Search

This pre–post study used a mixed-methods approach to examine the impact of a family-based weight management program among a low-income population. Smart Choices for Healthy Families was developed through an integrated research–practice partnership and piloted with 26 children and parents (50% boys; mean age = 10.5 years; 54% Black) who were referred by their pediatrician. Smart Choices included six biweekly group sessions and six automated telephone-counseling calls over 3 months. Children displayed reduced body mass index z-scores ( p < .05), increased lean muscle mass ( p < .001), and increased quality of life ( p < .0001). Follow-up interviews indicated that physicians valued the lay leaders’ ability to provide lifestyle education, whereas lay leaders extended their reach to more community members. Parents wanted to become positive role models and found that the calls maintained focus on goals. Smart Choices shows promise to initiate weight management for children in low-income families.

In recently published studies, we show that angiotensin II (AII) generated from an engineered rat angiotensinogen cDNA, and maintained intracellularly, is growth stimulatory for a rat hepatoma cell line. In the present study, we report that co-expression of AII fused to cyan fluorescent protein (ECFP/AII) and angiotensin type I receptor fused to yellow fluorescent protein (AT1R/EYFP) enhances proliferation of COS-7 and CHO-K1 cells by 59% and 64%, respectively, compared to cells expressing the corresponding independent proteins (P < 0.001 for both). This effect is inhibited by losartan, suggesting (as in our previous published studies) that losartan is internalized by the cells, via receptor-mediated endocytosis, and thus inhibits intracellular receptor-ligand interaction. The growth effect is independent of anti-AII antibodies suggesting that it does not reflect AII secretion into the culture media; AII is also undetectable in the media. Expression of AT1R/EYFP with ECFP/AIIC (control scrambled sequence AII fused to ECFP) has no effect upon cell proliferation. ECFP/AII also alters the cellular localization of AT1R/EYFP. ECFP/AII is concentrated in the nucleus, but shows diffuse cytoplasmic fluorescence as well. AT1R/EYFP, expressed independently, is visible in the endoplasmic reticulum and Golgi apparatus of COS-7 and CHO-K1 cells as early as 24-h post-transfection. At 72 h, it is visibly associated with the plasma membrane. By 144 h, 85% of the cells show detectable circumferential fluorescence. In contrast, in cells that express AT1R/EYFP and ECFP/AII, both proteins accumulate in the nucleus and only 13% of the cells show visible plasma membrane-associated yellow fluorescence at 144 h (P < 0.001). Furthermore, co-expression of ECFP/AII with AT1R/EYFP stimulates cAMP response element-binding protein (CREB) activity in CHO-K1 and COS-7 cells. Exogenous AII similarly significantly increases CREB activation in AT1R/EYFP-stably transfected CHO-K1 and COS-7 cells.

Few comprehensive measures exist to assess contributors to childhood obesity within the home, specifically among low-income populations. The current study describes the modification and psychometric testing of the Comprehensive Home Environment Survey (CHES), an inclusive measure of the home food, physical activity, and media environment related to childhood obesity. The items were tested for content relevance by an expert panel and piloted in the priority population. The CHES was administered to low-income parents of children 5 to 17 years ( N = 150), including a subsample of parents a second time and additional caregivers to establish test–retest and interrater reliabilities. Children older than 9 years ( n = 95), as well as parents ( N = 150) completed concurrent assessments of diet and physical activity behaviors (predictive validity). Analyses and item trimming resulted in 18 subscales and a total score, which displayed adequate internal consistency (α = .74-.92) and high test–retest reliability ( r ≥ .73, ps < .01) and interrater reliability ( r ≥ .42, ps < .01). The CHES score and a validated screener for the home environment were correlated ( r = .37, p < .01; concurrent validity). CHES subscales were significantly correlated with behavioral measures ( r = −.20-.55, p < .05; predictive validity). The CHES shows promise as a valid/reliable assessment of the home environment related to childhood obesity, including healthy diet and physical activity.

