Search PubMed⌕ Search

Biomedical subjects

H Persson

Publications and source records attributed to H Persson.

At least 271 records · Page 15Linked to original sources
PubMed1988

Whole body fat oxidation before and after carnitine supplementation in uremic patients on chronic haemodialysis.

This study has evaluated whether uremic patients on chronic haemodialysis with subnormal plasma levels of free carnitine show any alterations in whole body fat oxidation before and after one week with carnitine supplementation (60 mg/kg/day). Carnitine plasma levels changed from subnormal to supranormal levels of both free and total carnitine concentrations. This increase was not associated with any alteration in either oxygen uptake, carbon dioxide production, respiratory quotient or blood substrate levels such as glucose, glycerol, free fatty acids and lactate. The fractional oxidation of an intravenously infused fat emulsion (Intralipid) was 17% before and 19% after carnitine supplementation. No side effects were observed in spite of the rather high dose of carnitine administration. This study failed to demonstrate any impact on net whole body fat oxidation in carnitine substituted uremic patients with initially subnormal levels of free plasma carnitine.

Calorimetry, Indirect↗
PubMed1988

Production and characterization of biologically active recombinant beta nerve growth factor.

DNA fragments encoding either rat or chicken beta nerve growth factor (NGF) were inserted in the expression vector p91023(B) for transient expression in COS cells. The two NGF constructs produced RNA transcripts and proteins of the predicted sizes. Conditioned media from the transfected cells stimulated neurite outgrowth from cultured chicken embryo sympathetic ganglia. The results show that the rat or chicken NGF gene can direct the synthesis of a biologically active NGF protein after transfection of COS cells.

Animals↗
PubMed1988

Health careers--a method of health education at school for adolescents.

An innovative health education curriculum, "Health Careers", intended for adolescents leaving school, was evaluated using a quasi-experimental pre-/post control group design. The objective of the project was the modification of knowledge, attitudes and behaviour in relation to health. Attempts were made to counteract factors restricting the effect of traditional health education at school. Changes were estimated using questionnaires. Two types of schools were studied, schools A and B, student age averaged 17.3 years and 15.5 years, respectively. The number of students in the experimental groups was 220 and 112, respectively. At school B, in addition, 35 parents participated voluntarily in evening courses arranged by the project staff. Significant improvement was shown in two variables of a possible 60 at school A and in four variables at school B. Analysis by subgroups, however, demonstrated improvements in merely one variable at school B. It is evident that the innovative curriculum did not induce significant behavioural improvement in relation to health. Frame factors of the school--obligatory student participation and teacher role perception--may explain this outcome.

Adolescent↗
PubMed1988

Detection of nerve growth factor mRNA in the developing chicken embryo.

Nerve growth factor (beta NGF) is a protein supporting sympathetic and sensory innervation in the peripheral tissues as well as cholinergic innervation in the brain. A DNA probe derived from a genomic clone coding for chicken NGF was used to study NGF mRNA levels during development. NGF mRNA was detected in the chicken embryo as early as day 3.5 of incubation. The level of NGF mRNA in total embryo increased four-fold until day 8, remained high until day 12, and subsequently decreased. No corresponding peak in NGF mRNA expression was found in heart and brain measured separately. Instead these organs showed increased NGF mRNA levels after hatching. The highest levels of NGF mRNA in the day-8 embryo were found in skin and eye (in particular cornea, but also iris, sclera-choroid and neural retina) suggesting a correlation between sensory innervation and this early peak of NGF expression.

Animals↗
PubMed1988

Localization of mRNA for the beta-subunit of placental hCG by in situ hybridization.

The cellular origin of placental hCG is not yet completely established. Depending on the method used, the syncytium, cytotrophoblast or both types of tissue have been claimed to synthesize hCG. In the present study in situ hybridization was used on sections of chorionic villi in order to detect expression of the gene for the beta-subunit of hCG (beta-hCG). Placental tissue was obtained from the 8th to the 11th weeks of pregnancy, when the concentration of hCG is high. A cDNA clone, encoding the entire amino acid sequence of beta-hCG, was used as a probe. Hybrids of beta-hCG cDNA/mRNA were found only over the syncytiotrophoblast. Background noise was extremely low and no signals above that were detected in the cytotrophoblast cells. It is concluded that at this stage of pregnancy the gene for beta-hCG is activated in the syncytial parts of chorionic villi and not in the cytotrophoblast.

