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Biomedical subjects

M C Thompson

Publications and source records attributed to M C Thompson.

At least 19 recordsLinked to original sources

Effects of ion motion in intense beam-driven plasma wakefield accelerators.

Recent proposals for using plasma wakefield accelerators (PWFA) as a component of a linear collider have included intense electron beams with densities many times in excess of the plasma density. The beam's electric fields expel the plasma electrons from the beam path to many beam radii in this regime. We analyze here the motion of plasma ions under the beam fields, and find for a proposed PWFA collider scenario that the ions completely collapse inside of the beam. Simulations of ion collapse are presented. Implications of ion motion on the feasibility of the PWFA-based colliders are discussed.

Journal Article↗

Single-use plaque removal efficacy of three power toothbrushes.

OBJECTIVES: To compare the safety and plaque removal efficacy of two oscillating/rotating/pulsating toothbrushes (Oral-B ProfessionalCare 7000 [PC 7000] and Oral-B 3D Excel [3DE]) and a high-frequency toothbrush (Sonicare Advance, Philips Oral Healthcare; SA) in a single-use, examiner-blind, three period crossover study. METHODS: After refraining from all oral hygiene procedures for 23-25 hours, subjects received an oral tissue examination and those with pre-brushing whole mouth mean plaque scores > or = 0.6 based on the Rustogi et al. Modified Navy Plaque Index were randomly assigned to treatment sequence. After brushing with the assigned toothbrush and a commercially available dentifrice for 2 minutes, oral tissues were then re-examined and post-brushing plaque scores recorded. Following a brief washout period between two additional visits, the above procedures were repeated with the two alternate toothbrushes. One examiner, blinded to the treatment sequence, performed all clinical measurements. RESULTS: A total of 79 subjects (28 males and 51 females) were enrolled and completed the study. Each toothbrush was found to be safe and significantly reduced plaque levels after a single brushing. The PC 7000 and 3DE were equally more effective in plaque removal than the SA, at all tooth areas, reducing plaque by 59.0%, 59.7% and 51.8%, respectively on whole mouth surfaces, and by 67.5%, 67.8% and 59.4%, respectively on approximal surfaces. CONCLUSIONS: The action of the oscillating/rotating/pulsating toothbrushes (Oral-B ProfessionalCare 7000 and Oral-B 3D Excel) was more effective in plaque removal than the high-frequency toothbrush (Sonicare Advance).

Adolescent↗

Plaque removal efficacy of two electric toothbrushes with different brush head designs.

OBJECTIVES: To compare the safety and plaque removal efficacy of two electric toothbrushes, one a rechargeable oscillating/pulsating toothbrush with a small round brush head (Oral-B ProfessionalCare 7000; PC 7000), the other a battery-operated toothbrush with a dual moving brush head (Crest SpinBrush Pro; SBP). METHODS: The study had a randomised, examiner-blind, two-arm crossover design. All subjects received an oral prophylaxis and used both toothbrushes on alternating days for a two-week practice period. After abstaining from all oral hygiene procedures for 23-25 hours, subjects received an oral tissue examination and those with pre-brushing whole mouth mean plaque scores > or = 0.60 measured by the Rustogi et al. Modified Navy Plaque Index were randomly assigned to treatment sequence. Subjects brushed with their assigned toothbrush for 2 minutes using a commercially available dentifrice. Oral tissues were then re-examined and post-brushing plaque scores recorded. After a brief washout period, the above procedures were repeated with the alternate toothbrush. One examiner, blinded to the treatment sequence, performed all clinical measurements. RESULTS: A total of 70 subjects (24 males and 46 females) were enrolled and completed the study. Each toothbrush was found to be safe and significantly reduced plaque levels after a single brushing. The PC 7000 was significantly more effective in plaque removal than the SBP at all tooth areas, reducing whole mouth plaque by 61% versus 58% and plaque from approximal surfaces by 69% versus 65%, respectively. CONCLUSIONS: The action of the oscillating/pulsating toothbrush with a small round brush head, Oral-B ProfessionalCare 7000, is more effective in plaque removal than the battery-operated Crest SpinBrush Pro toothbrush with a larger dual moving brush head.

Adolescent↗

Three-month assessment of safety and efficacy of two electric toothbrushes.

