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Introduction: Arsenic is a traditional poison that has a history extending back to ancient times. Case presentation: A 43-year-old male presented to our Emergency Department 50 min after ingestion of 300 mL self-prepared arsenic trioxide solution (砒霜). He produced the solution from heating xionghuang (雄黃), an arsenic sulfide mineral (As4S4) which is a Chinese herb, for academic purposes a few years ago. Discussion: Supportive care including fluid replacement and decontamination with gastric lavage and chelation therapy with intravenous dimercaptopropanesulphonate sodium was given to patient. Spot urine arsenic to creatinine ratio significantly decreased from 343,124 nmol/mmol (day 3) to 7116 nmol/mmol (day 5). He had an uneventful course without any neurological deficit. Conclusions: Treatment of acute arsenic poisoning includes supportive care, decontamination, and chelation therapy. DMPS is an antidote for arsenic poisoning and its use should be directed by clinical status and urinary arsenic excretion. [ABSTRACT FROM AUTHOR]

The article discusses a study focusing on the prevalence of asthma-COPD overlap syndrome (ACOS) in patients newly diagnosed with adult-onset asthma. Topics discussed include the allergic diseases in patients; the prevalence of several respiratory diseases in the patients; and the Poisson regression models used in the study.

Q fever (QF) is a worldwide zoonosis associated with outbreaks. Only a few nationwide studies regarding the surveillance and epidemiology of human QF have been reported. Although QF is endemic in Taiwan, a nationwide database investigation of the epidemiology and characteristics of QF and its associations with scrub typhus (ST), murine typhus (MT) and leptospirosis (LS) has never been reported. We analysed nationwide databases of suspected QF, ST, MT and LS cases from October 2007 to December 2014 obtained from the Centers for Disease Control, Taiwan. A total of 468 (4.2%) QF cases were identified among 11 109 suspected QF cases. QF cases were mainly distributed in the southern and Kaohsiung-Pingtung regions but rarely in the eastern region. Compared to non-QF cases, QF cases had significantly higher percentages of males (88.7 versus 66.2%) and high-risk occupations (farming, animal husbandry or veterinary medicine) (16.2 versus 10.5%). But the percentages of specific animal contact, including cattle (0.6 versus 0.8%) and goats (0.9 versus 1.0%), were low in both. The majority of suspected QF cases (89.4%) were simultaneously suspected with ST, MT or LS, and the combinations of suspected diseases differed between regions. The number of suspected QF cases from the eastern region decreased since 2009, which was not observed in other regions. A total of 1420 (12.8%) cases had confirmed diseases, including QF (453, 4.1%), QF+ST (7, 0.06%), QF+MT (4, 0.04%), QF+LS (4, 0.04%), MT (186, 1.7%), ST (545, 4.9%), ST+LS (11, 0.1%) and LS (210, 1.9%). Compared to cases of unknown disease, QF cases had larger percentages of high-risk occupations (16.2 versus 9.6%) but similar histories of animal contact (29.8 versus 25.1%). QF is an endemic disease in southern Taiwan. It is difficult to differentiate QF from ST, MT or LS only by high-risk occupations and history of animal contact, and co-infection of QF with these diseases should be considered. [ABSTRACT FROM AUTHOR]

The design, construction and commissioning of a beamline and spectrometer for inelastic soft X-ray scattering at high resolution in a highly efficient system are presented. Based on the energy-compensation principle of grating dispersion, the design of the monochromator-spectrometer system greatly enhances the efficiency of measurement of inelastic soft X-rays scattering. Comprising two bendable gratings, the set-up effectively diminishes the defocus and coma aberrations. At commissioning, this system showed results of spin-flip, d-d and charge-transfer excitations of NiO. These results are consistent with published results but exhibit improved spectral resolution and increased efficiency of measurement. The best energy resolution of the set-up in terms of full width at half-maximum is 108 meV at an incident photon energy tuned about the Ni L3-edge. [ABSTRACT FROM AUTHOR]

