bluuebunny/crossref_metadata_2025 huggingface dataset:
Fracture Toughness of PEI Modified Epoxy Resin CFRP Composites
Authors: Murakami A. , Shonaike G. O. , Ooishi K. , Watanabe O. , Takezawa M.
Published: July 2017

This paper describes the delamination toughness (GIC) of polyetherimide (PEI) modified epoxy resin reinforced with carbon fiber (CFRP). The epoxy resin was modified by using a thermoplastic PEI and cured with dicyanamine (Dicy). The modified resin was reinforced with cross-woven and uni-directional (UD) carbon fiber. The delamination toughness and impact tests were carried out by using a Double Cantilever Beam (DCB) testing procedure and Dynatup impact testing machine. GIC of PEI modified epoxy resin CFRP composite was about 2.5 times higher than the unreinforced PEI modified epoxy resin. However, GIc of cross-woven CFRP was higher than that of UD-CFRP. This was attributed to phase separation which occurred more easily in the cross-woven CFRP composite as a result of more space between the prepreg plies. The effect of PEI on impact energy is insignificant below 20 wt%. Thus the total energy absorbed was improved when the PEI content was 30 wt%. The impact damaged area as evaluated shows the damaged area of unmodified resin to be three times higher than the PEI modified CFRP composites. This indicates that the damage tolerance of the PEI modified CFRP was superior to that of the unmodified CFRP.
A Life Prediction Model for Metal Matrix Composites
Authors: Ahmad J. , Santhosh U. , Kinney S.
Published: July 2017

Global deformation response of metal matrix composites (MMCs) to applied mechanical and thermally induced stresses depends upon (1) the mechanical and thermal properties of the constituent materials, (2) residual stresses in the constituents induced by the composite consolidation process, and (3) the nature and extent of micromechanical damage which may occur and accumulate over time. In the present work, a mechanistic model for predicting time dependent global deformation response of unidirectional metal matrix composite subjected to fiber direction stresses is used in conjunction with several viscoplastic models for the matrix, viz. power law, Bodner-Partom and GVIPS, and compared with laboratory test data. The model incorporates the effect of the micromechanical residual stresses in the fibers and the matrix induced by the composite fabrication process. The model also incorporates the effect of discrete existing and/or progressively occurring fiber damage on global MMC deformation response. The criterion for fiber fractures is based on statistical information on fiber strength. In this work strain predictions obtained using this model are compared with thermomechanical fatigue test data.
Residual Stresses in Stainless Steel Fiber-Reinforced Aluminium Matrix Composite Plates with Central Square Hole
Authors: Akbulut H. , Senel M.
Published: July 2017

In this paper, a study on residual stresses in a stainless steel metal-fiber reinforced aluminium metal-matrix flat plate with a central square hole has been conducted. In the solution, a finite element method with two dimensional isoparametric rectangular nine node-elements has been employed. In the calculation of the residual stresses in the plate under uniform in-plane loads, Newton-Raphson method (initial stress method) has been used. After a steel-aluminium composite plate has been manufactured by upsetting under certain pressure and at certain temperture, some experiments have been carried out through the tensile testing machine in order to obtain mechanical properties and yield strength. Results show that a central hole or cut-out in a plate causes the residual stresses in a considerable quantity particularly near itself, which increases strength of the plate. It is also seen that the hole geometry and the orientation angle have affected residual stresses. Solutions are shown in graphical forms and in illustrations.
Short Banana Fiber Reinforced Polyester Composites: Mechanical, Failure and Aging Characteristics
Authors: Pothan Laly A. , Thomas Sabu , Neelakantan N. R.
Published: July 2017

This paper describes the tensile, impact, flexural properties and aging behavior of short banana fiber reinforced polyester composites with special reference to the effect of fiber length and fiber content. Maximum tensile strength was observed at 30 mm fiber length while impact strength gave the maximum value for 40 mm fiber length. Incorporation of 40% untreated fibers gave a 20% increase in the tensile strength and a 341% increase in impact strength. On treatment with silane coupling agent, composites showed a 28% increase in tensile strength and a 13% increase in flexural strength. Aging studies showed a decrease in tensile strength of the composites. The experimental tensile strength values were compared with theoretical predictions according to Piggot equation. Scanning electron microscopy studies were carried out to understand the morphology of the fiber surface, fiber pullout and interface bonding. Water absorption studies showed an increase in water uptake with increase in fiber content. Finally, the properties of banana fiber reinforced polyester composites have been compared with other natural fiber reinforced composites.
The Nature of Failure of Thick-Section Laminated Composites Containing Pre-Existing Edge Delamination
Authors: Barnes Donald A. , Vizzini Anthony J. , Macander Aleksander B.
Published: July 2017

An analytical and experimental investigation was performed to study the compression failure of thick-section laminated composites containing a pre-existing semicircular edge delamination. A three-dimensional linear finite element model was developed to predict the stress field acting along the delamination front for a laminate of arbitrary thickness and stacking sequence, and a semi-circular edge delamination of arbitrary location and size. Experimentally, thick-section E-glass fabric/vinylester laminated composite specimens containing either a single or multiple simulated semi-circular edge delamination(s) were tested in compression and in four-point bending loading conditions to ascertain the dominant failure mode. In specimens containing only a single simulated edge delamination, experimental results have shown that the failure mode depends on the depth of the initial delamination. The failure mode changed from in-plane (shear-dominated) fracture to sublaminate buckling with the consequence of delamination growth as the depth of the initial delamination decreased. However, in the specimen containing multiple simulated edge delaminations, delamination growth occurred without sublaminate buckling, possibly indicating that multiple delaminations have a larger effect on the stress state than a single delamination does.
Outcome Following Nonoperative Treatment of Brachial Plexus Birth Injuries
Authors: DiTaranto Patricia , Campagna Liliana , Price Andrew E. , Grossman John A. I.
Published: July 2017

