Disinfection byproduct precursor dynamics and water treatability during an extreme flooding event in a coastal blackwater river in southeastern United States.

Coastal blackwater rivers, characterized by high concentrations of natural organic matter, are source water for millions of people in the southeastern US. In October 2015, large areas of coastal South Carolina were flooded by Hurricane Joaquin. This so-called "thousand-year" rainfall mobilized and flushed large amounts of terrestrial organic matter and associated pollutants (e.g. mercury) into source water, affecting water quality and safety of municipal water supply. To understand the dynamics of water quality and water treatability during this extreme flood, water samples were collected from Waccamaw River (a typical blackwater river in the southeastern US) during rising limb, peak discharge, falling limb, and base flow. Despite decreasing water flow after peak discharge, dissolved organic carbon (DOC) levels (increased by up to 125%), and formation potentials of trihalomethanes and haloacetic acids (increased by up to 150%) remained high for an extended period of time (>eight weeks after peak discharge), while variation in the N-nitrosodimethylamine (NDMA) FP was negligible. Coagulation with alum and ferric at optimal dosage significantly reduced concentrations of DOC by 51-76%, but up to 10 mg/L of DOC still remained in treated waters. For an extended period of time, elevated levels of THMs (71-448 µg/L) and HAAs (88-406 µg/L) were quantified in laboratory chlorination experiments under uniform formation conditions (UFC), exceeding the United States Environmental Protection Agency's (USEPA) maximum contaminant level of 80 and 60 µg/L, respectively. Results demonstrated that populations in coastal cities are at high risk with disinfection by-products (DBPs) under the changing climate.

Geochemistry and Mineralogy of Western Australian Salt Lake Sediments: Implications for Meridiani Planum on Mars.

UNLABELLED: Hypersaline lakes are characteristic for Western Australia and display a rare combination of geochemical and mineralogical properties that make these lakes potential analogues for past conditions on Mars. In our study, we focused on the geochemistry and mineralogy of Lake Orr and Lake Whurr. While both lakes are poor in organic carbon (<1%), the sediments' pH values differ and range from 3.8 to 4.8 in Lake Orr and from 5.4 to 6.3 in Lake Whurr sediments. Lake Whurr sediments were dominated by orange and red sediment zones in which the main Fe minerals were identified as hematite, goethite, and tentatively jarosite and pyrite. Lake Orr was dominated by brownish and blackish sediments where the main Fe minerals were goethite and another paramagnetic Fe(III)-phase that could not be identified. Furthermore, a likely secondary Fe(II)-phase was observed in Lake Orr sediments. The mineralogy of these two salt lakes in the sampling area is strongly influenced by events such as flooding, evaporation, and desiccation, processes that explain at least to some extent the observed differences between Lake Orr and Lake Whurr. The iron mineralogy of Lake Whurr sediments and the high salinity make this lake a suitable analogue for Meridiani Planum on Mars, and in particular the tentative identification of pyrite in Lake Whurr sediments has implications for the interpretation of the Fe mineralogy of Meridiani Planum sediments. KEY WORDS: Western Australia-Salt lakes-Jarosite-Hematite-Pyrite-Mars analogue. Astrobiology 16, 525-538.

Formation of chloroform and tetrachloroethene by Sinorhizobium meliloti strain 1021.

