Smaller Body Weight Research Articles

EFFECTS OF DIFFERING RESPONSE‐FORCE REQUIREMENTS ON FOOD‐MAINTAINED RESPONDING IN C57BL/6J MICE

The effect of force requirements on response effort was examined using inbred C57BL/6J mice trained to press a disk with their snout. Lateral peak forces greater than 2 g were defined as responses (i.e., all responses above the measurement threshold). Different, higher force requirements were used to define criterion responses (a subclass of all responses) that exceeded the requirement and produced a reinforcer. The reinforcer was sweetened, condensed milk, delivered upon response termination. All mice were exposed to two ascending series of criterion force requirements (2, 4, 8, 16, and 32 g). Increasing the force requirement initially decreased criterion response rates, but criterion response rates recovered with continued exposure, except at the 32-g requirement. Response rates for all measured responses initially increased with increasing force requirements, but then decreased with continued exposure. The second exposure series produced more stable response rate changes than the first series. The time-integral of force (area under the force-time curve for individual responses, which is proportional to energy expenditure for each response) increased with the increase in the force requirement. The C57BL/6J inbred strain generated average force output similar to CD-1 outbred stock mice trained on the same force requirements. C57BL/6J inbred strain mice differed from CD-1 mice in initial response rates (for all responses above threshold) and had lower response rates at the 16 and 32 g requirements resulting in lower total force output. These data show for both mice types that increased force requirements resulted in increased overall responding (all measured responses), which contradicts a punishment interpretation of criterion response decrements. C57BL\6 inbred mice showed individual differences comparable to the outbred CD-1 stock. C57BL/6 mice did not maintain responding as well at the higher force requirements, which may be due to their small body size and weight, compared to the larger and heavier CD-1 mice.

Moters savo kūno suvokimas kaip socializacijos rizikos veiksnys

Docentė socialinių mokslų (edukologijos) daktarė, Vilniaus universitetoSocialinio darbo katedraUniversiteto g. 9/1, LT-01513 VilniusTel. 2 66 76 09Socialinio darbo studijųprogramos magistrantėVilniaus universitetoSocialinio darbo katedraUniversiteto g. 9/1, LT-01513 VilniusTel. 2 66 76 09Straipsnyje, remiantis 15–16 metų merginų apklausos ir skaitomiausių žurnalų vaizdo analize, aptariamas spausdintinės žiniasklaidos poveikis merginų socializacijos procesui. Analizuojamas spaudoje kuriamas idealus moters kūno vaizdinys ir šio vaizdinio įtaka merginų savo kūno suvokimams bei vertinimams. Kuriamo idealaus kūno vaizdinio įtaka atsiskleidžia per merginų internalizuotą moters kūno idealą, kuris išryškėja lyginant objektyvius merginų kūno masės matmenis ir subjektyvius kūno suvokimus bei vertinimus ir stebint jų neatitikimus. Subjektyviai kūnas suvokiamas esąs didesnių apimčių nei yra iš tikrųjų, o tai lemia nepasitenkinimą ir siekimą suliesėti.

Effects of hypoxia-induced intrauterine growth restriction on cardiopulmonary structure and function during adulthood

Intrauterine growth restriction (IUGR), a condition affecting 7-15% of all pregnancies, is associated with an increased mortality rate during adulthood. Several animal models have been developed to study the effects of IUGR during adulthood. However, the in vivo characteristics of these models are still unknown. The main aim of this work was to evaluate, in vivo, the effects of IUGR on cardiopulmonary structure and function during adulthood. Pregnant Sprague Dawley rats were exposed to hypoxic (12% O2) or normoxic (21% O2) environments between day 15 and 21 of pregnancy. Offspring were raised to 4 or 12 months old when a complete in vivo echocardiographic study was performed. In addition, ex vivo morphometry and isolated working heart experiments were performed. At birth, pups exposed to hypoxia had a smaller body weight and larger heart/body weight than controls. At 4 months of age, there were no significant differences between the groups. At 12 months of age, male but not female offspring exposed to prenatal hypoxia had smaller body weights and signs of left ventricular hypertrophy. In addition, both male and females animals exposed to prenatal hypoxia showed in vivo and ex vivo signs of left ventricular diastolic dysfunction and pulmonary hypertension by 12 months of age. Our study demonstrated that hypoxia-induced IUGR is associated with the development of chronic cardiopulmonary dysfunction during ageing. The implication of these findings is the potential usefulness of neonatal diagnosis as a predictor of cardiopulmonary outcomes during adulthood.

