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Results for “Microscopy, Ultraviolet”

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PubMed1975

On the configuration of incremental lines in human dentine as revealed by tetracycline labelling.

The pattern of tetracycline labelling in dentine was investigated in ground sections of human teeth under visible and ultraviolet light. The tetracycline lines presented different appearances near the enamel-junction region, near the dentine-cementum junction, in the mantle dentine, and in the circumpulpal dentine, depending on whether the mineralization front was linear, globular or linear-globular.

Cementogenesis↗

PubMed1985

Foveomacular vitelliform dystrophy, adult type. A clinicopathologic study including electron microscopic observations.

Foveomacular vitelliform dystrophy, adult type (FVDAT), is a dystrophy of the retinal pigment epithelium (RPE) characterized in part by autosomal dominant inheritance, midlife onset, mild visual loss, and various patterns of foveal yellow deposits located at the level of the pigment epithelium. Detailed pathologic studies of two postmortem eyes from a 61-year-old woman with documented FVDAT disclosed striking abnormalities involving mainly the foveal RPE and overlying photoreceptors. By light microscopy, marked focal atrophy of the pigment epithelial cells in the foveolar area was bordered by hypertrophic RPE. Interposed between the atrophic RPE and Bruch's membrane were scattered eosinophilic, fusiform collagenous plaques. The sensory retina overlying the deranged RPE displayed marked atrophy of the outer nuclear layer with loss of photoreceptor inner and outer segments. Pigment-laden macrophages containing periodic acid-Schiff-positive material had migrated into the atrophic, outer sensory retina. Ultraviolet fluorescent microscopy demonstrated massive accumulation of lipofuscin pigment within the macular RPE as well as within macrophages in the atrophic outer retina. By scanning electron microscopy, a confluent area of flattened, atrophic retinal pigment epithelial cells was rimmed by taller, hypertrophic RPE cells. By transmission electron microscopy, the pigment epithelial cells contained myriad lipofuscin granules. Bruch's membrane and the intercapillary pillars were slightly thickened and the choriocapillaris was patent. The possible interrelationships between FVDAT and the other pattern dystrophies of the RPE are discussed.

Female↗

PubMed2002

Effect of hyperosmolar mannitol on convection-enhanced delivery into the rat brain stem.

INTRODUCTION: Convection-enhanced delivery (CED) can safely achieve high local infusate concentrations within the rat brain stem with predictable distribution volumes. The authors investigated the effects of co-infusion or systemic administration of hyperosmolar mannitol on distribution parameters for infusions into the rat brain stem. METHODS: Fifteen rats underwent stereotactic cannula placement into the pontine nucleus oralis (PnO) followed by infusions at a constant rate to a total volume of 1 microl. Five rats underwent infusion of fluorescein isothiocyanate (FITC)-dextran diluted in 20% mannitol. Five rats received an intraperitoneal injection of 20% mannitol 10 min prior to infusion of FITC-dextran diluted in isotonic saline. As a control group, 5 rats underwent infusion of FITC-dextran diluted in isotonic saline without mannitol administration. Serial brain sections were imaged using confocal microscopy with ultraviolet illumination, and distribution volume (Vd) was calculated by computer image analysis. Histologic analysis was performed on adjacent sections. RESULTS: Volumes of distribution were not significantly increased by co-infusion of mannitol directly into the brain stem or by systemic mannitol administration compared to infusion without mannitol. Similarly, mannitol administration by either means failed to significantly alter maximal cross-sectional area or cranio-caudal extent of fluorescence. No animal demonstrated a postoperative neurological deficit or histologic evidence of tissue disruption. CONCLUSIONS: Neither systemic administration nor co-infusion of hyperosmolar mannitol significantly affects distribution parameters for CED infusions into the rat brain stem.

Animals↗

PubMed2003

Ultraviolet-light-absorbing tunic cells in didemnid ascidians hosting a symbiotic photo-oxygenic prokaryote, Prochloron.

