Late Surge Research Articles

Timing of Thrombosis with Myeloproliferative Neoplasm Diagnosis Among Veterans and Civilians

Rates of Arterial (AT) and Venous Thrombosis (VT) are increased in Veterans with Myeloproliferative Neoplasms (Vet-MPN), including Essential Thrombocythemia (ET), Polycythemia Vera (PV), and Primary Myelofibrosis (PMF), compared to matched controls (J Clin Oncology 2023 41:16_suppl, 7011). The timing of first AT or VT episode in Vet-MPNs remains undefined when compared to Civilians with MPN (Civ-MPN). These findings could elucidate optimal timing for risk mitigation strategies to prevent thrombotic complications and should help to determine duration of thrombotic risk and need for systemic anticoagulation prophylaxis. The Veterans Affairs Informatics and Computing Infrastructure (VINCI) database was queried from January 1, 2006 to January 26, 2023 to identify Vet-MPNs, AT, and VT through ICD-9 and -10 codes. This process yielded 2,752 Vet-MPN and 583,803 Veterans without MPN from Illinois, the state most representative of the US population. These cohorts were compared to data derived from a retrospective chart review of Civ-MPN cared for between January 1, 2019 to December 31, 2022, at MedStar Georgetown University Hospital and MedStar Washington Hospital Center. Service-Connected Exposures (SCE) to potential carcinogens among Veterans were verified through their duration and location of service. We subdivided time to first AT and VT from MPN diagnosis as follows: more than 3 months prior to MPN diagnosis, within 3 months of diagnosis, 3 months to 1 year post diagnosis, 1 to 5 years, and more than 5 years after MPN diagnosis. Mean data from various cohorts were analyzed utilizing Fisher's exact test. Vet-MPN experienced a statistically higher incidence of AT compared to Civ-MPN (p=.0019) and Civ-MPN experienced a statistically higher incidence of AT compared to Veterans without MPN (p=0.02) which served as a control. In contrast, there was a higher incidence of VT among both Vet- and Civ-MPN cohorts compared to Veterans without MPN (p<.0001) (Table 1). The mean ages at MPN diagnosis and onset of first AT were similar (≥63 years) in both Civ- and Vet-MPN. In contrast, the mean age of MPN diagnosis and age of first VT were considerably earlier for Civ-MPN (51 years) versus both Vet-MPN with VT and Veterans without MPN with VT (≥67 years). There was a higher prevalence of hypertension, hyperlipidemia, diabetes, heart failure, and smoking among Veterans with or without MPN compared to Civ-MPN with either AT or VT (Table 1). A trend toward statistical significance was observed for the presence of hypertension and hyperlipidemia (p=0.049 and p=0.02, respectively) in Vet-MPN compared to Civ-MPN, while Veterans without MPN had a statistically higher prevalence of hyperlipidemia (p=0.02) and heart failure (p=0.001) in AT. Notably, a trend toward statistical significance in VT was observed for the presence of diabetes among all Veterans with or without MPN compared to Civ-MPN (p=0.01 and p=0.007, respectively). There was a biphasic distribution in time to onset of first AT and VT in all Vet- and Civ-MPN cohorts (Figure 1). There was a higher cumulative incidence of first AT and VT in Vet-MPN at more than 3 months prior to MPN diagnosis compared to Civ-MPN with AT and VT (Figure 1). On the other hand, the Civ-MPN cohort had a late surge of first VT more than 5 years after MPN diagnosis compared to the other MPN cohorts. A biphasic distribution in time to onset of first AT and VT was also observed among the Vet-MPN cohort when stratified by SCEs from World War II, the Korean War, the Vietnam War, and the Gulf War. The vast majority of both AT and VT in Vet-MPN from all SCE examined experienced onset of thrombotic events more than 3 months prior to MPN diagnosis. Most VT in Gulf War Vet-MPN occurred within 3 months of MPN diagnosis. In conclusion, the predominant risk for developing thrombotic complications in MPN, particularly in Vet-MPN, occurs in a biphasic pattern, beginning more than 3 months prior to MPN diagnosis and becoming apparent again at more than 5 years after MPN diagnosis. These findings suggest that the MPNs convey an enduring hypercoagulability potential throughout the natural history of the disease. There appears to be an accelerated onset of thrombotic complications earlier in the course of disease in Vet-MPN, perhaps reflecting their SCE with toxic carcinogens. More work is necessary to determine epigenetic influences on MPN natural history.

