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Biomedical subjects

A Tanner

Publications and source records attributed to A Tanner.

At least 55 records · Page 3Linked to original sources
PubMed1994

Changes in root canal microbiota during the development of rat periapical lesions.

Periapical lesions are reproducibly induced in rats by pulp exposure and infection from the oral cavity. Lesions expand rapidly between day 7 and day 15-20 (active phase), with slowed expansion thereafter. In the present study we characterized the root canal microbiota present during the active phase of lesion development in this system. The mandibular first molars of Sprague-Dawley rats were exposed on day 0. The teeth were extracted after 7 days (n = 10 animals) and 15 days (n = 10), and the microbiota present in roots was isolated and characterized. The number of colonies isolated per tooth was similar on day 7 (1.53 +/- 0.64 colony-forming units x 10(3)) and day 15 (1.49 +/- 0.37 colony-forming units x 10(3)). No colonies were isolated from unexposed control teeth. Anaerobic bacteria increased significantly between day 7 (24.3 +/- 5.7%) and day 15 (47.3 +/- 7.5%), and the proportion of gram-negative organisms increased from day 7 (24.3 +/- 6.1) to day 15 (46.9 +/- 6.8). The predominant bacteria included, on day 7: Streptococcus and Bacteroides species; on day 15: species of Streptococcus, Bacteroides, Prevotella, Neisseria and Peptostreptococcus. Streptococcus oralis, Streptococcus mitis, Streptococcus rattus, Bacteroides pneumosintes and Bacteroides ureolyticus were frequently isolated at both points. Although approximately the same mean number of different species (approximately 3.5) was isolated per tooth on both day 7 and 15, the overall diversity of the isolates increased on day 15.(ABSTRACT TRUNCATED AT 250 WORDS)

Alveolar Bone Loss↗
PubMed1994

Diagnostic pitfall; interpretation of CA 19-9 concentrations in the presence of hepatic dysfunction.

A 50 year old man is described with hepatic dysfunction and chronic pancreatitis in whom greatly increased concentrations of the pancreatic tumour marker CA 19-9 combined with an abnormal appearance at endoscopic retrograde cholangiopancreatography lead to the false suspicion of pancreatic carcinoma. CA 19-9 concentrations should be interpreted with caution in patients with intrinsic liver disease or biliary obstruction.

Antigens, Tumor-Associated, Carbohydrate↗
PubMed1993

Oral and dental infections with anaerobic bacteria: clinical features, predominant pathogens, and treatment.

Microbial populations colonizing the teeth are a major source of pathogens responsible for oral and dental infections, including periodontal diseases, gingivitis, pericoronitis, endodontitis, peri-implantitis, and postextraction infections. Each entity has distinct clinical and microbial features. Bacterial species associated with oral infections include Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, Prevotella intermedia, Bacteroides forsythus, Campylobacter rectus, Eubacterium species, Fusobacterium nucleatum, Eikenella corrodens, and Peptostreptococcus micros. Treponema pallidum-related spirochetes have been associated with acute necrotizing ulcerative gingivitis. Porphyromonas endodontalis appears to be specifically related to endodontic infections. Oral infections in medically compromised patients, including those with AIDS, are associated with similar species and are usually complicated by superinfection with enteric and Candida species. Isolation of species causing oral infections requires the collection of appropriate samples and the use of strictly anaerobic techniques. Rapid selective culture, immunofluorescence, and DNA probe methods have been developed for the identification of these oral species. The varied measures required in the management of oral and dental infections may include antimicrobial therapy. Accurate microbiological diagnosis, including antibiotic susceptibility testing, is indicated for cases that do not respond to therapy.

Bacteria, Anaerobic↗
PubMed1993

Use of fine needle aspiration cytology for investigating lymphadenopathy in HIV positive patients.

The cytological diagnoses of 27 lymph node aspirates were compared with the histological diagnoses or clinical outcome in 23 HIV positive patients. There was agreement between the cytological and histological diagnoses in 14 of the 16 surgically biopsied cases. The clinical outcome in the remaining 11 cases was consistent with the cytodiagnosis. Fine needle aspiration (FNA) is a reliable, minimally traumatic, cost effective method with high specificity. It is suitable for an initial rapid diagnosis in HIV positive patients with lymphadenopathy.

Adult↗
PubMed1992

Identification of Selenomonas species by whole-genomic DNA probes, sodium dodecyl sulfate-polyacrylamide gel electrophoresis, biochemical tests and cellular fatty acid analysis.

Nonisotopic, whole-genomic DNA probes, sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), biochemical tests in microtiter trays and cellular fatty acid (CFA) analysis were compared for the identification of 5 oral Selenomonas species. DNA probes were prepared by biotin-labeling DNA extracted from the type strains of Selenomonas noxia, Selenomonas flueggei, Selenomonas artemidis, Selenomonas infelix and Selenomonas sputigena. The probes were hybridized with DNA from 21 reference strains, 18 fresh isolates of Selenomonas species, and 21 strains of other oral gram-negative species. Target DNAs were obtained by in situ extraction of colonies blotted onto filter paper. Streptavidin-linked alkaline phosphatase was used to detect homologous reactions of probe and target DNA. Each Selenomonas species DNA probe reacted with reference strains of only that species. All Selenomonas strains that reacted with the DNA probe for a particular species gave similar biochemical test results, SDS-PAGE protein profiles, and CFA profiles to those of the type strain of the corresponding species. All the methods tested were useful for identifying the species, and all yielded similar identifications of the fresh isolates. The DNA probes, however, had the potential for identifying Selenomonas species directly from primary isolation plates or plaque samples.

