Canine glioblastoma-derived extracellular vesicles as precise carriers for glioblastoma imaging: Targeting across the blood-brain barrier

The treatment of glioblastoma (GBM) faces significant challenges due to the difficulty of delivering drugs through the blood-brain barrier (BBB). Extracellular vesicles (EVs) have emerged as potential carriers for targeted drug delivery to brain tumors. However, their use and distribution in the presence of an intact BBB and their ability to target GBM tissue are still under investigation. This study explored the use of EVs for GBM targeting across the BBB. Canine plasma EVs from healthy dogs and dogs with glioma were isolated, characterized, and loaded with diagnostic agents. Biodistribution studies were conducted in healthy murine models and a novel intranasal model that preserved BBB integrity while initiating early-stage GBM growth. This model assessed EVs' potential for delivering the contrast agent gadoteric acid to intracranial tumors. Imaging techniques, such as bioluminescence and MRI, confirmed EVs' targeting and delivery capabilities thus revealing a selective accumulation of canine glioma-derived EVs in brain tissue under physiological conditions. In the model of brain tumor, MRI experiments demonstrated the ability of EVs to accumulate gadoteric acid within GBM to enhance contrast of the tumoral mass, even when BBB integrity is maintained. This study underscores the potential of EVs derived from glioma for the targeted delivery of drugs to glioblastoma. EVs from dogs with glioma showed capacity to traverse the BBB and selectively accumulate within the brain tumor. Overall, this research represents a foundation for the application of autologous EVs to precision glioblastoma treatment, addressing the challenge of BBB penetration and targeting specificity in brain cancer therapy.

The Potential of JAG Ligands as Therapeutic Targets and Predictive Biomarkers in Multiple Myeloma

The NOTCH ligands JAG1 and JAG2 have been correlated in vitro with multiple myeloma (MM) cell proliferation, drug resistance, self-renewal and a pathological crosstalk with the tumor microenvironment resulting in angiogenesis and osteoclastogenesis. These findings suggest that a therapeutic approach targeting JAG ligands might be helpful for the care of MM patients and lead us to explore the role of JAG1 and JAG2 in a MM in vivo model and primary patient samples. JAG1 and JAG2 protein expression represents a common feature in MM cell lines; therefore, we assessed their function through JAG1/2 conditional silencing in a MM xenograft model. We observed that JAG1 and JAG2 showed potential as therapeutic targets in MM, as their silencing resulted in a reduction in the tumor burden. Moreover, JAG1 and JAG2 protein expression in MM patients was positively correlated with the presence of MM cells in patients' bone marrow biopsies. Finally, taking advantage of the Multiple Myeloma Research Foundation (MMRF) CoMMpass global dataset, we showed that JAG2 gene expression level was a predictive biomarker associated with patients' overall survival and progression-free survival, independently from other main molecular or clinical features. Overall, these results strengthened the rationale for the development of a JAG1/2-tailored approach and the use of JAG2 as a predictive biomarker in MM.

Ceramide present in cholangiocarcinoma-derived extracellular vesicle induces a pro-inflammatory state in monocytes

Cholangiocarcinoma (CCA) is a rare cancer characterized by a global increasing incidence. Extracellular vesicles (EV) contribute to many of the hallmarks of cancer through transfer of their cargo molecules. The sphingolipid (SPL) profile of intrahepatic CCA (iCCA)-derived EVs was characterized by liquid chromatography-tandem mass spectrometry analysis. The effect of iCCA-derived EVs as mediators of inflammation was assessed on monocytes by flow cytometry. iCCA-derived EVs showed downregulation of all SPL species. Of note, poorly-differentiated iCCA-derived EVs showed a higher ceramide and dihydroceramide content compared with moderately-differentiated iCCA-derived EVs. Of note, higher dihydroceramide content was associated with vascular invasion. Cancer-derived EVs induced the release of pro-inflammatory cytokines in monocytes. Inhibition of synthesis of ceramide with Myriocin, a specific inhibitor of the serine palmitoyl transferase, reduced the pro-inflammatory activity of iCCA-derived EVs, demonstrating a role for ceramide as mediator of inflammation in iCCA. In conclusion, iCCA-derived EVs may promote iCCA progression by exporting the excess of pro-apoptotic and pro-inflammatory ceramides.

MICA/B-targeted antibody promotes NK cell-driven tumor immunity in patients with intrahepatic cholangiocarcinoma

The major histocompatibility complex-class I chain related proteins A and B (MICA/B) is upregulated because of cellular stress and MICA/B shedding by cancer cells causes escape from NKG2D recognition favoring the emergence of cancers. Cholangiocarcinoma (CCA) is a relatively rare, though increasingly prevalent, primary liver cancer characterized by a late clinical presentation and a dismal prognosis. We explored the NKG2D-MICA/B axis in NK cells from 41 patients with intrahepatic cholangiocarcinoma (iCCA). The MICA/B-specific 7C6 mAb was used for ex vivo antibody-dependent cytotoxicity (ADCC) experiments using circulating, non tumor liver- and tumor-infiltrating NK cells against the HuCCT-1 cell line and patient-derived primary iCCA cells as targets. MICA/B were more expressed in iCCA than in non-tumoral tissue, MICA transcription being higher in moderately-differentiated compared with poorly-differentiated cancer. Serum MICA was elevated in iCCA patients in line with higher expression of ADAM10 and ADAM17 that are responsible for proteolytic release of MICA/B from tumor. Addition of 7C6 significantly boosted peripheral, liver- and tumor-infiltrating-NK cell degranulation and IFNγ production toward MICA/B-expressing established cell lines and autologous iCCA patient target cells. Our data show that anti-MICA/B drives NK cell anti-tumor activity, and provide preclinical evidence in support of 7C6 as a potential immunotherapeutic tool for iCCA.

Brainstem neuropathology in two cases of COVID-19: SARS-CoV-2 trafficking between brain and lung

Introduction

SARS-CoV-2 might spread through the nervous system, reaching respiratory centers in the brainstem. Because we recently reported neurophysiological brainstem reflex abnormalities in COVID-19 patients, we here neuropathologically assessed structural brainstem damage in two COVID-19 patients.

Materials and methods

We assessed neuropathological features in two patients who died of COVID-19 and in two COVID-19 negative patients as controls. Neuronal damage and corpora amylacea (CA) numbers /mm² were histopathologically assessed. Other features studied were the immunohistochemical expression of the SARS-CoV-2 nucleoprotein (NP) and the Iba-1 antigen for glial activation.

Results

Autopsies showed normal gross brainstem anatomy. Histopathological examination demonstrated increased neuronal and CA damage in Covid-19 patients’ medulla oblongata. Immunohistochemistry disclosed SARS-CoV-2 NP in brainstem neurons and glial cells, and in cranial nerves. Glial elements also exhibited a widespread increase in Iba-1 expression. Sars-Co-V2 was immunohistochemically detected in the vagus nerve fibers.

