Early melanoma invasivity correlates with gut fungal and bacterial profiles.

BACKGROUND: The microbiome is emerging as a crucial player of the immune checkpoint in cancer. Melanoma is a highly immunogenic tumour, and the composition of the gut microbiome has been correlated to prognosis and evolution of advanced melanoma and proposed as a biomarker for immune checkpoint therapy. OBJECTIVES: We investigated the gut fungal and bacterial compositions in early-stage melanoma and correlated microbial profiles with histopathological features. METHODS: Sequencing of bacterial 16S rRNA and the fungal internal transcribed spacer region was performed on faecal samples of patients with stage I and II melanoma, and healthy controls. A meta-analysis with gut microbiota data from patients with metastatic melanoma was also carried out. RESULTS: We found a combination of gut fungal and bacterial profiles significantly discriminating patients with melanoma from controls. In patients with melanoma, we observed an abundance of Prevotella copri and yeasts belonging to the order Saccharomycetales. We found that the bacterial and fungal community correlated to melanoma invasiveness, whereas the specific fungal profile correlated to melanoma regression. Bacteroides was identified as general marker of immunogenicity, being shared by regressive and invasive melanoma. In addition, the bacterial communities in patients with stage I and II melanoma were different in structure and richer than those from patients with metastatic melanoma. CONCLUSIONS: The composition of the gut microbiota in early-stage melanoma changes along the gradient from in situ to invasive (and metastatic) melanoma. Changes in the microbiota and mycobiota are correlated to the histological features of early-stage melanoma, and to the clinical course and response to immune therapies of advanced-stage melanoma, through direct or indirect immunomodulation.

Anti-inflammatory effect of a novel locally acting A2A receptor agonist in a rat model of oxazolone-induced colitis.

Adenosine represents a powerful modulating factor, which has been shown to orchestrate the scope, duration, and remission of the inflammatory response through the activation of four specific receptors, classified as A1, A2A, A2B, and A3, all being widely expressed in a variety of immune cells. Several selective A2A receptor agonists have displayed anti-inflammatory effects, through the suppression of IL-12, TNF, and IFN-γ production by monocytes and lymphocytes, in the setting of chronic intestinal inflammation. However, the therapeutic application of A2A receptor agonists remains hindered by the risk of serious cardiovascular adverse effects arising from the wide systemic distribution of A2A receptors. The present study focused on evaluating the anti-inflammatory effects of the novel poorly absorbed A2A receptor agonist PSB-0777 in a rat model of oxazolone-induced colitis as well as to evaluate its cardiovascular adverse effects, paying particular attention to the onset of hypotension, one of the main adverse effects associated with the systemic pharmacological activation of A2A receptors. Colitis was associated with decreased body weight, an enhanced microscopic damage score and increased levels of colonic myeloperoxidase (MPO). PSB-0777, but not dexamethasone, improved body weight. PSB-0777 and dexamethasone ameliorated microscopic indexes of inflammation and reduced MPO levels. The beneficial effects of PSB-0777 on inflammatory parameters were prevented by the pharmacological blockade of A2A receptors. No adverse cardiovascular events were observed upon PSB-0777 administration. The novel A2A receptor agonist PSB-0777 could represent the base for the development of innovative pharmacological entities able to act in an event-specific and site-specific manner.

High prevalence of circulating autoantibodies against thyroid hormones in vitiligo and correlation with clinical and historical parameters of patients.

