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PubMed2002

An event-related potential study on visual perceptual learning under short-term and long-term training conditions.

The present study investigated learning-induced changes of event-related potentials in a visual discrimination task, focusing on making a comparison between short-term and long-term learning perceptual processes. Event-related potentials were recorded from two groups of human adults. One group (short-term training group) was given 1.5 h of training in a single day, and another group (long-term training group) was given the same training procedure (1.5 hour of training) on each of 3 consecutive days. The results demonstrated that for short-term training group, along with the reduction of reaction times, the amplitudes of N1 and N2 negativities over the central/parietal areas decreased during the training. For long-term training group, however, after long-term training, the N2 effect disappeared and the N1 effect occurred over the posterior areas. In addition, the amplitudes of N2 for long-term training group were less than those for short-term training group. Our results suggest that neural activity depends not only on perceptual mechanisms and on the parameters of the physical stimuli but also on the extent of the observer's previous learning.

Adult↗
PubMed2004

A short-term and long-term comparison of root coverage with an acellular dermal matrix and a subepithelial graft.

BACKGROUND: Obtaining predictable and esthetic root coverage has become important. Unfortunately, there is only a limited amount of information available on the long-term results of root coverage procedures. The goal of this study was to evaluate the short-term and long-term root coverage results obtained with an acellular dermal matrix and a subepithelial graft. METHODS: An a priori power analysis was done to determine that 25 was an adequate sample size for each group in this study. Twenty-five patients treated with either an acellular dermal matrix or a subepithelial graft for root coverage were included in this study. The short-term (mean 12.3 to 13.2 weeks) and long-term (mean 48.1 to 49.2 months) results were compared. Additionally, various factors were evaluated to determine whether they could affect the results. This study was a retrospective study of patients in a fee-for-service private periodontal practice. The patients were not randomly assigned to treatment groups. RESULTS: The mean root coverages for the short-term acellular dermal matrix (93.4%), short-term subepithelial graft (96.6%), and long-term subepithelial graft (97.0%) were statistically similar. All three were statistically greater than the long-term acellular dermal matrix mean root coverage (65.8%). Similar results were noted in the change in recession. There were smaller probing reductions and less of an increase in keratinized tissue with the acellular dermal matrix than the subepithelial graft. None of the factors evaluated resulted in the acellular dermal graft having a statistically significant better result than the subepithelial graft. However, in long-term cases where multiple defects were treated with an acellular dermal matrix, the mean root coverage (70.8%) was greater than the mean root coverage in long-term cases where a single defect was treated with an acellular dermal matrix (50.0%). CONCLUSIONS: The mean results with the subepithelial graft held up with time better than the mean results with an acellular dermal matrix. However, the results were not universal. In 32.0% of the cases treated with an acellular dermal matrix, the results improved or remained stable with time.

Adult↗
PubMed1997

Factors influencing short-term and long-term pediatric renal transplant survival.

OBJECTIVE: To determine the patient and donor characteristics important for short-term and long-term renal transplant survival at Cincinnati Children's Hospital Medical Center. METHODS: Cumulative transplant survival was calculated and univariate analysis of graft survival performed on 206 transplants done since 1970 in 148 pediatric patients. Grafts to black recipients were analyzed separately. Short-term graft survival is defined as 1-year allograft survival and long-term graft survival as graft half-life (t1/2) survival for allografts functioning after the first posttransplant year. RESULTS: One-year graft survival of living-related donor (LRD) and cadaver donor (CAD) transplants was 77% and 62%, respectively. Graft t1/2 was 11.2 years for LRD and 9.8 years for CAD grafts. The CAD 1-year graft survival when the recipient or donor was younger than 7 years was 36% and 41%, respectively. The LRD 1-year graft survival to children younger than 7 years was 88% versus 75% in older children. Graft survival at 1 year was similar for CAD primary and retransplants (60% vs 65%), but graft t1/2 better for CAD primary grafts (17.8 years vs 5.0 years, P < 0.001). Preemptive LRD grafts performed similarity at 1 year and better over the long term compared with patients who had long-term dialysis (85% vs 74%, P = NS; and 16.9 years vs 8.0 years, p < 0.001). Preemptive CAD grafts did poorly, with 1-year graft survival of 38%. Administration of Cyclosporine A (CsA) improved CAD 1-year graft survival (76% vs 54%, p < 0.001) but not long-term survival. Thirty grafts to 24 black children had a 1-year survival of 48%, with no graft surviving more than 5 years. CONCLUSIONS: Living-related donor transplantation should be aggressively pursued for young children. If a LRD is unavailable and the young child's medical condition is stable, delay in CAD transplantation should be considered, with dialysis before transplant. Use of CsA improves 1-year pediatric graft survival, but does not improve graft survival after 1 year at the Children's Hospital Medical Center. New strategies to improve graft survival in black children should be pursued.

