The current state of two-dimensional electrophoresis with immobilized pH gradients

The original protocol of two-dimensional electrophoresis with immobilized pH gradient (IPG-Dalt; Gorg et al., Electrophoresis 1988, 9, 531-546) is updated. Merits and limits of different methods for sample solubilization, sample application (by cup-loading or ingel rehydration) with respect to the pH interval used for IPG-isoelectric focusing are critically discussed. Guidelines for running conditions of analytical and micropreparative IPG-Dalt, using wide IPGs up to pH 12 for overview patterns, or narrow IPGs for zoom-in gels for optimum resolution and detection of minor components, are stated. Results with extended separation distances as well as automated procedures are demonstrated, and a comparison between protein detection by silver staining and fluorescent dyes is given. A brief trouble shooting guide is also included.

Electrophoretic characterization of wheat grain allergens from different cultivars involved in bakers' asthma

In order to identify and characterize the wheat grain allergens involved in bakers' asthma, proteins were sequentially extracted from whole-meal flour. The polypeptide composition of the individual solubility fractions (albumin/globulin, gliadin and glutenin) was analyzed by sodium dodecyl sulfate-gel electrophoresis (SDS-PAGE), and high-resolution two-dimensional gel electrophoresis with immobilized pH gradient 4-9 in the first dimension (IPG-Dalt). The resolved polypeptides were transferred onto an immobilizing polyvinylidene difluoride membrane and incubated with a pooled serum from four asthmatic bakers. Bound IgE was demonstrated by autoradiography using 125I-labeled anti-human IgE. Our study demonstrated that the serum of the bakers allergic to flour contained IgE antibodies which bound to numerous polypeptides of all three solubility fractions. The highest percentage of IgE binding was observed with certain albumin and/or globulin polypeptides, whereas the gliadins and glutenins exhibited considerably less allergenicity. SDS-PAGE revealed that the protein which bound the highest percentage of IgE from the sera of the allergic bakers is a 27 kDa albumin. More detailed investigations using IPG-Dalt demonstrated that this allergen is not a single polypeptide but consists of several polypeptide spots that differ in their isoelectric points. Quantitative studies using computer-assisted laser densitometry revealed that the amount of patients' IgE bound by these particular polypeptides differed considerably between the seven wheat cultivars examined, ranging from 13% to 53% of the total radioactive uptake.

Two-dimensional polyacrylamide gel electrophoresis with immobilized pH gradients in the first dimension (IPG-Dalt): the state of the art and the controversy of vertical versus horizontal systems

After having established the basic protocol of two-dimensional electrophoresis with immobilized pH gradients in the first dimension (IPG-Dalt) in 1988 (A. Görg et al., Electrophoresis 1988, 9, 531-546), some critical parameters of the actual IPG-Dalt protocols as well as the results obtained with horizontal and vertical second-dimensional sodium dodecyl sulfate-electrophoresis are demonstrated and discussed.

Recent developments in two-dimensional gel electrophoresis with immobilized pH gradients: wide pH gradients up to pH 12, longer separation distances and simplified procedures

Wide-range immobilized pH 3-12 and 6-12 gradients were generated. Depending on the extraction method of sample preparation, proteins with p/s up to pH 11.7 were resolved. Highly reproducible protein patterns, focused to the steady-state with round-shaped spots up to the basic end were obtained. Moreover, because a strong water transport from cathode to anode (reverse electroendosmotic flow) inherent to narrow immobilized pH gradients (IPGs) exceeding pH 11, such as IPG 10-12, was negligible, the wide-range IPGs 3-12 and 6-12 could be run under standard conditions as originally described by Görg et al (Electrophoresis 1988, 9, 531-546). The wide-range immobilized pH gradient 3-12 proved to be perfectly suited for an overview separation of total cell extracts. Resolution could be increased by extending the separation distance from 18 to 24 cm. Furthermore, two-dimensional gel electrophoresis with IPGs (IPG-Dalt) was simplified by the use of an integrated system (IPGphor) where sample application by in-gel rehydration and isoelectric focusing (IEF) are performed automatically in a one-step procedure, overnight, without human assistance.

