Clinical course of severe colitis: a comparison between Crohn’s Disease and ulcerative colitis.

Few data are available about the clinical course of severe colonic Crohn’s disease (CD). The aim of this study is to describe the clinical course of severe Crohn’s colitis in a patient cohort with isolated colonic or ileocolonic CD, and to compare it with the clinical course of patients with severe ulcerative colitis (UC). Thirty-four patients with severe Crohn’s colitis were prospectively identified in our cohort of 593 consecutive hospitalized patients through evaluation of the Crohn’s Disease Activity Index score and the Harvey-Bradshaw Index. One hundred sixty-nine patients with severe ulcerative colitis were prospectively identified in our cohort of 449 consecutive hospitalized patients through evaluation of the Lichtiger score and the Truelove-Witts score. We evaluated the following data/aspects: response to steroids, response to biologics, colectomy rate in acute, colectomy rate during follow-up, megacolon and cytomegalovirus infection rate. We did not find significant differences in the response to steroids and to biologics, in the percentage of cytomegalovirus infection and of megacolon, while the rate of colectomy in acute turned out to be greater in patients with severe Crohn’s colitis compared to patients with severe UC, and this difference appeared to be the limit of statistical significance (Chi-squared 3.31, p = 0.069, OR 0.39); the difference between the colectomy rates at the end of the follow-up was also not significant. In the whole population, by univariate analysis, according to the linear regression model, a young age at diagnosis is associated with a higher overall colectomy rate (p = 0.024) and a higher elective colectomy rate (p = 0.022), but not with a higher acute colectomy rate, and an elevated ESR is correlated with a higher overall colectomy rate (p = 0.014) and a higher acute colectomy rate (p = 0.032), but not with a higher elective colectomy rate. This correlation was significant on multivariate analysis. The overall rate of colectomy in the cohort of patients with severe Crohn’s colitis was greater than that of the cohort of patients with severe UC, but this figure is not supported by a different clinical response to steroid therapy or rescue therapy with biologics. The clinical course of severe Crohn’s colitis requires to be clarified by prospective studies that include a larger number of patients in this subgroup of disease.

Focal active colitis as a predictor of inflammatory bowel disease: results from a single-center experience.

The term focal active colitis (FAC) is conventionally used to describe the presence of isolated cryptitis, characterized by an inflammatory infiltrate consisting of intraepithelial neutrophils and/or neutrophils invading the lumen of the criptae, with no other microscopic alteration of the colonic mucosa and, in particular, without the presence of signs of chronic inflammation. To date, only four studies, including one conducted in a pediatric population, have been performed to evaluate the clinical significance of this disease. The aim of this retrospective study on prospectively-collected data is to evaluate the clinical implications of the focal active colitis, since there still remains a marked uncertainty regarding this topic and about how often such a diagnosis will presage a diagnosis of inflammatory bowel disease (IBD). Clinical, endoscopic, and pathological data were retrospectively reviewed from 30 patients with focal active colitis, who had no other diagnostic findings on colorectal biopsy and no history of chronic inflammatory bowel disease. The histological findings were correlated with clinical diagnoses. Thirty patients (11 males, 19 females; age 24-80 years, median 56 years) (0.5%) out of 5,600 undergoing colonoscopy between January 2012 and December 2016 presented a definitive diagnosis of FAC. Follow-up ranged from 6 to 60 months (median 24 months). At endoscopy, 19 patients (63%) had mild and non-specific changes, such as mild mucosal erythema, while 11 (37%) had normal findings. Eight patients were documented as having irritable bowel syndrome, while nine cases could be attributed to the effects of drugs, five presented FAC as incidental finding, one a diagnosis of infectious colitis, and seven a diagnosis of IBD (4 with Crohn’s disease). FAC was confirmed to be a more significant predictor of IBD than the previous literature would indicate, even if larger prospective studies, targeted to study this relationship, are needed to understand more clearly its clinical significance.

Colorectal cancer and inflammatory bowel diseases: effects of diet and antioxidants.

