Analysis of cholesterol oxides in egg yolk and turkey meat

A study was conducted to develop a solvent system that will clean egg yolk samples and concentrate cholesterol oxides effectively before analysis. Cholesterol oxide standards or lipid samples (0.2 g) loaded onto a silicic column were washed with a portion of Solvent I (hexane/diethyl ether, 9:1, vol/vol) and then with Solvent II. Four different Solvent II preparations (Solvent IIa, hexane:ethyl acetate = 4:1; Solvent IIb, hexane:ethyl acetate = 1:1; Solvent IIc, hexane:ethyl acetate:diethyl ether = 2:1:1; Solvent IId, hexane:ethyl acetate:diethyl ether = 4:1:2, vol/vol/vol) were prepared and the purification efficiencies of Solvent II solutions for neutral lipids, cholesterol, and phospholipids in the column were compared. Yield study using cholesterol oxide standards showed that one or more of the cholesterol oxide standards were eluted by the Solvent IIb and Solvent IIc, but Solvent IIa and Solvent IId did not elute any of the cholesterol oxides during washing. Egg samples prepared with Solvent IIa showed greater amount of cholesterol oxides than those prepared with Solvent IId, probably due to incomplete purifying of phospholipids and interference. However, the amounts of cholesterol oxides in cooked meat prepared with the two purification solvents were not different. Because egg yolk contains very large amounts of phospholipids and cholesterol compared with other foods, at least twice as much Solvent IIa as Solvent IId was required to properly clean egg yolk samples. It was concluded that purification solvents should be selected by sample types, and Solvent IId (hexane:ethyl acetate:diethyl ether = 4:1: 2) was superior to Solvent IIa (hexane:ethyl acetate = 4: 1) for egg yolk samples.

Effect of dietary conjugated linoleic acid on the quality characteristics of chicken eggs during refrigerated storage

Twenty-four, 79-wk-old White Leghorn hens were assigned randomly to three diets containing 0, 2.5, or 5.0% conjugated linoleic acid (CLA). The diets were fed for 4 wk to determine the effect of dietary CLA on quality characteristics of eggs. Eggs were collected daily and stored at 4 C for 1, 7, 21, or 49 d. At the designated times, the eggs were processed to evaluate water content, fatty acid composition, color, proportions and pH of yolk and albumen. Firmness of yolk after the eggs were hard-cooked was also determined. The proportions of myristic, palmitic, stearic, CLA (9-cis, 11-trans CLA and 10-trans, 12-cis CLA isomers), and unidentified fatty acids in egg yolk lipids were increased as dietary CLA increased, but those of palmitoleic, oleic, linoleic, linolenic, arachidonic, and docosahexaenoic acid were decreased. Duration of refrigeration increased the proportion of egg yolk but decreased the contents of albumen and yolk lipids after 21 d or longer of storage. Egg yolk pH increased as refrigeration time increased, regardless of dietary treatment, but the increase was greater in the eggs produced by hens fed the CLA diets. Albumen pH increased significantly after 7 d of storage but remained unchanged until 21 d and then decreased by 49 d. Dietary CLA had no effect on the pH of albumen until 49 d of storage. After 49 d storage, egg albumen pH from hens fed CLA diets was lower than that of albumen from hens fed the control diet. Yolk color was not influenced by the dietary CLA and storage, but the egg yolk surface from hens fed CLA diets sometimes had relatively dark color with light spots. Dietary CLA and storage of CLA eggs increased the firmness of hard-cooked egg yolk. The texture of yolks from hard-cooked CLA eggs was rubbery and elastic, and the yolks were more difficult to break using an Instron. It was speculated that the quality changes of CLA eggs were related to the increase of yolk water content, the movement of ions between yolk and albumen through yolk membrane, and the changes of egg yolk pH during storage.

Effects of dietary vitamin E supplementation on lipid oxidation and volatiles content of irradiated, cooked turkey meat patties with different packaging

