An analysis of the level of evidence behind treatments recommended by the Danish Medicines Council

OBJECTIVES

We aimed to investigate the quality of evidence and the expected added clinical value of treatments recommended by the Danish Medicines Council (DMC).

STUDY DESIGN

This was an observational study.

METHODS

The DMC prepares reports on drugs considered for possible new standard treatments in Danish hospitals. These reports evaluate the available evidence on efficacy and safety. The quality of evidence is systematically rated by the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) criteria, and estimates of added clinical value are presented. The recommendations take into account expected economic implications of new treatments. The publicly available reports up until December 29, 2021, were downloaded from the DMC Web page. Reports on drugs marked "recommended" were included. Data on quality of evidence, expected clinical value, and economic implications were imputed in a Microsoft Excel spreadsheet.

RESULTS

Seventy-nine reports were included in the analysis. In 79% of these, the quality of evidence was rated low (24%) or very low (55%), whereas no recommendations were based on evidence rated as high quality. Three (5%) of recommended treatments were expected to add large clinical value.

CONCLUSIONS

Most recommendations by the DMC are based on evidence formally rated as low or very low quality by GRADE, and no recommendations were based on evidence rated as high quality. The added clinical value of the treatments was often not documented and rarely large. Continued attention to improve the clinical evidence behind national recommendations is necessary.

Outcomes and Long-Term Effects of COVID-19 in Patients with Inflammatory Bowel Diseases - A Danish Prospective Population-Based Cohort Study with Individual-Level Data

BACKGROUND AND AIMS

The health consequences of coronavirus disease 2019 [COVID-19] among patients with ulcerative colitis [UC] and Crohn's disease [CD] remain largely unknown. We aimed to investigate the outcomes and long-term effects of COVID-19 in patients with UC or CD.

METHODS

We conducted a prospective, population-based study covering all Danish patients with CD or UC and confirmed COVID-19 between January 28, 2020 and April 1, 2021, through medical records and questionnaires.

RESULTS

All 319 patients with UC and 197 patients with CD who developed COVID-19 in Denmark were included in this study and compared with the Danish background population with COVID-19 [N = 230 087]. A significantly higher risk of COVID-19-related hospitalization was observed among patients with UC (N = 46 [14.4%], relative risk [RR] = 2.49 [95% confidence interval, CI, 1.91-3.26]) and CD (N = 24 [12.2%], RR = 2.11 [95% CI 1.45-3.07]) as compared with the background population (N = 13 306 [5.8%]). A similar pattern was observed for admission to intensive care (UC: N = 8 [2.51%], RR = 27.88 [95% CI 13.88-56.00]; CD: N = 3 [1.52%], RR = 16.92 [95% CI 5.46-52.46]). After a median of 5.1 months (interquartile range [IQR] 4.5-7.9), 58 [42.3%] and 39 [45.9%] patients with UC and CD, respectively, reported persisting symptoms which were independently associated with discontinuation of immunosuppressive therapies during COVID-19 (odds ratio [OR] = 1.50 [95% CI 1.07-10.22], p = 0.01) and severe COVID-19 (OR = 2.76 [95% CI 1.05-3.90], p = 0.04), but not with age or presence of comorbidities.

CONCLUSION

In this population-based study of 516 patients with IBD and COVID-19, 13.6% needed hospitalization and 2.1% required intensive care. Furthermore, sequelae were frequent, affecting 43.7% of COVID-19-infected patients. These findings might have implications for planning the healthcare of patients in the post-COVID-19 era.

Association Between the Clinical, Biochemical, and Endoscopic Activity of Inflammatory Bowel Diseases and Severity and Long-term Outcomes of Coronavirus Disease 2019-A Population-based Study

This brief report investigated the impact of clinical, biochemical, and endoscopic activity of IBD on the severity and long-term outcomes of COVID-19 in a prospective population-based cohort. The study did not identify any association between IBD activity and COVID-19 outcomes.

Long-Term Effects of a Web-Based Low-FODMAP Diet Versus Probiotic Treatment for Irritable Bowel Syndrome, Including Shotgun Analyses of Microbiota: Randomized, Double-Crossover Clinical Trial

BACKGROUND

The long-term management of irritable bowel syndrome (IBS) poses many challenges. In short-term studies, eHealth interventions have been demonstrated to be safe and practical for at-home monitoring of the effects of probiotic treatments and a diet low in fermentable oligosaccharides, disaccharides, monosaccharides, and polyols (FODMAPs). IBS has been linked to alterations in the microbiota.

