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Biomedical subjects

F Colombo

Publications and source records attributed to F Colombo.

At least 37 records · Page 2Linked to original sources

How informed general practitioners manage mild hypertension: a survey of readers of drug bulletins in 7 countries. International Society of Drug Bulletins (ISDB).

OBJECTIVE: To determine whether general practitioners (GP) who are readers of independent drug bulletins can be used as an international epidemiological observatory of the criteria adopted by "well informed" doctors in various countries in the management of mild hypertension. DESIGN: Questionnaire study of GPs' diagnostic criteria for mild hypertension, routine investigation and management of patients with this diagnosis. PARTICIPANTS: 206 GPs readers of independent drug bulletins in 7 countries, comprising 95 known systematic readers of a local bulletin and 111 randomly selected regular subscribers. MAIN OUTCOME MEASURES: Response rate to the questionnaire. Diagnostic criteria, routine investigations, and treatment used for patients with mild hypertension. RESULTS: The study required two months for planning and implementation. Four countries out of eleven had a response rate < or = 50% and were excluded; the frequency of responses from other countries was 69%. The average diastolic blood pressure (DBP) considered diagnostic of mild hypertension range from 94 mm Hg (lower threshold) to 106 (upper threshold). A minority (17%) of GPs routinely request the minimum recommended laboratory tests to assess patients. GPs routinely advise non-drug measures before starting a drug. Most would not start drug treatment in patients without other risk factors and a DBP below 100 mmHg. The top first choice drugs were diuretics and beta-adrenoceptor blockers. Half of the doctors were able to quote some published guide to the management of mild hypertension, and 18% cited a relevant trial. Attitudes in diagnosing and treating mild hypertension differed widely between GPs and countries. CONCLUSIONS: GP readers of drug bulletins can be used quickly and inexpensively to assess the extent to which recommended diagnostic and therapeutic practices are accepted by "well informed" doctors. The results suggest that attitudes in managing mild hypertension vary widely among GPs and countries and differ remarkably from the recommendations of published guidelines.

Adrenergic beta-Antagonists

99mTc-2GAM: a tracer for renal imaging.

We propose a renal imaging agent, the 99mTc complex of the bidentate-N,S chelate N-(mercaptoacetyl)glycine (99mTc-2GAM), with the imaging characteristics of 99mTc-DMSA but a faster kidney uptake; chemical evidence supports the formulation of 99mTc-2GAM as [Tc(v)(O)(GAM)2]-. After biodistribution and toxicity studies in animals, 99mTc-2GAM was evaluated in five normal volunteers. 99mTc-2GAM is rapidly cleared from the blood (t1/2 = 9 min) and 50% of the ID is excreted in the urine in the first 2 h. Dynamic data show a rapid renal uptake that increases up to 1 h with no significant wash-out between 1 and 8 h. The uptake in each kidney ranges from 11.3% to 20.7% ID. Low, stable liver uptake is observed. No significant activity is detected in other organs. We showed no differences between 99mTc-2GAM and 99mTc-DMSA compared in three patients with unilateral kidney disease. We conclude that 99mTc-2GAM has good practical and dosimetric features for renal imaging.

Adult

[New trends in the surgical treatment of penile carcinoma].

With the current oncological emphasis on radical treatment allied to minimal invasiveness, choice of treatment relies on precise clinical staging. The corpora cavernosa of the penis represent a well defined anatomical structure distinct from the corpus spongiosum and the glans which are tightly connected to one another. In case of primary penile tumour the T.N.M. classification of the American Joint Committee on Cancer includes in the T2 stage both infiltration of the corpus spongiosum and of corpora cavernosa. Jackson's classification seems to be more pertinent as it limits to stage 1 cases involving the glans and corona and classifies as stage 2 cases limited to the corpora cavernosa. Partial penectomy can prove overly invasive, yet insufficiently radical, if the anatomical continuity of the spongious tissue is not considered. Carcinoma of the glandular corpus spongiosum without cavernosal involvement indicates glandulectomy with partial uretrectomy and apical cavernous-urethrostomy. Preserving the corpora cavernosa is an option of great relevance to the quality of life of the patient: erectile ability and stand-up micturition are not affected and the patient keeps complete sexual ability and orgasmic sensation. In case of scrotal or public involvement, emasculation with hemipelvectomy must be attempted; if indicated, it can be followed by radiotherapy. Perineo/abdominal reconstruction can be followed by urinary diversion with adjuvant chemotherapy. In selective cases neophallic reconstruction can be later attempted using the inferior abdominal rectum muscle.

Adult

[Radical surgical treatment of Peironie disease by excision of the plaque and dermal graft allowing conservation of erection].

