First inventory of marine debris on Alegranza, an uninhabited island in the Northeast Atlantic

Alegranza is the most northerly island of the Canary Islands archipelago, the first obstacle crossed by the Canary Current. From July to October 2020, six expeditions were led to the island to make a first inventory of marine debris and its possible source and origin. In total, 3667 objects weighing 321 kg were removed, excluding wooden objects. Of these, 97.7% were plastics, the most abundant being drink bottles (25.4%). While knowing the origin, source and pathway of debris is difficult, legible labels provided valuable information. In Alegranza, 66.7% of the legible bottle labels indicated Asian countries of manufacture, which is evidence that the source is maritime traffic in the region. The lobster trap license labels from the east coast of the United States and Canada were dated from 1999 to 2018, supporting both the exogenous origin and long lifetime in the ocean of these debris.

Overweight and obesity status from the prenatal period to adolescence and its association with non-alcoholic fatty liver disease in young adults: cohort study

OBJECTIVE

To examine the associations of maternal and child overweight status across multiple time-points with liver fat content in the offspring during young adulthood.

DESIGN

Cohort study.

SETTING

ELEMENT Cohort in Mexico City.

POPULATION

Pregnant women with singleton births (n = 97).

METHODS

We quantified hepatic triglyceride content (liver fat content) by proton magnetic resonance spectroscopy (1H MRS) and conventional T2-weighted MRIs (3T scanner) in 97 young adults from the ELEMENT birth cohort in Mexico City. Historical records of the cohort were used as a source of pregnancy, and childhood and adolescence anthropometric information, overweight and obesity (OWOB) were defined. Adjusted structural equation models were run to identify the association between OWOB in different life stages with liver fat content (log-transformed) in young adulthood.

MAIN OUTCOME

Maternal OWOB at the time of delivery was directly and indirectly associated with the liver fat content in the offspring at young adulthood.

RESULTS

Seventeen percent of the participants were classified as having NAFLD. We found a strong association of OWOB between all periods assessed. Maternal OWOB at time of delivery (β = 1.97, 95% CI 1.28-3.05), and OWOB status in the offspring at young adulthood (β = 3.17, 95% CI 2.10-4.77) were directly associated with the liver fat content in the offspring. Also, maternal OWOB was indirectly associated with liver fat content through offspring OWOB status.

CONCLUSION

We found that maternal OWOB status is related to fatty liver content in the offspring as young adults, even after taking into account OWOB status and lifestyle factors in the offspring.

TWEETABLE ABSTRACT

There was an association between pre-pregnancy overweight and the development of NAFLD in adult offspring.

Pitfalls of the self-regulation of advertisements directed at children on Mexican television

BACKGROUND

There are no academic studies that characterize advertisements directed at children from the companies that signed the self-regulation.

OBJECTIVE

The aim of this paper was to assess the extent and nature of food advertisements and the persuasive techniques used to market unhealthy food and beverages (UFB) to children, by signatory companies of self-regulation.

METHODS

From December 2012 to April 2013, 600 h of programming were recorded on the four broadcast public television channels in Mexico with the highest rating nationwide. Marketing aimed at children directly (broadcast on children's programmes or advertisements with a specific appeal to children) or indirectly (aimed at other target audiences with messages or scenes that link children to the product) were considered.

RESULTS

About 74.9% (2148) of the total food and beverage advertisements tried to influence children directly and indirectly. Companies, which had signed the self-regulation, focused 92.7% of their advertisements on UFB. Of the total number, 23.9% were aimed at children, 7.1% at adolescents, 12.5% at parents and 56.2% at the general public. Most of these advertisements were broadcast on movies (29.8%), cartoons (18%), soap operas (17.6%), entertainment shows (17.2%) and sports programs (6.4%).

CONCLUSION

Despite the self-regulation of television marketing, children were surrounded by UFB advertisements. Signatory companies influence children indirectly by targeting other audiences and by marketing during family television programs, which are also watched by children.

Prevention of childhood obesity and food policies in Latin America: from research to practice

BACKGROUND

Addressing childhood obesity in Latin America requires a package of multisectoral, evidence-based policies that enable environments conducive to healthy lifestyles.

OBJECTIVE

Identify and examine key elements to translating research into effective obesity policies in Latin America.

METHODS

We examined obesity prevention policies through case studies developed with an expert in the specific policy. Policies were selected based on their level of implementation, visibility and potential impact to reduce childhood obesity. They include: (i) excise taxes on sugar sweetened beverages and energy-dense foods; (ii) front-of-package food label legislation; (iii) trans fatty acids removal from processed foods; and (iv) Ciclovías recreativas or 'open streets'. Case studies were coded to identify components that explained successful implementation and sustainability using the Complex Adaptive Health Systems framework.

RESULTS

The analysis identified key elements for effective and sustainable policy, including evidence justifying policy; evidence-based advocacy by civil society; political will; and legislation and skillful negotiations across government, academia, the private sector and civil society. Scientific evidence and evaluation played an important role in achieving tipping points for policies' launch and sustain effective implementation.

CONCLUSIONS

Well-coordinated, intersectoral partnerships are needed to successfully implement evidence-based anti-obesity policies. Prospective policy research may be useful for advancing knowledge translation.

A research agenda to guide progress on childhood obesity prevention in Latin America

Childhood obesity rates in Latin America are among the highest in the world. This paper examines and evaluates the many efforts underway in the region to reduce and prevent further increases in obesity, identifies and discusses unique research challenges and opportunities in Latin America, and proposes a research agenda in Latin America for the prevention of childhood obesity and concomitant non-communicable diseases. Identified research gaps include biological challenges to healthy growth across the life cycle, diet and physical activity dynamics, community interventions promoting healthy child growth, and rigorous evaluation of national food and activity programs and regulatory actions. Addressing these research gaps is critical to advance the evidence-based policy and practice in childhood obesity tailored to the Latin American context that will be effective in addressing obesity.

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.

Mexico attempts to tackle obesity: the process, results, push backs and future challenges

Mexico's obesity prevalence is one of the world's highest. In 2006, academics, and federal and state government agencies initiated efforts to design a national policy for obesity prevention. The Ministry of Health (MOH) established an expert panel to develop recommendations on beverage intake for a healthy life in 2008. Subsequently, the MOH, with support from academia, initiated the development of the National Agreement for Healthy Nutrition (ANSA). ANSA was signed by all relevant sectoral actors in 2010 and led to initiatives banning sodas and regulating unhealthy food in schools and the design of other yet to be implemented initiatives, such as a front-of-package labeling system. A main challenge of the ANSA has been the lack of harmonization between industry interests and public health objectives and effective accountability and monitoring mechanisms to assess implementation across government sectors. Bold strategies currently under consideration include taxation of sugar-sweetened beverages, improvement of norms for healthy food in schools, regulation of food and beverage marketing to children and implementation of a national front-of-pack labeling system. Strong civil society organizations have embraced the prevention of obesity as their goal and have used evidence from academia to position obesity prevention in the public debate and in the government agenda.

