SAF Group Research Articles

Laparoscopic inguinal total extraperitoneal hernia repair under spinal anesthesia without mesh fixation in 1,220 hernia repairs

The need for general anesthesia and the cost and pain due to metal staples required for fixing the mesh are the major reported disadvantages of laparoscopic total extraperitoneal (TEP) hernia repair. We studied the feasibility and results of TEP done under spinal anesthesia with non-fixation of the mesh (SA-NF). This group was compared to TEP done under general anesthesia with non-fixation of the mesh (GA-NF) and repairs done under SA with fixation of the mesh (SA-F). A retrospective analysis was carried out in 675 patients (1,289 hernias) in whom TEP was performed. The recurrence rate, pain scores at 24 h and 1 week, hospital stay, days to resume normal activities, seroma formation, and urinary retention rates were noted. A total of 1,289 TEP repairs (675 patients) were analyzed, with 636 patients (1,220 hernias) in the SA-NF group, 16 patients (27 hernias) in the GA-NF group, and 23 patients (42 hernias) in the SA-F group. Follow up ranged from 13 to 45 months. The recurrence rates, conversion rates, and complications were similar in all three groups. The mean hospital stay, days to resume normal activities, and pain scores were significantly higher in the mesh fixation (SA-F) group. TEP, done under SA and without fixation of the mesh, is safe, feasible, and associated with low recurrence rates. Since this procedure does not have the disadvantages usually attributed to TEP, it can be possibly recommended as a first-line procedure, even for unilateral inguinal hernias. Further studies are needed to substantiate this.

The effect of feeding rosemary, oregano, saffron and &#945-tocopheryl acetate on hen performance and oxidative stability of eggs

In this study the effects of feeding rosemary, oregano, saffron and α-tocopheryl acetate on hen performance and egg quality were investigated. One hundred-twenty Lohmann laying hens, 32 weeks old, were divided into five groups replicated four times with six hens per replicate. One group was given a basal diet and served as control (CON). The experimental diets given to the other four groups were based on the basal diet but contained an additional 200 mg α-tocopheryl acetate/kg (TOC), or rosemary at 5 g/kg diet (ROS), oregano at 5 g/kg diet (ORE) or saffron at 20 mg/kg diet (SAF). At the end of the feeding trial that lasted 56 days, hen performance and some egg quality characteristics were determined, whereas the oxidative stability of the refrigerated stored shell eggs and liquid yolks were also examined. Results showed no significant differences in egg production, feed intake, feed conversion ratio, egg weight and shape, yolk shape, Haugh units and shell thickness among treatments. However, yolk colour was significantly improved in the SAF group compared to all other groups. The extent of lipid oxidation in shell eggs differed among the dietary treatments, but did not change with storage time. In liquid yolk at pH 6.2, lipid oxidation was higher in the CON group compared to all other groups. The ORE group presented lower oxidation rate than the ROS group, but higher than the SAF group, which in turn exhibited higher oxidation rate than the TOC group. When liquid yolk was acidified to pH 4.2, the lipid oxidation profile remained unchanged but the rate was much more intense. Keywords: Rosemary; oregano; saffron; α-tocopherol acetate;egg quality; hen performance; oxidative stability South African Journal of Animal Sciences Vol. 35 (3) 2005: pp.143-151

Identification of Good Responders to Rhythm Control of Paroxysmal and Persistent Atrial Fibrillation by Transthoracic and Transesophageal Echocardiography

