Three-Dimensional Trapping of Individual Rydberg Atoms in Ponderomotive Bottle Beam Traps

We demonstrate three-dimensional trapping of individual Rydberg atoms in holographic optical bottle beam traps. Starting with cold, ground-state ^{87}Rb atoms held in standard optical tweezers, we excite them to nS_{1/2}, nP_{1/2}, or nD_{3/2} Rydberg states and transfer them to a hollow trap at 850 nm. For principal quantum numbers 60≤n≤90, the measured trapping time coincides with the Rydberg state lifetime in a 300 K environment. We show that these traps are compatible with quantum information and simulation tasks by performing single qubit microwave Rabi flopping, as well as by measuring the interaction-induced, coherent spin-exchange dynamics between two trapped Rydberg atoms separated by 40  μm. These results will find applications in the realization of high-fidelity quantum simulations and quantum logic operations with Rydberg atoms.

Clinical profile of the functionally selective glucocorticoid receptor agonist BI 653048 in healthy male subjects

BACKGROUND

An efficacious anti-inflammatory corticosteroid with reduced side effects has been long sought. We report the pooled results from three clinical proof-of-mechanism Phase I studies of BI 653048 in healthy subjects, a functionally selective, nonsteroidal glucocorticoid (GC).

RESEARCH DESIGN AND METHODS

Three Phase I trials were conducted: a single rising-dose study and a multiple rising-dose study to evaluate the safety, tolerability, and pharmacokinetics of BI 653048, and a multiple parallel-arm-dose study with intravenous lipopolysaccharide challenge to assess in vivo pharmacodynamics. The pharmacodynamics, efficacy, and safety of BI 653048 and prednisolone were compared.

RESULTS

Treatment with 200 mg BI 653048 was associated with a reduced expression of IL1R2, ITGB3, and SDPR versus 20 mg prednisolone; comparable levels of FKBP5, ZBTB16, and DDIT4 expression were observed. Changes in C-peptide, glucose, insulin, and cortisol were moderate compared with prednisolone. A greater reduction of osteocalcin was observed with 200 mg BI 653048 versus 20 mg prednisolone. Comparable anti-inflammatory efficacy was demonstrated for 200 mg BI 653048 and 20 mg prednisolone. BI 653048 was well tolerated in healthy subjects.

CONCLUSION

BI 653048 demonstrated the desired anti-inflammatory effects of the nonsteroidal GC; however, the undesirable side-effect profile associated with GC steroids could not be disassociated from BI 653048.

TRIAL REGISTRATION

ClinicalTrials.gov identifiers NCT02217644, NCT02217631, and NCT02224105.

Risankizumab, an IL-23 inhibitor, for ankylosing spondylitis: results of a randomised, double-blind, placebo-controlled, proof-of-concept, dose-finding phase 2 study

Objectives

To evaluate the efficacy and safety of risankizumab, a humanised monoclonal antibody targeting the p19 subunit of interleukin-23 (IL-23), in patients with active ankylosing spondylitis (AS).

Methods

A total of 159 patients with biological-naïve AS, with active disease (Bath Ankylosing Spondylitis Disease Activity Index score of ≥4), were randomised (1:1:1:1) to risankizumab (18 mg single dose, 90 mg or 180 mg at day 1 and weeks 8, 16 and 24) or placebo over a 24-week blinded period. The primary outcome was a 40% improvement in Assessment in Spondylo Arthritis International Society (ASAS40) at week 12. Safety was assessed in patients who received at least one dose of study drug.

Results

At week 12, ASAS40 response rates were 25.5%, 20.5% and 15.0% in the 18 mg, 90 mg and 180 mg risankizumab groups, respectively, compared with 17.5% in the placebo group. The estimated difference in proportion between the 180 mg risankizumab and placebo groups (primary endpoint) was –2.5% (95% CI –21.8 to 17.0; p=0.42). Rates of adverse events were similar in all treatment groups.

Conclusions

Treatment with risankizumab did not meet the study primary endpoint and showed no evidence of clinically meaningful improvements compared with placebo in patients with active AS, suggesting that IL-23 may not be a relevant driver of disease pathogenesis and symptoms in AS.

Trial registration number

NCT02047110; Pre-results.

Induction therapy with the selective interleukin-23 inhibitor risankizumab in patients with moderate-to-severe Crohn's disease: a randomised, double-blind, placebo-controlled phase 2 study

BACKGROUND

The interleukin-23 pathway is implicated genetically and biologically in the pathogenesis of Crohn's disease. We aimed to assess the efficacy and safety of risankizumab (BI 655066, Boehringer Ingelheim, Ingelheim, Germany), a humanised monoclonal antibody targeting the p19 subunit of interleukin-23, in patients with moderately-to-severely active Crohn's disease.

