Neoadjuvant oxaliplatin and 5-fluorouracil with concurrent radiotherapy in patients with locally advanced rectal cancer: a single-institution experience.

PURPOSE: The aim of this study was to evaluate the rate of pathological response (PR), disease control and safety of neoadjuvant chemotherapy using oxaliplatin (OX) and 5-fluorouracil (5-FU) with concurrent radiotherapy for treating locally advanced rectal cancer. MATERIALS AND METHODS: Between November 2002 and December 2010, 90 patients with locally advanced rectal cancer treated with neoadjuvant chemoradiotherapy (CRT) were retrospectively analysed. All patients underwent preoperative radiotherapy (45 Gy in 1.8-Gy fractions) with concurrent OX (80 mg/m(2) i.v., day 1) and a 120-h continuous infusion of 5-FU (1,000 mg/m(2) per day). Surgery was performed within 6 weeks after completion of CRT treatment. RESULTS: Complete pathological response was obtained in six patients (6.7%), and 39 (43.3%) had their disease downstaged. The median follow-up period was 4.7 years (6 months to 9 years). Local recurrence occurred in two patients (2.2%), one of whom developed also liver metastases. Distant metastases not associated with local relapse occurred in 23 (25.6%) patients. Overall (OS) and disease-free (DFS) survival were 62.9% and 52.8%, respectively. CRT was well tolerated, with only one grade 3 (1.2%) haematological toxicity (neutropaenia). CONCLUSIONS: Neoadjuvant systemic chemotherapy based on OX and 5-UC associated with radiotherapy is well tolerated, with good results in terms of pathological response, disease control and survival, in rectal cancer patients.

[Focus on risk assessment in health environments: results and perspectives of a multicenter working group]. / Focus sulla valutazione del rischio negli ambienti sanitari: risultati e prospettive di un gruppo di lavoro multicentrico.

The hospital risk assessment (VdR) is certainly a relevant issue concerning the activities of prevention for the health of healthcare workers in relation to biological risk. The aim of this paper is to provide an up-date of the issue, based on the suggestions of recent literature about the rules ratified by the new legislative decree and data supplied by the Group of 10 Hospitals participated in this multicenter study. From the analysis of data on healthcare settings (HCS) participating in the project the following considerations can be formulated: i) All HCS considered VdR from biological agents. The method recommended in the Guidelines SIMLII 2005 is the most followed ii) To grading the risk, the use of invasive procedures for carrying out the analysis results is a necessary element iii) the operators classified as exposed to biological risk, and therefore subject to health surveillance, represent almost all of workforce in 7 out of 10 HCS. The subgroup believes that VdR must be conducted in close collaboration with the occupational physician and should represent a worthwhile investment with spin-off character on prevention, decision making, empowering. The presence of environmental requirements and organizational procedures should be considered, so that HCS is enabled for an effective risk management, without which risk assessments cannot be performed. The method of VdR mentioned in the guidelines MLIS 2005, besides being the most widely used by the company participating in the study, still has practical reasons and opportunities to justify its use. The HCS group felt the need to propose an implementation of the definition of invasive procedures and EPP, together with individual assessment. Flexibility was suggested in identifying different levels of risk with the involvement of occupational physicians, especially in the presence of EPP, also in order to plan content and frequency of health surveillance.

[Tuberculosis. Focus on risk assessment and health surveillance in health workers: results and perspectives of a multicenter working group]. / La tubercolosi. Focus sulla valutazione del rischio e la sorveglianza sanitaria dei lavoratori della sanità: risultati e prospettive di un gruppo di lavoro multicentrico.

