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PubMed1999

Influence of oxcarbazepine and methsuximide on lamotrigine concentrations in epileptic patients with and without valproic acid comedication: results of a retrospective study.

The aim of this retrospective study was to investigate the influence of oxcarbazepine (OCBZ) and methsuximide (MSM) on lamotrigine (LTG) serum concentrations. The effect of OCBZ compared to carbamazepine (CBZ) and the effect of MSM on LTG serum concentrations were examined in patients with and without valproic acid (VPA) comedication. Altogether, 376 samples from 222 patients were analyzed in routine drug monitoring. Two or more serum samples from the same patient were considered only if the comedication had been changed. For statistical evaluation, regression analytical methods and an analysis of variance were performed. For the analysis of variance, the LTG serum concentration in relation to LTG dose/ body weight--level-to-dose ratio (LDR), in (microg/mL)/(mg/kg)--was calculated and compared for different drug combinations. The nonlinear regression analysis including the LTG dose per body weight, age, gender, and the different kinds of comedication revealed that these variables have a significant influence on LTG serum concentration (r2 = 0.724). The relationship between LTG dose/body weight and serum concentration deviates only slightly from linearity, the LTG concentration was about 18% lower in women than in men, and age had a significant influence. The data indicate that children have significantly lower LTG concentrations than adults on a comparable LTG dose per body weight and that children may be more prone to enzyme induction by comedicated drugs. Methsuximide has a strong inducing effect on the LTG metabolism and decreases the LTG concentrations markedly (about 70% compared to LTG monotherapy). Carbamazepine also reduces the LTG concentrations considerably (by 54%). The inducing effect of OCBZ (29%) was less pronounced but also significant. The inducing effect of MSM, CBZ, and OCBZ was also seen in combination with VPA: VPA alone increases the LTG concentration approximately 211%, whereas in addition to MSM (8%), CBZ (21%), or OCBZ (111%), the increase of LTG was significantly smaller. The analysis of variance confirmed the results of the regression analysis. The effect of MSM on the LTG concentration should be considered if MSM is added or withdrawn in patients treated with LTG. Oxcarbazepine had a less pronounced inducing effect on LTG metabolism compared to CBZ. If CBZ is replaced by OCBZ as comedication, an increase in LTG serum concentrations should be expected.

Adolescent↗
PubMed1998

Adenosine diphosphate-induced platelet activation inhibited by magnesium in a dose-dependent manner.

OBJECTIVE: To examine the hypothesis that magnesium inhibits platelet activation at concentrations equivalent to therapeutic levels. METHODS: Fifteen subjects were enrolled: five healthy, female donors with regular, spontaneous menstrual cycles; five women with uncomplicated third-trimester pregnancies; and five preeclamptic subjects before magnesium therapy. Anticoagulated whole blood was added to tubes containing 0.5 micromol/L adenosine diphosphate (to activate platelets), HP1-1D (activation-independent platelet antibody), CD62 antibody and CD63 antibody (activation-dependent platelet antibodies), and magnesium sulfate in increasing concentrations (2-100 mg/dL). The percentage of activated platelets (CD62 or CD63 positive) was determined using three-color flow cytometric analysis. Data were analyzed using the Student t test, repeated measures analysis of variance, two-way analysis of variance, and Student-Newman-Keuls for pairwise comparison in appropriate cases. P < .05 was considered significant. RESULTS: Adenosine diphosphate-induced platelet activation was inhibited with increasing magnesium concentration in all subjects (P < .001). Significant inhibition of CD62 and CD63 expression first occurred at a magnesium concentration of 4 mg/dL in the normal pregnant group (P < .05), at 6 mg/dL in the preeclamptic group (P < .05), and at 8 mg/dL in the nonpregnant group (P < .05). CONCLUSION: Magnesium inhibits adenosine diphosphate-induced platelet activation in a dose-dependent manner. This effect initially attains statistical significance at concentrations equivalent to therapeutic levels.

Adenosine Diphosphate↗
PubMed2002

QT interval in normal infants during sleep with concurrent evaluation of QT correction formulae.

