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PubMedDate not supplied

Benign tracheobronchial stenoses: changes in short-term and long-term pulmonary function testing after expandable metallic stent placement.

PURPOSE: To determine the short- and long-term improvement in airflow dynamics in patients undergoing tracheobronchial stent placement for benign airway stenoses. METHODS: Twenty-two patients underwent 34 tracheal and/or bronchial stent placement procedures for benign airway stenoses and had the results of pulmonary function tests available. Stent placement indications included bronchomalacia after lung transplantation (n = 11), postintubation stenoses (n = 6), relapsing polychondritis (n = 2), and 1 each of tracheomalacia, tracheal compression, and histoplasmosis. Six patients underwent more than one stent placement procedure (range: 2-7 procedures). The mean forced expiratory volume in one second (FEV(1) ), forced expiratory flow rate in the midportion of the forced vital capacity curve (FEF(25-75) ), forced vital capacity, and peak flow (PF) rate obtained before stent placement were compared with those immediately after stent placement and with those measurements most remote from stent placement using the paired two-tailed test. RESULTS: All patients reported improved respiratory function immediately after stent placement. The mean FEV(1), FEF(25-75), and PF rate improved significantly (p < 0.001, p = 0.002, and p = 0.009, respectively) after stent placement. On long-term follow-up averaging 15 months after stent placement, these parameters declined despite patients' subjective sense of improvement. Segregating the population into transplant and nontransplant airway stenosis etiologies, however, FEF(25-75) and PF rate remained significantly improved (p = 0.045, p = 0.027, respectively), over the long term for the latter. FEV increased after subsequent stent placements for patients receiving multiple stents. CONCLUSION: Stent placement for benign tracheobronchial stenoses provides significant immediate improvement in airflow dynamics. Long-term improvement in airflow obstruction may be expected, and additional stent placements may further improve pulmonary function.

Adult↗
PubMed2006

Short-term and long-term FK506 treatment alters the vascular reactivity of renal and mesenteric vascular beds.

The aims of this study were to investigate the role of endothelin-1 in FK506-induced hypertension and vascular dysfunction of rats treated with the drug for 8 (short-term) or 30 (long-term) days and to measure malondialdehyde levels in the kidneys. Kidney and mesentery of rats were perfused. In the short-term treated groups, there was no significant change in systolic blood pressure. The response to noradrenaline only in renal vascular beds was significantly increased by FK506 and this increase was prevented by Bosentan. FK506 had no significant effect on sodium nitroprusside-induced vasodilation in comparison with solvent in both vascular beds. Bosentan failed to prevent these responses. In the long-term treated groups, at the end of the treatment with FK506, there was a significant increase in blood pressure, but no change in the response to noradrenaline in either kidneys or mesentery. The increase in blood pressure was prevented by bosentan treatment. FK506 increased malondialdehyde levels in the kidneys of the rats from only the long-term treated groups. Bosentan did not change this increase. Our results indicated that endothelin-1 plays a key role in the FK506-induced change in vascular reactivity to noradrenaline in renal vascular beds and drug-induced hypertension in the rats. There was no relationship between oxidative stress and FK506-induced hypertension.

Animals↗
PubMed2005

The German view: effects of nitrogen dioxide on human health--derivation of health-related short-term and long-term values.

The presented overview concerning health relevant effects caused by nitrogen dioxide (NO2) resumes the current state of results from animal experiments and human studies (epidemiology and short-term chambers studies). NO2 concentrations applied in animal experiments were mostly considerably higher than in ambient air. Therefore, short- and long-term limit values were derived from human data. Experimental studies conducted with humans demonstrate effects after short-term exposure to concentrations at or above 400 microg NO2/m3. Effects on patients with light asthma could not be observed after short-term exposure to concentrations below 200 microg/m3. On basis of epidemiological long-term studies a threshold below which no effect on human health is expected could not be specified. Two short-term limit values have been proposed to protect public health: a 1-h value of 100 microg/m3 and a 24-h mean value of 50 microg/m3. Due to the limitations of epidemiological studies to disentangle effects of single pollutants, a long-term limit value cannot be easily derived. However, applying the precautionary principle, it is desirable to adopt an annual mean of 20 microg NO2/m3 as a long-term mean standard to protect public health.

Air Pollutants↗
PubMed1998

Short-term and long-term fracture prediction by bone mass measurements: a prospective study.

