Erosion during extreme flood events dominates Holocene canyon evolution in northeast Iceland.

Extreme flood events have the potential to cause catastrophic landscape change in short periods of time (10(0) to 10(3) h). However, their impacts are rarely considered in studies of long-term landscape evolution (>10(3) y), because the mechanisms of erosion during such floods are poorly constrained. Here we use topographic analysis and cosmogenic (3)He surface exposure dating of fluvially sculpted surfaces to determine the impact of extreme flood events within the Jökulsárgljúfur canyon (northeast Iceland) and to constrain the mechanisms of bedrock erosion during these events. Surface exposure ages allow identification of three periods of intense canyon cutting about 9 ka ago, 5 ka ago, and 2 ka ago during which multiple large knickpoints retreated large distances (>2 km). During these events, a threshold flow depth was exceeded, leading to the toppling and transportation of basalt lava columns. Despite continuing and comparatively large-scale (500 m(3)/s) discharge of sediment-rich glacial meltwater, there is no evidence for a transition to an abrasion-dominated erosion regime since the last erosive event because the vertical knickpoints have not diffused over time. We provide a model for the evolution of the Jökulsárgljúfur canyon through the reconstruction of the river profile and canyon morphology at different stages over the last 9 ka and highlight the dominant role played by extreme flood events in the shaping of this landscape during the Holocene.

Chitin, chitosan, and glycated chitosan regulate immune responses: the novel adjuvants for cancer vaccine.

With the development of cancer immunotherapy, cancer vaccine has become a novel modality for cancer treatment, and the important role of adjuvant has been realized recently. Chitin, chitosan, and their derivatives have shown their advantages as adjuvants for cancer vaccine. In this paper, the adjuvant properties of chitin and chitosan were discussed, and some detailed information about glycated chitosan and chitosan nanoparticles was also presented to illustrate the trend for future development.

Cancer photo-immunotherapy: from bench to bedside.

Targeted therapy and immunotherapy in combination is considered the ideal strategy for treating metastatic cancer, as it can eliminate the primary tumors and induce host immunity to control distant metastases. Phototherapy, a promising targeted therapy, eradicates primary tumors using an appropriate dosage of focal light irradiation, while initiating antitumor immune responses through induced immunogenic tumor cell death. Recently, phototherapy has been employed to improve the efficacy of immunotherapies such as chimeric antigen receptor T-cell therapy and immune checkpoint inhibitors. Phototherapy and immunoadjuvant therapy have been used in combination clinically, wherein the induced immunogenic cell death and enhanced antigen presentation synergy, inducing a systemic antitumor immune response to control residual tumor cells at the treatment site and distant metastases. This review summarizes studies on photo-immunotherapy, the combination of phototherapy and immunotherapy, especially focusing on the development and progress of this unique combination from a benchtop project to a promising clinical therapy for metastatic cancer.

Fluidal pyroclasts reveal the intensity of peralkaline rhyolite pumice cone eruptions.

Peralkaline rhyolites are medium to low viscosity, volatile-rich magmas typically associated with rift zones and extensional settings. The dynamics of peralkaline rhyolite eruptions remain elusive with no direct observations recorded, significantly hindering the assessment of hazard and risk. Here we describe uniquely-preserved, fluidal-shaped pyroclasts found within pumice cone deposits at Aluto, a peralkaline rhyolite caldera in the Main Ethiopian Rift. We use a combination of field-observations, geochemistry, X-ray computed microtomography (XCT) and thermal-modelling to investigate how these pyroclasts are formed. We find that they deform during flight and, depending on size, quench prior to deposition or continue to inflate then quench in-situ. These findings reveal important characteristics of the eruptions that gave rise to them: that despite the relatively low viscosity of these magmas, and similarities to basaltic scoria-cone deposits, moderate to intense, unstable, eruption columns are developed; meaning that such eruptions can generate extensive tephra-fall and pyroclastic density currents.

Imiquimod as an antiaging agent.

