Glutamine as a modulator of the immune system of critical care patients:effect on Toll-like receptor expression. A preliminary study

We evaluated the expression of Toll-like receptors 2 and 4 (TLR-2 and TLR-4) in circulating monocytes from peripheral blood of critical care patients treated with and without glutamine. Because no research has been published to date on the effect of glutamine on TLR receptors in critical patients, it was determined in an initial sample of 30 patients.

Mycobacterium chelonae keratitis:Resolution after debridement and presoaked collagen shields

We report a case of Mycobacterium chelonae keratitis following corneal injury by a foreign body. Diagnosis was made by Ziehl-Neelsen staining and Lowenstein-Jensen culture of corneal scrapings. On the basis of the in vitro susceptibility testing, the patient was treated with topical fortified amikacin. Given the lack of response to this therapy, we decided to carry out a debridement of the infiltrative areas to eliminate infected tissue, and to use an amikacin-soaked collagen shield supplemented every 4 h with topical fortified amikacin to promote healing of the debrided area and to potentiate the effects of the antibiotic therapy. After this treatment, clinical resolution was observed and a further acid-fast stain and culture for mycobacterium were negative. Debridement of the infiltrative areas could be used in cases of mycobacterium keratitis when early diagnosis is made and before the corneal infection has become widespread.

Primary irsi stromal cyst:A report of 17 cases

Objective: To describe clinical characteristics, management, and complications of primary iris stromal cysts. Design: A retrospective review. Results: Seventeen consecutive patients with primary iris stromal cysts were found. Nine (52%) patients were diagnosed under age 10 years (range, 1 day-7 years), and eight (47%) patients were diagnosed after age 10 years (range, 14-71 years). Overall, the cyst appeared unilaterally as a solitary clear translucent mass dissecting the iris stroma in all cases. The children with a primary iris stromal cyst demonstrated a more aggressive course than teenagers or adults. In children, the cyst obstructed the visual axis in eight cases (88%), requiring treatment such as aspiration, cryotherapy, and resection. In seven children, multiple treatments were necessary. Ultimate control of the cyst was achieved in all cases using techniques of needle aspiration (with or without cryotherapy) in three cases and using resection in five cases. Primary iris stromal cysts in teenagers and adults necessitated intervention in only two cases (25%). Conclusion: Primary iris stromal cysts can occur in children, teenagers, and adults. In children, primary stromal iris cysts appear to have a more aggressive clinical course, often requiring several treatments for globe and vision preservation.

Local and systemic immune responses in mice to intranasal delivery of peptides representing bovine respiratory syncytial virus epitopes encapsulated in poly (dl-lactide-co-glycolide) microparticles

The potential of a microparticulate vaccine delivery system in eliciting a specific mucosal antibody response in the respiratory tract of mice was evaluated. Two vaccine candidate peptides representing epitopes from the G attachment and F fusion antigens from bovine respiratory syncytial virus (BRSV) were encapsulated into poly(dl- lactide co-glycolide) biodegradable microparticles. The encapsulation process did not denature the entrapped peptides as verified by detection of peptide-specific antibodies in mucosal secretions by ELISA using peptide as antigen. Following intranasal immunisation, the encapsulated peptides induced stronger upper and lower respiratory tract specific-IgA responses, respectively, than the soluble peptide forms. Moreover, a strong peptide-specific cell-mediated immune response was measured in splenocytes in vitro from the mice inoculated with the encapsulated peptides compared to their soluble form alone indicating that migration of primed T cells had taken place from the site of mucosal stimulation in the upper respiratory tract to the spleen. These results act as a foundation for vaccine efficacy studies in large animal BRSV challenge models.

