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PubMed2003

Association of damage with autoantibody profile, age, race, sex and disease duration in systemic lupus erythematosus.

OBJECTIVE: To determine if there is any association between autoantibody profile and damage in a cohort of patients with systemic lupus erythematosus (SLE). METHODS: A prospective cohort of SLE patients attending two SLE clinics in Birmingham was analysed. All patients fulfilled ARA criteria for SLE. Detailed clinical and serological information was recorded at each visit. Damage according to the Systemic Lupus International Collaborating Clinics/American College of Rheumatology Damage Index (SLICC/ACR DI) was recorded 6-monthly and the last score in the year 2000 or prior to death was used in the analysis. Univariate analysis was performed with the chi(2) test, Fisher's exact test or univariate analysis of variance. Multivariate analysis was done with binary logistic regression. RESULTS: A total of 348 patients (326 females) were studied, comprising 208 Caucasians, 65 Afro-Caribbeans, 59 Asians, four Orientals and 12 others. There were 32 (9.2%) deaths and 156 (44.8%) patients had damage recorded during follow-up. The presence of damage showed no significant association with race, sex or anti-cardiolipin, anti-Ro, anti-La, anti-Sm, anti-RNP and anti-dsDNA antibodies. Only age, disease duration and other antibodies to extractable nuclear antigens (ENA) were found to be associated with the presence of damage. When individual organ damage was analysed, the only significant associations were of anti-Ro with ocular damage and of other anti-ENA antibodies (anti-Scl-70 and/or anti-Jo-1) with premature gonadal failure. Other autoantibodies were not predictive of damage in individual organs. CONCLUSIONS: Although autoantibodies are useful in diagnosis and predicting disease activity in SLE, they do not appear to be useful in predicting damage in SLE.

Adolescent↗
PubMed1995

Effects of resistance training on strength, power, and selected functional abilities of women aged 75 and older.

OBJECTIVE: To determine the effects of 12 weeks of progressive resistance strength training on the isometric strength, explosive power, and selected functional abilities of healthy women aged 75 and over. DESIGN: Subjects were matched for age and habitual physical activity and then randomly assigned into either a control or an exercise group. SETTING: The Muscle Function Laboratory, Royal Free Hospital School of Medicine, London. PARTICIPANTS: Fifty-two healthy women were recruited through local and national newspapers. Five dropped out before and seven (4 exercisers and 3 controls) during the study. Pre- and posttraining measurements were obtained from 20 exercisers (median age 79.5, range 76 to 93 years) and 20 controls (median age 79.5, range 75 to 90 years). INTERVENTIONS: Training comprised one supervised session (1 hour) at the Medical School and two unsupervised home sessions (supported by an exercise tape and booklet) per week for 12 weeks. The training stimulus was three sets of four to eight repetitions of each exercise, using rice bags (1-1.5 kg) or elastic tubing for resistance. The exercises were intended specifically to strengthen the muscles considered relevant for the functional tasks, but were not to mimic the functional measurements. No intervention was prescribed for the controls. MEASUREMENTS: Pre- and posttraining measurements were made for isometric knee extensor strength (IKES), isometric elbow flexor strength (IEFS), handgrip strength (HGS), leg extensor power (LEP), and anthropometric indices (Body impedance analysis, arm muscle circumference, and body weight). Functional ability tests were chair rise, kneel rise, rise from lying on the floor, 118-m self-paced corridor walk, stair climbing, functional reach, stepping up, stepping down, and lifting weights onto a shelf. Pre- and posttraining comparisons were made using analysis of variance or analysis of covariance (using weight as a covariate) for normally distributed continuous data and one-sided Fishers exact test (2 x 2 table) for discontinuous data. RESULTS: Improvements in IKES (mean change 27%, P = .03), IEFS (22%, P = .05), HGS (4%, P = .05), LEP/kg (18%, P = .05) were associated with training, but the improvement in LEP (18%, P = .11) did not reach statistical significance. There was an association between training and a reduction in normal pace kneel rise time (median change 21%, P = .02) and a small improvement in step up height (median 5%, P = .005). The other functional tests did not improve. CONCLUSIONS: Progressive resistance exercise can produce substantial increases in muscle strength and in power standardized for body weight in healthy, very old women. However, isolated increases in strength and LEP/kg may confer only limited functional benefit in healthy, independent, very old women.

