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Results for “stepping”

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At least 19 recordsLinked to original sources

PubMed2003

Microtensile bond strength of a total-etch 3-step, total-etch 2-step, self-etch 2-step, and a self-etch 1-step dentin bonding system through 15-month water storage.

PURPOSE: To evaluate dentin bond durability using current dentin adhesive resin bonding approaches over a 15-month period of water storage. MATERIALS AND METHODS: Forty-four extracted human molars were polished with 600-grit SiC papers exposing occlusal dentin, and randomly distributed into four adhesive groups: total-etch 3-step (TE3) (Scotchbond Multi-Purpose, 3M ESPE), total-etch 2-step (TE2) (Single Bond, 3M ESPE), self-etch 2-step (SE2) (Clearfil SE Bond, Kuraray), and a self-etch 1-step (SE1) (Prompt L-Pop, 3M ESPE). A resin composite crown was incrementally formed and light cured to approximately 6 mm in height. Microtensile specimens were fabricated and stored in distilled water containing 0.5% chloramine T and tensile tested at 1 mm/min after 1, 6, and 15 months. The debond pathway was recorded as either involving the substrate or joint using scanning electron microscopy. SAS software was used to compute Weibull parameters and distributions, Log-rank and Wilcoxon tests were used for comparison of survival curves over time for each adhesive system and between adhesive systems. RESULTS: The TE2 was significantly weaker than TE3 and SE2 after 1 and 6 months of storage, but all three systems were equivalent after 15 months of storage. The SE1 system could not be tested due to 58 of 65 specimens failing during specimen preparation. Failure modes were observed to be dependent upon adhesive system, with only the total-etch 2-step system demonstrating an increasing involvement in the adhesive joint over time. CONCLUSION: Although differences in bond strength were observed across adhesive systems up to 6 months of storage, no differences were noted at 15 months. This may represent common degradative mechanisms.

Acid Etching, Dental↗

PubMed2004

Step width variability, but not step length variability or step time variability, discriminates gait of healthy young and older adults during treadmill locomotion.

The variability of spatial and temporal step kinematics have separately been shown to prospectively predict falls by older adults. However, the published literature has not addressed the relative importance of the information related to locomotion control contributed by variability of spatial variables, temporal variables, or both. We conducted a post hoc analysis to determine the extent to which the variability of spatial and temporal step kinematics are independent descriptors of locomotion control in healthy young and older adults. A second purpose of the analysis was to establish the extent to which treadmill walking mimics overground walking using a benchmark for step kinematics. Eighteen young adults and 12 older adults walked at a self-selected velocity on an instrumented treadmill from which step length variability, step width variability and step time variability were computed. Stepwise discriminant analysis correctly classified group membership of 70 percent of the 30 subjects (i.e., young or older adult) using only step width variability (p=0.037, Wilk's lamda=0.854). Step width variability was 70+/-57 percent larger than step length variability (p<0.001). This relationship was similar to that of the benchmark established for overground locomotion. The results suggest that for healthy younger and older adults step width variability is a more meaningful descriptor of locomotion control than step length variability and step time variability. Given the potential clinical impact, further systematic study and improvement of the methods and technology for acquiring step kinematic data are warranted.

Adult↗

PubMed2001

Elderly subjects' ability to recover balance with a single backward step associates with body configuration at step contact.

BACKGROUND: In the event of a slip or trip, one's ability to recover a stable upright stance by stepping should depend on (a) the configuration of the body at the instant of step contact and (b) the forces generated between the foot and ground during step contact. In this study, we tested whether these two variables associate with elderly subjects' ability to recover balance by taking a single backward step after sudden release from an inclined position. METHODS: Twenty-six community-dwelling subjects (12 women, 14 men) of mean age 75+/-4 (SD) years each underwent five trials in which they were suddenly released from a backward inclination of 7 degrees and instructed to "recover balance with a single step." Body segment motions and foot contact forces were analyzed to determine step contact times, stepping angles, body lean angles at step contact, and the magnitudes and times (after step contact) of peak foot-floor contact forces and peak sagittal-plane torques at the ankle, knee, and hip of the stepping leg. RESULTS: Fifty percent of subjects were predominantly single steppers (successful at recovering with a single step in greater than three of five trials), 27% were multiple steppers (successful in less than two of five trials), and 23% were mixed response steppers (successful in two of five or three of five trials). Recovery style associated with the ratio of stepping angle divided by body lean angle at step contact (p = .003), which averaged 1.4+/-0.5 for single steppers and 0.6+/-0.5 for multiple steppers, but not with step contact time, stepping angle, or contact forces and joint torques during step contact. CONCLUSIONS: These results suggest that elderly subjects' ability to recover balance with a single backward step depends primarily on the configuration of the body (in particular, the ratio of stepping angle to body lean angle) at step contact.