Adolescent↗
PubMed1994

Staurosporine impairs both short-term and long-term potentiation in the dentate gyrus in vitro.

The present study shows that the protein kinase inhibitor staurosporine impairs the transient (< 60 min) potentiation (short-term potentiation) evoked by a weak tetanus to about the same extent as the more stable potentiation (long-term potentiation) evoked by a strong tetanus. This effect on short-term and long-term potentiation was seen both as a reduced magnitude and an increased decay rate, the latter being increased by about 50% compared to that seen under normal conditions. Comparison with potentiations evoked at different strengths in control solution suggested that much, but not all, of the increased decay rate observed in the presence of staurosporine could be explained by an impared induction. Staurosporine did not affect the N-methyl-D-aspartate-mediated field excitatory postsynaptic potential evoked by low-frequency stimulation or the magnitude of N-methyl-D-aspartate-mediated currents during high-frequency tetanization. This result suggests that the induction is impaired at a stage not related to the N-methyl-D-aspartate-mediated calcium influx. The present results suggest that short-term and long-term potentiation cannot be separated on the basis of protein kinase dependence. They do not support the common notion that short-term and long-term potentiation are mechanistically separate entities. Instead, the results support the view that long-term potentiation has a variable duration/stability dependent on the induction conditions and that protein kinase activation, via an action on induction mechanisms, contributes to its stabilization.

Alkaloids↗
PubMed2002

Craniofacial features of patients with Class III abnormalities: growth-related changes and effects of short-term and long-term chincup therapy.

The craniofacial features of patients with Class III abnormalities, including growth-related changes and effects of short-term and long-term chincup therapy, were studied. Twenty female subjects were treated with chincups and an orthopedic force of 500 g for 31 months (short-term treatment group). Another 36 female patients were treated with chincups and a force of 250 to 300 g for 86 months (long-term treatment group). All subjects treated with chincups had lateral cephalograms taken before treatment (T0), after treatment (T1), and at retention (T2). Cross-sectional lateral films of 562 skeletal Class III girls were selected from the records of 1265 Class III patients at a public hospital and private clinics as controls. The controls were selected to approximately match the ANB angle, Wits appraisal, and chronological age of the treated groups. Short-term treatment resulted in a slight improvement in ANB angle and Wits appraisal, while long-term treatment resulted in a significant improvement in ANB angle and Wits appraisal. Such treatment also resulted in a significant inhibition of the growth of the ramus (2.2 mm) and body length (3.6 mm) of the mandible, a backward rotation of the mandible, and a reduction (8.2 degrees ) of the gonial angle. However, there was no alteration of any parameter of the maxilla and the cranial base, except the length of S-N and N-S-Ar in the long-term treatment group. Subjects who completed the long-term treatment protocol retained the changes by wearing the appliance during sleep, with a force of 200 g applied to the center of the chin.

Case-Control Studies↗
PubMed2003

A biomechanical comparison of facet screw fixation and pedicle screw fixation: effects of short-term and long-term repetitive cycling.

