The Use of Low-Calorie Sweeteners by Children: Implications for Weight Management123

The rise in pediatric obesity since the 1970s has been well established in the United States and is becoming a major concern worldwide. As a potential means to help slow the obesity epidemic, low-calorie sweeteners (LCS) have gained attention as dietary tools to assist in adherence to weight loss plans or prevention of excess weight gain. Observational studies tend to show positive correlations between LCS consumption and weight gain in children and adolescents. Although the data are intriguing, these epidemiologic studies do not establish that LCS cause weight gain, because there are likely many lifestyle and genetic differences between children and families who choose to consume LCS and those who do not. Short-term randomized controlled trials have shown LCS use to be BMI neutral or to have modest weight-reducing effects in overweight and obese adolescents. The long-term effects of LCS in children and adolescents are unknown. Some compelling research is currently underway and may provide needed insight into the potential role of LCS in weight management. The paucity of data regarding the effects of LCS use in children and adolescents creates challenges in decision-making for health care providers and parents

SALMON POISONING DISEASE: RESEARCH ON A POTENTIAL METHOD OF LETHAL CONTROL FOR COYOTES

Salmon poisoning disease (SPD) was tested as a potential method of lethal control for coyotes (Canis latrans). Fresh fish containing the agents for SPD was fed to 72 captive adult coyotes. Coho (Oncorhunchus kisutch) and steel head salmon (Salmo gairdneri) from Oregon hatcheries were the principal species of fish used. Coyotes that ate the fish developed observable signs of SPD in a mean of 8 days. The overall rate of mortality was 50%, and death occurred in a mean of 20 days from consuming fish. Coyotes that died from SPD lost a mean of 32% of their body weight during the course of the disease. Other coyotes were fed preserved fish samples or administered oral or intraperitoneal treatments of lymph node matter from coyotes that died from SPD. In light of the relatively low rate of mortality observed, feeding coyotes fish to cause death from SPD appears to be a method of questionable value for controlling numbers of adult coyotes in areas of livestock production unless fish with a highly virulent strain of the SPD agent can be obtained

MOOSE EXPERIMENTALLY INFECTED WITH GIANT LIVER FLUKE (FASCIOLOIDES MAGNA)

Moose (Alces alces) are abnormal, dead-end hosts of the giant liver fluke Fascioloides magna. The worms migrate extensively in moose causing considerable hepatic tissue damage before eventually dying. Few reach sexual maturity and eggs are seldom, if ever, passed in feces. Occurrence of the parasite in moose depends on the presence of a competent definitive host and suitable aquatic snail intermediate hosts of the genus Lymnaea. There is no clinical evidence that F. magna kills moose although the considerable tissue pathology seen in some heavily infected livers is suggestive that they do. In this study, 2 farm-reared calves (2 months old) and a yearling moose (15 months old) were given 50, 110, and 225 F. magna metacercariae, respectively, and observed for 12.5-16 months. No outward signs of disease were observed. The livers of the 2 animals infected as calves were swollen and contained bloody tracks, extensive fibrosis, and capsules; 1 and 11 immature flukes were recovered. The liver of the animal infected as a yearling had 3 large, thick-walled capsules but no flukes. Weight gain and behaviour of all were similar to those of uninfected farm-reared moose. Known aspects of the biology of this parasite and our experimental results suggest that F. magna is unlikely to have been a major factor in the recent moose decline in northwestern Minnesota

MOOSE EXPERIMENTALLY INFECTED WITH GIANT LIVER FLUKE (FASCIOLOIDES MAGNA)

Moose (Alces alces) are abnormal, dead-end hosts of the giant liver fluke Fascioloides magna. The worms migrate extensively in moose causing considerable hepatic tissue damage before eventually dying. Few reach sexual maturity and eggs are seldom, if ever, passed in feces. Occurrence of the parasite in moose depends on the presence of a competent definitive host and suitable aquatic snail intermediate hosts of the genus Lymnaea. There is no clinical evidence that F. magna kills moose although the considerable tissue pathology seen in some heavily infected livers is suggestive that they do. In this study, 2 farm-reared calves (2 months old) and a yearling moose (15 months old) were given 50, 110, and 225 F. magna metacercariae, respectively, and observed for 12.5-16 months. No outward signs of disease were observed. The livers of the 2 animals infected as calves were swollen and contained bloody tracks, extensive fibrosis, and capsules; 1 and 11 immature flukes were recovered. The liver of the animal infected as a yearling had 3 large, thick-walled capsules but no flukes. Weight gain and behaviour of all were similar to those of uninfected farm-reared moose. Known aspects of the biology of this parasite and our experimental results suggest that F. magna is unlikely to have been a major factor in the recent moose decline in northwestern Minnesota

No impact of CMV or EBV seropositivity on the frequency of highly differentiated T-cells in Mexican-American adolescents