Kawasaki disease (KD) is the most common form of pediatric vasculitis. Though its etiology is unknown, researchers have suggested that it is related to genetics. The inositol 1,4,5-triphosphate receptor type 3 ( ITPR3) gene has a strong association with the development of type 1 diabetes and, plays a critical role in the development of autoimmune diseases such as systemic lupus erythematosus, rheumatoid arthritis, and Graves' disease. The aim of study is to examine the association of ITPR3 polymorphisms with KD risk in Taiwanese children. This study evaluates the single nucleotide polymorphisms (SNP) rs2229634 in the ITPR3 gene with KD in a case-control study involving 93 KD patients and 680 healthy, gender- and age-matched controls. The frequency of the rs2229634 T/T genotype was significantly higher in KD patients with coronary artery aneurysm (CAA) than in patients without CAA [odds ratio (OR) = 2.56, 95% confidence interval (95% CI) = 1.35-4.88, P = 0.004]. In addition, KD patients with the T/T genotype elevated mean serum levels of C-reactive protein compared with patients with the C/C or C/T genotype (12.2 mg dL vs. 8.5 mg dL, P = 0.036). In conclusion, the results of this study suggest that the rs2229634 SNP in the ITPR3 gene is associated with the risk of CAA formation in Taiwanese KD patients. [ABSTRACT FROM AUTHOR]

Background: The purpose of the study is to investigate the epidemiology and medical expenses of Wilson’s disease in Taiwan. Methods: Cases of Wilson’s disease were identified from the National Health Insurance Research Database with corresponding International Classification of Diseases, Ninth Revision (ICD-9) code 275.1 from January 2000 to December 2005. Age and sex-specific incidences were estimated by dividing the incidence number by population data obtained from the Department of Statistics, Ministry of the Interior. Results: During the study period, 495 cases of Wilson’s disease were identified. The male to female ratio was 1.28. The average annual incidence rate was 0.27 per 100 000, and the incidence rate peaked in the age group of 15–19 years. Most cases were juvenile and young adults. The prevalence increased steadily during the study period. Cirrhosis of the liver was the most common co-existing condition. Conclusions: This is the first population-based epidemiologic study of Wilson’s disease in Taiwan. Because of the effective and affordable treatment, the prevalence of Wilson’s disease in Taiwan is expected to increase continuously. [ABSTRACT FROM AUTHOR]

Background: The purpose of the study was to investigate the diagnostic yield and clinical utility of open muscle biopsy and to identify pre-biopsy factors that might predict useful clinical results for suspected myopathy. Methods: Two-hundred fifty-eight muscle biopsies, performed for investigation of suspected myopathy, were evaluated. Results: A specific clinical diagnosis following muscle biopsy was made in 43% of cases. As a result of the biopsy, clinical diagnosis was changed in 47% and treatment was changed in 33% of cases. Results either led to a specific clinical diagnosis or changed the diagnosis/treatment in 74% of patients. Positive family history of myopathy and findings of myopathic irritability on electromyography had a negative predictive value for diagnosis change. Conclusions: Open muscle biopsy is useful in myopathy evaluation in the modern genetic era. [ABSTRACT FROM AUTHOR]

This multicenter study evaluated the mutation spectrum and frequencies of the MLH1 and MSH2 genes and determined the occurrence of large genomic deletions in 93 unrelated Taiwanese families that fulfilled the Amsterdam criteria II by denaturing high-performance liquid chromatography analysis, DNA sequencing for aberrant chromatograms, and multiplex ligation-dependent probe amplification analysis. In total, 38 pathogenic mutations (10 large deletions and 28 point mutations or small deletion/insertions) in the MSH2 or MLH1 gene were identified in 61 of the 93 families (66%). Three of the 10 large deletions and 14 of the 28 point mutations or small insertions/deletions have not been reported elsewhere. Three mutations in the MLH1 gene, the MLH1c.1846_1848delAAG (5 families), deletion exons 11–15 (4 unrelated families), and MLH1c.793C>T (13 unrelated families), accounted for 35% of all cases with pathogenic mutations. Haplotype analysis indicated that mutant c.793C>T alleles were derived from two distinct common founders that might be inherited from a single ancestor of presumably Chinese origin. As a mutation detection strategy for Taiwanese Lynch syndrome patients, we recommend that diagnosis starts with screening for large genomic deletions and continues by screening for common mutations in exons 10 and 16 of the MLH1 gene prior to searching for small mutations in the remaining exons. [ABSTRACT FROM AUTHOR]

The article discusses the study which identifies genetic variants in the major histocompatibility complex (MHC) region associated with kawasaki disease and the development of coronary artery anerurysmss in Taiwan. The study analyzed the cohort study of 93 Taiwanese patients and 680 unrelated healthy children for sex and age with the study patients with genetic influence. The study suggests that the genotype of the gene polymorphism played an important role in the pathogenesis of kawasaki disease.

