Functional Adaptation in Female Rats: The Role of Estrogen Signaling

Background

Sex steroids have direct effects on the skeleton. Estrogen acts on the skeleton via the classical genomic estrogen receptors alpha and beta (ERα and ERβ), a membrane ER, and the non-genomic G-protein coupled estrogen receptor (GPER). GPER is distributed throughout the nervous system, but little is known about its effects on bone. In male rats, adaptation to loading is neuronally regulated, but this has not been studied in females.

Methodology/Principal Findings

We used the rat ulna end-loading model to induce an adaptive modeling response in ovariectomized (OVX) female Sprague-Dawley rats. Rats were treated with a placebo, estrogen (17β-estradiol), or G-1, a GPER-specific agonist. Fourteen days after OVX, rats underwent unilateral cyclic loading of the right ulna; half of the rats in each group had brachial plexus anesthesia (BPA) of the loaded limb before loading. Ten days after loading, serum estrogen concentrations, dorsal root ganglion (DRG) gene expression of ERα, ERβ, GPER, CGRPα, TRPV1, TRPV4 and TRPA1, and load-induced skeletal responses were quantified. We hypothesized that estrogen and G-1 treatment would influence skeletal responses to cyclic loading through a neuronal mechanism. We found that estrogen suppresses periosteal bone formation in female rats. This physiological effect is not GPER-mediated. We also found that absolute mechanosensitivity in female rats was decreased, when compared with male rats. Blocking of adaptive bone formation by BPA in Placebo OVX females was reduced.

Conclusions

Estrogen acts to decrease periosteal bone formation in female rats in vivo. This effect is not GPER-mediated. Gender differences in absolute bone mechanosensitivity exist in young Sprague-Dawley rats with reduced mechanosensitivity in females, although underlying bone formation rate associated with growth likely influences this observation. In contrast to female and male rats, central neuronal signals had a diminished effect on adaptive bone formation in estrogen-deficient female rats.     

Pathogenesis of age-related osteoporosis: impaired mechano-responsiveness of bone is not the culprit

Background

According to prevailing understanding, skeletal mechano-responsiveness declines with age and this apparent failure of the mechano-sensory feedback system has been attributed to the gradual bone loss with aging (age-related osteoporosis). The objective of this study was to evaluate whether the capacity of senescent skeleton to respond to increased loading is indeed reduced as compared to young mature skeleton.

Methods and Findings

108 male and 101 female rats were randomly assigned into Exercise and Control groups. Exercise groups were subjected to treadmill training either at peak bone mass between 47–61 weeks of age (Mature) or at senescence between 75–102 weeks of age (Senescent). After the training intervention, femoral necks and diaphysis were evaluated with peripheral quantitative computed tomography (pQCT) and mechanical testing; the proximal tibia was assessed with microcomputed tomography (μCT). The μCT analysis revealed that the senescent bone tissue was structurally deteriorated compared to the mature bone tissue, confirming the existence of age-related osteoporosis. As regards the mechano-responsiveness, the used loading resulted in only marginal increases in the bones of the mature animals, while significant exercise-induced increases were observed virtually in all bone traits among the senescent rats.

Conclusion

The bones of senescent rats displayed a clear ability to respond to an exercise regimen that failed to initiate an adaptive response in mature animals. Thus, our observations suggest that the pathogenesis of age-related osteoporosis is not attributable to impaired mechano-responsiveness of aging skeleton. It also seems that strengthening of even senescent bones is possible – naturally provided that safe and efficient training methods can be developed for the oldest old.     

Receptor activator of NF-kB (RANK) expression in primary tumors associates with bone metastasis occurrence in breast cancer patients

Background

Receptor activator of NFkB (RANK), its ligand (RANKL) and the decoy receptor of RANKL (osteoprotegerin, OPG) play a pivotal role in bone remodeling by regulating osteoclasts formation and activity. RANKL stimulates migration of RANK-expressing tumor cells in vitro, conversely inhibited by OPG.

Materials and Methods

We examined mRNA expression levels of RANKL/RANK/OPG in a publicly available microarray dataset of 295 primary breast cancer patients. We next analyzed RANK expression by immunohistochemistry in an independent series of 93 primary breast cancer specimens and investigated a possible association with clinicopathological parameters, bone recurrence and survival.

