Neurochemical and biophysical assessment of neonatal hypoxic-ischemic encephalopathy.
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Animals↗
Biomedical subjects
H Hagberg
Publications and source records attributed to H Hagberg.
Gd-DTPA-enhanced MR imaging in mediastinal Hodgkin's disease.
Gd-DTPA-enhanced MR imaging of 15 patients with primary mediastinal Hodgkin's disease was done before, during and after treatment. A total of 43 MR examinations were performed. After successful treatment, 13 patients had residual masses with reduced signal intensity (SI) ratio in the T2-weighted images. The majority of these also had decreased contrast enhancement as compared with the corresponding primary tumour. There was a significant positive correlation between the contrast enhancement and the SI ratios in the T2-weighted images of the primary tumours and/or the residual masses. Necrosis was seen in 3 of the primary tumours and one patient had a cystic residual mass. These necrotic/cystic lesions were easier to detect with the use of Gd-DTPA. Low SI ratio in the T2-weighted image and low contrast enhancement of the residual mass seem to indicate residual inactivity. Gd-DTPA facilitates the differentiation between cystic/necrotic and solid lesions.
Adolescent↗
Pulmonary function after autologous bone marrow transplantation in children.
Forty-two children receiving bone marrow autografts were studied prospectively regarding acute pulmonary complications; there was no procedure-related mortality and only one case of interstitial pneumonitis. An analysis was also made of the pulmonary function tests (PFTs) of the 27 autografted children who were disease-free and had been followed up for at least 1 year (median 4.1 years, range 1.1-7.6 years). PFTs were performed before and 6, 12, 24, 36 and 60 months after autologous BMT. The mean pre-transplant values of total lung capacity (TLC), vital capacity (VC) and forced expiratory volume in one second (FEV1) were close to predicted but 6 months after autologous BMT there was a statistically significant decrease (11, 13 and 15% below baseline, respectively) in patients receiving total body irradiation in their conditioning regimen. There was some but not complete recovery with time. DLCO remained low throughout the study, irrespective of the conditioning regimen. In summary, acute pulmonary complications were few and PFTs showed only modest changes from baseline after ABMT. At the latest follow-up no respiratory symptoms had reportedly occurred in any of the children and the chest radiographs were normal. Although the results are promising so far, long-term follow-up is necessary to evaluate the final outcome in these children.
Adolescent↗
Upregulation of calpain activity in neonatal rat brain after hypoxic-ischemia.
Neonatal rats were subjected to transient cerebral hypoxic-ischemia (unilateral occlusion of the common carotid artery plus 7.7% O2 for 2 h) and allowed to recover for 0 min, 30 min or 20 h. The calpain and calpastatin activities were assayed in subcellular fractions of the ipsilateral, hypoxic-ischemic and the contralateral, hypoxic hemisphere. An upregulation of calpain activity occurred in the hypoxic hemisphere, both in the major, cytosolic fraction and in the hypotonic, membrane associated fraction (110% and 133% of controls, respectively). The hypoxic-ischemic hemisphere displayed a decrease in calpain activity in the cytosolic fraction but an increase in the hypotonic fraction (90% and 111% of controls, respectively). The changes in calpastatin activity were less pronounced. This indicates that an upregulation of calpain activity occurs in parallel with development of hypoxic-ischemic damage. However, this upregulation is not necessarily coupled to development of injury as lesions are not seen in the hypoxic hemisphere.
Animals↗
[Malignant lymphoma. Experiences with autologous bone marrow transplantation in 50 patients].
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Adolescent↗
Cysteine sulphinate and cysteate: mediators of cysteine toxicity in the neonatal rat brain?
