Publications by authors named "Tim Roberts"

Staphylococcus aureus strains are a great contributor to both hospital acquired infections as well as community acquired infections. The objective of the present investigation was to compare potential differences in cytoplasmic amino acid levels between clinical and ATCC 29213 strains of S. aureus.

View Article and Find Full Text PDF

About 30% of patients who have a kidney transplant with underlying nephrotic syndrome (NS) experience rapid relapse of disease in their new graft. This is speculated to be due to a host-derived circulating factor acting on podocytes, the target cells in the kidney, leading to focal segmental glomerulosclerosis (FSGS). Our previous work suggests that podocyte membrane protease receptor 1 (PAR-1) is activated by a circulating factor in relapsing FSGS.

View Article and Find Full Text PDF

The bacterial pathogen causes a wide range of infections that result in high morbidity and mortality rates worldwide. is known for its capacity to survive harsh environments between hosts and certain strains are very efficient as opportunistic pathogens. It is important to understand their capacities for metabolic adaptation in response to changing environmental conditions.

View Article and Find Full Text PDF

This review article addresses the strategic formulation of human probiotics and allows the reader to walk along the journey that metamorphoses commensal microbiota into target-based probiotics. It recapitulates what are probiotics, their history, and the main mechanisms through which probiotics exert beneficial effects on the host. It articulates how a given probiotic preparation could not be all-encompassing and how each probiotic strain has its unique repertoire of functional genes.

View Article and Find Full Text PDF

In response to rapidly changing societal conditions stemming from the COVID-19 pandemic, we summarize data sources with potential to produce timely and spatially granular measures of physical, economic, and social conditions relevant to public health surveillance, and we briefly describe emerging analytic methods to improve small-area estimation. To inform this article, we reviewed published systematic review articles set in the United States from 2015 to 2020 and conducted unstructured interviews with senior content experts in public heath practice, academia, and industry. We identified a modest number of data sources with high potential for generating timely and spatially granular measures of physical, economic, and social determinants of health.

View Article and Find Full Text PDF

The sharp increase in infections due to is associated with its ability to adapt to changes in its habitat. This study aimed to investigate the differences in the cytoplasmic amino acid profiles of a clinical strain of under five combinations of stress-induced conditions representative of a wound site by varying temperature 35-37 °C, adding 0-5% NaCl and adjusting pH 6-8. The results indicated that aspartic acid, lysine, glutamic acid and histidine were the most abundant cytoplasmic amino acids in the control samples grown under optimal growth conditions.

View Article and Find Full Text PDF

is an important pathogen that is associated with nosocomial infections, as well as food poisoning. This bacterium is resistant to antimicrobial agents and can survive in a wide range of environmental conditions. The aim of this study was to measure the uptake and release of amino acids by at mid-exponential and stationary phases of growth following exposure to a combination of conditions including variations in temperature, pH and NaCl.

View Article and Find Full Text PDF

Staphylococcus aureus is a versatile bacterium that can adapt to survive and grow in a wide range of salt concentrations. This study investigated whether the cells could mount a response to survive a challenge of 5% NaCl in a minimal incubation medium that would not support cell replication. Cells were grown in liquid culture, washed and then incubated for 90 min at 37°C in a medium that contained only glycine and glucose as substrates in PBS plus trace elements.

View Article and Find Full Text PDF

Purpose: It is proposed that central femoral ACL graft placement better controls rotational stability. This study evaluates the consequence of changing the femoral tunnel position from the AM position drilled transtibially to the central position drilled transportally. The difference in ACL graft failure is reported.

View Article and Find Full Text PDF

X-ray free-electron lasers in the oscillator configuration (XFELO) are future fully coherent hard X-rays sources with ultrahigh spectral purity. X-ray beams circulate in an XFELO optical cavity comprising diamond single crystals. They function as high-reflectance (close to 100%), narrowband (∼10 meV) Bragg backscattering mirrors.

View Article and Find Full Text PDF

Temperature and pH are known to vary in a wound site due to the immune response and subsequent healing processes. This study used a multifactorial design to examine the cellular responses of to hydrogen peroxide (0-100 mM) when bacteria were grown in temperatures of 37 ± 2 °C and pH 7 ± 1, conditions potentially encountered in wound sites. A centroid sample was included in the design which represented the mid-point values of all three environmental parameters (37 °C, pH 7, 50 mM HO).

View Article and Find Full Text PDF

In this repeated measures case study, we show that sensory deafferentation after limb amputation leads to changes in cortical somatotopic maps which are reversible after restoration of sensory input. Using magnetoencephalography (MEG), we observed in a child with bilateral hand transplants large-scale shifts in somatosensory lip cortical representation from anatomic hand area to anatomic face region. After recovery of tactile sensation in the digits, responses to finger stimulation were localized to orthotopic sensory cortex, but with atypical electrophysiologic features (amplitude and frequencies).

View Article and Find Full Text PDF

Exposure to toxic industrial chemicals such as phosgene may occur through accidental or deliberate release. Inhalation may result in an acute lung injury which manifests as hypoxaemia with insufficient oxygen being delivered to the tissues resulting in hypoxia, respiratory failure and death. No effective pharmacological therapy currently exists and treatment remains supportive, often requiring intensive care facilities.

View Article and Find Full Text PDF

Staphylococcus aureus is an opportunistic pathogen responsible for a high proportion of nosocomial infections. This study was conducted to assess the bacterial responses in the cytoplasmic composition of amino acids and ribosomal proteins under various environmental conditions designed to mimic those on the human skin or within a wound site: pH6-8, temperature 35-37°C, and additional 0-5% NaCl. It was found that each set of environmental conditions elicited substantial adjustments in cytoplasmic levels of glutamic acid, aspartic acid, proline, alanine and glycine (P< 0.

