Sterically driven synthesis of ruthenium and ruthenium-silver N-heterocyclic carbene complexes.

A straightforward and efficient synthetic route to novel Ru N-heterocyclic carbene (NHC) complexes by transmetallation of non-bulky silver NHC to ruthenium dicarbonyl tetraarylcyclopentadienone is described. The same procedure with sterically demanding NHC leads to unprecedented heterobimetallic Ru-Ag(NHC) complexes.

High hydrostatic pressure activity on the disinfection of clams artificially contaminated with feline calicivirus.

BACKGROUND: The contamination of shellfish with gastroenteric viruses may cause outbreaks because they are often eaten raw or under-cooked. High-hydrostatic pressure treatments have already proven to be effective in reducing high viral load in shellfish samples. The objectives are the assessment of the viral load reduction of contaminated clams using HHP treatments at different pressures and times and the study of the changes caused by these treatments in some food physical parameters. METHODS: Clams were contaminated with a solution containing Feline Calicivirus; they were closed in envelopes and treated with 300, 400, 500, 600 MPa for 1, 3, 5, 7 min for every pressure value. After the treatment the residual viral titre was calculated. The texture parameters were obtained after treating clams samples at the same pressure values but only for 3 and 7 min and analysing them with a TPA test. RESULTS: HHP treatments of 500 and 600 MPa were sufficient to cause a total inactivation at every timelength considered while with 300 and 400 MPa after 1 min, concentrations of 1.13 and 0.55 respectively were found. In general hardness and gumminess tend to increase after the treatment whereas springiness and cohesiveness decrease a bit. CONCLUSIONS: HHP treatments showed good sterilization ability against FCV but it's necessary to consider that FCV has a lower resistance to disinfection than Human norovirus. Texture changes are in line with what is reported in literature.

Detection of enteroviruses from urban sewage in Parma.

BACKGROUND AND AIM OF THE WORK: The human enteroviruses (EV) are the most common and widespread human viruses in the world. They have bowel as their natural habitat and they can spread in the environment through the faecal excretion. In the continental climate Regions these viruses may cause epidemic outbreaks in summer and fall, while in the tropical Regions the EV infections present a high incidence during all year. The symptoms can be minor or subclinic, but they can be also associated to rare and serious diseases. The aim of this study was to evaluate the environmental circulation of polioviruses and non-polio enteroviruses (NPEV) using standard methods of urban wastewater surveillance recommended by the WHO. METHODS: A total of 188 wastewater samples were collected between February 2005 and December 2008 from two sewage treatment plants in Parma. The sampling was carried out twice a month. Environmental variables were collected for each day of sampling. RESULTS: Out of the 188 examined wastewater samples, 78.7% were positive to the enterovirus research. One out of the 148 positive samples was identified as poliovirus Sabin-like type 3. The remaining 147 positive samples were enteroviruses non polio: Coxsakieviruses and Echoviruses. All Coxsakieviruses isolated were of type B. CONCLUSIONS: The proposed method has shown high sensibility, also in presence of very low expected prevalence of vaccine poliovirus. It allows to verify the kind and relative frequency of enteric viruses circulating in the country, whose characteristics (virulence and pathogenicity) may vary with reference to a different epidemiologic and demographic structure of the resident population.

Frequent association of multiple sclerosis with varicella and zoster.

BACKGROUND: A possible association of multiple sclerosis (MS) with viral diseases has been postulated; in previous studies we have found that in Mexican mestizos the antecedent of varicella during childhood represents a risk factor for the development of MS during adulthood. AIM: We conducted a retrospective search for varicella and zoster infections associated with the development of MS. METHODS AND RESULTS: In a cohort of 82 consecutive patients with MS we found six cases, four of varicella and two of zoster, that were concurrent with the development or the progress of MS. CONCLUSIONS: The association of these pathologies is higher than expected and suggests a possible etiological relationship of the varicella zoster virus with MS.