BACKGROUND: Autoantibodies against thyroid hormones (THAbs) directed towards triiodothyronine (T3-Ab) and/or thyroxine (T4-Ab) are very rare in the general population. They are increased in some nonthyroidal autoimmune diseases, where they seem to predict autoimmune thyroid disorders (ATDs). So far, their presence in patients with vitiligo has not been evaluated, but it might have a possible predictive role. OBJECTIVES: To assess the prevalence of THAbs in a group of vitiligo patients and to correlate their presence with clinical and historical parameters. METHODS: In total 79 patients with nonsegmental vitiligo and 100 controls were examined. Clinical characteristics of vitiligo and family and personal medical history were evaluated. Antinuclear autoantibodies, thyroid hormones and thyroid autoantibodies were measured. IgM T3-Ab, IgG T3-Ab, IgM T4-Ab and IgG T4-Ab were assayed by a radioimmunoprecipitation technique. Fisher's test, Student's t-test and χ(2)-test were used for statistical analysis. RESULTS: Overall 77 of 79 patients (97%) had at least one type of THAb (11 T3-Ab, 10 T4-Ab, 56 both). In the control group, only one person (1%) had THAbs. In patients with vitiligo, T3-Abs were significantly associated with leucotrichia (IgM+IgG, P = 0.033; IgG, P = 0.039; IgM, P = 0.005) and thyroglobulin autoantibodies (IgM+IgG, P = 0.031; IgG, P = 0.058), while the absence of T3-Ab was related to personal history of cancer (IgM+IgG, P = 0.021; IgG, P = 0.039). T4-Abs were significantly associated with vitiligo activity (IgM+IgG, P < 0.001; IgM, P = 0.037) and duration (IgG, P = 0.013). CONCLUSIONS: The surprisingly high prevalence of THAb in patients with vitiligo and their associations suggest a possible pathogenetic role in the disease and stress the tight link between vitiligo and ATDs. Further evaluation in a larger group of patients and an adequate follow-up are needed to define their potential predictive role.

Non-segmental vitiligo and psoriasis comorbidity - a case-control study in Italian patients.

BACKGROUND: A recent systematic evaluation of vitiligo and psoriasis comorbidity has not yet been reported in a large series of patients with vitiligo. OBJECTIVE: To investigate the practical/clinical implications in subjects with both vitiligo and psoriasis compared to those with vitiligo alone. METHODS: This was a case-control study on 463 vitiligo patients in our clinic from March 2008 to April 2011. Medical assessment was performed by dermatologists using the modified Vitiligo European Task Force form. RESULTS: In an univariate analysis, inflammation/pruritus [odds ratio (OR) 2.42, P = 0.03], use of drugs that can induce psoriasis (OR 2.74, P = 0.01), a family history (FH) of psoriasis (OR 2.87, P = 0.02), cardiovascular disease (OR 5.70, P = 0.001), hypertension (OR 4.7, P = 0.006) and type 2 diabetes mellitus (OR 3.87, P = 0.004), were significantly correlated with patients exhibiting vitiligo and psoriasis comorbidity. A trend was found in personal history of cardiovascular disease in patients with both diseases (OR 2.99, P = 0.07). FH of vitiligo was significantly associated with patients having only vitiligo (OR 0.35, P = 0.05). Multivariate analysis demonstrated that inflammation/pruritus in vitiligo macules (OR 2.56, P = 0.047) and a FH of cardiovascular disease (OR 4.07, P = 0.02) were the most significant predictors of patients having both psoriasis and vitiligo, while the presence of organ-specific autoantibodies (OR 0.24, P = 0.007) was significantly associated with patients having only vitiligo. CONCLUSION: The presence of vitiligo and even mild psoriasis is significantly correlated with a family history of cardiovascular disease, a factor that requires greater attention and follow-up with respect to that necessary for vitiligo patients.

Autoimmune signals in non-segmental vitiligo patients are associated with distinct clinical parameters and toxic exposures.

