Outcomes of Brain Metastases with Suspicious Imaging Undergoing Resection to Evaluate for Radionecrosis vs. Tumor Progression

PURPOSE/OBJECTIVE(S)

In patients treated with stereotactic radiosurgery (SRS) for brain metastases, radiographic changes on surveillance imaging may result from treatment effect/radionecrosis (RN) or tumor progression. Distinguishing between these processes is critical to appropriate management. We report long-term outcomes for a cohort of patients who demonstrated radiographic progression on serial imaging after initial radiation and ultimately underwent resection to inform further management.

MATERIALS/METHODS

A retrospective chart review identified 76 patients with an associated 82 brain lesions between 2009 and 2022 that were initially treated with SRS, then demonstrated suspicious imaging changes developing through at least two scan time points that led to pathologic confirmation of either tumor or RN. We report clinical outcomes and details of further treatments.

RESULTS

Of the 82 lesions, 55 (67.1%) were found to be pathologically-confirmed viable tumor and were treated with repeat radiation and 27 (32.9%) were found to be strictly RN and conservatively managed. Over half of the lesions (14/27) ultimately found to be radionecrotic required use of steroids pre-operatively due to neurologic symptoms. Among the 27 that were found to be RN, the most common histology was melanoma (33.3%, n = 9). The most common dose fractionation regimen was 20 Gy in 1 fx (n = 11, 40.7%; range: 16-20 Gy x 1Fx), and the median BED (10) was 50.4 Gy (IQR 41.6 - 50 Gy). None of these lesions required further intervention with median post-surgery follow up of 24.4 months (range 1-104 months). There were 55 instances (in 51 patients) of pathologically-confirmed recurrent/progressive tumor who were consequently treated with repeat radiation with either Cs-131 brachytherapy (12 (21.8%)) or SRS (43 (78.2%)). The most common histology was NSCLC (37.2%, n = 19). The most common fractionation for repeat irradiation with SRS was 8 Gy x 3 fx (n = 15, 27.3%), followed by 5 Gy x 5 fx (n = 10, 18.2%), and 4 Gy x 5 fx (n = 8, 14.6%). Four individuals each had two lesions that were re-irradiated for local recurrence. Among patients treated with re-irradiation, the median follow-up to local failure was 15.2 months (95% CI 7.3-26.6 months). Radionecrosis was confirmed on pathology in 4/55 (7.2%) of lesions. The median follow-up from date of SRS2 to local failure was 14.1 months (95% CI 7.6-24.3 months). The 2-yr local control rate was 74.8% (95% CI 61.7-90.7%).

CONCLUSION

We recommend cautious monitoring of possible progression after radiosurgery, with consideration of resection for continuous progression, as a significant proportion of radiographic progression are ultimately pure RN. Management determined by pathology (observation for RN; additional radiation for confirmed tumor) leads to excellent control.

Reliable metal-graphene contact formation process flows in a CMOS-compatible environment

The possibility of exploiting the enormous potential of graphene for microelectronics and photonics must go through the optimization of the graphene-metal contact. Achieving low contact resistance is essential for the consideration of graphene as a candidate material for electronic and photonic devices. This work has been carried out in an 8'' wafer pilot-line for the integration of graphene into a CMOS environment. The main focus is to study the impact of the patterning of graphene and passivation on metal-graphene contact resistance. The latter is measured by means of transmission line measurement (TLM) with several contact designs. The presented approaches enable reproducible formation of contact resistivity as low as 660 Ω μm with a sheet resistance of 1.8 kΩ/□ by proper graphene patterning, passivation of the channel and a post-processing treatment such as annealing.

Determining degradation kinetics, byproducts and toxicity for the reductive treatment of Nitroguanidine (NQ) by magnesium-based bimetal Mg/Cu

Energetic-laden process water from industrial munition facilities can be treated by zero-valent metals (ZVMs) or zero-valent iron (ZVI) to remove residual energetics. This reduction-based treatment is significantly enhanced with the addition of a secondary catalytic metal (i.e. forming a bimetal reagent). The reagent is further enhanced by using a more reductive base metal, such as Mg. In this work, the reductive degradation of nitroguanidine (NQ) in aqueous solutions by Mg/Cu bimetal is investigated. Two initial pH conditions (unadjusted and pH 2.7) were studied. Under unadjusted initial pH conditions, 90% of NQ degraded within 30 min reaction time. After 150 min, NQ degradation generated a suite of products including guanidine (44%), cyanamide (31%), formamide (15%), aminoguanidine (AQ) (6%), urea (2%) and cyanoguanidine (0.03%), leading to 100.0% carbon closure when accounting for residual NQ. The experimentally-derived degradation reaction pathway consisted of two parallel reactions: nitroreduction led to formation of AQ with further degradation to urea, cyanamide and formamide, or reductive cleavage of the N-N bond led to guanidine formation. Toxicological assessments indicated only cyanamide and AQ were toxic to S. obliquus at certain concentrations. A lowered initial pH promoted AQ transformation to benign formamide, thus reducing toxicity and complexity of products.

Influence of plasma treatment on SiO2/Si and Si3N4/Si substrates for large-scale transfer of graphene

One of the limiting factors of graphene integration into electronic, photonic, or sensing devices is the unavailability of large-scale graphene directly grown on the isolators. Therefore, it is necessary to transfer graphene from the donor growth wafers onto the isolating target wafers. In the present research, graphene was transferred from the chemical vapor deposited 200 mm Germanium/Silicon (Ge/Si) wafers onto isolating (SiO₂/Si and Si₃N₄/Si) wafers by electrochemical delamination procedure, employing poly(methylmethacrylate) as an intermediate support layer. In order to influence the adhesion properties of graphene, the wettability properties of the target substrates were investigated in this study. To increase the adhesion of the graphene on the isolating surfaces, they were pre-treated with oxygen plasma prior the transfer process of graphene. The wetting contact angle measurements revealed the increase of the hydrophilicity after surface interaction with oxygen plasma, leading to improved adhesion of the graphene on 200 mm target wafers and possible proof-of-concept development of graphene-based devices in standard Si technologies.

SAT0135 COMPARISON OF THE EFFICACY AND SAFETY OF TWO BRIDGING SCHEDULES OF PREDNISOLONE IN EARLY ACTIVE RHEUMATOID ARTHRITIS (CORRA): A DOUBLE-BLIND, RANDOMISED, PLACEBO-CONTROLLED TRIAL

Background:

Rheumatoid arthritis (RA) is a chronic inflammatory joint disease potentially leading to disability, impaired functioning, and premature death. Most treatment strategies include the early use of disease-modifying antirheumatic drugs (DMARDs) such as methotrexate (MTX) which is considered as an established ‘anchor’ therapy. Since it takes some weeks until MTX shows clinical efficacy, glucocorticoids (GC) are widely used for bridging.

Objectives:

The aim of the study “Comparison of the efficacy and safety of two starting dosages of prednisolone in early active RA” (CORRA) is to compare the efficacy and safety of two standard GC bridging schedules vs. placebo in addition to MTX, following a treat-to-target regimen, in early RA.

Methods:

CORRA is an investigator-initiated, randomised, multi-center, double-blind, placebo-controlled trial. Adult RA patients who were eligible for inclusion in the trial if they had a disease duration of less than 3 years and moderate or high disease activity were recruited in one hospital and 18 rheumatology practices in Germany. Patients were randomised (1:1:1) to receive 60 mg or 10 mg prednisolone (Pred) orally once daily (tapered down to 5 mg Pred within 8 weeks) or placebo. The duration of the intervention was 12 weeks, followed by an open observational phase for another 40 weeks. All patients were also treated with MTX (usually starting with 15mg/week followed by a treat-to target scheme). The primary efficacy endpoint was the progression of the radiographic joint damage after one year compared to baseline as determined by the van der Heijde modification of the Sharp score (SHS). Patients, physicians and readers of radiographs were unaware of the treatment assignments. For the comparison of the two GC groups, a non-inferiority margin of 1.3 points of the SHS was set. This trial was registered at ClinicalTrials.gov, numberNCT02000336.

