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Discusses the evidence supporting the contention that aberrant crypt foci (ACF) are precursors of colon cancer in rodents and in humans. Cell and crypt dynamics in ACF; Cell proliferation and apoptosis of normal colorectal mucosa; Identification of colon carcinogens and chemopreventive agents; Mechanisms of genetic control; Histology, biochemical, cell kinetics and genetic alterations in ACF.

Matrix metalloproteinases (MMPs) have been well characterized for their ability to degrade extracellular matrix proteins and, thus, they have been studied to elucidate their involvement in both tumor development and progression. In the present study, attention was focused on MMP-15 and MMP-19, two less known members of the MMP family. The expression profile of MMP-15 and -19 was assayed in samples of normal colorectal mucosa, microadenomas and cancer using confocal analysis, western blotting and quantitative reverse transcription polymerase chain reaction (qRT-PCR). Both qRT-PCR and western blotting showed that MMP-15 and MMP-19 appeared to be upregulated during colorectal tumorigenesis, with different expression patterns: MMP-15 expression level increases from normal mucosa to microadenomas, with a reduced level in cancer with respect to microadenomas; the semiquantitative immunofluorescence analysis showed a stromal localization of this protein in the early phases of neoplastic transformation. Increasing amount of MMP-19 mRNA and protein levels were observed in the progression of colonic lesions; MMP-19 staining increased in the normal mucosa-microadenoma-carcinoma sequence. Such different expression patterns, are probably due to the different roles played in colorectal tumorigenesis by these two molecules. Conflicting data on the role of these proteins in tumor progression have been reported, thus, an improved understanding of the biological roles of MMPs, in particular the lesser known members such as MMP-15 and 19, in colorectal cancer may lead to a re-evaluation of the use of MMP inhibitors and suggests the need of integrated translational studies on MMP expression patterns.

The flat foot in childhood is a condition frequently observed in orthopedic practice but it is still debated when and in which patients surgical corrective treatment is appropriate; recently, the application of poly-L-lactic-acid (PLLA) screws was proposed. The present study investigates a group of 33 patients treated with PLLA expansion endorthesis in order to evaluate the deformity correction. Clinical and radiological outcomes in patients were correlated with: a) morphological characterization of screws both before and after being removed from patients, when necessary; b) histological and bio-molecular evaluation of degradation processes of the implants, focusing attention on the correlation between the cellular cohort involved in inflammatory reaction and the bio-absorption degree of PLLA screws. Deformity correction was mostly achieved, with minimal need of screw removal; the results obtained clearly show the occurrence of chronic rather than acute inflammation in removed screw specimens. At the histological level, after biomaterial implantation, the sequence of events occurring in the surrounding tissues ultimately ends in the formation of foreign body giant cells (FBGCs) at the tissue/material interface; but the mechanisms which influence the fate of screw implants, i.e. the resolution of acute inflammation rather than the progression towards chronic inflammation, are of crucial importance for biodegradable materials like "polylactic acid". In fact, the FBGC response ensures a long-term mechanism which eliminates the foreign material from the body, but at the same time the implications of prolonged FBGC responses, which generate negative side effects, could significantly impede the healing progress.

This study investigated the potential of amniotic fluid stem cells (AFSCs) to synthesize mineralized extracellular matrix (ECM) within different porous scaffolds of collagen, poly-D,L-lactic acid (PDLLA), and silk fibroin. The AFSCs were initially differentiated by using an osteogenic medium in two-dimensional culture, and expression of specific bone proteins and the physiologic mineral production by the AFSCs were analyzed. In particular, during differentiation process, AFSCs expressed proteins like Runt-related transcription factor 2 (Runx2), Osterix, Osteopontin, and Osteocalcin with a sequential expression, analogous to those occurring during osteoblast differentiation, and produced extracellular calcium stores. AFSCs were then cultured on three-dimensional (3D) scaffolds and evaluated for their ability to differentiate into osteoblastic cells in vivo. Stem cells were cultured in vitro for 1 week in collagen, fibroin, and PDLLA scaffolds. The effect of predifferentiation of the stem cells in scaffolds on the subsequent bone formation in vivo was determined in a rat subcutaneous model. With the addition of a third dimension, osteogenic differentiation and mineralized ECM production by AFSCs were significantly higher. This study demonstrated the strong potential of AFSCs to produce 3D mineralized bioengineered constructs in vivo and suggests that fibroin may be an effective scaffold material for functional repair of critical size bone defects.

