Impact of post printing cleaning methods on geometry, transmission, roughness parameters, and flexural strength of 3D-printed zirconia.

OBJECTIVE: To analyze the impact of different post printing cleaning methods on geometry, transmission, roughness parameters, and flexural strength of additively manufactured zirconia. METHODS: Disc-shaped specimens (N = 100) were 3D-printed from 3 mol%-yttria-stabilized zirconia (material: LithaCon 3Y 210; printer: CeraFab 7500, Lithoz) and were cleaned with five different methods (n = 20): (A) 25 s of airbrushing with the dedicated cleaning solution (LithaSol 30®, Lithoz) and 1-week storage in a drying oven (40 °C); (B) 25 s airbrushing (LithaSol 30®) without drying oven; (C) 30 s ultrasonic bath (US) filled with Lithasol30®; (D) 300 s US filled with LithaSol 30®; (E) 30 s US filled with LithaSol 30® followed by 40 s of airbrushing (LithaSol 30®). After cleaning, the samples were sintered. Geometry, transmission, roughness (Ra, Rz), characteristic strengths (σ0), and Weibull moduli (m) were analyzed. Statistical analyses were performed using Kolmogorov-Smirnov-, t-, Kruskal-Wallis-, and Mann-Whitney-U-tests (α < 0.05). RESULTS: Short US (C) resulted in the thickest and widest samples. Highest transmission was found for US combined with airbrushing (E, p ≤ 0.004), followed by D and B (same range, p = 0.070). Roughness was lowest for US combined with airbrushing (E, p ≤ 0.039), followed by A and B (same range, p = 0.172). A (σ0 = 1030 MPa, m = 8.2), B (σ0 = 1165 MPa, m = 9.8), and E (σ0 = 1146 MPa, m = 8.3) were significantly stronger (p < 0.001) and substantially more reliable than C (σ0 = 480 MPa, m = 1.9) and D (σ0 = 486 MPa, m = 2.1). SIGNIFICANCE: For 3D-printed zirconia, cleaning strategy selection is important. Airbrushing (B) and short US combined with airbrushing (E) were most favorable regarding transmission, roughness, and strength. Ultrasonic cleaning alone was ineffective (short duration) or detrimental (long duration). Strategy E could be particularly promising for hollow or porous structures.

[Application of image-guided injection for cervical and lumbar syndromes]. / Anwendung Bildwandler-gestützter Injektionen bei Zervikal- und Lumbalsyndromen.

The X­ray image-guided injection methods are an important tool for the treatment of cervical and lumbar pain syndromes. For the application of these methods it is necessary to have a differentiated consideration of cervical and lumbar pain syndromes. This leads to a decoding of complaints to assignable pain generators, which enables a targeted injection method. Depending on the origin of pain, injections are placed at the nerve root or the joints. Thus, the vicious cycle of pain can be stopped. A correct technical procedure is of enormous importance. Particular attention must be paid to the pharmacological effects and special complications. A monitoring and precautionary measures are mandatory.

Ehrlichia ruminantium antigens and peptides induce cytotoxic T cell responses in vitro.

Since CD8+ T cells play an important role in resistance to infection with heartwater, effective vaccines against this disease will likely require identification of antigens that contain CD8+ T cell epitopes responsible for cytotoxic T lymphocyte (CTL) responses. With the use of the fluorescent antigen-transfected target cell (FATT)-CTL assay, IFN-γ ELISPOT and flow cytometry, peptides that induce CTL, proliferation of CD8 + T cells and IFN-γ production were identified as possible target antigens for vaccine development. Of particular relevance was the finding that different peptides from different antigens were able to elicit varied cytotoxic activities by immune peripheral blood mononuclear cells (PBMC) from heartwater immune tick-infected sheep. Several peptides derived from Erum0660, Erum2330, Erum2540, Erum2580 and Erum5000 induced CTL in immune sheep PBMC. Peptide Erum2540-6 was the only peptide that induced significant CTL, CD8+CD45RO+ and CD8+IFN-γ+ by PBMC from all three sheep, and Erum2540 and p2540-20 induced the highest % CTL response in all three outbred sheep. These results suggest that these epitopes may be of major importance in heartwater recombinant vaccine development.

[The application of different injection methods for cervical and lumbar syndromes]. / Anwendung unterschiedlicher Injektionstherapien bei Zervikal- und Lumbalsyndromen.