Excitotoxic amino acids contain two acidic groups, but cysteine represents an exception to this rule. The hypothesis that cysteine toxicity is mediated by the oxidized and diacidic metabolites cysteine sulphinate and/or cysteate was tested in the present study. The issue was approached in three different ways. Firstly, the distribution of brain injury after subcutaneous administration of cysteine (1 mg/g) to 4-day-old rats was compared with that caused by cysteine sulphinate (3 mg/g). Secondly, the effects of excitatory amino acid receptor antagonists on cysteine and cysteine sulphinate toxicity were investigated. Thirdly, the cerebral concentrations of cysteine sulphinate were determined after cysteine administration and compared with those obtained after cysteine sulphinate injection. The cerebral cortex was the region most vulnerable to cysteine toxicity, followed by the hippocampus (especially the medial subicular neurons), amygdala, caudoputamen, cerebellum and septum. Pronounced extravasation of red blood cells was observed in lesioned areas. One day after cysteine administration, the injury was infarction-like and sharply demarcated. Cysteine sulphinate-induced damage resembled cysteine-induced lesions in some respects: the anterior cingulate and retrosplenial cortices, as well as medial subicular cells, were quite vulnerable. However, the differences prevailed. Cysteine sulphinate, but not cysteine, killed neurons of the superficial part of the tectum, the medial habenula, the ventromedial hypothalamus and the arcuate nucleus. Further, while cysteine toxicity was prominent in deep cortical layers, cysteine sulphinate preferentially damaged superficial cortical neurons. Cysteine toxicity was abolished by pretreatment with MK-801, a selective NMDA antagonist, but not by 2,3-dihydroxy-6-nitro-7-sulphamoyl-benzo(F)quinoxaline, a selective AMPA receptor blocker. In contrast, the considerably smaller lesion seen after cysteine sulphinate administration was only partially prevented by MK-801. Large (19-fold) increases in cortical cysteine sulphinate concentration were noted after injection of a toxic dose of cysteine. This corresponds to 90 nmol cysteine sulphinate/g protein. The cysteate concentration was not increased above the detection limit. Injection of a toxic dose of cysteine sulphinate elevated cysteine sulphinate concentration in the frontomedial cortex (a region consistently injured by cysteine sulphinate) almost three orders of magnitude more than that observed after cysteine administration. Taken together, these results strongly suggest that neither cysteine sulphinate nor cysteate alone mediate cysteine toxicity.(ABSTRACT TRUNCATED AT 400 WORDS)
Amino Acids↗
Excitatory amino acids in the cerebrospinal fluid of asphyxiated infants: relationship to hypoxic-ischemic encephalopathy.
Asphyxiated (n = 27) and control infants (n = 25) were subjected to spinal taps. Amino acids were measured with liquid chromatography and the degree of hypoxic-ischemic encephalopathy was determined in each case. In asphyxiated infants, the concentrations of aspartate and glutamate were 286% and 387% (p < or = 0.01 and p < or = 0.05) of the control values, respectively. The cerebrospinal fluid aspartate levels were significantly (p < or = 0.05) higher in the group with severe (3.4 mumol/l) compared with the group with mild hypoxic-ischemic encephalopathy (1.0 mumol/l). Glutamate was also higher in the group with severe (12.3 mumol/l) than in the groups with mild (2.7 mumol/l) or moderate (3.2 mumol/l) hypoxic-ischemic encephalopathy (p < or = 0.05). High concentrations of excitatory amino acids were present in the CSF of asphyxiated infants which may exert excitotoxic effects.
Amino Acids↗
Quantification of inhomogeneities in malignancy grading of non-Hodgkin lymphoma with MR imaging.
In a previous study of 50 patients with non-Hodgkin lymphoma (NHL) it was shown that the inhomogeneous appearance of a tumor at MR imaging strongly indicated a high malignancy grade. In this study of 33 patients with NHL, the administration of an i.v. contrast medium, Gadolinium-DTPA, improved the subjective detectability of the inhomogeneities. A method of quantifying the degree of inhomogeneity in the tumors (inhomogeneity index, IH-index) was developed and tested. The mean value of IH-index in the T2-weighted image before contrast medium administration, and of the T1-weighted image after contrast medium administration, as well as the IH-index value in the T2-weighted image before contrast medium administration alone, was able to discriminate well between low- and high-grade NHL. This method of quantifying the degree of inhomogeneity in tumors improved sensitivity in detecting high-grade NHL.
Adult↗
Haemolytic uraemic syndrome and renal dysfunction following BEAC (BCNU, etoposide, ara-C, cyclophosphamide) +/- TBI and autologous BMT for malignant lymphomas.
