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Biomedical subjects

F M Beck

Publications and source records attributed to F M Beck.

At least 37 records · Page 2Linked to original sources
PubMed1995

The effectiveness of a disposable tooth cleansing device on plaque.

A disposable polyester foam sponge on a stick, impregnated with a non-foaming dentifrice, has been widely dispensed to hospitalized and nursing home patients for intraoral cleansing and refreshing. Since no information was found relative to tooth cleansing capabilities, we have evaluated its effectiveness in the removal of accumulated plaque and also in prevention of plaque accumulation. Removal of 72 hours of accumulated plaque was assessed in a cross-over design study comparing the device with a commercially-available toothbrush by two different groups of 13 and 29 adult, healthy subjects who used each instrument for 1 and 3 minutes respectively. No significant differences were found between mean scores assessed by Turesky's modification of the Quigley-Hein plaque index by either group using either instrument at either time period (P > 0.05). Prevention of plaque accumulation was assessed in a third group of 25 subjects who used each instrument an average of 3 times a day for 1 week in a cross-over study. While the toothbrush was found significantly more effective in retarding the accumulation of plaque from a plaque-free baseline on both facial and lingual surfaces (P < 0.02), the tooth cleansing device still retained plaque-preventive capabilities by maintaining plaque formation below 2 mm at the cervical margin of the tooth. Results of this study indicate the tooth cleansing device may be a viable alternative to conventional toothbrushes.

Adult↗
PubMed1995

Polyamines found in gingival fluid inhibit chemotaxis by human polymorphonuclear leukocytes in vitro.

Putrescine and spermidine occur at concentrations approaching 1 mM in gingival fluid at diseased periodontal sites. Previous work demonstrates that these polyamines potentiate Ca2+ signaling in polymorphonuclear leukocytes (PMNs), resulting in enhanced degranulation and superoxide generation. The present study extends this work by characterizing the effects of polyamines on PMN chemotaxis and phagocytosis, in which Ca2+ signaling plays a less defined regulatory role. Putrescine (1 mM) and spermidine (0.1 to 0.5 mM) significantly inhibited chemotaxis to fMet-Leu-Phe and C5a (P < 0.05). This inhibition was not strongly related to any effect polyamines have on PMN adhesion, actin polymerization, or formyl peptide receptor expression. Neither putrescine nor spermidine had a significant impact on phagocytosis of opsonized bacteria by PMNs. Thus, at concentrations similar to those found in gingival fluid, polyamines could potentially inhibit recruitment of PMNs to diseased pockets without impairing their ability to engulf invading bacteria.

Analysis of Variance↗
PubMed1994

Stress-induced changes attributable to the sympathetic nervous system during experimental influenza viral infection in DBA/2 inbred mouse strain.

The murine model of influenza viral infection was used to evaluate the effects of restraint stress on pathogenesis and survival in the DBA/2 inbred strain of mice. Restraint stress has been associated with an enhanced probability of survival during influenza infection in this strain of mouse. Previous studies suggested that the protective mechanism(s) of stress on mortality might be attributable to elevated levels of circulating glucocorticoids. Subsequent work demonstrated that corticosterone levels alone could not account for the enhanced survival seen in the DBA/2 mice. The present studies examined the role of catecholamines in behavioral stress during influenza infection. It appears that glucocorticoids may play a primary role in trafficking and restriction of inflammation, while catecholamines may play role in limiting activation of virus-specific effector cells. The studies presented here suggest that the interplay between these two physiological response mechanisms needs to be coordinated to optimize development of the immune response to an infection.

Animals↗
PubMed1994

Kinetics of glucocorticoid response to restraint stress and/or experimental influenza viral infection in two inbred strains of mice.

The murine model of influenza viral infection was used to evaluate the effects of restraint stress on pathogenesis and survival in inbred strains of mice. We recently reported that restraint stress was associated with an enhanced probability of survival in one strain of inbred mouse, DBA/2, and not in another, C57BL/6. Those studies suggested that the protective mechanism(s) of stress on mortality in the DBA/2 mice might be attributable to elevated levels of circulating glucocorticoids. Therefore, daily levels of plasma glucocorticoids were measured during influenza viral infection in both these strains. The present studies demonstrated that influenza infection itself is perceived as a stressor in both C57BL/6 and DBA/2 mice as evidenced by elevated plasma glucocorticoid levels within 48 h of infection. However, augmentation of glucocorticoid levels was not seen in the DBA/2 mice that were also subjected to restraint stress during the course of infection. Thus, corticosterone levels alone did not account for the enhanced survival seen in this group of animals.

