Percentile distributions of bone measurements in Iowa children: the Iowa Bone Development Study.

Four hundred twenty-eight white children (200 boys and 228 girls) ages 4.5-6.5 yr had spine, hip, and whole-body bone mineral density (BMD) and bone mineral content (BMC) measured by dual-energy X-ray absorptiometry(DXA) as part of the Iowa Bone Development Study. Anthropometric measurements, including height, weight, and body mass index (BMI) were determined for each child at the time the bone measurements were made. The age- and gender-specific height percentile based on the 2000 CDC Growth Charts (www.cdc.gov/growthcharts/) was determined for each child. These percentiles were used to classify children into four groups as defined by the 25th, 50th,and 75th percentile cutpoints. Percentile distributions were determined within each height quartile group to delineate percentiles (5th, 25th, 50th, 75th, 95th) for BMD and BMC. Gender differences in BMD and BMC were investigated before and after stratification into height groups. Boys had higher age-height-weight-adjusted means for most BMD and BMC measures except spine BMD. Bone measurements increased with height quartile, indicating that taller children have greater BMD and BMC compared to shorter children of the same age and gender. Within any given quartile,mean BMD and BMC measurements were similar for boys and girls, with the exception of hip BMD, for which values were consistently higher for boys (p < 0.05). In addition, whole-body BMC values were higher for boys in quartiles 1 and 3 (p < 0.05). These bone measures provide norms for young white children and serve as a reference for comparison with other racial and ethnic groups, as well as with childhood populations that are at risk for osteopenia because of chronic disease. Gender, age, and height are useful clinical predictors of BMD and BMC in young children.     

Metabolic fate of valproic acid in the rhesus monkey. Formation of a toxic metabolite, 2-n-propyl-4-pentenoic acid

The metabolic fate of an iv bolus dose (13.5 mg kg-1) of valproic acid (VPA) was studied in adult male rhesus monkeys. Renal excretion proved to be the major route of elimination of the drug and a total of 17 metabolites, accounting collectively for some 82% of the administered dose, were identified in urine by GC-MS techniques. Many of these metabolites were present largely in the form of glucuronide conjugates, as was VPA itself. The principal pathways of VPA biotransformation were, in order of decreasing quantitative importance, ester glucuronide formation, omega-oxidation, beta-oxidation and (omega-1)-hydroxylation. In addition, three mono-unsaturated metabolites, identified as (E)-delta 2-, (E)-delta 3-, and delta 4-VPA, were detected in both plasma and urine. Quantitative analysis of these unsaturated VPA metabolites indicated that the delta 4 olefin, which is known to be a potent hepatotoxic agent, was the predominant isomer of the group.     

Circulating filarial antigen in cats infected with Brugia pahangi is indicative of the presence of adult worms

Using counterimmunoelectrophoresis with rabbit antisera raised against soluble extracts of adult females of Brugia pahangi parasite antigen was detected in the serum of all cats repeatedly infected with B. pahangi. Antigen was never detected in uninfected cats. The antigen was associated with the presence of adult worms. Antigen was detected consistently in a cat that was amicrofilaraemic but at autopsy harboured only two or three adult worms. Conversely, some cats showed slowly declining numbers of microfilariae and, in these, circulating antigen declined before the number of microfilariae. Eventually no antigen was detectable in circulation whereas microfilariae, although in diminishing numbers, were still present. At autopsy no adult worms were found in these cats. Antigen also appeared in several cats before they became microfilaraemic.     

Computer simulation of the occlusal anatomy of the first mandibular molar after varying the determinants of mandibular movement in the CICERO CAD/CAM system

Static and dynamic occlusal interferences often occur in restorations. The CICERO CAD/CAM technique was used to control the occlusal dimensions of all‐ceramic restorations by setting the variables which determine the mandibular contact movements. The anatomy of the occlusal form of the (pre)molar teeth is influenced by the setting of the sagittal and transversal determinants of mandibular contact movements. In this study the variation in occlusal morphology of a high‐ and low‐limit setting of six variables was compared with an averaged setting. The settings (high, low and averaged, respectively) of the mandibular movement: the sagittal condylar (60°, 0°, 30°) and the incisal guide angle (60°, 0°, 30°) as well as the long centric articulation (1·2 mm, 0 mm, 0·6 mm) influence mainly the antero‐posterior direction, whereas the settings of Bennett movement (laterotrusion: 30°, 0°, 15°), Bennett side shift (laterotranslation: 1, 0, 0·5 mm) and the wide centric (lateral intercuspal contact area: 0·6, 0, 0·3 mm) will mainly influence the transversal direction of the mandibular movement. The influence of the variation of settings on ‘dynamic’ crown morphology as compared with the static crown morphology was studied by comparison of mesio‐distal and bucco‐lingual sections at the same occlusal position of the first lower molar design. Furthermore, the amount of material needed for the correction of the ‘static’ crown to avoid interferences in dynamic conditions was calculated. It appeared that most correction was needed for the ipsilateral settings: Bennett side shift (1·0 mm), Bennett movement (30°) and the Sag. Condylar guidance (0°) as well as the Incisal angle (0°), which could be studied in the bucco‐lingual sections. Also the Bennett side shift on the contra‐lateral side influenced the occlusal contour strongly, which could be seen in the mesio‐distal section. It was concluded that simulation of the influence of several types of determinants of mandibular movement on the three‐dimensional occlusal anatomy can be studied using the CICERO‐CAD/CAM technique. The ipsi‐ and contralateral Bennett side shift variation influenced the occlusal anatomy more than other variables.     

