Blister Area Research Articles

Midinfrared Laser Pancorneal Coagulation as a Method of Treatment for Painful Bullous Keratopathy

To evaluate the efficacy of midinfrared laser pancorneal coagulation (PCC) for the management of secondary painful bullous keratopathy (PBK) with poor visual potential. A single-center, nonrandomized, retrospective observational study was performed on 137 eyes (137 patients) with PBK that underwent midinfrared laser PCC and were followed up in our clinic during 2000 to 2010. Preoperatively and at follow-up visits, all the eyes underwent a standard ophthalmologic examination; concurrently, 36 of these underwent corneal optical coherence tomography (OCT) and Scheimpflug camera examination (SCE). The main criteria for the efficacy of the treatment included a profile of the patients' corneal syndrome-related complaints (pain, dryness, etc), presence of bullae and deepithelization, and changes in the corneal thickness (CT) and transparency, based on OCT and SCE data, respectively, whereas additional ones included visual acuity changes. During the 24-month follow-up period, 69.3% of the patients had no complaints (complete epithelization), whereas 10.9% and 3.6% complained of having dryness and residual pain, respectively; the rest exhibited a recurrent corneal syndrome with isolated blister and/or corneal erosion areas, which was successfully managed with an additional focal-pattern laser coagulation session. In the OCT and SCE subgroup, on the day-3, day-7, and month-24 visits, the mean CT statistically significantly decreased from baseline (1027.1 ± 239.5) to 737.6 ± 157.4 μm, 592.3 ± 96.4 μm, and was 617 ± 95.9 μm, respectively, whereas the mean optical density decreased from the baseline (72.5 ± 9.5) to 62.3 ± 7.8, 58.5 ± 8.7, and was 56.33 ± 8.1 Scheimpflug densitometry units, respectively. PCC is a simple procedure that provides prompt relief from pain for eyes that have PBK with poor visual potential due to the reduction in CT and significant resolution of bullae and edema.

An investigation into eddy current pulsed thermography for detection of corrosion blister

This letter reports an investigation into eddy current pulsed thermography (ECPT) for detecting corrosion blister in mild steel. The detection mechanisms for various types of damage were addressed based on their interaction with eddy current distribution and heat conduction. Experimental studies showed that the blister and ruptured blister area can be easily monitored using conventional thermograms from an infrared camera. Signal processing algorithms were investigated to obtain new features. Principal components analysis (PCA), independent components analysis (ICA) and fast Fourier transform (FFT) were compared in the performance of blister detection. It was found that peak time was the best way to detect the blister and the extent of peak time increase was in the following sequence: blister≫intact area>ruptured blister. Several features can be specially used to separate the ruptured blister.

Characterization of flow behavior of semi-solid slurries containing low solid fractions in high-pressure die casting

Understanding the flow behavior of semi-solid slurries containing low solid fractions is key to the success in applying this process in the die casting industry. With these low initial solid fractions, the flow behavior of semi-solid slurries is quite complicated, making it difficult to model accurately. This present work developed and studied characterization methods for the flow behavior of semi-solid slurries at low solid fractions in high-pressure die casting. A new parameter, the ratio of gate speed to initial solid fraction (Vg/fs), was proposed to be correlated to the normalized flow interface length, blister area and tensile properties. Results from the flow pattern analysis suggest that the flow behavior can be controlled to achieve laminar flow by varying the initial solid fraction. Blister test results show the trend that slurry die casting conditions with high Vg/fs values exhibit high blister areas. Die casting conditions with excessively high gate speeds and insufficient solid fractions result in turbulent flow patterns and high levels of blister defect. The results of tensile test and fracture surface analysis are consistent with other analysis results. The samples formed by liquid die casting and slurry die casting with high Vg/fs values have gas porosity due to turbulent flow pattern during die filling. On the other hand, the samples formed by slurry die casting with too low Vg/fs values contain shrinkage porosity. This is because of insufficient time for shrinkage feeding due to a combination of a high solid fraction and a low gate speed. This study has demonstrated that die casting with slurries containing low initial solid fractions gives die casters another process parameter to adjust, which can help reduce and control the gas and shrinkage porosities.

