Scratching the Surface: A Review of Dermatitis.

GENERAL PURPOSE: To present a case-based review illustrating atopic and contact dermatitis, including management of these conditions using topical and systemic therapies. TARGET AUDIENCE: This continuing education activity is intended for physicians, physician assistants, nurse practitioners, and nurses with an interest in skin and wound care. LEARNING OBJECTIVES/OUTCOMES: After participating in this educational activity, the participant should be better able to:1. Review the prevalence, etiology, and consequences of the various types of dermatitis.2. Describe the clinical manifestations and differential diagnosis of the various types of dermatitis.3. Outline the treatment options for the various types of dermatitis. ABSTRACT: Eczematous reactions such as atopic dermatitis and contact dermatitis are prevalent worldwide. Despite contrasting pathophysiology, the diagnosis and management of these dermatitides can be challenging for healthcare providers. Differences in the distribution of the affected areas, duration of onset, and associated symptoms may help to distinguish these conditions. Diagnosis of the respective conditions is useful in developing appropriate management plans. Herein, the authors present a case-based review illustrating these different disease entities. Management of these conditions, including the use of topical and systemic therapies, is discussed.

Diagnosis and Management of Cutaneous Tinea Infections.

GENERAL PURPOSE: To provide information about the epidemiology, clinical features, and management of cutaneous tinea infections. TARGET AUDIENCE: This continuing education activity is intended for physicians, physician assistants, nurse practitioners, and nurses with an interest in skin and wound care. LEARNING OBJECTIVES/OUTCOMES: After completing this continuing education activity, you should be better able to:1. Summarize the epidemiology related to cutaneous tinea infections.2. Describe the clinical features of cutaneous tinea infections.3. Identify features related to the diagnosis and management of cutaneous tinea infections. ABSTRACT: Dermatophyte or tinea infection refers to a group of superficial fungal infections of the hair, skin, and nails. Tinea infections are most commonly caused by fungi of the genus Trichophyton, Microsporum, or Epidermophyton. Cutaneous manifestations of tinea infections are seen worldwide and classified based on the affected body site. The diagnosis of these conditions is complicated by morphologic variations in presentation and overlap with other common infectious and noninfectious entities. As a result, diagnosis and appropriate management of these conditions are essential to avoid patient morbidity. This case-based review summarizes the epidemiology, relevant clinical features, microbiology, and management considerations for commonly encountered tinea infections.

Extending ζ-factor microanalysis to boron-rich ceramics: Quantification of bulk stoichiometry and grain boundary composition.

Accurate quantification of light elements which produce only soft X-ray lines via X-ray energy dispersive spectrometry (XEDS) has been traditionally difficult due to poor X-ray emission and detector efficiencies at low energies and significant X-ray absorption effects. The ζ-factor microanalysis method enables one to correct for these shortcomings; however, ζ-factor microanalysis has not yet been thoroughly applied to inorganic materials which are entirely or mostly composed of light elements such as boron carbide, boron nitride, or boron suboxide. This work successfully extended ζ-factor microanalysis to boron-rich ceramics and accurately determined stoichiometries of multiple boron carbides and measured grain boundary compositions of a boron carbide mixed with additives consisting of rare-earth ions. Various strategies were employed to experimentally determine a full range of ζ-factors and measurements were validated using materials of known composition including silicon hexaboride and silicon carbide. Overall, this work has shown that XEDS is a viable technique for light element quantification in (scanning) transmission electron microscopy, in terms of both the accuracy and precision, which is comparable or superior to the complementary electron energy loss spectrometry.

Finasteride for androgenetic alopecia is not associated with sexual dysfunction: a survey-based, single-centre, controlled study.

BACKGROUND: The occurrence of sexual dysfunction side-effects associated with finasteride use in men with androgenetic alopecia (AGA) is thought to be less prevalent than is publicized. There is a need to investigate sexual dysfunction among finasteride users with population-based controls. OBJECTIVE: To evaluate the presence of sexual dysfunction in men using finasteride or not using finasteride. METHOD: Adult men visiting a dermatologist's office for any reason were asked to complete a survey including a modified version of the Arizona Sexual Experience Scale (ASEX) to assess the presence of sexual dysfunction with and without finasteride use. RESULTS: Data from 762 men aged 18-82 were collected: 663 finasteride users and 99 non-finasteride users. There were no significant differences between finasteride users and non-user controls in reporting sexual dysfunction using the ASEX. Regression analysis indicated that self-reporting libido loss and reduced sexual performance, not finasteride use, predict a higher ASEX score. CONCLUSION: The use of finasteride does not result in sexual dysfunction in men with AGA. These data are consistent with other large survey-based controlled studies.