用Sauvegrain法测定青春期骨龄准确性的研究

背景：Sauvegrain方法是通过分析肘部X线片来评估骨龄，常用于青春期生长发育最为迅速的两年间的骨龄测定。本文旨在研究该方法的准确性以及在小儿骨科中的应用价值。 方法：Sauvegrmn法主要评估肘部的4个解剖标志点：外髁、肱骨滑车、尺骨鹰嘴突以及桡骨近端骨骺。它是一个27分制的评分系统。对上述结构所得的评分进行合计而得出一个总分，然后使用标准图表确定骨龄。让三位观察者分别利用该方法进行骨龄评估。三位观察者通过分析60个男孩和60个女孩样本左肘部的前后位和侧位X线片来测定骨龄，并将该结果与通过分析左手和腕部后前位X线片的Greulich和Pyle图谱而得出的骨龄结果进行比较。间隔4周后每个观察者再测定骨龄一次。 结果：通过分析肘部X线片的方法测定骨龄更为精确，因为采用该方法测定骨龄可以精确到半岁。根据观察者的评定，Sauvegrain法显示出很好的观察者之间的相关性（r=0．93）和可重复性（r=0．96）。Sauvegrain法与Greulich和Pyle图谱之间有很好的相关性（r=0．85）。然而，一些肘部生长中心显示出一种中间的发育形态，这种形态学不适合Sauvegrain法的评分。这就导致了数据分析时出现误差。我们建议对于这些样本设定中间评分，并且通过修改原始图表而使评分更为精确。 结论：改良的Sauvegrain法简单、可靠而且可重复性高，它补充了Greulich和Pyle图谱的不足。在临床实践中，骨骼成熟度可以通过骨龄、年生长率以及第二性征而得以很准确的评估。因此，当青春期需要进行骨骺或脊柱关节融合术时，这种方法对于确定手术时间具有重要意义。 可信水平：诊断性研究，Ⅱ级，进一步可信度参见作者介绍。     

Challenges in geriatric oral health research methodology concerning caregivers of cognitively impaired elderly adults

Little is known about oral health care behaviors of community-dwelling, cognitively impaired elderly (CIE) persons. Few studies have been conducted regarding the actual provision of oral care for CIE persons or the attitudes and concerns about oral health among their caregivers. The CIE person's ability to perform self-care decreases over time, and the role of the caregiver in daily oral care becomes increasingly important. The purpose of this pilot study was to explore the attitudes toward oral health and identify related concerns among caregivers who care for community-dwelling CIE persons. Caregivers were surveyed by means of a self-administered, mailed questionnaire. To maintain confidentiality, an intermediary was used for recruitment and data collection. Overall, 148 caregivers were invited by an intermediary to participate in the survey; only 21 (14%) consented to participate and returned the questionnaire. This paper discusses some of the numerous methodological challenges identified when an attempt was made to survey caregivers' attitudes toward and barriers to providing oral care for a dependent CIE.     

The Relationship Between Daily Life Stress and Gastrointestinal Symptoms in Women with Irritable Bowel Syndrome

Research on irritable bowel syndrome (IBS), a functional disorder of the gastrointestinal (GI) system, has linked GI symptoms to stress. This study examined the relationship between daily stress and GI symptoms across women and within woman in IBS patients (n = 26), IBS nonpatients (IBS-NP; n = 23), and controls (n = 26), controlling for menstrual cycle phase. Women (ages 20–45) completed daily health diaries for two cycles in which they monitored daily GI symptoms and stress levels. The Life Event Survey (LES) was used as a retrospective measure of self-reported stress. The across-women analyses showed higher mean GI symptoms and stress in the IBS and IBS-NP groups relative to controls but no group differences in LES scores. The within-woman analyses found a significant and positive relationship between daily stress and daily symptoms in both the IBS-NP and the IBS groups. Controlling for menstrual cycle had no substantial impact on the results.     

Atrioventricular Node Ablation for Optimization of Pacemaker Treatment in Hypertrophic Obstructive Cardiomyopathy

Dual chamber pacing is a new indication for the treatment of drug resistant hypertrophic obstructive cardiontyopathy (HOCM) in patients with normal atrioventricular (AV) conduction. In sinus rhythm, the efficacy of the treatment is mainly related to the ability to bypass the normal AV conduction system in order to obtain a complete and permanent right ventricular (RV) capture. This is achieved by programming short AV delays. On the other hand, patients with HOCM frequently have co-existing left ventricular diastolic dysfunction, and the atrial contribution to left ventricular filling is critical. The lack of improvement, rarely encountered, is probably due to incomplete RV capture andlor to the deleterious effect of short AV delay. Instrumental AV node prolongation may he indicated in this situation. This procedure should be undertaken when previous drug-induced AV prolongation has failed. In theory, AV node modulation (i.e., creating a I ± AV block) seems ideal. However, this technique remains difficult, with disappointing chronic results. Most authors hence perform "conventional" AV node ablation. Particular attention is taken in order to perform a proximal node ablation, resulting in a complete AV block with narrow QRS escape rhythm. The reported incidence of AV node prolongation ranges from 7.5%-37.5%. The efficacy of the procedure on symptoms is explained by improved left ventricular filling and/or a further reduction in the systolic gradient evoked by complete RV capture. Another indication for AV node ablation in HOCM is the occurrence of atrial fibrillation, in order to restore adequate and permanent RV capture .