Severe acute respiratory syndrome (SARS) is an acute infectious disease of the respiratory system. Although a novel coronavirus has been identified as the causative agent of SARS, the pathogenic mechanisms of SARS are not understood. In this study, sera were collected from healthy donors, patients with SARS, patients with severe SARS, and patients with SARS in convalescence. The serum concentrations of interleukin-1 (IL-1), IL-4, IL-6, IL-8, IL-10, tumor growth factor beta (TGF-␤), tumor necrosis factor alpha (TNF-␣), and gamma interferon (IFN-␥) were measured by enzyme-linked immunosorbent assays (ELISA). The concentrations of IL-1 and TNF-␣ were not significantly different in different groups. The IL-6 concentration was increased in SARS patients and was significantly elevated in severe SARS patients, but the IL-6 concentrations were similar in convalescent patients and control subjects, suggesting that there was a positive relationship between the serum IL-6 concentration and SARS severity. The concentrations of IL-8 and TGF-␤ were decreased in SARS patients and significantly reduced in severe SARS patients, but they were comparable in convalescent SARS patients and control subjects, suggesting that there was a negative relationship between the IL-8 and TGF-␤ concentrations and SARS severity. The concentrations of IFN-␥, IL-4, and IL-10 showed significant changes only in convalescent SARS patients. The IFN-␥ and IL-4 levels were decreased, while the levels of IL-10 were increased, and the differences between convalescent SARS patients and other patient groups were statistically significant. These results suggest that there are different immunoregulatory events during and after SARS and may contribute to our understanding of the pathogenesis of this syndrome.

Purpose -Empirical studies investigating the antecedents of customer loyalty typically focus on satisfaction. This study aims to develop and test a more comprehensive model of the antecedents of customer loyalty, including satisfaction and inertia. In addition, this study also considers how the effects of satisfaction and inertia on customer loyalty vary with differing levels of the zone of tolerance (ZOT), and how these are likely to change due to customers' alternative attractiveness. Design/methodology/approach -Hierarchical moderated regression analysis was used to test the hypotheses. Findings -The results show that a wider level of the ZOT strengthens the positive effect of inertia on customer loyalty, while also reducing the positive effect of satisfaction. The results also indicate that the negative moderating effect of the ZOT on the relationship between satisfaction and customer loyalty will reduce as alternative attractiveness increases. In contrast, the positive moderating effect of the ZOT on the relationship between inertia and customer loyalty will reduce as alternative attractiveness increases. Originality/value -This study is a first attempt to integrate the ZOT to determine the relative importance of satisfaction and inertia in determining customer loyalty. In addition, this study suggests that customers with higher perceptions of alternative attractiveness are more likely to experience changes in the influence of the ZOT on their loyalty decisions.

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Purpose -The objective of this study is to examine the effect of corporate image, perceived value, and switching costs on customer loyalty in customer/provider relationships of different length. Design/methodology/approach -Five key constructs, namely: corporate image, perceived value, switching costs, customer loyalty, and length of relationship, were employed. Using a systematic sampling technique, student interviewers randomly approached customers exiting hair salons. The final survey sample consisted of 279 respondents. Findings -This paper supports a contingency model with regard to customer loyalty and its antecedents. The results suggest that corporate image impacts customer loyalty in both newer and older relationships. Whereas in newer relationships, corporate image has a cardinal influence on switching costs, in more-established relationships switching costs are influenced primarily by perceived value. In both cases, switching costs influence customer loyalty. Research limitations/implications -As extant research claims that relationship quality, and not length, moderates the relationship between loyalty/repurchase behavior and their antecedents, future research could adopt relationship quality as a moderator to test the model of the present study. Practical implications -The results support the importance of enhancing corporate image to retain newer customers. In longer-established relationships, corporate image remains a determinant of repurchase decisions. However, customer value also has a significant influence on switching costs and loyalty. Originality/value -The current study moves beyond customer-perceived value, switching costs, and corporate image to demonstrate that relationship length has a significant influence on customer loyalty.

ICP22 is a multifunctional herpes simplex virus 1 (HSV-1) immediate early protein that functions as a general repressor of a subset of cellular and viral promoters in transient expression systems. Although the exact mechanism of repression remains unclear, this protein induces a decrease in RNA polymerase II Serine 2 (RNAPII Ser-2) phosphorylation, which is critical for transcription elongation. To characterize the mechanism of transcriptional repression by ICP22, we established an in vivo transient expression reporter system. We found that ICP22 inhibits transcription of the HSV-1 α, β and γ gene promoters. The viral tegument protein VP16, which plays vital roles in initiation of viral gene expression and viral proliferation, can overcome the inhibitory effect of ICP22 on α-gene transcription. Further immunoprecipitation studies indicated that both ICP22 and VP16 bind to positive transcription elongation factor b (P-TEFb) and form a complex with it in vivo. We extended this to show that P-TEFb regulates transcription of the viral α-gene promoters and affects transcriptional regulation of ICP22 and VP16 on the α-genes. Additionally, ChIP assays demonstrated that ICP22 blocks the recruitment of P-TEFb to the viral promoters, while VP16 reverses this blocking effect by recruiting P-TEFb to the viral α-gene promoters through recognition of the TAATGARAT motif. Taken together, our results suggest that ICP22 interacts with and blocks the recruitment of P-TEFb to viral promoter regions, which inhibits transcription of the viral gene promoters. The transactivator VP16 binds to and induces the recruitment of P-TEFb to viral α-gene promoters, which counteracts the transcriptional repression of ICP22 on α-genes by recruiting p-TEFb to the promoter region.