Loss of alcohol dehydrogenase 1B in cancer-associated fibroblasts: contribution to the increase of tumor-promoting IL-6 in colon cancer

BACKGROUND

Increases in IL-6 by cancer-associated fibroblasts (CAFs) contribute to colon cancer progression, but the mechanisms involved in the increase of this tumor-promoting cytokine are unknown. The aim of this study was to identify novel targets involved in the dysregulation of IL-6 expression by CAFs in colon cancer.

METHODS

Colonic normal (N), hyperplastic, tubular adenoma, adenocarcinoma tissues, and tissue-derived myo-/fibroblasts (MFs) were used in these studies.

RESULTS

Transcriptomic analysis demonstrated a striking decrease in alcohol dehydrogenase 1B (ADH1B) expression, a gene potentially involved in IL-6 dysregulation in CAFs. ADH1B expression was downregulated in approximately 50% of studied tubular adenomas and all T1-4 colon tumors, but not in hyperplastic polyps. ADH1B metabolizes alcohols, including retinol (RO), and is involved in the generation of all-trans retinoic acid (atRA). LPS-induced IL-6 production was inhibited by either RO or its byproduct atRA in N-MFs, but only atRA was effective in CAFs. Silencing ADH1B in N-MFs significantly upregulated LPS-induced IL-6 similar to those observed in CAFs and lead to the loss of RO inhibitory effect on inducible IL-6 expression.

CONCLUSION

Our data identify ADH1B as a novel potential mesenchymal tumor suppressor, which plays a critical role in ADH1B/retinoid-mediated regulation of tumor-promoting IL-6.

The ROS scavenger, NAC, regulates hepatic Vα14iNKT cells signaling during Fas mAb-dependent fulminant liver failure

Uncontrolled systemic activation of the immune system is an early initiating event that leads to development of acute fulminant liver failure (FLF) in mice after treatment with agonistic Fas mAb. In this study, we demonstrate that treatment of mice with N-acetylcysteine (NAC), an ROS scavenger and glutathione (GSH) precursor, almost completely abolished Fas mAb-induced FLF through suppression of Vα14iNKT cell activation, IFN-γ signaling, apoptosis and nitrotyrosine formation in liver. In addition, enrichment of the liver with GSH due to Vα14iNKT cells deficiency, induced an anti-inflammatory response in the liver of Jα18(-/-) mice that inhibited apoptosis, nitrotyrosine formation, IFN-γ signaling and effector functions. In summary, we propose a novel and previously unrecognized pro-inflammatory and pro-apoptotic role for endogenous ROS in stimulating Th1 signaling in Vα14iNKT cells to promote the development of FLF. Therefore, our study provides critical new insights into how NAC, a ROS scavenger, regulates Th1 signaling in intrahepatic Vα14iNKT cells to impact inflammatory and pathological responses.

Cytomorphology, ultrastructural, and cytogenetic findings in follicular dendritic cell sarcoma: a case report

BACKGROUND

Follicular dendritic cell (FDC) sarcoma is a rare low-to-intermediate grade malignant dendritic cell neoplasm that often has an indolent clinical course. FDC sarcomas are often misdiagnosed on aspiration cytology.

CASE

A 26-year-old woman presented with a solid, slowly growing, painless mass in her right neck for 3 months. Computed tomography revealed a 3.6-cm, well-defined homogenous solid mass located posterior to the mandible and submandibular glands. Fine needle aspiration cytology revealed many large, spindle to ovoid epithelioid cells in singles, small clusters, and syncytial sheets with moderate to abundant cytoplasm, indistinct cell borders, irregular nuclear membrane, fine to vesicular chromatin, and conspicuous nucleoli. The background contained many small mature lymphocytes intimately mixed with large epithelioid tumor cells. Tumor cells were strongly positive for CD21, CD35, CD23, and fascin. Diagnosis of FDC sarcoma was rendered; follow-up surgical resection and ultrastructural study confirmed the diagnosis. The cytogenetic study showed a normal female karyotype 46,XX.

CONCLUSION

Although the cytomorphology of FDC sarcoma is characteristic, a preoperative diagnosis of FDC sarcoma based on fine needle aspiration cytology is very challenging, if not impossible. Immunohistochemistry is always necessary for rendering and/or confirming the diagnosis, and ultrastructural studies are helpful.

Stromal expression of actin is a marker of aggressiveness in basal cell carcinoma

Basal cell carcinoma is a very common malignant skin tumor that rarely metastasizes but is often locally aggressive. In a number of studies conducted by different investigators, Bcl2, beta-catenin, cyclin D1, hMSH2, and alpha-smooth muscle actin have been reported to have potential for predicting basal cell carcinoma aggressiveness. However, these reports were inconclusive and sometimes contradictory. We therefore studied the expression and topographic locations (tumor versus stroma) of all these gene products in a group of clinically proven aggressive basal cell carcinomas (n = 30) and randomly selected control cases of nonaggressive basal cell carcinomas (n = 33). The results were subjected to statistical analysis with Mann-Whitney test and logistic regression. The accuracy of the resulting significant discriminating criteria was further tested using the omnibus tests of model coefficients. With multivariate analysis, differential expression of Bcl-2, beta-catenin, and cyclin D1 was not significantly different between aggressive and nonaggressive tumors. hMSH2 expression was up-regulated in the aggressive tumors (P = .005). Alpha-smooth muscle actin was expressed by tumor cells in both study groups, but stromal expression of alpha-smooth muscle actin was restricted to the aggressive tumors and highly predictive of aggressive behavior (P < .001; accuracy, 87%). Logistic regression combining the expression of alpha-smooth muscle actin and hMSH2 yielded a predictive model with 97% accuracy (P < .001). These data show conclusively that aggressive basal cell carcinomas express alpha-smooth muscle actin in the stroma, whereas nonaggressive basal cell carcinomas express alpha-smooth muscle actin in the tumor cells, and that stromal expression of alpha-smooth muscle actin is an accurate, reliable, and easy to use marker of aggressiveness in basal cell carcinomas and can be used in clinical practice for surgical therapeutic decisions.

Relationship between eosinophils and chronic endometritis

The histopathologic diagnosis of chronic endometritis is based on the presence of plasma cells in the endometrial stroma. However, many conditions can mimic or interfere with the search for plasma cells, including the plasmacytoid stroma cells and predecidual changes of stroma cells. Eosinophils are another type of chronic inflammatory cells, which can be easily identified with routine hematoxylin and eosin stain by their characteristic eosinophilic granules. This study was conducted to investigate whether eosinophils can be used as diagnostic markers of chronic endometritis. The hematoxylin and eosin-stained glass slides of 422 consecutive endometrial biopsies were reviewed. The biopsies that have eosinophils were subjected to immunohistochemical staining with CD138, a marker for plasma cells. In all, 91 of 422 biopsies contained eosinophils with 72.5% (66/91) showing presence of plasma cells (positive staining with CD138). Of these 66 cases, only 4 cases were previously diagnosed as chronic endometritis. These results suggest the presence of eosinophils in endometrial biopsy specimen indicates a need to search for plasma cells (with immunohistochemical stain if needed) for the diagnosis of chronic endometritis.

Immunohistochemical profiling of cytokeratin expression by endometrial stroma sarcoma

Endometrial stromal sarcomas can be confused with several neoplasms because of their inconsistent and widely varied morphologic appearance and frequent immunohistochemical expression of a variety of antigens including cytokeratin. The resulting diagnostic challenge becomes problematic particularly in the diagnosis of metastases resulting from such tumors. Because of the sometime epithelioid appearance of the tumor cells and their expression of cytokeratin, the metastases may be misdiagnosed as poorly differentiated carcinoma. We therefore studied the profile of cytokeratin proteins expression in 17 cases of endometrial stromal sarcomas using a panel of antibodies including cytokeratin cocktail antibody (AE1/AE 3), CK5/6, CK7, CK14, CK16, Cam5.2 (CK8), CK19, CK20, and 34Ebeta12 (CK1, 5, 10, and 14). Of the 17 cases, 8 (47%) stained positive with the cytokeratin cocktail antibody (AE1/AE 3). Of the 8 cases with cytokeratin expression, 5 (63%) stained positive with CK19, and 3 of them stained positive with Cam5.2. The 3 cases that stained positive with Cam5.2 also expressed CK19. Of the 5 cases with CK19, 1 was focally positive for CK5/6, CK7, and 34Ebeta12. None of the cases expressed CK14, CK16, or CK20. These results show that CK19 is most commonly expressed cytokeratin in endometrial stromal tumors. Hence, the inclusion of CK19 in the panel of immunostains may help resolve the diagnostic confusion created by keratin expression in endometrial stromal sarcoma and may also help in the correct diagnosis of endometrial stromal sarcoma at extrauterine sites.

