Theta and gamma rhythmic coding through two spike output modes in the hippocampus during spatial navigation

Hippocampal CA1 neurons generate single spikes and stereotyped bursts of spikes. However, it is unclear how individual neurons dynamically switch between these output modes and whether these two spiking outputs relay distinct information. We performed extracellular recordings in spatially navigating rats and cellular voltage imaging and optogenetics in awake mice. We found that spike bursts are preferentially linked to cellular and network theta rhythms (3-12 Hz) and encode an animal's position via theta phase precession, particularly as animals are entering a place field. In contrast, single spikes exhibit additional coupling to gamma rhythms (30-100 Hz), particularly as animals leave a place field. Biophysical modeling suggests that intracellular properties alone are sufficient to explain the observed input frequency-dependent spike coding. Thus, hippocampal neurons regulate the generation of bursts and single spikes according to frequency-specific network and intracellular dynamics, suggesting that these spiking modes perform distinct computations to support spatial behavior.

Altered Morphology and Immunohistochemical Characteristics in Metastatic Malignant Melanoma After Therapy With Vemurafenib

Metastatic melanoma is traditionally diagnosed using classic morphologic features in addition to immunohistochemical studies. The authors report a case of metastatic malignant melanoma where both morphology and immunohistochemistry were altered after treatment. This 51-year-old patient presented with metastatic melanoma to the brain and axilla. Initially, both metastases showed classic morphology and diffuse staining with the pan-melanoma antibody cocktail. This cocktail is a combination of 3 antibodies commonly used to diagnose melanocytic neoplasms: Melan-A (MART-1), tyrosinase, and HMB-45. In combination, the cocktail is highly sensitive for detecting melanocytic neoplasms and is commonly used to diagnose metastatic melanoma. Her tumor was positive for the BRAF 1799T>A (V600E) mutation, and she was treated with BRAF inhibitor therapy (vemurafenib). However, the axillary tumor recurred after treatment with vemurafenib. The recurrent tumor showed a markedly different morphology and complete loss of staining with the pan-melanoma antibody cocktail. This loss of staining accompanied by the change in morphology was an observation not previously documented after therapy with vemurafenib. This case demonstrates a potential pitfall in the diagnosis of metastatic or recurrent malignant melanoma.

The role of sirolimus in the prevention of cutaneous squamous cell carcinoma in organ transplant recipients

Skin cancers are common in organ transplant recipients (OTRs). In this review, we discuss the epidemiology of and risk factors for cutaneous neoplasms, particularly squamous cell carcinoma (SCC) in OTRs. The pathogenesis of SCC is reviewed, as well as the potential mechanisms for tumor progression and metastasis associated with two commonly used immunosuppressive medications: tacrolimus and cyclosporine. Finally, we discuss the mechanism of action and potential preventative use of sirolimus, a member of a newer class of immunosuppressants, the mammalian target of rapamycin inhibitors. The authors have indicated no significant interest with commercial supporters.

Refractory Hailey-Hailey disease successfully treated with sandpaper dermabrasion

A 53-year-old woman presented with a 20-year history of pruritic dermatitis on the groin, axillae, inframammary folds, posterior aspect of the neck, and popliteal fossae. She was referred to our clinic by an outside facility after results from a punch biopsy diagnosed Hailey-Hailey disease (HHD). The patient had previously attempted treatment with many traditional noninvasive options with no success. Topical treatment modalities included corticosteroids, immunomodulators, antifungals, retinoids, and antibiotic preparations. Intralesional corticosteroids, as well as botulinum toxin and carbon dioxide laser, were also unsuccessful. Failed systemic treatment modalities included antibiotics, antihistamines, prednisone, azathioprine, mycophenolate mofetil, acitretin, isotretinoin, adalimumab, and etanercept. Of note, cyclosporine was successful in clearing the cutaneous involvement in our patient, but elevation ofcreatinine and exacerbated hypertension precluded continued use. The decision was made to treat the patient by dermabrasion with sandpaper. The patient was prepped in a sterile fashion, and a field block with 1% lidocaine with epinephrine was performed. This was followed by abrasion down to the superficial dermis with 3M Sandblaster fine sandpaper (3M, St. Paul, MN) and hyfrecation between rounds ofdermabrasion. The treated areas were then covered with petrolatum and sterile gauze, and antibiotics and pain medication were prescribed. This treatment was initially performed on the patient's posterior aspect of the neck and later to the bilateral popliteal fossae and axillae. Three months post-treatment, desirable functional and cosmetic results of the treated areas had been achieved (Figure 1 and Figure 2). While no recurrence of clinically active HHD has been seen in the dermabraded areas of the neck and popliteal fossae, the patient continues to have active disease in the axillae despite sandpaper dermabrasion. To quantify our results, we performed two biopsies in the dermabraded sites of the popliteal fossae as healing occurred: a shave biopsy from an obviously active area, and a punch biopsy from a peripheral inactive border. The biopsy from the active area showed diffuse epidermal acantholysis similar to that seen in untreated HHD, while the healing periphery showed only scattered acantholytic areas and a sparse perivascular infiltrate-a marked improvement from the untreated areas.

