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Biomedical subjects

S Eriksson

Publications and source records attributed to S Eriksson.

At least 361 records · Page 20Linked to original sources

Risk of recurrent stroke, myocardial infarction and epilepsy during long-term follow-up after stroke.

The risk of recurrent stroke, myocardial infarction and epilepsy was analyzed in a population-based cohort of 409 stroke patients (mean age 72 years) observed for 3.5-7 years. As assessed by the life table technique, the proportion of survivors in the cohort was 69 +/- 5% at 1 year and 38 +/- 7% at 5 years. During the first year, the risk for recurrent stroke was 14 +/- 4%, and the accumulated risk for stroke recurrence at 5 years was 37 +/- 10%. The probability for myocardial infarction was estimated to be 7 +/- 3% at 1 year and 19 +/- 8% at 5 years. The risk of recurrent stroke was enhanced in patients of high age and with a history of cardiac failure (p less than 0.05), whereas the risk of myocardial infarction was associated with high age, angina pectoris and diabetes mellitus (p less than 0.05). The risk of epilepsy was 3 +/- 2% at 1 year and 5 +/- 4% at 5 years. The considerable risk of recurrent stroke, myocardial infarction and epilepsy adds to the sequelae of the initial cerebrovascular accident.

Aged↗

Endocrine cells in the human oxyntic mucosa. A histochemical study.

The oxyntic mucosa of the human stomach harbors at least five different endocrine cell types (ECL cells, A-like or X cells, somatostatin cells (D), enterochromaffin (EC) cells, and D1 or P cells). Little is known about their functional roles, and of the hormones they produce only somatostatin has been identified. The relative frequency and regional distribution of the different endocrine cell populations were studied in 13 adults with no manifest gastrointestinal disease. From each of them at least three biopsy specimens were taken at seven fixed locations within the oxyntic mucosa. The specimens were examined for the different endocrine cell types by means of immunocytochemistry (staining with antisera against chromogranin A,5-hydroxytryptamine, and somatostatin) and silver staining techniques (demonstration of argyrophil cells by the methods of Grimelius or Sevier-Munger). Chromogranin-positive cells included all endocrine cells identified by the other staining techniques. Grimelius-positive cells included all endocrine cells except the somatostatin cells. Sevier-Munger-positive cells, finally, included the ECL cells and the EC cells. The frequency of ECL cells could be calculated by subtracting the number of EC cells from the number of Sevier-Munger-positive cells. The ECL cells represented 35% of the total endocrine number, somatostatin cells 26%, and EC cells 25%. The remaining 14% consisted of A-like cells, D1 cells, and P cells. Generally, the endocrine cells predominated in the basal portion of the glands, but the various populations of endocrine cells were not uniformly distributed in the various regions of the oxyntic mucosa. However, representative specimens could be obtained from the main body of the stomach, and the results indicate that the examination of a fairly small number of specimens from the main body of the stomach may be sufficient for assessing the frequency of endocrine cells in the oxyntic mucosa of individual patients.

Adult↗

Hydroxyurea-induced cell death as related to cell cycle in mouse and human T-lymphoma cells.

The association between DNA precursor synthesis, cell cycle perturbations, and cell death caused by the anticancer drug hydroxyurea was investigated in mouse and human T-lymphoma cells. Hydroxyurea inhibits the enzyme ribonucleotide reductase, leading to decreased deoxyribo nucleoside triphosphate pools and an accumulation of cells in early S-phase of the cell cycle. We wished to clarify the mechanism of cell death caused by hydroxyurea in concentrations that can be obtained therapeutically. At a 60-microM concentration of the drug, giving 25% growth inhibition during 24 h, no increase in the number of dead cells was observed as determined by cell flow calculations and density gradient centrifugation. However, the removal of hydroxyurea led to 10-30% cell loss during the following 12-h period. In parallel, there was an increase in DNA precursor levels and a rapid progression of cells through S- and G2 phases of the cell cycle. The isolated dead cells showed no overrepresentation of any cell cycle phase. The results demonstrate that, although the toxic effects of low concentrations of hydroxyurea are minimal, the drug-induced unbalanced growth state can cause substantial cell death during a posttreatment period.

