Autologous islet transplantation after total pancreatectomy for renal cell carcinoma metastases.

Pancreatic metastases from renal cell carcinoma (RCC) may have a chronic and highly indolent course, and may be resected for cure after considerable delay following treatment of the primary tumor, in contrast to other more common pancreatic tumors. Surgical resection is the treatment of choice, which may lead to postpancreatectomy diabetes mellitus in the case of extensive resection. We present a 70-year-old patient with multifocal pancreatic metastases from RCC causing obstructive jaundice. A total pancreatectomy was required to excise two distant tumors in the head and tail of the pancreas, together with a segment VI liver resection. An autologous islet transplant (AIT) prepared from the central, uninvolved pancreas was carried out to prevent postpancreatectomy diabetes. The patient was rendered insulin-free and remains so with excellent glycemic control for 1 year of follow-up, and there is no evidence of tumor recurrence. The patient has been treated with adjuvant sunitinib to minimize risk of further recurrence. In conclusion, AIT after pancreatectomy may represent a useful option to treat patients with metastatic RCC. A critical component of this approach was dependent upon elaborate additional testing to exclude contamination of the islet preparation by cancerous cells.

Late cytomegalovirus transmission and impact of T-depletion in clinical islet transplantation.

The epidemiology of cytomegalovirus infection (CMV) in islet transplantation (IT) is not well defined. This study defines incidence, transmission and clinical sequelae of CMV reactivation or disease in 121 patients receiving 266 islet infusions at a single institution. The donor (D)/recipient (R) serostatus was D+/R- 31.2%, D+/R+ 26.3%, D-/R+ 13.2% and D-/R- 29.3%. CMV prophylaxis with oral ganciclovir/valganciclovir was given in 68%. CMV infection occurred in 14/121 patients (11.6%); six had asymptomatic seroconversion and eight others had positive viremia (six asymptomatic and two with CMV febrile symptoms). Median peak viral loads were 1755 copies/mL (range 625-9 100 000). Risk factors for viremia included lymphocyte depletion (thymoglobulin or alemtuzumab, p < 0.001). Viremia was more common in D+/R+ versus D+/R- (p = 0.12), occurring mostly late after transplant (median 306 days). Presumed transmission from IT occurred in 8/83 of D+/R- procedures (9.6%). Of the two cases of CMV disease, one resulted from islet transmission from a CMV positive donor (D+/R-); the other was due to de novo exogenous infection (D-/R-). Therefore, CMV transmission presents rarely after IT and with low incidence compared to solid organ transplantation, but occurs late posttransplant. The use of lymphocyte depleting therapies is a primary risk factor.

Thioredoxin reduces post-ischemic myocardial apoptosis by reducing oxidative/nitrative stress.

BACKGROUND AND PURPOSE: Thioredoxin (Trx) is an oxidoreductase that prevents free radical-induced cell death in cultured cells. Here we assessed the mechanism(s) underlying the cardioprotective effects of Trx in vivo. EXPERIMENTAL APPROACH: The effects of myocardial ischemia (30 min) and reperfusion were measured in mice, with assays of myocardial apoptosis, superoxide production, NOx and nitrotyrosine content, and myocardial infarct size. Recombinant human Trx (rhTrx, 0.7-20 mg kg(-1), i.p.) was given 10 min before reperfusion. KEY RESULTS: Treatment with 2 mg kg(-1) rhTrx significantly decreased myocardial apoptosis and reduced infarct size (P<0.01). Nitrotyrosine content of cardiomyocytes was markedly reduced in rhTrx-treated animals (P<0.01). To further identify the mechanisms by which rhTrx may exert its anti-nitrative effect, iNOS expression and production of NOx and superoxide were determined. Treatment with rhTrx had no significant effect on iNOS expression or NOx content in the ischemic/reperfused heart. However, it markedly upregulated mSOD and reduced tissue superoxide content. To further establish a causative link between the anti- peroxynitrite effect and the cardioprotective effect of rhTrx, cultured adult cardiomyocytes were incubated with SIN-1, a peroxynitrite donor, (50 microM for 3 h) resulting in a nitrotyrosine content comparable to that seen in the ischemic/reperfused heart and causing significant cardiomyocyte apoptosis (P<0.01). Treatment with rhTrx markedly decreased SIN-1 induced apoptosis (P<0.01). CONCLUSIONS AND IMPLICATIONS: These results demonstrate that Trx is a novel anti-apoptotic and cardioprotective molecule that exerts its cardioprotective effects by reducing ischemia/reperfusion-induced oxidative/nitrative stress.

