Reciprocating constructed wetlands for treating industrial, municipal and agricultural wastewater

Scientists at the Tennessee Valley Authority (TVA), and in collaboration with the U.S. Environmental Protection Agency (EPA), are continuing to develop and refine an innovative wastewater treatment system referred to as reciprocating subsurface-flow constructed wetlands. Reciprocation relates to patented improvements in the design and operation of paired subsurface-flow constructed wetlands, such that contiguous cells are filled and drained on a frequent and recurrent basis. This operating technique turns the entire wetland system into a fixed-film biological reactor, in which it is possible to control redox potential in alternating aerobic and anaerobic zones. Reciprocating systems enable manipulation of wastewater treatment functions by controlling such parameters as hydraulic retention time, frequency of reciprocation, reciprocation cycle time, depth of reciprocation, and size and composition of substrate. These improved wetland technologies have been used for treating municipal/domestic wastewater, high strength animal wastewater, and mixed wastewater streams containing acids, recalcitrant compounds, solvents, antifreeze compounds, heavy metals, explosives, and fertilizer nutrients. Results from selected treatability studies and field demonstrations will be summarized with respect to conceptual design and treatment efficacy.

3-[123I]iodo-alpha-methyl-L-tyrosine transport and 4F2 antigen expression in human glioma cells

3[(123)I]iodo-alpha-methyl-L-tyrosine is a tracer of amino acid transport in brain tumors using single-photon emission-computed tomography and predominantly transported by amino acid transport system L. The 4F2 antigen has been identified to be linked to system L-like transport and is assumed to be a part of the transporter protein. We demonstrated that system L-mediated transport of IMT and 4F2 antigen expression are dependent on proliferation rate of human glioma cells and significantly correlated with each other.

Precursor B-cell lymphoblastic lymphoma in childhood and adolescence: clinical features, treatment, and results in trials NHL-BFM 86 and 90

BACKGROUND

Precursor B-cell lymphoblastic lymphoma (PBLL) is a rare subtype of childhood non-Hodgkin lymphoma (NHL). The purpose of our study was to investigate frequency and clinicopathological features of PBLL in children and to test prospectively the efficacy of an ALL-type therapy for treatment of these patients.

PROCEDURE

From October, 1986, to March, 1995, 1,075 patients up to 18 years of age suffering from all kinds of NHL were registered in the two consecutive multicenter studies NHL-BFM 86 and 90. Of these, 27 patients were diagnosed with PBLL. Twenty-one PBLL patients were treated according to a BFM-ALL-type protocol: an eight-drug induction over 9 weeks was followed by an 8-week consolidation including methotrexate 5 g/m(2) x4. Patients in stages I and II continued with maintenance up to a total therapy duration of 24 months, whereas patients in stages III and IV received an additional eight-drug intensification and cranial radiotherapy (12 Gy for prophylaxis) after consolidation. Six PBLL patients were treated according to the BFM-protocol for B-NHL, stratified according to stage and tumor load and consisiting of two to six 5-day courses of chemotherapy.

RESULTS

The median age of the 27 patients with PBLL (18 boys, 9 girls) was 6.2 (range 0.7-15) years. Stages (St. Jude) were: I (n = 3), II (n = 7), III (n = 9), and IV (n = 8). Twenty-one PBLL patients had nodal disease, 6 patients had subcutaneous manifestations, and 8 patients had bone marrow disease (<25% blasts). All patients achieved remission. With a median follow-up time of 4. 25 years, the estimated probability for event-free survival (pEFS) at 10 years for the total group was 0.73 (SE 0.10). Five patients (2, 1, 1, and 1 patients at stages I, II, III, and IV, respectively) relapsed: 2 of 21 patients who were treated according to the ALL strategy and 3 of 6 who were treated according to the B-NHL-protocol.

CONCLUSIONS

PBLL accounts for 2.5% of childhood NHL. An ALL-type therapy strategy appears to be superior to a short-pulse B-NHL protocol.