Activities of Daily Living↗
PubMed1995

Effect of gingival wall on resistance to probing forces.

This study was conducted to determine whether the gingival tissue lateral to the periodontal sulcus contributes resistance to the advancement of a periodontal probe tip into the sulcus under different applied pressures. An electromechanical device was used to advance a probe tip 0.6 mm in diameter into the facial sulcus at a constant speed until resisting forces of 0.70 N were encountered. The device registered the resisting force and probe advancement simultaneously. The gingiva of all 2nd incisors, 2nd premolars, and 1st molars of 4 young adult male beagle dogs were tested. After the first measurement, the buccal gingiva of experimental sites were incised mesiodistally from the gingival margin to the alveolar crest and the sulcus was reprobed. 2 experimental and control quadrants were selected randomly resulting in 6 sets of both experimental and control data from each animal. The data were analyzed with analysis of variance. The analysis demonstrated significant variation from site to site, and dog to dog; therefore, only changes between the 1st and 2nd probings at the same sites could be compared. Less variability of probing distance in different animals occurred at higher forces; however, the incision had a significant effect on probing distance at these forces. The pressure at which probing distance had less variability among animals and least affected when the gingival sulcular wall was incised was estimated to be 106 N/cm2. This corresponds to 30 g force on the 0.6 mm diameter probe.

Analysis of Variance↗
PubMed1999

Effects of air pollution and weather conditions on asthma exacerbation.

BACKGROUND: Meteorological conditions and a high concentration of air pollutants have been associated with increased respiratory morbidity. However, few studies have examined the association between asthma exacerbation and air pollution. OBJECTIVES: In the present study, the possible relationship of the concentration of black smoke and SO2 in the air, the local weather conditions and emergency room visits for asthma is investigated. METHODS: The weekly total of emergency room admissions for asthmatic adults during a 1-year period was recorded together with daily metereological conditions (average temperature, humidity, rainfall, wind speed and barometric pressure) and average weekly levels of daily pollutant concentrations (black smoke and SO2). The relationship was assessed by stepwise regression linear models and analysis of variance. The analysis took into account season and metereological variables. RESULTS: Both air pollutants correlated significantly with emergency room admissions for asthma (SO2 [r = 0. 32], black smoke [r = 0.35]); however, multiple regression analysis showed that black smoke was the only significant predictor of weekly visits. There were approximately 3.5 admissions a week per SD of change (34.6 microg.m-3). There were no significant correlations between weekly emergency room visits and the weather variables. Analysis of the data stratified by season and weather conditions demonstrated that the association of black smoke with asthma exacerbation was more pronounced in autumn (r = 0.67) or when temperatures were higher than average. CONCLUSION: In our city, a high concentration of certain air pollutants is indeed associated with an increase in the number of hospital emergency room admissions for asthma.

Adolescent↗
PubMed2000

Bone lead levels and language processing performance.

The relation between bone lead absorption and language processing abilities in 156 randomly selected 11- to 14-year-old boys who were asymptomatic for lead toxicity is examined. Tibial lead concentrations were measured by X-ray fluorescence spectroscopy. The language processing outcome variables consisted of the least and most difficult subtests from the Nonword Repetition Task, Competing Language Processing Task, and the Revised Token Test. Participants were classified by quartiles according to bone lead concentrations, and analysis of variance and analysis of covariance measured the impact on language processing scores. Results showed that children in the highest bone lead quartile displayed decreased language processing performance on the most difficult language processing tasks but not on the easier tasks.

Adolescent↗
PubMed2003

Analysis of digital images acquired using different phosphor storage plates (PSPs) subjected to varying reading times and storage conditions.