Pneumocystis jiroveci Pneumonia

Pneumocystis pneumonia (PCP) is one of the most common pulmonary infections in persons with impaired cell-mediated immunity, and particularly those infected with human immunodeficiency virus (HIV).1–7 Pneumocystis was first described in the lungs of guinea pigs, during experiments on American trypanosomiasis by Carlos Chagas8 in 1909 and by Antonio Carinii9 in 1910. Both considered the cysts of Pneumocystis as part of the trypanosome’s life cycle. Shortly afterward the Delanoes10 found identical forms in the lungs of rats that had not been infected with trypanosomes and recognized the organism as a separate species. The name Pneumocystis carinii, was given to this organism as a generic name (Greek:pneumon, “lung”; kystis, “cyst”), honoring Carinii.11

Non-pathogenic Sindbis virus causes hemorrhagic fever in the absence of alpha/beta and gamma interferons

The role of interferon-gamma (IFNgamma) in antiviral innate immune responses during acute alphavirus infection is not well defined. We examined the contribution of IFNgamma to the protection of adult mice from Sindbis virus (SB)-induced disease by comparing subcutaneous infection of mice lacking receptors for either IFNalpha/beta (A129), IFNgamma (G129) or both (AG129) to normal mice (WT129). While neither G129 nor WT129 mice exhibited clinical signs of disease, infection of A129 or AG129 mice was fatal with AG129 mice succumbing more rapidly. Furthermore, AG129 mice developed signs of viral hemorrhagic fever (VHF), including extensive hepatocellular damage, inflammatory infiltrates in multiple organs and vascular leakage, which were significantly delayed and/or partially ameliorated during fatal A129 infections. We conclude that: (i) IFNalpha/beta is the primary mediator of innate immunity to SB infection, however; (ii) IFNgamma is directly antiviral in vivo, acting before the adaptive immune response appears and; (iii) development of VHF may involve viral suppression of both IFNalpha/beta and IFNgamma responses.

Subepithelial myofibroblasts are novel nonprofessional APCs in the human colonic mucosa

The human gastrointestinal mucosa is exposed to a diverse normal microflora and dietary Ags and is a common site of entry for pathogens. The mucosal immune system must respond to these diverse signals with either the initiation of immunity or tolerance. APCs are important accessory cells that modulate T cell responses which initiate and maintain adaptive immunity. The ability of APCs to communicate with CD4+ T cells is largely dependent on the expression of class II MHC molecules by the APCs. Using immunohistochemistry, confocal microscopy, and flow cytometry, we demonstrate that alpha-smooth muscle actin(+), CD90+ subepithelial myofibroblasts (stromal cells) constitutively express class II MHC molecules in normal colonic mucosa and that they are distinct from professional APCs such as macrophages and dendritic cells. Primary isolates of human colonic myofibroblasts (CMFs) cultured in vitro were able to stimulate allogeneic CD4+ T cell proliferation. This process was dependent on class II MHC and CD80/86 costimulatory molecule expression by the myofibroblasts. We also demonstrate that CMFs, engineered to express a specific DR4 allele, can process and present human serum albumin to a human serum albumin-specific and DR4 allele-restricted T cell hybridoma. These studies characterize a novel cell phenotype which, due to its strategic location and class II MHC expression, may be involved in capture of Ags that cross the epithelial barrier and present them to lamina propria CD4+ T cells. Thus, human CMFs may be important in regulating local immunity in the colon.

Subepithelial Myofibroblasts are Novel Nonprofessional APCs in the Human Colonic Mucosa

The human gastrointestinal mucosa is exposed to a diverse normal microflora and dietary Ags and is a common site of entry for pathogens. The mucosal immune system must respond to these diverse signals with either the initiation of immunity or tolerance. APCs are important accessory cells that modulate T cell responses which initiate and maintain adaptive immunity. The ability of APCs to communicate with CD4+ T cells is largely dependent on the expression of class II MHC molecules by the APCs. Using immunohistochemistry, confocal microscopy, and flow cytometry, we demonstrate that alpha-smooth muscle actin(+), CD90+ subepithelial myofibroblasts (stromal cells) constitutively express class II MHC molecules in normal colonic mucosa and that they are distinct from professional APCs such as macrophages and dendritic cells. Primary isolates of human colonic myofibroblasts (CMFs) cultured in vitro were able to stimulate allogeneic CD4+ T cell proliferation. This process was dependent on class II MHC and CD80/86 costimulatory molecule expression by the myofibroblasts. We also demonstrate that CMFs, engineered to express a specific DR4 allele, can process and present human serum albumin to a human serum albumin-specific and DR4 allele-restricted T cell hybridoma. These studies characterize a novel cell phenotype which, due to its strategic location and class II MHC expression, may be involved in capture of Ags that cross the epithelial barrier and present them to lamina propria CD4+ T cells. Thus, human CMFs may be important in regulating local immunity in the colon.

Antioxidant treatment ameliorates respiratory syncytial virus-induced disease and lung inflammation

RATIONALE

Respiratory syncytial virus (RSV) is a major cause of lower respiratory tract infection in children. No treatment has been shown to significantly improve the clinical outcome of patients with this infection. Recent evidence suggests that oxidative stress could play an important role in the pathogenesis of acute and chronic lung inflammatory diseases. We do not known whether RSV induces pulmonary oxidative stress and whether antioxidant treatment can modulate RSV-induced lung disease.

OBJECTIVES

To investigate the effect of antioxidant administration on RSV-induced lung inflammation, clinical disease, and airway hyperreactivity (AHR).

METHODS

BALB/c mice were infected with 10(7) plaque-forming units of RSV, in the presence or absence of orally administered butylated hydroxyanisole (BHA), an antioxidant. Malondialdehyde and 4-hydroxynonenal were measured in bronchoalveoar lavage (BAL) by colorimetric assay. Cytokines and chemokines were measured in BAL by Bio-Plex and leukotrienes were measured by enzyme-linked immunosorbent assay. AHR to methacholine challenge was measured by whole-body plethysmography.

RESULTS

BHA treatment significantly attenuated RSV-induced lung oxidative stress, as indicated by the decrease of malondialdehyde and 4-hydroxynonenal content in BAL of RSV-infected mice. RSV-induced clinical illness and body weight loss were also reduced by BHA treatment, which inhibited neutrophil recruitment to the lung and significantly reduced pulmonary cytokine and chemokine production after RSV infection. Similarly, antioxidant treatment attenuated RSV-induced AHR.

CONCLUSION

Modulation of oxidative stress represents a potential novel pharmacologic approach to ameliorate RSV-induced acute lung inflammation and potentially prevent long-term consequences associated with RSV infection, such as bronchial asthma.

