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Biomedical subjects

T Lundeberg

Publications and source records attributed to T Lundeberg.

At least 19 recordsLinked to original sources
PubMed2006

Effect of defocused CO2 laser on equine tissue perfusion.

Treatment with defocused CO2 laser can have a therapeutic effect on equine injuries, but the mechanisms involved are unclear. A recent study has shown that laser causes an increase in equine superficial tissue temperature, which may result in an increase in blood perfusion and a stimulating effect on tissue regeneration. However, no studies have described the effects on equine tissue perfusion. The aim of the present study was to investigate the effect of defocused CO2 laser on blood perfusion and to correlate it with temperature in skin and underlying muscle in anaesthetized horses. Differences between clipped and unclipped haircoat were also assessed. Eight horses and two controls received CO2 laser treatment (91 J/cm2) in a randomised order, on a clipped and unclipped area of the hamstring muscles, respectively. The significant increase in clipped skin perfusion and temperature was on average 146.3 +/- 33.4 perfusion units (334%) and 5.5 +/- 1.5 degrees C, respectively. The significant increase in perfusion and temperature in unclipped skin were 80.6 +/- 20.4 perfusion units (264%) and 4.8 +/- 1.4 degrees C. No significant changes were seen in muscle perfusion or temperature. In conclusion, treatment with defocused CO2 laser causes a significant increase in skin perfusion, which is correlated to an increase in skin temperature.

Animals↗
PubMed2005

Differentiation of normal and cancer cells induced by sulfhydryl reduction: biochemical and molecular mechanisms.

We examined the morphological, biochemical and molecular outcome of a nonspecific sulfhydryl reduction in cells, obtained by supplementation of N-acetyl-L-cysteine (NAC) in a 0.1-10 mM concentration range. In human normal primary keratinocytes and in colon and ovary carcinoma cells we obtained evidences for: (i) a dose-dependent inhibition of proliferation without toxicity or apoptosis; (ii) a transition from a proliferative mesenchymal morphology to cell-specific differentiated structures; (iii) a noticeable increase in cell-cell and cell-substratum junctions; (iv) a relocation of the oncogenic beta-catenin at the cell-cell junctions; (v) inhibition of microtubules aggregation; (vi) upregulation of differentiation-related genes including p53, heat shock protein 27 gene, N-myc downstream-regulated gene 1, E-cadherin, and downregulation of cyclooxygenase-2; (vii) inhibition of c-Src tyrosine kinase. In conclusion, a thiol reduction devoid of toxicity as that operated by NAC apparently leads to terminal differentiation of normal and cancer cells through a pleiade of converging mechanisms, many of which are targets of the recently developed differentiation therapy.

Acetylcysteine↗
PubMed2005

Quality of sleep in individuals with spinal cord injury: a comparison between patients with and without pain.

STUDY DESIGN: A cross-sectional descriptive study of self-reported quality of sleep in individuals with a spinal cord injury (SCI). OBJECTIVES: To assess and describe subjective quality of sleep in patients with SCI, with and without pain. SETTING: Spinalis SCI unit, Stockholm, Sweden. METHODS: A total of 230 patients with an SCI were mailed a questionnaire containing queries about pain intensities, pain unpleasantness, mood, and sleep quality (Basic Nordic Sleep Questionnaire) to assess quality of sleep in patients with SCI with and without pain. RESULTS: Of the 192 questionnaires that were returned (response rate 83.4%), 191 were analysed. Patients were divided into three groups: (1) those who reported no pain (n=50), (2) those who reported intermittent pain (n=42), and (3) those who suffered from continuous pain (n=99). Patients suffering from continuous pain rated pain intensity and unpleasantness significantly higher than those who only suffered from intermittent pain. The group with continuous pain also reported the poorest quality of sleep and the highest ratings of anxiety and depression of the three groups. Anxiety, together with pain intensity and depression, were the main predictors for poor sleep quality. CONCLUSIONS: Poor subjective sleep quality was associated with higher ratings of pain intensity, anxiety, and depression. It is possible that melatonin serves as a modulator of these different aspects.

Activities of Daily Living↗
PubMed2005

Effect of exercise on ovarian morphology and expression of nerve growth factor and alpha(1)- and beta(2)-adrenergic receptors in rats with steroid-induced polycystic ovaries.