[The concentration of viruses in water using the tangential flow ultrafiltration. Recovery effectiveness in experimental conditions]. / Impiego dell'ultrafiltrazione a flusso tangenziale per la concentrazione dei virus nelle acque. Valutazione dell'efficacia di recupero virale in condizioni sperimentali.

Poliovirus 1 concentration tests were carried out in artificially contaminated water by tangential flow ultrafiltration with Polisulfone filters 100000 MWCO. The tests were performed in 1 and in 20 liters of waters. The filters were conditioned and eluted respectively with Beef extract 3% and with glicina 1% at pH 7 and pH 9. The recovery mean using Beef extract resulted properly good, about the 83% and comparable to percentages we obtained in previous works with filters in cellulose nitrate and Virosorb filters. The viral recovery was low using the glicina for conditioning and eluting the filters.

Laterally moved, coronally advanced flap: a modified surgical approach for isolated recession-type defects.

BACKGROUND: Various modifications of the laterally sliding flap have been proposed to reduce the risk of gingival recession at the donor tooth site, but the reported root coverage predictability was quite low. The goal of the present study was to evaluate the effectiveness with respect to root coverage of a modified surgical approach of the laterally moved flap procedure for the treatment of an isolated type of recession defect. METHODS: One hundred and twenty (120) isolated gingival recessions (Miller Class I or II) with specific features of the keratinized tissue lateral to the defects were treated with a new approach to the laterally moved flap. The main surgical modifications consisted of the coronal advancement of the laterally moved flap and the different thickness during flap elevation. Clinical evaluation was made 1 year after the surgery. RESULTS: At the 1-year examination, 97% of the root surface was covered with soft tissue and 96 defects (80%) showed complete root coverage. A statistical and clinically significant increase of keratinized tissue was observed. These favorable results were accomplished with no change in the position of gingival margin or in the height of gingival tissue at the donor tooth/site. CONCLUSIONS: The laterally moved, coronally advanced surgical technique was very effective in treating isolated gingival recessions. It combined the esthetic and root coverage advantages of the coronally advanced flap with the increase in gingival thickness and keratinized tissue associated with the laterally moved flap. The ideal gingival conditions must be present lateral to an isolated recession defect in order to render the proposed surgical technique an highly effective and predictable root coverage surgical procedure.

[Presence of disinfection by-products (DBPs) and other halogenated compounds in drinking water samples collected in the areas of Modena and Parma]. / Indagine sulla presenza di sottoprodotti della clorazione (Disinfection By-Products: DBPs) ed altri composti alogenati nelle acque potabili di Modena e Parma.

The Authors report data about the presence of Disinfection By-Products (DBPs) and other halogenated compounds in drinking water samples collected in the areas of Modena and Parma (20 water supplies). Trihalomethanes, chlorite and chlorate (only in water samples treated with chlorine dioxide), and halogenated compounds were investigated. On the whole, trihalomethanes were evidenced in the 85% of the samples (n. 285) at low levels, while chlorite and chlorate were present in the 67% and 63% of the treated samples with chlorine dioxide (257 samples). Chlorite mean and median values were 225.70 microg/l and 136.75 microg/l respectively, ranging from 20 to 2000 microg/l. Chlorate concentrations were lower than chlorite: the mean value was 102.93 mg/l, while median level was 50 microg/l (range: 20-1500 microg/l). The high concentrations of chlorite and the wide range of values within each municipality plant in Modena and Parma suggest to investigate further in order to evaluate the human exposure in drinking water thoroughly.

A histological and electron-microscopic study of the architecture and ultrastructure of human periodontal tissues.

