| 1. |
- Ahlborg, Gunnar, 1948, et al.
(författare)
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Reproductive effects of chemical exposures in health professions
- 1995
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Ingår i: Journal of Occupational and Environmental Medicine. - 1076-2752. ; 37:8, s. 957-61
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Forskningsöversikt (refereegranskat)abstract
- Numerous chemical substances are handled by persons working in the health care sector. At exposure levels that may occur in the occupational setting, some of these substances are potentially harmful to the reproductive processes. Among the potentially harmful substances are anesthetic gases, antineoplastic agents, and sterilants. The epidemiological evidence of increased risks for adverse reproductive effects (eg, subfertility, spontaneous abortions, congenital defects) from such exposure is not unequivocal. However, due to the toxic potential, exposures should be kept at a minimum, and this may be especially important for workers who are pregnant or are planning to achieve pregnancy.
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| 2. |
- Deshpande, J, et al.
(författare)
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Ultrastructural changes in the hippocampal CA1 region following transient cerebral ischemia: evidence against programmed cell death.
- 1992
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Ingår i: Experimental brain research. Experimentelle Hirnforschung. Expérimentation cérébrale. - 0014-4819. ; 88:1, s. 91-105
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Tidskriftsartikel (refereegranskat)abstract
- The ultrastructural changes in the pyramidal neurons of the CA1 region of the hippocampus were studied 6 h, 24 h, 48 h, and 72 h following a transient 10 min period of cerebral ischemia induced by common carotid occlusion combined with hypotension. The pyramidal neurons showed delayed neuronal death (DND), i.e. at 24 h and 48 h postischemia few structural alterations were noted in the light microscope, while at 72 h extensive neuronal degeneration was apparent. The most prominent early ultrastructural changes were polysome disaggregation, and the appearance of electron-dense fluffy dark material associated with tubular saccules. Mitochondria and nuclear elements appeared intact until frank neuronal degeneration. The dark material accumulated with extended periods of recirculation in soma and in the main trunks of proximal dendrites, often beneath the plasma membrane, less frequently in the distal dendrites and seldom in spines. Protein synthesis inhibitors (anisomycin, cycloheximide) and an RNA synthesis inhibitor (actinomycin D), administered by intrahippocampal injections or subcutaneously, did not mitigate neuronal damage. Therefore, DND is probably not apoptosis or a form of programmed cell death. We propose that the dark material accumulating in the postischemic period represents protein complexes, possibly aggregates of proteins or internalized plasma membrane fragments, which may disrupt vital cellular structure and functions, leading to cell death.
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| 3. |
- Zygmunt, P M, et al.
(författare)
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Calcium channels at the adrenergic neuroeffector junction in the rabbit ear artery
- 1993
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Ingår i: Naunyn-Schmiedeberg's Archives of Pharmacology. - 0028-1298. ; 347:6, s. 23-617
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Tidskriftsartikel (refereegranskat)abstract
- Neurotransmitter release is dependent on influx of Ca2+ through voltage-operated calcium channels (VOCCs). These channels may be divided into L, N, T and P subtypes. To investigate the subtypes of VOCC involved in transmitter release from adrenergic nerves in the isolated rabbit ear artery, the effects of some subtype selective VOCC antagonists were examined on contractile responses induced by electrical field stimulation (EFS), and exposure to an isosmolar (low Na+, normal Cl- content) or a hyperosmolar (normal Na+, high Cl- content) 60 mM K+ solution. Tetrodotoxin (TTX) and the L channel blocker nimodipine were present in the latter experiments to inhibit sodium-dependent action potential discharge and the direct contractile effect of K+ depolarization on the smooth muscle cells. Prazosin abolished the contractile effect of EFS, indicating that the response was elicited by activation of adrenergic nerves. The EFS-induced contractions were concentration-dependently inhibited by the N channel blocker omega-conotoxin (pIC50 = 9.0) and the proposed L channel blocker T-cadinol (pIC50 = 4.5), while nimodipine and the T channel blocker tetramethrin had no effect. The isosmolar and hyperosmolar K+ solutions induced a prazosin-sensitive contraction, amounting to 46% and 10% of the response to 10(-5) M noradrenaline (NA), respectively. omega-Conotoxin inhibited the contractile response to the hyperosmolar K+ solution, but not that to the isosmolar K+ solution. T-cadinol preferentially inhibited the response to the hyperosmolar K+ solution. Tetramethrin had no effect on contractions induced by either type of K+ solution.(ABSTRACT TRUNCATED AT 250 WORDS)
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| 4. |
- Carlsson, Maria L., 1959, et al.