OBJECTIVE

The aim of this study was to determine whether a web-based low-FODMAP diet (LFD) intervention and probiotic treatment were equally good at reducing IBS symptoms, and whether the response to treatments could be explained by patients' microbiota.

METHODS

Adult IBS patients were enrolled in an open-label, randomized crossover trial (for nonresponders) with 1 year of follow-up using the web application IBS Constant Care (IBS CC). Patients were recruited from the outpatient clinic at the Department of Gastroenterology, North Zealand University Hospital, Denmark. Patients received either VSL#3 for 4 weeks (2 × 450 billion colony-forming units per day) or were placed on an LFD for 4 weeks. Patients responding to the LFD were reintroduced to foods high in FODMAPs, and probiotic responders received treatments whenever they experienced a flare-up of symptoms. Treatment response and symptom flare-ups were defined as a reduction or increase, respectively, of at least 50 points on the IBS Severity Scoring System (IBS-SSS). Web-based ward rounds were performed daily by the study investigator. Fecal microbiota were analyzed by shotgun metagenomic sequencing (at least 10 million 2 × 100 bp paired-end sequencing reads per sample).

RESULTS

A total of 34 IBS patients without comorbidities and 6 healthy controls were enrolled in the study. Taken from participating subjects, 180 fecal samples were analyzed for their microbiota composition. Out of 21 IBS patients, 12 (57%) responded to the LFD and 8 (38%) completed the reintroduction of FODMAPs. Out of 21 patients, 13 (62%) responded to their first treatment of VSL#3 and 7 (33%) responded to multiple VSL#3 treatments. A median of 3 (IQR 2.25-3.75) probiotic treatments were needed for sustained symptom control. LFD responders were reintroduced to a median of 14.50 (IQR 7.25-21.75) high-FODMAP items. No significant difference in the median reduction of IBS-SSS for LFD versus probiotic responders was observed, where for LFD it was -126.50 (IQR -196.75 to -76.75) and for VSL#3 it was -130.00 (IQR -211.00 to -70.50; P>.99). Responses to either of the two treatments were not able to be predicted using patients' microbiota.

CONCLUSIONS

The web-based LFD intervention and probiotic treatment were equally efficacious in managing IBS symptoms. The response to treatments could not be explained by the composition of the microbiota. The IBS CC web application was shown to be practical, safe, and useful for clinical decision making in the long-term management of IBS. Although this study was underpowered, findings from this study warrant further research in a larger sample of patients with IBS to confirm these long-term outcomes.

TRIAL REGISTRATION

ClinicalTrials.gov NCT03586622; https://clinicaltrials.gov/ct2/show/NCT03586622.

Costs of electronic health vs. standard care management of inflammatory bowel disease across three years of follow-up-a Danish register-based study

BACKGROUND

Costs of using eHealth in inflammatory bowel disease (IBD) management has only been assessed for short follow-up periods. The primary aim was to compare the direct costs of eHealth (cases) relative to standard care (matched controls) for IBD during three years of follow-up.

METHODS

The study design was a retrospective, registry-based follow-up study of patients diagnosed with IBD two years prior, and three years subsequent, to their enrolment in eHealth. Cases were matched 1:4 with controls receiving standard care based on diagnosis, gender, biologics (yes/no) and age (+/- 5 years).

RESULTS

We identified 116 cases (76 (66%) with ulcerative colitis (UC) and 40 (34%) with Crohn's disease (CD)) and matched them with 433 controls. IBD-related outpatient costs were only significantly higher for cases in the year of their inclusion in eHealth (€2,949 vs. €1,621 per patient, p =.01). Mean IBD-related admission costs tended to fall after enrolment in eHealth, with mean admission costs per patient at year 3 of follow-up of €74 for cases and €383 for controls (p = .02). Linear extrapolation of the reduction in costs beyond year 3 after enrolment in eHealth revealed that eHealth would be cost neutral or saving, relative to standard care, from year 4.

CONCLUSION

IBD-related outpatient costs in both groups were similar and only significantly higher for cases in the year of their enrolment in eHealth, with admission costs typically falling after a patient's inclusion in eHealth. Estimation revealed eHealth to be cost neutral or saving from year 4.

