[Rational and irrational approach to the inotropic agent therapy of heart failure].
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Amrinone↗
Biomedical subjects
F Colombo
Publications and source records attributed to F Colombo.
Validity of stereotactic biopsy as a diagnostic tool.
254 patients affected by intracranial lesions underwent stereotactic biopsy in our department from 1978 to 1986. Target localization was achieved by CT. Multiple biopsy sampling was performed by cup microforceps or sliding cannula. Operative mortality was limited to 2 cases. Definitive tumour diagnosis including type and approximate grading was obtained in 211 (83%) patients. Diagnostic failures have been investigated from the neuroradiological point of view. Failure rate is low in solid tumours with CT homogeneous appearance and clear-cut borders, gradually increases in non homogeneous tumours, necrotic haemorrhagic or cystic, and is high in non classifiable lesions, generally hypodense at CT, with indefinite borders. In the authors opinion the variability of diagnostic retrieval in different types of lesions must be taken into account when proposing stereotactic biopsy.
Biopsy↗
Beta-blockade antagonism of tyramine-induced rise in blood pressure.
The effect beta-adrenoceptor blockade on the pressor response to tyramine has been investigated in 6 healthy volunteers, each submitted to an i.v. tyramine pressor test before and after 7 days of propranolol 40 mg b.d. or indenolol 60 mg o.d. Tyramine was given as i.v. boluses of 1-6 mg, alternating with saline, in a randomized, single blind fashion. Prior to treatment tyramine caused a temporary, dose-dependent increase in systolic and diastolic blood pressure, whilst the heart rate remained unaffected. Both propranolol and indenolol reduced the pressor response to tyramine, as shown by a significant increase in ED15, i.e. the dose of tyramine required to increase systolic blood pressure by 15%.
Adrenergic beta-Antagonists↗
Dosimetric considerations on multiple arc stereotaxic radiotherapy.
The aim of this paper is to present the physical and dosimetrical features of the stereotaxic radiosurgical method already published by the authors. This method concentrates the dose into the stereotaxic target volume, placed at the isocenter of a 4 MV X-ray beam. Computer calculations showed that: 9-17 arcs provide almost spherical dose distributions; the optimal photon beam quality is about 4-6 MV. The angle between adjacent rotation planes is 20-40 degrees and the arcs are 100-160 degrees wide. In this way the dose to healthy tissue is minimized. The dose distribution was experimentally verified both by ionometric and photodensitometric methods. The procedure for dose calculation at isocenter of fields as small as required by the radiotherapist, has been investigated.
Calibration↗
Prevalence of symptoms generally attributed to hypertension or its treatment: study on blood pressure in elderly outpatients (SPAA).
A number of symptoms that appear to be associated with high blood pressure (headache, dizziness, epistaxis, tinnitus, weakness, drowsiness), and are usually regarded as secondary to hypertension or to antihypertensive drug therapy, were studied in 3858 elderly patients, 67.8% of whom were hypertensive. Of the hypertensive patients, 71.2% were under treatment. Headaches and dizziness were significantly more prevalent in the hypertensive than in the normotensive subjects (32.5 versus 27.4% and 41.5 versus 35.3%, respectively; P less than 0.05) and in treated compared with untreated hypertensives (33.3 versus 29.4% and 43.3 versus 37.1%; P less than 0.05). These differences disappeared after statistical correction for 'awareness of hypertension'. In multiple logistic analysis, female sex, age and awareness of hypertension were significantly associated with a higher prevalence of symptoms, whereas hypertension and antihypertensive treatment were not. We conclude that the presence of these symptoms does not constitute a reliable criterion for starting antihypertensive treatment or judging its efficacy.
Aged↗
Cognitive behavioral treatment for obesity; methods, results and consideration after one year's work.
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Adult↗
Feasibility of a large prospective study in general practice: an Italian experience. Gruppo di Studio sulla Pressione Arteriosa nell'Anziano.
A study of blood pressure control in elderly outpatients was carried out with the participation of 444 Italian general practitioners. Of 4096 patients aged 65 years or over who were considered for recruitment, 3959 (96.7%) fulfilled all the criteria of admission and were followed up for 12 months. The findings regarding one of the aims of the study--that is, to assess the feasibility of a large scale trial in general practice--are reported. Most (87%) of the doctors completed the study. Their adherence to the protocol was highly satisfactory, leading to an acceptable quality of work. Patients' compliance was also good; 98.6% (3898) of the patients who had fulfilled the admission criteria agreed to participate in the study, and only 4% (158) dropped out. Both of these observations support the feasibility of carrying out prospective studies in general practice. The creation of networks of general practitioners who are prepared to carry out research in their practices would allow treatment and preventive measures to be studied simply and at low cost in the appropriate setting.
Aged↗
New technique for three-dimensional linear accelerator radiosurgery.
A new method for external stereotactic focal irradiation of three-dimensional irregular target volumes is proposed. In this method the target is irradiated by a linear accelerator set in various angular positions around the isocenter. During the irradiation the target is translated in a direction perpendicular to the beam. By controlling the velocity of the translation it is possible to modify the configuration of therapeutic isodoses so as to make them follow the borders of the target.
Brain Diseases↗
Adenosine modulates the dopaminergic function in the nigro-striatal system by interacting with striatal dopamine dependent adenylate cyclase.