Coral reef invertebrates that host phototrophic symbionts are thought to protect themselves and their symbionts with mycosporine-like amino acids (MAAs)-UV-absorbing substances that act as sunscreens (Dunlap, W. C., and J. M. Shick, 1998. J. Phycol. 34: 418-430). However, the histological distribution of MAAs in the host tissues has not yet been visualized. We have localized the UV-absorbing substances in the tissues of two colonial didemnid ascidians-Lissoclinum patella and Diplosoma sp.-that contain the symbiotic photo-oxygenic prokaryote Prochloron sp. Cross-sections of unfixed tissue from these ascidians were examined by UV-light microscopy at 320 or 330 nm, wavelengths at which UV light is absorbed by MAAs. Within the tunic, the gelatinous integument of the colony, UV light was exclusively absorbed by a particular type of cell, the tunic bladder cell. Tunic bladder cells with strong UV absorption were denser in the upper tunic, which lies over a colony's zooids, than in the basal tunic underlying the zooid. In the upper tunic, those cells with strong UV absorption were most dense near the surface. The tunic bladder cell is highly vacuolated, and the vacuole contains strong acid, which destabilizes MAAs. Furthermore, the UV-absorbing portion of tunic bladder cells seemed to be cup-shaped, indicating that the MAAs are not localized in the vacuole, but in the cytoplasm. These results strongly suggest that didemnid ascidians accumulate MAAs in tunic bladder cells as a protection against UV radiation.

Amino Acids↗

PubMed1989

Effect of intravenous administration of corticosteroids on dentin formation in the adult rat molar.

This study describes the effects of intravenously given corticosteroids on dentin formation in adult rat molars. Six rats twice a day received corticosteroids 20 mg/kg for 8 days, 10 mg/kg for 13 days, and 5 mg/kg for 19 days. Six rats given a heterotopic heart transplant received 10 mg/kg of corticosteroids twice a day for 40-64 days. Six rats were used as controls. Tetracycline was given at the start of the experiment and after 3 wk of treatment. After 40-46 days the rats were killed. Light microscopic examination of the molars showed no differences in the dentin formation or in the predentin zone between the experimental and control rats. In the ultraviolet light microscope two lines of tetracycline were visible along the root canal walls in both experimental groups. There was an obvious distance between the two lines, which indicated formation of new dentin. In the control group no formation of dentin was visible.

Animals↗

PubMed1994

Naturally occurring tetracycline-like fluorescence in sections of femur from jackals in Zimbabwe.

In assessing the potential of the tetracycline compounds as biomarkers in oral rabies vaccination campaigns in jackals in Zimbabwe, the natural prevalence of fluorescent compounds in bone tissue from jackals was investigated. Femur samples were taken from unbaited jackals received for routine rabies diagnosis, and thin undecalcified sections were cut and viewed under an ultraviolet microscope. Of 131 femur samples examined, 49 (37 per cent) had fluorescent markings indistinguishable from those of tetracycline. The result implies that the tetracycline compounds, which are commonly used in rabies baiting campaigns in Europe and North America, cannot be used as biomarkers in jackals in Zimbabwe.

Animals↗

PubMed1979

Acquired lipidosis of marrow macrophages: birefringent blue crystals and Gaucher-like cells, sea-blue histiocytes, and grey-green crystals.

Three varieties of compound lipid inclusions occurring as a secondary phenomenon in marrow macrophages are detectable and distinguishable by Romanowsky staining, ultraviolet fluorescence, and polarised light. Birefringent blue crystals and Gaucher-like cells form one variety, sea-blue granules another, and grey-green crystals a third. All occur chiefly in myeloid leukaemias, either acute or chronic.

Birefringence↗

PubMed2004

Photography of the living human cornea in ultraviolet light.

The living human cornea was photographed in ultraviolet light of bandpass 315-326 nm produced by a xenon arc light source and multilayer interference filters. The image was captured on black and white film using a quartz fluorite lens. The photographs revealed structural details not seen in visible wavelengths.

Adult↗

PubMedDate not supplied

Cytologic detection of Cryptococcus neoformans in cerebrospinal fluid. Rapid screening methods.