It is well established that oxidative stress is common in inflammatory bowel diseases (IBDs). Accordingly, antioxidants are recommended for treatment. The aim of this study is to compare the effects of antioxidants contained in the various types of tea on symptoms and evolution of IBD and colorectal cancer (CRC). Analysis of the literature revealed that the theaflavin-3, 30-digallate (TFDG) contained in black tea, and epigallocatechin-3-O-gallate (EGCG) contained in green tea have protective effects against oxidative stress. Moreover, these substances are involved in many biochemical processes responsible for inflammation and proliferation of cancer cells. It is documented that both TFDG and EGCG are able to reduce inflammatory phenomena and symptoms associated with IBD, as well as to reduce the proliferation of CRC cells. Most studies are performed in vitro or in experimental animal models. It is, therefore, advisable to formulate studies that could be carried out on humans or human samples, in order to develop the appropriate therapeutic strategies.

The fingerprint of the human gastrointestinal tract microbiota: a hypothesis of molecular mapping.

The precise etiology of Inflammatory Bowel Disease (IDB) remains unclear and several factors are believed to play a role in its development and progression, including the composition of microbial communities resident in the gastrointestinal tract. Human intestinal microbiota are extensive with at least 15,000-36,000 bacterial species. However, thanks to the new development in sequencing and molecular taxonomic methodologies, our understanding of the microbiota population composition, dynamics, and ecology has greatly increased. Intestinal microbiota play a critical role in the maintenance of the host intestinal barrier homeostasis, while dysbiosis, which involves reduction in the microbiome diversity, can lead to progression of inflammatory disorders, such as IBD and colorectal cancer. It is hypothesized that fingerprinting characterization of the microbiota community composition is the first step in the study of this complex bacterial ecosystem and a crucial step in the targeted therapy. Molecular fingerprinting of human gastrointestinal tract microbiota could be performed by different techniques including the semi quantitation, 16SrRNA, the DNA- microarray as well as other relatively new methods which were developed to study many complex bacterial ecosystems. These techniques provide individual data and profiles, using fast and sensitive tools for the high taxonomic level fingerprint of the human intestinal microbiota and provide estimation of the relative presence of the microbial target groups within each individual. Such personalized information serves as a remarkable and unprecedented opportunity to improve targeted medical treatment and probably develop strategies to prevent disease.

Colorectal cancer in patients with type 2 diabetes mellitus: a single-center experience.

Type 2 diabetes mellitus (T2DM) is associated with an increased risk of colorectal cancer (CRC). The aim of the study is to evaluate the prevalence of CRC in a cohort of Caucasian patients with T2DM and the association with other variables previously known to be related with increased risk of CRC. We retrospectively evaluated the data of 741 consecutive Caucasian patients with T2DM who underwent colonoscopic screening in our tertiary referral center. A control cohort of 333 patients with thyroid disease was selected to evaluate the difference in the incidence of CRC. At a median follow-up of 132.5 months (range 33.3-175.7), 67 cases of cancer (prevalence 9%) occurred; among these, 14 cases of CRC were reported (prevalence 1.88%) among the diabetic patients, while only two case (one of these was a CRC) (overall prevalence 0.006%, prevalence of CRC 0.003%) occurred in the control group; the difference between the prevalence of CRC was statistically significant (chi-square 4.21, p=0.04). The median duration of T2DM to CRC diagnosis was 168 months (range 12-768). At the univariate analysis, older age (p=0.001, r 0.138) and diabetes duration (p=0.001, r 0.138) were related to higher risk of cancer, while metformin seems to be protective towards cancer (p=0.07, r -0.098). In the subset of patients with CRC, the age (RR = 2.25; 95% CI: 0.30 - 17.31; p less than 0.001), the diabetes duration (RR = 1.93; 95% CI: 0.25 – 14.77; p = 0.001) and the sulphonylureas treatment (RR = 2.33; 95% CI: 0.78 – 7.38; p = 0.007) were independently correlated with CRC. In our study, the prevalence of CRC in the cohort of patients with T2DM was higher compared to that from the National Tumor Register in 2010 (0.5%). Furthermore, we could speculate that sulphonylureas may play a role in CRC carcinogenesis impairing the physiological insulin secretion.

Chaperone patterns in vernal keratoconjunctivitis are distinctive of cell and Hsp type and are modified by inflammatory stimuli.

