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PubMed1993

Long-term consequences of childhood physical and sexual abuse.

Psychiatric nurses are confronted daily with individuals who are suffering from the consequences of trauma. Physical and sexual abuse is associated with acute psychiatric symptomatology in children and may progress to a spectrum of psychiatric and medical disorders in adults, ranging from the extreme adaptive reactions seen in multiple personality disorder and refractory psychosis to intermediate adaptive reactions present in borderline personality disorder to more delimited reactions manifest in chronic headaches and unremitting pelvic pain. Subjects sampled in inpatient, outpatient, psychiatric, medical, criminal, and community settings describe the link between histories of widespread abuse and various intractable and common disorders. This article presents the state-of-the-art knowledge of the long-term sequelae of childhood physical and sexual abuse by critically reviewing the initial uncontrolled investigations and mounting evidence from controlled studies.

Adolescent↗
PubMed2007

Enzyme enhanced solid-state fermentation of kenaf core fiber for storage and pretreatment.

Kenaf is an annual fiber crop adaptable to a wide range of climates and soil types. This study investigated the use of kenaf core fiber as a feedstock for enzyme-enhanced fermentation. Triplicate kenaf core fiber samples were treated with enzymes having cellulase:hemicellulase activity ratios of 0:1, 0.015:1, 0.45:1, and 2.54:1 at a rate of 5010 IU/kg dry matter hemicellulase activity, vacuum-sealed, and incubated at 37 degrees C for 21 d. Samples were analyzed for pH, water soluble carbohydrates, organic acids, and hemicellulose and cellulose concentrations. All treatments produced a pH less than 4.0, which is sufficient for stable storage. Treatments with 2.54:1 and 0.45:1 produced the highest water soluble carbohydrate and lactic acid concentrations. Enzymes with no or low cellulase activity produced results similar to the control. Utilizing enzyme mixtures with high cellulase activity is an effective pretreatment method for ensiled kenaf core fiber.

Carbohydrates↗
PubMed2005

Unraveling biochemical properties of cockroach (Periplaneta americana) proteinases with a gel X-ray film contact print method.

Eleven proteinase activity bands were detected in American cockroach (Periplaneta americana) gut. These were partially purified and characterized using a gel X-ray film contact print method. Cockroach gut proteinases (CGPs) show activity over a broad range of pH with maximum activity between pH 6 and 10, and optimal activity at 50-70 degrees C. CGPs were partially purified by preparative gel electrophoresis and analyzed using synthetic substrates and inhibitors. Four of the proteases exhibited chymotrypsin-like (C1 to C4) activity and seven trypsin-like (T1 to T7) activity. Accuracy of the gel X-ray film contact print method is confirmed by including bovine chymotrypsin in CGP analysis. Inhibition of CGPs with different plant proteinaceous proteinase inhibitors allowed identification of potential CGP inhibitors. Our results imply that presence of several CGP activity bands, and their stability and activity over a broad pH and temperature range might contribute to adaptation of P. americana to extreme environmental conditions and the polyphagous nature of the species.

Animals↗
PubMed2004

Infectious diseases in the 21st century: old challenges and new opportunities.

Infectious diseases are the confrontation of two worlds, the microbial world and the world of human physiology. Although these two worlds are as a whole governed by the same laws of nature, they show substantial differences: the microbiological world is 1000 times older, and was initiated by the development of the archaea, the 'living organisms of the extreme': its biomass and its diversity are immense - two to three billion species or 60% of the total biomass of the planet. The number of pathogens that adapted to man, however, is extremely limited - barely 1000. Thus, over billions of years, an evolution of the microbial world took place from 'early life', characterized by chemosynthesis, to the 'modern pathogens', and entailed a dramatic 'concentration' of life conditions and an adaptation towards a narrow range of requirements - those allowing survival in the human body. Within the last two centuries, these two slowly evolving systems, microbial life and human life, were profoundly modified in an unprecedented manner by a third player, human civilization, with its global impact on the environment through physical, chemical, societal, and climatic determinants. An appreciation of the evolution of infectious diseases in the 21st century and of the development of new diagnostic and therapeutic strategies therefore requires a full understanding of these three domains: human physiology, microbiology, and the environment. This review will put major emphasis on the environmental role of civilization on infectious diseases before considering new opportunities to combat them through novel and creative solutions.

Civilization↗
PubMed2003

Pandemic influenza-implications for critical care resources in Australia and New Zealand.

