Importance of 68Ga-PSMA PET/CT in hospital practice. View of the radiation oncologist

Radiotherapy is a treatment with curative intent, both in patients with primary diagnosis of prostate cancer (PCa) and in patients presenting with biochemical recurrence after radical prostatectomy (RP). Moreover, the use of stereotactic body radiotherapy as a metastasis directed therapy in patients with oligometastatic PCa has significantly increased in the recent years. Conventional imaging techniques, including transrectal ultrasound, computed tomography (CT), morphologic magnetic resonance and bone scintigraphy have traditionally played a minor role in all those clinical scenarios due to its low diagnostic accuracy. The recent development of the positron emission tomography (PET) radiotracer ⁶⁸Ga-PSMA binding to the prostate specific membrane antigen (PSMA), a transmembrane glycoprotein overexpressed in PCa cells, has shown promising results. Detection rates for PCa lesions are higher than CT and higher than the best technique available, the PET/CT with choline. Its superiority has been demonstrated even at very low PSA levels (<1 ng/ml). This increase in diagnostic accuracy represents a potential impact on patient management, especially in radiotherapy. Even if this imaging technique is already available for routine clinical practice in some European countries, in Spain, unfortunately, there is very limited access. In this review, we analyze the main studies that investigate the usefulness of ⁶⁸Ga-PSMA PET/CT in patients with PCa and its potential impact on radiotherapy treatments. In addition, we compared the ⁶⁸Ga-PSMA PET/CT, with the multiparametric magnetic resonance imaging and the PET/CT with choline, in the different clinical scenarios.

Salmonella enterica Serotype Javiana Infections Linked to a Seafood Restaurant in Maricopa County, Arizona, 2016

On 10 August 2016, the Maricopa County Department of Public Health identified culture-confirmed Salmonella enterica serotype Javiana isolates from two persons who reported eating at a seafood restaurant; seven additional cases were reported by 15 August. We investigated to identify a source and prevent further illness. We interviewed persons with laboratory-reported Salmonella Javiana infection. Pulsed-field gel electrophoresis (PFGE) and whole genome sequencing of isolates were performed. A case was defined as diarrheal illness in a person during July to September 2016; confirmed cases had Salmonella Javiana isolate yielding outbreak-related PFGE patterns; probable cases had diarrheal illness and an epidemiologic link to a confirmed case. Case finding was performed (passive surveillance and identification of ill meal companions). A case-control study assessed risk factors for Salmonella Javiana infection among restaurant diners; control subjects were chosen among meal companions. No restaurant workers reported illness. Foods were reportedly cooked according to the Food Code. Food and environmental samples were collected and cultured; Salmonella Javiana with an indistinguishable PFGE pattern was isolated from portioned repackaged raw shrimp, halibut, and a freezer door handle. We identified 50 Salmonella Javiana cases (40 confirmed and 10 probable); illness onset range was from 22 July to 17 September 2016. Isolates from 40 patients had highly related PFGE patterns. Thirty-three (73%) of 45 patients interviewed reported eating at the restaurant. Among 21 case patients and 31 control subjects, unfried cooked shrimp was associated with illness (odds ratio, 6.7; 95% confidence interval, 1.8 to 24.9; P = 0.004). Among restaurant diners, laboratory and case-control evidence indicated shrimp as the possible outbreak source; poor thermal inactivation of Salmonella on shrimp is theorized as a possible cause. Cross-contamination might have prolonged this outbreak; however, the source was not identified and highlights limitations that can arise during these types of investigations.

Genitourinary syndrome of menopause. Prevalence and quality of life in Spanish postmenopausal women. The GENISSE study

OBJECTIVE

To determine the prevalence of genitourinary syndrome of menopause (GSM) and urogynecological conditions associated with menopause, and to evaluate the impact of GSM on quality of life in a cohort of Spanish postmenopausal women.

METHODS

Multicenter, cross-sectional, and observational study involving 430 women.

RESULTS

The prevalence of GSM was 70%. GSM was diagnosed in 60.2% of women with no known diagnosis of vulvovaginal atrophy or GSM. Most prevalent symptoms were vaginal dryness (93.3%) and reduced lubrication with sexual activity (90.0%). Most prevalent signs were decreased moisture (93.7%) and loss of vaginal rugae (78.4%). GSM was significantly associated with stress or mixed urinary incontinence, overactive bladder, and vaginal prolapse. Symptoms showed a low-moderate impact on quality of life, mainly in sexual functioning and self-concept and body image.

CONCLUSIONS

The GSM is very prevalent in Spanish postmenopausal women, affecting up to 70% of those consulting the gynecologist. Despite the high prevalence of symptoms and signs and its impact on the women's well-being, GSM remains underdiagnosed and undertreated. Given its relationship with urogynecological conditions, it seems necessary to provide an adequate evaluation of postmenopausal women for identifying potential co-morbidities and providing most adequate treatments. An adequate management of GSM will contribute to an improvement in the quality of life of these women.

Role of interactions in the magneto-plasmonic response at the geometrical threshold of surface continuity: publisher's note

This publisher's note amends the author listing of [Opt. Express26, 32792 (2017)].

