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Biomedical subjects

E Eriksson

Publications and source records attributed to E Eriksson.

At least 91 records · Page 5Linked to original sources

Both dopamine and the putative dopamine D3 receptor antagonist PNU-99194A induce a biphasic inhibition of phorbol ester-stimulated arachidonic acid release from CHO cells transfected with the dopamine D3 receptor.

In Chinese hamster ovary (CHO) cells transfected with the cDNA for the dopamine D3 receptor, low concentrations of dopamine (IC50: 0.5 nM) counteracted the release of arachidonic acid (AA) induced by the protein kinase C activator TPA (maximal inhibition: 15% at 10 - 30 nM). The effect of dopamine -- which was antagonized by pretreatment with pertussis toxin (PTX) or by the dopamine receptor antagonist haloperidol -- was biphasic; thus, at increasing concentrations of dopamine (100 nM - 1 microM), AA levels approached baseline. The preferential dopamine D3 receptor ligand PNU-99194A displayed an effect similar to that of dopamine; thus, whereas low concentrations of PNU-99194A (IC50: 1.9 nM) reduced TPA-induced AA release (maximal inhibition: 15% at 30 - 100 nM), higher concentrations (> or =1 microM) were ineffective. When dopamine and PNU-99194A were administered together at concentrations yielding maximal inhibition of AA release, no additive effect was observed; moreover, a high concentration of dopamine counteracted the AA-reducing effect of a low concentration of PNU-99194A and vice versa. It is suggested that D3 receptors in transfected CHO cells may exert mainly an inhibitory, but also a stimulatory influence on TPA-induced AA release, and that PNU-99194A acts as an agonist in this system.

Animals↗

Effects of mCPP on the extracellular concentrations of serotonin and dopamine in rat brain.

Intravenous administration of m-chloro-phenylpiperazine (mCPP) (0.25 or 2.5 mg/kg) induced a marked and dose-related increase in extracellular concentrations of serotonin in hippocampus (300-1,400% of baseline) as measured using in vivo microdialysis in awake male Wistar rats of the spontaneously hypertensive (SH) strain. Indicating that the effect of mCPP was caused by a reversal of the serotonin transporter, it was antagonized by pretreatment with the serotonin re-uptake inhibitor citalopram (10 mg/kg) but was unaffected by local administration of the sodium channel blocker tetrodotoxin (TTX; 1 microns). mCPP was also shown to induce an increase in extracellular concentrations of dopamine in the nucleus accumbens and the striatum of SH rats and in the nucleus accumbens of rats of the Sprague-Dawley (SD) strain; this effect of mCPP was, however, much weaker (125-170% of baseline) than the effect on serotonin; moreover, it seems to be TTX-sensitive. In anesthetized SD rats, mCPP induced a moderate reduction of nigral dopamine cell firing rate; supporting the assumption that this effect is secondary to the observed increase in dopamine release, it was blocked by pretreatment either with the dopamine synthesis inhibitor alpha-methyl-para-tyrosine or with the dopamine D2 receptor antagonist haloperidol. In conclusion, the results suggest that mCPP induces a marked, TTX-insensitive increase in serotonin release in rat brain, but only a modest and TTX-sensitive increase in the extracellular levels of dopamine.

Animals↗

Prevalence of APC resistance and its relationship to arterial and venous thromboembolism in a general population sample of elderly Swedish men: The Study of Men Born in 1913.

