Novelty and anxiolytic drugs dissociate two components of hippocampal theta in behaving rats

Hippocampal processing is strongly implicated in both spatial cognition and anxiety and is temporally organized by the theta rhythm. However, there has been little attempt to understand how each type of processing relates to the other in behaving animals, despite their common substrate. In freely moving rats, there is a broadly linear relationship between hippocampal theta frequency and running speed over the normal range of speeds used during foraging. A recent model predicts that spatial-translation-related and arousal/anxiety-related mechanisms of hippocampal theta generation underlie dissociable aspects of the theta frequency–running speed relationship (the slope and intercept, respectively). Here we provide the first confirmatory evidence: environmental novelty decreases slope, whereas anxiolytic drugs reduce intercept. Variation in slope predicted changes in spatial representation by CA1 place cells and novelty-responsive behavior. Variation in intercept predicted anxiety-like behavior. Our findings isolate and doubly dissociate two components of theta generation that operate in parallel in behaving animals and link them to anxiolytic drug action, novelty, and the metric for self-motion

Improving anemia management with less frequently dosed erythropoiesis stimulating agents

Introduction and Aims: The process of delivering erythropoiesis stimulating agents (ESAs) to hemodialysis patients (HD) is complex. Many European countries are requiring centers to document this process. To date, there has not been any comprehensive description of the operational aspects of ESA delivery in Europe. The objective of the Mercurius study was to describe the entire process of ESA delivery in dialysis centers. In addition, we explored the benefits of less frequent dosing. Methods: A conceptual model was developed to classify the sub-processes in the pharmacy, dialysis unit, waste unit, and back office. Within each dialysis unit activities associated with dose determination, ordering procedures, receipt and storage of ESAs, and ESA administration were measured. Within the pharmacy, ordering from supplier, receiving and storing, and delivering ESA to the dialysis unit were measured. The amount of time and materials associated with waste disposal and back office activities were also observed. We also evaluated the impact of less frequent dosing on the resources required to perform anemia management for HD patients. Structured interviews with staff were used to develop a comprehensive list of processes, sub-processes, and activities that are routinely followed to order, register, administer, and dispose of waste associated with ESAs. Each activity was evaluated to determine if less frequent dosing influenced the amount of resources required. A model was developed to estimate the change in resources consumed using less frequent dosing regimens. Results: Eight centers from 5 European countries (Belgium, France, Italy, Sweden, and Switzerland) participated in the study. The number of HD patients in each center ranged from 42 to 707 (mean=175). Across all of the centers, patients received a variety of dosing regimens (eg, TIW, BIW, QW and Q2W). The mean (±SD) time spent for the pharmacy to order an ESA from the supplier was 6.1 (±8.7) minutes; time spent in the dialysis unit and pharmacy for receiving and storing ESPs was 5.3 (±5.3) and 10.0 (±10.9) minutes, respectively; and time spent administering each injection was 6.4 (±6.5) minutes. Switching from current dosing practices to Q2W could decrease the mean number of syringes used from 12,420 to 5,085 per year. We estimate a reduction in the number of disinfective tissues and liquids of 58% and 71%, respectively by switching from current practice to dosing ESAs Q2W. Conclusions: There was significant variation in the time that it takes to perform routine ESA activities. We estimate that a reduction in resources required to manage anemia can be obtained by reducing the frequency of administration from the current mix of ESAs. These resources could be redeployed for patient care

Torasemide, a new potent diuretic. Double-blind comparison with furosemide.

The pharmacodynamic effects of torasemide, a new potent loop diuretic, were compared with those of furosemide in a double blind controlled study in 18 hypertensive patients with oedema of various origins. Given orally for 5 days, torasemide was clinically very effective and well tolerated. On a weight basis, the diuretic, natriuretic and chloruretic effects of torasemide were about 8-times greater than those of furosemide. However, the kaliuretic effect of torasemide was only 3-times greater than that of furosemide, suggesting that torasemide is more potassium sparing than furosemide. Torasemide displayed a rapid onset of action, similar to that of furosemide but had a longer diuretic effect without any rebound phenomenon. Torasemide and furosemide did not effect creatinine clearance or uric acid excretion. Both furosemide and torasemide lowered systolic blood pressure but the effect of torasemide was more marked than that of furosemide. In this group of aged and hypertensive patients with oedema, the pharmacokinetics of torasemide was comparable to that reported in young healthy volunteers, and were similar on the first and fifth days of treatment. The long duration of action and the potassium sparing effect of torasemide compared to furosemide are promising features of this new loop diuretic in the treatment of oedema and hypertension.Clinical TrialComparative StudyControlled Clinical TrialJournal ArticleRandomized Controlled Trialinfo:eu-repo/semantics/publishe

Comparison of the efficacy and safety of amikacin once or twice-a-day in the treatment of severe gram-negative infections in the elderly.