Human colorectal microadenomas are considered the earliest detectable premalignant lesions in the colon. They can be identified as aggregates of enlarged crypts with thicker epithelial linings and elongated luminal openings on the colonic mucosal surface after methylene blue staining and observation under a dissecting microscope. Multiple lines of evidence suggest that a central role in neoplastic development is played by the inhibition of apoptosis, followed by disruption of DNA repair. Understanding the early mechanisms of colorectal carcinogenesis may help develop new approaches of colorectal cancer prevention and treatment. The aim of the present study was to quantify poly-ADP ribose polymerase 1 (PARP-1)-positive cells and to evaluate apoptotic control mechanisms through Caspase-3 active and Bcl-2 protein expression in human microadenomas and in normal colorectal mucosa using immunofluorescence techniques coupled with confocal microscopy and immunoblot experiments. The mean percentage of PARP-1-positive epithelial cells was 3.0 +/- 0.37% (SD) and 15.67 +/- 0.40% in microadenoma and in normal mucosa, respectively. Proteins involved in programmed cell death were differently expressed in microadenoma and in normal mucosa. Indeed, by semiquantitative immunofluorescence analysis, confirmed by Western blot, microadenoma showed low levels of Caspase-3 active and high levels of Bcl-2 expression, whereas the opposite was true for normal colorectal mucosa [corrected]. In the stroma of normal colorectal mucosa, fibroblast-like cells and neutrophils were the cells that underwent apoptosis to a greater extent. In conclusion, malfunction of the control mechanisms of programmed cell death seems present in the early stages of colorectal cancer development.

Chronic mucosal inflammation is considered a risk factor for colorectal cancer. Neutrophils are a major source of oxidants, whereas cyclooxygenase 2 (COX-2) and Hypoxia Inducible Factor-1alpha (HIF-1alpha) protein expression levels are increased in inflammatory and malignant lesions. The main purpose of the present study was to evaluate myeloperoxidase (MPO) positive cell infiltration, COX-2 and HIF-1alpha protein expression in colorectal carcinogenesis, especially in its early phases, using immunohistochemistry and immunofluorescence confocal microscopy techniques. MPO, COX-2 and HIF-1alpha proteins were expressed at higher rates in the normal colorectal mucosa of patients with inflammatory bowel diseases and colorectal tumours than in patients with normal colonoscopy. A gradual increase in COX-2 and HIF-1alpha protein expression was observed in dysplastic aberrant crypt foci, adenomas and carcinomas, showing a strong relation to dysplasia. In conclusion, the present study supports the hypothesis of a key role of inflammation in malignant transformation of colorectal mucosa. The evaluation of some early markers related to inflammation in the mucosa of the large bowel may serve as potential tool for prognosis and therapeutic strategies.

Bone fractured healing is a specialized wound-healing response that leads to regeneration without scar restoring its own ability of mechanical loading. The four stage classification of fracture healing process, by John Hunter, is still the frame in which the new biological and molecular findings settle in.Nowadays the fracture healing is pictured like a playground where growth and differentiation factors, hormones, cytokines, and extracellular matrix play with bone and cartilage forming primary cells and muscle mesenchymal cells in a well orchestrated series of biological events. The ongoing knowledge of cellular and molecular interactions between blood vessels and bone cells shows great promise to enhance fracture management and the unsuccessfull process of bone healing.