Ninety-one infants who sustained a brachial plexus birth injury were treated with only physical and occupational therapy. The children were evaluated at 3-month intervals and followed for a minimum of 2 years. Sixty-three children with an upper or upper-middle plexus injury recovered good to excellent shoulder and hand function. In all of these children, critical marker muscles recovered M4 by 6 months of age. Twelve infants sustained a global palsy, with critical marker muscles remaining at M0—M1 at 6 months, resulting in a useless extremity. Sixteen infants with upper and upper-middle plexus injuries failed to recover greater than M1—M2 deltoid and biceps by 6 months, resulting in a very poor final outcome. These data provide useful guidelines for selection of infants for surgical reconstruction to improve ultimate outcome. ( J Child Neurol 2004; 19: 87—90).
Radial and Tangential Neuronal Migration Disorder in Ibotenate-Induced Cortical Lesions in Hamsters: Immunohistochemical Study of Reelin, Vimentin, and Calretinin
Authors: Takano Tomoyuki , Sawai Chihiro , Takeuchi Yoshihiro
Published: July 2017

To investigate the mechanisms of radial and tangential neuronal migration disorders, immunohistochemical expressions of reelin, vimentin, and calretinin were examined in brain lesions induced by ibotenate (an agonist of the N-methyl-D-aspartate [NMDA] complex receptor) in hamsters. Thirty-four newborn hamsters were subjected to intracerebral injections of ibotenate, and 12 animals served as the control. These hamsters were examined at 1, 2, 3, 5, and 7 days after injections. The cortical lesions observed after ibotenate injections had a strong resemblance to the following neuronal migration disorders: (1) microgyria, (2) focal subcortical heterotopia, and (3) leptomeningeal glioneuronal heterotopia. In microgyria, the radial glial fibers were sparsely distributed, but in leptomeningeal glioneuronal heterotopia, vimentin-positive fibers extended into this abnormal neural tissue. Calretinin-immunoreactive neurons and fibers were present along the lesion forming the microgyria and abnormal neuronal arrangement. Focal subcortical heterotopia also included a small number of calretinin-expressing neurons originating from the subplate neuronal population. These results imply that the neuronal migration disorders produced by ibotenate show not only the migrational arrest of neurons but also interference from the termination of the migration process. We also suggest that the heterotopic neurons constituting the focal subcortical heterotopia originate in the lateral or medial ganglionic eminence of the ventral telencephalon, probably caused by the abnormal tangential neuronal migration. ( J Child Neurol 2004;19:107—115).
Topiramate, Carbamazepine, and Valproate Monotherapy: Double-Blind Comparison in Children With Newly Diagnosed Epilepsy
Authors: Wheless James W. , Neto Walter , Wang Steven
Published: July 2017

In a novel double-blind trial, topiramate was compared with the investigator's choice of carbamazepine or valproate as first-line therapy in patients as young as 6 years of age with newly diagnosed epilepsy. Among 613 patients enrolled in the trial, 119 (19%) were children or adolescents (6—16 years of age). No differences between fixed doses of topiramate (100 and 200 mg/day) and carbamazepine (600 mg/day) or valproate (1250 mg/day) were observed in efficacy measures: time to exit, time to first seizure, and the proportion of patients who were seizure free during the last 6 months of treatment. Topiramate 100 mg/day (2.0 mg/kg/day in this study population) was associated with the fewest discontinuations owing to side effects. Based on efficacy and tolerability, the recommended target dose for topiramate as first-line therapy in children and adolescents is 100 mg/day. ( J Child Neurol 2004;19:135—141).
Elevated Pitch Perception Owing to Carbamazepine-Activating Effect on the Peripheral Auditory System: Auditory Brainstem Response Study
Authors: Wakamoto Hiroyuki , Kume Aya , Nakano Naoko
Published: July 2017

Auditory disturbance is an uncommon side effect of carbamazepine, the pathophysiologic mechanism of which has not been clearly elucidated. We performed an auditory brainstem response study in a 9-year-old boy with epilepsy who had suffered from falsely higher pitch perception immediately after the start of carbamazepine treatment. The auditory brainstem response results showed that both the peak latency of wave V and the interpeak latencies of waves I to V were significantly prolonged with 85 dB HL click stimulation and that the peak amplitudes of the waves were noticeably elevated, particularly with lower click stimulation intensity. Although it has been shown that carbamazepine has a suppressive effect on the central nervous system, these auditory brainstem response findings might constitute evidence of a carbamazepine-activating effect on the peripheral auditory system, which probably increased the sensitivity to low-pitched sounds, causing the development of falsely higher pitch perception in our patient. ( J Child Neurol 2004; 19:453-455).
The myelotoxicity of chloramphenicol: in vitro and in vivo studies: II: in vivo myelotoxicity in the B6C3F mouse
Authors: Holt D E , Andrews C M , Payne J P , Williams T C , Turton J A
Published: July 2017

1 Chloramphenicol continues to be widely used in many parts of the world despite its known haematotoxicity. Until now, elucidation of the mechanisms involved and any attempt at amelioration of the toxic effects have been hampered by the lack of an animal model.

