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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
PubMed1991

[Venous leakage and role of the suspensory ligament of the penis: anatomo-surgical observations and therapeutic suggestions].

From April 1988 to October 1990 we treated 80 patients by D.D.V. ligation and successive tightening of the cavernous bodies with simultaneous corporo-pubic suspension with four non-absorbable dorsal stiches. In 58 of them, further ligation have not been necessary; the remaining 22 patients had also to be treated with cavernous crura ligation (16 Pts.) and Urettiro-glandular lysis (6 Pts.). The immediate post-operative functional success (satisfactory sexual intercourse), in the first group, was 88%, in the second one was 80%. The 12-months follow up (50 Pts.) has shown a success rate of 77.5. In the technique we propose (corporo-tightening and pubic suspension - C.T.P.S.) there are two advantages: the reduction of the cavernous outflow and the improvement of the erection angle, making coitus easier.

Adult↗
PubMed1991

[Injuries of the urethra and corpora cavernosa].

Authors present a synthetic review on the etiopathogenetic classification of the posttraumatic urethral and cavernosal pathology. Furthermore they propose the current therapeutic assessment adopted at the Institute of Urology of Milan, both in case of urgent management and for elective treatment.

Drainage↗
PubMed1990

Beta-TG and plasma catecholamines levels after sympathetic stimuli in hypertensives and patients with peripheral vascular disease.

The influence of the sympathetic nervous system on platelet functions in vivo is still controversial. The aims of our study were to compare the response to various sympathetic stimuli in normal subjects and in patients with essential hypertension (HT) or peripheral vascular disease (PVD) and to evaluate any correlations among plasma levels of catecholamines, beta-thromboglobulin (beta-TG) and platelet factor 4 (PF4). In basal conditions beta-TG and PF4 values in the HT patients were higher than those observed in the controls of the same age but lower than those of the PVD patients. Although the different sympathetic stimuli (90 degrees tilting, handgrip, treadmill test, bicycle test) caused a significant increase of the plasma epinephrine (E) and norepinephrine (NE) levels, they did not modify the beta-TG and PF4 levels in any of the groups studied. The platelet activation indices, therefore, regardless of the basal values, do not seem to be influenced by sympathetic stimulation.

Adult↗
PubMed1990

Combined radiosurgery and external radiotherapy of intracranial germinomas.

Germinomas are successfully treated with radiation therapy; we have observed six cases that have been stereotactically irradiated by means of a linear accelerator (radiosurgery). In most cases a single dose of stereotactic irradiation effects the reduction of the tumor volume in a few days. External whole brain and, in two cases, spinal irradiation completed the treatment to avoid seeding of tumor cells. The technique and the advantages of this original therapeutical approach to intracranial germinomas are described and discussed.

Adolescent↗
PubMed1990

99mTc complexes of alpha,alpha-disubstituted, alpha-hydroxy carboxylic acids.

99mTc complexes of 2-ethyl-2-hydrobutyric acid, 2-hydroxyisobutyric acid and (+)- and (-)-citramalic acid are readily prepared in high yield and high purity by reduction of 99mTcO4- in the presence of excess ligand. The resulting agents are very stable in vitro, but can undergo some decomposition during chromatographic analysis unless appropriate precautions are taken. Biodistribution studies in rats and dogs show that these new 99mTc agents accumulate primarily in the kidney and urinary bladder.

Animals↗
PubMed1990

Linear accelerator radiosurgery of three-dimensional irregular targets.

Current radiosurgical techniques allow concentration of radiation from external sources into spherical targets. Nonspherical target volumes require a modification of the irradiation technique. Moreover, isodose shaping is sometimes necessary to spare nearby important radiosensitive structures. To meet these prerequisites we have introduced some technical refinements: (1) computer-controlled rectilinear translations of the target in combination with different angular positions of the source and (2) computer-controlled rotations of the target around a vertical axis in combination with different angular positions of the source. The first solution has proven efficient for treating irregular targets, while the second one was employed for focusing the radiation dose inside volumes obtained by rotation of ellipses.

Brain Neoplasms↗
PubMed1990

Modulation of urokinase receptors on human synovial cells and osteoarthritic chondrocytes by diacetylrhein.