INTRODUCTION: Tuberculosis (TB) is still a threat for healthcare workers (HCW), due to the non decreasing incidence, the spread of drug-resistance, the introduction of new tests for the screening, the relevant costs of surveillance of exposed subjects. These issues implicate a revision of activities to prevent TB in health-care settings. METHODS: A multidisciplinary working group, led by occupational physicians, examined the activities to prevent TB performed in 9 Italian hospitals and reviewed the literature, with the aim to formulate evidence-based procedures. RESULTS: In the considered hospitals, 23.000 HCW are classified as exposed to TB, out of 32.000 HCW exposed to biological risks; yearly, about 6000 subjects are screened for preventive, periodical or post-exposure surveillance and 110-130 chemoprophylaxis are prescribed. A high proportion of HCW (54-75%) refused or interrupt to assume the drugs. In the period 2004-2008, 14 occupational TB were diagnosed (9/100.000 HCW exposed to biological risks). DISCUSSION: Critical issues are the availability of a specific, written TB control plan, including risk assessment, protocols for identifying, evaluating, managing infectious TB patients, health surveillance, education programs, specifically addressed to increase Standard Precaution adoption and compliance to the screening and to adequate risk perception. Risk assessment identify HCW to be included in TB testing (characterized by low positive predictive value), unrecognized TB and environmental control needed; TB risk classification should include no more than 3 or 4 classes and performed by assessing the issues suggested in the Italian guideline. Tubercolin skin test should be used for HCW screening, adding in vitro test in specific circumstances (for example, skin test positivity in BCG vaccinated HCW); the frequency of the screening should not exceed 2 years. Periodical revision of preventive activities should follow up to date scientific literature and need appropriate data computing.

[Focus on coverage and promotion of anti influenza vaccine in health workers: results and perspectives of a multicenter working group]. / Focus so copertura e promozione della vaccinazione antinfluenzale nei lavoratori della sanità: risultati e prospettive di un gruppo di lavoro multicentrico.

INTRODUCTION: The influenza illness is a concern for health care workers (HCW) due to the potential nosocomial transmission and sickness absenteeism. Immunization and Isolation Precautions might be effective preventive measures. AIMS: To formulate recommendations on vaccination in healthcare settings. METHODS: A multidisciplinary working group, led by occupational physicians (OP), examined the information on seasonal influenza immunisation campaign in 9 Italian hospitals in the period 2005-2009 and reviewed scientific evidence. RESULTS: Many health organizations recommend vaccination of HCW. The literature shows that seasonal influenza vaccination of healthy adult have a modest effect in reducing work day lost; there is no evidence that it affects transmission or it prevents the disease in elderly residents. These observations might be conditioned by methodological limitations. Further studies are required to avoid the risk of bias and in pediatric settings. The rate of flu vaccination among HCW is widely variable and it depends on individual risk perception and information about efficacy and side effects. In the considered hospitals, in the five-years period the vaccination rate ranged between 0 and 29%: the median value was 16-17% in 2005, 2008 and 2009 (only against H1N1 influence), 11% and 13% in 2007 and 2006 respectively. OP participation in the vaccination campaign seems to increase the immunization rate. DISCUSSION: Seasonal influenza immunization of HCW might be effective. We recommend to formalize written procedures in health care settings, to perform data computing and to periodically revise immunization activities and promotion and scientific literature, with the aim to appropriately address resources.

[Focus on health surveillance of health workers exposed to blood-transmissible biological agents: results and perspectives of a multicenter working group]. / Focus sulla sorveglianza sanitaria dei lavoratori della sanità esposti ad agenti biologici trasmissibili per via ematogena: risultati e prospettive di un gruppo di lavoro multicentrico.

The biological risk from exposure to bloodborne pathogens in health care environments represents a frequent and widespread risk, involving a large number of exposed workers. On the basis of the available scientific innovations, the recent legislation regarding health and safety of workers and the experiences of SIMLII guidelines on health surveillance (HS) workers exposed to biological risk, a multicenter study was carried out, involving nine relevant hospitals and about 32 000 healthcare workers (HCW). A review of the literature was performed, with particular reference to the last 10 years. For each hospital, protocols of HS have been examined according to tasks and biological risk from bloodborne viruses (HBV, HDV, HCV, HIV) as well as management of HCW infected with this pathogens. Differences of risk management in the hospitals, in relationship also with recommendations of the literature have been evaluated. The literature supplies important indications for HS management of HCW exposed to bloodborne pathogens, with relevant information also for patient safety. Preventive examinations are in line with the recommendations of literature and similar across the hospitals for HCV and HIV, while they are different for HBV. Periodic surveillance was different for the frequency, among the hospitals and also as compared to national SIMLII guidelines. As for management, no differentiation among the hospitals was detected as referred to different risk of exposure, while differences were observed around definitions of restrictions. Finally, good medical practices to support occupational physicians in the prevention and management of HCWs' exposed to biological risks are suggested.

Transforming growth factor beta signalling and matrix metalloproteinases in the mucosa overlying Crohn's disease strictures.

