Actual Chronological Age Research Articles

Predictive equations and energy expenditure: Is a guess good enough?

DITURE: IS A GUESS GOOD ENOUGH? Suzie Ferrie Critical Care Dietitian, Royal Prince Alfred Hospital. Lacking access to indirect calorimetry, many clinicians need to be able to predict a patient’s energy requirements; equations are available that provide a quick and non-invasive way to do so, and these can be a valuable addition to the clinician’s tool box. However, as with any tool, the results will be poor if the user fails to understand how the tool works, or lacks skill in using it properly. The equations do have limitations! Predictive equations cannot transform incorrect or inaccurate data into a useful result, they cannot replace other essential components of patient assessment (such as physical examination), and they are no substitute for ongoing close monitoring of the nutrition support patient. Understanding the origins of the predictive equations can help in using them more appropriately. The number and type of subjects used in developing the equations may indicate the most appropriate population in which they can be used, and suggests some weaknesses of the equations. For example, the Harris-Benedict equations were developed from a group of young (average age 29) and lean (average BMI 21) Americans at the beginning of the 20 century when lifestyle and diet were very different from ours (1). The Schofield equations used more than 7000 people from 23 different countries, with a wide range of ages and weights but with a preponderance of men; a significant number (more than 10% of the total) were very fit military personnel (2,3). The Mifflin-StJeor equations were based on a group of contemporary Americans (50% were obese!) (4) The Ireton-Jones equations, notably, were developed using sick hospital patients, but may be quite rigid in their application to some diagnostic groups (5). It is important to note the assumptions underlying each equation, and the reasons for their format (the existence of different equations for men and women, for example, or separating by age group). It may be appropriate to use an age value other than the patient’s actual chronological age, or to use an adjusted weight value in the equation. The use of adjustment factors (such as ‘stress’ or ‘activity’ factors) (6,7) may allow a hospital patient’s needs to be predicted from an equation developed in healthy people – but there are many pitfalls here, and an enormous potential for increasing the errors inherent in this method. There are other considerations too: to avoid overfeeding, it is important to ensure that the predicted requirement is viewed as the patient’s total needs (rather than distinguishing between protein and non-protein energy). Additionally, expressing the result as a range (rather than a fixed value) makes it clear that it is an estimate and avoids implying an unrealistic level of accuracy, which can undermine the credibility of the clinician. References

Incremental lines in root cementum of human teeth: An approach to their role in age estimation using polarizing microscopy

Age estimation is an important factor in the identification of an individual in forensic science. The hard tissues of the human dentition are able to resist decay and degradation long after other tissues are lost. This resistance has made teeth useful indicators for age calculation. Recent research indicates that tooth cementum annulations (TCA) may be used more reliably than any other morphological or histological traits of the adult skeleton for age estimation. The purpose of this study was to examine the correlation between age and the number of incremental lines in human dental cementum and to ascertain the best method of studying cementum with respect to different forms of microscopy. Thirty nonrestorable teeth were extracted from 20 people, and longitudinal ground section of each tooth was prepared. Photomicrographs of the area at the junction of apical and middle third of the root under light and polarized microscope were taken. The cementum was composed of multiple light and dark bands that were counted on the photomicrograph with the help of image analysis software and added to the average eruption time of individual tooth. The predicted age of the individual was thus obtained. Results showed a significant correlation between the predicted age and actual chronological age of the individual. These data indicate that quantitation of cementum annuli is a moderately reliable means for age estimation in humans and polarizing microscopy is a better means of visualizing incremental lines of cementum compared to light microscopy.

Acquired amnesia in childhood: A single case study

We report the case of C.L., an 8-year-old child who, following the surgical removal of an ependymoma from the left cerebral ventricle at the age of 4 years, developed significant difficulties in retaining day-to-day events and information. A thorough neuropsychological analysis documented in C.L. a severe anterograde amnesic syndrome, characterised by normal short-term memory, but poor performance on episodic long-term memory tests. In particular, C.L. demonstrated virtually no ability to recollect new verbal information several minutes after the presentation. As for semantic memory, C.L. demonstrated general semantic competencies, which, depending on the test, ranged from the level of a 6-year-old girl to a level corresponding to her actual chronological age. Finding a patient who, despite being severely impaired in the ability to recollect new episodic memories, still demonstrates at least partially preserved abilities to acquire new semantic knowledge suggests that neural circuits implicated in the memorisation of autobiographical events and factual information do not overlap completely. This case is examined in the light of growing literature concerned with the dissociation between episodic and semantic memory in childhood amnesia.