Preventing childhood obesity in Latin America: an agenda for regional research and strategic partnerships

The increasing prevalence of childhood obesity in Latin America poses a major public health challenge to the region. In response, many countries are implementing obesity prevention programmes aimed at modifying known risk factors. However, the limited scientific evidence inhibits the development and implementation of novel, effective interventions across the region. To address these gaps, the NIH Fogarty International Center convened a workshop of researchers, policymakers, programme implementers and public health advocates who are actively engaged in the region to prevent childhood obesity. Major aims of the meeting were to define the current status of childhood obesity, identify the scientific gaps in our understanding of the epidemic, point out the barriers and opportunities for research and outline a plan for capacity building in the region in the area of childhood obesity. This series of articles reflects the key outcome of the meeting and offers an analysis of the knowledge translation needed for evidence-based policy initiatives, a review of the research agenda and an evaluation of research capacity in the region. The goal of the papers is to inform the development of multidisciplinary and multisector research collaborations, which are essential to the implementation of successful childhood obesity prevention strategies in the region.

Time-course of treatment-emergent adverse events in a long-term safety study of lisdexamfetamine dimesylate in children and adolescents with ADHD

Introduction

The long-term safety and efficacy of lisdexamfetamine dimesylate (LDX) in children and adolescents with attention deficit/hyperactivity disorder (ADHD) was evaluated in a European 2-year, open-label study (SPD489-404).

Objective

To evaluate the time-course of treatment-emergent adverse events (TEAEs) in SPD489-404.

Methods

Participants aged 6–17 years received open-label LDX (30, 50 or 70 mg/day) for 104 weeks (4 weeks dose-optimization; 100 weeks dose-maintenance).

Results

All enrolled participants (n = 314) were included in the safety population and 191 (60.8%) completed the study. TEAEs occurred in 282 (89.8%) participants; most were mild or moderate. TEAEs considered by the investigators as related to LDX were reported by 232 (73.9%) participants with the following reported for ≥ 10% of participants: decreased appetite (49.4%), weight decreased (18.2%), insomnia (13.1%). TEAEs leading to discontinuation and serious TEAEs occurred in 39 (12.4%) and 28 (8.9%) participants, respectively. The median (range) time to first onset and duration, respectively, of TEAEs identified by the sponsor as being of special interest were: insomnia (insomnia, initial insomnia, middle insomnia, terminal insomnia), 17.0 (1–729) and 42.8 (1–739) days; weight decreased, 29.0 (1–677) and 225.0 (26–724) days; decreased appetite, 13.5 (1–653) and 169.0 (1–749) days; headache, 22.0 (1–718) and 2.0 (1–729) days. Reports of insomnia, weight decreased, decreased appetite and headache were highest in the first 4–12 weeks.

Conclusions

TEAEs associated with long-term LDX treatment were characteristic of stimulant medications, with the greatest incidence observed during the first 4–12 weeks.

Disclosure of interest

The authors have not supplied their declaration of competing interest.

Faraday effect in hybrid magneto-plasmonic photonic crystals

We present a theoretical study of the Faraday effect in hybrid magneto-plasmonic crystals that consist of Au-Co-Au perforated membranes with a periodic array of sub-wavelength holes. We show that in these hybrid systems the interplay between the extraordinary optical transmission and the magneto-optical activity leads to a resonant enhancement of the Faraday rotation, as compared to purely ferromagnetic membranes. In particular, we determine the geometrical parameters for which this enhancement is optimized and show that the inclusion of a noble metal like Au dramatically increases the Faraday rotation over a broad bandwidth. Moreover, we show that the analysis of the Faraday rotation in these periodically perforated membranes provides a further insight into the origin of the extraordinary optical transmission.

Magnetic field modification of optical magnetic dipoles

Acting on optical magnetic dipoles opens novel routes to govern light-matter interaction. We demonstrate magnetic field modification of the magnetic dipolar moment characteristic of resonant nanoholes in thin magnetoplasmonic films. This is experimentally shown through the demonstration of the magneto-optical analogue of Babinet's principle, where mirror imaged MO spectral dependencies are obtained for two complementary magnetoplasmonic systems: holes in a perforated metallic layer and a layer of disks on a substrate.

Magnetic field modulation of chirooptical effects in magnetoplasmonic structures

In this work we analyse the magnetic field effects on the chirooptical properties of magnetoplasmonic chiral structures. The structures consist of two-dimensional arrays of Au gammadions in which thin layers of Co have been inserted. Due to the magnetic properties of the Au/Co interface the structures have perpendicular magnetic anisotropy which favours magnetic saturation along the surface normal, allowing magnetic field modulation of the chirooptical response with moderate magnetic fields. These structures have two main resonances. The resonance at 850 nm has a larger chirooptical response than the resonance at 650 nm, which, on the other hand, exhibits a larger magnetic field modulation of its chirooptical response. This dissimilar behaviour is due to the different physical origin of the chirooptical and magneto-optical responses. Whereas the chirooptical effects are due to the geometry of the structures, the magneto-optical response is related to the intensity of the electromagnetic field in the magnetic (Co) layers. We also show that the optical chirality can be modulated by the applied magnetic field, which suggests that magnetoplasmonic chiral structures could be used to develop new strategies for chirooptical sensing.

