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At least 1,405 records · Page 78Linked to original sources
PubMed1982

Enamel microstructure determination in hominoid and cercopithecoid primates.

Enamel structure was determined in primate teeth by scanning electron microscopy. It was found that the important organisational features of this tissue can be determined solely from the examination of developing material and that significant differences in internal structure of the mature tissue are reflected in differences in the surface (cell-matrix interface) of the developing tissue. Several very conservative, relatively non-destructive techniques can be used to acquire information from fully formed teeth, whereas the examination of small areas of heavily etched mature tissue samples may be inadequate or provide biased or misleading information. Pattern 3 prism packing occurs predominantly in Hominoidea, Pattern 2 in Cercopithecoidea. Pattern 1 was found in the one callitricid and the one lemur specimen studied.

Animals↗
PubMed1985

Reduction and binding of arsenate in marmoset monkeys.

The metabolism of 74As-arsenate (As V, 0.4 mg As/kg body weight, IV) in marmoset monkeys (two males and two females) was studied. Unlike all other animal species studied so far, the marmoset was found to be unable to metabolize the arsenate to dimethylarsinic acid. Most of the absorbed arsenate was reduced to arsenite (As III) in vivo. Only 20% was excreted in the urine as unchanged As V. A further 20% of the dose was excreted as As III. The rest of the As III produced was bound to the tissues, giving a distribution picture very similar to that reported earlier for marmoset monkeys given arsenite. The tissues with longest retention of arsenic were the liver, upper gastrointestinal tract (oral cavity and esophagus), skin, kidneys and gall bladder. The pronounced accumulation in the liver resulted from specific binding of arsenic to the rough microsomal membranes, unique to this animal species.

Animals↗
PubMed1995

Identifying genes within microdissected genomic DNA: isolation of brain expressed genes from a translocation region associated with inherited mental illness.

An improved protocol has been developed for physical enrichment of cDNA sequences by hybridization to genomic DNA. When applied to microdissection recombinants derived from a translocation breakpoint region associated with inherited mental illness, a single cycle of the procedure permitted enriched cDNAs to be visualized directly by agarose gel electrophoresis. Hybridization screening of a library of clones derived from the enriched cDNAs, employing the genomic resource as a probe, led to the identification of six novel gene fragments. This general approach to the isolation of regionally encoded genes could be applied to any subchromosomal interval as a first step towards global transcription map construction.

Animals↗
PubMed1995

Species-independent expression of nitric oxide synthase in the sarcolemma region of visceral and somatic striated muscle fibers.

The expression and distribution of nitric oxide synthase (NOS) was studied by use of the newly designed specific histochemical NADPH diaphorase staining method and the indirect immunofluorescence technique employing an antiserum to brain NOS in visceral and somatic striated muscles of several mammalian species. Histochemical activity and immunoreactivity were located in the sarcolemma region of type I and II fibers of all muscles investigated. Visceral muscles were more strongly stained than somatic muscles. Furthermore, type II fibers, identified by staining of myosin adenosine triphosphatase activity after pre-incubation at alkaline pH, were more intensely labeled than type I fibers. In addition, NOS activity was detected in the area of the sarcolemma of intrafusal fibers. No obvious differences between species were observed. It was concluded that NOS of striated muscles probably makes up the richest and most important nitric oxide source in mammals.

Animals↗
PubMed1981

An involvement of dopamine in higher order choice mechanisms in the monkey.

Low doses of amphetamine induce choice perseveration in an object discrimination task under conditions where such perseveration either increases or decreases the number of rewards obtained as compared to chance performance. Neither stereotyped motor actions nor repetitive choice of position contributed to this effect which could be blocked by pre-treatment with the neuroleptic haloperidol. These results demonstrate that higher order choice mechanisms may involve dopamine systems in the primate.

Animals↗
PubMed1981

Perseverative behaviour after amphetamine; dissociation of response tendency from reward association.

Low doses of amphetamine were found to alter the ability of marmosets to take account of changes in reward values of object stimuli in a visual discrimination task. Under amphetamine, animals changed their motor responses and stimulus choice in order to preserve the acquired reward value or meaning of certain stimuli. These results suggest that the perseverative effect of amphetamine on behaviour is due to impaired cognitive flexibility rather than to an enhancement of motor habit.

Animals↗
PubMed1988

The motor innervation of the soft palate. An anatomical study in guinea pigs and monkeys.

