Immediate and Early Loading of Two-Implant-Supported Mandibular Overdentures: Three-Year Report of Loading Results of a Single-Center Prospective Randomized Controlled Clinical Trial.

Purpose: To report the clinical and radiographic outcomes of a 3-year follow-up of immediately and early loaded two-implant-supported mandibular overdentures.

Materials And Methods: Forty edentulous patients were randomly subdivided into two groups. In the immediate loading group, two Straumann implants were splinted with a Dolder bar and loaded with a mandibular overdenture within the first 48 hours postoperative.

Motor effects of a dopamine stabilizer (GMC1111) in primate models of Parkinson and hemiparkinsonism.

The effects on motor behavior of a new potential dopamine stabilizer: 2-amino-6-(N,N-di-n-propylamino)thiazolo[4,5-f]indan (GMC1111) were investigated in common marmosets with 6-hydroxydopamine lesions within the median forebrain bundle (12 unilateral, 6 bilateral). GMC1111 was administered orally or subcutaneously (s.c.

Acute and repeated treatment with L-DOPA increase c-jun expression in the 6-hydroxydopamine-lesioned forebrain of rats and common marmosets.

L-DOPA was acutely or repeatedly administered to rats and common marmosets (Callithrix jacchus) with unilateral 6-hydroxydopamine (6-OHDA) denervation of the dopamine inputs to the forebrain. Using in situ hybridization it was found that L-DOPA-treated animals exhibited a pronounced induction in the gene expression of both c-jun and c-fos in striatum and cerebral cortex restricted to the dopamine-depleted hemisphere. In contrast, acute treatment with cocaine induced c-fos mRNA, but not c-jun mRNA, in the striatum of normal animals.

Naloxone reduces levodopa-induced dyskinesias and apomorphine-induced rotations in primate models of parkinsonism.

Using in situ hybridization, it was found that subchronic treatment with levodopa/benserazide increased preproenkephalin-A and preproenkephalin-B mRNAs in the dopamine-depleted striatum. In order to examine whether dysfunction of the endogenous opioid system may underlie the development of levodopa-induced dyskinesias, the effect of naloxone, an opioid antagonist, on dyskinesias was investigated in two models of parkinsonism in the common marmoset. MPTP-treated monkeys were administered a daily oral dose of levodopa/benserazide which relieved the parkinsonian symptoms but induced severe and reproducible dyskinetic movements.

Tardive dyskinesia model in the common marmoset.

Thirteen adult common marmosets (Callithrix jacchus) were given once-monthly injections of haloperidol decanoate (5-15 mg/kg i.m.) for one year.

Coadministration of (-)-OSU6162 with l-DOPA normalizes preproenkephalin mRNA expression in the sensorimotor striatum of primates with unilateral 6-OHDA lesions.

The substituted phenylpiperidine (-)-OSU6162 is a novel modulator of the dopaminergic systems with low affinity for dopamine D(2) receptors and potent normalizing effects on l-DOPA-induced dyskinesias. We studied the effects of coadministration of (-)-OSU6162 with l-DOPA on the regulation of striatal preproenkephalin (PPE) and prodynorphin (PDyn) mRNA expression in the primate brain by in situ hybridization histochemistry. Common marmoset monkeys sustaining unilateral 6-hydroxydopamine lesions of the nigrostriatal pathway received l-DOPA/carbidopa, l-DOPA/carbidopa plus (-)-OSU6162, or vehicle over 14 days.

L-DOPA produces strong induction of c-fos messenger RNA in dopamine-denervated cortical and striatal areas of the common marmoset.

Common marmosets (Callithrix jacchus) with near-complete unilateral 6-hydroxydopamine denervation of the dopaminergic input received a single injection of saline or L-DOPA (15mg/kg plus 6.25mg/kg benserazide). Using in situ hybridization, the effects of these treatments on c-fos messenger RNA expression in the cerebral cortex, the striatal complex and the external layer of the pallidum were studied.

Motor effects of (-)-OSU6162 in primates with unilateral 6-hydroxydopamine lesions.

The effects of the novel compound, (-)-OSU6162 ((S)-(-)-3-methylsulfonylphenyl-1-propylpiperidine), on rotational behavior induced by dopamine receptor agonists was investigated in common marmosets (Callithrix jacchus) with unilateral 6-hydroxydopamine lesions. (-)-OSU6162 per se displayed no effect on the animals' behavior. On the other hand, pretreatment with (-)-OSU6162 attenuated rotational behavior induced by apomorphine (apomorphini hydrochloridum), L-DOPA (3,4-dihydroxyphenylalanine), and the dopamine D2 receptor agonist, quinpirole (trans-(-)-4aR-4,4a, 5,6,7,8,8a,9-octahydro-5-propyl-1H-pyrazolol[3,4-g]quinoline hydrochloride), without inducing motor impairment such as akinesia or dystonia.

(-)-OSU 6162 inhibits levodopa-induced dyskinesias in a monkey model of Parkinson's disease.

