Three new peroxides from the sponge Plakinastrella species

Two new five-membered-ring peroxide acids, plakinic acid F (3) and epiplakinic acid F (4), and a new peroxide-lactone, plakortolide F (5), were isolated from a sponge of the genus Plakinastrella collected from Felicite Island, Seychelles. The structures were elucidated through spectral analysis. The free acids 3 and 4 exhibit moderate antifungal activity against Candida albicans with minimum inhibitory concentrations of 25 micrograms/mL (SDB) and 3.1 micrograms/mL (RPMI) for 3, and 25 micrograms/mL (SDB) and 6.25 micrograms/mL (RPMI) for 4, respectively. Both also showed moderate in vitro inhibition of Aspergillus fumigatus with IC90's of 25 micrograms/mL.

The putative role of extra-synaptic mesolimbic dopamine in the neurobiology of nicotine dependence

A majority of habitual tobacco smokers find it very difficult to quit the habit because they become addicted to the nicotine present in tobacco smoke. Nicotine, like other psychostimulant drugs of abuse, increases dopamine release in the principal terminal field of the mesolimbic system, the nucleus accumbens, and there is evidence that this mediates the 'rewarding' properties of the drug, which reinforce its self-administration. This review focuses on the working hypothesis that addiction to nicotine, and other psychostimulant drugs, depends upon their ability to evoke a sustained increase in dopamine release directly into the extracellular space which lies between the cells in the nucleus accumbens where it stimulates extra-synaptic dopamine receptors. It is suggested that increased stimulation of these receptors is associated with increased incentive learning or the attribution of increased incentive salience to the cues associated with acquisition and delivery of the drug. The hypothesis proposes that these cues can become conditioned reinforcers of drug-taking behaviour. The receptors, which mediate the effects of nicotine on mesoaccumbens dopamine neurones, are desensitised by sustained exposure to nicotine at concentrations commonly found in the plasma of habitual smokers. It is proposed that, at times when the plasma nicotine concentration is sufficiently high to cause desensitisation of the receptors, tobacco smoking is maintained by the conditioned reinforcers present in the tobacco smoke. The hypothesis predicts, therefore, that conditioned reinforcement may play a more important role in the addiction to tobacco than for most other addictive behaviours. As a result, studies with nicotine have the potential to contribute to our understanding of the neurobiology of addiction which cannot easily be explored using drugs, such as cocaine and amphetamine, which invariably increase dopamine overflow in the forebrain.

Eryloside F, a novel penasterol disaccharide possessing potent thrombin receptor antagonist activity

We report the discovery of Eryloside F, a novel disaccharide of the steroidal carboxylic acid penasterol, isolated from an extract of the marine sponge Erylus formosus. The compound is a potent thrombin receptor antagonist, and furthermore inhibits human platelet aggregation in vitro.

Secobatzellines A and B, two new enzyme inhibitors from a deep-water Caribbean sponge of the genus Batzella

Secobatzelline A (1), a new batzelline natural analogue, and secobatzelline B (2), a likely artifact formed during the isolation procedure, have been isolated from a deep-water marine sponge of the genus Batzella. Secobatzellines A and B inhibited the phosphatase activity of calcineurin, and secobatzelline A inhibited the peptidase activity of CPP32. Both compounds showed in vitro cytotoxicity against P-388 and A-549 cell lines. The isolation and structure elucidation of secobatzellines A (1) and B (2) are described.

Discorhabdin P, a new enzyme inhibitor from a deep-water Caribbean sponge of the genus Batzella

Discorhabdin P (1), a new discorhabdin analogue, has been isolated from a deep-water marine sponge of the genus Batzella. Discorhabdin P (1) inhibited the phosphatase activity of calcineurin and the peptidase activity of CPP32. It also showed in vitro cytotoxicity against P-388 and A-549 cell lines. The isolation and structure elucidation of discorhabdin P (1) are described.

