Corticosteroids and rituximab as adjunctive treatments for thrombotic thrombocytopenic purpura

Although treatment with plasma exchange increased the survival of patients with thrombotic thrombocytopenia purpura to 80% in the 1980s, no further increase of survival occurred over the next 20 years. However, more consistent use of adjuvant treatment with corticosteroids and rituximab in recent years has begun to further increase survival as well as decrease the frequency of relapse. With adjuvant treatment, durable remissions can be achieved more quickly, requiring fewer days of plasma exchange. Fewer days of plasma exchange have resulted in fewer complications, such as central venous catheter-related systemic infections. Future potential options for adjuvant treatment, recombinant ADAMTS13 to correct severe ADAMTS13 deficiency, and agents to block von Willebrand factor-mediated platelet thrombosis are being investigated.

Vaspin in obesity and diabetes: pathophysiological and clinical significance

Vaspin (visceral adipose tissue-derived serpin; serpinA12) was originally identified as an adipokine, which is predominantly secreted from visceral adipose tissue in Otsuka Long-Evans Tokushima fatty (OLETF), an animal model of obesity and type 2 diabetes. Consistent with that higher vaspin serum concentrations and increased vaspin mRNA expression in human adipose tissue were found to be associated with obesity, insulin resistance, and type 2 diabetes in humans. However, the mechanisms how vaspin secretion may be linked to deterioration of glucose metabolism and insulin sensitivity are not entirely understood. Vaspin serum concentrations show a food intake-related diurnal variation. Vaspin is also expressed in the skin, hypothalamus, pancreatic islets, and stomach. Administration of vaspin to obese mice improves glucose tolerance, insulin sensitivity, and reduces food intake. Until now molecular target(s) of vaspin and its mode of action are unknown. Thus, identification of the proteases, which are inhibited by vaspin may lead to the development of novel strategies in the treatment of obesity, diabetes and insulin resistance. This review discusses the clinical relevance of vaspin in the pathophysiology of obesity and type 2 diabetes.

Correlations between serial pro-gastrin-releasing peptide and neuron-specific enolase levels, and the radiological response to treatment and survival of patients with small-cell lung cancer

INTRODUCTION

To investigate whether decrease in the serum levels of pro-gastrin releasing peptide (ProGRP) and neuron-specific enolase (NSE) were correlated with the radiological response in patients with small-cell lung cancer (SCLC).

METHODS

Of the 196 patients, we retrospectively reviewed 118 patients elevated baseline levels of ProGRP and NSE prior to the initial therapy (IT) who survived for more than 1 month. The radiological response was assessed by Response Evaluation Criteria in Solid Tumors (RECIST 1.1).

RESULTS

Decrease in the serum ProGRP was strongly correlated with the decrease of the sum of the tumor diameters (SOD) before the third course (ρ=0.50) and after the fourth course (ρ=0.42) of IT. Decrease in the serum NSE was weakly correlated with the decrease of the SOD after the fourth course (ρ=0.27), but not before the third courses (ρ=0.22). In the receiver operating characteristic (ROC) curves predicting 1-year survivors, the area under the curve (AUC) for percent changes in serum ProGRP before the third course were significantly larger than those for NSE (0.714 vs. 0.527, p=0.004).

CONCLUSIONS

Percent changes in serum ProGRP showed better correlation to SOD and prognostic impact than that of NSE.

Comparison of a rapid diagnostic test and microimmunofluorescence assay for detecting antibody to Orientia tsutsugamushi in scrub typhus patients in China

OBJECTIVE

To evaluate the detection of IgM and IgG antibodies to Orientia tsutsugamushi (O. tsutsugamushi) by rapid diagnostic test (RDT) and microimmunofluorescence assay (mIFA).

METHODS

RDT using a mixture of recombinant 56-kDa proteins of O. tsutsugamushi and mIFA assay were performed on 20 patients from Fujian and 13 patients from Yunnan Province, and 82 sera samples from healthy farmers in Anhui Province and Beijing City in 2009. Comparison of the RDT and mIFA assay was performed by using X(2) test and the P level of <0.05 was considered to be significance.