2 In this study neither acute nor chronic administration of chloramphenicol as its succinate ester in the drinking water produced anaemia in mice as assessed by changes in peripheral blood parameters.

3 Chloramphenicol could not be detected in the bone marrow when the antibiotic was administered either in the drinking water or by gavage, although it was detected in the serum.

4 In marrow taken from mice after chloramphenicol succinate administration and cultured in vitro, depression of the differentiation of immature committed erythroid progenitors occurred 15 min after administration of the antibiotic by gavage. However, recovery was beginning to occur at 48 h after administration of chloramphenicol succinate at 50 and 200 mg/kg and this was then followed by an `overshoot' response at the higher dose. A toxic effect was therefore achieved in the bone marrow but this was probably masked in the peripheral blood by enhanced proliferation.

5 Morphological evidence of apoptosis was seen in erythroid and myeloid precursors in mice treated with 200 mg/kg.

6 The data suggest that the effect of chloramphenicol was at the differentiation stage of the committed marrow progenitor cells rather than at the replication stage of the stem cells and therefore this response appears to mimic the reversible bone marrow depression seen in the treated patient.
Reliability of Drug Users' Self-Reported HIV Risk Behaviors and Validity of Self-Reported Recent Drug Use
Authors: Dowling-Guyer Seana , Johnson Mark E. , Fisher Dennis G. , Needle Richard , Watters John , Andersen Marcia , Williams Mark , Kotranski Lynne , Booth Robert , Rhodes Fen , Weatherby Norman , Estrada Antonio L. , Fleming David , Deren Sherry , Tortu Stephanie
Published: July 2017

This study examined the reliability and validity of the Risk Behavior Assessment, a structured interview questionnaire designed to evaluate drug use and sexual HIV risk behaviors. Participants were 218 drug users currently not in treatment who completed the RBA two times over a 48-hour period and gave urine samples on both occasions. We examined internal consistency and test-retest reliability and found that, overall, drug users reliably report drug use and sexual behavior, although the reliability of reports of specific needle practice and sexual behavior items was somewhat lower. Validity results indicated that drug users' accurately report use of cocaine and opiates. These findings indicate that this self-report questionnaire, when administered by trained interviewers, reliably measures HIV risk behaviors in a drug-using population and provides a valid assessment of recent drug use.
Design and Realtime Implementation of an Adaptive Variation Absorber for Uncertain Mechanical Systems Subjected to Unknown Disturbances
Authors: Derkhorenian Raffi , Jalili Nader , Dawson D M
Published: July 2017

In this paper we describe the design and implementation of a nonlinear adaptive disturbance rejection approach for single-input-single-output linear-time-invariant uncertain systems subject to sinusoidal disturbances with unknown amplitude and frequency. This is an extension of our earlier study to a more complicated plant, a two-degrees-of-freedom (2DOF) system representing a vibration absorber setting. The controller design is based on a single Lyapunov function incorporating both the error states and the update laws and, hence, global stability and improved transient performance are readily achieved. Utilizing only the system output, a virtual control input is used in place of non-measurable and unknown signals. The performance of the adaptation algorithm is demonstrated through real-time simulations, both for regulation and tracking, on a 2DOF system representing an active vibration absorber setup. It is shown that when the primary system is subjected to an unknown sinusoidal disturbance, the proposed controller in the absorber subsection completely suppresses the primary system vibration in the presence of unknown disturbance.
Moving-Loads-Induced Instability in Stepped Tubes
Authors: Aldraihem Osama J , Baz Amr M
Published: July 2017

In this paper we investigate the dynamic stability and response of stepped tubes subjected to a stream of moving objects. The equations of motion for the transverse vibrations of the tube are developed using a Hamilton's principle that accounts for the out-release energy of the moving objects. The Hsu theory is used to predict the stability of the tube when subjected to periodic parametric excitations. The accuracy of the result is verified by obtaining the stability boundaries of simply supported tubes and comparing the results with the results reported in the literature. Stability maps are then obtained for clamped-free uniform tubes as well as clamped-free stepped tubes. The stability maps demonstrate that increasing the number of moving objects can deteriorate the stability characteristics of the tube. It is found that the stability of certain tube modes can be improved by providing the tube with appropriately spaced steps. It is shown that better stability characteristics can be achieved by using piezoelectric actuators. To give clear insight into the tube behavior, the dynamic response is presented for clamped-free tubes. The dynamic analyses of tubes with periodic piezoelectric and viscoelastic steps are the natural extension of the present work.
The Impact of Collisions on the Ability to Detect Rare Mutant Alleles Using Barcode-Type Next-Generation Sequencing Techniques
Authors: Canzoniero Jenna VanLiere , Cravero Karen , Park Ben Ho
Published: July 2017