Background: Identification of good responders to rhythm control in the management of atrial fibrillation (AF) is worthwhile in terms of increasing hemodynamic benefit and decreasing the likelihood of unstable anticoagulation even after the Atrial Fibrillation Follow-Up Investigation of Rhythm Management. Methods: We tested the hypothesis that atrial substrate determines the risk of recurrence on rhythm control both in patients with paroxysmal AF (PAF) and in those with persistent or sustained AF (≧1 week, SAF). There were 90 consecutive patients (mean age 63 ± 12 years, 67 males and 23 females) with previous PAF (n = 66) or SAF (n = 24). They were maintained in sinus rhythm successfully for at least 1 month after conversion and then studied by transthoracic and transesophageal echocardiography. All of the patients were followed regularly by determination of symptoms, 12-lead ECG and intermittent Holter recording to determine recurrence of AF after echocardiographic study. Results: After 9.1 ± 3.8 (range 3–12) months of follow-up, 23 of the 90 (26%) patients had documented recurrence of AF (67 without recurrence). Univariate analysis of demographic characteristics, medications, ECG and echocardiographic parameters revealed that, compared with the group of patients without recurrent AF, the group of those with it included more members of the SAF group (11/27 vs. 13/67, p = 0.039), included more male subjects (22/23 vs. 45/67, p = 0.045), had a larger left atrial volume index (LAVI; 27 ± 9 vs. 22 ± 9 ml/m², p = 0.024) and had lower LA appendage peak emptying velocity (LAAPEV; 42 ± 15 vs. 55 ± 22 cm/s, p = 0.01). Multivariate Cox proportional hazards regression analysis adjusted for age, gender and AF group revealed that patients with LAVI <30 ml/m² and LAAPEV >46 cm/s had the least recurrence of AF (relative risk 0.18, 95% confidence interval 0.06–0.55, vs. with LAVI >30 ml/m² or LAAPEV <46 cm/s, p = 0.002). Kaplan-Meier probability of freedom from AF recurrence was significantly better when LAVI <30 ml/m² (log-rank p = 0.02), LAAPEV > 46 cm/s (p = 0.013) or both (p = 0.004). The superiority to predict the rate of sinus rhythm maintenance was the same in the PAF and SAF groups. Conclusions: Good responders to rhythm control in the PAF and SAF groups share the characteristics of smaller LA volume and better LAA contractile function, emphasizing the critical role of atrial substrate remodeling in recurrence of AF.

Safflower ( Carthamus tinctorius L.) as a novel pasture species for dairy sheep in the Mediterranean conditions of Sardinia and Israel

The nutritional value of sown safflower ( Carthamus tinctorius L.) annual pastures for Mediterranean dairy sheep was investigated in the Northern Negev Desert of Israel (250 mm of rainfall) with Awassi hoggets and in Sardinia (Italy, 590 mm of rainfall) with Sarda milking ewes. Safflower (termed “Saf”) was compared with barley (“Bar”) in Israel, and with chicory ( Cichorium intybus L., termed “Chi”) and burr medic ( Medicago polymorpha L., termed “Bm”) in Sardinia. In Israel, hoggets grazed more DM (1.8 kg d −1 versus 1.5 kg d −1, P < 0.05), and gained more weight (103 g d −1 versus 44 g d −1, P < 0.05) when grazing safflower than barley. In Italy, the nutritional quality of safflower pasture declined earlier than that of the other pastures. Ewes in the safflower, chicory and burr medic paddocks produced similar milk yields (1.21 ± 0.04 l d −1). Milk fat was lower for Saf than for Bm (5.92 and 6.92%, respectively, P < 0.05). Ewes in the Saf group also produced milk poorer in protein than their counterparts in the Bm group (5.15 and 5.64%, respectively, P < 0.05), possibly because of the higher content of total polyphenols and tannins of safflower. The ewes grazing Chi gained more weight than the counterparts grazing Saf or Bm ( P < 0.05). Our data suggest that, owing to good resistance to drought, safflower has the potential of lengthening the duration of lush green pasture under arid (Israel) but not milder semi-arid (Sardinia) Mediterranean conditions.

