Trp(359) regulates flavin thermodynamics and coenzyme selectivity in Mycobacterium tuberculosis FprA.

Mtb (Mycobacterium tuberculosis) FprA (flavoprotein reductase A) is an NAD(P)H-dependent FAD-binding reductase that is structurally related to mammalian adrenodoxin reductase, and which supports the catalytic function of Mtb cytochrome P450s. Trp(359), proximal to the FAD, was investigated in light of its potential role in controlling coenzyme interactions, as observed for similarly located aromatic residues in diflavin reductases. Phylogenetic analysis indicated that a tryptophan residue corresponding to Trp(359) is conserved across FprA-type enzymes and in adrenodoxin reductases.

Potato peels as solid waste for the removal of heavy metal copper(II) from waste water/industrial effluent.

A new sorbent potato peels, which are normally discarded as solid waste for removing toxic metal ion Cu(II) from water/industrial waste water have been studied. Potato peels charcoal (PPC) was investigated as an adsorbent of Cu(II) from aqueous solutions. Kinetic and isotherm studies were carried out by studying the effects of various parameters such as temperature, pH and solid liquid ratios.

Contribution of the SitABCD, MntH, and FeoB metal transporters to the virulence of avian pathogenic Escherichia coli O78 strain chi7122.

The roles of SitABCD, MntH, and FeoB metal transporters in the virulence of avian pathogenic Escherichia coli (APEC) O78 strain chi7122 were assessed using isogenic mutants in chicken infection models. In a single-strain infection model, compared to chi7122, the Deltasit strain demonstrated reduced colonization of the lungs, liver, and spleen. Complementation of the Deltasit strain restored virulence.

Attentional and linguistic interactions in speech perception.

The role of attention in speech comprehension is not well understood. We used fMRI to study the neural correlates of auditory word, pseudoword, and nonspeech (spectrally rotated speech) perception during a bimodal (auditory, visual) selective attention task. In three conditions, Attend Auditory (ignore visual), Ignore Auditory (attend visual), and Visual (no auditory stimulation), 28 subjects performed a one-back matching task in the assigned attended modality.

The thickness of the intimal and medial layers of the carotid arteries, and the index of left ventricular mass, in children of patients with premature coronary arterial disease.

Objective: To compare the thickness of the intimal and medial layers of the carotid arteries, and the index of left ventricular mass, in children of parents suffering premature myocardial infarction, and to compare the findings with suitable controls.

Methods: Our population comprised 112 healthy adolescents, aged from 12 to 18 years, with a parental history of onset of coronary arterial disease under 55 years of age. We compared this cohort with 127 adolescents matched for age and gender, but without any history of coronary arterial disease in their first and second relatives.

Axonopathy-inducing 1,2-diacetylbenzene forms adducts with motor and cytoskeletal proteins required for axonal transport.

The aromatic hydrocarbon 1,2-diacetylbenzene (1,2-DAB) is a protein-reactive gamma-diketone metabolite of the neurotoxic solvent 1,2-diethylbenzene (1,2-DEB). The effect of neurotoxic 1,2-DAB and its non-neurotoxic isomer 1,3-DAB has been studied on motor proteins and cytoskeletal proteins of rat spinal cord (SC). For in vitro studies, SC slices were incubated with 1, 2, 5, 10 mM of DAB isomers for 30 min at 37 degrees C.

Rapid P450 heme iron reduction by laser photoexcitation of Mycobacterium tuberculosis CYP121 and CYP51B1. Analysis of CO complexation reactions and reversibility of the P450/P420 equilibrium.

We demonstrate that photoexcitation of NAD(P)H reduces heme iron of Mycobacterium tuberculosis P450s CYP121 and CYP51B1 on the microsecond time scale. Rates of formation for the ferrous-carbonmonoxy (Fe(II)-CO) complex were determined across a range of coenzyme/CO concentrations. CYP121 reaction transients were biphasic.

Sultam thiourea inhibition of West Nile virus.

We have identified sultam thioureas as novel inhibitors of West Nile virus (WNV) replication. One such compound inhibited WNV, with a 50% effective concentration of 0.7 microM, and reduced reporter expression from cells that harbored a WNV-based replicon.

