Naive tumour-specific CD4+ T cells were efficiently primed in acute lymphoblastic leukaemia

The recognition and neutralization of tumour cells is one of the big challenges in immunity. The immune system has to recognize syngeneic tumour cells and has to be primed and respond in an adequate manner. Priming of a leukaemia-specific immune response is a crucial step in tumour immunology that can mislead to tumour tolerance either by T cell ignorance, deletion or Treg induction. To resemble the situation of acute lymphoblastic leukaemia (ALL) in patients, we used the murine BALB/c model with syngeneic BM185 tumour cells. We established a tumour cell line that expresses the neo-antigen ovalbumin (BM185-OVA/GFP) to allow the application of T cell receptor transgenic, antigen-specific CD4(+) T cells. Here, we demonstrate that effective anti-ALL immunity can be established by in vivo priming of CD4(+) T cells that is sufficient to differentiate into effector cells. Yet they failed to control tumour alone, but initiated a Th1 response. An efficient tumour clearance was dependent on both antigen-specific CD4(+) T cells and CD8(+) effector T cells from the endogenous repertoire. The tolerogeneic milieu was characterized by increased Tregs numbers and elevated IL-10 level. Tregs hamper effective antitumour immune response, but their depletion did not result in reduced tumour growth. In contrast, neutralization of IL-10 improved median mouse survival. Future therapies should focus on establishing a strong CD4+ T cells response, either by adjuvant or by adoptive transfer.

Gene expression and immunohistochemistry in adipose tissue of HIV type 1-infected patients with nucleoside analogue reverse-transcriptase inhibitor-associated lipoatrophy

BACKGROUND

Long-term use of both zidovudine (AZT) and stavudine (d4T) is associated with lipoatrophy, but it occurs possibly through different mechanisms.

METHODS

Surgical biopsy specimens of subcutaneous adipose tissue were obtained from 18 human immunodeficiency virus type 1 (HIV-1)-infected lipoatrophic patients (the LA+ group) who were treated with either zidovudine (the AZT+LA+ group; n = 10) or stavudine (the d4T+LA+ group; n = 8) and from 10 nonlipoatrophic HIV-1-infected patients (the LA- group) who received antiretroviral therapy. Mitochondrial DNA (mtDNA) copy numbers, gene expression, and immunohistochemistry data were analyzed.

RESULTS

mtDNA copy numbers were significantly reduced in the LA+ group, compared with the LA- group, and in the d4T+LA+ group, compared with the AZT+LA+ group. The ratio of mtDNA-encoded cytochrome COX3 to nuclear DNA-encoded COX4 expression was significantly lower in the LA+ group than in the LA- group. Compared with the LA- group, the LA+ group had significantly lower expression of genes involved in adipogenesis (SREBP1c and CEBPB), lipid (fatty acid synthase), and glucose (GLUT4) metabolism. Expression of genes involved in mitochondrial biogenesis (PGC1B), apoptosis (FAS), inflammation (IL1B), oxidative stress (PCNA and SOD1), and lamin B was significantly higher in the LA+ group than in the LA- group. The d4T+LA+ group had significantly lower expression of genes involved in mitochondrial biogenesis (POLG1), energy metabolism (the COX3/COX4 ratio), adipogenesis (SREBP1c and CEBPA), perilipin, and hexokinase than did the AZT+LA+ group. There were 7-fold more macrophages in adipose tissue specimens obtained from patients in the LA+ group, compared with the LA- group.

CONCLUSIONS

Lipoatrophy is characterized by mtDNA depletion, inflammation, and signs of apoptosis. Changes were more profound in the d4T+LA+ group than in the AZT+LA+ group.

Aggregate characterisation by using the FlocFormer system to improve sludge dewatering

In this paper, the influence of the polymer-induced flocculation on undigested sludge dewatering is investigated by image analysis. The mixing of flocculants in a so-called rapid-mixer and the subsequent forming of aggregates is carried out by the FlocFormer system, a new sludge conditioning system. For the mechanical dewatering a decanter device is used. To evaluate the efficiency of the dewatering process, the total solid content (TS) of the dewatered sludge is analysed. The results of this study show that this type of flocculation represents an alternative to improve sludge dewatering of undigested sludge. Compared with the standard conditioning (T-mixer), the FlocFormer leads to a better improvement (1.37 to 3.46%-points) in terms of TS while the rapid-mixer improves the dewatering efficiency only by 0.50 to 1.73%-points. Additionally, by using the FlocFormer conditioning, an optimal polymer dose of 5 g/kg TS has been detected. By increasing the polymer consumption (4-20% above the optimal dose) the dewatering efficiency remains practically constant (TS approximately 26.5%).

