Detection of coronary artery stenoses using breath-hold magnetic resonance coronary angiography. Comparison with conventional x-ray angiography

PURPOSE

To detect coronary artery stenoses, we compare breath-hold magnetic resonance coronary angiography (MRCA) to conventional coronary angiography (CA).

MATERIALS AND METHODS

Sixty-five patients with suspected coronary artery disease underwent MRCA and CA within one week. MRCA examination was performed by using the two-dimensional (2D) breath-hold technique with a fast spoil gradient-echo sequence/spiral. Each imaging sequence was obtained within one breath-hold in expiration (14 seconds of apnoea). The assessment of coronary artery stenoses on magnetic resonance (MR) angiograms was independently performed by two blinded readers and compared to conventional CA images.

RESULTS

Three hundred and ninety segments were evaluated by the two imaging techniques. MRCA correctly detected 76 of 88 (86%) stenoses, and recognized 242 of 302 (80%) not affected segments. The Pearson correlation coefficient between MRCA and CA in assessing coronary narrowings was very high: r = 0.85. Despite this the mean difference was 4.5 with a standard error of estimate of 0.21, indicating that MRCA slightly overestimates the degree of stenoses.

CONCLUSIONS

Our study showed that 2D breath-hold MRCA is an accurate technique in displaying and quantifying the most significant stenoses in the proximal and middle segments of the coronary arteries.

Automated cardiac MR image segmentation: theory and measurement evaluation

We present a new approach to magnetic resonance image segmentation with a Gradient-Vector-Flow-based snake applied to selective smoothing filtered images. The system also allows automated image segmentation in the presence of grey scale inhomogeneity, as in cardiac Magnetic Resonance imaging. Removal of such inhomogeneities is a difficult task, but we proved that using non-linear anisotropic diffusion filtering, myocardium edges are selectively preserved. The approach allowed medical data to be automatically segmented in order to track not only endocardium, which is usually a less difficult task, but also epicardium in anatomic and perfusion studies with Magnetic Resonance. The method developed proceeds in three distinct phases: (a) an anisotropic diffusion filtering tool is used to reduce grey scale inhomogeneity and to selectively preserve edges; (b) a Gradient-Vector-Flow-based snake is applied on filtered images to allow capturing a snake from a long range and to move into concave boundary regions; and (c) an automatic procedure based on a snake is used to fit both endocardium and epicardium borders in a multiphase, multislice examination. A good agreement (P<0.001) between manual and automatic data analysis, based on the mean difference+/-SD, was assessed in a pool of 907 cardiac function and perfusion images.

Sex steroid hormones act as growth factors

We observed that sex steroid hormones, like growth factors, stimulate the Src/Ras/erk pathway of cell lines derived from human mammary or prostate cancers. In addition, hormone-dependent pathway activation can be induced in Cos cells, upon transfection of classic steroid receptors. Cross-talks between sex steroid receptors regulate their association with Src and consequent pathway activation. Oestradiol treatment of MCF-7 cells triggers simultaneous association of ER with Src and p85, the regulatory subunit of phosphatidylinositol-3-kinase (PI3-kinase) and activation of Src- and PI3-K-dependent pathways. Activation of the latter pathway triggers cyclin D1 transcription, that is unaffected by Mek-1 activation. This suggests that simultaneous activation of different signalling effectors is required to target different cell cycle components. Thus, a novel reciprocal cross-talk between the two pathways appears to be mediated by the ER. In all tested cells, activation of the signalling pathways has a proliferative role. Transcriptionally inactive ER expressed in NIH 3T3 cells responds to hormone causing Src/Ras/Erk pathway activation and DNA synthesis. This suggests that in these cells genomic activity is required for later events of cell growth.

Numerical construction of "optimal" nonoscillating amplitude and phase functions

A numerical recipe for the construction of nonoscillating amplitude and phase functions for potentials with a single minimum is given. We give different examples illustrating the recipe, showing the usefulness of the procedure for the construction of basis functions in bound-state scattering processes, such as those described by quantum defect theory. The resulting amplitude and accumulated phase functions are coined as "optimal" nonoscillating (as a function of the space and energy variables) because they are the counterpart for the quantum problem of the classical action for the analog semiclassical problem.

[Laparoscopic surgical treatment in abdominal emergencies: personal experience]

In recent years laparoscopic surgery has reached a crucial role in the surgical approach of both abdominal and thoracic pathologies. A diffused as elective surgery, its utilization has become necessary even in emergency surgery, both as diagnostic approach as curative aim. In this work the purpose of the Authors is to show their own experience in a six years period in the laparoscopic treatment of abdominal emergencies.

