Investigating the filled gel model in Cheddar cheese through use of Sephadex beads.

Cheese can be modeled as a filled gel whereby milkfat globules are dispersed in a casein gel network. We determined the filler effects using Sephadex beads (GE Healthcare Life Sciences, Pittsburgh, PA) as a model filler particle. Ideally, such a model could be used to test novel filler particles to replace milkfat in low-fat cheese. Low-filler (6% particles), reduced-filler (16%), and full-filler (33%) cheeses were produced using either Sephadex beads of varying sizes (20 to 150 µm diameter) or milkfat. Small- and large-strain rheological tests were run on each treatment at 8, 12, and 18 wk after cheese manufacturing. Differences in rheological properties were caused primarily by the main effects of filler volume and type (milkfat vs. Sephadex), whereas filler size had no obvious effect. All treatments showed a decrease in deformability and an increase in firmness as filler volume increased above 25%, although the beads exhibited a greater reinforcing effect and greater energy recovery than milkfat.

Inflammation and dephosphorylation of the tight junction protein occludin in an experimental model of multiple sclerosis.

Multiple sclerosis (MS) is a disease of the CNS in which inflammation, demyelination and neurodegeneration contribute to its initiation and progression. A frequently employed model of MS is experimental autoimmune encephalomyelitis (EAE). Here, to gain new insights into the disease process, an analysis of proteins in extracts of lumbar spinal cord from naïve and EAE rats was undertaken. The data mainly confirm that inflammation and blood-brain barrier (BBB) breakdown are the major hallmarks of disease in this model. Given their importance in the BBB, junctional proteins were further investigated. Occludin, a protein localizing to tight junctions in brain endothelial cells, showed strikingly increased migration in EAE when analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). This increased migration was mimicked by in vitro phosphatase treatment, implying its dephosphorylation in EAE. Occludin dephosphorylation coincided with the onset of inflammation, slightly preceding visible signs of disease, and was just prior to apparent changes in BBB permeability. These findings suggest occludin is a target for signaling processes in EAE, perhaps regulating the response of the BBB to the inflammatory environment as seen in MS.

N-Arylsulfonylindole derivatives as serotonin 5-HT(6) receptor ligands.

A series of N(1)-arylsulfonyltryptamines were found to be potent ligands of the human serotonin 5-HT(6) receptor with the 5-methoxy-1-benzenesulfonyl analogue (19) having the highest affinity. Additionally, it was discovered that a group such as 3-(3-methoxybenzyl)-1,2,4-oxadiazol-5-yl in the 2-position of the indole ring (43) can replace the arylsulfonyl substituent in the 1-position with no loss of affinity. This suggested that the binding conformation of the aminoethyl side chain at this receptor was toward the 4-position of the indole ring and was supported by the fact that the 4-(aminoethyl)indoles (45) also displayed high affinity, as did the conformationally rigid 1,3,4,5-tetrahydrobenz[c,d]indole (49). Molecular modeling showed that 19, 43, and 45 all had low-energy conformers that overlaid well onto 49. Both 19 and 49 had good selectivity over other serotonin receptors tested, with 49 also showing excellent selectivity over all dopamine receptors. In a functional adenylate cyclase stimulation assay, 19 and 49 had no agonist activity, whereas 45 behaved as a partial agonist. Finally, it was shown that 19 had good activity in the 5-HT(2A) centrally mediated mescaline-induced head twitch assay, which implies that it is brain-penetrant.

Current attitudes regarding use of antimicrobial agents: results from physician's and parents' focus group discussions.

Antibiotics are widely prescribed for children with nonspecific upper respiratory tract infections, contributing to the recent emergence of resistant pneumococci. To understand the reasons for the overprescription of antibiotics, we conducted focus groups with parents and with pediatricians and family physicians to assess their attitudes regarding the use of antibiotics. Physicians asserted that their own antibiotic prescribing could be safely reduced. Parental expectation to receive antibiotics was a major factor influencing their overuse of antibiotics. Parents indicated that they would be satisfied with the medical visit even if antibiotics were not prescribed, provided the physician explained the reasons for the decision. This study highlights differences in physician and parent perceptions about antibiotic overuse and suggests that educational efforts to narrow this communication gap will be important for improving antibiotic use.

