Incidence of enteropathogens in patients with human immunodeficiency virus infection

BACKGROUND: To establish the incidence of diarrhea and its evolution over time, the causal microorganisms, recurrence and associated mortality in patients with AIDS or severe immunologic alterations (CD4 lymphocytes lower than 0.5 x 10(9)/l). METHODS: A prospective longitudinal study was carried out from 1984 to 1992. The following patients were included in the study: 1) all those patients with diarrhea in whom a pathogenic microorganism was identified in the stools, and 2) patients with fever and positive blood cultures for enteropathogenic bacteria. The patients belonged to a series of 1,456 patients with infection by HIV. RESULTS: Of the 1,456 controlled patients, 253 (17%) had infection by enteropathogenic microorganisms. The incidence was greater in homosexual patients (26%) than in drug addicts (12%). The most frequent germs were Cryptosporidium, in 104 episodes and Salmonella sp. in 78 episodes (31 as isolated bacteria). The mortality in the 15 days following isolation was 2%, the referred microorganisms being the most frequent responsible for the deaths. The mean of CD4 lymphocytes in the patients with enteropathogens was 0.17 x 10(9)/l). SD 0.14 x 10(9)/l). In patients with infection by Cryptosporidium the CD4 lymphocyte count was lower than that observed in the cases of infection by Isospora belli. Prior to 1988, 21% of the patients had infection by enteropathogenic bacteria and 23% by parasites, those percentages being 3% and 6%, respectively in 1991. CONCLUSIONS: Infections by enteropathogenic microorganisms in patients with infection by the human immunodeficiency virus in an advanced stage are frequent, particularly, in homosexuals. The patients with enteritis by Cryptosporidium have a greater grade of immunosuppression (CD4 lymphocytes lower than 0.1 x 10(9)/l) than patients with infection by other enteropathogenic microorganisms. In the last few years, the incidence of enteropathogenic bacteria, especially Salmonella sp. and protozoa has decreased [corrected].     

Aperture Synthesis by Object Rotation in Coherent Imaging

Doppler processing is an established method for obtaining spatial resolution of objects which exhibit radial motion relative to an observing sensor. When applied to rotating objects, Doppler processing yields resolution in cross-range along an axis normal to both object rotation and line-of-sight axes. In this case, the cross-range resolution performance is dictated by the angular interval over which the data are observed and processed. This paper treats a tomographic extension of Doppler processing in the case of a rotating object (or a rotating planar array of point scatterers). It uses a stationary, continuous-wave (CW) irradiating source and sensor, co-located in the plane being imaged. The processing of data from a rotating object is shown to be equivalent to synthesizing an aperture which is a segment of a circle, however, processing over large angular rotations requires a focusing correction. Angular rotations up to and including 2? radians are considered. For this latter condition the system simulates an annular aperture which encloses the object. With this technique, high resolution may be obtained in all directions in the object plane without the use of a wideband signal, and equal point-objects separated by a quarter wavelength may be resolved. The imaging process provides high resolution for sparse arrays of objects of similar strength which are small in comparison to a wavelength. The imaging capability in the case of dense object arrays or large objects is limited and has a restricted dynamic range.     

<Emphasis Type="SmallCaps">COVER</Emphasis>: a linguistic resource combining common sense and lexicographic information

Lexical resources are fundamental to tackle many tasks that are central to present and prospective research in Text Mining, Information Retrieval, and connected to Natural Language Processing. In this article we introduce COVER, a novel lexical resource, along with COVERAGE, the algorithm devised to build it. In order to describe concepts, COVER proposes a compact vectorial representation that combines the lexicographic precision characterizing BabelNet and the rich common-sense knowledge featuring ConceptNet. We propose COVER as a reliable and mature resource, that has been employed in as diverse tasks as conceptual categorization, keywords extraction, and conceptual similarity. The experimental assessment is performed on the last task: we report and discuss the obtained results, pointing out future improvements. We conclude that COVER can be directly exploited to build applications, and coupled with existing resources, as well.     