Peroxynitrite aggravates myocardial reperfusion injury in the isolated perfused rat heart.

OBJECTIVE: This study examined the effects of peroxynitrite (ONOO-) on cardiac function and cellular injury following ischemia (30 min) and reperfusion (60 min) in isolated perfused rat hearts. METHODS: 3-Morpholinosydnonimine (SIN-1, 0.1 mM), an ONOO- donor, was administered alone or combined with superoxide dismutase (SOD, 300 U/ml) or glutathione (GSH, 1 mM) at the time of reperfusion. RESULTS: Administration of SIN-1 alone significantly aggravated post-ischemic myocardial injury characterized by depressed cardiac function recovery (p < 0.05 vs. vehicle), increased lactic dehydrogenase (LDH) and creatine kinase (CK) release (p < 0.01 vs. vehicle), and enlarged necrotic size (p < 0.01 vs. vehicle). The co-administration of either SOD to decrease the formation of ONOO-, or GSH to increase the detoxification of ONOO-, completely blocked the detrimental effects of SIN-1 and exerted significant cardioprotective effects against reperfusion injury. CONCLUSION: These results suggest that ONOO- may play a significant role in postischemic myocardial injury.

Anti-apoptotic effect of benidipine, a long-lasting vasodilating calcium antagonist, in ischaemic/reperfused myocardial cells.

1. Ischaemia/reperfusion causes intracellular calcium overloading in cardiac cells. Administration of calcium antagonists reduces myocardial infarct size. Recent in vitro studies have demonstrated that calcium plays a critical role in the signal transduction pathway leading to apoptosis. However, whether or not calcium antagonists may reduce myocardial apoptosis induced by ischaemia-reperfusion, and thus decrease myocardial infarction, has not been directly investigated. 2. The present study investigated the effects of benidipine, an L-type calcium channel blocker, on myocardial infarct size, apoptosis, necrosis and cardiac functional recovery in rabbits subjected to myocardial ischaemia/reperfusion (MI/R, 45 min/240 min). Ten minutes prior to coronary occlusion, rabbits were treated with vehicle or benidipine (10 microg x kg(-1) or 3 microg x kg(-1), i.v.). 3. In the vehicle-treated group, MI/R caused cardiomyocyte apoptosis as evidenced by DNA ladder formation and TUNEL positive nuclear staining (12.2+/-1.1%). Treatment with 10 microg x kg(-1) benidipine lowered blood pressure, decreased myocardial apoptosis (6.2+/-0.8%, P<0.01 vs vehicle) and necrosis, reduced infarct size (20+/-2.3% vs 49+/-2.6%, P<0.01), and improved cardiac functional recovery after reperfusion. Administering benidipine at 3 microg x kg(-1), a dose at which no haemodynamic effect was observed, also exerted significant anti-apoptosis effects, which were not significantly different from those observed with higher dose benidipine treatment. However, treatment with this low dose benidipine failed to reduce myocardial necrosis. 4. These results demonstrate that benidipine, a calcium antagonist, exerts significant anti-apoptosis effects, which are independent of haemodynamic changes. Administration of benidipine at a higher dose produced favourable haemodynamic effects and provided additional protection against myocardial necrotic injury and further improved cardiac functional recovery.

Effects of a hydroxylated metabolite of the beta-andrenoreceptor antagonist, carvedilol, on post-ischaemic splachnic tissue injury.

