[Acute "difficult" gastrointestinal bleeding]

Gastrointestinal bleeding with its point of origin outside the reach of conventional gastro- and colonoscopy represents an extraordinary diagnostic and therapeutic challenge. Bleeding may originate from the small bowel distal to the duodenojejunal junction (middle gastrointestinal bleeding) or from the biliary tree (haemobilia) or from the pancreatic ductal system (haemosuccus pancreaticus). This particular type of gastrointestinal bleeding is often intermittend and caused by a variety of different pathologies. Angiography is the diagnostic method of choice for further investigation. It allows precise localization of the bleeding site and simultaneous interventional therapy (embolization/coiling). The importance of further diagnostic modalities such as scintigraphy, capsule endoscopy, push-enteroscopy and double-balloon-enteroscopy is discussed.

The -308 tumour necrosis factor-alpha gene polymorphism predicts therapeutic response to TNFalpha-blockers in rheumatoid arthritis and spondyloarthritis patients

OBJECTIVE: To examine whether the G-to-A polymorphism at position -308 in the promoter of the tumour necrosis factor-alpha (TNFalpha) gene influences the therapeutic response to TNFalpha-blockers in patients with rheumatoid arthritis (RA), psoriatic arthritis (PsA) and ankylosing spondylitis (AS). METHODS: A total of 54 patients with RA, 10 with PsA and 22 with AS were genotyped by polymerase chain reaction for the -308 TNFalpha promoter polymorphism. They were treated with infliximab (n = 63), adalimumab (n = 10) or etanercept (n = 13). Clinical response was assessed after 24 weeks by the Disease Activity Score in 28 joints (DAS28) for RA and PsA, and the Bath Ankylosing Spondylitis Activity Index (BASDAI) for AS patients. RESULTS: All patients with the A/A genotype (n = 3, all RA) and two patients with the A/G genotype (AS) failed to respond to anti-TNF treatment. Irrespective of the underlying disease, moderate response (n = 44) was predominantly associated with the A/G genotype (A/G 18/22, G/G 4/22), whereas good response (n = 59) was exclusively seen in patients with the G/G genotype. The average improvement in the DAS28 score was 0.83 in the A/A, 1.50 in the A/G and 2.64 in the G/G group of RA and PsA patients (P < 0.0001). The BASDAI score in AS improved on average by 1.21 in the A/G and by 3.30 in the G/G group (P < 0.005). CONCLUSIONS: The data suggest that humans with a TNFalpha -308 G/G genotype are better responders to anti-TNFalpha treatment than those with A/A or A/G genotypes independent of the treated rheumatic disease (RA, PsA or AS).

Testing strategies and follow-up for coeliac disease in a general internal medicine outpatient department from 2000 to 2005

PRINCIPLES: Coeliac disease (gluten sensitive enteropathy) is a genetically determined disorder with an incidence in the general population that is comparable to type 2 diabetes mellitus. Awareness of this fact and of the often atypical and oligosymptomatic manifestations is only now gaining ground in the medical profession. A high index of suspicion is important in order to minimise diagnostic and therapeutic delay. METHODS: Testing patterns and follow-up for coeliac disease in our institution have been analysed retrospectively for the past five years. The current literature was reviewed with respect to recommendations for clinical practice. RESULTS: A total of 271 patients were tested for coeliac disease over a period of five years. Only in 24 patients were positive results found; after further work-up, the final number of cases with certain or presumed coeliac disease was four. Followup was often difficult, many patients being lost after a single visit. CONCLUSIONS: This study showed that the number of tests ordered in our institution, more often for abdominal than atypical symptoms, has started to increase in the past two years. It also showed that screening tests have found their place in general clinical practice, while the final choice of tests needs to be determined in accordance with available guidelines and local resources. Upper endoscopy with small bowel biopsy remains the gold standard for diagnosis, but its place in follow-up is less certain. Coeliac disease is a disorder for which there is a definite treatment (gluten free diet); if it is left untreated diminished quality of life and potentially serious complications may ensue. Further education of the medical profession regarding coeliac disease, its incidence, presentation and treatment, is clearly indicated..