ObjectiveDue to a proliferation of measures for different components of the home environment related to childhood obesity, the purpose of the present systematic review was to examine these tools and the degree to which they can validly and reliably assess the home environment.DesignRelevant manuscripts published between 1998 and 2010 were obtained through electronic database searches and manual searches of reference lists. Manuscripts were included if the researchers reported on a measure of the home environment related to child eating and physical activity (PA) and childhood obesity and reported on at least one psychometric property.ResultsOf the forty papers reviewed, 48 % discussed some aspect of parenting specific to food. Fifty-per cent of the manuscripts measured food availability/accessibility, 18 % measured PA availability/accessibility, 20 % measured media availability/accessibility, 30 % focused on feeding style, 23 % focused on parenting related to PA and 20 % focused on parenting related to screen time.ConclusionsMany researchers chose to design new measures for their studies but often the items employed were brief and there was a lack of transparency in the psychometric properties. Many of the current measures of the home food and PA environment focus on one or two constructs; more comprehensive measures as well as short screeners guided by theoretical models are necessary to capture influences in the home on food and PA behaviours of children. Finally, the current measures of the home environment do not necessarily translate to specific sub-populations. Recommendations were made for future validation of measures in terms of appropriate psychometric testing.

The in vivo absorption of 3-O-methyl-D-glucose (3MG) as a marker of intestinal function has not been studied in an animal model. We evaluated the use of 3MG as a marker of intestinal absorption when given enterally to rats recovering from small bowel mucosal injury induced by methotrexate (MTX). Radiolabeled 3MG was administered into the duodenum of control (CON) and MTX-treated rats and blood samples were obtained at specified intervals. Mucosal permeability was also assessed using radiolabeled mannitol and polyethylene glycol 900 (PEG). Concentration time points were plotted, and area under the curve was calculated as an approximation of absorbed dose. Mucosal weight, maltase activity, and protein content were determined on mucosal scrapings. During the acute phase (day 5), 3MG absorption and maltase-specific activity were significantly decreased in the MTX group when compared to the CON group (p less than 0.001). The MTX group showed a trend toward greater permeability to mannitol when compared to the CON group; however, this was not statistically significant. Mucosal permeability to PEG was similar in both groups. During a later stage in the recovery process (day 12), the area under the curve calculations for 3MG absorption were the same for both CON and MTX animals, with maltase activity in the MTX group recovering to control values. Changes in 3MG absorption paralleled total maltase activities following severe injury. These results suggest that the combined active and passive transport of 3MG in vivo could be of use as a marker of intestinal absorption in states where the small intestine has sustained major damage resulting in compromised absorption as well as brush border digestion.

Aluminum toxicity is a documented cause of encephalopathy, anemia, and osteomalacia. Excretion is primarily renal; therefore, patients with renal insufficiency are at risk for aluminum accumulation and toxicity. This has been demonstrated in uremic children treated with aluminum-containing antacids. The purpose of this study was to determine whether plasma aluminum levels were elevated in infants with normal renal function during prolonged aluminum-containing antacid use. Ten study infants (mean age = 5.8 months), who had been receiving antacids for at least 1 week, were compared with 16 control infants (mean age = 9.8 months) not receiving antacids. The study patients consumed 123 ± 16 mg/kg per day (mean ± SEM) of elemental aluminum for an average of 4.7 weeks. Their plasma aluminum level (37.2 ± 7.13 µg/L) was significantly greater than that of the control group (4.13 ± 0.66 µg/L) (P < .005). It is concluded that plasma aluminum levels may become elevated in infants with normal renal function who are consuming high doses of aluminum-containing antacids. The safety of antacids containing aluminum should not be assumed and they should be used judiciously in infants, with careful monitoring of the aluminum dose and plasma level.

The North American Society for Pediatric Gastroenterology, Hepatology, and Nutrition (NASPGHAN) performed a workforce survey to determine the number, distribution, and work-related activities of pediatric gastroenterologists in the United States of America (USA) and Canada, and compared these findings with the first workforce survey completed in 1996.The survey queried pediatric gastroenterologists in the USA and Canada between November, 2003 and June 2004. To permit the optimal comparison to the 1996 survey data, the original survey was used as a template for development of the current instrument and, when possible, the questions were left unchanged. Additional questions were added to address important contemporary issues not present in the initial survey. Limited income information was also collected. The survey was posted on the NASPGHAN website, and the NASPGHAN membership was notified of the survey by electronic mail via its electronic mail distribution list. This was followed by a three-part postal mail survey to all non-respondents. After the Internet and postal mail requests, all non-respondent physicians were telephoned a minimum of three times. If unsuccessful in contacting the physicians directly, office personnel were queried to facilitate survey completion regarding the provision of pediatric gastroenterology, nutrition or hepatology services in either clinical care or research.The response rate based on the potential contact list for Part I of the survey was 69%. The final phone call or electronic mail contact of an office staff member with questions regarding gender and delivery of pediatric gastroenterology services yielded a total contact rate of 88%. There were 699 pediatric gastroenterologists identified in North America, as compared with 672 in 1996. If known non-respondents are included, there could be as many as 794 pediatric gastroenterologists. Time spent in clinical activities increased from 60% to 66% in the USA and from 43% to 53% in Canada. The use of nurse practitioners and physician assistants has increased considerably over the past 7 years. Fifty-three percent of respondents feel there are too few pediatric gastroenterologists. Fifty percent of section and practice heads report that they are currently recruiting partners. Limited income information is presented.There is currently a self-perceived shortage of pediatric gastroenterologists as compared with 7 years ago, despite a constant proportion of pediatric gastroenterologists per million children. In the USA, nurse practitioners and physician assistants are being increasingly used to fill this need, and physicians in both Canada and the USA have increased the time they spend in clinical care.