Prevalence and Outcomes of COVID-19 Among Patients With Inflammatory Bowel Disease-A Danish Prospective Population-based Cohort Study

BACKGROUND AND AIMS

As no population-based study has investigated the susceptibility and disease course of COVID-19 among patients with inflammatory bowel diseases [IBD], we aimed to investigate this topic in a population-based setting.

METHODS

Two cohorts were investigated. First, a nationwide cohort of all IBD patients diagnosed with COVID-19 was prospectively followed to investigate the disease courses of both diseases. Second, within a population-based cohort of 2.6 million Danish citizens, we identified all individuals tested for SARS-CoV-2 to determine the occurrence of COVID-19 among patients with and without IBD and other immune-mediated inflammatory diseases [IMIDs].

RESULTS

Between January 28, 2020 and June 2, 2020, a total of 76 IBD patients with COVID-19 were identified in the national cohort and prospectively followed for 35 days (interquartile range [IQR]: 25-51). A large proportion [n = 19: 25%] required a COVID-19-related hospitalisation for 7 days [IQR: 2-8.5] which was associated with being 65 years or older (odds ratio [OR] = 23].80, 95% confidence interval [CI] 6.32-89.63, p <0.01) and presence of any non-IMID comorbidity [OR = 8.12, 95% CI 2.55-25.87, p <0.01], but not use of immunomodulators [p = 0.52] or biologic therapies [p = 0.14]. In the population-based study, 8476 of 231 601 [3.7%] residents tested positive for SARS-CoV-2; however, the occurrence was significantly lower among patients with IBD [62 of the 2486 patients = 2.5%, p <0.01] and other IMIDs [531 of 16 492 patients = 3.2%, p <0.01] as compared with patients without IMIDs.

CONCLUSIONS

Patients with IMIDs, including IBD, had a significantly lower susceptibility to COVID-19 than patients without IMIDs, and neither immunosuppressive therapies nor IBD activity were associated with the disease course of COVID-19.

[Telemedicine applications for monitoring inflammatory bowel disease and irritable bowel syndrome]

Inflammatory bowel disease (IBD) and irritable bowel syndrome (IBS) are chronic relapsing diseases with major impact on the patients' everyday life, and increasing incidences affect the burden on the healthcare system. This review summarises the evidence of telemedicine applications (TA) to patients suffering from IBD and IBS in Denmark and abroad. TA have been shown to: reduce time-to-remission, increase quality of life and medical adherence, and reduce hospital admissions and outpatient visits in adult patients with IBD. In paediatric patients with IBD, TA have been shown to reduce: the need of outpatient visits, the number of school absences, and the symptom scores.

Pf1 filamentous phage as an alignment tool for generating local and global structural information in nucleic acids

Abstract Pf1 filamentous phage represent a simple versatile method for generating partially ordered macromolecules in solution. The phage allow tunable degrees of alignment of macromolecules under a wide range of temperature and solvent conditions. The negatively charged phage are ideal for aligning negatively charged nucleic acids and these phage-nucleic acid solutions are stable indefinitely. We have used Pf1 phage to align various DNA and RNA molecules in solution for measurement of dipolar coupling interactions. These dipolar couplings can be used to improve the local structure of nucleic acids. More importantly they also contain information on the global structure, such as DNA bending, which presently cannot be obtained by standard NMR methods. The principles involved in using Pf1 phage to generate solutions of partially order macromolecules will be discussed. The use of (1)H-(1)H, (1)H-(13)C and (1)H-(15)N dipolar couplings for generating angle constraints for structure refinement of nucleic acids will also be discussed.

Fast and slow dynamics in a discotic liquid crystal with regions of columnar order and disorder

Aromatic disk-shaped molecules tend to self-organize into a herringbone packing where the disks are inclined at angles ±θ with respect to the axis of the column. In discotic liquid crystals this can introduce defects between stacks of limited length. In a C(3)-symmetric hexa-peri-hexabenzocoronene, solid-state NMR, x-ray scattering, and rheology identifies such a packing with θ=43° and stacks of about seven disks. Disordered regions containing defects fill the space in between the ordered stacks. Biaxial intra- and intercolumnar dynamics differing by eight decades are identified.

