One Step Away from Technology but One Step Towards Domain Experts-MDRBridge: A Template-Based ISO 11179-Compliant Metadata Processing Pipeline

BACKGROUND

Secondary use of routine medical data relies on a shared understanding of given information. This understanding is achieved through metadata and their interconnections, which can be stored in metadata repositories (MDRs). The necessity of an MDR is well understood, but the local work on metadata is a time-consuming and challenging process for domain experts.

OBJECTIVE

To support the identification, collection, and provision of metadata in a predefined structured manner to foster consolidation. A particular focus is placed on user acceptance.

METHODS

We propose a software pipeline MDRBridge as a practical intermediary for metadata capture and processing, based on MDRSheet, an ISO 11179-3 compliant template using popular spreadsheet software. It serves as a practical mediator for metadata acquisition and processing in a broader pipeline. Due to the different origins of the metadata, both manual entry and automatic extractions from application systems are supported. To enable the export of collected metadata into external MDRs, a mapping of ISO 11179 to Clinical Data Interchange Standards Consortium (CDISC) Operational Data Model (ODM) was developed.

RESULTS

MDRSheet is embedded in the processing pipeline MDRBridge and delivers metadata in the CDISC ODM format for further use in MDRs. This approach is used to interactively unify core datasets, import existing standard datasets, and automatically extract all defined data elements from source systems. The involvement of clinical domain experts improved significantly due to minimal changes within their usual work routine.

CONCLUSION

A high degree of acceptance was achieved by adapting the working methods of clinical domain experts. The designed process is capable of transforming all relevant data elements according to the ISO 11179-3 format. MDRSheet is used as an intermediate format to present the information at a glance and to allow editing or supplementing by domain experts.

Is the elusive Gymnothorax polyuranodon really a freshwater moray?

Analysis of 36 records of the rarely encountered moray Gymnothorax polyuranodon indicate that juveniles and adults inhabit fresh and mildly brackish habitats (salinity < 5) in streams of the Australian Wet Tropics Eighty-one per cent of these records were from freshwater streams and collectively demonstrate that this species inhabits fresh water throughout all seasons. A survey of fish researchers, each with at least 100 h of field experience in Australia's Wet Tropics, revealed that 33% of researchers working in fresh waters (nine of 27 researchers) had encountered the species and 15% of researchers with substantial experience working in estuaries (two of 13 researchers) had encountered the species. The species was not sampled or observed in the nearshore marine environment. The only record of an elver of this species was, however, found in an estuary at a salinity of 33·4. This preliminary evidence suggests adult G. polyuranodon occupy freshwater habitats, but further research is required to understand the complete life cycle, including movements, habitat use and reproductive ecology of the species.

Increased titers of antibodies against streptococcal M12 and M19 proteins in patients with Tourette's syndrome

It has been suggested that a post-streptococcal autoimmune process may be involved in the pathogenesis of a subgroup of children with tics and obsessive-compulsive symptoms (PANDAS). Elevated antibody titers against streptococcal antigens have also been described in adult patients suffering from Tourette's syndrome (TS). In order to characterise further streptococcal antigens, we focussed on M proteins. M proteins are a major virulence factor of group A streptococci and known to evoke an immunologic cross-reaction with diverse epitopes of human tissue including brain tissue. Therefore, antibodies against M proteins may play a role in the pathophysiology of at least a subgroup of TS patients. Antibodies against M proteins were studied in 25 adult patients suffering from TS and 25 healthy controls after careful medical examination. The antibody titers against the peptides M1, M4, M6, M12 and M19 were estimated by ELISA. Our results show increased titers of antibodies against the streptococcal M12 and M19 proteins in TS patients as compared with controls, while antibody titers against M1, M4 and M6 did not differ between the TS and control groups. Elevated serum titers of antibodies against M12 and M19 proteins support the view that a streptococcus-induced autoimmune process may be involved in TS. The finding of a possible autoimmune origin of TS has implications for both pathophysiology and future therapeutic strategies.