Maternal knowledge and use of a micronutrient supplement was improved with a programmatically feasible intervention in Mexico

In Mexico, the potential impact on child malnutrition from a nutritional supplement (papilla) delivered through a conditional transfer program (Oportunidades) was attenuated by problems of household utilization. A behavioral change through communication intervention was developed to improve supplement utilization. Our study assessed the efficacy of this intervention through the results of a randomized trial. In 2 states (Veracruz and Chiapas) 2 clusters of communities were randomly assigned to intervention or control groups. Data were obtained from 176-198 mothers in intervention and control communities using a survey questionnaire at preintervention baseline and at a 5-mo follow-up. Concordance between reported and observed behaviors was examined through an observational substudy. The 4 behavioral recommendations were: 1) prepare papilla as a pap; 2) administer the preparation every day; 3) administer it between breakfast and dinner; and 4) administer it only to target children. The intervention resulted in a significant increase (P<0.05) in the prevalence of reported correct behaviors in the intervention group compared with the control for 3 of the behaviors: a mean increase of 42.5% for preparing papilla as pap, 64.4% for daily administration, and 61.5% for giving papilla between breakfast and dinner. Administering to a target child increased significantly in Veracruz (from 51.5% to 90.6%), but not in Chiapas (20.6% to 33.3%). Reported behaviors agreed with observed behaviors in the substudy. With the exception of the target-child administration in Chiapas, adopting the recommendations was culturally acceptable and feasible. The results indicate that improvements in household utilization of the supplement can be achieved with a communication intervention that is potentially feasible for implementation on a large scale within the Oportunidades Program.

Hormonal manipulation of benign metastasizing leiomyomas: report of two cases and review of the literature

Benign metastasizing leiomyomas (BMLs) occur predominantly in women during reproductive years. The condition is characterized by uterine leiomyomas associated with the development, typically years later, of slow-growing metastatic lesions. The most commonly affected organs are the lungs, but BMLs have been reported in lymph nodes, deep soft tissues, mesentery, bones, the central nervous system, and the heart. In many cases, these lesions have an indolent course and are discovered rather incidentally. However, occasionally they can present with debilitating symptoms or even life-threatening complications. The presence of estrogen and progesterone receptors in these tumors supports their origin from uterine smooth muscle and, more importantly, makes them amenable to hormonal manipulation. Radical interventions, such as extensive tumor debulking and oophorectomy for hormonal control, although effective in many cases, are not always possible or desirable and carry significant morbidity. Here we present two cases of BMLs to illustrate the role of newer therapeutic agents, the estrogen receptor modulators and the aromatase inhibitors, in the hormonal manipulation of these tumors.

Multiple micronutrient supplementation increases the growth of Mexican infants

BACKGROUND

The role of single micronutrient deficiencies in the etiology of growth retardation has recently gained attention. However, because multiple micronutrient deficiencies are common in children in developing countries, it is possible that more than one micronutrient may limit growth and, hence, the correction of a single deficiency may not be enough to improve growth substantially.

OBJECTIVE

The objective was to evaluate the effect of multiple micronutrient supplementation on the growth of children aged 8-14 mo whose diets were poor in several micronutrients.

DESIGN

Children were randomly assigned to 1 of 2 groups. One group received a multiple micronutrient supplement containing the recommended dietary allowance (RDA) or 1.5 times the RDA of vitamins A, D, E, K, C, B-1, B-6, B-12, riboflavin, niacin, biotin, folic acid, and pantothenic acid, and iron, zinc, iodine, copper, manganese, and selenium. The other group received a placebo. Supplements were administered 6 d/wk for an average of 12.2 mo. Body length was measured at baseline and monthly thereafter until the end of supplementation.

RESULTS

Supplemented infants initially aged <12 mo had significantly greater length gains than did the placebo group, with a difference of 8.2 mm (length-for-age z score: 0.3) at the end of supplementation. In contrast, differences in length gains between the supplemented and placebo groups initially aged > or =12 mo were not significant.

CONCLUSIONS

Micronutrient deficiencies limited the growth of the Mexican infants studied. Improving micronutrient intakes should be a component of interventions to promote growth in infants living in settings where micronutrient intakes are inadequate.

Reductive electrochemistry of spiromethanofullerenes

The synthesis and electrochemical properties of spiromethanofullerenes 1-6 are described. The syntheses were achieved via the diazomethane route, and the regioisomeric distribution of bis-adducts 3 was determined by (1)H NMR, UV-vis, and HPLC analysis. The electrochemistry of these compounds in dichloromethane exhibits, besides several reversible reductions, some irreversible waves. Reductive electrolysis of 1 and 3-5 in dichloromethane leads to the removal of the addend and thus to the formation of C60. Reductive electrolysis of 1, 2 and 6 in dichloromethane leads to a different reaction, which we tentatively assign to a reaction with the solvent to form fullerene-CH2Cl products. Electrolyses in the less reactive solvent THF lead to adduct removal for 1 and 3-5. Interestingly, significant formation of bis-adducts from the corresponding monoadducts was observed for 4 and 5. These electrochemically induced reactions, namely addend removal, reaction with the solvent, and addend transfer are influenced by the structure of the addend and by the choice of solvent.

In vivo efficacy of a bioartificial liver in improving spontaneous recovery from fulminant hepatic failure: a controlled study in pigs

BACKGROUND

Bioartificial liver may be useful as a bridge to liver transplantation but there are no data of its efficacy in successfully bridging to spontaneous recovery in fulminant hepatic failure. The aim of our study was to evaluate the efficacy of a bioartificial liver in increasing the spontaneous recovery of pigs with hepatic failure.

METHODS

The bioartificial liver consisted in a semipermeable dialyzer with 0.6 x 10(9) cryopreserved allogenic hepatocytes. Hepatic failure was induced by portacaval shunt plus 70% hepatectomy and 1 hour occlusion of the hepatic artery. Forty-one pigs were distributed 24 hr after liver failure induction to a group treated with the bioartificial liver (4 hr daily) until recovery or death (n=16), or to a control group (n=25). Intracranial pressure was monitored in 18 additional pigs, before and 4 hr after treatment with the bioartificial liver with (n=12) or without hepatocytes (n=6).