BACKGROUND: Although non-segmental vitiligo is commonly considered an autoimmune disease, the possible differences between non-segmental vitiligo patients with and without autoimmune signals have not been clearly established. OBJECTIVE: To perform a comparison of non-segmental vitiligo patients with autoimmune signals (AIS) vs. those without autoimmune signals (NAIS) in regards to clinical characteristics and toxic/drug exposure. METHODS: 112 vitiligo patients were selected for a sex and age matched (1 : 1) case control study at an university based dermatology outpatient hospital specialized in pigmentary disorders. Medical assessment was performed by dermatologists using the modified Vitiligo European Task Force form and serological and clinical signs of autoimmunity were evaluated. RESULTS: Disease duration, age of onset, patient history of cardiovascular disease, past smoking history, use of drugs, and consummation of goitrogenic foods were all significantly increased in the AIS group using McNemar's test for matched pairs. In our conditional regression model, the simultaneous presence of disease duration, use of prescription drugs, and consummation of goitrogenic foods were the best predictors of AIS vitiligo patients. CONCLUSION: The evaluation of non-segmental vitiligo patients according to the presence vs. the absence of autoimmune signals allows us to correlate patients exhibiting autoimmune phenomenon with certain clinical characteristics, namely long disease duration, use of prescription drugs, and consumption of goitrogenic substances. In the presence of the aforementioned clinical profile, we suggest an evaluation of autoimmune signals.

Autoimmune markers in vitiligo patients appear correlated with obsession and phobia.

BACKGROUND: Current studies have treated a limited portion of the subjective aspects of vitiligo patients and have yet to elucidate possible psychological differences between those with autoimmune markers (AIM) with respect to those without autoimmune markers (NAIM). OBJECTIVE: To perform an age and gender-matched 1:1 case-control study through a comparison of non-segmental vitiligo patients with autoimmune features vs. those without autoimmune features in regards to psychiatric features, psychosomatic aspects and social parameters. METHODS: A total of 112 non-segmental vitiligo patients have been examined at the Florence University dermatology outpatient service (2nd dermatology unit). Vitiligo with an autoimmune background was defined by the presence of autoimmune antibodies and/or autoimmune diseases. Psychiatric screening was performed by dermatologists using the modified Middlesex Healthcare Questionnaire (MHQ); psychosomatic aspects and social impact were analysed with a standardized, Florentine questionnaire. RESULTS: Upon performing a conditional regression model, age, phobia and obsession were significantly predictive of the presence of AIM and a low total MHQ score was significantly predictive of NAIM in vitiligo patients. With univariate analysis, we found significant differences in: identifiable stress related to the onset of vitiligo, vitiligo triggered by stress, and modified interpersonal relationships related to vitiligo, which were associated with the subgroup containing autoimmunity markers. CONCLUSIONS: We found a higher prevalence of age, obsession and phobia among vitiligo patients AIM as compared to vitiligo patients NAIM. Thus, in the presence of demonstrated autoimmunity, screening for particular psychiatric aspects may be useful in the clinical practice of vitiligo.

Real-life efficacy and safety of Ustekinumab as second- or third-line therapy in Crohn's disease: results from a large Italian cohort study.

OBJECTIVE: Ustekinumab (UST) is an anti-IL12/23 antibody for the treatment of Crohn's Disease (CD). The aim of this study was to compare the efficacy and safety of UST in a large population-based cohort of CD patients who failed previous treatment with other biologics. PATIENTS AND METHODS: 194 CD patients (108 males and 86 females, mean age 48 years (range 38-58 years) were retrospectively reviewed. 147 patients were already treated with anti-TNFα (75.8%), and 47 (24.2%) patients were already treated with anti-TNFα and vedolizumab. Concomitant treatment with steroids was present in 177 (91.2%) patients. RESULTS: At week 12, clinical remission was achieved in 146 (75.2%) patients. After a mean follow-up of 6 months, clinical remission was maintained in 135 (69.6%) patients; at that time, mucosal healing was assessed in 62 (31.9%) patients, and it was achieved in 33 (53.2) patients. Three (1.5%) patients were submitted to surgery. Steroid-free remission was achieved in 115 (59.3%) patients. Both serum C-Reactive Protein and Fecal Calprotectin (FC) levels were significantly reduced with respect to baseline levels during follow-up. A logistic regression, UST therapy as third-line therapy (after both anti-TNFα and vedolizumab), FC >200 µg/g, and HBI ≥8 were significantly associated with lack of remission. Adverse events occurred in 5 (2.6%) patients, and four of them required suspension of treatment. CONCLUSIONS: UST seemed to be really effective and safe in CD patients unresponsive to other biologic treatments, especially when used as second-line treatment.

