Tissue viscoelasticity is related to tissue composition but may not fully predict the apparent-level viscoelasticity in human trabecular bone - An experimental and finite element study.

Trabecular bone is viscoelastic under dynamic loading. However, it is unclear how tissue viscoelasticity controls viscoelasticity at the apparent-level. In this study, viscoelasticity of cylindrical human trabecular bone samples (n=11, male, age 18-78 years) from 11 proximal femurs were characterized using dynamic and stress-relaxation testing at the apparent-level and with creep nanoindentation at the tissue-level. In addition, bone tissue elasticity was determined using scanning acoustic microscope (SAM). Tissue composition and collagen crosslinks were assessed using Raman micro-spectroscopy and high performance liquid chromatography (HPLC), respectively. Values of material parameters were obtained from finite element (FE) models by optimizing tissue-level creep and apparent-level stress-relaxation to experimental nanoindentation and unconfined compression testing values, respectively, utilizing the second order Prony series to depict viscoelasticity. FE simulations showed that tissue-level equilibrium elastic modulus (Eeq) increased with increasing crystallinity (r=0.730, p=.011) while at the apparent-level it increased with increasing hydroxylysyl pyridinoline content (r=0.718, p=.019). In addition, the normalized shear modulus g1 (r=-0.780, p=.005) decreased with increasing collagen ratio (amide III/CH2) at the tissue-level, but increased (r=0.696, p=.025) with increasing collagen ratio at the apparent-level. No significant relations were found between the measured or simulated viscoelastic parameters at the tissue- and apparent-levels nor were the parameters related to tissue elasticity determined with SAM. However, only Eeq, g2 and relaxation time τ1 from simulated viscoelastic values were statistically different between tissue- and apparent-levels (p<.01). These findings indicate that bone tissue viscoelasticity is affected by tissue composition but may not fully predict the macroscale viscoelasticity in human trabecular bone.

Attitudes towards clinical research among cancer trial participants and non-participants: an interview study using a Grounded Theory approach.

The attitudes of women patients with cancer were explored when they were invited to participate in one of three randomised trials that included chemotherapy at two university centres and a satellite centre. Fourteen patients participating in and 15 patients declining trials were interviewed. Analysis was based on the constant comparative method. Most patients voiced positive attitudes towards clinical research, believing that trials are necessary for further medical development, and most spontaneously argued that participation is a moral obligation. Most trial decliners, however, described a radical change in focus as they faced the actual personal choice. Almost no one got an impression of clinical equipoise between treatments in the trials, and most patients expressed discomfort with randomisation. A patient's choice to participate was mainly determined by whether the primary focus was on treatment effect or on adverse effects. Both knowledge about and feelings towards trials originated mostly from the media, although paradoxically the media were largely seen as untrustworthy. Mistrust was shown towards the pharmaceutical industry, and although most patients originally trusted that doctors primarily pursued the interest of patients, they did not trust the adequacy of doctors or industry in maintaining self-regulation. Thus, public control measures were judged to be essential.

Participating in a cancer clinical trial? The balancing of options in the loneliness of autonomy: a grounded theory interview study.

Cancer patients asked to participate in a randomised trial including chemotherapy at two university centres and a satellite centre were interviewed about perceptions and experiences (14 trial participating and 15 trial declining patients). The central phenomenon was a constant, cautious balancing of personal options searching for maximised effect, personal safety, trust, confidence and being cared for. Almost all developed a treatment preference and this was decisive for choices. Trial participants strongly wished to get the experimental treatment perceived as superior. They felt their freedom of choice being limited by randomisation. In contrast, trial decliners almost all focused on graver adverse effects related to the experimental treatment. A trusting and confident doctor-patient relationship was valued strongly. Yet, most breast cancer patients treated at the two large centres experienced a general lack of personal trust, confidence and being taken care of. The major reason was patients meeting too many physicians perceived as incompetent and unprepared. In contrast, the ovarian cancer patients treated at the satellite centre were content and satisfied with the main reason being the low number of physicians who were perceived as prepared, empathetic and knowledgeable. All patients expressed a feeling of "loneliness of autonomy" lacking sufficient knowledge and other resources to make educated choices.

Construction and characterization of a Lactococcus lactis strain deficient in intracellular ClpP and extracellular HtrA proteases.