A phase II study of Biotene in the treatment of postradiation xerostomia in patients with head and neck cancer

One of the major side effects of radical radiation therapy for head and neck malignancies is xerostomia, or dryness of the mouth. There is no clearly effective treatment for this condition, but we have observed that patients in our practice believe that their symptoms improve significantly when using two "over-the-counter" oral comfort products - Biotene (toothpaste, mouthwash and chewing gum) and Oralbalance gel. We decided to study these agents in a formal phase II study to evaluate their usefulness in patients with postirradiation xerostomia. Twenty-eight patients with post-irradiation xerostomia were entered on the study. All had biopsy-proven carcinoma of the nasopharynx, oropharynx, oral cavity, hypopharynx or larynx, and had received primary radiotherapy with curative intent (> or =50 Gy in 20 fractions) more than 4 months before study entry. More than 75% of both parotid glands were included in the primary radiation field. There was no clinical evidence of recurrent disease. Patients were provided with a 2-month supply of Biotene mouthwash, toothpaste, chewing gum and Oralbalance gel. Response was evaluated 1 and 2 months after study entry using a patient-completed visual analogue scale to assess the severity of xerostomia and its effects on quality of life. For analysis, the scored baseline was subtracted from the later scores to assess change. Patients with an increase of 10 mm from their baseline score on the visual analogue scale were classified as having responded to the treatment intervention, and those with an increase of > or =25 mm from their baseline score were classified as having experienced a major improvement in their symptoms. After 2 months of treatment, 15 patients (54%) reported an improvement in intraoral dryness and 10 of these patients (36%) reported a major improvement. Similar proportions of patients (46% some improvement, 25% major improvement) reported an improvement in their ability to eat normally. Seventeen patients (61%) reported an improvement in oral discomfort, and 12 of these (43%) had a major improvement in their symptoms. The results of this study suggest that the use of Biotene (mouthwash, toothpaste and chewing gum) and Oralbalance gel can improve many of the symptoms of radiation-induced xerostomia. A placebo effect could account for many of the observed improvements in symptoms, and in order to assess the role of these agents in the management of patients with postirradiation xerostomia a randomised phase III study is needed.

[Self-assessment by patients of impairment caused by obstructive sleep apnea syndrome]

BACKGROUND AND OBJECTIVE

The compliance of the nasal continuous positive airway pressure treatment (nCPAP) of the obstructive sleep apnea syndrome (OSAS) depends on the patients' awareness and improvement of the symptoms. Therefore, we studied the relevance of OSAS in different aspects of the quality of life and important aspects of daily life (driving performance, working place).

METHODS

352 patients with OSAS filled in a questionnaire of sociodemographic data and impairment of quality of life. The relevance of OSAS was evaluated with polysomnography and parameters of daytime sleepiness.

RESULTS

The number of women was lower than expected from community related data. The apnea/hypopnea index was 29.9 +/- 23.4/h at baseline measurement and was reduced to 8.8 +/- 9.6/h with nCPAP (p < 0.001). The arousal index (baseline 26.6 +/- 15.3/h) fell with treatment significantly (17.7 +/- 9.2 Arousals/h, p < 0.001). The error rate in the driving simulator test was 7.8 +/- 8.9% (normal value 5.75 +/- 1.4). It was normalised with nCPAP (5.8 +/- 9.5, p < 0.001). 42.3% of patients reported about sleep apnea related symptoms for more than five years before diagnosis. The patients rated their physical fitness on a scale (0 to 6) at 2.9 +/- 1.3. It increased significantly with treatment to 3.4 +/- 1.3 an (p < 0.001). The mental activity improved significantly, too. The daytime sleepiness improved from 3.4 +/- 1.5 to 3.1 +/- 1.5 (p < 0.001). 32.3% of the patients reported that they fell asleep while steering at least once in the last month, 13.0% reported about more than five episodes/month. 5.3% of the patients thought their job in danger because of OSAS. 65.1% felt their performance in job to be impaired.