Oestadiol valerate (EV)-induced polycystic ovaries (PCO) in rats cause anovulation and cystic ovarian morphology. Denervation of ovarian sympathetic nerves restores ovulatory disruption. In the present study, we determined whether 5 weeks of voluntary exercise influence ovarian morphology and the expression of sympathetic markers in the EV-induced PCO rat model. The effect of exercise on (i) ovarian morphology; (ii) mRNA and protein expression of nerve growth factor (NGF); and (iii) mRNA and number of ovarian-expressing cells for the NGF receptor (p75 neurotrophin receptor) and the alpha(1a)-, alpha(1b)-, alpha(1d)- and beta(2)-adrenergic receptors (ARs) in rats with EV-induced PCO was evaluated. PCO was induced by a single i.m. injection of EV, and controls were injected with oil alone in adult cycling rats. The rats were divided into four groups: (i) control (oil); (ii) exercise group (oil + exercise); (iii) a PCO group (EV); and (iv) a PCO exercise group (EV + exercise). The exercise and PCO exercise groups ran voluntarily for 5 weeks in computer-monitored wheels placed in the cages where they were housed. The results obtained indicated that ovarian morphology was almost normalised in the PCO exercise group; NGF mRNA and protein concentrations were normalised in the PCO exercise group; high numbers of NGF receptor expressing cells in PCO ovaries were lowered by exercise; and the number of immunopositive cells of the different AR subtypes were all reduced after exercise in the PCO group, except for the alpha(1b)- and beta(2)-AR whereas the mRNA levels were unaffected, indicating transcriptional regulation. In conclusion, our data indicate a beneficial effect of regular exercise, as a modulator of ovarian sympathetic innervation, in the prevention and treatment of human PCOS.

Animals↗
PubMed2005

Diffusely increased bone scintigraphic uptake in patellofemoral pain syndrome.

OBJECTIVES: Painful disorders of the patellofemoral joint are one of the most frequent complaints in orthopaedic and sports medicine. The aims of this study were to determine whether bone scintigrams of patients suffering from patellofemoral pain syndrome (PFPS) show diffuse uptake and in what bony compartment of the knee uptake, if any, was localised. METHODS: Fifty eight patients with chronic PFPS were examined. All patients underwent a detailed clinical history and a thorough physical examination of the knee. Anterior and lateral static images of both knees were made using a gamma camera 3 h after injection of 550 MBq of (99m)Tc-HMDP. Two experienced radiologists visually evaluated the scans blindly and separately. As 51 patients had bilateral pain, 109 painful knees are included in the results. RESULTS: Diffuse uptake on bone scintigrams was found in 48 knees in 30 of the patients. In 33 knees the uptake was localised to only one bone compartment, in 10 knees diffuse uptake was found in two of the bones forming the knee joint, and in six knees all three bone compartments (the distal femur, the patella, and the proximal tibia) exhibited diffuse uptake. CONCLUSIONS: Scintigrams of approximately half of the patients with PFPS will show diffuse uptake in one or more of the bony compartments of the knee joint and radioactive tracer accumulation will occur as often in the proximal tibia as in the patella.

Adult↗
PubMed2004

Production and characterization of antibodies for the specific determination of the opioid peptide Met5-Enkephalin-Arg6-Phe7.

Endogenous opioids serve as modulators of neuroendocrine and immune system processes, the investigation of which calls for high-specificity radioimmunoassays (RIAs). This study focuses on the development and use of a specific radioimmunoassay for the opioid peptide Met5-Enkephalin-Arg6-Phe7 (MEAP), the C-terminus part of proenkephalin A. Antibodies were raised in four rabbits and investigated in terms of titre, avidity and specificity, followed by finding ideal conditions for these antibodies in RIA. MEAP concentrations were determined in crude extracts of rat hypothalamus, dorsal root ganglia, adrenals and ankle using this standardized assay after an oxidizing process. At reverse-phase high-pressure liquid chromatography (HPLC), the position of immunoreactive material from rat hypothalamus eluted as two peaks out of which one was compatible with that of synthetic MEAP. All rabbits exhibited individual differences in relative immune response and time of its onset. The avidity constant was 10 times higher on a molar basis for ab 4108 compared with ab 4182. There was no cross-reactivity for ab 4182 to related peptides, such as enkephalins and dynorphin B, and negligible background values for ab 4108. The relative levels ofimmunoreactive MEAP from the CNS versus peripheral tissues contrasted in accordance with current knowledge. It is suggested that reports with RIA results should include characterization of antibodies, extraction procedures, standard curves and compositions of buffers. Furthermore, the results should preferably be expressed in relation to total protein content.