UNLABELLED: The mechanisms and organisms involved in the natural formation of volatile organohalogen compounds (VOX) are largely unknown. We provide evidence that the common and widespread soil bacterium Sinorhizobium meliloti strain 1021 is capable of producing up to 3338·6 ± 327·8 ng l(-1) headspace volume of chloroform (CHCl3 ) and 807·8 ± 13·5 ng l(-1)  headspace volume of tetrachloroethene (C2 Cl4 ) within 1 h when grown in soil extract medium. Biotic VOX formation has been suggested to be linked to the activity of halogenating enzymes such as haloperoxidases. We tested if the observed VOX formation by S. meliloti can be attributed to one of its chloroperoxidases (Smc01944) that is highly expressed in the presence of H2 O2. However, addition of 10 mmol l(-1) H2 O2 to the S. meliloti cultures decreased VOX formation by 52% for chloroform and 25% for tetrachloroethene, while viable cell numbers decreased by 23%. Interestingly, smc01944 gene expression increased 450-fold. The quantification of extracellular chlorination activity in cell suspension experiments did not provide evidence for a role of S. meliloti chloroperoxidases in the observed VOX formation. This suggests that a momentarily unknown mechanism which requires no H2 O2 might be responsible for the VOX formation by S. meliloti. Regardless of the underlying mechanism our results suggest that the soil bacterium S. meliloti might be an important source of VOX in soils. SIGNIFICANCE AND IMPACT OF THE STUDY: Volatile organohalogen compounds (VOX) strongly influence atmospheric chemistry and Earth's climate. Besides anthropogenic emissions they are naturally produced by either abiotic or biotic pathways in various environments. Particularly in soils, microbial processes drive the natural halogen cycle but the direct link to microbial VOX formation has not been studied in detail yet. In this study we provide evidence that the common and widespread soil bacterium Sinorhizobium meliloti strain 1021 forms chloroform and tetrachloroethene. The potential contribution of S. meliloti to soil VOX release could significantly influence soil and atmospheric chemistry.

[Fractures of the distal radius]. / Frakturen des distalen Radius.

The most prevalent fractures managed by trauma surgeons are those involving the distal radius. The injury occurs in two peaks of prevalence: the first peak around the age of 10 years and the second peak around the age of 60 years. Distal radius fracture management requires sensitive diagnostics and classification. The objectives of treatment are the reconstruction of a pain-free unlimited durable functioning of the wrist and avoidance of typical fracture complications. Non-operative conservative management is generally employed for stable non-displaced fractures of the distal radius with the expectation of a good functional outcome. Unstable comminuted fractures with intra-articular and extra-articular fragment zones are initially set in a closed operation and finally by osteosynthesis. An armament of surgical implants is available for instable fractures requiring fixation. Palmar locked plate osteosynthesis has been established in recent years as the gold standard for operative management of distal radius fractures. Complex Working Group on Osteosynthesis (AO) classification type 3 fractures require extensive preoperative diagnostics to identify and treat typical associated injuries around the wrist.

A male and female gametocyte functional viability assay to identify biologically relevant malaria transmission-blocking drugs.

Malaria elimination will require interventions that prevent parasite transmission from the human host to the mosquito. Experimentally, this is usually determined by the expensive and laborious Plasmodium falciparum standard membrane feeding assay (PfSMFA), which has limited utility for high-throughput drug screening. In response, we developed the P. falciparum dual gamete formation assay (PfDGFA), which faithfully simulates the initial stages of the PfSMFA in vitro. It utilizes a dual readout that individually and simultaneously reports on the functional viability of male and female mature stage V gametocytes. To validate, we screen the Medicines for Malaria Venture (MMV) Malaria Box library with the PfDGFA. Unique to this assay, we find compounds that target male gametocytes only and also compounds with reversible and irreversible activity. Most importantly, we show that compound activity in the PfDGFA accurately predicts activity in PfSMFAs, which validates and supports its adoption into the transmission-stage screening pipeline.

Predominance of biotic over abiotic formation of halogenated hydrocarbons in hypersaline sediments in Western Australia.

Volatile halogenated organic compounds (VOX) contribute to ozone depletion and global warming. There is evidence of natural VOX formation in many environments ranging from forest soils to salt lakes. Laboratory studies have suggested that VOX formation can be chemically stimulated by reactive Fe species while field studies have provided evidence for direct biological (enzymatic) VOX formation. However, the relative contribution of abiotic and biotic processes to global VOX budgets is still unclear. The goals of this study were to quantify VOX release from sediments from a hypersaline lake in Western Australia (Lake Strawbridge) and to distinguish between the relative contributions of biotic and abiotic VOX formation in microbially active and sterilized microcosms. Our experiments demonstrated that the release of organochlorines from Lake Strawbridge sediments was mainly biotic. Among the organochlorines detected were monochlorinated, e.g., chloromethane (CH3Cl), and higher chlorinated VOX compounds such as trichloromethane (CHCl3). Amendment of sediments with either Fe(III) oxyhydroxide (ferrihydrite) or a mixture of lactate/acetate or both ferrihydrite and lactate/acetate did not stimulate VOX formation. This suggests that although microbial Fe(III) reduction took place, there was no stimulation of VOX formation via Fe redox transformations or the formation of reactive Fe species under our experimental conditions.

