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Biomedical subjects

H Hagberg

Publications and source records attributed to H Hagberg.

At least 163 records · Page 9Linked to original sources

Placenta previa and antepartum hemorrhage after previous cesarean section.

A prospective study was conducted to determine the risk of placenta previa and unexplained antepartum hemorrhage after a previous cesarean section (CS). Of a total of 24,644 patients, 81 (0.33%) had a placenta previa which demanded abdominal delivery. The risk of placenta previa was 0.25% with an unscarred uterus and 1.22% in patients with one or more previous CS (the difference was statistically significant p less than 0.001). The corresponding figures for unexplained antepartum hemorrhage were 0.40% and 3.81%, respectively (p less than 0.001). Patients presenting with a placenta previa and a scarred uterus had a 16% risk of undergoing cesarean hysterectomy because of placenta accreta and severe hemorrhage compared to 3.6% in patients with placenta previa and an unscarred uterus. In conclusion, cesarean deliveries predispose to placenta previa, placenta accreta and antepartum hemorrhage during subsequent pregnancies. This relationship has to be considered in the cost-benefit equation for decision of route of delivery.

Cesarean Section↗

Prognostic factors in non-Hodgkin lymphoma stage I treated with radiotherapy.

The results of treatment in 175 consecutive patients with nonHodgkin lymphoma (NHL) clinical stage I treated between 1969 and 1984 were analysed according to different pretreatment prognostic variables. Treatment consisted of radiotherapy in 166 of the 175 patients. The estimated 5 and 10-year disease-free survival rates (DFS) were 63% and 60% and the survival rates at 5 and 10 years 82% and 76% respectively. Lymphomas arising from gut-associated lymphoid tissue, i.e. Waldeyer's ring, the thyroid and the gastrointestinal tract had a more favourable clinical course (10-year projected DFS 83%) than nodal (50%) and other extranodal lymphomas. Although the number of patients with other extranodal sites was small, sites such as testis, nasal cavity, paranasal sinus and extradural space seemed to have a high relapse rate. Unfavourable clinical courses were also observed among nodal high-grade NHL if the lymph nodes were larger than 5 cm in diameter. Chemotherapy before radiotherapy may be recommended in NHL subgroups with a high relapse rate and which today are potentially curable with chemotherapy, i.e. highgrade NHL. This study indicates that large nodal lymphomas and some extranodal sites belong to this group.

Adult↗

The excitatory amino acid antagonist kynurenic acid administered after hypoxic-ischemia in neonatal rats offers neuroprotection.

The neuroprotective effect of kynurenic acid, an unspecific antagonist of excitatory amino acid receptors, was evaluated in a model of hypoxic-ischemia in neonatal rats. One-week-old rats were subjected to ligation of the left carotid artery and exposure to 7.7% O2/92.3% N2 for 2 h. Kynurenic acid (300 mg/kg) was administered i.p. immediately after the period of hypoxic-ischemia in one group (n = 32) and compared with saline-treated (n = 27). After 2 weeks the rats were sacrificed and the brain damage evaluated by comparing the weight of the lesioned and unlesioned hemispheres. In rats receiving kynurenic acid the reduction in weight of the lesioned hemisphere was 25.4 +/- 3.3% as compared to 37.8 +/- 3.6% in saline-treated controls (P less than 0.001). The results suggest that excitatory amino acids are involved in the development of postischemic damage in the immature brain.

Animals↗

Calcium uptake evoked by electrical stimulation is enhanced postischemically and precedes delayed neuronal death in CA1 of rat hippocampus: involvement of N-methyl-D-aspartate receptors.

