PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Long term”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 271 records · Page 15Linked to original sources
PubMed1993

Effects of short-term and long-term androgen treatment on the diaphragm in male and female rats.

The effects of short-term (2.5 wk) and long-term (10 wk) testosterone propionate (2.5 mg/day; 5 days/wk) treatment on diaphragm contractility, fatigue resistance, and fiber type proportions were studied in male and female rats. Contractility and fatigue resistance indexes were measured in an in vitro diaphragm costal strip preparation by direct stimulation at 37 degrees C. The fatigue paradigm consisted of 30 trains/min at 5 Hz (50% duty cycle) for 10 min. Fatigue resistance indexes were calculated as postfatigue divided by baseline forces. In females but not males, testosterone treatment produced significant increases in body weight, costal diaphragm weight, and contractility and significant decreases in fatigue resistance indexes. The interaction between testosterone treatment and the duration of treatment was significant, with the increase in contractility (females) being significant after short-term but not long-term treatment. No significant difference in fiber type proportions or areas was observed, regardless of treatment duration or the preexperimental, basal circulating level of androgen.

Animals↗
PubMed2002

Prefrontal cortex long-term potentiation, but not long-term depression, is associated with the maintenance of extinction of learned fear in mice.

Considerable efforts have been made to identify changes of brain synaptic plasticity associated with fear conditioning. However, for both clinical applications and our fundamental understanding of memory processes, it appears also necessary to investigate synaptic plasticity related to extinction. We previously showed that extinction of freezing to a tone conditioned stimulus (CS; previously paired with footshock) in mice results in a sequence of depression and potentiation of synaptic efficacy in the medial prefrontal cortex (mPFC). These data as well as those from lesion studies suggest that the direction of changes in prefrontal synaptic plasticity may modulate extinction of learned fear. To test this, we analyzed the effects of low-frequency stimulation (LFS) and high-frequency stimulation (HFS) of the mediodorsal thalamic nucleus, known to induce prefrontal long-term depression (LTD) and potentiation (LTP), respectively, on extinction. We found that maintenance of the depression phase, using thalamic LFS, was associated with resistance to extinction. Thalamic HFS applied before extinction testing had no effect on the rate of extinction. However, 1 week follow-up tests revealed that the memory of extinction was intact in these mice (with prefrontal LTP) and in control mice displaying prefrontal LTP-like changes, whereas control mice that did not exhibit such changes displayed a return of freezing to the CS. The results suggest that after extinction the lack of depression-LTP-like conversion sequence in the mPFC synaptic efficacy may profoundly alter the process of consolidation.

Acoustic Stimulation↗
PubMed1996

Financing reform for long-term care: strategies for public and private long-term care insurance.

The way the nation provides for the financing and delivery of long-term care is badly in need of reform. The principal options for change are private insurance, altering Medicaid, and public long-term care insurance. This article uses the Brookings-ICF Long-Term Care Financing Model to evaluate each of these options in terms of affordability, distribution of benefits, and ability to reduce catastrophic out-of-pocket costs. So long as private insurance is aimed at the elderly, its market penetration and ability to finance long-term care will remain severely limited. Affordability is a major problem. Selling to younger persons could solve the affordability problem, but marketing is extremely difficult. Liberalizing Medicaid could help solve the problems of long-term care, but there is little public support for means-tested programs. Finally, universalistic public insurance programs do well in meeting the goals of long-term care reform, but all social insurance programs are expensive and seem politically infeasible in the current political environment.

Aged↗
PubMedDate not supplied

Two forms of hippocampal long-term depression, the counterpart of long-term potentiation.