Downregulation of TNF-Related Apoptosis-Inducing Ligand (TRAIL)/Apo2L in Barrett's Esophagus With Dysplasia and Adenocarcinoma

TRAIL/Apo2L is a CD95 ligand-related member of the TNF family that initiates apoptosis in immune and neoplastic cells after binding to specific surface receptors. The authors previously reported a specific topographic pattern of TRAIL expression in the normal colonic mucosa and the loss of TRAIL expression in tubular adenomas as well as in most colon carcinomas. Therefore, they hypothesized that similar changes may occur during the malignant transformation of Barrett's esophagus. The aim of this study was to compare TRAIL/Apo2L expression in normal gastroesophageal (GE) junction, Barrett's esophagus with and without dysplasia, and associated adenocarcinoma. Immunohistochemical evaluation of TRAIL expression was performed on formalin-fixed paraffin-embedded sections from 29 GE junction/esophageal biopsies, 20 gastric biopsies, 6 esophagectomies, 2 small bowel resection specimens, and 5 colon biopsies. The expression was graded semiquantitatively on a 4-point scale (0-3). TRAIL was expressed in the foveolar epithelium of the histologically normal GE junctional mucosa and stomach as well as in the normal intestinal epithelium, with maximal expression in the surface epithelium. TRAIL was always detected in Barrett's metaplasia (21/21, 100%), and the overall expression was similar to that of the columnar portion of the normal GE junction (8/8, 100%). TRAIL was rarely and weakly (1+) expressed in Barrett's esophagus with dysplasia (3/18, 16.7%) and adenocarcinoma (1/10, 10.0%) (P<0.001). Similarities in the topographic pattern of TRAIL expression in the normal GE junction, stomach, small intestine, and colon suggest a common function of TRAIL throughout the gastrointestinal tract. These results show that the downregulation of TRAIL is associated with development of dysplasia in Barrett's esophagus. Thus, the immunohistochemically detected downregulation of TRAIL expression appears to be a promising indicator of dysplasia in Barrett's esophagus.

Hedgehog signaling is activated in subsets of esophageal cancers

The hedgehog pathway plays a critical role in the development of the foregut. However, the role of the hedgehog pathway in primary esophageal cancers is not well studied. Here, we report that elevated expression of hedgehog target genes occurs in 14 of 22 primary esophageal cancers. The hedgehog signaling activation is not associated with tumor subtypes, stages, or differentiation. While the sonic hedgehog (Shh) transcript is localized to the tumor tissue, expression of Gli1 and PTCH1 is observed both in the tumor and in the stroma. We discovered that 4 esophageal squamous cell carcinomas, which overexpress Shh, have genomic amplification of the Shh gene. Treatment of esophageal cancer cells with smoothened antagonist, KAAD-cyclopamine, or the neutralizing antibodies of Shh reduces cell growth and induces apoptosis. Overexpression of Gli1 under the CMV promoter renders these cells resistant to the treatments. Thus, our results indicate that elevated expression of Shh and its target genes is quite common in esophageal cancers. Our data also indicate that downregulation of Gli1 expression may be an important mechanism by which KAAD-cyclopamine inhibits growth and induces apoptosis in esophageal cancer cells.

Hemangioma versus vascular malformation: presence of nerve bundle is a diagnostic clue for vascular malformation

CONTEXT

Arteriovenous vascular malformations and hemangiomas are benign vascular lesions that are difficult to distinguish from one another clinically. Also, they may be confused with each other at histopathology. Therefore, histochemical stains for the presence of an artery are frequently used to distinguish between the two.

OBJECTIVE

Because it is clinically relevant to differentiate between arteriovenous vascular malformations and hemangiomas, this study was carried out to explore additional diagnostic clues that may help in the diagnosis and differentiation of these lesions.

DESIGN

A total of 167 cases of benign extracranial vascular lesions were retrieved from the anatomic pathology file of our institution. These comprised 66 cases diagnosed as arteriovenous vascular malformations and 101 cases previously diagnosed as hemangiomas. The hematoxylin-eosin-stained glass slides were reviewed, Movat pentichrome histochemical stain was used to identify elastic vessels (arteries/arterioles), and S100 immunostain was used to identify nerves within these vascular lesions. For immunohistochemistry, the avidin-biotin detection method was used.

RESULTS

With Movat stain, the presence of thick-walled elastic arteries was detected in 12 of the 101 cases previously diagnosed as hemangiomas, and these cases were therefore reclassified as vascular malformations. Using the same criterion, 2 of the 66 cases originally diagnosed as arteriovenous vascular malformations were reclassified as hemangiomas because they lacked arterial structures. Thus, with this strict criterion, we ended up with 91 cases of hemangiomas and 76 cases of arteriovenous vascular malformations. Intralesional nerves were identified in 91% (69/76) of cases of arteriovenous vascular malformations, including all the 12 arteriovenous vascular malformations previously diagnosed as hemangiomas. In contrast, no intralesional nerve was detected in any of the 91 hemangiomas.

CONCLUSIONS

These results show that nerve bundles are consistently present in vascular malformations and absent in hemangiomas and so can be used as a diagnostic clue to differentiate between these lesions. Also, in addition to describing a previously unreported component of vascular malformations, these data further confirm the hamartomatous nature of these lesions.

Activity and regulation of alpha interferon in respiratory syncytial virus and human metapneumovirus experimental infections

Respiratory syncytial virus (RSV) and human metapneumovirus (hMPV) cause a similar spectrum of respiratory infections in humans. Classified within the Paramyxoviridae family, Pneumovirinae subfamily, RSV and hMPV present a significant degree of divergence in genome constellation, organization, and protein sequences. RSV has been reported to be a poor inducer of alpha/beta interferons (IFN-alpha/beta) and partially resistant to its antiviral activity. The nature of the innate immune response to hMPV is currently unknown. Herein, an experimental mouse model was used to investigate the interplay between RSV and hMPV infections and IFN-alpha in the airways. RSV-infected BALB/c mice treated intranasally with either poly-ICLC, a potent inducer of IFN-alpha, or directly with recombinant IFN-alpha showed significantly reduced lung viral titers, inflammation, and clinical disease than untreated controls. However, RSV was significantly less sensitive to the antiviral activity of IFN-alpha than hMPV. Similarly, when the ability to directly induce IFN-alpha production was assessed, RSV was clearly a weaker inducer of IFN-alpha than hMPV, as shown by both kinetics and the absolute amount of IFN-alpha secreted into the bronchoalveolar lavage. To further investigate the putative inhibitory effect of these viruses on IFN-alpha production, mice were infected for 48 h prior to treatment with poly-ICLC or a specific Toll-like receptor 9 ligand, CpG oligodeoxynucleotides. Strikingly, both poly-ICLC- and CpG-mediated IFN-alpha production was abrogated by either RSV or MPV infection. These results suggest that a complex interplay between virus-specific and host-mediated responses regulates IFN-alpha in the lung during infection by members of the Pneumovirinae family.

Diagnostic utility of cell cycle and apoptosis regulatory proteins in verrucous squamous carcinoma

A major problem in the diagnosis of verrucous squamous cell carcinoma is the lack of readily reproducible objective criteria for distinguishing this malignant lesion from reactive epithelial hyperplasia. Both lesions are characterized by thickened (well-differentiated) squamous epithelium without cellular atypia and subjacent stroma densely infiltrated by lymphocytes and plasma cells. This study was carried out to evaluate the use of cell cycle and apoptosis-related regulatory proteins in the diagnosis of verrucous carcinoma. The study materials consisted of representative formalin-fixed and paraffin-embedded tissue blocks from 19 cases of verrucous carcinoma, 18 classic squamous cell carcinoma, and 14 squamous epithelial hyperplasia (acanthosis). The immunohistochemical expression of the following of cell cycle and apoptosis-related regulatory proteins was evaluated using avidin-biotin complex detection technique: p16, p21, p53, Ki67, and retinoblastoma gene product (RBGP) (also known as retinoblastoma protein [pRb]). Expression of Ki67 was detected only in the single basal layer of the epithelium in all 14 cases of acanthosis. In verrucous carcinoma, Ki67 was detected in basal and suprabasal cells in the lower third of the neoplastic epithelium in 19 of 19 cases (100%). In neoplastic squamous epithelium with frankly invasive squamous cell carcinoma, Ki67 was diffusely expressed throughout the entire thickness of the epithelium as well as in the underlying invasive tumor nests. The pattern of p53 expression was similar to that of Ki67 in all the experimental groups, with a Pearson correlation coefficient of 0.98. In addition, immunohistochemical expression of p53 in the hyperplastic squamous epithelium was very weak, in contrast to the more intense immunoreactivity observed in verrucous carcinoma and classic squamous cell carcinoma. There was an overlapping in the expression of p16, p21, and RGBP in all the experimental groups, being present in more than half the thickness of the epithelium in 50% to 100% cases in each study group. We therefore conclude that the pattern of Ki67 and p53 expression in verrucous carcinoma is readily reproducible and distinctly different from that observed in epithelial hyperplasia and that seen in invasive squamous cell carcinoma. Thus Ki67, and p53 immunostains are reliable adjuncts that may be helpful in resolving diagnostic problems associated with verrucous carcinoma.