On the basis of both 125I-labelled urokinase-like plasminogen activator binding analysis and transmission electron microscopy of an urokinase-gold complex, we have shown the presence of specific receptors for human urokinase on the cell membrane of human synovial cells. By radio-ligand binding experiments we have shown the existence of similar receptors on the surface of human chondrocytes. In both cases the specific binding is attributable to interaction between the receptor and the A chain of the ligand, as previously shown in other cell model systems. Treatment of synoviocytes with 1,8-diacetoxy-anthraquinone-3-carboxylic acid (diacetylrhein) is able to reduce the number of surface urokinase receptors. At the same time the drug can reduce the fibrinolytic activity released into the culture medium of human synovial cells. Preliminary data indicate that chondrocytes from osteoarthritic patients have a larger number of urokinase receptors than chondrocytes of normal patients. Diacetylrhein can restore the receptor number to normal levels; the amount of urokinase in the synovial fluid of ostroarthritic patients is also reduced. We conclude that the use of this drug has the chance to significantly modify the natural history of osteoarthritis.

Anthraquinones↗
PubMed1990

[Cardiovascular reactivity to isometric stress in patients with stable and borderline hypertension and in normotensive subjects. Effects of alpha sympatholytics and beta blocking agents].

Aim of the study was to evaluate blood pressure (BP) and heart rate (HR) variability during isometric handgrip test (IHT) in 20 ambulant non-obese male adults affected by sustained hypertension (SH) WHO I and II, 20 borderline hypertensive (BH) and 20 normotensives (C) of comparable sex, age and BMI. SBP and DBP were assessed by "Random Zero" sphygmomanometer, HR by ECG registration. IHT was performed at 30% of maximal effort for 3 min. IHT was carried out: 1) after 7 days placebo, 2) after 7 days propranolol treatment (80 mg/day) and, following 10 days wash-out, 3) after 7 days prazosin treatment (0.5 mg/day). After placebo IHT caused increases of SBP, DBP and HR values insignificantly different in the 3 groups. After propranolol IHT induced significantly more elevated SBP and DBP increases in SH than in BH or in C. These increases were significantly more elevated in comparison with those observed, in advance, in the same group of SH subjects after placebo. After prazosin treatment SBP increase induced by IHT was, on the contrary, significantly more elevated in BH than in SH or in C. This increase is more significant in comparison with that observed in the same BH group after placebo treatment. As for DBP variations induced by IHT after alpha sympatholytic therapy we have observed that SH subjects show significantly lesser diastolic variations as compared with those obtained in BH or in C groups after this treatment. In conclusion, enhanced IHT induced SBP elevation after propranolol and dampened DBP reactivity after prazosin suggest an overriding alpha stimulation in SH subjects. SBP hyperreactivity induced by IHT after alpha sympatholytic treatment and DBP hyporeactivity after betablockers emphasize the role of beta stimulation in BH individuals. Inhibition of BP reactivity to IHT in C after prazosin suggest that this one is mediated by alpha adrenergic receptors.

Adult↗
PubMed1989

Biodistribution of Tc-99m methoxy-isobutyl-isonitrile (MIBI) in humans.

Hexakis (methoxyisobutilisonitrile) technetium(I), 99mTc-MIBI, has been proposed for myocardial perfusion studies. We have evaluated the biodistribution of this new agent in normal volunteers at rest and after stress. The biodistribution of 99mTc-MIBI is characterized by rapid blood clearance and a consequently early myocardial uptake. The initial intense hepatic activity is cleared into the gallbladder at 1 h after injection, and the best target to non target ratio is observed at 60-90 min after injection. Absorbed radiation dose calculations show that the thyroid is the critical target organ (230 mRad/mCi at rest), presumably because of 99mTc-pertechnetate generated in vivo. Our results indicate that 99mTc-MIBI is a promising tracer for myocardial perfusion imaging.

Adult↗
PubMed1989

Effects of tetroxoprim and sulfadiazine on T lymphocyte proliferation and gamma-interferon production.

The in vitro effects exerted by tetroxoprim and sulfadiazine on T lymphocyte proliferation were evaluated at drug concentrations equal to and twice the plasmatic peak level of each drug. The two drugs did not exert any significant effect on spontaneous and mitogen (PHA) or monoclonal antibody (MAb anti-CD3) induced T lymphocyte proliferation at the studied concentrations, both when tested separately and combined. In addition the two compounds did not significantly interfere in gamma-interferon (IFN-gamma) production.

Adult↗
PubMed1989

Low-grade astrocytomas: treatment with unconventionally fractionated external beam stereotactic radiation therapy.

