Biomedical subjects

E Colombo

Publications and source records attributed to E Colombo.

At least 73 records · Page 4Linked to original sources

PubMed1994

[Atypical radiological images in Pneumocystis carinii infection in HIV-positive patients].

To assess the prevalence of atypical PCP patterns in AIDS patients, the chest films of 300 patients with clinical and laboratory diagnosis of PCP were reviewed. We considered as atypical patterns the finding of an asymmetric lesion, the involvement of apical regions, pleural effusion, hilar and/or mediastinal lymphadenopathy, parenchymal nodules and pneumatoceles. In some patients more than one of these patterns was found. Atypical patterns were observed in 32% of cases and consisted of: unilateral involvement in 11% of cases, apical involvement in 6%, pleural effusion in 9%, hilar and/or mediastinal lymph nodes in 4%, parenchymal nodules in 6% and finally pneumatocele in 12% of cases.

AIDS-Related Complex↗

PubMed1994

[Abdominal manifestations in immunocompromised patients].

Abdominal infections or tumors in the immunocompromised host are both common in AIDS but uncommon in transplant recipients. The role of diagnostic imaging modalities differs in the patients with specific symptoms such as dysphagia, diarrhea, malabsorption and jaundice and in the patients with aspecific clinical findings such as fever, weight loss, superficial lymphadenopathies and abdominal pain. In the former patients, the symptoms suggest a disease of one or more alimentary tracts, in which case radiology is ancillary to clinics and endoscopy plays the leading role to make the diagnosis. However, X-ray barium studies yield valuable information on different types of infections--e.g., Candida, Cytomegalovirus, mycobacterium avium intracellulare and Cryptococcus infections--in Kaposi's sarcoma and in gastrointestinal lymphoma. In these cases CT findings may suggest the diagnosis. In the patients with aspecific findings, US, as an easy immediate examination, and CT, as a panoramic means, can demonstrate deep lymphadenopathies and focal parenchymal lesions which are sometimes suspected to be abscesses or tumors. Moreover, both methods can provide indications and guide to percutaneous needle biopsies. Especially CT findings can distinguish mycobacterial infections from neoplastic lesions on the basis of the involved anatomical sites and of densitometric features. US and CT are useful means to monitor HIV+ subjects, to manage AIDS patients and to follow-up transplant recipients.

Acquired Immunodeficiency Syndrome↗

PubMed1994

Biphasic diurnal periodicity in bleeding from peptic ulcer.

OBJECTIVE: To evaluate if there was periodicity in the manifestations of gastrointestinal bleeding (hematemesis and melena). METHOD: This is a multicenter prospective study carried out in the Endoscopy Units of eight hospitals. At the time of the emergency endoscopy, the following data were collected: age, sex, endoscopic diagnosis, solar hour of the first hematemesis (vomiting of bright red or tarry black material) and of the first melena (black or bloody soft stools), and any drugs taken during the week before the bleeding episode, regardless of the dose. RESULTS: 806 patients were studied. Bleeding was from peptic ulcer in 405 patients (50%), from esophageal varices in 197 (24%), and from other sources in the remainder. Analysis using single cosinor statistics showed a nonrandom distribution in bleeding from peptic ulcer, whether presenting first with hematemesis (p = 0.02) or melena (p = 0.03). There were two peaks at 6:45 AM and 6:45 PM for hematemesis and at 7:25 AM and 7:25 PM for melena, representing a biphasic diurnal (ultradian) rhythm. CONCLUSIONS: This study shows that bleeding due to peptic ulcer has a biphasic diurnal periodicity. This has potential importance for the pathogenesis of bleeding, for the management of gastrointestinal hemorrhage and the administration of drugs known to cause peptic ulcer bleeding.

Adolescent↗

PubMed1993

Influence of transdermal scopolamine on cardiac sympathovagal interaction after acute myocardial infarction.