Extracellular calcium concentration changes in the CA1 of the hippocampus during burst activity were measured during postischemic reflow, and the involvement of N-methyl-D-aspartate (NMDA) receptors was evaluated. In adult Wistar rats global ischemia was induced by four-vessel occlusion for 20 min. After 6 h of postischemic reflow, the animals were halothane-anesthetized and reintubated. A double-barrelled calcium-sensitive microelectrode was advanced through stratum oriens, pyramidale, and radiatum in 50-micron steps. At each step the perforant pathway was stimulated (15 Hz, 30 s), and changes in extracellular calcium concentration were recorded. High-frequency stimulation elicited burst firing and transient decreases in extracellular calcium concentration, which are interpreted as neuronal calcium uptake. In control hippocampus, the extracellular calcium decreases were maximal in the stratum pyramidale. Six to eight hours after ischemia, a threefold enhancement of extracellular calcium decreases was found in the dendritic layers of the CA1. The NMDA-receptor antagonist ketamine (15-30 mg/kg intraperitoneally) reduced these electrically evoked calcium decreases. Seven days after ischemia, there was a 60-90% loss of pyramidal cells in the CA1. In conclusion, the cellular calcium uptake, possibly through NMDA receptors evoked by neuronal activity, is enhanced during early postischemia and precedes delayed neuronal death.

Animals↗

Prognostic relevance of serum-markers in relation to histopathology, stage and initial symptoms in advanced low-grade non-Hodgkin lymphomas.

The prognostic relevance of 4 different serum markers (deoxythymidine kinase = S-TK, lactic dehydrogenase = S-LDH, S-Haptoglobin and S-Orosomucoid) in relation to histopathology according to the Kiel classification, stage and presence or absence of initial symptoms were investigated in 168 consecutive cases of low-grade non-Hodgkin lymphomas (NHL). All serum markers, as well as the other three parameters, gave prognostic information. Univariate analysis yielded a high predictive value (p less than 0.0002) for both S-TK and S-LDH. The best information regarding the probability of survival was, however, obtained from the presence or absence of symptoms from lymphoma manifestations other than those caused by a strictly local tumor mass. Since S-TK and S-LDH correlated well with each other, only the better of them, S-TK, gave information additional to initial symptoms in a multivariate test.

Aged↗

Recombinant interferon-alpha-2b treatment of hairy-cell leukaemia: experience with a low-dose schedule.

50 patients with hairy cell leukaemia (HCL) were treated with recombinant interferon (IFN) alpha-2b 2.0 x 10(6) IU/m2 subcutaneously three times weekly to evaluate the efficacy of low-dose IFN therapy in inducing and maintaining remission of the disease. At the time of this report 48 patients, of whom 22 were splenectomized, had been treated for at least 3 months and were considered evaluable for response. The median observation time on IFN-alpha-2b was 11 months (range 3 to 20). 4 cases with atypical disease (spongy lymphoid myelofibrosis) were also included. All patients responded to IFN. After 3 months 11/48 patients (23%) had achieved a partial remission (PR) with normalization of peripheral blood values. After 6 months 27/43 patients (63%) had achieved a favourable response; complete remission (CR) was recorded in 4 and PR in 23 patients. The proportion of patients with favourable responses (CR + PR) increased with the duration of therapy and after 12 months of therapy 23/28 (82%) patients showed CR or PR, 9 patients (32%) being in CR. Splenectomized patients disclosed a trend towards a more rapid response. It is concluded that IFN-alpha-2b is a highly effective first-line therapy for HCL.

Adult↗

Low dosage alpha-interferon treatment in patients with advanced cutaneous T-cell lymphoma.

Treatment with high dose (10-50 x 10(6) IU/m2 three times a week) of alpha-interferon (alpha-IFN) has been shown to induce remissions in about 50% of patients with cutaneous T-cell lymphoma. The optimal alpha-IFN dose, however, is not known. 4 patients with advanced cutaneous T-cell lymphoma were therefore treated with alpha-IFN in low doses of 2-4 x 10(6) IU/m2 three times a wk. 1 complete, 1 partial and 1 minor remission were observed. Skin biopsies before and during treatment were taken from 2 of the patients and showed improvement. Low doses of alpha-IFN can thus induce remission in patients with cutaneous T-cell lymphoma.

Adult↗

Analysis of amino acids: neurochemical application.

For high sensitivity analysis of neuroactive amino acids, liquid chromatography employing precolumn derivatisation with o-phthalaldehyde (OPA) is suitable for several reasons. The OPA reagent is non-fluorescent per se, the reaction occurs rapidly in alkaline aqueous solutions and forms highly fluorescent derivatives with primary amines.

