A reaction route graph analysis of the electrochemical hydrogen oxidation and evolution reactions

The reaction route (RR) graph approach recently developed by us for complex, non-linear kinetic mechanisms is applied to the hydrogen oxidation and evolution reactions. A corresponding RR graph is constructed and translated into an equivalent electrical circuit network by associating each elementary step with a characteristic resistance for the steady-state case and considering the overall reaction as a power source. It is further shown that the steady-state kinetics of the reaction can be investigated employing the conventional methods of the electrical network theory. Using a set of rate constants for the hydrogen evolution reaction (her) in alkaline solutions from the literature, the dominant RRs are identified and simplified mechanisms and kinetics derived.     

Aspergillus Iris Granuloma: A Case Report with Review of Literature

We report the case of a 25-year-old male patient who presented with complaints of redness, photophobia, and decreased vision in the right eye of a week's duration. Slit-lamp biomicroscopic examination revealed a cream-colored, irregular elevated inferior iris mass, extending on to the anterior lens surface. Differential diagnoses of a fungal granuloma, a medulloepithelioma, and an amelanotic melanoma were considered. An excisional biopsy of the mass was performed through a superior clear corneal incision. Polymerase chain reaction analysis of the aqueous humor showed a positive pan fungal genome. Histopathology of the biopsied mass showed a giant cell granuloma with surrounding numerous branching, septate hyphae. Culture growth revealed Aspergillus fumigatus We report this case because of the rarity of Aspergillus iris granuloma as a primary presentation of endogenous Aspergillosis and review the relevant literature. Absence of a significant systemic history compounded the diagnostic dilemma in our patient. Definitive differentiation of this rare entity from a foreign body, amelanotic melanoma, and other inflammatory conditions such as sarcoidosis and tuberculosis, may be possible only on microbiological and histo-pathological evaluation.     

Clinical Experience with Light-Emitting Diode (LED) Photomodulation

Background. Light-emitting diode (LED) photomodulation is a novel nonthermal technology used to modulate cellular activity with light.
Objective:. We describe our experience over the last 2 years using 590 nm LED photomodulation within a dermatologic surgery environment.
Methods. Practical use of nonthermal light energy and emerging applications in 3,500 treatments delivered to 900 patients is detailed.
Results. LED photomodulation has been used alone for skin rejuvenation in over 300 patients but has been effective in augmentation of results in 600 patients receiving concomitant nonablative thermal and vascular treatments such as intense pulsed light, pulsed dye laser, KTP and infrared lasers, radiofrequency energy, and ablative lasers.
Conclusion:. LED photomodulation reverses signs of photoaging using a new nonthermal mechanism. The anti-inflammatory component of LED in combination with the cell regulatory component helps improve the outcome of other thermal-based rejuvenation treatments.     

Improvement of Atrophic Acne Scars with a 1,320 nm Nd:YAG Laser: Retrospective Study

Background. Facial acne scarring has been treated with multiple methods with varying degrees of improvement. Although the 1,320 nm neodymium:yttrium-aluminum-garnet (Nd:YAG) laser has been widely used to improve photoaging, studies analyzing its effects on atrophic acne scarring are limited.
Objective. To evaluate the efficacy of a dynamic cryogen-cooled 1,320 nm Nd:YAG laser for the treatment of atrophic facial acne scars in a larger cohort of patients with long-term follow-up.
Methods. Twenty-nine patients (skin phototypes I–IV) with facial acne scarring received a mean of 5.5 (range 2–17) treatments with a 1,320 nm Nd:YAG laser. Objective physician assessment scores of improvement were determined by side-by-side comparison of preoperative and postoperative photographs at a range of 1 to 27 months (mean 10.4 months) postoperatively. Subjective patient self-assessment scores of improvement were also obtained.
Results. Acne scarring was significantly improved by both physician and patient assessment scores. Mean improvement was 2.8 (  p < .05  ) on a 0- to 4-point scale by physician assessment and 5.4 (  p < .05  ) on a 0- to 10-point scale by patient assessment. No significant complications were observed.
Conclusions. Nonablative laser skin resurfacing with a 1,320 nm Nd:YAG laser can effectively improve the appearance of facial acne scars with minimal adverse sequelae.     

Improvement of Dermatochalasis and Periorbital Rhytides With a High-Energy Pulsed CO2 Laser: A Retrospective Study

Background. Upper eyelid dermatochalasis is typically treated with excisional blepharoplasty. The role of the CO₂ laser previously had been confined to that of a vaporizing, incisional, or hemostatic tool. Over the past several years, however, ablative CO₂ laser skin resurfacing has been popularized as an adjunctive treatment to blepharoplasty to minimize periorbital rhytides through its vaporizing as well as skin-tightening action.
Objective. To evaluate the safety and efficacy of a high-energy pulsed CO₂ laser as a stand-alone treatment for dermatochalasis and periorbital rhytides.
Methods. Sixty-seven patients (skin phototypes I–IV) with mild-to-severe upper eyelid dermatochalasis and periorbital rhytides received periocular CO₂ laser skin treatment. Global assessment scores of dermatochalasis and rhytides were determined by a side-by-side comparison of periocular photographs preoperatively and 1, 3, and 6 months postoperatively. In addition, caliper measurements of upper eyelids before and 1, 3, and 6 months after treatment were obtained.
Results. Both dermatochalasis and periorbital rhytides were significantly improved after periocular CO₂ laser skin resurfacing. Patients with more severe dermatochalasis and rhytides showed greater improvement after CO₂ laser treatment than did those with mild or moderate involvement. Side effects were limited to erythema and transient hyperpigmentation. No scarring, hypopigmentation, or ectropion were observed.
Conclusions. Periocular skin resurfacing with a CO₂ laser can safely and effectively improve upper eyelid dermatochalasis and periorbital rhytides.     

Differential Effects of Immunosuppressive Drugs on T-Cell Motility

The best-characterized mechanism of the action of immunosuppressive drugs is to prevent T-cell clonal expansion, thus containing the magnitude of the ensuing immune response. As T-cell recruitment to the inflammatory site is another key step in the development of T-cell-mediated inflammation, we analyzed and compared the effects of two commonly used immunosuppressants, cyclosporin A (CsA) and the rapamycin-related compound SDZ-RAD, on the motility of human CD4+ T cells. We show that CsA, but not SDZ-RAD, inhibits T-cell transendothelial migration in vitro. CsA selectively impaired chemokine-induced T-cell chemotaxis while integrin-mediated migration was unaffected. The inhibition of T-cell chemotaxis correlated with reduced AKT/PKB but not ERK activation following exposure to the chemokine CXCL-12/SDF-1. In addition, CsA, but not SDZ-RAD, prevents some T-cell receptor-mediated effects on T-cell motility. Finally, we show that CsA, but not SDZ-RAD inhibits tissue infiltration by T cells in vivo. Our data suggest a prominent antiinflammatory role for CsA in T-cell-mediated tissue damage, by inhibiting T-cell trafficking into tissues in addition to containing clonal expansion.