BACKGROUND: Topical imiquimod therapy has proven to be effective for a variety of infectious, neoplastic, and inflammatory dermatologic diseases. Several published reports have validated the benefit of imiquimod therapy for actinic keratoses and superficial melanoma and nonmelanoma skin cancers. There is, however, limited evidence demonstrating the use of topical imiquimod application as an antiaging treatment. OBJECTIVES: We examined the effectiveness of imiquimod 5% cream in the treatment of photoaging by evaluating pretreatment and posttreatment biopsy specimens and documenting the histologic changes. METHODS: This study represents an extension of an earlier project in our department in which patients with biopsy-proven lesions of lentigo maligna (LM) were recruited from a university dermatology service, a hospital, and referrals from private practitioners for an open-labeled efficacy trial with daily topical application of 5% imiquimod for 3 months. Biopsy of clinically affected skin was carried out on all patients before and after treatment. Using a semiquantitative method, biopsy specimens were analyzed for changes in the dermal collagen table (solar elastosis vs papillary dermal fibroplasia). Additional parameters analyzed included epidermal changes (atrophy vs acanthosis, melanin content, and hypergranulosis) and inflammatory effects (epidermal and dermal cell populations along with presence of pigment incontinence). Variables were compared using paired Wilcoxan rank sums. RESULTS: Of 26 evaluable patients who completed 3 months of daily application, 24 (>92.3%) showed a significant increase in papillary dermal fibroplasia (P < .0001) with associated reduction in solar elastosis (P = .0036). Other noteworthy findings were restoration of normal epidermal thickness (P = .0073) and melanization (P < .0001). LIMITATIONS: This study only evaluates the effect of imiquimod in the lesional skin of LM. It is not known whether the results are applicable to nonlesional, photoaged skin. CONCLUSION: Topical imiquimod appears to induce reparative changes to the epidermis and the dermal collagen table in chronically sun-damaged skin associated with LM, indicating its potential use as an antiaging treatment. These findings need to be confirmed in photodamaged skin not associated with LM.

Treatment of advanced melanoma with laser immunotherapy and ipilimumab.

Immunotherapy has become a promising modality for melanoma, especially using checkpoint inhibitors, which revive suppressed T cells against the cancer. Such inhibitors should work better when combined with other treatments which could increase the number and quality of anti-tumor T cells. We treated one patient with advanced (stage IV) melanoma, using the combination of laser immunotherapy (LIT), a novel immunological approach for metastatic cancers that has been shown to stimulate adaptive immunity, and ipilimumab. The patient was treated with LIT, followed with one course of ipilimumab 3 months after the beginning of LIT. After LIT treatment, all treated cutaneous melanoma in head and neck cleared completely. After the application of ipilimumab, all the tumor nodules in the lungs decreased. The patient had remained tumor free for one year. While anecdotal, the responses seen in this patient support the hypothesis that laser immunotherapy increases the number and quality of anti-tumor T cells so that ipilimumab and other checkpoint inhibitors are more effective in enhancing the therapeutic effects. Picture: Schematic of treatment using laser immunotherapy and ipilimumab on a stage IV melanoma patient.

Non-melanoma skin cancer in patients with atopic dermatitis treated with topical tacrolimus.

OBJECTIVE: To determine whether atopic dermatitis (AD) patients treated with tacrolimus ointment experienced an increased risk of non-melanoma skin cancer (NMSC). METHODS: Data were collected from 9813 adult and paediatric patients with AD who applied 0.03% or 0.1% tacrolimus ointment twice daily and were examined every 3 months during the tacrolimus ointment development programme. RESULTS: Thirteen adult patients were diagnosed with NMSC during the follow-up period. All patients with NMSC were white adults and 12 were over 40 years of age. Based on 1718 patient-years of tacrolimus ointment exposure in patients 40 years of age, the calculated incidence of NMSC did not suggest an increased risk of first NMSC over that of a similarly aged US cohort. CONCLUSION: This study does not indicate an increased risk for the development of NMSC in patients with AD treated with tacrolimus ointment for a mean duration of 208 days with a maximum observation period of 1479 days.

Imiquimod and superficial skin cancers.

Topical imiquimod has opened an entirely new area of dermatology that previously did not exist: medical therapy for skin cancers. While surgery will continue to play a vital role in treating more aggressive tumors and in patients who may not be imiquimod candidates, the availability of a viable medical therapy that can be used independently or in combination with other modalities will considerably enhance our ability to treat skin cancer successfully.