Discussion

Neuropathologic evidence showing SARS-CoV-2 in the brainstem and medullary damage in the area of respiratory centers strongly suggests that the pathophysiology of COVID-19-related respiratory failure includes a neurogenic component. Sars-Co-V2 detection in the vagus nerve, argues for viral trafficking between brainstem and lung.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00415-021-10604-8.

Endothelial-Mesenchymal Transition in COVID-19 lung lesions

Sars-Cov-2 infection is still a healthcare emergency and acute respiratory distress failure with Diffuse Alveolar Damage (DAD) features is the main causes of patients’ death. Pathogenic mechanisms of the disease are not clear yet, but new insights are necessary to improve therapeutic management, to prevent fatal irreversible multi-organ damage and to adequately follow up those patients who survive. Here we investigated, by histochemistry and immunohistochemistry, a wide number of mapped lung specimens taken from whole body autopsies of 7 patients dead of COVID-19 disease. Our data confirm morphological data of other authors, and enlarge recent reports of the literature suggesting that Endothelial–Mesenchymal Transition might be central to COVID-19 lung fibrosing lesions. Furthermore, based upon recent acquisition of new roles in immunity and vascular pathology of the CD31 molecule, we hypothesize that this molecule might be important in the development and treatment of COVID-19 pulmonary lesions. These preliminary findings need further investigations to shed light on the complexity of Sars-Cov-2 disease.

Evidence of SARS-CoV-2 Transcriptional Activity in Cardiomyocytes of COVID-19 Patients without Clinical Signs of Cardiac Involvement

Aims: A considerable proportion of patients affected by coronavirus respiratory disease (COVID-19) develop cardiac injury. The viral impact in cardiomyocytes deserves, however, further investigations, especially in asymptomatic patients. Methods: We investigated for SARS-CoV-2 presence and activity in heart tissues of six consecutive COVID-19 patients deceased from respiratory failure showing no signs of cardiac involvement and with no history of heart disease. Cardiac autopsy samples were collected within 2 h after death, and then analysed by digital PCR, Western blot, immunohistochemistry, immunofluorescence, RNAScope, and transmission electron microscopy assays. Results: The presence of SARS-CoV-2 into cardiomyocytes was invariably detected in all assays. A variable pattern of cardiomyocyte injury was observed, spanning from absence of cell death and subcellular alterations hallmarks, to intracellular oedema and sarcomere ruptures. In addition, we found active viral transcription in cardiomyocytes, by detecting both sense and antisense SARS-CoV-2 spike RNA. Conclusions: In this autopsy analysis of patients with no clinical signs of cardiac involvement, the presence of SARS-CoV-2 in cardiomyocytes has been detected, determining variable patterns of intracellular damage. These findings suggest the need for cardiologic surveillance in surviving COVID-19 patients not displaying a cardiac phenotype.

Jagged Ligands Enhance the Pro-Angiogenic Activity of Multiple Myeloma Cells

Simple Summary

The Jagged family of ligands are aberrantly expressed during multiple myeloma progression and contributes to activate Notch signaling both in myeloma cells and in the nearby bone marrow cell populations activating several pro-tumor effects. This work elucidates, in vitro, in vivo as well as in patients’ bone marrow biopsies, different mechanisms by which tumor cell-derived Jagged1 and 2 contribute to myeloma-associated angiogenesis. These include the ability to induce myeloma and bone marrow stromal cell secretion of VEGF along with a direct activation of the pro-angiogenic Notch signaling pathway in endothelial cells. This research provides a rational for a Jagged-directed therapy in multiple myeloma.

Abstract

Multiple myeloma (MM) is an incurable plasma cell malignancy arising primarily within the bone marrow (BM). During MM progression, different modifications occur in the tumor cells and BM microenvironment, including the angiogenic shift characterized by the increased capability of endothelial cells to organize a network, migrate and express angiogenic factors, including vascular endothelial growth factor (VEGF). Here, we studied the functional outcome of the dysregulation of Notch ligands, Jagged1 and Jagged2, occurring during disease progression, on the angiogenic potential of MM cells and BM stromal cells (BMSCs). Jagged1–2 expression was modulated by RNA interference or soluble peptide administration, and the effects on the MM cell lines’ ability to induce human pulmonary artery cells (HPAECs) angiogenesis or to indirectly increase the BMSC angiogenic potential was analyzed in vitro; in vivo validation was performed on a zebrafish model and MM patients’ BM biopsies. Overall, our results indicate that the MM-derived Jagged ligands (1) increase the tumor cell angiogenic potential by directly triggering Notch activation in the HPAECs or stimulating the release of angiogenic factors, i.e., VEGF; and (2) stimulate the BMSCs to promote angiogenesis through VEGF secretion. The observed pro-angiogenic effect of Notch activation in the BM during MM progression provides further evidence of the potential of a therapy targeting the Jagged ligands.

Unexpected thymoma in a challenging case of hyperparathyroidism

We report the case of a woman with primary hyperparathyroidism suspected of mediastinal ectopic parathyroid adenoma revealed to be a thymoma. Our aim was to focus on some possible criticisms in distinguishing between ectopic parathyroid and thymus.

Candida isolates causing candidemia show different degrees of virulence in Galleria mellonella

We aim to assess intra- and interspecies differences in the virulence of Candida spp. strains causing candidemia using the invertebrate Galleria mellonella model. We studied 739 Candida spp. isolates (C. albicans [n = 373], C. parapsilosis [n = 203], C. glabrata [n = 92], C. tropicalis [n = 53], and C. krusei [n = 18]) collected from patients with candidemia admitted to Gregorio Marañon Hospital (Madrid, Spain). Species-specific infecting inocula (yeast cells/larva) were adjusted (5 × 105 [C. albicans, and C. tropicalis], 2 × 106-5 × 106 [C. parapsilosis, C. glabrata, and C. krusei]) and used to infect 10 larvae per isolate; percentage of survival and median survival per isolate were calculated. According to the interquartile range of the median survival, isolates with a median survival under P25 were classified as of high-virulence and isolates with a median survival over P75 as of low virulence. The median survival of larvae infected with different species was variable: C. albicans (n = 2 days, IQR <1-3 days), C. tropicalis (n = 2 days, IQR 1.5-4 days), C. parapsilosis (n = 2 days, IQR 2-3.5 days), C. glabrata (n = 3 days, IQR 2-3 days), and C. krusei (n = 7 days, 6.5->8 days) (P < .001). Differences in virulence among species were validated by histological examination (day +1 post-infection) in the larvae infected by the isolates of each virulence category and species. Virulence-related gene expression in C. albicans isolates did not reach statistical significance. We report species-specific virulence patterns of Candida spp. and show that isolates within a given species have different degrees of virulence in the animal model.