In 41 survivors of acute myocardial infarction (AMI) a prospective study was performed in 2 sequential phases. In phase 1, the role of baroreflex sensitivity and heart rate variability as predictors of inducible and spontaneous sustained ventricular tachyarrhythmias was evaluated. In phase 2, the effects of transdermal scopolamine on baroreflex sensitivity, spectral and nonspectral measures of heart rate variability were investigated. At a mean follow-up of 10 +/- 3 months after AMI, 5 of 41 patients (12%) developed a late arrhythmic event. Of these, all (100%) had inducibility of sustained monomorphic ventricular tachycardia at programmed stimulation compared with 3 of 36 patients (8%) without events (p < 0.0001). At multivariate analysis, baroreflex sensitivity had the strongest relation to both inducibility of sustained monomorphic ventricular tachycardia (p < 0.0001) and occurrence of arrhythmic events (p < 0.0001). Of 41 patients, 28 (68%) consented to undergo phase 2 of the investigation. Baroreflex sensitivity significantly (p < 0.00001) increased after transdermal scopolamine as well as heart rate variability indexes. Of these, the mean of SDs of normal RR intervals for 5-minute segments (p < 0.0001) and the total power (p < 0.0001) had the most significant improvement after scopolamine. The present investigation confirms that assessment of autonomic function is an essential part of arrhythmic risk evaluation after AMI. Transdermal scopolamine, administered to survivors of a recent AMI, reverses the autonomic indexes that independently predict arrhythmic event occurrence. On the basis of these data, transdermal scopolamine could be a potential useful tool in the prophylaxis of life-threatening ventricular arrhythmias after AMI.

Administration, Cutaneous↗

PubMed1993

[Large retroperitoneal hemangiopericytoma. Presentation of a clinical case].

Hemangiopericytoma is a rare and solitary solid tumor originating from pericytes, which are contractile pericapillary cells, first identified and described by Zimmermann in 1923. This neoplasm occurs most commonly in the lower extremities and retroperitoneum. The Authors describe the case of a patient affected with a giant retroperitoneal hemangiopericytoma. Echographic and computed tomographic scans have been fundamental in defining location and size of the neoplasm as well as its relations to the surrounding structures. However a definitive diagnosis was possible only by histologic examination, supported by the proper immunohistochemical stains. The Authors emphasize the difficulty to reliably predict the biological behaviour of these tumors and therefore the necessity of a follow-up of the patients for at least five years, even in the case of a histologically "benign" hemangiopericytoma.

Aged↗

PubMed1993

Chromosomes 8, 12, and 17 copy number in Astler-Coller stage C colon cancer in relation to proliferative activity and DNA ploidy.

Fluorescence in situ hybridization using centromere-specific DNA probes to chromosomes 8, 12, and 17 was applied to 23 archival paraffin-embedded stage C colonic cancer specimens. Chromosome copy number was related to flow cytometric determinations of S-phase fraction and DNA ploidy. Three to eight copies of chromosomes 8, 12, and 17 were observed at mean frequencies of 28.7%, 37.8%, and 20.9%, respectively. The mean frequency of multiple copies of chromosome 12 was significantly greater than that for chromosome 17 (P < 0.0025). The mean frequency of single copies of chromosome 17 was significantly greater than that for chromosomes 8 and 12 (P < 0.0025 and P < 0.0005, respectively). Regarding the fourth quartile of cases, defined on the basis of the frequency of multiple chromosome copies, the proportion demonstrating moderate to high proliferative activity greatly exceeded the proportion displaying low proliferative activity. The same cases (most chromosomally aberrant) also generally demonstrated DNA aneuploidy. The results indicate a substantial degree of karyotypic instability in advanced colon cancer, particularly in cases with high proliferative activity and DNA aneuploidy.

Adenocarcinoma↗

PubMed1993

Different interdigestive antroduodenal motility patterns in chronic antral gastritis with and without Helicobacter pylori infection.

Fasting antroduodenal motor activity was studied in 15 dyspeptic patients with chronic superficial antral gastritis and Helicobacter pylori infection (group A), 10 dyspeptic patients with chronic superficial antral gastritis without Helicobacter pylori infection (group B), and eight healthy control subjects (group C) by manometric recording of phases of the interdigestive migrating motor complex (MMC) prolonged over 240 min. A significantly lower incidence of activity fronts (phase III of MMC) starting from the antrum was observed in patients with gastritis and Helicobacter pylori infection vs patients without bacterial colonization (P = 0.013) and in these latter vs control subjects (P = 0.013). Likewise, the overall number of activity fronts was smaller in patients with gastritis than in healthy subjects (P = 0.034). Symptomatic evaluation was performed in the two groups of dyspeptic patients, without detecting any differences in frequency and severity of complaints. Our results show a significant reduction in the occurrence of interdigestive antral phase III of MMC in chronic gastritis associated with Helicobacter pylori infection, suggesting a possible relationship between fasting motility and bacterial colonization.

Adolescent↗

PubMed1993

Small hepatocellular carcinoma: MR follow-up of treatment with percutaneous ethanol injection.

