Erosion resistance and behaviour of highly organic in-sewer sediment.

Reliable prediction of time-varying pollutant loads in combined sewer systems during storm periods can aid better management of the release of pollution into natural environments as well as enhancing storage tank design. Better understanding of the behaviour of sewer sediments is crucial for the development of models that adequately describe the transport of in-sewer solids and accurately predict the changes in pollutant concentration within combined sewers during storm events. This paper reports on the results of a test programme to examine the erosion of highly organic sewer sediment under the application of time-varying shear stress. The tests were carried out with and without supplying oxygen, and varying simulated dry-weather periods. The aim was to investigate the behaviour of real in-sewer sediment with a high organic content (around 80%) in an attempt to improve prediction of the transport rates under the particular Mediterranean conditions of long dry-period/build-up and intense rainfall/wash-off, and understand how this environment affects the erosional resistance and subsequent sediment release. Results have been compared with previous work on lower organic content sewer sediments and artificial organic sediment.

Usefulness of rNcGRA7- and rNcSAG4-based ELISA tests for distinguishing primo-infection, recrudescence, and chronic bovine neosporosis.

Bovine reproductive failure caused by the parasite Neospora caninum is a major problem and is responsible for severe economic losses worldwide. Currently, appropriate control measures depend on the predominant transmission route in a particular herd. Therefore, the development of diagnostic tools capable of discriminating between primo-infection, recrudescence, re-infection, and chronic infection is a major challenge in the serodiagnosis of bovine neosporosis. Here, two recombinant protein-based ELISAs utilizing the immunodominant NcGRA7 dense granule protein and the NcSAG4 bradyzoite stage-specific protein were developed and showed good diagnostic performances. Their usefulness for discerning between primo-infection, recrudescence, re-infection, and chronic infection was also studied by analyzing an appropriate panel of serum samples belonging to different groups of experimentally and naturally infected bovines. Our results suggest that anti-rNcGRA7 antibody levels may be indicative of acute infection (primo-infection, re-infection, and recrudescence), whereas the presence of anti-rNcSAG4 antibodies may be associated with chronic infection and could be a good indicator of infection establishment (tachyzoite-bradyzoite conversion). Moreover, primo-infection associated with a Neospora-associated epidemic abortion pattern is characterized by the detection of anti-rNcGRA7 antibodies together with the absence or detection of anti-rNcSAG4 antibody levels around the cut-off point. In contrast, the detection of antibody levels directed against both recombinant proteins may be quite indicative of recrudescence or re-infection associated with abortion and/or vertical transmission in herds with a Neospora-associated endemic abortion pattern. In conclusion, both serological tests developed in the present study offer additional information to conventional avidity tests and, consequently, improve the diagnosis of bovine neosporosis with perspectives for control measures.

Comparison of Neospora caninum distribution, parasite loads and lesions between epidemic and endemic bovine abortion cases.

It has been suggested that the abortion herd pattern could influence bovine foetal neosporosis. Here, a comparison of (i) Neospora caninum DNA-detectability by PCR, (ii) N. caninum-associated lesions and (iii) parasite loads in target organs was made between epidemic and endemic abortion cases. We observed that N. caninum DNA was predominantly detected in more than one organ in the foetuses from herds with epizootic rather than endemic abortion cases (P<0.05, Fisher F-test). The highest parasite burdens were found in the heart in foetuses from outbreaks of epidemic abortion and in the brain in endemic cases (P<0.05, Kruskal-Wallis H-test). Moreover, foetuses from epidemic outbreaks had significantly higher parasite burdens in heart (P<0.05, Mann-Whitney U-test) than endemic abortion cases. Epidemic abortion cases showed higher lesion frequencies in liver (P<0.05, Fisher F-test). This report confirms that the abortion herd pattern is an important factor that influences pathogenesis in natural N. caninum infections.

Use of avidity enzyme-linked immunosorbent assay and avidity Western blot to discriminate between acute and chronic Neospora caninum infection in cattle.

