[Canine leishmaniasis: evolution of the chemotherapeutic protocols]

Dogs are the domestic reservoir for Leishmania infantum (syn.: L. chagasi), the parasite causing zoonotic visceral leishmaniasis (ZVL) in both the Old and New Worlds. In foci of canine leishmaniasis (CanL), symptomatic disease occurs in less than 50% of infected dogs, and is characterized by chronic evolution of viscero-cutaneous signs. Among strategies recommended to control ZVL, detection and drug treatment of infected dogs are usually employed in the endemic countries of southern Europe. However, the conventional antileishmanial drugs successfully used in human therapy, such as pentavalent antimonials, amphotericin B, pentamidine or miltefosine, have low efficacy in the treatment of CanL. In dogs, these drugs induce only temporary remission of clinical signs, do not prevent occurrence of relapses, and often cause severe side effects. Leishmaniotic dogs may be classified into 4 groups: 1) Asymptomatic resistant dogs ("contacted dogs"), 2) Asymptomatic dogs (preclinical), 3) Dogs with minimal signs of leishmaniasis (oligosymptomatic dogs? Chronic form of leishmaniasis?), 4) Dogs suffering from different forms of clinical leishmaniasis (symptomatic dogs). The dog's immunological status and the associated clinical signs may influence the efficacy of antileishmanial drugs. Subjects belonging to groups 2, 3 and 4 should be always treated, in order to reduce their parasite load. Parameters that must be considered before starting the antileishmanial treatment are hemogram, renal and hepatic functions, electrophoretic protein pattern, antileishmania antibody titres, and bone marrow and lymph node parasite load. The most common antileishmanial drugs currently used in Italy to treat CanL are pentavalent antimonials (meglumine antimoniate) and allopurinol, alone or in combination. Other used drugs are aminosidine (syn.: paromomycin), pentamidine, metronidazole and spyramicin. Each drug regimen has different duration, from a few weeks (aminosidine), to a few months (meglumine antimoniate) or several months (allopurinol). One of the most recent drug used in human VL is liposomal amphotericin B (AmBisome--L-AMB), a powerful antileishmanial drug in both experimental murine models and in VL patients. In Italy, L-AMB is now considered the drug of choice for the treatment of human cases. However, in HIV co-infected patients high doses of L-AMB are ineffective in obtaining a radical cure. In dogs, L-AMB treatment rapidly leads to clinical recovery but is uneffective to eliminate the parasites. Drugs containing amphotericin B should not be used in veterinary practice in order to avoid selection of parasites resistant to the drug, as it already occurred for the pentavalent antimonials. Currently, there is not a standard protocol for CanL treatment in Italy, as there is an extreme variability of proposed dosages. Clinical studies on immunotherapeutics and new antileishmanial drugs, such as miltefosine and its derivates, are in progress.

In vitro and in vivo characterization of MPEP, an allosteric modulator of the metabotropic glutamate receptor subtype 5: review article

There is a need to identify subtype-specific ligands for mGlu receptors to elucidate the potential of these receptors for the treatment of nervous system disorders. To date, most mGlu receptor antagonists are amino acid-like compounds acting as competitive antagonists at the glutamate binding site located in the large extracellular N-terminal domain. We have characterized novel subtype-selective mGlu(5) receptor antagonists which are structurally unrelated to competitive mGlu receptor ligands. Using a series of chimeric receptors and point mutations we demonstrate that these antagonists act as inverse agonists with a novel allosteric binding site in the seven-transmembrane domain. Recent studies in animal models implicate mGlu(5) receptors as a potentially important therapeutic target particularly for the treatment of pain and anxiety.