Experiential learning is the process of creating knowledge through the transformation of experience and has been adopted in an increasing number of areas. This paper investigates the possibility of technological support for experiential learning. A learning activity flow (or script) and a mobile technology system were designed to facilitate students in experiential learning. An experiment was conducted on two fifth-grade classes at an elementary school, one class using personal digital assistants (PDAs) and the other working without them. The results indicate that mobile technologies are effective in improving knowledge creation during experiential learning. The interplay between the mobile technology affordances and the proposed learning flow for experiential learning is thoroughly discussed. [ABSTRACT FROM AUTHOR]

Background: To our knowledge, the association of the five serotypes of Actinobacillus actinomycetemcomitans (A. actinomycetemcomitans) to the new diagnostic classification scheme defined by the American Academy of Periodontology in 1999 has not yet been described. The goal of this study was to characterize the frequencies of the five serotypes of A. actinomycetemcomitans in A. actinomycetemcomitans isolates from various forms of periodontitis using both old and new diagnostic classifications and to determine the relationships between serotype and age and clinical diagnosis. Methods: A total of 345 A. actinomycetemcomitans isolates from 115 A. actinomycetemcomitans culture-positive subjects (mean age 38.0 ± 18.3 years, 59% female) were collected. Based on the new classifications, 33 subjects had aggressive periodontitis and 82 chronic periodontitis. According to old classifications, there were sis prepubertal periodontitis (PPP), 12 localized juvenile periodontitis (LJP), 15 post-localized juvenile periodontitis (PLJP), 28 refractory periodontitis (Ref-P), and 54 adult periodontitis (AP) cases. Serotypes of A. actinomycetemcomitans were determined by an indirect immunofluorescence assay using serotype-specific polyclonal antisera to A. actinomycetemcomitans strains ATCC 29523, ATCC 43728, ATCC 33334, IDH 781 and IDH 1705 (serotype a, b, c, d, and e, respectively). Proportions of serotype b were examined between different diagnostic and age groups with a Z-test for proportions. Results: Most subjects (n = 100, 86.96%) were infected with a single serotype (22 serotype a, 44 serotype b, 30 serotype c, 1 serotype d, and 3 serotype e). There were 11 subjects (9.57%) with two serotypes and two subjects (1.74%) with 3 serotypes. Two individuals had isolates lacking any detectable serotype antigen. Serotype b was the predominant serotype in children under 18 years of age and young adults between 19 to 35 years, although serotype b status was not significantly associated with age. Serotypes d and e were not found in patients under 35 years old. In 62 adult patients, one subject had serotype d and three had serotype e. Serotype b was the most common serotype in aggressive periodontitis (60.61%). The proportion of cases with serotype b was significantly higher in aggressive periodontitis compared to chronic periodontitis (P = 0.031). Other serotypes were not significantly associated with new diagnostic categories. Serotypes d and e were not detected in aggressive periodontitis. Conclusion: The results of this study show that proportions of serotype b of A. actinomycetemcomitans are significantly greater in culture-positive patients with aggressive periodontitis than those with chronic periodontitis. [ABSTRACT FROM AUTHOR]

Aim: To evaluate Helicobacter pylori primary resistance and its clinical impact on the efficacy of two lansoprazole-based eradication triple therapies. Methods: H. pylori-positive patients (n=228) were randomized to receive one of the 1-week regimens: lansoprazole 30 mg, clarithromycin 500 mg and amoxicillin 1 g (LAC), or lansoprazole 30 mg, clarithromycin 500 mg and metronidazole 500 mg (LMC), each given twice daily. H. pylori status was assessed by 13C-urea breath test and culture at diagnosis and by 13C-urea breath test 6 weeks after therapy. Antibiotic susceptibility was determined by E-test (n=98). Results: The eradication rates with per protocol/ intention-to-treat analyses were: LAC (n=95/114) 83%/69% and LMC (n=96/114) 85%/72%. Primary resistance was 11% for clarithromycin, 41% for metronidazole and 0% for amoxicillin. Eradication in metronidazole-susceptible/-resistant strains was 85%/82% in LAC and 83%/63% in LMC. Significantly lower cure rates were observed in clarithromycin-resistant patients treated with LAC (95% vs. 0%, P < 0.001) and LMC (86% vs. 0%, P < 0.001). Conclusions: One-week LAC and LMC are similarly effective therapies. Clarithromycin resistance significantly affected H. pylori eradication in both regimens. [ABSTRACT FROM AUTHOR]