MATER (Maternal Antigen That Embryos Require) is an oocyte-specific protein dependent on the maternal genome and required for early embryonic development. The gene products expressed in oocytes play important roles in folliculogenesis, fertilization and pre-implantation development. The aim of this study was to characterize the localization and distribution pattern of the human MATER protein during follicular development and after ovulation, to determine its functional role. Immunocytochemistry experiments coupled with confocal and electron microscopy analysis were carried out to determine the ultrastructural localization of MATER in human ovarian tissue and in isolated oocytes, obtained during IVF procedures. Human cumulus cells were cultured, with or without cycloheximide, to confirm endogenous biosynthesis of the protein. Human MATER is detectable at the onset of the follicular maturation process, suggesting this protein has a role at earlier stages in the human compared with other mammalian species. The presence of MATER is specific to the oocyte and follicular cells that, during maturation, are spatially and functionally associated with the oocyte. The nuclear, nucleolar and mitochondrial localization hints at a possible role in RNA processing and the metabolic activity of the cell.

Purpose: Extracorporeal shockwave lithotripsy (SWL) is one of the most common treatments for urinary stones. Despite technological improvements, it may cause side effects varying from minor reversible microscopic damage to severe large renal hematomas. The aim of our experimental study is to assess the efficacy of inosine in avoidance of acute renal damage after SWL., Materials and Methods: We used 25 Wistar rats that had previously had left nephrectomy. The rats were divided into three groups: group A consisted of 10 rats undergoing renal SWL; group B consisted of 10 rats that received adjunctive treatment with IP injection of inosine 40 minutes before SWL; and group C consisted of 5 rats that served as controls. N-acetylglucosaminidase (NAG) and lactate dehydrogenase (LDH) concentrations were evaluated 24 hours before and 24 hours after SWL. All the rats were subsequently sacrificed (4 rats in group A and 4 in group B at 48 hours post-SWL, and the remaining rats were sacrificed 30 days post-SWL). Renal tissue was submitted to histologic and electron microscopic examination to assess early and late alterations., Results: NAG and LDH values were significantly increased after SWL in group A (P<0.001), while no significant NAG and LDH differences were detected in group B (P<0.16). Early histologic examination revealed a considerable amount of cellular degeneration in group A with ultrastructural vacuolization and disruption of lysosomal membranes; the tubular features and cellular structures appeared to be well preserved in group B. No late histologic alterations were evident in any of the specimens., Conclusions: Inosine is helpful and protective in the prevention of early microscopic damage to renal parenchyma due to SWL.

Recent improvements in techniques in clinical assisted reproduction have led to an increased interest in the cryopreservation of human ovarian tissue as a way of preserving fertility and ovarian steroidogenic activity in young cancer patients. Acceptable follicular survival in frozen-thawed human ovarian tissue has generally been reported. Since a 0.3 mol/l sucrose concentration in cryopreservation solutions evidently increases human oocyte survival after cryopreservation, the aim of this study was to observe the effect of sucrose concentrations of 0.2 mol/l and 0.3 mol/l on human ovarian tissue survival after thawing. Ovarian cortical slices from 10 patients, 22-36 years of age, were cryopreserved slowly using 0.2 mol/l or 0.3 mol/l sucrose with 1,2-propanediol (1.5 mol/l) as the cryoprotectants. Light and electron microscopy were used for the histological analyses. Results showed that both treatments produced an increase in damaged cells; however, the use of 0.3 mol/l sucrose showed a smaller percentage of damaged germ cells than 0.2 mol/l sucrose, and therefore was less detrimental to the thawed ovarian tissue. However as the damage occurred principally in the stroma and follicular cells rather than in the oocytes, the suitability of these cryopreservation protocols must be further evaluated prior to considering the use of stored ovarian cortex for autografting after thawing.

