X-Ray Absorption Spectrum of the N_{2}^{+} Molecular Ion

The x-ray absorption spectrum of N_{2}^{+} in the K-edge region has been measured by irradiation of ions stored in a cryogenic radio frequency ion trap with synchrotron radiation. We interpret the experimental results with the help of restricted active space multiconfiguration theory. Spectroscopic constants of the 1σ_{u}^{-1} ^{2}Σ_{u}^{+} state, and the two 1σ_{u}^{-1}3σ_{g}^{-1}1π_{g} ^{2}Π_{u} states are determined from the measurements. The charge of the ground state together with spin coupling involving several open shells give rise to double excitations and configuration mixing, and a complete breakdown of the orbital picture for higher lying core-excited states.

Functional Interrogation and Mining of Natively-Paired Human VH:VL Antibody Repertoires

Next-Generation sequencing has become an essential tool in the analysis of antibody responses in the settings of health, vaccination, and disease. However, immune receptors comprise two chains encoded by separate mRNA strands, and conventional NextGen sequencing fails to identify the native pairings encoded by individual lymphocytes. To overcome this limitation we have applied recent technical advances in high-throughput sequencing and functional analysis of complete antibodies (i.e., paired heavy and light chain sequencing) to generate a comprehensive understanding of the antibody response to vaccination and natural infection. Here we present a new technology to screen natively-paired human antibody repertoires from millions of B cells. Libraries of natively-paired variable region heavy and light (VH:VL) amplicons were expressed in a yeast display platform that was optimized for human Fab surface expression, and the resulting libraries were interrogated for binding to viral vaccine antigens via FACS paired with next generation sequencing. Using our method we identified HIV-1 broadly neutralizing antibodies (bNAbs) from an HIV-1 slow progressor and high-affinity neutralizing antibodies responding to an Ebola virus glycoprotein vaccination. These next-generation approaches are providing detailed molecular feedback on immune receptor responses and are informing the design and discovery of new vaccines and therapeutics.

Synthesis of the rare disaccharide nigerose by structure-based design of a phosphorylase mutant with altered regioselectivity

In the absence of the natural acceptor inorganic phosphate wild-type sucrose phosphorylase from Bifidobacterium adolescentis (BaSP) produces maltose (4-O-α-d-glucopyranosyl-d-glucose) and kojibiose (2-O-α-d-glucopyranosyl-d-glucose) as sole transfer products. A Q345F exchange switches the enzyme's regioselectivity from 2 to 3 exclusively, yielding the rare sugar nigerose (3-O-α-d-glucopyranosyl-d-glucose, sakebiose).

Comparison of sampling methods for the assessment of indoor microbial exposure

Indoor microbial exposure has been related to allergy and respiratory disorders. However, the lack of standardized sampling methodology is problematic when investigating dose-response relationships between exposure and health effects. In this study, different sampling methods were compared regarding their assessment of microbial exposures, including culturable fungi and bacteria, endotoxin, as well as the total inflammatory potential (TIP) of dust samples from Danish homes. The Gesamtstaubprobenahme (GSP) filter sampler and BioSampler were used for sampling of airborne dust, whereas the dust fall collector (DFC), the electrostatic dust fall collector (EDC), and vacuum cleaner were used for sampling of settled dust. The GSP assessed significantly higher microbial levels than the BioSampler, yet measurements from both samplers correlated significantly. Considerably higher levels of fungi, endotoxin, and TIP were found in the EDC compared with the DFC, and regarding fungi, the EDC correlated more strongly and significantly with vacuumed dust than the DFC. Fungi in EDC and vacuum dust correlated most strongly with airborne dust, and in particular, the measurements from the EDC associated well with those from GSP. Settled dust from the EDC was most representative of airborne dust and may thus be considered as a surrogate for the assessment of indoor airborne microbial exposure.

PRACTICAL IMPLICATIONS

Significant discrepancies between sampling methods regarding indoor microbial exposures have been revealed. This study thus facilitates comparison between methods and may therefore be used as a frame of reference when studying the literature or when conducting further studies on indoor microbial exposure. Results also imply that the relatively simple EDC method for the collection of settled dust may be used as an alternative to otherwise tedious and time-consuming airborne dust sampling.

CD20-targeted measles virus shows high oncolytic specificity in clinical samples from lymphoma patients independent of prior rituximab therapy

New therapeutic modalities for B-cell non-Hodgkin's lymphomas (B-NHL) are needed, especially for relapsing and aggressive subtypes. Toward this end, we previously generated a fully CD20-targeted and armed measles virus, and tested its efficacy in a xenograft model of mantle cell lymphoma (MCL). Here, we quantify its spread in peripheral blood mononuclear cells and/or tissue of patients with different histological subtypes of B-NHL, including splenic marginal zone lymphoma (SMZL). CD20-targeted MV efficiently infects lymphoma cells from SMZL and MCL while sparing most cells in the CD20-negative population, in contrast to the parental vaccine-lineage MV, which infects CD20-positive and CD20-negative cells equally. Rituximab therapy (4-8 months before relapse) did not interfere with the infectivity and specificity of MV(green)H(blind)antiCD20 in patient lymphoma samples. Thus, CD20-targeted oncolytic virotherapy is likely to be effective after previous antiCD20 therapy.

