Differential scanning calorimetry of porcine adipose tissues.

Differential scanning calorimetry (DSC) was used for the direct analysis of melting properties in porcine subcutaneous, intermuscular, and kidney leaf adipose tissue by heating at a constant ratio of +5°C/min from 4 to 90°C. Melting curves for adipose tissues as well as fat extracted from the associated tissues by chloroform-methanol were generated using DSC. Major peaks in DSC curves were similar among types of adipose tissue but the temperatures of the melting peak and conclusion point differed among types of adipose tissues. From the visual appearance of fat samples it appeared that the major DSC peak corresponded to phase transition of the fat. The direct DSC analysis of porcine adipose tissues may be useful to determine melting properties.

Relationship between lipid peroxidation and fat content in Japanese Black beef Longissimus muscle during storage.

We examined the relationship of crude fat content to lipid peroxidation of beef during storage. Longissimus muscle samples (fat content; 6.5-39.4%) from 27 Japanese Black beef steers were stored for 1, 4, 7 and 10 days, and thiobarbituric acid reactive substances (TBARS) and lipid hydroperoxides (LOOH) were determined. TBARS values increased significantly (P<0.05), but LOOH did not change during the 10- day storage period. TBARS values were negatively correlated (P<0.05) with fat content in samples stored for 1, 4, 7 and 10 days. LOOH values, however, were not significantly correlated with fat content except on day 1. Phospholipid contents were correlated (P< 0.01) with LOOH values on each measurement day, but not significantly correlated with TBARS values except on day 1. These findings indicated that: (1) high-fat beef had high preservative properties, and that; (2) TBARS formation was correlated with LOOH derived from phospholipid oxidation in the initial period of storage, and was correlated directly with fat content in a later period.

The characteristics of muscle fiber types of longissimus thoracis muscle and their influences on the quantity and quality of meat from Japanese Black steers.

Forty-four Japanese Black fattening steers from four groups, produced in four districts and consisting of differing genetic backgrounds were slaughtered to examine the characteristic differences in muscle fiber types at the 6th thoracic vertebra of the M. longissimus thoracis (LT). The influence of percentage, diameter, and relative area of each muscle fiber type on the carcass characteristics and some quantity and quality traits of beef taken from LT, were also investigated. Significant differences in the characteristics of the muscle fiber types were observed among the four groups, except for muscle fiber diameter in the αR fiber, and the relative area of each αW fiber. For all steers, the average percentages and diameters of each muscle fiber type, ßR, αR and αW were 26.8, 18.5 and 54.7% and 51.4, 50.6 and 52.4 µm, respectively. The relative area of each fiber type was similar to those of muscle fiber composition. αR Fiber content had significant negative correlations with marbling score (p<0.05), intramuscular fat content (p<0.05) and ultimate pH value (p<0.05). Significant correlations between the diameter of each fiber type, and the quantity or quality traits of the meat were not found, with the exception of red fiber types (ßR and αR) and meat color a(∗) values (p<0.05) which were positively correlated.

Is nuclear expression of Y box-binding protein-1 a new prognostic factor in ovarian serous adenocarcinoma?

BACKGROUND: Nuclear expression of Y box-binding protein (YB-1), a member of the DNA binding protein family, has been reported to be much more highly concentrated in cisplatin-resistant cell lines than in their parental counterparts, suggesting an ability to limit cisplatin sensitivity. Moreover, YB-1 plays a key role in P-glycoprotein expression. Because ovarian carcinoma traditionally has been treated with cisplatin-based chemotherapy, the sensitivity of the tumors to chemotherapy could reflect a particular prognosis in patients with ovarian carcinoma. The aim of the current study was to determine whether YB-1 expression correlated with prognosis in ovarian serous adenocarcinoma patients. METHODS: The expression of YB-1 in the nucleus was examined immunohistochemically in 42 paraffin embedded primary Stage III (International Federation of Gynecology and Obstetrics) serous ovarian carcinoma tumors extirpated by primary surgery at Kyushu University Hospital between 1985-1995. RESULTS: Of the 40 primary ovarian tumors examined, 12 (30%) were positive for YB-1 expression in the nucleus. There was no significant difference in intraperitoneal stage, histologic grade, or residual tumor size after primary surgery between patients with tumors with positive and those with negative nuclear expression of YB-1 protein. The disease free survival curve for patients whose tumors were positive for nuclear expression of YB-1 protein was significantly worse than that for patients whose tumors were negative (P = 0.0025). P-glycoprotein was overexpressed in 4 of 12 tumors with nuclear YB-1 expression (33%) but there was no statistical significance between the expression of nuclear YB-1 and P-glycoprotein. CONCLUSIONS: The expression of YB- 1 protein in the nucleus may be considered a useful prognostic marker and also may reflect the sensitivity of ovarian serous adenocarcinoma to chemotherapy.