RESULTS

Fifteen days after induction of hepatic failure, 44% of the treated animals had survived and recovered from liver failure versus 22% controls (P=0.030). Intracranial pressure decreased from 13.13+/-5.1 to 7.19+/-2.06 mmHg (P=0.02) in treated animals, and remained unchanged in sham-treated animals (14.08+/-1.92 to 12.54+/-3.82, ns).

CONCLUSIONS

Bioartificial liver increases survival and allows spontaneous recovery in pigs with fulminant hepatic failure.

Association of maternal short stature with stunting in Mexican children: common genes vs common environment

OBJECTIVE

To evaluate the association between stunting in children and maternal short stature, controlling for potential environmental confounders.

DESIGN

1988 Mexico National Nutrition Survey.

SETTING

Mexico

SUBJECTS

The final sample size was 4663 pairs of children (<5 y) and their mothers (12-49 y) from a total of 13 236 surveyed houses.

MAIN OUTCOME MEASURES

Stunting (height-for-age Z-scores <-2).

RESULTS

The prevalence of stunting in children was 19%, and 10% of the mothers exhibited short stature (<145 cm). In the crude analysis, mothers with short stature were significantly more likely to have stunted children (odds ratio (OR)=4.0; 95% confidence interval (CI)=3.2-4.8; P-value <0.001). In a multiple logistic regression model the OR for child stunting was reduced, but remained significant OR=2.0; 95% CI=1.6-2.6; P-value <0.001) after adjustment for region, urban/rural residence, socio-economic status, household size, child age and presence of infection in the past 14 d, and maternal age, body mass index (BMI), and educational level. Adjusted ORs varied between regions (Mexico City, OR=3.9; North Mexico, OR=3. 1; Central Mexico, OR=2.0; South Mexico, OR=1.6. Comparison of crude vs adjusted estimates pointed to regional differences in the proportion of association between maternal and child short statures explained by environmental determinants.

CONCLUSIONS

Maternal stature, reflecting her potential height and early environment, appeared to contribute to child height independently of the shared risk factors that could affect stature. Nonetheless, we could explain much of the association between stunting in children and maternal short stature by environmental factors, and part of the residual variability may be due to unmeasured determinants. Regional differences pointed to a predominance of environmental factors in explaining child stunting in poorer regions.

On the protective mechanisms of nitric oxide in acute pancreatitis

BACKGROUND

Ectopic protease activation, microcirculatory changes, and leucocyte activation are the main events in the pathogenesis of acute pancreatitis. Nitric oxide (NO) is known to be a key mediator in the normal and inflamed pancreas.

AIMS

To investigate the targets on which NO exerts its effect in caerulein induced pancreatitis.

METHODS

Acute pancreatitis was induced in rats which additionally received either the NO synthase substrate, L-arginine; the NO donor, sodium nitroprusside; or the NO synthase inhibitor, N-nitro-L-arginine methyl ester (L-NAME). At six hours, pancreatic injury (oedema, leucocyte content, ectopic trypsinogen activation) was analysed and pancreatic oxygenation and perfusion were determined. A direct influence of NO on amylase secretion and trypsinogen activation was evaluated separately in vitro.

RESULTS

Both NO donors reduced the grade of inflammation. L-NAME increased the severity of inflammation, while decreasing pancreatic tissue oxygenation. Although neither amylase secretion nor intracellular trypsinogen activation in caerulein stimulated pancreatic acini was influenced by either NO donors or inhibitors, both NO donors decreased intrapancreatic trypsinogen activation peptide (TAP) and pancreatic oedema in vivo, and L-NAME increased TAP.

CONCLUSIONS

NO protects against injury caused by pancreatitis in the intact animal but has no discernible effect on isolated acini. It is likely that in pancreatitis NO acts indirectly via microcirculatory changes, including inhibition of leucocyte activation and preservation of capillary perfusion.

Lexipafant fails to improve survival in severe necrotizing pancreatitis in rats

CONCLUSION

Lexipafant administration fails to improve survival or lessen the disease severity in two experimental models of severe acute pancreatitis.

BACKGROUND

The potent platelet activating factor antagonist Lexipafant has been shown to attenuate the biochemical and histologic changes associated with some animal models of acute pancreatitis, suggesting an important role for this cytokine in its pathogenesis. However, a survival advantage following Lexipafant administration has not been demonstrated. This study evaluates the effect of this platelet activating antagonist on survival in rat models of necrotizing and fulminant hemorrhagic pancreatitis.

METHODS

Sprague-Dawley rats underwent induction of either acute necrotizing (n = 40) or hemorrhagic pancreatitis (n = 36) with a time- and pressure-controlled bile duct infusion of 10 mM glycodeoxycholic acid (GDOC) or enterokinase 15 U/mL, in combination with supramaximal cerulein stimulation (5 micrograms/kg/h). Immediately after pancreatitis induction, rats were randomly divided into three groups and received Lexipafant (1 mg or 10 mg) or saline as a continuous intravenous infusion over 9 h. Twenty-four-hour survival rates were determined and severity of pancreatitis was assessed by pancreatic histology scores.

RESULTS

The survival rates for GDOC treated rats were 55% (saline), 50% (1 mg Lexipafant) and 50% (10 mg Lexipafant). As expected, all rats induced with enterokinase and treated with saline died with hemorrhagic pancreatitis within 24 h. The same was true of those treated with high- and low-dose Lexipafant, and there was no difference in survival time. Histology scores did not differ between Lexipafant-treated and control rats in either GDOC or enterokinase rats.

Lexipafant fails to improve survival in severe necrotizing pancreatitis in rats

CONCLUSION

Lexipafant administration fails to improve survival or lessen the disease severity in two experimental models of severe acute pancreatitis.

BACKGROUND

The potent platelet activating factor antagonist Lexipafant has been shown to attenuate the biochemical and histologic changes associated with some animal models of acute pancreatitis, suggesting an important role for this cytokine in its pathogenesis. However, a survival advantage following Lexipafant administration has not been demonstrated. This study evaluates the effect of this platelet activating antagonist on survival in rat models of necrotizing and fulminant hemorrhagic pancreatitis.

METHODS

Sprague-Dawley rats underwent induction of either acute necrotizing (n = 40) or hemorrhagic pancreatitis (n = 36) with a time- and pressure-controlled bile duct infusion of 10 mM glycodeoxycholic acid (GDOC) or enterokinase 15 U/mL, in combination with supramaximal cerulein stimulation (5 micrograms/kg/h). Immediately after pancreatitis induction, rats were randomly divided into three groups and received Lexipafant (1 mg or 10 mg) or saline as a continuous intravenous infusion over 9 h. Twenty-four-hour survival rates were determined and severity of pancreatitis was assessed by pancreatic histology scores.