We have studied the effects of two D2 dopamine receptor-selective compounds, (-)-OSU 6162 and raclopride, on levodopa-induced dyskinesias in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-lesioned common marmosets (Callithrix jacchus). Three monkeys developed a severe parkinsonian syndrome following administration of MPTP. In response to daily levodopa treatment the animals developed reproducible and idiosyncratic peak-dose dyskinesias.

High frequency oral movements induced by long-term administration of amperozide but not FG5803 in rats.

Long-term studies of antipsychotic-induced oral movements may serve as a rat model of acute and tardive movement disorders. Vacuous chewing movements (VCM), tongue protrusions (TP), and jaw tremors (TR) were studied in rats during acute and chronic administration of two potential antipsychotics, amperozide and FG5803. Comparisons were made with haloperidol and vehicle.

Neuroleptics differentially modulate central dopamine D1-receptor binding.

The effect of the classical neuroleptic, fluphenazine, on dopamine D1-receptor binding was examined in different regions of the basal ganglia. Whereas exposure to fluphenazine for 18 months reduced [125I]SCH-23982 binding to D1-receptors in the caudate putamen, nucleus accumbens and olfactory tubercle, binding in the entopeduncular nucleus was enhanced after fluphenazine treatment. Competition studies indicated that the region-dependent changes in [125I]SCH-23982 binding after fluphenazine exposure were not due to differences in the affinity of fluphenazine or other dopamine ligands for D1-binding sites.

Behavioral and neurochemical consequences of ibotenic acid lesion in the subthalamic nucleus of the common marmoset.

Five marmosets were unilaterally lesioned within the subthalamic nucleus (STN) by injection of 10 micrograms ibotenic acid. Seven marmosets served as saline injected controls. The lesioned marmosets showed an increased locomotor activity, occasional tongue protrusions, posture asymmetry, and abnormal movements of the contralateral legs and arms.

Chronic treatment with a classical neuroleptic alters excitatory amino acid and GABAergic neurotransmission in specific regions of the rat brain.

The purpose of the following experiments was to describe some of the neurochemical changes that occur in the basal ganglia of rats exposed chronically to a classical neuroleptic, fluphenazine, and to relate these changes to extrapyramidal motor dysfunction. For these studies a combination of behavioural, receptor autoradiographic and in situ hybridization methods were employed. Preliminary pharmacological studies on GABA receptors showed that incubation in Tris-acetate rather than Tris-citrate buffer increased the number of binding sites labelled by [3H]muscimol by over 120% without affecting binding affinity or selectivity.

Intranigral stimulation of oral movements by [Pro9] substance P, a neurokinin-1 receptor agonist, is enhanced in chronically neuroleptic-treated rats.

Bilateral intranigral infusions of three different peptide agonists were made in rats exposed to fluphenazine decanoate, 30 mg/kg/month (FLU) or vehicle (CON) for seven months. Oral movements were monitored repeatedly during the neuroleptic pretreatment period, as well as before the intranigral infusion and during a 90-min period postinfusion. The FLU group had an increased frequency of vacuous chewing movements (VCM) during the pretreatment period in comparison to controls.

Modulation of oral movements by intranigral 5-hydroxytryptamine receptor agonists in the rat.

Bilateral infusion of 5-hydroxytryptamine (5-HT) agonists into the substantia nigra pars reticulata (SNr) of awake rats was shown to influence oral behavior. The 5-HT1A agonist (R)-8-hydroxy-2-(di-propylamino)- tetralin (8-OH-DPAT) (1.3-13 nmol on each side) produced a dose-dependent depression of vacuous chewing movements (VCMs) that lasted about 20 min.

An animal model for coexisting tardive dyskinesia and tardive parkinsonism: a glutamate hypothesis for tardive dyskinesia.

There is now ample evidence for long-term malfunctioning within five different brain GABAergic pathways in a monkey model for tardive dyskinesia (TD). Three of these GABA connections (GPe-STN, CP-SNr, and CP-GPi) are chronically downregulated during neuroleptic treatment and after some years they do not seem to regain their normal activity, even when the neuroleptics are discontinued. The persistent downregulation of these three GABA connections, evidenced by depressions of terminal GAD activity and GABA levels, appears to be a conceivable mechanism behind tardive parkinsonism (TP), often reported to coexist with TD in the clinic.

Regional changes in 2-deoxyglucose uptake associated with neuroleptic-induced tardive dyskinesia in the Cebus monkey.

The neural mechanisms that mediate a primate model of tardive dyskinesia have been investigated using the 2-deoxyglucose (2-DG) uptake technique. Three groups of Cebus monkeys were used. Some of the animals received long-term neuroleptic treatment.

Intranigral tachykinin NK3 receptor agonist elicits oral movements in rats.

Synthetic agonists for the tachykinin NK1 and NK3 receptors were bilaterally infused at three dose levels (4.2, 0.17, and 0.

Mortality in heroin addiction: impact of methadone treatment.

The mortality within a cohort of 115 street heroin addicts was studied for 5-8 years using the Kaplan-Meier survival estimate technique. This differed markedly from the relatively low mortality of 166 comparable heroin addicts given methadone maintenance treatment (MT). The street addicts' mortality rate was 63 times that expected, compared with official statistics for a group of this age and sex distribution.