OBJECTIVE: This randomised, examiner-blind parallel group study was designed to evaluate the safety and efficacy of a rechargeable oscillating/pulsating toothbrush (Oral-B ProfessionalCare 7000, Oral-B Laboratories; PC 7000) and a battery-operated toothbrush (Crest SpinBrush Pro, Procter & Gamble Company; SBP) in the reduction of gingivitis, bleeding and plaque over a 3-month period. METHODS: After 12-18 hours of no oral hygiene, subjects had oral tissue examinations, and gingival and plaque assessments to determine eligibility in the study. Subjects were stratified and randomised into treatment groups based on initial whole mouth mean plaque (Turesky modification of Quigley Hein Plaque Index) and gingivitis (Löe & Silness Gingival Index) scores and gender. Subjects were instructed to brush twice daily with their assigned toothpaste and toothbrush. Clinical parameters were assessed at baseline, and after 1 and 3 months of use. Within treatment comparisons from baseline were analysed using t-test; between treatment comparisons were analysed using ANOVA. RESULTS: Data were obtained from 92 subjects (PC 7000 n=45; SBP n=47). No significant differences were found in baseline plaque, gingivitis and bleeding between groups. Both treatment groups had significant reductions from baseline in plaque, gingivitis and bleeding scores. PC 7000 demonstrated significantly greater reductions compared to SBP in whole mouth plaque at 1 month: 0.39 +/- 0.43 vs. 0.16 +/- 0.42 and 3 months: 0.32 +/- 0.48 vs. 0.04 +/- 0.41. PC 7000 also demonstrated significant reductions compared to SBP in gingivitis at 3 months for whole mouth: 0.14 +/- 0.09 vs. 0.10 +/- 0.10 and approximal areas: 0.11 +/- 0.08 vs. 0.08 +/- 0.09. There were no significant differences between toothbrushes in bleeding at either time point: Safety examinations revealed no apparent difference in soft and hard tissue abnormalities between groups. CONCLUSION: The PC 7000 toothbrush demonstrated significantly greater reductions in plaque and gingivitis compared to the SPB over a 3-month period.

Adolescent↗

Efficacy of a novel brush head in the comparison of two power toothbrushes on removal of plaque and naturally occurring extrinsic stain.

OBJECTIVES: To compare the safety and efficacy of an oscillating/pulsating power toothbrush (Oral-B ProfessionalCareTM 7000; PC 7000) fitted with either the standard FlexiSoft (PC 7000/EB17) brush head or the novel Pro Polisher (PC 7000/ EB-Prophy) and a high-frequency toothbrush (Philips Sonicare Elite; SE), in their relative ability to remove plaque and naturally occurring extrinsic dental stain over a six-week period. METHODS: This randomised, examiner-blind, parallel group study involved 90 healthy subjects from a general population. All subjects received a baseline plaque (Turesky et al. modified Quigley-Hein Plaque Index), stain (Lobene Stain Index) and tooth shade (VITAPAN Shade Guide) [Vita] assessment and an oral tissue examination. After training in the use of their randomly assigned device, subjects were instructed to brush twice daily for 2 min and returned after 3, 4 and 6 weeks of product use for a repeat of each clinical assessment. RESULTS: Reductions from baseline in mean plaque and extrinsic dental stain scores were significant at Weeks 3, 4 and 6 in all three treatment groups. By Week 6, mean reductions from baseline in whole mouth plaque scores were 32%, 27% and 14% in the PC 7000/EB-Prophy, PC 7000/EB17 and SE groups, respectivety. For the body of the tooth, mean reductions from baseline at Week 6 in total stain were 89%, 89% and 80%, respectively. Between treatment group comparisons consistently revealed that the PC 7000 toothbrush plus the EB-Prophy or EB17 brush head removed significantly more plaque and extrinsic stain (total stain, stain area and stain intensity) than the SE toothbrush at 3, 4 and 6 weeks. The EB-Prophy group had a greater proportion of subjects showing a 2-3+ change in Vita shade scores at each time point compared to the other two brushes; at Week 6 the proportions were 67% in the PC 7000/EB-Prophy group, 30% in the PC 7000/EB17 group, and 7% in the SE group. The PC 7000/EB17, PC 7000/EB-Prophy and the SE were found to be safe as used in the study. CONCLUSIONS: The oscillating/rotating/pulsating PC 7000 (fitted with either the standard EB17 or novel EB-Prophy brush head) is more effective at removal of plaque and naturally occurring extrinsic tooth stain, and the PC 7000 plus EB-Prophy in the improvement of tooth shade, than the high-frequency SE toothbrush.

Adolescent↗

Single-use plaque removal efficacy of three power toothbrushes.

