Transport characteristics of nanoscale functional zerovalent iron/silica composites for in situ remediation of trichloroethylene

Effective in situ remediation of groundwater requires the successful delivery of reactive iron particles through soil. In this paper we report the transport characteristics of nanoscale zerovalent iron entrapped in porous silica particles and prepared through an aerosol-assisted process. The entrapment of iron nanoparticles into the silica matrix prevents their aggregation while maintaining the particles' reactivity. Furthermore, the silica particles are functionalized with alkyl groups and are extremely efficient in adsorbing dissolved trichloroethylene (TCE). Because of synthesis through the aerosol route, the particles are of the optimal size range (0.1-1 microm) for mobility through sediments. Column and capillary transport experiments confirm that the particles move far more effectivelythrough model soils than commercially available uncoated nanoscale reactive iron particles. Microcapillary experiments indicate that the particles partition to the interface of TCE droplets, further enhancing their potential for dense non-aqueous-phase liquid source-zone remediation.

AFP, PIVKAII, GP3, SCCA-1 and follisatin as surveillance biomarkers for hepatocellular cancer in non-alcoholic and alcoholic fatty liver disease

Background

The incidence and mortality of hepatocellular cancer (HCC) complicating alcoholic and non-alcoholic fatty liver diseases (ALD and NAFLD) is rising in western societies. Despite knowing the at risk populations for HCC development, the lack of sensitive and specific means of surveillance hampers disease detection at curable stages. The most widely used serum HCC marker is alpha-fetoprotein (AFP), while PIVKA-II, glypican-3 (GP3) and Squamous Cell Carcinoma Antigen -1 (SCCA-1) have been proposed as new biomarkers. Assessment of these HCC biomarkers has largely been performed in patients with viral hepatitis. We conducted a cross sectional study assessing the value of these serum proteins, as well a novel candidate biomarker -follistatin – in patients with HCC arising on a background of ALD or NAFLD.

Methods

Pre-treatment serum samples from 50 patients with HCC arising on a background of ALD (n = 31) or NAFLD (n = 19) were assessed by specific ELISA assay for PIVKAII, Glypican-3, SCCA-1 and Follistatin. Results were compared and contrasted with a control patient group with biopsy proven steatohepatitis-related cirrhosis (n = 41). The diagnostic accuracy of each of the candidate biomarkers was evaluated using receiver operating characteristic (ROC) curve analysis, reporting the area under the curve (AUC) and its 95% confidence interval (CI). Performance was compared to that of the established biomarker, AFP.

Results

Serum levels of all proteins were assessed by specific ELISA assays. GP3, SCCA-1 and follistatin had no HCC surveillance benefit in these patients. AFP and PIVKAII were superior to the other markers, particularly in combination.

Conclusion

We conclude that while novel means of surveillance are urgently required, the combination of AFP and PIVKAII for HCC is an improvement on AFP alone in ALD/NAFLD patients. Furthermore, our data in this homogenous subset of patients- particularly that confirming no role for SCCA-1 – suggests that the choice of optimal biomarkers for HCC surveillance may be determined by the aetiology of underlying chronic liver disease.

Reactivity characteristics of nanoscale zerovalent iron--silica composites for trichloroethylene remediation

Spherical silica particles containing nanoscale zerovalent iron were synthesized through an aerosol-assisted process. These particles are effective for groundwater remediation, with the environmentally benign silica particles serving as effective carriers for nanoiron transport. Incorporation of iron into porous sub-micrometer silica particles protects ferromagnetic iron nanoparticles from aggregation and may increase their subsurface mobility. Additionally, the presence of surface silanol groups on silica particles allows control of surface properties via silanol modification using organic functional groups. Aerosolized silica particles with functional alkyl moieties, such as ethyl groups on the surface, clearly adsorb solubilized trichloroethylene (TCE) in water. These materials may therefore act as adsorbents which have coupled reactivity characteristics. The nanoscale iron/silica composite particles with controlled surface properties have the potential to be efficiently applied for in situ source depletion and in the design of permeable reactive barriers.

Clinical outcome in patients from a single region who were dependent on parenteral nutrition for 28 days or more

BACKGROUND

The frequency and outcome of intestinal failure (IF) in children are not well defined in the UK. Long-term parenteral nutrition (PN) is an effective intervention, with intestine transplantation offering the possibility of survival should life-threatening complications arise in those with long-term dependency. The ideal model for service provision is a subject of debate.