Oral sildenafil to control pulmonary hypertension after congenital heart surgery.

This study investigates the role of oral sildenafil in decreasing pulmonary pressure after congenital heart surgery. Between September 2002 and September 2004, among a group of postoperative children with large septal defects, moderate to severe pulmonary hypertension [pulmonary artery (PA) to aortic (Ao) pressure ratio of 0.76 +/- 0.

Protective effect following intranasal exposure of goats to live Pasteurella multocida B:2.

This study aimed to determine the effect of intranasal exposure to low doses of Pasteurella multocida B:2 on survival of goats challenged with high doses of the same organism. Eighteen goats were selected and divided into three groups. Goats of group 1 were exposed intranasally twice, with a two-week interval, to 7 x 10(6) cfu/ml of live P.

Morphometric histology for infant gastroesophageal reflux disease: evaluation of reliability in 497 esophageal biopsies.

Objectives: We sought to determine the reliability of morphometric measurements on infant esophageal biopsies using a light microscope with eyepiece micrometer.

Methods: We measured epithelial thickness, basal layer thickness (B), papillary height (P) and epithelial lymphocyte and eosinophil numbers on approximately 500 existing esophageal suction biopsies from infants previously evaluated for reflux esophagitis. We tested these measurements for interobserver, test-retest and internal consistency reliability.

Involvement of the left anterior insula and frontopolar gyrus in odor discrimination.

Discriminating between successively presented odors requires brief storage of the first odor's perceptual trace, which then needs to be subsequently compared to the second odor in the pair. This study explores the cortical areas involved in odor discrimination and compares them with findings from studies of working-memory, traditionally investigated with n-back paradigms. Sixteen right-handed subjects underwent H(2) (15)O positron emission tomography during counterbalanced conditions of odorless sniffing, repeated single odor detection, multiple odor detection, and conscious successive discrimination between odor pairs.

CYP121, CYP51 and associated redox systems in Mycobacterium tuberculosis: towards deconvoluting enzymology of P450 systems in a human pathogen.

An extraordinary array of P450 (cytochrome P450) enzymes are encoded on the genome of the human pathogen Mycobacterium tuberculosis (Mtb) and in related mycobacteria and actinobacteria. These include the first characterized sterol 14alpha-demethylase P450 (CYP51), a known target for azole and triazole drugs in yeasts and fungi. To date, only two Mtb P450s have been characterized in detail: CYP51 and CYP121.

Usefulness of the head-up tilt test in distinguishing neurally mediated syncope and epilepsy in children aged 5-20 years old.

Many nonepileptic disorders may mimic epilepsy by history or clinical presentation. Neurally mediated syncope is one of the most important conditions that might be difficult to differentiate from epilepsy on clinical grounds. We investigated the value of the head-up tilt test (HUT) to diagnose syncope in epileptic children.

Monocyclic and dicyclic hydrocarbons: structural requirements for proximal giant axonopathy.

The chromogenic and neurotoxic gamma-diketone 1,2-diacetylbenzene (1,2-DAB), but not its isomer 1,3-DAB, induces blue discoloration of tissues and urine, clustering of axonal microtubules and proximal neurofilament-filled axonal swellings in rodents. The remarkable chromogenic property of 1,2-DAB, a monocyclic aromatic hydrocarbon, arises from reaction with lysine residues of proteins and formation of dimeric and polymeric derivatives. Tetralin, a dicyclic solvent structurally related to acetyl ethyl tetramethyl tetralin, a chromogenic and neurotoxic agent, reportedly induces excretion of green urine, and causes neurological disturbances in humans.

Attentional modulation in the detection of irrelevant deviance: a simultaneous ERP/fMRI study.

Little is known about the neural mechanisms that control attentional modulation of deviance detection in the auditory modality. In this study, we manipulated the difficulty of a primary task to test the relation between task difficulty and the detection of infrequent, task-irrelevant deviant (D) tones (1,300 Hz) presented among repetitive standard (S) tones (1,000 Hz). Simultaneous functional magnetic resonance imaging (fMRI)/event-related potentials (ERPs) were recorded from 21 subjects performing a two-alternative forced-choice duration discrimination task (short and long tones of equal probability).