Transport mechanisms of 3-[123I]iodo-alpha-methyl-L-tyrosine in a human glioma cell line: comparison with [3H]methyl]-L-methionine

The amino acid analog 3-[(123)I]iodo-alpha-methyl-L-tyrosine (IMT) is under clinical evaluation as a SPECT tracer of amino acid transport in brain tumors. This study investigated the carrier systems involved in IMT transport in human glioma cells in comparison with [3H-methyl]-L-methionine (3H-MET).

METHODS

Human glioma cells, type 86HG-39, were cultured and incubated for 1 min at 37 degrees C with IMT and 3H-MET in the lag phase (1.2 d after seeding), exponential growth phase (3 d after seeding), and plateau phase (8 d after seeding). Experiments were performed in the presence and absence of Na+, during inhibition of system L amino acid transport by 2-aminobicyclo[2.2.1 ]heptane-2-carboxylic acid (BCH), and during inhibition of system A amino acid transport by 2-(methylamino)-isobutyric acid (MeAIB).

RESULTS

IMT and 3H-MET uptake decreased by 55%-73% when the cells entered from the exponential growth phase into the plateau phase (P< 0.05; n = 3-11). Inhibition by BCH reduced uptake of IMT in the lag phase, exponential growth phase, and plateau phase by 90%-98% (P < 0.001; n = 3-6) and the uptake of 3H-MET by 73%-83% (P < 0.001; n = 3-11). In a Na+-free medium 3H-MET uptake was reduced by 23%-33% (P < 0.05; n = 3-11), whereas IMT uptake was not significantly different. MeAIB showed no significant effect on IMT or 3H-MET uptake in either phase.

CONCLUSION

Transport of both IMT and 3H-MET depends on the proliferation rate of human glioma cells in vitro and is dominated by BCH-sensitive transport. These data indicate that system L is induced in rapidly proliferating glioma cells and is the main contributor to the uptake of both tracers. 3H-MET transport showed a minor Na+ dependency that was not attributable to system A. The similarity of transport mechanisms of both tracers emphasizes the clinical equivalence of IMT SPECT and (11)C-MET PET for the diagnostic evaluation of gliomas.

Evaluation of a target contouring protocol for 3D conformal radiotherapy in non-small cell lung cancer

BACKGROUND

A protocol for the contouring of target volumes in lung cancer was implemented. Subsequently, a study was performed in order to determine the intra and inter-clinician variations in contoured volumes.

MATERIALS AND METHODS

Six radiation oncologists (RO) contoured the gross tumour volume (GTV) and/or clinical target volume (CTV), and planning target volume (PTV) for three patients with non-small cell lung cancer (NSCLC), on two separate occasions. These were, respectively, a well-circumscribed T1N0M0 lesion, an irregularly shaped T2N0M0 lesion, and a T2N2M0 tumour. Detailed diagnostic radiology reports were provided and contours were entered into a 3D planning system. The target volumes were calculated and beams-eye view (BEV) plots were generated to visualise differences in contouring. A software tool was used to expand the GTV and CTV in three dimensions for an automatically derived PTV.

RESULTS

Significant inter-RO variations in contoured target volumes were observed for all patients, and these were greater than intra-RO differences. The ratio of the largest to smallest contoured volume ranged from 1.6 for the GTV in the T1N0 lesion, to 2.0 for the PTV in the T2N2 lesion. The BEV plots revealed significant inter-RO variations in contouring the mediastinal CTV. The PTV's derived using a 3D margin programme were larger than manually contoured PTV's. These variations did not correlate with the experience of ROs.

CONCLUSIONS

Despite the use of an institutional contouring protocol, significant interclinician variations persist in contouring target volumes in NSCLC. Additional measures to decrease such variations should be incorporated into clinical trials.

Impaired renal function and tumor lysis syndrome in pediatric patients with non-Hodgkin's lymphoma and B-ALL. Observations from the BFM-trials

OBJECTIVE

Tumor lysis syndrome and renal failure remain important complications early in the course of therapy for pediatric Non-Hodgkin's lymphoma (NHL), frequently leading to therapeutic alterations. In the presented series, children with NHL and tumor lysis syndrome are retrospectively analysed regarding clinical features of acute renal failure and its implications on therapy.