Background: PEG disruptions during conversions to skin-level gastrostomy devices have been described, but specific risk factors have not been reported. In this study, possible risk factors for tract disruption in a pediatric population were identified, and management of complications described. Methods: The medical records of patients who underwent gastrostomy conversions during 1994 were reviewed. Statistical analysis was performed using two-tailed student's t test, and risk ratios with 95% confidence limits were calculated. Results: Gastrostomy tract disruption occurred in 6 of 30 (20%) of tube conversions. Complicated and uncomplicated cases did not differ with regard to age, sex, primary or associated diagnoses, pregastrostomy or postgastrostomy nutritional status, tract maturity, or percutaneous gastrostomy tube type. The use of an 18F obturator-type skin-level gastrostomy tube increased the risk for gastric separation 4.8-fold. Tract disruptions were managed by fluoroscopic gastrostomy tube replacement, repeat PEG, or exploratory laparotomy with open gastrostomy. Conclusions: The use of obturator-type skin-level gastrostomy tubes was associated with an increased risk of tract disruption. Fluoroscopic verification of intragastric placement is warranted after initial conversions to skin-level gastrostomy tubes. (Gastrointest Endosc 1996;44:230-4.)

Is it possible that extraterrestrial life forms exist within our Galaxy, the Milky Way? This book offers a critical analysis by leading experts in a range of sciences, of the plausibility that other intelligent lifeforms do exist. Exploration of the Solar System, and observations with telescopes that probe deep space, have come up empty handed in searches for evidence of extraterrestrial life. Many experts in the fields of astronomy, biology, chemistry and physics are now arguing that the evidence points to the conclusion that technological civilisations are rare. After ten billion years, and among hundreds of billions of stars, we may well possess the most advanced brains in the Milky Way Galaxy. This second edition contains many new and updated aspects of extraterrestrial research, especially the biological viewpoint of the question.

Are there intelligent beings elsewhere in our Galaxy? This is the question which astronomers are most frequently asked by laymen. The question is not a foolish one; indeed, it is perhaps the most significant of all questions in astronomy. In investigating the problem, we must therefore do our best to include all relevant observational data. Because of their training, most scientists have a tendency to disregard all information which is not the result of measurements. This is, in most matters, a sensible precaution against the intrusion of metaphysical arguments. In the present matter, however, that policy has caused many of us to disregard a clearly empirical fact of great importance, to wit: There are no intelligent beings from outer space on Earth now . (There may have been visitors in the past, but none of them have remained to settle or colonize here.) Since frequent reference will be made to the foregoing piece of data, in what follows we shall refer to it as ‘Fact A’. Fact A, like all facts, requires an explanation. Once this is recognized, an argument is suggested which indicates an answer to our original question. If, the argument goes, there were intelligent beings elsewhere in our Galaxy, then they would eventually have achieved space travel, and would have explored and colonized the Galaxy, as we have explored and colonized the Earth. However, (Fact A), they are not here; therefore they do not exist.

• Prenatally acquired cytomegalovirus infection in twins was temporally associated with a discordant development of neonatal hepatitis and extrahepatic biliary atresia. This case presents evidence suggesting an association between perinatal cytomegalovirus infection and selected extrahepatic biliary atresia and neonatal hepatitis. Congenital cytomegalovirus infections and cytomegalovirus hepatitis are also discussed. (AJDC.1991;145:302-305)