AIMS

We aimed to identify all new cases of IF (defined as PN dependency > or =28 days) in West Yorkshire over a two-year period to determine the rate of serious complications, establish the outcome after two years and clarify the role of specialist referral.

METHOD

Pharmacists in all the West Yorkshire paediatric units were contacted to establish the number of children with IF during 2001-2002. Underlying diagnosis, complications and outcome at two years were obtained by case-note review for 93 of the 96 children identified.

RESULTS

IF patients were exclusively managed in one or other of the three large teaching hospitals. At the two-year follow-up, six (6.4%) children had died (one while listed for a small bowel transplantation), but 85 (91%) had established full enteral feeding and were well. Two remained PN dependent and were assessed in the supra-regional intestinal transplantation unit (Birmingham); in neither case was small bowel transplantation thought to be appropriate. The most common complications were central venous catheter sepsis (69% of patients) and cholestasis (59%).

CONCLUSIONS

This study shows that a favourable outcome for IF can be achieved in a regional centre with appropriate multidisciplinary support. A single UK supra-regional unit undertaking small bowel transplantation is probably adequate for assessment of the most complex patients, although this should remain under review.

Non-alcoholic fatty liver disease is independently associated with an increased prevalence of chronic kidney disease and proliferative/laser-treated retinopathy in type 2 diabetic patients

AIMS/HYPOTHESIS

Non-alcoholic fatty liver disease (NAFLD) is associated with an increased risk of cardiovascular disease in type 2 diabetes. Currently, there is a lack of information on associations between NAFLD and microvascular complications of diabetes. We assessed the associations between NAFLD and both chronic kidney disease (CKD) and retinopathy in a large cohort of type 2 diabetic individuals using a cross-sectional design.

METHODS

Prevalence rates of retinopathy (by ophthalmoscopy) and CKD (defined as overt proteinuria and/or estimated GFR <or= 60 ml min(-1) 1.73 m(-2)) were assessed in 2,103 type 2 diabetic individuals who were free of diagnosed cardiovascular disease and viral hepatitis. NAFLD was ascertained by patient history, blood sampling and liver ultrasound.

RESULTS

NAFLD patients had higher (p<0.001) age- and sex-adjusted prevalence rates of both non-proliferative (39 vs 34%) and proliferative/laser-treated retinopathy (11 vs 5%), and CKD (15 vs 9%) than counterparts without NAFLD. In logistic regression analysis, NAFLD was associated with increased rates of CKD (odds ratio 1.87; 95% CI 1.3-4.1, p=0.020) and proliferative/laser-treated retinopathy (odds ratio 1.75; 1.1-3.7, p=0.031) independently of age, sex, BMI, waist circumference, hypertension, diabetes duration, HbA(1c), lipids, smoking status and medications use.

CONCLUSIONS/INTERPRETATION

Our findings suggest that NAFLD is associated with an increased prevalence of CKD and proliferative/laser-treated retinopathy in type 2 diabetic individuals independently of numerous baseline confounding factors. Further studies are required to confirm the reproducibility of these results and to evaluate whether NAFLD contributes to the development or progression of CKD and retinopathy.

Angiogenesis in two animal models of osteoarthritis

OBJECTIVE

We have previously described angiogenesis at the osteochondral junction and in synovium of knees from patients with osteoarthritis (OA), but little is known about how closely animal models of OA resemble human disease with respect to vascular growth. This study aimed to characterise two animal models of knee OA with particular respect to osteochondral and synovial angiogenesis.

METHOD

We examined the spontaneous Dunkin-Hartley (DH) guinea pig and medial meniscal transection (MNX) rat models of OA. Vessels at the osteochondral junction and in the synovium were identified by lectin immunohistochemistry and quantified by computer-assisted image analysis. Disease severity was assessed using a scoring system.

RESULTS

Blood vessels crossed the osteochondral junction in juvenile rats and guinea pigs, with higher densities in the lateral than medial tibial plateau, the number decreasing with maturation in the absence of other OA changes. In the rat model, increased vascular density was observed both at the osteochondral junction and in the synovium, whilst osteochondral vascularity in control rats decreased with maturation, OA rats showed a persistence of blood vessels at the osteochondral junction. In rat synovium, blood vessel fractional area was increased in the hypertrophied synovium 14 days after surgery, then decreased to control levels by day 28. Significant differences in vascularity were not observed between affected (medial) and spared (lateral) compartments of guinea pig knees.