InCVAX--a novel strategy for treatment of late-stage, metastatic cancers through photoimmunotherapy induced tumor-specific immunity.

A novel, promising potential cancer vaccine strategy was proposed to use a two-injection procedure for solid tumors to prompt the immune system to identify and systemically eliminate primary and metastatic cancers. The two-injection procedure consists of local photothermal application on a selected tumor intended to liberate whole cell tumor antigens, followed by a local injection of an immunoadjuvant that consists of a semi-synthetic functionalized glucosamine polymer, N-dihydro-galacto-chitosan (GC), which is intended to activate antigen presenting cells and facilitate an increased uptake of tumor antigens. This strategy is thus proposed as an in situ autologous cancer vaccine (inCVAX) that may activate antigen presenting cells and expose them to tumor antigens in situ, with the intention of inducing a systemic tumor specific T-cell response. Here, the development of inCVAX for the treatment of metastatic cancers in the past decades is systematically reviewed. The antitumor immune responses of local photothermal treatment and immunological stimulation with GC are also discussed. This treatment approach is also commonly referred to as laser immunotherapy (LIT).

Topical chemotherapy in cutaneous T-cell lymphoma: positive results of a randomized, controlled, multicenter trial testing the efficacy and safety of a novel mechlorethamine, 0.02%, gel in mycosis fungoides.

OBJECTIVE: To evaluate the efficacy and safety of a novel mechlorethamine hydrochloride, 0.02%, gel in mycosis fungoides. DESIGN Randomized, controlled, observer-blinded, multicenter trial comparing mechlorethamine, 0.02%, gel with mechlorethamine, 0.02%, compounded ointment. Mechlorethamine was applied once daily for up to 12 months. Tumor response and adverse events were assessed every month between months 1 and 6 and every 2 months between months 7 and 12. Serum drug levels were evaluated in a subset of patients. SETTING: Academic medical or cancer centers. PATIENTS: In total, 260 patients with stage IA to IIA mycosis fungoides who had not used topical mechlorethamine within 2 years and were naive to prior use of topical carmustine therapy. MAIN OUTCOME MEASURES: Response rates of all the patients based on a primary clinical end point (Composite Assessment of Index Lesion Severity) and secondary clinical end points (Modified Severity-Weighted Assessment Tool and time-to-response analyses). RESULTS: Response rates for mechlorethamine gel vs ointment were 58.5% vs 47.7% by the Composite Assessment of Index Lesion Severity and 46.9% vs 46.2% by the Modified Severity-Weighted Assessment Tool. By the Composite Assessment of Index Lesion Severity, the ratio of gel response rate to ointment response rate was 1.23 (95% CI, 0.97-1.55), which met the prespecified criterion for noninferiority. Time-to-response analyses demonstrated superiority of mechlorethamine gel to ointment (P< .01). No drug-related serious adverse events were seen. Approximately 20.3% of enrolled patients in the gel treatment arm and 17.3% of enrolled patients in the ointment treatment arm withdrew because of drug-related skin irritation. No systemic absorption of the study medication was detected. CONCLUSION: The use of a novel mechlorethamine, 0.02%, gel in the treatment of patients with mycosis fungoides is effective and safe. TRIAL REGISTRATION: clinicaltrials.gov Identifier:NCT00168064.

Tretinoin and the prevention of keratinocyte carcinoma (Basal and squamous cell carcinoma of the skin): a veterans affairs randomized chemoprevention trial.