Detection of unstable carotid artery stenosis using MRI

BACKGROUND AND PURPOSE

Carotid artery stenosis can be classified by magnetic resonance imaging (MRI) as lesion types I-VIII according to a modified histological scheme based on American Heart Association (AHA) guidelines. Lesion types IV-V and VI are regarded as high-risk plaques.We aimed to evaluate the clinical relevance of this classification for identifying unstable plaques.

METHODS

Eighty-five patients (29 female) with severe carotid artery stenosis (diagnosed by Doppler and duplex ultrasonography) were imaged using a 1.5 T scanner with bilateral phased-array carotid coils. T1-, T2-, time-offlight (TOF) and proton-density (PD)-weighted studies were obtained. The carotid plaques were classified as lesion types III-VIII according to the MRI-modified AHA criteria.

RESULTS

Thirty-five patients presented with a recently symptomatic stenosis; 50 patients were asymptomatic. Lesion types IV-V (51.4 % vs. 22 %) and VI (20 % vs. 4%; P < 0.0001) were found significantly more often in symptomatic patients compared to those without a history of cerebral ischemia.

CONCLUSIONS

The distribution of lesion types differs significantly between symptomatic and asymptomatic carotid artery stenosis. High-risk lesion types IV-V and VI were overrepresented in recently symptomatic patients. MRI according to the modified AHA-criteria may be a suitable tool for detection of unstable carotid lesions.

The impact of sequential ozonation--aerobic treatment on the enhancement of sludge dewaterability

Sludge ozonation processes have mostly been considered as regards the minimisation of the bio-solids while the improvement of sludge dewatering was more a welcoming side-effect. However, some papers announce a decrease of the dewatering efficiency by sludge ozonation. This indicates the presence of an optimisation potential, which is the subject of this study. Improvement of sludge dewaterability was found for an ozone dose which is much lower than that used for sludge minimisation. The repeated ozone and aerobic treatment allows further strong improvement of dewatering efficiencies. The key for this process optimisation is a well-balanced ozone dose related to the subsequent aerobic treatment time.

An overview of the integration of ozone systems in biological treatment steps

Despite the well-known potential and performance of combined biological and ozonation processes for wastewater treatment, only few full-scale applications are published. Beside the synergistic effects of such process combination, which lead to oxidation of recalcitrant and inhibitory compounds or intermediates by enhancement of their biodegradability, the key for raising applicability is the improvement of the ozonation efficiency. An overview about the history and progress of full-scale applications, which deals with combined ozonation and biological treatment is given. Recently more than 40 applications exist, but many of them are not published. Therefore, a couple of selected not yet published applications have been mentioned in this paper. Landfill leachate and industrial wastewater treatment were mostly applicated, while treatment of municial wastewater treatment plant (WWTP) effluents are of increasing interest due to several advantages such as disinfection, decolourisation and removal of persistent dissolved organic carbon (DOC) for water re-use and groundwater recharge.

Do human osteoblasts grow into open-porous titanium?

A titanium foam for spine fusion and other applications was tested by cell culture. Its high porosity and surface roughness should enable bone cells to grow through it, resulting in a better fixation of the vertebral body. The foam was tested by in vitro experiments with human osteoblasts under static culture conditions and in a perfused system. By means of cell number, viability, scanning electron microscopy and histological staining, cell proliferation could be observed. The expression of osteogenic genes like collagen-I, alkaline phosphatase and osteocalcin was proven by reverse transcription polymerase chain reaction (RT-PCR) as well as in the case of alkaline phosphatase with biochemical methods. The conducted experiments showed that human osteoblasts could grow through the interconnected porosity of the metal foam and that they expressed an osteoblast like phenotype. The results suggest that in vivo osteoblasts are likely to form a trabecular bone bridge through this titanium foam. Consequently, with this osteoconductive material, there may be a reduced need for autologous bone in spinal fusion procedures.

