Cotton thread method for measuring tear secretion, suitable for soft contact lens wearers (method no. 3)

Two methods of measuring lacrimation with a cotton thread and fluorescein have been described hitherto. Method 3 is intended for testing lacrimal flow in wearers of soft contact lenses. Fluorescent paper can be used to facilitate the measuring procedure. The method has been shown to be reliable in numerous control tests on subjects with normal eyes and in comparisons with the authors' methods 1 and 2. With the test, values of less than 5 mm indicate severe lacrimal deficiencies.     

Multifocal ERG with the scanning laser ophthalmoscope: query on the ideal configuration for attaining high resolution and result stability

Graefe's Archive for Clinical and Experimental Ophthalmology -     

Analysis of three-dimensional sinter shrinkage of copings made from alumina in an innovative direct shaping process.

The three-dimensional (3D) evaluation and comparison of free-form-surfaces is a complex problem [Dent. Mater. 8 (1992) 49; J. Dent. Res. 76 (1997) 1799; Dent. Mater. 16 (2000) 145; J. Prosthet. Dent. 70 (1993) 457; Dent. Mater. 19 (2003) 19]. However, it is essential in order to analyze the sinter shrinkage of dental ceramic-restorations where isotropic and linear shrinkage is desired for accurate fit on the prepared teeth. In this article, we examine the 3D sinter shrinkage in general and for nine copings from alumina in particular. Using various scaled CAD-models in an iteration scheme, each model was compared to the filtered point cloud of the coping, determining the surface-cloud difference. The magnitude of deviations from linear sinter shrinkage was investigated. Furthermore, a new fabrication process for ceramic-restorations is introduced.     

The reduction of methemoglobin levels by antioxidants

Preventing the oxidation of hemoglobin in solution is one of the major requirements for the successful production and long-term storage of hemoglobin-based blood substitutes. To this end we have studied the effects of antioxidants on the rate of methemoglobin formation and disappearance in solutions of human and bovine hemoglobin at 4 degrees C and 37 degrees C. Ascorbate and desferal (5 mM) were observed to act as prooxidants, increasing the rate of methemoglobin formation at 37 degrees C. Trehalose, mannitol, glucose, and EDTA (5 mM) had no significant effect. Glutathione and NADH (10 mM) were the most effective antioxidants tested, causing a significant decrease in the rate of methemoglobin formation at 37 degrees C for periods of up to 50 hours. The combination of these antioxidants in bovine hemoglobin at 4 degrees C resulted in the reduction of methemoglobin levels to nearly undetectable levels in approximately 150 hours. In addition, NADH and glutathione were found to reduce methemoglobin levels to 10% over a period of 100 hours in a sample of human hemoglobin that had been stored at 4 degrees C for one year and had 60% methemoglobin. These results suggest that the prevention and reversal of methemoglobin formation during the long-term storage of hemoglobin solutions and hemoglobin-based blood substitutes may now be possible.     

Construct Validity of a Clinical-performance-evaluation Tool in Community Health Nursing

An evaluative research study was conducted to examine the construct validity and applicability of a selected clinical-performance-evaluation tool. The tool was designed for baccalaureate students in a community health nursing course. Eighteen senior students functioning in two urban clinical agencies participated in the study. Data were collected at two evaluation points over one semester. Results indicated strong support for construct validity of the tool. This finding suggests a high level of correlation between theoretical concepts and clinical practice. Recommendations for use of the clinical performance evaluation tool are discussed.     

Rush Hymenoptera venom immunotherapy: a safe and practical protocol for high-risk patients

BACKGROUND: Hymenoptera venom immunotherapy in allergic patients is a well-established treatment modality for the prevention of systemic anaphylactic reactions caused by insect stings. A variety of therapy regimens exists, from conventional to rush and ultrarush modalities that operate on continuous or intermittent schedules. OBJECTIVE: The aim of this study was to report the 8-year experience with our rush venom immunotherapy regimen in predominantly high-risk patients and to compare data on safety and convenience with the results of 26 studies published from 1978 to 2001. METHODS: One hundred one patients allergic to bee, yellow jacket, or hornet venom were treated with rush Hymenoptera venom immunotherapy. Diagnosis and selection of patients for venom immunotherapy were carried out according to the recommendations of the European Academy of Allergology and Clinical Immunology. We used a 4-day regimen, and the incidence and nature of systemic reactions (SRs) were documented. Fifty-two patients were treated with honeybee venom, and 49 were treated with yellow jacket venom. RESULTS: One hundred (99%) patients reached the maintenance dose. We observed 8 injection-related SRs (0.47% of all injections given) in 7 (6.9%) patients. The number of SRs was higher in patients treated with bee venom extract (12%) compared with in patients receiving yellow jacket venom extract (2%). There was no significant difference in the risk of SRs between female and male patients. The incidence of SRs was considerably lower than the average of 17.8% reported in the literature. CONCLUSION: With a rush immunotherapy regimen over a time period of 8 years in predominantly high-risk patients, the incidence of SRs was low, despite the high number of patients with bee venom allergy, who are more likely to have side effects. Epinephrine as rescue medication was never necessary, and the regimen proved to be safe and convenient for both the patients and the medical staff.     

Hereditary Cerebral Hemorrhage with Amyloidosis-Dutch Type (HCHWA-D): I - A Review of Clinical, Radiologic and Genetic Aspects

Hereditary cerebral hemorrhage with amyloidosis - Dutch type (HCHWA-D) is an autosomal dominant disease caused by deposition of β-amyloid in the leptomeningeal arteries and cortical arterioles, in addition to preamyloid deposits and amyloid plaques in the brain parenchyma.
The disease is due to a point mutation at codon 693 of the amyloid precursor protein (βPP) gene at chromosome 21. Since this point mutation is diagnostic for HCHWA-D, presymptomatic testing is feasible and offered, together with genetic counselling and psychological support, to subjects at risk. HCHWA-D is clinically characterized by recurrent strokes, in addition to dementia, which can occur after the first stroke but also preceding it. Radiological studies revealed focal lesions (hemorrhages, hemorrhagic and non-hemorrhagic infarctions) and diffuse white matter damage. Diffuse white matter hyperintensities on MRI are an early symptom of HCHWA-D since they have been found on MRI scans of subjects who had not suffered a stroke.
The presence of the diagnostic point mutation makes HCHWA-D a useful model to study the effects of cerebral amyloid angiopathy in vivo. The characteristic pathological abnormalities and its implications for Alzheimer's disease will be discussed in Part II of this article