Prospective and cross-sectional studies have demonstrated that bone mass predicts fracture risk. However, most prospective studies have been limited to a few years of follow-up. We investigated the long-term associations of bone mass with vertebral fractures using longitudinal data collected from more than 500 postmenopausal Japanese-American women in the Hawaii Osteoporosis Study. New vertebral fractures were identified during an average of 2.7 years between 1992 and 1995. Short-term fracture prediction was evaluated using bone mass (spine, calcaneus, distal radius, and proximal radius) measured at the beginning of follow-up. Long-term prediction was evaluated using bone mass measured before the follow-up period (11 years earlier for nonspine bone mass and 8 years earlier for spine). All four bone mass measurements were significant predictors of vertebral fractures identified during the subsequent 2.7 years (short-term prediction), with odds ratios (ORs) ranging from 1.5 to 1.9. The ORs for long-term prediction were slightly lower in magnitude, but the confidence intervals overlapped the short-term ORs considerably, suggesting that both long-term and short-term associations are similar in magnitude. Furthermore, cross-sectional analyses based on bone mass measurements performed at the end of follow-up (after fractures had occurred) yielded results similar to those based on prospective data (bone mass measured prior to fractures), suggesting that the relatively quick and inexpensive cross-sectional studies are useful for preliminary evaluations of new bone mass measurement techniques. The results suggest that bone mass measurements made up to 11 years earlier can predict vertebral fractures almost as well as measurements made more recently.

Asian↗
PubMed2006

Intermediate-term and long-term results after treatment by cidofovir and excision in juvenile laryngeal papillomatosis.

OBJECTIVES: We assessed the intermediate-term and long-term efficacy of intralesional injection of cidofovir used with surgical excision in juvenile-onset recurrent respiratory papillomatosis. METHODS: The protocol was revised during the study, from endoscopy at 4-week intervals with intralesional injection of cidofovir at 5 mg/mL, to a 2-week interval and a 7.5-mg/mL dosage. Partial surgical excision of hypertrophic papillomas was performed before the initiation of injection. Further injections at 4-week (or 2-week) intervals were performed until complete remission. RESULTS: Sixteen patients received a mean 8.9 injections. Complete remission was obtained in 12 patients (75%) after a mean 7.2 endoscopic treatments. Remission was stable at a mean 33.6 months' follow-up. Five of these 12 patients received 5.2 injections and remained disease-free at a mean 39.3 months' follow-up. Seven of the 12 had 1 relapse; they needed complementary treatment to become disease-free, and remained so thereafter over a mean 27.3 months' follow-up. The other 4 of the 16 patients (25%) continued to present active disease. CONCLUSIONS: Active endoscopic treatment until complete remission led to a higher-than-expected complete remission rate on intermediate-term to long-term follow-up, with or without relapse. Transient relapse was associated with a long delay in initiating cidofovir treatment.

Adolescent↗
PubMed1989

Changes in the basal metabolic rate of a normal woman induced by short-term and long-term alterations of energy intake.

A long-term experiment was carried out to study the effects of alterations in energy intake and meal contents on basal metabolic rate (BMR) of a normal woman. Alterations of energy intake induced changes in BMR and pulse rate in addition to body weight changes. Whether BMR was expressed per whole body, per unit body weight, or per unit body surface area, it increased progressively during long-term overeating periods, and decreased markedly during long-term undereating periods. These results suggest that there exists 'Luxuskonsumption', or adaptive diet-induced thermogenesis, during an overeating period and hypometabolism during an undereating period. BMR was affected significantly by the menstrual cycle but not by nutrient composition when daily energy intake was fixed at 2000 kcal for a long time.

Adult↗
PubMed2005

Differential patterns of extracellular signal-regulated kinase-1 and -2 phosphorylation in rat limbic brain regions after short-term and long-term inhibitory avoidance learning.

Activation of the extracellular signal-regulated kinase-1 and -2 has been shown to be required for neural plasticity and memory. Previous pharmacological studies have demonstrated that inhibition of extracellular signal-regulated kinase-1 and -2 blocks inhibitory avoidance retention. The aim of the present study was to investigate the different neural substrates underlying short- and long-term inhibitory avoidance learning and memory in rats using phosphorylated extracellular signal-regulated kinase-1 and -2 labeling as an index of plasticity. Short- and long-term retention tests were given 10 min or 24 h after inhibitory avoidance training. A significant elevation in the number of phosphorylated extracellular signal-regulated kinase-1 and -2-immunoreactive neurons was observed in area 1 of anterior cingulate cortex, the secondary motor cortex, lateral orbital cortex, claustrum, and the medial amygdala nucleus after the short-term inhibitory avoidance test. After the long-term retention test, phosphorylated extracellular signal-regulated kinase-1 and -2-immunoreactive neurons were localized in area 1 of anterior cingulate cortex, prelimbic cortex, and the central nucleus of amygdala. This suggests that phosphorylated extracellular signal-regulated kinase-1 and -2-immunoreactivity may reveal different brain regions involved in the storage of short- and long-term aversive memories.