Keratinocyte carcinoma (KC) is the most common cancer in the United States, with no proven means for prevention other than systemic retinoids, which have significant toxicity, and sunscreen. Topical tretinoin has been used for KC chemoprevention, although this use is unproven. Hence, we conducted the randomized Veterans Affairs Topical Tretinoin Chemoprevention Trial of high-dose topical tretinoin for KC prevention. We randomized 1,131 patients to topical 0.1% tretinoin or a matching vehicle control for 1.5-5.5 years. The primary outcomes were time to development of new basal cell carcinoma (BCC) and new invasive squamous cell carcinoma (SCC) on the face or ears. The effects were not significant (P=0.3 for BCC and P=0.4 for SCC). The proportions of the tretinoin and control groups who developed a BCC at 5 years were 53 and 54% and an invasive SCC at 5 years were 28 and 31%. These differences (95% confidence intervals) were: for BCC, 1.0% (-6.5, 8.6%); for SCC, 3.6% (-3.1, 10.3%). No differences were observed in any cancer-related end points or in actinic keratosis counts. The only quality of life difference was worse symptoms in the tretinoin group at 12 months after randomization. This trial in high-risk patients demonstrates that high-dose topical tretinoin is ineffective at reducing risk of KCs.

Entropy production and self-organized (sub)criticality in earthquake dynamics.

We derive an analytical expression for entropy production in earthquake populations based on Dewar's formulation, including flux (tectonic forcing) and source (earthquake population) terms, and apply it to the Olami-Feder-Christensen numerical model for earthquake dynamics. Assuming the commonly observed power-law rheology between driving stress and remote strain rate, we test the hypothesis that maximum entropy production (MEP) is a thermodynamic driver for self-organized 'criticality' (SOC) in the model. MEP occurs when the global elastic strain is near-critical, with small relative fluctuations in macroscopic strain energy expressed by a low seismic efficiency, and broad-bandwidth power-law scaling of frequency and rupture area. These phenomena, all as observed in natural earthquake populations, are hallmarks of the broad conceptual definition of SOC (which has, to date, often included self-organizing systems in a near but strictly subcritical state). In the MEP state, the strain field retains some memory of past events, expressed as coherent 'domains', implying a degree of predictability, albeit strongly limited in practice by the proximity to criticality and our inability to map the natural stress field at an equivalent resolution to the numerical model.

Clinical effects of in situ photoimmunotherapy on late-stage melanoma patients: a preliminary study.

Metastatic melanoma is a skin cancer with poor prognosis. In situ photoimmunotherapy (ISPI) is a promising modality for the treatment of metastatic melanoma that combines local, selective photothermal therapy with immunological stimulation. A preliminary clinical study was conducted to evaluate the safety and therapeutic effects of ISPI for late-stage melanoma patients using imiquimod as the immune modifier. Eleven patients received ISPI in one or multiple 6-week treatment cycles applied to a 200-cm2 treatment site, which usually contained multiple cutaneous metastases. ISPI consisted of three main components applied directly to the cutaneous metastases: 1) local application of topical imiquimod; 2) injection of indocyanine green (ICG); and 3) an 805 nm laser for local irradiation. All patients completed at least one cycle of treatment. The most common adverse effects were rash and pruritus at the treatment sites. No grade 4 toxicity was observed. Complete response was observed in six patients. All lesions in the treatment area of the patients responded to ISPI, eight of which achieved complete local response (CLR). CLR was observed in the non-treatment site (regional) lesions in four patients. Five patients were still alive at the time of last follow-up. The probability of 12-month overall survival was 70%. This study demonstrates that ISPI with imiquimod is safe and well tolerated. The patient response rate is promising. ISPI can be easily applied on an outpatient basis and can be combined with other modalities to improve the therapeutic response of metastatic melanoma.

Origin and nonuniversality of the earthquake interevent time distribution.

Many authors have modeled regional earthquake interevent times using a gamma distribution, whereby data collapse occurs under a simple rescaling of the data from different regions or time periods. We show, using earthquake data and simulations, that the distribution is fundamentally a bimodal mixture distribution dominated by correlated aftershocks at short waiting times and independent events at longer times. The much-discussed power-law segment often arises as a crossover between these two. We explain the variation of the distribution with region size and show that it is not universal.

Actinic keratoses: Natural history and risk of malignant transformation in the Veterans Affairs Topical Tretinoin Chemoprevention Trial.

