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Biomedical subjects

L J Ling

Publications and source records attributed to L J Ling.

At least 19 recordsLinked to original sources
PubMed2001

Association between betel quid chewing, periodontal status and periodontal pathogens.

The present investigation examined whether an association exists between betel quid chewing and signs of periodontal disease and determined the prevalence of Actinobacillus actinomycetemcomitans and Porphyromonas gingivalis by polymerase chain reaction. The periodontal status of 34 betel quid chewers and 32 non-betel quid chewers were compared. A significantly higher prevalence of bleeding on probing was found in betel quid chewers than non-chewers among the subjects with higher plaque level, greater gingival inflammation, deeper probing depth or greater attachment loss. Also, the results suggested that betel quid chewers may harbor higher levels of infection with A. actinomycetemcomitans and P. gingivalis than non-betel quid chewers. The association persists after adjusting for severity of the clinical parameters. In conclusion, betel quid chewing was associated with a higher prevalence of bleeding on probing where higher clinical levels of disease existed, and with a likelihood of subgingival infection with A. actinomycetemcomitans and P. gingivalis.

Actinobacillus Infections↗
PubMed2001

Why a new model?

Explore the source record for details and available documents.

Clinical Competence↗
PubMed2000

A new method for protein domain recognition.

A fuzzy cluster method is presented to recognize protein domains. This algorithm can identify domains globally. A protein structure set was used to test the algorithm. Among 219 proteins, 66.7% yielded results that agreed with the reference definitions, 30.6% showed minor differences, and only 2.7% (six proteins) showed major differences with the reference. The new method is more than 20 times fast than previous algorithms.

Cluster Analysis↗
PubMed2000

Effects of areca nut extracts on the functions of human neutrophils in vitro.

Aqueous extracts of ripe areca nut without husk (ripe ANE) and fresh and tender areca nut with husk (tender ANE) were examined for their effects on the defensive functions of human neutrophils. Exposure of peripheral blood neutrophils to ripe ANE and tender ANE inhibited their bactericidal activity against oral pathogens, including Actinobacillus actinomycetemcomitans and Streptococcus mutans, in a dose-dependent manner. At the concentrations tested, ripe and tender ANEs did not significantly affect the viability of neutrophils as verified by their ability to exclude trypan blue dye. However, both ANEs inhibited the production of bactericidal superoxide anion by neutrophils as measured by cytochrome c reduction. Moreover, the ripe ANE inhibited neutrophils more effectively than did tender ANE. Arecoline, a major alkaloid of areca nut, only exhibited an inhibitory effect on the functions of neutrophils when high concentrations were used. Therefore, arecoline could not be used to explain the inhibitory effects observed for ANEs. In conclusion, our results demonstrated that ripe and tender ANEs reduced the antibacterial activity and the superoxide anion production of neutrophils. This effect may contribute to a less efficient elimination of bacteria from the periodontal environment. Inhibition of the antimicrobial functions of neutrophils may alter the microbial ecology of the oral cavity, and this may be one possible mechanism by which areca nut compromises the oral health of users of areca nut products.

Aggregatibacter actinomycetemcomitans↗
PubMed2000

Guided tissue regeneration with and without demineralized freeze-dried bone allografts for maxillary Class II furca invasions of rapidly progressive periodontitis.

BACKGROUND: Guided tissue regeneration (GTR) using an expanded polytetrafluorethylene (ePTFE) membrane is an established treatment modality for periodontal disease. This study was designed to compare the effects of ePTFE membranes with and without demineralized, freeze-dried bone allografts (DFDBA) for treating maxillary class II buccal furca invasions of rapidly progressive periodonitis. METHODS: Seven patients with pairs of maxillary class II buccal furca invasions comprised the study group. The clinical parameters investigated were probing depth, probing attachment level and marginal tissue recession. One defect from each pair of teeth was randomly selected for the ePTFE membrane and DFDBA group and the other tooth defect received ePTFE membrane treatment only. During the operation, horizontal probing depths at the buccal furcation areas were measured. The membrane was removed 6 weeks after insertion. All measurements were repeated 1 year later at surgical re-entry of the buccal furcation. The Wilcoxon ranked sum test was used to test the significance of the difference between the groups 1 year after treatment. RESULTS: In the ePTFE membrane and DFDBA group, the mean probing depth reduction was 2.1 +/- 0.8 mm. The probing attachment gain was 2.6 +/- 1.0 mm and the bone fill was 3.1 +/- 1.7 mm. There was no statistically significant difference between the groups for these parameters. The marginal tissue recession was reduced 0.4 +/- 0.7 mm in ePTFE membrane and DFDBA group but increased 0.9 +/- 0.6 mm in ePTFE membrane only group. This difference was statistically significant (p = 0.016). CONCLUSIONS: There was no difference in probing depth reduction, probing attachment gain or bone fill between the two treatment modalities for treating maxillary class II buccal furca invasion of rapidly progressive periodontitis. Marginal tissue recession can be significantly reduced with the treatment of combined ePTFE membrane and DFDBA.

Adult↗
PubMed1999

Emergency center categorization standards.