OBJECTIVES.: To compare the safety and plaque removal efficacy of two oscillating/rotating/pulsating toothbrushes (Oral-B ProfessionalCaretrade mark 7000 [PC 7000] and Oral-B 3D Excel [3DE]) and a high-frequency toothbrush (Sonicare(R) Advance, Philips Oral Healthcare; SA) in a single-use, examiner-blind, three period crossover study. METHODS.: After refraining from all oral hygiene procedures for 23-25 hours, subjects received an oral tissue examination and those with pre-brushing whole mouth mean plaque scores 0.6 based on the Rustogi et al. Modified Navy Plaque Index were randomly assigned to treatment sequence. After brushing with the assigned toothbrush and a commercially available dentifrice for 2 minutes, oral tissues were then re-examined and post-brushing plaque scores recorded. Following a brief washout period between two additional visits, the above procedures were repeated with the two alternate toothbrushes. One examiner, blinded to the treatment sequence, performed all clinical measurements. RESULTS.: A total of 79 subjects (28 males and 51 females) were enrolled and completed the study. Each toothbrush was found to be safe and significantly reduced plaque levels after a single brushing. The PC 7000 and 3DE were equally more effective in plaque removal than the SA, at all tooth areas, reducing plaque by 59.0%, 59.7% and 51.8%, respectively on whole mouth surfaces, and by 67.5%, 67.8% and 59.4%, respectively on approximal surfaces. CONCLUSIONS.: The action of the oscillating/rotating/pulsating toothbrushes (Oral-B ProfessionalCare 7000 and Oral-B 3D Excel) was more effective in plaque removal than the high-frequency toothbrush (Sonicare Advance).

Journal Article↗

Plaque removal efficacy of two electric toothbrushes with different brush head designs.

OBJECTIVES.: To compare the safety and plaque removal efficacy of two electric toothbrushes, one a rechargeable oscillating/pulsating toothbrush with a small round brush head (Oral-B ProfessionalCaretrade mark 7000; PC 7000), the other a battery-operated toothbrush with a dual moving brush head (Crest(R) SpinBrushtrade mark Pro; SBP). METHODS.: The study had a randomised, examiner-blind, two-arm crossover design. All subjects received an oral prophylaxis and used both toothbrushes on alternating days for a two-week practice period. After abstaining from all oral hygiene procedures for 23-25 hours, subjects received an oral tissue examination and those with pre-brushing whole mouth mean plaque scores >/=0.60 measured by the Rustogi et al. Modified Navy Plaque Index were randomly assigned to treatment sequence. Subjects brushed with their assigned toothbrush for 2 minutes using a commercially available dentifrice. Oral tissues were then re-examined and post-brushing plaque scores recorded. After a brief washout period, the above procedures were repeated with the alternate toothbrush. One examiner, blinded to the treatment sequence, performed all clinical measurements. RESULTS.: A total of 70 subjects (24 males and 46 females) were enrolled and completed the study. Each toothbrush was found to be safe and significantly reduced plaque levels after a single brushing. The PC 7000 was significantly more effective in plaque removal than the SBP at all tooth areas, reducing whole mouth plaque by 61% versus 58% and plaque from approximal surfaces by 69% versus 65%, respectively. CONCLUSIONS.: The action of the oscillating/pulsating toothbrush with a small round brush head, Oral-B ProfessionalCare 7000, is more effective in plaque removal than the battery-operated Crest SpinBrush Pro toothbrush with a larger dual moving brush head.

Journal Article↗

Three-month assessment of safety and efficacy of two electric toothbrushes.

