Experimental colitis in IL-10-deficient mice ameliorates in the absence of PTPN22.

Interleukin (IL)-10 plays a key role in controlling intestinal inflammation. IL-10-deficient mice and patients with mutations in IL-10 or its receptor, IL-10R, show increased susceptibility to inflammatory bowel diseases (IBD). Protein tyrosine phosphatase, non-receptor type 22 (PTPN22) controls immune cell activation and the equilibrium between regulatory and effector T cells, playing an important role in controlling immune homoeostasis of the gut. Here, we examined the role of PTPN22 in intestinal inflammation of IL-10-deficient (IL-10-/- ) mice. We crossed IL-10-/- mice with PTPN22-/- mice to generate PTPN22-/- IL-10-/- double knock-out mice and induced colitis with dextran sodium sulphate (DSS). In line with previous reports, DSS-induced acute and chronic colitis was exacerbated in IL-10-/- mice compared to wild-type (WT) controls. However, PTPN22-/- IL-10-/- double knock-out mice developed milder disease compared to IL-10-/- mice. IL-17-promoting innate cytokines and T helper type 17 (Th17) cells were markedly increased in PTPN22-/- IL-10-/- mice, but did not provide a protctive function. CXCL1/KC was also increased in PTPN22-/- IL-10-/- mice, but therapeutic injection of CXCL1/KC in IL-10-/- mice did not ameliorate colitis. These results show that PTPN22 promotes intestinal inflammation in IL-10-deficient mice, suggesting that therapeutic targeting of PTPN22 might be beneficial in patients with IBD and mutations in IL-10 and IL-10R.

Juvenile dermatomyositis: A report of three cases.

Juvenile dermatomyositis (JDM), an autoimmune idiopathic myositis, is characterized by rash and proximal muscle weakness. Immunohistopathology typically shows perivascular inflammatory infiltrate with predominance of CD4+ T lymphocytes, perifascicular atrophy, and upregulation of major histocompatibility complex class I. JDM has been attributed to a humoral-driven muscle microangiopathy probably implicating the type I interferon pathway. Tubulo-reticular inclusions present in endothelial cell of muscle are biomarkers of interferon exposure, and so may be an indirect data of this myopathy especially in the absence of rash and inflammatory infiltrate. We report on three patients in which electron microscopy solves the differential diagnosis among infantile myositis showing peculiar inclusions.

Thymosin-alpha 1 (Zadaxin) enhances the immunogenicity of an adjuvated pandemic H1N1v influenza vaccine (Focetria) in hemodialyzed patients: a pilot study.

BACKGROUND: Although influenza vaccination is widely recommended for immunosuppressed people, the same immune dysfunction that can increase the risk of contracting influenza might also compromise vaccine effectiveness, especially during pandemics. Clinical data have highlighted the role of adjuvants in improving vaccine efficacy. As uremic patients are especially vulnerable to infections, it is recommended that they should be vaccinated yearly against influenza. This paper presents the results of a pilot clinical trial, conducted in hemodialyzed patients with an adjuvated pandemic H1N1v influenza vaccine alone and combined with Thymosin-alpha 1. METHODS: Subjects were subdivided into 3 treatment groups receiving: the adjuvated pandemic influenza vaccine (Focetria) only (first treatment group), and the Vaccine+Thymosin alpha 1 (Zadaxin) at a dose of 3.2 and 6.4 mg (second and third treatment groups respectively). The immunoresponse was assessed on days 0, 21, 42, 84 and 168 after vaccine administration by means of Hemagglutination Inhibition (HI), Microneutralization (MN) and Single Radial Hemolysis (SRH) assays. The CHMP regards HI as the gold standard test to evaluate the immune response to influenza vaccines before influenza vaccines are licensed. The CHMP criteria are slightly different in adults (18-60-year-old subjects) and the elderly (>60 years old). Indeed, 40% of seroconversion, 70% of subjects seroprotected 21 days after vaccination, and a 2.5-fold increase in GMR (Geometric Mean Ratio) are required in adults, while in the elderly, the corresponding threshold values are: 30%, 60% and a 2-fold increase. All these criteria must be met for the licensing of a pandemic influenza vaccine. Safety evaluation was performed by means of Adverse Event (AE) recording, laboratory assays (hematology and chemistry), electrocardiogram, and assessment of vital signs. RESULTS: Three populations were considered: Intention-To-Treat (ITT) (94 patients), Per Protocol (PP) (82 patients), and Safety population (99 patients). With regard to the Geometric Mean Titer (GMT) and the Geometric Mean Ratio (GMR) of HI on Day 21 in the ITT population, both "Vaccine+Thymosin alpha 1" groups presented better results than the "Vaccine only" group. A large proportion of ITT patients in the two Vaccine+Thymosin alpha 1 groups achieved seroconversion by Day 21. On Day 42, the decrease in the GMT of HI was greater in the Vaccine+Thymosin alpha 1 groups than in the vaccine only group. Similar results were obtained in the PP population. The CHMP criteria were fully met in the groups treated with Vaccine+Thymosin alpha 1. No AE was found to be related to Thymosin alpha 1 nor to the Focetria vaccine. CONCLUSIONS: Although further studies in larger hemodialyzed populations are necessary, it can be concluded that Thymosin alpha 1 enhanced the immunogenicity of the pandemic influenza vaccine used. Moreover, it proved safe and well tolerated, and did not affect hematology or blood-chemistry values.

