A Combined Phase 0/2 "Trigger" Trial Evaluating Pamiparib or Olaparib with Concurrent Radiotherapy in Patients with Newly-Diagnosed or Recurrent Glioblastoma

PURPOSE/OBJECTIVE(S)

This study evaluates the pharmacokinetic (PK) and pharmacodynamic (PD) profiles and clinical efficacy of PARP1/2 selective inhibitors, pamiparib and olaparib, in newly-diagnosed or recurrent glioblastoma (GBM) patients in combination with radiotherapy (RT).

MATERIALS/METHODS

In this combined phase 0/2 trial presumed newly-diagnosed (Arm A) or recurrent (Arm B) GBM patients received 4 days of pamiparib (60 mg BID) prior to resection either 2-4 or 8-12 hours following the final dose. Arm C enrolled patients with recurrent GBM to 4 days of olaparib (200 mg BID) prior to resection. Enhancing and nonenhancing tumor tissue, cerebrospinal fluid (CSF) and plasma were collected. Total and unbound drug concentrations were measured using validated LC-MS/MS methods. A PK 'trigger', defined as unbound drug and gt; 5-fold biochemical IC 50 in nonenhancing tumor, determined eligibility for the therapeutic expansion phase 2. PARP inhibition was assessed via ex vivo radiation and quantification of PAR levels compared to non-radiated control. Newly-diagnosed MGMT unmethylated GBMs and recurrent GBMs exceeding the PK threshold were eligible for an expansion phase of pamiparib (Arms A and B) or olaparib (Arm C) with concurrent RT followed by maintenance pamiparib or olaparib. RT was 60 Gy in 30 fractions in newly-diagnosed patients and 40 Gy in 15 fractions in recurrent patients, delivered using volumetric-modulated arc therapy (VMAT).

RESULTS

A total of 38 patients (Arm A, n = 16; Arm B, n = 16; Arm C, n = 6) were enrolled in the initial phase 0 study. The mean unbound concentrations of pamiparib in nonenhancing tumor region for Arm A and Arm B were 167.3 nM and 109.4 nM respectively, and in Arm C the mean unbound concentration of olaparib was 5.2 nM. All patients in the pamiparib arms (n = 32/32) but only 1 of 6 patients in the olaparib Arm C exceeded the PK threshold. Radiation-induced PAR expression was 2.44-fold in untreated control vs 1.16 in Arm A (p<0.05), 0.85 in Arm B (p<0.01) and 1.11 in Arm C patients, respectively. In Arm A, 11 patients had unmethylated tumors, and of those, 7 patients enrolled in phase 2. In Arm B, 9 of the 16 clinically eligible patients with positive PK results were enrolled in phase 2. At a median follow-up of 8.4 months [range: 1.3-15.7 months], the median progression-free survival (PFS) was 5.4, 6.0, and 3.8 months for Arms A (n = 7), B (n = 9), and C (n = 1), respectively. Grade 3+ toxicities related to pamiparib occurred in 4 patients, with 2 adverse events resulting in treatment discontinuation. No grade 3+ toxicities were documented in the olaparib arm.

CONCLUSION

Pamiparib achieved pharmacologically-relevant concentrations in nonenhancing GBM tissue and suppressed induction of PAR levels ex vivo post-radiation. The majority of patients with MGMT-unmethylated GBM advanced to the phase 2 portion of the trial, and pamiparib was generally well-tolerated in these patients.

A Combined Phase 0/2 "Trigger" Trial of Niraparib in Combination with Radiation in Patients with Newly-Diagnosed Glioblastoma

PURPOSE/OBJECTIVE(S)

Poly ADP-ribose (PAR) polymerase (PARP) mediates DNA damage response. Niraparib is an investigational PARP1/2-selective inhibitor. We conducted a combined phase 0/2 study to evaluate niraparib pharmacokinetics (PK) and pharmacodynamics (PD) in patients with newly-diagnosed glioblastoma (GBM), graduating patients to a phase 2 study evaluating a therapeutic regimen of niraparib with concurrent conventionally-fractionated radiotherapy (RT) in O6-methylguanine methyltransferase (MGMT) unmethylated tumors exceeding a prespecified PK threshold in non-enhancing tumor.

MATERIALS/METHODS

Patients with presumed newly-diagnosed GBM were enrolled in a phase 0 study receiving 4 days of niraparib (300 or 200 mg QD) prior to planned resection 3-5 or 8-12 hours following the last dose. Tumor tissue (enhancing and non-enhancing regions), cerebrospinal fluid (CSF), and plasma were collected. Total and unbound niraparib concentrations were measured using validated LC-MS/MS methods. PARP inhibition was assessed by quantification of PAR induction after 10 Gy ex vivo irradiation in surgical tissue compared to non-irradiated control tissue. A PK 'trigger' determined eligibility for the therapeutic phase 2 expansion portion of the study. This was defined as unbound [niraparib] > 5-fold biochemical IC50 (i.e., 19 nM) in non-enhancing tumor. Patients with MGMT unmethylated tumors exceeding this PK threshold were eligible for expansion phase dosing of niraparib with concurrent RT followed by a maintenance phase of niraparib. Patients with MGMT methylated tumors were not eligible for the expansion phase and proceeded with temozolomide (TMZ) plus RT followed by maintenance TMZ. RT dose was 60 Gy in 30 fractions using volumetric-modulated arc therapy (VMAT).

RESULTS

All 29 patients enrolled in the phase 0 portion of the study met the PK threshold. In non-enhancing regions, the mean unbound concentration of niraparib was 258.2 nM. The suppression of PAR levels after ex vivo RT was observed in 79% of the patients (17/22). Sixteen patients had unmethylated tumors, and of those, 11 patients enrolled in phase 2. Five of the 6 initial patients enrolled in phase 2 experienced thrombocytopenia related to niraparib, and 3/5 cases were deemed serious and life-threatening. Consequently, starting dose in both phases was lowered to 200 mg, and no serious AEs were observed thereafter. At a median follow-up of 8.1 months [range: 6.0-12.9 months], 6-month PFS was 64% with 4 patients remaining on treatment and 5 patients ongoing survival follow-up.

CONCLUSION

Niraparib achieves pharmacologically-relevant concentrations in non-enhancing, newly-diagnosed GBM tissue in excess of any other studied PARP inhibitor. When delivered with concurrent RT, niraparib was well-tolerated, with low rates of grade 3+ toxicity. Initial clinical efficacy data are encouraging.

Evaluation of the microstructure, optical properties and hopping conduction mechanism of rare earth doped Ba0.85Ca0.12RE0.03Ti0.90Zr0.04Nb0.042O3 ceramics (RE = Ce3+ and Pr3+)

The current research work examines the impact of Rare Earth (RE³⁺) ion substitution on the structural, optical and conduction properties of a Ba_0.85Ca_0.12RE_0.03Ti_0.90Zr_0.04Nb_0.042O₃ (BCRETZN) (RE = Ce, Pr) ceramic compound produced via a solid-state route. The Rietveld method of the X-ray data revealed a tetragonal (P4mm) structure at room temperature for our ceramic compound. The morphology of the compound was explored using Scanning Electron Microscopy (SEM) as well as optical response and conduction behavior. The photoluminescence properties revealed that the BCPrTZN sample results in green and red photoemissions under laser excitation at 450 nm at RT. Furthermore, for the BCCeTZN sample, the photoluminescence data demonstrated that strong violet emission bands were acquired, at RT upon an excitation at 350 nm. The electrical conduction process was verified via the correlated barrier Hopping method. The scaling behavior suggests that the electrical conduction mechanism is independent of temperature. The existence of Ce³⁺ and Pr³⁺ ions in these materials could have important technological potential in new multifunctional devices.