Aged↗

PubMed2004

Interaction of step length and step rate during sprint running.

UNLABELLED: A "negative interaction" between step length and step rate refers to an increase in one factor resulting in a decrease in the other. PURPOSES: There were three main purposes: a) to investigate the relative influence of the determinants of step length and step rate, b) to determine the sources of negative interaction between step length and step rate, and c) to investigate the effects of manipulation of this interaction. METHODS: Thirty-six athletes performed maximal-effort sprints. Video and ground reaction force data were collected at the 16-m mark. Sprint velocity, step length, step rate, and their underlying determinants were calculated. Analyses included correlations, multiple linear regressions, paired t-tests, and a simple simulation based on alterations in flight determining parameters. RESULTS: A wide range of step length and step rate combinations was evident, even for subgroups of athletes with similar sprint velocities. This was partly due to a negative interaction that existed between step length and step rate; that is, those athletes who used a longer step length tended to have a lower step rate and vice versa. Vertical velocity of takeoff was the most prominent source of the negative interaction. CONCLUSIONS: Leg length, height of takeoff, and vertical velocity of takeoff are all possible sources of a negative interaction between step length and step rate. The very high step lengths and step rates achieved by elite sprinters may be possible only by a technique that involves a high horizontal and low vertical velocity of takeoff. However, a greater vertical velocity of takeoff might be of advantage when an athlete is fatigued and struggling to maintain a high step rate.

Adult↗

PubMed2001

Intrinsic bending and deformability at the T-A step of CCTTTAAAGG: a comparative analysis of T-A and A-T steps within A-tracts.

Introduction of a T-A or pyrimidine-purine step into a straight and rigid A-tract can cause a positive roll deformation that kinks the DNA helix at that step. In CCTTTAAAGG, the central T-A step has an 8.6 degrees bend toward the major groove. We report the structural analysis of CCTTTAAAGG and a comparison with 25 other representative crystal structures from the NDB containing at least four consecutive A or T bases. On average, more local bending occurs at the disruptive T-A step (8.21 degrees ) than at an A-T step (5.71 degrees ). In addition, A-tracts containing an A-T step are more bent than are pure A-tracts, and hence A-A and A-T steps are not equivalent. All T-A steps examined exhibit positive roll, bending towards the major groove, while A-T steps display negative roll and bend slightly towards the minor groove. This illustrates how inherent negative and positive roll are, respectively, at A-T and T-A steps within A-tracts. T-A steps are more deformable, showing larger and more variable deformations of minor groove width, rise, cup, twist, and buckle. Standard deviations of twist, rise, and cup for T-A steps are 6.66 degrees, 0.55 A, and 15.90 degrees, versus 2.28 degrees, 0.21 A, and 2.99 degrees for A-T steps. Packing constraints determine which local values of these helical parameters an individual T-A step will adopt. For instance, with CCTTTAAAGG and three isomorphous structures, CGATTAATCG, CGATATATCG, and CGATCGATCG, crystal packing forces lead to a series of correlated changes: widened minor groove, large slide, low twist, and large rise. The difference in helical parameters between A-T steps lying within A-tracts, versus A-T steps within alternating AT sequences, demonstrates the importance of neighboring steps on the conformation of a given dinucleotide step.

AT Rich Sequence↗

PubMed2003

Step training improves the speed of voluntary step initiation in aging.