Comparative study of the neurotrophic effects elicited by VEGF-B and GDNF in preclinical in vivo models of Parkinson's disease

Vascular endothelial growth factor B (VEGF-B) has recently been shown to be a promising novel neuroprotective agent for several neurodegenerative conditions. In the current study we extended previous work on neuroprotective potential for Parkinson's disease (PD) by testing an expanded dose range of VEGF-B (1 and 10 μg) and directly comparing both neuroprotective and neurorestorative effects of VEGF-B in progressive unilateral 6-hydroxydopamine (6-OHDA) PD models to a single dose of glial cell line-derived neurotrophic factor (GDNF, 10 μg), that has been established by several groups as a standard in both preclinical PD models. In the amphetamine-induced rotational tests the treatment with 1 and 10 μg VEGF-B resulted in significantly improved motor function of 6-OHDA-lesioned rats compared to vehicle-treated 6-OHDA-lesioned rats in the neuroprotection paradigm. Both doses of VEGF-B caused an increase in tyrosine hydroxylase (TH)-positive cell and fiber count in the substantia nigra (SN) and striatum in the neuroprotective experiment. The effect size was comparable to the effects seen with GDNF. In the neurorestoration paradigm, VEGF-B injection had no significant effect in either the behavioral or the immunohistochemical analyses, whereas GDNF injection significantly improved the amphetamine-induced rotational behavior and reduced TH-positive neuronal cell loss in the SN. We also present a strong positive correlation (p=1.9e-50) of the expression of VEGF-B with nuclear-encoded mitochondrial genes involved in fatty acid metabolism in rat midbrain, pointing to the mitochondria as a site of action of VEGF-B. GDNF showed a positive correlation with nuclear-encoded mitochondrial genes that was not nearly as strong (p=0.018). VEGF-B counteracted rotenone-induced reduction of (a) fatty acid transport protein 1 and 4 levels and (b) both Akt protein and phosphorylation levels in SH-SY5Y cells. We further verified VEGF-B expression in the human SN pars compacta of healthy controls and PD patients, in neuronal cells that show co-expression with neuromelanin. These results have demonstrated that VEGF-B has potential as a neuroprotective agent for PD therapy and should be further investigated.

An insight into the role of autophagy in cell responses in the aging and neurodegenerative brain

Oxidative stress, inflammation and the aggregation of oxidized, misfolded or aberrant proteins in the brain induces deregulations in programmed cell death: apoptosis and autophagy. Apoptosis is one of processes implicated in aging and neurodegenerative pathologies, and for the last decade, has been one of the most studied processes due to its essential role, not only in aging, but also in many neurodegenerative diseases, including Parkinson's, Alzheimer's and Huntington's. However, autophagy being the major intracellular pathway for the degradation and recycling of long-live proteins and organelles is widely involved in the pathogenesis or prevention of many age-related diseases, including neurodegenerative conditions. Recently, autophagy activation has been considered as part of the cellular responses to elevated oxidative stress, eliminating unwanted, damaged and oxidative structures; thus favouring, in this way, the key anti-aging mechanism associated with the caloric restriction. Longevity factors, such as sirtuins, and redox-sensitive transcriptional factors, such as NF-κB and p53, can also regulate basal autophagy in cells, with a direct impact on longevity and the development of inflammation and neurodegeneration. Here, we reviewed the critical changes of autophagy in the aging and neuro-degenerative brain and the role of key regulators of autophagy, which are directly related to oxidative stress, inflammation and longevity pathways.

Converging pathways in the occurrence of endoplasmic reticulum (ER) stress in Huntington's disease

A variety of neurological diseases including Huntington's disease (HD), Alzheimer's disease and Parkinson's disease share common neuropathology, primarily featuring the presence of abnormal protein inclusions containing specific misfolded proteins. Mutations leading to expansion of a poly-glutamine track in Huntingtin cause HD, and trigger its misfolding and aggregation. Recent evidence indicates that alterations in the secretory pathway, in particular the endoplasmic reticulum (ER), are emerging features of HD. Although it is not clear how cytoplasmic/nuclear located mutant Huntingtin alters the function of the ER, several reports indicate that mutant Huntingtin affects many essential processes related to the secretory pathway, including inhibition of ER-associated degradation, altered ER/Golgi vesicular trafficking and axonal transport, disrupted autophagy and abnormal ER calcium homeostasis. All these alterations are predicted to have a common pathological outcome associated to disturbance of protein folding and maturation pathways at the ER, generating chronic ER stress and neuronal dysfunction. Here, we review recent evidence involving ER stress in HD pathogenesis and discuss possible therapeutic strategies to target organelle function in the context of disease.

Antioxidant responses to variations of oxygen by the Harderian gland of different species of the superspecies Spalax ehrenbergi

The subterranean blind mole rats of the superspecies Spalax ehrenbergi (Nehring, 1898) have developed several strategies to cope with changing concentrations of underground oxygen. Such an atmosphere induces the generation of reactive oxygen species that can cause oxidative damage without proper control. To understand how S. ehrenbergi appear to be able to counteract the free radicals and avoid oxidative damage, we studied the oxidative status of the Harderian gland (an organ particularly vulnerable to oxidative stress in many rodents) in two species of the superspecies S. ehrenbergi ( Spalax galili and Spalax judaei ) under different oxygen concentration levels, paying special attention to the antioxidant defences developed by these animals and the resulting macromolecular damage. The results presented herein reinforce the idea that S. ehrenbergi deal better with hypoxic conditions than other rodents by regulating the activity of its antioxidant enzymes. Moreover, S. galili is better adapted to hypoxic conditions, whereas S. judaei appears to be better adapted to hyperoxic conditions.

