Accuracy of a smartphone application for triage of skin lesions based on machine learning algorithms.

BACKGROUND: Machine learning algorithms achieve expert-level accuracy in skin lesion classification based on clinical images. However, it is not yet shown whether these algorithms could have high accuracy when embedded in a smartphone app, where image quality is lower and there is high variability in image taking scenarios by users. In the past, these applications were criticized due to lack of accuracy. OBJECTIVE: In this study, we evaluate the accuracy of the newest version of a smartphone application (SA) for risk assessment of skin lesions. METHODS: This SA uses a machine learning algorithm to compute a risk rating. The algorithm is trained on 131 873 images taken by 31 449 users in multiple countries between January 2016 and August 2018 and rated for risk by dermatologists. To evaluate the sensitivity of the algorithm, we use 285 histopathologically validated skin cancer cases (including 138 malignant melanomas), from two previously published clinical studies (195 cases) and from the SA user database (90 cases). We calculate the specificity on a separate set from the SA user database containing 6000 clinically validated benign cases. RESULTS: The algorithm scored a 95.1% (95% CI, 91.9-97.3%) sensitivity in detecting (pre)malignant conditions (93% for malignant melanoma and 97% for keratinocyte carcinomas and precursors). This level of sensitivity was achieved with a 78.3% (95% CI, 77.2-79.3%) specificity. CONCLUSIONS: This SA provides a high sensitivity to detect skin cancer; however, there is still room for improvement in terms of specificity. Future studies are needed to assess the impact of this SA on the health systems and its users.

Temperature-dependent impact of thermal aminolaevulinic acid photodynamic therapy on apoptosis and reactive oxygen species generation in human dermal fibroblasts.

BACKGROUND: Actinic keratoses (AKs) are generally accepted as common precursor lesions to invasive squamous cell carcinoma. Photodynamic therapy (PDT) is a common, in-office, field therapy modality used in the treatment of AKs. Clinical and laboratory observations have demonstrated that temperature modulation can affect PDT efficacy. OBJECTIVES: To demonstrate thermal PDT increases apoptotic cell death, and to investigate the mechanistic role of reactive oxygen species (ROS) free radicals in an in vitro human skin fibroblast model. METHODS: This study was completed using commercially available primary human skin fibroblasts treated with aminolaevulinic acid (ALA) at specific concentrations and controlled temperatures. Cell death, apoptosis and superoxide ROS levels were quantified. RESULTS: We found that thermal PDT with 0·5 mmol L(-1) ALA resulted in significant temperature-dependent increases in total apoptosis and superoxide ROS generation between 33 °C and 42 °C. CONCLUSIONS: Our results indicate that thermal PDT significantly increases apoptotic cell death through increased generation of superoxide ROS in a temperature-dependent manner.

Artificial skin for closure and healing of wounds created by skin cancer excisions.

BACKGROUND: A dermal regeneration template indicated for life-threatening third-degree burn injuries is a product with potential application to smaller wounds to aid in healing and closure of complex excision sites. OBJECTIVE: To assess the effectiveness of dermal regeneration template for closure of skin cancer excision sites that would have otherwise required complicated closures. METHODS: Five patients, 61-84 years old, with skin cancer surgery yielding a total of six wounds were treated with the dermal regeneration template to close and heal their wounds. RESULTS: Four of five patients had complete healing (five of six wounds) with cosmetically acceptable results. The one treatment failure was application of the dermal regeneration template over exposed skull where inadequate neodermis formed. Successful healing was observed in five complex skin cancer excision sites including two wounds in previously irradiated grafted skin, a large and deep temporal defect, a wide excision in the supraclavicular region, and an excision down to cartilage on the antihelix of the ear. No infections were noted, although in four of five patients prophylactic oral antibiotics (either erythromycin or cephalexin) were prescribed postoperatively for 1-2 weeks. CONCLUSION: The product simplified wound care, subjectively appeared to decrease pain and postoperative bleeding, and yielded cosmetically acceptable wound repair. Autografting was not necessary; wounds healed in 2-4 months by epithelialization over neodermis after removal of the silicone layer. Furthermore, the product was a convenient long-term dressing and healing device for wounds where complex repairs, autografts, and/or flaps would otherwise be considered for closure.

Prefilled syringes: safe and effective.

BACKGROUND: Preloaded syringes are time savers, but questions have arisen anecdotally about the risk of infection from this procedure and the possible loss of potency, especially when performed with buffered syringes. OBJECTIVE: To show that preloaded syringes do not develop colonies of bacterial organisms and to confirm that anesthetic potency is maintained for at least 2 weeks. METHODS: Thirty-six syringes were stored for a period of 2 weeks on a shelf in our clinical procedure area with no protection from heat or light. The majority of these were then cultured for bacteria and fungi and one of them was used on one of the authors to determine the potency of the anesthetic. RESULTS: Preloaded syringes do not appear to be prone to the development of bacterial contamination for at least a 2-week period and potency of the anesthetic is maintained. CONCLUSION: Preloaded syringes are time savers and are a safe modality for use in the practicing dermatology office.