OBJECTIVES: To assess, both objectively and subjectively, the effects of different combinations of storage conditions and varying delays in reading on digital images captured using phosphor storage plates (PSPs). METHOD: Standardized images were obtained of an aluminium step wedge and a dry mandible in acrylic using GE 1000 and PSPs from the Digora (Soredex) and DenOptix (Gendex) digital systems. Twelve plates from each system were exposed and immediately scanned to produce the baseline gold standard. The plates were re-exposed and stored using three different storage combinations, (A) ambient temperature, (R) refrigeration and (S) low humidity, and then scanned after 6 h, 12 h, 18 h, 24 h, 48 h or 72 h. Objective analysis was carried out by pixel density measurements and the data were analysed statistically using analysis of variance. Subjective analysis was carried by three oral radiologists and the results were analysed using Mann-Whitney U-test. RESULTS: For the DenOptix system there were no differences either objectively or subjectively in the images obtained from all the plates using different storage conditions and after varying time intervals. For Digora, objective analysis showed loss of pixel density after 6 h using all storage conditions. This loss of density was also evident subjectively after 6 h on plates stored under certain storage conditions. CONCLUSION: Storage of DenOptix PSPs for up to 72 h in different conditions does not affect the quality of the digital images. However, there is a loss of image density within 6 h when using Digora PSPs, which may affect clinical image interpretation.

Analysis of Variance↗
PubMed2006

What happens if you delay scanning Digora phosphor storage plates (PSPs) for up to 4 hours?

OBJECTIVES: To assess, both objectively and subjectively, the effects of different combinations of storage conditions and delaying scanning for up to 4 h on digital images captured using Digora phosphor storage plates (PSPs). METHOD: Standardized images were obtained of an aluminium step wedge and dry mandible in acrylic using GE 1000 and phosphor storage plates (PSPs) from the Digora (Soredex) digital system. 12 plates were exposed and immediately scanned to produce the baseline gold standard. The plates were re-exposed and stored using three different storage combinations--(A) ambient temperature, (R) refrigeration and (S) low humidity, and then scanned after 10 min, 30 min, 1 h, 2 h, 3 h or 4 h. The objective analysis was carried out by pixel density measurements and the data analysed statistically using analysis of variance. Subjective analysis was carried out by three oral radiologists and the results analysed using the Mann Whitney U-test. RESULTS: Objective analysis showed loss of pixel density after 4 h using all storage combinations. Subjectively, this loss of density was not evident. CONCLUSION: There is a loss of image density at 4 h when using Digora PSPs which can not be detected clinically, but could compromise multisite research.

Absorptiometry, Photon↗
PubMed2006

Isokinetic strength of collegiate baseball pitchers during a season.

Pitching is suggested to expose the arm to physical stress that may lead to a decrease in strength. The purpose of this study was to examine the isokinetic internal and external rotational shoulder strength of Division II pitchers preseason, midseason, and postseason. The 9 pitchers were 23 +/- 0.67 years of age and weighed 91.2 +/- 3.14 kg. Each subject was evaluated utilizing a Biodex Isokinetic Dynamometer. Isokinetic internal and external concentric strength was assessed at 90 degrees of shoulder abduction and 90 degrees of elbow flexion at 300 and 450 degrees .s(-1) at each time point. A repeated-measures analysis of variance statistical analysis was performed using SPSS software. All data are reported as mean +/- SEM. Mean internal peak torques at 300 and 450 degrees .s(-1) preseason, midseason, and postseason were 50.66 +/- 2.27, 49.70 +/- 2.54, and 51.70 +/- 2.94 N.m and 37.14 +/- 2.54, 37.36 +/- 2.74, and 38.26 +/- 2.50 N.m, respectively. Mean external peak torques at 300 and 450 degrees .s(-1) preseason, midseason, and postseason were 30.16 +/- 1.69, 29.50 +/- 2.22, and 29.79 +/- 2.08 N.m and 17.68 +/- 2.15, 16.89 +/- 2.46, and 18.20 +/- 2.35 N.m, respectively. There were no differences in isokinetic internal or external concentric shoulder rotational mean peak torque of Division II pitchers at any speed tested or time point examined.

