Digital quantification of p16-positive foci in fibrotic interstitial lung disease is associated with a phenotype of idiopathic pulmonary fibrosis with reduced survival.

BACKGROUND: Idiopathic pulmonary fibrosis (IPF) is associated with increased expression of cyclin-dependent kinase inhibitors such as p16 and p21, and subsequent induction of cell cycle arrest, cellular senescence, and pro-fibrotic gene expression. We sought to link p16-expression with a diagnosis of IPF or other fibrotic interstitial lung diseases (ILDs), radiographic pattern, senescent foci-specific gene expression, antifibrotic therapy response, and lung transplant (LTx)-free survival. METHODS: Eighty-six cases of fibrosing ILD were identified with surgical lung biopsy. Immunohistochemistry for p16 was performed on sections with the most active fibrosis. p16-positive foci (loose collection of p16-positive fibroblasts with overlying p16-positive epithelium) were identified on digital slides and quantified. Cases were scored as p16-low (≤ 2.1 foci per 100 mm2) or p16-high (> 2.1 foci per 100 mm2). Twenty-four areas including senescent foci, fibrotic and normal areas were characterized using in situ RNA expression analysis with digital spatial profiling (DSP) in selected cases. RESULTS: The presence of p16-positive foci was specific for the diagnosis of IPF, where 50% of cases expressed any level of p16 and 26% were p16-high. There was no relationship between radiographic pattern and p16 expression. However, there was increased expression of cyclin-dependent kinase inhibitors, collagens and matrix remodeling genes within p16-positive foci, and cases with high p16 expression had shorter LTx-free survival. On the other hand, antifibrotic therapy was significantly protective. DSP demonstrated that fibroblastic foci exhibit transcriptional features clearly distinct from that of normal-looking and even fibrotic areas. CONCLUSIONS: We demonstrated the potential clinical applicability of a standardized quantification of p16-positive fibroblastic foci. This method identifies an IPF phenotype associated with foci-specific upregulation of senescence-associated and matrix remodeling gene expression. While these patients have reduced LTx-free survival, good response to antifibrotic therapies was observed in those who were treated.

Incidental Merkel cell carcinoma in a cutaneous horn: a case report.

Merkel cell carcinoma (MCC) is a rare cutaneous neuroendocrine malignancy, which usually presents as an asymptomatic, rapidly growing, firm nodule on sun-damaged skin. We present a 93-year-old female who presented with a "cutaneous horn" on the face. On excision, histologic examination revealed a combined squamous cell carcinoma in situ with underlying MCC. Merkel cell polyomavirus immunohistochemistry was negative in this lesion. This case report highlights the significant association between MCC and squamous cell carcinoma and the uncommon clinical presentation of this combined tumor in the form of a cutaneous horn.

The effect of tidal volume on systemic inflammation in Acid-induced lung injury.

BACKGROUND: Overwhelming systemic inflammation has been implicated in the progression of acute lung injury (ALI) leading to multiple organ failure (MOF) and death. Previous studies suggest that mechanical ventilation (MV) may be a key mediator of MOF through an upregulation of the systemic inflammatory response. OBJECTIVES: It was the aim of this study to investigate mechanisms whereby mechanical stress induced by different tidal volumes may contribute to the development of systemic inflammation and maladaptive peripheral organ responses in the setting of ALI. METHODS: An acid aspiration model of ALI was employed in 129X1/SVJ mice through an intratracheal administration of hydrochloric acid followed by MV employing either a low (5 ml/kg) or high (12.5 ml/kg) tidal volume ventilation for 120 min. The isolated perfused mouse lung setup was used to assess the specific contribution of the lung to systemic inflammation during MV. Furthermore, lung perfusate collected over the course of MV was used to assess the effects of lung-derived mediators on activation (expression of a proadhesive phenotype) of liver endothelial cells. RESULTS: High tidal volume MV of acid-injured lungs resulted in greater physiologic and histological indices of lung injury compared to control groups. Additionally, there was an immediate and significant release of multiple inflammatory mediators from the lung into the systemic circulation which resulted in greater levels of mRNA adhesion molecule expression in liver endothelial cells in vitro. CONCLUSIONS: This study suggests that MV, specifically tidal volume strategy, influences the development of MOF through an upregulation of lung-derived systemic inflammation resulting in maladaptive cellular changes in peripheral organs.

Topical imiquimod therapy for lentigo maligna.

