Should high-dose interleukin-2 still be the preferred treatment for patients with metastatic melanoma?

For more than 20 years interleukin-2 (IL2) was the preferred treatment for medically fit metastatic melanoma patients, but recently two new agents, ipilimumab and vemurafenib, were approved for stage IV disease. Single-institution data were used to determine the long-term survival rate for IL2-treated melanoma patients, and whether use of inpatient IL2 had declined recently. Between May 1987 and April 2010, 150 patients were hospitalized for high-dose, intravenous (i.v.) IL2. The average number of IL2 patients increased from 5.4 per year during 1987-1991 to 5.8 during 1992-1997 after regulatory approval of IL2, to 8.3 during 1998-2006 after a marketing indication in metastatic melanoma was granted, but dropped to 3.0 during 2007-2010. At the time of treatment, median age was 52 years; 27% were 60 years of age or older. At the time of analysis 122 patients were deceased. Median survival from the start date of IL2 treatment was 15.6 months, with a 20% 5-year survival. Among patients enrolled in clinical trials, there were as many nonresponders who survived 5 years as responders, which is consistent with a delayed immunotherapy benefit. In the absence of long-term survival data for these newer agents, IL2 probably should still be the preferred initial treatment for most patients with metastatic melanoma who are medically fit.     

A ketogenic diet rescues the murine succinic semialdehyde dehydrogenase deficient phenotype

Succinic semialdehyde dehydrogenase (SSADH) deficiency is a heritable disorder of GABA degradation characterized by ataxia, psychomotor retardation and seizures. To date, there is no effective treatment for SSADH deficiency. We tested the hypothesis that a ketogenic diet (KD) would improve outcome in an animal model of SSADH deficiency, the SSADH knockout mouse (Aldh5a1-/-). Using a 4:1 ratio of fat to combined carbohydrate and protein KD we set out to compare the general phenotype, in vivo and in vitro electrophysiology and [35S]TBPS binding in both Aldh5a1-/- mice and control (Aldh5a1+/+) mice. We found that the KD prolonged the lifespan of mutant mice by >300% with normalization of ataxia, weight gain and EEG compared to mutants fed a control diet. Aldh5a1-/- mice showed significantly reduced mIPSC frequency in CA1 hippocampal neurons as well as significantly decreased [35S]TBPS binding in all brain areas examined. In KD fed mutants, mIPSC activity normalized and [35S]TBPS binding was restored in the cortex and hippocampus. The KD appears to reverse toward normal the perturbations seen in Aldh5a1-/- mice. Our data suggest that the KD may work in this model by restoring GABAergic inhibition. These data demonstrate a successful experimental treatment for murine SSADH deficiency using a KD, giving promise to the idea that the KD may be successful in the clinical treatment of SSADH deficiency.     

Intraoperative bile duct visualization using near-infrared hyperspectral video imaging

BACKGROUND: Current methodologies for imaging the biliary system during cholecystectomy are cumbersome and do not eliminate the risk of bile duct injury. We describe an approach to intraoperative biliary imaging that will enable surgeons to see through the hepatoduodenal ligament and visualize the anteriorly placed biliary system. METHODS: A laparoscopic-capable, near-infrared, hyperspectral imaging system was built. Reflected light passes through a liquid crystal filter that is continuously tunable in the near-infrared spectrum (650-1,100 nm). Spectroscopic image data are collected from laparoscopic surgery images onto array detectors formatted into a 3-dimensional hyperspectral data cube having spatially resolved images in the x-y plane and wavelength data in the z plane. Deconvoluting and color-coding the spatial and spectral information provides an image representative of inherent chemical properties to the imaged tissue. RESULTS: Images of porcine biliary structures were obtained. The common duct-reflected spectra displayed a characteristic lipid shoulder at 930 nm and a strong water peak at 970 nm. Venous structures had absorption peaks at 760 nm (deoxyhemoglobin), 800 nm (oxyhemoglobin), and 970 nm (water). Arterial vessels had absorption peaks at 800 nm and 970 nm that would be expected for oxyhemoglobin and water. CONCLUSIONS: We have designed and constructed a device to significantly enhance intraoperative biliary imaging. This system should enable surgeons to see through the hepatoduodenal ligament and image the anteriorly placed biliary system without the need for dissection of the cystic duct, as is needed with intraoperative cholangiography. Because the biliary system can be seen before any dissection is performed, this dimensional imaging technology has the potential for eradicating bile duct injury.     