BACKGROUND AND AIMS: In addition to its crucial role in dampening tissue-damaging immune responses in the gut, transforming growth factor beta (TGFbeta) is a potent profibrogenic agent inducing collagen synthesis and regulating the balance between matrix-degrading matrix metalloproteinases (MMPs) and their inhibitors (TIMPs). TGFbeta signalling was investigated by analysis of Smad proteins and MMPs/TIMPs in the mucosa overlying strictures in patients with Crohn's disease (CD). METHODS: Specimens were collected from macroscopically normal mucosa overlying strictured and non-strictured gut of patients with fibrostenosing CD. Isolated myofibroblasts were cultured with anti-TGFbeta blocking antibody or TGF beta 1. TGFbeta transcripts were analysed by quantitative reverse transcription-PCR (RT-PCR). Smad proteins and MMPs were determined by immunoblotting. MMP-12 activity was measured by a real-time MMP-12 activity assay. An in vitro wound-healing scratch assay was used to assess myofibroblast migration. RESULTS: TGFbeta transcripts, phosphorylated Smad2-Smad3 (pSmad2-3) and TIMP-1 proteins were higher in mucosa overlying strictures than in mucosa overlying non-strictured areas. In contrast, mucosa overlying strictured gut had lower expression of Smad7, MMP-12 and MMP-3. Myofibroblasts from mucosa overlying strictured gut showed higher TGFbeta transcripts, a greater pSmad2-3 response to TGFbeta, increased TIMP-1, lower Smad7, increased collagen production and reduced migration ability compared with myofibroblasts from mucosa overlying non-strictured gut. TGFbeta blockade increased myofibroblast MMP-12 production and migration, more obviously in myofibroblasts isolated from mucosa overlying non-strictured compared with strictured gut. CONCLUSIONS: Changes in TGF-beta signalling and MMP production were identified in the mucosa overlying strictures in CD which may give a window into the process of fibrosis.

Crtap and p3h1 knock out zebrafish support defective collagen chaperoning as the cause of their osteogenesis imperfecta phenotype.

Prolyl 3-hydroxylation is a rare collagen type I post translational modification in fibrillar collagens. The primary 3Hyp substrate sites in type I collagen are targeted by an endoplasmic reticulum (ER) complex composed by cartilage associated protein (CRTAP), prolyl 3-hydroxylase 1 (P3H1) and prolyl cis/trans isomerase B, whose mutations cause recessive forms of osteogenesis imperfecta with impaired levels of α1(I)3Hyp986. The absence of collagen type I 3Hyp in wild type zebrafish provides the unique opportunity to clarify the role of the complex in vertebrate. Zebrafish knock outs for crtap and p3h1 were generated by CRISPR/Cas9. Mutant fish have the typical OI patients' reduced size, body disproportion and altered mineralization. Vertebral body fusions, deformities and fractures are accompanied to reduced size, thickness and bone volume. Intracellularly, collagen type I is overmodified, and partially retained causing enlarged ER cisternae. In the extracellular matrix the abnormal collagen type I assembles in disorganized fibers characterized by altered diameter. The data support the defective chaperone role of the 3-hydroxylation complex as the primary cause of the skeletal phenotype.

Sequential evaluation of thiopurine methyltransferase, inosine triphosphate pyrophosphatase, and HPRT1 genes polymorphisms to explain thiopurines' toxicity and efficacy.

AIM: To evaluate the polymorphisms of several genes involved in the azathioprine and mercaptopurine metabolism, in an attempt to explain their toxicity and efficacy in Crohn's disease and ulcerative colitis. METHODS: In 422 consecutive patients (250 with Crohn's disease and 172 with ulcerative colitis) and 245 healthy controls, single nucleotide polymorphisms of thiopurine methyltransferase, inosine triphosphate pyrophosphatase and hypoxanthine phosphoribosyl transferase (HPRT1) genes were related to the occurrence of adverse drug reactions (ADRs) and efficacy of therapy. RESULTS: Seventy-three patients reported 81 episodes of ADRs; 45 patients did not respond to therapy. Frequency of thiopurine methyltransferase risk haplotypes was significantly increased in patients with leucopenia (26% vs. 5.7% in patients without ADRs, and 4% of controls) (P < 0.001); no correlation with other ADRs and efficacy of therapy was found. Conversely, the frequency of inosine triphosphate pyrophosphatase and HPRT1 risk genotypes was not significantly different in patients with ADRs (included leucopenia). Non-responders had an increased frequency of inosine triphosphate pyrophosphatase risk genotypes (P = 0.03). CONCLUSIONS: The majority of azathioprine/mercaptopurine-induced ADRs and efficacy of therapy are not explained by the investigated gene polymorphisms. The combined evaluation of all three genes enhanced the correlation with leucopenia (43.5% vs. 23% in controls) (P = 0.008), at the expense of a reduced accuracy (60%).