METHODS

In this randomised, double-blind, placebo-controlled phase 2 study, we enrolled patients at 36 referral sites in North America, Europe, and southeast Asia. Eligible patients were aged 18-75 years, with a diagnosis of Crohn's disease for at least 3 months, assessed as moderate-to-severe Crohn's disease at screening, defined as a Crohn's Disease Activity Index (CDAI) of 220-450, with mucosal ulcers in the ileum or colon, or both, and a Crohn's Disease Endoscopic Index of Severity (CDEIS) of at least 7 (≥4 for patients with isolated ileitis) on ileocolonoscopy scored by a masked central reader. Patients were randomised 1:1:1 using an interactive response system to a double-blind investigational product, and stratified by previous exposure to TNF antagonists (yes vs no). Patients received intravenous 200 mg risankizumab, 600 mg risankizumab, or placebo, at weeks 0, 4, and 8. The primary outcome was clinical remission (CDAI <150) at week 12 (intention-to-treat population). Safety was assessed in patients who received at least one dose of study drug. This study is registered with ClinicalTrials.gov, number NCT02031276.

FINDINGS

Between March, 2014, and September, 2015, 213 patients were screened, and 121 patients randomised. At baseline, 113 patients (93%) had been previously treated with at least one tumour necrosis factor (TNF) antagonist (which had failed in 96 [79%]). At week 12, 25 (31%) of 82 risankizumab patients (pooled 41 patients in 200 mg and 41 patients in 600 mg arms) had clinical remission versus six (15%) of 39 placebo patients (difference vs placebo 15·0%, 95% CI 0·1 to 30·1; p=0·0489). Ten (24%) of 41 patients who received 200 mg risankizumab had clinical remission (9·0%, -8·3 to 26·2; p=0·31) and 15 (37%) of 41 who received the 600 mg dose (20·9%, 2·6 to 39·2; p=0·0252). 95 (79%) patients had adverse events (32 in the placebo group, 32 randomised to 200 mg risankizumab, 31 randomised to 600 mg risankizumab); 18 had severe adverse events (nine, six, three); 12 discontinued (six, five, one); 24 had serious adverse events (12, nine, three). The most common adverse event was nausea and most common serious adverse event was worsening of underlying Crohn's disease. No deaths occurred.

INTERPRETATION

In this short-term study, risankizumab was more effective than placebo for inducing clinical remission in patients with active Crohn's disease. Therefore, selective blockade of interleukin-23 via inhibition of p19 might be a viable therapeutic approach in Crohn's disease.

FUNDING

Boehringer Ingelheim.

Risankizumab versus Ustekinumab for Moderate-to-Severe Plaque Psoriasis

BACKGROUND

Interleukin-23 is thought to be critical to the pathogenesis of psoriasis. We compared risankizumab (BI 655066), a humanized IgG1 monoclonal antibody that inhibits interleukin-23 by specifically targeting the p19 subunit and thus prevents interleukin-23 signaling, and ustekinumab, an interleukin-12 and interleukin-23 inhibitor, in patients with moderate-to-severe plaque psoriasis.

METHODS

We randomly assigned a total of 166 patients to receive subcutaneous injections of risankizumab (a single 18-mg dose at week 0 or 90-mg or 180-mg doses at weeks 0, 4, and 16) or ustekinumab (45 or 90 mg, according to body weight, at weeks 0, 4, and 16). The primary end point was a 90% or greater reduction from baseline in the Psoriasis Area and Severity Index (PASI) score at week 12.

RESULTS

At week 12, the percentage of patients with a 90% or greater reduction in the PASI score was 77% (64 of 83 patients) for risankizumab (90-mg and 180-mg groups, pooled), as compared with 40% (16 of 40 patients) for ustekinumab (P<0.001); the percentage of patients with a 100% reduction in the PASI score was 45% in the pooled 90-mg and 180-mg risankizumab groups, as compared with 18% in the ustekinumab group. Efficacy was generally maintained up to 20 weeks after the final dose of 90 or 180 mg of risankizumab. In the 18-mg and 90-mg risankizumab groups and the ustekinumab group, 5 patients (12%), 6 patients (15%), and 3 patients (8%), respectively, had serious adverse events, including two basal-cell carcinomas and one major cardiovascular adverse event; there were no serious adverse events in the 180-mg risankizumab group.

CONCLUSIONS

In this phase 2 trial, selective blockade of interleukin-23 with risankizumab was associated with clinical responses superior to those associated with ustekinumab. This trial was not large enough or of long enough duration to draw conclusions about safety. (Funded by Boehringer Ingelheim; ClinicalTrials.gov number, NCT02054481 ).