CONCLUSION

OSAS impairs patients in different aspects of daily life, especially in the working place. The latency between the onset of symptoms and diagnosis is longer than expected. NCPAP treatment improves the symptoms of OSAS significantly both in criteria of polysomnography and self-assessment of the patients.

Effect of lindane and phenobarbital on cyclooxygenase-2 expression and prostanoid synthesis by Kupffer cells

Prostaglandins (PGs) have been implicated in tumor promotion. In this study, we investigated the effect of the hepatic tumor promoters lindane and phenobarbital (PB) on the PG metabolism of Kupffer cells in vitro and in vivo, in particular on the expression of cyclooxygenase (COX), the leading enzyme in prostanoid synthesis. Exposure of primary cultures of Kupffer cells to lindane for 1 h stimulated the production of the PGs PGE(2) and PGD(2) markedly (up to 50-fold) and that of PGF(2alpha) by >3-fold. This effect was accompanied by an increase in the COX-2 protein, as demonstrated by western blotting. Similarly, PB, which shares several effects with lindane in rat liver, also clearly induced COX-2. Lindane and PB affected the PG synthesis in vitro and in vivo in Kupffer cells of rats that had been treated with the two compounds for 56 days. Kupffer cells, which were isolated at days 2, 5 and 56 of the treatment, showed a significant increase in the levels of COX-2 mRNA and protein. Total COX activity was increased approximately 2-fold and 3- to 5-fold in Kupffer cell homogenates of PB- and lindane-treated animals, respectively, compared with the untreated controls. These results suggest that paracrine mechanisms may contribute to the tumor-promoting activity of lindane and PB, stimulating the production of PGs by Kupffer cells.

Inhibition of transforming growth factor-beta1 and UV light-induced apoptosis by prostanoids in primary cultures of rat hepatocytes

Treatment of rat hepatocytes cultured in collagen gel with transforming growth factor-beta1 (TGFbeta1) or with UV light strongly increased the frequency of apoptotic nuclei within 24 h; at doses of 0.5 ng/ml TGFbeta1 or 90 J/m2 UV light about 17 and 22% apoptotic nuclei were determined, respectively. DNA of the treated cells showed internucleosomal DNA fragmentation. Already the presence of the cytokine for only 1 h significantly induced apoptosis. The prostanoids PGI2, PGD2, and PGE1 decreased the frequency of apoptotic nuclei in a dose-dependent manner by up to 70 to 80% and suppressed internucleosomal DNA fragmentation. In contrast, PGE2 and PGF2alpha elicited a smaller protective effect and arachidonic acid had none. In the case of PGE1 it was shown that the prostaglandin was most effective when added together with TGFbeta1 or within 2 h before or after treatment with this cytokine. An early increase of the tumor suppressor gene product p53 is thought to play a decisive role in UV light-induced apoptosis. However, this increase in p53 was not affected by the strong cytoprotective prostacyclin PGI2. Our findings show a marked antiapoptotic activity of the prostanoids PGE1, PGI2, and PGD2 and raise the question of whether these prostanoids may influence apoptosis in pathological processes in the liver.

M-mode sonography of the caudal spinal cord in patients with meningomyelocele. Work in progress

The authors prospectively studied movement patterns of the spinal cord in 46 patients (aged 0.5-16 years) with meningomyelocele but without major neurologic deficits. Three different motion patients were observed. Reduced mobility correlated with a higher risk of developing secondary tethered cord syndrome after a mean observation time of 15 months. This technique may be helpful in identifying patients for early surgery.