Adenomatous polyposis coli (APC) is a tumor suppressor gene whose main function is the destabilization of beta-catenin, a key effector of the Wnt signaling pathway. This gene is defective in familial adenomatous polyposis (FAP), a dominantly inherited disease, but inactivation of APC has been reported also in most sporadic colorectal tumors and it is considered an early event in colorectal tumorigenesis. The aim of the present study was to evaluate the intracellular ultrastructural distribution of beta-catenin and APC proteins in epithelial cells of normal colorectal mucosa, aberrant crypt foci (ACF, an early premalignant lesion) and cancer. We used the immunogold electron microscopic method to identify both proteins. Normal colonic epithelial cells showed a strong membranous expression of beta-catenin and lacked cytoplasmic and nuclear expression. Normal cells showed APC localization pattern characterized by diffuse nuclear expression and along the plasma membrane. In ACF and in carcinoma an absent or reduced membranous expression of beta-catenin was associated with an increased nuclear and cytoplasmatic expression. In aberrant crypt foci and carcinoma, APC was evident inside the nucleus and at the level of cell-cell junctions, but it was decreased in the cytoplasm. This method allowed the accurate localization of proteins of the Wnt signaling pathway in the early steps of colorectal carcinogenesis. The similar pattern of subcellular distribution of APC and beta-catenin in dysplastic ACF and colorectal cancer suggests that ACF are precursor lesions of sporadic and FAP-associated colorectal carcinoma.

During mammalian oogenesis, some processes involve proliferation and others drastic reduction of germ cells. This study reports on the role played by two hormones, estradiol monobenzoate and oxytocin, in the control of the number of germ cells in the neonatal mouse ovary. Female neonatal mice were treated with doses ranging between 0.1 and 1 microg/mouse of estradiol monobenzoate or oxytocin and sacrificed at 5 days of postnatal age. The results showed that in the animals treated with estrogen, follicular development was more advanced than that of controls. Further the number of germ cells in apoptosis was drastically reduced. In the animals treated with oxytocin, the follicular development was arrested at the stage of primary follicles. In addition, the number of apoptotic germ cells increased if compared with that of the controls.

Intraabdominal sarcomas are rare tumours usually diagnosed at an advanced stage. These lesions at presentation are bulky and symptoms are often related to pressure effects on adjacent organs. This case report describes a rare presentation of a small bowel leiomyosarcoma whose initial presentation was free haemorrhage into the abdominal cavity and concomitant liver metastases. This case report also demonstrates that, even with such a rare presentation, an aggressive surgical approach is indicated in this type of tumour and helps a patient with advanced disease to live a few disease-free months with a good quality of life.

Background: The aim of this study is to evaluate the biocompatibility of Angimesh mesh (polypropilene) in rats, usually used to replace or to strengthen the abdominal fasciae., Methods: We made an abdominal longitudinal incision of skin and muscles in 20 rats was carried out and two muscular semilunae removed. The incision was occluded with Angimesh mesh fixed by ethilcyanoacrilate glue (first group of rats) or with suture stitches (second group of rats). The animals were sacrificed after 80 days and the stability of the mesh and the presence of endoperitoneal adhesion were evaluated macroscopically, and microscopically the fibrogenesis and inflammation answer., Results: Two rats of the first group and seven of the second group died before 30 days. The mesh was more steady when fixed by suture. Adhesion in the contact sites between the mesh and the peritoneum was found. Histology did not show any inflammation reaction but showed a fibrogenic answer., Conclusions: The cyanoacrilate non-toxicity has been confirmed also in this application. Angimesh mesh showed good biocompatibility and resulted ideal for the synthesis of large abdominal resections.

Apoptosis is an active form of cell death characterized by a series of morphological changes that become particularly evident at the ultrastructural level. The majority of ovarian germ cells undergo degeneration during prenatal and reproductive life and only in recent studies has it been demonstred that this drop is due to an apoptotic process. We evaluated this process during human oogenesis in prenatal life and we studied the ultrastructural changes that occur in apoptosis in various phases of the meiotic process. From our observations it is clear that apoptosis involves two main phases of the meiotic process: an earlier one concerning the oogonia and oocytes in the preleptotene stage, and a later one that mainly concerns the oocytes in the pachytene stage.

