Biomedical subjects

J Westman

Publications and source records attributed to J Westman.

At least 19 recordsLinked to original sources

PubMed2006

Country of birth and hospital admission rates for mental disorders: a cohort study of 4.5 million men and women in Sweden.

This study analysed the association between country of birth and psychotic, affective, and neurotic disorders in seven immigrant categories, after adjustment for demographic and socioeconomic factors. A 2-year national cohort study of 4.5 million individuals in the age group 25-64 years was performed. Swedish national registers including individual demographic and socioeconomic data were linked to the hospital discharge register. Cox regression was used in the analysis. Several groups of immigrants, both men and women, had risks of hospital admission for psychotic, affective, or neurotic disorders compared to the Swedish-born reference group. The impact of demographic and socioeconomic factors on these risks seemed to be larger for men than for women. For foreign-born men, several of the risks no longer remained significant after adjustment for income and marital status. In contrast, most of the risks for foreign-born women remained significant after adjustment for income and marital status. Low income and being single were associated with an increased risk of psychiatric hospital admission. These results represent important knowledge for clinicians and public health planners who are involved in treatment and prevention of mental disorders among certain groups of immigrants, and among low income men and women irrespective of immigrant status.

Adult↗

PubMed2003

Antioxidant compounds EGB-761 and BN-52021 attenuate brain edema formation and hemeoxygenase expression following hyperthermic brain injury in the rat.

Role of carbon monoxide (CO) in hyperthermic brain injury induced brain pathology was examined in a rat model using immunohistochemistry of the hemeoxygenase-2 (HO-2) enzyme. Exposure of rats to 4 h heat stress at 38 degrees C resulted in profound hyperthermia, breakdown of the blood-brain barrier (BBB), brain edema formation, cell damage and expression of HO-2 in several brain regions. Pretreatment with potent antioxidant compounds EGB-761 and BN-52021 markedly reduced the HO-2 expression, BBB breakdown, brain edema formation and cell damage without attenuating the hyperthermic response. This effect was most marked in animals treated with EGB-761. These observations suggest that upregulation of HO-2 representing generation of CO plays important roles in hyperthermic brain injury, and oxidative stress seems to be one of the most important signals in inducing HO-2 expression in hyperthermia, not reported earlier.

Animals↗

PubMed2003

Depletion of endogenous serotonin synthesis with p-CPA attenuates upregulation of constitutive isoform of heme oxygenase-2 expression, edema formation and cell injury following a focal trauma to the rat spinal cord.

The possibility that the upregulation of hemeoxygenase (HO) enzyme responsible for carbon monoxide (CO) formation in the spinal cord following trauma is involved in edema formation and cell damage was examined in a rat model. A focal trauma to the rat spinal cord by making an incision into the right dorsal horn of the T10-11 segment resulted in profound upregulation of HO-2 (the constitutive isoform of the enzyme) expression in the T9 and T12 segments 5 h after injury. In these segments a marked increase in edema formation, nerve cell damage, and expression of heat shock protein (HSP 72) were observed. Pretreatment with p-chlorophenylalanine (p-CPA, a serotonin synthesis inhibitor) significantly attenuated the trauma induced edema formation, cell injury, and HSP expression. Upregulation of HO-2 in p-CPA treated traumatised rats was considerably reduced. These observations suggest that (i) spinal cord injury has the capacity to induce an upregulation of HO-2 and HSP expression, (ii) abnormal production of CO as reflected by HO-2 expression is injurious to the cord, and (iii) that endogenous serotonin is involved in HO-2 expression in the cord.

Animals↗

PubMed2003

Low molecular weight compounds with affinity to melanocortin receptors exert neuroprotection in spinal cord injury--an experimental study in the rat.

The possibility that five new low molecular weight compounds with varying affinity and selectivity to the melanocortin receptors will exert neuroprotective effects in the spinal cord injury (SCI) induced edema formation and cell damage was examined in a rat model. A focal trauma of the rat spinal cord made by an incision into the right dorsal horn (T10-11) resulted in profound edema formation, leakage of Evans blue albumin and cell injury of the T9 segment at 5 h. Topical application of the Melacure compound ME10501 in high doses (10 microg in 10 microl) given 5 min after SCI resulted in most significant neuroprotection of the T9 segment of the cord compared to other compounds. Thus, marked reduction in water content, leakage of Evans blue albumin, and cell injury were observed in ME10501 treated traumatised rats. These observations suggest that the non-peptide compound ME10501 with affinity to the melanocortin receptor MC4 is capable to induce neuroprotection in the spinal cord following trauma not reported earlier.

