Mu- and delta-opioid receptor antagonists decrease proliferation and increase neurogenesis in cultures of rat adult hippocampal progenitors

Opioids have previously been shown to affect proliferation and differentiation in various neural cell types. In the present study, cultured rat adult hippocampal progenitors (AHPs) were shown to release beta-endorphin. Membrane preparations of AHPs were found to bind [125I]beta-endorphin, and immunoreactivity for mu- and delta-opioid receptors (MORs and DORs), but not for kappa-opioid receptors (KORs), was found on cells in culture. Both DNA content and [3H]thymidine incorporation were reduced after a 48-h incubation with 100 microM naloxone, 10 micro m naltrindole or 10 microM beta-funaltrexamine, but not nor-binaltorphimine, suggesting proliferative actions of endogenous opioids against MORs and DORs on AHPs. Furthermore, analysis of gene and protein expression after incubation with MOR and DOR antagonists for 48 h using RT-PCR and Western blotting suggested decreased signalling through the mitogen-activated protein kinase (MAPK) pathway and lowered levels of genes and proteins that are important in cell cycling. Cultures were incubated with naloxone (10 or 100 microM) for 10 days to study the effects on differentiation. This resulted in an approximately threefold increase in neurogenesis, a threefold decrease in astrogliogenesis and a 50% decrease in oligodendrogenesis. In conclusion, this study suggests that reduced signalling through MORs and DORs decreases proliferation in rat AHPs, increases the number of in vitro-generated neurons and reduces the number of astrocytes and oligodendrocytes in culture.     

Consequences of mild stroke in persons <75 years -- a 1-year follow-up

BACKGROUND AND PURPOSE: Mild strokes can be neglected regarding subtle sequels as fatigue, and cognitive and emotional changes. We have addressed this topic by exploring late consequences of an initially mild stroke (Barthel score >or=50). Accordingly, we assayed impairment, disability and handicap data 1 year after the first-ever stroke in persons <75 years, focusing on symptoms as fatigue, concentration difficulties, memory disturbances, emotional lability, stress resistance, anxiety and uneasiness, symptoms comprised in the astheno-emotional disorder (AED), and its relation to life satisfaction. RESULTS: The mean value of the Barthel Index was 99.5 (SD 0.5) and 25% scored 0-1 on the Oxford Handicap Scale. AED was diagnosed in 71% of the patients, and fatigue was experienced by 72%. AED correlated significantly with life satisfaction, handicap and depression. Life satisfaction was significantly below that of norm values according to satisfaction with life as a whole, sex life and ability to manage selfcare. CONCLUSIONS: Our findings emphasize that 'hidden dysfunctions' not so easily discovered within the hospital context are common consequences of mild stroke. The concept of mild stroke as principally founded in motor function or ability in P-ADL therefore seems to be insufficient with respect to the patient long-term perspective.     

Effects of acute administration of DA agonists on locomotor activity: MPTP versus neonatal intracerebroventricular 6-OHDA treatment

The effects of several dopamine (DA) receptor agonists upon locomotor activity on adult MPTP-treated mice and postnatal 6-hydroxydopamine- (6-OHDA-) treated rats were assessed in ten experiments. C57 BL/6 mice were administered 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP, 2 x 40 mg/kg, s.c., 24-hr interval between injections) at 5-months-age, while 1-day-old male Wistar rat pups were given intracisternal 6-OHDA (50 mg, once following desipramine, 25 mg/kg). MPTP-treated mice were tested 4-5 weeks following MPTP injections whereas neonatal 6-OHDA rats were tested at 3-months-age. Locomotor activity was measured in respective activity test chambers following acute administration of DA receptor agonists. In MPTP-treated mice, apomorphine failed to elevate locomotor activity but instead further exacerbated (1.0 and 3.0 mg/kg, s.c.) the hypokinesia of these animals while inducing marked increases in control mice. Cabergoline (0.3 mg/kg, s.c.) and bromocriptine (3.0 mg/kg, s.c.) caused dose-specific elevations of locomotion in MPTP and control mice but suppressed activity at the highest doses. Quinpirole (0.2 mg/kg) and 7-hydroxydipropylaminotetralin (7-OH-DPAT; 300 nmole/kg) increased locomotion in hypokinesic MPTP-treated mice; in control mice, activity was elevated by quinpirole (0.2 and 0.7 mg/kg) and 7-OH-DPAT (100 and 300 nmole/kg), while higher doses suppressed activity. Neither SKF 38393 (1-phenyl-2,3,4,5-tetrahydro-1H-3-benzazepine-7,8-diol) nor FCE 23884 [4-(9,10-didehydro-6-methylergolin-8 beta-yl) methyl-piperazine-2,6-dione] affected locomotor activity. Apomorphine (0.3, 1.0 and 2.0 mg/kg), bromocriptine (3.0 mg/kg) and cabergoline (1.0 mg/kg) stimulated locomotion in sham-operated rats, and to a greater extent in the 6-OHDA-treated rats. Higher dose cabergoline (3.0 mg/kg) induced increased activity of similar extent in sham controls and 6-OHDA treated rats. Activity-enhancing effects of quinpirole (0.2, 0.7 and 2.1 mg/kg) in sham rats were attenuated in 6-OHDA treated rats. Both SKF 38393 (10 mg/kg) and FCE 23884 (0.3 and 1.0 mg/kg) induced locomotor activity increases in 6-OHDA, but not sham, rats. Finally, 7-OH-DPAT (1200 mg/kg) enhanced activity in 6-OHDA rats vs. shams. The effects of the DA agonists are discussed with regard to the putative antihypokinesic effects in MPTP mice and DA-receptor supersensitivity effects in neonatal 6-OHDA rats, pertaining to their more-or-less selective subreceptor profiles.     