In the hippocampus there are two distinct forms of long-term depression (LTD) of excitatory synaptic transmission. In the CA1 region, prolonged low-frequency stimulation induces LTD by activating postsynaptic NMDA receptors, which causes a moderate rise in Ca2+ concentrations. In mossy fiber synapses of the CA3 region, similar low-frequency stimulation also gives rise to LTD. However, this form of LTD (mossy fiber LTD) does not require activation of NMDA receptors, but is mediated by activation of presynaptic metabotropic glutamate receptors. Induction of mossy fiber LTD is not dependent on postsynaptic depolarization or activation of postsynaptic ionotropic glutamate receptors, thus it is likely to be mediated by purely presynaptic mechanisms. This conclusion is confirmed by the analysis of mutant mice lacking presynaptic mGluR2, in which mossy fiber LTD is almost absent. Since long-term potentiation at mossy fiber synapses is also induced presynaptically, the synaptic efficacy may be regulated through common mechanisms bidirectionally, which may contribute to neural information processing in the hippocampus.

Animals↗
PubMed2003

Short-term and long-term benefits of endoscopic hemoclip application for Dieulafoy's lesion in the upper GI tract.

BACKGROUND: Dieulafoy's lesion is an important cause of GI bleeding. The results of hemoclip application as the first treatment of choice for Dieulafoy's lesions have not been reported. This study prospectively examined the short- and long-term outcomes of hemoclip application for Dieulafoy's lesions. METHODS: The study was conducted over a 7-year period beginning in January 1995 during which hemoclip application was used as the first-choice hemostatic treatment for Dieulafoy's lesions. Clinical data, endoscopic findings, and outcome of treatment were evaluated. Long-term outcome for patients was also investigated. RESULTS: A Dieulafoy's lesion was diagnosed in 34 patients (27 men, 7 women; mean age, 54 years, range 21-81 years) after a mean of 1.2 endoscopies; 79.4% of the patients had active bleeding. Initial hemostasis was attained by hemoclip placement in 94.1%. The rate of recurrent bleeding was 9.3%. No patient required additional treatment such as surgery. The 30-day mortality rate was 2.9% (1 death, unrelated). For the remaining 33 patients, median follow-up was 53.8 months (range 19 to 90 months). Another Dieulafoy's lesion developed in one patient during follow-up, but in a different location compared with the index lesion. CONCLUSIONS: Endoscopic hemoclip application for Dieulafoy's lesions was effective and safe with short- and long-term benefits.

Aged↗
PubMed1996

Role of protein synthesis in the transition from synaptic short-term to long-term depression in neurons of Helix pomatia.

The time course of the formation of synaptic long-term depression was analysed in neurons of Helix pomatia. Polysynaptic excitatory postsynaptic potentials were evoked in identified neurons by stimulation of the right pallial nerve. First, synaptic depression was observed during four consecutive series of excitatory postsynaptic potentials spaced by either 2, 10 or 60 min in the presence and absence of compounds inhibiting protein synthesis. Inhibition of RNA translation (but not of transcription) reduced the increasing depression of series spaced by 10 and 60 min but not by 2 min. This demonstration of translation-dependent depression present only 10 min after a previous excitatory postsynaptic potential series was analysed further by observations of the time course of excitatory postsynaptic potential recovery from short-term depression in experiments with intact versus inhibited protein synthesis. When synthesis was inhibited, recovery occurred along a double-exponential trajectory. However, when synthesis was intact, the exponential recovery was interrupted discontinuously 6-10 min after a series of excitatory postsynaptic potentials by the onset of a spontaneous and increasing depression lasting for at least 12 h. Puromycin, anisomycin and actinomycin D were used as inhibitors not affecting the short-term properties of excitatory postsynaptic potentials. Experiments with camptothecin, on the other hand, revealed that this inhibitor enhanced excitatory postsynaptic potential amplitudes and reduced their short-term depression. It is concluded that long-term depression, depending upon de novo protein synthesis, was initiated only 10 min after a series of excitatory postsynaptic potentials. Evidence was obtained indicating that this early initiated protein synthesis circumvented the transcription processes within the cell nuclei.