<I>In vitro </I>permeability of etch-and-rinse and self-etch adhesives used for immediate dentin sealing

To investigate the permeability of deep dentin following immediate sealing with different etch-and-rinse and self-etch adhesives (Single Bond 2, Adper Prompt L-Pop, Clearfil Protect Bond, Clearfil S3 Bond, G-Bond) and a dentin desensitizer (Gluma). Fluid-transport model was used to measure fluid conductance during and after application of adhesives. Polyvinylsiloxane impressions of bonded dentin were taken to monitor fluid transudation from the surface of the adhesives. The area and number of dentinal fluid droplets and/or blisters were calculated using image analysis. None of the adhesives were able to block fluid conductance completely. The fluid conductance values of the adhesives displayed the following statistical ranking (p<0.05): G-Bond≤Clearfil Protect Bond<Smear-layer-covered dentin<S3 Bond≤Single Bond 2≤Adper Prompt L-Pop<Gluma Desensitizer<Acid-etched dentin. Highly significant correlation was observed between the permeability of the tested adhesives and the area fraction of fluid droplets/blisters on the adhesive surfaces (r=0.99, p<0.01).

Risk of squamous cell carcinoma in junctional epidermolysis bullosa, non-Herlitz type: Report of 7 cases and a review of the literature

Squamous cell carcinoma (SCC) is the most severe complication and most common cause of death in patients with recessive dystrophic epidermolysis bullosa. The risk of developing SCC among patients with junctional epidermolysis bullosa (JEB) is unclear from the literature; however, in our center we noticed an unexpected number of SCCs among adult patients with JEB. To review all documented patients with JEB in whom an SCC developed, both from our epidermolysis bullosa (EB) center and those reported in the literature. A search in our EB registry documenting all JEB patients visiting our EB referral center from 1990 through 2010 revealed 7 JEB patients who developed 1 or more SCCs. A systematic literature search revealed 8 relevant articles documenting a total of 7 patients who developed an SCC. In our EB registry we found 7 patients with JEB who developed an SCC; these were all adults classified with non-Herlitz type JEB. The frequency of developing an SCC among adult JEB patients (n = 28) in our center was therefore 25%. In the literature, we found 7 case reports of JEB complicated by SCC (also classified as JEB, non-Herlitz type), bringing the total number of documented cases to 14. The first SCC in JEB patients developed at an average age of 50 years (median, 52 years; range, 28-70 years). In 9 of 14 cases, multiple primary SCCs occurred, with a total of 45 SCCs. The SCCs are most often located on the lower extremities, in areas of chronic blistering, long-standing erosions, or atrophic scarring. Three patients (21%) developed metastases and died on average 8.9 years after diagnosis of the initial SCC. This study was retrospective and the statistical analyses were based on a small number of patients. From their third decade, adult patients with JEB have an increased risk (1:4) of developing SCC on their lower extremities. The SCCs have a high recurrence rate and follow an aggressive course that results in death in 1 of 5 patients. We recommend annual checks of all JEB patients for SCC starting at 25 years of age.

Investigation of the influence of textiles and surface treatments on blistering using a novel simulant

Friction blisters occur when shear loading causes the separation of dermal layers. Consequences range from minor pain to life-threatening infection. Past research in blister formation has focused on in vivo experiments, which complicate a mechanics-based study of the phenomenon. A Synthetic Skin Simulant Platform (3SP) approach was developed to investigate the effect of textile fabrics (t-shirt knit and denim cottons) and surface treatments (dry and wet lubricants) on blister formation. 3SP samples consist of bonded elastomeric layers that are surrogates for various dermal layers. These layers display frictional and mechanical properties similar to their anatomical analogues. Blistering was assessed by the measurement of deboned area between layers. Denim caused greater blistering than did the t-shirt knit cotton, and both lubricants significantly reduced blister area and surface damage. A triglyceride-based lubricant had a more pronounced effect on blister reduction than corn starch. The triglyceride lubricant used with t-shirt knit cotton resulted in no blisters being formed. The performance of the 3SP approach follows previously reported frictional behavior of skin in vivo. The results of textile and surface treatment performance suggest that future 3SP iterations can be focused on specific anatomical sites based on application type.

Engrosamiento traqueobronquial producido por herpesvirus en un paciente con síndrome de Good

We describe an oligosymptomatic patient with Good syndrome (thymoma and hypogammaglobulinemia) in who a follow-up chest computed tomography showed circumferential tracheobronchial wall thickening. Bronchoscopy demonstrated tracheobronchitis with necrotic, vesicular and blister areas. The histopathological and immunohistochemical findings were compatible with herpes simplex virus infection. The therapeutical response to oral acyclovir was satisfactory.

