PubMed Health⌕ Search

Biomedical subjects

G J King

Publications and source records attributed to G J King.

At least 19 recordsLinked to original sources
PubMed1999

Association of lipoprotein lipase gene polymorphisms with coronary artery disease.

OBJECTIVES: The purpose of this study was to test whether the HindIII (+) and PvuII (-) or (+) restriction enzyme-defined alleles are associated with angiographic coronary artery disease (CAD). BACKGROUND: Lipoprotein lipase (LPL) plays a central role in lipid metabolism, hydrolyzing triglyceride in chylomicrons and very low density lipoproteins. Polymorphic variants of the LPL gene are common and might affect risk of CAD. METHODS: Blood was drawn from 725 patients undergoing coronary angiography. Leukocyte deoxyribonucleic acid segments containing the genomic sites were amplified by the polymerase chain reaction and digested, and polymorphisms were identified after electrophoresis in 1.5% agarose gel. RESULTS: In no-CAD control subjects (n = 168), HindIII (-) and (+) allelic frequencies were 28.6% and 71.4%, and (-) and (+) alleles were carried by 44.0% and 86.9% of subjects, respectively. Control PvuII (-) and (+) allelic frequencies were 41.7% and 58.3%, and (-) and (+) alleles were carried by 64.3% and 81.0%, respectively. In CAD patients (>60% stenosis; n = 483), HindIII (+) allelic carriage was increased (93.8% of patients, odds ratio [OR] = 2.28, confidence interval [CI] 1.27 to 4.00). Also, PvuII (-) allelic carriage tended to be more frequent in CAD patients (OR = 1.33, CI 0.92 to 1.93). Adjusted for six CAD risk factors and the other polymorphism, HindIII (+) carriage was associated with an OR = 2.86, CI 1.50 to 5.42, p = 0.0014, and PvulI (-) carriage, OR = 1.42, CI 0.95 to 2.12, p = 0.09. The two polymorphisms were in strong linkage disequilibrium, and a haplotype association was suggested. CONCLUSIONS: The common LPL polymorphic allele, HindIII (+), is moderately associated with CAD, and the PvuII (-) allele is modestly associated (trend). Genetic variants of LPL deserve further evaluation as risk factors for CAD.

Adolescent↗
PubMed1999

Acute elbow dislocations: simple and complex.

The elbow is the second most common joint dislocated in adults. Up to 20% of dislocations are associated with fractures. Treatment principles are reduction of the joint, stabilization of associated fractures, and early motion. Ligament repairs or reconstruction and hinged external fixators are necessary in some cases to restore stability for early motion. In general, simple dislocations have a better prognosis than complex dislocations (fracture-dislocations).

Acute Disease↗
PubMed1999

Associations between a polymorphism in the gene encoding glycoprotein IIIa and myocardial infarction or coronary artery disease.

OBJECTIVES: The purpose of this study was to determine whether a common variant (PIA2) of the membrane glycoprotein (GP) IIIa gene is associated with myocardial infarction (MI) or coronary artery disease (CAD). BACKGROUND: Platelet GP IIb/IIIa is believed to play a central role in MI, binding fibrinogen, cross-linking platelets and initiating thrombus formation. Genetically determined differences in binding properties of GP IIb/IIIa might result in changes in platelet activation or aggregation and affect the risk of MI or CAD. METHODS: To determine associations (odds ratios [OR] > or =1.5 to 2.0) of genotype with MI or CAD, blood was drawn from 791 patients (pt) undergoing angiography. A 266 base pair fragment of the GP IIIa gene was amplified by the polymerase chain reaction and digested with the MspI restriction enzyme. Genotypes were identified after electrophoresis of digestion products in 1.5% agarose gel. RESULTS: Of the 791 pt, 225 had acute (n = 143) or previous MI, and 276 did not have MI or unstable angina. The PI(A2) allele was carried by 33.8% of MI pt versus 26.9% of no-MI control subjects, OR = 1.39 (95% CI, 0.95 to 2.04, p = 0.09). Angiographically, 549 pt had severe (>60% coronary stenosis) CAD, and 170 had normal coronary arteries (<10% stenosis). The PI(A2) allele was found in 31.0% of CAD pt versus 28.2% of no-CAD control subjects, OR = 1.14 (CI, 0.78 to 1.67, p = 0.50). When adjusted for six standard risk factors, ORs were 1.47 (CI, 0.98 to 2.20, p = 0.062) for MI and 1.20 (CI, 0.80 to 1.81, p = 0.38) for CAD. CONCLUSIONS: The PI(A2) variant of the gene encoding GP IIIa is modestly associated (OR approximately 1.5) with nonfatal MI but shows little if any association with CAD per se.