Lentigo maligna (LM) presents a challenge for complete surgical excision. Imiquimod is a topical immune-response modifier that acts on the immune system. We report our experience using imiquimod 5% cream as a surgical alternative for treatment of LM. Consecutive patients between December 2004 and February 2006 with LM were treated with topical imiquimod. Data on patient and lesion characteristics, side effects of therapy, posttreatment biopsy results, and follow-up was collected. Seven patients were treated with imiquimod 5 nights/wk for 12.4 weeks. Complete histologic and clinical resolution was seen in 86% (6 of 7 patients), at 19.1 months follow-up. Side effects included erythema (86%) and crusting (71%), resulting in dose alteration in 71% of patients. Topical imiquimod therapy demonstrates a high response rate for treatment of LM, with tolerable side effects. Further investigation into its efficacy in the treatment of LM in controlled clinical trials is warranted.

Effects of nebulized diethylenetetraamine-NONOate in a mouse model of acute Pseudomonas aeruginosa pneumonia.

OBJECTIVE: Endogenous and exogenous nitric oxide (NO) may have important antibacterial effects in patients with pneumonia. NO administration has been limited to the continuous inhalation of gas-phase NO (ie, inhaled NO [iNO]). Intermittent nebulization of NONOates, novel NO donors, may permit the continuous intrapulmonary delivery of NO. Thus, we assessed the effects of nebulized diethylenetetraamine-NONOate (DETA-NO) in a model of acute Pseudomonas aeruginosa pneumonia. DESIGN: Randomized, controlled study. SUBJECTS: Male C57Bl/6 mice. INTERVENTIONS: Pneumonia was induced by intratracheal instillation of P aeruginosa (3 x 10(7) CFU in 50 microL). Pneumonia and sham mice were randomized to receive no treatment, nebulized DETA-NO (12.5 or 125 micromol) at 4 h and 12 h, or continuous iNO for 24 h (10 or 40 ppm) until they were killed at 24 h. MAIN RESULTS: The nebulization of DETA-NO was associated with a marked increase in mean (+/- SEM) exhaled NO levels (after nebulization, 484 +/- 34 parts per billion [ppb]; baseline, 13.4 +/- 0.4 ppb; p < 0.01) and plasma levels of nitrites/nitrates (after nebulization, 73 +/- 28 microM; at baseline, 14 +/- 3 microM; p < 0.05). Nebulized DETA-NO decreased the pulmonary bacterial load in mice with pneumonia by 65 +/- 19% (p < 0.05 vs untreated mice) but had no effect on pulmonary leukocyte infiltration. Although the growth of P aeruginosa colonies in vitro was impaired on exposure to DETA-NO, growth was similarly impaired by exposure to DETA nucleophile/backbone alone. CONCLUSIONS: The nebulization of DETA-NO provides a method for the prolonged intrapulmonary delivery of NO. The antibacterial effect of DETA-NO in vivo and in vitro is due, in large part, to the DETA nucleophile moiety and is independent of NO, suggesting a limited therapeutic role for exogenous NO in pneumonia.

Role of inducible nitric oxide synthase in pulmonary microvascular protein leak in murine sepsis.

The effects of nitric oxide (NO) from calcium-independent NO synthase (iNOS) on microvascular protein leak in acute lung injury (ALI) are uncertain, possibly because of disparate effects of iNOS-derived NO from different cells. We assessed the contribution of iNOS from inflammatory versus parenchymal cells to pulmonary protein leak in murine cecal ligation and perforation-induced ALI. We studied iNOS+/+, iNOS-/-, and two reciprocally bone marrow-transplanted iNOS chimeric mice groups: + to - (iNOS+/+ donor bone marrow-transplanted into iNOS-/- recipient mice) and - to +. Sepsis-induced ALI was characterized by pulmonary leukocyte infiltration, increased pulmonary iNOS activity, and increased pulmonary microvascular protein leak, as assessed by Evans blue (EB) dye. Despite equal neutrophil infiltration, sepsis-induced EB-protein leak was eliminated in iNOS-/- mice and in - to + iNOS chimeras (parenchymal cell-localized iNOS) but was preserved in + to - chimeric mice (inflammatory cell-localized iNOS). EB-protein leak was also prevented by pretreatment with allopurinol and superoxide dismutase. Microvascular protein leak in sepsis-induced ALI is uniquely dependent on iNOS in inflammatory cells with no obvious contribution of iNOS in pulmonary parenchymal cells. Pulmonary protein leak is also dependent on superoxide, suggesting an effect of peroxynitrite rather than NO itself.