Intestinal disaccharidase expression in the developing post-natal animal is under a complex system of regulatory mechanisms involving pre-programmed genetic timing as influenced by circulating humoral factors, paracrine factors, and luminal nutrients. The aim of this study was to examine the relative contribution of circulating glucocorticoids and pre-programmed genetic expression of sucrase and lactase in a suckling mouse between post-natal days 13 and 15. We examined primary jejunal and ileal organ culture explants in serum-free medium at 0-2 hours and 22-24 hours of organ culture, respectively. Animals were studied at days 13, 14, and 15, with an additional group of adrenalectomy animals who underwent adrenalectomy on day 13 with organ culture at day 15. The results of sucrase activity are shown below. In summary, day 14 tissues in organ culture for 24 hours reached the same level of expression in organ culture of scrum-free media as in the intact animal on day 15. In addition, adrenalectomy on day 13 did not abolish the time-dependent expression of sucrase. However, the magnitude of expression in the basal state was diminished. We speculate that normal quantitative expression of intestinal disaccharidase in the 15-day suckling mouse is dependent upon a combination of intrinsic tuning in conjunction with circulating glucocorticoids.

A calculation of the net oxygen released by photosyn thesis, and of the possible sinks for such oxygen, shows clearly that the pre-biotic atmosphere of the earth must have been heavily reducing.

The effect of short-term (biochemical) and long-term (clinical) essential fatty acid (EFA) deficiency on mucosal adaptation was studied in a surgical model of short bowel syndrome. Rats fed an EFA-deficient diet for 4 wk had biochemical evidence of EFA deficiency (hepatic and red blood cell triene to tetraene ratios greater than 0.4). Resected animals (70% proximal jejunoileal resection) receiving an EFA-deficient diet had a significantly impaired intestinal mucosal hyperplasia response in all remaining small bowel segments compared with resected controls. The effect of refeeding a control diet to clinically EFA-deficient resected rats was also evaluated. Short-term refeeding (2 wk) of a control diet resulted in a significant return toward normal tissue triene to tetraene ratios. Concomitantly, refed animals had significantly greater mucosal adaptation in the remaining duodenal/jejunal segment compared with resected animals maintained on an EFA-deficient diet postoperatively. These experiments underscore the dynamic nature of tissue EFA status and the importance of fatty acids in the normal compensatory mechanisms of mucosal adaptation after resection.

Calculations show that a main sequence star which is less massive than the Sun has a continuously habitable zone about it which is not only closer in than the corresponding zone about the Sun, but is also relatively narrower. Let L(t) represent the luminosity after t billion years of a main sequence star of mass M, and let rinner and router represent the boundaries of the continuously habitable zone about such a star—that is, the zone in which an Earthlike planet will undergo neither a runaway greenhouse effect in the early stages of its history nor runaway glaciation after it develops an oxidizing atmosphere. Then our computer results indicate that r outer r inner is roughly proportional to [ L(3.5) L(1.0) ] 1 2 . This ratio is smaller for stars less massive than the Sun (because they evolve more slowly), and the width of the continuously habitable zone about a main sequence star is therefore a strong function of the initial stellar mass. Our calculations show that rinner = router for M∼0.83M⊚ (i.e., K1 stars), and it therefore appears that there is no continuously habitable zone about most K stars, nor any about M stars.

Computer simulations of the evolution of the earth's atmospheric composition and surface temperature have been carried out. The program took into account changes in the solar luminosity, variations in the earth's albedo, the greenhouse effect, variation in the biomass, and a variety of geochemical processes. Results indicate that prior to two billion years ago the earth had a partially reduced atmosphere, which included N2, CO2, reduced carbon compounds, some NH3, but no free H2. Surface temperatures were higher than now, due to a large greenhouse effect. When free O2 appeared the temperature fell sharply. Had earth been only slightly further from the sun, runaway glaciation would have occurred at that time. Simulations also indicate that a runaway greenhouse would have occurred early in earth's history had earth been only a few percent closer to the sun. It therefore appears that, taking into account the possibilities of either runaway glaciation or a runaway greenhouse effect, the continuously habitable zone about a solar-type star is rather narrow, extending only from roughly 0.95 to 1.01 AU.

The effect of zinc deficiency on glucose tolerance was investigated using intragastric force feeding to obviate decreased food intake and altered eating patterns. Three groups of weanling male Sprague-Dawley rats were fed a purified zinc-deficient diet: zinc-deficient, ad libitum-fed animals (ZDA) were offered powdered zinc-deficient diet; zinc-replete, force-fed controls (ZRF) were tube fed a diet blended with water containing 25 ppm of zinc; zinc-deficient, force-fed animals (ZDF) were similarly tube fed the zinc-deficient diet. The ZRF and ZDF groups received a diet of identical amount based on the intake of ad libitum-fed, zinc-replete rats. After 8 days of feeding, the ZDF group had impaired glucose tolerance curves, yet blood insulin and glucagon levels were normal. The ZDA group had normal glucose tolerance with low insulin levels compared with the ZRF group. The islet cell morphology among the three dietary groups were similar. These results suggest that the glucose intolerance observed in ZDF rats is not due to altered blood insulin and glucagon levels but rather to peripheral resistance to insulin action.

