Measurement of liver iron overload: noninvasive calibration of MRI-R2* by magnetic iron detector susceptometer.

An accurate assessment of body iron accumulation is essential for the diagnosis and therapy of iron overload in diseases such as thalassemia or hemochromatosis. Magnetic iron detector susceptometry and MRI are noninvasive techniques capable of detecting iron overload in the liver. Although the transverse relaxation rate measured by MRI can be correlated with the presence of iron, a calibration step is needed to obtain the liver iron concentration. Magnetic iron detector provides an evaluation of the iron overload in the whole liver. In this article, we describe a retrospective observational study comparing magnetic iron detector and MRI examinations performed on the same group of 97 patients with transfusional or congenital iron overload. A biopsy-free linear calibration to convert the average transverse relaxation rate in iron overload (R(2) = 0.72), or in liver iron concentration evaluated in wet tissue (R(2) = 0.68), is presented. This article also compares liver iron concentrations calculated in dry tissue using MRI and the existing biopsy calibration with liver iron concentrations evaluated in wet tissue by magnetic iron detector to obtain an estimate of the wet-to-dry conversion factor of 6.7 ± 0.8 (95% confidence level).

Radioguided occult colonic lesion identification (ROCLI) during open and laparoscopic surgery.

AIMS AND BACKGROUND: Intraoperative localization, during open and laparoscopic surgery, of small, nonpalpable colonic lesions located at peculiar sites or with concurrent inflammatory bowel alterations (diverticulosis, perivisceritis) is often difficult. The aim of our work was to assess the validity of radioguided identification after preoperative labeling. METHODS AND STUDY DESIGN: Patients who were candidates for colon surgery for occult lesions that, because of their size and location, were assumed to be difficult to detect, underwent colonoscopy 1 to 2.5 hours before surgery. A small dose of labeled albumin macroaggregates was injected with a sclerotherapy needle into the subserosa underneath the lesion. Immediately following the injection the lesion was identified with a transcutaneously placed gamma detecting probe. Intraoperative tracer detection was performed either during open surgery or by means of a laparoscopic probe (detection time 3-5 mins). The position of the lesion was marked with a suture or with a clip. Surgery was performed according to the type of lesion to be treated. RESULTS: In our initial clinical experience 15 colon lesions were preoperatively marked in 14 patients and were subsequently detected during surgery (four under laparoscopy) with a gamma detecting probe. This technique allows highly accurate, fast, and inexpensive surgical localization of lesions without irradiation and without complications. CONCLUSION: Our experience shows that preoperative endoscopic marking of nonpalpable colon lesions with 99mTc-labeled albumin macroaggregates followed by intraoperative detection with a gamma probe is a useful clinical method that is highly accurate and without complications.

Estimation of lead intake from crystalware under conditions of consumer use.

The purpose of this study was to estimate the lead intake from crystalware resulting from short-term contacts with beverages, under conditions that are likely to occur to a consumer. The extraction ability of different kinds of beverages was estimated by comparison with 4% acetic acid under conditions of continuous contact for 3 h. It was found that lead release increased in the following order: cola drink > HAc > whisky > white wine. Under conditions of repeated use under different scenarios, lead release showed a steep decrease with increasing number of contacts, for both wine and cola drink. The maximum lead intake resulted from the cola drink, corresponding to an ingestion of 14.5 micrograms Pb for consumption of 350 ml beverage. Assuming a fixed contribution from the diet of 71 micrograms/day, in the six scenarios taken into consideration, total daily lead intake levels ranged from a minimum of about 76 micrograms up to a maximum of 86 micrograms lead. As these values, converted on a weekly basis, would correspond to 35% and 40% PTWI respectively, significant health risks resulting from the ingestion of beverages in contact with crystalware can be excluded. Finally it was found that the use of a dishwater did not affect significantly the release of lead into wine, while release into cola drink was slightly but significantly increased after the third cycle.

Intra- and inter-individual biological variability data bank.

Different results are usually observed when a quantity is measured in different specimens from the same individual obtained over a time span. For an individual, this variation is due to the imprecision of the measurement procedure, that is to say the metrological variability, as well as to the rhythmic and random fluctuations of the quantity value around a virtual homeostatic set point, that is to say the intra-individual biological variability. On the other hand, when studying the intra-individual biological variation of a quantity a mean value, the virtual homeostatic set point, is estimated for each individual participating in the study. The variation among these mean values is due to the inter-individual biological variability.

