Ab initio studies of the reaction of hydrogen transfer from DNA to the calicheamicinone diradical

BACKGROUND

The biological activity of enediyne chemotherapeutic (anti-cancer) agents is attributed to their ability to cleave duplex DNA. Part of the reaction of cleavage is the abstraction of hydrogens from the deoxyribose moiety of DNA by the biradical formed via a Bergman rearrangement.

METHODS

The mechanism of the reaction of abstraction of two hydrogen atoms from two deoxyribophosphate molecules by the calicheamicinone biradical is studied with ab initio calculations at Hartree-Fock and post-Hartree-Fock level. The Titan program is used to perform the calculations.

RESULTS

It is found that the reactions are exothermic and thus thermodynamically reasonable.

CONCLUSIONS

The mechanism of DNA cleavage by the enediyne-containing drugs is likely to proceed by the abstraction of the hydrogens from deoxyribose by the biradical formed by the drug. Further studies should determine in which way the modification of the drug's structure would make this reaction even more exothermic and, thus, more likely to occur.

Radon exhalation and radiometric prospecting on rocks associated with Cu-U mineralizations in the Singhbhum shear zone, Bihar

The Singhbhum thrust belt is a 200 km long arcuate orogenic belt in Bihar, eastern India. The huge mineral resources, viz. copper, uranium, magnetite, apatite and molybdenite, etc., make it significant from an economic as well as a geological point of view. The belt hosts three types of mineralization: sulphides of copper and other metals, uranium oxides and apatite-magnetite. Several distinct geological episodes are responsible for the evolution of mineralization and the thrust zone itself. Extensive and reliable radiometric prospecting and assaying have been carried out by us for the past 5 years from Dhobani in the east to Turamdih in the west of the Singhbhum shear zone. The present work indicates uranium mineralization in the Pathargora-Rakha area presently being mined for copper and also within areas in the vicinity of Bhatin. Studies on radon emanation have also been undertaken in some parts of the shear zone which indicate reasonably high radon emanation of the soils and rocks studied. This suggests the need for regular monitoring and suitable controls on the mine environment (air quality) and its vicinity. Radon emanation studies coupled with gamma-ray spectrometry and the subsequent modelling of the radiometric and radon measurements will help in the application of radon as a geophysical tracer in exploration of radioactive ore bodies and in radon risk assessment as well as in delineating active and passive faults and even in petroleum exploration.

IEX-1, an immediate early gene, increases the rate of apoptosis in keratinocytes

IEX-1, an immediate early gene, is widely expressed in epithelial and endothelial tissues, and is altered by a variety of growth regulatory factors. We have shown that expression of IEX-1 in keratinocytes increases the growth rate of these cells. The effects of IEX-1 on apoptosis, however, are unclear. To clarify the effects of IEX-1 on apoptosis, we investigated the effects of IEX-1 expression in keratinocytes (HaCaT cells) in the basal state and after the induction of cellular stress. Under normal, non-stressed conditions, both control (HaCaT) and IEX-1-transfected (IEX-HaCaT) cell lines showed no significant differences in the activity of a key apoptotic enzyme, caspase 3 despite significantly higher levels of IEX-1 expression. IEX-HaCaT cells grew faster than HaCaT cells. When both cell lines were irradiated with ultraviolet B radiation, caspase 3 activity increased to a greater extent in the IEX-HaCaT cells than in HaCaT cells. Camptothecin increased caspase 3 activity twice as much in the IEX-HaCaT cells when compared to HaCaT cells. When histone-complex DNA fragments were measured in IEX-HaCaT or HaCaT cells following UVB irradiation or treatment with camptothecin, significantly higher amounts of nucleosomes were seen in the IEX-HaCaT transfected cells. Likewise, serum deprivation induced higher degrees of apoptosis in IEX-HaCaT cells than in HaCaT cells. We conclude that overexpression of IEX-1 in HaCaT keratinocytes increases the growth rate of cells under basal conditions; in the basal state the rate of apoptosis is unchanged. However, the rate of apoptosis increases in IEX-1 overexpressing HaCaT keratinocytes after cells are subjected to stress.

