Usutu virus in blackbirds (Turdus merula) with clinical signs, a case study from northern Italy

Usutu virus (USUV) is a mosquito-borne virus belonging to the family Flaviviridae, genus Flavivirus. Natural transmission cycle of USUV involves mosquitoes and birds, so humans and other mammals are considered incidental hosts. In this study, USUV infection was diagnosed in all wild blackbirds, collected from July to September 2018 in a wildlife recovery center in the province of Bologna, in the Emilia-Romagna region, northern Italy. All blackbirds showed neurological clinical signs, such as overturning, pedaling, and incoordination. Moreover, the subjects died shortly after arriving at the hospitalization center. Virological investigations were performed by real-time PCR on frozen samples of the spleen, kidney, myocardium, and brain for the detection of Usutu (USUV) and West Nile (WNV) viruses. The small and large intestine were used as a matrix for the detection of Newcastle disease virus (NDV). All 56 subjects with neurological clinical signs were positive for USUV, only one subject (1.8%) tested positive for WNV, and no subject was positive for NDV. The most represented age class was class 1 J (58.9%), followed by class 3 (25.0%), and lastly from class 4 (16.1%). Most of the blackbirds before dying were in good (51.8%) and fair (39.3%) nutritional status, while only five subjects (8.9%) were cachectic. The USUV genomes detected in the blackbirds of this study fall within the sub-clade already called EU2 that has been detected since 2009 in the Emilia-Romagna region. Neurological clinical signs in USUV-affected blackbirds are still widely discussed and there are few works in the literature. Although our results require further studies, we believe them to be useful for understanding the clinical signs of Usutu virus in blackbirds, helping to increase the knowledge of this zoonotic agent in wild species and to understand its effect on the ecosystem. The goal of this study was to report—in the context of the regional passive surveillance program—the detection of USUV RNA in its most important amplifying host, the common blackbird, when showing clinical signs before death.

Short communication: Seroprevalence of paratuberculosis in Italian water buffaloes (Bubalus bubalis) in the region of Campania

Paratuberculosis is a chronic enteric disease affecting virtually all ruminants, but only anecdotal information is currently available about the occurrence of this disease in water buffaloes (Bubalus bubalis). We carried out a survey study aimed at determining the prevalence of paratuberculosis in 2 provinces in the region of Campania, Italy, where about half of all Italian buffaloes are reared. From May 2017 to December 2018, we collected 201,175 individual serum samples from 995 buffalo herds. The sera were collected from animals over 24 mo old and were tested using a commercial ELISA test. The herd-level apparent prevalence result was 54.7%, and the animal-level apparent prevalence was 1.8%. The herd-level true prevalence was estimated using a Bayesian approach, demonstrating a high herd-level prevalence of paratuberculosis in water buffaloes from the Campania area. These findings suggest that the urgent adoption of paratuberculosis herd-control programs for water buffaloes in this area would be beneficial.

A method to identify the areas at risk for the introduction of avian influenza virus into poultry flocks through direct contact with wild ducks

Wild dabbling ducks are the main reservoir for avian influenza (AI) viruses and pose an ongoing threat to commercial poultry flocks. Combining the (i) size of that population, (ii) their flight distances and (iii) their AI prevalence, the density of AI-infected dabbling ducks (DID) was calculated as a risk factor for the introduction of AI viruses into poultry holdings of Emilia-Romagna region, Northern Italy. Data on 747 poultry holdings and on 39 AI primary outbreaks notified in Emilia-Romagna between 2000 and 2017 were used to validate that risk factor. A multivariable Bayesian logistic regression was performed to assess whether DID could be associated with the occurrence of AI primary outbreaks. DID value, being an outdoor flock, hobby poultry trading, species reared, length of cycle and flock size were used as explanatory variables. Being an outdoor poultry flock was significantly associated with a higher risk of AI outbreak occurrence. The probability of DID to be a risk factor for AI virus introduction was estimated to be 90%. A DID cut-off of 0.23 was identified to define high-risk areas for AI virus introduction. Using this value, the high-risk area covers 43% of the region. Seventy-four per cent of the primary AI outbreaks have occurred in that area, containing 39% of the regional poultry holdings. Poultry holdings located in areas with a high DID value should be included in a risk-based surveillance programme aimed at AI early detection.

Human and entomological surveillance of Toscana virus in the Emilia-Romagna region, Italy, 2010 to 2012

Toscana virus (TOSV), transmitted by phlebotomine sandflies, is recognised as one of the most important causes of viral meningitis in summer in Mediterranean countries. A surveillance plan based on both human and entomological surveys was started in 2010 in the Emilia-Romagna region, Italy. Clinical samples from patients with neurological manifestations were collected during 2010 to 2012. The surveillance protocol was improved during these years, allowing the detection of 65 human infections. Most of these infections were recorded in hilly areas, where sandflies reach the highest density. Entomological sampling around the homes of the patients resulted in a low number of captured sandflies, while later sampling in a hilly area with high number of human cases (n=21) resulted in a larger number of captured sandflies. Using this approach, 25,653 sandflies were sampled, of which there were 21,157 females, which were sorted into 287 pools. TOSV RNA was detected by real-time PCR in 33 of the pools. The results highlighted the role of Phlebotomus perfiliewi as the main vector of TOSV and a potential link between vector density and virus circulation. This integrated system shows that an interdisciplinary approach improves the sensitiveness and effectiveness of health surveillance.