Inflammatory role of extracellular sphingolipids in Cystic Fibrosis

Ceramide is emerging as one of the players of inflammation in lung diseases. However, data on its inflammatory role in Cystic Fibrosis (CF) as part of the extracellular machinery driven by lung mesenchymal stem cells (MSCs)-derived extracellular vesicles (EVs) are missing. We obtained an in vitro model of CF-MSC by treating control human lung MSCs with a specific CFTR inhibitor. We characterized EVs populations derived from MSCs (ctr EVs) and CF-MSCs (CF-EVs) and analyzed their sphingolipid profile by LC-MS/MS. To evaluate their immunomodulatory function, we treated an in vitro human model of CF, with both EVs populations. Our data show that the two EVs populations differ for the average size, amount, and rate of uptake. CF-EVs display higher ceramide and dihydroceramide accumulation as compared to control EVs, suggesting the involvement of the de novo biosynthesis pathway in the parental CF-MSCs. Higher sphingomyelinase activity in CF-MSCs, driven by inflammation-induced ceramide accumulation, sustains the exocytosis of vesicles that export new formed pro-inflammatory ceramide. Our results suggest that CFTR dysfunction associates with an enhanced sphingolipid metabolism leading to the release of EVs that export the excess of pro-inflammatory Cer to the recipient cells, thus contributing to maintain the unresolved inflammatory status of CF.

Microbiologic and clinical characteristics of biofilm-forming Candida parapsilosis isolates associated with fungaemia and their impact on mortality

OBJECTIVES

Biofilm formation (BF) by fungal isolates may dramatically complicate infection. We determined the ability of Candida parapsilosis isolates from single fungaemia episodes to form biofilms and we analysed biofilm subgroups for antifungal susceptibility and pathogenic potential. We then correlated BF with clinical characteristics and outcomes of the episodes.

METHODS

BF was measured using the crystal violet biomass assay. Antifungal susceptibility of preformed biofilms was assessed, and virulence was studied using the Galleria mellonella model. A retrospective analysis of patients' clinical records was performed.

RESULTS

Of 190 patient-unique isolates, 84, 38 and 68 were identified as having high BF (HBF), moderate BF (MBF) or low BF (LBF), respectively. Among 30 randomly selected isolates, nine (eight HBF and one MBF), six (all HBF) and one (HBF) isolates had elevated sessile minimum inhibitory concentrations to fluconazole, anidulafungin or amphotericin B; all HBF and MBF isolates had elevated voriconazole sessile minimum inhibitory concentrations. G. mellonella killing rates of HBF isolates were significantly greater than MBF (or LBF) isolates (50% vs. 20%, 2 days from infection). By comparing HBF/MBF (106 patients) and LBF (84 patients) groups, we found that HBF/MBF patients had more central venous catheter-related fungaemias (62/106 (58.5%) vs. 29/84 (34.5%), p 0.001) and were more likely to die at 30 days from fungaemia onset (61/106 (57.5%) vs. 28/84 (33.3%), p 0.01). In the HBF/MBF group, azole antifungal therapy and central venous catheter removal were significantly associated with a higher and lower 30-day mortality rate, respectively.

CONCLUSIONS

C. parapsilosis BF influences the clinical outcome in patients with fungaemia.

Overcoming an Extremely Drug Resistant (XDR) Pathogen: Avibactam Restores Susceptibility to Ceftazidime for Burkholderia cepacia Complex Isolates from Cystic Fibrosis Patients

Burkholderia multivorans is a significant health threat to persons with cystic fibrosis (CF). Infections are difficult to treat as this pathogen is inherently resistant to multiple antibiotics. Susceptibility testing of isolates obtained from CF respiratory cultures revealed that single agents selected from different antibiotic classes were unable to inhibit growth. However, all isolates were found to be susceptible to ceftazidime when combined with the novel non-β-lactam β-lactamase inhibitor, avibactam (all minimum inhibitor concentrations (MICs) were ≤8 mg/L of ceftazidime and 4 mg/L of avibactam). Furthermore, a major β-lactam resistance determinant expressed in B. multivorans, the class A carbapenemase, PenA was readily inhibited by avibactam with a high k₂/K of (2 ± 1) × 10⁶ μM^-1 s^-1 and a slow k_off of (2 ± 1) × 10^-3 s^-1. Mass spectrometry revealed that avibactam formed a stable complex with PenA for up to 24 h and that avibactam recyclized off of PenA, re-forming the active compound. Crystallographic analysis of PenA-avibactam revealed several interactions that stabilized the acyl-enzyme complex. The deacylation water molecule possessed decreased nucleophilicity, preventing decarbamylation. In addition, the hydrogen-bonding interactions with Lys-73 were suggestive of a protonated state. Thus, Lys-73 was unlikely to abstract a proton from Ser-130 to initiate recyclization. Using Galleria mellonella larvae as a model for infection, ceftazidime-avibactam was shown to significantly (p < 0.001) improve survival of larvae infected with B. multivorans. To further support the translational impact, the ceftazidime-avibactam combination was evaluated using susceptibility testing against other strains of Burkholderia spp. that commonly infect individuals with CF, and 90% of the isolates were susceptible to the combination. In summary, ceftazidime-avibactam may serve as a preferred therapy for people that have CF and develop Burkholderia spp. infections and should be considered for clinical trials.

M1 and M2 macrophages' clinicopathological significance in cutaneous melanoma

Skin malignant melanoma (MM) is an aggressive cancer with an increasing incidence with limited therapies in advanced stages. Tumor-associated macrophages (TAMs) are the major immune constituent of the MM microenvironment and contribute toward its prognosis. TAMs' characterization and localization in human cancer is important to understand cancer progression and to identify molecular personalized therapies. M2 TAMs in stage I-II MMs are associated with worse prognostic parameters. A comprehensive M1-macrophage and M2-macrophage intratumoral localization and quantification in all stages of skin MMs is documented here with its clinical significance. To highlight immune pathways and possible early indicators of MM progression, we evaluated the number of M1 and M2 TAMs and intratumoral distribution in a large series of skin MMs. CD68 double immunostaining with MRP8-14 or inducible nitric oxide synthase (M1 macrophages) and with CD163 or CD204 (M2 macrophages) was performed in 94 stage I-IV skin MMs with a long duration of follow-up. The accumulation and distribution of M1 and M2 TAMs in intratumoral nests, stroma, and at the invasive front was correlated with clinicopathological variables. Since the early stage of MMs, M1 intratumoral macrophages were fewer than the M2 population; their recruitment was rapidly and progressively overwhelmed by an increase in M2 TAMs during MM progression. Independent of their intratumoral distribution, the accumulation of both M1 and M2 TAMs is associated with poor prognostic indicators and patients' survival. M1-recruited macrophages shift to the M2 phenotype early in MM development, possibly induced by high inducible nitric oxide synthase intratumoral increase peculiarly occurring since the initial MM stages. M2-recruited TAMs overwhelm M1 accumulation in all stages of MM progression, thus favoring neoplastic growth and dissemination. Independent of their intratumoral distribution, the prevalent accumulation of M2 TAMs in MM is statistically confirmed to be a poor indicator of patients' outcome and a potential target of immune therapies.