BACKGROUND: Most studies of hereditary resistance to activated protein C (APC resistance) as a risk factor for venous thromboembolism are derived from case-control studies of hospitalized patients, whilst the importance of this condition in the general population has been only sparsely investigated. OBJECTIVE: To study the prevalence of APC resistance and its relationship to morbidity and mortality in a general population sample of elderly men. DESIGN: Cross-sectional and prospective follow-up study. SETTING: General community: The Study of Men Born in 1913. SUBJECTS: A random population sample of 404 men, all 75 years of age. MAIN OUTCOME MEASURES: Four hundred and four men participated in a screening examination in 1988. The APC ratio was analysed in 382 of them. All the men were followed up for 5 years. Medical records were reviewed for all the men with a history of deep vein thrombosis, pulmonary embolism, myocardial infarction or stroke. RESULTS: Twenty-five men (6.5%) were found to have APC resistance. The incidence of venous thromboembolism, myocardial infarction or stroke did not differ between men with or without APC resistance, either retrospectively or during follow-up. Only two men experienced a deep vein thrombosis before the age of 80 and there was no case of pulmonary embolism. Mortality during 5 years of follow-up did not differ between men with and without APC resistance. CONCLUSION: The prevalence of APC resistance was 6.5% in this study of Swedish men. Although the size of the population sample is somewhat small, the study shows that, amongst elderly men, the association between APC resistance and venous thromboembolic disease was weak and men with this hereditary condition did not have any increase in morbidity or mortality compared with men without APC resistance.

Aged↗

Is premenstrual dysphoric disorder a distinct clinical entity?

Does the evidence now available support the concept of premenstrual dysphoric disorder (PMDD) as a distinct clinical disorder such that the relative safety and efficacy of potential treatment can be evaluated? In a roundtable discussion of this question, a wealth of information was reviewed by a panel of experts. The key characteristics of PMDD, with clear onset and offset of symptoms closely linked to the menstrual cycle and the prominence of symptoms of anger, irritability, and internal tension, were contrasted with those of known mood and anxiety disorders. PMDD displays a distinct clinical picture that, in the absence of treatment, is remarkably stable from cycle to cycle and over time. Effective treatment of PMDD can be accomplished with serotinergic agents. At least 60% of patients respond to selective serotonin reuptake inhibitors (SSRIs). In comparison with other disorders, PMDD symptoms respond to low doses of SSRIs and to intermittent dosing. Normal functioning of the hypothalamic-pituitary-adrenal (HPA) axis, biologic characteristics generally related to the serotonin system, and a genetic component unrelated to major depression are further features of PMDD that separate it from other affective (mood) disorders. Based on this evidence, the consensus of the group was that PMDD is a distinct clinical entity. Potential treatments for this disorder can now be evaluated on this basis to meet the clear need for effective therapy.

Comorbidity↗

Effect of buspirone on sexual dysfunction in depressed patients treated with selective serotonin reuptake inhibitors.

To evaluate the possible influence of buspirone on sexual dysfunction in depressed patients treated with a selective serotonin reuptake inhibitor (SSRI), we analyzed data from a placebo-controlled trial designed to explore the efficacy of buspirone as add-on treatment for patients not responding to an SSRI alone. At baseline, all patients met the criteria for a major depressive episode according to DSM-IV and had received citalopram or paroxetine during a minimum of 4 weeks without responding to the treatment. Buspirone (flexible dosage, 20-60 mg/day) or placebo was added to the SSRI for 4 weeks; the mean daily dose of buspirone at endpoint was 48.5 mg (SD = 1.0). Sexual dysfunction was evaluated using a structured interview. Before starting medication with buspirone or placebo, 40% (47 of 117) reported at least one kind of sexual dysfunction (decreased libido, ejaculatory dysfunction, orgasmic dysfunction). During the 4 weeks of treatment, approximately 58% of subjects treated with buspirone reported an improvement with respect to sexual function; in the placebo group, the response rate was 30%. The difference between placebo and active drug treatment was more pronounced in women than in men. The response was obvious during the first week, with no further improvement during the course of the study. It is suggested that the effect of buspirone on sexual dysfunction is a result of a reversal of SSRI-induced sexual side effects rather than of an antidepressant effect of the drug.

Anti-Anxiety Agents↗

Prelaminated free flap reconstruction of complex central facial defects.

This article is a review of five patients who underwent reconstruction of nasal and paranasal facial defects with prelaminated forearm free flaps. The defects resulted from thermal injury, gunshot wound, excision of tumor, and arteriovenous malformation (n = 2). The forearm flaps were based on the radial artery (n = 4) and ulnar artery (n = 1) and were prelaminated with grafts of skin and cartilage. All flaps were successfully transferred to the face, but revisions were needed to separate the subunits and improve appearance. A prelaminated free flap should be considered for a patient requiring reconstruction of a complex central facial defect.