[Beyond the horizon of health-care delivery - medical marketing]. / Neue Wirklichkeiten - Marketing und Chirurgie.

BACKGROUND: The progress in medical health care and demographic changes cause increasing financial expenses. The rising competitive environment on health-care delivery level calls for economisation and implementation of a professional marketing set-up in order to ensure long-term commercial success. METHODS: The survey is based on a questionnaire-analysis of 100 patients admitted to a trauma department at a university hospital in Germany. Patients were admitted either for emergency treatment or planned surgical procedures. RESULTS: Competence and localisation represent basic criteria determing hospital choice with a varying focus in each collective. Both collectives realise a trend toward economisation, possibly influencing medical care decision-making. Patients admitted for planned surgical treatment are well informed about their disease, treatment options and specialised centres. The main source of information is the internet. Both collectives claim amenities during their in-hospital stay. CONCLUSION: Increasing economisation trends call for a sound and distinct marketing strategy. The marketing has to be focused on the stakeholders needs. Concomitant factors are patient satisfaction, the establishment of cooperation networks and maintenance/improvement of medical health-care quality.

Pertrochanteric fractures: tips and tricks in nail osteosynthesis.

INTRODUCTION: Intramedullary fixation of intertrochanteric fractures has become the standard method of fixation especially in unstable fracture types. Even though there have been developments on implant design and technology, the surgical technique of reduction and implant positioning remains the mandatory factor in treating these fractures successfully. The advantages of nailing in the mainly elderly patients sustaining intertrochanteric femur fractures are a short lever arm and a lateral support in the trochanter supplied by the nail. The disadvantages are that it is often harder to achieve a closed reduction of a displaced fracture and to maintain the reduction with the intramedullary implant. TIPS AND TRICKS: To obtain and maintain anatomic reduction and a secure fracture fixation, the surgical approach and fixation technique is of great importance. It starts with correct patient positioning, fracture reduction (accounting for varus dislocation and dislocation of flexed fragments), choosing the correct nail entry point and perfect lag screw positioning within the head-neck fragment and distal locking. To maintain the reduction achieved intraoperatively, the decision has to be made to use a cerclage wiring or to tolerate fracture gaps in the metaphyseal area. Intraoperative controlled compression of the neck or the subtrochanteric area is of great importance to reduce delayed unions or nonunions. Intramedullary fixation of unstable per-, inter- or subtrochanteric fractures shows biomechanical advantages compared to extramedullry fixation techniques. Even though there have been several amendments and developments of implants, a better implant does not compensate for an inadequate surgical approach or deficient surgical techniques which are paramount for successful treatment. When fixing fractures with intramedullary nailing systems, the surgeon should always try to achieve anatomic reduction and a perfect implant positioning to allow immediate full weight bearing without an increased risk of cut-out, non-union and implant failure.

Pupil evaluation in addition to Glasgow Coma Scale components in prediction of traumatic brain injury and mortality.

BACKGROUND: Early diagnosis and prediction of traumatic brain injury (TBI) is essential for determining treatment strategies and allocating resources. This study evaluated the predictive accuracy of Glasgow Coma Scale (GCS) verbal, motor and eye components alone, or in addition to pupil size and reactivity, for TBI. METHODS: A retrospective cohort analysis of data from 51 425 severely injured patients registered in the Trauma Registry of the German Society for Trauma Surgery from 1993 to 2009 was undertaken. Only directly admitted patients alive on admission and with complete data on GCS, pupil size and pupil reactivity were included. The unadjusted predictive roles of GCS components and pupil parameters, alone or in combination, were modelled using area under the receiver operating characteristic (AUROC) curve analyses and multivariable logistic regression regarding presence of TBI and death. RESULTS: Some 24 115 patients fulfilled the study inclusion criteria. Best accuracy for outcome prediction was found for pupil reactivity (AUROC 0.770, 95 per cent confidence interval 0.761 to 0.779) and GCS motor component (AUROC 0.797, 0.788 to 0.805), with less accuracy for GCS eye and verbal components. The combination of pupil reactivity and GCS motor component (AUROC 0.822, 0.814 to 0.830) outmatched the predictive accuracy of GCS alone (AUROC 0.808, 0.800 to 0.815). Pupil reactivity and size were significantly correlated (r(s) = 0.56, P < 0.001). Patients displaying both unequal pupils and fixed pupils were most likely to have TBI (95.1 per cent of 283 patients). Good outcome (Glasgow Outcome Scale score 4 or more) was documented for only 1929 patients (8.0 per cent) showing fixed and bilateral dilated pupils. CONCLUSION: The best predictive accuracy for presence of TBI was obtained using the GCS components. Pupil reactivity together with the GCS motor component performed best in predicting death.