Hepatic lipase mRNA, protein, and plasma enzyme activity is increased in the insulin-resistant, fructose-fed Syrian golden hamster and is partially normalized by the insulin sensitizer rosiglitazone

Postheparin plasma hepatic lipase (HL) activity has been shown to correlate with features of the metabolic syndrome and type 2 diabetes in humans. We examined HL postheparin plasma enzyme activity, hepatocyte mRNA, and protein mass in the insulin-resistant, fructose-fed Syrian golden hamster, and the response of the insulin-sensitizing peroxisome proliferator-activated receptor-gamma agonist rosiglitazone. Male Syrian golden hamsters were treated for 5 weeks with 1) normal diet (DIET group), 2) 60% fructose diet (FRUC group), or 3) 60% fructose and rosiglitazone (20 mmol . kg(-1) . day(-1)) (FRUC+RSG group). Hepatocyte HL mRNA, protein mass, and postheparin plasma HL activity were increased in FRUC compared with DIET hamsters. FRUC+RSG hamsters had partial normalization of HL mRNA, mass, and activity. There was a shift in the size of LDL particles from large to small in FRUC animals and a shift back to large LDL size in FRUC+RSG. This is the first demonstration that HL hepatocyte mRNA, mass, and plasma enzymatic activity increase concomitantly with induction of an insulin-resistant state and can be partially normalized by treatment with an insulin sensitizer. The increase in HL in insulin-resistant states may play an important role in the typical dyslipidemia of these conditions, and reduction of HL could explain some of the beneficial effects of insulin sensitizers on the plasma lipid profile.     

Lipolytically modified triglyceride-enriched HDLs are rapidly cleared from the circulation

The precise biochemical mechanisms underlying the reduction of HDL levels in hypertriglyceridemic states are currently not known. In humans, we showed that triglyceride (TG) enrichment of HDL, as occurs in hypertriglyceridemic states, enhances the clearance of HDL-associated apolipoprotein A-I (apoA-I) from the circulation. In the New Zealand White rabbit (an animal model naturally deficient in hepatic lipase [HL]), however, TG enrichment of HDL is not sufficient to alter the clearance of either the protein or lipid moieties of HDL. In the present study, therefore, we determined in the New Zealand White rabbit the combined effects of ex vivo TG enrichment and lipolytic transformation of HDL by HL on the subsequent metabolic clearance of HDL apoA-I. Results of the in vivo kinetic studies (n=18 animals) showed that apoA-I associated with TG-enriched rabbit HDL modified ex vivo by catalytically active HL was cleared 22% more rapidly versus TG-enriched HDL incubated with heat-inactivated HL, and 26% more rapidly than fasting (TG-poor) HDL incubated with active HL (P<0.05 for both). Furthermore, a strong correlation was observed between the HDL TG content and apoA-I fractional catabolic rate (0.59, P<0.05) in the combined active HL groups. These data establish that TG enrichment of HDL with subsequent lipolysis by HL enhances HDL apoA-I clearance, but neither TG enrichment of HDL without HL lipolysis nor HL lipolysis in the absence of previous TG enrichment of HDL is sufficient to enhance HDL clearance. These data further support the important interaction between HDL TG enrichment and HL action in the pathogenesis of HDL lowering in hypertriglyceridemic states.     

Simvastatin,an HMG-CoA reductase inhibitor,induces the synthesis and secretion of apolipoprotein AI in HepG2 cells and primary hamster hepatocytes