At the temperature of Pluto (∼43°K) the only gas which would neither condense nor escape is neon. Since neon is cosmically abundant it is suggested that Pluto may have a fairly extensive atmosphere consisting of almost pure neon. The possibility that such an atmosphere exists is analyzed, along with the possibility that oceans of liquid neon may exist at the surface. A neon atmosphere would not produce any observable absorption lines. However, if it were very thick, then Rayleigh scattering would result in Pluto having a much higher albedo in the ultraviolet than in the visual, which is not observed to be the case. This enables us to set an upper limit on the mass of Pluto's atmosphere.

To assess the influence of diamine oxidase activity on the adaptive process of the small bowel after resection, we administered aminoguanidine, a potent diamine oxidase inhibitor, to rats for 10 days after either small bowel transection (n = 5) or 80% jejunoileal resection (n = 7). Five or more additional animals from each group received saline as controls. Ileal mucosal homogenates from the resection group receiving aminoguanidine, when compared with those from resection controls, showed no diamine oxidase activity with increased putrescine content and ornithine decarboxylase activity. Mucosal proliferation, as measured by mucosal mass, protein content, and deoxyribonucleic acid content, was greater in the resected animals receiving aminoguanidine when compared with that of resection controls. Sucrase activity per gram of mucosa was almost identical in both resection groups. These results show that the suppression of diamine oxidase during the postresection adaptive period results in enhanced mucosal proliferation with no effect on mucosal functional differentiation. Diamine oxidase may play a regulatory role in adaptive intestinal proliferation.

The effects of cholecalciferol (formerly vitamin D-3) supplementation and alterations in dietary calcium levels on intestinal 210Pb absorption and tissue uptake were studied in weanling female Sprague-Dawley rats. Rats were placed in one of three groups: 1) normal dietary calcium with normal cholecalciferol; 2) low dietary calcium with normal cholecalciferol; or 3) normal dietary calcium with cholecalciferol supplementation. Blood 210Pb levels were determined at 3, 6, 12 and 24 hours following the administration of either an oral or an IP dose of 210Pb. Femur and kidney 210Pb activities were subsequently determined for all animals 24 hours after the administration of 210Pb. Cholecalciferol supplementation resulted in increased net intestinal absorption of 210Pb with uptake into femurs and kidneys. The effect of cholecalciferol to increase tissue uptake of 210Pb was shown to be independent of the effect of cholecalciferol on the gastrointestinal absorption of lead. A lowering of dietary calcium was shown to increase lead absorption with uptake into femurs; however, this increased tissue uptake of lead was shown to be dependent upon increased intestinal lead absorption and was not a direct effect of the low calcium diet.

We have shown that dietary long-chain triglycerides and 16,16-dimethyl prostaglandin E2 enhance and aspirin impairs postresection mucosal adaptation in rats. The present studies examined the hypothesis that supplemental linoleic acid (LA) above the minimum requirement may enhance postresection mucosal adaptation through altered prostaglandin (PG) synthesis. Forty male Sprague-Dawley rats (105 +/- 5 g) were fed purified diet containing either 5% LA or 4% palmitic acid and 1% LA. After 2 weeks, 12 rats from each dietary group underwent 70% proximal jejunoileal resection and the remainder were sham-operated. Dietary regimens were continued for an additional 13 days. Mucosal fatty acid analysis of 1% LA group revealed a ratio of 20:3 n-9/20:4 n-6 lower than 0.2, indicating normal essential fatty acid status. Mucosal protein per centimeter bowel was higher in the 5% LA group compared to the 1% group, but mucosal DNA, maltase, and ex vivo PG synthesis were not affected. These results indicate that LA stimulates postresection mucosal hypertrophy, which does not appear to be related to PG synthesis.

Postresection villus hyperplasia is a major compensatory mechanism in the short-bowel patient. Substances capable of augmenting postresection mucosal hyperplasia could have therapeutic implications. Human growth hormone (hGH) and human growth hormone releasing factor (hGHRF) stimulate growth of the gastrointestinal tract; however, the diabetogenic actions of growth hormone limit its usefulness in clinical practice. Plerocercoid larvae of the tapeworm Spirometra mansonoides produce an analog of hGH void of diabetogenic side effects. We assessed effects of plerocercoid growth factor (PGF) on mucosal adaptation following 70% proximal jejunoileal resection in young rats. Mucosal weight, DNA, protein, and total sucrase activity per centimeter of bowel were increased in resected PGF-treated animals compared to resected controls. We conclude PGF augments intrinsic postresection mucosal hyperplasia following extensive intestinal resection.

