Deamidations in recombinant human phenylalanine hydroxylase. Identification of labile asparagine residues and functional characterization of Asn --> Asp mutant forms.

Recombinant human phenylalanine hydroxylase (hPAH) expressed in Escherichia coli for 24 h at 28 degrees C has been found by two-dimensional electrophoresis to exist as a mixture of four to five molecular forms as a result of nonenzymatic deamidation of labile Asn residues. The multiple deamidations alter the functional properties of the enzyme including its affinity for l-phenylalanine and tetrahydrobiopterin, catalytic efficiency, and substrate inhibition and also result in enzyme forms more susceptible to limited tryptic proteolysis. Asn(32) in the regulatory domain deamidates very rapidly because of its nearest neighbor amino acid Gly(33) (Solstad, T.

Antimicrobial activity of essential oils isolated from Portuguese endemic species of Thymus.

Aims: Thymus species are wild species mostly found in the arid lands of Portugal. Possible antimicrobial properties of Thymus essential oils have been investigated. The chemical composition of the essential oils and the antimicrobial activity of Thymus mastichina (L) L.

Antimicrobial terpenoids from the oleoresin of the Peruvian medicinal plant Copaifera paupera.

Twelve known diterpenes 1 - 11 and 13, and three known sesquiterpenes 14 - 16, along with a new C(20) - C(15) terpenoid 17, with a structure based on an unprecedented skeleton in which a labdane diterpene is linked to a monocyclic sesquiterpene by an ester bridge, were isolated from the oleoresin of the Peruvian medicinal plant Copaifera paupera (Herzog) Dwyer (Leguminosae). Their structures were elucidated on the basis of spectral analysis, including homo- and heteronuclear correlation NMR experiments (COSY, ROESY, HMQC and HMBC), and by comparison with data in the literature. The leishmanicidal, antimicrobial, cytotoxic, and aldose reductase inhibitory activities were studied.

Finding the findings in qualitative studies.

Purpose: To describe the challenges of finding the findings in qualitative studies.

Method: Review of literature on representation in qualitative research and analysis of 99 reports of qualitative studies of women with HIV infection.

Findings: Factors complicating finding the findings in qualitative studies include varied reporting styles, misrepresentation of data and analytic procedures as findings, misuse of quotes and theory, and lack of clarity concerning pattern and theme.

Progression to AIDS, a clinical AIDS condition and mortality: psychosocial and physiological predictors.

Background: The primary aim of this study is to examine prospectively the association of stressful life events, social support, depressive symptoms, anger, serum cortisol and lymphocyte subsets with changes in multiple measures of human immunodeficiency virus (HIV) disease progression.

Methods: Ninety-six HIV-infected gay men without symptoms or anti-retroviral medication use at baseline were studied every 6 months for up to 9 years. Disease progression was defined in three ways using the Centers for Disease Control (CDC) classifications (e.

Predicting fatigue and depression in HIV-positive gay men.

HIV-related fatigue is a prevalent and troubling symptom for HIV-positive people. The purpose of the study was to develop a model for predicting fatigue and depression among HIV-positive gay men as a function of history of fatigue and depression in the previous year and to determine whether psychological and psychosocial variables or physiologic variables better predict fatigue. Data from 96 HIV-positive gay men followed longitudinally for up to 7.

Neuropsychological test performance of patients with Friedreich's ataxia.

Although recognized as one of the most common hereditary diseases of the nervous system, the neuropsychological deficits in Friedreich's ataxia (FA) have rarely been studied. A protocol was constructed to assess the major cognitive areas in patients with FA and pair-matched normal controls. Motor difficulties, dysarthria and fatigability were taken into account.

Delayed pursuit of health care among HIV-positive gay men enrolled in a longitudinal research study.

The aim of this qualitative article is to describe the reasons HIV-positive gay men who are enrolled in a longitudinal research project give for not initiating health care. Extreme sampling techniques were used to recruit four HIV-positive gay men who are enrolled in a research project that is examining factors related to disease progression in HIV infection but who do not otherwise receive any health care. Intensive, open-ended interviews were conducted, and the interviews were analyzed for recurring themes.

