Efficacy of an internet-based behavioral weight loss program for overweight adolescent African-American girls

OBJECTIVE

This randomized controlled trial tested the efficacy of an internet-based lifestyle behavior modification program for weight management in African-American girls.

DESIGN

African-American girls were randomly assigned to an interactive behavioral internet program or an internet health education program, the control condition. The behavioral intervention included internet counseling and was highly interactive. The control intervention was a passive (non-interactive) educational program. Parents were also participants in the study. Participants in both treatment groups met in face-to-face sessions on four occasions over the first 12 weeks of a 6-month intervention.

SUBJECTS

The study enrolled 57 African-American adolescent girls (ages 11 to 15 years) who were overweight or obese and had at least one biological parent who was obese [body mass index (BMI) >30 kg/m2]. Of the 57 participants, 50 (88%) completed the 6-month trial.

MEASUREMENTS

Outcome data, including BMI, body weight, body composition, dietary intake, and weight loss behaviors were collected at baseline and 6-months later. A computer server tracked utilization of the websites. Participation in the program was measured by number of "hits" on the website.

RESULTS

Compared to the control condition, adolescents in the behavioral treatment lost more body fat (group difference =1.6% body fat) and parents lost significantly more body weight (group difference =2.1 kg). Utilization of the behavioral website by adolescents and parents was associated with positive outcome. Dietary fat intake was lowered for adolescents and parents in the behavioral treatment group.

CONCLUSION

An internet-based behavioral intervention was superior to internet-based health education and yielded decreased body fat for adolescent girls and decreased body weight for parents.

Clinical utility of viral load measurements in individuals with chronic hepatitis C infection on antiviral therapy

Both absolute viral load and log decline in viral load from baseline were found clinically useful in predicting sustained virological response and lack of sustained virological response (non-sustained virological response, NSVR) to treatment. We assessed the clinical utility of hepatitis C virus (HCV) RNA quantitation and changes in viral load using the VERSANT HCV RNA 3.0 Assay (bDNA) in 351 HCV-infected individuals treated with interferon plus ribavirin. We show that viral load decision thresholds provided negative predictive values (NPVs) of >95% at week 4 using a 100 000 IU/mL cut-off and at weeks 8 and 12 using 10 000 IU/mL cut-offs. A 2-log decline from baseline provided NPVs >95% at weeks 8 and 12. Combinations of absolute viral loads and changes in viral load from baseline did not enhance the performance of the decision rules for predicting NSVR. The positive predictive values (PPVs) at weeks 8 and 12 were 59.1 and 67.3%. This study highlights the critical importance of viral quantitation in gauging therapeutic response in patients with chronic HCV infection on antiviral therapy. Early changes in viral load, measured as absolute viral loads or change in viral load from baseline, are highly predictive of NSVR at 8 and 12 weeks. PPVs are modest but these data may provide encouragement to patients who are in the early phases of treatment when side effects are frequent. Additionally, we demonstrated the need for cautious interpretation of stopping rules when the values are at or near the decision thresholds.

Water Resources Management and the Energy Industry in Alberta, Canada

Abstract

The challenges associated with managing Alberta's water resources are increasing as a result of population growth, agricultural expansion, and industrial development, including the energy industry. This challenge is being addressed through creative initiatives at the provincial and local levels, and reflects the involvement of many stakeholders. The road ahead will involve: continued development of stakeholder-driven water management initiatives; ongoing refinement and clarification of water management objectives; and, an improved understanding of the aquifer system, including its connection to surface water. Water is an essential resource for Alberta's energy industries, which produce 70% of Canada's crude oil and 80% of its natural gas, and these industries have done much to minimize the use of water. Nevertheless, the challenge to the energy sector will be continued development of water conservation and water quality management technologies.

Introduction

Energy industries are of significant importance to Albertans. Alberta is rich in natural gas, oil sands, and conventional oil, and produces 70% of Canada's crude oil and 80% of its natural gas(1). Energy-related royalty revenues account for about one-third of total provincial revenue (about $7.7 billion in 2003 - 2004)(2). The mining and oil and gas industries account for more than 17% of provincial GDP. For comparison, crop and animal production contributes 1.6% to provincial GDP(3).

Conventional oil, natural gas, and coal are found in many parts of the province, and heavy oil and oil sands are found in the north and east (Figure 1). The energy industry requires water for many aspects of production, in particular for enhanced oil recovery (oilfield injection), in situ heavy oil recovery, oil sands mining, and dewatering for coal bed methane.