Who to escalate during a pandemic? A retrospective observational study about decision-making during the COVID-19 pandemic in the UK

BackgroundOptimal decision-making regarding who to admit to critical care in pandemic situations remains unclear. We compared age, Clinical Frailty Score (CFS), 4C Mortality Score and hospital mortality in two separate...

Mechanistic insight into the protective and pathogenic immune-responses against SARS-CoV-2.

COVID-19 is a severe respiratory illness that has emerged as a devasting health problem worldwide. The disease outcome is heterogeneous, which is most likely dependent on the immunity of an individual. Asymptomatic and mildly/moderate symptomatic (non-severe) patients likely develop an effective early immune response and clear the virus. However, severe symptoms dominate due to a failure in the generation of an effective and specific early immune response against SARS-CoV-2. Moreover, a late surge in pathogenic inflammation involves dysregulated innate and adaptive immune responses leading to local and systemic tissue damage and the emergence of severe disease symptoms. In this review, we describe the potential mechanisms of protective and pathogenic immune responses in "mild/moderate" and "severe" symptomatic SARS-CoV-2 infected people, respectively, and discuss the immune components that are currently targeted for therapeutic intervention.

CTLA4-Ig mediated immunosuppression favors immunotolerance and restores graft in mouse airway transplants

CTLA4-Ig is a potent costimulatory blocker that inhibits T cell activation during alloimmune inflammation and increases graft survival and function. CTLA4-Ig-mediated immunosuppression has been demonstrated to support transplant function in various clinical trials and preclinical settings, but its effects on the balance between regulatory T cells (Tregs) and effector T cells (Teffs), as well as complement activation, are less well investigated. In the present study, we proposed to investigate the effects of CTLA4-Ig mediated immunosuppression on the phase of immunotolerance and the subsequent graft microvascular and epithelial repair during the progression of subepithelial fibrosis in a mouse model of orthotopic trachea transplantation. Briefly, CTLA4-Ig treated allografts (2 mg/kg, I.P.), untreated allografts, and syngrafts were serially monitored for peripheral FOXP3+ Tregs, antibody-mediated complement activation (C3d and C4d), tissue oxygenation, donor-recipient microvascular blood flow, and subsequent tissue remodeling following transplantation. Our data demonstrate that CTLA4-Ig mediated immunosuppression significantly results in late increases in both peripheral CD4+/CD8+ FOXP3+ Tregs and serum IL-10, but prevents the microvascular deposition of IgG, complement factor C3d, and epithelial C4d respectively, which proportionally improved blood flow and tissue oxygenation in the graft and, thus, promotes graft repair. Also, it restored the airway lumen, epithelium, and prevented the progression of subepithelial collagen deposition up to 90 days after transplantation. This study demonstrates that CTLA4-Ig-mediated immunosuppression potentially modulates both effector response and a late surge of regulatory activity to preserve graft microvasculature and rescue allograft from sustained hypoxia and ischemia and thereby limits subepithelial fibrosis.

Elevated levels of circulating mitochondrial DNA predict early allograft dysfunction in patients following liver transplantation.

The role of circulating mitochondrial DNA (cmtDNA) in transplantation remains to be elucidated. cmtDNA may be released into the circulation as a consequence of liver injury; yet recent work also suggests a causative role for cmtDNA leading to hepatocellular injury. We hypothesized that elevated cmtDNA would be associated with adverse events after liver transplantation (LT) and conducted an observational cohort study. Twenty-one patients were enrolled prospectively prior to LT. Postoperative complications were observed in 47.6% (n=10). Seven patients (33.3%) had early allograft dysfunction (EAD), and six patients (28.5%) experienced acute cellular rejection within 6months of LT. cmtDNA levels were significantly elevated in all recipients after LT compared with healthy controls and preoperative samples (1361937 copies/mL [IQR 586781-3399687] after LT; 545531 copies/mL [IQR 238562-1381015] before LT; and 194562 copies/mL [IQR 182359-231515] in healthy controls) and returned to normal levels by 5days after transplantation. cmtDNA levels were particularly elevated in those who developed EAD in the early postoperative period (P<0.001). In all patients, there was initially a strong overall positive correlation between cmtDNA and plasma hepatocellular enzyme levels (P<0.05). However, the patients with EAD demonstrated a second peak in cmtDNA at postoperative day 7, which did not correlate with liver function tests. The early release of plasma cmtDNA is strongly associated with hepatocellular damage; however, the late surge in cmtDNA in patients with EAD appeared to be independent of hepatocellular injury as measured by conventional tests.