Sorafenib, a dual Raf kinase/vascular endothelial growth factor receptor inhibitor has significant anti-myeloma activity and synergizes with common anti-myeloma drugs

Multiple myeloma is characterized by increased bone marrow neovascularization driven in part by vascular endothelial growth factor (VEGF). In addition, the Ras/Raf/MEK/ERK pathway is critical for the proliferation of myeloma cells and is often upregulated. Sorafenib (Nexavar) is a novel multi-kinase inhibitor that acts predominantly through inhibition of Raf-kinase and VEGF receptor 2, offering the potential for targeting two important aspects of disease biology. In in vitro studies, sorafenib-induced cytotoxicity in MM cell lines as well as freshly isolated patient myeloma cells. It retained its activity against MM cells in co-culture with stromal cells or with interleukin-6, VEGF or IGF; conditions mimicking tumor microenvironment. Examination of cellular signaling pathways showed downregulation of Mcl1 as well as decreased phosphorylation of the STAT3 and MEK/ERK, as potential mechanisms of its anti-tumor effect. Sorafenib induces reciprocal upregulation of Akt phosphorylation; and simultaneous inhibition of downstream mTOR with rapamycin leads to synergistic effects. Sorafenib also synergizes with drugs such as proteasome inhibitors and steroids. In a human in vitro angiogenesis assay, sorafenib showed potent anti-angiogenic activity. Sorafenib, through multiple mechanisms exerts potent anti-myeloma activity and these results favor further clinical evaluation and development of novel sorafenib combinations.

Expression of VEGF and its receptors by myeloma cells

Angiogenesis or new vessel formation is an essential component in the growth and progression of neoplasms and there is growing evidence of its importance in hematological malignancies including multiple myeloma (MM). Vascular endothelial growth factor (VEGF) is believed to play a role in tumor angiogenesis. We studied the expression of VEGF and its receptors (VEGFR1 or Flt-1 and VEGFR2 or Flk-1/KDR) by myeloma cell lines and plasma cells isolated from patients, using different methods. VEGF expression by the plasma cells was demonstrated by immunohistochemistry in 18 of 20 patients with MM. Enzyme-linked immunosorbent assay demonstrated VEGF secretion in all six different myeloma cell lines studied. Five patient marrow samples and seven different myeloma cell lines were then studied for VEGF mRNA expression by reverse-transcriptase polymerase chain reaction (RT-PCR), which was positive in all. We further evaluated the expression of both VEGFR1 and VEGFR2 in different myeloma cell lines and five sorted myeloma bone marrow samples by RT-PCR. All the myeloma cell lines expressed VEGFR1 and three of the cell lines expressed VEGFR2. VEGFR1 expression was detected in all and VEGFR2 in all but one of the sorted marrow samples. Increased expression of VEGF by the myeloma cells taken in the context of the suspected prognostic value of marrow angiogenesis suggests a pathogenetic role for this cytokine and presence of its receptors on myeloma cells points toward an autocrine mechanism. Demonstration of the presence of VEGFR2 in our study provides a potential biological explanation for the preclinical activity observed with VEGFR2 inhibitors.

Measurements of harmonic wake fields excited by rough surfaces

An experiment has been carried out at the TESLA Test Facility linac to investigate the wake fields generated by picosecond electron bunches in narrow beam pipes with an artificially roughened inner surface. The energy structure imposed on the bunches by the wake fields has been analyzed with a magnetic spectrometer. Strong harmonic-wake-field effects are observed as expected from simulations in which the rough surface is modeled by a dielectric layer.

Impact of community-based education on health care evaluation in patients with acute chest pain syndromes: the Wabasha Heart Attack Team (WHAT) project

BACKGROUND

Community education programmes focused on raising public awareness of the symptomatology of acute coronary syndromes have had mixed results.

OBJECTIVES

The Wabasha Heart Attack Team project, a unique multidisciplinary public education effort in Minnesota, sought to educate area citizens about signs and symptoms of acute myocardial infarction (MI).

METHODS

After an intensive 1-month education period, we compared presentations for emergency evaluation of chest pain during the study period with baseline data from the same seasonal period of the preceding year.

RESULTS

Visits to the Emergency Room for symptomatic heart disease increased significantly during the study period (56 patients versus 46 patients during the baseline period), as did the percentage of patients presenting with acute MI (18% versus 12%, P < 0.05). Use of emergency medical services for pre-hospital evaluation was significantly increased (41% versus 27%, P < 0.05).