Alzheimer disease ethics--informed consent and related issues in clinical trials: results of a survey among the members of the Research Ethics Committees in Sweden

The rapid advances in biomedical sciences have induced special moral and ethical attitudes, which ought to be taken into account. One of the most essential issues is the principles for participation in research of subjects with reduced decision-making capacity. We conducted a questionnaire survey among members of the research ethics committees in Sweden to find out their attitudes to a range of ethical issues related to research on subjects with Alzheimer's disease. One hundred thirty-six of those approached responded (66%), and 117 of the responses (56%) were considered substantially complete. There were 16 questions with fixed reply alternatives. Some central questions concerned the informed consent process. With a few exceptions, there were no significant differences in attitudes between the experts and laypersons, between persons of different ages, and between men and women. However, women and laypersons were in general keener to preserve the patient's integrity and the experts were more willing than the laypersons to allow participation of subjects with dementia in placebo-controlled trials.     

Role for M5 muscarinic acetylcholine receptors in cocaine addiction

Muscarinic cholinergic receptors of the M5 subtype are expressed by dopamine-containing neurons of the ventral tegmentum. These M5 receptors modulate the activity of midbrain dopaminergic neurons, which play an important role in mediating reinforcing properties of abused psychostimulants like cocaine. The potential role of M5 receptors in the reinforcing effects of cocaine was investigated using M5 receptor-deficient mice in a model of acute cocaine self-administration. The M5-deficient mice self-administered cocaine at a significantly lower rate than wild-type controls. In the conditioned place preference procedure, a classic test for evaluating the rewarding properties of drugs, M5-deficient mice spent significantly less time in the cocaine-paired compartment than control mice. Moreover, the severity of the cocaine withdrawal syndrome (withdrawal-associated anxiety measured in the elevated plus-maze) was significantly attenuated in mice lacking the M5 receptor. These results demonstrate that M5 receptors play an important role in mediating both cocaine-associated reinforcement and withdrawal.     

Role of phosphatidylinositol 3-kinase in neuronal survival and axonal outgrowth of adult mouse dorsal root ganglia explants

Adult ganglionic peripheral neurons have lost dependence on target-derived neurotrophin signaling for survival and regeneration after injury. To understand the mechanisms required to sustain such processes at maturity, we are studying neuronal survival and axonal outgrowth of adult mouse dorsal root ganglia (DRG) explants. We have here examined the role of phosphatidylinositol 3-kinase (PI3-K) activity. Both neuronal survival and axonal outgrowth of spontaneously growing preparations were decreased significantly by the PI3-K inhibitor LY294002 as was the increased outgrowth caused by nerve growth factor or glial cell line-derived factor. Inhibition of PI3-K activity promoted neuronal cell death to the same extent in the presence as in the absence of a growth factor, whereas inhibition of mitogen-activated protein kinase, MAPK, lacked effect. Using a compartmentalized system, it could be shown that only axonal outgrowth was decreased when the outgrowth region only was exposed to LY294002. Already-formed growth cones showed morphological changes within 5-10 min after exposure to LY294002. Akt (PKB) is one downstream effector of PI3-K. Immunofluorescence revealed the presence of activated Akt in DRG cell bodies and in axonal growth cones. Immunoreactivity was decreased by PI3-K inhibition. The results suggest that Akt is constitutively active in adult DRG neurons, and that PI3-K mediated processes are involved in neuronal survival of one or more DRG neuronal subpopulations and also in axonal elongation. The possible significance of Akt signaling for these effects is discussed.     

General parental education in Sweden: participants and non-participants

OBJECTIVE: To study factors of importance for participation in parental education within routine child health care. DESIGN: All parents of children born during 1 year were invited by the district nurse to participate in parental education; their participation during the infant year was registered. SETTING: Catchment area of two health centres in V?xj?, Sweden. SUBJECTS: 221 infants and their parents. MAIN OUTCOME MEASURES: Number of educational sessions for mothers and fathers. RESULTS: 63% of mothers and 20% of fathers attended at least one session. These mothers attended a mean of 5.7 (SD 2.2) sessions and these fathers a mean of 2.8 (SD 2.3) sessions. Logistic regression analyses showed that the only variable of significance for participation was being a first-time parent (odds ratio 3.9 for the mothers and 3.7 for the fathers). Odds ratios above 2.0 (non-significant) were found for married mothers and Swedish mothers, as well as for Swedish fathers. CONCLUSION: It is still a considerable problem to get certain groups involved in routine parental education in Swedish child healthcare programmes.     

Decreasing incidence of malignant tumors of the paranasal sinuses in Sweden. An analysis of 141 consecutive cases at Karolinska Hospital from 1960 to 1980

We reviewed 141 cases of paranasal sinus tumors treated at Karolinska Hospital from 1960 to 1980. Of these tumors, 100 were located in the maxillary sinus, 32 in the ethmoidal sinuses, 8 in both the ethmoidal and maxillary regions, and 1 in the sphenoidal sinus. The male-to-female ratio was 2.1 to 1. Squamous cell carcinoma and adenocarcinoma were the most frequent types of tumors (55% and 13%, respectively). Treatment included surgery, irradiation, or both. The 5-year survival rate was 34% for squamous cell carcinomas and 64% for adenocarcinomas. When compared to a previous material of patients treated at the same hospital from 1940 to 1950, the proportion of poorly differentiated squamous cell carcinomas had increased significantly. The age-adjusted incidence rate decreased from 1.2 to 0.4 for male patients and from 0.7 to 0.3 for female patients between 1960 and 1980. We conclude that the incidence of malignant paranasal sinus tumors has decreased, and that squamous cell tumors now seem to be generally less differentiated than they were 50 years ago.