Search for exotic baryons in 800 GeV pp-->pXi+/-piX reactions.

We report the results of a high-statistics, sensitive search for narrow baryon resonances decaying to Xi-pi-, Xi-pi+, Xi+pi-, and Xi+pi+. The only resonances observed are the well known Xi0(1530) and Xi0(1530). No evidence is found for the states near 1862 MeV, previously reported by NA49 [Phys. Rev. Lett. 92, 042003 (2003)]. At the 95% confidence level, we find the upper limit for the production of a Gaussian enhancement with sigma=7.6 MeV in the Xi-pi- effective mass spectrum to be 0.3% of the number of observed Xi0(1530)-->Xi-pi+. We find similarly restrictive upper limits for an enhancement at 1862 MeV in the Xi-pi+, Xi+pi-, and Xi+pi+ mass spectra.

Efficacy of low level laser therapy in reducing postoperative pain after endodontic surgery-- a randomized double blind clinical study.

The aim of the study was to evaluate the effect of low level laser application on postoperative pain after endodontic surgery in a double blind, randomized clinical study. Fifty-two healthy adults undergoing endodontic surgery were included into the study. Subsequently to suturing, 26 patients had the operation site treated with an 809 nm-GaAlAs-laser (oralaser voxx, Oralia GmbH, Konstanz, Germany) at a power output of 50 mW and an irradiation time of 150 s. Laser treatment was simulated in further 26 patients. Patients were instructed to evaluate their postoperative pain on 7 days after surgery by means of a visual analogue scale (VAS). The results revealed that the pain level in the laser group was lower than in the placebo group throughout the 7 day follow-up period. The differences, however, were significant only on the first postoperative day (Mann-Whitney U-test, p<0.05). Low level laser therapy can be beneficial for the reduction of postoperative pain. Its clinical efficiency and applicability with regard to endodontic surgery, however require further investigation. This is in particular true for the optimal energy dosage and the number of laser treatments needed after surgery.

Caracterización citofluorométrica de dos anticuerpos monoclonales específicos de epítopos polimórficos de moléculas HLA de clase I: 30.13.38 (anti-A2, A68, A69) y 29.30.6 (Anti-Bw6) / Cytofluorometric characterisation of two monoclonal antibodies recognising polymorphic epitopes of HLA class I molecules: 30.13.38 (anti-A*02, A*68 and A*69) and 29.30.6 (anti-Bw6)

Hemos caracterizado mediante citometría de flujo los anticuerpos monoclonales frente a moléculas HLA de clase I 30.13.38 y 29.30.6. Nuestros datos previos sobre su reactividad, obtenidos mediante citotoxicidad dependiente de complemento, indicaban que estos anticuerpos eran específicos de HLA-A2+A28, y del epítopo Bw6 portado por algunas moléculas HLA-B, respectivamente. Los experimentos de citometría de flujo mostraron que 30.13.38 reacciona con todos los alelos A*02, A*68 y A*69 disponibles en nuestro laboratorio: A*0201, *0204, *0205, *0207, *0211, *6801, *6802, and *6901. De acuerdo con estos datos, el epítopo diana más probable de 30.13.38 es TTKH (142-145). Por otra parte, el anticuerpo 29.30.6 tiñó con alta intensidad todas las células que expresan alelos con la secuencia asociada a Bw6 ESLRNLRG (76-83). Además, 29.30.6 reconoció con menor afinidad las variantes de esa secuencia que aparecen en B*7301 (VGLRNLRG), B*4601 (VSLRNLRG) y múltiples alelos HLA-C. No obstante, la afinidad de la interacción con estas variantes está por debajo o cerca del umbral de sensibilidad de la tipificación serológica (AU)

Low-level 809 nm GaAlAs laser irradiation increases the proliferation rate of human laryngeal carcinoma cells in vitro.