Epidermolytic hyperkeratosis and congenital platelike osteoma cutis in a child

Epidermolytic hyperkeratosis is a rare congenital ichthyosis. Platelike osteoma cutis also is a rare diagnosis and is associated with abnormal ossification of cutaneous or subcutaneous tissue. A 17-month-old Hispanic girl presented with a plate of subcutaneous bone since birth as well as considerable scaling and hyperkeratosis centered around the joints. Histologic examination confirmed the diagnosis of both epidermolytic hyperkeratosis and osteoma cutis. Although there have been some cases of epidermolytic hyperkeratosis with other dermatologic conditions, we report a rare case of epidermolytic hyperkeratosis and platelike osteoma cutis.

Abnormal aquaporin-3 protein expression in hyperproliferative skin disorders

Non-melanoma skin cancers (NMSCs) and psoriasis represent common hyperproliferative skin disorders, with approximately one million new NMSC diagnoses each year in the United States alone and a psoriasis prevalence of about 2% worldwide. We recently demonstrated that the glycerol channel, aquaporin-3 (AQP3) and the enzyme phospholipase D2 (PLD2) interact functionally in epidermal keratinocytes of the skin to inhibit their proliferation. However, others have suggested that AQP3 is pro-proliferative in keratinocytes and is upregulated in the NMSC, squamous cell carcinoma (SCC). To evaluate the AQP3/PLD2 signaling module in skin diseases, we determined their levels in SCC, basal cell carcinoma (BCC) and psoriasis as compared to normal epidermis. Skin biopsies with the appropriate diagnoses (10 normal, 5 SCC, 13 BCC and 10 plaque psoriasis samples) were obtained from the pathology archives and examined by immunohistochemistry using antibodies recognizing AQP3 and PLD2. In normal epidermis AQP3, an integral membrane protein, was localized mainly to the plasma membrane and PLD2 to the cell periphery, particularly in suprabasal layers. In BCC, AQP3 and PLD2 levels were reduced as compared to the normal-appearing overlying epidermis. In SCC, AQP3 staining was "patchy," with areas of reduced AQP3 immunoreactivity exhibiting positivity for Ki67, a marker of proliferation. PLD2 staining was unchanged in SCC. In psoriasis, AQP3 staining was usually observed in the cytoplasm rather than in the membrane. Also, in the majority of psoriatic samples, PLD2 showed weak immunoreactivity or aberrant localization. These results suggest that abnormalities in the AQP3/PLD2 signaling module correlate with hyperproliferation in psoriasis and the NMSCs.

Adjunctive radiotherapy in the treatment of cutaneous squamous cell carcinoma with perineural invasion

Perineural invasion is a feature associated with significantly poorer outcomes when present in cutaneous squamous cell carcinoma (CSCC). The incidence of this subset of CSCC continues to rise in the US, as does the confusion surrounding exactly how it should be managed. While management typically involves excision, considerable debate exists as to the appropriate use of adjuvant radiotherapy (ART) in addition to excision. This article reviews the current relevant evidence for the use of ART.

Pseudolymphomatous and lichenoid reaction to a red tattoo: a case report

A pseudolymphomatous reaction is an unusual immune response that can be caused by a tattoo, most commonly by red ink. We present the case of a 40-year-old woman with discolored and pruritic plaques in the areas of red ink tattooed on her right ankle that developed shortly after tattoo application. The patient had 2 other tattoos with red ink for more than 20 years without any disfigurement. Histopathology, immunohistochemistry, and polymerase chain reaction analysis from biopsy of the affected area showed polyclonal pseudolymphomatous and lichenoid reaction, confirming the diagnosis of pseudolymphoma secondary to a tattoo. Total excision of the lesion was performed.

