Commercial peptidoglycan preparations are contaminated with superantigen-like activity that stimulates IL-17 production

The immunomodulatory properties of peptidoglycan (PGN), a constituent of the bacterial cell wall, have been studied extensively but with contrasting results. Recent studies have demonstrated that the TLR2-mediated inflammatory responses elicited by Gram-positive PGN preparations are in fact a result of contaminating lipoproteins and lipoteichoic acid that can be removed only through sophisticated extraction procedures. Here, we report that commercial preparations of Staphylococcus aureus or Streptococcus pyogenes PGN are contaminated with bacterial superantigens (SAg). The T cell-derived cytokines IL-17A and IL-17F were induced by PGN preparations but not by TLR agonists or nucleotide-binding and oligomerization domain-like receptor agonists in human PBMC. IL-17 induction by PGN preparations was sensitive to protease digestion and required TCR signaling. Bacterial SAg could be detected by immunoblot in the PGN preparations, and purified recombinant SAg were powerful inducers of IL-17. Finally, the PGN preparations stimulated proliferation and expansion of T cells bearing specific TCR V beta elements. Our results suggest that a large body of literature that relied on commercial PGN preparations to study inflammatory diseases, such as arthritis, where IL-17 also plays an important role, should be interpreted with caution and possibly revisited. Future studies aimed at characterizing the activities of PGN should use PGN preparations of proven purity.     

Multifacility Outbreak of Middle East Respiratory Syndrome in Taif,Saudi Arabia

Middle East respiratory syndrome (MERS) coronavirus (MERS-CoV) is a novel respiratory pathogen first reported in 2012. During September 2014–January 2015, an outbreak of 38 cases of MERS was reported from 4 healthcare facilities in Taif, Saudi Arabia; 21 of the 38 case-patients died. Clinical and public health records showed that 13 patients were healthcare personnel (HCP). Fifteen patients, including 4 HCP, were associated with 1 dialysis unit. Three additional HCP in this dialysis unit had serologic evidence of MERS-CoV infection. Viral RNA was amplified from acute-phase serum specimens of 15 patients, and full spike gene-coding sequencing was obtained from 10 patients who formed a discrete cluster; sequences from specimens of 9 patients were closely related. Similar gene sequences among patients unlinked by time or location suggest unrecognized viral transmission. Circulation persisted in multiple healthcare settings over an extended period, underscoring the importance of strengthening MERS-CoV surveillance and infection-control practices.     

Locally advanced rectal cancer with a pelvic kidney complicating adjuvant radiation therapy

The simultaneous occurrence of colorectal malignancy with pelvic kidney is unusual. We report a case of locally advanced rectal cancer stage III disease, T3N2M0, with a pelvic kidney complicating adjuvant radiation therapy. We recommend preoperative evaluation of the pelvic kidney to allow for its protection by translocation or heterotopic autologous transplantation. Occasionally a nephrectomy may be necessary. Otherwise extended lymph node dissection is not performed; hence, adequate treatment of the primary rectal cancer is compromised. The sequela of inadequate surgical excision and suboptimal radiation therapy is early relapse. © 1996 Wiley-Liss, Inc.     

Yield of endoscopic ultrasound-guided fine needle aspiration and endoscopic retrograde cholangiopancreatography for solid pancreatic neoplasms

