Marinobufagenin stimulates fibroblast collagen production and causes fibrosis in experimental uremic cardiomyopathy

We have observed recently that experimental renal failure in the rat is accompanied by increases in circulating concentrations of the cardiotonic steroid, marinobufagenin (MBG), and substantial cardiac fibrosis. We performed the following studies to examine whether MBG might directly stimulate cardiac fibroblast collagen production. In vivo studies were performed using the 5/6th nephrectomy model of experimental renal failure (PNx), MBG infusion (MBG), PNx after immunization against MBG, and concomitant PNx and adrenalectomy. Physiological measurements with a Millar catheter and immunohistochemistry were performed. In vitro studies were then pursued with cultured isolated cardiac fibroblasts. We observed that PNx and MBG increased MBG levels, blood pressure, heart size, impaired diastolic function, and caused cardiac fibrosis. PNx after immunization against MBG and concomitant PNx and adrenalectomy had similar blood pressure as PNx but less cardiac hypertrophy, diastolic dysfunction, and cardiac fibrosis. MBG induced increases in procollagen-1 expression by cultured cardiac fibroblasts at 1 nM concentration. These increases in procollagen expression were accompanied by increases in collagen translation and increases in procollagen-1 mRNA without any demonstrable increase in procollagen-1 protein stability. The stimulation of fibroblasts with MBG could be prevented by administration of inhibitors of tyrosine phosphorylation, Src activation, epidermal growth factor receptor transactivation, and N-acetyl cysteine. Based on these findings, we propose that MBG directly induces increases in collagen expression by fibroblasts, and we suggest that this may be important in the cardiac fibrosis seen with experimental renal failure.     

EUS-FNA as the initial diagnostic modality in centrally located primary lung cancers

BACKGROUND AND AIMS: The need to safely and accurately diagnose lung neoplasms is crucial as the only prospect for a cure is surgical resection. A small amount of data exists on the use of endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) as the initial diagnostic modality of primary lung cancer. METHODS: We performed a retrospective review of an established prospective database of all patients undergoing EUS-FNA of a primary lung neoplasm adjacent to the esophagus during January 2001 to August 2005 in one tertiary care center. The indications for the procedure, diagnostic accuracy, and complications were reviewed. RESULTS: A total of 17 cases (9 females, 8 males) were identified. The mean age was 66 (SD 10.6). There were 9 lesions within the hilum and 8 lesions within the upper lobes. The median size of the lung lesions was 5 (range 2 to 12)x4 (range 2 to 9) cm. The median and mean number of FNA passes was 3. All the procedures provided an accurate diagnosis of the primary lung lesion without need for further intervention. One patient with active hemoptysis was transiently hospitalized for aspiration pneumonia postprocedure. CONCLUSIONS: EUS-FNA is a safe, relatively cost-effective, and accurate initial diagnostic modality for the diagnosis of lung lesions adjacent to the esophagus or invading the mediastinum. Although further randomized prospective trials are warranted, this modality should be considered as a first step in the diagnostic armamentarium in centrally located lung lesions.     

Outcome measurements in scleroderma: results from a delphi exercise

OBJECTIVE: To obtain a consensus on the minimal clinically relevant treatment effect in various scleroderma disease outcome measures to be used in future clinical trials. METHODS: A Delphi consensus building exercise using a survey was sent out to members of the Scleroderma Clinical Trials Consortium (SCTC). The 65 SCTC members were divided into 2 groups. Group 1 was informed, in a cover letter, of the usual American College of Rheumatology 20% response results in randomized trials using effective biologic treatments for rheumatoid arthritis, while Group 2 was not. The first round of the exercise presented the scleroderma experts with a survey composed of 95 questions/clinical scenarios divided into 8 categories. These included situations where the treatment group improved, or worsened, or where some outcome measures improved, while others worsened. From the responses of this first round, a mean, mode, median, and range of responses for each of the 95 questions was obtained. This information was sent out, in the second round of the Delphi exercise, only to those respondents who answered the first round. The respondent's previous answer and the mean and range from the first round were provided for each question. It gave respondents the option to change any of their initial responses. The median of their responses in the second round was used to calculate the values for the minimal clinically relevant treatment effect. RESULTS: Thirty-two of the 65 SCTC members returned the first round of the Delphi exercise. Twenty-eight members returned the second round. Intraclass correlation coefficients between responses to round 1 and 2 were calculated for the questions. These varied from 0.99 (excellent agreement) to 0.02 (poor agreement). The p value was under 0.09 for 9 questions and under 0.19 for 20 questions. Standard deviations (SD) were calculated and were found to be lesser for each of the questions in round 2 when compared to the SD in responses from round 1, thus indicating a movement towards a consensus by the second round. An average of 33% of the responses were changed by the respondents in the second round of the Delphi exercise to a value closer to the median/average of the first round's responses. A range in required values for the minimal clinically relevant treatment effect for Modified Rodnan skin score is 3 to 7.5 units, Health Assessment Questionnaire Disability Index (HAQ-DI) 0.2 to 0.25 units, HAQ pain 0.2 to 0.3 units, MD global (100 mm visual analog scale) 8 to 13, patient global assessment 10 to 12, and diffusing capacity (percentage predicted) 9 to 10. The scenarios were especially weighted towards overall disease modification, thus organ-specific measures, such as 6 minute walk time (which has been used in many pulmonary artery hypertension trials), forced vital capacity, and a dyspnea rating (which may be important in scleroderma lung trials), were not included in the survey. CONCLUSION: Our study begins to address the current deficiency in our knowledge of appropriate values for the minimal clinically relevant treatment effect in various scleroderma disease outcome measures. A consensus could be achieved, or at least a range of minimal clinically relevant treatment effect values could be found for several outcome measurements. Of course, this consensus statement will be modified by evidence as it accrues in each consensus area.     