Common variable immunodeficiency in vitiligo.

Three cases of adult, non-segmental vitiligo patients in which primary, common variable immunodeficiency (CVID) was present are described. In two of the three cases, psoriasis was also present. Onset of CVID was diagnosed before vitiligo in two patients, and subsequent to the onset of vitiligo in the remaining patient. A family history of CVID was negative in all three cases. In contrast, a family history of vitiligo was present in two cases and a family history of psoriasis was present in one case. In regards to vitiligo, disease onset was gradual, with active disease in two cases, while the third case had an abrupt disease onset with borderline activity during clinical presentation. Cutaneous disease extension ranged from 2% to 12.3% in the three cases. Upon physical exam, Koebner phenomenon and signs of inflammation, such as pruritus were present in two patients; one of whom had scalp leukotrikia as well. Stress was a triggering factor in the development of vitiligo in two cases. The presence of CVID due to drugs or diseases known to cause secondary antibody deficiency were excluded in all three patients. Lastly, all patients were under treatment with immunoglobulin replacement therapy, which did not change the outcourse of vitiligo.

Genetic polymorphisms of thiopurine S-methyltransferase in a cohort of patients with systemic autoimmune diseases.

OBJECTIVES: Azathioprine (AZA) is a purine antimetabolite, prodrug widely used as a disease modifying drug in several rheumatic conditions. The aim of the present study was to evaluate the prevalence of TPMT genetic polymorphisms in a cohort of Italian Caucasian patients affected by rheumatic diseases and treated with AZA, and to establish correlations with the tolerability of AZA treatment. RESULTS: Seventy-eight Caucasian patients, 16 males and 62 females, median age 41 years (min-max: 24-76) were enrolled. At the time of evaluation, the median duration of treatment with AZA was 8 months (min-max: 2-150 months); the median dose of AZA per kg of body weight was 1.42 mg (min-max: 0.5-2). Among the 78 patients evaluated, 76 presented a wild type genotype (TPMT *1), while polymorphic alleles were identified in 2 patients (2.6%). Twenty-five patients (32%) experienced different types of adverse events (AE) under AZA treatment. Eighteen patients (23.1%) discontinued AZA because of AE. No correlation was observed between polymorphic TPMT alleles and the development of AE. CONCLUSIONS: Our analysis supports the view that TPMT genotyping alone is not sufficient to adequately personalize the AZA dosage in rheumatic patients. Further studies based on phenotypic analysis of TPMT enzyme and assay of AZA metabolite appear to be required.

Somatostatin inhibits colon cancer cell growth through cyclooxygenase-2 downregulation.