SummaryFrom October 1997 to September 1998, 3085 Culex quinquefasciatus (Say) (Diptera: Culicidae), 584 Cx. tritaeniorhynchus (Giles) (Diptera: Culicidae), 392 Cx. annulus (Theobald) (Diptera: Culicidae), 374 Aedes albopictus (Skuse) (Diptera: Culicidae) and 102 Armigeres subalbatus (Coquillet) (Diptera: Culicidae) were collected and examined for Dirofilaria immitis (Leidy) (Spirurida: Filariidae) infection. However, only Cx. quinquefasciatus and Ae. albopictus were infected, with a prevalence of 4.28% and 3.74%, respectively. The intensity of D. immitis found in Ae. albopictus (3.43 larvae/mosquito) was higher than that found in Cx. quinquefasciatus (2.89 larvae/mosquito). After being fed with canine blood containing 7500 microfilariae (mf) per mL, Cx. quinquefasciatus ingested approximately two times as many mf as Ae. albopictus (mean of 31.73 in comparison to 16.47). However, almost three times as many third-stage infective larvae developed in Ae. albopictus as in Cx. quinquefasciatus (mean of 3.25 as compared with 1.10), with a vector efficiency index (VEI) of 19.73 and 3.47, respectively. The results showed that Cx. quinquefasciatus and Ae. albopictus served as natural vectors of D. immitis in central Taiwan. Although Ae. albopictus was more efficient for heartworm transmission, Cx. quinquefasciatus may play a more prominent role on the transmission of dirofilariasis in central Taiwan. [ABSTRACT FROM AUTHOR]

13 patients with untreated adult periodontitis (AP) were compared to 8 subjects free of periodontal disease (H) with respect to plaque index (PlI), gingival index (GI), probing depth (PD) and differential counts of subgingival bacterial morphotypes from a pooled sample of 6 surfaces with the greatest probing depth. Serum antibody levels to T. vincentii and T. denticola strains were also determined in these subjects as well as in the sera from 5 subjects with localized juvenile periodontitis (LJP). Subjects with AP had significantly elevated proportions of spirochetes and motile rods and lower proportions of coccoid cells than H subjects. They also exhibited significantly higher PlI and GI scores and greater probing depths. Antibody levels were normalized against a standard serum and expressed as ELISA units (EU). IgA and IgG antibody levels to all tested spirochete strains were significantly elevated in AP subjects as compared to subjects in group H or subjects with LJP. No significant differences in antibody titers were detectable between the H and LJP groups with respect to any of the tested strains. No significant correlation could be demonstrated between serum antibody titers to any of the oral spirochete strains tested and the proportions of oral spirochetes determined microscopically. [ABSTRACT FROM AUTHOR]

Circulating antibody levels to four strains of Actinobacillus actinomycetemcomitans (Aa) were determined by means of an indirect immunofluorescent technique in three groups of 21 subjects each, including one with juvenile periodontitis (JP), one with chronic periodontitis (CP) and one free of periodontal disease (N). Mean levels of antibody to Aa were significantly elevated in the JP group as compared to the CP and N groups with respect to strains Y4, 29522 and 29524, but not strain 29523. Since strains Y4, 29522 and 29524 contain a leukotoxin that is missing from strain 29523, the results suggest that the leukotoxin could account for the difference in the immune response among the three groups of subjects. Varying the end-point considered to represent positive fluorescence did not significantly affect the results, although discrimination among the three groups appeared to be somewhat better at lower intensities of fluorescence. Because of wide variations in antibody titers recorded in individual subjects, elevated levels of antibody to certain strains of Aa may not be useful as a primary diagnostic test for JP, but may be of value in confirming an otherwise uncertain clinical diagnosis. [ABSTRACT FROM AUTHOR]