Animals↗
PubMed1994

Comparison of a lesion-inducing isolate and a non-lesional isolate of Candida albicans in an immunosuppressed rat model of oral candidiasis.

Two distinct strain-related patterns of organism-host interaction on dorsal tongue of immunocompetent rats have been identified for Candida albicans: some isolates induce mucosal lesions, while other isolates penetrate the keratin layer but do not produce a lesion. This study examined the behavior of each of the two types of isolates in a cyclosporin-immunosuppressed rat model. Groups B (normal) and D (cyclosporin) were orally inoculated with a lesion-inducing isolate of C. albicans, while a non-lesional isolate was given to Groups A (normal) and C (cyclosporin). A typical dorsal tongue lesion developed in 4/18 rats in Group B and in 13/16 in Group D (P = 0.00267). No significant difference in infection rate between the normal and cyclosporin-treated animals was seen for the non-lesional isolate. The lack of a host inflammatory response associated with the non-lesional isolate may represent an ecologic advantage for the organism.

Animals↗
PubMed1993

Restraint stress differentially affects the pathogenesis of an experimental influenza viral infection in three inbred strains of mice.

Genetic variation in the response to stress may play a critical role in susceptibility to inflammatory diseases and development of the immune response. Experimental influenza viral infection was used to study the effects of restraint stress (RST) on pathogenesis and development of the immune response. Three inbred strains of mice (C57BL/6, DBA/2, and C3H/HeN) were infected with influenza A/PR8 and subjected to repetitive cycles of RST during development of the immune response. RST diminished cellular immune and inflammatory responses in all three strains; yet only the DBA/2 strain demonstrated RST-associated reduction in influenza viral-induced mortality.

Animals↗
PubMed1993

Osteointegration of implants in radiated bone with and without adjunctive hyperbaric oxygen.

A study was undertaken to evaluate the integration of endosseous implants in rabbit tibias that had received a tumoricidal dose of radiation. The effect of hyperbaric oxygen on integration in this compromised situation was also evaluated. Despite clinical and radiographic evidence of success of all implants, there was a significant decrease in amount of histologic bony integration of implants placed in the tibias that had received radiation therapy when compared to contralateral control implants. Adjunctive hyperbaric oxygen therapy significantly improved the amount of histologic integration of implants placed within the radiated tibias evaluated at 10 and 16 weeks after placement. Hyperbaric oxygen was also associated with better soft tissue wound healing in the radiated surgical site. Increased integration time significantly improved the amount of histologic integration in the animals that did not receive hyperbaric oxygen.

Animals↗
PubMed1992

Retained "hopeless" teeth: lack of effect periodontally-treated teeth have on the proximal periodontium of adjacent teeth 8-years later.

We previously reported the lack of effect periodontally-treated teeth prognosed "hopeless" and retained for 3.4 +/- 1.5 years have on the proximal periodontium of adjacent teeth. We now report our findings for the same group of subjects following 8.4 +/- 0.7 years of "hopeless" tooth retention. Of the 17 "hopeless" and adjacent teeth originally measured in 17 subjects, 14 of the subjects were still available for re-evaluation. Measures used to assess the periodontium of proximal surfaces of adjacent teeth included pocket depths (PD), radiographic alveolar bone level (R-BL), and periodontal ligament space width (W-PL). Treatment for the subjects consisted of surgical therapy (N = 15) and scaling and root planing (N = 2). Of the 14 subjects re-examined, 2 were eliminated due to loss of adjacent tooth reference points and 2 due to extraction of the "hopeless" tooth (N = 10). Differences in measurements (i.e., nonadjacent to "hopeless" tooth value minus adjacent to "hopeless" tooth value) were analyzed using a repeated measures ANOVA. There were no significant differences for PD (P = 0.20), R-BL (P = 0.29), or W-PL (P = 0.16). These data confirm our original findings that retained periodontally "hopeless" teeth do not significantly affect the proximal periodontium of adjacent teeth following therapy.

