Primary cutaneous SMARCA4-deficient undifferentiated malignant neoplasm: A rare case report and literature review

Primary cutaneous SMARCA4-deficient undifferentiated malignant neoplasm (SD-UMN) is a rare and recently described entity characterized by the loss of expression of the SMARCA4 (BRG1) protein, which is involved in chromatin remodeling. SD-UMN presents a diagnostic challenge due to its rarity and unique histopathological and immunohistochemical features. In this report, we present a case of primary cutaneous SD-UMN in a 67-year-old man who presented with a rapidly growing, ulcerated, and bleeding nodule on his right cheek. Histopathological examination revealed a highly cellular dermal tumor consisting of pleomorphic epithelioid cells with prominent mitotic figures and necrosis, lacking any morphological evidence of differentiation. Immunohistochemical analysis showed a complete loss of SMARCA4 and SMARCA2 expression, while INI-1 expression remained intact. p53 was diffusely expressed, and p16 was completely absent. In addition, a range of markers, including high-molecular-weight cytokeratin, p63, SOX10, INSM1, MCPyV, NKX2.2, CD99, CDX2, CD56, ERG, NUT, desmin, androgen receptor, chromogranin, CD34, and CD43 were all negative. To date, only two cases of primary cutaneous SMARCA4-deficient undifferentiated tumors have been reported in the literature. Therefore, this case report adds to the limited body of knowledge on the clinical and histopathological features of this novel entity. The report highlights the importance of considering SD-UMN in the differential diagnosis of undifferentiated cutaneous tumors.

Safety, pharmacokinetics and neutralization of the broadly neutralizing HIV-1 human monoclonal antibody VRC01 in healthy adults

VRC-HIVMAB060-00-AB (VRC01) is a broadly neutralizing HIV-1 monoclonal antibody (mAb) isolated from the B cells of an HIV-infected patient. It is directed against the HIV-1 CD4 binding site and is capable of potently neutralizing the majority of diverse HIV-1 strains. This Phase I dose-escalation study in healthy adults was conducted at the National Institutes of Health (NIH) Clinical Center (Bethesda, MD, USA). Primary objectives were the safety, tolerability and pharmacokinetics (PK) of VRC01 intravenous (i.v.) infusion at 5, 20 or 40 mg/kg, given either once (20 mg/kg) or twice 28 days apart (all doses), and of subcutaneous (s.c.) delivery at 5 mg/kg compared to s.c. placebo given twice, 28 days apart. Cumulatively, 28 subjects received 43 VRC01 and nine received placebo administrations. There were no serious adverse events or dose-limiting toxicities. Mean 28-day serum trough concentrations after the first infusion were 35 and 57 μg/ml for groups infused with 20 mg/kg (n = 8) and 40 mg/kg (n = 5) doses, respectively. Mean 28-day trough concentrations after the second infusion were 56 and 89 μg/ml for the same two doses. Over the 5-40 mg/kg i.v. dose range (n = 18), the clearance was 0.016 l/h and terminal half-life was 15 days. After infusion VRC01 retained expected neutralizing activity in serum, and anti-VRC01 antibody responses were not detected. The human monoclonal antibody (mAb) VRC01 was well tolerated when delivered i.v. or s.c. The mAb demonstrated expected half-life and pharmacokinetics for a human immunoglobulin G. The safety and PK results support and inform VRC01 dosing schedules for planning HIV-1 prevention efficacy studies.

A replication defective recombinant Ad5 vaccine expressing Ebola virus GP is safe and immunogenic in healthy adults

Ebola virus causes irregular outbreaks of severe hemorrhagic fever in equatorial Africa. Case mortality remains high; there is no effective treatment and outbreaks are sporadic and unpredictable. Studies of Ebola virus vaccine platforms in non-human primates have established that the induction of protective immunity is possible and safety and human immunogenicity has been demonstrated in a previous Phase I clinical trial of a 1st generation Ebola DNA vaccine. We now report the safety and immunogenicity of a recombinant adenovirus serotype 5 (rAd5) vaccine encoding the envelope glycoprotein (GP) from the Zaire and Sudan Ebola virus species, in a randomized, placebo-controlled, double-blinded, dose escalation, Phase I human study. Thirty-one healthy adults received vaccine at 2×10(9) (n=12), or 2×10(10) (n=11) viral particles or placebo (n=8) as an intramuscular injection. Antibody responses were assessed by ELISA and neutralizing assays; and T cell responses were assessed by ELISpot and intracellular cytokine staining assays. This recombinant Ebola virus vaccine was safe and subjects developed antigen specific humoral and cellular immune responses.

A flow cytometry-based assay to assess RSV-specific neutralizing antibody is reproducible, efficient and accurate

Respiratory syncytial virus (RSV) is an important cause of respiratory infection in people of all ages, and is the leading cause of hospitalization in infants. Although commercially available monoclonal antibody is available for passive prophylaxis of neonates at risk of severe disease, there is no available vaccine to prevent RSV. Measurement of neutralizing activity will be a key endpoint for vaccine evaluation. Assessment of neutralizing antibody against RSV has been limited to traditional plaque reduction, which is time-consuming and inherently operator dependent and highly variable. Here, we describe a flow cytometry-based RSV-specific neutralization assay which is more rapid than traditional methods, highly sensitive and highly reproducible.