The 3' untranslated region of manganese superoxide dismutase RNA contains a translational enhancer element

A redox-sensitive protein that binds to the 3' untranslated region (UTR) of manganese superoxide dismutase (MnSOD) RNA has been described previously [Fazzone, H., Wangner, A., and Clerch, L. B. (1993) J. Clin. Invest. 92, 1278-1281; Chung, D. J., and Clerch, L. B. (1997) Am. J. Physiol. 16, L714-L719]. In the present study, cross-competition gel retardation and RNase H assays were used to identify a 41-base region located 111 bases downstream of the stop codon as the 3' UTR cis element involved in protein binding. The base sequence of this region is approximately 75% conserved among the 3' UTRs of rat, mouse, cow, and human MnSOD mRNAs at approximately the same distance downstream of the stop codon. The role of this protein-binding region in RNA translation was assessed in an in vitro rabbit reticulocyte lysate system. Translation of MnSOD RNA from which the 3' UTR element was deleted decreased 60% compared with translation of MnSOD RNA containing the 3' UTR cis element. In the presence of a specific competitor oligoribonucleotide that inhibits MnSOD RNA protein-binding activity, translation of MnSOD RNA containing the 3' UTR was decreased by 65%. Thus, both the cis element and RNA protein-binding activity were required for more efficient translation of the MnSOD. An analysis of ribosomal profiles suggests the MnSOD RNA-binding protein participates in the formation of the translation initiation complex. When MnSOD RNA-binding activity was inhibited, initiation complex formation was decreased by 50%. From the data obtained in this study, we propose that the 3' UTR cis element of MnSOD through its interaction with MnSOD RNA-binding protein may function as a translational enhancer.

An intronic polymorphism in the presenilin-1 gene does not influence the amount or molecular form of the amyloid beta protein deposited in Alzheimer's disease

The frequency of the allele-1 polymorphism in intron 8 of the presenilin-1 (PS-1) gene, and the proportion of individuals homozygous in this respect, was investigated in 57 patients with autopsy verified Alzheimer's disease (AD). In 33 of these patients the amount of amyloid beta protein (A beta) was compared across the three PS-1 genotype groups (1/1, 1/2, 2/2). No excess of the allele-1 was detected in these patients with confirmed AD and no variations in the extent of A beta deposition, as either A beta 40 or A beta 42, in terms of plaque number or percentage area of tissue occupied, were found. We conclude that this intronic PS-1 polymorphism does not influence the pathological phenotype of AD, at least as far as A beta deposition is concerned.

High dose rate intracoronary radiation for inhibition of neointimal formation in the stented and balloon-injured porcine models of restenosis: angiographic, morphometric, and histopathologic analyses

PURPOSE

We examined the effects of intracoronary irradiation delivered at a high dose rate on neointimal hyperplasia after injury induced by two methods: balloon overstretch injury, and stent implantation in a porcine model of coronary restenosis.

METHODS AND MATERIALS

In 34 Hanford miniature swine, a segment of each coronary artery was targeted for injury and treatment. The artery segments were treated with 192Ir at doses of 10 Gy over 4 min (eight animals), 15 Gy over 6 min (nine animals), 25 Gy over 10 min (nine animals) or control (simulation wire only; eight animals). The treated segments were subjected to stent implantation (left anterior descending and right coronary artery) or balloon overstretch (circumflex) injury. Twenty-eight days later, repeat coronary angiography and sacrifice were done. Quantitative coronary angiography, morphometry, and extensive histopathologic analyses were carried out in a blinded fashion.

RESULTS

The change in minimal lumen diameter from postinjury to presacrifice in the stent-injured left anterior descending was -0.79 +/- 0.34 (mean: +/- SD) mm in the control group, compared to -0.43 +/- 0.35 mm in the 15 Gy (p = 0.04) and -0.21 +/- 0.50 mm in the 25 Gy (p = 0.01) groups; and in the balloon-injured circumflex was -0.31 +/- 0.22 mm in the control group compared to -0.03 +/- 0.18 mm in the 10 Gy (p = 0.05) and 0.00 +/- 0.33 in the 15 Gy (p = 0.01) groups. Percent area stenosis in the left anterior descending was 36 +/- 9% in the control group compared to 18 +/- 12% in the 15 Gy (p = 0.003) and 11 +/- 11% in the 25 Gy (p < 0.001) groups; and in the circumflex was 16 +/- 10% in the control groups, compared to 5 +/- 5% in the 15 Gy (p = 0.02) and 2 +/- 2% in the 25 Gy (p = 0.009) groups. Histopathology showed a striking reduction in the amount of neointima in the irradiated arteries compared with control vessels. Other radiation effects were stromal fibrin exudate, thinning of the media, and adventitial fibrosis and leukocyte infiltration in the radiated arterial segments.

CONCLUSIONS

High dose rate intracoronary irradiation with 192Ir effectively inhibits intimal proliferation after stent-induced as well as balloon-overstretch injury. This shorter treatment time (4 to 10 min) may provide a clinically practical approach to the prevention of restenosis after angioplasty.