This work examines the impact of rare earth (RE³⁺) ion substitution on the structural, optical and conduction properties of a Ba_0.85Ca_0.12RE_0.03Ti_0.90Zr_0.04Nb_0.042O₃ (BCRETZN) (RE = Ce, Pr) ceramic compound produced via a solid-state route.

Wide variation of winter-induced sustained thermal energy dissipation in conifers: a common-garden study

Low temperature in winter depresses rates of photosynthesis, which, in evergreen plants, can exacerbate imbalances between light absorption and photochemical light use. Damage that could result from increased excess light absorption is minimized by the conversion of excitation energy to heat in a process known as energy dissipation, which involves the de-epoxidized carotenoids of the xanthophyll cycle. Overwintering evergreens employ sustained forms of energy dissipation observable even after lengthy periods of dark acclimation. Whereas most studies of photoprotective energy dissipation examine one or a small number of species; here, we measured the levels of sustained thermal energy dissipation of seventy conifer taxa growing outdoors under common-garden conditions at the Red Butte Garden in Salt Lake City, Utah, U.S.A. (forty nine taxa were also sampled for needle pigment content). We observed an extremely wide range of wintertime engagement of sustained energy dissipation; the percentage decrease in dark-acclimated photosystem II quantum efficiency from summer to winter ranged from 6 to 95%. Of the many pigment-based parameters measured, the magnitude of the seasonal decrease in quantum efficiency was most closely associated with the seasonal increase in zeaxanthin content expressed on a total chlorophyll basis, which explained only slightly more than one-third of the variation. We did not find evidence for a consistent wintertime decrease in needle chlorophyll content. Thus, the prevailing mechanism for winter decreases in solar-induced fluorescence emitted by evergreen forests may be decreases in fluorescence quantum yield, and wintertime deployment of sustained energy dissipation likely underlies this effect.

Abstract 1081: Genome-wide CRISPR screens reveal Hippo pathway activation as a resistance mechanism in BRAF mutant colon cancer

BRAF V600E mutations occur in a subset of colon cancers. These are typically resistant to chemotherapy and are associated with a poor outcome. Combination treatment with BRAF and EGFR inhibitors is superior to standard chemotherapy and has recently received FDA approval, however the early emergence of drug resistance is a significant clinical problem. Clinical studies of resistant patients have identified mutations and amplifications in the MAPK pathway as important resistance drivers.

To identify novel non-MAPK dependent resistance mechanisms, genome-wide CRISPR/Cas9 knockout screens were performed to identify genes causing resistance to a combination BRAF/MEK/EGFR inhibitor regimen in the BRAF mutant HT29 and LS411N colon cancer cell lines. A number of strong resistance hits were identified but importantly, only 3 genes (CSK, ARID1A and STK11) were detected as significantly enriched in both cell lines screened. Two of these, CSK and ARID1A, have been shown to play a role in activation of the Hippo signaling pathway.

The generation of CSK knockout colon cell lines confirmed resistance to BRAF/MEK/EGFR inhibition both in vitro and in vivo using xenograft models. Furthermore, since CSK is a negative regulator of SRC, re-sensitisation of resistant BRAF mutant CSK knockout cells was achieved by adding Src inhibitors (Dasatinib and Saracatinib) to the combination therapy. Nuclear localisation of the transcription factors YAP1 and WWTR1 and binding to TEAD family members are required for Hippo pathway activation and we confirmed significantly increased nuclear YAP1/WWTR1 in CSK knockout cells. Furthermore, YAP1/WWTR1 nuclear localisation in these cells was reversed by treatment with Src inhibitors. Novel pharmacological TEAD inhibitors have recently been developed and will also be used to confirm that resistance can be overcome by specifically targeting the Hippo pathway. Expression profiling of CSK knockout cells revealed significant enrichment of pathways associated with Hippo signaling. Genes involved in regulating Hippo pathway activation were also identified as CRISPR screen resistance hits in both lung and head and neck cancer cell lines, suggesting that this may be an important mechanism of resistance among other tumour types and not limited to the colon.

Here we show that activation of the Hippo pathway is a potential MAPK-independent resistance mechanism in BRAF mutant colon cancer, readily reversible by rational pharmacological targeting. Given the development of specific Hippo pathway inhibitors and plans for their use in clinical trials, activation of Hippo signaling should be considered in resistant BRAF mutant colon cancer where alterations in the MAPK pathway are not detected.

Citation Format: Jonathan S. Brammeld, Hannah Thorpe, Mar Arias Garcia, Stacey Price, Jamie Young, Matthias Pfeifer, Barbara Lupo, Kosuke Yusa, Livio Trusolino, Mathew Garnett, Andrea Bertotti, Chris Bakal, Ultan McDermott. Genome-wide CRISPR screens reveal Hippo pathway activation as a resistance mechanism in BRAF mutant colon cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 1081.

Implementation of image-guided brachytherapy as part of non-surgical treatment in inoperable endometrial cancer patients

OBJECTIVE

This study assessed outcomes of inoperable endometrial cancer (IEC) patients treated with definitive external beam radiation therapy (EBRT) followed by a 3D image-guided brachytherapy boost.

METHODS

All consecutive patients treated with EBRT followed by 3D image-guided brachytherapy for IEC were retrospectively included. EBRT delivered a dose of 45Gy. Then, patients had an uterovaginal brachytherapy guided by 3D imaging. Clinical target volume (CTV_BT) included the whole uterus and the initial disease extent. Gross tumour volume (GTV_res) included the residual disease at time of brachytherapy.

RESULTS

Twenty-seven patients were identified. Causes of inoperability were comorbidities (37%) or tumour loco regional extent (63%). Including EBRT and brachytherapy, the median D₉₀ (minimal dose delivered to 90% of the volume) was 60.7 Gy_EQD2 (IQR = 56.4-64.2) for the CTV_BT, and was 73.6 Gy_EQD2 (IQR = 64.1-83.7) for the GTV_res. The median overall treatment time was 50 days (IQR = 46-54). The mean follow-up was 36.5 months (SD = 30.2). The cumulative incidence of local, pelvic and distant failures was 19% (n = 5), 7% (n = 2) and 26% (n = 7), respectively. Five-year overall survival was 63% (95% CI = 43-91). Late urinary and gastro intestinal toxicities ≥ grade 2 were reported in four (15%) and two patients (7%) respectively. No vaginal toxicity ≥ grade 2 was reported.

CONCLUSIONS

EBRT followed by intracavitary brachytherapy seems to be an effective option for IEC. The implementation of 3D concepts at time of brachytherapy may contribute to high local control probability and low toxicity profile. Large scale retrospective or prospective data are needed to confirm these early data.

Surface morphology of amorphous SiO2 substrates bombarded with 1.0 MeV Si+ ions

Surface pattern formation on amorphous SiO₂ substrates by implantation of 1.0 MeV Si⁺ ions at a current of 1.3 µA at 70° angle is reported. Surface micrometer sized ripples perpendicular to the ion beam direction are formed, observed by scanning electron microscopy and atomic force microscopy. The morphological features are more or less similar for different fluences. The formation of surface ripples at this energy is discussed in terms of ion stopping mechanisms and patterns obtained within the low- and medium-energy ranges.