Results

Microarray analysis showed that lower RANK and high OPG mRNA levels correlate with longer overall survival (P = 0.0078 and 0.0335, respectively) and disease-free survival (P = 0.059 and 0.0402, respectively). Immunohistochemical analysis of RANK showed a positive correlation with the development of bone metastases (P = 0.023) and a shorter skeletal disease-free survival (SDFS, P = 0.037). Specifically, univariate analysis of survival showed that “RANK-negative” and “RANK-positive” patients had a SDFS of 105.7 months (95% CI: 73.9–124.4) and 58.9 months (95% CI: 34.7–68.5), respectively. RANK protein expression was also associated with accelerated bone metastasis formation in a multivariate analysis (P = 0.029).

Conclusions

This is the first demonstration of the role of RANK expression in primary tumors as a predictive marker of bone metastasis occurrence and SDFS in a large population of breast cancer patients.     

Efficacy and safety of abciximab in diabetic patients who underwent percutaneous coronary intervention with thienopyridines loading: a meta-analysis

Background

It has been controversial whether abciximab offered additional benefits for diabetic patients who underwent percutaneous coronary intervention (PCI) with thienopyridines loading.

Methods

MEDLINE, EMBASE, the Cochrane library clinical trials registry, ISI Science Citation Index, ISI Web of Knowledge and China National Knowledge Infrastructure (CNKI) were searched, supplemented with manual-screening for relevant publications. Quantitative meta-analyses were performed to assess differences between abciximab groups and controls with respect to post-PCI risk of major cardiac events (MACEs), angiographic restenosis and bleeding complications.

Results

9 trials were identified, involving 2,607 diabetic patients receiving PCI for coronary artery diseases. Among those patients who underwent elective PCI or primary PCI, pooling results showed that abciximab did not significantly reduce risks of MACEs (for elective-PCI patients: RR_1-month: 0.93, 95% CI: 0.60–1.44; RR_1-year: 0.95, 95% CI: 0.81–1.11; for primary-PCI patients: RR_1-month: 1.05, 95% CI: 0.70–1.57; RR_1-year: 0.98, 95% CI: 0.80–1.21), nor all-cause mortality, re-infarction and angiographic restenosis in either group. The only beneficial effect by abciximab appeared to be a decrease 1-year TLR (target lesion revascularization) risk in elective-PCI patients (RR1-year: 0.83, 95% CI: 0.70–0.99). Moreover, occurrence of minor bleeding complications increased in elective-PCI patients treated with abciximab (RR: 2.94, 95% CI: 1.68–5.13, P<0.001), whereas major bleedings rate was similar (RR: 0.83, 95% CI: 0.27–2.57).

Conclusions

Concomitant dosing of abciximab and thienopyridines provides no additional benefit among diabetic patients who underwent PCI; this conclusion, though, needs further confirmation in larger studies.     

Association between insomnia symptoms and hemoglobin A1c level in Japanese men

Background

The evidence for an association between insomnia symptoms and blood hemoglobin A_1c (HbA_1c) level has been limited and inconclusive. The aim of this study was to assess whether each symptom of initial, middle, and terminal insomnia influences HbA_1c level in Japanese men.

Methods

This cross-sectional study examined 1,022 male workers aged 22–69 years with no history of diabetes at a Japanese company''s annual health check-up in April 2010. High HbA_1c was defined as a blood level of HbA_1c ≥6.0%. Three types of insomnia symptoms (i.e., difficulty in initiating sleep, difficulty in maintaining sleep, and early morning awakening) from the previous month were assessed by 3 responses (i.e., lasting more than 2 weeks, sometimes, and seldom or never [reference group]).

Results

The overall prevalence of high HbA_1c was 5.2%. High HbA_1c was positively and linearly associated with both difficulty in maintaining sleep (P for trend  = .002) and early morning awakening (P for trend  = .007). More specifically, after adjusting for potential confounding factors, high HbA_1c was significantly associated with difficulty in maintaining sleep lasting more than 2 weeks (adjusted odds ratio, 6.79 [95% confidence interval, 1.86–24.85]) or sometimes (2.33 [1.19–4.55]). High HbA_1c was also significantly associated with early morning awakening lasting more than 2 weeks (3.96 [1.24–12.59]).