[Apparent worsening of psoriasis lesions revealing methotrexate overdosage]. / Aggravation apparente d'un psoriasis révélant un surdosage en méthotrexate.

BACKGROUND: Methotrexate (MTX) is an antimetabolite drug used in the treatment of cancers and autoimmune diseases and frequently in dermatology for cutaneous and/or arthritic psoriasis. Toxicities due to MTX overdosage are mainly cutaneous, hepatic and hematologic. Herein, we report a case of MTX overdosage presenting as an erosive and an inflammatory flare of preexisting psoriatic plaques and with new palmar lesions. PATIENTS AND METHODS: A 51-year-old male with a 6-year history of plaque psoriasis resistant to topical corticosteroids was started for the first time on MTX 20mg weekly. One week later, he presented with fever, general weakness and mucocutaneous ulcerations. Physical examination revealed inflammatory, erythematous and partially erosive annular plaques strictly confined to preexisting psoriatic lesions, along with keratotic psoriatic palmar plaques. Further questioning indicated that the patient was taking MTX 20mg daily. Investigations revealed neutropenia (1040/mm3) and skin histology showed prominent dystrophic keratinocytes and confirmed the diagnosis of methotrexate toxicity. Clinical and biological improvements were observed after cessation of MTX and treatment with folinic acid, IV hydration and urine alkalization. DISCUSSION: Skin lesions due to acute MTX toxicity are rare, but they herald later-onset pancytopenia. Identification of these cutaneous lesions might enable earlier treatment initiation. The predilection of MTX toxicity for preexisting lesions or the de novo appearance of palmoplantar pustules should not lead to the erroneous diagnosis of psoriasis flare.

Pole-placement Predictive Functional Control for under-damped systems with real numbers algebra.

This paper presents the new algorithm of PP-PFC (Pole-placement Predictive Functional Control) for stable, linear under-damped higher-order processes. It is shown that while conventional PFC aims to get first-order exponential behavior, this is not always straightforward with significant under-damped modes and hence a pole-placement PFC algorithm is proposed which can be tuned more precisely to achieve the desired dynamics, but exploits complex number algebra and linear combinations in order to deliver guarantees of stability and performance. Nevertheless, practical implementation is easier by avoiding complex number algebra and hence a modified formulation of the PP-PFC algorithm is also presented which utilises just real numbers while retaining the key attributes of simple algebra, coding and tuning. The potential advantages are demonstrated with numerical examples and real-time control of a laboratory plant.

[Fabry disease]. / Maladie de Fabry.

Fabry disease, also known as Anderson-Fabry disease or angiokeratoma corporis diffusum universale, is an X-linked recessive form of sphingolipidosis caused by total or partial deficiency of the lysosomal hydrolase, alpha-galactosidase A. From the youngest age, it results in a gradual ubiquitous build-up of glycosphingolipids that are not degraded by the missing enzyme. Cutaneous, neurological, nephrologic, cardiac, gastrointestinal, ophthalmological, respiratory, cochleovestibular and haematological involvement are responsible for increased mortality and significant impairment of quality of life in subjects affected by the disease. Angiokeratomas are the most common cutaneous sign of this disease, although they are not specific to it and must be distinguished from angiokeratomas either occurring in isolation or associated with systemic diseases. Other cutaneous signs encountered in this disease include hyperhidrosis, oral lesions, lower limb oedemas, etc. The diagnosis is mainly clinical and should be considered in the presence of a personal and/or familial history; it is confirmed by assay of enzyme activity within leucocytes or by molecular studies. Management is multidisciplinary and involves symptomatic treatment as well as specific treatment, resulting in improved survival and enhanced quality of life for patients presenting the disease. Enzyme replacement therapy with alpha-galactosidase A forms the cornerstone of specific treatment and may be associated with other types of treatments such as galactose and molecular chaperones. Gene therapy is now also used extensively. At present, these marked therapeutic advances, which closely involve dermatologists, could help transform the prognosis for patients presenting Fabry disease.

Pole-placement Predictive Functional Control for over-damped systems with real poles.

