Search PubMed⌕ Search

Biomedical subjects

A Ahonen

Publications and source records attributed to A Ahonen.

At least 55 records · Page 3Linked to original sources
PubMed1991

Inhaled bronchodilator's in asthma: low or high dose?

We studied the effect of regular inhalations of low-dose and high-dose fenoterol and low-dose and high-dose combinations of fenoterol and ipratropium bromide in maintenance treatment of 120 adults with moderately severe asthma. We used a double-blind, randomized, parallel group design comparing 12 weeks of treatment with four regimens: fenoterol, 100 micrograms/dose; fenoterol, 200 micrograms/dose; fenoterol, 50 micrograms; and ipratropium, 20 micrograms/dose in a single inhaler (Berodual) and fenoterol, 100 micrograms and ipratropium, 40 micrograms/dose in a single inhaler (Duovent). During the baseline and active treatment period the patients recorded PEFR in the morning and evening, symptoms and use of a rescue inhaler. Changes in twice daily peak expiratory flow rates or asthma symptoms did not show any significant differences among the four treatment regimens during the 12 weeks compared with the baseline period. Use of the rescue inhaler did not differ among the four groups during the active treatment. The patients' assessment of the efficacy of the active treatment favored the low-dose fenoterol and low-dose combination. More side effects were recorded in the high-dose combination group during the first 4 weeks compared with the other groups. We conclude that in maintenance therapy of chronic asthma high doses of fenoterol alone or in combination with ipratropium bromide offer no clinical advantage over low doses. On the contrary, the low-dose fenoterol and the low-dose combination are better accepted and tolerated by the patients.

Administration, Inhalation↗
PubMed1990

Effects of captopril on blood pressure and respiratory function compared to verapamil in patients with hypertension and asthma.

Seventeen adult patients with moderate and stable bronchial asthma and established essential hypertension (WHO I or II) were evaluated in a randomized, double-blind, crossover study of the effects of captopril (50-100 mg/day) and verapamil (160-240 mg/day) on blood pressure, orthostatic reactions, respiratory function, and asthmatic symptoms. The effect of both drugs on blood pressure was significant. Blood pressure (mean of 161/98 mm Hg initially) decreased to a mean of 147/90 and 160/91 mm Hg on captopril and verapamil, respectively, with normal orthostatic changes. There were no significant differences in forced vital capacity (FVC), forced expiratory volume in 1 s (FEV1), maximal expiratory flow at 50% of FVC (MEF50), or peak expiratory flow (PEF) measurements at the end of each treatment period. The subjective severity of asthma did not change significantly during the trial. No significant cough symptoms were reported on captopril.

Aged↗
PubMed1989

F-18 fluorodeoxyglucose: its potential in differentiating between stress fracture and neoplasia.

F-18 fluorodeoxyglucose (FDG) accumulates into regions of enhanced glucose uptake and metabolism such as the brain, heart, and malignant tumors. The clinical usefulness of this positron-emitting radiopharmaceutical is illustrated in a case where the clinical picture and CT indicated a malignant bone lesion in the clavicle. Histologically a stress fracture was found secondary to chronic strain on the clavicle. On follow-up the lesion's course was benign. Planar imaging with F-18 FDG was performed twice during follow-up, and on both occasions there was no accumulation of radioactivity over the suspicious area, indicating normal glucose consumption. This case demonstrates the differential diagnostic potential of F-18 FDG and shows that clinically useful information may be obtained without a position emission tomograph.

Adolescent↗
PubMed1989

Psychosocial effects of continuous oxygen therapy in hypoxaemic chronic obstructive pulmonary disease patients.

Twenty six hypoxaemic patients with severe and stable chronic obstructive pulmonary disease (COPD) were treated with continuous domiciliary oxygen for a six month period. The patients were evaluated 1, 3 and 6 months after the start of oxygen therapy. In addition to blood gas analysis, 15 coping skills were evaluated by the patient and by the nurse, who also rated the general activity of the patients. Depression was measured by Beck Depression Inventory (BDI) at the start of the trial and after six months' oxygen therapy. The general psychosocial response was meagre; no significant changes were observed in any psychosocial measures. The response was slightly better in younger and less hypoxaemic patients. We conclude that the psychosocial response to oxygen therapy in severely hypoxaemic COPD patients is limited.