The experience of West Nile virus integrated surveillance system in the Emilia-Romagna region: five years of implementation, Italy, 2009 to 2013

Predicting West Nile virus (WNV) circulation and the risk of WNV epidemics is difficult due to complex interactions of multiple factors involved. Surveillance systems that timely detect virus activity in targeted areas, and allow evidence-based risk assessments may therefore be necessary. Since 2009, a system integrating environmental (mosquitoes and birds) and human surveillance has been implemented and progressively improved in the Emilia-Romagna region, Italy. The objective is to increase knowledge of WNV circulation and to reduce the probability of virus transmission via blood, tissue and organ donation. As of 2013, the system has shown highly satisfactory results in terms of early detection capacity (the environmental surveillance component allowed detection of WNV circulation 3–4 weeks before human cases of West Nile neuroinvasive disease (WNND) occurred), sensitivity (capacity to detect virus circulation even at the enzootic level) and area specificity (capacity to indicate the spatial distribution of the risk for WNND). Strong correlations were observed between the vector index values and the number of human WNND cases registered at the province level. Taking into consideration two scenarios of surveillance, the first with environmental surveillance and the second without, the total costs for the period from 2009 to 2013 were reduced when environmental surveillance was considered (EUR 2.093 million for the first scenario vs EUR 2.560 million for the second). Environmental surveillance helped to reduce costs by enabling a more targeted blood unit testing strategy. The inclusion of environmental surveillance also increased the efficiency of detecting infected blood units and further allowed evidence-based adoption of preventative public health measures.

Canine leishmaniasis surveillance in a northern Italy kennel

An epidemiological survey on canine leishmaniasis (CanL) was performed during a 3-year period (2007-2009) in a public kennel of the Bologna province. The presence of the disease was shown in the canine population for the first time in 2007 by indirect fluorescent antibody test (IFAT). The parasite circulation was confirmed also by direct diagnostic tools, as PCR, cytology and cultural method, performed on different bioptic materials. The parasite was isolated and identified as Leishmania infantum zymodeme MON 1. The serological monitoring was performed also in 2008 and 2009 on animals that previously showed negative or uncertain results. The incidence values calculated by significant seroconversions in IFAT titre ≥ 1/160, ranged between 4.9% and 6.6%, indicating a stable focus of leishmaniasis. The entomological survey, performed by sticky and CO(2)-baited traps in 2008, showed the presence of the vector Phlebotomus perfiliewi. This study allowed us to identify a stable focus of CanL in an area that was not considered eco-compatible with the presence of the vector and infection. Our results confirm the northward spread of CanL towards areas not previously affected by autochthonous foci.

West Nile virus circulation in Emilia-Romagna, Italy: the integrated surveillance system 2009

Following a large West Nile virus (WNV) epidemic in northeastern Italy in 2008, human and animal surveillance activities were implemented in Emilia Romagna. Human surveillance was performed by serology or genome detection on blood and cerebrospinal fluid for all suspected cases suffering from acute meningoencephalitis in the regional territory. Animal surveillance consisted of passive and active surveillance of horses and active surveillance of wild birds and mosquitoes. Between 15 June and 31 October 2009, nine of 78 possible cases of West Nile neuroinvasive disease were confirmed (three fatal). From May to October, 26 cases of neurological West Nile disease were confirmed among 46 horses. The overall incidence of seroconversion among horses in 2009 was 13%. In 2009, 44 of 1,218 wild birds yielded positive PCR results for WNV infection. The planned veterinary and entomological surveillance actions detected WNV activity from the end of July 2009, about 2-3 weeks before the onset of the first human neurological case. Passive surveillance of horses seems to be an early and suitable tool for the detection of WNV activity, but it will be less sensitive in the future, because an intensive programme of horse vaccination started in June 2009.

West Nile virus circulation in Emilia-Romagna, Italy: the integrated surveillance system 2009

Following a large West Nile virus (WNV) epidemic in northeastern Italy in 2008, human and animal surveillance activities were implemented in Emilia Romagna. Human surveillance was performed by serology or genome detection on blood and cerebrospinal fluid for all suspected cases suffering from acute meningoencephalitis in the regional territory. Animal surveillance consisted of passive and active surveillance of horses and active surveillance of wild birds and mosquitoes. Between 15 June and 31 October 2009, nine of 78 possible cases of West Nile neuroinvasive disease were confirmed (three fatal). From May to October, 26 cases of neurological West Nile disease were confirmed among 46 horses. The overall incidence of seroconversion among horses in 2009 was 13%. In 2009, 44 of 1,218 wild birds yielded positive PCR results for WNV infection. The planned veterinary and entomological surveillance actions detected WNV activity from the end of July 2009, about 2-3 weeks before the onset of the first human neurological case. Passive surveillance of horses seems to be an early and suitable tool for the detection of WNV activity, but it will be less sensitive in the future, because an intensive programme of horse vaccination started in June 2009.