BACKGROUND: Falls related to balance dysfunction are among the major problems of older individuals. The timing characteristics of protective voluntary stepping are critically related to effective balance recovery and are often delayed and slowed with age. This study investigated the influence of step training on the timing characteristics of voluntary step initiation in younger and older adults. METHODS: Voluntary reaction time stepping was evaluated before and after training in 12 younger adults and 8 healthy community-dwelling older adults who performed a 3-week regimen of either twice weekly induced step training (destabilizing large waist pulls) or voluntary step practice to a somatosensory reaction stimulus cue (nondestabilizing small waist pulls). RESULTS: Overall, the first step initiation times were slower for the older than for the younger subjects for both the somatosensory reaction stimulus cue task and an auditory transfer cue task. Step completion time was completed earlier for the young posttraining subjects, and older subjects generally had a longer step length. Training resulted in significant reductions in step initiation timing for the old (17%) and young (15%) subjects. Across age groups, the induced training group showed greater reductions in step initiation time than the voluntary practice group for the auditory transfer cue task. CONCLUSIONS: A 3-week period of either voluntary or waist-pull-induced step training reduced step initiation time in older and younger adults. Moreover, compared with voluntary step practice, induced step training resulted in a significantly greater improvement in reaction time stepping for an auditory transfer cue task. At least in the short term, such step training has the potential to help older adults perform more like younger adults in their step initiation timing.

Accidental Falls↗

PubMed2003

A comparative randomized multicentric study comparing the step-up versus step-down protocol in polycystic ovary syndrome.

BACKGROUND: The aim of the study was to evaluate follicular development and ovulation comparing the low-dose step-up and the step-down protocols, in women with clomiphene citrate (CC)-resistant polycystic ovaries. METHODS: Eighty-three women were randomized, and treated with recombinant (r) FSH (Puregon) using either the step-up (n=44) or step-down (n=39) protocol. They were followed up for three cycles unless pregnancy occurred. RESULTS: Monofollicular development occurred in 68.2% of the 85 cycles in the step-up group, as compared with 32% of the 72 cycles in the step-down group (P<0.0001). Hyperstimulation was statistically less frequent using the step-up procedure (4.7 versus 36%, P<0.0001). Both protocols used the same number of FSH units per cycle (951+/-586 versus 967+/-458 in step-up and step-down respectively, P=not significant). However, the duration of ovarian stimulation was statistically different (15.2+/-7.0 days in step-up versus 9.7+/-3.1 in step-down, P<0.001). Ovulation was observed in 70.3% of the cycles using the step-up procedure as compared with 51.3% using the step-down procedure (P<0.01). The cumulative rate of clinical gestations during the study did not differ between the two groups (38.6% in the step-up versus 30.8% in the step-down procedure). CONCLUSIONS: The step-up protocol using rFSH (Puregon), is more efficient in obtaining a monofollicular development and ovulation than the step-down protocol, in women with CC-resistant polycystic ovaries. Although the duration of stimulation is longer, the rate of ovarian hyperstimulation is much lower using the step-up protocol.

Adult↗

PubMed1990

[The use of a test phantom in step-shaped forms (test steps) for the clarification of different problem situations in x-ray diagnosis. 1. The use of test steps for the estimation of image quality after modified darkroom technics].

Properly exposed radiographs and under- or overexposed ones were processed differently with regard to temperature and time. Using a step wedge for the objective estimation, the alteration of well-exposed radiographs by neglecting time and temperature control was examined. Further information is given about the possibility to improve the quality of wrongly exposed radiographs by manipulation of the processing, and about the quantity of acceptable radiographs received in this way. Stop bath, fixation bath, wash bath and drying were performed regularly. The result showed, that the only chance to get high quality radiographs is by exact and correct working.

Animals↗

PubMed2002

Effects of age, step direction, and reaction condition on the ability to step quickly.