RESULTS

The survival rates for GDOC treated rats were 55% (saline), 50% (1 mg Lexipafant) and 50% (10 mg Lexipafant). As expected, all rats induced with enterokinase and treated with saline died with hemorrhagic pancreatitis within 24 h. The same was true of those treated with high- and low-dose Lexipafant, and there was no difference in survival time. Histology scores did not differ between Lexipafant-treated and control rats in either GDOC or enterokinase rats.

Zinc supplementation improves the growth of stunted rural Guatemalan infants

The impact of zinc supplementation on the growth and body composition of Guatemalan infants was assessed in a community-based, double-blind intervention trial. Infants aged 6-9 mo were assigned randomly to receive 4 mL of a beverage containing 10 mg of zinc as zinc sulfate (n = 45) or a placebo (n = 44) daily (7 d/wk) for an average of 6.9 mo. The children's weight, length, mid-upper arm and head circumferences, and triceps skinfolds were measured at baseline and at 1-2 mo intervals until the end of supplementation. Midarm muscle area (MMA) was derived from the mid-upper arm circumference and triceps skinfolds measurements. Maternal anthropometry and family socioeconomic and demographic characteristics also were obtained. Zinc supplementation was associated with an overall increase of 0.61 cm2 in MMA (P = 0.02). Children who received zinc supplements had a mean length increment that was 0.75 cm greater than those who did not (P = 0.12). However, there was a significant interaction between treatment group and initial length-for-age status (P = 0.04), such that supplemented children who were stunted at baseline (length-for-age Z score less than -2) gained 1.40 cm more than stunted children who received the placebo. We conclude that zinc supplementation of these rural Guatemalan infants during 6. 9 mo increased accretion of fat-free mass and enhanced the linear growth of those who were stunted at baseline. Further research is required to determine whether zinc supplementation during longer periods of time may achieve larger and more generalized effects on physical growth.

Technetium-99m-labeled white blood cells: a new method to define the local and systemic role of leukocytes in acute experimental pancreatitis

OBJECTIVE

We developed a new method to quantitate leukocyte accumulation in tissues and used it to examine the time course and severity of acute experimental pancreatitis.

BACKGROUND

Leukocyte activation and infiltration are believed to be critical steps in the progression from mild to severe pancreatitis and responsible for many of its systemic complications.

METHODS

Pancreatitis of graded severity was induced in Sprague-Dawley rats with a combination of caerulein and controlled intraductal infusion. Technetium-99m (99mTc)-labeled leukocytes were quantified in pancreas, lung, liver, spleen, and kidney and compared with myeloperoxidase activity. The severity of pancreatitis was ascertained by wet/dry weight ratio, plasma amylase, and trypsinogen activation peptide in the pancreas. The time course of leukocyte accumulation was determined over 24 hours.

RESULTS

Pancreatic leukocyte infiltration correlated well with tissue myeloperoxidase concentrations. In mild pancreatitis, leukocytes accumulated only in the pancreas. Moderate and severe pancreatitis were characterized by much greater leukocyte infiltration in the pancreas than in mild disease (p < 0.01), and increased 99mTc radioactivity was detectable in the lung as early as 3 hours. 99mTc radioactivity correlated directly with the three levels of pancreatitis.

CONCLUSIONS

Mild pancreatitis is characterized by low-level leukocyte activation and accumulation in the pancreas without recruitment of other organs; marked leukocyte accumulation was found in the pancreas and in the lung in more severe grades of pancreatitis. These findings provide a basis for the pathophysiologic production of cytokines and oxygen free radicals, which potentiate organ injury in severe pancreatitis. This study validates a new tool to study local and systemic effects of leukocytes in pancreatitis as well as new therapeutic hypotheses.

Prevalence of activating K-ras mutations in the evolutionary stages of neoplasia in intraductal papillary mucinous tumors of the pancreas

OBJECTIVE

The purpose of the study was to determine the prevalence of activating K-ras mutations in the pancreas of patients with intraductal papillary mucinous tumors (IPMT) and to analyze their relation to the degree of site-specific histopathologic abnormality.

BACKGROUND

Intraductal papillary mucinous tumors of the pancreas have a biologic behavior that is significantly different from pancreatic ductal adenocarcinoma. Activating K-ras mutations, which may be important events in a multistage process of carcinogenesis, have been reported in IPMT.

METHODS

Forty-six different histologic specimens (comprising normal pancreatic ducts, hyperplasia, low-grade dysplasia, high-grade dysplasia-carcinoma in situ, and carcinoma) from 16 patients with IPMT and 9 specimens from patients with pancreatic ductal adenocarcinomas were designated by a pathologist. Genomic DNA was extracted from paraffin-embedded tissue sections after microdissection. The K-ras gene was amplified by polymerase chain reaction and subjected to DNA sequencing.

RESULTS

The K-ras mutations were detected in at least one specimen in 13 (81.2%) of 16 patients with IPMT. All mutations were found in codon 12. No codon 13 mutations were detected. The relative frequency of K-ras mutations in the different stages of IPMT was 16.7% in normal epithelium and papillary hyperplasia, 28.6% in low-grade dysplasia, and 57.1% in high-grade dysplasia-carcinoma in situ and invasive carcinoma. The K-ras mutations were detected in 6 (66%) of 9 pancreatic ductal adenocarcinomas.

CONCLUSIONS

The K-ras codon 12 point mutations are as frequent in IPMT as in ductal adenocarcinoma. A stepwise increase in the frequency of codon 12 mutations correlated with the stage of neoplastic evolution to cancer. This finding is consistent with an important role of K-ras gene mutations in the transformation from normal epithelium to invasive carcinoma in the majority of patients with IPMT.