Human respiratory syncytial virus reduces the number of cells in S-phase and increases GADD153 expression in HEp-2 cells

Human respiratory syncytial virus (HRSV) associated with bronchiolitis and asthma is known to replicate actively in ciliated epithelial cells. However, little is known about the influence of HRSV replication on the cell cycle. We found that HRSV infection of HEp-2 cells led to a reduction of the number of cells in S-phase, to an increase in the number of cells in G1-phase, together with an increase of GADD153 mRNA levels and GADD153 protein expression. These results implied that a shorter S-phase supported HRSV replication suggesting possible strategies for interfering with productive HRSV infection.

Vaccine development in the twenty-first century: changing paradigms for elusive viruses

Vaccine development and licensure for new viral diseases is a complex enterprise. In the past, pathogenic viruses might have been simply attenuated or inactivated to generate an effective vaccine. Such vaccines had an enormous impact on the spread of common viral diseases and have resulted in extraordinary improvements in personal and public health. However, as the frequency of epidemic disease has receded, public tolerance for adverse effects has diminished. Today, the perceived risk‐to‐benefit ratio for an individual must be lower than ever if a new vaccine is to be acceptable to the public. Even when objective data indicate that adverse events are rare and efficacy is nearly 100%, some vaccines have been anecdotally linked to prevalent disease conditions in popular opinion, creating a perception of harm and evading scientific rebuttal.

Clinical Pharmacology & Therapeutics (2009); 86 3, 234–236. doi:10.1038/clpt.2009.128

Folliculitis decalvans treated with radiation therapy

A 33-year-old black man presented with folliculitis decalvans resistant to multiple oral and topical therapies. The patient ultimately responded to radiation therapy.

Eruptive syringomas: an unusual presentation on the buttocks

Syringomas are benign, eccrine, sweat gland tumors. Eruptive syrin-gomas are rare variants that typically develop on the body's anterior surface. We present the case of a 21-year-old black man with multiple, eruptive, asymptomatic syringomas on his buttocks that had persisted for 3 months. This case is unusual in that the patient's age, race, and sex and the location of the lesions are not considered typical for eruptive syringomas. We also present a review of eruptive syringomas and recent literature.

Exogenous and Endogenous Cutaneous Anomalies and Curiosities

Exogenous and endogenous substances can produce some interesting cutaneous abnormalities. Exogenous lesions are externally introduced materials or foreign bodies. Endogenous lesions are substances that result from tissue host response to an injury or physical insult. There may be an overlap of these endogenous and exogenous lesions such that externally introduced materials can lead to peculiar tissue reactions. Pathologists should be aware of these anomalies as many of them can simulate neoplasms (ie, Monsel's reaction, polyvinylpyrrolidone disease, silica reaction) and inflammatory (ie, paraffinoma) and infectious processes (ie, Drysol(R) reaction and Lycopodium granuloma). The most interesting and important entities within each of these categories are presented with essential clinical and pathologic descriptions.

Cobb syndrome associated with a verrucous (angiokeratomalike) vascular malformation

Cobb syndrome is defined by a cutaneous vascular lesion and a corresponding spinal cord vascular malformation within a segment or two of the involved dermatome. Even though Cobb syndrome has been reported in association with various cutaneous vascular lesions, to our knowledge, only one other previous report describes verrucous changes overlying the cutaneous vascular lesion. We describe a patient with verrucous vascular malformation extending from his right chest to his right upper back in a dermatomal distribution. The patient's medical history included excision of a cavernous vascular malformation from the corresponding segment of his thoracic spinal cord 4 years prior, reversing 7 years of progressive leg weakness and neural deficits. Cobb syndrome was diagnosed based on the dermatomally distributed vascular malformation and the corresponding spinal cord vascular malformation. His skin lesions initially improved with erbium: YAG laser treatment but later recurred. This is the second reported case of Cobb syndrome associated with verrucous angiokeratomalike changes overlying the cutaneous vascular malformation. Because of the potentially severe neurologic sequelae caused by spinal cord lesions, clinicians should evaluate patients with dermatomally distributed cutaneous lesions on the trunk or extremities, including vascular malformations with verrucous features.

Reiter's syndrome

Reiter's syndrome is a multisystem disease commonly triggered by a genitourinary infection or bacterial enteric infection. After a short latent period, ocular symptoms, oligoarthritis, and mucocutaneous involvement may occur. Classic cutaneous manifestations of Reiter's syndrome include keratoderma blennorrhagicum and balanitis circinata, both of which are microscopically similar to pustular psoriasis.