Yeasts of Cryptococcus neoformans in cerebrospinal fluid (CSF) were studied using polarized light and fluorescence microscopy. Ultraviolet-induced fluorescence of wet-fixed, Papanicolaou-stained smears and polarization of air-dried, Diff-Quik or Leishman-stained preparations are complementary methods that allow for rapid screening for and immediate identification of Cryptococcus in cytologic preparations of CSF.

Birefringence↗

PubMed1974

Aflatoxin-producing strains of Aspergillus flavus detected by fluorescence of agar medium under ultraviolet light.

The fluorescence method of detecting aflatoxin-producing strains of Aspergillus flavus and related species utilizes the ultraviolet-induced fluorescence of aflatoxin produced in a modified Czapek's solution agar containing corn steep liquor, HgCl(2), and (NH(4))H(2)PO(4) instead of NaNO(3). The presence of aflatoxin is confirmed by thin-layer chromatography of CHCl(3) extracts of the fluorescing agar.

Aflatoxins↗

PubMed1977

[Intensity of ultraviolet fluorescence of the cells depending on their size].

Using the light microscope, a correlation between ultra-violet fluorescence intensity of the cell and the cell area was established. This correlation does not depend on the large aperture of the microscope. A possible cause of this correlation is supposed to be either the proportionality between the mass of cytoplasmic protein and the squared cell radius, or a high optical density of cell elements.

Animals↗

PubMed1990

[A method for the luminescence microscopy of the thrombocytes in the diagnosis of hemostatic disorders in patients with cerebral atherosclerosis].

The authors evaluated the diagnostic importance of morphological properties of thrombocytes in patients with cerebral atherosclerosis. The proposed method consists in vital staining of thrombocytes in the blood plasma by means of acridine arrange, their fixation, application of a smear, microscopy in ultraviolet rays with determination of the ratio of thrombocytes of separate classes according to the intensity of luminescence of cellular alpha-granules and presence of aggregates. The method may be used for the prognosis of thrombotic complications in patients with atherosclerotic dyscirculatory encephalopathy and controlling the efficacy of therapy by antiaggregant agents.

Adult↗

PubMed2005

Conformational changes in single-strand DNA as a function of temperature by SANS.

Small-angle neutron scattering (SANS) measurements were performed on a solution of single-strand DNA, 5'-ATGCTGATGC-3', in sodium phosphate buffer solution at 10 degrees C temperature increments from 25 degrees C to 80 degrees C. Cylindrical, helical, and random coil shape models were fitted to the SANS measurements at each temperature. All the shapes exhibited an expansion in the diameter direction causing a slightly shortened pitch from 25 degrees C to 43 degrees C, an expansion in the pitch direction with a slight decrease in the diameter from 43 degrees C to 53 degrees C, and finally a dramatic increase in the pitch and diameter from 53 degrees C to 80 degrees C. Differential scanning calorimeter scans of the sequence in solution exhibited a reversible two-state transition profile with a transition temperature of 47.5 +/- 0.5 degrees C, the midpoint of the conformational changes observed in the SANS measurements, and a calorimetric transition enthalpy of 60 +/- 3 kJ mol(-1) that indicates a broad transition as is observed in the SANS measurements. A transition temperature of 47 +/- 1 degrees C was also obtained from ultraviolet optical density measurements of strand melting scans of the single-strand DNA. This transition corresponds to unstacking of the bases of the sequence and is responsible for the thermodynamic discrepancy between its binding stability to its complementary sequence determined directly at ambient temperatures and determined from extrapolated values of the melting of the duplex at high temperature.

Algorithms↗

PubMed1988

Aberrant development of Trichophyton mentagrophytes hyphae cultured in the presence of Congo red.

