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PubMed1999

Change in lifestyle factors and their influence on health status and all-cause mortality.

BACKGROUND: The purpose of this study was to analyse both cross-sectional associations and how longitudinal changes in lifestyle factors from one state in 1980-1981 to another in 1988-1989 influence self-reported health status. Another aim was to estimate the hazard ratios for all-cause mortality for the changes in lifestyle factors and self-reported hypertension during the same period of time. METHOD: The cross-sectional and the longitudinal analyses are based on the same simple random sample of 3,843 adults, aged 25-74, interviewed in 1980-1981 and 1988-1989 and is part of the Swedish Annual Level-of-Living Survey. About 85% of the respondents in the first interview participated in a second interview in 1988-1989. Cross-sectional odds ratios, based on a marginal model, were estimated using the generalized estimating equations. The transitional models were analysed using unconditional logistic regression. A proportional hazard model was applied to investigate the influence of lifestyle transitions on mortality. RESULTS: Physical inactivity, being a current or former smoker and obesity (women only) were strong risk factors for poor health either as main effects and/or combined (interactions). There was a strong interaction between physical activity and smoking, and for women, also between body mass index (BMI) and physical activity. Smoking, physically inactive and obese women had about a ten times higher risk of poor health status than non-smoking, physically active, and normal-weight women. The corresponding risk for men was about five times higher. Physically active, but smoking and obese individuals showed only moderately increased risks for poor health status. The transitional model showed that those who were physically inactive in 1980-1981, but did exercise in 1988-1989, improved their health after adjustments for sociodemographic and other lifestyle factors. Continuing to smoke or being physically inactive or having hypertension at both points in time were all associated with higher hazard ratios for all-cause mortality (1.6, 1.9 and 1.8, respectively) than those who reported that they were in good status at both points in time. CONCLUSIONS: We found that physical activity protects against poor health irrespective of an increased BMI and smoking. The major clinical implications are the long-standing benefits of physical activity and not smoking.

Adult↗
PubMed2003

Changes in sexual behavior and fecal steroid hormone concentrations during the breeding season in female Hokkaido brown bears (Ursus arctos yesoensis) under captive condition.

The longitudinal changes in fecal steroid hormone concentrations and sexual behavior in 2 mated/pregnant and 3 non-mated female Hokkaido brown bears were investigated during the breeding season. Behavioral estrus (standing) lasted for 14 and 32 days in the mated females and for 25 to 36 days in the non-mated females. In non-mated females, sexual behavior, such as female-female mounting and masturbation, was observed for several days before and after the estrous period. In mated females, mean fecal estradiol-17beta concentrations were higher in the estrous period than in the post-estrous period, while fecal progesterone concentrations were higher in the post-estrous period than in the estrous period. The similar trends of steroid hormone changes were observed in the non-mated females.

Animals↗
PubMed2005

Analysis of changes in gingival contour from three-dimensional co-ordinate data in subjects with drug-induced gingival overgrowth.

OBJECTIVES: This aim of this study was to develop and assess a technique that could be used to assess accurately the gingival volume changes seen in drug-induced gingival overgrowth by the analysis of data obtained from an entire gingival surface by means of three-dimensional imaging. MATERIAL AND METHODS: Stone dental models of patients before and after gingivectomy procedures were digitized with a laser scanner and then regenerated as computer models constructed from the acquired three-dimensional co-ordinate data. A comparison of superposed "before" and "after" surfaces was undertaken to assess and accurately quantify changes in gingival contour. RESULTS: The mean vertical tissue reduction varied from 1.58 to 2.56 mm in the four study subjects and individual differences are shown. The maximum thickness of removed buccal gingival overgrowth was found to range between 1.20 and 3.40 mm. The volume of tissue removed from each inter-dental papilla ranged from 4.2 to 46.1 mm3 and the mean volume of the papilla removed from each subject+/-SD values was 24.8+/-13.1 mm3. CONCLUSION: This method will measure changes in gingival tissues to within 60 microm in one plane, making it ideal for the assessment of longitudinal changes in gingival contour as seen in the development of gingival overgrowth, its recurrence after surgery or the changes in volume brought about by surgery.

