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H Persson

Publications and source records attributed to H Persson.

At least 37 records · Page 2Linked to original sources
PubMed1996

Effects of BDNF and NT-4/5 on striatonigral neuropeptides or nigral GABA neurons in vivo.

Supranigral infusions of the TrkB-receptor-preferring neurotrophins BDNF or NT-4/5 augment locomotor behaviours, pars compacta firing rates and striatal dopamine metabolism. However these actions of BDNF or NT-4/5 may involve other neurotransmitter systems in addition to dopamine neurons in the substantia nigra. We thus investigated the effects of 2-week supranigral infusions of BDNF or NT-4/5 on rat peptidergic striatonigral neurons and nigral GABAergic neurons. Radioimmunoassay revealed that BDNF and NT-4/5 elevated substantia nigra levels of substance P (by 46 and 57% respectively) and substance K (by 64 and 81%). In addition, BDNF elevated substance K by 59% in a nigral projection area, the superior colliculus. NT-4/5 elevated dynorphin A in the substantia nigra (by 52%) and met-enkephalin in substantia nigra and globus pallidus (by 89%). None of these neuropeptides were altered in the striatum. Consistent with these findings, supranigral infusions of BDNF elevated the mRNA for preprotachykinin A in striatal neurons. In the same animals, glutamic acid decarboxylase (GAD)67 mRNA was increased by 48% in the substantia nigra. The cross-sectional area of GAD67-positive neuronal somata in the BDNF-infused nigra was increased by 59%, and 70% of nigral GABAergic neurons had a cross-sectional area > 550 microns2, whereas 95% of the neurons in vehicle-infused animals had cross-sectional areas < 550 microns2. Thus, supranigral infusions of BDNF or NT-4/5 increase tachykinin mRNA and protein levels within striatonigral neurons and increase the size and GAD67 mRNA expression levels of nigral GABAergic neurons. These results suggest that BDNF or NT-4/5 may modify the output of the basal ganglia not only through effects on dopamine neurons but also by increasing neurotransmission in striatonigral peptidergic and nigral GABAergic pathways.

Amphetamine↗
PubMed1996

Invasin of Yersinia pseudotuberculosis activates human peripheral B cells.

The Yersinia pseudotuberculosis cell surface-located protein invasin was found to promote binding between the pathogen and resting peripheral B cells via beta 1 integrin receptors (CD29). B cells responded by expressing several activation markers and by growing, In contrast, T cells did not react, although these cells express CD29. An isogenic invA mutant failed to activate B cells. The mutation could be complemented by providing the invA+ gene in trans. Purified invasin alone did not activate B cells, although it was able to block the binding of bacteria to the cells.

Adhesins, Bacterial↗
PubMed1996

Doxorubicin-melphalan with and without cisplatin in advanced ovarian cancer--ten-year survival results from a prospective randomized study by the Swedish Cooperative Ovarian Cancer Study Group.

In a controlled prospective randomized study the regimen doxorubicin (A) 40 mg/m2 + melphalan (M) 0.4 mg/kg was compared with A + M + cisplatin (C) 50 mg/m2 given every four weeks in advanced ovarian cancer, FIGO stage III or IV and with serous or anaplastic histology. From 1981 to 1983, 300 patients entered the study and 295 patients were evaluable for response, toxicity and long-term survival. All patients were followed for at least 10 years. The majority of patients had large residual tumours >2 cm. Patients treated with MAC had a higher response rate compared with patients treated with MA (76% vs. 50%, p < 0.01) and treatment with MAC resulted in significantly more pathological complete responders than MA. There was a significant difference in median duration of response (19 months vs. 13 months, p < 0.006) and in median survival time (26 months vs. 19 months, p = 0.05). After 5- and 10 years a significant difference in progression-free and overall survival was found. The independent prognostic factors in this study were residual tumour after primary surgery, treatment with MAC, tumour grade, ascites, and stage. Objective and subjective side effects were significantly worse with MAC, although tolerable. In conclusion, this study shows that incorporating C into MA improves the duration of progression-free survival and overall survival in women with incompletely resected Stage III or Stage IV ovarian epithelial cancer. A 5- and 10-year survival of 25% and 18%, respectively, is impressive.

Adolescent↗
PubMed1995

Alcohol dehydrogenase of class I: kiwi liver enzyme, parallel evolution in separate vertebrate lines, and correlation with 12S rRNA patterns.