Alveolar Bone Loss↗
PubMed1992

The relationship of gingival fluid leukocyte elastase activity to gingival fluid flow rate.

Recent studies have suggested that leukocyte elastase activity (EA) in tissue exudates is an indicator of inflammatory disease. We assayed gingival fluid (GF) EA with a selective peptide substrate and compared it to GF flow rate with regard to its ability to detect differences in the clinical status of existing inflammatory periodontal disease in 56 human subjects. Compared to healthy sites (Gingival Index = 0, 1 to 3 mm) and mild gingivitis sites (GI = 1, 2 to 5 mm), mean GF EA was significantly (P < 0.05) higher at periodontitis sites with deep probing depths (GI = 2, 6 to 9 mm depth), but not at periodontitis sites with intermediate probing depths (GI = 2, 4 to 5 mm). When expressed as specific EA (i.e., normalized to GF protein content), mean EA was also significantly higher at deep periodontitis sites compared to healthy sites and mild gingivitis sites. In addition, specific EA was significantly higher at periodontitis sites with intermediate probing depths than at healthy sites. As predicted by previous studies, these significant increases in specific EA were associated with significant increases in mean GF flow rate. In contrast to specific EA, however, mean GF flow rate was significantly higher at gingivitis sites than at healthy sites. A strong correlation was observed between GF flow rate and specific EA (rs = 0.737, P = 0.0006). Thus, GF flow rate and GF EA appear to be related indicators of inflammation, but GF flow rate may be more sensitive to early inflammatory changes leading to mild gingivitis.

Alveolar Bone Loss↗
PubMed1991

Image quality comparisons of X-Omat RP, L and B films.

The Eastman Kodak Company has recently developed a new film, X-Omat B (XB), designed to be interchangeable with X-Omat RP (XRP) film. The manufacturer claims the new film can be manually developed in half the time of other X-Omat films while automatic processing is unchanged. Three X-Omat film types were processed manually or automatically and the image qualities were evaluated. The XRP film had greater contrast than the XB and X-Omat L (XL) films when manually processed, and the XL film showed less contrast than the XB and XRP films when processed automatically. There was no difference in the subjective evaluation of the various film types and processing methods, and the XB film could be interchanged with XRP film in a simulated clinical situation.

Evaluation Studies as Topic↗
PubMed1990

Plaque score changes based primarily on patient performance at specific time intervals.

Patient plaque removal is a major component of periodontal therapy and should be continuously monitored during and following treatment. There do not appear to be studies which address plaque score changes achieved primarily by patient performance from the time of initial presentation to, during, and following active therapy. We assessed individual tooth surfaces and segment plaque scores for 24 adult subjects presenting with periodontitis, the majority of which was ADA case types III and IV, at 3 time points (initial presentation, post-initial preparation, and at 3 months following active therapy), using the O'Leary Plaque Index. The assessments describing surfaces and segments were made prior to any professional intervention. Analysis of buccal (B), interproximal (I), and lingual (L) plaque retentive surfaces at t-0 indicated the mean plaque index on B and L surfaces (30.7% and 41.9% respectively) was less than that on I surfaces (79.6%). At t-1 and t-2, the mean plaque index on all three surfaces was significantly (P less than 0.05) less than at t-0. Analysis of plaque indices in each of 6 segments at each time point revealed that plaque scores in all segments, except the mandibular right segment, were analogously reduced from t-0 to t-1 and to t-2. Our results indicate that plaque reduction for all subjects based primarily on patient performance consistently approaches or exceeds 50% on all surfaces and that interproximal surfaces present with and retain more plaque than buccal and lingual surfaces. Furthermore, patient plaque performance achieved at the time of post-initial preparation may be a predictor of the plaque control achievable during therapy based on patient performance.

Dental Plaque↗
PubMed1989

Relationship of human gingival crevicular fluid polyamine concentration to the percentage of spirochaetes in subgingival dental plaque.