Recurring activations of the prevalent latent herpes viruses Cytomegalovirus (CMV) and Epstein-Barr virus (EBV) induces immune cell division leading to the premature terminal differentiation of T-cells. Terminally differentiated T-cells are known to accumulate with age causing a reduction in the naïve T-cell repertoire, which compromises the ability of the adaptive immune system to respond to novel pathogens. Although CMV and EBV seropositivity are hallmarks of the “immune risk profile” and are known to influence the frequency of terminally differentiated T-cells and increase infection risk in adults, it is not known if CMV or EBV impacts on the frequency of these cells in a young subject cohort. PURPOSE: To examine the impact of CMV and EBV seropositivity on the frequency of highly differentiated blood T-cells in Mexican-American adolescents. METHODS: Fasted resting blood samples were obtained from 77 adolescents consisting of both males and females. The presence of antibodies against CMV and EBV was determined in serum by ELISA. Lymphocytes isolated from peripheral blood were assessed for a combination of cell surface markers to determine their stage of differentiation. Monoclonal antibodies and four-color flow cytometry were used to identify senescent (CD27-, CD28-, CD57+), naïve (CCR7+, CD45RA+), memory (CCR7-, CD45RA-) and effector memory (CCD7-, CD45RA+) T-cell markers on pan CD3+ T-cells, CD4+ T-cells and CD8+ T-cells. Differences in T-cell phenotype between the CMV/EBV seropositive and seronegative participants were compared using independent Student t-tests. RESULTS: The prevalence of latent CMV and EBV infection among the subject cohort was 16% and 44% respectively, while 7% of all participants were carrying a latent infection for both. No differences in senescent and memory phenotypes were found between the CMV or EBV seropositive and seronegative groups. CONCLUSION: Despite the known influence of latent CMV and EBV infection on the frequency of senescent T-cells in adults, these preliminary data indicate that CMV and EBV seropositivity has no impact on the frequency of senescent T-cells in adolescents. These data suggest that the increased frequency of terminally differentiated T-cells that are associated with CMV and EBV seropositivity in adults is probably due to long-term infections. Future studies will assess the impact of CMV and EBV seropositivity on immunosenescence in association with other factors known to have an effect on T-cells differentiation, such as BMI and physical activity status

Parasite infections in a social carnivore: Evidence of their fitness consequences and factors modulating infection load

There are substantial individual differences in parasite composition and infection load in wildlife populations. Few studies have investigated the factors shaping this heterogeneity in large wild mammals or the impact of parasite infections on Darwinian fitness, particularly in juveniles. A host's parasite composition and infection load can be shaped by factors that determine contact with infective parasite stages and those that determine the host's resistance to infection, such as abiotic and social environmental factors, and age. Host–parasite interactions and synergies between coinfecting parasites may also be important. We test predictions derived from these different processes to investigate factors shaping infection loads (fecal egg/oocyte load) of two energetically costly gastrointestinal parasites: the hookworm Ancylostoma and the intracellular Cystoisospora, in juvenile spotted hyenas (Crocuta crocuta) in the Serengeti National Park, in Tanzania. We also assess whether parasite infections curtail survival to adulthood and longevity. Ancylostoma and Cystoisospora infection loads declined as the number of adult clan members increased, a result consistent with an encounter‐reduction effect whereby adults reduced encounters between juveniles and infective larvae, but were not affected by the number of juveniles in a clan. Infection loads decreased with age, possibly because active immune responses to infection improved with age. Differences in parasite load between clans possibly indicate variation in abiotic environmental factors between clan den sites. The survival of juveniles (<365 days old) to adulthood decreased with Ancylostoma load, increased with age, and was modulated by maternal social status. High‐ranking individuals with low Ancylostoma loads had a higher survivorship during the first 4 years of life than high‐ranking individuals with high Ancylostoma loads. These findings suggest that high infection loads with energetically costly parasites such as hookworms during early life can have negative fitness consequences

Group therapy for binge eating in Type 2 diabetes: A randomized trial

Aims: This preliminary study addresses three related issues. First, there is a need to test the effectiveness of cognitive behavioural therapy (CBT) for binge eating in populations with Type 2 diabetes. Second, the impact of a treatment for binge eating on diabetes management is unknown. Finally, whilst a number of treatment modalities have been shown to improve binge eating, there has not been a comparison between CBT and a non-specific therapy for binge eating. Methods: Group CBT for binge eating was compared with a group nonprescriptive therapy (NPT), a therapy for which there is no theoretical or empirical support in eating disorders, in a randomized trial which included a post-treatment assessment and a 3-month follow-up. Results: There were no differences between CBT and NPT at post-treatment, with both treatments being associated with significant changes in binge eating, mood and body mass index. However, there was a significant relapse in binge eating at the 3-month follow-up in the NPT condition. This was in contrast to the CBT condition, where treatment gains were maintained. Finally, across treatments, reduction in binge eating from pre- to post-treatment was associated with reduction in HbA. Conclusions: Binge eating in Type 2 diabetes is responsive to psychosocial treatment, and reduction in binge eating appears to improve glycaemic control. However, this is a small study with a short follow-up period. Future studies will need to extend the follow-up period to assess for long-term maintenance of the effects of CBT on binge eating and diabetic control in this population