BACKGROUND: The ability to take a step quickly is important for balance maintenance during activities of daily living. The purpose of this study was to investigate the effects of age, reaction condition, and step direction on the ability to take a volitional step as fast as possible. METHODS: The performance of a voluntary step task was measured in young adult (mean age 20, SD 0.9 years), young-old adult (mean age 67, SD 3.7 years), and old adult (mean age 78, SD 2.3 years) healthy female participants. Each participant stepped as fast as possible in eight directions in response to a visual cue in a simple or choice reaction time condition. The effects of age, reaction condition, and step direction and their interactions on the primary outcome variables of response time, step liftoff, and step landing time were examined. RESULTS: The normal aging process progressively increased the response, liftoff, and landing times. The choice reaction time condition, compared to the simple, had significantly increased response, liftoff, and landing times. Step direction significantly affected the liftoff and landing times, with lateral, diagonal, and anterior and posterioir (A-P) times increasing, respectively. CONCLUSIONS: We found substantial declines in the ability to step rapidly in healthy adults as age increased. When a decision was required regarding the step direction, the step performance also declined. Step direction also significantly affected step performance. The assessment of voluntary step performance, which may be an indicator of balance ability, should include dimensions of both direction and the choice condition.

Adult↗

PubMed1982

Interlimb coordination during stepping in the cat: in-phase stepping and gait transitions.

The coordination of step cycles between all 4 limbs during in-phase stepping and during transitions to and from alternate stepping was studied in 12 adult cats during repeated overground stepping trials. The temporal spacing of step cycles of the different limbs was determined from analysis of electromyographic (EMG) activity in a single extensor muscle of each limb. Patterns of coordination of the different limbs were established on the basis of the frequency with which phase values separating step cycles were encountered. Steps in which the phasing of step cycles of the two hindlimbs were closer to true in-phase coordination than true alternation (phase between 270 degrees and 90 degrees) and where similar coupling was found in both the preceding and following steps were defined as steady state conditions. Distinct patterns of coordination of forelimb-forelimb and forelimb-hindlimb step cycles were noted under steady state conditions. During stepping sequences which include transitions either to or from alternate stepping, both gradual and abrupt phase changes were found. The changes in both forelimb-forelimb and forelimb-hindlimb phase relationships were more often gradual than abrupt. Where abrupt changes were encountered in the change in phase relationships between one such limb pair the phase change in the other pair was gradual. Changes in hindlimb-hindlimb phase relationships during transitions were nearly always abrupt. It is concluded that the 4 limbs are coordinated during in-phase stepping according to a few patterns, but that the variability about these patterns makes their association with simple neural circuitry rather speculative. The finding that transitions were most often gradual is interpreted in terms of a state-dependent model of interlimb control, in which the type of transition utilized depends on the strength of neural coupling of step cycles of all 4 limbs at the time that the transition is initiated.

Animals↗

PubMed2004

Comparison of procedural errors resulting during root canal preparations completed by senior dental students in patients using an '8-step method' versus 'serial step-back technique'.

OBJECTIVE: To compare procedural errors that occur in patients during root canal preparation by senior dental students using a new '8-step method' versus the traditional 'serial step-back technique.' STUDY DESIGN: Senior dental students treated 221 root canals of maxillary and mandibular teeth. Instrumentation included coronal flaring with Gates-Glidden reamers and standardized stainless steel K-files in all teeth. A new 8-step method was used to prepare 67 canals using standardized stainless steel hand instruments (8-step SS) and 69 canals using the rotary Nickel Titanium instruments (8-step NiTi). The traditional serial step-back technique (step-back) was used for 85 root canals. In the apical third, reaming or filing motions were used up to sizes 25 and only reaming motion in sizes larger than 25 with the new 8-step method. A filing motion was used in the step-back for all sizes. Root canals of all groups were obturated with gutta-percha points and AH26 using a lateral condensation technique. Pre- and postoperative radiographs were taken of each tooth. Procedural errors were recorded and statistically analyzed using a binomic test for comparison of proportion. RESULTS: Procedural errors detected consisted of 2 canals with transportation (3%) with the 8-step SS, and 3 canals (4%) with transportation with 8-step NiTi. There were no canal obstructions or instrument separations. With the step-back, 20 canals were transported (24%), 7 canals had obstructions (8%), and in 1 canal instrument was separated (1%). CONCLUSIONS: The new 8-step method resulted in fewer procedural errors than the traditional serial step-back technique when senior students prepared root canals in patients either by hand with standardized K-files or by rotary NiTi instrumentation.