PATIENTS AND METHODS

From 4/1990 to 10/1997, 1192 patients diagnosed of any form of NHL have been registered in the NHL-BFM trials. 63 of these patients were reported to have suffered from impaired renal function and/or tumor lysis syndrome before or during initial treatment. Clinical data of these patients were analysed regarding diagnosis, stage, tumor mass, therapy and complications.

RESULTS

62 of 63 patients with impaired renal function and/or tumor lysis syndrome were diagnosed of Burkitt's lymphoma or B-ALL; 58 (92%) of these patients had advanced stages of disease and high LDH-levels (> 500 U/l). 43 of 63 patients had already signs of impaired renal function at admission. Hyperuricemia was the commonest cause of impaired renal function. Renal infiltration or enlargement was observed in 27 of 63 patients. 6 patients were diagnosed of urinary tract obstruction. 25 patients required hemodialysis. Despite improved renal function before administration of MTX, 21 of 63 patients suffered from protracted MTX-elimination during the first course of therapy. 7 of 63 patients (11%) with tumor lysis syndrome died of sepsis after the first course of therapy, another two patients died within 48 hours of therapy due to electrolyte imbalances.

CONCLUSIONS

In pediatric NHL-patients, Burkitt's lymphoma and B-ALL appear to be the commonest cause of metabolic complications early in chemotherapy. Patients with advanced stages and large tumor mass are at high risk for renal failure. Impaired renal function predisposes patients to further complications and toxic death. Prophylactic use of urate-oxidase in all patients with advanced stage NHL might limit the incidence of tumor lysis syndrome. Prospective studies on renal function prior to and during therapy are required in order to develop a clinical profile reliably detecting patients at risk for developing renal failure and subsequent complications.

Outcome and acute care hospital costs after warm water near drowning in children

OBJECTIVE

Predictive efforts using individual factors or scoring systems do not adequately identify all intact survivors, and therefore all drowning victims are aggressively resuscitated in most emergency departments. More reliable outcome prediction is needed to guide early treatment decisions.

METHODS

The charts of 274 near drowning patients admitted to Loma Linda University Children's Hospital were retrospectively reviewed. Patient outcome was categorized into good (near normal function), and poor (vegetative or dead) categories. Discriminant analysis was used to identify combinations of variables most able to predict outcome and a clinical classification system was constructed. The acute care hospital costs for each group were compared.

RESULTS

Discriminant analysis classification achieved 95% accuracy, predicting death in 6 intact survivors. No combination of variables could accurately separate all intact survivors from the vegetative and dead groups. The clinical classification method achieved 93% overall accuracy, predicting death in 5 intact survivors. Of patients predicted to have a poor outcome, 5 (6.3%) survived intact. Children may experience an unpredictable, prolonged vegetative state followed by full recovery. Vegetative patients are the most expensive to care for (consuming 53% of total costs) while intact survivors are the least expensive. The majority of costs were spent on patients with poor outcome.

CONCLUSIONS

Individual outcome cannot be reliably predicted in the emergency department; therefore, aggressive resuscitation of near drowning victims should be performed. Decisions to subsequently withdraw life support should be made based on integration of likelihood of survival, high (but not absolute) certainty, and parental/societal issues. The vegetative patients are the most expensive to care for, while intact survivors are least expensive. Reduction of expenditures on patients likely to have vegetative or dead outcome would result in substantial savings, but loss of normal survivors.

Duraflo II coating of cardiopulmonary bypass circuits reduces complement activation, but does not affect the release of granulocyte enzymes : a European multicentre study

OBJECTIVE

This study was carried out to: (a) compare complement and granulocyte activation during cardiac operations in patients operated with cardiopulmonary bypass coated with heparin by the Duraflo II method, with activation in patients operated with uncoated circuits; and (b) relate complement, and granulocyte activation to selected adverse effects.