A total of 177 Actinobacillus actinomycetemcomitans isolates from 136 periodontally healthy or diseased subjects were serotyped by indirect immunofluorescence and/or immunodiffusion assays. Serotype-specific rabbit antisera against A. actinomycetemcomitans serotypes a, b and c were used. All 3 serotypes were commonly found in the study subjects. Serotype b was dominant in subjects with periodontal disease and serotype c was the most common serotype in the healthy subjects. In the immunofluorescence assay, when 85 isolates were cultured anaerobically and fixed in acetone, or cultured aerobically in 10% CO2 and heat-fixed, 60 isolates revealed the same serotypes. The remaining 25 isolates reacted with 2 of the serotype-determining reagents. In the immunodiffusion assay, 22 of these 25 isolates reacted with one antiserum only. These results suggest differences in the distribution of A. actinomycetemcomitans serotypes between periodontal health and disease and point to possible variation in serotype determination due to bacterial growth and preparation procedures. [ABSTRACT FROM AUTHOR]

Bacteroides forsythus, a newly named species from the human mouth, possesses a distinct cell wall ultrastructure and a unique set of cell surface antigens. To determine the distribution of B. forsythus in the periodontal region, supragingival plaque was collected from 16 healthy adults and from 11 adults with mild gingivitis, 12 with severe gingivitis and 17 with periodontitis. Subgingival samples from 27 diseased sites were examined as well. B. forsythus was located in plaque smears by indirect immunofluorescence microscopy. Rabbit antibody to B. forsythus strain FDC 335 constituted the primary antibody and fluorescein-labelled goat-antirabbit antibody the secondary antibody. There was a significant difference (p< 0.05) between the proportions of B. forsythus in supragingival samples of healthy subjects (0.2%) vs. individuals with mild gingivitis (1.3%), severe gingivitis (1.0%) and adult periodontitis (0.9%). A significant difference (p<0.001%) in B. forsythus proportions was also detected between supragingival (0.9%) and subgingival (15.3%) samples from adult periodontitis patients. In a separate study, patients previously treated for moderate to severe adult periodontitis were monitored over a 12-month period for evidence of disease recurrence. A significant increase in the proportions of B. forsythus was found at sites with breakdown as compared to stable sites. Breakdown was defined as loss of attachment of 2 mm or more from base line, as measured from a reference stent, or a probing depth increase of 3 mm or more. These results support the assertion that B. forsythus is associated with advanced periodontitis as well as recurrent periodontitis. Monitoring the subgingival proportions of B. forsythus may be of diagnostic value in patients on maintenance therapy. Whether B. forsythus causes periodontal disease or is a secondary colonizer of periodontal lesions. [ABSTRACT FROM AUTHOR]

Optimal conditions for labelling Actinomyces viscosus (T14V) in thin sections by an indirect immunoperoxidase technique are described. The influence of several fixatives on the degree of labelling of bacterial cells was tested in pure cultures and in dental plaques. Some pure cultures were also processed without prior fixation. The effect of different incubation conditions on the degree of labelling was evaluated in pure cultures. The optimal labelling conditions included fixation with paraformaldehyde (4 %) plus glutaraldehyde (0.25 %), incubation with highly diluted rabbit anti-T14V γ-globulin for 24 hours at 4°C, followed by incubation with diluted sheep anti-rabbit IgG conjugated to horseradish peroxidase, and subsequent histochemical visualization of the peroxidase. Optimal labelling conditions were used to check for cross-reactions between the anti-T14V γ-globulin and some common oral bacteria. The well-known cross-reaction with Actinomyces naeslundii was noted, as well as a slight cross-reaction with Bacterionema matruchotii. Optimal conditions were used for labelling sections of dental plaques. Wide variations were observed in the number of labelled cells. Cells labelled with anti-T14V γ-globulin were unlabelled when consecutive sections of these cells were treated with control normal rabbit serum γ-globulin or anti-Streptococcus mutans γ-globulin. Cells labelled with anti- T14V γ-globulin tended to be cocco-bacillary in shape in the saperficial layers of plaque. The deeper layers exhibited more filamentous forms. These observations are compatible with the known pleomorphism of A. viscosus in vitro. [ABSTRACT FROM AUTHOR]