L-System model for the growth of arbuscular mycorrhizal fungi, both within and outside of their host roots

Development of arbuscular mycorrhizal fungal colonization of roots and the surrounding soil is the central process of mycorrhizal symbiosis, important for ecosystem functioning and commercial inoculum applications. To improve mechanistic understanding of this highly spatially and temporarily dynamic process, we developed a three-dimensional model taking into account growth of the roots and hyphae. It is for the first time that infection within the root system is simulated dynamically and in a spatially resolved way. Comparison between data measured in a calibration experiment and simulated results showed a good fit. Our simulations showed that the position of the fungal inoculum affects the sensitivity of hyphal growth parameters. Variation in speed of secondary infection and hyphal lifetime had a different effect on root infection and hyphal length, respectively, depending on whether the inoculum was concentrated or dispersed. For other parameters (branching rate, distance between entry points), the relative effect was the same independent of inoculum placement. The model also indicated that maximum root colonization levels well below 100%, often observed experimentally, may be a result of differential spread of roots and hyphae, besides intrinsic plant control, particularly upon localized placement of inoculum and slow secondary infection.

Root induced changes of effective 1D hydraulic properties in a soil column

AIMS

Roots are essential drivers of soil structure and pore formation. This study aimed at quantifying root induced changes of the pore size distribution (PSD). The focus was on the extent of clogging vs. formation of pores during active root growth.

METHODS

Parameters of Kosugi's lognormal PSD model were determined by inverse estimation in a column experiment with two cover crops (mustard, rye) and an unplanted control. Pore dynamics were described using a convection-dispersion like pore evolution model.

RESULTS

Rooted treatments showed a wider range of pore radii with increasing volumes of large macropores >500 μm and micropores <2.5 μm, while fine macropores, mesopores and larger micropores decreased. The non-rooted control showed narrowing of the PSD and reduced porosity over all radius classes. The pore evolution model accurately described root induced changes, while structure degradation in the non-rooted control was not captured properly. Our study demonstrated significant short term root effects with heterogenization of the pore system as dominant process of root induced structure formation.

CONCLUSIONS

Pore clogging is suggested as a partial cause for reduced pore volume. The important change in micro- and large macropores however indicates that multiple mechanic and biochemical processes are involved in root-pore interactions.

Field quantification of wetting-drying cycles to predict temporal changes of soil pore size distribution

Wetting-drying (WD) cycles substantially influence structure related soil properties and processes. Most studies on WD effects are based on controlled cycles under laboratory conditions. Our objective was the quantification of WD cycles from field water content measurements and the analysis of their relation to the temporal drift in the soil pore size distribution. Parameters of the Kosugi hydraulic property model (r_m,Kosugi, σ_Kosugi) were derived by inverse optimization from tension infiltrometer measurements. Spectral analysis was used to calculate WD cycle intensity, number and duration from water content time series. WD cycle intensity was the best predictor (r² = 0.53-0.57) for the temporal drift in median pore radius (r_m,Kosugi) and pore radius standard deviation (σ_Kosugi). At lower soil moisture conditions the effect of cycle intensity was reduced. A bivariate regression model was derived with WD intensity and a meteorological indicator for drying periods (ET₀, climatic water balance deficit) as predictor variables. This model showed that WD enhanced macroporosity (higher r_m,Kosugi) while decreasing pore heterogeneity (lower σ_Kosugi). A drying period with high cumulative values of ET₀ or a strong climatic water balance deficit on the contrary reduced r_m,Kosugi while slightly increasing σ_Kosugi due to higher frequency at small pore radius classes. The two parameter regression model was applied to predict the time course of soil pore size distribution parameters. The observed system dynamics was captured substantially better by the calculated values compared to a static representation with averaged hydraulic parameters. The study showed that spectral analysis is an adequate approach for the quantification of field WD pattern and that WD intensity is a key factor for the temporal dynamics of the soil pore size distribution.