Zinc supplementation affects the activity patterns of rural Guatemalan infants

Zinc deficiency has been associated with growth deficits, reduced dietary intake and appetite, and has been hypothesized to result in reduced activity. This randomized, double-blind, placebo-controlled study examined whether 10 mg of oral zinc as zinc sulfate, given daily for up to 7 mo, affected activity patterns of 85 Guatemalan infants recruited at 6-9 mo of age. Infant activity was assessed by time sampling-observation method at 10-min intervals during a 12-h data collection period, at base line, 3 and 7 mo follow-up. Motor development and the percentage of time infants were observed in various positions (being carried, lying down, sitting, crawling, standing or walking) and engaged in various activities (eating, sleeping, resting, crying/whining or playing) were compared by treatment group. No differences in motor development were observed by treatment group. However, at follow-up 2 (after 7 mo of supplementation), zinc-supplemented infants were significantly more frequently observed sitting up compared with lying down, and were playing during 4.18 +/- 1.95% (P < 0.05) more observations than unsupplemented infants. They were also somewhat less likely to be observed crying or whining (P < 0.10) compared with those receiving the placebo. These effects are independent of other factors including infant age, motor development, sex, maternal education, family socioeconomic status and nutritional status at base line. Further research must be conducted to determine the long-term developmental importance of these differences in activity patterns associated with zinc supplementation in this setting.

A rat model of pancreatic ductal adenocarcinoma: targeting chemical carcinogens

BACKGROUND

Current experimental models of pancreatic cancer either fail to reproduce the ductal phenotype or cause simultaneous cancers in other organs also. To develop an animal of pancreatic cancer that accurately mimics the human condition, we restricted carcinogenic exposure to the pancreas and specifically targeted ductal epithelial cells. Three different carcinogens were either implanted directly into the pancreas or infused into the pancreatic duct, with or without near-total pancreatectomy (as a means of inducing pancreatic ductal cell proliferation).

METHODS

Groups of male Sprague-Dawley rats were exposed to varying doses of dimethylbenzanthracine (DMBA), methynitronitrosoguanidine, or ethylnitronitrosoguanidine either through direct implantation into the pancreas or infusion into the pancreatic duct. Near-total pancreatectomy was added in all groups except two DMBA implantation groups. Surviving rats were killed at 3, 6, 9, or 12 months, and the pancreata were evaluated histologically.

RESULTS

All three carcinogens caused pancreatic inflammation, ductal hyperplasia, atypia, and dysplasia beginning by 3 months and becoming more prominent at later time points. Only DMBA caused frequent invasive pancreatic ductal adenocarcinoma, which was first evident by 6 months. The prevalence of pancreatic cancer among DMBA-treated rats evaluated after 10 months was 39% (19 of 49). The addition of pancreatic resection did not enhance pancreatic cancer development.

CONCLUSIONS

Of the strategies tested, only direct implantation of DMBA into the rat pancreas frequently produces pancreatic cancer histologically similar to human ductal adenocarcinoma. The development of hyperplastic, atypical, and dysplastic changes preceding and accompanying carcinomas suggests that these lesions are preneoplastic. This model recapitulates the progression from normal to neoplastic epithelium and is likely to be useful for the study of morphologic and molecular mechanisms underlying the early stages of pancreatic carcinogenesis and for the investigation of novel diagnostic and therapeutic techniques.

Pancreatic mucinous ductal ectasia and intraductal papillary neoplasms. A single malignant clinicopathologic entity

OBJECTIVE

The purpose of the study is to review a single institutional experience with mucinous ductal ectasia (MDE) and intraductal papillary neoplasms (IPNs) and to compare the clinicopathologic features of the two groups of tumors.

SUMMARY BACKGROUND DATA

Mucinous ductal ectasia and IPNs represent newly recognized categories of pancreatic exocrine tumors, previously confused with pancreatic cystic neoplasms. The natural history of MDE and IPN is not well understood, and it is unclear whether MDE and IPN represent two distinct tumors or the same clinicopathologic entity.

METHODS

The authors reviewed the clinical presentation, treatment, histopathology, and outcomes of 23 patients diagnosed with MDE or IPN at their institution over the past 6 years.

RESULTS

The mean age at presentation for the cohort of patients with MDE and IPN was 62.5 years. The prevalence of abdominal pain was 75%, jaundice 25%, weight loss 42%, steatorrhea 37.5%, diabetes 37.5%, and history of pencreatitis 29%. Serum CA 19-9 levels ranged from 0 to 5350 units/mL with high levels reflecting advanced disease. There were no significant differences between MDE and IPN with respect to these parameters. Both MDE and IPN comprised papillary villous epithelial neoplasms involving the main and large pancreatic ducts. The tumors ranged from a few millimeters in size to panductal and were distinguished easily from cystic neoplasms in all cases. Invasive carcinoma was present in 11 (46%) of 24 patients, carcinoma in situ in an additional 10 (42%) of 24 patients, and low grade dysplasia in the remaining 3 (12%) of 24 patients. Mucinous ductal ectasia and IPN differed histopathologically only in degree of mucin secretion and tumor location. Mucinous ductal ectasia, but not IPN, was characteristically mucin-hypersecreting and more frequently involved the head of the gland than did IPN (11/16 vs. 1/8 p < 0.04). All patients were explored surgically and 20 (83%) of 24 of the tumors were resectable with frozen section control of the duct margins (9 pancreatoduodenectomies, 4 distal pencreatectomies, 7 total pancreatectomies). Despite the 88% prevalence of cancer, the overall survival at a mean follow-up of 21 months was 13 (87%) of 15 for MDE and 5 (71%) of 7 for IPN.

CONCLUSIONS

Intraductal papillary neoplasms with or without MDE represent a spectrum of main duct papillary tumors ranging from adenoma to carcinoma with differing amounts of extracellular mucin production. Malignant IPNs with or without MDE typically exhibit extensive intraductal growth but are slow to invade the periductal tissues and slow to metastasize. The majority of patients with these tumors have resectable disease and a favorable prognosis; endoscopic therapy is inappropriate. The encompessing term intraductal papillary-mucinous tumors is appropriate.

Impact of zinc supplementation on morbidity from diarrhea and respiratory infections among rural Guatemalan children

OBJECTIVE

A community-based, randomized, double-blind intervention trial was conducted to measure the impact of zinc supplementation on young Guatemalan children's morbidity from diarrhea and respiratory infections.

METHODS

Children aged 6 to 9 months were randomly assigned to receive 4 mL of a beverage containing 10 mg of zinc (as zinc sulfate) daily (7 d/wk) for 7 months (n = 45) or a placebo (n = 44). Morbidity data were collected daily. Diagnoses of diarrhea, fever, and anorexia were based on mothers' definitions. Respiratory infections were defined as the presence of at least two of the following symptoms: runny nose, cough, wheezing, difficulty breathing, or fever.