Myriocin treatment of CF lung infection and inflammation: complex analyses for enigmatic lipids

Our aim was to use quantitative and qualitative analyses to gain further insight into the role of ceramide in cystic fibrosis (CF). Sphingolipid ceramide is a known inflammatory mediator, and its accumulation in inflamed lung has been reported in different types of emphysema, chronic obstructive pulmonary disease and CF. CF is caused by a mutation of the chloride channel and associated with hyperinflammation of the respiratory airways and high susceptibility to ongoing infections. We have previously demonstrated that de novo ceramide synthesis is enhanced in lung inflammation and sustains Pseudomonas aeruginosa pulmonary infection in a CF murine model. We used liquid chromatography and matrix-assisted laser desorption/ionization (MALDI) imaging coupled with mass spectrometry, confocal laser scan microscopy and histology analyses to reveal otherwise undecipherable information. We demonstrated that (i) upregulated ceramide synthesis in the alveoli is strictly related to alveolar infection and inflammation, (ii) alveolar ceramide (C16) can be specifically targeted by nanocarrier delivery of the ceramide synthesis inhibitor myriocin (Myr) and (iii) Myr is able to downmodulate pro-inflammatory lyso-PC, favouring an increase in anti-inflammatory PCs. We concluded that Myr modulates alveolar lipids milieu, reducing hyperinflammation and favouring anti-microbial effective response in CF mouse model.

Prognostic Value of the Diverticular Disease Severity Score Based on CT Colonography: Follow-up in Patients Recovering from Acute Diverticulitis

RATIONALE AND OBJECTIVES

To assess the prognostic value of a diverticular disease severity score (DDSS) based on computed tomography colonography (CTC) after acute diverticulitis (AD).

MATERIALS AND METHODS

Of 252 patients who had an AD episode, we finally selected 46 patients who underwent both conventional CT at the acute event and CTC after 9 ± 7 weeks. Of these 46 patients, 17 underwent elective surgery after CTC. Disease severity was assessed with a 0-4 modified Hinchey CT-based score and a 1-4 CTC-based DDSS. A phone survey was performed 27 months later (range 4-52) for the 29 patients not surgically treated.

RESULTS

Significant correlation was found between CTC-based DDSS and clinical follow-up (P = 0.022) or elective surgery (P = 0.007), but not between clinical follow-up and CT-based score, extraluminal gas, C-reactive protein serum level, age, gender, or first versus recurrent AD episode. CTC demonstrated relevant additional findings in five of 46 (11%) patients: two AD complications (enterocolic and enterotubal fistulae), two colon cancers, and one extracolonic (lung) cancer.

CONCLUSIONS

The CTC-based DDSS showed a prognostic value and correlated with the risk of undergoing surgery, and clinically relevant additional findings were found in more than 10% of patients. CTC could be the preferred test in patients recovering after AD.

The sialyl-glycolipid stage-specific embryonic antigen 4 marks a subpopulation of chemotherapy-resistant breast cancer cells with mesenchymal features

Introduction

Chemotherapy resistance resulting in incomplete pathologic response is associated with high risk of metastasis and early relapse in breast cancer. The aim of this study was to identify and evaluate biomarkers of treatment-resistant tumor cells.

Methods

We performed a cell surface marker screen in triple-negative breast cancer patient-derived xenograft models treated with standard care genotoxic chemotherapy. Global expression profiling was used to further characterize the identified treatment-resistant subpopulations.

Results

High expression of sialyl-glycolipid stage-specific embryonic antigen 4 (SSEA4) was found in residual tumor cells surviving chemotherapy and in samples from metastatic patients who relapsed after neoadjuvant chemotherapy. Gene and microRNA (miRNA) expression profiling linked SSEA4 positivity with a mesenchymal phenotype and a deregulation of drug resistance pathways. Functional assays demonstrated a direct link between epithelial–mesenchymal transition (EMT) and SSEA4 expression. Interestingly, SSEA4 expression, EMT, and drug resistance seemed to be regulated posttranscriptionally. Finally, high expression of CMP-N-acetylneuraminate-β-galactosamide-α-2,3-sialyltransferase 2 (ST3GAL2), the rate-limiting enzyme of SSEA4 synthesis, was found to be associated with poor clinical outcome in breast and ovarian cancer patients treated with chemotherapy.

Conclusions

In this study, we identified SSEA4 as highly expressed in a subpopulation of tumor cells resistant to multiple commonly used chemotherapy drugs, as well as ST3GAL2, the rate-limiting enzyme of SSEA4 synthesis, as a predictive marker of poor outcome for breast and ovarian cancer patients undergoing chemotherapy. Both biomarkers and additionally identified regulatory miRNAs may be used to further understand chemoresistance, to stratify patient groups in order to avoid ineffective and painful therapies, and to develop alternative treatment regimens for breast cancer patients.

Electronic supplementary material

The online version of this article (doi:10.1186/s13058-015-0652-6) contains supplementary material, which is available to authorized users.

A histological procedure to study fungal infection in the wax moth Galleria mellonella

The invertebrate model Galleria mellonella is a widely used factitious host to study the microbial pathogenesis in vivo. However, a specific procedure for the recovery and the processing of the infected tissues, important for a better understanding of the host-pathogen interactions, has not been reported to our knowledge. In the present study we describe a new procedure of fixation and processing of larval tissue that allows studying the larval topographic anatomy and assessing the morphological changes due to the fungal infection. Lepidopteran larvae were infected with Candida albicans strains displaying various biofilm-forming abilities. The whole larvae were then examined for tissue changes by histological techniques. We show that comparing cutting planes, serial transversal sections of paraffin-embedded larva result in better accuracy and information recovering. Using this technique, it was possible to preserve the integrity of G. mellonella internal structures allowing the detailed analysis of morphological differences in different experimental groups (i.e., healthy vs infected larvae). We were also able to study strain-related differences in the pathogenesis of C. albicans by observing the immune response elicited and the invasiveness of two isolates within the larval tissues. In general, by processing the whole larva and optimizing routinely histochemical stainings, it is possible to visualize and analyse infected tissues. Various degrees of pathogenicity (strain- or inoculum-related), and the infection time course can be described in details. Moreover, the host immune response events can be followed throughout the infectious process leading to a comprehensive picture of the studied phenomenon.

Biofilms formed by Candida albicans bloodstream isolates display phenotypic and transcriptional heterogeneity that are associated with resistance and pathogenicity

BACKGROUND

Candida albicans infections have become increasingly recognised as being biofilm related. Recent studies have shown that there is a relationship between biofilm formation and poor clinical outcomes in patients infected with biofilm proficient strains. Here we have investigated a panel of clinical isolates in an attempt to evaluate their phenotypic and transcriptional properties in an attempt to differentiate and define levels of biofilm formation.