A new mathematical model based on clinical and laboratory variables for the diagnosis of Sjögren's syndrome

Sjögren's syndrome (SS) is a systemic autoimmune disease that mainly affects exocrine glands. A diagnosis of SS in its early stages has a potential clinical relevance, but it is difficult and cannot be made solely on clinical grounds. Several sets of diagnostic criteria have been proposed, but none has met with a general consensus. Minor salivary gland has been judged to be the "gold standard" for the diagnosis of SS. However, it is a painful procedure and has a small but significant proportion of both false positive and false negative results. The aim of our study was to develop a simple mathematical score that uses clinical and laboratory variables for diagnosing SS, thereby reducing the need of minor salivary gland. The following variables were included in the model: ANA, SS-A/SS-B, Schirmer's Test/BUT, C3/C4, serum gammaglobulin levels. One hundred consecutive individuals reporting clinical syndromes consistent with a sicca syndrome were included in the study. The application of our multifactorial mathematical model has shown a high predictive value for SS vs controls or vs patients with other autoimmune disorders (Sensitivity 93%, Specificity 100%), with an estimated minor salivary gland reduction of 77%. We conclude that our mathematical model can be considered a useful non-invasive approach for diagnosing Sjogren's Syndrome and recommend its validation on a larger scale.

Eccentric atherosclerotic plaques with positive remodelling have a pericardial distribution: a permissive role of epicardial fat? A three-dimensional intravascular ultrasound study of left anterior descending artery lesions

AIMS

The transversal distribution of coronary atherosclerotic plaques (AP) (myocardial vs pericardial) affects vessel remodelling. The aim of this study was to define the impact of transversal lesion distribution on vessel remodelling in proximal and distal coronary segments using a 3D intravascular ultrasound (IVUS) reconstruction.

METHODS

The study group included 70 lesions located in the left anterior descending artery within 5mm of the septal take-off, and imaged using 3D-IVUS. The take-off of the septal branch was used to divide the plaque into a myocardial and pericardial surface. The IVUS index of vessel remodelling was calculated as: [narrowest external elastic membrane (EEM) site cross-sectional area (CSA)-reference EEM CSA)/reference EEM CSAx100]. The lesions with an intermediate vessel remodelling index (between -25% and +15%) were excluded from analysis.

RESULTS

Of the 38 APs with a pericardial distribution, 34 (89%) showed positive remodelling (P<0.001). The distal lesions had a positive vessel remodelling index regardless of transversal plaque distribution. At multivariate analysis, pericardial distribution and the distal location of AP were the only independent variables predictive of positive remodelling.

CONCLUSIONS

The transversal distribution of atherosclerotic plaque affects vessel remodelling in left anterior descending coronary lesions, probably because of an extravascular splinting effect. Distal lesions usually show positive remodelling regardless of transversal plaque distribution.

[Virility examined: andrology between gynaecology and sexual hygiene in a physician of the XVI century]

The paper examines ideas, representations and descriptions of male physiology and pathology in a text written by the physician Giovanni Marinello and published in Venice in 1536. Marinello's successful work, written in Italian and entirely devoted to gynaecological problems, is a short guide for women interested in their own health and in the sexual hygiene of their marriages. Tracing a short history of female diseases, the book offers also interesting issues of andrological interest.

[Relationship between the university and the National Health Services: the experience in northern Italy]

The paper summarises the results of the experiences presented at the "Meeting on Public Health in Northern Regions" held in Milan. Despite the differences seen at local level the importance of interaction between "academic" expertise and field attachment is seen as crucial. Actual legislation pushes toward considering the academic role as a result of the development of teaching, research, health care skills. The paper consider that also a public health doctor in practising should see his role as the result of a mix of "health care, research and teaching" abilities so that a harmonisation looks possible in so far as they know each other and work for the same objectives although in a different context. On the other hand, the University should perceive itself as service given to a community. So, in conclusion, if politics means the common interest in the public affairs this fourth dimension should join the three considered above in general terms and particularly in the field of Public Health Medicine.

Severe pancytopenia and intrahepatic cholestasis in a patient with a history of Hodgkin's disease. Responsiveness to high-dose pulse steroid therapy and diagnosis of a late relapse

A 47-year-old male, treated 7 years earlier for Hodgkin's disease (HD), was admitted with persistent fever, liver enlargement, and increased cholestasis parameters. He developed acute bone marrow failure and progressive worsening of his clinical condition and cholestasis markers without showing evidence of HD recurrence or second malignancy. High-dose intravenous pulse methylprednisolone therapy was given, after which resolution of pyrexia and progressive improvement in performance status and in hematological counts and cholestasis parameters were observed. During this phase, a bone biopsy showed HD marrow infiltration. This clinical course may reflect tumor cytokine-induced phenomena, significantly affected by high-dose steroids.