Adolescent↗
PubMed1999

Hepatic lipidosis associated with cobalt deficiency in Omani goats.

Livers from 36 of 684 (5.3%) apparently healthy goats examined at an abattoir in the greater Muscat area of Oman exhibited gross pathological findings characterized by extremely pale, friable, fatty livers encompassing the entire organ. Histopathologically, diffuse hepatic lipidosis and occasional bile duct proliferation were observed. Periodic acid Schiff-positive, diastase-resistant pigment was observed in the macrophages lining the sinusoids. These histopathological lesions were consistent with those characteristic of ovine white liver disease. Cobalt analysis revealed that normal livers had six times more cobalt and a 3-fold less fat content than those measured in the fatty livers. This is the first report of an association between cobalt deficiency and hepatic lipidosis in Omani goats.

Animals↗
PubMed1999

Evaluation of orthodontists' perception of treatment need and the peer assessment rating (PAR) index.

This paper examines the relationship between orthodontists' subjective assessment of treatment need and objective measurements obtained during standardized intra- and extraoral examinations. Logistic regression modeling was used to develop predictive models of treatment need. Data were obtained from 1155 eighth-grade students by four orthodontists who used standardized examination forms to assess demographics, trauma, skeletal relationships, morphologic malocclusion traits, and mandibular function. At the conclusion of the examination, the orthodontist rated the subjective treatment need as none, elective, recommended, soon, or immediate. For some analyses, the categories were collapsed to represent no need and need. The peer assessment rating (PAR) index (American validated version) was computed from the clinical exam findings and scoring of dental models; PAR scores were used to document malocclusion severity and treatment difficulty. Spearman rank correlation coefficients quantified the relationship between PAR scores and need categories. Logistic regression analysis modeled treatment need using components of the PAR index as well as other variables. The components of these models, as well as sensitivity and specificity, were compared with malocclusion severity/treatment difficulty scores obtained from malocclusion assessments using the PAR index. The five subjective treatment need categories and the PAR index scores were significantly correlated (rho = 0.62, p<0.001). Significant differences were detected between the need and no need groups for all PAR components (p<0.001). PAR index scores and predicted probabilities from logistic regression models performed equally well for classification purposes (no need, need). The data suggest that the PAR index is highly correlated with orthodontists' subjective assessment of treatment need when that assessment is made in the absence of financial considerations and patient desires.

Adolescent↗
PubMed1998

Angiotensin-converting enzyme genotypes and risk for myocardial infarction in women.

OBJECTIVES: We tested for an association between the angiotensin-converting enzyme (ACE) DD polymorphic genotype and myocardial infarction (MI) in a sample group composed exclusively of women. BACKGROUND: The human ACE gene occurs with either an insertion (I allele) or a deletion (D allele) of a 287-base pair (bp) Alu element. Part of the variance in serum ACE levels may be accounted for by this polymorphism. Also, the DD genotype has been associated with an increased risk of MI in predominantly male populations. However, the risk in women is poorly defined. METHODS: Genomic DNA was extracted from buffy coat blood using a phenol/chloroform method. Angiotensin-converting enzyme alleles were identified using primers to bracket the insertion region in intron 16. Amplification using polymerase chain reaction allowed identification of a 490-bp (I allele) or a 190-bp (D allele) product, or both. RESULTS: Allelic and genotypic frequencies in control subjects were similar to those reported in mostly male populations, and frequencies of genotypes were in the Hardy-Weinberg equilibrium. In contrast, the distribution of genotypes in patients with MI diverged from the equilibrium. Specifically, DD genotypic frequency was increased in women with (n = 141) versus without (n = 338) a previous MI (39% vs. 29%, odds ratio [OR] 1.54, 95% confidence interval 1.02 to 2.32, p < 0.04). Risk was particularly increased in women <60 years old (OR 2.04, p < 0.05). In contrast, the DD genotype did not predict angiographic coronary artery disease. CONCLUSIONS: Consistent with findings in male-dominated populations, a modest association of the ACE DD genotype with MI was found in women. The basis for this association requires further study.

