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Biomedical subjects

I Magnusson

Publications and source records attributed to I Magnusson.

At least 37 records · Page 2Linked to original sources
PubMed1996

Refractory periodontitis or recurrence of disease.

Refractory periodontal disease is characterized by low plaque scores and low responsiveness to periodontal therapy. The patients often have a history of antibiotic therapy and therefore have a high incidence of resistance in the subgingival microflora. The above features are in contrast to adult chronic periodontal disease and recurrence of disease. The subgingival microflora of refractory disease may be either predominantly gram-positive with elevated levels of Streptococcus intermedius or may be gram negative and contain elevated levels of the classical periodontal pathogens. In some cases serum IgG antibodies against Porphyromonas gingivalis are elevated and seem to decrease after therapy. Smoking may be an important factor in refractory periodontal disease. Treatment with directed antibiotic therapy as an adjunct to scaling and root planing retards the progression of disease for a limited time. Many questions are still not answered and suggestions are made for future directions in research.

Adult↗
PubMed1996

Efficacy of quantitative digital subtraction radiography using radiographs exposed in a multicenter trial.

Digital subtraction radiography (DSR) has been shown to be a sensitive and specific method for the detection of small bony changes in periodontitis. The purpose of this study was to perform a multicenter validation of the DSR in human subjects. Seventeen subjects were enrolled at 3 centers. Feather-edged hydroxyapatite chips (approximately 1, 7 and 10 mg) were used to simulate osseous lesions. Bilateral radiographs were taken with and without chips. Geometry was standardized using a cephalostat and the order of radiographs was determined using a randomization plan. Radiographs were subtracted, lesions isolated, and quantified at a single center without knowledge of the randomization code or location of the chips used in each subject. The overall sensitivity and specificity in detecting 1 mg changes was 87.8% and 100%, respectively. Sensitivity and specificity in detecting 7 mg and 10 mg chips was 100%. A strong linear relationship between actual lesion mass and calculated mass was observed (R2 = 0.94, slope = 0.98, p < 0.0001). No significant differences were observed by center. These data indicate that the DSR is a valid technique for the assessment of alveolar bone changes in multicenter trials.

Adult↗
PubMed1996

A multi-center clinical trial of a new chairside test in distinguishing between diseased and healthy periodontal sites. II. Association between site type and test outcome before and after therapy.

The aim of the present study was to evaluate the association between the outcome of a chairside test measuring gingival crevicular fluid (GCF) levels of the enzyme aspartate aminotransferase (AST) and other clinical measures of disease including probing depth, severity of inflammation, and GCF flow before and after therapy. We studied 91 patients with moderate to severe periodontitis. Eight sites with probing depths between 5 mm and 8 mm and obvious signs of inflammation were selected and designated diseased sites. Four sites with probing depth < or = 3 mm with no or minimal signs of inflammation were selected and designated non-diseased sites in patients. Thirty healthy individuals were enrolled and four sites in each were selected and designated healthy controls. Patients were treated with scaling and root planing and control subjects with supragingival prophylaxis. Measurements including GCF volume, gingival inflammation, and probing depth were performed at screening baseline, 1 week later at pretreatment baseline, and at weeks 2 and 4 after treatment. AST content of GCF was measured using a chairside colorometric test. It was concluded that the outcome of the test is an effective objective measure distinguishing between diseased sites and non-diseased sites in patients and control subjects when evaluated both prior to and following application of therapy. Use of this simple chairside test, when combined with other standard diagnostic procedures, provides an objective measurement permitting improved capacity to distinguish between diseased and non-diseased periodontal sites, and to better assess and monitor the outcome of therapy.

Adult↗
PubMed1995

Alterations in the signal-transducing molecules of T cells and NK cells in colorectal tumor-infiltrating, gut mucosal and peripheral lymphocytes: correlation with the stage of the disease.