The differentiated consideration of cervical and lumbar pain syndromes leads to a decoding of complaints to assignable pain generators which enables a targeted injection method. Depending on the origin of pain injections are placed at the nerve root or the joints. Thus, the vicious cycle can be stopped. A correct technical procedure is of enormous importance. Because pharmacological effects and special complications are possible, monitoring and precautions are mandatory.

African horse sickness virus serotype 4 antigens, VP1-1, VP2-2, VP4, VP7 and NS3, induce cytotoxic T cell responses in vitro.

It was shown in a previous study that proliferating CD8+ T cells could be detected in immune horse peripheral blood mononuclear cells (PBMC) when stimulated with African horse sickness virus serotype 4 (AHSV4). In this study the cytotoxicity of CD8+ T cells were tested by using the fluorescent antigen-transfected target cells-cytotoxic T lymphocytes (FATT-CTL) assay, for both the virus and its individual proteins expressed in Escherichia coli. This CTL assay measures the killing of viral protein expressing cells. AHSV proteins were successfully expressed in E. coli using the pET102/D-TOPO expression vector and the effector cells were stimulated with these recombinant proteins or with live viable virulent AHSV4. The AHSV genes were amplified and cloned into the pIRES-hrGFP II (pGFPempty) vector and these plasmid vectors encoding antigen-green fluorescent protein (GFP) fusion proteins were used to nucleofect PBMC, the target cells. The elimination of antigen-GFP expressing cells by CTL was quantified by flowcytometry. VP1-1, VP2-2, VP4, VP7 and NS3, antigen-specific CD8+ T cells resulted in cell lysis suggesting that CTL may play a role in the immune response induced against the AHSV4 vaccine strain.

Immune gene expression profiling of PBMC isolated from horses vaccinated with attenuated African horsesickness virus serotype 4.

Development of African horsesickness (AHS) subunit vaccines will have to include a rational approach that uses knowledge of how the virus interacts with the host immune system. The global in vivo immune response induced by attenuated AHSV serotype 4 in horses was characterised using transcriptome sequencing. PBMC were collected with 24h intervals for four days after inoculation and four days after a second boost, 21 days later. Transcriptome data were normalised to the day 0 naïve transcriptome and up- or down-regulated immune genes identified using the CLC workbench. Peak expression was observed 24h after each inoculation. Innate immunity was up-regulated after both inoculations and was characterised by type-1 interferon activation via the RIG-1/MDA5 pathway and the up-regulation of complement cascade components. After the second boost an adaptive immune response could be identified that included the production of cytokines indicative of T helper (Th)1, Th2 and Th17 responses.

Long-term results of the Hohmann and Lapidus procedure for the correction of hallux valgus: a prospective, randomised trial with eight- to 11-year follow-up involving 101 feet.

As it remains unproven that hypermobility of the first tarsometatarsal joint (TMTJ-1) is a significant factor in hallux valgus deformity, the necessity for including arthrodesis of TMTJ-1 as part of a surgical correction of a hallux valgus is questionable. In order to evaluate the role of this arthrodesis on the long-term outcome of hallux valgus surgery, a prospective, blinded, randomised study with long-term follow-up was performed, comparing the Lapidus procedure (which includes such an arthrodesis) with a simple Hohmann distal closing wedge metatarsal osteotomy. The study cohort comprised 101 feet in 87 patients: 50 feet were treated with a Hohmann procedure and 51 with a Lapidus procedure. Hypermobility of TMTJ-1 was assessed pre-operatively by clinical examination. After a mean of 9.25 years (7.25 to 11.42), 91 feet in 77 patients were available for follow-up. There was no difference in clinical or radiological outcome between the two procedures. Also, there was no difference in outcome between the two procedures in the subgroup clinically assessed as hypermobile. This study does not support the theory that a hallux valgus deformity in a patient with a clinically assessed hypermobile TMTJ-1 joint requires fusion of the first tarso-metatarsal joint.

Identification of Ehrlichia ruminantium proteins that activate cellular immune responses using a reverse vaccinology strategy.