Measurement of the magnetic permeability of amorphous magnetic microwires by using their antenna resonance

We present here a new free space method to measure the magnetic permeability of a single amorphous magnetic microwire (AMM) at microwave frequencies. The technique consists in inducing a high frequency electric current along the AMM axis by illumination with an electromagnetic wave at antenna resonance conditions. Fitting the induced electric current to the Hallen-Pocklington equation allows computing the relative magnetic permeability of the microwire as a function of the wave frequency. The method results particularly useful for the study of the giant magnetoimpedance effect of AMM by measuring the magnetic permeability upon the application of DC magnetic fields.

Tuning Metamaterials by using Amorphous Magnetic Microwires

In this work, we demonstrate theoretically and experimentally the possibility of tuning the electromagnetic properties of metamaterials with magnetic fields by incorporating amorphous magnetic microwires. The large permeability of these wires at microwave frequencies allows tuning the resonance of the metamaterial by using magnetic fields of the order of tens of Oe. We describe here the physical basis of the interaction between a prototypical magnetic metamaterial with magnetic microwires and electromagnetic waves plus providing detailed calculations and experimental results for the case of an array of Split Ring Resonators with Co-based microwires.

Biomarkers of resistance to radiation therapy: a prospective study in cervical carcinoma

Background

Clinical parameters and proteins have recently been suggested as possible causes of radiotherapy (RT) resistance in cervical carcinoma (CC). The objective of the present study was to validate prognostic biomarkers of radiation resistance.

Methods

The present prospective study included patients undergoing RT with curative intent for histologically proven locally advanced squamous cell CC. Tissues and blood samples were systematically collected before RT initiation. Immuno-histochemistry was performed (IGF-IR α and β, GAPDH, HIF-1 alpha, Survivin, GLUT1, CAIX, hTERT and HKII). Response to radiation was assessed through tumour response 3 months after RT completion, through overall survival (OS) and through progression-free survival (PFS).

Results

One hundred forty nine patients with a mean age of 46 years were included, with FIGO IIB (n = 53) and FIGO IIIB (n = 96) CCs. 61 patients were treated with exclusive RT + brachytherapy and 88 underwent chemo-radiotherapy + brachytherapy. Our findings suggest an association between hemoglobin level (Hb) (>11 g/dL) and 3 months complete response (p = 0.02). Hb level < 11 g/dL was associated with decreased PFS (p = 0.05) and OS (p = 0.08). Overexpression of IGF-1R β was correlated with a decreased OS (p = 0.007). Overexpression of GLUT1 was marginally correlated with reduced OS (p = 0.05). PFS and OS were significantly improved in patients undergoing chemoradiation versus exclusive radiotherapy (PFS: p = 0.04; OS: p = 0.01).

Conclusions

IGF-1R β overexpression and Hb level (≤11 g/dl) were associated with poor prognosis, and thus appear to be possible interesting biomarkers of radiation resistance. Our results corroborate previous pre-clinical studies suggesting IGF-1R and hypoxia to be part of the biological pathways leading to radio-resistance.

Validation of suitable normalizers for miR expression patterns analysis covering tumour heterogeneity

Oncogenic microRNAs (miRs) have emerged as diagnostic biomarkers and novel molecular targets for anti-cancer drug therapies. Real-time quantitative PCR (qPCR) is one of the most powerful techniques for analyzing miRs; however, the use of unsuitable normalizers might bias the results. Tumour heterogeneity makes even more difficult the selection of an adequate endogenous normalizer control. Here, we have evaluated five potential referenced small RNAs (U6, rRNA5s, SNORD44, SNORD24 and hsa-miR-24c-3p) using RedFinder algorisms to perform a stability expression analysis in i) normal colon cells, ii) colon and breast cancer cell lines and iii) cancer stem-like cell subpopulations. We identified SNORD44 as a suitable housekeeping gene for qPCR analysis comparing normal and cancer cells. However, this small nucleolar RNA was not a useful normalizer for cancer stem-like cell subpopulations versus subpopulations without stemness properties. In addition, we show for the first time that hsa-miR-24c-3p is the most stable normalizer for comparing these two subpopulations. Also, we have identified by bioinformatic and qPCR analysis, different miR expression patterns in colon cancer versus non tumour cells using the previously selected suitable normalizers. Our results emphasize the importance of select suitable normalizers to ensure the robustness and reliability of qPCR data for analyzing miR expression.

Microenvironmental Heterogeneity Parallels Breast Cancer Progression: A Histology-Genomic Integration Analysis

BACKGROUND

The intra-tumor diversity of cancer cells is under intense investigation; however, little is known about the heterogeneity of the tumor microenvironment that is key to cancer progression and evolution. We aimed to assess the degree of microenvironmental heterogeneity in breast cancer and correlate this with genomic and clinical parameters.

METHODS AND FINDINGS

We developed a quantitative measure of microenvironmental heterogeneity along three spatial dimensions (3-D) in solid tumors, termed the tumor ecosystem diversity index (EDI), using fully automated histology image analysis coupled with statistical measures commonly used in ecology. This measure was compared with disease-specific survival, key mutations, genome-wide copy number, and expression profiling data in a retrospective study of 510 breast cancer patients as a test set and 516 breast cancer patients as an independent validation set. In high-grade (grade 3) breast cancers, we uncovered a striking link between high microenvironmental heterogeneity measured by EDI and a poor prognosis that cannot be explained by tumor size, genomics, or any other data types. However, this association was not observed in low-grade (grade 1 and 2) breast cancers. The prognostic value of EDI was superior to known prognostic factors and was enhanced with the addition of TP53 mutation status (multivariate analysis test set, p = 9 × 10-4, hazard ratio = 1.47, 95% CI 1.17-1.84; validation set, p = 0.0011, hazard ratio = 1.78, 95% CI 1.26-2.52). Integration with genome-wide profiling data identified losses of specific genes on 4p14 and 5q13 that were enriched in grade 3 tumors with high microenvironmental diversity that also substratified patients into poor prognostic groups. Limitations of this study include the number of cell types included in the model, that EDI has prognostic value only in grade 3 tumors, and that our spatial heterogeneity measure was dependent on spatial scale and tumor size.

CONCLUSIONS

To our knowledge, this is the first study to couple unbiased measures of microenvironmental heterogeneity with genomic alterations to predict breast cancer clinical outcome. We propose a clinically relevant role of microenvironmental heterogeneity for advanced breast tumors, and highlight that ecological statistics can be translated into medical advances for identifying a new type of biomarker and, furthermore, for understanding the synergistic interplay of microenvironmental heterogeneity with genomic alterations in cancer cells.

Exchange bias effect in Au-Fe3O4 nanocomposites

We report exchange bias (EB) effect in the Au-Fe3O4 composite nanoparticle system, where one or more Fe3O4 nanoparticles are attached to an Au seed particle forming 'dimer' and 'cluster' morphologies, with the clusters showing much stronger EB in comparison with the dimers. The EB effect develops due to the presence of stress at the Au-Fe3O4 interface which leads to the generation of highly disordered, anisotropic surface spins in the Fe3O4 particle. The EB effect is lost with the removal of the interfacial stress. Our atomistic Monte Carlo studies are in excellent agreement with the experimental results. These results show a new path towards tuning EB in nanostructures, namely controllably creating interfacial stress, and opens up the possibility of tuning the anisotropic properties of biocompatible nanoparticles via a controllable exchange coupling mechanism.

Paediatric gastroenterology evaluation of overweight and obese children referred from primary care for suspected non-alcoholic fatty liver disease

BACKGROUND

Screening overweight and obese children for non-alcoholic fatty liver disease (NAFLD) is recommended by paediatric and endocrinology societies. However, gastroenterology societies have called for more data before making a formal recommendation.