Management of traumatic spinopelvic dissociations: review of the literature.

PURPOSE: Spinopelvic dissociation is a rare high-energy injury pattern in adults associated with high morbidity and an increased rate of neurological deficits. The purpose of this article is the conception of fracture type-associated treatment recommendations. METHODS: This article is based on our own experience with spinopelvic dissociations and a review of the current literature. RESULTS: Bilateral vertical plus an optional transverse fracture component configures spinopelvic dissociations as "U"- or "H"-shaped, with the result of a spinopelvic dissociation. "Y"-, "T"- or "II"-shaped fractures do not necessarily belong to this entity but can be subsumed to this entity in a wider sense. The surgical treatment of these injuries remains challenging. Initial haemodynamic stabilisation represents the main goal of primary care until definitive treatment can be performed. Anatomical reduction is demanding and even more complex in fracture areas with large comminution. Surgical treatment options depend on the fracture type, including transsacral screws, sacral banding and spinopelvic fixation, plus combinations of these procedures. CONCLUSIONS: Spinopelvic dissociations remain highly complex injuries. "U"- and "H"-shaped fractures usually require triangular fixation, whereas "II"-, "Y"- and "T"-shaped fractures might be sufficiently stabilised with transsacral screws.

Overweight HIV patients with abdominal fat distribution treated with protease inhibitors are at high risk for abnormalities in glucose metabolism - a reason for glycemic control.

BACKGROUND: In HIV patients, disorders in glucose metabolism seem to be side effects of highly active antiretroviral therapy (HAART) which may be favoured by obesity, abdominal fat accumulation and familial disposition for diabetes mellitus (DM). The aim of our study was to identify patients at high risk for abnormalities in glucose metabolism taking into account HAART, familial disposition for DM and anthropometric parameters. METHODS: Plasma glucose, insulin, c-peptide and insulin resistance (homeostasis model assessment, HOMA) were determined in 44 HIV patients [16 without HAART, 19 with protease inhibitors (PI), 9 without PI (non-PI)] and in 11 healthy subjects. Glucose tolerance was determined by standard procedures. Body mass index (BMI), triceps skin fold thickness and waist circumference were measured and the waist-to-hip-ratio was calculated. Familial disposition for DM was assessed by questionnaire. RESULTS: Impaired fasting glucose was observed in 28% of HAART-treated patients (21% with PI, 7% non-PI), in 13% of HAART-naive but none in healthy controls. 58% of PI, 44% of non-PI, 38% of HAART-naive and none of healthy controls had a HOMA-index > 2.5 which indicates insulin resistance. HAART-treated patients had significantly higher fasting glucose levels (PI: 97 +/- 11 mg/dL, p = 0.048; non-PI: 109 +/- 58 mg/dL, p = 0.009) compared to healthy controls (72 +/- 8 mg/dL). HOMA-Index was higher in PI treated patients (3.74 +/- 3.08) than in HIV negative controls (0.95 +/- 0.28, p = 0.018). The duration of HAART (p = 0.045), overweight and familial disposition for DM (p = 0.017) significantly affected fasting glucose among PI users. Waist circumference affected c-peptide (p = 0.046) concentration in these patients. CONCLUSION: HIV patients on long-term PI therapy with overweight and familial disposition for DM are at high risk to develop abnormalities of glucose metabolism. Thus, measurements of HOMA-Index, BMI and waist circumference should be routinely done especially in PI medicated patients.

Comparison of open versus percutaneous pedicle screw insertion in a sheep model.