Differential regulation of metzincins in experimental chronic renal allograft rejection: potential markers and novel therapeutic targets

Chronic renal allograft rejection is characterized by alterations in the extracellular matrix compartment and in the proliferation of various cell types. These features are controlled, in part by the metzincin superfamily of metallo-endopeptidases, including matrix metalloproteinases (MMPs), a disintegrin and metalloproteinase (ADAM) and meprin. Therefore, we investigated the regulation of metzincins in the established Fisher to Lewis rat kidney transplant model. Studies were performed using frozen homogenates and paraffin sections of rat kidneys at day 0 (healthy controls) and during periods of chronic rejection at day +60 and day +100 following transplantation. The messenger RNA (mRNA) expression was examined by Affymetrix Rat Expression Array 230A GeneChip and by real-time Taqman polymerase chain reaction analyses. Protein expression was studied by zymography, Western blot analyses, and immunohistology. mRNA levels of MMPs (MMP-2/-11/-12/-14), of their inhibitors (tissue inhibitors of metalloproteinase (TIMP)-1/-2), ADAM-17 and transforming growth factor (TGF)-beta1 significantly increased during chronic renal allograft rejection. MMP-2 activity and immunohistological staining were augmented accordingly. The most important mRNA elevation was observed in the case of MMP-12. As expected, Western blot analyses also demonstrated increased production of MMP-12, MMP-14, and TIMP-2 (in the latter two cases as individual proteins and as complexes). In contrast, mRNA levels of MMP-9/-24 and meprin alpha/beta had decreased. Accordingly, MMP-9 protein levels and meprin alpha/beta synthesis and activity were downregulated significantly. Members of metzincin families (MMP, ADAM, and meprin) and of TIMPs are differentially regulated in chronic renal allograft rejection. Thus, an altered pattern of metzincins may represent novel diagnostic markers and possibly may provide novel targets for future therapeutic interventions.

[Urine analyses for workup of kidney stone disease--interpretation and therapeutic consequences]

Nephrolithiasis is a disease with a high and even rising incidence. It has a high morbidity, generates high costs and has a high recurrence rate. Urinalysis is of importance especially in recurrent stone formers. It allows the identification and quantification of risk factors and the establishment of individual risk profiles. Based on these individual risk profiles, rational therapy for metaphylaxis of kidney stones lowers stone recurrence rates significantly. This review article aims to give a focussed overview of the most important risk factors for kidney stones and reasonable urine tests for evaluation of recurrent kidney stone formers.

[Spontaneous and post-therapeutic cartilage repair: evaluation criteria.]

Articular cartilage has poor reparative capacities, and once damaged cartilage lesions remain chronic and can lead to osteoarthritis. Over the last decade, several innovative therapies have been introduced to promote the regeneration of articular cartilage while sustaining sufficient mechanical stress and permitting a pain free motion. An important measure of outcome is the morphological characterization of the repair tissue in order to allow for cross-study evaluation. The International Cartilage Repair Society has developed a analogue visual scale to quantify repair tissue, which is described in this paper.

Therapeutic protein transduction of mammalian cells and mice by nucleic acid-free lentiviral nanoparticles

The straightforward production and dose-controlled administration of protein therapeutics remain major challenges for the biopharmaceutical manufacturing and gene therapy communities. Transgenes linked to HIV-1-derived vpr and pol-based protease cleavage (PC) sequences were co-produced as chimeric fusion proteins in a lentivirus production setting, encapsidated and processed to fusion peptide-free native protein in pseudotyped lentivirions for intracellular delivery and therapeutic action in target cells. Devoid of viral genome sequences, protein-transducing nanoparticles (PTNs) enabled transient and dose-dependent delivery of therapeutic proteins at functional quantities into a variety of mammalian cells in the absence of host chromosome modifications. PTNs delivering Manihot esculenta linamarase into rodent or human, tumor cell lines and spheroids mediated hydrolysis of the innocuous natural prodrug linamarin to cyanide and resulted in efficient cell killing. Following linamarin injection into nude mice, linamarase-transducing nanoparticles impacted solid tumor development through the bystander effect of cyanide.