[A telephone hotline as an easily accessible service for questions on schizophrenia]

Public relations activities of the German Research Network on Schizophrenia (GRNS) have shown that there is a demand for more information about schizophrenia disorder. This confirms international research findings that relatives of schizophrenia patients are particularly in need of information and support. In response, the GRNS has maintained a telephone hotline since 2001. The hotline is manned by clinical experts, psychiatrists, or psychologists once a week. The telephone calls are documented in a systematic manner. From 2001 to 2003, 3,909 calls were registered. This volume exceeds the limit of the hotline's resources. The telephone hotline is mainly used by relatives of psychotic patients. Most questions relate to the symptoms of schizophrenia and pharmaceutical treatment. The need for emotional support is also a high motivational factor for dialing the hotline number. The telephone hotline seems to be a worthwhile addition to the already existing crisis telephones and should be maintained even after public funding of the network expires.

[Diagnostics and therapy of depressive symptoms in schizophrenic patients]

The occurrence of depressive symptoms in schizophrenia is fairly common. In contrast to earlier assumptions, they usually have unfavorable consequences on the course of the disease. The response of depressive symptoms to therapy is well documented by empirical evidence and studies. In reality, however, the treatment of depressive symptoms in cases of schizophrenia occurs too rarely. This lack of medical treatment is partially explained by the clinicians' apprehension that antidepressive therapy could provoke a flare up of the psychosis. Nonetheless, this situation is often founded on the incorrect assessment of the depressive symptoms as negative symptoms that, in turn, are regarded by many clinicians as having limited treatability. In regards to this circumstance, a rethinking is desirable and, as a matter of principle, necessary.

Obsessive-compulsive Disorder (OCD) with Psychotic Symptoms and Response to Treatment with SSRI

The co-occurrence of obsessive-compulsive and psychotic symptoms in one patient often represents a diagnostic problem. Distinguishing among a schizophrenic disorder with comorbid obsessional symptoms, an OCD with comorbid psychotic symptoms, or an OCD and schizophrenia or any other psychotic disorder is of clinical importance, since the different diagnoses have different therapeutic as well as prognostic implications. In the following case report we describe a patient who suffered from a typical OCD for more than 18 years and then developed clear psychotic symptoms that completely remitted after treatment with citalopram.

Sludge treatment by ozonation--evaluation of full-scale results

Ozonation of industrial and sewage sludge is a suitable process for minimizing the sludge production of activated sludge processes. The ozonation has the advantage for complete oxidation of volatile suspended solids (VSS) of combining partial sludge oxidation with subsequent biological oxidation. This paper describes the evaluation of two full-scale sewage sludge ozonation investigations for subsequent aerobic stabilisation as well as for subsequent anaerobic stabilisation compared to different sludge treatment processes. For both the anaerobic and aerobic application, sludge liquefying by release of 110 and 160 mg COD per g total suspended solids (TSS) has been reached at specific ozone consumption of 0.03 and 0.06 kg O3 per kg TSS, respectively. The subsequent biological treatment has reached a mass reduction of 20-35% for the aerobic and 19% for the anaerobic stabilisation. For both applications the specific ozone consumption was about 0.05 kgO3 per kg TSS to be treated. A comparison with mechanical and thermo-chemical sludge mass reduction methods shows that the mass reduction potential of ozonation is presently higher. Even though costs for sludge ozonation are higher compared to other methods, the optimisation potential for cost reduction of sludge ozonation is obvious from the results presented in this paper.

Pre-nitrification by encapsulated nitrifiers--a possibility for self-sufficient energy operation of domestic WWTPs

The overall energy consumption of domestic wastewater treatment plants (WWTPs) increases with treatment efficiency. Approximately 30 to 45 kWh per people equivalent and year is mostly necessary for advanced nitrogen and phosphorus removal, while the aeration contains the main part of approximately 60%. A new process using encapsulated nitrifiers on gel lens beads is introduced to overcome the high energy consumption of aeration. A more selective nitrification process was found at a nitrification rate of between 50 and 60 mg nitrogen per hour and litre reaction volume corresponding to a hydraulic retention time (HRT) of about 30 to 60 minutes while the soluble Chemical Oxygen Demand (COD) removal could be less than 30% depending on operational conditions of the bio-reactor. The latter enables internal use of wastewater's COD for a post denitrification. For the new process the energy consumption as well as total volume of bio-reactor are much less (approximately 30 to 50% for both) than conventional processes due to the low sludge age for COD and nitrate removal and the avoidance of internal wastewater recycle. Therefore, self-sufficient energy operation of domestic WWTPs operating with advanced treatment efficiency could become possible, if energy recovery by anaerobic sludge digestion is included.

