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Biomedical subjects

P Johansson

Publications and source records attributed to P Johansson.

At least 19 recordsLinked to original sources
PubMed2006

Hydroxyurea therapy increases plasma erythropoietin in patients with essential thrombocythaemia or polycythaemia vera.

The determination of serum/plasma erythropoietin (EPO) concentration has gained widespread use in the diagnosis of polycythaemia vera (PV). A reduced EPO concentration in a newly diagnosed essential thrombocythaemia (ET) seems to be a risk factor for thromboembolic events. In this study plasma EPO concentration was determined before and after initiated hydroxyurea (HU) therapy, 14 patients with PV or ET were included. After 1 month on HU therapy 11 of 14 patients had increased their EPO concentration compared with prior to medication. The plasma EPO was increased in all, except one patient, after 4 months HU therapy. If EPO is incorporated in the diagnostic or prognostic procedures it should be determined before myelosuppressive therapy is initiated.

Aged↗
PubMed2004

Oxygen affinity is decreased in patients with polycythaemia vera and essential thrombocythaemia.

The plasma erythropoietin (EPO) concentration is subnormal in the vast majority of all patients at the time of diagnosis of polycythaemia vera (PV) and in 33-50% of patients with essential thrombocythaemia (ET). At equivalent haemoglobin concentrations patients with PV and a substantial number of ET patients have subnormal EPO concentrations compared with those of healthy subjects. A possible explanation could be altered haemoglobin (Hb) oxygen affinity. Plasma EPO concentration and the oxygen pressure at 50% Hb saturation (p50) were measured in 29 patients with PV, 23 patients with ET and 34 healthy controls. There was no significant correlation between p50 and plasma EPO concentration. However, the mean p50 for PV patients exceeded the mean for healthy controls (p = 0.004). Furthermore, the mean p50 for ET patients significantly (p = 0.012) exceeded the mean for controls but there was no significant difference in p50 between patients with PV and ET. It could be hypothesized that the lower oxygen affinity to Hb in PV and ET patients partly explains the decreased EPO production.

Adult↗
PubMed2004

Trends in the incidence of chronic Philadelphia chromosome negative (Ph-) myeloproliferative disorders in the city of Göteborg, Sweden, during 1983-99.

OBJECTIVE: In the literature the incidence rates for the chronic Philadelphia chromosome negative (Ph-) myeloproliferative disorders (MPD) are known to vary extensively; only a few studies have, however, been concerned with incidence trends over time. Therefore, the aim of the present work was to investigate possible trends as regards incidence rates over time for Ph-MPD. DESIGN: Herein, we carried out a retrospective population-based survey on the incidence of polycythaemia vera (PV), essential thrombocythaemia (ET) and chronic idiopathic myelofibrosis (IMF), in the city of Göteborg (Sweden), covering the years 1983-99. RESULTS: The study comprised 416 patients with Ph-MPD. There were 205 patients with PV, 153 patients with ET, 34 with IMF and 24 with unclassified MPD. The annual incidence for PV was 1.97 per 10(5) inhabitants; the corresponding figures for ET and IMF were 1.55 per 10(5) and 0.30 per 10(5) inhabitants, respectively. There was a significant increase in the annual incidence rate for ET (P = 0.008); this increase was significant for male subjects (P = 0.015) but did not reach significance for females (P = 0.118). No such increase over time was recorded as regards PV and IMF. CONCLUSIONS: The increasing annual incidence rate for ET is most possibly explained by the more frequent use of automated platelet counts whenever a patient consults a doctor. Thereby, an increasing number of patients with overt thrombocytosis of unknown origin are discovered and will be referred to specialists within the field of haematology for a correct diagnosis.

Adult↗
PubMed2003

Surface-state Stark shift in a scanning tunneling microscope.

We report a quantitative low-temperature scanning tunneling spectroscopy (STS) study on the Ag(111) surface state over an unprecedented range of currents (50 pA to 6 microA) through which we can tune the electric field in the tunnel junction of the microscope. We show that in STS a sizable Stark effect causes a shift of the surface-state binding energy E0. Data taken are reproduced by a one-dimensional potential model calculation, and are found to yield a Stark-free energy E0 in agreement with recent state-of-the-art photoemission spectroscopy measurements.

Journal Article↗
PubMed2002

PCR-generated linear DNA fragments utilized as a hantavirus DNA vaccine.