Reciprocal signaling between spiral ganglion neurons and Schwann cells involves neuregulin and neurotrophins

To investigate the role of neuron-glial cell interactions in the auditory nerve, we asked whether spiral ganglion neurons (SGNs) express neuregulin and whether neuregulin regulates proliferation and/or neurotrophin expression in spiral ganglion Schwann cells (SGSCs). Using immunocytochemistry, we found that type I and type II SGNs express neuregulin in vivo and in vitro. Cultured SGSCs express the neuregulin receptors ErbB2 and ErbB3, but not ErbB4. Neuregulin activates ErbB2 and ErbB3 in cultured SGSCs, evidenced by increased tyrosine phosphorylation of the receptors following neuregulin treatment. Neuregulin treatment increased the proliferation rate of cultured SGSCs by 2.5-fold. Fibroblast growth factor-2 (FGF-2) and transforming growth factor beta (TGF-beta) also increased SGSC proliferation. The mitogenic effect of neuregulin and FGF-2 was blocked by inhibition of mitogen-activated protein kinase signaling but not by inhibition of phosphatidylinositol-3'-OH kinase. Using RT-PCR, we found that cultured SGSCs express neurotrophins, including brain-derived neurotrophic factor and neurotrophin-3 (NT-3), raising the possibility that SGSCs contribute to the trophic support of SGNs. Treatment with neither neuregulin nor TGF-beta increased neurotrophin expression in cultured SGSCs, as had been observed in developing sympathetic ganglia, but appeared to negatively regulate NT-3 expression. Thus, neuregulin and neurotrophins may mediate reciprocal neuron-glial interactions in the auditory nerve.

BDNF synthesis in spiral ganglion neurons is constitutive and CREB-dependent

Brain-derived neurotrophic factor (BDNF), which supports spiral ganglion neuron (SGN) survival in vivo and in vitro, is synthesized by SGNs. The BDNF gene generates multiple different transcripts, each from its own promoter region. Using reverse transcriptase-polymerase chain reaction (RT-PCR), we find that SGNs express only the downstream transcripts III and IV in vivo and in vitro. Using RT-PCR assays of BDNF transcripts and transfection of BDNF promoter-reporter constructs, we tested the hypothesis, originally derived from studies of cortical neurons, that depolarization induces BDNF expression via a signaling pathway that includes Ca2+/calmodulin-dependent kinases (CaMKs) and the transcription factor, Ca2+/cyclic AMP response element binding protein (CREB). In contrast, we found that in SGNs in vivo BDNF expression is constitutive and is not increased by electrical activation. Similarly, BDNF expression in vitro is not increased by stimuli that activate CREB, including depolarization, cAMP, or transfection of activated CaMK mutants. However, transfection of dominant-negative CREB mutants did abrogate gene expression driven by BDNF promoters III and IV, indicating that CREB is necessary for constitutive BDNF expression. Thus, BDNF synthesis within SGNs makes possible an autocrine or paracrine mechanism that can contribute to support SGN survival but SGNs are distinctive in that this mechanism is constitutive and not activity-regulated.

Multiple distinct signal pathways, including an autocrine neurotrophic mechanism, contribute to the survival-promoting effect of depolarization on spiral ganglion neurons in vitro

We have shown previously that BDNF, neurotrophin-3 (NT-3), chlorphenylthio-cAMP (cpt-cAMP) (a permeant cAMP analog), and membrane depolarization promote spiral ganglion neuron (SGN) survival in vitro in an additive manner, depolarization having the greatest efficacy. Expression of both BDNF and of NT-3 is detectable in cultured SGNs after plating in either depolarizing or nondepolarizing medium. These neurotrophins promote survival by an autocrine mechanism; TrkB-IgG or TrkC-IgG, which block neurotrophin binding to, respectively, TrkB and TrkC, partially inhibit the trophic effect of depolarization. The mitogen-activated protein kinase kinase inhibitor PD98059 and the phosphatidylinositol-3-OH kinase inhibitor LY294002 both abolish trophic support by neurotrophins but only partially inhibit support by depolarization. Inhibition by these compounds is not additive with inhibition by Trk-IgGs. The cAMP antagonist Rp-adenosine-3',5'-cyclic-phosphorothioate (Rp-cAMPS) abolishes survival attributable to cpt-cAMP but has no effect on that attributable to neurotrophins, nor do inhibitors of neurotrophin-dependent survival affect survival attributable to cpt-cAMP. However, Rp-cAMPS does partially inhibit depolarization-dependent survival, an inhibition that is additive with that by Trk-IgGs, PD98059, or LY294002. Moreover, Rp-cAMPS prevents depolarization-dependent survival of PC12 cells maintained in subthreshold levels of NGF. Inhibition of Ca(2+)/calmodulin-dependent protein kinases (CaMKs) with KN-62 reduces SGN survival independently of Rp-cAMPS, Trk-IgGs, and LY294002 and additively with them. Combined inhibition of Trk, cAMP, and CaMK signaling prevents depolarization-dependent survival. Thus, survival of SGNs under depolarizing conditions involves additivity among a depolarization-independent autocrine pathway, a cAMP-dependent pathway, and a CaMK-dependent pathway.