Minimally invasive surgery has become more and more important for the treatment of traumatic spine fractures. Besides, some clinical studies, objective data regarding the possible lower damage to the surrounding tissue of the spine is still missing. Here we report a sheep model where we compared a percutaneous versus an open approach for dorsal instrumentation with pedicle screws to the spine. Twelve skeletally mature sheep underwent bilateral pedicle screw fixation at the L4-L6 level. Forty-eight pedicle screws were bilaterally inserted into the pedicles and connected with rods using either an open dorsal standard or a percutaneous approach. Operation time, blood flow, compartment pressure, radiation time, loss of blood, laboratory findings and EMG were evaluated to objectify possible advantages for the percutaneous operation technique. Loss of blood and the distribution of CK-MM as a marker for muscle damage were significantly lower in the percutaneous group. However, radiation time was significantly longer in the percutaneous group. Other parameters like compartment pressure, blood flow and also measurement of the EMG at different time points did not reveal significant differences. Based on the results we found in the present study, percutaneous screw insertion can bring moderate advantages but it should be noted that essential functional deficits to the muscle could not be detected.

Factors influencing the quality of life after burst fractures of the thoracolumbar transition.

INTRODUCTION: Dorsal stabilisation has represented the standard procedure for the treatment of burst fractures of the thoracolumbar spine for a long time, but in the last few years the combined dorsoventral stabilisation has gained in significance due to its higher mechanical stability. However, there are no data yet available indicating whether the patients benefit from the combined operation with regard to their postoperative quality of life and what the advantages are in comparison with the dorsal procedures. Therefore, the question was researched in the framework of a matched-pairs analysis of patients suffering from an unstable fracture of the thoracolumbar transition. MATERIALS AND METHODS: From a consecutive series of patients treated in our clinic between 1995 and 2000, 10 patients with combined and 10 patients with a purely dorsal stabilisation were selected and included in the study. Their quality of life was summed up in retrospect with the SF-36 questionnaire. The X-rays were analysed, and the Cobb angle as well as the sagittal index were calculated. Only patients with burst fractures of the thoracolumbar transition without accompanying co-morbidity and neurological deficits were included in the study. Both of the treated groups were matched with regard to sex, age and radiological patterns of injury. RESULTS: Patients who had undergone only a dorsal stabilisation showed a significant loss of correction according to the sagittal index at the time of the examination (0.88+/-0.02 postoperative vs 0.77+/-0.03 at 4 years postoperatively, p=0.01). In the group of patients treated with the combined therapy, there was no statistically relevant loss of correction with regard to the sagittal vertebral profile. The SF-36 questionnaire showed a reduced quality of life in both groups compared with an age-referenced norm population, especially concerning the parameters of bodily health. No statistically relevant difference was observed between the two groups. Further, there was no statistically relevant association between the parameters of the SF-36 and the clinical and radiological data. After performing several regression analyses it could be shown that the patient's mental health is a strong predictor of the postoperative vitality (r=0.803, p<0.01). However, none of the remaining parameters was able to predict the postoperative quality of life. CONCLUSION: The patients in this study showed a reduced quality of life, independent of the method of surgical treatment. Although better radiological results could be seen for the combined procedure, regarding the postoperative quality of life no advantage could be proved compared with the dorsally stabilized patients. Furthermore, there was no relation between the radiological results and the quality of life parameters. Therefore, it can be assumed that the injury itself seems to be the main cause of the decreased quality of life after a burst fracture of the thoracolumbar transition.

Changes in TH1/TH2 immunity after endovascular and conventional infrarenal aortic aneurysm repair: its relevance for clinical practice.

OBJECTIVE: to evaluate local surgical trauma induced by endovascular (TPEG) and conventional infrarenal aortic aneurysm repair (AAA-C), the inflammatory response and changes in cell-mediated and antibody-mediated immunity as illustrated by the type-1/type-2 T-helper (TH1/TH2) cell balance were investigated. DESIGN: prospective study. PATIENTS AND METHODS: sixteen patients were included, eight patients underwent AAA-C and eight TPEG. Venous peripheral blood samples were collected 24h preoperatively and 24, 48, 72h, 5 and 7 days postoperatively. Besides the WBC, intracellular TH1/TH2 cytokines (IFN-gamma/IL-4) and the cell surface markers HLA-DR on monocytes and CD23 on B cells were measured by four colour flow cytometry. RESULTS: statistically significant higher values in the AAA-C group were demonstrated for neutrophiles. The TH1/TH2 immunobalance (expressed by forming the ratio of IFN-(gamma/IL-4 producing T cells as well as by the ratio of HLA-DR(pos) monocytes/CD23(pos) B-cells) showed a significant shift towards TH2 immunity in the AAA-C group whereas TPEG led to a significant lesser shift 24-72h after surgery (p < 0.05). CONCLUSIONS: TPEG leads to a minor distortion of the TH1/TH2 immunobalance. This implies that TPEG is a less stressing procedure, that is especially beneficial in patients whose conditions are considered less suitable for AAA-C due to age and serious comorbidity.