Barcoding techniques are used to reduce error from next-generation sequencing, with applications ranging from understanding tumor subclone populations to detecting circulating tumor DNA. Collisions occur when more than one sample molecule is tagged by the same unique identifier (UID) and can result in failure to detect very-low-frequency mutations and error in estimating mutation frequency. Here, we created computer models of barcoding technique, with and without amplification bias introduced by the UID, and analyzed the effect of collisions for a range of mutant allele frequencies (1e−6 to 0.2), number of sample molecules (10 000 to 1e7), and number of UIDs (410-414). Inability to detect rare mutant alleles occurred in 0% to 100% of simulations, depending on collisions and number of mutant molecules. Collisions also introduced error in estimating mutant allele frequency resulting in underestimation of minor allele frequency. Incorporating an understanding of the effect of collisions into experimental design can allow for optimization of the number of sample molecules and number of UIDs to minimize the negative impact on rare mutant detection and mutant frequency estimation.
Cost-Effectiveness Analyses: A Basic Overview for Dermatologists
Authors: Chen Suephy C.
Published: July 2017

Background:

In the current age of limited health care resources, cost-effectiveness analyses are important since they provide information that can be used by decisionmakers for prioritizing and setting health care policies.

Objective:

This article gives a conceptual overview of cost-effectiveness analyses (CEAs) by discussing their strengths and limitations, introducing the calculations and variables involved, and outlining the issues in interpreting CEAs using dermatological examples.

Conclusion:

Cost-effectiveness analyses are important tools that dermatologists can use to compare medical interventions using costs, effectiveness, and health outcomes.
Pyoderma Vegetans
Authors: Papadopoulos Anthony J. , Schwartz Robert A. , Kapila Rajendra , Samady Joseph A. , Ruszczak Zbigniew , Rao Babar K. , Lambert W. Clark
Published: July 2017

Background:

Pyoderma vegetans is a rare condition that is clinically characterized by large verrucous plaques with elevated borders and multiple pustules. The etiology of this disorder remains unknown.

Objectives:

We describe a 24-year-old woman with rapidly evolving pyoderma vegetans. Our patient had the unique additional findings of a highly elevated serum IgE level and a history of hidradenitis suppurativa.

Conclusions:

Pyoderma vegetans is diagnosed on clinical and histological criteria. Differentiation must be made from disorders such as pyoderma gangrenosum, Sweet's syndrome, and deep fungal infections. We illustrate a case of pyoderma vegetans and review the literature on this rare disorder. Clinical and histological criteria for diagnosis are presented, as well as differentiation from some mimicking disorders.
Dermatological Manifestations of Down's Syndrome
Authors: Barankin Benjamin , Guenther Lyn
Published: July 2017

Background:

Down's syndrome (DS) is an extensively researched congenital condition characterized by mental retardation and distinct physical features. The cutaneous manifestations of DS are numerous, yet they seldom receive appropriate attention.

Objective:

To review the dermatological conditions associated with DS.

Methods:

A review of the medical literature.

Results:

DS is associated with an increased incidence of numerous dermatological conditions, some of which may be related to an immunological deficiency.

Conclusion:

Along with the importance of understanding the physical and psychosocial aspects of DS, an appreciation of the dermatological manifestations of this condition is integral to comprehensive medical care.
Betamethasone Valerate in Foam Vehicle is Effective with Both Daily and Twice a Day Dosing: A Single-Blind, Open-Label Study in the Treatment of Scalp Psoriasis
Authors: Feldman Steven R. , Ravis Scott M. , Fleischer Alan B. , McMichael Amy , Jones Evelyn , Kaplan Robert , Shavin Joel , Weiss Jonathan , Bartruff J. Kent , Levin Donald L. , Del Rosso James , Kpea Nomate
Published: July 2017

Background:

Psoriasis is a chronic relapsing skin disorder that affects about 2% of the U.S. population and involves the scalp approximately 50% of the time. Topical corticosteroids, including betamethasone valerate, have been used effectively in the treatment of corticosteroid-responsive dermatoses of the skin and scalp. Betamethasone valerate (BMV) in foam vehicle (Luxiq) is designed to improve patient compliance with topical therapy. Superior efficacy over a BMV lotion preparation has been demonstrated with twice-daily use. Even greater compliance would be expected if the drug is effective with once-daily application.

Purpose:

To compare the efficacy of the betamethasone valerate foam (Luxiq) in the treatment of scalp psoriasis following once-daily versus twice-daily dosing.

Methods:

Seventy-nine patients with moderate to severe scalp psoriasis from seven centers were enrolled and treated with BMV foam either once a day or twice a day for four weeks. The physician-grader was blinded to the treatment regimen, and the subjects were randomly assigned to either once-daily or twice-daily dosing in a 1:1 ratio.

Results:

The signs of psoriasis (plaque thickness, scaling, and erythema) were assessed before and after treatment. The investigator's and the patients' global assessments were also evaluated. The composite score improved from 7.7±2.1 to 3.0±2.2 with twice-a-day use and from 8.1 ± 2.2 to 3.9 ± 2.8 with once-daily use ( p > 0.05 for the difference between groups).

Discussion:

BMV foam is effective for scalp psoriasis with both once-a-day and twice-a-day use. This feature of the BMV foam is encouraging for expected improvement in clinical use.
Pseudoporphyria: An Atypical Variant Resembling Toxic Epidermal Necrolysis
Authors: Papadopoulos Anthony J. , Schwartz Robert A. , Fekete Zoltan , Kihiczak George , Samady Joseph A. , Atkin Suzanne H. , Lambert W. Clark
Published: July 2017

Background:

Pseudoporphyria has been attributed to both medication usage and chronic hemodialysis. Histologically, it is identical to porphyria cutanea tarda. It is most commonly seen as localized bullae on sun-exposed skin, often on the dorsum of the hands and fingers.