The SAEM EC Categorization Task Force was developed in response to the 1994 Macy Foundation's recommendation that emergency medicine (EM) organizations "should revise the classification of emergency departments ... to reflect the level of care available in emergency departments, and indicate whether or not facilities are adequate and whether appropriately qualified and credentialed emergency physicians are available 24 hours a day." By holding Level 1 emergency centers (ECs) to objective standards based on the quality of care delivered as well as administrative, research, and educational efforts, SAEM hopes to improve patient care. The SAEM EC Categorization Task Force is now beginning the process of reviewing ECs that provide comprehensive emergency care and serve as regional resources for education, research, and administration in EM. This standards document describes relative and critical criteria to be met in order to receive designation as a Level 1 emergency center. Such centers must meet all critical criteria, and be in sufficient compliance with most or all relative criteria, in order to achieve this designation. This process is entirely voluntary. Any EC is eligible for review. Any institution can initiate the review process by applying. Application materials and further information, including the policies and procedures of the SAEM EC Categorization Task Force, are available from SAEM.

Education, Continuing↗
PubMed1998

Proceedings of the Future of Emergency Medicine Research Conference, Part I: Executive summary.

The five articles presented in this section were written by representatives of the emergency medicine research community during the "Future of Emergency Medicine Research Conference," March 6 and 7, 1997, in Washington DC. Each presentation was balanced with commentary by two conference participants from outside emergency medicine. The discussion of each presentation was opened to scrutiny and analysis by all the conference participants. The participants included representatives from governmental agencies and other clinical specialties with the experience and understanding of specialty research enhancement. The objectives and recommendations in this final summary are the result of considerable insight and discussion from all participants. The specialty of emergency medicine owes a special thanks to those from outside the specialty who volunteered their time and effort to share their wisdom with us. Although the 35 participants represent many points of view, not all potential viewpoints were included. Hence, there may be other actions that need to be taken by organizations and individuals to advance emergency medicine research. It is now the responsibility of each individual emergency physician to carefully consider his or her own role and commitment in the process of advancing emergency medicine research. Our collective will as academic departments and the organized emergency medicine community must reaffirm our belief in the importance of emergency medicine research. Individually and collectively, we will need to dedicate the necessary resources to implement the strategies suggested for enhancing emergency medicine research training extramural funding, national organization support, multicenter research, and new research outcomes.

Emergency Medicine↗
PubMed1998

Current concept of guided tissue regeneration with non-absorbable membrane.

Guided tissue regeneration has been well established as a treatment modality for periodontal disease. Proper case selection and delicate surgical skills can lead to the predictable success. Additionally, the GTR may also be used to treat marginal tissue recession, peri-implantitis, and palato-gingival grooves. Furthermore, osteopromotion with membrane techniques can be used as a means to provide ridge augmentation in ridge defects, or as an adjunct to implant placements. It does play a very important role in implant dentistry and aesthetic dentistry.

Bone Substitutes↗
PubMed1996

Research directions in emergency medicine.

The goal of emergency medicine is to improve health while preventing and treating disease and illness in patients seeking emergency medical care. Improvements in emergency medical care and the delivery of this care can be achieved through credible and meaningful research efforts. Improved delivery of emergency medical care through research requires careful planning and the wise use of limited resources. To achieve this goal, emergency medicine must provide appropriate training of young investigators and attract support for their work. Promotion of multidisciplinary research teams will help the specialty fulfill its goals. The result will be the improvement of emergency medical care which will benefit not only the patients emergency physicians serve but also, ultimately, the nation's health.

Emergency Medicine↗
PubMed1995

The effect of oral deferoxamine on iron absorption in humans.

Acute iron overdose is a serious cause of morbidity and mortality, however, optimal gastric decontamination procedures in iron overdose are unclear. In order to determine the effectiveness of oral deferoxamine mesylate solution in humans to prevent the absorption of iron in acute exposures, the following prospective case control crossover study was designed. Seven informed adult human volunteers were given an oral dose of 5 mg/kg elemental iron alone in a control phase and again in an experimental phase followed by a single equimolar dose of oral buffered deferoxamine solution. Plasma iron concentrations were determined spectrophotometrically for eight hours following administration of iron alone and following doses of iron with deferoxamine. There was no significant difference in peak iron concentration, time to peak iron concentration or area-under-the-curve between the two groups. Based on our results, equimolar doses of oral deferoxamine do not appear to decrease the absorption of low doses of oral iron in humans.

Administration, Oral↗
PubMed1994

Response of regenerative tissues to plaque: a histological study in monkeys.

This study was designed to determine the histologic response of regenerated tissue to plaque, using an adult Taiwan monkey model with chronically-inflamed, surgically-created, periodontal defects. Standardized 2-walled periodontal defects were surgically created at the mesial of the mandibular lateral incisor on one side. Sutures, 3-0 braided silk, were placed for 8 weeks and tissues positioned so that denuded root surfaces were exposed to plaque, with the subsequent development of the chronically-inflamed periodontal tissues. At 8 weeks the defects were subjected to guided tissue regeneration procedures using expanded polytetrafluoroethylene membrane and allowed to heal for 6 months. Contralateral clinically healthy sites, without surgical procedures, were used as controls. In both experimental (membrane) and control sites, silk ligatures were placed to allow plaque accumulation for 2 or 10 weeks. Four monkeys were sacrificed at each time point and specimens processed for histologic and histometric study. The results indicated that plaque-induced inflammation was less at sites treated by guided tissue regenerative procedures when compared to originally clinically-healthy sites exposed to plaque for the same duration. However, histologically the newly formed osseous tissue was compromised under these conditions.

Alveolar Bone Loss↗