Autoradiography↗
PubMed1987

Decreased level of nerve growth factor (NGF) and its messenger RNA in the aged rat brain.

Trophic factors such as nerve growth factor (NGF) are thought to support survival, differentiation and maintenance of neurons. Recent results indicate that NGF produced in cortical and hippocampal areas is required for the function of cholinergic neurons in the basal forebrain. With the use of enzyme immunoassay and RNA blot hybridization we studied the NGF protein and NGF mRNA, respectively, in regions of the brain innervated by basal forebrain cholinergic neurons in adult and aged rats. Levels of NGF protein were decreased by 40% in hippocampus of aged (28 months) Fischer 344 rats compared with adults (6 months), whereas no alterations were observed in cerebral cortex. Moreover, a reduction by 50% in the NGF mRNA was found in samples of the aged forebrain (cerebral cortex, hippocampus, basal forebrain and hypothalamus) compared to the adult. NGF deficiencies may thus account for the loss of cholinergic neurons in the basal forebrain generally found to accompany normal aging and resulting in altered cognitive functions.

Aging↗
PubMed1987

Detection of neuropeptide Y and its mRNA in megakaryocytes: enhanced levels in certain autoimmune mice.

Neuropeptide tyrosine (neuropeptide Y, NPY) is a potent vasoconstrictor with a wide distribution in the central and peripheral nervous systems. Here we show that high levels of rat NPY mRNA are also found in peripheral blood cells, bone marrow, lung, and spleen. Furthermore, radioimmunoassay revealed high levels of NPY-like peptide in these tissues. In mice, the levels of splenic NPY mRNA and immunoreactive peptide differed extensively between strains and were greatly elevated in several strains (NZB, NZBxW, and BXSB) that develop a disease resembling human systemic lupus erythematosus. Like the rat, the NZB mouse showed a high content of NPY mRNA in peripheral blood cells and bone marrow. Immunohistochemical staining revealed NPY-like immunoreactivity in large cells morphologically identifiable as megakaryocytes in rat bone marrow and in the spleen of the NZB mouse strain. Expression of NPY mRNA in megakaryocytes in rat bone marrow and NZB mouse spleen was confirmed by in situ hybridization. These results indicate that NPY is synthesized in megakaryocytes, implying that NPY can be released from platelets and function as a vasoconstrictor during blood-vessel damage. In addition, the increase in splenic NPY in certain autoimmune mouse strains adds to the list of abnormalities associated with these strains.

Animals↗
PubMed1987

Structure and expression of the gene encoding the vasoactive intestinal peptide precursor.

The gene encoding the human vasoactive intestinal peptide (VIP) and the histidine-methionine amide (PHM-27) peptide hormone was isolated from lambda phage libraries. The human gene was found to be composed of seven exons spanning approximately 9 kilobase pairs. The first exon codes for an untranslated leader sequence, and the second exon codes for a putative signal peptide. DNA sequences coding for the VIP and PHM-27 hormones are located in two different exons. Southern blot analysis with genomic DNA suggested that a single copy of the VIP/PHM-27 gene is present in the human haploid genome. The expression of VIP/PHM-27 precursor mRNA in various tissues in the rat was analyzed by RNA gel blot hybridization. In the organs examined, expression was only detected in the brain and duodenum. RNA isolated from various regions of the rat brain--including the cortex, hypothalamus, and hippocampus--hybridized to both VIP- and PHM-27-specific probes. The same pattern of hybridization was found when VIP- and PHM-27-specific probes were used, suggesting that possible differences in the localization of VIP and PHM-27 peptides between different brain regions cannot be accounted for by differential RNA processing.

Amino Acid Sequence↗
PubMed1987

Structure and expression of the rat neuropeptide Y gene.