Objective: Both endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) and endoscopic retrograde cholangiopancreatography (ERCP) cytology may provide tissue diagnoses in solid pancreatic neoplasms. However, there are scant data comparing these two methods. This study aims at retrospectively comparing EUS-FNA and ERCP tissue sampling and ability of cytopathological diagnosis in solid pancreatic neoplasms and to determine usefulness and adverse events of combining both procedures. Material and methods: Two hundred and thirty four patients suspected to have solid pancreatic mass on abdominal ultrasound and/or computed tomography (CT) were enrolled. EUS-FNA (group A), ERCP cytology (group B) and combined procedures (Group C) performed in 105, 91 and 38 cases, respectively. Results: Sensitivity, specificity and accuracy were 98.9%, 93.3% and 98.1% for group A, and 72.1%, 60% and 71.4% for group B. Those for group C were all 100%. Sensitivity for malignancy in the pancreas head was 100% for group A and 82.4% for group B, and in the pancreas body and tail, 97.6% for group A and 57.1% for group B. EUS-FNA was more sensitive than ERCP cytology in diagnosing malignant pancreatic neoplasms 21–30?mm in size (p?=?0.0068), 31–40?mm (p?=?0.028) and?≥41?mm (p?Conclusions: EUS-FNA is superior to ERCP cytology for diagnosis of solid pancreatic neoplasms. Although combination of both procedures provide efficient tissue diagnosis and with a minimal adverse events rate, a prospective study including larger number of patients is required.     

Probiotics and colostrum/milk differentially affect neonatal humoral immune responses to oral rotavirus vaccine

Breast milk (colostrum [col]/milk) components and gut commensals play important roles in neonatal immune maturation, establishment of gut homeostasis and immune responses to enteric pathogens and oral vaccines. We investigated the impact of colonization by probiotics, Lactobacillus rhamnosus GG (LGG) and Bifidobacterium lactis Bb12 (Bb12) with/without col/milk (mimicking breast/formula fed infants) on B lymphocyte responses to an attenuated (Att) human rotavirus (HRV) Wa strain vaccine in a neonatal gnotobiotic pig model. Col/milk did not affect probiotic colonization in AttHRV vaccinated pigs. However, unvaccinated pigs fed col/milk shed higher numbers of probiotic bacteria in feces than non-col/milk fed colonized controls. In AttHRV vaccinated pigs, col/milk feeding with probiotic treatment resulted in higher mean serum IgA HRV antibody titers and intestinal IgA antibody secreting cell (ASC) numbers compared to col/milk fed, non-colonized vaccinated pigs. In vaccinated pigs without col/milk, probiotic colonization did not affect IgA HRV antibody titers, but serum IgG HRV antibody titers and gut IgG ASC numbers were lower, suggesting that certain probiotics differentially impact HRV vaccine responses. Our findings suggest that col/milk components (soluble mediators) affect initial probiotic colonization, and together, they modulate neonatal antibody responses to oral AttHRV vaccine in complex ways.     

Behavior of mouse spermatogonial stem-like cells on an electrospun nanofibrillar matrix

Purpose

Spermatogonial stem cells are affected by the interactions of extrinsic signals produced by components of the microenvironment niche, in addition to the chemical and physical properties of the extracellular matrix. Therefore, this study was initiated to assess the interaction of these cells on a synthetic nanofibrillar extracellular matrix that mimicked the geometry and nanotopography of the basement membrane for cellular growth.

Methods

This study has used a variety of experimental approaches to investigate the interaction of mouse neonatal-derived spermatogonial stem-like cells on a synthetic random oriented three-dimensional nanofibrillar matrix composed of electrospun polyamide nanofibers (Ultra-Web™).

Results

Spermatogonial stem-like cell colonies were characterized by their ability to express α6-integrin, Thy-1, PLZF, and β1-integrin. After culture of cells on the nanofibrillar surfaces for 7 days, the number of colonies, the number of cells in each colony, and the average area of colonies were increased (P < 0.05). However, the expression difference of related markers in both groups was not significant. A significantly higher proliferation and survival was observed in the nanofibrillar group (P < 0.05). After transplantation into the testes of busulfan-treated adult mice, spermatogonial stem-like cell colonies that were cultured on the nanofibrillar surface demonstrated functionality, as verified by their ability to migrate to the seminiferous basal membrane, where they produced additional colonies.

Conclusions

These results have suggested that electrospun nanofibrillar surfaces could provide a more favorable microenvironment for in vitro short term culture of spermatogonial stem-like cell colonies.