Gingiva↗
PubMedDate not supplied

Changes in water transport across the peritoneum during treatment with continuous ambulatory peritoneal dialysis in selected patients with and without peritonitis.

BACKGROUND: The natural course of longitudinal changes in peritoneal permeability and membrane area has been studied mostly by performing single-dwell studies in selected patients during treatment with peritoneal dialysis. PURPOSE: To evaluate the permeability characteristics of the peritoneal membrane by measuring drained ultrafiltration volume relative to initial glucose concentration in dialysis fluid from the start to the end of continuous ambulatory peritoneal dialysis (CAPD) treatment in a selected cohort of patients with and without peritonitis. DESIGN: A retrospective analysis of a group of patients whose peritoneal function was prospectively followed by recording drained ultrafiltration volume and glucose concentration in dialysis fluid for each dwell time, every day, during the time in CAPD treatment. Mean values from a 1-month period starting after the first 3 weeks of CAPD treatment were compared with the mean values from the last month of treatment. Approximately 11 500 exchanges were analyzed. Evaluations were done separately for short (day) and long (night) dwell times. PATIENTS AND STATISTICS: Of 132 patients commencing CAPD treatment in the time period selected for inclusion, 51 had enough data to be included in this study. Of these, 29 patients experienced one or more episodes of successfully treated peritonitis. The selection of patients was not based upon patient characteristics, but upon criteria to satisfy predefined demands, such as number of measurements in each period, time since an episode of peritonitis, and time on CAPD treatment. Data were analyzed in three different groups: patients with episodes of peritonitis, patients without peritonitis, and both groups together. To assess changes between monthly mean at the start and at the end of CAPD, paired t-test was performed. Patients were also stratified into two groups according to low and high glucose in dialysis fluid at the start of CAPD (cutoff = 2 g/dL). Additionally, we used linear regression analyses to predict the level of drained ultrafiltration volume for a given level and change in glucose concentration. Mean treatment time for the entire group was 20 months (median 14.3 months), ranging from 6 to 69 months. RESULTS: No statistical differences in glucose concentrations were found between the periods compared. In the entire group there was an increase in ultrafiltration volume from the start to the end of CAPD treatment, for both day (p = 0.009) and night (p = 0.013) exchanges. Also, for patients without peritonitis, an increase appeared for day (p = 0.046) and night exchanges (p = 0.053). However, for the cohort with peritonitis, only an insignificant increase was indicated. Patient characteristics, diabetic patients, the need for glucose in dialysis fluid when commencing CAPD treatment, the number of episodes of peritonitis, and time on CAPD did not influence the change in ultrafiltration. Regression analyses showed higher ultrafiltration response to a given level and change in glucose concentration at the end of CAPD treatment compared to the start values, also for the cohort with peritonitis. The regression coefficient between these variables was also significantly changed for both day (p < 0.0001) and night (p = 0.027) exchanges. CONCLUSION: A significant change in the regression coefficient between glucose in dialysis fluid and ultrafiltration volume reflects an increase in ultrafiltration response to a given level and change in glucose concentration during time on CAPD treatment. A parallel change after 5- and 9-hour dwells can be explained by a decrease in peritoneal surface area combined with a lesser decrease in peritoneal conductivity. However, changes in Starling forces across the peritoneal membrane are possible even in the absence of changes in peritoneal membrane characteristics.

Biological Transport↗
PubMed2006

Changes in haemoglobin levels according to changes in body mass index and smoking habits, a 20-year follow-up of a male cohort: the Tromsø Study 1974-1995.

