Behavioural and ECoG spectrum changes induced by intracerebral infusion of interferons and interleukin 2 in rats are antagonized by naloxone.

Rat interferon, alpha-interferon, interleukin 2 and recombinant interleukin-2 injected into the third cerebral ventricle produced typical behavioural sedation and/or sleep and ECoG synchronization in rats while beta-interferon produced no behavioural sleep or ECoG synchronization. A slight sedation was observed after the largest dose of beta-interferon only. During sleep induced by lymphokines, a dose-dependent increase in total voltage power as well as in the 0.5-3, 4-7 and 12-16 Hz frequent bands was observed. Much smaller doses were required to produce similar behavioural and ECoG spectrum effects after infusion of interferons and interleukin-2 into the locus coeruleus. No significant behavioural and ECoG changes were obtained after infusion of the same doses of interferons and interleukin-2 into other areas of the brain (caudate nucleus, dorsal hippocampus, substantia nigra pars compacta, ventromedial hypothalamus). The behavioural and ECoG effects of alpha-interferon, rat interferon and interleukin-2 were blocked in animals pretreated with naloxone. These results are consistent with the hypothesis that the behavioural and ECoG effects of these lymphokines are mediated at locus coeruleus level by stimulation of opiate receptors.     

The CTLA-4 gene region of chromosome 2q33 is linked to, and associated with, type 1 diabetes. Belgian Diabetes Registry

Susceptibility to autoimmune insulin-dependent (type 1) diabetes mellitus is determined by a combination of environmental and genetic factors, which include variation in MHC genes on chromosome 6p21 (IDDM1) and the insulin gene on chromosome 11p15 (IDDM2). However, linkage to IDDM1 and IDDM2 cannot explain the clustering of type 1 diabetes in families, and a role for other genes is inferred. In the present report we describe linkage and association of type 1 diabetes to the CTLA-4 gene (cytotoxic T lymphocyte associated-4) on chromosome 2q33 (designated IDDM12). CTLA-4 is a strong candidate gene for T cell- mediated autoimmune disease because it encodes a T cell receptor that mediates T cell apoptosis and is a vital negative regulator of T cell activation. In addition, we provide supporting evidence that CTLA-4 is associated with susceptibility to Graves' disease, another organ- specific autoimmune disease.      

Effect of L-arginine on thymic function. Possible role of L-arginine: Nitric oxide (no) pathway

The thymus and in particular its epithelial component produces hormonal peptides which are required for differentiation of stem cells into mature T-cells. With advancing age, there occurs a progressive reduction of the plasma level of one of the best known thymic peptides, i.e. thymulin. In old mice, oral supplementation with arginine (9x10(-4) gr/day/mouse) for 1 month is able to induce a regrowth of the thymus and recovery of the reduced thymulin plasma level to the values observed in young animals. The direct immunological target of arginine seems to be the thymus gland. In fact, the transplantation of thymus from old arginine treated mice into young thymectomized recipients is able to restore thymulin plasma level in thymectomized recipients to nearly the same level as do thymuses from young mice. Furthermore, arginine supplementation young thymectomized recipients is unable to induce the reappearance of thymulin activity in the blood. With regard to the mechanism of action of arginine, two pathways may be suggested. The first one may be indirect and mediated by the secretagogue action of arginine on growth hormone. The second one, may rely on a direct action through the L-arginine: NO pathway. Lymphocyte-depleted thymic explants from young mice, when incubated in vitro with the NO-synthetase inhibitor L-NAME (6 mM), are, in fact, incapable of producing and realising thymulin in the supernatant. The in vitro addition of L-arg (60 mM) is able to recover such a production to the values observed in supernatants of control thymic cultures. The present findings offer the first evidence that also the thymic endocrine activity is modulated by L-arginine:NO pathway.     

Unnecessary repeat Clostridium difficile PCR testing in hospitalized adults with C. difficile-negative diarrhea

The aim of this study was to determine the extent and associated costs of repeat Clostridium difficile stool polymerase chain reaction (PCR) assays in patients with initially negative PCRs. C. difficile stool PCRs were done on adult hospitalized patients with diarrhea. The number/time course of repeat PCRs on initially negative PCR patients was determined. Of 5,027 C. difficile stool PCRs, 814 (16.2 %) were positive and 4,213 (83.8 %) were negative. Ninety-seven of the initially PCR-negative patients had >2 repeat tests 1–59 days after the initial negative stool PCR. Repeat negative PCR testing rarely resulted in a subsequent positive result (0.05 %). The unnecessary costs of 97 repeat PCRs was $32,658.00. Many of these patients were originally given empiric oral anti-C. difficile therapy, in spite of repeatedly negative PCRs.     

Effects of L-DOPA on GABA metabolism in chick brain and retina

The effects of an oral subacute treatment with l-DOPA on GAD, GABA and GABA-T in chick n. basalis (homologous to the mammalian striatum), brain hemispheres, brain-stem and retina were studied. A significant increase in n. basalis GAD activity associated with an increase in GABA content and decrease of GABA-T activity was shown to occur. Similar effects were observed in the brain-stem except for GABA-T which was stimulated. In contrast, in brain hemispheres, l-DOPA produced a decrease in GAD and GABA-T activity. No changes, however, were observed in GAD activity at the retinal level, whereas GABA-T activity was significantly decreased and GABA content increased. In conclusion, the present experiments show that in some areas of the brain the administration of l-DOPA is able to affect GABA turnover.     