1 Reactive oxygen species have been demonstrated to play a critical role in post-ischaemic tissue injury. The present experiment was designed to evaluate the effects of SB 211475, a hydroxylated metabolite of the new beta-adrenoceptor antagonist, carvedilol, on rat splanchnic ischaemia (SI, 60 min) and reperfusion(R)-induced shock and tissue injury. 2 Administration of SB 211475 two min before R attenuated SI/R injury in a dose-dependent manner. At doses of 0.5 mg kg(-1) and 1.0 mg kg(-1), SB 211475 exerted significant anti-shock and endothelial protective effects, characterized by prolonged survival times, increased survival rates, attenuated increases in tissue myeloperoxidase activity and haematocrits, and preserved endothelium-dependent vasorelaxation. 3 Administration of 1 mg kg(-1) carvedilol attenuated shock-induced tissue injury and endothelial dysfunction. However, administration of 0.5 mg kg(-1) carvedilol had no protective effects on post-ischaemic tissue injury. 4 Previous studies have shown that SB 211475 has virtually no beta-blocking activity but possesses more potent antioxidant activity than carvedilol. In the present study, SB 211475 exerted more potent protective effects than the parent compound, suggesting that this metabolite of carvedilol is superior to carvedilol with regard to its protection against post-ischaemia tissue injury.

L-propionyl carnitine, an endogenous ester in fatty acid metabolism, exerts anti-shock and endothelial protective effects in rat splanchnic ischemia-reperfusion injury.

Splanchnic artery occlusion (SAO) results in a severe form of circulatory shock in which oxygen-derived free radicals play an important role. L-Propionyl carnitine (LPC), an endogenous ester that plays a crucial role in cellular fatty acid oxidation and metabolism, has been shown to exert a protective effect in myocardial ischemia/reperfusion injury. Our purpose was to investigate the effects of LPC in an SAO model of ischemia/reperfusion injury. Pentobarbital-anesthetized rats were subjected to 60 min of SAO followed by 120 min of reperfusion. An intravenous bolus of LPC (200 microg/kg) administered 2 min before reperfusion prolonged survival time (116+/-4 vs. 81+/-3 min in 1 mL/kg .9% NaCl vehicle, p < .01), increased survival rate (88 vs. 13.6%, p < .01), and attenuated the percent increase in hematocrits (27+/4% vs. 43+/-3%, p < .05), and the increases in tissue myeloperoxidase activity (1.76+/-.4 U/100 mg vs. 3.79+/-.2 U/100 mg, p < .05). In addition, LPC increased mean arterial blood pressures at 60 min (p < .05), 80 min (p < .05), 100 min (p < .05), and 120 min (p < .05) postreperfusion. Moreover, LPC markedly attenuated splanchnic artery endothelial dysfunction induced by SAO ischemia/reperfusion injury (maximal vasorelaxation to ACh, 74+/-2.7% vs. 57+/-1.9% in vehicle, p < .01). In this murine SAO model of ischemia/reperfusion injury, LPC affords significant protection that may be achieved through inhibiting leukocyte infiltration into intestinal tissue and preserving endothelial function, thereby decreasing microvascular permeability and maintaining tissue perfusion.

Comparison of bisoprolol and carvedilol cardioprotection in a rabbit ischemia and reperfusion model.