Objectives:

We describe a 31-year-old man with rapidly evolving bullae which became denuded, clinically suggestive of toxic epidermal necrolysis. Pseudoporphyria was proven histologically. However, our patient's eruption was not localized as small bullae but was widespread, with large bullae evolving into large, cutaneous, denuded erosions.

Conclusions:

We describe a previously unreported, generalized variant of pseudoporphyria that resembles toxic epidermal necrolysis. We provide a review of pseudoporphyria and compare our variant to toxic epidermal necrolysis and mimicking disorders.
Self-Healing Congenital Langerhans Cell Histiocytosis Presenting as Neonatal Papulovesicular Eruption
Authors: Morgan Kelli W. , Callen Jeffrey P.
Published: July 2017

Background:

Congenital self-healing Langerhans cell histiocytosis (CSHLCH) is a rare condition which may present at birth or during the neonatal period. It is usually characterized by the eruption of multiple, disseminated, red-brown papules and nodules which may increase in size and number during the first few weeks of life. Systemic signs are usually absent except for occasional mild hepatomegaly.

Objective:

We present a 3.5-kg male infant who presented at birth with numerous diffuse, erythematous, crusted erosions. He was presumed to have congenital herpes simplex virus (HSV) and was started on IV acyclovir. Histopathologic examination revealed a mixed inflammatory infiltrate with numerous histiocytes which were S-100 and peanut agglutin positive consistent with CSHLCH. Further workup did not reveal any signs of systemic involvement.

Conclusion:

CSHLCH has rarely been reported to present as a papulovesicular eruption at birth. In these cases, a viral etiology is commonly entertained in the differential diagnosis. Despite the spontaneous regression of skin lesions in CSHLCH, close followup is required to evaluate for systemic signs and symptoms associated with latent Letterer–Siwe disease.
Peripheral T Cell Lymphoma Presenting as Dermatomyositis-like Eruption
Authors: Rencic Adrienne , Laman Susan , Nousari Hossein C.
Published: July 2017

Background:

There are several conditions reported to mimic the cutaneous manifestations of dermatomyositis, including lymphoproliferative disorders.

Objective:

This case report presents an unusual case of peripheral T cell lymphoma mimicking dermatomyositis and discusses the clinical and pathologic features that distinguish it from dermatomyositis.

Methods and Results:

A 62-year-old woman presented with a two-month history of a progressive painful cutaneous eruption and interstitial infiltrates on chest x-ray. Skin biopsy revealed peripheral T cell lymphoma. The diagnosis was confirmed by lung biopsy.

Conclusions:

Although rare, a lymphoproliferative disorder must be included in the differential diagnosis of a cutaneous dermatomyositis-like eruption.
Progression of Cutaneous B-Cell Pseudolymphoma to Cutaneous B-Cell Lymphoma
Authors: Kulow Brittain F. , Cualing Hernani , Steele Paul , VanHorn Judi , Breneman John C. , Mutasim Diya F. , Breneman Debra L.
Published: July 2017

Background:

Debates regarding nosology and clonality surround the entity known as cutaneous pseudolymphoma and its questionable transformation to frank cutaneous lymphoma. The relevance of these arguments is important, not only from a diagnostic standpoint, but also for making inferences based upon behavior, prognosis, and treatment.

Objective:

Our goal was to demonstrate further evidence of progression from cutaneous pseudolymphoma to malignant lymphoma while at the same time advocating a comprehensive plan for evaluation, treatment, and followup of these patients.

Methods:

A retrospective review was conducted of four patients initially considered to have cutaneous B-cell pseudolymphoma (CBPL) and who were later treated for primary cutaneous B-cell lymphoma (CBCL). A review of the literature of cases suggesting progression to malignant lymphoma from precursor lesions was also performed.

Results:

Four patients initially diagnosed with CBPL by a combination of histologic, immunophenotypic, and gene rearrangement criteria had a progressive clinical course that, over a range of 17–51 months, evolved into CBCL. All patients had a comprehensive systemic workup to rule out the possibility of extracutaneous disease and were treated with local radiation therapy and close followup. There has been no evidence of extracutaneous disease with an average followup of 14 months.

Conclusion:

The potential for certain cutaneous pseudolymphomas to progress to CBCL is real. The combination of histologic and immunophenotypic criteria, along with the clinical picture, remains the best way to judge the aggressiveness of the lesion. Gene rearrangement studies, whether performed by Southern blot or polymerase chain reaction (PCR), are of limited value and should be used to support the overall clinicopathologic picture. Radiation therapy of these patients should be thought of early in the management plan and is a very successful form of treatment when combined with close followup.
6-Thioguanine in the Treatment of Psoriasis: A Case Report and Literature Review
Authors: Sherer Daniel W. , Lebwohl Mark G.
Published: July 2017

Background:

6-Thioguanine is a purine analog primarily indicated for acute myelogenous leukemia. Its use in psoriasis was first investigated in the 1950s and current interest in serious treatments for psoriasis, such as cyclosporine, has renewed interest in this medication. Newer therapies, such as PUVA and retinoids, have side effects as do some older treatments, such as methotrexate, which fell into favor at the same time 6-thioguanine was being investigated. Reexamining older treatments can open up new therapeutic options in difficult cases.

