Expression profiling of extramedullary acute myeloid leukemia suggests involvement of epithelial-mesenchymal transition pathways

Extramedullary (EM) colonization is a rare complication of acute myeloid leukemia (AML), occurring in about 10% of patients, but the processes underlying tissue invasion are not entirely characterized. Through the application of RNAseq technology, we examined the transcriptome profile of 13 AMLs, 9 of whom presented an EM localization. Our analysis revealed significant deregulation within the extracellular matrix (ECM)-receptor interaction and focal-adhesion pathways, specifically in the EM sites. The transcription factor TWIST1, which is known to impact on cancer invasion by dysregulating epithelial-mesenchymal-transition (EMT) processes, was significantly upregulated in EM-AML. To test the functional impact of TWIST1 overexpression, we treated OCI-AML3s with TWIST1-siRNA or metformin, a drug known to inhibit tumor progression in cancer models. After 48 h, we showed downregulation of TWIST1, and of the EMT-related genes FN1 and SNAI2. This was associated with significant impairment of migration and invasion processes by Boyden chamber assays. Our study shed light on the molecular mechanisms associated with EM tissue invasion in AML, and on the ability of metformin to interfere with key players of this process. TWIST1 may configure as candidate marker of EM-AML progression, and inhibition of EMT-pathways may represent an innovative therapeutic intervention to prevent or treat this complication.

The Endoscopic Retrograde Cholangiopancreatography and Endoscopic Ultrasound Connection: Unity Is Strength, or the Endoscopic Ultrasonography Retrograde Cholangiopancreatography Concept

Endoscopic ultrasound (EUS) and endoscopic retrograde cholangiopancreatography (ERCP) are both crucial for the endoscopic management of biliopancreatic diseases: the combination of their diagnostic and therapeutic potential is useful in many clinical scenarios, such as indeterminate biliary stenosis, biliary stones, chronic pancreatitis and biliary and pancreatic malignancies. This natural and evident convergence between EUS and ERCP, which by 2006 we were calling the "Endoscopic ultrasonography retrograde colangiopancreatography (EURCP) concept", has become a hot topic in the last years, together with the implementation of the therapeutic possibilities of EUS (from EUS-guided necrosectomy to gastro-entero anastomoses) and with the return of ERCP to its original diagnostic purpose thanks to ancillary techniques (extraductal ultrasound (EDUS), intraductal ultrasound (IDUS), cholangiopancreatoscopy with biopsies and probe-based confocal laser endomicroscopy (pCLE)). In this literary review, we retraced the recent history of EUS and ERCP, reported examples of the clinical applicability of the EURCP concept and explored the option of performing the two procedures in only one endoscopic session, with its positive implications for the patient, the endoscopist and the health care system. In the last few years, we also evaluated the possibility of combining EUS and ERCP into a single endoscopic instrument in a single step, but certain obstacles surrounding this approach remain.

Diarrhea due to parasites: a short, updated point of view from the clinical setting

Diarrhea represents a common manifestation of several gastrointestinal diseases. Infectious agents are the most common causes of diarrhea in developing countries, where the inadequate sanitation and hygiene are prevalent. In these countries, the scarcity of preventive measures as well as the limited health resources cause a substantial increase in incidence, morbidity and mortality due to infectious diseases, including diarrhea. Currently, with the availability of rapid and inexpensive air transportation millions of people travel for tourism, work and immigration from developing countries to industrialized countries and vice versa. This leads to a high number of imported pathogens such as parasites causing infectious diarrhea. Importantly, while most cases of parasitic diarrhea are short, mild and self-limited, other cases may be associated with chronic diarrhea and serious morbidity and mortality. The aim of the current review was to provide an update, from a clinician's point of view, of the main parasites causing diarrhea, with a focus on their diagnosis and management in the clinical setting.

Involvement of transcribed lncRNA uc.291 and SWI/SNF complex in cutaneous squamous cell carcinoma

While non-melanoma skin cancers (NMSCs) are the most common tumours in humans, only the sub-type cutaneous squamous cell carcinoma (cSCC), might become metastatic with high lethality. We have recently identified a regulatory pathway involving the lncRNA transcript uc.291 in controlling the expression of epidermal differentiation complex genes via the interaction with ACTL6A, a component of the chromatin remodelling complex SWI/SNF. Since transcribed ultra-conserved regions (T-UCRs) are expressed in normal tissues and are deregulated in tumorigenesis, here we hypothesize a potential role for dysregulation of this axis in cSCC, accounting for the de-differentiation process observed in aggressive poorly differentiated cutaneous carcinomas. We therefore analysed their expression patterns in human tumour biopsies at mRNA and protein levels. The results suggest that by altering chromatin accessibility of the epidermal differentiation complex genes, down-regulation of uc.291 and BRG1 expression contribute to the de-differentiation process seen in keratinocyte malignancy. This provides future direction for the identification of clinical biomarkers in cutaneous SCC. Analysis of publicly available data sets indicates that the above may also be a general feature for SCCs of different origins.

Hepatic follicular lymphoma in an old patient with Crohn's disease: a rare case and review of the literature

OBJECTIVE

Crohn's Disease (CD) has been associated with non-Hodgkin lymphoma. Follicular Lymphoma (FL) limited to the liver is extremely rare, accounting for 1% to 4.4% of all Primary Hepatic Lymphoma (PHL).

CASE PRESENTATION

In 2018, an 85-years old male patient with post-operative recurrence of ileal CD referred rare episodes of fever and mild diffuse abdominal pain. Since cholecystectomy in 2001, clinical history was characterized by recurrent episodes of cholangitis and common bile duct stones. In 2018, ultrasonography and MRI showed a solid focal hepatic lesion (FHL)(4.5 cm x 2.5 cm) in the IV hepatic segment. The radiographic aspect of the lesion was unusual. Initially, focal nodular hyperplasia was suspected. Clinical history of cholangitis and radiological findings subsequently suggested a diagnosis of Hepatic Abscess (HA). A progressive enlargement of the FHL (7.3 cm x 5.8 cm) despite antibiotic treatments, led to perform a liver biopsy. Histological and immunophenotypical analysis of the FHL (7.5 cm x 5.4 cm) enabled a final diagnosis of FL. The "in situ" hybridization for Epstein-Barr virus (EBER) was negative. No additional lesions related to FL were initially detected, thus suggesting a very rare case of PHL in an old patient with CD never treated with thiopurines.