Carvedilol, a selective alpha(1) and non-selective beta-adrenoceptor antagonist and antioxidant, has been shown to provide significant cardiac protection in animal models of myocardial ischemia. To further explore the mechanisms contributing to the efficacy of carvedilol cardioprotection, the effects of carvedilol on hemodynamic variables, infarct size and myeloperoxidase activity (an index of neutrophil accumulation) were compared with a beta(1) selective adrenoceptor antagonist, bisoprolol. Carvedilol (1 mg/kg) or bisoprolol (1 mg/kg) was given intravenously 5 min before reperfusion. In vehicle-treated rabbits, ischemia (45 min) and reperfusion (240 min) resulted in significant increases in left ventricular end diastolic pressure, large myocardial infarction (64.7+/-2.6% of area-at-risk) and a marked increase in myeloperoxidase activity (64+/-14 U/g protein in area-at-risk). Carvedilol treatment resulted in sustained reduction of the pressure-rate-index and significantly smaller infarcts (30+/-2.9, P<0.01 vs. vehicle) as well as decreased myeloperoxidase activity (26+/-11 U/g protein in area-at-risk, P<0.01 vs. vehicle). Administration of bisoprolol at 1 mg/kg resulted in a pressure-rate-index comparable to that of carvedilol and also decreased infarct size (48.4+/-2.5%, P<0.001 vs. vehicle, P<0.05 vs. carvedilol), although to a significantly lesser extent than that observed with carvedilol. Treatment with bisoprolol failed to reduce myeloperoxidase activity in the ischemic myocardial tissue. In addition, carvedilol, but not bisoprolol, markedly decreased cardiac membrane lipid peroxidation measured by thiobarbituric acid formation. Taken together, this study suggests that the superior cardioprotection of carvedilol over bisoprolol is possibly the result of carvedilol's antioxidant and anti-neutrophil effects, not its hemodynamic properties.

Peroxynitrite, the product of nitric oxide and superoxide, causes myocardial injury in the isolated perfused rat heart.

BACKGROUND: Recent studies have determined that the product of NO and superoxide is peroxynitrite (ONOO-), an anion with deleterious tissue-oxidant effects. OBJECTIVE: To examine the effects of ONOO- on the isolated perfused rat heart. Sprague-Dawley rat hearts were perfused with a cell-free, Krebs-Henseleit solution on a Langendorf perfusion apparatus. The hearts were subjected to 30 min infusions of vehicle (control); 10 mumol/l S-nitroso-N-acetylpenicillamine (SNAP), an NO donor; 10 mumol/l pyrogallol, a superoxide generator); 10 mumol/l SNAP plus 10 mumol/l pyrogallol, a mixture that generates peroxynitrite; or 10 mumol/l SNAP plus 10 mumol/l pyrogallol plus 300 U/ml superoxide dismutase. RESULTS: SNAP or pyrogallol alone had no effect on cardiac function at the concentration used; however, infusion of the combination of SNAP and pyrogallol resulted in significant decreases in left ventricular developed pressure (to 83 +/- 4%, P < 0.01, versus vehicle) and dp/dtmax (to 76 +/- 6.2%, P < 0.01, versus vehicle), and also resulted in a significant increase in production of lactic dehydrogenase (to 118 +/- 4%, P < 0.01, versus vehicle). The administration of superoxide dismutase with SNAP and pyrogallol reversed these deleterious effects. CONCLUSION: These results suggest that the formation of peroxynitrite significantly enhances the toxicities of .NO and O2.- and causes marked cardiac injury.

The complete blood count and reticulocyte count--are they necessary in the evaluation of acute vasoocclusive sickle-cell crisis?

OBJECTIVE: To assess the usefulness of the complete blood count (CBC) and the reticulocyte count in the evaluation of adult patients with acute vasoocclusive sickle-cell crisis (SCC) presenting to the ED. METHODS: A 2-part study was performed. Part 1 was retrospective chart review of patients with a sole ED diagnosis of acute SCC. Part 2 was a prospective evaluation of consecutive patients presenting in SCC. In both parts of the study, patients with coexisting acute disease were excluded. The remaining patients were divided into 2 groups: admitted and released. The mean values for white blood cell (WBC) count, hemoglobin (Hb) level, and reticulocyte count were compared. In Part 2, the change (delta) from the patient's baseline in WBC count, Hb level, and reticulocyte count also was determined. Data were analyzed by 2-tailed Student's t-test. RESULTS: Part 1: There was no difference between the admitted (n = 33) and the released (n = 86) groups in mean WBC count (p = 0.10), Hb level (p = 0.25), or reticulocyte count (p = 0.08). Part 2: There was no difference between the admitted (n = 44) and the released (n = 160) groups in mean Hb level (p = 0.88), reticulocyte count (p = 0.47), delta Hb level (p = 0.88), and delta reticulocyte count (p = 0.76). There was a difference in mean WBC counts (15.8 +/- 4.9 x 10(9)/L admitted vs 12.8 +/- 4.9 x 10(9)/L released, p = 0.003) and delta WBC counts (5.1 +/- 4.6 x 10(9)/L admitted vs 1.8 +/- 4.6 x 10(9)/L released, p < 0.002). CONCLUSION: Determination of the Hb level and the reticulocyte count do not appear useful in the evaluation of acute SCC in the ED. Admission decisions appear associated with elevations in the WBC count. Further study is required to determine the true value of the WBC count in such decisions.

