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Biomedical subjects

J S Sim

Publications and source records attributed to J S Sim.

At least 19 recordsLinked to original sources
PubMed2004

Maternal dietary ratio of linoleic acid to alpha-linolenic acid affects the passive immunity of hatching chicks.

The objective of the current study was to examine the effect of dietary ratio of linoleic acid (LA) to alpha-linolenic acid (LNA) on the humoral immune response in laying hens and further on the passive immunity of their progeny. Thirty-two Single Comb White Leghorn laying hens, 24 wk of age, were randomly assigned to 1 of 4 diets that had LA-to-LNA ratios of 0.8, 5.4, 12.5, and 27.7, respectively, by changing the proportions of sunflower and linseed oils. After 5 wk on the experimental diets, hens were immunized intramuscularly with 1 mg of BSA, followed by 2 boosters 2 and 6 wk later. Serum and egg yolk were obtained weekly from 0 to 6 wk following the first injection of BSA. One week after the second booster, fertile eggs were collected and incubated. The sera of 11-d-old embryos and hatchlings were collected. All serum samples were stored at -20 degrees C before analysis. The results showed that dietary LA-to-LNA ratio had no effect on the total IgG and BSA-specific antibody IgG concentrations in the serum or egg yolk of laying hens. Hatchlings from hens fed the diet containing the LA-to-LNA ratio of 12.4 showed lower (P < 0.05) BSA-specific IgG titer in the serum than those from hens given the diet containing LA-to-LNA ratio of 0.8. A lower (P < 0.05) total IgG concentration was observed in hatchlings from hens fed the diet containing LA-to-LNA ratio of 12.4 compared with those from hens fed diets containing 0.8 and 5.4 of LA-to-LNA ratios. It is suggested that the dietary ratio of LA to LNA has no effect on laying hen humoral response but affects the passive immunity of hatching chicks.

Animal Nutritional Physiological Phenomena↗
PubMed2003

Maternal dietary FA modulate the long-chain n-3 PUFA status of chick cardiac tissue.

The effect that egg yolk or maternal n-3 FA have on the cardiac tissue long-chain n-3 FA status of chicks during growth was investigated. Eggs with low, medium, and high levels of n-3 PUFA were obtained by feeding breeder hens a wheat/soybean meal-based diet containing 5% sunflower oil (Low n-3), 2.5% sunflower oil plus 2.5% fish oil (Medium n-3), or 5% fish oil (High n-3). The chicks hatched from Low, Medium, and High n-3 eggs were fed a diet containing 18:3n-3, but devoid of long-chain n-3 FA. The FA composition of cardiac tissue was determined on days 0, 14, 28, and 42. At day 0, the cardiac FA reflected maternal diet. With time, the level of all the long-chain n-3 FA decreased compared with day 0, and this was true especially by day 14. These data show that dietary 18:3n-3 fed to the chicks did not sustain high levels of EPA and DHA in cardiac tissue, despite the high content of long-chain n-3 FA in the maternal diet. At days 0 and 14, the chicks hatched from High and Medium n-3 eggs had higher 20:5n-3, 22:5n-3, and 22:6n-3 contents with a concomitant reduction in 20:4n-6 in the cardiac tissue compared with the Low n-3 egg group. Cardiac tissue of birds hatched from Medium n-3 eggs retained higher levels of 20:5n-3 up to day 42 of growth when compared with other treatments (P < 0.05). None of the treatments was effective in maintaining DHA levels after day 14 of growth.

Animals↗
PubMed2003

Maternal and posthatch dietary polyunsaturated fatty acids alter tissue tocopherol status of chicks.