CONCLUSIONS

This case report highlights the need to consider a rare diagnosis of FL of the liver in patients showing a challenging focal hepatic lesion of unknown origin.

Primary Malignant Fibrous Histiocytoma of Storiform-Pleomorphic Type: A Case Report of an Ano-Rectal Localization

Among the various localizations of primary malignant histiocytoma, the ano-rectal one is exceedingly rare. In this paper we report a case characterized by a storiform-pleomorphic pattern of the tumor and a rapid fatal course of the disease with metastasis in the lungs. The prognostic value of the histologic features is briefly discussed.

Cellular prognostic markers in hepatitis-related hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the most common primary liver malignancy and accounts for about 6% of all new cancers diagnosed worldwide. Moreover, it is the third and the fifth leading cause of death from cancer in men and women, respectively. HBV and HCV chronic infection is the main risk factor for HCC.

A range of therapies are used in the management of HCC according to the extent and severity of liver disease. In this perspective, evaluation of prognosis represents a crucial step for proper management of HCC patients. However, the clinical outcome can be significantly different in HCC patients within the same stage of disease. Therefore, many efforts have been made to define new parameters with more precise prognostic value, and the search for HCC prognostic markers is gaining momentum. The present review aims at providing an update on cellular prognostic markers for HCC.

A Computerized Coding System for Processing Basic Histopathological Changes – Application to Vascular Pathology

Among the numerous existing computer-based systems for processing pathological data, none contains sufficient space for encoding data on the basic cytological or histological changes of a certain organ or tissue, upon which the final diagnosis is based.

An “analytical record” was constructed listing all the basic changes that can be encountered in the various pathological conditions of the vascular wall. The data collected on the “analytical record” were coded by means of an alphanumeric code and stored in an Apple II 48 K minicomputer.

The advantages of this system include the computerization of the data by non-specialized personnel and the possibility to’ quantitatively analyze the histocytopathological parameters used for diagnosis in vascular pathology. This coding system may easily be adapted, with minor modifications, to the histopathological study of other organs and tissues.

Carotid plaque instability is not related to quantity but to elemental composition of calcification

BACKGROUND AND AIMS

Recent studies highlighted the role of calcification processes in the clinical progression of chronic cardiovascular diseases. In this study we investigated the relationship between the chemical composition of calcification and atherosclerotic plaque stability in carotid arteries.

METHODS AND RESULTS

To this end, we characterized the calcification on 229 carotid plaques, by morphology, immunohistochemistry, transmission electron microscopy and energy dispersive X-ray microanalysis. Plaques were classified into two categories: unstable and stable. No significant differences were found in the incidence of the various risk factors between patients with and without carotid calcification, with the exception of diabetes. The energy dispersive X-ray microanalysis allowed us to identify two types of calcium salts in the atheromatous plaques, hydroxyapatite (HA) and calcium oxalate (CO). Our results showed that calcification is a common finding in carotid plaques, being present in 77.3% of cases, and the amount of calcium is not a factor of vulnerability. Noteworthy, we observed an association between HA calcification and unstable plaques. On the contrary, CO calcifications were mainly detected in stable plaques.

CONCLUSIONS

The presence of different types of calcification in atheromatous plaques may open new perspectives in understanding the molecular mechanisms of atheroma formation and plaque instability.

Arterial ageing: from endothelial dysfunction to vascular calcification

Complex structural and functional changes occur in the arterial system with advancing age. The aged artery is characterized by changes in microRNA expression patterns, autophagy, smooth muscle cell migration and proliferation, and arterial calcification with progressively increased mechanical vessel rigidity and stiffness. With age the vascular smooth muscle cells modify their phenotype from contractile to 'synthetic' determining the development of intimal thickening as early as the second decade of life as an adaptive response to forces acting on the arterial wall. The increased permeability observed in intimal thickening could represent the substrate on which low-level atherosclerotic stimuli can promote the development of advanced atherosclerotic lesions. In elderly patients the atherosclerotic plaques tend to be larger with increased vascular stenosis. In these plaques there is a progressive accumulation of both lipids and collagen and a decrease of inflammation. Similarly the plaques from elderly patients show more calcification as compared with those from younger patients. The coronary artery calcium score is a well-established marker of adverse cardiovascular outcomes. The presence of diffuse calcification in a severely stenotic segment probably induces changes in mechanical properties and shear stress of the arterial wall favouring the rupture of a vulnerable lesion in a less stenotic adjacent segment. Oxidative stress and inflammation appear to be the two primary pathological mechanisms of ageing-related endothelial dysfunction even in the absence of clinical disease. Arterial ageing is no longer considered an inexorable process. Only a better understanding of the link between ageing and vascular dysfunction can lead to significant advances in both preventative and therapeutic treatments with the aim that in the future vascular ageing may be halted or even reversed.

Luteolin-7-glucoside inhibits IL-22/STAT3 pathway, reducing proliferation, acanthosis, and inflammation in keratinocytes and in mouse psoriatic model

The epidermis is a dynamic tissue in which keratinocytes proliferate in the basal layer and undergo a tightly controlled differentiation while moving into the suprabasal layers. The balance between keratinocyte proliferation, differentiation, and death is essential, and its perturbation can result in pathological changes. Some common skin diseases, such as psoriasis, are characterized by hyperproliferation accompanied by inflammatory reactions, suggesting that molecules with topical anti-inflammatory and ROS scavenging abilities may be useful for their treatment. Here we investigate the potential of the flavone Luteolin-7-glucoside (LUT-7G) as a treatment for psoriasis. We show that LUT-7G leads to a modification of the cell cycle and the induction of keratinocyte differentiation, with modification of energy, fatty acid, and redox metabolism. LUT-7G treatment also neutralizes the proliferative stimulus induced by the proinflammatory cytokines IL-22 and IL-6 in HEKn. Moreover, in the Imiquimod (IMQ) mouse model of psoriasis, topical administration of LUT-7G leads to a marked reduction of acanthosis and re-expression of epidermal differentiation markers. Dissection of the IL-22 signalling pathway, activated by IMQ treatment, demonstrates that LUT-7G impairs the nuclear translocation of phosphorylated (activated) STAT3, blocking the IL-22 signalling cascade. Thus LUT-7G appears to be a promising compound for the treatment of hyperproliferative and inflammatory skin diseases, such as psoriasis.