Characterization of an interleukin 6 cytokine family antagonist protein from a marine sponge, Callyspongia sp

An inhibitor of IL-6 binding to the human hepatoma line HepG2 and myeloma cell line U266 was identified in a saline extract of the marine sponge, Callyspongia sp. Functional activity, measured through the increase in haptoglobin production by HepG2 cells stimulated with IL-6, could be strongly inhibited by the extract. Similarly, IL-6-induced production of IgM by the B cell line SKW6.4 was substantially reduced. In neither cell line was there evidence of toxicity produced by the extract. Other sponges of the Callyspongia species were found to contain analogous activity. The activity was destroyed by trypsin treatment or boiling of the extract, suggesting that the inhibition is due to a protein. When the binding of IL-6 to its receptor complex was dissected in vitro, inhibition of binding of IL-6 to soluble receptor by the extract was not detected, but binding of the IL-6-sIL-6R complex to soluble gp130 was inhibited in a dose-dependent fashion. This was borne out in cellular assays since the extract inhibited activation of HepG2 cells stimulated with oncostatin M or leukemia inhibitory factor, cytokines which also use gp130 for signal transduction. These results suggest that the Callyspongia extract contains a protein which blocks the interaction of the IL-6 family of cytokines with their signal transduction moiety, gp130. Elucidation of the structure and mode of action of such a protein would be helpful in designing gp130 antagonists to inhibit the functions of this cytokine family, overproduction of which has been associated with cancer and pathologies of autoimmune disease and AIDS.

Lung manganese superoxide dismutase protein expression increases in the baboon model of bronchopulmonary dysplasia and is regulated at a posttranscriptional level

The expression of lung manganese superoxide dismutase (MnSOD) mRNA and protein were examined in a premature baboon model of hyperoxia-induced bronchopulmonary dysplasia (BPD) and BPD superimposed with bacterial infection. When 140-d gestation baboons were delivered by hysterotomy and treated for 16 d with appropriate ventilatory and oxygen support (pro re nada controls), there was an increase in both MnSOD mRNA and protein compared with 140-d or 156-d gestation, nonventilated controls. The concentration of MnSOD protein was also elevated when the prematurely delivered baboons were ventilated with a high fraction of inspired O2 to produce a primate homolog of BPD, but there was a significant decrease in the concentration of MnSOD mRNA in BPD animals compared with pro re nada controls. In the lungs of premature baboons in which Escherichia coli infection was superimposed on hyperoxia-induced BPD, MnSOD mRNA was diminished to approximately the same extent as in BPD alone, but MnSOD protein was significantly increased compared with all other groups. Taken together these data indicate that the premature baboon is capable of mounting an antioxidant response and that increased MnSOD protein expression in BPD and BPD-infected premature baboons is regulated, at least in part, at a posttranscriptional level.

Two possible mechanisms for survival and initiation of Murray Valley encephalitis virus activity in the Kimberley region of Western Australia

Two possible mechanisms are described for the initiation of Murray Valley encephalitis (MVE) virus activity in arid, epizootic regions of tropical Australia. Virus isolations were made from mosquitoes trapped shortly after the first heavy wet season rains and flooding in the east Kimberley, which followed approximately nine months of drought. A number of isolates of MVE virus were obtained, including isolates from pools of blood-engorged Culex annulirostris mosquitoes and from a single pool of male Aedes tremulus mosquitoes. The results strongly suggested that MVE virus activity was due both to its introduction in viremic vertebrate hosts, from which first-generation mosquitoes became infected following blood meals, and also to reactivation of vertically transmitted virus from desiccation-resistant eggs of Ae. tremulus. Both mechanisms are discussed with respect to environmental conditions.

Bis(sulfato)-cyclosiphonodictyol A, a new disulfated sesquiterpene-hydroquinone from a deep water collection of the Marine sponge Siphonodictyon coralliphagum

A new compound, bis(sulfato)-cyclosiphonodictyol A [1], which inhibits the binding of [3H]-LTB4 to intact human neutrophils with an IC50 value of 44 microM, was isolated from the sponge Siphonodictyon coralliphagum. The sponge was collected using the Johnson-Sea-Link manned submersible at a depth of 195 feet in the Bahamas. The compound was isolated via reversed-phase chromatography and its structure determined spectroscopically. To the best of our knowledge, 1 is the first marine-derived compound with two aromatic sulfate ester functionalities, and is also the first in the siphonodictyal series to contain an oxepane functionality.

Aplysillin A, a thrombin receptor antagonist from the marine sponge Aplysina fistularis fulva

Aplysillin A [1], an unusual disulfate ester of a 1,4-diphenyl-1,3-butadiene, was isolated from a deep water specimen of a sponge of the genus Aplysina. Its structure was determined through spectroscopic methods. The compound weakly inhibited binding to the thrombin receptor with an IC50 value of 20 microM.