In an effort to gain a more precise understanding of the motor innervation of the soft palate, a neuroanatomical tracer (horseradish peroxidase) was injected into the vela of nine guinea pigs and four monkeys. After 48 h the animals were sacrificed and frozen frontal sections were appropriately reacted with tetramethylbenzidine and counterstained with neutral red, and then evaluated by means of light microscopy. In all specimens retrogradely labeled neurons appeared in the brain stem. The distribution patterns of these labeled cells were to a large degree comparable in both the guinea pigs and the monkeys. The complex motor innervation of the soft palate was found to involve at least five different centers, with the strongest staining seen in the nucleus ambiguus and the motor nucleus of the trigeminal nerve. Additional cells of origin were discernible in the retrofacial nucleus. Facial neurons, however, were labeled only occasionally. Findings also showed that a previously undescribed component from the hypoglossal nerve appears to be essential for lateral soft palate movement in both animal models.

Animals↗
PubMed1992

Parkinson's disease: pathological mechanisms and actions of piribedil.

The cause of the degeneration of dopamine-containing cells in the zona compacta of the substantia nigra in Parkinson's disease remains unknown. The ability of the selective nigral toxin 1-methyl-4-phenyl-1,2,3,6 tetrahydropyridine (MPTP) (via its metabolite MPP+) to destroy nigral dopamine cells selectively by inhibiting complex I of the mitochondrial energy chain may provide a clue. Indeed, recent studies of post-mortem brain tissue have suggested the presence of an on-going toxic process in the substantia nigra in Parkinson's disease leading to excess lipid peroxidation. This appears also to involve a disruption of mitochondrial function since mitochondrial superoxide dismutase activity is increased and there is impairment of complex I. These changes may in turn relate to a selective increase in the total iron content of substantia nigra coupled to a generalised decrease in brain ferritin content. Piribedil is used in the symptomatic treatment of Parkinson's disease and is particularly effective against tremor. Piribedil (and its metabolites) acts as a dopamine D-2 receptor agonist. However, in our studies in contrast to other dopamine agonists, in vivo piribedil interacts with dopamine receptors in the substantia nigra and nucleus accumbens but not those in the striatum. In patients with Parkinson's disease the beneficial effects of piribedil may be limited by nausea and drowsiness. Indeed, in MPTP-treated primates piribedil reverses motor deficits but marked side-effects occur. However, pre-treatment with the peripheral dopamine receptor antagonist domperidone prevents the unwanted effects and piribedil produces a profound and longer-lasting reversal of all components of the motor syndrome.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1992

Dietary modulation of lipid metabolism and mechanical performance of the heart.

Sudden Cardiac Death resulting from sustained ventricular fibrillation or malignant cardiac arrhythmia has been linked to the type of dietary fat intake in several economically well developed countries where high levels of saturated fatty acids are common. Experimental studies with the small non-human primate marmoset monkey have clearly demonstrated the health benefit of substituting polyunsaturated fatty acids (PUFA's) for dietary saturated fatty acids. Heart rate and blood pressure are lowered, while the left ventricular ejection fraction and the electrical threshold for the induction of ventricular fibrillation are both increased after prolonged feeding of PUFA enriched diets. All these changes in heart function reduce the risk of developing malignant cardiac arrhythmias. The fatty acid composition of cardiac membrane phospholipids is profoundly altered by these changes in dietary lipid intake. In particular the proportions of arachidonic acid (AA), eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are altered in such a way that the production of myocardial eicosanoids is affected. Although the changes in proportion of these long-chain PUFA's in cardiac phosphatidyl ethanolamine and phosphatidyl inositol are not identical, the shift in balance between these substrates or inhibitors of cyclo-oxygenase activity leads to relatively greater production of prostacyclin (PGI2) than thromboxane (TXA2).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1995

Short and long-term changes in cerebral [14C]-2-deoxyglucose uptake in the MPTP-treated marmoset: relationship to locomotor activity.