OBJECTIVE.: This randomised, examiner-blind parallel group study was designed to evaluate the safety and efficacy of a rechargeable oscillating/pulsating toothbrush (Oral-B ProfessionalCaretrade mark 7000, Oral-B Laboratories; PC 7000) and a battery-operated toothbrush (Crest(R) SpinBrushtrade mark Pro, Procter & Gamble Company; SBP) in the reduction of gingivitis, bleeding and plaque over a 3-month period. METHODS.: After 12-18 hours of no oral hygiene, subjects had oral tissue examinations, and gingival and plaque assessments to determine eligibility in the study. Subjects were stratified and randomised into treatment groups based on initial whole mouth mean plaque (Turesky modification of Quigley Hein Plaque Index) and gingivitis (Löe & Silness Gingival Index) scores and gender. Subjects were instructed to brush twice daily with their assigned toothpaste and toothbrush. Clinical parameters were assessed at baseline, and after 1 and 3 months of use. Within treatment comparisons from baseline were analysed using t-test; between treatment comparisons were analysed using ANOVA. RESULTS.: Data were obtained from 92 subjects (PC 7000 n=45; SBP n=47). No significant differences were found in baseline plaque, gingivitis and bleeding between groups. Both treatment groups had significant reductions from baseline in plaque, gingivitis and bleeding scores. PC 7000 demonstrated significantly greater reductions compared to SBP in whole mouth plaque at 1 month: 0.39+/-0.43 vs. 0.16+/-0.42 and 3 months: 0.32+/-0.48 vs. 0.04+/-0.41. PC 7000 also demonstrated significant reductions compared to SBP in gingivitis at 3 months for whole mouth: 0.14+/-0.09 vs. 0.10+/-0.10 and approximal areas: 0.11+/-0.08 vs. 0.08+/-0.09. There were no significant differences between toothbrushes in bleeding at either time point. Safety examinations revealed no apparent difference in soft and hard tissue abnormalities between groups. CONCLUSION.: The PC 7000 toothbrush demonstrated significantly greater reductions in plaque and gingivitis compared to the SPB over a 3-month period.

Journal Article↗

Efficacy of a novel brush head in the comparison of two power toothbrushes on removal of plaque and naturally occurring extrinsic stain.

OBJECTIVES.: To compare the safety and efficacy of an oscillating/pulsating power toothbrush (Oral-B ProfessionalCaretrade mark 7000; PC 7000) fitted with either the standard FlexiSoft (PC 7000/EB17) brush head or the novel Pro Polisher (PC 7000/EB-Prophy) and a high-frequency toothbrush (Philips Sonicare(R) Elite(R); SE), in their relative ability to remove plaque and naturally occurring extrinsic dental stain over a six-week period. METHODS.: This randomised, examiner-blind, parallel group study involved 90 healthy subjects from a general population. All subjects received a baseline plaque (Turesky et al. modified Quigley-Hein Plaque Index), stain (Lobene Stain Index) and tooth shade (VITAPAN(R) Shade Guide) [Vita] assessment and an oral tissue examination. After training in the use of their randomly assigned device, subjects were instructed to brush twice daily for 2 min and returned after 3, 4 and 6 weeks of product use for a repeat of each clinical assessment. RESULTS.: Reductions from baseline in mean plaque and extrinsic dental stain scores were significant at Weeks 3, 4 and 6 in all three treatment groups. By Week 6, mean reductions from baseline in whole mouth plaque scores were 32%, 27% and 14% in the PC 7000/EB-Prophy, PC 7000/EB17 and SE groups, respectively. For the body of the tooth, mean reductions from baseline at Week 6 in total stain were 89%, 89% and 80%, respectively. Between treatment group comparisons consistently revealed that the PC 7000 toothbrush plus the EB-Prophy or EB17 brush head removed significantly more plaque and extrinsic stain (total stain, stain area and stain intensity) than the SE toothbrush at 3, 4 and 6 weeks. The EB-Prophy group had a greater proportion of subjects showing a 2-3+ change in Vita shade scores at each time point compared to the other two brushes; at Week 6 the proportions were 67% in the PC 7000/EB-Prophy group, 30% in the PC 7000/EB17 group, and 7% in the SE group. The PC 7000/EB17, PC 7000/EB-Prophy and the SE were found to be safe as used in the study. CONCLUSIONS.: The oscillating/rotating/pulsating PC 7000 (fitted with either the standard EB17 or novel EB-Prophy brush head) is more effective at removal of plaque and naturally occurring extrinsic tooth stain, and the PC 7000 plus EB-Prophy in the improvement of tooth shade, than the high-frequency SE toothbrush.

Journal Article↗

Horizontal phase-space distortions arising from magnetic pulse compression of an intense, relativistic electron beam.

We report detailed measurements of the transverse phase space distortions induced by magnetic chicane compression of a high brightness, relativistic electron beam to subpicosecond length. A strong bifurcation in the phase space is observed when the beam is strongly compressed. This effect is analyzed using several computational models and is correlated to the folding of longitudinal phase space. The impact of these results on current research in collective beam effects in bending systems and implications for future short wavelength free-electron lasers and linear colliders are discussed.

Journal Article↗

Transgenic MUC1 interacts with epidermal growth factor receptor and correlates with mitogen-activated protein kinase activation in the mouse mammary gland.