Results:

Between February 2014 and February 2017, 395 patients were included in the trial, 381 of which had sufficient data also of follow-up visits. A total of 129 patients were assigned to the 60 mg Pred group, 124 to 10 mg Pred and 128 to the placebo group. At baseline, mean age was 58 years, 58% were female, 55% were rheumatoid factor and 52% ACPA positive. The mean number of swollen joints was 12.8 out of 28, mean ESR was 33.6 mm/h, mean CRP 2.2 mg/dL, mean DAS 28 6.0. Radiographic damage was 4.9 as measured by the SHS. In the 60 mg, 10 mg Pred group and in the placebo group, the DAS 28 was 2.6, 3.1, 4.5 at week 4 (p<0.001), 3.1, 2.8, 3.6 at week 12 (p<0.001), and 2.7, 2.6, 2.8 at week 52 (p=0.411), respectively. After 12 months the radiographic progression could be determined in 375 patients. In the 60 mg, 10 mg Pred group, and in the placebo group, the mean progression after 1 year was 1.0, 1.0, 1.1 for the total SHS and 0.5, 0.6, 0.7 for the erosion score of the SHS, respectively. Statistical analysis showed non-inferiority of the 10 mg Pred and of the placebo group in comparison to the 60 mg Pred group. Regarding safety issues, there were 10, 5, 6 serious adverse events and 31, 16, 20 adverse events in the MedDRA system organ class “infections and infestations” for the 60 mg Pred, 10 mg Pred, and the placebo group, respectively.

Conclusion:

The bridging schedule starting with 60 mg Pred reduced disease activity better than the 10 mg schedule or placebo only for a short time. The primary outcome structural damage was non-inferior in the 10 mg Pred and the placebo group in comparison to the 60 mg Pred group. Initial advantages of the higher dose may have been compromised by the long follow-up with the possible escalation of therapy due to the treat-to-target regimen.

Disclosure of Interests:

Dietmar Krause Grant/research support from: Pfizer and AbbVie (Abbott), Anna Mai: None declared, Nina Timmesfeld: None declared, Ulrike Trampisch: None declared, Renate Klaassen-Mielke: None declared, Henrik Rudolf: None declared, Xenofon Baraliakos Grant/research support from: Grant/research support from: AbbVie, BMS, Celgene, Chugai, Merck, Novartis, Pfizer, UCB and Werfen, Consultant of: AbbVie, BMS, Celgene, Chugai, Merck, Novartis, Pfizer, UCB and Werfen, Speakers bureau: AbbVie, BMS, Celgene, Chugai, Merck, Novartis, Pfizer, UCB and Werfen, Elmar Schmitz: None declared, Claas Fendler: None declared, Claudia Klink: None declared, Stephanie Boeddeker: None declared, Ertan Saracbasi: None declared, Jochen Christoph: None declared, Manfred Igelmann: None declared, Hans Juergen Menne: None declared, Albert Schmid: None declared, Hans J Trampisch: None declared, Juergen Braun Grant/research support from: Abbvie (Abbott), Amgen, BMS, Boehringer, Celgene, Celltrion, Centocor, Chugai, Eli Lilly and Company, Medac, MSD (Schering Plough), Mundipharma, Novartis, Pfizer (Wyeth), Roche, Sanofi- Aventis, and UCB Pharma, Consultant of: Abbvie (Abbott), Amgen, BMS, Boehringer, Celgene, Celltrion, Centocor, Chugai, EBEWE Pharma, Eli Lilly and Company, Medac, MSD (Schering-Plough), Mundipharma, Novartis, Pfizer (Wyeth), Roche, Sanofi-Aventis, and UCB Pharma, Speakers bureau: Abbvie (Abbott), Amgen, BMS, Boehringer, Celgene, Celltrion, Centocor, Chugai, EBEWE Pharma, Eli Lilly and Company, Medac, MSD (Schering-Plough), Mundipharma, Novartis, Pfizer (Wyeth), Roche, Sanofi-Aventis, and UCB Pharma

Value of antigranulocyte scintigraphy with Tc-99m-sulesomab in diagnosing combat-related infections of the musculoskeletal system

AIM

Combat-related extremity injuries are regularly associated with long-term complications such as chronic infection, especially osteomyelitis. Clinical examination and laboratory parameters do not usually allow reliable diagnosis. In contrast, imaging techniques enable constructive assertions to be made about the location and extent of an infection of the peripheral musculoskeletal system. The aim of this study was therefore to determine the diagnostic reliability of three-phase bone scanning and antigranulocyte scintigraphy using Tc-99m-sulesomab (Leukoscan) in the diagnostic clarification of infections associated with combat-related extremity injuries.

METHODS

Twenty-seven male patients (mean age 33.9 years) with suspected combat-associated infections of the extremities were included in this retrospective analysis. All patients underwent three-phase bone scanning using Tc-99m-HDP followed by antigranulocyte scintigraphy with Tc-99m-sulesomab. In 26 of the 27 patients, a CT scan of affected limb was obtained, where the secondary fusion with single photon emission CT data set was possible. The diagnostic reliability of imaging techniques was validated against microbiological samples obtained during surgery and used as gold standard.

RESULTS

Three-phase bone scanning yielded a positive result in all patients, with 18 scans classified as true positive (TP) and nine scans as false positive (FP). This produced a sensitivity of 100%, a specificity of 0% and a positive predictive value (PPV) of 67%. Antigranulocyte scintigraphy recognised 13 patients as TP, 1 patient as FP, 8 patients as true negative (TN) and 5 patients as false negative (FN), which gave a sensitivity of 72%, a specificity of 88%, a PPV of 93%, a negative predictive value (NPV) of 62% and an accuracy of 78%. CT recognised in 7 cases a TP result, in 3 cases an FP, in 5 cases a TN and in 11 cases an FN result. This produced a sensitivity of 39%, a specificity of 63%, a PPV of 70%, an NPV of 31% and an accuracy of 46%.

CONCLUSIONS

Three-phase bone scanning did not deliver any diagnostic benefit, since no result was able to differentiate unequivocally between infection-related and reactive changes. Antigranulocyte scintigraphy using Tc-99m-sulesomab represented a highly suitable technique for diagnostically clarifying combat-related infections of the extremities. It is superior to CT in sensitivity, specificity, PPV, NPV and accuracy.

Metal-Free CVD Graphene Synthesis on 200 mm Ge/Si(001) Substrates

Good quality, complementary-metal-oxide-semiconductor (CMOS) technology compatible, 200 mm graphene was obtained on Ge(001)/Si(001) wafers in this work. Chemical vapor depositions were carried out at the deposition temperatures of 885 °C using CH₄ as carbon source on epitaxial Ge(100) layers, which were grown on Si(100), prior to the graphene synthesis. Graphene layer with the 2D/G ratio ∼3 and low D mode (i.e., low concentration of defects) was measured over the entire 200 mm wafer by Raman spectroscopy. A typical full-width-at-half-maximum value of 39 cm^-1 was extracted for the 2D mode, further indicating that graphene of good structural quality was produced. The study also revealed that the lack of interfacial oxide correlates with superior properties of graphene. In order to evaluate electrical properties of graphene, its 2 × 2 cm² pieces were transferred onto SiO₂/Si substrates from Ge/Si wafers. The extracted sheet resistance and mobility values of transferred graphene layers were ∼1500 ± 100 Ω/sq and μ ≈ 400 ± 20 cm²/V s, respectively. The transferred graphene was free of metallic contaminations or mechanical damage. On the basis of results of DFT calculations, we attribute the high structural quality of graphene grown by CVD on Ge to hydrogen-induced reduction of nucleation probability, explain the appearance of graphene-induced facets on Ge(001) as a kinetic effect caused by surface step pinning at linear graphene nuclei, and clarify the orientation of graphene domains on Ge(001) as resulting from good lattice matching between Ge(001) and graphene nucleated on such nuclei.