Amino Acids↗

Extracellular overflow of glutamate, aspartate, GABA and taurine in the cortex and basal ganglia of fetal lambs during hypoxia-ischemia.

Extracellular levels of excitatory and inhibitory amino acids were measured in the cortex and striatum of asphyxiated fetal lambs. The fetus was exteriorized from the anesthetized ewe and dialysis probes were placed in the parietal cortex and caudate nucleus. Cerebral blood flow was measured with Xe-clearance. Cortical somatosensory-evoked potentials and electroencephalogram (EEG) were continuously recorded. Asphyxia was induced by clamping the umbilical cord or by graded compression of the maternal aorta. Asphyxia accompanied by elevated cerebral blood flow resulted in a moderate rise in extracellular amino acid levels. During extreme asphyxia, i.e. abolished evoked potentials and reduced cerebral blood flow, marked extracellular elevations of glutamate (3- to 11-fold), aspartate (3- to 7-fold), gamma-aminobutyric acid (GABA) (3- to 5-fold) and taurine (3- to 18-fold) occurred, the higher values representing striatum. Excessive levels of excitatory amino acids may exert injurious effects on immature neurons during such hypoxic-ischemic states.

Amino Acids↗

2-Amino-5-phosphonovalerate attenuates the severe hypoglycemia-induced loss of perforant path-evoked field potentials in the rat hippocampus.

The effects of severe hypoglycemia on perforant path-evoked field potentials were examined in the rat hippocampus. Although a complete loss of this response was noted when blood glucose concentration fell below 1 mM, this occurred before cessation of electroencephalogram (EEG) activity. Both spontaneous and evoked responses recovered partially following glucose readministration. D-2-Amino-5-phosphonovalerate, an NMDA-sensitive acidic amino acid receptor antagonist, facilitated this recovery from the hypoglycemic challenge when administered via a dialysis probe.

2-Amino-5-phosphonovalerate↗

Extracellular adenosine, inosine, hypoxanthine, and xanthine in relation to tissue nucleotides and purines in rat striatum during transient ischemia.

Extracellular (EC) adenosine, hypoxanthine, xanthine, and inosine concentrations were monitored in vivo in the striatum during steady state, 15 min of complete brain ischemia, and 4 h of reflow and compared with purine and nucleotide levels in the tissue. Ischemia was induced by three-vessel occlusion combined with hypotension (50 mm Hg) in male Sprague-Dawley rats. EC purines were sampled by microdialysis, and tissue adenine nucleotides and purine catabolites were extracted from the in situ frozen brain at the end of the experiment. ATP, ADP, and AMP were analyzed with enzymatic fluorometric techniques, and adenosine, hypoxanthine, xanthine, and inosine with a modified HPLC system. Ischemia depleted tissue ATP, whereas AMP, adenosine, hypoxanthine, and inosine accumulated. In parallel, adenosine, hypoxanthine, and inosine levels increased in the EC compartment. Adenosine reached an EC concentration of 40 microM after 15 min of ischemia. Levels of tissue nucleotides and purines normalized on reflow. However, xanthine levels increased transiently (sevenfold). In the EC compartment, adenosine, inosine, and hypoxanthine contents normalized slowly on reflow, whereas the xanthine content increased. The high EC levels of adenosine during ischemia may turn off spontaneous neuronal firing, counteract excitotoxicity, and inhibit ischemic calcium uptake, thereby exerting neuroprotective effects.

Adenosine↗

Cellular origins of endogenous amino acids released into the extracellular fluid of the rat striatum during severe insulin-induced hypoglycemia.