Adult↗

Dermatan sulfate activates nuclear factor-kappab and induces endothelial and circulating intercellular adhesion molecule-1.

Proteoglycans (PGs) can influence cell behaviors through binding events mediated by their glycosaminoglycan (GAG) chains. This report demonstrates that chondroitin sulfate B, also known as dermatan sulfate (DS), a major GAG released during the inflammatory phase of wound repair, directly activates cells at the physiologic concentrations of DS found in wounds. Cultured human dermal microvascular endothelial cells exposed to DS responded with rapid nuclear translocation of nuclear factor-kappaB (NF-kappaB), increased expression of intercellular adhesion molecule-1 (ICAM-1) mRNA, and increased ICAM-1 cell surface protein. Heparan sulfate and chondroitin sulfates A and C had no effect on activation of NF-kappaB or induction of ICAM-1. Inhibition of NF-kappaB activation blocked the effect of DS. The increase in cell surface ICAM-1 did not involve TNF-alpha or IL-1 release by endothelial cells, but it was facilitated by autocrine factors whose release was initiated by DS. The ICAM-1-inductive activity of DS was confirmed in vivo. Injection of DS, but not heparin or other chondroitin sulfates, into mice greatly increased circulating levels of soluble ICAM. These data provide evidence that DS, but not other GAGs, initiates a previously unrecognized cell signaling event that can act during the response to injury.

Animals↗

Serotonin reuptake inhibitors for the treatment of premenstrual dysphoria.

Premenstrual dysphoria (PMD) is a severe form of premenstrual syndrome, afflicting approximately 5% of all women of fertile age. The cardinal symptoms are irritability and anger. In addition, sadness, tension and carbohydrate craving are common complaints. The symptoms surface regularly between ovulation and menstruation, and disappear completely within a few days after the onset of the bleeding; in patients with remaining symptoms during the follicular phase, alternative diagnoses should be considered. In a large number of recent trials, serotonin reuptake inhibitors (clomipramine, citalopram, fluoxetine, paroxetine, sertraline) have been shown to reduce the symptoms of PMD much more effectively than placebo; in contrast, non-serotonergic antidepressants (maprotiline, bupropion) appear to be ineffective. Interestingly, the onset of action of clomipramine and selective serotonin reuptake inhibitors (SSRIs) is much shorter when used for PMD than when used for depression, panic disorder, or obsessive-compulsive disorder. Consequently, patients with PMD can restrict the medication to the luteal phase of the cycle. In a recent placebo-controlled trial, intermittent administration of the SSRI citalopram was shown to reduce the symptoms of PMD significantly better than placebo, but also better than continuous administration of the drug. A reasonable interpretation of the latter, unexpected finding is that continuous medication may be associated with a certain development of tolerance than can be avoided by intermittent drug administration. The observation that the symptoms of PMD may be effectively reduced by SSRIs is of considerable clinical importance since previously no effective treatment for this common condition - apart from those disrupting ovarian cyclicity - has been available. It is also of theoretical importance because it constitutes one of the first pharmacological observations supporting the concept that serotonin may dampen irritability and anger in humans.

Adult↗

Dermatan sulfate released after injury is a potent promoter of fibroblast growth factor-2 function.

Proteoglycans have been shown in vitro to bind multiple components of the cellular microenvironment that function during wound healing. To study the composition and function of these molecules when derived from an in vivo source, soluble proteoglycans released into human wound fluid were characterized and evaluated for influence on fibroblast growth factor-2 activity. Immunoblot analysis of wound fluid revealed the presence of syndecan-1, syndecan-4, glypican, decorin, perlecan, and versican. Sulfated glycosaminoglycan concentrations ranged from 15 to 65 microgram/ml, and treatment with chondroitinase B showed that a large proportion of the glycosaminoglycan was dermatan sulfate. The total glycosaminoglycan mixture present in wound fluid supported the ability of fibroblast growth factor-2 to signal cell proliferation. Dermatan sulfate, and not heparan sulfate, was the major contributor to this activity, and dermatan sulfate bound FGF-2 with Kd = 2.48 microM. These data demonstrate that proteoglycans released during wound repair are functionally active and provide the first evidence that dermatan sulfate is a potent mediator of fibroblast growth factor-2 responsiveness.