PI3-kinase in concert with Src promotes the S-phase entry of oestradiol-stimulated MCF-7 cells

The p85-associated phosphatidylinositol (PI) 3-kinase/Akt pathway mediates the oestradiol-induced S-phase entry and cyclin D1 promoter activity in MCF-7 cells. Experiments with Src, p85alpha and Akt dominant-negative forms indicate that in oestradiol-treated cells these signalling effectors target the cyclin D1 promoter. Oestradiol acutely increases PI3-kinase and Akt activities in MCF-7 cells. In NIH 3T3 cells expressing ERalpha, a dominant-negative p85 suppresses hormone stimulation of Akt. The Src inhibitor, PP1, prevents hormone stimulation of Akt and PI3-kinase activities in MCF-7 cells. In turn, stimulation of Src activity is abolished in ERalpha-expressing NIH 3T3 fibroblasts by co-transfection of the dominant-negative p85alpha and in MCF-7 cells by the PI3-kinase inhibitor, LY294002. These findings indicate a novel reciprocal cross-talk between PI3-kinase and Src. Hormone stimulation of MCF-7 cells rapidly triggers association of ERalpha with Src and p85. In vitro these proteins are assembled in a ternary complex with a stronger association than that of the binary complexes composed by the same partners. The ternary complex probably favours hormone activation of Src- and PI3-kinase-dependent pathways, which converge on cell cycle progression.

[Digestive endoscopy in children]

Also in the pediatric population the digestive endoscopy became, at this point, a very good diagnostic and operative technique largement used. The endoscopy can explore the upper gastrointestinal tract (esophagus, stomach, duodenum and jejunum) and can investigate the colon and the terminal ileum regarding the lower gastrointestinal tract. Principally, the operative endoscopy concerns emostasis of gastrointestinal bleeding, polipectomy, extraction of foreign bodies, and intestinal dilatations. The patients population submitted to this investigation by now is very wide thanks to the modernization of the instruments and at specialization of gastroenterologist pediatricians: range from newborn, to childhood, adolescence and young adults. The gastroenterologist pediatricians specialization associated to a routine use of amnemonic drugs (benzodiazepine) reduced at the minimum the invasivity of endoscopy; this technique can be considered a good safe procedure and free of important physical and psychic side effects for the young patient.

Relationship between function and perfusion early after acute myocardial infarction

To assess the relationship between baseline left ventricle function, functional reserve and resting myocardial perfusion in patients with acute myocardial infarction (AMI). After AMI the presence of dysfunctioning but viable myocardium plays a determinant role in clinical outcome. Regional ventricular function was evaluated by echocardiography both in resting conditions and during dobutamine infusion (10 microg/kg/min). Perfusion was assessed by magnetic resonance imaging in a single slice approach where the first pass of an intravenously injected bolus of gadolinium-based contrast agent was followed through six regions of interest within the myocardium. In each patient a region with normal function was used as reference and the cross-correlation coefficient (CCC), which described the myocardial perfusion relatively to the reference region (CCC = 1 means equivalent perfusion), was obtained for the other five myocardial regions. Twenty-two patients were enrolled into the study. Sixty-one segments had normal function and normal perfusion (CCC = 0.92+/-0.23). The perfusion deficit was more marked in the 29 regions with resting akinesia-dyskinesia than in the 20 hypokinetic regions (CCC = 0.71+/-0.45 vs. 0.84+/-0.23; p < 0.05). Out of the 29 regions with resting akinesia-dyskinesia the 13 segments which showed functional improvement following dobutamine had a higher resting perfusion than the 16 segments which were unresponsive to dobutamine (CCC = 0.83+/-0.32 vs. 0.61+/-0.52, p < 0.05). Similarly, out of the 20 regions with resting hypokinesia the 11 segments having functional reserve showed an higher resting perfusion than the segments which did not (0.96+/-0.21 vs. 0.69+/-0.19; p < 0.05). Early after AMI, the perfusion deficit reflects the severity of the mechanical dysfunction. In regions with baseline dyssynergy resting perfusion is, in general, higher when contractile reserve can be elicited by stress-echo.

Effects of estrogen therapy on arterial resistance and pulsatility in postmenopausal women

The hypothesis of this study was that changes in arterial determinants of afterload due to static muscular contraction can be modified, in postmenopausal women, by estrogen replacement therapy. Two groups of 14 postmenopausal and 15 premenopausal women were enrolled. Hemodynamic changes induced by right handgrip were recorded between days 7 and 10 of the menstrual cycle in premenopausal women. The same recordings were performed in postmenopausal women, before and after receiving transdermal estrogen replacement therapy for 8 days. Handgrip was performed at 50% of maximal voluntary contraction and maintained until exhaustion. Arterial pressure and blood velocity were recorded in the resting hand with photoplethysmographic and Doppler techniques. Indices of arterial elasticity and resistance were calculated. In postmenopausal women, these indices increased during effort only slightly less after therapy than before, if the mean values and statistical significance were considered, but the most evident effect of therapy was a decrease in interindividual differences in the effort induced changes. This means that, after therapy, increases in arterial resistance and elasticity indices were appreciably prevented mainly in those postmenopausal women who, before therapy, showed the greatest increases. Differences due to therapy were negligible in postmenopausal women in whom, before estrogen replacement, increases in elasticity and resistance indices during effort were similar to those obtained in premenopausal women. After therapy, no differences were found in resting conditions in any of the investigated cardiovascular parameters. Estrogen replacement did not appreciably affect changes in some arterial afterload-related indexes during handgrip, if the average values were considered in a group of postmenopausal women, but uneven and unpredictable peaks in individual responses were cut off, with a better predictability of the responses to sustained muscular contractions, as well as of the related risk factors.