AIM

To determine whether the detection of suspected NAFLD in overweight and obese children through screening in primary care and referral to paediatric gastroenterology resulted in a correct diagnosis of NAFLD.

METHODS

Information generated in the clinical evaluation of 347 children identified with suspected NAFLD through screening in primary care and referral to paediatric gastroenterology was captured prospectively. Diagnostic outcomes were reported. The diagnostic performance of two times the upper limit of normal (ULN) for alanine aminotransferase (ALT) was assessed.

RESULTS

Non-alcoholic fatty liver disease was diagnosed in 55% of children identified by screening and referral. Liver disease other than NAFLD was present in 18% of those referred. Autoimmune hepatitis was the most common alternative diagnosis. Children with NAFLD had significantly (P < 0.05) higher screening ALT (98 ± 95) than children with liver disease other than NAFLD (86 ± 74). Advanced fibrosis was present in 11% of children. For the diagnosis of NAFLD, screening ALT two times the clinical ULN had a sensitivity of 57% and a specificity of 71%.

CONCLUSIONS

Screening of overweight and obese children in primary care for NAFLD with referral to paediatric gastroenterology has the potential to identify clinically relevant liver pathology. Consensus is needed on how to value the risk and rewards of screening and referral, to identify children with liver disease in the most appropriate manner.

A screen for morphological complexity identifies regulators of switch-like transitions between discrete cell shapes

The way in which cells adopt different morphologies is not fully understood. Cell shape could be a continuous variable or restricted to a set of discrete forms. We developed quantitative methods to describe cell shape and show that Drosophila haemocytes in culture are a heterogeneous mixture of five discrete morphologies. In an RNAi screen of genes affecting the morphological complexity of heterogeneous cell populations, we found that most genes regulate the transition between discrete shapes rather than generating new morphologies. In particular, we identified a subset of genes, including the tumour suppressor PTEN, that decrease the heterogeneity of the population, leading to populations enriched in rounded or elongated forms. We show that these genes have a highly conserved function as regulators of cell shape in both mouse and human metastatic melanoma cells.

Differential RNAi screening provides insights into the rewiring of signalling networks during oxidative stress

Reactive Oxygen Species (ROS) are a natural by-product of cellular growth and proliferation, and are required for fundamental processes such as protein-folding and signal transduction. However, ROS accumulation, and the onset of oxidative stress, can negatively impact cellular and genomic integrity. Signalling networks have evolved to respond to oxidative stress by engaging diverse enzymatic and non-enzymatic antioxidant mechanisms to restore redox homeostasis. The architecture of oxidative stress response networks during periods of normal growth, and how increased ROS levels dynamically reconfigure these networks are largely unknown. In order to gain insight into the structure of signalling networks that promote redox homeostasis we first performed genome-scale RNAi screens to identify novel suppressors of superoxide accumulation. We then infer relationships between redox regulators by hierarchical clustering of phenotypic signatures describing how gene inhibition affects superoxide levels, cellular viability, and morphology across different genetic backgrounds. Genes that cluster together are likely to act in the same signalling pathway/complex and thus make "functional interactions". Moreover we also calculate differential phenotypic signatures describing the difference in cellular phenotypes following RNAi between untreated cells and cells submitted to oxidative stress. Using both phenotypic signatures and differential signatures we construct a network model of functional interactions that occur between components of the redox homeostasis network, and how such interactions become rewired in the presence of oxidative stress. This network model predicts a functional interaction between the transcription factor Jun and the IRE1 kinase, which we validate in an orthogonal assay. We thus demonstrate the ability of systems-biology approaches to identify novel signalling events.

Development of a buffer system for dialysis of bovine spermatozoa before freezing. III. Effect of different inorganic and organic salts on fresh and frozen-thawed semen

Three experiments were conducted to study the effect of inorganic and organic acids on survival of dialyzed bovine spermatozoa. Ejaculates were pooled, extended (1:10), dialyzed (1:50) for 2 h during cooling, and 1 h later they were frozen in pellets and stored in liquid nitrogen. The pellets were thawed in aluminum block depressions (preheated at 45 degrees C) and transferred to a test tube at room temperature as the last ice melted. Sperm motility was recorded in all samples before freezing and after thawing. The number of spermatozoa that passed through the Sephadex column was analyzed in all the postthaw samples. No statistical difference (P>0.05) was found between the use of potassium (KOH) or sodium hydroxide (NaOH) as titration bases. However, solutions containing calcium (Ca++) or magnesium (Mg++) provided significantly less (P<0.05) protection to the cells during freezing and thawing. No significant difference (P>0.05) was found in sperm survival of the postthaw samples when Ca++ or Mg++ were present. Inorganic salts of phosphates, carbonates or chloride provided significantly less protection to the cells than the control extenders with Na citrate (P<0.05). Results of the second experiment indicated that citrate, tartrate and oxalate salts provided superior (P<0.05) protection to the cells than salts of succinate, acetate or formate. It was concluded that an appropriate solution for use as a dialysate of extended bovine spermatozoa may be formulated as 30% (V/V) isosmotic Na salt of Piperazine-N-N-BIS (2-ethane sulfonic acid) (PIPES) plus 30% (V/V) isosmotic glucose plus 5% (V/V) glycerol plus 35% (V/V) of isosmotic solutions of Na or K citrate or tartrate, or a (1:1) combination of them.

Development of a buffer system for dialysis of bovine spermatozoa before freezing. I. Effect of zwitterion buffers

The effect of N-TRIS(hydroxymethyl)methyl-2-aminoetane sulfonic acid (TES); N,N BIS (2 hydroxvethyl)-2 aminoethane sulfonic acid (BES), N-2(hydroxyethyl)piperazine-N-2-ethane sulfonic acid (HEPES), morpholinopropane sulfonic acid (MOPS), and piperazine-N-N-BIS(2-ethane sulfonic acid (PIPES) solutions on dialyzed semen was studied. Each was titrated to pH 7.0 with TRIS-(hydroxymethyl)-amino methane (TRIS) solution and the osmotic pressure was adjusted to between 320 to 325 mOsm/kg. The new solutions were identified as TEST, BEST, HEPEST, MOPST and PIPEST, respectively. The solutions were used 1) alone, 2) in a composite with equal parts (V/V) of each solution and 3) in a 1:1 (V/V) combination with isosmotic trisodium citrate solution. Later, TRIS and sodium hydroxide (NaOH) were compared as titration bases for piperazine-N-N-BIS (2-ethane sulfonic acid) (PIPES) and N-Tris(hydroxymethyl)methyl-2-aminoethane sulfonic acid (TES). Ejaculates were diluted 1:10 (V/V) in extenders containing buffer, 20% egg yolk and 5% glycerol (V/V). The samples were dialyzed (1:50) during cooling for a period of 2 h. Each sample was dialyzed against the same buffer system containing 5% glycerol without egg yolk and later it was frozen in pellets. The treatments were evaluated by observation of sperm motility in fresh and thawed semen samples. The latter were also analyzed by electronic count of cells that passed through the Sephadex column. Sperm survival was higher in PIPEST (PIPES titrated with TRIS) or the composite buffer, and the inclusion of 50% sodium citrate (Na citrate) improved significantly (P<0.05) sperm motility in fresh and frozen-thawed semen samples. There was no difference (P>0.05) between the titration bases. In the second experiment, sperm survival was superior in extenders containing PIPEST (P<0.05) than in those containing TEST independently of the inclusion of Na citrate.