Animals↗
PubMed2003

Antinociceptive effect of calcitonin gene-related peptide in the central nucleus of amygdala: activating opioid receptors through amygdala-periaqueductal gray pathway.

The central nucleus of amygdala (CeA) plays an important role in pain regulation. Calcitonin gene-related peptide (CGRP)-like immunoreactive fibers and CGRP receptors are distributed densely in CeA. The present study was performed to elucidate the role of CGRP in nociceptive regulation in the CeA of rats. Intra-CeA injection of CGRP induced dose-dependent increases in the hind-paw withdrawal latency tested by hotplate test and Randall Selitto Test, indicating an antinociceptive effect of CGRP in CeA. Furthermore, the antinociceptive effect of CGRP was blocked by intra-CeA administration of the CGRP receptor antagonist CGRP8-37, suggesting that CGRP receptor1 is involved in the CGRP-induced antinociception. The CGRP-induced antinociception was attenuated by s.c. injection of the opioid antagonist naloxone, suggesting an involvement of endogenous opioid systems in CGRP-induced antinociception. Moreover, it was demonstrated that opioid receptors in the periaqueductal gray, but not in CeA, contributed to the CGRP-induced antinociception, indicating the importance of the pathway between CeA and the periaqueductal gray in CGRP-induced antinociception. Combining retrograde fluorescent tracing with immunohistochemistry, we found that met-enkephalinergic neurons were innervated by CGRP-containing terminals in CeA. Furthermore, most neurons in the CeA retrogradely traced from the periaqueductal gray were contacted by CGRP-containing terminals and some of them were surrounded by characteristic basket-like structures formed by the terminals, suggesting that CGRP innervates the neurons which project from CeA to the periaqueductal gray. The results indicate that CGRP activates the met-enkephalinergic neurons, which project from CeA to the periaqueductal gray, producing antinociceptive effect in rats.

Amygdala↗
PubMed2003

Gender related differences in pain in spinal cord injured individuals.

STUDY DESIGN: Out of a population of 456 patients with spinal cord injuries (SCI), 130 having pain were selected after matching, based on gender, age, American Spinal Injury Association (ASIA) impairment grade and level of lesion. OBJECTIVE: To investigate whether gender differences with regard to pain perception and prevalence exist in a population of patients following spinal cord injury. SETTING: Spinalis SCI Unit (out-patient clinic), Stockholm, Sweden. METHOD: 130 patients suffering from pain were assessed over a 12-month period in a yearly health control. RESULTS: SCI women had a higher prevalence of nociceptive pain than men and their use of analgesics was greater. However, no differences between the sexes could be seen regarding pain and localization, onset, distribution, factors affecting pain, number of painful body regions, pain descriptors, ratings of pain intensities or in pain and life satisfaction. CONCLUSION: This study showed that SCI men and women describe their pain very similarly. However, SCI women had a higher prevalence of nociceptive pain than men and their use of opiates and non-steroid anti-inflammatory drugs (NSAIDs) was greater.

Adolescent↗
PubMed2002

Pain--from periphery to brain.

Pain is not simply due to the activation of peripheral nociceptors but to multiple factors. Part of the article is a review of scientific work on such factors at the different levels of the peripheral and central nervous system, with particular reference to possible new therapy strategies. A second part describes some aspects of clinical assessment of persistent pain conditions, such as differential diagnostics between musculoskeletal nociceptive and neurogenic pain, between referred pain from a musculoskeletal focus and projected neurogenic pain, and between psychogenic pain and pain with a somatic cause.

Afferent Pathways↗
PubMed2002

Arterial blood flow and microcirculatory changes in a rat groin flap after thrombosis induced by electrical stimulation of the artery.