Advanced nitrogen elimination by encapsulated nitrifiers

By introducing a mixed population of nitrifiers encapsulated in gel lens beads a more selective nitrification process was found in treatment of settled sewage in lab scale at a hydraulic retention time (HRT) of about 30 to 60 minutes. The reaction rates for oxidation of soluble chemical oxygen demand (SCOD) were found to vary between 25 to 150 mg/L x h while nitrification takes place around 50 mg nitrogen per hour and litre reaction volume. However, based on this SCOD removal in the nitrification step, a consequent post-denitrification process without nitrate recycle and dosage of external carbon sources has been proven to reach substantial nitrate elimination of up to 20 mg nitrogen per litre at COD/N-ratios of approx. 6 in settled sewage. At such COD/N-ratios, suitable nitrogen elimination seems to be possible, because the bioflocs of settled sewage, produced so far by SCOD oxidation and entrapment of particulate COD, are passing through the nitrification process having a substantial contribution to the denitrification rate additionally to the remaining SCOD.

Automation in sludge dewatering by novel on-line characterisation of flocculation

A novel on-line method and system for characterisation of sludge flocs in view of improving sludge dewatering has been developed. The characterisation of sludge flocs was carried out after the conditioning or the flocculation process. The system uses a conventional CCD-line scan camera providing an on-line monitoring of the relative floc size distribution by image processing procedures. The image processing procedure has been re-evaluated and adapted to the practical dewatering results, obtained from a chamber filter press of 250 x 250 mm size. A good correlation between the calculated sensor signal and the sludge dewaterability of digested sludge in terms of the up-concentration factor was found. Although different sludge compositions and flocculation systems have been tested within the whole experimental period of six months, a good reproducibility of this correlation was also found. A well balanced floc size distribution is necessary showing that not too many but still some fine flocs and also not too large but compact flocs lead to improved dewaterability. This has been illustrated by an extended range of floc size measurements ranging between 50 microm and 29 mm. The conditioning monitoring system would be suitable for the control of production of good size-balanced flocs to compensate fluctuations in sludge characteristics of the sludge to be conditioned.

Ultrasonic cell disruption of stabilised sludge with subsequent anaerobic digestion

The world-wide increasing environmental awareness and its subsequent regulations have led to the application of improved technologies in wastewater purification plants. This has resulted in higher wastewater and sludge productions. Sludge is the by-product of such plants and it is not only rich in organic carbon and pathogens but also in heavy metals and other environmental pollutants. In Europe, agricultural application of dried sludge (bio-solids) is confronted with negative reactions from the citizens, governmental organisations, farmers and the food industry. Ultrasonic disruption of sludge is a popular mechanical disruption process in sludge treatment. During ultrasonic treatment, high frequency acoustic signals are used to initiate the cavitation process. The applied ultrasonic field leads to a breakdown of cohesive forces of the liquid molecules resulting in the generation of cavitation bubbles. A shock wave is released by the collapse of the cavitation bubbles and propagates in the surrounding medium forming jet streams that cause the disruption of cells in sludge. Disruption of sludge cells enables the release of light organic substances into the sludge water thereby exposing them for further anaerobic digestion. This paper presents results on the disruption of conventionally stabilised sludge through the application of the ultrasonic field. In order to reduce the specific energy input (i.e. ratio of the consumed energy during ultrasonic disruption to the input sludge mass) and improve biogas production, the total solids content of the stabilised sludge was increased before disruption. The anaerobic digestion of sludge samples was carried out in a set of specially constructed laboratory anaerobic digesters. Results showed that subsequent anaerobic digestion of the ultrasonically disrupted sludge could improve biogas production with reduced sludge quantity that is vital to the economic consideration of the wastewater treatment plants. This process encourages the exploitation of valuable materials and energy from stabilised sewage sludge just before its final disposal. The negative effects of mixing disrupted sludge with its separated sludge water are also shown in this paper. This expresses the microbiological instability of the anaerobic process caused by the mixing process.

