Overestimates of oleic and linoleic acid contents in materials containing trans fatty acids and analyzed with short packed gas chromatographic columns.
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Animals↗
Biomedical subjects
M K McGuire
Publications and source records attributed to M K McGuire.
2001 Interdisciplinary Care Conference: five disciplines, one focus. Periodontics: the odyssey continues.
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Biomedical Engineering↗
Estimation of conjugated linoleic acid intake by written dietary assessment methodologies underestimates actual intake evaluated by food duplicate methodology.
Conjugated linoleic acids (CLA) are conjugated isomers of linoleic acid, which may promote health with regard to cancer, heart disease, diabetes, bone formation, growth modulation and immunity. The c9,t11 isomer of CLA, rumenic acid (RA), is the major isomer present in the diet. However, dietary intakes of CLA and RA by humans have not been examined rigorously, nor has the relationship between dietary CLA or RA and health (e.g., body composition). Three-day dietary records (DR) were collected from adult men (n = 46) and women (n = 47) and analyzed using a nutrient database modified to contain total CLA and RA. Simultaneously, 3-d food duplicates (FD) were collected to determine analytically individual fatty acid intakes, including those of total CLA and RA. Chronic total CLA and RA intakes were estimated using a semiquantitative food-frequency questionnaire (FFQ). Body composition was estimated using body mass index and percentage of body fat. Total CLA intake was estimated from FD to be 212 +/- 14 and 151 +/- 14 mg/d (mean +/- SEM) for men and women, respectively; RA intake was estimated to be 193 +/- 13 and 140 +/- 14 mg/d for men and women, respectively. In general, CLA and RA intakes estimated by DR and FFQ were significantly lower than those estimated by FD. Body composition was not significantly related to dietary total CLA or RA intake. In conclusion, results suggest that DR and FFQ methodologies are not reliable estimators of individual total CLA and RA intakes and may underestimate total CLA and RA intakes of groups. Intake of total CLA and RA was found to be significantly lower than that suggested previously by others.
Adult↗
Prognosis vs outcome: predicting tooth survival.
The assignment of prognosis is one of the most important functions undertaken in clinical practice, yet there is little evidence to support the current decision-making process. This article will review four articles that evaluate the traditional method of assigning a prognosis and predicting tooth survival. Limitations of the current method of assigning a prognosis are discussed, and models are presented that should allow clinicians to be more confident in their projections.
Adult↗
High-fat dairy product consumption increases delta 9c,11t-18:2 (rumenic acid) and total lipid concentrations of human milk.
Conjugated octadecadienoic acids (18:2, conjugated linoleic acids) have been shown to be anticarcinogenic and may influence growth and nutrient partitioning. The delta 9c,11t-18:2 isomer (rumenic acid, RA) is most common in both food sources and human tissues. To determine if maternal diet can influence milk RA concentration, breastfeeding women (n = 16) were enrolled in a 3-wk crossover study. Women initially consumed minimal amounts of food containing RA during week 1, then were assigned randomly to consume diets rich in high-fat dairy foods (and thus RA) during week 2 or 3. Milk was collected by complete breast expression twice during each experimental week. Current and chronic RA intakes were estimated by 3-d dietary records and food frequency questionnaires, respectively. Estimated chronic RA intakes ranged from 49 to 659 mg/d. Dietary RA intake was greater during the high compared to the low dairy period (291 +/- 75 vs. 15 +/- 24 mg/d, respectively; P < 0.0001). Milk contained more RA during the high than the low dairy period (13.5 +/- 0.1 vs. 8.2 +/- 0.4 mumol/g lipid, respectively; P < 0.0001). Milk lipid concentration was influenced by diet, such that lipid concentration was greater during the high than the low dairy period (46.6 +/- 5.0 vs. 38.3 +/- 1.6 mg/g milk, respectively; P < 0.05). Additionally, multiple regression analyses suggested that body mass index was the primary predictor of milk RA and lipid concentrations. In summary, these data indicate that both lipid and RA concentrations of human milk can be influenced by diet.