A study was conducted to determine the effects of dietary vitamin E supplementation on the storage stability and volatiles production in irradiated cooked turkey meat. Turkeys, raised with diets containing 25, 50, 75, or 100 IU of dl-alpha-tocopheryl acetate (TA)/kg diet from 1 to 105 d of age, were fed with diets containing 25, 200, 400, or 600 IU of TA/kg diet from 105 to 122 d of age. Breast and leg meat patties were prepared, irradiated at 0 or 2.5 kGy dose, cooked to an internal temperature of 78 C, and stored in either vacuum or aerobic packaging. Thiobarbituric acid reactive substance (TBARS) values gradually decreased as the dietary TA increased and > 200 IU TA/kg diet treatments were helpful in maintaining low TBARS values in irradiated breast and leg meat patties during the 7-d storage period. With vacuum-packaging, irradiated cooked breast patties developed more oxidation than nonirradiated patties but the prooxidant effect of irradiation in cooked leg meat patties was not consistent. In aerobic-packaged cooked meat, irradiated patties had lower TBARS than nonirradiated patties in both breast and leg meat stored in oxygen permeable bags for 7 d. Propanal, pentanal, hexanal, 1-pentanol, and total volatiles were highly correlated with the TBARS values of meat. However, hexanal represented the lipid oxidation status of cooked meat better than any other volatiles component. The amount of hexanal and total volatiles in cooked breast and leg meat shows decreasing trends as dietary TA increased. In vacuum packaging, irradiated breast and leg meat had higher hexanal and total volatiles content than nonirradiated meat at both 0 and 7 d of storage. In aerobic packaging, the amount of hexanal and total volatiles greatly increased in both irradiated and nonirradiated meat patties during the 7-d storage periods. The results illustrated that the antioxidant effect of TA was not strong enough to control lipid oxidation and off-odor generation in cooked meat stored under aerobic conditions because the progress of lipid oxidation in cooked meat under aerobic condition is very rapid. However, the combination of dietary TA and vacuum packaging of cooked meat immediately after cooking could be a good strategy to minimize oxidation and volatiles production in cooked meat.

Fluorometric analysis of 2-thiobarbituric acid reactive substances in turkey

Three experiments were conducted to develop a sensitive and reliable fluorometric thiobarbituric acid (TBA) reactive substances (TBARS) method to determine lipid oxidation products in meat. The first study was conducted to find the optimum sample preparation conditions for meat in the fluorometric method. The second study was to compare the original and the modified methods by using meat and blood samples. The modified fluorometric method was compared with a conventional spectrophotometric method in a third study. Four different extraction solutions (2.5 M acetic acid, 0.5 M hydrochloric acid, 0.8 M perchloric acid, and 1.4 M trichloroacetic acid) and two ratios of extraction solution to TBA (20 mM) solutions (2:1 and 1:1) were examined in the first study. Hydrochloric acid was the optimum among the four extraction solutions tested, and the ratio of extraction solution to TBA solution at 1:1 was the best for the fluorometric TBARS method in raw ground turkey. The modified fluorometric method had high recovery rates (91%, average), and the regression coefficient of the standard curve prepared with spikes was also high (r2 = 0.99). The analysis of raw meat and plasma samples indicated that the modified fluorometric method had greater sensitivity than the original method. The pH of the reaction mixture played an important role in extraction TBARS from samples, and low pH conditions were preferable to high pH conditions. The amount of lipid oxidation products in raw turkey breast meat indicated that the fluorometric method had much greater sensitivity than the spectrophotometric method. The results from the three studies showed that the modified fluorometric TBARS method was useful for the samples with low lipid oxidation products, such as fresh raw meat. The sensitivity of the modified fluorometric method also facilitates the determination of oxidation products in small quantities of samples.

[Diffuse aspiration bronchiolitis (DAB) produced in animals by repeated HCl microaspiration]

We recently reported that diffuse aspiration bronchiolitis (DAB) was detected in 1% of autopsied lungs of aged cases of pneumonia. We hypothesized whether repeated HCl micro-aspiration (RHMA) is involved in DAB and established an animal model by administering HCl intratracheally to rats every two days for 2 weeks. Saline was given to control animals in the same fashion. Then, we performed bronchio-alveolar lavage (BAL) or excised lungs for histologic examination. There was no difference in BAL cell counts, TNF alpha-production, elastase-like activity or albumin levels between the HCl and control groups. Histologically, DAB-like findings were observed in the HCl-treated animals. These data suggest that RHMA might be involved in DAB, while neither TNF alpha-production nor elastase-like activity may play a significant role in inducing DAB.

[An aspiration pneumonia in acute airway damage model induced by HCl and/or LPS]