Animals↗

Gradient of arginine vasopressin concentration but not angiotensin II concentration between cerebrospinal fluid of anterior 3rd ventricle and cisterna magna in dogs.

Dogs were chronically implanted with two devices for cerebrospinal fluid (CSF) sampling from (a) the anterior part of the 3rd ventricle and (b) the cisterna magna. In conscious dogs arginine vasopressin (AVP) concentration of CSF samples collected at different occasions were 2-3 times higher in the CSF of the 3rd ventricle as compared to the AVP concentration of the cisterna magna. Inhalation anesthesia stimulated AVP release into the CSF at both sites by a factor of about 2, the gradient between 3rd ventricle and cisterna magna CSF of 2-3 remained for AVP in simultaneously collected samples. In contrast, angiotensin II-like immunoreactivity of CSF was not significantly different at both sites, neither in the conscious dogs nor during anesthesia. It is concluded that the main amount of AVP enters the CSF at the 3rd ventricular level.

Angiotensin II↗

Separation of DNA restriction fragments by ion-exchange chromatography on FPLC columns Mono P and Mono Q.

Separation of DNA restriction fragments by FPLC ion-exchange chromatography on Mono Q and Mono P columns was investigated. The columns were found to be particularly suitable for the separation of fragments up to 500-600 bp long. Larger fragments can also be separated although less effectively. We found the following practical working ranges for the parameters investigated: pH, 4 to 11; flow rate, 0.05 to 0.6 ml/min corresponding to separation times between 2 and 20 h. (better resolution is achieved at lower flow rates); gradient slope; between 0.5 mM eluting salt/ml buffer and over 5 mM/ml (better resolution is achieved at lower gradient slopes; eluting ionic strength was found to be independent of gradient slope); gradient composition, chloride salts of smaller monovalent cations eluted the DNA at lower ionic strengths but separations obtained were similar; additives, substances such as urea, formamide, and EDTA can be added without chromatographic effects; sample amount: amounts from 2.5 to 200 micrograms were applied, corresponding to single peak content of from 42 ng to 74 micrograms DNA. Yields were generally over 90% and the chromatographed DNA was fully accessible to restriction enzyme cleavage. Separations occurred predominantly according to DNA size, but AT-rich fragments were retarded in a predictable way.

Chromatography, High Pressure Liquid↗

Deoxyribonucleoside triphosphate metabolism and the mammalian cell cycle. Effects of hydroxyurea on mutant and wild-type mouse S49 T-lymphoma cells.

DNA precursor synthesis can be blocked specifically by the drug hydroxyurea (HU) which has therefore been used for anticancer therapy. High concentrations of HU, however, affect other processes than DNA synthesis; nevertheless, most studies on the biological action of HU have been made with concentrations at least one order of magnitude higher than those needed for cell-growth inhibition. In this study we characterized the effects of low concentrations of HU (i.e. concentrations leading to 50% inhibition of cell growth in 72 h) on cell cycle kinetics and nucleotide pools in mouse S49 cells with various defined alterations in DNA precursor synthesis. The effect of 50 microM HU on deoxyribonucleoside triphosphate pools was a 2-3-fold decrease in the dATP and dGTP pools, with no change in the dCTP pool and a certain increase in the dTTP pool. Addition of deoxycytidine or thymidine led to a partial reversal of the growth inhibition and cell-cycle perturbation caused by HU, and was accompanied by an increased level of the deoxyribonucleoside triphosphates. Addition of purine deoxyribonucleoside gave no protection, indicating that salvage of these nucleosides could not supply precursors for DNA synthesis in T-lymphoma cells. We observed a higher sensitivity to HU of cells lacking purine nucleoside phosphorylase or with a ribonucleotide reductase with altered allosteric regulation. Cells lacking thymidine kinase or deoxycytidine kinase were just as sensitive as wild-type cells.

Animals↗

Clinical profiles of cerebrovascular disorders in a population-based patient sample.