STUDY DESIGN: A biomechanical study was conducted to assess the stabilization performance of transfacet pedicle screw fixation. OBJECTIVE: To compare the biomechanical effects of short-term and long-term cyclic loading on lumbar motion segments instrumented with either a pedicle screw or a transfacet pedicle screw construct. SUMMARY OF BACKGROUND DATA: Facet screw fixation is an alternative to pedicle screw fixation that permits the use of a minimally invasive strategy. It is not known whether facet screw fixation can provide stability equivalent to pedicle screw fixation during cyclical loading. Therefore, transfacet pedicle screw fixation and standard pedicle screw fixation techniques were compared biomechanically. METHODS: Lumbar motion segments were tested under short-term and long-term cyclic loading conditions. For the short-term phase, specimens were tested intact for six cycles (to 400 N or 4 Nm) in compression, flexion, extension, lateral bending, and torsion. The specimens then were instrumented with bilateral semicircular interbody spacers and pedicle screw instrumentation or transfacet pedicle screws, and the testing sequence was repeated. For the long-term phase, 12 specimens were instrumented in a similar manner and loaded to 6 Nm of flexion bending for 180,000 cycles. RESULTS: For the short-term phase, both fixation systems had significantly greater stiffness and reduced range of motion, as compared with the intact state. No differences were observed between the fixation systems except in flexion, wherein transfacet pedicle screw specimens were significantly stiffer than traditional pedicle screw specimens. For the long-term phase, the stiffness and range of motion did not significantly increase or decrease over repetitive cycling of the instrumented specimens. Furthermore, no significant difference between the fixation systems was observed. CONCLUSIONS: The stability provided by both transfacet pedicle screw fixation and traditional pedicle screw fixation was not compromised after repetitive cycling. In this model, transfacet pedicle screw fixation appears equivalent biomechanically to traditional pedicle screw fixation.

Biocompatible Materials↗
PubMedDate not supplied

Short-term and long-term variability of standard deviation scores for size in children.

PRIMARY OBJECTIVE: To quantify long-term and short-term variability in the standard deviation scores (SDS's) for six skeletal size variables and body mass index (BMI) in children and to compare average values of these quantities for boys with those of girls and to make comparisons across variables. METHODS AND PROCEDURES: The analysis is based on measurements made regularly for 120 boys and 112 girls from 1 month until 20 years for seven variables (standing height, sitting height, leg height, arm length, biiliac width, bihumeral width and BMI) as part of the first Zurich longitudinal growth study. Variation in these scores due to variablity in the timing of the pubertal spurt (PS) is separated out by rescaling the age axis on an individual basis and comparing children with the same developmental age rather than the same chronological age. For a given child, the relationship between the value of its SDS and age is modelled as the sum of an arbitrary (child dependent) smooth function plus an error term. The long-term variability for that child is defined to be the mean square of the departures of this smooth function from its mean level while the short-term variability is defined to be the variance of the error term. MAIN OUTCOMES AND RESULTS: Girls' SDS scores have significantly more long-term variability than those of boys, while there is no significant difference between the sexes for short-term variability. Bihumeral width, BMI and sitting height have significantly more long-term variation than the other variables. Bihumeral width and BMI have the largest short-term variability and standing height has the smallest. Correlations between long-term variability and adult size and timing and intensity of the PS were small. CONCLUSIONS: A useful way of assessing long-term and short-term variability of SDS's, which is widely applicable has been described and applied to data relating to the growth of children. The results of this analysis are intriguing. Why is the underlying growth process of girls more variable than that of boys? Differences across skeletal parameters are also interesting and deserve further consideration.

Body Height↗
PubMed1995

Comparison between short-term and long-term post-operative evaluation of sleep apnoea after uvulopalatopharyngoplasty.

For a long time uvulopalatopharyngoplasty (UPPP) has been used to treat the obstructive sleep apnoea syndrome (OSAS). The diverse surgical effects, the inadequate understanding of operation effect consistency, the possibility of disease progression, and the few reported papers for long-term evaluation after UPPP aroused our interest in designing this study. Fifteen OSAS patients who had undergone UPPP with pre-operative, initial post-operative and long-term post-operative polysomnographic studies were included in this study. Long-term post-operative polysomnography was undertaken more than five years after surgery. The polysomnographic evaluations included respiratory disturbance index (RDI), duration of saturation SaO2 < 85 per cent (DOS), and the lowest O2 saturation (LOS). Amongst them, 10 patients with initial post-operative RDI reduction > 50 per cent were considered responders. In these responders, the long-term follow-up results of all three parameters showed improvement compared to the pre-operative data. In a comparison between the initial and long-term post-operative sleep study results, LOS and DOS showed no significant difference. However, the long-term post-operative RDI result became significantly worse. More than 80 per cent of all cases had subjective symptomatic improvement in the long-term post-operative evaluation. The subjective improvement after operation is not adequately correlated to the polysomnographic result. We suggest that long-term follow-up for patients after UPPP is necessary.