Ultrastructural changes in dysferlinopathy support defective membrane repair mechanism.

BACKGROUND: The dysferlin gene has recently been shown to be involved in limb girdle muscular dystrophy type 2B and its allelic disease, Miyoshi myopathy, both of which are characterised by an active muscle degeneration and regeneration process. Dysferlin is known to play an essential role in skeletal muscle fibre repair, but the process underlying the pathogenetic mechanism of dysferlinopathy is not completely understood. AIMS: To define both specific alterations of muscle fibres and a possible sequential mechanism of myopathy development. METHODS: A histological, immunohistochemical, and ultrastructural analysis of 10 muscle biopsies from patients with molecularly diagnosed dysferlinopathy. RESULTS: An inflammatory response was seen in most of the muscle biopsies. The immunohistochemical pattern demonstrated active regeneration and inflammation. Non-necrotic fibres showed alterations at different submicroscopic levels, namely: the sarcolemma and basal lamina, subsarcolemmal region, and sarcoplasmic compartment. In the subsarcolemmal region there were prominent aggregations of small vesicles, probably derived from the Golgi apparatus, which consisted of empty, swollen cisternae. In the sarcolemma there were many gaps and microvilli-like projections, whereas the basal lamina was multilayered. CONCLUSIONS: The histopathological, immunohistochemical, and ultrastructural data show that dysferlinopathy is characterised by a very active inflammatory/degenerative process, possibly associated with an inefficient repair and regenerative system. The presence of many crowded vesicles just beneath the sarcolemma provides submicroscopical proof of a defective resealing mechanism, which fails to repair the sarcolemma.

Effects of alprostadil on blood rheology and nucleoside metabolism in patients affected with lower limb chronic ischaemia.

The acute (0.57 microg/kg i.v. in 2 hours) and long-term (0.57 microg/kg i.v. in 2 hours for 5 days over 4 weeks) effects of the PGE1 analogue alprostadil were studied in patients affected with intermittent claudication. Whole Blood Viscosity (WBV), Whole Blood Filterability (WBF), haematocrit (Htc) and fibrinogen plasma concentration, were studied together with P50, 2,3-diphosphoglycerate, and adenosine plasma levels. Moreover, in the long-term study, pain-free (PFWD) and maximal walking distance (MWD) were measured. Single alprostadil infusion induced an improvement in WBV, WBF, and oxygen transport, and an increase in adenosine plasma levels. Long-term alprostadil administration produced a decrease in WBV only, without significant changes in WBF, Htc, fibrinogen, P50, 2,3-diphosphoglycerate, also inducing a significant prolongation of PFWD and MWD. The possibility is suggested that pulse rises in adenosine plasma levels play a role in the effects of chronic alprostadil administration, maybe in a way similar to that observed in the phenomenon of ischaemic preconditioning,

Sneddon syndrome, arylsulfatase A pseudodeficiency and impairment of cerebral white matter.

We describe a 11 year-old-boy with Sneddon syndrome, confirmed by skin biopsy, and MR evidence of diffuse cerebral hyperintensity of white matter; he also suffered from pre-perinatal hypoxic-ischemic distress. Arylsulfatase A activity was found reduced because of arylsulfatase A pseudodeficiency. We suggest that the association of pre-perinatal distress, Sneddon syndrome and arylsulfatase A pseudodeficiency is responsible for the diffuse impairment of cerebral white matter, never reported in Sneddon syndrome and similar to described cases of delayed posthypoxic demyelination and arylsulfatase A pseudodeficiency.

The asialoglycoprotein receptor in human hepatocellular carcinomas: its expression on proliferating cells.