Clinical features of different types of stroke were investigated in a sample of 409 patients representative of all cases admitted for acute stroke, except subarachnoidal hemorrhages, within a well defined population. A specific cerebrovascular diagnosis was obtained by detailed clinical investigation, including CT scan. In people greater than 50 years old, men/women risk for stroke was estimated to be 1.40:1. The risk was higher in men up to the age of 80; above this age similar risk for the two genders was observed. Eleven per cent had intracerebral hemorrhage, 13% TIA, 51% non-embolic and 25% embolic brain infarction. In all diagnostic categories there were similar proportions of patients who had a history of hypertension and previous stroke, neither did hemoglobin and hematocrit levels differ between the different stroke disorders. TIA preceded intracerebral hemorrhage in 11% and brain infarction in 15-20%. As opposed to patients with ischemic lesions, subjects with intracerebral hemorrhage had higher systolic blood pressure levels and more severe symptoms on admission to hospital. Ischemic stroke was associated with male predominance, different ischemic manifestations of heart diseases and diabetes.

Age Factors↗

The adherence of polymorphonuclear leucocytes to an albumin-coated glass surface. Effects of therapeutic concentrations of the Catharantus derivatives vincristine, vinblastine and vindesine.

The Catharantus derivatives are microtubule antagonists employed in immunosuppression and chemotherapy of neoplasms. The role of cytoplasmic microtubules in polymorphonuclear leucocyte (PMN) adherence was studied by means of therapeutic concentrations of the Catharantus derivatives vincristine, vinblastine and vindesine. PMN adherence was measured as retention on an albumin-coated glass surface. PMN adherence was reduced by 4-54% by the Catharantus derivatives, as compared with control values. The suppression of adherence was statistically significant. Since the Catharantus derivatives are microtubule antagonists, it is reasonable to assume that PMN adherence is a partially microtubule-dependent process. It is suggested that reduction of PMN adherence could account for at least part of the immunosuppressive properties of the Catharantus derivatives.

Cell Adhesion↗

Determinants of long-term mortality after stroke.

Risk factors of death for a population of 409 patients with well-defined cerebrovascular disease (patients with subarachnoidal hemorrhage excluded) admitted to the Stroke Unit were studied with the aid of the life table technique, log rank test, and multivariate analysis with BMDP's program for regression on the survival curves with Cox's proportional hazard model. The estimated proportion of survivors was 77% after three months, 69% after one year, and 32% after five years. Patients with intracerebral hemorrhage and embolic cerebral infarction had the worst outcome. Impaired consciousness on admission was the most important risk factor of death followed by high age, previous cardiac failure, diabetes mellitus and male sex.

Adult↗

Cardiac stimulation threshold in familial amyloidosis with polyneuropathy.

It has been suggested that a higher cardiac stimulation threshold reduces the applicability of pacemaker therapy in cardiac amyloidosis. We therefore reviewed threshold data in patients with familial amyloidosis with polyneuropathy (FAP), which is an inherited type of systemic amyloidosis, invariably involving the heart. Fourteen FAP patients treated with a pacemaker were studied. The mean (+/- SD) voltage stimulation threshold during implantation was 1.0 +/- 0.5 V, and noninvasive follow-up 6 months later revealed a mean Vario threshold of 1.9 +/- 0.5 V. Beyond this time, the threshold tended to be stable, and high threshold exit block did not occur in any patient. Several FAP patients did show a moderately elevated threshold, and a multiprogrammable pulse generator with a high output capability is recommended when pacemaker therapy is considered in these patients.

Adult↗

Interaction of changes in the third ventricular CSF tonicity, central and systemic AVP concentrations and water intake.

