Methods First (methods + first)

Distribution by Scientific Domains


Selected Abstracts


Caspase-1/interleukin-1beta signaling in diabetic retinopathy

ACTA OPHTHALMOLOGICA, Issue 2008
S MOHR
Purpose The pro-inflammatory cytokine, interleukin-1, (IL-1,), is known to induce vascular dysfunction and cell death. Previously, we have shown that caspase-1 activity is increased in retinas of diabetic and galactosemic mice, and diabetic patients. Therefore, we investigated the role of IL-1, and caspase-1 (the enzyme that produces it) in diabetes-induced degeneration of retinal capillaries. Methods First, we determined the effect of agents known to inhibit caspase-1 (minocycline and tetracycline) on IL-1, production and retinal capillary degeneration in diabetic and galactose-fed mice. Diabetic and galactose-fed mice were injected intraperitoneally with minocycline or tetracycline (5mg/kg). Second, we examined the effect of genetic deletion of the IL-1, receptor on diabetes-induced caspase activities and retinal capillary degeneration using IL-1 receptor knock-out mice. Results At 2 months of diabetes, minocycline inhibited hyperglycemia-induced caspase-1 activity and IL-1, production in the retina. Long-term administration of minocycline prevented retinal capillary degeneration in diabetic (6 months) and galactose-fed (13 months) mice. Tetracycline inhibited hyperglycemia-induced caspase-1 activity in vitro, but not in vivo. Mice deficient in the IL-1, receptor were protected from diabetes-induced caspase activation and retinal pathology at 7 months of diabetes. Conclusion These results indicate that the caspase-1/IL-1, signaling pathway plays an important role in diabetes-induced retinal pathology and its inhibition might represent a new strategy to inhibit capillary degeneration in diabetic retinopathy. [source]


Purkinje based IOL centration

ACTA OPHTHALMOLOGICA, Issue 2008
MJ TASSIGNON
Purpose Surgeon-controlled centration of IOLs might be an issue when introducing IOL optics yielding additional properties aiming at correcting spherical aberrations, astigmatism and accommodation or pseudoaccommodation. Methods First and third Purkinje reflexes can be used during cataract surgery for the purpose of IOL alignment provided the IOL allows that freedom of action. The bag-in-the-lens (BIL) concept has been designed to add this dimension of freedom to the surgeon. Results When using the Purkinje alignment method, a physiological nasally positioning of the IOL can be observed. Aberrometry shows an increased spherical aberration but no increase of other HO aberrations. Conclusion Surgeon-controlled centration of IOL is possible with the BIL implantation technique. This opens new perspectives for further development and alignment of the optic. Commercial interest [source]


Potentiation of allergic bronchoconstriction by repeated exposure to formaldehyde in guinea-pigs in vivo

CLINICAL & EXPERIMENTAL ALLERGY, Issue 12 2003
T. Kita
Summary Background Indoor formaldehyde (FA) might worsen allergies and be an underlying factor for the increasing incidence and severity of asthma; the exact mechanism, however, remains unclear. Objective The present study examined the effects of repeated exposure to FA on methacholine- and antigen-induced bronchoconstriction in guinea-pigs in vivo. Methods First, non-sensitized guinea-pigs were transnasally treated with 0.1 or 1.0% FA or saline three times a week for 6 weeks, and increasing concentrations of methacholine (50, 100, and 200 ,g/mL) were inhaled at 5-min intervals. Second, guinea-pigs pre-treated with transnasal administration of FA or saline using the same protocol were passively sensitized with anti-ovalbumin (OA) serum 7 days before antigen challenge. Third, guinea-pigs were actively sensitized with OA and pre-treated with transnasal administration of FA or saline using the same protocol. The lateral pressure of the tracheal tube (Pao) was measured under anesthesia and artificial ventilation. Results The antigen-induced increase in Pao in actively sensitized guinea-pigs was significantly potentiated by FA exposure in a dose-dependent manner. The dose,response curve of the methacholine-induced increase in Pao in non-sensitized guinea-pigs or of the antigen-induced increase in Pao in passively sensitized guinea-pigs was not altered by FA exposure. Transnasal administration of FA significantly increased the serum anti-OA homocytotropic antibody titre (IgG) as measured by the passive cutaneous anaphylaxis reaction in actively sensitized guinea-pigs. Conclusion The results suggest that repeated exposure to FA worsens allergic bronchoconstriction through enhancing antigen sensitization. [source]


Reasons for placement and replacement of restorations in student clinics in Manchester and Athens

EUROPEAN JOURNAL OF DENTAL EDUCATION, Issue 4 2000
V. Deligeorgi
Data on reasons for the placement and replacement of restorations provide insight into patterns of clinical practice. This study investigated reasons for the provision of restorations in student clinics at the Universities of Manchester and Athens. Using the methods first described by Mjör, data were collected in relation to all initial and replacement restorations placed in adult patients in the main teaching clinics in the 2 schools over a 3-month period. The principal reason for intervention was recorded, according to approved treatment plans. Data were collected on 2620 restorations, 1431 (55%) of which were placed in Manchester. Primary caries was the main reason for the placement of initial restorations: 82% in Athens and 48% in Manchester (p<0.001). The principal reason for restoration replacement was secondary caries, accounting for 54% in Manchester and 33% in Athens (p<0.001). Other differences between the schools, included the ratio of initial placement to replacement restorations (Manchester 1:1.1; Athens 1:0.6: p<0.01) and significantly more 2-surface class II restorations having been placed in Manchester (p<0.001). Class III and IV restorations predominated in Athens. It is concluded, despite the acknowledged limitations of the methods employed, that the patterns of placement and replacement of restorations and the use of materials differ between the dental schools of Manchester and Athens. The differences are considered to relate more to local patterns of dental disease and patient selection for student clinics than to any differences in teaching philosophy. Subsequent studies of the type reported, despite acknowledged limitations would provide insight into the impact on patient care of the teaching of new materials, techniques and treatment philosophies. [source]