Accuracy of Two Simple Methods for the Assessment of Health-Related Physical Fitness

We have developed a useful equation for estimating health-related physical fitness age. This version of health-related fitness age was developed as an extension of the biological age index and is useful for evaluation of individual differences in functional abilities of middle-aged and older adults. This measure consists of 4 independent variables fitness (VO2 max, standing trunk flexibility, %fat, and grip strength). However, direct measurement of maximal oxygen uptake (VO2 max) is an invasive clinical procedure and not practical for large scale work. In the current study, we attempted to assess the fitness age more feasibly. We selected a questionnaire method and a 12-min. submaximal treadmill walk test as substitutes for the VO2 max test. The three fitness ages were computed for 23 Japanese men (M(age) 54.7 +/- 10.7 yr.), using actual VO2 max (actual fitness age), questionnaire VO2 max (predicted questionnaire fitness age), and treadmill VO2 max (predicted treadmill fitness age). Predicted questionnaire fitness age (61.0 +/- 10.5 yr.) and predicted treadmill fitness age (60.0 +/- 12.4 yr.) were significantly correlated with actual fitness age (60.1 +/- 12.4 yr.) (r= .96 and .97, respectively). There were no significant differences among the three indices, but there was a significant difference between actual fitness age and chronological age (p<.05). For VO+/-2 max substituting the questionnaire for the treadmill estimate is acceptable in assessing fitness age and reducing the clinical risk for middle-aged and older Japanese men.

DNA repair and mutagenesis in Werner syndrome.

Werner syndrome (WS) is the hallmark premature aging syndrome in which the patients appear much older than their actual chronological age. The disorder is associated with significantly increased genome instability and with transcriptional deficiencies. There has been some uncertainty about whether WS cells are defective in DNA repair. We thus examined repair in vitro in nuclear and mitochondrial DNA. Whereas cellular studies so far do not show significant DNA repair deficiencies, biochemical studies with the Werner protein clearly indicate that it plays a role in DNA repair.

Efficacy of free flaps for pediatric trauma patients in an adult trauma center.

Although many trauma centers are primarily "adult-oriented," the presentation of unusual life- or limb-threatening wounds in children occasionally have mandated urgent microvascular tissue transfer for salvage. For these rare instances, should a microsurgical team accustomed to dealing with adult trauma patients even attempt to meet such a specialized challenge? A retrospective analysis of all free flaps performed by the author's team in trauma patients from 1984 to 1993, revealed only 10 pediatric patients who had had 11 separate free flaps. Their ultimate success rate was 90.9 percent--statistically the same rate (87.0 percent) as for 93 adult free flaps. The majority of these pediatric flaps were for urgent coverage of the lower extremity and they were all successful, eliminating any need for traditional pedicled flaps during the same time period. Improvement in technical expertise and judgment seemed to be more important factors than actual chronological age in determining free-flap success in general, and in children in particular. Therefore, free flaps in the pediatric population can be appropriately performed in an adult trauma center.

Accuracy of age estimation from developing teeth of a population of known age (0–5.4 years)

AbstractThe accuracy of several methods of age estimation based on developing teeth was tested on 63 individuals of known age between 0 and 5.4 years from the Spitalfields Collection. The following methods of age estimation were tested: atlas method of Schour and Massler; diagram of Gustafson and Koch; mineralization age of some deciduous and permanent teeth, Moorrees, Fanning and Hunt, a modified method of Moorrees et al. by Smith, and quantitative methods using deciduous tooth length and weight regression equations, Deutsch, Tam and Stack. Accuracy was measured as the difference between dental age from the developing teeth and actual chronological age available from parish records.Results show that the atlas and diagram methods are considerably more accurate for this population and age group than methods based on mineralization stages of formation. Accuracy for the atlas method was 0.11 (± 0.30) year and diagram method 0.10 (± 0.37) year. The accuracy for methods based on mineralization stages of formation were considerably less accurate: 0.52 (± 0.62) year for deciduous teeth, 0.57 (± 0.42) year for permanent teeth and 0.29 (± 0.39) year for the same method but modified specifically for prediction. Significant differences (P&lt;0.01) between dental and chronological age were apparent for methods based on mineralization stages.Accuracy of the quantitative methods during the first year of postnatal growth was high, the most accurate being deciduous molar length at 0.02 (± 0.15) year.Factors influencing accuracy and the problems encountered with the methods tested are discussed. The Schour and Massler atlas remains the recommended method of dental age estimation for this age group for reasons of accuracy and ease.