Ehrlichia ruminantium is an obligate intracellular bacterial pathogen which causes heartwater, a serious tick-borne disease of ruminants throughout sub-Saharan Africa. The development of promising recombinant vaccines has been reported previously, but none has been as effective as immunisation with live organisms. In this study we have used reverse vaccinology to identify proteins that elicit an in vitro cellular immune response similar to that induced by intact E. ruminantium. The experimental strategy involved four successive steps: (i) in silico selection of the most likely vaccine candidate genes from the annotated genome; (ii) cloning and expression of the selected genes; (iii) in vitro screening of the expressed proteins for their ability to induce interferon-gamma (IFN-γ) production in E. ruminantium-immune lymphocytes; and (iv) further examination of the cytokine response profiles of those lymphocytes which tested positive for IFN-γ induction. Based on their overall cytokine induction profiles the recombinant proteins were divided into four distinct groups. Eleven recombinant proteins induced a cytokine profile that was similar to the recall immune response induced by immune peripheral blood mononuclear cells (PBMC) stimulated with intact E. ruminantium. This response comprised the upregulation of cytokines associated with adaptive cellular immune responses as well as innate immunity. A successful vaccine may therefore need to contain a combination of recombinant proteins which induce both immune pathways to ensure protection against heartwater.

A heterologous prime/boost immunisation strategy protects against virulent E. ruminantium Welgevonden needle challenge but not against tick challenge.

Heterologous prime/boost immunisation strategies using the Ehrlichia ruminantium 1H12 pCMViUBs_ORFs [Pretorius A, Collins NE, Steyn HC, Van Strijp F, Van Kleef M, Allsopp BA. Protection against heartwater by DNA immunisation with four Ehrlichia ruminantium open reading frames. Vaccine 2007;25(12):2316-24] were investigated in this study. All the animals immunised twice with a recombinant (r) DNA cocktail of four 1H12 pCMViUBs_ORFs followed by a r1H12 protein and those immunised 3x with 1H12 plasmid rDNA showed 100% protection against a virulent E. ruminantium Welgevonden needle challenge. In addition, 90% of the sheep immunised twice with rDNA and boosted with r1H12 lumpy skin disease virus (LSDV) survived. Only the lymphocytes isolated from the r1H12 protein boost group showed specific proliferation and increased interferon (IFN)-gamma expression. In contrast, only 20% protection was obtained in animals immunised with the rDNA prime/r1H12 protein boost when subjected to natural tick challenge in the field. Thus this heterologous prime/boost immunisation strategy had not conferred any significant protection against a field challenge.

Influence of poly(L-lysine) on the structure of dipalmitoylphosphatidylglycerol/water dispersions studied by X-ray scattering.

The interaction between the negatively charged phospholipid DPPG and positively charged poly(L: -lysine) (PLL) of different lengths was studied by X-ray scattering in the SAXS and WAXS region. As a reference pure DPPG (Na salt) was investigated over a wide temperature range (-30 to 70 degrees C). The phase behavior of DPPG in aqueous and in buffer/salt dispersions showed a metastable subgel phase at low temperatures and a recrystallization upon heating before reaching the liquid-crystalline phase. The presence of additional salt stabilizes the bilayer structure and decreases the recrystallization temperature. Large changes in the SAXS region are not connected with changes in chain packing. In DPPG/PLL samples, the PLL is inserted between adjacent headgroup layers and liberates counterions which give rise to a freezing point depression. In the complex with DPPG PLL form an alpha-helical secondary structure at pH 7 and temperatures below the gel to liquid-crystalline phase transition. This prevents DPPG from recrystallization and strongly increases the stacking order. The lamellar repeat distance is decreased and fixed by the helix conformation of PLL in the gel phase. PLL with n = 14 is too short to form helices and is squeezed out reversibly from the interbilayer space upon cooling by freezing of trapped water. In dispersions with longer PLLs (n > 400) at -20 degrees C a 1D crystallization of PLL alpha-helices in the aqueous layer between the headgroups takes place. A structural model is presented for the lateral periodic complex, which is similar to the known cationic lipid/DNA complex.

A comparison of the visual and technical assessment of preparations made by dental students.

The preparation of acrylic teeth in a simulated clinical environment (phantom head) plays an essential role in pre-clinical dental education where evaluation is performed visually by instructors. The aim of this investigation was to verify the quality criteria of a tooth preparation for a metal-ceramic crown (tooth No. 21) with the help of digital measurement. Thirty-six acrylic teeth were prepared by students and one tooth was prepared ideally by a trained dentist: These were examined and compared. Five experienced instructors independently assessed the quality criteria with the use of a criterion list. Afterwards, the teeth were scanned with the 3D-laser scanner 'es1' (Etkon Company, Munich, Germany). The calculation of the correlation coefficient demonstrated a satisfactory correlation between visual and digital rating concerning convergence angle, shoulder width and occlusal reduction. Greater differences between experimental groups were observed with regards to other criteria on the applied criterion list. A directed calibration of the evaluators and a re-evaluation of some measurements would be necessary to gain more precise results.