West Nile virus transmission in 2008 in north-eastern Italy

After 10 years, West Nile virus (WNV) re-emerged in Italy in August 2008. As on 31 December 2008, the infection affected eight Provinces in three Regions (Emilia Romagna, Veneto, Lombardy), where a total of 794 cases of WNV infection in 251 equine stables were detected on the basis of the clinical signs and as a result of a serological screening in horses living in the area. Only 4.0% (32/794) of the serologically positive animals showed clinical signs, and the 32 clinical cases were reported in 18 different farms. The observed case-fatality rate was 15.6% (5/32). The confirmed clinical cases were detected from end August to mid October. Significant levels of positivity by RT-PCR were also observed in magpies (Pica pica) (9.1%, 95% confidence levels: 6.1-13.4%), carrion crows (Corvus corone) (7.4%, 95% confidence levels: 3.6-14.4%) and rock pigeons (Columba livia) (12.9%, 95% confidence levels: 7.6-21.2%).

Detection of West Nile virus infection in horses, Italy, September 2008

Six confirmed and five suspected cases of West Nile virus infection in horses have been reported in the vicinity of Ferrara in Italy. To verify the diffusion of viral circulation and to prevent the spread of disease, the regional authorities of Emilia-Romagna adopted a special plan of West Nile fever surveillance.

Prevalence of Salmonella enterica and Listeria monocytogenes contamination in foods of animal origin in Italy

The present survey collected and analyzed the results of routine testing for Salmonella enterica and Listeria monocytogenes on foods of animal origin submitted for official controls in Italy during 2001 to 2002. Salmonella was detected in 2.2% of 71,643 food samples examined, and the isolation rates ranged from 9.9% for raw poultry meat to less than 0.1% for dairy products. Isolation rates were also high in raw pork (4.9%) and processed meats (5.3%), which often involved pork. Low rates were observed in seafood (0.5%) and in ready-to-eat foods, such as grocery products (0.7%) and ice creams (0.1%). Serotyping showed that approximately 50% of the isolates belonged to the serotypes most commonly isolated from humans in Italy, thus confirming that most cases of human salmonellosis have a foodborne origin. Levels of L. monocytogenes were higher than what is accepted by the current regulation in 2.4% of 42,300 food samples. The positivity rates ranged from 10.3% in raw pork to none in eggs and egg products. Contamination rates were higher in other meat products (between 2 and 5%) and fish (6.5%) than in cheeses (1.1%) and other dairy products (0.6%). Routine control activities on the microbial contamination of foods can generate data with statistical and epidemiological value. Such data can be used as a basis for estimating the exposure of consumers to foodborne pathogens, following the trends of contamination over time, and evaluating the effects of control measures on the contamination of food.

Bluetongue control using vaccines: the experience of Emilia Romagna, Italy

In 2003, thirty municipalities of the provinces of Parma, Reggio Emilia and Modena in the Emilia Romagna region of Italy, bordering the region of Tuscany, were included in the national bluetongue (BT) vaccination programme, using monovalent live-attenuated type 2 vaccine. The purpose of the study was to evaluate the organisation of a vaccination programme designed by the Regional Veterinary Service and the relative cost of the campaign, as a large number of animals were involved. To better evaluate the real cost of the campaign, costs sustained by the Reggio Emilia Local Sanitary Unit were specifically analysed. BT vaccination of all domestic ruminants is a very expensive operation (euro9.20 per vaccinated animal). Consequently, to evaluate the need for a vaccination campaign in a new area, the risk of disease spread, as well as the cost of the operation, should be considered.

Raman and IR study on copper binding of histamine

A comparative Raman and FTIR study of histamine (Hm), a small hormone present in a wide selection of living organisms, and its complexes with copper(II) at different pH values was carried out. Both the Raman and IR spectra present some marker bands useful for the identification of the structure of the species predominating in the Cu(II) aqueous and alcoholic systems. In particular, Raman spectroscopy appears to be a useful tool for analyzing the tautomeric equilibrium of the imidazole ring of Hm, because some bands (i.e., nuC(4)dbond;C(5)) appear at different wavenumbers, depending on whether the imidazole moiety is in the N(tau)-H (tautomer I) or N(pi)-H (tautomer II) protonated form. In aqueous solutions the manner in which Hm binds to Cu(II) depends on the pH. At basic pH the most relevant species formed are a dimer, [Cu(2)L(2)H(-2)](2+), and a monomeric complex, [CuL](2-) or [CuL(2)](+). On the contrary, by decreasing the pH, Hm acts as a mono- or bidentate ligand, giving rise to two types of monomeric complexes, [CuLH](2-) and [CuL](2-) or [CuL(2)](+). With respect to the Cu(II)-Hm alcoholic system, both the aminic group and the imidazole ring (tautomer I) take part in the Cu(II) coordination, leading to the formation of the [CuL](2-) or [CuL(2)](+) monomeric complex.