T cells from mice bearing an experimental colon carcinoma, and from patients with colorectal and renal carcinomas, have atypical T-cell receptors (TCR). In the present study, further characterization of modulations in CD3- and CD16-associated zeta chain in peripheral blood lymphocytes (PBL) and tumor-infiltrating lymphocytes (TIL) from colorectal carcinomas was performed. Relative to PBL, the percentage of natural killer (NK) cells among fresh TIL was reduced, while a higher proportion of T cells expressing HLA-DR was found. As previously reported, we found significantly reduced levels of the CD3- and CD16-associated zeta chain in TIL and, to a lesser extent, also in patients' PBL. Levels of zeta chain in T and NK cells from non-cancerous colorectal tissue from patients were lower than in PBL but higher than in TIL, with a direct relationship between levels of this signal-transducing molecule and the distance from the tumor. In addition, zeta levels correlated with the Dukes' stage of the disease, since PBL from patients with lymph-node involvement or distant organ metastases (Dukes' stages C and D) had significantly less CD3 zeta than patients with localized disease (stages A and B). Patients' T cells also had decreased levels of cell-surface and cytoplasmic CD3 epsilon. We also observed reduced levels of the TCR accessory molecules CD4 and CD8, mainly on TIL but to a lesser extent also on patients' PBL. Biochemical analysis of anti-CD3 epsilon-immunoprecipitated TCR complexes demonstrated that the CD3 complex was not associated with the zeta chain, either on TIL or on PBL or on lymphocytes from non-cancerous colon tissue, suggesting a defect in the assembly of the TCR complex. Following several days of in vitro culture with recombinant interleukin-2 and phytohemagglutinin, anti-CD3 or anti-CD2 monoclonal antibodies (MAbs), levels of CD3 zeta chain as well as of cell surface CD3 epsilon were normalized. Our findings suggest an abnormal expression as well as assembly of several different signal-transducing molecules of T cells and NK cells, which correlate with the stage of the disease in patients with colorectal carcinomas.

Adult↗
PubMed1995

Decreased muscle glucose transport/phosphorylation is an early defect in the pathogenesis of non-insulin-dependent diabetes mellitus.

Recent studies have demonstrated that reduced insulin-stimulated muscle glycogen synthesis is the major cause of insulin resistance in patients with non-insulin-dependent diabetes mellitus (NIDDM). This reduced rate has been assigned to a defect in either glucose transport or hexokinase activity. However it is unknown whether this is a primary or acquired defect in the pathogenesis of NIDDM. To examine this question, we measured the rate of muscle glycogen synthesis and the muscle glucose 6-phosphate (G6P) concentration using 13C and 31P NMR spectroscopy as well as oxidative and nonoxidative glucose metabolism in six lean, normoglycemic offspring of parents with NIDDM and seven age/weight-matched control subjects under hyperglycemic (approximately 11 mM)-hyperinsulinemic (approximately 480 pM) clamp conditions. The offspring of parents with NIDDM had a 50% reduction in total glucose metabolism, primarily due to a decrease in the nonoxidative component. The rate of muscle glycogen synthesis was reduced by 70% (P < 0.005) and muscle G6P concentration was reduced by 40% (P < 0.003), which suggests impaired muscle glucose transport/hexokinase activity. These changes were similar to those previously observed in subjects with fully developed NIDDM. When the control subjects were studied at similar insulin levels (approximately 440 pM) but euglycemic plasma glucose concentration (approximately 5 mM), both the rate of glycogen synthesis and the G6P concentration were reduced to values similar to the offspring of parents with NIDDM. We conclude that insulin-resistant offspring of parents with NIDDM have reduced nonoxidative glucose metabolism and muscle glycogen synthesis secondary to a defect in muscle glucose transport/hexokinase activity prior to the onset of overt hyperglycemia. The presence of this defect in these subjects suggests that it may be the primary factor in the pathogenesis of NIDDM.

Adenosine Diphosphate↗
PubMed1995

Different dose regimens of 5-fluorouracil and interferon-alpha in patients with metastatic colorectal carcinoma.