BACKGROUND: Physiological changes in the QT interval caused by sleep are important in the evaluation of the normal QT interval. Traditionally, Bazett's formula is used for correcting the QT interval for heart rate in childhood. We set out to establish the QT-RR relationship in infants during sleep and concurrently test the performance of four QT correction formulae to determine their comparability and clinical utility. MATERIAL/METHODS: 130 healthy term born infants undergoing routine 8-hour polysomnography were enrolled. Continuous EKG limb lead II recording, saturation monitoring, and electroencephalography were conducted. QT intervals and heart rate were measured manually digitally on-screen at hourly intervals. The QT-RR relationship was plotted and QTc calculated using the Bazett, Hodges, Fridericia and Framingham formulae. QTc values for each formula were plotted against age and RR interval. Analysis of variance and regression analysis were used to compare the four formulae and the QT-RR relationship. RESULTS: Mean age was 17.7 weeks (range 4-72) and mean weight 6.3 kg (range 2.68-12.7). The QT-RR relationship during sleep is curvilinear and appears to be slightly shifted. With increasing heart rate and younger age the Bazett and Hodges formulae overcorrect the QTc whereas the Fridericia and Framingham formulae undercorrect. The Hodges formula correlated best with the RR interval. CONCLUSIONS: These formulae are strongly dependent on heart rate. In the setting of a borderline QTc Bazett prolongation, Hodges formula may be a useful adjunct. Normal infants may have a slightly longer QTc Bazett during sleep.

Age Factors↗
PubMed2004

The effect of glycemic control in type 2 diabetic patients with diabetes-related dyslipidemia.

OBJECTIVE: The study was planned to investigate whether the serum lipid profile in type 2 diabetes mellitus was different between groups of patients classified as having good, satisfactory or poor glycemic controls, depending on their serum fructosamine levels. METHODS: The study was carried out in the Department of Laboratory, Dammam College for Health Sciences, Dammam, Kingdom of Saudi Arabia between February 2003 to June 2003. Clinical laboratory data from diagnosed type 2 diabetic patients were used in the study. One hundred and nineteen patient's data were randomly selected, and according to their serum fructosamine levels, the patients were divided into 3 groups: 29 patients classified as patients with good glycemic control (GGC) with serum fructosamine level <250 micromol/L, 44 patients classified as satisfactory glycemic control (SGC) with serum fructosamine level ranging between 250-355 micromol/L and 46 patients classified as poor glycemic control (PGC) with serum fructosamine >355 micromol/L. The fasting serum glucose and various lipids and lipoprotein concentrations of each group were analyzed by one way analysis of variance and regression analysis. RESULTS: In the PGC group, the serum total cholesterol (6.11+/- 1.56 mmol/l), triglyceride (2.13 +/- 0.71 mmol/L) and very low density lipoprotein-cholesterol (1.09 +/- 0.40 mmol/L) concentrations were significantly higher than that of the SGC (5.59 +/- 0.89, 1.59 +/- 0.38 and 0.86 +/- 0.28 mmol/L,), and the GGC (5.11 +/- 1.06, 1.25 +/- 0.32 and 0.78 +/- 0.29 mmol/L), whereas, those of the SGC were slightly raised, but not statistically significant, compared to the GGC. The high density lipoprotein cholesterol was significantly lower, and the low density lipoprotein cholesterol was elevated in both satisfactory and poorly controlled groups compared to good control group. Significant correlations were evident between the serum fructosamine and glucose concentrations (r=0.79, p<0.0001), and between them as independent parameters and the serum lipid concentrations. CONCLUSION: The glycemic control in type 2 diabetes significantly improves diabetic related dyslipidemia, and would be expected to reduce the risk of atherosclerosis. It is also worth mentioning that the serum fructosamine measure gives a good index for the glycemic control, and its value can reflect the profile of serum lipids.

Adult↗
PubMed2002

Examining costs of chronic conditions in a Medicaid population.

PURPOSE: To compare health care costs and their components in patients with chronic illnesses. DESIGN: Quasi-experimental retrospective database analysis of an integrated state-Medicaid dataset. METHODS: Nine chronic illnesses and 28 two-disease combinations were evaluated in 284,060 patients. Dependent variables were total cost and the component costs (hospital, physician, home health and medical supplies, and pharmacy). Statistical analysis included analysis of variance (ANOVA) and multiple analysis of variance (MANOVA). RESULTS: The nine chronic illnesses studied were: psychosis, depression, cardiovascular illness, congestive heart failure, diabetes, acid peptic illness, respiratory illness/asthma, hypertension, and anxiety. Psychosis and depression patients had the highest mean yearly costs at $6,964 and $5,505, respectively. Highest component costs were mental health practitioners for psychosis and hospital costs for depression. All other conditions had significantly lower yearly costs. Component costs consisted primarily of pharmacy and hospital costs. Psychosis was a component in 5 of the 7 most costly chronic-disease concurrences. The highest disease-concurrence mean cost was for psychosis and depression ($18,318). CONCLUSIONS: The unique resource needs of different chronic illnesses should be considered in benchmarking and evaluating chronic-disease management programs.