RESULTS

Biofilm formation was shown to be heterogeneous; with isolates being defined as either high or low biofilm formers (LBF and HBF) based on different biomass quantification. These categories could also be differentiated using a cell surface hydrophobicity assay with 24 h biofilms. HBF isolates were more resistance to amphotericin B (AMB) treatment than LBF, but not voriconazole (VRZ). In a Galleria mellonella model of infection HBF mortality was significantly increased in comparison to LBF. Histological analysis of the HBF showed hyphal elements intertwined indicative of the biofilm phenotype. Transcriptional analysis of 23 genes implicated in biofilm formation showed no significant differential expression profiles between LBF and HBF, except for Cdr1 at 4 and 24 h. Cluster analysis showed similar patterns of expression for different functional classes of genes, though correlation analysis of the 4 h biofilms with overall biomass at 24 h showed that 7 genes were correlated with high levels of biofilm, including Als3, Eap1, Cph1, Sap5, Plb1, Cdr1 and Zap1.

CONCLUSIONS

Our findings show that biofilm formation is variable amongst C. albicans isolates, and categorising isolates depending on this can be used to predict how pathogenic the isolate will behave clinically. We have shown that looking at individual genes in less informative than looking at multiple genes when trying to categorise isolates at LBF or HBF. These findings are important when developing biofilm-specific diagnostics as these could be used to predict how best to treat patients infected with C. albicans. Further studies are required to evaluate this clinically.

A rare case of transmural endometriosis in primary adenocarcinoma of the rectum

Intestinal endometriosis of the rectum and sigmoid colon, occurring in up to 34% of pelvic endometriosis, mimics a wide number of conditions that are difficult to differentiate from inflammatory or malignant diseases. Herein we report the first case of transmural endometriosis concomitant with advanced primary rectal adenocarcinoma, presenting with obstructive symptoms. Correct diagnosis based on morphological identification and immunohistochemical characterization of the two entities is crucial for treatment.

Schwann cell hamartoma: case report

Background

Colorectal polyps of mesenchymal origin represent a small percentage of gastrointestinal (GI) lesions. Nevertheless, they are encountered with increasing frequency since the widespread adoption of colonoscopy screening.

Case presentation

We report a case of a small colonic polyp that presented as intramucosal diffuse spindle cell proliferation with a benign cytological appearance, strong and diffuse immunoreactivity for S-100 protein, and pure Schwann cell phenotype. Careful morphological, immunohistochemical and clinical evaluation emphasize the differences from other stromal colonic lesions and distinguish it from schwannoma, a circumscribed benign nerve sheath tumor that rarely arises in the GI tract.

Conclusion

As recently proposed, this lesion was finally described as mucosal Schwann cell hamartoma.

An imbalance of COX level is not related to placental abruption

AIMS

Muscularised basal plate arteries (MA) or chorioamnionitis (CA) are often present in placental abruption. The aim of this study was to evaluate the placental expression of COX 1 and COX 2 in cases of placental abruption with MA or CA hypothesising that an imbalance in COX placental expression might be implicated in its pathogenesis.

METHODS

COX 1 and COX 2 placental immunostaining was analysed in 16 placentas with abruption (nine with MA, seven with CA), in 26 normal placentas and in 10 gestational age-matched MA or CA cases without abruption.

RESULTS

COX 1 and COX 2 protein expression was observed in all cases, both in placental abruption and in normal placentas. No differences in distribution of immunoreactivity were observed either between cases and controls or between MA and CA. The mean COX 1 ratio between COX-positive cells and all stromal cells was significantly lower in placental abruption with MA (0.14±0.05) when compared with cases with CA (0.35±0.06) and normal placenta (0.23±0.02; p<0.001). The mean COX 2 ratio was lower in placental abruption with MA than in normal placenta (0.09±0.06 vs 0.18±0.05: p<0.001). In contrast, no difference in COX 1 and COX 2 ratio was observed between MA cases with or without abruption and between CA cases with or without abruption.

CONCLUSIONS

It is hypothesised that an imbalance of normal COX level may be present in cases with MA and CA but it is not related to placental abruption.

Identification of potential therapeutic targets in malignant mesothelioma using cell-cycle gene expression analysis

Cell-cycle defects are responsible for cancer onset and growth. We studied the expression profile of 60 genes involved in cell cycle in a series of malignant mesotheliomas (MMs), normal pleural tissues, and MM cell cultures using a quantitative polymerase chain reaction-based, low-density array. Nine genes were significantly deregulated in MMs compared with normal controls. Seven genes were overexpressed in MMs, including the following: CDKN2C, cdc6, cyclin H, cyclin B1, CDC2, FoxM1, and Chk1, whereas Ube1L and cyclin D2 were underexpressed. Chk1 is a principal mediator of cell-cycle checkpoints in response to genotoxic stress. We confirmed the overexpression of Chk1 in an independent set of 87 MMs by immunohistochemistry using tissue microarrays. To determine whether Chk1 down-regulation would affect cell-cycle control and cell survival, we transfected either control or Chk1 siRNA into two mesothelioma cell lines and a nontumorigenic (Met5a) cell line. Results showed that Chk1 knockdown increased the apoptotic fraction of MM cells and induced an S phase block in Met5a cells. Furthermore, Chk1 silencing sensitized p53-null MM cells to both an S phase block and apoptosis in the presence of doxorubicin. Our results indicate that cell-cycle gene expression analysis by quantitative polymerase chain reaction can identify potential targets for novel therapies. Chk1 knockdown could provide a novel therapeutic approach to arrest cell-cycle progression in MM cells, thus increasing the rate of cell death.

Survivin gene expression in chronic liver disease and hepatocellular carcinoma

BACKGROUND/AIMS

Survivin is an oncofetal protein involved both in cell death and cell cycle regulation. Survivin is undetectable or found at very low levels in normal differentiated tissues whereas increased expression has been observed in several human malignancies, including lung, colon and liver cancer. The aim of this study was to evaluate the diagnostic and clinical significance of Survivin expression in hepatocellular carcinoma and non-neoplastic liver tissues in a series of surgical patients.

METHODOLOGY

Survivin mRNA levels were quantitated by real time RT-PCR in 25 patients.

RESULTS

Survivin mRNA was documented in all liver tissues with significantly higher levels in neoplastic specimens (p=0.01). In non-neoplastic liver tissue, Survivin levels were correlated with activity score of chronic liver disease. Increased Survivin levels were correlated with high tumor grade (p=0.05) and vascular invasion (p= 0.005). Tumor recurrences were more frequent in patients with high Survivin levels, although the difference did not reach statistical significance.