Hubungan Ukuran-Ukuran Usus Halus Dengan Berat Badan Broiler

Association of small intestine measurements with body weight in broilersABSTRACT. The main objective of the present study was to investigate the association of small intestine measurements with body weight in broilers. Sixty five weeks old unsex broiler chicks (CP 707) were used. All birds were leg-banded and alloted to 60 cage units and than were fasted for 10 hours but water given. All birds were weighed individually and then sacrificed by neck vein bleeding. Small intestine was dissected individually to determine length and wide. All data were subjected to statistical analysis: correlation and simple linear regression, analysis of variance and t-test. The length of small intestine, duodenum, and jejunum/ileum were each strongly correlated with body weight: r = 0,88; P 0,01; r = 0,71; P 0,01; and r = 0,80, P 0,01 respectively. The wide of duodenum and jejunum/ileum were each closely correlated with body weight: r = 0,90; P 0,01; and r = 0,86; P 0,01 respectively. Results of study indicated that there were strong association between small intestine measurements and body weight in broilers.

Effect of supplementing urea-treated barley straw with lucerne or vetch hays on feed intake, digestibility and growth of Arsi Bale Sheep

The study was conducted at Sinana Agricultural Research Center, Ethiopia to assess the supplementation of graded levels of vetch (Vicia dasycarpa 'lana') and lucerne (Medicago sativa,' Hunter river') hay on feed intake, digestibility and body weight (BW) change of Arsi-Bale sheep fed urea treated barley straw (UTBS). A 7 day- digestibility and a 90 day- feed intake trials were conducted using 28 and 35 sheep, respectively. The experimental design was a randomized complete block design with seven dietary treatments that consisted of feeding UTBS (T1) as the control treatment, UTBS plus 150, 250 and 350 g dry matter (DM) per day of vetch for T2, T3, T4, respectively and UTBS plus 150, 250 and 350 g DM per day of lucerne for T5, T6 and T7, respectively. Intake of UTBS was not affected (P > 0.05) by inclusion of lucerne hay at 25-35% of daily DM intake. The supplements increased daily intake of total DM, organic matter (OM), neutral detergent fiber (NDF), acid detergent fiber (ADF) and metabolizable energy (ME) (P < 0.001) as well as apparent digestibility of DM, OM (P < 0.001), NDF (P < 0.01), ADF, crude protein (CP) (P < 0.05) and daily BW gain (P < 0.001). Supplementation with lucerne than vetch hay promoted higher (P < 0.001) CP and ME intakes and daily BW gain. Feeding with the UTBS without supplementation was enough to meet the maintenance requirements of the sheep and allow small BW gain. The results of the study showed that urea treatment of barley straw in conjunction with supplementation of lucerne or vetch hay could serve as a useful strategy in improving smallholder sheep production in the tropics.

Gene Expression Is Altered in Piglet Small Intestine by Weaning and Dietary Glutamine Supplementation 3

Dietary supplementation of glutamine prevents intestinal dysfunction and atrophy in weanling piglets, but the underlying mechanism(s) are largely unknown. This study was conducted to test the hypothesis that weaning or glutamine may modulate expression of genes that are crucial for intestinal metabolism and function. In Expt. 1, we obtained small intestine from 28-d-old pigs weaned at 21 d of age and from age-matched suckling piglets. In Expt. 2, piglets were weaned at 21 d of age and then had free access to diets supplemented with 1% L-glutamine (wt:wt) or isonitrogenous L-alanine (control). At d 28, we collected small intestine for biochemical and morphological measurements and microarray analysis of gene expression using the Operon Porcine Genome Oligo set. Early weaning resulted in increased (52–346%) expression of genes related to oxidative stress and immune activation but decreased (35–77%) expression of genes related to macronutrient metabolism and cell proliferation in the gut. Dietary glutamine supplementation increased intestinal expression (120–124%) of genes that are necessary for cell growth and removal of oxidants, while reducing (34–75%) expression of genes that promote oxidative stress and immune activation. Functionally, the glutamine treatment enhanced intestinal oxidative-defense capacity (indicated by a 29% increase in glutathione concentration), prevented jejunal atrophy, and promoted small intestine growth (+12%) and body weight gain (+19%) in weaned piglets. These findings reveal coordinate alterations of gene expression in response to weaning and aid in providing molecular mechanisms for the beneficial effect of dietary glutamine supplementation to improve nutrition status in young mammals.