To assess the potential role of magnetic resonance (MR) imaging in the follow-up evaluation of small hepatocellular carcinoma (HCC) treated with percutaneous ethanol injection (PEI), 31 patients with a single HCC lesion less than 3.0 cm in diameter underwent MR imaging at 0.5 T before and after treatment. Posttreatment follow-up included contrast material-enhanced computed tomography (CT) and fine-needle biopsy in all cases. The most important characteristic of the treated HCC lesions was hypointensity on T2-weighted MR images in cases (27 of 31) in which complete tumor necrosis was achieved with PEI. This feature corresponded to a nonenhanced, low-attenuation area on follow-up contrast-enhanced CT scans. Four HCCs were positive for malignant cells at 6-month fine-needle biopsy; in these lesions, residual tumor tissue was of high signal intensity on T2-weighted MR images and of high attenuation on contrast-enhanced CT scans. In each case, incomplete tumor necrosis was confirmed at pathologic examination of the surgical specimen.

Aged↗

PubMed1993

Carcinoma of the cervix: value of plain and gadolinium-enhanced MR imaging in assessing degree of invasiveness.

The accuracy of nonenhanced spin-echo (SE) T2-weighted and contrast material-enhanced SE T1-weighted magnetic resonance (MR) imaging in assessing the degree of local tumor invasion was determined prospectively in 53 consecutive patients with clinically established early-stage carcinoma of the cervix. With a 0.5-T superconducting unit, pulse sequences of 2,000/90 (repetition time msec/echo time msec) for T2-weighted images and 500/20 for T1-weighted images were used. In all cases, findings of the two MR imaging techniques were compared with results of histologic examination of surgical specimens. Tumor infiltration into the surrounding structures was classified as partial stromal, complete stromal, or parametrial. Tumor-cervical stroma and tumor-parametrium contrast-to-noise ratios (C/Ns) were higher (P < .05) at nonenhanced T2-weighted than at enhanced T1-weighted than at enhanced T1-weighted imaging. In determining the depth of invasion, the overall accuracy was 85% for nonenhanced T2-weighted and 57% (P < .05) for enhanced T1-weighted imaging. With conventional SE sequences, nonenhanced T2-weighted MR imaging is superior to contrast-enhanced T1-weighted MR imaging in determining the degree of invasiveness in clinical early-stage cervical tumors.

Adenocarcinoma↗

PubMed1993

Central and peripheral haemodynamic determinants of effort tolerance in patients with heart failure.

We studied central and peripheral hemodynamics and exercise tolerance in 24 patients with left ventricular dysfunction. All were in NYHA class II or III, and echocardiographic left ventricular ejection fraction was < 35% without pharmacologic influences. Patients underwent to treadmill test (Naughton protocol), cardiopulmonary upright bicycle test, and supine bicycle test with haemodynamic measurements. All tests were exhaustive. Average exercise time was 9 +/- 3.4 min, (range 3-20). Average ejection fraction (.28 +/- 0.65) dis not correlate with working capacity (r = .32), nor did left ventricular filling pressure (pulmonary capillary wedge pressure) at rest and at peak exercise (r = .29 and r = .02). Stroke volume and stroke volume index were on average depressed, with no variations during work; cardiac output and cardiac index were also depressed, with a significant increase at peak exercise (both p < .001). Systemic and pulmonary resistances were increased, but systemic resistances tended to decrease during effort (p < .001), while pulmonary resistances did not (p = NS). We subdivided patients according to systemic vascular resistances lower or higher than 1500 dynes.cm.sec-5 at rest; this identifies two different working capacities (low systemic vascular resistances 11.7 +/- 4.4 min, high systemic vascular resistances 6.9 +/- 3.2 min, p < .05). Patients were then divided in two groups: group I (rest stroke volume > 60 ml) and group II (rest stroke volume < 60 ml). Group I worked 11 +/- 5 min, group II 8.5 +/- 3 min (p < .05). We performed a linear regression analysis between cardiac output and systemic vascular resistances at rest and during exercise in the two groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1993

[Role of gadolinium (Gd-DTPA) in the staging of renal carcinoma using magnetic resonance. Comparative evaluation with computerized tomography and magnetic resonance without contrast media].