3,4-Dihydro-2-Alkoxy-6-Benzyl-4-Oxopyrimidines (DABOs): A New Class of Specific Inhibitors of Human Immunodeficiency Virus Type 1

A series of novel 3,4-dihydro-6-benzyl-4-oxopyrimidines substituted at both the C-5 and the C-2 positions were synthesized as potential anti-HIV agents. Preparation of the title compounds was achieved by condensation of O-methylisourea with methyl 2-alkyl-4-phenylacetylacetate and subsequent displacement of the methoxy group by reaction with a series of linear, ramified and cyclic alkoxy groups containing from three to six carbon units. Methyl 2-alkyl-4-phenylacetylacetates were prepared by alkylation of methyl 4-phenylacetylacetate, which was obtained starting from Meldrum's acid and phenacetyl chloride. Acid hydrolysis of 3,4-dihydro-6-benzyl-2-methoxy-4-oxopyrimidines furnished the corresponding 1,2,3,4-tetrahydro-6-benzyl-2,4-dioxopyrimidines. In acutely infected MT-4 cells, compounds 3e, 3o, 3q and 3r showed an anti-HIV-1 activity as potent and/or selective as HEPT and ddl. Unlike HEPT, the replacement of a methyl for an hydrogen atom at position C-5 of 3,4-dihydro-2-alkoxy-6-benzyl-4-oxopyrimidines (DABOs) did not abolish the antiviral activity, as well as the substitution of the C-5 methyl for an ethyl group did not increase the potency. However, similarly to HEPT and its derivatives, DABOs targeted the HIV-1 reverse transcriptase and neither inhibited the multiplication of HIV-2 in acutely infected MT-4 cells, nor that of HIV-1 in chronically infected H9/IIIB cells.

Methyl-2-Thienylketopolymethyleneoxyphenyl Derivatives of Alkyl-Substituted 4,5-Dihydro-Oxazoles with Anti-Human Picornavirus Activity

The synthesis of 5-methyl-2-thienylketopolymethylene oxyphenyl 4,5-dihydro-2-(alkyl)oxazoles was accomplished by the assembly of two synthones, namely 1-(5-methyl-2-thienyl)-7-hydroxy-1-heptanone (or 1-(5-methyl-2-thienyl)-5-chloro-1-pentanone) and 4-[4,5-dihydro(alkyl)oxazol-2-yl]phenol, in the presence of diethyl azodicarboxylate(DEAD)-triphenyl phosphine (or sodium iodide and anhydrous potassium carbonate). Eighteen new disoxaril analogues were synthesized by the above procedure and tested in vitro against several rhino and enteroviruses. With a few exceptions, all test derivatives were more potent than WIN 51711 when assayed against HRV-14, and as potent as WIN 51711 against HRV-2, but none of them inhibited the other HRV serotypes. Among the various derivatives, two compounds showed the same wide spectrum activity of WIN 51711 against several rhino, and enteroviruses, but were at least 10-fold less toxic.

Synthesis and Antiviral Activity of New 3,4-Dihydro-2-Alkoxy-6-Benzyl-4-Oxopyrimidines (DABOs), Specific Inhibitors of Human Immunodeficiency Virus Type 1

3,4-Dihydro-2-alkoxy-6-benzyl-4-oxopyrimidines (DABOs) have emerged as non-nucleoside inhibitors of human immunodeficiency virus type 1 [Artico et al. (1993), Antiviral Chem Chemother 4: 361-368]. With a view to increasing their potency, a new series of DABO derivatives, differently substituted at positions C-2 and/or C-5 of the pyrimidine ring and 3′ or 3′,5′ of the benzyl moiety, have been synthesized. DABOs were prepared by reacting O-methylisourea with the appropriate methyl 2-alkyl-4-phenylacetylacetate, with formation of 3,4-dihydro-2-methoxy-6-arylmethyl-4-oxopyrimidines. Subsequent displacement of the methoxy group linked at the 2-position of the pyrimidine ring by treatment with alkoxy and cycloalkoxy potassium salts led to the required derivatives. In vitro, the most potent compounds were 12e and 12p, which had an EC50 of 0.8 μM and a selective index of 400.

Chronic stress and antidepressant induced changes in Hdac5 and Sirt2 affect synaptic plasticity

Changes in histone acetylation could contribute to the pathogenesis of depression and antidepressant therapy. Using the chronic social defeat stress (CSDS) model of depression and different antidepressant treatments we studied the regulation of histone deacetylases (Hdac׳s) and synaptic plasticity markers in the prefrontal cortex (PFC). Further, functional implication of identified Hdac׳s in brain plasticity was explored. Mice were exposed to CSDS (10 days) followed by saline or imipramine (4 weeks). PFC Hdac׳s mRNA abundance was studied and compared to human׳s. Further, protein expression of acetylated histones (AcH3 and AcH4), neuroplasticity markers (CREB and pro-BDNF) and selected Hdac׳s were analyzed. Moreover, other antidepressants (fluoxetine and reboxetine) and selective HDAC inhibitors were studied. CSDS increased Hdac5 and Sirt2 mRNA whereas repeated imipramine did the opposite. Accordingly, stress and imipramine induced opposite changes on AcH3, AcH4 and CREB expression. At protein level, CSDS upregulated nuclear fraction of Hdac5 and repeated imipramine and reboxetine increased its phosphorylated form (p-Hdac5), mainly located in the cytoplasm. Moreover, Sirt2 was downregulated by all monoaminergic antidepressants. Further, repeated treatment with the class IIa Hdac inhibitor MC1568 and the Sirt2 inhibitor 33i for three weeks increased synaptic plasticity in the prefrontal cortex. Our results suggest that Hdac5 and Sirt2 upregulation could constitute stable stress-induced neuronal adaptations. Noteworthy, the SIRT2 upregulation in depressed patients supports the interest of this target for therapeutic intervention. On the other hand, cytoplasmic Hdac5 export and Sirt2 downregulation induced by monoaminergic antidepressants could contribute to the well-known beneficial effects of antidepressants on brain plasticity.

High bandwidth, high responsivity waveguide-coupled germanium p-i-n photodiode

A novel waveguide-coupled germanium p-i-n photodiode is demonstrated which combines high responsivity with very high -3 dB bandwidth at a medium dark current. Bandwidth values are 40 GHz at zero bias and more than 70 GHz at -1 V. Responsivity at 1.55 µm wavelength ranges from 0.84 A/W at zero bias to 1 A/W at -1 V. Room temperature dark current density at -1 V is about 1 A/cm2. The high responsivity mainly results from the use of a new, low-loss contact scheme, which moreover also reduces the negative effect of photo carrier diffusion on bandwidth.

Technology modules from micro- and nano-electronics for the life sciences

The capabilities of modern semiconductor manufacturing offer remarkable possibilities to be applied in life science research as well as for its commercialization. In this review, the technology modules available in micro- and nano-electronics are exemplarily presented for the case of 250 and 130 nm technology nodes. Preparation procedures and the different transistor types as available in complementary metal-oxide-silicon devices (CMOS) and BipolarCMOS (BiCMOS) technologies are introduced as key elements of comprehensive chip architectures. Techniques for circuit design and the elements of completely integrated bioelectronics systems are outlined. The possibility for life scientists to make use of these technology modules for their research and development projects via so-called multi-project wafer services is emphasized. Various examples from diverse fields such as (1) immobilization of biomolecules and cells on semiconductor surfaces, (2) biosensors operating by different principles such as affinity viscosimetry, impedance spectroscopy, and dielectrophoresis, (3) complete systems for human body implants and monitors for bioreactors, and (4) the combination of microelectronics with microfluidics either by chip-in-polymer integration as well as Si-based microfluidics are demonstrated from joint developments with partners from biotechnology and medicine. WIREs Nanomed Nanobiotechnol 2016, 8:355-377. doi: 10.1002/wnan.1367 For further resources related to this article, please visit the WIREs website.

