Sampling, testing and modeling particle size distribution in urban catch basins.

The study analyzed the particle size distribution of particulate matter (PM) retained in two catch basins located, respectively, near a parking lot and a traffic intersection with common high levels of traffic activity. Also, the treatment performance of a filter medium was evaluated by laboratory testing. The experimental treatment results and the field data were then used as inputs to a numerical model which described on a qualitative basis the hydrological response of the two catchments draining into each catch basin, respectively, and the quality of treatment provided by the filter during the measured rainfall. The results show that PM concentrations were on average around 300 mg/L (parking lot site) and 400 mg/L (road site) for the 10 rainfall-runoff events observed. PM with a particle diameter of <45 µm represented 40-50% of the total PM mass. The numerical model showed that a catch basin with a filter unit can remove 30 to 40% of the PM load depending on the storm characteristics.

Characterization of the settling process for wastewater from a combined sewer system.

Among the methods used for determining the parameters necessary for design of wastewater settling tanks, settling column tests are used most commonly, because of their simplicity and low costs. These tests partly mimic the actual settling processes and allow the evaluation of total suspended solids (TSS) removal by settling. Wastewater samples collected from the Liguori Channel (LC) catchment in Cosenza (Italy) were subject to settling column tests, which yielded iso-removal curves for both dry and wet-weather flow conditions. Such curves were approximated well by the newly proposed power law function containing two empirical parameters, a and b, the first of which is the particle settling velocity and the second one is a flocculation factor accounting for deviations from discrete particle settling. This power law function was tested for both the LC catchment and literature data and yielded a very good fit, with correlation coefficient values (R(2)) ranging from 0.93 to 0.99. Finally, variations in the settling tank TSS removal efficiencies with parameters a and b were also analyzed and provided insight for settling tank design.

Management of combined sewer overflows based on observations from the urbanized Liguori catchment of Cosenza, Italy.

This paper examines an urbanized catchment in Cosenza, Italy where an off-line basin intercepting CSOs was studied to illustrate reduction in CSO discharges to the Crati River. While the hydrologic transport of pollutant mass is never known a-priori and can be flow-limited, the volumetric requirements of the basin were modeled based on the classic assumption that wet weather flows transport urban and sewer loads in a mass-limited (first-flush) delivery. The volumetric capacity of the basin was varied from 10 to 50 m(3)/ha. Operational basin control was simulated with historical datasets from the Liguori catchment, event-based loading data, and continuous simulation modelling with SWMM. Utilizing data from the catchment, the SWMM simulations were conducted considering the storage basin with or without sedimentation treatment. Results illustrate the potential benefits of the off-line operation for the system with respect to the volume and mass reduction of CSOs into the Crati River. Results demonstrate the importance of particle size distribution (PSD) as an index of basin efficiency, coupled with analysis of the hydrodynamic response of the basin. The basin model attenuated influent PSDs, separating the coarser fraction of the PSD, and reduced the load of influent particulate matter (PM).

CSO treatment strategy based on constituent index relationships in a highly urbanised catchment.

In urbanising catchments the variability of particulate matter (solids) and oxygen demanding constituents of wet weather and dry weather characteristics result in variable treatment effectiveness from physical unit operations and biological unit processes. Higher organic concentrations during dry weather flow are more amenable to biological unit processes while the higher inorganic loads generated largely by urban wet weather constituents and much larger flows can be more effectively treated or conditioned by physical unit operations, including ideally preceded by hydrologic controls. This study examines the relationships between total chemical oxygen demand (COD)(t), dissolved chemical oxygen demand (COD)(d), particulate chemical oxygen demand (COD)(p) and solids, measured as total suspended solids (TSS). Results also provide an index for selection and optimisation of treatment operations for combined sewer overflow (CSO) loads.

Assessment of erythrocyte shape by flow cytometry techniques.

