Predictive factors of mortality in severe community-acquired pneumonia: A model with data on the first 24h of ICU admission

OBJECTIVE: To construct a model of factors predicting mortality in severe community-acquired pneumonia (SCAP) with data on the first 24h after admission to the intensive care unit (ICU). DESIGN: A prospective, observational study was carried out. SETTING: The ICU of a university hospital. PATIENTS: ICU-admitted patients with SCAP were studied prospectively. INTERVENTIONS: Admission pneumonia scores were calculated, and clinical variables were registered during the first 24h. Relationships between predictors of mortality at 28 days were assessed by means of a multivariate logistic regression model. RESULTS: A total number of 242 SCAP patients were evaluated. The SAPS II severity score was 37.2 ± 15.5 points. Bivariate analysis showed high mortality to be more frequent in elderly patients, as well as in patients with high SAPS II scores, neoplastic disease or chronic renal failure. The other prognostic factors related to increased mortality included mechanical ventilation, acute respiratory distress syndrome (ARDS), acute renal failure, bacteremia, and septic shock. Mortality at 28 days was 23.1% (56 patients). Multivariate analysis of the risk factors generated a new predictive model of mortality applicable within the first 24 h after ICU admission and comprising 5 main factors: age, CURB severity score 3-4, septic shock, ARDS, and acute renal failure. CONCLUSIONS: Age in years, CURB score 3-4, septic shock, ARDS, and acute renal failure during the first 24h of ICU admission were found to be independent predictors of mortality in SCAP patients

OBJETIVO: Construir un modelo de factores predictivos de mortalidad en la neumonía adquirida en la comunidad grave (NACG) utilizando los datos de las primeras 24h de ingreso en la unidad de cuidados intensivos (UCI). DISEÑO: Estudio prospectivo y observacional. Ámbito: UCI de un hospital universitario. PACIENTES: Se estudiaron de forma prospectiva los pacientes ingresados en la UCI con el diagnóstico de NACG. INTERVENCIONES: Se calcularon las escalas de neumonía y se registraron las variables clínicas en las primeras 24h del ingreso en la UCI. Para evaluar los factores predictores de mortalidad a los 28 días, se construyó un modelo multivariado de regresión logística. RESULTADOS: Un total de 242pacientes con NACG fueron analizados. La puntuación de gravedad por el SAPSII fue de 37,2±15,5 puntos. El análisis bivariado mostró una mayor mortalidad en pacientes de edad avanzada, con una puntuación de SAPSII alta, enfermedad neoplásica o insuficiencia renal crónica. Otros factores pronóstico relacionados con el aumento de la mortalidad fueron la ventilación mecánica, el síndrome de distrés respiratorio agudo (SDRA), la insuficiencia renal aguda, y el shock séptico o la bacteriemia. La mortalidad a los 28días fue del 23,1% (56pacientes). El análisis multivariado de los factores de riesgo permitió construir un nuevo modelo predictivo de mortalidad aplicable en las primeras 24h de ingreso en la UCI, que consistió en 5 factores: edad, CURB score 3-4, shock séptico, SDRA e insuficiencia renal aguda. CONCLUSIONES: La edad en años, el CURB score 3-4, el shock séptico, el SDRA y la insuficiencia renal aguda evaluados en las primeras 24h de ingreso en la UCI fueron factores de riesgo independientes de mortalidad en pacientes con NACG

Predictive factors of mortality in severe community-acquired pneumonia: a model with data on the first 24h of ICU admission.