The surgical treatment of the La Peyronie disease is the complet excision of the fibrom plaque followed by dermal skin grafts. This technique is applied for stabilised cases in which coït has become uneasy due to the deformation of the penis. A complete isolation of the vasculonervous dorsal pedicle guaranties a good erection. In 15 years this technique was applied in 400 cases followed during 2 years. In 7% of cases a recidive of the incurvation occurs. In 20% the erection was unsatisfactory.

Adult

[Seminal obstructions of the inflammatory origin].

Presence of bacteria in the sperm is often associated to a reduction of fertility in relationship with a decrease in number and motility of spermatozoa and with an augmentation of the abnormal spermatic cells. In the most severe cases, chronic and complicated phlogosis may lead to obstruction of seminal pathways with consequent azoospermia. Clinical features of seminal phlogosis are extremely variable both in acute and chronic evolutions. In every case the first diagnostical step is sperm count and seminal complete analysis which can give evidence of phlogistic alteration in quantity and quality of spermatic cells with a typical presence of an excess in white blood cells (leukospermia) as consequence of infection. The great variety in clinical and bacteriological aspects and the particular biological features of the organs involved, as the prostate, makes treatment a difficult problem to solve with particular regard to the choice of an effective antibiotic which pharmacokinetic has to result suitable for the microorganism as well as for the tissue of the infection site. All those efforts are indispensable to reduce the too frequent therapeutical failures in the management of seminal phlogistic pathology with complications of organic but also physiological relevancy for the patient and the partner too, such as azoospermia.

Anti-Bacterial Agents

[Nonsurgical and endoscopic therapy in obstructive azoospermia].

The endoscopic therapy has an elective role in the distal obstructive azoospermia for urogenital carrefour pathologies both organics and functional and differently in the resection and/or aspiration with sperm recovery forms. Resolutely attends to the symptomatology and positively to the fertility re-establishment, in front of a short sickness-rate. The Authors describe the different techniques with relative indications, results and complications. Instead medical therapy has a role in the obstructive above all post infection and post inflammatory lesions prevention. Furthermore propose to oneself the goal to improve the seminal quality by the improvement of the semen fertilization capacity and to reduce the affections symptomatology. Finally concurs with the sperm selection techniques to fertility potential wealth.

Endoscopy

[Carcinoids in emergency surgery].

The authors report their experience of three cases of carcinoids of the gastroenteric tract which required emergency surgery. Two patients presented symptoms of acute appendicitis caused by appendicular carcinoid, whereas the third presented an occlusive syndrome due to ileal carcinoid.

Aged

Antiarrhythmic drug prescription in patients after myocardial infarction in the last decade. Experience of the Gruppo Italiano per lo Studio della Sopravvivenza nell'Infarto miocardico (GISSI).

BACKGROUND: Recent clinical trials have shown increased, rather than decreased, mortality in patients treated with antiarrhythmic drugs after acute myocardial infarction. OBJECTIVE: To determine whether these findings had an impact on prescription of antiarrhythmic drugs after acute myocardial infarction. METHODS: We retrospectively analyzed the class I and III antiarrhythmic prescription data of 38,072 patients with acute myocardial infarction enrolled in three large randomized clinical trials endorsed by a highly representative sample (about 75%) of Italian coronary care units during the last 10 years. The first study was conducted in 1984 to 1985; the second, in 1988 to 1989; the pilot for the third, in 1991; and the third, in 1991 to 1994. RESULTS: Total class I and III antiarrhythmic prescriptions after acute myocardial infarction was halved during the last decade, from 11.9% at discharge and 14.4% at follow-up in 1984 to 1985 to 5.8% and 5.8%, respectively, in 1991 to 1994. The trend was independent of the different distributions in the three studies of the patients' characteristics associated with antiarrhythmic use (ie, age > or = 70 years, anterior acute myocardial infarction, ventricular fibrillation during hospitalization, and Killip class > or = 2 at randomization). The same decreasing trend was observed for each antiarrhythmic drug. The drug most widely used was amiodarone, accounting for about half of the antiarrhythmic prescriptions, followed by mexiletine hydrochloride and propafenone hydrochloride; flecainide acetate was dropped from the prescription list after the publication of the Cardiac Arrhythmia Suppression Trial results. CONCLUSION: The negative results of the recent clinical trials on class I antiarrhythmic drug use after acute myocardial infarction have been rapidly transferred into routine clinical practice in Italy, since the proportion of patients who received class I and III antiarrhythmic drugs after acute myocardial infarction was halved from the early 1980s to the early 1990s.

Aged

Evaluation of linear accelerator radiosurgical techniques using biophysical parameters (NTCP and TCP).