PTX3: a modulator of human coronary plaque vulnerability acting by macrophages type 2

BACKGROUND

Acute myocardial infarction (AMI), is related to a diffuse active inflammation of the coronary tree associated with rupture of one of the multiple vulnerable plaques. The presence of soluble mediators of inflammation with their synergic or antagonistic actions coordinates the physiological response determining the plaque fate and the fatal event. The present study focus on the cytokines network operating in human coronary plaques of patients died from AMI and controls, pointing out that coronaries of AMI patients produce PTX3 protein twice as that of controls and express high level of PTX3 mRNA.

RESULTS

The presence of CX3CR1 polymorphisms is significantly correlated with the incidence and the outcome of acute myocardial infarction inducing in the whole coronary tree a strong recruitment of Th1 polarized inflammation that is directly correlated to PTX3 expression.

CONCLUSIONS

Moreover we found a positive correlation between the expression of PTX3 in the plaque and the content of macrophage cells showing a M2 polarization indicating the possible role of this chemokine as mediator of immune response that would orchestrate plaque evolution and inflammatory cell type activation.

MiR-216a: a link between endothelial dysfunction and autophagy

Endothelial dysfunction and impaired autophagic activity have a crucial role in aging-related diseases such as cardiovascular dysfunction and atherosclerosis. We have identified miR-216a as a microRNA that is induced during endothelial aging and, according to the computational analysis, among its targets includes two autophagy-related genes, Beclin1 (BECN1) and ATG5. Therefore, we have evaluated the role of miR-216a as a molecular component involved in the loss of autophagic function during endothelial aging. The inverse correlation between miR-216a and autophagic genes was conserved during human umbilical vein endothelial cells (HUVECs) aging and in vivo models of human atherosclerosis and heart failure. Luciferase experiments indicated BECN1, but not ATG5 as a direct target of miR-216a. HUVECs were transfected in order to modulate miR-216a expression and stimulated with 100 μg/ml oxidized low-density lipoprotein (ox-LDL) to induce a stress repairing autophagic process. We found that in young HUVECs, miR-216a overexpression repressed BECN1 and ATG5 expression and the ox-LDL induced autophagy, as evaluated by microtubule-associated protein 1 light chain 3 (LC3B) analysis and cytofluorimetric assay. Moreover, miR-216a stimulated ox-LDL accumulation and monocyte adhesion in HUVECs. Conversely, inhibition of miR-216a in old HUVECs rescued the ability to induce a protective autophagy in response to ox-LDL stimulus. In conclusion, mir-216a controls ox-LDL induced autophagy in HUVECs by regulating intracellular levels of BECN1 and may have a relevant role in the pathogenesis of cardiovascular disorders and atherosclerosis.

DNA methylation silences miR-132 in prostate cancer

Silencing of microRNAs (miRNAs) by promoter CpG island methylation may be an important mechanism in prostate carcinogenesis. To screen for epigenetically silenced miRNAs in prostate cancer (PCa), we treated prostate normal epithelial and carcinoma cells with 5-aza-2'-deoxycytidine (AZA) and subsequently examined expression changes of 650 miRNAs by megaplex stemloop reverse transcription-quantitative PCR. After applying a selection strategy, we analyzed the methylation status of CpG islands upstream to a subset of miRNAs by methylation-specific PCR. The CpG islands of miR-18b, miR-132, miR-34b/c, miR-148a, miR-450a and miR-542-3p showed methylation patterns congruent with their expression modulations in response to AZA. Methylation analysis of these CpG islands in a panel of 50 human prostate carcinoma specimens and 24 normal controls revealed miR-132 to be methylated in 42% of human cancer cases in a manner positively correlated to total Gleason score and tumor stage. Expression analysis of miR-132 in our tissue panel confirmed its downregulation in methylated tumors. Re-expression of miR-132 in PC3 cells induced cell detachment followed by cell death (anoikis). Two pro-survival proteins-heparin-binding epidermal growth factor and TALIN2-were confirmed as direct targets of miR-132. The results of this study point to miR-132 as a methylation-silenced miRNA with an antimetastatic role in PCa controlling cellular adhesion.

Contrast carotid ultrasound for the detection of unstable plaques with neoangiogenesis: a pilot study

OBJECTIVES

To evaluate whether contrast ultrasonography can be used to distinguish asymptomatic from symptomatic carotid plaques and provide insight into underlying pathophysiological differences.

DESIGN

Contrast carotid ultrasound was performed in both symptomatic and asymptomatic patients referred for carotid endarterectomy.

MATERIALS AND METHODS

Of 77 consecutive patients referred for carotid artery evaluation, 64 underwent carotid endarterectomy for asymptomatic cerebrovascular disease and 9 underwent urgent surgery for acute neurological deficits with hemiparesis. The endarterectomy specimens were assessed immunohistologically.

RESULTS

In all 9 patients undergoing urgent surgery, contrast ultrasonography showed the accumulation of diffuse microbubble contrast at the base of the carotid plaque. This pattern was observed only in 1/64 of the patients undergoing surgery for asymptomatic carotid disease. Immunohistologically staining of the endarterectomy specimens showed that the area of microbubble contrast at the base of the symptomatic plaques was associated with an increased number of small diameter (20-30 microm) microvessels staining for vascular endothelial growth factor (VEGF).

CONCLUSIONS

Contrast carotid ultrasonography may allow the identification of microvessels with neoangiogenesis at the base of carotid plaques, and differentiate symptomatic from asymptomatic plaques.

Plasma levels of metalloproteinases-3 and -9 as markers of successful abdominal aortic aneurysm exclusion after endovascular graft treatment

BACKGROUND

Structural alterations of aortic wall resulting from degradation of matrix proteins by matrix metalloproteinases (MMPs) characterize abdominal aortic aneurysms (AAAs). No studies have compared circulating levels of MMPs after endovascular graft (EVG) exclusion in comparison with open surgical repair (OSR) in patients affected by AAA.