Clinical studies have recently suggested that statin treatment may beneficially elevate plasma concentrations of high density lipoprotein (HDL)-cholesterol in patients with hyperlipidemia. Here, we have investigated the effect of a potent inhibitor of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase on the synthesis and secretion of apolipoprotein AI (apoAI) in two model systems, HepG2 cells and primary hamster hepatocytes. Cultured cells were incubated with different doses of simvastatin (0.1-10 microM) for a period of 18 h. A dose-dependent increase in synthesis and secretion of apoAI was observed in both cell types. There was a significant increase in the synthesis of apoAI in HepG2 cells (44.3+/-12.1%), and hamster hepatocytes (212+/-2%) after treatment with 10 microM of the statin. The increase in apoAI synthesis appeared to result in a higher level of apoAI secreted into the culture media in both cell types (49.2+/-7.8% in HepG2, 197+/-0.2% in hamster hepatocytes). ApoAI mRNA levels were also significantly increased in both cell types in response to statin treatment. Control experiments with transferrin confirmed specificity of the effect on apoAI secretion. Analysis of a density fraction containing HDL particles in culture media revealed an increase in HDL-associated apoAI of 94.3+/-2.1% in HepG2 cells and 27.0+/-0.03% in hamster hepatocytes following 10 microM simvastatin-treatment. Comparative studies of simvastatin and lovastatin indicated a differential ability to induce apoAI synthesis and secretion, with simvastatin having a more significant effect. Thus, acute statin treatment of cultured hepatocytes (transformed as well as primary) resulted in a significant upregulation of apoAI mRNA and apoAI synthesis, causing oversecretion of apoAI and HDL extracellularly. The stimulatory effect on apoAI synthesis and secretion may thus explain the clinical observation of an elevated plasma HDL-cholesterol level in hyperlipidemic patients treated with certain statins.     

Accessibility of blood glucose monitoring systems for blind and visually impaired people

Blindness and visual impairment are prevalent among people with diabetes. Blood glucose monitoring systems (BGMSs) have revolutionized diabetes care, but none of the 30 or so commercially available monitoring systems was designed to be fully accessible to blind and visually impaired persons. Seventeen BGMSs were evaluated for accessible use by people who are blind or visually impaired. Features and functionalities (e.g., operating procedures, user interface design, device specifications, and computer interface capabilities) were examined and tabulated, as was usability and accessibility. A subset of these systems with the highest degree of accessibility was selected and thoroughly examined and tested. Additionally, 12 people who are blind or visually impaired and who were issued BGMSs by their physician or diabetes educator were interviewed and videotaped using their meters. Of the 17 BGMSs, only four had voice output capability, an essential component of accessibility for blind and visually impaired persons. The six BGMSs without voice output that had the largest display fonts were found to have few accessibility features for visually impaired persons. Users indicated that voice output and portability were desired attributes of an accessible BGMS. None of the BGMSs evaluated had all of the required accessibility attributes, including the four systems that had voice output capability. The four systems with voice output were much bulkier and heavier than those that did not have this capability. Recommendations are made for design and development of BGMSs that would increase effective usage by blind and visually impaired persons, including integrating text to speech and streamlining the blood glucose monitoring process.     

Minocycline-induced cutaneous pigmentation

A 76-year-old man receiving long-term prednisone therapy for rheumatoid arthritis had a four-part intertrochanteric fracture after a fall. The patient underwent an open reduction with internal fixation and dynamic hip screw placement. Two months later, when the patient presented with significant pain and difficulty ambulating, radiographs revealed dissociation of the compression screw from the femoral head. At the time of removal of failed hardware, a total hip replacement procedure was aborted when intraoperative findings were consistent with infection. Thorough irrigation and debridement were performed, with placement of antibiotic-impregnated cement spacers. One month after a 4-week course of intravenous cefazolin, the patient underwent left total hip arthroplasty. Intraoperative cultures grew methicillin-resistant Staphylococcus aureus and Corynebacterium jeikeium. A 4-week course of intravenous vancomycin was followed by long-term antibiotic suppression with long-term minocycline (100 mg twice daily). Six months after starting minocycline, the patient noticed a blue-gray discoloration of the forearms. During the next 4 months, the pigmentation progressed considerably. He was admitted to Mayo Clinic for a myocardial infarction. Three-vessel coronary artery disease was discovered, necessitating bypass grafting. Before surgery, dermatology was consulted. A main concern of the primary service was the discoloration representing ecchymoses in a surgical candidate with a possible bleeding diathesis. Cutaneous examination revealed slate gray, ill-defined patches in the preauricular, flank, upper thigh, and shoulder areas. Similar patches coalesced on the upper and lower extremities ( Fig. 1 ). There was no scleral or mucous membrane involvement. Histologically, minocycline pigmentation with pigment-laden macrophages and free dermal pigment in the papillary and superficial reticular dermis stained positive with Prussian blue and Fontana-Masson ( Fig. 2 ). Minocycline was discontinued, and the patient was started on trimethoprim-sulfamethoxazole double strength once daily for long-term antimicrobial therapy.