The aim of the study was to investigate the effect of low-level 809 nm laser irradiation on the proliferation rate of human larynx carcinoma cells in vitro. Epithelial tumor cells were obtained from a laryngeal carcinoma and cultured under standard conditions. For laser treatment the cells were spread on 96-well tissue culture plates. Sixty-six cell cultures were irradiated with an 809 nm GaAlAs laser. Another 66 served as controls. Power output was 10 mW(cw) and the time of exposure 75-300 s per well, corresponding to an energy fluence of 1.96-7.84 J/cm2. Subsequent to laser treatment, the cultures were incubated for 72 h. The proliferation rate was determined by means of fluorescence activity of a redox indicator (Alamar Blue Assay) added to the cultures immediately after the respective treatment. The indicator is reduced by metabolic activity related to cellular growth. Proliferation was determined up to 72 h after laser application. The irradiated cells revealed a considerably higher proliferation activity. The differences were highly significant up to 72 h after irradiation (Mann-Whitney U test, p < 0.001). A cellular responsiveness of human laryngeal carcinoma cells to low-level laser irradiation is obvious. The cell line is therefore suitable for basic research investigations concerning the biological mechanisms of LLLT on cells.

Efficacy of NaOCl/H2O2 irrigation and GaAlAs laser in decontamination of root canals in vitro.

BACKGROUND AND OBJECTIVES: To investigate the bactericidal effect of an 809 nm semiconductor laser alone, and in combination with NaOCl/H(2)O(2) irrigation in root canals in vitro. STUDY DESIGN/MATERIALS AND METHODS: A total of 72 human single-rooted teeth extracted for periodontal reasons were included. The crowns were removed, the roots shortened to a length of 12 mm, and the canals enlarged up to an apical size of #50 file. The specimens were autoclaved and incubated with a suspension of Streptococcus sanguinis (ATCC 10556). Laser irradiation was performed on a PC-controlled XY translation stage. A 200 micron optic fiber was used. Twelve specimens were irradiated at a power output of 1.5, 3.0, and 4.5 W in the cw-mode. The total irradiation time was 60 seconds per canal. Twelve specimens were rinsed with NaOCl and H(2)O(2) only, 12 were rinsed and laser treated, and 12 served as untreated controls. After laser treatment, the specimens were sonicated and the bacterial growth was examined by counting colony forming units on blood agar plates. Temperature changes at the outer root surface during irradiation were registered by means of thermocouples. Treated and control specimens were investigated by means of scanning electron microscopy. RESULTS: Mean bacterial reductions of 0.35 log steps at a power output of 1.5 W, 1.44 at 3.0 W, and 2.84 at 4.5 W were calculated. Bacterial reduction by the NaOCl/H(2)O(2) solution alone was 1.48 and comparable to that achieved by irradiation at 3.0 W. With a log kill 2.85, the combination of rinsing and laser irradiation at 3.0 W resulted in a further significant bacterial reduction as compared to rinsing alone (P = 0.004). Irradiation did not result in excessive heat generation at the root surface. Carbonization of the root canal wall was observed in single teeth at 3.0 and 4.5 W and no controlled sealing of the dentinal tubules could be achieved in the root canal. CONCLUSIONS: The application of the diode laser might be an adjunct to conventional endodontic treatment when used in combination with a NaOCl/H(2)O(2) solution.

Effects of esradiol and progesterone on the proliferation of human gingival fibroblasts.

AIM: The aim of the in vitro study was to examine the effect of estradiol and progesterone on the proliferation rate of human gingival fibroblasts (HGF) derived from a healthy and a diabetic (type II) individual. METHODS: In the first experiment, cells in the logarithmic proliferative phase were incubated with estradiol or progesterone at concentrations of 10, 50, and 100 microg/ml for 72 h. Beside the hormones, a glucose solution at a concentration of 200 mg/dl was added to the cell cultures in the second experiment in order to mimic a diabetic situation. The proliferation rate of the cells was determined by means of fluorescence activity of a redox indicator (Alamar Blue(R) Assay) added to the cell culture. Proliferation, expressed in relative fluorescence units (RFU), was determined after 24, 48, and 72 h. RESULTS: Progesterone at concentrations of 50 and 100 microg/ml significantly (Mann-Whitney-U-Test, p<0.05) reduced cellular growth in both cultures. Estradiol did not have a significant effect on cellular growth. The effect of progesterone was slightly reduced by glucose when cells from the healthy individual were used and remained almost unchanged with the cells from the diabetic patient. CONCLUSIONS: The results of the present study may help to understand the role of the female sex-hormones in the development of gingival and periodontal diseases during pregnancy. Further research work, however, is needed to elucidate the cellular mechanisms leading to the effects observed.