Anticonvulsant properties of flunarizine on reflex and generalized models of epilepsy

The anticonvulsant activity of 1-bis(4-fluorophenyl)methyl-4-(3-phenyl-2-propenyl)-piperazine, flunarizine, was studied after intraperitoneal administration in DBA/2 mice (seizures induced by sound), intravenous administration in Papio papio (myoclonus induced by photic stimulation) and oral administration in Wistar rats (seizures induced by cefazolin). Protection against sound-induced seizures was observed after intraperitoneal administration of flunarizine (5-40 mg/kg). The ED50 for suppression of tonic, clonic and wild running phases of sound-induced seizures was 3.3, 9.8 and 17.5 mg/kg, respectively. This protective action was significantly reduced by pretreatment with aminophylline (50 mg/kg, i.p.). In photosensitive baboons flunarizine (0.5-1.0 mg/kg, i.v.) provided partial protection against myoclonic responses to stroboscopic stimulation. After flunarizine (2 mg/kg, i.v.) this protection lasted for more than 5 hr (and was complete at 2-3 hr). Cefazolin-induced seizures in rats were prevented by administration of flunarizine (20-40 mg/kg, orally). The ED50 for the suppression of tonic and clonic seizures evoked by subsequent intravenous administration of cefazolin was 25 mg/kg. The protective effects of flunarizine (40 mg/kg, orally) were maximal after 3-6 hr and were maintained for 16-24 hr. Behavioural effects of flunarizine included signs of sedation in both mice and rats. Tolerance to the antiepileptic effects of flunarizine was not seen after chronic treatment in rats. The role of purinergic receptors and of calcium entry blockade in the anticonvulsant action of flunarizine requires further study.     

Effects of catecholamines and adenosine derivatives given into the brain of fowls

1. Adult fowls (Gallus domesticus) with cannulae chronically implanted into the IIIrd cerebral ventricle and various other sites of the brain received microinfusions or injections of catecholamines, adenosine, 3′,5′-cyclic AMP or its dibutyryl derivative. The effects of these substances on behaviour, electrocortical activity and body temperature were studied.

2. Behavioural and electrocortical sleep with fall in body temperature were obtained with intraventricular noradrenaline, α-methylnoradrenaline and isoprenaline; dopamine was ineffective. The doses required to elicit sleep were smaller than those affecting body temperature. Following mebanazine, the effects of noradrenaline were prolonged and doses of dopamine, previously ineffective, lowered body temperature and induced behavioural and electrocortical sleep.

3. Noradrenaline, α-methylnoradrenaline, isoprenaline and dopamine infused into the hypothalamus induced sleep and lowered body temperature. Effective doses of noradrenaline, α-methylnoradrenaline and isoprenaline infused into the hypothalamus were one-twentieth to one-fifth those for intraventricular injection. Tachypnoea developed with isoprenaline and dopamine. Additionally with dopamine, there was deviation of the head to the contralateral side, together with repetitive jerking movements of the head. These effects were prolonged and intensified by mebanazine, whereas the involuntary movements with dopamine were greatly reduced by haloperidol.

4. Involuntary movements, but without sleep, were induced by infusing dopamine into the paleostriatum augmentatum; noradrenaline infused into this site was ineffective.

5. In three of five fowls pretreated with aminophylline, 3′,5′-cyclic AMP infused into the hypothalamus induced behavioural and electrocortical sleep; without aminophylline pretreatment, 3′,5′-cyclic AMP was ineffective. Adenosine infused into the hypothalamus, following pretreatment of fowls with aminophylline, consistently induced behavioural and electrocortical sleep. Dibutyryl cyclic AMP infused into the hypothalamus of intact fowls elicited behavioural arousal, followed by bursts of electrocortical spikes (6 Hz) over both cerebral hemispheres, spikes subsequently becoming regular at 1 Hz. Clonic limb and body movements occasionally accompanied the bursts of spike activity, infrequently developing into convulsions. In fowl encéphale isolé preparations, in which dibutyryl cyclic AMP was infused into the hypothalamus, spike activity was confined to the ipsilateral hemisphere.

     

Weekly paclitaxel, 5-fluorouracil and folinic acid with granulocyte colony-stimulating factor support in metastatic breast cancer patients: a phase II study

We conducted a phase II study to determine the activity and tolerability of weekly paclitaxel, 5-fluorouracil (5-FU) and folinic acid plus granulocyte colony-stimulating factor (G-CSF) support in anthracycline-pre-treated or -resistant metastatic breast cancer patients. The phase II study was designed following the Simon optimal-two stage method. Patients received paclitaxel 80 mg/m, folinic acid 10 mg/m and bolus infusion of 5-FU 300 mg/m every week plus G-CSF on day 3 for 24 consecutive weeks in the absence of disease progression. From May 1998 to May 2000, 51 patients entered the study. Patients received a median relative dose intensity of 97.5% (range 81-100%). No severe toxicities were observed. Seven patients (14%) experienced neutropenia grade 2. Seven patients (14%) experienced grade 2 anemia. Two patients (4%) experienced severe asthenia. Three out of 50 evaluable patients [6%, 95% confidence interval (CI) 2-12.6%] showed a complete response, whereas 23 (46%, 95% CI 32.2-59.8%) had a partial response, with an overall response rate of 52% (95% CI 38.2-65.8%). In addition, eight patients (15.7%) had stable disease. In the 13 patients untreated for metastatic disease, the overall response rate was 92.3% (CI 77.8-100), with one complete response and 11 partial responses (84.6% CI 65-100%). In the whole group, the median time to progression and overall survival were 8 (range 1-18) and 14 months (95% CI 11-17), respectively. Thus, in metastatic breast cancer patients pre-treated with anthracyclines, the weekly administration of paclitaxel, 5-FU and folinic acid with G-CSF support seems to be extremely tolerable and active.