OBJECTIVE: To construct a model of factors predicting mortality in severe community-acquired pneumonia (SCAP) with data on the first 24h after admission to the intensive care unit (ICU). DESIGN: A prospective, observational study was carried out. SETTING: The ICU of a university hospital. PATIENTS: ICU-admitted patients with SCAP were studied prospectively. INTERVENTIONS: Admission pneumonia scores were calculated, and clinical variables were registered during the first 24h. Relationships between predictors of mortality at 28 days were assessed by means of a multivariate logistic regression model. RESULTS: A total number of 242 SCAP patients were evaluated. The SAPS II severity score was 37.2±15.5 points. Bivariate analysis showed high mortality to be more frequent in elderly patients, as well as in patients with high SAPS II scores, neoplastic disease or chronic renal failure. The other prognostic factors related to increased mortality included mechanical ventilation, acute respiratory distress syndrome (ARDS), acute renal failure, bacteremia, and septic shock. Mortality at 28 days was 23.1% (56 patients). Multivariate analysis of the risk factors generated a new predictive model of mortality applicable within the first 24h after ICU admission and comprising 5 main factors: age, CURB severity score 3-4, septic shock, ARDS, and acute renal failure. CONCLUSIONS: Age in years, CURB score 3-4, septic shock, ARDS, and acute renal failure during the first 24h of ICU admission were found to be independent predictors of mortality in SCAP patients.

Copper(II) complexation by humic and fulvic acids from pig slurry and amended and non-amended soils.

The effect of the consecutive annual additions of pig slurry at rates of 0 (control), 90 and 150 m3 ha(-1) y(-1) over a 4-year period on the binding affinity for Cu(II) of soil humic acids (HAs) and fulvic acids (FAs) was investigated in a field plot experiment under semiarid conditions. A ligand potentiometric titration method and a single site model were used for determining the Cu(II) complexing capacities and the stability constants of Cu(II) complexes of HAs and FAs isolated from pig slurry and control and amended soils. The HAs complexing capacities and stability constants were larger than those of the corresponding FA fractions. With respect to the control soil HA, pig-slurry HA was characterized by a much smaller binding capacity and stability constant. Amendment with pig slurry decreased the binding affinity of soil HAs. Similar to the corresponding HAs, the binding affinity of pig-slurry FA was much smaller while that of amended-soil FAs were slightly smaller when compared to the control soil FA. The latter effect was, however, more evident with increasing the amount of pig slurry applied to soil per year and the number of years of pig slurry application.

Identification of the bacteriochlorophyll homologues of Chlorobium phaeobacteroides strain UdG6053 grown at low light intensity.

Detailed APCI LC-MS/MS analysis using an improved HPLC separation reveals the green sulphur bacterium Chlorobium phaeobacteroides strain UdG6053 to contain a wider range of distinct bacteriochlorophyll homologues than has been previously recognised in Chlorobiaceae. The diversity in the homologue distribution is confirmed as arising from differences in the extent of alkylation of the macrocycle and variation in the nature of the esterifying alcohol and a novel series of bacteriochlorophyll structures has been recognised. Homologues containing esterifying alcohols other than farnesol, a number of which have not previously been reported in Chlorobiaceae, are present in high relative abundance. Confirmation of the structures of the esterifying alcohols has been obtained by hydrolysis and analysis by GC-MS.

Previously unknown and phylogenetically diverse members of the green nonsulfur bacteria are indigenous to freshwater lakes.

The phylogenetic diversity of green nonsulfur bacteria in nine stratified freshwater lakes was investigated. A set of oligonucleotide primers was developed that permitted the selective amplification of 16S rRNA gene sequences of this group. Subsequently, amplification products were separated by denaturing gradient gel electrophoresis (DGGE) and sequenced, which yielded a total of 19 novel sequence types. Ten of the sequences were related to those of different cultivated members of the C hloroflexus assemblage, whereas nine fell into the T78 group of environmental clones. For the latter subgroup of the green nonsulfur bacteria, no molecular isolate from freshwater plankton has been reported so far. Several of the sequence types occurred in more than one lake, indicating that not only relatives of the C hloroflexus assemblage, but also bacteria of the clone T78 group represent indigenous bacteria of nonthermal stratified freshwater ecosystems. Our results indicate that the natural diversity in the phylum of the green nonsulfur bacteria has been significantly underestimated in the past.