Role of cystine transport in intracellular glutathione level and cisplatin resistance in human ovarian cancer cell lines

Transport system x(c)(-) is a member of plasma membrane heterodimeric amino-acid transporters and consists of two protein components, xCT and 4F2hc. This system mediates cystine entry coupled with the exodus of intracellular glutamate and regulates the intracellular glutathione (GSH) levels in most mammalian cultured cells. We studied the activity of system x(c)(-) and GSH content in human ovarian cancer cell line (A2780) and its cisplatin (CDDP)-resistant variant (A2780DDP). The rate of cystine uptake was approximately 4.5-fold higher in A2780DDP cells than in A2780 cells and the cystine uptake in A2780DDP cells was mediated by system x(c)(-). Intracellular GSH content was much higher in A2780DDP cells but it fell drastically in the presence of excess glutamate, which inhibited the cystine uptake competitively. xCT and 4F2hc mRNAs were definitely expressed in A2780DDP cells, but far less in A2780 cells. Expression of system x(c)(-) activity by transfection with cDNAs for xCT and 4F2hc made A2780 cells more resistant to CDDP. Similar results on the cystine uptake were obtained in human colonic cancer cell lines. These findings suggest that the system x(c)(-) plays an important role in maintaining the higher levels of GSH and consequently in CDDP resistance in cancer cell lines.

Risk factors for Aujeszky's-disease seropositivity of swine herds of a region of northern Italy

Vaccination programs to control Aujeszky's-disease virus (ADV) using gE-deleted vaccines are being considered in several European countries. Knowledge of factors influencing ADV-seropositivity for vaccinated herds might contribute to the success of these programs. A multivariable analysis of ADV-seropositivity in 1248 swine herds (332 farrow-to-finish, 260 farrow-to-feeder and 656 finishing herds) in the Emilia-Romagna region of Italy revealed that (1) high pig density (number of pigs in a 6-km radius), (2) gilt purchasing, and (3) increased number of fattening pigs were risk factors for farrow-to-finish herds. In farrow-to-feeder herds, ADV-seropositivity was related to (1) increased number of breeders, (2) heavy-gilt purchasing, and (3) increased pig density. In finishing herds, (1) increased herd size was related to ADV-seropositivity, whereas (2) periodic rearing suspension was protective.

Efficacy and safety of an initial daily dosing regimen of interferon-alpha-2a in treatment-naive patients with chronic hepatitis C and HCV genotype 1

Between January 1996 and February 1999 we treated two groups of patients with chronic hepatitis C and HCV genotype 1 according to different treatment regimens. 29 patients in group were treated in a prospective, open trial and received an initial dose of 6 MU Interferon-alpha-2a daily. In case of virologic response within the first 12 weeks of treatment a dosage reduction to 6 MU three times weekly was performed until the end of week 12 and 3 MU three times weekly thereafter until the completion of month 12. 35 patients in group 2 received 5 MU (Interferon-alpha-2b) or 6 MU (Interferon-alpha-2a) three times a week. If serum HCV RNA was negative after three months of treatment patients received 3 MU thrice weekly until completion of month 12. This regimen was considered standard therapy at the time of treatment. In both groups therapy was stopped in patients in whom HCV RNA remained detectable after 12 weeks of treatment or in patients who underwent virological breakthrough. The end point was a sustained virologic response defined as the absence of serum HCV RNA 6 months after treatment was completed. Primary response rates as defined by negative serum HCV RNA within the first 12 weeks of treatment were 59% in group 1 and 17% in group 2. Sustained response rates were 10% in group 1 and 3% in group 2. Initial daily dosing as in group 1 was therefore not associated with a higher sustained response rate compared to standard therapy. The safety profile was in accordance with the known side effects of interferon-alpha and was comparable in both treatment groups.

Binding of copper(II) to carnosine: Raman and IR spectroscopic study

A comparative Raman and FTIR study of carnosine, a dipeptide present in several mammalian tissues, and its complexes with copper(II) at different pH values was carried out. The neutral imidazole ring gives rise to some bands that appear at different wavenumbers, depending on whether the imidazole ring is in the tautomeric form II or I. At pH 7 and 9 the molecule exists in equilibrium between the two tautomeric forms; tautomer I is predominant. Metal coordination is a factor that affects the tautomeric equilibrium, and the copper(II) coordination site can be monitored by using some Raman marker bands such as the vC(4)=C(5) band. On the basis of the vibrational results, conclusions can be drawn on the functional groups involved in the Cu(II) chelation and on the species existing in the Cu(II)-carnosine system. At neutral and basic pH the most relevant species formed when the Cu(II)/carnosine molar ratio is not very different from unity is a dimer, [Cu(2)L(2)H(-2)](0). In this complex the ligand coordinates the metal via the N (amino), O (carboxylate), and N (amide) donor atoms while the N(tau) nitrogen atoms of the imidazole rings (tautomer II) bridge the copper(II) ions. At a slightly acidic pH the two monomeric complexes [CuLH](2+) and [CuL](+) were present. In the former the imidazole ring takes part in the Cu(II) coordination in the tautomeric I form whereas in the latter it is protonated and not bound to Cu(II).