The effect of severe insulin-induced hypoglycemia on the extracellular levels of endogenous amino acids in the rat striatum was examined using the brain microdialysis technique. A characteristic pattern of alterations consisting of a 9-12-fold increase in aspartate (Asp), and more moderate increases in glutamate (Glu), taurine (Tau), and gamma-aminobutyric acid (GABA), was noted following cessation of electroencephalographic activity (isoelectricity). Glutamine (Gln) levels were reduced both during and after the isoelectric period and there was a delayed increase in extracellular phosphoethanolamine (PEA) content. The effects of decortication and excitotoxin lesions on the severe hypoglycemia-evoked efflux of endogenous amino acids in the striatum were also examined. Decortication reduced the release of Glu and Asp both 1 week and 1 month post-lesion. The efflux of other neuroactive amino acids was not affected significantly. In contrast, GABA, Tau, and PEA efflux was attenuated in kainate-lesioned striata. Glu and Asp release was also reduced under these conditions, and a smaller decrease in extracellular Gln was noted. These data suggest that GABA, Glu, and Asp are released primarily from their transmitter pools during severe hypoglycemia. The releasable pools of Tau and PEA appear to be located in kainate-sensitive striatal neurons. The significance of these results is discussed with regard to the excitotoxic theory of hypoglycemic cell death.

Amino Acids↗

Blockade of N-methyl-D-aspartate-sensitive acidic amino acid receptors inhibits ischemia-induced accumulation of purine catabolites in the rat striatum.

The effect of blocking N-methyl-D-aspartate (NMDA)-sensitive excitatory amino acid (EAA) receptors during brain ischemia was studied in order to test a link between EAAs and neuronal energy metabolism. The receptors were blocked unilaterally in the rat striatum before, during and after an ischemic insult. The receptor blocker, D-2-amino-5-phosphonovalerate (D-APV) was administered by dialysis perfusion, which also allowed continuous sampling for analysis of adenosine triphosphate degradation products, i.e. purine catabolites, in control and D-APV-treated striata. Purine catabolites were analysed with reversed-phase liquid chromatography. Hypoxanthine, xanthine, inosine and adenosine increased dramatically in the striatum during ischemia and reached maximum levels during early reperfusion. D-APV reduced the extracellular accumulation of all measured purine catabolites during ischemia/reflow and improved to some extent the recovery of the striatal electroencephalographic activity in the majority of the animals. The results suggest that NMDA receptor blockade attenuates acute changes in energy metabolism during ischemia.

2-Amino-5-phosphonovalerate↗

Serum deoxythymidine kinase in small cell carcinoma of the lung. Relation to clinical features, prognosis, and other biochemical markers.

Thymidine kinase (s-TK), lactate dehydrogenase (LDH), and carcinoembryonic antigen (CEA) were determined in pretreatment serum from 125 patients with small cell carcinoma of the lung. The distribution of marker levels into three ranges, when including all patients were as follows: s-TK less than 5 units 49%, 5-less than 10 units 25%, greater than or equal to 10 units 26%; LDH less than 6.7 mukat 31%, 6.7-less than 13.4 mukat 48%, greater than or equal to 13.4 mukat 21%; CEA less than 7.5 micrograms/l 51%, 7.5-less than 15 micrograms/l 25%, greater than or equal to 15 micrograms/l 24%. The percentages of patients with limited and with extensive disease within each range were s-TK less than 5 82/18, 5-less than 10 29/71, greater than or equal to 10 9/91; LDH less than 6.7 76/24, 6.7-less than 13.4 51/49, greater than or equal to 13.4 21/79; CEA less than 7.5 70/30, 7.5-less than 15 39/61, greater than or equal to 15 23/77. Analyses in relation to metastases present showed that patients with skeletal and bone marrow metastases had significantly higher s-TK and LDH than those without, while this was not the case for CEA. A strong correlation between s-TK and LDH level, a weaker correlation between CEA and s-TK, and no correlation between CEA and LDH level, was found. Both the level of s-TK and LDH correlated to the patients' performance, as defined by the Karnofsky index. These correlations were mainly confined to the patients with extensive disease. Analyses of the prognostic capacity of variables showed that s-TK, stage, and Karnofsky index could divide the patients into groups with highly significant difference in survival time, while LDH and CEA were of less value. Longitudinal studies showed that the serum markers mirrored the disease activity, with the exception that highly increased s-TK was found during remission induction for some patients. It was concluded that the expression of pathologic levels for the serum markers were dependent on different biological parameters. Of the serum markers, only s-TK was judged useful for estimation of disease spread and prognosis of the individual patient.

Actuarial Analysis↗