The effect of an in-flight, emergency training program on crew confidence

INTRODUCTION

Despite some progress, the air medical transport profession continues to experience widely publicized accidents that result in injuries and death to crew members and patients. An air medical crew member's experience, training and confidence may affect his or her ability to deal effectively with an in-flight emergency, and may also affect his or her behavior before and after the emergency.

SETTING

A hospital-based, rural rotor- and fixed-wing program flying approximately 890 flights per year. Seventy-seven percent of these flights are interfacility.

METHODS

A pretraining survey evaluated the experiences of air medical crew members and pilots. A 20-question assessment tool based on a 5-point Likert scale evaluated how confident the individuals were in their ability to react to in-flight emergencies. An extensive in-flight emergency training program was then conducted. Personnel were asked to complete the same questionnaire one month and six months after the training.

RESULTS

On the pretraining questionnaire, flight crew members with neither prior training nor actual experience in in-flight emergencies showed the lowest level of confidence. Those with prior training, actual in-flight emergency experience or both, responded with higher levels of confidence. The mean confidence scores of the study participants increased from 82 pretraining to 89 at one month post-training and remained at the increased level six months after training.

CONCLUSIONS

A training program focusing on in-flight, aircraft-related emergencies can increase the crew's confidence during such situations. This increase in confidence is most noticeable in those without previous training or experience and is maintained for at least six months. Several other benefits occur from the training program.

Ross River virus isolations from mosquitoes in arid regions of Western Australia: implication of vertical transmission as a means of persistence of the virus

Outbreaks of mosquito-borne Ross River (RR) virus disease (epidemic polyarthritis) occur suddenly in the arid north and interior of the State of Western Australia, often within a few weeks of heavy rainfall. Between outbreaks, these regions may undergo long periods of drought, with little or no mosquito or arbovirus activity. The means by which RR virus is reintroduced or reactivated in these areas when environmental conditions favor mosquito-borne virus activity are unknown. In this paper, we describe isolations of RR virus from eight mosquito species trapped at two different locations, one coastal and one inland, in the arid Pilbara region of Western Australia, prior to outbreaks of epidemic polyarthritis. The isolation of RR virus has not been previously reported for five of these species and the isolations from the other three species are new records for Western Australia. The timing and number of isolations of RR virus from Aedes (Ochlerotatus) vigilax (Skuse, 1889) implicate that species as a vector of the virus on the Pilbara coast. Significantly, RR virus was isolated from pools of male Ae. vigilax and male Ae. (Macleaya) tremulus (Theobald, 1903) mosquitoes. This is the first report of RR virus (or other Australian arbovirus) isolates from wild-caught male mosquitoes. Both Ae. vigilax and Ae. tremulus have desiccation-resistant eggs that can survive long periods of drought, making them ideal candidates for the overwintering of arboviruses. The findings implicate vertical transmission as a means of persistence of RR virus in arid regions of Australia and therefore offer a likely explanation for the sudden recurrence of virus activity after heavy rains.

Isolation and structure elucidation of 34-sulfatobastadin 13, an inhibitor of the endothelin A receptor, from a marine sponge of the genus Ianthella

34-Sulfatobastadin 13 [1] was isolated from the sponge Ianthella sp. Its structure was elucidated by nmr techniques and chemical transformation to bastadin 13 [2]. Compound 1 weakly inhibited binding to the endothelin A receptor (ETA), while compound 2 inhibited growth of Bacillus subtilis.

Sesquiterpene-derived metabolites from the deep water marine sponge Poecillastra sollasi

Six sesquiterpene-derived compounds, 1-6, which we call sollasins a-f, have been isolated from a deep water specimen of the sponge Poecillastra sollasi. The structures were elucidated by comparison of spectral data to related metabolites and confirmed using spectroscopic methods. The compounds inhibit the growth of the pathogenic fungi Candida albicans and Cryptococcus neoformans and the P-388 and A-549 tumor cell lines. Compounds 3 and 4 show weak inhibition of binding of [125I] angiotensin II to rat aorta smooth muscle cell membranes.

An antiviral sesquiterpene hydroquinone from the marine sponge Strongylophora hartmani

A new sesquiterpene hydroquinone 1, which we call strongylin A, was isolated from the marine sponge Strongylophora hartmani. Its structure was determined through spectroscopic methods, including 2D-13C homonuclear correlation spectroscopy (INADEQUATE). Both 1 and its acetate derivative are active in in vitro assays against the P-388 tumor cell line and influenza strain PR-8.