Twenty-four patients autografted for malignant lymphoma have been followed. All were conditioned with BEAC (BCNU, etoposide, ara-C, cyclophosphamide), in 10 patients combined with total body irradiation (TBI) 7.5 Gy. Within 1 month of ABMT, a capillary leak syndrome was seen in four patients (one death) and isolated pericarditis in one. Nineteen patients survive disease-free at > or = 6 months, median (range) 24 (11-48) months. In 15 of 19 patients, a decrease in glomerular filtration rate (GFR) of > 20% was observed, 6 (6-24) months after ABMT. In six of these patients (five treated with TBI), the renal dysfunction was still progressing 11-36 months after ABMT. Five patients (four conditioned with TBI) developed a haemolytic uraemic syndrome (HUS) with Coombs negative haemolytic anaemia, platelet consumption and renal impairment, with onset 3-6 months after ABMT. Haemolysis and platelet consumption, but not renal impairment, were reversible in all patients. One death from HUS was seen. Because of the adverse effects described we have abandoned the combination of BEAC with TBI.
Adolescent↗
Enhanced calcium uptake by CA1 pyramidal cell dendrites in the postischemic phase despite subnormal evoked field potentials: excitatory amino acid receptor dependency and relationship to neuronal damage.
After 6-12 h of recovery from transient cerebral ischemia, the pyramidal cells of the hippocampal CA1 region take up excessive amounts of calcium upon electrical stimulation, which has been suggested to be important for the development of delayed neuronal death. The aim of this study was to further characterize this enhanced calcium uptake with respect to time-course of development, relationship to neuronal damage, and amplitude of evoked field potentials as well as the dependency on N-methyl-D-aspartate (NMDA) and non-NMDA receptors. Adult Wistar rats were used and calcium-sensitive microelectrodes were placed in the stratum radiatum of the CA1 hippocampus for recording of the extracellular calcium concentration ([Ca2+]ec) during 20 min of ischemia and for 6 h of reflow. High-frequency stimulation of the perforant pathway elicited burst firing in CA1 and a transient decrease in [Ca2+]ec which reflects neuronal uptake. Shifts in [Ca2+]ec could not be evoked 0-1 h after ischemia. However, from 1-2 h burst firing could be evoked and the accompanying shift in [Ca2+]ec increased thereafter in amplitude with prolonged reflow, exceeded preischemic levels after 4 h, and reached 250 +/- 116% (mean +/- SD) of control after 6 h of reflow (p less than 0.05). The extracellular reference potential shift during electrical stimulation and the amplitude of evoked field potentials were still subnormal after 6 h [85 +/- 25% and 83 +/- 25%, respectively (mean +/- SD)]. There was a significant correlation between the degree of stimulated calcium uptake at 6 h postischemia and the extent of CA1 damage evaluated 7 days after the ischemic insult (r = 0.849; p less than 0.001). The shifts in [Ca2+]ec were reduced by the NMDA antagonist MK-801 (0.5-2 mg/kg, i.v.) to approximately 50% of the initial level during both control and postischemic conditions (p less than 0.01). The non-NMDA antagonist 2,3-dihydroxy-6-nitro-7-sulfamoylbenzo[F]quinoxaline (NBQX) (42 +/- 13 mg/kg, i.p.; mean +/- SD) decreased the amplitude of the evoked field potentials (to 30 +/- 28% of control, p less than 0.05) and completely abolished the evoked shifts in [Ca2+]ec. In conclusion, the uptake of calcium into CA1 pyramidal cells during electrical stimulation was enhanced already 4 h after ischemia in spite of the fact that other measures of excitability were subnormal. This calcium uptake correlated to the extent of CA1 pyramidal cell damage and was dependent on both NMDA and non-NMDA receptor activation.
Analysis of Variance↗
The effect of MK-801 on cortical spreading depression in the penumbral zone following focal ischaemia in the rat.