Decreased serum aminotransferase activity in patients with chronic renal failure: impact on the detection of viral hepatitis

Hepatitis C virus (HCV) infection is common in the dialysis population and patients with chronic renal failure (CRF) not requiring dialysis. HCV is the most important cause of chronic liver disease in dialysis patients; however, its role has been underestimated by the lower aminotransferase activity in the dialysis population. Aminotransferase activity in patients with CRF not requiring dialysis has not been adequately addressed to date. The aim of this study is to investigate whether serum aminotransferase levels in predialysis patients with CRF are less than those obtained in healthy individuals and dialysis patients. We also analyzed the potential association between serum aminotransferase activity and demographic, clinical, and biochemical parameters. Aspartate (AST) and alanine aminotransferase (ALT) activity was greater in antibody to hepatitis C (anti-HCV)-positive than anti-HCV-negative patients with CRF not requiring dialysis (AST, 32.3 +/- 19 versus 18.1 +/- 8 IU/L [P = 0.0001]; ALT, 32.9 +/- 28 versus 17.7 +/- 11 IU/L [P = 0.00001], respectively). Predialysis patients with CRF had lower AST and ALT activity in comparison to healthy individuals (AST, 19.7 +/- 11.2 versus 20.4 +/- 6.8 IU/L [P = 0.00001]; ALT, 19.5 +/- 15.1 versus 21.7 +/- 11.3 IU/L [P = 0.00001], respectively). The difference was much greater after correction for viral markers: AST and ALT levels in hepatitis B surface antigen (HBsAg)-negative anti-HCV-negative predialysis patients with CRF were less than those in the healthy population (AST, 17.9 +/- 8 versus 20.4 +/- 6.8 IU/L [P = 0.00001]; ALT, 17.5 +/- 10 versus 21.7 +/- 11.3 IU/L [P = 0.00001], respectively). Comparison of AST and ALT activity between age-matched healthy and predialysis seronegative CRF groups showed lower AST and ALT values in the study population. HBsAg-negative anti-HCV-negative dialysis patients had lower AST and ALT activity than seronegative predialysis patients with CRF (AST, 16.6 +/- 11.6 versus 17.9 +/- 8 IU/L [P = 0.01]; ALT, 16.3 +/- 9.4 versus 17.5 +/- 10 [P = 0.041], respectively). Multivariate analysis in the predialysis CRF population showed an independent association between AST (P = 0.00001) and ALT (P = 0.00001) activity and anti-HCV positivity, and age was negatively linked to AST (P = 0.011) and ALT levels (P = 0.001). AST level was negatively related to serum creatinine level (P = 0.0001). In conclusion, HCV infection causes significant liver injury in predialysis patients with CRF. These patients have decreased aminotransferase activity compared with the general population. Dialysis patients show lower aminotransferase activity than predialysis patients with CRF. Because serum aminotransferase levels are commonly used to screen for liver disease in the dialysis and predialysis CRF population, recognition of liver damage may be hampered by the reduction in aminotransferase values in these patients. Studies aimed to clarify the pathogenesis of this phenomenon are in progress.

Discovery and characterization of non-competitive antagonists of group I metabotropic glutamate receptors

We have investigated the mechanism of inhibition of the new group I mGluR antagonists CPCCOEt and MPEP and determined that both compounds have a non-competitive mode of inhibition. Furthermore using chimeric/mutated receptors constructs we have found that these antagonists act at a novel pharmacological site located in the trans-membrane (TM). Specific non-conserved amino acid residues in the TM domain have been identified which are necessary for the inhibition by CPCCOEt and MPEP of the mGlul and mGlu5 receptors, respectively. Using molecular modeling a model of the TM domain was built for both mGlu1 and mGlu5 receptor subtypes. Docking of CPCCOEt and MPEP into their respective model allowed the modelisation of the novel binding site.