Analysis of Variance↗
PubMed2000

Nutrition intervention group program based on preaction-stage-oriented change processes of the Transtheoretical Model promotes long-term reduction in dietary fat intake.

OBJECTIVE: To develop and evaluate the long-term effectiveness of an intervention program, based on preaction-stage-oriented change processes of the Transtheoretical Model of Behavior Change, that could be delivered in a group setting to help participants lower dietary fat intake. DESIGN: An enhanced version of the nonequivalent control group experimental design was used. Entire sections of an undergraduate introductory nutrition science course were assigned to an experimental, pretest/posttest control, or posttest-only control group. Daily fat intake and stage of change of the experimental and pretest/posttest control groups were determined at the pretest and posttest and 1-year later at a follow-up test. Every 1 to 2 weeks during the study, stage of change of the experimental group was assessed. Daily fat intake of the experimental group was assessed at study midpoint. Daily fat intake and stage of change of the posttest-only control group was determined at the posttest. Pretest results were used to place participants of the experimental and pretest/posttest control groups in either the preaction stage (i.e., precontemplation, contemplation, or preparation) or the action/maintenance stage. SUBJECTS/SETTING: The sample consisted of 38, 30, and 42 undergraduate students who were assigned to the experimental, pretest/posttest control, and posttest-only control groups, respectively. INTERVENTION: The experimental group participated in a group-based, dietary fat intake intervention that included a series of 11 lessons taught over a 14-week period. Each lesson was based on 1 or 2 of the preaction-stage-oriented change processes of the Transtheoretical Model. MAIN OUTCOME MEASURES: Data were evaluated to determine the effects of the intervention program on long-term dietary fat reduction and stage of change progression. STATISTICAL ANALYSIS PERFORMED: Analysis of variance, repeated-measures analysis of variance, and paired t tests. RESULTS: For pretest and posttest dietary fat intake scores, stage and time were significant, and there was a significant time-by-stage interaction. Time was significant for pretest and posttest stage scores. Subjects in the preaction-stage experimental group significantly increased their mean stage of change and reduced their fat intake between the pretest and posttest; these changes persisted for 1 year. Pretest/posttest control group participants who began in a preaction stage also significantly increased their mean stage and reduced fat intake by the posttest, but these changes did not endure until the follow-up test. APPLICATIONS/CONCLUSIONS: This intervention program produced an enduring, significant reduction in mean dietary fat consumption and a significant progression in mean stage of change of subjects in the experimental group who were in the preaction stage. It may be appropriate to design group interventions to use preaction stage processes rather than the more traditionally used action and maintenance stages change processes.

Adolescent↗
PubMed1996

Case studies for statistical analysis of toxicokinetic data.

The present paper discusses aspects of the statistical analysis of toxicokinetic data by reference to 102 case studies. In toxicokinetic studies, dose dependence of exposure is the most important subject. For this purpose, and because variability in concentration is closely related to the mean value, before beginning the standard procedures of analysis of variance and regression analysis concentration data should be transformed into logarithms. This data transformation also assists assessment of nonlinear kinetics. The paper discusses a special issue in the analysis of experiments for which measurement on each subject has been repeated. A simple procedure is proposed for estimating the daily exposure level in rodent studies when test chemicals have been mixed in diet and exposure level is measured on different animals at each time point. Experimental designs are classified into three types, and these are illustrated by data from representative case studies. Conclusions from 102 case studies are summarized, with attention to how often sex differences, change in exposure level during repeated dosing, and how often evidence is strong for nonlinear kinetics. Various key points of study design are discussed.

Analysis of Variance↗
PubMed2001

Stability of skeletal Class II correction with 2 surgical techniques: the sagittal split ramus osteotomy and the total mandibular subapical alveolar osteotomy.