RESULTS

Among these 82 normal sera samples, the specificity of RDT was 100% for both IgM and IgG tests. In 33 samples from patients with scrub typhus, 5 cases were positively detected earlier by RDT than by mIFA in IgM test, and 2 cases were positive in IgG test. Sensitivities of RDT were 93.9% and 90.9% for IgM and IgG, respectively. The sensitivity of combination test of IgM and IgG was 100%. Geometric mean titer diluted sera from confirmed cases by IFA and RDT assay were 1:37 vs. 1:113 (P<0.001) in IgM test and 1:99 vs. 1:279 (P<0.05) in IgG test.

CONCLUSIONS

RDT is more sensitivite than mIFA in the early diagnosis of scrub typhus and it is particularly applicable in rural areas.

New detection methods of growth hormone and growth factors

Human growth hormone (GH), but also GH related growth factors like the insulin-like growth factor-1 (IGF-1) are known to be abused in sports. Although the scientific evidence supporting a distinct effect of GH on performance in healthy trained subjects is limited, it has been repeatedly found with athletes or trainers, and the recent introduction of a first test to detect GH doping has led to a number of positive cases. Currently, there is no test for the detection of IGF-1 introduced worldwide, but confiscation of the drug from sports teams can be taken as indirect evidence for its abuse. The major biochemical difficulty for the detection of GH is that the recombinant form is identical in physicochemical properties to the endogenous GH secreted by the pituitary gland. Furthermore, the very short half-life of GH in circulation inherently shortens the window of opportunity where the drug can be detected. Two strategies have been followed for more than a decade to develop a test to detect the application of recombinant GH: the marker approach, which is based on the elevation of GH-dependent markers above the level seen under physiological conditions evoked by administration of recombinant GH, and the isoform approach, which is based on a change in the pattern of GH isoforms in circulation following the injection of recombinant GH.

Renin inhibitors inhibited the activity of recombinant human renin but not activity in healthy human plasma

BACKGROUND

Activity of renin substrate cleavage (renin-like activity) was measured in vitro in plasma samples obtained from healthy human volunteers.

METHODS

Renin-like activity was determined using FRET (Fluorescence Resonance Energy Transfer) human renin substrate. Recombinant human renin and human plasma showed dose-dependent cleavage activity of FRET human renin substrate.

RESULTS

Activity of recombinant human renin was completely inhibited by either a peptidergic or a non-peptidergic renin inhibitor. However, renin-like activity in human plasma was not inhibited by these renin inhibitors. In a mixture of recombinant renin and human plasma, renin inhibitors inhibited only that part of the activity caused by recombinant renin, while the activity in plasma still remained. Human plasma did not show cleavage activity of rat FRET renin substrate. Native human prorenin showed cleavage activity of human renin substrate. This activety was also completely inhibited by renin inhibitors. Immunoprecipitation with anti-renin or anti-prorenin antibodies did not reduce the activity in human plasma. Renin-like activity in human plasma was abolished by degeneration of protein when sample was heated to 95 degrees C. Activity of both recombinant renin and human plasma was significantly inhibited by a protease inhibitor cocktail.

CONCLUSIONS

These results suggest that the activity of renin substrate cleavage in human plasma is not mainly caused by the renin or prorenin molecule, but probably by other proteases.

Successful diagnosis of a combined thymic epithelial tumor by endobronchial ultrasound-guided transbronchial needle aspiration

INTRODUCTION

Endobronchial ultrasound-guided tranbronchial needle aspiration (EBUS-TBNA) can be applied to not only the determination of the clinical stages of lung cancer, but also the diagnosis of lymphadenopathies such as lymphoma and sarcoidosis.

CASE REPORT

We report the successful diagnosis of a combined thymic epithelial tumor in a 68-year-old female by EBUS-TBNA. The patient presented with a 6-month history of dysesthesia in bilateral legs. Chest computed tomography revealed a 5.5 cm-tumor with heterogeneous enhancement in the superior and anterior mediastinum. The serum levels of ProGRP and NSE were elevated and anti-Hu antibody was positive at the time of diagnosis. A biopsy by EBUS-TBNA revealed histological evidence of a combined thymic epithelial tumor consisting of small cell neuroendocrine carcinoma and thymic carcinoma. Chemo-radiotherapy reduced the tumor remarkably in size, but the patient's neurologic symptoms remained.