Optimal use of radiotherapy in the definitive treatment of non-bulky IB-IIA cervical cancer: A population-based long-term survival analysis.

PurposeAlthough current clinical guidelines recommend surgery or radiotherapy for non-bulky IB-IIA cervical cancer, clinical data supporting the curative role of radiotherapy in the early-stage disease are insufficient. We evaluated the prognostic implications of definitive radiotherapy and determined its optimal use in clinical practice.MethodsPatients with non-bulky (<4 cm) IB-IIA cervical cancer who underwent hysterectomy or primary radiotherapy between 1988 and 2015 were identified from the Surveillance, Epidemiology, and End Results database. Based on the use of brachytherapy and/or chemotherapy, the primary radiotherapy group was classified into three cohorts: hysterectomy vs. radiotherapy overall, with/without brachytherapy and/or chemotherapy (cohort A); radiotherapy and brachytherapy with/without chemotherapy (patients with external beam radiation alone were excluded, cohort B); radiotherapy with brachytherapy and chemotherapy (patients who did not receive chemotherapy were additionally excluded, cohort C). Disease-specific survival (DSS) after hysterectomy was compared to that after primary radiotherapy in each cohort.ResultsAmong the 9,391 initially identified patients, 1,762, 1,244, and 750 patients were classified into cohorts A, B, and C, respectively, after propensity score matching. In cohort A, DSS after primary radiotherapy was inferior to that after hysterectomy (P = 0.001). In cohort B, a trend toward differential survival in favor of hysterectomy was observed with marginal significance (P = 0.061). However, in cohort C, DSS after primary radiotherapy was not significantly different to that after hysterectomy (P = 0.127). According to hazard rate function plots, patients receiving external beam radiation alone had an increased short-term risk of disease-specific mortality, whereas patients without evidence of chemotherapy had a distinct late risk surge at approximately 15 years of follow-up.ConclusionOptimizing radiotherapy methods with brachytherapy and the use of chemotherapy should be considered for the long-term curative efficacy of primary radiotherapy for non-bulky IB-IIA cervical cancer. Further studies are warranted to corroborate our results.

Francis E. Hutchinson and Lee Hwok Aun, eds. The Defeat of Barisan Nasional: Missed Signs or Late Surge? Singapore: ISEAS Publishing, 2019.

Francis E. Hutchinson and Lee Hwok Aun, eds. The Defeat of Barisan Nasional: Missed Signs or Late Surge? Singapore: ISEAS Publishing, 2019.

Dynamics and Impacts of the May 8th, 1902 Pyroclastic Current at Mount Pelée (Martinique): New Insights From Numerical Modeling

The Mount Pelee May 8th, 1902 eruption is responsible for the deaths of more than 29,000 people, as well as the nearly-complete destruction of the city of Saint Pierre by a single pyroclastic current, and is, sadly, the deadliest eruption of the 20th century. Despite intensive field studies on the associated deposit, two conflicting interpretations of the pyroclastic current dynamics (either a blast or a simple ash-cloud surge) emerged in the 90’s and have been paralyzing research ever since, leaving numerous unknowns (i.e., source conditions, volume). This study is the first to investigate numerically the May 8th, 1902 pyroclastic current, using the new two-phase version of VolcFlow that simulates more accurately both parts of pyroclastic currents (i.e., the block-and-ash flow and the ash-cloud surge). Physical flow parameters are either extracted from field data or estimated empirically when no value was found in the literature. Among the two interpretations, only the simple ash-cloud surge is tested, generated from a block-andash flow initially supplied from the artificially recreated 1902 crater. The block-and-ash flow overflows from the southern V-shaped crater outlet and stays confined into the Riviere Blanche, whereas the ash-cloud surge expands radially and spreads westward, seaward, and eastward, ultimately reaching St Pierre 8 km away, within 330 s. The extent of both parts of the simulated current, as well as the thickness and the direction of the ash-cloud surge are accurately reproduced for a total volume of 32 106 m3, for which a significant part (one third) is deposited in the sea (not recorded in previous studies). Simulations demonstrate that the pear-like shape of the ash-cloud surge deposit is explained by a late surge production along the Riviere Blanche but also that a blast-like event may be required at the initial stage of the explosion, which in some way reconciles the two conflicting past interpretations. Results also highlight the role played by the topography in controlling transport and deposition mechanisms of such pyroclastic currents especially the lateral spreading of the ash-cloud surge. Our study improves the assessment of pyroclastic current-related hazards at Mount Pelee, which could be helpful for future eruptions.