Aged↗
PubMed1998

Effect of orthodontic appliance reactivation during the period of peak expansion in the osteoclast population.

BACKGROUND: Delays in the appearance ofosteoclasts at compression sites occur following orthodontic appliance reactivation when this is done during the period of osteoclast recruitment. This study examined changes in alveolar bone after appliance reactivation at a time coinciding with the peak expansion of the osteoclast population following the first appliance activation. METHODS: Orthodontic appliances were activated with 40 g on maxillary molars followed by a reactivation with the same force after 4 days in one group and sham reactivation in the other. Rats were killed at 0, 1, 3, 6, and 10 days thereafter. Orthodontic movement was measured cephalometrically. TRAP and interleukin-1 alpha (IL-1alpha) were measured biochemically, and changes in osteoclasts and root resorption were assessed at both compression and tension sites histomorphometrically. RESULTS: Teeth in the reactivated group displayed more initial displacement than controls but no more tooth movement 10 days following appliance reactivation. Also, increases in osteoclast numbers and surface percent, as well as alveolar bone Tartrate-resistant acid phosphatase (TRAP), became evident in the treated animals only 10 days after reactivation. However, IL-1alpha was elevated in alveolar bone within 1 hr following appliance reactivation but returned to baseline by day 1. There were no treatment-related difference in nuclear number per osteoclast or trabecular surface per osteoclast. Significant treatment-related increases in root resorption were evident at compression sites by day 10. CONCLUSIONS: These findings indicate that after appliance reactivation during the height of osteoclastic stimulation, a second cohort of osteoclasts can be recruited, but only after a delay of several days. This delay is not due to a failure to produce IL-1alpha in the tissues.

Acid Phosphatase↗
PubMed1998

A biomechanical analysis of intrascaphoid compression using the Herbert scaphoid screw system. An in vitro cadaveric study.

The purpose of this study was to evaluate the compressive capabilities of the Herbert scaphoid screw system. A transverse osteotomy was performed at the waist of eight scaphoids removing a 3 mm wafer of bone. A custom-designed load washer was inserted within this defect to measure intrascaphoid compression during Huene guide application, during screw insertion, after screw insertion and after guide release. The intrascaphoid compression was noted to peak during screw insertion; however it dramatically decreased without any clinical subjective evidence of decreased insertional torque by the surgeon. The average final compression as a percentage of maximal compression was 38 (SD 26) %.

Aged↗
PubMed1998

Load relaxation and forces with activity in Hoffman external fixators: a clinical study in patients with Colles' fractures.

A small-frame Hoffman external fixation bar instrumented with strain gauges to quantify bending and torsional forces was applied to 4 patients with a displaced metaphyseal fracture of the distal radius. Measurements were taken during surgery as well as at 1, 3, and 6 weeks after surgery during activities of daily living and hand therapy mobilization. Radiographs also were taken before and after reduction and at each subsequent visit. Force decay occurred after reduction of the fracture, averaging only 26% of the initial distraction forces by 5 minutes. These forces plateaued and did not significantly change over the subsequent 40-minute observation period. There was no correlation between carpal height index and the forces measured in the external fixator. Significant changes in external fixator forces were measured during activities of daily living and hand therapy mobilization, but these returned to baseline after the activities were performed. The most provocative activities studied were twisting a doorknob and lifting heavy objects. These activities should be performed with caution by patients with unstable distal radial fractures.

Activities of Daily Living↗
PubMed1998

Later orthodontic appliance reactivation stimulates immediate appearance of osteoclasts and linear tooth movement.