A Lactococcus lactis strain deficient in both its major proteases, intracellular (ClpP) and extracellular (HtrA), was constructed and characterized. This strain, hereafter called clpP-htrA, could be obtained only by conjugation between a clpP donor strain and an htrA recipient strain in the NZ9000 context, allowing heterologous gene expression under the control of the NICE (nisin-controlled expression) system. The clpP-htrA double mutant showed both higher stress tolerance (e.g. high temperature and ethanol resistance) and higher viability than single clpP or htrA mutant strains. In addition, the secretion rate of two heterologous proteins (staphylococcal nuclease Nuc and Nuc-E7) was also higher in clpP-htrA than in the wild-type strain. This strain should be a useful host for high-level production and quality of stable heterologous proteins.

Attitudes towards clinical research amongst participants and nonparticipants.

OBJECTIVES: To investigate attitudes to clinical research amongst cancer trial participants and nonparticipants, and to compare results with those from previous studies amongst participants in noncancer trials. DESIGN: Trial participating respondents were given three questionnaires during the clinical trials. Respondents amongst patients declining randomization answered a single questionnaire. SETTING: Participants and nonparticipants in randomized clinical cancer trials. SUBJECTS: Forty-one participants and 47 nonparticipants in cancer trials. RESULTS: Altruistic motives of physicians to conduct medical research were highly rated. Attitudes towards clinical research were positive in all groups, with nonparticipant respondents being the least positive. Eight to nine tenths found scientific testing necessary before general health service implementation. Trial participants were, as compared with nonparticipating respondents, more positive towards both participation of self and others. Both personal and altruistic motives for participation were highly rated. Primary reasons for nonparticipation were fear of 'the unknown' and/or unease with randomization. Only a minority felt a moral problem created by declining trial participation. Respondents amongst noncancer participants were more satisfied with the information given than both cancer participants and cancer nonparticipants. Negative experiences in cancer participants generally dealt with frustration related to seeing too many physicians at check-up appointments. CONCLUSION: Attitudes towards clinical research are generally positive even in cancer nonparticipants. Both personal and altruistic motives for participation were highly rated. A fear of 'the unknown' and resentments towards randomization were primary reasons to renounce participation. Seeing too many physicians at check-up appointments seems to be an important factor for negative experiences in cancer trial participants.

Inflammatory bowel disease evaluated by low-field magnetic resonance imaging. Comparison with endoscopy, 99mTc-HMPAO leucocyte scintigraphy, conventional radiography and surgery.

BACKGROUND: To evaluate the use of low-field magnetic resonance imaging (MRI) in active inflammatory bowel disease (IBD). METHODS: MRI was executed in a consecutive cohort of 28 patients with Crohn disease (CD) and in 17 with ulcerative colitis (UC) prior to glucocorticoid treatment (1 mg prednisolone orally/kg body weight/day). MRI was repeated after 2-3 weeks (22 CD, 12 UC), and again after treatment completion or prior to surgery (18 CD, 6 UC). Five bowel segments were evaluated separately. MRIs were blindly evaluated by two observers, and findings compared with 39 leucocyte scintigraphies, 38 endoscopies, 15 double-contrast barium enemas, 66 small-bowel radiographic examinations and surgery in 23 patients. RESULTS: In CD, blinded evaluation revealed a kappa (kappa) of 0.84 (95% confidence interval (CI) 0.78-0.91). In UC, kappa was 0.66 (95% CI 0.55-0.78). Agreements regarding disease extension between MRI and other modalities in CD were found in 345 bowel segments out of 391 (88.2%) at risk, and in UC in 209/235 (88.9%). Colonic disease activity gradings by radiography and endoscopy correlated significantly with T2-signal intensity (SI(T2)) and increments in T1-signal intensity (%SI(T1)) in both diseases. Significant correlations between MRI indices of disease activity and CDAI in CD (MRI-SI(T2): P <0.0001: MRI% SI(T1): P=0.0008) and the Powell-Tuck index in UC (MRI% SI(T1): P=0.008) were found. CONCLUSIONS: With low interobserver variation and high concordance of findings with other examinations. low-field MRI seems a valuable modality in active IBD. In addition, MRI expressions of disease activity correlate to clinical, radiographic and endoscopic disease activity.

An open-labeled, randomized study comparing systemic interferon-alpha-2A and prednisolone enemas in the treatment of left-sided ulcerative colitis.