Figure 1 Open in figure viewer PowerPoint Minocycline-induced slate gray discoloration of the (a) arms and (b) shins     

Growth inhibition of human colon cancer cells by nitric oxide (NO)-donating aspirin is associated with cyclooxygenase-2 induction and beta-catenin/T-cell factor signaling, nuclear factor-kappaB, and NO synthase 2 inhibition: implications for chemoprevention

Nitric oxide (NO)-releasing aspirin (ASA), consisting of a traditional ASA molecule to which a NO-donating moiety is covalently bound, is a promising colon cancer chemopreventive agent. NO-ASA inhibits colon cancer cell growth more potently than ASA by inhibiting cell proliferation and enhancing cell killing. We examined in cultured human colon cancer cells the effect of NO-ASA on the beta-catenin/T-cell factor signaling pathway, nuclear factor-kappaB, and NO synthase 2 and on cyclooxygenase (COX) expression, all presumed to participate in colon carcinogenesis. Besides inhibiting cell growth, NO-ASA inhibited the beta-catenin/T-cell factor signaling pathway (IC(50), 1.1 microM), nuclear factor-kappaB DNA binding (IC(50), 7.5 microM), and NO synthase 2 expression (IC(50), 2 microM). Interestingly, NO-ASA induced COX-2 expression, although it had no effect on COX-1. COX-2 induction was accompanied by increased prostaglandin E(2) production. These effects occurred at NO-ASA concentrations below or near its IC(50) for cell growth (IC(50), 2-50 microM). The metabolism of NO-ASA by these cells is characterized by a rapid deacetylation step and the formation of a conjugate with glutathione. NO-ASA had no effect on intracellular cyclic GMP concentrations. We propose a model incorporating the pleiotropic effects of NO-ASA on cell signaling and postulate that collectively these effects may contribute to its strong chemopreventive effect.     

Disordered fat storage and mobilization in the pathogenesis of insulin resistance and type 2 diabetes

The primary genetic, environmental, and metabolic factors responsible for causing insulin resistance and pancreatic beta-cell failure and the precise sequence of events leading to the development of type 2 diabetes are not yet fully understood. Abnormalities of triglyceride storage and lipolysis in insulin-sensitive tissues are an early manifestation of conditions characterized by insulin resistance and are detectable before the development of postprandial or fasting hyperglycemia. Increased free fatty acid (FFA) flux from adipose tissue to nonadipose tissue, resulting from abnormalities of fat metabolism, participates in and amplifies many of the fundamental metabolic derangements that are characteristic of the insulin resistance syndrome and type 2 diabetes. It is also likely to play an important role in the progression from normal glucose tolerance to fasting hyperglycemia and conversion to frank type 2 diabetes in insulin resistant individuals. Adverse metabolic consequences of increased FFA flux, to be discussed in this review, are extremely wide ranging and include, but are not limited to: 1) dyslipidemia and hepatic steatosis, 2) impaired glucose metabolism and insulin sensitivity in muscle and liver, 3) diminished insulin clearance, aggravating peripheral tissue hyperinsulinemia, and 4) impaired pancreatic beta-cell function. The precise biochemical mechanisms whereby fatty acids and cytosolic triglycerides exert their effects remain poorly understood. Recent studies, however, suggest that the sequence of events may be the following: in states of positive net energy balance, triglyceride accumulation in "fat-buffering" adipose tissue is limited by the development of adipose tissue insulin resistance. This results in diversion of energy substrates to nonadipose tissue, which in turn leads to a complex array of metabolic abnormalities characteristic of insulin-resistant states and type 2 diabetes. Recent evidence suggests that some of the biochemical mechanisms whereby glucose and fat exert adverse effects in insulin-sensitive and insulin-producing tissues are shared, thus implicating a diabetogenic role for energy excess as a whole. Although there is now evidence that weight loss through reduction of caloric intake and increase in physical activity can prevent the development of diabetes, it remains an open question as to whether specific modulation of fat metabolism will result in improvement in some or all of the above metabolic derangements or will prevent progression from insulin resistance syndrome to type 2 diabetes.