BACKGROUND: Red blood cell (RBC) rheology is altered in different diseases, including acute conditions such as patients in intensive care units (ICU) with sepsis or with an inflammatory reaction due to postoperative states or intracerebral haemorrhage, or chronic conditions such as diabetes mellitus or terminal renal failure. Several techniques are available to assess alterations in RBC rheology, especially deformability, but they are too cumbersome to be used on a large number of cells. OBJECTIVE: To develop a new, rapid flow cytometry technique for easy assessment of RBC shape in patients. METHODS: In flow cytometry, healthy human RBC shape shows a bimodal distribution related to the biconcave form. On this histogram, the second Pearson coefficient of dissymmetry (PCD) representing the asymmetry of this histogram and the spherical index (M2:M1) were calculated, both representing the spherical shape. This technique was used in healthy volunteers (n=17) and in diseases characterised by abnormalities in RBC rheology, including terminal renal failure requiring haemodialysis (n=28), diabetes mellitus (n=18), sepsis (n=19) and acute inflammatory states (postoperative, intracerebral haemorrhage, chronic obstructive pulmonary disease, epilepsy or severe drug intoxication; n=21). Multivariate analysis was performed to determine the factors influencing RBC shape. RESULTS: Measurement of RBC shape was highly reproducible. A good correlation was observed between the PCD and the spherical index, except in the critically ill patients without sepsis. RBCs were more spherical in patients with terminal renal failure (PCD -0.56 (0.14), p<0.05), diabetes mellitus (PCD -0.59 (0.23), p<0.05), sepsis (PCD -0.58 (0.22), p<0.05) or an acute inflammatory state (PCD -0.65 (0.29), p<0.05) than in healthy volunteers (PCD -0.89 (0.12)). The spherical index was also increased in all populations compared with healthy volunteers (terminal renal failure 2.30 (0.20); diabetes mellitus 2.27 (0.38); sepsis 2.28 (0.37); acute inflammatory state 2.35 (0.42) vs healthy volunteers 2.72 (0.47); all p<0.05). Multivariate analysis demonstrated that the underlying pathology (sepsis, acute inflammatory state, diabetes mellitus, terminal renal failure) was the principal cause of these RBC shape abnormalities. CONCLUSION: RBCs are characterised by an increased spherical shape in many disease states. The measure of the second PCD in flow cytometry is a new, easy method to investigate RBC shape in various diseases. This technique could facilitate the investigation of abnormalities of RBC rheology.

The role of in situ unit operation/process infiltration treatment on partitioning and speciation of rainfall-runoff.

Management decisions regarding the potential fate and toxicity of anthropogenic metal elements requires a knowledge of metal partitioning and speciation as mediated by in situ control systems (ICS). This study focussed on Cd, Zn, Cu and Pb, common anthropogenic metal elements generated in the built environment and examined the influence of variable event-based hydrology and passive ICS by an engineered partial exfiltration reactor (PER) system on partitioning and speciation. The feasibility and efficiency of the PER as an in situ stormwater runoff control strategy to attenuate levels of metal elements was evaluated. Results indicate that higher rainfall intensity resulted in higher dissolved fraction (fd) values for influent Zn, Cu and Cd, but did not have a significant influence on partitioning of Pb. Speciation indicated that divalent fractions of Cd, Zn, Cu and Pb were changed marginally by the PER. Cu and Pb mainly complexed with organic matter in the influent, while carbonate complexes of these metals in the effluent significantly increased. The PER consistently and statistically reduced all loadings of Cd, Cu, Pb and Zn for all examined events, whether on a mass or concentration basis. As an unsaturated flow unit operation/process the PER can efficiently remove ionic or complexed forms of metal elements. Such UOPs are a potential quality and quantity ICS strategy for rainfall-runoff.

Antigens and granularity of blood monocytes in relation to inflammatory markers and lipids in postmenopausal women.