METHODS

In a multicentre study among Rikshospitalet, Ullevaal Hospital in Norway and Uppsala University Hospital in Sweden, plasma concentrations of the complement activation products C4b/iC4b/C4c (C4bc), C3b/iC3b/C3c (C3bc), the terminal SC5b-9 complement complex (TCC), and the granulocyte proteins myeloperoxidase and lactoferrin were assessed in two groups of patients undergoing aortocoronary bypass. Seventy-six patients underwent surgery operated with circuits coated by the Duraflo II heparin coating and 75 uncoated circuits. The same amount of systemic heparin was administered to all patients.

RESULTS

In both groups a significant increase in C4bc was first seen by the end of operation, from 86.7 +/- 12.5 to 273.0 +/- 277.4 nM in controls and from 86.9 +/- 18.5 to 320.2 +/- 190.5 nM in the control group, confirming previous documentation that the classical pathway is not activated during CPB, but as a consequence of protamin administration. The formation of C4bc did not differ significantly between the two groups. In the uncoated group the C3bc concentration increased from 124.0 +/- 15.3 to a maximum of 1176.1 +/- 64.7 nM (P < 0.01) and in the coated group it increased from 129.8 +/- 16.1 to a maximum of 1019.4 +/- 54.9 nM (P < 0.01) during CPB. Summary values but not peak values differed significantly between the groups. In the uncoated group the TCC concentration increased from 0.52 +/- 0.03 to a maximum value of 8.09 +/- 0.57 AU/ml (P < 0.01) while in the coated group the TCC concentration increased from a baseline of 0.53 +/- 0.03 to a peak value of 5.2 +/- 0.24 AU/ml (P <0.01). The difference between the peak values was statistically significant (P = 0.00002). In both groups a significant increase in myeloperoxidase and lactoferrin release was observed by the end of operation. There was no difference in myeloperoxidase or lactoferrin release between the two groups. TCC levels were compared to the occurrence of perioperative infarction, development of lung or renal failure, postoperative bleeding, time on ventilator and days in hospital. Three patients developed perioperative infarction; the peak levels of TCC were significantly higher in these patients than in the 148 patients that did not develop infarction. The reduction in TCC formation in the heparin-coated group was not associated with differences in any of the other clinical parameters. Few adverse effects occurred in the study. The peak values of C3bc were higher in the patients needing inotropic support that in those who did not, the relevance of this finding remains uncertain.

CONCLUSION

It is concluded that the Duraflo II heparin coating reduces complement activation, particularly TCC formation, during CPB, but not the release of specific neutrophil granule enzymes. No certain correlation was established between complement and granulocyte activation and clinical outcome.

Clinical outcome after coronary surgery with heparin-coated extracorporeal circuits for cardiopulmonary bypass

In this prospective randomized trial, we studied whether heparin-coated extracorporeal circuits (ECC), known to reduce complement activation, could improve the clinical outcome of 200 patients undergoing coronary artery surgery. Patients have been divided into two groups (heparin-coated ECC and uncoated ECC groups) which were similar in terms of age, gender, left ventricle function, preoperative aspirin use and consequent intraoperative aprotinin use, number of grafts, duration of aortic cross-clamping and cardiopulmonary bypass. Univariate analysis showed that heparin coating did not reduce significantly postoperative bleeding (640 +/- 311 versus 682 +/- 342 ml with uncoated ECC) nor the need for transfusion (19% of patients versus 25% with uncoated ECC). Adverse events, including all mortality and morbidity noticed during the five first postoperative days, occurred in 20 patients of the uncoated ECC group and in eight patients of the heparin-coated ECC group (p = 0.013). The most frequent complications were supraventricular arrhythmias that occurred in 13 patients of the uncoated ECC group and in four patients of the heparin-coated ECC group (p = 0.02). Multivariate analysis by stepwise logistic regression showed that only heparin coating of the ECC was shown as a significant predictive factor of adverse events reduction (p = 0.01; odds ratio = 0.34). These data suggest that heparin coating reduced postoperative complications in patients undergoing coronary artery surgery.