Rituximab chimeric anti-CD20 monoclonal antibody treatment for adults with chronic idiopathic thrombocytopenic purpura

The role of rituximab, a chimeric monoclonal antibody directed against the CD20 antigen, in the treatment of patients with chronic idiopathic thrombocytopenic purpura (ITP) has not been determined. The effectiveness and side effects of this therapeutic modality were investigated in a cohort of 25 individuals with chronic ITP. All patients had ITP that had been resistant to between 2 and 5 different therapeutic regimens, including 8 patients who had already failed splenectomy. Patients were scheduled to receive intravenous rituximab at the dose of 375 mg/m(2) once weekly for 4 weeks. Rituximab infusion-related side effects were observed in 18 patients, but were of modest intensity and did not require discontinuation of treatment. A complete response (platelet count greater than 100 x 10(9)/L) was observed in 5 cases, a partial response (platelet count between 50 and 100 x 10(9)/L) in 5 cases, and a minor response (platelet count below 50 x 10(9)/L, with no need for continued treatment) in 3 cases, with an overall response rate of 52%. In 7 cases, responses were sustained (6 months or longer). In 2 patients with relapsed disease, repeat challenge with rituximab induced a new response. In patients with a complete or partial response, a significant rise in platelet concentrations was observed early during the course of treatment, usually 1 week after the first rituximab infusion. No clinical or laboratory parameter was found to predict treatment outcome, although there was a suggestion that women and younger patients have a better chance of response. In conclusion, rituximab therapy has a limited but valuable effect in patients with chronic ITP. In view of its mild toxicity and the lack of effective alternative treatments, its use in the setting of chronic refractory ITP is warranted. (Blood. 2001;98:952-957)

Acute and mid-term results of phosphorylcholine-coated stents in primary coronary stenting for acute myocardial infarction

The aim of this pilot study was to evaluate the safety and efficacy of the BiodivYsio phosphorylcholine-coated stent in the primary treatment of acute myocardial infarction. The BiodivYsio stent (Biocompatible) is a balloon-expandable stent, laser etched from a 316 L stainless steel tube. This device is coated with phosphorylcholine, a synthetic, hemocompatible phospholipid polymer that has been shown in experimental studies to reduce platelet and protein adhesion to the surface of the metal. One hundred consecutive patients within 24 hr of symptoms of onset of acute MI, treated with primary PTCA, were enrolled. After PTCA, stenting was attempted in all eligible lesions (reference diameter > or = 2.5 mm; no bend lesion > 45 degrees ). Poststenting regimens contained ticlopidine (500 mg/day) and aspirin (325 mg/day) and 6-12 hr of heparin infusion. Procedural success (TIMI > or = II and residual stenosis < 30%) was obtained in 70/74 cases (95%). TIMI grade III was restored in 90% of cases. In the patient group with procedural success (70 cases), 70 BiodivYsio stents were placed. After stenting, diameter stenosis decreased from 96% +/- 11% to 22% +/- 12% (P < 0.01) and minimal luminal diameter increased from 0.13 +/- 0.29 to 2.47 +/- 0.43 (P < 0.01). Nominal stent diameter was between 3.0 and 4.0 mm (mean, 3.5 +/- 0.4 mm). Stent length was between 11 and 28 mm (mean, 17 +/- 4.5 mm). Clinical follow-up was obtained in all patients; angiographic follow-up was performed in 65/70 (93%). No acute or subacute thrombosis was reported. Two in-hospital major adverse cardiac events (MACE) were reported due to a nontreated left main disease that required coronary artery bypass graft (CABG) surgery. At follow-up, MACE were found in 9 of 68 patients (13%), target lesion revascularization (TLR) in 6%, and CABG in the remaining 6%. Primary stenting with phosphorylcholine-coated stent leads to excellent short- and mid-term clinical outcomes and is associated with a restenosis rate of 12%.

Correlation between high frequency intravascular ultrasound and histomorphology in human coronary arteries

OBJECTIVE

To test the efficacy of high frequency intravascular ultrasound (IVUS) transducers in identifying lipid/necrotic pools in atherosclerotic plaques.

METHODS

40 MHz transducers were used for in vitro IVUS assessment of 12 arterial segments (10 coronary and two carotid arteries, dissected from five different necropsy cases). IVUS acquisition was performed at 0.5 mm/s after ligature of the branching points to generate a closed system. Lipid/necrotic areas were defined by IVUS as large echolucent intraplaque areas surrounded by tissue with higher echodensity. To obtain histopathological sections corresponding to IVUS cross sections, vessels were divided into consecutive 3 mm long segments using the most distal recorded IVUS image as the starting reference. Samples were then fixed with 10% buffered formalin, processed for histopathological study, serially cut, and stained using the Movat pentacrome method.