OBJECTIVES: The menopause is associated with an increase of inflammatory markers (C-reactive protein, fibrinogen), cytokines (INFgamma, TNF, etc.) and blood lipoproteins. In vitro, CRP, LDL and fibrinogen can modulate or potentiate interleukines production by monocytes. The aim of this work was to study, the relationships in vivo between hs-CRP, fibrinogen, lipoproteins and the phenotype of circulating monocytes. METHODS: The monocytes phenotype, in postmenopausal women (n=26) without history of cardiovascular disease, was determined, by flow cytometry, measuring granularity and CD14, HLA-DR and CD62-L antigens expression. Blood monocytes were divided in CD14+dim monocytes (low CD14 expression) and CD14+bright monocytes (high CD14 expression). RESULTS: HLA-DR was negatively correlated with hs-CRP and fibrinogen. The relationships between ApoB, LDL/ApoB ratio and CD14 expression was restricted to the CD14+bright monocytes. Blood lipids, i.e. total cholesterol, LDL-c and ApoB were correlated with the granularity of both subsets. CD14+dim monocytes were characterized by a low granularity and CD62-L expression. CONCLUSIONS: Our data show that fibrinogen and hs-CRP are correlated with a reduced antigen-presenting capacity. Expression of CD14 on CD14+bright monocytes is negatively associated to atherogenic LDL. Blood monocytes granularity was positively correlated with serum lipids indicating that monocytes could uptake modified LDL in circulation and not restricted to subendothelial space.

Effects of sample temperature on red blood cell shape in septic patients.

Several recent in vitro studies have observed that alterations in red blood cell (RBC) rheology depend on sample temperature. This possibility could limit the in vivo validity of the assessment of RBC shape. We investigated the effects of sample temperature on RBC shape estimated by flow cytometry in septic patients compared with those of volunteers. 0.5 ml of blood was placed at 4 degrees C, room temperature (20 degrees C) or at 37 degrees C. RBCs were analyzed at 30 minutes (T30) by flow cytometry and results compared to baseline measures. With the flow cytometry technique, the RBC shape of healthy volunteers shows a bimodal distribution related to the biconcave form. On this histogram, we calculated the second Pearson coefficient of dissymmetry--PCD--representing the asymmetry of this histogram. At baseline, RBC PCD was increased in septic patients representing a more spherical shape compared to volunteers (-0.73+/-0.18 versus -0.95+/-0.05; p=0.007). For both groups, RBC shape estimated by the flow cytometry technique was not modified by the temperature of the sample. We conclude that estimation of RBC shape by flow cytometry is not influenced by the temperature of the sample. The present study validates the flow cytometry technique to assess RBC shape in vitro.

Frequent discordance of the light-chain isotypes expressed by serum monoclonal components and leukaemic B-cells.

In B-cell malignancies, it is generally held that the monoclonal components (MC) are produced by the malignant clones. Genetic relatedness implies the concordant expression of light-chain (LC) isotypes in the MC and at the surface of the malignant lymphocytes. We reviewed a series of 91 B-cell leukaemias, immunophenotyped by flow cytometry in our laboratory. A serum MC had been sought in 75 of these patients, and had been found in 23 (31%). Biclonal serum components were detected in three cases. LC concordance could not be assessed in three cases of surface LC-null lymphocytes. Of the 23 MC studied in 20 patients, light-chains were discordant in 39%, mostly due to kappa MC in lambda leukaemias. The origin of LC discordance remains speculative. It could be due to the emergence of subclones with the same primal VDJ gene rearrangement or, alternatively, to the development of new B-cell clones escaping immune surveillance from deregulated T-cells.

Thiobarbiturate and fructosamine assays: significance and interest of the borohydride blank.

The acute-phase reaction (APR) induces the production by the liver of short-lived glycoproteins. The carbohydrate moiety of these proteins is thought to interfere with the thiobarbiturate (TBA) and nitroblue tetrazolium colorimetric tests which are used for assaying non-enzymatic glycosylation (NEG) of serum proteins. The aim of the present study was to assess the effect of the APR on the specificity of the colorimetric tests in non-diabetic and diabetic subjects. A positive correlation was found between C-reactive protein (CRP), an APR glycoprotein, and non-specific TBA reactivity as determined after borohydride reduction (BH4-resistant TBA, BR-TBA), both in non-diabetics (r = 0.61; P < 0.01) and diabetics (r = 0.68; P < 0.01). The BH4-sensitive specific TBA (SP-TBA) was not influenced by glycoproteins, and its increase in diabetics was correlated with the nitroblue tetrazolium assay (r = 0.89; P < 0.01). An independent effect of diabetes and APR on non-specific TBA was also demonstrated, suggesting an effect of hyperglycaemia on both protein glycation and glycosylation. TBA with borohydride reduction is an attractive tool for the study of complex glycoproteins in diabetes.