Environmental and management influences on temporal variability of near saturated soil hydraulic properties

Structural porosity is a decisive property for soil productivity and soil environmental functions. Hydraulic properties in the structural range vary over time in response to management and environmental influences. Although this is widely recognized, there are few field studies that determine dominant driving forces underlying hydraulic property dynamics. During a three year field experiment we measured temporal variability of soil hydraulic properties by tension infiltrometry. Soil properties were characterized by hydraulic conductivity, effective macroporosity and Kosugi's lognormal pore size distribution model. Management related influences comprised three soil cover treatment (mustard and rye vs. fallow) and an initial mechanical soil disturbance with a rotary harrow. Environmental driving forces were derived from meteorological and soil moisture data. Soil hydraulic parameters varied over time by around one order of magnitude. The coefficient of variation of soil hydraulic conductivity K(h) decreased from 69.5% at saturation to 42.1% in the more unsaturated range (- 10 cm pressure head). A slight increase in the Kosugi parameter showing pore heterogeneity was observed under the rye cover crop, reflecting an enhanced structural porosity. The other hydraulic parameters were not significantly influenced by the soil cover treatments. Seedbed preparation with a rotary harrow resulted in a fourfold increase in macroporosity and hydraulic conductivity next to saturation, and homogenized the pore radius distribution. Re-consolidation after mechanical loosening lasted over 18 months until the soil returned to its initial state. The post-tillage trend of soil settlement could be approximated by an exponential decay function. Among environmental factors, wetting-drying cycles were identified as dominant driving force explaining short term hydraulic property changes within the season (r² = 0.43 to 0.59). Our results suggested that beside considering average management induced changes in soil properties (e.g. cover crop introduction), a dynamic approach to hydrological modeling is required to capture over-seasonal (tillage driven) and short term (environmental driven) variability in hydraulic parameters.

Environmental and management influences on temporal variability of near saturated soil hydraulic properties

Structural porosity is a decisive property for soil productivity and soil environmental functions. Hydraulic properties in the structural range vary over time in response to management and environmental influences. Although this is widely recognized, there are few field studies that determine dominant driving forces underlying hydraulic property dynamics. During a three year field experiment we measured temporal variability of soil hydraulic properties by tension infiltrometry. Soil properties were characterized by hydraulic conductivity, effective macroporosity and Kosugi's lognormal pore size distribution model. Management related influences comprised three soil cover treatment (mustard and rye vs. fallow) and an initial mechanical soil disturbance with a rotary harrow. Environmental driving forces were derived from meteorological and soil moisture data. Soil hydraulic parameters varied over time by around one order of magnitude. The coefficient of variation of soil hydraulic conductivity K(h) decreased from 69.5% at saturation to 42.1% in the more unsaturated range (- 10 cm pressure head). A slight increase in the Kosugi parameter showing pore heterogeneity was observed under the rye cover crop, reflecting an enhanced structural porosity. The other hydraulic parameters were not significantly influenced by the soil cover treatments. Seedbed preparation with a rotary harrow resulted in a fourfold increase in macroporosity and hydraulic conductivity next to saturation, and homogenized the pore radius distribution. Re-consolidation after mechanical loosening lasted over 18 months until the soil returned to its initial state. The post-tillage trend of soil settlement could be approximated by an exponential decay function. Among environmental factors, wetting-drying cycles were identified as dominant driving force explaining short term hydraulic property changes within the season (r² = 0.43 to 0.59). Our results suggested that beside considering average management induced changes in soil properties (e.g. cover crop introduction), a dynamic approach to hydrological modeling is required to capture over-seasonal (tillage driven) and short term (environmental driven) variability in hydraulic parameters.

Nonmyeloablative hematopoietic stem cell transplant for X-linked hyper-immunoglobulin m syndrome with cholangiopathy

OBJECTIVE

X-linked hyper-immunoglobulin M (X-HIM) syndrome is a rare genetic immunodeficiency syndrome caused by mutations in the gene encoding CD40 ligand (CD40L, CD154). Allogeneic hematopoietic stem cell transplantation (HSCT) offers the prospect of immune reconstitution in X-HIM syndrome. Standard HSCT using high-dose chemoradiotherapy can be followed by serious hepatic problems, including veno-occlusive disease, graft-versus-host disease, and/or drug-induced hepatotoxicity. In patients whose liver function is compromised before HSCT, such as in X-HIM syndrome caused by cholangiopathy and hepatitis related to opportunistic infections, there is a higher likelihood of hepatotoxicity. We explored nonmyeloablative HSCT in 2 patients with X-HIM syndrome. Nonmyeloablative HSCT without liver transplant for X-HIM syndrome, to our knowledge, has not been described previously.

METHODS

Two children with X-HIM syndrome and persistent infections had documented cholangiopathy on liver biopsy. Both children underwent nonmyeloablative HSCT from HLA-matched siblings with fludarabine, busulfan, and anti-thymocyte globulin as their preparative regimen. Graft-versus-host disease prophylaxis consisted of cyclosporine.

RESULTS

Both children are >2 years after their HSCT. One remains a mixed chimera, and the other shows 100% donor chimerism. Both children are now free of infections and are no longer dependent on intravenous gammaglobulin. Both show response to immunizations. Both have had resolution of their cholangiopathy.