Histopathological factors influencing pelvic lymph node metastases in two or more sites in patients with cervical carcinoma undergoing radical hysterectomy.

BACKGROUND: Lymph node metastasis has been one of the strongest prognostic factors in patients with cervical cancer. In order to select patients with high risk for recurrence, a relationship between status of lymph node and other histopathological parameters was investigated in the patients treated with radical hysterectomy with pelvic lymph adnectomy. METHODS: Of 483 patients undergoing radical hysterectomy with pelvic lymph adnectomy, 309 had stage Ib disease, 62 stage IIa, and 112 stage IIb. RESULTS: Pelvic lymph node metastasis(PLNM) was positive in 98 patients (20%). Of those positive patients, 51(56%) had metastasis in one site, 25 (26%) in two sites, and 22 (22%) in three or more sites. There was a significant difference in survival between patients with metastasis in one or no sites and those in two or more sites (p<0.0001). There was a relationship between PLNM in more than two sites and histological parameters such as histologic subtype, longitudinal diameter of cervical lesion, degree of stromal invasion, depth of stromal invasion, lymph-vascular space invasion, parametrial invasion, and corpus invasion. All of these parameters except for histologic subtype were significantly correlated with the number of positive lymph node sites. Multivariate analysis revealed that among these parameters, longitudinal diameter of the cervical lesion, parametrial invasion, and lymph-vascular space invasion were independently significantly correlated with PLNM in two or more sites. CONCLUSIONS: From these results, patients having these three histopathological parameters could be considered as those with extensive disease distribution.

Comparison of p53 and CD44 variant 6 expression between paired primary and recurrent ovarian cancer: an immunohistochemical analysis.

Progression of malignant potential in ovarian cancer was investigated by comparing recurrent tumor with their primary tumor counterparts in terms of p53 and CD44 variant 6 (CD44v6) expression. Forty-three paired primary and recurrent tumors were immunohistochemically evaluated for expression of p53 and CD44v6. A paired analysis revealed that p53 and CD44v6 expression were significantly greater in recurrent tumors than those in the primary counterparts with statistical significance, respectively (P=0.0055 and 0.0071; Wilcoxon signed-rank test). No relationship between these two proteins was found. These results suggested that recurrent ovarian cancer may possibly express a stronger malignant potential in comparison to the primary tumor.

Emergence of higher levels of invasive and metastatic properties in the drug resistant cancer cell lines after the repeated administration of cisplatin in tumor-bearing mice.

To establish a more suitable model for reflecting biological aggressiveness in clinically recurrent cancers after chemotherapy, we made the in-vitro-established cisplatin-resistant cell lines, by exposing the parental tumor cell lines to cisplatin in a culture system, and also the in-vivo-established cisplatin-resistant cell lines by repeated cisplatin administration to parental tumor-bearing mice. Although both cell lines similarly demonstrated a clinically relevant low level of drug resistance (from 1.5 to 2.9 times more resistance to cisplatin than their parental cell lines), only the in-vivo-established cisplatin-resistant cell lines showed significantly enhanced metastatic properties with a 2.1- to 3.4-fold increase in the number of lung metastatic nodules. These enhanced metastatic properties were caused by tumor invasiveness in combination with various levels of enhancement of cell attachment, proteolytic enzyme activity and cell motility. We concluded that anticancer drugs such as cisplatin could promote tumor progression only in the drug-resistant cell lines established in vivo. As a result, these cell lines are considered to be a more faithful and useful model for expressing biological aggressiveness in clinically recurrent cancers after chemotherapy than the conventional drug-resistant cell lines established in vitro.

Effect of dietary vitamin E supplementation for one week before slaughter on drip, colour and lipid stability during display in Japanese Black steer beef.