Comparison of Past and Recent Historical Control Data in Relation to Spontaneous Tumors During Carcinogenicity Testing in Fischer 344 Rats

In the present survey, the historical data for spontaneous tumors observed in our laboratory was compared in relation to the time-related changes between recent (2000-2004) and past (1990-1999) samples from Fischer 344 rats used in carcinogenicity studies. In the recent samples, there were statistically increased incidences of islet cell adenomas in males and uterine adenocarcinomas in females. On the other hand, there were decreased incidences of pheochromocytomas, prostatic adenomas, pituitary anterior adenomas, large granular lymphocytic (LGL) leukemias and Leydig cell tumors in males and pituitary anterior adenomas in females. Furthermore, there were decreases in the body weights of both sexes at 58 weeks of age in the recent samples, and this may have been related to the decreases in the incidences of pheochromocytomas, Leydig cell tumors, prostatic adenomas and LGL leukemias. Moreover, the decreased incidence of pheochromocytoma in males revealed a positive correlation with a decreased percentage of severe chronic progressive nephropathy (CPN). On the other hand, there were no distinct factors responsible for increased incidences of tumors observed in the recent samples, suggesting a possible genetic drift. In conclusion, the incidences of spontaneous tumors obtained in our laboratory have been changed with time. Smaller body weights in both sexes and reduction in the number of male cases with severe CPN might be related to the reduced incidence of certain types of tumors in recent animals.

Trade‐offs between melanisation and life‐history traits inHelicoverpa armigera

Abstract1. Previously we established a homozygous melanic strain (JBM) with 16 black pupae spontaneously occurring within a laboratory population (JBW) ofHelicoverpa armigeraand demonstrated that the melanisation is controlled by a single recessive autosomal gene.2. Data obtained indicate that the melanisation is globally expressed in the pupal and adult stages (except for the body hairs of adults) but not in the egg and larval stages. No differences in body colour can be found between the melanic JBM and the wild‐type JBW strains before the metamorphic pupation moult. After pupation, the JBM pupae gradually blacken, whereas the wild‐type JBW pupae gradually turn brown, indicating that the biosynthetic steps leading to brown pigments are shut off in the JBM strain. In the adult stage, wings are darker and hairs on the abdomen and tergum are lighter in the melanic moths than in the wild‐type individuals.3. Life‐table experiments reveal that the melanism is associated with slower development in all life stages, smaller body weight, lower mating rate and fecundity, less mating time, and accordingly, lower net reproduction rate and population trend index.4. Single pair inbreeding and reciprocal crosses show that the mating rate is much lower in the inter‐strain crosses than in the intra‐strain crosses, indicating the presence of mating preference for its own colour morph and the presence to some degree of reproductive isolation between the two colour morphs.

Effect of the Ala12 Allele in the PPARγ-2 Gene on the Relationship Between Birth Weight and Body Composition in Adolescents: The AVENA Study

The intent of this study was to assess whether the effect of birth weight on later body composition is modified by Pro12Pro, Pro12Ala, and Ala12Ala genotypes of the peroxisome proliferator-activated receptor gamma-2 (PPARgamma-2) gene. The PPARgamma-2 gene polymorphism was genotyped in 273 adolescents aged 13-18.5 y, born at term and whose birth weight was known. They were selected from a cross-sectional multicenter study conducted in five Spanish cities in 2000-2002. Body mass index (BMI) was calculated from weight and height measurements, and body composition and fat distribution were estimated from skinfold thickness. A total of 229 subjects (111 males and 118 females) carried the Pro12Pro genotype and 44 (22 males and 22 females) the Pro12Ala and Ala12Ala PPARgamma-2 genotypes. In the Pro12Pro group, birth weight Z score was positively associated with both fat-free mass (FFM) (p < 0.05) and fat mass (FM) (p < 0.05), but these relationships disappeared after controlling for age, gestational age, socioeconomic status (SES), physical activity, Tanner stage, sex, and BMI. In the Ala12 group, birth weight Z score was positively associated with FFM (p < 0.01), and this relationship remained significant after controlling for confounding variables (p < 0.05). Small body weight at birth may program lower FFM in adolescents carrying the Ala12 allele in the PPARgamma-2 gene.