BACKGROUND: Delays in the appearance of osteoclasts at compression sites occur after orthodontic appliance reactivation, when this is done during both the period of osteoclast recruitment and the peak expansion in the osteoclast population. This experiment examines osteoclasts and tooth movement in alveolar bone after appliance reactivation coinciding with alveolar bone formation and the time when reactivation osteoclasts first appear (ie, 10 days after initial appliance activation). METHODS: Bilateral orthodontic appliances were activated to mesially tip maxillary molars with 40 cN in 144 rats. After 10 days, all rats were randomized into two groups of 72. Group I had appliances reactivated in precisely the same manner as the first activation. Group II had appliances sham-reactivated. Nine to 12 rats were then sacrificed at 1, 3, 5, 7, 10, and 14 days in both groups (eg, day 1 represents an interval of 11 days after the first appliance activation and 1 day after either sham or real reactivation). Orthodontic movement was measured cephalometrically; changes in osteoclasts and root resorption were assessed at both compression and tension sites histomorphometrically. RESULTS: Teeth in the reactivated group (Group I) displayed linear tooth movement (62.6 micrometers/day), and 0.9 mm tooth movement by day 10. Significant increases in osteoclast numbers, osteoclast surface percentage, and surface per individual osteoclast were evident in these animals by 1 day postreactivation (P <.01). Significant treatment-related increases in root resorption were not evident at compression sites at any time. CONCLUSIONS: These findings indicate that, after appliance reactivation during the time when reactivation osteoclasts appear, a second cohort of osteoclasts can be recruited immediately, along with immediate and substantial tooth movement and no greater risk of root resorption.

Alveolar Process↗
PubMed1998

Anteroposterior skeletal and dental changes after early Class II treatment with bionators and headgear.

In this study we examined anteroposterior cephalometric changes in children enrolled in a randomized controlled trial of early treatment for Class II malocclusion. Children, aged 9.6 +/- 0.8 years at the start of study, were randomly assigned to control (n = 81), bionator (n = 78), and headgear/biteplane (n = 90) treatments. Cephalograms were obtained initially, after Class I molars were obtained or 2 years had elapsed, after an additional 6 months during which treated subjects were randomized to retention or no retention and after a final 6 months without appliances. Calibrated examiners, blinded to group, used Johnston's analysis to measure anteroposterior cephalometric changes. Statistical analysis was used to determine annual skeletal and dental changes during treatment, retention, and follow-up, and overall. Our data reveal that both bionator and head-gear treatments corrected Class II molar relationships, reduced overjets and apical base discrepancies, and caused posterior maxillary tooth movement. The skeletal changes, largely attributable to enhanced mandibular growth in both headgear and bionator subjects, were stable a year after the end of treatment, but dental movements relapsed.

Activator Appliances↗
PubMed1998

Prevalence of orthodontic asymmetries.

Epidemiological studies of the occlusal status of the US population do not include the prevalence of orthodontic asymmetries. To estimate the magnitude of dental and facial asymmetries in adolescents with no history of orthodontic treatment, data were analyzed from two mass orthodontic screenings that had been conducted on public schoolchildren in Florida. An analysis of orthodontic records of patients in treatment at the Virginia Commonwealth University graduate orthodontic clinic provided prevalence data on dental and facial asymmetries in a population of orthodontic patients. In the Florida studies, the two screenings yielded 5,817 untreated children (mean age, 9.3 +/- 0.8 years) and 861 untreated children (mean age, 14.4 +/- 0.5 years). Sagittal molar asymmetry was found in 30% of the children in the first screening and in 23% in the second screening. Additional asymmetry assessments in the second screening showed 12% facial asymmetry and 21% noncoincidence of dental midlines. Among orthodontic patients, the most common asymmetry trait was mandibular midline deviation from the facial midline. This occurred in 62% of patients, followed, in descending order of frequency, by lack of dental midline coincidence (46%), maxillary midline deviation from the facial midline (39%), molar classification asymmetry (22%), maxillary occlusal asymmetry (20%), mandibular occlusal asymmetry (18%), facial asymmetry (6%), chin deviation (4%), and nose deviation (3%).

Adolescent↗
PubMed1998

Occlusal traits and perception of orthodontic need in eighth grade students.