Effects of dietary vitamin E supplementation for one week on drip, colour and lipid stability in raw beef steaks were studied. Four Japanese Black steers were fed no supplemental vitamin E and four were supplemented with 5000 mg of dl-α-tocopherol per animal daily for one week before slaughter. Steak samples from psoas major and longissimus thoracis muscles were over-wrapped with PVC film and displayed under fluorescent lights at 4 °C for 10 days. Drip loss percentages, L(∗), a(∗) and b(∗) values, metmyoglobin percentages, and 2-thiobarbituric acid reactive substances values were determined at day 1, 4, 7 and 10. Dietary vitamin E supplementation increased (p < 0.01) α-tocopherol concentration in the plasma, liver and muscles. Vitamin E supplementation reduced (p < 0.001) drip loss compared to the control. Vitamin E supplementation maintained (p < 0.001) redness and retarded (p < 0.01) metmyoglobin formation in beef steak from day 4 to day 10 of display compared to the control. Vitamin E supplementation delayed (p < 0.001) lipid oxidation during 10 days of display compared to the control. The data indicated that dietary vitamin E supplementation for one week prior to slaughter improved lipid stability better than drip and colour stability in beef steak during 10 days of display.

Culture conditions supporting adipose conversion of stromal-vascular cells from bovine intramuscular adipose tissues.

The culture conditions which are able to support the differentiation of bovine intramuscular (i.m.) stromal-vascular (S-V) cells into adipocytes were investigated. Bovine i. m. S-V cells were able to undergo adipose conversion, assessed by emergence of lipid droplets and induction of glycerol-3-phosphate dehydrogenase (GPDH) activity, when treated with 0.25 microM dexamethasone and 0.5 mM 1-methyl-3-isobutylxanthine in a serum-deprived (0.1%) medium containing 850 nM insulin and 1 mM octanoate. Octanoate was essential for morphological differentiation and addition of 25 microM of cholesterol with octanoate induced higher GPDH activity. The differentiation of the cells was not observed in the medium containing 10% fetal calf serum which supported the cell proliferation of undifferentiated cells even after confluence. Similarly, both bovine brain extracts and muscle extracts inhibited the differentiation of S-V cells in the serum-deprived condition. These results suggest that the existence of lipids such as octanoate and the process of growth-arrest in preadipocytes and/or other cells are necessary for the differentiation of bovine S-V cells into adipocytes in culture.

Dietary vitamin E supplementation shifted weight loss from drip to cooking loss in fresh beef longissimus during display.

Effects of dietary vitamin E supplementation on drip loss, cooking loss, and muscle fiber disruption in fresh beef loin steaks from Holstein and crossbred beef steers were studied. Nine Holstein steers and nine beef steers were fed a control diet and nine Holstein steers and eight beef steers were supplemented daily with 298 IU of vitamin E/kg of diet for 211, 232, or 252 d. Drip loss, cooking loss, cooking yield, and shear value were measured in each longissimus lumborum sample displayed in PVC film for 2, 6, 10, or 14 d. Dietary vitamin E supplementation produced meat that had smaller (P < .001) increases in drip loss during 14 d of display but higher (P < .01) cooking losses. Cooking yield was reduced (P < .05) by vitamin E supplementation. Vitamin E supplementation reduced (P < .01) muscle cell disruption in beef steak displayed for 14 d. These results indicated that dietary vitamin E treatment stabilized cell integrity and enhanced the ability of beef steak to hold sarcoplasmic components during display, although subsequent losses due to cooking were greater.

Relationship between Japanese beef marbling standard and intramuscular lipid in the M. longissimus thoracis of Japanese Black and American Wagyu Cattle.

Japanese Black and American Wagyu steers (n = 155) were slaughtered and graded under typical Japanese production conditions, and then analyzed for percentage ether-extractable fat at the 6th thoracic vertebra. The percentage of intramuscular lipid was used to develop a prediction equation for the Japanese beef marbling standard (BMS) with R(2) = 0·7619.

Dietary versus postmortem supplementation of vitamin E on pigment and lipid stability in ground beef.

Effects of dietary supplementation and postmortem addition of vitamin E on pigment and lipid stability in raw ground beef were examined in this study. Six Holstein steers were fed a control diet for 232 or 252 d and six Holstein steers were supplemented with 1,500 IU of vitamin E per animal daily for 232 or 252 d. Three aliquots of ground beef from each longissimus lumborum were allotted to the following postmortem treatments: no addition (NO), white mineral oil (OIL), and white mineral oil containing sufficient D-alpha-tocopherol to equal the mean difference of alpha-tocopherol concentration between beef from supplemented and control steers (OIL + E). Metmyoglobin percentages and 2-thiobarbituric acid reactive substances values were determined at d 1, 3, 5, 7, and 9 after postmortem treatment. Dietary vitamin E supplementation delayed metmyoglobin increase and highly suppressed lipid oxidation in ground beef during 9 d of display compared with the control. The postmortem addition of vitamin E (OIL + E) was slightly effective in retarding the oxidation of pigment and lipid, especially compared with the OIL treatments. Endogenous vitamin E improved pigment and lipid stability much better than exogenous vitamin E.