Combined orthodontic and surgical treatment of severe Class II dentoskeletal deformities with the use of the bilateral sagittal split ramus osteotomy is a routine procedure in orthodontic practices. However, an alternative surgical technique, the total mandibular subapical alveolar osteotomy, could be used for the same purpose. The aim of this investigation was to compare the stability of the sagittal split ramus osteotomy with the total mandibular subapical alveolar osteotomy in the correction of dentoskeletal Class II malocclusions. Forty patients that exhibited Class II dentoskeletal relationships were included in the study. Twenty of these patients had mandibular advancement with the sagittal split ramus osteotomy; the remaining 20 patients had advancement of the whole lower alveolar segment with the total mandibular subapical alveolar osteotomy. The cephalograms studied were taken before the surgical procedure (T1 = 4 weeks before operation), immediately after the procedure (T2 = 10 days after surgery), and 1 year later (T3). The statistical analysis used to assess the results between and within the groups over the different time periods was the analysis of variance. The regression analysis was used to test the interdependence of soft tissue response to hard tissue movement. The results of this study show that both procedures are equally stable when correcting Class II malocclusions. This was proved by the stability of the correction of overjet, B point, and incisor-mandibular plane angle. There were no statistically significant differences between or within the groups in the position of these landmarks over time. There was a statistically significant change in the position of pogonion from T1 to T2 (P <.0028) between the groups, although at T3 this difference was not significant (P <.05). There were no significant changes in face height either within or between the groups over time. The hard/soft tissue interactions for the total mandibular subapical alveolar osteotomy were as follows: The lower lip advanced 60% to the incisor movement; soft tissue B' point responded with a 130% advancement in relation to the change in its hard tissue counterpart. Soft tissue pogonion advanced 90% in relation to the hard tissue landmark. The data suggest that the total mandibular alveolar osteotomy is the treatment of choice for the correction of severe dentoalveolar retrusive Class II malocclusion for which alteration of the mentolabial sulcus is desirable.

Adolescent↗
PubMed1997

[Usefulness of MR imaging in evaluating and predicting effect of neoadjuvant chemotherapy on uterine cervical carcinoma].

The purpose of this study was to assess the usefulness of MR imaging (MRI) in evaluating and predicting the effect of neoadjuvant chemotherapy on uterine cervical carcinoma. MRI was performed before and after neoadjuvant chemotherapy (NA-C) of systemic BOMP in 32 patients with cervical carcinoma. (1) In 8 patients who suffered from hysterectomy after NA-C, MR estimates of tumor diameter were within 5 mm of the surgical sample in all cases. In addition, MRI accurately evaluated parametrial state. (2) In 10 patients, the reduction rates after 2 courses of NA-C were compared with those after 3 courses, and no significant difference was found between them (p = 0.628). (3) Statistical analysis was performed to assess the correlation between the response to NA-C and MR findings before NA-C such as MR staging, tumor volume, signal intensity and contrast enhancement of tumor, body invasion, total cervical replacement, hydrometra, and ascites. Analysis of variance and multiregression analysis revealed that tumor volume (p = 0.012) and body invasion (p = 0.079) were important factors in predicting the effect of NA-C on cervical carcinoma. In conclusion, MRI is useful in evaluating and predicting the effect of NA-C on uterine cervical carcinoma.

Adult↗
PubMed2004

Food habits are related to glycemic control among people with type 2 diabetes mellitus.

OBJECTIVE: To investigate the food habits of people with type 2 diabetes and to identify those habits related to glycemic control. DESIGN: The purposive sampling plan targeted people (40 to 65 years old) living in two urban communities in the Southeastern United States with type 2 diabetes for >1 year (60% women, 50% African Americans and low-income individuals). In-depth interviews were used to identify food habits. Glycated hemoglobin (HbA(1c)) was measured to assess glycemic control. SUBJECTS: The final sample contained 89 participants (62% women, 48% African American, and 43% below 200% of the poverty level). STATISTICAL ANALYSES PERFORMED: Analysis of variance, principal component/factor analysis, cluster analysis, and multiple regression were used to relate food habits to glycemic control. RESULTS: A four-factor solution derived from 15 food habits explained 51.5% of the total variance in HbA(1c) values. High factor scores for three factors (Basic Eating Practices, Meal Planning, and Carbohydrate/Vegetable Strategies) and low factor scores for a fourth factor (Challenges of Dining Out) were related to lower HbA(1c) values. Based on similar patterns across the 15 food habits, participants were clustered into four groupings. The clusters differing on HbA(1c) (mean+/-standard deviation) were Healthful Eating Lifestyle (6.25+/-0.25), Disciplined Eating Approach (7.31+/-0.35), Limited Dietary Focus (8.28+/-0.33), and Poor Dietary Management (9.05+/-0.24). These groupings reflected different food habit factor profiles. CONCLUSIONS: Knowledge of the specific food habits of people with diabetes can offer a way to structure a meaningful dialog with clients about dietary self-management and guide the collaborative development of relevant dietary goals.