PRMT1 arginine methyltransferase accumulates in cytoplasmic bodies that respond to selective inhibition and DNA damage

Protein arginine methyltransferases (PRMTs) are responsible for symmetric and asymmetric methylation of arginine residues of nuclear and cytoplasmic proteins. In the nucleus, PRMTs belong to important chromatin modifying enzymes of immense functional significance that affect gene expression, splicing and DNA repair. By time-lapse microscopy we have studied the sub-cellular localization and kinetics of PRMT1 after inhibition of PRMT1 and after irradiation. Both transiently expressed and endogenous PRMT1 accumulated in cytoplasmic bodies that were located in the proximity of the cell nucleus. The shape and number of these bodies were stable in untreated cells. However, when cell nuclei were microirradiated by UV-A, the mobility of PRMT1 cytoplasmic bodies increased their, size was reduced, and they disappeared within approximately 20 min. The same response occurred after γ-irradiation of the whole cell population, but with delayed kinetics. Treatment with PRMT1 inhibitors induced disintegration of these PRMT1 cytoplasmic bodies and prevented formation of 53BP1 nuclear bodies (NBs) that play a role during DNA damage repair. The formation of 53BP1 NBs was not influenced by PRMT1 over-expression. Taken together, we show that PRMT1 concentrates in cytoplasmic bodies, which respond to DNA injury in the cell nucleus, and to treatment with various PRMT1 inhibitors.

The Polycomb group (PcG) protein EZH2 supports the survival of PAX3-FOXO1 alveolar rhabdomyosarcoma by repressing FBXO32 (Atrogin1/MAFbx)

The Polycomb group (PcG) proteins regulate stem cell differentiation via the repression of gene transcription, and their deregulation has been widely implicated in cancer development. The PcG protein Enhancer of Zeste Homolog 2 (EZH2) works as a catalytic subunit of the Polycomb Repressive Complex 2 (PRC2) by methylating lysine 27 on histone H3 (H3K27me3), a hallmark of PRC2-mediated gene repression. In skeletal muscle progenitors, EZH2 prevents an unscheduled differentiation by repressing muscle-specific gene expression and is downregulated during the course of differentiation. In rhabdomyosarcoma (RMS), a pediatric soft-tissue sarcoma thought to arise from myogenic precursors, EZH2 is abnormally expressed and its downregulation in vitro leads to muscle-like differentiation of RMS cells of the embryonal variant. However, the role of EZH2 in the clinically aggressive subgroup of alveolar RMS, characterized by the expression of PAX3-FOXO1 oncoprotein, remains unknown. We show here that EZH2 depletion in these cells leads to programmed cell death. Transcriptional derepression of F-box protein 32 (FBXO32) (Atrogin1/MAFbx), a gene associated with muscle homeostasis, was evidenced in PAX3-FOXO1 RMS cells silenced for EZH2. This phenomenon was associated with reduced EZH2 occupancy and H3K27me3 levels at the FBXO32 promoter. Simultaneous knockdown of FBXO32 and EZH2 in PAX3-FOXO1 RMS cells impaired the pro-apoptotic response, whereas the overexpression of FBXO32 facilitated programmed cell death in EZH2-depleted cells. Pharmacological inhibition of EZH2 by either 3-Deazaneplanocin A or a catalytic EZH2 inhibitor mirrored the phenotypic and molecular effects of EZH2 knockdown in vitro and prevented tumor growth in vivo. Collectively, these results indicate that EZH2 is a key factor in the proliferation and survival of PAX3-FOXO1 alveolar RMS cells working, at least in part, by repressing FBXO32. They also suggest that the reducing activity of EZH2 could represent a novel adjuvant strategy to eradicate high-risk PAX3-FOXO1 alveolar RMS.

Liver function tests profile in cancer patients on cytotoxic chemotherapy: a preliminary report

AIMS AND OBJECTIVES

To assess liver function in Nigerian cancer patients undergoing cytotoxic chemotherapy, with a view to contributing to the existing literature and possibly making recommendations for better management of the affected patients in Nigerian hospitals.

PATIENTS AND METHODS

Serum levels of total bilirubin (TB), alanine amino transferase (ALT), aspartate amino transferase (AST), alkaline phosphatase (ALP), total protein (TP), albumin (ALB) and De Ritis ratio (AST/ALT) were determined in 50 cancer patients both before and after chemotherapy and 50 age- and sex-matched control individuals. The data obtained were analysed using Microsoft Office Excel 2003. Two-tailed student's t- test for matched samples and Pearson's linear correlation statistical methods were employed for the analyses.

RESULTS

The levels of serum ALT, AST, ALP and TB, ALB, TP and AST/ALT were significantly higher in cancer patients than in controls both before and after chemotherapy, with more pronounced elevations after chemotherapy. There were positive and significant correlations between cycles of chemotherapy and the serum liver function tests.

CONCLUSION

The findings from the present study conclude that there is slight difference when compared to controls in liver function test profile in cancer patients even before commencement of chemotherapy with a worsening of the profile of patients after chemotherapy. This difference in liver function also increases with the cycles of chemotherapy.

The mobile phone as a tool in improving cancer care in Nigeria

OBJECTIVE

The use of mobile phone as a tool for improving cancer care in a low resource setting.

METHODS

A total of 1176 oncology patients participated in the study. Majority had breast cancer. 58.4% of the patients had no formal education; 10.7 and 9.5% of patients had college or graduate education respectively. Two out of every three patients lived greater than 200 km from hospital or clinic. One half of patients rented a phone to call.

RESULTS

At 24 months, 97.6% (1132 patients) had sustained their follow-up appointments as against 19.2% (42 patients) who did not receive the phone intervention. 72.8% (14 102 calls) were to discuss illness/treatment. 14% of the calls were rated as emergency by the oncologist. 86.2% of patients found the use of mobile phone convenient/excellent/cheap. 97.6% found the use of the phone worthwhile and preferred the phone to traveling long distance to hospital/clinic. Also the patients felt that they had not been forgotten by their doctors and were been taken care of outside the hospital/clinic.

CONCLUSIONS

Low resource countries faced with the burden of cancer care, poor patient follow-up and poor psychosocial support can cash in on this to overcome the persistent problem of poor communication in their healthcare delivery. The potential is enormous to enhance the use of mobile phones in novel ways: developing helpline numbers that can be called for cancer information from prevention to treatment to palliative care. The ability to reach out by mobile phone to a reliable source for medical information about cancer is something that the international community, having experience with helplines, should undertake with colleagues in Africa, who are experimenting with the mobile phone potential.

Mechanisms of Heavy Oil Recovery by Low Rate Waterflooding

Abstract

At the conclusion of primary heavy oil production, significant volumes of oil still remain in the reservoir under depleted reservoir pressure. Waterfloods are often considered for additional oil recovery. It is accepted that conventional oil waterflooding theory is not applicable for heavy oil. However, there is a lack of understanding of how waterfloods should perform in these reservoirs, particularly after water breakthrough. In this study, waterfloods were performed at multiple rates in cores containing heavy oil and connate water. In some cores, oil was initially free of solution gas, and waterfloods were a primary recovery process. In other cores, waterfloods were performed after primary production. Experiments were performed in linear systems for a high-viscosity oil (11,500 mPa·s at 23°C), at different injection rates. The influence of viscous and capillary forces is studied in primary vs. secondary recovery systems. A common misconception is that capillary forces are negligible in heavy oil; however, this work shows that these forces are significant, and that water imbibition after water breakthrough can lead to improved oil recovery in both primary and secondary waterfloods.

