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Objectives: The aim of this clinical study was to determine the effectiveness of progressive loading procedures on preserving crestal bone height and improving peri-implant bone density around maxillary implants restored with single premolar crowns by an accurate longitudinal radiographic assessment technique., Materials and Methods: Twenty-three HA-coated, endosseous dental implants were placed in 20 subjects and permitted to heal for 5 months before surgical uncovering. The implants were randomly assigned to either an experimental or control group. Following a conventional healing period, the control group implants were restored with a metal ceramic crown and the experimental group implants underwent a progressive loading protocol. The experimental group was progressively loaded by increasing the height of the occlusal table in increments from a state of infraocclusion to full occlusion by adding acrylic resin to a heat-processed acrylic crown. The progressively loaded crowns were placed in infraocclusion for the first 2 months, light occlusion for the second 2 months, and full occlusion for the third 2 months. At this point, a metal ceramic crown replaced the acrylic crown. Standardized radiographs of each implant were made at the time of restoration, then after 2, 4, 6, 9, and 12 months of function. Digital image analysis and digital subtraction radiography were used to measure changes in crestal bone height and peri-implant bone density., Results: The mean values of crestal bone height loss at 12 months were 0.2+/-0.27 mm for the progressively loaded implants and 0.59+/-0.27 for the conventionally loaded implants, and when tested with repeated-measure ANOVA across the time periods, the differences were statistically significant (P< or =0.05). The progressively loaded group showed a trend for higher bone density gain in the crestal area than the conventionally loaded group, but the conventionally loaded group showed a trend for higher bone density gain at the apex of the implants., Conclusion: The peri-implant bone around progressively loaded implants demonstrates less crestal bone loss than the bone around implants placed conventionally into full function. The peri-implant density measurements of the progressively loaded implants show continuous increase in peri-implant bone density by time.

We report scanning tunneling microscopy and low energy electron microscopy (LEEM) observations for thin films of Nb (011) of stripe-phase behavior by two variants of an O-induced reconstruction. Stripes occur for thin films but not bulk crystals. At low temperatures the less-favored variant is thermally activated as single stripes on surface heterogeneities. Near T0 = 1505 K, where the reconstruction is lifted, the stripes crowd to form a periodic array with a temperature dependent spacing. LEEM permits quantitative insight into stripe behavior and reveals novel details of stripes interacting with topographic features such as steps, facets, and dislocations.

Atrioventricular valvular regurgitation is a known complication after cardiac transplantation. In this communication, we describe a case of progressively severe tricuspid insufficiency that ultimately necessitated tricuspid valve replacement. The patient has done well clinically since valve replacement, and a postoperative cardiac catheterization demonstrated normal right heart hemodynamics. A discussion of proposed causes and a review of the literature are provided.

Echocardiographically guided endomyocardial biopsy via percutaneous right internal jugular vein puncture has been performed 98 times in six patients 5-16 years of age at our institutions. The use of this approach was extended for rejection surveillance in seven infants transplanted at 2 weeks to 15 months of age (median, 2 months; mode, 2 weeks). A total of 35 consecutive biopsies were performed under heavy sedation in these infants (lowest weight, 3.0 kg) with the use of a 5F semirigid bioptome through a 5.0-cm 5F sheath. There was no case of entrance failure. A median of four biopsies was performed on each child (range, one to 14). Four to seven tissue pieces per biopsy were obtained using an apical four-chamber view for bioptome guidance. Ten instances of clinically suspected rejection were not confirmed by biopsy, and two cases of unsuspected rejection were found. The only complication was one instance of new mild tricuspid regurgitation in this group compared with one instance of increased tricuspid regurgitation after biopsy in the older child group. These preliminary results suggest that echocardiographically guided endomyocardial biopsy from the right internal jugular approach is a reliable and safe means for rejection surveillance in the infant and young child.

Heart transplants in pediatric patients have moved from an experimental, end-stage treatment to a valuable therapy for inoperable congenital heart disease and dilated cardiomyopathies. Cardiac rejection is a frequent problem in children with heart transplants. The technical difficulties of obtaining biopsies in small children have encouraged the use of noninvasive methods of detection although endomyocardial biopsy continues to be the most reliable method of surveillance for cardiac rejection. We examined our experience over 7 years with 4 patients (ages 8 months to 10 years) who had a total of 88 endomyocardial biopsies using echocardiographic guidance. The biopsies were done using a Caves-Schultz biotome via the right internal jugular vein. Biopsies were performed in the procedure room, 61%; pediatric intensive care unit, 18%; hospital private room, 18%; and catheterization laboratory, 3% of the time. At 5.0, 6.5, or 8.5 French biotome was used depending on the size of the patient. Twelve episodes of rejection were detected in these patients. The time for venous access was 17 +/- 15 min, and the biopsies took 25 +/- 11 min using this approach. Biopsies were obtained from the right ventricular free wall, apex, and septum to detect focal rejection for a total of 4-6 tissue samples per biopsy. Neither general anesthesia nor fluoroscopy was needed for these biopsies. Costs ranged from $1120 in the patient room to $1590 in the pediatric intensive care unit. Five different biopsies using a femoral approach with fluoroscopic guidance averaged $2250 and did not include the functional assessment obtained using echocardiography. Using the echocardiogram one can see the ventricular muscle and completely avoid perforation. Thus, this technique is technically feasible in children with few complications at a reduced cost, compared to fluoroscopically guided biopsies.