OBJECTIVE: The aim of this study was to compare the treatment efficacies of subcutaneous interferon-alpha-2A (IFN-alpha-2A) injections versus prednisolone enemas in active left-sided ulcerative colitis in an open-labeled, randomized study. METHODS: Sixteen ulcerative colitis patients received IFN-alpha-2A subcutaneously (dosage: first wk, 9 MIU three times weekly [t.i.w.]; second wk, 6 MIU t.i.w.; wk 3-12, 3 MIU t.i.w.), and 16 received prednisolone enemas for 30 days (100 ml once daily, 0.25 mg of prednisolone/ml). The Powell-Tuck Index, Inflammatory Bowel Disease Questionnaire (IBDQ) score, and rectal histological activities were assessed before and after treatment. Thirteen patients in the IFN-alpha-2A group and all 16 in the prednisolone enema group completed the treatment. RESULTS: IFN-alpha-2A treatment showed significant improvements in the Powell-Tuck Index (p = 0.0002), IBDQ score (p = 0.002), and rectal histological activity scores (p = 0.02). In the enema group, significant improvements were found in the Powell-Tuck Index (p = 0.0009), whereas no significant improvements were detected in the IBDQ scores (p = 0.055) or rectal histological scores (p = 0.052). There were no differences between scores of the two groups either before or after treatment. Only moderate side effects from the IFN-alpha-2A treatment were seen during the first 2-4 wk of treatment. CONCLUSION: IFN-alpha-2A treatment resulted in significant depression of the disease activity as reflected by the Powell-Tuck Index, IBDQ score, and histological disease activity scoring. The preliminary trial thus suggests that IFN-alpha-2A may be effective in the treatment of active left-sided ulcerative colitis. Larger, randomized trials are, however, warranted to confirm this finding, owing to possible type II errors in group comparisons.

Intra- and extracellular beta-galactosidases from Bifidobacterium bifidum and B. infantis: molecular cloning, heterologous expression, and comparative characterization.

Three beta-galactosidase genes from Bifidobacterium bifidum DSM20215 and one beta-galactosidase gene from Bifidobacterium infantis DSM20088 were isolated and characterized. The three B. bifidum beta-galactosidases exhibited a low degree of amino acid sequence similarity to each other and to previously published beta-galactosidases classified as family 2 glycosyl hydrolases. Likewise, the B. infantis beta-galactosidase was distantly related to enzymes classified as family 42 glycosyl hydrolases. One of the enzymes from B. bifidum, termed BIF3, is most probably an extracellular enzyme, since it contained a signal sequence which was cleaved off during heterologous expression of the enzyme in Escherichia coli. Other exceptional features of the BIF3 beta-galactosidase were (i) the monomeric structure of the active enzyme, comprising 1,752 amino acid residues (188 kDa) and (ii) the molecular organization into an N-terminal beta-galactosidase domain and a C-terminal galactose binding domain. The other two B. bifidum beta-galactosidases and the enzyme from B. infantis were multimeric, intracellular enzymes with molecular masses similar to typical family 2 and family 42 glycosyl hydrolases, respectively. Despite the differences in size, molecular composition, and amino acid sequence, all four beta-galactosidases were highly specific for hydrolysis of beta-D-galactosidic linkages, and all four enzymes were able to transgalactosylate with lactose as a substrate.

Analysis of the genetic switch and replication region of a P335-type bacteriophage with an obligate lytic lifestyle on Lactococcus lactis.

The DNA sequence of the replication module, part of the lysis module, and remnants of a lysogenic module from the lytic P335 species lactococcal bacteriophage phi31 was determined, and its regulatory elements were investigated. The identification of a characteristic genetic switch including two divergent promoters and two cognate repressor genes strongly indicates that phi31 was derived from a temperate bacteriophage. Regulation of the two early promoters was analyzed by primer extension and transcriptional promoter fusions to a lacLM reporter. The regulatory behavior of the promoter region differed significantly from the genetic responses of temperate Lactococcus lactis phages. The cro gene homologue regulates its own production and is an efficient repressor of cI gene expression. No detectable cI gene expression could be measured in the presence of cro. cI gene expression in the absence of cro exerted minor influences on the regulation of the two promoters within the genetic switch. Homology comparisons revealed a replication module which is most likely expressed from the promoter located upstream of the cro gene homologue. The replication module encoded genes with strong homology to helicases and primases found in several Streptococcus thermophilus phages. Downstream of the primase homologue, an AT-rich noncoding origin region was identified. The characteristics and location of this region and its ability to reduce the efficiency of plaquing of phi31 10(6)-fold when present at high copy number in trans provide evidence for identification of the phage origin of replication. Phage phi31 is an obligately lytic phage that was isolated from commercial dairy fermentation environments. Neither a phage attachment site nor an integrase gene, required to establish lysogeny, was identified, explaining its lytic lifestyle and suggesting its origin from a temperate phage ancestor. Several regions showing extensive DNA and protein homologies to different temperate phages of Lactococcus, Lactobacillus, and Streptococcus were also discovered, indicating the likely exchange of DNA cassettes through horizontal gene transfer in the dynamic ecological environment of dairy fermentations.