CONCLUSION

This case suggests that EBUS-TBNA is a safe and useful technique for the diagnosis of paratracheal mediastinal tumors.

Influence of HCV genotype 1 subtypes on the virus response to PEG interferon alpha-2a plus ribavirin therapy

New factors that influence the viral response in HCV non-genotype 2/3 patients must be identified in order to optimize anti-HCV treatment. This multicenter prospective study evaluates the influence of HCV variability and pharmacological parameters on the virological response of these patients to pegylated interferon α2a (peg-IFN-α2a: 180 µg/week) and ribavirin (RBV; 800-1,200 mg/day) for 48 weeks. HCV subtypes were identified by sequencing the NS5B region. Serum RBV and peg-IFN-α2a concentrations were measured at weeks 4 and 12. The 115 patients (67 men; median age = 49, range 31-76) included 64 who had never been treated and 27 co-infected with HIV. The mean baseline HCV RNA was 6.30 ± 0.06 log IU/ml and the HCV genotypes were: G1 (n = 93) with 1a (n = 37) and 1b (n = 50), G4 (n = 20) and G5 (n = 2). Most patients (79/108; 73%) had an early virological response. Independent predictors of an early virological response were interferon naive patients (OR=  2.98, 95% CI: 1.15-7.72) and RBV of >2,200 ng/ml at week 12 (OR = 3.41, 95% CI: 1.31-8.90). Forty of 104 patients (38%) had a sustained virological response. The only independent predictors of a sustained virological response were subtype 1b (OR = 6.82, 95% CI: 1.7-26.8), and HCV RNA <15 IU/ml at week 12 (OR = 25, 95% CI: 6.4-97.6). Thus a serum RBV concentration of >2,200 ng/ml was associated with an early virological response and patients infected with HCV subtype 1b had a better chance of a sustained virological response than did those infected with subtype 1a.

Effects of erythropoietin on frataxin levels and mitochondrial function in Friedreich ataxia--a dose-response trial

Friedreich ataxia (FRDA) is an autosomal recessive inherited neurodegenerative disorder leading to reduced expression of the mitochondrial protein frataxin. Previous studies showed frataxin upregulation in FRDA following treatment with recombinant human erythropoietin (rhuEPO). Dose-response interactions between frataxin and rhuEPO have not been studied until to date. We administered escalating rhuEPO single doses (5,000, 10,000 and 30,000 IU) in monthly intervals to five adult FRDA patients. Measurements of frataxin, serum erythropoietin levels, iron metabolism and mitochondrial function were carried out. Clinical outcome was assessed using the "Scale for the assessment and rating of ataxia". We found maximal erythropoietin serum concentrations 24 h after rhuEPO application which is comparable to healthy subjects. Frataxin levels increased significantly over 3 months, while ataxia rating did not reveal clinical improvement. All FRDA patients had considerable ferritin decrease. NADH/NAD ratio, an indicator of mitochondrial function, increased following rhuEPO treatment. In addition to frataxin upregulation in response to continuous low-dose rhuEPO application shown in previous studies, our results indicate for a long-lasting frataxin increase after single high-dose rhuEPO administration. To detect frataxin-derived neuroprotective effects resulting in clinically relevant improvement, well-designed studies with extended time frame are required.

Hepatoprotective effects of IL-22 on fulminant hepatic failure induced by d-galactosamine and lipopolysaccharide in mice

Interleukin-22 (IL-22), a member of the IL-10 cytokine family that is produced by activated Th22, Th1 and Th17 cells as well as natural killer cells, plays an important role in increase of innate immunity, protection from damage and enhancement of regeneration. Here, we examined the effects of IL-22 on acute liver failure model induced by d-galactosamine (GalN) and lipopolysaccharide (LPS). Administration of recombinant human IL-22 (rhIL-22) reduced the death rate markedly and prevented mice from severe hepatic injury, as evidenced by decreased serum alanine aminotransferase (ALT) and total bilirubin (T.Bil) activity as well as improved histological signs in liver. Furthermore, IL-22 treatment decreased the hepatic malondialdehyde (MDA) contents and increased the reduced glutathione levels. Serum tumor necrosis factor α (TNF-α) level and hepatic caspase-3 activity were significantly lower in mice administrated with IL-22. Moreover, IL-22 treatment significantly enhanced activation of STAT3 and up-regulated the expression of Bcl-xL, heme oxygenase-1 (HO-1) and redox factor-1 (Ref-1) in the liver injury induced by GalN/LPS. Collectively, these data indicate that IL-22 can provide critical protection against GalN/LPS-induced liver injury through anti-apoptotic, anti-oxidant and anti-inflammatory actions.