Free radical scavenging and copper chelation: a potentially beneficial action of captopril

Captopril (CpSH), an angiotensin converting enzyme (ACE) inhibitor, is reported to provide protection against free-radical mediated damage. The purpose of this study was to investigate, by means of pulse radiolysis technique, the behaviour of CpSH towards radiation-induced radicals in the absence and in the presence of copper(II) ions, which can play a relevant role in the metal catalysed generation of reactive oxygen species. The results indicate that the -SH group is crucial in determining the radical scavenging action of CpSH and the nature of the resulting CpSH transient products in the absence or in the presence of oxygen. In the presence of Cu(II), the -SH group is still involved in the biological action of the molecule participating both in the one-electron reduction of Cu(II) with formation of CpSSCp, and in Cu(I) chelation. This conclusion is supported by the Raman spectroscopic data which allow to identify the CpSH sites involved in the copper complex at different pH. These results suggest that CpSH may potentially inhibit oxidative damage both through free radical scavenging and metal chelation. Considering the low CpSH concentration in vivo, the metal chelation mechanism, more than the direct radical scavenging, could play the major role in moderating the toxicological effects of free radicals.

Molecular cloning and expression of human xCT, the light chain of amino acid transport system xc-

Transport of system xc- is an exchange agency with high specificity for anionic form of cystine and glutamate. The protein mediating this transport is a disulfide-linked heterodimer of a light chain named xCT and a heavy chain previously known as 4F2hc. We have isolated two cDNAs encoding xCT from the human cDNA library. One clone coded for a protein of 501 amino acids with 12 putative transmembrane domains. When functionally expressed in Xenopus oocytes together with the human 4F2hc, human xCT induced the transport activity whose characteristics are similar to those of system xc-. Another clone seemed to contain a partial human xCT and a long 3' untranslated region. The human xCT gene was localized at chromosome 4q28-31. Analysis of the 5'-flanking region of the human xCT gene revealed several sites for potentially binding of transcriptional factors, including NF-E2 and AP-1. Transport of cystine via system xc- has been known as a regulatory factor for the intracellular glutathione level, and its transport activity is induced in response to the oxygen tension in culture. Northern blot analysis demonstrated that the expression of both xCT and 4F2hc was significantly enhanced by oxygen. The results suggest that oxygen regulates the activity of system xc- by modulating the expression of both xCT and 4F2hc mRNAs.

Hydroxyl radical scavenging by carnosine and Cu(II)-carnosine complexes: a pulse-radiolysis and spectroscopic study

PURPOSE

To obtain a wider insight into the general properties of carnosine and to provide support to its anti-oxidative role. This property is hypothesized to be linked to various mechanisms including free-radical scavenging and metal chelation (i.e. Cu(II)).

METHODS

Pulse-radiolysis experiments were performed by a 12 MeV electron linear accelerator (LINAC) on carnosine/copper(II) (2:1) and carnosine aqueous solutions at different pH. Raman spectra of solid samples were obtained by a Bruker IFS 66 spectrometer.

RESULTS

As well as for free carnosine, in the presence of copper ions the interaction of carnosine with *OH radicals involves the imidazole group of the molecule. The oxidation of copper (II)-carnosine system by *OH radicals is related to the pH-dependent structure of the copper(II)-carnosine complex. Raman spectra indicate that at alkaline pH the formation of a dimeric species containing two carnosine molecules complexed to two Cu2+ ions takes place. This structure can address the *OH attack more selectively than carnosine itself to different sites of the imidazole ring. The formation of at least two different *OH-radical adducts occurs and positions C(2) and C(5) of the imidazole ring are the preferential sites for the *OH attack, as the heterocyclic ring is mainly present as its N(1)-protonated tautomeric form.

CONCLUSION

These studies provide further evidence about the formation of carnosine-copper complexes and the predominance of a dimeric structure at slightly basic pH. The chelation of Cu(II) is not detrimental to the scavenging ability of carnosine. Raman spectra are helpful in identifying the structure of the copper(II)-carnosine complexes and in predicting the preferential sites for the *OH attack to the carnosine-copper system.

A porcine homolog of the major secretory protein of human epididymis, HE1, specifically binds cholesterol

A porcine homolog of the major secretory protein of human epididymis, HE1, was for the first time purified from the porcine cauda epididymal fluid. The HE1 homolog was secreted into the epididymal fluid as a 19-kDa glycoprotein, whose sugar moiety was gradually processed to form a 16-kDa protein during transit through the epididymis. The HE1 homolog mRNA was detected only in the caput and corpus epididymis among the porcine tissues examined. The purified HE1 homolog specifically bound cholesterol with high affinity (Kd=2. 3 microM). The binding stoichiometry was determined to be 0.94 mol/mol, suggesting that 1 mol of cholesterol binds to 1 mol of the protein. It was also found that the HE1 homolog is a major cholesterol-binding protein in the porcine epididymal fluid. The possibility that the HE1 homolog is involved in the regulation of the lipid composition of the sperm membranes during the maturation in epididymis is discussed.

