MicroRNAs play a role in spontaneous recovery from acute liver failure

Acute liver failure (ALF) represents a life-threatening situation characterized by sudden and massive liver cell death in the absence of preexisting liver disease. Although most patients require liver transplantation to prevent mortality, some recover spontaneously and show complete liver regeneration. Because of the rarity of this disease, the molecular mechanisms regulating liver regeneration in ALF patients remain largely unknown. In this study, we investigated the role of microRNAs (miRs) that have been implicated in liver injury and regeneration in sera from ALF patients (n = 63). Patients with spontaneous recovery from ALF showed significantly higher serum levels of miR-122, miR-21, and miR-221, compared to nonrecovered patients. In liver biopsies, miR-21 and miR-221 displayed a reciprocal expression pattern and were found at lower levels in the spontaneous survivors, whereas miR-122 was elevated in both serum and liver tissue of those patients. As compared to nonrecovered patients, liver tissue of spontaneous survivors revealed not only increased hepatocyte proliferation, but also a strong down-regulation of miRNA target genes that impair liver regeneration, including heme oxygenase-1, programmed cell death 4, and the cyclin-dependent kinase inhibitors p21, p27, and p57.

CONCLUSION

Our data suggest that miR-122, miR-21, and miR-221 are involved in liver regeneration and might contribute to spontaneous recovery from ALF. Prospective studies will show whether serological detection of those miRNAs might be of prognostic value to predict ALF outcome.

Increased apoptosis induction in hepatocellular carcinoma by a novel tumor-targeted TRAIL fusion protein combined with bortezomib

As the result of an increasing incidence and a prevalent therapy resistance of hepatocellular carcinoma (HCC), there is a strong need for novel strategies to enhance treatment responses in HCC. Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) has been proposed as a promising anticancer drug because it can selectively induce apoptosis in cancer cells, but not in healthy cells. Nevertheless, most tumor cells show TRAIL resistance, emphasizing the requirement for apoptosis-sensitizing agents and TRAIL molecules with improved tumor specificity. In this study, we employed a recombinant TRAIL molecule, in which three TRAIL protomers were expressed as a single polypeptide chain (scTRAIL), and a novel TRAIL variant, in which scTRAIL was additionally fused to an antibody fragment recognizing epidermal growth factor receptor (EGFR) to improve its HCC-targeting properties. We analyzed the proapoptotic effects of both TRAIL versions in combination with the proteasome inhibitor bortezomib (BZB) in hepatoma cells and primary human hepatocytes as well as in intact explants from HCC and healthy liver tissue. We demonstrate that EGFR-targeted TRAIL in combination with BZB induced significantly higher caspase activation and cell death in hepatoma cells, but not in primary hepatocytes. Importantly, when incubated with fresh liver explants, the combination of EGFR-targeted TRAIL and BZB displayed selective cytotoxicity for HCC, but not for tumor-free liver tissue, which could even be verified in liver explants from the same individuals. Unlike nontargeted TRAIL, EGFR-targeted TRAIL combined with BZB exerted no toxicity in liver tissues from nonalcoholic fatty liver disease patients.

CONCLUSION

EGFR-targeted TRAIL reveals increased antitumor activity toward HCC without inducing toxicity to tumor-free liver tissue and might therefore represent a promising novel strategy for HCC treatment.

Biopsy-controlled liver fibrosis staging using the enhanced liver fibrosis (ELF) score compared to transient elastography

BACKGROUND AND AIMS

Chronic liver diseases are characterized by inflammatory and fibrotic liver injuries that often result in liver cirrhosis with its associated complications such as portal hypertension and hepatocellular carcinoma. Liver biopsy still represents the reference standard for fibrosis staging, although transient elastography is increasingly used for non-invasive monitoring of fibrosis progression. However, this method is not generally available and is associated with technical limitations emphasizing the need for serological biomarkers staging of liver fibrosis. The enhanced liver fibrosis (ELF) score was shown to accurately predict significant liver fibrosis in different liver diseases, although extracellular matrix components detected by this score may not only mirror the extent of liver fibrosis but also inflammatory processes.

METHODS

In this prospective biopsy-controlled study we evaluated the utility of the ELF score in comparison to transient elastography to predict different stages of fibrosis in 102 patients with chronic liver diseases.

RESULTS

Both techniques revealed similar area under receiver operating characteristic curve values for prediction of advanced fibrosis stages. Compared to transient elastography, the ELF score showed a broader overlap between low and moderate fibrosis stages and a stronger correlation with inflammatory liver injury.