Bismuth↗

PubMed2003

Can primary care doctors prescribe exercise to improve fitness? The Step Test Exercise Prescription (STEP) project.

BACKGROUND: Sedentary lifestyle is associated with adverse health outcomes. Available evidence suggests that, despite positive attitudes toward regular exercise in promoting a healthy lifestyle, few physicians actually prescribe exercise for their patients. Barriers include lack of skills and standard office instruments. Because primary care physicians have regular contact with a large proportion of the population, the impact of preventive health interventions may be great. OBJECTIVES: To determine the effect of an exercise prescription instrument (i.e., Step Test Exercise Prescription [STEP]), compared to usual-care exercise counseling delivered by primary care doctors on fitness and exercise self-efficacy among elderly community-dwelling patients. DESIGN: Randomized controlled trial; baseline assessment and intervention delivery with postintervention follow-up at 3, 6, and 12 months. SETTING: Four large (>5000 active patient files) academic, primary care practices: three in urban settings and one in a rural setting, each with four primary care physicians; two clinics provided the STEP intervention and two provided usual care control. PARTICIPANTS: A total of 284 healthy community-dwelling patients (72 per clinic) aged >65 years were recruited in 1998-1999. INTERVENTION: STEP included exercise counseling and prescription of an exercise training heart rate. MAIN OUTCOME MEASURES: The primary outcome measure was aerobic fitness (VO(2max)). Secondary outcomes included predicted VO(2max) from the STEP test, exercise self-efficacy (ESE), and clinical anthropometric parameters. RESULTS: A total of 241 subjects (131 intervention, 110 control) completed the trial. VO(2max) was significantly increased in the STEP intervention group (11%; 21.3 to 24ml/kg/min) compared to the control group (4%; 22 to 23ml/kg/min) over 6 months (p <0.001), and 14% (21.3 to 24.9ml/kg/min) and 3% (22.1 to 22.8ml/kg/min), respectively, at 12 months (p <0.001). A similar significant increase in ESE (32%; 4.6 vs 6.8) was observed for the STEP group compared to the control group (22%; 4.2 vs 5.4) at 12 months (p < 0.001). Systolic blood pressure decreased 7.3% and body mass index decreased 7.4% in the STEP group, with no significant change in the control group (p <0.05). Exercise counseling time was significantly (p <0.02) longer in the STEP (11.7+/-3.0 min) compared to the control group (7.1+/-7.0 min), but more (p <0.05) subjects completed > or =80% of available exercise opportunities in the STEP group. CONCLUSIONS: Primary care physicians can improve fitness and exercise confidence of their elderly patients using a tailored exercise prescription (e.g., STEP). Further, STEP appears to maintain benefits to 12 months and may improve exercise adherence. Future study should determine the impact of combining cognitive/behavior change strategies with STEP.

Aged↗

PubMed2004

Online mutability of step direction during rapid stepping reactions evoked by postural perturbation.

Stepping reactions are often triggered rapidly in response to loss of balance. It has been unclear whether spatial step parameters are defined at time of step-initiation or whether they can be modulated online, during step execution, in response to sensory feedback about the evolving state of instability. This study explored the capacity to actively alter step direction subsequent to step initiation in six healthy young-adult subjects. To elicit forward-step reactions, subjects were released suddenly from a tethered forward lean. A second perturbation (medio-lateral support-surface translation) was applied at lags of 0-200 ms. Active reaction to the second perturbation was determined primarily through analysis of swing-leg hip-abductor activation. In addition, to gauge the biomechanical consequence of the changes in muscle activation, we compared the measured medio-lateral swing-foot displacement to that predicted by a simple passive mechanical model. Perturbations at 0-100 ms lag evoked active medio-lateral swing-foot deviation, allowing balance to be recovered with a single step. However, when the second perturbation occurred near foot-off (200-ms lag), there was no evidence of active alteration of step direction and subjects typically required additional steps to recover balance. The results suggest that step direction can be reparameterized during early stages of stepping reactions, but that step direction was not actively modulated in response to perturbation arising near start of swing phase.