Isolation of fetal trophoblast cells from peripheral blood of pregnant women

Fetal trophoblast cells were isolated from maternal peripheral blood by means of murine monoclonal antibodies of high specificity and affinity for human syncytiotrophoblast and nonvillous cytotrophoblast cells. The cells were isolated in sufficient numbers to allow polymerase chain reaction (PCR) amplification of the Y-chromosome-specific DNA sequence from the peripheral blood of thirteen pregnant women. The fetal sex predicted by PCR analysis of the isolated trophoblast cells accorded with that ascertained by karyotyping of chorionic villus samples in eleven of twelve women studied in early pregnancy and with the sex of the baby on delivery in one woman studied at 34 weeks' gestation. Isolation of these fetal cells could allow noninvasive diagnosis of a wide range of inherited disorders.

In vitro assays to study role of T cell-derived factors on human B lymphocytes should take into consideration inhibiting effect of large granular lymphocyte subset (CD5-,CD16+) that can contaminate B cell preparations

In these studies, the inhibitory role of a large granular lymphocyte (LGL) subset (CD5-,CD16+) on pokeweed mitogen (PWM)-induced B lymphocyte differentiation was examined. CD5-,CD16+ LGL cells are the predominant subset of LGL cells and are possibly distinct from other LGL subsets in that they lack B and T cell markers. CD5-,CD16+ LGL possess abundant FcIgG receptors and previous studies have clearly demonstrated that in the presence of insoluble immune complexes, this LGL subset will inhibit B lymphocyte differentiation in the presence of T cells. In the present studies, we analyzed the inhibiting role of CD5-,CD16+ LGL cells that had not been activated by immune complexes. B + L preparations obtained by removal of E rosette-forming T cells were further depleted of T lymphocytes by complement-dependent lysis of T cells using a monoclonal antibody reactive to total T cells (Leu-1, CD5 antigen, Becton-Dickinson). B lymphocytes in such B + L preparations failed to differentiate into plasma cells containing intracytoplasmic immunoglobulin (Ig), in the presence of PWM, T cell-derived helper supernatants (THS), and interleukin-2 (IL-2). However, B cells differentiated under these conditions, when B + L preparations were further depleted of CD5-,CD16+ LGL cells by complement-dependent lysis using a monoclonal antibody (Leu-11) reactive to CD16 antigen of FcIgG receptors present on LGL cells. These studies indicated that CD5-,CD16+ cells unlike the CD8-positive T suppressor cell, will directly inhibit B lymphocyte differentiation into plasmacytoid cells containing intracytoplasmic Ig when T lymphocytes are not present. However, addition of a few T lymphocytes (less than 10%) to purified B + L preparations abrogated the CD5-,CD16+ LGL cell inhibition of B cell differentiation.

Water quality control trials: statistical tables for direct comparison between membrane filtration bacterial counts and the multiple tube method with a description of the bacteriological method

Experiments in the quality control of water samples are being conducted in the Public Health Laboratory Service and the water industry in the United Kingdom. The number of distributions which have been made is 7 and 92 laboratories are now participating. The methods used for preparing and distributing samples are described. Some participating laboratories use the multiple tube method and some use membrane filtration to assess the presence of coliforms and Escherichia coli. The results are, therefore, a mixture of estimated numbers and direct colony counts. In order to compare results from these two different laboratory methods statistical tables have been compiled to show the most likely multiple tube result corresponding to each colony count. Tables relating to two commonly used tenfold dilution series are presented. To illustrate how these tables may be used we present results from a typical quality control distribution. The analyses of these results are generally satisfactory but show a tendency for lower counts using the membrane filtration method and more false negative results with E. coli counts.

Control of infection in general practice: a survey and recommendations

Twenty general practices in four areas in Britain were surveyed to establish their needs for and practices of sterilising and disinfecting equipment. Of the 327 items of equipment and instruments examined in the survey, 190 were satisfactorily decontaminated, 100 were treated in a way judged to result in doubtful decontamination, and in 37 cases treatment was considered unsatisfactory. Decontamination apparatuses (autoclaves, hot air ovens, and hot water disinfectors) were generally in good working order, but the use of chemical disinfectants was often inappropriate. Recommendations were made on appropriate methods of decontamination for various items in common use in general practice. By virtue of the large numbers of patients treated by general practitioners there is a substantial possibility of transmitting infection; having appropriate methods for decontaminating instruments and equipment is therefore imperative.