Effect of photodiode angular response on surface plasmon resonance measurements in the Kretschmann-Raether configuration

We study the effect of photodiode angular response on the measurement of surface plasmon resonance (SPR) in metallic thin films using the Kretschmann-Raether configuration. The photodiode signal depends not only on the light intensity but also on the incidence angle. This implies that the photodiode sensitivity changes along the SPR curve. Consequently, the measured SPR spectrum is distorted, thus affecting fits and numerical analyses of SPR curves. We analyze the magnitude of this change, determine when it is significant, and develop a calibration method of the experimental setup which corrects for this type of spectral shape distortions.

SIRT1 stabilizes PML promoting its sumoylation

SIRT1, the closest mammalian homolog of yeast Sir2, is an NAD(+)-dependent deacetylase with relevant functions in cancer, aging, and metabolism among other processes. SIRT1 has a diffuse nuclear localization but is recruited to the PML nuclear bodies (PML-NBs) after PML upregulation. However, the functions of SIRT1 in the PML-NBs are unknown. In this study we show that primary mouse embryo fibroblasts lacking SIRT1 contain reduced PML protein levels that are increased after reintroduction of SIRT1. In addition, overexpression of SIRT1 in HEK-293 cells increases the amount of PML protein whereas knockdown of SIRT1 reduces the size and number of PML-NBs and the levels of PML protein in HeLa cells. SIRT1 stimulates PML sumoylation in vitro and in vivo in a deacetylase-independent manner. Importantly, the absence of SIRT1 reduces the apoptotic response of vesicular stomatitis virus-infected cells and favors the extent of this PML-sensitive virus replication. These results show a novel function of SIRT1 in the control of PML and PML-NBs.

Organophosphorus pesticide residues in raw milk and infant formulas from Spanish northwest

Residue levels of seven organophosphorus pesticides (OPPs), widely used as dairy cattle ectoparasiticides or in crops used for animal feed, were determined in raw milk and infant formulas. A total of 312 samples were collected (70 from infant formulas and 242 from raw milk) biweekly during a 24-month period. Pesticides were extracted by means of a solid phase system into acetone. An extract aliquot of acetone was injected into a gas chromatograph (GC) with a nitrogen-phosphorus detector. Recoveries of pesticides spiked in milk samples were 62.2 - 97.2 %. The frequency of total samples containing detectable levels of OPP residues was 6.73 % in total milk and 8.67 % in raw milk. The highest percentage incidence measured was for dichlorvos (5.78 %), followed by coumaphos (2.06 %), and parathion methyl (0.83 %). The range of positive results was calculated to be between 0.005 and 0.220 mg kg(- 1). No residue was detected in the final product (infant formulas), so any risk to consumer health, especially to children's health, would be limited.

Negative nonlocal resistance in mesoscopic gold Hall bars: absence of the giant spin Hall effect

We report the observation of negative nonlocal resistances in multiterminal mesoscopic gold Hall bar structures whose characteristic dimensions are larger than the electron mean-free path. Our results can only be partially explained by a classical diffusive model of the nonlocal transport, and are not consistent with a recently proposed model based on spin Hall effects. Instead, our analysis suggests that a quasiballistic transport mechanism is responsible for the observed negative nonlocal resistance. Based on the sensitivity of our measurements and the spin Hall effect model, we find an upper limit for the spin Hall angle in gold of 0.023 at 4.5 K.

Independent verification of element 114 Production in the ;{48}Ca + ;{242}Pu reaction

Independent verification of the production of element 114 in the reaction of 244-MeV ;{48}Ca with ;{242}Pu is presented. Two chains of time- and position-correlated decays have been assigned to ;{286}114 and ;{287}114. The observed decay modes, half-lives, and decay energies agree with published results. The measured cross sections at a center-of-target energy of 244 MeV for the ;{242}Pu(;{48}Ca,3-4n);{287,286}114 reactions were 1.4_{-1.2};{+3.2} pb each, which are lower than the reported values.

A pilot experience launching a national dose protocol for vascular and interventional radiology

The design of a national dose protocol for interventional radiology has been one of the tasks during the European SENTINEL Coordination Action. The present paper describes the pilot experience carried out in cooperation with the Spanish Society on Vascular and Interventional Radiology (SERVEI). A prospective sample of procedures was initially agreed. A common quality control of the X-ray systems was carried out, including calibration of the air kerma area product (KAP) meters. Occupational doses of the radiologists involved in the survey were also included in the survey. A total of 10 Spanish hospitals with interventional X-ray units were involved. Six hundred and sixty-four patient dose data were collected from 397 diagnostic and 267 therapeutic procedures. Occupational doses were evaluated in a sample of 635 values. The obtained KAP median/mean values (Gy.cm2) for the gathered procedures were: biliary drainage (30.6/68.9), fistulography (4.5/9.8), lower limb arteriography (52.2/60.7), hepatic chemoembolisation (175.8/218.3), iliac stent (45.9/73.2) and renal arteriography (39.1/59.8). Occupational doses (mean monthly values, in mSv) were 1.9 (over apron); 0.3 (under apron) and 4.5 (on hands). With this National experience, a protocol was agreed among the SENTINEL partners to conduct future similar surveys in other European countries.

Lightest isotope of Bh produced via the 209Bi(52Cr,n)260Bh reaction

The lightest isotope of Bh was produced in the new 209Bi(52Cr,n)260Bh reaction at the Lawrence Berkeley National Laboratory's 88-Inch Cyclotron. Positive identification was made by observation of eight correlated alpha particle decay chains in the focal plane detector of the Berkeley Gas-Filled Separator. 260Bh decays with a 35(-9)(+19) ms half-life by alpha particle emission mainly by a group at 10.16 MeV. The measured cross section of 59(-20)(+29) pb is compared to model predictions. The influence of the N=152 and Z=108 shells on alpha decay properties is discussed.

Sequential measurements of procalcitonin levels in diagnosing ventilator-associated pneumonia

The utility of procalcitonin levels to improve the accuracy of clinical and microbiological parameters in diagnosing ventilator-associated pneumonia (VAP) was evaluated. Sequential measurement of procalcitonin and C-reactive protein levels and the calculation of the simplified Clinical Pulmonary Infection Scores (CPIS) were performed in 44 patients mechanically-ventilated for >48 h with neither active infection for the duration or suspicion of VAP. Patients who developed extrapulmonary infection were excluded. In total, 20 cases were suspected of having VAP and diagnosis was microbiologically confirmed in nine. In patients with confirmed VAP, procalcitonin levels were higher than in those without VAP. C-reactive protein levels and CPIS were lower in patients without suspected VAP, but could not discriminate confirmed and nonconfirmed suspicion of VAP. The best sensitivity and specificity (78 and 97%, respectively) corresponded to procalcitonin. The CPIS resulted in the same sensitivity, but had a lower specificity (80%). C-reactive protein had the worst sensitivity (56%), but a good specificity (91%). A CPIS >or=6 combined with serum levels of procalcitonin >or=2.99 ng.mL(-1) did not improve the sensitivity (67%), but resulted in 100% specificity. Procalcitonin might be useful in the diagnosis of ventilator-associated pneumonia. Combined values of Clinical Pulmonary Infection Scores and procalcitonin below the cut-off points excluded false-positive diagnoses of ventilator-associated pneumonia.

Magnetic properties of ZnO nanoparticles

We experimentally show that it is possible to induce room-temperature ferromagnetic-like behavior in ZnO nanoparticles without doping with magnetic impurities but simply inducing an alteration of their electronic configuration. Capping ZnO nanoparticles ( approximately 10 nm size) with different organic molecules produces an alteration of their electronic configuration that depends on the particular molecule, as evidenced by photoluminescence and X-ray absorption spectroscopies and altering their magnetic properties that varies from diamagnetic to ferromagnetic-like behavior.