Specific effect of age on lectin-induced mitogenesis of lymphocytes from diseased patients.

Using several models of multivariate analysis, it is found that age per se is a specific determinant on the in vitro lymphocyte response to phytohemagglutinin A in a random sample of 30 diseased patients. Depending upon the used model, sex and lymphocyte subsets appear as other significant variables. The multiple regression coefficients reach 0.85. A 2% fall per decade is expected for phytohemagglutinin A responsiveness expressed in 1n cpm.

In vitro effects of flunarizine on human lymphocytes.

Flunarizine, a slow-channel calcium entry blocker used as a vasodilator, interferes in vitro with human lymphocyte functions. It prevents lymphocytes from capping sheep erythrocytes, an effect which is probably due to the disconnection of the membrane from its cytoskeletal control. Flunarizine antagonizes both colchicine and cytochalasin B effects upon capping. Although the mitogen-induced lymphocyte stimulation has been shown to be sensitive to calcium depletion or calcium entry blocking by Verapamil, an enhanced response to phytohaemagglutinin A was observed with flunarizine. This suggests a differential sensitivity of the lymphocytes to calcium-entry blockers.

Effect of dipyridamole upon thymidine incorporation and capping in human lymphocytes.

Dipyridamole is a potent inhibitor of tritiated thymidine incorporation by PHA-stimulated human lymphocytes. This effect is unrelated to the length of culture, to the level of response in untreated cultures, or to the proliferative index. This suggests that dipyridamole principally effects the membrane transport of thymidine. Dipyridamole inhibits sheep-erythrocyte-capping by E-rosettes. This effect cannot be mimicked by theophylline or cyclic nucleotides and cannot be reverted by adenosine. Pharmacological studies with colchicine and cytochalasin B suggest interference with cytoskeletal functions, probably of microtubules. This could be another site of action of dipyridamole beyond phosphodiesterase inhibition and adenosine metabolism.

Scatter photocoagulation for choroidovitreal neovascularization.

Two patients developed choroidovitreal neovascularization subsequent to intense, repeated photocoagulation of a choroidal melanoma. Scatter photocoagulation to the ischemic zone of peripheral retina resulted in prompt, sustained regression of the new vessels. Scatter photocoagulation should be considered as a therapeutic alternative to focal ablative photocoagulation for patients who develop choroidovitreal neovascularization.

A classification and coding system for information retrieval on diagnosis and therapy.

The Wilmer Information System uses an updated hierarchical code derived from the ICD-9 code. The process of coding has been made as simple as possible by the development of Customized Coding Sheets containing the most commonly used diagnoses for each subspecialty. Interactive data entry and retrieval programs have been developed which allow great flexibility in precisely selecting either individual patients or groups of patients for chart review.

The effects of hospital rate-setting programs on volumes of hospital services: a preliminary analysis.

This article describes a preliminary study of the effects of State rate-setting programs on volumes of hospital services, specifically admission rates, occupancy levels, and average lengths of stay. A volume response to rate-setting may be anticipated as a result of program effects on hospital costs or charges as well as on hospitals' behavioral incentives. We analyzed data for samples of hospitals and counties in States with and without rate-setting programs for the 9-year period 1969 to 1978. The results suggested that rate regulation has brought about, in some States, an increase in hospital occupancy by increasing patients' lengths of stay. Few programs have had a measurable effect on the admission rate. Programs that regulate per diem rates seem to produce more consistent and predictable volume effects than those controlling charges. The findings were generally consistent with prior hypotheses and partially account for earlier findings regarding the effects of rate-setting programs on hospital costs.

Diagnostic vitrectomy in metastatic breast carcinoma in the vitreous.

Pars plana vitrectomy was employed to establish the diagnosis of intraocular carcinoma in a 72-year-old woman with a history of breast carcinoma and cerebral astrocytoma. Cytologic study of the material obtained from the vitreous cavity established the diagnosis of metastatic breast carcinoma, and this was later confirmed by study of the eyes obtained postmortem. The clinical and cytologic features of the ocular metastasis of breast carcinoma are presented.