Three different 5-fluorouracil (5-FU)-interferon-alpha-2b (IFN)-containing regimens were designed for treatment of patients with advanced colorectal cancer. 87 patients with a Karnofsky index > or = 70 were included in three sequential non-randomised phase II trials. Regimen A consisted of 5-FU (750 mg/m2/day) given as a continuous infusion on days 1-5 followed by weekly 1-h intravenous infusions until week 8. IFN (5 MU) was given subcutaneously on days 1, 3 and 5 followed by injections (9 MU) every second day until week 8. The cycle was then repeated. Regimen B consisted of 5-FU (750 mg/m2/day) given as a continuous infusion on days 1-5 followed by 5-min intravenous injections on days 12 and 19. IFN (3 MU) was given subcutaneously on days 1-5 followed by injections (5 MU) on days 11-13 and 18-20. The cycle was repeated every fourth week. Regimen C consisted of 5-FU (750 mg/m2/day) given as a continuous infusion on days 1-5. IFN (3 MU) was given subcutaneously on days 1-5. The cycle was repeated every third week. The objective response rates (complete response (CR) and partial response (PR)) after approximately 4 months of therapy or longer were as follows: regimen A (n = 27) 22% (2 CR, 4 PR), regimen B (n = 33) 42% (4 CR, 10 PR) and regimen C (n = 27) 22% (1 CR, 5 PR). The corresponding response figures for previously untreated patients were regimen A 50%, regimen B 64% and regimen C 38%. Response durations varied from a few weeks up to 142 + weeks. Toxicities were generally mild and reversible, and the treatments were convenient for the patients and cost effective since the 5-day infusions could be given by a portable pump without hospitalisation. Our results are in agreement with those of others showing that 5-FU/IFN combinations can be highly effective in advanced colorectal cancer, and that a number of factors such as doses, dose intensities, infusion rates and timing of the two drugs may be crucial for the anti-tumour activity of this drug combination.

Adult↗
PubMed1995

Subcutaneous interleukin-2 and alpha-interferon in advanced colorectal carcinoma. A phase II study.

Subcutaneous administration of low doses of recombinant interleukin-2 (IL-2) and interferon-alpha (IFN-alpha) on an out-patient basis has been reported not to significantly compromise the response frequency compared to intravenous IL-2 in patients with renal cell carcinoma and melanoma. As part of an ongoing program to develop a biotherapeutic concept in patients with colorectal carcinoma (CRC) we studied the clinical effects of such a regimen in 15 patients with metastatic CRC. The daily dose of IL-2 varied between 4.8-14.4 x 10(6) U/m2 and of IFN-alpha between 3-6 x 10(6) U/m2. The cycle length was 6 weeks. The course was repeated every 8 weeks until disease progression. Maximum 4 cycles were administered. Maintenance therapy was given to responding patients once a week every month. No patient showed a major response (CR or PR). Six patients had a stable disease ranging from 3 months to 18 months with a median duration time of 5 months. The median survival of all patients was 13 months. The main adverse reactions were fever, chills, anorexia and shortness of breath. No treatment related deaths occurred. 6/14 patients developed abnormal concentration of serum levels of thyroid hormones. It is concluded that the present treatment schedule using IL-2 and IFN-alpha in advanced CRC seemed not to be of clinical benefit.

Adult↗
PubMed1995

Analysis of gamma delta V region usage in normal and diseased human intestinal biopsies and peripheral blood by polymerase chain reaction (PCR) and flow cytometry.