Introduction

The Canadian deposits of heavy oil and bitumen are some of the largest in the world. Recent estimates by the Alberta Energy and Utilities Board(1) suggest that this resource could exceed 270 billion m³ in Alberta alone, with a significant portion of this oil located in reservoirs where energy-intensive thermal operations will not be economic. Heavy oil is a special class of this unconventional oil, which has viscosity ranging from 50 - 50,000 mPa·s (cp) and low API gravity. Heavy oil reservoirs are often high-porosity, high-permeability, unconsolidated sand deposits. Permeability of the sand averages in the range of 3D, but oil does not flow easily because of its high viscosity(2). The oil may contain dissolved solution gas at initial conditions; thus, a fraction of the oil can be recovered through solution gas drive. Primary production can recover around 5% of the oil in place(1), leaving significant oil volumes in the reservoir for potential secondary recovery.

Waterflooding is a common technique for secondary oil recovery in conventional oil reservoirs. In heavy oil systems, the extremely high oil viscosities lead to adverse mobility ratio conditions; thus, water will tend to "finger?? through the oil, and recoveries are expected to be extremely low(3,4). Despite the poor recoveries predicted theoretically, there have been numerous reports of heavy oil waterfloods performed in the literature(5-8). All of these studies report poor sweep efficiencies and low overall recovery. However, it is significant that in all cases some oil was still recovered, despite the highly adverse mobility ratios in the waterfloods.

Insights Into Non-Thermal Recovery of Heavy Oil

Abstract

Many heavy oil reservoirs contain oil that has some limited mobility under reservoir conditions. In these reservoirs, a small fraction of the oil-in-place can be recovered using the internal reservoir energy through heavy oil solution gas drive (primary production). An integral part of this process is the so-called 'foamy oil mechanism', whereby oil is produced as a gas-in-oil dispersion. At the end of primary production, the bulk of the oil is still in place, while the natural energy of the reservoir has been depleted. This remaining oil is still mostly continuous and presents a valuable target for further recovery. Many of these reservoirs are relatively small or thin, or may be contacted by overlying gas or underlying water. As such, they are poor candidates for thermal oil recovery methods, so any additional oil recovery after primary production must be non-thermal. In this work, we present experimental results of foamy oil depletion at two different length scales and varying depletion rates. Tests were conducted in the absence of sand production, and the results from the depletion experiments are interpreted in terms of viscous forces. At the conclusion of primary recovery, the potential for further non-thermal exploitation of these reservoirs is explored. Results for waterflooding and chemical flooding are presented, demonstrating the viability of these techniques for heavy oil EOR. Several displacement mechanisms are identified through the secondary and tertiary processes that contribute to significant (although potentially slow) incremental recovery of heavy oil.

Introduction

Many countries have heavy oil reservoirs. Canada and Venezuela in particular contain some of the largest heavy oil and bitumen resources in the world. Rising energy demands, coupled with a decline in conventional oil reserves, has led to increased interest in heavy oil recovery in recent years. The size of these heavy oil deposits is considerable, and with volatile crude oil prices making it difficult to produce from some higher viscosity bitumen reservoirs, production of heavy oil could potentially be very important in years to come. Understanding the mechanisms by which heavy oil can be displaced in reservoirs is crucial to the successful recovery of this resource base.

Heavy oil can be defined as a class of oils with viscosity ranging from 50 mPa.s up to around 50,000 mPa.s. This oil has limited mobility under reservoir temperature and pressure, and Darcy's Law predicts that the oil can flow slowly under high applied pressure gradients. However, it has been observed that in these reservoirs, solution gas drive leads to significantly higher rates and recoveries than what was expected by conventional understanding of gas-oil relative permeability behaviour(1). This behaviour, first reported in Canadian heavy oil, has since been observed in many other reservoirs around the world including South America, China and Albania. Investigations into the causes of this abnormal, but fortuitous, primary production response have been the focus of many publications in the past 25 years.

The recovery from primary production in heavy oil reservoirs may be as high as 20%(2), but is usually lower.

Heavy Oil Waterflooding: Effects of Flow Rate and Oil Viscosity

Abstract

Many countries in the world contain significant heavy oil deposits. In reservoirs with viscosity over several hundred mPa's, waterflooding is not expected to be successful due to the extremely high oil viscosity. However, in many smaller, thinner reservoirs, or reservoirs at the conclusion of cold production, thermal enhanced oil recovery methods will not be economic. Waterfloods are relatively inexpensive and easy to control; therefore, they will still often be employed in high viscosity heavy oil fields. This paper presents experimental findings of waterflooding in laboratory sandpacks for two high viscosity heavy oils of 4,650 mPa.s and 11,500 mPa.s at varying water injection rates. The results of this work show that capillary forces, which are often neglected due to the high oil viscosity, are important even in heavy oil systems. At low injection rates, water imbibition can be used to stabilize the waterflood and improve oil recovery. Waterflooding can therefore be a viable non-thermal enhanced oil recovery technology, even in fields with very high oil viscosity.

Introduction

Although conventional oil reserves are declining in many countries, the global energy demand is still increasing. As a result, the industry focus is now shifting towards unconventional oil resources, such as the oil sands in countries like Canada and Venezuela. The size of this resource base is immense, but the production of high viscosity crude oil carries its own unique challenges.

Heavy oil is a special class of this unconventional oil, and has viscosities ranging from 50 to 50,000 mPa.s. Heavy oil reservoirs are often found in highly porous, highly permeable, unconsolidated sand deposits. At reservoir conditions, the oil may contain dissolved solution gas; thus, some oil can be initially recovered using the energy from heavy oil solution gas drive. At the end of primary production, however, a significant amount of oil still exists for potential secondary recovery. Many of these reservoirs are small and thin or were disturbed during primary production, making them poor candidates for expensive thermal enhanced oil recovery strategies. In times of uncertain commodity pricing, it is beneficial to examine the potential for relatively inexpensive, non-thermal oil recovery techniques.

Waterflooding is often employed, at least initially, in heavy oil reservoirs, both along with or after primary recovery in order to re-pressurize the reservoir and displace oil to producing wells. In these applications, it is very important to understand the forces that are present in the reservoir and how they can be used to properly design the waterflood. Specifically, proper design and maintenance of waterfloods requires comprehension of how viscous oil can be displaced by water, and how oil recovery can be optimized. This work presents the results for water injection into laboratory sandpacks containing gas-free heavy oil of varying viscosity. The responses for different waterfloods are compared in order to investigate the mechanisms by which heavy oil can be recovered by water injection.

Theory

Waterflooding of oil reservoirs is a well-recognized technique for oil recovery after primary production. In conventional oil, waterflooding theory has been well documented(1).

Salermide, a Sirtuin inhibitor with a strong cancer-specific proapoptotic effect

Sirtuin 1 (Sirt1) and Sirtuin 2 (Sirt2) belong to the family of NAD+ (nicotinamide adenine dinucleotide-positive)-dependent class III histone deacetylases and are involved in regulating lifespan. As cancer is a disease of ageing, targeting Sirtuins is emerging as a promising antitumour strategy. Here we present Salermide (N-{3-[(2-hydroxy-naphthalen-1-ylmethylene)-amino]-phenyl}-2-phenyl-propionamide), a reverse amide with a strong in vitro inhibitory effect on Sirt1 and Sirt2. Salermide was well tolerated by mice at concentrations up to 100 muM and prompted tumour-specific cell death in a wide range of human cancer cell lines. The antitumour activity of Salermide was primarily because of a massive induction of apoptosis. This was independent of global tubulin and K16H4 acetylation, which ruled out a putative Sirt2-mediated apoptotic pathway and suggested an in vivo mechanism of action through Sirt1. Consistently with this, RNA interference-mediated knockdown of Sirt1, but not Sirt2, induced apoptosis in cancer cells. Although p53 has been reported to be a target of Sirt1, genetic p53 knockdowns showed that the Sirt1-dependent proapoptotic effect of Salermide is p53-independent. We were finally able to ascribe the apoptotic effect of Salermide to the reactivation of proapoptotic genes epigenetically repressed exclusively in cancer cells by Sirt1. Taken together, our results underline Salermide's promise as an anticancer drug and provide evidence for the molecular mechanism through which Sirt1 is involved in human tumorigenesis.