Nanosecond laser photolysis studies of chlorosomes and artificial aggregates containing bacteriochlorophyll e: evidence for the proximity of carotenoids and bacteriochlorophyll a in chlorosomes from Chlorobium phaeobacteroides strain CL1401.

Time-resolved, laser-induced changes in absorbance, delta A(lambda; t), have been recorded with a view to probing pigment-pigment interactions in chlorosomes (control as well as carotenoid-depleted) and artificial aggregates of bacteriochlorophyll e (BChle). Control chlorosomes were isolated from Chlorobium phaeobacteroides strain CL1401, whose chromophores comprise BChle, bacteriochlorophyll a (BChla) and several carotenoid (Car) pigments; Car-depleted chlorosomes, from cells grown in cultures containing 2-hydroxybiphenyl. Artificial aggregates were prepared by dispersing BChle in aqueous phase in the presence of monogalactosyl diglyceride. In chlorosomes delta A(lambda; t) shows, besides a signal attributable to triplet Car (with a half-life of about 4 microseconds), signals in the Qy regions of both BChl. The BChla signal decays at the same rate as the Car signal, which is explained by postulating that some Car are in intimate contact with some baseplate BChla pigments, and that when a ground-state Car changes into a triplet Car, the absorption spectrum of its BChla neighbors undergoes a concomitant change (termed transient environment-induced perturbation). The signal in the Qy-region of BChle behaves differently: its amplitude falls, under reducing conditions, by more than a factor of two during the first 0.5 microsecond (a period during which the Car signal suffers negligible diminution), and is much smaller under nonreducing conditions. The BChle signal is also attributed to transient environment-induced perturbation, but in this case the perturber is a BChle photoproduct (probably a triplet or a radical ion). The absence of long-lived BChle triplets in all three systems, and of long-lived BChla triplets in chlorosomes, indicates that BChle in densely packed assemblies is less vulnerable to photodamage than monomeric BChle and that, in chlorosome, BChla rather than BChle needs, and receives, photoprotection from an adjacent Car.

Effect of carotenoid biosynthesis inhibition on the chlorosome organization in Chlorobium phaeobacteroides strain CL1401.

We have studied the effect of the absence of carotenoids on the organization of bacteriochlorophylls (BChls) in chlorosomes of Chlorobium (Chl.) phaeobacteroides strain CL1401. Carotenoid-depleted chlorosomes were obtained by means of 2-hydroxybiphenyl-supplemented cultures. In the presence of the inhibitor, isorenieratene (Isr) and beta-Isr biosynthesis were inhibited to more than 95%, leading to an accumulation of the colorless precursor phytoene inside the chlorosomes. In addition, there was a 30-40% decrease in the baseplate BChl a content. The absorption spectrum of the carotenoid-depleted chlorosomes showed a 10 nm blue shift in the BChl e Qy absorption peak. Under reducing conditions, a decrease in the BChl a/BChl e fluorescence emission ratio was observed in carotenoid-depleted chlorosomes relative to that in control chlorosomes, caused mainly by the decrease in the BChl a content. The steady-state fluorescence emission anisotropy in the BChl e region dropped from approximately 0.24 for native chlorosomes to approximately 0.14 for carotenoid-depleted ones, indicating reorganization of BChl e. The circular dichroism (CD) signal of the carotenoid-depleted chlorosomes was increased two times in the BChl e Qy region. A simple model based on the structure proposed was used to explain the observed effects. Carotenoids might affect the angle between the direction of the BChl e Qy transition and the axis of the rod. The orientation of BChl a in the baseplate remains unchanged in carotenoid-depleted chlorosomes, although there is a partial loss of BChl a as a consequence of a decrease in the baseplate size. The carotenoids are most likely rather close to the BChls and appear to be important for the aggregate structure in Chl. phaeobacteroides.

Fast energy transfer between BChl d and BChl c in chlorosomes of the green sulfur bacterium Chlorobium limicola.