BACKGROUND AND PURPOSE: Cyclooxygenase-2 (COX-2) is expressed in colonic neoplasms, where it supports cell proliferation via prostaglandin E(2) (PGE(2)) production. This study investigated the effects of somatostatin-14 on COX-2 expression, PGE(2) production and proliferation in colon cancer cells. EXPERIMENTAL APPROACH: Human colon adenocarcinoma cell lines Caco-2, HT-29 and HCT116 were used. The following techniques were employed: colourimetric assay for cell growth; 5-bromo-2'-deoxyuridine assay for DNA synthesis; enzyme immunoassay for PGE(2); COX-2 mRNA silencing; RT-PCR or Western blot for somatostatin receptor subtypes, cyclooxygenase isoforms, phosphorylated-ERK-1/ERK-2 and phosphorylated-Akt. KEY RESULTS: HT-29 and Caco-2 cells expressed COX-2 and somatostatin receptors (sst(3/4/5) and sst(3/5), respectively). HCT116 cells did express somatostatin receptors (sst(2/3/5)), but not COX-2. Somatostatin-14 inhibited basal COX-2 expression, PGE(2) production, DNA synthesis and growth in Caco-2 cells and these effects were prevented by BN81658 (sst(3) receptor antagonist). Basal proliferation of HT-29, HCT116 and COX-2-silenced Caco-2 cells was not affected by somatostatin-14. Stimulation of HT-29 cells with gastrin-17 elicited increments of ERK-1/ERK-2 and Akt phosphorylation, COX-2 expression, PGE(2) production, DNA synthesis and cell growth, which were all counteracted by somatostatin-14. Somatostatin-14-induced inhibition of COX-2 expression, PGE(2) production and DNA synthesis were blocked by BIM23056 (sst(5) receptor antagonist). CONCLUSIONS AND IMPLICATIONS: Somatostatin decreases COX-2 expression and function in colon cancer cells via activation of sst(3) or sst(5) receptors, and these effects contribute to the inhibitory action of somatostatin on cell proliferation. These findings can be relevant to the development of therapeutic strategies based on the modulation of the COX-2 pathway.

Effects of a bicarbonate-alkaline mineral water on digestive motility in experimental models of functional and inflammatory gastrointestinal disorders.

This study investigates the effects of Uliveto, a bicarbonate-alkaline mineral water, in experimental models of diarrhea, constipation and colitis. Rats were allowed to drink Uliveto or oligomineral water (control) for 30 days. Diarrhea and constipation were evoked by 16,16-dimethyl-prostaglandin E(2) (dmPGE(2)) or loperamide, respectively. Colitis was induced by 2,4-dinitrobenzenesulfonic acid (DNBS) or acetic acid. Gastric emptying, small-intestinal and colonic transit were evaluated. dmPGE(2)-induced diarrhea reduced gastric emptying and increased small-intestinal and colonic transit. In this setting, Uliveto water enhanced gastric emptying, and this effect was prevented by L-365,260 (gastrin receptor antagonist). Loperamide-induced constipation reduced gastric emptying, small-intestinal and colonic transit, and these effects were prevented by Uliveto water. L-365,260 counteracted the effects of Uliveto on gastric emptying, while alosetron (serotonin 5-HT(3) receptor antagonist) blunted the effect of Uliveto on colonic transit. Gastric emptying, small-intestinal and colonic transit were reduced in DNBS-induced colitis, and Uliveto water enhanced gastric emptying and normalized small-intestinal and colonic transit. Gastric emptying, small-intestinal and colonic transit were also reduced in acetic acid-induced colitis, and Uliveto increased both gastric emptying and small-intestinal transit. In conclusion, Uliveto water exerts beneficial effects on gastrointestinal motility in the presence of bowel motor dysfunctions. The effects of Uliveto water on gastric emptying depend on gastrin-mediated mechanisms, whereas the activation of serotonergic pathways accounts for the modulation of colonic functions.

Cholecystokinin CCK2 receptors mediate the peptide's inhibitory actions on the contractile activity of human distal colon via the nitric oxide pathway.