Adaptation, Psychological↗
PubMed1988

Fluorodeoxyglucose imaging: a method to assess the proliferative activity of human cancer in vivo. Comparison with DNA flow cytometry in head and neck tumors.

Thirteen patients with malignant head and neck tumors were studied before they were treated with (18F) fluorodeoxyglucose (FDG) imaging and DNA flow cytometry (FCM). The nuclear DNA content and the percentage of proliferative cells (S + G2/M) were compared with the FDG uptake; FDG was retained in the primary tumor and/or neck metastasis in all patients. The accumulation of FDG did not correlate with histologic grade of the tumors, but there was a clear correlation (r = 0.86, P less than 0.001) between the proportion of the cells in S + G2/M phases of the cell cycle and the intensity of FDG accumulation. The uptake of FDG by the tumor also correlated with the percentage of S-phase cells (r = 0.82, P less than 0.001). The result suggests that enhanced glucose metabolism, measured by FDG uptake, is associated with the proliferative activity of the tumor. Thus, imaging with FDG may offer a new method to assess the aggressiveness of human cancer growth in vivo.

Aneuploidy↗
PubMed1988

18F-fluorodeoxyglucose imaging in preoperative diagnosis of thyroid malignancy.

Fourteen human thyroid tumors were studied with 18F-fluorodeoxyglucose (FDG) imaging. The proliferative activity and DNA ploidy of the tumors was assessed by DNA flow cytometry. FDG accumulated in a Hürthle cell carcinoma, an anaplastic carcinoma and a thyroid lymphoma, but only slightly or not at all in the three papillary carcinomas studied. Three of the eight benign tumors also accumulated FDG, but two of these were selected for imaging because of a large number of proliferating cells in DNA flow cytometry. Two carcinomas with increased nuclear DNA content retained FDG, but a histologically benign follicular adenoma with DNA aneuploidy did not. We conclude that in addition to malignant thyroid tumors, histologically benign tumors may also accumulate FDG, and therefore the value of FDG scanning in the preoperative diagnosis of thyroid malignancy is limited.

Adenoma↗
PubMed1988

Evaluation of treatment response to radiotherapy in head and neck cancer with fluorine-18 fluorodeoxyglucose.

Nineteen patients with malignant head and neck tumors were imaged before and during radiation therapy with 18F-2-fluoro-2-deoxy-D-glucose (FDG) to study the effect of radiotherapy (RT) on FDG uptake. All tumor images were FDG-positive before treatment. After RT, a decrement of tumor FDG uptake was found in all but two patients; these were nonradioresponders. There was a significant decrement (p less than 0.001) in uptake ratios after irradiation of 30 +/- 5 Gy among the radioresponsive (CR + PR) but not among the radioresistant (NC + PD) tumors. The administered dose of RT correlated (r = 0.47, p less than 0.05) with the decrement in FDG activity among the CR + PR but not among the NC + PD patients. The biologic half-life of FDG radioactivity in tumor tissue was evaluated by dynamic scintigraphy. A change in the half-life of FDG toward the value observed in normal tissue was associated with treatment response. The results suggest that FDG imaging can be used for follow-up of RT in patients with head and neck cancer.

Deoxy Sugars↗
PubMed1987

Imaging of metastases of thyroid carcinoma with fluorine-18 fluorodeoxyglucose.

Three patients with multiple metastases of thyroid carcinoma were studied with 18F-2-fluoro-2-deoxy-D-glucose (FDG) and iodine-131 (131I) imaging. Metastases that accumulated only FDG, only 131I, or both FDG and 131I could be demonstrated. Metabolic heterogeneity was seen between different metastases in all patients. The accumulation of FDG may also differ between different metastases of the same patient. The uptake of FDG in metastases was shown to increase parallel with their progression. Metastases of thyroid carcinoma that have ceased to accumulate 131I after treatment with radioiodine may still be demonstrated with FDG. Metastases that accumulate FDG, but not 131I, may behave more aggressively than metastases that accumulate 131I, but not FDG.

Adenocarcinoma↗
PubMed1986

Scintigraphy with [18F]2-fluoro-2-deoxy-D-glucose of cancer patients.