Prognostic significance of quantitative electroencephalography in Alzheimer patients: preliminary observations.

In 31 Alzheimer outpatients followed up for a mean time of 26.4 months the hypothesis that quantitative electroencephalography (qEEG) could predict the loss of activities of daily living (ADL), the onset of incontinence, and death was tested by the Weibull proportional hazard model of 'lifereg' procedure of the Statistical Analysis System package. A central-posterior temporal region was considered in either side (power-weighted, log transformed relative values). Right delta predicted both the loss of ADL and death, whereas right theta predicted the onset of incontinence. Left values gave borderline significant results toward all end-points, whereas power-weighted mean frequency always gave borderline results. The curves calculated for predicted times may be a valid support for the clinician in attempting prognostic judgments of disease evolution.

Segmentation of multivariate medical images via unsupervised clustering with "adaptive resolution".

The need for quantitative information is becoming increasingly important in the clinical field. In this paper we present an interactive X11 based system, devoted to segmentation of multivariate medical images, including an unsupervised neural network approach to clustering. The following steps are considered in the analysis sequence: feature extraction, reduction of dimensionality, unsupervised data clustering, voxel classification, interactive post-processing refinement. The environment turns out to be extremely interactive, thus making the user able to display and modify data during processing, to set parameters, to choose different methods and different tools for each step, and to define online the whole analysis sequence.

Diagnostic paracentesis. A two-step approach.

Diagnostic paracentesis is usually considered the first test to be performed in the assessment of the ascitic patient and a large number of investigations on ascitic fluid have been proposed. To assess the value of a simplified procedure, serum to ascites albumin gradient and ascitic white blood cell counts were employed as a first step. One hundred and fifty-three paired serum and ascitic fluid samples were analysed and allowed patients to be divided into three groups: 1) serum to ascites albumin gradient > = 11 g/L and white blood cells < 0.5 x 10(9)/L predicted cirrhosis (or liver carcinoma) without peritonitis with 83% efficacy, 96% positive predictive value and 65% negative predictive value; 2) serum to ascites albumin gradient > = 11 g/L and white blood cells > = 0.5 x 10(9)/L predicted cirrhosis (or liver carcinoma) with peritonitis with 86% efficacy, 45% positive predictive value and 99% negative predictive value; 3) serum to ascites albumin gradient < 11 g/L predicted the other diagnoses with 92% efficacy, 77% positive predictive value and 95% negative predictive value. As serum to ascites albumin gradient > = 11 g/L and white blood cells < 0.5 x 10(9)/L predicted cirrhosis (or liver carcinoma) without peritonitis in 96% of the cases and excluded peritonitis in 99% of the cases, further fluid ascitic analyses could be considered as a second step only in patients with serum to ascites albumin gradient < 11 g/L and/or white blood cells > = 0.5 x 10(9)/L. In a group of ascitic patients where the prevailing diagnosis is cirrhosis (or liver carcinoma) without peritonitis, this simplified approach could provide a favourable cost/benefit ratio.

Assessment of regional cerebral blood flow during spinal cord stimulation in humans.

Increased cerebral perfusion has been reported in both animal models and humans undergoing spinal cord stimulation (SCS). However, this was an inconsistent finding and variables able to influence regional cerebral blood flow (rCBF) following SCS are poorly investigated. We report our experience on rCBF measurements by the xenon-133 inhalation technique in 20 patients receiving acute and chronic SCS for different pathologies in basal conditions. Neither acute nor chronic SCS induced significant rCBF changes in the group of patients as a whole. However females, non-atherosclerotic patients and patients with a cervical SCS lead, showed a trend (borderline statistical significance) toward a redistribution of rCBF with increased values in frontoprerolandic and decreased values in postrolandic regions. Although SCS appears to influence intracerebral distribution more than absolute changes in blood flow, the mechanisms underlying such a phenomenon remain unknown. Functional activation of frontal lobes by the ascending reticular pathways through the thalamofrontal projections could be one possible hypothesis which has to be confirmed by further studies.

Regional cerebral blood flow in familial hypercholesterolemia.