CONCLUSIONS

Nonmyeloablative HSCT from HLA-matched siblings can offer immune reconstitution without hepatotoxicity in patients with X-HIM syndrome and preexisting cholangiopathy. Even with stable mixed chimerism after allogeneic HSCT, patients may be able to enjoy a normal phenotype. Nonmyeloablative HSCT warrants additional study in X-HIM syndrome.

Detection of malaria parasites in blood by laser desorption mass spectrometry

A novel method for the in vitro detection of the protozoan Plasmodium, the causative agent of malaria, has been developed. It comprises a protocol for cleanup of whole blood samples, followed by direct ultraviolet laser desorption (LD) time-of-flight mass spectrometry. Intense ion signals are observed from intact ferriprotoporphyrin IX (heme), sequestered by malaria parasites during their growth in human red blood cells. The LD mass spectrum of the heme is structure-specific, and the signal intensities are correlated with the sample parasitemia (number of parasites per unit volume of blood). Parasitemia levels on the order of 10 parasites/microL blood can be unambiguously detected by this method. Consideration of laser beam parameters (spot size, rastering across the sample surface) and actual sample consumption suggests that the detection limits can be further improved by at least an order of magnitude. The influence of experimental factors, such as desorbed ion polarity, laser exposure and fluence, sample size, and parasite growth stage, on the threshold for parasite detection is also addressed.

Oestrus ovis in sheep: relative third-instar populations, risks of infection and parasitic control

Oestrus ovis (L.) (Diptera: Oestridae), the nasal bot fly, has a relatively short free-living life cycle outside of the host, and therefore it is necessary to know when the parasitic period occurs in order to prevent the clinical signs and economic losses caused by this parasite. The length of this parasitic portion of the life cycle is quite variable: a few weeks to several months depending on the season and climatic conditions. Surveys of Oestrus ovis larval populations in sheep show different results on the number of generations according to the local climate. Mean monthly larval profiles of L1 and L3 burdens of sheep from West African Sahelian countries, Mediterranean countries (Morocco, Tunisia and Sicily) and Southwest France were compared. Valuable information on the suspected extension of the fly season is obtained showing the period of infection in each area. This knowledge will be a valuable tool to help in choosing the right treatment at the right period.

Pyrimido[1,2-alpha]purin-10(3H)-one: a reactive electrophile in the genome

Malondialdehyde and base propenal react with deoxyguanosine residues in DNA to form an exocyclic adduct, pyrimido[1, 2-alpha]purin-10(3H)-one (1), that has been detected at high levels in genomic DNA of healthy humans. Previous studies have shown that tris(hydroxymethyl)aminomethane adds to 1 at elevated pH, forming an enaminoimine (2), but it is uncertain whether 1 reacts directly or hydrolyzes under basic conditions to N(2)-(3-oxo-1-propenyl)deoxyguanosine (3) prior to amine addition. We report that 1 reacts at neutral pH with hydroxylamines to form oximes. The rate of reaction of 1 with hydroxylamines at pH 7 is at least 150 times faster than the rate of hydrolysis of 1 to 3. Thus, 1 is directly reactive to nucleophiles. These observations indicate that 1 is an electrophile in the human genome that may react with cellular nucleophiles to form novel cross-linked adducts.

Molecular biomarkers for aflatoxins: from adducts to gene mutations to human liver cancer

Over the past 30 years there have been extensive efforts to investigate the association between aflatoxin exposure and human liver cancer. These studies have been hindered by the lack of adequate dosimetry data on aflatoxin intake, excretion, and metabolism in people, as well as by the general poor quality of worldwide cancer morbidity and mortality statistics. These realities have spurred the efforts to develop new technologies to assess exposure status and risk for aflatoxins, and these agents are among the few environmental carcinogens for which quantitative risk assessments have been attempted. One of the goals of these risk assessments has been the development of primary and secondary preventive intervention methods to lower the human health impact from aflatoxin exposures. The long-term goal of the research described herein is the application of biomarkers to the development of preventive interventions for use in human populations at high risk for cancer. Several of the aflatoxin-specific biomarkers have been validated in epidemiologic studies and are now available for use as intermediate biomarkers in prevention trials. The development of these aflatoxin biomarkers has been based upon the knowledge of the biochemistry and toxicology of aflatoxins gleaned from both experimental and human studies. These biomarkers have been utilized subsequently in experimental models to provide data on the modulation of the markers under different situations of disease risk. This systematic approach provides encouragement for preventive interventions and should serve as a template for the development for the development and validation of other chemical-specific biomarkers and their application to cancer or other chronic diseases.