The genome of the heartwater agent Ehrlichia ruminantium contains multiple tandem repeats of actively variable copy number.

Heartwater, a tick-borne disease of domestic and wild ruminants, is caused by the intracellular rickettsia Ehrlichia ruminantium (previously known as Cowdria ruminantium). It is a major constraint to livestock production throughout subSaharan Africa, and it threatens to invade the Americas, yet there is no immediate prospect of an effective vaccine. A shotgun genome sequencing project was undertaken in the expectation that access to the complete protein coding repertoire of the organism will facilitate the search for vaccine candidate genes. We report here the complete 1,516,355-bp sequence of the type strain, the stock derived from the South African Welgevonden isolate. Only 62% of the genome is predicted to be coding sequence, encoding 888 proteins and 41 stable RNA species. The most striking feature is the large number of tandemly repeated and duplicated sequences, some of continuously variable copy number, which contributes to the low proportion of coding sequence. These repeats have mediated numerous translocation and inversion events that have resulted in the duplication and truncation of some genes and have also given rise to new genes. There are 32 predicted pseudogenes, most of which are truncated fragments of genes associated with repeats. Rather then being the result of the reductive evolution seen in other intracellular bacteria, these pseudogenes appear to be the product of ongoing sequence duplication events.

Total hip arthroplasty with Boneloc cement: Unsatisfactory results in 163 hips after 9 to 11 years.

Boneloc bone cement was introduced in the Netherlands in 1992. Inferior short-term results were reported which led to the withdrawal of Boneloc from clinical use in 1995. However, little is known about the long-term outcome of hip arthroplasties with Boneloc. Between April 1992 and August 1994, Boneloc was used in 163 Mallory-Head primary total hip arthroplasties in 163 patients. Follow-up analysis was performed in 2003. To date, 27 hips (17%) have been revised for aseptic loosening of the femoral component. Median time to revision was 5.5 years. Survival analysis based on revision for aseptic loosening showed 77% cumulative survival at 11 years. With revision for aseptic loosening and/or definite radiological loosening according to Harris as endpoint, cumulative survival was 59% at 11 years. In 27 of 43 patients with definite radiological loosening, a cement fracture was seen at a median of 2.9 years. These results show failure of Boneloc cemented total hip arthroplasties occurring even during the later follow-up. Continuing periodic clinical and radiological examination is recommended. (Hip International 2004; 14: 229-32).

Spectrophotometric analysis of all-ceramic materials and their interaction with luting agents and different backgrounds.

In this study, two All-Ceramic (AC) materials--Empress 2 (EMP) (Ivoclar Vivadent AG, Schaan, Liechtenstein) and In-Ceram ALUMINA (ICA) (Vita Zahnfabrik, Bad Säckingen, Germany)--were analyzed, along with the effects of 3 luting agents-viz. Zinc Phosphate cement (ZNPO, PhospaCEM PL, Ivoclar Vivadent AG, Schaan, Liechtenstein), Glass Ionomer Cement (GIC, Ketac-Cem Radiopaque, ESPE Dental AG, Seefeld, Germany), and Compolute (COMP, ESPE Dental AG, Seefeld, Germany)--on the final color, using the CIELab system. Color differences (DeltaL, Deltaa, Deltab, and DeltaE) were calculated for samples with luting agents and for samples without luting agents with standard white and black backgrounds, with the use of a spectrophotometer, Luci 100 (Dr. Lange, Berlin, Germany). One-way ANOVA for DeltaL, Deltaa, Deltab, and DeltaE within both the AC systems, with and without luting agents, showed significant contributions of the background (p < 0.05). EMP was seen to be more translucent than ICA. Darker ceramics showed less color variation. Luting agents altered the final color of the restoration. ZNPO was least translucent, followed by GIC and COMP. Marginal increases in thicknesses of ICA samples (0.4 mm) do not show a statistically significant color difference. No method exists to predict the outcome of an AC restoration based on consideration of the luting agent and the background color.

Lactobacillus diolivorans sp. nov., a 1,2-propanediol-degrading bacterium isolated from aerobically stable maize silage.