When Trichophyton mentagrophytes colonies were placed on a medium containing 150 micrograms/ml of Congo red, a dye which prevents chitin fibrillogenesis, their growth rate was reduced. The newly formed mycelium, examined under an ultraviolet microscope, consisted of thick, curled and branched hyphae endowed with swollen tips and subapical bulges. Short-time exposure revealed that the major sites of dye accumulation were the extension zones. Normally structured hyphae arose from aberrant mycelia when they were transferred onto a dye-free medium. The phenomena observed suggest that Congo red alters the wall properties of the extension zone, by inhibiting the gradual conversion of chitin chains, synthesized at the extreme tip, into microfibrils of increasing size and density.

Congo Red↗

PubMed2003

Preliminary characterization of a light-rare-earth-element-binding peptide of a natural perennial fern Dicranopteris dichotoma.

A light-rare-earth-element (LREE)-binding peptide was isolated from LREE hyperaccumulator Dicranopteris dichotomaleaves and characterized in terms of molecular weight and ultraviolet absorption spectrum. The molecular weight of the LREE-binding peptide was determined to be 2208 Da by matrix-assisted laser-desorption ionization-time of flight mass spectrometry (MALDI-TOFMS). The characteristic ultraviolet absorption spectrum of the peptide was observed at 220-300 nm, suggesting that the peptide chain contained aromatic amino acids. Compared to the unique features of the phytochelatins with a low absorption at 280 nm, the LREE-binding peptide is unlikely to be a typical phytochelatin. The present study suggests that the LREE-binding peptide is probably a natural peptide in D. dichotoma, and it may play an important role in hyperaccumulation of LREEs.

Cerium↗

PubMed2000

The behaviour of the plasma membrane during plasmolysis: a study by UV microscopy.

A high resolution ultraviolet (UV) bright-field microscope was used to analyse the formation of Hechtian strands and the Hechtian reticulation that remain attached to the cell wall after plasmolysis and deplasmolysis of onion inner epidermal cells. In real time video images, UV microscopy allowed a detailed investigation of the dynamic behaviour of the plasma membrane during the processes of osmotic water loss and uptake. Furthermore, the role of cytoskeletal elements as possible linkers of the plasma membrane to the cell wall was probed by application of cytoskeletal drugs during plasmolysis. Microtubules were depolymerized in oryzalin, and latrunculin B was used to destabilize actin microfilaments. The results showed no visible changes in the formation of the Hechtian reticulation or strands. Plasmolysis forms appeared to be normal, indicating stong membrane-to-wall attachments independent of cytoskeletal elements. During re-expansion of the protoplast in deplasmolysis, the plasma membrane incorporated Hechtian strands and subprotoplasts, fused with the Hechtian reticulation and finally realigned at the cell wall.

Bridged Bicyclo Compounds, Heterocyclic↗

PubMed1997

Effects of oral administration of purified micronized flavonoid fraction on increased microvascular permeability induced by various agents and on ischemia/reperfusion in the hamster cheek pouch.