Body Fluids↗

Parathyroid hormone-related protein in patients with primary breast cancer and eucalcemia.

Parathyroid hormone-related protein (PTHrP) is a causative factor of humoral hypercalcemia in breast cancer and other malignancies. We studied circulating PTHrP levels with three different immunoassays directed against different parts of the PTHrP molecule in 48 patients with breast cancer and eucalcemia. The methods used were: (a) a RIA with antibodies directed toward the midregion (63-78); (b) an immunofluorometric assay with two antibodies against 1-34 and 38-67; and (c) an immunoradiometric assay with antibodies against 1-40 and 1-72. Although most patients had PTHrP levels indistinguishable from normal when measured by all three methods, four patients had increased serum levels in the IFMA. PTHrP was detected by immunohistochemistry in tumors from nearly all patients. One patient with elevated PTHrP in plasma measured by IFMA showed intense staining of tumor by immunohistochemistry; the tumor was histologically graded as III (severe) and was the largest of all tumors in this patient group. The IFMA can identify increased serum PTHrP in some patients with breast cancer who are not hypercalcemic. This assay may be especially useful in screening patients for this tumor during a relative early phase of the disease.

Adult↗

Tetracycline repressor, tetR, rather than the tetR-mammalian cell transcription factor fusion derivatives, regulates inducible gene expression in mammalian cells.

This article describes the first (to our knowledge) tetracycline-inducible regulatory system that demonstrates that the tetracycline repressor (tetR) alone, rather than tetR-mammalian cell transcription factor fusion derivatives, can function as a potent trans-modulator to regulate gene expression in mammalian cells. With proper positioning of tetracycline operators downstream of the TATA element and of human epidermal growth factor (hEGF) as a reporter, we show that gene expression from the tetracycline operator-bearing hCMV major immediate-early enhancer-promoter (pcmvtetO) can be regulated by tetR over three orders of magnitude in response to tetracycline when (1) the reporter was cotransfected with tetR-expressing plasmid in transient expression assays, and (2) the reporter unit was stably integrated into the chromosome of a tetR-expressing cell line. This level of tetR-mediated inducible gene regulation is significantly higher than that of other repression-based mammalian cell transcription switch systems. In an in vivo porcine wound model, close to 60-fold tetR-mediated regulatory effects were detected and it was reversed when tetracycline was administered. Collectively, this study provides a direct implementation of this tetracycline-inducible regulatory switch for controlling gene expression in vitro, in vivo, and in gene therapy.

Animals↗

Testosterone as a biological marker in psychopathy and alcoholism.

The aim of the present study was to clarify the relationships between testosterone and alcohol abuse, alcohol dependence and specific personality characteristics and behaviors in a forensic psychiatric population. Serum levels of total testosterone (TT), free testosterone (FT-DPC) and sex hormone-binding globulin (SHBG) were determined in 61 male subjects undergoing forensic psychiatric examinations. All subjects had been detoxified from drugs and alcohol during previous incarceration in jail or hospital. TT and FT-DPC were found to be highly correlated (r=0.63, P < 0.0001). High concentrations of TT and SHBG were consistently related to type II alcoholism, but not pure alcohol dependence. TT and SHBG were also related to antisocial personality disorder. Furthermore, TT and SHBG were related to socially deviant behavior, reflected in factor 2 in the Psychopathy Checklist (PCL-R). In a multiple regression, FT-DPC was also clearly associated with the psychopathy-related scales of the Karolinska Scales of Personality (KSP) when age and signs of hepatic damage were kept under control.

Adult↗

Imprinting of female offspring with testosterone results in insulin resistance and changes in body fat distribution at adult age in rats.