Epithelial cells and their neighbors I. Role of intestinal myofibroblasts in development, repair, and cancer

Intestinal myofibroblasts are alpha-smooth muscle actin-positive stromal cells that exist as a syncytium with fibroblasts and mural cells in the lamina propria of the gut. Through expression and secretion of cytokines, chemokines, growth factors, prostaglandins, and basal lamina/extracellular matrix molecules, as well as expression of adhesion molecules and receptors for many of the same soluble factors and matrix, myofibroblasts mediate information flow between the epithelium and the mesenchymal elements of the lamina propria. With the use of these factors and receptors, they play a fundamental role in intestinal organogenesis and in the repair of wounding or disease. Intestinal neoplasms enlist and conscript myofibroblast factors and matrix molecules to promote neoplastic growth, carcinoma invasion, and distant metastases.

Frequent activation of the hedgehog pathway in advanced gastric adenocarcinomas

The hedgehog pathway plays a critical role in the development of the foregut. Recent studies indicate that the hedgehog pathway activation occurs in the stomach and other gastrointestinal cancers. However, the association of hedgehog pathway activation with tumor stage, differentiation and tumor subtype is not well documented. Here, we report our findings that the elevated expression of hedgehog target genes human patched gene 1 (PTCH1) or Gli1 occurs in 63 of the 99 primary gastric cancers. Activation of the hedgehog pathway is associated with poorly differentiated and more aggressive tumors. The sonic hedgehog (Shh) transcript is localized to the cancer tissue, whereas expression of Gli1 and PTCH1 is observed both in the cancer and in the surrounding stroma. Treatment of gastric cancer cells with KAAD-cyclopamine, a hedgehog signaling inhibitor, decreases expression of Gli1 and PTCH1, resulting in cell growth inhibition and apoptosis. Overexpression of Gli1 under the control of the cytomegalovirus (CMV) promoter renders these cells resistant to cyclopamine-induced apoptosis. Thus, our analysis of in vivo tissues indicates that the hedgehog pathway is frequently activated in advanced gastric adenocarcinomas; our in vitro studies suggest that hedgehog signaling contributes to gastric cancer cell growth. These data predict that targeted inhibition of the hedgehog pathway may be effective in the prevention and treatment of advanced gastric adenocarcinomas.

Class II MHC-expressing myofibroblasts play a role in the immunopathogenesis associated with staphylococcal enterotoxins

Food poisoning due to staphylococcal enterotoxins (SEs) affects hundreds of thousands of people each year. Little is known about how SEs initiate immune responses and cause pathogenesis. Here, we demonstrate that cultured human intestinal myofibroblasts (IMFs) bind SEs in an MHC class II-dependent fashion. IMFs respond to SE exposure with increased secretion of IL-6, IL-8, and TNF-alpha. A significant proliferative T cell response was observed when MHC class II-expressing IMFs were pulsed with SEA and cocultured with human CD4(+) T cells. In conclusion, our findings support the hypothesis that IMFs may play an important role in pathology associated with staphlococcocal enterotoxigenic disease.

Intestinal myofibroblasts and immune tolerance

Stromal cells, such as myofibroblasts and fibroblasts, represent a significant fraction of MHC class II-positive cells in the normal human colonic lamina propria, suggesting they may play an important role in CD4(+) T cell regulation in a tolerogenic environment. The aim of this study was to examine whether human colonic myofibroblasts (CMFs) phenotypically and functionally resemble conventional antigen-presenting cells (APCs). Our results support the hypothesis that intestinal myofibroblasts are a novel, nonprofessional APC phenotype important in modulating mucosal T cell responses. Given their strategic location, we propose that intestinal myofibroblasts play a critical role in mediating tolerance to luminal antigens.

Metastasis of Small Cell Carcinoma of Lung Into an Ovarian Mucinous Neoplasm: Immunohistochemistry as a Useful Ancillary Technique for Diagnosis and Classification of Rare Tumors

The authors report the first case of ovarian mucinous adenocarcinoma with metastasis from a synchronous small cell neuroendocrine carcinoma of the lung. A 62-year-old white woman presented with weight loss and increased abdominal girth. She was found to have a large, complex cystic mass in the pelvis, and during the staging evaluation, a large, right pulmonary hilar mass was detected. Bronchial brushing as well as transbronchial fine-needle aspiration was diagnostic of small cell carcinoma. The patient received 3 cycles of chemotherapy with carboplatin and subsequently underwent a supracervical hysterectomy and bilateral salpingo-oophorectomy. A large, multiloculated cystic mass was found arising from the right ovary. Microscopic examination disclosed a mucinous neoplasm with both mucinous cystadenoma and mucinous papillary adenocarcinoma components. A microscopic focus of cells with "atypical" cytomorphologic features was detected within the mucinous neoplasm. Immunohistochemistry showed that group of cells to be positive for thyroid transcription factor 1 and chromogranin, confirming them to be metastasis from the pulmonary small cell neuroendocrine carcinoma. This case, in addition to being the first reported case of such metastasis, also highlights the diagnostic utility of immunohistochemistry as a reliable and very useful ancillary technique for the diagnosis of neoplasms with unusual clinical and/or histomorphologic presentations. The clinical and prognostic implications are also discussed.

Subepithelial myofibroblasts express cyclooxygenase-2 in colorectal tubular adenomas

PURPOSE

Recent data support the hypothesis that the inducible isoform of cyclooxygenase (COX-2) plays a role in the early stages of colonic carcinogenesis and that nonsteroidal anti-inflammatory drugs (NSAIDs) retard the development of colon cancer by modulating COX-2. However, the cell types responsible for producing COX-2 in colorectal adenomas remain a subject of controversy.

EXPERIMENTAL DESIGN

COX-2 expression in normal colonic mucosa (n = 50), hyperplastic polyps (n = 43), sporadic adenomas (n = 67), and invasive colonic adenocarcinoma (n = 39) was studied in formalin-fixed and paraffin-embedded tissue sections from endoscopy biopsy and colonic resection specimens. Immunohistochemistry (avidin-biotin complex technique with double immunolabeling) was used to identify the phenotypes of COX-2-producing cells.

RESULTS

In colorectal adenomas, increased expression of COX-2 was detected and localized to alpha smooth muscle actin ( proportional, variant SMA)-positive subepithelial stromal cells (myofibroblasts) in the periluminal region of the lamina propria in 63 (94%) of 67 cases. In contrast, in normal colonic mucosa and in hyperplastic polyps with intact epithelium, COX-2 expression was found only in macrophages and endothelial cells. In areas in which the surface epithelium was ulcerated in normal mucosa as well as hyperplastic or neoplastic polyps, COX-2 expression was increased in granulation tissue (and present in macrophages, endothelium, and myofibroblasts). In invasive carcinoma, COX-2 expression in myofibroblasts was limited to the adenomatous portion of the tumor and was detected in 62% of cases (n = 39). In addition, focal expression of COX-2 by malignant epithelial cells was observed in 23% of invasive adenocarcinoma.

CONCLUSIONS

These results show that increased COX-2 expression in sporadic adenoma of the colon is common and is localized specifically to subepithelial intestinal myofibroblasts. These findings further support the hypothesis that myofibroblasts are important target cells for NSAID-mediated chemoprevention of colorectal cancer.

Angiosarcoma of the of scalp with calvarium involvement in a 50-year-old African-American man

BACKGROUND

Angiosarcoma of the scalp is a rare, aggressive, and deadly cancer that affects mainly elderly Caucasian men.

OBJECTIVES

The insidious and masquerading presentation of angiosarcoma poses enormous diagnostic challenges for primary care providers.