CONCLUSIONS

Both the ELF score as well as transient elastography allowed for high quality fibrosis staging. However, the ELF score was less discriminative in low and moderate fibrosis stages and appeared more strongly influenced by inflammatory liver injury. This should be considered when making clinical interpretations on the basis of ELF score values.

Superior antitumoral activity of dimerized targeted single-chain TRAIL fusion proteins under retention of tumor selectivity

Although targeting of the death receptors (DRs) DR4 and DR5 still appears a suitable antitumoral strategy, the limited clinical responses to recombinant soluble TNF-related apoptosis inducing ligand (TRAIL) necessitate novel reagents with improved apoptotic activity/tumor selectivity. Apoptosis induction by a single-chain TRAIL (scTRAIL) molecule could be enhanced >10-fold by generation of epidermal growth factor receptor (EGFR)-specific scFv-scTRAIL fusion proteins. By forcing dimerization of scFv-scTRAIL based on scFv linker modification, we obtained a targeted scTRAIL composed predominantly of dimers (Db-scTRAIL), exceeding the activity of nontargeted scTRAIL ∼100-fold on Huh-7 hepatocellular and Colo205 colon carcinoma cells. Increased activity of Db-scTRAIL was also demonstrated on target-negative cells, suggesting that, in addition to targeting, oligomerization equivalent to an at least dimeric assembly of standard TRAIL per se enhances apoptosis signaling. In the presence of apoptosis sensitizers, such as the proteasomal inhibitor bortezomib, Db-scTRAIL was effective at picomolar concentrations in vitro (EC(50) ∼2 × 10(-12) M). Importantly, in vivo, Db-scTRAIL was well tolerated and displayed superior antitumoral activity in mouse xenograft (Colo205) tumor models. Our results show that both targeting and controlled dimerization of scTRAIL fusion proteins provides a strategy to enforce apoptosis induction, together with retained tumor selectivity and good in vivo tolerance.

Prospective biopsy-controlled evaluation of cell death biomarkers for prediction of liver fibrosis and nonalcoholic steatohepatitis

Fibrosis and steatosis are major histopathological alterations in chronic liver diseases. Despite various shortcomings, disease severity is generally determined by liver biopsy, emphasizing the need for simple noninvasive methods for assessing disease activity. Because hepatocyte cell death is considered a crucial pathogenic factor, we prospectively evaluated the utility of serum biomarkers of cell death to predict different stages of fibrosis and steatosis in 121 patients with chronic liver disease. We compared the M30 enzyme-linked immunosorbent assay (ELISA), which detects a caspase-cleaved cytokeratin-18 (CK-18) fragment and thereby apoptotic cell death, with the M65 ELISA, which detects both caspase-cleaved and uncleaved CK-18 and thereby overall cell death. Both biomarkers significantly discriminated patients with different fibrosis stages from healthy controls. However, whereas both markers differentiated low or moderate from advanced fibrosis, only the M65 antigen could discriminate even lower stages of fibrosis. The M65 assay also performed better in distinguishing low (≤10%) and higher (>10%) grades of steatosis. In a subgroup of patients, we evaluated the biomarkers for their power to predict nonalcoholic steatohepatitis (NASH). Importantly, both markers accurately differentiated healthy controls or simple steatosis from NASH. However, only serum levels of M65 antigen could differentiate simple steatosis from healthy controls.

CONCLUSION

Cell death biomarkers are potentially useful to predict fibrosis, steatosis, or NASH. Compared with the widely used apoptosis marker M30, the M65 assay had a better diagnostic performance and even differentiated between lower fibrosis stages as well as between healthy individuals and patients with simple steatosis.

Apoptosis of regulatory T lymphocytes is increased in chronic inflammatory bowel disease and reversed by anti-TNFα treatment

BACKGROUND AND AIMS

Inappropriate immune responses contribute to the continuous stimulation of the intestinal immune system in chronic inflammatory bowel disease (IBD). Among several pathogenic factors, a numerical deficiency of regulatory T (Treg) cells has been suggested to lead to an insufficient compensation of chronically activated T lymphocytes. This study was conducted to investigate whether increased apoptosis contributes to Treg cell deficiency in IBD and whether successful treatment with antitumour necrosis factor α (TNFα) is achieved by reducing of Treg cell apoptosis.