Effect of Renal Ischemia/Reperfusion on Gene Expression of a pH-Sensitive K+ Channel

BACKGROUND

Sodium reabsorption depends on the Na/K/ATPase activity coupled to basolateral K+ recycling through K+ channels. ATP depletion reduces pump activity and increases K+ leak resulting in transport dysfunction. Kir4.1 is a pH-sensitive K+ channel expressed in the basolateral membrane of distal tubules. In this study, we evaluated whether Kir4.1 is also expressed in proximal tubules (PTs) and whether renal ischemia alters Kir4.1 mRNA expression levels.

METHODS

The presence of Kir4.1 mRNA was evaluated in PTs microdissected from collagenase-treated rat kidneys. Kir4.1 expression levels were estimated in the renal cortex by multiplex RT-PCR after 30 or 60 min of renal ischemia followed by 1, 24, 48 or 72 h of reperfusion.

RESULTS

The PCR product obtained from isolated tubules was sequenced and showed approximately 98% homology with rat Kir4.1 cDNA. Ischemia/reperfusion for 30 min induced a time-dependent reduction in Kir4.1 mRNA expression in parallel with plasma creatinine, however recovery was delayed after 60 min of ischemia, remaining reduced after 72 h of reperfusion when plasma creatinine was already normalized.

CONCLUSION

Kir4.1 mRNA expression was decreased by renal ischemia. The ischemia-induced cellular K+ loss may be minimized by Kir4.1 downregulation and may contribute to the mechanism by which cellular acidification induces cell protection against ATP depletion.

Male systemic lupus erythematosus in a Latin-American inception cohort of 1214 patients

The objective of the study was to evaluate the influence of the male gender in the clinical presentation and outcome of systemic lupus erythematosus in a prospective inception cohort of Latin-American patients. Of the 1214 SLE patients included in the GLADEL cohort, 123 were male. Demographic characteristics as well as clinical manifestations, laboratory profile, activity and damage scores were evaluated at onset and during the course of the disease and compared with female patients. The median age at onset of the male patients was 27 and that at diagnosis 29.2 years. Delay to diagnosis was shorter in males (134 versus 185 days, P = 0.01). At onset, men more frequently showed fever (42.3 versus 27.0%, P = 0.001) and weight loss (23.6 versus 11.8%, P = 0.001). During disease course the incident of symptoms was: fever, 67.8 versus 55.6%, P = 0.012; weight loss, 47.2 versus 24.3%, P = 0.001; arterial hypertension, 37.4 versus 25.8%, P = 0.007; renal disease (persistent proteinuria and/or cellular casts), 58.5 versus 44.6%, P = 0.004); and hemolytic anemia, 19.5 versus 10.9%, P = 0.008. The laboratory results showed that: men more frequently had IgG anticardiolipin antibodies (68.2 versus 49%, P = 0.02) and low C3 (61.3 versus 48.1%, P = 0.03); 5/123 men died (4%) compared with 29/1091 women (2.7%). In conclusion, 10% of GLADEL's cohort patients were male. They showed a distinctive profile with shorter delay to diagnosis, higher incidence of fever, weight loss, arterial hypertension, renal disease, hemolytic anemia, IgG anticardiolipin antibodies and low C3. Although not statistically significant, mortality was higher in men.

Long-range correlations in rabbit brain neural activity

We have analyzed the presence of persistence properties in rabbit brain electrical signals by means of non-equilibrium statistical physics tools. To measure long-memory properties of these experimental signals, we have first determined whether the data are fractional Gaussian noise (fGn) or fractional Brownian motion (fBm) by calculating the slope of the power spectral density plot of the series. The results show that the series correspond to fBm. Then, the data were studied by means of the bridge detrended scaled windowed variance analysis, detecting long-term correlation. Three different types of experimental signals have been studied: neural basal activity without stimulation, the response induced by a single flash light stimulus and the average of the activity evoked by 200 flash light stimulations. Analysis of the series revealed the existence of persistent behavior in all cases. Moreover, the results also exhibited an increasing correlation in the level of long-term memory from recordings without stimulation, to one sweep recording or 200 sweeps averaged recordings. Thus, brain neural electrical activity is affected not only by its most recent states, but also by previous states much more distant in the past.

Grepafloxacin Concentration in Ocular Tissues after Intravenous Infusion in Rabbits with Intraocular Inflammation

PURPOSE

To determine the penetration of grepafloxacin into ocular tissues during experimental ocular inflammation.

METHODS

10 albino and 10 pigmented rabbits underwent a continuous intravenous infusion of the drug 24 h after injecting Salmonella typhimurium toxin intravitreously, creating ocular inflammation. The animals were killed and grepafloxacin levels were determined in plasma and ocular tissues using high performance liquid chromatography.

RESULTS

Grepafloxacin levels achieved a steady-state plasma concentration of 1.5 microg/ml. The drug diffused more towards vascularized tissues (chorioretina and iris) in both albino and pigmented rabbits with a tissue/serum ratio higher than 1. Grepafloxacin showed more affinity to pigmented tissue, rising levels of 40,000-50,000 ng/g in the chorioretina and iris in pigmented animals. After inflammation, grepafloxacin intraocular penetration increased in albino animals with levels exceeding the minimum inhibitory concentration for the most common ocular pathogens.

CONCLUSION

Grepafloxacin intraocular penetration is higher in pigmented tissues. Ocular inflammation increases the drug penetration into the vitreous.

Inactivation of the mouse adenylyl cyclase 3 gene disrupts male fertility and spermatozoon function

Mammalian spermatids and spermatozoa express functional G protein-coupled receptors. However, bicarbonate-regulated soluble adenylyl cyclase (AC), the major AC present in these cells, is not directly coupled to G proteins. To understand how G protein-coupled receptors signal in spermatozoa, we investigated whether a conventional transmembrane cyclase is present and biologically active in these cells. Here, we provide evidence for expression of type 3 AC (AC3) in male germ cells and describe the effects of disruption of the AC3 gene on fertility and function of mouse spermatozoa. As previously reported in rat, AC3 mRNA is expressed in mouse testes and localized, together with soluble AC mRNA, mainly in postmeiotic germ cells. AC3 protein was detected by immunolocalization in round and elongating spermatids in a region corresponding to the developing acrosome and was retained in the mature spermatozoa of the epididymis. Forskolin caused a small increase in cAMP production in mouse spermatozoa, but this increase could not be detected in the AC3(-/-) mice. Inactivation of the AC3 gene did not have overt effects on spermatogenesis; however, AC3(-/-) males were subfertile with only three litters generated by 11 males over a period of 6 months. When used in in vitro fertilization, spermatozoa from these AC3(-/-) mice produced few embryos, but their fertilizing ability was restored after removal of the zona pellucida. Despite an apparently normal structure, these spermatozoa had decreased motility and showed an increase in spontaneous acrosome reactions. These data support the hypothesis that AC3 is required for normal spermatid or spermatozoa function and male fertility.

Ocular penetration of grepafloxacin after intravitreal administration in albino and pigmented rabbits

Ocular penetration of grepafloxacin into several ocular tissues was determined in albino and pigmented rabbits following a single intravitreal administration. After administration, grepafloxacin was detected in all ocular tissues studied in both breeds of rabbits. The superior mean penetration ratios were found in the chorioretina and lens of albino rabbits, and in the chorioretina, iris and lens of pigmented rabbits. A significantly greater penetration of grepafloxacin was found in the chorioretina and iris of the pigmented rabbits than in those of the albino rabbits. As a final conclusion, grepafloxacin detected in different ocular structures could attain therapeutic concentrations against a variety of ocular conditions.