Prolonged circulation and in vivo efficacy of recombinant human granulocyte colony-stimulating factor encapsulated in polymeric micelles

To improve the pharmacokinetics of granulocyte colony-stimulating factor (G-CSF) and decrease dosing frequency, polyethylene glycol polyglutamate block copolymers were used as delivery carriers. The block copolymers are partially substituted with hydrophobic octyl or benzyl groups to form a micellar structure in aqueous media and encapsulate the protein. G-CSF is encapsulated in the polymeric micelles with a diameter of 60-70nm. The present study was designed to evaluate the plasma pharmacokinetics, G-CSF release and in vivo efficacy of G-CSF-encapsulating micelles. Pharmacokinetic studies in rats showed highly enhanced plasma retention of the micelles compared with native G-CSF. The AUC (area under the curve) of the octyl-based polymer formulation showed a 5-fold increase, compared with native G-CSF. Size-exclusion chromatography of the blood from rats injected with the micelles demonstrated the release of G-CSF from the micelles in the blood circulation. The pharmacokinetic behavior supports the in vivo studies showing that the micelles display a comparable efficacy to PEGylated G-CSF. Simultaneous pharmacokinetic analysis of released and encapsulated G-CSF plasma levels showed that the G-CSF release occurs with the first-order kinetics and the half-life is 4.8h. In conclusion, G-CSF is endowed by the polymeric micelles with prolonged half-life and increased efficacy without any chemical modification.

Diagnostic value of tumor marker pro-gastrin-releasing peptide in patients with small cell lung cancer: a systematic review

BACKGROUND

Lung cancer is one of the most common malignancies in the world and one of the leading cancers that result in death. The aim of this study was to evaluate and compare the diagnostic value of the serum tumor marker pro-gastrin-releasing peptide 31-98 (ProGRP31-98) to pathological diagnosis as reference standard in patients with suspected small cell lung cancer (SCLC).

METHODS

Literature searches covering 1978 through to 2009 were performed in Pubmed, OVID, MEDLINE, EMbase, Cancerlit, China National Knowledge Infrastructure (CNKI), and CBM using the key search words; 'small cell lung cancer', 'tumor marker', 'ProGRP31-98' and 'diagnostic tests', 'ELISA', 'EIA' and 'diagnostic accuracy'. Studies were collected and data analyzed to evaluate the diagnostic value of serum ProGRP31-98 levels for the diagnosis of SCLC compared with pathology. Eligibility criteria for inclusion in the analysis were based on criteria for diagnostic research published by the Cochrane Screening and Diagnostic Tests

METHODS

Group (SDTMG). The characteristics of the included articles were appraised and the data were extracted from the original articles for further statistical analysis of study heterogeneity using Review Manager 4.2 software. Based on study heterogeneity analysis, a suitable 'effect' model was selected to calculate pooled sensitivity and specificity by meta-analysis. A Summary Receiver Operating Characteristic (SROC) curve and the area under the curve (AUC) were generated and sensitivity analysis conducted.

RESULTS

A total of 22 articles were entered into this meta-review, including 11 English articles with a quality at level C. In total, the studies involved 6759 subjects, of which 1470 were diagnosed with SCLC by pathology, and 5289 subjects diagnosed with non-SCLC (NSCLC). The meta-analysis showed that heterogeneity among studies was high (P = 0.00001, I(2) = 86.8%). With ELISA, the pooled sensitivity was 0.72 (0.70 to 0.75 at 95%CI) and the pooled specificity was 0.93 (0.92 to 0.94 at 95%CI); the SROC and the AUC were 0.8817. These data suggest that ProGRP31-98 has a relatively high rate of missed diagnosis (28%), but a relatively low rate of misdiagnosis (7%).

