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Biomedical subjects

F Colombo

Publications and source records attributed to F Colombo.

At least 73 records · Page 4Linked to original sources
PubMed1985

Reproductive and hormonal factors and breast cancer in a Northern Italian population.

Between January 1980 and March 1983, data were collected to evaluate risk factors for breast cancer in a case-control study based on 368 women with breast cancer admitted to the General Hospital of Pordenone (a district in North Eastern Italy with a particularly high breast cancer mortality rate), and 373 age-matched controls. Nulliparity or low parity, late age at first birth and later menopause were associated with an increased risk of breast cancer. The elevated risk associated with nulliparity could be almost completely explained by marital status, thus pointing to a specific protection given by parity, rather than some putative influence of infertility or subfertility in breast cancer cases. Likewise, risk did not vary materially according to history of abortions when marital status was controlled for. Increased risk associated with later age at first birth, on the other hand, was not accounted for by marital status or parity. The population studied, though frequently multiparous, showed late average at first birth: this might, at least partly, explain its high mortality rate from breast cancer. The risk estimate was higher if menarche occurred below age 15; however, there was no evidence of a trend for the relative risk to rise with lower age at menarche. The use of oral contraceptives or other female hormones (such as oestrogen replacement therapy) did not appear to be related to the risk of breast cancer. The role of the major menstrual and reproductive variables considered (age at menarche, parity, age at first birth) was apparently stronger in pre-menopausal women, thus suggesting an influence of these factors (and possibly, their hormonal correlates) on one of the latter stages of the process of carcinogenesis.

Abortion, Spontaneous↗
PubMed1985

Stereotactic radiosurgery utilizing a linear accelerator.

The authors have developed a radiosurgical technique based on multiple arc irradiations. The target is fixed to the rotational isocenter of a Varian 4 MV linear accelerator. The first irradiation is carried out while the radiating source is rotating on a 100-140 degrees arc. The patient is then rotated around a vertical axis passing through the target, and arc irradiations are repeated in different angular positions. By this technique it is possible to obtain very steep dose gradients at the borders of the target volume. High doses are usually delivered in two shots. 47 patients have been treated so far in a clinical trial that started in November 1982. The paper deals with the preliminary results (more than 6 months' follow-up) obtained in patients affected by nonresectable brain tumors and AVMs.

Adolescent↗
PubMed1985

Ventilatory response to carbon dioxide and to isometric muscle contraction after administration of placebo, propranolol, mepindolol and salbutamol.

Healthy males (23-29 years) volunteered as subjects. We studied the ventilatory response to carbon dioxide and to isometric exercise (50% of maximum voluntary contraction) after administration of propranolol (20 mg), mepindolol (5 mg), salbutamol (20 mg) and placebo (single dose orally). The increase of pulmonary ventilation (VE) activated by central (CO2) and reflex stimulus (hand-grip) did not differ statistically between the four drugs. Analysis of VE in terms of inspiratory drive (Vt/Ti) and timing ratio (Ti/Ttot) showed that during CO2 stimulation mepindolol and salbutamol increased VE predominantly by the increase of Vt/Ti, presumably through the direct stimulation on the respiratory center. During rebreathing, Ti/Ttot increased significantly after administration of placebo and propranolol, so VE increased by a rise of Vt/Ti and by an increase of an effective 'timing component' (Ti/Ttot). Propranolol does not modify the ventilatory response to CO2 and hand-grip when VE is analyzed in terms of Vt/Ti and Ti/Ttot.

Adult↗
PubMed1985

External stereotactic irradiation by linear accelerator.

Stereotactic radiotherapy has two advantages: (a) the possibility of giving high radiation doses to small but spatially well-defined target volumes and (b) the presence of a stepped dose gradient between the target volume and the surrounding healthy tissues. To utilize these advantages, the authors built a new stereotactic head frame by which the intracranial target is fixed to the rotational isocenter of a 4-MV linear accelerator. The collimator openings are selected according to the volume and the three-dimensional configuration of the target, and the radiation dose is based on the radiosensitivity of the lesion. After the patient is fixed to the frame, the radiation source and the patient are rotated so that the target is irradiated through infinite portals distributed over the convexity of the skull. It is thereby possible to obtain very high radiation doses centered into the target with a stepped dose gradient. The preliminary radiodosimetric tests and the operative technique are described. The advantages of this technique compared to interstitial radiotherapy and Leksell's radiosurgery are emphasized. This noninvasive procedure has been used to treat a series of intracranial tumors.

Adolescent↗
PubMed1984

[Biopsy and stereotaxic radiotherapy of cerebral gliomas].