Effect of diode laser irradiation on root surfaces in vitro.

OBJECTIVE: The objective of this study was to evaluate possible morphological alterations of root surfaces after GaAlAs-diode laser (809 nm) irradiation under standardized in vitro conditions. MATERIALS AND METHODS: Root specimens obtained from extracted periodontally diseased teeth were scaled and root planed with curettes followed by air-powder abrasive treatment prior to lasing. The variable parameters were power output (0.5-2.5 W) and exposure time (10-30 sec per specimen). Additionally, the effect of a saline solution and a human blood film on the root surface was investigated. The root segments were analyzed by means of a reflected light microscope. Photographs before and after irradiation were taken and evaluated. The scale of carbonization was quantified using a grid laid over the photographs. Specimens with distinct morphological changes were analyzed with a scanning electron microscope. RESULTS: Lasing dry specimens and specimens moistened with saline resulted in no detectable alterations, irrespective of irradiation time and power output applied. Depending on different settings, irradiation caused severe damages to the root surface when segments were covered by a thin blood film. Irradiation at a power output of 1 Watt and below had barely any negative effect on the root surface, whereas lasing at 1.5, 2.0, and 2.5 Watt resulted in partial or total carbonizations of the root samples. The angle of irradiation had a significant effect on the scale of the root surface damage (Mann-Whitney U test,p < 0.05). CONCLUSION: The diode laser may cause damage to periodontal hard tissues if irradiation parameters are not adequate.

Lambda(0) polarization in 800-GeV/cpp --> p(f)(Lambda0K+).

We report results from a study of Lambda(0) polarization in the exclusive reaction pp --> p(f)(Lambda0K+) at 800-GeV/c. We observe a dependence of the polarization on the Lambda0K+ invariant mass with large (+71%) positive polarization at small mass (1.63-GeV/c(2)) and large (-43%) negative polarization at large mass (2.75-GeV/c(2)). This observation confirms the result of the CERN ISR R608 experiment and extends the range over which the effect is observed. The strong dependence of the polarization on the Lambda0K+ invariant mass suggests that the origin of the polarization is closely related to the production dynamics of the diffractively produced Lambda0K+ system.

Effect of diode laser irradiation on the attachment rate of periodontal ligament cells: an in vitro study.

BACKGROUND: The present study is part of a basic research program investigating the cellular effects of an 810 nm GaAlAs-diode laser on human periodontal tissues. The aim of the investigation was to evaluate the effects of laser treatment of root surface specimens on the attachment of periodontal ligament (PDL) cells in vitro. METHODS: Root specimens were prepared from periodontally diseased teeth. PDL cells were obtained from human third molar ligaments. Cells were cultured under simple, standardized, and reproducible experimental conditions. One hundred fifty root specimens were scaled and root planed with curets followed by air-powder abrasive treatment; 75 were then lased and 75 served as controls. The irradiation time was 20 seconds at a power output of 1 W. The root segments were placed into culture dishes, covered with a solution of PDL cells, and incubated for 72 hours. The specimens were then washed with phosphate buffer to remove cells not attached to the surface, and the adherent cells were stained with methylene blue. Cells were counted using a reflected light microscope and the cell density per mm2 was calculated. RESULTS: The analysis of 150 specimens revealed no significant differences between the groups (P = 0.347, Wilcoxon test). The cell numbers, however, were slightly higher on laser specimens. The mean was 66 cells/mm2 in the laser group and 63.7 cells/mm2 in the control group. CONCLUSIONS: The application of the diode laser at the parameters used did not have a substantially positive effect on the new attachment of PDL cells on the tooth specimens. It remains to be investigated whether the difference detected is really clinically relevant.

Diffractively produced charm final states in 800-GeV/c pp collisions.