Synthesis and antiviral activity of novel acyclic nucleoside analogues of 5-(1-azido-2-haloethyl)uracils

We present the discovery of a novel category of 5-substituted acyclic pyrimidine nucleosides as potent antiviral agents. A series of 1-[(2-hydroxyethoxy)methyl] (5-7), 1-[(2-hydroxy-1-(hydroxymethyl)ethoxy)methyl] (8-10), and 1-[4-hydroxy-3-(hydroxymethyl)-1-butyl] (11-13) derivatives of 5-(1-azido-2-haloethyl)uracil were synthesized and evaluated for their biological activity in cell culture. 1-[4-Hydroxy-3-(hydroxymethyl)-1-butyl]-5-(1-azido-2-chloroethyl)uracil (12) was the most effective antiviral agent in the in vitro assays against DHBV (EC(50) = 0.31-1.55 microM) and HCMV (EC(50) = 3.1 microM). None of the compounds investigated showed any detectable toxicity to several stationary and proliferating host cells.

A single nucleotide polymorphism in the 3'untranslated region of the CDKN2A gene is common in sporadic primary melanomas but mutations in the CDKN2B, CDKN2C, CDK4 and p53 genes are rare

In this report we present the results of mutational analysis of the CDKN2B, CDKN2C, CDK4, p53 genes and 5'UTR of the CDKN2A gene in a set of 44 sporadic primary melanomas, which had been earlier analysed for mutations in the CDKN2A (p16/p14(ARF)) gene. No tumour-associated mutations were detected except in 1 melanoma where we found a CC>T* deletion-mutation in the codon 151-152 (exon 5) of the p53 gene. On the basis of our preliminary results, we did extended genotyping of the 500 C>G and 540 C>T polymorphisms in the 3'UTR of the CDKN2A gene in 229 melanoma cases and 235 controls. The T-allele frequency (for 540 C>T polymorphism) in melanomas was significantly higher than in controls (0.14 vs. 0.08; chi(2) = 5.95, p = 0.01; OR = 1.71, 95%CI = 1.11-2.66). The heterozygote frequency for this polymorphism was 0.26 (59/229) in melanomas compared to 0.13 (30/235) in healthy controls (chi(2) = 11.4; p = 0.0007; OR = 2.34, 95% CI = 1.40-3.92). The frequency of the 500 C>G polymorphism in the 3'UTR in the CDKN2A gene was not significantly higher in melanomas compared to healthy controls. The 500 C>G polymorphism, however, was in linkage disequilibrium with approximately 50 kb apart the C>A intronic polymorphism in the CDKN2B gene (determined in 44 melanomas and 90 controls; Fisher exact test, p<0.0001). Finally, the sequence analysis of genomic DNA isolated from T cell lymphocytes of healthy individuals exhibited that the codon reported as last of exon 2 of the CDKN2C gene is rather the first codon of exon 3.

Novel 5-vinyl pyrimidine nucleosides with potent anti-hepatitis B virus activity

Synthesis and antiviral activities of novel N-1 alkyl substituted pyrimidines, 1-[(2-hydroxyethoxy)methyl]-5-vinyluracil (5), 1-[(2-hydroxy-1-(hydroxymethyl)ethoxy)methyl]-5-vinyluracil (6), and 1-[4-hydroxy-3-(hydroxymethyl)-1-butyl]-5-vinyluracil (7) are reported. Compounds 6 and 7 were potent inhibitors of DHBV in cell culture, in contrast, all of the compounds described were devoid of activity against TK(+) HSV-1 and TK(-) HSV-1.

The ORF3 protein of hepatitis E virus binds to Src homology 3 domains and activates MAPK