The "short-term" (0.7 +/- 0.1 months post-MPTP) and "long-term" effects (36.7 +/- 4.4 months) of MPTP treatment on motor behaviour and [14C]-2DG uptake were investigated in the common marmoset. The subcutaneous administration of MPTP greatly reduced locomotor activity (-94% with respect to controls) and induced motor disability in the "short-term" MPTP-treated marmoset group. In the "long-term" MPTP group, MPTP treatment did not significantly affect locomotor activity (-27% with respect to controls) and there was partial recovery of motor disability. In the "short-term" MPTP group, there were increases in [14C]-2DG uptake in the GPl (+31 to +37%), SNc (+34 to +42%), VTA (+35%), LC (+23%), PPN (+19%) and in the VA (+19%), VL (+20%) and AM (+17%) thalamic nuclei. [14C]-2DG uptake was decreased in the STN (-15%). In the "long-term" MPTP group, [14C]-2DG uptake was increased in the GPl (+18%), SNc (+27%), VTA (+25%), PPN (+19%), ventral caudate nucleus (+18 to +23%), NAc (+22%), F.Ctx (+18%) and in the VA (+34%), VL (+28%), AV (+33%) and AM (+24%) thalamic nuclei. [14C]-2DG uptake was unchanged in the STN. The increase in metabolic activity of the surviving DA neurones and/or the reactive gliosis may account for the initial increase in [14C]-2DG uptake in the SNc and VTA. On the other hand, in the "long-term" MPTP-treated animals the increase in [14C]-2DG uptake in the SNc (though less than in the "short-term" MPTP group), ventral caudate and NAc may reflect the regenerative changes in the dopaminergic system in these areas. Despite the behavioural recovery, [14C]-2DG uptake remained elevated in the target areas for medial pallidal output (the thalamic nuclei and PPN). However, the attenuation of the changes in [14C]-2DG uptake in the GPl and STN of "long-term" MPTP-treated marmosets suggest that the striato-GPl and GPl-STN outputs closely reflect motor function in this primate model of Parkinson's disease.

1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine↗
PubMed1993

The lytic transition of Epstein-Barr virus is imitated by recombinant B-cells.

Lytic transition of Epstein-Barr virus (EBV) is initiated by distinct immediate early regulators of the viral cycle, in synchronization to temporary, permissive conditions during host cell differentiation. We developed eukaryotic vectors suitable to imitate the processes involved in lytic transition in cell culture systems. Two stable B cell lines were established: R59Z activator cells were used to induce lytic EBV expression in a constitutive manner by the production of the BZLF 1 trans-activator (Zta). R7-57 reporter cells, on the other hand, signaled induced activity of the lytic origin of EBV replication (ori Lyt). Different modes, like chemical induction, lytic superinfection with EBV and single gene trans-activation converted the recombinant ori Lyt element in R7-57 reporter cells. BZLF 1, transiently expressed in R7-57 reporter cells, was the only EBV trans-activator found, sufficient in inducing the viral lytic cycle. Basing on these experiments, trans-cellular activation of EBV was tested by cocultivation of BZLF 1-expressing R59Z activator cells with the R7-57 reporter line. No lytic effect on the reporter cells could be measured, neither by cocultivation of activator cells nor by coincubation of BZLF 1-containing cell lysates. Latency breaking activity, however, was transferred from activator to reporter cells when active, exogenous virus was added. The cell system described in these experiments provides a tool for the detection of EBV reactivation and demonstrates the potential of the lytic regulatory gene BZLF 1.

Animals↗
PubMed1996

Characterization and localization of the rat, mouse and human testicular phosphatidylethanolamine binding protein.

A cytosolic 23kDa protein was initially purified from bovine brain and shown to bind phosphatidylethanolamine. Later, it was also characterized in rat and human brain, and it is now known to be widespread, having been found in numerous tissues in several species. Here, we report the high level of mRNA and phosphatidyl ethanolamine binding protein expression in rat testis and to a lesser extent in mouse testis. In human testis, although it was not detectable by Northern blot analysis, the mRNA was shown to be present when PCR amplification was performed. Immunohistochemical experiments revealed that the testicular phosphatidylethanolamine binding protein (tPBP) is principally expressed in the elongated spermatids of both rat and mouse testis. This finding, and the association of tPBP with cellular membranes, suggest its possible implication in membrane remodelling during spermatid maturation.

Amino Acid Sequence↗
PubMed1991

Motor activity following the administration of selective D-1 and D-2 dopaminergic drugs to normal common marmosets.

In normal common marmosets administration of the D-1/D-2 agonist apomorphine or the selective D-2 agonist quinpirole caused a dose-dependent increase in motor activity and induced stereotyped behaviour. Both the selective D-2 antagonist raclopride and the selective D-1 antagonist SCH 23390 inhibited normal locomotor activity and induced catalepsy. Quinpirole- and apomorphine-induced motor activity were potently inhibited by pretreatment with raclopride. The effects of quinpirole, but not apomorphine, were weakly inhibited by SCH 23390. The selective D-1 partial agonist SKF 38393 decreased motor activity and did not induce grooming, oral movements or other behaviours. SKF 38393 inhibited motor activity induced by the administration of quinpirole but did not alter apomorphine-induced motor behaviour. Locomotor activity in normal common marmosets appears to be mediated mainly via D-2 systems. In contrast to rodents, administration of SKF 38393 does not induce behavioural activation and there does not appear to be a facilitating effect of D-1 systems on D-2 function in the normal common marmoset. However, the ability of both SKF 38393 and SCH 23390 to inhibit quinpirole locomotor activity suggests some interaction between D-1 and D-2 systems to occur in this species.

