Levels Of Glutaraldehyde Research Articles

Mechanical properties and shape memory effect of thermal-responsive polymer based on PVA

In this study, the effect of content of glutaraldehyde (GA) on the shape memory behavior of a shape memory polymer based on polyvinyl alcohol chemically cross-linked with GA was investigated. Thermal-responsive shape memory composites with three different GA levels, GA-PVA (3 wt%, 5 wt%, 7 wt%), were prepared by particle melting, mold forming and freeze–drying technique. The mechanical properties, thermal properties and shape memory behavior were measured by differential scanning calorimeter, physical bending test and cyclic thermo-mechanical test. The addition of GA to PVA led to a steady shape memory transition temperature and an improved mechanical compressive strength. The composite with 5 wt% of GA exhibited the best shape recoverability. Further increase in the crosslinking agent content of GA would reduce the recovery force and prolong the recovery time due to restriction in the movement of the soft PVA chain segments. These results provide important information for the study on materials in 4D printing.

Indoor Glutaraldehyde Levels in the Endoscope Disinfecting Room and Subjective Symptoms among Workers

We measured the environmental glutaraldehyde (GA) levels during the disinfection of endoscopes and also investigated the subjective symptoms of the workers engaged in that work. At 6 hospitals in the Tokyo and Kanagawa area, 8 rooms for endoscope washing and disinfecting the endoscopy equipment were surveyed. The geometric mean environmental GA levels in the 8 rooms were 1.3 to 19.6 ppb. The personal exposure levels at the time of replacing the antiseptic solution containing GA in two of the disinfecting rooms were 94.2 and 84.9 ppb. Subjective symptoms such as ophthalmic, nasal, respiratory, pharyngeal symptoms and nausea were more prevalent among workers than controls as evidenced from the questionnaire survey.

Preservation of the non-rectangular cuticular plate/cell axis angle of outer hair cells.

Motile properties of outer hair cells (OHCs) may contribute to sharp tuning and amplification in the mammalian cochlea. Shape changes of isolated OHCs in response to various physical and chemical influences have been investigated intensively. However, determinations of shape may have been influenced by unanticipated effects of preparation and preservation of the OHCs investigated. Thus, in a first step, lengths of freshly isolated OHCs from the guinea pig cochlea were determined using a video-enhancing magnification system. The cuticular plate/cell axis angle (CP/CA angle) was then measured in native cells and under the influence of potassium chloride and potassium gluconate incubation. To show the influence of glutaraldehyde (GA) fixation on the isolated OHCs, fixative-dependent changes on cell length and CP/CA angle were recorded in native and preincubated OHCs. In these experiments, the cell length of vital isolated OHCs was between 41.5 micrometers, in the basal turn, and 103.7 micrometers, in the apical turn. The average CP/CA angle was 106 degrees +/- 4.2 degrees (n = 324 cells, turns 1-4) with no statistically significant differences for the four turns. Under the influence of potassium chloride, cell length was reduced by 8.1%. Potassium gluconate incubation led to a shortening of cell length, followed by a 5.3% increase after 5 min. The CP/CA angle under potassium chloride was decreased (97.0 degrees) and was then increased under the influence of potassium gluconate (110.7 degrees) as a result of cuticular plate tilting. Cell shrinkage after fixation depended on the fixative's osmolarity and on the GA concentration. Increased GA levels amplified cell shrinkage from 34% for hypo-osmolar solutions to 15% in iso-osmolar and 29% in hyperosmolar solutions. The CP/CA angle of native and incubated OHCs was not different from those fixed with GA. The present data provide a rational basis for isolated OHC shape parameters. Moreover, functionally induced changes can be better interpreted when OHCs are influenced by fixatives, as shown in the GA experiments.

Dose response relationships in allergic contact dermatitis: Glutaraldehyde‐containing liquid fabric softener

Glutaraldehyde (GTA) is an effective preservative in some consumer products. Because it is a weak cutaneous allergen at certain concentrations, studies were conducted to assess any potential hazard of adding a low level (550 ppm) of GTA to an experimental liquid fabric softener. Allergic contact dermatitis (delayed hypersensitivity) was not elicited in challenge tests of 16 GTA-sensitive subjects or in repeated insult patch tests of 706 normal human male and female subjects. The subjects were exposed (1) to the experiment formulation, (2) to the formulation with 10 times the normal level of GTA, and (3) to fabrics laundered with the normal use level or with 10 times the normal use level of these experimental formulations.