METHODS AND RESULTS

An abdominal angiography and CT scan were performed in all patients at the time of enrollment. A spiral CT scan was performed at 6 months to detect presence of endoleaks. MMP-3 and MMP-9 levels were measured before EVG (n=30) and OSR (n=15) treatments and at 1, 3, and 6 months of follow-up by a sandwich ELISA technique. Healthy volunteers (n=10) were used as control subjects. Immunohistochemical staining for MMP-9 and MMP-3 was performed on tissue samples from surgical cases. Both MMP-9 and MMP-3 mean basal levels were significantly higher in patients affected by AAA than in control subjects (32.3+/-20.7 ng/mL for EVG and 28+/-9.9 ng/mL for OSR versus 8.9+/-2.5 ng/mL, 2P<0.05; 18.3+/-9.7 ng/mL and 26.7+/-10.8 ng/mL versus 8.2+/-5.3 ng/mL, 2P<0.001). In the OSR group, both MMP-9 and MMP-3 mean levels decreased after surgery (28+/-9.9 ng/mL at basal versus 14.7+/-6.6 ng/mL at 6 months, 2P<0.001; 26.7+/-10.8 versus 12+/-5.3 ng/mL; 2P<0.001). In the EVG group, a statistically significant difference at 6-month follow-up in MMP-9 and MMP-3 mean plasma values was detected in patients who had endoleakage in comparison with patients without endoleakage (44.3+/-20.7 versus 14.6+/-7.0 ng/mL, 2P<0.005; 25+/-11.5 versus 10.3+/-5.4 ng/mL, 2P<0.005).

CONCLUSIONS

After EVG exclusion, MMP-9 and MMP-3 levels decreased to a level similar to that of patients undergoing OSR. In addition, a lack of decrease in MMP levels after EVG exclusion may help in identifying patients who will have endoleakage and consequent aneurysm expansion caused by continuous sac pressurization during follow-up.

Isolated ovarian metastasis from a spindle cell malignant melanoma of the choroid 14 years after enucleation: prognostic implication of the keratin immunophenotype

A 47-year-old woman developed metastatic melanoma to the right ovary 14 years after the enucleation of the right eye for a choroidal spindle cell melanoma. An immunohistochemical study was performed on paraffin sections of both primary and metastatic melanoma specimens to identify markers of both aggressive phenotype and metastatic potential with particular attention to the anomalous expression of cytokeratin intermediate filament proteins. Neoplastic cells of both primary and metastatic tumors immunostained positively for S-100, HMB45, MART-1, and vimentin antibodies, but they were negative for cytokeratins 1-19, 8, 18, and 8,18; <10% of neoplastic cells in both the primary and the metastatic melanomas immunostained for Ki-67 proliferating antigen using MIB-1 antibody. We speculate that the indolent behavior of this ovarian metastasis is reflected by the absence of coexpression of cytokeratins 8 and 18 with vimentin. This case supports the practical value of using this panel of antibodies to evaluate the aggressive potential of uveal melanomas.

Immunohistochemical analysis of estrogen receptors in breast carcinomas using monoclonal antibodies that recognize different domains of the receptor molecule

Estrogen receptor (ER) analysis was performed in 46 primary breast carcinomas using four monoclonal antibodies (MABs) to ER (AER311, ER1D5, LH1, and LH2), each of which recognizes a distinct domain of the receptor protein. ER was expressed as the percentage of positively stained tumor cells. Statistical analysis was performed using the SPSS/PC+ program to set the cut off of positivity and the prognostic value of each MAB. A positivity >30% for each MAB possessed the best sensitivity/specificity ratio and was used as the cut-off value. Multivariate discriminant analysis showed that MABs AER311, ER1D5, and LH2 had significant prognostic value. Fourteen tumors showed positivity for these three MABs; 17 were positive for one or two of the three MABs, and 15 were negative for all three MABs. Survival analysis showed that patients with tumors negative for all three of these MABs had progression of the disease within 8 years from the diagnosis of the tumor, whereas all patients with tumors positive for all three MABs were alive 13 years after surgery. A significant correlation (P = 0.0006) between tumor grading and ER status was found; 71% of the tumors that were positive for all three MABs were grade 1, whereas tumors negative for all three MABs were mostly grades 2 and 3. No significant relationship was observed between ER status and tumor size. A significant correlation (P = 0.008) between lymph node status and ER was found; breast tumors positive for all three MABs were in the majority (92.9%) of cases pNO, whereas 67% of tumors negative for all three MABs were pN1. Results from the present study suggest that the use of a panel of MABs that target distinct epitopes within domains of the ER protein could offer a better approach for assessing the ER status in breast cancer patients, because it enables the recognition of breast tumors with intact or structurally defective ER proteins.

Radiolabeled native low-density lipoprotein injected into patients with carotid stenosis accumulates in macrophages of atherosclerotic plaque : effect of vitamin E supplementation

BACKGROUND

Accumulation of LDL within the arterial wall appears to play a crucial role in the initiation and progression of atherosclerotic plaque. The dynamic sequence of this event has not been fully elucidated in humans.

METHODS AND RESULTS

In 7 patients with previous transient ischemic attack or stroke and critical (>70%) carotid stenosis, autologous native [(125)I]-labeled LDL or [(125)I]-labeled human serum albumin were injected 24 to 72 hours before endarterectomy. Carotid specimens obtained at endarterectomy were analyzed by autoradiography and immunohistochemistry. Autoradiographic study showed that LDL was localized prevalently in the foam cells of atherosclerotic plaques, whereas the accumulation in the lipid core was negligible. Immunohistochemistry revealed that foam cells that had accumulated radiolabeled LDL were mostly CD68 positive, whereas a small number were alpha-actin positive. No accumulation of the radiotracer was detected in atherosclerotic plaques after injection of radiolabeled human serum albumin. In 3 patients treated for 4 weeks with vitamin E (900 mg/d), an almost complete suppression of radiolabeled LDL uptake by macrophages was observed.