Conclusion

Insomnia symptoms, particularly difficulty in maintaining sleep and early morning awakening, were found to have a close association with high HbA_1c in a dose-response relationship.     

A functional polymorphism in renalase (Glu37Asp) is associated with cardiac hypertrophy, dysfunction, and ischemia: data from the heart and soul study

Background

Renalase is a soluble enzyme that metabolizes circulating catecholamines. A common missense polymorphism in the flavin-adenine dinucleotide-binding domain of human renalase (Glu37Asp) has recently been described. The association of this polymorphism with cardiac structure, function, and ischemia has not previously been reported.

Methods

We genotyped the rs2296545 single-nucleotide polymorphism (Glu37Asp) in 590 Caucasian individuals and performed resting and stress echocardiography. Logistic regression was used to examine the associations of the Glu37Asp polymorphism (C allele) with cardiac hypertrophy (LV mass>100 g/m2), systolic dysfunction (LVEF<50%), diastolic dysfunction, poor treadmill exercise capacity (METS<5) and inducible ischemia.

Results

Compared with the 406 participants who had GG or CG genotypes, the 184 participants with the CC genotype had increased odds of left ventricular hypertrophy (OR = 1.43; 95% CI 0.99–2.06), systolic dysfunction (OR = 1.72; 95% CI 1.01–2.94), diastolic dysfunction (OR = 1.75; 95% CI 1.05–2.93), poor exercise capacity (OR = 1.61; 95% CI 1.05–2.47), and inducible ischemia (OR = 1.49, 95% CI 0.99–2.24). The Glu37Asp (CC genotype) caused a 24-fold decrease in affinity for NADH and a 2.3-fold reduction in maximal renalase enzymatic activity.

Conclusions

A functional missense polymorphism in renalase (Glu37Asp) is associated with cardiac hypertrophy, ventricular dysfunction, poor exercise capacity, and inducible ischemia in persons with stable coronary artery disease. Further studies investigating the therapeutic implications of this polymorphism should be considered.     

Physiological correlates of endurance time variability during constant-workrate cycling exercise in patients with COPD

Rationale

The endurance time (T_end) during constant-workrate cycling exercise (CET) is highly variable in COPD. We investigated pulmonary and physiological variables that may contribute to these variations in T_end.

Methods

Ninety-two patients with COPD completed a CET performed at 80% of peak workrate capacity (W_peak). Patients were divided into tertiles of T_end [Group 1: <4 min; Group 2: 4–6 min; Group 3: >6 min]. Disease severity (FEV₁), aerobic fitness (W_peak, peak oxygen consumption [ _peak], ventilatory threshold [ _VT]), quadriceps strength (MVC), symptom scores at the end of CET and exercise intensity during CET (heart rate at the end of CET to heart rate at peak incremental exercise ratio [HR_CET/HR_peak]) were analyzed as potential variables influencing T_end.

Results

W_peak, _peak, _VT, MVC, leg fatigue at end of CET, and HR_CET/HR_peak were lower in group 1 than in group 2 or 3 (p≤0.05). _VT and leg fatigue at end of CET independently predicted T_end in multiple regression analysis (r = 0.50, p = 0.001).

Conclusion

T_end was independently related to the aerobic fitness and to tolerance to leg fatigue at the end of exercise. A large fraction of the variability in T_end was not explained by the physiological parameters assessed in the present study. Individualization of exercise intensity during CET should help in reducing variations in T_end among patients with COPD.     

Socioeconomic status and incident type 2 diabetes mellitus: data from the Women's Health Study

Objectives

We prospectively examined whether socioeconomic status (SES) predicts incident type II diabetes (diabetes), a cardiovascular risk equivalent and burgeoning public health epidemic among women.

Methods

Participants include 23,992 women with Hb_A1c levels <6% and no CVD or diabetes at baseline followed from February 1993 to March 2007. SES was measured by education and income while diabetes was self-reported.