Alberta is also experiencing high population and economic growth in other sectors, also leading to increasing demands on water resources, especially in the central and southern parts of the province. Currently, there is a moratorium on surface water withdrawals for some streams in Southern Alberta. In contrast, surface water is most available in the northern part of the province. Ground water availability is less known across the province, and this lack of information creates uncertainty in the role of ground water for supply and ecosystem health. The province, therefore, faces numerous and unique water management challenges related to the energy sector and to growing demand, fluctuations and limitations in supply, the need to maintain healthy aquatic ecosystems, and commitments embedded in downstream water agreements with adjacent neighbours(4).

This paper describes the issues and challenges for water management in Alberta related to the energy sector in particular. It also highlights the current policy and management strategies developed by stakeholders to address these challenges in a practical and often creative manner, to ensure sustainability of water resources while satisfying future growth opportunities.

Alberta's Water Resources

Alberta is one of Canada's western prairie provinces and covers 661,185 km2. The prairies are one of the driest regions of Canada. Alberta has a diversity of hydrological and hydrogeological settings that are characterized by varied physiography, geology, and climate.

Macrophage receptors and immune recognition

Macrophages express a broad range of plasma membrane receptors that mediate their interactions with natural and altered-self components of the host as well as a range of microorganisms. Recognition is followed by surface changes, uptake, signaling, and altered gene expression, contributing to homeostasis, host defense, innate effector mechanisms, and the induction of acquired immunity. This review covers recent studies of selected families of structurally defined molecules, studies that have improved understanding of ligand discrimination in the absence of opsonins and differential responses by macrophages and related myeloid cells.

Influence of inter-annual variations in climatic factors on fecal coliform levels in Mississippi Sound

Information on the effects of inter-annual variations in climatic factors on fecal coliform levels in coastal waters is scarce. We used 11 years (1990-2001) of rainfall, water temperature, Pearl River stage and salinity data to assess the effects of the 1991-1992 and 1997-1998 El Nino events on fecal coliform levels in Mississippi Sound. El Nino-Southern Oscillation had major effects on Pearl River stage and water quality in the Sound. The geometric mean fecal coliform number differed among years (P = 0.0001), being highest during 1991-1992 El Nino years (14.22 MPN per 100 ml) and lowest during 1999-2000 La Nina years (<1.8 MPN per 100 ml). Mean salinity varied among years (P = 0.0001) from 9 ppt (1991-1992) to 21 ppt (1999-2000). Mean water temperature was lowest in 1997-1998 (14.5 degrees C) and highest in 1998-2000 (19.4 degrees C). Pearl River stage differed among years (P = 0.0001), ranging from 1.96 m (1999-2000) to 3.57 m (1997-1998). Inverse relationships were observed between fecal coliform levels and salinity (r(2) = 0.74; P = 0.001) and water temperature (r(2) = 0.69; P=0.001), whereas positive relationships were obtained with total rainfall (r(2) = 0.52; P = 0.013) and Pearl River stage (r(2) = 0.90; P = 0.0001). These relationships are useful for evaluating the potential effects of climate change on water quality and classification of shellfish growing waters in order to protect humans from consuming contaminated shellfish in shallow river-influenced estuaries.

Exposure-response relations for work related respiratory symptoms and sensitisation in a cohort exposed to alpha-amylase

AIMS

To explore relations between exposure to fungal alpha-amylase and the risk of new work related respiratory symptoms or sensitisation.

METHODS

A prospective cohort study among 300 bakers and millers was followed up for a maximum of seven years. Exposure to alpha-amylase was estimated by air measurements and questionnaires and classified into three categories. Symptoms were recorded with a self-administered questionnaire and skin sensitisation assessed using skin prick test (SPT).

RESULTS

There were 36 new cases of chest symptoms, 86 of eyes/nose symptoms, and 24 of a positive SPT to alpha-amylase. There were exposure-response relations for chest and eyes/nose symptoms and for sensitisation, and a significantly increased prevalence ratio for chest symptoms in the highest exposure category.

CONCLUSION

A reduction in alpha-amylase exposure is likely to reduce the risk for respiratory morbidity in bakery workers.