We report the first observation of diffractively produced open charm in 800-GeV/c pp collisions of the type pp-->pD*X. We measure cross sections of sigma(diff)(D*+) = (0.185+/-0.044+/-0.054) (mu)b and sigma(diff)(D(*-)) = (0.174+/-0.034+/-0.029) (mu)b. Our measurements are based on 4.3x10(9) events recorded by FNAL E690 in the fixed-target run of 1991. We compare our results with previous fixed-target charm experiments.

Effect of diode laser irradiation on the survival rate of gingival fibroblast cell cultures.

BACKGROUND AND OBJECTIVE: The present study is part of a basic research program investigating the cellular effects of the GaAlAs-diode laser with a wavelength of 810 nm on human periodontal tissues. The aim of the investigation was to evaluate the effects of the laser treatment on the survival rate of human gingival fibroblasts (HGF) in monolayer cell culture at different power settings and durations. STUDY DESIGN/MATERIALS AND METHODS: HGF were obtained from a human gingival connective tissue explant. Cells were cultured on 24-well tissue culture plates. One hundred and thirty multi well cell cultures were laser treated. The variable parameters were power output (0.5-2.5 W) and exposure time (60-240 seconds per well). The cultures were analyzed by means of trypan blue staining, and the cell numbers counted under a light microscope. Photographs before and after irradiation were taken and evaluated. RESULTS: Depending on different settings, the laser irradiation caused significant (P < 0.05, t-test) reductions of cell numbers. Exposure time was more relevant to this phenomenon than the power output. Linear regression analysis revealed no unambiguous correlation between power output and cell death, when exposure time was kept constant. CONCLUSIONS: When used for periodontal pocket decontamination, the laser beam may cause damage to collateral periodontal tissues, if the power setting and the duration of the treatment are not adequate. Further investigation, especially with regard to the effects on hard tissue and microorganisms, are needed to give a secure recommendation for irradiation parameters at pocket decontamination.

A new method for the radiological investigation of residual ridge resorption in the maxilla.

OBJECTIVES: To develop a new method for assessing residual ridge resorption in the edentulous maxilla. METHODS: Defined experimental and reference areas in the maxilla were drawn on transparent film laid over a panoramic radiograph and digitized. Bone areas were measured with an integrated planimetry program and expressed as a ratio R. The effect of positioning errors on reliability of the method was investigated on dry skulls. The correlation between the change in ratio and actual bone loss was examined by progressively reducing the height of an artificial residual ridge on one skull. RESULTS: The coefficient of variation for the absolute ratio in different head positions was < 0.05 and its correlation coefficient of the change in R and the degree of resorption was r2 > or = 98.3%, P = 0.0001. CONCLUSIONS: Comparison of the experimental area with the reference area on serial panoramic radiographs appears suitable for the assessment of residual resorption in the maxilla.

HLA-Cw*1602: a new susceptibility marker of Behçet's disease in southern Spain.

Genotyping of the HLA-C locus by PCR-SSP in Behçet's disease patients from southern Spain reveals a statistically significant association with Cw*1602 (OR 20.15, corrected p < 0.05). This is an uncommon allele absent from the healthy control group, which seems to confer higher relative risk than B51 in this study (OR 1.85). Stratified frequencies do not show statistically significant differences but suggest that the Cw*1602-B51 haplotype could be the main HLA marker of Behçet's disease in the analyzed population.

Complete coding regions of two novel HLA-B alleles detected by phototyping (PCR-SSP) in the British caucasoid population: B*5108 and B*5002.

Two previously reported PCR-SSP variants of the HLA-B locus, B51GAC and B45v, were investigated by RT-PCR cloning and nucleotide sequence analysis of their complete coding regions. They have been shown to correspond to the new alleles B*5108 and B*5002, both of which differ from the common B*5101 and B*5001 subtypes, respectively, by amino acid replacements at their alpha-2 domain alpha-helices. The primary structure of B*5002, intermediate between those of B*4501 and B*5001, raises further concern about the current classification of B*45 as a B12 rather than as a B*50 subtype.

The novel HLA-Cw*1802 allele is associated with B*5703 in the Bubi population from Equatorial Guinea.