Proposed new data file standard for flow cytometry, version FCS 3.0.

In 1984, the first flow cytometry data file format was proposed as Flow Cytometry Standard 1.0 (FCS1.0). FCS 1.0 provided a uniform file format allowing data acquired on one computer to be correctly read and interpreted on other computers running a variety of operating systems. That standard was modified in 1990 and adopted by the Society of Analytical Cytology as FCS 2.0. Here, we report on an update of the FCS 2.0 standard which we propose to designate FCS 3.0. We have retained the basic four segment structure of earlier versions (HEADER, TEXT, DATA and ANALYSIS) in order to maintain analysis software compatibility, where possible. The changes described in this proposal include a method to collect files larger than 100 megabytes (not possible in earlier versions of the standard), the inclusion of international characters in the TEXT portions of the file, a method of verifying data integrity using a 16-bit cyclic redundancy check, and increased keyword support for cluster analysis and time acquisition. This report summarizes the work of the ISAC Data File Standards Committee. The complete and detailed FCS 3.0 standard is available through the ISAC office [Sherwood Group, 60 Revere Drive, Ste 500, Northbrook, IL 60062, phone: (847) 480-9080 ext. 231, fax: (847) 480-9282, E-mail: isac@sherwood-group.com] or through the internet at the ISAC WWW site, http://nucleus.immunol.washington.edu/ISAC.ht ml.

Quantitative differences in cell surface expression of class I MHC antigens on murine epidermal Langerhans cells.

Epidermal Langerhans cells are derived from cells of bone marrow origin and, as the primary APC population in the skin, are responsible for initiation of many immune responses. Consequently, cell surface expression of MHC Ags by Langerhans cells is central to their function. Although murine Langerhans cells express class II MHC Ags at high levels, their level of expression of class I MHC has been controversial. In this study, cell surface expression of multiple individual class I MHC Ags on murine epidermal Langerhans cells was analyzed using quantitative immunofluorescence. It was found that Langerhans cells differentially express products of distinct class I genes. Langerhans cells expressed low cell surface amounts of H-2K and Qa-2, whereas expression of surface H-2D and H-2L by the same cells was high. Murine epidermal Langerhans cells therefore express low cell surface amounts of some but not all class I MHC Ags. Differential surface expression of products of distinct class I MHC genes by Langerhans cells may have a profound effect on cutaneous immune responses.

Mesalazine in childhood inflammatory bowel disease.

A study was undertaken in paediatric patients suffering from ulcerative, Crohn's or indeterminate colitis. This aimed to compare the occurrence and tolerance of side-effects arising during treatment with position-release mesalazine (Asacol) with those occurring during previous treatment with sulphasalazine (Salazopyrin). The drugs were used to maintain remission from colitis. The occurrence of adverse reactions was also monitored. Sixty-seven children were assessed for a period of 6 months; 45 of these children received mesalazine after previous treatment with sulphasalazine. The results show that the majority of patients were maintained in remission with either drug, but they reported a preference for position-release mesalazine with respect to ease and frequency of administration when compared to sulphasalazine. No serious adverse reactions arose during mesalazine treatment, compared with three such events during previous sulphasalazine treatment.

Selective culture medium to survey the incidence of Haemophilus species.

A culture medium for the selective isolation of Haemophilus species is described. Bacitracin and nutritional supplements were incorporated in a rich basal agar medium to which rabbit blood was added to distinguish hemolytic species. Colony counts of seven typed strains of H. influenzae on this medium were within practical limits of counts on other media tested for clinical use. The bacitracin medium was as reliable as hemoglobin-agar for detecting H. influenzae and more sensitive for detecting other Haemophilus species in a clinical survey with the advantage of selectivity.