Adult↗
PubMed2006

Time domain analysis of the signal averaged electrocardiogram to detect late potentials in heart failure patients with different etiologies.

OBJECTIVE: To evaluate the frequency, clinical correlations and prognosis influence of late potentials on the of heart failure patients with different etiologies using the signal averaged electrocardiogram. METHODS: A 42 month study of the signal averaged electrocardiograms of 288 heart failure patients with different etiologies was conducted. The group of patients included 215 males (74.65%) and 73 females (25.35%) between the ages of 16 and 70 (mean 51.5, standard deviation 11.24). The heart failure etiologies were: hypertensive heart disease (78 patients, 27.1%); idiopathic dilated cardiomyopathy (73 patients, 25.4%); ischemic cardiomyopathy (65 patients, 22.6%); Chagas disease (42 patients, 14.6%); alcoholic cardiomyopathy (9 patients, 3.1%); peripartum cardiomyopathy (6 patients, 2.1%); valvular heart disease (2 patients, 4.2%) and viral myocarditis (3 patients, 1.04%). The variables included the duration of the standard QRS complex, duration of the filtered QRS complex, duration of the signal below 40 microV and the root mean square of the last 40 ms which were analyzed in regard to age, gender, etiology and mortality as well as the findings of the 12-lead electrocardiogram at rest, echocardiogram and ambulatory electrocardiogram. The statistical analysis tests used were: the Fisher exact probability test, Students t-test, Mann Whitney test, variance analysis, Log-Hank and the Kaplan-Meyer method. RESULTS: Late potentials were diagnosed in 90 patients (31.3%) and there was no association with the etiologies. The presence of this condition is associated with: a lower maximum oxygen uptake during the ergospirometry (p=0.001); sustained and non-sustained ventricular tachycardia during Holter monitoring (p=0.001), sudden death and mortality (p<0.05). Patients that did not present late potentials had a higher overlife rate. CONCLUSION: The presence of late potentials was not associated with the etiologies and proved to be an indication of a worse prognosis.

Adolescent↗
PubMed2002

Macrophage subpopulations in gingival overgrowth induced by nifedipine and immunosuppressive medication.

BACKGROUND: The immunomodulating effects of both immunosuppressive and nifedipine medication have been associated with drug-induced gingival overgrowth. The aim of the study reported here was to evaluate the presence of macrophage subpopulations in normal human gingiva and in gingival overgrowth induced by nifedipine and immunosuppressive medication. METHODS: Gingival samples were taken from 11 nifedipine-medicated cardiac outpatients (nifedipine group), 11 triple-medicated organ-transplant recipients also taking nifedipine (immunosuppression plus nifedipine group), 12 triple-medicated organ-transplant recipients (immunosuppression group), and 20 generally healthy individuals (control group). Cryostat sections were stained with mAbs for inflammatory 27E10, reparative RM3/1, and resident 25F9 macrophages using an avidin-biotin enzyme complex method. Total numbers of mAb-labeled cells were determined in connective tissue beneath sulcular epithelium, connective tissue beneath oral epithelium, and middle connective tissue. Expression of 27E10 was determined in keratinocytes in the oral epithelium. Statistics analyses were undertaken using the chi-square test, the Mann-Whitney U test, the independent samples t test, analysis of variance, and analysis of covariance. RESULTS: Greater numbers of inflammatory 27E10-positive macrophages were found in all 3 medicated groups and counting zones than in the control group except in connective tissue beneath sulcular epithelium in the immunosuppression group. The incidence of specimens expressing 27E10 antigen throughout the oral epithelium was significantly higher in the immunosuppression group (8 of 12) than in the control group (4 of 20) and the nifedipine group (2 of 11). Numbers of reparative RM3/1-positive macrophages were significantly greater in the immunosuppression group in connective tissue beneath oral epithelium than in the control group. The effect was markedly associated with degree of inflammation. Numbers of resident 25F9-positive macrophages were lower in connective tissue beneath sulcular epithelium in the immunosuppression group, and higher in middle connective tissue in the nifedipine group than in the control group. CONCLUSION: Our results show that the nature of drug-induced gingival overgrowth differs somewhat between immunosuppressive and nifedipine medications.