Association between obesity and kidney disease: a systematic review and meta-analysis

This study aimed to comprehensively assess epidemiologic evidence on the relation between obesity and kidney disease (KD). From 247 retrieved articles via PubMed (1980-2006), 25 cohorts, 3 cross-sectional, and 19 case-control studies met inclusion criteria. Related data were extracted using a standardized protocol. We estimated the pooled relative risk (RR) and 95% confidence interval (95% CI) of KD for each body mass index (BMI) category compared with normal weight using meta-analysis models. Population attributable risk was also calculated. Compared with normal-weight individuals (18.5<BMI<25), overweight individuals (25< or =BMI<30) had elevated risk for KD (RR=1.40; 95% CI 1.30-1.50); obese individuals were at much higher risk (RR=1.83 (1.57-2.13)). Obesity in women was associated with a higher risk than in men (RR=1.92 (1.78-2.07) vs 1.49 (1.36-1.63); P<0.001). Results from cohort studies in patient populations and cross-sectional and case-control studies all indicated a positive association between BMI and risks for KD outcomes. We estimated that 24.2% and 33.9% of KD cases among US men and women, respectively, and in industrialized countries, 13.8% in men and 24.9% in women, could be related to overweight and obesity. Obesity increases the risk for KD in the general population, and the association appears to be stronger in women than in men. Obesity adversely affects the progress of KD among patients with kidney-related diseases.

Use of body mass index to identify obesity-related metabolic disorders in the Chinese population

OBJECTIVE

To identify the body mass index (BMI; in kg/m2) cutoff that predicts the risk for obesity-related metabolic disorders for the Chinese population.

DESIGN

Community-based cross-sectional survey.

SETTING

Rural regions of Jiangxi and Anhui provinces and an urban community of Jing'an District of Shanghai, China.

SUBJECTS

Five hundred and twenty-nine non-pregnant, non-lactating urban and rural adults, aged 20-64 years without diagnosed diabetes.

RESULTS

Subjects were divided into two groups: with or without obesity-related metabolic disorders, which was defined as having at least one of the following: hypertension, insulin resistance, high plasma triacylglycerol, low-density lipoprotein-cholesterol or glucose. Gender-specific multiple logistic regression analysis demonstrated a significant dose-response relationship between BMI and obesity-related metabolic disorders, after adjusting for potential confounders. The lowest BMI interval associated with significant risk for both men and women (odds ratios of 2.67 and 3.46, respectively) was that of 22.5-24.4. Receiver-operating characteristic (ROC) curve analysis indicated that a BMI cutoff of 23 had the best combination of sensitivity and specificity and the shortest distance in the ROC curve, with positive and negative predictive values of 0.6-0.7 in both genders.

CONCLUSIONS

A BMI cutoff of 23 might be appropriate for use in identification of high risk of obesity-related metabolic disorders and serve as a public health action threshold in the Chinese population.

SPONSORSHIP

Center of a Livable Future, John Hopkins Bloomberg School of Public Health.

Obesity prevention in children: opportunities and challenges

OBJECTIVE

Longitudinal survey data from a number of countries confirm that the number of overweight children continues to increase at alarming rates, and even developing countries are experiencing a rise in their overweight population. There is ample consensus that prevention strategies are essential to turn the tide of the obesity epidemic, and yet there are still relatively few proven prevention approaches for children. This paper briefly discusses some of the common features of childhood obesity prevention programs, focusing on the experience in the US and Canada.

APPROACH

Most prevention programs include at least one of the following components: dietary changes, physical activity, behavior and social modifications, and family participation. School-based prevention programs may also include elements related to the school environment and personnel. Primary prevention programs cannot usually restrict caloric intake, but may effectively reduce the energy intake by reducing the energy density of foods, increasing offering of fresh fruits and vegetables, using low-calorie versions of products, and reducing offering of energy-dense food items. Physical activity interventions have recently focused more on reducing inactive time, particularly television viewing. Results from recent studies have reported success in reducing excess weight gain in preadolescents by restricting TV viewing.

SUMMARY

Integrating all the activities of a multi-component prevention intervention, and delivering and sustaining it in different environments, continues to be a major challenge for health professionals as well as for parents, educators, and children themselves. Still, encouraging progress has been made in several areas, and the increased awareness of the problem of childhood obesity by all concerned will continue to foster our efforts in this area.

Fortification, supplementation, and nutrient balance

Efforts to combat nutrient deficiencies have centered on supplemental nutrient administration and addition of selected nutrients to the food chain in the form of food fortification. Over the past several decades, and as the association between diet and chronic diseases became apparent, supplementation and fortification were also targeted at healthy individuals, with the aim of reducing their risk of future diseases such as cardiovascular diseases, diabetes, and cancer. While supplementation strategies are playing a major role in reducing micronutrient deficiencies around the world, there is less compelling evidence for their role in reducing risk of chronic diseases in healthy individuals, perhaps with the exception of folic acid and reduction of neural tube defects. Nevertheless, with our increasing understanding of the genetic heterogeneity of human nutrient requirements, it is likely that certain groups or populations may clearly benefit from higher intakes of certain nutrients. In addition to supplementation or fortification with specific nutrients, the consumption of certain dietary patterns (such as the Mediterranean diet) is associated with a reduced risk of chronic diseases, particularly cardiovascular diseases.

Early nutrition and risk of disease in the adult

The differentiation of key metabolic systems that occurs during intrauterine life is greatly influenced by environmental nutritional conditions, which in turn are related to maternal nutritional status. In postnatal life, childhood exposure to slow-acting environmental factors, primarily through the diet, will begin to condition adult susceptibility to diseases. Examples of these dietary factors are intake of saturated fat, sodium, calcium, etc. For example, bone calcium accumulation during childhood and adolescence will be a major determinant of risk of osteoporosis later in life. Similarly, a high intake of saturated fat during childhood may promote the process of atherosclerosis in persons with genetic susceptibility, thus accelerating the clinical manifestations of coronary heart disease in adult life. These findings, although still not completely clarified, constitute a significant opportunity for preventive intervention. While preventive intervention in adult life may reduce risk, this is usually difficult and results are often limited. One example would be obesity. In contrast, interventions early in life, aimed at reducing these early risk factors, could potentially result in major reductions in the incidence of several diseases of adults.