Surgical resection after gefitinib treatment in patients with lung adenocarcinoma harboring epidermal growth factor receptor gene mutation

Gefitinib is the first approved epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI) for the treatment of patients with advanced non-small cell lung cancer (NSCLC) who failed to respond to conventional chemotherapy. Gefitinib has fairly effective anti-tumour activity in patients with tumours harboring EGFR gene mutations. However, there has been no data about the preoperative gefitinib treatment in NSCLC patients. We reported here two cases of surgical resection of residual disease after dramatic response to gefitinib in patients with lung adenocarcinoma harboring EGFR gene mutation. Because both of our patients initially had advanced local tumour burden (bulky N2 disease), complete resection would not have been technically feasible. However, preoperative gefitinib treatment made it possible to achieve complete resection in both patients. We believe that clinical trials are required to evaluate the role of preoperative treatment of EGFR-TKIs in patients with locally advanced NSCLC harboring EGFR gene mutation.     

Acute arterial occlusion after ultrasound-guided thrombin injection of a common femoral artery pseudoaneurysm with a wide, short neck

Ultrasound-guided thrombin injection (UGTI) has emerged as the preferred treatment modality for pseudoaneurysms occurring as a result of percutaneous femoral arterial interventions. UGTI is safe and effective, with few complications. Native arterial thrombosis has been rarely reported in the literature following UGTI and has usually been attributed to excessive thrombin injection. We report a case of femoral arteria thrombosis occurring following UGTI of a 4 cm postcatherization pseudoaneurysm with a wide, short neck successfully treated by surgical intervention. The large size of the neck of this pseudoaneurysm likely contributed to the development of this complication.     

Central role for the cardiotonic steroid marinobufagenin in the pathogenesis of experimental uremic cardiomyopathy

Patients with chronic renal failure develop a "uremic" cardiomyopathy characterized by diastolic dysfunction, cardiac hypertrophy, and systemic oxidant stress. Patients with chronic renal failure are also known to have increases in the circulating concentrations of the cardiotonic steroid marinobufagenin (MBG). On this background, we hypothesized that elevations in circulating MBG may be involved in the cardiomyopathy. First, we observed that administration of MBG (10 microg/kg per day) for 4 weeks caused comparable increases in plasma MBG as partial nephrectomy at 4 weeks. MBG infusion caused increases in conscious blood pressure, cardiac weight, and the time constant for left ventricular relaxation similar to partial nephrectomy. Decreases in the expression of the cardiac sarcoplasmic reticulum ATPase, cardiac fibrosis, and systemic oxidant stress were observed with both MBG infusion and partial nephrectomy. Next, rats were actively immunized against a MBG-BSA conjugate or BSA control, and partial nephrectomy was subsequently performed. Immunization against MBG attenuated the cardiac hypertrophy, impairment of diastolic function, cardiac fibrosis, and systemic oxidant stress seen with partial nephrectomy without a significant effect on conscious blood pressure. These data suggest that the increased concentrations of MBG are important in the cardiac disease and oxidant stress state seen with renal failure.     

Mast cell changes in scleroderma

Objective. To analyze the concentration and distribution of the MC_T (tryptase-positive, chymase-negative) and MC_TC (tryptase-positive, chymase-positive) types of mast cell in cutaneous lesions of scleroderma. Methods. Biopsy specimens were obtained from skin lesions in 24 patients with scleroderma, and subjected to double immunohistochemical analysis using mouse monoclonal anti-tryptase and anti-chymase antibodies. Results. Dermal mast cell concentrations were below the normal range in 12 of the specimens, most of which were obtained between 1 and 4 years after disease onset. All other specimens contained normal concentrations of mast cells. MC_T cells were present in 12 specimens and comprised between 8% and 100% of the total mast cells. Extracellular tissue deposits of tryptasepositive and/or chymase-positive granular material were observed in 8 specimens, suggesting possible mast cell degranulation. Conclusion. These findings are in contrast to those in normal skin, where MC_TC cells are essentially the only type of mast cell present in the dermis. The results suggest that mast cells are involved in the pathogenesis of cutaneous lesions in scleroderma.