A placebo-controlled, double-blind, randomized, two-center, pilot trial of Cop 1 in chronic progressive multiple sclerosis

We found Cop 1 to be effective and relatively safe in a previous (exacerbating-remitting) clinical trial. This current trial involves 106 chronic-progressive patients. The major end point, confirmed progression of 1.0 or 1.5 units (depending on baseline disability) on the Kurtzke Expanded Disability Status Scale, was observed in nine (17.6%) treated and 14 (25.5%) control patients. The differences between the overall survival curves were not significant. Progression rates at 12 and 24 months were higher for the placebo group (p = 0.088) with 2-year probabilities of progressing of 20.4% for Cop 1 and 29.5% for placebo. We found a significant difference at 24 months between placebo and Cop 1 at one but not the other center. Two-year progression rates for two secondary end points, unconfirmed progression, and progression of 0.5 EDSS units, (p = 0.03) are significant.

Towards higher resolution: two-dimensional electrophoresis of Saccharomyces cerevisiae proteins using overlapping narrow immobilized pH gradients

The rising number of proteome projects leads to new challenges for two-dimensional electrophoresis with immobilized pH gradients and different applications of this technique. Not only wide pH gradients such as 4-12 or 3-12 (Görg et al., Electrophoresis 1999, 20, 712-717) which can give an overview of the total protein expressions of cells are in demand but also overlapping narrow immobilized pH gradients are to be used for more specialized and detailed research and micropreparative separations. The advantage of overlapping narrow pH gradients is the gain in higher resolution by stretching the protein pattern in the first dimension. This simplifies computer-aided image analysis and protein identification (e.g., by mass spectrometry). In this study the protein patterns of yeast cells in pH gradients 4-5, 4.5-5.5, 5-6, 5.5-6.7 and 6-9 are presented and compared to the pH 4-7 and 3-10 gradients. This combination allowed us to reveal a total of 2286 yeast protein spots compared to 755 protein spots in the pH 3-10 gradient.

Improving protective immunity induced by DNA-based immunization: priming with antigen and GM-CSF-encoding plasmid DNA and boosting with antigen-expressing recombinant poxvirus

Intramuscular immunization with a naked DNA plasmid expressing the Plasmodium yoelii circumsporozoite protein (pPyCSP) protects mice against challenge with P. yoelii sporozoites. This protection can be improved either by coadministration of a plasmid expressing murine GM-CSF (pGMCSF) or by boosting with recombinant poxvirus expressing the PyCSP. We now report that combining these two strategies, by first mixing the priming dose of pPyCSP with pGMCSF and then boosting with recombinant virus, can substantially increase vaccine effectiveness. Not only were immune responses and protection improved but the pPyCSP dose could be lowered from 100 microg to 1 microg with little loss of immunogenicity after boost with recombinant poxvirus. Comparing mice primed by the 1-microg doses of pPyCSP plus 1 microg pGMCSF with mice primed by 1-microg doses of pPyCSP alone, the former were better protected (60% vs 0) and had higher concentrations of Abs (titers of 163, 840 vs 5, 120 by indirect fluorescent Ab test against sporozoites), more ex vivo CTL activity (25% vs 7% specific lysis), and more IFN-gamma-secreting cells by enzyme-linked immunospot assay (1460 vs 280 IFN-gamma spot-forming cells/106 cells). Priming with plasmid vaccine plus pGMCSF and boosting with recombinant poxviruses strongly improves the immunogenicity and protective efficacy of DNA vaccination and allows for significant reduction of dose.

The Dead Sea: Deepening of the Mixolimnion Signifies the Overture to Overturn of the Water Column

Throttling of freshwater inputs into the meromictic Dead Sea weakened the long-term stability of the water column. Between 1975 and 1978 successive deepenings of the pycnocline from 70 meters to beyond 200 meters were recorded. Complete overturn finally took place during the winter of 1978-1979. This unique process was accompanied by changes in the geochemistry of several components.

Two-dimensional electrophoresis of proteins in an immobilized pH 4-12 gradient

For checking theoretical two-dimensional (2-D) maps derived from sequenced genomes, indicating that nonnegligible amounts of proteins up to pH 12 are to be expected, a wide-range immobilized pH 4-12 gradient was generated. Depending on the extraction method of sample preparation, proteins with pls up to pH 12 are detected in a single gel. Highly reproducible protein patterns focused to the steady state with round-shaped spots up to pH 12 are obtained with the standard protocol originally described in 1988 (Görg et al., Electrophoresis 1988, 9, 531-546).

