Aesthetic correction of double tooth: simplified technique.

The aim of this study is to report aesthetic conservative treatment of double tooth anomaly. Case report: A 7.5-year-old patient presents an anomaly of the maxillary right upper central incisor with a bifid crown and an increased mesio-distal width and a central incisal notch, probably amenable to a gemination. Single tooth anesthesia and conservative enameloplasty procedure was performed, with universal adhesive and a single shade universal composite restorative material. Adhesive aesthetic restorations allow to resolve dental anomalies quickly, cheaply and asily for pediatric dentistry.

Effect of pressure and light curing of composite micro hardness.

The aim of this study is to evaluate the micro hardness Vickers of a composite micro hybrid polymerized under constant pressure. Twelve experimental samples were made equally divided into two groups: an experimental group and a control. Enamel plus HRi (Micerium) microbiotic composite resin, UD3 colour, was inserted into a syringe heater (ENA HEAT Composite Heating Conditioner) so that the material could be brought to a temperature of 39°C. A defined amount of composite resin is taken from the syringe with a Heidemann spatula and placed between two slides, previously cleaned with 90 ° alcohol. The samples are then inserted one at a time into a special device for constant pressure application. Vickers hardness measurements were made on the top of surfaces. The mean value of the samples belonging to the experimental group is 56.81 ± 0.71. The mean value of the control samples is 52.02 ± 2. The results obtained allow us to state that applying a constant pressure during the cementation phase of indirect adhesive restorations allows to obtain better mechanical characteristics of the composite used as a cementing agent.

Dentinal substrate variability and bonding effectiveness: SEM investigation.

Though the literature reports a well-documented scientific evidence of the performance of modern adhesive systems on normal dentin, few researches are available on the interaction between adhesives and compromised dentin. In this study, the authors analyzed the microscopic structural aspects of the adhesive interface on two common altered dentin substrates: dentin contaminated by metallic oxides and caries affected dentin. Thirty teeth were selected and divided in three groups of ten teeth according to the different dentin substrate they had: (A) normal dentin, (B) caries-affected dentin and (C) dentin contaminated by metallic oxides. The experimental cavity preparation was realised exposing in each sample, portion of pathologic dentin and portion of sound dentin as control. Each cavity was restored with micro-hybrid composite, with total etching and a two-step adhesive system. Each sample was sectioned in two halves analysed with two SEM micro-morphological methods: direct observation and decalcification. SEM investigations were able to show the difference in thickness and morphology of the adhesive interface with the two different dentin variables. Caries affected dentin determined the formation of less distinctive resin tags with few micro-tags. Discoloured dentin showed a poor infiltration with few resin tags probably due to alterations in the tubular structures. The micro-morphological variability of dentin substrate influences the clinical efficacy of bonding restorations determining significant differences in the qualitative and quantitative aspects of resin tags.

Indirect adhesive rehabilitation by cementation under pressure of a case of Dentinogenesis Imperfecta type II: follow-up after 13 years.

AIM: Dentinogenesis imperfecta (DI) is an autosomal dominant genetic disease that affects both deciduous and permanent teeth, with an incidence of 1 out of 6,000 to 1 out of 8,000. Teeth affected with DI type II present bulbous crowns, short and constricted roots, marked cervical constriction, translucent enamel and amber dentin. Also, they present a partial or total obliteration of pulp space, due to continuous dentin production. SEM analysis has shown an undulated dentin-enamel junction (DEJ) with irregularities and locally wide spaces between the two structures instead of a strict junction and a regular linear surface. Treatment options for patients affected by DI-II are intended to protect and restore function and aesthetics of both posterior and anterior teeth. In literature are presented many different therapies, but mainly centered on cemented prosthetic restorations instead of adhesive restorative procedures. We present in this paper a DI-II case successfully treated in 2005 with extensive adhesive rehabilitation. CONCLUSION: The 13 years follow-up proves the reliability of adhesion to dentine and enamel for indirect adhesive restorations even on this kind of anomalous substrates.

Pain and anxiety associated with Computer-Controlled Local Anaesthesia: systematic review and meta-analysis of cross-over studies.