Steroid-induced androgen receptor-oestradiol receptor beta-Src complex triggers prostate cancer cell proliferation

Treatment of human prostate carcinoma-derived LNCaP cells with androgen or oestradiol triggers simultaneous association of androgen receptor and oestradiol receptor beta with Src, activates the Src/Raf-1/Erk-2 pathway and stimulates cell proliferation. Surprisingly, either androgen or oestradiol action on each of these steps is inhibited by both anti-androgens and anti-oestrogens. Similar findings for oestradiol receptor alpha were observed in MCF-7 or T47D cells stimulated by either oestradiol or androgens. Microinjection of LNCaP, MCF-7 and T47D cells with SrcK(-) abolishes steroid-stimulated S-phase entry. Data from transfected Cos cells confirm and extend the findings from these cells. Hormone-stimulated Src interaction with the androgen receptor and oestradiol receptor alpha or beta is detected using glutathione S:-transferase fusion constructs. Src SH2 interacts with phosphotyrosine 537 of oestradiol receptor alpha and the Src SH3 domain with a proline-rich stretch of the androgen receptor. The role of this phosphotyrosine is stressed by its requirement for association of oestradiol receptor alpha with Src and consequent activation of Src in intact Cos cells.

Predicting patient outcome from acute renal failure comparing three general severity of illness scoring systems

BACKGROUND

A major problem of studies on acute renal failure (ARF) arises from a lack of prognostic tools able to express the medical complexity of the syndrome adequately and to predict patient outcome accurately. Our study was thus aimed at evaluating the predictive ability of three general prognostic models [version II of the Acute Physiology and Chronic Health Evaluation (APACHE II), version II of the Simplified Acute Physiology Score (SAPS II), and version II of the Mortality Probability Model at 24 hours (MPM24 II)] in a prospective, single-center cohort of patients with ARF in an intermediate nephrology care unit.

METHODS

Four hundred twenty-five patients consecutively admitted for ARF to the Nephrology and Internal Medicine Department over a five-year period were studied (272 males and 153 females, median age 71 years, interquartile range 61 to 78, median APACHE II score 23, interquartile range 18 to 28). Acute tubular necrosis (ATN) accounted for 68.7% (292 out of 425) of patients. Renal replacement therapies (hemodialysis or continuous hemofiltration) were used in 64% (272 out of 425) of ARF patients.

RESULTS

Observed mortality was 39.1% (166 out of 425). The mean predicted mortality was 36.2% with APACHE II (P = 0.571 vs. observed mortality), 39.3% with SAPS II (P = 0.232), and 45.1% with MPM24 II (P < 0.0001). Lemeshow-Hosmer goodness-of-fit C and H statistics were 15.67 (P = 0.047) and 12.05 (P = 0.15) with APACHE II, 32.53 (P = 0.0001), 39.8 (P = 0.0001) with SAPS II, 21.86 (P = 0.005), and 20. 24 (P = 0.009) with MPM24 II, respectively. Areas under the receiver operating characteristic (ROC) curve were 0.75, 0.77, and 0.85, respectively.

CONCLUSIONS

The APACHE II model was a slightly better calibrated predictor of group outcome in ARF patients, as compared with the SAPS II and MPM24 II outcome prediction models. The MPM24 II model showed the best discrimination capacity, in comparison with both APACHE II and SAPS II models, but it constantly and significantly overestimated mean predicted mortality in ARF patients. None of the models provided sufficient confidence for the prediction of outcome in individual patients. A high degree of caution must be exerted in the application of existing general prognostic models for outcome prediction in ARF patients.

Results of a national epidemiological investigation on HCV infection among dialysis patients. (Survey by the Italian Branch of EDTNA/ERCA)

The Italian Branch of EDTNA-ERCA organised a retrospective epidemiological investigation on the spread of HCV infection in dialysis. A questionnaire was sent to 830 Italian dialysis centres to collect information about prevalence and incidence of HCV infection among patients and staff, anti-HCV testing, presumed sources of infection, sanitation procedures and dialysis strategies adopted to prevent or reduce the transmission of HCV infection. Twenty-seven percent of the dialysis centres responded to the questionnaire. The answers confirmed the decline in HCV prevalence and incidence. At variance with official health organisation recommendations, isolation of anti-HCV-positive patients is still used in many centres (25%) despite the fact that it is not advisable in view of the high cost and uncertain benefit. Dedicated machines for anti-HCV-positive patients should be adopted, at least in units with a high prevalence of these cases.

Results of a national epidemiological investigation of HCV infection in dialysis patients

The Italian Branch of EDTNA/ERCA organised a national, epidemiological, retrospective study to collect data and implement preventative measures for the spread of HCV infection in dialysis units. A questionnaire was sent to staff in 830 dialysis centres to collect information relating to 1996. Data are presented on incidence/prevalence of HCV infection, antibodies, viraemia and mortality, and comparison of the management of HCV between centres. At variance with the recommendations of the Official Health Organisations, dedicated machines and separate rooms are used in many centres and this paper concludes with recommendations for units, in particular those units with a low prevalence of anti HCV positive patients.