Adult↗
Prognosis versus actual outcome. IV. The effectiveness of clinical parameters and IL-1 genotype in accurately predicting prognoses and tooth survival.
BACKGROUND: Recently, a genetic marker (IL-1 genotype) that identifies individuals at higher risk for developing severe periodontal disease was discovered. A subgroup of the population reported on earlier was evaluated to determine if knowledge of the patient's IL-1 genotype would improve accuracy in assignment of prognoses and prediction of tooth loss. METHODS: This subgroup consisted of 42 patients (1,044 teeth) in maintenance care for 14 years; 16 tested IL-1 genotype-positive (IL-1GP). Nine were smokers, and 30 had a history of smoking, with an average of 29.44 pack years. A multiple Cox regression model and Kaplan-Meier survival plots were fit to the subset of patients to evaluate tooth loss. RESULTS: Both IL-1GP and heavy smoking were significantly related to tooth loss. A positive IL-1 genotype increased the risk of tooth loss by 2.7 times, and heavy smoking by 2.9 times. The combined effect of IL-1GP and heavy smoking increased the risk of tooth loss by 7.7 times. The value of clinical parameters traditionally used to assign prognosis was found to be dependent on IL-genotype and smoking status. In the model that included IL-1 genotype and heavy smoking, none of the clinical parameters added significantly to the model for tooth loss while mobility, probing depth, crown-to-root ratio, and percent bone loss added significantly to the model, which included IL-1 genotype in non-smokers. IL-1GP patients and patients who smoked heavily demonstrated a much worse tooth survival rate when compared to IL-1 genotype-negative patients and non-smokers, respectively. CONCLUSIONS: Knowledge of the patient's IL-1 genotype and smoking status will improve the clinician's ability to accurately assign prognosis and predict tooth survival. Clinical implications are as follows. Investigators were unable to judge which patients would be IL-GP or negative based on their clinical presentation or family history of tooth loss due to periodontal disease. Since periodontal diseases are multifactorial, knowledge of the patient's genotype is more important in predicting future risk than explaining past disease. Knowledge of IL-1 genotype status would be important in developing a treatment plan and predicting tooth survival for a new patient who smokes and presents with periodontal disease, especially if restorative care is needed. Knowledge of a maintenance patient's IL-1 status would help target therapy for non-responding areas; one would be less likely to take a "wait and see approach" with IL-1GP patients. IL-1 positive non-smokers can be successfully treated and maintained over long periods of time.
Adult↗
Safflower oil consumption does not increase plasma conjugated linoleic acid concentrations in humans.
Conjugated linoleic acid (CLA) is a mixture of positional and geometric isomers of linoleic acid (LA) with conjugated double bonds. CLA has anticarcinogenic properties and has been identified in human tissues, dairy products, meats, and certain vegetable oils. A variety of animal products are good sources of CLA, but plant oils contain much less. However, plant oils are a rich source of LA, which may be isomerized to CLA by intestinal microorganisms in humans. To investigate the effect of triacylglycerol-esterified LA consumption on plasma concentrations of esterified CLA in total lipids, a dietary intervention (6 wk) was conducted with six men and six women. During the intervention period a salad dressing containing 21 g safflower oil providing 16 g LA/d was added to the subjects' daily diets. Three-day diet records and fasting blood were obtained initially and during dietary and postdietary intervention periods. Although LA intake increased significantly during the dietary intervention, plasma CLA concentrations were not affected. Plasma total cholesterol and LDL-cholesterol concentrations were significantly lower after addition of safflower oil to the diet. In summary, consumption of triacylglycerol-esterified LA in safflower oil did not increase plasma concentrations of esterified CLA in total lipids.
Adult↗
Periodontal plastic surgery.