Nitric oxide metabolite levels in acute vaso-occlusive sickle-cell crisis.

OBJECTIVES: 1) To measure nitric oxide (NO) metabolite levels in patients presenting to the ED in acute vaso-occlusive sickle-cell crisis (SCC), and 2) to determine whether a relationship exists between NO metabolite levels and pain. METHODS: A prospective, observational study of patients with documented sickle-cell anemia (SCA), aged > or = 18 years, presenting in typical, acute SCC was conducted in an urban, university teaching hospital. Excluded were those with atypical pain or acute, coexistent disease (as evidenced by fever, tachycardia, tachypnea, or hypotension). Pain scores were measured by a 10-cm visual analog scale (VAS). Blood NO metabolite levels for SCC patients and control subjects (healthy volunteers, n = 9; SCA control subjects not in SCC, n = 10) were determined using an NO-specific chemiluminescence technique that measured plasma nitrite and nitrate, the stable end-products of NO. The acute SCC patients were divided into 3 groups, with the range for the SCC-normal (n = 5) group defined as within 2 SD of the healthy volunteer control patients. The SCC-low patients (n = 21) had NO metabolite levels below this range and the SCC-high (n = 21) patients had levels above this range. RESULTS: The SCA and healthy volunteer control groups had similar NO metabolite levels (25.3 vs 22.6 mumol; p = 0.10). The 3 acute SCC groups had the following mean NO levels: 1) SCC-normal = 21.3 +/- 1.6 mumol; 2) SCC-low = 7.2 +/- 1.1 mumol; and 3) SCC-high = 43.7 +/- 3.5 mumol. The SCC-high NO-level group had significantly lower VAS pain scores when compared with the SCC-low and SCC-normal NO-level groups (6.52 +/- 1.85 cm vs 8.76 +/- 0.83 cm, and 8.62 +/- 1.29 cm, p = 0.02). CONCLUSION: NO metabolite levels vary in SCC patients. Elevated levels are associated with lower pain scores, while lower levels are associated with higher pain scores, indicating that NO metabolites may potentially represent a marker for compensatory mechanisms in SCC tissue ischemia. Further work is needed to delineate the usefulness of NO metabolites in assessing the severity of SCC.

Clinically meaningful changes in quantitative measures of asthma severity.

OBJECTIVE: To determine minimum clinically meaningful improvements in peak expiratory flow rate (PEFR) and dyspnea visual analog score (VAS) in patients with acute asthma exacerbation. METHODS: Patients presenting to the emergency department (ED) with acute asthma exacerbation were eligible. The PEFR and VAS were assessed at presentation and after initial asthma therapy. During reassessment, subjects were asked to describe their asthma symptoms as "much better," "a little better," "no change," "a little worse," or "much worse." Correspondence between self-reported improvement and changes in PEFR and VAS was assessed. The "minimum clinically significant change" in either index was defined as the difference between pre- and posttreatment measures in subjects reporting their symptoms "a little better." RESULTS: One hundred fifty-six subjects were included. Asthma symptoms were "much better" in 99 (64%), "a little better" in 41 (26%), and "unimproved" (composed of patients describing symptoms as "no change," "a little worse," or "much worse") in 16 (10%). The mean VAS change among the "a little better" subjects was 2.2 cm (95% CI = 1.1 to 3.4), significantly greater than the -0.4 cm (95% CI = -2.1 to 1.4) change in the "unimproved" subjects. The mean change in percent predicted PEFR among the "a little better" subjects was 11.9 (95% CI = 7.3 to 16.1), not statistically different from the change of 6.1 (95% CI = 1.1 to 11.3) in the "no change" subjects. The "much better" group showed significantly greater changes in both measures than either of the other groups. A VAS change of > or =0.5 cm reliably discriminated between subjects with and without symptom improvement. CONCLUSIONS: Improvements in VAS of 2.2 cm and in predicted PEFR of about 12 percentage points are minimal clinically significant improvements during ED asthma therapy. The dyspnea VAS is valid in assessing symptomatic changes and may detect small subjective improvements better than the PEFR.

