Effect of frequency on entrance and propagation pattern of high-frequency (radiofrequency) electrical currents in biologic tissues.

BACKGROUND: Radiofrequency electrical currents have a tendency to move toward the center of the bulk of biologic tissues. OBJECTIVES: To evaluate the effect of the frequency of currents on their entrance and propagation pattern in biologic tissues. MATERIALS AND METHODS: Three electrosurgical generators with 0.4, 1.5, and 3 MHz frequency outputs were studied. Current was applied using a metallic needle introduced into a piece of cow liver, with different amounts of energy delivered at multiple points. Cross-sections of the liver were then studied for tissue effect. The diameters of the coagulated areas at the deepest and most superficial parts were measured. The tendency of the currents for penetration in the deeper layers of tissue rather than in the superficial layers was assessed using the superficial diameter/deep diameter ratio. RESULTS: Diameter of coagulated area was larger around deeper parts than around superficial parts of the electrode. No correlation between frequency of current and the superficial/deep diameter ratio of the coagulation zone was found. CONCLUSION: Radiofrequency currents have a tendency to move toward the center of the tissue. Frequency of current over the range of 0.4-3 MHz did not show any effect on this tendency.

Entrance and propagation pattern of high-frequency electrical currents in biological tissues as applied to fractional skin rejuvenation using penetrating electrodes.

BACKGROUND: Fractional resurfacing of the skin using radiofrequency devices has been used for collagen remodeling and rejuvenation. OBJECTIVES: To determine how radiofrequency current enters and propagates through tissue, and the pattern of the resulting effect. MATERIALS AND METHODS: An electrosurgical device with a 0.4 MHz frequency output was used as the source of radiofrequency current. Current was applied via a metallic needle introduced into a large piece of cow liver, with different amounts of energy delivered at multiple points. Cross-sections of the liver were then studied for tissue effect. RESULTS: Thermal coagulation of tissue started from the tip of the electrode. With higher energy, a rim of coagulated tissue formed around the entire length of the needle. This rim of coagulated tissue was thicker around the tip of the electrode. CONCLUSION: Radiofrequency currents have a tendency to move toward the center of the bulk of tissue. When an electrode of a fractional radiofrequency device enters the skin, maximum heating effect will be around the tip of the electrode in the dermis. This phenomenon can preserve epidermis from injury during dermal heating, reducing post-procedural skin surface side effects seen with many skin rejuvenation procedures.

Midfacial analysis and planning for midface augmentation with injectable filling materials: an anatomical approach.

BACKGROUND: Midfacial augmentation improves the appearance of patients with flat or ptotic cheek. OBJECTIVES: To develop a simple method of preoperative delineating the location of the ideal malar prominence and determining the best area to augment with injectable filling materials. METHODS: We used detailed analysis of the facial features of some Caucasian men and women as the basis for this study. RESULTS: We described a technique to locate the ideal malar prominence and proposed a classification of midfacial contour defects. CONCLUSION: This method greatly simplifies the surgeon's task of determining the area to be augmented.

Teaching emotional intelligence to intensive care unit nurses and their general health: a randomized clinical trial.

BACKGROUND: Emotion and how people manage it is an important part of personality that would immensely affect their health. Investigations showed that emotional intelligence is significantly related to and can predict psychological health. OBJECTIVE: To determine the effect of teaching emotional intelligence to intensive care unit nurses on their general health. METHODS: This randomized clinical trial (registered as IRCT201208022812N9) was conducted on 52 of 200 in intensive care unit nurses affiliated to Shiraz University of Medical Sciences. They were recruited through purposeful convenience sampling and then randomly categorized into two groups. The intervention group members were trained in emotional intelligence. Bar-on emotional intelligence and Goldberg's general health questionnaires were administered to each participant before, immediately after, and one month after the intervention. RESULTS: While the mean score of general health for the intervention group decreased from 25.4 before the intervention, to 18.1 immediately after the intervention and to 14.6 one month later, for the control group, it increased from 22.0, to 24.2 and to 26.5, respectively (p<0.001). CONCLUSION: Teaching emotional intelligence improved the general health of intensive care unit nurses.

Desmoglein 1 and 3 enzyme-linked immunosorbent assay in Iranian patients with pemphigus vulgaris: correlation with phenotype, severity, and disease activity.

BACKGROUND: Pemphigus vulgaris (PV) is a chronic autoimmune blistering disorder of the skin and mucosa characterized by the presence of autoantibodies against desmoglein3 (Dsg3). Some patients also have antibodies against desmoglein1 (Dsg1). The aims of this study were to evaluate the diagnostic value of Dsg enzyme-linked immunosorbent assay (ELISA) in Iranian PV patients, to assess its correlation with the clinical phenotype and severity of disease and to investigate the changes of these antibodies after treatment. METHODS: Seventy-three patients with PV (29 men, 44 women) presenting to the Pemphigus Research Unit at Razi Hospital, Tehran, Iran were enrolled. ELISAs were used to detect IgG autoantibodies reactive with the ectodomains of Dsg1 and Dsg3, and the correlation of antibodies with the clinical phenotype as well as oral and skin disease severity was assessed. In addition, the tests were repeated in 18 patients after treatment and the resulting remission. RESULTS: Anti-Dsg1 and anti-Dsg3 were detected in 56 (76.7%) and 69 (94.5%) patients, respectively. Anti-Dsg1 and anti-Dsg3 antibodies were present in 48 (94.1%) and 50 (98%) patients with mucocutaneous type, in 2 (12.5%) and 15 (93.7%) patients with mucosal type, and in 6 (100%) and 4 (66.7%) patients with cutaneous PV, respectively. The mean anti-Dsg1 index values were significantly higher in cutaneous and mucocutaneous phenotypes than mucosal PV (P < 0.001). The mean anti-Dsg3 index values were significantly lower in cutaneous and mucosal phenotypes than mucocutaneous PV (P < 0.01). The severity of skin lesions (but not oral lesions) was correlated with anti-Dsg1 antibody level (P < 0.001); on the other hand, the severity of oral lesions (P < 0.01) as well as skin lesions (P < 0.001) was significantly correlated with anti-Dsg3 antibody levels. Both anti-Dsg1 and anti-Dsg3 levels were significantly reduced after treatment and clinical remission (P < 0.001). CONCLUSION: Dsg ELISA is not only a sensitive tool for the diagnosis of PV, it can also serve as a predictive means for assessing the severity as well as for monitoring the disease activity. Although, in general, the clinical phenotype is related to the antibody profile, there are occasional cases with discordant phenotype and antibody profile. These discrepancies might be explained by genetic variations or the presence of possible minor antigens involved in the pathogenesis of pemphigus.