Inhaled nebulized nitrite and nitrate therapy in a canine model of hypoxia-induced pulmonary hypertension

Dysfunction in the nitric oxide (NO) signaling pathway can lead to the development of pulmonary hypertension (PH) in mammals. Discovery of an alternative pathway to NO generation involving reduction from nitrate to nitrite and to NO has motivated the evaluation of nitrite as an alternative to inhaled NO for PH. In contrast, inhaled nitrate has not been evaluated to date, and potential benefits include a prolonged half-life and decreased risk of methemoglobinemia. In a canine model of acute hypoxia-induced PH we evaluated the effects of inhaled nitrate to reduce pulmonary arterial pressure (PAP). In a randomized controlled trial, inhaled nitrate was compared to inhaled nitrite and inhaled saline. Exhaled NO, PAP and systemic blood pressures were continuously monitored. Inhaled nitrite significantly decreased PAP and increased exhaled NO. In contrast, inhaled nitrate and inhaled saline did not decrease PAP or increase exhaled NO. Unexpectedly, we found that inhaled nitrite resulted in prolonged (>5 h) exhaled NO release, increase in nitrate venous/arterial levels and a late surge in venous nitrite levels. These findings do not support a therapeutic role for inhaled nitrate in PH but may have therapeutic implications for inhaled nitrite in various disease states.

Early Expansion of CD56dim NKG2Alow with Late Surge and Persistence of CD56dimNKG2AnegNKG2Cbright NK Cells Attenuate Cytomegalovirus (CMV) Replication and Recurrence As Well As Leukemia Relapse Following Haploidentical HSCT with T Cell Co-Stimulation Blockade and Ptcy

CMV related morbidity and mortality remains a major limiting factor in Haploidentical HSCT. We have developed a novel approach to Haploidentical PBSCT combining T cell Costimulation Blockade (T-COSB) with PTCy and Cyclosporine or Sirolimus (BBMT 2018). We studied the pattern of CMV reactivation (CMV-R) and its progression in 60 patients undergoing Haploidentical HSCT in this protocol in relation to the kinetics of Immune Reconstitution (IR) and pattern of leukemia relapse. PCR based CMV monitoring was carried out until 180 days with preemptive anti-CMV therapy. All patients and donors were CMV seropositive. CMV-R was 54.2% with median onset at 32 days (14-75) in the study group [compared to 52.5% in 42 who had received PTCy alone (p=0.8)]. The median peak viral load was 5.7 × 103/ml (1.8-25.8). The median duration of anti-CMV therapy was 16 days (7-60 days). There was no recurrence noted before100 days and only 2/32 (6.2%) beyond 100 days with no CMV disease. CMV-R was higher in those transplanted for malignant diseases compared to non-malignant diseases (62.5% vs 8.2%, p=0.01). Analysis of IR in relation to CMV-R showed no difference in CD3 or CD4+T cell reconstitution. However, CD56dimCD16+ NK cells at D+60 were significantly higher in patients without CMV-R (median 95 vs 45 cells/µl, p=0.02) and the same population of cells were associated with lower peak of viral load (p=0.04). In those with a lower viral peak and lower duration of viral replication, CD56dimCD16+ NK cells had a higher KIR repertoire with lower NKG2A expression. In those with CMV-R, a subsequent surge in absolute NK cells was observed (median 188 vs 112 cells/µl, p=0.01). This was primarily contributed by massive expansion of CD56dimNKG2AnegNKG2Cbright NK cells (median 7.8% [5-14.6%] at day +30 to 35% [28-65%] at day +90, p=0.01, Fig 1). This phenomenon was not witnessed in patients treated with PTCy alone. Peak viral load inversely correlated with NKG2C+ NK cells and CD45RO+CD8+ T cells at day +90 (p=0.03). The incidence of aGVHD (10.2%), cGVHD (18%), NRM (9.5%), and overall survival (75.8%) were not influenced by CMV-R. Incidence of relapse was 23.5 % at 28-144 days (median 85 days). However, none of the patients who relapsed before 100 days had proliferation of NKG2C+ NK cells and only 1/38 patients with proliferation and persistence of this subpopulation beyond 100 days experienced leukemia relapse at a median follow-up of 18 months (p=0.01). The kinetics of NK cell reconstitution in relation to the pattern of viral replication suggests that an early surge of CD56dimNKG2Alow NK cells with cytotoxic potential is responsible for the initial containment of viral replication followed by late surge and persistence of memory type NKG2C+NK cells preventing late recurrence as well as leukemia relapse. This unique synaptic response was possibly responsible for improved outcome with this novel approach of T-COSB based haploidentical HSCT.