Adult↗
PubMed2005

Prospective gene expression analysis accurately subtypes acute leukaemia in children and establishes a commonality between hyperdiploidy and t(12;21) in acute lymphoblastic leukaemia.

We have prospectively analysed and correlated the gene expression profiles of children presenting with acute leukaemia to the Royal London and Great Ormond Street Hospitals with morphological diagnosis, immunophenotype and karyotype. Total RNA extracted from freshly sorted blast cells was obtained from 84 lymphoblastic [acute lymphoblastic leukaemia (ALL)], 20 myeloid [acute myeloid leukaemia (AML)] and three unclassified acute leukaemias and hybridised to the high density Affymetrix U133A oligonucleotide array. Analysis of variance and significance analysis of microarrays was used to identify discriminatory genes. A novel 50-gene set accurately identified all patients with ALL and AML and predicted for a diagnosis of AML in three patients with unclassified acute leukaemia. A unique gene set was derived for each of eight subtypes of acute leukaemia within our data set. A common profile for children with ALL with an ETV6-RUNX1 fusion, amplification or deletion of ETV6, amplification of RUNX1 or hyperdiploidy with an additional chromosome 21 was identified. This suggests that these rearrangements share a commonality in biological pathways that maintains the leukaemic state. The gene TERF2 was most highly expressed in this group of patients. Our analyses demonstrate that not only is microarray analysis the single most effective tool for the diagnosis of acute leukaemias of childhood but it has the ability to identify unique biological pathways. To further evaluate its prognostic value it needs to be incorporated into the routine diagnostic analysis for large-scale clinical trials in childhood acute leukaemias.

Acute Disease↗
PubMedDate not supplied

Comparison of head circumference in an Israeli child population with United States and British standards.

The head circumference (HC) growth pattern of infants from 1 to 24 months of age was studied in a Jerusalem community. The means of HC of the study population are smaller for each age and sex group than those of the National Center of Health Statistics, USA reference population, London children and the Nellhaus standard. The regression of HC on length explains about 20% of the variance. In an analysis of variance controlling for social class, birth order and length, the differences by region of origin of the mother were not significant. The smaller HC of the study population is probably due to these children being shorter and lighter than the above-mentioned western populations. Malnutrition as a factor for small HC was excluded.

Age Factors↗
PubMed2004

Efavirenz plasma concentrations in HIV-infected patients: inter- and intraindividual variability and clinical effects.

Efavirenz is a drug subject to extensive metabolism, mainly by the cytochrome P-450 isoenzyme CYP2B6, known to exhibit extensive interindividual variability. The aim of the present study was 2-fold: to investigate the relationship between plasma concentration and clinical effects of efavirenz and to investigate the extent of the inter- and intraindividual variability of the plasma concentration measurements. From an open clinic, 68 HIV-positive patients on efavirenz-containing treatment were recruited. From each patient 1 to 5 samples were collected; 43 had more than 1 sample taken. Most samples were taken 10-24 hours after the latest dose. Efavirenz was analyzed by high-performance liquid chromatography with UV detection. The data were analyzed by the variance component model analysis of variance. Efavirenz concentrations were reproducible, and intraindividual variability constituted only 16% of the total variance. Thus, 84% of the variance was attributed to interindividual variability. The incidence of primary treatment failure was related to low plasma concentrations with a geometric mean concentration of 6.1 micromol/L compared with 8.7 micromol/L in those responding to therapy (P < 0.05). If a cutoff of 7 micromol/L is used, 10 of 13 failing to respond were below this level compared with 15 of 45 in those responding. It is concluded that efavirenz plasma concentration measurement gives reproducible results predictive of primary treatment failure. A lower bound for the therapeutic level of 7 micromol/L is proposed, and data from other authors suggests that an upper level of 13 micromol/L may be applied.