Non-Acanthamoeba amebic keratitis

Purpose. To describe the clinical presentation and outcome of two cases with presumed non-Acanthamoeba amebic keratitis. Methods. Case reports. Results. Both patients presented with typical symptoms and signs of Acanthamoeba keratitis. The patients' soft contact lenses, lens cases, open solutions, and conjunctival samples were cultured. Diagnosis of non- Acanthamoeba amebic keratitis was based on the presence of keratitis and amebic growth from patients' contact lenses of the affected eyes. Amebic culture from the contralateral contact lens was negative. Vahlkampfia cysts were identified in case 1, and Naegleria cysts in case 2. Topical treatment with polyhexamethylene biguanide and propamidine resolved the keratitis in case 1. Case 2 was lost to follow-up. Conclusion. Non-Acanthamoeba amebic keratitis was diagnosed in two patients based on the clinical presentation (resembling Acanthamoeba keratitis), culture of the contact lens, and response to antiamebic treatment (in one case). Keratitis associated with Naegleria contamination of contact lenses has not been previously reported.

Infectious keratitis in a paracentesis tract

A paracentesis is performed in glaucoma procedures as a flat, beveled tract to allow access into the anterior chamber after the filtration fistula is made. Complications related to the paracentesis are infrequent because it is a self-sealing wound. The authors report a case of infectious keratitis that developed in a paracentesis tract.

Corneal Allograft Rejection:Risk Factors, Diagnosis, Prevention, and Treatment

Recent advances in corneal graft technology, including donor tissue retrieval, storage and surgical techniques, have greatly improved the clinical outcome of corneal grafts. Despite these advances, immune mediated corneal graft rejection remains the single most important cause of corneal graft failure. Several host factors have been identified as conferring a "high risk" status to the host. These include: more than two quadrant vascularisation, with associated lymphatics, which augment the afferent and efferent arc of the immune response; herpes simplex keratitis; uveitis; silicone oil keratopathy; previous failed (rejected) grafts; "hot eyes"; young recipient age; and multiple surgical procedures at the time of grafting. Large grafts, by virtue of being closer to the host limbus, with its complement of vessels and antigen-presenting Langerhans cells, also are more susceptible to rejection. The diagnosis of graft rejection is entirely clinical and in its early stages the clinical signs could be subtle. Graft rejection is largely mediated by the major histocompatibility antigens, minor antigens and perhaps blood group ABO antigens and some cornea-specific antigens. Just as rejection is mediated by active immune mediated events, the lack of rejection (tolerance) is also sustained by active immune regulatory mechanisms. The anterior chamber associated immune deviation (ACAID) and probably, conjunctiva associated lymphoid tissue (CALT) induced mucosal tolerance, besides others, play an important role. Although graft rejection can lead to graft failure, most rejections can be readily controlled if appropriate management is commenced at the proper time. Topical steroids are the mainstay of graft rejection management. In the high-risk situations however, systemic steroids, and other immunosuppressive drugs such as cyclosporin and tacrolimus (FK506) are of proven benefit, both for treatment and prevention of rejection.

High concentrations of AGE-LDL and oxidized LDL in circulating immune complexes are associated with progression of retinopathy in type 1 diabetes

To determine whether immunocomplexes (ICs) containing advanced glycation end product (AGE)-LDL (AGE-LDL) and oxidized LDL (oxLDL) contribute to the development of retinopathy over a 16-year period in subjects with type 1 diabetes.

LDL-containing immune complexes in the DCCT/EDIC cohort:associations with lipoprotein subclasses

Immune complexes containing modified LDL (LDL-IC) and NMR-determined Total LDL particle concentrations are significantly associated with intima-media thickness (IMT). We analyzed the associations between concentrations of NMR-determined lipoprotein subclasses and LDL-IC in the DCCT/EDIC cohort. LDL-IC concentrations in women and men of the DCCT/EDIC cohort did not differ significantly and were positively associated with Total LDL particle concentrations in men and women (r=0.34, r=0.32, respectively; P

Immune complexes containing modified lipoproteins are related to the progression of internal carotid intima-media thickness in patients with type 1 diabetes

