scholarly journals Peptic digestion of beef myofibrils is modified by prior marination

2013 ◽  
Vol 57 (1) ◽  
pp. 20294 ◽  
Author(s):  
Nash Patel ◽  
Simon J. M. Welham
Keyword(s):  
2017 ◽  
Vol 231 ◽  
pp. 165-174 ◽  
Author(s):  
Ya-Fei Liu ◽  
Indrawati Oey ◽  
Phil Bremer ◽  
Patrick Silcock ◽  
Alan Carne

Author(s):  
Hanstter Hallison Alves Rezende ◽  
Jaqueline Ataíde Silva Lima da Igreja ◽  
Antônio Roberto Gomes-Júnior ◽  
Jade de Oliveira Melo ◽  
João Luís Garcia ◽  
...  

Abstract The aim of this study was to evaluate the genotypic characteristics of Toxoplasma gondii isolated from free-range chickens in the metropolitan area of Goiânia, Goiás, in Brazil’s central-west region. The seroprevalence rate was found to be 96%, according to an indirect hemagglutination assay. Brain and heart samples were processed by peptic digestion for a mice bioassay. The tissues were homogenized and the resulting samples were subjected to polymerase chain reaction (PCR), which revealed that 64% of them contained the parasite's DNA. The mice bioassay revealed 15 isolates, 8 of them tachyzoites isolates from the peritoneal lavage and 7 from brain cysts. T. gondii genotypes were determined through PCR-RFLP, using the following markers: SAG1, SAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1, alt. SAG2, Apico and CS3. Three genotypes were identified, inclued ToxoDB #65, and the other two are not yet described in the literature. Hence, we conclude that the isolates obtained from the metropolitan area of Goiânia showed relatively low genetic diversity.


1967 ◽  
Vol 7 (12) ◽  
pp. 556-559 ◽  
Author(s):  
John S. Crispin ◽  
Ward O. Griffen

1962 ◽  
Vol s3-103 (62) ◽  
pp. 173-203
Author(s):  
H. C. MACGREGOR ◽  
H. G. CALLAN

The chromomeres of lampbrush chromosomes of Triturus cristatus are Feulgen-positive; they therefore contain DNA. After removal of their DNA in boiling trichloracetic acid, the chromomeres stain with fast green at alkaline pH; they therefore contain basic protein. The lateral loops are Feulgen-negative; they stain with toluidine blue at acid pH, but much less intensely following RNase digestion; they therefore contain RNA. The spheres of chromosomes V and VIII do not contain RNA. Unfixed lampbrush chromosomes retain a life-like appearance in 0.07 M K/NaCl at pH 6.2; in this medium the nuclear sap disperses. As pH is raised to 8.5 the matrices of lateral loops dissolve but chromosome axes remain unbroken. Above pH 8.5 lampbrush chromosomes dissolve. As pH is lowered from 6.2, at between 5.8 and 5.4 coagulation occurs. If pH is rapidly reduced still further, a persistent relaxed condition sets in between 2.5 and 2. In concentrations of K/NaCl above 0.5 M lampbrush chromosomes dissolve. Lateral loop matrices dissolve in 0.25 M K/NaCl but chromosome axes remain unbroken. In concentrations of K/NaCl below 0.05 M lateral loop matrices dissolve, but even in distilled water chromosome axes remain unbroken. Trypsin at pH 6.2 and at pH 7.8 strips the matrices from lateral loops and occasionally breaks matrix fusions. It causes chromomeres to swell and coalesce, but fails to break chromosome axes. The action of ‘pan-protease’ resembles that of trypsin in all respects. Pepsin at pH 6.2 strips the matrices from lateral loops, but does not destroy chromomeres. At low pH peptic digestion is slow: the enzyme is attacking coagulated chromosomes; but if peptic digestion precedes a lowering of pH the overall outcome is a rapid solution of loop matrix, and under these conditions matrix and sphere fusions are broken. If trypsin or ‘pan-protease’ digestion precedes a lowering of pH there is a similarly rapid solution of loop matrix; thus the action is not specifically referable to pepsin. Under no conditions does pepsin break the axes of lampbrush chromosomes. RNase at pH 6.2 strips the matrices from lateral loops; this action is detectable at extreme dilution. RNase does not destroy chromomeres, nor does it break chromosome axes. If tryptic digestion follows RNase digestion this too fails to break chromosome axes. Unlike the proteolytic enzymes and RNase, DNase at pH 6.2 breaks the fibril between adjacent chromomeres, and it also breaks the axes of lateral loops. Contrary to Mazia's experience with salivary gland chromosomes, versene does not break the axes of lampbrush chromosomes even when applied in media of low electrolyte concentration. These results indicate that uninterrupted fibres of DNA run throughout the lengths of lampbrush chromosomes.


1943 ◽  
Vol 14 (2) ◽  
pp. 121-132 ◽  
Author(s):  
George F. Harsh ◽  
Harry L. Huber

1985 ◽  
Vol 115 (10) ◽  
pp. 1325-1336 ◽  
Author(s):  
Akiko Yashiro ◽  
Shinobu Oda ◽  
Michihiro Sugano

1988 ◽  
Vol 66 (5) ◽  
pp. 367-373 ◽  
Author(s):  
Sum P. Lee ◽  
Jane F. Nicholls ◽  
Anthony M. Roberton ◽  
Han Z. Park

Partially purified native-pig gastric mucus and purified pig gastric mucin, prepared by column chromatography and caesium chloride (CsCl) density-gradient ultracentrifugation, were subjected to pepsin digestion. The products of peptic digestion were chromatographed on Sepharose CL-2B, and fractions were assayed for carbohydrate by the periodic acid – Schiff reaction. The polymeric gastric mucin in the purified mucin samples was readily degraded by pepsin. In sharp contrast, the polymeric mucin in the partially purified mucus was relatively resistant to pepsin digestion. In 45 min, pepsin degraded 40% of the polymeric mucin in the purified samples, whereas it produced no significant degradation (<10%) in the partially purified mucus samples. In partially purified gastric mucus, treated with CsCl but not fractionated by ultracentrifugation, digestion with pepsin was also slow and incomplete. This showed that differences in susceptibility between partially purified and purified preparations are not due to the chaotropic effects of CsCl. In addition, the recombination of low-density nonmucin fractions in CsCl ultracentrifugation with the mucin also resisted pepsin digestion. Finally, we have shown that the low-density fractions in mucus exhibited a strong inhibitory effect of peptic activity in vitro. We conclude that under our experimental conditions, pepsin has little effect on partially purified mucus, and our findings indicate an inhibitor of peptic digestion is present in native gastric mucus. It is likely, but unproven, that this inhibitor is a noncovalently bound lipid present in the low-density fraction.


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