Adult↗
PubMed2000

Tumour necrosis factor alpha and its soluble receptors in juvenile chronic arthritis.

OBJECTIVE: To identify possible imbalance of tumour necrosis factor alpha (TNFalpha) and its soluble receptors in the different subgroups of juvenile chronic arthritis (JCA). METHODS: Serum and synovial fluid samples from 45 children were examined, 25 pauciarticular JCA, 13 polyarticular JCA and seven spondyloarthropathy. TNFalpha, sTNFRI and sTNFRII levels were measured by EASIA and enzyme-linked immunosorbent assay (ELISA). Analysis of the results was carried out using non-parametric tests: Kruskal-Wallis one-way analysis of variance was used to compare the three clinical subgroups; the Mann-Whitney U-test was used to compare group medians. RESULTS: Thirty-three serum samples were assayed for TNFalpha. There was no significant difference between the three groups using the Kruskal-Wallis analysis of variance. Analysis of synovial fluid TNF levels showed significantly lower levels in the spondyloarthropathy group compared with the pauciarticular JCA (P = 0.01) and the polyarticular group (P = 0.002). Significantly higher levels of sTNFRI were observed in the synovial fluid of the polyarticular JCA group compared with the pauciarticular JCA group (P = 0.004) and similarly for sTNFRII (P = 0.03). Molar ratios were calculated for TNF vs sTNFRI. The sTNFRI/TNFalpha ratio was significantly higher in the spondyloarthropathy group compared with the pauci- (P 0.003) and the polyarticular JCA subgroups (P = 0.003). The combined soluble receptor levels expressed as molar ratio to TNF again showed a significantly higher ratio in the spondyloarthropathy group compared with the pauciarticular group (P = 0.01) and compared with the polyarticular group (P = 0.05). CONCLUSION: These results suggest that the increased joint destruction observed in polyarticular disease compared with the other two subtypes may be related to the lower sTNFR/TNFalpha ratios observed.

Adolescent↗
PubMed2003

A preliminary analysis of EMG variance as an index of change in EMG biofeedback treatment of tension-type headache.

The effectiveness of EMG biofeedback training for tension headache has been well established. Previous studies evaluating changes in an average EMG activity score from pre- to posttreatment have not consistently found a relationship between a reduction in average EMG activity and headache improvement at posttreatment. The current study is a preliminary analysis of the utility of EMG variance as another possible mechanism of change. Frontalis EMG average activity and variances from 6 chronic tension-type headache sufferers who demonstrated significant improvement in headache activity at posttreatment (at least 70%) and 6 chronic tension-type headache sufferes who did not demonstrate improvement (less than 30%) were examined across 6 sessions of biofeedback treatment. The improved group demonstrated larger time-specific EMG variance in relation to mean EMG amplitudes during all treatment sessions. A dramatic decline in time-specific variance was observed during the later treatment sessions for improved participants; this pattern was not observed in the group who demonstrated little or no improvement. Results from the current study suggest that the inclusion of both average EMG activity and EMG variance may provide a more comprehensive measure to evaluate possible physiological changes responsible for improvement in headache activity following EMG biofeedback training.

Adolescent↗
PubMed2001

In vitro comparison of the fracture resistance and failure mode of fiber, ceramic, and conventional post systems at various stages of restoration.