Haemoglobin level declines with increasing age in cross sectional studies. Little is known about the longitudinal changes of haemoglobin. Because both high or low haemoglobin levels increase mortality and morbidity we examined how changes in lifestyle factors like body mass index (BMI) and smoking habits influence cohort changes in haemoglobin level. In all, 4159 men aged 20-49 years at baseline were examined in 1974 and 1994-1995 in a longitudinal, population-based study from the municipality of Tromsø, Northern Norway. Mean haemoglobin was 148 g/l. There was no difference in mean haemoglobin after 20 years in any strata of age. Mean BMI increased 2.1 kg/m(2). The prevalence of smokers decreased 20.1 percentage points. In a multiple regression analysis increase in BMI was associated with increased haemoglobin change. Smoking cessation lowered mean haemoglobin 1.6 g/l compared to never smokers. Haemoglobin increased 0.8 g/l in smoking quitters whose BMI increased >2.5 kg/m(2) compared to a decrease of 6.7 g/l in weight reducers. There was a positive dose-response relationship between changes in cigarettes smoked per day and change in haemoglobin among consistent smokers. In conclusion, in contrast to cross sectional studies, mean haemoglobin did not change during 20 years ageing of relatively young men. This could be explained by higher BMI and less smoking. The increase in BMI affected haemoglobin change to such an extent that the reduction in haemoglobin due to smoking cessation was counteracted. Prospective studies are needed to address the health implications.

Adult↗
PubMed1999

Cross-sectional and 4-year longitudinal associations between brachial pulse pressure and common carotid intima-media thickness in a general population. The EVA study.

BACKGROUND AND PURPOSE: The cross-sectional and 4-year longitudinal associations between brachial pulse pressure (PP) and ultrasound measurements of common carotid intima-media thickness (CCA-IMT) were assessed. METHODS: A population of 957 volunteers aged 59 to 71 years was recruited from the electoral rolls of the city of Nantes (western France) and reexamined 4 years later. Longitudinal changes in PP and CCA-IMT were computed as the difference between 4-year follow-up and baseline values. RESULTS: Baseline CCA-IMT and PP were positively associated in both age- and sex-adjusted analysis (partial correlation coefficient=0.20, P<0.001) and in multivariate analysis adjusted for traditional cardiovascular risk factors and mean blood pressure (partial correlation coefficient=0.18, P<0.001). In longitudinal analysis, baseline PP was associated with the change in 4-year CCA-IMT (partial correlation coefficient=0.11, P<0.001), and baseline CCA-IMT was a predictor of the 4-year change in PP (partial correlation coefficient=0.10, 0.001<P<0.01). No association between mean blood pressure and CCA-IMT was observed once PP was taken into account, in either cross-sectional or longitudinal analyses (partial correlation coefficients ranged from 0.00 to 0.03). Similar patterns of results were observed in hypertensive, nonhypertensive, and antihypertensive-treated and -nontreated subjects. CONCLUSIONS: This longitudinal study of a large population of relatively aged subjects suggests that elevated levels of PP are associated with the progression of CCA-IMT, and increased CCA-IMT is associated with PP widening. The nature of these relationships and whether atherosclerosis progression over time is involved or not in these associations merit further investigations.

Aged↗
PubMed2000

Informant ratings of cognitive decline in old age: validation against change on cognitive tests over 7 to 8 years.

BACKGROUND: Informant questionnaires on cognitive decline are increasingly used as screening tests for dementia. Informants can provide a longitudinal perspective that is not possible with cognitive screening tests administered at one point in time. However, there are limited data on the validity of such questionnaires when judged against longitudinal change on cognitive tests. METHODS: A community sample of elderly people aged > or = 70 was assessed on cognitive tests at baseline and after a follow-up of 7-8 years. The participants were given the Mini-Mental State Examination and tests of episodic memory and mental speed. At follow-up, the short-form of the Informant Questionnaire on Cognitive Decline in the Elderly (IQCODE) was completed by informants for 287 of the participants. RESULTS: Elderly people who were rated by informants as having moderate or severe decline had declined significantly on cognitive tests. The IQCODE correlated as highly with cognitive test change scores as these change scores correlated with each other. CONCLUSIONS: The IQCODE is a valid way of assessing cognitive decline when assessment can be carried out only at one point in time.