The intestinal population of gamma delta T cell receptor (TCR)-bearing cells was characterized with regard to V delta and V gamma subtype expression. For this purpose, we utilized V gene-specific PCR of mRNA prepared from intestinal biopsies. Predominant expression of the V delta 1 subtype was demonstrated in the small intestine of patients with coeliac disease and in the inflamed colon of patients with inflammatory bowel diseases (IBD: ulcerative colitis and Crohn's disease) as well as in colon biopsies taken from macroscopically normal areas of colon. Although intestinal gamma delta T cells preferentially expressed V delta 1, other V delta transcripts could be detected, of which V delta 2 and V delta 5 were commonly expressed. Analysis of biopsies from mesenteric lymph nodes demonstrated a V delta repertoire similar to the mucosa. In peripheral blood on the other hand, high expression of both V delta 2 and V delta 1 was found. The predominant expression of V delta 1 transcripts in the intestinal mucosa of IBD patients correlated well with protein cell surface expression as analysed by flow cytometry using V delta 1- and V delta 2-specific antibodies. Selective expansion of gamma delta T cells could not be demonstrated within the inflamed mucosa as shown by mRNA analysis and flow cytometry. Instead, IBD patients demonstrated a decreased proportion of TCR gamma delta-carrying T cells in the inflamed mucosa compared with macroscopically normal area of colon. On the other hand, a significantly increased percentage of T cells bearing the gamma delta TCR was found in peripheral blood of patients with Crohn's disease compared with healthy individuals, indicating that local mucosal inflammation may influence the circulating gamma delta T cell population.

Base Sequence↗
PubMed1995

A multicenter clinical trial of PerioGard in distinguishing between diseased and healthy periodontal sites. (I). Study design, methodology and therapeutic outcome.

We designed and performed a multicenter clinical trial to determine the relationship between measurements of the level of the enzyme aspartate aminotransferase (AST) in gingival crevicular fluid (GCF) to other measures used to detect periodontal disease and monitor outcome of treatment, including pocket depth and gingival inflammation. 32 periodontitis patients were enrolled at the University of Washington, Seattle, 30 at the University of Florida, Gainesville, and 34 at the University of Illinois, Chicago. 10 periodontally normal control subjects were enrolled at each location. 8 diseased and 4 healthy sites were designated for study in each patient and 8 healthy sites designated in each control subject. Measures of disease included pocket depth, severity of gingival inflammation, and GCF volume. AST levels were measured using the PerioGard test kit. Clinical measurements were made and GCF samples harvested and tested 2x before and 2x after therapy consisting of scaling and root planing under local anesthetic. Specific design and other issues are discussed, including selection of patients and control subjects, sample size, selection of experimental test sites, methods for assessment of diseased and therapeutic improvement, harvesting of GCF and selection of appropriate biostatistical methods for data analysis. Demographics of the patient populations at the 3 locations are reported. As expected, therapy induced only negligible changes in the measures of disease at healthy sites in control subjects, and relatively minor improvement in healthy sites in patients. In contrast, statistically significant improvement relative to pretreatment baseline status in all 3 measures of disease was observed for diseased sites at all 3 study locations with all p-values less than 0.0002. The magnitude of improvement was comparable to that reported previously by others. The % of PerioGard-positive sites decreased significantly between the screening baseline and both post-treatment visits for patients at all 3 locations, with p values of 0.0001 to <0.0008.

Adult↗
PubMed1995

Impaired net hepatic glycogen synthesis in insulin-dependent diabetic subjects during mixed meal ingestion. A 13C nuclear magnetic resonance spectroscopy study.

Hepatic glycogen concentration was measured in six subjects with insulin-dependent diabetes mellitus (IDDM) and nine weight-matched control subjects using 13C nuclear magnetic resonance spectroscopy during a day in which three isocaloric mixed meals were ingested. The relative fluxes of the direct and indirect (3 carbon units-->-->glycogen) pathways of hepatic glycogen synthesis were also assessed using [1-13C]glucose in combination with acetaminophen to noninvasively sample the hepatic UDP-glucose pool. Mean fasting hepatic glycogen content was similar in the two groups. After each meal, hepatic glycogen content increased, peaking 4-5 h after the meal in both groups. By 11:00 p.m. the IDDM subjects had synthesized only 30% of the glycogen that was synthesized by the control group [IDDM subjects, net increment = 44 +/- 20 (mean +/- SE) mM; control subjects, net increment = 144 +/- 14 mM; P < 0.05]. After breakfast the flux through the gluconeogenic pathway relative to the direct pathway of hepatic glycogen synthesis was 1.7-fold greater in the IDDM subjects (59 +/- 4%) than in the control subjects (35 +/- 4%, P < 0.0003). In conclusion, under mixed meal conditions, subjects with poorly controlled IDDM have a major defect in net hepatic glycogen synthesis and augmented hepatic gluconeogenesis. The former abnormality may result in an impaired glycemic response to counterregulatory hormones, whereas both abnormalities may contribute to postprandial hyperglycemia.