Objective:

The goal of this article is to provide a comprehensive review of the literature regarding the use of 6-thioguanine in the treatment of psoriasis as well as an illustrative case report demonstrating the use and side effects of 6-thioguanine in a patient with pustular psoriasis. Topics reviewed include efficacy, side effects, laboratory monitoring, different dosing regimens, and proposed mechanisms of action.

Conclusions:

6-Thioguanine has been highly effective in treating and maintaining improvement in patients with psoriasis. A study comparing efficacies with methotrexate would be extremely useful. Because of the possibility of severe bone marrow depression, 6-thioguanine is not a first-line treatment. However, with new dosing regimens, proper laboratory monitoring, and further studies, use of 6-Thioguanine could expand in the future.
Use of Transcutaneous Nerve Stimulation Wristband to Treat Methotrexate-Induced Nausea
Authors: Wilson Jill K. , Phelps Kathy C. , Feldman Steven R.
Published: July 2017

Background:

Although methotrexate is a highly effective treatment for psoriasis, nausea and vomiting may be dose-limiting side effects. Various approaches have been used to improve the tolerability of methotrexate therapy, including changing the dose or form of administration of the methotrexate or concomitant administration of folic acid or an antiemetic.

Objective:

The objective of this case report is to present the use of a novel, nonpharmacologic approach for controlling the nausea associated with methotrexate therapy.

Results:

A 47-year-old patient with long-standing psoriasis was treated with methotrexate. She developed nausea refractory to standard antiemetic measures. She noted almost immediate relief of her nausea when using a transcutaneous nerve stimulation wristband.

Conclusions:

Nerve stimulation may be a valid alternative to other first-line antiemetic therapies.
Modulation of the Contact Hypersensitivity Response by Æ-941 (Neovastat), a Novel Antiangiogenic Agent
Authors: Dupont É. , Wang B. , Mamelak A. J. , Howell B. G. , Shivji G. , Zhuang L. , Dimitriadou V. , Falardeau P. , Sauder D. N.
Published: July 2017

Background:

Æ-941 (Neovastat) is an angiogenesis inhibitor noted to have antiinflammatory properties.

Objective:

We tested Neovastat in a contact hypersensitivity (CHS) model to determine the mechanism of action of its antiinflammatory effects.

Methods:

Neovastat was orally administered (200 mg/kg/day) during the sensitization and challenge phases of a murine CHS assay and inflammatory responses were measured. Subsequent assays were performed on mice treated with Neovastat or Cortisone (120 mg/kg/day, IP) and differential mRNA expression of several pro- and antiinflammatory cytokines was quantified using RT-PCR.

Results:

Neovastat decreased inflammation by 39% when administered during sensitization but did not alter the CHS response when given during the challenge phase. Neovastat significantly induced IL-10 expression in skin and skin-draining lymph nodes (49% and 45%, respectively) and decreased IFNγ expression in the lymph nodes (35%).

Conclusion:

Antiinflammatory effects of Neovastat observed in CHS could be linked to modulation of cytokines early in the sensitization phase.
Role of Extracellular Adenosine Triphosphate in Human Skin
Authors: Holzer Aton M. , Granstein Richard D.
Published: July 2017

Background:

The nucleotide adenosine triphosphate (ATP) has long been known to drive and participate in countless intracellular processes. Extracellular ATP and its metabolite adenosine have also been shown to exert a variety of effects on nearly every cell type in human skin. Knowledge of the sources and effects of extracellular ATP in human skin may help shape new therapies for skin injury, inflammation, and numerous other cutaneous disorders.

Objective:

The objective of this review is to introduce the reader to current knowledge regarding the sources and effects of extracellular ATP in human skin and to outline areas in which further research is necessary to clarify the nature and mechanism of these effects.

Conclusion:

Extracellular ATP seems to play a direct role in triggering skin inflammatory, regenerative, and fibrotic responses to mechanical injury, an indirect role in melanocyte proliferation and apoptosis, and a complex role in Langerhans cell-directed adaptive immunity.
Melasma: A Review
Authors: Victor Frank C. , Gelber Jeremy , Rao Babar
Published: July 2017

Objective:

To better understand melasma, a review of its etiologic factors, classification, pathogenesis, and treatment was undertaken.

Methods:

Articles discussing the above aspects of melasma were used to demonstrate what is currently known about the disease and how to treat it.

Results:

Melasma is associated with many etiologic factors, most importantly, sun exposure. It occurs in three distributions and has four reported patterns of pigmentation. Among the many differences between melasma and normal skin, melasma skin contains increased melanin, melanocytes, and melanosomes, as well as increased synthesis of tyrosinase. Its pathogenesis remains largely unknown. Treatment consists of phenolic and nonphenolic depigmenting agents, chemical peels, lasers, and dermabrasion.

Conclusion:

Melasma is a common skin disorder. Although melasma has been studied, its pathogenesis remains largely unknown and its treatment is still met with difficulty. Randomized controlled trials involving larger numbers of patients and comparing treatments, as well as studying combination therapies, would be beneficial.
Multiple Keratoacanthomas Arising Post-UVB Therapy
Authors: Craddock Kenneth J. , Rao Jaggi , Lauzon Gilles J. , Tron Victor A.
Published: July 2017

Background:

Ultraviolet (UV) radiation is known to be an important etiologic agent in the development of skin cancer. Keratoacanthoma is an unusual, well-described cutaneous neoplasm that resembes squamous cell carcinoma but spontaneously resolves. Rarely, multiple keratoacanthomas may develop. Objective We present a case of multiple keratoacanthomas in a patient with psoriasis who had received UVB phototherapy. These lesions were hyperkeratotic papules, many of which spontaneously resolved and demonstrated the histologic characteristics of keratoacanthoma.

