TIA-1 is a translational silencer that selectively regulates the expression of TNF-alpha

TIA-1 and TIAR are related proteins that bind to an AU-rich element (ARE) in the 3' untranslated region of tumor necrosis factor alpha (TNF-alpha) transcripts. To determine the functional significance of this interaction, we used homologous recombination to produce mutant mice lacking TIA-1. Although lipopolysaccharide (LPS)-stimulated macrophages derived from wild-type and TIA-1(-/-) mice express similar amounts of TNF-alpha transcripts, macrophages lacking TIA-1 produce significantly more TNF-alpha protein than wild-type controls. The half-life of TNF-alpha transcripts is similar in wild-type and TIA-1(-/-) macrophages, indicating that TIA-1 does not regulate transcript stability. Rather, the absence of TIA-1 significantly increases the proportion of TNF-alpha transcripts that associate with polysomes, suggesting that TIA-1 normally functions as a translational silencer. TIA-1 does not appear to regulate the production of interleukin 1 beta, granulocyte-macrophage colony-stimulating factor or interferon gamma, indicating that its effects are, at least partially, transcript specific. Mice lacking TIA-1 are hypersensitive to the toxic effects of LPS, indicating that this translational control pathway may regulate the organismal response to microbial stress.

Process development for the removal of lead and chromium from aqueous solutions using red mud--an aluminium industry waste

Red mud, an aluminium industry waste, has been converted into an inexpensive and efficient adsorbent and used for the removal of lead and chromium from aqueous solutions. Effect of various factors on the removal of these metal ions from water (e.g. pH, adsorbent dose, adsorbate concentration, temperature, particle size, etc.) has been studied and discussed. The effect of presence of other metal ions/surfactants on the removal of Pb2+ and Cr6+ has also been studied. The material exhibits good adsorption capacity and the data follow both Freundlich and Langmuir models. Thermodynamic parameters indicate the feasibility of the process. Kinetic studies have been performed to understand the mechanism of adsorption. Dynamic modelling of lead and chromium removal on red mud has been undertaken and found to follow first-order kinetics. The rate constant and mass transfer coefficient have also been evaluated under optimum conditions of removal in order to understand the mechanism. Column studies have been carried out to compare these with batch capacities. The recovery of Pb2+ and Cr6+ and chemical regeneration of the spent column have also been tried.

Cytokine production by maternal lymphocytes during normal human pregnancy and in unexplained recurrent spontaneous abortion

It has been proposed that successful pregnancy is a T helper 2-type phenomenon, and that T helper (Th)1-type reactivity is deleterious to pregnancy. The objective of this study was to compare the concentrations of Th1 and Th2 cytokines produced by peripheral blood mononuclear cells from women undergoing unexplained recurrent spontaneous abortion (RSA) with those produced during normal pregnancy at a similar gestational stage. The control group consisted of 24 women with a history of successful pregnancies and the abortion group comprised of 23 women with a history of unexplained RSA. Blood from the control group was obtained at the end of the first trimester as gestational age controls for the abortion group from whom blood was collected at the time of abortion. Phytohaemagglutinin-stimulated peripheral blood cell culture supernatants were analysed for concentrations of cytokines. Significantly higher concentrations of Th2 cytokines were produced by the first trimester normal group than by the RSA group, while significantly higher concentrations of Th1 cytokines were produced by the abortion group as compared to first trimester normal pregnancy, indicating a distinct Th2-bias in normal pregnancy and a Th1-bias in unexplained RSA.

A phase II trial of the oral mTOR inhibitor everolimus in relapsed aggressive lymphoma

The phosphatidylinositol 3-kinase signal transduction pathway members are often activated in tumor samples from patients with non-Hodgkin's lymphoma (NHL). Everolimus is an oral agent that targets the raptor mammalian target of rapamycin (mTORC1). The goal of this trial was to learn the antitumor activity and toxicity of single-agent everolimus in patients with relapsed/refractory aggressive NHL. Patients received everolimus 10 mg PO daily. Response was assessed after two and six cycles, and then every three cycles until progression. A total of 77 patients with a median age of 70 years were enrolled. Patients had received a median of three previous therapies and 32% had undergone previous transplant. The overall response rate (ORR) was 30% (95% confidence interval: 20-41%), with 20 patients achieving a partial remission and 3 a complete remission unconfirmed. The ORR in diffuse large B cell was 30% (14/47), 32% (6/19) in mantle cell and 38% (3/8) in follicular grade 3. The median duration of response was 5.7 months. Grade 3 or 4 anemia, neutropenia and thrombocytopenia occurred in 14, 18 and 38% of patients, respectively. Everolimus has single-agent activity in relapsed/refractory aggressive NHL and provides proof-of-concept that targeting the mTOR pathway is clinically relevant.