Inoculation of maize silage with Lactobacillus buchneri (5 x 10(5) c.f.u. g(-1) of maize silage) prior to ensiling results in the formation of aerobically stable silage. After 9 months, lactic acid bacterium counts are approximately 10(10) c.f.u. g(-1) in these treated silages. An important subpopulation (5.9 x 10(7) c.f.u. g(-1)) is able to degrade 1,2-propanediol, a fermentation product of L. buchneri, under anoxic conditions to 1-propanol and propionic acid. From this group of 1,2-propanediol-fermenting, facultatively anaerobic, heterofermentative lactobacilli, two rod-shaped isolates were purified and characterized. Comparative 16S rDNA sequence analysis revealed that the newly isolated bacteria have identical 16S rDNA sequences and belong phylogenetically to the L. buchneri group. DNA-DNA hybridizations, whole-cell protein fingerprinting and examination of phenotypic properties indicated that these two isolates represent a novel species, for which the name Lactobacillus diolivorans sp. nov. is proposed. The type strain is LMG 19667T (= DSM 14421T).

Quantification of first tarsometatarsal joint stiffness in hallux valgus patients.

OBJECTIVE: Comparison of the clinical mobility test of the first tarsometatarsal joint with Doppler Imaging of Vibrations measurement of the stiffness of this joint in hallux valgus patients. DESIGN: Clinical testing of first tarsometatarsal joint mobility was related to independent Doppler Imaging of Vibrations measurement of first tarsometatarsal joint stiffness. BACKGROUND: Hypermobility of the first tarsometatarsal joint has consequences for the surgical treatment of hallux valgus deformity. However, the clinical test is subjective. Doppler Imaging of Vibrations could be helpful in quantification of the stiffness of this joint. METHODS: Clinical examination of the mobility of 32 first tarsometatarsal joints in 20 hallux valgus patients was compared with Doppler Imaging of Vibrations stiffness measurements performed by an independent observer. RESULTS: There was a statistically significant relation between the clinical test and the stiffness measurement by Doppler Imaging of Vibrations. CONCLUSION: Doppler Imaging of Vibrations proves to be a method to quantify first tarsometatarsal joint stiffness and could contribute to a rational policy for the surgical treatment of hallux valgus deformity. RELEVANCE: The clinical test to establish hypermobility of the first tarsometatarsal joint is subjective. Doppler Imaging of Vibrations offers objective criteria and quantification of first tarsometatarsal joint stiffness. This provides additional information for the choice of the surgical procedure to correct hallux valgus deformity.

Anaerobic conversion of lactic acid to acetic acid and 1, 2-propanediol by Lactobacillus buchneri.

The degradation of lactic acid under anoxic conditions was studied in several strains of Lactobacillus buchneri and in close relatives such as Lactobacillus parabuchneri, Lactobacillus kefir, and Lactobacillus hilgardii. Of these lactobacilli, L. buchneri and L. parabuchneri were able to degrade lactic acid under anoxic conditions, without requiring an external electron acceptor. Each mole of lactic acid was converted into approximately 0.5 mol of acetic acid, 0.5 mol of 1,2-propanediol, and traces of ethanol. Based on stoichiometry studies and the high levels of NAD-linked 1, 2-propanediol-dependent oxidoreductase (530 to 790 nmol min(-1) mg of protein(-1)), a novel pathway for anaerobic lactic acid degradation is proposed. The anaerobic degradation of lactic acid by L. buchneri does not support cell growth and is pH dependent. Acidic conditions are needed to induce the lactic-acid-degrading capacity of the cells and to maintain the lactic-acid-degrading activity. At a pH above 5.8 hardly any lactic acid degradation was observed. The exact function of anaerobic lactic acid degradation by L. buchneri is not certain, but some results indicate that it plays a role in maintaining cell viability.

The presence of Acetobacter sp. in ensiled forage crops and ensiled industrial byproducts.

The presence of acetic acid bacteria (AAB) in whole crop maize silage, whole crop wheat silage, pressed sugar beet pulp silage, grass silage and brewer's grains silage was investigated. AAB could be isolated from whole crop maize silage, whole crop wheat silage and pressed sugar beet pulp silage, but could not be detected in grass silage (> 100 silo's tested) or brewer's grains silage (5 silo's tested). Thirty AAB isolates were characterized to genus level. All isolates, i.e. 20 from whole crop maize silage, 5 from whole crop wheat silage and 5 from pressed sugar beet pulp silage, belonged to the genus Acetobacter. Two isolates from maize silage were further characterized. Partial 16S rRNA analyses revealed that one isolate was closely related to Acetobacter aceti (98% sequence homology), the other to Acetobacter pomorum (98% sequence homology). These results combined with the substrate utilization profiles indicate that these isolates probably represent thus far undescribed species of Acetobacter.