OBJECTIVES: To quantify resource requirements (additional beds and ventilator capacity), for critical care services in the event of pandemic influenza. MATERIALS AND METHODS: Cross-sectional survey about existing and potential critical care resources. Participants comprised 156 of the 176 Australasian (Australia and New Zealand) critical care units on the database of the Australian and New Zealand Intensive Care Society (ANZICS) Research Centre for Critical Care Resources. The Meltzer, Cox and Fukuda model was adapted to map a range of influenza attack rate estimates for hospitalisation and episodes likely to require intensive care and to predict critical care admission rates and bed day requirements. Estimations of ventilation rates were based on those for community-acquired pneumonia. RESULTS: The estimated extra number of persons requiring hospitalisation ranged from 8,455 (10% attack rate) to 150,087 (45% attack rate). The estimated number of additional admissions to critical care units ranged from 423 (5% admission rate, 10% attack rate) to 37,522 (25% admission rate, 45% attack rate). The potential number of required intensive care bed days ranged from 846 bed days (2 day length of stay, 10% attack rate) to 375,220 bed days (10 day length of stay, 45% attack rate). The number of persons likely to require mechanical ventilation ranged from 106 (25% of projected critical care admissions, 10% attack rate) to 28,142 (75% of projected critical care admissions, 45% attack rate). An additional 1,195 emergency ventilator beds were identified in public sector and 248 in private sector hospitals. Cancellation of elective surgery could release a potential 76,402 intensive care bed days (per annum), but in the event of pandemic influenza, 31,150 bed days could be required over an 8- to 12-week period. CONCLUSION: Australasian critical care services would be overwhelmed in the event of pandemic influenza. More work is required in relation to modelling, contingency plans, and resource allocation.

Australia↗
PubMed2005

Antimicrobial and insecticidal protein isolated from seeds of Clitoria ternatea, a tropical forage legume.

The tropical forage legume Clitoria ternatea (L.) has important agronomic traits such as adaptation to a wide range of soil conditions and resistance to drought. It is resistant to a number of pathogens and pests. These important traits gave us reasons to look more closely at the plant. A highly basic small protein was purified from seeds of C. ternatea to homogeneity by using ultrafiltration with Centricon-3 membrane tubes and preparative granulated-bed isoelectric focusing (IEF). A single protein band was obtained on both sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and IEF gels. The protein, designated 'finotin', has broad and potent inhibitory effect on the growth of various important fungal pathogens of plants, namely Rhizoctonia solani, Fusarium solani, Colletotrichum lindemuthianum, Lasiodiplodia theobromae, Pyricularia grisea, Bipolaris oryzae and Colletotrichum gloeosporioides. It also inhibits the common bean bacterial blight pathogen Xanthomonas axonopodis pv. phaseoli. Moreover, finotin has powerful inhibitory properties against the bean bruchids Zabrotes subfasciatus and Acanthoscelides obtectus.

Animals↗
PubMed2005

The constitutively active N111G-AT1 receptor for angiotensin II modifies the morphology and cytoskeletal organization of HEK-293 cells.

The expression of a constitutively active G protein-coupled receptor is expected to trigger diverse cellular changes ranging from normal to adaptive responses. We report that confluent HEK-293 cells stably expressing the constitutively active mutant N111G-AT1 receptor for angiotensin II spontaneously exhibited dramatic morphological changes and cytoskeletal reorganization. Phase-contrast microscopy revealed that these cells formed a dense monolayer, whereas cells expressing the WT-AT1 receptor displayed large intercellular spaces and numerous filopodia. Confocal microscopy revealed an elaborate web of polymerized actin at the apical and basolateral surfaces of cells expressing the N111G-AT1 receptor. Interestingly, these phenotypic changes were prevented by culturing the cells in the presence of the inverse agonist EXP3174. Similar morphologic rearrangements and de novo polymerized actin structures were found in Ang II-stimulated cells expressing the WT-AT1 receptor. We further showed that AT1 receptor-induced cell-cell contact formation did not require an increase in intracellular Ca2+ concentration or the activity of protein kinase C. However, pretreatment with Y-27632 revealed that Rho-kinase activity was required for cell-cell contact formation upon AT1 receptor activation. These observations demonstrate that the expression of the constitutively active mutant N111G-AT1 receptor had a significant impact on the morphology and cytoskeletal organization of HEK-293 cells, possibly via a mechanism involving the activity of Rho-kinase.

Angiotensin II↗
PubMed2003

Nonradioactive methods for the assay of phosphoinositide 3-kinases and phosphoinositide phosphatases and selective detection of signaling lipids in cell and tissue extracts.

