A radiosensitive APC activity dissociates IL-2 secretion and activation-induced cell death by autoreactive T cell hybridomas

T cell hybridomas were generated from a LEW rat T cell line specific for the uveitogenic peptide bov-B1 of bovine retinal S-antigen. Using these autoreactive hybridomas, IL-2 production and activation-induced cell death (AICD) were dissociated as outcomes of activation. The self-reactive hybridomas secrete IL-2 and undergo AICD in response to antigen presented by non-irradiated syngeneic splenocytes, whereas antigen presentation by irradiated splenocytes induced only AICD. IL-2 production by a non-self reactive hybridoma was unaffected by irradiation of the APC. Pretreatment of the APC with phorbol ester or lipopolysaccharide and IL-4 protected their ability to induce IL-2 secretion after gamma-irradiation. Although the co-stimulation-blocking reagent CTLA-4-Ig mimicked the effect of gamma-irradiation by preventing IL-2 secretion but not AICD, B7 expression on the APC was not radiosensitive, nor did co-stimulation, provided 'in trans' with a B7-expressing third-party cell, reconstitute antigen-specific hybridoma IL-2 secretion in response to irradiated APC. In summary, the data show that IL-2 secretion and AICD of a self-reactive T cell hybridoma can be dissociated as consequences of TCR occupancy in the presence of a functional co-stimulatory signal. It is proposed that the signals producing these events are transduced through the TCR-CD3 complex alone and reflect the differential outcomes of high- and low-affinity interactions.     

Calcium oxalate crystallization in urine of healthy men and women: a comparative study

This study aimed to compare calcium oxalate (CaOx) crystallization in undiluted urine from healthy men and women with the object of clarifying the difference in stone incidence between the two sexes. Twenty-four hour urine specimens were collected from 37 men and 28 women. Urinary pH, and concentrations of Ca, oxalate and urate were measured, and indices of crystallization determined by Coulter Counter particle analysis following induction of CaOx crystallization by addition of oxalate. The amount of oxalate required to induce crystallization was significantly (p < 0.01) higher in females than in males, as was the overall particle volume deposited after 90 minutes incubation (p < 0.006). Scanning electron microscopy revealed larger individual crystals in female urine, and a greater degree of crystal aggregation in male urine, although the average overall size of the precipitated crystal particles did not differ between the two sexes. There were no significant differences between men and women with regard to median pH, or Ca and oxalate concentrations, but the median urate concentrations were slightly, but significantly, higher (p < 0.05) in the women's urines than in the men's. It was concluded that the greater risk of CaOx stones in men is related to an increased propensity to nucleate CaOx crystals per se, rather than to a tendency to form larger crystalline particles.     

Welfare implications of identification of cattle by ear tags

The damage caused by ear tags used for identification was studied by examining the ears of normal beef cattle and cull cows after slaughter, and by comparing the effects of metal and polyurethane ear tags in calves which had been double-tagged in the same ear. Metal tags were associated with more damage to the ears than polyurethane tags, the difference being most marked in the young calves, in which slight changes were found in 36.6 per cent and severe changes in 9.8 per cent of ears. There was a high incidence of blood around the point of insertion of the metal tags at three weeks old, but with the polyurethane tags only one calf showed slight evidence of blood around the point of insertion. In the beef cattle fitted with metal tags, a slight reaction was recorded in 40 per cent, a moderate reaction in 17 per cent and significant changes were found in 12 per cent of ears. By comparison, 16 per cent of ears with polyurethane tags showed only a slight reaction, and 80 per cent of the polyurethane tags were considered to be a good fit, compared with 37 per cent of metal tags. More changes were observed in the ears of the cull cows, with 23.5 per cent of ears with polyurethane tags being free from damage, compared with only 2.9 per cent of ears with metal tags.     

Psychopathy and dual-task performance under focusing conditions

Thirty psychopathic and 30 nonpsychopathic right-handed White male inmates (selected through R.D. Hare's, 1985b, Psychopathy Checklist) completed concurrent visual and auditory tasks under conditions focusing attention on the visual (i.e., primary) task. Performance indices tested 3 related hypotheses for cognitive deficits in psychopathic individuals: reduced attention to secondary tasks because of excess attention to immediate goals (interference), deficient shifts of attention, and reduced breadth of attention. The absence of differences in primary and secondary task accuracy contradicts the interference hypothesis. However, a trend toward deficits for psychopathic individuals responding with the right hand to primary task targets appearing after other targets, suggests poorer shifting of attention when left-hemisphere resources are engaged. Psychopathic individuals also overresponded to distractors following targets suggesting reduced attention to a peripheral dimension of two-dimensional stimuli.     