Experimental rationale for treatment of high-risk human melanoma with zinc chloride fixative paste. Increased resistance to tumor challenge in murine melanoma model.

BACKGROUND: Fixed-tissue micrographic surgery (Mohs) of melanoma has been shown by retrospective analysis to improve 5-year survival. OBJECTIVES: To determine whether zinc chloride fixative paste acts as an immune adjuvant to increase host resistance to melanoma. METHODS: We performed a murine study using the poorly immunogenic B16 melanoma of C57Bl6J mice, and the more immunogenic K1735p melanoma of C3H/HeN mice. Tumors were treated with zinc chloride paste and excised 24 hours later (Group 1), or simply excised (Group 2). Mice were challenged 7 days later with injection of melanoma cells at a distant site, and tumor growth in this second site was followed. RESULTS: K1735p melanomas developed at the challenge site in 69% of mice treated with excision versus 32% of mice treated with zinc chloride fixation (P < 0.025). Development of B16 melanoma was not altered by zinc chloride fixation. CONCLUSION: Zinc chloride fixation of the more immunogenic K1735p melanoma increased resistance to subsequent tumor challenge, suggesting that zinc chloride fixative paste acts as an immune adjuvant.

Fibromyalgia syndrome in children and adolescents: clinical features at presentation and status at follow-up.

OBJECTIVES: To 1) describe the characteristic features of fibromyalgia syndrome (FS) in a pediatric population, 2) note similarities and differences with FS in adults, and 3) determine outcome after treatment. SETTING AND DESIGN: The Pediatric Rheumatology Clinic at the University of Rochester Medical Center is staffed by two pediatric rheumatologists and serves as a regional subspecialty referral service with approximately 450 annual patient visits, of which approximately 120 are initial evaluations. A retrospective medical record review from 1989 to 1995 was used to identify and describe the study population, and a structured telephone interview served to determine current status and response to treatment. RESULTS: A total of 45 subjects were identified (41 female; 42 white; mean age, 13.3 years), of whom 33 were available for telephone interview at a mean of 2.6 years from initial diagnosis (0.1 to 7.6 years). Of a possible 15 symptoms associated with FS, subjects reported a mean of 8, with >90% experiencing diffuse pain and sleep disturbance. Less frequent were headaches (71%), general fatigue (62%), and morning stiffness (53%). The mean cumulative number of tender points summed over all visits was 9.7 (of 18). Telephone interviews showed improvement in most patients, with a mean positive change of 4.8 on a self-rating scale of 1 to 10 comparing current status to worst-ever condition. CONCLUSIONS: FS in patients referred to a pediatric rheumatology clinic is characterized by diffuse pain and sleep disturbance, the latter being more common than that in adults. The mean number of tender points summed over all visits is fewer than the criterion of 11 established for adults at a single visit. The majority of patients improved over 2 to 3 years of follow-up.

On the carcinogenicity of cadmium by the oral route.

Cadmium and cadmium compounds are carcinogenic both by inhalation and by injection. For purposes of risk assessment, a prudent public health approach has been that, if a chemical has been demonstrated to be carcinogenic by one route, it should be considered carcinogenic by all routes. This policy has been questioned for several toxic metals including cadmium. After reviewing the literature on cadmium carcinogenicity and genotoxicity, we think that cadmium should be considered noncarcinogenic by the oral route. The bases for this decision included: (1) a database for genotoxicity of cadmium with more negative test results than positive results and with most positive results in in vitro tests, indicating that cadmium has limited genotoxicity; (2) some epidemiologic evidence of respiratory tract cancer and prostatic cancer in people occupationally exposed to airborne cadmium but no reliable evidence of gastrointestinal tract cancers in workers; and (3) a large dietary oncogenicity study in rats of cadmium chloride at several dose levels, including a maximally tolerated dose (50 ppm) in males, which showed no increase of tumors due to cadmium ingestion in all of the 19 tissues examined. The conclusion that an agent, which has been shown to be carcinogenic by one route of exposure, is not carcinogenic by a second route should be made only in the presence of robust data which indicate the lack of effect via the second route of exposure.

Comparative studies of the covalent binding of [14C]-2-chloro-4-acetotoluidide by liver and kidney slices of the starling.