Ethanol transport in Zymomonas mobilis measured by using in vivo nuclear magnetic resonance spin transfer

For the first time, unidirectional rate constants of ethanol diffusion through the lipid membrane of a microorganism, the bacterium Zymomonas mobilis, were determined, thus replacing indirect inferences with direct kinetic data. The rate constants k1 (in to out) were 6.8 +/- 0.4s(-1) at 29 degrees C and 2.7 +/- 0.3s(-1) at 20 degrees C. They were determined by using 1H selective nuclear magnetic resonance spin magnetization transfer. The measurements were done on l-ml cell suspensions. No addition of radiotracers, withdrawing of aliquots, physical separation methods, or chemical manipulations were required. Until now, the rate constants of ethanol transport in microorganisms have been unknown because ethanol diffuses through the cytoplasmic membrane too quickly for radiolabel approaches. Net velocities of ethanol exchange were calculated from unidirectional rate constants and cytoplasmic volume, which was also determined with the same nuclear magnetic resonance experiments. The results (i) confirmed that ethanol would not be rate limiting during the conversion of glucose by Z. mobilis and (ii) indicated that ethanol can serve as an in vivo marker of cytoplasmic volume changes. This was verified by monitoring for the first time the changes of both cytoplasmic volume and extracytoplasmic and cytoplasmic concentrations of alpha and beta anomers of D-glucose in cell suspensions of a microorganism. These findings may open up new possibilities for kinetic studies of ethanol and sugar transport in Z. mobilis and other organisms.

Endosonography of gastroesophageal varices: evaluation and follow-up of 76 cases

Endosonography was performed in 76 patients who had endoscopically detected gastroesophageal varices or questionable submucosal lesions, or who were being evaluated for pancreatic carcinoma or pancreatitis. The result were compared with surgery or autopsy results. The patients were divided retrospectively into four groups. Group 1 consisted of 6 patients who underwent surgery or autopsy. Five esophageal varices and 1 fundic varix were diagnosed with endosonography and confirmed histologically. Group 2 consisted of 29 patients undergoing sclerotherapy. Intramural thickening of the esophagus and extramural collaterals were found in 20 of 22 patients, respectively. Endoscopy revealed fibrosis in 10 patients. Group 3 consisted of 16 patients evaluated for pancreatic disease. Fifteen fundic varices, 6 cardiac varices, and 5 extramural collateral veins were found by EUS. Group 4 consisted of 16 patients with questionable submucosal lesions and 9 patients with lesions recognized endoscopically as varices. EUS found varices in all 25 patients. In conclusion, EUS is an important procedure in the diagnosis and follow-up of gastroesophageal varices, and in the identification of questionable abnormalities found endoscopically. The effect of sclerotherapy can be demonstrated as mural thickening with disappearance of submucosal varices.

The influence of image resolution on the positron emission tomographic measurement of caudate glucose consumption

The aim of this study was to investigate the influence of image resolution on (a) relative and absolute values of caudate glucose consumption (rCMRGlc) determined by positron emission tomography (PET), and (b) the detection of significant differences in these metabolic values between groups of subjects. For this purpose, raw data of cerebral accumulation of fluorine-18 fluorodeoxyglucose (FDG) obtained in 11 normal subjects and in nine patients with unilateral thalamic infarction were reconstructed using filtered backprojection with four different cut-off frequencies (CFs), yielding images with a transaxial resolution of 5.7, 7.1, 8.9 and 11 mm (full-width at half-maximum; FWHM). Absolute values of caudate rCMRGlc decreased significantly by more than 30% over the range of image resolutions studied. Bilateral ratios of caudate rCMRGlc were insensitive to variations in image resolution. Levels of significance assessing the differences in mean metabolic values between patients and controls were all below 0.01. They were, however, slightly better at image resolutions of 7.1 and 8.9 mm than at a resolution of 5.7 mm. These data indicate (a) that relative values of rCMRGlc are better suited to compare quantitative results from different PET cameras than are absolute values, and (b) that the CF used for the filtered back-projection exerts a small but not negligible influence on levels of significance assessing differences in metabolic values between groups of subjects.