PURPOSE: This in vitro study evaluated 6 post systems over 4 simulated clinical stages of tooth restoration to (1) determine quantitatively the fracture resistance strength at each stage when a static loading force is applied to cause failure; (2) determine the failure mode for each post system at each simulated clinical stage; and (3) determine the feasibility of removing failed post systems. MATERIALS AND METHODS: Ten post systems made with various materials and designs were tested at the following 4 stages of simulated clinical treatment: stage #1: posts only, loaded using a 3-point loading model to failure, to determine transverse strengths and failure modes for each post system; stage #2: posts alone, bonded into teeth; stage #3: posts bonded into teeth with core build up; stage #4: post and core build up and full veneer restoration. For stages #2 through #4, the coronal portion of 60 mandibular premolars was amputated at the cemento-enamel junction, the canals were treated endodontically, and the specimens were mounted in acrylic blocks. A testing force was applied to the posts at 90 degrees to the long axis of the tooth, 4 mm from the cemento-enamel junction. The O'Brien test for constant variance was performed over the treatment groups. For nonconstant variance, the Welsh analysis of variance was used to test for equalities of treatment means. The Tukey Kramer procedure determined which treatment procedures differed. RESULTS: The failure thresholds for each post system were significantly different at each stage of testing, but the order of test results by post type remained generally consistent from one stage to the next. ParaPosts (Coltene, Whaledent Int, New York, NY) and core build up resulted in significantly higher failure thresholds through all 4 stages of testing. This post system also consistently displayed a high number of nonfavorable tooth fractures. FibreKor post and cores (Jeneric Pentron Inc, Wallingford, CT) resulted in significantly lower failure threshold values in stages #2 through #4. This post system displayed no tooth fractures in stages #2 and #3 and a similar number of nonfavorable tooth fractures in stage #4 when compared with the other systems. C-Post (Bisco Dental Products, Schaumburg, IL), CosmoPost (Ivoclar Vivadent North America Inc, Amherst, NY), and AesthetiPost (Bisco Dental Products) grouped in descending order through stages #2 to #4. These systems displayed intermediate fracture resistance strengths, as well as a moderate number of nonfavorable tooth fractures. CosmoPost exhibited a significant number of brittle post fractures with fragments left in the root canal at all stages. The fracture resistance of the cast metal post varied from stage to stage. No teeth fractured at stage #2. At stage #3, 9 of 10 teeth fractured nonfavorably, and all teeth fractured nonfavorably in stage #4. CONCLUSIONS: The fiber posts evaluated provided an advantage over a conventional post that showed a higher number of irretrievable post and unrestorable root fractures. At the stage of final restoration insertion, there was no difference in force to failure for all but the FibreKor material, which continued to be weaker than all other tested materials. The fiber posts were readily retrievable after failure, whereas the remaining post systems tested were nonretrievable. J Prosthodont 2001;10:26-36.

Analysis of Variance↗
PubMed2000

Genetic and environmental influence on the asymmetry of dermatoglyphic traits.

Fluctuating asymmetry (FA) is defined as random deviations from bilateral symmetry of the body. Thus, its magnitude is often used to evaluate developmental homeostasis. In this study we evaluate the following hypotheses: 1) FA of dermatoglyphic traits has a significant genetic component; 2) prenatal maternal environment (PME) has a significant effect on the FA of dermatoglyphic traits in developmentally healthy individuals; and 3) genetic or environmental factors affect FA on organismal or systemic levels. Therefore, their effect is better seen in composite scores of FA rather than in FA indices for single traits. We analyzed 15 dermatoglyphic traits from 140 pairs of monozygous twins, 120 pairs of dizygous twins, and 106 pairs of mothers and daughters. All individuals were developmentally healthy. The influence of genetic and environmental factors on FA was evaluated by analysis of variance and regression analysis. For a majority of the traits in our study, FA showed significant but weak heritabilities, with values falling within the 0.20-0.35 range. None of the traits taken separately demonstrated the effect of PME on FA to be significantly greater than zero. The composite score of FA tended to have greater heritability values than individual traits. One of them, obtained in principal components analysis, showed a significant PME effect, supporting the hypothesis that FA is a systemic property.

Analysis of Variance↗
PubMedDate not supplied

Virulence properties of Escherichia coli strains in patients with chronic pyelonephritis.

In 50 Escherichia coli strains obtained from the bladder puncture urine of patients with chronic pyelonephritis, determinations of virulence properties were performed. All of the E. coli strains isolated from 26 acute episodes of pyelonephritis were found in the smooth form. 30% possessed K 1 antigen, 77% showed the ability to form hemolysin and 30% produced colicin V (aerobactin). Fimbriae (detected by mannose-resistant hemagglutination) were registered in 81%, and plasmids ranging between 50 and 70 Md were demonstrated in 70% of the bacteria. In contrast to this, only 70% of the E. coli strains isolated from 24 patients at an inactive stage of pyelonephritis were found in the smooth form; 10% of these encoded K 1 antigen, 20% hemolysin and 10% colicin V. Plasmids in the range 50 to 70 Md could be found in 30%. On the basis of multivariate analysis of variance and discriminant analysis, it was confirmed that uropathogenic strains possess several virulence properties, mannose-resistant hemagglutination being of particular importance.

Adult↗