Increased susceptibility to apoptosis in circulating lymphocytes of critically ill patients.

BACKGROUND AND AIMS: Lymphocyte apoptosis may influence immune responsiveness in systemic inflammation. Therefore, we investigated whether early signs of apoptosis (i.e., annexin-V binding and cell shrinkage) in peripheral lymphocytes were different among patients with severe sepsis, critically ill, nonseptic patients after major surgery, and healthy individuals. PATIENTS/METHODS: Ten patients with severe sepsis and ten critically ill, nonseptic patients after major surgery admitted to a surgical intensive care unit in a university hospital were included in the study. In addition, ten healthy blood donors were included for comparison. We investigated early signs of apoptosis using flow cytometric measurement of annexin-V binding to the cell surface and cell shrinkage of peripheral lymphocytes. RESULTS: The percentage of apoptotic lymphocytes determined as annexin-V positive and propidium iodide negative cells was increased in freshly prepared cells of patients with severe sepsis (11.4 +/- 0.5%) and critically ill, nonseptic patients after major surgery (18.5 +/- 2.0%) relative to healthy blood donors (4.4 +/- 0.5%) (P < 0.05). No significant difference between patients with severe sepsis and patients after major surgery were found. Annexin-V binding increased significantly after OKT-3 stimulation of lymphocytes in patients with severe sepsis (34.4 +/- 1.6%), patients after major surgery (33.8 +/- 3.4%), and healthy blood donors (21.1 +/- 2.8%). No significant difference among groups was detected following OKT-3 stimulation. Furthermore, freshly isolated peripheral lymphocytes of patients with severe sepsis and critically ill, nonseptic patients after major surgery revealed a significantly higher proportion of cell shrinkage than in healthy blood donors (55.0 +/- 2.2%, 21.5 +/- 2.4% vs 3.6 +/- 0.7%; P < 0.05). CONCLUSION: Circulating lymphocytes of critically ill patients show a high degree of early signs of cellular apoptosis. This may contribute to hyporesponsiveness of immune cells in systemic inflammation.

Soluble Fas and Fas-ligand in bladder cancer in vitro and in vivo.

Circulating soluble Fas (sFas) and expression of Fas-ligand on cancer cells are mechanisms of immune escape. The aim of the present study was to investigate expression and production of Fas and Fas-ligand on bladder cancer cell lines of different grade as a basic mechanism of their secretion in vivo. sFas and sFas-ligand serum levels of patients with different stage of bladder cancer were examined to determine the possible clinical use of these molecules as tumor markers. Bladder cancer cell lines RT4 (G1), RT112 (G1), T24 (G3) and SUP (G4) were analyzed by flowcytometry for Fas and Fas-ligand expression. To determine if the Fas-ligand gene is transcribed in these bladder cancer cell lines, RT-PCR was performed on mRNA extracted from these cell lines. Production of sFas and sFas-ligand was examined in cell culture supernatants of the cancer cells as well as in the serum of 62 patients with bladder cancer by a specific ELISA test. We demonstrate that Fas is expressed in similar levels on all human bladder carcinoma cell lines. In T24 (G3) and SUP (G4) cell lines we were able to detect the Fas-ligand protein, whereas no Fas-ligand protein could be found in RT4 and RT112 (G1) cells. Fas-ligand mRNA was expressed in all bladder cancer cell lines. Furthermore, all bladder cancer cell lines produce sFas but no sFas-ligand in spite of mRNA expression. The range of sFas levels in the serum of all patients with bladder cancer was large and did not show a correlation to the histopathological stage of bladder cancer. Although there is in vitro evidence that sFas and Fas-ligand play a role in bladder cancer, no correlation between the sFas and s Fas-ligand serum levels and the histopathological stage of bladder cancer could be found. Therefore, serum sFas and sFas-ligand have to date limited clinical relevance.