Effect of dietary oils enriched with n-3 fatty acids on survival of mice

Female mice were fed a conventional diet, shifted at 119 days of age to a diet supplemented with 10 wt % lard (Lar), high-linoleic (n-6) safflower oil (Saf), rapeseed oil (low-erucic, Rap), high-α-linolenic (n-3) perilla oil (Per) or a mixture (1:9) of ethyl docosahexaenoate (n-3) and soybean oil (DHA/Soy). Weight gain was less in the Per group than in the other groups at 497 days of age. In the Rap group, proteinuria was more severe than in the Saf, Per and DHA/Soy group, and hepatic triacylglycerol accumulation was greater than in the other groups. The mean survival time of the DHA/Soy group (753 days) was significantly longer than in the Lar group (672 days) and Saf group (689 days); the differences among other groups (e.g., 701 days in the Per group and 712 days in the Rap group) were not statistically significant. Although DHA is more susceptible to auto-oxidation than other major fatty acids in the air, an oil containing DHA was found to increase the survival of mice. Rapeseed oil that decreases the survival time of SHRSP rats was found to be safe in the mouse strain used in this study when survival was an end point.

Effect of n-3 fatty acid deficiency on fatty acid composition and metabolism of aminophospholipids in rat brain synaptosomes.

Docosahexaenoic acid (DHA, 22:6n-3) is one of the major polyunsaturated fatty acids esterified predominantly in aminophospholipids such as ethanolamine glycerophospholipid (EtnGpl) and serine glycerophospholipid (SerGpl) in the brain. Synaptosomes prepared from rats fed an n-3 fatty acid-deficient safflower oil (Saf) diet had significantly decreased 22:6n-3 content with a compensatory increased 22:5n-6 content when compared with rats fed an n-3 fatty acid-sufficient perilla oil (Per) diet. When the Saf group was shifted to a diet supplemented with safflower oil plus 22:6n-3 (Saf + DHA) after weaning, 22:6n-3 content was found to be restored to the level of the Per group. The uptake of [3H]ethanolamine and its conversion to [3H]EtnGpl did not differ significantly among the three dietary groups, whereas the formation of [3H]lysoEtnGpl from [3H]ethanolamine was significantly lower in the Saf group than in the other groups. The uptake of [3H]serine, its incorporation into [3H]SerGpl, and the conversion into [3H]EtnGpl by decarboxylation of [3H]SerGpl did not differ among the three dietary groups. The observed decrease in lysoEtnGpl formation associated with a reduction of 22:6n-3 content in rat brain synaptosomes by n-3 fatty acid deprivation may provide a clue to reveal biochemical bases for the dietary fatty acids-behavior link.

Dietary n-3 fatty acid deficiency decreases nerve growth factor content in rat hippocampus

Dietary deprivation of α-linolenic acid (n-3) through two generations has been shown to lower performance in an operant-type brightness-discrimination learning test in rats. Here, we examined a possible correlation between nerve growth factor (NGF) content and n-3 fatty acid status in the brain. Female rats were fed a semipurified diet supplemented with safflower oil (n-3 fatty acid-deficient) and their offsprings were fed a diet supplemented with either 3% safflower oil (Saf group) or a mixture of 2.4% safflower oil plus 0.6% ethyl eicosapentaenoate (Saf+EPA group) after weaning. The brain docosahexaenoic acid (22:6n-3, DHA) content in the Saf group was less than half of that in the Per group fed a diet supplemented with 3% perilla oil (n-3 fatty acid-sufficient) throughout the duration of the experiment. The DHA level of the Saf+EPA group was restored to the level of the Per group. However, the NGF contents in the hippocampus of the Saf and Saf+EPA groups were half that of the Per group. In the piriform cortex, the NGF content tended to be higher in the Saf and Saf+EPA groups than in the Per group. These results indicate that dietary n-3 fatty acid deficiency and restoration affect NGF levels differently among different brain regions.