Whole genomic and randomly-cloned DNA probes for two fastidious periodontal pathogens. Porphyromonas gingivalis and Bacteroides forsythus were labeled with digoxigenin and detected by a colorimetric method. The specificity and sensitivity of the whole genomic and cloned probes were compared. The cloned probes were highly specific compared to the whole genomic probes. A significant degree of cross-reactivity with Bacteroides species. Capnocytophaga sp. and Prevotella sp. was observed with the whole genomic probes. The cloned probes were less sensitive than the whole genomic probes and required at least 105 of target cells or a minimum of 10 ng of target DNA to be detected during hybridization. Although a ten-fold increase in sensitivity was obtained with the whole genomic probes, cross-hybridization to closely related species limits their reliability in identifying target bacteria in subgingival plaque samples. [ABSTRACT FROM AUTHOR]

The article discusses the distribution and role of Wolinella recta in the adult periodontitis. Wolinella recta is a Gram-negative polar flagellated anaerobic motile rod isolated from advanced periodontal lesions and from infected pulp tissue. By transmission electron microscopy W. recta is characterized by an unusual cell wall structure. The outer surface of the outer membrane consists of an array of distinctive, hexagonally packed macromolecular subunits. This finding suggests that the cell wall might contain specific antigenic determinants unique to W. recta.

A miniaturised rat‐race coupler capable of suppressing the second and third harmonics is proposed. The coupler is designed with slow‐wave synthesised transmission lines using two π‐networks in cascade. Each π‐network is formed by a parallel LC tank and two shunt capacitors, and is associated with a transmission zero for harmonic attenuation. The two transmission zeros embedded in the synthesised line can be controlled independently. The proposed rat‐race coupler, centred at 2.4 GHz with an operational bandwidth of 18.8%, and at least 21‐dB suppression at the second and third harmonics, features a compact footprint, which is only 12.9% the size of its conventional counterpart. [ABSTRACT FROM AUTHOR]

The aims of the study were to determine the prevalence of simultaneously multiple Actinobacillus actinomycetemcomitans serotypes in one individual, stability of infection by the same serotype and the occurrence of previously not described serotypes of A. actinomycetemcomitans. The serotypes of 515 clinical isolates of A. actinomycetemcomitans from 91 Finnish, Caucasian subjects, including 321 followup samples from 51 subjects, were determined with immunodiffusion assay. Most subjects (n=86, 95%) were infected with one serotype only; 466 (91%) isolates from 80 subjects belonged to serotype a (25% of isolates/25 subjects),b (25% of isolates/27 subjects) or c (41% of isolates/30 subjects). Fifteen isolates from 4 subjects reacted with the antiserum raised against previously untypable clinical strain IDH 781 (serotype d) and 18 isolates form 5 subjects with the antiserum raised against strain IDH 1705 or IDH 3096 (serotype e.) Sixteen (3%) isolates from 5 subjects remained untypable. The same infecting A. actinomycet- emcomitans serotype(s) persisted for the 1-6 years of follow-up. In conclusion, the study indicates a rare simultaneous occurrence of multiple oral A. actinomycetemcomitans serotypes, the stability of infection by the same serotype(s) and the existence of serotypes of A actinomycetemcomitans not previously described. [ABSTRACT FROM AUTHOR]

In humans spirochetes are conspicuous inhabitants of subgingival bacterial deposits, situated primarily at the peripheral surface of plaque in direct contact with epithelium and emigrating leukocytes. In the absence of added serum. PMNs released minimal amounts of lysosomal enzymes in response to intact spirochetes. This can be contrasted to other suspected periodontal pathogens which promote more vigorous release reactions. The results of PMN chemotaxis measurements indicated that spirochete derived sonic extracts failed to trigger significant chemotaxis in the absence of serum.

This study examined the distribution of P. gingivalis, P. intermedia and B. forsythus in plaque on metallic and porcelain pontics adjacent to healthy and inflamed mucosa. Subpontic plaque was collected from 33 inflamed and 31 healthy sites. Plaque suspension was incubated with specific rabbit antisera to P. gingivalis (FDC 381), P. intermedia (ATCC 25261) and B. forsythus (FDC 335), and the labelled cells disclosed with fluorescein-labelled goat-anti-rabbit IgG by indirect immunofluorescence microscopy. Mean proportions of P. gingivalis, P. intermedia, and B. forsythus at inflamed sites were 0.60+/-0.75, 2.48+/-2.28, and 0.44+/-0.64% respectively, and at healthy sites 0.21+/-0.43, 1.27+/-1.05, and 0.15+/-0.18% respectively. These differences were statistically significant. Almost all sites were positive for P. intermedia, whereas only 12/31 healthy and 21/33 inflamed sites were positive for P. gingivalis. 18/31 healthy and 28/33 inflamed sites were positive for B. forsythus. P. intermedia was recovered in higher proportions from metallic pontics adjacent to inflamed sites (MI) than healthy sites (MH) or porcelain pontics next to inflamed (PI) or healthy sites (PH). P. gingivalis is was recovered in higher proportions from MI than PH. We conclude that both the nature of the pontic material and the health status of the mucosa affect the composition of the associated microbiota.