CONCLUSION

From meta-analysis, we concluded that serum ProGRP31-98 is a valuable marker with a high specificity for diagnosis of SCLC with a similar diagnostic accuracy to pathology.

Plasma proGRP concentration is sensitive and specific for discriminating small cell lung cancer from nonmalignant conditions or non-small cell lung cancer

To date, most clinical data on pro-gastrin-releasing peptide (proGRP) have been based on serum concentrations. This study evaluated the agreement between proGRP levels in fresh serum and plasma in patients with various lung diseases. Pairs of serum and EDTA plasma were collected from 49 healthy individuals. At the same time, EDTA plasma of 118 lung cancer patients and 23 patients with benign pulmonary diseases were prospectively collected. Compared to serum, plasma proGRP concentrations were higher by an average of 103.3%. Plasma proGRP was higher in malignancy (336.4 ± 925.4 pg/mL) than in benign conditions (40.1 ± 11.5 pg/mL). Small cell lung cancer (SCLC) patients showed higher levels of proGRP (1,256.3 ± 1,605.6 pg/mL) compared to other types of lung cancer. Based on the ROC curve analyses at a specificity of 95%, the diagnostic sensitivity of plasma proGRP was estimated to be 83.8% in distinguishing SCLC from all the other conditions, and 86.5% for discriminating SCLC from the nonmalignant cases. Among the SCLC cases, limited stage disease had lower levels of plasma proGRP than extensive disease. When measuring circulating levels of proGRP, the use of plasma is preferred over serum. Plasma proGRP has a potential marker for discriminating SCLC from nonmalignant conditions or non-small cell lung cancer.

GH replacement therapy in elderly GH-deficient patients: a systematic review

Context Recombinant human GH (rhGH) is prescribed for the treatment of adults with GH deficiency (GHD). However, conflicting data are available on the efficacy of rhGH treatment in elderly GHD patients. Objective To assess the efficacy of rhGH treatment in elderly GHD subjects. Methods We searched the available literature in PubMed, Cochrane Library, Web of Science and EMBASE. Study selection Studies on GHD patients, aged >60 years, treated with rhGH were eligible for inclusion. Data extraction was performed by two reviewers independently. Results We found 11 eligible studies with a total of 534 patients. Only two studies had prospective, randomized, placebo-controlled study designs of rhGH treatment with a duration of 6 (n=15) and 12 months (n=62), respectively. Treatment with rhGH decreased total and low density lipoprotein (LDL) cholesterol levels by 4-8 and 11-16%, respectively, but did not alter high density lipoprotein or triglyceride levels. RhGH did not affect body mass index, but decreased waist circumference (by ∼3 cm) and waist/hip ratio. RhGh did not consistently affect blood pressure or bone mineral density. RhGH increased lean body mass by 2-5% and decreased total fat mass by 7-10% in four studies, but did not affect body composition in two other studies. RhGH consistently improved quality of life (QoL) parameters reflected in AGHDA-scores. There were no explicit data on elderly GHD patients aged >80 years. Conclusion RhGH replacement in elderly subjects with GHD decreases LDL cholesterol levels and improves QoL, but the effects on other parameters are not unequivocal. There were no data on the efficacy and safety of rhGH treatment in octogenarians with GHD.

Thyroid cancer recurrence in patients clinically free of disease with undetectable or very low serum thyroglobulin values

DESIGN

This was a retrospective clinical study.

SETTING

The study was conducted at a university-based tertiary cancer hospital.

PATIENTS

One hundred seven patients had initial thyroid cancer surgery and subsequent remnant radioiodine ablation. Patients underwent recombinant human TSH (rhTSH)-mediated diagnostic whole-body scan and rhTSH-stimulated thyroglobulin (Tg) measurement before April 2001 if they had no antithyroglobulin antibodies, were clinically free of disease, and had one or more undetectable (≤0.5 ng/ml) or low (0.6-1 ng/ml) basal Tg measurements on levothyroxine. Patients were stratified according to their rhTSH-Tg responses: group 1, Tg 0.5 ng/ml or less (68 patients); group 2, Tg from 0.6 to 2.0 ng/ml (19 patients); and group 3, Tg greater than 2 ng/ml (20 patients).