PATIENTS/METHODS

We present a case of a 50-year-old black man referred for evaluation of a 3.7-cm-x-5.4-cm ulcerated, fluctuant scalp lesion that had failed to respond to different antibiotics and proper wound care.

RESULTS

Surgical excision and subsequent histopathology revealed angiosarcoma.

CONCLUSIONS

This case report highlights the importance of high index of suspicion for early diagnosis of cancerous lesions in wounds and stresses the need to include angiosarcoma in the differential diagnosis for all face and scalp lesions, as early detection may save lives. A comprehensive literature review is also presented.

Immunohistochemical Expression of Cyclooxygenase-2 in Normal Kidneys

Cyclooxygenase (COX)-2, the recently described inducible form ofcyclooxygenase, has been shown to be responsible for the inflammatory and tumorigenic effects of prostaglandins; hence the development and expanding clinical use of COX-2 selective inhibitors termed super aspirins. These pharmacologic agents block COX-2 without abrogating the desired physiologic roles of the constitutively expressed isoform COX-1. Therefore, they are now used in place of nonselective COX inhibitors in patients who require prolonged use of nonsteroidal anti-inflammatory agents. However, there are sporadic reports of COX-2-related nephrotoxicity, and the mechanism of this adverse reaction is not known. Also, the pattern of in situ expression of COX-2 in the human kidney is not known. We therefore studied the immunohistochemical expression of COX-2 in normal kidneys obtained from 53 consecutive total nephrectomy specimens. COX-2 immunohistochemistry was performed using affinity purified polyclonal murine antibody and avidin-biotin detection method with citrate antigen retrieval. Also, to localize COX-2 expression to specific cell types, double immunolabeling was performed using avidin-biotin (for COX-2 detection) and alkaline phosphatase (for detection of alpha-smooth muscle actin or factor VIII related antigen). In the cortex, COX-2 was found to be constitutively expressed in the endothelial cells of arteries, arterioles, and glomeruli in all 53 kidneys. COX-2 expression was also found in the cortical thick ascending limb of the loop of Henle (medullary rays and macula densa) in 50 of 53 cases. In the medulla, COX-2 expression was detected in the endothelial lining of the vasa recta in 52 cases and in the collecting ducts in 5 cases. These data show significant constitutive expression of COX-2 in normal kidney and underscore the need for caution in the use of COX-2 selective inhibitors, especially on a long-term basis.

Aspirin-Mediated COX-2 Transcript Stabilization via Sustained p38 Activation in Human Intestinal Myofibroblasts

Acetylsalicylic acid (aspirin) is a cyclooxygenase (COX) inhibitor, yet some of its therapeutic effects are thought to derive from mechanisms unrelated to prostaglandin synthesis inhibition. In human intestinal myofibroblasts, aspirin, at therapeutic doses, had the unexpected effect of inducing prolonged COX-2 expression. This induction was especially pronounced when cells were treated with interleukin-1alpha (IL-1) plus aspirin for 24 h. Sodium salicylate, a poor COX inhibitor, likewise enhanced IL-1-mediated COX-2 gene expression whereas 5-aminosalicylic acid (5-ASA) or indomethacin had no effect. The COX-2 transcriptional rate, measured by nuclear runoff analysis and heterogeneous nuclear RNA reverse transcription-polymerase chain reaction, was only modestly elevated by aspirin treatment. In contrast, aspirin treatment dramatically stabilized the COX-2 message. The COX-2 mRNA half-life in IL-1 treated cells was 1 h and was increased in excess of 5 h in IL-1 + aspirin-treated cells. Phosphorylation of p38 MAPK was enhanced in aspirin-treated cells (but not in cells treated with 5-ASA or indomethacin) for up to 24 h after treatment. Inhibition of p38 activity negated aspirin-mediated COX-2 mRNA stabilization and the resultant increase in COX-2 mRNA and protein levels. The modest transcriptional response seen in aspirin treated cells was also abolished by p38 inhibition. We conclude that aspirin enhances COX-2 expression via sustained activation of p38, which results in prolonged stabilization of the COX-2 message and a slightly elevated transcription rate. Aspirin also enhanced steady-state mRNA levels of other IL-1 modulated genes (IL-1beta, IL-6, groalpha, and TNFalpha) that are likewise regulated at the level of message stability via p38 activation.

IL-1alpha-induced COX-2 expression in human intestinal myofibroblasts is dependent on a PKCzeta-ROS pathway

BACKGROUND & AIMS

Intestinal myofibroblasts (IMFs) express cyclooxygenase 2 (COX-2) early on in polyp progression and respond to pro-inflammatory cytokines. Interleukin (IL)-1alpha induces COX-2 expression in IMF via mitogen-activated protein kinase (MAPK), protein kinase C (PKC), and nuclear factor kappa B (NF-kappaB)-dependent pathways. Because NF-kappaB activity can be mediated by PKC activation and reactive oxygen species (ROS) generation, we examined the relationship of these pathways to IL-1alpha-induced COX-2 expression.

METHODS

The effects of specific PKC inhibitors and antioxidants on PKC activation, ROS generation, and COX-2 expression were studied.

RESULTS

Immunoprecipitation/kinase (IPK) analysis showed that IL-1alpha increased PKC alpha, delta, and zeta activity 4.5-, 3.1-, and 2.6-fold, respectively, within 5 minutes. Single-cell fluorescence microscopy of 2',7'-dichlorofluorescin diacetate (DCF)-loaded cells showed that IL-1alpha increased ROS levels 2-fold within 15 minutes and this increase was inhibited by 10 micromol/L bisindolylymaleimide I (BIS), a pan-specific PKC inhibitor that also inhibits COX-2 expression. Chelerythrine chloride (CC) (0.5 micromol/L) inhibited classic and novel PKC activity, but not PKCzeta, and enhanced IL-1alpha-mediated ROS generation 4.0-fold and COX-2 expression 1.8-fold. The use of a PKCzeta pseudosubstrate prevented IL-1 from increasing ROS greater than control levels and abolished IL-1alpha-induced COX-2 expression. Small inhibitory RNA (siRNA) for PKCzeta confirmed its role in COX-2 expression. Antioxidants inhibited ROS generation and diminished IL-1alpha-induced COX-2 expression by 80%, without affecting PKC activation. Neither the PKC inhibitors nor the antioxidants prevented NF-kappaB-mediated transcription as determined by reporter gene analysis.

CONCLUSIONS

PKCzeta and threshold ROS generation are critical for IL-1alpha-induced COX-2 expression and act concomitantly with NF-kappaB translocation in IMF.

Effect of decalcification on the immunohistochemical expression of ABH blood group isoantigens

Immunohistochemical stains for ABH blood group antigens were recently shown to be useful ancillary tools for sorting out specimen mix-ups in surgical pathology, irrespective of the fixatives used. However, the effects of decalcification on the expression of these antigens are not known. Therefore, to examine the validity of using ABH blood group immunohistochemistry in decalcified tissues, we studied the immunohistochemical expression of ABH blood group antigens in B5-fixed, decalcified, paraffin-embedded archival bone marrow specimens from 43 consecutive patients (13 blood group A, 6 group B, 20 group O, and 4 group AB). Immunohistochemical staining for A, B, and H blood group antigens was performed with monoclonal antibodies and an avidin-biotin detection method with citrate antigen retrieval. The results of immunohistochemistry were correlated with patients' blood groups as determined by serology. Immunohistochemical expression of the A and B blood group antigens with good staining intensity was detected in erythrocytes and endothelial cells. The immunoreactivity for H blood group antigen was attenuated by the decalcification process and could not be enhanced with citrate antigen retrieval. However, in all 43 cases, the A and B antigen staining pattern was concordant with patients' blood groups as determined with serology. These results show that decalcification does not have adverse effects on immunohistochemical expression of the A and B blood group antigens in tissue sections but may nullify the expression of H isoantigen. However, based on A and B immunoreactivity patterns, immunostaining for ABH blood group antigens can be helpful in resolving problems of specimen mix-ups and tissue floaters in decalcified specimens.