Ultrasound stimulation of micro-organisms for enhanced biodegradation

An ultrasound (US)-assisted bioprocess for wastewater treatment for the food industry was developed in a three years EC-funded project (FAIR CT-3259). An improvement of biological activity by US was successfully demonstrated with lab scale reactors [Schläfer et al. Ultrasonics 38 (2000)]. Now a pilot scale optimisation with a 200 l bioreactor was carried out in co-operation with the Department of Industrial Acoustics, Technical University of Denmark and RESON A/S (Denmark). Batch experiments have been performed by measuring the degradation rate of organic compounds of wastewater. The process parameters were kept constant while varying the US-intensity. A significant increase of biological activity could be obtained only in a very narrow range of US-intensity. Very low US-power leads to a decrease of degradation rate down to the standard value if there is no US-intake. Implementation of too high level of US lead to drastically decreasing of the biological activity to a level far below the Standard value if there is no US-intake. The optimisation of this narrow US-power window needs to be carried out carefully for every investigated bioprocess. The most important aspect of the experimental results was that a more than 100% increase of the maximum biological degradation rate has been achieved by US-transduction with an optimum US-intensity of 1.5 W/l wastewater at 25 kHz. The developed bioprocess reduces the overall energy by use of low-energy US-irradiation below the cavitation level. The US-assisted biological degradation process would be presented together with its optimisation and the economical calculation.

Fibromyalgia-symptom or diagnosis: a definition of the position

According to the American College of Rheumatology the diagnosis of fibromyalgia is based on criteria for the classification of fibromyalgia consisting entirely of clinical signs and symptoms. For diagnostic reasons autonomic disturbances and mental features have to be considered. The distinction between fibromyalgia (tender points) and myofascial pain syndrome (trigger points) is essential. Internal and neurological disorders as a primary cause of fibromyalgia have to be excluded. The etiology and pathogenesis of fibromyalgia still remain uncertain. The myopathological patterns in fibromyalgia are non-specific: type II fiber atrophy, an increase of lipid droplets, a slight proliferation of mitochondria, and a slightly elevated incidence of ragged red fibers. Initial reports on some allelic abnormalities in the serotonin system seem to highlight the important role of serotonin already presumed earlier. Significantly high levels of substance P in the cerebrospinal fluid of FM patients additionally support the impact of these neurotransmitters on both nociceptive and antinociceptive mechanisms.

Improvement of biological activity by low energy ultrasound assisted bioreactors

Bioreactors are broadly applied in biotechnology and wastewater treatments. The so-called advanced bioreactor systems should be optimised in a more compact, more efficient and more effective form. One method of optimisation is the improvement of the solid-liquid interface of the sludge flocs and the mass transfer rate of gas and nutrients in the liquid. This could be obtained by the intake of ultrasound in the bioreactor at a frequency of 25 kHz and a power input of 0.3 Wl-1. An increase in the biological activity of the process investigated with alternating ultrasound as well as a decrease without ultrasound were measured.

Procedural and late outcomes following MULTI-LINK DUET coronary stent deployment

The MULTI-LINK DUET is the next generation MULTI-LINK stent with modified strut geometry. Safety and efficacy of the MULTI-LINK DUET were evaluated in a prospective multicenter registry and were compared with prior MULTI-LINK stent experience from the ASCENT randomized trial. A total of 270 patients received 302 MULTI-LINK DUET stents and were evaluated using a composite primary end point of major cardiac events (death, Q-wave and non-Q-wave myocardial infarction, and requirement for coronary revascularization) attributable to the target stenosis cumulative to 30 days following enrollment. Quantitative coronary angiography was performed at a mean follow-up of 6 +/- 2 (+/-SD) months. No difference in primary end point or in angiographic restenosis to 6 months was observed between MULTI-LINK DUET and MULTI-LINK experiences. The MULTI-LINK DUET demonstrated improved device and procedural success, less postprocedural in-stent stenosis, larger postprocedural minimal lumen diameter, and fewer postprocedural marginal dissections compared with the MULTI-LINK stent. Multivariate regression modeling identified stent length, diabetes mellitus, poststent minimal lumen diameter, lesion eccentricity, and current smoking as independent predictors of in-stent restenosis. Thus, the MULTI-LINK DUET Registry demonstrates enhanced procedural performance with clinical and angiographic outcomes similar to those previously observed for the MULTI-LINK stent in the ASCENT randomized trial.