Dietary (n-3) Polyunsaturated Fatty Acids Suppress Murine Lymphoproliferation, Interleukin-2 Secretion, and the Formation of Diacylglycerol and Ceramide , ,

Elucidation of the mechanism(s) by which dietary fish oil, enriched in eicosapentaenoic acid [EPA, 20:5(n-3)] and docosahexaenoic acid [DHA, 22:6(n-3)], suppresses the inflammatory process is essential in maximizing this potentially therapeutic effect. Murine T-lymphocyte function and signal transduction were examined in response to a low fat, short term diet enriched in highly purified EPA or DHA ethyl esters. For 10 d, mice were fed comparable diets containing either 3% safflower oil ethyl esters (SAF), 2% SAF + 1% arachidonic acid triglyceride (AA), 2% SAF + 1% EPA, or 2% SAF + 1% DHA. Concanavalin A-induced T-lymphocyte proliferation in splenocyte cultures was significantly suppressed by dietary EPA and DHA while AA had no effect relative to the SAF control. The suppressed proliferative response in EPA- and DHA-fed mice was preceded temporally by a significant reduction in IL-2 secretion. Kinetics of mitogen-induced diacyl-sn-glycerol (DAG) and ceramide production did not differ significantly between SAF and AA diet groups. In contrast, DAG production was significantly suppressed in EP- and DHA-fed mice relative to the SAF and AA groups. The reduced DAG mass was paralleled by reduced ceramide mass following EPA and DHA feeding compared to the SAF and AA groups. Thus, low dose, short term dietary exposure to highly purified EPA or DHA appears to suppress mitogen-induced T-lymphocyte proliferation by inhibiting IL-2 secretion, and these events are accompanied by reductions in the production of essential lipid second messengers, DAG and ceramide.

Effect of Dietary Fat on the Response of the Rat Retina to Chronic and Acute Light Stress

We designed an experiment to study the role of light history and polyunsaturated fatty acids (PUFA) on the susceptibility of the albino rat retina to light damage. Albino rats were born to dams that had been kept in either 1 lx or 250 lx cyclic light for 0-4 days prior to delivery and fed one of three diets containing either 10% (by weight) hydrogenated coconut oil (COC, no n-3 nor n-6 fatty acids), safflower oil (SAF, high n-6, < 0.1% n-3 fatty acids), or linseed oil (LIN, high n-3, low n-6 fatty acids). After weaning, the rats were maintained in the same light environment and fed the same diets for 9 weeks, at which time some were killed and their retinas processed for morphometric analysis. Animals raised in bright cyclic light had shorter ROS lengths and thinner outer nuclear layers (ONL) than rats raised in dim cyclic light. The LIN animals had a thinner ONL than animals of the SAF or COC groups. Rats from each diet and light rearing groups were exposed to constant illumination of 2000 lx for 24 hr, after which they and non-exposed controls were placed in 1 lx cyclic light for 10 days and analysed for changes in ONL thickness. In the 250 lx (bright; B) groups, there was no effect of acute light stress on ONL thickness, although both control and stressed LIN animals had a thinner ONL than the corresponding COC and SAF groups. However, in the rats raised in 1 lx cyclic light, acute stress resulted in significant retinal damage (i.e. decrease in ONL thickness) in the three diet groups combined. The superior region was damaged the most and the severity was dependent on diet, as evidenced by the LIN group having a greater reduction in ONL thickness than the SAF group after light stress. From these results we conclude that rats on diets high in n-3 fatty acids are more susceptible to photoreceptor cell loss than animals fed n-6 or no polyunsaturated fatty acids when raised in dim cyclic light. These results show that both diet and light history play a role in the susceptibility of the retina to acute and chronic effects of light and suggest a role for lipid peroxidation in retinal light damage.

Effect of dietary fat on the response of the rat retina to chronic and acute light stress

