Attenuation of food allergy symptoms following treatment with human milk oligosaccharides in a mouse model.

BACKGROUND: The prebiotic nature of human milk oligosaccharides (HMOs) and increasing evidence of direct immunomodulatory effects of these sugars suggest that they may have some therapeutic potential in allergy. Here, we assess the effect of two HMOs, 2'-fucosyllactose and 6'-sialyllactose, on symptomatology and immune responses in an ovalbumin-sensitized mouse model of food allergy. METHODS: The effects of oral treatment with 2'-fucosyllactose and 6'-sialyllactose on anaphylactic symptoms induced by oral ovalbumin (OVA) challenge in sensitized mice were investigated. Mast cell functions in response to oral HMO treatment were also measured in the passive cutaneous anaphylaxis model, and direct effects on IgE-mediated degranulation of mast cells were assessed. RESULTS: Daily oral treatment with 2'-fucosyllactose or 6'-sialyllactose attenuated food allergy symptoms including diarrhea and hypothermia. Treatment with HMOs also suppressed antigen-induced increases in mouse mast cell protease-1 in serum and mast cell numbers in the intestine. These effects were associated with increases in the CD4(+) CD25(+) IL-10(+) cell populations in the Peyer's patches and mesenteric lymph nodes, while 6'-sialyllactose also induced increased IL-10 and decreased TNF production in antigen-stimulated splenocytes. Both 2'-fucosyllactose and 6'-sialyllactose reduced the passive cutaneous anaphylaxis response, but only 6'-sialyllactose directly inhibited mast cell degranulation in vitro, at high concentrations. CONCLUSIONS: Our results suggest that 2'-fucosyllactose and 6'-sialyllactose reduce the symptoms of food allergy through induction of IL-10(+) T regulatory cells and indirect stabilization of mast cells. Thus, human milk oligosaccharides may have therapeutic potential in allergic disease.

LPS from bovine serum albumin drives TNF-α release during ex-vivo placenta perfusion experiments, contaminates the perfusion system but can be effectively removed by oxidative cleaning.

INTRODUCTION: The dual ex-vivo perfusion of human placental tissue is useful to study inflammatory pathways. We found significant TNF-α release in negative controls similar in concentration to lipopolysaccharide (LPS) stimulated placentas. The aim of the current study was to (i) identify sources driving TNF-α release and (ii) develop an approach to control for it. METHOD: (i) To determine sources leading to TNF-α release, solutions frequently circulated through the perfusion system and perfusion media with different bovine serum albumin (BSA) quality were exposed to mouse macrophage cell lines (RAW264.7) and subsequently measured for TNF-α expression. (ii) To assess memory effects and validate cleaning procedures, sham perfusion experiments were conducted either in the presence or absence of exogenous LPS, in new tubing that was contaminated, cleaned and analyzed for the effectiveness of LPS removal. Oxidative and acid-base cleaning were tested for their effectiveness to reduce LPS contamination. RESULTS: TNF-α release, observed in negative control experiments, was attributed to the use of LPS-contaminated BSA as well as inadequate cleaning of the perfusion system. Once introduced in the perfusion system, LPS accumulated and created a memory effect. Oxidative but not acid-base depyrogenation effectively reduced LPS levels to concentrations that were in accordance with FDA guidelines (<0.5 EU/mL) for medical equipment redeemed appropriate for re-use. DISCUSSION: LPS contamination of the placenta perfusion model could have confounding effects on experimental outcomes leading to misinterpretation of data. To circumvent LPS contamination LPS-free BSA and oxidative depyrogenation cleaning techniques should be implemented in future placental perfusion studies.

An evaluation of cefaclor in Pakistani children with pharyngotonsillitis.