Cloning and expression of a plasma membrane cystine/glutamate exchange transporter composed of two distinct proteins

Transport system xc- found in plasma membrane of cultured mammalian cells is an exchange agency for anionic amino acids with high specificity for anionic form of cystine and glutamate. We have isolated cDNA encoding the transporter for system xc- from mouse activated macrophages by expression in Xenopus oocytes. The expression of system xc- activity in oocytes required two cDNA transcripts, and the sequence analysis revealed that one is identical with the heavy chain of 4F2 cell surface antigen (4F2hc) and the other is a novel protein of 502 amino acids with 12 putative transmembrane domains. The latter protein, named xCT, showed a significant homology with those recently reported to mediate cationic or zwitterionic amino acid transport when co-expressed with 4F2hc. Thus xCT is a new member of a family of amino acid transporters that form heteromultimeric complex with 4F2hc, with a striking difference in substrate specificity. The expression of system xc- was highly regulated, and Northern blot analysis demonstrated that the expression of both 4F2hc and xCT was enhanced in macrophages stimulated by lipopolysaccharide or an electrophilic agent. However, the expression of xCT was more directly correlated with the system xc- activity.

A pulse radiolysis study of carnosine in aqueous solution

PURPOSE

To investigate the potential antioxidative role of carnosine (beta-alanyl-L-histidine) through its interaction with radiation induced radicals.

MATERIALS AND METHODS

Pulse radiolysis experiments were performed by a 12 MeV electron linear accelerator (LINAC) on carnosine aqueous solutions at different pHs. The Raman spectra of solid samples were obtained by a Bruker IFS 66 spectrometer.

RESULTS

The protonation state of the imidazole ring was observed to affect the site(s) of .OH attack on carnosine as well as the decay rates of the resulting adducts. Reasonably, a base catalysed water elimination from the adducts leading to a resonance-stabilized radical, which absorbs at lambda = 270 nm, takes place. Raman spectra in slightly alkaline medium have indicated that carnosine is mainly present as tautomer I and, of consequence, positions C(2) and C(4) of the imidazole ring are the preferential sites for .OH attack.

CONCLUSIONS

These studies have shown that carnosine is a good scavenger of .OH radicals giving rise to a quite stable intermediate which should be less reactive towards other biological components than .OH itself. Raman data have been helpful in predicting the preferential sites for the .OH attack.

Stage-specific expression of a mouse homologue of the porcine 135kDa alpha-D-mannosidase (MAN2B2) in type A spermatogonia

The cDNA encoding a mouse homologue of porcine epididymis-specific 135kDa alpha-D-mannosidase (MAN2B2, D28521) was cloned from the mouse testis cDNA library. It was found that 1018 amino acids were coded in its open reading frame, and 62% of the amino acid sequence was identical to that of porcine MAN2B2. In the adult mouse, testis contained higher amounts of mRNA encoding the MAN2B2 homologue than the epididymis, though porcine MAN2B2 was mainly expressed in the narrow region between the caput and corpus epididymis. mRNA of the mouse MAN2B2 homologue was localized exclusively in spermatogonia in the testis. It was specifically expressed in type A spermatogonia at stages IX-XI of spermatogenesis and was detected there until the cell developed into type B spermatogonia. We conclude that the expression of the MAN2B2 homologue can serve as a good marker for the late stages of type A spermatogonia and may have an important role to play in the early step of spermatogenesis in mice.

Molecular cloning and characterization of the epididymis-specific glutathione peroxidase-like protein secreted in the porcine epididymal fluid

The epididymis-specific glutathione peroxidase was purified from the porcine cauda epididymal fluid in order to analyze its enzymatic activity and roles in the epididymis. The purified protein was found to consist of four identical 23 kDa subunits. The complementary DNA encoding the 23 kDa subunit was cloned from the cDNA library of the porcine proximal caput epididymis, only where the 23 kDa subunit is expressed. Although the selenocysteine codon (TGA) is contained in the cDNA of the other cytosolic type of glutathione peroxidases, it is replaced by cysteine codon (TGT) in the 23 kDa subunit cDNA, similarly to the results previously obtained for cDNAs encoding the epididymis-specific form of the secreted glutathione peroxidases of mouse, rat and monkey. By the direct analysis of the selenium, the purified protein was proved to contain no selenium atom in the molecule. The activities of the purified epididymis-specific glutathione peroxidase toward hydrogen peroxide or organic hydroperoxides were by far lower than the activity of cytosolic selenium-dependent glutathione peroxidase (less than 0.1%). In addition, the concentration of glutathione in the porcine epididymal fluids was about 20 microM, which is much lower than the optimal concentration for the glutathione peroxidase activity of the purified protein. These results strongly suggest that this protein is enzymatically quiescent at least in the porcine epididymal fluid. An immunocytochemical study showed that this protein was found to bind to the acrosomal region of the epididymal sperm and to disappear during the acrosome reaction. Furthermore, this protein significantly retarded the acrosome reaction induced in vitro. The possibilities have been discussed that it protects sperm from the premature acrosome reaction and maintains sperm fertilizing ability in the epididymis.