Adult↗
PubMed1975

Short-term versus long-term hospitalization in a private psychiatric facility: a follow-up study.

A follow-up study was made of 43 short-term and 42 long-term ex-patients 18 months after their discharge from a private psychiatric hospital. The short-term sample was different from the long-term sample on many preadmission and hospitalization variables, but it was much less different on the follow-up variables. Although most ex-patients in both samples were functioning well at follow-up, the long-term sample was doing somewhat better in all areas, according to both the former patients and their nearest relatives. Differences between the improvement of those in the short- and long-term sample increased when tested by diagnosis; long-term schizophrenic patients improved the most.

Adult↗
PubMed2003

Genioglossus advancement and hyoid myotomy: short-term and long-term results.

Successful results of genioglossus advancement and hyoid myotomy with suspension (GAHM) in the treatment of obstructive sleep apnoea (OSA) have been reported. However, there have been few studies of long-term results. Forty-six patients with hypopharyngeal obstruction underwent GAHM. Patients had a mean age of 40.1 +/- 4.2 years and a mean body mass index (BMI) of 28.9 +/- 2.1 kg/m(2). The mean follow-up was 39.4 +/- 5.7 months with a range of 37 to 46 months. The mean pre-operative RDI, short-term RDI, and long-term RDI were 47.9 +/- 8.4, 14.2 +/- 3.9, 18.6 +/- 4.1, respectively. The mean post-operative LSAT, short-term LSAT, and long-term LSAT were 81.2 per cent +/- 2.9 per cent, 88.8 per cent +/- 2.7 per cent and 87.2 per cent +/- 3.1 per cent, respectively. The change in BMI was significantly different in the patients with, and without, recurrence (2.1 +/- 0.3 vs 0.4 +/- 0.2.kg/m(2), <0.05). Thirty (65.2 per cent) patients had long-term clinical success, and six (16.7 per cent) patients with short-term success failed long-term. GAHM appears to be an effective procedure and results in long-term success. However, patients with weight gain are at risk of recurrence.

Adult↗
PubMed1999

Prevention of influenza in long-term-care facilities. Long-Term-Care Committee of the Society for Healthcare Epidemiology of America.

Influenza is a frequent cause of epidemic and endemic respiratory illness in long-term-care facilities (LTCFs), resulting in considerable morbidity and mortality. Detection of influenza outbreaks in this setting can be difficult, because the clinical presentation in older adults is atypical and other pathogens also cause influenza-like illness (ILI) during the influenza season. Use of the standard case definition for influenza has not been effective in detecting episodes in residents of LTCFs. Alternative case-definitions that reflect the atypical presentation of influenza in this population have been recommended but not validated. The use of rapid tests for the detection of influenza in conjunction with more sensitive case definitions of ILI may lead to the earlier detection of influenza outbreaks in LTCFs, earlier initiation of infection control measures, and reduction in transmission. The definition of outbreak, eg, the number of episodes of ILI or episodes of confirmed influenza A that would result in the initiation of antiviral chemoprophylaxis, remains controversial in this setting. The use of newer antivirals could limit the side effects seen in older adults in LTCFs. However, annual vaccination of residents and staff remains the most effective way to prevent the introduction of influenza A or influenza B into LTCFs. In addition, vaccination of LTCF residents reduces rates of illness and pneumonia due to influenza, as well as cardiopulmonary exacerbation, hospitalization, and death.

Aged↗
PubMed2006

High-frequency conditioning electrical stimulation evokes supraspinal independent long-term depression but not long-term potentiation of the spinal withdrawal reflex in rats.