An experimental model of acute arterial thrombosis was developed in a rat groin flap model. Electrical stimulation was delivered to the flap artery while measuring blood flow in the artery and in the flap microcirculation using a laser Doppler system. Electrical stimulation produced an occlusive thrombosis in 10 rats within 68.1 +/- 19.26 (mean +/- SE) min. Thrombosis formation produced a rapid decrease of the LDF readings in the artery (90%) and in the flap (70%), the decrease being fairly parallel. Following the spontaneous thrombolysis, the artery perfusion recovered to baseline level but the flap blood flow only recovered by 10-20%. During electrical stimulation there was no change of the systemic blood pressure. The dynamic course of thrombus formation was documented on a videotape recorder through a microscope-mounted video camera and monitored on a television screen. Segments of the artery were obtained during and at the end of the experiments. The histological examination revealed arterial thrombosis composed of red blood cells, fibrin, and white blood cells, without any significant architectural and endothelial changes in the vessel walls. The study suggests that this model using electric vessel stimulation is effective for inducing arterial thrombosis and provides a simple method for recording the dynamic course of thrombus formation.

Animals↗
PubMed2002

Role of cholecystokinin-8 in nerve growth factor and nerve growth factor mRNA expression in carrageenan-induced joint inflammation in adult rats.

OBJECTIVES: The aim of our study was to investigate the role of cholecystokinin-8 (CCK-8), which is able to induce the synthesis of nerve growth factor (NGF), in the joint inflammation of carrageenan-injected rats. METHODS: Adult rats were injected in the ankle joint with carrageenan, with or without CCK-8 or a CCK receptor antagonist (proglumide), and tissue swelling, NGF levels and NGF mRNA expression were assessed. RESULTS: Expression of NGF and NGF mRNA increased transiently after carrageenan injection. This effect was not altered by CCK-8 injection but was inhibited by the CCK receptor antagonist. The decrease in NGF level after treatment with the antagonist was concurrent with an increase in paw swelling. CONCLUSIONS: The results demonstrate that, whereas CCK-8 has no anti-inflammatory action in carrageenan-injected animals, proglumide induces a worsening of inflammation and reduces the expression of both NGF and NGF mRNA in inflamed ankle joints. Our data point to a regulatory action of CCK-8 on NGF synthesis during acute synovitis and suggest a role for NGF in the healing phase of inflammation.

Animals↗
PubMed2002

Cholecystokinin-8 and nerve growth factor: two endogenous molecules working for the upkeep and repair of the nervous system.

Cholecystokinin-8 (CCK-8), the small peptide initially described as a gastric factor involved in the regulation of feeding behavior, is today recognized as one of the most abundant neurotransmitters/ neuropeptides in brain and is an important signal factor for the peripheral and central nervous systems. In the past twenty years, many studies have focused on possible clinical applications of this peptide and its receptor ligands in psychiatric diseases and gastrointestinal pathologies. Recently it has been suggested that CCK-8 may also have a neuroprotective role, thus opening a new field of interest around the physiology and the pharmacology of this neuropeptide and its receptors. It has been demonstrated that CCK-8 counteracts neuronal deficit following chemical or surgical lesions in both the central and peripheral nervous systems and that Nerve Growth factor (NGF) is involved in the CCK-induced recovery process. By using selective CCK receptor antagonists it has been demonstrated that CCK-8, when injected intraperitoneally, has the ability to stimulate NGF synthesis in brain and peripheral organs by a mechanism that involves the activation of CCK receptors. As has been widely reported, NGF is an essential survival and differentiative factor for selective neuronal populations of the PNS and CNS and plays a role in the events of degeneration and repair of the nervous system in diseases with different etiologies, e.g. neurodegenerative and autoimmune diseases as well as diabetes-associated pathologies. The possibility of using NGF in therapy has been evaluated and systemic and intracerebral NGF treatment have been tested in patients and animal models. Although the results of these studies are encouraging, the difficulty to predict and/or eliminate the side effects of NGF/NGF antibody treatment has made it difficult to fully evaluate the potential of the beneficial effects. In this context recent results obtained in our laboratories may offer a new prospective for the pharmacological approaches to the diseases associated with altered NGF production and functions. The data of our recent observations on NGF and CCK-8 is covered in this review.

Animals↗
PubMed2001

Nociceptin/orphanin FQ into the rat periaqueductal gray decreases the withdrawal latency to heat and loading, an effect reversed by (Nphe(1))nociceptin(1-13)NH(2).

The present study investigated the effect of intraperiaqueductal grey injection of nociceptin/orphanin FQ (N/OFQ) and an antagonist (Nphe(1))nociceptin(1-13)NH(2) on the hindpaw withdrawal response to thermal and mechanical stimulation in rats. N/OFQ (5 nmol) significantly decreased the nociceptive thresholds in both tests and 1, 5 and 10 nmol of (Nphe(1))nociceptin(1-13)NH(2) significantly reversed this effect in a dose dependent way. Our results demonstrate, that N/OFQ has a nociceptive action, possibly through inhibition of PAG neurons. This effect is blocked by the antagonist (Nphe(1))nociceptin(1-13)NH(2) probably via ORL1 receptors in the periaqueductal grey.