The expression of the asialoglycoprotein receptor (ASGP-R) on human hepatocellular carcinoma (HCC) cells might be exploited to reduce the extrahepatic toxicity of DNA synthesis inhibitors by their conjugation with galactosyl-terminating peptides. In the present study we first assessed the frequency of ASGP-R expression in 60 HCCs. Secondly, we investigated whether the receptor was maintained on the plasma membranes of DNA synthesizing cancer cells. Needle biopsies of HCC were evaluated. Diagnosis and grading of HCC were performed on routine haematoxylin and eosin-stained sections according to Edmondson and Steiner (1953). Thirty-five tumours were grade I and II and were classified as well differentiated, while 25 tumours were grade III and IV and were classified as poorly differentiated. Sections from formalin-fixed, paraffin-embedded samples were incubated, after antigen retrieval, with an anti-ASGP-R monoclonal antibody revealed by secondary biotinylated antibody and streptavidin-biotin-peroxidase-diaminobenzidine reaction. A clear immunolabelling of plasma membranes of HCC cells was observed in 28 out of 35 (80%) well differentiated (grade I and II) and in five out of 25 (20%) poorly differentiated (grade III and IV) HCCs. The presence of the ASGP-R on the surface of DNA synthesizing cancer cells was also investigated after in vitro bromodeoxyuridine (BrdU) labelling of HCC samples by immunohistochemical visualization of both the ASGP-R and incorporated BrdU on the same section. The results obtained clearly demonstrated that DNA synthesizing cancer cells expressed the ASGP-R on their surface. The presence of ASGP-R on cell plasma membrane in the majority of differentiated HCCs and its maintenance on proliferating cells encourages studies in order to restrict the action of the inhibitors of DNA synthesis of HCC cells by their conjugation with galactosyl-terminating carriers internalized through this receptor.

Kindler syndrome: report of a case with ultrastructural study and review of the literature.

Kindler syndrome is characterized by a generalized, progressive poikiloderma with cutaneous atrophy, congenital acral skin blistering, and photosensitivity. Since the first description, approximately 70 cases have been reported worldwide, but ultrastructural studies were performed in only five patients. In none of these patients were biopsies done at birth. In our patient ultrastructural studies were performed both of the blister at birth and of the poikilodermatous and atrophic skin at 6 years of age. Some ultrastructural features in the context of a bullous disease of the newborn that resembles epidermolysis bullosa, should alert investigators to the possibility of Kindler syndrome even in absence of the typical clinical signs.

Pharmacological preconditioning of ischemic heart disease by low-dose dipyridamole.

Fourteen patients affected with coronary artery disease underwent two consecutive dipyridamole echocardiographic stress tests, in basal conditions and after repeated low doses of intravenous dipyridamole, following the observation that pulse increases in adenosine plasma levels due to repeated intravenous administration of dipyridamole mimic the mechanism of ischemic preconditioning. Echocardiographic, electrocardiographic, haemodynamic parameters, and adenosine plasma levels were measured. After the second test, six patients were completely negative, and in those eight still positive the onset of dyssynergy was delayed.

Mid-dermal elastolysis: a pathological and ultrastructural study of five cases.

The aim of this study was to evaluate the presence of inflammatory phenomena and elastic fiber phagocytosis in mid-dermal elastolysis. The pathological and ultrastructural features of 5 Caucasian female patients (ranging from 26 to 40 years) with acquired diffuse asymptomatic areas of skin wrinkling have been reviewed. The clinical features of all cases were characteristic of this condition and only in one patient were erythematous urticaria-like, non pruriginous patches also observed. In 4 cases a history of prolonged sun bathing was present and in 3 cases there was a short history of oral contraception. The pathological study confirmed the typical absence of elastic fibers in the midreticular dermis. In two cases elastic fibers were still detectable in the periadnexal dermis. Hematoxylin and eosin sections showed a mild perivascular infiltrate in two cases, while in three patients histiocytes were scattered among collagen bundles. Multinucleated giant cells containing fragmented elastic fibers were detectable in one patient. Ultrastructural analysis revealed large mononuclear cells with phagocytic aspects toward elastic fibers in all cases.

Human epidermal Langerhans cells express the ICAM-3 molecule. Immunohistochemical and immunoelectron microscopical demonstration.

Three ligands have been described for the leucocyte integrin LFA-1, namely intercellular adhesion molecule (ICAM)-1, ICAM-2, and ICAM-3. ICAMs show differences in tissue distribution and inducibility. The recently described ICAM-3 is highly expressed on resting lymphocytes, monocytes and neutrophils. Here, we demonstrate that the whole human epidermal Langerhans cell (LC) population expresses this molecule. Immunohistochemical staining of skin sections with an anti-ICAM-3 monoclonal antibody displayed reactivity with dendritic epidermal cells regularly distributed along the epidermis. Highly-sensitive immunoelectron microscopy procedures, performed on freshly suspended epidermal cells both at transmission and scanning electron microscopic levels, enabled demonstration that the whole LC population expresses cell surface ICAM-3. In contrast, keratinocytes and melanocytes were consistently negative. The prominent expression of ICAM-3 by resident LC could imply a crucial part for this molecule in leucocyte-intercellular interactions in the skin.