We describe a novel approach to quantitation of phosphoinositides in cell extracts and in vitro enzyme-catalyzed reactions using suitably tagged and/or labeled pleckstrin homology (PH) domains as probes. Stable complexes were formed between the biotinylated target lipid and an appropriate PH domain, and phosphoinositides present in samples were detected by their ability to compete for binding to the PH domain. Complexes were detected using AlphaScreen technology or time-resolved FRET. The assay procedure was validated using recombinant PI 3-kinase gamma with diC8PtdIns(4,5)P(2) as substrate and general receptor for phosphoinositides-1 (GRP1) PH domain as a PtdIns(3,4,5)P(3)-specific probe. This PI 3-kinase assay was robust, was suitable for high-throughput screening platforms, and delivered expected IC(50) values for reference compounds. The approach is adaptable to a wide range of enzymes as demonstrated by assays of the tumor suppressor protein, PTEN, a phosphoinositide 3-phosphatase, which was measured using the same reagents but with diC8PtdIns(3,4,5)P(3) as substrate. PtdIns(3,4,5)P(3) present in lipid extracts of Swiss 3T3 and HL60 cells stimulated with platelet-derived growth factor and fMLP, respectively, was also detectable at picomole sensitivity. The versatility and general utility of this approach were demonstrated by exchanging the GRP1 PH domain for that of TAPP1 (which binds PtdIns(3,4)P(2) and not PtdIns(3,4,5)P(3)). This system was used to monitor the accumulation of PtdIns(3,4)P(2) in Swiss 3T3 cells exposed to an oxidative stress. It is therefore proposed that similar procedures should be capable of measuring any known phosphoinositide present in cell and tissue extracts or produced in kinase and phosphatase assays by using one of several well-characterized protein domains with appropriate phosphoinositide-binding specificity.

3T3 Cells↗
PubMed2003

Synthesis of a radioactive thiol reagent, 1-S-[3H]carboxymethyl-dithiothreitol: identification of the phosphorylation sites by N-terminal peptide sequencing and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry.

A novel radioactive thiol reagent, 1-S-[3H]carboxymethyl-dithiothreitol (DTT-S-C[3H(2)]CO(2)H, [3H]CM-DTT), was designed and synthesized at the micromole level by reaction of dithiothreitol with tritiated iodoacetic acid (I-C[3H(2)].CO(2)H). The reaction progress was followed by reverse-phase high-performance liquid chromatography (RP-HPLC) and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. The usefulness of the synthesized reagent was evaluated in a series of experimental approaches. (i) The synthetic phosphopeptide, NSVS(P)EEGRGDSV, was derivatized by [3H]CM-DTT separated from excess reagent by RP-HPLC. The extent of derivatization was quantitated in terms of the mol of P-Ser/mol of peptide by 3H counting, and the location of the phosphoserine was defined by the N-terminal Edman degradation sequence analysis as being the fourth amino acid residue from the N terminus. (ii) A sample of trypsin-digested alpha-casein was derivatized with [3H]CM-DTT, peptides were separated by RP-HPLC, and aliquots of each fraction were counted for 3H label within the peptide map which rapidly pinpointed the original four phosphoserine-containing peptides. This demonstrated the utility of the synthesized radioactive thiol agent in rapid purification and identification of phosphopeptides from HPLC peptide mapping of proteolytic digests of phosphoproteins. (iii) The [3H]CM-DTT was also used to determine the extent of phosphorylation of phosphoproteins both qualitatively by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and autoradiography and quantitatively by 3H counting. The synthesized radioactive thiol reagent [3H]CM-DTT proved to be very efficient and sensitive and should be adaptable to a wide range of routinely utilized laboratory approaches in many fields of the biological sciences.

Binding Sites↗
PubMed2003

The X-ray structure of Escherichia coli RraA (MenG), A protein inhibitor of RNA processing.

The Escherichia coli protein regulator of RNase E activity A (RraA) has recently been shown to act as a trans-acting modulator of RNA turnover in bacteria; it binds to the essential endonuclease RNase E and inhibits RNA processing in vivo and in vitro. Here, we report the 2.0A X-ray structure of RraA. The structure reveals a ring-like trimer with a central cavity of approximately 12A in diameter. Based on earlier sequence analysis, RraA had been identified as a putative S-adenosylmethionine:2-demethylmenaquinone and was annotated as MenG. However, an analysis of the RraA structure shows that the protein lacks the structural motifs usually required for methylases. Comparison of the observed fold with that of other proteins (and domains) suggests that the RraA fold is an ancient platform that has been adapted for a wide range of functions. An analysis of the amino acid sequence shows that the E.coli RraA exhibits an ancient relationship to a family of aldolases.