The Authors report their experience on a series of 125 patients that underwent stereotactic biopsy. The procedure has proved reliable and almost risk -free. The diagnosis obtained from the bioptic specimen by smear technique-cytological examination and by paraffin embedding-histological examination are compared. Neuropathologic data were also checked by the examination of the tumor bulk in cases that underwent surgical removal or autoptic verification. The preliminary results obtained in 8 patients with the new technique of external stereotactic irradiation by means of a linear accelerator are also shown.

Biopsy↗
PubMed1984

Preparation and evaluation of [99mTc]DEPE as a cardiac perfusion agent.

Technetium-99m labeled bis(1,2-diethylphosphino)ethane was evaluated as a cardiac perfusion agent in mice, dogs and normal human volunteers. The agent produced as a single cationic compound was prepared by a simple kit type method and had a rapid myocardial uptake in animals. The cardiac uptake of the agent in dogs averaged 4.6% of administered dose and delineated left and right ventricles by in vivo imaging. In dogs with experimental myocardial infarction, the agent was distributed according to the regional myocardial blood flow, had excellent correlation with myocardial distribution of 85Sr microspheres (r = 0.96, 0.93)] and 201Tl (r = 0.91 and 0.83), and enabled us to detect perfusion defects by in vivo scintigraphy. The agent, however, failed to have a useful degree of cardiac uptake in humans.

Animals↗
PubMed1984

Somatosensory-evoked potentials after mesencephalic tractotomy for pain syndromes. Neuroradiologic and clinical correlations.

Eight patients affected by intractable pain underwent stereotactic mesencephalic tractotomy. Recordings of somatosensory-evoked potentials were made before and after the surgical procedure. Localization and size of the obtained lesion were controlled by computed tomography scans. Clinical result was compared with modification of postoperative somatosensory-evoked potentials and with the appearance of the lesion in the computed tomography scans.

Aged↗
PubMed1984

The microsurgical drainage of the varicocele.

A new technique for surgical treatment of primary and recurrent varicocele is proposed. The technique consists of direct anastomosis of two or three dilated veins of the pampiniform plexus with the great saphenous vein. A connection between a high venous pressure region and a lower pressure region is established. Twenty-five patients were operated on, 7 with recurrent varicocele and 18 with primary varicocele. The immediate and long-term results (6 year follow-up) have always been good.

Drainage↗
PubMed1984

A new dynamometric technique to measure and locate endocranial structures. Preliminary report.

An apparatus for measuring and recording the resistance to penetration of endocranial tissue has been planned and built. The probe carrier, driven by a constant-speed electric motor, is fitted onto a stereotactic head frame which is used to guide the tool to the intended target. The displacement and resistance encountered when the tool penetrates intracranial structures are measured and recorded on an x-y recorder. Preliminary tests performed on calf brain specimens have documented that the apparatus can measure the different consistencies of normal cerebral tissue and suggest a new technique for morphological investigations based on the mechanical consistency of normal and pathological organic tissue. Moreover, the hypothesis of a plastic deformation in cerebral tissue has been confirmed, in that the same apparatus permits one to measure the displacement of tissues caused by the advancement of the surgical tool.

Biopsy↗
PubMed1984

High-dose neuroleptics: uncontrolled clinical practice confirms controlled clinical trials.

The strategy of high-dose intramuscular haloperidol as routinely applied in a general hospital psychiatric ward to 74 successive patients, 33 of whom stayed only up to seven days, and a further 34 up to 15 days, led to a complete recovery in only six, and complete lack of change in 23. Adverse reactions were recorded in 42, severe enough to stop treatment in eight; there were three deaths. In view of this risk-benefit analysis, systematic application of this high dose strategy to get a more rapid turnover of patients is unjustified.

Adolescent↗
PubMed1984

Spontaneous intracerebral hematomas: a new proposal about the usefulness and limits of surgical treatment.

We analyzed the volume of 132 spontaneous supratentorial intracerebral hematomas calculated with computed tomographic (CT) scans and related it to the clinical condition of the patients on admission and to the outcome at their discharge from the hospital (1 to 3 months after the ictus). Fifty patients were operated on, and 82 received only medical treatment. In evaluating outcome, we were more interested in survival than its quality. The main problem is the evaluation and treatment of the many patients who are comatose upon admission (about half of the patients). We concluded that surgical treatment by evacuation of the hematoma increases the percentage of survival of comatose patients with a hematoma volume between 26 and 85 ml.

Cerebral Hemorrhage↗
PubMed1984

A multi-centre trial comparing a sulfamethopyrazine/trimethoprim combination with co-trimoxazole in respiratory tract infections.