Remote sensing of air blisters in concrete?FRP bond layer using IR thermography

Studies have been conducted to: (a) detect artificially induced blisters in the bond-line between FRP components and the RC beams and (b) evaluate the influence of air-voids on the flexural performance of FRP strengthened RC elements. The air-voids were introduced within the bond-line of the concrete elements and the reinforcing FRP. These air-voids were 2.04% and 5.29%, respectively, of the section contact area with the FRP. The blisters were identified remotely and clearly using active thermographic approach. Subsequently, the flexural RC elements were tested in four-point bending configuration and their moment–curvature behaviour was determined. It was noted that the trend variation for the levels of induced blisters was similar to the perfectly bonded beams with identical test geometry. However, due to the presence of air-voids, there appeared to be a curtailment of performance both in strength and ductility of the section as the area of blisters increased.

Anomalous friction at a ‘Janus interface’: the possible role of blisters

When a surface (glass, mica...) is silanized, the resulting hydrophobic sheet may be poorly stuck to the solid and ‘blisters’ can occur in water (without any gas phase). If a second, hydrophilic, surface is lying (in water) at a small distance D above, the blister may stick to the upper side, giving (a) an attraction between the walls (b) a transient mechanical bridge opposing shear. Assuming a Poisson distribution for the blister area, we predict a mechanical relaxation spectrum with a temperature dependent exponent β. If β∼1/2, this could account for some of recent results by Granick and coworkers on ‘Janus’ systems. It cannot, however, account for similar observations by the same group using thiol monolayers on silver, where the thiol/silver binding is usually considered as strong.

Interfacial degradation of epoxy coated silicon nitride

Silicon (Si) wafers passivated with a nitride film, fabricated by low-pressure chemical vapor deposition (LPCVD) and coated with epoxy were used as test specimens to characterize the interfacial degradation. For the sample preparation, the surface was examined by x-ray photoelectron spectrometry (XPS) and contact angle measurement. The stress test conditions were 121/spl deg/C and 100% relative humidity. Optical microscopy was used to monitor the growth of damage as a function of time. Results of electron microscopy and XPS indicate that two different failure modes exist at the interface. One type of degradation is etching of the silicon nitride, Si/sub 3/N/sub 4/ (SiN) film, which appears in the early stages of aging. In more severely etched areas, the concentration of oxygen (O) is quite high and surface cracks develop. The other degradation mechanism is the nucleation and growth of blisters. Phenomenologically, their common characteristics were observed to be rapid growth initially followed by gradual maturing. When a blister became sufficiently large that it could no longer sustain its shape, it collapsed. Often additional blistering propagated subsequently. Blister growth can be accelerated by condensed water that oxidizes the SiN film. Adhesion failure, in the presence of oxygen, is propagated by the degradation of the epoxy silane and SiN film. Precipitate, consisting primarily of sodium (Na), carbon (C) and oxygen (O) with sodium being the main constituent, formed in many of the damage locations. XPS confirmed that a significant source of sodium was the epoxy. Depending on the environmental conditions, the morphology of the precipitate changed. The growth kinetics of the interfacial damage in terms of geometrical properties was observed and statistically analyzed. It was shown that a two-parameter Weibull cumulative distribution function (cdf) could be used to represent the blister growth at each time interval. Naturally, the total blister area increased as the total number of blisters increased. Furthermore, the mean blister area as a function of time was estimated quite well by a power function; however, the scatter about the mean was rather significant. In fact, the statistical variability was sufficiently high throughout that further investigations are warranted. Although progress has been made toward an understanding of the growth kinetics of interfacial damage, the complex processes that compromise the mechanical and electrical integrity require further study.

Treatment and Analysis of a Paint Chip from “Water Lilies” a Fire Damaged Monet

ABSTRACTA museum fire in 1958 severely damaged a Monet “Water Lilies” (1916-1926) painting that was on display. The surface of the painting is very dark with areas of blistering and charring. Over the years, traditional techniques have been found to be ineffective at removal of the soot and char from the surface. The painting, which is now in the care of the New York University (NYU) Conservation Center of the Institute of Fine Arts, was the subject of a study to determine if atomic oxygen treatment could remove the soot and char without damaging the fragile painting underneath. For test purposes, a small chip of paint was removed from the edge of the painting by a conservator at NYU and supplied to NASA Glenn Research Center for atomic oxygen treatment and analysis. The diffuse spectral reflectance, at three locations on the paint chip, was monitored at intervals during the atomic oxygen treatment process. Photo documentation of the chip during treatment was also performed. The color contrast was calculated from the spectral reflectance data as a function of treatment duration. Results of the testing indicated that the contrast improved as a result of the treatment, and the differentiation of colors on the surface was significantly improved. Soot and char could be removed without visibly affecting the gross surface features such as impasto areas. These results indicate the feasibility for the treatment of the “Water Lilies” painting.