Application of combined liver-intestinal transplantation as a staged procedure

Liver-intestinal transplantation is a complex surgical procedure that historically has required prolonged operative periods. This report is the first series where liver-intestinal transplantation was performed as a staged procedure. Specifically, allograft reperfusion was followed by resuscitation and stabilization in an intensive care unit before completion of the transplant procedure. Triage of recipients to the intensive care unit following allograft reperfusion was determined at the time of operation and was based upon the clinical condition of the recipient including hemodynamic stability, evidence of coagulopathy, and assessment of early liver function. Medical stabilization was followed by completion of the transplant procedure and definitive abdominal closure within 72 hours. The application of combined liver-intestinal transplantation as a staged procedure demonstrated no effect upon early graft function, incidence of complications, or ability to perform a definitive abdominal closure.

PTX3 function as an opsonin for the dectin-1-dependent internalization of zymosan by macrophages

Pentraxin 3 (PTX3) is a tumor necrosis factor and interleukin-1beta-stimulated gene that encodes a long PTX with proinflammatory activity. Here, we show that peritoneal macrophages derived from PTX3 transgenic (Tg) mice express higher levels of PTX3 mRNA than macrophages from wild-type (WT) mice, at basal level as well as upon stimulation with zymosan (Zy). Macrophages from Tg mice also showed improved opsonin-independent phagocytosis of Zy particles and the yeast form of the fungus Paracoccidioides brasiliensis. In the case of P. brasiliensis, an enhanced microbicidal activity accompanied by higher production of nitric oxide was also observed in macrophages from Tg mice. Using fluorescein-activated cell sorter analysis and reverse transcriptase-polymerase chain reaction, we demonstrated that basal level of Toll-like receptor-6 and Zy-induced dectin-1 expression was slightly but consistently higher in macrophages from Tg mice than in macrophages from WT mice. Recombinant (r)PTX3 protein binds to Zy particles as well as to yeast cells of P. brasiliensis and addition of rPTX3, to a culture of WT-derived macrophages containing Zy leads to an increase in the phagocytic index, which parallels that of Tg-derived macrophages, demonstrating the opsonin-like activity of PTX3. It is important that blockade of dectin-1 receptor inhibited the phagocytosis of Zy particles by WT and PTX3 Tg macrophages, pointing out the relevant role of dectin-1 as the main receptor involved in Zy uptake. Our results provide evidence for a role of PTX3 as an important component of the innate-immune response and as part of the host mechanisms that control fungal recognition and phagocytosis.

Prevention of laboratory animal allergy

BACKGROUND

Laboratory animal allergy (or LAA) is an important threat to the occupational health of those who work with rats, mice and other species.

AIM

This review examines the risk factors for LAA and the effectiveness of control measures.

METHODS

A literature review was performed.

RESULTS

An extensive literature was identified regarding LAA and the use of control measures. The contribution that these measures can make to the overall effectiveness of an occupational health and safety programme is discussed in the context of the literature currently available.

CONCLUSION

The incidence of this disease can be reduced by effective, integrated health risk management, with the conscientious use of engineering, procedural and personal control measures.

Cloning of intestinal phospholipase A2 from intestinal epithelial RNA by differential display PCR

Differential display polymerase chain reaction (DD-PCR) is a powerful technique for comparing gene expression between cell types, or between stages of development or differentiation. Differentially expressed genes may be cloned and analysed further. Here we extend the use of DD-PCR to analyse differences in gene expression between two complex epithelia: that of the small intestine and of the large intestine. The aim of this study was to identify genes expressed preferentially in Paneth cells. Paneth cells are secretory epithelial cells putatively involved in host defense and regulation of crypt cell proliferation and are found at the base of the small intestinal crypts adjacent to the stem cell zone. Of 34 clones that were analysed, partial sequencing identified two clones related to known Paneth cell products: a homologue of secretory phospholipase A2 (clone B1) and a homologue of a neutrophil defensin (clone C5). B1 was strongly expressed in Paneth cells, as demonstrated by in-situ hybridization. B1 was also expressed at a lower level in the large intestinal epithelium. A full length B1 cDNA clone was isolated and sequenced, and shown to be highly homologous to type II secretory phospholipase A2 genes, and almost identical to the enhancing factor gene and the putative gene for the MOM-1 locus. B1 expression is limited to the intestinal tract, and we propose that it be designated intestinal phospholipase A2, or i-PLA2. The method we describe is well suited to the rapid identification of genes expressed exclusively or predominantly in Paneth cells.