PURPOSE: Several irradiation techniques are compared with regard to normal tissue complication probability and tumor control probability. METHODS AND MATERIALS: Normal tissue complication probability is calculated using a model based on the "critical element architecture." The probability of controlling an inhomogeneously irradiated tumor is calculated using a model that takes into account the heterogeneity of tumors (different radiosensitivity of clonogens within the tumor and the varying number of clonogens among patients with the same kind of tumor). The ratio of tumor control probability to normal tissue complication probability (therapeutic gain factor) at different levels of dose has been used as a score for the analysis of various irradiation techniques. RESULTS: The best irradiation techniques depends on many factors: irradiation genometry, irradiation field size, choice of the reference isodose, and it is dictated by the pathology of the lesions (noninfiltrating radioresistant tumors, infiltrating radioresistant tumors, noninfiltrating radiosensitive tumors, infiltrating radiosensitive tumors, arterovenous malformations). For the irradiation of the artero-venous malformations it is proposed to insert on the supplemental collimator a flattening filter to reduce the probability of inducing a poorly syncronized obliterative effect. CONCLUSION: We propose that for each kind of pathology to be treated radiosurgically, a proper irradiation strategy should be used.

Humans

Systemic and cerebral kinetics of 16 alpha [18F]fluoro-17 beta-estradiol: a ligand for the in vivo assessment of estrogen receptor binding parameters.

Estrogen receptors are expressed in several brain areas of various animal species, and steroid hormones exert physiologic and biochemical effects on the central nervous system. The aim of the present study was to evaluate in female adult rats, the suitability of 16 alpha [18F]fluoro-17 beta-estradiol ([18F]FES), a selective estrogen receptor ligand, for the in vivo assessment of brain estrogen receptors. This was considered to be a preliminary step in evaluating the potential usefulness of [18F]FES for studies of cerebral estrogen receptors with positron emission tomography (PET) in nonhuman primates and human subjects. We evaluated (a) the time course of the metabolic degradation of [18F]FES in blood; (b) the time course of distribution of the tracer in discrete cerebral areas; (c) the inhibitory effect of increasing doses of cold estradiol on cerebral [18F]FES uptake; and (d) the possibility of in vivo quantification of estrogen receptor binding parameters using both equilibrium and dynamic kinetic analyses. We quantified [18F]FES binding to estrogen receptors using both equilibrium and dynamic kinetic analyses. The results of this study indicate that [18F]FES is a suitable tracer for the measurement of estrogen receptors in the pituitary and hypothalamus, using either the equilibrium or the kinetic analysis. However, [18F]FES is inadequate for the in vivo investigation of estrogen binding sites in brain areas with low receptor density, such as the hippocampus.

Animals

Diurnal blood pressure variability in essential hypertension and vascular reactivity to isometric stress.

The present study was designed to assess the hemodynamic conditions, by means of impedance cardiography methods, and the relation existing between vascular reactivity to isometric stress (isometric handgrip test) and the day/night blood pressure variations, estimated by ABPM. Fifty unselected untreated non-obese EEH adult subjects (WHO class I) with a duration of disease not exceeding 3 years were classified as dippers or non-dippers according to commonly accepted criteria. Twenty three normotensive volunteers acted as controls. SBP, DBP, HR, CI and SVRI were assessed at rest and after IHG test. At rest dippers, non-dippers and controls showed comparable CI. SVRI were more enhanced in EEH than in controls and, although not significantly, in non-dippers than in dippers. During IHG all subjects showed a significant rise of SBP, DBP and HR; CI variations were of comparable size in all groups while SVRI increases were not. Non-dippers showed a significant SVRI rise after IHG in comparison with resting values. In dippers and in controls SVRI increment was insignificantly different in comparison with resting values. Non-dippers showed a closest correlation between BP and SVRI rise during IHG while dippers showed a less consistent association. In conclusion, our data suggest that in adults with short duration EEH the existence of non-dipper condition may be unrelated to myocardial hypertrophy. Blunted nocturnal BP fall is associated with vascular hyper-reactivity revealed by a bigger elevation of SVRI during IHG.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult

[Revascularization: light and shadow].

Advances in the knowledge of penile haemodynamics make evidence of two fundamental mechanisms in the physiology of erection: 1) arterial vasodilatation; 2) blockage of venous outflow. Therefore peripheric vasculogenic erectile impotence presents two pathogenetic possibilities: 1) from insufficient arterial flow; 2) from increased venous outflow. It is therefore very important to make the correct diagnosis of the patient with erectile disturbances in order to determine an appropriate therapy. The following examinations are routine tests carried out at our Institution: NPT test, basal and dynamic Doppler-sonography, OOE-OME (evaluation of output obtaining and maintenance erection), basic and dynamic cavernosography, digital angiography, dynamic NMR. After an accurate diagnostic assessment medical treatment can begin, based essentially on the cavernous infusion of vasoactive drugs, in light forms; surgery is resorted to severe cases, or in cases of failure of medical therapy. Proposed operations may be divided into 3 groups: 1) arterio-cavernous by-pass; 2) arterio-arterial by-pass; 3) venous surgery. Since 1978 the successive experiences of the Authors in this field and the better knowledge of penile vascular structures have led to a standardization of the methods used, with partly original techniques (epigastro-dorsal antiflow and orthoflow double by-pass), which, with selective application, have raised the percentage of pulsing anastomoses at 18 months of 82%.

