Diffusion Characteristics of Human Plasminogen(as Shown by Two Agar Diffusion Techniques)

The relative diffusion rates of human plasminogen in agar has been compared with immune rabbit γ globulin and with streptokinase. A ratio of 1.1106 was found for plasminogen/immune rabbit γ globulin diffusion and a ratio of 0.80 for plasminogen/ streptokinase. These values were unaltered when plasminogen in normal fresh plasma and serum was replaced by three differently prepared plasminogen concentrates. Taking the D20 value for rabbit γ globulin as 4.23 × 10–7 cm2 sec−1 and for streptokinase the value of 6.1 × 10–7 cm2 sec–1, the corresponding values for human plasminogen were 4.7 and 4.9 × 10–7 cm2 sec–1. The widely divergent D20 values for human plasminogen and plasmin in the literature are reviewed and discussed.

Primary mass casualty incident triage: evidence for the benefit of yearly brief re-training from a simulation study

Background

Triage is a mainstay of early mass casualty incident (MCI) management. Standardized triage protocols aim at providing valid and reproducible results and, thus, improve triage quality. To date, there is little data supporting the extent and content of training and re-training on using such triage protocols within the Emergency Medical Services (EMS). The study objective was to assess the decline in triage skills indicating a minimum time interval for re-training. In addition, the effect of a one-hour repeating lesson on triage quality was analyzed.

Methods

A dummy based trial on primary MCI triage with yearly follow-up after initial training using the ASAV algorithm (Amberg-Schwandorf Algorithm for Primary Triage) was undertaken. Triage was assessed concerning accuracy, sensitivity, specificity, over-triage, under-triage, time requirement, and a comprehensive performance measure. A subgroup analysis of professional paramedics was made.

Results

Nine hundred ninety triage procedures performed by 51 providers were analyzed. At 1 year after initial training, triage accuracy and overall performance dropped significantly. Professional paramedic’s rate of correctly assigned triage categories deteriorated from 84 to 71%, and the overall performance score decreased from 95 to 90 points (maximum = 100). The observed decline in triage performance at 1 year after education made it necessary to conduct re-training. A brief didactic lecture of 45 min duration increased accuracy to 88% and the overall performance measure to 97.

Conclusions

To improve disaster preparedness, triage skills should be refreshed yearly by a brief re-education of all EMS providers.

Alpha galactosidase A activity in Parkinson's disease

Glucocerebrosidase (GCase, deficient in Gaucher disease) enzymatic activity measured in dried blood spots of Parkinson's Disease (PD) cases is within healthy range but reduced compared to controls. It is not known whether activities of additional lysosomal enzymes are reduced in dried blood spots in PD. To test whether reduction in lysosomal enzymatic activity in PD is specific to GCase, we measured GCase, acid sphingomyelinase (deficient in Niemann-Pick disease types A and B), alpha galactosidase A (deficient in Fabry), acid alpha-glucosidase (deficient in Pompe) and galactosylceramidase (deficient in Krabbe) enzymatic activities in dried blood spots of PD patients (n = 648) and controls (n = 317) recruited from Columbia University. Full sequencing of glucocerebrosidase (GBA) and the LRRK2 G2019S mutation was performed. Enzymatic activities were compared between PD cases and controls using t-test and regression models adjusted for age, gender, and GBA and LRRK2 G2019S mutation status. Alpha galactosidase A activity was lower in PD cases compared to controls both when only non-carriers were included (excluding all GBA and LRRK2 G2019S carriers and PD cases with age-at-onset below 40) [2.85 μmol/l/h versus 3.12 μmol/l/h, p = 0.018; after controlling for batch effect, p = 0.006 (468 PD cases and 296 controls)], and when including the entire cohort (2.89 μmol/l/h versus 3.10 μmol/l/h, p = 0.040; after controlling for batch effect, p = 0.011). Because the alpha galactosidase A gene is X-linked, we stratified the analyses by sex. Among women who were non-carriers of GBA and LRRK2 G2019S mutations (PD, n = 155; control, n = 194), alpha galactosidase A activity was lower in PD compared to controls (2.77 μmol/l/h versus 3.10 μmol/l/h, p = 0.044; after controlling for a batch effect, p = 0.001). The enzymatic activity of acid sphingomyelinase, acid alpha-glucosidase and galactosylceramidase was not significantly different between PD and controls. In non-carriers, most lysosomal enzyme activities were correlated, with the strongest association in GCase, acid alpha-glucosidase, and alpha galactosidase A (Pearson correlation coefficient between 0.382 and 0.532). In a regression model with all five enzymes among non-carriers (adjusted for sex and age), higher alpha galactosidase A activity was associated with lower odds of PD status (OR = 0.54; 95% CI:0.31-0.95; p = 0.032). When LRRK2 G2019S PD carriers (n = 37) were compared to non-carriers with PD, carriers had higher GCase, acid sphingomyelinase and alpha galactosidase A activity. We conclude that alpha galactosidase A may have a potential independent role in PD, in addition to GCase.