The clinical profile of 23 children with congestive cardiomyopathy was reviewed to detect any factors that might be predictive for their survival. Factors examined include age at onset (less than 2 versus greater than 2 years), gender, severity of the clinical picture including data from the chest radiograph, electrocardiogram (ECG), echocardiogram, hemodynamic study and endomyocardial biopsy. Follow-up study ranged from 1 month to 14 years (mean 43 months). There were 12 survivors and 11 nonsurvivors; the 1 year mortality rate was 30% (7 of 23), and the 5 year mortality rate was 44% (10 of 23). Age at onset, gender, cardiothoracic ratio on chest radiograph, pattern of infarction, ST-T changes or arrhythmia on ECG and left ventricular end-diastolic pressure were nonpredictive of outcome. However, low shortening fraction (mean 11.5% in nonsurvivors versus 20.9% in survivors, p less than 0.01), familial cardiomyopathy and endocardial fibroelastosis indicated a very poor prognosis.

The effect of indomethacin on systolic and diastolic cardiac function was assessed in 15 premature infants. Seven infants (group 1) received indomethacin to treat a clinically significant patent ductus arteriosus (PDA), and eight infants (group 2) received indomethacin prophylactically at 24 hours of age because of their high risk for PDA. Diastolic cardiac function was assessed using instantaneous rates of change of left ventricular (LV) cavity dimension, derived from M-mode echocardiography. The maximum velocity of lengthening of the LV cavity dimension, an index of early diastolic function, fell from 63 +/- 19 mm/sec before indomethacin to 48 +/- 16 mm/sec 1 hour after indomethacin in group 1 (P less than 0.01), with the ductus still patent and the LV chamber still dilated, and also decreased in group 2, from 52 +/- 7 mm/sec to 38 +/- 6 mm/sec (P less than 0.01). This index, when normalized for loading conditions, was decreased 1 hour after indomethacin at 12 +/- 2 sec-1 and 12 +/- 1 sec-1 for groups 1 and 2, respectively, compared with values before indomethacin of 15 +/- 3 sec-1 and 15 +/- 2 sec-1. There was no effect of indomethacin on the indices of systolic function. We conclude that indomethacin decreases early diastolic function in premature infants.

Patients with tetralogy of Fallot have a 5% to 19% incidence rate of abnormal distribution of coronary arteries. These abnormalities are usually detected by angiography and influence the timing and mortality rate of surgery. This study evaluates two-dimensional echocardiography as a method of assessing coronary artery distribution in tetralogy of Fallot. Forty-five consecutive patients with tetralogy of Fallot, aged 0.1 to 20.5 years (mean 5.7 +/- 4.3), had prospective two-dimensional echocardiographic studies to examine the branching patterns of the coronary arteries and to determine the presence or absence of a branch from the right or left coronary artery that crossed the right ventricular outflow tract. The first two patients had known coronary abnormalities and served as learning models. All other echocardiographic studies were performed without knowledge of angiographic or surgical findings. Twenty-two studies were completed before coronary angiography (group A) and 23 after angiography (group B). All eight patients (18%) with coronary abnormalities were correctly identified by two-dimensional echocardiography (five in group A and three in group B). Three had bilateral anterior descending coronary arteries originating from the left and right coronary arteries, two had the anterior descending artery originating from the right coronary artery, two had a large conal branch from the right coronary artery and one had origin of both left and right coronary arteries from a single left ostium. All abnormal coronary arteries were visualized crossing the right ventricular outflow tract, whereas all 21 small conal branches from the right coronary artery were not seen in the right ventricular outflow tract.(ABSTRACT TRUNCATED AT 250 WORDS)

Developmental changes in diastolic ventricular function were assessed in 31 premature infants and in 10 normal-term infants. They were studied during the first 72 hours of life using instantaneous rates of change of left ventricular (LV) cavity dimension, derived from M-mode echocardiography. Maximal velocity of lengthening of the LV cavity was significantly lower in premature infants (38 +/- 7 mm/s) than in term infants (88 +/- 15 mm/s). This variable increased with increasing maturity over the 4 gestational age groups evaluated (r = 0.87). This index normalized for instantaneous LV dimension was lower in the most immature infants (4.5 +/- 1 s-1) than in term infants (6.8 +/- 2 s-1). Eight of the premature infants were studied serially at 1, 3 and 7 days of age. Maximal velocity of lengthening divided by stroke dimension improved from 12.9 +/- 2 s-1 at 1 day of age to 16.5 +/- 3 s-1 at 7 days. These results suggest depressed early diastolic function in premature infants.

The specificity of the persistence of antibody to the streptococcal group A carbohydrate for mitral valve disease induced by rheumatic fever was examined. Levels of the antibody were determined in serum samples of 30 patients with rheumatic mitral insufficiency, 30 patients with mitral valve prolapse, and an equal number of normal individuals and patients with congenital heart disease. Antistreptolysin titers and anti-deoxyribonuclease B titers were also assayed in all sera. There were no differences in the incidence of elevated antibody titers or in the geometric means of the antibody titers for the normal individuals, the patients with congenital heart disease, and the patients with mitral valve prolapse. In contrast, the frequency of elevated anti-streptococcal group A carbohydrate titers and the geometric means of these titers were significantly higher in the patients with rheumatic mitral valve disease than in patients with mitral valve prolapse. This confirms the specificity of the persistent elevation of anti-streptococcal group A carbohydrate to patients with mitral valve disease induced by rheumatic fever and also suggests that the persistence of this antibody in patients with rheumatic valvular disease is not a result of a functional abnormality of the mitral valve.