Animals↗

PubMed2003

Topical application of TNF-alpha antiserum attenuates spinal cord trauma induced edema formation, microvascular permeability disturbances and cell injury in the rat.

The possibility that antiserum to tumour necrosis factor-alpha (TNF-alpha) is neuroprotective in spinal cord injury (SCI) was examined in a rat model. SCI was produced by making an incision into the right dorsal horn at the T10-11 segments. Top TNF-alpha antiserum at three concentrations (1:10; 1:50 and 1:100) given 30 min before or 2 min, 5 min or 10 min after trauma resulted in marked reduction in visible swelling, edema formation, and leakage of radiolabelled iodine tracer within the T9 and T12 segments at 5 h in a dose dependent manner. This neuroprotective effect was most pronounced when the antiserum at the highest dose level (1:10) was applied 10 min after SCI. The TNF-alpha antiserum also reduced the SCI induced upregulation of neuronal nitric oxide synthase (nNOS) immunoreactivity in a concentration dependent manner. Taken together, these results suggest that local application of TNF-alpha antiserum is neuroprotective in SCI and that this effect is mediated through NOS regulation.

Administration, Topical↗

PubMed2003

An L-type calcium channel blocker, nimodipine influences trauma induced spinal cord conduction and axonal injury in the rat.

The influence of the potent L-type Ca[2+] channel antagonist Nimodipine on spinal cord evoked potentials (SCEP) and axonal injury following trauma to the spinal cord was examined in a rat model. Spinal cord injury (SCI) was produced by an incision into the right dorsal horn of the T10-11 segments under urethane anaesthesia (1.5 g/kg, i.p.). SCEPs were recorded by epidural electrodes placed over the T9 (rostral) and T12 (caudal) segments after stimulation of the right tibial and sural nerves. SCI induced a pronounced decrease of the SCEP negative amplitude in the rostral (T9) recordings immediately after trauma. Axonal injury seen as degradation of myelin basic protein (MBP) immunostaining and myelin vesiculation at the ultrastructural level was most pronounced at 5 h. Continuous administration of Nimodipine (2 microg/kg/min, i.v.) from 30 min prior to injury until sacrifice markedly attenuated the changes in SCEP amplitude and latency. Axonal damage, loss of MBP, and myelin vesiculation were much less evident in the nimodipine treated traumatised rats. These observations suggest that Ca[2+] channels play an important role in the trauma induced alterations in SCEP and axonal injury, and indicate a therapeutic value of Ca[2+] blockers in SCI.

Animals↗

PubMed2002

Topical application of dynorphin A (1-17) antiserum attenuates trauma induced alterations in spinal cord evoked potentials, microvascular permeability disturbances, edema formation and cell injury: an experimental study in the rat using electrophysiological and morphological approaches.

Dynorphin is a neuropeptide that is present in high quantities in the dorsal horn of the spinal cord. The peptide is actively involved in pain processing pathways. However, its involvement in spinal cord injury is not well known. Alteration in dynorphin immunoreactivity occurs following a focal trauma to the rat spinal cord. Infusion of dynorphin into the intrathecal space of the cord results in ischemia, cell damage and abnormal motor function. Antibodies to dynorphin when injected into the intrathecal space of the spinal cord following trauma improve motor recovery, reduce edema and cell changes. However, influence of dynorphin on trauma induced alteration in spinal cord bioelectrical activity is still not known. Spinal cord evoked potentials (SCEP) are good indicator of spinal cord pathology following trauma. Therefore, in present investigation, influence of dynorphin antibodies on trauma induced changes in SCEP were examined in our rat model. In addition, spinal cord edema formation, microvascular permeability disturbances and cell injury were also investigated. Our results show that topical application of dynorphin antiserum (1 : 200) two min before injury markedly attenuated the SCEP changes immediately after injury. In the antiserum treated animals, a significant reduction in the microvascular permeability, edema formation and cell injury was observed in the traumatised spinal cord. These observations suggest that (i). dynorphin is involved in the altered bioelectrical activity of the spinal cord following trauma, (ii). the peptide actively participates in the pathophysiological processes of cell injury in the spinal cord trauma, and (iii). the dynorphin antiserum has potential therapeutic value for the treatment of spinal cord injuries.