Modified lipoproteins induce autoimmune responses including the synthesis of autoantibodies with pro-inflammatory characteristics. Circulating modified lipoprotein autoantibodies combine with circulating antigens and form immune complexes (IC). We now report the results of a study investigating the role of circulating IC containing modified lipoproteins in the progression of carotid intima-media thickness (IMT) in patients enrolled in the Epidemiology of Diabetes Interventions and Complications (EDIC) Trial, a follow-up study of the Diabetes Control and Complications Trial (DCCT). This cohort includes 1229 patients with type 1 diabetes in whom B-mode ultrasonography of internal and common carotid arteries was performed in 1994-1996 and in 1998-2000. Conventional CHD risk factors, antibodies against modified forms of LDL and modified lipoprotein IC were determined in 1050 of these patients from blood collected in 1996-1998. Cholesterol and apolipoprotein B content of IC (surrogate markers of modified ApoB-rich lipoproteins) were significantly higher in patients who showed progression of the internal carotid IMT than in those showing no progression, regression or mild progression. Multivariate linear and logistic regression modeling using conventional and non-conventional risk factors showed that the cholesterol content of IC was a significant positive predictor of internal carotid IMT progression. In conclusion these data demonstrate that increased levels of modified ApoB-rich IC are associated with increased progression of internal carotid IMT in the DCCT/EDIC cohort of type 1 diabetes.

AKT in Stromal Fibroblasts Controls Invasion of Epithelial Cells

The tumour microenvironment has an important role in cancer progression and recent reports have proposed that stromal AKT is activated and regulates tumourigenesis and invasion. We have shown, by immuno-fluorescent analysis of oro-pharyngeal cancer biopsies, an increase in AKT activity in tumour associated stromal fibroblasts compared to normal stromal fibroblasts. Using organotypic raft co-cultures, we show that activation of stromal AKT can induce the invasion of keratinocytes expressing the HPV type 16 E6 and E7 proteins, in a Keratinocyte Growth Factor (KGF) dependent manner. By depleting stromal fibroblasts of each of the three AKT isoforms independently, or through using isoform specific inhibitors, we determined that stromal AKT2 is an essential regulator of invasion and show in oro-pharyngeal cancers that AKT2 specific phosphorylation events are also identified in stromal fibroblasts. Depletion of stromal AKT2 inhibits epithelial invasion through activating a protective pathway counteracting KGF mediated invasions. AKT2 depletion in fibroblasts stimulates the cleavage and release of IL1B from stromal fibroblasts resulting in down-regulation of the KGF receptor (fibroblast growth factor receptor 2B (FGFR2B)) expression in the epithelium. We also show that high IL1B is associated with increased overall survival in a cohort of patients with oro-pharyngeal cancers. Our findings demonstrate the importance of stromal derived growth factors and cytokines in regulating the process of tumour cell invasion.

Cathelicidin-like Helminth Defence Molecules (HDMs):Absence of Cytotoxic, Anti-microbial and Anti-protozoan Activities Imply a Specific Adaptation to Immune Modulation

Host defence peptides (HDPs) are expressed throughout the animal and plant kingdoms. They have multifunctional roles in the defence against infectious agents of mammals, possessing both bactericidal and immune-modulatory activities. We have identified a novel family of molecules secreted by helminth parasites (helminth defence molecules; HDMs) that exhibit similar structural and biochemical characteristics to the HDPs. Here, we have analyzed the functional activities of four HDMs derived from Schistosoma mansoni and Fasciola hepatica and compared them to human, mouse, bovine and sheep HDPs. Unlike the mammalian HDPs the helminth-derived HDMs show no antimicrobial activity and are non-cytotoxic to mammalian cells (macrophages and red blood cells). However, both the mammalian- and helminth-derived peptides suppress the activation of macrophages by microbial stimuli and alter the response of B cells to cytokine stimulation. Therefore, we hypothesise that HDMs represent a novel family of HDPs that evolved to regulate the immune responses of their mammalian hosts by retaining potent immune modulatory properties without causing deleterious cytotoxic effects.