Detection and analysis of xenon isotopes for the comprehensive nuclear-test-ban treaty international monitoring system

The use of the xenon isotopes for detection of nuclear explosions is of great interest for monitoring compliance with the comprehensive nuclear-test-ban treaty (CTBT). Recently, the automated radioxenon sampler-analyzer (ARSA) was tested at the Institute for Atmospheric Radioactivity (IAR) in Freiburg, Germany to ascertain its use for the CTBT by comparing its results to laboratory-based analyses, determining its detection sensitivity and analyzing its results in light of historical xenon isotope levels and known reactor operations in the area. Xe-133 was detected nearly every day throughout the test at activity concentrations ranging between approximately 0.1 mBq/m3 to as high as 120 mBq/m3. Xe-133m and 135Xe were also detected occasionally during the test at concentrations of less than 1 to a few mBq/m3.

Rapid thrombectomy with a hydrodynamic catheter: results from a prospective, multicenter trial

PURPOSE

To evaluate efficacy and safety of a hydrodynamic rheolytic thrombectomy device for rapid percutaneous treatment of acute thromboembolic occlusions of native lower-extremity arteries and bypass grafts.

MATERIALS AND METHODS

In 50 patients, thrombectomy was performed with the rheolytic catheter at four centers. Patients had acute occlusions of native lower-extremity arteries (n = 39) or acute thrombosis of lower-limb bypass grafts (n = 11). Estimated occlusion age was 5 days +/- 5. Mean thrombus length was 15 cm +/- 11. Clinical success was measured on a scale of -3 (deterioration) to +3 (improvement) with established criteria.

RESULTS

With the thrombectomy catheter, the majority of thrombus material was removed and antegrade blood flow was reestablished in 45 (90%) patients. Technical success (residual luminal narrowing < 50%) was 52% with use of the device alone. Adjunctive therapy was performed in 45 patients. Clinical improvement after intervention was +3 in 25 (50%) patients, +2 in 10 (20%), +1 in six (12%), and 0 (no improvement) in nine (18%). Clinically unimportant complications related to use of the device were one (2%) distal embolization and two (4%) dissections. Laboratory analysis revealed hemolysis without clinical sequelae. Primary patency rates were 76% after 30 days, 74% after 3 months, and 69% after 1 year.

CONCLUSION

The hydrodynamic catheter appears to be safe and effective for rapid thrombectomy.

Trimetrexate with leucovorin versus trimethoprim-sulfamethoxazole for moderate to severe episodes of Pneumocystis carinii pneumonia in patients with AIDS: a prospective, controlled multicenter investigation of the AIDS Clinical Trials Group Protocol 029/031

Trimetrexate is a powerful inhibitor of the dihydrofolate reductase of Pneumocystis carinii. AIDS patients (n = 215) with moderate to severe P. carinii pneumonia were enrolled in a double-blind study of trimetrexate plus leucovorin versus trimethoprim-sulfamethoxazole (TMP-SMZ) for 21 days. By study day 10, study therapy failed because of lack of efficacy in 16% of patients assigned to TMP-SMZ and 27% assigned to trimetrexate (P = .064), and the PAO2-PaO2 improved significantly faster with TMP-SMZ. By study day 21, failure rates were 20% with TMP-SMZ and 38% with trimetrexate (P = .008), with respective mortality rates of 12% and 20% (P = .088). By study day 49, the difference in mortality (16% vs. 31%) was significant (P = .028). The cumulative incidence of serious and treatment-terminating adverse events including hematologic toxicities was less with trimetrexate (P < .001). Thus, trimetrexate plus leucovorin was effective, albeit inferior to TMP-SMZ, for moderately severe P. carinii pneumonia but was better tolerated than TMP-SMZ.

A double-blind study of the effectiveness of cyclosporine in amyotrophic lateral sclerosis

In a double-blind placebo-controlled trial of cyclosporine in amyotrophic lateral sclerosis, no differences were observed in the monthly rate of progression or the relative risk of progression in comparing 38 patients randomized to the placebo group and 36 patients randomized to the cyclosporine group. In comparing three subgroups of patients, cyclosporine appeared to benefit men who entered the study within 18 months of the onset of first symptoms, whereas it was of no value to women or to men who entered later than 18 months. For the men with recent onset of disease, the relative risk of progression was 0.403; the monthly rate of progression was 5.2 +/- 1.1 points with placebo and 3.5 +/- 0.7 points with cyclosporine. These provocative results support the need for a full study of cyclosporine in men with recent onset of disease.