Isolation and characterisation of an Aujeszky's disease virus naturally infecting a wild boar (Sus scrofa)

Isolation of Aujeszky's disease virus (ADV) from an injured, female wild boar (Sus scrofa), shot dead by hunters, in an area adjacent to the Abruzzo National Park is reported. The brain was submitted for attempted virus isolation following episodes of mortality in several dogs and cats fed with meat from the wild boar. Virus was isolated on first passage from the brain of the wild boar. The restriction fragment length polymorphism profile of the isolate was assessed as a type I. The role of stress in reactivating latent ADV in wild boars, the possibility of transmitting infection to endangered species such as bears (Ursus arctos), wolves (Canis lupus), wild cats (Felis silvestris) and lynx (Lynx lynx), present in the Abruzzo National Park and the possible role of wild boars as reservoirs for ADV is discussed.

Direct evidence for the elevated synthesis and secretion of procathepsin L in the distal caput epididymis of boar

The proteins which are secreted from the restricted part of the epididymis are suggested to sustain sperm maturation. In porcine species, as the potential abilities of sperm for movement and fertilization greatly increase in the corpus epididymis, the secretions in both the caput and corpus epididymis seem to be very important for the sperm maturation. In this study, we have directed our attention to the 40 kDa protein which is detected in the fluid of the distal caput epididymis of boar. It was purified from the porcine cauda epididymal fluid and its cDNA was cloned from the cDNA library of the distal caput epididymis. According to the deduced amino acid sequence, the 40 kDa protein has been identified as procathepsin L. Northern blot analysis showed that the procathepsin L mRNA was most abundant in the distal caput epididymis among the tissues as examined. Consistent with the distribution of the procathepsin L mRNA in the epididymis, the activity of procathepsin L was absent in the fluid of the proximal and mid caput epididymis and first appeared in the distal caput epididymal fluid, whose contents gradually decreased with the passage through the epididymis. These results first appeared in the first distal caput epididymis expresses very high levels of procathepsin L and unusually secretes it into the luminal fluid instead of targeting it to lysosomes. It has been also found that the mRNA of PDGF, which is known to enhance cathepsin L expression in the culture cells, is very high in the mid caput epididymis, which just precedes the site of procathepsin L secretion. This result indicates that PDGF directly regulates the locally restricted expression and secretion of procathepsin L in the epididymis, which is one of the possible mechanisms involved in the functional differentiation in the epididymis.

Cloning of complementary DNA encoding a 135-kilodalton protein secreted from porcine corpus epididymis and its identification as an epididymis-specific alpha-mannosidase

In the preceding study (Okamura et al., 1992; Biol Reprod 47:1040-1052) we suggested that a 135-kDa protein secreted by porcine epididymis is involved in the sperm maturation. In this work, we have isolated the cDNA clone coding the 135-kDa protein in an effort to investigate its structure and function. The 135-kDa protein was purified from porcine cauda epididymal fluid. Three oligonucleotide probes were synthesized according to the amino acid sequences of N-termini of the native protein and trypsin-digested peptides. A cDNA clone hybridizing with these three probes was isolated from the cDNA library derived from the porcine proximal corpus epididymis. It encodes a novel protein with 1,006 amino acid residues in an open reading frame. Its overall amino acid sequence was significantly homologous (25.7%) to the alpha-mannosidase precursor of Dictiostelium discoideum (P34098). The 135-kDa protein could digest both p-nitro-phenyl-alpha-D-mannoside and high mannose oligo saccharide (Man8-GlcNAc2), strongly suggesting that it is an alpha-mannosidase homologue. The expression of this protein was specific to porcine and was localized to the very narrow parts of epididymis: the border of the caput and corpus epididymis. This protein may serve as a good marker for the functional differentiation in porcine epididymis. A possible role of this protein in the species-specific sperm-egg interaction is discussed.

Recovery of human lymphocytes damaged with gamma-radiation or enzymatically produced oxygen radicals: different effects of poly(ADP-ribosyl)polymerase inhibitors

Quiescent human lymphocytes were damaged in two different ways, both producing toxic oxygen radicals: xanthine oxidase plus hypoxanthine (XOD/HYP), or gamma-rays. Under conditions where DNA synthesis was reduced to 10-20% of control, inhibitors of poly(ADP-ribosyl)polymerase (ADPRP, an enzyme that becomes activated in the presence of DNA strand breaks) allowed lymphocytes to recover completely when the damage was caused by XOD/HYP, but they did not affect DNA synthesis of irradiated cells. However, a protective effect of ADPRP inhibitors was observed with irradiated lymphocytes receiving doses greater than or equal to 50 Gy. Unscheduled DNA synthesis was Unscheduled DNA synthesis was significantly increased when lymphocytes were damaged by high radiation doses in the presence of ADPRP inhibitors. We suggest that ionizing radiation does not stimulate poly(ADP-ribose) synthesis in lymphocytes at doses that impair lymphocyte DNA synthesis by 80-90%, while ADPRP may be involved in the repair of DNA lesions occurring at higher radiation doses.