CONCLUSIONS

This study shows that circulating LDL rapidly accumulates in human atherosclerotic plaque. The prevalent accumulation of LDL by macrophages provides strong support to the hypothesis that these cells play a crucial role in the pathogenesis of atherosclerosis.

Hyperfibrinogenemia is associated with specific histocytological composition and complications of atherosclerotic carotid plaques in patients affected by transient ischemic attacks

BACKGROUND

Epidemiological studies have demonstrated that hyperfibrinogenemia is an independent risk factor for cerebrovascular atherosclerosis. However, the underlying mechanisms are poorly understood. We studied whether hyperfibrinogenemia could modify the histological composition of atherosclerotic plaque and precipitate carotid thrombosis resulting from rupture of the plaque.

METHODS AND RESULTS

We studied the histological composition of 71 carotid atherosclerotic plaques from patients who had undergone surgical endarterectomy after a first episode of transient ischemic attack. Patients were divided into 3 groups corresponding to the tertiles of plasma fibrinogen values. Hypercholesterolemia, hypertriglyceridemia, hypertension, diabetes, and smoking habit were also assessed. At the histological analysis, plaques of patients in the highest tertile of fibrinogen (>407 mg/dL) were characterized by a high incidence of thrombosis (66.7% of cases) compared with plaques of subjects in the lower (21.7%) (P=0.002) and middle (29. 2%) (P=0.009) tertiles. Plaque rupture was significantly associated with high fibrinogen levels (54.2%, P=0.003). Multivariate logistic regression indicated that hyperfibrinogenemia was an independent risk factor for a decrease in cap thickness (P=0.0005), macrophage foam cell infiltration of the cap (P=0.003), and thrombosis (P=0. 003). When the presence of other risk factors was accounted for, hyperfibrinogenemia remained an independent predictor of carotid thrombosis with an odds ratio of 5.83, compared with other risk factors.

CONCLUSIONS

The results of the present study add to the evidence that hyperfibrinogenemia, independently of other risk factors, is associated with a specific histological composition of carotid atherosclerotic plaques that predisposes them to rupture and thrombosis.

Flow cytometry analysis of atherosclerotic plaque cells from human carotids: a validation study

BACKGROUND

Atherosclerotic plaques are heterogeneous vascular lesions. Changes in cell plaque composition are fundamental events inside the plaque microenvironment that are strictly related to the clinical outcome of these lesions (organ damage). The knowledge of these modifications may help to better understand the pathophysiological mechanisms of atherosclerosis.

METHODS

We report on a flow cytometry method to characterize and quantify the cell subpopulations in human atherosclerotic plaques. Cells were obtained from endarterectomy specimens after collagenase digestion. Both surface and intracytoplasmic antigens were labeled.

RESULTS

Our data demonstrated that the method we described allowed the characterization of cell populations that compose the atherosclerotic plaque, avoiding contamination by tunica media smooth muscle cells and the noise of cellular debris. Moreover this validation study showed that about 50% of cells in the atherosclerotic plaques are inflammatory mononuclear cells (T lymphocytes and monocytes/macrophages).

CONCLUSIONS

Reproducible quantitative methods for cell population characterization may increase the understanding of pathophysiological mechanisms responsible for plaque progression. The methodology herein described gave us the possibility of quickly calculating the relative amount of each cell population and studying both surface and intracellular markers to analyze the functional stage of the cells. The clinical correlation was not assessed in the present study, because we used a small patient group to validate the method, but should be the subject of further analyses in a larger patient population.

Recurrent massive hyperplasia of the thymus

Differentiation of massive thymic hyperplasia from malignant lesions requires early resection. We report a case in which thoracoscopic thymectomy was performed for massive hyperplasia recurring 16 years after steroid therapy. This case provides additional information on the natural history, surgical management and histology of the disease.

Cavernous hemangioma of the parietal bone. Case report and review of the literature

Intraosseous cavernous hemangiomas are a rare finding in the calvarium. It is a benign tumor arising from the intrinsic vasculature of the bone. We report one case observed in a 20 year-old male. The diagnostic peculiarities and therapeutic implications of this lesion are discussed and the available literature on this subject is reviewed. These tumors do not recur once a radical surgical removal is performed.

Cardiac rhabdomyosarcoma: a clinicopathologic and electron microscopy study

A 66-year-old woman was admitted to the hospital with a neurological syndrome characterized by ataxia and diplopia. Magnetic resonance of the brain documented an ischemic medullary lesion. Examination of the heart revealed a grade 2/6 systolic murmur at the left sternal border and apex that radiated towards the axilla. The echocardiography study showed a mild mitral regurgitation, and an abnormally enlarged posterior papillary muscle was found in the left ventricle. Two weeks after admission, the patient died suddenly due to a stroke. At autopsy, a recent vast swollen ischemic cerebral infraction was found. Furthermore, two old infarcts were observed in the spleen. A cardiac examination showed a white-gray ulcered mass in the left ventricle and histological analysis revealed a rhabdomyosarcoma.

Localization of distinct F2-isoprostanes in human atherosclerotic lesions

F2-Isoprostanes are prostaglandin (PG) isomers formed in situ in cell membranes by peroxidation of arachidonic acid. 8-epi PGF2alpha and IPF2alpha-I are F2-isoprostanes produced in humans which circulate in plasma and are excreted in urine. Measurement of F2-isoprostanes may offer a sensitive, specific, and noninvasive method for measuring oxidant stress in clinical settings where reactive oxygen species are putatively involved. We determined whether isoprostanes were present in human atherosclerotic lesions, where lipid peroxidation is thought to occur in vivo. 8-epi PGF2alpha ranged from 1.310-3.450 pmol/micromol phospholipid in atherectomy specimens compared with 0.045-0.115 pmol/micromol phospholipid (P < 0.001) in vascular tissue devoid of atherosclerosis. Corresponding values of IPF2alpha-I were 5.6-13.8 vs. 0.16-0.44 pmol/micromol phospholipid (P < 0.001). Levels of the two isoprostanes in vascular tissue were highly correlated (r = 0.80, P < 0.0001). Immunohistochemical studies confirmed that foam cells adjacent to the lipid necrotic core of the plaque were markedly positive for 8-epi PGF2alpha. These cells were also reactive with anti-CD68, an epitope specific for human monocyte/macrophages. 8-epi PGF2alpha immunoreactivity was also detected in cells positive for anti-alpha-smooth muscle actin antibody, which specifically recognizes vascular smooth muscle cells. Our results indicate that 8-epi PGF2alpha and IPF2alpha-I, two distinct F2-isoprostanes and markers of oxidative stress in vivo, are present in human atherosclerotic plaque. Quantitation of these chemically stable products of lipid peroxidation in target tissues, as well as in biological fluids, may aid in the rational development of antioxidant drugs in humans.