The effects of a clinically used purified micronized flavonoid fraction (S 5682) containing 90% diosmin and 10% hesperidin on increased microvascular permeability induced by histamine, bradykinin, and leukotriene B4 (LTB4) were investigated by intravital microscopy in the hamster cheek pouch preparation. The authors also investigated the effects of S 5682 on macromolecular permeability increase and leukocyte adhesion during ischemia-reperfusion by using the same preparation. S 5682, suspended in 10% lactose solution, or vehicle (10% lactose) was administered orally to male hamsters for ten days at 20 mg/kg/day (10 mg/kg twice a day). Fluorescein isothiocyanate (FITC)-labeled dextran (mol wt 150,000) was given intravenously, thirty minutes after completion of the cheek pouch preparation. The leukocytes were stained by continuous IV infusion of acridine orange (0.5 mg/kg/minute). Histamine (2 microM), bradykinin (1 microM), and LTB4 (0.01 microM), applied topically for five minutes, increased the number of fluorescent vascular leakage sites in postcapillary venules. A temporary ischemia with total circulatory arrest of the cheek pouch was obtained by clamping the neck of the everted pouch. The maximum number of leaky sites (per cm2 in the prepared area) that occurred either at five minutes after the beginning of each topical application or ten minutes after the onset of reperfusion was quantified in ultraviolet light microscopy. The results from 60 animals divided into 10 groups of 6 animals each are presented as means +/- SEM. In comparison with vehicle, S 5682 significantly inhibited the macromolecular permeability increasing effect of histamine (343.5 +/- 22.3 versus 207.5 +/- 32.0 leaks/cm2; P < 0.01), bradykinin (345.2 +/- 19.0 versus 206.2 +/- 21.6 leaks/cm2; P < 0.01), and LTB4 (353.3 +/- 27.5 versus 242.7 +/- 33.6 leaks/cm2; P < 0.05). At reperfusion, after thirty minutes of ischemia, S 5682 significantly decreased the observed macromolecular permeability (103.6 +/- 15.4 versus 42.6 +/- 9.3 leaks/cm2; P < 0.01). Flavonoid-treated animals also displayed a statistically significant lower number of adhering leukocytes to the venular endothelium (83.5 +/- 9.5 versus 48.4 +/- 12.3 per 6 mm2; P < 0.05). These results demonstrate that oral administration of S 5682 for ten days at 20 mg/kg body weight/day had a protective effect against leakage of macromolecules after application of permeability-increasing substances and during ischemia-reperfusion in the cheek pouch microvasculature. Since firm leukocyte attachment to the endothelial wall and subsequent emigration of leukocytes into the interstitium is a mechanism for tissue damage during inflammation, attenuation of this phenomenon during conditions of ischemia-reperfusion can in part explain previous observations that this purified micronized flavonoid fraction decreases edema formation. The present data illustrating the inhibitory effect of a clinically relevant dose of S 5682 on the inflammatory processes induced in this in vivo model of microcirculation may serve as a rational basis to explain its clinical efficacy.

Administration, Oral↗

PubMed1990

Simple non-invasive early detection and localization of specific cancer tissues of internal organs and differentiation of cancer tissue from surrounding areas infected by cancer related viruses, as well as evaluation of their micro-circulatory condition & drug uptake using the BI-Digital O-Ring Test.

In 1984, the author first developed a simple, quick, non-invasive, economical method of detecting cancer in specific internal organs, using the Bi-Digital O-Ring Test (BDORT), with a microscope slide of specific cancer of a specific internal organ as a reference control substance. The detection rate for cancer screening was much greater than with any standard diagnostic tests. When imaging was performed using the BDORT, the area of positive response to the cancer positive slide was often much greater than the actual size of the cancer itself. This was due to the fact that most of the cancer tissue of the lungs or digestive system contained viruses such as HTLV-3 (often found in adenocarcinoma of the lung, stomach, head of pancreas, and colon) or HTLV-1 (often found in small-cell carcinoma of the lung and certain types of leukemia). The extent of the virus positive area was often far greater than that of the cancer tissue itself and was distributed in a much greater area surrounding the cancer. For this reason, the virus alone showed a response which could be mistaken for cancer tissue. The author succeeded in differentiating the exact location of cancer tissue itself from surrounding cancer related virus (with or without other microbes) positive area by using a pair of identical microscope slides with the same cancer tissue. One of the slides was exposed to ultra-violet rays (peak wavelength of 253.7 nm mercury vapor atomic resonance spectral line) for 40 seconds-4 minutes. After this exposure, the BDORT response to the virus (with or without other microbes) associated with the cancer tissue was completely eliminated, while the response to the cancer tissue was maintained. Using an ultraviolet exposed cancer slide, the imaging of the part of the body which responded to this virus-free cancer slide indicated the actual location of the cancer tissue, which was often confirmed by standard X-ray or other imaging methods when the thickness of the tumor was relatively large. These cancers detectable by standard laboratory tests had strikingly weakening response to the BDORT (-3.5 and -4), with ultra-violet exposed cancer slide as well as for antibody of Oncogen C-fos. The smallest size of cancer tissue detected by this method was less than 1mm in diameter in the very early stage of the cancer, which usually cannot be detected by current laboratory tests.(ABSTRACT TRUNCATED AT 400 WORDS)

Aged↗