The expression of nitrite reductase has been tested in a wild-type strain of Pseudomonas aeruginosa (Pao1) as a function of nitrate concentration under anaerobic and aerobic conditions. Very low ...levels of basal expression are shown under non-denitrifying conditions (i.e. absence of nitrate, in both aerobic and anaerobic conditions); anaerobiosis is not required for high levels of enzyme production in the presence of nitrate. A Pseudomonas aeruginosa strain, mutated in the nitrite reductase gene, has been obtained by gene replacement. This mutant, the first of this species described up to now, is unable to grow under anaerobic conditions in the presence of nitrate. The anaerobic growth can be restored by complementation with the wild-type gene.
According to studies done before 1980, the multiple sclerosis (MS) prevalence rate in Italy ranged from 7.2 to 27.1 cases per 100,000 inhabitants. More recent work has consistently put the MS ...prevalence rate to over 30 cases per 100,000 inhabitants. If these recent data are confirmed in the future, Italy can no longer be regarded as a country at low risk for MS, but must be included among the medium-high risk countries of continental Europe. We report the results of a prevalence and incidence survey conducted in Valle d'Aosta, a region whose special features make it an excellent epidemiological model. The mean annual incidence was 2.1 and on December 31, 1985, the prevalence was 39 cases per 100,000 inhabitants. These results confirm that the incidence and prevalence rate of MS in Valle d'Aosta is close to that of areas at high-risk for MS.
A prevalence survey on Parkinson's disease (PD) was performed in the Republic of San Marino, which is the smallest independent state in the world, and is located near the Adriatic coast, within ...Italy. On April 30, 1986, it had a population of 22,322. We found 34 cases of PD (17 men, 17 women). Crude prevalence ratio per 100,000 population was 152 (154 for men, 150 for women) with an age-adjusted ratio of 185 (both sexes). This study shows that the prevalence of PD in the Mediterranean area of South Europe is similar to that in North Europe and the United States.
Although liver transplantation offers definitive treatment for portal hypertension with end-stage liver failure, surgical portosystemic shunts avoid the risks of transplantation and immunosuppressive ...therapy, and transjugular intrahepatic portosystemic shunt (TIPS) creates a portosystemic shunt with minimal operative risk. The appropriate applications of these modalities are discussed.
All adults undergoing primary liver transplantation alone (PLT, n = 265), PLT after TIPS (n = 34), PLT after surgical shunts (n = 12), surgical shunt alone (n = 13), TIPS alone (n = 35), or surgical shunt after PLT (n = 5) served as the basis of this study.
In contrast to surgical shunts before PLT, TIPS before PLT increased the 1-year graft survival. Surgical shunts alone were done in 18 patients with normal or near normal liver function with 100% survival. TIPS alone offered effective symptomatic relief to most patients, all of whom were judged not to be surgical candidates.
TIPS, surgical shunts, and liver transplantation each have a logical role in management of portal hypertension. Surgical candidates with Child's B or C liver failure should be treated with liver transplantation, and TIPS offers effective treatment for nonsurgical candidates. Surgical shunts can be performed with excellent results in patients with Child's A liver disease. Portal vein occlusion with normal liver function can be successfully treated with surgical shunts.
A series of cases of epilepsy with associated bilateral occipital calcifications (EBOC) without signs of phakomatosis and without any disorders known to produce cerebral calcifications have been ...reported. It is unclear whether EBOC is an incomplete variant of Sturge-Weber disease (SWD) or if it is a different, as yet undefined encephalopathy. We describe four new cases of EBOC that are different clinically by age of onset, type, course, severity of epilepsy, and associated cognitive deficits but that are linked by similar neuroradiologic findings. Similar to cases described in the literature, there is convincing evidence in favor of the hypothesis that these cases belong to an encephalopathy different from SWD and frequently associated with celiac disease.
Information overload is a significant problem for the modern radiologist. This prospective study compares the instructional effectiveness of a multimedia textbook (HyperLung) with a lecture. ...HyperLung is a radiologic multimedia textbook about imaging diffuse lung disease created using a multimedia authoring tool, the Annotator (the University of Iowa Second Look Computing, Iowa City, IA), on the Apple Macintosh computer (Apple Computer, Cupertino, CA).
Forty-nine staff physicians and residents in the Department of Radiology were randomized to receive instruction either by HyperLung or by a lecture. The instructional content was the same in both groups, and both groups were tested before and after instruction. The actual time spent in each instructional situation was recorded.
The instructional effectiveness of the multimedia textbook and lecture was equal. The instructional efficiency of HyperLung was only 60% of the lecture. Users of the multimedia textbook found it enjoyable and straightforward to use.
Multimedia textbooks have a promising future in radiology education.
The baseline option for the very forward calorimetry in the CMS experiment is an iron/gas calorimeter based on parallel plate chambers. A small prototype module of such a calorimeter, has been tested ...using electrons of 5 to 100 GeV/
c momentum with various high voltages and two gases: CO
2 (100%) and
CF
4
CO
2
(
80
20
), at atmospheric pressure. The collected charge has been measured as a function of the high voltage and of the electron energy. The energy resolution has also been measured. Comparisons have been made with Monte-Carlo predictions. Agreement between data and simulation allows to make an estimation of the expected performance of a full size calorimeter.
To assess interobserver variability in estimation of brain atrophy based on CT, four neuroradiologists examined CT brain images of 150 consecutive patients without focal lesions. An independent ...neuroradiologist made the following quantitative measurements: frontal horn index, subarachnoid space area and the ratio between subarachnoid space area and inner skull space area. Level of agreement was fair for the presence (k = 0.24), slight for the degree (mild, moderate, severe) (k = 0.24) and moderate for the type (cortical, subcortical, mixed) of atrophy (k = 0.59). There was a highly significant correlation between the number of observers agreeing and quantitative measurements. We concluded that neuroradiologists' subjective estimation of brain atrophy alone is not reliable. Quantitative measurements would be needed in cases where the presence of brain atrophy might determine clinical decisions.
Calcium channel blockers have immunomodulating effects in vitro and may be effective in preventing cyclosporine nephrotoxicity. We studied the effect of verapamil following renal transplantation on ...the incidence of rejection and cyclosporine nephrotoxicity in a double-blind, placebo-controlled trial. Patients were randomly assigned to placebo (n = 28) or verapamil (n = 32) at doses of 80 mg twice a day. There was no difference in the incidence of rejection or cyclosporine toxicity in the two study arms. Recipients randomized to verapamil had lower mean cyclosporine doses at all intervals during a 1-year follow-up. Although cyclosporine doses were lower in the placebo group, the mean cyclosporine levels were equivalent in the two groups. Recipients in the verapamil-treated group had a higher mean serum creatinine at the end of the study--1.7 mg/dL versus 1.4 mg/dL in the placebo group. Actual 1-year graft survival was 89% for the placebo recipients versus 91% in the verapamil-treatment group. When compared with placebo, the concomitant use of low-dose verapamil results in lower cyclosporine doses but equivalent cyclosporine blood levels. Reduction in the incidence of rejection or cyclosporine nephrotoxicity were not observed.
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