In 1994, 1155 eight-grade students in Alachua County, Fla., were asked about self-perception of and level of concern for their occlusal status. Clinical assessments of orthodontic parameters were also recorded. Twenty-five percent of the students had a history of orthodontic treatment. Of the remaining students who had no history of orthodontic treatment, 74% reported satisfaction with the way their teeth looked, 64% expressed no perceived need for braces, and 57% were judged clinically to have optional or no orthodontic needs. Sex, soft tissue profile, overjet, anterior crowding, and molar classification were significantly associated with the perception of need for braces while race and overbite were not. Clinical judgment of orthodontic need differed significantly among levels of satisfaction with teeth. Eighth graders with no history of orthodontic treatment were generally satisfied with the appearance of their teeth and perceived less need for braces than clinicians.

Adolescent↗
PubMed1998

Early treatment of Class II, division 1 malocclusion--comparison of alternative treatment modalities.

The purpose of this paper was to compare the findings from three randomized clinical trials that investigated alternative treatments of Class II, division 1 malocclusion in young children. The trials were conducted at the University of North Carolina, the University of Florida, and the University of Pennsylvania. The appliances investigated in each center were a functional appliance versus a headgear. Variations in the specific aims and the working hypotheses were noted. The types of appliances, length of treatment, and methods of evaluation were also different. A general comparison of selected clinically relevant findings reveals similarities and differences in conclusions, but underlines the importance of assessing each study on the basis of its original hypothesis. The separate and combined contribution of these studies to the state of knowledge and research is discussed.

Child↗
PubMed1998

Management of recurrent, complex instability of the elbow with a hinged external fixator.

We have treated 16 patients with recurrent complex elbow instability using a hinged external fixator. All patients had instability, dislocation or subluxation of the ulnohumeral joint. The injuries were open in eight patients and were associated with 20 other fractures and five peripheral nerve injuries. Two patients had received initial treatment from us; 14 had previously had a mean of 2.1 unsuccessful surgical procedures (1 to 6). The fixator was applied at a mean of 4.8 weeks (0 to 9) after the injury and remained on the elbow for a mean of 8.5 weeks (6 to 11). After treatment we found the mean range of flexion-extension to be 105 degrees (65 to 140). At a final follow-up of 23 months (14 to 40), the mean Morrey score was 84 (49 to 96): this translated into one poor, three fair, ten good and two excellent results. Complications included one fractured humeral pin, one temporary palsy of the radial nerve, one recurrent instability, one wound infection, one severe pin-track infection and one patient with reflex sympathetic dystrophy. Although technically demanding, the use of the fixator is an important advance in the management of recurrent complex elbow instability after failure of conventional treatment.

Adult↗
PubMed1998

Evaluation of overall reproductive performance of dairy herds.

Reproductive efficiency was assessed in 106 commercial dairy herds in Ontario. Herds that were similar in historical calving interval or projected calving interval varied widely in reproductive culling rate. The correlation between the reproductive culling rate and the historic calving interval and between the reproductive culling rate and the projected calving interval were -0.23 and were not significant. The coefficient of variation associated with the reproductive culling rate (75.7%) was much higher than that of the historical calving interval (3.8%) or the projected calving interval (4.5%). The repeatability of the reproductive culling rate (0.26) was much lower than that of the historical calving interval (0.81) or the projected calving interval (0.60) because culling rate was not only influenced by the overall herd reproductive performance, but also by the differences in the maximal allowable days open for rebreeding and the estimation of which cows were culled for reproductive failure. Additionally, a high coefficient of variation for the reproductive culling rate is unavoidable because this variable has a binomial distribution and a low mean value (7.5%). These disadvantages are not sufficient to exclude this measure from a comprehensive assessment of overall herd reproductive performance. The projected calving interval and the reproductive culling rate can be combined into the adjusted calving interval and thus interpreted jointly. On 40.5% of the farms providing data for this study, fertility assessment based on the projected calving interval indicated better reproductive performance than that based on adjusted calving interval. Hence, the assessment of herd fertility on the basis of projected calving interval can lead to a different and erroneous conclusion regarding the level of herd fertility than that obtained with the evaluation based on adjusted calving interval.

Animals↗