The hepatitis E virus (HEV) is the causative agent of hepatitis E, an acute form of viral hepatitis. The biology and pathogenesis of HEV remain poorly understood. We have used in vitro binding assays to show that the HEV ORF3 protein (pORF3) binds to a number of cellular signal transduction pathway proteins. This includes the protein tyrosine kinases Src, Hck, and Fyn, the p85alpha regulatory subunit of phosphatidylinositol 3-kinase, phospholipase Cgamma, and the adaptor protein Grb2. A yeast two-hybrid assay was used to further confirm the pORF3-Grb2 interaction. The binding involves a proline-rich region in pORF3 and the src homology 3 (SH3) domains in the cellular proteins. Competition assays and computer-assisted modeling was used to evaluate the binding surfaces and interaction energies of the pORF3.SH3 complex. In pORF3-expressing cells, pp60(src) was found to associate with an 80-kDa protein, but no activation of the Src kinase was observed in these cells. However, there was increased activity and nuclear localization of ERK in the pORF3-expressing cells. These studies suggest that pORF3 is a viral regulatory protein involved in the modulation of cell signaling. The ORF3 protein of HEV appears to be the first example of a SH3 domain-binding protein encoded by a virus that causes an acute and primarily self-limited infection.

Pancytopenia--a six year study

All cases of pancytopenia seen over a six year period in two hematology centres were analysed. Patients receiving myelotoxic chemotherapy or those with leukemic cells in peripheral smear were excluded. There were a total of 166 cases. The four major causes were: aplastic anaemia in 49, megaloblastic anaemia in 37, aleukemic leukemia or lymphoma in 30 and hypersplenism in 19 cases. Bone marrow aspiration was often unsuccessful in obtaining an adequate sample, while biopsy was usually diagnostic. Both bone marrow aspiration and biopsy should be performed simultaneously in pancytopenic patients when the diagnosis is elusive. Megaloblastic anaemia is a major cause of pancytopenia, and may present acutely in the critically ill. It is a rapidly correctable disorder and should not be missed.

Angiotensin converting enzyme insertion allele in relation to high altitude adaptation

Angiotensin converting enzyme (ACE) gene I/D polymorphism has been associated with high altitude (HA) disorders as well as physical performance. We, however, envisage that the polymorphism may be associated with adaptation to the hypobaric hypoxia of altitude, thus facilitating physical performance. For this purpose, three unrelated adult male groups, namely (1) the Ladakhis (HLs), who reside at and above a height of 3600 m, (2) lowlanders, who migrated to Ladakh (MLLs), and (3) resident lowlanders (LLs), have been investigated. The HLs had significantly (p & 0.001) greater numbers of the II homozygotes and the ID heterozygotes than the DD homozygotes, the genotype distribution being 0.46, 0.43 and 0.11 for II, ID and DD genotypes respectively. The MLLs comprised 60% II homozygotes, which was higher (p & 0.001) than the HLs (46%). In the LLs, the heterozygotes were greater (p & 0.001) in number than the II and DD homozygotes. The I allele frequency was 0.72 in the MLLs, 0.67 in the HLs and 0.55 in the LLs. Polymorphism study suggested that the II genotype could be associated with altitude adaptation, which might influence physical efficiency.

The selective serotonin reuptake inhibitor paroxetine is effective in more generalized and in less generalized social anxiety disorder

RATIONALE

The DSM-IV includes the specifier "generalized" to refer to social anxiety disorder (social phobia) patients if the fears include "most social situations". The focus on interventions such as the selective serotonin reuptake inhibitors (SSRIs) for generalized social anxiety disorder arguably runs the risk that inadequate treatment will be provided to patients with the non-generalized or discrete subtypes. There are, however, few data to address whether more generalized and less generalized subgroups of social anxiety disorder differ in response to medication.

OBJECTIVE

To compare response of more generalized and less generalized social anxiety disorder to pharmacotherapy.

METHODS

Data from three randomized placebo-controlled double-blind multicenter trials of the SSRI paroxetine in social anxiety disorder were pooled. Response on the Clinical Global Impression Global Improvement item was analyzed using logistic regression, and change in total Liebowitz Social Anxiety Score was analyzed using analysis of variance, with both models incorporating treatment (paroxetine vs placebo), subgroup (more generalized vs less generalized), demographic, and clinical variables.

RESULTS

The prevalence of more generalized social anxiety disorder was higher in females than in males. However, there was no significant difference in terms of age or clinical characteristics (duration of condition, baseline pulse, mean arterial blood pressure). At treatment endpoint there were significant treatment effects (for paroxetine vs placebo), but no significant subgroup effects (for more generalized vs less generalized).