The aim of this study was to compare the efficacy and safety of amikacin given either as single injection or as two injections within 12-h interval in the treatment of severe gram-negative infections in elderly patients. Thirty-nine non-selected consecutive patients of a general internal medicine facility were randomized to receive the same total daily dose of amikacin either as a single dose (19 patients) or divided into two doses injected at 12-h interval (20 patients). Amikacin was used alone or in combination with metronidazole, clindamycin, fosfomycin or a beta-lactam. Clinical and bacteriological responses were satisfactory and comparable in the two groups. There was no difference between the once/day and the twice-a-day groups with respect to drug dosage, duration of therapy and concomitant treatment. Only one patient (BID group) showed a rise of serum creatinine during the observation period. Amikacin alone or in combination can be regarded as an efficacious and safe antibiotic in the treatment of severe gram-negative infections in elderly patients, whether the daily dose is administered in a single infusion or in a BID interval.Clinical TrialComparative StudyJournal ArticleRandomized Controlled Trialinfo:eu-repo/semantics/publishe

Comparative pharmacodynamics of torasemide and furosemide in patients with oedema.

The pharmacodynamics of torasemide (1-isopropyl-3- ([4-(3-methyl-phenylamino)pyridine]-3-sulfonyl)urea), a new potent loop diuretic, were compared to those of furosemide in a double-blind controlled study in 18 patients with oedema of various origin. Torasemide behaved like furosemide in exerting a potent diuretic effect which culminated during the first 4 h after its administration. Nevertheless, torasemide was about 8 times more potent, exerted a longer lasting diuretic effect and was more potassium sparing than furosemide. Torasemide did not accumulate during repeated administration (5 days). It was well tolerated and efficient in the treatment of oedema due to congestive heart failure and hepatic cirrhosis. The long duration of action and the potassium sparing effect of torasemide compared to furosemide are promising features of this new potent loop diuretic.Clinical TrialComparative StudyControlled Clinical TrialJournal ArticleRandomized Controlled Trialinfo:eu-repo/semantics/publishe

Aztreonam in the treatment of serious gram-negative infections in the elderly.

The efficacy and safety of aztreonam in the treatment of serious gam-negative infections were investigated in 20 patients, 19 of whom were more than 60 years old. There were 13 cases of upper urinary tract infection, 6 of septicemia and one of peritonitis. Half the patients were in a critical clinical condition with significant severe underlying disease. Aztreonam was given i.v. or i.m. in doses ranging from 1.5 to 4 g/day according to the severity of the infection. The duration of treatment ranged from 7 to 20 days. In 5 patients with mixed infections due to gram-positive and anaerobic organisms in addition to gram-negative pathogens, aztreonam was given in combination with clindamycin and metronidazole as appropriate. Clinical and bacteriological cures were observed in all 20 patients. There were two cases of reinfection and 3 of superinfection--all occurred in patients with severe underlying disease. Untoward effects were few and of minor severity. Creatinine clearance remained stable or improved during aztreonam treatment, even in patients with significant renal impairment. In conclusion, aztreonam was shown to be both effective and safe in the treatment of serious gram-negative infections in elderly patients--even those with impaired renal function. In such indications aztreonam appears to be a good alternative to potentially toxic drugs such as the aminoglycosides.Journal Articleinfo:eu-repo/semantics/publishe

Failure of indomethacin to impair the diuretic and natriuretic effects of the loop diuretic torasemide in healthy volunteers.

The effects of torasemide, a new potent loop diuretic, on renin release, water and sodium excretion were investigated in young healthy volunteers before and after 3 days of treatment with indomethacin. Torasemide 20 mg i.v. induced a rapid and biphasic increase both in plasma renin activity and plasma angiotensin II levels, which was almost completely abolished by pretreatment with indomethacin. Torasemide also increased urine volume, sodium excretion and, during the first hour after dosing, the creatinine clearance. None of the latter effects was impaired by indomethacin pretreatment. It is concluded that, like other loop diuretics, torasemide stimulates renin release by increasing renal prostaglandin production. However, at variance with what is observed with other loop diuretics, the diuretic and natriuretic effects of torasemide as well as the change in creatinine clearance do not appear to be inhibited by indomethacin.Journal ArticleResearch Support, Non-U.S. Gov'tinfo:eu-repo/semantics/publishe