Alcohol dehydrogenase class I from kiwi liver has been purified, analyzed, and compared with that of other alcohol dehydrogenases. The results show that several avian and mammalian forms of the enzyme exhibit parallel evolutionary patterns in two independent lineages of a single protein, establishing a pattern in common. Furthermore, the data correlate the enzyme evolutionary pattern with that of 12S rRNA. Biologically, the patterns complement those on ratite and other avian relationships. Functionally, the enzyme has a low Km with ethanol and a branched-chain residue at position 141, like the mammalian enzymes but in contrast to the other characterized ratite enzyme (with Ala-141 and a higher Km). This pattern of natural variability suggests a frequent but not fully complete correlation between a large residue size at position 141 and tight ethanol binding.

Alcohol Dehydrogenase↗
PubMed1995

Muscle-derived neurotrophin-4 as an activity-dependent trophic signal for adult motor neurons.

The production of neurotrophin-4 (NT-4) in rat skeletal muscle was found to depend on muscle activity. The amounts of NT-4 messenger RNA present decreased after blockade of neuromuscular transmission with alpha-bungarotoxin and increased during postnatal development and after electrical stimulation in a dose-dependent manner. NT-4 immunoreactivity was detected in slow, type I muscle fibers. Intramuscular administration of NT-4 induced sprouting of intact adult motor nerves. Thus, muscle-derived NT-4 acted as an activity-dependent neurotrophic signal for growth and remodeling of adult motor neuron innervation. NT-4 may thus be partly responsible for the effects of exercise and electrical stimulation on neuromuscular performance.

Animals↗
PubMed1995

Regulatory region in choline acetyltransferase gene directs developmental and tissue-specific expression in transgenic mice.

Acetylcholine, one of the main neurotransmitters in the nervous system, is synthesized by the enzyme choline acetyltransferase (ChAT; acetyl-CoA:choline O-acetyltransferase, EC 2.3.1.6). The molecular mechanisms controlling the establishment, maintenance, and plasticity of the cholinergic phenotype in vivo are largely unknown. A previous report showed that a 3800-bp, but not a 1450-bp, 5' flanking segment from the rat ChAT gene promoter directed cell type-specific expression of a reporter gene in cholinergic cells in vitro. Now we have characterized a distal regulatory region of the ChAT gene that confers cholinergic specificity on a heterologous downstream promoter in a cholinergic cell line and in transgenic mice. A 2342-bp segment from the 5' flanking region of the ChAT gene behaved as an enhancer in cholinergic cells but as a repressor in noncholinergic cells in an orientation-independent manner. Combined with a heterologous basal promoter, this fragment targeted transgene expression to several cholinergic regions of the central nervous system of transgenic mice, including basal forebrain, cortex, pons, and spinal cord. In eight independent transgenic lines, the pattern of transgene expression paralleled qualitatively and quantitatively that displayed by endogenous ChAT mRNA in various regions of the rat central nervous system. In the lumbar enlargement of the spinal cord, 85-90% of the transgene expression was targeted to the ventral part of the cord, where cholinergic alpha-motor neurons are located. Transgene expression in the spinal cord was developmentally regulated and responded to nerve injury in a similar way as the endogenous ChAT gene, indicating that the 2342-bp regulatory sequence contains elements controlling the plasticity of the cholinergic phenotype in developing and injured neurons.

Aging↗
PubMed1995

Synergistic trophic actions on rat basal forebrain neurons revealed by a synthetic NGF/BDNF chimaeric molecule.

Basal forebrain cholinergic neurons, which degenerate in Alzheimer's disease, respond to multiple trophic factors, including the neurotrophins, nerve growth factor (NGF) and brain-derived neurotrophic factor (BDNF). This dual responsiveness prompted us to investigate the effects of a synthetic chimaeric molecule, containing the active domains of both NGF and BDNF. The NGF/BDNF chimaeric factor exhibited synergistic actions, and was 100-fold more potent than wild-type BDNF in enhancing survival of cultured dissociated basal forebrain cholinergic neurons. This effect was apparently due to true BDNF/NGF synergy, since addition of the two wild-type trophins simultaneously reproduced the effect of the chimaera. Synergy was selective for neurons which respond to both factors; substantia nigra dopaminergic neurons, which respond to BDNF but not NGF, exhibited no potentiation. The chimaeric factor thus revealed a synergy that may normally occur in the brain, and constitutes a potentially novel therapeutic agent with greater potency than naturally occurring individual trophins.

Animals↗
PubMed1995

Pan-neurotrophin 1: a genetically engineered neurotrophic factor displaying multiple specificities in peripheral neurons in vitro and in vivo.

