Texture Evolution during Isothermal, Isostrain and Isobaric Loading of Polycrystalline Shape Memory NiTi.

In situ neutron diffraction was used to provide insight into martensite variant microstructures during isothermal, isobaric, and isostrain loading in shape memory NiTi. Results show variant microstructures were equivalent for the corresponding strain and more importantly, the reversibility and equivalency was immediately evident in variant microstructures that were first formed isobarically but then reoriented to a near random self-accommodated microstructure following isothermal deformation. Variant microstructures formed isothermally were not significantly affected by a subsequent thermal cycle under constant strain. In all loading cases considered, the resulting variant microstructure correlated with strain and did not correlate with stress. Based on the ability to select a variant microstructure for a given strain despite thermomechanical loading history, the results demonstrated here can be obtained by following any sequence of thermomechanical loading paths over multiple cycles. Thus for training shape memory alloys (repeating thermomechanical cycling to obtain the desired variant microstructure), optimal paths can be selected so as to minimize the number of training cycles required thereby increasing the overall stability and fatigue life of these alloys in actuator or medical applications.

Gross Motor Function Classification System and outcome tools for assessing ambulatory cerebral palsy: a multicenter study.

The relationships between different levels of severity of ambulatory cerebral palsy, defined by the Gross Motor Function Classification System (GMFCS), and several pediatric outcome instruments were examined. Data from the Gross Motor Function Measure (GMFM), Pediatric Orthopaedic Data Collection Instrument (PODCI), temporal-spatial gait parameters, and oxygen cost were collected from six sites. The sample size for each assessment tool ranged from 226 to 1047 participants. There were significant differences among GMFCS levels I, II, and III for many of the outcome tools assessed in this study. Strong correlations were seen between GMFCS level and each of the GMFM sections D and E scores, the PODCI measures of Transfer and Mobility, and Sports and Physical Function, Gait Velocity, and Oxygen Cost. Correlations among tools demonstrated that the GMFM sections D and E scores correlated with the largest number of other tools. Logistic regression showed GMFM section E score to be a significant predictor of GMFCS level. GMFM section E score can be used to predict GMFCS level relatively accurately (76.6%). Study data indicate that the assessed outcome tools can distinguish between children with different GMFCS levels. This study establishes justification for using the GMFCS as a classification system in clinical studies.

Distribution of the cellular uptake of phosphorothioate oligodeoxynucleotides in the rat kidney in vivo.

Previous animal studies have demonstrated that following systemic administration phosphorothioate oligodeoxynucleotides (S-ODNs) are primarily excreted by the kidneys and that renal tissue levels of S-ODNs exceed that of other organs. Thus, the kidney may be an ideal target organ for application of antisense S-ODNs in vivo. We examined which cells within the rat kidney have uptake of radiolabeled S-ODNs following intravenous infusion. A 20-base 35S-ODN was infused into 6 adult male Wistar rats. Three animals each were sacrificed 30 min and 4 h after infusion. The kidneys were then removed, fixed, and tissue autoradiography was performed. Similar results were obtained in both groups. The highest level of radioactivity was seen within the proximal tubules. Lower levels of activity were seen within the glomerulus, the parietal epithelial cells of Bowman's space, and distal tubular cells. Very weak activity was also detected within the cells of the loop of Henle and the medullary collecting ducts. These results demonstrated that within the kidney S-ODNs were taken up primarily by proximal tubular cells, with much lower uptake by cells in other segments of the nephron.

Standing balance training: effect on balance and locomotion in hemiparetic adults.

The effects of balance retraining on standing balance and locomotor performance were examined in postacute hemiparetic adults. Balance during habitual and instructed-even standing, as well as locomotor performance, were measured before and after a three- to four-week treatment period. Two groups of 21 matched subjects participated in physical therapy. One group received standing balance training with a specially designed feedback device that provided dynamic visual information about relative weight distribution over the paretic and nonparetic limb. Subjects trained with the feedback device showed significantly better static standing symmetry than did subjects who did not receive augmented feedback, p less than .05. Although both groups improved significantly in gait velocity, cadence, stride length, and cycle time, p less than .01, the initially identified asymmetrical locomotor pattern appeared to be only minimally affected by the standing balance training. Results indicated that although standing balance and locomotor control mechanisms may be highly interrelated, a reduction in standing balance asymmetry does not necessarily lead to a concomitant reduction in the asymmetrical limb movement patterns associated with hemiparetic locomotion.

c-myc expression in the thyroid. I: Normal, adenomatous, and cancerous thyroid tissue.