Adult↗
PubMed2004

Effects of tumor necrosis factor-alpha inhibitors pentoxifylline and thalidomide on alveolar bone loss in short-term experimental periodontal disease in rats.

BACKGROUND: Pentoxifylline (PTX) and thalidomide (TLD) have been shown to inhibit cytokine synthesis, mainly tumor necrosis factor (TNF)-alpha, in different inflammatory conditions. We studied the effects of these cytokine inhibitors in an experimental model of periodontitis. METHODS: Wistar rats were subjected to a ligature placement around the second upper right molars. Alveolar bone loss was evaluated by the sum of the distances between the cusp tip and the alveolar bone along the axis of each molar root, subtracting from the contralateral side. Histopathological analysis was based on cell influx, amount of alveolar bone, and cementum integrity. Animals were weighed daily, and total and differential peripheral white blood cell counts were performed at 6 hours and 1, 7, and 11 days after induction of periodontitis. Groups were treated with saline (positive control), PTX, or TLD 1 hour before and daily up to 11 days after induction of periodontitis. RESULTS: Alveolar bone loss was inhibited 42%, 54%, and 69% by PTX at 5, 15, and 45 mg/kg, and 25%, 25%, 42%, and 54% by TLD at 5, 15, 45, and 90 mg/kg, respectively, as compared to the control (P < 0.05; analysis of variance). Histological analysis showed that PTX and TLD reduced cell influx and alveolar bone and cementum destruction. PTX and TLD also reversed peripheral lymphomonocytosis but not weight loss, as compared to controls. These data showed that both PTX and TLD reduced alveolar bone loss in periodontitis. CONCLUSION: The data showed a protective effect of PTX and TLD on experimental periodontitis, suggesting a role for TNF-alpha in the pathophysiology of periodontitis.

Alveolar Bone Loss↗
PubMed2004

A multicenter comparative study of two root coverage procedures: coronally advanced flap with addition of enamel matrix proteins and subpedicle connective tissue graft.

BACKGROUND: Free grafts, pedicle flaps, and barrier membranes have been used to cover exposed root surfaces. The aim of the present study was to evaluate the clinical efficacy of a coronally advanced flap procedure with the additional use of enamel matrix protein derivative (EMD) to treat gingival recession and to compare it to the subpedicle connective tissue graft procedure (CTG). METHODS: The study was conducted in six different periodontal clinics. Miller Class I or II buccal recession type defects in the anterior or premolar teeth were treated in 70 consecutive patients, 30 with EMD and 40 with CTG. At baseline and 6 and 12 months post-surgical treatment, vertical recession defect, defined as the distance from cemento-enamel junction to gingival margin; width of keratinized tissue; and probing depth were recorded and the percentage of coverage of the original defect was calculated. Statistical analyses consisted of t-test, analysis of variance, and analysis of covariance. RESULTS: At 6 months, percent of root coverage was 77.4% +/- 11.92% in EMD and 84.1% +/- 11.97% in CTG (statistically significant at P = 0.024). At 12 months, percent of root coverage in EMD was 71.7% +/- 16.14% and 87.0% +/- 12.22% in CTG; again, differences between groups were statistically significant (P < 0.001). Differences between the 6- and 12-month vertical recession defect and percent of root coverage recordings within each group were also statistically significant. CONCLUSIONS: The connective tissue graft procedure was superior to the coronally positioned flap with the addition of enamel matrix proteins derivative in percentage of coverage and increase in width of keratinized tissue. The EMD procedure is a predictable treatment for root coverage that is relatively easy to perform and presents low patient morbidity, and is appropriate especially where a substantial increase in the width of keratinized tissue is not of prime importance.

Adolescent↗
PubMed2002

[Comparative study of the biological utilization of beta-carotene from synthetic and natural sources in rats].