Age Factors↗
PubMed2006

Changes in ocular physiology, tear film characteristics, and symptomatology with 18 months silicone hydrogel contact lens wear.

PURPOSE: The purpose of this study was to evaluate the longitudinal changes in ocular physiology, tear film characteristics, and symptomatology experienced by neophyte silicone hydrogel (SiH) contact lens wearers in a daily-wear compared with a continuous-wear modality and with the different commercially available lenses over an 18-month period. METHODS: Forty-five neophyte subjects were enrolled in the study and randomly assigned to wear one of two SiH materials: lotrafilcon A or balafilcon A lenses on either a daily- (LDW; BDW) or continuous-wear (LCW; BCW) basis. Additionally, a group of noncontact lens-wearing subjects (control group) was also recruited and followed over the same study period. Objective and subjective grading of ocular physiology were carried out together with tear meniscus height (TMH) and noninvasive tear breakup time (NITBUT). Subjects also subjectively rated symptoms and judgments with lens wear. After initial screening, subsequent measurements were taken after 1, 3, 6, 12, and 18 months. RESULTS: Subjective and objective grading of ocular physiology revealed a small increase in bulbar, limbal, and palpebral hyperemia as well as corneal staining over time with both lens materials and regimes of wear (p < 0.05). No significant changes in NITBUT or TMH were found (p > 0.05). Subjective symptoms and judgment were not material- or modality-specific. CONCLUSIONS: Daily and continuous wear of SiH contact lenses induced small but statistically significant changes in ocular physiology and symptomatology. Clinical measures of tear film characteristics were unaffected by lens wear. Both materials and regimes of wear showed similar clinical performance. Long-term SiH contact lens wear is shown to be a successful option for patients.

Adolescent↗
PubMed1992

Compositional changes in vertebral bone marrow during treatment for acute leukemia: assessment with quantitative chemical shift imaging.

A modified Dixon chemical shift imaging technique was used to quantify longitudinal changes in bone marrow that occur during induction chemotherapy in patients with acute leukemia. Results were correlated with those of bone marrow biopsy. Forty-seven quantitative images were obtained with a 0.6-T whole body imager in a total of 11 patients over the course of treatment. Quantitative measures of fat fractions and water and fat component T1 and T2 relaxation times were determined, as well as average relaxation times. Imaging results showed sequential increases in fat fractions among responding patients (n = 9), consistent with biopsy-confirmed clinical remission. In the two patients who later relapsed, sharp decreases in fat fractions were noted. In the two patients who failed to regenerate normal marrow, unchanging, low fat fractions were seen. Water component T1 values reflected posttherapeutic changes in the hematopoietic elements. Quantitative chemical shift imaging proved useful in assessing treatment response in acute leukemia during early bone marrow regeneration and, later, in ascertaining remission or relapse.

Adult↗
PubMed1995

Combined effects of blood pressure and body mass index on left ventricular structure in middle-aged males: cross-sectional and 2-year longitudinal results.

OBJECTIVE: To compare the 2-year longitudinal with the cross-sectional relationships of blood pressure and body mass index with echocardiographic left ventricular measurements in middle-aged males with no history of cardiovascular disease or hypertension. METHODS: M-mode echocardiograms of adequate quality were obtained at initial and 2-year follow-up examinations in 177 subjects. Measurements of left ventricular wall thickness and internal dimensions were made, and estimates of left ventricular mass/height were calculated. Longitudinal changes in left ventricular measurements and risk factors were computed as the differences between the follow-up and initial values. RESULTS: Systolic blood pressure (SBP) was significantly associated with left ventricular mass/height and wall thickness in cross-sectional and in longitudinal analyses. Similar results were observed after adjusting for age, body mass index, sport activity and heart rate. Although body mass index was strongly related to left ventricular mass/height, wall thickness and internal dimension in the cross-sectional study, no significant associations were observed between changes in body mass index and in left ventricular measurements. CONCLUSIONS: The present study emphasizes the differential effects of spontaneous changes in blood pressure and body mass index on the evolution of the left ventricular mass in middle-aged males. Spontaneous changes in SBP during the 2-year follow-up period were associated with rapid changes in left ventricular structure. The 2-year period might not have been sufficient for body mass index to induce changes in left ventricular structure. The duration and amplitude of body weight changes which entail changes in left ventricular mass remain to be determined by further longitudinal investigations.