Inhibition of aflatoxin Ml excretion in rat urine during dietary intervention with oltipraz

4-Methyl-5-(2-pyrazinyl)-1,2-dithiole-3-thione (oltipraz) is an effective chemopreventive agent against several classes of carcinogens in many target organs. Induction of carcinogen detoxication enzymes, particularly glutathione S-transferases, appears to be an important component of the protective actions of oltipraz. It has recently been observed that addition of oltipraz to rat liver microsomes or to cultured human hepatocytes blocks the oxidative metabolism of aflatoxin B1 (AFB1) to its 8,9-oxide and the hydroxylated derivative aflatoxin Ml (AFM1). 0ltipraz is a competitive and perhaps irreversible inhibitor of cytochromes P450 1A2 and 3A4. To determine whether oltipraz can affect cytochrome P450-dependent metabolism of AFB1 in vivo we have assessed the effect of oltipraz on the urinary excretion of oxidative metabolites of AFB1 before, during and after a transient intervention. Male F344 rats, housed individually in glass metabolism cages, were gavaged daily with 25 microg [3H]AFB1 for 28 consecutive days. Starting on day 6 and extending to day 16 half of the rats were fed a diet supplemented with 0.075% oltipraz. Sequential 24 h urine samples were collected and a subset analyzed for AFB1 metabolites. AFM1 was the major metabolite detected in all urine samples, accounting for 2-6% of the administered dose. The excretion of AFM1 was greatly reduced (77%) during the active phase of the intervention, when oltipraz was added to the diet, but rapidly returned to control levels after cessation of oltipraz administration. This inhibition of AFM1 excretion was not seen in animals receiving oltipraz by gavage 24 h prior to dosing with AFB1. Collectively these data are consistent with the view that oltipraz or a short-lived metabolite inhibits cytochrome P450 1A2 in vivo.

Molecular biomarkers for aflatoxins and their application to human liver cancer

The rationale for developing molecular biomarkers to monitor and assess risk from human exposure to aflatoxins have been justified by the association of these carcinogens with human liver cancer, a disease that causes at least 250000 deaths world-wide each year. The goal of our research has been the development of aflatoxin biomarkers based upon the knowledge of the biochemistry and toxicology of aflatoxins gleaned from both experimental and human studies. These biomarkers have been subsequently utilized in experimental chemoprotection models to provide data on the modulation of these markers under different situations of disease risk. Several of the aflatoxin specific biomarkers have been validated in epidemiologic studies and are now available to use as intermediate biomarkers in chemoprotection trials. This systematic approach provides encouragement for preventive interventions and should serve as a template for the development, validation and application of other chemical-specific biomarkers to cancer or other chronic diseases.

A toxic shock syndrome toxin-1 peptide that shows homology to mycobacterial heat shock protein 18 is presented as conventional antigen to T cells by multiple HLA-DR alleles

We observe that PBMC from most adults (16 of 18 subjects tested) show a small but significant in vitro proliferative response to a 30-amino acid-long peptide (peptide 2, amino acids 34-63) derived from toxic shock syndrome toxin. By contrast, PBMC from newborn blood and thymocytes do not proliferate to this peptide, and furthermore, peptide 2 did not displace the binding of radiolabeled TSST-1 to MHC class II positive cells, nor did it induce IL-1 beta mRNA in monocytes, indicating that this peptide does not behave as a superantigen. Proliferation of PBMC to peptide 2 could be blocked by anti-HLA-DR, but not by anti-HLA-DP or DQ mAb, suggesting that HLA-DR molecules are the restriction elements for the recognition of this peptide by T cells. This premise was further confirmed by demonstrating that mouse L cells transfected with human HLA-DR, but not HLA-DP or DQ molecules, supported the proliferation of purified T cells to peptide 2. Studies with subjects of known HLA-DR types showed that all types tested are capable of responding to this peptide, PBMC from adults exposed to mycobacterial Ag showed significantly better proliferative response to peptide 2 than unexposed adults. Studies with truncations of this peptide suggest that a "core" region of eight amino acids that is conserved between low m.w. heat shock proteins and peptide 2 may be critical to T cell recognition of this peptide. The universal presentation of peptide 2 by HLA-DR molecules may contribute to the widespread natural immunity observed against toxic shock syndrome toxin.