BACKGROUND: Vernal keratoconjunctivitis (VKC) is a severe ocular allergy with pathogenic mechanism poorly understood and no efficacious treatment. The aims of the study were to determine quantities and distribution of Hsp chaperones in the conjunctiva of VKC patients and assess their levels in conjunctival epithelial and fibroblast cultures exposed to inflammatory stimuli. METHODS: Hsp10, Hsp27, Hsp40, Hsp60, Hsp70, Hsp90, Hsp105, and Hsp110 were determined in conjunctiva biopsies from nine patients and nine healthy age-matched normal subjects, using immunomorphology and qPCR. Conjunctival epithelial cells and fibroblasts were cultured and stimulated with IL-1ß, histamine, IL-4, TNF-α, or UV-B irradiation, and changes in Hsp levels were determined by Western blotting. RESULTS: Hsp27, Hsp40, Hsp70, and Hsp90 levels increased in the patients' conjunctiva, whereas Hsp10, Hsp60, Hsp100, and Hsp105 did not. Double immunofluorescence demonstrated colocalization of Hsp27, Hsp40, Hsp70, and Hsp90 with CD68 and tryptase. Testing of cultured conjunctival cells revealed an increase in the levels of Hsp27 in fibroblasts stimulated with IL-4; Hsp40 in epithelial cells stimulated with IL-4 and TNF-α and in fibroblasts stimulated with IL-4, TNF-α, and IL-1ß; Hsp70 in epithelial cells stimulated with histamine and IL-4; and Hsp90 in fibroblasts stimulated with IL-1ß, TNF-α, and IL-4. UV-B did not induce changes. CONCLUSIONS: VKC conjunctiva displays distinctive quantitative patterns of Hsps as compared with healthy controls. Cultured conjunctival cells respond to cytokines and inflammatory stimuli with changes in the Hsps quantitative patterns. The data suggest that interaction between the chaperoning and the immune systems drives disease progression.

Genetic ablation of macrohistone H2A1 leads to increased leanness, glucose tolerance and energy expenditure in mice fed a high-fat diet.

BACKGROUND/OBJECTIVES: In the context of obesity, epigenetic mechanisms regulate cell-specific chromatin plasticity, perpetuating gene expression responses to nutrient excess. MacroH2A1, a variant of histone H2A, emerged as a key chromatin regulator sensing small nutrients during cell proliferation and differentiation. Mice genetically ablated for macroH2A1 (knockout (KO)) do not show overt phenotypes under a standard diet. Our objective was to analyse the in vivo role of macroH2A1 in response to nutritional excess. METHODS: Twelve-week-old whole-body macroH2A1 KO male mice were given a high-fat diet (60% energy from lard) for 12 weeks until being killed, and examined for glucose and insulin tolerance, and for body fat composition. Energy expenditure was assessed using metabolic cages and by measuring the expression levels of genes involved in thermogenesis in the brown adipose tissue (BAT) or in adipogenesis in the visceral adipose tissue (VAT). RESULTS: Under a chow diet, macroH2A1 KO mice did not differ from their wild-type (WT) littermates for body weight, and for sensitivity to glucose or insulin. However, KO mice displayed decreased heat production (P<0.05), and enhanced total activity during the night (P<0.01). These activities related to protection against diet-induced obesity in KO mice, which displayed decreased body weight owing to a specific decrease in fat mass (P<0.05), increased tolerance to glucose (P<0.05), and enhanced total activity during the day (P<0.05), compared with WT mice. KO mice displayed increased expression of thermogenic genes (Ucp1, P<0.05; Glut4, P<0.05; Cox4, P<0.01) in BAT and a decreased expression of adipogenic genes (Pparγ, P<0.05; Fabp4, P<0.05; Glut4, P<0.05) in VAT compared with WT mice, indicative of augmented energy expenditure. CONCLUSIONS: Genetic eviction of macroH2A1 confers protection against diet-induced obesity and metabolic derangements in mice. Inhibition of macroH2A1 might be a helpful strategy for epigenetic therapy of obesity.

Modulation of MMP-2 and MMP-9 in Churg-Strauss syndrome respiratory mucosa: potential monitoring parameters.