MAIN OUTCOME MEASURES

Tumor recurrence was measured.

RESULTS

In group 1, two of 62 patients (3%) with follow-up recurred. In group 2, 63% converted to group 1, whereas two of 19 (11%) converted to group 3 and then recurred. Sixteen of the initial 20 group 3 patients (80%) recurred, including recurrence rates of 69 and 100% for those with an initial rhTSH-Tg greater than 2.0 ng/ml but 5.0 ng/ml or less, and 4.6 ng/ml or greater, respectively. One group 3 patient died of distant metastases. rhTSH-Tg more accurately predicted tumor recurrence than basal Tg. An rhTSH-Tg threshold of 2.5 ng/ml or greater optimally predicted future recurrence with sensitivity, specificity, and negative and positive predictive values of 80, 97, 95, and 84%, respectively.

CONCLUSIONS

The prevalence of postablation thyroid cancer recurrence is predicted by the rhTSH-Tg response with an optimal Tg threshold of 2.5 ng/ml. Still, recurrent disease occurs in some patients with an initial rhTSH-Tg of 0.5 ng/ml or less.

Recombinant human thyrotropin in thyroid remnant ablation with 131-iodine in high-risk patients

BACKGROUND

Most patients with well-differentiated thyroid cancer (WDTC) are first treated by total thyroidectomy followed by remnant ablation (RA) with (131)I. There are less data regarding the efficacy of recombinant human thyrotropin (rhTSH) for patients with WDTC at high risk of relapse than for low-risk patients. This study compared the efficacies of rhTSH and thyroid hormone withdrawal (THW) to prepare patients at high risk of relapse for RA.

METHODS

Post-thyroidectomy patients with WDTC and complete tumor resection (n = 275) were studied. They were at high risk of recurrence (tumor size >4 cm and/or extrathyroidal extension [pT3] and/or lymph node metastases), and they did not have antithyroglobulin (Tg) antibodies. Group A (n = 77) received 0.9 mg rhTSH for 2 consecutive days followed by RA on day 3. The remaining 198 patients (group B) were prepared by THW for 4 weeks. Patients in groups A and B received 3.7 or 5.5 GBq (131)I.

RESULTS

The groups were similar in terms of gender, age, histology, TNM (tumor-node-metastases) stage, (131)I activity, and frequency of metastases on post-therapy whole-body scanning (RxWBS). Among patients without metastases on RxWBS, RA was successful (stimulated Tg <1 ng/mL and negative diagnostic whole body scan and neck ultrasonography) in 56 of 70 patients in group A (80%) and in 135 of 169 patients in group B (79.9%). Among patients with Tg >1 ng/mL immediately before RA, the comparable success rates were 68.4% and 67.4%, respectively. Among patients with metastases on the first RxWBS, no uptake was observed on the RxWBS 1 year later in 5 of 7 patients in group A (71.4%) and in 17 of 29 patients in group B (58.6%). The rhTSH stimulated serum Tg was <1 ng/mL in 3 of 5 and in 12 of 17 patients with a second negative RxWBS in groups A and B, respectively. Persistent disease (stimulated Tg >1 ng/mL and RxWBS continuing to show ectopic uptake) occurred in 2 of 7 patients in group A (28.5%) and in 12 of 29 patients in group B (41.3%).

CONCLUSIONS

rhTSH is as effective as THW for RA in patients with WDTC who are at a high risk of relapse.

Obesity is a fibroblast growth factor 21 (FGF21)-resistant state

OBJECTIVE

Fibroblast growth factor 21 (FGF21) is a key mediator of fatty acid oxidation and lipid metabolism. Pharmacological doses of FGF21 improve glucose tolerance, lower serum free fatty acids, and lead to weight loss in obese mice. Surprisingly, however, FGF21 levels are elevated in obese ob/ob and db/db mice and correlate positively with BMI in humans. However, the expected beneficial effects of endogenous FGF21 to increase glucose tolerance and reduce circulating triglycerides are absent in obesity.