Embryonal rhabdomyosarcoma presenting in an adult: a case report and discussion of immunohistochemical staining

Embryonal rhabdomyosarcoma is the most common soft tissue sarcoma of childhood but is rarely seen in adults. We report an embryonal rhabdomyosarcoma of the cheek in a 21-year-old Filipino man presenting as a rapidly enlarging mass. An incisional biopsy was consistent with embryonal rhabdomyosarcoma. The patient failed to respond to one cycle of chemotherapy after initial diagnosis and workup for metastatic disease. Wide local excision of the tumor was then completed with the use of the Mohs technique to clear the glabrous cutaneous margins during surgery. A Mohs surgeon and dermatopathologist were involved in interpretation of the Mohs sections. Subsequent immunohistochemical staining revealed a poorly differentiated spindled and epithelioid cell tumor, which stained diffusely positive for vimentin, S-100, and MyoD1. Rare rhabdomyoblasts were present and stained positively for desmin, muscle-specific actin, and phosphotungstic acid hematoxylin. The patient subsequently underwent radiation therapy for a total of 6,000 cGy, followed by two cycles of chemotherapy. The patient continues to be disease-free at 22 months after his wide local excision.

Chondroid syringoma

We present the case of a 25-year-old man who presented with a slowly enlarging nodule on the upper lip. This nodule first appeared after minor trauma to the area. Our original differential diagnosis included foreign body granuloma, mucocele, inclusion cyst, and adnexal tumor. Histopathology results showed an encapsulated tumor consisting of 2 discrete lobules composed of numerous aggregates of cuboid epithelial cells with tubuloalveolar structures and keratinous cysts within a chondroid stroma-consistent with a chondroid syringoma. We compare and contrast the clinical and histologic characteristics of chondroid syringomas (arising from sweat glands) with those of pleomorphic adenomas (arising from salivary glands).

Acne treatment with a 1,450 nm wavelength laser and cryogen spray cooling

BACKGROUND AND OBJECTIVES

A laser with a wavelength in the mid-IR range targeting the depth in skin where sebaceous glands are located in combination with cryogen spray cooling was evaluated for treatment of acne. In this non-ablative treatment, the laser energy heats the dermal volume encompassing sebaceous glands whereas the cold cryogen spray preserves the epidermis from thermal damage.

STUDY DESIGN/MATERIALS AND METHODS

Monte Carlo simulations and heat transfer calculations were performed to optimize the heating and cooling parameters. A variety of heating and cooling parameters were tested in an in vivo rabbit ear study to evaluate the histological effect of the device on sebaceous glands and skin. Similar experiments were performed on ex vivo human skin. A clinical study for the treatment of acne on backs of human males was also conducted.

RESULTS

Monte Carlo simulations and heat transfer calculations resulted in a thermal damage profile that showed epidermal preservation and peak damage in the upper dermis where sebaceous glands are located. Ex vivo human skin histology confirmed the damage profile qualitatively. In vivo rabbit ear histology studies indicated short-term thermal alteration of sebaceous glands with epidermal preservation. In the human clinical study on the back, a statistically significant reduction in lesion count on the treated side compared to the control side was seen (p < 0.001). Side effects were transient and few.

CONCLUSIONS

The studies reported here demonstrate the feasibility of treating acne using a photothermal approach with a mid-IR laser and cryogen cooling.

Congenital tufted angioma

A 7-year-old Filipino girl presented to the dermatology clinic with a slowly enlarging plaque on the inner aspect of her upper left arm. Although she had this lesion since birth, it had gradually enlarged and become indurated and slightly painful. The histopathologic examination showed a vascular proliferation within the dermis, with a "cannonball" appearance consistent with a tufted angioma. We review the literature and discuss the clinical presentation of this rare vascular tumor.

Suppression of airway hyperresponsiveness induced by ovalbumin sensitisation and RSV infection with Y-27632, a Rho kinase inhibitor

BACKGROUND

Smooth muscle contraction is one of the hallmarks of asthma. A recently developed pyridine derivative, Y-27632, a selective Rho kinase inhibitor, has been reported to inhibit the smooth muscle contraction of human and animal trachea in ex vivo systems but its effect in animal models of airway hyperresponsiveness (AHR) has not been examined. The purpose of this study was to evaluate the effect of Y-27632 in a murine model of allergic and virally induced AHR.

METHODS

Baseline lung resistance and methacholine induced AHR were measured in mice sensitised to ovalbumin (OVA) and also in mice infected with respiratory syncytial virus (RSV) following ovalbumin sensitisation (OVA/RSV).

RESULTS

Time course and dose ranging experiments indicated that 30 mg/kg Y-27632 given by gavage 2 hours before methacholine challenge significantly reduced baseline lung resistance and prevented AHR in OVA sensitised mice. Y-27632 also suppressed AHR induced by the bronchospastic agent serotonin in OVA sensitised mice and prevented methacholine induced AHR in OVA/RSV mice.

CONCLUSIONS

These results suggest that the signalling pathway mediated through Rho kinase may have an important role in bronchial smooth muscle tone in allergen induced and virus induced AHR and should be considered as a novel target for asthma treatment.