Resveratrol, an activator of SIRT1, upregulates sarcoplasmic calcium ATPase and improves cardiac function in diabetic cardiomyopathy

Reduced sarcoplasmic calcium ATPase (SERCA2a) expression has been shown to play a significant role in the cardiac dysfunction in diabetic cardiomyopathy. The mechanism of SERCA2a repression is, however, not known. This study was designed to examine the effect of resveratrol (RSV), a potent activator of SIRT1, on cardiac function and SERCA2a expression in chronic type 1 diabetes. Adult male mice were injected with streptozotocin (STZ) and fed with either a regular diet or a diet enriched with RSV. STZ administration produced progressive decline in cardiac function, associated with markedly reduced SERCA2a and SIRT1 protein levels and increased collagen deposition; RSV treatment to these mice had a tremendous beneficial effect both in terms of improving SERCA2a expression and on cardiac function. In cultured cardiomyocytes, RSV restored SERCA2 promoter activity, which was otherwise highly repressed in high-glucose media. Protective effects of RSV were found to be dependent on its ability to activate Silent information regulator (SIRT) 1. In cardiomyocytes, overexpression of SIRT1 was found sufficient to activate SERCA2 promoter in a dose-dependent manner. In contrast, pretreatment of cardiomyocytes with SIRT1 antagonist, splitomycin, blocked these beneficial effects of RSV. In addition, SIRT1 knockout (+/-) mice were also found to be more sensitive to STZ-induced decline in SERCA2a mRNA. The data demonstrate that, in chronic diabetes, 1) the enzymatic activity of cardiac SIRT1 is reduced, which contributes to reduced expression of SERCA2a and 2) through activation of SIRT1, RSV enhances expression of SERCA2a and improves cardiac function.

Model-Based Population Pharmacokinetic Analysis of Nivolumab in Patients With Solid Tumors

Nivolumab is a fully human monoclonal antibody that inhibits programmed death‐1 activation. The clinical pharmacology profile of nivolumab was analyzed by a population pharmacokinetics model that assessed covariate effects on nivolumab concentrations in 1,895 patients who received 0.3–10.0 mg/kg nivolumab in 11 clinical trials. Nivolumab pharmacokinetics is linear with a time‐varying clearance. A full covariate model was developed to assess covariate effects on pharmacokinetic parameters. Nivolumab clearance and volume of distribution increase with body weight. The final model included the effects of baseline performance status (PS), baseline body weight, and baseline estimated glomerular filtration rate (eGFR), sex, and race on clearance, and effects of baseline body weight and sex on volume of distribution in the central compartment. Sex, PS, baseline eGFR, age, race, baseline lactate dehydrogenase, mild hepatic impairment, tumor type, tumor burden, and programmed death ligand‐1 expression had a significant but not clinically relevant (<20%) effect on nivolumab clearance.

Molecular cloning and expression of the mouse ornithine decarboxylase gene

We used mRNA from a mutant S49 mouse lymphoma cell line that produces ornithine decarboxylase (OrnDCase) as its major protein product to synthesize and clone cDNA. Plasmids containing OrnDCase cDNA were identified by hybrid selection of OrnDCase mRNA and in vitro translation. The two of these with the largest inserts together span 2.05 kilobases of cDNA. Southern blot analysis of DNA from wild-type or mutant S49 cells, cleaved with EcoRI or with BamHI, revealed multiple bands homologous to OrnD-Case cDNA, only one of which was amplified in the mutant cells. RNA transfer blot analysis showed that the major OrnD-Case mRNA in the mouse lymphoma cells is 2.0 kilobases long. A similar size mRNA was found in mouse kidney and was more abundant in the kidneys of mice treated with testosterone, an inducer of OrnDCase activity in that tissue.