Diagnosis of GH deficiency: Auxologic and GH response criteria

Health providers examining children of short stature should assess adequacy of growth determine growth rate and predict final height with treatment. They can use established standards of growth to compare the childs height with that of other children of the same age to assess growth normalcy. If the childs height is lower than the 3rd/5th percentiles the health provider must also determine whether the growth velocity is 3 cm/year by following the child for 6 months to 1 year and whether retardation of skeletal maturity is of more than 2 bone age years to confirm abnormal growth. while the child is being followed for growth velocity the health provider should prescribe a balanced nutritious diet. If these conditions are met and the child exhibits facial characteristics of growth hormone (GH) deficiency central obesity unusually small lower jaw and prepuberal sex characteristics and behavior after usual age of puberty the health provider can diagnose GH deficiency. 17% of children of short stature in a certain area of India have GH deficiency. The actual height chronological age and bone age are needed to predict the final adult height to monitor the impact of GH therapy. GH levels of less than 7 ng/ml in children not suffering from protein malnutrition suggest total GH deficiency. GH measurements must be done over 24 hours since GH secretion is pulsatile. Sleep exercise and intravenous infusion of 0.5 g/kg body weight of arginine stimulates GH secretion. The most common pharmacologic tests to determine GH secretory status include insulin hypoglycemia and clonidine. Clonidine induces fewer side effects and is more safe than insulin hypoglycemia. Since a child can secrete normal amounts of GH with insulin hypoglycemia the health provider should conduct 1 physiologic (sleep/exercise) test and 1-2 pharmacologic tests to diagnose GH deficiency.

Cross-validation of Shotwell's revision of the Kuhlmann-Binet scale with severely retarded patients.

A large segment of hospitalized retardates are rated in the severe or profound ranges of mental retardation as expressed by measured intelligence. The lower limits of such instruments as the Revised Stanford-Binet Scale or the Wechsler Intelligence Scale for Children are too high for use with this population. Therefore, psychologists often operationally ignore the actual chronological age and employ scales for this assessment, such as the KuhlrnannBinet Scale (3), the Cattell Infant Scale ( I), and the Vineland Social Maturity Scale (2). Shotwell (4) attempted to improve the Kuhlmann-Binet by eliminating 4 items and rearranging the remaining 21 in order of their difficulty. She recommended that chis revision be cross-validated with other measures of infant ability and social development. This study examined the relationships among the Kuhlmann-Binet Scale (KBS), the Shotwell Revision of the Kuhlrnann-Binet Scale (S-KBS), the Cattell Infant Scale (CIS), and the Vineland Social Maturity Scale (VSMS). It was assumed that, if the S-KBS is a more sensitive instrument than the KBS, it should correlate significantly higher with the CIS and VSMS in our sample of 92 male and 38 female patients (MAS < 2 yr.; MCA = 11 yr.). The KB, S-KBS, CIS, and the VSMS were administered in randomized order. Pearson product-moment correlations ranging from .72 to .98 were found between the MAS and IQ scores on all 4 psychometric instruments. While crossvalidating Shotwell's Revision of the Kuhlmann-Binet, these rs indicate rhat her revision differs little from the KBS. Regression equations were calculated between pairs of tests. A test of linearity indicated no significant deviation. It appears that no one of these instruments varies significantly from the - others in measuring the intelligence of severely mentally retarded patients. The implication is that where appropriate, the VSMS or the KBS and S-KBS can be used in place of the longer and more complicated CIS with the same results in terms of reliability. Further research is necessary to assess the validity of these tests in predicting the behavioral skills appropriate to this degree of retardation.