High-performance liquid chromatography purification of homogenous-length RNA produced by trans cleavage with a hammerhead ribozyme

An improved method is presented for the preparation of milligram quantities of homogenous-length RNAs suitable for nuclear magnetic resonance or X-ray crystallographic structural studies. Heterogeneous-length RNA transcripts are processed with a hammerhead ribozyme to yield homogenous-length products that are then readily purified by anion exchange high-performance liquid chromatography. This procedure eliminates the need for denaturing polyacrylamide gel electrophoresis, which is the most laborious step in the standard procedure for large-scale production of RNA by in vitro transcription. The hammerhead processing of the heterogeneous-length RNA transcripts also substantially improves the overall yield and purity of the desired RNA product.

Identification and characterization of a novel high affinity metal-binding site in the hammerhead ribozyme

A novel metal-binding site has been identified in the hammerhead ribozyme by 31P NMR. The metal-binding site is associated with the A13 phosphate in the catalytic core of the hammerhead ribozyme and is distinct from any previously identified metal-binding sites. 31P NMR spectroscopy was used to measure the metal-binding affinity for this site and leads to an apparent dissociation constant of 250-570 microM at 25 degrees C for binding of a single Mg2+ ion. The NMR data also show evidence of a structural change at this site upon metal binding and these results are compared with previous data on metal-induced structural changes in the core of the hammerhead ribozyme. These NMR data were combined with the X-ray structure of the hammerhead ribozyme (Pley HW, Flaherty KM, McKay DB. 1994. Nature 372:68-74) to model RNA ligands involved in binding the metal at this A13 site. In this model, the A13 metal-binding site is structurally similar to the previously identified A(g) metal-binding site and illustrates the symmetrical nature of the tandem G x A base pairs in domain 2 of the hammerhead ribozyme. These results demonstrate that 31P NMR represents an important method for both identification and characterization of metal-binding sites in nucleic acids.

In situ T cell responses against melanoma comprise high numbers of locally expanded T cell clonotypes

It is well established that melanoma cells express Ags that are recognized by autologous T cells in vitro. Tumor-infiltrating lymphocytes in situ comprise clonotypic T cells, suggesting that their expansion is driven by Ag stimulation. Still, little is known about the detailed characteristics of the in situ T cell response. In the present study, we scrutinized this response by analyzing multiple metastatic lesions for the presence of clonotypic T cells. This approach was chosen to distinguish whether the clonal T cell expansion occurs as a systemic or localized phenomenon. TCR clonotype mapping of six s.c. metastases from two patients revealed the presence of multiple (from 40 to >60) clonotypic T cells in all lesions. Clonotypic T cells were present in TCR beta-variable regions expressed both at high and low levels. Comparison of the T cell clonotypes present in different lesions from individual patients demonstrated that, in general, clonotypes were exclusively detected in a single lesion. Hence, anti-melanoma T cell responses are much more heterogeneous than previously anticipated and accommodate a predominance of strictly localized T cell clonotypes.