Potato lectin: a three-domain glycoprotein with novel hydroxyproline-containing sequences and sequence similarities to wheat-germ agglutinin

Potato (Solanum tuberosum) tuber lectin is a chitin-binding, hydroxyproline-rich glycoprotein, which may be involved in the defence mechanism of the plant. We had previously obtained evidence that it consists of at least two very dissimilar domains. The aim was to use a combination of accurate determinations of molecular weight and protein sequencing to gain more accurate information on the domains. Accurate determinations of the molecular weight of the lectin by a MALDI mass spectrometer have shown that the subunit molecular weight is 65,500 (+/- 1100) and that of a totally deglycosylated sample is 31,250 (+/- 30). This means that the lectin is 52.3 (+/- 1)% carbohydrate with a considerable number of glycoforms being present. Partial sequences and other analyses are consistent with the existence of three distinct domains. These are: (1) an N-terminal region which is rich in proline but poor in hydroxyproline; (2) a glycosylated region with a glycosylated molecular weight of 45,300 (+/- 1100) and a deglycosylated molecular weight of 11,050 (+/- 50) which is extremely rich in glycosylated hydroxyproline residues with a similar sequence to extensins; and (3) a cystine-rich domain which has the sugar binding site shows partial conservation of a repeated motif common to many chitin-binding proteins of the hevin family including wheat-germ agglutinin. The closest similarity seems to be to the sequence of potato basic chitinase.     

Dammarane saponins from Panax ginseng

From the dried roots of Panax ginseng two new minor dammarane saponins named koryoginsenoside-R1 and -R2 were isolated, along with fourteen known saponins. On the basis of spectral and chemical evidence, the structure of the new saponins were elucidated as 6-O-[trans butenoyl-(1-->6)-beta-D-glucopyranosyl]-20-O-beta-D- glucopyranosyl dammar-24-en-3 beta,6 alpha,12 beta,20(S)-tetrol and 3-O-[beta-D-glucopyranosyl-(1-->2)-beta-D-glucopyranosyl]-20-O-[beta-D- glucopyranosyl-(1-->6)-beta-D-glucopyranosyl] dammar-22-en-3 beta,12 beta, 20(S),- 25-tetrol, respectively.     

A pythagorean hodograph quintic spiral

A polynomial curve with a Pythagorean hodograph has the properties that its arc-length is a polynomial of its parameter, and its offset is a rational algebraic expression. A quintic is the lowest degree Pythagorean hodograph curve that may have an inflection point and that inflection point allows a segment of it to be joined to a straight line segment while preserving continuity of curvature, continuity of position, and continuity of tangential direction. The curvature of a spiral varies monotonically with arc-length. Spiral segments are useful in the design of fair curves. A Pythagorean hodograph quintic spiral is presented which allows the design of fair curves in a based system. It is also suitable for applications such as highway design in which the clothoid has traditionally been used.     

Activation of the gene encoding decay accelerating factor following nerve growth factor treatment of sensory neurons is mediated by promoter sequences within 206 bases of the transcriptional start site

This study was designed to develop a quick methodology to assess the healthcare needs of a rural community and to determine what factors make these communities 'happy' or 'unhappy' with respect to medical service provision. Two rural shires of approximately 4000 people each were chosen from different health regions of Western Australia. The methodology consisted of interviews with healthcare providers and key community informants as well as a community questionnaire. The interviewing process showed that key community informants offered no new information in addition to that already provided by the healthcare providers. Furthermore, all key points would have been covered by interviewing approximately 60% of all healthcare providers in each community. Hand delivery of the community questionnaire yielded the highest response rate. The level of community satisfaction with general practitioner (GP) and hospital services determines whether a community is medically 'happy' or 'unhappy'.     

Self-reported physical activity in a rural county: a New York county health census

We have previously shown that phosphatidylinositol (PtdIns) 3'-kinase is activated by the binding of proteins or peptides containing the phosphorylated motif Y(P)XXM. In the present study, we examine interactions between PtdIns 3'-kinase and the human insulin receptor, which contains a C-terminal phosphorylation site in the sequence Y1322THM. Partially purified insulin receptors bound tightly to bacterial fusion proteins containing the N- or C-terminal SH2 domains from PtdIns 3'-kinase regulatory subunit (p85). In contrast, a mutant insulin receptor, truncated by 43 amino acids at the C terminus (IR delta CT), bound poorly to the SH2 domains; these mutant receptors have normal kinase activity but lack the Y1322THM motif. Similarly, incubation with wild-type receptors increased the activity of immunopurified PtdIns 3'-kinase, whereas incubation with IR delta CT receptors did not affect PtdIns 3'-kinase activity. Activation of PtdIns 3'-kinase by the wild-type receptor was mimicked by a tyrosyl phosphopeptide derived from the insulin receptor C terminus and containing the Y1322THM motif; non-phosphorylated peptide did not affect activity. Thus, the insulin receptor C terminus activates PtdIns 3'-kinase in vitro by binding to the SH2 domains of the 85-kDa regulatory subunit. These data support the hypothesis that binding of tyrosyl-phosphorylated receptors to p85 SH2 domains is a general mechanism for PtdIns 3'-kinase activation, and they suggest that direct interactions between the insulin receptor and PtdIns 3'-kinase may provide an alternative pathway for the activation of this enzyme by insulin.