Methods for the evaluation of biomarkers in patients with kidney and liver diseases: multicentre research programme including ELUCIDATE RCT

BackgroundProtein biomarkers with associations with the activity and outcomes of diseases are being identified by modern proteomic technologies. They may be simple, accessible, cheap and safe tests that can inform diagnosis, prognosis, treatment selection, monitoring of disease activity and therapy and may substitute for complex, invasive and expensive tests. However, their potential is not yet being realised.Design and methodsThe study consisted of three workstreams to create a framework for research: workstream 1, methodology – to define current practice and explore methodology innovations for biomarkers for monitoring disease; workstream 2, clinical translation – to create a framework of research practice, high-quality samples and related clinical data to evaluate the validity and clinical utility of protein biomarkers; and workstream 3, the ELF to Uncover Cirrhosis as an Indication for Diagnosis and Action for Treatable Event (ELUCIDATE) randomised controlled trial (RCT) – an exemplar RCT of an established test, the ADVIA Centaur® Enhanced Liver Fibrosis (ELF) test (Siemens Healthcare Diagnostics Ltd, Camberley, UK) [consisting of a panel of three markers – (1) serum hyaluronic acid, (2) amino-terminal propeptide of type III procollagen and (3) tissue inhibitor of metalloproteinase 1], for liver cirrhosis to determine its impact on diagnostic timing and the management of cirrhosis and the process of care and improving outcomes.ResultsThe methodology workstream evaluated the quality of recommendations for using prostate-specific antigen to monitor patients, systematically reviewed RCTs of monitoring strategies and reviewed the monitoring biomarker literature and how monitoring can have an impact on outcomes. Simulation studies were conducted to evaluate monitoring and improve the merits of health care. The monitoring biomarker literature is modest and robust conclusions are infrequent. We recommend improvements in research practice. Patients strongly endorsed the need for robust and conclusive research in this area. The clinical translation workstream focused on analytical and clinical validity. Cohorts were established for renal cell carcinoma (RCC) and renal transplantation (RT), with samples and patient data from multiple centres, as a rapid-access resource to evaluate the validity of biomarkers. Candidate biomarkers for RCC and RT were identified from the literature and their quality was evaluated and selected biomarkers were prioritised. The duration of follow-up was a limitation but biomarkers were identified that may be taken forward for clinical utility. In the third workstream, the ELUCIDATE trial registered 1303 patients and randomised 878 patients out of a target of 1000. The trial started late and recruited slowly initially but ultimately recruited with good statistical power to answer the key questions. ELF monitoring altered the patient process of care and may show benefits from the early introduction of interventions with further follow-up. The ELUCIDATE trial was an ‘exemplar’ trial that has demonstrated the challenges of evaluating biomarker strategies in ‘end-to-end’ RCTs and will inform future study designs.ConclusionsThe limitations in the programme were principally that, during the collection and curation of the cohorts of patients with RCC and RT, the pace of discovery of new biomarkers in commercial and non-commercial research was slower than anticipated and so conclusive evaluations using the cohorts are few; however, access to the cohorts will be sustained for future new biomarkers. The ELUCIDATE trial was slow to start and recruit to, with a late surge of recruitment, and so final conclusions about the impact of the ELF test on long-term outcomes await further follow-up. The findings from the three workstreams were used to synthesise a strategy and framework for future biomarker evaluations incorporating innovations in study design, health economics and health informatics.Trial registrationCurrent Controlled Trials ISRCTN74815110, UKCRN ID 9954 and UKCRN ID 11930.FundingThis project was funded by the NIHR Programme Grants for Applied Research programme and will be published in full inProgramme Grants for Applied Research; Vol. 6, No. 3. See the NIHR Journals Library website for further project information.

