Search results for "helium"
showing 10 items of 1689 documents
Two Novel Deletions (Array CGH Findings) in Pigment Dispersion Syndrome
2007
Purpose: We report the first male with pigment dispersion syndrome and a balanced translocation t(10;15)(p11.1;q11.1). Methods: Cytogenetic analyses using Giemsa banding and FISH methods, and array CGH were performed. Results: Array CGH analyses did not show altered DNA sequences in the breakpoints of the translocation, but revealed two novel deletions in 2q22.1 and 18q22.1. Conclusion: We suppose that the coexistence of t(10;15) and pigment dispersion syndrome in our patient is a coincidence. The deletion in 2q22.1, where the gene LRP1B has been located, may play a major role in the dysembryogenesis of the eye and cause the disorder.
Aging changes of the ciliary epithelium border layers and their significance for intraocular pressure.
1971
Healon5 versus Viscoat during cataract surgery: intraocular pressure, laser flare and corneal changes
2000
Background: The use of a viscoelastic substance facilitates cataract surgery. Healon 5 is a new viscoelastic product with special rheological properties. We evaluated the postoperative effect of Viscoat and Healon5 on intraocular pressure (IOP), central corneal thickness (CCT), endothelial cell counts and laser flare. Methods: Forty-eight eyes of 48 patients undergoing routine phacoemulsification followed by foldable IOL implantation were enrolled. Either Healon5 or Viscoat was used according to a block- randomization scheme. The aspiration technique was standardized. IOP, CCT, endothelial cell counts and laser flare were compared pre- and postoperatively. Statistical analysis was performed…
Short-term Follow-up after Implantation of a Foldable Iris-Fixated Intraocular Lens in Phakic Eyes
2005
Objective To evaluate efficiency, predictability, stability, complications, and patient satisfaction after implantation of a foldable iris-fixated phakic intraocular lens (PIOL) for the correction of myopia. Design Prospective, nonrandomized, comparative (self-controlled) trial. Participants Forty-one eyes of 22 myopic patients aged 18 to 56 years (mean, 36 years) with average sphere of −8.2±2.01 diopters (D; range, −12.25 to −3.75 D) and average preoperative cylinder of −0.90±0.62 D (range, −2.50 to 0.00 D) were enrolled in this prospective study. Methods All eyes underwent implantation of a foldable iris-fixated PIOL with an optical zone of 6.0 mm. The follow-up was 6 months in all cases.…
Volumetry of Ventilated Airspaces by 3He MRI
2001
To develop a validated post-processing routine for volumetry of the ventilated airspaces by 3He MRI.3Helium MRI and pulmonary function tests were performed in seven healthy volunteers. After segmentation of ventilated airspaces, their volumes were calculated. Functional residual capacity (FRC) was used as a reference. For comparison of absolute volumes, correction factors were evaluated.Mean lung volume (+/- standard deviation) calculated from 3He MRI was 4,082 +/- 908 mL and mean FRC was 3,696 +/- 1166 mL, with a mean difference of 386 mL (r = 0.88). After correction for the relative pulmonary air content (factor 0.82), posture (0.72), and the individual tidal volume, 3He MRI volume was 3,…
Nuclear magnetic resonance imaging with hyperpolarised helium-3
1996
Abstract Summary Background Magnetic resonance imaging (MRI) relies on magnetisation of hydrogen nuclei (protons) of water molecules in tissue as source of the signal. This technique has been valuable for studying tissues that contain significant amounts of water, but biological settings with low proton content, notably the lungs, are difficult to image. We report use of spin-polarised helium-3 for lung MRI. Methods A volunteer inhaled hyperpolarised 3 He to fill the lungs, which were imaged with a conventional MRI detector assembly. The nuclear spin polarisation of helium, and other noble gases, can be greatly enhanced by laser optical pumping and is about 10 5 times larger than the polari…
Biaxial Microincision versus Coaxial Small-Incision Clear Cornea Cataract Surgery
2005
Objective To compare clinical outcomes of biaxial microincision (1.5 mm) and coaxial small-incision (2.75 mm) clear cornea cataract surgery. Design Randomized controlled clinical trial. Participants Seventy eyes of 70 patients were examined at a German university eye hospital. Intervention The 70 patients (70 eyes) were assigned randomly (1:1) to a biaxial or conventional coaxial incision group. Both groups underwent phacoemulsification using pulsed ultrasound energy with variable duty cycles, followed by microincision intraocular lens implantation. Main Outcome Measures Best-corrected visual acuity (BCVA), astigmatism, laser flare photometry value, effective phacoemulsification time (EPT),…
Effects of Some Guanidino Compounds on Human Cerebral Arteries
1999
Background and Purpose —Accumulation of endogenous guanidino-substituted analogues of l -arginine in chronic renal failure might contribute to some of the vascular and neurological disorders of this pathology. We tested the hypothesis that in human cerebral arteries, some guanidino compounds may increase vascular tone, through nitric oxide (NO) synthase inhibition, and impair endothelium-dependent relaxation. Methods —Rings of human middle cerebral artery were obtained during autopsy of 26 patients who had died 3 to 12 hours before. The rings were suspended in organ baths for isometric recording of tension. We then studied the responses to N G -monomethyl- l -arginine (L-NMMA), N G , N G -…
Enhancement of endothelial cell E-selectin expression by sera from patients with active Behçet's disease: moderate correlation with anti-endothelial …
1999
We studied the in vitro E-selection expression of endothelial cells treated with sera from patients with Behcet's disease (BD) and factors (anti-endothelial cell antibodies, anti-neutrophil cytoplasmic antibodies, cytokines, and myeloperoxidase (MPO) that may contribute to adhesion molecule expression. A total of 21 patients with BD and 27 healthy controls were studied. In vitro E-selectin endothelial cell expression was investigated by ELISA after HUVEC incubation with sera or purified IgG from patients with BD and controls. Increased E-selectin expression was observed when endothelial cells were incubated with sera from patients with active disease or from patients with circulating anti-e…
Relaxation and cyclic GMP levels in response to sildenafil in human pulmonary arteries from donors.
2005
We measured cyclic GMP formation and relaxation response to sildenafil given either alone or in combination with sodium nitroprusside (SNP) in pulmonary arteries obtained from 13 multi-organ donors. Sildenafil (10(-9)-10(-4) M) caused concentration-dependent relaxations and amplified the relaxation induced by SNP. Relaxation was unaffected by endothelium removal or by pre-treatment with the inhibitor of nitric oxide synthase L-NMMA (10(-4) M). SNP (10(-7) M) caused elevation of cyclic GMP levels that was potentiated by sildenafil (10(-6) M). Thus, the enhancement of SNP-induced relaxation by sildenafil is mainly due to an increase in cyclic GMP accumulation.