Animals↗
PubMedDate not supplied

Asymmetric relationships between homosynaptic long-term potentiation and heterosynaptic long-term depression.

All synaptically-based neuropsychological theories of learning postulate that there are changes resulting from neural activity which are long-lasting and confined to specific sets of synapses. In the past decade a form of synaptic strengthening known as long-term potentiation (LTP) has been found which results from high-frequency neural activity and is of sufficient duration to model as a learning mechanism. Some early tests of the synaptic specificity of LTP in area CA1 of the hippocampus indicated that although LTP was specific to the tetanized pathway, in a converging untetanized pathway it was associated with depression of synaptic transmission lasting for at least 30 min. However, others have found that this heterosynaptic depression more usually decays within 5-15 min post-tetanus despite the maintenance of LTP in the tetanized pathway. Similarly, in the dentate gyrus (DG), LTP of either the lateral (LPP) or medial (MPP) components of the perforant path afferents has been associated with only short-lasting reciprocal heterosynaptic depression. Here, using more detailed measurement of stimulus intensity curves, we report that tetanization of either MPP or LPP reliably depresses synaptic transmission in the other pathway for at least 3 h. This heterosynaptic depression, considerably smaller than the usual magnitude of LTP, was obtained regardless of whether LTP had been produced in the tetanized homosynaptic pathway. Heterosynaptic long-term depression was not observed if the test pathway had been previously tetanized.

Animals↗
PubMed1994

Short-term or long-term intracerebroventricular (i.c.v.) infusion of insulin exhibits a discrete anabolic effect on cerebral energy metabolism in the rat.

Evidence for an involvement of insulin in the regulation of cerebral glycolytic glucose catabolism is becoming more and more convincing. To investigate whether short-term or long-term administration of insulin to the brain influences brain energy metabolism, we determined tissue concentrations of energy-rich phosphates in cerebral parietotemporal cortex and in hippocampus of 1- (adult) and 2-year-old (aged) male Wistar rats treated with intracerebroventricular (i.c.v.) infusion of the hormone for 1, 7, and 21 days. In cerebral parietotemporal cortex, tissue concentrations of ATP, PCr, ADP, ATP/ADP ratio and energy charge potential were all unaltered. In hippocampus, however, the concentration of PCr was significantly increased. Thus, short-term and long-term i.c.v. administration of insulin are assumed to have a discrete anabolic effect on the cerebral energy pool.

Adenosine Diphosphate↗
PubMed1998

Systemic administration of atipamezole, a selective antagonist of alpha-2 adrenoceptors, facilitates behavioural activity but does not influence short-term or long-term memory in trimethyltin-intoxicated and control rats.

The present study used trimethyltin (TMT)-intoxicated rats as a model for the behavioural syndrome seen after neuronal damage to the limbic system. Behavioural assessments indicated increased locomotor activity and reduced number of groomings in an open-arena task in TMT-intoxicated (6.6 mg/kg as a free base) rats, as has been found previously. A novel finding was the severe deficit in swimming to a visible platform in the water maze task, with reduced swimming speed at the beginning of the training period. During the reacquisition phase of a radial arm maze task, TMT-intoxicated rats made more short-term and long-term memory errors, and their behavioural activity was increased in comparison with controls. The administration of atipamezole (300 micrograms/kg), a selective antagonist of alpha 2-adrenoceptors, enhanced locomotor activity compared to saline-treated rats, but these effects did not differ between the TMT group and their controls. Atipamezole did not enhance short-term or long-term memory in either TMT or control groups. Taken together, the present data indicate that TMT intoxication is a model for global dementia rather than for a specific loss of relational memory. Previous studies on the neurochemical effects of TMT and the alleviation or prevention of neurotoxicity of TMT are reviewed.

Adrenergic alpha-2 Receptor Antagonists↗
PubMed1997

Endoscopic sphincterotomy for choledocholithiasis: a prospective single-center study on the short-term and long-term treatment results in 483 patients.