Bone mineral content in girls perinatally infected with HIV

BACKGROUND

Early diagnostic efforts and advances in multidrug therapy have considerably prolonged the survival time of children infected perinatally with HIV. Despite these advances, few studies have addressed calcium status and bone growth in HIV-infected children.

OBJECTIVE

Our objective was to examine the effect of HIV infection on calcium status and bone growth in children.

DESIGN

We measured calcitropic hormones, urinary calcium excretion, bone mineral content, and body composition in 19 young girls aged 9.2 +/- 2.6 y (range: 5.9-15.2 y) who were infected perinatally with HIV.

RESULTS

Serum concentrations of 1,25-dihydroxyvitamin D [1,25(OH)(2)D] and parathyroid hormone concentrations were elevated above normal ranges in 25% and 12% of these girls, respectively. Urinary calcium excretion normalized for creatinine excretion was also elevated (Ca/Cr >0.18) in 17% of these children despite suboptimal calcium intakes (679 +/- 437 mg/d). Total-body bone mineral content, measured with the use of dual-energy X-ray absorptiometry, averaged 845.1 +/- 279.0 g and was on average 2.7 z scores below age- and race-matched values reported in non-HIV-infected healthy girls. Significant positive correlations were found between an indirect marker of bone resorption in urine (N:-telopeptide) and 1,25(OH)2D (P < 0.02, r2 = 0.586, n = 9), and between serum N-telopeptide and total alkaline phosphatase (P < 0.001, r2 = 0.541, n = 17), suggesting that calcium insufficiency may be increasing bone resorption in this group.

CONCLUSIONS

Young girls with HIV infection had low bone mass and evidence of calcium insufficiency. Nutritional counseling of children with HIV infection should emphasize adequate calcium intakes because of the importance of this age period in bone mineral acquisition.

Diet culture and obesity in northern Africa

The etiology of obesity in North Africa is not well understood and few studies shed any light on its development among women. This study compiles what is known about the prevalence of obesity and its determinants in Morocco and Tunisia. Results from the authors' two surveys on nutrition-related disease among reproductive-age women (sample size: 2800) and their children (1200 children under 5 y and 500 adolescents) were combined with data from four national income and expenditure surveys (dating from 1980) to assess obesity trends and development in Morocco and Tunisia. Overall levels of obesity, identified by body mass index (BMI) > or = 30 kg/m(2), were 12.2% in Morocco and 14.4% in Tunisia. Obesity is significantly higher among women than among men in both countries (22.7% vs. 6.7% in Tunisia and 18% vs. 5.7% in Morocco) and prevalence among women has tripled over the past 20 y. Half of all women are overweight or obese (BMI > 25) with 50.9% in Tunisia and 51.3% in Morocco. Overweight increases with age and seems to take hold in adolescence, particularly among girls. In Tunisia, 9.1% of adolescent girls are at risk for being overweight (BMI/age > or = 85th percentile). Prevalence of overweight and obesity are greater for women in urban areas and with lower education levels. Obese women in both countries take in significantly more calories and macronutrients than normal-weight women. The percentage contribution to calories from fat, protein and carbohydrates seems to be within normal limits, whereas fat intake is high (31%) in Tunisia and carbohydrate intake (65-67%) is high in Morocco. These are alarming trends for public health professionals and policy makers in countries still grappling with the public health effects of malnutrition and micronutrient deficiencies. Health institutions in these countries have an enormous challenge to change cultural norms that do not recognize obesity, to prevent significant damage to the public's health from obesity.

Introduction. Symposium: Obesity in developing countries: biological and ecological factors

Over the past decade there has been an increasing concern about the impact of chronic, noncommunicable diseases on the health of developing world populations. Traditionally, major causes of illness and death in developing countries have been linked to infectious diseases and undernutrition, and these are still major public health problems in several regions of the world. But recent projections indicate that in 20 y noncommunicable diseases will account for over 60% of the disease burden and mortality in the developing world. Obesity is recognized as an underlying risk factor for many of these chronic conditions. As in developed societies, the risk for obesity in developing countries is also strongly influenced by diet and lifestyle, which are changing dramatically as a result of the economic and nutrition transition. This symposium discusses key aspects of the phenomenon of obesity in the developing world and provides some specific examples from countries facing increasing prevalence of that condition.

Estimation of body fat from anthropometry and bioelectrical impedance in Native American children

OBJECTIVE

Obesity, as measured by body mass index, is highly prevalent in Native American children, yet there are no valid equations to estimate total body fatness for this population. This study was designed to develop equations to estimate percentage body fat from anthropometry and bioelectrical impedance as a critical part of Pathways, a multi-site study of primary prevention of obesity in Native American children.

DESIGN

Percentage fat was estimated from deuterium oxide dilution in 98 Native American children (Pima/Maricopa, Tohono O'odham and White Mountain Apache tribes) between 8 and 11 y of age. The mean fat content (38.4%+/-8. 1%) was calculated assuming the water content of the fat-free body was 76%. Initial independent variables were height, weight, waist circumference, six skinfolds and whole-body resistance and reactance from bioelectrical impedance (BIA).