CONCLUSION

The rat meniscal transection model of OA reproducibly displays both osteochondral and synovial angiogenesis comparable to our previous observations in human knee OA. DH guinea pigs, by contrast, display low vascularity throughout their protracted course of OA development. Changes in vascularisation occur early during the development of OA in the rat, and may contribute to the pathogenesis of OA.

Full neurological recovery from profound (18.0 degrees C) acute accidental hypothermia: successful resuscitation using active invasive rewarming techniques

The case of a 17-year-old girl brought into the emergency department (ED) having been found in a field semi-clad and overtly hypothermic is reported. A weak carotid pulse, agonal breathing and fixed dilated pupils were noted. On arrival in the ED she was in asystolic cardiopulmonary arrest. Initial core body temperature was 18 degrees C. After 4 h of closed cardiopulmonary resuscitation and rewarming using a haemofiltration circuit, she made a full recovery with no adverse neurological sequelae. In this case report, the importance of prolonged resuscitation in cardiopulmonary arrest secondary to acute severe environmental hypothermia and the successful use of a haemofiltration circuit to deliver active core rewarming are highlighted.

Differences and similarities in early atherosclerosis between patients with non-alcoholic steatohepatitis and chronic hepatitis B and C

BACKGROUND/AIMS

To compare carotid intima-media thickness (IMT) - an index of early atherosclerosis - among patients with non-alcoholic steatohepatitis (NASH), patients with chronic hepatitis B (HBV) or C (HCV) and control subjects.

METHODS

We studied 60 consecutive patients with biopsy-proven NASH, 60 patients with HCV, 35 patients with HBV, and 60 healthy controls who were comparable for age and sex. Common carotid IMT was measured with ultrasonography in all participants by a single operator blinded to subjects' characteristics.

RESULTS

Carotid IMT measurements were markedly different among the groups; the lowest values were in controls, intermediate in patients with HBV or HCV, and highest in those with NASH (0.84+/-0.1 vs. 0.97+/-0.1 vs. 1.09+/-0.2 vs. 1.23+/-0.2mm, respectively; p<0.001). The marked differences in carotid IMT that were observed among the groups were little affected by adjustment for age, sex, body mass index, smoking, LDL cholesterol, insulin resistance (by homeostasis model assessment) and components of the Adult Treatment Panel III-defined metabolic syndrome. Concordantly, in logistic regression analysis, NASH, HBV and HCV predicted carotid IMT independent of potential confounders.

CONCLUSIONS

These data suggest that NASH, HCV and HBV are strongly associated with early atherosclerosis independent of classical risk factors, insulin resistance and metabolic syndrome components.

Prevalence of nonalcoholic fatty liver disease and its association with cardiovascular disease among type 2 diabetic patients

OBJECTIVE

To determine the prevalence of nonalcoholic fatty liver disease (NAFLD) in type 2 diabetic population and to compare the prevalence of cardiovascular disease (CVD) and its risk factors between people with and without NAFLD.

RESEARCH DESIGN AND METHODS

The entire sample of type 2 diabetic outpatients (n = 2,839) who regularly attended our clinic was screened. Main outcome measures were NAFLD (by patient history and liver ultrasound) and manifest CVD (by patient history, review of patient records, electrocardiogram, and echo-Doppler scanning of carotid and lower limb arteries).

RESULTS

The unadjusted prevalence of NAFLD was 69.5% among participants, and NAFLD was the most common cause (81.5%) of hepatic steatosis on ultrasound examination. The prevalence of NAFLD increased with age (65.4% among participants aged 40-59 years and 74.6% among those aged > or = 60 years; P < 0.001) and the age-adjusted prevalence of NAFLD was 71.1% in men and 68% in women. NAFLD patients had remarkably (P < 0.001) higher age and sex-adjusted prevalences of coronary (26.6 vs. 18.3%), cerebrovascular (20.0 vs. 13.3%), and peripheral (15.4 vs. 10.0%) vascular disease than their counterparts without NAFLD. In logistic regression analysis, NAFLD was associated with prevalent CVD independent of classical risk factors, glycemic control, medications, and metabolic syndrome features.

CONCLUSIONS

NAFLD is extremely common in people with type 2 diabetes and is associated with a higher prevalence of CVD. Follow-up studies are needed to determine whether NAFLD predicts the development and progression of CVD.