BACKGROUND AND STUDY AIMS: Endoscopic sphincterotomy (EST) is the method of choice for the treatment of choledocholithiasis. The aim of the present study was to assess the impact of various prognostic factors on the short-term and long-term results of EST. PATIENTS AND METHODS: Data from 483 EST procedures carried out due to choledocholithiasis without concomitant neoplasms or hepatic cirrhosis, and without subsequent bile duct surgery, were analyzed prospectively. The 324 patients (67%) who agreed to take part in the follow-up examinations and fulfilled the inclusion criteria for the study were divided into four groups, depending on the presence of the gallbladder or cholecystolithiasis prior to EST and on the time of diagnosis, and were prospectively followed up by physical examination laboratory tests, abdominal ultrasound, and endoscopic retrograde cholangiography examinations to evaluate the short-term and long-term outcomes. RESULTS: EST was successful in 95.7% of cases. Early complications were noted in 6.8% of cases. No early complications were seen in the group after cholecystectomy with a T-tube present, whereas this rate was highest in the group with concurrent choledocholithiasis and cholecystolithiasis (six of 48, 12.5%). Recurrent choledocholithiasis was observed in 5.6% of the cases overall. This rate was at its lowest in patients with choledocholithiasis alone, and was highest in the group with concurrent choledocholithiasis and cholecystolithiasis. Among the latter patients, the highest rates of papillary stenosis, chronic pancreatitis, and cholangitis were also observed, the latter complication being noted only in cases of recurrent common bile duct stones. CONCLUSIONS: EST is a relatively safe and effective procedure in the treatment of choledocholithiasis. The best prognostic factor is the presence of choledocholithiasis alone. Concurrent choledocholithiasis and cholecystolithiasis carry a more adverse prognosis, and in these cases cholecystectomy should be considered after EST.

Abdominal Pain↗
PubMed1999

Clinical study of mitral valve repair: short-term and long-term outcomes.

BACKGROUND: In recent years, mitral valve reconstructive techniques have become an increasingly preferential alternative to replacement. The purpose of this study was to evaluate short-term and long-term outcomes associated with mitral valve repair. METHODS: This study involved 99 patients who had mitral valve repair for mitral regurgitation from January 1990 to June 1996. Short-term and long-term outcomes evaluated included mortality, clinical complications, readmissions, valve deterioration, reoperation, thromboembolism, endocarditis, functional heart class, and health perception. RESULTS: Overall mortality was 18%, which included 11 operative deaths and 7 late deaths. Ischemic valve disease and NYHA class III and IV were significant predictors of early and late mortality. Overall 5-year survival was 79%. Freedom from all valve-related morbid events was 90% at 5 years. CONCLUSIONS: Functional heart class and etiology of valve disease are the most important indicators of overall survival and morbidity. Transesophageal echocardiography should be used to evaluate the adequacy of repair.

Adult↗
PubMed1997

[The memorization of new material and the probable energy processes in the short-term and long-term memories of adolescents].

In age-related, occupational and individual aspects the dynamics of the transition of the visual technical information was investigated from short-term to long-term memory in growing up individuals, mastering the profession of operator-power engineer. The variants of probable distribution of the nervous energy between focus and background of the operative field of the brain were considered in the examined pupils. It was established that at the first presentation of complex technical information the occupationally adapted pupils in significant higher volume were able to assimilate the presented information than the occupationally unadapted ones. It was demonstrated that the process of transition of the visual information from conditions of short-term to long-term memory processed by stages in all examined individuals according to the assimilation or loss of part of the presented for memorizing information in every cycle of its repetition. It was assumed that each stage of memorizing which is connected with assimilation or loss of the information had its connected with assimilation or loss of the information had its strictly individual energetic characteristics. The complex variants of the energetic processes were considered. The results of the carried out investigations also revealed that assimilation of visual information depended to a greater extent of the individual abilities of the pupils rather than of their age.

Adolescent↗
PubMed1981

Short-term and long-term ethanol administration inhibits the placental uptake and transport of valine in rats.