RESEARCH DESIGN AND METHODS

To test the hypothesis that obesity is a state of FGF21 resistance, we evaluated the response of obese mice to exogenous FGF21 administration. In doing this, we assessed the impact of diet-induced obesity on FGF21 signaling and resultant transcriptional events in the liver and white adipose tissue. We also analyzed the physiologic impact of FGF21 resistance by assessing serum parameters that are acutely regulated by FGF21.

RESULTS

When obese mice are treated with FGF21, they display both a significantly attenuated signaling response as assessed by extracellular mitogen-activated protein kinase 1 and 2 (ERK1/2) phosphorylation as well as an impaired induction of FGF21 target genes, including cFos and EGR1. These effects were seen in both liver and fat. Similarly, changes in serum parameters such as the decline in glucose and free fatty acids are attenuated in FGF21-treated DIO mice.

CONCLUSIONS

These data demonstrate that DIO mice have increased endogenous levels of FGF21 and respond poorly to exogenous FGF21. We therefore propose that obesity is an FGF21-resistant state.

Acute effects of recombinant human TSH on bone markers in differentiated thyroid cancer

Patients suffering from differentiated thyroid cancer receive suppressive of TSH thyroxine treatment of long duration. This study was undertaken to determine changes on bone serum markers after administration of recombinant human TSH in differentiated thyroid cancer patients on thyroxine treatment. Forty-five patients undergoing diagnostic evaluation of their disease and 48 matched controls were investigated: two injections of 0.9 mg of recombinant human TSH were given to the patients (on days 1 and 2). Blood samples were collected the day before first injection (day 0) and days 3, 5 and 10 after recombinant human TSH administration. Blood samples were obtained for serum TSH, bone alkaline phosphatase, osteocalcin, osteoprotegerin, receptor activator of nuclear factor kB ligand and bone tartrate resistant acid phosphatase. Recombinant human TSH induced a significant increase in bone alkaline phosphatase on day 3 up to day 10 in postmenopausal women. A statistically significant increase was also observed in serum receptor activator of nuclear factor kB ligand in both men and postmenopausal women on day 3 while on day 10 these values returned to baseline levels. No significant effects were seen in other parameters at any time of the investigation. In conclusion, we demonstrated significant increases in receptor activator of nuclear factor kB ligand and bone alkaline phosphatase after TSH stimulation. The changes in these bone indices were more prominent in the group of postmenopausal women.

[Atypical carcinoid of the lung with abnormal elevation of serum ProGRP level; report of a case]

We report a rare case of an atypical carcinoid of the lung with the elevation of serum ProGRP. A 79-year-old female was referred to our hospital presenting with an abnormal shadow by a chest X-ray film. Chest computed tomography (CT) scan revealed a well-defined solitary nodule in the left lower lobe. The serum level of ProGRP was elevated to 2.267 pg/ml (normal range: <46 pg/ml). Pulmonary carcinoid was pathologically suggested by a transbronchial lung biopsy. Considering the patient's general condition, a partial wide resection was performed. Pathological diagnosis was atypical carcinoid. After the operation, further increase of the serum ProGRP level was noted, and multiple liver metastases developed.

Gas6 is complexed to the soluble tyrosine kinase receptor Axl in human blood

BACKGROUND

The vitamin K-dependent Gas6 protein (product of growth arrest specific gene 6) binds to, and activates the TAM receptor tyrosine kinases Tyro3, Axl and Mer. It has been suggested that Gas6 and the TAM receptors are important for primary platelet functions, but Gas6 cannot be found in human platelets. However, Gas6 is present in human plasma at a concentration of around 0.2 nM, which is a thousand-fold lower than that of the homologous protein S. The Axl and Mer receptors can be cleaved close to the cell membrane, yielding soluble molecules consisting of the extracellular parts of the receptors.

OBJECTIVE

To investigate if soluble Axl (sAxl) is present in human serum and plasma and if Gas6 circulates in complex with sAxl.

METHODS

We expressed recombinant sAxl, raised antibodies and developed and validated an ELISA for Axl. Serum and plasma were analyzed using ELISAs for Gas6, Axl and sAxl-Gas6 complexes. Serum was gel filtered and fractions analyzed by the different ELISAs to determine if Gas6 in serum is free or complexed. Immunoprecipitation was used to investigate binding between Gas6 and sAxl in serum.