The HLA-Cw*1801 specificity, a Cw7/Cw4 hybrid allele, has recently been described in association with B*8101 (formerly B"DT"). In this study, the new Cw*1802 variant, differing from Cw*1801 at exon 5, is found associated with B*5703 in Bubi individuals from Equatorial Guinea. Confirmatory complete coding regions of B*5703 and B*3910 are also reported.

The complete primary structure of Cw*1701 reveals a highly divergent HLA class I molecule.

Genotyping of the HLA-C locus by PCR-SSP has previously shown 100% association of B41 and B42 with a new allelic variant. Partial sequencing studies (exons 2-4) demonstrated that this PCR-SSP variant corresponded to the new allele Cw*1701. In this study we have characterized the whole coding region of Cw*1701 from a Bubi individual of Equatorial Guinea. Our results partially confirm the previously reported sequence and reveal that Cw*1701 has many new polymorphisms at several exons, including a 18-bp insertion in exon 5. Cw*1701 is thus a most unusual HLA-C molecule defining a third allelic lineage of this locus.

HLA class I and class II allele distribution in the Bubi population from the island of Bioko (Equatorial Guinea).

We determined the HLA frequency distribution in a sample of 100 Bubi individuals born on the island of Bioko (Equatorial Guinea). HLA-A, -B and -C typing was performed by serology and PCR-SSP. DRB1/3/4/5, DQB1 and DQA1 alleles were determined by PCR-SSOP. The HLA allele distribution of this population group resembles those found in other Bantu-speaking groups; however, the higher frequency of A30, A32, B44, DRB1*1301 in the Bubi with respect to other Bantu groups and the absence of DR4 deserve special mention. The cloning and sequencing of class I and II genes in this population allowed the description of five new allelic variants: B*4407, Cw*0706, Cw*1801, Cw*1802 and DQB1*0612 and five confirmatory sequences: B*3910, B*5703, B*8101, Cw*1203 and Cw*1701. The following new HLA-C,B haplotypes have been found in Bubi: Cw*08-B*57, Cw*18-B*57, Cw*0302-B*53, Cw*07-B*53 and Cw*1601-B*63. The most frequent seven-locus haplotype is: A*30-Cw*17-B*42-DRB1*1102-DRB3*0202-DQA1*05-DQB1 *0301. In terms of genetic distance, the Bubi are closer to other Bantu groups than to West African populations.

Molecular cloning of two new HLA-C alleles: Cw*1801 and Cw*0706.

Nucleotide sequence analysis of the HLA-C alleles of the GB92 cell line, heterozygous for B*8101 and B*4407, revealed the existence of two new allelic variants: Cw*1801 and Cw*0706. The former allele, initially detected as a PCR-SSP variant, displays a hybrid aspect, sharing sequence motifs with Cw*07 at exons 1 and 2, and with Cw*04 at distal exons. In serological assays, Cw*1801 is only recognized by some cross-reactive sera. Cw*0706 shows a primary structure closely related to previously known Cw7 alleles, but carries new sequence motifs at its 3'-end. Preliminary data indicate that Cw*1801 is associated to B*8101 and that Cw*0706, B*4407 could account for a part of the Cw7, B44 haplotypes observed in African populations.

Complete coding region of the new HLA-DQB1*0612 allele, obtained by RT-PCR.

A novel HLA-DQB1 allele was detected by oligotyping in the Bubi population of Equatorial Guinea. In order to characterize the new allelic variant, a RT-PCR method which permitted the cloning of its complete coding region was designed. With this method, we have determined the nucleotide sequence of the new DQB1*0612 allele, related to *0604 and *0609 but differing from them at polymorphic codon 70. A proposal for the improvement of the sequencing strategies of HLA class II alleles is made.

Haplotypic association of two new HLA class I alleles: Cw*15052 and B*0706: evolutionary relationships of HLA-Cw*15 alleles.

A novel HLA-Cw*15, B7 haplotype has been found in Caucasians. Molecular cloning studies demonstrate that this haplotype is constituted by the new alleles Cw*15052 and B*0706, which seem to be intermediate steps in the diversification of their respective allelic families. A pathway for the evolution of Cw*15 alleles is proposed.