AIM: This review focuses on Computer-Controlled Local Anaesthesia Delivery systems (CCLAD), in comparison with conventional carpule anaesthesia in means of pain and anxiety. METHODS: Medline, Embase, Web of Science and Cochrane Database for Systematic Reviews were searched up to August 2018. Only cross-over split-mouth design studies aimed to clinically compare CCLAD with a conventional carpule anaesthesia are included. Data about pain and anxiety associated with anaesthesia were sought. The authors performed meta-analysis where appropriate. RESULTS: A total of 20 studies are included in the systematic review (n = 973 subjects). Quantitative synthesis (conducted on VAS scores from 8 studies) shows that pain intensity is over 9 points lower in CCLAD than in conventional anaesthesia on a scale from 0 to 100 (95% confidence interval, ?12.90 to ?5,53; P<.001). The systematic review showed no differences between the two techniques according to the physiological parameters of pain (heart rate or blood pressure), and the data about anxiety are inconsistent. CONCLUSION: CCLAD results in significantly slightly less pain perception with respect to conventional injection and is a promising device to help patients. The literature needs to be expanded, mostly regarding anxiety.

Biological and physicochemical properties of biosurfactants produced by Lactobacillus jensenii P6A and Lactobacillus gasseri P65.

BACKGROUND: Lactobacillus species produce biosurfactants that can contribute to the bacteria's ability to prevent microbial infections associated with urogenital and gastrointestinal tracts and the skin. Here, we described the biological and physicochemical properties of biosurfactants produced by Lactobacillus jensenii P6A and Lactobacillus gasseri P65. RESULTS: The biosurfactants produced by L. jensenii P6A and L. gasseri P65 reduced the water surface tension from 72 to 43.2 mN m-1 and 42.5 mN m-1 as their concentration increased up to the critical micelle concentration (CMC) values of 7.1 and 8.58 mg mL-1, respectively. Maximum emulsifying activity was obtained at concentrations of 1 and 5 mg mL-1 for the P6A and P65 strains, respectively. The Fourier transform infrared spectroscopy data revealed that the biomolecules consist of a mixture of carbohydrates, lipids and proteins. The gas chromatography-mass spectrum analysis of L. jensenii P6A biosurfactant showed a major peak for 14-methypentadecanoic acid, which was the main fatty acid present in the biomolecule; conversely, eicosanoic acid dominated the biosurfactant produced by L. gasseri P65. Although both biosurfactants contain different percentages of the sugars galactose, glucose and ribose; rhamnose was only detected in the biomolecule produced by L. jensenii P6A. Emulsifying activities were stable after a 60-min incubation at 100 °C, at pH 2-10, and after the addition of potassium chloride and sodium bicarbonate, but not in the presence of sodium chloride. The biomolecules showed antimicrobial activity against clinical isolates of Escherichia coli and Candida albicans, with MIC values of 16 µg mL-1, and against Staphylococcus saprophyticus, Enterobacter aerogenes and Klebsiella pneumoniae at 128 µg mL-1. The biosurfactants also disrupted preformed biofilms of microorganisms at varying concentrations, being more efficient against E. aerogenes (64%) (P6A biosurfactant), and E. coli (46.4%) and S. saprophyticus (39%) (P65 biosurfactant). Both strains of lactobacilli could also co-aggregate pathogens. CONCLUSIONS: This report presents the first characterization of biosurfactants produced by L. jensenii P6A and L. gasseri P65. The antimicrobial properties and stability of these biomolecules indicate their potential use as alternative antimicrobial agents in the medical field for applications against pathogens that are responsible for infections in the gastrointestinal and urogenital tracts and the skin.

Effect of feeding fine maize particles on the reticular pH, milk yield and composition of dairy cows.