The development of TnNuc and its use for the isolation of novel secretion signals in Lactococcus lactis.

We have previously used Tn917 for the identification and characterization of regulated promoters from Lactococcus lactis [Israelsen et al., Appl. Environ. Microbiol. 61 (1995) 2540-2547]. We describe here the construction of a new Tn917-transposon derivative, termed TnNuc, which includes the Staphylococcus aureus nuclease gene (nuc) as a reporter for secretion. Transposition of TnNuc into the L. lactis chromosome allows the generation of fusions in-frame with the nuc gene. TnNuc includes also lacZ, a reporter used for identification of relevant clones from the library, i.e. clones with Lac+ phenotype result from transposition of TnNuc into a functional gene on the L. lactis chromosome. The presence of a functional signal sequence at the upstream flanking region of the left repeat of the transposed element results in the detection of nuclease activity using a sensitive plate assay. TnNuc was used for the identification of novel secretion signals from L. lactis. The sequences identified included known and unknown lactococcal-secreted proteins containing either a signal peptidase-I or -II recognition sequence. In one case, the gene identified codes for a transmembrane protein. The sequences identified were used to study functionality when located in a plasmid under the control of the pH and growth phase-dependent promoter P170 [Madsen et al., Mol. Microbiol. 32 (1999) 75-87]. In all cases, concurrent secretion of nuclease was observed during induction of P170 in a fermentor.

Established and emerging biological activity markers of inflammatory bowel disease.

Assessment of disease activity in inflammatory bowel disease (IBD), i.e., ulcerative colitis (UC) and Crohn's disease (CD), is done using clinical parameters and various biological disease markers. Ideally, a disease marker must: be able to identify individuals at risk of a given disorder, be disease specific, mirror the disease activity and, finally, be easily applicable for routine clinical purposes. However, no such disease markers have yet been identified for IBD. In this article, classical disease markers including erythrocyte sedimentation rate, acute phase proteins (especially orosomucoid and CRP), leukocyte and platelet counts, albumin, neopterin, and beta2-microglobulin will be reviewed together with emerging disease markers such as antibodies of the ANCA/ASCA type, cytokines (e.g., IL-1, IL-2Ralpha, IL-6, IL-8, TNF-alpha, and TNF-alpha receptors) and with various adhesion molecules. It is concluded that none of the pertinent laboratory surrogate markers of disease activity in IBD are specific or sensitive enough to replace basic clinical observation such as the number of daily bowel movements, general well-being, and other parameters in parallel. Further studies are highly warranted to identify and assess the clinical importance and applicability of new laboratory markers for the diagnosis or the disease activity of IBD.

Ethical aspects of clinical trials: the attitudes of participants in two non-cancer trials.

OBJECTIVES: To investigate attitudes to clinical trials in non-cancer trial participants. DESIGN: Questionnaires at entry, during, and after participation in a clinical study. SETTING: Participants in: (i) ROC: a clinical study comparing systemic interferon-alpha-2A treatment vs. prednisolone enemas in ulcerative colitis; and (ii) MRCRUC: a clinical study investigating low-field magnetic resonance imaging as a new modality for the evaluation of patients with inflammatory bowel disease. SUBJECTS: Thirty-two patients in ROC and 47 patients in MRCRUC. OUTCOME MEASURES: Attitudes towards different aspects of clinical research. RESULTS: The majority found scientific testing of clinical methods necessary, having positive attitudes towards both participation by themselves and others. The creation of a personal moral problem by denying participation was rejected by a large majority, and still both personal and altruistic motives for participation were highly rated. An important motive for accepting inclusion was the expectation of being 'a special patient' during the trial. The presence of research ethics committees controlling clinical research had a significant positive impact on decisions to participate, and drawing lots and blinding were found problematic by only a minority. Patients valued their satisfaction with participation in the trials highly, and would almost all accept a request to participate in future trials. The most important reason for this was a feeling of receiving better care and information than expected outside a trial setting, primarily determined by the patients seeing only one physician during the trials. A pronounced wish to obtain follow-up information was expressed. CONCLUSION: Attitudes towards medical research are positive with both altruistic and nonaltruistic motives for participation. Expectations of being treated as 'a special patient' in the trial were important in accepting to participate. Seeing the same physician at control visits was an important factor for satisfaction with participation.