CONCLUSION

A community education campaign can significantly increase use of pre-hospital emergency medical service resources and may increase the number of patients presenting with acute chest pain symptoms, including MI.

Oxidation in fish oil enriched mayonnaise: ascorbic acid and low pH increase oxidative deterioration

The effect of ascorbic acid (0-4000 ppm) and pH (3.8-6.2) on oxidation and levels of iron and copper in various fractions of mayonnaise enriched with 16% fish oil was investigated. Ascorbic acid induced release of iron from the assumed oil-water interface into the aqueous phase at all pH levels, but this effect of ascorbic acid was strongest at low pH (pH 3.8-4.2). Ascorbic acid generally promoted formation of volatile oxidation compounds and reduced the peroxide value in mayonnaises. Peroxide values and total volatiles generally increased with decreasing pH values, suggesting that low pH promoted oxidation. It is proposed that iron bridges between the egg yolk proteins low-density lipoproteins, lipovitellin, and phosvitin at the oil-water interface are broken at low pH values, whereby iron ions become accessible as oxidation initiators. In the presence of ascorbic acid, oxidation is further enhanced due to the reduction of Fe(3+) to Fe(2+) that rapidly catalyzes lipid oxidation via lipid hydroperoxide decomposition at the oil-water interface in mayonnaise.

First observation of self-amplified spontaneous emission in a free-electron laser at 109 nm wavelength

We present the first observation of self-amplified spontaneous emission (SASE) in a free-electron laser (FEL) in the vacuum ultraviolet regime at 109 nm wavelength (11 eV). The observed free-electron laser gain (approximately 3000) and the radiation characteristics, such as dependency on bunch charge, angular distribution, spectral width, and intensity fluctuations, are all consistent with the present models for SASE FELs.

Induction of apoptosis in malignant B cells by phenylbutyrate or phenylacetate in combination with chemotherapeutic agents

Phenylacetate (PA) and phenylbutyrate (PB) are aromatic fatty acids that are presently undergoing evaluation as potential antineoplastic agents. In vitro, PA and PB cause differentiation or growth inhibition of malignant cells. Clinical trials of these drugs as single agents indicate that they are not myelosuppressive; therefore, combinations with other chemotherapy agents may be possible. The goals of this study were to determine whether PA and PB (a) are cytotoxic to malignant B cells from patients with non-Hodgkin's lymphoma and B-cell chronic lymphocytic leukemia and (b) exhibit additive or synergistic induction of apoptosis when administered to myeloma cell lines in combination with conventional drugs. In the clinical specimens, cytotoxicity was measured by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, and percent apoptosis was measured using 7-aminoactinomycin D and flow cytometry. Viability was decreased by > 50% in 7% (1/15) of non-Hodgkin's lymphoma samples treated with 5 mM PA, 27% treated with 1 mM PB, and 60% treated with 2 mM PB. Likewise, viability was decreased by > 50% in 44% (4/9) of chronic lymphocytic leukemia samples treated with 5 mM PA, 67% treated with 1 mM PB, and 100% treated with 2 mM PB. Studies in the myeloma cell lines demonstrated that PB treatment induced activation of caspases 3, 7, and 9 accompanied by cleavage of their substrates and internucleosomal DNA degradation. Combinations of PA or PB with conventional drugs (cytarabine, topotecan, doxorubicin, etoposide, chlorambucil, melphalan, fludarabine, carboplatin, and cisplatin) were examined for synergism (combination index < 1 in median effect analysis) in inducing apoptosis of both the MY5 and 8226 human myeloma cell lines. At concentrations that killed > 50% of cells, most combinations were additive; however, PB was synergistic with cytarabine, etoposide, and topotecan, with the combination index < 1 at each of the 50, 75, and 95% apoptosis levels. These observations indicate that PA and PB can induce apoptosis in malignant B cells and enhance the cytotoxicity of agents used in the treatment of these malignancies.

[Detection and prevalence of verotoxin-producing Escherichia coli (VTEC) in raw sausage]

We investigated 158 samples of shortly ripened raw sausages bought in supermarkets of Dessau within 4 month. In 14 (8.8%) samples Verotoxin-producing E. coli were detected. 13 VT-positive samples were found in the group of easily spread raw sausages. The 14 isolates belonged to 6 different O-serotypes. 4 VT1-, 8 VT2- and 2 VT1/VT2-producers were found. 4 isolates belonged to serogroups which were already described in WHO tables and associated with EHEC infections in human beings. One strain of serogroup O22: H8, isolated from a "Teewurst", possessed the complete virulence gene combination of EHEC (eae, hlyA, stx). The detection procedure, already successfully used for detection and isolation of VTEC from raw milk, soft cheese and raw minced beef showed a sensitivity of approximately 10 CfU/25 g of raw sausages. It has to be considered that VTEC are frequently (8.8%) present in shortly ripened raw sausages. The group of easily spread raw sausages has a higher VTEC-contamination rate than firm raw sausages. Raw sausages, especially easy to spread types, belong to the risk foods for EHEC-infections in human beings.