RESULTS

122 sections were analysed. Lipid pools were observed by histology in 30 sections (25%). IVUS revealed the presence of lipid pools in 19 of these sections (16%; sensitivity 65%, specificity 95%).

CONCLUSIONS

In vitro assessment of lipid/necrotic pools with high frequency transducers was achieved with good accuracy. This opens new perspectives for future IVUS characterisation of atherosclerotic plaques.

Correlation between high frequency intravascular ultrasound and histomorphology in human coronary arteries

OBJECTIVE

To test the efficacy of high frequency intravascular ultrasound (IVUS) transducers in identifying lipid/necrotic pools in atherosclerotic plaques.

METHODS

40 MHz transducers were used for in vitro IVUS assessment of 12 arterial segments (10 coronary and two carotid arteries, dissected from five different necropsy cases). IVUS acquisition was performed at 0.5 mm/s after ligature of the branching points to generate a closed system. Lipid/necrotic areas were defined by IVUS as large echolucent intraplaque areas surrounded by tissue with higher echodensity. To obtain histopathological sections corresponding to IVUS cross sections, vessels were divided into consecutive 3 mm long segments using the most distal recorded IVUS image as the starting reference. Samples were then fixed with 10% buffered formalin, processed for histopathological study, serially cut, and stained using the Movat pentacrome method.

RESULTS

122 sections were analysed. Lipid pools were observed by histology in 30 sections (25%). IVUS revealed the presence of lipid pools in 19 of these sections (16%; sensitivity 65%, specificity 95%).

CONCLUSIONS

In vitro assessment of lipid/necrotic pools with high frequency transducers was achieved with good accuracy. This opens new perspectives for future IVUS characterisation of atherosclerotic plaques.

Metabotropic glutamate receptor subtype 5 (mGlu5) and nociceptive function. I. Selective blockade of mGlu5 receptors in models of acute, persistent and chronic pain

The excitatory neurotransmitter, glutamate, is particularly important in the transmission of pain information in the nervous system through the activation of ionotropic and metabotropic glutamate receptors. A potent, subtype-selective antagonist of the metabotropic glutamate-5 (mGlu5) receptor, 2-methyl-6-(phenylethynyl)-pyridine (MPEP), has now been discovered that has effective anti-hyperalgesic effects in models of inflammatory pain. MPEP did not affect rotarod locomotor performance, or normal responses to noxious mechanical or thermal stimulation in naïve rats. However, in models of inflammatory pain, systemic administration of MPEP produced effective reversal of mechanical hyperalgesia without affecting inflammatory oedema. In contrast to the non-steroidal anti-inflammatory drugs, indomethacin and diclofenac, the maximal anti-hyperalgesic effects of orally administered MPEP were observed without acute erosion of the gastric mucosa. In contrast to its effects in models of inflammatory pain, MPEP did not produce significant reversal of mechanical hyperalgesia in a rat model of neuropathic pain.

C-terminal interaction is essential for surface trafficking but not for heteromeric assembly of GABA(b) receptors

Assembly of fully functional GABA(B) receptors requires heteromerization of the GABA(B(1)) and GABA(B(2)) subunits. It is thought that GABA(B(1)) and GABA(B(2)) undergo coiled-coil dimerization in their cytoplasmic C termini and that assembly is necessary to overcome GABA(B(1)) retention in the endoplasmatic reticulum (ER). We investigated the mechanism underlying GABA(B(1)) trafficking to the cell surface. We identified a signal, RSRR, proximal to the coiled-coil domain of GABA(B(1)) that when deleted or mutagenized allows for surface delivery in the absence of GABA(B(2)). A similar motif, RXR, was recently shown to function as an ER retention/retrieval (ERR/R) signal in K(ATP) channels, demonstrating that G-protein-coupled receptors (GPCRs) and ion channels use common mechanisms to control surface trafficking. A C-terminal fragment of GABA(B(2)) is able to mask the RSRR signal and to direct the GABA(B(1)) monomer to the cell surface, where it is functionally inert. This indicates that in the heteromer, GABA(B(2)) participates in coupling to the G-protein. Mutagenesis of the C-terminal coiled-coil domains in GABA(B(1)) and GABA(B(2)) supports the possibility that their interaction is involved in shielding the ERR/R signal. However, assembly of heteromeric GABA(B) receptors is possible in the absence of the C-terminal domains, indicating that coiled-coil interaction is not necessary for function. Rather than guaranteeing heterodimerization, as previously assumed, the coiled-coil structure appears to be important for export of the receptor complex from the secretory apparatus.