Analysis of polymorphisms in the insulin‐like growth factor 1 receptor (IGF1R) gene from Japanese quail selected for body weight

Insulin-like growth factor 1 receptor (IGF1R) is essential for the signalling of growth. In this study, we performed single nucleotide polymorphism (SNP) detection in the Japanese quail IGF1R coding region and an association study between SNPs and body weight in two lines (SS and LL) selected for large and small body weight. Of 21 SNPs obtained, a SNP at position AB292766:c.2293G>A led to the replacement of a valine with an isoleucine (V765I). The two lines were fixed for alternate alleles, with allele encoding valine fixed in the LL line. A significant effect of the SNP genotype was found on 10-week body weight (P < 0.01) and on 4- to 10-week and 6- to 10-week average daily gain (P < 0.05) in the F(2) family obtained from lines LL and SS. In six populations maintained in Japan or France, the frequency of allele encoding valine was higher than the allele encoding isoleucine.

Ischaemic heart disease is a risk factor for renal failure after heart transplantation

Background The improvement of a long-term outcomes of heart transplantation (HTx) has resulted in a new phenomenon; specifically, the development of renal dysfunction secondary to calcineurin inhibitor toxicity. This study was designed to assess the participation of risk factors in the development of renal dysfunction in HTx. Methods Data from 310 patients undergoing HTx in our center between 1988–1998 with a post-operation survival period for minimum 5 years ( n = 155) were analyzed retrospectively. Study cohort was divided into two groups according to renal function estimated by serum creatinine in the fifth year (Group I n = 72; serum creatinine ≥ 150 μmol/l, Group II: n = 83, serum creatinine < 150 μmol/l). Results We noted that patients with serum creatinine ≥ 150 μmol/l at 5 years post-HTx had renal function significantly worse as early as 1 month ( p < 0.01), and 1 year post-HTx ( p < 0.001). The risk for developing renal dysfunction after HTx was doubled in patients with a history of coronary artery disease (CAD), and 2.5 times higher in those with small body weight gain. End stage renal disease developed in 16 patients (10.3%) and renal transplantation was performed in 13 (8.4%) of them. Conclusion Our data documented that a history of CAD and limited weight gain is a major risk factor for development of renal dysfunction after HTx. Aggressive modification of risk factors for CAD may reduce the occurrence of this complication.

A two generation reproductive toxicity study with curcumin, turmeric yellow, in Wistar rats

The reproductive toxicity of curcumin, turmeric yellow, in Wistar rats was studied in order to generate additional relevant toxicity information for the use of curcumin in humans by oral administration. The two generation reproduction study was designed and conducted in accordance with OECD Guideline No. 416 [OECD, 1983. Guidelines for Testing of Chemicals, Guideline No. 416. Two Generation Reproduction Toxicity Study, adopted on 26th May 1983] and in compliance with Good Laboratory Practices (OECD, 1997 Principles of Good Laboratory Practice for the Testing of Chemicals. OECD, C(97)186/Final). The curcumin, mixed in the experimental diet at the concentrations of 1500, 3000 and 10,000 ppm was fed to three groups of rats, i.e., low, mid and high dose groups, and studied for two successive generations. A concurrent control group received experimental diet without the curcumin mixture. There were no treatment related adverse toxicological effects in the parental animals. No gross or microscopic changes were observed in any of the organs. None of the reproductive parameters were affected and there were no effects on the offspring other than a small reduction in pre-weaning body weight gain of the F2 pups at the highest dose level. It was concluded that the no observed adverse effect level (NOAEL) for reproductive toxicity of curcumin, fed in the diet for two successive generations to rats in this study was 10,000 ppm, which is equivalent to 847 and 959 mg/kg bodyweight (bw) per day for male rats and 1043 and 1076 for females for F0 and F1 generations, respectively. This study was the final toxicology study on curcumin reviewed by the Joint FAO/WHO Expert Committee on Food Additives (JECFA) at the 61st Meeting, 2003. The JECFA group considered that the small body weight reduction in the F2 pups of the highest dose group prevented this from being regarded as a no adverse effect level, and so allocated an ADI for curcumin of 0–3 mg/kg bw based on the intake of 250–320 mg/kg bw in the mid-dose group as the NOEL.