RESULTS

Using all-possible-subsets regressions with the Mallows C (p) criterion, and with age and sex included in each regression model, waist circumference, calf and biceps skinfolds contributed least to the multiple regression analysis. The combination of weight, two skinfolds (any two out of the four best: triceps, suprailiac, subscapular and abdomen) and bioelectrical impedance variables provided excellent predictability. Equations without BIA variables yielded r2 almost as high as those with BIA variables. The recommended equation predicts percentage fat with a root mean square error=3.2% fat and an adjusted r2=0.840.

CONCLUSION

The combination of anthropometry and BIA variables can be used to estimate total body fat in field studies of Native American children. The derived equation yields considerably higher percentage fat values than other skinfold equations in children.

Overweight and obesity among Alaskan Eskimos of the Bering Straits Region: the Alaska Siberia project

OBJECTIVE

To document the height, weight, BMI and prevalence of obesity for Eskimo residents of four villages of the Bering Straits Region of Alaska.

DESIGN AND SUBJECTS

454 Non-pregnant residents over 24 y of age, with at least one Eskimo grandparent participated in one cross sectional survey within each village.

MEASUREMENTS

Height, weight, calculation of BMI (kg/m2), proportion of 'overweight' (BMI 25-29.9), and proportion of 'obese' (BMI>/=30).

RESULTS

For women and men, respectively, mean heights were 153.4 and 165.2 cm; weights were 64.2 and 71.6 kg; and BMI were 27.2 and 26.2 kg/m2 after age standardization. For women, 27.9% were overweight, and 32.8% were obese compared with 36.2% and 15.6%, respectively, for men. Alaskan Eskimo participants of the Alaska Siberia Project had a significantly lower proportion of total overweight (BMI>/=25, 54.9% for women, and 32.0% for men) compared with the three sites of the Strong Heart Study, which ranged from 65.9 to 80.2% for women and 53.6 to 66.7% for men. Compared with American men of all races, the proportion of overweight and obese participants was similar for Eskimo men. The proportion of obese was significantly higher for Eskimo women compared with American women of all races, but the proportion of overweight was similar.

CONCLUSION

Although the prevalence of obesity among the Alaskan Eskimos is lower than for American Indians, the high proportion of overweight observed in this study is of concern for Alaskan Eskimo adults, especially for women.

Dietary Approaches to Stop Hypertension: a summary of study results. DASH Collaborative Research Group

The Dietary Approaches to Stop Hypertension multicenter trial examined the impact of dietary patterns on blood pressure in 459 adults with blood pressure < 160 mm Hg systolic and 80 to 95 mm Hg diastolic. After a 3-week run-in period on a control diet low in fruits, vegetables, and dairy products, and with a fat content typical for Americans, participants were randomized for 8 weeks to either the control diet, a diet rich in fruits and vegetables, or a combination diet that emphasized fruits, vegetables, and low-fat dairy products. Body weight and sodium intake were held constant, and physical activity did not change during the intervention. Baseline mean +/- standard deviation systolic and diastolic blood pressures were 131.3 +/- 10.8 mm Hg and 84.7 +/- 4.7 mm Hg, respectively. Relative to the control diet, the combination diet reduced blood pressure by 5.5 mm Hg and diastolic blood pressure by 3.0 mm Hg (P < .001). For those on the fruits and vegetables diet, blood pressure reductions relative to control were 2.8 mm Hg systolic (P < .001) and 1.1 mm Hg diastolic (P < .07). In 133 participants with hypertension, the combination diet produced a net blood pressure reduction of 11.4 and 5.5 mm Hg systolic and diastolic, respectively (P < .001). In participants without hypertension (n = 326), the corresponding blood pressure reductions were 3.5 mm Hg systolic (P < .001) and 2.1 mm Hg diastolic (P < .003). In other subgroup analyses, minorities showed relatively larger reductions in blood pressure than nonminorities (P < .001). We conclude that the dietary pattern reflected in the combination diet can substantially reduce blood pressure, and, accordingly, provides an additional lifestyle approach to preventing and treating hypertension.

Bacteria isolated from rock art paintings: the case of Atlanterra shelter (south Spain)

The Sierra de la Plata is an Aljibe yellow sandstone formation from the Acheulian period. There are a few shelters, some of them with rock art paintings. The most representative one, and subjected to anthropogenic pressure, is that of Atlanterra, situated in a residential area. This shelter contains some rock art paintings made with iron oxides. The bacteria present in these paintings were isolated and identified using an automatic method: fatty acid methyl esters profiling. Most of the bacteria belong to the Bacillus genus, B. megaterium being the most abundant species. The isolated strains are able to reduce hematite. This is significant due to the fact that Fe(III)-(hydr)oxides are the most abundant pigments in rock art.

Design and statistical analysis for the Pathways study

We report the design, rationale, and statistical procedures used in Pathways, a randomized, school-based intervention for the primary prevention of obesity in American Indian children. The intervention, which is now being implemented in 7 American Indian communities around the country, includes a health-promotion curriculum, a physical education program, a school meal program, and a family involvement component. Forty-one schools serving American Indian children were randomly assigned to be either intervention or control groups. The intervention will begin in the third grade and continue through the end of the fifth grade. Efficacy of intervention will be assessed by differences in mean percentage body fat, calculated by a prediction equation, between intervention and control schools at the end of the fifth grade. Power computations indicate that the study has power to detect a mean difference of 2.8% in body fat. Data analysis will use intention-to-treat concepts and the mixed linear model. The study will be completed in 2000.