Effect of tissue fixatives on the immunohistochemical expression of ABH blood group isoantigens

Immunohistochemical analysis of ABH blood group isoantigens has been shown to be a useful ancillary technique for resolving problems associated with specimen mix-ups in the daily practice of surgical pathology. However, the effects of different fixatives on the expression of these antigens in paraffin-embedded tissues are not known. Therefore, the effects of seven different fixatives on the immunohistochemical expression of ABH blood group isoantigens were studied in tissues from several organs. The following fixatives were used: acetone, 70% ethanol, B5, Bouin, Carnoy, methanol, and 10% formalin. After fixation for 6, 12, and 72 hours, the tissue blocks were embedded in paraffin, and immunohistochemistry was performed on 4 microm-thick tissue sections using monoclonal antibodies to blood group isoantigens (A, B, and H) and the avidin-biotin detection method. Also, immunostaining was performed on step tissue sections with and without antigen retrieval using citrate buffer at pH 6.0. The expression of the blood group isoantigens was concordant with the blood group of the patient in all the cases studied, irrespective of the fixative and time of fixation. However, in the absence of antigen retrieval, the intensity of the staining reaction was diminished. These results showed that irrespective of the fixative used, immunohistochemical staining of paraffin-embedded tissue sections with ABH blood group antibodies is a rapid, reliable, and cost-effective method for sorting out interpretative problems of tissue contaminants (floaters) and specimen mix-ups in surgical pathology.

Immunohistochemical study of myofibroblasts in normal colonic mucosa, hyperplastic polyps, and adenomatous colorectal polyps

CONTEXT

Myofibroblasts are distinct cells with characteristics of both smooth muscle cells and fibroblasts. Through their ability to secrete cytokines, chemokines, prostaglandins, growth factors, and matrix components, they are thought to play critical roles in inflammation, growth, repair, and neoplasia.

OBJECTIVE

The goal of this study was to identify the distinct cell populations of the lamina propria of normal colon and colorectal polyps.

DESIGN

We studied the expression of alpha-smooth muscle actin (alphaSMA), smooth muscle myosin (SMM), desmin, vimentin, and c-kit by intestinal mesenchymal (stromal) cells in the normal colonic mucosa (n = 5), as well as in hyperplastic polyps (n = 5), sporadic colorectal adenomas (n = 47), and adenomas from patients with familial polyposis (n = 36).

RESULTS

In the normal colonic mucosa, the pericryptal stromal cells were alphaSMA+, SMM+, desmin-, and vimentin+, defining them as myofibroblasts. In contrast, cells of the muscularis mucosae were alphaSMA+, SMM+, desmin+, and vimentin-, defining them as smooth muscle cells. alpha-Smooth muscle actin also highlighted direct connections between the muscularis mucosae and the pericryptal myofibroblasts, and vimentin immunostaining showed a network of connections between the alphaSMA+ pericryptal myofibroblasts and the alphaSMA- fibroblasts in the interstitium. In all hyperplastic polyps and adenomatous polyps, the interstitial stromal cells (fibroblasts) now also express alphaSMA and form a syncytium of alphaSMA+ networklike connections throughout the lamina propria. Stromal cells of sporadic adenomas demonstrated the same immunohistochemical staining characteristics displayed by adenomas from patients with familial polyposis and by hyperplastic polyps. Conclusions.-These findings indicate that in normal colon, alphaSMA- fibroblasts are the predominant cell type in the lamina propria. However, the pericryptal (subepithelial) stromal cells are a distinct cell type (alphaSMA+ myofibroblast) that is immunophenotypically different from muscularis mucosae smooth muscle cells and are connected to the interstitial, nonpericryptal fibroblasts with which they exist as a network throughout the lamina propria of the normal colon. Furthermore, in both hyperplastic and neoplastic polyps, there are changes in nonpericryptal fibroblasts from vimentin+, alphaSMA-, and SMM- to vimentin+, alphaSMA+, and SMM+; thus, the interstitial fibroblasts are replaced by myofibroblasts. The factors that cause these changes and the origin of the myofibroblasts need to be determined to clarify the biology of colorectal tumorigenesis.

Immunohistochemical study of myofibroblasts in normal colonic mucosa, hyperplastic polyps, and adenomatous colorectal polyps

CONTEXT

Myofibroblasts are distinct cells with characteristics of both smooth muscle cells and fibroblasts. Through their ability to secrete cytokines, chemokines, prostaglandins, growth factors, and matrix components, they are thought to play critical roles in inflammation, growth, repair, and neoplasia.

OBJECTIVE

The goal of this study was to identify the distinct cell populations of the lamina propria of normal colon and colorectal polyps.

DESIGN

We studied the expression of alpha-smooth muscle actin (alphaSMA), smooth muscle myosin (SMM), desmin, vimentin, and c-kit by intestinal mesenchymal (stromal) cells in the normal colonic mucosa (n = 5), as well as in hyperplastic polyps (n = 5), sporadic colorectal adenomas (n = 47), and adenomas from patients with familial polyposis (n = 36).

RESULTS

In the normal colonic mucosa, the pericryptal stromal cells were alphaSMA+, SMM+, desmin-, and vimentin+, defining them as myofibroblasts. In contrast, cells of the muscularis mucosae were alphaSMA+, SMM+, desmin+, and vimentin-, defining them as smooth muscle cells. alpha-Smooth muscle actin also highlighted direct connections between the muscularis mucosae and the pericryptal myofibroblasts, and vimentin immunostaining showed a network of connections between the alphaSMA+ pericryptal myofibroblasts and the alphaSMA- fibroblasts in the interstitium. In all hyperplastic polyps and adenomatous polyps, the interstitial stromal cells (fibroblasts) now also express alphaSMA and form a syncytium of alphaSMA+ networklike connections throughout the lamina propria. Stromal cells of sporadic adenomas demonstrated the same immunohistochemical staining characteristics displayed by adenomas from patients with familial polyposis and by hyperplastic polyps. Conclusions.-These findings indicate that in normal colon, alphaSMA- fibroblasts are the predominant cell type in the lamina propria. However, the pericryptal (subepithelial) stromal cells are a distinct cell type (alphaSMA+ myofibroblast) that is immunophenotypically different from muscularis mucosae smooth muscle cells and are connected to the interstitial, nonpericryptal fibroblasts with which they exist as a network throughout the lamina propria of the normal colon. Furthermore, in both hyperplastic and neoplastic polyps, there are changes in nonpericryptal fibroblasts from vimentin+, alphaSMA-, and SMM- to vimentin+, alphaSMA+, and SMM+; thus, the interstitial fibroblasts are replaced by myofibroblasts. The factors that cause these changes and the origin of the myofibroblasts need to be determined to clarify the biology of colorectal tumorigenesis.

Immunohistochemical study of myofibroblasts in normal colonic mucosa, hyperplastic polyps, and adenomatous colorectal polyps

CONTEXT

Myofibroblasts are distinct cells with characteristics of both smooth muscle cells and fibroblasts. Through their ability to secrete cytokines, chemokines, prostaglandins, growth factors, and matrix components, they are thought to play critical roles in inflammation, growth, repair, and neoplasia.

OBJECTIVE

The goal of this study was to identify the distinct cell populations of the lamina propria of normal colon and colorectal polyps.

DESIGN

We studied the expression of alpha-smooth muscle actin (alphaSMA), smooth muscle myosin (SMM), desmin, vimentin, and c-kit by intestinal mesenchymal (stromal) cells in the normal colonic mucosa (n = 5), as well as in hyperplastic polyps (n = 5), sporadic colorectal adenomas (n = 47), and adenomas from patients with familial polyposis (n = 36).