Churg-Strauss (CSS) syndrome is rare and of unknown etiology. It is associated with vasculitis, blood eosinophilia and granulomatosis, and affects multiple organs and systems at various stages of the disease. Specific diagnostic and monitoring tests are not yet available. This study aims to assess the changes in MMP-2 and MMP-9 along with the histopathological alterations in two cases of CSS, as possible potential diagnostic and monitoring criteria. Two adult male patients were diagnosed with CSS in the otorhinolaryngology clinic in the University of Palermo, based on multiple clinical and histopathologic criteria. Biopsies of respiratory mucosa were taken after the consent of the patients, processed for routine histopathology and immunohistochemistry as well as quantitative polymerase chain reaction (qPCR). Similar biopsies were also taken from a non- CSS patient. The Assessment of MMP-2 and MMP-9 was performed using both immunohistochemistry and qPCR techniques. Histopathological alterations in the respiratory mucosa were consistent with vasculitis and granulomatous tissue formation, in addition to inflammatory cell infiltration with abundance of eosinophils. Immunohistochemistry assay performed on the samples derived from the two CSS patients showed a relative and remarkable increase of both MMP-2 and MMP-9 compared to controls. Such an increase was consistent with the qPCR results which depicted a significant increase between 20 and 30% for both MMP-2 and MMP-9, respectively. Since the secretion of MMPs is an essential step in angiogenesis, could these enzymatic factors be used as parameters to diagnose or monitor the evolution of CSS? The small number of samples analyzed in this study does not allow us to suggest a general statement correlating the increase in expression of MMP-2 and MMP-9 to the appearance or evolution of vasculitis; it is only speculative.

Estrogens control inflammation in experimental colitis.

There is now a wealth of experimental evidence indicating that the deficit in endogenous estrogen facilitates the onset of inflammation that can be antagonized by estrogen replacement therapy. This work investigated the role of estrogen in the control of intestinal inflammation in a panel of colitis models, focusing on the morphological changes, the activity of mast cells, the expression of cytokines (IL-1beta, IL-6, and TNF-alpha), fibronectin and reactive oxygen species. Two hundred adult male rats were divided into 4 groups: colitis was induced in Group I and Group II but only the latter was treated with estrogen; Group III received estrogen only, and Group IV saline. Colitis was induced in 4 models using: iodoacetamide; iodoacetamide + enteropathogenic E. coli; 2, 4, 6-Trinitrobenzene sulfonic acid; and dextran sulfate sodium salt. Macroscopic and microscopic evaluations of abdominal structures as well as molecular analysis were made on days 7, 14, 28 and 56. There was a significant improvement in the health condition of the estrogen-treated rats: the inflammation scores were reduced by at least 10-15%, the number of mast cells in the colon decreased by 30%, fibronectin expression was only 50% and reactive oxygen species decreased by 30%. In addition, there was a significant decrease in TNF-alpha, IL-6 and IL-1beta expression by about 25%. In conclusion, there was an improvement in the inflammatory status in all estrogen-treated groups through the duration of the experiment at all-time points. In addition, there was less tissue necrosis as depicted by less fibronectin and a marked antioxidant effect.

Lactobacillus casei and bifidobacterium lactis supplementation reduces tissue damage of intestinal mucosa and liver after 2,4,6-trinitrobenzenesulfonic acid treatment in mice.

Probiotics (PB) are living microorganisms that act as a commensal population in normal intestines and confer numerous beneficial effects on the host. The introduction of probiotics in the treatment of inflammatory bowel disease (IBD) prolongs remission. The aim of this study was to investigate the intestinal and hepatic effects of PB supplementation in an experimental IBD model in mice induced by 2,4,6-trinitrobenzene sulfonic acid (TNBS). In the first step of the experimental procedure, CD-1 male mice, 5 to 6 weeks old, were randomly divided into 3 groups and inoculated intrarectally with, respectively, saline, alcohol, or TNBS to assess the experimental IBD model. In the second step, mice treated, or not, with TNBS inoculation, were treated with PB (Lactobacillus Casei, Bifidobacterum Lactis) for 1, 2 or 3 weeks, on a daily basis. Large bowel (colon and rectum) and liver were processed for histological alterations, according to a scoring system. Large bowel was also assessed for apoptosis by TUNEL assay. TNBS induced, as expected, severe damage and inflammation in the large bowel, including nuclear alterations and apoptosis, and, to a lesser extent, to the liver. Administration of PB determined significant reduction of both histological alterations and apoptosis. PB administration in advance protects from inflammation. In conclusion, supplementation with Lactobacillus casei, Bifidobacterum lactis PB is able to ameliorate the colitis by reversing the histological changes caused by TNBS in mice. Experimentation in human subjects in needed to prove their efficacy in reducing histological alterations that may be present in subjects with IBD.