The field of DNA vaccines has grown rapidly, and since most such vaccines involve the inoculation of large circular DNA molecules previously propagated in bacteria, several inconveniences (e.g. the presence of antibiotic resistance genes, impurities from bacterial cultures or inefficient uptake of the large and bulky plasmid DNA molecules to the nucleus) are debated. In this study, we have explored the possibility of using smaller and more flexible PCR-generated linear DNA fragments instead. Phosphorothioate (PTO)-modified primers were used successfully to protect the PCR-generated DNA fragments from exonuclease degradation, and by using a nuclear localization signal-peptide to target the linear DNA to the nucleus the immune response against the encoded antigen was further improved. This approach was tested in cell culture using a sensitive reporter system and in vivo with DNA encoding the amino-terminus of the Puumala hantavirus nucleocapsid protein. Our results indicate that linear DNA fragments have a great potential as a genetic vaccine and phosphorothioate modification in combination with a nuclear localization signal peptide increase the stability and targets the linear DNA molecules to the nucleus resulting in an improved biological response examined both in vitro and in vivo.

Animals↗
PubMed2002

On the operationalization of psychopathy: further support for a three-faceted personality oriented model.

OBJECTIVE: This study is an attempt to compare two alternative models of psychopathy (PCL-R); (i) the traditional 17-item two-factor model where the first factor describes a deceitful, manipulative and callous, unemotional dimension and the second factor describes the impulsive, irresponsible and antisocial behavioral lifestyle dimension; and (ii) a recently proposed 13-item three-factor model involving an interpersonal facet, an affective facet and a behavioral facet. METHOD: Exploratory and confirmatory factor analyses of PCL-R scores on a sample of 293 adult male violent offenders were conducted. RESULTS: The results of the exploratory factor analysis showed that the 13 items yielded three easily interpretable factors: an interpersonal factor, an affective factor and a behavioral/lifestyle factor. Through confirmatory factor analysis we showed that this model had a significantly closer fit to the data than the classical 17-item, two-factor model of the PCL-R. CONCLUSION: The study supports the three-faceted model of psychopathy.

Adolescent↗
PubMed2002

On the diagnosis of polycythaemia vera as assessed in the health and medical care in the Västra Götaland region, Sweden.

OBJECTIVES: The aim was to assess how the diagnosis of polycythaemia vera (PV) was established and to study to which extent the classic Polycythemia Vera Study Group (PVSG) criteria and the revised criteria for the diagnosis of PV as proposed by Pearson and Messinezy in 1996 (PM criteria) were fulfilled when the diagnosis of PV was made. DESIGN AND SETTING: A questionnaire was sent to physicians in charge of haematological patients at the departments of medicine in 12 hospitals in the Health and Medical Care in the Västra Götaland Region (VGR), Sweden, with a population of 1.5 million inhabitants; they were asked to provide reports as regards all patients with an unequivocal diagnosis of PV during a 5-year period from January 1994 to December 1998. SUBJECTS: Full reports were obtained from six hospitals, which serve about 1.1 million inhabitants. The results from a total of 129 PV patients, 62 from two university hospitals (UHs) and 67 from four county hospitals (CHs), were the subject of the present analysis. Results. It was shown that measurement of the red cell mass (RCM) had been carried out in 61 of 62 (98%) patients in UHs compared with 24 of 67 (36%) patients at CHs (P < 0.01). By using ultrasound imaging and/or scintigraphy the spleen size had been determined in 55 of 62 (89%) patients at UHs and in 24 of 67 (36%) patients at CHs (P < 0.01). At the UHs, arterial oxygen saturation had been measured in 32 of 62 (52%) patients; the corresponding figure for the CH patients was 22 of 67 (33%). Plasma or serum erythropoietin (EPO) concentrations had been measured in 44 of 62 (71%) of PV patients at UHs and in 31 of 67 (46%) of patients at CHs; in all these cases the EPO concentrations were subnormal or not measurable. CONCLUSIONS: At the UHs only 37% of the PV patients fulfilled the PVSG criteria for the diagnosis of PV whereas the corresponding figure for CHs was 4% (P < 0.01). The adherence to PM criteria was, however, 71% at UHs compared with 16% at CHs (P < 0.01).

Adult↗
PubMed2001

Magnetic cues trigger extensive refuelling.

Long stretches of sea and desert often interrupt the migration routes of small songbirds, whose fat reserves must be restored before these can be crossed as they provide no opportunity for refuelling. To investigate whether magnetic cues might enable inexperienced migratory birds to recognize a region where they need to replenish their body fat, we caught and held thrush nightingales (Luscinia luscinia) in Sweden just before their first migration and exposed them to a magnetic field simulating that at a migratory stopover in northern Egypt, before the Sahara Desert. We found that this magnetic field stimulated the birds to extend their fat-deposition period, indicating that magnetic cues may help small migratory birds to confront large ecological barriers.