Lasp1 gene disruption is linked to enhanced cell migration and tumor formation

Lasp1 is an actin-binding, signaling pathway-regulated phosphoprotein that is overexpressed in several cancers. siRNA knockdown in cell lines retards cell migration, suggesting the possibility that Lasp1 upregulation influences cancer metastasis. Herein, we utilized a recently developed gene knockout model to assess the role of Lasp1 in modulating nontransformed cell functions. Wound healing and tumor initiation progressed more rapidly in Lasp1(-/-) mice compared with Lasp1(+/+) controls. Embryonic fibroblasts (MEFs) derived from Lasp1(-/-) mice also migrated more rapidly in vitro. These MEFs characteristically possessed increased focal adhesion numbers and displayed more rapid attachment compared with wild-type MEFs. Differential microarray analyses revealed alterations in message expression for proteins implicated in cell migration, adhesion, and cytoskeletal organization. Notably, the focal adhesion protein, lipoma preferred partner (LPP), a zyxin family member and putative Lasp1 binding protein, was increased about twofold. Because LPP gene disruption reduces cell migration, we hypothesize that LPP plays a role in enhancing the migratory capacity of Lasp1(-/-) MEFs, perhaps by modifying the subcellular localization of other motility-associated proteins. The striking contrast in the functional effects of loss of Lasp1 in innate cells compared with cell lines reveals distinct differences in mechanisms of motility and attachment in these models.

Transglutaminases: the missing link in nephrogenic systemic fibrosis

Nephrogenic systemic fibrosis (NSF), also known as nephrogenic fibrosing dermopathy (NFD), occurs in renal failure patients after gadolinium contrast exposure. The fibrosis of the dermis and subcutaneous septae accompanies fibrosis of other organs, including the heart, liver, lungs, and muscle. The fibrotic skin demonstrates increased dermal collagen, fibroblasts, and mucin. The mechanism by which gadolinium is associated with fibrosis is not known. We tested the hypothesis that upregulation of transglutaminases contributes to the fibrosis seen in the organs, including skin, of renal failure patients exposed to gadolinium contrast. We performed immunohistochemical studies using antibodies to transglutaminase-2, factor XIIIa, transglutaminase isopeptide, and the histiocyte marker CD68 on five archived skin biopsies of NSF. The results indicate that the dermal fibroblasts and histiocytes of NSF express transglutaminase-2, CD68, factor XIIIa, and transglutaminase isopeptide, indicating increased expression and/or activation of transglutaminases in NSF. We recommend further research into the use of transglutaminase inhibitors in the treatment and prevention of NSF.

Proliferating trichilemmal tumors: a review of the literature

BACKGROUND

Proliferating trichilemmal tumors (PTTs) are uncommon lesions whose histologic hallmark is the presence of trichilemmal keratinization. PTT is thought to originate from the trichilemmal cyst (TC) and have the potential for malignant transformation, at which point it is termed a malignant proliferating trichilemmal tumor (MPTT). These lesions may cause considerable morbidity and even mortality, and recurrence after simple local excision is common.

OBJECTIVE

The objective was to review the clinical presentation, histopathologic characteristics, malignant potential, and treatment options for PTT.

METHODS

The English literature was reviewed regarding PTT, TC, and MPTT.

RESULTS

PTT generally presents as a subepidermal tumor on the scalp in women over the age of 60. Histologic findings may be used to differentiate PTT from TC and MPTT. Complete surgical excision is recommended; additional radiotherapy and/or chemotherapy may be used for lesions with increased invasive potential.

CONCLUSION

Adequate treatment of PTT requires skilled histopathologic examination for proper diagnosis; histologic appearance may not correlate with clinical behavior. After surgical excision, long-term clinical follow-up for evidence of metastatic disease is judicious.

Paecilomyces lilacinus infection with a sporotrichoid pattern in a renal transplant patient

Paecilomyces lilacinus (P. lilacinus) is a saprophytic fungus with increasing prevalence as a source of infection in the immunosuppressed patient population. We report a P. lilacinus infection with a sporotrichoid pattern spreading in a renal transplant recipient that responded to itraconazole therapy. There was no recurrence at 3 years follow-up.