The purpose of this study was to evaluate the change in concentration of retinol and beta-carotene (BC) in blood serum and liver tissue of rats, after supplementation with synthetic BC and commonly consumed carotenoid-rich vegetables (carrot and spinach). Weanling male Wistar rats were randomly assigned in four groups of 16 rats each. The four groups of rats were supplemented according to the following feeding treatments: 1) Control group (0G), 0.2 mL corn oil; 2) Pure BC group (BCG), 60 micrograms RE in 0.2 mL corn oil; 3) Carrot group (CG), 60 micrograms RE in 0.2 mL corn oil; 4) Spinach group (SG), 60 micrograms RE in 0.2 mL corn oil. Analysis of retinol and BC contents in serum and liver was performed by HPLC procedures. The variance analysis showed no significant differences (a = 0.05) in the increase of weight of the animals and in the increase of retinol and BC levels in serum and in liver of the four treatments during the four weeks of supplementation. The correlation analysis between levels of retinol and BC in serum and in liver showed no relation between these two parameters. A regression analysis of liver BC levels in the four treatments showed the following slopes of the regression lines: BCG, 0.909; CG, 0.451; SG, 0.444, and 0G, 0.203. These results indicate that the highest BC absorption was in the BCG treatment, whereas the BC absorption in the CG and SG treatments was approximately one half.

Animals↗
PubMed1992

[Analysis on birth time of 4636 babies with circular distribution method in Shijiazhuang prefecture].

The study adopts circular distribution method and periodic regression technology with cosine curve to make statistic analysis. According to the result of the statistic by season, among 4,636 babies of natural parturition from 1985 to 1988, the angle even value is 272.91 degrees, a = 0.05, by evenness examination, which indicates the tendency of concentration. The further periodic regression analysis gives out an equation: ŷ = 289.75 + 48.68 cos (wti-272.91), determination coefficient R2 = 0.56, and variance analysis concludes F = 8.35, P less than 0.01. The fitting result is satisfied, which points out that the birth time season waves in a year's period and the birth rate is high in winter. While the statistic by month, the angle even value is 338.40 degrees, a = 0.01, ŷ = 96.58 + 19.82 cos (wti-338.40), R2 = 0.42, F = 15.28, P less than 0.01, which still indicate that the birth time has a year's periodic fluctuation, with its peak on December 8. As for the statistic by day in each month, the angle even value is 213.86 degrees, evenness examination P greater than 0.05, indicating no monthly periodic fluctuation and no peak on 1st and 15th of lunar year, while the statistic by birth o'clock in a day, the angle even value is 117.31 degrees, P greater than 0.05, no day and night rhythm.

Chi-Square Distribution↗
PubMedDate not supplied

[Enteral supplements: dietary supplements or substitutes?].

OBJECTIVE: To assess the use of oral nutritional supplements analyzing the reason for prescription and its implication in caloric-protein intake. SETTING: study performed at a university hospital of 350 beds with medical and surgical specialties. SUBJECTS, PATIENTS: Patients inclusion was done by selecting all starting oral nutritional supplement prescription. Exclusion criteria were being younger than 18 years, being admitted to the Intensive Care Unit, having cognition or communication impairments, being on concomitant parenteral nutrition or requiring complete enteral diet, and/or using nasogastric tube for feeding. We also excluded special enteral diets, specifically designed for certain conditions. INTERVENTIONS: One-year long prospective study on prescription of oral nutritional supplements. Through clinical chart review and personal interview, we recorded demographic data, nutritional parameters, characteristics of the diet and supplement, and caloricprotein intake prescribed and ingested. The data were introduced in an Access97 database and processed by means of SPSS software for Windows. We performed a descriptive study of quantitative and qualitative variables, a chi2 analysis between qualitative variables, and a comparative analysis between means of all paired data by means of the student's t test, and variance analysis between quantitative variables. The significance level was set at p < 0.05. RESULTS: we were only able to analyze 77 out of 130 prescriptions for nutritional supplements since we could not adequately interview the remaining patients, mainly due to neurological impairments. Mean age was 74.8 years (SD = 12) and 50.6% were women. The departments prescribing the highest number of supplements were hematology (22.1%) and internal medicine (20.8%). GI neoplasm was the most frequent diagnosis at admission (27.3%). The most frequent indication was kwashiorkor (45.5%), with 15.6% of patients being well nourished. Mean therapy duration was 11 days (SD = 11.1), and the main reason for termination was hospital discharge (70.1%). The supplement was concomitantly prescribed with the meals in 70.6% of the cases, and more than half of the patients (70.1%) liked it, the most frequently prescribed was as a cream (61%) and the best accepted being as a liquid (78%). The average daily caloric load ingested with the foods of the hospital diet was similar between the first an third days of supplement prescription (p = 0.879) and the first and seventh days (p = 0.499). So happened when analyzing protein intake. With the supplement administration, there was a significant increase in patients' caloric intake from 310 Kcal at the third day to 337 Kcal at the seventh day (p < 0.0005) in both cases. Similar results were obtained when assessing total protein load ingested (p < 0.0005). CONCLUSIONS: Nutritional supplements are correctly used in most of the cases. They allow for a significant increase in the protein-caloric intake with no modification of hospital diet, becoming an appropriate nutritional source when the diet is insufficient.