MUC1 is a large (>400 kDa), heavily glycosylated transmembrane protein that is aberrantly expressed on greater than 90% of human breast carcinomas and subsequent metastases. The precise function of MUC1 overexpression in tumorigenesis is unknown, although various domains of MUC1 have been implicated in cell adhesion, cell signaling, and immunoregulation. Stimulation of the MDA-MB-468 breast cancer line as well as mouse mammary glands with epidermal growth factor results in the co-immunoprecipitation of MUC1 with a tyrosine-phosphorylated protein of approximately 180 kDa. We have generated transgenic lines overexpressing full-length (MMF), cytoplasmic tail deleted (DeltaCT), or tandem repeat deleted (DeltaTR)-human MUC1 under the control of the mouse mammary tumor virus promoter to further examine the role of MUC1 in signaling and tumorigenesis. Immunoprecipitation experiments revealed that full-length transgenic MUC1 physically associates with all four erbB receptors, and co-localizes with erbB1 in the lactating gland. Furthermore, we detected a sharp increase in ERK1/2 activation in MUC1 transgenic mammary glands compared with Muc1 null and wild-type animals. These results point to a novel function of increased MUC1 expression, potentiation of erbB signaling through the activation of mitogenic MAP kinase pathways.

Animals↗

Anatomic study of the medial neurovascular structures in relation to calcaneal osteotomy.

Medial displacement osteotomy of the calcaneous is commonly performed for stage II posterior tibial tendon insufficiency in an effort to improve the valgus deformity of the hindfoot. We performed an anatomic study examining the medial neurovascular anatomy and its relation to the osteotomy in an attempt to determine which structures may be at risk during the procedure. Calcaneal osteotomies were performed through a lateral approach on 22 fresh-frozen cadaver below-knee specimens. Dissection was then performed medially to identify the Medial Plantar Nerve (MPN), the Lateral Plantar Nerve (LPN), the Posterior Tibial Artery (PTA), and their respective branches. Measurements determined either 1) where the structure crossed the osteotomy or 2) if the structure did not cross, the closest perpendicular distance from the osteotomy and at which point along its length this occurred. Perpendicular distances were recorded in millimeters and position along the osteotomy as a percentage of the total length from the posterosuperior aspect. An average of four neurovascular structures crossed each osteotomy site (range 2 to 6), most of which were branches of the LPN or the PTA. The MPN did not cross in any of the specimens studied, the LPN crossed in one specimen, and the PTA crossed in two specimens. The MPN distributed no crossing branches. The calcaneal sensory branch of the LPN was identified and crossed in 86% of the cadavers at 19% (+/- 15%) along the osteotomy length. A more distal second branch of the LPN (Baxter's nerve) was identified and crossed in 95% of the specimens at 61% (+/ 20%) along the osteotomy length. A third crossing branch existed in one specimen. Each PTA distributed from zero to three branches which variably crossed the osteotomy at a point from 2% to 100% along its length. The PTA bifurcated in 77% of the specimens at 49% (+/- 9%) along the osteotomy length. A consistent finding in every specimen was the presence of two veins accompanying the PTA with one on either side. A number of medial neurovascular structures may be at risk when perfoming a calcaneal osteotomy through a lateral approach. A minimum of two structures crossed the osteotomy site at variable positions in this study, although most of these structures represented branches off of the LPN or the PTA, with the LPN and the PTA themselves crossing only infrequently. The authors recommend that the completion of the osteotomy through the medial calcaneal cortex be performed in a carefully controlled manner to reduce the risk of post-operative complications including pain, numbness, and hematoma formation.

Calcaneus↗

Biomechanical comparison of syndesmosis fixation with 3.5- and 4.5-millimeter stainless steel screws.