Results

Over 12.3 years of follow-up, 1,262 women developed diabetes. In age and race adjusted models, the relative risk of diabetes decreased with increasing education (<2 years of nursing, 2 to <4 years of nursing, bachelor''s degree, master''s degree, and doctorate: 1.0, 0.7 [95% Confidence Interval (CI), 0.6–0.8], 0.6 (95% CI, 0.5–0.7), 0.5 (95% CI, 0.4–0.6), 0.4 (95% CI, 0.3–0.5); p_trend<0.001). Adjustment for traditional and non-traditional cardiovascular risk factors attenuated this relationship (education: p_trend = 0.96). Similar associations were observed between income categories and diabetes.

Conclusion

Advanced education and increasing income were both inversely associated with incident diabetes even in this relatively well-educated cohort. This relationship was largely explained by behavioral factors, particularly body mass index.     

Symptoms associated with an abnormal echocardiogram in elderly primary care hypertension patients

Background

The prevalence and diagnostic value of heart failure symptoms in elderly primary care patients with hypertension is unknown.

Aim

To assess the prevalence, sensitivity, specificity, positive and negative predictive value of symptoms in association with an abnormal echocardiogram.

Design and setting

Cross-sectional screening study in five general practices in the south-east of the Netherlands.

Method

Between June 2010 and January 2013, 591 primary care hypertension patients aged between 60 and 85 years were included, without known heart failure and not treated by a cardiologist. All patients underwent an echocardiogram and a structured interview including assessment of heart failure symptoms: shortness of breath, fatigue, oedema, cold extremities, and restless sleep.

Results and conclusion

Restless sleep was reported by 25 %, cold extremities by 23 %, fatigue by 19 %, shortness of breath by 17 %, and oedema by 13 %. Oedema was the only symptom significantly associated with an abnormal echocardiogram (positive predictive value was 45 %, sensitivity 20 %, and specificity 90 %, OR 2.12; 95 % CI = 1.23–3.64), apart from higher age (OR 1.06; 95 % CI = 1.03–1.09), previous myocardial infarction (OR 3.00; 95 % CI = 1.28–7.03), and a systolic blood pressure of >160 mmHg (OR 1.62; 95 % CI = 1.08–2.41). Screening with echocardiography might be considered in patients with oedema.     

Correlation of memory T cell responses against TRAP with protection from clinical malaria, and CD4 CD25 high T cells with susceptibility in Kenyans

Background

Immunity to malaria develops naturally in endemic regions, but the protective immune mechanisms are poorly understood. Many vaccination strategies aim to induce T cells against diverse pre-erythrocytic antigens, but correlates of protection in the field have been limited. The objective of this study was to investigate cell-mediated immune correlates of protection in natural malaria. Memory T cells reactive against thrombospondin-related adhesive protein (TRAP) and circumsporozoite (CS) protein, major vaccine candidate antigens, were measured, as were frequencies of CD4⁺ CD25^high T cells, which may suppress immunity, and CD56⁺ NK cells and γδ T cells, which may be effectors or may modulate immunity.

Methodology and Principal Findings

112 healthy volunteers living in rural Kenya were entered in the study. Memory T cells reactive against TRAP and CS were measured using a cultured IFNγ ELISPOT approach, whilst CD4⁺ CD25^high T cells, CD56⁺ NK cells, and γδ T cells were measured by flow cytometry. We found that T cell responses against TRAP were established early in life (<5 years) in contrast to CS, and cultured ELISPOT memory T cell responses did not correlate with ex-vivo IFNγ ELISPOT effector responses. Data was examined for associations with risk of clinical malaria for a period of 300 days. Multivariate logistic analysis incorporating age and CS response showed that cultured memory T cell responses against TRAP were associated with a significantly reduced incidence of malaria (p = 0.028). This was not seen for CS responses. Higher numbers of CD4⁺ CD25^high T cells, potentially regulatory T cells, were associated with a significantly increased risk of clinical malaria (p = 0.039).

Conclusions

These data demonstrate a role for central memory T cells in natural malarial immunity and support current vaccination strategies aimed at inducing durable protective T cell responses against the TRAP antigen. They also suggest that CD4⁺ CD25^high T cells may negatively affect naturally acquired malarial immunity.     

Normal SUV Values Measured from NaF18- PET/CT Bone Scan Studies

Objectives

Cancer and metabolic bone diseases can alter the SUV. SUV values have never been measured from healthy skeletons in NaF18-PET/CT bone scans. The primary aim of this study was to measure the SUV values from normal skeletons in NaF18-PET/CT bone scans.