[Management of "complicated" work fitness judgements among health care workers]. / La gestione delle "idoneità difficili" negli operatori della sanità.

The occupational physician, performing health surveillance within a hospital, may face to some difficulties due to the variety and complexity of the tasks and the health risk factors of the health care workers. One of the hardest issue for occupational physician is to provide judgement on worker's fitness. Moreover, this task could be more complicated when a impaired worker could represent an hazard for his patients and colleagues. The authors will illustrate three critical clinical cases examined in Occupational Health Unit of Luigi Sacco Hospital, Milan; furthermore, the authors will show the difficulties and the applied solutions in order to provide the judgement on worker's fitness.

[Implementation of a safety and health planning system in a teaching hospital]. / Implementazione di un sistema di gestione per la salute e la sicurezza (SGSS) in un'Azienda Ospedaliera Polo Universitario.

University Hospital "L. Sacco" had started in 2006 a two-year project in order to set up a "Health and Safety Management System (HSMS)" referring to the technical guideline OHSAS 18001:1999 and the UNI and INAIL "Guidelines for a health and safety management system at workplace". So far, the following operations had been implemented: Setting up of a specific Commission within the Risk Management Committee; Identification and appointment of Departmental Representatives of HSMS; Carrying out of a training course addressed to Workers Representatives for Safety and Departmental Representatives of HSMS; Development of an Integrated Informative System for Prevention and Safety; Auditors qualification; Inspection of the Occupational Health Unit and the Prevention and Safety Service: reporting of critical situations and monitoring solutions adopted. Short term objectives are: Self-evaluation through check-lists of each department; Sharing of the Improvement Plan among the departments of the hospital; Planning of Health and Safety training activities in the framework of the Hospital Training Plan; Safety audit.

[Influenza vaccination in health care workers of a university hospital in Milan]. / La vaccinazione antiinfluenzale nel personale sanitario dell'Ospedale L. Sacco di Milano.

The study analyses the percentage of influenza vaccination in health care workers of a big university hospital in Milan during the season 2006/2007. The percentage of vaccinated subjects was 19.8%. The frequency of vaccination has also been assessed according to sex, age, job and school title. Observed data indicates that the number of vaccinated sanitary workers is far below the levels reached in other European countries and in the USA. Thus, in order to reach a higher adhesion to vaccination programs, sensitisation campaigns are necessary.

Characterization of the functional and growth properties of long-term cell cultures established from a human somatostatinoma.

In somatostatinoma, a rare malignant somatostatin (SST)-secreting neoplasia, tumour regression is rarely observed, implying the need for novel antiproliferative strategies. Here, we characterized a long-term culture (SST-secreting cancer (SS-C cells)) established from a human somatostatinoma. High concentrations of SST and chromogranin A were released by SS-C cells and SST release was stimulated by depolarizing stimuli and inhibited by the SST analogue, octreotide. SS-C cells expressed mRNA for SST receptor (SSTR) subtypes 1, 2 and 4, being also able to bind native SST. Moreover, SS-C cells were positively stained with an antibody to SSTR2. SS-C cells also expressed interferon-gamma (IFN-gamma) receptor mRNA and measurable telomerase activity. Our findings indicate that in vitro exposure of SS-C cells to native SST-28, to octreotide, to IFN-gamma, or to 3'-azido-3'deoxythymidine (AZT), a telomerase inhibitor, results in inhibition of SS-C cell proliferation. Concomitant with growth inhibition, apoptosis was detected in SST-, octreotide-, IFN-gamma- or AZT-treated SS-C cell cultures. Taken together our results characterized native SST, SST analogues, IFN-gamma and a telomerase inhibitor as growth-inhibiting and proapoptotic stimuli in cultured human somatostatinoma cells. Based on these findings, the potential of SST analogues, IFN-gamma and AZT, alone or in combination, should be further explored in the medical treatment of somatostatinoma.

[Clinical guidelines for the management of gastrointestinal stromal tumors]. / Raccomandazioni cliniche per la diagnosi, la terapia ed il follow-up dei tumori stromali gastrointestinali.