We have studied energy transfer in chlorosomes of Chlorobium limicola UdG6040 containing a mixture of about 50% bacteriochlorophyll (BChl) c and BChl d each. BChl d-depleted chlorosomes were obtained by acid treatment. The energy transfer between the different pigment pools was studied using both steady-state and time-resolved fluorescence spectroscopy at room temperature and low temperature. The steady-state emission of the intact chlorosome originated mainly from BChl c, as judged by comparison of fluorescence emission spectra of intact and BChl d-depleted chlorosomes. This indicated that efficient energy transfer from BChl d to BChl c takes place. At room temperature BChl c/d to BChl a excitation energy transfer (EET) was characterized by two components of 27 and 74 ps. At low temperature we could also observe EET from BChl d to BChl c with a time constant of approximately 4 ps. Kinetic modeling of the low temperature data indicated heterogeneous fluorescence kinetics and suggested the presence of an additional BChl c pool, E790, which is more or less decoupled from the baseplate BChl a. This E790 pool is either a low-lying exciton state of BChl c which acts as a trap at low temperature or alternatively represents the red edge of a broad inhomogeneous absorption band of BChl c. We present a refined model for the organization of the spatially separated pigment pools in chlorosomes of Cb. limicola UdG6040 in which BChl d is situated distal and BChl c proximal with respect to the baseplate.

Computerized tomographic assessment of the composition of gallstones.

We present the results of an in vitro study of biliary lithiasis (n = 106) with computerized tomography (CT). We analyzed the correlation between composition of gallstones (crystallographic analysis of thin sections and atomic absorption spectrophotometric analysis of total calcium content) with CT patterns (densitometry) and their corresponding attenuations. Six main CT patterns were distinguished: hypodense (homogeneous and heterogeneous), dense, homogeneous hyperdense, ringed hyperdense and irregular hyperdense. Statistically significant differences (p < 0.05) were found between attenuations for cholesterol (mixed and pure) and pigmentary stones. We found a good inverse correlation between attenuations and cholesterol content; the contents of pigment, inorganic calcic salts and total calcium content also showed significant direct correlations (p < or = 0.01). Of the samples classified as pure cholesterol type stones, 86.4% showed hypodense patterns, and the remaining 13.6% showed irregular hyperdense patterns. Of the pigmentary stones, 80% showed homogeneous hyperdense images. All stones that contained more than 3% calcium produced hyperdense patterns, whereas 72.4% of the stones that contained less calcium produced hypodense images. Tomodensitometric measurements provided more information than simple radiography, and made it possible to distinguish a greater variety of gallstone types based on structural complexity.

Structure and composition of freshwater microbial mats from a sulfur spring ("Font Pudosa", NE Spain).

Different types of microbial mats developing on the wall on a non-thermal sulfur freshwater spring have been studied. Both, light and electron microscopy as well as HPLC analysis of photosynthetic pigments revealed their structure and composition. Prokaryotic chlorophylls and carotenoids helped in the taxonomical assignment of the main photosynthetic groups. "Inverted position" mats (Mat-I) were dominated by Chromatiaceae; they were located closed to the water outlets (0.3 mM sulfide). "Normal position", that is, cyanobacterial-covered mats (Mat-II and Mat-IV), developed elsewhere on the stone walls at lower sulfide concentrations. A third type of mat (Mat-III), covered by chemolithotrophic bacteria, was distinguishable at the water-air interface, strongly attached to the walls of the spring. Up to six physiological types of microorganisms have been recognized: cyanobacteria, Chromatiaceae, purple nonsulfur bacteria. Chlorobiaceae, Chloroflexaceae, and chemolithotrophic bacteria. Cyanobacteria Lyngbya-like, Oscillatoria-like and Pseudanabaena sp. were found. The diversity of Chromatiaceae (six morpho-/pigment types of the genus Chromatium, plus two non identified Chromatiaceae, named PB1 and PB2 were observed) was noticeable. Chemolithotrophic bacteria were represented by the genera Beggiatoa and Thiothrix. Finally, small numbers of Chloroflexus-like bacteria and Chlorobium limicola were found in all the studied mats.

