Studies In Normal Adults Research Articles

Sonographic assessment of hyoid bone movement during swallowing: a study of normal adults with advancing age

Our aim in this study was to evaluate hyoid bone movement trajectories and the age-related changes during swallowing in healthy subjects by ultrasonography. Data were obtained from 30 healthy volunteers (15 men, 15 women) in three age groups (20-39, 40-59, 60-79 years). The subjects were examined while sitting in an upright position, with the back against a wall to control movement. The transducer was placed in a longitudinal scan above the larynx. The subjects were then given 5 mL of mineral water. The water bolus was held in their mouth until they were forced to do a rapid swallow. The imaging was repeated five times for averaging. The movement was divided into 4 phases: slowly ascending phase (A-B, Elevation); rapidly ascending phase (B-C, Anterior); temporary pause phase (position of maximum rise, Remain); and rapidly and slowly descending shifts toward the resting position phase (C-D, Return). We easily visualized the hyoid bone trajectory by using ultrasonography. In all cases, ultrasonographic analysis of the hyoid bone was confirmed to have a similar trajectory, as determined with videofluoroscopy. The average swallowing duration measurements increased with age. The measurement of the maximally elevated point of the hyoid bone decreased with age. The movement of the hyoid bone during swallowing can be visualized by US. The trajectory of the hyoid bone in sagittal section indicated the capability of swallowing, and may detect some anomalies in swallowing.

Identifying Advanced Glycation End Products as a Major Source of Oxidants in Aging: Implications for the Management and/or Prevention of Reduced Renal Function in Elderly Persons

Aging is characterized by increasing inflammation and oxidant stress (OS). Reduced renal function was present in more than 20% of normal-aged individuals sampled in the National Health and Nutrition Examination Survey (NHANES) cross-sectional study of the US population. Longitudinal studies in the United States and Italy showed that renal function does not decline in some individuals, suggesting that a search for causes of the loss of renal function in some persons might be indicated and interventions to reduce this outcome should be sought. Because advanced glycation end products (AGEs) induce both inflammation and OS, accumulate with age, and primarily are excreted by the kidney, one outcome of reduced renal function in aging could be decreased AGE disposal. The build-up of AGEs with reduced renal function could contribute to inflammation, increased oxidant stress, and accumulation of AGEs in aging. In fact, results from a longitudinal study of normal aging adults in Italy showed that the most significant correlation with mortality was the level of renal function. A clear link between inflammation, OS, AGEs, and chronic disease was shown in studies of mice that showed that reduction of AGE levels by drugs or decreased intake of AGEs reduces chronic kidney disease (CKD) and cardiovascular disease of aging. The data support a role for AGEs in the development of renal lesions in aging mice and reveal that AGEs in the diet are very important contributors to renal and cardiovascular lesions. AGEs signal through two receptors, one of which is anti-inflammatory (AGER1) and the other is proinflammatory (RAGE). Overexpression of AGER1 protects against OS and acute vascular injury. The reduction of AGEs in the diet is as efficient in preventing aging-related cardiovascular and renal lesions in mice as that seen with calorie restriction. Studies in normal adults of all ages and those with CKD suggest that the findings in mice may be directly applicable to both aging and CKD. Namely, the dietary content of AGEs determines the serum levels of AGEs and inflammatory mediators and urine AGE levels in both normal subjects and CKD patients. Importantly, reduction of AGEs controls these changes in both normal subjects and CKD patients, and the phenotypic changes in AGER1 are reduced in CKD patients by decreasing the amount of AGEs consumed with the diet. These data suggest that the changes in renal function in normal aging may be subject to control and this subject deserves renewed attention.