Phylogenetic identification of two major nitrogen-fixing bacteria associated with sugarcane

Acetobacter diazotrophicus and Herbaspirillum seropedicae were identified by genetic methods based on 16S rRNA sequences. A specific PCR method in combination with probing was developed for A. diazotrophicus. The PCR system includes four primers, of which the primers named AC (CTGTTTCCCGCAAGGGAC) and DI (GCGCCCCATTGCTGGGTT) generated an 445 bp amplicon in all of the 11 A. diazotrophicus strains tested. The phylogenetic position of H. seropedicae was determined. H. seropedicae forms with Oxalobacter formigenes a separate lineage in the beta-subclass of Proteobacteria.

Acetobacter intermedius, sp. nov

Strains of a new species in the genus Acetobacter, for which we propose the name A. intermedius sp. nov., were isolated and characterized in pure culture from different sources (Kombucha beverage, cider vinegar, spirit vinegar) and different countries (Switzerland, Slovenia). The isolated strains grow in media with 3% acetic acid and 3% ethanol as does A. europaeus, do, however, not require acetic acid for growth. These characteristics phenotypically position A. intermedius between A. europaeus and A. xylinus, DNA-DNA hybridizations of A. intermedius-DNA with DNA of the type strains of Acetobacter europaeus, A. xylinus, A. aceti, A. hansenii, A. liquefaciens, A. methanolicus, A. pasteurianus, A. diazotrophicus, Gluconobacter oxydans and Escherichia coli HB 101 indicated less than 60% DNA similarity. The important features of the new species are described. Acetobacter intermedius strain TF2 (DSM11804) isolated from the liquid phase of a tea fungus beverage (Kombucha) is the type strain.

All-cause mortality and cardiovascular disease mortality in three American Indian populations, aged 45-74 years, 1984-1988. The Strong Heart Study

Community mortality surveillance for 1984-1988 was conducted by researchers of the Strong Heart Study, which examined the incidence, prevalence, and risk factors of cardiovascular disease in three American Indian populations, aged 45-74 years, in Arizona, Oklahoma, and South/North Dakota. All-cause and cardiovascular disease mortality rates were determined through the use of death certificate data. Cardiovascular disease deaths were confirmed by independent systematic review of medical records. In all three populations, men had higher all-cause and cardiovascular disease mortality rates than did women. Oklahoma exhibited slightly lower 5-year, age-adjusted, all-cause mortality (96/1,000) than did Arizona (107/1,000) and South/North Dakota (114/1,000). The leading cause of death among both sexes in Oklahoma and in South/North Dakota was cardiovascular disease. Diabetes mellitus led among Arizona women. The other major causes of death were cancer, liver disease including cirrhosis, and injury. When compared with the rates in each state, average annual all-cause mortality rates were higher for the American Indian populations in almost every age group. The all-cause annual mortality rates in the three Indian populations were close to rates in the US black population and higher than the rates of the entire US population and of US whites. This trend was amplified in the 45- to 64-year age group. Only in the 65- to 74-year age group did mortality rates in the Indian population approach those of the US population. Cardiovascular disease mortality rates were close to the US averages in Arizona and Oklahoma, but they were more than two times higher in South/North Dakota among those between 45 and 64 years of age. Thus, American Indians in Arizona, Oklahoma, and South/North Dakota exhibit high all-cause mortality rates. In particular, the South/North Dakota population cardiovascular disease death rate appears to present a potential target for community-based programs to intervene on known risk factors to promote healthy lifestyles.