In women, a relative hyperandrogenicity is statistically associated with insulin resistance and centralization of body fat, which are predictors for the development of non-insulin-dependent diabetes mellitus. The aim of this study was to evaluate the effect of androgenization of newborn female rats on insulin sensitivity at adult age. To mimic the neonatal androgen peak normally observed in male rats, female pups were administered one high dose of testosterone (T) subcutaneously within 3 h after birth. They were then given back to their mothers and followed to adult age. At the end of the week 9, tail samples were taken, showing no differences in fasting plasma concentrations of glucose, lactate, insulin, or free fatty acids between T-treated rats and controls. Plasma concentrations of T and progesterone were significantly lower in the T-treated rats, whereas no differences were found in the levels of corticosterone, estradiol, insulin-like growth factor I, or ACTH. After 10 wk, insulin sensitivity was studied with hyperglycemic and euglycemic hyperinsulinemic (5 mU insulin/kg/min) clamp techniques. The T-treated rats showed insulin resistance with both techniques, which was overcome with time and increasing insulin concentrations during the clamp measurements. The T-treated rats were also heavier and had increased relative weights of skeletal muscles and the spleen. Parametrial, retroperitoneal, and inguinal adipose tissues decreased in weight while mesenteric adipose tissue tended to increase, resulting in an approximately 30-50% larger mesenteric than other adipose tissues. It is concluded that neonatal T imprinting of female rats is followed by insulin resistance, changes in adipose tissue distribution, and an enlarged lean mass, without elevation of circulating T. Similar changes are seen in adult female rats or women receiving T.

Adipose Tissue↗

In vivo gene transfer to skin and wound by microseeding.

BACKGROUND: Gene transfer to skin has many potential applications but lacks a safe, practical delivery method. This report presents a new technique, microseeding, for in vivo gene transfer to skin and wounds and for DNA-mediated vaccination. The plasmid DNA solution was delivered directly to the target cells of the skin by a set of oscillating solid microneedles driven by a modified tattooing device. MATERIALS AND METHODS: Skin and partial-thickness excisional wounds in pigs were microseeded with either hEGF expression plasmid or beta-galactosidase expression plasmid. Human EGF was also delivered by single injection or particle bombardment. hEGF expression in wound fluid and in target tissue was determined by ELISA with anti-hEGF-specific antibodies. Additionally, weanling pigs were microseeded with a hemagglutinin of swine influenza virus expression plasmid and production of anti-HA-specific antibodies was determined by blocking ELISA. RESULTS: hEGF expression in microseeded partial thickness wounds (5664 pg/site) and skin sites (969 pg/site) peaked 2 days after transfection being four- to seven-fold higher than gene transfer by a single intradermal injection and two- to three-fold higher than particle-mediated gene transfer. The beta-galactosidase-expressing cells were detected in dermis and epidermis. Pigs microseeded with HA expression plasmid were protected from infection by the Swine influenza virus. CONCLUSIONS: These results demonstrate that microseeding is a simple and effective method for in vivo gene transfer to skin and wounds and is more efficient than single injection and particle-mediated gene transfer.

Animals↗

Central administration of dopamine D3 receptor antisense to rat: effects on locomotion, dopamine release and [3H]spiperone binding.

A 15-mer, all-phosphorothioate-modified antisense oligodeoxynucleotide (ASO) targeted against rat dopamine D3 receptor mRNA (4 microM, 5 days) significantly reduced (28%) the amount of binding sites labelled with [3H]spiperone in monolayer cultured Chinese hamster ovary (CHO) cells transfected with the complementary desoxyribonucleic acid (cDNA) for the rat D3 receptor. In contrast, D3-ASO treatment did not reduce the amount of bound [3H]spiperone in CHO cells transfected with D2 receptor cDNA. Intracerebroventricular infusion of D3-ASO (osmotic minipump, 10 microg/microl/h, 7 days) influenced dopamine receptor density in the limbic forebrain such that the upper part of the dopamine/[3H]spiperone displacement curve--tentatively representing the D3 receptor--was altered significantly. Spontaneous locomotor activity of non-habituated rats was increased significantly in D3-ASO-treated animals; in addition, in vivo microdialysis revealed a moderate increase in dopamine release in the nucleus accumbens in these animals. In all experiments, an oligodeoxynucleotide comprising the same nucleotides as the antisense sequence, but in random order, was used as control. It is concluded that the antisense strategy is useful for investigating the functional role of dopamine D3 receptors and that the dopamine D3 receptor is involved in rat locomotor behaviour.

Animals↗