Pulsed intravenous high-dose dexamethasone in adults with chronic idiopathic thrombocytopenic purpura

The role of pulsed high-dose dexamethasone (DXM) in the treatment of patients with chronic idiopathic thrombocytopenic purpura (ITP) is still uncertain. Following an early report in which it was described as an effective and well-tolerated treatment with a sustained platelet response in 100% of cases, a number of subsequent studies have failed to confirm such favorable results. As all these studies were conducted on small numbers of patients, we investigated further the effectiveness and side effects of this therapeutic modality in a larger cohort. Thirty-two patients with chronic ITP were scheduled to receive six monthly courses of intravenous DXM at the dose of 40 mg/day for 4 consecutive days. All patients had ITP that had been resistant to between two and five different therapeutic regimens, including 9 patients who had already failed splenectomy. All patients had to be seen 2 weeks after each cycle to asses their response as well as secondary effects. Three patients failed to respond and clinically required other therapy. Thirteen patients (41%) had a partial (platelet count between 50 and 100 x 10(9)/liter) or complete (platelet count >100 x 10(9)/liter) response to treatment, responses being mostly transient. Responses were observed early during the course of treatment, usually right after the first cycle of DXM. There were no late responses. Side effects were mild and did not require discontinuation of treatment. No clinical or laboratory parameter was found to predict treatment outcome. We conclude that high-dose DXM has a limited effect in patients with chronic ITP. Novel approaches and controlled multicenter trials may help identify new therapeutic strategies for this disease.

[Autonomic neuropathy in a diabetic population. Validity of cardiovascular tests and correlations with the complications]

The disfunction of the autonomic system nervous is a frequent finding in diabetes mellitus. Among objective tests proposed for its diagnosis, those assessing cardiovascular reflexes (cardiovascular tests: CVTs) explore the autonomic functionality by means of a group of standardized manoeuvres of relatively easy execution that study the baroreceptorial reflex arc. In our study, CVTs were performed in a population of 207 diabetic patients with no symptoms of autonomic neuropathy. A computerized automatic system (Cardionomic) was utilized. CTVs included: Deep Breathing, Lying to Standing, Valsalva Manoeuvre, Orthostatic Hypotension, Standing to Lying and Cough Test. Diabetic patients were broken down in groups according to: a) age, b) HbA1c levels, c) disease duration. We have then compared the presence of diabetic complications between the group of diabetics positive for cardiovascular disautonomia (CVD+) with another group of diabetics who were negative for cardiovascular disautonomia (DCV-). Our results show a remarkable correlation between autonomic neuropathy and patients age, HbA1c levels and disease duration. Also they show a strong positive correlation between CDV+ and the severity of arteriopathy. We conclude that autonomic neuropathy may play an important role in the pathogenesis of diabetic arteriopathy.

Variations in call and morphology in male water frogs: taxonomic and evolutionary implications

In Anurans, the specific mate recognition system (SMRS), which contributes to prezygotic isolation, is mainly based on morphological and call features. This is why such criteria are used by zoologists for taxonomic identification. In hybridogenetic water frogs (Rana ridibunda, R. lessonae, R. perezi, R. kl. grafi and R. kl. esculenta), hybridization opens up the question of the efficiency of these criteria for taxon identification and of the specific recognition system in this context. Variation in both morphological and call features revealed both significant mean differences among taxa but also large overlapping among individuals belonging to different taxa. Thus, using call or morphometrical features in order to identify water frogs may be hazardous. Moreover, species differ poorly in their specific mate recognition system, facilitating hybridization events, and therefore suggesting that postzygotic mechanisms may be prevalent over prezygotic mechanisms.