RESULTS

In the normal colonic mucosa, the pericryptal stromal cells were alphaSMA+, SMM+, desmin-, and vimentin+, defining them as myofibroblasts. In contrast, cells of the muscularis mucosae were alphaSMA+, SMM+, desmin+, and vimentin-, defining them as smooth muscle cells. alpha-Smooth muscle actin also highlighted direct connections between the muscularis mucosae and the pericryptal myofibroblasts, and vimentin immunostaining showed a network of connections between the alphaSMA+ pericryptal myofibroblasts and the alphaSMA- fibroblasts in the interstitium. In all hyperplastic polyps and adenomatous polyps, the interstitial stromal cells (fibroblasts) now also express alphaSMA and form a syncytium of alphaSMA+ networklike connections throughout the lamina propria. Stromal cells of sporadic adenomas demonstrated the same immunohistochemical staining characteristics displayed by adenomas from patients with familial polyposis and by hyperplastic polyps. Conclusions.-These findings indicate that in normal colon, alphaSMA- fibroblasts are the predominant cell type in the lamina propria. However, the pericryptal (subepithelial) stromal cells are a distinct cell type (alphaSMA+ myofibroblast) that is immunophenotypically different from muscularis mucosae smooth muscle cells and are connected to the interstitial, nonpericryptal fibroblasts with which they exist as a network throughout the lamina propria of the normal colon. Furthermore, in both hyperplastic and neoplastic polyps, there are changes in nonpericryptal fibroblasts from vimentin+, alphaSMA-, and SMM- to vimentin+, alphaSMA+, and SMM+; thus, the interstitial fibroblasts are replaced by myofibroblasts. The factors that cause these changes and the origin of the myofibroblasts need to be determined to clarify the biology of colorectal tumorigenesis.

Immunohistochemical study of thyroid transcription factor-1 and HER2/neu in non-small cell lung cancer: strong thyroid transcription factor-1 expression predicts better survival

The relationship of thyroid transcription factor-1 (TTF-1) and HER2/neu expression in non-small cell lung cancer (NSCLC) with multiple parameters including survival were examined. Patients with primary NSCLC who had surgical resection and follow-up of at least 5 years were included in the study. There were 57 patients (38 men and 19 women), 44 to 75 years old (median age, 61 years); 28 patients had adenocarcinoma (AD) and 29 had squamous cell carcinoma. Tumors were examined for TTF-1 and HER2/neu expression using formalin-fixed, paraffin-embedded tissue. Clinical and follow-up data were obtained from the hospital records and Cancer Center database. Representative tumor sections were stained using standard immunohistochemical technique and commercial antibodies for TTF-1 (clone 8G7G3/1, Dako) and HER2/neu (polyclonal, Dako). Tumors were graded as negative (<5%), weak positive (5-49%), and strong positive (>50%), based on the percentage of positively stained tumor cells. Statistical analyses were performed using log-rank test, Pearson and Spearman correlations, and Kaplan-Meier survival curves. TTF-1 expression was seen in 45.6% of all tumors (80% of ADs and 14% of squamous cell carcinomas). Eighteen patients with tumors showing strong TTF-1 expression had significantly better survival compared with the 39 patients whose tumors showed negative or weak TTF-1 expression, although many more of the higher stage AD had strong TTF-1 staining than stage I AD. The TTF-1 expression did not correlate with tumor differentiation and was considered an independent predictor of survival. Seventeen of the 18 tumors with strong TTF-1 expression were ADs. Only eight of 57 (17%) tumors showed HER2/neu expression; seven of these eight were ADs. Although HER2/neu expression and survival did not show correlation, the majority of those ADs with weak or strong HER2/neu staining also had strong TTF-1 staining, were mostly stage I tumors. and had overall longer survival. All patients with stage I disease showed better 5-year survival compared with those with stages II and III. Hispanic patients had significantly worse survival compared with Caucasians and African Americans. The results of this study suggest that strong expression of TTF-1 is an independent predictor of better survival and may be a useful prognostic tool for evaluation of patients with NSCLC.

Regulation of COX-2 expression in human intestinal myofibroblasts: mechanisms of IL-1-mediated induction

Elevated mucosal interleukin-1 (IL-1) levels are frequently seen during acute and chronic intestinal inflammation, and IL-1 neutralization lessens the severity of inflammation. One major effect of IL-1 is the increased release of eicosanoid mediators via induction of cyclooxygenase-2 (COX-2). One site of COX-2-derived prostaglandin synthesis during acute and chronic intestinal inflammation is the intestinal myofibroblast. COX-2 expression has also been documented in these cells in colonic neoplasms. Thus an understanding of the regulation of COX-2 expression in human intestinal myofibroblasts is important. As an initial step toward this goal we have characterized IL-1alpha signaling pathways that induce COX-2 expression in cultured human intestinal myofibroblasts. IL-1 treatment resulted in a dramatic transcriptional induction of COX-2 gene expression. Activation of nuclear factor-kappaB (NF-kappaB), extracellular signal-regulated protein kinase (ERK), p38, and protein kinase C (PKC) signaling pathways was each necessary for optimal COX-2 induction. In contrast to what occurs in other cell types, including other myofibroblasts such as renal mesangial cells, PKC inhibition did not prevent IL-1-induced NF-kappaB or mitogen activated protein kinase/ stress-activated protein kinase activation, suggesting a novel role for PKC isoforms during this process. The stimulatory effects of PKC, NF-kappaB, ERK-1/2, and presumably c-Jun NH(2)-terminal kinase activation were exerted at the transcriptional level, whereas p38 activation resulted in increased stability of the COX-2 message. We conclude that, in intestinal myofibroblasts, IL-1-mediated induction of COX-2 expression is a complex process that requires input from multiple signaling pathways. Each parallel pathway acts in relative autonomy, the sum of their actions culminating in a dramatic increase in COX-2 transcription and message stability.

Fine needle aspiration cytology of hepatobiliary cystadenoma with mesenchymal stroma

BACKGROUND

Hepatobiliary cystadenomas (HBCs) with mesenchymal stroma (MS) are rare cystic neoplasms occurring exclusively in women. Hepatobiliary cystadenoma consists of a mucin-producing cyst lining epithelium underlined by a dense MS cell layer. In the current study, the authors review the fine needle aspiration cytology of HBC with MS and identify characteristic cytologic features that suggest such an uncommon neoplasm on aspirates.

METHODS

A search of the histopathology files at the University of Texas Medical Branch at Galveston for the interval of January 1992 through December 2000 yielded four cases of HBC having both cytologic and histologic specimens. The cytologic features of the aspirates were reviewed and correlated with the clinical history, radiologic findings, and the histopathology of the excised specimens.

RESULTS

All four patients were middle-aged women (mean age, 48.5 years) who presented with epigastric pain radiating to the back, due to large cystic lesions in the right liver lobe (three patients) or the left liver lobe (one patient). Aspiration cytology revealed chronic inflammatory exudate in all cases, along with occasional aggregates of bland, cuboidal-columnar epithelial cells (in three cases), which rarely arranged in papillary clusters. No significant atypia, evidence of malignancy, or MS cells were identified on the aspirates. HBC with MS was confirmed histologically on the excised specimens in all cases.

CONCLUSIONS

By ensuring adequate sampling and correlating with consistent clinical and radiologic findings, a diagnosis of HBC or cystic hepatobiliary neoplasm can be suggested on the basis of aspiration cytology.

Down-regulation of Fas expression in the lymph nodes of patients infected with human immunodeficiency virus

CONTEXT

The mechanism by which human immunodeficiency virus 1 (HIV-1) infection causes increased rates of apoptosis and gradual chronic depletion of CD4(+) T lymphocytes in patients infected with HIV-1 is not known. Findings from in vitro culture studies and analysis of mononuclear cells in the peripheral blood of HIV-infected patients have led to the hypothesis that abnormal expression and/or interaction of Fas and Fas ligand (FasL) may play significant roles in the derangement of homeostasis of CD4(+) lymphocytes in patients infected with HIV-1.

OBJECTIVE

To determine the in situ expression of Fas and FasL in the lymph nodes of patients infected with HIV-1.

DESIGN

Immunohistochemical expression of Fas and FasL was studied in the lymph node biopsy specimens from 20 patients infected with HIV-1. As controls, we also studied 120 lymph nodes from 28 HIV-1-seronegative patients with reactive lymphadenopathy.

RESULTS

In the reactive lymph nodes of seronegative patients, expression of Fas was diffuse in the germinal centers and also in immunoblast-like cells in the T-cell regions. In the lymph nodes of patients infected with HIV, there was a consistent remarkable decrease in Fas expression in 12 of 20 patients and a total lack of Fas expression in the remaining 8 patients. Expression of FasL was comparable in both patient groups.