Porosity Distributions in Carbonate Reservoirs Using Low-Field NMR

Abstract

Alberta contains significant deposits of oil and gas in carbonate formations. Carbonates tend to have fairly tight matrix structures, resulting in low primary porosity and permeability. Laboratory characterization of carbonate properties is a slow and tedious process, however, core data is often collected in order to augment and tune logging tool predictions. In this application, having a good understanding of carbonate pore systems at the core analysis level is key to proper reservoir characterization. Low-field NMR is an emerging technology that shows great promise for rock characterization measurements. In this paper, low-field NMR technology is investigated for determining primary and secondary porosity through the interpretation of NMR spectra. This data was also used to establish the bound and mobile fluid distributions existing in the porous medium.

The data set for this experimental work consists of a large collection of core samples from various fields in Alberta and Saskatchewan. CT data were analyzed to obtain the primary and secondary porosity fractions, which were used to find corresponding NMR cutoff values that separate the NMR spectra into primary and secondary porosity.

A distinct relationship was observed between the primary porosity fraction and the irreducible water saturation, Swi. The fraction of NMR amplitude in the last peak of the NMR spectra can also be correlated to CT secondary porosity. Another important relationship observed is that the geometric mean relaxation time of the last NMR peak correlates well with the cutoff between primary and secondary porosity. The bound and mobile fluid distributions are generally distinguished through the identification of T2cutoff values. A correlation was found to predict T2cutoff for this wide range of samples.

This study shows that information from the fully saturated NMR spectrum can be used to estimate primary and secondary porosity fractions in carbonates, as well as bound and mobile fluid fractions.

Introduction

Porosity of carbonates is a complex problem that has had only limited attention in the literature(1). In general, carbonate porosity is divided into primary and secondary porosity. These different types of porosity are not easily distinguishable unless the primary pores and the diagenesis processes that occurred are studied(1). Despite these difficulties, it is very important to recognize and attempt to quantify the different porosity types and mobile/immobile fluid fractions in carbonates in order to help in developing carbonate reservoirs and to estimate the pore connections and recovery efficiency in these reservoirs.

As various researchers have found, Nuclear Magnetic Resonance (NMR) can capture pore size information of the porous media(2–4). Thus, in theory, it describes both the primary and secondary porosity. However, separating the signal into different porosity components remains a daunting task. Part of this difficulty arises from the fact that there is no clear distinction between primary and secondary pore size distributions, as they overlap with each other.

Chang et al.(3) have previously tried to separate the signal of vugs in NMR response. In carbonates, however, even the definition of vugs can be quite different. Chang et al.(3) used the term vugs to describe cavities that are formed in the matrix by diagenesis, with sizes ranging from about 100 μm to cavern size.

Identification and sequence analysis of discordant phenotypes between AmpFlSTR SGM Plus and PowerPlex 16

During duplicate analysis of buccal swabs from 1,377 individuals with 2 commercial short tandem repeat (STR) kits, we observed 8 discordant phenotypes with SGM Plus (SGM, second generation multiplex) for the STRs THO1 (2), vWA (4) and D18S51 (2), and 1 discrepancy with PowerPlex 16 for D18S51. One individual even showed two discrepancies (vWA and THO1) for SGM Plus. In each case, the difference observed was due to the non-amplification or allele dropout of the second allele in a heterozygous genotype. Sequence analysis revealed each time the presence of a mutation that probably coincided with the primer-binding site. Primer-binding site mutations for vWA and D18S51 have been reported previously, while the mutation for THO1 (C-to-T substitution at position 1286 of GenBank sequence D00269) is reported here for the first time. While the frequency of these silent alleles remains low (0.58% in our study), it is suggested that appropriate measures should be taken for database comparisons and that allelic dropout should be further investigated by sequence analysis and be reported to the forensic community.

Synthesis and biological evaluation of 2-, 3-, and 4-acylaminocinnamyl-N-hydroxyamides as novel synthetic HDAC inhibitors

A new series of 2-, 3-, and 4-acylaminocinnamyl-N-hydroxyamides 1-3 have been prepared, and their anti-HDAC (against maize HD2, HD1-B, and HD1-A enzymes) activities have been assessed. Cinnamyl-hydroxyamides bearing acylamino substituents at the C2 position of the benzene ring (compounds 1a-g) showed very low HDAC inhibiting activities, with IC(50) values in the high micromolar range. By shifting the same acylamino groups from C2 to C3 (compounds 2a-g) as well as C4 (compounds 3a-f) position of the benzene ring, a number of highly potent HDAC inhibitors have been obtained. In the anti-HD2 assay 3c (IC(50) = 11 nM) was the most potent compound, being >11600-, 4.5-, and 10-fold more potent than sodium valproate, SAHA, and HC-toxin, respectively, and showing the same activity as trapoxin. HD1-B and HD1-A assays have been performed to screen the inhibitory action of 1-3 against mammalian class I (HD1-B) and class II (HD1-A) HDAC homologous enzymes. From the corresponding IC(50) data, a selectivity ratio has been calculated. In general, compounds 1-3 showed no or little selectivity towards the class II homologue HD1-A, the most selective being 2a with class II selectivity ratio = 4.3. About the inhibitory potency, the 4-(2-naphthoylamino)cinnamyl-N-hydroxyamide 3f showed the highest inhibiting effect against the two enzymes (IC(50-HD1-B) = 36 nM; IC(50-HD1-A) = 42 nM). Selected 2 and 3 compounds will be evaluated to determine their antiproliferative and cyto differentiating activities on HL-60 cells.

Computer technology and the surgeon: what the resident needs to know

BACKGROUND

Computer technology is now a well established resource in medicine and medical sciences. Surgery in developed countries has taken great advantage of this resource. This review is intended to highlight important aspects of computers in surgery and also encourages surgeons in Nigeria to acquaint themselves with its influences.

METHODS

Publications from local and international journals as well as standard surgical texts were reviewed.

RESULTS

The role of computers in surgery spans the areas of patient care, training, research, communication as well as surgical administration. Though a compliment to the surgeon, it has its problems including overwhelming information requiring careful scrutiny; computer fraud, hacking and viruses; copyright laws; the 'threat' of a well-informed patient population; and the risk of over dependence. Surgery in Nigeria and most of African is yet to maximize its benefits.

CONCLUSION

The application of computers in surgery will in the near future make surgical knowledge and practice become more simplified and less time with increased productivity will be required even for highly technical procedures.

Field evaluation of anthelmintic drug sensitivity using in vitro egg hatch and larval motility assays with Necator americanus recovered from human clinical isolates

A field-applicable assay for testing anthelmintic sensitivity is required to monitor for anthelmintic resistance. We undertook a study to evaluate the ability of three in vitro assay systems to define drug sensitivity of clinical isolates of the human hookworm parasite Necator americanus recovered from children resident in a village in Madang Province, Papua New Guinea. The assays entailed observation of drug effects on egg hatch (EHA), larval development (LDA), and motility of infective stage larvae (LMA). The egg hatch assay proved the best method for assessing the response to benzimidazole anthelmintics, while the larval motility assay was suitable for assessing the response to ivermectin. The performance of the larval development assay was unsatisfactory on account of interference caused by contaminating bacteria. A simple protocol was developed whereby stool samples were subdivided and used for immediate egg recovery, as well as for faecal culture, in order to provide eggs and infective larvae, respectively, for use in the egg hatch assay and larval motility assay systems. While the assays proved effective in quantifying drug sensitivity in larvae of the drug-susceptible hookworms examined in this study, their ability to indicate drug resistance in larval or adult hookworms remains to be determined.