Adult↗
PubMed1995

Contribution of hepatic glycogenolysis to glucose production in humans in response to a physiological increase in plasma glucagon concentration.

The contribution of net hepatic glycogenolysis to overall glucose production during a physiological increment in the plasma glucagon concentration was measured in six healthy subjects (18-24 years, 68-105 kg) after an overnight fast. Glucagon (approximately 3 ng.kg-1.min-1), somatostatin (0.1 microgram.kg-1.min-1), and insulin (0.9 pmol.kg-1.min-1) were infused for 3 h. Liver glycogen concentration was measured at 15-min intervals during this period using 13C-labeled nuclear magnetic resonance spectroscopy, and liver volume was assessed from magnetic resonance images. The rate of net hepatic glycogenolysis was calculated from the decrease in liver glycogen concentration over time, multiplied by the liver volume. The rate of glucose appearance (Ra) was calculated from [3-3H]glucose turnover data using a two-compartment model of glucose kinetics. Plasma glucagon concentration rose from 136 +/- 18 to 304 +/- 57 ng/l and plasma glucose concentration rose from 5.6 +/- 0.1 to 10.4 +/- 0.9 mmol/l on initiation of the infusions. Mean baseline Ra was 11.8 +/- 0.4 mumol.kg-1.min-1, increased rapidly after the beginning of the infusions, reaching its highest value after 20-40 min, and returned to baseline by 140 min. Liver glycogen concentration decreased almost linearly (from 300 +/- 19 mmol/l liver at baseline to 192 +/- 20 mmol/l liver at t = 124 min) during 2 h after the beginning of the infusions, and the calculated mean rate of net hepatic glycogenolysis was 21.7 +/- 3.6 mumol.kg-1.min-1. Mean Ra during the same time period was 22.8 +/- 2.3 mumol.kg-1.min-1. Thus, net hepatic glycogenolysis accounted for 93 +/- 9% of Ra.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1994

Validation of 13C NMR measurements of liver glycogen in vivo.

The natural abundance 13C NMR intensity of the glycogen C1 resonance was measured in the surgically exposed liver of rabbits in vivo (n = 17) by integration from 98 to 104 ppm and compared double blindedly to the subsequent biochemical measurement. Coil loading was measured each time from a reference sphere at the coil center and the NMR intensity was normalized accordingly. For quantification, the normalized NMR intensity was calibrated using aqueous glycogen solutions ranging from 110 to 1100 mumol glucosyl units/g (n = 14). An in vivo range from 110 to 800 mumol glucosyl units/g wet weight was measured with a highly linear correlation with concentration (r = 0.85, P < 0.001). The in vivo NMR concentration was 0.95 +/- 0.05 (mean +/- standard error, n = 17) of the concomitant enzymatic measurement of glycogen content. We conclude that the 13C NMR signal of liver glycogen C1 is essentially 100% visible in vivo and that natural abundance 13C NMR spectroscopy can provide reliable noninvasive estimates of in vivo glycogen content over the physiological range of liver glycogen concentrations when using adequate localization and integration procedures.

Animals↗
PubMed1994

Treatment of subjects with refractory periodontal disease.