BACKGROUND AND PURPOSE: Cholecystokinin is known to exert stimulant actions on intestinal motility via activation of type 1 cholecystokinin receptors (CCK(1)). However, the role played by cholecystokinin 2 (CCK(2)) receptors in the regulation of gut motility remains undetermined. This study was designed to examine the influence of CCK(2) receptors on the contractile activity of human distal colon. EXPERIMENTAL APPROACH: The effects of compounds acting on CCK(2) receptors were assessed in vitro on motor activity of longitudinal smooth muscle, under basal conditions as well as in the presence of KCl-induced contractions or transmural electrical stimulation. KEY RESULTS: Cholecystokinin octapeptide sulphate induced concentration-dependent contractions which were enhanced by GV150013 (CCK(2) receptor antagonist; +57% at 0.01 microM). These effects were unaffected by tetrodotoxin. The enhancing actions of GV150013 on contractions evoked by cholecystokinin octapeptide sulphate were unaffected by N(omega)-propyl-L-arginine (NPA, neuronal nitric oxide synthase inhibitor), while they were prevented by N(omega)-nitro-L-arginine methylester (L-NAME, non-selective nitric oxide synthase inhibitor). In the presence of KCl-induced contractions, cholecystokinin octapeptide sulphate elicited concentration-dependent relaxations (-36%), which were unaffected by NPA, but were counteracted by GV150013 or L-NAME. The application of electrical stimuli evoked phasic contractions which were enhanced by GV150013 (+41 % at 0.01 microM). CONCLUSIONS AND IMPLICATIONS: CCK(2) receptors mediate inhibitory actions of cholecystokinin on motor activity of human distal colon. It is suggested that CCK(2) receptors exert their modulating actions through a nitric oxide pathway, independent of the activity of the neuronal nitric oxide synthase isoform.

Effects of L-DOPA/benserazide co-treatment on colonic excitatory cholinergic motility and enteric inflammation following dopaminergic nigrostriatal neurodegeneration.

INTRODUCTION: The mainstay therapy for Parkinson's disease (PD) relies on L-3,4-dihydroxyphenylalanine (L-DOPA) plus a DOPA-decarboxylase inhibitor. However, their effects on colonic dysmotility and inflammation observed in PD are undetermined. This study examined the effects of L-DOPA plus benserazide (BE) on colonic motility and inflammation in rats with central nigrostriatal dopaminergic denervation. METHODS: Neurodegeneration was induced by 6-hydroxydopamine (6-OHDA) injection into the medial forebrain bundle (MFB). 6-OHDA animals were treated orally with L-DOPA/BE for 28 days, starting 28 days after 6-OHDA injection. At the end of treatment, in vivo colonic transit was evaluated by a radiologic assay. Electrically stimulated (ES) cholinergic contractions were recorded in vitro from colonic preparations, while acetylcholine release was measured in the incubation medium. Choline acetyltransferase (ChAT) and glial fibrillary acidic protein (GFAP) expression as well as eosinophil and mast cell density were examined in the colonic wall by immunohistochemistry. Colonic TNF and IL-1ß levels were also assayed. RESULTS: 6-OHDA animals displayed: 1) decrease in in vivo colonic transit; 2) impairment of ES-stimulated cholinergic contractions; 3) decreased acetylcholine release from myenteric nerves; 4) decrease in ChAT and increase in GFAP myenteric immunopositivity; 5) increase in eosinophil and mast cell density; 6) increase in TNF and IL-1ß levels. Treatment with L-DOPA/BE elicited an improvement of in vivo and in vitro colonic motor activity, a normalization of acetylcholine release, ChAT immunopositivity, as well as pro-inflammatory cytokine patterns, ganglionic GFAP levels, eosinophil and mast cell density. CONCLUSION: Under dopaminergic nigrostriatal denervation, treatment with L-DOPA/BE ameliorated colonic motility through a normalization of myenteric cholinergic neurotransmission, along with an improvement of colonic inflammation.

Constitutive expression of cyclooxygenase-2 in the neuromuscular compartment of normal human colon.