Animals↗
PubMed2006

Clinical trials with rasagiline: evidence for short-term and long-term effects.

Rasagiline (N-propargyl-1 (R)-aminoindan) is a selective, potent irreversible inhibitor of MAO-B that possesses neuroprotective and anti-apoptotic properties in a variety of in vitro and in vivo animal models relevant to Parkinson's disease (PD). Several randomized controlled clinical trials have demonstrated the safety and efficacy of rasagiline as monotherapy in PD and as adjunctive therapy for patients receiving levodopa. In addition, the 1-year randomized, delayed-start analysis of the TEMPO study suggests that rasagiline may slow the rate of progression of PD. The randomized delayed-start paradigm has potential to differentiate short-term symptomatic effects from long-term effects of anti-parkinsonian agents. In the future, long-term trials to examine the potential disease-modifying effects of rasagiline, which incorporate biological markers as well as clinical endpoints, may further elucidate the role of rasagiline in the treatment of both early and advanced PD.

Evidence-Based Medicine↗
PubMed2000

Learning effect, short-term fluctuation, and long-term fluctuation in frequency doubling technique.

PURPOSE: To evaluate short-term and long-term fluctuations and learning effects in healthy subjects tested with the frequency doubling technique, which is based on a low spatial frequency and a high temporal frequency stimulus. METHODS: Twenty-three healthy adult subjects were consecutively recruited from volunteers, and 20 subjects finished the study. All the visual fields were assessed by the frequency doubling technique, program C-20, full threshold. The frequency doubling technique presents stimuli on a black-and-white video monitor with specialized control circuitry interfaced to a microprocessor. During program C-20, full threshold, 17 points are tested, one round point centrally and 16 square ones in the periphery up to 20 degrees of eccentricity. Each stimulus consists of a 0.25-cycle/degree sinusoidal grating undergoing a 25-Hz counterphase flicker. One eye of each patient was chosen at random. Each subject was tested once in the first session, three times in the second session, and once in the third and fourth sessions. Both short-term and long-term fluctuation were studied either as the average fluctuation value of all the points tested or as a point-to-point fluctuation. To study the learning effect, the results of the first session were compared with those of the second, the third, and the fourth sessions. RESULTS: The average mean sensitivity of the three examinations of the second session was 30.4 +/- 1.24 dB, and the average short-term fluctuation of all the subjects was 2.16 +/- 0.5 dB. The short-term fluctuation of each point tested ranged from 1.4 to 3.4 dB. The average mean sensitivity for all the sessions was 32.4 +/- 1.14 dB, with an average long-term fluctuation of 3.23 +/- 0.5 dB, and the long-term fluctuation of each tested point ranged from 2.5 to 4.4 dB. A mild learning effect was found between the first section and the others. CONCLUSION: Short-term and long-term fluctuations were similar to those known to occur with the conventional threshold perimetry when they were compared with the literature data. A learning effect was also observed and should be taken into account for the clinical use of this test.

Adult↗
PubMed2002

Correlation between short-term and long-term radon measurements.

In selected kindergartens and schools, long-term average indoor air radon concentrations were measured by two-month exposure of etched track detectors. Short-term average concentrations were obtained from 7-10 day continuous radon recordings during the exposure of etched track detectors. Only in about 1/3 of cases both averages did agree within +/- 20%; otherwise they differ considerably. The assumption that short-term results can substitute for long-term data, which is sometimes made to correct radon exposure estimated on the basis of concentrations obtained by etched track detectors, should therefore be treated with caution.

Air Pollution, Indoor↗
PubMed2005

Short-term, medium-term, long-term, and lifetime risks of developing and dying of breast carcinoma in a Westernized Chinese population: Evidence from Hong Kong between 1976 and 2000.