The particle size of cereal grains has been found to modulate the rate of passage from the rumen and the digestibility of starch and neutral detergent fibre (NDF), but few studies have examined its impact on reticular pH. The study aimed to evaluate the effect of feeding finely ground maize on the risk of ruminal acidosis, milk yield and composition. Twelve Holstein-Friesian cows were assigned to one of two experimental groups and fed according to a cross-over design. Diets were isoenergetic and isonitrogenous and were characterised by the same NDF and ADF, differing only in maize particle size. In the control diet (Ct), the maize meal was ground to 1.0 mm, whereas in the experimental diet, it was finely ground (Fg) to 0.5 mm. The pH and temperature of the reticulum were continuously measured in eight cows throughout the trial using indwelling sensors. Dry matter intake was higher in cows offered Fg diet than in Ct (19.0 vs. 20.3 kg/day; p = 0.067). However, milk yield (p = 0.855) and the 3.5% fat-corrected milk (FCM) (p = 0.724) did not show any differences between the diets. Casein (2.48 vs. 2.57%; p = 0.035) and crude protein (CP) (3.18 vs. 3.31%; p = 0.021) resulted higher in Fg. Similarly, starch digestibility increased in animals offered Fg diet versus Ct (0.94 vs. 0.98; p = 0.078). Among the reticular parameters, the Fg-fed cows spent a significantly higher time below the 5.5 pH threshold (15 vs. 61 min/day; p = 0.047) and had an average daily variation in reticular pH characterised by a lower nadir pH (5.95 vs. 5.72; p < 0.001) and a higher pH range (0.79 vs. 0.94; p = 0.003). In this study, grain particle size affected the risk of the onset of ruminal acidosis. Therefore, it should be carefully considered when formulating rations.

Association between hepatitis B or hepatitis C virus infection and risk of pancreatic adenocarcinoma development: a systematic review and meta-analysis.

BACKGROUND: Pancreatic adenocarcinoma (PAC) is an aggressive cancer with a poor prognosis. To date, PAC causes are still largely unknown. Antigens and replicative sequences of oncogenic hepatitis B (HBV) and hepatitis C (HCV) virus were detected in different extra-hepatic tissues, including pancreas. OBJECTIVE: a systematic review and meta-analysis of epidemiological studies assessing PAC risk in patients with HBV/HCV chronic infections. METHODS: In September 2012, we extracted the articles published in Medline, Embase and the Cochrane Library, using the following search terms: "chronic HBV" and "HCV", "hepatitis", "PAC", "risk factors", "epidemiology". Only case/control (C/C), prospective/retrospective cohort studies (PCS/RCS) written in English were collected. RESULTS: four hospital-based C/C studies and one PCS, in HBV-infected patients and two hospital-based C/C studies and one RCS in HCV-infected subjects met inclusion criteria. In these studies HBsAg positivity enhanced significantly PAC risk (RR = 1.18, 95% CI:1.04-1.33), whereas HBeAg positivity (RR = 1.31, 95% CI:0.85-2.02) as well as HBsAg negative/HBcAb positive/HBsAb positive pattern (RR = 1.12, 95% CI:0.78-1.59) and HBsAg negative/HBcAb positive/HBsAb negative pattern (RR = 1.30, 95% CI:0.93-1.84) did not. Relationship between PAC risk and anti-HCV positivity was not significant, although it reached a borderline value (RR = 1.160, 95% CI:0.99-1.3). CONCLUSIONS: HBV/HCV infection may represent a risk factor for PAC, but the small number of available researches, involving mainly populations of Asian ethnicity and the substantial variation between different geographical areas in seroprevalence of HBV/HCV-antigens/antibodies and genotypes are limiting factors to present meta-analysis.

Antigenic and genetic analyses of isolate APMV/wigeon/Italy/3920-1/2005 indicate that it represents a new avian paramyxovirus (APMV-12).

Isolate wigeon/Italy/3920-1/2005 (3920-1) was obtained during surveillance of wild birds in November 2005 in the Rovigo province of Northern Italy and shown to be a paramyxovirus. Analysis of cross-haemagglutination-inhibition tests between 3920-1 and representative avian paramyxoviruses showed only a low-level relationship to APMV-1. Phylogenetic analysis of the whole genome and each of the six genes indicated that while 3920-1 grouped with APMV-1 and APMV-9 viruses, it was quite distinct from these two. In the whole-genome analysis, 3920-1 had 52.1 % nucleotide sequence identity to the closest APMV-1 virus, 50.1 % identity to the APMV-9 genome, and less than 42 % identity to representatives of the other avian paramyxovirus groups. We propose isolate wigeon/Italy/3920-1/2005 as the prototype strain of a further APMV group, APMV-12.