An examination of coaxial stacking of helical stems in a pseudoknot motif: the gene 32 messenger RNA pseudoknot of bacteriophage T2

The RNA pseudoknot located at the 5' end of the gene 32 messenger RNA of bacteriophage T2 contains two A-form helical stems connected by two loops, in an H-type pseudoknot topology. A combination of multidimensional NMR methods and isotope labeling were used to investigate the pseudoknot structure, resulting in a more detailed structural model than provided by earlier homonuclear NMR studies. Of particular significance, the interface between the stacked helical stems within the pseudoknot motif is described in detail. The two stems are stacked in a coaxial manner, with an approximately 18 degrees rotation of stem1 relative to stem2 about an axis that is parallel to the helical axis. This rotation serves to relieve what would otherwise be a relatively close phosphate-phosphate contact at the junction of the two stems, while preserving the stabilizing effects of base stacking. The ability of the NMR data to determine pseudoknot bending was critically assessed. The data were found to be a modestly precise indicator of pseudoknot bending, with the angle between the helical axes of stem1 and stem2 being in the range of 15+/-15 degrees. Pseudoknot models with bend angles within this range are equally consistent with the data, since they differ by only small amounts in the relatively short-range interproton distances from which the structure was derived. The gene 32 messenger RNA pseudoknot was compared with other RNA structures with coaxial or near-coaxial stacked helical stems.

Tunable alignment of macromolecules by filamentous phage yields dipolar coupling interactions

Dipolar coupling interactions represent an extremely valuable source of long-range distance and angle information that was previously not available for solution structure determinations of macromolecules. This is because observation of these dipolar coupling data requires creating an anisotropic environment for the macromolecule. Here we introduce a new method for generating tunable degrees of alignment of macromolecules by addition of magnetically aligned Pf1 filamentous bacteriophage as a cosolute. This phage-induced alignment technique has been used to study 1H-1H, 1H-13C, and 1H-15N dipolar coupling interactions in a DNA duplex, an RNA hairpin and several proteins including thioredoxin and apo-calmodulin. The phage allow alignment of macromolecules over a wide range of temperature and solution conditions and thus represent a stable versatile method for generating partially aligned macromolecules in solution.

The immunogenic properties of human melanomas and melanoma-associated antigens recognized by cytotoxic T lymphocytes

During the last years significant progress has been achieved in the identification of melanoma-associated antigens (MAA) recognized by cytotoxic T lymphocytes (CTL). These antigens belong to three main groups: tumor-associated testis-specific antigens (MAGE, BAGE, GAGE and PRAME), melanocyte differentiation antigens (tyrosinase, Melan-A/MART-1, gp100, TRP-1 and TRP-2) and mutated or aberrantly expressed antigens (MUM-1, CDK4, beta-catenin, gp100-in4, p15 and N-acetylglucosaminyltransferase V). For the identification of these antigens, CTL cultures from mainly only 4 different melanoma patients have been used. These patients developed a strong anti-melanoma response resulting in long-lasting disease-free periods, pointing to the importance of the identification of highly immunogenic melanomas. In each of these patients, the immune response was observed against a unique set of 4 to 6 individual antigenic epitopes, on one hand suggesting the low immunogenicity of the individual antigens, and on the other pointing to the importance of the identification of additional highly immunogenic melanomas for the discovery of new MAA. The analysis of the available data on the immunogenic and protective properties of individual MAA confirms their low immunogenicity. In our study, we focused on the identification of especially highly immunogenic melanomas among a panel of 40 newly established melanoma cell lines. So far, only two such melanoma cell lines, FM3 and FM57 have been identified in this panel. The immunogenic properties of uncloned FM3 cells and several FM3 clones have been further investigated. It was found that the immunogenic properties of melanoma cells are mainly determined by the expression of progression-associated antigens as well as by ecto-ATPase, a molecule which is able to modulate cell adhesion. Cloning the cultures of PBL, stimulated with uncloned FM3 or with the highly immunogenic FM3 clone, FM3.29, has permitted us to identify the immune response against eight different MAA, five of these probably representing not previously described antigens. (Tab. 2, Fig. 2, Ref. 68.)

Effect of a sports food bar on fat utilisation and exercise duration

The manufacturer claims that using the Access Fat Conversion Activity Bar increases fat utilisation, which would have a glycogen-sparing effect and delay the onset of fatigue from endurance exercise. This claim was tested using seven trained distance runners who performed two trials of treadmill running at 73% of VO2max to exhaustion. In a counterbalanced design, subjects ingested either one Access Bar with water or water only prior to treadmill running. Times to exhaustion for the control and Access treatment trials were 104.6 +/- 24.9 min and 93.9 +/- 21.4 min, respectively, and were not significantly different (p > .05). Differences between trials were not observed for the respiratory exchange ratio, blood lactate or glucose concentrations, plasma glycerol concentration, or perceived exertion. Based on results from this study, it was concluded that the Access Bar does not affect fat or carbohydrate utilisation and does not improve exercise endurance.

