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- Lidén, Maria, et al.
(författare)
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Cow's milk protein sensitivity assessed by the mucosal patch technique is related to irritable bowel syndrome in patients with primary Sjögren's syndrome
- 2008
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Ingår i: Clinical and Experimental Allergy. - : Wiley. - 0954-7894 .- 1365-2222. ; 38:6, s. 929-935
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Tidskriftsartikel (refereegranskat)abstract
- INTRODUCTION: Patients with primary Sjögren's syndrome (pSS) are reported to have a variety of gastrointestinal symptoms partly attributed to an overrepresentation of celiac disease. We have observed that irritable bowel syndrome (IBS)-like symptoms are frequent complaints in this patient group. Allergic manifestations to various drugs are also common in pSS. A role of food allergy in IBS has been proposed. OBJECTIVE: This study is aimed at evaluating the mucosal response to rectal challenge with cow's milk protein (CM) in patients with pSS and relates possible CM reactivity to their intestinal symptoms. Methods: A rectal challenge with CM was performed in 21 patients with pSS and 18 healthy controls. Fifteen hours after challenge the mucosal production of nitric oxide (NO) and the release of myeloperoxidase (MPO) as signs of mucosal inflammatory reaction were measured using the mucosal patch technique. RESULTS: Eight out of 21 patients with pSS had a definite increase of mucosal NO synthesis and the luminal release of MPO after rectal CM challenge. This sign of milk sensitivity was not linked to IgG/IgA antibodies to milk proteins. The symptoms for IBS according to Rome III criteria were fulfilled in 13 patients. All patients who were CM sensitive suffered from IBS. In a small open study, patients reactive to CM reported an improvement of intestinal symptoms on a CM-free diet. CONCLUSION: A rectal mucosal inflammatory response after CM challenge is seen in 38% of patients with pSS as a sign of CM sensitivity. IBS-like symptoms were common in pSS, linked to CM sensitivity.
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- Lidén, Maria, et al.
(författare)
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Gluten sensitivity in patients with primary Sjögren's syndrome
- 2007
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Ingår i: Scandinavian Journal of Gastroenterology. - : Informa UK Limited. - 0036-5521 .- 1502-7708. ; 42:8, s. 962-967
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Tidskriftsartikel (refereegranskat)abstract
- Objective. To evaluate the rectal mucosal response to gluten as an indication of gluten sensitivity in patients with primary Sjögren's syndrome (pSS). Material and methods. Rectal challenges with wheat gluten were performed in 20 patients with pSS and 18 healthy control subjects. Fifteen hours after challenge the mucosal production of nitric oxide (NO) was measured. Results. Five patients with pSS had a significant increase in the luminal release of NO after the rectal gluten challenge, indicating gluten sensitivity. All were HLA-DQ2 and/or -DQ8-positive. Two of the patients with increased NO had antibodies against transglutaminase and a duodenal biopsy showed an absolutely flat mucosa consistent with coeliac disease in one of the patients. Before gluten challenge, 15 of the Sjögren's syndrome (SS) patients reported gastrointestinal symptoms, and 8 reported intolerance to various food products. No correlation was found between gluten sensitivity and self-reported food intolerance or gastrointestinal symptoms. Conclusions. Rectal mucosal inflammatory response after gluten challenge is often seen in patients with pSS, signifying gluten sensitivity. However, this reactivity is not necessarily linked to coeliac disease.
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- Lidén, Maria, 1954-
(författare)
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Gut Mucosal Reactivity to Gluten and Cow´s Milk Protein in Rheumatic Diseases
- 2009
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This thesis comprised patients with chronic rheumatic diseases. The studies aimed to elucidate food sensitivity by measuring mucosal inflammatory reactivity and thereby a possible link between the gut and joints. In all the studies, the mucosal path technique was used to evaluate the rectal mucosal response to rectal challenge with gluten and/or cow’s milk protein (CM). In some patients with primary Sjögren’s syndrome (pSS) and the genetic susceptibility genes HLA DQ2, mucosal reactivity measured with nitric oxide (NO) was found after rectal gluten challenge without detectable serum antibodies to gluten or transglutaminase. This gluten sensitivity was not linked to coeliac disease. After rectal CM challenge, a rectal mucosal inflammatory response measured with NO and myeloperoxidase (MPO) was detected in 38% of pSS patients, all of whom fulfilled the criteria for irritable bowel syndrome. In a questionnaire study of self-experienced adverse reactions to food, 27% of patients with rheumatoid arthritis (RA) reported intolerance to various foods and CM in particular. After rectal CM challenge performed in RA patients (n=27), strong mucosal reactivity to CM was observed in a few patients and a moderate increase in 23%. After gluten challenge, a moderate increase in mucosal reactivity was found in 35% of patients. No correlation to self-perceived intolerance and mucosal reactivity measured with NO and MPO was seen. Inflammation of the gut is a prominent feature of spondyloarthropathies (SpA). After rectal challenges with CM protein and gluten, an increase in rectal NO production was seen in 26% and 19% respectively (p<0.001). An increase in the mucosal release of MPO as a sign of neutrophil activation was seen in the CM- and gluten-sensitive patients. NO production in SpA patients was more enhanced compared with RA and pSS patients and could contribute to the increased barrier permeability described in SpA patients.