The effects of maternal and starter diet polyunsaturated fatty acid (PUFA) composition on the tocopherol (TOC) status of posthatch chicks were investigated. Fertile eggs enriched with long chain n-3, 18:3 n-3 or 18:2 n-6 PUFA were incubated. The eggs were collected from hens fed diets containing 3.5% menhaden oil (MO), linseed oil (LO), or sunflower oil (SO) and a vitamin E mix containing 400 microg/g total TOC. Posthatch chicks from MO, LO, or SO were fed starter diets containing 3.5% MO, LO, or SO along with vitamin E mix containing 48 microg/g total TOC. Tissues (liver, blood, brain) were collected on d 0 (day of hatch), 7, 14, and 21 posthatch. On d 0, MO chicks had the lowest liver and plasma TOC (P < 0.05). A rapid depletion of liver and plasma TOC was observed on d 7 and 14 posthatch (P < 0.001) and was lower in MO chicks (P < 0.05) than LO. When compared with d 0, a 98% decrease of tocopherol on d 7 was observed for chicks from all treatments. No changes due to age or diet PUFA was observed in the brain TOC status. Data showed that maternal and starter diet PUFA could alter the TOC status of chicks in early life.

Animal Feed↗
PubMed2003

Maternal diet with diverse omega-6/omega-3 ratio affects the brain docosahexaenoic acid content of growing chickens.

Eggs with diverse omega-6/omega-3 ratio produced by feeding breeder hens a wheat-soybean meal-basal diet containing 5% (wt/wt) sunflower oil (H(omega)6), 5% fish oil (H(omega)3) or 2.5% sunflower oil plus 2.5% fish oil (M(omega)3omega6) were incubated. The hatched chicks were fed a docosahexaenoic acid (DHA)-deficient diet up to 6 weeks of age. The fatty acid composition of chick brain was determined on 0, 2, 4 and 6 weeks and brain weight was taken on day 0 and day 42. The omega-6/omega-3 ratios were 37.12, 4.21 and 0.98 for the maternal diet; 28.36, 2.83 and 0.89 for the egg yolk; 1.94, 0.48 and 0.18 for hatched chick brain (p < 0.05). At 2 weeks of age, the omega-6/omega-3 ratios were 1.88, 0.81 and 0.60 for chicks hatched from hens fed H(omega)6, M(omega)3omega6 and H(omega)3 diets, respectively. The brain DHA contents at 0 and 2 weeks of age were Homega3 > M(omega)3omega6 < H(omega)6 (p < 0.05) and at 4 and 6 weeks of age H(omega)3 = M(omega)3omega6 > H(omega)6. Dietary C18:3omega3 in the starter and finisher diet did not increase brain DHA (p > 0.05). The significant increase in the content of C22:5omega3 at 6 weeks of age in group 1 birds with a concomitant reduction in DHA suggests a weak delta-4 desaturation but an effective delta-6 and delta-5 desaturation similar to human infants. Considering the role of DHA in early brain development and growth, the maternal supply of DHA during growth might be of importance when fed a DHA-deficient neonatal diet.

Aging↗
PubMed2002

Maternal dietary N-3 fatty acids alter the spleen fatty acid composition and bovine serum albumin-induced wing web swelling in broilers.

Effects of maternal dietary polyunsaturated fatty acids (PUFA) on the spleen fatty acid composition and BSA-induced wing web swellings were investigated in broilers. One hundred twenty broiler breeder hens 26 wk of age were randomly assigned to diets containing mainly wheat, corn, soy meal, barley, oat and 5% (wt/wt) added sunflower oil, fish oil, or a mix of sunflower and fish oils (1:1). After 2 wk on the experimental diets, birds were inseminated, eggs were collected and incubated. Progeny chicks were then fed identical diets for 6 wk. The maternal dietary oils affected (P < 0.05) n-6 and n-3 PUFA in the spleens of hatching chicks. After 2 wk, n-6 PUFA did not differ among the groups; n-3 PUFA, docosapentaenoic, and docosahexaenoic (DHA) acids were higher (P < 0.05) in the spleens of broilers from hens fed 2.5 or 5% fish oil. After 4 wk, broilers from hens fed 5% fish oil still had higher levels of DHA (P < 0.05) in their spleens than those from hens fed 5% sunflower oil. The BSA-induced wing web swelling response was suppressed (P < 0.05) by n-3 PUFA in breeder hens. Broilers from hens fed high levels of n-3 PUFA had lower (P < 0.05) wing web swelling reactions to BSA at 2 wk (2.5% fish oil) and 4 wk (2.5 and 5% fish oil). In conclusion, n-3 PUFA in breeder hen diets suppressed the BSA-induced wing web swellings of the hens, increased the spleen n-3 fatty acids (especially DHA), and decreased BSA-induced wing web swellings of progeny up to 4 wk of age.