METHODS

Apoptosis of CD4(+)Foxp3(+) Treg cells in tissue sections of patients with active IBD was analysed by immunohistochemistry and TUNEL (terminal deoxynucleotidyl transferase dUTP nick end labelling) staining. Apoptosis of peripheral blood CD4(+)CD25(+)Foxp3(+) Treg cells was investigated by flow cytometry and annexin-V staining. In addition, caspase activity and apoptosis were measured in sera of patients with IBD treated with anti-TNFα by a luminometric caspase enzyme assay.

RESULTS

It is demonstrated that patients with active IBD revealed increased apoptosis of local CD4(+)Foxp3(+) Treg cells in the inflamed mucosa compared with non-inflamed control colon tissue. Moreover, in peripheral blood a reduced frequency and increased apoptosis of Treg cells were found and accompanied by elevated caspase activity in the serum. During anti-TNFα treatment, Treg cell apoptosis declined in close correlation with elevated peripheral Treg cell numbers and a decrease of caspase activation and disease activity.

CONCLUSIONS

These data suggest that increased apoptosis of Treg cells plays a potentially important role in the pathogenesis of IBD and can be reversed by anti-TNFα treatment. Measurement of Treg cell apoptosis and serum caspase activity might therefore represent promising tools for monitoring disease activity and treatment response in patients with IBD.

Obsessive-Compulsive Disorder (OCD) is still an unrecognised disorder: a study on the recognition of OCD in psychiatric outpatients

OBJECTIVE

The study aims to investigate the recognition of patients with Obsessive-Compulsive Disorder (OCD) in psychiatric outpatients.

SUBJECTS AND METHODS

A total of 2282 outpatients seen at 14 different psychiatric clinics in South Germany were asked to participate in the study. Five hundred and eighty-nine (30%) of the original 2282 patients met screening criteria for OCD, and of those, 237 (42%) participated in the final interview including DSM-IV diagnosis, and comorbidity.

RESULTS

Sixty-nine of 589 participating patients who screened positively for obsessive symptoms actually had an Obsessive-Compulsive Disorder. Only 19 (28%) of the outpatients diagnosed with OCD according to DSM-IV criteria were also given this diagnosis by their consultant. The psychopathology scores indicated that the OCD patients had clinically relevant OCD with a mean Yale-Brown Obsessive Compulsive Score (Y-BOCS) of 17.5 (± 5.4), and a mean Clinical Global Impression Score (CGI) of 5.2 (± 1.2).

CONCLUSIONS

In outpatient clinics over 70% of OCD patients remain unrecognised and thus untreated by consultants. Screening questions provide a rapid way of identifying those who may have OCD and should be incorporated into every mental state examination by consultants.

Enhanced perceived responsibility decreases metamemory but not memory accuracy in obsessive–compulsive disorder (OCD)

Mixed findings have been obtained in prior research with respect to the presence and severity of memory and metamemory deficits in obsessive-compulsive disorder (OCD). We tested the hypothesis that experimentally induced increments of subjective responsibility would lead to a disproportionately strong decline of memory confidence and enhanced response latencies in OCD while leaving memory accuracy unaffected. Twenty-eight OCD patients and 28 healthy controls were presented a computerized memory test framed with two different scenarios. In the neutral scenario, the participant was requested to imagine purchasing 15 items from a do-it-yourself store. In the recognition phase, the 15 needed items were presented along with 15 distractor items. The participant was asked to decide whether items were on his or her shopping list or not, graded by subjective confidence. In the responsibility scenario, the general experimental setup was analogous except that the participant now had to envision that he or she was a helper in a region recently struck by an earthquake, dispatched to provide 15 urgently needed goods from a nearby town. In line with prior work by our group, samples did not differ in either condition on memory accuracy in a subsequent recognition task. As hypothesized, OCD participants were less certain in their responses for the high responsibility condition than controls. Whereas patients and controls did not differ in their subjective estimates for memorized items, patients expressed stronger doubt that their earthquake mission was successful. The findings indicate that low memory confidence in OCD may only be elicited in situations where perceived responsibility is high and that patients may share higher performance standards ("good is not good enough") than controls when perceived responsibility is inflated.