Ethanol ingestion during pregnancy causes a pattern of fetal/neonatal dysfunction called the FAS. The effects of short- and long-term ethanol ingestion on the placental uptake and maternal-fetal transfer of valine were studied in rats. The in vivo placental uptake and fetal uptake were estimated after injection of 0.04 micromol of 14C-valine intravenously on day 20 of gestation in Sprague-Dawley rats. Short-term ethanol ingestion (4 gm/kg) caused a significant reduction in the placental uptake of 14C-valine by 33%, 60%, and 30%, and 31% at 2.5, 5, 10, and 15 min after valine administration, respectively (p less than 0.01), and a similar significant reduction occurred in the fetal uptake of 14C-valine (p less than 0.01). Long-term ethanol ingestion prior to and throughout gestation resulted in a 47% reduction in placental valine uptake (p less than 0.01) and a 46% reduction in fetal valine uptake (p less than 0.01). Long-term ethanol feeding from day 4 to day 20 of gestation caused a 32% reduction in placental valine uptake (p less than 0.01) and a 26% reduction in fetal valine uptake (p less than 0.01). We conclude that both short- and long-term ingestion of ethanol inhibit the placental uptake and maternal-fetal transfer of an essential amino acid--valine. An alteration of placental function may contribute to the pathogenesis of the FAS.

Animals↗
PubMed2006

Simultaneous NMDA-dependent long-term potentiation of EPSCs and long-term depression of IPSCs in cultured rat hippocampal neurons.

A fundamental issue in understanding activity-dependent long-term plasticity of neuronal networks is the interplay between excitatory and inhibitory synaptic drives in the network. Using dual whole-cell recordings in cultured hippocampal neurons, we examined synaptic changes occurring as a result of a transient activation of NMDA receptors in the network. This enhanced transient activation led to a long-lasting increase in synchrony of spontaneous activity of neurons in the network. Simultaneous long-term potentiation of excitatory synaptic strength and a pronounced long-term depression of inhibitory synaptic currents (LTDi) were produced, which were independent of changes in postsynaptic potential and Ca2+ concentrations. Surprisingly, miniature inhibitory synaptic currents were not changed by the conditioning, whereas both frequency and amplitudes of miniature EPSCs were enhanced. LTDi was mediated by activation of a presynaptic GABAB receptor, because it was blocked by saclofen and CGP55845 [(2S)-3-{[(15)-1-(3, 4-dichlorophenyl)ethyl]amino-2-hydroxypropyl)(phenylmethyl)phosphinic acid]. The cAMP antagonist Rp-adenosine 3 ', 5 ' -cyclic monophosphothioate abolished all measured effects of NMDA-dependent conditioning, whereas a nitric oxide synthase inhibitor was ineffective. Finally, network-induced plasticity was not occluded by a previous spike-timing-induced plasticity, indicating that the two types of plasticity may not share the same mechanism. These results demonstrate that network plasticity involves opposite affects on inhibitory and excitatory neurotransmission.

2-Amino-5-phosphonovalerate↗
PubMed1992

Short-term and long-term treatment with propafenone: determinants of arrhythmia suppression, persistence of efficacy, arrhythmogenesis, and side effects in patients with symptoms.

OBJECTIVE: To assess the clinical criteria predicting the short and long-term efficacy of propafenone, an agent with class IC antiarrhythmic activity and a broad pharmacological profile. DESIGNS: Prospective study of propafenone at doses of 450 to 900 mg/day during a six week dose titration period (including a placebo phase with two separate 24 Holter recordings). Responders to treatment were followed for one year. PATIENTS: One hundred patients with frequent ventricular arrhythmias (greater than 30 extrasystoles/h) of Lown class III and IVA/B and without evidence of myocardial infarction within the past six months. ANALYSIS: Multivariate regression analysis of spontaneous arrhythmia variability and of different clinical variables to determine the short and long-term efficacy and safety of propafenone. MEASUREMENTS AND MAIN RESULTS: Propafenone 450 mg/day was effective in 30/100 patients (30%), and at 600 mg/day another 14 responded. The efficacy of propafenone correlated with a low spontaneous arrhythmia variability and, as shown by multivariate analysis, with a lower patient age (p less than 0.05). When the dose was increased to 900 mg/day a further six (12%) patients responded. However, with increasing doses of propafenone, the one year probability of effective treatment decreased from 86% (450 mg/day) to 67% (600 mg/day) and to 44% (900 mg/day). After restudying the patients at three, six, and 12 months and after dose adjustment in 11/44 patients (25%), 31 patients (70%) remained responders. Loss of permanent antiarrhythmic efficacy was best predicted by the initial dose that achieved a response. No patient died suddenly or had arrhythmogenic effects during Holter monitoring. Side effects occurred in 36% of patients but these rarely limited long-term treatment. CONCLUSIONS: A younger age, low spontaneous arrhythmia variability, and particularly a low titration dose were the best predictors of the short and long term efficacy of propafenone. All other responders should have repeated Holter recordings during the first year of treatment.

Adult↗