When monoclonal antibodies are not monospecific: Hybridomas frequently express additional functional variable regions

Monoclonal antibodies are commonly assumed to be monospecific, but anecdotal studies have reported genetic diversity in antibody heavy chain and light chain genes found within individual hybridomas. As the prevalence of such diversity has never been explored, we analyzed 185 random hybridomas, in a large multicenter dataset. The hybridomas analyzed were not biased towards those with cloning difficulties or known to have additional chains. Of the hybridomas we evaluated, 126 (68.1%) contained no additional productive chains, while the remaining 59 (31.9%) contained one or more additional productive heavy or light chains. The expression of additional chains degraded properties of the antibodies, including specificity, binding signal and/or signal-to-noise ratio, as determined by enzyme-linked immunosorbent assay and immunohistochemistry. The most abundant mRNA transcripts found in a hybridoma cell line did not necessarily encode the antibody chains providing the correct specificity. Consequently, when cloning antibody genes, functional validation of all possible VH and VL combinations is required to identify those with the highest affinity and lowest cross-reactivity. These findings, reflecting the current state of hybridomas used in research, reiterate the importance of using sequence-defined recombinant antibodies for research or diagnostic use.

Time-Resolved Tracking of Separately Internalized Neuropeptide Y2 Receptors by Two-Color Pulse-Chase

Internalization and intracellular trafficking of G protein-coupled receptors (GPCR) plays an important role in the signal transduction. These processes are often highly dynamic and take place rapidly. In the past 10 years, it became obvious that internalized GPCRs are also capable of signaling via arrestin or heterotrimeric G proteins within the endosomal compartment. Real-time imaging of receptors in living cells can help to evaluate the temporal and spatial localization. We achieved a two-color pulse-chase labeling approach, which allowed the tracking of the human neuropeptide Y₂ receptor (hY₂R) in the same cell at different times. The ability to visualize the internalization pathway of two separately labeled and separately stimulated subsets of hY₂R in a time-resolved manner revealed a rapid trafficking. Fusion of the two hY₂R subsets was already observed 10 min after stimulation in the early endosomal compartment without subsequent separation of the fused receptor populations. The results demonstrate that the cells do not discriminate between receptors that were stimulated and internalized at different time points.

Impact of Methadone on Cisplatin Treatment of Bladder Cancer Cells

BACKGROUND

Cisplatin-based chemotherapy is the treatment of choice for advanced bladder cancer. Since many tumor cells show inherent or acquired cisplatin resistance, research is needed to improve the therapeutic efficacy. Since the analgesic methadone is discussed as being a sensitizer for chemotherapy, we tested its effects on the cisplatin treatment of bladder cancer cells.

MATERIALS AND METHODS

T24 and HT-1376 bladder cancer cells were incubated with cisplatin in combination with methadone. Cytotoxicity was examined using the WST-1 viability assay and induction of apoptosis was analyzed via phase-contrast microscopy, flow cytometry, and western blot analysis.

RESULTS

Methadone was shown to enhance the cytotoxic effects of cisplatin on T24 cells based on the induction of apoptosis. In contrast, HT-1376 cells were identified as non-responders to methadone.