Effects of uracil incorporation, DNA mismatches, and abasic sites on cleavage and religation activities of mammalian topoisomerase I

Abasic sites and deamination of cytosine to uracil are probably the most common types of endogenous DNA damage. The effects of such lesions on DNA topoisomerase I (top1) activity were examined in oligonucleotides containing a unique top1 cleavage site. The presence of uracils and abasic sites within the first 4 bases immediately 5' to the cleavage site suppressed normal top1 cleavage and induced new top1 cleavage sites. Uracils immediately 3' to the cleavage site increased cleavage and produced a camptothecin mimicking effect. A mismatch with a bulge or abasic sites immediately 3' to the top1 cleavage site irreversibly trapped top1 cleavable complexes in the absence of camptothecin and produced a suicide cleavage complex. These results demonstrate that top1 activity is sensitive to physiological, environmental, and pharmacological DNA modifications and that top1 can act as a specific mismatch- and abasic site-nicking enzyme.

Aged mice are more sensitive to 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine treatment than young adults

Parkinson's disease is a neurodegenerative disorder characterized mainly by damage to the dopaminergic nigrostriatal system. Recently, the neurotoxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) has been shown to induce damage in the nigrostriatal system, accompanied by Parkinson-like symptoms in humans. We present here evidence that MPTP treatment in aged 21-month-old mice produced a marked reduction in the presence and intensity of fluorescence in noradrenergic neurons of the locus coeruleus and in dopaminergic neurons of the ventral tegmental area in addition to extensive damage to the substantia nigra. Aged mice treated with MPTP also showed physical signs of movement disability characterized by marked akinesia, rigidity of the hind limbs, and an initial resting tremor of the entire body. Such symptoms were less evident in young mice treated with MPTP. These remarkable initial behavioral effects of MPTP treatment in aged mice and evidence of reduced catecholamine fluorescence in the locus coeruleus and ventral tegmental area suggest that aged mice are more sensitive to, and more severely affected by MPTP treatment than young mice. We suggest that these MPTP-treated aged mice provide a useful animal model for studying both anatomical and functional characteristics of Parkinson's disease.

Monocyte-derived human macrophages and peripheral blood mononuclear cells infected with ebola virus secrete MIP-1alpha and TNF-alpha and inhibit poly-IC-induced IFN-alpha in vitro

Ebola virus infection of humans is associated with high levels of circulating inflammatory chemokines and cytokines. We demonstrate that direct infection of human PBMC results in the induction of MCP-1, MIP-1alpha, RANTES, and TNF-alpha as early as 24 h p.i. in response to live virus. Monocyte-derived macrophages infected with live Ebola-virus secreted MIP-1alpha and TNF-alpha specifically while RANTES and MCP-1 were secreted by with both live or inactivated virus stimulation and do not require viral replication. Type I interferons (IFN-alpha and -beta), IL-1beta and IL-10, were not induced by Ebola virus. Furthermore, live virus infection of both PBMCs and monocytes-derived macrophages inhibited IFN-alpha induced by double-stranded RNA in vitro. These data provide the first direct evidence of a role for macrophages in the pathogenesis to Ebola virus and suggest that Ebola virus can inhibit cellular antiviral mechanisms mediated by type I interferons.

Amplification of DNA markers from evolutionarily diverse genomes using single primers of simple-sequence repeats

The abundance and scattered distribution of simple-sequence repeats (SSR) in eukaryotic genomes prompted us to explore the use of SSR-based oligonucleotide primers in single primer amplification reactions. In a pilot experiment, 23 primers were used across a panel of evolutionarily diverse eukaryotic genomes, including grapes, lettuce, tomato, pine, maize, salmon, chicken, Holstein cows and humans. The primers were 16-20 bases in length and represented SSRs of di-, tri-, tetra-, and pentanucleotide repeats. The results showed that tetranucleotide repeat primers were most effective in amplifying polymorphic patterns. Of 11 such primers tested, 70% produced polymorphic patterns from the DNA of one or more species. Primers representing a combination of two tetranucleotide repeats, or compound microsatellites, were equally effective. The polymorphisms contained in such fingerprints were able to identify individuals of vertebrate species as well as lines or varieties of plants. Inheritance of the polymorphic bands was studied in a maize recombinant inbred population, DE811 x B73. Thirty-two polymorphic bands, derived from two amplification patterns, were mapped as dominant markers on an existing RFLP map of the same population. The bands were distributed across nine of the ten chromosomes.