Prostaglandins regulate various functions throughout the gastrointestinal system. Their biosynthesis depends on cyclooxygenase isoforms, named COX-1 and COX-2. The initial hypothesis that COX-2 is an inducible enzyme has been challenged and its constitutive expression in the stomach has been established. In this study, an immunohistochemical analysis was performed to evaluate the distribution and cellular localization of COX-2 in normal human colon. Colonic surgical specimens were processed for COX-2, protein HuC/HuD, neurofilament, S-100 protein and CD117/c-kit immunodetection. COX-2 protein was found to be constitutively expressed in the colonic wall: detectable amounts were localized in mucosal, submucosal and muscular layers, mainly in the neuromuscular compartment. In particular, COX-2 was expressed in muscularis mucosae, submucosal ganglia, longitudinal muscle layer and myenteric ganglia, the neurons of which displayed different degrees of immunostaining. Intramuscular interstitial cells of Cajal, regarded as important sites for the regulation of enteric neuromuscular activity, were also partly COX-2 immunoreactive. This study provides a detailed mapping of COX-2 expression in human colon, and allows better understanding of the roles played by this isoenzyme in gut physiology.

Adult Onset Vitiligo: Multivariate Analysis Suggests the Need for a Thyroid Screening.

Background. There are limited epidemiological studies evaluating the effect of age at onset on disease features in vitiligo. Objectives. To identify factors associated with adult onset vitiligo in comparison with childhood onset vitiligo. Patients and Methods. We retrospectively collected medical records of 191 patients. Such records included clinical examination, personal and familial medical history, laboratory evaluations, concomitant vitiligo treatment and drug assumption. Results. 123 patients with a disease onset after the age of 40 (adult onset vitiligo) were compared with 68 patients who developed vitiligo before the age of 12 (childhood onset vitiligo). Multivariate analysis revealed that personal history of thyroid diseases (P = 0.04; OR 0.4), stress at onset (P = 0.002; OR = 0.34), personal history of autoimmune thyroid disease (ATD) (P = 0.003; OR = 0.23), and thyroid nodules (P = 0.001; OR 0.90) were independently associated with adult onset vitiligo, whereas family history of dermatological diseases (P = 0.003; OR = 2.87) and Koebner phenomenon (P < 0.001; OR = 4.73) with childhood onset vitiligo. Moreover, in the adult onset group, concomitant thyroid disease preceded vitiligo in a statistically significant number of patients (P = 0.014). Conclusions. Childhood onset and adult onset vitiligo have different clinical features. In particular, ATD and thyroid nodules were significantly associated with adult onset vitiligo, suggesting that a thyroid screening should be recommended in this group of patients.

Intestinal dysfunction in Parkinson's disease: Lessons learned from translational studies and experimental models.

BACKGROUND: Symptoms of digestive dysfunction in patients with Parkinson's disease (PD) occur at all stages of the disease, often preceding the onset of central motor symptoms. On the basis of these PD-preceding symptoms it has been proposed that PD could initiate in the gut, and that the presence of alpha-synuclein aggregates, or Lewy bodies in the enteric nervous system might represent one of the earliest signs of the disease. Following this hypothesis, much research has been focused on the digestive tract to unravel the mechanisms underlying the onset and progression of PD, with particular attention to the role of alterations in enteric neurotransmission in the pathophysiology of intestinal motility disturbances. There is also evidence suggesting that the development of central nigrostriatal neurodegeneration is associated with the occurrence of gut inflammation, characterized by increments of tissue pro-inflammatory markers and oxidative stress, which might support conditions of bowel neuromotor abnormalities. PURPOSE: The present review intends to provide an integrated and critical appraisal of the available knowledge on the alterations of enteric neuromuscular pathways regulating gut motor activity both in humans and preclinical models of PD. Moreover, we will discuss the possible involvement of neuro-immune mechanisms in the pathophysiology of aberrant gastrointestinal gut transit and neuromuscular activity in the small and large bowel.

Mechanisms of protection by pantoprazole against NSAID-induced gastric mucosal damage.