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- Sandén, Anna Maria, 1968-
(författare)
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Impact of glucose feed rate on productivity and recombinant protein quality in Escherichia coli
- 2005
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The goal of this work was to contribute to the fed-batch process optimisation task by deriving parameters that have considerable impact on productivity as well as product quality The chosen parameters were I) the design of the glucose feed profile, II) the choice of induction strategy, with respect to the method of addition, and III) the time of the induction, with respect to the specific glucose consumption rate.The present fed-batch experiments using the lacUV5-promoter, for production of b-galactosidase, have shown that a high glucose feed rate gives a specific production rate, qp, that is twice as high, after induction, compared to a feed rate that is 2.5 times lower. The constant accumulation of lacZ-mRNA indicates that the translational capacity is initially limiting the synthesis machinery, but after four hours of maximum specific production and a corresponding drop in lacZ-mRNA production, the cultivation is likely to be transcription limited. The high feed-rate system resulted in high accumulation of β-galactosidase, corresponding to 40% of total cellular proteins.By design of feed profiles in a fed-batch process the detrimental effects of overflow metabolism, giving acetic acid formation, can be avoided. However, the results show that a one-dose addition of isopropyl-β-D-galactopyranoside (IPTG), provokes a non-growth associated production of acetic acid. This response can be alleviated by; lowering the inducer concentration (in this case to below 165 μM), by further reducing the feed rate of glucose or by using alternative induction methods. The use of a stepwise addition or a feed of IPTG thus delayed and reduced the level of acetic acid accumulation. It was also shown that a small change in the time-point of induction lead to large variability, regarding both productivity and acetic acid accumulation, in a fed-batch cultivation,In order to further investigate the protein quality two additional proteins were studied in fed-batch cultivations using high and low glucose feed. The aim was to prove the hypothesis that the feed related change in the rate of synthesis of the nascent polypeptide controls the product quality. For the two proteins: Zb-MalE (wt) and Zb-MalE31 (mutant), the transcription rate, in terms of amount of IPTG, and translation rate, in terms of changes in feed rate, influences the percentage of inclusion body formation and degradation of nascent polypeptide. The data show a higher rate of inclusion body formation for the model protein Zb-MalE31 during high feed rate cultivations, as well as at high levels of inducer. Furthermore, the rate of proteolysis was significantly higher for a high feed rate. The high feed rate thus results in a higher rate of synthesis but a lower corresponding quality, for the model proteins studied.In the present investigation of fed-batch cultivations using several different expression vectors, it was found that the central alarmone guanosine tetraphosphate (ppGpp) was formed at both high and low feed rates upon induction. It could be shown, however, that by secretion of Zb-MalE to the periplasm, the stringent response could be avoided. This might be due to the decreased burden on the host where the secretion of product further seems to make the cell able to redirect the carbon flux from overflow metabolism, since no acetic acid was produced. The secretion also demonstrates that the growth arrest could be aborted, which is otherwise gained in the PmalK production system.A novel fed-batch process based on the promoters for the universal stress proteins A and B (PuspA, PuspB) was designed to make use of these powerful promoters in an industrial production context. It was concluded that the process had to start from a high specific growth rate and induction was performed once a limiting feed started. This was done to purposely induce the stringent response and/or acetic acid accumulation since this was required for induction. In the suggested system, induction has to be performed and maintained at continuous substrate feeding, whilst avoiding exceeding the cellular capacity, since the stationary phase starvation alone did not lead to production. In conclusion, a new stress induction based production system was achieved resulting in high accumulations of product protein without any detected metabolic side effects.
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