This relationship was examined at 45 inflamed periodontitis sites in 28 patients. A statistically significant positive correlation between polyamine concentration and spirochaetes was observed overall (r = 0.551, p = 0.0001). Within subgroups of this population (n = 15 each), there was no such relationship among midly inflamed sites with 5-6 mm probing depths (r = 0.0003, p = 0.999), but significant relationships among moderately inflamed sites with 5-6 mm depths (r = 0.567, p = 0.027) and 7-11 mm depths (r = 0.639, p = 0.010). Thus polyamines may be involved in subgingival plaque homeostasis at moderately inflamed periodontal sites.

Dental Plaque↗
PubMed1989

Video enhancement of dental radiographic films.

A prototype video image display system, a real-time analog enhancer (RAE), was compared to conventional viewing conditions with the use of nonscreen dental films. When medium optical density films were evaluated, there was no significant difference in the number of radiographic details detected. Conventional viewing conditions allowed perception of more details when dark films were evaluated; however, the RAE unit allowed the perception of more details when light films were viewed.

Computer Systems↗
PubMed1989

Effect of periodontal dressings on human gingiva fibroblasts in vitro.

In vitro cytotoxicity studies of periodontal dressings have not generally produced a result consistent with in vivo observations. These prior in vitro studies have not used human intraoral cell lines. We tested the effects of two eugenol containing and two non-eugenol periodontal dressings on cultured human gingival fibroblasts (HGF) (ATCC #1292). Replicate HGF cultures grown in microtiter plates were exposed to stock, 1:4 and 1:16 dilutions of extracts made from each of the four periodontal dressings. The HGF cultures were pulse labelled with tritiated thymidine (3HTdR) after 24, 48, and 72 hours. Incorporations of the labelled thymidine were measured using liquid scintillation counting and expressed as counts per minute. The results showed that undiluted extracts from all four periodontal dressings totally inhibited 3HTdR uptake (P less than 0.05). The 1:4 dilution of eugenol dressings inhibited 3HTdR uptake significantly more than non-eugenol dressings (P less than 0.05). Interestingly, at 72 hours the 1:16 dilution of the non-eugenol dressings caused significantly increased 3HTdR uptake which was not observed with the eugenol dressings. The present results suggest that the use of a human fibroblastic cell line for testing the effects of periodontal dressings may provide information about the relative biological effects of these dressings. Using this cell line, we have found that eugenol dressings inhibit fibroblast proliferation to a greater extent than non-eugenol dressings.

Cell Line↗
PubMed1989

Cognitive style as related to emotional empathy.

This study examined relationships among two measures of FDI (the hidden figure test (HFT) and the portable rod and frame test (PRFT) and a measure of interpersonal sensitivity (the questionnaire measure of emotional empathy (QMEE] in a group of dental hygiene students. All measures were administered to 44 dental hygiene students and 42 students enrolled in an introductory psychology course. While the dental hygiene students were more field independent than a previously reported normative sample (t = 24.6 p less than 0.002), they were not characteristically different than a representative group of college students on any of the measures. For students enrolled in the psychology course, but not the dental hygiene students, the more field independent students were, the less empathic they appeared to be. These results do not entirely support previous research indicating that dental hygiene students typically are more field independent.

Adolescent↗
PubMed1988

The effectiveness of flurazepam as night sedation prior to the removal of third molars.

Anxiety prior to dental treatment is a well-recognized problem. Although oral sedation has been recommended the night before appointments to reduce this anxiety, there are no well-controlled studies to support this claim. The present double-blind cross-over study investigated the effect of 30 mg of flurazepam taken the night before the removal of impacted third molars. Preoperative anxiety, visuomotor performance and sleep patterns were investigated in 20 adult patients with similarly impacted third molars. While preoperative flurazepam led to a statistically significant improvement in sleep patterns, there was no reduction in pre-operative anxiety on the morning of surgery. In addition, the flurazepam-treated group demonstrated significantly impaired visuo-motor performance 60 min after intravenous sedation compared to this group where intravenous sedation was used only preceded by placebo. Patients had a significant preference for flurazepam over placebo as a night-time sedative.

Adult↗