Molecular identification of Lactobacillus spp. associated with puba, a Brazilian fermented cassava food.

Puba or carimã is a Brazilian staple food obtained by spontaneous submerged fermentation of cassava roots. A total of 116 lactobacilli and three cocci isolates from 20 commercial puba samples were recovered on de Man, Rogosa and Sharpe agar (MRS); they were characterized for their antagonistic activity against foodborne pathogens and identified taxonomically by classical and molecular methods. In all samples, lactic acid bacteria were recovered as the dominant microbiota (7.86 ± 0.41 log10 CFU/g). 16S-23S rRNA ARDRA pattern assigned 116 isolates to the Lactobacillus genus, represented by the species Lactobacillus fermentum (59 isolates), Lactobacillus delbrueckii (18 isolates), Lactobacillus casei (9 isolates), Lactobacillus reuteri (6 isolates), Lactobacillus brevis (3 isolates), Lactobacillus gasseri (2 isolates), Lactobacillus nagelii (1 isolate), and Lactobacillus plantarum group (18 isolates). recA gene-multiplex PCR analysis revealed that L. plantarum group isolates belonged to Lactobacillus plantarum (15 isolates) and Lactobacillus paraplantarum (3 isolates). Genomic diversity was investigated by molecular typing with rep (repetitive sequence)-based PCR using the primer ERIC2 (enterobacterial repetitive intergenic consensus). The Lactobacillus isolates exhibited genetic heterogeneity and species-specific fingerprint patterns. All the isolates showed antagonistic activity against the foodborne pathogenic bacteria tested. This antibacterial effect was attributed to acid production, except in the cases of three isolates that apparently produced bacteriocin-like inhibitory substances. This study provides the first insight into the genetic diversity of Lactobacillus spp. of puba.

Resistance of turkeys to experimental infection with an early 2009 Italian human influenza A(H1N1)v virus isolate.

We performed an experimental infection of 21- and 70-day-old meat turkeys with an early human isolate of the 2009 pandemic H1N1 influenza virus exhibiting an alpha-2,3 receptor binding profile. Virus was not recovered by molecular or conventional methods from blood, tracheal and cloacal swabs, lungs, intestine or muscle tissue. Seroconversion was detected in a limited number of birds with the homologous antigen only. Our findings suggest that in its present form, the pandemic H1N1 influenza virus is not likely to be transmitted to meat turkeys and does therefore not represent an animal health or food safety issue for this species.

Clinical antibacterial effectiveness Healozone Technology after incomplete caries removal.

AIM: Aim of this study was to evaluate the local effects of ozone gas on bacteria present within deep carious lesions after selective caries excavation. MATERIALS AND METHODS: The present study included 75 patients who had at least two Class I caries with deep lesion D2 and/or D3. The cavities were divided into 2 groups: the ozone group received treatment with Healozone X4, while the control group did not receive any treatment. Dentin samples were taken from both groups using two sterile multi-blade drills at 800 rpm without irrigation. The drills were then stored in separate tubes, each containing 5ml of RTF (Reduced Transport Fluid) and placed in culture for the next two hours. A total microbial count of the CFU of Streptococcus Mutans and Lactobacillus was performed. CONCLUSIONS: From the analysis of data on the dentin samples treated with ozone, there is a decrease in the bacterial load present in the infected carious dentin.

Conventional H5N9 vaccine suppresses shedding in specific-pathogen-free birds challenged with HPAI H5N1 A/chicken/Yamaguchi/7/2004.