Adipose Tissue↗
PubMed2001

Substance P endopeptidase-like activity is altered in various regions of the rat central nervous system during morphine tolerance and withdrawal.

In this study the level of a substance P endopeptidase (SPE)-like activity was measured in different regions of the rat central nervous system (CNS) after chronic administration of morphine. Male rats (200-220 g) were randomly divided into four groups. Two groups were injected (s.c.) with morphine (10 mg/kg) twice daily, whereas the other two received saline under identical conditions. After 8 days, when animals were completely tolerant to morphine, one of the morphine-treated groups and one group of saline-injected rats were given naloxone (s.c. 2 mg/kg). Withdrawal signs were observed and recorded. The enzyme activity was measured in extracts of the various CNS tissues by following the conversion of synthetic substance P (SP) to its N-terminal fragment SP(1-7) using a radioimmunoassay detecting this product. In discrete CNS areas including periaqueductal grey, spinal cord, substantia nigra and ventral tegmental area (VTA) a significant increase in enzyme activity was observed in the withdrawal group, while tolerant rats exhibited decreased SPE-like activity in the striatum (see Table 1). The enhanced enzyme activity during withdrawal is in agreement with our previous observation that the levels of SP(1-7) in rat brain are affected following naloxone precipitated withdrawal. In some tissues, including VTA, a correlation between the SPE-like activity and the intensity of the opioid abstinence was observed. Our result suggests that the elevated SPE-like activity is responsible for enhanced release of SP(1-7) in rats during morphine withdrawal, affirming a modulatory or regulative role of this enzyme in this state of opioid dependence.

Animals↗
PubMed2001

Different glycosphingolipid composition in human neutrophil subcellular compartments.

The binding of a number of carbohydrate-recognizing ligands to glycosphingolipids and polyglycosylceramides of human neutrophil subcellular fractions (plasma membranes/secretory vesicles of resting and ionomycin-stimulated cells, specific and azurophil granules) was examined using the chromatogram binding assay. Several organelle-related differences in glycosphingolipid content were observed. The most prominent difference was a decreased content of the GM3 ganglioside in plasma membranes of activated neutrophils. Gangliosides recognized by anti-VIM-2 antibodies were detected mainly in the acid fractions of azurophil and specific granules. Slow-migrating gangliosides and polyglycosylceramides with Helicobacter pylori-binding activity were found in all acid fractions. A non-acid triglycosylceramide, recognized by Gal(alpha)4Gal-binding Escherichia coli, was detected in the plasma membrane/secretory vesicles but not in the azurophil and specific granules. Although no defined roles of glycosphingolipids have yet been conclusively established with respect to neutrophil function, the fact that many of the identified glycosphingolipids are stored in granules, is in agreement with their role as receptor structures that are exposed on the neutrophil cell surface upon fusion of granules with the plasma membrane. Accordingly, we show that neutrophil granules store specific carbohydrate epitopes that are upregulated to the plasma membrane upon cell activation.

Antibodies, Monoclonal↗
PubMed2001

Langerhans cells and T cells in oral graft versus host disease and oral lichen planus.

Chronic graft versus host disease (cGVHD) of the oral mucosa, following allogeneic stem cell transplantation, and oral lichen planus (OLP) are both mucosal diseases where the immune system is involved in the pathogenesis. Although the aetiology of the two conditions is different, they present with a similar clinical appearance. This study compares the two diseases regarding the distribution of cells, which are expressing cell surface markers of interest for inflammatory responses. Monoclonal antibodies (MoAbs) were used in standard immunohistochemical procedures. CD1a+, CD80+ and CD86+ cells in the epithelium of OLP- and cGVHD lesions had the dendritic morphology of Langerhans cells (LC). Higher frequencies of CD1a+ LC as well as CD25+ cells were observed in the OLP epithelium than in the cGVHD epithelium. The OLP lesions showed higher frequencies of subepithelial cells expressing CD1a, CD86, CD4, CD8 and CD25 than the cGVHD lesions. Notably there was a significantly higher frequency of CD25+ cells in the epithelium and the connective tissue of OLP than in cGVHD. These cells might represent regulatory T cells. In conclusion, cGVHD and OLP show marked differences at the cellular level despite similar clinical appearance. Hence, the findings indicate differences in the regulation of the inflammatory response between the two conditions.