Background: Aberrant crypt foci (ACF) are clusters of morphologically altered crypts which can be observed by light or stereomicroscopy on the mucosal surface of the colon after staining with methylene-blue. They probably represent one of the earliest events in human colorectal carcinogenesis. The main purpose of the present study was to observe the surface features of aberrant and normal colonic crypts in humans using scanning electron microscopy (SEM) in order to find and measure differences between aberrant and normal., Materials and Methods: Fifteen mucosal specimens containing ACF and 8 with normal mucosa taken from patients operated on for colon cancer were observed under a scanning electron microscope., Results: By SEM ACF were easily observed on the mucosal surface, because they showed a well defined border and were elevated on the mucosal surface. Under higher magnification luminal openings of aberrant crypts had a larger overall average diameter than normal (37.6 microns +/- 13.5, mean +/- SD, vs 15.9 microns +/- 4.9, P = 0.001), though when crypt multiplicity of ACF (number of crypts per ACF) was higher, the diameter of luminal openings tended to be smaller and similar to those of normal crypts, with weak negative correlation between crypt multiplicity of ACF and mean diameter of aberrant luminal openings (r = 0.27). Finally, the mucosal surface among aberrant crypts was flattened because of a loss of microvilli. in conclusion, scanning electron microscopy allows a better definition of the topological features of aberrant crypt foci than light or stereomicroscopy.

Objective: To assess the effects of a non-elemental liquid diet on nutritional state, composition of bowel flora, intestinal translocation, and pulmonary infections after small bowel transplantation in pigs., Design: Prospective randomised experiment., Setting: Teaching hospital, Italy., Material: 32 female Large White pigs., Interventions: Group 1 (n = 6) underwent small bowel transplantation, were treated with immunosuppression, and fed on commercial chow. Group 2 (n = 6) were treated similarly except that they were fed with an enteral feed through a tube gastrostomy starting on day 4 postoperatively. Group 3 (n = 6) were treated similarly to group 1 except that they had no immunosuppression, and Group 4 (n = 6) underwent orthotopic small bowel autotransplantation; 8 further pigs underwent a sham operation only to act as controls., Main Outcome Measures: Signs of rejection, graft-versus-host-disease, luminal bacterial overgrowth, bacterial translocation, pneumonia, and the pigs' nutritional state., Results: All animals in group 3 showed signs of acute rejection. There was appreciable overgrowth of aerobic and anaerobic bacteria in all three groups after allotransplantation compared with controls. The counts of anaerobic bacteria were significantly lower in group 2 (enterally fed animals) compared with those given free access to commercial chow [mean (SD) 2.81 (1.39) log CFU/cm2 compared with 4.80 (1.65), p = 0.047]. Bacterial translocation developed to a similar degree after autografts and allografts and pneumonia developed in fewer animals after enteral feeding (1/6) than after conventional feeding (5/6) but the difference was not significant (p = 0.08, odds ratio 25.0, 95% confidence interval of odds ratio 1.20 to 521.13). Enterally fed animals also lost less weight than conventionally fed animals [2.32 (1.23) kg compared with 4.53 (1.74), p = 0.016]., Conclusions: Enteral feeding for up to a month slightly reduced the rate of pneumonia and resulted in a better nutritional state in pigs after small bowel transplantation. It had no effect on luminal bacterial overgrowth or translocation.

Pancreatic cancer has a dismal prognosis also after resection with a 5 years' survival of about 5% in operated patients. The main clinical issue in patients with a malignant tumour is to identify the ones that would benefit from a surgical treatment. Resectability of pancreatic cancer has not an absolute value and the possible advantages in terms of prognosis and quality of life should be balanced with surgical mortality and morbidity. For this reason the management of this disease involves a multidisciplinary approach and the surgeon should join with the other specialists in experienced oncology centers. En exhaustive evaluation of the following prognostic factors should be made pre and intra-operatively to better define life expectancy with or without resection: Histotype: endocrine tumours and cystadenocarcinoma have, in general, a better prognosis, Staging: JPS classification has a better prognostic value if compared to the UICC. Completeness of the resection. Biological characteristics of the tumour. The main variables to be considered for the exeresis are: Size and local growth of the tumour (also considering the involvement of vessels, retroperitoneum and pancreatic capsule). Liver or peritoneal metastases: for this laparoscopy has a key role for staging. Histologic confirmation: differential diagnosis with chronic pancreatitis is sometimes difficult and every attempt should be made to have a pre-operative histology. Vascular invasion is one of the main contraindications to surgery and an exhaustive evaluation of vascular involvement should be considered mandatory. Lymph nodal involvement, in general, represents a negative prognostic factor even if Japanese authors claim that a radical resection can be performed in case of positive nodes in the peripancreatic area, if a complete lymphadenectomy is carried out.