The structural, geometric and volumetric changes of a polythermal Arctic glacier during a surge cycle: Comfortlessbreen, Svalbard

AbstractVarious parameters of the most recent surge of the polythermal glacier Comfortlessbreen in northwest Svalbard, have been assessed through a combination of remote sensing and ground observations. Analysis of a digital elevation model time‐series shows a marked change in the geometry of the glacier from quiescence (1990 and earlier) into the late surge phase (2009). The transfer of 0.74 km3 of ice caused up to 80 m of surface drawdown in the reservoir area, above the equilibrium line, whilst ice built up in a spatially concentrated manner in the receiving zone, below the equilibrium line. A ramp of ice, c. 100 m above quiescent level, developed in the lower reaches of the glacier late in the surge. Also in the lower reaches of the glacier, structures attributable to the passage of a kinematic wave are identified and the migration of a surge front on the glacier is thus inferred. In a conceptual model, we consider that a bend in the valley, in which the glacier resides, and convergence with tributary glaciers, to be significant factors in the style of surge evolution. Their flow‐restrictive interference results in slow initial mass‐transfer and the growth of a surge front within 3–4 km of the terminus. Copyright © 2015 John Wiley &amp; Sons, Ltd.

PATRICK MODIANO: 'A MARCEL PROUST OF OUR TIME'?

The winner of the 2014 Nobel Prize for Literature was, in more ways than one, Patrick Modiano. Typically, the publicity-shy novelist had crept in under the radar, despite a late surge in the betting, and had even proved hard to locate once the decision had been taken. In terms of his artistic achievements, however, the Nobel Academy had no trouble in pinning him down. He was, their spokesman, Peter Englund, asserted, a ‘Marcel Proust of our time’.1 It is the aim of the present article briefly to explore this notion, and to evaluate just how apposite an assessment it is.

J. G. Ballard: Visions and Revisions

In 2009, the University of East Anglia hosted a conference on the work of J. G. Ballard. Although the late surge of academic interest in Ballard's work was already partially underway, it was nonetheless encouraging that the number of scholars and enthusiasts who attended the event, not just from Britain but from around the globe, warranted two days of parallel panels. Those present fell roughly into two camps: those who openly celebrated their enjoyment of Ballard's writing (including Rick McGrath, David Pringle, and Simon Sellars) and those who still insisted on feigning a mild disinterest in, or distaste for, the author. There is still some uncertainty in intellectual circles as to whether or not we should see Ballard as a respectable figure, and this leads to a tendency to participate in a rather guilty indulgence in his work which is hard to admit to, even in an environment filled with similarly interested people. The academic legitimization of Ballard's work has taken a considerable amount of time; Roger Luckhurst's quirky and intriguing The Angle Between Two Walls stood, for some years, as the only study of the author that deserved any real credibility. That work, with its idiosyncratic approach, was far from comprehensive in its treatment of Ballard's oeuvre, but it served to demonstrate a critical potential that was, to that point, going largely untapped. Since then, the floodgates have, it seems, opened, and there is now a wealth of quality material devoted to Ballard's extensive career. Jeanette Baxter, co-editor of this latest collection of essays from Palgrave, is an established expert on Ballard's work, having convened the UEA conference and having also produced a significant monograph and a further edited volume on the author. It is perhaps no surprise, then, that she has managed, both at the conference and here (with co-editor Rowland Wymer), to attract contributions from a number of the leading names in the field, including Luckhurst, Simon Sellars, David Ian Paddy, and David James.

Systemic PPARγ Ligation Inhibits Allergic Immune Response in the Skin

We have shown previously that specific ligands of the peroxisome proliferator-activated receptor-gamma (PPARgamma) inhibit the systemic allergic immune response. The objective of this study was to investigate the impact of PPARgamma-ligand treatment on the local allergic immune response. We established a murine model exhibiting clinical and histological features of AD-like skin lesions with high reproducibility. In this model, the PPARgamma ligand was applied in an either preventive or therapeutic manner via systemic and local routes. The affected skin areas were assessed by standardized skin score, histological analyses, and immunohistochemical examinations. Our data show that systemic application of PPARgamma ligand by a preventive protocol led to significantly reduced onset of eczematous skin lesions. This was confirmed by histology, showing decreased skin thickness accompanied by significantly reduced infiltrations of CD4+ and CD8+ lymphocytes but also mast cells. Additionally, early allergen-specific IgE and IgG1 responses were reduced (day 21/35), whereas IgG2a levels remained unchanged. In conclusion, our results demonstrate that PPARgamma-ligand treatment inhibits not only systemic allergic immune response, but also local allergen-mediated dermatitis. Our findings point to therapeutic strategies, including a PPARgamma-ligand-based treatment.