Measurement of apoptosis and proliferation of bone marrow plasma cells in patients with plasma cell proliferative disorders

The proliferative rate of malignant plasma cells, as measured by the plasma cell labelling index (PCLI), is an important prognostic factor in multiple myeloma (MM); however, the PCLI alone is probably Inadequate to describe tumour growth because it ignores the idea that myeloma cells may have a reduced rate of apoptosis. The aims of this study were to develop a flow cytometric method to measure the apoptosis index of fresh marrow plasma cells and develop a plasma cell growth index (PCGI) that related both proliferation and apoptosis to disease activity. Marrow aspirates were obtained from 91 patients with plasma cell disorders and the plasma cells in apoptosis were identified by either 7-amino actinomycin-D (7-AAD) or annexin V-FITC three-colour flow cytometry. The median plasma cell apoptotic index (PCAI) for patients with monoclonal gammopathy of undetermined significance (MGUS), smouldering or indolent myeloma (SMM/IMM), and new multiple myeloma (MM) was 5.2, 3.4 and 2.4, respectively (P=0.03, MGUS v MM). The median PCLI for these same patient groups was 0.0, 0.2 and 0.6, respectively (P<0.001, MGUS v MM). The paired PCLI and PCAI for each sample were used to derive the PCGI=2 + [PCLI-(O.1)(PCAI)]. The median PCGI for patients with inactive disease (MGUS, SMM/IMM or amyloidosis) was 1.8 compared to 2.4 for those with active disease (new or relapsed MM) (P<0.001). These results suggest that a decrease in the PCAI may be a factor in the progression from MGUS to SMM to overt MM.

Regional variations in endothelin-1 and its receptor subtypes in human coronary vasculature: pathophysiological implications in coronary disease

Endothelin-1 is a potent vasoconstrictor peptide and mitogen for vascular smooth muscle cells. Increased plasma or tissue levels of endothelin-1 have been described after myocardial infarction and in atherosclerosis, suggesting that this peptide may play a pathophysiological role in various coronary syndromes. Here, we have studied regional variations in ET-1 and its receptors in control and atherosclerotic human coronary vasculature using standard immunohistochemistry and in vitro autoradiography. ET-1 immunoreactivity was associated with luminal endothelial cells and smooth muscle cells at regions of atherosclerosis. ET(A) receptors were present on smooth muscle cells of coronary arteries and on cardiac myocytes. Medial ET(B) receptor binding at the proximal region of coronary arteries was weak, but increased significantly towards distal regions of this vessel (p<0.005 in control and p<0.0005 in ischaemic heart disease). Microvascular endothelial cells in the adventitia of coronary arteries, myocardial microvessels and the endocardial endothelium expressed the ET(B) receptor exclusively. The receptor variations revealed in this study provide supporting evidence that ET-1 is associated with (1) vascular smooth muscle and endothelial cell proliferation, including areas of intimal hyperplasia and regions of neovascularization (2) increased ET-1-induced reactivity of distal portions of the human coronary artery, (3) ET-1-mediated constriction of myocardial microvessels. These results provide new insights into different potential roles for this peptide in healthy and diseased human coronary vasculature.

Measurement of the cell proliferation rate of bone marrow erythroid precursors by flow cytometry: initial applications to multiple myeloma

To investigate the pathophysiology of anemia, a two-color flow cytometric method was developed that measures the proliferative rate of the marrow erythroid cells (EPR). The method uses a monoclonal antibody, RC17.2, to identify erythroid precursors and propidium iodide to determine the %S-phase. This technique was then used to test the hypothesis that a decrease in the proliferative rate of the marrow erythroid precursors contributes to the anemia of multiple myeloma. The EPR was determined on the marrow aspirate from 56 patients and the mean EPR was 31.2% (median, 31: range, 14-55). Patients with anemia (n = 36) had a median EPR of 27% compared to 35% for those patients with a normal Hgb (p = < 0.001); however, there was no difference in the % marrow erythroid precursors (p = 0.96) or % marrow plasma cells (p = 0.08) between the two groups. These results suggest that one possible cause for the anemia of myeloma is a decrease in the EPR. This flow cytometric technique may also be useful in studying other anemias.