A new understanding of attention-deficit disorders--beyond the age-at-onset criterion of DSM-IV

For decades, ADHD has been seen primarily as a behavior disorder affecting only young children, primarily boys, causing them to be inattentive and disruptive in school. Research has now established that ADHD affects females as well as males, and that impairing symptoms, for most, persist into adulthood. It has also been shown that this disorder impacts many aspects of life that extend well beyond problems in school. This disorder impairs not only one's ability to sit still and listen, but also the capacity to organize tasks and materials, to sustain effort on tasks, and to utilize short-term memory for daily activities. Studies of children, adolescents, and adults with ADHD indicate that many suffer from a variety of cognitive impairments that extend beyond symptoms listed in the DSM-IV diagnostic criteria for ADHD. These include chronic problems in regulating alertness, in reading comprehension, and in modulating emotions, that occur more frequently in persons with ADHD than in the general population. This article describes recent research findings demonstrating the wide range of cognitive impairments associated with ADHD, which are related to a new model of ADHD, such as developmental impairment of executive functions of the brain.

Cellular profile of cytokine production in a patient with visceral leishmaniasis: gammadelta+ T cells express both type 1 cytokines and interleukin-10

The cytokine profile of CD4+, CD8+ T cells, gammadelta+ T cells and natural killer (NK) cells (CD94+CD3-) was studied in a patient with visceral leishmaniasis (VL). The otherwise healthy, human immunodeficiency virus-negative patient acquired the disease in Tuscany, Italy. Diagnosis was made by demonstration of high concentrations of antibodies against Leishmania antigens in serum. Flow cytometry for the detection of intracellular interferon-gamma (IFN-gamma), interleukin (IL)-2, IL-4, IL-6, IL-10, IL-13 and tumour necrosis factor (TNF)-alpha expression in peripheral blood mononuclear cells stimulated with phorbol 12-myristate 13-acetate and ionomycin was performed, followed by treatment with liposomal amphotericin B. CD4+ cells were identified as major cytokine-expressing cells, capable of producing both type 1 and type 2 cytokines. A high frequency of IL-4- and IL-13-expressing CD8+ cells was noted. NK cells and gammadelta+ T cells, thought to be involved in innate host defences against Leishmania, expressed IFN-gamma and TNF-alpha. Ten per cent of gammadelta+ T cells expressed IL-10, predominantly together with IFN-gamma, suggesting additional immune-regulatory roles for this T-cell subset in VL.

Neutralizing increases discomfort associated with obsessional thoughts: An experimental study with obsessional patients

Cognitive-behavioral theories suggest that the development of neutralizing is crucial in the development and persistence of obsessional problems (OCD). Twenty-nine patients with a Diagnostic and Statistical Manual of Mental Disorders (4th ed., American Psychiatric Association, 1994) diagnosis of OCD were randomly allocated to 2 conditions. Both listened to repeated recorded presentations of their intrusive thoughts and either neutralized (experimental group) or distracted themselves (control). Discomfort was rated during this 1st phase and then during a 2nd phase without neutralizing or distraction. The experimental group showed a similar level of discomfort in the 1st phase, which significantly reduced during the period compared with controls. The experimental group experienced significantly more discomfort during the 2nd phase, and significantly stronger urges to neutralize and distract at the end of this phase than controls.

Immunological tolerance to inhaled antigen

Regulatory mechanisms exist in the immune system to limit the induction of pathogenic responses to antigens encountered within the respiratory tract. The development of allergic disease is thought to arise as a result of the breakdown in these regulatory processes. In this review we examine the nature of immune responses generated to inhaled protein antigens and the mechanisms used to establish tolerance to inhaled antigens.

Mental rotation, memory scanning, and the central bottleneck

Two reaction-time experiments using the psychological refractory period paradigm examined whether two prominent tasks, i.e., mental rotation and memory scanning, require access to a single-channel mechanism and must therefore be performed sequentially with other operations requiring the same mechanism. On each trial, subjects made speeded responses to a tone (Exp. 1) or a character (Exp. 2, with symbolic SR-compatibility of the character manipulated) as Task 1 and to a letter (for blocks with mental rotation) or a digit (for blocks with memory scanning) as Task 2. The set-size effect was constant across SOAs, suggesting that memory scanning cannot be performed in parallel with response selection of Task 1. The effect of orientation, however, decreased with decreasing SOA. The decrease was even intensified if Task 1 bottleneck processes were prolonged by symbolic SR-compatibility. The exact pattern of underadditivity, however, was not predicted by current theories of dual-task performance. The results contradict a central bottleneck model but are in line with extensions of the model proposed by Meyer and Kieras.