Conclusion:

We believe that UV radiation is the most likely etiologic factor in this patient's development of multiple keratoacanthomas. We wish to bring to the attention of clinicians this unusual adverse effect of UV treatment.
Alefacept is Well Tolerated in Patients with Chronic Plaque Psoriasis
Authors: Gottlieb Alice B.
Published: July 2017

Traditional systemic treatments for moderate to severe chronic plaque psoriasis are often poorly tolerated and are associated with safety concerns that restrict their long-term use. Alefacept is a fully human fusion protein that selectively targets memory T cells, and it is expected to provide enhanced safety over traditional nonselective agents. The safety and tolerability profile of alefacept is reviewed using data from the clinical development program. The most common adverse events were similar among alefacept and placebo groups. As expected from its mechanism of action, alefacept reduced the number of CD4+ and CD8+ T cells, with selectivity for the memory subsets. This reduction was not associated with an increase in the incidence of infections. Alefacept was not immunogenic. Patients have received up to six courses of alefacept therapy and the safety and tolerability profile over multiple courses is similar to that of a single course. Alefacept offers hope for a safer means to provide long-term management of psoriasis.
The Effect of Psoriasis on Patients' Quality of Life and Improvements Associated with Alefacept Therapy
Authors: Menter Alan
Published: July 2017

Patients with psoriasis may experience impaired psychosocial mental status regardless of their objectively defined disease severity. The objective clinical measures of disease that are commonly used to evaluate a patient's psoriasis fail to take into account the effect of psoriasis on patients' quality of life (QOL). As a result, a significant number of patients are dissatisfied with conventional treatments and are searching for new options. A high unmet need for effective and safe long-term therapies that can also improve patients' QOL exists in psoriasis. Alefacept, a selective biologic agent specifically designed for the treatment of psoriasis, provides improvement in both the physical (as measured by the Psoriasis Area and Severity Index) and mental (as measured by the Dermatology Life Quality Index) aspects of the disease. Additionally, alefacept is extremely well tolerated, with no negative effect on QOL, and the improvement in QOL is maintained off-treatment, which is consistent with its remittive effects on the disease. Alefacept helps fulfill the needs of psoriasis patients by providing efficacy, safety, off-treatment remissions, and improvement in QOL.
Infantile Myofibromatosis
Authors: Levy Elie , Raymond Giles P.
Published: July 2017

Background:

Infantile myofibromatosis is a rare condition that usually presents in infancy.

Objective:

The purpose of this article is to report a new case of late-onset infantile myofibromatosis and to review the literature regarding similar cases.

Methods:

A Medline search was performed, and a new case is reported.

Results:

The solitary tumour presented by the 9-year-old boy is histologically proven to be compatible with the diagnosis of infantile myofibromatosis.

Conclusion:

Although infantile myofibromatosis usually presents in infancy, onset may occur in childhood.
Pharmacoeconomics for Dermatologists: An Introduction
Authors: Gupta Aditya K. , Oh Paul I. , Shear Neil H.
Published: July 2017

Background:

The budgets available for health care are becoming constrained and health care decision makers have increasingly begun to scrutinize cost along with efficacy, tolerability, and cost of the different treatment options for each disease state. In keeping with the above, there has been a marked increase in the number of pharmacoeconomic evaluations published in the medical literature, including dermatology journals.

Methods:

Comprehensive economic evaluations systematically consider the following: statement of question, defining relevant costs, perspective and time-horizon, synthesis of data on efficacy and effectiveness, and selection of the appropriate analytic type and framework. The conclusions should be tested through extensive sensitivity analyses.

Conclusions:

Economic evaluations are becoming more prevalent in the field of dermatology. A well-constructed analysis may be an aid to more rational therapeutic decision-making.
Melanocytic Nevi in Malignant Melanomas
Authors: Wasti Qasim H. , Toussaint Sonia , Kopf Alfred W. , Kamino Hideko , Provost Nathalie , Bart Robert S.
Published: July 2017

Background:

A substantial proportion of malignant melanomas arise in preexisting melanocytic nevi. However, the clinical and dermoscopic features of such combination lesions have not been well defined in the literature.

Objective:

To determine the ability to recognize in thin malignant melanomas the presence or absence of melanocytic nevi based on clinical and/or dermoscopic observations.

Methods:

Thirty malignant melanomas, less than 1 mm in Breslow thickness, were studied clinically, dermoscopically, and histologically for the presence or absence of features of a melanocytic nevus.

Results:

The ability to recognize melanocytic nevi within thin malignant melanomas was poor by clinical and dermoscopic examinations, with 30% false negatives and 23% false positives.