BACKGROUND: Actinic keratoses (AKs) are established as direct precursors of squamous cell carcinoma (SCC), but there is significant controversy regarding the rate at which AKs progress to SCC. The authors of this report studied a high-risk population to estimate the risk of progression of AK to SCC and to basal cell carcinoma (BCC) and the risk of spontaneous regression of untreated AKs. METHODS: Data were obtained from participants in the Department of Veterans Affairs Topical Tretinoin Chemoprevention Trial. Participants were examined every 6 months for up to 6 years. At each examination, the locations on the face and ears of clinically diagnosed AKs and lesions scheduled for biopsy were marked, and high-resolution digital photographs were taken. These photographs were used later to map and track the presence, absence, or biopsy of each AK across visits. RESULTS: In total, 7784 AKs were identified on the face and ears of 169 participants. The risk of progression of AK to primary SCC (invasive or in situ) was 0.60% at 1 year and 2.57% at 4 years. Approximately 65% of all primary SCCs and 36% of all primary BCCs diagnosed in the study cohort arose in lesions that previously were diagnosed clinically as AKs. The majority of AKs (55%) that were followed clinically were not present at the 1-year follow-up, and the majority (70%) were not present at the 5-year follow-up. CONCLUSIONS: In the current study, the authors quantified the malignant potential of clinically diagnosed AKs for both SCC and BCC, although many did not persist, and the results suggested that AKs may play a greater role in the overall burden of keratinocyte carcinomas than previously documented.

Topical tretinoin therapy and all-cause mortality.

OBJECTIVE: To evaluate the relation of topical tretinoin, a commonly used retinoid cream, with all-cause mortality in the Veterans Affairs Topical Tretinoin Chemoprevention Trial (VATTC). The planned outcome of this trial was risk of keratinocyte carcinoma, and systemic administration of certain retinoid compounds has been shown to reduce risk of this cancer but has also been associated with increased mortality risk among smokers. DESIGN: The VATTC Trial was a blinded randomized chemoprevention trial, with 2- to 6-year follow-up. Oversight was provided by multiple independent committees. SETTING: US Department of Veterans Affairs medical centers. Patients A total of 1131 veterans were randomized. Their mean age was 71 years. Patients with a very high estimated short-term risk of death were excluded. Interventions Application of tretinoin, 0.1%, or vehicle control cream twice daily to the face and ears. MAIN OUTCOME MEASURES: Death, which was not contemplated as an end point in the original study design. RESULTS: The intervention was terminated 6 months early because of an excessive number of deaths in the tretinoin-treated group. Post hoc analysis of this difference revealed minor imbalances in age, comorbidity, and smoking status, all of which were important predictors of death. After adjusting for these imbalances, the difference in mortality between the randomized groups remained statistically significant. CONCLUSIONS: We observed an association of topical tretinoin therapy with death, but we do not infer a causal association that current evidence suggests is unlikely.

Multiplex cytokine profiling of initial therapeutic response in patients with chronic hepatitis C virus infection.

Currently available prognostic tools are inadequate to discern the molecular basis of the heterogenic response in hepatitis C virus (HCV)-infected patients treated with the current standard of therapy. The expression and biological function of immune mediators have been shown to be critical in all phases of the immune response to HCV infection and likely therefore influence host response. Herein, a biometric multiplex serum cytokine assay was utilized to characterize the immunomodulatory effects of host response in 10 HCV patients. Serum levels of 17 cytokines were compared before and after 1 month of treatment and against controls. Overall serum cytokine levels were significantly higher in patients (P < 0.05) than controls. Additionally, viral titers decreased in all patients after 1 month of therapy, as did overall serum cytokine levels in the cohort (P < 0.05). To assess relationships between changes in cytokine levels and changes in viral titer, the cohort was divided into three statistically distinct subgroups based on changes in viral titers. Specific sets of cytokines decreased in each group: decreases in CCL4, interleukin (IL)-2, CXCL8, and IL-1beta correlated with the greatest drops in viral titer, decreases in IL-5, granulocyte colony stimulating factor (G-CSF), and CCL4 correlated with moderate drops in viral titer, and only CCL2 correlated with the lowest drops in viral titer. Interestingly, decreases in CCL4 levels correlated with decreases in viral titers in all patients. CCL4 controls leukocyte influx and thus propagates inflammation. In conclusion, these data raise the possibility that characteristic changes in host response modulate the therapeutic response, demonstrating the prognostic power of serum cytokine profiling in chronic HCV.