Alterations in the luminal microflora and increased intestinal translocation have been reported to occur following experimental and clinical small bowel transplantation (SBT). Selective intestinal decontamination (SID) has been used to prevent luminal overgrowth and bacterial translocation. Despite the wide use of SID in clinical SBT, there are no data supporting its usefulness in this situation. Thus, the aim of this investigation was to examine the effects of cyclosporine A (CsA) and SID upon bacterial overgrowth and translocation in a swine model of SBT. Nineteen Large White female pigs weighing 30 +/- 2 kg underwent a total orthotopic SBT and were randomly allocated to one of the following experimental groups as follows: Group 1 (No. 8) CSA 25 mg/kg body weight (b.w.)/day administered subcutaneously and Cefazolin 2 g/day im. Group 2 (No. 6) received the identical immunosuppression but the Cefazolin 2 g/day im was discontinued on the 5th Postoperative Day (pod) and switched to a SID regimen consisting of Vancomycin, 1 g, Nystatin, 500,000 IU, Colistin, 1,500,000 IU, and Tobramycin, 100 mg, given through a gastrostomy tube. Group 3 (No. 5) received no immunosuppression but antibiotic consisting of Cefazolin 2 g im/day. Group 4 (No. 7) underwent a small bowel autotransplantation. Group 4 received SID as in group 2 but no immunosuppression was given. Finally, 17 normal animals were sham-operated and were used as normal controls (N group). The animals in groups 1, 2, and 4 were sacrificed on the 29th pod. Those in group 3 were sacrificed on the 7th pod.(ABSTRACT TRUNCATED AT 250 WORDS)

Objective: To examine the effects of two immunosuppressant regimens on composition of the bowel flora and rate of translocation after transplantation of the small bowel in pigs., Design: Randomised controlled study., Setting: University hospital, Italy., Material: 35 female Large White pigs., Interventions: 9 Animals were not operated on (normal controls). 19 Animals underwent total orthotopic small bowel allotransplantation and were then randomised to receive: group A (n = 8) cyclosporin A 25 mg/kg subcutaneously and cephazolin 2 g intramuscularly daily; group B (n = 6) 15-deoxyspergualin (15-dos) 3 mg/kg for 7 days then 1.5 mg/kg, cephazolin 2 g intramuscularly daily for 4 days then selective intestinal decontamination with colistin 1.5 million U, tobramycin 100 mg, vancomycin 1 g, and nystatin 500,000 U daily; and group C (n = 5) cephazolin 2 g intramuscularly daily for 8 days. A further group (D, n = 7) underwent orthotopic autotransplantation and received the same antibiotic and selective decontamination regimens as group B. Animals in group C were killed on day 8, and the rest on day 29., Main Outcome Measures: Signs of rejection, graft versus host disease, luminal overgrowth, and evidence of translocation to mesenteric lymph nodes., Results: All animals in group C, and 2 in group B, showed signs of acute rejection. There was a significant overgrowth of both aerobic and anaerobic bacteria in all 3 groups after allotransplantation compared with normal controls. Bacterial translocation was similar in autografted and allotransplanted animals. Mesenteric lymph nodes were colonised in 4/9 controls, 7/8 in group A, 4/4 in group B, 5/5 in group C, and 7/7 in group D., Conclusion: Neither cyclosporin A nor 15-dos prevented luminal overgrowth or bacterial translocation to mesenteric nodes up to one month after operation. The rate of translocation was similar in autotransplantation and allotransplantation, suggesting that non-immunological factors (for example, denervation and interruption of lymphatics) may have a role in these alterations.