Novel lipopolysaccharide biosynthetic genes containing tetranucleotide repeats in Haemophilus influenzae, identification of a gene for adding O-acetyl groups.

Many of the genes for lipopolysaccharide (LPS) biosynthesis in Haemophilus influenzae are phase variable. The mechanism of this variable expression involves slippage of tetranucleotide repeats located within the reading frame of these genes. Based on this, we hypothesized that tetranucleotide repeat sequences might be used to identify as yet unrecognized LPS biosynthetic genes.

Making electronic mail accessible: perspectives of people with acquired cognitive impairments, caregivers and professionals.

The primary objective of this study was to better understand the technology needs, barriers and strategies of individuals with acquired cognitive impairments (ACI) in order to design and modify technologies with potential for alleviating the diminished independence and social isolation common in this population. The authors hypothesized that (1) higher rates of computer use would be reported by younger, more highly educated individuals with ACI, those with less severe injuries and those with previous computer experience; (2) A low percentage of survey respondents would own their own computers; and (3) People with ACI would experience social isolation and report low frequency of connecting with important people who live far away. A total of 133 individuals with ACI, professionals and care providers completed the survey.

Multifocal visual evoked potentials to cone specific stimuli in patients with retinitis pigmentosa.

Our aim was to determine whether patients with retinitis pigmentosa show differences in L- and M-cone multifocal visual evoked potential (mfVEP) responses that are eccentricity dependent, as has been shown for control subjects. Second, we compared the losses for mfVEPs to losses on achromatic visual field and multifocal electroretinogram (mfERG) measures in the patients. Monocular mfVEPs were recorded to a pattern reversing display that modulated only the L- or M-cones.

Treatment options for traumatic pseudoaneurysms of the paravisceral abdominal aorta.

Penetrating gunshot wounds (GSWs) to the abdominal aorta are frequently lethal. Alternative management options for treatment of traumatic pseudoaneurysms of the abdominal aorta are illustrated by three patient case histories. Patient A sustained two GSWs to the abdomen (midepigastrium, right subcostal region).

Structural investigation of lipopolysaccharides from nontypeable Haemophilus influenzae: investigation of inner-core phosphoethanolamine addition in NTHi strain 981.

LPS of NTHi comprises a conserved tri-l-glycero-D-manno-heptosyl inner-core moiety (l-alpha-D-Hepp-(1-->2)-[PEtn-->6]-l-alpha-D-Hepp-(1-->3)-[beta-D-Glcp-(1-->4)]-l-alpha-D-Hepp-(1-->5)-alpha-Kdop) in which addition of PEtn to the central heptose (HepII) in strain Rd is controlled by the gene lpt6. It was recently shown that NTHi strain 981 contains an additional PEtn linked to O-3 of the terminal heptose of the inner-core moiety (HepIII). In order to establish whether lpt6 is also involved in adding PEtn to HepIII, lpt6 in strain 981 was inactivated.

The pattern electroretinogram in glaucoma patients with confirmed visual field deficits.

Purpose: To better understand the relationship between the amplitude of the pattern electroretinogram (PERG) and visual loss, measured with static automated perimetry.

Methods: Transient PERGs were recorded in 15 patients (31-77 years) and 16 normal individuals (26-65 years). An eye was considered to have glaucomatous damage only if there was an abnormal disc, an abnormal 24-2 Humphrey visual field result (pattern stand deviation, glaucoma hemifield test, and cluster) and an abnormal multifocal visual evoked potential.

Overnight orthokeratology lens wear can inhibit the central stromal edema response.

Purpose: To investigate the overnight corneal edema response during overnight orthokeratology (OK).

Methods: Eighteen young adult myopic subjects wore reverse-geometry lenses in Boston XO material (nominal Dk/t 46 x 10(-9) cm.mL O2/s.

Auto-immune-like cone dystrophy.

Purpose: To describe rapid loss of cone vision in an adult due to putative auto-immune rejection.

Methods: Clinical and electrophysiological examination, including full-field and multi-focal electroretinograms (ERGs), were used to assess retinal function. Serum was analyzed for antibodies to retinal antigens.

Talking about TB: multicultural diversity and tuberculosis services in Waikato, New Zealand.

Aim: To explore the diversity of opinion amongst different refugee and minority group representatives about tuberculosis, and to examine the provision of services and their effectiveness in the Waikato Health District, New Zealand.

Methods: Open-ended qualitative interviews with the representatives of seven minority populations were undertaken. The interviews focused on the cultural differences in the approach of minority populations to health issues and on the accessibility of health services to these population groups.

Differential susceptibility of subsarcolemmal and intermyofibrillar mitochondria to apoptotic stimuli.

Apoptosis can be evoked by reactive oxygen species (ROS)-induced mitochondrial release of the proapoptotic factors cytochrome c and apoptosis-inducing factor (AIF). Because skeletal muscle is composed of two mitochondrial subfractions that reside in distinct subcellular regions, we investigated the apoptotic susceptibility of subsarcolemmal (SS) and intermyofibrillar (IMF) mitochondria. SS and IMF mitochondria exhibited a dose-dependent release of protein in response to H2O2 (0, 25, 50, and 100 microM).

Evaluation of displacement of the digital cushion in response to vertical loading in equine forelimbs.

Objective: To evaluate patterns of digital cushion (DC) displacement that occur in response to vertical loading of the distal portion of the forelimb in horses. Sample Population-Forelimbs from 10 horses with normal feet.