Serum 1,5-anhydroglucitol (Glycomark?) levels in children with and without type 1 diabetes mellitus

Postprandial hyperglycemia associated with diabetes is a risk factor for cardiovascular disease. Currently, glycated hemoglobin A(1c) (HgbA(1c)) and glycated protein fructosamine are not sensitive markers for acute and short-term hyperglycemia. 1,5-Anhydroglucitol (1,5-AG) (Glycomark; Tomen America, New York, NY, USA) is reported in adults with type 1 diabetes mellitus (T1DM) and type 2 diabetes mellitus (T2DM) as a marker for postmeal hyperglycemia. However, the reference ranges for 1,5-AG in normal children and children with T1DM are not known. We studied 1,5-AG levels in 10 control children (6 males and 4 females) and 10 children with T1DM (7 males and 3 females). The levels of 1,5-AG in the normal controls were higher than those in children with T1DM (24.60 +/- 3.99 microg/mL vs. 4.75 +/- 2.95 microg/mL; p < 0.0001). There were no gender differences noted. The 1,5-AG levels were negatively correlated with HgbA(1c) (r =-0.9366; p < 0.0001) and the peak postmeal plasma glucose concentrations (Pearson r =-7230; p = 0.0003). Our findings suggest that despite good glycemic control, postprandial glucose concentrations are elevated and that 1,5-AG showed a difference between controls and children with T1DM. The data are comparable with previous studies in normal adults and in those with T1DM and T2DM. They support the use of 1,5-AG concentrations, together with HgbA(1c), to evaluate therapy, especially to target postprandial hyperglycemia.

Electrophysiology in the study of developmental language impairments: Prospects and challenges for a top-down approach

There is a good deal of interest in the application of neurocognitive techniques to investigate the underpinnings of developmental language impairments (DLIs). Electrophysiological techniques such as electroencephalography and magnetoencephalography offer the promise of the ability to track brain activity with precision in time and space. This article describes a number of findings from studies of normal adults and children that are relevant to neurocognitive studies of developmental language impairments and outlines a series of challenges that should be met in order for electrophysiological measures to realize their promise.

Comparative Study of Power-Based Versus Mean Frequency-Based Transcranial Color-Coded Duplex Sonography in Normal Adults

Power-based transcranial color-coded duplex sonography (p-TCCD) is a new ultrasonic method that has advantages compared with frequency-based TCCD (f-TCCD), since it is essentially independent of the angle of insonation, not subject to aliasing, and has a better signal-to-noise ratio. The purpose of this study was to evaluate the ability of p-TCCD to visualize flow in cerebral parenchyma and to compare the advantages, limitations, and reliability of velocity measurements of p-TCCD versus f-TCCD in the major basal cerebral arteries of normal subjects. Two investigators performed 15 p-TCCD and 15 f-TCCD studies in 30 normal subjects with adequate ultrasonic windows. Each investigator did a p-TCCD or f-TCCD study in every patient, and each was blinded in every case to the results of the other. Peak systolic (Vs) and end-diastolic (Vd) velocities were determined in the anterior, middle, and posterior cerebral, basilar, and vertebral arteries. The reliability of p-TCCD velocimetry was evaluated by calculating both the correlation coefficient (r) of the difference between p-TCCD versus f-TCCD measurements and the coefficient of variation (CV), defined as the difference between the mean values for p-TCCD and f-TCCD divided by the mean values for f-TCCD measurements, expressed as percent. p-TCCD did not display flow in cerebral parenchyma but depicted arteries with a course perpendicular to that of the ultrasound beam and showed good reliability of velocity measurements in all examined arteries: for Vs, r was .84 to .93 (P < .001) and CV was 7.7% to 10.8%; for Vd, r was .87 to .90 (P < .001) and CV was 10.3% to 13.7%. The lack of directional and velocity information and tissue motion artifacts were unimportant limitations in p-TCCD. Compared with f-TCCD, p-TCCD had no important advantages but had several unimportant limitations in a study of normal adults with adequate ultrasonic windows.