Animals↗

PubMed2002

Alkylaminopropenones and alkylamino-propenoates as efficient and versatile synthons in microwave-assisted combinatorial synthesis.

A simple and fast one-pot method using microwave irradiation for the synthesis of a number of small libraries of diverse heterocycles is described in this paper. The two-step one-pot method includes the formation of alkylaminopropenones or alkylaminopropenoates in 5 min at 180 degrees C and a subsequent treatment with dinucleophiles for 3 to 5 min at 150 degrees C to 180 degrees C to form a variety of biologically interesting heterocycles in a cascade-type reaction. The combination of combinatorial chemistry and microwave-assisted synthesis was found to be very efficient.

Amines↗

PubMed2001

An efficient combination of microwave dielectric heating and the use of solid-supported triphenylphosphine for Wittig reactions.

[reaction--see text] Olefins could be formed in an efficient way by the use of stable ylides in just a few minutes using microwave dielectric heating. The drawback with the Wittig reaction in solution phase is the formation of 1 equiv of triphenylphosphine oxide. To avoid this, the corresponding protocol using the efficient combination of solid-supported triphenylphosphine and microwave dielectric heating was developed. An even more efficient one-pot three-step Wittig reaction was also developed.

Journal Article↗

PubMed2001

Biomarkers of free radical injury during spinal cord ischemia.

Plasma and urinary levels of 8-iso-PGF(2alpha) and 15-keto-dihydro-PGF(2alpha) were analysed at baseline and during the ischemia-reperfusion period in experimental spinal cord ischemia. A significant and immediate increase of 8-iso-PGF(2alpha) in plasma at the start and up to 60 min, and in the urine at 90-150 min following ischemia indicate an association of oxidative injury. The inflammatory response indicator 15-keto-dihydro-PGF(2alpha) in plasma increased significantly at the start and up to 60 min after ischemia. No such increase was seen in animals with no spinal cord ischemia. Thus, free radical mediated and cyclooxygenase catalysed products of arachidonic acid are increased during spinal cord ischemia as a consequence of oxidative injury and inflammation.

Animals↗

PubMed2001

Monitoring of intrathecal oxygen tension during experimental aortic occlusion predicts ultrastructural changes in the spinal cord.

OBJECTIVE: To study the correlation between intrathecal PO2 and ultrastructural changes in the spinal cord during thoracic aortic occlusion in pigs. MATERIAL AND METHODS: In 18 pigs, online intrathecal oxygenation was monitored by a multiparameter Paratrend catheter (Biomedical Sensors, High Wycombe, United Kingdom) during 60 minutes' clamping of the proximal and distal descending thoracic aorta. The animals were randomly divided into 2 groups (A and B) depending on the level of distal aortic clamping. Distal aortic perfusion was restored through an aorto-iliac shunt, which also maintained low thoracic segmental perfusion of the spinal cord in group B. Perfusion-fixation technique was used before harvesting the spinal cord specimens, which later were evaluated with light and electron microscopy by an independent observer. Intrathecal parameters were interpreted as normal if PO2 was more than 0.8 kPa and PCO2 was less than 12 kPa, as intermediate ischemia if PO2 was 0.8 or less or PCO (2) was more than 12 kPa, and as absolute ischemia if PO2 was 0.8 or less and PCO2 was more than 12 kPa. RESULTS: Among 6 animals with ultrastructural changes of absolute spinal cord ischemia-reperfusion injury, 5 also had absolute ischemia according to variables derived by the Paratrend catheter. The 2 methods were in agreement in 3 of 5 animals with intermediate ischemia-reperfusion changes and in 5 of 6 animals with normal findings. The accuracy of cerebrospinal fluid PO2 and PCO2 to predict electron microscopy-verified intermediate or absolute ischemia-reperfusion injury was 94%. CONCLUSIONS: Monitoring of intrathecal PO2 after clamping of the descending aorta correlated with ultrastructural changes in the spinal cord in this pig model.