Methods

A retrospective study was carried out involving NaF18- PET/CT bone scans that were done at our institution between January 2010 to May 2012. Our excluding criteria was patients with abnormal real function and patients with past history of cancer and metabolic bone diseases including but not limited to osteoporosis, osteopenia and Paget’s disease. Eleven studies met all the criteria.

Results

The average normal SUV_max values from 11 patients were: cervical vertebrae 6.84 (range 4.38–8.64), thoracic vertebrae 7.36 (range 6.99–7.66), lumbar vertebrae 7.27 (range 7.04–7.72), femoral head 2.22 (range 1.1–4.3), humeral head 1.82 (range 1.2–2.9), mid sternum 5.51 (range 2.6–8.1), parietal bone 1.71 (range 1.3–2.4).

Conclusion

According to our study, various skeletal sites have different normal SUV values. SUV values can be different between the normal bones and bones with tumor or metabolic bone disease. SUV can be used to quantify NaF-18 PET/CT studies. If the SUV values of the normal skeleton are known, they can be used in the characterization of bone lesions and in the assessment of treatment response to bone diseases.     

The Association between Histamine 2 Receptor Antagonist Use and Clostridium difficile Infection: A Systematic Review and Meta-analysis

Background

Clostridium difficile infection (CDI) is a major health problem. Epidemiological evidence suggests that there is an association between acid suppression therapy and development of CDI.

Purpose

We sought to systematically review the literature that examined the association between histamine 2 receptor antagonists (H₂RAs) and CDI.

Data source

We searched Medline, Current Contents, Embase, ISI Web of Science and Elsevier Scopus from 1990 to 2012 for all analytical studies that examined the association between H₂RAs and CDI.

Study selection

Two authors independently reviewed the studies for eligibility.

Data extraction

Data about studies characteristics, adjusted effect estimates and quality were extracted.

Data synthesis

Thirty-five observations from 33 eligible studies that included 201834 participants were analyzed. Studies were performed in 6 countries and nine of them were multicenter. Most studies did not specify the type or duration of H₂RAs therapy. The pooled effect estimate was 1.44, 95% CI (1.22–1.7), I² = 70.5%. This association was consistent across different subgroups (by study design and country) and there was no evidence of publication bias. The pooled effect estimate for high quality studies was 1.39 (1.15–1.68), I2 = 72.3%. Meta-regression analysis of 10 study-level variables did not identify sources of heterogeneity. In a speculative analysis, the number needed to harm (NNH) with H₂RAs at 14 days after hospital admission in patients receiving antibiotics or not was 58, 95% CI (37, 115) and 425, 95% CI (267, 848), respectively. For the general population, the NNH at 1 year was 4549, 95% CI (2860, 9097).

Conclusion

In this rigorous systematic review and meta-analysis, we observed an association between H₂RAs and CDI. The absolute risk of CDI associated with H₂RAs is highest in hospitalized patients receiving antibiotics.     

Effect of dust and anthropogenic aerosols on columnar aerosol optical properties over Darjeeling (2200 m asl), eastern Himalayas, India

Background

The loading of atmospheric particulate matter (aerosol) in the eastern Himalaya is mainly regulated by the locally generated anthropogenic aerosols from the biomass burning and by the aerosols transported from the distance sources. These different types of aerosol loading not only affect the aerosol chemistry but also produce consequent signature on the radiative properties of aerosol.

Methodology/Principal Findings

An extensive study has been made to study the seasonal variations in aerosol components of fine and coarse mode aerosols and black carbon along with the simultaneous measurements of aerosol optical depth on clear sky days over Darjeeling, a high altitude station (2200 masl) at eastern Himalayas during the year 2008. We observed a heavy loading of fine mode dust component (Ca²⁺) during pre-monsoon (Apr – May) which was higher by 162% than its annual mean whereas during winter (Dec – Feb), the loading of anthropogenic aerosol components mainly from biomass burning (fine mode SO₄ ²⁻ and black carbon) were higher (76% for black carbon and 96% for fine mode SO₄ ²⁻) from their annual means. These high increases in dust aerosols during pre-monsoon and anthropogenic aerosols during winter enhanced the aerosol optical depth by 25 and 40%, respectively. We observed that for every 1% increase in anthropogenic aerosols, AOD increased by 0.55% during winter whereas for every 1% increase in dust aerosols, AOD increased by 0.46% during pre-monsoon.