Conclusion:

One cannot depend on clinical and/or dermoscopic observations to rule out a melanocytic nevus within a thin malignant melanoma. Histopathologic study of a small portion of a combined melanocytic neoplasm could lead to the mistaken conclusion that the lesion is entirely a melanocytic nevus or entirely a malignant melanoma. Therefore, when feasible, lesions suspected of being malignant melanomas should be totally excised and step-sectioned throughout.
Assessing Scientific Data: The Case-Control Study as it Applies to Dermatology Part 2: Interpreting the Results
Authors: Heacock Helen J. , Rivers Jason K.
Published: July 2017

Background:

In order to interpret the results of case-control studies correctly and to assign causality to an exposure-disease association, one must be able to assess elements in the design and/or analysis that may lead to inaccurate conclusions.

Objective:

The purpose of this article is to describe factors that may invalidate the results of a case-control study. Topics discussed include bias, confounding, and chance. Criteria used to judge causality between exposure and disease are highlighted. A brief checklist that can be used as a tool in the design and interpretation of case-control studies is provided.

Conclusion:

Before one concludes that an exposure causes a disease, alternative explanations for the observations must be considered. Assuming that these threats to the validity of the study have been minimized, criteria for judging causality can be examined. In this way, it becomes possible to link a specific exposure with a specific outcome.
Monitoring Isotretinoin Therapy in Acne: Rational Use of Laboratory Tests
Authors: Willoughby Joanne S. , Rosenthal Donald
Published: July 2017

Background:

Several recent long-term follow-up studies confirm the relative safety of isotretinoin in acne. Yet, conscientious dermatologists may order more laboratory tests than is strictly necessary.

Objective:

Our goals were to determine which laboratory tests used in monitoring isotretinoin therapy predict significant abnormalities, when such abnormalities are likely to occur, and to establish guidelines for practitioners in ordering these tests.

Methods:

In the Hamilton, Ontario region, 27 dermatologists were surveyed to determine the tests and their frequency requested by practicing dermatologists. We also critically reviewed the literature to establish the frequency and magnitude of laboratory tests in acne patients on isotretinoin and assessed the rationale and cost-effectiveness of the suggested tests.

Results:

Seventeen dermatologists (63%) responded. A wide range of tests were ordered at variable intervals. The literature review suggests that adverse laboratory events are uncommon and that many are clinically insignificant.

Conclusion:

Dermatologists may be requesting more laboratory tests for monitoring isotretinoin therapy than are warranted or cost-effective. We propose a rational laboratory program for monitoring patients on isotretinoin.
Calciphylaxis: A Cause of Necrotic Ulcers in Renal Failure
Authors: Kalaaji Amer N. , Douglass Margaret C. , Chaffins Marsha , Lowe Lori
Published: July 2017

Background:

Calciphylaxis is a rare and life-threatening condition occurring in patients with end-stage renal disease on dialysis. The diagnosis is frequently delayed or missed and therapy is often unsuccessful.

Objective:

The clinical and pathological components of calciphylaxis are emphasized in a patient that may facilitate early diagnosis and initiation of therapy.

Results:

Early recognition of the clinical signs and symptoms of calciphylaxis is crucial. The tissue diagnosis requires large elliptical biopsies because histological findings are segmental and often missed.

Conclusion:

Early diagnosis and intervention in calciphylaxis is critical. Parathyroidectomy should be considered in all cases.
Giant Chondroid Syringoma of the Axilla
Authors: Hardisson David , Linares Maria D. , Nistal Manuel
Published: July 2017

Background:

Chondroid syringomas are benign uncommon tumours of controversial histogenesis that most often affect the head and neck region and usually measure > 3 cm in greatest dimension.

Objective:

To describe the clinical features, histology, and differential diagnosis of an unsually large axillary chondroid syringoma.

Methods:

A 64-year-old man presented with a painless, subcutaneous tumour measuring 8 × 7 × 6.5 cm on his right axilla, which had been growing slowly for several years. The tumour was completely excised under local anesthesia. No recurrence of the tumour has been observed 12 months after surgery.

Results:

Histological examination showed cords, nests, and tubuloglandular structures composed of well-differentiated tumour cells embedded in a hyalinized stroma with abundant chondroid matrix, and the diagnosis of chondroid syringoma was established. No features suggesting malignancy were observed.

Conclusion:

As this case shows, chondroid syringoma may reach a large size, and it should be included in the differential diagnosis of slowly growing solid nodules in the skin or subcutis.
Ultraviolet Radiation-Induced p53 Responses in the Epidermis are Differentiation-Dependent
Authors: Tron Victor A. , Li Gang , Ho Vincent , Trotter Martin J.
Published: July 2017

Background:

The tumour suppressor, p53, is recognized as a crucial molecule in regulating cellular responses to various DNA-damaging agents. Very early on in the development of nonmelanoma cancers p53 is mutated or lost, suggesting that p53 is crucial in protecting normal keratinocytes from the harmful effects of ultraviolet (UV) radiation.

Objective:

Using two mouse models, one with multiple copies of mutant p53 and the other a p53 “knockout,” our laboratory has examined a role for p53 in UV-induced DNA damage and determined if these effects are differentiation dependent.

Conclusion:

We outline in this review a proposed model reflecting differentiation-dependent p53 regulation of UV-induced responses in keratinocytes. After exposure to UV, basal keratinocytes repair damaged DNA, whereas differentiating keratinocytes undergo cell death, both processes are regulated by p53.
African Television and Training
Authors: Lewenhak H. K.
Published: July 2017

‘The public disappointment at the performance of television still continues. Broadcasting personnel are rarely well trained.’ UN Economic Commission for Africa, Addis Ababa, 1979.