Blood Pressure↗
PubMed2004

Impact of detraining on bone loss in former collegiate female gymnasts.

Undesirable changes in health-related parameters are thought to occur in retiring female athletes, but this has not been examined in longitudinal studies. The purpose of this study was to examine longitudinal changes in bone mineral density (BMD), body composition, and dietary intake in gymnasts and controls. Nonathletic, college-age women (: n = 9) were selected as a control group for comparison to the gymnasts (n = 10). Initial BMDs for the gymnasts were determined by using dual energy X-ray absorptiometry (Lunar, DPX) at the beginning of their final competitive year. Initial BMDs for the controls were measured during a similar time-frame. Follow-up measurements were made at least 1-year after the initial measurement. Gymnasts had significantly greater BMD of the femoral neck (1.262 versus 1.058 g/cm2, respectively), Ward's triangle (1.230 versus 1.008 g/cm2), greater trochanter (1002 versus 0.822 g/cm2), and total body (1.232 versus 1.145 g/cm2) than controls while still competing (P < .05). Following retirement from competition, (mean years of retirement, 4 years), BMD of the gymnasts remained significantly greater than controls at total body, femoral neck, trochanter, and Ward's triangle (P < .05). Significant declines in femoral neck, Ward's triangle, and greater trochanter BMD were found in both gymnasts and controls (0.72% to 1.9% per year), but only gymnasts had a significant decline at the lumbar spine (0.87% per year). In conclusion, BMD changes in former gymnasts appear to be site-specific, and gymnasts continue to have greater proximal femur BMD than controls, despite their decreased exercise, which may help postpone or prevent osteoporosis later in life.

Absorptiometry, Photon↗
PubMed2004

Reduction of anxiety after restricted feeding in the rat: implication for eating disorders.

BACKGROUND: Eating-disorder patients exhibit not only abnormal eating attitudes but also pathologic anxiety-like behaviors. The specific nature of the relationship between dieting and anxiety-like behavior is unknown. METHODS: To investigate the adaptational changes that resulted from chronic restricted scheduled feeding (2-hour access per day for 2 weeks) and subsequent free refeeding, longitudinal changes in the microstructure of feeding behavior were studied in male rats. To study the relationship between restricted feeding and anxiety-like behavior, separate rats were tested in the elevated plus-maze under the following conditions: 1) free feeding; 2) acute food restriction (2-hour access for 1 day); 3) chronic food restriction (for 10 days); or 4) postrecovery (after 10 days of free feeding subsequent to chronic food restriction). RESULTS: The effects of chronic food restriction on meal structure diminished within a few days after refeeding. Decreased anxiety-like behavior was seen during acute and chronic food restriction and did not reflect nonspecific behavioral activation. Anxiolytic-like effects persisted after 10 days of refeeding. CONCLUSIONS: Chronic food restriction produced reductions in anxiety-like behavior that persisted beyond the normalization of food intake patterns. The findings might have etiologic and pathophysiologic relevance for the restrained eating pattern in eating-disorder patients with comorbid anxious symptoms.

Adaptation, Psychological↗
PubMed2006

Pilot study of the impact of letrozole vs. placebo on breast density in women completing 5 years of tamoxifen.