The correct staging of renal neoplasms is critical for both prognosis and subsequent treatment planning. This study was aimed at evaluating the accuracy of contrast-enhanced CT, of plain MR and of contrast-enhanced MR in the staging of renal cell carcinomas (RCC). Forty-four consecutive patients with renal masses were evaluated. All of them underwent plain and enhanced CT and 0.5 T plain and Gadolinium-enhanced MR. T1, T2 and Gd-DTPA T1-weighted MR sequences were acquired (500/20; 2000/100). The diagnostic studies were prospectively and separately interpreted by three radiologists. Imaging findings were then correlated with pathologic findings in all cases. The Robson Staging System was used for pathologic classification. The anatomical staging was correctly performed by CT and MR in 36/44 patients (82%) and by Gd-MR in 39/44 (89%). Seven stage-I and 1 stage-IIIC patients were overstaged by enhanced CT and by plain MR (3 patients to stage II and 5 to stage IV A); 5 stage-I patients were over-staged by Gd-MR (4 patients to stage II and 1 to stage IV A). In four cases, in which CT and MR misdiagnosed stage IV A, Gd-MR correctly identified the lack of adjacent organ infiltration. Perinephric spread, venous invasion, metastatic lymphadenopathy and distant metastases were correctly evaluated by the three imaging modalities. Our results suggest that Gd-DTPA could be useful in identifying direct tumor spread to adjacent organs, because of the different enhancement between the cancer and the other tissues.

Adult↗

PubMed1992

Influence of thrombolysis on signal-averaged electrocardiogram and late arrhythmic events after acute myocardial infarction.

The influence of intravenous thrombolysis on both prevalence of ventricular late potentials and incidence of late arrhythmic events was evaluated in 174 consecutive patients surviving a first acute myocardial infarction; 106 patients (61%) received thrombolysis (group A) and 68 (34%) had conventional therapy (group B). In group A, 18 patients (17%) had late potentials compared with 23 (34%) in group B (p less than 0.05); mean left ventricular ejection fraction was not different (0.50 +/- 0.09 vs 0.50 +/- 0.10; p = not significant [NS]). Of 63 patients who underwent coronary arteriography because of postinfarction ischemia, 28 (44%) had a closed infarct-related artery; of these, 11 (39%) had late potentials compared with 3 of 35 (9%) with a patent artery (p less than 0.01). Mean left ventricular ejection fraction was not significantly different between the 2 groups (0.49 +/- 0.09 vs 0.53 +/- 0.09; p = NS). At a mean follow-up of 14 +/- 8 months, 8 of 161 patients (5%) had a late arrhythmic event; 6 of 8 (75%) with and 28 of 153 (18%) without events had late potentials (p less than 0.001). In group A, 4 of 99 patients (4%) had events compared with 4 of 62 (6%) in group B (p = NS, relative risk 1.6). Of 24 patients with anterior wall AMI and left ventricular dyskinesia, 6 events occurred. In this group of patients, a higher rate of events was observed (25%); 3 of 16 (19%) treated with thrombolysis had an event compared with 3 of 8 (37%) treated conventionally (p = NS, relative risk 2.6).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1992

Circadian variation of spectral indices of heart rate variability after myocardial infarction.

The circadian variations of spectral indices of heart rate variability were analyzed in 20 patients 4 weeks after a first and uncomplicated myocardial infarction (MI) and in 20 control subjects. R-R interval and variance showed a characteristic day-night pattern with a significant reduction of the latter parameter in patients after MI (10,967 +/- 1109 msec2 vs 16,860 +/- 2132 msec2). Control subjects were characterized by a predominance of low-frequency (approximately 0.1 Hz) component during the day and of high-frequency (approximately 0.25 Hz) component during the night, which reflected the expected 24-hour pattern of variation of sympatho-vagal balance. A 24-hour elevation (64 +/- 3 normalized units [nu] vs 56 +/- 2 nu; p less than 0.05) of the low-frequency component and a smaller (23 +/- 2 nu vs 32 +/- 2 nu; p less than 0.05) high-frequency component during the night differentiated patients after MI from subjects. The difference between the two groups was even more evident when the 24-hour sympatho-vagal balance was assessed with the low frequency/high frequency ratio. Thus spectral analysis of heart rate variability indicates that in patients after MI there is an alteration of neural control mechanisms as indicated by the presence of signs of sympathetic activation and by the attenuation of the nocturnal increase in vagal tone.

Aged↗

PubMed1992

Functional evaluation 10 days and 3 weeks after acute myocardial infarction: comparative significance and prognostic value.