Most periodontal esthetic procedures can be grouped into one of the following areas: crown lengthening, alveolar ridge preservation/augmentation, soft tissue grafts, and the correction of an open interproximal space. Soft tissue abnormalities, with the exception of the loss of the interproximal papilla, can be resolved predictably, improving esthetics and even creating restorative opportunities. In addition to a discussion of the pretreatment esthetic evaluation, an overview of periodontal plastic surgery procedures is presented, along with an example of the "Periodontal Enhancement Prescription," which facilitates communication between offices.
Alveolar Ridge Augmentation↗
Leptin is present in human milk and is related to maternal plasma leptin concentration and adiposity.
Leptin is elevated during pregnancy and may be involved in the regulation of milk production in women. Immunoreactive leptin was quantified in human milk by modified radioimmunoassay. Leptin concentration was higher in whole vs. skim milk fractions; however, leptin concentration was not correlated with percentage milk fat. Leptin concentrations in whole and skim milk were correlated with maternal plasma leptin concentrations, maternal body weight, body mass index, and tricep skinfold thickness, but not with plasma insulin concentration. These data provide the first evidence for the presence of leptin in human milk in the range of concentrations found in human plasma and indicate that the concentration of leptin in milk reflects maternal adiposity. Determining the biological role(s) of milk-borne leptin could add to our understanding of neonatal metabolism and the mechanisms underlying the development of body fat and obesity in humans.
Adipose Tissue↗
Food supplementation during lactation shortens anestrus and elevates gonadotropins in rats.
Breastfeeding delays the resumption of ovulation in women, a phenomenon particularly important in less developed areas. Although human and animal studies indicate that undernutrition extends the period of lactational anestrus, the effect of improving nutritional status during lactation on this time of infecundability, however, is less clear. To assess the effects of food supplementation on duration of lactational anestrus, Sprague-Dawley rats were assigned to one of three dietary groups: 1) control (C), given unrestricted access to diet AIN-76A; 2) food-restricted (FR), fed 50% of the control intake; and 3) food-supplemented (FS), food-restricted until d 0 of lactation and thereafter given unrestricted access to diet AIN-76A. Time to first detectable proestrus was monitored starting on d 10 of lactation. Nursing behaviors and gonadotropin and prolactin concentrations were measured in both intact and ovariectomized dams on d 10, 15 and 20 of lactation; we report these data only on the ovariectomized group, which represents the more appropriate animal model of human reproductive physiology during lactation. Proestrus returned significantly (P < 0.0001) sooner in both FS (18.1 +/- 2.4 d) and C (18.0 +/- 2.9 d) than in FR (28.8 +/- 2.8 d) intact dams. FS rats had higher luteinizing hormone and follicle stimulating hormone concentrations than FR rats (P < 0.0001 for each). Prolactin concentrations were lower on d 20 than on d 10 of lactation for all groups (P < 0.02), but we found no effect of dietary treatment. FS rats spent more time away from their pups (P < 0.05) and experienced less suckling (P < 0.05) than FR rats on d 15 of lactation. These results indicate that food supplementation of previously underfed rats hastens the return of ovulation and is accompanied by alterations in nursing behaviors.
Anestrus↗
Documentation of second-by-second breastfeeding behaviors using a novel method.
The specific way nursing patterns influence the duration of postpartum amenorrhea is unknown. This may result from the shortcomings of available methods: the daily log and recall. We tested these against a novel method, an event monitor (EM), consisting of a wrist-worn stopwatch that stores events. Exclusively breastfeeding women (n = 11) were assigned randomly to use each of the three methods twice during a 2-week period surrounding Weeks 4, 8, and 12 postpartum. More nursing episodes were recorded with the EM than log during Week 4 (p < 0.03) and Week 8 (p < 0.02). EM captured more episodes than recall during all study periods (p < 0.004). The EM was considered as acceptable and accurate to mothers as the other methods and, therefore, is a useful option for documenting breastfeeding patterns.
Adult↗
Tetracycline fibers plus scaling and root planing versus scaling and root planing alone: similar results after 5 years.