A toxic shock syndrome toxin-1 peptide that shows homology to mycobacterial heat shock protein 18 is presented as conventional antigen to T cells by multiple HLA-DR alleles

We observe that PBMC from most adults (16 of 18 subjects tested) show a small but significant in vitro proliferative response to a 30-amino acid-long peptide (peptide 2, amino acids 34-63) derived from toxic shock syndrome toxin. By contrast, PBMC from newborn blood and thymocytes do not proliferate to this peptide, and furthermore, peptide 2 did not displace the binding of radiolabeled TSST-1 to MHC class II positive cells, nor did it induce IL-1 beta mRNA in monocytes, indicating that this peptide does not behave as a superantigen. Proliferation of PBMC to peptide 2 could be blocked by anti-HLA-DR, but not by anti-HLA-DP or DQ mAb, suggesting that HLA-DR molecules are the restriction elements for the recognition of this peptide by T cells. This premise was further confirmed by demonstrating that mouse L cells transfected with human HLA-DR, but not HLA-DP or DQ molecules, supported the proliferation of purified T cells to peptide 2. Studies with subjects of known HLA-DR types showed that all types tested are capable of responding to this peptide, PBMC from adults exposed to mycobacterial Ag showed significantly better proliferative response to peptide 2 than unexposed adults. Studies with truncations of this peptide suggest that a "core" region of eight amino acids that is conserved between low m.w. heat shock proteins and peptide 2 may be critical to T cell recognition of this peptide. The universal presentation of peptide 2 by HLA-DR molecules may contribute to the widespread natural immunity observed against toxic shock syndrome toxin.

The CD4 molecule is not always required for the T cell response to bacterial enterotoxins

T cells respond in a V beta-restricted fashion to bacterial enterotoxins bound to major histocompatibility complex (MHC) class II molecules. The requirement for CD4 in MHC class II-restricted T cell responses is very well established. We have assessed the role of CD4 in the T cell response to the bacterial enterotoxins Staphylococcal enterotoxin A (SEA), SEB, and toxic shock syndrome toxin 1. Three CD4- murine T cell hybridomas were transfected with the human CD4 molecule and assayed for interleukin 2 production in the presence of accessory cells bearing human MHC class II molecules and of the appropriate enterotoxin. The results clearly indicate that CD4- cells responded even to suboptimal concentrations of enterotoxin(s) equally well as CD4+ cells. Furthermore, expression of CD4 did not result in the acquisition of previously undetectable reactivity to enterotoxins. These results suggest that unlike the case with antigen-specific responses, formation of a T cell receptor-CD3/CD4 supramolecular complex is not always essential for T cell activation by bacterial enterotoxins.

The alpha 1 domain of the HLA-DR molecule is essential for high-affinity binding of the toxic shock syndrome toxin-1

Several exoproteins from the bacterium Staphylococcus aureus are highly potent polyclonal activators of T cells in the presence of cells bearing class II antigens of the major histocompatibility complex (MHC). These toxins, including the toxic shock syndrome toxin (TSST-1), act at nanomolar concentrations, bind directly to class II molecules, and do not require the processing typical of nominal antigen. Each toxin is capable of stimulating a subpopulation of peripheral T lymphocytes bearing particular V beta sequences as part of their alpha beta T-cell receptors. It is not known how these so-called 'superantigens' bind to class II and how this binding stimulates T cells. In this study, the different affinities of TSST-1 for human class II molecules DR and DP were exploited to define the region of a class II molecule necessary for high-affinity binding. Using chimaeric alpha- and beta-chains of DR and DP expressed at the surface of transfected murine fibroblasts and a binding assay with TSST-1, it was shown that the alpha 1 domain of DR is essential for high-affinity binding, and further that TSST-1 binding did not prevent subsequent binding of a DR-restricted antigenic peptide. This is compatible with a model of superantigen making external contacts with both class II and T cell receptor, and suggests that the V beta portion of the T-cell receptor interacts with the nonpolymorphic alpha-chain of DR.

The staphylococcal toxic shock syndrome toxin 1 triggers B cell proliferation and differentiation via major histocompatibility complex-unrestricted cognate T/B cell interaction

The Staphylococcus aureus exotoxin toxic shock syndrome toxin 1 (TSST-1) is a potent activator of T cells and monocytes. We have recently demonstrated that TSST-1 is a superantigen that binds monomorphic determinants on MHC class II molecules. In the present study, we have examined the effect of TSST-1 on the activation and differentiation of high density human tonsillar B cells. TSST-1 bound to tonsilar B cells with high affinity and saturation kinetics. This binding was effectively inhibited by a combination of anti-HLA-DR and anti-HLA-DQ mAbs. Treatment of purified B cells with TSST-1 failed to induce B cell proliferation or Ig production. However, in the presence of irradiated T cells, TSST-1 induced resting B cells to proliferate and differentiate into Ig secretory cells. TSST-1 mimicked nominal antigen in that its induction of B cell responses was strictly dependent on physical contact between T and B cells, and was profoundly inhibited by anti-MHC class II mAbs, anti-CD3 mAbs, and, to a lesser extent, by anti-CD18 mAbs. However, unlike nominal antigen, TSST-1-mediated T/B cell interactions were MHC unrestricted. These results suggest that TSST-1 induces T cell-dependent B cell proliferation and differentiation by virtue of its ability to mediate MHC-unrestricted cognate T/B cell interaction via the TCR/CD3 complex and MHC class II antigens.