If N, the number of advanced technological civilizations in a typical galaxy the size of our own, were a large number, then the solar system would probably have been colonized long ago. We infer that N is small. The most likely cause of N being small is that flife (i.e., the fraction of suitable planets on which life actually arises) is very small; reasons are given why this should be so.

A case report of acute self-limiting colitis associated with enteric Cryptosporidium infection in an immunocompetent child is presented. This case broadens the spectrum of symptoms and manifestation of Cryptosporidium infection in a normal human host.

A case of primary intestinal lymphangiectasia is presented in which multiple blind peroral jejunal biopsies were unable to document any abnormality, despite strongly suggestive clinical history and radiographic findings. Endoscopically directed biopsy was necessary to document the characteristic pathologic lesion. This report documents the importance of endoscopy in the diagnosis of intestinal lymphangiectasia when clinical history is suggestive of intestinal lymphangiectasia but standard small bowel biopsy fails to show any abnormality.

Despite the mucosal hyperplasia that follows massive small bowel resection, changes in absorptive function are thought not to parallel changes in mucosal mass. This is described as “functional immaturity” of the new enterocytes. We approximated unidirectional glucose uptake using an inert glucose analogue, 3-0-Methylglucose(3MG). The study included 24 160 gram male Sprague-Dauley rats, half of which underwent 80% jejunoileal resection, the remainder being sham-operated. Six animals of each group were studied at post-op day 3 and six at post-op day 10. The unidirectional 3MG uptake was determined utilizing intestinal rings incubated for 3 minutes in KRB buffer at various concentrations of 3MG. The J value in resected animals is shown below in both duodenum and ileum at 10 mM concentration. Value x1000+SEM Despite a marked increase in mucosal mass, there was no significant difference in 3MG uptake between day 3 and day 10. No functional immaturity of the enterocytes at day 10 was apparent, suggesting that the marked increase in mucosal mass following resection is accompanied by the corresponding increase in glucose absorption.

Previous studies indicate long chain fats have trophic effects on post-resection intestinal mucosal adaptation. We have previously shown that short term essential fatty acid (EFA) deficiency impairs normal post-resection mucosal hyperplasia, while 16, 16 dimethyl-PGE2 administration stimulates hyperplasia. The effect of increased dietary linoleic acid (LA) on promoting mucosal adaptation in resected, non-EFA deficient animals was evaluated. Ten Sprague-Dauley rats (5 w/o males) were pair-fed isocaloric diets containing 1% or 5% (LA) (w/w). After 2 weeks all animals underwent 70% proximal jejunoileal resection. Animals were then pair-fed for 14 days. Following sacrifice mucosal weight, protein, DNA, and sucrase activity were determined: Protein levels were increased in all segments in 5% LA animals (p

Previous studies have shown that dietary long chain triglycerides stimulate mucosal hyperplasia following massive small bowel resection. In these studies, however, mucosal hyperplasia in “control” animals may have actually been inhibited by short term EFA deficiency. To evaluate this possibility 24 Sprague-Dawley rats were subjected to 60% proximal jejunoileal resection and subsequently pair-fed isocaloric diets containing either linoleic (control) or palmitic (EFA deficient) acid (5% fat by weight). Two weeks postoperatively, mucosal protein (mg/cm bowel + SEM) was determined in the remaining bowel:: Mucosal protein levels were decreased in EFA deficient resected animals in all segments in remaining bowel (p

Model stars whose convection zones had been prepared in accordance with the standard mixing-length theory were used as a basis for the computation of unstable convective modes. It was found that no superposition of statistically independent, nonviscous, adiabatic, convective modes can reproduce the radial dependence of the convective flux of the model. This implies that the representation of a stellar convection zone as a superposition of unstable adiabatic linear modes is inconsistent with the mixing-length theory, and that conclusions based upon such a representation should be regarded with caution. It is also shown that if the linear scale of convective motions is greater than (or of the same order as) the pressure scale height, then the fractional deviation of the pressure from equilibrium will generally not be negligible, as assumed in the mixing-length theory, but will be at least of the same order as the fractional deviation of the density from equilibrium.