Follow-Up Studies

[Radical surgery and conservation of erection in Peyronie's disease].

The radical surgical option we propose for Peyronie's disease consists in removing the sclero-hyanolitic focus (plaque) and replacing it by an autologous dermal graft taken from the upper outer thigh area. Between 1981 and 1994, we operated 564 patients with Induration penis plastica (IPP), 418 of whom underwent plaque excision and dermal grafting. All could be assessed at two-year follow-up. Two main complications were observed: penile flexure relapse (71 Pts, 17% of cases), and erectile dysfunction with decreased corporal rigidity (84 Pts, 20% of cases). A mild deviation of the penis can occur some months after surgery and it is not due to disease progression (as it should have evolutive characteristics) but is mere scar retraction (44 Pts, 76% of examined relapsed flexures). The degree of this graft retraction is linked to the individual's histologic response and can be due to an idioptic tissular response or to an insufficient size of the patch. In some cases, the post-op penile flexure can result from a progression of disease (14 Pts, 24% of examined relapses flexures) and can be due either to a new "focus" or to an incomplete removal of the previous plaque. As the patient will date the onset of a possible postoperative erectile deficit from the time of the operation, it is advisable to assess preoperatively the real erectile ability of all patients. Furthermore, a post-op impaired erectile response (84 Pts, 20%) could result from a subalbuginear fibrosis of the erectile tissue that leads to a caverno-occlusive dysfunction (60%). In more than 35% of patients we found a psychogenic component, due to post-surgical stress, that involves an adrenergic hypertone with peripherical vasoconstriction. In few cases (4%) the post-op erectile dysfunction is the consequence of peroperative arterial damages that results in hypoaesthesia of the glans (injury of dorsal arteries) or in failure to obtaining corporal rigidity (damage of cavernosal arteries). A review of our experience involving plaque excision and dermal grafting led us to propose this option in case of mechanical disturbance during coitus and when the association of erectile dysfunction can be excluded.

Follow-Up Studies

Cardiac function study in hard metal workers.

The induction of cardiac effects in hard metal workers is uncertain. This study investigates cardiac function of a group of 31 hard metal workers with or without pulmonary disease. The average duration of exposure to cobalt containing dusts was 10.4 years (range 1-30), while the environmental levels of cobalt exposure ranged from 0.09 to 13.6 mg/m3 Co. Cardiac function has been studied by: ECG (electrocardiogram), exercise test (ET), ECG 24 h according to Holter (ECGH), echocardiogram (ECHO) and radionuclide angiocardiography with 99Tc (RNA). The aims of this work were (i) to show the existence of cobalt myocardiopathy in the workers analyzed and, (ii) to find an early indicator of cardiac dysfunction which could be used in the clinical examination of hard metal workers. Within the group of patients with hard metal lung disease, cases of myocardiopathy of doubtful aetiology have been found. The cardiac indexes obtained through RNA show ventricular dysfunction in healthy hard metal workers which could be a manifestation of initial pulmonary artery hypertension or of an early occult cor pulmonale due to an unknown fibrotic lung disease.

Adult

Patterns of care and survival in non small cell lung cancer: 15 years' experience in a general hospital.

BACKGROUND: Transferring results derived from clinical research into practice is particularly difficult in lung cancer where clear indications for treatment are defined only for selected subgroups of patients. Studies on hospital-based lung cancer population could provide data for quantifying this issue. PATIENTS AND METHODS: This was a follow-up study of consecutive, first-diagnosis cases referred to the in-and outpatient cancer clinics of a large italian general hospital between January 1975 and December 1990. Data were collected from medical records and recorded on ad hoc standardized forms. Analysis focused on changes in distribution over time of patient-related characteristics, prevalence of specific treatment strategies and survival of the study population. RESULTS: 1345 primary non small cell lung cancer cases were reviewed and 1125 were fully evaluable. In early stages (510/1125, 45%) only 237 patients actually underwent surgery. In this group surgery increased from 36 to 69% whereas chemotherapy decreased from 58 to 15%. In the advanced group (615/1125, 55%) chemotherapy was the preferred treatment but combined modalities tripled over time (from 4 to 12%). No significant changes in survival were observed within each group over time. CONCLUSION: Despite changes in the therapeutic approaches, mortality from lung cancer does not seem reduced over time. Since the proportion of cases that could potentially benefit from "active" treatments is small, for the large majority of patients a switch in clinical research from a cure to a care-oriented strategy should be considered.

Aged