Effects of Postnatal Exposure to Methamphetamine on the Development of the Rat Retina

Since the development of different cell types in the retina occurs at different rates, it is possible that exposure to an exogenous substance may produce effects during one time period, but not during another. This study aims to analyze the effects of methamphetamine (METH) in the growth pattern of an experimental model as well as neurochemical and immunohistochemical parameters of the dopaminergic system of the rat retina. The three development stages chosen in this study are key markers in rat eye development. Rats were given 15 mg/kg body weight per day of METH as subcutaneous injections in 0.9% saline (3 mL/kg weight/day) from the day after birth PND 1 to PND 6, PND 13, and PND 29. Each daily dose was split into two. The control group was injected subcutaneously with saline. Both the schedule and volume for injecting saline in the control group were the same as for the METH-treated group. There were no significant differences in the total number of offspring per litter among treatment groups. All offspring had similar body weight at birth. Analysis of body weight on PND 1, showed that animals treated with METH had similar body weights to control-treated animals and females had smaller weights than males. For growth evolution, only litters with a sex ratio of four males and four females were used. Animals treated with METH had smaller body weights than the control-treated animals for all ages studied (PND 7, 14, and 30). Within the control group at PND 30, a significant difference was found in the body weight of females, which was lower when compared with males. For the postnatal model, 7 deaths occurred for the METH-exposed group. No deaths occurred in the control group in a total of 16 saline-injected litters comprising 186 pups. Although the levels of dopamine (DA) was within normal values for the postnatally exposed METH group when compared with its respective control group at PND 7 and 30, at PND 14 this was not the case: in this experimental group, the level of DA was lower than in the control group for both females and males. Support for this result was not evident from the TH immunoreactivity studies, probably because the methodology lacks the sensitivity to distinguish any mild effects, such as that observed in the postnatal model at PND 14. The level of the DA metabolite 3, 4-dihydroxyphenylacetic acid (DOPAC) remained unaffected at all ages studied, for both females and males. The results obtained in this study support the view that, during the critical periods in which the catecholamines can influence the development of neurones, METH transiently affects the pattern of the dopaminergic system in the developing retina.

Effects of Prenatal Exposure to Methamphetamine on the Development of the Rat Retina

In recent years there has been growing use of methamphetamine (METH) by pregnant women, resulting in an increasing number of children exposed prenatally to this drug of abuse. METH is known to be potentially neurotoxic to human adults, but there is minimal information with respect to the consequences of such exposure to the fetus. The purpose of this study was to ascertain external parameters of animal development, as well as neurochemical and immunohistochemical alterations at three key points of retinal development (postnatal day [PND] 7, 14, and 30). Rats of the Wistar strain were used in this experimental model. Pregnant females received a dose of 5 mg/kg body weight per day of METH-HCl in 0.9% saline, from gestational day (GD) 8 to 22. The control group to be used was pair fed and saline injected. Litters were randomly culled at PND 1 to 8 pups. Analysis of maternal body weight gain during pregnancy showed that females treated with METH had lower body weights than control-treated females. The body weight on PND 1, showed that animals treated with METH prenatally had smaller body weights than the control-treated animals and also that females weighed less than males. Prenatal exposure to METH did not alter the retinal levels of 3,4-dihydroxyphenylacetic acid (DOPAC) in the male group and the level of dopamine (DA) in both female and male groups when compared with their respective pair fed control groups during the first month of life. Correlating with the neurochemical data, no obvious changes on the localization of TH immunoreactivity in the rat retina at PND 7, 14, and 30 could be detected between control and METH-treated animals. Thus, exposure to METH disrupted this pattern in a gender-dependent manner. These data confirm previous observation that developing rats are protected against the adult type of METH-induced neurotoxicity. Therefore, conventional markers used for adult animals appear to be unsatisfactory to demarcate boundaries of the PND 1 to 30 critical periods.