Conclusion/Significance

The natural dust transport process (during pre-monsoon) plays as important a role in the radiation effects as the anthropogenic biomass burning (during winter) and their differential effects (rate of increase of the AOD with that of the aerosol concentration) are also very similar. This should be taken into account in proper modeling of the atmospheric environment over eastern Himalayas.     

Lowered risk of nasopharyngeal carcinoma and intake of plant vitamin, fresh fish, green tea and coffee: a case-control study in taiwan

Background

A case-control study was conducted to evaluate the role of adult diet on nasopharyngeal carcinoma (NPC) in Taiwan.

Methods

A total of 375 incident NPC cases and 327 controls matched to the cases on sex, age, and residence were recruited between July 1991 and December 1994. A structured questionnaire inquiring complete dietary history, socio-demographic characteristics, and other potential confounding factors was used in the personal interview. Unconditional logistic regression analysis was used to estimate multivariate-adjusted odds ratio (OR_adj) with 95% confidence interval (CI) after accounting for known risk factors.

Results

Fresh fish (OR_adj, 0.56; 95% CI, 0.38–0.83 for the highest vs. lowest tertile of intake), green tea (OR_adj, 0.61; 95% CI, 0.40–0.91 for drinking ≥1 times/week vs. never) and coffee (OR_adj, 0.56; 95% CI, 0.37–0.85 for drinking ≥0.5 times/week vs. never) were inversely associated with the NPC risk. No association with NPC risk was observed for the intake of meats, salted fish, fresh vegetables, fruits and milk. Intake of vitamin A from plant sources was associated with a decreased NPC risk (OR_adj, 0.62; 95% CI, 0.41–0.94 for the highest vs. lowest tertile).

Conclusion

The study findings suggest that certain adult dietary patterns might protect against the development of NPC.     

IL-1β stimulates COX-2 dependent PGE₂ synthesis and CGRP release in rat trigeminal ganglia cells

Objective

Pro-inflammatory cytokines like Interleukin-1 beta (IL-1β) have been implicated in the pathophysiology of migraine and inflammatory pain. The trigeminal ganglion and calcitonin gene-related peptide (CGRP) are crucial components in the pathophysiology of primary headaches. 5-HT1B/D receptor agonists, which reduce CGRP release, and cyclooxygenase (COX) inhibitors can abort trigeminally mediated pain. However, the cellular source of COX and the interplay between COX and CGRP within the trigeminal ganglion have not been clearly identified.

Methods and Results

1. We used primary cultured rat trigeminal ganglia cells to assess whether IL-1β can induce the expression of COX-2 and which cells express COX-2. Stimulation with IL-1β caused a dose and time dependent induction of COX-2 but not COX-1 mRNA. Immunohistochemistry revealed expression of COX-2 protein in neuronal and glial cells. 2. Functional significance was demonstrated by prostaglandin E2 (PGE₂) release 4 hours after stimulation with IL-1β, which could be aborted by a selective COX-2 (parecoxib) and a non-selective COX-inhibitor (indomethacin). 3. Induction of CGRP release, indicating functional neuronal activation, was seen 1 hour after PGE₂ and 24 hours after IL-1β stimulation. Immunohistochemistry showed trigeminal neurons as the source of CGRP. IL-1β induced CGRP release was blocked by parecoxib and indomethacin, but the 5-HT1B/D receptor agonist sumatriptan had no effect.

Conclusion

We identified a COX-2 dependent pathway of cytokine induced CGRP release in trigeminal ganglia neurons that is not affected by 5-HT1B/D receptor activation. Activation of neuronal and glial cells in the trigeminal ganglion by IL-β leads to an elevated expression of COX-2 in these cells. Newly synthesized PGE₂ (by COX-2) in turn activates trigeminal neurons to release CGRP. These findings support a glia-neuron interaction in the trigeminal ganglion and demonstrate a sequential link between COX-2 and CGRP. The results could help to explain the mechanism of action of COX-2 inhibitors in migraine.     