Sorption of metals by Chlorobium spp.

The capacity of two species of green phototrophic sulfur bacteria, Chlorobium limicola and C. phaeobacteroides, to sorb several metal ions (Mn2+, Fe2+, Ni2+, Cu2+, Zn2+, Cd2+ and Pb2+) has been tested in laboratory batch cultures at increasing concentrations up to 2,000 mumol/l. Except for nickel--which was not sorbed to bacterial cells--the rest of metals tested were bound in a fast and passive process, which was mathematically described by means of Freundlich isotherms models. The sorption capacity of the two species studied were found to be dependent on the metal involved, whereas no differences were observed in the sorption intensity, suggesting that in all cases the sorption process proceeds in a similar way. Further, the comparison of the sorption intensity values as well as the metal recovery index (Ri), for both species, revealed that C. phaeobacteroides was more efficient that C. limicola to attach metal ions. The ecological significance of this ability in the water column of some stratified lakes, where coinciding maxima of ferrous iron and green photosynthetic sulfur bacteria are frequently found, is discussed.

Photosynthetic oxidation of MnS and FeS by Chlorobium spp.

The ability of two species of green phototrophic sulfur bacteria (Chlorobium limicola and Chlorobium phaeobacteroides) to photosynthetically oxidize several metal sulfides (MnS, FeS, NiS, CuS, ZnS, CdS and PbS) by has been tested in laboratory batch cultures. Both species only oxidized MnS and FeS, which are the ones having higher solubilities (pKs = 13.5 and 18.1, respectively). The specific oxidation rates were directly related to the solubility of the metal sulfide involved. C. limicola oxidized MnS and FeS at specific rates of 11.8 and 0.9 mumol S2-h-1 mg protein-1, respectively. Specific oxidation rates of C. phaeobacteroides for MnS and FeS were 7.1 and 1.8 mumol S2-h-1 mg protein-1, respectively. The oxidation of both metal sulfides resulted in the release of the free-soluble metal ions in the culture media, but no toxic effect of these cations on the photosynthetic activity of the cells was observed. The anaerobic photosynthetical oxidation of MnS and FeS by Chlorobium reveals an adaptation of this bacterial species to sulfide-poor environments, and introduces a new process in the Mn, Fe, and S biogeochemical cycles to be considered.

Postoperative decline in plasma aspirin-esterase and cholinesterase activity in surgical patients.

We studied preoperative and postoperative plasma hydrolysis of aspirin and plasma cholinesterase activity in surgical patients. Postoperative aspirin esterase and cholinesterase activities fell sharply (119 +/- 32 micrograms ml h-1 and 3746 +/- 1068 U l-1 respectively; P < 0.01) in comparison to basal preoperative values (157 +/- 33 micrograms ml h-1 and 4620 +/- 940 U l-1 respectively, P < 0.01). We suggest that alterations in plasma esterase during the postoperative period may be related to the metabolic response to anesthesia- and surgery-induced stress.

[A 12-year retrospective study of 114 cases of proximal gastric vagotomy]. / Estudio retrospectivo de doce años en 114 casos de vagotomía gástrica proximal.

We present 114 cases of proximal gastric vagotomy (VGP), performed between December 1975 an December 1986 (11 years) and followed-up until December 1987 (12 years). An hundred patients underwent elective surgery and 14 emergency. We obtained good results in 97 patients (85.83%) moderate in 10 (8.85%) and poor in six (5.30%) with one mortality (0.87%) due to causes not related to the operation. We emphasize the surgical indication and technique, which, if correctly established, make proximal gastric vagotomy the ideal surgical intervention for gastroduodenal ulcer.