Role of thiols in radioprotection: radiation chemical aspects

Using the technique of pulse radiolysis, it has been demonstrated that thiyl radicals (RS.) derived from glutathione (GSH), cysteine (CYSH), penicillamine (PnSH) and 2-mercaptoethanol (ME) interact with oxygen at a high rate. The resulting transient absorption, with a maximum around 540-560 nm, is characteristic of the sulphur peroxyl radical (RSOO.). The yield and the kinetic of formation of RSOO. further support our previous suggestion that thiyl/O2 reaction is an equilibrium. The redox properties of RSOO. are discussed on the basis of the interaction with reductants. Studies on the radio-induced enzyme inactivation in the presence of thiols seem to suggest a damaging role for RSOO. radicals.

Interactions of thiyl free radicals with oxygen: a pulse radiolysis study

A pulse radiolysis study of glutathione in aqueous solution at pH 5.5 containing N2O/O2 mixtures at various ratios indicates that oxygen rapidly adds to the thiyl glutathione radical yielding a transient absorption, with a maximum at 540 nm, whose characteristics appear to be compatible with assignment to the GSOO. radical. The reaction (Formula: see text) appears to be an equilibrium whose kinetic constants have been estimated (kf = 2.0 X 10(9) dm3 mol-1, kb = 6.2 X 10(5) s-1). Evidence for electron transfer from ascorbate to the GSOO. radical has been obtained and the respective rate constant has been determined to be 1.75 +/- 0.15 X 10(8) dm3 mol-1 s-1.

Reactions of selenium dioxide free radicals with amino acids and enzymes

Pulse radiolysis of selenium dioxide in aqueous solution has shown the presence of three selenite radicals in acid-base equilibrium within well defined pH ranges: (formula; see text) The selenite radicals react selectively with amino acids, preferentially with the aromatic ones in the order tryptophan greater than tyrosine greater than histidine, independently of the acid-base structure of the radical. Kinetic and spectroscopic data on the reaction of selenite radicals with some proteins and parallel inactivation studies generally reflect knowledge on the amino acid residues mainly involved in the radical attack. The investigations at different pH values on the reactivity of selenite radicals with amino acids and proteins and on the transient spectra of the reaction products exhibit different behaviour for the various acid-base structures of the selenite radicals, reflecting the influence of particular ionizable groups in the reacting molecules and the structure modifications at the level of proteins.

Effect of hyperthermia and gamma-radiation on Escherichia coli K1060 D-lactate dehydrogenase

The response of E. coli K1060 D-lactate dehydrogenase (D-LDH), an enzyme located in the cytoplasmic membrane, was studied following 42.5 degrees C hyperthermia and/or gamma-irradiation. The inactivation of D-LDH following the above treatment was used as a tool to probe the role of membrane proteins in the radiation and/or heat sensitivity of cells. No correlation between loss of enzyme activity and cell killing was found, suggesting that D-LDH does not play an important role in hyperthermic cell survival. The results obtained in combined hyperthermia and gamma-irradiation treatments on loss of D-LDH activity and E. coli cell killing suggest that an interaction between heat and radiation occurs at the membrane structure level. Moreover, when cells were heated at 42.5 degrees C in the presence of 10 mM procaine-HCl, both cell killing and loss of D-LDH activity were enhanced. The involvement of membrane structure in the heat sensitivity of cells is strongly indicated by the latter observations. The opposite effect was observed when procaine was present during irradiation in oxic conditions, suggesting that procaine itself can also act as a scavenger towards OH-induced radicals.

Role of glutathione in affecting the radiosensitivity of molecular and cellular systems

It has previously been shown that radioinduced organic radicals can be repaired by hydrogen donation from glutathione (GSH) and this repair is in competition with oxygen (damage fixation). In this paper the influence of exogenous glutathione on the radiation response of the enzyme alcohol dehydrogenase (YADH), DNA in vitro, and E. coli B/r cells has been investigated. GSH is observed to protect YADH essentially by free radical scavenging mechanisms in both presence or absence of oxygen. The same mechanism seems operate in the radioprotection afforded by GSH to DNA in vitro. E. coli B/r cells are protected at higher extent by GSH than its oxidized form (GSSG); the possibility that GSH penetrate into bacterial cells more easily that GSSG can explain their different behaviour. None of the three systems studied has provided definitive support for the occurrence of the hydrogen donation reaction in the radioprotective mechanisms of GSH versus biomolecules and bacterial cells.