This paper gives new insight and design proposals for Predictive Functional Control (PFC) algorithms. Common practice and indeed a requirement of PFC is to select a coincidence horizon greater than one for high-order systems and for the link between the design parameters and the desired dynamic to be weak. Here the proposal is to use parallel first-order models to form an independent prediction model and show that with these it is possible both to use a coincidence horizon of one and moreover to obtain precisely the desired closed-loop dynamics. It is shown through analysis that the use of a coincidence horizon of one greatly simplifies coding, tuning, constraint handling and implementation. The paper derives the key results for high-order and non-minimum phase processes and also demonstrates the flexibility and potential industrial utility of the proposal.

Onychomadesis: literature review.

Onychomadesis is characterized by separation of the nail plate from the matrix with persistent attachment to the nail bed and often, but not always, eventual shedding. Onychomadesis has been associated with infection, autoimmune disease, critical illness and medications. To our knowledge a literature review of all associations with onychomadesis has not been completed previously. Most commonly, onychomadesis has been reported in association with pemphigus vulgaris and hand-foot-mouth disease, and following chemotherapy or antiepileptic medications. This article summarizes these key culprit associations, postulates the pathogenesis of nail matrix arrest and summarizes the clinical outcomes. We conducted a retrospective review of cases of onychomadesis reported from January 1960 to March 2013. Using the PubMed database, the literature was searched using the following terms: 'onychomadesis' and 'proximal nail shedding'. Also, an Ovid search was carried out using the same terms. In total 56 articles have been published, including our previously reported series of idiopathic onychomadesis. Articles pertaining only to Beau's lines and not true onychomadesis were excluded. Onychomadesis has been associated with autoimmune disease, other major medical illness, neonatal illness, medication and infection.

Steady-state pleural fluid flow and pressure and the effects of lung buoyancy.

Both theoretical and experimental studies of pleural fluid dynamics and lung buoyancy during steady-state, apneic conditions are presented. The theory shows that steady-state, top-to-bottom pleural-liquid flow creates a pressure distribution that opposes lung buoyancy. These two forces may balance, permitting dynamic lung floating, but when they do not, pleural-pleural contact is required. The animal experiments examine pleural-liquid pressure distributions in response to simulated reduced gravity, achieved by lung inflation with perfluorocarbon liquid as compared to air. The resulting decrease in lung buoyancy modifies the force balance in the pleural fluid, which is reflected in its vertical pressure gradient. The data and model show that the decrease in buoyancy with perfluorocarbon inflation causes the vertical pressure gradient to approach hydrostatic. In the microgravity analogue, the pleural pressures would be toward a more uniform distribution, consistent with ventilation studies during space flight. The pleural liquid turnover predicted by the model is computed and found to be comparable to experimental values from the literature. The model provides the flow field, which can be used to develop a full transport theory for molecular and cellular constituents that are found in pleural fluid.

Learning oral presentation skills: a rhetorical analysis with pedagogical and professional implications.

OBJECTIVE: Oral presentation skills are central to physician-physician communication; however, little is known about how these skills are learned. Rhetoric is a social science which studies communication in terms of context and explores the action of language on knowledge, attitudes, and values. It has not previously been applied to medical discourse. We used rhetorical principles to qualitatively study how students learn oral presentation skills and what professional values are communicated in this process. DESIGN: Descriptive study. SETTING: Inpatient general medicine service in a university-affiliated public hospital. PARTICIPANTS: Twelve third-year medical students during their internal medicine clerkship and 14 teachers. MEASUREMENTS: One-hundred sixty hours of ethnographic observation. including 73 oral presentations on rounds. Discoursed-based interviews of 8 students and 10 teachers. Data were qualitatively analyzed to uncover recurrent patterns of communication. MAIN RESULTS: Students and teachers had different perceptions of the purpose of oral presentation, and this was reflected in performance. Students described and conducted the presentation as a rule-based, data-storage activity governed by "order" and "structure." Teachers approached the presentation as a flexible means of "communication" and a method for "constructing" the details of a case into a diagnostic or therapeutic plan. Although most teachers viewed oral presentations rhetorically (sensitive to context), most feedback that students received was implicit and acontextual, with little guidance provided for determining relevant content. This led to dysfunctional generalizations by students, sometimes resulting in worse communication skills (e.g., comment "be brief" resulted in reading faster rather than editing) and unintended value acquisition (e.g., request for less social history interpreted as social history never relevant). CONCLUSIONS: Students learn oral presentation by trial and error rather than through teaching of an explicit rhetorical model. This may delay development of effective communication skills and result in acquisition of unintended professional values. Teaching and learning of oral presentation skills may be improved by emphasizing that context determines content and by making explicit the tacit rules of presentation.