A double-blind, multi-centre trial was carried out in 72 patients with acute or chronic infections of the lower respiratory tract to compare the efficacy and tolerance of a sulfamethopyrazine (200 mg)/trimethoprim (250 mg) combination with that of the established combination co-trimoxazole (400 mg sulphamethoxazole plus 80 mg trimethoprim). Patients received treatment for 10 days either with 2 capsules of co-trimoxazole twice daily or in the newer combination group with 2 capsules on Day 1 but then only 1 capsule daily for the remainder of the treatment period. The results of clinical, bacteriological and functional tests showed an excellent or good response in over 90% of patients in each group. There was no statistically significant difference in effectiveness of treatment with the once-daily sulfamethopyrazine/trimethoprim regime compared with co-trimoxazole given twice daily, and both treatments were well tolerated, with only a few mild side-effects, mainly gastro-intestinal ones, being reported.

Adolescent↗
PubMed1984

[Stereotaxic irradiation with a linear accelerator].

At least two fundamental requirements must subsist for every stereotaxic radiotherapy treatment: 1) a capacity to administer extremely high doses of radiation to small areas which have been precisely defined in three dimensions; 2) the presence of a steep gradient between adjacent isodose curves so that damage to the tissues close to the target may be reduced to the minimum. The authors have built a special stereotaxic device for the fixing of the head of the patient (together with the chosen intracranial target), once the indispensable neuroradiological evaluations and bioptic controls have been effected, at the isocenter of a linear accelerator (Varian Clinac 4). Once the dimensions of the collimator have been chosen in accordance with the volume and the three dimensional conformation of the target and the dose to be administered has been decided upon in accordance with the histological nature of the lesion, both the linear accelerator and the patient are rotated about the isocenter of the therapy unit. It this way it is possible to reach extremely high dosages with very steep isodose gradients, centered exclusively upon the target ("gamma knife"). The procedure employed is described in full. The dosimetric evaluations which preceded the use of the set-up in clinical practice are illustrated as well. The advantages that this technique offers when compared with interstitial brachytherapy and/or Leksell's radiosurgical procedures are stressed. The described procedure, which is entirely bloodless and thus applicable also to high vascularized lesions, has so far been used in a limited series of cases.

Brain Diseases↗
PubMed1984

Zidometacin: pharmacokinetic study on oral absorption.

Zidometacin is a new nonsteroidal antiinflammatory agent structurally related to indomethacin. Pharmacological studies show its favourable activity/ulcerogenicity ratio in comparison to indomethacin. Preliminary clinical data indicate a good analgesic effect after a single dose and an improvement of functional conditions of the joint after short-term therapy. Pharmacokinetic parameters and bioavailability of the drug were evaluated in the present study after the administration of a single oral dose. Nine healthy volunteers without impairment of hepatic and renal function were selected. According to a 3 X 3 replicated latin square they received a 100 mg capsule, a 200 mg capsule and a 100 mg solution (sodium salt). After various time intervals, blood samples and urines were collected. Plasma and urine levels were evaluated by means of a specific high-performance liquid chromatography method. No difference between plasma levels of capsules (100 mg) and solution (100 mg) was observed. Capsules showed a dose/level relationship between 100 mg and 200 mg. Mean half-lives (+/- s.d.) of capsules (100 and 200 mg) and solution were respectively 3.5 +/- 2.33, 2.8 +/- 1.22, 4.4 +/- 2.96 h. The 0-48 h recovery of total zidometacin (free + conjugated) was 27.4% (100 mg capsule), 20.7% (200 mg capsule) and 24.6% (solution). Only a small amount of zidometacin was excreted unchanged. The drug is well absorbed and its bioavailability appears satisfactory.

Administration, Oral↗
PubMed1983

Lung cancer care in general hospitals.

Diagnostic procedure, therapeutic care and degree of follow-up delivered to 1692 lung cancer patients over 2 years (1978-79) in 31 Italian hospitals were reviewed. The data show marked deficiencies in the various indicators analysed: staging by standard methods was recorded only in 13% of patients; reliable histocytologic classification in 54% of patients. A group of commonly accepted protocols was adopted as first-line therapy only in 49% of treated cases; 19% of patients were regularly followed according to standard programs, whereas 49% had been dropped without any information in the charts. Better performance, although not satisfactory, was found in hospitals with oncologic facilities and wards compared to centers without "ad hoc" organizations. The discussion focussed on the limits of organizational measures and efforts to determine widespread improvement in care for a disease such as lung cancer for which real therapeutic gains are still hard to achieve.

Adult↗