Reactive oxygen species, antioxidant systems and nitric oxide in peroxisomes.

Peroxisomes are subcellular organelles with an essentially oxidative type of metabolism. Like chloroplasts and mitochondria, plant peroxisomes also produce superoxide radicals (O2*(-)) and there are, at least, two sites of superoxide generation: one in the organelle matrix, the generating system being xanthine oxidase, and another site in the peroxisomal membranes dependent on NAD(P)H. In peroxisomal membranes, three integral polypeptides (PMPs) with molecular masses of 18, 29 and 32 kDa have been shown to generate radicals O2*(-).

[Cervical spondylodiscitis].

Eighty patients were treated for spondylodiscitis with the cervical spine involved in nine cases. Conservative treatment was applied in seven cases with Minerva jacket and antibiotics, and surgical treatment was applied in severe, rapidly, progressive, complicated cases and in patients with involvement of nervous system (two cases). The good and satisfactory results in both group were similar.

(1-->6)-Beta-D-glucan as the cell wall binding site for Debaryomyces hansenii killer toxin.

Aims: The aims of this study were to characterize the cell wall binding site of Debaryomyces hansenii killer toxin to provide a simple purification method and to determine some characteristics of this toxin.

Methods And Results: Various linear (1-->6)-beta-D-glucans of different origins were effective competitive inhibitors of the toxin action. Periodate oxidation and 1H-NMR was used to determine the receptor nature.

Psychometric properties of the HIV-Related Fatigue Scale.

The HIV-Related Fatigue Scale (HRFS) was developed to address the specific aspects of fatigue experienced by people who are HIV-positive and are not measured in any commonly used fatigue scale. The necessity for a new scale was determined after analysis of a qualitative study to explore HIV-related fatigue in which it was found that HIV-related fatigue has components related to intensity, circumstances, and consequences that must be included in the measurement of fatigue for this population. The HRFS has 56 items, most of which are on a 1-to-10 scale, drawn from five existing fatigue scales and the data from this qualitative study.

Production and characteristics of Debaryomyces hansenii killer toxin.

The optimal conditions for the production of the killer toxin of Debaryomyces hansenii CYC 1021 have been studied. The lethal activity of the killer toxin increased with the presence of NaCl in the medium used for testing the killing action. Production of the killer toxin was stimulated in the presence of proteins of complex culture media.

Growth, protein-turnover rates and nucleic-acid concentrations in the white muscle of rainbow trout during development.

We have studied the growth rate, nucleic-acid concentration, protein-accumulation rate (K(G)), and several other parameters relating to protein turnover, such as the protein-synthesis (K(S)), and protein-degradation rates (K(D)), protein-synthesis capacity (C(S)), protein-synthesis efficiency (K(RNA)), protein-synthesis rate per DNA unit (K(DNA)) and protein-retention efficiency (PRE), in the white muscle of rainbow trout during development. Both growth rate and relative food intake decreased significantly with age and weight, as did the food-efficiency ratio (FER) and protein-efficiency ratio (PER). Although absolute RNA and DNA contents increased with age, their relative concentrations decreased.

In the field with the Beck depression inventory.

Qualitative methods are typically and formally used only in the earliest phases of instrument development to generate items. Once these items are generated, instrument development usually then moves into the testing phases, where quantitative methods prevail. The achievement of psychometric credibility is presumed to depend largely on quantitative measures of reliability and validity.

[Congenital synostoses of the tarsus. Concept, classification, diagnosis and therapeutic approach].

The incidence of congenital tarsal coalition is about 1%. It is recognized as the main etiology of painful, rigid flatfoot in the pediatric population. Talonavicular (50%) and talocalcaneal (40%) coalition are the most common presentation.

Transient up-regulation of liver mitochondrial thymidine kinase activity in proliferating mitochondria.