RESULTS

High rates of diarrhea and respiratory infections were reported. Children from the placebo group had a 20% episodic prevalence of diarrhea, with 8 episodes/100 d, and a 7% episodic prevalence of respiratory infections, with 3 episodes/100 d. The median incidence of diarrhea among children who received zinc supplementation was reduced by 22% (Wilcoxon rank test), with larger reductions among boys and among children with weight-for-length at baseline lower than the median of the sample (39% reductions in both subgroups). Zinc supplementation also produced a 67% reduction in the percentage of children who had one or more episodes of persistent diarrhea (chi2 test). No significant effects were found on the episodic prevalence of diarrhea, the number of days per episode, or the episodic prevalence or incidence of respiratory infections.

CONCLUSIONS

The large impact of zinc supplementation on diarrhea incidence suggests that young, rural Guatemalan children may be zinc deficient and that zinc supplementation may be an effective intervention to improve their health and growth.

Dietary studies in countries experiencing a health transition: Mexico and Central America

Several countries, including Mexico, are experiencing changes in health patterns that are characterized by an increase in the prevalence of chronic diseases and changes in the principal causes of death, coexisting with deficiencies in the intake of energy and micronutrients, particularly in children. Several factors may explain these changes, including dietary habits. To evaluate food consumption in a population undergoing a health transition, a food-frequency questionnaire was developed, validated, and used to study the dietary determinants of chronic diseases in Mexico. Nutrient deficiency and the relation between maternal child-feeding behaviors and dietary intake by the child were evaluated with use of 24-h recalls, food-frequency methods. and estimation of food intake by observation. The observation method was extremely useful for studies in rural areas.

Analysis of K-ras oncogene mutations in chronic pancreatitis with ductal hyperplasia

BACKGROUND

K-ras oncogene mutations have been identified in up to 95% of pancreatic cancers, implying their critical role in their molecular pathogenesis. However, the earliest stage in which K-ras mutations can be detected in potential precursor lesions of pancreatic cancer remains unclear. This study evaluates pancreatic ductal hyperplasia in the setting of chronic pancreatitis, which predisposes to pancreatic cancer development, for K-ras codon 12 and 13 mutations.

METHODS

Paraffin-embedded surgical specimens from 42 patients with chronic pancreatitis were examined microscopically for the presence of ductal hyperplasia. Both hyperplastic and nonhyperplastic ducts were microdissected from the specimens that contained hyperplasia (11 of 42). Four of the remaining specimens without hyperplasia served as controls. Genomic DNA was extracted, and polymerase chain reaction and amplification of the K-ras oncogene was performed. Polymerase chain reaction products were evaluated by means of hybridization to mutant specific oligonucleotide probes and by means of automated DNA sequencing.

RESULTS

K-ras codon 12 mutations representing glycine to valine substitutions were present in 2 of (18%) 11 patients with ductal hyperplasia. No mutations were found in the controls without ductal hyperplasia.

CONCLUSIONS

Our study supports the premise that K-ras mutations develop in a subset of chronic pancreatitis associated hyperplasia and provides a genetic basis for the potential progression of chronic pancreatitis to pancreatic cancer.

The recovery of Guatemalan children with mild to moderate wasting: factors enhancing the impact of supplementary feeding

OBJECTIVES

The purpose of this study was to identify factors that enhance the recovery due to supplementary feeding in wasted children.

METHODS

Recovery rates were obtained in mild to moderately wasted 6- to 48-month-old rural Guatemalan children living in four villages. Children in two villages received a high protein-energy supplement (supplemented children), while children in the other villages received a low protein-energy supplement (nonsupplemented children). The difference in recovery rates between the groups was the attributable benefit. The net supplementation amounted to 11% of the recommended energy intake and its associated nutrients.

RESULTS

Attributable supplement benefits were achieved in younger children (6 to 24 months old) and increased with decreasing weight for length, longer duration of supplementation, and duration of diarrhea, but not with chronicity of wasting.

CONCLUSIONS

Supplementation's effectiveness can be improved in similar populations by programs targeted according to these findings.

Surgical approaches to benign and malignant tumors of the ampulla of vater

Ampullary tumors include a diverse group of benign and malignant neoplasms. A surgical approach to their management was initiated in 1899 by Halsted and continues to evolve. Surgical options include a spectrum of operative procedures designed to relieve symptoms and to remove malignant or potentially malignant tumors. This article discusses the issues relevant to ampullary tumor management with emphasis on the currently accepted and controversial aspects of the surgical approach.

Peritoneal exfoliative cytology and Ki-ras mutational analysis in patients with pancreatic adenocarcinoma

This is the first description of the detection of pancreatic adenocarcinoma peritoneal metastasis by established radiolabeled polymerase chain reaction (PCR) based Ki-ras mutational analysis. The present study evaluates both routine cytology and Ki-ras mutational analysis in the detection of peritoneal micrometastases in 24 subjects with pancreatic adenocarcinoma compared to seven control cases of chronic pancreatitis and seven control cases of cholecystitis. Locoregional extension, vascular invasion, and distal metastases were confirmed in 21/24 (88%) of the subjects with pancreatic adenocarcinoma by compute tomography, angiography, endosonography, or laparoscopy. The most common site of histologically confirmed extrapancreatic involvement was the vasculature (29%), followed by the liver (25%), duodenum (17%), peritoneum (17%), and lymph nodes (12%). Peritoneal lavage cytology was positive in 3/24 (12%) cases of pancreatic carcinoma while Ki-ras codon 12 mutational analysis was positive in 2/24 (8%). Two histologically confirmed cases of peritoneal metastases were not detected by either methodology, while peritoneal lavage cytology detected malignant cells in one case with histologically confirmed lymph node metastasis.

Age differences in the impact of nutritional supplementation on growth

Supplementary feeding programs are common in developing countries. These programs often cannot demonstrate an impact on child growth, however, possibly because they tend to reach older children. This study examines the impact of nutritional supplementation on annual growth rates in length and weight from birth to 7 y of age in 1208 rural Guatemalan children. A series of multiple linear regression models is used to control for initial body size, diarrheal disease, home diet, socioeconomic status and gender. During the first year of life, each 100 kcal/d (418 kJ) of supplement was associated with approximately 9 mm in additional length gain and 350 g in additional weight gain; the benefit decreased to approximately 5 mm in length gain and 250 g in weight gain during the 2nd y of life. Between 24 and 36 mo of age, supplement only had a significant impact on length. There was no impact of nutritional supplementation on growth between 3 and 7 y of age. Patterns were the same if supplement intakes were expressed as a percent of recommended allowances or growth was expressed as a percent of the expected rate. These impacts of nutritional supplementation on growth coincide with the ages when growth velocities, as well as growth deficits, are greatest in this population.