Analysis of Variance↗
PubMed2002

In vitro studies of chicken egg yolk antibody (IgY) against Salmonella enteritidis and Salmonella typhimurium.

Chicken egg yolk antibody (IgY) raised against Salmonella enteritidis or Salmonella typhimurium was found in highly specific activity levels by ELISA. S. enteritidis- and S. typhimurium-specific IgY powder, prepared by freeze-drying the egg yolk water-soluble fraction, contained 15.5 and 10.0% of specific IgY, respectively. Anti-S. enteritidis IgY cross-reacted 55.3% with S. typhimurium. The cross-reactivity of anti-S. typhimurium IgY with S. enteritidis was 42.4%. Salmonella-specific IgY was demonstrated to inhibit Salmonella growth in liquid medium. The growth rate of S. enteritidis incubated with S. enteritidis-specific IgY was fourfold less than that of the control group during a 4-to-6-h incubation. Cell counts of S. typhimurium incubated with S. typhimurium-specific IgY were reduced by 1.6 log cfu/mL in comparison to that of the control group after 6 h of incubation. The specific binding activity of IgY was further evaluated by using immunofluorescence and immunoelectron microscopy. It was found that Salmonella-specific IgY could bind to the antigens expressed on the Salmonella surface, resulting in structural alterations of the bacterial surface.

Animals↗
PubMed2001

Dietary palm oil alters the lipid stability of polyunsaturated fatty acid-modified poultry products.

Laying hens were fed a high polyunsaturated fatty acid (PUFA) diet with three levels [low (LPO, 0%), medium (MPO, 1.5%), and high (HPO, 3.5%)] of palm oil (PO) or a PUFA diet with tocopherol mix (control). Flax and fish oils were used as PUFA sources in all of the diets. Inclusion of tocopherols resulted in a lower (P < 0.05) thiobarbituric acid reactive substances (TBARS) in the control eggs in white and dark meats. Among the PO treatments, eggs from HPO diet had the lowest TBARS (P < 0.05). A higher (P < 0.05) TBARS was observed for eggs, meat, and liver from hens on the LPO diet. No difference was observed between the TBARS of LPO and MPO dark meat. The C22:6 n-3 fatty acid was lower (P < 0.05) in MPO and HPO eggs and the HPO white meat.

Adipose Tissue↗
PubMed2001

Maternal dietary alpha-linolenic acid (18:3n-3) alters n-3 polyunsaturated fatty acid metabolism and liver enzyme activity in hatched chicks.

We investigated the effects of dietary alpha-linolenic acid (LNA; 18:3n-3) of laying hens on the fatty acid composition of liver microsomes and activity of delta-6 desaturase in hatched chicks. Laying hens were fed wheat-soybean meal-based diets with (Flax) or without ground flax (control). At Day 21 of feeding, fertile eggs were collected and incubated. On the day of hatching, chicks (n = 6) were killed, and liver microsomes were isolated and assayed for delta-6 desaturase enzyme activity. The total n-3 fatty acids in the Flax eggs was 13.0% compared with 2.3% (P < 0.001) in the control group. LNA was the major n-3 fatty acid in the Flax eggs and constituted 10%. The long-chain n-3 polyunsaturated fatty acids (PUFA) (20:5n-3, 22:5n-3, and 22:6n-3) constituted 3.1% in Flax eggs compared with 1.5% in control eggs. Docosahexaenoic acid (22:6n-3) composed 2.1 and 1.2% in Flax and control eggs (P < 0.05), respectively. The liver microsomes of Flax chicks incorporated higher 18:3n-3, 20:5n-3, and 22:5n-3 (P < 0.05) with a concomitant reduction in 20:4n-6, 22:4n-6, and 22:5n-6 compared with control chicks (P < 0.05). The delta-6 desaturase activities in Flax and control groups were 49.4 and 82.8 pmol/min per mg of protein, respectively (P < 0.05). These results demonstrate the role of maternal and yolk n-3 fatty acids in modulating the activity of rate-limiting enzymes for PUFA synthesis in hatched chicks.