Development of anidulafungin for disk diffusion susceptibility testing against Candida spp

A disk diffusion (DD) method has been standardized by the Clinical and Laboratory Standards Institute (M44-A) to test Candida susceptibilities for some azoles (fluconazole and voriconazole). The DD method using anidulafungin, a new echinocandin, was initially developed here using Candida spp. (75 strains) and candidate anidulafungin disk concentrations of 1, 2, 5, and 10 microg with or without dimethyl sulfoxide (DMSO) (0.05-1%) and with or without polysorbate 80 (P-80, 0.002-2%). The 2-microg disks (with 1% DMSO and 0.1% P-80) produced acceptable correlation statistics (r = 0.84-0.85 ) when compared with reference MIC results, and this disk was optimal for testing all Candida spp. Good separation of Candida parapsilosis (least anidulafungin-susceptible species) from the more susceptible yeast species and a potential susceptibility breakpoint near the preferred reproducible zone diameter of > or = 15 mm were achieved for all tested yeast species.

Bactericidal activity and resistance development profiling of dalbavancin

Dalbavancin, a semisynthetic lipoglycopeptide being developed for the treatment of skin and skin structure infections (SSSIs), has a half-life of 5 to 7 days in humans and offers promise for a convenient weekly dosing regimen. We studied the in vitro bactericidal activity of dalbavancin against target organisms, using the concentrations that are maintained in human blood with the proposed dosage regimen. Dalbavancin minimal bactericidal concentrations (MBCs) were<or=0.5 microg/ml for eight staphylococcal isolates; and for six of these strains, including one vancomycin-intermediate Staphylococcus aureus (VISA) isolate, the MBCs were equal to or within 1 doubling dilution of the MIC. Dalbavancin MICs for all three Streptococcus pyogenes strains were 0.008 microg/ml, as were the MBCs for two of the isolates. In time-kill studies conducted with a different set of seven strains (two methicillin-susceptible S. aureus isolates, three methicillin-resistant S. aureus isolates, one VISA isolate, and one S. pyogenes isolate), all strains exhibited a>or=3-log10 decrease in their viable counts when they were exposed to>or=1 microg/ml of dalbavancin for 24 h. Resistance development studies by both direct selection (resistance frequency, <10(-10)) and serial passage failed to produce stable mutants with decreased susceptibility to dalbavancin. These observations suggest that dalbavancin will be an effective choice for the management of patients with SSSIs.

Activity of linezolid against 3,251 strains of uncommonly isolated gram-positive organisms: report from the SENTRY Antimicrobial Surveillance Program

Linezolid was tested against 32 species of uncommonly isolated gram-positive organisms (3,251 strains) by reference MIC methods and found to be highly active (MIC50 range, 0.25 to 2 microg/ml; MIC90 range, 0.25 to 2 microg/ml). Only one isolate (viridans group streptococcus; 0.03% of tested strains) was resistant to linezolid.

Selection of a surrogate agent (vancomycin or teicoplanin) for initial susceptibility testing of dalbavancin: results from an international antimicrobial surveillance program

The immediate lack of market-dominating commercial products (Vitek or MicroScan) for susceptibility testing of the new glycolipopeptide, dalbavancin, requires a surrogate marker agent to assist microbiologists in the correct categorization of potentially indicated species (staphylococci and streptococci). Error-rate analyses for 16,749 isolates using vancomycin or teicoplanin results to categorize dalbavancin susceptibilities demonstrated that both glycopeptide agents were highly predictive of dalbavancin-susceptible results (nearly 100%) with only a rare minor error. Vancomycin test results most reliably predict dalbavancin susceptibility until validated commercial reagents become available for direct testing in clinical practice.

Application of fluorescent probes to study structural changes in Aspergillus fumigatus exposed to amphotericin B, itraconazole, and voriconazole

The broad objective of this study was to document patterns of structural changes following antifungal treatment, and to determine any relationship with minimum inhibitory concentration (MIC) of an antifungal. Three clinical isolates of Aspergillus fumigatus, with high, intermediate, and low amphotericin B (AB), itraconazole (IZ), and voriconazole (VZ) MICs were studied in 24-well plates with cover slips. The fluorescent probes used were Calcofluor White (cell wall), propidium iodide (nucleus), and MitoTracker Green FM (mitochondria). Fluorescent microscopy as early as 3-h after exposure revealed that AB treated hyphae had intact cell wall with deformed mitochondria and nuclei while IZ and VZ treated hyphae revealed no intact cell wall, and deformation of mitochondria and nuclei. At 48 h, AB treated cells revealed rupture of hyphae and disintegration of mitochondria, and nuclei, IZ treated hyphae were swollen with disintegration of mitochondria, and nuclei while VZ treated hyphae showed rupture and disintegration of mitochondria and nuclei. The structural changes for the three strains studied were similar in fluorescent microscopy as long as the incubation time and their respective MICs were used. Thus, AB, IZ, and VZ induced gross organelle defects in A. fumigatus nuclei, mitochondria, and cell wall, which were consistent with respective MICs of antifungals used.