Bacteroidaceae↗
PubMed1992

Antibiotic resistance of the subgingival microbiota following local tetracycline therapy.

The antibiotic resistance of the subgingival microbiota was studied by 3 approaches. First, we assessed the ability of subgingival isolates taken following therapy to grow on media containing tetracycline (TC). Higher percentages of TC-resistant organisms appeared at TC fiber-treated periodontal sites and within the saliva 1 week after treatment as compared with pre-treatment levels. By 1 month, the percentage of TC-resistant organisms had returned to levels comparable to those seen before treatment. In the second approach, subgingival isolates taken following therapy were grown on media without antibiotics, and isolates were selected for Gram-stain and cell morphology determination. This study indicated that subgingival sites became colonized with gram-positive cocci in the same time period that an increase of TC-resistant isolates was observed in the first study. This may account for the transient increase in TC resistance, because many gram-positive cocci are intrinsically resistant to TC. In the third approach, the antibiotic resistance of subgingival gram-negative species was determined. The predominant cultivable microbiota of 9 sites from 3 subjects were isolated immediately before and 6 months after TC fiber treatment. Gram-negative rods were characterized and tested for sensitivity to TC (minimum inhibitory concentration [MIC] 1-128 micrograms/ml), penicillin at 80 micrograms/ml, and erythromycin at 8 micrograms/ml. None of the gram-negative rods were resistant to TC (MIC greater than or equal to 16 micrograms/ml), either before or after treatment. Before treatment 98% of the gram-negative rods were susceptible to TC at 1-2 micrograms/ml and after therapy 88% were susceptible.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

Microbial etiology of periodontal diseases. Where are we? Where are we going?

Many studies indicate a strong association of Actinobacillus actinomycetemcomitans with localized juvenile periodontitis. Species associated with adult periodontitis include Bacteroides forsythus, Porphyromonas gingivalis, Prevotella intermedia, A. actinomycetemcomitans, and Wolinella recta. Capnocytophaga species may be important in pubertal gingivitis. An unnamed spirochete related to Treponema pallidum has been identified in acute necrotizing ulcerative gingivitis lesions. Species isolated from prepubertal periodontitis, peri-implantitis, pericoronitis, and human immunodeficiency virus gingivitis and periodontitis are similar to those isolated from periodontal and gingival infections. Species identification in combination with clinical characteristics facilitates periodontal diagnosis. DNA probes, immunoassays, and benzoyl-arginine naphthylamide reactivity methods can be used to indicate putative pathogens in plaque samples. Microbial identification aids in antibiotic selection and planning a treatment regimen.

Actinomyces↗
PubMed1991

Identification of oral yeasts by polyacrylamide gel electrophoresis.

Protein profiles of sonicated cells for 9 species of yeast isolated from oral samples were obtained by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), and visualized with a silver stain. The profiles obtained on 12% acrylamide gels were distinct, and characteristic for 6 species of Candida, and Torulopsis glabrata, Yarrowia lipolytica, and Saccharomyces cerevisiae. Using this method, 79 fresh isolates of yeasts from saliva samples were identified; 58 as Candida albicans, 9 as Candida parapsilosis, 1 as Candida tropicalis, and 11 as T. glabrata. SDS-PAGE offers a rapid, convenient alternative or adjunct to yeast identification systems based on carbohydrate assimilation tests.

Adult↗
PubMed1991

Multicenter evaluation of tetracycline fiber therapy. III. Microbiological response.

In a multicenter study of the effects of tetracycline (TC) fiber therapy, subgingival plaque samples were tested for 6 probable periodontal pathogens by DNA probe analysis. Levels of Actinobacillus actinomycetemcomitans, Eikenella corrodens, Fusobacterium nucleatum, Porphyromonas (Bacteroides) gingivalis, Prevotella intermedia (Bacteroides intermedius), and Wolinella recta were quantitatively determined in samples taken at baseline, and immediately after TC fiber removal, control fiber removal, and scaling and root planing. At untreated sites, samples were taken at baseline and 10 d later. Specificity of the DNA probe method was evaluated by testing the hybridization to 83 reference cultures. Interaction of the F. nucleatum probe with Fusobacterium periodonticum, and of the W. recta probe with Wolinella curva were the only cross-hybridizations noted. Species were detected at an average sensitivity of 2.9 x 10(4) organisms per sample. Approximately 70% of sites were initially infected with P. gingivalis and F. nucleatum; 50% with P. intermedia and E. corrodens; infections with W. recta and A. actinomycetemcomitans were less common (36% and 11% respectively). The average numbers of organisms found in the plaque samples were highest for F. nucleatum, P. gingivalis, and P. intermedia (ca. 10(6)). E. corrodens, W. recta, and A. actinomycetemcomitans occurred at 10-fold lower levels. Bacterial numbers and proportions of species in subgingival sites from the five centers did not differ appreciably. Both TC fiber therapy and scaling decreased the number of sites infected with all the monitored species. The bacterial composition at untreated sites and at sites where control fibers were placed was not significantly altered. The percentage reduction of the number of sites with detectable infection varied with each species: from 86% with W. recta to approximately 40% with P. gingivalis. Significant reduction of pocket depth and bleeding occurred at TC fiber-treated sites infected with each of the species. Significant attachment level gain occurred only at sites initially infected with P. gingivalis and treated with TC fibers.