BACKGROUND: Estimates of lifetime and shorter-term risks of developing and dying of breast carcinoma are useful translational statistics for risk communication; however, these statistics are unknown for Chinese women, who account for one-fifth of the world's female population. In the current study, the authors examined age-specific 5-year, 10-year, 20-year, and lifetime risks of breast carcinoma incidence and disease-related mortality among Hong Kong women. METHODS: Multiple-decrement life tables were constructed by applying age-specific incidence and mortality rates obtained from cross-sectional data to a hypothetic birth cohort. Incidence, mortality, and population data from 1976 through 2000 were used. RESULTS: For Hong Kong women in the period 1996-2000, the overall lifetime risk of developing invasive breast carcinoma was 5.7% (1 in 17), compared with 10.6% (1 in 9) for U.S. Asian/Pacific Islander women and 14.5% (1 in 7) for U.S. white women. The lifetime breast carcinoma-related mortality risk for Hong Kong women in that same period was 1.7% (1 in 58). For women age 50 years, the 5-, 10-, and 20-year risks of developing breast carcinoma were 0.6% (1 in 172), 1.1% (1 in 87), and 2.1% (1 in 47), respectively. The absolute lifetime probability of developing breast carcinoma increased from 3.81% (1 in 26) during the period 1976-1980 to 5.73% (1 in 17) during the period 1996-2000; 44.5% of this change can be attributed to the increased longevity of women in the latter time period, and the remaining 55.5% can be ascribed to a secular rise in breast carcinoma incidence. CONCLUSIONS: As China becomes more Westernized, the authors expect that the risks of developing and dying of breast carcinoma for Chinese women will become more similar to the corresponding risks for Western women. The current data from Hong Kong, the most Westernized Chinese community, appear to support this conclusion.

Adult↗
PubMed2004

Comorbid cannabis use and panic disorder: short term and long term follow-up study.

OBJECTIVES: The aim of the study was to compare the treatment of panic disorder in patients with or without cannabis use according to response, relapse and side effects. MATERIALS AND METHODS: 66 panic disorder (PD) patients were included in our study. All the subjects met the DSM-IV diagnosis of panic disorder (n=45) or panic disorder with agoraphobia (n=21). Twenty four patients experienced their first panic attack within 48 h of cannabis use and then went on to develop PD. All the patients received pharmacologic treatment with paroxetine (gradually increased up to 40 mg/d). A masked rater that was blind to the group allocation, assessed patients in order to rate anxiety symptoms and medication side effects. Relapse was defined as the occurrence of a single panic attack after remission of panic symptoms. The instruments were administered at baseline and also at the 4, 8 and 12 weeks visits and at the 1 year visit. RESULTS: The two groups responded equally well to paroxetine treatment as measured at the 8 weeks and 12 months follow-up visits. There were no significant effects of age, sex and duration of illness as covariates with response rates between the two groups. Also PD or PDA diagnosis did not affect the treatment response in either group. There were no significant differences in weight gain, sexual side effects or relapse rates between patients according to gender or comorbid diagnosis. SUMMARY: Acute cannabis use can be associated with the onset of panic attacks and panic disorder, and panic disorder which develops after cannabis use is responsive to pharmacotherapy.

Adolescent↗
PubMed2002

[Dissection or irradiation of the axilla in postmenopausal patients with breast cancer? Long-term results and long-term effects in 655 patients].