Avian influenza represents one of the greatest concerns for public health that has emerged in recent times. Highly pathogenic avian influenza viruses belonging to the H5N1 subtype are endemic in Asia and are spreading in Europe and Africa. Vaccination is now considered a tool to support eradication efforts, provided it is appropriately managed. This study was carried out to establish the degree of clinical protection and reduction of viral shedding induced by a high-specification, commercially available avian influenza vaccine of a different lineage and containing a strain with a heterologous neuraminidase (H5N9 subtype) to the challenge virus isolate A/chicken/Yamaguchi/7/2004 (H5N1 subtype).

Comprehensive complexity assessment as a key tool for the prediction of in-hospital mortality in heart failure of aged patients admitted to internal medicine wards.

Congestive heart failure (CHF) and cognitive impairment are both common problems in old age, associated with significant mortality, impaired quality of life and disability. This study evaluated patients with CHF, admitted to internal medicine and geriatric wards. We identified factors associated with a high risk of in-hospital mortality. Hospitalized CHF subjects with increased risk of in-hospital death present a clinical profile including: very old age, overt cognitive dysfunction, predisposition to falls, dependency, social-family problems, impairment in sphincter control and feeding ability, presence of bedsores, digoxin but not warfarin treatment, hypo-dysproteinemia and hypernatremia and mild renal impairment. We observed that patients admitted to our Internal Medicine Departments, in addition to CHF, present a high grade of complex therapeutic needs and that comorbidity, by itself, does not reflect complexity. Our data support the hypothesis that CHF has different patterns of severity and prognosis in young and in old or very old age groups.

Multiple antimicrobial resistance in Enterobacteriaceae isolates from pristine freshwater.

A freshwater enterobacterial population (N = 111) was studied for antimicrobial and mercury resistance patterns, and for its possible association with biotic and abiotic factors in that environment. Conventional biochemical tests identified Klebsiella sp, Morganella sp, Serratia sp, Escherichia sp, Enterobacter sp, Edwarsiella sp, Proteus sp, Citrobacter sp, Providencia sp, and Kluyvera sp. There was no correlation between antimicrobial resistance patterns of isolates and bacterial genera, but resistance patterns varied among water samples and between seasons. Resistance to multiple antimicrobials was common (61%). The percentage of bacteria resistant to at least one antimicrobial differed between the rainy (100%) and dry seasons (89%). Resistance to beta-lactams and chloramphenicol was the most frequent and resistance to amikacin, gentamicin and kanamycin was less frequent. The main water variables examined (abiotic factors pH and temperature; biotic factor chlorophyll a concentration) did not influence antimicrobial resistance. Significant impact on freshwater enterobacteria, as evidenced by antimicrobial-multiple resistance and by the presence of bla(TEM) gene, may point to the fact that it has an important role in horizontal spread of resistance.

In vitro evaluation of the post-space depth reading with an intraoral scanner (IOS) compared to a traditional silicon impression.

OBJECTIVES: The aim of the study was to assess the depth and quality of the post-space reading, using an IOS without scan-post, compared to a traditional silicon technique. METHODS: Six extracted bicuspids were decoronated and endodontically treated. After having prepared the space for the posts, a structure in pink acrylic resin was created with two resin elements. At the center of the structure one sample was put at a time. Digital and traditional impressions were taken for each sample.Digital impressions were developed through the Computer-aided design (CAD) software in order to integrate the scanner results into a three-dimensional grid to make the measurements. A K-file was used to measure the length of the post-space of each sample obtained through the traditional silicon impression and subsequently the measurement results were reported on a millimeter gauge. Furthermore, an assessment of the width of the entrances of the post-spaces was carried out. RESULTS: The mean reading depth discrepancy expressed in percentages (19.58%) indicates that the digital impression with current technologies fails to impress clearly the post-space. Standard deviation of the data expressed in percentage is 13.89, suggesting that the values were not similar to each other. In two cases the digital technique has achieved less than 10% difference compared to the traditional technique, but there have been also cases in which the variation in depth has reached almost 40%.The samples that showed the minor discrepancy between the two techniques expressed the widest post-space entrance. CONCLUSIONS: In this in vitro study, the application of the IOS for the post-space reading in order to deliver an anatomic post has been proven to be still not reliable, as there are still depth reading limitations for the narrow root channels. In fact, in this type of channels it is difficult to reach with the light beam of the IOS the deepest areas of the post-space, with a consequent incomplete post-space reading.