Recent investigations have suggested that myc oncogene expression may be important in the development or progression of thyroid tumors. The purposes of the present study were to assess cellular (c)-myc expression in thyroid adenomas (n = 5), as well as in thyroid cancer (n = 4) and in normal thyrocytes (n = 7). Total RNA was prepared by extraction with guanididium thiocyanate and ultracentrifugation through a CsCl2 cushion. 30 micrograms total RNA was size fractionated on a 1% (w/v) agarose/formaldehyde gel and transferred to nylon membranes. These membranes were hybridized to a 32P-labelled third exon c-myc DNA. Following hybridization, blots were washed under high stringency and subjected to autoradiography; radioautographic bands were assessed visually or were quantitated by scanning densitometry. Nodular tissue had approximately the same degree of expression of the 2.4 Kb c-myc message as the surrounding normal tissue from the same gland (0.66 +/- 0.09 vs. 1.0 +/- 0.26, respectively); normal thyrocytes were capable in every instance of expressing the 2.4 Kb c-myc message. Thyroid cancer tissue expressed this message (0.91 +/- 0.17) but only at a level comparable to normal tissue. No other bands of hybridization were detected in any samples. We conclude that c-myc oncogene expression is comparable in normal thyrocytes and in thyroid nodules or thyroid cancer samples. These findings support a role for c-myc in both normal and neoplastic thyrocyte growth.

c-myc expression in the thyroid. II: Thyrocytes and peripheral and intrathyroidal lymphocytes from patients with autoimmune thyroid disease.

Enhanced oncogene expression observed in lymphocytes from patients with systemic lupus erythematosus has suggested the importance of studying oncogene expression and regulation in the cellular events of autoimmune thyroid diseases (AITD). The present study examines oncogene expression in peripheral and intrathyroidal lymphocytes from patients with Hashimoto's disease (HD) and Graves' disease (GD). Intrathyroidal lymphocytes from a patient with primary thyroid lymphoma were also examined. Lymphocytes were isolated by Ficoll-Hypaque gradients, and total RNA was prepared by extraction with guanididium thiocyanate and ultracentrifugation through a cesium chloride cushion. RNA concentrations were determined by O.D. readings at 260/280 nm and each sample subjected to gel electrophoresis with ethidium bromide staining to assure the integrity of the RNA. 30 micrograms total RNA was size fractionated on a 1% (w/v) agarose/formaldehyde gel and transferred to nylon membranes. These membranes were hybridized with nick-translated 32P labelled c-myc DNA (exon III), washed at high stringency and subjected to autoradiography. Specific bands were quantitated by scanning densitometry. Five RNA samples from GD thyroids had 2.4 Kb bands corresponding to c-myc with a mean O.D. (+/- SD) of 0.76 +/- 0.23, whereas 7 from normal thyroid glands had mean O.D. of 1.0 +/- 0.26. Peripheral lymphocytes from 7 GD patients had a mean O.D. of 1.41 +/- 0.25, 4 HD patients had a mean O.D. of 1.05 +/- 0.10 and 2 normal patients had a mean O.D. of 1.4 +/- 0.14. The readings for a sample obtained from intrathyroidal lymphocytes of a patient with HD and thyroid lymphoma were 1.0 and 1.4, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Widespread distribution of a 7S RNA in archaebacteria.

An RNA of nonribosomal origin was found in the extreme halophilic bacteria. This novel small RNA was found to be a homogeneous species by RNA fingerprinting. Analysis of the ribonuclease T1 oligonucleotides gave no evidence of the presence of posttranscriptional modifications. Comparisons of electrophoretic mobility with other RNAs of known size suggest that this is a 7S RNA containing 325-375 nucleotides. An RNA of similar mobility was found in all major divisions of the archaebacteria. Insufficient sequence information is available to determine whether these RNAs are homologs of any other known small RNA.

Watching the reimbursement dollars: program validation aims to control waste.

In just one state, HCFA staff conducting program validation reviews found inappropriate Medicare and Medicaid expenditures of $1.8 million, stemming from improper billing practices by suppliers of durable medical equipment and faulty treatment of claims and cost reports.