We designed an experiment to study the role of light history and polyunsaturated fatty acids (PUFA) on the susceptibility of the albino rat retina to light damage. Albino rats were born to dams that had been kept in either 1 lx or 250 lx cyclic light for 0-4 days prior to delivery and fed one of three diets containing either 10% (by weight) hydrogenated coconut oil (COC, no n-3 nor n-6 fatty acids), safflower oil (SAF, high n-6, < 0.1% n-3 fatty acids), or linseed oil (LIN, high n-3, low n-6 fatty acids). After weaning, the rats were maintained in the same light environment and fed the same diets for 9 weeks, at which time some were killed and their retinas processed for morphometric analysis. Animals raised in bright cyclic light had shorter ROS lengths and thinner outer nuclear layers (ONL) than rats raised in dim cyclic light. The LIN animals had a thinner ONL than animals of the SAF or COC groups. Rats from each diet and light rearing groups were exposed to constant illumination of 2000 lx for 24 hr, after which they and non-exposed controls were placed in 1 lx cyclic light for 10 days and analysed for changes in ONL thickness. In the 250 lx (bright; B) groups, there was no effect of acute light stress on ONL thickness, although both control and stressed LIN animals had a thinner ONL than the corresponding COC and SAF groups. However, in the rats raised in 1 lx cyclic light, acute stress resulted in significant retinal damage (i.e. decrease in ONL thickness) in the three diet groups combined. The superior region was damaged the most and the severity was dependent on diet, as evidenced by the LIN group having a greater reduction in ONL thickness than the SAF group after light stress. From these results we conclude that rats on diets high in n-3 fatty acids are more susceptible to photoreceptor cell loss than animals fed n-6 or no polyunsaturated fatty acids when raised in dim cyclic light. These results show that both diet and light history play a role in the susceptibility of the retina to acute and chronic effects of light and suggest a role for lipid peroxidation in retinal light damage.

Effect of dietary fat and environmental lighting on the phospholipid molecular species of rat photoreceptor membranes

We have previously shown that retinas of albino rats adapt to bright cyclic light (500-800 lx) by lowering the levels of docosahexaenoic acid (22:6n-3) in their rod outer segment (ROS) phospholipids. In the present study, we addressed the role of dietary fat in this process. Pregnant rats were kept in 1 lx or 250 lx cyclic illuminance (12L:12D) and fed diets containing 10% (by weight) of either hydrogenated coconut oil (COC, no n-3 or n-6 fatty acids), linseed oil (LIN, n-3 and n-6 fatty acids), or safflower oil (SAF, only n-6 fatty acids), starting 4 days before delivery. Pups were weaned at 3 weeks of age and continued on the same diet and light regime. At 12 weeks of age, 3 or 4 animals in each diet-light group were killed and the remaining animals were stressed continuously with 2000 lx light for 24 hr and then kept in 1 lx cyclic light for 10 days. Fatty acids and phospholipid molecular species (PLMS) of ROS membranes were determined. For prestressed groups, those animals fed the LIN diet had high levels of 22:6n-3 and PLMS containing 22:6n-3, with little 22:5n-6. Compared to the LIN group, the COC and SAF groups had lower levels of 22:6n-3- and 22:6n-3)-containing PLMS and higher levels of 22:5n-6 and molecular species containing 22:5n-6, such as 22:5n-6/22:6n-3, 16:0/22:5n-6 and 18:0/22:5n-6. Within each dietary group, animals raised in 250 lx cyclic illuminance had lower levels of 22:6n-3 and 22:5n-6 compared to those raised at 1 lx. This light effect was greater for 22:6n-3 in the LIN group than for 22:5n-6 in the SAF group. After the acute light stress, those animals raised in 1 lx showed dramatic reduction in PLMS containing 22:6n-3 and 22:5n-6, especially polyenoic species such as 22:6n-3/22:6n-3 in the LIN group and 22:5n-6/22:6n-3 in the COC and SAF groups. In contrast, animals raised in 250 lx showed much smaller changes.(ABSTRACT TRUNCATED AT 250 WORDS)

Purified dietary n − 3 polyunsaturated fatty acids alter diacylglycerol mass and molecular species composition in concanavalin A-stimulated murine splenocytes