Analysis of the antigenic profile of uveal melanoma lesions with anti-cutaneous melanoma-associated antigen and anti-HLA monoclonal antibodies.

The reactivity of 12 surgically removed uveal melanoma lesions with monoclonal antibodies (MoAb) to 14 membrane-bound and 2 cytoplasmic cutaneous melanoma-associated antigens (MAA), to the 2 subunits of HLA Class I antigens and to the gene products of the HLA-D region was compared with that of cutaneous melanoma lesions and correlated with their histiotype. The membrane-bound determinants defined by the anti-Mr 92,000 and 45,000 MAA MoAb TP39.1, anti-Mr 110,000 MAA MoAb M111, anti-Mr 118,000 MAA MoAb TP36.1, anti-Mr 115,000 MAA MoAb 345.134, anti-ICAM-1 MoAb CL203.4 and anti-Mr 31,000 MAA MoAb M2590, and the cytoplasmic determinants defined by the anti-MAA MoAb 465.12 and 2G-10 display a distribution in uveal melanoma lesions similar to that in cutaneous melanoma lesions. On the other hand, membrane-bound determinants defined by the anti-Mr 100,000 MAA MoAb 376.96, anti-9-O-acetyl-GD3 ganglioside MoAb ME311 and anti-GD2-GD3 ganglioside MoAb ME361 were not detected in the uveal melanoma lesions tested. Furthermore, the membrane-bound determinants defined by the anti-GD3 MoAb R24, anti-nerve growth factor receptor MoAb ME20.4, anti-Mr 97,000 MAA MoAb 140.240, anti-carcinoembryonic antigen MoAb B1.1 and anti-HMW-MAA 149.53, 225.28, and 763.74 have a markedly lower expression in uveal than in cutaneous melanoma lesions. Incubation of uveal melanoma lesions with the pool of the MoAb 149.53, 225.28, and 763.74 recognizing distinct and spatially distant determinants of the HMW-MAA increased the intensity of staining of six lesions and stained four lesions which were not stained by the individual monoclonal antibodies. The distribution of HLA Class I antigens in uveal melanoma lesions resembles that in cutaneous melanoma lesions, since they are expressed in all the lesions of the mixed and epithelioid type but were not detected in those of the spindle type, i.e., the counterparts of nevocellular nevi. HLA Class II antigens are expressed with a lower frequency in uveal than in cutaneous melanoma lesions, since they were detected only in 2 of the 12 lesions. One of them is of the mixed type and the other one of the epithelioid type. Besides HLA antigens the determinants defined by the anti-carcinoembryonic MoAb B1.1, anti-ICAM-1 MoAb CL203.4, and anti-GD3 MoAb R24 displayed a differential distribution in the different histiotypes of uveal melanoma, since they are preferentially expressed in lesions of the mixed and epithelioid type.

Ranitidine therapy for gastroesophageal reflux disease. Results of a large double-blind trial.

In a multicenter, double-blind trial, 284 patients with gastroesophageal reflux disease were evaluated before, during, and after six weeks of treatment with either placebo or ranitidine (150 mg twice daily). Randomization resulted in two comparable patient groups. Ranitidine treatment was significantly more effective than placebo treatment in decreasing the frequency and the severity of heartburn during both daytime and nighttime assessment periods. There was a significant correlation between improvement in heartburn symptoms and decrease in antacid consumption; hence, patients receiving ranitidine consumed significantly fewer antacid tablets. Among patients with endoscopic esophagitis at baseline, the overall change in endoscopic classification after six weeks of therapy was significantly better for the ranitidine-treated patients. The ranitidine-treated group had less evidence of erosions and ulcerations as well as greater healing. There were no differences between the groups with respect to changes in esophageal mucosal sensitivity to acid perfusion or changes in histologic grading of esophageal mucosal biopsy specimens. The ranitidine safety profile was similar to that of previous studies. We conclude that, in patients with gastroesophageal reflux disease, ranitidine therapy, 150 mg twice daily, markedly reduced the heartburn symptoms of reflux disease and significantly improved the endoscopic appearance of the esophageal mucosa.