Immune interaction between respiratory syncytial virus infection and allergen sensitization critically depends on timing of challenges

Severe respiratory syncytial virus (RSV) infection has been hypothesized to be a risk factor for the development of allergy and asthma, but epidemiologic studies in humans have been inconclusive. By use of a well-characterized murine model of RSV infection and allergic sensitization with ovalbumin, the effect of a preceding severe RSV infection on the development of the pulmonary allergic inflammatory response and airway hyperresponsiveness (AHR) was tested. The impact of prior allergic sensitization on RSV-induced illness, as measured by weight loss, also was evaluated. RSV infection before allergic sensitization decreased allergen-induced AHR, production of interleukin-13 in lung tissue, and lung eosinophilia. In contrast, allergic sensitization before RSV infection increased AHR and decreased RSV-related weight loss and lung levels of interferon-gamma but did not alter viral clearance. These data provide evidence that RSV-associated AHR occurs in hosts with allergic responses and that allergic inflammation is diminished when preceded by RSV infection.

Alternative mechanisms of respiratory syncytial virus clearance in perforin knockout mice lead to enhanced disease

Virus-specific cytotoxic T lymphocytes are key effectors for the clearance of virus-infected cells and are required for the normal clearance of respiratory syncytial virus (RSV) in mice. Although perforin/granzyme-mediated lysis of infected cells is thought to be the major molecular mechanism used by CD8(+) cytotoxic T lymphocytes for elimination of virus, its role in RSV has not been reported. Here, we show that viral clearance in perforin knockout (PKO) mice is slightly delayed but that both PKO and wild-type mice clear virus by day 10, suggesting an alternative mechanism of RSV clearance. Effector T cells from the lungs of both groups of mice were shown to lyse Fas (CD95)-overexpressing target cells in greater numbers than target cells expressing low levels of Fas, suggesting that Fas ligand (CD95L)-mediated target cell lysis was occurring in vivo. This cell lysis was associated with a delay in RSV-induced disease in PKO mice compared to the time of disease onset for wild-type controls, which correlated with increased and prolonged production of gamma interferon and tumor necrosis factor alpha levels in PKO mice. We conclude that while perforin is not necessary for the clearance of primary RSV infection, the use of alternative CTL target cell killing mechanisms is less efficient and can lead to enhanced disease.

RhoA is activated during respiratory syncytial virus infection

Respiratory syncytial virus (RSV) is an important human pathogen that can cause severe and life-threatening respiratory infections in infants and immunocompromised adults. We have recently shown the RSV F glycoprotein, which mediates viral fusion and entry, interacts with the cellular protein RhoA in two-hybrid and in vitro binding assays. Whether this interaction occurs in living cells remains an open question. However, because RhoA signaling is associated with many cellular functions relevant to RSV pathogenesis such as actin cytoskeleton organization, expression of proinflammatory cytokines, and smooth muscle contraction, we asked whether RhoA activation occurred during RSV infection of HEp-2 cells. We found that the amount of isoprenylated and membrane-bound RhoA in RSV-infected cultures was increased. Further evidence of RhoA activation was demonstrated by downstream signaling activity mediated by RhoA. There was an increase in p130(cas) phosphorylation during RSV infection, which was prevented by Y-27632, a specific inhibitor of Rho kinase, or lovastatin, an HMG-CoA reductase inhibitor that reduces the synthesis of groups needed for isoprenylation. In addition, RSV infection of HEp-2 cells resulted in an increase in the formation of actin stress fibers. Pretreatment of HEp-2 cells with Clostridium botulinum C3 exotoxin, an enzyme that specifically ADP-ribosylates and inactivates RhoA, prevented RSV-induced stress fiber formation. These observations indicate that RhoA and subsequent downstream signaling events are activated during RSV infection, which has implications for RSV pathogenesis.

Antiviral activity of lovastatin against respiratory syncytial virus in vivo and in vitro

Respiratory syncytial virus (RSV) is an important human pathogen that can cause severe and life-threatening respiratory infections in infants and immunocompromised adults. We have recently shown that the RSV F glycoprotein, which mediates viral fusion, binds to RhoA. One of the steps in RhoA activation involves isoprenylation at the carboxy terminus of the protein by geranylgeranyltransferase. This modification allows RhoA to be attached to phosphatidyl serine on the inner leaflet of the plasma membrane. Treatment of mice with lovastatin, a drug that inhibits prenylation pathways in the cell by directly inhibiting hydroxymethylglutaryl coenzyme A reductase, diminishes RSV but not vaccinia virus replication when administered up to 24 h after RSV infection and decreases virus-induced weight loss and illness in mice. The inhibition of replication is not likely due to the inhibition of cholesterol biosynthesis, since gemfibrozil, another cholesterol-lowering agent, did not affect virus replication and serum cholesterol levels were not significantly lowered by lovastatin within the time frame of the experiment. Lovastatin also reduces cell-to-cell fusion in cell culture and eliminates RSV replication in HEp-2 cells. These data indicate that lovastatin, more specific isoprenylation inhibitors, or other pharmacological approaches for preventing RhoA membrane localization should be considered for evaluation as a preventive antiviral therapy for selected groups of patients at high risk for severe RSV disease, such as the institutionalized elderly and bone marrow or lung transplant recipients.