Although most authors recommend either 3.5-mm or 4.5-mm cortical screws for syndesmosis fixation, the optimum screw size has yet to be defined. The present study was designed to biomechanically compare syndesmosis fixation with 3.5-mm and 4.5-mm stainless steel screws. Simulated pronation external rotation ankle injuries were created in twelve paired, fresh-frozen cadaveric leg specimens. One limb from each pair received a 3.5-mm tricortical stainless steel screw for syndesmosis fixation (group I), while the contralateral specimen was stabilized using a 4.5-mm screw (group II). Sub-maximal axial ramp (0 to 1200 N) and external rotation/torsional ramp (0 to 5 N-m) loading was performed on each specimen prior to ligament division, following ligament division and following syndesmosis fixation. Axial fatigue testing was then performed at 1.5 Hz for a total of 100,000 cycles (0 to 900 N), and each specimen was subsequently tested to failure in external rotation. Ligament division resulted in syndesmosis widening (p<0.001) and reduced stiffness (p<0.001) during torsional ramp loading. Subsequent syndesmosis screw placement reduced syndesmosis widening (p<0.05) and increased stiffness (p<0.05). Following screw fixation, however, widening remained greater (p<0.005) and stiffness less (p<0.001) than pre-injury levels. No differences between groups I and II were observed during submaximal testing. In external rotation to failure testing, group I failed at a greater angle (38.9 degrees +/- 4.1 degrees vs. 32.0 degrees +/- 3.8 degrees in group II; p<0.05). Failure torque was slightly higher in group I; however, the difference was not statistically significant (17.8 +/- 2.0 N-m vs. 14.3 +/- 2.6 N-m in group II; p=0.082). Five specimens in group I failed by screw pullout and five specimens in group II failed by fibula fracture (p=0.061). The present results suggest that there is no biomechanical advantage of a 4.5-mm screw over a 3.5-mm in fixation of the syndesmosis.

Aged↗

Evaluation of the infant at risk for neurodevelopmental disability.

BACKGROUND: Infants with neurodevelopmental abnormality need to start therapy early, and because of this they should be detected as soon as possible. Currently, no widely accepted method of early evaluation exists. OBJECTIVES: To assess and compare, in terms of predicting neurodevelopmental outcome at 1 year of age: (i) a perinatal risk rating (PRR); (ii) the Dubowitz Neurological Assessment (DNA); and (iii) the Infant Neuromotor Assessment (INA). DESIGN AND SETTING: A prospective neurodevelopmental follow-up study on graduates from the Groote Schuur Hospital (GSH) neonatal intensive care unit (NICU). SUBJECTS: A cohort of 130 consecutive NICU graduates were selected according to high-risk criteria. OUTCOME MEASURES: Each infant was examined at term gestational age on the DNA before discharge, and a PRR was allocated. Study infants were seen again at 18 weeks of age when an INA was done, and at 1 year of age a Griffiths Developmental Assessment and full neurological examination was carried out. RESULTS: All of the 130 infants assessed at term were seen at 18 weeks. Thereafter 5 were lost to follow-up and 2 died. The outcome for the remaining 123 is known. CONCLUSIONS: Prediction of a normal outcome at 1 year of age was 96% on the DNA and 98% for the PRR, but for an abnormal outcome they predicted only 56% and 42%, respectively. The INA done at 18 weeks predicted a normal outcome at 1 year in 99% of cases if 3 or less abnormal signs were present and an abnormal outcome in 82% of cases with 4 or more abnormal signs. Based on these findings a protocol for follow-up of these high-risk infants is suggested.

Developmental Disabilities↗

Growth hormone-releasing hormone depletion in the female rat: similarities to aging.

The age-related decline in growth hormone (GH) secretion has been largely attributed to age-related degeneration of hypothalamic growth hormone-releasing hormone (GHRH)-producing neurons. GH decline has recently been linked to age-related bone changes in humans. Bone loss and decreased bone strength are common in aging rats and humans, but density of remaining mineral tissue is known to be increased. The effect of induced hypothalamic GHRH deficiency on bone was assessed, and similarities between bone changes encountered and those taking place in aging were identified. Female rats received monosodium glutamate (MSG) following birth, and they were euthanized at 19 weeks of age. Femurs from MSG-treated rats had greater mineral density (p < .05), greater mineral/matrix ratio (p < .01), lower mineral apposition rate (p < .005), and lower bone formation rate (p < .05). These results suggest that hypothalamic GHRH decline plays a substantial role in the development of bone pathology similar to that observed in aging individuals.

Aging↗

Implementation of an inpatient case management program in rural hospitals.

The objective of the study was to identify factors that affected the implementation of an inpatient case management program in rural hospitals. The hospitals studied were from the Western New York Rural Health Care Cooperative. Five of the hospitals implemented the program in 1992. A qualitative evaluation was conducted by analyzing tape-recorded interviews with nurses and chief executive officers to identify obstacles to and facilitators of program implementation. Many obstacles to implementation could be traced to workload and time constraints, physician autonomy concerns, and limited nursing staff and physician participation. Implementation was facilitated foremost by the effort and supportive attitudes of nursing leaders and hospital chief executive officers. This study concluded that it should be possible to successfully implement conceptually sound managed care and case management programs in rural hospitals, but it will require a relatively long period of support, especially from hospital administration and nursing leaders.

Case Management↗