Body composition assessment in American Indian children

Although the high prevalence of obesity in American Indian children was documented in several surveys that used body mass index (BMI, in kg/m2) as the measure, there is limited information on more direct measurements of body adiposity in this population. The present study evaluated body composition in 81 boys (aged 11.2+/-0.6 y) and 75 girls (aged 11.0+/-0.4 y) attending public schools in 6 American Indian communities: White Mountain Apache, Pima, and Tohono O'Odham in Arizona; Oglala Lakota and Sicangu Lakota in South Dakota; and Navajo in New Mexico and Arizona. These communities were participating in the feasibility phase of Pathways, a multicenter intervention for the primary prevention of obesity. Body composition was estimated by using a combination of skinfold thickness and bioelectrical impedance measurements, with a prediction equation validated previously in this same population. The mean BMI was 20.4+/-4.2 for boys and 21.1+/-5.0 for girls. The sum of the triceps plus subscapular skinfold thicknesses averaged 28.6+/-7.0 mm in boys and 34.0+/-8.0 mm in girls. Mean percentage body fat was 35.6+/-6.9 in boys and 38.8+/-8.5 in girls. The results from this study confirmed the high prevalence of excess body fatness in school-age American Indian children and permitted the development of procedures, training, and quality control for measurement of the main outcome variable in the full-scale Pathways study.

Plasma insulin levels and incidence of hypertension in African Americans and whites

BACKGROUND

Hyperinsulinemia may play an important role in the pathogenesis of hypertension in whites but the role of hyperinsulinemia in hypertension in African Americans is controversial.

SUBJECTS AND METHODS

We studied the relationship between insulin levels and subsequent incidence of hypertension in 140 African Americans and 237 whites who were initially screened for possible participation in the Trials of Hypertension Prevention, phase 1. Plasma insulin and serum glucose were measured at baseline and at a follow-up examination 7 years later. Blood pressure was measured by trained observers using a random-zero sphygmomanometer. Incident hypertension was defined as an average systolic pressure of 160 mm Hg or higher and/or diastolic pressure of 95 mm Hg or higher at a single visit and/or use of antihypertensive medication during follow-up.

RESULTS

Over the 7 years of follow-up, the incidence of hypertension was 25.7% in the African Americans and 25.3% in the whites. Baseline plasma insulin and insulin-to-glucose ratio were associated with an increased risk of hypertension in both the African Americans and the whites. After adjustment for age, sex, race, body mass, heart rate, and alcohol consumption at baseline as well as intervention assignment in the Trials of Hypertension Prevention, phase 1, a 1-SD (21 pmol/mmol) difference in baseline insulin-to-glucose ratio was associated with a 2.77 (95% confidence interval, 1.48-5.19) odds ratio of hypertension in the African Americans and a 1.69 (95% confidence interval, 1.08-2.64) odds ratio in the whites.

CONCLUSION

These results suggest that higher plasma insulin levels are associated with an increased risk of hypertension in both African Americans and whites.

Whole body protein turnover in children with human immunodeficiency virus (HIV) infection

The purpose of this study was to determine the rate of whole body protein turnover (WBPT) in human immunodeficiency virus (HIV)-infected children, and to determine the relationship between WBPT and growth. The rate of WBPT was calculated from the cumulative excretion of labeled urinary ammonia after a single intravenous dose of 15N-glycine in three groups of children: 1) HIV+ with growth retardation (HIV+ Gr); 2) HIV+ with normal growth (HIV+); and 3) HIV-uninfected with normal growth (HIV-). Twenty-six children between 2 and 11 y of age were studied (10 HIV+ Gr, 12 HIV+, 4 HIV-). All children were afebrile and free of acute infection during the study. Rates of WBPT (mean +/- SD) for the study groups were: HIV+ Gr, 12.2 +/- 4.8; HIV+, 10.7 +/- 5.1; and HIV-, 8.6 +/- 2.1 g.protein.kg-1.d-1 (NS, P > 0.05). Although not statistically significant, mean WBPT was 42% greater in HIV+ Gr, and 24% greater in HIV+ compared to HIV-. Statistically significant correlations were found between WBPT and Z scores for height (r = -0.39, P = 0.05) and weight-for-age (r = -0.51, P = 0.01) and dietary intake of protein (r = 0.39, P = 0.05), and between protein balance (synthesis-catabolism) and intakes of energy (r = 0.47, P = 0.02) and protein (r = 0.40, P = 0.04). There was no statistically significant correlation between WBPT and resting energy expenditure (r = 0.27, P = 0.19), or CD4 cell number (r = 0.05, P = 0.82). These data suggest an association between increased rates of protein turnover and low weight and height-for-age Z scores, and that it may be possible to achieve positive protein balance given an adequate intake of nutrients.

Compartmental modeling of human lactation

A difficult task for a novice modeler is beginning a modeling project. The methods described here delineate the modeling process step by step. Aristole is quoted as having said "One learns to play the flute by playing the flute," and the same principle holds somewhat for modeling. An excellent means for understanding modeling is to work with example models, altering rate coefficients and model structure, to learn first-hand the mechanics of the process. An excellent resource for viewing and downloading published models is the Library of Mathematical Models of Biological Systems, and can be accessed via the World Wide Web at the address http://gopher.dml.georgetown.edu/model/model.html++ + . This modeling library provides access to working models of biological systems. Experimenting with available examples of models, such as those presented in this volume and those available through the Modeling Library, provides an excellent opportunity for new modelers to get started in compartmental modeling.