The extent of written trial information: preferences among potential and actual trial subjects.

AIM: To investigate the preferred extent of written information in clinical trials among potential and actual trial participants. MATERIALS AND METHODS: Questionnaire survey among citizens of Copenhagen County (PUB, N=508), patients attending an out-patient clinic (OPC, N=200), and finally among participants in two clinical trials (ROC, N=32; MRCRUC, N=47--see Abbreviations). Questions concerned attitudes to and preferences towards a relatively short ("short form") and a more detailed information form ("long form") about a hypothetical, but realistic trial. RESULTS: Approximately 1/8 of the respondents in PUB were satisfied with the "short form", whereas this was the case for approximately 1/6 of outpatients and 1/5 of actual trial participants. Regarding the "long form" approximately three quarters of respondents in all groups were satisfied. Outpatients as a whole were satisfied to a larger extent that respondents from the PUB trial concerning the "short form" (p=0.04). The "long form" was preferred by a little less than 4/5 of respondents in all groups. CONCLUSION: Written information to trial subjects should be detailed, as a majority of both potential and actual research participants prefers this, given the choice between two information forms of different extent on the same trial.

Biochemical and ultrastructural changes in rabbit sclera after treatment with 7-methylxanthine, theobromine, acetazolamide, or L-ornithine.

AIMS: To examine a possible effect of 7-methylxanthine, theobromine, acetazolamide, or L-ornithine on the ultrastructure and biochemical composition of rabbit sclera. METHODS: Groups of pigmented rabbits, six in each group, were dosed during 10 weeks with one of the substances under investigation, and one untreated group was the control. Samples of anterior and posterior sclera were taken for determination of hydroxyproline, hydroxylysine, proline, proteoglycans, uronic acids and dermatan sulphate, chondroitin sulphate, and hyaluronic acid. Sections were examined with electron microscopy, and the diameter of the individual collagen fibrils was measured. RESULTS: Treatment with theobromine produced a significant increase in the contents of hydroxylysine, hydroxyproline, and proline in both anterior and posterior sclera, while 7-methylxanthine increased the contents of hydroxyproline and proline selectively in posterior sclera. Acetazolamide, on the other hand, significantly decreased the contents of hydroxyproline and proline in samples from anterior sclera. Uronic acids in both anterior and posterior sclera were significantly reduced by treatment with 7-methylxanthine, and L-ornithine significantly reduced uronic acids in posterior sclera. An inverse correlation between contents of hydroxyproline and uronic acids was found. The mean diameter of collagen fibrils was significantly higher in the posterior sclera from rabbits treated with 7-methylxanthine or theobromine, and significantly lower in rabbits treated with acetazolamide or L-ornithine compared with controls. In the anterior sclera, fibril diameter was significantly reduced in all treatment groups compared with controls. A positive, significant correlation between fibril diameter and content of hydroxyproline and proline was found in posterior sclera. CONCLUSION: 7-Methylxanthine, a metabolite of caffeine, increases collagen concentration and the diameter of collagen fibrils in the posterior sclera, and may be useful for treatment or prevention of conditions associated with low level and/or inferior quality of scleral collagen, such as axial myopia, chronic open angle glaucoma, and possibly neovascular age related macular degeneration. The apparent loss of collagen induced by chronic treatment with acetazolamide should be taken into consideration as a potentially harmful side effect. These results may indicate that scleral biochemistry and ultrastructure are influenced by the retinal pigment epithelium. One possible explanation is that the scleral fibroblasts which produce the collagen are sensitive to changes in the physiological electric field created by the retinal pigment epithelium.