Adult↗
PubMed2001

Intensive use of intravascular ultrasound during coronary angioplasty. A six-month campaign.

BACKGROUND: Compared to coronary angiography, intravascular ultrasound (IVUS) gives additional information important for the percutaneous transluminal coronary angioplasty (PTCA) procedure, but is time-consuming and may cause complications. AIM: To evaluate, during a period of intensive use of IVUS, the impact of IVUS on the final decision on balloon/stent diameter, consumption of devices, time-consumption and IVUS-related complications. METHOD: During a 6-month period, IVUS was contemplated in all PTCA procedures and the reason for not using IVUS was specified. We used CVIS during the first, and Endosonics during the last 3 months, and both periods started with 1 week of hands-on practice. All procedures were to be planned according to an initial quantitative coronary angiography (QCA), and the finally achieved result, material used and complications were registered. RESULTS: The proportion of IVUS/PTCA was 37% during, 8% 6 months before and 12% 6 months after the study period. Three hundred and twenty-three patients were included in the study (57% of all patients), 199 of them were subjected to IVUS. The indications for PTCA during the study period were stable angina (58%), unstable angina (32%) and acute myocardial infarction (10%). The main reasons for not doing IVUS were use of 6F guiding catheter (13%), urgent procedure (12%) and occluded vessel (11%). Initial QCA detected 253 stenoses in 199 patients and 64 additional stenoses were treated, most of them probably detected by IVUS. QCA systematically underestimated vessel size, particularly in small vessels. There was a non-significant trend to more accurate estimations towards the end of the study in small vessels. Dissection, probably due to IVUS, occurred in two cases (1%). There were no significant differences in the number of devices used in IVUS compared to non-IVUS patients. The procedural time was 24 min longer in IVUS than in non-IVUS cases and more stenoses were treated per procedure in the IVUS group. CONCLUSION: Coronary angiography often underestimated balloon/stent size but in an unpredictable way, with a substantial proportion of significant stenoses being undetected. IVUS had few serious complications, did not increase device consumption but prolonged procedural time.

Adult↗
PubMed2000

Effects of the androgenic anabolic steroid, nandrolone decanoate, on adrenocorticotropin hormone, corticosterone and proopiomelanocortin, corticotropin releasing factor (CRF) and CRF receptor1 mRNA levels in the hypothalamus, pituitary and amygdala of the rat.

There is increasing abuse of androgenic anabolic steroids (AAS) by non-athletes. AAS abuse has been associated with psychiatric symptoms such as mania, major depression and aggression and the development of dependence. Little is known about the effects of AAS on hypothalamic-pituitary-adrenal axis function or corticotropin releasing factor, which may be involved in mediating some of the psychiatric symptoms associated with AAS abuse. Male Sprague-Dawley rats received one daily intra-muscular injection of the AAS nandrolone decanoate (ND, 15 mg/kg) or vehicle for 3 days. Animals were sacrificed either 1 h or 24 h after the last injection, brain regions dissected and trunk blood collected. Corticotropin releasing factor (CRF), CRF receptor1 (CRF-R1) and proopiomelanocortin (POMC) mRNAs were measured with solution hybridization/RNase protection. Circulating levels of corticosterone and adrenocorticotropin hormone (ACTH) were determined using radioimmunoassays. One hour following the last injection, ND significantly increased circulating levels of both corticosterone and ACTH levels. In the amygdala, CRF mRNA levels were unchanged 1 h after the last injection of ND but were significantly reduced at 24 h. The same was found for hypothalamic POMC. No significant AAS effects were observed on: hypothalamic CRF mRNA; POMC mRNA in the amygdala or CRF R1 mRNA in the anterior pituitary.

Adrenocorticotropic Hormone↗
PubMed2000

The effect on opioid peptides in the rat brain, after chronic treatment with the anabolic androgenic steroid, nandrolone decanoate.