RESULTS

sAxl is present in serum and plasma at around 0.6 nM and all Gas6 is bound to sAxl. No complexes between Gas6 and the soluble forms of Mer and Tyro3 could be detected, indicating that sAxl is the physiological binder of Gas6 in human serum.

CONCLUSIONS

Gas6 in circulation is bound to sAxl suggesting circulating Gas6 to be inhibited and incapable of stimulating the TAM receptors.

Dabigatran enhances clot susceptibility to fibrinolysis by mechanisms dependent on and independent of thrombin-activatable fibrinolysis inhibitor

BACKGROUND

Anticoagulants are expected to promote fibrinolysis by counteracting the antifibrinolytic effects of thrombin, which include thrombin-activatable fibrinolysis inhibitor (TAFI) activation and clot structure enhancement. However, the efficiency of anticoagulants may vary remarkably, and the ability of direct thrombin inhibitors to facilitate clot lysis remains controversial.

OBJECTIVE

To evaluate the profibrinolytic effect of dabigatran, a new, direct thrombin inhibitor, using different in vitro models.

METHODS AND RESULTS

The resistance of tissue factor-induced plasma clots to fibrinolysis by exogenous tissue-type plasminogen activator (t-PA) (turbidimetric method) was reduced by dabigatran in a concentration-dependent manner, with > or = 50% shortening of lysis time at clinically relevant concentrations (1-2 microm). A similar effect was observed in the presence of low (0.1 and 1 nm) but not high (10 nm) concentrations of thrombomodulin. Acceleration of clot lysis by dabigatran was associated with a reduction in TAFI activation and thrombin generation, and was largely, although not completely, negated by an inhibitor of activated TAFI, potato tuber carboxypeptidase inhibitor. The assessment of the viscoelastic properties of clots showed that those generated in the presence of dabigatran were more permeable, were less rigid, and consisted of thicker fibers. The impact of these physical changes on fibrinolysis was investigated using a model under flow conditions, which demonstrated that dabigatran made the clots markedly more susceptible to flowing t-PA, by a mechanism that was largely TAFI-independent.

CONCLUSIONS

Dabigatran, at clinically relevant concentrations, enhances the susceptibility of plasma clots to t-PA-induced lysis by reducing TAFI activation and by altering the clot structure. These mechanisms might contribute to the antithrombotic activity of the drug.

Human recombinant ACE2 reduces the progression of diabetic nephropathy

OBJECTIVE

Diabetic nephropathy is one of the most common causes of end-stage renal failure. Inhibition of ACE2 function accelerates diabetic kidney injury, whereas renal ACE2 is downregulated in diabetic nephropathy. We examined the ability of human recombinant ACE2 (hrACE2) to slow the progression of diabetic kidney injury.

RESEARCH DESIGN AND METHODS

Male 12-week-old diabetic Akita mice (Ins2(WT/C96Y)) and control C57BL/6J mice (Ins2(WT/WT)) were injected daily with placebo or with rhACE2 (2 mg/kg, i.p.) for 4 weeks. Albumin excretion, gene expression, histomorphometry, NADPH oxidase activity, and peptide levels were examined. The effect of hrACE2 on high glucose and angiotensin II (ANG II)-induced changes was also examined in cultured mesangial cells.

RESULTS

Treatment with hrACE2 increased plasma ACE2 activity, normalized blood pressure, and reduced the urinary albumin excretion in Akita Ins2(WT/C96Y) mice in association with a decreased glomerular mesangial matrix expansion and normalization of increased alpha-smooth muscle actin and collagen III expression. Human recombinant ACE2 increased ANG 1-7 levels, lowered ANG II levels, and reduced NADPH oxidase activity. mRNA levels for p47(phox) and NOX2 and protein levels for protein kinase Calpha (PKCalpha) and PKCbeta1 were also normalized by treatment with hrACE2. In vitro, hrACE2 attenuated both high glucose and ANG II-induced oxidative stress and NADPH oxidase activity.

CONCLUSIONS

Treatment with hrACE2 attenuates diabetic kidney injury in the Akita mouse in association with a reduction in blood pressure and a decrease in NADPH oxidase activity. In vitro studies show that the protective effect of hrACE2 is due to reduction in ANG II and an increase in ANG 1-7 signaling.