Effect of long-term treatment with propionyl-L-carnitine on smooth muscle cell polyploidy in spontaneously hypertensive rats

Experimental studies suggest that DNA content is increased in the smooth muscle cells of the arteries of hypertensive animals. It is unclear whether an increase in DNA content occurring in the smooth muscle cells of hypertensive rats represents a pressure-dependent effect. To evaluate the antihypertensive effect of long-term treatment with propionyl-L-carnitine and the possible morphological changes in thoracic smooth muscle cells correlated with this effect, we studied 4-month-old spontaneously hypertensive rats (SHR) and Wistar-Kyoto rats (WKY) randomly divided into five groups. One group of SHR was treated with propionyl-L-carnitine for 12 months; the other four groups of SHR and WKY received no treatment and were controls. We used static and flow cytometry to evaluate the polyploid cell content in thoracic aorta smooth muscle cells. Systolic pressure in untreated SHR progressively increased during the experiment. Treatment did not significantly influence pressure values in SHR. In WKY, blood pressure was significantly lower than that in treated and untreated age-matched SHR (2P < .02). The number of polyploid smooth muscle cells was significantly lower in the propionyl-L-carnitine-treated SHR than in the untreated rats (2P < .04) and similar to values for WKY. The reduction of polyploid cells in treated SHR was paralleled by a significant decrease of the aortic total DNA content, whereas no modifications occurred in smooth muscle cell mass. Long-term treatment with propionyl-L-carnitine may interfere with cellular mechanisms regulating the secondary responses involved in DNA synthesis.

Age-related changes affecting atherosclerotic risk. Potential for pharmacological intervention

The incidence of cardiovascular diseases that are related to the atherosclerotic process increases exponentially with age. Organ lesions, the clinical manifestation of atherosclerotic disease, are late events due to complications in the plaque (ulceration, thrombosis, calcification) which are the result of an increased vulnerability to disruption of a previously stable plaque. The higher incidence of age-related clinical events could be explained by a rising sensitivity of plaques to destabilising factors, both parietal and humoral. The increased probability that a plaque in an elderly patient will became vulnerable could be related to those destabilising factors that significantly increase with aging, such as advanced glycation end-products. For these reasons, it seems most important that the analysis of these age-related destabilising factors, rather than those factors that promote the development of early atherosclerotic plaques, should be undertaken. Taking the point of view of a pharmacological intervention, this should eventually lead to a more complete understanding of this process.

Propionyl-L-carnitine prevents the progression of atherosclerotic lesions in aged hyperlipemic rabbits

We have characterized the extent and the phenotype of total and proliferating cell population of aortic plaques in aged rabbits receiving a long-term low-dose cholesterol hyperlipemic diet, which represents an experimental model of atherosclerosis. For nine months, rabbits received the hypercholesterolemic diet alone or in addition to a treatment with propionyl-L-carnitine (PLC), a derivative of carnitine, an intramitochondrial carrier of fatty acids present in most cell types. We observed that, in both PLC-treated and control hyperlipemic rabbits, the ratio between proliferating macrophage-derived and smooth muscle cells was 2:1. PLC in addition to the hypercholesterolemic diet induced a marked lowering of plasma triglycerides, very low density lipoprotein (VLDL) and intermediate density lipoprotein (IDL) triglycerides, while plasma cholesterol was slightly and transiently reduced. Moreover, PLC-treated hyperlipemic rabbits exhibited a reduction of plaque thickness and extent, a slight but significant reduction of the percentage of macrophage-derived cells as compared to control hyperlipemic animals and a reduction of the number of both proliferating macrophage- and smooth muscle cell-derived foam cells. Finally, both proliferating and non-proliferating plaque cells expressed large amounts of macrophage colony-stimulating factor protein, in particular macrophage-derived foam cells. These results indicate that a modification of plasma lipemic pattern obtained by a long-term oral administration of PLC was associated with a decrease of plaque cell proliferation and severity of aortic atherosclerotic lesions.

Relationships between risk factors and morphological patterns of human carotid atherosclerotic plaques. A multivariate discriminant analysis

The histological characterization of the fibroatheromatous plaques and their histogenesis are still to be defined. Factors responsible for the evolution of intimal components and the mechanisms and stages of fibroatheromatous plaque formation are still largely obscure. Focusing on symptomatic plaques, the aim of this study is to determine whether plaque heterogeneity is the result of a haphazard clustering of various components or an organized pattern in response to risk factors. To this end, 180 carotid plaques from patients affected by transient ischemic attacks (TIA) or by stroke, with angiographic stenosis greater than 50%, were studied after endoarterectomy. Clinical and morphological data were collected by means of a pre-defined protocol, quantified and correlated, by using the discriminant analysis, with age, sex, hypertension, diabetes, hypercholesterolemia and smoking habit. Our results show that the relationships between plaque components are non-random and consistent with the knowledge derived from studies on human and experimental plaques. Moreover, some plaque patterns can be significantly correlated with single risk factors. The fibrous plaque was correlated with aging and diabetes; the granulomatous plaque, rich in giant cells, with the female sex and hypertension; the xanthomatous plaque, rich in foam cells and with extensive alcianophilia, with hypercholesterolemia. In the smokers, finally, the plaques were frequently complicated by mural thrombosis.