Actinobacillus actinomycetemcomitans has been associated with different forms of periodontitis, particularly with localized juvenile periodontitis (LJP). The bacterium possesses several virulence factors which have been shown to interact with the host immune system. Among these factors, leukotoxin, surface antigens (serotype) and bacteriophages have been suggested directly or indirectly to influence the course of infection. However, few studies have been able to show associations between these factors and periodontal disease, alone or in combination. Thus, the purpose of the present study was to investigate possible correlations between periodontal disease status and selected virulence factors (serotype, presence of bacteriophages, and the presence of a 530 bp deletion in the promoter region of the leukotoxin gene). 36 subjects took part in the study. Serotype c was the most frequently found serotype among periodontally affected subjects, although serotypes a and b were also present. 27 out of 36 strains harbored bacteriophages, and there was strong evidence that some of the bacteriophages were different from the previously characterized phi Aa phage. A. actinomycetemcomitans containing the F-fragment phage were more frequently associated with periodontal disease. Five strains, all serotype b, 3 from LJP patients and 2 from healthy subjects, showed a 530-bp deletion in the promoter region of the leukotoxin gene.

Whole genomic and randomly-cloned DNA probes for two fastidious periodontal pathogens, Porphyromonas gingivalis and Bacteroides forsythus were labeled with digoxigenin and detected by a colorimetric method. The specificity and sensitivity of the whole genomic and cloned probes were compared. The cloned probes were highly specific compared to the whole genomic probes. A significant degree of cross-reactivity with Bacteroides species, Capnocytophaga sp. and Prevotella sp. was observed with the whole genomic probes. The cloned probes were less sensitive than the whole genomic probes and required at least 10(6) target cells or a minimum of 10 ng of target DNA to be detected during hybridization. Although a ten-fold increase in sensitivity was obtained with the whole genomic probes, cross-hybridization to closely related species limits their reliability in identifying target bacteria in subgingival plaque samples.

Wolinella recta has been associated with adult periodontitis, but its role in the disease remains uncertain. This report clarifies the distribution of W. recta in periodontally healthy and diseased subjects, and treated patients with recurrent disease. A specific polyclonal rabbit antiserum against W. recta strain 372 was used for indirect immunofluorescence localization of W. recta in dental plaque from untreated and treated patients. Supragingival plaque was collected from 15 periodontally healthy individuals (H), 10 adults with mild gingivitis (G1), 8 with severe gingivitis (G2) and 15 with periodontitis (AP). Subgingival samples from 23 diseased sites (G2 and AP) were examined as well. There was a significant difference (p = 0.000) between the proportions of W. recta in subgingival (4.4%) vs. supragingival (0.3%) plaque samples from AP. A significant difference (p = 0.000) in W. recta proportions was also detected between subgingival plaque samples of AP (4.4%) vs. G2 (1.2%). No significant difference in the mean % of W. recta was found between supragingival plaque of AP (0.3%) and G2 (0%), and samples of G1 (0.01%) and H (0.1%). In a separate study, 85 adults previously treated for moderate to severe adult periodontitis were monitored over a 12-month period for evidence of disease recurrence. Recurrent disease was detected at 32 sites in 18 subjects. Of these, 20 sites in 13 subjects were positive for W. recta. With subjects as the experimental unit, a significant increase in the proportions of W. recta was found at sites with recurrent disease (3.12%) as compared to stable, paired control sites (0.24%), but only when sites with breakdown and positive for W. recta were compared with their controls. These results indicate that W. recta is associated with some, but not all sites with advanced adult periodontitis. The association of W. recta with gingivitis was not statistically significant.