[How detailed information and how long consideration time do the potential trial subjects want?]. / Hvor udførlig information og hvor lang betaenkningstid ønsker potentielle forsøgspersoner?

Questionnaires were sent to 508 citizens in Copenhagen county and given to 200 patients attending two out-patient clinics. Questions concerned attitudes and preferences towards either a short or a more detailed information form about an invented trial, and preferences regarding required time for reflection before giving informed consent. One sixth of responders were satisfied with the short form, while about three quarters preferred the long form. Three quarters of the non-hospitalized citizens and the patients from one of the out-patient clinics required at least 24 hours before answering about consent. Among responders in the other outpatient clinic half of the patients only required 15 minutes, or stated that they could answer at once. We conclude that written information to trial patients should be detailed, as a majority of potential research participants prefer this. At least 24 hours should be given before an informed consent is obtained.

Evaluation of treatment response in active Crohn's disease by low-field magnetic resonance imaging.

BACKGROUND: To evaluate low-field magnetic resonance imaging (MRI) in detecting therapeutic response in active Crohn's disease during treatment with systemic steroids. METHODS: Eight patients with active Crohn's disease were examined before and during treatment with systemic steroids (1 mg/kg/day) using low-field MRI (0.1 T) in transverse and coronal planes before and after an intravenously administered bolus of gadodiamide. Five healthy persons were once examined in the same way. MRI images were evaluated without knowledge of diagnosis, treatment, or findings of endoscopy, conventional radiography, and surgery. Proximal and mid small bowel, terminal ileum, right-sided colon, transverse colon, and left-sided colon were evaluated separately. RESULTS: Statistically significant differences were shown for both signal intensity on T2- (SIT2) and increment in signal intensity on T1-weighted images after contrast (%SIT1) when comparing diseased bowel segments with both nondiseased bowel segments (SIT2: p = 0.0001; %SIT1: p = 0.0009) and segments from the control group (SIT2: p < 0.00005; %SIT1: p < 0.00005). In 53 of 56 bowel segments evaluated (95%), agreement was found between findings by MRI, conventional radiography, endoscopy and/or surgery regarding disease extension. Extension was underestimated in two patients. All bowel segments in the control subjects were evaluated to be normal on MRI. Significant correlation was found between both SIT1 (p < 0.0025) and %SIT1 (p < 0.025) versus endoscopic activity gradings. During treatment, significant decrements of both SIT2 (p < 0.00005), %SIT1 (p = 0.002), and bowel wall thickness (p = 0.03) were found. CONCLUSIONS: Low-field MRI seems to be a promising noninvasive method in the evaluation of response regarding both disease extension and activity in Crohn's disease during treatment with systemic steroids.

Molecular characterization of the pH-inducible and growth phase-dependent promoter P170 of Lactococcus lactis.

In a previous study, we described the use of transposon Tn917-LTV1 for identification of environmentally regulated promoters in Lactococcus lactis. Here, we report the molecular analysis of one of these promoters, P170, that is upregulated at low pH during the transition to stationary phase. The minimal DNA region required for both promoter activity and pH regulation was mapped to a 51 bp fragment located 7 bp upstream of the transcriptional start site. This fragment lacked the consensus -35 promoter region, but it contained an 'extended' -10 promoter region. When a 28 bp segment, containing the consensus -35 region and 22 bp upstream of this in a constitutive promoter, was replaced with the corresponding sequence of P170, the hybrid promoter became regulated by pH and growth phase. This demonstrates that the P170 segment contains a cis-acting sequence involved in the control of promoter regulation. Transcriptional analysis showed that P170 is responsible for the transcription of a monocistronic gene orfX encoding a polypeptide homologous to a hypothetical protein from Bacillus subtilis. Analysis of total RNA from L. lactis grown at constant pH confirmed that transcription from P170 was induced between pH 6.5 and pH 6.0, but only when the culture entered stationary phase. Deletion analysis and chemical mutagenesis of P170 defined a specific region within the untranslated mRNA leader that is able to modulate the expression level directed by the P170 promoter. Deletion of a 72 bp HaeIII fragment from this leader region resulted in a 150- to 200-fold increase in the level of gene expression, without affecting the regulation. The functionality was confirmed by introducing this modulating element downstream of other lactococcal promoters.