Age-related modifications of aorta and coronaries in the rabbit: a morphological and morphometrical assessment

Aging seems to be related to various vascular diseases, such as dissecting aneurysm and atherosclerosis. The nature of the relationship between aging and these vascular diseases has not been completely clarified. The goal of this study was to investigate, using morphological and morphometrical methods, the age related modifications of the arterial wall in rabbits of three different ages, evaluating separately two different vascular districts and the various aortic segments. Our results confirm that the most relevant age-related structural aortic changes were the increase of thickness, length, volume and diameter of the vessels, together with the development of an intimal thickening. The latter was diffuse in the aorta and focal in coronary vessels and it appears earlier in the aorta than in the coronaries, being absent in the coronaries of young rabbits. In addition, morphological and ultrastructural studies revealed the presence in aged rabbits of some marked intimal storage of a ground substance into intimal thickening of proximal aortic segments. Morphometric studies demonstrated an age-related decrease of aortic cellularity of tunica media and a parallel increase of the content of collagen and glycosaminoglycans, whereas elastin did not vary. The different relationships between cells and interstitial tissue occurring with aging are most probably a phenomenon of adaptation to the changing forces acting on the arterial wall and they might constitute the structural background of the increased arterial susceptibility to various noxae. Finally, the intimal storage of the ground substance, probably related to a functional disturbance of endothelium and or smooth muscle cells, may play an initiating role in atherogenesis.

[Latent pathology of the thyroid: an epidemiological and statistical study of thyroids sampled during 507 consecutive autopsies]

In order to highlight the occult pathology of the thyroid in the aged, the authors examined all the glands withdrawn from 507 consecutive autopsies on subjects of 67.10 years of median age. In 10 tables there are weight and measurements of the thyroids, macro and microscopic details and pathologic appearances. Adenomas were found in 17.1% of cases and histologically besides the known cases referred also to the Hürtle cells type, 4 clear cells adenomas and 5 adenolipomas were found. In 27.42% the subjects were affected or were dead for a malignant extrathyroidal neoplasm, and in 26% of these there was a metastasis in the thyroid. Never a primitive thyroid carcinoma, macroscopically and clinically evident, but in 53 thyroid glands, 54 occult carcinomas (OC) were found, particularly 37 papillary and 17 medullary. IN 57% of 165 histologically treated thyroids, to evidence C-cells, hyperplasia of these cells was found associated with various pathologic conditions, more in aged subjects. In 147 glands were found 170 nodules of various number of cells, at times positive for calcitonin. These solid cellular nodes (SCN) were evaluated as nodular C-cells hyperplasia. Besides isolated cases of acute thyroiditis (also the mycotic type), of tubercular thyroiditis and Hashimoto's, in 12% of the glands a lymphocytic chronic thyroiditis was found, frequently with Hürtle cells. Others observations were: basophilic thickening of colloid also with calcium oxalate crystals, lipoid degeneration of follicular cells and fat interfollicular and interlobular infiltration, thyroid amyloidosis, inner and media elastic calcification of thyroid arteries, presence of cysts with squamous cells coating, parathyroid glands and cartilage intrathyroidal plaques.

Densitometric and morphometric study of immunocytochemical estrogen receptors detection in breast carcinomas

Immunohistochemical quantitative evaluation of estrogen receptors (ER) detected in tissue sections from 30 breast tumors by monoclonal antibody was performed using a densitometric method. In particular, ER concentration was calculated by nuclear mean optical density (nMOD), while heterogeneity in ER content was calculated by the coefficient of variation (CV) of the nuclear optical density histogram. Tumors which showed more than 60% of positive cells had a mean value of ER-nMOD of 0.116 +/- 0.002 a.u. and of ER-CV of 33.74 +/- 0.68. Tumors which showed 30% to 60% of positive cells had a mean value of ER-nMOD of 0.082 +/- 0.006 a.u. (arbitrary units) and of ER-CV of 36.25 +/- 3.44. Tumors showing less than 30% of positive cells had ER-nMOD of 0.052 +/- 0.009 a.u. and ER-CV of 48.49 +/- 5.61. These results indicate that the greater the concentration the lower the ER heterogeneity within the tumor sample. No significant differences between ER-ICA results, nuclear size and form factors were found.

Age-dependent increase of rabbit aortic atherosclerosis. A morphometric approach

Aging has been indicated as one of the major risk factors for development of atherosclerotic lesions, although the role aging plays, lacks accurate evaluation. Our study was aimed at quantitatively defining such a role by using morphometric analysis. Aged (median age 3 years and 8 months) and young (4 months) white New Zealand rabbits received a hyperlipemic diet enriched with a low dose of cholesterol for 16 months. At regular intervals, levels of serum lipemic parameters were checked. A Quantimet 920 image analyzer was used on paraffin-embedded sections of the entire aortas to measure the volume density of the tunica intima, the volume density of atheroma, the ratio intima/media and the surface area of the tunica intima. Our results indicated for aged hyperlipemic rabbits a statistically significant increase in all morphometric parameters examined as compared to young hyperlipemic animals, and no statistically significant differences in serum cholesterol, triglycerides and phospholipids.

Age-related modification of average volume and anisotropy of vascular smooth muscle cells

The aim of this study was to determine what changes in the arterial wall are related to age. In two groups of rabbits, one young and one adult, the aorta and carotid were studied using a morphometric approach based on stereological axioms and planimetric morphometry. The problem of anisotropy of smooth muscle cells is discussed in detail. Two forms of anisotropy must be distinguished, that of single cell and that due to the histological pattern of the smooth muscle cells in the arterial wall. Our results show in adult animals, as compared to the young ones, statistically significant decrease in anisotropy of the cell pattern which tends to become more regular. Moreover, in aorta and carotid of young and adult animals there is an increment of 95.39% and 80% of the absolute cell volume, respectively. We suggest that there may be a direct relationship between aging and phenotypical modulation of the smooth muscle cells and that the modification of the architectural cell pattern with age may represent an adaptive event related to the change in forces acting upon the arterial wall.