Arginine vasopressin (AVP) is assumed to be involved as a central transmitter or modulator in the control of autonomic functions including thirst. In conscious dogs AVP concentration in cerebrospinal fluid (CSF) from the anterior part of the third ventricle (A3V) was analysed before and after local elevation of CSF osmolality by intracerebroventricular (i.c.v.) infusion of 0.35 M NaCl and after i.c.v. AVP infusion at 46 and 138 fmol ml-1 for 10 min. In addition, the effects of these i.c.v. infusions on water intake, plasma AVP concentration and blood pressure were investigated. In euhydrated dogs 0.35 M NaCl i.c.v. did not alter AVP concentration in the CSF during the subsequent 2 h. In contrast, plasma AVP concentration had increased significantly from 3.4 +/- 0.3 (control) to 6.4 +/- 0.7 and 4.7 +/- 0.3 fmol ml-1, 4 and 16 min, respectively, after the hypertonic stimulus. Drinking was stimulated with an average water intake of 14.5 +/- 3.7 ml kg-1 body wt. However, AVP infusion into the A3V did not elicit water intake despite increases of AVP concentration in the A3V by factors up to 40 above control. The same animals responded with spontaneous drinking to 0.35 M NaCl i.c.v. administered 160 min after the end of AVP infusions. Exogenously administered AVP disappeared from the A3V with a time constant of 13.8 min. The results do not support the view that AVP in the A3V CSF per se stimulates drinking.

Animals↗

Changes in cerebral perfusion after acute head injury: comparison of CT with Tc-99m HM-PAO SPECT.

Technetium-99m hexamethylpropyleneamine oxime (Tc-99m HM-PAO) was successfully used with single photon emission computed tomography (SPECT) on fourteen comatose patients who had acute head injuries. The SPECT scans were correlated with computed tomography (CT) scans obtained within 24 hours of the injury. Tc-99m HM-PAO SPECT was shown to have the following advantages: It reflected perfusion changes, was more sensitive than CT in demonstrating more lesions, and demonstrated lesions at an earlier stage than those demonstrated with CT. Different types of lesions, as evidenced by cerebral perfusion changes, have been described and categorized. The lesions that had a favorable prognosis could be separated from those with an unfavorable prognosis on the basis of the findings of Tc-99m HM-PAO SPECT.

Accidental Falls↗

Doxycycline effects on the adherence of polymorphonuclear leukocytes to an albumin-coated glass surface.

The effect of doxycycline on polymorphonuclear leukocyte (PMN) adherence to albumin-coated glass surfaces was studied in the absence and presence of the chemotactic peptide FMLP. Three concentrations of doxycycline were studied, one subtherapeutic (0.1 micrograms/ml), one therapeutic (1.0 micrograms/ml) and one supertherapeutic (10 micrograms/ml). PMN adherence was maximal after incubation for 5 min. FMLP did not affect PMN adherence in the present assay system and at the concentration studied (10(-7)M). PMN adherence remained stable and unaffected in the tested doxycycline concentrations. Thus, the present study could not confirm the reported and challenged doxycycline inhibition of PMN adherence.

Albumins↗

Alpha 1-antitrypsin deficiency and liver cirrhosis in adults. An analysis of 35 Swedish autopsied cases.

alpha 1-Antitrypsin (AAT) deficiency in adults predisposes to lung and liver disease, but its natural history is incompletely known. To better characterize the liver disease, all known deceased adult Swedish patients known to us with homozygous (PiZZ) AAT-deficiency, who had undergone autopsy during the 20-year period 1963-82 were reviewed. Of 94 such patients, 35 had cirrhosis (27 males and eight females) with a mean age at death of 65.5 +/- 10.5 (SD) years compared to 53.6 +/- 12.8 years (p less than 0.01) for the 59 non-cirrhotic patients. The longer survival suggests less severe lung disease in the cirrhotic group. Clinically these patients most frequently presented with ascites or other signs of portal hypertension. Evidence of alcohol overconsumption, chronic viral hepatitis, or autoimmune disease was rare. Aside from low plasma AAT levels, laboratory and other clinical features were indistinguishable from those of decompensated cirrhosis of any etiology. The prognosis was generally grave with a mean survival of two years after diagnosis. Fourteen of the 35 cirrhotics (10 males and four females) had primary liver cancer (PLC) at autopsy. We conclude that cirrhosis and PLC are more frequent complications in elderly patients with AAT-deficiency than was previously known. These complications had a marked male predominance.

Aged↗