Fistula in ano: evaluation with low-field magnetic resonance imaging (0.1 T).

BACKGROUND: Patients suspected of having perianal suppurative disease often undergo a combination of several potentially painful, invasive procedures to establish or rule out the diagnosis. To evaluate the accuracy of low-field magnetic resonance imaging (MRI) in distinguishing patients with active anal fistulae and patients with no active fistulation we performed a retrospective study. METHODS: Fifty-six patients suspected of having anal fistulation were evaluated in the surgical outpatient clinic. Patients were examined with low-field MRI (0.1 T; gradient echo technique, TR/TE 1,500/40 and TR/TE 115/25, +/- gadodiamide (0.1 mM/kg intravenously)) in both coronal and axial planes, using a body quadrature coil. Altogether 71 MRIs were performed. In selected patients evaluation included endoanal ultrasonography, fistulography, and/or surgery. On the basis of the combined results of all available follow-up data for 6 months after the MRI, patients were placed in groups either having active fistulation or not. RESULTS: MRI findings agreed with the combined findings of other examinations in 54 patients. Active or possibly active fistulae were found in 36 cases, whereas 33 patients showed no active fistulae. The kappa value is 0.944 (95% confidence limits, 0.866-1.021). In two patients the MRI findings disagreed with the combined findings of the other modalities. CONCLUSION: The use of low-field MRI of the pelvic region in the investigation of suspected perianal fistulae is a feasible, reliable, and painless examination. MRI should be considered in patients with suspected complex anal fistulae. Future prospective studies are warranted.

[Healing of venous leg ulcers. A randomized prospective study of a long-stretch versus short-stretch compression bandage]. / Heling af venøse bensår. En randomiseret prospektiv undersøgelse af en langstraek- versus en kortstraek-kompressionsbandage.

The aim of the study was to compare the efficacy of two types of compression bandage with different degrees of elasticity on healing of venous leg ulcers. Forty-three patients with venous leg ulcers were included and blindly randomized to treatment with one of the two types of bandage aiming at a sub-bandage pressure in the ankle area of 40 mmHg. Forty legs were evaluated. Healed ulcers after 12 months were observed in 71% of the long-stretch group and in 30% of the short-stretch group (p = 0.06). Using life-table analysis the predicted healing rate in the long-stretch group after 12 months was 81% and for the short-stretch group 31% (p = 0.03). The mean of relative ulcer areas at 12 months was 0.25 for the long-stretch group and 0.95 for the short-stretch group (p = 0.01). The present study appears to indicate a positive influence of the elasticity of a compression bandage applied with a sub-bandage pressure around 40 mmHg in the ankle area on venous ulcer healing.

Active Crohn's disease and ulcerative colitis evaluated by low-field magnetic resonance imaging.

BACKGROUND: Our aim was to evaluate low-field magnetic resonance imaging (MRI) in the assessment of disease extension and activity in inflammatory bowel disease. METHODS: Nineteen patients with Crohn's disease (CD), 8 with ulcerative colitis (UC), and 5 healthy controls (HC) were examined using MRI (0.1 T) before and after intravenously administered gadodiamide and glucagon. MRI images were evaluated in a blinded fashion and compared with findings at endoscopy, double-contrast barium enema, small-bowel follow-through, and surgery. RESULTS: Comparisons of diseased with both non-diseased bowel segments and segments from HC showed significant differences for both CD and UC with regard to signal intensity on T2-weighted (SI(T2)) images and post-contrast increment of signal intensity on T1-weighted images (%SI(T1). Agreements with regard to disease extension in CD between MRI and other examinations were 97%, underestimating the extension in two patients. For SI(T2) in CD a cut-off value of 1.0 showed a predictive value of a positive finding (PVpos) = 1.0 and a predictive value of a negative finding (PVneg) = 0.96. For %SI(T1) in CD a cut-off value of 15.0% showed values of PVpos = 0.95 and PVneg = 0.92. Agreements between MRI and conventional methods (disease extension) in UC was 87.5%. Extension was underestimated in two patients and overestimated in two patients as compared with barium enemas. Values of PVpos were 1.0 (SI(T2) >1.0) and 1.0 (%SI(T1) >15.0%), respectively, with corresponding values of PVneg being 0.94 and 0.94. CONCLUSION: Low-field MRI seems a promising non-invasive, non-radiating method in the evaluation of inflammatory bowel disease.