Role of ERK1/2 in the anti-apoptotic and cardioprotective effects of nitric oxide after myocardial ischemia and reperfusion.

OBJECTIVE: Experimental results from cultured cells suggest that there is cross-talk between nitric oxide (NO) and extracellular signal-regulated kinase (ERK) in their anti-apoptotic effect. However, the cross-talk between these two molecules in either direction has not been confirmed in the whole organ or whole animal level. The aim of the present study was to determine whether ERK may play a role in the anti-apoptotic and cardioprotective effects of NO in myocardial ischemia/reperfusion (MI/R). METHODS: Isolated perfused mouse hearts were subjected to 20 min of global ischemia and 120 min of reperfusion and treated with vehicle or an NO donor (SNAP, 10 muM) during reperfusion. To determine the role of ERK1/2 in the anti-apoptotic and cardioprotective effects of NO, hearts were pre-treated (10 min before ischemia) with U0126, a selective MEK1/2 inhibitor (1 muM). RESULTS: Treatment with SNAP exerted significant cardioprotective effects as evidenced by reduced cardiac apoptosis (TUNEL and caspase 3 activity, p < 0.01), and improved cardiac functional recovery (p < 0.01). In addition, treatment with SNAP resulted in a 2.5-fold increase in ERK activation when compared with heart receiving vehicle. Pre-treatment with U0126 slightly increased post-ischemic myocardial apoptosis but had no significant effect on cardiac functional recovery in this isolated perfused heart model. However, treatment with U0126 completely blocked SNAP-induced ERK activation and markedly, although not completely, inhibited the cardioprotection exerted by SNAP. CONCLUSION: These results demonstrate that nitric oxide exerts its anti-apoptotic and cardioprotective effects, at least in part, by activation of ERK in ischemic/reperfused heart.

Nitrate tolerance aggravates postischemic myocardial apoptosis and impairs cardiac functional recovery after ischemia.

OBJECTIVES: This study examined the effects of nitrate tolerance (NT) on myocardial ischemia reperfusion (MI/R) injury and elucidated the potential mechanisms involved. Furthermore, the effects of GSH on postischemic myocardial apoptosis in NT rats were investigated. METHODS AND RESULTS: Male Sprague-Dawley rats were randomized to receive nitroglycerin (60 microg/kg/h) or saline for 12 h followed by 40 min of MI and 4 h of reperfusion. Myocardial apoptosis, infarct size, nitrotyrosine formation, plasma CK and LDH activity, and cardiac function were determined. MI/R resulted in significant apoptotic cell death, which was further increased in animals with NT. In addition, NT further increased plasma CK and LDH activity, enlarged infarct size, and impaired cardiac functional recovery after ischemia. Myocardial nitrotyrosine, a footprint for cytotoxic reactive nitrogen species formation, was further enhanced in the NT heart after MI/R. Treatment of NT animals with exogenous GSH inhibited nitrotyrosine formation, reduced apoptosis, decreased infarct size, and improved cardiac functional recovery. CONCLUSION: Our results demonstrate that nitrate tolerance markedly enhances MI/R injury and that increased peroxynitrite formation likely plays a role in this pathologic process. In addition, our results suggest that GSH could decrease peroxynitrite formation and reduce MI/R injury in nitrate tolerant hearts.