Base-pairings within the RNA pseudoknot associated with the simian retrovirus-1 gag-pro frameshift site

Frameshift and readthrough sites within retroviral messenger RNAs are often followed by nucleotide sequences that have the potential to form pseudoknot structures. In the work presented here, NMR methods were used to characterize the base-pairings and structural features of the RNA pseudoknot downstream of the gag-pro frameshift site of simian retrovirus type-1 (SRV-1) and a functional mutant of the SRV-1 pseudoknot. Evidence is presented that these pseudoknots contain two A-form helical stems of six base-pairs each, connected by two loops, in a classic H-type pseudoknot topology. A particularly interesting feature is that the shorter of the two connecting loops, loop 1, consists of only a single adenosine nucleotide that spans the major groove of stem 2. In this respect, the frameshift-associated pseudoknots are structurally similar to the pseudoknot within the gene 32 mRNA of bacteriophage T2, previously characterized by NMR methods. Despite having similar nucleotide sequences, the solvent exchange rates of the imino protons at the junction of the helical stems in the wild-type and mutant frameshifting pseudoknots differ from each other and from the bacteriophage T2 pseudoknot. The implications of this finding are discussed.

Human epidermal growth factor-on molecular forms present in urine and blood

A sensitive enzyme-linked immunosorbent assay (ELISA) for quantitation of human epidermal growth factor (EGF) was employed to study EGF in urine and blood. The EGF/creatinine ratio in urine was significantly higher for women (range and (median); 0.20-0.83 (0.50) nmol EGF/mmol creatinine) than for men (0.17-0.63 (0.30) nmol EGF/mmol creatinine). We were not able to demonstrate EGF in plasma (median plasma EGF < 0.01 nmol/l) whereas serum contained a range and (median) of 0.02-0.31 (0.12) nmol EGF/l. The amount of EGF in serum showed a weak correlation to the platelet count (r = 0.327). EGF was partly purified by affinity chromatography from urine (urine EGF) and from activated platelets in platelet rich plasma (blood EGF). Both blood and urine contained a high molecular weight form of EGF (HMW EGF) as well as 6 kDa EGF. HMW EGF from blood was similar to HMW EGF from urine concerning behaviour upon gel filtration, pI and apparent affinity constant for binding to the EGF receptor. However, HMW EGF constituted approx. 40% of blood EGF but only 10% of urinary EGF. The 6 kDa EGF from both blood and urine contained two isopeptides with pI around 4.40 and 4.15 but in various proportions. The apparent affinity constant for binding to the EGF receptor for blood 6 kDa EGF was 1.8 x 10(10) l/mol compared to 1.0 x 10(10) l/mol for urinary 6 kDa EGF and 0.8 x 10(10) l/mol for HMW EGF from both blood and urine. The present study suggests that the processing of the EGF precursor differs in the blood and in the kidneys and that 6 kDa EGF from blood and urine binds to the EGF receptor with a higher apparent affinity constant than does HMW EGF.

Human salivary epidermal growth factor, haptocorrin and amylase before and after prolonged exercise

The concentration of epidermal growth factor (EGF), amylase, haptocorrin, total protein, sodium and potassium was studied in mixed saliva collected from 25 individuals before and after a 2 h-long cross-country race. The concentration was higher following the run for all components studied. The concentrations obtained before and after the run, given as extreme values and median, are 0.2-1.3 (0.4), 0.3-1.5 (0.8) nmol/l for EGF, 15-72 (25), 23-162 (58) nmol/l for haptocorrin and 24-502 (120), 155-5,030 (1,200) kU/l for amylase. The increased concentration of the components studied is most probably caused by an increased adrenergic and VIP'ergic tonus of the individuals after the run.

Primary structure of human intrinsic factor: progress report on cyanogen bromide fragmentation

Human intrinsic factor purified by labile ligand affinity chromatography was cleaved with cyanogen bromide and fractionated by gel filtration. Four of the fragments were purified and sequenced to a total of eighty-four amino acid residues. Including the N-terminal amino acids this amounts to one third of the total amino acid sequence of human intrinsic factor. One of the fragments contained a tyrosine labelled only on iodination of intrinsic factor devoid of cobalamin.