View Article and Find Full Text PDF

Background: In human TKA studies, intraosseous regional administration (IORA) of prophylactic antibiotics achieves local tissue antibiotic concentrations 10 times greater than systemic administration. However, it is unclear if such high concentrations provide more effective prophylaxis.

Questions/purposes: We asked: (1) What prophylaxis dosage and route (intravenous [IV] versus IORA of prophylactic antibiotics) produce less in vivo bacterial burden compared with no-antibiotic controls? (2) Compared with controls, what prophylaxis dosage and route yield fewer colony-forming units (CFUs) in euthanized animals in a model of TKA? (3) Is prophylactic IORA of antibiotics more effective than same-dose IV antibiotic administration in reducing CFUs?

Methods: Mice (six to nine per group) were block randomized to one of six prophylaxis regimens: control, systemic cefazolin (C100IV), IORA of cefazolin (C100IORA), systemic vancomycin (V110IV), low-dose systemic vancomycin (V25IV), and low-dose IORA of vancomycin (V25IORA).

View Article and Find Full Text PDF

Unlabelled: The high pathogenicity of Staphylococcus aureus is thought to be due to its extraordinary capacity to rapidly adapt to changes in environmental conditions. This study was carried out to investigate whether the cytoplasmic profiles of metabolites and proteins of S. aureus were altered in response to prolonged exposure to cold stress.

View Article and Find Full Text PDF

Purpose Of Review: Emerging data in the peer-reviewed literature indicate that femtosecond laser-assisted cataract surgery (LCS) is a well tolerated and effective alternative to conventional phacoemulsification. Initial reports have largely been based on findings from an optimal patient selection. As confidence with the technology has grown, clinical indications have expanded and the benefit of LCS in high-risk patients with complex cataracts is increasingly being considered.

View Article and Find Full Text PDF

Background: A new dietary supplement, Fatigue Reviva™, has been recently developed to address issues related to amino acid depletion following illness or in conditions of sub-health where altered amino acid homeostasis has been associated with fatigue. Complex formulations of amino acids present significant challenges due to solubility and taste constraints. This initial study sets out to provide an initial appraisal of product palatability and to gather pilot evidence for efficacy.

View Article and Find Full Text PDF

The aims of this study were to: (1) determine whether replacement of cow's milk protein with soy resolves Chronic Functional Constipation (CFC); and (2) investigate the effects of cow's milk β casein A1 and cow's milk β casein A2 on CFC. Children diagnosed with CFC were recruited to one of two crossover trials: Trial 1 compared the effects of cow's milk and soy milk; Trial 2 compared the effects of cow's milk β casein A1 and cow's milk β casein A2. Resolution of constipation was defined as greater than eight bowel motions during a two week intervention.

View Article and Find Full Text PDF

Objectives: To examine altered amino acid homeostasis as a predisposing factor of fatigue in female radiotherapy breast cancer patients.

Design And Methods: Participants underwent breast-conserving surgery and adjuvant breast irradiation and were free from significant fatigue pre-radiotherapy. The Functional Assessment of Cancer Therapy fatigue subscale was used to assess fatigue pre- and post-radiotherapy.

View Article and Find Full Text PDF

Peroxisome proliferator-activated receptor-gamma (PPAR-gamma) agonists have been shown to protect the cerebral vasculature, including the blood-brain barrier. In the present study, we investigated the effect of the PPAR-gamma agonist rosiglitazone on changes in venous permeability during chronic hypertension induced by nitric oxide synthase inhibition. Female Sprague-Dawley rats were either treated with N(G)-nitro-L-arginine methyl ester (L-NAME; 0.

View Article and Find Full Text PDF

Autism is a complex and life-long behavioural disorder of unknown aetiology. Recent reports have indicated the involvement of digestive tract dysfunction and possible complications from inadequate nutrition. In this study, 34 autistic children (12 untreated and 22 receiving therapeutic treatments related to digestive function and nutritional uptake) and 29 control subjects (all 5-15 years of age) were investigated to determine whether there were any anomalies in the urinary excretion of amino acids, glucose, sucrose, arabinose and tartaric acid using GC/FID and GC/MS analysis techniques.

View Article and Find Full Text PDF

Unlabelled: Abstract.

Background: In the clinical management of patients at risk for or diagnosed with primary open-angle glaucoma (POAG), the aim of medical treatment is to reduce intraocular pressure (IOP) and then maintain it over time at a level that preserves both the structure and function of the optic nerve.

Objective: The objective of this report was to establish a consensus on the criteria that should be used to determine the characteristics of IOP-lowering medication.

View Article and Find Full Text PDF

Severe hypertriglyceridemia is a rare condition in pregnancy. All the cases of severe gestational hypertriglyceridemia that have been reported previously in the literature were caused by genetic mutations or familial hypertriglyceridemia secondary to lipoprotein lipase deficiency or apolipoprotein C-II deficiency. We report the first case of severe, non-genetic, non-familial, pregnancy-induced hypertriglyceridemia.

View Article and Find Full Text PDF

A PHP Error was encountered

Severity: Warning

Message: fopen(/var/lib/php/sessions/ci_sessionhqge8d89v43de9175s15vv4gob23ncl6): Failed to open stream: No space left on device

Filename: drivers/Session_files_driver.php

Line Number: 177

Backtrace:

File: /var/www/html/index.php
Line: 316
Function: require_once

A PHP Error was encountered

Severity: Warning

Message: session_start(): Failed to read session data: user (path: /var/lib/php/sessions)

Filename: Session/Session.php

Line Number: 137

Backtrace:

File: /var/www/html/index.php
Line: 316
Function: require_once