Inflammatory bowel disease (IBD) has long been considered a disease that affects predominantly a Western population. The incidence and prevalence rates from Asian populations are much lower in comparison. More recent data, however, have shown significantly higher rates in Asians and time trend studies have shown an increase in the incidence of ulcerative colitis (UC) and a similar but lower rise in Crohn's disease (CD). The epidemiological changes that are taking place mirror that of the Western experience seen 50 years previously and seem to occur in parallel with the rapid socioeconomic development taking place in Asia. It appears that certain racial groups are more prone than others to develop IBD. For instance, Indians in South‐East Asia have higher rates compared to Chinese and Malays. While there is host genetic predisposition, environmental factor(s) may be responsible for this difference. Migrant studies of South Asians in the UK, where second‐generation immigrants have assumed incidence rates as high as the indigenous whites and Asian Jews who develop high incidence rates comparable to Jews from Europe or North America in Israel point to the role of environmental factors. It is unclear which specific factors are responsible. Studies have suggested a change in diet to a more Westernized one may underlie this epidemiological change in the Asian population. It is likely that there are racial groups amongst Asians who are more susceptible to IBD and who will demonstrate a higher frequency of IBD when exposed to putative environmental factors. 相似文献
A human monoclonal IgG1κ protein (Hom) was found to possess two species of light chain with molecular weights of 23,000 and 28,000 respectively. The difference in mass was due to the presence of a carbohydrate prosthetic group on the 28,000 dalton species. The two species of light chain were separated by chromatography on CM-cellulose. Circular dichroism failed to detect any significant differences in conformation between the glycosylated and non-glycosylated forms and both species recombined with a heavy chain in an identical fashion as judged by difference spectroscopy. An anti-idiotypic antibody raised against the glycosylated Fab-fragment of IgGlHom was unable to distinguish between this species and the non-glycosylated Fab fragment, suggesting that the structure of the combining site is identical or very similar in both molecules. Amino-acid sequence analyses showed that both light chains had an identical sequence up to residue 41. Further studies on the glycosylated light chain, using o-iodosobenzoic acid fragments, localized the carbohydrate attachment site to asparagine 107, the penultimate residue of the Jκ region which links Vκ to Cκ. The sequence around the attachment site was Asn-Arg-Thr which satisfies the requirements for an acceptor sequence. The non-glycosylated light chain was found to have the same sequence in this region indicating that the absence of glycosylation was not due to the lack of an acceptor sequence. A kinetic mechanism has been proposed to account for the incomplete glycosylation of the light chains of IgG1Hom in which there is a competition between the rate of folding of the nascent polypeptide and the rate of attachment of core sugars via the dolichol pyrophosphate pathway. 相似文献
Introduction: Community acquired pneumonia (CAP) is associated with high rates of morbidity and mortality, especially among the elderly. Antibiotic treatment for CAP in the elderly is particularly challenging for many reasons, including compliance issues, immunosuppression, polypharmacy and antimicrobial resistance. There are few available antibiotics that are able to address these concerns.
Areas covered: After a systematic review of the current literature, we describe seven novel antibiotics that are currently in advanced stages of development (phase 3 and beyond) and show promise for the treatment of CAP in those over the age of 65. These antibiotics are: Solithromycin, Pristinamycin, Nemonaxacin, Lefamulin, Omadacycline, Ceftobiprole and Delafloxacin. Using a novel conceptual framework designed by the present authors, known as the ‘San Antonio NIPS model’, we evaluate their strengths and weaknesses based on their ability to address the unique challenges that face the elderly.
Expert opinion: All seven antibiotics have potential value for effective utilization in the elderly, but to varying degrees based on their NIPS model score. The goal of this model is to reorganize a clinician’s focus on antibiotic choices in the elderly and bring attention to a seldom discussed topic that may potentially become a health-care crisis in the next decade. 相似文献
An article recently published in this journal argues that the life expectancies (and other mortality statistics) produced by models of the HIV/AIDS epidemic in Southern Africa are inconsistent, and questions their reliability. To demonstrate the argument, the author of that paper derived empirical estimates of several mortality statistics from three different sources of data and, on the grounds that the estimates of life expectancy for 2001 and 2006 are somewhat higher than is typically estimated by projection models, concludes that the empirical evidence supports the theoretical view outlined in that paper. If correct, the reasoning (and its empirical demonstration) could be construed as a strong challenge to a dominant orthodoxy surrounding the estimation of mortality statistics in an era of HIV/AIDS and offering some comfort to governments with low Human Development Indices because of the index's dependence, inter alia, on estimates of life expectancy at birth derived from such models. This paper shows how, on theoretical, methodological and empirical grounds, the reasoning and estimates in the paper are severely flawed, and thus that the conclusions drawn in that paper are unjustified. 相似文献
A severe case of aplasia cutis congenita in a preterm infant is described. Although major problems with thermoregulation and fluid balance were anticipated, these parameters were relatively easy to control once the patient was stabilized. Meticulous skin care and rapid formation of a membranous-like fibrous tissue layer covering the denuded areas probably played an important role in minimizing excessive fluid and heat loss. The prognosis in aplasia cutis congenita is determined by the underlying associated anomalies, the severity of skin lesions and, in our case, the maturity of the infant who died from complications of prematurity. 相似文献