CONCLUSIONS

Although the current database is limited insofar as few patients with discrete social anxiety disorder would have been included, it is helpful in addressing the value of medication for patients lying on the spectrum from generalized to non-generalized and discrete social anxiety disorder. Paroxetine was effective in both more generalized and in less generalized social anxiety disorder.

Enzyme-linked immunosorbent assay for recombinant K39 antigen in diagnosis and prognosis of Indian visceral leishmaniasis

The recombinant product (rK39) of the 39-amino-acid repeats encoded by a kinesin-like protein-encoding gene of Leishmania chagasi was evaluated by enzyme-linked immunosorbent assay (ELISA) for diagnostic potential and the ability to predict the response to therapy in Indian kala-azar or visceral leishmaniasis (VL); we also compared its performance with that of crude soluble antigen (CSA). At the diagnosis of VL, the anti-rK39 antibody titer was 59-fold higher than the anti-CSA antibody titer. With successful therapy, antibody titers declined steeply at the end of treatment and during follow-up. In contrast, patients who relapsed showed increased titers of antibodies to rK39. The extremely high levels of anti-rK39 antibodies in VL cases suggest the application of rK39 for sensitive and specific serodiagnosis, and rK39 ELISA is also valuable in monitoring drug therapy and detecting relapse of the disease.

Kinetics of human immunodeficiency virus type 1 (HIV) DNA integration in acutely infected cells as determined using a novel assay for detection of integrated HIV DNA

We have developed a novel linker-primer PCR assay for the detection and quantification of integrated human immunodeficiency virus type 1 (HIV) DNA. This assay reproducibly allowed the detection of 10 copies of integrated HIV DNA, in a background of 2 x 10(5) cell equivalents of human chromosomal DNA, without amplifying extrachromosomal HIV DNA. We have used this assay and a near-synchronous one-step T-cell infection model to investigate the kinetics of viral DNA accumulation following HIV infection. We report here that integrated HIV DNA started accumulating 1 h after the first appearance of extrachromosomal viral DNA and accounted for approximately 10% of the total HIV DNA synthesized in the first round of viral replication. These results highlight the efficient nature of integrase-mediated HIV integration in infected T cells.

Polymorphic insertion of additional repeat within an area of direct 8 bp tandem repeats in the 5'-untranslated region of the p53R2 gene and cancer risk

p53R2 is a recently cloned gene that functions in p53-induced DNA repair. In the 5'-untranslated region of the p53R2 gene two direct tandem 8 bp repeats are located. Within the region of these 8 bp direct repeats we have detected the insertion of an additional repeat. In order to determine a possible association of this novel polymorphism with any cancer or population, we carried out genotyping of 843 European and Asian controls and patients with various cancer types. In addition, 26 cancer cell lines were included in the study. No significant difference in polymorphic frequency could be demonstrated for any of the cancer types, although the allelic frequency in melanoma patients was lower than in controls (chi(2) = 3.28; P = 0.07; OR = 0.32; 95% CI 0.07-1.26). A significantly higher frequency of the polymorphism was detected in the compiled Caucasian individuals compared with Asians (chi(2) = 9.19; P = 0.002; OR = 3.13; 95% CI 1.39-7.43). In one tumour cell line we observed two extra inserted copies of the 8 bp repeat. The functional effect of the insertion polymorphism on the p53R2 gene transcription remains to be determined.

Ethnic variation in genotype frequencies of a p53 intron 7 polymorphism

Using a PCR-restriction enzyme-based method we found large ethnic variations when a C-->T polymorphism in the human p53 gene at position 14181 in intron 7 was studied in Finnish, Polish, Hungarian, Italian, Japanese, Indian and Chinese populations. The largest variations were found between Caucasian and Asian, genotype frequencies varied from C 0.95 and T 0.05 in the Finnish population to C 0.67 and T 0.33 in the Chinese population, the relative risk (RR) for T being 6.5 (95% CI 3.4-12.3, P < 0.001). Variations were also found between Finnish and Italian and between Italian and Chinese (RR for T 2.4, 95% CI 1.2-4.9 and 2.7, 95% CI 1.7-4.2, respectively).