Assessment of trigeminal small-fiber function: brain and reflex responses evoked by CO2-laser stimulation

Laser pulses selectively excite mechano-thermal nociceptors and evoke brain potentials that may reveal small-fiber dysfunction. We applied CO2-laser pulses to the perioral and supraorbital regions and recorded the scalp laser-evoked potentials (LEPs) and reflex responses in the orbicularis oculi, masticatory, and neck muscles in 30 controls and 10 patients with facial sensory disturbances. Low-intensity pulses readily evoked scalp potentials consisting of a negative component with a latency of 165 ms followed by a positive component at 250 ms. In vertex recordings, the amplitude of LEPs exceeded 30 microV. Although only high-intensity pulses evoked reflex responses, some subjects showed--even to low-intensity pulses--an orbicularis oculi (blink-like) response that markedly contaminated the scalp recording. Scalp LEPs were abnormal in patients with hypalgesia and normal trigeminal reflexes and normal in patients with normal pain sensitivity and abnormal trigeminal reflexes. Possibly because of the high receptor density in this area and the short conduction distance, laser stimulation of the trigeminal territory yields low-threshold and large LEPs, which are useful for detecting dysfunction in peripheral and central pain pathways.

Use of the mean transit time of an intravascular contrast agent as an exchange-insensitive index of myocardial perfusion

A simple two-compartment model was used to study the effects of water exchange on the signal produced by an inversion recovery prepared rapid gradient-echo sequence during the first passage of a low dose of an intravascular contrast agent. Water exchange at intermediate rates of exchange (1-10 Hz) between the vascular and extravascular spaces caused the form of the signal changes during the first pass to be dependent on both the fractional sizes of the vascular and extravascular compartments and on the exchange rate. Unless the effects of exchange are minimized by using a very short inversion time, parameters such as the peak height and area under the curve will be affected by regional and/or pathological variations in the exchange rate and the size of the vascular fraction. The mean transit time (MTT) is, however, less affected by water exchange. Experimental first-pass data produced by intravascular low-dose injections of iron oxide particles were studied in five pigs at 0.5 T. The MTT as derived from the first-pass curves, without deconvolution with the arterial input function, was well correlated with the myocardial blood flow (MBF) as measured using radioactive microspheres (r = 0.70, n = 52, P < 0.01). Other first-pass parameters such as the peak height or area under the curve exhibited either a poorer, or no, correlation with the MBF. The data suggest that the MTT of the first pass of an intravascular contrast agent may be a robust, quantitative method for assessing myocardial blood flow in patients.

Prevalence and clinical outcome associated with preexisting malnutrition in acute renal failure: a prospective cohort study

Malnutrition is a frequent finding in hospitalized patients and is associated with an increased risk of subsequent in-hospital morbidity and mortality. Both prevalence and prognostic relevance of preexisting malnutrition in patients referred to nephrology wards for acute renal failure (ARF) are still unknown. This study tests the hypothesis that malnutrition is frequent in such clinical setting, and is associated with excess in-hospital morbidity and mortality. A prospective cohort of 309 patients admitted to a renal intermediate care unit during a 42-mo period with ARF diagnosis was studied. Patients with malnutrition were identified at admission by the Subjective Global Assessment of nutritional status method (SGA); nutritional status was also evaluated by anthropometric, biochemical, and immunologic parameters. Outcome measures included in-hospital mortality and morbidity, and use of health care resources. In-hospital mortality was 39% (120 of 309); renal replacement therapies (hemodialysis or continuous hemofiltration) were performed in 67% of patients (206 of 309); APACHE II score was 23.1+/-8.2 (range, 10 to 52). Severe malnutrition by SGA was found in 42% of patients with ARF; anthropometric, biochemical, and immunologic nutritional indexes were significantly reduced in this group compared with patients with normal nutritional status. Severely malnourished patients, as compared to patients with normal nutritional status, had significantly increased morbidity for sepsis (odds ratio [OR] 2.88; 95% confidence interval [CI], 1.53 to 5.42, P < 0.001), septic shock (OR 4.05; 95% CI, 1.46 to 11.28, P < 0.01), hemorrhage (OR 2.98; 95% CI, 1.45 to 6.13, P < 0.01), intestinal occlusion (OR 5.57; 95% CI, 1.57 to 19.74, P < 0.01), cardiac dysrhythmia (OR 2.29; 95% CI, 1.36 to 3.85, P < 0.01), cardiogenic shock (OR 4.39; 95% CI, 1.83 to 10.55, P < .001), and acute respiratory failure with mechanical ventilation need (OR 3.35; 95% CI, 3.35 to 8.74, P < 0.05). Hospital length of stay was significantly increased (P < 0.01), and the presence of severe malnutrition was associated with a significant increase of in-hospital mortality (OR 7.21; 95% CI, 4.08 to 12.73, P < 0.001). Preexisting malnutrition was a statistically significant, independent predictor of in-hospital mortality at multivariable logistic regression analysis both with comorbidities (OR 2.02; 95% CI, 1.50 to 2.71, P < 0.001), and with comorbidities and complications (OR 2.12; 95% CI, 1.61 to 2.89, P < 0.001). Malnutrition is highly prevalent among ARF patients and increases the likelihood of in-hospital death, complications, and use of health care resources.