Determination of enro?oxacin and its primary metabolite, cipro?oxacin, in pig tissues. Application to residue studies

A simple and sensitive HPLC method has been developed for the simultaneous determination of enrofloxacin (ENR) and ciprofloxacin (CIP) in pig tissue using difloxacin (DIF) as internal standard. Tissue sample preparations were carried out by adding phosphate buffer (pH 7.4, 0.1 m), followed by extraction with trichloromethane. Fluoroquinolones were separated on a reversed-phase column and eluted with aqueous buffer solution-acetonitrile (80:20, v/v). The concentrations of CIP, ENR and DIF eluted from the column, with retention times of 2.20, 2.73 and 4.38 min, respectively, were monitored by fluorescence detection at lambda(ex) 276 and lambda(em) 442 nm. The detection and quantitation limit were 8 and 25 ng/g, respectively, for both compounds. Standard curves were linearly related to concentration in the range 25-400 ng/g. The consequences of the introduction of minor reasonable variations (ruggedness studies) have also been analysed. Finally, the measurement of the tissue levels of ENR and CIP in the pig tissues after oral administration confirmed the utility of the proposed method.

Micellar electrokinetic chromatography with bile salts for predicting ecotoxicity of aromatic compounds

The retention factors of several aromatic compounds were obtained by micellar electrokinetic chromatography (MEKC) using cholate, taurocholate, deoxycholate and deoxytaurocholate as micellar systems. The possibility of using these retention factors to describe and predict several ecotoxicological activities of different aromatic compounds was evaluated. Adequate correlations retention-ecotoxicity (log LC50 in fish and daphnia, log EC50 in green algae and daphnia, chronic values in fish and green algae, bioconcentration factor, and soil sorption coefficient) were obtained for the micellar systems studied. The predictive ability of the models obtained for these micellar systems was compared. Predicted values concur with the experimental log LC50 in Bluegill, Rainbow trout, Fathead minnows and Daphnia Magna values for the compounds studied. The results obtained indicated the usefulness of the MEKC systems investigated for the rapid ecotoxicity assessment of aromatic compounds.

Recognition of ESAT-6 sequences by antibodies in sera of tuberculous nonhuman primates

Previous work in our laboratory showed that the ESAT-6 protein of Mycobacterium tuberculosis and Mycobacterium bovis induces strong antibody responses in a large proportion ( approximately 90%) of experimentally or naturally infected nonhuman primates. Here, the antibody response to ESAT-6 in tuberculous monkeys was characterized at the epitope level by measuring antibodies to overlapping, synthetic peptides spanning the ESAT-6 sequence. The antibody response against the COOH-terminal portion of the protein was the strongest in both experimentally and naturally infected animals. Moreover, these antibodies became detectable the earliest during experimental infection, suggesting an ordered expansion of ESAT-6-specific B-cell clones in the course of infection. The data support use of synthetic peptides in lieu of the full-length ESAT-6 protein in diagnostic antibody detection assays.

Penetration of diltiazem into breast milk and its pharmacokinetics in the lactating rabbit

1. The aim was to investigate the milk transfer and pharmacokinetics of diltiazem (DTZ) in the lactating rabbit following DTZ intravenous (i.v.) administration. In addition, DTZ metabolism in mammary tissue and milk was also studied. 2. The pharmacokinetic parameters that largely determine drug disposition (AUC, VD, CL) showed no significant differences between the non-lactating and lactating rabbit. 3. When DTZ was administered to the lactating rabbit, the observed DTZ milk-to-blood AUC ratio (M/B) closely correlated with the calculated ratio, as predicted by a diffusional model, suggesting that DTZ passes into milk via non-ionic diffusion and that other factors which may affect the milk transfer seem to have limited relevance. 4. After a single intravenous dose of DTZ to the lactating rabbit, deacetyldiltiazem (M1) and demethyldiltiazem (MA) were observed in blood, but only M1 could be detected in milk. 5. In conclusion, DTZ seems to diffuse freely into milk after its i.v. administration to the lactating rabbit and should not be given to nursing mammals because of the potential risk for their young. This risk may be even higher because of the presence of M1 (a pharmacologically active metabolite) in milk after administration of the parent drug.

Dis1/TOG universal microtubule adaptors - one MAP for all?

Microtubules play central roles in various cellular processes in eukaryotes. The dynamics and organisation of interphase microtubules and mitotic spindles are dramatically altered during the cell cycle and development. However, the molecular mechanisms underlying this dynamic behaviour remain to be understood. In recent years, a novel family of microtubule-associated proteins (MAPs), the Dis1/TOG family, has emerged as a versatile regulator of microtubule function. These MAPs are highly conserved in eukaryotes from yeasts and plants to humans. The localisation and function of these MAPs are not determined simply by their intrinsic microtubule-binding activity. Instead this family executes its diverse roles by interacting with other regulatory molecules, including microtubule motors and centrosomal proteins. The modular structure of these MAPs may allow them to interact with multiple proteins and thereby be involved in a wide variety of microtubule and spindle functions.

Movies available on-line

Soil temperature and diapause maintenance in eggs of the spittlebug, Deois flavopicta (Hemiptera: Cercopidae)

Diapausing eggs of the neotropical pasture pest, Deois flavopicta (Stal) (Hemiptera: Cercopidae), were exposed to low overnight temperatures that simulated field conditions during the dry season (23/12, 23/15 and 23/18 degrees C day/night), for different periods (0-60 days). After treatment, eggs were kept at 28 degrees C and contact water (100% humidity) until hatching. A group of diapausing eggs were kept all the time under this last condition as a control treatment. Time for hatching (in degree-days) was reduced with decrease in low overnight temperature and increase of exposure time to these cold shocks, although there was no interaction between the factors. Regression of exposure time to cold shock influencing the expected mean hatching time produced independent equations for temperatures below 18 degrees C and 15 degrees C. We constructed a model that simulates the expected proportion of the population hatching after the beginning of rainy season based on regression equations to mean hatching time and associated standard deviation. The simulation generated for the model correlated significantly with nymphal population observed in the field. These results showed that overnight soil temperatures below 18 degrees C, as occurs in Central and South-eastern Brazil between May and August, shorten the period of diapause, increase quiescent eggs in the soil, and may have synchronize population hatching.

Palaeolithic paintings. Evolution of prehistoric cave art

Sophisticated examples of European palaeolithic parietal art can be seen in the caves of Altamira, Lascaux and Niaux near the Pyrenees, which date to the Magdalenian period (12,000-17,000 years ago), but paintings of comparable skill and complexity were created much earlier, some possibly more than 30,000 years ago. We have derived new radiocarbon dates for the drawings that decorate the Chauvet cave in Vallon-Pont-d'Arc, Ardèche, France, which confirm that even 30,000 years ago Aurignacian artists, already known as accomplished carvers, could create masterpieces comparable to the best Magdalenian art. Prehistorians, who have traditionally interpreted the evolution of prehistoric art as a steady progression from simple to more complex representations, may have to reconsider existing theories of the origins of art.