CCL27 is a critical factor for the development of atopic dermatitis in the keratin-14 IL-4 transgenic mouse model

The keratin-14 IL-4 transgenic (Tg) mouse model of atopic dermatitis (AD) is characterized by skin infiltration of T cells, early up-regulation of T(h)2 cytokines and late surge of T(h)1 cytokines. In the present study, we investigated the role of CCL27, a T cell skin-homing chemokine known to be elevated in sera of human AD patients, in disease development in our animal model of AD. The results showed that the mRNA and protein levels of CCL27 in the skin and serum were significantly increased in IL-4 Tg mice. The percentage of T cells expressing CCR10 in skin draining lymph nodes of IL-4 Tg mice was increased, consistent with the findings of >80% of skin-infiltrating T cells in Tg mice expressing CCR10. Chemotaxis transmigration assay demonstrated that CCL27 promotes a greater degree of migration of T cells in diseased Tg mice. Subcutaneous injection of neutralizing anti-CCL27 to IL-4 Tg mice with early skin lesions resulted in reduced clinical progression of inflammation, accompanied with decreased T cell and mast cell infiltration in the skin, and down-regulation of inflammatory cytokines. In conclusion, CCL27 and CCR10 interaction is important for the development of skin inflammation in our AD model.

The disease progression in the keratin 14 IL-4-transgenic mouse model of atopic dermatitis parallels the up-regulation of B cell activation molecules, proliferation and surface and serum IgE

We have previously characterized the keratin 14 interleukin-4-transgenic (IL-4-Tg) mouse model of atopic dermatitis as a chronic pruritic inflammatory skin disease typified by skin infiltration of inflammatory cells and early up-regulation of Th2 cytokines and late surge of Th1 cytokines. In the present study, we examined the involvement of B cells. Systematic examinations of the following immunological parameters on B cells were carried out in non-Tg control mice and in IL-4-Tg mice at before disease onset and early and late disease stages so that we could determine the immunological sequence of events leading to the disease development: surface expressions of IA/IE, activation and costimulatory molecules, proliferation under LPS or IgM stimulation, quantification of cell surface and serum IgE, IgG1, and IgG2a. Our results showed that as the disease progresses from before onset to early disease and to late disease, there is a parallel increase in surface markers of B cell activation (IA/IE, CD44, CD69, CD80 and CD86), in B cell proliferation, and in cell surface and serum IgE. Significant increases of Th2-driven serum IgG1 and IgE in early disease was followed by significant increase of Th1-driven IgG2a in late disease. Importantly the significant increases of activation molecule (IA/IE), proliferation (to LPS), and surface IgE on B cells of the IL-4-Tg mice precedes the up-regulation of serum IgE and disease onset. These data suggest that activated B cells may play a role in atopic dermatitis disease development by up-regulating serum IgE concentration, which serves as a marker of disease onset.

Early up-regulation of Th2 cytokines and late surge of Th1 cytokines in an atopic dermatitis model

We investigated cytokine profiles in interleukin (IL)-4 transgenic (Tg) mice with a skin inflammatory disease resembling human atopic dermatitis. cDNA microarray revealed that the mRNAs encoding IL-1beta, IL-2, IL-3, IL-4, IL-5, IL-6, IL-10, IL-12p40, IL-13, tumour necrosis factor (TNF)-alpha, TNF-beta and interferon (IFN)-gamma were up-regulated in the skin of late lesion Tg mice and to a lesser degree in non-lesion Tg mice when compared to those of non-Tg mice. Real time reverse transcription-polymerase chain reaction (RT-PCR) analyses indicated that the cDNA copy numbers of IL-1beta, IL-4, IL-6, IL-10, TNF-alpha and IFN-gamma from the skin of late, early and non-lesions increased significantly compared to non-Tg mice. IL-2 and IL-12p40 cDNA copy numbers were increased significantly in early, but not late, lesions. Interestingly, IL-1beta, IL-3, IL-4, IL-5, IL-6, IL-10, IL-13, TNF-alpha, and IFN-gamma cDNAs were increased significantly the skin of before-onset and/or non-lesion mice. Flow cytometry analyses demonstrated an increased percentage of keratinocytes producing IL-4 as the disease progressed. The percentage of IL-2, IL-4, IL-10 and IFN-gamma-producing T cells and IL-12-producing antigen-presenting cells in skin-draining lymph nodes and inflammatory skin also increased, particularly in mice with late lesion. These results suggest that disease induction is primarily triggered by Th2 cytokines and that Th1, Th2 and non-Th proinflammatory cytokines are all involved in the disease process.

Decrease in gonadotropin-releasing hormone (GnRH) pulse frequency with aging in postmenopausal women.