Bladder cancer cells acquire competent mechanisms to escape Fas-mediated apoptosis and immune surveillance in the course of malignant transformation.

Mechanisms of resistance against Fas-mediated cell killing have been reported in different malignancies. However, the biological response of immune escape mechanisms might depend on malignant transformation of cancer cells. In this study we investigated different mechanisms of immune escape in 2 well-differentiated low-grade (RT4 and RT112) and 2 poorly differentiated high-grade (T24 and TCCSUP) bladder cancer cell lines. Fas, the receptor of Fas-ligand, is expressed and shedded by human transitional bladder carcinoma cell lines RT4, RT112, T24 and TCCSUP. Cytotoxicity and apoptosis assays demonstrate that in spite of the Fas expression, poorly differentiated T24 and TCCSUP cells are insensitive towards either recombinant Fas-ligand or agonistic apoptosis-inducing monoclonal antibody against Fas. In poorly differentiated T24 and TCCSUP cell lines we were able to detect marked Fas-ligand protein by flow cytometry and Western blot analysis. In grade 1 RT4 and RT112 cells only minor expression of Fas-ligand possibly because of proteinase action. Fas-ligand mRNA translation or post-translational processing seems to be regulated differentially in the cancer cell lines depending on malignant transformation. In co-culture experiments we show that poorly differentiated cells can induce apoptosis and cell death in Jurkat cells and activated peripheral blood mononuclear cells. This in vitro study suggests that bladder cancer cells can take advantage of different mechanisms of immune evasion and become more competent in avoiding immune surveillance during transformation to higher-grade malignant disease.

The clinical course of immune thrombocytopenic purpura in children who did not receive intravenous immunoglobulins or sustained prednisone treatment.

OBJECTIVE: To demonstrate the result of watchful waiting without specific therapy in unselected children with acute immune thrombocytopenic purpura (ITP). STUDY DESIGN: Between May 1992 and October 1999, 55 consecutive children (aged 2 months to 16 years; 28 boys and 27 girls) with acute ITP did not receive intravenously administered immune globulin G (IVIG) or sustained prednisone treatment. Patients with extensive mucosal bleeding were given prednisone, 2 mg/kg/d, for 3 days. RESULTS: In 37 of 55 patients the initial platelet count was <10,000/microL. Ten of these patients had active mucosal bleeding. Five additional patients with bleeding had platelet counts between 10,000 and 20,000/microL. Four patients were given a 3-day course of prednisone. Chronic ITP occurred in 7 (13%) of the patients; 29 patients achieved remission within 6 weeks, and 19 patients, between 6 weeks and 6 months. No life-threatening bleeding occurred, and no patient died. CONCLUSION: Most children with severe thrombocytopenia do not have active mucosal bleeding. This management approach, which did not administer specific therapy, avoided side effects, reduced cost, and was effective.

Modulation of cell surface markers on NK-like T lymphocytes by using IL-2, IL-7 or IL-12 in vitro stimulation.

Cytotoxicity and proliferation of NK-like T (CIK) cells are dependent on the continuous presence of exogenous cytokines, but it is not known which cytokine is optimal. Here, we compared the effect of exogenous interleukin 2 (IL-2), interleukin 7 (IL-7) or interleukin 12 (IL-12) on the generation of CIK cells in addition to IL-1, interferon-gamma and anti-CD3 antibodies. Cell surface markers important for cytotoxic activity and adhesion were defined and cytokines leading to their optimal expression were determined. The most important findings were: (a) IL-12 generates the most CD3/CD56-double-positive CIK cells, (b) the expression of LFA-1/CD11a which is important for cytotoxic activity is highest with IL-7, and (c) IL-7 also generates the most CD28-positive cells which may enhance T cell receptor co-stimulation. In summary, essential differences concerning antigen expression were found when generating CIK cells using IL-7 or IL-12 instead of IL-2. In particular, IL-12 may be of interest due to the high expansion of CD56 positive cells in CIK cell cultures and the important role of these cells in mediating cytotoxicity towards malignant tissues.