CONCLUSIONS

Low levels of Survivin mRNA are present in normal and in non-neoplastic liver tissue. In hepatocellular carcinomas, high levels of Survivin are associated with aggressive tumor features. The prognostic significance of quantitative Survivin evaluation requires further studies.

Up-regulation of focal adhesion kinase in non-small cell lung cancer

Focal adhesion kinase (FAK) is a non-receptor tyrosine kinase linked to the integrin and growth factor receptor-signalling pathways that regulates a number of the biological processes involved in neoplastic transformation, invasion and metastases, such as cell adhesion, migration and apoptosis. Its up-regulation might play a role in the tumourigenesis of invasive tumours, but its involvement in human lung cancer tissues has not yet been determined. We immunohistochemically compared FAK expression and localisation in 60 formalin-fixed and paraffin-embedded non-small cell lung cancer (NSCLC) tissues with that in the surrounding non-neoplastic tissue and in a further five microscopically normal lungs. FAK mRNA levels were quantitatively determined by real-time RT-PCR in frozen tissue specimens of all of the tumours and 21 matched non-neoplastic lung parenchymas, and protein expression in 16 homogenates of the matched neoplastic/non-neoplastic specimens was evaluated by Western blotting. The three different techniques showed that FAK is weakly expressed in non-neoplastic lung parenchyma and up-regulated in NSCLCs. Moreover, Western blotting and real-time RT-PCR indicated a statistically significant correlation between FAK up-regulation and higher disease stages (I+II versus III+IV, p=0.019 and 0.028, respectively). Our results provide evidence that FAK is up-regulated in NSCLCs, and suggest its potential involvement in lung cancer progression.

SEL1L expression in non-small cell lung cancer

SEL1L gene product plays a role in cell transformation and tumor progression in human breast, pancreas, esophageal, and prostate cancer. SEL1L expression was evaluated in a series of 76 surgically resected non-small cell lung carcinomas to investigate its clinical significance. SEL1L is scarcely detectable in normal lung, whereas in the initial stages of cell transformation, it becomes consistently expressed with evident staining in bronchial squamous metaplasia and in associated dysplastic changes. SEL1L immunoreactivity can be detected both in the cytoplasm and less commonly in the nuclei; the subcellular location correlates with tumor histotype, with cytoplasmic immunoreactivity being most prevalent in squamous cell carcinomas (P = .0005) and nuclear immunoreactivity being associated with adenocarcinomas (P = .02). Nuclear import and export signals are present in the SEL1L coding sequence, justifying the different subcellular location of the protein. SEL1L immunoreactivity was inversely correlated with tumor grade (P = .05); when considering only the adenocarcinomas, a stronger association was found (P = .006). SEL1L messenger RNA and protein evaluation in lung cancer cell lines confirmed the expression of the gene and the dual subcellular location of the protein in lung tumors. The data here reported suggest that, in non-small cell lung carcinoma, SEL1L may be an indicator of cell transformation, thus having important biologic and clinical implications.

EGFR overexpression in malignant pleural mesothelioma. An immunohistochemical and molecular study with clinico-pathological correlations

The epidermal growth factor receptor (EGFR) is overexpressed in many epithelial malignancies, against which some antitumoral drugs have been developed. There is a lack of information as to EGFR expression in malignant pleural mesothelioma (MPM), an aggressive and fatal cancer poorly responsive to current oncological treatments. Our aim was to: (a) compare EGFR immunohistochemical expression with mRNA levels measured by real time PCR; (b) assess the relationships between EGFR expression and clinico-pathological data including survival; (c) analyze the EGFR mutations. We developed an immunohistochemical method of EGFR evaluation based on the number of immunoreactive cells and staining intensity in 61 MPMs. EGFR immunoreactivity was documented in 34/61 (55.7%) cases. A significant correlation between EGFR protein and mRNA levels (p = 0.0077) was found, demonstrating the reliability of our quantification method of EGFR membrane expression. Radically resected patients (p = 0.005) and those with epithelial histotype (p = 0.048) showed an increased survival. No statistical correlation between EGFR immunoreactivity and patients survival was observed. No EGFR mutation was documented. This study documents EGFR overexpression in MPM at the protein and the transcriptional levels; it proposes a reliable method for EGFR expression evaluation in MPM. EGFR levels are not associated with clinico-pathological features of patients, including survival.

Quantitative Real-time Polymerase Chain Reaction Detection of Lymph Node Lung Cancer Micrometastasis Using Carcinoembryonic Antigen Marker

STUDY OBJECTIVES

The survival of patients with surgically resected stage I non-small cell lung cancer (NSCLC) is not optimal, probably because of unsuspected systemic occult tumor dissemination. The current applied technologies and methods for scanning the body and examining lymph nodes for tumor cells have broadly recognized limitations. Several studies have reported that it is possible to detect occult lymph node metastases (micrometastases) using more sensitive methods such as immunohistochemistry or molecular technology. The aim of our study was to evaluate the utility of quantitative real-time reverse-transcriptase polymerase chain reaction (RT-PCR) for carcinoembryonic antigen (CEA) messenger RNA (mRNA) for detection of lymph node micrometastases and its impact on disease-free interval.

METHODS

Quantitative real-time RT-PCR for CEA mRNA was performed on primary lung tumors and regional lymph nodes from 44 surgically resected NSCLC patients classified as clinical stage I. Fourteen lymph nodes from five patients without malignancy were used as controls. The end point of clinical analysis was cancer recurrence. Average follow-up was 22.5 months.

RESULTS

CEA mRNA was detected in all but four lymph nodes used as controls. All primary tumors were positive for CEA mRNA. Of 261 lymph nodes analyzed, 35 lymph nodes (13.4%) showed CEA mRNA levels higher than those detected in control lymph nodes and were considered positive for micrometastasis. Survival analysis by micrometastases showed less cancer recurrences in patients with lymph nodes negative for CEA mRNA (log rank, 5.3; p = 0.021). Among tumor type, tumor grading, age, sex, and molecularly detected lymph node micrometastases, the most powerful predictor of cancer recurrences was the presence of micrometastases (Cox proportional hazard, 3.3; p = 0.027).

CONCLUSION

Quantitative real-time RT-PCR for CEA mRNA can be applied for detection of micrometastases in lymph nodes. This technique may be an appropriate tool in predicting cancer recurrences, and further studies are warranted to determine the most useful clinical applications.

Quantitative evaluation of the apoptosis regulating genes Survivin, Bcl-2 and Bax in inflammatory and malignant pleural lesions

AIM

We aimed to identify defects in the programmed cell death pathway that can be related to pleural malignant mesothelioma (MM) unresponsiveness to chemotherapy.

MATERIALS AND METHODS

We quantified mRNA levels of the apoptosis regulating genes Survivin, member of the IAP family, Bcl-2 and Bax, members of the Bcl-2 family. We studied 22 non-neoplastic pleural samples, comprising normal and inflammatory tissue specimens, and 42 pleural MMs using real-time RT-PCR.