Proton transport mechanism in the cell membrane of Xenopus laevis oocytes

Mechanisms of H+ transport across the plasma cell membrane of prophase-arrested oocytes of Xenopus laevis were investigated by testing the effect of ion substitutions and inhibitors on cytoplasmic pH (pHi), membrane potential (Vm) and membrane resistance (Rm). During superfusion with control solution of pH = 7.4, pHi was 7.49 +/- 0.12 (n = 15), Vm was -61.9 +/- 7.8 mV (n = 34) (cytoplasm negative), and Rm was 2.9 +/- 1.5 M omega (n = 19). These data confirm that H+ ions are not distributed at electrochemical equilibrium. By following pHi during recovery of the oocytes from an acid load (20 mmol/l NH4Cl) in the presence and absence of extracellular Na+ or amiloride (1 mmol/l), a Na/H exchanger was identified. On the basis of the known Na+ gradient across the cell membrane, this transporter could suffice to generate the observed H+ disequilibrium distribution. Utilizing blockers or ion-concentration-step experiments no evidence was obtained for an ATP-driven H+ pump or for passive acid/base transporters such as H+ conductances or Na+ (HCO3-)3 cotransport. The membrane depolarization observed in response to extracellular acidification appeared to result from a pH-dependent, Ba(2+)-inhibitable K+ conductance.

Functional expression of a human C5a receptor clone in Xenopus oocytes requires additional RNA

cRNA from a PCR-generated C5aR clone was prepared by in vitro transcription and microinjected into Xenopus laevis oocytes. Ligand-induced whole cell current could be detected after co-injection of cRNA for the C5aR with total RNA of the unstimulated U937 cell line, but not with either of the components injected alone. These data clearly demonstrate an absolute requirement of the C5aR for an additional human factor to become functionally expressed in Xenopus oocytes.

Sodium dependence of the epithelial sodium conductance expressed in Xenopus laevis oocytes

The epithelial Na+ conductance was expressed in Xenopus laevis oocytes by injection of size-fractionated mRNA of bovine tracheal epithelium. Fractionation was achieved by sucrose density gradient centrifugation. Successful expression was analysed by recording current/voltage (I/V) curves in the presence and absence of amiloride (10 mumol/l). The newly expressed conductance was half-maximally inhibited by 44 nmol/l amiloride and exhibited a selectivity for Na+ over K+ of 140:1. I/V curves obtained at different extracellular Na+ concentrations ([Na+]o) were subjected to a Goldman-fit analysis to obtain the relation between Na+ permeability (PNa) and [Na+]o. The data show that decreasing [Na+]o from 85 mmol/l to 0.85 mmol/l increased PNa by more than threefold, which is thought to reflect Na+ channel inhibition by increasing [Na+]o. This effect clearly exceeded what can be attributed to concentration saturation of single Na+ channel conductance (Palmer and Frindt (1986) Proc Natl Acad Sci USA 83:2767). No correlation of inhibition with intracellular Na+ concentration was observed. Preservation of the [Na+]o-dependent self-inhibition by the newly expressed Na+ conductance suggests that it is an intrinsic property of the Na+ channel protein, probably mediated by an extracellular Na+ binding site.

Selective expression of an amiloride-inhibitable Na+ conductance from mRNA of respiratory epithelium in Xenopus laevis oocytes

Poly(A)+RNA was prepared from primary cultures of human nasal polyp epithelia and from native bovine tracheal epithelia. Six to fifty nanograms mRNA were injected into prophase-arrested immature Xenopus laevis oocytes. One to four days later the oocytes were probed with electrophysiological techniques for induction of novel ion conductances. Oocytes injected with mRNA had lower membrane potentials (Vm) and resistances (Rm) than controls. By use of step changes in extracellular Na+ concentration and applying amiloride, a Na+ conductance could be identified in mRNA-injected oocytes, which was inhibited by submicromolar concentrations of amiloride with the same kinetics (Ki = 1.3 X 10(-7) mol/l) as in the original tissue. After complete inhibition of this conductance by 10(-5) mol/l amiloride, Vm and Rm approached the respective values of controls. The data indicate that oocytes express functional epithelial Na+ channels but apparently no other epithelial ion conductances from injected mRNA of respiratory epithelium.