Mucosa-associated microbiota from different regions of the gastrointestinal (GI) tract of adult broilers was studied by analysis of 16S rRNA gene sequences. The microbiota mainly comprised Gram-positive bacteria along the GI tract. Fifty-one operational taxonomic units (OTUs) (from 98 clones) were detected in the ceca, as compared with 13 OTUs (from 49 clones) in the crops, 11 OTUs (from 51 clones) in the gizzard, 14 OTUs (from 52 clones) in the duodenum, 12 OTUs (from 50 clones) in the jejunum and nine OTUs (from 50 clones) in the ileum. Ceca were dominantly occupied by clostridia-related sequences (40%) with other abundant sequences being related to Faecalibacterium prausnitzii (14%), Escherichia coli (11%), lactobacilli (7%) and Ruminococcus (6%). Lactobacilli were predominant in the upper GI tract and had the highest diversity in the crop. Both Lactobacillus aviarius and Lactobacillus salivarius were the predominant species among lactobacilli. Candidatus division Arthromitus was also abundant in the jejunum and ileum.

Gieling RG, Wallace K, Han Y-P. Interleukin-1 participates in the progression from liver injury to fibrosis.

Two chick bioassays with chemically defined amino acid (AA) diets were conducted to compare three different AA profiles: the NRC 1984 and NRC 1994 requirement profile and the Illinois Ideal Chick Protein (IICP) AA profile. The two battery studies involved chicks during the 2nd and 3rd wk after hatching. In Assay 1, indispensable AA (including glycine and proline) were ratioed to lysine according to requirement ratios present in NRC 1984 and NRC 1994, with digestible lysine set at either deficient (.80% of diet) or superadequate (1.12% of diet) levels for the purified diet in question. All diets were kept isonitrogenous (2.83% N) by varying the level of L-glutamic acid. At .80% lysine, chicks fed the NRC 1994 AA profile gained 60% faster (P < .01) than those fed the NRC 1984 AA profile. With excess digestible lysine (1.12%) and all other indispensable AA increased proportionately, chicks fed NRC 1994 still out-gained those fed NRC 1984 by 13% (P < .05). Ratios of AA (with respect to lysine) in NRC 1994 were equal to or higher than those in IICP, except for histidine. This was due to a lower estimated lysine requirement in NRC 1994 than that used for IICP. When NRC 1994 was compared with IICP in a chick bioassay involving isonitrogenous diets (2.36% N) and digestible lysine set at a deficient level of .90%, weight gain and feed efficiency were similar between diets. This result suggested that most of the indispensable AA in the NRC 1994 AA profile were too high relative to lysine, probably because lysine, the reference AA, was too low relative to the other AA.(ABSTRACT TRUNCATED AT 250 WORDS)

Both cytokines and matrix metalloproteinases (MMPs) are active during physiologic and pathologic processes such as cancer metastasis and wound repair. We have systematically studied cytokine-mediated MMP regulation. Cytokine-mediated proteinase induction and activation were initially investigated in organ-cultured human skin followed by determination of underlying cellular and molecular mechanisms using isolated skin cells. In this report we demonstrate that tumor necrosis factor-␣ (TNF-␣) and transforming growth factor-␤ (TGF-␤) synergistically induce pro-MMP-9 in human skin as well as isolated dermal fibroblasts and epidermal keratinocytes. Furthermore, TNF-␣ promotes proteolytic activation of pro-MMP-9 by conversion of the 92-kDa pro-MMP-9 to the 82-kDa active enzyme. This activation occurred only in skin organ culture and not by either isolated fibroblasts or keratinocyte, although the pro-MMP-9 activation could be measured in a cellfree system derived from TNF-␣-activated skin. The cytokine-mediated induction of pro-MMP-9 in dermal fibroblasts was evident by increased mRNA. At the transcription level, we examined the cytokine-mediated transactivation of the 5-region promoter of the human MMP-9 in dermal fibroblasts. The results demonstrated that TNF-␣ and TGF-␤ could independently stimulate the 5-flanking 670-base pair promoter. A TGF-␤-response element (؊474) and an NF-B-binding site (؊601) were identified to be the cis-elements for TGF-␤ or TNF-␣ activation, respectively. Taken together, these findings suggest a specific mechanism whereby multiple cytokines can regulate MMP-9 expression/activation in the cells of human skin. These results imply roles for these cytokines in the regulation of MMP-9 in physiologic and pathologic tissue remodeling.

Seven experiments were conducted to investigate whether a 19% CP corn and soybean meal (CS) diet could be fortified properly with amino acids (AA) to produce performance in 1- to 3-wk-old chicks equal to that obtained with a 23% CP, CS diet supplemented with Met. In one experiment, the assay was carried out to 6 wk of age. During 4- to 6-wk posthatching, the positive control was a 20% CP, CS diet with added Met and the low-protein diet was a 16% CP, CS diet fortified with limiting AA. The two most limiting AA in the low-protein diet (19% CP) were found to be Met and Lys. Arginine, Val, and Thr were observed to be limiting as well. Weight gain and feed efficiency were substantially increased and body fat content decreased when the low-protein diet was supplemented with the five limiting AA and amino nitrogen in the form of Glu. Addition of potassium had no effect on performance of chicks fed the AA-fortified, low-protein diet. With all trials considered together, chicks fed the low-protein diet fortified with the five limiting AA and Glu gained at the same rate with similar feed efficiency and had estimated body fat levels comparable to birds fed the 23% CP, positive control diet. From 3 to 6 wk of age, chicks fed the AA-fortified, 16% CP diet had growth performance similar to chicks fed the 20% CP, positive control diet.