Behavioral and pharmacological evidences suggest that dopaminergic mechanisms in striatum might be counteracted by adenosine or potentiated by its pharmacological antagonists methylxanthines. To test whether adenosine modulation of the dopaminergic function could be, at least in part, due to an interaction at the level of the adenylate cyclase complex, we studied the effects of the adenosine analog R-Phenyl-isopropil-adenosine (R-PIA) on basal and dopamine-sensitive adenylate cyclase in rat striatum. R-PIA, which interacts with both adenosine A1-inhibitory and A2-stimulatory receptors, dose-dependently inhibited the stimulation induced by dopamine, and seemed to utilize the same pool of enzyme linked to dopaminergic D1 receptors. Two experimental approaches leading to supersensitivity of striatal dopaminergic receptors, (i.e., 6-hydroxy-dopamine injection in substantia nigra and reserpine administration) also induced upregulation of adenosine-dependent adenylate cyclase in striatum, and altered R-PIA modulation of dopamine-sensitive adenylate cyclase. Conversely, after subchronic treatment with neuroleptics such as haloperidol or sulpiride, upregulation of 3H-Spiroperidol binding in striatum was not associated with changes of R-PIA dependent adenylate cyclase in this area. It is concluded that adenosine might modulate post-synaptic responses to dopamine via adenosine receptors which functionally interact with dopaminergic D1 receptors in striatum.
Adenosine↗
Linear accelerator radiosurgery of arteriovenous malformations.
Forty-five patients affected by cerebral arteriovenous malformations not suitable to open surgery have been treated by a radiosurgical technique employing a linear accelerator. One-year follow-up angiography is available for 10 cases. Therapeutic effect of focalized irradiation is presented.
Adolescent↗
[Angiodysplasia of the right colon. Angiographic findings in 5 cases].
The authors present five cases of angiodysplasia of the right colon diagnosed by selective arteriography of the superior mesenteric artery. The patients, affected by repeated digestive haemorrhages, underwent angiography after many endoscopic and radiological examinations, all without significative findings. Clinical patterns, methods and angiographic findings are described, together with surgical specimen.
Angiography↗
Development of nonreducible technetium-99m(III) cations as myocardial perfusion imaging agents: initial experience in humans.
A series of 15 nonreducible technetium-99m(III) complexes of formula tr-[99mTcL(Y)2]+ has been prepared by a general synthetic route based on reductive addition of Y to the technetium-99m (99mTc) intermediate [99mTcL(O)]+. In these complexes, selected for potential use as myocardial imaging agents, L represents one of the two tetradentate Schiff base ligands N,N'-ethylenebis(acetylacetone iminato), (en), or N,N'-propylene-1,2-bis(acetylacetone iminato), (pn), while Y represents a monodentate phosphine, phosphite or isonitrile ligand as exemplified by P(CH3)3, P(OCH3)3 and CN-C(CH3)3. Of these 15 complexes, several with octanol/saline partition coefficients in the range 0.04-20 exhibit significant myocardial uptake in rats and dogs. Of these, none exhibit detectable myocardial washout, providing strong support for the hypothesis that myocardial washout occurs only for those 99mTc(III) cations that undergo in vivo reduction to the neutral 99mTc(II) form. Evaluation of the prototypical complex tr-[99mTc(en)(P(CH3)3)2]+ in seven normal volunteers and patients establishes that it is only a mediocre myocardial imaging agent in man.
Animals↗
Episodic secretion of met-enkephalin immunoreactive material in human plasma and CSF.
Plasma and CSF met-enkephalin immunoreactive material (ME-IR) concentrations were measured in 5 subjects at different hours of the day. Within the 24 hrs CSF ME-IR concentrations ranged in the same patient from 20 to 5000 pg/ml. Plasma ME-IR concentrations presented a circadian rhythm with lower values between 4:00 and 8:00 p.m.
Adult↗
Radiosurgery using a 4MV linear accelerator. Technique and radiobiologic implications.
In the authors' technique, the stereotactically localized target is fixed to the isocenter of a 4 MV linear accelerator. The irradiation is carried out along 9-17 non-coplanar arcs distributed on a 160 degrees cylindrical sector. High doses (10-50 Gy) are delivered in one or two sessions. From 1982, 65 patients have been treated (shortest follow-up 6 months). The dose was chosen according to the pathology and to the volume of the lesion. Good clinical results have been obtained in low-grade gliomas, acoustic neuromas, arteriovenous malformations, and other selected types of intracranial lesions. Therapeutic effects in terms of clinical condition and size of the lesions have been plotted in relation to time elapsed and dose employed.
Adolescent↗
[A correct morphological and structural classification of biliary calculi].
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Bile Pigments↗
Osteogenic osteosarcoma of the calvaria following radiotherapy for cerebellar astrocytoma: report of a case in childhood.
Sarcoma as a second malignant neoplasm following radiotherapy is a rare occurrence in childhood. A case of osteogenic osteosarcoma of temporoparietal bone that developed 56 months after irradiation for a cerebellar astrocytoma in a 10-year-old child is reported and the pertinent literature is briefly reviewed. The possibility of an association (in the same patient) between these two rather uncommon lesions is extremely unlikely. Therefore, it is possible that radiotherapy played a role in the induction of the sarcoma. The indolent course of the latter is stressed.
Astrocytoma↗