Is interhemispheric transfer time related to age? A developmental study

In simple visuomotor reaction time tasks, the difference between reaction time (RT) in the uncrossed hand/hemifield condition from RT in the crossed hand/hemifield, known as CUD (crossed-uncrossed difference), has been interpreted as reflecting interhemispheric transmission time (IHTT). Several studies in normal adults have found a CUD of a few milliseconds (3–4), while an abnormally long CUD has been reported in patients who underwent a surgical section of the corpus callosum or in congential acallosal subjects. The corpus callosum, which is the most important structure for interhemispheric transfer of information, completes its myelination approximately by age ten. It has been hypothesized that the functional maturity of the corpus callosum concides with the termination of the myelination cycle. No developmental study has focused on the development of IHTT, in relation to callosal maturation. The purpose of our study has been to investigate the development of interhemispheric transfer of visuomotor information in children aged seven to eleven, using a simple RT task with lateralized visual stimuli. The results indicate an age-related decrease of CUD, which we interpret as reflecting the maturation of the corpus callosum during childhood years.

Surgically induced immunologic alterations in the child

Surgery is generally believed to be an immunodepressant. This assumption is based, in part, upon studies of compromised patients undergoing major operation. Similar studies in normal adults following elective procedures are contradictory and little information is available regarding the pediatric surgical patient. This paper presents a study of immune function in children undergoing elective operation. Fifty healthy preoperative children (mean age: 20 months) were randomly selected. Ninety-five percent underwent inguinal herniorrhaphy. Operative time averaged 45 minutes (range: 30 to 90 minutes). Anesthesia consisted of Halothane and Nitrous Oxide in all cases. Approximately 2.5 cc of heparinized blood and 0.5 cc of serum were obtained immediately prior to and 2 hours following operation. Half of the children underwent assays of neutrophil function including absolute count, random migration, chemotaxis, phagocytosis, and bacterial killing. Serum was examined for opsonization of Staphylococcus aureus using the chemiluminescence method. The remaining children underwent lymphocytic quantitation including absolute count, total T cells, total B cells, T-helper cells, T-suppressor cells, and T-helper/suppressor ratio. Absolute neutrophil count increased 2.4 times preoperative values (P less than 0.01). There were, however, no significant alterations in neutrophil functional capabilities. Similarly, there was no alteration in serum opsonic capacity. There was a significant decrease in absolute lymphocyte count (6560-4013, P less than 0.01) postoperatively, and T cells, T-helper, T-suppressor, and B cells were all significantly affected (P less than 0.01 to 0.02). There was no change in the T-helper/suppressor ratio.(ABSTRACT TRUNCATED AT 250 WORDS)

A model for determination of total body protein synthesis based upon compartmental analysis of the plasma [ 15N] glycine decay curve

A model for whole body glycine nitrogen flux based on the compartmental analysis of plasma [ 15N] glycine decay curves is described and used for the measurements of (1) total body glycine nitrogen flux and the components of this flux in three healthy young adults and (2) total body protein synthesis based on the conversion of 15N to excretory products, ie, the sum of urinary [ 15N] urea and 15NH 3 and the amount of labeled urea remaining in the body at five hours following administration of [ 15N] glycine. The mean glycine nitrogen flux was 3.93 ± 0.42 mg N · kg −1 · h −1 (SEM). The major components of this flux are de novo synthesis of glycine, which accounts for 18% to 27%, and release from protein breakdown, which accounts for 62% to 73%. The outward pathways of glycine from the total body free glycine pool are conversion to other amino acids and oxidation to excretory end products (30% to 42%) and incorporation into protein, which accounts for 45% to 61% of glycine N loss from the metabolic pool. The mean rate of total body protein synthesis as determined by compartmental analysis was 3.56 g protein · kg −1 · day −1. The results that were obtained for protein synthesis and whole body glycine kinetics accord well with previous studies in normal adults, using the stochastic model.