In tissue slices of female starlings, binding of [14C]-2-chloro-4-acetotoluidide (CAT) radioactivity to liver proteins was almost five times greater than binding to kidney proteins after 2 h of incubation. Binding to protein of liver slices increased in a log linear fashion with increasing CAT concentrations. Binding to protein of kidney slices also increased with increasing concentrations but not in a log linear fashion. Mixed-function oxidase inhibitors, SKF 525-A and alpha-naphthoflavone, decreased binding to liver slices but did not affect binding to kidney slices. Anaerobic incubation conditions inhibited binding to both tissues. P-Hydroxymercuribenzoate and sodium cyanide did not affect the binding of radioactivity associated with [14C]-CAT to proteins of either liver or kidney slices. Diethyl maleate increased binding of the radioactivity to proteins of the kidney slices but not to liver slices. Cysteine also increased binding in kidney slices. Binding in liver slices did not increase significantly with cysteine. The cysteine-induced increase in protein binding in kidney slices did not appear to depend on the formation of sulfate from the metabolism of cysteine. There was no sex-dependent difference in starlings as to the binding of radioactivity in either liver or kidney slices. Male chicken kidney slices bound a much higher amount of radioactivity associated with [14C]-CAT than male starling kidney slices, while the liver slices bound comparable amounts. Male hamster liver slices bound much more radioactivity than did male starling liver slices. However, hamster kidney slices bound much less than did starling kidney slices.(ABSTRACT TRUNCATED AT 250 WORDS)

Characterization of covalent binding of [14C]-2-chloro-4-acetotoluidide to microsomes of starling liver and kidney.

In this study, we have characterized the covalent binding of [14C]-2-chloro-4-acetotoluidide (CAT) radioactivity to microsomes of starling liver and kidney. The maximal velocity (Vmax) of covalent binding and apparent Michaelis constant (Km) for both tissues were similar. The Vmax for liver and kidney were 52.8 and 68.9 pmol/min/mg protein, and the apparent Kms were 0.54 and 0.87 mM, respectively. The covalent binding of radioactivity to heat-denatured microsomes of liver and kidney was reduced by 62% and 15%, respectively. Incubation at 0 degrees C reduced the binding by 80% to liver and 70% to kidney microsomes. Absence of nicotinamide adenine dinucleotide phosphate (NADP) and molecular O2 reduced the binding to liver microsomes by 36 and 53%, as opposed to 28% increase and 26% decrease in binding to kidney microsomes, respectively. Inducers of cytochrome P450 monooxygenase (P450), phenobarbital, and 3-methylcholanthrene (3-MC), had opposite effects on the covalent binding of [14C]-CAT radioactivity to hepatic and renal microsomes. Phenobarbital increased the binding to hepatic microsomes by 100% and had no effect on binding to renal microsomes. 3-MC, on the other hand, increased the binding to kidney microsomes by threefold and had no effect on the binding to hepatic microsomes. SKF 525A, an inhibitor of P450, inhibited the binding to hepatic microsomes by 60% at 0.5 mM but failed to have any effect on binding to renal microsomes. alpha-Naphthoflavone, another inhibitor of P450, had no effect on the covalent binding of [14C]-CAT radioactivity to microsomes of either tissue.(ABSTRACT TRUNCATED AT 250 WORDS)

Role of mixed-function oxidases and non-protein sulfhydryl content in [14C]-2-chloro-4-acetotoluidide binding to liver and kidney in starlings.

The compound 2-chloro-4-acetotoluidide (CAT) is highly toxic to many avian species, including the starling. In our earlier work, we demonstrated the covalent binding of radioactivity from [14C]-CAT to liver and kidneys of the starling. In the present study, the effects of inducers of mixed-function oxidase (MFO) and non-protein sulfhydryl (NPSH) depletor on the total and covalent binding of [14C]-CAT radioactivity to liver and kidney of the starling were examined. The total and covalently bound radioactivity from [14C]-CAT to liver and kidney were decreased significantly in the starling pretreated with the MFO inducer, 3-methylcholanthrene. However, pretreatment with phenobarbital, another inducer of MFO, had no effect. Pretreatment with the inhibitor of MFO, SKF 525-A, reduced the covalent binding of [14C]-CAT radioactivity to liver but not to kidney. There was no reduction in the NPSH content of liver or kidney following intravenous administration of CAT (3.5 mg kg-1). Reduction of NPSH levels in the liver or kidney following treatment with diethyl maleate caused a significant increase in the covalent binding of [14C]-CAT to kidney but not to liver.

A new scalpel handle for the cutaneous surgeon.

A newly designed scalpel handle that bridges the gap between a standard #3 and a Beaver handle is presented.

The precision binocular loupe.

The binocular loupe has long been used by dermatologists to improve their visualization of skin disease and for fine surgical work. As more and more dermatologists perform sclerotherapy and laser surgery, the popularity of magnifying loupes will increase.

Basal cell epithelioma in black patients.

The occurrence of cutaneous carcinoma in black patients is an unusual phenomenon, with basal cell carcinoma being particularly uncommon. We present five cases of basal cell epithelioma in black patients collected from the Texas Medical Center to graphically illustrate the varied and often atypical clinical presentations of such tumors. This report supports recent series of basal cell epithelioma in black patients derived from retrospective chart reviews.

The epidermal nevus syndrome: case report and review.

A 33-year-old woman had multiple basal cell epitheliomas complicating a large, unilateral nevus sebaceus. Other unilateral epidermal nevi and a contralateral pigmentary nevoid disorder were noted on cutaneous examination. There were signs of skeletal, neurologic, and vascular involvement. This patient illustrates the unpredictable features of the epidermal nevus syndrome and the importance of close follow-up to manage attendant complications.