Depth of invasion is the most significant histological predictor of subclinical cervical lymph node metastasis in early squamous carcinomas of the oral cavity

AIMS

Cervical node metastasis is the single most important prognostic factor in head and neck squamous carcinomas. Taking a homogenous patient population, applying stringent selection criteria, and standard pathological evaluation methods, this retrospective study aims to establish histological predictors of subclinical cervical node metastasis in early (T1-T2/N0) squamous carcinomas of the oral cavity, thereby identifying a subset of patients who are at an increased risk for cervical node metastasis.

METHODS

Forty-eight previously untreated patients with clinically T1 or T2, and N0, squamous carcinomas of the oral cavity who were treated with primary excision of the tumour and elective neck node dissection were selected. Various histological factors including T size, gross and microscopic tumour depth and thickness, grade of differentiation, pattern of invasion, inflammatory response, perineural and lymphovascular invasion were studied. The statistical significance of various parameters as predictors of subclinical node metastasis was determined using logistic regression analysis.

RESULTS

Of all the parameters studied, microscopic tumour depth and thickness were the only significant factors (P value=0.026 and 0.046, respectively) which correlated with cervical node metastasis, on univariate analysis. Tumour depth emerged as a single most significant predictor on multivariate analysis. Majority of patients with node metastasis had a tumour depth of more than or equal to 5 mm.

CONCLUSION

Depth is the most significant predictor of cervical node metastasis in early squamous carcinomas of the oral cavity. Patients with a tumour depth of more than or equal to 5 mm are at an increased risk of harbouring node metastasis, hence should be taken up for elective node dissection.

Pharmacologic rescue of lethal seizures in mice deficient in succinate semialdehyde dehydrogenase

Succinate semialdehyde dehydrogenase (ALDH5A1, encoding SSADH deficiency is a defect of 4-aminobutyric acid (GABA) degradation that manifests in humans as 4-hydroxybutyric (gamma-hydroxybutyric, GHB) aciduria. It is characterized by a non-specific neurological disorder including psychomotor retardation, language delay, seizures, hypotonia and ataxia. The current therapy, vigabatrin (VGB), is not uniformly successful. Here we report the development of Aldh5a1-deficient mice. At postnatal day 16-22 Aldh5a1-/- mice display ataxia and develop generalized seizures leading to rapid death. We observed increased amounts of GHB and total GABA in urine, brain and liver homogenates and detected significant gliosis in the hippocampus of Aldh5a1-/- mice. We found therapeutic intervention with phenobarbital or phenytoin ineffective, whereas intervention with vigabatrin or the GABAB receptor antagonist CGP 35348 (ref. 2) prevented tonic-clonic convulsions and significantly enhanced survival of the mutant mice. Because neurologic deterioration coincided with weaning, we hypothesized the presence of a protective compound in breast milk. Indeed, treatment of mutant mice with the amino acid taurine rescued Aldh5a1-/- mice. These findings provide insight into pathomechanisms and may have therapeutic relevance for the human SSADH deficiency disease and GHB overdose and toxicity.

Passive transfer of antibodies protects immunocompetent and imunodeficient mice against lethal Ebola virus infection without complete inhibition of viral replication

Ebola hemorrhagic fever is a severe, usually fatal illness caused by Ebola virus, a member of the filovirus family. The use of nonhomologous immune serum in animal studies and blood from survivors in two anecdotal reports of Ebola hemorrhagic fever in humans has shown promise, but the efficacy of these treatments has not been demonstrated definitively. We have evaluated the protective efficacy of polyclonal immune serum in a mouse model of Ebola virus infection. Our results demonstrate that mice infected subcutaneously with live Ebola virus survive infection and generate high levels of anti-Ebola virus immunoglobulin G (IgG). Passive transfer of immune serum from these mice before challenge protected upto 100% of naive mice against lethal Ebola virus infection. Protection correlated with the level of anti-Ebola virus IgG titers, and passive treatment with high-titer antiserum was associated with a delay in the peak of viral replication. Transfer of immune serum to SCID mice resulted in 100% survival after lethal challenge with Ebola virus, indicating that antibodies alone can protect from lethal disease. Thus antibodies suppress or delay viral growth, provide protection against lethal Ebola virus infection, and may not require participation of other immune components for protection.