Video game induced knuckle pad

Controversy and concern surround the video game playing fascination of children. Scientific reports have explored the negative effects of video games on youth, with a growing number recognizing the actual physical implications of this activity. We offer another reason to discourage children's focus on video games: knuckle pads. A 13-year-old black boy presented with an asymptomatic, slightly hyperpigmented plaque over his right second distal interphalangeal joint. A punch biopsy specimen confirmed knuckle pad as the diagnosis, and a traumatic etiology from video game playing was suspected. Knuckle pads can be painful, cosmetically unappealing, and refractory to treatment. They can now be recognized as yet another potential adverse consequence of chronic video game playing.

Correlation of MIC with outcome for Candida species tested against voriconazole: analysis and proposal for interpretive breakpoints

Developing interpretive breakpoints for any given organism-drug combination requires integration of the MIC distribution, pharmacokinetic and pharmacodynamic parameters, and the relationship between the in vitro activity and outcome from both in vivo and clinical studies. Using data generated by standardized broth microdilution and disk diffusion test methods, the Antifungal Susceptibility Subcommittee of the Clinical and Laboratory Standards Institute has now proposed interpretive breakpoints for voriconazole and Candida species. The MIC distribution for voriconazole was determined using a collection of 8,702 clinical isolates. The overall MIC90 was 0.25 microg/ml and 99% of the isolates were inhibited at < or = 1 microg/ml of voriconazole. Similar results were obtained for 1,681 Candida isolates (16 species) from the phase III clinical trials. Analysis of the available data for 249 patients from six phase III voriconazole clinical trials demonstrated a statistically significant correlation (P = 0.021) between MIC and investigator end-of-treatment assessment of outcome. Consistent with parallel pharmacodynamic analyses, these data support the following MIC breakpoints for voriconazole and Candida species: susceptible (S), < or = 1 microg/ml; susceptible dose dependent (SDD), 2 microg/ml; and resistant (R), > or = 4 microg/ml. The corresponding disk test breakpoints are as follows: S, > or = 17 mm; SDD, 14 to 16 mm; and R, < or = 13 mm.

Interpretive breakpoints for fluconazole and Candida revisited: a blueprint for the future of antifungal susceptibility testing

Developing interpretive breakpoints for any given organism-drug combination requires integration of the MIC distribution, pharmacokinetic and pharmacodynamic parameters, and the relationship between in vitro activity and outcome from both in vivo and clinical studies. Previously, the Subcommittee for Antifungal Testing of the Clinical and Laboratory Standards Institute (CLSI [formerly National Committee for Clinical Laboratory Standards]) proposed MIC interpretive breakpoints for fluconazole and Candida spp. These breakpoints were considered to be somewhat weak, because the clinical data supporting them came largely from mucosal infections and there were very few infections involving strains with elevated fluconazole MICs. We readdress the issue of fluconazole breakpoints for Candida by using published clinical and microbiologic data to provide further validation of the breakpoints proposed by the CLSI in 1997. We also address interpretive breakpoints for agar disk diffusion testing of fluconazole. The MIC distribution for fluconazole was determined with a collection of 13,338 clinical isolates. The overall MIC at which 90% of the isolates were inhibited was 8 microg/ml: 91% were susceptible (S) at a MIC of or= 64 microg/ml). Similar results were obtained for 2,190 isolates from randomized clinical trials. Analysis of available data for 1,295 patient-episode-isolate events (692 represented mucosal infections and 603 represented invasive infections) from 12 published clinical studies demonstrated an overall success rate of 77%, including 85% for those episodes in which the fluconazole MIC was or= 64 microg/ml) isolates. Pharmacodynamic analysis demonstrated a strong relationship between MIC, fluconazole dose, and outcome. A dose/MIC ratio of approximately 25 was supportive of the following susceptibility breakpoints for fluconazole and Candida spp.: S, MIC or= 64 microg/ml. The corresponding disk test breakpoints are as follows: S, >or=19 mm; SDD, 15 to 18 mm; R, Collapse

Key Words Collapse

MESH Headings

• Antifungal Agents/administration & dosage
• Antifungal Agents/pharmacology
• Antifungal Agents/therapeutic use
• Candida/drug effects
• Candidiasis/drug therapy
• Clinical Trials as Topic
• Dose-Response Relationship, Drug
• Drug Resistance, Fungal
• Fluconazole/pharmacokinetics
• Fluconazole/pharmacology
• Fluconazole/therapeutic use
• Humans
• Microbial Sensitivity Tests/standards
• Treatment Outcome