The pancreas as a site of granulomatous inflammation in Crohn's disease

Several reports on the occurrence of pancreatic dysfunction complicating Crohn's disease have been published during the past few years. Nevertheless, the pathogenesis of these disorders remains controversial. In this report, we describe a patient presenting with extrahepatic cholestasis and a mass in the head of the pancreas. Histological examination showed a granulomatous inflammation caused by Crohn's disease involving the stomach, the duodenum, and the head of the pancreas, clearly showing that the pancreas can also be a localization of Crohn's disease. Granulomatous inflammation could be an important factor in the pathogenesis of pancreatic dysfunction occurring in association with Crohn's disease.

Multistage multiantigen heterologous prime boost vaccine for Plasmodium knowlesi malaria provides partial protection in rhesus macaques

A nonhuman primate model for malaria vaccine development allowing reliable, stringent sporozoite challenge and evaluation of both cellular and antibody responses is needed. We therefore constructed a multicomponent, multistage DNA vaccine for the simian malaria species Plasmodium knowlesi including two preerythrocytic-stage antigens, the circumsporozoite protein (PkCSP) and sporozoite surface protein 2 (PkSSP2), and two blood stage antigens, apical merozoite antigen 1 (PkAMA1) and merozoite surface protein 1 (PkMSP1p42), as well as recombinant canarypox viruses encoding the four antigens (ALVAC-4). The DNA vaccine plasmids expressed the corresponding antigens in vitro and induced antiparasite antibodies in mice. Groups of four rhesus monkeys received three doses of a mixture of the four DNA vaccine plasmids and a plasmid encoding rhesus granulocyte-monocyte colony-stimulating factor, followed by boosting with a single dose of ALVAC-4. Three groups received the priming DNA doses by different routes, either by intramuscular needle injection, by intramuscular injection with a needleless injection device, the Biojector, or by a combination of intramuscular and intradermal routes by Biojector. Animals immunized by any route developed antibody responses against sporozoites and infected erythrocytes and against a recombinant PkCSP protein, as well as gamma interferon-secreting T-cell responses against peptides from PkCSP. Following challenge with 100 P. knowlesi sporozoites, 1 of 12 experimental monkeys was completely protected and the mean parasitemia in the remaining monkeys was significantly lower than that in 4 control monkeys. This model will be important in preclinical vaccine development.

Cigarette smoke, asbestos, and small irregular opacities

The long-term inhalation of cigarette smoke is associated with the appearance of diffuse small irregular opacities of mild profusion on chest roentogenograms of some subjects in a limited number of reports. Human histologic and experimental animal studies have shown the presence of pulmonary interstitial fibrosis. The radiographic abnormalities may be explained by interstitial fibrosis, although bronchiolar wall thickening may also be involved. Because asbestos causes diffuse pulmonary fibrosis, the literature was reviewed for evidence concerning an interaction between cigarette smoke and asbestos in the frequency of pulmonary asbestosis. A majority of 14 prevalence studies and 7 cohort studies of asbestos workers with information on smoking habits have shown a positive interaction between the 2 agents. The interaction appears to be additive rather than synergistic. Smoking may exert an effect on the frequency of pulmonary asbestosis by increasing the effective fiber dose retained in the lungs through interference with clearance.

Identification and characterization of wheat grain albumin/globulin allergens

Bakers' asthma, an immediate-type allergic response to the inhalation of cereal flours, is an important occupational disease among workers of the baking and milling industries, and the salt-soluble proteins of wheat and rye flour dust are considered the most relevant allergens. In order to identify and characterize the major IgE-binding proteins, the polypeptide composition of the albumin/globulin protein fraction obtained from different cultivars was analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), and high-resolution two-dimensional polyacrylamide gel electrophoresis with immobilized pH gradients in the first dimension (IPG-Dalt), followed by immunoblotting with sera from asthmatic bakers. Relevant allergens were isolated by micropreparative IPG-Dalt and blotting onto polyvinylidenedifluoride membranes and identified by amino acid composition analysis or N-terminal amino acid sequence analysis. SDS-PAGE, IPG-Dalt, and immunoblotting demonstrated that the sera of the bakers allergic to flour contained IgE antibodies which bound to numerous albumin/globulin polypeptides in the 70, 55, 35, 26-28, and 14-18 kDa areas. More detailed investigations using IPG-Dalt revealed cultivar-specific differences in IgE-binding. It was also demonstrated that the majority of the allergens were not single polypeptide spots, but consisted of up to ten isoforms of similar molecular mass but different isoelectric points. Amino acid composition analysis and N-terminal amino acid sequence analysis, which were performed for nine allergens located in the 14-18, 26-28, and 35 kDa areas, revealed homologies to amylase/protease inhibitors, acyl-CoA oxidase and fructose-bisphosphate-aldolase from wheat, barley, maize, and rice, respectively.