A low-dose, short-term dietary supplementation with highly purified ( n − 3) fatty acid ethyl esters was studied in mice to determine the effect on splenic cell membrane diacylglycerol mass and composition. Mice were fed diets containing either 3% safflower oil (SAP) ethyl esters, 2% SAP plus 1% eicosapentaenoic acid ethyl ester (EPA), or 2% SAP plus 1% docosahexaenoic acid ethyl ester (DHA). Following a 10-day feeding period, pathogen-free mice were sacrificed and splenic cells isolated and stimulated with concanavalin A (Con A) at 10 μg/ml. After 0 min (basal), 5 min, and 180 min, 1,2-diacyl, 1- O-alkyl-2-acyl, and 1- O-alkenyl-2-acyl- sn-glycerol subclasses were isolated and quantitated by HPLC. Diacylglycerol (DAG) was found to be the major diradylglycerol (DG) component in murine splenocytes. DHA-fed mice had significantly ( P < 0.05) higher levels of DAG at all stimulation time points relative to EPA and SAP animals. Significant effects ( P < 0.05) of diet, time, and a diet × time interaction ( P < 0.05) were noted for various DAG molecular species. In general, a significantly higher ( n − 3) polyunsaturated fatty acid (PUFA) content in the EPA and DHA groups, and a significantly higher ( n − 6) PUFA content in the SAF group was noted. 18:0–22: 5( n − 3), 18:1–22:5( n − 3) and 16:1–20:5( n − 3) species were present only in EPA and DHA-DAG, confirming the incorporation of ( n − 3) fatty acids into splenocyte DAG. The data indicate that the molecular species composition of murine splenocyte DAG is significantly modulated by low-dose, short-term EPA and DHA feeding. In addition, substitution of SAP with DHA results in an increase in DAG mass. These alterations could potentially influence signal transduction pathways regulating lymphocyte function.

Effects of purified dietary n-3 ethyl esters on murine T lymphocyte function.

To precisely determine the biologic role of fish oil-derived constituents (n-3 polyunsaturated fatty acids), it is imperative that information on highly purified n-3 polyunsaturated fatty acids be evolved. Therefore, we studied the effects of a low dose, short term dietary supplementation with highly purified (n-3) ethyl esters with regard to murine T lymphocyte function. A 10-day dietary supplementation with low dose, highly purified (n-3) fatty acid ethyl esters was examined for effects on murine splenic lymphocyte function and membrane composition. Mice were fed diets containing either 3% safflower oil (SAF) ethyl esters, 2% SAF plus 1% eicosapentaenoic acid ethyl esters (EPA) (99% pure), or 2% SAF plus 1% docosahexaenoic acid ethyl esters (DHA) (97% pure). Fatty acid analysis of the lymphocyte membranes showed that membrane compositions of the EPA- and DHA-fed mice were subsequently enriched with these (n-3) fatty acids. Con A-induced lymphoproliferative assays (Con A, 5 and 10 micrograms/ml) revealed that splenic lymphocytes from the EPA group had significantly higher mitogenic responses relative to lymphocytes from the DHA or SAF groups (p < 0.05). In contrast, DHA splenocytes had the highest level of 3H-labeled diradylglycerol as a percentage of total lipid. Macrophage-lymphocyte co-cultures demonstrated that the dietary effect on proliferation in response to Con A was influenced by lymphocyte source, but apparently not by macrophage source. In addition, cells from Mycobacterium bovis vaccine-vaccinated mice were placed in culture with purified protein derivative (PPD) (10, 20, and 40 micrograms/ml), as well as Con A (5 and 10 micrograms/ml) to allow comparison between mitogenic and antigenic stimulation. No statistically significant differences (p > 0.05) existed between the diet groups upon PPD stimulation. However, lymphocytes from the DHA group exhibited significantly higher proliferative responses to Con A than cells from the EPA and SAF groups (p < 0.05). M. bovis vaccine-immunized EPA and DHA fed mice also exhibited significantly reduced delayed-type hypersensitive reactivity to footpad testing with PPD in comparison to that demonstrated by SAF-fed mice (p < 0.05). EPA-fed mice demonstrated the most decreased response. Overall, this study demonstrates for the first time that: 1) low dose, short term dietary supplementation with highly purified EPA or DHA can modulate select functional and transmembrane signaling responses of murine splenic lymphocytes; and 2) that these dietary agents have differing effects on mitogen vs Ag receptors.