Self reported risk behaviour among injecting drug users: Self versus assisted questionnaire completion

The current study aimed to compare self-reported injecting and sexual risk behaviour among Needle and Syringe Program (NSP) attendees who self-completed a questionnaire to that of those who received assistance in completing the questionnaire. Information on demographic, injecting and sexual risk behaviour was collected via a self-completed questionnaire for an annual cross-sectional survey of injecting drug users (IDUs) recruited from sentinel NSPs around Australia. Assistance was provided when necessary and recorded. Of 2,035 participants, 1,452 (71%) reported completing the questionnaire without assistance. Being male and nominating a language other than English spoken at home was independently associated with receiving assistance with questionnaire completion. Participants who reported heroin as the drug last injected were also more likely to receive assistance. Multivariate analyses revealed those who received assistance with questionnaire completion were less likely to report re-using a syringe after someone else and less likely to report sex work in the past month. The current findings suggest self-completion of risk behaviour questionnaires should be considered as an alternative to interviewer administered questionnaires to maximise accuracy of self-reports.

Carnitine transporter defect: diagnosis in asymptomatic adult women following analysis of acylcarnitines in their newborn infants

Carnitine transporter defect (CTD) is an autosomal recessive disorder characterized by episodes of non-ketotic hypoglycaemia, hyperammonaemia and liver disease, or by the development of cardiomyopathy, both of which occur in infancy and childhood. Blood carnitine concentrations are extremely low. The diagnosis can be confirmed by finding abnormal fat oxidation and carnitine uptake in skin fibroblasts. The condition has not previously been thought to present later in life or to be benign. We report the identification of four women discovered to have CTD as a consequence of finding low carnitine concentrations in the cord blood or newborn samples from their infants. All four mothers had been asymptomatic and none had a cardiomyopathy.

Sustained virological response rates and durability of the response to interferon-based therapies in hepatitis C patients treated in the clinical setting

International controlled trials have demonstrated increasing sustained virological response (SVR) rates to interferon-based therapies in hepatitis-C-treated patients. Response rates of 6-20% in the era of interferon monotherapy are compared with 42-82% with pegylated interferon plus ribavirin. The virological durability of the SVR is unknown and the optimal follow-up for these patients is unclear. The aim of our study was to determine SVR rates and the durability of the response to interferon-based therapies in the clinical setting. From our database of 1540 hepatitis C patients, 344 treatment courses of at least 12 weeks duration were identified, including interferon monotherapy (175 patients), interferon plus ribavirin (96 patients) and peginterferon plus ribavirin (73 patients). Interferon monotherapy was associated with an SVR rate of 5% in 103 genotype 1 patients and 25% in 72 genotype 2/3 patients. Response rates were higher (P < 0.001) with interferon plus ribavirin-41% in 34 genotype 1 patients and 73% in 62 genotype 2/3 patients-and with peginterferon plus ribavirin-47% in 47 genotype 1 patients and 79% in 26 genotype 2/3 patients. Of 147 patients with an SVR, 146 (>99%) remained hepatitis C virus PCR negative during a mean 2.3 years (range 0.3-10.3) of follow-up. In conclusion, with advances in therapies, we are achieving higher response rates in hepatitis C patients treated in the clinical setting. We can now expect an SVR in over half of the treated patients. Importantly, the response is durable and medium and long-term follow-up of these patients are of low yield and largely unnecessary.

Dynamics of oscillator chains from high frequency initial conditions: comparison of phi4 and FPU-beta models

The dynamics of oscillator chains are studied, starting from high frequency initial conditions (h.f.i.c.). In particular, the formation and evolution of chaotic breathers (CB's) of the Klein-Gordon chain with quartic nonlinearity in the Hamiltonian (the phi(4) model) are compared to the results of the previously studied Fermi-Pasta-Ulam (FPU-beta) chain. We find an important difference for h.f.i.c. is that the quartic nonlinearity, which drives the high frequency phenomena, being a self-force on each individual oscillator in the phi(4) model is significantly weaker than the quartic term in the FPU-beta model, which acts between neighboring oscillators that are nearly out-of-phase. The addition of a self-force breaks the translational invariance and adds a parameter. We compare theoretical results, using the envelope approximation to reduce the discrete coupled equations to a partial differential equation for each chain, indicating that various scalings can be used to predict the relative energies at which the basic phenomena of parametric instability, breather formation and coalescence, and ultimately breather decay to energy equipartition, will occur. Detailed numerical results, comparing the two chains, are presented to verify the scalings.