CONCLUSION

Methadone could act as a chemosensitizer in the future treatment of advanced bladder cancer. Further research is needed to identify the underlying molecular mechanisms.

Synergistic cytotoxicity of a prostate cancer-specific immunotoxin in combination with the BH3 mimetic ABT-737

In many tumors, including prostate cancer, anti-apoptotic members of the Bcl-2 family are overexpressed and cause cell death resistance, which is a typical hallmark of cancer. Different therapeutic approaches, therefore, aim to restore the death mechanisms for enhanced apoptosis. Our recombinant immunotoxin D7(VL-VH)-PE40 is composed of the scFv D7(VL-VH) against the prostate-specific membrane antigen (PSMA) on the surface of prostate cancer cells and of the cytotoxic domain of the bacterial toxin Pseudomonas Exotoxin A (PE40). Since Pseudomonas Exotoxin A-based immunotoxins are known to preferentially inhibit the expression of the anti-apoptotic protein Mcl-1, the rationale was to test our immunotoxin in combination with the BH3 mimetic ABT-737, which specifically inhibits Bcl-2, Bcl-xl, and Bcl-w for enhanced induction of apoptosis in prostate cancer cells. The immunotoxin showed high and specific binding and cytotoxicity against PSMA expressing prostate cancer cells marked by a direct inhibition of Mcl-1. The combination of the immunotoxin with a subtoxic concentration of ABT-737 caused additive or even synergistic effects, which were based on an enhanced apoptosis induction as detected by poly(ADP-ribose) polymerase (PARP) and Caspase-3 cleavage in Western blot. Our study shows that the combination therapy of immunotoxin plus ABT-737 is a promising approach for the future treatment of advanced prostate cancer to improve therapeutic efficacy and to reduce adverse side effects.

Lorentz-symmetry test at Planck-scale suppression with a spin-polarized 133 Cs cold atom clock

We present the results of a Local Lorentz Invariance (LLI) test performed with the 133Cs cold atom clock FO2 [1], hosted at SYRTE. Such test, relating the frequency shift between 133Cs hyperfine Zeeman substates to the Lorentz violating coefficients of the Standard Model Extension (SME), has already been realized in [2] and led to state-of-the-art constraints on several SME proton coefficients. In this second analysis we used an improved model, based on a second order Lorentz transformation and a SCRMF nuclear model, which enables us to extend the scope of the analysis from purely proton to both proton and neutron coefficients. We have also become sensitive to the isotropic coefficient ~cTT, another SME coefficient that was not constrained in [2]. The resulting limits on SME coefficients improve by up to 13 orders of magnitude the present maximal sensitivities for laboratory tests and reach the generally expected suppression scales at which signatures of Lorentz violation could appear [3].

In Vitro Evaluation of Humanized/De-immunized Anti-PSMA Immunotoxins for the Treatment of Prostate Cancer

BACKGROUND

We generated humanized/de-immunized immunotoxins targeting the prostate-specific membrane antigen (PSMA) and tested their cytotoxic activity against prostate cancer cells in vitro.

MATERIALS AND METHODS

The humanized/de-immunized version of our murine anti-PSMA single-chain antibody fragment (scFv) D7, termed hD7-1(VL-VH), was ligated to the 40-kDa toxin domain of Pseudomonas aeruginosa exotoxin A (PE40), and to the deimmunized 24-kDa toxin domains PE24 or PE24mut. The immunotoxins designated as hD7-1(VL-VH)-PE40, hD7-1(VL-VH)-PE24 and hD7-1(VL-VH)-PE24mut were bacterially expressed and purified by affinity chromatography. Binding and cytotoxicity were examined by flow cytometry and viability assay, respectively.

RESULTS

All immunotoxins revealed strong binding to prostate cancer cells expressing PSMA and specific cytotoxicity, with half-maximal inhibitory concentration values in the picomolar range.

CONCLUSION

We successfully created powerful anti-PSMA immunotoxins with reduced immunogenicity for further clinical development and application against advanced prostate cancer.