3-(1H-Pyrrol-2-yl)-2-oxazolidinones as Novel Monoamine Oxidase Type A Inhibitors

A novel series of 5-substituted-3-(1H-pyrrol-2-yl)-2-oxazolidinones 2a-s has been described as pyrrole analogues of toloxatone and befloxatone, two phenyl-oxazolidinones active as anti-MAO agents and used in antidepressant therapy. Tested against MAO-A and MAO-B enzymes, the majority of 2a-s show highly potent inhibitory effect against the A isoform of the enzyme, with Ki values in the range 0.52-0.004 microM, whilst their anti-MAO-B activity is considerably lower (Ki = >100-0.5 microM). Structurally, 2a-s differs for the substituent inserted at the C5 position of the 2-oxazolidinone ring (hydroxymethyl (2a-d), methoxymethyl (2e-h), azidomethyl (2i-l), methylaminomethyl (2m-p), and aminomethyl (2q-s)), and the size of the alkyl chain at the pyrrole N1 position (methyl, ethyl, allyl, or benzyl). As a rule, apart from the C5 substitution, the bulkier is the alkyl group at the pyrrole-N1, the lower is the anti-MAO-A activity of the compounds, being the N1-methyl derivatives 2a, 2e, 2i, and 2q among the most potent (K(iMAO-A) = 0.087-0.004 microM) and A-selective (A-selectivity ratio: >11,111-41) compounds in this series. Exceptions are represented by the N1-benzyl derivative 2d (K(iMAO-A) = 0.009 microM) and the N1-allylpyrrole 2o (K(iMAO-A) = 0.04 microM). In comparison with the reference drugs, these highly active derivatives are more potent than toloxatone, slightly less potent than befloxatone, and several times more A-selective than both the references. Such results indicate that 2a-s may represent a new promising series of antidepressant agents.

Synthesis and biological evaluation of enantiomerically pure pyrrolyl-oxazolidinones as a new class of potent and selective monoamine oxidase type A inhibitors

Due to the key role played by monoamine oxidases (MAOs) in the metabolism of neurotransmitters, MAO inhibitors (MAOIs) represent an useful tool for the treatment of several neurological diseases. Among selective MAOIs, MAO-A inhibitors (e.g. clorgyline) are used as antidepressant and antianxiety drugs and are claimed to protect neuronal cells against apoptosis, and selective MAO-B inhibitors (e.g. L-deprenyl) can be used in the treatment of Parkinson's disease either alone or in combination with L-DOPA. However, they engender covalent bonds with the active site of the enzyme and induce irreversible inhibition; moreover, they tend to lose their initial selectivity at high dosages or with repeated administrations. Phenyloxazolidinones belong to third-generation-MAOIs, characterized by a selective and reversible inhibition of the enzyme. Among these molecules, the most representative are toloxatone and befloxatone, two selective and reversible MAO-A inhibitors used in therapy as antidepressant drugs. Going on our searches on CNS potentially active compounds containing a pyrrole moiety we prepared 3-(1H-pyrrol-1-yl)-2-oxazolidinones (1) and isomeric 3-(1H-pyrrol-2-and -3-yl)-2-oxazolidinones (2 and 3) as anti-MAO agents. Such derivatives resulted selective and reversible MAO-A inhibitors. The most potent compound is (R)-5-methoxymethyl-3-(1H-pyrrol-1-yl)-2-oxazolidinone (1b), endowed with very high potency (K(iMAO-A) = 4.9 nM) and A-selectivity (A-selectivity = 10,200, about 116-fold greater than that of befloxatone).

DABOs as candidates to prevent mucosal HIV transmission

Worldwide, the heterosexual route is the prevalent mode of transmission of AIDS; therefore, demands have been raised for measures that block sexual spreading of the HIV infection. Development of microbicides for topical use may represent an efficacious alternative to condoms. Several approaches are being investigated. Besides surfactants, which directly act on the virus particle, and measures that enhance natural defence mechanisms, promising new candidates appear to be drugs that block the early steps of HIV multiplication. We describe herein a long-term assay which enables the establishment of whether the above drugs reversibly (virustatic action) or irreversibly (virucidal action) inhibit HIV-1 multiplication, thus allowing screening for effective and potent microbicides. We validated our assay with nucleoside (NRTIs) and non-nucleoside reverse transcriptase inhibitors (NNRTIs). Following a chronic treatment, the NRTIs tested (didanosine, zalcitabine, stavudine and lamivudine) simply delayed the viral breakthrough with respect to infected, untreated controls. Under the same experimental conditions, non-nucleoside reveres transcriptase inhibitors (NNRTIs), such as MKC-442, alphaAPA, nevirapine, efavirenz and 3,4-dihydro-2-alkoxy-6-benzyl-4-oxopyrimidines (DABOs) MC 1047 and MC 1220 suppressed HIV-1 replication for the entire experimental period (40 days). When cell culture samples were evaluated for the presence of infectious virus, p24 antigen and viral DNA sequences, none of them was detected up to day 40 post-infection (p.i.). Identical results were obtained after a treatment with the above NNRTIs limited to the first 4 days p.i. Under more selective experimental conditions, that is drug treatments limited to the first 4 h p.i., nevirapine and efavirenz proved to be virustatic; in fact, viral breakthrough ensued shortly after their removal from the culture medium. Conversely, DABO MC 1220 was endowed with potent virucidal activity; in fact, at 3.5 microM it was able to suppress HIV-1 multiplication in cultures acutely infected with a very high multiplicity of infection (5 CCID50/cell), thus allowing exponential cell multiplication as in uninfected cultures for the next 40 days.

Sulfogalactosylglycerolipid is involved in human gamete interaction

Recent results from our laboratory have revealed the role of sulfogalactosylglycerolipid (SGG) in mouse sperm-zona pellucida (ZP) binding. In this report, we demonstrated the presence of SGG in Percoll-gradient centrifuged (PGC) human sperm by high performance thin layer chromatography with orcinol and Azure A staining, specific for glycolipids and sulfolipids, respectively. SGG in human PGC sperm was quantified by its affinity to Azure A to be 12-15 mol% of sperm lipids. Indirect immunofluorescence revealed that SGG existed on both live and aldehyde fixed human sperm in the head region. Pretreatment of human PGC sperm with affinity purified antiSGG Fab markedly inhibited sperm binding to the ZP in a concentration dependent manner, without any changes in the spontaneous acrosome rate or sperm motility parameters. Fluorescently labeled SGG liposomes also bound uniformly to isolated human ZP, while fluorescently labeled galactosylglycerolipid (GG, SGG's parental lipid) or phosphatidylserine (PS, negatively charged like SGG) liposomes did not. All of these results suggested the role of human sperm SGG in ZP binding.