Recommendations from the CSO-HNS taskforce on performance of tracheotomy during the COVID-19 pandemic

INTRODUCTION

The performance of tracheotomy is a common procedural request by critical care departments to the surgical services of general surgery, thoracic surgery and otolaryngology - head & neck surgery. A Canadian Society of Otolaryngology - Head & Neck Surgery (CSO-HNS) task force was convened with multi-specialty involvement from otolaryngology-head & neck surgery, general surgery, critical care and anesthesiology to develop a set of recommendations for the performance of tracheotomies during the COVID-19 pandemic.

MAIN BODY

The tracheotomy procedure is highly aerosol generating and directly exposes the entire surgical team to the viral aerosol plume and secretions, thereby increasing the risk of transmission to healthcare providers. As such, we believe extended endotracheal intubation should be the standard of care for the entire duration of ventilation in the vast majority of patients. Pre-operative COVID-19 testing is highly recommended for any non-emergent procedure.

CONCLUSION

The set of recommendations in this document highlight the importance of avoiding tracheotomy procedures in patients who are COVID-19 positive if at all possible. Recommendations for appropriate PPE and environment are made for COVID-19 positive, negative and unknown patients requiring consideration of tracheotomy. The safety of healthcare professionals who care for ill patients and who keep critical infrastructure operating is paramount.

Regulation of STAT3 by histone deacetylase-3 in diffuse large B-cell lymphoma: implications for therapy

Diffuse large B-cell lymphoma (DLBCL) with an activated B-cell (ABC) gene-expression profile has been shown to have a poorer prognosis compared with tumors with a germinal center B-cell type. ABC cell lines have constitutive activation of STAT3; however, the mechanisms regulating STAT3 signaling in lymphoma are unknown. In studies of class-I histone deacetylase (HDAC) expression, we found overexpression of HDAC3 in phospho STAT3-positive DLBCL and the HDAC3 was found to be complexed with STAT3. Inhibition of HDAC activity by panobinostat (LBH589) increased p300-mediated STAT3(Lys685) acetylation with increased nuclear export of STAT3 to the cytoplasm. HDAC inhibition abolished STAT3(Tyr705) phosphorylation with minimal effect on STAT3(Ser727) and JAK2 tyrosine activity. pSTAT3(Tyr705)-positive DLBCLs were more sensitive to HDAC inhibition with LBH589 compared with pSTAT3(Tyr705)-negative DLBCLs. This cytotoxicity was associated with downregulation of the direct STAT3 target Mcl-1. HDAC3 knockdown upregulated STAT3(Lys685) acetylation but prevented STAT3(Tyr705) phosphorylation and inhibited survival of pSTAT3-positive DLBCL cells. These studies provide the rationale for targeting STAT3-positive DLBCL tumors with HDAC inhibitors.

The role of pharmacokinetics and pharmacodynamics in phosphodiesterase-5 inhibitor therapy

Differences in clinical pharmacology of the currently marketed phosphodiesterase (PDE)5 inhibitors sildenafil, vardenafil and tadalafil are largely determined by their pharmacokinetic (PK) properties and their PDE5 inhibitory activity profile. This review outlines the basic concepts of pharmacokinetics and pharmacokinetic pharmacodynamic (PK/PD) relationships and their relevance to dose selection and applied pharmacotherapy. It is followed by a detailed comparative discussion on the pharmacokinetics and exposure-response relationship of the currently available PDE5 inhibitors, including known drug-drug interactions and dosage adjustments in special populations. The review is aimed at providing a critical assessment of the pharmacokinetics of PDE5 inhibitors, which may assist clinicians in tailoring drug and/or treatment regimens to the unique needs of each individual patient with erectile dysfunction.