Aldehyde-Lyases↗
PubMed1994

Mechanisms of alcohol abuse and alcoholism in adolescents: a case for developing animal models.

This paper reviews the ontogeny of neurotransmitter systems and neuropharmacological challenge within transmitter systems and discusses the actions of alcohol on such systems during the juvenile through adolescent periods. To place the animal research within the context of human development, an attempt is made to first examine some fundamental principles of developmental research as they relate to the adolescent period. Evidence presented from animal studies indicates that unique neurochemical and behavioral changes are occurring during postnatal development, including adolescence, that could mediate the response to alcohol. The limited number of studies on the neurochemical and behavioral response to alcohol during adolescence has employed rats and has been restricted by the relatively brief adolescent period in that species. While one alternative is to use primates, it is suggested that innovative behavioral paradigms be developed for adolescent animals in other species to study behaviors such as alcohol self-administration or alcohol stimulus discrimination. It is also suggested that existing behavioral models that are more easily adapted to younger age ranges (e.g., conditioned place preference, conditioned taste aversion, thermal response to ethanol) be extended to make ontogenetic comparisons through adolescence and adulthood. This may further our understanding of alcohol's immediate consequences during each maturational stage and, more important, the contribution of early alcohol exposure to excessive drinking and abnormal cognitive and social functioning during subsequent stages of development.

Adolescent↗
PubMed2000

Quantitating silver-stained neurodegeneration: the neurotoxicity of trimethlytin (TMT) in aged rats.

This report describes the development of a histoanalytical procedure to measure the degree of neurodegeneration produced by the organometal toxicant trimethyltin (TMT). Based on a previous, non-quantitated experiment we hypothesized that the same dose of TMT would produce greater damage in animals of increasing age. Male rats aged 6, 12, 18, or 24 months at the time of dosing were given either 4.5 mg/kg TMT or saline (i.p.). One month after dosing, rats were perfused and their brains removed and processed to selectively silver-impregnate degenerating cell bodies as well as axon terminals and dendrites. Neurodegeneration was most prominent in the hippocampi (especially CA1 stratum radiatum) of TMT-treated rats, but not in the controls. Computer-assisted counting of the silver grains marking damage indicated greater neurotoxicity from the same dose of TMT when given to the older animals. Thus the grain density in the 6-month-old TMT-treated rats was not significantly elevated from the 6-month-old controls (P>0.10). The 12-month-old TMT-treated rats had significantly increased grain densities compared to their controls (P<0.05), but still larger increases of grain counts were observed in the 18- and 24-month-old rats (both P-values<0.01). Our findings with TMT are similar to previous, but nonquantitative, reports that the neurotoxic effects of kainic acid and methionine sulfoximine were also greater in older rats. An increased sensitivity to neurotoxicants might help explain the apparently spontaneous degeneration of cortical neurons in aging and in the neurological diseases of old age. The method we report here for quantitation of silver grains marking neurodegeneration should be adaptable to a wide range of histologically-based neurotoxicology investigations.

Aging↗
PubMed1999

A quantitative assessment of the validity of animal-health surveys using stochastic modelling.

This paper presents a stochastic simulation model to evaluate the efficacy of regional or national surveys aimed at identifying infection in populations of animals. The process of evaluation involves specification or calculation of cluster-level test sensitivity and specificity, which are derived from two probability distributions of the number of individual-level positive tests expected from non-infected and infected clusters, respectively. Probability distributions for the number of positive clusters expected in a situation of freedom from infection and under various levels of cluster prevalence are specified and used to determine survey properties (the survey being considered a diagnostic system), and ROC curves are drawn. Likelihood ratios allow investigators to state the extent to which a survey result is more likely to be observed if the region or country is infected at a given prevalence than if it is free from infection. The result of a survey carried out to investigate the presence of porcine reproductive and respiratory syndrome (PRRS) in Switzerland is used to illustrate this approach. The model can be adapted to a wide range of survey designs.

Animals↗
PubMed1998

Germination and seedling development of switchgrass and smooth bromegrass exposed to 2,4,6-trinitrotoluene.