The aim of the current study was to investigate the effects on the spinal withdrawal reflex of electrical stimulation that has been shown to induce long-term potentiation (LTP) in spinal sensory systems. This was done in order to enhance our understanding of long-term dynamic modifications of spinal motor system during the exposure to high-frequency conditioning electrical stimulation (cES). The spinal withdrawal reflex was assessed by extracellular recording of the single motor unit (SMU) electromyographic (EMG) activity from the medial gastrocnemius (MG) muscle in intact and acutely spinalized rats. High-frequency (1 ms pulses at 100 Hz for 2 s repeated three times at 10 s intervals) tetanic cES produced a significant long-term depression (LTD) (at least 3 h), but not LTP, of the electrically evoked SMU EMG activity as well as the wind-up phenomenon (temporal summation). There were no significant depressive or facilitatory effects of low-frequency (2 Hz) cES, consisting of the same number of pulses as the 100 Hz cES, on the SMU EMG responses. This frequency-dependent long-term depressive effect on the spinal withdrawal reflex was not significantly changed following acute spinalization, indicating that LTD of the spinal motor system elicited by high-frequency cES is independent of the descending control system. We conclude that, in contrast to LTP in spinal sensory systems to brief tetanic C-fiber cES, high-frequency cES seems only to elicit LTD of motor systems of the spinal cord.

Action Potentials↗
PubMed2003

Cardiac surgery in patients receiving long term hemodialysis. Short and long term results.

AIM: Cardiac surgery carries a high risk in hemodialysis patients and has been questioned for its results; the purpose of this study is to focus on the short and long term results in our institution. METHODS: We retrospectively analyzed the data from 124 hemodialysis patients who underwent cardiac surgery in our unit between January 1980 and December 1998; 14.5% were diabetic; 46% had isolated coronary artery disease (group 1); 29.8% had valvular disease alone (group 2); 14.5% valve and coronary disease (group 3) and 9.6% miscellaneous disease at highest risk (group 4). We analyzed the relationship between several variables (age, sex, hypertension, diabetes, previous myocardial infarction, type of disease, preoperative ejection fraction) and operative mortality (30 days) and late survival. RESULTS: The overall operative mortality was 16.9%. The only risk factor was the type of cardiac disease: operative mortality was higher in groups 3 and 4 combined than in groups 1 and 2 combined (30% versus 12.7%, p=0.07). Ninety-nine patients were followed until January 2002. Late survival rate was 46.6+/-5% at 6 years for all patients, it was significantly better in groups 1 and 2 combined than in groups 3 and 4 combined. The only risk factor for late mortality was arterial hypertension. Fifty-seven patients are still alive, 46 in groups 1 and 2, 11 in groups 3 and 4. Progression of coronary lesions occurred in 6 patients and valvular lesions in 3 patients. The remainder are doing well. CONCLUSION: Cardiac surgery seems to be justified by the severity of the lesions. Its actual results can perhaps, be improved by earlier detection of cardiac disease and better prevention of myocardial hypertrophy and cardiac calcifications.

Age Factors↗
PubMed1991

The effectiveness of short-term versus long-term exposures to Photofrin II in killing light-activated tumor cells.

Asynchronous populations of mouse EMT-6 tumor cells were exposed to various doses of 630-nm light in slowly stirred aerobic suspensions after both short-term and long-term exposures to Photofrin II. All survival curves are characterized by a "threshold" light dose below which no cell inactivation occurs followed by a steep light-dose response. Both the shoulder widths and the inactivation curve slopes are functions of Photofrin II concentration. After high doses of light where survival levels are 0.003 and lower, "resistant tails" are observed on some survival curves. Light doses required to inactivate 50% of tumor cell populations were obtained from whole survival curves and their reciprocals (1/D50% survival) used as inactivation "rates". The amount of Photofrin II within cells was measured by a fluorescence assay. Per unit of fluorescence, this photosensitizer is at least 10 times more effective after long-term than after short-term exposures. After long-term exposures, both fluorescence activity and photosensitizing effectiveness are retained in washed cells for several hours. After short-term exposures, a majority of both the fluorescence and photosensitizing activity is lost by multiple washings or stirring in tissue culture medium without drug. These data suggest that the cellular compartments associated with photosensitization after short-term exposures to Photofrin II are probably different from the cellular compartments associated with photosensitization after long-term exposures to the drug. The data are consistent with known properties of the monomeric and oligomeric components of Photofrin II.

Animals↗
PubMed2006

Changes of basic bone turnover parameters in short-term and long-term patients with spinal cord injury.

