorbance; reduction in cell weight and a subsequent progressive increase; modification of the spore surface with concomitant diminution in refractility; elongation of the cell and augmentation of surface irregularities; rapid decline in trehalose content of the cell accompanied by extensive formation of KOH-soluble carbohydrates; and bud formation.

Carbohydrates↗
PubMed1991

[Value of phase-contrast microscopy in differential diagnosis of erythrocyturia].

In 41 patients with erythrocyturia the usefulness was assessed of phase-contrast microscopy of erythrocytes in urinary sediment. In all 28 patients with non-glomerular erythrocyturia (less than 20% of changed sediment erythrocytes) non-glomerular, mainly urological, causes of erythrocyturia were found. In 13 cases of glomerulonephritis confirmed by biopsy erythrocyturia was in 6 cases of glomerular character (greater than 60% of changed sediment erythrocytes), in the remaining 7 cases it was of mixed character (greater than 20-60% of changed sediment erythrocytes). In cases of glomerulonephritis a correlation was found between the per cent of changed sediment erythrocytes in this microscopy and the severity of glomerulopathy and the coexistence and intensity of interstitial-tubular changes in renal biopsy. The accepted mode of differential diagnosis of erythrocyturia includes presently renal biopsy in case of glomerular erythrocyturia and undertaking of urological diagnostic procedures in case of non-glomerular erythrocyturia. In case of mixed erythrocyturia the diagnostic procedure is as yet as in non-glomerular erythrocyturia. This will be eventually changed when our experience will increase.

Adolescent↗
PubMed2004

Quantitative phase-amplitude microscopy. III. The effects of noise.

We explore the effect of noise on images obtained using quantitative phase-amplitude microscopy - a new microscopy technique based on the determination of phase from the intensity evolution of propagating radiation. We compare the predictions with experimental results and also propose an approach that allows good-quality quantitative phase retrieval to be obtained even for very noisy data.

Artifacts↗
PubMed1983

Effect of specimen support film in solid phase immunoelectron microscopy.

The type of grid support film used in solid phase immunoelectron microscopy (SPIEM) for poliovirus affected the efficiency of virus trapping. Parlodion/carbon films coated with homologous antiserum were found to be 9 times more efficient in trapping virus than similar grids prepared with Formvar/carbon, and 20 times better than SPIEM grids prepared with pure carbon films. Trapping efficiency could be further improved if support films were pretreated prior to exposure to viral antiserum. Maximum efficiency was obtained with Parlodion/carbon films pretreated with UV light. Almost as efficient were Parlodion/carbon and Formvar/carbon films pretreated with glow discharge ionization.

Antibodies, Viral↗
PubMed1950

Studies on the life cycle of spirochetes; the life cycle of the Nichols pathogenic Treponema pallidum in the rabbit testis as seen by phase contrast microscopy.

A series of observations with the phase contrast microscope on the occurrence of a complex life cycle in the pathogenic Treponema pallidum as it occurs in the syphilitic rabbit testis has been presented and it seems likely from these observations that there are two means of vegetative reproduction, consisting of (1) transverse division (the most important under usual conditions); and (2) the production of gemmae or buds which eventuate into unispirochetal cysts comparable to those described for saprophytic forms, within each of which single spirochetes develop and differentiate, and from which they subsequently emerge. In addition preliminary evidence is presented which suggests that a more complex process is involved in which multispirochetal cysts develop following aggregation of two or more organisms. Within each of these larger cysts numerous organisms develop and subsequently emerge as tangled ropes. Following emergence, they subsequently undergo transverse division and gemmae formation, and so reproduce vegetatively. Subsequent papers will elaborate upon these processes.

Animals↗
PubMed1976

Lymphocyte locomotion. II. The lymphocyte traffic over the post-capillary venules analysed by phase contrast microscopy of thin sections of rat lymph nodes.

Thin sections of lymph nodes from 14 rats were examined by phase contrast microscopy as regards direction of lymphoctes with amoeboid movement configuration (AMC) relative to the basement membrane of post-capillary high-endothelium venules (HE-cenules). Out of 118 lymphocytes with AMC, 82 appeared to be on theyr way into the venule from the lymph node parenchyma. This observation suggests that the lymphocyte traffic over the HE-venules is bi-directional, with the main migratory stream of lymphocytes from the lymph node parenchyma into the post-capillary venules.

Animals↗
PubMed1992

Comparative assessment of phase contrast microscopy and Coulter counter measurements in localising the site of haematuria.

Haematuria is a common diagnostic problem in clinical practice and is seen in a large number of renal, urological and systemic disorders. The routine use of dipstick methods has increased the frequency of detection of microscopic haematuria. It is desirable to develop a simple, non-invasive, easily reproducible, quantitative technique that would help to determine the site of bleeding and thereby direct the patient either to the nephrologist or to the urologist. This study compares the accuracy of phase contrast microscopy with Coulter counter measurement of red cell distribution volumes as a means of distinguishing glomerular haematuria from non-glomerular haematuria. Of 20 patients with biopsy-proven glomerulonephritis, 13 (65%) were correctly identified by phase contrast microscopy and 19 (95%) by the Coulter counter method. In 18 patients with pathological conditions affecting the lower urinary tract phase contrast microscopy was correct in 6 (33%) and Coulter counter measurement in 17 (94%). Coulter counter measurement is the simpler and more accurate method of screening for the source of haematuria, but is inaccurate when the red cell count in the urine is less than 0.02 x 10(12).

Adolescent↗
PubMed1975

Differential count of urinary leucocytes and renal epithelial cells by phase contrast microscopy.

A total of 291 urine sediments from 255 patients with various renal or urinary tract diseases have been studied by phase contrast microscopy. Based upon morphological criteria, leucocytes were distinguished from renal epithelial cells and the white blood cells were classified either as mononuclear or polynuclear in 179 patients. The percentage of the different cell types varied considerably between and within the different diseases. The median values for polynuclear granulocytes were higher than 90% in bacterial renal or urinary tract disease and in polycystic kidney disease. In interstitial nephritis, nephrosclerosis and in renal transplanted patients the percentage of polynuclear granulocytes was somewhat lower, 76-85%. In diabetes, amyloidosis, tubular nephrosis (necrosis) glomerulonephritis, lupus nephritis and endemic benign nephropathy there were 14-66% polynuclear granulocytes. 29-33% mononuclear leucocytes were found in lupus nephritis and endemic benign nephropathy. The greatest proportion of renal epithelial cells was found in endemic benign nephropathy, namely 49%. 36% renal epithelial cells were found in tubular nephrosis (necrosis) and in glomerulonephritis. The technique is rapid and inexpensive. It facilitates differential diagnostics of urinary tract disease with pyuria.

Amyloidosis↗