Probiotics, prebiotics and symbiotics in inflammatory bowel diseases: state-of-the-art and new insights.

Inflammatory bowel disease (IBD) consists of two distinct clinical forms, ulcerative colitis (UC) and Crohn's disease (CD), with unknown aetiology, which nevertheless are considered to share almost identical pathophysiological backgrounds. Up to date, a full coherent mechanistic explanation for IBD is still lacking, but people start to realize that the pathogenesis of IBD involves four fundamental components: the environment, gut microbiota, the immune system and the genome. As a consequence, IBD development might be due to an altered immune response and a disrupted mechanism of host tolerance to the non-pathogenic resident microbiota, leading to an elevated inflammatory response. Considering the available data arising from the scientific literature, here reviewed, in CD, a benefit of probiotics remains unproven; in UC, a benefit of probiotics remains unproven, even if E. coli Nissle 1917 seems promising in maintaining remission and it could be considered an alternative in patients intolerant or resistant to 5-ASA preparations; in pouchitis, small controlled trials suggest a benefit from VSL no. 3 in the primary and secondary prevention of pouchitis; in IBD-associated conditions, a benefit of probiotics remains unproven. However, well-designed randomized control clinical trials are necessary to understand the undoubted role of these agents in the management of gut physiology in health and disease.

Human dental pulp cell apoptosis: immunohistochemical study after applying orthodontic traction.

The aim of this study was to compare human dental pulp stress and programmed cell death after 3 and 6 months of orthodontic treatments by assessing the degree of apoptosis and related proteins. Human dental pulps were collected from twenty young patients orthodontically treated by Straight Wire technique. Samples were fixed, paraffin-embedded and processed for histology and immunohistochemistry using anti-heat shock protein 60 kDa (Hsp60), -caspase 3, -caspase 9, and -PCNA antibodies, as well as TUNEL reactions. Moreover, we performed immunoprecipitation for Hsp60 and caspase 3, and for Hsp60 and caspase 9, from paraffin extracted tissues. Increased levels of both caspases and Hsp60 occurred in 6-months treated samples; at the same time, we found increased levels of proliferating cell nuclear antigen and terminal deoxynucleotidyl transferase dUTP nick end labeling positive cells. Immunoprecipitation showed that Hsp60 forms a complex with both Pro-caspase 3 and Caspase 3, and this may accelerate Pro-caspase 3 activation, especially in the 6-months treated group. On the contrary, no complex between Hsp60 and Pro-caspase 9 was detected. The orthodontic tractions may be a cause of stress, apoptosis and proliferation in pulp tissue. These results suggest the need of further studies about the effects of long term orthodontic treatments on the dental pulp.

A comparative analysis of the products of GROEL-1 gene from Chlamydia trachomatis serovar D and the HSP60 var1 transcript from Homo sapiens suggests a possible autoimmune response.

Chlamydia trachomatis serovar D produces large quantities of HSP60-1 during infections, which accumulate inside the host cell inducing autoimmunity. We compare the aminoacid sequences of the human HSP60 with the bacterial counterpart to better elucidate how CTHSP60 may simulate HSP60 from human origin during infection and may induce an autoimmune response. As a result of the comparison we suggest several possible epitopes of the CTHSP60, which may induce autoimmunity.

CD1a down-regulation in primary invasive ductal breast carcinoma may predict regional lymph node invasion and patient outcome.

AIMS: CD1a is a molecule belonging to the highly conserved group of CD1 proteins. Its expression in dendritic cells is related to the presentation of tumour-derived glycolipid antigens to T cells and, consequently, the development of a successful antitumour response. The aim was to investigate the presence of CD1a+ cells in both primary tumours and lymph nodes (LN) of a series of 35 invasive ductal carcinomas by both immunohistochemistry and reverse transcription-polymerase chain reaction. METHODS AND RESULTS: CD1a antigen was more expressed in N0 than N1 breast cancer (P < 0.0001) in both primary lesions and LN metastases and correlated positively and significantly with oestrogen (ER) (P = 0.0025) and progesterone (P = 0.0226) receptor (PR) status, as well as CD4+ and CD8+ T-lymphocyte infiltration. CONCLUSIONS: This is the first report to show a link between CD1a+ mononuclear cells in breast cancer and in paired LN metastases. The positive and significant correlations between the number of CD1a+ cells and positivity of the primary tumour for ER and PR suggest a possible role for CD1a as a prognostic marker for breast cancer, raising the possibility that hormone receptor-positive breast cancer patients may have a better prognosis in the presence of greater dendritic cell infiltration.

p53 and Ki-67 expression in renal cell carcinomas of pregnant women and their correlation with prognosis: a pilot study.