Endothelin-1 and endothelin receptors in porcine saphenous vein-carotid artery grafts

The regional distribution of endothelin-1 (ET-1) and its receptor subtypes (ETA and ETB) in porcine saphenous vein into carotid artery interposition grafts was studied 1 month after surgery and compared to ungrafted saphenous vein and carotid artery. ET-1 immunoreactivity was identified by immunohistochemistry and ET receptor subtypes were studied using in vitro autoradiography. In vein grafts, there was a higher density of ETA compared to ETB receptor binding in both the tunica media and the neointima. ETA binding to the tunica media of ungrafted saphenous vein was greater than that in the carotid artery or vein grafts, but greater in the vein graft compared to the carotid artery. Immunoreactive ET-1 was located in endothelial cells and throughout the neointima of the vein graft. Dense ETA and ETB binding was also associated with adventitial microvessels in the graft, and ETB binding was also identified to neutrophils, which accumulated at the subendothelium and within the adventitia. ETA receptors may play a role in vein graft thickening at the medial and neointimal vascular smooth-muscle cell level, whereas ETB receptors may play a role in microangiogenesis. The high levels of ETA receptors in the tunica media of ungrafted saphenous vein, relative to the carotid artery and vein graft, may also render this conduit susceptible to neointimal formation. These data indicate that studies of the effect of ET receptor antagonists on the pathobiology of vein graft disease are warranted.

Distribution of endothelin-1 (ET) receptors (ET(A) and ET(B)) and immunoreactive ET-1 in porcine saphenous vein-carotid artery interposition grafts

Proliferation of vascular smooth muscle cells (VSMC) is a principal event in neointima formation in saphenous vein-coronary artery bypass grafts. Since endothelin-1 (ET-1) promotes VSMC replication and ET-1 receptor antagonists inhibit neointima formation in arterial injury models, it is reasonable to propose that ET-1 may be involved in neointima formation in vein grafts. However, it is not known what alterations of ET-1 and its receptors (if any) occur in vein grafts. The objective of this study, therefore, was to investigate the distribution of ET-1 and ET-1 receptor subtypes (ET(A) and ET(B)) in porcine vein grafts. Unilateral interposition saphenous vein grafting was performed by end to end anastomosis after excision of a segment of carotid artery in Landrace pigs. One month after surgery, vein grafts, ungrafted saphenous veins and carotid arteries were excised, ET-1 immunoreactivity identified by immunocytochemistry and ET(A) and ET(B) receptor subtypes studied using autoradiography. In vein grafts, there was a greater density of ET(A) compared to ET(B) receptors in both the tunica media and neointima. ET(A) binding in the tunica media of ungrafted saphenous vein was greater than that in the carotid artery or vein grafts, but greater in the vein graft compared to the carotid artery. Immunoreactive ET-1 was located in endothelial cells and throughout the neointima of the vein graft. Dense ET-1 binding (to both ET(A) and ET(B) receptors) was also associated with microvessels in the adventitia within the graft. In vein grafts, there was strong ET(B) binding to neutrophils which were present in high numbers at the subendothelium and within the adventitia. It is concluded ET(A) receptors may play a role in vein graft thickening at the medial and neointimal VSMC level, whereas ET(B) receptors may play a role in microangiogenesis. The higher levels of ET(A) receptors in the tunica media of ungrafted saphenous vein relative to the carotid artery and vein graft may also render this conduit susceptible to neointima formation. These data indicate that studies on the effect of ET receptor antagonists on the pathobiology of vein graft disease is warranted.

[Detection and occurrence of verotoxin-forming and/or shigatoxin producing Escherichia coli (VTEC and/or STEC) in milk]

Raw milk contaminated with VTEC was described as a source of human EHEC infection. Diagnosis of VTEC from milk is complicated by the low number of VT-positive cells in the total bacterial count, the great variety of serovars with different combinations of virulence markers and the lack of characteristic biochemical properties for the cultural detection of all VTEC. The graduated procedure presented and used for the examination of milk samples is based on VT detection in suitable enrichment cultures and the selective isolation of VTEC by means of VT-specific monoclonal antibodies using the VT-colony immunoblot. This method was used to examine 127 samples of raw milk and 146 samples of certified raw milk (Vorzugsmilch) from 5 different regions in Germany. 3.9% of the raw milk samples and 2.1% of the certified raw milk samples were VTEC-positive. Except for one O157:H- isolate from a raw milk sample, the VTEC found belonged to the group of non-O157 VTEC. They were assigned to 5 different serovars with different combinations of virulence markers. Therefore, raw milk and certified raw milk will continue to present a potential source of EHEC infection. It is recommended to use the procedure presented for the elucidation of the route of infection and for the improvement of detection of VTEC and EHEC-strains in milk in order to obtain comparable data for diagnosis in the official food control laboratories of the federal lands.

