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Biomedical subjects

S Yan

Publications and source records attributed to S Yan.

149 records · Page 9Linked to original sources
PubMedDate not supplied

Control of intestinal allograft rejection by FTY720 and costimulation blockade.

INTRODUCTION: The clinical application of small bowel transplantation (SBTx) is hampered by its pronounced immunogenicity. In this study we examined the effects of the novel immunosuppressant FTY720 and costimulation blockade by an anti-CD40L mAb (MR-1) in a stringent mouse model of SBTx. METHODS: SBTx was performed in mice with a full MHC mismatch (donors: C3H=H-2(k); recipients: C57BL/6=H-2(b)). Recipients were divided into four groups: 1, untreated group; 2, MR1 monotherapy (500 microg IV on days 0, 2, 4, and 7); 3, FTY720 monotherapy (1 mg/kg body weight PO for 14 consecutive days after transplantation); 4, FTY720 plus MR1-treated group. Graft rejection grades were assessed by H&E staining. Graft mesenteric lymph nodes (MLNs), Peyer's patches (PPs), as well as intraepithelial lymphocytes (IELs) and lamina propria lymphocytes (LPLs) were analyzed by flow cytometry and three-color immunofluorescence staining. RESULTS: Neither FTY720 nor MR1 monotherapy was efficient in preventing the rejection of mouse intestinal allografts, whereas FTY720 plus MR1 profoundly inhibited the rejection response at the 14th posttransplant day. The infiltration of host lymphocytes was reduced in graft MLNs, PPs, IELs, and LPLs by FTY720 therapy. FTY720 plus MR1 inhibited host CD8(+) T-cell infiltration in graft LPLs when compared with grafts treated with FTY720 only. Additionally, two subpopulations, CD11b(+high) Gr1(-) and CD11b(+intermediate) Gr1(+) cells, were decreased in FTY720-treated grafts. CONCLUSIONS: FTY720 plus MR1 efficiently delayed intestinal allograft rejection in a mouse model by preventing the infiltration of host lymphocytes, particularly of CD8(+) cells.

Animals↗
PubMedDate not supplied

Immunosuppression is not required for reactivation of latent murine cytomegalovirus.

We have shown, for the first time, that TNF induces expression of MCMV IE RNA in the lungs of latently infected mice in the absence of immunosuppression. These initial data suggest that TNF may play an important role in the reactivation of latent MCMV, in the absence of immunosuppression, and provide a provocative insight into the mechanisms of CMV reactivation. Studies are in progress to determine whether genes associated with later stages of the viral life cycle are induced by TNF and whether infectious virus is produced.

Animals↗
PubMedDate not supplied

The age pattern of fecundability: an analysis of French Canadian and Hutterite birth histories.

This paper analyzes the age pattern of effective fecundability from populations with no evidence of deliberate fertility control using a new convolution model of fecundability. The analysis is based on a sample of Hutterite birth histories from the mid-20th century, and birth histories of French Canadians from the 17th and 18th centuries. The main findings are as follows: 1) the level of effective fecundability is higher among the French Canadians compared to the Hutterites; 2) effective fecundability peaks at age 20 for the Hutterites, and in the early to mid-20s for the French Canadians; 3) Hutterite effective fecundability declines almost linearly from age 20 to 45, and French Canadian effective fecundability declines slowly from its peak to the early 30s, and more rapidly at older ages; and 4) the duration of postpartum amenorrhea is longer for the French Canadians than for the Hutterites. Because of the shorter periods of postpartum amenorrhea the Hutterites have about the same average number of children as the French Canadians, even though the French Canadians have higher effective fecundability.

Adolescent↗
PubMedDate not supplied

Impact of irritable bowel syndrome on quality of life and resource use in the United States and United Kingdom.

BACKGROUND: Although irritable bowel syndrome (IBS) is not a life-threatening condition, it can have a serious impact on a patient's daily activities and quality of life. This effect on quality of life has not been compared previously across different cultures. METHODS: We compared measures of health-related quality of life and health care resource utilization using a cross-sectional point-in-time postal survey of a random sample of 500 members of the International Foundation for Functional Gastrointestinal Disorders in the US and 500 members of the IBS Network support group in the UK. The analysis was limited to persons who reported that a physician had told them they had IBS. A general health status questionnaire, the SF-36, and a disease-specific questionnaire, the Irritable Bowel Syndrome Quality of Life questionnaire (IBSQOL), were self-administered as part of the survey to measure health-related quality of life. Results on the SF-36 were compared with published normative data for adults in the US and UK with and without chronic diseases. RESULTS: The UK group (n = 343) reported significantly poorer quality of life on the SF-36 and on four parameters of the IBSQOL than did the US group (n = 287). The general health status of persons with IBS in either country was much poorer compared with that of general populations in the respective countries. Health care resource utilization (i.e. emergency room, doctor and hospital outpatient visits) of persons with IBS was similar in the two countries, as was the direct effect of IBS on employment. Nearly one third of those surveyed missed at least 1 day of work due to IBS in the previous 4 weeks, and a greater percentage cut back in their work or activities due to IBS. Taken together, average time lost or cut back amounted to nearly 5 days or 1 work-week. CONCLUSION: IBS has a significant impact on quality of life and resource use in both the US and UK. The effect on quality of life, however, appears to be greater in the UK than in the US.

Absenteeism↗