Actinobacillus↗
PubMed1991

Tetracycline fiber therapy monitored by DNA probe and cultural methods.

Oligonucleotide DNA probe and selective cultural methods were compared in their ability to monitor 6 putative periodontal pathogens in a study evaluating local tetracycline fiber therapy. Subgingival plaque was sampled from 4 sites in each of 20 subjects. Samples were taken before and after therapy from sites assigned to the following test groups: tetracycline (TC) fiber, scaling and root planing, control fiber, and untreated. Each sample was analyzed by both DNA probe and cultural methods. Total anaerobic cultivable counts, Porphyromonas (Bacteroides) gingivalis and Prevotella intermedia (Bacteroides intermedius) were enumerated on nonselective blood agar. Actinobacillus actinomycetemcomitans, Eikenella corrodens, Fusobacterium nucleatum and Wolinella recta were isolated on selective media. TC fiber therapy and scaling reduced total cultivable counts from an initial value of 1 x 10(7) to approximately 2 x 10(5) following therapy. Total counts at untreated sites and at sites with control fibers did not change from baseline. A. actinomycetemcomitans and E. corrodens were detected more frequently by the cultural method; the other monitored species were detected more frequently by DNA probes than by the cultural methods. Agreements between methods were: 77.2% for A. actinomycetemcomitans; 72.2% for P. intermedia; 75.6% for E. corrodens; 39.4% for F. nucleatum; 35.6% for P. gingivalis; and 68.9% for W. recta. Limitations of the selective cultural methods used probably contributed to the discrepancies for P. gingivalis and F. nucleatum. DNA probe and cultural methods indicated comparable levels of suppression of the monitored species following TC fiber therapy and scaling. The microbiota of control fiber and untreated sites did not appear to be significantly altered by either method.

Actinobacillus↗
PubMed1989

The microbiota of early periodontitis lesions in adults.

The predominant cultivable microbiota of shallow progressive (active) periodontal lesions in 4 adults (29-40 years) was compared to that of shallow inactive sites. Periodontal attachment levels were monitored longitudinally, and sites showing 2-3 mm attachment loss in the previous 1-2 months were considered disease active. Inactive sites showed no change in attachment level. The microbiota of shallow sites was dominated by gram negative rod species including Wolinella recta, Bacteroides forsythus, and Fusobacterium nucleatum. W. recta was isolated in higher incidence and proportions from the active compared to inactive sites, and showed a positive relationship to bleeding on probing. Cluster analysis of species isolated from sites grouped sites from each individual together. This preliminary investigation suggested that a similar range of pathogens may be related to early periodontitis in adults as that previously reported for advanced diseased sites, and that different subjects may demonstrate different periodontal infections.

Adult↗
PubMed1989

Prevention of early recurrence of high risk malignant melanoma by coumarin. Irish Melanoma Group.

Coumarin (1,2-benzopyrone) as a daily oral dose of 50 mg was evaluated in a multicentre prospectively randomized, double-blind, placebo-controlled trial to prevent early recurrence of malignant melanoma TNM Stage IB (Breslow thickness greater than 1.70 mm) and Stage II. Intake for the trial started in 1984 and was stopped prematurely, after review, in 1987. There were two recurrences in 13 treated patients and 10 in 14 controls which was significant (P 0.01). The sites of the metastases differed in each group, being local and in bone in the treated group, and in lymph nodes, skin and lung in the control group. There were no toxic effects associated with coumarin treatment and all patients without recurrence are now receiving coumarin.

Adult↗
PubMed1988

[Primary non-Hodgkin's lymphoma of the muscles].

On the basis of two personal observations and of 18 published cases, a review of primary non-Hodgkin lymphoma originating in the skeletal muscle is presented. The disease mainly affects persons in the seventh decade. Ninety-five percent of the tumors occur in the extremities, with 75% in the lower extremities. Most lymphomas were of low grade malignancy, with intermediate and high grade tumors accounting for 45% of cases. Reliable differentiation of NHL from other small round cell tumors of the soft tissues, such as rhabdomyosarcoma or Ewing sarcoma, and from metastatic carcinoma, is mandatory for therapeutic purposes. Diagnosis can be established by light microscopy alone in most patients. In doubtful cases immunohistochemistry may be required.

Combined Modality Therapy↗