Breast density, a strong risk factor for breast cancer, is reduced by the anti-estrogen, tamoxifen (TAM). We examined whether aromatase inhibitor (AI) therapy results in further reductions in breast density among women completing 5 years of TAM. Among a sample of women with early-onset breast cancer who were randomized to letrozole (LET)(n=56) or placebo (PLAC)(n=48) after 5 years of TAM, we examine the change in percent density at 9-15 months as well as a per-year change in PD by treatment group. There was no difference in the adjusted mean change (-1.0%, LET; -0.3%, PLAC (P=0.58)) or the percentage change (-2.7%, LET; -3.0%, PLAC (P=0.96)) in PD between treatment groups at 9-15 months. Results were similar for longitudinal change (-0.68% per year, LET; -0.12% per year, PLAC (P=0.23)). Breast density does not appear to be a clinically relevant biomarker in women who already have low PD following 5 years of TAM.

Adult↗
PubMed1998

Removing the 'estimates and guesses' from practice--evidence based tissue viability.

The development of evidence based tissue viability is reviewed using the prevention and management of pressure sores as a specific example. Although data is limited, pressure sores may be more common at the end of the 1990's than they were fifteen years ago, despite changes in clinical practice. If evidence based tissue viability is to grow and mature, then two key obstacles must be overcome; changes in patient populations must be reflected within prevalence or incidence data (case-mix adjustment) so allowing interpretation of longitudinal changes in the occurrence of sores. Secondly, the efficacy and effectiveness of interventions such as pressure-redistributing beds and mattresses must be identified through rigorous and appropriate methodologies. Only through such steps can clinical skill be blended with research evidence to fully realise evidence based practice.

Beds↗
PubMed1996

Advanced imaging methods.

Recent developments in imaging sciences have enabled dental researchers to visualize structural and biophysical changes effectively. New approaches for intra-oral radiography allow investigators to conduct densitometric assessments of dento-alveolar structures. Longitudinal changes in alveolar bone can be studied by computer-assisted image analysis programs. These techniques have been applied to dimensional analysis of the alveolar crest, detection of gain or loss of alveolar bone density, peri-implant bone healing, and caries detection. Dental applications of computed tomography (CT) include the detailed radiologic anatomy of alveolar processes, orofacial soft tissues and air spaces, and developmental defects. Image analysis software permits bone mass mineralization to be quantified by means of CT data. CT has also been used to study salivary gland disease, injuries of the facial skeleton, and dental implant treatment planning. Magnetic resonance imaging (MRI) has been used extensively in retrospective and prospective studies of internal derangements of the temporomandibular joint. Assessments based on MRI imaging of the salivary glands, paranasal sinuses, and cerebrovascular disease have also been reported. Magnetic resonance spectroscopy (MRS) has been applied to the study of skeletal muscle, tumors, and to monitor the healing of grafts. Nuclear imaging provides a sensitive technique for early detection of physiological changes in soft tissue and bone. It has been used in studies of periodontitis, osteomyelitis, oral and maxillofacial tumors, stress fractures, bone healing, temporomandibular joint, and blood flow. This article includes brief descriptions of the technical principles of each imaging modality, reviews their previous uses in oral biology research, and discusses potential future applications in research protocols.

Absorptiometry, Photon↗
PubMed1997

Gender effects on submaximal energy expenditure in children.

Previous studies have suggested that submaximal energy expenditure relative to body mass during weight-bearing exercise may be greater in boys compared to girls. This two-part study examined a) gender-related five-year longitudinal changes in submaximal walking economy and b) gross, net, and delta muscle work efficiency during submaximal cycle exercise in a cross-sectional analysis of boys and girls. In the longitudinal study, the influence of pre-exercise metabolic expenditure, stride frequency, and substrate utilization (by RER) on changes in economy were examined. During the five years, mean VO2 per kg during submaximal treadmill walking (measured at 8% slope, 3.25 mph) decreased 16% in girls and 13% in boys (p > 0.05 for gender). Likewise, no significant gender differences were observed in decline of stride frequency over time. RER values were similar between sexes except in the final two years when girls had significantly greater values than the boys. No gender-related differences were observed in any measure of muscle work efficiency. This study failed to reveal significant gender differences in utilization of energy during submaximal exercise in children.