Iha from an Escherichia coli urinary tract infection outbreak clonal group A strain is expressed in vivo in the mouse urinary tract and functions as a catecholate siderophore receptor.

Virulence factors of pathogenic Escherichia coli belonging to a recently emerged and disseminated clonal group associated with urinary tract infection (UTI), provisionally designated clonal group A (CGA), have not been experimentally investigated. We used a mouse model of ascending UTI with CGA member strain UCB34 in order to identify genes of CGA that contribute to UTI. iha was identified to be expressed by strain UCB34 in the mouse kidney using selective capture of transcribed sequences.

The preponderance of P450s in the Mycobacterium tuberculosis genome.

The genome of Mycobacterium tuberculosis (Mtb) encodes 20 different cytochrome P450 enzymes (P450s). P450s are mono-oxygenases, which are historically considered to facilitate prokaryotic usage of unusual carbon sources. However, their preponderance in Mtb strongly indicates crucial physiological functions, as does the fact that polycyclic azoles (known P450 inhibitors) have potent anti-mycobacterial effects.

A SitABCD homologue from an avian pathogenic Escherichia coli strain mediates transport of iron and manganese and resistance to hydrogen peroxide.

An operon encoding a member of the family of ATP-binding cassette (ABC) divalent metal ion transporters, homologous to Salmonella enterica SitABCD, has been identified in the avian pathogenic Escherichia coli (APEC) strain chi7122. The sitABCD genes were located on the virulence plasmid pAPEC-1, and were highly similar at the nucleotide level to the chromosomally encoded sitABCD genes present in Shigella spp. A cloned copy of sitABCD conferred increased growth upon a siderophore-deficient E.

Biodiversity of cytochrome P450 redox systems.

P450s (cytochrome P450 mono-oxygenases) are a superfamily of haem-containing mono-oxygenase enzymes that participate in a wide range of biochemical pathways in different organisms from all of the domains of life. To facilitate their activity, P450s require sequential delivery of two electrons passed from one or more redox partner enzymes. Although the P450 enzymes themselves show remarkable similarity in overall structure, it is increasingly apparent that there is enormous diversity in the redox partner systems that drive the P450 enzymes.

Is the failure to detect stimulus deviance during sleep due to a rapid fading of sensory memory or a degradation of stimulus encoding?

The mismatch negativity (MMN) is thought to reflect the outcome of a system responsible for the detection of change in an otherwise repetitive, homogenous acoustic environment. This process depends on the storage and maintenance of a sensory representation of the frequently presented stimulus to which the deviant stimulus is compared. Few studies have been able to record the MMN in non-rapid eye movement (NREM) sleep.

Neural correlates of olfactory change detection.

Detecting changes in a stream of sensory information is vital to animals and humans. While there have been several studies of automatic change detection in various sensory modalities, olfactory change detection is largely unstudied. We investigated brain regions responsive to both passive and active detection of olfactory change using fMRI.

A new murine model of giant proximal axonopathy.

The aromatic gamma-diketone 1,2-diacetylbenzene (1,2-DAB), the putative active metabolite of the organic solvent 1,2-diethylbenzene, forms blue-colored polymeric protein adducts and induces the formation of amyotrophic lateral sclerosis (ALS)-like giant, intraspinal neurofilamentous axonal swellings in Sprague Dawley rats. The pathogenetic mechanism of this neuropathy has yet to be understood. We assessed whether these pathological changes are also seen in the C57BL/6 mouse, the animal of choice for toxicogenomic studies.

Development of a nanoparticle-labeled microfluidic immunoassay for detection of pathogenic microorganisms.

The light-scattering properties of submicroscopic metal particles ranging from 40 to 120 nm in diameter have recently been investigated. These particles scatter incident white light to generate monochromatic light, which can be seen either by the naked eye or by dark-field microscopy. The nanoparticles are well suited for detection in microchannel-based immunoassays.

Pediatric gastric and duodenal disorders.

Purpose Of Review: This review provides a summary of new developments regarding common diseases affecting the stomach and duodenum in children.

Recent Findings: Celiac disease seems to be more prevalent than previously thought in different areas of the world, including the United States. The value of different serologic screening tools and other noninvasive tests has been carefully assessed.