Evidence of an adenosine-dependent mechanism in the hypotensive effect of L-arginine in man.

1. The hypothesis that endogenous adenosine could play a role in the haemodynamic response to L-arginine is investigated. 2. The study has been divided into two parts. The first part was a single blind, randomized, placebo-controlled study in which L-arginine i.v. infusion (0.07 mmol/kg per min) in five healthy volunteers caused a significant fall in systolic (-14.2%, from 129.0 +/- 8.2 to 110.6 +/- 8.5 mmHg; F = 62.89, P < 0.01), diastolic (-16%, from 80.0 +/- 7.9 to 67.2 +/- 7.0 mmHg; F = 18.97, P < 0.01) and mean (-15.5%, from 96.4 +/- 6.7 to 81.4 +/- 6.5 mmHg; F = 28.78, P < 0.01) arterial blood pressure, with a concomitant increase of plasma adenosine concentration (from 244.0 +/- 32.2 to 637.0 +/- 43.4 nmol/L; F = 79.3 P < 0.01). Maximal effects were obtained at the end of L-arginine infusion: haemodynamic parameters returned to basal values in about 30 min while adenosine concentrations normalized in about 15 min. Saline infusion had no effect on these parameters. 3. In the second study the effect of L-arginine i.v. infusion on arterial blood pressure, lower limb blood flow and plasma adenosine, before and after theophylline treatment (1000 mg/day for 3 days, p.o.) was examined.(ABSTRACT TRUNCATED AT 250 WORDS)

Epidermolysis bullosa simplex associated with muscular dystrophy: a new case.

We report an infant with a rare form of epidermolysis bullosa simplex characterized by an autosomal recessive pattern of inheritance, severe cutaneous involvement, oral and nail lesions, associated with muscular dystrophy, and a poor prognosis, due to extracutaneous disease. In addition to the usual presentation of this disease, our patient had severe anemia, with immature circulating white cells, and bone marrow histology suggestive of a pre-leukemic state, a finding which has not before been reported in the literature.

Calcium infusion induces myocardial ischaemia in patients with coronary artery disease by a mechanism possibly adenosine mediated.

In the first part of the study five healthy volunteers were submitted to i.v. infusion of 0.2 mM.kg-1 b.w. of calcium gluconate over 20 min. Total calcium (atomic absorption method), ionized calcium (ion-selective electrode method) and adenosine (HPLC technique) were measured at the following times: 0 (basal), 5, 10, 15, 20 (end of infusion), 25, 30, 35, and 50 min. The increase in total and ionized calcium serum levels was associated with a significant increase in adenosine plasma levels (from 207 +/- 41 to 362 +/- 63 nM.l-1, P < 0.001). Since the increase in adenosine plasma levels, obtained either with adenosine or dipyridamole (an adenosine reuptake inhibitor), has been used to test the coronary reserve in coronary artery disease (CAD) patients, in the second part of the study we compared the effects of calcium infusion with dipyridamole in 15 subjects. Pharmacological stress tests were evaluated by monitoring two-dimensional echocardiography and ECG. Ten patients had positive results with both the dipyridamole stress test and the calcium infusion. Our results show that calcium infusion induces an increase in adenosine plasma levels that can elicit a dipyridamole-like coronary steal, thus suggesting the central role of extracellular adenosine in myocardial ischaemia.

Ito cell heterogeneity: desmin-negative Ito cells in normal rat liver.

The presence of desmin is used to identify Ito cells in rat liver and to evaluate the purity of separated and cultured Ito cells. Heterogeneity of the normal Ito cell population has been suggested; this could include variations in the content of cytoskeletal components. For these reasons we decided to reevaluate the use of desmin staining as a phenotypical marker of Ito cells in normal rat liver. Our approach was to combine desmin staining with identification of vitamin A (autofluorescence), lipid droplets (Sudan III), vimentin, laminin and tenascin, using cryostat sections: Immunofluorescence, double-immunofluorescence or immunoperoxidase techniques were used. All the techniques described corroborate the existence of desmin-negative Ito cells, mainly located in pericentral areas. In fact, lobular desmin-positive cells showed uneven distribution because they were more frequent in periportal than in pericentral areas. On the contrary, Ito cells identified on the basis of morphological criteria or positivity for laminin were evenly distributed. Double immunofluorescence confirmed this observation, showing nearly complete codistribution of laminin and desmin in periportal areas. Outside this area, positivity for desmin was observed only in about 50% of laminin-positive cells. Our observations suggest that desmin cannot be viewed as a phenotypical marker but rather is a differentiation marker of Ito cells, possibly indicating a specific functional state.