Early functional evaluation after non-complicated acute myocardial infarction (AMI) is widely recommended because of its prognostic value in the short term. In fact it seems to have a prognostic value within 15-20 days of the AMI, but in this period the patient is particularly controlled and is often still hospitalized. To evaluate the real significance of an early functional evaluation within 10 days of the AMI (mean 8.6 days +/- 1.2) as compared to an identical functional evaluation performed at 3 weeks after AMI (mean 20.16 days +/- 5.38) 25 patients with uncomplicated myocardial infarction were studied. Significant statistical differences were found between the first (ET1) and second (ET2) functional evaluations: they concern the maximal heart rate reached (P less than 0.001), the maximal pressure-rate product (P less than 0.05), the percentage increment of heart rate (P less than 0.01) and the total work performed (P less than 0.001). Agreement between ET1 and ET2 was found in 19 cases; 12 patients showed markers of ischaemia both at ET1 and ET2, while seven were free from ischaemia at both times. In six cases a disagreement between ET1 and ET2 was found: in particular, three cases had ischaemic ET1 and nonischaemic ET2; the reverse was seen in the other three. During follow-up (mean 215.4 days +/- 85.5), the total number of new events (reinfarctions, angina or surgery) among the 25 patients was eight; none occurred within the first 30 days after the AMI.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1992

Myometrial invasion by endometrial carcinoma: assessment with plain and gadolinium-enhanced MR imaging.

A prospective study was designed to determine the sensitivity and specificity of nonenhanced T2-weighted and contrast material-enhanced T1-weighted magnetic resonance (MR) imaging in assessing the depth of myometrial invasion in patients with proved endometrial cancer. In 56 consecutive patients with clinically determined early-stage disease, findings of the two MR imaging techniques were compared with results of histologic examination of surgical specimens. Myometrial invasion was classified as absent (stage IA), superficial (stage IB), or deep (stage IC). In the assessment of each tumor stage, the sensitivity and specificity of contrast-enhanced T1-weighted MR imaging were higher than those of non-enhanced T2-weighted MR imaging. In determining the degree of myometrial tumor invasion, the overall sensitivity of enhanced T1-weighted MR imaging was 87.5%, whereas that of nonenhanced T2-weighted MR imaging was 71.4% (P less than .05). The use of contrast material may improve the ability to assess, with MR imaging, the depth of myometrial invasion by endometrial cancer.

Adult↗

PubMed1992

Regional flow responses to exercise.

Both neural and humoral systems participate in the control of blood flow to various organs. Exercise places the greatest demands on the circulation. At rest, in humans, skeletal muscle receives somewhere between 15% and 20% of cardiac output, while during maximal exercise, this percentage reaches a value of 80% to 90%. The active human muscles have a high-flow capacity that exceeds the capacity of the heart to pump blood. Measurements in single human muscle have indicated that blood flow may be inhomogenous, that is, probably depending on variations of the vasomotor tone of the muscle mediated by humoral and neural factors. Exercise raises cardiac output and coronary blood flow, which rise linearly with increases in heart rate. In normal young men, coronary blood flow averages 280 ml/min/100 g of the left ventricle and reaches as high as 390 ml/min during moderately severe exercise, requiring about 85% of maximal heart rate. In nonexercising organs, the blood flow decreases at about 20% to 40% of the resting values, being the net result of competing vasoconstrictor and vasodilator drives.

Animals↗

PubMed1992

[The electrocardiographic anomalies and 2D-echocardiographic findings during the recovery phase of the stress test in the postinfarct patient].

BACKGROUND: The appearance or the increase of repolarization abnormalities in the EKG during post exercise (ET) recovery phase (R) is considered a marker of ischemia. METHODS: In order to evaluate the real meaning of these changes we compared the EKG data with eventual modifications of left ventricular kinesis analyzed by 2D-ECHO. 10 male patients with previous myocardial infarction, mean age 50 +/- 4.8 y, underwent exercise testing on a treadmill (Bruce's protocol) and continuous 2D-ECHO observation from the end of exercise along the whole R. Patients were divided in two groups: Group A (6 patients) and Group B (4 patients), all free of symptoms. RESULTS: Group A showed ischemic EKG markers during exercise which increased during R; Group B showed ischemic EKG markers only during R. The 2D-ECHO showed in Group A an impairment of left ventricular kinesis at peak exercise without increase or extension during R (WMSI at rest 1.32; peak ET 1.60; R 1.60); in Group B the kinetic alterations appeared only in R (WMSI at rest 1.33, peak ET 1.42; R 1.80), strictly related to EKG markers. CONCLUSIONS: The data suggest : 1) that the increase of EKG abnormalities already present during exercise do not seem to imply more severe ischemia; 2) that EKG changes appearing during R are markers of ischemia which occur in the R.

Echocardiography↗

PubMed1992

Transfection of E. coli with lambda DNA by electroporation.

In the ambit of the B. subtilis genoma sequencing and mapping project, we have set up an electroporation method to transfect E. coli cells with lambda DNA. This methodology presents features that make it preferable to traditional in vitro packaging for some purposes. Here we will illustrate the experimental procedure and the possible applications.

Bacteriophage lambda↗