Animals↗
PubMed2001

The effect of galanin on wide-dynamic range neuron activity in the spinal dorsal horn of rats.

The present study investigated the effect of galanin on wide-dynamic range (WDR) neuron activity in the dorsal horn of the spinal cord of rats. The evoked discharge of WDR neurons was elicited by transdermic electrical stimulation applied on the ipsilateral hindpaw of rats. Galanin was administered directly on the spinal dorsal surface of L3-L5. The evoked discharge frequency of the WDR neurons decreased significantly after the administration of galanin and the effect lasted for more than 30 min. Furthermore, the inhibitory effect of galanin on the evoked discharge frequency of WDR neurons was blocked by following administration of the galanin antagonist galantide, indicating that the inhibitory effect of galanin on the activity of WDR neurons was induced by activating galanin receptors in the dorsal horn of the spinal cord. The results suggest that galanin has an inhibitory role in the transmission of presumed nociceptive information in the dorsal horn of the spinal cord in rats.

Animals↗
PubMed2001

Cholecystokinin-8 promotes recovery of sympathectomy induced by 6-hydroxydopamine in adult mice.

We used an experimental model of sympathetic neuropathy to investigate the effects of intraperitoneal cholecystokinin-8 (CCK-8) administration on the recovery of injured peripheral neurones. After treatment of adult mice with 6-hydroxydopamine (6-OHDA), which known to induce peripheral sympathectomy, nerve growth factor (NGF) in peripheral tissue first increased and then rapidly decreased to baseline levels. Following this observation, sympathectomised mice were treated with CCK-8 starting when the NGF levels lowered toward the control value. Our results show that injections with 8 nmol/kg of CCK-8 promote not only recovery of noradrenergic innervation but also NGF and neuropeptide Y (NPY) synthesis in peripheral tissue. This latter observation suggests that the effect of CCK-8 might be mediated through the stimulation of NGF synthesis.

Animals↗
PubMed2001

Involvement of CGRP and CGRP1 receptor in nociception in the nucleus accumbens of rats.

The present study was performed to investigate the role of calcitonin gene-related peptide (CGRP) and its antagonist CGRP8-37 on nociception in the nucleus accumbens of rats. Hindpaw withdrawal latencies (HWLs) to noxious stimulation induced by hot plate and Randall Selitto tests were measured. The HWL to both thermal and mechanical stimulation increased significantly after intra-nucleus accumbens administration of 0.5 or 1 nmol of CGRP, but not 0.1 nmol, indicating that CGRP plays an anti-nociceptive effect in the nucleus accumbens of rats. The anti-nociceptive effect induced by intra-nucleus accumbens administration of 1 nmol of CGRP was blocked significantly by following intra-nucleus accumbens administration of 1 nmol of CGRP8-37, a selective antagonist of CGRP1 receptor. Furthermore, the HWLs to both thermal and mechanical stimulation decreased significantly after intra-nucleus accumbens administration of 0.02, 0.1 and 0.5 nmol of CGRP8-37 alone. The hyperalgesic effect of intra-nucleus accumbens administration of CGRP8-37 lasted for more than 60 min after the injection, suggesting that CGRP1 receptor is involved in anti-nociception in the nucleus accumbens of rats. The results indicate that CGRP and CGRP1 receptor have important roles in nociceptive modulation in the nucleus accumbens of rats.

Animals↗
PubMed2001

Anti-nociceptive effect of neuropeptide Y in periaqueductal grey in rats with inflammation.

Experimental inflammation was induced by subcutaneous injection of carrageenan into the left hindpaw of rats. Intra-periaqueductal grey (PAG) injection of 0.02 or 0.1 nmol of neuropeptide Y (NPY), but not 0.004 nmol, induced significant increases in hindpaw withdrawal latency (HWL) to thermal and mechanical stimulation in rats with inflammation. Furthermore, the anti-nociceptive effect of NPY was blocked partly by following intra-PAG injection of the Y1 receptor antagonist NPY28-36. The results demonstrated that NPY plays an anti-nociceptive role in PAG in rats with inflammation, in which Y1 receptor is involved.

Animals↗