Nutritional supplementation during early childhood and bone mineralization during adolescence

To assess the long-term impact of nutritional supplementation on bone mineralization during adolescence, we studied 356 Guatemalan adolescents who participated from birth to 7 y of age in a controlled supplementation trial. Bone mineralization of the distal radius was assessed using single photon absorptiometry. Children who consumed more cumulative energy from the supplement during childhood had greater bone mineral content, bone width and bone mineral density during adolescence than those who consumed less energy. The associations remained after controlling for each subject's age and gender, and for the type of supplement consumed, but became statistically nonsignificant after adjusting for weight and stature. Because intake of supplement also was associated positively with weight and stature during adolescence, it is concluded that supplementing malnourished children can have a demonstrable long-term impact on bone mineralization, but that the effects are probably not beyond those due to improvements in overall somatic growth associated with supplementation.

Nutritional impact of supplementation in the INCAP longitudinal study: analytic strategies and inferences

From 1969 to 1977 a supplementation trial was conducted in Guatemala to ascertain the effects on physical and behavioral outcomes of improved nutrition in pregnant women and in preschool children. This paper reviews different strategies to analyze the effect of the intervention on physical growth. One strategy compares outcomes in two villages that were randomly allocated to receive Atole, a supplement containing high amounts of protein and energy, with values in two other villages that received Fresco, a beverage containing no protein and little energy. Both supplements contained micronutrients. This comparison of village means gives a probability significance statement (P < 0.005) that the difference in growth was because of the supplement intervention, although it does not specify the aspect of the intervention that caused the effect. Complementary strategies increase the credibility that the effect of the supplement was nutritional. Thus, analysis of the dose response with increasing supplement intake within the villages excludes the possibility that the above findings were the result of knowing which villages received which supplement (i.e., measuring biases). A greater effect in those most likely to respond nutritionally also increases the credibility that the mechanism was nutritional. In studying other behavioral and biomedical impacts of this supplementation intervention, analyses for credibility should always be included.

Nutrition in early life and the fulfillment of intellectual potential

The effects of early supplementary feeding on cognition are investigated using data collected during two periods in four Guatemalan villages. The first was the Institute of Nutrition of Central America and Panama (INCAP) longitudinal study from 1969 to 1977 and the second was a cross-sectional follow-up of former participants carried out in 1988-1989. The principal objective of these studies was to assess the differential effect of two dietary supplements, Atole containing 163 kcal/682 kJ and 11.5 g protein per cup or 180 mL and Fresco containing 59 kcal/247 kJ and 0 g protein per cup, that were given to mothers, infants and young children. Performance was assessed on a battery of psychoeducational and information processing tests that were administered during adolescence. Consistent differences between groups were observed on psychoeducational tests. Subjects receiving Atole scored significantly higher on tests of knowledge, numeracy, reading and vocabulary than those given Fresco. Atole ingestion also was associated with faster reaction time in information processing tasks. In addition, there were significant interactions between type of dietary supplement and socioeconomic status (SES) of subjects. In Atole villages, there were no differences in performance between subjects in the lowest and highest SES categories. On the other hand, performance in Fresco villages was best in the highest compared with the lowest SES group. After close scrutiny of alternative hypotheses, it is concluded that dietary changes produced by supplementation provide the strongest explanation for the test performance differences observed in the follow-up between subjects exposed to Atole and those exposed to Fresco supplementation.

Early nutritional supplementation and skeletal maturation in Guatemalan adolescents

The effect of early childhood nutritional supplementation on skeletal maturation at adolescence was investigated in 663 rural Guatemalans, aged 11-18 y. Skeletal maturation was assessed by the Tanner-Whitehouse-2 method. The subjects were former participants in the Institute of Nutrition of Central America and Panama longitudinal study of growth and development (1969-77) residing in four villages (two large and two small) in eastern Guatemala. The villages were randomized within pairs to receive either a high energy, high protein supplement (Atole) or a low energy supplement with no protein (Fresco). Skeletal maturity was observed across all villages to be delayed significantly relative to a British reference for boys < 14 y of age, but not for older boys or for girls < 14 y of age. Delays in girls > 14 years could not be determined reliably because many had reached maturity. Girls < 14 years from Atole villages were more advanced in skeletal maturity than similar age girls from Fresco villages but these differences were found only in comparisons of the large villages. The relationship between early nutrition and biological maturation at adolescence may be obscured in this sample by the advanced age at which the subjects were examined in adolescence.

Nutritional supplementation during the preschool years and physical work capacity in adolescent and young adult Guatemalans

A follow-up study (1988-89) was carried out in 364 rural Guatemalans, 11-27 y of age, who earlier had participated in a nutritional supplementation experiment. Among its objectives was the assessment of the long-term effects of the nutrition intervention on physical work capacity. Subjects and their mothers from two villages had available a high-energy, high-protein supplement (Atole: 163 kcal/682 kJ and 6.4 g protein per serving or 180 mL), whereas in two other villages a low-energy, no-protein supplement (Fresco: 59 kcal/247 kJ per 180 mL) was provided. Consumption was ad libitum. Maximum oxygen consumption (VO2max) at follow-up was significantly greater in Atole compared with Fresco subjects of both sexes. In subjects 14-19 y, exposed to supplementation throughout gestation and the first 3 y of life, Atole males had a significantly higher VO2max (2.62 L/min) than Fresco males (2.24 L/min), the differences remaining significant even after controlling for body weight and fat-free mass; also, there was a significant positive relationship between amount of supplement consumed and VO2max. The supplementation effect in females of similar age was not statistically significant. It is concluded that early nutritional improvements can have long-lasting effects on physical performance.

Age at menarche and nutritional supplementation

Retrospective data on age at menarche were collected for 832 Guatemalans 15-30 y in age to test whether exposure to a high energy and high protein supplement (Atole: 163 kcals/682 kJ and 11.5 g protein per cup or 180 mL) during childhood led to earlier menarche than did exposure to a low energy, no protein supplement (Fresco: 59 kcals/247 kJ in 180 mL). Mean age at menarche was similar in Atole (13.75 +/- 1.22 y; mean +/- SD) and Fresco (13.74 +/- 1.36 y) groups. The corresponding value for immigrants (n = 144), subjects not exposed to the supplements, was 13.55 +/- 1.20 y. Year of birth as well as socioeconomic status (SES) were associated with age at menarche. Age at menarche declined by 0.69 y over the 15-y period and menarche occurred earlier in higher SES households. Significant positive interactions between supplement type and SES and between supplement type and year of birth were found, but plausible explanations for them could not be advanced.