Antimalarial effects of purified and α-tocopherol—fortified n-3 polyunsaturated fatty acids

A vitamin E-deficient diet containing fish oil is known to afford a protection against malaria in mice. In the present study we examined whether the dietary supplementation with α-tocopherol—fortified n-3 polyunsaturated fatty acid (PUFA) ethyl esters (eicosapentaenoic acid (EPA) ethyl ester and docosahexaenoic acid (DHA) ethyl ester) had a protective effect against malaria. Four groups of mice were each given one of the following diets: (1). powered standard chow (REF group); (2). 90% (wt) lipid-free diet with 8% lard and 2% safflower oil (SAF group); (3). 90% lipid-free diet with 8% lard and 2% EPA ethyl ester (EPA group); and (4). 90% lipid-free diet with 8% lard and 2% DHA ethyl ester (DHA group). Safflower oil, EPA, and DHA were fortified with 0.2% α-tocopherol before mixing dietary components. After 6 weeks on these diets, mice were inoculated with Plasmodium yoelii, and the same diets were continued until the end of the experiment. The survival rates of the four groups 46 days after the inoculation were 1 2 , 0 12 , 5 12 , and 4 10 in the REF, SAF, EPA, and DHA groups, respectively. There was a significant difference in the survival rates ( P < 0.025) among the groups. It may be possible to conduct a clinical trial with malarial patients using EPA or DHA ethyl ester fortified with α-tocopherol.

Effects of dietary n-3 and n-6 fatty acids on liver and erythrocyte lipids in streptozotocin-induced diabetic rats.

Streptozotocin-induced diabetic and control rats were placed in one of two dietary groups and fed diets with a P/S ratio of 2.2-2.3 for 4 weeks. The n-3/n-6 ratios in the dietary groups were 0.01 (SAF group) and 2.92 (PER group). A decrease in the 20:4n-6 level, and an increase in the 18:2n-6 level were observed in the erythrocyte lipids of diabetic rats of both dietary groups, as compared with the levels in control rats. The cholesterol/lipid-P ratio in erythrocyte lipids was significantly higher in diabetic rats than in control rats in both dietary groups, while the ratio in livers was significantly lower in diabetic rats. In liver phospholipids, the differences between the polyunsaturated fatty acid contents of control and diabetic rats in the SAF group, were almost identical to those in erythrocyte lipids. However, in the PER group, a small increase in the 20:4n-6 level, besides an obvious increase in the 18:2n-6 level, was observed in diabetic rats, and n-3 fatty acid levels, especially that of 20:5n-3, were lower significantly in diabetic rats than in control rats. Plasma triglyceride and cholesterol levels in diabetic rats were higher than those in control rats in both dietary groups. The two dietary groups showed significant different triglyceride levels, but similar cholesterol levels. It is suggested that the physiological effect of 18:3n-3 is impaired in diabetes in the same manner as that of 18:2n-6 is.