Treatment of gastrointestinal stromal tumors (GIST) has been revolutioned by the recently discovered molecular mechanism responsible for the oncogenesis of this disease. In addition, due to the rapid progress at molecular and clinical level observed in the last few years, there is a need to review the current state of the art in order to delineate appropriate guidelines for the optimal management of these tumors. A panel of experts from several specialities, including medical oncology, surgery, pathology, molecular biology and imaging, were invited to participate in a meeting to present and discuss a number of pre-selected questions, and to achieve a consensus according to the categories of the National Comprehensive Cancer Network (NCCN) and the Standard Options Recommandations (SOR) of the French Federation of Cancer Centers. Generally, consensus points were from categories 2A of the NCCN and B2 of the SOR. Conventional histologic examination with immunohistochemistry for CD117, CD34, SMA, S-100 and desmin is considered standard. Molecular analysis for the identification of KIT and PDGFRA mutation may be indicated in CD117-negative GIST. Complete tumor resection with negative margins is the optimal surgical treatment. Adjuvant imatinib should be considered an experimental approach. Neoadjuvant imatinib is also experimental, although its use may be justified in unresectable or marginally resectable GIST. Imatinib should be started in metastatic or recurrent disease, and should be continued until progressive disease or drug intolerance. In these cases, sunitinib can be used. The optimal criteria for the assessment and monitoring of GIST undergoing imatinib therapy are not well known, but they should include reduction in tumor size and disease stabilization, as well as reduction of tumor density on CT scan and metabolic activity on PET scan.

Unbalanced germ-line expression of hMLH1 and hMSH2 alleles in hereditary nonpolyposis colorectal cancer.

We analyzed the hMLH1 and hMSH2 genes in 30 unrelated hereditary nonpolyposis colorectal cancer (HNPCC) patients using mutational and immunohistochemical analyses combined whenever possible with primer extension assays, designed to estimate hMLH1 and hMSH2 transcript expression in peripheral blood lymphocytes. Single-strand conformational polymorphism screening and PCR-direct sequencing revealed seven hMLH1 and five hMSH2 sequence variants in 14 unrelated HNPCC patients, including three definite pathogenic mutations, four amino acid substitutions of uncertain pathogenic significance, and five polymorphisms. Immunohistochemistry indicated the lack of either hMLH1 or hMSH2 protein expression in tumors from 13 patients, and the absence of both hMLH1 and hMSH2 immunostaining was observed in the tumor from one additional case. The lack of hMLH1 or hMSH2 immunostaining was associated with the presence of microsatellite instability in the corresponding tumor and was also observed in tumors from patients negative for pathogenic mutations by mutational screening. There was a marked unbalance in the allelic expression of either hMLH1 or hMSH2 transcripts in three of eight unrelated HNPCC patients that could be analyzed, although a less marked unbalance was detected in two additional patients. Tumors from patients with germ-line unbalance in hMLH1 or hMSH2 transcript expression did not express the corresponding mismatch repair protein and displayed microsatellite instability. Our results indicate that constitutional alterations in hMLH1 and hMSH2 transcript expression may represent genetic markers for HNPCC carrier status also in cases in which mutational analysis did not detect a definite pathogenic variant. This suggests that transcript deregulation may represent a relevant mode of germ-line inactivation for mismatch repair genes.

Zebrafish Collagen Type I: Molecular and Biochemical Characterization of the Major Structural Protein in Bone and Skin.

Over the last years the zebrafish imposed itself as a powerful model to study skeletal diseases, but a limit to its use is the poor characterization of collagen type I, the most abundant protein in bone and skin. In tetrapods collagen type I is a trimer mainly composed of two α1 chains and one α2 chain, encoded by COL1A1 and COL1A2 genes, respectively. In contrast, in zebrafish three type I collagen genes exist, col1a1a, col1a1b and col1a2 coding for α1(I), α3(I) and α2(I) chains. During embryonic and larval development the three collagen type I genes showed a similar spatio-temporal expression pattern, indicating their co-regulation and interdependence at these stages. In both embryonic and adult tissues, the presence of the three α(I) chains was demonstrated, although in embryos α1(I) was present in two distinct glycosylated states, suggesting a developmental-specific collagen composition. Even though in adult bone, skin and scales equal amounts of α1(I), α3(I) and α2(I) chains are present, the presented data suggest a tissue-specific stoichiometry and/or post-translational modification status for collagen type I. In conclusion, this data will be useful to properly interpret results and insights gained from zebrafish models of skeletal diseases.