BACKGROUND: Until 1993 postmenopausal women with breast cancer did not receive adjuvant chemotherapy in our institution even if axillary nodes were involved. So in these patients axillary dissection had no diagnostic value for further treatment. Therefore we started a prospective study in which dissection of axillary nodes was replaced by irradiation in postmenopausal cN0 patients. PATIENTS AND METHODS: From 1986 to 1993 we irradiated 655 patients with breast cancer after breast conserving surgery (BET). In all 144 cN1- and all 209 premenopausal cN0-patients axillary dissection was recommended. Of 302 postmenopausal cN0 patients 129 had breast surgery in our institution. In a total of 129 patients axillary dissection was replaced by irradiation (AxRT-group). They were compared with all 173 patients referred from other hospitals for irradiation after both breast conserving surgery and axillary dissection (AxOP-group). Dissected patients with gross tumor involvement of the axilla or less than eight nodes removed had additional axillary irradiation. Patients age, tumor size, vessel-, muscle- or skin invasion and grading were similar in both groups (Table 1). However, in the AxRT-group there were more patients with negative hormone receptors, multifocal and medial sited tumors. Late complications after dissection and/or irradiation of the axilla were evaluated in 502 patients free of locoregional relapse and with a minimal follow up of 3 years (median 9.5 years). RESULTS: After 5, 10 and 15 years tumor free survival rates were 90%, 82% and 79% in the AxOP-group vs 91%, 82% and 80% in the AxRT-group, respectively (p = 0.95) (Figure 1). Overall survival (p = 0.98) (Figure 2), local (p = 0.47) and axillary control (p = 0.12) were equal in both groups (Figures 3 and 4). However, serious problems like lymphedema of the arm, pain, mobility impairment occurred in 26% patients following axillary dissection but only in 1% after axillary irradiation. No difference in late sequelae after axillary dissection with or without irradiation could be detected (26 vs 27%) (Table 2). CONCLUSION: In postmenopausal cN0-patients axillary dissection should be replaced by axillary irradiation, since it offers the same chance for cure with much lower morbidity.

Aged↗
PubMed2006

A comparison between the short term and long term benefits of screening for abdominal aortic aneurysms from the Huntingdon Aneurysm screening programme.

BACKGROUND: The UK Multicentre Aneurysm Screening Study (MASS) showed a 44% reduction in AAA-related mortality after 4 years and predicted an increased number of deaths prevented in the longer term. We aim to compare the 5 and 13 years benefit from aneurysm screening in the Huntingdon Aneurysm screening programme. METHODS: Incidence and mortality of ruptured AAA (RAAA) after 5 and 13 years of screening in a population based aneurysm screening program. RESULTS: Five years of screening resulted in a reduction in the incidence of RAAA of 49% (95% CI: 3-74%). Nine out of 11 ruptures in the invited group did not survive (mortality 82%; 95% CI: 48-98%) compared to 38 non-survivors from 51 ruptures in the control group (mortality 75%; 95% CI: 60-86%). Five years of screening resulted in an RAAA-related mortality reduction of 45% (95% CI: -15 to 74%). After 13 years of screening the incidence of RAAA was reduced by 73% (95% CI: 58-82%). Twenty-one out of 29 ruptures in the invited group did not survive (mortality 72%; 95% CI: 53-87%) compared to 64 non-survivors from 82 ruptures in the control group (mortality 78%; 95% CI: 68-86%). Thirteen years screening resulted in a reduction of mortality from RAAA of 75% (95% CI: 58-84%). The number needed to screen to prevent one death reduced from 1380 after 5 years to 505 after 13 years. The number of elective AAA operations needed to prevent one death reduced from 6 after 5 years to 4 after 13 years. CONCLUSION: AAA screening becomes increasingly beneficial as screening continues over the longer term. Benefits continue to increase after screening has ceased.

Aortic Aneurysm, Abdominal↗
PubMed2002

Short term and long term effects of enhanced auditory feedback on typing force, EMG, and comfort while typing.

Two studies were conducted to determine the effects of enhanced auditory feedback on typing force, electromyography (EMG) and subjective discomfort. The introduction of enhanced auditory feedback caused a 10-20% reduction in 90th percentile typing force, finger flexor EMG, and finger extensor EMG. Adaptation to the enhanced auditory feedback occurred in <3 min. After 1 week of intermittent enhanced auditory feedback there were no differences in typing force or EMG while subjects were typing with or without the enhanced auditory feedback. The continued use of auditory feedback did not further reduce the levels of typing force or EMG after 1 or 2 weeks of exposure.

Adult↗