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Grants Collapse

Affiliation(s)

M A Pfaller Department of Pathology, Medical Microbiology Division, C606 GH, University of Iowa College of Medicine, Iowa City, 52242, USA.
D J Diekema
D J Sheehan

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In vitro activity of linezolid against key gram-positive organisms isolated in the united states: results of the LEADER 2004 surveillance program

Since the approval of linezolid in 2000, sporadic reports of resistance have been given and a greater understanding of the underlying mechanisms of resistance has been gained. However, since these developments, an updated status of the in vitro activity of linezolid against gram-positive organisms from the United States has not been reported. The LEADER 2004 surveillance initiative was undertaken to obtain current and representative data on the activity of linezolid against key species, including isolates with significant resistance phenotypes. Organisms were isolated during 2004 and included 2,872 Staphylococcus aureus, 496 coagulase-negative staphylococcus (CNS), 428 Enterococcus faecalis, 196 Enterococcus faecium, and 422 Streptococcus pneumoniae isolates. All S. aureus isolates (54.2% oxacillin resistant) were susceptible to linezolid (MIC90 = 2 microg/ml); MIC distributions were consistent, regardless of oxacillin or multidrug resistance status. For CNS, one nonsusceptible isolate was encountered (Staphylococcus epidermidis; MIC = 32 microg/ml), but overall, the MIC(90) (1 microg/ml) was lower than that obtained with S. aureus. For E. faecalis and E. faecium, 99.5% and 96.4% of isolates, respectively, were linezolid susceptible. Both species had an MIC90 of 2 microg/ml, and MIC distributions did not vary with the vancomycin susceptibility status of the populations analyzed. Linezolid nonsusceptibility was not encountered among the S. pneumoniae isolates. These findings indicate that linezolid nonsusceptibility has remained rare among staphylococci and uncommon and sporadic among enterococci. Nonetheless, careful and ongoing monitoring of the in vitro effectiveness of linezolid will be needed so that any changes to the current status may be detected as soon as possible.

Laboratory-based surveillance of current antimicrobial resistance patterns and trends among Staphylococcus aureus: 2005 status in the United States

Background

The virulence, antimicrobial resistance, and prevalence of S. aureus underscores the need for up-to-date and extensive insights regarding antimicrobial susceptibility trends. One approach to meet this need is analysis of clinical laboratory – based surveillance data.

Methods

Data from The Surveillance Network-USA (TSN), an electronic surveillance network that collects microbiology data from 300 clinical microbiology laboratories across the United States, were used as the source for analysis that included prevalence of S. aureus in clinical specimens, MRSA and multi-drug resistance phenotype rates and trends according to patient location, geographic distributions, and specimen source.

Results

S. aureus was the most prevalent species isolated from inpatient specimens (18.7% of all bacterial isolates) and the second most prevalent (14.7%) from outpatient specimens. In March 2005 MRSA rates were 59.2%, 55%, and 47.9% for strains from non-ICU inpatients, ICU, and outpatients, respectively. This trend was noted in all nine US Bureau of Census regions and multi-drug resistance phenotypes (resistance to ≥ 3 non-beta-lactams) was common among both inpatient MRSA (59.9%) and outpatient MRSA (40.8%). Greater than 90% of multi-drug resistant MRSA were susceptible to trimethoprim-sulfamethoxazole, linezolid, and vancomycin.

Conclusion

Prevalence of MRSA among both inpatient and outpatient specimens continues to increase with multi-drug resistance as a common phenotype. Continued emergence of outpatient MRSA that exhibit multi-drug resistant phenotypes has important implications for developing and evolving outpatient treatment guidelines.

The Effect of Sunless Tanning on Behavior in the Sun: A Pilot Study

BACKGROUND

In the United States, indoor tanning is a booming industry and contributes to the ultraviolet light (UVL) burden that ultimately leads to skin cancer. "Sunless" tanning methods that avoid UVL exposure may represent a safe alternative. However, the effects of sunless tanning methods on ultraviolet light-related behaviors have never been investigated.

METHODS

Anonymous survey of 121 individuals who underwent a spray-on sunless tanning treatment between February and May 2004.

RESULTS

Women completed 107 surveys. Men completed 14 surveys. The majority of individuals reported that they had not or would not change their time spent outdoors or their sunscreen use as a result of undergoing sunless tanning. However, 73% of individuals who had used UVL tanning beds said they had decreased or would decrease their UVL tanning bed use.