Early interleukin-6 and slope of monocyte human leukocyte antigen-DR: a powerful association to predict the development of sepsis after major trauma

Objective

Major trauma is characterized by a pro-inflammatory response, followed by an immunosuppression. Recently, in trauma patients, the lack of recovery of monocyte Human Leukocyte Antigen DR (mHLA-DR, a biomarker of ICU-acquired immunosuppression) between days 1–2 and days 3–4 has been demonstrated to be independently associated with sepsis development. The main objective of this study was to determine whether early measurements of IL-6 (interleukin-6) and IL-10 plasma concentrations (as markers of initial severity) could improve, in association with mHLA-DR recovery, the prediction of sepsis occurrence in severe trauma patients.

Design

Prospective observational study over 24 months in a Trauma ICU at university hospital.

Patients

Trauma patients with an ISS over 25 and age over 18 were included.

Measurements and Main Results

mHLA-DR was assessed by flow cytometry, IL-6 and IL-10 concentrations by ELISA. 100 consecutive severely injured patients were monitored (mean ISS 37±10). 37 patients developed sepsis. IL-6 concentrations and slope of mHLA-DR expression between days 1–2 and days 3–4 were significantly different between septic and non-septic patients. IL-10 was not detectable in most patients. After adjustment for usual clinical confounders, when assessed as a pair, multivariate logistic regression analysis revealed that a slope of mHLA-DR expression (days 3–4/days 1–2)≤1.1 and a IL-6 concentration ≥ 67.1 pg/ml remained highly associated with the development of sepsis (adjusted OR 18.4, 95% CI 4.9; 69.4, p = .00002).

Conclusions

After multivariate regression logistic analysis, when assessed as a pair, a high IL-6 concentration and a persistent mHLA-DR decreased expression were found to be in relation with the development of sepsis with the best predictive value. This study underlines the usefulness of daily monitoring of immune function to identify trauma patients at a high risk of infection.     

Optical and NMR dose response of N-isopropylacrylamide normoxic polymer gel for radiation therapy dosimetry

Background

Application of less toxic normoxic polymer gel of N-isopropyl acrylamide (NIPAM) for radiation therapy has been studied in recent years.

Aim

In the current study the optical and NMR properties of NIPAM were studied for radiation therapy dosimetry application.

Materials and methods

NIPAM normoxic polymer gel was prepared and irradiated by 9 MV photon beam of a medical linac. The optical absorbance was measured using a conventional laboratory spectrophotometer in different wavelengths ranging from 390 to 860 nm. R₂ measurements of NIPAM gels were performed using a 1.5 T scanner and R₂–dose curve was obtained.

Results

Our results showed R₂ dose sensitivity of 0.193 ± 0.01 s⁻¹ Gy⁻¹ for NIPAM gel. Both R₂ and optical absorbance showed a linear relationship with dose from 1.5 to 11 Gy for NIPAM gel dosimeter. Moreover, absorbance–dose response varied considerably with light wavelength and highest sensitivity was seen for the blue part of the spectrum.

Conclusion

Our results showed that both optical and NMR approaches have acceptable sensitivity and accuracy for dose determination with NIPAM gel. However, for optical reading of the gel, utilization of an optimum optical wavelength is recommended.     

Nitrosative and oxidative stresses contribute to post-ischemic liver injury following severe hemorrhagic shock: the role of hypoxemic resuscitation

Purpose

Hemorrhagic shock and resuscitation is frequently associated with liver ischemia-reperfusion injury. The aim of the study was to investigate whether hypoxemic resuscitation attenuates liver injury.

Methods

Anesthetized, mechanically ventilated New Zealand white rabbits were exsanguinated to a mean arterial pressure of 30 mmHg for 60 minutes. Resuscitation under normoxemia (Normox-Res group, n = 16, PaO₂ = 95–105 mmHg) or hypoxemia (Hypox-Res group, n = 15, PaO₂ = 35–40 mmHg) followed, modifying the FiO₂. Animals not subjected to shock constituted the sham group (n = 11, PaO₂ = 95–105 mmHg). Indices of the inflammatory, oxidative and nitrosative response were measured and histopathological and immunohistochemical studies of the liver were performed.