(författare)
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The 5-HT2A receptor antagonist M100907 is more effective in counteracting NMDA antagonist- than dopamine agonist-induced hyperactivity in mice
- 1999
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Ingår i: J Neural Transm. - 0300-9564. ; 106:2, s. 123-9
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Tidskriftsartikel (refereegranskat)abstract
- The purpose of the present study was to compare the effectiveness of the selective 5-HT2A antagonist M100907 in different psychosis models. The classical neuroleptic haloperidol was used as reference compound. Two hyperdopaminergia and two hypoglutamatergia mouse models were used. Hyperdopaminergia was produced by the DA releaser d-amphetamine or the DA uptake inhibitor GBR 12909. Hypoglutamatergia was produced by the un-competitive NMDA receptor antagonist MK-801 or the competitive NMDA receptor antagonist D-CPPene. M100907 was found to counteract the locomotor stimulant effects of the NMDA receptor antagonists MK-801 and D-CPPene, but spontaneous locomotion, d-amphetamine- and GBR-12909-induced hyperactivity were not significantly affected. Haloperidol, on the other hand, antagonized both NMDA antagonist- and DA agonist-induced hyperactivity, as well as spontaneous locomotion in the highest dose used. Based on the present and previous results we draw the conclusion that 5-HT2A receptor antagonists are particularly effective against behavioural anomalies resulting from hypoglutamatergia of various origins. The clinical implications of our results and conclusions would be that a 5-HT2A receptor antagonist, due to i a the low side effect liability, could be the preferable treatment strategy in various disorders associated with hypoglutamatergia; such conditions might include schizophrenia, childhood autism and dementia disorders.
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| 5. |
- Greiff, Lennart, et al.
(författare)
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Effects of topical platelet activating factor on the guinea-pig tracheobronchial mucosa in vivo
- 1997
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Ingår i: Acta Physiologica Scandinavica. - 0001-6772. ; 160:4, s. 387-391
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Tidskriftsartikel (refereegranskat)abstract
- Platelet activating factor (PAF) has been reported to produce a variety of airway effects including epithelial damage and increased airway-lung absorption of hydrophilic tracers. The present study examines effects of PAF on the guinea-pig tracheobronchial mucosa in vivo. Vehicle with and without PAF (4.0 and 8.0 nmol) was superfused onto the tracheobronchial mucosa. The levels of 125I-albumin, previously given intravenously, were determined in tracheobronchial lavage fluids as an index of mucosal exudation of plasma. The mucosa was also examined by scanning electron microscopy. In separate animals, 99mTc-DTPA (a low molecular weight, 492 Da, hydrophilic tracer) was superfused onto the mucosal surface through an oro-tracheal catheter, together with vehicle or PAF (8.0 nmol). A gamma camera determined the disappearance rate of 99mTc-DTPA from the airways as an index of mucosal absorption. PAF produced dose-dependent mucosal exudation of plasma up to 20-fold greater than control (P < 0.001). However, PAF did not damage the epithelium and the absorption ability of the airway mucosa was unaffected. The results, in contrast to previous reports, suggest that PAF may not readily damage the airway mucosa even at large exudative doses of the agent. The present finding support the view that the plasticity of the epithelial junctions allows the creation of valve-like paracellular pathways for unidirectional clearance of extravasated plasma into the airway lumen. We suggest that endogenous PAF may participate in first line respiratory defence reactions by causing lumenal entry of bulk plasma without harming the epithelium.
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| 6. |
- Grundemar, L, et al.
(författare)
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Suppression by neuropeptide Y of capsaicin-sensitive sensory nerve-mediated contraction in guinea-pig airways
- 1990
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Ingår i: British Journal of Pharmacology. - : Wiley. - 0007-1188. ; 99:3, s. 473-476
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Tidskriftsartikel (refereegranskat)abstract
- 1. In the present study we have examined whether neuropeptide Y (NPY) interferes with non-adrenergic, non-cholinergic nerve-mediated contractions and relaxations in the guinea-pig airways. In these experiments we have used ring preparations of bronchi and trachea, incubated in the presence of atropine, propranolol and indomethacin (each 1 microM). 2. The contractile response to electrical stimulation of non-adrenergic, non-cholinergic nerve fibres was suppressed by NPY and NPY 13-36 in a concentration-dependent manner, these agents having similar inhibitory potencies. NPY caused a more complete inhibition than the C terminal fragment. 3. NPY affected neither the basal tension nor the substance P-evoked contraction in the bronchi and trachea and did not interfere with nerve-mediated, non-adrenergic relaxation in the trachea. 4. On the basis of these results, it is suggested that NPY may act on the terminals of sensory neurones in the airways to prevent antidromic, excitatory neurotransmission by inhibiting transmitter release.
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| 7. |
- Kjellgren, Karin I, 1950, et al.
(författare)
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Hypertensive patients' knowledge of high blood pressure.
