Silvio Garattini

How to increase value and reduce waste when research priorities are set

The increase in annual global investment in biomedical research--reaching US

Inflammatory cytokines and related genes are induced in the rat hippocampus by limbic status epilepticus

240 billion in 2010--has resulted in important health dividends for patients and the public. However, much research does not lead to worthwhile achievements, partly because some studies are done to improve understanding of basic mechanisms that might not have relevance for human health. Additionally, good research ideas often do not yield the anticipated results. As long as the way in which these ideas are prioritised for research is transparent and warranted, these disappointments should not be deemed wasteful; they are simply an inevitable feature of the way science works. However, some sources of waste cannot be justified. In this report, we discuss how avoidable waste can be considered when research priorities are set. We have four recommendations. First, ways to improve the yield from basic research should be investigated. Second, the transparency of processes by which funders prioritise important uncertainties should be increased, making clear how they take account of the needs of potential users of research. Third, investment in additional research should always be preceded by systematic assessment of existing evidence. Fourth, sources of information about research that is in progress should be strengthened and developed and used by researchers. Research funders have primary responsibility for reductions in waste resulting from decisions about what research to do.

Studies on behavioral and biochemical changes in rats after lesion of midbrain raphé

Limbic status epilepticus was induced in rats by unilateral 60‐min electrical stimulation of the CA3 region of the ventral hippocampus. As assessed by RT‐PCR followed by Southern blot analysis, transcripts of interleukin‐1β, interleukin‐6, interleukin‐1 receptor antagonist and inducible nitric oxide synthase were significantly increased 2 h after status epilepticus in the stimulated hippocampus. Induction was maximal at 6 h for interleukin‐1β (445%), interleukin‐6 (405%) and tumour necrosis factor‐α (264%) and at 24 h for interleukin‐1 receptor antagonist (494%) and inducible nitric oxide synthase (432%). In rats with spontaneous seizures (60 days after status epilepticus), interleukin‐1β mRNA was still higher than controls (241%). Immunocytochemical staining of interleukin‐1β, interleukin‐6 and tumour necrosis factor‐α was enhanced in glia with a time‐course similar to that of the respective transcripts. Sixty days after status epilepticus, interleukin‐1β immunoreactivity was increased exclusively in neurons in one third of the animals. Multiple intracerebroventricular injections of interleukin‐1 receptor antagonist (0.5 μg/3 μL) significantly decreased the severity of behavioural convulsions during electrical stimulation and selectively reduced tumour necrosis factor‐α content in the hippocampus measured 18 h after status epilepticus. Thus, the induction of spontaneously recurring seizures in rats involves the activation of inflammatory cytokines and related pro‐ and anti‐inflammatory genes in the hippocampus. These changes may play an active role in hyperexcitability of the epileptic tissue.

Prognosis of Untreated Patients with Idiopathic Membranous Nephropathy

Abstract Lesions of the midbrain raphe in rats produced a marked decrease of 5-HT and 5-HIAA levels in the forebrain. An increase of spontaneous motor activity and an onset of signs of abnormal behaviour were observed. A good correlation has been found between the intensity of behavioural excitation and the decrease of 5-HT and 5-HIAA in the forebrain. Bioelectrical investigations of frontal cortical activity showed a persistent arousal in EEG pattern.

m-Chlorophenylpiperazine: A central serotonin agonist causing powerful anorexia in rats

Background Defining the most appropriate treatment for patients with idiopathic membranous nephropathy is a matter of controversy. The course of the disorder is often benign, and the immunosuppressive regimens used in some patients have uncertain benefits and substantial risks. We studied the natural history of idiopathic membranous nephropathy in patients who received only symptomatic therapy. Methods We prospectively studied 100 consecutive patients (68 men and 32 women; mean [±SD] age, 51 ±17 years) with biopsy-proved idiopathic membranous nephropathy. The patients received diuretic or antihypertensive drugs as needed, but no glucocorticoid or immunosuppressive drugs. We examined the patients and measured their urinary protein excretion and serum creatinine concentrations every 6 months for a mean of 52 months. Results Twenty-four (65 percent) of the 37 patients followed for at least five years had complete or partial remission of proteinuria; in 6 others (16 percent), end-stage renal disease developed...

Influence of dose and route of administration on the kinetics of fluoxetine and its metabolite norfluoxetine in the rat

SummaryMeta-chlorophenylpiperazine inhibited serotonin and noradrenaline uptake by synaptosomes to the same extent with IC50 of 1.3×10−6 M and 5.8×10−6 M respectively. Dopamine uptake was lesss affected by meta-chlorophenylpiperazine (IC50 of 2.2×10−5 M). Unlike d-amphetamine and d-fenfluramine, the drug did not significantly increase monoamine release in synaptosomal preparations. On the other hand, metachlorophenylpiperazine showed an IC50 of 620 nM in displacing 3H-5HT binding to brain membranes. Meta-chlorophenylpiperazine produced a dose-dependent reduction of food intake and this effect was prevented by a pretreatment with methergoline, a serotonin antagonist. The effect of metachlorophenylpiperazine was not modified by an intraventricular injection of 6-hydroxydopamine, electrolytic lesions of nucleus medianus raphe or ventral noradrenergic bundle, nor by a pretreatment with penfluridol, propranolol or phentolamine. The data suggest that the decrease of food intake induced by metachlorophenylpiperazine depends on its ability to act as a serotonin agonist in the brain. The specificity of the effects on serotonin suggests that this compound could prove an important tool for studies aimed at elucidating the functional role of serotonin in the central nervous system.