Normalization and interpretation of radar images

Calibrated radar images are often quantified as radar cross sections. This interpretation, which is not strictly correct, can lead to misunderstanding of test target scattering properties. To avoid confusion, we recommend that a term such as “scattering brightness” defined in the present paper be adopted as a standard label for image-domain data     

Community-acquired pneumonia in the elderly. Clinical and nutritional aspects

Community-acquired pneumonia (CAP) in the elderly has a different clinical presentation than CAP in other age groups. Confusion, alteration of functional physical capacity, and decompensation of underlying illnesses may appear as unique manifestations. Malnutrition is also an associated feature of CAP in this population. We undertook a study to assess the clinical and nutritional aspects of CAP requiring hospitalization in elderly patients (over 65 yr of age). One hundred and one patients with pneumonia, consecutively admitted to a 1,000-bed teaching hospital over an 8-mo period, were studied (age: 78 +/- 8 yr, mean +/- SD). Nutritional aspects and the mental status of patients with pneumonia were compared with those of a control population (n = 101) matched for gender, age, and date of hospitalization. The main symptoms were dyspnea (n = 71), cough (n = 67), and fever (n = 64). The association of these symptoms with CAP was observed in only 32 patients. The most common associated conditions were cardiac disease (n = 38) and chronic obstructive pulmonary disease (COPD) (n = 30). Seventy-seven (76%) episodes of pneumonia were clinically classified as typical and 24 as atypical. There was no association between the type of isolated microorganism and the clinical presentation of CAP, except for pleuritic chest pain, which was more common in pneumonia episodes caused by classical microorganisms (p = 0.02). This was confirmed by a multivariate analysis (relative risk [RR] = 11; 95% confidence interval [CI]: 1.7 to 65; p = 0.0099). The prevalence of chronic dementia was similar in the pneumonia cohort (n = 25) and control group (n = 18) (p = 0.22). However, delirium or acute confusion were significantly more frequent in the pneumonia cohort than in controls (45 versus 29 episodes; p = 0.019). Only 16 patients with pneumonia were considered to be well nourished, as compared with 47 control patients (p = 0.001). Kwashiorkor-like malnutrition was the predominant type of malnutrition (n = 65; 70%) in the pneumonia patients as compared with the control patients (n = 31; 31%) (p = 0.001). The observed mortality was 26% (n = 26). Pleuritic chest pain is the only clinical symptom that can guide an empiric therapeutic strategy in CAP (typical versus atypical pneumonia). Both delirium and malnutrition were very common clinical manifestations of CAP in our study population.     

Cefixime versus amoxicillin plus netilmicin in the treatment of community-acquired non-complicated acute pyelonephritis

BACKGROUND: Community-acquired non-complicated acute pyelonephritis (APN) is a frequent, occasionally serious infection (around 20% of the cases are bacteremic) that usually requires hospital admission. The third generation oral cephalosporins which are active against more than 95% of E. coli strains should allow the outpatient management of these patients. OBJECTIVE: To evaluate the bacteriological and clinical efficacy of oral cefixime in comparison to amoxicilin plus netilcilin in the treatment of APN. PATIENTS AND METHODS: Patients older than 18 years affected by APN were included in a fourteen month prospective study. According to a random numbers chart, the patients received cefixime (400 mg/24 h in a single daily dose for 12 days) or amoxicilin (1 g/8 h per os) plus netilmicin (4 mg/kg/24 h in a single intramuscular daily dose) during five days followed by 7 days of an oral treatment chosen according to the susceptibility pattern of isolated microorganism. RESULTS: Sixty-one patients received cefixime and 65 amoxicillin plus retilmicin. There were no significant differences between both groups of patients. Thirty-two patients presented bacteremia (25.4%). The mean (SD) eak and trough concentrations of netilmicin were 11.4 (2.8) mg/l and 0.38 (0.4) mg/l, respectively. Clinical response was favorable in 97% of patients treated with cefixime and in 98% of those treated with amoxicilin plus netilmicin (p = NS). The infection recurred in 10 out of 59 patients (16.9%) in the cefixime arm of the study and in 9 out of 64 patients (14%) treated with amoxicillin plus netilmicin (p = NS). Tolerance to the study drugs was good in both arms of the study, and renal function remained normal. CONCLUSION: Cefixime seems to be an acceptable alternative to the regimens containing an aminopenicillin and an aminoglycoside for the treatment of community-acquired non-complicated APN.     

A 277-GHz fmax transferred-substrate heterojunctionbipolar transistor

We report a AlInAs-GaInAs transferred-substrate heterojunction bipolar transistor (HBT). The transferred-substrate process permits fabrication of narrow and aligned collector-base and emitter-base junctions, reducing the collector-base capacitance and increasing the device f_max. A device with aligned 0.7-μm emitter and 1.6-μm collector stripes has extrapolated 277 GHz f_max and 127 GHz f_τ, respectively