Neuropeptide Y is a 36-amino acid peptide that is abundant throughout the mammalian nervous system. It belongs to the same family of carboxyl-terminally amidated peptides as pancreatic polypeptide and peptide YY. We describe here the gene encoding the rat neuropeptide Y precursor. The gene spans 7.2 kilobase pairs and contains four exons. The exon organization is identical to the pancreatic polypeptide gene, although the amino acid sequences of the neuropeptide Y and pancreatic polypeptide precursors differ extensively. The predicted amino acid sequence of mature rat neuropeptide Y is identical to the human sequence. Also the sequence of the 30-amino acid carboxyl-terminal peptide of preproneuropeptide Y is highly conserved, which suggests that it is functionally important. Two neuropeptide Y alleles were found to differ at nine positions in 2.5 kilobase pairs at the 5' portion of the gene. No exon difference was found. One nucleotide substitution close to the gene promoter may influence the regulation of expression. Neuropeptide Y mRNA was found in all rat brain subregions tested, which shows that neuropeptide Y is synthesized throughout the brain. Developmentally, mRNA was detected in the rat brain as early as embryonic day 16 and increased rapidly to adult levels. The level of neuropeptide Y mRNA was also studied in several rat peripheral organs. Unexpectedly high levels were observed in heart and spleen. This mRNA may be synthesized in intrinsic ganglia and non-neuronal cells, respectively.

Alleles↗
PubMed1987

A molecular genetic approach to the identification of genes expressed predominantly in the neuroendocrine and immune systems.

Our results demonstrate that expression of neuropeptide tyrosine, one of the most abundant and widespread peptides in the mammalian nervous system, occurs in non-neuronal cells, in keeping with the emerging view that neuropeptide synthesis is not restricted to cells of the nervous system. RNA blot analyses and radioimmunoassays detected both NPY mRNA and NPY peptide in rat and mouse spleen, bone marrow, and peripheral blood cells. Immunohistochemical staining of sections from rat bone marrow with an NPY-specific antiserum revealed NPY-like immunoreactivity in megakaryocytes. In situ hybridization confirmed that the NPY-like peptide detected in megakaryocytes was synthesized de novo from NPY mRNA present in these cells. Megakaryocytes, the platelet-forming cells, originate from pluripotent hematopoietic stem cells present in the bone marrow as well as in the spleen of rodents. During microvascular damage, platelets aggregate at the damaged site and release bioactive substances. NPY is known to be a potent vasoconstrictor. Therefore, we propose that megakaryocyte-derived NPY is stored in platelets and released during platelet aggregation, resulting in a long-lasting vasoconstriction. Greatly elevated levels of megakaryocyte-derived NPY, as compared to the level found in BALB/C mice, were found in several mouse strains (NZB, NZB x W, and BXSB) which develop an autoimmune disease resembling systemic lupus erythematosus. Whether the elevation of megakaryocyte-derived NPY plays a role in the autoimmune disease progression in these mice or whether it merely reflects a related hematopoietic abnormality remains to be determined. Subtractive hybridization was used to isolate two cDNA clones that are predominantly expressed in the brain and the immune system. These and similarly derived cDNA clones will be used as molecular probes to study the mechanisms governing tissue-specific expression in the nervous and immune systems. Discovering the function of the proteins encoded by such cDNA clones may reveal evolutionary mechanisms shared by the nervous and immune systems, as well as a molecular basis for the interaction between these systems.

Animals↗
PubMed1987

No difference in outcome between 314 nontransfused and 614 transfused cadaveric renal transplant recipients: the Scandinavian experience.

Pretransplant blood transfusions had no beneficial effect on the graft survival rate, the rejection frequency, or the quality of graft function in a case material consisting of 928 cadaveric kidney transplant recipients treated with 3 different CsA dose protocols. When younger recipients, PRA-negative recipients, or recipients receiving poorly HLA-matched kidneys were analyzed separately, there was still no transfusion effect. In the most recent series, the one-year graft survival rate was 84% among 164 nontransfused patients, and in 73 nontransfused patients under 50 years of age it was 90%. We conclude that with present day immunosuppressive therapy, based on CsA, there is no case for pretreatment blood transfusions. Indeed, this practice might place the renal transplant patient at a disadvantage.

Blood Transfusion↗