Anatomic study of small intestinal vessel in piglet small intestine transplantation

To study the anatomy of the small intestine,and investigate the optimal selection of donors,recipients,and their small intestine vessels in piglet small intestine transplantation. The weight and length of 30 piglets were measured. Angiography and pigments perfusion were used to observe the main vessels of the small intestine,and the length of the small intestine,and the external diameter of the main vessels of the small intestine were measured in vivo and ex vivo. The length of the small intestine was 11.5 times as long as the body length, and its weight accounted for 2.3% of the body weight. The outer diameters of abdominal aorta (AT), mesenteric anterior artery (MAA) and its 5(th)-6(th) branches in vivo and ex vitro were 4.3/4.6mm, 2.5/2.7mm and 1.9/2.2mm respectively. The total number of MAA's branches was 6-8 in general and its 5(th)-6(th) branches were the longest [(20.0 +/- 7.0) mm, (22.0 +/- 8.2) mm]. The outer diameter of mesenterial anterior vein (MAV) was 1-2 mm wider than that of MAA. AT, MAA and its 5(th)-6(th) branches are the preferable vessels for small intestine transplantation. In segmental small intestine transplantation, the length of the small intestine and body weight can be used to primarily select the suitable animals.

Effect of Ascaridia galli infection on histopathologic description, size of small intestines villi surface and body weight change in starters

Nematode Ascaridia galli is an important parasitic disease in poultry and is responsible for considerable economic losses in retarded growth and lowered egg production. The effects of A. galli infection based on histopathologic description, size of small intestines villi surface and body weight change in starters was investigated. One hundred and thirty five day old chicks (DOC) were divided into three groups for three levels of infection dose rate (0,800 and 8000 infective eggs) with 3 replications of 45 DOC each. Infections were carried out every week respectively from week 2 th until week 5 th . Results showed that the infection of A. galli caused degeneration and necroses in villi ephitelial cells and crypts of small intestine and infiltration of leucocytes. In the heavy infection group some epithelial cells were replaced by fibrocytes. A. galli infection decreased daily body weight gain of starter lower (5.5% in light and 13.4% in heavy dosage infection) compared to that of the non infected group. After six weeks of heavy infection the size of small intestine villi surface was decreasing to 20.0%, while the daily body weight gain was decreasing to 12.3% compared to that of the non infection group. Key words : Ascaridia galli , Starter, Productivity

Effect of Maternal Passive Autoimmunization against Myostatin on Growth Performance in Chickens

Myostatin is a negative regulator of skeletal muscle growth and a loss of functional myostatin protein increases muscle hypertrophy and hyperplasia in cattle. The present study was conducted to investigate whether maternal passive immunization against myostatin would improve growth performance in chickens. A complete broiler myostatin cDNA was cloned and it was expressed into two transcripts as 1,128 bp and 985 bp by alternative splicing. A conjugated mature myostatin (350 bp) was used to induce autoimmunization and maternal passively immunized chickens was used for the experiment. It was confirmed that there was a maternal passive immunization against myostatin at zero weeks of age, but its effect was reduced by 6 weeks of age. The auto-immunized groups showed smaller body weights than those of control group during the growing period and the difference was getting bigger with time until 6 weeks of age. These results suggest that passive autoimmunization against myostatin used in this study is not potent enough to stimulate growth performance in chickens. (Asian-Aust. J. Anim. Sci. 2005. Vol 18, No. 7 : 1017-1021)

Youth Football: Heat Stress and Injury Risk

Michael F. Bergeron, Ph.D., FACSM (Co-Chair)Douglas B. McKeag, M.D., FACSM (Co-Chair)Douglas J. Casa, Ph.D., ATC, FACSMPriscilla M. Clarkson, Ph.D., FACSMRandall W. Dick, FACSME. Randy Eichner, M.D., FACSMCraig A. Horswill, Ph.D., FACSMAnthony C. Luke, M.D., MPHFrederick Mueller, Ph.D., FACSMThayne A. Munce, Ph.D.William O. Roberts, M.D., FACSMThomas W. Rowland, M.D., FACSM

Prenatal alcohol exposure alters the size, but not the pattern, of the whisker representation in neonatal rat barrel cortex