Large melanocytic nevi in hereditary epidermolysis bullosa

Large melanocytic nevi occurring in areas of former blistering in patients with hereditary epidermolysis bullosa (EB) pose a problem to the clinician with regard to prognosis and therapy because they may show clinical and histopathologic features strikingly resembling malignant melanoma. To investigate clinical and histologic criteria as well as the biologic behavior of these nevi, pigmented lesions of 12 patients (EB simplex, n = 1; junctional EB, n = 7; dystrophic EB, n = 4) of the Austrian EB registry were analyzed. Clinically, the nevi are up to palm sized, are initially very dark, and may exhibit stippled pigmentation and irregular borders that outline areas of former blisters. Over time they usually lose pigment, the surface gets papillomatous, and finally they acquire a shagreen-like appearance. Histopathologically, the nevi frequently exhibit a compound congenital or persisting nevus/pseudomelanoma pattern. Despite this combination of features, no malignant transformation of the nevi has been seen by us even after 20 years of prospective surveillance. Because nevi with these criteria do not fit in any of the known categories, we suggest the term EB nevi. (J Am Acad Dermatol 2001;44:577-84.)

Morphological changes of neural and vascular peptides in human skin suction blister injury.

Suction blister injury is an experimental model for the investigation of the possible derangement of dermal/epidermal interaction in injury. An extensive fibre network can be stained in skin using antisera to the pan-neuronal marker protein gene product 9.5 (PGP) and the sensory neuropeptide calcitonin gene-related peptide (CGRP), while microvessels are identifiable with antisera to the endothelial marker von Willebrand's factor (vWf) and the peptide endothelin (ET). To investigate the possible involvement of superficial cutaneous innervation and microcirculation during the repair process in injury, human skin biopsies taken at different times after suction blister injury were investigated by quantitative immunohistochemistry. Neural and endothelial changes were seen in both edge and blister areas. PGP- and CGRP-immunoreactive nerves showed an increase in both areas compared with control skin up to 6 h after injury, followed by a decrease which lasted until 72 h. This was followed by a gradual increase of both nerve types starting from the blister edge and lasting up to 8 days after injury when the values were similar to controls. Similarly, in the blister area of the skin, vWF-immunoreactive capillaries showed statistically significant increases between 0 and 6 h after injury, followed by a decrease at 12 and 18 h which was maintained up to 72 h. ET-1 immunoreactivity showed a similar, although more variable, pattern of changes. At the blister edge from 23 h onwards, both vWf and ET-1 immunoreactivities showed a second increase from the edge of the blister spreading towards the centre of the blister ahead of the nerve increase. This lasted up to 8 days, when vWf immunoreactivity showed a statistically significant increase compared with control skin. Generally the numerical increase observed at early time points was accompanied by a strong staining intensity, which reverted to a normal staining intensity at later time points. These results suggest that there is a reactive process for all immunoreactive elements in the early stages of injury, followed by changes indicative of neuronal and endothelial damage (depletion phase) and the subsequent repair process. The repair started with re-epidermalization from the blister edge, followed by revascularization and, lastly, by reinnervation of the tissue. These results indicate a close relationship between epidermis, blood vessels, and nerve fibres during the healing process which follows suction blister injury.

The constrained blister test for the energy of interfacial adhesion

The constrained blister test (CBT) was designed to measure the energy of interfacial adhesion ( y) of polymeric films and coatings. Theoretical analysis of the CBT established a relationship between blister growth and interfacial parameters of the form A(t) A(t0)=exp[βp2h ph-γ (t- t0)] where A(t) is the blister area at time t, p is the applied pressure, h is the spacer height, y is the energy of interfacial adhesion, and β is a dissipative coefficient which is also related to geometric factors. The validity of the theoretical model was tested using a rubber-based pressure sensitive adhesive (PSA) tape. The PSA tape was investigated as a function of the applied pressure and the spacer height. A value of 44 J/m2 was determined for the energy of interfacial adhesion. The dissipative coefficient, β, was found to vary with the applied pressure and the spacer height.

High-fluence he-implantation in Ni trapping, re-emission, and surface modification

Abstract Simultaneous measurements have been made of blister formation and gas re-emission during bombardment of Ni with 8–40 keV 3He+ at room temperature. It is shown that re-emission and blister formation start at the same critical fluence. An initial peak in the re-emission rate is correlated to a step in the total number of blisters. A more detailed analysis of the experimental data shows that the area contributing to gas re-emission is much larger than the blister area. This suggests the formation of an interconnected layer below the surface in which cracks at blister sites provide gas emission channels to the surface.