Increasing evidence suggests that aging is associated with dynamic changes in the hypothalamic and pituitary components of the reproductive axis that are independent of changes in gonadal hormone secretion. This study was designed to determine the effect of age on GnRH pulse frequency in women in the absence of gonadal feedback using gonadotropin free alpha-subunit (FAS) and LH as neuroendocrine markers of endogenous GnRH secretion. All studies were performed in healthy, euthyroid postmenopausal women (PMW) during daytime hours. The impact of sampling interval and duration on assessment of pulse frequency in PMW was first examined in 10 women with a mean age of 61.6 +/- 8 yr (mean +/- SD), in whom blood was sampled every 5 min for 12 h. Each 5-min series was then reduced to simulate a 10-min series and then a 15-min series for pulse analysis, and the effect of 8 h compared with 12 h of sampling was determined. To define the changes in the frequency and amplitude of pulsatile hormone secretion with aging, 11 younger (45-55 yr) and 11 older (70-80 yr) PMW were then studied over 8 h at a 5-min sampling interval. In the initial series, the mean interpulse intervals (IPIs) for FAS were 53.8 +/- 3.6, 69.2 +/- 3.9, and 87.6 +/- 7.3 min at sampling intervals of 5, 10, and 15 min, respectively (P < 0.0005). The LH IPI also increased progressively with sampling intervals of 5, 10, and 15 min (54.4 +/- 2.5, 70.4 +/- 2.3, and 91.1 +/- 4.4 min; P < 0.0001). At the 5-min sampling interval, the calculated number of pulses/24 h was not different between a 12-h series compared with an 8-h series for either FAS or LH. In the second series of studies, the older PMW had lower gonadotropin levels (LH, 86.5 +/- 8.8 vs. 51.3 +/- 7.7 IU/L, P < 0.01; FSH, 171.6 +/- 16.9 vs. 108.2 +/- 10.5 IU/L, P < 0.005; FAS, 1021.5 +/- 147.4 vs. 425.6 +/- 89.6 ng/L, P < 0.005, in younger and older PMW, respectively) despite no differences in estrone or estradiol levels. The older PMW also demonstrated a slower FAS pulse frequency compared with their younger counterparts, as reflected in an increased FAS IPI (52.6 +/- 3.1 and 70.6 +/- 5.9 min; P < 0.002). The difference in IPIs between younger and older PMW was not statistically significant for LH (65.4 +/- 5.6 and 71.8 +/- 6.6 min for younger and older PMW, respectively). FAS pulse amplitude was decreased in older PMW compared with younger PMW (431.7 +/- 66.2 vs. 224.6 +/- 81.9 ng/L; P < 0.01), whereas the decrease in LH pulse amplitude with age was of borderline statistical significance (23.2 +/- 3.1 vs. 15.9 +/- 2.1 IU/L; P = 0.09). 1) the use of a 5-min sampling interval and measurement of FAS as the primary marker of GnRH pulse generator activity indicate that GnRH pulse frequency in younger PMW is faster than previously reported, but not increased over that seen in the late follicular phase and midcycle surge in women with intact ovarian function; and 2) the marked decrease in FAS pulse frequency with age provides evidence of age-related changes in the hypothalamic component of the reproductive axis that are independent of changes in gonadal function.

Changes in calcium and iron levels in the brains of rats during kainate induced epilepsy

Epilepsy is a recurrent disorder of cerebral function characterised by sudden brief attacks of altered consciousness, motor activity or sensory phenomena, and affects approximately 1% of the population. Kainic acid injection induces neuronal degeneration in rats, is associated with glial hypertrophy and proliferation in the CA3–CA4 fields of hippocampal complex, and is a model for temporal lobe epilepsy. In this study we have applied Nuclear Microscopy to the investigation of the elemental changes within the hippocampus and the cortex areas of the rat brain following kainate injection. Analyses of unstained freeze dried tissue sections taken at 1 day and 1, 2, 3 and 4 weeks following injection were carried out using the Nuclear Microscopy facility at the Research Centre for Nuclear Microscopy, National University of Singapore. Quantitative analysis and elemental mapping indicates that there are significant changes in the calcium levels and distributions in the hippocampus as early as 1 day following injection. Preliminary results indicate a rapid increase in cellular calcium. High levels of calcium can activate calcium dependent proteins and phospholipases. Activation of phospholipase A2 can be harmful to surrounding neurons through free radical damage. In addition to observed increases in calcium, there was evidence of increases in iron levels. This is consistent with measurements in other degenerative brain disorders, and may signal a late surge in free radical production.