Toxic shock syndrome toxin 1 binds to major histocompatibility complex class II molecules

Toxic shock syndrome toxin 1 (TSST-1) is a 22-kDa exotoxin produced by strains of Staphylococcus aureus and implicated in the pathogenesis of toxic shock syndrome. In common with other staphylococcal exotoxins, TSST-1 has diverse immunological effects. These include the induction of interleukin 2 receptor expression, interleukin 2 synthesis, proliferation of human T lymphocytes, and stimulation of interleukin 1 synthesis by human monocytes. In the present study, we demonstrate that TSST-1 binds with saturation kinetics and with a dissociation constant of 17-43 nM to a single class of binding sites on human mononuclear cells. There was a strong correlation between the number of TSST-1 binding sites and the expression of major histocompatibility complex class II molecules, and interferon-gamma induced the expression of class II molecules as well as TSST-1 binding sites on human skin-derived fibroblasts. Monoclonal antibodies to HLA-DR, but not to HLA-DP or HLA-DQ, strongly inhibited TSST-1 binding. Affinity chromatography of 125I-labeled cell membranes over TSST-1-agarose resulted in the recovery of two bands of 35 kDa and 31 kDa that comigrated, respectively, with the alpha and beta chains of HLA-DR and that could be immunoprecipitated with anti-HLA-DR monoclonal antibodies. Binding of TSST-1 was demonstrated to HLA-DR and HLA-DQ L-cell transfectants. These results indicate that major histocompatibility complex class II molecules represent the major binding site for TSST-1 on human cells.

Microscopic cut-through of cancer in the surgical treatment of squamous carcinoma of the tongue. Prognostic and therapeutic implications

A retrospective review was carried out of the records of 268 patients with a pathologically proved diagnosis of squamous carcinoma of the tongue treated by glossectomy at M.D. Anderson Hospital and Tumor Institute from January 1, 1970 through December 31, 1979. Pathologic findings found on frozen section analysis were correlated with the TNM stage of the tumor, histologic characteristics, perineural invasion, type of treatment, local recurrence, and survival rate. Thirty-eight patients with squamous carcinoma of the oral tongue and 16 patients with tumors of the base of the tongue had initially positive frozen section margins. Forty-one of these patients had margins that were negative at the completion of surgery. Thirteen patients never had negative margins. Positive mucosal margins were more common in smaller tumors and positive muscular margins were more common in larger tumors. Patients with perineural invasion and larger tumors had a higher percentage of positive margins. Those patients with initially positive margins that were rendered negative at the completion of the procedure and treated with surgery only had a significantly increased local recurrence rate and reduced survival compared with patients similarly treated with initially negative margins. Tumor stage, location (muscular versus mucosal) of positive margins, and the presence of perineural invasion were not significant in predicting local recurrence or decreased survival. If all patients with microscopically positive margins are considered for postoperative radiotherapy, then the routine use of intraoperative frozen section examination of the margins of resection in squamous carcinoma of the tongue may not be justified.

Total ophthalmoplegia after internal maxillary artery ligation

Total ophthalmoplegia is a serious complication of internal maxillary artery ligation. Although serious complications of transantral surgery of the pterygopalatine space are rare, they remain a very real possibility and should be considered before undertaking arterial ligation for treatment of posterior epistaxis.

Controlled evaluation of fenbendazole as a bovine anthelmintic

Calves experimentally infected with Haemonchus, Ostertagia, and Cooperia, and to lesser degrees with Trichostrongylus, Oesophagostomum, Nematodirus, and Bunostomum were used in a controlled experiment to record the anthelmintic efficacy of a benzimidazole compound methyl 5-(phenylthio)-2-benzimidazolecarbamate at dosage levels of 3.5, 5, and 7.5 mg/kg bodyweight. With the 3 dosages, reductions of Haemonchus were 96.7, 99.2, and 99.8%; of Ostertagia, 97.2, 97.2, and 99.5%; and of Cooperia, 99.9, 99.9, and 99.9%. Pronounced reductions were also recorded for Trichostrongylus, Nematodirus, Oesophagostomum, Trichuris, and Capillaria, but these populations were too numerically small or too unevenly distributed within the control groups to be given much emphasis. The experimental parasitic populations which developed in the 10 control calves amounted to 91, 763 worms (total).