Animals↗

PubMed2001

Osteoprotegerin inhibits prostate cancer-induced osteoclastogenesis and prevents prostate tumor growth in the bone.

Prostate cancer (CaP) forms osteoblastic skeletal metastases with an underlying osteoclastic component. However, the importance of osteoclastogenesis in the development of CaP skeletal lesions is unknown. In the present study, we demonstrate that CaP cells directly induce osteoclastogenesis from osteoclast precursors in the absence of underlying stroma in vitro. CaP cells produced a soluble form of receptor activator of NF-kappaB ligand (RANKL), which accounted for the CaP-mediated osteoclastogenesis. To evaluate for the importance of osteoclastogenesis on CaP tumor development in vivo, CaP cells were injected both intratibially and subcutaneously in the same mice, followed by administration of the decoy receptor for RANKL, osteoprotegerin (OPG). OPG completely prevented the establishment of mixed osteolytic/osteoblastic tibial tumors, as were observed in vehicle-treated animals, but it had no effect on subcutaneous tumor growth. Consistent with the role of osteoclasts in tumor development, osteoclast numbers were elevated at the bone/tumor interface in the vehicle-treated mice compared with the normal values in the OPG-treated mice. Furthermore, OPG had no effect on CaP cell viability, proliferation, or basal apoptotic rate in vitro. These results emphasize the important role that osteoclast activity plays in the establishment of CaP skeletal metastases, including those with an osteoblastic component.

Animals↗

PubMed2000

Selective alteration of calcitonin gene related peptide in hyperthermic brain injury. An experimental study in the rat brain using immunohistochemistry.

The possibility that calcitonin gene related peptide (CGRP) participates in the pathophysiology of hyperthermic brain injury was examined in a rat model. The CGRP immunoreactivity was examined in several brain regions of control and 4 h heat stressed rats using immunohistochemistry. Subjection of animals to heat stress in a biological oxygen demand (BOD) incubator at 38 degrees C for 4 h resulted in a marked redistribution of CGRP immunoreactivity. Thus, in cerebral cortex, hippocampus, cerebellum, medulla and spinal cord the CGRP immunoreactivity was profoundly increased following heat stress. On the other hand in brain stem and pons, the CGRP activity is downregulated. These observations suggest that heat stress has the capacity to influence CGRP immunoreactivity and this redistribution of the peptide is somehow associated with the molecular mechanisms of thermal information processing system of the CNS in heat stress, not reported earlier.

Animals↗

PubMed2000

Role of nitric oxide in blood-brain barrier permeability, brain edema and cell damage following hyperthermic brain injury. An experimental study using EGB-761 and Gingkolide B pretreatment in the rat.

The role of oxidative stress in hyperthermia induced upregulation of constitutive and inducible isoforms of nitric oxide synthase (NOS) in the central nervous system (CNS) was investigated using immunohistochemistry in a rat model. Exposure of rats to heat stress at 38 degrees C for 4 h resulted in marked upregulation of constitutive NOS (cNOS) and a mild but significant expression of inducible NOS (iNOS) in several brain regions exhibiting leakage of the blood-brain barrier (BBB), brain edema formation and cell injury. Pretreatment with the potent antioxidative compound EGB-761 or its constituent, Ginkgolide B significantly attenuated upregulation of cNOS and iNOS in the brain and also reduced the BBB permeability disturbances, brain edema and cell injury. These neuroprotective effects were most marked in the EGB-761 pretreated rats. Our observations strongly suggest that (i) EGB-761 and Ginkgolide B pretreatment offer significant neuroprotection in hyperthermic brain injury, (ii) upregulation of cNOS and iNOS are injurious to the cell and, (iii) oxidative stress plays an important role in NOS expression and cell injury.

Animals↗

PubMed2000

p-Chlorophenylalanine, an inhibitor of serotonin synthesis reduces blood-brain barrier permeability, cerebral blood flow, edema formation and cell injury following trauma to the rat brain.