Portal system thrombosis: a complication of long-term residence at extreme altitude

BACKGROUND

With induction of the Indian Army to heights over 5,000 meters above sea level, complications of long-term stay at extreme altitude have come to light. We describe our experience with patients developing portal system thrombosis.

METHODS

Clinical data were collected over 2 years on patients hospitalized for thrombotic complications from high-altitude (HAA) and non-high altitude (non-HAA) areas. Site of thrombosis was confirmed by imaging or at surgery. Patients were investigated for conditions that predispose to venous thrombosis.

RESULTS

Ten cases of portal system thrombosis were seen during the period; of these, 9 (mean age 28 [SD 3.9] years; all men) were from HAA. Mean duration of residence in HAA was 12.4 (4.9) months; two were smokers and six drank 7-22 g alcohol/day at least 5 times a week. The first symptom was abdominal pain; this was later complicated by gastrointestinal bleeding (n=5), fever (7), vomiting (7), and weight loss (5). Average time between onset of first symptom and reaching a tertiary-care hospital was 9.5 (4.7) days. Clinical examination showed ascites (8 cases), splenomegaly (7), and hepatomegaly (6). Mean hemoglobin level at admission was 15.8 (3.4) g/dL. Ascites was hemorrhagic; five cases also had large splenic hematoma. The site of thrombosis was splenic vein (7 cases), portal vein (6), and superior (4) and inferior (1) mesenteric vein. None of 5 patients investigated had any prothrombotic condition. Endoscopic/ sonographic evidence of development of collaterals appeared as early as 12-20 days after onset of symptoms.

CONCLUSION

Residence in HAA for extended periods is a risk factor for development of portal system thrombosis. Persistent pain in abdomen in such individuals should raise the possibility of portal system thrombosis.

Synthesis and biological investigations of 5-substituted pyrimidine nucleosides coupled to a dihydropyridine/pyridinium salt redox chemical delivery system

The syntheses, antiviral activities, and partition coefficients (P) of 3'-O-(1-methyl-1,4-dihydropyridyl-3-carbonyl)-coupled nucleosides are described. These novel compounds were designed in an effort to enhance the lipophilicity, and thereby the delivery to the CNS, without compromising the anti-HSV-1 activity of the parental nucleosides. We have previously reported the synthesis of 3'-O-(1-methyl-1,4-dihydropyridyl-3- carbonyl) analogs of 5-iodo-(5), 5-vinyl-(6), and (E)-5-(2-iodovinyl)-2'-deoxyuridines (7). We now report the synthesis of 5-iodo-3'-O-(1-methyl-1,4-dihydropyridyl-3- carbonyl)-5'-O-acetyl-2'-deoxyuridine (15) and 3'-O-(1-methyl-1,4-dihydropyridyl-3-carbonyl)-2'-deoxyuridine (17). Quarternization of the 3'-O-(3-pyridylcarbonyl) compounds (10,12) using iodomethane afforded the corresponding 1-methyl pyridinium salts (13,14) which were reduced with sodium dithionite to yield the corresponding 3'-O-1-methyl-1,4-dihydropyridyl-3-carbonyl compounds (15,16). The deprotection of 3'-O-(1-methyl-1,4-dihydropyridyl- 3-carbonyl)-5'-O-t-butyldimethylsilyl-2'-deoxyuridine (16) with Bu4N+F- afforded 3'-O-(1-methyl-1,4-dihydropyridyl-3-carbonyl)-2'-deoxyuridine (17). Compounds 5-7 and 15 were evaluated for their antiviral activity in vitro against HSV-1, HSV-2, HCMV, and VZV, and were found to retain anti-HSV-1, HSV-2 and VZV activity as compared to their parental nucleosides (1-3). In addition, the cellular toxicity of 3'-O-(1-methyl-1,4-dihydropyridyl-3-carbonyl)-coupled compounds (5-7 and 15) was found to be lower than the parent nucleosides. The lipophilicity of compounds (5-7,15,17) are enhanced substantially, compared to the parent nucleosides, as indicated by an increase in corresponding P values (1-octanol-water) upon replacement of the C-3' hydroxyl by 1-methyl-1,4-dihydropyridyl-3-carbonyl moiety.