The differential pattern of tissue-specific expression of ruminant pancreatic type ribonucleases may help to understand the evolutionary history of their genes

Molecular evolutionary analyses of mammalian ribonucleases have shown that gene duplication events giving three paralogous genes occurred in ruminant ancestors. The enzymes of the bovine species encoded by these genes, isolated from pancreas, brain and seminal vesicles, present similar enzymological properties but distinct structural features. In other ruminant species, genomic sequences orthologous to the bovine genes of pancreas and brain ribonucleases encode active enzymes. In mammalian species other than ruminant artiodactyls, only one gene encoding ribonuclease of the pancreatic type is generally present. In this work, we describe a differential pattern of transcriptional expression of the pancreas and brain ribonuclease genes in the ox species and report transcription of the human ribonuclease gene in brain as well as in pancreas and in mammary gland. We also report the molecular cloning of the gene encoding the bovine seminal ribonuclease in which the structural organization already described for the two paralogous genes is conserved. The seminal RNAase is exclusively expressed in seminal vesicles of Bos taurus, whereas in other ruminant species, the orthologous sequence is a pseudogene. Previous studies from a number of research groups demonstrated that, unlike other mammalian ribonucleases, the seminal enzyme is a covalent dimer, and its unique quaternary structure correlates with special biological activities. The major determinant of dimer formation, i.e. the presence of two adjacent cysteine residues, is absent in the pseudogenes. We advance the hypothesis that the differentiation of distinct expression patterns could represent an important evolutionary determinant for the genes encoding pancreas and brain ribonucleases in ruminants, whereas the differentiation of a quaternary structure endowed with new biological functions could be the main determinant for the evolutionary success of the seminal gene in the bovine species.

Risk stratification by pharmacological stress echocardiography in a primary care cardiology centre. Experience in 1082 patients

AIM

In this study we sought to determine the safety, feasibility and prognostic value of pharmacological stress echocardiography performed in a primary care cardiology centre, populated by unselected patients evaluated with the aid of limited financial and technological resources.

METHODS AND RESULTS

The study population was 1082 patients undergoing pharmacological stress echocardiography with either dipyridamole (n=714) or dobutamine (n=368) for the evaluation of known or suspected coronary artery disease. The echocardiogram was positive in 284 (26%) patients. Two sustained ventricular tachycardias, reversible by antidote, occurred during stress testing. Limiting ischaemia-independent side effects occurred in 1.5% dipyridamole and in 2.4% dobutamine stress echocardiograms. During follow-up (33+/-18 months), 17 cardiac deaths and 27 non-fatal myocardial infarctions occurred. One hundred and twenty-seven patients underwent coronary revascularization, of whom 105 (37%) had a positive and 22 (3%) a negative stress testing result (P<0.0001). At Cox analysis, allowing for 14 clinical and stress-echo variables. the independent predictors of cardiac death were, in decreasing order, a positive stress testing result (Odds ratio [OR]=6.0), resting wall motion score index (OR=5.7), age greater than 65 years (OR=4.9), previous Q-wave myocardial infarction (OR=3.5), and hypercolesterolaemia (OR=2.7). The 4-year survival rate was 99.2% for patients with a negative and 89.8% for patients with a positive stress testing result (P=0.0000). When cardiac hard events (cardiac death and non-fatal myocardial infarction) were considered as end-points, the following variables were independently associated with prognosis: positive result of stress testing (OR=3.1), hypercolesterolaemia (OR=2.4), and resting wall motion score index (OR=2.7). The 4-year infarction-free survival rate was 97.0% for patients with a negative and 81.4% for patients with a positive stress testing result (P=0.0000).

CONCLUSIONS

Pharmacological stress echocardiography with either dipyridamole or dobutamine was safe and feasible, providing an excellent tool for prognostic assessment of coronary artery disease in a primary care cardiology centre.

Significance of myocardial ischemic electrocardiographic changes during dipyridamole stress echocardiography

The aim of this study was to assess the diagnostic and prognostic value of the presence and characteristics of ischemic electrocardiographic (ECG) changes during dipyridamole stress echocardiography. The ECG response in 178 patients with echocardiographic evidence of myocardial ischemia during dipyridamole stress testing was analyzed. ECG changes occurred in 105 patients (59%). Patients with ECG changes had a higher incidence of echocardiographic signs of ischemia at a low dose than patients with an unchanged electrocardiogram (50% vs 23%; p = 0.0002). Three-vessel and/or left main coronary artery disease (CAD) was found in 41% of patients with and in 21% of patients without ECG changes (p = 0.029). During follow-up (33 +/- 19 months), 30 cardiac events occurred: 10 deaths, 6 infarctions, and 14 unstable anginas. Coronary revascularization was performed in 48 patients with and in 17 patients without ECG changes (p = 0.0022). The univariate predictors of cardiac events were: presence of ischemia in > or =4 ECG leads (p = 0.0004), echocardiographic evidence of ischemia at a low dose (p = 0.0062), ST-segment shift on precordial leads (p = 0.0094), family history of CAD (p = 0.0115), coexistence of > or =3 cardiovascular risk factors (p = 0.0156), ST-segment depression (p = 0.0172), and ECG changes during testing (p = 0.0335). At Cox analysis, occurrence of ischemia at a low dose (odds ratio 3.0; 95% confidence interval 1.3 to 6.8) and the presence of ischemia in > or =4 ECG leads (odds ratio 3.5; 95% confidence interval 1.3 to 9.3) had an independent prognostic importance. In conclusion, the presence and characteristics of ischemic ECG changes are associated with more extensive CAD and worse prognostic outlook than are echocardiographic changes alone during dipyridamole stress echocardiography.