The purpose of this study is to evaluate chemical and pathological changes of the lung and to elucidate the role of TNF alpha and elastase in acute lung injury induced by HCl or lipopolysaccharide (LPS). Anesthetized rats were injected with pH 1.4 0.7 ml/kg body weight of HCl and 0.5 mg/kg body weight (BW) of LPS (E. coli) into the lung. Acute tracheal injury model (Mendelson Syndrome) were made. Control animals received only saline. Animals were sacrificed 1, 6, or 12 hours after the HCl or LPS or HCl and LPS injection, bronchoalveolar-lavage (BAL) was performed in the same way in control and experimental groups. The other animals which were treated as well were excised by histology. There was neither increase in TNF alpha-production nor increase in neutrophils resulting from HCl injection only. Elastase-like activity was not detected in animals treated only with HCl. However, 1 hour after LPS injection, the production of TNF alpha (37.0 +/- 8.0 Units/ml) was significantly greater than that of the control group (12.1 +/- 4.2 Units/ml) in BALF. Six hours after HCl and LPS injection, the concentration of elastase-like activity (0.023 +/- 0.002 nM) was significantly greater than that of the LPS group (0.011 +/- 0.001 nM). Only patches of intraalveolar hemorrhage and elevation of fibrin was observed in the HCl injected rats at 1 hour after injection. Six hours after LPS injection, the alveolar spaces were filled with large amounts of neutrophils. These findings suggest that TNF alpha and elastase play a significant role in HCl and LPS-induced acute lung injury.

[Two elderly cases with acute exacerbation of interstitial pneumonia]

We studied two cases of the elderly with acute exacerbation of interstitial pneumonia to elucidate a prognostic role of super oxide generation in peripheral whole blood. The first case was a 70-year-old man, who presented with acute exacerbation of interstitial pneumonia and was hospitalized. Following steroid-pulse therapy, CRP, ESR, blood-gas and his physical condition improved, resulting in successful discharge. In this case, super oxide generation standardized by the number of neutrophils (K) decreased to less than 1.0 in association with the improvement of physical condition. The second case was a 92-year-old woman in whom acute exacerbation of interstitial pneumonia was diagnosed. While the pulse therapy, CRP, LDH and blood-gas temporarily improved, K was continuously greater than 1.0 and the physical condition worsened, resulting in her death. These cases suggest that the measurement of super oxide generation in peripheral whole blood may play a useful role in assessing the prognosis of the elderly with acute exacerbation of interstitial pneumonia.

[Analysis of nocturnal disturbed breathing in the elderly using desaturation index]

This study was conducted to examine the nocturnal ventilatory parameters and gas exchange in the elderly with nocturnal disturbed breathing. In order to facilitate analysis of ventilatory parameters with minimum manpower, we developed an unattended continuous nocturnal monitoring system for ventilation and arterial oxygen saturation. Using this system, nocturnal ventilatory parameters and gas exchange were investigated in our geriatric ward. We investigated 30 elderly subjects aged between 65 and 94 (mean age 77.8 +/- 6.5 years, male; female = 15:15). The subjects were free of severe cardiovascular and cerebrovascular disorders, and underwent 10 hours of continuous monitoring of ventilation and arterial oxygen saturation (SaO2). Number of significant desaturation (SDS; desaturation greater than 4% in SaO2 from the baseline value) and desaturation index (DI; sigma SDS(%) x duration (hour)) were calculated using the same system. The number of apnea episodes significantly correlated with DI and the number of SDS. DI also significantly correlated with lowest SaO2, while the number of SDS and the number of apneas were not found to be correlated with lowest SaO2. The number of SDS and the number of apnea episodes did not correlated with lowest SaO2. From the view point of gas exchange during the night, newly introduced DI is more comprehensive parameter when compared with the number of apneas or SDS. Subjects with a DI of over 0.5 were assigned to the group A (n = 8, mean age = 77.8) and the remaining subjects were assigned to group B (n = 22, mean age = 77.8). We compared the group A with the group B regarding nocturnal ventilatory parameters and SaO2.(ABSTRACT TRUNCATED AT 250 WORDS)

Intravenous bolus of prednisolone decreases 15-hydroxyeicosatetraenoic acid formation in the rat model of acid aspiration

BACKGROUND AND METHODS

To test the hypothesis that the effect of steroids on hydrochloric acid aspiration may be involved in the metabolism of eicosanoids, we investigated the effects of an iv bolus of prednisolone on the metabolism of 15-hydroxyeicosatetraenoic acid and 11-dehydrothromboxane B2 (11-dehydro-TxB2) in the rat model of acid aspiration. Wistar rats were randomly selected for three groups and treated with either a) an iv bolus of saline after intratracheal injection of saline (control group), b) an iv bolus of saline after intratracheal injection of acid (acid-saline group), or c) an iv bolus of prednisolone after intratracheal injection of acid (acid-prednisolone group). The concentrations of 15-hydroxyeicosatetraenoic acid and 11-dehydro-TxB2 in bronchoalveolar lavage fluid were measured by radioimmunoassay.