Cutaneous manifestations of disseminated cryptococcosis

• Five patients with disseminated cryptococcosis had lesions on the extremities resembling cellulitis, which evolved into areas of blistering and ulceration in three patients. All had underlying disease and were medically immunosuppressed. Disseminated cryptococcosis appears to present with cellulitis or herpes-like vesiculation more commonly than is currently appreciated. India ink preparations of aspirates from areas of cellulitis or Tzanck preparations from blisters may show characteristic organisms, and makes possible an immediate diagnosis of cutaneous cryptococcosis. If cutaneous infection is confirmed by performing biopsies and growing cultures, dissemination must be presumed and the patient treated with a full course of systemic antifungal therapy. With increasing awareness of cutaneous involvement, some cases of disseminated cryptococcosis will be diagnosed sooner, leading to earlier therapy and improved prognosis. (<i>Arch Dermatol</i>112:1734-1740, 1976)

Cutaneous Manifestations of Disseminated Cryptococcosis

Five patients with disseminated cryptococcosis had lesions on the extremities resembling cellulitis, which evolved into areas of blistering and ulceration in three patients. All had underlying disease and were medically immunosuppressed. Disseminated cryptococcosis appears to present with cellulitis or herpes-like vesiculation more commonly than is currently appreciated. India ink preparations of aspirates from areas of cellulitis or Tzanck preparations from blisters may show characteristic organisms, and make possible an immediate diagnosis of cutaneous cryptococcosis. If cutaneous infection is confirmed by performing biopsies and growing cultures, dissemination must be presumed and the patient treated with a full course of systemic antifungal therapy. With increasing awareness of cutaneous involvement, some cases of disseminated cryptococcosis will be diagnosed sooner, leading to earlier therapy and improved prognosis.

Vitamin E Treatment of Epidermolysis Bullosa

Three patients with dystrophic epidermolysis bullosa (DEB) were treated with vitamin E, with the result that bullae formation ceased. Measurement of collagenase activity in the blister areas revealed a reversion to normal collagenase activity after 30 days of vitamin E therapy. These findings tend to support the theory that DEB is influenced by the increase in the level of skin collagenase, and the increased collagenase activity directly influences blister formation.

Fixing Cation Interaction with Blister-Like Osmotic Swelling on Vermiculite Cleavages

AbstractThe shrinkage of osmotically swollen natural and artificial blisters on vermiculite cleavages by exchange saturation with fixing cations such as Cs+, Rb+, NH4+, and K+ was investigated by replica electron microscopy. Incomplete collapse of either the natural or artificially produced blisters occurred with Cs+, Rb+, and NH4+ saturation, while K+ saturation completely collapsed the artificially produced blisters but not the natural blisters. The reason for incomplete collapse with Cs+, Rb+ and NH4+ was the incomplete replacement (trapping in the flakes) of interlayer hydrated cations such as Na+ shown by electron probe microanalysis. Much less trapping occurred with K+ saturation. Na+ entrapment increased with increasing size and decreasing hydration of cations, i.e. Cs+ &gt;Rb+ &gt;NH4+ &gt;K+.Semiquantitative determination of Na+, by electron probe microanalysis, in vermiculite flakes near the edge revealed that 1 N CsCl entrapped as much as 45·6 per cent while 1 N KCl entrapped only 7·5 per cent. In general, more Na+ was entrapped by 1 N solutions than by dilute solutions. With 0·01 N KCl solution, the Na+ entrapment was only 4·4 per cent. The amount of Na+ at the center of the macroflakes was less than at the edge, apparently as a result of more CEC at frayed edges and (or) because of incomplete diffusion of Na+ to the center. Shrinkage of artificial blisters by K+ could thus be attributed to its more effective removal of the interlayer hydrated cations, whereas the other fixing cations were less effective. Natural blisters on vermiculite from Libby, Montana were not completely collapsed even by K+, apparently because the layer charge density was too low in the blister areas.

Blister Prevention: An Experimental Method

Abstract This study was to determine the effectiveness of a blister prevention method using cold water to cool hot-spots on the feet. Twenty-four recently graduated high school athletes served as subjects, 12 in the experimental group and 12 in the control group. The immediate application of cold water to potential blister areas (hot-spots) was the independent variable. The dependent variable was the number of fully developed blisters that appeared in the groups. Two hypotheses were tested. H1, the hypothesis of no significant difference between the number of hot-spots appearing in the experimental group as compared to the control groups, was accepted. H2, the hypothesis of a significant difference in the number of blisters developed in the experimental group as compared to the control group was accepted, being statistically significant beyond the .01 level. Implications from the findings as well as modifications of the procedures are discussed with particular emphasis being placed on replication before f...