QS-21 promotes an adjuvant effect allowing for reduced antigen dose during HIV-1 envelope subunit immunization in humans

Three separate studies were undertaken in HIV-1 uninfected persons to determine if the adjuvant QS-21 improves the magnitude or kinetics of immune responses induced by recombinant soluble gp120 HIV-1(MN) protein (rsgp120) immunization. The QS-21 was administered at two doses (50 and 100 microg), either alone or in combination with aluminum hydroxide (600 microg). At the highest doses of rsgp120 (100, 300, and 600 microg), QS-21 exerted no significant effect on either binding or neutralizing antibody titers. Antibody binding and neutralizing responses fell dramatically when rsgp120, formulated with alum alone, was given at low doses (3 and 30 microg). In contrast, antibody responses similar in titer to those in the high dose antigen groups were induced with the low dose rsgp120 formulated with QS-21. In addition, the lymphocyte proliferation and delayed type hypersensitivity skin testing were superior in the QS-21 recipients compared with the alum recipients at the low antigen doses. Moderate to severe pain was observed in majority of the volunteers receiving QS-21 formulations, and vasovagal episodes and hypertension were not infrequent. Thus, the use of QS-21 may provide a means to reduce the dose of a soluble protein immunogen.

Nasal tip ulceration from infection and extrusion of a nasal alloplastic implant

Nasal augmentation rhinoplasty is a common cosmetic procedure. Alloplastic or synthetic materials are frequently used with Silastic, the most commonly used type worldwide. In the Orient, this common procedure has a low complication rate. However, infection and extrusion of the implant through the skin may occur and patients may be reluctant to report the augmentation procedure to the dermatologist. Therefore, the dermatologist needs to be highly suspicious and include this complication in the differential of ulcerated nasal tip nodules.

Testicular choriocarcinoma metastatic to the skin: an additional case and literature review

Choriocarcinoma, a malignancy of trophoblastic cells, is characterized by the secretion of human chorionic gonadotropin (hCG). Choriocarcinoma primarily arises from the fetal (placental) trophoblasts in the setting of a molar pregnancy. Nongestational choriocarcinoma from the ovary or testis is much rarer. Testicular choriocarcinoma is a malignant tumor with great propensity for distant metastasis. The primary sites of metastasis are the lungs, liver, and brain. Skin metastasis is very rare but portends a grave prognosis when diagnosed. We present the case of a 24-year-old white male with a testicular mixed germ-cell tumor with skin metastases of choriocarcinoma.

Respiratory syncytial virus infection does not increase allergen-induced type 2 cytokine production, yet increases airway hyperresponsiveness in mice

Severe respiratory syncytial virus (RSV)-induced disease is associated with childhood asthma and atopy. We combined murine models of allergen-sensitization and RSV infection to explore the interaction of allergic and virus-induced airway inflammation and its impact on airway hyperresponsiveness (AHR). We found that RSV infection during ova-sensitization (OVA/RSV) increased and prolonged AHR compared to mice only RSV-infected (RSV) or ova-sensitized (OVA). AHR is known to be associated with an increase in Type 2 cytokines (IL-4, IL-5, and IL-13) in allergen-sensitized mice. Therefore, we hypothesized that RSV-induced enhancement of AHR was a result of potentiating the Type 2 cytokine profile promoted by ova-sensitization. Surprisingly, we found that Type 2 cytokines induced by ova-sensitization were not increased by RSV infection despite the increase in AHR, and in some cases were diminished. RNAse protection assay revealed no difference in IL-4 and IL-5 mRNA levels between the OVA and OVA/RSV groups, and IL-13 mRNA was significantly decreased in the OVA/RSV mice compared to the OVA group. Flow cytometric analysis of Type 2 cytokines demonstrated the same frequency of IL-4 and IL-5 production in lung-derived T lymphocytes from the OVA/RSV and OVA groups. Direct cytokine ELISA measurements of lung supernatant showed the level of IL-13 was significantly decreased in the OVA/RSV group compared to OVA mice, while there was no difference in either IL-4 or IL-5 between these two groups. These data indicate that the enhanced and prolonged AHR caused by the interaction of allergic airway inflammation and virus-induced immune responses is a complex process that can not be explained simply by augmented production of Type 2 cytokines.

Pertussis toxin sensitization alters the pathogenesis of subsequent respiratory syncytial virus infection

Evidence suggests that both host and viral factors influence disease severity after infection with respiratory syncytial virus (RSV). To characterize the effects of pertussis toxin (PT) sensitization on subsequent RSV infection, BALB/c mice were treated with PT parenterally before RSV challenge. Priming with purified and detoxified PT before RSV challenge increased postchallenge weight loss and mortality. PT priming changed the kinetics, location, and composition of the cellular infiltrate in the lung but altered neither antibody responses nor virus titers. Passive transfer of PT-sensitized splenocytes produced similar responses. Priming with purified, but not genetically detoxified, PT propagated a modest type 2 cytokine response to RSV antigens. However, anti-interleukin-4 treatment before RSV challenge failed to abrogate the effects of PT priming. These data confirm that the preexisting immune environment can change virus-specific immunity and provide both a model for study of RSV disease and evidence that noninfectious immunomodulators may impact pathogen-specific immunity.

Rippled-pattern sebaceous trichoblastoma

BACKGROUND

There is a large spectrum trichoblastoma; of which, several histologic variants have been described including a rippled-pattern variant. Three cases of rippled-pattern trichoblastoma are described which also exhibited definitive foci of sebaceous differentiation.