Universal precautions and dedicated machines as cheap and effective measures to control HCV spread

Haemodialysis patients are at great risk for HCV infection, and a strict relationship is clear between anti-HCV positivity and dialysis age or hospital dialysis, irrespective of previous blood transfusions. Notwithstanding that, the precise root of its nosocomial nontransfusional diffusion among haemodialysis patients is not clear yet. As isolation is a very expensive policy, we evaluated whether simpler measures such as the observance of the Universal Precautions (UP), and the use of anti-HCV positive patient dedicated monitors can stop the diffusion of HCV infection in a hospital haemodialysis centre. Since January 1990 to December 1991 (1st phase), the patients shared the monitors irrespective of their serological status for HCV, and training of the dialysis care staff was not performed with regard to the UP. Since January 1991 to June 1996 (2nd phase), according to the UP, strictly personal dialysis-tools were used for all patients, anti-HCV positive patients were assigned to dedicated monitors in defined (not separated) areas of the dialysis rooms and the dialysis care staff was trained to the strict observance of the UP. In the first phase of the follow-up 5 seroconversions occurred; none occurred in the second one. Our study shows that isolation is not required for such patients. We believe that measures such as the application of UP, dedicated machines and continuous training of the care staff, instead of the isolation of positive patients, result in the same efficacy and are cheaper than isolation of positive patients. Therefore they are mandatory for all haemodialysis centres.

Activation of the Src/p21ras/Erk pathway by progesterone receptor via cross-talk with estrogen receptor

The molecular mechanisms by which ovarian hormones stimulate growth of breast tumors are unclear. It has been reported previously that estrogens activate the signal-transducing Src/p21(ras)/Erk pathway in human breast cancer cells via an interaction of estrogen receptor (ER) with c-Src. We now show that progestins stimulate human breast cancer T47D cell proliferation and induce a similar rapid and transient activation of the pathway which, surprisingly, is blocked not only by anti-progestins but also by anti-estrogens. In Cos-7 cells transfected with the B isoform of progesterone receptor (PRB), progestin activation of the MAP kinase pathway depends on co-transfection of ER. A transcriptionally inactive PRB mutant also activates the signaling pathway, demonstrating that this activity is independent of transcriptional effects. PRB does not interact with c-Src but associates via the N-terminal 168 amino acids with ER. This association is required for the signaling pathway activation by progestins. We propose that ER transmits to the Src/p21(ras)/Erk pathway signals received from the agonist-activated PRB. These findings reveal a hitherto unrecognized cross-talk between ovarian hormones which could be crucial for their growth-promoting effects on cancer cells.

Augmentation ileocystoplasty in a case of eosinophilic cystitis

Eosinophilic cystitis (EC) is a rare form of bladder inflammation characterized by massive eosinophilic infiltration of the bladder wall. The most frequent signs and symptoms are pollakiuria, urgency, macroscopic haematuria and hypogastric pain: the involvement of the ureters may cause hydronephrosis and renal failure. Eosinophilia and eosinophiluria are present in 35% and in 50% of the cases respectively. EC may evolve towards sclerosis up to the anatomoclinical picture of small retracted bladder, which requires to be differentiated from tubercular cystitis, interstitial cystitis and cancer. Imaging techniques are not definitely diagnostic. Diagnosis can be reached only by biopsy with the microscopic demonstration of eosinofilic infiltration of the whole bladder wall in the early and acute stages, while fibrosis with poor cellularity predominates in the chronic stages. Etiology is unknown and the hypothesis of an allergic origin is unproved even though remissions or recoveries induced by steroidal therapy have been reported. Surgical therapy of EC, as in our observation, is absolutely required to correct urgency and incontinence and to prevent renal failure when the urinary upper tract has been primarily or secondarily involved.

MRI for the evaluation of regional myocardial perfusion in an experimental animal model

Myocardial perfusion was assessed in nine pigs using ultrafast gradient-echo MRI (.5 T, 15-mT/m gradients) at different levels of myocardial blood flow (range, .005-1.84 ml/min/g), generated either by adenosine infusion or by a mechanical occluder, and measured independently using radiolabeled microspheres. Sixty-four consecutive, ECG-triggered, diastolic, short axis images of the left ventricle were obtained during intravenous bolus injections (n = 30) of .05 mmol/kg of gadopentetate dimeglumine. Relative changes in peak intensity, time to peak intensity, washin slope, correlation coefficient, and cross-correlation coefficient were computed from the time-intensity curves obtained from four regions of interest, namely septal, anterior, lateral, and inferior walls. The values from the inferior wall acted as reference for evaluating relative changes in the other three regions. The cross-correlation coefficient (P < .001, rho = .60) and the peak intensity (P < .001, r = .72) showed the best correlation with myocardial blood flow. The washin slope showed a weak positive trend (P < .05), but the low value of r (r = .28) indicated that the use of this parameter to predict flow was invalid; the correlation coefficient and time to peak intensity were not correlated (P = ns). In conclusion, this study shows that it is possible to evaluate relative myocardial perfusion after the first pass of a an intravenously injected bolus of gadopentetate dimeglumine, using dynamic MRI on a conventional medium field MRI system. The cross-correlation coefficient and the peak intensity resulted in more efficient parameters to evaluate relative inhomogeneity of regional myocardial perfusion.