BACKGROUND AND PURPOSE: Although epidemiologic investigations are trying to clarify the role of plasma lipid concentrations (primarily cholesterol and its subfractions) as risk factors for both ischemic and hemorrhagic stroke, little information is available regarding the effect of sustained hypercholesterolemia on cerebral perfusion. METHODS: Regional cerebral blood flow (CBF) was measured by the 133Xe inhalation method in 25 heterozygous patients (four untreated) affected with familial hypercholesterolemia. In 15 patients regional CBF was repeated 20 minutes after intravenous administration of acetazolamide (10 mg/kg body wt) to evaluate cerebrovascular reactivity. Correlations among cerebral perfusion data, present or pretreatment plasma lipid concentrations, and certain other clinical features were assessed by ANOVA. RESULTS: Both basal regional CBF and cerebrovascular reactivity were normal in the vast majority of patients compared with age- and sex-matched normal control subjects. CBF was significantly dependent on pretreatment low-density lipoprotein cholesterol (LDL-C) concentration (P = .005) and the presence of symptomatic ischemic heart disease (P = .015). CBF was only slightly dependent on age (P = .05) and was not dependent on either lipoprotein(a) or present LDL-C concentration. CBF did not differ between treated and untreated patients, and the perfusional increase induced by acetazolamide was not related to any other variable. CONCLUSIONS: Cerebral perfusion and cerebrovascular reactivity were maintained within the normal range despite long-lasting, severe hypercholesterolemia, even if a somewhat lower CBF was found in those patients with the highest LDL-C pretreatment levels. These results are in accord with the epidemiologic data that implicate hypercholesterolemia as a minor risk factor, if a risk factor at all, for intracranial atherosclerosis and ischemic stroke.

Regional cerebral blood flow in chronic hypertension. A correlative study.

BACKGROUND AND PURPOSE: Cerebral hypoperfusion has occasionally been reported during essential hypertension. We explored regional cerebral blood flow in a large series of neurologically asymptomatic hypertensive patients to determine relations among cerebral blood flow, concomitant main vascular risk factors, and the most common signs of end-organ damage. METHODS: Regional cerebral blood flow was measured by the 133Xe inhalation method in 101 hypertensive patients without clinically apparent central nervous system involvement, including 39 mild to moderate untreated and 62 mild to severe treated patients. RESULTS: Compared with age- and sex-matched normal control subjects, cerebral blood flow was significantly reduced in untreated hypertensive patients (P < .01) and to a lesser extent in treated patients (P = .047). Both regional and global cerebral blood flow reductions were observed in approximately one third of patients in both groups. Analysis of variance failed to show significant correlations between cerebral blood flow and total cholesterol concentration, mean arterial blood pressure, duration of disease, or the presence of retinopathy or left ventricular hypertrophy. In the treated group, the quality of control of hypertension significantly influenced both global cerebral blood flow (P = .007) and cerebrovascular resistance (P < .0001). CONCLUSIONS: Focal or diffuse cerebral hypoperfusion is present even in neurologically asymptomatic hypertensive patients, especially when untreated; good control of blood pressure may preserve cerebral perfusion and reduce cerebrovascular resistance. Regional cerebral blood flow examination represents a relatively simple and low-cost technique to explore the perfusional condition of the brain, one of the main target organs of hypertensive disease.

[A sulfadiazine-tetroxoprim combination (co-tetroxazine) in the treatment of the acute exacerbation of chronic bronchitis]. / L'associazione sulfadiazina-tetroxoprim (co-tetroxazina) nel trattamento delle riacutizzazioni delle broncopatie croniche.

After considering the bacterial flora which is most common in relapses in patients with bronchitis, 40 patients with chronic bronchitis have been treated with tetroxoprim a recently synthetized benzyl pyrimidine associated with sulfadiazine. One 350 mg tablet was administered every 12 hours for different periods, from 7 to 14 days. This study has shown how tetroxoprim has a wide antibacterial range, how it is well tolerated and extremely powerful in treating relapses of chronic infections in bronchi.

[Transferable antibiotic resistance of Salmonellae isolated at the Novara General Hospital in 1977]. / Antibiotico-resistenza-trasferibile in salmonelle isolate presso l'Ospedale Maggiore di Novara nel 1977.

Of 74 strains of Salmonella isolated by the Laboratory of Microbiology of the Hospital of Novara in 1977 and belonging to 20 different serotypes, transfer of antibiotic-resistance, mostly multiple (Streptomycin, Chloramphenicol, Kanamycin, Tetracycline, Ampicillin) has been detected in 78,5% of 28 antibiotic-resistant strains. As in previous investigations made by the same Laboratory, the highest percentages of transfer of resistance have been observed in some serotypes (S. typhi murium, S. panama), while that was observed only in S. enteritidis isolated in 1977. At last in this period was S. wien able to transmit multiple resistance isolated only once.