Autofluorescence endoscopy in surveillance of Barrett's esophagus: a multicenter randomized trial on diagnostic efficacy

BACKGROUND AND STUDY AIMS: The reference surveillance method in patients with Barrett's esophagus is careful endoscopic observation, with targeted as well as random four-quadrant biopsies. Autofluorescence endoscopy (AFE) may make it easier to locate neoplasia. The aim of this study was to elucidate the diagnostic accuracy of surveillance with AFE-guided plus four-quadrant biopsies in comparison with the conventional approach. PATIENTS AND METHODS: A total of 187 of 200 consecutive Barrett's esophagus patients who were initially enrolled (73 % male, mean age 67 years, mean Barrett's segment length 4.6 cm), who underwent endoscopy for Barrett's esophagus in four study centers, were randomly assigned to undergo either AFE-targeted biopsy followed by four-quadrant biopsies or conventional endoscopic surveillance, also including four-quadrant biopsies (study phase 1). After exclusion of patients with early cancer or high-grade dysplasia, who underwent endoscopic or surgical treatment, as well as those who declined to participate in phase 2 of the study, 130 patients remained. These patients were examined again with the alternative method after a mean of 10 weeks, using the same methods described. The main study parameter was the detection of early cancer/adenocarcinoma or high-grade dysplasia (HGD), comparing both approaches in study phase 1; the secondary study aim in phase 2 was to assess the additional value of the AFE-guided approach after conventional surveillance, and vice versa. Test accuracy measures were derived from study phase 1. RESULTS: In study phase 1, the AFE and conventional approaches yielded adenocarcinoma/HGD rates of 12 % and 5.3 %, respectively, on a per-patient basis. With AFE, four previously unrecognized adenocarcinoma/HGD lesions were identified (4.3 % of the patients); with the conventional approach, one new lesion (1.1 %) was identified. Of the 19 adenocarcinoma/HGD lesions detected during AFE endoscopy in study phase 1, eight were visualized, while 11 were only detected using untargeted four-quadrant biopsies (sensitivity 42 %). Of the 766 biopsies classified at histology as being nonneoplastic, 58 appeared suspicious (specificity 92 %, positive predictive value 12 %, negative predictive value 98.5 %). In study phase 2, AFE detected two further lesions in addition to the initial alternative approach in 3.2 % of cases, in comparison with one lesion with conventional endoscopy (1.7 %). CONCLUSIONS: In this referral Barrett's esophagus population with a higher prevalence of neoplastic lesions, the AFE-guided approach improved the diagnostic yield for neoplasia in comparison with the conventional approach using four-quadrant biopsies. However, AFE alone was not suitable for replacing the standard four-quadrant biopsy protocol.

Immune cell migration across the blood–brain barrier: molecular mechanisms and therapeutic targeting

The endothelial blood–brain barrier (BBB) and the epithelial blood–cerebrospinal fluid barrier protect the CNS from the constantly changing milieu within the bloodstream. The BBB strictly controls immune cell entry into the CNS, which is rare under physiological conditions. During a variety of pathological conditions of the CNS, such as viral or bacterial infections, or during inflammatory diseases, such as multiple sclerosis, immunocompetent cells readily traverse the BBB and subsequently enter the CNS parenchyma. Most of the available information on immune cell entry into the CNS is derived from studying experimental autoimmune encephalomyelitis (EAE), an animal model for multiple sclerosis. Consequently, our current knowledge on traffic signals mediating immune cell entry across the BBB during immunosurveillance and disease results mainly from experimental data in the EAE model. Therefore, a large part of this review summarizes these findings. Similarly, the potential benefits and risks associated with therapeutic targeting of immune cell trafficking across the BBB will be discussed in the context of multiple sclerosis, since elucidation of the molecular mechanisms relevant to this disease have largely relied on the use of its in vivo model, EAE.