The aim of the present study was to evaluate the effect of non-surgical periodontal therapy with the adjunct of a selected antibiotic in subjects diagnosed with refractory periodontal disease. 21 subjects were selected for the study; all had a history of periodontal surgery, tetracycline therapy, and regular maintenance by a periodontist. When disease activity was detected, a bacterial sample was taken and a whole plaque susceptibility test was performed. Before the outcome of the susceptibility test the subjects were assigned to either antibiotic or placebo therapy. All subjects received scaling and rootplaning prior to antibiotic or placebo therapy. Based on the susceptibility test, subjects in the antibiotic group were treated either with Augmentin or clindamycin. The results demonstrated that in subjects with refractory periodontal disease there was no significant difference (N.S.) in the proportion of sites losing attachment before and after treatment (11.3% and 12.4%, respectively) over a 2-year post therapy observation period. However, the proportion of sites showing gain of attachment increased from 0.9% before therapy to 5.1% (p = 0.029) following selective antibiotic therapy when combined with scaling and rootplaning. The remainder of sites showed no change between pre- and post-therapy monitoring periods. The progression of attachment loss in the active sites could not be completely stopped over the entire 2-year period. After 12-15 months following therapy, there was a tendency towards new loss of attachment and an increase of pocket depth. However, all 4 subjects treated with placebo drug demonstrated continuous deterioration and had to be retreated. Although the proportion of sites losing attachment decreased from 5.1% to 2.3% (N.S.), the proportion of sites gaining attachment also decreased from 2.0% to 1.0% (N.S.). The results suggest that scaling and rootplaning together with selected antibiotic therapy repeated every 12-15 months may be beneficial for these subjects although it may not completely stop progressive attachment loss.

Adult↗
PubMed1994

Liver glycogen turnover in fed and fasted humans.

Whether liver glycogen synthesis and breakdown occur simultaneously during net glycogen synthesis was assessed in fed and fasted healthy humans. The peak intensity of the carbon-1 (C1) resonance of the glycosyl units of glycogen was monitored with 13C nuclear magnetic resonance spectroscopy during [1-13C]glucose infusion followed by unlabeled glucose infusion. The C1 peak intensity increased almost linearly during the [1-13C]glucose infusion, reflecting a near linear rate of glycogen synthesis. When switched to unlabeled glucose, the C1 peak intensity reached a plateau in the fasted subjects and declined in the fed subjects, reflecting active glycogenolysis during a time of net glycogen synthesis. We conclude that liver glycogen synthesis and degradation occur simultaneously in humans under conditions of net glycogen synthesis. The relative turnover rate was significantly higher in the fed (57 +/- 3%) than in the fasted state (31 +/- 8%; P < 0.01). The results indicate that glycogen may regulate its rate of breakdown and that liver glycogen turnover may be an important factor in limiting the accumulation of liver glycogen in humans.

Adult↗
PubMed1994

13C-nuclear magnetic resonance spectroscopy studies of hepatic glucose metabolism in normal subjects and subjects with insulin-dependent diabetes mellitus.

To determine the effect of insulin-dependent diabetes mellitus (IDDM) on rates and pathways of hepatic glycogen synthesis, as well as flux through hepatic pyruvate dehydrogenase, we used 13C-nuclear magnetic resonance spectroscopy to monitor the peak intensity of the C1 resonance of the glucosyl units of hepatic glycogen, in combination with acetaminophen to sample the hepatic UDP-glucose pool and phenylacetate to sample the hepatic glutamine pool, during a hyperglycemic-hyperinsulinemic clamp using [1-13C]-glucose. Five subjects with poorly controlled IDDM and six age-weight-matched control subjects were clamped at a mean plasma glucose concentration of approximately 9 mM and mean plasma insulin concentrations approximately 400 pM for 5 h. Rates of hepatic glycogen synthesis were similar in both groups (approximately 0.43 +/- 0.09 mumol/ml liver min). However, flux through the indirect pathway of glycogen synthesis (3 carbon units-->-->glycogen) was increased by approximately 50% (P < 0.05), whereas the relative contribution of pyruvate oxidation to TCA cycle flux was decreased by approximately 30% (P < 0.05) in the IDDM subjects compared to the control subjects. These studies demonstrate that patients with poorly controlled insulin-dependent diabetes mellitus have augmented hepatic gluconeogenesis and relative decreased rates of hepatic pyruvate oxidation. These abnormalities are not immediately reversed by normalizing intraportal concentrations of glucose, insulin, and glucagon and may contribute to postprandial hyperglycemia.

