Direct and indirect transmission of four Salmonella enterica serotypes in pigs

<p>Abstract</p> <p>Background</p> <p>Feed-borne spread of <it>Salmonella </it>spp. to pigs has been documented several times in recent years in Sweden. Experiences from the field suggest that feed-associated serotypes might be less transmittable and subsequently easier to eradicate from pig herds than other serotypes more commonly associated to pigs. Four <it>Salmonella </it>serotypes were selected for experimental studies in pigs in order to study transmissibility and compare possible differences between feed-assoociated (<it>S </it>Cubana and <it>S </it>Yoruba) and pig-associated serotypes (<it>S </it>Derby and <it>S </it>Typhimurium).</p> <p>Methods</p> <p>Direct contact transmission was studied in four groups of pigs formed by six 10-week-old salmonella negative pigs commingled with two fatteners excreting one of the four salmonella serotypes. Indirect transmission was studied by putting six 10-week-old salmonella negative pigs in each of four salmonella contaminated rooms. Each room had previously housed a group of pigs, excreting one of the four selected serotypes.</p> <p>All pigs were monitored for two weeks with respect to the faecal excretion of salmonella and the presence of serum antibodies. At the end of the trial, eight samples from inner tissues and organs were collected from each pig at necropsy.</p> <p>Results</p> <p>In the four direct transmission groups, one pig shed <it>Salmonella </it>(Cubana) at one occasion. At necropsy, <it>S </it>Typhimurium was isolated from one pig.</p> <p>In the indirect transmission groups, two pigs in the Yoruba room and one pig in each of the other rooms were excreting detectable levels of <it>Salmonella </it>once during the study period of two weeks. At necropsy, <it>S </it>Derby was isolated from one of six pigs in the Derby room and <it>S </it>Typhimurium was isolated from four of the six pigs in the Typhimurium room.</p> <p>No significant serological response could be detected in any of the 48 pigs.</p> <p>Conclusions</p> <p>These results show that all four selected serotypes were able to be transmitted in at least one of these field-like trials, but the transmission rate was low in all groups and no obvious differences between feed-associated and pig-associated serotypes in the transmission to naïve pigs and their subsequent faecal shedding were revealed. However, the post mortem results indicated a higher detection of <it>S </it>Typhimurium in the ileocecal lymph nodes of pigs introduced into a contaminated environment in comparison with the other three serotypes.</p

Prognostic model to predict postoperative acute kidney injury in patients undergoing major gastrointestinal surgery based on a national prospective observational cohort study.

Background: Acute illness, existing co-morbidities and surgical stress response can all contribute to postoperative acute kidney injury (AKI) in patients undergoing major gastrointestinal surgery. The aim of this study was prospectively to develop a pragmatic prognostic model to stratify patients according to risk of developing AKI after major gastrointestinal surgery. Methods: This prospective multicentre cohort study included consecutive adults undergoing elective or emergency gastrointestinal resection, liver resection or stoma reversal in 2-week blocks over a continuous 3-month period. The primary outcome was the rate of AKI within 7 days of surgery. Bootstrap stability was used to select clinically plausible risk factors into the model. Internal model validation was carried out by bootstrap validation. Results: A total of 4544 patients were included across 173 centres in the UK and Ireland. The overall rate of AKI was 14·2 per cent (646 of 4544) and the 30-day mortality rate was 1·8 per cent (84 of 4544). Stage 1 AKI was significantly associated with 30-day mortality (unadjusted odds ratio 7·61, 95 per cent c.i. 4·49 to 12·90; P < 0·001), with increasing odds of death with each AKI stage. Six variables were selected for inclusion in the prognostic model: age, sex, ASA grade, preoperative estimated glomerular filtration rate, planned open surgery and preoperative use of either an angiotensin-converting enzyme inhibitor or an angiotensin receptor blocker. Internal validation demonstrated good model discrimination (c-statistic 0·65). Discussion: Following major gastrointestinal surgery, AKI occurred in one in seven patients. This preoperative prognostic model identified patients at high risk of postoperative AKI. Validation in an independent data set is required to ensure generalizability

Personal taxes, shareholder valuation of riskless corporate taxable cash flows, and management investment decisions

Purpose: To analyse the net present value (NPV) rule for corporate investments incorporating shareholder personal taxes, under the classical system of taxing corporate profits. Design/methodology/approach: The after-tax payoffs to shareholders are calculated, comparing immediate distribution as dividends of corporate funds available for investment with future after-tax dividend distributions if corporate funds are invested. Findings: Shareholders will disagree on the optimal corporate NPV rule. If, as in widely held public companies, corporate management are unaware of the marginal personal tax rate of shareholders, then the only rule which will accept investment projects that no shareholder would want the company to reject, is the rule which discounts after-corporate-tax cash flows at a before-tax discount rate. Research limitations/implications: The analysis is based on the classical system of taxing corporate profits. A number of countries have adopted an integrated system of corporate taxation. The analysis may or may not extend to such alternative systems. Practical implications - Simplifies the choice of NPV rules for corporate management, under a classical tax system. Originality/value: The widely held view that after-corporate-tax discount rates should be used in discounting after-corporate-tax cash flows is shown to be inadequate

Sensitivity to glucocorticoids is decreased in relapsing remitting multiple sclerosis

Endogenous glucocorticoids (GC), which are under control of the hypothalamic-pituitary-adrenal axis, play an important role in controlling chronic inflammatory demyelinating diseases, like multiple sclerosis (MS). Increased hypothalamic-pituitary-adrenal axis activity has been found in MS patients and appeared to be negatively associated with acute inflammation. Exogenous GC are frequently used to treat relapses in MS, but the response to this treatment differs among patients, suggesting differences in sensitivity to GC. Previous, relatively small studies investigating GC sensitivity have yielded conflicting results. In the present study, we have investigated GC sensitivity in peripheral blood cells of MS patients (n = 117) and healthy controls (n = 45). GC sensitivity was measured by the in vitro suppressive effect of GC on lipopolysaccharide-stimulated TNF-alpha production. Blood cells of MS patients, especially relapsing remitting MS patients, were less sensitive to GC compared with blood cells of healthy controls. This turned out to be unrelated to previous treatment with exogenous GC expressed as frequency of courses of iv steroids or interval since last course. The use of interferon beta was found to be associated with a lower GC sensitivity. However, after correction for the use of interferon beta, relapsing remitting MS patients remained less sensitive to G

Proteolytic shedding of the macrophage scavenger receptor CD163 in multiple sclerosis

The scavenger receptor CD163 is selectively expressed on tissue macrophages and human monocytes. CD163 has been implicated to play a role in the clearance of hemoglobin and in the regulation of cytokine production by macrophages. Membrane CD163 can be cleaved by matrix metalloproteinases (MMP) resulting in soluble CD163 (sCD163). In the present report the shedding of CD163 was investigated in multiple sclerosis (MS). An upregulation of plasma sCD163 and a down regulation of membrane CD163 in MS patients compared to healthy controls was observed. The levels of plasma sCD163 correlated with plasma MMP-9 levels in controls, but not in MS patients. Moreover, evidence was obtained for CD163-cleaving MMP activity in plasma of MS patients. Finally, the increased proteolytic shedding of CD163 correlated to reduced plasma levels of circulating inflammatory cytokines. Collectively, our results provide evidence for proteolytic shedding of CD163 in MS and suggest a possible link to cytokine productio