Structure-based design, synthesis, and biological evaluation of conformationally restricted novel 2-alkylthio-6-[1-(2,6-difluorophenyl)alkyl]-3,4-dihydro-5-alkylpyrimidin-4(3H)-ones as non-nucleoside inhibitors of HIV-1 reverse transcriptase

5-Alkyl-2-(alkylthio)-6-(2,6-difluorobenzyl)-3,4-dihydropyrimidin-4(3H)-ones (S-DABOs, 2) have been recently described as a new class of human immunodeficiency virus type 1 (HIV-1) non-nucleoside reverse transcriptase (RT) inhibitors (NNRTIs) active at nanomolar concentrations (Mai, A. et al. J. Med. Chem. 1999, 42, 619-627). In pursuing our lead optimization efforts, we designed novel conformationally restricted S-DABOs, 3, featuring a methyl at the benzylic carbon (Y = Me) and at the pyrimidine 5-position (R = Me). Conformational analyses and docking simulations suggested that the presence of both methyls would significantly reduce conformational flexibility without compromising, in the R enantiomers, the capability of fitting into the RT non-nucleoside binding pocket. To develop structure-activity relationships, we prepared several congeners of type 3 belonging to the thymine (R = Me) and uracil (R = H) series, featuring various 2-alkylthio side chains (X = Me, i-Pr, n-Bu, i-Bu, s-Bu, c-pentyl, and c-hexyl) and aryl moieties different from the 2,6-difluorophenyl (Ar = phenyl, 2,6-dichlorophenyl, 1-naphthyl). Moreover, alpha-ethyl derivatives (Y = Et) were included in the synthetic project in addition to alpha-methyl derivatives (Y = Me). All of the new compounds were evaluated for their cytotoxicity and anti-HIV-1 activity in MT-4 cells, and some of them were assayed against highly purified recombinant wild-type HIV-1 RT using homopolymeric template primers. The results were expressed as CC(50) (cytotoxicity), EC(50) (anti-HIV-1 activity), SI (selectivity, given by the CC(50)/EC(50) ratio), and IC(50) (RT inhibitory activity) values. In the 2,6-difluorobenzylthymine (R = Me) series, methylation of the benzylic carbon improved anti-HIV-1 and RT inhibitory activities together with selectivity. Compound 3w (Ar = 2,6-F(2)-Ph, R = Y = Me, X = c-pentyl) turned out the most potent and selective among the S-DABOs reported to date (CC(50) > 200 microM, EC(50) = 6 nM, IC(50) = 5 nM, and SI > 33 333). Assays performed on the pure enantiomer (+)-3w, much more active than (-)-3w, yielded the following results: CC(50) > 200 microM, EC(50) = 2 nM, IC(50) = 8 nM, and SI > 100 000, under conditions wherein MKC-442 was less active and selective (CC(50) > 200 microM, EC(50) = 30 nM, IC(50) = 40 nM, SI > 6666). The 2,6-difluorophenylethylthymines (R = Me) were generally endowed with higher potency compared with the uracil counterparts (R = H). In the 2,6-difluorophenyl series the best and the least performant 2-alkylthio side chains were the 2-c-pentylthio and the 2-methylthio, respectively. When the methyl at the benzylic carbon was replaced by an ethyl, activity was retained or decreased slightly, thus suggesting that the dimensions of the cavity within the RT hosting this substituent would not be compatible with groups larger than ethyl. Aryl moieties different from the 2,6-difluorophenyl (phenyl, 1-naphthyl, 2,6-dichlorophenyl) were generally detrimental to activity, consistent with a favorable electronic effect exerted by the 2,6-fluorines on a putative charge-transfer interaction between the aromatic moieties of the inhibitor and Tyr188.

3-(4-aroyl-1H-pyrrol-2-yl)-N-hydroxy-2-propenamides, a new class of synthetic histone deacetylase inhibitors

Novel 3-(4-aroyl-2-pyrrolyl)-N-hydroxy-2-propenamides are disclosed as a new class of histone deacetylase (HDAC) inhibitors. Three-dimensional structure-based drug design and conformational analyses into the histone deacetylase-like protein (HDLP) catalytic core suggested the synthesis and biological evaluation of compounds 7a-h. Experimental pK(i) values are in good agreement with VALIDATE predicted pK(i) values of new derivatives. All compounds 7a-h show HDAC inhibitory activity in the micromolar range, with 7e as the most potent derivative (IC(50) = 1.9 microM). The influence of the 4'-substituent in the aroyl moiety is not significant for the inhibitory activity, as all compounds 7a-g show IC(50) values between 1.9 and 3.9 microM. Otherwise, the unsaturated chain linking the pyrrole ring to the hydroxamic acid group is clearly important for the anti-HDAC activity, the saturated analogue 7h being 10-fold less active than the unsaturated counterpart 7a.

Reversal of established delayed type hypersensitivity reactions following therapy with IL-4 or antigen-specific Th2 cells

Delayed-type hypersensitivity reactions (DTHR) are mediated by IFN-gamma-producing CD4+ (Th1) or CD8+ T cells (Tc1) and can be prevented by steering T cells toward an IL-4-producing Th2 or Tc2 phenotype. It is currently accepted that T cells can be directed toward a Th2 or Tc2 phenotype only during the initiation of an immune response. Once established, the cytokine pattern of immune reactions is believed to be stable. Therefore, inhibition of DTHR by the induction of Th2/Tc2 responses, termed immune deviation, is considered only as a prevention but not as a therapy of harmful DTHR. Here we demonstrate that therapeutic immune deviation can reverse established contact hypersensitivity (CHS), a Th1/Tc1-mediated DTHR. One or two weeks after induction of CHS, mice received either a single cycle of IL-4 therapy or adoptive transfer of antigen-specific Th2 cells. This treatment generated a novel state of immunity that provided long-lasting protection against tissue destruction and neutrophil recruitment during subsequent antigen exposures. Therapeutic immune deviation of established CHS was dependent on CD4+ T cells and the induction of endogenous IL-4 synthesis. Thus, a population of immunoregulatory Th2 cells persists during advanced inflammatory responses that can be used for therapeutic deviation of established DTHR.

Cell-cell signaling and adhesion in phagocytosis and early development of Dictyostelium

Cell-cell signaling and adhesion regulate transition from the unicellular to the multicellular stage of development in the cellular slime mold Dictyostelium. Essential gene networks involved in these processes have been identified and their interplay dissected. Heterotrimeric G protein-linked signal transduction plays a key role in regulating expression of genes mediating chemotaxis or cell adhesion, as well as coordinating actin-based cell motility during phagocytosis and chemotaxis. Two classes of cell adhesion molecules, one cadherin-like and the second belonging to the IgG superfamily, contribute to the strength of adhesion in Dictyostelium aggregates. The developmental role of genes involved in motility and adhesion, and their degree of redundancy, have been re-assessed by using novel developmental assay conditions which are closer to development in nature.

Chiral resolution and molecular modeling investigation of rac-2-cyclopentylthio-6-[1-(2,6-difluorophenyl)ethyl]-3,4-dihydro-5-methylpyrimidin-4(3H)-one (MC-1047), a potent anti-HIV-1 reverse transcriptase agent of the DABO class

rac-2-Cyclopentylthio-6-[1-(2,6-difluorophenyl)ethyl]-3,4-dihydro-5-methylpyrimidin-4(3H)-one (MC-1047) is a potent inhibitor of HIV-1 multiplication in acutely infected cells. MC-1047 racemate has been resolved by chiral HPLC using, as chiral stationary phase (CSP), a commercially available (R,R)-Whelk-01 column. The optical purity and the circular dichroism (CD) of the two resolved enantiomers were determined and their biological activities tested in in vitro assays. Molecular modeling inspection of the binding of (R) and (S) enantiomers to the non-nucleoside binding site (NNBS) of reverse transcriptase (RT) using the defined model of F(2)-S-DABO/RT complex indicates the (R) enantiomer as the more active isomer.

Structure-activity relationship studies on new DABOS: effect of substitutions at pyrimidine C-5 and C-6 positions on anti-HIV-1 activity

Several 5-alkyl, 5-alkenyl, 5-iso-alkyl, 5-halo, 5-aminomethyl and 5-carboxy derivatives of S-DABOs (dihydro-alkyl (or cyclo-alkyl)thio-benzyloxopyrimidines), DATNOs (dihydro-alkylthionaphthylmethyl-oxopyrimidines) and F2-S-DABOs (dihydro-alkyl (or cyclo-alkyl)thio-2,6-difluorobenzyl-oxopyrimidines) have been prepared and tested as anti-HIV-1 agents. S-DABO derivatives bearing at C-6 position monosubstituted phenylmethyl or heteroarylmethyl units have also been synthesized. 2-Alkylthio-3,4-dihydropyrimidin-4(3H)-one derivatives of F2-S-DABO series bearing small alkyl groups at C-5 proved to be potent inhibitors of HIV-1 replication in vitro with selectivity indexes ranging from 250 to >2,500.