2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-ben↗
PubMed1992

Motor activity following the administration of selective D-1 and D-2 dopaminergic drugs to MPTP-treated common marmosets.

The ability of selective D-1 agonist and antagonist drugs to alter motor deficits and locomotor activity was studied in MPTP-treated common marmosets. Both the D-2 agonist quinpirole and the mixed D-1/D-2 agonist apomorphine reversed the motor impairments and induced locomotor activity. The D-1 antagonist SCH 23390 and the D-2 antagonist raclopride given alone further reduced motor function in MPTP-treated animals. The actions of quinpirole were potently and completely inhibited by raclopride but only partially and inconsistently by SCH 23390. In contrast, the effects of apomorphine were markedly but incompletely inhibited by both raclopride and SCH 23390. The D-1 agonist SKF 38393 alone caused a dose related reduction in motor activity. SKF 38393 weakly and partially inhibited the improvements in motor function produced by quinpirole but had a more pronounced effect on apomorphine induced motor activity. The induction of motor activity in MPTP treated common marmosets may separately involve both D-1 and D-2 receptors. Comparison with our previous data on the effect of the same drugs in normal common marmosets provides some evidence for a breakdown of linkage between D-1 and D-2 systems following MPTP treatment. The actions of SKF 38393 in MPTP-treated common marmosets contrasts with its ability to induce behavioural activation and a facilitation of D-2 mediated behaviour in rodents. SKF 38393 may not be the compound with which to delineate the role of D-1 receptors in primates.

1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine↗
PubMed1995

Differential anti-parkinsonian effects of benzazepine D1 dopamine agonists with varying efficacies in the MPTP-treated common marmoset.

In common marmosets systemically treated with MPTP (1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine), the behavioural effects of benzazepine D1 dopamine (DA) agonists with full/supramaximal (SKF 80723 and SKF 82958), partial (SKF 38393, SKF 75670 and SKF 83565) and no efficacies (SKF 83959) in stimulating adenylate cyclase (AC) activity were investigated. The benzazepine derivatives, with the exception of SKF 82958 (8 fold D1 DA receptor selectivity), demonstrated high D1 DA receptor affinity and selectivity (approximately 100 fold or more) in rat striatal homogenates. Administration of MPTP in marmosets induced locomotor hypoactivity, rigidity and motor disability. SKF 38393 (7,8-dihydroxy-1-phenyl-2,3,4,5-tetrahydro-1H-3- benzazepine) and SKF 75670 (3-CH3 analogue) further reduced locomotor activity (by -70 to -80%) and increased motor disability (by +22 to +67%) in these animals. SKF 83565 (6-Cl, 3-CH3, 3'-Cl analogue) and SKF 82958 (6-Cl, 3-C3H5 analogue) had only a slight effect on locomotor activity but decreased motor disability at high doses (-46 to -60%). In contrast, SKF 83959 (6-Cl, 3-CH3, 3'-CH3 analogue) and SKF 80723 (6-Br analogue) produced pronounced increases in locomotion (6-10 fold) and a reversal in motor disability (by -64 to -77%). Oral activity, consisting largely of abnormal, 'dyskinetic' tongue protrusions and vacuous chews, was increased in animals treated with SKF 38393, SKF 83565, SKF 82958 and more especially with SKF 80723 and SKF 83959. Grooming was increased with SKF 82958 and more especially with SKF 80723 and SKF 83959. In contrast, quinpirole (D2 DA agonist), reversed the MPTP-induced motor deficits in the marmoset, with no effect on grooming and oral activity. The present findings further demonstrate the antiparkinsonian actions of some D1 DA agonists in MPTP-treated primates. However, in general the behavioural effects of benzazepines failed to correlate with either their D1 DA receptor affinity/selectivity or their efficacy in stimulating adenylate cyclase (AC) activity. These observations further implicate a behavioural role for D1 DA receptors uncoupled to AC and/or a role for extrastriatal D1 DA receptors in mediating the behavioural response to D1 DA agonists.

1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine↗