In the present study, we reported two cases of renal cell carcinoma (RCC) diagnosed in pregnant women (Pt) that were submitted to radical nephrectomy, in both cases within the fourth month. The patients, after 13 and 3 years, respectively, did not show evidence of recurrent disease. We performed an immunohistochemical study on RCC specimens in comparison to seven age-matched controls (Cl). The panel of antibodies included Ki-67, p53, bcl-2, ER, PgR, PCNA, and IGF-1. We describe a difference in the expression of p53 and Ki-67. Specifically, p53 was highly expressed in RCC of both Pt but scarcely present or absent in Cl; by contrast, Ki-67 was hardly expressed or negative in RCC of both Pt, being commonly positive in Cl. These results may correlate with a good outcome of the disease in Pt. Although the limited number of cases did not permit any statistical evaluation, we postulate that these differences have not to be underestimated since they may disclose a correlation between pregnancy and biological behavior of tumoral disease. Further study may (dis)prove this hypothesis.

Upon oxidative stress, the antiapoptotic Hsp60/procaspase-3 complex persists in mucoepidermoid carcinoma cells.

Hsp60, a mitochondrial chaperonin highly conserved during evolution, has been found elevated in the cytosol of cancer cells, both in vivo and in vitro, but its role in determining apoptosis during oxidative stress (OS) has not yet been fully elucidated. The aim of the present work was to study the effects of OS on Hsp60 levels and its interactions with procaspase- 3 (p-C3) and p53 in tumor cells. NCI-H292 (mucoepidermoid carcinoma) cells were exposed to various concentrations of hydrogen peroxide (H2O2) for 24 hours. Cell viability was determined by Trypan blue and MTT assays. DNA damage was assessed by the Comet assay, and apoptosis was measured by the AnnexinV cytofluorimetric test. Exposure to increasing concentrations of H2O2 resulted in a reduction of cell viability, DNA damage, and early apoptotic phenomena. Hsp60, p-C3, p53, and p21 were assessed by Western blotting and immunocytochemistry before and after OS. Hsp60 and p-C3 were present before and after OS induction. Immunoprecipitation experiments showed an Hsp60/p-C3 complex before OS that persisted after it, while an Hsp60/p53 complex was not detected in either condition. The presence of wild type (wt) p53 was confirmed by RT-PCR, and p21 detection suggested p53 activation after OS. We postulate that, although OS may induce early apoptosis in NCI-H292 cells, Hsp60 exerts an anti-apoptotic effect in these cells and, by extension, it may do so in other cancer cells.

Atrial natriuretic peptide and CD34 overexpression in human idiopathic dilated cardiomyopathies.

Idiopathic dilated cardiomyopathy (IDCM) is a primary myocardial disease of unknown cause characterized by ventricular chamber enlargement with impaired contractile function. In familial forms of IDCM, mutations of genes coding for cytoskeletal proteins related to force transmission, such as dystrophin, cardiac actin, desmin, and delta-sarcoglycan, have been identified. Here, we report the data of a retrospective investigation carried out to evaluate the expression of atrial natriuretic peptide (ANP), CD34, troponin T and nestin in the myocardium of patients affected with IDCM. Formalin-fixed and paraffin-embedded consecutive tissue sections from the ventricular wall of 10 human normal hearts (NH) following forensic autopsy and 22 IDCM (living explanted hearts) were studied using primary monoclonal antibodies against ANP, CD34, troponin T and nestin by immunohistochemistry. Myocardial fibers were counted independently by three pathologists. Statistics included analysis of variance, log-rank test for Kaplan-Meier analysis, and kappa assessment for intra- and inter-observer variability. ANP and CD34 were significantly overexpressed in IDCM compared to NH (p<0.05). Conversely, troponin T and nestin expression levels did not show significant variation. Inter-observer kappa statistics showed a value of 0.87 and intra-observer kappa statistics a value of 0.98. Evaluation of the marker distribution in the myocardium of patients with IDCM CD34 expression curve was similar to that of troponin T (p<0.0001), although two groups could be identified. Patients with a difference of more than 20 myocardial fibers in expression of CD34 and troponin T had a somewhat less favorable survival although the difference was not significant. The analysis of cells positive for troponin T resulted in a similar number of cardiac fibers between NH and IDCM. This is in agreement with cardiac enlargement present in IDCM, which is due to ventricular dilatation rather than increased number of myocytes. Moreover, the expression of nestin, a marker of activation of myocardial precursors, did not change either, and this may confirm that there are no hyperplastic phenomena in the IDCM pathogenesis. The increase in ANP-positive cells in IDCM could be a consequence of neurohormonal activation due to a decline in the impaired myocyte contractility. Furthermore, since it was already shown that ANP could be important in the control of vascular remodeling, we postulated that the increase in CD34-positive cells might be functionally correlated with the increase in ANP production. Differential expression of CD34 and troponin T might be used in future studies to evaluate their prognostic value.