RESULTS

Very low mRNA levels of each apoptotic gene were detected in all normal pleural samples. All three genes displayed increased mRNA levels in inflammatory and tumor specimens. Survivin levels in pleuritis and MMs were significantly increased (333% and 908%, respectively) compared to normal counterparts (p=0.0147 and 0.00349, respectively). Bcl-2 and Bax levels were increased in inflammatory pleural samples (394%, p=0.001 and 188%, p=ns, respectively) and in MMs (94%, p=ns and 88%, p=0.0163, respectively). The Bcl-2/Bax ratio was higher in pleuritis than in MMs, compared to normal pleurae (441%, p=ns and 22%, p=ns, respectively); the difference between Bcl-2/Bax ratio in inflammatory and neoplastic pleural samples was significant (p=0.00375).

CONCLUSIONS

These results suggest that apoptotic defects in pleural MMs are linked to increased levels of Survivin, whereas variations in Bcl-2 and Bax expression appear less significant, although further studies are needed to highlight Bcl-2 family members interactions in apoptosis control. Survivin progressive accumulation from normal pleura to MM suggests this gene may be important in mesothelial cancerogenesis. Survivin overexpression may also be involved in pleural MM resistance to oncological therapies. Therefore, Survivin may represent a promising novel target for selective therapies.

HER-2/Neu alterations in non-small cell lung cancer: a comprehensive evaluation by real time reverse transcription-PCR, fluorescence in situ hybridization, and immunohistochemistry

PURPOSE

Amplification and/or overexpression of HER2/neu have been documented in many types of epithelial tumor, and HER2/neu evaluation is now gaining importance, because this mechanisms of disease can be inhibited in vivo using humanized monoclonal antibodies. The main purpose of our investigation includes the evaluation of the prevalence of HER2/neu alterations in non-small cell lung cancer (NSCLC) at different molecular levels.

EXPERIMENTAL DESIGN

We performed a comprehensive investigation of HER2/neu alterations in a series of 115 NSCLC, using fluorescence in situ hybridization (FISH), real time reverse transcription (RT)-PCR, and immunohistochemistry.

RESULTS

HER2/neu immunoreactivity was detected in 26 of 115 of specimens (23%), with 5 carcinomas (4%) showing intense staining. Real time RT-PCR demonstrated HER2/neu mRNA in all samples analyzed, with levels above normal in 54 of 115 of carcinomas (47%). FISH documented HER2/neu gene amplification in 9 of 41 carcinomas (22%).

CONCLUSIONS

These results demonstrate that HER2/neu alterations occur in NSCLC, albeit with significantly different prevalence depending on the technical assay used for the assessment. It is therefore likely that inhibitory monoclonal antibodies will be appropriate in the treatment of a subgroup of NSCLC patients. The results suggest that other mechanisms unrelated to gene amplification could be responsible for HER2/neu mRNA or protein overexpression. FISH, real time RT-PCR, and immunohistochemistry are complementary techniques for the evaluation of HER2/neu activation, useful for the identification of the subgroup of patients to be treated. The real time RT-PCR assay is very sensitive and requires minimal amounts of tissue for testing, and additional studies should evaluate its clinical application for patient evaluation.

Survivin gene expression in early-stage non-small cell lung cancer

Survivin is an inhibitor of apoptosis protein, overexpressed in most human malignancies and implicated in mitosis regulation and preservation of cell viability. In order to investigate the prevalence and clinical significance of survivin in early-stage non-small cell lung carcinoma (NSCLC), survivin mRNA levels and protein expression were evaluated, using quantitative real-time RT-PCR and immunohistochemistry, respectively, in a series of 83 patients with stage I (IA and IB) surgically resected NSCLC. Detectable survivin mRNA levels could be demonstrated in all non-neoplastic lung tissue samples and in the tumours analysed. Survivin mRNA levels were elevated in 80 carcinomas (96%) compared to normal lung (p = 0.008). Among all tumours, survivin transcripts were present at a higher level in squamous cell carcinomas (p = 0.0022). Cytoplasmic and nuclear immunoreactivity was found in 70% and 80% of tumours, respectively and both were present in 54%. Cytoplasmic immunoreactivity correlated with tumour stage (p = 0.019). Survivin expression levels did not correlate with patient survival. In one specimen, cytoplasmic and focal nuclear immunostaining was observed in dysplastic bronchial squamous metaplasia. These results document that survivin overexpression is almost always present in early-stage NSCLC, suggesting that this protein may play a role in lung tumourigenesis. This ubiquitous expression makes survivin an appealing new target for novel therapies in lung cancer. In addition, this study also documents that survivin overexpression could be exploited for diagnostic purposes and that quantitative real-time RT-PCR can be a useful tool for evaluating survivin activation in NSCLC.

Prediction of survival in stage I lung carcinoma patients by telomerase function evaluation

Telomerase activity and telomerase reverse transcriptase (hTERT) expression are elevated in human malignancies. We have investigated telomerase activity measured by the telomeric repeat amplification protocol (TRAP) assay and hTERT levels by real-time RT-PCR in stage I non-small-cell lung carcinomas. The purposes of our study included the comparison of these two techniques in the assessment of telomerase function and the evaluation of their prognostic significance. Telomerase activity and hTERT levels were determined in 90 stage I non-small-cell lung carcinoma patients, using TRAP assay and real-time RT-PCR, respectively. Variables were analyzed by the chi(2) and Fisher exact tests. Survival was analyzed by the Kaplan-Meier method. Multivariate analysis was performed with the Cox's proportional hazards model. Telomerase activity was elevated in 60 (67%) carcinomas. hTERT was elevated in 43 (48%) carcinomas. Only 21 (23%) tumors had low telomerase function by both TRAP and hTERT expression levels. Telomerase activity and hTERT were significantly correlated (p = 0.017), although 35 cases displayed discordant results. Both telomerase activity and hTERT levels were significantly associated with poor patient overall and disease-free survival (p = 0.019 and p = 0.018 for TRAP, and p = 0.011 and p = 0.012 for hTERT, respectively). Among the 21 patients with tumors displaying low telomerase function, defined by both TRAP and hTERT expression levels, only one succumbed to the disease (p = 0.0053). Our results suggest that the two techniques used in this study evaluate separate aspects of telomerase function and their combination provides powerful prognostic information in lung cancer patients.

Unusual clear cell variant of epithelioid mesothelioma

Clear cell mesothelioma is an extremely rare neoplasm of the pleura, which can easily be mistaken for a metastasis of clear cell carcinoma to the pleura. We report here the histochemical, immunohistochemical, and ultrastructural aspects of a new case of clear cell pleural mesothelioma in a 52-year-old man with no known asbestos exposure. He was admitted to the hospital for recurrent pleural effusion, which was negative for neoplastic cells at the cytologic examination. A partial decortication of the right pleura was performed. The morphologic, immunohistochemical, and ultrastructural features reported for this case are consistent with the diagnosis of clear cell mesothelioma. The differential diagnosis and immunohistochemical features in comparison with other clear cell neoplasms are discussed.