Detection of STEC and epidemiological investigations in surrounding of a HUS patient

After occurrence of a case of HUS infection in a 2-year-old infant from a dairy farmer's family living near Oldenburg, investigations were performed in the infant's surrounding in order to elucidate the route of infection. Since hospitalization took place at a late stage, it was not possible to isolate EHEC from the patient's stool samples. However, E. coli O157 antibody determinations in serum were positive. Since STEC of serogroup O157 were found in faeces from the 34 dairy cows of the farm, stool samples were taken from 6 members of the child's family and examined. Non-O157 STEC could be isolated from the stools of 2 family members. Determination of other virulence factors and other characteristics such as serotype, biotype and phage type showed identity of the agent for 3 isolates (2 from animals, 1 from humans). By means of pulsed-field gel electrophoresis of the restricted DNA of the isolates and by means of RAPD-PCR it was not possible to establish any differences in the band patterns. It can be assumed, therefore, that the organisms had been transmitted from animals to humans.

[Present problems in detection of sources of infection and chains of infection with enterohemorrhagic E. coli (EHEC)]

In the context of the detection of the haemolyticuraemic syndrome (HUS) and of enterohaemorrhagic E. coli (EHEC) in 13 persons, 372 faeces samples from 13 herds of cattle in northern Bavaria were examined for the presence of EHEC. 128 (34.4%) of the faeces samples were found to be VT-positive. From 78 of these samples (61%), verotoxin-producing E. coli strains (VTEC) could be isolated. During these examinations, E. coli strains with combinations of markers (VT, eae A, EHEC haemolysin) being typical of EHEC were found in 3 samples from animals belonging to the same herd. In 2 cases, these could be assigned to O157:H-, in one, to O118:H16. It has not been possible to detect possible sources of infection and chains of infection assumed to exist in association with the detection of HUS and EHEC infections in humans because most cases had been diagnosed on the basis of verotoxin detection in stool specimens. Moreover, corresponding isolates for a comparative onward differentiation from verotoxin-producing E. coli isolates from animals were not or could not be made available.

[Verotoxin-producing E. coli (VTEC) in feces from cattle slaughtered in Germany]

In man, EHEC infections may result in severe disease. Cattle and foods derived from this animal species are considered as a source of infection. The presence of VTEC being potential EHEC was studied. For analysis, feces samples were examined which had been taken from 204 heads of cattle slaughtered in various regions of Germany. VTEC could be isolated from 97 animals (47.6%). This indicates a presence of VTEC in slaughtered cattle being 5 times higher than known for Germany so far. The aeaA gene could be demonstrated in a mere 23 out of 667 VTEC isolates. The CVD 419 sequence was present in 55.3% of the VTEC isolates. Ehly was found in 61% of them. Consequently, both markers were unsuitable for the detection of VTEC in faeces samples from cattle and in foods with faecal contamination. The VTEC isolates belonged to 54 different serotypes of E. coli, VTEC 0157 have not been found so far. Some of the VTEC serovars found in this study have already been described as associated with human disease following EHEC infection. The presently available laboratory methods do not permit to exclude a risk for humans from bovine VTEC reliably. For this reason, bovine VTEC should be further on considered as potential EHEC and an infection of humans by such agents be avoided.

Nitric oxide synthase and adenylyl and guanylyl cyclase activity in porcine interposition vein grafts

BACKGROUND

A high proportion of autologous saphenous vein grafts occlude as the result of intimal thickening. Blood vessels synthesize substances that may inhibit such intimal thickening. These include cyclic adenosine monophosphate (cAMP) and cyclic guanosine monophosphate (cGMP), which are stimulated by prostacyclin and nitric oxide, respectively. The prostacyclin-cAMP and nitric oxide-cGMP axes were therefore investigated in porcine vein grafts.

METHODS

Saphenous vein-carotid artery interposition graft procedures were carried out in pigs. One month after the operation, ungrafted saphenous veins, vein grafts, and carotid arteries were excised, the formation of cAMP and cGMP was assessed by radioimmunoassay, and the nitric oxide synthase content was determined by autoradiography.

RESULTS

The formation of cAMP and nitroprusside-stimulated cGMP was significantly diminished in vein grafts compared with ungrafted saphenous veins and carotid arteries. Calimycin-stimulated cGMP synthesis (nitric oxide release dependent) and the endothelial nitric oxide synthase content (autoradiography) were significantly elevated in vein grafts compared with ungrafted saphenous veins but were significantly less than those in carotid arteries.

CONCLUSIONS

Adenylyl and guanylyl cyclase activity are down-regulated in vein grafts, which may contribute to the development of intimal and medial thickening. Nitric oxide release and endothelial nitric oxide synthase content are up-regulated in vein grafts, which is indicative of an adaptation to the arterial conditions of shear stress and pulsatile pressure.

[A method for specific isolation of verotoxin-producing Escherichia coli colonies]

The described colony immunoblot is a special double membrane-agar technology, which permits the specific isolation of VTEC in biological materials decided VT-positive by EIA or PCR. The produced Verotoxin (VT) is detected on the surface of the lower membrane by help of monoclonal antibodies. A direct allocation of the corresponding VT-expressing E. coli-colonies on the upper membrane is possible. So the isolation and further characterisation of potential VTEC is practicable in materials with a high microbial contamination too. This isolation method is available for the examination of VT-positive faeces and foods. In the case of foods it is necessary to work with an enrichment culture.