METHODS

Three cases were retrieved from the archives of the Dermatopathology Laboratory at the University of California Irvine (Orange, CA, USA). All specimens were stained with hematoxylin and eosin (H&E). In addition, sections were submitted for immunohistochemical studies with epithelial membrane antigen (EMA).

RESULTS

All three biopsies were composed of well-circumscribed multiple variously sized tumor lobules present in the upper to deep dermis comprised of with rounded or slightly elongated basaloid cells with scant eosinophilic cytoplasm. The lobules were separated by a slightly hyalinized stroma. The unique finding present in all three specimens was a peculiar arrangement of the basaloid cells in linear rows parallel to one another. This gave the tumors a rippled pattern similar to the palisading of nuclei of Verocay bodies seen in schwannomas. In addition all three biopsies showed definite sebaceous differentiation.

CONCLUSIONS

Three additional cases of rippled-pattern trichoblastoma are presented. All three were located on the scalp and showed additional features of foci of sebaceous differentiation. No associations with Muir-Torre Syndrome were found in these patients. Because this appears to be a distinct variant within the large spectrum of trichoblastoma, the term rippled-pattern sebaceous trichoblastoma is suggested.

Respiratory syncytial virus (RSV)-induced airway hyperresponsiveness in allergically sensitized mice is inhibited by live RSV and exacerbated by formalin-inactivated RSV

Respiratory syncytial virus (RSV)-induced disease is associated with recurrent episodes of wheezing in children, and an effective vaccine currently is not available. The use of 2 immunizations (a formalin-inactivated, alum-precipitated RSV vaccine [FI-RSV] given intramuscularly and live RSV given intranasally [LVIN]), with a control immunization, were compared in a well-characterized model of RSV challenge, with or without concomitant allergic sensitization with ovalbumin. FI-RSV caused a significant increase in airway hyperresponsiveness in mice after RSV infection during allergic sensitization, and this was associated with an increase in type 2 cytokine production. In contrast, immunization with LVIN did not change type 2 cytokine production and protected against RSV-induced airway hyperresponsiveness in the setting of allergic sensitization. This study suggests that immune modulation with RSV vaccination can have profound effects on RSV-induced airway disease and that prevention of airway hyperresponsiveness is an important end point in vaccine development.

Cyclooxygenase inhibition increases interleukin 5 and interleukin 13 production and airway hyperresponsiveness in allergic mice

The immunomodulatory role of arachidonic acid metabolites in allergic sensitization is undefined. Prostaglandin E(2) (PGE(2)), a product of arachidonic acid metabolism through the cyclooxygenase pathway, has been reported to favor Type 2-like cytokine secretion profiles in murine and human CD4(+) T cells by inhibiting the production of Type 1-associated cytokines. On the basis of these in vitro data, we hypothesized that indomethacin, a nonselective cyclooxygenase inhibitor, would diminish allergen-induced production of Type 2 cytokines in mice, and protect against airway hyperresponsiveness (AHR) to methacholine. We found that ovalbumin-sensitized mice that were treated with indomethacin (OVA-indomethacin mice) had significantly greater AHR (p < 0.05) and higher levels of IL-5 (176 +/- 52 versus 66 +/- 4 pg/ml) and IL-13 (1,226 +/- 279 versus 475 +/- 65 pg/ml) in lung supernatants than mice sensitized with ovalbumin alone (OVA mice), while levels of IL-4 and serum IgE were not different. Lung mRNA expression of the C-C chemokine MCP-1 was increased in OVA-indomethacin mice, while there was no difference between the two groups in lung mRNA expression of eotaxin, MIP-1alpha, MIP-1beta, or MIP-2. Histologic examination revealed greater pulmonary interstitial eosinophilia in OVA-indomethacin mice as well. Contrary to our expectations, we conclude that in the BALB/c mouse, cyclooxygenase inhibition during allergen sensitization increases AHR, production of IL-5 and IL-13, and interstitial eosinophilia.

Immune-mediated disease pathogenesis in respiratory syncytial virus infection

Respiratory syncytial virus (RSV) is an important cause of severe respiratory disease in persons at both extremes of age. Wheezing is a cardinal sign of infection and the illness is associated with an increased incidence of childhood asthma. Data from both humans and animal models have linked severe disease in infants and the syndrome of vaccine-enhanced illness with an aberrant composition of CD4+ T cells, suggestive of an exaggerated Th2 response. Studies in murine models have shown that prior vaccination, coexisting allergic inflammation, or direct modulation of the cytokine milieu can profoundly influence the immune response to RSV and thereby affect the expression of disease. In addition, there are intrinsic antigenic properties of the RSV G glycoprotein that promote Th2 responses and eosinophilia. This paper proposes an integrated working model of how host and virus factors interact to determine the characteristics of RSV-induced illness. This model suggests strategies for the development of new vaccine and immunotherapeutic interventions, and creates a framework for asking additional questions about the immunopathogenesis of RSV.