Active immunization against nicotine prevents reinstatement of nicotine-seeking behavior in rats

BACKGROUND

The presently available pharmaceutical aids in smoking cessation possess a rather limited effectiveness. Therefore, we have synthesized a series of immunoconjugates that stimulate the induction of antibodies which may bind nicotine in the blood, thereby preventing it from passing the blood-brain barrier. Thus, the reinforcing action of nicotine in the brain, which is the driving force in tobacco smoking, should be abolished.

OBJECTIVE

The present study was undertaken to test this notion in a long-term relapse model in rats, measuring the reinstatement of nicotine-seeking behavior, following active immunization with IP18-KLH, one of our immunoconjugates.

METHODS

Male Wistar rats were immunized with a nicotine-KLH conjugate (nicotine immunogen) and Freund's adjuvant after having been trained to meet the criteria of stable nicotine self-administration on a fixed ratio (FR3) schedule. The rats were subsequently extinguished from nicotine self-administration behavior and finally, as extinction was completed, they were exposed to small, priming doses of nicotine, which previously have been shown to reinstate the nicotine-seeking behavior. The antibody titers were measured by ELISA.

RESULTS

It was found that rats with high titers (>1:10,000) of antibodies against nicotine, in contrast to those with low/no nicotine selective antibodies, do not reinstate nicotine self-administration behavior when they are exposed to nicotine.

CONCLUSIONS

Our findings indicate that active immunization against nicotine may effectively abolish the reinforcing action of nicotine in brain, an effect which is critical for relapse in nicotine dependence. These data suggest the potential utility of active immunization in smoking cessation programs.

Active immunization against nicotine suppresses nicotine-induced dopamine release in the rat nucleus accumbens shell

BACKGROUND

Tobacco smoking is the largest preventable cause of morbidity and premature mortality in the world. Although its medical consequences are well documented, 20-50% of the population even in developed countries remain tobacco smokers. The drugs presently used in smoking cessation have limited efficiency and, therefore, there is a need for alternative and improved treatments. One novel approach in this regard may be provided by immunization against nicotine.

OBJECTIVE

The present study in male Wistar rats investigated if active immunization with a novel nicotine immunogen, IP18-KLH, may generate nicotine-selective antibodies and, furthermore, whether this treatment might prevent nicotine from exerting its stimulating effect on the mesolimbic, dopaminergic reward system in the brain.

METHODS

Enzyme-linked immunosorbent assay (ELISA) was used to determine the titer of nicotine antibodies in plasma after immunization with IP18-KLH in Freund's adjuvant. Competitive ELISA was used to assess the selectivity of the antibodies. Finally, we used in vivo voltammetry to investigate whether active immunization with IP18-KLH could prevent nicotine-induced dopamine release in the shell of nucleus accumbens (NAC(shell)).

RESULTS

The present study shows that active immunization with IP18-KLH generates antibodies that are highly selective for nicotine. Furthermore, immunization with IP18-KLH prevented the nicotine-induced increase in dopamine release in the NAC(shell), a biochemical correlate to the rewarding properties of nicotine.

CONCLUSIONS

Active immunization with IP18-KLH prevents a central effect of nicotine that is considered critical for the induction of nicotine dependence. Consequently, active immunization may provide long-term protection against initiation of tobacco dependence, an effect that may prove particularly advantageous in relapse prevention.

Mesenchymal stem cells combined with biphasic calcium phosphate ceramics promote bone regeneration

The reconstruction and repair of large bone defects, resulting from trauma, cancer or metabolic disorders, is a major clinical challenge in orthopaedics. Clinically available biological and synthetic grafts have clear limitations that necessitate the development of new graft materials and/or strategies. Human mesenchymal stem cells (MSCs), obtained from the adult bone marrow, are multipotent cells capable of differentiating into various mesenchymal tissues. Of particular interest is the ability of these cells to differentiate into osteoblasts, or bone-forming cells. At Osiris, we have extensively characterized MSCs and have demonstrated MSCs can induce bone repair when implanted in vivo in combination with a biphasic calcium phosphate, specifically hydroxyapatite/tricalcium phosphate. This article reviews previous and current studies utilizing mesenchymal stem cells and biphasic calcium phosphates in bone repair.

Exposure-response relations among laboratory animal workers exposed to rats

AIM

To explore exposure-response relations in a cohort of laboratory animal workers.