Primary intrathoracic meningioma: histopathological, immunohistochemical and ultrastructural study of two cases

Meningiomas are common, usually benign slow-growing neoplasms of the central nervous system thought to arise from meningocytes capping arachnoid villi. Primary ectopic meningiomas are exceedingly rare extracranial and extraspinal tumors of controversial origin; they are usually limited to the head and neck region or to the paravertebral soft tissues. Only one mediastinal ectopic meningioma and few pulmonary ectopic meningiomas have been described in the literature until now. Because of their rarity and their intriguing pathogenesis, we report here a second case of primary mediastinal meningioma and an additional case of primary pulmonary meningioma. Their possible origin and differential diagnosis are discussed.

[Surfactant protein and thyroid transcription factor 1 in pleuro-pulmonary neoplasia. Immunohistochemical study]

Aim of this work was to investigate the ability of the antibodies against Surfactant proteins (SP) and Thyroid transcription factor 1 (TTF-1) to distinguish primary neoplasms of the lung from metastatic carcinomas to the lung and pleural mesotheliomas. We evaluated the immunohistochemical expression of the antibodies anti SP-A, SP-B, pro SP-C, SP-D, and TTF-1 in a series of 56 primary lung carcinomas, 9 metastatic carcinomas to the lung, 5 pleural mesotheliomas and 8 non-pulmonary carcinomas. Among primary lung neoplasms, only adenocarcinomas immunostained for all SP (specificity = 1; total sensitivity = 0.52). TTF-1 had an excellent specificity (= 1), but a weak sensitivity (= 0.34) in recognizing primary lung carcinomas. TTF-1 was present in lung adenocarcinomas which were negative for SPs; however it failed to distinguish the subtypes. Pleural mesotheliomas, pulmonary metastases and non-pulmonary carcinomas were not immunoreactive for SP-A, SP-B, SP-D, and TTF-1. Pro SP-C was positive also in the adenocarcinomas of the large bowel and in their pulmonary and nodal metastases. These results demonstrate that the combined use of antibodies anti SP-A, SP-B and TTF-1 is the best association in distinguishing primary lung carcinomas from metastatic carcinomas to the lung and pleural mesotheliomas.

Peripheral papillary tumor of type-II pneumocytes: a rare neoplasm of undetermined malignant potential

Peripheral papillary adenomas of the lung are uncommon neoplasms (only ten cases have been described so far in the English literature) composed predominantly of type-II pneumocytes and generally considered benign. We describe here two additional cases of this lung tumor. In both cases histological examination revealed an encapsulated papillary neoplasm with invasion of the capsule and, in one case, invasion of the adjacent alveoli and visceral pleura too. The proliferative index (Ki67) was less than 2% and the epithelial cells were positive for cytokeratins, surfactant apoproteins (SP), and nuclear thyroid transcription factor-1 (TTF- 1). Ultrastructurally, the epithelial cells showed the characteristic surface microvilli and cytoplasmic lamellar inclusions of type-II cells. Review of the literature has revealed two other cases of peripheral papillary adenoma of type-II pneumocytes with infiltrative features. Thus, we propose replacing the term peripheral papillary adenoma with peripheral papillary tumor of undetermined malignant potential.

Impact of the Pathfinder in a cytology laboratory

OBJECTIVE

To assess the value of Pathfinder (CompuCyte, Cambridge, Massachusetts, U.S.A.) in improving adequacy and accuracy of screening and supporting quality control programs.

STUDY DESIGN

The investigations were carried out on cervical cytologic smears only. Screening adequacy was assessed through the evaluation of percentage of slide coverage, percentage of overlapping and amount of elapsed time on smears screened with or without the Pathfinder by junior (426 cases) and senior (1,552 cases) screeners. Screening accuracy was investigated by comparing the performances of the same observer when reexamining, with the Pathfinder, a series of 1,051 cases already evaluated without the Pathfinder at least three months earlier. The review process was analyzed by both monitoring the elapsed time for relocation of manually or electronically marked cells (824 fields in 80 smears) and by comparing diagnostic discrepancies after the review of two series (74 + 74 cases) of randomly selected negative cases screened with or without Pathfinder.

RESULTS

Pathfinder-assisted screening increased the number of cases with optimal slide coverage (> or = 90% of screenable area) and optimal overlapping (between 15% and 20%) by both junior (P < .00001 and P < .00001) and senior (P < .00001 and P < .0003) screeners. It also improved screening accuracy by decreasing the number of cases "unsatisfactory for evaluation" (P < .00001) (as a consequence of better coverage and overlapping) and the number of diagnostic discrepancies detected after review (P = .05). During the latter process, the time elapsed for relocation of electronically marked fields, as compared to manually marked ones, was greatly reduced (1 hour, 25 minutes saved for revision of 40 smears).

CONCLUSION

In these preliminary studies, the Pathfinder was a useful tool for both education and diagnosis (screening and review) in a cytology laboratory.

Pancreatic malignant melanoma with occult primary lesion. A case report

A case of unusual location of a M.M. in the head of pancreas is described. Evidence of a primary lesion was not achieved, still we incline to retain this case as a metastatic malignant melanoma with occult primary location.

Duodenal gangliocytic paraganglioma. Report of a case and review of the literature

A case of gangliocytic paraganglioma (GP) of the ampulla of Vater is reported and the literature reviewed, with special attention to immunohistochemical studies. The present case, which occurred in a 56-year-old woman, shows the typical histological admixture of epithelioid, ganglion and spindle cells. Immunohistochemistry reveals strong reactivity for synaptophysin, Leu-7, somatostatin, S-100 protein and vimentin. A few ganglion cells are reactive for neurofilaments. Chromogranin A, myelin basic protein, desmin and cytokeratin are absent. Immunohistochemical data from literature regarding the cytoskeletal composition of GPs are not unequivocal: cytokeratin and neurofilament positivity is reported by some authors and denied by others. More uniformity is reported concerning the peptides produced by GPs: somatostatin and pancreatic polypeptide are the most frequently found antigens, followed by serotonin. General neuroendocrine markers like neuron specific enolase and protein gene product 9.5 are always positive, whereas chromogranins are rarely found. S-100 protein is always positive in the spindle cell component. Our data are in keeping with those previously reported and add the diffuse positivity for the Leu-7 antigen and the positivity of ganglion cells for synaptophysin. The nature of the tumour is still a matter of debate and it is difficult to agree with either of the proposed hypotheses--hamartoma/choristoma versus true neoplasm. However the recent reports of the occasional malignant evolution of GPs may support their true neoplastic nature.