Avidity serological tests (avidity enzyme-linked immunosorbent assay [ELISA] and avidity Western blot) were developed and used to differentiate between acute (primary infection, reinfection, and recrudescence) and chronic Neospora caninum infection in cattle. In addition, the pattern of immunoglobulin G (IgG) avidity maturation against different specific antigens of N. caninum tachyzoites was studied. Sequential serum samples were collected from cattle naturally and experimentally infected with N. caninum. Four groups of experimentally infected cattle were included in the study and were representative of primary infection, reinfection, chronic infection, and noninfection. Serum samples were also collected from naturally infected cattle classified into nonaborting and aborting cows on the basis of clinical findings and serological profiles, and a third group composed of seronegative cows that seroconverted during the course of the experiment. All samples were tested by avidity ELISA and avidity Western blot. The IgG avidity ELISA allowed the discrimination between primary and chronic infection because all experimentally primary-infection cows showed low avidity indexes at week 4 postinfection (p.i.) compared with the high avidity values found at week 20 postinfection. However, this test did not allow the discrimination of reinfection or recrudescence from chronic infection. Regarding IgG avidity Western blot results, no antigenic markers correlating with acute (primary infection, recrudescence, and reinfection) or chronic infection were recognized. However, the 17-kD immunodominant antigen was mostly responsible for high avidity values obtained by avidity ELISA because it was intensively recognized by high-avidity antibodies in all chronically infected animals after urea treatment.

Reduction of AOX in the bleach plant of a pulp mill.

The reconfiguration of an existing five-stage bleaching D0E1D1E2D2 sequence is proposed to ensure the minimal formation of organochlorine compounds, expressed as AOX, in the bleach plant of a kraft pulp mill processing Eucalyptus globulus wood. This reduction of the load of AOX in the effluents can be achieved without introducing new and expensive technologies in the bleaching process. In practice, this goal can be achieved by eliminating the washing step between the D0 and the E1 stages. With this strategy, the total AOX in the liquid effluent of the bleach plant can be reduced by almost 65% while maintaining a level of 90% ISO brightness of the pulp and even diminishing the degradation of its polysaccharides. With this process redesign, the total AOX discharge from the bleach plant can be decreased from 1.2 to 0.42 kg/t prior to any biological treatment. Furthermore, the proposed modified (D0E1)D1E2D2 sequence enables the reduction of the total flow rate of effluent to be treated and also the total consumption of water, which is quite critical in these types of plants. Moreover, with this strategy, one is able to move the first drum washer of a conventional bleaching sequence to the entrance of the bleach plant. This gives rise to a cleaner pulp and therefore to lower requirements of chlorine dioxide, which in turn will enable further reductions in the global AOX generation.

Estudio comparativo de la eficacia resucitadora de Ringer lactato, gelatinas y solución salina hipertónica al 2 por ciento en un modelo experimental canino de hemorragia aguda / Comparative study of the resuscitation efficacy of lactated Ringer's solution, gelatins and 2 por ciento hypertonic saline solution in an experimental canine model of acute hemorrhage

Objetivo. Estudiar la eficacia resucitadora de tres tipos de fluidos (Ringer lactato, gelatinas y solución salina hipertónica al 2 por ciento) en un modelo canino de hemorragia aguda. Material y método. Se estudiaron 18 perros anestesiados y monitorizados sometidos a hemorragia gradual. De forma aleatorizada se realizó la resucitación con Ringer lactato (3 ml por ml de sangre extraída) (n = 6), con gelatinas (1 ml por ml de sangre extraída) (n = 6), y con solución salina hipertónica al 2 por ciento (1 ml por ml de sangre extraída) (n = 6). Resultados. Los tres tipos de fluidos fueron eficaces en la resucitación según los parámetros clásicos (presión arterial, gasto cardíaco y presiones de llenado cardíacas). Las gelatinas incrementaron en mayor medida el gasto cardíaco, el transporte del O2 y el consumo de O2. El Ringer lactato incrementó el shunt pulmonar. Conclusiones. Las gelatinas poseen mayor eficacia resucitadora que el Ringer lactato según los parámetros estudiados. La solución salina hipertónica al 2 por ciento no es superior al Ringer lactato o las gelatinas a pesar de incrementar significativamente la natremia. (AU)

Papillary cystic tumor of the pancreas coexisting with hairy cell leukemia.