RESULTS

The concentration of 15-hydroxyeicosatetraenoic acid in bronchoalveolar lavage fluid of either acid-saline group (804 +/- 129 pg/mL) or acid-prednisolone group (748 +/- 112 pg/mL) was significantly greater than that of the control group (143 +/- 27 pg/mL, p less than .01) 1 hr after the administration. The iv bolus of prednisolone caused a significant decrease in 15-hydroxyeicosatetraenoic acid (acid-saline group 1027 +/- 43 pg/mL; acid-prednisolone group 514 +/- 62 pg/mL; p less than .01) and cell counts of bronchoalveolar lavage fluid 48 hrs after intratracheal injection of acid, while there was no significant change in 11-dehydro-TxB2.

CONCLUSION

These findings suggest that corticosteroid administration may contribute to the inhibition of the inflammatory process of lungs after acid aspiration by decreasing the release of 15-hydroxyeicosatetraenoic acid in the distal lung unit.

[Analysis of ventilatory parameters of nocturnal disturbed breathing in the elderly]

To elucidate the effects of aging on ventilation in nocturnal disturbed breathing (NDB), we investigated 16 subjects aged 65 years or over with system developed by the authors using a respiratory inductive plethysmography connected to a personal computer. The subjects underwent 10 hours of continuous monitoring of lung volume and SaO2. Significant desaturation (SDS, greater than 4% drop in SaO2 from baseline value) and desaturation index [DI, sigma SDS(%) X duration (hr)] were calculated using the same program. The subjects with SDS below 50 were assigned to group A (n = 9, mean age = 79.7, male:female = 8:1) and the remaining subjects with SDS over 50 (n = 7, mean age = 74.7, male:female = 3:4) to group B. There was no significant difference in ventilatory parameters between group A and B. We then compared the male group (n = 11, mean age = 77.8) with the female group (n = 5, mean age = 76.8). The number of SDS in the female group (101.4 +/- 34.7) was significantly greater than that of the male group (33.4 +/- 8.3*, p less than 0.02), while minute ventilation of the female group (5.25 +/- 0.31 l/min) was significantly smaller than that of the male group (8.86 +/- 1.36* l/min, p less than 0.05). DI was found to significantly correlate with the SaO2 nadir and the number of apnea and SDS. There was no significant relationship between SDS and ventilatory parameters in this study. NDB among elderly female may be of more importance than has been reported.

[Cisplatin and vinca alkaloid combination chemotherapy of advanced non-small-cell lung cancer in the aged]

Fifteen patients aged over 65 years of age with advanced non-small-cl lung cancer (mean age = 70.7, stage IIIb: IV = 4:11) were treated with combination chemotherapy consisting of Cisplatin (50 or 80 mg/m2) and a vinca-alkaloid (Vindesine 3 mg/m2 or Etoposide 80 mg/m2). The effectiveness and side effects of this cisplatin therapy in different combinations of vinca-alkaloid regimens (Vindesine vs Etoposide) were examined. The mean dose of Cisplatin in the Etoposide combination group (75.2 mg/m2) was significantly higher than that in the Vindesine combination group (54.3 mg/m2) (p less than 0.01). A notable reduction the tumor size was observed in 25% of the Etoposide group, only. The 6-month survival rate and one-year survival rate were respectively 85.7%, 57.1% in the Vindesine + Cisplatin group, and 87.5%, 50% in the Etoposide + Cisplatin group. The common side effects were nausea, vomiting, anorexia, and alopecia. These symptoms were either alleviated by antiemetic drugs or followed by spontaneous recovery. Leucopenia, anemia and thrombocytopenia were found in both groups, and there was no difference in the time course of myelosuppression between the two groups. The extent of nephrotoxicity was assessed by creatinine clearance rate. Its decrease in the Vindesine group (60.1----38.9 ml/min) was higher than that in the Etoposide group (64.9----48.9 ml/min), while there was no significant change in BUN, serum creatinine and urine NAG between the two groups. There were no cases in which chemotherapy schedules had to be interrupted due to myelosuppression and nephrotoxicity.(ABSTRACT TRUNCATED AT 250 WORDS)

Endothelin-1 stimulates arachidonate 15-lipoxygenase activity and oxygen radical formation in the rat distal lung

We investigated the effects of intravenous bolus of endothelin-1 on the metabolism of eicosanoids and oxygen radicals in the distal lung unit of the rat. Intravenous bolus of endothelin-1 caused a significant increase in 15-hydroxyeicosatetraenoic acid of bronchoalveolar lavage fluid and oxygen radicals produced by the bronchoalveolar cells. Endothelin-1 exhibited a stimulatory effect on the 15-lipoxygenase activity in the lung homogenate. Thus, endothelin-1 may contribute to the inflammatory and hyperreactive process of lungs, by enhancing the release of 15-hydroxyeicosatetraenoic acid and oxygen radicals in the distal lung unit.