Computerized dynamic gamma camera scintigraphy was performed with [18F]2-fluoro-2-deoxy-D-glucose [( 18F]FDG) on 10 patients with different cancers; tumor perfusion was evaluated in four patients with 99mTc-DPD. All tumors were visible in the [18F]FDG scans with tumor-to-tissue image contrast ratios of 1.2-11.7. Tumor perfusion exceeded that of the surrounding normal tissue in three of the four patients studied. Tumor-to-normal tissue [18F]FDG ratios were plotted as a function of the time. Two types of curves emerged: curves showing a linear increase in the ratio and curves showing a constant value for the ratio. These studies show that [18F]FDG can be used for clinical tumor imaging with a gamma camera, and that there appears to be biological differences in tumor uptake of [18F]FDG.

Adult↗
PubMed1985

Multi-score estimation of catecholamine fluorescence for clinical purposes.

Experience accumulated at multi-score semiquantitation of catecholamine fluorescence of glyoxylic acid-treated stretch preparations of human clinical specimens is presented. The methodology and criteria of quantitation are described in detail. For an example, comparison between 3 different methods for analyzing neural-bound noradrenaline in human myocardial tissue in various heart diseases (obtained during the course of cardiac surgery) is presented: Biochemical determination of tissue noradrenaline content multi-score estimation of catecholamine fluorescence of glyoxylic acid-treated stretch preparations microfluorimetric analysis of the same stretch preparations. The results show that the multi-score estimation method gives a reliable concept of the relative amounts of noradrenaline stored in the intrinsic adrenergic nerve net (corresponding closely to the individual and group differences observed at biochemical noradrenaline determination). In addition, possible regional differences, alterations in the structural integrity of the inbuilt intrinsic nerve net, and other structural changes (e.g. pathological catecholamine accumulations) are easily recognized, whereas biochemical estimation cannot give information on structural aspects, which may have important clinical repercussions. Microfluorimetry does not seem suitable for studies on human myocardial specimens for several reasons which are discussed. The method of multi-score estimation of catecholamine fluorescence described and discussed is recommended for other similar and related studies on human clinical materials.

Catecholamines↗
PubMed1984

Imaging of canine cancers with 18F-2-fluoro-2-deoxy-D-glucose (FDG) suggests further applications for cancer imaging in man.

18F-2-fluoro-2-deoxy-D-glucose (FDG) is a novel radiopharmaceutical that has gained much interest as a cancer-seeking agent. In this paper two cases of histologically verified canine cancer, an osteosarcoma and a mammary carcinoma, are presented. After an intravenous bolus injection of FDG, accumulation of radioactivity over the neoplastic lesion was followed with a computer-guided specially collimated gamma camera. Ratios of radioactivity between tumour and control areas at 30 min were 2.8 and 2.2 for the osteosarcoma and the mammary carcinoma, respectively. In the osteosarcoma, which was imaged for 3 h, this ratio remained essentially stable. It is reasonable to assume that FDG will be suitable for cancer imaging in man.

Animals↗
PubMed1983

Relationship between regional pertechnetate cerebral circulation time and EEG in patients with cerebral infarction.

The qualitative and regional correlations between the EEG and the cerebral circulation time (CCT), obtained by using intravenously injected pertechnetate and a multidetector device, were studied in 75 patients with supratentorial cerebral infarction. Because bolus dispersion and changes in systemic circulation may distort absolute CCT values when intravenous injection of the isotope is used, the inter- and intrahemispheric relative CCT values were used as indices of CCT. Overall good correlations could be demonstrated between both inter- and intrahemispheric CCT abnormalities and the EEG, though not in all patients. The number of patients with pathological CCT findings showed a tendency to increase with increasing severity of the EEG abnormality. The number of abnormal CCT areas per patient (indicating the size of the circulation disturbance) also increased significantly with increasing severity of the EEG disturbance. Interestingly, relative 'hypervelocity' areas occurred in fewer patients with normal or clearly disturbed EEGs than in patients with mildly disturbed EEGs, perhaps due to differences in autoregulatory capacity and collateral circulation. Within the EEG focus the relative number of CCT abnormalities was greater than outside it. In spite of this fairly good overall correlation between the EEG focus and the CCT abnormality, more than 10% of the patients with an EEG focus showed no CCT abnormalities, thus indicating the complementary roles of these methods. The present study on cerebral infarction, though using intravenously injected pertechnetate for the CCT measurement, showed a reasonable correspondence with earlier reports on the relationship between the EEG and either the CBF or the CCT (obtained by intra-arterially injected isotope). This would seem to suggest that the used non-invasive method for regional CCT measurement has potential for evaluation of cerebral haemodynamics.

Adult↗