CONCLUSION

Sunless tanning is associated with a self-reported decrease in traditional UVL tanning bed use among tanning bed users. Physicians should advocate the use of sunless tanning to their patients who use traditional UVL tanning beds as a means of decreasing their UVL exposure and cancer risk.

Cutaneous draining sinus tract of odontogenic origin: unusual presentation of a challenging diagnosis

A 44-year-old woman presented with a chronically draining lesion on her cheek just lateral to the nasofacial sulcus. The lesion was refractory to treatment with oral antibiotics. Physical examination revealed poor dentition, and a panoramic radiograph demonstrated periapical abscesses in the maxillary right lateral incisor and canine. A diagnosis of cutaneous fistula of odontogenic origin was made, and the patient was treated with tooth extraction. The cutaneous fistula subsequently resolved. Intraoral examinations and radiographs are critical for making the diagnosis of cutaneous draining sinus tract of odontogenic origin. Many patients undergo unnecessary surgical therapies before having the correct diagnosis made, but root canal therapy or surgical extraction is the treatment of choice. A dental origin must be considered for any chronically draining sinus of the face or neck.

Combination treatment of invasive fungal infections

The persistence of high morbidity and mortality from systemic fungal infections despite the availability of novel antifungals points to the need for effective treatment strategies. Treatment of invasive fungal infections is often hampered by drug toxicity, tolerability, and specificity issues, and added complications often arise due to the lack of diagnostic tests and to treatment complexities. Combination therapy has been suggested as a possible approach to improve treatment outcome. In this article, we undertake a historical review of studies of combination therapy and also focus on recent studies involving newly approved antifungal agents. The limitations surrounding antifungal combinations include nonuniform interpretation criteria, inability to predict the likelihood of clinical success, strain variability, and variations in pharmacodynamic/pharmacokinetic properties of antifungals used in combination. The issue of antagonism between polyenes and azoles is beginning to be addressed, but data regarding other drug combinations are not adequate for us to draw definite conclusions. However, recent data have identified potentially useful combinations. Standardization of assay methods and adoption of common interpretive criteria are essential to avoid discrepancies between different in vitro studies. Larger clinical trials are needed to assess whether combination therapy improves survival and treatment outcome in the most seriously debilitated patients afflicted with life-threatening fungal infections.

Atrophic dermatofibrosarcoma protuberans: a case report and reappraisal of the literature

Dermatofibrosarcoma protuberans (DFSP) is an uncommon cutaneous malignancy. Unusual presentations described as atrophic have been documented. A case of DFSP with both clinical and histologic atrophy is presented, and all cases purporting atrophy with this tumor are reviewed. Meaningful trends are extracted from this data. In addition, the imprecise use of the term atrophic in regard to DFSP is clarified. We maintain that the variant of atrophic DFSP that mimics atrophoderma or anetoderma, as in this case, is the rarest variant of atrophic DFSP. Atrophic DFSP should be in the differential for depressed lesions on the trunks of women or on the lower extremities of children.

Determination of fungicidal activities against yeasts and molds: lessons learned from bactericidal testing and the need for standardization

In certain unique clinical settings, the ability of the antimicrobial agent administered to kill the pathogen outright may be quite important. These situations invariably involve infection of a site not easily accessed by host defenses and/or of a structure with essential anatomic or physiologic function such as the heart (endocarditis), central nervous system (meningitis), or bone (osteomyelitis). Likewise, infections in immunosuppressed hosts, especially those who are neutropenic, are often thought to require microbicidal therapy. Proof of the cidal nature of an antimicrobial agent in vitro is tedious, complex, and fraught with error. Although several methods for assessing in vitro bactericidal activity have been standardized (NCCLS M26-A and M21-A), the clinical relevance of these determinations is questionable and the tests are performed infrequently in most laboratories. Most of the clinical data supporting the need for microbicidal therapy and testing have focused on bacterial infections. However, given the fact that most serious fungal infections occur in profoundly immunosuppressed individuals, it is generally assumed that a cidal regimen would be preferable in that setting as well. In view of this clinical concern and the perceived need to assess the fungicidal activity of a variety of agents, we considered that it would be useful to review what is known about the issues and problems in assessing bactericidal activity and the clinical utility of such measurements. Following this review, we discuss the issue of how one defines fungicidal activity in vitro and in vivo and how feasible it might be to determine the fungicidal activity of organism-drug combinations for purposes of both drug development and clinical care. Proposed methods for fungal time-kill determinations and minimal fungicidal concentration determinations are also discussed.