Identification and characterization of a family of Rab11-interacting proteins

Rab11a is a small GTP-binding protein enriched in the pericentriolar plasma membrane recycling systems. We hypothesized that Rab11a-binding proteins exist as downstream effectors of its action. Here we define a family of four Rab11-interacting proteins: Rab11-Family Interacting Protein 1 (Rab11-FIP1), Rab11-Family Interacting Protein 2 (Rab11-FIP2), Rab11-Family Interacting Protein 3 (Rab11-FIP3), and pp75/Rip11. All four interacting proteins associated with wild type Rab11a and dominant active Rab11a (Rab11aS20V) as well as Rab11b and Rab25. Rab11-FIP2 also interacted with dominant negative Rab11a (Rab11aS25N) and the tail of myosin Vb. The binding of Rab11-FIP1, Rab11-FIP2, and Rab11-FIP3 to Rab11a was dependent upon a conserved carboxyl-terminal amphipathic alpha-helix. Rab11-FIP1, Rab11-FIP2, and pp75/Rip11 colocalized with Rab11a in plasma membrane recycling systems in both non-polarized HeLa cells and polarized Madin-Darby canine kidney cells. GFP-Rab11-FIP3 also colocalized with Rab11a in HeLa cells. Rab11-FIP1, Rab11-FIP2, and pp75/Rip11 also coenriched with Rab11a and H(+)K(+)-ATPase on parietal cell tubulovesicles, and Rab11-FIP1 and Rab11-FIP2 translocated with Rab11a and the H(+)K(+)-ATPase upon stimulating parietal cells with histamine. The results suggest that the function of Rab11a in plasma membrane recycling systems is dependent upon a compendium of protein effectors.

Dynamic chromatin remodeling on the HER2 promoter in human breast cancer cells

Deregulation of the HER2 oncogene occurs in 30% of human breast cancers and correlates with poor prognosis and increased propensity for metastasis. Since the molecular basis of HER2 overexpression in human cancers is not known, we sought to determine whether chromatin remodeling pathways are involved in the regulation of HER2 expression. We report that compared with breast cancer cells expressing a low level of HER2, HER2-overexpressing breast cancer cells contained significantly higher levels of acetylated and phosphorylated histone H3, and acetylated histone H4 associated with the HER2 promoter. Decreased recruitment of histone deacetylases in the promoter is also noted in the HER2-overexpressing cell. The association of acetylated histone H4 with HER2 gene chromatin and HER2 expression in breast cancer cells was upregulated by an inhibitor of histone deacetylases. Treatment with histone deacetylase inhibitor also reduced the association of histone deacetylase-1 and -2 with the HER2 promoter. In addition, the tumor promoters 12-O-tetradecanoylphorbol-13-acetate and okadaic acid stimulated the association of phosphorylated histone H3 on serine 10 with the HER2 promoter and also stimulated HER2 expression. These findings identify histone acetylation and histone phosphorylation as novel regulatory modifications that target HER2 gene chromatin, and suggest that elevated levels of these chromatin-relaxing components in the vicinity of the HER2 gene promoter may constitute an important non-genomic mechanism of HER2 overexpression in human breast cancer.

Molecular cloning and characterization of PELP1, a novel human coregulator of estrogen receptor alpha

Nuclear hormone receptors (NRs) are transcription factors whose activity is regulated by ligands and by coactivators or corepressors. We report the characterization of a new NR coregulator: proline-, glutamic acid-, leucine-rich protein 1 (PELP1), a novel human protein that comprises 1,282 amino acids and is localized on chromosome 17. The primary structure of PELP1 consists of several motifs present in most transcriptional regulators including nine NR-interacting boxes (LXXLL motifs), a zinc finger, and glutamic acid- and proline-rich regions. We demonstrate that PELP1 is a coactivator of estrogen receptor alpha (ERalpha). PELP1 enhances 17beta-estradiol-dependent transcriptional activation from the estrogen response element in a dose-dependent manner. PELP1 interacts with ERalpha and also with general transcriptional coactivators p300 and cAMP response element-binding protein-binding protein. PELP1 was differentially expressed in various human and murine tissues with the highest expression levels in the testes, mammary glands, and brain. We also provide evidence supporting the developmental regulation of PELP1 expression in murine mammary glands, the detectable expression of PELP1 in human mammary cancer cell lines, and the enhanced expression of PELP1 in human breast tumors. These findings suggest that PELP1 is a novel coregulator of ERalpha and may have a role in breast cancer tumorigenesis.