- 1997
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Ingår i: Scandinavian journal of primary health care. - 0281-3432. ; 15:4, s. 188-92
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: To investigate hypertensive patients' understanding of the circulatory system, in particular high blood pressure. DESIGN: Semi-structured audio-taped interviews of patients immediately after a regular follow-up appointment with their physician. SETTING: A primary health care centre and a specialist clinic (hypertension unit) in southern Sweden. PATIENTS: 33 hypertensive patients, consecutively selected. MAIN OUTCOME MEASURE: Focus was set on the exploration of patients' understanding/knowledge. RESULTS: In spite of a long history of hypertensive care, on average ten years, patients had a less than satisfactory understanding of their condition. Most patients knew their blood pressure values, but very few were able to give an account of what high blood pressure implies in functional terms. Knowledge of high blood pressure seems mainly to be derived from sources other than the health care system, in particular from the mass media. Knowledge of the risks associated with hypertension was quite good, as was the insight into how these risks could be managed. CONCLUSION: An assessment of patient knowledge of high blood pressure ought to be a starting point for educational strategies that aim to deepen patients' understanding of their state of health.
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| 8. |
- Kjellgren, Karin I, 1950, et al.
(författare)
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Patients' and physicians' assessment of risks associated with hypertension and benefits from treatment.
- 1998
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Ingår i: Journal of cardiovascular risk. - 1350-6277. ; 5:3, s. 161-6
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Perceptions of effects of a medical regimen may affect patients' adherence to therapy. OBJECTIVE: To assess concordance between patients' and physicians' estimations of the risks of hypertension and benefits of treatment during a regular follow-up appointment. DESIGN: A population-based Swedish multicentre study. Patients were included consecutively from a randomized selection of centres (55 primary health care centres and 11 clinics of internal medicine). METHODS: A questionnaire was given to 1013 patients undergoing their individually prescribed antihypertensive therapy and 212 physicians who were caring for these patients. RESULTS: Without therapy, patients perceived the risks of cardiovascular complications to be higher than did their physicians. Patients were not aware that an increasing number of risk factors has an impact on the risk of complications. Patients furthermore rated the benefits of treatment higher than did their physicians (P<0.001). Of the patients, 14% had blood pressures < or = 140/90 mmHg. Most of the patients (61%) were not aware of their target blood pressure. However, when the target pressure was communicated to patients by the physician, patients remembered it accurately. The patients were generally not willing to trade even minor side effects from antihypertensive therapy for benefits of treatment. CONCLUSIONS: There was a high degree of inconsistency between patients' and physicians' estimations of risks of hypertension. Patients estimated the effects of treatment to be more beneficial than did their physicians.
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| 9. |
- Axelsson, Gösta, 1950, et al.
(författare)
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Shift work, nitrous oxide exposure, and spontaneous abortion among Swedish midwives
- 1996
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Ingår i: Occupational and Environmental Medicine. - 1351-0711. ; 53:6, s. 374-8
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVES: To study the relation between irregular work hours, nitrous oxide (N2O) exposure, and the risk of spontaneous abortion. METHODS: All 3985 female members of the Swedish Midwives Association in 1989, born in 1940 or later, received a questionnaire on exposure before and during all of their pregnancies. Questions on work conditions covered occupation, extent of employment, workplace, work schedules, use of anaesthetics, and work load. The association between exposure variables and spontaneous abortion was analysed by logistic regression models. RESULTS: Night work and three shift schedules among midwives showed increased odds ratios (ORs) (95% confidence intervals (95% CI)) 1.63 (0.95-2.81) and 1.49 (0.86-2.59), respectively. The ORs of late spontaneous abortions (after the 12th week of pregnancy) was increased for night work 3.33 (1.13-9.87). Use of N2O (> 50% of the deliveries) was not associated with increased risk of spontaneous abortion OR 0.95 (0.62-1.47). Frequent or permanent shortage of staff was related to an increased risk of spontaneous abortions before the 13th week of pregnancy. CONCLUSIONS: The results support the hypothesis that night work and high work load increase the risk of spontaneous abortion.
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| 10. |
- Johansson, C, et al.
(författare)
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Nitric oxide synthase inhibition blocks phencyclidine-induced behavioural effects on prepulse inhibition and locomotor activity in the rat.
- 1997
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Ingår i: Psychopharmacology. - 0033-3158. ; 131:2, s. 167-73
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Tidskriftsartikel (refereegranskat)abstract
- The ability of the nitric oxide synthase inhibitor, NG-nitro-L-arginine methyl ester (L-NAME), to block the behavioural effects of the potent psychotomimetic, phencyclidine, was tested in rats using two different behavioural models. L-NAME was found to block both phencyclidine-induced disruption of prepulse inhibition of acoustic startle and phencyclidine-induced stimulation of locomotor activity. A selective action of L-NAME on the effects of phencyclidine was indicated, since L-NAME did not alter the effects of amphetamine, another potent psychotomimetic, in these behavioural models. These observations suggest that a nitric oxide-dependent mechanism may be involved in the effects of phencyclidine in the central nervous system.
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