This paper presents 5-year data pertaining to a subgroup of patients from a previous investigation who were treated with scaling and root planing plus tetracycline fibers. The parent study demonstrated that 6 months after therapy, scaling and root planing plus tetracycline fiber therapy was significantly better at reducing probing depth and gaining clinical attachment than scaling and root planing alone. However, the long-term data presented here show a regression from the original gains in clinical attachment levels in the fiber group. Ultimately, the use of fibers provided no significant advantage with regards to probing depth reduction or clinical attachment gain. Within the power of this study, which would have required 1.78 mm of change in clinical attachment to show a difference, there was no significant difference between the treatments at 5 years. This study underscores the need for additional long-term evaluation of this mode of therapy.
Analysis of Variance↗
Naloxone administration does not relieve the inhibition of gonadotropin release in food-restricted, lactating rats.
Lactational anovulation is an important factor in determining birth spacing in women living in developing countries. Therefore, a more comprehensive understanding of the mechanisms involved in the relationships among lactation, nutrition and ovulation is important. This study was designed using the food-restricted, lactating rat to examine whether endogenous opioids might be involved in depressing gonadotropin release. Females were mated after 65 d of age and, beginning on d 42 of life, offered food in unrestricted amounts (control) or were food restricted to 50% of what the controls consumed. On d 15 of lactation, dams were injected with either naloxone hydrochloride (3 mg/kg body weight) or saline and killed 0, 15, 30 or 60 min later. Plasma was analyzed for luteinizing hormone, follicle-stimulating hormone and prolactin. Food restriction decreased plasma concentrations of luteinizing hormone and follicle-stimulating hormone (P < 0.005). Naloxone administration marginally influenced follicle stimulating hormone (P < 0.1), but not luteinizing hormone concentration regardless of diet group. The interaction among diet group, drug group and time of killing was significant for plasma prolactin concentration (P < 0.05). Food restriction lowered prolactin concentrations, but this effect was diminished with increasing time after injection of naloxone. Furthermore, the magnitude of the effect of food restriction was lessened and even reversed with treatment of naloxone. These results indicate that endogenous opioids are not the primary mechanism suppressing luteinizing hormone release in food-restricted lactating rats.
Animals↗
Prognosis versus actual outcome. II. The effectiveness of clinical parameters in developing an accurate prognosis.
The assignment of prognosis is one of the most important functions undertaken in clinical practice, yet there is little evidence to support the current decision-making process which is based on an outdated model of disease etiology and progression. This study evaluated 100 treated periodontal patients (2,484 teeth) under maintenance care for 5 years, with 38 of these patients followed for 8 years, to determine the relationship of assigned prognoses to the clinical criteria commonly used in the development of prognosis. The method of generalized estimating equations (GEE) for correlated data was utilized to determine the relationship of each clinical factor to the assignment of initial prognosis, improvement in prognosis at 5 years, and worsening in prognosis at 5 years. A multiple linear regression model was constructed for predicting initial prognosis based on initial clinical data. Increased probing depth, more severe furcation involvement, greater mobility, unsatisfactory crown-to-root ratio, malpositioned teeth, and teeth used as fixed abutments resulted in worse initial prognoses. The coefficients from this model were able to predict accurately the 5-year and 8-year prognoses 81% of the time. When teeth with "good" prognoses were excluded, the predictive accuracy dropped approximately 50%. Multiple logistic regression models indicated that improvement in prognoses and worsening in prognoses were both strongly associated with initial probing depth, initial furcation involvement, initial tooth malposition, and smoking when adjusted for initial prognosis. In addition, good hygiene was found to increase the probability of improvement in prognosis while initial mobility was found to decrease the likelihood of improvement in prognosis. Neither of these factors was found to be significant in worsening of prognosis. Smoking decreased the likelihood of improvement by 60% and doubled the likelihood of worsening in prognosis at 5 years. The results of this study indicate that some clinical factors used in the assignment of prognoses are clearly associated with changes in clinical condition over time. The data also demonstrated that the traditional approach for assigning prognoses is ineffective for teeth with an initial prognosis of less than good. Since most periodontally involved teeth are compromised, further work should include the development of a more effective method for assigning prognoses that is based on clear, objective clinical criteria.