Cortical spreading depression (CSD) is a transient depression of neuronal activity that spreads across the cortical surface. In the present studies, we have investigated CSD activity in the penumbral zone following permanent middle cerebral artery (MCA) occlusion in the rat (n = 16/group), using double-barreled Ca(2+)-sensitive microelectrodes. Measurements of CSD activity were made for 3 h in each animal. During this time, a varying number of spontaneous CSDs were seen in the control group (total was 30, with a range of 0-7/rat). These CSDs were of varying duration: "small" (approximately 1 min) and "big" (5-45 min) CSDs. During a CSD, the extracellular [Ca2+] decreased to 0.11 +/- 0.07 mM (mean +/- SD). After 3 h, the extracellular [Ca2+] in the cortex (penumbral zone) was either normal (10/16 rats) or lowered to 0.5 mM (2/16 rats) or to 0.1 mM (4/16 rats). In the caudate nucleus (ischaemic core area), all rats had an extracellular [Ca2+] of approximately 0.1 mM when measured after the 3 h recording period. Neuropathological evaluation of the brains of the animals, which had been allowed to survive for 24 h after MCA occlusion, revealed ischaemic damage in the dorsolateral cortex and caudate nucleus. Administration of the noncompetitive NMDA antagonist, MK-801 (3 mg/kg i.p.), 30 min after MCA occlusion resulted in 24 and 29% reductions in the volume of hemispheric and cortical damage, respectively, which was highly significant (p less than 0.0001); no protection was seen against caudate damage.(ABSTRACT TRUNCATED AT 250 WORDS)
Animals↗
Autologous bone marrow transplantation in children with acute lymphoblastic leukemia.
We report 25 children with acute lymphoblastic leukemia (ALL) treated with purged autologous bone marrow transplantation (ABMT) at a single center. Two children with high-risk ALL were transplanted in first remission and 23 with relapsing ALL were transplanted in second (n = 21) or third (n = 2) remission. There was no procedure-related mortality. The median time to engraftment (i.e. to reach a polymorphonuclear cell count of 0.5 x 10(9)/l) was 25 days (range 16-45 days). Seven children relapsed, four within five months after ABMT: 18 of 25 children (72%) are in continuous complete remission after a median follow-up period of 50 months (range 5-71 months). The predicted long-term disease-free survival is 65% in the whole group and 61% in those transplanted after relapse. Relapse-free children returned to normal activities within three months after ABMT. The major side effects were development of cataract and gonadal insufficiency. We consider the results promising, but our data do not allow comparison with results reported from treatment with chemotherapy alone, since some of our patients were referred from other centers and represent a selected patient group. Long-term follow-up of well-defined patient populations is necessary to evaluate the effect of ABMT.
Adolescent↗
Cerebral amino acids and energy metabolites in the growth retarded rat fetus under normoxia and hypoxia.
The effect of intrauterine growth retardation (IUGR) on striatal energy metabolites and amino acid concentrations was studied in the fetuses of eight nulliparous rat dams after uterine artery ligation on day 18 of gestation. On day 22 (term = 23), four dams were subjected to normoxia and four to hypoxia (10% oxygen) for 58 min, while monitoring hemodynamics and blood gases. After decapitation of the dam, fetuses were delivered by sectio and decapitated. The measured parameters in the dams were stable under normoxia but exhibited decreased oxygen availability under hypoxia. Striatal energy balance was preserved in IUGRs, both under maternal normoxic and hypoxic conditions, compared to appropriately grown (AGA) littermates. Under maternal normoxia, the striatal concentration of aspartate was reduced (P < 0.01) in IUGRs and the level of alanine was increased (P < 0.01) as compared to AGAs. Under hypoxia, the level of GABA was higher in IUGRs (P < 0.01). Lactate was increased in all fetuses under hypoxia. It is concluded that striatal energy metabolism is preserved in IUGR rat fetuses in late gestation under both maternal normoxia and hypoxia. Amino acid metabolism, however, is disturbed and depends on the degree of growth retardation and on the severity of perinatal stress.
Adenosine Monophosphate↗
Hypoxic-ischemic damage in the neonatal brain: excitatory amino acids.