[Liposarcoma of the spermatic cord. Clinical case]

Sarcomas are neoplasms originating from connective tissues of any anatomical region; the sarcoma of spermatic cord is a rare neoplasm with only little more than two hundred cases described in the literature. Rhabdomyosarcomas in childhood and leiomyosarcomas in adults are the most frequent histological types. Liposarcomas, fibrosarcomas and osteosarcomas are less frequent. The spermatic cord liposarcoma originates from the spermatic cord fatty tissue and therefore it consist of adipose cells, fibroblasts and myxomatosus cells; such neoplasms are usually very well differentiated. Diagnosis is suggested by the appearance of a progressively enlarging mass and by echotomography which shows a solid or liquid mass of the spermatic cord. Therapy consists of surgical intervention (orchifunicolectomy) which also allows a correct histological diagnosis. The case of a 56 year-old male who underwent left orchifunicolectomy for a sarcoma of spermatic cord occasionally discovered during surgical repair of a left groin hernia is reported. Six months after the intervention the patient is in good condition and there is no evidence of relapse.

Prognosis of myasthenia gravis: a retrospective study of 380 patients

The 9139 follow-up records of 438 myasthenia gravis (MG) patients were reviewed. Excluding those patients who were diagnosed 5 or more years after symptom onset (n = 37) and those who experienced only oculomotor symptoms throughout follow-up (n = 21), there were 380 patients. A survival analysis approach was used to assess the influence of prognostic factors on the following endpoints: (a) stable complete remission, (b) complete remission of at least 6 months and (c) pharmacological remission of at least 6 months. Early diagnosis was associated with a better prognosis with respect to all endpoints. Thymectomy also improved the prognosis but only for those patients without thymoma. Later MG onset was associated with a higher tendency to achieve pharmacological remission.

Image postprocessing and contrast agents in clinical MR imaging--an introductory overview

Some fundamentals of image processing, its applications to MR imaging, and inherent problems are discussed. Processing of contrast-enhanced dynamic imaging studies is introduced and some clinical examples explain the applications in research and clinical routine.

An independent software system for the analysis of dynamic MR images

PURPOSE

A computer system for the manual, semi-automatic, and automatic analysis of dynamic MR images was to be developed on UNIX and personal computer platforms. The system was to offer an integrated and standardized way of performing both image processing and analysis that was independent of the MR unit used.

MATERIAL AND METHODS

The system consists of modules that are easily adaptable to special needs. Data from MR units or other diagnostic imaging equipment in techniques such as CT, ultrasonography, or nuclear medicine can be processed through the ACR-NEMA/DICOM standard file formats. A full set of functions is available, among them cine-loop visual analysis, and generation of time-intensity curves. Parameters such as cross-correlation coefficients, area under the curve, peak/maximum intensity, wash-in and wash-out slopes, time to peak, and relative signal intensity/contrast enhancement can be calculated. Other parameters can be extracted by fitting functions like the gamma-variate function. Region-of-interest data and parametric values can easily be exported.

RESULTS AND CONCLUSION

The system has been successfully tested in animal and patient examinations.

Myocardial perfusion by contrast-enhanced echocardiography and dynamic contrast-enhanced MR imaging

The evaluation of myocardial perfusion is of clinical relevance in ischemic heart disease. New noninvasive and nonionizing imaging techniques for the evaluation of myocardial perfusion are progressing. The present status and the future development of echo-contrast and dynamic-contrast MR imaging are discussed for myocardial perfusion studies.

Residual myocardial perfusion in reversibly damaged myocardium by dipyridamole contrast echocardiography

In patients with previous myocardial infarction and left ventricular asynergy, dipyridamole infusion may have the capacity to unmask myocardial viability through transient recovery of contractile function in asynergic segments. The purpose of this study was to assess simultaneous changes in myocardial perfusion and LV function--elicited by dipyridamole infusion--in infarcted, asynergic segments. The echo contrast agent Albunex was injected into the left coronary artery of 19 patients (17 males, age 49-70 years) with previous myocardial infarction and baseline left ventricular asynergy, both before and after dipyridamole infusion (up to 0.56 mg.kg-1, i.v.). Analysis was not possible in three patients due to inadequate image quality and in two due to weak contrast. There were no major adverse events, or changes in vital signs or demonstrated on the electrocardiogram. After dipyridamole, 7/14 patients, showed an improvement in regional function of asynergic segments ('responders'), whereas seven patients did not ('non-responders'). Among non-responders, five had a myocardial perfusion deficit corresponding to 41% of the total left ventricular area before dipyridamole and to 38% after dipyridamole. No baseline perfusion deficits were observed in the remaining two non-responders; one of these, however, developed transient asynergy and perfusion deficit after dipyridamole. Among responders, five showed a normal perfusion pattern, both before and after dipyridamole, while the remaining two showed a perfusion deficit which markedly decreased after dipyridamole (from 32% to 13% of total left ventricular area). Thus, residual contractile reserve of asynergic, infarcted ventricular segments appears to be associated with myocardial perfusion either preserved at baseline or recruitable by a coronary dilator stimulus.