OBJECTIVE: To assess the efficacy, safety of cefaclor for the treatment of pharyngotonsillitis in Pakistani children. METHOD: Pakistani children between the ages of two to twelve years and diagnosed with pharyngotonsillitis were eligible to participate in the study. Cefaclor was administered three times daily for a total dose of 20-40 mg/kg/day, depending on the severity of the infection, for 7 days. Patients were evaluated on the basis of symptomatic response and antibiotic susceptibility pattern as a result of bacteriological examination. RESULTS: Based on observed pre-therapy signs/symptoms of infection with pharyngotonsillitis, 99% of patients (95% CI=94.9% to 100.0%) were reported as having a symptomatic response of Cure or Improvement by end of study. Group A b-haemolytic Streptococci was the most prevalent pathogen isolated pre-therapy (occurring in 45% of patients). Of all patients for whom this pathogen was isolated, 64% had complete eradication by end of therapy, while there was persistence or superinfection in 36% of patients. Only 9 occurrences of non-serious adverse events were observed among 7 of the 107 patients, including diarrhea (5), nausea (1), vomiting (1), rash (1) and stomatitis (1). CONCLUSION: Based on the high symptomatic response rate of 99% and the positive safety data, cefaclor was found to be effective and safe in treating Pakistani children with pharyngotonsillitis.

Urinary retention following routine neurosurgical spine procedures.

BACKGROUND: The rate and duration of urinary retention after routine cervical and lumbar spine procedures were studied. METHODS: Preoperative, intraoperative, and postoperative factors related to urinary retention (age, sex, duration of operation, medications, Foley use, hospital stay, and cost) were analyzed in a retrospective review of 503 patients' charts. RESULTS: Urinary retention occurred 38% of the time following cervical and lumbar spine procedures. Advanced age and preoperative beta blockers contributed to a higher incidence of urinary retention. Preoperative anti-inflammatory medications and narcotic analgesics reduced the frequency of urinary retention. The duration of urinary retention was prolonged in older patients and patients who underwent intraoperative Foley catheterization. Urinary retention contributed to longer hospitalization and increased hospital costs. CONCLUSIONS: Transient urinary retention is a common complication of routine neurosurgical spine procedures that prolongs hospital stays and increases the costs of hospitalization.

Biosynthesis of exopolysaccharide by Pseudomonas aeruginosa.

In batch cultures of Pseudomonas aeruginosa, the maximum rate of exopolysaccharide synthesis occurred during exponential growth. In nitrogen-limited continuous culture, the specific rate of exopolysaccharide synthesis increased from 0.27 g g of cell-1 h-1 at a dilution rate (D) of 0.05 h-1 to 0.44 g g of cells h-1 at D=0.1 H-1. The yield of exopolysaccharide on the basis of glucose used was in the range of 56 to 64%. Exopolysaccharide was also synthesized in carbon-limited cultures at 0.19 g g of cell-1 h-1 at D=0.05 h-1 in a 33% yield. Nonmucoid variants appeared after seven generations in continuous culture and rapidly increased in proportion to the total number of organisms present.

Studies on mitochondria membrane proteins in Saccharomyces cerevisiae under different degrees of glucose repression.

Mitochondrial membrane proteins synthesized in vivo in the presence of cycloheximide were analyzed on electrofocusing polyacrylamide gels. Five of the six protein bands observed have their isoelectric points below pH 7. The six proteins are not synthesized when both cycloheximide and chloramphenicol are present, and they are absent in a petite mutant lacking mitochondrial deoxyribonucleic acid (DNA), leading to the conclusion that the proteins are synthesized on mitochondrial ribosomes. By labeling cells of Saccharomyces cerevisiae cultivated in a chemostat under different degrees of glucose limitation, the effect of glucose repression on the synthesis of the mitochondrial membrane proteins was determined. Two of the protein bands showed a relatively reduced synthesis under the strongest glucose repression tested. The specific activity of the cytochrome oxidase and the percentage of mitochondrial DNA in the total DNA were found to be influenced at a lower level of glucose repression.

Characterization of insoluble protein fractions of mitochondria from Saccharomyces cerevisiae.

Saccharomyces cerevisiae was grown in a chemostat in the presence of excess oxygen. Cells harvested from fully derepressed and strongly repressed steady states show typical promitochondria-like structures under conditions of strong repression. Insoluble membrane proteins were extracted from highly purified mitochondria and submitted to isoelectric focusing in 6% polyacrylamide gels. Some 20 protein bands were obtained from derepressed cells. The pattern was clearly different (quantitatively and possibly qualitatively) from repressed mitochondria. In contrast to ribosomal proteins, insoluble membrane protein fractions were found in the acid section (pH 4 to 6.8) of the ampholyte gels. It can be concluded that glucose repression plays a prominent role in the synthesis of the functional mitochondrial membranes.