Purification and properties of citrate synthase from Acetobacter europaeus

Citrate synthase (EC 4.1.3.7) was purified from the acidophilic bacterium Acetobacter europaeus to electrophoretic homogeneity. The specific activity was 228 units/mg of protein during the exponential ethanol-oxidation growth phase. The enzyme has a molecular mass of 280 kDa and is a hexamer with a subunit size of 46 kDa. The apparent K(m) values were 20 microM for oxaloacetate and 51 microM for acetyl-CoA. Unlike citrate synthase from other Gram-negative bacteria, the activity of the enzyme was inhibited by ATP, slightly enhanced by ADP and not effected by NADH. Acetate caused activation of the enzyme. The pH optimum on the citrate synthase activity in vitro was 8.1. The amino-terminal amino acid sequence of the purified enzyme was ENGKSATISLNGKDVALPVL.

16S-23S ribosomal RNA spacer regions of Acetobacter europaeus and A. xylinum, tRNA genes and antitermination sequences

The 16S-23S ribosomal RNA spacer regions of Acetobacter europaeus DSM 6160, A. xylinum NCIB 11664 and A. xylinum CL27 were amplified by PCR. Specific PCR products were obtained from each strain and their nucleotide sequences determined. The spacer region of A. europaeus comprises 768 nucleotides (nt), that of A. xylinum 778 nt and that of A. xylinum CL27 759 nt. Genes encoding tRNAIle and tRNAAla were identified. Putative antitermination sequences were found between the tRNAAla sequence and the 5'-terminus of the 23S rRNA coding sequence. The boxA element has the nucleotide sequence TGCTCTTTGATA. Based on hybridization data of digested chromosomal DNA with spacer-specific probes, the copy number of the rrn operons on the chromosome of Acetobacter strains is estimated to be four.

A monoclonal antibody-cobra venom factor conjugate increases the tumor-specific uptake of a 99mTc-labeled anti-carcinoembryonic antigen antibody by a two-step approach

Monoclonal antibodies (mabs) have considerable potential for specific cancer treatment. However, due to the antigen heterogeneity and especially the low uptake in solid tumors, mabs have not been used successfully in most clinical trials to date. This study investigates the effects of a mab-cobra venom factor (CVF) conjugate in vitro and in vivo in an orthotopic pancreatic cancer model using nude rats. CVF, a nontoxic glycoprotein from cobra venom, permanently activates the alternative pathway of complement. Coupled to a mab with tumor-binding properties, the complement activation can be targeted to the tumor tissue. We studied the activity of a mab CA19-9-CVF conjugate with the human pancreatic cancer cells PancTu I. PancTu I cells express the complement resistance factors CD46, CD55, and CD59, as we demonstrated by immunostaining, an observation that may explain the lack of cytotoxicity of the CA19-9-CVF conjugate. However, using ELISA, Western blot, and immunostaining, we showed that CA19-9-CVF activates the complement cascade, including the release of the anaphylatoxin C3a, a mediator of an inflammatory reaction. The in vivo studies of CA19-9-CVF-treated nude rats showed an increased tumor infiltration by natural killer cells and macrophages. The tumor uptake of 99Tc-labeled anti-carcinoembryonic antigen antibody was increased approximately 2-fold in rats pretreated with 70 micrograms of CA19-9-CVF, compared to animals that received an equimolar mixture of noncoupled mab and CVF. This study indicates the value of mab-CVF conjugates in adjuvant immunotherapy. mab-CVF conjugates might be useful in pretargeting approaches by increasing the uptake of a therapeutic mab.

Phylogenetic position of Gluconobacter species as a coherent cluster separated from all Acetobacter species on the basis of 16S ribosomal RNA sequences

The 16S rRNA sequences from the Gluconobacter species G. asaii, G. cerinus and G. frateurii were determined and compared with homologous sequences from published databases and sequences of G. oxydans and Acetobacter species previously described [Sievers, M., Ludwig, W. and Teuber, M. (1994) System. Appl. Microbiol. 17, 189-196]. The Gluconobacter species have unique 16S rRNA sequences and exhibit sequence similarity values of 97.4 to 99.1%, corresponding to 36 to 14 base differences. The phylogenetic tree inferring methods (distance matrix, maximum parsimony and maximum likelihood) show that the species of Gluconobacter form a coherent, closely related cluster. Based on the distance matrix method including Rhodopila globiformis as an outgroup reference organism, Gluconobacter is well separated from Acetobacter.