A phase II study of two HIV type 1 envelope vaccines, comparing their immunogenicity in populations at risk for acquiring HIV type 1 infection. AIDS Vaccine Evaluation Group

Several immunogens induce HIV-specific neutralization and in vitro lymphoproliferation in adults at low HIV-1 risk, but responses in persons at high HIV-1 risk are not known. We performed a multicenter, double-blinded, adjuvant-controlled trial with two gp120 vaccines in 296 HIV-1-uninfected volunteers, including 176 reporting higher HIV-1 risk activities. The immunogens were remarkably well tolerated. After three immunizations, 210 of 241 vaccinees (87%) developed neutralizing antibodies, which persisted in 59% after 2 years. The injection drug users receiving SF-2/gp120 had decreased antibody responses relative to the lower risk groups. Envelope-specific lymphoproliferation peaked after two immunizations, and 54% of vaccinees mounted a DTH reaction to gp120 after 4 years. In summary, these immunogens have low adverse reactogenicity and induce durable antibody and T cell responses to the prototype strains. Unexpected differences in antibody responses among diverse HIV-1 risk strata lend support to the conduct of expanded phase II trials in populations other than low-risk volunteers.

Transepidermal migration of external cardiac pacing wire presenting as a cutaneous nodule

Temporary epicardial pacing wires are used to control postoperative arrhythmias in patients who have undergone open heart surgery. We present an interesting case of a foreign body granuloma resulting from a retained epicardial pacing wire.

IL-4 diminishes perforin-mediated and increases Fas ligand-mediated cytotoxicity In vivo

CTL have evolved two major mechanisms for target cell killing: one mediated by perforin/granzyme secretion and the other by Fas/Fas ligand (L) interaction. Although cytokines are integral to the development of naive CTL into cytolytic effectors, the role of cytokines on mechanisms of CTL killing is just emerging. In this study, we evaluate the effects of IL-4 in Fas(CD95)/FasL(CD95L)-mediated killing of Fas-overexpressing target cells. Recombinant vaccinia viruses (vv) were constructed to express respiratory syncytial virus M2 Ag alone (vvM2) or coexpress M2 and IL-4 (vvM2/IL-4). MHC-matched Fas-overexpressing target cells (L1210Fas+) were used to measure both perforin- and FasL-mediated killing pathways. In contrast to Fas-deficient (L1210Fas-) target cells, effectors from vvM2/IL-4-immunized mice were able to lyse L1210Fas+ target cells with similar magnitude as vvM2-infected mice. Addition of EGTA/Mg2+ revealed that effectors from vvM2/IL-4-infected mice primarily lyse targets by a Ca2+-independent Fas/FasL pathway. Analysis of FasL expression by flow cytometry showed that IL-4 increased cell surface FasL expression on CD4+ and CD8+ splenocytes, with peak expression on day 4 after infection. These data demonstrate that IL-4 increases FasL expression on T cells, resulting in a shift of the mechanism of CTL killing from a dominant perforin-mediated cytolytic pathway to a dominant FasL-mediated cytolytic pathway.

Interleukin-4 diminishes CD8(+) respiratory syncytial virus-specific cytotoxic T-lymphocyte activity in vivo

Although interleukin-4 (IL-4) has been implicated in respiratory syncytial virus (RSV)-enhanced disease, the mechanism by which it modulates immune responses to primary RSV infection remains unclear. We have developed a system to investigate the effect of IL-4 on RSV epitope-specific cytotoxic T-lymphocyte (CTL) effector function in vivo, using an H-2K(d)-restricted RSV M2 epitope. BALB/c mice were infected with recombinant vaccinia virus (rVV) constructed to express RSV M2 protein (vvM2) alone or coexpress M2 and IL-4 (vvM2/IL-4). Splenocytes were assessed for M2-specific CTL activity in a direct (51)Cr release assay and intracellular gamma interferon (IFN-gamma) production by fluorescence-activated cell sorting analysis. Mice infected with vvM2/IL-4 had less M2-specific primary CTL activity than those infected with vvM2. M2-specific CTL frequency, as measured by M2 peptide-induced intracellular IFN-gamma production, was diminished in the vvM2/IL-4 group, partially accounting for the reduction of CTL activity. Mice immunized with either construct were challenged intravenously with RSV 4 weeks postimmunization, and direct CTL were measured. These results demonstrate that local expression of IL-4, at the time of antigen presentation, diminishes the cytolytic activity of primary and memory CD8(+) RSV-specific CTL responses in vivo.

Passive IgA monoclonal antibody is no more effective than IgG at protecting mice from mucosal challenge with respiratory syncytial virus

Respiratory syncytial virus (RSV) is a mucosally restricted pathogen that can cause severe respiratory disease. Although parenteral administration of sufficient RSV-specific IgG can reduce severity of lower respiratory tract infection in high-risk infants, delivery of antibody by direct airway administration is an attractive alternative. Topical and parenteral administration of an IgA monoclonal antibody (MAb) specific for the RSV F glycoprotein was compared with an IgG MAb, specific for the same antigenic site, for ability to protect mice against RSV infection. Administration of RSV-specific IgG was more effective in reducing RSV titers in lung (4.6 log10 pfu/g) than IgA MAb (3.6 log10 pfu/g) when given intranasally immediately prior to infection (P=.005). RSV titers in the nose were reduced only by prophylactic administration of IgG parenterally. Therefore, topical administration of IgA is no more effective than topically administered IgG and is less effective than systemically administered IgG for protecting against RSV infection.