Procedure: Patterns of DC displacement induced by in vitro vertical limb loading were determined.

Determining abnormal latencies of multifocal visual evoked potentials: a monocular analysis.

Purpose: To describe a methodology for measuring abnormal timing of monocular multifocal visual evoked potentials (mfVEP).

Methods: The mfVEPs from 100 individuals with normal visual fields and normal fundus exams were analyzed. The stimulus was a 60 sector, pattern-reversing dartboard display.

Determining abnormal interocular latencies of multifocal visual evoked potentials.

Purpose: To describe methods for measuring interocular latency differences of multifocal visual evoked potentials (mfVEP) and for determining regions with abnormal interocular latencies in patients.

Methods: The mfVEPs from 100 individuals with normal visual fields and normal fundus examinations were analyzed. Individuals ranged in age from 21.

An alternate pattern for globoside oligosaccharide expression in Haemophilus influenzae lipopolysaccharide: structural diversity in nontypeable strain 1124.

Common structural motifs of Haemophilus influenzae lipopolysaccharide (LPS) are globotetraose [beta-d-GalpNAc-(1-->3)-alpha-d-Galp-(1-->4)-beta-d-Galp-(1-->4)-beta-d-Glcp] and its truncated versions globoside [alpha-d-Galp-(1-->4)-beta-d-Galp-(1-->4)-beta-d-Glcp] and lactose [beta-d-Galp-(1-->4)-beta-d-Glcp] linked to the terminal heptose (HepIII) of the triheptosyl inner-core moiety l-alpha-d-Hepp-(1-->2)-[PEA-->6]-l-alpha-d-Hepp-(1-->3)-l-alpha-d-Hepp-(1-->5)-[PPEA-->4]-alpha-Kdo-(2-->6)-lipid A. We report here structural studies of LPS from nontypeable H. influenzae strain 1124 expressing these motifs linked to both the proximal heptose (HepI) and HepIII at the same time.

Elucidation of the monoclonal antibody 5G8-reactive, virulence-associated lipopolysaccharide epitope of Haemophilus influenzae and its role in bacterial resistance to complement-mediated killing.

The phase-variable locus lex2 is required for expression of a Haemophilus influenzae lipopolysaccharide (LPS) epitope of previously unknown structure. This epitope, which is reactive with monoclonal antibody (MAb) 5G8, has been associated with virulence of type b strains. When strain RM118 (from the same source as strain Rd), in which the lex2 locus and MAb 5G8 reactivity are absent, was transformed with lex2 DNA, transformants that were reactive with MAb 5G8 were obtained.

Evaluation of architectural changes along the proximal to distal regions of the dorsal laminar interface in the equine hoof.

Objective: To describe architectural changes along the dorsal laminar interface of the equine foot.

Sample Population: 6 macroscopically normal forefeet obtained from 6 equine cadavers.

Procedure: Histologic sections of 8 evenly spaced, proximal to distal, samples of the dorsal laminar interface were photographed, digitized, and examined for differences in architecture.

Microsatellite instability regulates transcription factor binding and gene expression.

Microsatellites are tandemly repeated simple sequence DNA motifs widely prevalent in eukaryotic and prokaryotic genomes. In pathogenic bacteria, instability of these hypermutable loci through slipped-strand mispairing mediates the high-frequency reversible switching of phenotype expression, i.e.

Interpreting the multifocal visual evoked potential: the effects of refractive errors, cataracts, and fixation errors.

Aim: To understand how refractive errors, cataracts, and fixation errors affect multifocal visual evoked potential (mfVEP) responses.

Methods: Monocular mfVEP responses were obtained using a pattern reversal dartboard display. For the control condition, visual acuity was corrected to > or =20/20 and foveal fixation was maintained.

The multifocal visual evoked potential: an objective measure of visual fields?

We examined the effects of inter-modal attention and mental arithmetic on Humphrey visual field sensitivity and multifocal visual evoked potential (mfVEP) amplitude. Four normally sighted subjects (ages ranging from 24 to 58 years) participated in this study. Monocular visual field sensitivity was measured under two conditions: (1) standard testing condition and (2) while the subject performed a Paced Auditory Serial Addition Task (PASAT).

Normative ranges and specificity of the multifocal VEP.

Purpose: To describe a normative database for the multifocal VEP (mfVEP) and to evaluate specificity for a range of cluster criteria.

Methods: One hundred persons (62 females and 38 males) with normal visual fields and ranging in age from 21.6 to 92.

Inhaled benzo(a)pyrene impairs long-term potentiation in the F1 generation rat dentate gyrus.

The purpose of this study is to provide a point of reference regarding the neurotoxic effects resulting from exposure to environmental contaminants. Benzo(a)pyrene is a member of the polycyclic aromatic hydrocarbon (PAH) family and it is a by-product of combustion processes. Thus, persons living near factories or hazardous waste sites face the danger of exposure through contact with contaminated air, water and soil.

Increasing the sensitivity of the multifocal visual evoked potential (mfVEP) technique: incorporating information from higher order kernels using a principal component analysis method.

Principal component analysis (PCA) was employed to enhance the multifocal visual evoked potential (mfVEP) technique. First, by using four principal components, the separation of mfVEP signals from noises was improved. Second, two otherwise unused higher order kernels, the 2nd slice of the 2nd order kernel and the 4th order kernels, were utilized by combining information obtained from the PCA.