CONCLUSIONS

There is marked down-regulation of Fas in the lymph nodes of HIV-infected patients, a sharp contrast to what occurs in circulating mononuclear cells in the peripheral blood of these patients. These results indicate the need for further studies of this molecular event for possible therapeutic intervention based on reconstitution of Fas and/or FasL activity in the treatment of HIV infection.

Myelophthisis as a solitary manifestation of failure from rectal carcinoma. A Batson phenomenon?

Rectal carcinoma is uncommonly associated with systemic metastases in the absence of liver metastases, reflecting the predilection for spread via the portal system. Occasionally, isolated lung metastases are seen, which are usually attributed to spread via the portosystemic anastomoses in the distal rectum. However, myelophthisis is an unreported complication of rectal cancer as an isolated form of systemic failure. We present a case of fatal myelophthisis associated with otherwise localized rectal carcinoma secondary to metastatic rectal cancer. This observation led to the hypothesis that spread to the bone marrow occurred via a "third circulation," the Batson plexus, a network of deep pelvic veins with rich anastomoses to the vertebral plexus.

Pyogenic spondylodiskitis: a radiologic/pathologic and culture correlation study

BACKGROUND

Intervertebral disk tissue is resistant to hematogenous infection because of its avascularity. However, spondylodiskitis is being diagnosed with increasing frequency because of advancement in magnetic resonance imaging technology. There is a dearth of information regarding the bacteriology, histomorphologic features, and radiopathologic correlation of spondylodiskitis.

DESIGN

The study population consisted of 20 patients diagnosed as having spondylodiskitis by magnetic resonance imaging with and without gadolinium 67 enhancement and bone scans with technetium Tc 99m or gallium citrate Ga 67. Twenty-seven biopsy and debridement specimens were obtained from these patients. The specimens were cultured for microorganisms and also processed for histopathologic testing. Tissue sections were examined with hematoxylin-eosin and stains for infectious agents (Gomori's methenamine-silver, Gram, and Ziehl-Neelsen stains).

RESULTS

Where intervertebral disk tissue was present (23 of 27 cases), the morphologic changes included vascularization (with or without granulation tissue), myxoid degeneration, and necrosis. Chronic osteomyelitis was present in all 27 specimens and was associated with acute osteomyelitis in 7 cases (25%). Twenty-one of 27 cases had positive culture results (mostly pyogenic bacteria), but special stains revealed microorganisms in sections of the disk in only 4 cases (3 cases with gram-positive cocci and 1 with yeast consistent with Blastomyces). Florid acute inflammation was present in all the 4 cases.

CONCLUSION

Histopathologic features of acute spondylodiskitis include vascular proliferation, myxoid degeneration, and necrosis of the disk tissue with adjacent chronic osteomyelitis. Acute inflammation is variable and when florid is usually associated with identifiable organisms on histologic examination. At biopsy, tissue should be submitted for culture, since culture has a high sensitivity and specificity for detecting the etiologic organism.

Acrometastasis in renal cell carcinoma

Acrometastasis is rare and may occur as the primary manifestation of an occult malignant tumor. Clinically, it may mimic benign osteoarthritic diseases, thus resulting in misdiagnosis and improper treatment. We describe a patient with renal cell carcinoma that presented itself as a case of chronic osteomyelitis after trauma to a finger. Such a lesion presents diagnostic challenges to both clinicians and histopathologists.

Tubulovillous adenoma of the urinary bladder

We report a case of vesical tubulovillous adenoma that occurred in a background of protracted chronic cystitis with intestinal-type glandular metaplasia and extensive cellular atypia (dysplasia) in the flat mucosa. Flow cytometry analysis showed DNA aneuploidy in the adenoma. Increased expression of the tumor suppresser gene, p53, and also of cellular proliferation markers (proliferating cell nuclear antigen and MIB-1) were detected in the villous adenoma and in the dysplastic regions of the flat metaplastic mucosa. These findings provide insight into the biology of intestinal metaplasia and also lend support to the theory of the chronic irritation-metaplasia-dysplasia-carcinoma sequence.

Testicular "tumor" of the adrenogenital syndrome: a case report of an unusual association with myelolipoma and seminoma in cryptorchidism

BACKGROUND

Males with congenital adrenal hyperplasia may develop bilateral testicular masses in early adult life. These are not malignant and generally regress with corticosteroid therapy. The authors report a case occurring in a 44-year-old man with associated seminoma and myelolipoma in an undescended testis.

METHODS

The testicular tumors were analyzed by histologic, flow cytometric, and ultrastructural techniques.

RESULTS

The tumors in both testes were comprised of polygonal cells with abundant granular eosinophilic cytoplasm, occasionally with brown (lipochrome) pigment and round nuclei of various sizes with prominent nucleoli. These cells were grouped into nodules by dense and sometimes thick fibrous trabeculae in the right testis. The areas corresponding to the fibrous trabeculae in the left (intraabdominal) testis were replaced by mixture of hematopoietic (myeloid) and fatty tissue in various proportions characteristic of myelolipoma. The left testis also had a well demarcated tumor that was diagnostic of seminoma. Electron microscopy demonstrated abundant smooth endoplasmic reticulum, a moderate number of mitochondria with tubulovesicular cristae, lipid droplets, and lipofuscin granules in the polygonal cells. No Reinke's crystals were observed. The patient received corticosteroids for his adrenocorticoid deficiency and also underwent external beam irradiation to the retroperitoneum for seminoma.

CONCLUSIONS

This case illustrates an unusual presentation of a testicular tumor in a patient with the adrenogenital syndrome as well as with myelolipoma and seminoma in a cryptorchid testis. The possibility of an associated neoplasm that could be potentially fatal should be considered whenever a testicular tumor of the adrenogenital syndrome continues to grow despite adequate hormonal treatment.

Sensitivity and specificity of triphenyl tetrazolium chloride in the gross diagnosis of acute myocardial infarcts

OBJECTIVE

Myocardial infarction is the most common cause of sudden death in the United States. However, the identification of early myocardial infarcts at necropsy is frequently difficult, since unequivocal gross changes of infarcts do not become apparent for 24 to 48 hours following myocardial ischemic injury. The use of dyes, such as nitro-blue tetrazolium and 2,3,5 triphenyl tetrazolium chloride (TTC), that identify the dehydrogenase-deficient infarcted myocardium has been shown, largely by animal studies, to be very helpful in the macroscopic diagnosis of such cases. Such animal studies could not be directly extrapolated to human autopsy studies, however, because of the assumption that autolysis may invalidate the histochemical assessment of myocardial enzymatic changes after death. This study was carried out to evaluate the sensitivity and specificity of TTC in the gross diagnosis of acute myocardial infarction in the human population.

DESIGN

The TTC stain reactions were correlated with histologic findings in the hearts of 638 consecutive adult autopsies.

RESULTS

Of the 638 hearts examined by TTC, 174 hearts stained positive for acute infarction; histology confirmed myocardial infarction in 140 hearts. Histologic examination revealed acute infarcts in 41 of the remaining 464 cases that had stained negatively with TTC. The use of TTC in the macroscopic diagnosis of acute myocardial infarcts in the human population was found to have a diagnostic sensitivity of 77.4% and a specificity of 92.6%. The predictive value of a positive test was 80.5%, and that of a negative test was 91.2%.

CONCLUSIONS

The overall diagnostic efficiency of the TTC test (ie, number of patients correctly identified) was 88%. These results show that the TTC test is a reliable, sensitive, and specific adjunct in the examination of the human heart at necropsy.

Recurrent massive hemothorax in Rendu-Osler-Weber syndrome

We report a case of Rendu-Osler-Weber syndrome, occurring as sudden death after two episodes of massive hemothorax. Autopsy revealed massive hemothorax resulting from spontaneous rupture of one of three subpleural arteriovenous malformations. Review of the patient's hospital records showed that she had had a massive spontaneous hemothorax 13 years earlier that was managed conservatively. This case emphasizes the importance of early therapeutic (surgical or radiologic) intervention in the treatment of pulmonary arteriovenous malformations.