Event-related potential studies of cerebral specialization during reading: I. Studies of normal adults

A number of methodological features were incorporated in a paradigm designed to maximize the likelihood of finding reliable event-related potential (ERP) signs of functional specializations between and within the cerebral hemispheres. Every subject was more accurate in identifying words presented to the right than to the left visual field. The morphology of the ERPs elicited by these words varied considerably as a function of electrode position both within and between the hemispheres. Amplitude asymmetries of ERP components recorded from occipital regions of the two hemispheres varied systematically with the position of the word in the visual field. On the other hand, ERPs from more anterior (temporal and frontal) regions displayed large asymmetries which were in the same direction regardless of the visual field of word presentation. The most prominent such asymmetry was in the negativity in the region 300–500 msec (N410) which was larger in the left than the right hemisphere in every subject. These results demonstrate that in this paradigm which demands specialized language processing ERPs are sensitive to aspects of cerebral organization both within and between the two hemispheres.

Distribution of IgG subclasses in human B lymphocytes: evidence for dual expression of subclasses in surface and cytoplasmic IgG in minor B lymphocyte subpopulations.

The distribution of B lymphocytes expressing surface IgG subclasses has been defined by using immunochemically purified, subclass-specific, F(ab')2 fragments. Studies in normal adults showed 1.16% of peripheral lymphocytes to be positive for IgG. Percentages of IgG subclasses were IgG2, 0.50%; IgG4, 0.40%; IgG1, 0.33%; and IgG3, 0.14%. Dual label experiments indicated that minor subpopulations of normal lymphocytes may express more than one IgG subclass, both on surface IgG as well as in the cytoplasm. Cord blood showed significantly less IgG4-positive cells than were present in adults. Preliminary studies of patients with common variable immunodeficiency showed shifts in cell populations paralleling those previously noted in serum. Some patients with multiple myeloma were noted to exhibit striking shifts in the distribution of B lymphocytes toward a population of cells showing a similar IgG subclass to that of the M-component.

Aging and Intelligence in Young Retarded Adults: A Cross-Sectional Study of Fluid Abilities in Three Samples

The effects of aging on fluid mental abilities of 90 mentally retarded adults from three settings were investigated in a cross-sectional study. To test the hypothesis that the early adult retarded show the same decline in fluid abilities as the non-retarded, the Raven Progressive Matrices, Porteus Mazes and a paired-associate memory test were administered to subjects ranging in age from 19 to 43 yr., all of whom had received WAIS IQs in the mildly retarded range when in their late teens. Scores on the three tests correlated negatively with the teenage WAIS Verbal IQ but positively with the teenage Performance IQ. Contrary to studies of normal adults, the older retarded subjects did somewhat better than the younger ones. Significant differences between age groups emerged only on the paired-associate scores. The results raise the possibility that fluid mental abilities show a later decline in the mildly retarded than in the non-retarded.

Real-time imaging with a new ultrasonic camera: part II, preliminary studies in normal adults.

A new transmission ultrasound camera system has provided focused images in real time through the abdomen of adult volunteers at average incident sound intensity levels of less than 1 mW/cm-2. The camera uses a unique acousto-mechanical lens/deflection system and a linear array of piezoelectric transducers to detect the ultrasound image. BONY STRUCTURES AND COSTAL CARTILAGES WERE CLEARLY SEEN. The colon was regularly seen and the kidney could be outlined in several subjects. The stomach and duodenal bulb were demonstrated and peristalsis was observed using a barium contrast material. The camera has the potential of extending the use of ultrasound in clinical medicine by providing an ultrasound soft tissue imaging system analogous to an x-ray fluoroscope. The need for further clinical evaluation and research to improve the images is emphasized.

Ego Functions in the Middle and Later Years: A Thematic Apperception Study of Normal Adults

Ego Functions in the Middle and Later Years: A Thematic Apperception Study of Normal Adults

Studies in normal adults for variation in zinc turbidity test with sex and age.

Studies in normal adults for variation in zinc turbidity test with sex and age.