Synthesis and antiviral activity of novel 5-(1-cyanamido-2-haloethyl) and 5-(1-hydroxy(or methoxy)-2-azidoethyl) analogues of uracil nucleosides

A new class of 5-(1-cyanamido-2-haloethyl)-2'-deoxyuridines (4-6) and arabinouridines (7, 8) were synthesized by the regiospecific addition of halogenocyanamides (X-NHCN) to the 5-vinyl substituent of the respective 5-vinyl-2'-deoxyuridine (2) and 2'-arabinouridine (3). Reaction of 2 with sodium azide, ceric ammonium nitrate, and acetonitrile-methanol or water afforded the 5-(1-hydroxy-2-azidoethyl)-(10) and 5-(1-methoxy-2-azidoethyl)-2'-deoxyuridines (11). In vitro antiviral activities against HSV-1-TK(+) (KOS and E-377), HSV-1-TK(-), HSV-2, VZV, HCMV, and DHBV were determined. Of the newly synthesized compounds, 5-(1-cyanamido-2-iodoethyl)-2'-deoxyuridine (6) exhibited the most potent anti-HSV-1 activity, which was equipotent to acyclovir and superior to 5-ethyl-2'-deoxyuridine (EDU). In addition, it was significantly inhibitory for thymidine kinase deficient strain of HSV-1 (EC(50) = 2.3-15.3 microM). The 5-(1-cyanamido-2-haloethyl)-2'-deoxyuridines (4-6) all were approximately equipotent against HSV-2 and were approximately 1.5- and 15-fold less inhibitory for HSV-2 than EDU and acyclovir, respectively. Compounds 4-6 were all inactive against HCMV but exhibited appreciable antiviral activity against VZV. Their anti-VZV activity was similar or higher to that of EDU and approximately 5-12-fold lower than that of acyclovir. The 5-(1-cyanamido-2-haloethyl)-(7,8) analogues of arabinouridine were moderately inhibitory for VZV and HSV-1 (strain KOS), whereas compounds 10 and 11 were inactive against herpes viruses. Compounds 5 and 6 also demonstrated modest anti-hepatitis B virus activity against DHBV (EC(50) = 19.9-23.6 microM). Interestingly, the related 5-(1-azido-2-bromoethyl)-2'-deoxyuridine (1n) analogue proved to be markedly inhibitory to DHBV replication (EC(50) = 2.6-6.6 microM). All compounds investigated exhibited low host cell toxicity to several stationary and proliferating host cell lines as well as mitogen-stimulated proliferating human T lymphocytes.

Self- enucleation of eyes in schizophrenia- an unusual mode of deliberate self harm

Self inflicted injury to the eyes including self-enucleation is a rare phenomenon. The authors describe a case of bilateral self-enucleation in a patient with paranoid schizophrenia. A review of literature shows that self-enucleation is correlated with moral, religious and psychodynamic paradigms and various unconscious mechanisms have been proposed to explain this unusual behaviour.

Patients in treatment centres: are they all dependents?

The congruence between self reported drug use and urinalysis data among 89 consecutive opioid dependents at their first contact in an outpatient clinic was examined. For this purpose self reports of drug use within preceding 72 hr, laboratory analysis of urine samples by thin layer chromatography (TLC) were carried out for various drugs. The same samples were also confirmed by gas liquid chromatography (GLC). Many subjects reported concomitant poly-drug use. The base rate was found to be low for other drugs besides heroin. The conclusion could be dra wn more con vincingly as regard heroin use. Inaccuracy in self-report of drug use has been observed using GLC as a gold standard. The subjects are likely to be more accurate when they report abstinence than when reporting drug use. These results also suggest that clinicians should be cautious while prescribing agonist/partial agonists especially based on only self-report for long term maintenance program, as many patients may not be really physiolologically dependent.