Secreted respiratory syncytial virus G glycoprotein induces interleukin-5 (IL-5), IL-13, and eosinophilia by an IL-4-independent mechanism

The attachment glycoprotein G of respiratory syncytial virus (RSV) is produced as both membrane-anchored and secreted forms by infected cells. Immunization with secreted RSV G (Gs) or formalin-inactivated alumprecipitated RSV (FI-RSV) predisposes mice to immune responses involving a Th2 cell phenotype which results in more severe illness and pathology, decreased viral clearance, and increased pulmonary eosinophilia upon subsequent RSV challenge. These responses are associated with increased interleukin-4 (IL-4) production in FI-RSV-primed mice, and the responses are IL-4 dependent. RNase protection assays demonstrated that similar levels of IL-4 mRNA were induced after RSV challenge in mice primed with vaccinia virus expressing Gs (vvGs) or a construct expressing only membrane-anchored G (vvGr). However, upon RSV challenge, vvGs-primed mice produced significantly greater levels of IL-5 and IL-13 mRNA and protein than vvGr-primed mice. Administration of neutralizing anti-IL-4 antibody 11.B11 during vaccinia virus priming did not alter the levels of vvGs-induced IL-5, IL-13, pulmonary eosinophilia, illness, or RSV titers upon RSV challenge, although immunoglobulin G (IgG) isotype profiles revealed that more IgG2a was produced. vvGs-priming of IL-4-deficient mice demonstrated that G-induced airway eosinophilia was not dependent on IL-4. In contrast, airway eosinophilia induced by FI-RSV priming was significantly reduced in IL-4-deficient mice. Thus we conclude that, in contrast to FI-RSV, the secreted form of RSV G can directly induce IL-5 and IL-13, producing pulmonary eosinophilia and enhanced illness in RSV-challenged mice by an IL-4-independent mechanism.

RhoA interacts with the fusion glycoprotein of respiratory syncytial virus and facilitates virus-induced syncytium formation

The fusion glycoprotein (F) of respiratory syncytial virus (RSV), which mediates membrane fusion and virus entry, was shown to bind RhoA, a small GTPase, in yeast two-hybrid interaction studies. The interaction was confirmed in vivo by mammalian two-hybrid assay and in RSV-infected HEp-2 cells by coimmunoprecipitation. Furthermore, the interaction of F with RhoA was confirmed in vitro by enzyme-linked immunosorbent assay and biomolecular interaction analysis. Yeast two-hybrid interaction studies with various deletion mutants of F and with RhoA indicate that the key binding domains of these proteins are contained within, or overlap, amino acids 146 to 155 and 67 to 110, respectively. The biological significance of this interaction was studied in RSV-infected HEp-2 cells that were stably transfected to overexpress RhoA. There was a positive correlation between RhoA expression and RSV syncytium formation, indicating that RhoA can facilitate RSV-induced syncytium formation.

Prophylaxis with respiratory syncytial virus F-specific humanized monoclonal antibody delays and moderately suppresses the native antibody response but does not impair immunity to late rechallenge

Respiratory syncytial virus (RSV) is the most significant viral cause of lower respiratory tract disease in infants and children. This study tested the hypothesis that a humanized murine monoclonal antibody (MAb) would protect against RSV infection in mice and have minimal suppressive effect upon the immune response because it is directed against a single epitope. A humanized murine MAb (RSHZ19) was tested for both prophylaxis and treatment of RSV infection in BALB/c mice and compared with a polyclonal product. Mice were rechallenged when passively administered antibody was undetectable (day 104). RSHZ19 reduced virus titer and protected against illness when used in prophylaxis and effected rapid virus clearance when used as treatment. Polyclonal antibody was also an effective prophylaxis but required 200 times the dose in total protein. Peak neutralizing antibody responses were delayed and somewhat suppressed in the prophylactically treated groups, but mice were protected against infection on rechallenge. Secondary antibody response to rechallenge in passively immunized mice was equal to that in untreated mice.

Vaccination with pertussis toxin alters the antibody response to simultaneous respiratory syncytial virus challenge

Many bacterial toxins, including pertussis toxin (PT), exert potent adjuvant effects on antibody synthesis to coadministered antigens. In these studies, we examined whether locally or peripherally administered PT similarly altered the antibody isotype selection to replicating virus after intranasal (inl) challenge. Mice primed intramuscularly with PT and inl with respiratory syncytial virus (RSV) produced RSV-specific antibodies of the IgG2a isotype at a level similar to that of unprimed controls, with some increase in IgG1 production. Mice primed inl with both PT and RSV showed elevated RSV-specific IgG1, increased serum IgE levels, and increased interleukin (IL)-4 in lung supernatants. Splenocytes from these animals produced increased IL-4 when stimulated in vitro with RSV or PT antigens after infection. These results suggest that PT can influence the local production of IL-4 to alter the humoral and cellular immune responses to viral infection as well as to coadministered antigens.