Breathing during sleep in myasthenia gravis

The aim of this study was to assess breathing patterns during sleep in patients with generalized mild myasthenia gravis. Fourteen patients (13 F; 1M, age range 20-40 years) in a stable clinical and functional state underwent a sleep questionnaire, baseline respiratory function tests and standard nocturnal polysomnography. All of the patients had normal daytime blood-gas values, except one who showed mild hypoxemia. No patient complained of disturbed sleep; six patients reported snoring. In five patients nocturnal polysomnography showed the occurrence of short and infrequent central apneas mainly during REM sleep, together with a drop in HbSaO2 levels of more than 5% of the baseline wakefulness value. Our data indicate that, in patients with mild generalized MG in a stable functional state, breathing pattern instability during sleep is infrequent and, when it occurs, is mild and mainly related to REM sleep.

Ergonovine-echo test to assess the significance of chest pain at rest without ECG changes

The aim of this study was to assess the feasibility and diagnostic role of ergonovine maleate infusion under continuous two-dimensional echocardiographic monitoring for the identification of vasospastic myocardial ischaemia in patients with chest pain at rest not associated with diagnostic ECG changes. One hundred and twenty-eight consecutive patients, selected on the basis of absence of ischaemic ECG changes during angina at rest before or during hospitalization, were enrolled in the study. Ergonovine maleate was i.v. administered in scaled doses (from 0.025 to 0.2 mg at 10 min intervals) under echocardiographic, electrocardiographic and systemic blood pressure monitoring. Wall motion asynergies were observed in 33 patients, accompanied by typical chest pain in 24 patients and by ECG changes in 25 (ST elevation in 13 patients, ST depression in seven, T wave changes in five). All patients were able to complete the test. Non life-threatening ventricular arrhythmias were observed in four patients exclusively in association with ischaemia. In seven patients with a positive test, coronary artery spasm was documented at angiography. In 16 patients with a positive test, the vasospastic event was reproduced by a hyperventilation-echo test or a second ergonovine maleate-echo test performed within 3 days of the first examination. In none of the patients with a negative test was documentation of myocardial ischaemia due to a primary reduction in coronary blood flow. Thus, in patients who do not show ECG changes during chest pain at rest, the ergonovine maleate-echo test is feasible and safe; it permits the recognition of ischaemic episodes on the basis of wall motion abnormalities when conventional 12-lead ECG-recorded chest pain is non-diagnostic.

[Early gastric cancer]

The authors perform a retrospective analysis of 46 cases of EGC referred to the Surgical Division of Carrara Civic Hospital during the period 1980-1990 who subsequently underwent surgery. Data relating to age, symptomatology and endoscopic examinations were analysed in order to evaluate the real diagnostic penetration of the method in association with tumour biopsy, site, macroscopic aspect, possible lymph node involvement and the histology of lesions. The most frequent form of surgery in this series was subtotal gastrectomy and the 5- and 10-year survival rates, calculated using an actuarial method, were compared with data reported in the literature. The authors conclude by emphasising the need to improve the frequency of diagnosis of gastric cancer at an "early" stage and affirm that gastric resection associated with lymphoadenectomy of 1st and 2nd level lymph nodes is a sufficiently radical operation and less punitive for the patient compared to total gastrectomy given that the 5- and 10-year survival rates are comparable.

Relationship between icam-1 serum levels and thymostimulin therapy in patients with liver-cirrhosis associated with hepatocellular-carcinoma

Intercellular adhesion molecule-1 (ICAM-1), is a cell surface molecule involved in many immunological processes. Recently, ICAM-1 has also been detected as a soluble form in sera of patients affected by different pathologies and often associated with severity of the disease. However, all these studies were carried out in patients before drug treatment. Since in vitro experiments and recent evidence in humans has indicated the possibility that some cytokines may be responsible of ICAM-1 release, we have considered the possibility of quantitating ICAM-1 in sera of patients undergoing therapy with drugs influencing cytokine regulation. Thymostimulin, which seems to belong to this category, has been used in a pilot study by some of us in the treatment of patients with liver cirrhosis associated with hepatocellular carcinoma. By using an enzymatic sandwich assay, we found significantly high circulating ICAM-1 mean values in patients affected by liver cirrhosis alone or associated with hepatocellular carcinoma or non-Hodgkin lymphoma compared to control subjects (p<0.001), Moreover, in patients with hepatocellular carcinoma or liver cirrhosis who were treated with thymostimulin, serial detection of c-ICAM-1 was carried out and patients responsive to the drug showed significantly increased values of c-ICAM-1 (p=0.006), Our study suggests that an evaluation of c-ICAM-1 levels needs to be considered in the context of the therapeutic approach, with particular attention to those drugs which may affect the regulation of the cytokine pathway.