Serum lipoprotein alterations of rabbits fed high fat soy protein-dextrose diets

Male New Zealand white rabbits were pair-fed high fat, soy protein-dextrose diets containing either hydrogenated coconut oil (HCO) or safflower oil (SAF) for 100 days. A third group was fed a low fat, soy protein dextrose-corn oil diet (SD) previously shown to be normocholesterolemic in this model. All animals gained similar amounts of weight during the feeding period. The HCO group was significantly hyperlipidemic with elevations of total cholesterol (TC), esterified cholesterol (EC), and phospholipid (PL) fractions. Significant increases of all serum lipoproteins were observed with the HCO diet. The greatest lipoprotein mass increase was in the intermediate density (IDL) fraction. Elevations of EC, PL, and protein contents of all lipoprotein classes were also observed with the HCO diet. Free cholesterol (FC) and triglyceride (TG) were increased to a lesser extent resulting in a net EC enrichment relative to TG among core components. Fatty acid analyses of lipoprotein lipid fractions (TG, EC, PL) reflected the dietary fat type fed except in the IDL fraction of the SAF group. In this instance, significant amounts of oleic acid relative to linoleic acid were observed. This alteration may be the result of the previously reported positional specificity of lipoprotein lipase (LPL) especially when very low density lipoprotein substrates are enriched in linoleate as in the SAF diet fed case. That this change did not occur in the LDL fraction suggests that additional mechanisms other than LPL catalyzed hydrolysis also contribute to LDL composition in the steady state. Such mechanisms may include EC transfer protein mediated exchange, membrane receptor activities, and direct tissue synthesis. The extent to which IDL also participates in such mechanisms also remains to be elucidated.

Energetic Efficiency and Mitochondrial Function in Rats Fed trans Fatty Acids

Nutritional experiments with growing rats were conducted to study the effect of dietary t18:1 and t,t18:2 in mixtures with safflower oil (77.1% linoleate) on oxidative phosphorylation of isolated liver mitochondria and on energetic efficiency as measured in energy balance experiments. Partially hydrogenated soybean oil (PHSO) with 45% t18:1 and an ethyl ester concentrate of trans fatty acids (TRANS) containing 52% t,t18:2 were used. Six groups of male rats were fed diets with 10% (wt/wt) fat supplements: 1, safflower oil (SAF); 2, 8% PHSO + 2% SAF; 3, 0.5% TRANS + 9.5% SAF; 4, 1% TRANS + 9% SAF; 5, 2% TRANS + 8% SAF; and 6, 5% TRANS + 5% SAF. These fat supplements contained 77.1, 17.1, 73.3, 69.4, 61.7 and 38% linoleate for groups 1–6, respectively. The basal metabolic rate was not affected by dietary treatments, neither were the metabolizable energy values. As compared to the SAF group, rats receiving the 8% PHSO + 2% SAF showed no different effect on energy utilization or mitochondrial respiratory function. TRANS was found to reduce the efficiency of metabolizable energy utilization at the 5% level (group 6), while mitochondrial ATP synthesis was significantly depressed in both the 2% and the 5% TRANS groups. A parallelism was observed between t,t18:2 incorporation in liver mitochondria, reduced mitochondrial oxidative function and depressed energetic efficiency. The experiments indicated that t,t18:2 exerted a significantly negative effect on energy utilization at 1.0 and 2.5% levels in the diet even when fed with relatively high concentrations of linoleate.

Periodontal bone loss in ovalbumin sensitized germfree rats fed antigen-free diet with ovalbumin.

The cellular and humoral responses in ovalbumin (OVA) presensitized germfree rats fed OVA (SAF), in an otherwise antigen‐free diet, were compared to sham‐sensitized animals that were also fed OVA (SSAF). Sensitized animals demonstrated relatively more lymphocytes in their gingival tissues. An initial predominance of T lymphocytes gave way to a predominance of B‐lymphocytes. Splenic lymphocytes from presensitized animals showed significant blastogenesis at the time antigen feeding was initiated. Sensitized animals showed elevated blastogenesis throughout the feeding period whereas the sham‐sensitized animals showed some elevated responses only after 38 days of antigen feeding. The plasma IgG response to OVA was markedly elevated in the sensitized animals, in contrast to a low or nonexistent IgG antibody response in the sham‐sensitized rats. On the other hand, IgA anti‐OVA responses in intestinal perfusates were elevated in the SAF group for the first 14 to 21 days of feeding. Early salivary IgA responses (0 to 21 days) were essentially the same between the groups, but later (38 to 84 days) both IgA and IgG responses in saliva were elevated in the SAF group. Sensitized animals demonstrated significantly elevated periodontal bone loss after 84 or 128 days of OVA feeding. The potential effects of “mixed” hypersensitivity on periodontal disease in the rat are discussed.