Acetaminophen↗
PubMed1994

Modeling the relationship between clinical, microbiologic, and immunologic parameters and alveolar bone levels in an elderly population.

A cross-sectional periodontal study of 74 subjects aged 65 to 75 years was performed. Clinical data were collected and related to microbiological and immunological data. A statistical model (step-wise multiple regression) of factors related to bone loss was created initially using clinical data only; then by adding either the microbiologic or immunologic data; and then by using clinical, microbiologic, and immunologic data together. When only clinical data were considered, three factors were found to have significant positive correlations with bone loss. Tooth mobility accounted for 17% of the variability in the alveolar bone level measurements, probing depth for 12%(r2), and plaque index for 3%, for a total of 32% of the variability explained by these clinical factors. Tooth mobility and probing depth were clinical factors which remained significant in the model when the microbiological data were also considered. As percentages of the total cultivable microbiota, E. corrodens (r2 = 14%) and black-pigmenting Prevotella intermedia (r2 = 4%) correlated positively with alveolar bone loss. The addition of the microbiologic data only increased the r2 to 33%. When immunological data were considered with the clinical data, pocket depth and tooth mobility were the clinical parameters which remained in the model. IgG antibody levels to P. gingivalis W83 and/or 381 (r2 = 24%) A. actinomycetemcomitans 627 (r2 = 2%) were the significant immunologic measures having a positive correlation with bone loss. Anti-F. nucleatum levels had a significant negative correlation. A total of 50% of the variability in alveolar bone level was accounted for in the model by the addition of specific serum antibody levels to subgingival plaque microorganisms. When clinical, microbiological, and immunological measurements were all considered together, antibody to P. gingivalis W83 and/or 381 (r2 = 42%), percentage of B-lymphocytes (r2 = 3%), probing depth (r2 = 4%), anti-E. corrodens levels (r2 = 2%), and anti-P. gingivalis 33277 levels (r2 = 4%) all had significant positive correlation with loss of alveolar bone. The number of enteric bacteria, anti-F. nucleatum levels, and anti-P. intermedia levels each had a significant negative correlation with alveolar bone heights. The r2 for this model was 75%. These results indicated that antibody levels to subgingival plaque microorganisms and tooth mobility were the best predictors of bone loss in the elderly patients tested in this study.

Age Factors↗
PubMed1994

Effects of tetracycline-containing gel and a mixture of tetracycline and citric acid-containing gel on non-surgical periodontal therapy.

The purpose of this study was to assess the clinical and microbiological effects of a newly developed root conditioning gel system containing tetracycline or a mixture of tetracycline and citric acid on non-surgical periodontal therapy. Sixty-four (64) single-rooted teeth with a probing depth of 4 to 6 mm were randomly subjected to one of the following four treatments; 1) root planing alone (RP group); 2) tetracycline-containing gel alone (TCG group); 3) root planing plus tetracycline-containing gel (RP + TCG group); or 4) root planing plus a mixture of tetracycline and citric acid-containing gel (RP + TC-CAG group). Probing depth, attachment level, and tooth mobility were measured and the presence of dental plaque and gingival inflammation was recorded at baseline and after 2, 4, 8, and 12 weeks. Subgingival plaque samples from each site were collected at the same visits and examined with phase contrast microscopy for proportions of motile rods and spirochetes. Plaque index, gingival sulcus bleeding index (SBI), probing depth, and attachment level decreased significantly in all groups compared to the baseline values (P < 0.05). A significant decrease in probing pocket depth was noted after 12 weeks in RP + TC-CAG group compared to the other groups (P < 0.05). Significantly more gain in attachment was detected in the RP + TC-CAG group compared to the TCG group (P < 0.05). Tooth mobility scores also decreased later in the study. A significant decrease in the proportion of motile rods was found primarily in the RP + TC-CAG group.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