The non-competitive antagonists 2-methyl-6-(phenylethynyl)pyridine and 7-hydroxyiminocyclopropan[b]chromen-1a-carboxylic acid ethyl ester interact with overlapping binding pockets in the transmembrane region of group I metabotropic glutamate receptors

We have investigated the mechanism of inhibition and site of action of the novel human metabotropic glutamate receptor 5 (hmGluR5) antagonist 2-methyl-6-(phenylethynyl)pyridine (MPEP), which is structurally unrelated to classical metabotropic glutamate receptor (mGluR) ligands. Schild analysis indicated that MPEP acts in a non-competitive manner. MPEP also inhibited to a large extent constitutive receptor activity in cells transiently overexpressing rat mGluR5, suggesting that MPEP acts as an inverse agonist. To investigate the molecular determinants that govern selective ligand binding, a mutagenesis study was performed using chimeras and single amino acid substitutions of hmGluR1 and hmGluR5. The mutants were tested for binding of the novel mGluR5 radioligand [(3)H]2-methyl-6-(3-methoxyphenyl)ethynyl pyridine (M-MPEP), a close analog of MPEP. Replacement of Ala-810 in transmembrane (TM) VII or Pro-655 and Ser-658 in TMIII with the homologous residues of hmGluR1 abolished radioligand binding. In contrast, the reciprocal hmGluR1 mutant bearing these three residues of hmGluR5 showed high affinity for [(3)H]M-MPEP. Radioligand binding to these mutants was also inhibited by 7-hydroxyiminocyclopropan[b]chromen-1a-carboxylic acid ethyl ester (CPCCOEt), a structurally unrelated non-competitive mGluR1 antagonist previously shown to interact with residues Thr-815 and Ala-818 in TMVII of hmGluR1. These results indicate that MPEP and CPCCOEt bind to overlapping binding pockets in the TM region of group I mGluRs but interact with different non-conserved residues.

[Epidemiologic study and cost analysis of an Slamonella enteritidis epidemic]

Salmonellosis is one of the most common forms of foodborne infection. An outbreak of gastroenteritidis associated with a wedding party was investigated, even to value the costs falling on individuals, the health services and society as a whole. One hundred and fifty nine wedding guests were interviewed by phone. Multivariate analysis was used to assess which food were significantly associated with infection. One hundred and thirteen cases were identified; ten stool samples were culture positive for Salmonella enteritidis. Handmade ice-cream and babà (a typical Italian pastry) were significantly associated with infection. The cost of a case was estimated to be between US $ 74 (for non hospitalised patients) and US $ 1,896 (for hospitalised patients). The outbreak was caused by a strain of Salmonella enteritidis and the vehicle of infection were unpasteurised eggs used to prepare the ice-cream. The economic impact of this outbreak was considerable and mainly due to the hospitalisation.

COPI-coated ER-to-Golgi transport complexes segregate from COPII in close proximity to ER exit sites

Transport of proteins between the endoplasmic reticulum and Golgi apparatus is mediated by two distinct membrane coat complexes, COPI and COPII. Genetic, biochemical and morphological data have accumulated into a model which suggests a sequential mode of action with COPII mediating the selection of cargo and formation of transport vesicles at the ER membrane for ER-to-Golgi transport and COPI mediating recycling of the transport machinery from post-ER membranes. To test this transport model directly in vivo, and to study the precise temporal sequence of COPI and COPII action in ER-to-Golgi transport, we have used time lapse microscopy of living cells to visualise simultaneously the dynamics of COPII and COPI, as well as COPII and GFP tagged secretory markers in living cells. The majority of COPII labelling appears tightly associated with ER membranes that move only within a limited area (less than 2 microm). Secretory cargo segregates from these sites and is then transported to the Golgi apparatus without any apparent association with COPII. COPI-coated transport complexes are seen to form adjacent to the COPII sites on the ER before segregating and moving directionally towards the Golgi apparatus. COPII is not present on these transport complexes and remains associated with the ER. These data demonstrate for the first time directly in vivo that ER-to-Golgi transport is organised in two steps characterised by a sequential mode of action of COPII and COPI.