Perinatal brain damage is a major clinical problem. Recent studies suggest that excitatory amino acids (EAAs) may be important for the development of hypoxic-ischemic brain injury in the newborn. Experimental work demonstrates that the immature brain is hypersensitive to the toxic effects EAA ('excitotoxicity'), hypoxic-ischemia is accompanied by an extracellular overflow of EAAs and hypoxic-ischemic brain damage is reduced by EAA receptor antagonists. Clinical investigations demonstrate the presence of EAA receptors in vulnerable areas of the newborn human brain and the concentrations of EAAs in the cerebrospinal fluid are higher in asphyxiated than in control infants. Clinical studies are warranted to evaluate the importance of excitotoxicity for development of brain lesions after severe asphyxia.
Amino Acids↗
[Alpha interferon treatment in hairy cell leukemia].
Since 1984 alpha-interferon (alpha IFN) has been the treatment of choice in cases of hairy-cell leukaemia. However, eight years' experience shows that, although a large majority of the patients are improved, they are not cured. Thus, a new type of cytostatic drug, perhaps capable of cure as well, may replace alpha-IFN for the treatment of hairy-cell leukaemia in the future.
2-Chloroadenosine↗
Intra- and extracellular changes of amino acids in the cerebral cortex of the neonatal rat during hypoxic-ischemia.
Excitatory amino acids (EAAs) have been implicated to play a part in the development of hypoxic-ischemic brain injury in the neonate. The aim of the present study was to follow changes of intra- and extracellular (microdialysis) amino acids in the cerebral cortex in a model where cortical hypoxic-ischemic damage is produced consistently. Hypoxic-ischemia (unilateral ligation of the carotid artery + 2 h of exposure to 7.8% oxygen) caused a depletion of tissue ATP, phosphocreatine and glucose with a concomittant accumulation of AMP and lactic acid in cortical tissue. These changes were accompanied by a decrease of tissue aspartate and glutamine whereas the contents of gamma-aminobutyric acid (GABA), phenylalanine, leucine, isoleucine, valine and alanine increased. In the extracellular fluid GABA, glutamate, aspartate, taurine, glycine and alanine all increased multi-fold during hypoxic-ischemia. Aspartate and glutamate returned to near initial levels 2 h after the end of the insult, whereas the elevation of glycine persisted during recovery. In conclusion, the high extracellular levels of EAAs and glycine may exert injurious effects during and after hypoxic-ischemia.
Amino Acids↗
[Antibiotic prevention in acute Cesarean section reduces the frequency of infectious complications].
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Anti-Bacterial Agents↗
Cellular and subcellular redistribution of glutamate-, glutamine- and taurine-like immunoreactivities during forebrain ischemia: a semiquantitative electron microscopic study in rat hippocampus.
The effect of 20 min of ischemia on the cellular and subcellular distribution of glutamate, glutamine and taurine in the rat hippocampus was studied by means of an immunocytochemical procedure based on antisera raised against protein glutaraldehyde conjugates of the respective amino acids. Forebrain ischemia was induced by temporary occlusion of the common carotid arteries in rats with permanently occluded vertebral arteries. Within 90 s after removal of the carotid ligatures, the rats were perfused through the heart with a mixture of glutaraldehyde and paraformaldehyde. For semiquantitative electron microscopic analysis, ultrathin sections were incubated in a primary antiserum followed by a secondary antibody coupled to colloidal gold particles. The gold particle densities over different tissue compartments within the CA1 field and the mossy fiber zone of the hippocampus were determined by means of a specially designed computer program, and values from normal and ischemic animals were compared. It was found that in the astrocytes, the level of immunoreactivity for glutamine and taurine is unchanged or slightly decreased after ischemia, while that for glutamate is increased, particularly within the mitochondria (by about 100%). In contrast, pyramidal cell bodies display a reduced immunolabeling for all three amino acids following the ischemic episode. The results show that ischemia causes a redistribution of glutamate from neurons to glia. The observed increase in the glial immunolabeling for glutamate indicates that the capacity of the glial cells to metabolize glutamate is exceeded during ischemia. This glial response to ischemia has not previously been recognized and may play a role in the chain of events leading to "excitotoxic" cell death during or following an ischemic episode. The reduction of glutamate and taurine immunolabeling in neurons points to a possible amino acid efflux and is compatible with previous biochemical studies demonstrating an elevated extracellular level of these amino acids during ischemia.
Animals↗