The bone mineral density (BMD), the cross- links (PYD, DPD and NTx) and the bone specific alcaline phosphatase (BAP) was investigated in a cross-sectional study in 62 male patients with spinal cord injury (SCI), n = 28 short-term (0-1 year after SCI) and n = 34 long-term SCI patients (> 5 years after SCI). Knowledge about this parameters are necessary to find an adequate therapy for this special kind of osteoporosis. Immobilisation osteoporosis in SCI patients is a well-known problem that may lead to pathological fractures. Little is known regarding the extend of the osteoporosis as well as the causative factors. Measurements of the BMD in the proximal femur and the lumbar spine were performed with dual-energy-X-ray-absorptiometry (DEXA), of the osteoblast marker BAP (bone specific alkaline phosphatase) from serum and the osteoclast markers PYD (pyridinoline), DPD (desoxy-pyridinoline) and NTx (N-telopeptide of collagen type I) from urine. We found a significant decrease of BMD in the proximal femur and no relevant change in the lumbar spine compared to an age- and sex correlated control group (Z-score) in short-term and long-term SCI patients. There was a significant bone loss at the proximal femur between short and long-term SCI patients, whereas at the lumbar spine the BMD even slightly increases. Bone resorption (cross-links) was increased in both groups, though in long-term SCI patients it is significantly decreased compared to short-term SCI patients (DPD from 211.7 micro/g creatinine to 118.1 micro/g creatinine; NTx from 215.1 nmol/mmol creatinine to 83,6 nmol/mmol creatinine). The bone formation marker BAP is slightly below normal range in both groups (12.3 U/l in short-term, 9.7 U/l in long- term SCI patients). Only the proximal femur is affected by the immobilisation osteoporosis of SCI patients, therefore the BMD measurements in these patients should be performed at the lower limb. The problem of the immobilisation osteoporosis in SCI patients is the striking increase of bone resorption and the missing reaction of the bone formation.

Absorptiometry, Photon↗
PubMed2006

Short-term and long-term effects of violent media on aggression in children and adults.

OBJECTIVES: To test whether the results of the accumulated studies on media violence and aggressive behavior are consistent with the theories that have evolved to explain the effects. We tested for the existence of both short-term and long-term effects for aggressive behavior. We also tested the theory-driven hypothesis that short-term effects should be greater for adults and long-term effects should be greater for children. DESIGN: Meta-analysis. PARTICIPANTS: Children younger than 18 years and adults. MAIN EXPOSURES: Violent media, including TV, movies, video games, music, and comic books. MAIN OUTCOME MEASURES: Measures of aggressive behavior, aggressive thoughts, angry feelings, physiological arousal (eg, heart rate, blood pressure), and helping behavior. RESULTS: Effect size estimates were combined using meta-analytic procedures. As expected, the short-term effects of violent media were greater for adults than for children whereas the long-term effects were greater for children than for adults. The results also showed that there were overall modest but significant effect sizes for exposure to media violence on aggressive behaviors, aggressive thoughts, angry feelings, arousal levels, and helping behavior. CONCLUSIONS: The results are consistent with the theory that short-term effects are mostly due to the priming of existing well-encoded scripts, schemas, or beliefs, which adults have had more time to encode. In contrast, long-term effects require the learning (encoding) of scripts, schemas, or beliefs. Children can encode new scripts, schemas, and beliefs via observational learning with less interference and effort than adults.

Adult↗
PubMed1997

Infection prevention and control in the long-term-care facility. SHEA Long-Term-Care Committee and APIC Guidelines Committee.

More than 1.5 million residents reside in US nursing homes. In recent years, the acuity of illness of nursing home residents has increased. Long-term-care facility residents have a risk of developing nosocomial infection that is similar to acute-care hospital patients. A great deal of information has been published concerning infections in the long-term-care facility, and infection control programs are nearly universal. This position paper reviews the literature on infections and infection control program in the long-term-care facility, covering such topics as tuberculosis, bloodborne pathogens, epidemics, isolation systems, immunization, and antibiotic-resistant bacteria. Recommendations are developed for long-term-care infection control programs based on interpretation of currently available evidence. The recommendations cover the structure and function of the infection control program, including surveillance, isolation, outbreak control, resident care, and employee health. Infection control resources also are presented.

Cross Infection↗