Metabolic engineering of Pichia pastoris for production of isobutanol and isobutyl acetate

BACKGROUND

Interests in renewable fuels have exploded in recent years as the serious effects of global climate change become apparent. Microbial production of high-energy fuels by economically efficient bioprocesses has emerged as an attractive alternative to the traditional production of transportation fuels. Here, we engineered Pichia pastoris, an industrial workhorse in heterologous enzyme production, to produce the biofuel isobutanol from two renewable carbon sources, glucose and glycerol. Our strategy exploited the yeast's amino acid biosynthetic pathway and diverted the amino acid intermediates to the 2-keto acid degradation pathway for higher alcohol production. To further demonstrate the versatility of our yeast platform, we incorporated a broad-substrate-range alcohol-O-acyltransferase to generate a variety of volatile esters, including isobutyl acetate ester and isopentyl acetate ester.

RESULTS

The engineered strain overexpressing the keto-acid degradation pathway was able to produce 284 mg/L of isobutanol when supplemented with 2-ketoisovalerate. To improve the production of isobutanol and eliminate the need to supplement the production media with the expensive 2-ketoisovalerate intermediate, we overexpressed a portion of the amino acid l-valine biosynthetic pathway in the engineered strain. While heterologous expression of the pathway genes from the yeast Saccharomyces cerevisiae did not lead to improvement in isobutanol production in the engineered P. pastoris, overexpression of the endogenous l-valine biosynthetic pathway genes led to a strain that is able to produce 0.89 g/L of isobutanol. Fine-tuning the expression of bottleneck enzymes by employing an episomal plasmid-based expression system further improved the production titer of isobutanol to 2.22 g/L, a 43-fold improvement from the levels observed in the original strain. Finally, heterologous expression of a broad-substrate-range alcohol-O-acyltransferase led to the production of isobutyl acetate ester and isopentyl acetate ester at 51 and 24 mg/L, respectively.

CONCLUSIONS

In this study, we engineered high-level production of the biofuel isobutanol and the corresponding acetate ester by P. pastoris from readily available carbon sources. We envision that our work will provide an economic route to this important class of compounds and establish P. pastoris as a versatile production platform for fuels and chemicals.

In vitro and in vivo effects of a recombinant anti-PSMA immunotoxin in combination with docetaxel against prostate cancer

Docetaxel (DOC) is used for the first-line treatment of castration resistant prostate cancer (CPRC). However, the therapeutic effects are limited, only about one half of patients respond to the therapy and severe side effects possibly lead to discontinuation of treatment. Therefore, actual research is focused on the development of new DOC-based combination treatments.

In this study we investigated the antitumor effects of a recombinant immunotoxin targeting the prostate specific membrane antigen (PSMA) in combination with DOC in vitro and in vivo. The immunotoxin consists of an anti-PSMA single chain antibody fragment (scFv) as binding and a truncated form of Pseudomonas aeruginosa Exotoxin A (PE40) as toxin domain. The immunotoxin induced apoptosis and specifically reduced the viability of androgen-dependent LNCaP and androgen-independent C4-2 prostate cancer cells. A synergistic cytotoxic activity was observed in combination with DOC with IC₅₀ values in the low picomolar or even femtomolar range. Moreover, combination treatment resulted in an enhanced antitumor activity in a C4-2 SCID mouse xenograft model. This highlights the immunotoxin as a promising therapeutic agent for a future DOC-based combination therapy of CPRC.

Methadone as a "Tumor Theralgesic" against Cancer

Methadone has beneficial characteristics as an analgesic against cancer pain, including high bioavailability, multiple receptor affinities, and lack of active metabolites that might induce adverse side effects. However, methadone has an own pharmacological profile that should be considered in the treatment of cancer patients. There is evidence from preclinical studies that methadone could also elicit antitumor activity by downregulating the threshold of apoptosis and to enhance the effects of different chemotherapeutic agents. This confirms the concept of using methadone as a chemosensitizer in the future treatment of cancer. Our article discusses major issues about the role of methadone as a possible “tumor theralgesic,” combining tumor therapeutic and analgesic activities.