Aged↗
PubMed1986

Comparative genetic variance and heritability of dental occlusal variables in U.S. and Northwest Indian twins.

Genetic variance analysis of 15 dental occlusal and arch variables is based on cross-cultural comparison of twin variances (U.S. Whites and Northwest Indian Punjabis). Both samples exhibit high genetic versus environmental partition of variance. However, monozygotes and dizygotes have unequal variance, which invalidates conventional genetic variance ratios. The pattern of environmental biases on the zygosities is quite different in the two groups. Revised estimates that acknowledge zygosity heterogeneity (hence unequal environmental influences) are generally much lower for occlusal traits, whereas arch size measurements are unaffected.

Adolescent↗
PubMed1992

Potential improvements in rate of genetic gain from marker-assisted selection in dairy cattle breeding schemes.

The value of marker-assisted selection in dairy cattle breeding schemes is predicted by a deterministic model. In these schemes, associations between markers and milk production were assessed from production records of daughters of a grandsire by a multiple regression model with random marker effects. By tracing markers from the grandsire to grandoffspring, deviations of grandoffspring from their full-sib family mean were predicted. Predictions of the within-family variance of the grandoffspring accounted for by markers amounted to up to 13.3%. This figure decreased when the number of daughters of the grandsire analyzed decreased and, less markedly, when the distance between flanking markers increased. Prediction of within-family deviations hardly improved rates of genetic gain in conventional progeny testing schemes; equal numbers of young bulls were born annually. Genetic gain and improvement of genetic gain because of prediction of within-family deviations were much higher in nucleus schemes. In these shemes, with short optimized generation intervals, conventional selection was mainly for pedigree information and did not use the within-family variance. Analysis of highly polymorphic markers in daughters of both grandsires accounted for 4.1 to 13.3% of the within-family variance, which increased rates of gain by 9.5 to 25.8% and 7.7 to 22.4% in open and closed nucleus schemes, respectively. Risk of breeding schemes, measured by the variance of the selection response, was not increased by the use of markers.

Animals↗
PubMed2002

[Studies of single nucleotide polymorphism of PPAR gene and its associations with fattiness trait in chicken].

In this experiment, the AA broiler fat traits and three Chinese special breeds (Shiqiza, Beijing youji and Baier) were used to study the effect of PPAR-alpha gene on fat trait. Coding region of the gene was amplified by seven pairs of primers, and then single nucleotide polymorphisms (SNPs) were detected by the technique of single strand conformation polymorphism (SSCP) and finally confirmed by sequencing. One nucleotide variation was found, the result of chi 2 analysis showed that the distribution of three genotypes was very different among different breeds(P < 0.01). The result of variance analysis showed that the birds with BB genotype had a higher abdominal fat weight than the birds with other genotypes (AA and AB). It implied that PPAR-alpha gene could be a candidate locus or linked to a major gene to significantly affect abdominal fat traits in chicken.

Abdomen↗