Platelet-activating factor (PAF) stimulates the lysoPAF acetyltransferase in leukocyte-rich plasma: use in PAF antagonist studies

Addition of platelet-activating factor (PAF; 1-O-alkyl-2-acetyl-sn-glycero-3-phosphocholine) to leukocyte-rich plasma from several species resulted in the rapid and pronounced activation of the PAF biosynthetic enzyme acetyl-CoA:1-O-alkyl-sn-glycero-3-phosphocholine acetyltransferase (EC 2.3.1.67). Activation of acetyltransferase by PAF occurred in leukocyte-rich plasma from human, chimpanzee, rhesus monkey, and dog. The neutrophil was indicated to be the major cellular source of the activatable acetyltransferase in leukocyte-rich plasma. The induction of acetyltransferase was substantial with 10 nM PAF, and maximal at 10-30 seconds. Measurable acetyltransferase activation was significantly greater when the PAF-activated cells were separated from the plasma by centrifugation before the acetyltransferase assay. This may be due in part to the removal of the PAF-specific acetylhydrolase present in plasma which can cleave the acetyl group from PAF. Measuring PAF activation of acetyltransferase in leukocyte-rich plasma can be useful to determine the potency of PAF antagonists with neutrophils in plasma compared to isolated neutrophils in aqueous buffer, and as an ex vivo assay to determine the efficacy and plasma concentration equivalents of antagonists administered to whole animals. The PAF antagonist L-659,989 was shown to be 3-5 times more potent in inhibiting PAF induction of acetyltransferase in isolated human neutrophils than in human leukocyte-rich plasma, with IC50 values of 10 nM and 40 nM, respectively. In the ex vivo assay, oral administration of the PAF antagonist L-667,131 to dogs resulted in very substantial inhibition of PAF induction of acetyltransferase in the leukocyte-rich plasma.(ABSTRACT TRUNCATED AT 250 WORDS)

Aging and atherosclerosis in the rabbit. 1. Distribution, prevalence and morphology of atherosclerotic lesions

Aging is considered a risk factor in the pathogenesis of atherosclerosis. It is not clear, however, whether the relationship between aging and atherosclerosis is the result of increased susceptibility of the arterial wall related to intrinsic alterations or the expression of the increase in intensity or duration of exposure to risk factors. In this study, we used aged (median age 46 months) and young (4 months old) New Zealand white rabbits. Nine aged and 11 young rabbits received a hyperlipemic diet enriched with a low dose of cholesterol for 18 months. Eleven aged and 8 young rabbits, fed standard chow for the same period, were used as controls. Using morphologic and morphometric methods, we detected in aged hyperlipemic rabbits (a) a marked prevalence of fibroatheromatous plaques (as opposed to fatty streaks in young hyperlipemic rabbits); (b) aortic lesions more extensive and of greater dimensions than in young hyperlipemic rabbits; (c) fibroatheromatous plaques in carotids and raised fatty streaks in the large subepicardial coronary branches. Our results show an increased susceptibility of the aged arterial wall to hypercholesterolemia.

High-dose synthetic progestogens inhibit foam and smooth muscle cell proliferation and atherosclerotic plaque formation in aortas of rabbits fed a hypercholesterolemic diet

Female rabbits on a hypercholesterolemic atherogenic diet were treated with high doses of the synthetic progestogens norethisterone and medroxyprogesterone acetate in order to clarify the effect and possibly some of the mechanism of action of these hormones on diet-induced atherogenesis. We employed morphometric studies to determine the surface area of the rabbit aorta occupied by and the maximum thickness of lipid plaques. Autoradiography with tritiated thymidine was performed to demonstrate the effect of the progestogens on cell proliferation, which plays a key role in atherogenesis. Medroxyprogesterone acetate-treated and, above all, norethisterone-treated animals exhibit a more marked reduction of atherosclerosis than control rabbits fed the same diet. Our results suggest that both progestogens we used inhibit the development of atherosclerosis mainly by blocking the proliferation of smooth muscle cells in the tunica media and the cell population of the plaque.

Morphometric evidence of the trophic effect of L-carnitine on human skeletal muscle

We investigated the effect of long-term i.v. administration of L-carnitine on human muscle fibers using morphometric parameters. We administered 2g/day L-carnitine to patients undergoing hemodialysis for at least 12 months. At the end of this period a marked increase in serum and muscle carnitine levels was observed in all patients, together with hypertrophy and predominance of type 1 fibers. L-carnitine was withheld for 4 months, during which time serum and muscle levels gradually decreased and no changes were observed in muscle fibers. Subsequent addition of L-carnitine to dialysis fluid for another 4 months stabilized lower levels. At the end of this period reduction of diameter of type 1 fibers was observed. Type 2 fibers remained unchanged. Moreover, type 1 fibers remained predominant in all cases. Hence, we suggest that carnitine has a specific trophic effect on type 1 fibers which are characterized by an oxidative metabolism.

Echodensitometry: a methodologic approach to the non-invasive diagnosis of carotid atherosclerotic plaques

The ultrasound image of the fibroatheromatous plaque has to date been unable to reveal the presence or absence of complications as shown by histology, such as thrombosis and intraplaque hemorrhage. We propose a novel densitometric method for determining the composition of the plaque at the echotomography, along with a new classification based on mathematical models drawn from the optical density distribution curve. This approach avails of an extremely high sensitivity. Percent areas occupied by thrombosis, intraplaque hemorrhage and atheroma in histologic sections have been shown to correspond to hyporeflecting areas in echotomographic images, whereas those occupied by calcium and fibrous tissue correspond to reflecting areas with or without acoustic shadow, respectively. This method may prove to have an important role in the non-invasive monitoring of even slight changes during progression or regression of the fibroatheromatous plaque.

Histopathological characterization of carotid plaques echotomography

The positive correlation between cerebral ischemia and carotid atherosclerosis of extracranial tract has been well established. The reliability of echotomography as diagnostic and prognostic tool in the evaluation of the carotid atherosclerotic lesions is now intensively investigated. Most of the attention has been payed to the accuracy in the determination of the carotid stenosis. A percentage of cerebrovascular accidents do not correlate to the vascular stenosis but to the other modifications induced by the atherosclerotic plaque, such as the release of emboli, acute stenosis for intraplaque haemorrhage or thrombosis. Thus the evaluation of the composition of the plaque may represent a good prognostic tool. In the present study, fifty-two carotid obtained at surgery from patients, who preoperatively underwent ultrasonographic scanning of both carotid arteries, were examined by histological methods. In calcified tissues a significant correlation between findings obtained with both techniques was observed. In the complicated plaques atheromasic gruel, intraplaque haemorrhages and thrombosis could not be discriminated by echotomography.