Cloning and genetic characterization of dca genes required for beta-oxidation of straight-chain dicarboxylic acids in Acinetobacter sp. strain ADP1

A previous study of deletions in the protocatechuate (pca) region of the Acinetobacter sp. strain ADP1 chromosome revealed that genes required for utilization of the six-carbon dicarboxylic acid, adipic acid, are linked to the pca structural genes. To investigate the genes involved in adipate catabolism, a 33.8-kb SacI fragment, which corrects a deletion spanning this region, was cloned. In addition to containing known pca, qui, and pob genes (for protocatechuate, quinate, and 4-hydroxybenzoate dissimilation), clone pZR8000 contained 10 kb of DNA which was the subject of this investigation. A mutant strain of Escherichia coli DH5alpha, strain EDP1, was isolated that was able to utilize protocatechuate and 4-hydroxybenzoate as growth substrates when EDP1 cells contained pZR8000. Sequence analysis of the new region of DNA on pZR8000 revealed open reading frames predicted to be involved in beta-oxidation. Knockouts of three genes implicated in beta-oxidation steps were introduced into the chromosome of Acinetobacter sp. strain ADP1. Each of the mutants was unable to grow with adipate. Because the mutants were affected in their ability to utilize additional saturated, straight-chain dicarboxylic acids, the newly discovered 10 kb of DNA was termed the dca (dicarboxylic acid) region. Mutant strains included one with a deletion in dcaA (encoding an acyl coenzyme A [acyl-CoA] dehydrogenase homolog), one with a deletion in dcaE (encoding an enoyl-CoA hydratase homolog), and one with a deletion in dcaH (encoding a hydroxyacyl-CoA dehydrogenase homolog). Data on the dca region should help us probe the functional significance and interrelationships of clustered genetic elements in this section of the Acinetobacter chromosome.

Development of diltiazem deacetylase and demethylase activities during ontogeny in rabbit

1. Diltiazem (DTZ) undergoes extensive metabolism in hepatic and extrahepatic tissues. Deacetyldiltiazem (M1) and N-desmethyldiltiazem (MA) are two of the main basic metabolites of DTZ that retain pharmacological activity. The development of DTZ deacetylase and demethylase activities through ontogeny has not been addressed. In order to address this issue, in vitro studies have been carried out using the blood and several tissues of rabbit as enzyme sources. In addition, in vivo studies using a pharmacokinetic approach were carried out to support the in vitro findings. 2. DTZ was incubated with homogenates of selected tissues and in whole blood and DTZ, and its metabolites were assayed by HPLC. In addition, a pharmacokinetic study after intraperitoneal administration of DTZ in the 1-, 8-, 16-, 30-day-old and adult rabbit were also carried out. 3. DTZ deactylase activity was detected whatever the age and tissue examined (including blood). Except in gut homogenates, this activity was shown to be higher at earlier postnatal ages. DTZ demethylase activity was only detected in the liver and gut homogenates and in whole blood. This activity increases from the 1- to 30-day-old rabbit (except for blood), after which it decreases slightly to reach the adult level. 4. In vivo experiments showed a close pharmacokinetic profile throughout ontogeny (except for the 30-day-old rabbit) after DTZ intraperitoneal administration. 5. Extrahepatic metabolism may play a more significant role in the overall metabolism and pharmacokinetics of DTZ at earlier stages of development. 6. Finally, in vivo studies Suggest that age does not seem to modify DTZ disposition and, for this reason, dosage may not have to be taken into account as a function of age.

Elevated expression of glucose transporter-1 in hypothalamic ependymal cells not involved in the formation of the brain-cerebrospinal fluid barrier

Glucose transporters play an essential role in the acquisition of glucose by the brain. Elevated expression of glucose transporter-1 has been detected in endothelial cells of the blood-brain barrier and in choroid plexus cells of the blood-cerebrospinal fluid barrier. On the other hand, there is a paucity of information on the expression of glucose transporters in the ependymal cells that line the walls of the cerebral ventricles. The tanycytes are specialized ependymal cells localized in circumventricular organs such as the median eminence that can be segregated into at least three types, alpha, beta1 and beta2. The beta2 tanycytes form tight junctions and participate in the formation of the cerebrospinal fluid-median eminence barrier. Using immunocytochemistry and in situ hybridization, we analyzed the expression of hexose transporters in rat and mouse hypothalamic tanycytes. In both species, immunocytochemical analysis revealed elevated expression of glucose transporter-1 in alpha and beta1 tanycytes. Intense anti-glucose transporter-1 staining was observed in cell processes located throughout the arcuate nucleus, in the end-feet reaching the lateral sulcus of the infundibular region, and in cell processes contacting the hypothalamic capillaries. On the other hand, there was very low expression of glucose transporter-1 in beta2 tanycytes involved in barrier function. In contrast with the results of the cytochemical analysis, in situ hybridization revealed that tanycytes alpha, beta1, and beta2 express similar levels of glucose transporter-1 mRNA. Further analysis using anti-glial fibrillary acidic protein antibodies to identify areas rich in astrocytes revealed that astrocytes were absent from areas containing alpha and beta1 tanycytes, but were abundant in regions containing the barrier-forming beta2 tanycytes. Overall, our data reveal a lack of correlation between participation in barrier function and expression of glucose transporter-1 in hypothalamic tanycytes. Given the virtual absence of astrocytes in areas rich in alpha and beta1 tanycytes, we speculate whether the tanycytes might have astrocyte-like functions and participate in the metabolic coupling between glia and neurons in the hypothalamic area.

Immediate steps for treating abrasions

In any athletic setting, the skin represents the interface between the participant and the sports environment (1). Unfortunately, this interface is often disrupted when the athlete comes into a very intimate relationship with this environment, resulting in an abrasion.

Altered diltiazem metabolism in the neonatal rabbit following intra-uterine chronic exposure to diltiazem

1. Diltiazem undergoes extensive metabolism in hepatic and extrahepatic tissues. Deacetyldiltiazem (M1) and N-demethyldiltiazem (MA) are two of the main basic metabolites of diltiazem that retain pharmacological activity. This drug impairs its own metabolism after chronic administration in the adult patient. The study examines the possibility that intra-uterine exposure following chronic maternal therapy with DTZ from mid-gestation to term also impairs DTZ metabolism of its offspring. 2. DTZ was incubated in homogenates from liver, lung, brain and gut and in the whole blood of animals whose mothers were exposed to chronic treatment with diltiazem or unexposed (placebo). DTZ and its metabolites were assayed by HPLC. 3. DTZ deacetylase activity observed in liver, lung and brain homogenates from 1-, 8- and 16-day-old rabbits was significant lower in exposed animals. In gut homogenates, this age-dependent effect was not so clear. This inhibition could not be detected in any organ of 30-day-old rabbits. On the other hand, the activity observed in whole blood was not altered by intra-uterine chronic exposure to DTZ. 4. DTZ demethylase activity showed no differences in tissue homogenates and in whole blood from exposed compared with the unexposed rabbit. 5. In conclusion, the findings suggest that intra-uterine chronic exposure to DTZ has a large and prolonged effect on newborn metabolism deacetylase activity compared with the unexposed rabbit.

Pharmacokinetics of verapamil in New Zealand white rabbits during ontogeny

The pharmacokinetics of verapamil during ontogeny in rabbits and in vitro verapamil demethylase activity have been investigated in the liver and whole blood. In vivo experiments revealed that the slope of the postdistributive phase as well as the area under the curve and clearance showed significant differences when newborn and adult rabbits were compared. Other pharmacokinetic parameters, such as volume of distribution and plasma protein binding did not show any statistical differences. Liver microsomal preparation samples from 1-, 8- and 16-day-old rabbits displayed approximately 20% of the activity observed in adults. A significant verapamil demethylase activity in the whole blood of rabbits was also noted. The in vivo results show that newborn rabbits have a capacity to eliminate verapamil that is similar or even higher than that of adults. These findings could not be explained with regard to the in vitro liver metabolism of verapamil, although they could with respect to blood metabolism.