Maternal alcohol exposure results in a variety of neurodevelopmental abnormalities that include cognitive and sensorimotor dysfunctions that often persist into adulthood. Many reports of central nervous system disturbances associated within a clinical diagnosis of fetal alcohol syndrome point toward disturbances in central information processing. In this study, we used the rat barrel field cortex as a model system to examine the effects of prenatal alcohol exposure (PAE) on the organization and size of the large whisker representation in layer IV of the posteromedial barrel subfield (PMBSF) in somatosensory cortex. Pregnant rats (Sprague-Dawley) were intragastrically gavaged daily with alcohol doses (6 gm/kg body weight) from gestational day 1 to day 20 in a chronic binge pattern which produced blood alcohol levels ranging between 260 mg/dl and 324 mg/dl. Chow-fed (CF), pair-fed (PF), and cross-foster (XF) groups served as normal, nutritionally matched, and maternal controls, respectively, for the ethanol-exposed (EtOH) treatment group. All pups were examined on gestational day 32 corresponding approximately to postnatal day 9. EtOH and control group pups were weighed, anesthetized, and perfused. Brains were removed and weighed, with and without cerebellum and olfactory bulbs, and the neocortex was removed and weighed. Cortices were then flattened, sectioned tangentially, and stained with a metabolic marker-cytochrome oxidase-to reveal the barrel field. A subset of 27 cortical barrels, associated with the representation of the large whisker pad, was selected to examine in detail. The major results were: (i) the total barrel field area comprising the PMBSF was significantly reduced in EtOH (by 17%) and XF (by 16%) pups compared with CF pups, (ii) the sizes of individual barrels within the PMBSF were also significantly reduced in EtOH (16%) and XF (18%) pups, (iii) the septal region between barrels was also significantly reduced in EtOH (18%) and XF (12%) pups, (iv) anteriorly located barrels underwent greater reduction in size relative to the posteriorly located barrels, (v) body weights were also significantly reduced in EtOH (21%) and XF (27%) pups, (vi) total brain weight [with and without (forebrain) cerebellum/olfactory bulbs] and cortical weights were also significantly reduced in EtOH (total brain weight 15%, forebrain weight 16%, cortical weight 15%) and XF (18%, 19%, 20%) pups, and in contrast (vi) neither the overall barrel field pattern nor the pattern of individual barrels in the PMBSF was altered. These findings suggest that PAE reduces body and brain weight as well as the central cortical representation of the whisker pad, while leaving the overall barrel field pattern unperturbed. While these results might appear to support a miniaturization hypothesis (smaller PMBSF, smaller brain, smaller body weight), PAE also shows regional vulnerability within the PMBSF whereby anteriorly located barrels are most affected.

Development and resolution of experimental colitis in mice with targeted deletion of dipeptidyl peptidase IV

Glucagon-like peptide-2 (GLP-2) is a potent intestinotrophic growth factor that enhances repair of damaged intestinal tissue. However, its bioactivity is limited by dipeptidyl peptidase IV (DPIV)-mediated degradation. We hypothesized that DPIV(-/-) mice would display an increased resistance to, and an enhanced recovery from, dextran sulfate sodium (DSS)-induced colitis compared to DPIV(+/+) mice. DPIV(+/+) and DPIV(-/-) mice consumed 2% DSS for 6 days, followed by a 15 day recovery period. Mice were killed at days 0, 3, 6, 9, 14, and 21 (n = 6-8) and the small intestine and colon removed for histological assessment of villus height, crypt depth, and crypt area. The epithelial cell proliferative labeling index was determined by proliferating cell nuclear antigen (PCNA) immunostaining. Small intestine, colon, and total body weight did not differ between DPIV(+/+) and DPIV(-/-) mice. Distal colon crypt depth did not differ significantly between DPIV(+/+) and DPIV(-/-) mice during the development of DSS-colitis or during the recovery phase. Similarly no significant effects were apparent on distal colon crypt area or PCNA labeling index between DPIV(+/+) and DPIV(-/-) during the development of and recovery from DSS-colitis. However, DPIV(-/-) mice still possessed significant levels of plasma DPIV-like activity. We conclude that loss of DPIV activity does not increase resistance to experimental colitis and hypothesize that other DPIV family members may also be involved in the cleavage of GLP-2.