Insulin concentrations and time-action profiles of three different intermediate-acting insulin preparations in nondiabetic volunteers under glucose-controlled glucose infusion technique

This study describes the pharmacokinetics of three intermediate-acting insulin preparations, NPH porcine insulin, NPH human insulin (recombinant DNA), and "Depot-A" insulin, a mixture of 20% regular and 80% NPH human insulin from Eli Lilly and Company. Metabolic healthy normal weight volunteers were selected for the study. After overnight fasting, each test person received 0.4 U of each insulin per kg body weight injected subcutaneously in the triceps area of the arm. To prevent severe hypoglycemia, the test persons were connected to a "GCIIS Biostator" with blood glucose clamp at the 60 mg/dl level. Peripheral blood was sampled at regular intervals for glucose, insulin, and C-peptide determination. More elevated insulin levels were measured after application of both NPH human insulin and "Depot-A" insulin than after NPH porcine insulin. A more rapid decrease in the blood glucose concentration was observed after injection of both human insulin preparations than after porcine insulin. The dextrose output of the "GCIIS Biostator" was more pronounced in both human insulins than after the porcine preparation. After the injection of NPH human and NPH porcine insulin, significant differences were calculated between the concentrations of these two insulins in the blood, from the 2nd to the 10th hour (P less than 0.05-P less than 0.005) and between the dextrose output of the "GCIIS Biostator" from the 3rd to the 8.5th hour (P less than 0.05). The fall of the C-peptide concentration to the lower detection limit of the assay reflects suppression of the endogenous B-cell secretion and confirms the measure of peripheral insulin concentrations as a result of the exogenously applied insulin. Although all investigations were performed under identical experimental conditions and equal dosages of each insulin were injected, higher insulin concentrations and a stronger biologic effect, shown by larger amount of dextrose delivered, were observed in both human insulins than in porcine insulin. Why this phenomenon occurs is as yet unclear. The clamp technique used with the "GCIIS Biostator" enables establishment of the biologic profile of any insulin, and thus represents a valuable tool in comparative studies.

Pharmacokinetics of biosynthetic human insulin and characteristics of its effect

In the last 2 years we have developed a new method for determining insulin biologic activity with the help of the glucose-controlled insulin infusion system (GCIIS). Primarily this closed-loop system infuses insulin. But to prevent hypoglycemia, it can in addition, infuse glucose below a certain blood glucose minimum. This effect is used to reproduce insulin biologic activity. After subcutaneous injection of the insulin to be tested in healthy persons (not in insulin-dependent diabetic subjects), the blood glucose level falls, and this is checked by the counterregulatory glucose delivery from the apparatus. The time and intensity of glucose delivery from the GCIIS reflect the insulin effect, so that each insulin manifests its own particular biologic activity.

[Pharmacokinetics of insulin administered intraperitoneal in a bolus form (author's transl)]

Although carbohydrate-intake and subcutaneous insulin injection in the insulin dependent diabetics are brought to match with one another, there is often an incongruity between the momentary insulin need and the actual insulin supply, because insulin is resorbed relatively slow from the subcutaneous injection site. While the plasma insulin concentration in healthy persons after carbohydrate-intake reaches its maximum after ca. 45 min, the maximum insulin concentration after subcutaneous application of regular insulin is observed only after ca. 2 h. For this reason, we studied whether a faster rise in the insulin concentration can be obtained by intraperitoneal bolus application of insulin. 5 metabolic healthy volunteers received 20 UI regular insulin diluted in isotonic saline solution injected intraperitoneal. The insulin concentration in the peripherovenous system was examined. In order to prevent severe hypoglycaemia the test persons were connected to a Biostator (so-called artificial Beta-cell), which delivered glucose automatically when the blood glucose concentration fell below the 60 mg/dl - level, and thus avoided a drastic fall of the blood glucose. A rapid increase in the plasma insulin concentration was observed within a few minutes after the intraperitoneal bolus injection of insulin. After ca. 20 min the maximal insulin concentration was reached. Already after ca. 2 h the plasma insulin levels fell off and approached the initial values. Consequently, the changes of insulin concentration after intraperitoneal bolus application of insulin correspond widely to the insulin curve characteristic of metabolic healthy persons after carbohydrate-intake. Thus, the intraperitoneal bolus injection of insulin presents a mode of application, which must be pursued further in the treatment of insulin dependent diabetics.

Innervated temporal-muscle mastoid flaps

Histological comparisons have been made of predicted temporal-muscle flaps with and without an intact nerve supply. The viability of the musculoplasty depends on maintenance of the neural bundle.