Animals↗
PubMed2000

Dietary polyunsaturated fatty acids alter lymphocyte subset proportion and proliferation, serum immunoglobulin G concentration, and immune tissue development in chicks.

The effects of fat source on immune response of the offspring of the Single Comb White Leghorn laying hens were investigated. The laying hens were fed for 6 wk with a wheat-soybean meal basal diet with added sunflower oil (SO), animal oil (AO), linseed oil (LO), or menhaden fish oil (FO) at 5% (wt/wt). Upon hatching, the chicks (30/group) were given the same types of diets for 8 wk. The dietary SO, AO, and LO provided different n-6 to n-3 polyunsaturated fatty acids (PUFA) ratios. The FO and LO had ratios of n-6 to n-3 PUFA that were close but had different components of n-3 PUFA. The results demonstrated that the chicks fed LO or FO had significantly lower (P < 0.05) splenocyte proliferative response to ConA than the chicks fed SO or AO at either 4 wk or 8 wk of age, with a stronger (P < 0.05) suppressive effect produced by LO at 4 wk. A significantly lower (P < 0.05) splenocyte response to PWM was produced by the chicks fed AO, LO, and FO compared with the chicks fed SO at 8 wk. The thymus lymphocyte proliferation in response to ConA at 4 wk was lower (P < 0.05) in the chicks fed AO, LO, and FO than in the chicks fed SO. Both LO and FO elevated (P < 0.05) the proportion of IgM+ lymphocytes in spleen, but only FO increased (P < 0.05) the serum IgG concentration. The LO elevated (P < 0.05) the percentage of CD8+ T-lymphocytes but not the ratio of CD4+ to CD8+ cells (P > 0.05) in spleen. Growths of thymus, spleen, and bursa were impacted significantly (P < 0.05) by the amount of dietary PUFA, the ratio of n-6 to n-3 fatty acids, and n-3 PUFA components.

Animals↗
PubMed2000

Fatty acid determination in chicken egg yolk: a comparison of different methods.

Four different methods (direct-methylation, saponification, chloroform-methanol extraction, and postextraction saponification) were compared to determine the fatty acids in egg yolk. About 50 mg of pooled egg yolk samples, with C23:0 as an internal standard, was used for all assays. No difference (P > 0.05) was observed among the four methods for C17:0, C18:0, C18:1, C20:1, C18:2n-6, and C22:6n-3 content of egg yolk. Direct saponification resulted in a lower (P < 0.05) content of C14:0, C16:1, C18:3n-3, and C20:4n-6. Fatty acids at less than 0.5%, such as C15:0 and C14:1, were not detectable in the direct saponification method. The total saturated, monounsaturated, or polyunsaturated fatty acids did not differ (P > 0.05) among the four methods. Direct methylation of egg yolk resulted in lower variability than other methods and is fast and economic for determining egg fatty acid composition.

Animals↗
PubMed1999

Definitive diagnosis of intestinal volvulus in utero.

Midgut volvulus with or without intestinal malrotation can occur in fetal life. Several reports have described congenital midgut volvulus showing non-specific sonographic findings of intestinal obstruction and perforation in utero. None of the previously reported cases, however, were definitively diagnosed as midgut volvulus by fetal sonography. We report two cases both exhibiting the sonographic 'whirlpool' sign, in utero. Color Doppler interrogation provided a clue to the viability of the involved intestinal segment.

Adult↗
PubMed1999

Differentiation of small hyperechoic renal cell carcinoma from angiomyolipoma: computer-aided tissue echo quantification.