The structure of periodontal tissues is still far less understood than their clinical relevance would demand. Here the periodontal ligament and radicular cementum in healthy human teeth were studied by light microscopy, transmission and scanning electron microscopy. These observations showed that the extracellular matrix of periodontal ligament is composed of a loose plexus of wavy collagen fibrils immersed in a highly hydrated interfibrillar matrix. Only close to their cemental insertion do these fibrils gather in thick, parallel fascicles (Sharpey's fibres). As these cross the mineralization front, they become infiltrated by the mineral phase and continue directly with the cementum matrix. Sharpey's fibres, "extrinsic" and "intrinsic" fibres all appear to be the same fibres, which bend and branch repeatedly during their course within the thickness of the cementum. Because of its physical continuity with the cementum, a limited portion of the periodontal ligament approximately corresponding to the length of Sharpey's fibres remains unaffected by enzymatic digestion of the interfibrillar matrix while the rest of the ligament is completely dissolved. The findings here indicate that the periodontal ligament and dental cementum join by a continuity rather than a contiguity of structures; that the collagen-mineral relation in cementum has distinctive features in comparison to other hard tissues; that extrinsic and intrinsic fibres of cementum and the adjoining portion of periodontal ligament form a structural, mechanical and metabolic unit distinct from the central, more metabolically active portion of the periodontal ligament.

Topical and systemic antimicrobial therapy in guided tissue regeneration.

BACKGROUND: Bacterial contamination of membrane material negatively affects healing after guided tissue regeneration (GTR) procedures; conversely, flap connective tissue integration on barrier material improves the clinical outcomes. The objective of this study was to evaluate the effect of topical application of antibiotics on: 1) clinical outcomes of GTR surgical procedures using titanium reinforced expanded polytetrafluoroethylene (ePTFE) periodontal membrane; 2) bacterial colonization of membrane material; and 3) flap connective tissue-membrane integration. METHODS: Fifty-six deep interproximal bony defects were treated with GTR surgical procedures using titanium reinforced ePTFE periodontal membranes. Patients were randomly assigned to 1 of the 2 antimicrobial treatment groups: the test group received weekly topical application of 25% metronidazole gel and the control group received systemic antibiotics (amoxicillin plus clavulanic acid 1 g/day for 14 days). Clinical outcomes were assessed at 1 year; the amount of bacterial contamination and connective tissue integration on membrane material was evaluated at time of membrane removal by means of a morphological (SEM) method. RESULTS: No statistically significant difference was found between test and control groups in terms of clinical attachment (CAL) gain (baseline CAL - 12 months CAL; P = 0.2) and probing depth (PD) reduction (baseline PD - 12 months PD; P = 0.6). A greater increase in gingival recession (REC) (12 months REC - baseline REC) was found in the test group compared to the control group (P = 0.003). The SEM analysis revealed no statistically significant (t test) difference between test and control groups in the number of fields positive to integrated connective tissue (P = 0.82), while the number of fields positive to bacteria was statistically higher (P < 0.001) in the control group. CONCLUSIONS: Local antibiotic administration is more effective than systemic use in preventing membrane contamination, but it does not improve clinical outcomes due to an interference of the vehicle (gel) with gingival tissues which may reduce the potential benefits derived from better control of the bacterial load.

Early bacterial accumulation on guided tissue regeneration membrane materials. An in vivo study.