Synthetic rubber surface as an alternative to concrete to improve welfare and performance of finishing beef cattle reared on fully slatted flooring.

The aim of this study was to compare a fully slatted concrete floor (concrete slatted (CS)) with the same floor on which synthetic rubber slats were placed on the concrete slats (rubber slatted (RS)) as housing solution for finishing beef cattle. The present study involved five commercial beef cattle farms in which the floor of at least three pens was kept as fully slatted, and in an equal number of pens a rubber cover was placed on the floor, tightly matching the gap profile of the concrete slats to allow the drainage of manure. A total of 326 finishing beef bulls were used (153 on CS and 173 on RS), and regardless of the floor treatment animals were housed in groups of 6 to 12 bulls/pen with a space allowance of 3.1 ± 0.2 m2/bull. Bulls had similar initial live weights (422.3 kg on CS and 425.0 kg on RS), but bulls on RS were heavier at the end of the finishing period with a higher average daily gain than bulls kept on CS (1.53 v. 1.46 kg/day; P<0.05). The proportion of bulls treated for locomotor problems was lower in RS pens compared with CS. Rubber covering prevented the occurrence of bursitis, but it increased the odds for hoof overgrowth at end of the finishing period. Hoof overgrowth detected in vivo in bulls on RS was confirmed at the slaughterhouse by the longer dorsal wall and diagonal lengths of the hoof as well as by a more acute toe angle. Compared with bulls on CS, bulls on RS showed less inactivity and resting time, increased social interactions, decreased abnormal lying down and unsuccessful attempts to lie down, as well as shortened the time for lying down. Bulls in RS pens were dirtier compared with those in CS pens, likely due to the draining gaps being reduced to 11.6 ± 1.2% of the total pen surface compared with the 16.9 ± 1.7% in CS pens. This study gave further evidence about the positive effects of the RS floor on growth performance and welfare of finishing beef cattle, although compromising cleanliness and hoof overgrowth.

Colonic delivery of dexamethasone: a pharmacoscintigraphic evaluation.

BACKGROUND: Colonic delivery of corticosteroids may reduce the side-effects commonly associated with their use. Therefore, we tested the ability of the naturally occurring polysaccharide guar gum to deliver a corticosteroid, dexamethasone, to the colon using pharmacoscintigraphy. Guar gum is metabolized in the colon by resident bacterial enzymes to trigger drug release. MATERIALS: Each subject (eight per group, parallel study design) was administered one of four dexamethasone (9 mg) tablet formulations, radiolabelled with 153Sm using neutron activation, under fasted conditions. One formulation was designed to release drug rapidly following ingestion while the other three formulations were designed to delay release of dexamethasone to varying degrees. Progression of the formulations down the gastrointestinal tract was followed by gamma scintigraphy. Serum concentrations were measured over time to relate disintegration profiles of the tablets with pharmacokinetic observations. RESULTS: The immediate release formulation disintegrated in the stomach, on average, within 20 min of dosing. One of the three delayed release preparations (CD1) began to disintegrate in the small intestine 1.7 +/- 1.0 h after dosing. The second and third delayed release preparations (CD2 and CD3) did not begin to disintegrate until 5.8 +/- 2.3 and 3.6 +/- 1.6 h after dosing, respectively. All three colonic delivery preparations completely disintegrated in the colon ranging from 7.8 +/- 2.7 h (CD1) to 12.4 +/- 3.2 h (CD2) following oral administration. Pharmacoscintigraphic data indicated that 72-82% of the dexamethasone was delivered into the colon although not all the dexamethasone delivered into the colon was absorbed. CONCLUSIONS: Simple guar gum formulations are capable of delivering the corticosteroid dexamethasone to the colon of normal subjects. Locally delivered corticosteroids may be useful in the treatment of ulcerative colitis and Crohn's disease. Pharmacoscintigraphic evaluation is a useful method to discriminate between the in vivo behaviour of colonic delivery systems.