Prevalence of the fimbrial antigens F18 and K88 and of enterotoxins and verotoxins among Escherichia coli isolated from weaned pigs

Until recently, the fimbrial F18 antigen has been provisionally designated F107, 2134P, or 8813. Using the slide agglutination test, this antigen was shown to be present on 139 of 160 Escherichia coli strains of type O139:K82 and on all of the 146 K88-negative strains of the other pathogenic porcine serotypes. These strains were isolated from weaned pigs which in most cases had died from postweaning colibacillosis. All strains were haemolytic. With only three exceptions, they produced verotoxin and/or enterotoxin. The F18ab variant strongly predominated on the O139:K82 strains and was found on about half of the O138:K81 strains and a few O157 strains, whereas the other strains carried the F18ac variant. In serotypes which can carry either F18 or K88 fimbriae, closer clonal relationships between the strains associated with F18 and those associated with K88 were missing.

bcr/abl expression in 32D cl3(G) cells inhibits apoptosis induced by protein tyrosine kinase inhibitors

Eight protein tyrosine kinase inhibitors with in vitro epidermal growth factor receptor kinase 50% inhibitory concentration values ranging from 0.043 to 22 microM were studied for their ability to inhibit the growth of the murine interleukin-3 (IL-3) dependent myeloid 32D cl3(G) cell line and, a subclone (LG7) transformed to IL-3 independent growth by retroviral transduction and expression of the chronic myelogenous leukemia-associated protein tyrosine kinase p210bcr/abl. Cell proliferation 50% inhibitory concentration values ranged from 4 to 250 microM, and one compound was not inhibitory at 500 microM. The dose-cell proliferation curves were remarkably similar for parental 32D cl3(G) cells + IL-3 and LG7 +/- IL-3, and reversion of LG7 cells to IL-3 dependence was not observed, suggesting that none of the compounds tested could selectively inhibit p210bcr/abl. However, 6 compounds induced the appearance of a 200-base pair nucleosomal DNA ladder characteristic of apoptosis at 24 h in parental 32D cl3(G) cells + IL-3, which mimicked the effects of IL-3 withdrawal alone, but not in similarly growth arrested LG7 cells that eventually developed a necrotic pattern of DNA fragmentation. These studies suggest that the expression of p210bcr/abl can suppress apoptotic signal transduction and that this may contribute to the development of the myeloid hyperplasia that occurs in chronic phase chronic myelogenous leukemia.

[Content of trans-fatty acids in food]

The fatty acid composition of the fat in 197 food samples has been analyzed by gas liquid chromatography. The use of a 30 m capillary column coated with CPSil88 permitted the separation of the cis and trans isomers. The trans fatty acid content of milk and milk products ranged from 1.9 to 7.9%. Meat samples from ruminants contained 2.0-10.6% trans fatty acids. In pork fat the amounts were less than 0.5%. Sausages and other meat products contained high levels of pork fat. Therefore these samples contained less than 1% trans fatty acids, with the exception of some pure beef products. The amounts of trans fatty acids in foods which may contain hydrogenated oils ranged from 0 to 34.9%. In food samples with high levels of trans fatty acids lower contents of saturated fatty acids were analyzed.

Clonal evolution in a myeloid cell line transformed to interleukin-3 independent growth by retroviral transduction and expression of p210bcr/abl

Current evidence suggests that the expression of the tyrosine kinase p210bcr/abl in chronic myelogenous leukemia (CML) may directly induce the initial phase of granulocytic hyperplasia. However, the dysregulation of additional genes appears to be required for transition to the acute leukemic phase, as inferred by the appearance of recurrent secondary cytogenetic abnormalities in the majority of patients. To determine whether the expression of p210bcr/abl alone is responsible for this genetic instability, we introduced and expressed the bcr/abl gene from a retroviral vector in a clone of the interleukin-3 (IL-3) dependent myeloblastic 32D C13(G) cell line. Clonal and polyclonal cells transformed to IL-3 independent growth were observed for a period extending up to 6 months for changes in the expression of p210bcr/abl, cell proliferation, inhibition by prostaglandin E1 (PGE1), forskolin, and cyclic adenosine monophosphate (cAMP) analogues, regulation of the cell cycle, and karyotype. Whereas the properties of control vector infected 32D C13(G)' cells remained stable over time, cells expressing p210bcr/abl were phenotypically unstable. In cells expressing p210bcr/abl, we observed selective modulation of p210bcr/abl mRNA and protein expression, evolution from partial to full abrogation of IL-3 dependence, reduced serum requirements, increased cell proliferation, decreased inhibition by PGE1 and cAMP analogues, and the appearance of new structural and numerical chromosomal abnormalities with successive cell passages. These results indicate that expression of p210bcr/abl can directly predispose 32D C13(G)' cells to genetic instability, promotes the emergence of clones with an increased proliferative advantage, and may represent an in vitro model suitable for the study of mechanisms underlying progression to the acute leukemic phase in CML.