Acceleration↗

PubMed1997

Urinary follicle-stimulating hormone for normogonadotropic clomiphene-resistant anovulatory infertility: prospective, randomized comparison between low dose step-up and step-down dose regimens.

A low dose step-up and step-down regimen for induction of ovulation using urinary FSH was compared in a prospective randomized fashion in 37 normogonadotropic clomiphene-resistant oligo- or amenorrheic infertile women. The objectives was to assess potential differences in duration of treatment, ovarian stimulation (serum FSH levels), and response [serum estradiol (E2) levels and number and size of follicles]. Monitoring (blood sampling and transvaginal sonography) took place on the day of initiation of treatment, the first day of ovarian response as assessed by ultrasound (i.e. the first day a follicle > or = 10 mm could be recognized), the day of hCG administration to induce ovulation, and 3 days thereafter. The median duration of treatment in the low dose step-up group was 18 (range, 7-41) days compared to 9 (range, 4-16) days in the step-down group (P = 0.003), and the total numbers of ampules administered were 20 (range, 7-69) and 14 (range, 7-33), respectively (P = NS). Serum FSH levels from the first day of sonographic ovarian response until the administration of hCG were constant (median increase, 2%/day) in patients receiving the low dose step-up protocol, but showed a decrease (median, 5%/day) in step-down cycles (P < 0.001). Monofollicular growth, defined as not more than one follicle 16 mm or larger on the day of hCG administration, was observed in 56% of low dose step-up and 88% of step-down cycles (P = 0.04). The percentage of patients with normal range periovulatory E2 serum levels (500-1500 pmol/L) was 33% in the low dose step-up group vs. 71% in the step-down group (P = 0.03). We conclude that a step-down protocol for gonadotropin induction of ovulation exhibits a more physiological, late follicular phase FSH serum profile than a low dose step-up protocol. This results in a shorter duration of treatment, a greater number of monofollicular cycles, and more cycles with periovulatory E2 levels within the normal range in the step-down protocol.

Adult↗

PubMed1983

Effect of step-down and step-up protein-energy feeding systems on egg-type pullet growth and laying performance.

Four egg-type pullet feeding systems were compared for the production of egg-type pullets. The dietary regimens consisted of either a step-down protein, high energy feeding program; a step-down protein, low energy program; a step-up protein, high energy program; or a step-up protein, low energy program. At 150 days of age all pullets were housed 2 birds per 25.4 X 45.7 cm laying cage and fed a standard layer diet (16% protein). The experiment utilized 2880 birds grown on the floor in a conventional growing house. At 140 days of age, birds subjected to the step-up protein feeding programs were 82 g smaller in mean body weight, had higher mortality, and consumed less feed than the birds on the step-down protein feeding programs. Body weights at 140 days of age were 1.17 and 1.09 kg for the step-down and step-up feeding programs, respectively. Energy levels fed had no significant effect on pullet weight, feed consumed, or mortality to 140 days of age. During the laying phase, hens that had been on the step-down protein feeding program reached 50% production 2.0 days earlier than birds subjected to the step-up protein feeding program. Hen-day production for the step-down and step-up pullet feeding systems based on 308 days' records was 76.09 and 76.86%, respectively. Feed efficiency and mature body weight were not significantly affected by grower feeding programs. The largest egg size and highest laying house mortality were noted in hens grown on the step-down protein feeding program.

Animals↗

PubMed2003

Measuring step kinematic variability on an instrumented treadmill: how many steps are enough?

Variability of step kinematics has been associated with falls by older adults. However, between-study differences with regard to the number of steps used to compute variability have varied by an order of magnitude. If the number of steps used to compute variability is too low there is the potential for a statistically spurious outcome. On the other hand, for subjects with mobility impairments a protocol requiring too many steps to estimate variability imposes an unnecessary burden on the subjects. We have determined the minimum number of steps needed to estimate the variability of spatial and temporal step kinematics. More than 700 steps were collected during level walking on an instrumented treadmill. Accurate estimation of step kinematic variability required at least 400 steps. The increased error in estimating the mean and standard deviations of the step kinematic variables with too few steps can impose an experimental cost with regard to statistical design considerations. The extent to which translation of these results can be made to the variability of spatial and temporal step kinematics collected during over-ground walking awaits further research.