Clinical trial: Preliminary efficacy and safety study of a new Budesonide-MMX® 9 mg extended-release tablets in patients with active left-sided ulcerative colitis

BACKGROUND

Ulcerative colitis (UC) is a chronic inflammatory disease with relapses. Many patients need systemic corticosteroids to induce clinical remission.

AIM

Efficacy and safety of Budesonide-MMX® 9 mg tablets, a new oral, extended-release formulation, were evaluated in patients suffering from active, left-sided UC with colitis activity index (CAI) <14.

METHODS

36 patients were treated once daily for 4 weeks with Budesonide-MMX® 9 mg tablets or placebo. In an additional 4-week period, all patients received Budesonide-MMX®. CAI, endoscopic index and histology were assessed after 4 and 8 weeks. Primary end-point was remission, and/or CAI reduction by 50% after 4 weeks. Morning cortisol was assayed after 4 and 8 weeks, and a short ACTH-test was performed at week 8.

RESULTS

32 patients were analysed. After 4 weeks, 47.1% of the patients in the Budesonide-MMX® 9 mg tablets group achieved the primary end-point vs. 33.3% of patients on placebo. In addition, 47.1% of budesonide patients and another 33.3% of placebo recipients improved without remission by 4 weeks. The CAI reduction was significant with Budesonide (p<0.0001) tablets and not with placebo (p=0.1). Neither morning cortisol nor pituitary-adrenal axis was more frequently suppressed with Budesonide tablets than with placebo.

CONCLUSIONS

Budesonide-MMX® 9 mg tablets induced a fast and significant clinical improvement of active left-sided UC without suppression of adrenocortical functions and without important toxicity EudraCT number 2004-000896-33.

Asbestosis: a marker for the increased risk of lung cancer among workers exposed to asbestos

This review examines the hypothesis that excess lung cancer risk in worker cohorts exposed to asbestos occurs only among those with asbestosis. The adequately designed studies in the literature support this hypothesis. The summary relative risk for lung cancer was 1.00 in seven cohorts with no deaths from asbestosis. In addition, there is a high correlation between asbestosis rates and lung cancer rates in 38 cohorts in contrast to a poor correlation between cumulative exposure data and lung cancer relative risks in eight cohorts with adequate data. The evidence indicates that asbestosis is a much better predictor of excess lung cancer risk than measures of exposure and serves as a marker for attributable cases.

Two-dimensional polyacrylamide gel electrophoresis, with immobilized pH gradients in the first dimension, of barley seed proteins: discrimination of cultivars with different malting grades

The suitability of high-resolution two-dimensional gel electrophoresis for barley cultivar discrimination and for classification with respect to their malting properties was studied. Seed proteins of 14 barley cultivars with different malting qualities were extracted with urea/dithiothreitol/Nonidet P-40 buffer and subjected to two-dimensional gel electrophoresis with immobilized pH gradients in the first dimension (IPG-DALT). The results of IPG-DALT were compared to the protein patterns obtained by a standard technique, sodium dodecyl sulfate polyacrylamide gel electrophoresis of hordeins. Sodium dodecyl sulfate-gel electrophoresis yielded seven different "B" and four different "C" hordein patterns; "A" and "D" hordein patterns were uniform in all cultivars tested. Four cultivars could be distinguished unequivocally, the others were classified into three groups containing between two and five cultivars. In contrast to these findings. IPG-DALT yielded three different "A", eight different "B", four different "C" and two different "D" hordein patterns. When the "A", "B", "C" and "D" hordein patterns were combined, ten cultivars exhibited unique hordein patterns whereas the remaining ones were classified into two groups containing two cultivars each. Moreover, when albumin and globulin proteins were used for evaluation in addition to the hordeins, all cultivars could be discriminated by IPG-DALT. IPG-DALT, performed on small-scale and/or ready-made gels, proved to be an ideal complementary system to one-dimensional electrophoretic methods for routine seed testing purposes because of its speed, reliability, and simplicity. IPG-DALT was also applied to study the relationship between the different polypeptide patterns and the malting quality. Although cultivars with identical one-dimensional protein patterns but different malting quality could be successfully differentiated by IPG-DALT, a direct correlation between specific protein spots or protein patterns to the malting quality was not found within the cultivars tested.