It is estimated that explosives contaminate approximately 0.82 million cubic metres of soil at former military installations throughout the US; major contaminants often include 2,4,6-trinitrotoluene (TNT) and its degradation products. At some sites, phytoremediation may be a viable option to incineration or other costly remediation treatments. Grasses may be particularly suited for remediation because of their growth habit and adaptability to a wide range of soil and climate conditions. We characterized the effects of TNT on germination and early seedling development of switchgrass and smooth bromegrass to evaluate their potential use on contaminated sites. Switchgrass and smooth bromegrass seeds were germinated in nutrient-free agar containing 0 to 60 mg TNT litre(-1). Smooth bromegrass germination decreased as TNT concentration increased, while switchgrass germination was unaffected by TNT. Concentrations up to 15 mg TNT litre(-1) did not affect switchgrass root growth rate, but bromegrass root growth was reduced at TNT concentrations above 7.5 mg litre(-1). At 7.5 mg TNT litre(-1), however, shoot growth rate was reduced in both species. Examination at 20-fold magnification revealed switchgrass radicles were unaffected by TNT, while smooth bromegrass radicles appeared slightly swollen. Results indicate switchgrass is more tolerant of TNT than smooth bromegrass, but the establishment of both species may be limited to soil containing less than 50 mg kg(-1) of extractable TNT.

Journal Article↗
PubMed2001

[Adipofascial flaps of the frontal-internal part of the leg: an alternative to free flaps for the repair of skin loss from the knee to the ankle. Report of a clinical experience with 17 cases].

Leg coverage remains a difficult challenge for plastic surgeon, especially in certain areas. Although treatment of osteomyelitis is well established, coverage of bone, tendinous or hardware exposure remain controversial. In these selected cases, adiposofascial pedicled flaps should constitute a interesting solution. The multiples vascular supplies to the adiposofascial tissue of the medial side of the leg constitute de basis of this flap family. These condition allows an extreme adaptability to a wide range of defect with maximal satisfaction.

Dermatologic Surgical Procedures↗
PubMed1999

Rapid determination of artemisinin and related analogues using high-performance liquid chromatography and an evaporative light scattering detector.

Artemisinin and its analogues are a class of compounds of current interest in the treatment of drug-resistant malaria. These antimalarials are preferentially taken up into malaria infected erythrocytes as compared to uninfected erythrocytes, a fact that may represent an important parameter in drug potency. Numerous methods for the analysis of specific artemisinin analogues have been developed, but most are not widely adaptable to a large range of analogues. In this paper we describe a high-performance liquid chromatographic method developed and validated for artemisinin and several analogues of artemisinin using a readily available evaporative light scattering detector. This quantitation method was found to be straight forward, rapid, inexpensive and reproducible. Standard calibration curves constructed for six artemisinin compounds were linear with the detection limit determined between 6 and 60 ng. The intra- and inter-day accuracy were found to be 2.75% and 4.15%, respectively with less than 3% variation in precision. The validated assay was applied to a mixture of artemisinin derivatives, where they were easily separated and quantitated.

Antimalarials↗
PubMedDate not supplied

Response properties of long-range axon-bearing amacrine cells in the dark-adapted rabbit retina.

Axon-bearing amacrine cells in mammalian retinae are encountered relatively infrequently during electrophysiological investigations, and thus very little is known about their physiological properties. Patch-clamp electrodes were used to record light responses from two axon-bearing amacrine cells in flat-mounted, dark-adapted rabbit retina. The recorded cells were stained, and the morphology visualized. Both cells were capable of generating action potentials. In one case, a linear relationship between mean depolarization and action-potential frequency was demonstrated. The cells had a proximal dendritic arbor and a morphologically distinct, much larger axon terminal system. The receptive field of the center response was coextensive with the dendritic arbor, and thus also much smaller than the axon terminal system. The center response was suppressed by activation of an inhibitory surround. Both cells responded to center illumination with an inward current which became more transient as the size of the illuminating spot was increased. It is suggested that axon-bearing amacrine cells receive input over a receptive field defined by the dendritic arbor, and distribute their output over a much more extensive axon terminal system, most probably via action potentials.

Action Potentials↗
PubMed1992

Light adaptation, rods, and the human cone flicker ERG.

During the course of light adaptation, the amplitude and implicit time of the human cone ERG change systematically. In the present study, the effect of adapting field luminance on these ERG changes was assessed, and the hypothesis that light adaptation of the rod system is the primary determining factor was evaluated. Cone ERG responses, isolated through the use of 31.1-Hz flicker, were obtained from two visually normal subjects, initially under dark-adapted conditions and then repeatedly for 30 min following the onset of each of a series of ganzfeld adapting fields with luminances that ranged from -1.2 to 2.1 log cd/m2. The increase in flicker ERG amplitude and decrease in implicit time during light adaptation were greatest at the highest adapting field luminances. Photopically equivalent achromatic and long-wavelength adapting fields induced comparable increases in flicker ERG amplitude, while scotopically equivalent adapting fields had considerably different effects. This latter finding demonstrates that the rod system is not a major determinant of the adaptation-induced increase in cone ERG amplitude.

Adaptation, Ocular↗