Adult↗

PubMed2001

Influence of curriculum type on student performance in the United States Medical Licensing Examination Step 1 and Step 2 exams: problem-based learning vs. lecture-based curriculum.

INTRODUCTION: The results of the United States Medical Licensing Examination Step 1 and 2 examinations are reported for students enrolled in a problem-based and traditional lecture-based curricula over a seven-year period at a single institution. There were no statistically significant differences in mean scores on either examination over the seven year period as a whole. There were statistically significant main effects noted by cohort year and curricular track for both the Step 1 and 2 examinations. These results support the general, long-term effectiveness of problem-based learning with respect to basic and clinical science knowledge acquisition. CONTEXT: This paper reports the United States Medical Licensing Examination Step 1 and Step 2 results for students enrolled in a problem-based and traditional lecture-based learning curricula over the seven-year period (1992-98) in order to evaluate the adequacy of each curriculum in supporting students learning of the basic and clinical sciences. METHODS: Six hundred and eighty-nine students who took the United States Medical Licensing Examination Step 1 and 540 students who took Step 2 for the first time over the seven-year period were included in the analyses. T-test analyses were utilized to compare students' Step 1 and Step 2 performance by curriculum groups. RESULTS: United States Medical Licensing Examination Step 1 scores over the seven-year period were 214 for Traditional Curriculum students and 208 for Parallel Curriculum students (t-value = 1.32, P=0.21). Mean Step 2 scores over the seven-year period were 208 for Traditional Curriculum students and 206 for Parallel Curriculum students (t-value=1.08, P=0.30). Statistically significant main effects were noted by cohort year and curricular track for both the Step 1 and Step 2 examinations. CONCLUSION: The totality of experience in both groups, although differing by curricular type, may be similar enough that the comparable scores are what should be expected. These results should be reassuring to curricular planners and faculty that problem-based learning can provide students with the knowledge needed for the subsequent phases of their medical education.

Curriculum↗

PubMedDate not supplied

Step-down and step-up therapy in moderate persistent asthma.

BACKGROUND: A step-down therapy may be more beneficial for the management of asthma than a step-up therapy. METHODS: Eighty-two asthmatic patients with moderate persistent asthma were enrolled in the study and randomized into three groups. One group of patients received 400 microg/day of beclomethasone dipropionate (BDP) for 4 weeks and then 800 microg/day for another 4 weeks (step-up group). The other two groups of patients received 1,200 microg/day of BDP for 4 weeks with or without short-term oral steroid (prednisolone, 0.5 mg/day for 1 week) and then 800 microg/day for another 4 weeks (step-down group). Severe exacerbation of asthma, asthma symptoms, respiratory function and rescue use of inhaled beta(2)-agonists were monitored. If asthma was well controlled, the dose of BDP was decreased every 3 months and if asthma was exacerbated, the dose of BDP was increased until 8 months after the initial treatment. RESULTS: Twenty-two patients during the run-in period, 4 patients in the step-up group, 2 patients in the step-down group treated with a high dose of BDP and no patients in the step-down group with oral steroids during first 4 weeks dropped out because of severe exacerbation of asthma. Although asthma symptoms and respiratory function significantly improved 8 weeks after the therapy in all groups, more significant and prompt improvements of these parameters were observed in patients of the step-down group than in patients of the step-up group after the first 2 weeks of treatment. Furthermore, step-down therapy with short-term oral steroid resulted in the lowest maintenance doses of BDP at 8 months of the three groups. CONCLUSIONS: These results suggest that step-down therapy starting with a high dose of inhaled steroid and short-term oral steroid is more effective in gaining prompt control of asthma and reducing the severe exacerbation of asthma and the maintenance dose of inhaled steroids than a step-up therapy starting with a low dose of inhaled steroids in patients with moderate persistent asthma.

Administration, Inhalation↗