METHODS

Exposure-response modelling was carried out in a cohort of 342 laboratory animal workers. Three exposure indices, divided into different exposure categories, were used in the analyses: intensity of exposure to rat urinary aeroallergen (RUA, the main allergen workers were exposed to), weekly duration of exposure to rats, and the product of the intensity and weekly duration of exposure. Outcomes studied were work related chest, eyes and nose, and skin symptoms that had started after employment at the sites, specific sensitisation, and a combination of symptoms and sensitisation. Cox proportional hazard modelling was used to explore exposure-response relations. Smoking, atopic status, age, and gender were taken into account.

RESULTS

We observed the clearest exposure-response relations for the intensity of exposure to RUA and the various endpoints. No clear exposure-response relations were observed for the weekly duration of exposure or the product of the intensity and weekly duration of exposure. The strongest and clearest exposure-response relations for symptoms were observed among rat sensitised workers, while the non-sensitised workers only showed small increased risks of developing symptoms without clear exposure-response relations. Sensitised workers were almost four times more likely to go on to develop chest symptoms compared to non-sensitised workers.

Induction of proinflammatory cytokines in human macrophages by influenza A (H5N1) viruses: a mechanism for the unusual severity of human disease?

BACKGROUND

In 1997, the first documented instance of human respiratory disease and death associated with a purely avian H5N1 influenza virus resulted in an overall case-fatality rate of 33%. The biological basis for the severity of human H5N1 disease has remained unclear. We tested the hypothesis that virus-induced cytokine dysregulation has a role.

METHODS

We used cDNA arrays and quantitative RT-PCR to compare the profile of cytokine gene expression induced by viruses A/HK/486/97 and A/HK/483/97 (both H5N1/97) with that of human H3N2 and H1N1 viruses in human primary monocyte-derived macrophages in vitro. Secretion of tumour necrosis factor alpha (TNF alpha) from macrophages infected with the viruses was compared by ELISA. By use of naturally occurring viral reassortants and recombinant viruses generated by reverse genetic techniques, we investigated the viral genes associated with the TNF-alpha response.

FINDINGS

The H5N1/97 viruses induced much higher gene transcription of proinflammatory cytokines than did H3N2 or H1N1 viruses, particularly TNF alpha and interferon beta. The concentration of TNF-alpha protein in culture supernatants of macrophages infected with these viruses was similar to that induced by stimulation with Escherichia coli lipopolysaccharide. The non-structural (NS) gene-segment of H5N1/97 viruses contributed to the increase in TNF alpha induced by the virus.

INTERPRETATION

The H5N1/97 viruses are potent inducers of proinflammatory cytokines in macrophages, the most notable being TNF alpha. This characteristic may contribute to the unusual severity of human H5N1 disease.

Evidence that Very Slow Wallerian Degeneration in C57BL/Ola Mice is an Intrinsic Property of the Peripheral Nerve

We have described a mutant mouse, C57BL/Ola, in which Wallerian degeneration following peripheral nerve transection is very slow. Our previous results suggested that recruited monocytes play a role in rapid Wallerian degeneration. The nature of the mutation in C57BL/Ola mice is not known and we have investigated whether the defect is intrinsic to the nerve or due to a defect in the circulating monocytes. We have made chimaeric mice in which bone marrow from histocompatible mice, with rapidly degenerating nerves and normal monocyte recruitment, was used to reconstitute irradiated C57BL/Ola mice and vice-versa. A substantial degree of donor repopulation of the hosts was confirmed by measures of the levels of glucose-phosphate isomerase alloenzymes in blood and tissue samples from the two different strains. The rate of degeneration of the transected sciatic nerve was found to be host-dependent, providing evidence that the mutation affects cell populations intrinsic to the nerve and not the circulating monocytes. We provide additional evidence that the peripheral nerves of C57BL/Ola mice are different from those of other mice as they degenerate at a slower rate in vitro.

Evidence that the Rate of Wallerian Degeneration is Controlled by a Single Autosomal Dominant Gene

In a substrain of C57BL mice, C57BL/Ola, Wallerian degeneration in the distal segment of the severed sciatic nerve is extremely slow when compared to other mice. Despite this very slow degeneration in the distal segment regeneration of the motor nerves is not impaired. From suitable genetic outcrosses and backcrosses, the authors provide evidence that the rate of Wallerian degeneration in this strain is controlled by a single autosomal gene product. The authors have also shown that the rate of degeneration, in C57BL/Ola mice, is influenced by the environment in which the animals were bred and housed. Wallerian degeneration in the sciatic nerves of mice raised in isolators is slower than in those raised in a conventional animal house. This strain of mouse may prove to be of value in the understanding of nerve degeneration and regeneration.