Results

Normox-Res group animals exhibited increased serum alanine aminotransferase, tumor necrosis factor - alpha, interleukin (IL) -1β and IL-6 levels compared with Hypox-Res and sham groups. Reactive oxygen species generation, malondialdehyde formation and myeloperoxidase activity were all elevated in Normox-Res rabbits compared with Hypox-Res and sham groups. Similarly, endothelial NO synthase and inducible NO synthase mRNA expression was up-regulated and nitrotyrosine immunostaining increased in animals resuscitated normoxemically, indicating a more intense nitrosative stress. Hypox-Res animals demonstrated a less prominent histopathologic injury which was similar to sham animals.

Conclusions

Hypoxemic resuscitation prevents liver reperfusion injury through attenuation of the inflammatory response and oxidative and nitrosative stresses.     

Mitigation measures for pandemic influenza in Italy: an individual based model considering different scenarios

Background

Individual-based models can provide the most reliable estimates of the spread of infectious diseases. In the present study, we evaluated the diffusion of pandemic influenza in Italy and the impact of various control measures, coupling a global SEIR model for importation of cases with an individual based model (IBM) describing the Italian epidemic.

Methodology/Principal Findings

We co-located the Italian population (57 million inhabitants) to households, schools and workplaces and we assigned travel destinations to match the 2001 census data. We considered different R₀ values (1.4; 1.7; 2), evaluating the impact of control measures (vaccination, antiviral prophylaxis -AVP-, international air travel restrictions and increased social distancing). The administration of two vaccine doses was considered, assuming that first dose would be administered 1-6 months after the first world case, and different values for vaccine effectiveness (VE). With no interventions, importation would occur 37–77 days after the first world case. Air travel restrictions would delay the importation of the pandemic by 7–37 days. With an R₀ of 1.4 or 1.7, the use of combined measures would reduce clinical attack rates (AR) from 21–31% to 0.3–4%. Assuming an R₀ of 2, the AR would decrease from 38% to 8%, yet only if vaccination were started within 2 months of the first world case, in combination with a 90% reduction in international air traffic, closure of schools/workplaces for 4 weeks and AVP of household and school/work close contacts of clinical cases. Varying VE would not substantially affect the results.

Conclusions

This IBM, which is based on country-specific demographic data, could be suitable for the real-time evaluation of measures to be undertaken in the event of the emergence of a new pandemic influenza virus. All preventive measures considered should be implemented to mitigate the pandemic.     

A prospective study of aspirin use and the risk of gastrointestinal bleeding in men

Background and Aims

Data regarding the influence of dose and duration of aspirin use on risk of gastrointestinal bleeding are conflicting.

Methods

We conducted a prospective cohort study of 32,989 men enrolled in the Health Professionals Follow-up Study (HPFS) in 1994 who provided biennial aspirin data. We estimated relative risk of major gastrointestinal bleeding requiring hospitalization or a blood transfusion.

Results

During 14 years of follow-up, 707 men reported an episode of major gastrointestinal bleeding over 377,231 person-years. After adjusting for risk factors, regular aspirin use (≥2 times/week) had a multivariate relative risk (RR) of gastrointestinal bleeding of 1.32 (95% confidence interval [CI], 1.12–1.55) compared to non-regular use. The association was particularly evident for upper gastrointestinal bleeding (multivariate RR, 1.49; 95% CI, 1.16–1.92). Compared to men who denied any aspirin use, multivariate RRs of upper gastrointestinal bleeding were 1.05 (95% CI 0.71–1.52) for men who used 0.5–1.5 standard tablets/week, 1.31 (95% CI 0.88–1.95) for 2–5 aspirin/week, 1.63 (95% CI, 1.15–2.32) for 6–14 aspirin/week and 2.40 (95% CI, 1.10–5.22) for >14 aspirin/week (P_trend<0.001). The relative risk also appeared to be dose-dependent among short-term users <5 years; P_trend<.001) and long-term users (≥5 years; P_trend = 0.015). In contrast, after controlling for dose, increasing duration of use did not appear to be associated with risk (P_trend = 0.749).

Conclusions

Regular aspirin use increases the risk of gastrointestinal bleeding, especially from the upper tract. However, risk of bleeding appears to be more strongly related to dose than to duration of use. Risk of bleeding should be minimized by using the lowest effective dose among short-term and long-term aspirin users.