Fourteen patients with nonoperable low-grade astrocytomas were treated with unconventionally fractionated stereotactic radiation therapy. The target volume was defined with computed tomography (CT) performed under stereotactic conditions. The treatment was carried out with a technique producing multiple noncoplanar arc irradiation, with the center of the target volume placed at the isocenter of the linear accelerator. A total dose of 16-50 Gy was administered in either one fraction or two fractions 8 days apart. The concentration of dose within the target volume allowed reduction of dose absorbed by adjacent critical structures of the intact brain. Patients were followed up for 11-48 months. Twelve of 14 patients had a partial or complete response to treatment, as demonstrated by CT. Stereotactic radiation therapy appears to be effective in the control of small radioresistant cerebral neoplasms, without damaging surrounding healthy tissues.

Adolescent↗
PubMed1989

Linear accelerator radiosurgery of cerebral arteriovenous malformations.

A technique for linear accelerator radiosurgery has been used in clinical practice since 1982. The technique is based on multiple intersecting arc irradiations focused on a stereotactic target. From November 1984 to October 1988, 97 patients with cerebral arteriovenous malformations have been treated. Seventy-nine patients suffered one or more than one hemorrhage. Four patients had progressive neurological symptoms. In 14 patients, epilepsy was the principal complaint. Stereotactic localization was performed by stereotactic angiography. Lesion dimensions varied from 4 to 40 mm in diameter. Doses from 18.7 to 40 Gy were delivered in one or two sessions. Mean follow-up is 17.1 months (from 1 to 49). Four instances of minor rebleeding were observed after treatment; 3 patients complained of transient neurological deterioration. Of 56 patients who were followed longer than 1 year, 50 underwent 12-month follow-up angiography. In 26 patients complete obliteration of the malformation was demonstrated (52%), in 12 patients subtotal obliteration was obtained (24%), in 11 patients the obliteration was evident but not significant (22%), and in 1 patient the AVM was unchanged. Other angiographic features in incompletely obliterated cases were a significant reduction of flow velocity through the malformation together with a reduction in diameter of both feeding arteries and draining veins.

Adolescent↗
PubMed1989

Antihypertensive treatment of the elderly in general practice.

In order to assess the antihypertensive care received by the elderly, where clear therapeutic guidelines are lacking, a population of 3,858 aged over 64 years was studied. Data were derived from a large Italian 'Study on Blood Pressure in the Elderly', carried out in general practice. Over 90% of the 2,059 known hypertensive patients were receiving drug treatment, with no age or sex-related differences. A single drug was prescribed to 50.2% of treated patients; only 5.5% were receiving three or more drugs. Diuretics and older sympatholytic agents were by far the most frequently prescribed categories, with four drugs (hydrochlorothiazide, amiloride, methyldopa and chlorthalidone) accounting for over 50% of all prescriptions. Low-dosage treatment schedules were frequently used, often associated with less-often-than-daily drug administration. Our study shows that physicians' attitudes to the treatment of arterial hypertension in the elderly are fairly uniform, with treatment of all subjects but with low drug dosages.

Aged↗
PubMed1989

Cardiovascular responses to physical exercise and tyramine infusion in hypertensive and normotensive subjects.

The aim of our investigation was to assess blood pressure and heart rate variations in 20 essential hypertensive male in-patients (WHO class I and II) and in 20 normotensive healthy volunteers submitted to three provocation tests: isometric handgrip (IHG), bicycle ergometric exercise (BEE) and tyramine infusion (TI) given as i.v. boluses alternating with saline in a single-blind fashion. According to our data IHG induced a comparable rise of systolic BP, diastolic BP and heart rate both in hypertensive and normotensive subjects. BEE, compared with IHG, caused a more significant (P less than 0.01) rise in SBP and heart rate in both groups. By contrast, DBP during BEE was significantly increased in hypertensive (P less than 0.01), but slightly decreased in normotensive subjects (P = NS). TI caused a dose dependent SBP rise in both groups studied, while DBP and HR were unaffected. BP elevation was, however, more marked in hypertensive subjects. Confirming this finding significantly lower tyramine doses were required to produce the same SBP increase in hypertensives than in the normotensive volunteers. In short, SBP rise during TI and DBP rise during BEE may be the markers of an enhanced cardiovascular reactivity of hypertensive subjects. Our study suggests that BP reactivity to stress may be different according to the laboratory stress employed and also that BEE and TI are more useful than IHG for the assessment of an enhanced cardiovascular response to stress in hypertensive subjects.

Adult↗