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At least 433 records · Page 24Linked to original sources
PubMed1998

Cytohormonal evaluation of vaginal smears by phase contrast microscopy with special reference to progesterone deficiency pattern during early pregnancy as predictor of abortion.

Cytohormonal profile of unstained vaginal smears were studied under phase contrast microscope to define various cell morphologies in detail and build up of smear pattern serially in various stages of menstrual cycle and first trimester of pregnancy. The findings were correlated clinically and found comparable to Papanicolaou stained smears. The maturation index was calculated more objectively by phase contract microscopy because of the refractile appearance of the pyknotic nuclei of superficial cells. The prognostication of abortion was done by combining abnormal maturation index and the presence of syncytiotrophoblasts in vaginal smears. Under phase contrast microscope, the sensitivity of abnormal smear was 87.5%, the specificity was 95%, the positive predictive value was 96.55% and the overall accuracy was 90% as compared to positive Papanicolaou smear whose sensitivity though 93%, had low specificity of 50% only. Phase contrast study appears to offer certain distinct advantage over the conventional light microscopy for quick, comprehensive and quantitative assessment of the study material. It allows the physician to detect changes in the material obtained from the patients without detour of laboratory fixation and staining. It is technically easy as errors in interpretation due to unsatisfactory fixation, staining and artefacts are obviated. Thus phase contrast microscopy offers an alternative and easy method of cytohormonal evaluation of wet and unstained smears.

Abortion, Threatened↗
PubMed1979

The lamina splendens of articular cartilage is an artefact of phase contrast microscopy.

The so-called lamina splendens of articular cartilage is shown to be a characteristic of phase contrast microscopy; this technique provides no evidence for an anatomically distinct surface layer. Fresnel diffraction occurs at edges separating regions of different refractive indices. These diffraction effects, when viewed under phase contrast, lead to the appearance of a bright line along the edge.

Adolescent↗
PubMed1975

[Our experience with phase-contrast microscopy in clinical practice (author's transl)].

It is shown in a series of cases that phase-contrast microscopy is particularly suitable for intra-operative diagnosis in almost all gynecological operations. Also in smaller diagnostic measures (e. g. punch biopsy from the urinary bladder and rectum as well as curettage), phase-contrast assessment of the extracted tissue is possible with astonishing reliability.

Cytodiagnosis↗
PubMed1990

In vitro maturation of the exoerythrocytic stage of Plasmodium knowlesi observed under phase contrast microscopy.

Exoerythrocytic stages of Plasmodium knowlesi were obtained in primary culture of rhesus monkey hepatocytes. The development of a single parasite was followed with phase contrast microscopy until release of merozoites in slightly less than 5 days. This direct observation may offer opportunities to determine visually factors that may influence specific steps of schizont development.

Animals↗
PubMed2003

Predicting urine culture results by dipstick testing and phase contrast microscopy.

AIMS: Urine is the most frequently received clinical specimen for bacterial culture. To determine whether dipstick or microscopy results reliably predicted the presence or absence of a reportable urinary pathogen we performed dipstick testing and phase contrast microscopy on unspun urine from 500 specimens. We also investigated the relationship between the presence of squamous epithelial cells (SECs) and mixed growth on culture. METHODS: For each specimen, the presence of leukocyte esterase and urinary nitrite was recorded as well as the quantity of leukocytes (WBC), SECs, and erythrocytes. All cultures had the number and type of each organism recorded. Pyuria was defined as > or =10 WBC/mm(3). RESULTS: Specimens with <10 SEC/mm(3) had fewer isolates (0.9 isolate per culture) than specimens with > or =10 SEC/mm(3) (two isolates per culture); therefore, SEC contamination was defined as > or =10 SEC/mm(3). Of 500 specimens, 266 (53%) had no growth and 136 (27%) had mixed growth. A total of 288 (58%) specimens had negative dipstick results and completely normal microscopy. Of these, 11 (4%) had a pure growth of a urinary pathogen but the pathogen was present in only three (1%) at > or =10(5) CFU/mL. Of 413 urine specimens without SEC contamination, 323 (78%) had either no detectable growth or pure growth compared with only 41 of 87 (47%) with SEC contamination (P<0.001). Of the 413 urine specimens without SEC contamination, 90 (22%) had > or =2 organisms compared with 46 of 87 (53%) with contamination (P<0.01). Pyuria was present in only 21 of 266 (8%) urine specimens without growth but was present in 60 of 95 (64%) specimens containing a reportable pathogen (P<0.01). CONCLUSIONS: SEC contamination does not reliably predict cultures with mixed growth, urine specimens with negative dipstick results and microscopy rarely contain a reportable urinary pathogen, and screening algorithms are warranted and justified.

Adolescent↗
PubMed2002

High-resolution hard X-ray phase-contrast microscopy with a large-diameter and high-numerical-aperture zone plate.

An imaging transmission hard X-ray microscope has been constructed at beamline BL24XU of SPring-8. It makes use of a phase zone plate made of tantalum with a diameter of 1 mm and an outer-most zone width of 50 nm, aiming at a wide field of view and a high spatial resolution. The performance test was carried out at a photon energy of 10 keV. A field of view as wide as approximately 200 microm in diameter was achieved. The spatial resolution was measured to be 220 nm by analyzing a knife-edge image. Further, a line-and-space pattern as fine as 100 nm could be imaged. By placing a phase plate made of gold in the back focal plane of the zone plate, phase-contrast microscopy using Zernike's method was also carried out. The feasibility of phase-contrast microscopy for observing transparent samples was successfully demonstrated by imaging small polystyrene particles.

Journal Article↗
PubMed1989

Localisation of haematuria by red cell analysers and phase contrast microscopy.

The urinary erythrocyte morphology of 120 patients with haematuria of diagnosed cause (41 glomerular, 79 non-glomerular) was examined by red cell analyser (RCA) and by phase contrast microscopy (PCM). By RCA three distinct ranges of modal erythrocyte cell volume (ECV) were observed. The modal ECVs in glomerular haematuria (35-50 fl) were significantly lower than in non-glomerular haematuria (65-148 fl) and both were clearly distinct from 'debris patterns' (12-33 fl). In duplicate specimens very similar ECVs were observed before and after centrifugation and after storage for up to 15 h. There was no correlation between the modal urinary ECV and the urinary specific gravity or the peripheral venous ECV. The source of the haematuria (glomerular or non-glomerular) was identified correctly by RCA (PCM) in 100% (60%), 68% (71%) and 22% (39%), respectively, of patients with macroscopic, 3+ microscopic and 1-2+ microscopic haematuria. In no patient was the haematuria localised incorrectly by RCA as compared with 10% incorrect localisation by PCM. RCA and PCM are complementary non-invase tests and both should be performed whenever possible in the investigation of haematuria.

Adolescent↗
PubMed1989

[Phase contrast microscopy in the detection of bacteriuria].

Despite the recognized superiority of traditional culture methods to investigate bacteriuria their routine use in population studies is costly. We proposed to use Phase contrast microscopy (PCM) which allows clear visualization of bacteria with no centrifugation or staining. Urine samples from 214 patients were studied by PCM and results compared to those obtained by quantitative culture. MCF had 95% sensitivity and 96% specificity. Therefore, PCM may be used to screen urine samples for further bacteriologic study with the highest chance of obtaining positive cultures.

Bacteriological Techniques↗