Increased expression of titin in mouse gastrocnemius muscle in response to an endurance-training program.

Titin, a sarcomeric giant protein, plays crucial roles in muscle assembly, elasticity and stability. Little is known about titin adaptation to endurance exercise. We studied the effects of endurance training on titin expression in mouse gastrocnemius muscles (MGM). Sixty-three ten-week-old male Swiss mice were divided into seven groups. Four groups were composed of untrained control animals (C0, C15, C30, C45) instead the other three included mice trained for 15 (T15), 30 (T30) and 45 (T45) days by treadmill. The training protocol was mainly aerobic, characterized by moderate-intensity, rhythmic and continuous exercises. Titin expression was determined by immunohistochemistry on MGM sections. Results revealed a significant reduction in body weight of the T45 mice and a significant increase in titin expression (% titin immunoreactivity median [range] = 41.11 [20-60] vs. 30.00 [10-50]). It is postulated that the up-regulation of titin expression is an adaptative mechanism to increase muscle elasticity and stability in response to the high number of stretch-shorten cycles during endurance training. Such a mechanism may be important for minimizing muscle energy consumption and improving performance during running.

Adult stem cells: the real root into the embryo?

During embryonic development, a pool of cells may become a reserve of undifferentiated cells, the embryo-stolen adult stem cells (ESASC). ESASC may be responsible for adult tissue homeostasis, as well as disease development. Transdifferentiation is a sort of reprogramming of ESASC from one germ layer-derived tissue towards another. Transdifferentiation has been described to take place from mesoderm to ectodermal- or endodermal-derived tissues and viceversa but not from ectodermal- to endodermal-derived tissues. We hypothesise that two different populations of ESASC could exist, the first ecto/mesoblast-committed and the second endo/mesoblast-committed. If confirmed, this hypothesis could lead to new studies on the molecular mechanisms of cell differentiation and to a better understanding of the pathogenesis of a number of diseases.

Research of cardiomyocyte precursors in adult rat heart.

Recent reports supported the existence of stem cells in adult hearts. However, phenotype and localization of these cells have not been completely described and it is unknown if cardiac regenerative potential differs from one subject to another. The aims of our work were to identify different populations of cardiac stem cells by the analysis of specific markers and to evaluate the expression variability of these markers in 12 adult rat hearts. The expression of CD9, taube nuss and nanog suggests the presence of stem cells from the earliest stages of embryogenesis in adult myocardium. Their different expression could be associated to the degree of stem cell differentiation. CD34 and c-Kit antibodies were used to detect stem cells committed to one or more specific tissue lineages and we found a strong immunoreactivity for CD34 exclusively in the endothelial cells and a low positivity for c-Kit in the interstitium and next to the vessels. Moreover, as c-Kit expression highly differed within all examined hearts, we suggest that cardiomyogenic potential is different among the various subjects. Undifferentiated cells with myogenic-committed phenotype expressing GATA-4 and nestin were found, respectively, in the interstitial and myocardial cells and in few interstitial cells. Therefore, the physiologic turn over of cardiomyocytes may occur in adult hearts as it has been shown in many others organs. The study of myogenic potential could be important to identify markers specific of stem cells in in vivo adult myocardium that may be used to purify these cells and evaluate their regenerative ability.