Lack of reproducibility in pregnancy of Korotkoff phase IV as measured by mercury sphygmomanometry

BACKGROUND

Since hypertensive disorders of pregnancy are common, blood pressure is frequently measured in all pregnant women. Many authorities recommend that Korotkoff phase IV (K4, muffling of sound) is taken as the diastolic identification point measured on mercury sphygmomanometry in pregnancy because of reports that phase V (K5, disappearance of sound) is at or near to zero cuff pressure in some pregnant women. We compared the identification and reproducibility of K4 and K5 by observers unaware of each other's results.

METHODS

In the first part of the study, two pairs of observers each took 340 measurements in 85 pregnant women. The second part of the study consisted of 1120 measurements in 80 pregnant and 80 non-pregnant women by five pairs of observers. Measurements were taken simultaneously by sphygmomanometry with a shared cuff and diaphragm; the observers were in separate booths.

FINDINGS

K5 was identified in all measurements by both observers and never approached zero. K4 was heard in only 52% of measurements; in 33% of cases it was heard by only one of the pair of observers, so the pair agreed on its detection in only 19% of readings. Visual analogue scores used to assess Korotkoff sound quality indicated that systolic blood pressure was perceived significantly more clearly than diastolic blood pressure (K4 or K5). Even when K4 was heard by both observers, agreement on its value was poor (78% within 5 mm Hg vs 86% for K5, p < 0.05). K4 was heard significantly less often in non-pregnant women (32% of measurements). There was also no consistency in the identification of K4 within individual women.

INTERPRETATION

K4 has little value in clinical management because it cannot be reproduced accurately. We recommend that K4 should be replaced by K5 as the measure of diastolic blood pressure in pregnancy.

TSPAN5, ERICH3 and selective serotonin reuptake inhibitors in major depressive disorder: pharmacometabolomics-informed pharmacogenomics

Millions of patients suffer from major depressive disorder (MDD), but many do not respond to selective serotonin reuptake inhibitor (SSRI) therapy. We used a pharmacometabolomics-informed pharmacogenomics research strategy to identify genes associated with metabolites that were related to SSRI response. Specifically, 306 MDD patients were treated with citalopram or escitalopram and blood was drawn at baseline, 4 and 8 weeks for blood drug levels, genome-wide single nucleotide polymorphism (SNP) genotyping and metabolomic analyses. SSRI treatment decreased plasma serotonin concentrations (P<0.0001). Baseline and plasma serotonin concentration changes were associated with clinical outcomes (P<0.05). Therefore, baseline and serotonin concentration changes were used as phenotypes for genome-wide association studies (GWAS). GWAS for baseline plasma serotonin concentrations revealed a genome-wide significant (P=7.84E-09) SNP cluster on chromosome four 5' of TSPAN5 and a cluster across ERICH3 on chromosome one (P=9.28E-08) that were also observed during GWAS for change in serotonin at 4 (P=5.6E-08 and P=7.54E-07, respectively) and 8 weeks (P=1.25E-06 and P=3.99E-07, respectively). The SNPs on chromosome four were expression quantitative trait loci for TSPAN5. Knockdown (KD) and overexpression (OE) of TSPAN5 in a neuroblastoma cell line significantly altered the expression of serotonin pathway genes (TPH1, TPH2, DDC and MAOA). Chromosome one SNPs included two ERICH3 nonsynonymous SNPs that resulted in accelerated proteasome-mediated degradation. In addition, ERICH3 and TSPAN5 KD and OE altered media serotonin concentrations. Application of a pharmacometabolomics-informed pharmacogenomic research strategy, followed by functional validation, indicated that TSPAN5 and ERICH3 are associated with plasma serotonin concentrations and may have a role in SSRI treatment outcomes.