Functionalized nanomaterials: are they effective to perform gene delivery to difficult-to-transfect cells with no cytotoxicity?

Nanodiamonds (NDs), multiwalled carbon nanotubes (MWCNTs) and gold nanorods (NRs) can be functionalized to promote gene delivery to hard-to-transfect cells with higher transfection efficiency than cationic lipids, and inducing less cell death.

Allelic loss in parathyroid tumors from individuals homozygous for multiple endocrine neoplasia type 1.

Homozygosity for the multiple endocrine neoplasia type 1 (MEN1) gene mutation was described in two of three affected siblings of a kindred in which both parents and the third daughter were heterozygotes. Surprisingly, in the two homozygotes, the disease history did not differ from the one of the heterozygotes. In the attempt to unravel genetic differences in parathyroid tumorigenesis between homozygotes and heterozygotes, restriction fragment length polymorphism analysis and microsatellite PCR analysis for loss of heterozygosity (LOH) at the MEN1 gene region on chromosome 11q13 was performed in parathyroid tissues removed at surgery from the mother, her heterozygous sister, and the three siblings. Allelic losses were evidenced in the larger glands of each patient, with a similar pattern of chromosome 11q12-13 losses. The somatic mutation consisted of a large lose of genetic material from chromosome 11. No gross differences exist in the 11q12-13 LOH observed between homozygous and heterozygous carriers. Interestingly, one of the parathyroid tumors from one heterozygote exhibited region of skipped LOH at the 11q12-13 region. The region in the depth of the critical interval retained heterozygosity, whereas those flanking it shared LOH. These findings indicate that inactivation of both copies of the MEN1 gene are not sufficient for parathyroid tumor development in MEN 1 patients and that tumor suppressor genes, other than the MEN1 gene on chromosome 11 or on other chromosomes, can be involved in the pathogenesis of parathyroid tumorigenesis in MEN 1 syndrome.

Guidelines for diagnosis and therapy of MEN type 1 and type 2.

This is a consensus statement from an international group, mostly of clinical endocrinologists. MEN1 and MEN2 are hereditary cancer syndromes. The commonest tumors secrete PTH or gastrin in MEN1, and calcitonin or catecholamines in MEN2. Management strategies improved after the discoveries of their genes. MEN1 has no clear syndromic variants. Tumor monitoring in MEN1 carriers includes biochemical tests yearly and imaging tests less often. Neck surgery includes subtotal or total parathyroidectomy, parathyroid cryopreservation, and thymectomy. Proton pump inhibitors or somatostatin analogs are the main management for oversecretion of entero-pancreatic hormones, except insulin. The roles for surgery of most entero-pancreatic tumors present several controversies: exclusion of most operations on gastrinomas and indications for surgery on other tumors. Each MEN1 family probably has an inactivating MEN1 germline mutation. Testing for a germline MEN1 mutation gives useful information, but rarely mandates an intervention. The most distinctive MEN2 variants are MEN2A, MEN2B, and familial medullary thyroid cancer (MTC). They vary in aggressiveness of MTC and spectrum of disturbed organs. Mortality in MEN2 is greater from MTC than from pheochromocytoma. Thyroidectomy, during childhood if possible, is the goal in all MEN2 carriers to prevent or cure MTC. Each MEN2 index case probably has an activating germline RET mutation. RET testing has replaced calcitonin testing to diagnose the MEN2 carrier state. The specific RET codon mutation correlates with the MEN2 syndromic variant, the age of onset of MTC, and the aggressiveness of MTC; consequently, that mutation should guide major management decisions, such as whether and when to perform thyroidectomy.

Glucose transport during ageing by human intestinal brush-border membrane vesicles.

Glucose absorption by the small intestine is a complex phenomenon, that can be successfully studied by means of isolated brush-border and basolateral membrane vesicles of the enterocytes. We have carried out transport experiments on isolated brush-border membrane vesicles from the human small intestine, taking into account the age of the subjects. Our studies demonstrated that Na+-glucose cotransporter activity decreased as age increased with the "overshoot" phenomenon disappearing altogether in the oldest subjects. This effect was compared to that observed in intestinal membrane vesicles of young patients suffering from Crohn's disease; in this case there was a marked decrease in the Na+-dependent D-glucose uptake, but the "overshoot", even though low, was present. K+-dependent D-glucose transport, diffusion of L-glucose and the levels of some enzyme markers for intestinal brush-border membranes were also studied.