To assess the value of computer-aided tissue echo quantification in differentiating small hyperechoic renal cell carcinomas from angiomyolipomas, we studied ultrasonographic images of 15 renal cell carcinomas and 20 angiomyolipomas. After digitizing the images, we measured the absolute gray scale values of the renal cortex, central echo complex, and mass. The relative gray scale value (%) of the mass was calculated by setting the gray scale value of the cortex as 0% and the central echo complex as 100%. The relative gray scale value of renal cell carcinomas was in the range of 12 to 73% (mean, 28%), whereas that of angiomyolipomas was 30 to 204% (mean, 130%). The differentiation between small hyperechoic renal cell carcinomas and angiomyolipomas can be facilitated by computer-aided tissue echo quantification.

Adult↗
PubMed1998

Isolation, characterization and localization of glycosaminoglycans in growing antlers of wapiti (Cervus elaphus).

Glycosaminoglycans were isolated from the four sections (tip, upper, middle and base) of the main beam of growing antlers of wapiti (Cervus elaphus) by papain digestion and DEAE-Sephacel chromatography. Chondroitin sulfate was the major glycosaminoglycan in each section of antler accounting for, on average, 88% of the total uronic acid. The yield of chondroitin sulfate liberated from the tissue was approximately 6-fold greater in the cartilaginous (tip and upper) sections than in the bony (middle and base) sections. This was consistent with the higher intensity of glycosaminoglycan staining with either Alcian Blue or Safranin-O. The majority (average 88%) of chondroitin sulfate was precipitated with 40 and 50% ethanol. The average molecular size of chondroitin sulfate determined by gel chromatography on Sephacryl S-300 tended to be greater in the 40% ethanol than in the 50% ethanol fraction. In either fraction, the molecular size of chondroitin sulfate was smaller in cartilaginous tissues than in osseous tissues of growing antler. In addition to chondroitin sulfate, the antler contained small amounts of hyaluronic acid, dermatan sulfate and keratan sulfate. The immunohistochemical study showed wide distribution of chondroitin sulfate, decorin, and keratan sulfate throughout the antler. On the other hand, keratan sulfate was more prominent in the cartilaginous sections than in the bony sections where the anti-keratan sulfate monoclonal antibody staining was seen in the osteoid tissue only.

Animals↗
PubMed1998

Isolation and characterization of proteoglycans from growing antlers of wapiti (Cervus elaphus).

Proteoglycans were extracted with 4 M guanidine-HCl from the zone of maturing chondrocytes, the site of endochondral ossification of growing antlers of wapiti (Cervus elaphus). Proteoglycans were isolated by DEAE-Sephacel chromatography and separated by Sepharose CL-4B chromatography into three fractions. Fraction I contained a high molecular mass (> 1000 kDa) chondroitin sulfate proteoglycan capable of interacting with hyaluronic acid. Its amino acid composition resembled that of the cartilage proteoglycan, aggrecan. Fraction II contained proteoglycans with intermediate molecular weight which were recognized by monoclonal antibodies specific to chondroitin sulfate and keratan sulfate. Fraction III contained a low molecular mass (< 160 kDa) proteoglycan, decorin, with a glucuronate-rich glycosaminoglycan chain.

Amino Acids↗
PubMed1998

Effects of egg and yolk weights on yolk antibody (IgY) production in laying chickens.

Twenty 35-wk-old chickens, including 10 Single Comb White Leghorn (SCWL) and 10 Rhode Island Red (RIR) hens, were used to examine the effects of egg and yolk weights on egg yolk antibody (IgY) production in the two strains of chickens immunized with BSA. The SCWL chickens had a greater (P < 0.01) percentage hen-day production and greater egg and yolk weights than did the RIR chickens. However, the anti-BSA antibody activities determined by ELISA in the serum and the egg yolk were similar (P > 0.05) between the SCWL and RIR chickens. Similarities between the two strains of hens were also observed in protein and total IgY contents (expressed as the percentage of wet weight of yolk) and the percentage of BSA-specific antibody in the total IgY. It was concluded that both the SCWL and RIR chickens immunized with BSA can produce egg yolk IgY containing similar proportions of BSA-specific antibodies. Therefore, the egg yolk weight and the percentage hen-day production, both of which are greater in the SCWL hens, are considered to be important factors for the efficient production of IgY.

Animals↗