Cardiac expression of polysialylated NCAM in the chicken embryo: correlation with the ventricular conduction system

The neural cell adhesion molecule (NCAM) and its polysialic acid moeity (PSA) affect cellular interactions during the development of the nervous system and skeletal muscle. NCAM has also been identified in the embryonic heart of various species including humans. However, knowledge regarding the role of NCAM and its function-modulating PSA in cardiogenesis is limited. The distribution of NCAM and its PSA in the ventricular myocardium of chicken embryos was determined by indirect immunofluorescence staining. The NCAM polypeptide was found throughout the cardiac myocardium. In contrast PSA was located in discrete regions in stage 20 to 44 embryos (during and after septation). Myocardium at the subendocardial regions of the atrioventricular canal and ventricular trabeculae were PSA positive by stage 20. At later stages, transverse sections of the postseptation heart just below the level of the atrioventricular interface revealed a PSA-positive bundle of myocardium in the septum. This bundle was continuous with two branches at a more apical level which in turn were continuous with the PSA-positive subendocardial myocardium lining the left and right ventricles. This pattern of PSA in the myocardium was similar to that of the ventricular conduction system configuration defined in the adult heart. Electron micrographs of the subendocardium of the ventricular septum revealed PSA positivity on myofibril-containing cells with the ultrastructural location of Purkinje fibers. At later stages (35-44) a subset of cells within PSA-positive regions was stained by an antibody against an isoform of the myosin heavy chain found in adult Purkinje fibers. These cells and surrounding tissue lacked PSA in the adult heart. Thus polysialylated NCAM may be modulating cell-cell interactions during the development of the ventricular conduction system.

Expression of immunoglobulin-cross-reactive molecules by neoplastic human T cells. I. Surface detection and isolation of molecules reactive with chicken anti-F(ab')2, anti-alpha and anti-mu antibodies

There is evidence that the T-cell antigen receptor is immunoglobulin-related and that normal human T cells express surface determinants which cross-react with chicken anti-F(ab')2, anti-alpha and anti-mu antibodies. Surface marker study of six neoplastic human T cell lines suggested that F(ab')2- and mu-cross-reactive determinants may be expressed independently of alpha-cross-reactive determinants. F(ab')2-cross-reactive materials--F(ab')2-CRMs--were then isolated from several T-cell lines and analysed by reverse passive haemagglutination and in immunoprecipitation experiments by polyacrylamide disc gel electrophoresis in buffers containing sodium dodecyl sulphate (SDS-PAGE) under reducing conditions. It was shown that MOLT-4- and CCRF-CEM-derived F(ab')2-CRMs differ serologically and that alpha- are indeed expressed independently of F(ab')2- and mu-cross-reactive determinants. The F(ab')2-CRMs were shown to be T cell-derived, to express determinants similar to or identical with F(ab')2-cross-reactive determinants expressed in normal T-cell membranes and to correspond closely to T-cell antigen binding molecules. Evidence was also obtained that the two F(ab')2-CRMs differ from one another in molecular weight. SDS-PAGE under non-reducing conditions of MOLT-4- and CCRF-CEM-derived F(ab')2-CRMs identified major components of mol. wt. 135,000 and mol. wt. 330,000 respectively. Immunoprecipitation of 125I-labelled F(ab')2-CRMs by chicken anti-F(ab')2 followed by SDS-PAGE under reducing conditions identified major components of mol. wt. 80,000 and mol. wt. of 51,000 from CCRF-CEM-derived F(ab')2-CRMs and tentatively identified components of mol. wt. 52,000 and mol. wt. 23,000 from MOLT-4-derived F(ab')2-CRMs.

Reorganization is the key to economical ambulatory health care

The ambulatory health care program presented here has been created using personnel previously employed in the system. Through planning, reorganization, and an evaluation system, a health care program has been developed that has demonstrated both improved care for clients and professional growth for personnel. Health care services are offered at no increase in cost to the provider.

Therapy evaluation and management of patients with hemiplegia

Appropriate treatment of the hemiplegic patient depends on a thorough evaluation of sensation and motion in the affected extremities. Realistic goals for self-care, mobility, home, and community skills may be then established. The basic role of therapy when dealing with a stroke patient includes preventing and correcting deformities, improving a patient's functional ability, and increasing strength, control, and upper extremity use when appropriate. Medical intervention may be necessary to augment the occupational and physical therapy programs in the areas of relief of pain and correction of deformities.