Age Factors↗
Prognosis versus actual outcome. III. The effectiveness of clinical parameters in accurately predicting tooth survival.
Tooth loss for 100 treated periodontal patients (2,509 teeth) under maintenance care was evaluated to determine the effectiveness of commonly taught clinical parameters utilized in the assignment of prognosis in accurately predicting tooth survival. Previous studies in this series evaluated prognosis as a surrogate variable representing the condition of the tooth at a particular point. In this study, survival analysis was used to evaluate the relationship of these common clinical parameters to an actual end point, tooth loss. Robust log rank tests indicated that initial probing depth, initial furcation involvement, initial mobility, initial crown-to-root ratio, and initial root form were all associated with tooth loss. In addition, smoking and increased initial bone loss were both found to be associated with increased risk of tooth loss while fixed abutment status was associated with a decreased risk of tooth loss. A Cox proportional hazards regression model showed that initial probing depth, initial furcation involvement, initial mobility, initial percent bone loss, presence of a parafunctional habit without a biteguard, and smoking were all associated with an increased risk of tooth loss. This model suggests that patients are twice as likely to loose their teeth if there is increasing mobility, if they have a parafunctional habit and do not wear a biteguard, or if they smoke. From these data there does appear to be a relationship between the assigned prognosis and tooth loss. Teeth with worse prognosis have a worse survival rate, but the commonly taught clinical parameters used in the traditional method of assignment of prognosis do not adequately explain that relationship. Furthermore, initial prognosis did not adequately explain the condition of the tooth or accurately predict the tooth's survival. These results seem to indicate that the effect of these clinical parameters on tooth survival is only partially reflected in the assigned prognosis initially, suggesting that perhaps some of the clinical parameters should be weighed more heavily than others when assigning prognosis. Further studies are needed to develop a more accurate method for the assignment of prognosis.
Alveolar Bone Loss↗
Evidence-based periodontal regenerative therapy.
Periodontal health care has progressed into a new era. It is distinguished by a rapidly expanding volume of literature, rapid influx of new technologies, and need for new skills to perform increasingly complex procedures. Correspondingly, practice management changes are required to adapt to the extensive follow-up care associated with some of these new treatments. This must be accomplished while also acknowledging the deepening concern for escalating costs and increased attention to the quality of care provided. As with most change, clinicians can fight it by continuing to rely on old ways of doing things and hope to keep these issues at bay, but history would say they are unlikely to succeed. Instead, clinicians can embrace these changes and adapt to them by adding new tools, such as evidence-based methodology, to their armamentarium. The evidence-based approach offers a "bridge" from science to clinical practice. It can strengthen the foundation by providing a framework for integrating patient preferences, scientific knowledge, clinical judgment, and personal experience. By adapting the way treatment decisions are made in daily practice to an evidence-based approach, clinicians can deliver the highest quality care to their patients and be in better control of their own destiny. These new challenges can be perceived as problems or as opportunities--it is a choice!
Bibliographies as Topic↗
Maintaining esthetic restorations in the periodontal practice.
Esthetic dentistry comprises one of the most rapidly growing segments of our profession, and patients receiving this type of treatment are often maintained on an alternating schedule. Improper maintenance care can quickly destroy many of these restorations. This article will serve as a resource for dental professionals who wish to offer these special patients customized maintenance care.
Aluminum Oxide↗
Soft tissue augmentation on previously restored root surfaces.
Three cases are presented demonstrating that soft tissue augmentation procedures can be accomplished on previously restored root surfaces. Diagnostic techniques to help determine ideal tooth length are discussed, and clinical examples of how to surgically manage the previously restored root surfaces are presented.
Alveolar Bone Loss↗