Search results for " isolation"
showing 10 items of 374 documents
Co-expression of CD133+/CD44+in human colon cancer and liver metastasis
2013
Although relatively good therapeutic results are achieved in non-advanced cancer, the prognosis of the advanced colon cancer still remains poor, dependent on local or distant recurrence of the disease. One of the factors responsible for recurrence is supposed to be cancer stem cells (CSCs) or tumor-initiating cells, which are a population of cancer cells with ability to perpetuate themselves through self-renewal and to generate differentiated cells, thought to be responsible for tumor recurrence. This study globally approach the possible role of tissue-derived stem cells in the initiation of colon cancer and its metastatic process in the liver. Fresh surgical specimens from colon cancer, no…
Role of dopamine and glutamate receptors in cocaine-induced social effects in isolated and grouped male OF1 mice.
2005
Cocaine administration in paired male mice decreases social contacts as well as increases avoidance and flee elements. As dopamine (DA) and glutamate seem to be involved in some of cocaine's effects, an attempt was made to assess whether a range of associated receptors influenced the social impacts of this drug of abuse. The NMDA antagonist memantine (10 and 40 mg/kg); the AMPA antagonist CNQX (1 and 20 mg/kg); the DA release inhibitor CGS 10746b (2 and 8 mg/kg): the DA D1 antagonist SCH 23390 (0.05 and 0.5 mg/kg); and the DA D2/D3 antagonist raclopride (0.03 and 0.3 mg/kg) were administered prior to 25 mg/kg of cocaine and behaviour was evaluated during an encounter between an experimental…
Reproductive isolation among allopatric Drosophila montana populations
2014
An outstanding goal in speciation research is to trace the mode and tempo of the evolution of barriers to gene flow. Such research benefits from studying incipient speciation, in which speciation between populations has not yet occurred, but where multiple potential mechanisms of reproductive isolation (RI: i.e., premating, postmating-prezygotic (PMPZ), and postzygotic barriers) may act. We used such a system to investigate these barriers among allopatric populations of Drosophila montana. In all heteropopulation crosses we found premating (sexual) isolation, which was either symmetric or asymmetric depending on the population pair compared. Postmating isolation was particularly strong in c…
The experiences of older individuals providing care to older dependents: A phenomenological study in Spain
2021
Objective Non-professional care provided in domestic settings by a family member or someone from the close environment and without a connection to a professional care service, is increasingly assumed by older people, mainly the spouses of those requiring care. The aim of this study was to describe the experience of older people providing care at home to older dependents. Methods A qualitative study was carried out to describe and explore the experience of older people, caregivers of dependent older people in the home. Results Four themes emerged as a result of the analysis: interpersonal relationships established in the caregivers’ immediate environment; the need and request for public and…
Genetic elimination of known pheromones reveals the fundamental chemical bases of mating and isolation in Drosophila
1999
Overexpression of the UAS-tra transgene in Drosophila melanogaster females led to the complete elimination of their cuticular pheromones. According to current models of Drosophila behavior, these flies should induce no courtship. In fact, they are still attractive to conspecific males. Three classes of stimuli are shown to induce courtship, with different effects on male behavior: ( i ) known pheromones produced by control females, ( ii ) stimuli produced by living control and transgenic flies, and ( iii ) as-yet-undetermined pheromones present on both control and transgenic flies. Only the latter class of pheromones are required for mating. They appear to represent a layer of ancestral at…
A "double hit" murine model for schizophrenia shows alterations in the structure and neurochemistry of the medial prefrontal cortex and the hippocamp…
2013
Both alterations in neurodevelopment and aversive experiences during childhood and adolescence seem important risk factors for schizophrenia. Animal models reproducing these alterations mimic some of the symptoms, constituting a valid approach to study the etiopathology of this disorder. Among these models, the perinatal injection of N-methyl-d-aspartate receptor antagonists and the postweaning social isolation rearing are among the most widely used. Our aim is to combine them in a "double hit" model, which should produce a wider spectrum of alterations. Lister Hooded rats have been subjected to a single injection of MK-801 at postnatal day 7 and socially isolated from postweaning to adulth…
Reputation, loneliness, satisfaction with life and aggressive behavior in adolescence
2008
The present study analyses the relationship between adolescents' perception of reputation and aggressive behavior among peers. The sample is made up of 1319 adolescents aged 11 to 16 years old. Statistical analyses with structural equation modeling were carried out to examine the direct and indirect effect of perception of reputation (real and ideal) on aggressive behavior. Results indicate that adolescents' real and ideal reputations are related both directly and indirectly to aggressive behavior. The indirect effects suggest that loneliness and life satisfaction mediate the relationship between adolescents' reputation and their aggressive behavior. These findings and their implications ar…
Friendship Moderates Prospective Associations Between Social Isolation and Adjustment Problems in Young Children
2007
This longitudinal study investigated prospective links between social isolation and adjustment problems among 166 (77 girls, 89 boys) Finnish children ages 7 to 9. Peer nominations for social engagement and self‐reports of internalizing and externalizing problems were collected in the spring of the 1st and 2nd grade. Friendship moderated prospective associations between peer and adjustment variables. Among friended children, there were no prospective associations between social isolation and either internalizing or externalizing problems. Among unfriended children, initial social isolation was positively linked to subsequent increases in internalizing and externalizing problems, and initial…
Effects of risperidone and SCH 23390 on isolation-induced aggression in male mice.
1998
In this study, the antiaggressive effects of risperidone and SCH 23390 have been explored. Using the paradigm of isolation-induced aggression, 150 albino male mice of the OF1 strain were allocated to control and experimental groups which received three doses of risperidone (0.01, 0.05 and 0.1 mg/kg) or two doses of SCH 23390 (0.05 and 0.1 mg/kg). Only the highest doses of risperidone decreased threat and attack behaviours but all doses significantly impaired motor behaviour. SCH 23390 decreased attack with the two doses used and also produced significant increases in immobility. Although both antipsychotics are antiaggressive, this action seems to be more specific in the case of risperidone…
Isolation decreases physical and motivational aspects of morphine withdrawal
2005
Environmental manipulations such as social housing conditions of animals may play a role in the expression of individual differences in response to drugs. This study aimed to evaluate whether isolated and grouped mice develop different degrees of morphine dependence. Isolated and grouped mice were rendered morphine dependent employing two different methods of induction: a fast or slow protocol, both reaching the same maximum daily dose (100 mg/kg). Naloxone-induced morphine withdrawal was assessed using a modified Gellert-Holtzman scale and a conditioned place aversion (CPA) procedure. Isolated animals manifested fewer signs of physical dependence than grouped mice and only those receiving …