Administration of the fatty acid analogue tetradecylthioacetic acid (TTA) to rodents up-regulates peroxisomal and mitochondrial lipid-metabolizing enzymes and induces a proliferation of these organelles in hepatocytes. We show here that male NMRI mice fed a diet containing 0.3% (w/w) TTA revealed a transient two-fold increase in the incorporation of [3H]thymidine into the liver mtDNA followed by a 1.

Immunohistochemical localisation of neuronal nitric oxide synthase in the rainbow trout kidney.

The distribution of nitrergic nervous structures in the trout kidney was studied by peroxidase-linked ABC immunostaining procedures using a polyclonal antibody raised against the neuronal isoform of nitric oxide synthase. The nitrergic plexus reaches the kidney along the vasculature, mainly running with the postcardinal vein where nitrergic fibres, microganglia like cellular clusters and isolated neurones were detected. The atubular head-kidney only showed isolated nitrergic fibres close to the larger arteries.

Carbohydrate deprivation reduces NADPH-production in fish liver but not in adipose tissue.

Little is known about the way in which carnivorous fish such as salmonids mobilise and metabolise dietary carbohydrates, which are essential to lipid metabolism. Thus we have studied changes caused by the absence of dietary carbohydrates to the kinetics and molecular behaviour of the four cellular NADPH-production systems [glucose 6-phosphate dehydrogenase (G6PDH); 6-phosphogluconate dehydrogenase (6PGDH); malic enzyme (ME); and isocitrate dehydrogenase NADP-dependent (NADP-IDH)] in the liver and adipose tissue of rainbow trout (Oncorhynchus mykiss). We used spectrophotometry to study enzyme kinetics and nucleic acid concentrations, and immunoblot analysis to determine specific protein concentrations.

Essential oils from Azorean Laurus azorica.

The essential oils isolated from leaves of ten and from unripe berries of eight populations of Laurus azorica (Seub.) Franco, collected on five islands of the Azorean archipelago, were analysed by GC and GC-MS. All oil samples were dominated by their monoterpene fraction (60-94%), alpha-pinene (15-37%) and 1,8-cineole (12-31%) being the main components of the leaf oils, while trans-beta-ocimene (27-45%) and alpha-pinene (12-22%) were the main components of the oils from the berries.

[Study of brain asymmetry with neurologically normal subjects: visual procedures].

Objectives: We present a revision of the technique of visual lateralization of stimuli as one approach to the study of brain asymmetry with regard to language. At the same time, we present a summary of the research carried out by our group using these techniques, reflecting not only the main results but also the most relevant methodological aspects.

Development: Brain asymmetry is a basic characteristic of the organization of the nervous system.

Peroxisomes as a source of reactive oxygen species and nitric oxide signal molecules in plant cells.

The important role of plant peroxisomes in a variety of metabolic reactions such as photorespiration, fatty acid beta-oxidation, the glyoxylate cycle and generation-degradation of hydrogen peroxide is well known. In recent years, the presence of a novel group of enzymes, mainly involved in the metabolism of oxygen free-radicals, has been shown in peroxisomes. In addition to hydrogen peroxide, peroxisomes can generate superoxide-radicals and nitric oxide, which are known cellular messengers with a variety of physiological roles in intra- and inter-cellular communication.

Chemical polymorphism of the essential oils from populations of Thymus caespititius grown on the island S. Jorge (Azores).

The compositions of the essential oils obtained from ten populations of Thymus caespititius grown on S. Jorge (Azores) were studied by GC and GC-MS. All the oils analysed were dominated by their monoterpene fraction (69-9%).

Metasynthesis of qualitative research on living with HIV infection.

Qualitative studies of people living with HIV infection are crucial for providing direction for practice and research because they provide the emic perspective. As more of these qualitative studies are conducted, researchers are challenged to develop ways to synthesize the findings for research and clinical practice. The purpose of the metasynthesis described in this article was to understand the experience of adults living with HIV infection as described in published research.