Pan-neurotrophin 1 (PNT-1) is a synthetic trophic factor engineered by combining active domains of the neurotrophins nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF), and neurotrophin 3 (NT-3) into an NT-3 backbone. This molecule was produced in transiently transfected COS cells or in baculovirus-infected insect cells transfected COS cells or in baculovirus-infected insect cells and subsequently purified to homogeneity. Saturation binding in embryonic spinal sensory neurons demonstrated a greater number of high-affinity binding sites for PNT-1 than for its parental molecule NT-3. PNT-1 was shown to efficiently block the chemical crosslinking of NGF, BDNF, and NT-3 to their cognate Trk receptors and to the low-affintiy NGF receptor expressed on neuronal and nonneuronal cells. PNT-1 stimulated survival and proliferation of MG87 fibroblasts expressing either TrkA, TrkB, or TrkC. PNT-1 also promoted survival of a greater number of embryonic dorsal root ganglion neurons than any of the other neurotrophins alone, and its effects were equivalent to a combination of NGF, BDNF, and NT-3. Analysis of receptor-specific neurotrophic activities demonstrated that PNT-1 efficiently rescued TrkA mRNA-containing sympathetic neurons and TrkB and TrkC mRNA-containing sensory neurons from the dorsal root and nodose ganglia. Finally, PNT-1 showed robust retrograde transport to DRG neurons in vivo after injection into the sciatic nerve. Radiolabeled PNT-1 accumulated in small-, medium-, and large-sized neurons. Coinjection with different unlabeled neurotrophins inhibited PNT-1 transport in distinct subpopulations of neurons of different sizes, suggesting that this molecule affects sensory neurons of different modalities. These results indicate that PNT-1 is a potent and multispecific neurotrophic factor that may be useful in the treatment of peripheral neurophathies and nerve damage.

Animals↗
PubMed1995

Identification of brain-derived neurotrophic factor promoter regions mediating tissue-specific, axotomy-, and neuronal activity-induced expression in transgenic mice.

The structure of rat brain-derived neurotrophic factor (BDNF) gene is complex; four 5' exons are linked to separate promoters and one 3' exon is encoding the BDNF protein. To analyze the relative importance of the regulatory regions in vivo, we have generated transgenic mice with six different promoter constructs of the BDNF gene fused to the chloramphenicol acetyl transferase reporter gene. High level and neuronal expression of the reporter gene, that in many respects recapitulated BDNF gene expression, was achieved by using 9 kb of genomic sequences covering the promoter regions that lie adjacent to each other in the genome (promoters I and II and promoters III and IV, respectively) and by including sequences of BDNF intron-exon splice junctions and 3' untranslated region in the constructs. The genomic regions responsible for the in vivo upregulation of BDNF expression in the axotomized sciatic nerve and in the brain after kainic acid-induced seizures and KCl-induced spreading depression were mapped. These data show that regulation of the different aspects of BDNF expression is controlled by different regions in vivo, and they suggest that these promoter constructs may be useful for targeted expression of heterologous genes to specific regions of the central and peripheral nervous systems in an inducible manner.

Animals↗
PubMed1995

Heart failure after myocardial infarction: the importance of diastolic dysfunction. A prospective clinical and echocardiographic study.

Clinical signs of heart failure based on predefined criteria were analysed in 217 survivors (< 75 years of age) of an acute myocardial infarction (AMI). A Doppler investigation and M-mode echocardiography were performed 3-5 days after the index infarction. All patients were stratified according to left ventricular end-diastolic diameter </> or = 28 mm.m-2 body surface area. Fractional shortening, E-point septal separation, Keren's echo-index based on left ventricular end-diastolic diameter, fractional shortening and E-point septal separation were used as indices of systolic function, and the E/A ratio and isovolumic relaxation time as indices of diastolic function. Fifty-one per cent of the patients (n = 111) had heart failure. Left ventricular end-diastolic diameter was < 28 mm.m-2 body surface area in 32 (29%) of the heart failure patients and in 44 (45%) of those without heart failure. An abnormal Keren's echo-index was found in 58 (52%) of the heart failure patients compared with 17 (18%) without heart failure. The E/A ratio was lower (0.65 vs 0.77, P = 0.01) in heart failure patients with a normal left ventricular end-diastolic diameter compared with patients without heart failure and a normal left ventricular end-diastolic diameter. Infarct size, E-point septal separation, heart rate and age were determinants of heart failure in multivariate analyses with all patients included. Infarct size and the E/A ratio were determinants of heart failure in patients with a normal left ventricular end-diastolic diameter.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1995

Expression of immediate early genes in tubular cells of rat testis.

In this study we investigated the expression of the immediate early genes (IEGs) c-fos, c-jun, and junD on mRNA and protein levels during the spermatogenic cycle of the rat using Northern blotting, in situ hybridization, and immunocytochemistry. The expression of these IEG mRNAs and proteins exhibited stage-specific variations. The results suggest that IEGs take part in transcriptional events that are involved in regulating the proliferation and differentiation of spermatogenic cells during specific stages of the cycle of the seminiferous epithelium.

Animals↗