Synthesis, crystal structure, spectral studies, and catechol oxidase activity of trigonal bipyramidal Cu(II) complexes derived from a tetradentate diamide bisbenzimidazole ligand

A new benzimidazole-based diamide ligand-N,N'-bis(glycine-2- benzimidazolyl)hexanediamide (GBHA)-has been synthesized and utilized to prepare Cu(II) complexes of general composition [Cu(GBHA)X]X, where X is an exogenous anionic ligand (X = Cl(-), NO(3)(-), SCN(-)). The X-ray structure of one of the complexes, [Cu(GBHA)Cl]Cl.H(2)O.CH(3)OH, has been obtained. The compound crystallizes in the monoclinic space group C2/c with unit cell dimensions a = 26.464(3) A, b = 10.2210(8) A, c = 20.444(2) A, alpha = 90 degrees, beta = 106.554(7) degrees, gamma = 90 degrees, V= 5300.7(9) A(3), and Z = 8. To the best of our knowledge, the [Cu(GBHA)Cl]Cl.H(2)O.CH(3)OH complex is the first structurally characterized mononuclear trigonal bipyramidal copper(II) bisbenzimidazole diamide complex having coordinated amide carbonyl oxygen. The coordination geometry around the Cu(II) ion is distorted trigonal bipyramidal (tau = 0.59). Two carbonyl oxygen atoms and a chlorine atom form the equatorial plane, while the two benzimidazole imine nitrogen atoms occupy the axial positions. The geometry of the Cu(II) center in the solid state is not preserved in DMSO solution, changing to square pyramidal, as suggested by the low-temperature EPR data g( parallel) > g( perpendicular) > 2.0023. All the complexes display a quasi-reversible redox wave due to the Cu(II)/Cu(I) reduction process. E(1/2) values shift anodically from Cl(-) < NO(3)(-) < SCN(-), indicating that the bound Cl(-) ion stabilizes the Cu(II) ion while the N-bonded SCN(-) ion destabilizes the Cu(II) state in the complex. When calculated against NHE, the redox potentials turn out to be quite positive as compared to other copper(II) benzimidazole bound complexes (Nakao, Y.; Onoda, M.; Sakurai, T.; Nakahara, A.; Kinoshita, L.; Ooi, S. Inorg. Chim. Acta 1988, 151, 55. Addison, A. W.; Hendricks, H. M. J.; Reedijk, J.; Thompson, L. K. Inorg. Chem. 1981, 20 (1), 103. Sivagnanam, U.; Palaniandavar, M. J. Chem. Soc., Dalton Trans. 1994, 2277. Palaniandavar, M.; Pandiyan, T.; Laxminarayan, M.; Manohar, H. J. Chem. Soc., Dalton Trans. 1995, 457. Sakurai, T.; Oi, H.; Nakahara, A. Inorg. Chim. Acta 1984, 92, 131). It is therefore concluded that binding of amide carbonyl oxygen destabilizes the Cu(II) state. The complex [Cu(II)(GBHA)(NO(3))](NO(3)) could be successfully reduced by the addition of dihydroxybenzenes to the corresponding [Cu(I)(GBHA)](NO(3)). (1)H NMR of the reduced complex shows slightly broadened and shifted (1)H signals. The reduction of the Cu(II) complex presumably occurs with the corresponding 2e(-) oxidation of the quinol to quinone. Such a conversion is reminiscent of the functioning of a copper-containing catechol oxidase from sweet potatoes and the met form of the enzyme tyrosinase.

New Lignan Glucosides from Stemmadenia minima*

Reinvestigation of the polar fractions from the stem bark of STEMMADENIA MINIMA A. Gentry (Apocynaceae) afforded two known and four new lignan glucosides. Their structures were deduced by spectroscopic and chemical methods.

Role of magnetic resonance (MR) in the diagnosis and management of intracranial tuberculomas

Thirty-one patients with intracranial tuberculomas were diagnosed on the basis of magnetic resonance (MR) imaging. The diagnosis was confirmed in 30; one case was a false-positive. A total of 44 tuberculomas was found in these patients of which 41 were distributed in the cerebral hemispheres, two in the brainstem and one in the cerebellum. No correlation was found between the type of lesion seen on CT and those seen on MR imaging. CT was negative in one patient with a low brainstem tuberculoma. The final diagnosis was based on the response to antituberculous drug treatment as judged by serial MR imaging in 29 patients and by biopsy in one; and one was false-positive. Thirty-nine tuberculomas, all under 2.5 cm in size, showed complete resolution after 5-8 months of treatment. The remaining five lesions were larger than 2.5 cm; four showed a 50% reduction in size after 12 months of treatment and one was completely excised. Three types of response are described to the treatment with anti-tuberculous drugs. The diagnosis of intracranial tuberculomas can be made more objectively with MR imaging.