Neurochemical mechanism of action of drugs which modify feeding via the serotoninergic system

Fluoxetine (FL) is being used in neuropharmacology as a tool for studying various functional roles of serotoninergic neurons. Its kinetics was studied in rats, a species widely used in neurochemical studies, after IV (2.5–10 mg/kg) and oral (5–20 mg/kg) administration. When injected IV the drug followed apparent first-order kinetics up the 10 mg/kg dose. Its volume of distribution was large and total body clearance was relatively high compared to liver blood flow. The mean elimination half-lives (t1/2) of FL and its active metabolite norfluoxetine (NFL) were about 5 and 15 h, respectively. The mean blood:plasma concentration ratios of FL and NFL approached unity and plasma protein binding was 85–90% for both compounds. After oral doses the kinetics of FL were complex. At the lowest dose tested (5 mg/kg) the drug was efficiently extracted by the liver (extraction ratio about 60%), resulting in bioavailability of only about 38%. Plasma areas under the curve (AUC) of the metabolite were approximately the same as after IV injection of the same dose; consequently the metabolite-to-parent drug ratio after oral administration (about 5) was approximately twice that after IV injection of FL (about 2.5). At higher doses, however, the oral bioavailability (e.g.Cmax and AUC) appeared greater than expected, possibly because of transient saturation of FL first-pass metabolism in the case of the 10 mg/kg dose and concomitant saturation of elimination kinetics at the higher dose (20 mg/kg). The apparent eliminationt1/2 of FL markedly increased and the metabolite-to-parent drug ratio declined with the higher dose, this also being consistent with saturable elimination. Brain concentrations reflected the plasma kinetics of FL and NFL and the metabolite-to-parent drug ratio varied with dose and time of administration and was modified at the highest dose tested. FL and its metabolite NFL distributed almost evenly in discrete brain areas and subcellular distribution was similar for both compounds. Neurochemical studies of FL should consider the formation of the active metabolite NFL and extrapolation of data across animal species requires consideration of dose dependence in the rat.

Non-inferiority trials are unethical because they disregard patients' interests

The neurochemical mechanisms by which drugs acting on central serotoninergic system modify feeding were reviewed. Fenfluramine, a clinically effective appetite suppressant, releases serotonin from nerve terminals and inhibits its reuptake, and considerable evidence suggests that these effects mediate its anorectic activity. The D isomer of fenfluramine is particularly specific in affecting serotonin mechanisms and causing anorexia. Transmitters other than serotonin such as acetylcholine, catecholamines and GABA are also affected by systemic administration of fenfluramine, but some of these effects are secondary to fenfluramines action on serotoninergic mechanisms. Moreover, there is no evidence that these brain substances are involved in fenfluramines ability to cause anorexia. Several studies with drugs affecting different serotonin mechanisms such as release and uptake or mimicking the action of serotonin at post-synaptic receptors suggest that increase serotonin release and direct stimulation of postsynaptic receptors are the most effective mechanisms for causing depression of food intake, although inhibition of serotonin uptake may also contribute in appropriate conditions. Development of serotonin receptor hyposensitivity and, in some instances, decreased serotonin levels may lead to tolerance to the anorectic activity of drugs enhancing serotonin transmission, the degree of this depending critically on the type of effect on serotonin mechanisms and intensity and duration of serotonin receptor activation. Recent evidence suggests that a decrease in serotonin function causes stimulation of feeding. This may lead to development of new strategies for the treatment of clinical anorexias.

The effects of selective lesioning of brain serotonin or catecholamine containing neurones on the anorectic activity of fenfluramine and amphetamine

1have been widely used to assess new drugs, but have recently lost ground to a non-inferiority design. This type of trial is usually accepted by regulatory authorities for approval of new drugs or new indications, although the US Food and Drugs Administration has raised some concerns. 2 In this paper, we argue that the scientifi c community should ban non-inferiority and equivalence trials because they are unethical, whatever measures are taken to prevent their methodological pitfalls and inappropriate interpretation of results. 3–8

d- and l-isomers of fenfluramine differ markedly in their interaction with brain serotonin and catecholamines in the rat.

Abstract The effects of fenfluramine and amphetamine on food intake were studied in midbrain raphe-lesioned or in 6-hydroxydopamine-treated rats. Lesion of the midbrain raphe, which lowers forebrain serotonin, antagonized the anorectic effect of fenfluramine but did not modify the action of amphetamine. An intraventricular injection of 6-hydroxydopamine, which produced a marked decrease of brain noradrenaline and dopamine, did not affect the actions of either amphetamine or fenfluramine. A possible role of brain serotonin and catecholamines on anorexia induced by amphetamine and fenfluramine is discussed.