The use of nonsteroidal anti-inflammatory drugs (NSAIDs) can be associated with severe adverse digestive effects. In clinical settings, proton pump inhibitors have proven to be effective in preventing and healing NSAID-induced gastroduodenal lesions. The present study investigates the mechanisms of protection afforded by pantoprazole against gastric injury induced by different NSAIDs in rats. Animals were orally treated with indomethacin (100 micromol/kg), diclofenac (60 micromol/kg), piroxicam (150 micromol/kg) or ketoprofen (150 micromol/kg). Thirty minutes before NSAIDs, animals received pantoprazole 6 or 60 micromol/kg orally. Four hours after NSAIDs, the following parameters were assessed: histomorphometric evaluation of gastric mucosal damage; gastric mucosal levels of myeloperoxidase (MPO), malondialdehyde (MDA), reduced glutathione as an index of non-proteic sulfhydryl compounds (GSH), and prostaglandin E2 (PGE2); mucosal cyclooxygenase-1 and -2 (COX-1, COX-2) mRNA expression by reverse transcription-polymerase chain reaction (RT-PCR). Separate experiments were carried out to assay the effects of pantoprazole on gastric acid secretion in pylorus-ligated rats. The in vitro influence of pantoprazole (1-10 microM) on the oxidation of low density lipoproteins (LDLs) induced by copper sulphate was also examined. All NSAIDs elicited mucosal necrotic lesions associated with neutrophil infiltration and reduction of PGE2 levels. Increments of MPO and MDA contents, as well as a decrease in GSH levels, were detected in the gastric mucosa of indomethacin-, piroxicam- or ketoprofen-treated animals. Indomethacin enhanced mucosal COX-2 expression, while not affecting COX-1. At the oral dose of 6 micromol/kg pantoprazole did not affect NSAID-induced mucosal damage, whereas at 60 micromol/kg it markedly reduced injuries provoked by all test NSAIDs. Pantoprazole 60 micromol/kg also reversed the effects of NSAIDs on MPO, MDA, and GSH mucosal contents, without interfering with the decrease in PGE2 levels or indomethacin-induced COX-2 expression. However, at both doses, pantoprazole inhibited acid secretion in pylorus-ligated rats. Furthermore, pantoprazole concentration dependently reduced the in vitro oxidation of LDLs. Our results suggest that besides inhibiting acid secretion, the protection afforded by pantoprazole against NSAID-induced gastric damage depends on a reduction in mucosal oxidative injury, which may also account for an increment of sulfhydryl radical mucosal bioavailability. It is also suggested that pantoprazole does not influence the down-regulation of gastric prostaglandin production associated with NSAID treatment.

Disposition of digoxin immune Fab in patients with kidney failure.

Digoxin and digoxin immune Fab, its antidote, are eliminated renally. However, the disposition of Fab in severe kidney disease is poorly described. Therefore, the disposition of Fab and its relationship to total and free digoxin were studied in five digoxin-toxic patients with end-stage renal disease (n = 4) or severe renal dysfunction (n = 1) with a mean (+/- SD) serum creatinine of 5.9 +/- 1.2 mg/dl (four patients were receiving long-term hemodialysis). Serum was drawn after a clinically neutralizing Fab dose (80 to 160 mg) every 12 to 24 hours for 204 to 327 hours. Fab concentrations were assessed by radioimmunoassay, whereas total digoxin concentrations were assessed with a modified radioimmunoassay or fluorescence polarization immunoassay. The concentration-time profile of Fab appeared to be similar to the concentration-time profile of total digoxin. The mean (+/- SD) half-lives of the alpha and beta disposition phases of Fab were 13 +/- 5 hours and 96 +/- 31 hours, respectively, which were similar to the alpha and beta parameter estimates of total digoxin (14 +/- 4 and 123 +/- 16 hours, respectively). Steady-state volume of distribution and systemic clearance of Fab were 0.29 +/- 0.11 L/kg and 0.057 +/- 0.022 ml/min/kg, respectively. Thus, in comparison to values reported in patients with normal renal function, the elimination of Fab and total digoxin are markedly delayed in patients with end-stage renal disease, which may necessitate prolonged clinical monitoring.