Naevus comedonicus of the scalp.

We report the case of a 3-year-old boy with naevus comedonicus, characterized by confluent clusters of dilated follicular orifices plugged with keratinous material that resemble open comedones, located on the scalp.

Comparison of cryotherapy and curettage for the treatment of pyogenic granuloma: a randomized trial.

BACKGROUND: Pyogenic granuloma is a benign vascular lesion of the skin and mucous membranes. Many different treatments have been used, with variable success rates. OBJECTIVES: To evaluate and compare the effects of cryotherapy and curettage in the treatment of pyogenic granuloma. METHODS: Eighty-nine patients with pyogenic granuloma were randomized to receive cryotherapy with liquid nitrogen or curettage and electrodesiccation. Forty patients in the cryotherapy group and 36 patients in the curettage group completed the study period. RESULTS: Among the patients who completed the study, treatment resulted in complete resolution of all lesions after one to three sessions (mean 1.42) in the cryotherapy group and after one to two sessions (mean 1.03) in the curettage group. The difference between the two groups was statistically significant (P < 0.001). Twenty-three patients (57.5%) in the cryotherapy group and 25 patients (69%) in the curettage group had no scar or pigmentation abnormality. Except for cosmetic problems, no other side-effect or complication was recorded in the study. CONCLUSIONS: This study showed that both cryotherapy and curettage are safe and effective. Curettage had the advantage of fewer treatment sessions required to achieve resolution and better cosmetic results. We suggest that curettage could be the first-line treatment for pyogenic granuloma.

Cryotherapy in the treatment of pyogenic granuloma.

BACKGROUND: Pyogenic granuloma is a benign, acquired, proliferative vascular lesion of the skin and mucous membranes. Many different treatments have been used for pyogenic granuloma with variable success rates. OBJECTIVE: To evaluate the efficacy of cryotherapy in the treatment of pyogenic granuloma. METHODS: In a prospective observational study, 135 patients with pyogenic granuloma were treated with cryotherapy using liquid nitrogen. The patients were followed up every 3 weeks until 3 months after disappearance of the lesion. RESULTS: Complete resolution of the pyogenic granuloma was achieved in all patients after a mean of 1.58 treatments (range, 1-4 treatments). At the end of follow-up period, there was a flat imperceptible scar, smaller than the treated lesion, in 16 patients (11.8%). A hypertrophic scar, 3 mm in diameter, was observed in one patient. Hypopigmentation was observed in seven patients (5.1%). No other complication or side-effect was recorded in the study. CONCLUSIONS: We believe that pyogenic granuloma can be treated simply and effectively with cryotherapy.

Silver nitrate cautery in aphthous stomatitis: a randomized controlled trial.

BACKGROUND: Aphthous stomatitis is a painful, recurrent disease of the oral mucous membrane. Silver nitrate sticks have been used for a long time to provide pain relief for the duration of an aphthous ulceration, with only one application. Silver nitrate causes chemical cauterization and increases the depth of injury. OBJECTIVES: To study the effect of chemical cautery with silver nitrate in reducing pain of aphthous ulceration and to determine if this treatment shortens or prolongs healing. METHODS: In a randomized, patient-blinded, placebo-controlled study, 97 patients with painful minor oral aphthous ulceration were randomized to receive silver nitrate cautery or placebo. The severity of pain was rated on a three-category scale (severe, mild, none) and was recorded each day until the seventh day after the procedure. The lesion size was recorded at the time of the procedure and on the seventh day afterwards. In the treatment group, the ulcer was gently painted with a silver nitrate stick until it turned white. In the placebo group, the ulcer was gently painted with a placebo stick. RESULTS: In the treatment group, 33 of 47 patients (70%) evaluated and in the placebo group, four of 38 patients (11%) evaluated had reduction in severity of pain 1 day after the procedure. The difference was statistically significant (P < 0.001). On the seventh day after the procedure, the ulcers were completely re-epithelialized in 39 patients (83%) in the treatment group and in 34 patients (89%) in the placebo group. The difference was not statistically significant (P = 0.39). CONCLUSIONS: The results of our study showed that one application of silver nitrate can decrease the severity of pain in aphthous ulceration without significantly shortening or prolonging healing time. We did not observe any side-effects in our study. The effect is rapid and lasts for the duration of the lesion. The treatment is simple and cost-effective in patients with infrequent recurrences.