Fetal antigen 1 (FA1) in the human pancreas: cell type expression, topological and quantitative variations during development

Monospecific rabbit anti-human fetal antigen 1 (FA1), was used to examine the distribution of FA1 during the development of the human fetal pancreas and liver using an indirect immunoperoxidase technique. FA1 was expressed by 94% of the glandular epithelial cells of the branching ducts in the pancreatic anlage at week 7 of gestation. This pattern changed during the development of the human pancreas, 64% of the glandular cells being FA1 positive at week 17 of gestation, decreasing to 11% in the infant (4 months after birth). In the infant and adults the FA1 expression was restricted to a subpopulation of beta-cells within the islets of Langerhans. Insulin immunoreactive cells were scattered throughout the epithelium of primitive branching pancreatic ducts at week 7 of gestation, well before the formation of islets. From the 7th through to the 17th week of gestation, FA1 was found in the cytoplasm of fetal hepatocytes, whereas no staining was observed in the liver from a 4-month-old infant. No FA1 expression was found in the epithelium of the developing gut. The present findings indicate that the glandular epithelial cells in the developing pancreas may serve as stem cells, which, if appropriately induced, may differentiate into endocrine cells. Fetal antigen 1 (FA1) may take part in or be a result of this differentiation.

Influence of size of regions of interest on PET evaluation of caudate glucose consumption

The aim of this study was to analyze the influence of variations in the size of regions of interest (ROIs) on values of caudate glucose consumption [regional cerebral metabolic rate of glucose (rCMRglc)] assessed by PET. In addition, we tried to establish the influence of ROI size on levels of significance assessing differences in mean caudate glucose consumption between two groups of subjects. For this purpose, rCMRglc was measured using [18F]fluorodeoxyglucose and the PC-4096 PET camera with an in-plane resolution of 7.1 mm in 12 normal subjects and 12 subjects with early Huntington disease. Caudate rCMRglc was histographically determined using 10 different ROI widths ranging from 2 mm, corresponding to the peak value of caudate rCM-Rglc, to 20 mm. The increase in ROI width from 2 to 20 mm led to a significant decrease of caudate rCMRglc by approximately 66% in the normal subjects and in the patients. The Student t value assessing the differences in mean caudate rCMRglc between the two groups decreased gradually from 5.61 for an ROI width of 2 mm to 3.78 for an ROI width of 20 mm. This corresponds to a worsening of the level of significance from 10(-5) to 10(-3), i.e., by a factor of 100. These data show that (given the resolution of presently used PET cameras) the selection of peak values of caudate rCMRglc is the best way to discriminate between groups of subjects supposed to differ with respect to caudate rCMRglc.

Defective biliary excretion of epinephrine metabolites in mutant (TR-) rats: relation to the pathogenesis of black liver in the Dubin-Johnson syndrome and Corriedale sheep with an analogous excretory defect

Dubin-Johnson patients, mutant Corriedale sheep and TR- and EHBR mutant rats have recessively inherited defective bile canalicular secretion of many nonbile acid organic anions. The human and ovine mutants have black livers and lysosomal pigment accumulation. The livers in TR- and EHBR mutant rats are not black, and sparse lysosomal pigment accumulation is seen. Previously, we postulated that the unidentified pigment in the Dubin-Johnson syndrome results from the accumulation of tyrosine, phenylalanine and tryptophan metabolites, such as metanephrine, which are normally secreted in bile as organic anions. We tested this hypothesis in TR- rats. 3H-epinephrine was injected intravenously; control rats secreted 2.80% +/- 0.52% of the injected dose in bile as compared with 0.19% +/- 0.07% in TR- rats. From 82% to 90% of biliary radioactivity was due to polar conjugates in control rats and mutant rats. TR- rats retained more of the injected dose in the liver, particularly in lysosomes, and secreted more in urine than did control rats. After feeding control and TR- rats for 4 mo with a rat chow diet supplemented with 4% tyrosine, tryptophan and phenylalanine, the liver did not become grossly black; however, histological and electron microscopic study revealed dense lysosomal pigment accumulation in TR- rats. Intraportal injection of metanephrine resulted in the appearance of black liver in TR- rats that persisted for at least 2 hr and was not associated with pigment accumulation by light or electron microscopic examination.(ABSTRACT TRUNCATED AT 250 WORDS)