Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Krypton”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,153 records · Page 64Linked to original sources
PubMed1996

[Expression of basic fibroblast growth factor and its receptor in the process of wound healing of rat retina after laser photocoagulation].

We investigated the expression of mRNA of basic fibroblast growth factor (bFGF) and FGF receptor 1 in rat retina after laser photocoagulation using in situ hybridization method. Pigmented rats (Brown Norway strain) received weak photocoagulation by krypton laser (500 microns, 0.05 sec, 60 mW) in the posterior retina. On 1, 3, 5, 7, 14 days after laser photocoagulation, the rats were fixed by perfusion with phosphate-buffered 4% paraformaldehyde and the eyes were enucleated. The eyes were further fixed by immersion in the same fixative, then quickly frozen in liquid nitrogen and finally sectioned with a cryostat. In situ hybridization was performed on frozen sections with digoxigenin (DIG) labeled riboprobes synthesized from rat bFGF cDNA and FGF receptor 1 cDNA. In normal chorioretinal tissue, the signals of bFGF and FGF receptor 1 mRNA were seen in the ganglion cell layer and inner nuclear layer. On day 3 after photocoagulation, we observed expression of bFGF and FGF receptor 1 mRNA in the proliferating retinal pigment epithelial (RPE) cells and endothelial cells of choriocapillaris at the photocoagulated lesion. We also observed expression of bFGF mRNA in some macrophage-like cells. On day 14 after photocoagulation, these expressions had disappeared. Our results suggest that bFGF may be involved in the process of retinal wound healing after laser photocoagulation.

Animals↗
PubMed1996

[Natural process of wound healing of photocoagulated retinal pigment epithelium in culture--observation of DNA synthesis by BrDu incorporation].

We examined the proliferation of retinal pigment epithelial (RPE) cells after krypton laser photocoagulation in culture. A pigmented monolayer of chick embryonic RPE cells was cultured on a collagen membrane placed on collagen gel. RPE cells were labeled with bromodeoxyuridine (BrDu) every 12 hours until 7 1/2 days after the photocoagulation and stained immunocytochemically with anti BrDu antibody. Immediately after the photocoagulation, RPE cells became detached at the burned lesion and the collagen membrane beneath the RPE layer was exposed. Some cells adjacent to the burned lesion showed DNA synthesis and subsequent mitosis between 12 to 24 hours after the photocoagulation. Cells with labeled nuclei migrated into the denuded burned area after 24 hours and covered the whole burned area within three days after the photocoagulation. DNA synthesis continued in these on the burned lesion after complete coverage of the lesion but stopped temporarily 3 1/2 to 4 1/2 days after the photocoagulation. Thereafter DNA synthesis increased again and continued until the end of the experiment. Such use of the cultured RPE cells might be useful in studying cellular reaction after photocoagulation.

Animals↗
PubMed1996

FGF receptor 1 expression in experimental choroidal neovascularization.

Fibroblast growth factor (FGF) is an important factor in neovascularization. To clarify the role of FGF, we demonstrated the expression of FGF receptor 1 mRNA in experimentally induced choroidal neovascularization using in situ hybridization. Krypton laser photocoagulation was applied to the posterior retina of colored rats to induce choroidal neovascularization; the eyes were removed at various intervals after photocoagulation. Chorioretinal sections were made, and FGF receptor 1 cDNA fragments were used to make antisense and sense probes for in situ hybridization. In normal chorioretinal tissue, stain indicating FGF receptor 1 mRNA was observed in the ganglion cells and the inner nuclear layer. After photocoagulation, FGF receptor 1 mRNA appeared in the retinal pigment epithelial cells, in melanocytes of the choroid and in the choroidal blood vessel wall of the photocoagulation lesions. This suggests that FGF is involved in the process of neovascularization. Previous studies have reported that the capillary endothelial cells and retinal pigment epithelial cells produce basic FGF in vitro; FGF may affect the cells in an autocrine or paracrine manner.

Animals↗
PubMed1996

Risk factors influencing the treatment outcome in diabetic macular oedema.

A multivariate analysis was done on 96 eyes to evaluate the effect of various risk factors on the final visual outcome after laser photocoagulation for clinically significant macular oedema (CSME) in diabetic retinopathy. Advanced age of the patient, large size of CSME and poor baseline visual acuity were found to be significantly associated with poorer outcome (p < 0.05). The association of nephropathy and hypertension with poorer visual outcome was of boderline significance (p = 0.054 and 0.07, respectively). Wavelength of the laser (argon or krypton) used for treatment did not significantly influence the outcome.

Diabetic Retinopathy↗
PubMed1998

Possible mechanisms of vascular relaxation induced by pulsed-UV laser.

This study was designed to examine the mechanism of vasorelaxation induced by pulsed-UV laser. Luminal diameters of rat femoral arteries were measured prior to and following krypton-fluoride excimer laser irradiation of 248 nm in wavelength. The diameter was enlarged to 1.3 times the preirradiated size at 1 or 10 Hz irradiation when the fluence was over 2.0 mJ/pulse/mm2, while the diameter reached 1.8 times at 100 Hz with a fluence of 0.8 mJ/pulse/mm2. Vasorelaxation by the 100 Hz irradiation was inhibited when the artery was pretreated with methylene blue but was enhanced with superoxide dismutase. Pathological analysis revealed an ablation crater and vacuole formation in the vessel at 1 or 10 Hz irradiation, but these changes were not remarkable in the 100 Hz-exposed sample. These findings suggest that vasorelaxation induced by the pulsed UV irradiation at 1 or 10 Hz results from structural alteration of vascular smooth muscle by the ablation crater or vacuolization. On the other hand, a possible mechanism of vasorelaxation at the 100 Hz irradiation is partially related to nitric oxide.

Animals↗
PubMed1978

Effect of rapid decompression and associated hypoxic phenomena in euthanasia of animals: a review.

Documentation in the literature indicates that death is as painless following the induction of hypoxia by rapid decompression as by other methods that lead to hypoxia, such as exposure to high altitude, carbon monoxide, and inert gases (nitrogen, xenon, and krypton). Many of the signs and symptoms of hypoxia are the same as those for alcoholic intoxication and inert gas narcosis. Moreover, there is good evidence that analogous relationships or mechanisms may exist for hypoxia, inert gas narcosis, and anesthesia.

Alcoholic Intoxication↗
PubMed2006

Apparent 85Kr ages of groundwater within the Royal watershed, Maine, USA.

Specific 85Kr activity is mapped from 264 domestic and municipal wells sampled during 2002-2004 in the Royal watershed (361 km2), Maine. Gas samples are collected at 20 m, 40 m, and > 50 m interval depths within the unconfined aquifers. Gas extraction for 85Kr from wells is obtained directly via a wellhead methodology avoiding conventional collection of large sample volumes. Atmospheric 85Kr input to the recharge environment is estimated at 1.27 Bq m(-3) by time-series analyses of weighted monthly precipitation (2001-2004). Numerical simulation of Kr gas transport through the variable unsaturated zones to the water table suggests up to 12-year time lags locally, thus biasing the 85Kr groundwater ages. Apparent 85Kr ages suggest that approximately 70% of groundwater near 20 m depth was recharged less than 30 years BP (2004). Mass-age transport modeling suggests that post mid-1950s recharge penetrates to part of the basin's floor and that older groundwater seeps from the underlying fractured bedrock may occur.

Computer Simulation↗