In recent years, an increase in abuse of anabolic androgenic steroids (AAS) has been seen among individuals not directly connected to sports. Clinical evidence suggests that abuse of these steroids may result in profound changes in personality, expressed by depressive symptoms, irritability and increased aggression. It is still unknown whether these alterations are related to changes in any particular transmitter system or whether they are persistent or reversible. In this study we focused on AAS effect on the endogenous dynorphin and enkephalin system in the brain. Male rats were given intramuscular injections of the AAS nandrolone decanoate (15 mg/kg), once daily for 2 weeks. The levels of the opioid peptide immunoreactivities (ir) were assessed by radioimmunoassay in two groups immediately after the treatment and in two other groups after additional 3 weeks without any drug treatment (recovery period). The result indicates that chronic AAS treatment increased the activity in the dynorphin B- and Met-enkephalin-Arg(6)Phe(7)-ir in the hypothalamus, striatum and periaqueductal gray (PAG) compared to controls. In addition, the steroid induced an imbalance between the dynorphin and the enkephalin opioid system in the nucleus accumbens, hypothalamus and PAG. This imbalance remained after the recovery period. Since increased peptide activity was found in brain regions regulating emotions, dependence, defensive reactions and aggression, it was suggested that the actual endogenous opioid systems are involved in previously reported AAS-induced changes in these behaviours.

Anabolic Agents↗
PubMed2000

Anabolic androgenic steroids affects alcohol intake, defensive behaviors and brain opioid peptides in the rat.

The present study investigated whether a relationship exists between nandrolone decanoate and voluntary ethanol intake in laboratory rats. Animals were subjected to daily subcutaneous injections with nandrolone decanoate (15 mg/kg) during 2 weeks. One group of animals was tested for voluntary alcohol intake 1 week after the end of the 2-week treatment period and another group received alcohol 3 weeks after the treatment. In addition, assessment of defensive behaviors and immunoreactivity (ir) levels of the brain opioid peptides dynorphin B and Met-enkephalin-Arg-Phe (MEAP) were performed. The nandrolone decanoate-treated animals were significantly more aggressive and showed lower fleeing and freeezing reaction than the oil-treated controls. Treatment with nandrolone decanoate enhanced voluntary alcohol intake, regardless if it was presented 1 or 3 weeks after end of the treatment period. These animals had a decreased activity of dynorphin B-ir in the nucleus accumbens, decreased levels of MEAP-ir in the periaqueductal gray (PAG) and higher levels of MEAP-ir in the hypothalamus compared to controls. In line with previous studies, this suggests that the altered dynorphin B-ir activity may promote the rewarding effects of ethanol and thereby increasing alcohol intake, whereas MEAP-ir may be associated with the ability to control the aggressive reaction. Abuse of nandrolone decanoate may thus constitute a risk factor for increased alcohol consumption and defensive aggression. In human, this constellation of behavioral symptoms is closely related to acts of crimes and violence and is often observed among those abusing anabolic androgenic steroids.

Aggression↗
PubMed2000

Anabolic-androgenic steroids affect the content of substance P and substance P(1-7) in the rat brain.

The effects of intramuscular (i.m.) injections of nandrolone decanoate (15 mg/kg/day), an anabolic-androgenic steroid, on the levels of substance P (SP) and on its N-terminal fragment SP(1-7) were examined in the male rat brain by radioimmunoassay. The results demonstrated that the SP immunoreactivity in amygdala, hypothalamus, striatum, and periaqueductal gray was significantly enhanced, whereas the concentration of the N-terminal fragment SP(1-7) was enhanced in the nucleus accumbens and in periaqueductal gray. In the striatum the steroid induced a decrease in the content of SP(1-7). The relevance of these peptides in connection with anabolic-androgenic steroid-induced aggression is discussed.

Anabolic Agents↗
PubMed2000

A strain of human influenza A virus binds to extended but not short gangliosides as assayed by thin-layer chromatography overlay.

A human strain of influenza virus (A, H1N1) was shown to bind in an unexpected way to leukocyte and other gangliosides when compared with avian virus (A, H4N6) as assayed on TLC plates. The human strain bound only to species with about 10 or more sugars, while the avian strain bound to a wide range of gangliosides including the 5-sugar gangliosides. By use of specific lectins, antibodies, and FAB and MALDI-TOF mass spectrometry an attempt was done to preliminary identify the sequences of leukocyte gangliosides recognized by the human strain. The virus binding pattern did not follow binding by VIM-2 monoclonal antibody and was not identical with binding by anti-sialyl Lewis x antibody. There was no binding by the virus of linear NeuAcalpha3- or NeuAcalpha6-containing gangliosides with up to seven monosaccharides per mol of ceramide. Active species were minor NeuAcalpha6-containing molecules with probably repeated HexHexNAc units and fucose branches. This investigation demonstrates marked distinctions in the recognition of gangliosides between avian and human influenza viruses. Our data emphasize the importance of structural factors associated with more distant parts of the binding epitope and the complexity of carbohydrate recognition by human influenza viruses.

Carbohydrate Sequence↗