Thyroid cytology and the risk of malignancy in thyroid nodules: importance of nuclear atypia in indeterminate specimens.

Fine needle aspiration (FNA) cytology is the best test for malignancy in thyroid nodules. However, cytologic interpretation of FNA specimens is often difficult, especially in the presence of indeterminate microfollicular cytologic patterns, which are thought to suggest follicular neoplasm (adenoma or carcinoma). To assess the risk of malignancy associated with specific cytologic patterns, we correlated preoperative FNA cytologic patterns (n = 484 reports including repeat aspirations) with final histological diagnoses for 368 surgical thyroid specimens obtained during the period 1994-1998. The overall prevalence of malignancy in the surgical specimens was 31% (113 cancers, including 96 papillary and 9 follicular carcinomas). For nodules with benign FNA cytologic diagnoses of nodular goiter and chronic thyroiditis there was a low risk of malignancy (6/99, or 6.1%). Nodules with indeterminate cytologic patterns in the absence of nuclear atypia (i.e., microfollicles without nuclear atypia) had a similarly low malignancy risk (3/46, or 6.5%). In contrast, 31/52 nodules with cytologic nuclear atypia consistent with follicular neoplasm were malignant (60%), including specimens with or without microfollicular cytology. Nodules with frankly malignant cytologic patterns were almost invariably cancer (54/55), and cytologic diagnoses of papillary carcinoma were confirmed at surgery in all 49 cases. These results indicate that indeterminate microfollicular cytologic patterns in the absence of nuclear atypia are associated with a low risk of malignancy, at least in this series. This finding suggests that many nodules with such microfollicular cytology might be managed conservatively with observation. In contrast, cytologic nuclear atypia consistent with a follicular neoplasm confers a high risk of cancer. In addition, frankly malignant cytologic diagnoses, especially papillary carcinoma, are highly reliable, and thus may be used as a guide for planning surgery appropriate for thyroid cancer.

The independence of size perception and distance perception.

Research on distance perception has focused on environmental sources of information, which have been well documented; in contrast, size perception research has focused on familiarity or has relied on distance information. An analysis of these two parallel bodies of work reveals their lack of equivalence. Furthermore, definitions of familiarity need environmental grounding, specifically concerning the amount of size variation among different tokens of an object. To demonstrate the independence of size and distance perception, subjects in two experiments were asked to estimate the sizes of common objects from memory and then to estimate both the sizes and the distances of a subset of such objects displayed in front of them. The experiments found that token variation was a critical variable in the accuracy of size estimations, whether from memory or with vision, and that distance had no impact at all on size perception. Furthermore, when distance information was good, size had no effect on distance estimation; in contrast, at far distances, the distances to token variable or unknown objects were estimated with less accuracy. The results suggest that size perception has been misconceptualized, so that the relevant research to understand its properties has not been undertaken. The size-distance invariance hypothesis was shown to be inadequate for both areas of research.

Role of ultrasonography in the diagnosis and management of thyroid cancer.

OBJECTIVE: To review the role of ultrasonography in the detection and management of thyroid cancer. METHODS: Viewpoints are presented on the appropriate applications and the advantages of ultrasonography, based on an extensive personal experience with more than 1,500 ultrasound examinations for assessment of thyroid nodules and for follow-up surveillance of patients with thyroid cancer. RESULTS: Ultrasonography is ideal for thyroid imaging because of the high echogenicity of thyroid tissue, the superficial site of the thyroid that allows the use of high-frequency transducers yielding high resolution, and the low expense compared with other techniques. In patients with a thyroid nodule, ultrasonography can assist in distinguishing benign from malignant disease. Ultrasound studies will characterize the presence of cystic versus solid elements, the degree of echogenicity of solid elements, the existence of calcifications, and the regularity and definition of the nodule borders. Although individual sonographic features of thyroid nodules are not specific for benign or malignant lesions, a constellation of typical features has more diagnostic value. Hypoechogenicity, poorly defined irregular margins, and microcalcifications are characteristics that should increase the index of suspicion for a malignant nodule. Cytologic examination of fine-needle aspirates is the optimal diagnostic test, and ultrasonographic guidance for performance of the aspiration biopsy is often helpful and sometimes critical. Ultrasonography is also useful for detection of cervical lymph node metastatic lesions. Lymph nodes involved with metastatic thyroid cancer tend to become rounded and bulging, and they lose their hilar echoes as their structure becomes disrupted. CONCLUSION: Because of its high resolution and relatively reasonable cost, ultrasonography is valuable in the diagnosis and management of thyroid cancer.