Child↗
PubMed2001

Seasonal changes in the character and nitrogen content of dissolved organic matter in an alpine/subalpine headwater catchment.

We are studying the chemical quality of dissolved organic nitrogen (DON) in a high-elevation watershed in the Colorado Front Range. Samples were collected over the 2000 snowmelt runoff season at two sites across an alpine/subalpine ecotone to understand how the transition between the lightly vegetated alpine and forested reaches of the catchment influences the chemical character of DON. Samples were analyzed approximately weekly for dissolved organic material (DOM) content and chemical character. A subset of samples was analyzed for the elemental content of fulvic and hydrophilic acids. Concentrations of DON at both sites were highest in the spring at the initiation of snowmelt, decreased during snowmelt, and increased again during the late summer and fall. In contrast, concentrations of dissolved organic carbon (DOC) peaked on the ascending limb of the hydrograph and declined to seasonal minima on the descending limb of the hydrograph. The ratio of DOC:DON showed a seasonal shift at both sites with high values (40 to 55) during peak runoff in early summer and lower values (15 to 25) during low flows late in the runoff season. These results indicate that there was a seasonal change in the relative N content of DOM at both sites. Chemical fractionation of DOC showed that there were temporal and longitudinal changes in the chemical character of DOC. At the alpine site, the fulvic acid content of DOC decreased from 57% in June to 35% in September. The change in fulvic acid was less pronounced at the forested site, from 66% in June to 54% in September. Elemental analysis of fulvic and hydrophilic acids indicated that hydrophilic acids were N rich compared to fulvic acids. Additionally, fulvic and hydrophilic acids isolated at the alpine site had a lower C:N ratio than those isolated at the forested site. Similarly, the C:N ratio of organic acids at both sites was lower in September than in June during peak runoff. These differences appear to be a result of changes in both DOM precursor material and hydrologic flowpaths. Using C:N ratios of fulvic and hydrophilic acids, we estimate that nonhumic material carried between 54 to 73% of the organic N in surface water at the alpine site and 44 to 58% of the organic N in surface water at the subalpine site.

Benzopyrans↗
PubMed2006

Compromised GCF total antioxidant capacity in periodontitis: cause or effect?

BACKGROUND: Oxidative stress is implicated in the pathogenesis of periodontitis. The total antioxidant capacity (TAOC) of gingival crevicular fluid volume (GCF) and plasma appears compromised in periodontitis, but it is unclear whether this predisposes to, or results from the inflammatory process. AIM: To investigate longitudinal changes in GCF and plasma TAOC following reductions in periodontal inflammation with successful non-surgical therapy. MATERIALS AND METHODS: Two longitudinal studies were run in series on non-smokers with chronic periodontitis (CP). Study-1 (n=17) assessed index sites with mild disease; Study-2 (n=18) investigated deep sites. GCF sampling and clinical measures were performed at baseline and 3 months post-therapy. Plasma and GCF TAOC was determined by enhanced chemiluminescence and 32 age/sex-matched periodontally healthy controls were used. RESULTS: Therapy improved clinical outcomes consistent with the literature. There were no differences in plasma TAOC between periodontitis patients (507+/-92 microMTeq) and controls (520+/-100 microMTeq; p=0.57) at baseline, but GCF TAOC was lower (p<0.0001) in CP patients (680+/-371 microMTeq) than controls (1129+/-722 microMTeq). Successful periodontal therapy did not alter plasma TAOC (p=0.56), but GCF TAOC increased (by 449+/-722 microMTeq, p<0.001) to control subject levels (p=0.47) CONCLUSIONS: Local total antioxidant capacity in CP appears to reflect increased oxygen radical activity during periodontal inflammation and can be restored to control subject levels by successful non-surgical therapy.

Adult↗