Nutritional supplementation during the preschool years influences body size and composition of Guatemalan adolescents

Effects of supplementary feeding during early childhood on body size and composition at adolescence are examined in a population with marked growth failure in the first 3 y of life. The data came from a supplementation trial conducted in rural Guatemala from 1969 to 1977 and a 1988-89 follow-up study of the same subjects at adolescence. Two pairs of villages participated in the trial. One village from each pair received a high protein-energy supplement (Atole), which significantly improved dietary intakes, whereas the other village of the pair received a low-energy, no-protein supplement (Fresco), which did not impact appreciably on dietary intakes. Children from Atole villages grew better during the preschool period than children from Fresco villages. At adolescence, subjects from Atole villages were taller, weighed more and had greater fat-free masses than subjects from Fresco villages. Differences in height at adolescence were slightly reduced in magnitude relative to differences at 3 y of age. However, differences in weight were increased in adolescence relative to 3 y of age.

Patterns of linear growth in rural Guatemalan adolescents and children

Length and weight data from a longitudinal study of rural Guatemalan subjects birth to 7 y of age and height and weight data from a cross-sectional study of the same subjects when they were 11-24.9 y old are compared to reference data for the USA general population and for Mexican-Americans. At birth, the median length of Guatemalan children is at approximately the 16th percentile of the USA reference or approximately 2 cm shorter. By 6 mo of age, Guatemalan children are shorter, on average, than the 5th percentile of the reference curves and, in absolute terms, are approximately 5 cm below the median; by 3 y, the difference increases to approximately 10 cm. As adults, Guatemalans have about the same absolute level of deficit (approximately 13 cm) as they did at age 3 y. If the general USA population is used for comparison, Guatemalans can be said to grow as expected during adolescence, neither recuperating the growth retardation of early childhood nor falling further behind in size. If the Mexican-American sample is selected instead, it would appear that some catch-up in growth occurs in Guatemalan adolescents. Regardless of the choice of reference population, growth is markedly retarded only in early childhood; adolescence is not a period when growth is significantly constrained.

In vitro activation of lipophilic tributyltins by superoxide produces tributylstannyl superoxo radicals, proposed initiators of lipid peroxidation: an EPR model study

Tri-n-butyltin(TBT) compounds having the chemical formula (C4H9)3SnX are broad-spectrum biocidal agents whose toxic effect is primarily at the membrane level. Red blood cells (RBC) exposed to micromolar concentrations of tributyltin compounds (TBTX) undergo morphological changes and hemolysis. Determination of the mechanism of action whereby TBT elicits membrane damage continues to be a challenging endeavor. Because xenobiotic TBT+ and endogenous O2.- have been found to penetrate and alter RBC membrane function, it is hypothesized that they may combine chemically within the RBC hydrophobic lipid bilayer during TBT insult to initiate lipid peroxidative processes. The present study has been designed (1) to determine if TBT+ and O2.- combine chemically in aprotic media and, if so, (2) to characterize any free-radical complex(es) generated. The reactions of the membrane-active TBTX compounds (X = OCH3, Cl, Br, or I) with O2.- have been investigated in the aprotic solvent system cis-dicyclohexano-18-crown-6 ether/DMSO using EPR techniques. When incremental amounts of each TBT halide were added to O2.- solutions at room temperature, the EPR signal characteristic of O2.- diminished in intensity and disappeared when a 1:1 O2.-/TBT+ mole ratio was attained. Although the same phenomenon was observed for all TBT halides used, only the KO2/TBTI reaction produced detectable amounts of a new oxygen-centered free-radical complex. The EPR spectral parameters calculated from the product anisotropic frozen glass spectra were gx = 2.054, a(x) = 31.7 G, gy = 2.021, gz = 2.002, gav = 2.026.(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of supplementary feeding on recovery from mild to moderate wasting in preschool children

Three-month recovery rates from moderate wasting (less than 90% weight-for-length) were compared in 6-24-mo-old children in four Guatemalan villages that had been randomly assigned to receive a moderate (Atole) or low (Fresco) energy supplement. The recovery rate (Rr) in the Atole villages was 12% higher than in the Fresco villages (P less than 0.05). This effect was above all due to the children in the Atole villages who consumed greater than or equal to 10% of the daily recommended dietary intake of energy (RDI) from the supplement (high-Atole group) and whose total energy intake (including home diet) was 10.5% of the RDI higher than a comparable high-Fresco group with low supplemental energy intake. All those in the high-Atole group whose wasting was due to malnutrition recovered. Much of this recovery (range 29-52%) was due to the increased supplementation. This proportion rose after potential confounding variables were controlled for.

Organophosphate poisoning

Organophosphate compounds insecticides are the most commonly associated with serious human toxicity. We reviewed the adult cases of organophosphate poisoning seen at HURRA from January 1986 to January 1990. We had 14 cases, all male patients. The most common mode of exposure was by ingestion in a suicidal attempt, (8/14 cases). The most common symptom observed was nausea (6/14 patients), and the most common sign was increased bronchial secretions (8/14 patients). Laboratory abnormalities were similar to those previously reported in the literature: leukocytosis (10/14 cases), hyperglycemia (5/14 cases) and hypokalemia (4/14 cases). Patients were treated following accepted guidelines. None of our patients developed seizures nor ventricular arrhythmias. One of our patients developed respiratory failure and required mechanical ventilation. Two patients developed pneumonic processes, requiring intravenous antibiotic therapy. The hospital stay of these two patients was prolonged (7 and 10 days respectively). For the other 12 patients, the hospital stay ranged from 2 to 4 days. We had no mortality in our series. We were able to obtain follow-up interview by telephone with 10 of the 14 patients and we did not find any history of symptoms of delayed clinical toxicity.

A highly thermostable proline:tRNA ligase from Thermus aquaticus. Purification and enzyme-tRNA recognition at elevated temperatures

Proline:tRNA ligase from Thermus aquaticus was purified to homogeneity and characterized. Its molecular weight was found to be 127 000, consisting of two identical subunits. It catalysed the prolylation of tRNAPro from Escherichia coli with a bell-shaped pH dependence peaking at about pH 7 and exhibited extreme thermostability. The Vm/Km ratios of steady-state kinetics for proline and ATP as well as tRNAPro were not extensively diminished even at 85 degrees C, but prolylation became insignificant at 90 degrees C. Since the melting of tRNAPro was in progress, yet incomplete, at 85 degrees C, these findings suggest that some threshold level of conformational integrity of tRNAPro, rather than the entire unmelted conformation of the molecule, is essential to effective recognition by the proline:tRNA ligase.