The aim of the study was to compare the in vivo early bacterial plaque colonization of 3 different guided tissue regeneration (GTR) membrane materials using a morphological (scanning electron microscope) method. Rectangular-shaped strips were cut from 3 periodontal membranes (expanded polytetrafluoroethylene, polyglactin 910, and polylactic acid) and glued to the buccal aspect of removable acrylic devices, which were applied to the molar-premolar region of the upper quadrants in 8 dental students. Each device held 3 strips: one ePTFE, one polyglactin 910, and one polylactic acid. The surface roughness of each membrane material was measured by means of a laser profilometer. During a 24-hour period, the students had to refrain from any oral hygiene procedures and did not use chlorhexidine mouthrinses. In each subject, one device was removed after 4 hours and the other after 24 hours. After removal, the devices were placed in a 2.5% gluteraldehyde solution to fix the membranes, which were then processed for SEM analysis. Fifty-four microscopic fields (at 200x magnification) were randomly selected and analyzed in each strip. Magnification was increased to determine the presence of bacterial morphotypes. The presence or absence of bacteria was assessed in a binomial fashion. In such a system, the field was bacteria-positive when bacteria constituted the deposits covering the surface of the membrane. The microscopic field was considered bacteria-negative when no bacteria were present. Bacteria-positive fields showing rods and filaments as prevalent bacterial morphotypes were recorded as rod-positive fields. A different pattern of plaque accumulation was demonstrated on different membrane materials. The 4-hour results indicated a statistically significant difference (P = 0.008, ANOVA) in the proportion of bacteria-positive fields among the 3 membranes; a greater amount of bacteria was demonstrated on the ePTFE membrane compared to the other 2 membranes. At 24 hours, the difference in the proportion of bacteria-positive fields was statistically significant (P = 0.002, ANOVA); a lesser amount of bacterial plaque was present on the polylactic acid membrane compared to the ePTFE and polyglactin 910 membranes. No difference in the proportion of rod/bacteria-positive fields was demonstrated among the 3 membranes at either 4 or 24 hours. It was concluded that quantitative differences in early plaque accumulation on various membranes seem to be related to the textural and structural characteristics of the surface, which is not adequately represented by the surface Ra value measured with a profilometric instrument.

Cefoperazone plus piperacillin versus mezlocillin plus tobramycin as empiric therapy for febrile episodes in neutropenic patients.

The double beta-lactam combination of cefoperazone plus piperacillin was compared with an aminoglycoside-containing regimen of mezlocillin plus tobramycin in a prospective, randomized trial of empiric therapy for febrile neutropenic patients (neutrophils no more than 1,000/mm3). Thirty febrile episodes were treated with cefoperazone plus piperacillin and mezlocillin plus tobramycin, respectively. There was no significant difference between the two groups with respect to age, sex, pretherapy neutrophil count, and mean duration of therapy. The majority of patients had neutrophil counts of no more than 200/mm3 at the initiation of therapy. Only microbiologically and clinically documented infections were evaluated for efficacy. The cefoperazone plus piperacillin regimen appeared to have a comparable response rate with the mezlocillin plus tobramycin regimen (20 of 24 patients [83 percent] versus 16 of 23 patients [70 percent]). Gram-positive micro-organisms were seen predominantly in this study, with the cefoperazone plus piperacillin regimen achieving a bacteriologic response in 84 percent, as opposed to 60 percent for those organisms treated with the mezlocillin plus tobramycin regimen. Neither regimen was totally effective against coagulase-negative staphylococci. Eight superinfections occurred in the cefoperazone plus piperacillin arm, whereas 11 superinfections occurred in the mezlocillin plus tobramycin arm. Although fungal superinfections were most common, the number of gram-positive superinfections in the mezlocillin plus tobramycin arm exceeded those seen in the cefoperazone plus piperacillin arm. The incidence of antibiotic-related side effects was similar in the two groups. Hypokalemia was most frequently seen. Both skin rashes and nephrotoxicity were more common with mezlocillin plus tobramycin. Cefoperazone plus piperacillin was found to be effective empiric therapy in febrile neutropenic patients. This double beta-lactam combination may be particularly useful for patients who have or are at high risk for the development of renal insufficiency.

Breast contact thermography for differentiation between premature thelarche and true precocious puberty.

Breast contact thermography was used to differentiate between premature thelarche and true precocious puberty. The technique was applied to 10 girls with premature thelarche, 12 with precocious puberty and 105 controls (Tanner B1-5). In controls, the scores attributed to the maturative thermographic signs correlated with breast development stages. In premature thelarche thermographic signs of vascularization were always absent, while in precocious puberty they were always observed, although in some cases unilaterally. The thermographic index (higher total score between the two breasts) ranged from 0 to 3 in girls with premature thelarche and from 4 to 10 in girls with precocious puberty. The thermographic pattern in premature thelarche was similar to that in prepubertal girls and did not progress in two girls who were repeatedly examined. We emphasize the useful role of contact thermography in evaluating pubertal breast development and in differentiating between premature thelarche and true precocious puberty.