Resting energy expenditure and body composition in children with HIV infection

The purpose of this study was to determine whether alterations in body composition, resting energy expenditure (REE), and dietary energy intake are associated with growth retardation in HIV-positive children. Body composition (deuterium oxide dilution, skinfold measurements), REE (indirect calorimetry), and energy intake (24-hour weighed food intake) were evaluated in three groups: HIV-positive with growth retardation (HIV+Gr), HIV-positive with normal growth (HIV+); and HIV-uninfected with normal growth (HIV-). Children were between 2 and 11 years of age, afebrile, and free from acute infection. Forty-two children (13 HIV+Gr, 19 HIV+, 10 HIV-) were studied. Lean body mass was significantly reduced in HIV+Gr compared with HIV- (p < .05), and fat mass was significantly reduced in HIV+Gr and HIV+ compared with HIV- (p < .05). The percentages of lean and fat mass were not significantly different between groups, suggesting that differences in lean and fat mass were proportional to differences in body size. Consistent with reduced lean body mass, mean REE was significantly lower in HIV+Gr compared with HIV- (p < .05). Differences in mean REE/kg of body weight or lean body mass between groups were not statistically significant. A significant negative correlation was found between REE (kcal/kg/day) and weight-for-age (p = .04), and a trend with height-for-age Z-score (p = .07). Mean energy intake was not significantly different between groups. This study suggests that lean and fat mass are proportionately reduced in HIV-positive children with growth retardation. Further studies are necessary to delineate the relationship between energy balance and growth in children with HIV infection.

Serum and plasma markers of nutritional status in children infected with the human immunodeficiency virus

OBJECTIVE

To determine whether reduced serum or plasma protein and micronutrient levels are common in children infected with the human immunodeficiency virus (HIV) and whether these levels are different in children with growth retardation compared to those with normal growth.

SUBJECTS

Children were separated into three groups: (a) HIV-infected with growth retardation (HIV + Gr); (b) HIV-infected with normal growth (HIV+); (c) HIV-uninfected with normal growth (HIV-). All children were afebrile and free of acute infection at the time of study. During a 24-hour stay in the Pediatric Clinical Research Unit, blood was drawn for analysis of total protein, albumin, zinc, selenium, and vitamin A levels; growth measurements were obtained; and dietary intake was assessed by 24-hour weighed food intake and 24-hour dietary recall.

STATISTICAL ANALYSIS

Mean differences between groups were assessed by analysis of variance, and differences in the frequency of nutrient deficiency were determined by chi 2 analysis.

RESULTS

Thirty-eight children between 2 and 11 years of age were studied: 10 HIV + Gr, 18 HIV+, and 10 HIV-. No statistically significantly differences were noted in mean levels of albumin, prealbumin, zinc, and selenium. Mean serum level of vitamin A was significantly higher in the HIV + Gr group than in the other two groups. There were no significant differences between groups in the frequency of deficiency for any nutrient studied. Mean energy and nutrient intake was similar among groups.

APPLICATIONS/CONCLUSIONS

Abnormal serum or plasma protein or micronutrient levels were uncommon in this cohort of HIV-infected children, even in children with growth retardation. Routine monitoring of the level of proteins and micronutrients studied is unnecessary in the absence of specific clinical indicators of deficiency.

High bone mass as a marker for breast cancer risk

Postmenopausal women in the highest quartile for metacarpal bone mass were found to have an increased risk of developing breast cancer, after adjusting for age and other variables known to influence breast cancer risk. Although the mechanisms responsible for this relationship have not been identified, postmenopausal bone mass may serve as an indicator of cumulative estrogen exposure.

Environmental factors affecting nutritional status in urban areas of developing countries

The demographic and economic transition that many developing countries are undergoing is producing important changes in diet and lifestyle that greatly impact on disease risks. Among the risk behaviors associated with socioeconomic transition and urbanization are excessive dietary fat intake, sedentary lifestyle, smoking, and environmental contamination. Combined with a reduced infant mortality and increased life expectancy, those risk factors lead to an increasing prevalence of chronic disease like non-insulin dependent diabetes and coronary heart disease. This disease. This disease profile is a relatively new phenomenon in developing countries, where health programs have traditionally focused on "acute" interventions such as immunization or oral rehydration. A new approach will be needed to address chronic diseases, which frequently demand a life-long and technically complex medical management, and may have significant impact on the quality of life and productivity of the population. Efforts to address this situation should focus on a) expanding the information base on diet, nutritional status and lifestyle changes in populations migrating to urban areas; b) developing and evaluating approaches for improving diet quality in urban populations, including fortification and community-based supplementation programs; c) understanding better the social and behavioral determinants of nutritional status in the urban poor; and d) defining the role of the food industry and of agricultural production for improving the quality of the food supply in urban areas.

Epidemic optic and peripheral neuropathy in Cuba: a unique geopolitical public health problem

During 1992 and 1993 an epidemic of optic and peripheral neuropathy affected over 50,000 Cubans. This occurred in the unique setting of a communist country which had a widespread health care network and wherein sudden changes in the economy affected most of the population. Although nutritional factors appeared to play a key role in the pathogenesis of the epidemic neuropathy, viral, toxic, and genetic factors were investigated by Cuban and North American scientists. The authors, representing different disciplines and different groups that visited Cuba during the epidemic, review and reflect on the clinical and laboratory findings which became available through their own experience and through reviewing the literature. The recent Cuban epidemic is compared to similar outbreaks of optic and peripheral neuropathy which have occurred in the past.