The coexistence of a pancreatic papillary cystic tumor with hairy cell leukemia is reported. To the best of our knowledge this association has never been published. A 41-year-old man diagnosed with hairy cell leukemia developed a second malignancy that corresponded to a papillary cystic pancreatic tumor. The patient underwent splenectomy and a tumoral surgical resection, and is currently well at 21 months follow-up. A pathogenetic relationship between the two malignancies was not demonstrated. Hairy cell leukemia has been reported to be associated to a great number of different second malignancies. In contrast, only two papillary cystic tumors of the pancreas have been described associated to a second neoplasm, a papillary thyroid carcinoma and a colonic carcinoma. This unusual benign or low-grade malignant pancreatic tumor more commonly occurs in the tail of the pancreas of young women. We want to stress the unusual presentation of this pancreatic tumor affecting the head of the gland in a male patient as well as its coexistence with a hairy cell leukemia.

[Changes in PCO2 and pH gradients in a canine model of experimental acute hemorrhage]. / Modificaciones de las diferencias arteriovenosas de PCO2 (Da-vPCO2) y pH (Da-vpH) en un modelo experimental canino de hemorragia aguda.

OBJECTIVE: To study changes in arterial-venous PCO2 pressures (Da-vPCO2) and in pH (Da-vpH) in an experimental dog model of acute bleeding. To emphasize the utility of monitoring these variables in situations of acute bleeding. ANIMALS AND METHOD: Eighteen dogs were anesthesized and monitored while being subjected to gradual bleeding. Gasometric and hemodynamic variables were recorded at the following moments: baseline, stage I (15% of volemic loss), stage Ib (20%), stage II (25%), stage IIb (30%) and stage III (35%). RESULTS: No significant differences in pH or PCO2 in either arterial or mixed venous blood were found. Bleeding induced a constant and progressive increase in Da-vPCO2 that correlated with changes in volume (r = -0.56, p < 0.001), SvO2 (r = 0.71; p < 0.001), Da-vO2 gradient (r = 0.62; p < 0.001) and cardiac output (r = 0.63; p < 0.001). CONCLUSIONS: Gradual bleeding caused a constant and significant increase of Da-vPCO2. Monitoring such changes in states of circulatory insufficiency may be useful for evaluating tissue ischemia.

C-reactive protein and leukocyte count in the diagnosis of acute appendicitis in children.

PURPOSE: The aim of this study was to analyze the diagnostic accuracy of C-reactive protein and its possible advantage, if any, over leukocyte counts in acute appendicitis in children. METHODS: We performed a retrospective study of 124 children (72 males) with a mean age of 9.3 (range, 2-14) years operated on under a clinical diagnosis of acute appendicitis. The diagnosis of acute appendicitis, confirmed by pathologic examination of the removed appendix, was then correlated with C-reactive protein, leukocyte count, and a combination of both C-reactive protein and leukocyte count, with a logistic regression model. C-reactive protein serum measurements were performed by an immunoturbidimetric test. The patients were divided into two groups according to the pathologic features of the removed appendix: Group A (n = 104), patients with acute appendicitis, and Group B (n = 20), patients without acute appendicitis. To assess the accuracy of C-reactive protein, leukocyte counts, and a combination of both parameters, receiver operating characteristic curves were used. The areas under the curve were compared using the maximum likelihood estimation method. RESULTS: There were 95 cases (76.6 percent) of nonperforated appendicitis, 9 cases (7.3 percent) of perforated appendicitis and 20 cases (16.1 percent) of normal appendix. Mean C-reactive protein in Group A was 4.3 (standard deviation, 6.6) and in Group B was 1.2 (standard deviation, 1.7; P = 0.03). The C-reactive protein and leukocyte count values were correlated with the pathologic diagnosis of acute appendicitis. Mean C-reactive protein values increase as the pathologic inflammation type progresses (P = 0.007). The C-reactive protein receiver operating characteristic curve shows that the C-reactive protein value with highest accuracy was 1.7 mg/dl. The sensitivity, specificity, and accuracy rates calculated in the 1.7 cutoff were 58, 80, and 83.8 percent, respectively. A comparison of the respective receiver operating characteristic curves demonstrates that C-reactive protein, leukocyte count, and the combination of both tests all have a good diagnostic value but without any significant difference (P = 0.2). CONCLUSIONS: In children, 1) serum C-reactive protein is increased in acute appendicitis; 2) such increase is related to the severity of the appendiceal inflammation; and 3) although serum C-reactive protein has an adequate diagnostic accuracy, neither individually nor in combination with the leukocyte count is it significantly better than the leukocyte count alone.