The role of serotonin in trauma induced alterations in blood-brain barrier (BBB) permeability, cerebral blood flow (CBF), brain edema and cell changes were examined in a new model of cortical injury in the rat using a pharmacological approach. A longitudinal incision into the right parietal cerebral cortex (about 3 mm deep and 5 mm long) was associated with a profound increase in the BBB permeability to Evans blue and [131]I-sodium, brain water content, and a reduction in the CBF in both the ipsilateral and contralateral hemispheres 5 h after trauma. Nissl staining showed a profound nerve cell reaction in the parietal cerebral cortex of both hemispheres. The intensity of these pathological changes was most pronounced in the traumatised hemisphere. Pretreatment with p-CPA, a serotonin synthesis inhibitor, significantly attenuated breakdown of the BBB permeability, brain edema and the CBF disturbances. Damaged and distorted nerve cells were markedly less frequent in p-CPA treated rats. This effect of the drug was most pronounced in the contralateral hemisphere. The observations strongly suggest that serotonin is one of the important neurochemical mediators of BBB permeability disturbances and brain edema formation in the trauma induced brain damage.

Animals↗

PubMed2000

A new antioxidant compound H-290/51 attenuates upregulation of constitutive isoform of heme oxygenase (HO-2) following trauma to the rat spinal cord.

Influence of a new antioxidant compound H-290/51 on carbon monoxide (CO) production following spinal cord injury was examined using immunohistochemistry of the constitutive isoform of heme oxygenase-2 (HO-2) in a rat model. Subjection of rats to 5 h spinal cord injury by making an incision into the right dorsal horn of the T10-11 segments resulted in upregulation of HO-2 in the injured and adjacent T9 and T12 segments. At this time, disruption of the blood-spinal cord barrier (BSCB) permeability, edema formation and cell injury were more pronounced. Pretreatment with H-290/51 (50 mg/kg, p.o., 30 min before trauma) significantly attenuated the HO-2 immunoreactivity along with breakdown of the BSCB permeability, edema and cell injury. These results for the first time demonstrate that the antioxidant compound H-290/51 is capable of attenuating HO-2 expression and thereby influencing CO production. Furthermore, our observations indicate that oxidative stress is involved in CO production, as reflected by HO-2 expression, which is injurious to the cord and H-290/51 exerts powerful neuroprotective effects in spinal cord injury.

Animals↗

PubMed2000

Spinal cord injury induced c-fos expression is reduced by p-CPA, a serotonin synthesis inhibitor. An experimental study using immunohistochemistry in the rat.

Influence of serotonin on upregulation of cellular-fos (c-fos) following a focal spinal cord injury was examined using immunohistochemistry in a rat model. Spinal cord injury was produced by making a unilateral longitudinal incision of the dorsal horn of the T10-11 segments. A focal lesion to the cord markedly upregulated c-fos immunohistochemistry at 5 h which was mainly located in the edematous regions of the cord in the injured as well as in the perifocal T9 and T12 segments. Pretreatment with p-CPA, a serotonin synthesis inhibitor, significantly attenuated the c-fos upregulation along with the edematous expansion of the cord. These results for the first time suggest that trauma induced release of serotonin and edema formation are important biological signals inducing c-fos expression.

Animals↗

PubMed2000

Topical application of brain derived neurotrophic factor influences upregulation of constitutive isoform of heme oxygenase in the spinal cord following trauma an experimental study using immunohistochemistry in the rat.

Influence of brain derived neurotrophic factor (BDNF) on carbon monoxide (CO) production following spinal cord injury was examined using expression of the constitutive isoform of the enzyme hemeoxygenase-2 (HO-2) in a rat model. A longitudinal incision of the right dorsal horn on the T10-11 segment markedly increased the HO-2 immunostaining in the cord at 5 h. At this time period, breakdown of the blood-spinal cord barrier (BSCB) and edema formation were quite prominent. Repeated topical application of BDNF (20 microliters of a 1 microgram/ml solution) over the exposed surface of the cord significantly attenuated the edematous expansion of the cord and the disturbances in the BSCB permeability. In BDNF-treated rats, expression of HO-2 immunoreactivity was considerably reduced. These results strongly suggest that BDNF is neuroprotective in spinal trauma and this growth factor has the capacity to attenuate CO production by downregulating HO-2 expression.

Animals↗