Deep venous thrombosis after high-dose intravenous immunoglobulin in the treatment of pemphigus vulgaris

A 43-year-old black man with pemphigus vulgaris was started on intravenous immunoglobulin (IVIg) therapy after his disease was found to be refractorry to prednisone alone and prednisone in combination with mycophenolate mofetil, azathioprine, methotrexate, cyclosporine, and oral cyclophosphamide. The patient subsequently developed a deep venous thrombosis (DVT) that was attributed to the IVIg. IVIg has been associated with numerous thrombotic complications such as pulmonary embolism and myocardial infarction. Traditional risk factors for thrombotic complications, such as hypertension, a history of coronary artery disease, and immobility, should be considered as relative contraindications to IVIg therapy.

Pyogenic granuloma arising within a port-wine stain

Pyogenic granulomas are common overgrowths of vascular tissue that usually arise on the face, lips, or hands after episodes of minor trauma or during pregnancy. Pyogenic granulomas rarely have been reported to arise in congenital capillary malformations such as port-wine stains, a presentation that most often occurs after laser treatment of port-wine stains or in the setting of pregnancy. This co-occurrence of the 2 lesions represents an underreported event, and the presentation can be alarming or mimic malignancy when there is no prior history of trauma or other known circumstances in which pyogenic granulomas occur. We report a case of a pyogenic granuloma emerging within a port-wine stain in a 35-year-old man with no predisposing factors. A review of the literature regarding pyogenic granulomas that arise within port-wine stains is presented and yields informative conclusions regarding the clinical scenarios where this sometimes alarming event is likely to happen.

In vitro antifungal activities of voriconazole and reference agents as determined by NCCLS methods: review of the literature

Voriconazole (VfendTM) is a new triazole that currently is undergoing phase III clinical trials. This review summarizes the published data obtained by NCCLS methods on the in vitro antifungal activity of voriconazole in comparison to itraconazole, amphotericin B, fluconazole, ketoconazole and flucytosine. Voriconazole had fungistatic activity against most yeasts and yeastlike species (minimum inhibitory concentrations [MICs] < 2 microg/ml) that was similar or superior to those of fluconazole, amphotericin B, and itraconazole. Against Candida glabrata and C. krusei, voriconazole MIC ranges were 0.03 to 8 and 0.01 to > 4 microg/ml, respectively. For four of the six Aspergillus spp. evaluated, voriconazole MICs (< 0.03 to 2 microg/ml) were lower than amphotericin B (0.25 to 4 microg/ml) and similar to itraconazole MICs. Voriconazole fungistatic activity against Fusarium spp. has been variable. Against E oxysporum and F. solani, most studies showed MICs ranging from 0.25 to 8 microg/ml. Voriconazole had excellent fungistatic activity against five of the six species of dimorphic fungi evaluated (MIC90s < 1.0 microg/ml). The exception was Sporothrix schenckii (MIC90s and geometric mean MICs > or = 8 microg/ml). Only amphotericin B had good fungistatic activity against the Zygomycetes species (voriconazole MICs ranged from 2 to > 32 microg/ml). Voriconazole showed excellent in vitro activity (MICs < 0.03 to 1.0 microg/ml) against most of the 50 species of dematiaceous fungi tested, but the activity of all the agents was poor against most isolates of Scedosporium prolificans and Phaeoacremonium parasiticum (Phialophora parasitica). Voriconazole had fungicidal activity against most Aspergillus spp., B. dermatitidis, and some dematiaceous fungi. In vitro/in vivo correlations should aid in the interpretation of these results.

Antifungal susceptibility testing: practical aspects and current challenges

Development of standardized antifungal susceptibility testing methods has been the focus of intensive research for the last 15 years. Reference methods for yeasts (NCCLS M27-A) and molds (M38-P) are now available. The development of these methods provides researchers not only with standardized methods for testing but also with an understanding of the variables that affect interlaboratory reproducibility. With this knowledge, we have now moved into the phase of (i) demonstrating the clinical value (or lack thereof) of standardized methods, (ii) developing modifications to these reference methods that address specific problems, and (iii) developing reliable commercial test kits. Clinically relevant testing is now available for selected fungi and drugs: Candida spp. against fluconazole, itraconazole, flucytosine, and (perhaps) amphotericin B; Cryptococcus neoformans against (perhaps) fluconazole and amphotericin B; and Aspergillus spp. against (perhaps) itraconazole. Expanding the range of useful testing procedures is the current focus of research in this area.